full-jdk7u71-b01.patch

1 files changed, 12176 insertions, 0 deletions

diff --git a/hotspot/.hg/patches/full-jdk7u71-b01.patch b/hotspot/.hg/patches/full-jdk7u71-b01.patch
new file mode 100644
index 00000000..26bd5aa3
--- /dev/null
+++ b/hotspot/.hg/patches/full-jdk7u71-b01.patch
@@ -0,0 +1,12176 @@
+diff --git a/make/bsd/makefiles/gcc.make b/make/bsd/makefiles/gcc.make
+index 3de1dea..8bf7f94 100644
+--- a/make/bsd/makefiles/gcc.make
++++ b/make/bsd/makefiles/gcc.make
+@@ -117,7 +117,10 @@ CFLAGS += $(VM_PICFLAG)
+ CFLAGS += -fno-rtti
+ CFLAGS += -fno-exceptions
+ CFLAGS += -pthread
+-CFLAGS += -fcheck-new
++## well, strictly speaking we should check for clang not Darwin
++ifneq ($(OS_VENDOR), Darwin)
++  CFLAGS += -fcheck-new
++endif
+ # version 4 and above support fvisibility=hidden (matches jni_x86.h file)
+ # except 4.1.2 gives pointless warnings that can't be disabled (afaik)
+ ifneq "$(shell expr \( $(CC_VER_MAJOR) \> 4 \) \| \( \( $(CC_VER_MAJOR) = 4 \) \& \( $(CC_VER_MINOR) \>= 3 \) \))" "0"
+diff --git a/src/cpu/x86/vm/templateTable_x86_32.cpp b/src/cpu/x86/vm/templateTable_x86_32.cpp
+index fc19edc..d2cddd3 100644
+--- a/src/cpu/x86/vm/templateTable_x86_32.cpp
++++ b/src/cpu/x86/vm/templateTable_x86_32.cpp
+@@ -2109,6 +2109,22 @@ void TemplateTable::resolve_cache_and_index(int byte_no,
+   // resolve first time through
+   address entry;
+   switch (bytecode()) {
++    case Bytecodes::_fast_agetfield : // fall through
++    case Bytecodes::_fast_bgetfield : // fall through
++    case Bytecodes::_fast_cgetfield : // fall through
++    case Bytecodes::_fast_dgetfield : // fall through
++    case Bytecodes::_fast_fgetfield : // fall through
++    case Bytecodes::_fast_igetfield : // fall through
++    case Bytecodes::_fast_lgetfield : // fall through
++    case Bytecodes::_fast_sgetfield : // fall through
++    case Bytecodes::_fast_aputfield : // fall through
++    case Bytecodes::_fast_bputfield : // fall through
++    case Bytecodes::_fast_cputfield : // fall through
++    case Bytecodes::_fast_dputfield : // fall through
++    case Bytecodes::_fast_fputfield : // fall through
++    case Bytecodes::_fast_iputfield : // fall through
++    case Bytecodes::_fast_lputfield : // fall through
++    case Bytecodes::_fast_sputfield : // fall through
+     case Bytecodes::_getstatic      : // fall through
+     case Bytecodes::_putstatic      : // fall through
+     case Bytecodes::_getfield       : // fall through
+@@ -2211,6 +2227,7 @@ void TemplateTable::load_invoke_cp_cache_entry(int byte_no,
+ // Correct values of the cache and index registers are preserved.
+ void TemplateTable::jvmti_post_field_access(Register cache,
+                                             Register index,
++                                            int byte_no,
+                                             bool is_static,
+                                             bool has_tos) {
+   if (JvmtiExport::can_post_field_access()) {
+@@ -2237,7 +2254,11 @@ void TemplateTable::jvmti_post_field_access(Register cache,
+     // cache: cache entry pointer
+     __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_field_access),
+                rax, cache);
+-    __ get_cache_and_index_at_bcp(cache, index, 1);
++    
++    // DCEVM: Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
++
+     __ bind(L1);
+   }
+ }
+@@ -2258,7 +2279,7 @@ void TemplateTable::getfield_or_static(int byte_no, bool is_static) {
+   const Register flags = rax;
+ 
+   resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
+-  jvmti_post_field_access(cache, index, is_static, false);
++  jvmti_post_field_access(cache, index, byte_no, is_static, false);
+   load_field_cp_cache_entry(obj, cache, index, off, flags, is_static);
+ 
+   if (!is_static) pop_and_check_object(obj);
+@@ -2393,7 +2414,7 @@ void TemplateTable::getstatic(int byte_no) {
+ 
+ // The registers cache and index expected to be set before call.
+ // The function may destroy various registers, just not the cache and index registers.
+-void TemplateTable::jvmti_post_field_mod(Register cache, Register index, bool is_static) {
++void TemplateTable::jvmti_post_field_mod(Register cache, Register index, int byte_no, bool is_static) {
+ 
+   ByteSize cp_base_offset = constantPoolCacheOopDesc::base_offset();
+ 
+@@ -2451,7 +2472,11 @@ void TemplateTable::jvmti_post_field_mod(Register cache, Register index, bool is
+     // rcx: jvalue object on the stack
+     __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_field_modification),
+                rbx, rax, rcx);
+-    __ get_cache_and_index_at_bcp(cache, index, 1);
++
++    // (tw) Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
++
+     __ bind(L1);
+   }
+ }
+@@ -2467,7 +2492,7 @@ void TemplateTable::putfield_or_static(int byte_no, bool is_static) {
+   const Register flags = rax;
+ 
+   resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
+-  jvmti_post_field_mod(cache, index, is_static);
++  jvmti_post_field_mod(cache, index, byte_no, is_static);
+   load_field_cp_cache_entry(obj, cache, index, off, flags, is_static);
+ 
+   // Doug Lea believes this is not needed with current Sparcs (TSO) and Intel (PSO).
+@@ -2818,6 +2843,11 @@ void TemplateTable::fast_accessfield(TosState state) {
+     // rcx: cache entry pointer
+     __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_field_access), rax, rcx);
+     __ pop_ptr(rax);   // restore object pointer
++
++    // DCEVM: Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(1, noreg, rax, rcx, sizeof(u2));
++
+     __ bind(L1);
+   }
+ 
+@@ -3008,6 +3038,26 @@ void TemplateTable::invokevirtual_helper(Register index,
+ 
+   __ bind(notFinal);
+ 
++  // DCEVM: Check if we are calling an old method (and have to go slow path)
++  Label notOld;
++  __ movl(rax, flags);
++  __ andl(rax, (1 << ConstantPoolCacheEntry::is_old_method_shift));
++  __ jcc(Assembler::zero, notOld);
++
++  // Need a null check here!
++  __ null_check(recv);
++
++  // Call out to VM to do look up based on correct vTable version (has to iterate back over the class history of the receiver class)
++  // DCEVM: TODO: Check if we can improve performance by inlining.
++  // DCEVM: TODO: Check if this additional branch affects normal execution time.
++  __ call_VM(method, CAST_FROM_FN_PTR(address, InterpreterRuntime::find_correct_method), recv, index);
++  
++  // profile this call
++  __ profile_final_call(rax);
++  __ jump_from_interpreted(method, rdx);
++
++  __ bind(notOld);
++
+   // get receiver klass
+   __ null_check(recv, oopDesc::klass_offset_in_bytes());
+   __ load_klass(rax, recv);
+@@ -3093,6 +3143,31 @@ void TemplateTable::invokeinterface(int byte_no) {
+   invokevirtual_helper(rbx, rcx, rdx);
+   __ bind(notMethod);
+ 
++  // DCEVM: Check if we are calling an old method (and have to go slow path)
++  //__ movl(rax, rdx);
++  Label notOld;
++  __ andl(rdx, (1 << ConstantPoolCacheEntry::is_old_method_shift));
++  __ jcc(Assembler::zero, notOld);
++
++  // Get receiver klass into rdx - also a null check
++  __ movptr(rdx, Address(rcx, oopDesc::klass_offset_in_bytes()));
++  __ verify_oop(rdx);
++
++  // Call out to VM to do look up based on correct vTable version (has to iterate back over the class history of the receiver class)
++  // DCEVM: TODO: Check if we can improve performance by inlining.
++  // DCEVM: TODO: Check if this additional branch affects normal execution time.
++  // DCEVM: TODO: Check the exact semantic (with respect to destoying registers) of call_VM
++  __ call_VM(rbx, CAST_FROM_FN_PTR(address, InterpreterRuntime::find_correct_interface_method), rcx, rax, rbx);
++
++  // DCEVM: TODO: Check if resolved method could be null.
++
++  // profile this call
++  __ profile_virtual_call(rdx, rsi, rdi);
++
++  __ jump_from_interpreted(rbx, rdx);
++
++  __ bind(notOld);
++
+   // Get receiver klass into rdx - also a null check
+   __ restore_locals();  // restore rdi
+   __ null_check(rcx, oopDesc::klass_offset_in_bytes());
+diff --git a/src/cpu/x86/vm/templateTable_x86_64.cpp b/src/cpu/x86/vm/templateTable_x86_64.cpp
+index 932ee97..67bb710 100644
+--- a/src/cpu/x86/vm/templateTable_x86_64.cpp
++++ b/src/cpu/x86/vm/templateTable_x86_64.cpp
+@@ -2151,6 +2151,22 @@ void TemplateTable::resolve_cache_and_index(int byte_no,
+   // resolve first time through
+   address entry;
+   switch (bytecode()) {
++  case Bytecodes::_fast_agetfield : // fall through
++  case Bytecodes::_fast_bgetfield : // fall through
++  case Bytecodes::_fast_cgetfield : // fall through
++  case Bytecodes::_fast_dgetfield : // fall through
++  case Bytecodes::_fast_fgetfield : // fall through
++  case Bytecodes::_fast_igetfield : // fall through
++  case Bytecodes::_fast_lgetfield : // fall through
++  case Bytecodes::_fast_sgetfield : // fall through
++  case Bytecodes::_fast_aputfield : // fall through
++  case Bytecodes::_fast_bputfield : // fall through
++  case Bytecodes::_fast_cputfield : // fall through
++  case Bytecodes::_fast_dputfield : // fall through
++  case Bytecodes::_fast_fputfield : // fall through
++  case Bytecodes::_fast_iputfield : // fall through
++  case Bytecodes::_fast_lputfield : // fall through
++  case Bytecodes::_fast_sputfield : // fall through
+   case Bytecodes::_getstatic:
+   case Bytecodes::_putstatic:
+   case Bytecodes::_getfield:
+@@ -2267,7 +2283,7 @@ void TemplateTable::load_invoke_cp_cache_entry(int byte_no,
+ // The registers cache and index expected to be set before call.
+ // Correct values of the cache and index registers are preserved.
+ void TemplateTable::jvmti_post_field_access(Register cache, Register index,
+-                                            bool is_static, bool has_tos) {
++                                            int byte_no, bool is_static, bool has_tos) {
+   // do the JVMTI work here to avoid disturbing the register state below
+   // We use c_rarg registers here because we want to use the register used in
+   // the call to the VM
+@@ -2298,7 +2314,11 @@ void TemplateTable::jvmti_post_field_access(Register cache, Register index,
+     __ call_VM(noreg, CAST_FROM_FN_PTR(address,
+                                        InterpreterRuntime::post_field_access),
+                c_rarg1, c_rarg2, c_rarg3);
+-    __ get_cache_and_index_at_bcp(cache, index, 1);
++    
++    // DCEVM: Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
++
+     __ bind(L1);
+   }
+ }
+@@ -2320,7 +2340,7 @@ void TemplateTable::getfield_or_static(int byte_no, bool is_static) {
+   const Register bc = c_rarg3; // uses same reg as obj, so don't mix them
+ 
+   resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
+-  jvmti_post_field_access(cache, index, is_static, false);
++  jvmti_post_field_access(cache, index, byte_no, is_static, false);
+   load_field_cp_cache_entry(obj, cache, index, off, flags, is_static);
+ 
+   if (!is_static) {
+@@ -2455,7 +2475,7 @@ void TemplateTable::getstatic(int byte_no) {
+ 
+ // The registers cache and index expected to be set before call.
+ // The function may destroy various registers, just not the cache and index registers.
+-void TemplateTable::jvmti_post_field_mod(Register cache, Register index, bool is_static) {
++void TemplateTable::jvmti_post_field_mod(Register cache, Register index, int byte_no, bool is_static) {
+   transition(vtos, vtos);
+ 
+   ByteSize cp_base_offset = constantPoolCacheOopDesc::base_offset();
+@@ -2507,7 +2527,11 @@ void TemplateTable::jvmti_post_field_mod(Register cache, Register index, bool is
+                CAST_FROM_FN_PTR(address,
+                                 InterpreterRuntime::post_field_modification),
+                c_rarg1, c_rarg2, c_rarg3);
+-    __ get_cache_and_index_at_bcp(cache, index, 1);
++
++    // DCEVM: Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
++
+     __ bind(L1);
+   }
+ }
+@@ -2523,7 +2547,7 @@ void TemplateTable::putfield_or_static(int byte_no, bool is_static) {
+   const Register bc    = c_rarg3;
+ 
+   resolve_cache_and_index(byte_no, noreg, cache, index, sizeof(u2));
+-  jvmti_post_field_mod(cache, index, is_static);
++  jvmti_post_field_mod(cache, index, byte_no, is_static);
+   load_field_cp_cache_entry(obj, cache, index, off, flags, is_static);
+ 
+   // [jk] not needed currently
+@@ -2837,6 +2861,11 @@ void TemplateTable::fast_accessfield(TosState state) {
+                                 InterpreterRuntime::post_field_access),
+                c_rarg1, c_rarg2);
+     __ pop_ptr(rax); // restore object pointer
++
++    // DCEVM: Redefinition might have occured => reresolve the cp entry.
++    __ restore_bcp();
++    resolve_cache_and_index(1, noreg, rax, rcx, sizeof(u2));
++
+     __ bind(L1);
+   }
+ 
+@@ -3073,6 +3102,26 @@ void TemplateTable::invokevirtual_helper(Register index,
+ 
+   __ bind(notFinal);
+ 
++  // DCEVM: Check if we are calling an old method (and have to go slow path)
++  Label notOld;
++  __ movl(rax, flags);
++  __ andl(rax, (1 << ConstantPoolCacheEntry::is_old_method_shift));
++  __ jcc(Assembler::zero, notOld);
++
++  // Need a null check here!
++  __ null_check(recv);
++
++  // Call out to VM to do look up based on correct vTable version (has to iterate back over the class history of the receiver class)
++  // DCEVM: TODO: Check if we can improve performance by inlining.
++  // DCEVM: TODO: Check if this additional branch affects normal execution time.
++  __ call_VM(method, CAST_FROM_FN_PTR(address, InterpreterRuntime::find_correct_method), recv, index);
++
++  // profile this call
++  __ profile_final_call(rax);
++  __ jump_from_interpreted(method, rdx);
++
++  __ bind(notOld);
++
+   // get receiver klass
+   __ null_check(recv, oopDesc::klass_offset_in_bytes());
+   __ load_klass(rax, recv);
+@@ -3156,6 +3205,35 @@ void TemplateTable::invokeinterface(int byte_no) {
+   invokevirtual_helper(rbx, rcx, rdx);
+   __ bind(notMethod);
+ 
++  // DCEVM: Check if we are calling an old method (and have to go slow path)
++  Label notOld;
++  __ andl(rdx, (1 << ConstantPoolCacheEntry::is_old_method_shift));
++  __ jcc(Assembler::zero, notOld);
++
++  // Call out to VM to do look up based on correct vTable version (has to iterate back over the class history of the receiver class)
++  // DCEVM: TODO: Check if we can improve performance by inlining.
++  // DCEVM: TODO: Check if this additional branch affects normal execution time.
++  // DCEVM: TODO: Check the exact semantic (with respect to destoying registers) of call_VM
++  // DCEVM: FIXME: What exactly should we store here?
++  __ push(rcx); // destroyed by Linux arguments passing conventions
++  __ movptr(r14, rcx);
++  __ call_VM(rbx, CAST_FROM_FN_PTR(address, InterpreterRuntime::find_correct_interface_method), r14, rax, rbx);
++  __ pop(rcx);
++
++  // Get receiver klass into rdx - also a null check
++  __ restore_locals(); // restore r14
++  __ load_klass(rdx, rcx);
++  __ verify_oop(rdx);
++
++  // DCEVM: TODO: Check if resolved method could be null.
++
++  // profile this call
++  __ profile_virtual_call(rdx, r13, r14);
++
++  __ jump_from_interpreted(rbx, rdx);
++
++  __ bind(notOld);
++
+   // Get receiver klass into rdx - also a null check
+   __ restore_locals();  // restore r14
+   __ null_check(rcx, oopDesc::klass_offset_in_bytes());
+diff --git a/src/share/vm/c1/c1_Compilation.hpp b/src/share/vm/c1/c1_Compilation.hpp
+index 9a8ca61..196ab25 100644
+--- a/src/share/vm/c1/c1_Compilation.hpp
++++ b/src/share/vm/c1/c1_Compilation.hpp
+@@ -242,8 +242,8 @@ class Compilation: public StackObj {
+ #define BAILOUT(msg)               { bailout(msg); return;              }
+ #define BAILOUT_(msg, res)         { bailout(msg); return res;          }
+ 
+-#define CHECK_BAILOUT()            { if (bailed_out()) return;          }
+-#define CHECK_BAILOUT_(res)        { if (bailed_out()) return res;      }
++#define CHECK_BAILOUT()            { if (((CompilerThread *)Thread::current())->should_bailout()) bailout("Aborted externally"); if (bailed_out()) return;          }
++#define CHECK_BAILOUT_(res)        { if (((CompilerThread *)Thread::current())->should_bailout()) bailout("Aborted externally"); if (bailed_out()) return res;      }
+ 
+ 
+ class InstructionMark: public StackObj {
+diff --git a/src/share/vm/ci/ciEnv.cpp b/src/share/vm/ci/ciEnv.cpp
+index e20db5d..57f37db 100644
+--- a/src/share/vm/ci/ciEnv.cpp
++++ b/src/share/vm/ci/ciEnv.cpp
+@@ -1172,3 +1172,11 @@ void ciEnv::record_out_of_memory_failure() {
+   // If memory is low, we stop compiling methods.
+   record_method_not_compilable("out of memory");
+ }
++
++// DCEVM: Called after class redefinition to clean up possibly invalidated state.
++void ciEnv::cleanup_after_redefinition() {
++
++  if (_factory != NULL) {
++    _factory->cleanup_after_redefinition();
++  }
++}
+diff --git a/src/share/vm/ci/ciEnv.hpp b/src/share/vm/ci/ciEnv.hpp
+index 103e532..abe2e37 100644
+--- a/src/share/vm/ci/ciEnv.hpp
++++ b/src/share/vm/ci/ciEnv.hpp
+@@ -417,6 +417,8 @@ public:
+   void record_failure(const char* reason);
+   void record_method_not_compilable(const char* reason, bool all_tiers = true);
+   void record_out_of_memory_failure();
++
++  void cleanup_after_redefinition();
+ };
+ 
+ #endif // SHARE_VM_CI_CIENV_HPP
+diff --git a/src/share/vm/ci/ciObjectFactory.cpp b/src/share/vm/ci/ciObjectFactory.cpp
+index e0ab96b..36efef4 100644
+--- a/src/share/vm/ci/ciObjectFactory.cpp
++++ b/src/share/vm/ci/ciObjectFactory.cpp
+@@ -296,6 +296,11 @@ ciObject* ciObjectFactory::get(oop key) {
+       // into the table.  We need to recompute our index.
+       index = find(keyHandle(), _ci_objects);
+     }
++
++    if (is_found_at(index, keyHandle(), _ci_objects)) {
++      // DCEVM: Check if this is an error? Can occur when redefining classes.
++      return _ci_objects->at(index);
++    }
+     assert(!is_found_at(index, keyHandle(), _ci_objects), "no double insert");
+     insert(index, new_object, _ci_objects);
+     return new_object;
+@@ -764,3 +769,50 @@ void ciObjectFactory::print() {
+              _unloaded_instances->length(),
+              _unloaded_klasses->length());
+ }
++
++// DCEVM: Resoring the ciObject arrays after class redefinition
++void ciObjectFactory::sort_ci_objects(GrowableArray<ciObject*>* objects) {
++
++  // Resort the _ci_objects array. The order of two class pointers can be changed during class redefinition.
++  oop last = NULL;
++  for (int j = 0; j< objects->length(); j++) {
++    oop o = objects->at(j)->get_oop();
++    if (last >= o) {
++      int cur_last_index = j - 1;
++      oop cur_last = last;
++      while (cur_last >= o) {
++
++        // Swap the two objects to guarantee ordering
++        ciObject *tmp = objects->at(cur_last_index);
++        objects->at_put(cur_last_index, objects->at(cur_last_index + 1));
++        objects->at_put(cur_last_index + 1, tmp);
++
++        // Decrement index to move one step to the left
++        cur_last_index--;
++        if (cur_last_index < 0) {
++          break;
++        }
++        cur_last = objects->at(cur_last_index)->get_oop();
++      }
++    } else {
++      assert(last < o, "out of order");
++      last = o;  
++    }
++  }
++
++#ifdef ASSERT
++  if (CIObjectFactoryVerify) {
++    oop last = NULL;
++    for (int j = 0; j< objects->length(); j++) {
++      oop o = objects->at(j)->get_oop();
++      assert(last < o, "out of order");
++      last = o;
++    }
++  }
++#endif // ASSERT
++}
++
++// DCEVM: Called after class redefinition to clean up possibly invalidated state.
++void ciObjectFactory::cleanup_after_redefinition() {
++  sort_ci_objects(_ci_objects);
++}
+diff --git a/src/share/vm/ci/ciObjectFactory.hpp b/src/share/vm/ci/ciObjectFactory.hpp
+index 26cc2c3..855a4ac 100644
+--- a/src/share/vm/ci/ciObjectFactory.hpp
++++ b/src/share/vm/ci/ciObjectFactory.hpp
+@@ -38,6 +38,7 @@
+ class ciObjectFactory : public ResourceObj {
+   friend class VMStructs;
+   friend class ciEnv;
++  friend class CompileBroker;
+ 
+ private:
+   static volatile bool _initialized;
+@@ -137,6 +138,11 @@ public:
+ 
+   void print_contents();
+   void print();
++
++private:
++
++  static void sort_ci_objects(GrowableArray<ciObject*>* objects);
++  void cleanup_after_redefinition();
+ };
+ 
+ #endif // SHARE_VM_CI_CIOBJECTFACTORY_HPP
+diff --git a/src/share/vm/classfile/classFileParser.cpp b/src/share/vm/classfile/classFileParser.cpp
+index 8c5e970..fc624bf 100644
+--- a/src/share/vm/classfile/classFileParser.cpp
++++ b/src/share/vm/classfile/classFileParser.cpp
+@@ -795,6 +795,7 @@ objArrayHandle ClassFileParser::parse_interfaces(constantPoolHandle cp,
+                                                  Handle class_loader,
+                                                  Handle protection_domain,
+                                                  Symbol* class_name,
++                                                 KlassHandle old_klass,
+                                                  TRAPS) {
+   ClassFileStream* cfs = stream();
+   assert(length > 0, "only called for length>0");
+@@ -813,6 +814,9 @@ objArrayHandle ClassFileParser::parse_interfaces(constantPoolHandle cp,
+       interface_index, CHECK_(nullHandle));
+     if (cp->tag_at(interface_index).is_klass()) {
+       interf = KlassHandle(THREAD, cp->resolved_klass_at(interface_index));
++      if (!old_klass.is_null() && !interf->is_newest_version()) {
++        interf = KlassHandle(THREAD, interf->newest_version());
++      }
+     } else {
+       Symbol*  unresolved_klass  = cp->klass_name_at(interface_index);
+ 
+@@ -825,6 +829,9 @@ objArrayHandle ClassFileParser::parse_interfaces(constantPoolHandle cp,
+       klassOop k = SystemDictionary::resolve_super_or_fail(class_name,
+                     unresolved_klass, class_loader, protection_domain,
+                     false, CHECK_(nullHandle));
++      if (!old_klass.is_null()) {
++        k = k->klass_part()->newest_version();
++      }
+       interf = KlassHandle(THREAD, k);
+     }
+ 
+@@ -1923,6 +1930,8 @@ methodHandle ClassFileParser::parse_method(Handle class_loader, constantPoolHand
+   int runtime_invisible_parameter_annotations_length = 0;
+   u1* annotation_default = NULL;
+   int annotation_default_length = 0;
++  u2 code_section_table_length;
++  typeArrayHandle code_section_table;
+ 
+   // Parse code and exceptions attribute
+   u2 method_attributes_count = cfs->get_u2_fast();
+@@ -2092,6 +2101,24 @@ methodHandle ClassFileParser::parse_method(Handle class_loader, constantPoolHand
+             parse_stackmap_table(code_attribute_length, CHECK_(nullHandle));
+           stackmap_data = typeArrayHandle(THREAD, sm);
+           parsed_stackmap_attribute = true;
++        } else if (UseMethodForwardPoints && cp->symbol_at(code_attribute_name_index) == vmSymbols::tag_code_sections()) {
++          int length = code_attribute_length;
++          int value_count = length / sizeof(u2);
++          int line_count = length / 3;
++          if (TraceRedefineClasses >= 3) {
++            tty->print_cr("Found code section attribute when loading class with %d entries", value_count, line_count);
++          }
++          code_section_table_length = value_count;
++          code_section_table = oopFactory::new_permanent_shortArray(value_count, CHECK_NULL);
++          code_section_table->set_length(value_count);
++
++          for (int i = 0; i < value_count; ++i) {
++            u2 value = cfs->get_u2(CHECK_(nullHandle));
++            code_section_table->short_at_put(i, value);
++            if (TraceRedefineClasses >= 4) {
++              tty->print_cr("Code section table at %d: %d", i, value);
++            }
++          }
+         } else {
+           // Skip unknown attributes
+           cfs->skip_u1(code_attribute_length, CHECK_(nullHandle));
+@@ -2216,6 +2243,18 @@ methodHandle ClassFileParser::parse_method(Handle class_loader, constantPoolHand
+   }
+ #endif
+ 
++  // DCEVM: TODO: Get a different solution for the problem of method forward
++  // points and variable sized interpreter frames.
++  if (UseMethodForwardPoints) {
++    if (max_stack > MethodForwardPointsMaxStack) {
++      fatal(err_msg("Method has too large stack (%d), increase the value of MethodForwardPointsMaxStack (%d)", max_stack, MethodForwardPointsMaxStack));
++    }
++    if (max_locals > MethodForwardPointsMaxLocals) {
++      fatal(err_msg("Method has too many locals (%d), increase the value of MethodForwardPointsMaxLocals (%d)", max_stack, MethodForwardPointsMaxStack));
++    }
++    max_stack = MethodForwardPointsMaxStack;
++    max_locals = MethodForwardPointsMaxLocals;
++  }
+   // Fill in code attribute information
+   m->set_max_stack(max_stack);
+   m->set_max_locals(max_locals);
+@@ -2229,6 +2268,8 @@ methodHandle ClassFileParser::parse_method(Handle class_loader, constantPoolHand
+    */
+   m->constMethod()->set_stackmap_data(stackmap_data());
+ 
++  m->constMethod()->set_code_section_table(code_section_table());
++
+   // Copy byte codes
+   m->set_code(code_start);
+ 
+@@ -2825,6 +2866,15 @@ void ClassFileParser::parse_classfile_attributes(Handle class_loader,
+           "Invalid Deprecated classfile attribute length %u in class file %s",
+           attribute_length, CHECK);
+       }
++    } else if (tag == vmSymbols::tag_field_redefinition_policy()) {
++      // DCEVM: Check for deleted field attribute
++	  _field_redefinition_policy = cfs->get_u1_fast();
++	} else if (tag == vmSymbols::tag_static_field_redefinition_policy()) {
++	  // DCEVM: Check for deleted static field attribute
++	  _static_field_redefinition_policy = cfs->get_u1_fast();
++    } else if (tag == vmSymbols::tag_method_redefinition_policy()) {
++      // DCEVM: Check for deleted method attribute
++      _method_redefinition_policy = cfs->get_u1_fast();
+     } else if (_major_version >= JAVA_1_5_VERSION) {
+       if (tag == vmSymbols::tag_signature()) {
+         if (attribute_length != 2) {
+@@ -2929,6 +2979,17 @@ void ClassFileParser::apply_parsed_class_attributes(instanceKlassHandle k) {
+   }
+   k->set_inner_classes(_inner_classes());
+   k->set_class_annotations(_annotations());
++
++
++  if (_field_redefinition_policy != 0xff) {
++    k->set_field_redefinition_policy(_field_redefinition_policy);
++  }
++  if (_static_field_redefinition_policy != 0xff) {
++    k->set_static_field_redefinition_policy(_static_field_redefinition_policy);
++  }
++  if (_method_redefinition_policy != 0xff) {
++    k->set_method_redefinition_policy(_method_redefinition_policy);
++  }
+ }
+ 
+ typeArrayHandle ClassFileParser::assemble_annotations(u1* runtime_visible_annotations,
+@@ -2952,9 +3013,126 @@ typeArrayHandle ClassFileParser::assemble_annotations(u1* runtime_visible_annota
+ }
+ 
+ 
++// DCEVM: Finds the super symbols by reading the bytes of the class and returns
++// them in a growable array.
++void ClassFileParser::findSuperSymbols(Symbol* name,
++                          Handle class_loader,
++                          Handle protection_domain,
++                          KlassHandle old_klass,
++                          GrowableArray<Symbol*> &handles,
++                          TRAPS) {
++  
++  _cp_patches = NULL;
++  // So that JVMTI can cache class file in the state before retransformable agents
++  // have modified it
++  unsigned char *cached_class_file_bytes = NULL;
++
++  ClassFileStream* cfs = stream();
++
++  _has_finalizer = _has_empty_finalizer = _has_vanilla_constructor = false;
++
++  instanceKlassHandle nullHandle;
++
++  // Save the class file name for easier error message printing.
++  _class_name = name != NULL ? name : vmSymbols::unknown_class_name();
++
++  cfs->guarantee_more(8, CHECK);  // magic, major, minor
++  // Magic value
++  u4 magic = cfs->get_u4_fast();
++  if (magic != JAVA_CLASSFILE_MAGIC) {
++    // Invalid class file!
++    return;
++  }
++
++  // Version numbers
++  u2 minor_version = cfs->get_u2_fast();
++  u2 major_version = cfs->get_u2_fast();
++
++  // Check version numbers - we check this even with verifier off
++  if (!is_supported_version(major_version, minor_version)) {
++    
++    // Unsupported version!
++    return;
++  }
++
++  _major_version = major_version;
++  _minor_version = minor_version;
++
++
++  // Check if verification needs to be relaxed for this class file
++  // Do not restrict it to jdk1.0 or jdk1.1 to maintain backward compatibility (4982376)
++  _relax_verify = Verifier::relax_verify_for(class_loader());
++  _need_verify = false;
++
++  // Constant pool
++  constantPoolHandle cp = parse_constant_pool(class_loader(), CHECK);
++  int cp_size = cp->length();
++
++  cfs->guarantee_more(8, CHECK);  // flags, this_class, super_class, infs_len
++
++  // Access flags
++  AccessFlags access_flags;
++  jint flags = cfs->get_u2_fast() & JVM_RECOGNIZED_CLASS_MODIFIERS;
++
++  if ((flags & JVM_ACC_INTERFACE) && _major_version < JAVA_6_VERSION) {
++    // Set abstract bit for old class files for backward compatibility
++    flags |= JVM_ACC_ABSTRACT;
++  }
++  access_flags.set_flags(flags);
++
++  // This class and superclass
++  instanceKlassHandle super_klass;
++  u2 this_class_index = cfs->get_u2_fast();
++  check_property(
++    valid_cp_range(this_class_index, cp_size) &&
++    cp->tag_at(this_class_index).is_unresolved_klass(),
++    "Invalid this class index %u in constant pool in class file %s",
++    this_class_index, CHECK);
++
++  Symbol* class_name = cp->unresolved_klass_at(this_class_index);
++  assert(class_name != NULL, "class_name can't be null");
++
++  // Update _class_name which could be null previously to be class_name
++  _class_name = class_name;
++
++  // DCEVM: DO NOT release all handles when parsing is done
++  {// HandleMark hm(THREAD);
++
++    // Checks if name in class file matches requested name
++    if (name != NULL && class_name != name) {
++      return;
++    }
++
++    u2 super_class_index = cfs->get_u2_fast();
++
++    if (super_class_index != 0) {
++      Symbol* super_class = cp->klass_name_at(super_class_index);
++      handles.append(super_class);
++    } else {
++      // DCEVM: This redefinition must be for the Object class.
++    }
++
++    // Interfaces
++    u2 itfs_len = cfs->get_u2_fast();
++    objArrayHandle local_interfaces;
++    if (itfs_len == 0) {
++      local_interfaces = objArrayHandle(THREAD, Universe::the_empty_system_obj_array());
++    } else {
++      local_interfaces = parse_interfaces(cp, itfs_len, class_loader, protection_domain, _class_name, old_klass, CHECK);
++    }
++
++    for (int i=0; i<local_interfaces->length(); i++) {
++      oop o = local_interfaces->obj_at(i);
++      Symbol* interface_handle = ((klassOop)o)->klass_part()->name();
++      handles.append(interface_handle);
++    }
++  }
++}
++
+ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+                                                     Handle class_loader,
+                                                     Handle protection_domain,
++                                                    KlassHandle old_klass,
+                                                     KlassHandle host_klass,
+                                                     GrowableArray<Handle>* cp_patches,
+                                                     TempNewSymbol& parsed_name,
+@@ -3005,10 +3183,13 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+     unsigned char* ptr = cfs->buffer();
+     unsigned char* end_ptr = cfs->buffer() + cfs->length();
+ 
++    bool pretend_new_universe = Thread::current()->pretend_new_universe();
++    Thread::current()->set_pretend_new_universe(false);
+     JvmtiExport::post_class_file_load_hook(name, class_loader, protection_domain,
+                                            &ptr, &end_ptr,
+                                            &cached_class_file_bytes,
+                                            &cached_class_file_length);
++    Thread::current()->set_pretend_new_universe(pretend_new_universe);
+ 
+     if (ptr != cfs->buffer()) {
+       // JVMTI agent has modified class file data.
+@@ -3164,7 +3345,11 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+       // However, make sure it is not an array type.
+       bool is_array = false;
+       if (cp->tag_at(super_class_index).is_klass()) {
+-        super_klass = instanceKlassHandle(THREAD, cp->resolved_klass_at(super_class_index));
++        klassOop resolved_klass = cp->resolved_klass_at(super_class_index);
++        if (!old_klass.is_null()) {
++          resolved_klass = resolved_klass->klass_part()->newest_version();
++        }
++        super_klass = instanceKlassHandle(THREAD, resolved_klass);
+         if (_need_verify)
+           is_array = super_klass->oop_is_array();
+       } else if (_need_verify) {
+@@ -3182,7 +3367,7 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+     if (itfs_len == 0) {
+       local_interfaces = objArrayHandle(THREAD, Universe::the_empty_system_obj_array());
+     } else {
+-      local_interfaces = parse_interfaces(cp, itfs_len, class_loader, protection_domain, _class_name, CHECK_(nullHandle));
++      local_interfaces = parse_interfaces(cp, itfs_len, class_loader, protection_domain, _class_name, old_klass, CHECK_(nullHandle));
+     }
+ 
+     u2 java_fields_count = 0;
+@@ -3237,7 +3422,9 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+                                                            protection_domain,
+                                                            true,
+                                                            CHECK_(nullHandle));
+-
++      if (!old_klass.is_null()) {
++        k = k->klass_part()->newest_version();
++      }
+       KlassHandle kh (THREAD, k);
+       super_klass = instanceKlassHandle(THREAD, kh());
+     }
+@@ -3626,6 +3813,19 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+       rt = REF_NONE;
+     } else {
+       rt = super_klass->reference_type();
++
++      // DCEVM: With class redefinition, it can also happen that special classes are loaded.
++      if (name == vmSymbols::java_lang_ref_Reference()) {
++        rt = REF_OTHER;
++      } else if (name == vmSymbols::java_lang_ref_SoftReference()) {
++        rt = REF_SOFT;
++      } else if (name == vmSymbols::java_lang_ref_WeakReference()) {
++        rt = REF_WEAK;
++      } else if (name == vmSymbols::java_lang_ref_FinalReference()) {
++        rt = REF_FINAL;
++      } else if (name == vmSymbols::java_lang_ref_PhantomReference()) {
++        rt = REF_PHANTOM;
++      }
+     }
+ 
+     // We can now create the basic klassOop for this klass
+@@ -3726,7 +3926,7 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+     fill_oop_maps(this_klass, nonstatic_oop_map_count, nonstatic_oop_offsets, nonstatic_oop_counts);
+ 
+     // Fill in has_finalizer, has_vanilla_constructor, and layout_helper
+-    set_precomputed_flags(this_klass);
++    set_precomputed_flags(this_klass, old_klass);
+ 
+     // reinitialize modifiers, using the InnerClasses attribute
+     int computed_modifiers = this_klass->compute_modifier_flags(CHECK_(nullHandle));
+@@ -3749,6 +3949,10 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+     // Allocate mirror and initialize static fields
+     java_lang_Class::create_mirror(this_klass, CHECK_(nullHandle));
+ 
++    if (rt == REF_OTHER) {
++      instanceRefKlass::update_nonstatic_oop_maps(ik);
++    }
++
+     ClassLoadingService::notify_class_loaded(instanceKlass::cast(this_klass()),
+                                              false /* not shared class */);
+ 
+@@ -3891,7 +4095,7 @@ void ClassFileParser::fill_oop_maps(instanceKlassHandle k,
+ }
+ 
+ 
+-void ClassFileParser::set_precomputed_flags(instanceKlassHandle k) {
++void ClassFileParser::set_precomputed_flags(instanceKlassHandle k, KlassHandle old_klass) {
+   klassOop super = k->super();
+ 
+   // Check if this klass has an empty finalize method (i.e. one with return bytecode only),
+@@ -3899,7 +4103,9 @@ void ClassFileParser::set_precomputed_flags(instanceKlassHandle k) {
+   if (!_has_empty_finalizer) {
+     if (_has_finalizer ||
+         (super != NULL && super->klass_part()->has_finalizer())) {
+-      k->set_has_finalizer();
++      if (old_klass.is_null() || old_klass->has_finalizer()) {
++        k->set_has_finalizer();
++      }
+     }
+   }
+ 
+@@ -3915,7 +4121,7 @@ void ClassFileParser::set_precomputed_flags(instanceKlassHandle k) {
+ 
+   // Check if this klass supports the java.lang.Cloneable interface
+   if (SystemDictionary::Cloneable_klass_loaded()) {
+-    if (k->is_subtype_of(SystemDictionary::Cloneable_klass())) {
++    if (k->is_subtype_of(SystemDictionary::Cloneable_klass()) || k->is_subtype_of(SystemDictionary::Cloneable_klass()->klass_part()->newest_version())) {
+       k->set_is_cloneable();
+     }
+   }
+diff --git a/src/share/vm/classfile/classFileParser.hpp b/src/share/vm/classfile/classFileParser.hpp
+index a95a784..ac217fc 100644
+--- a/src/share/vm/classfile/classFileParser.hpp
++++ b/src/share/vm/classfile/classFileParser.hpp
+@@ -64,6 +64,9 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
+   int        _sde_length;
+   typeArrayHandle _inner_classes;
+   typeArrayHandle _annotations;
++  u1         _field_redefinition_policy;
++  u1         _static_field_redefinition_policy;
++  u1         _method_redefinition_policy;
+ 
+   void set_class_synthetic_flag(bool x)           { _synthetic_flag = x; }
+   void set_class_sourcefile(Symbol* x)            { _sourcefile = x; }
+@@ -151,6 +154,7 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
+                                   Handle class_loader,
+                                   Handle protection_domain,
+                                   Symbol* class_name,
++                                  KlassHandle old_klass,
+                                   TRAPS);
+ 
+   // Field parsing
+@@ -239,7 +243,7 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
+                      unsigned int nonstatic_oop_map_count,
+                      int* nonstatic_oop_offsets,
+                      unsigned int* nonstatic_oop_counts);
+-  void set_precomputed_flags(instanceKlassHandle k);
++  void set_precomputed_flags(instanceKlassHandle k, KlassHandle old_klass);
+   objArrayHandle compute_transitive_interfaces(instanceKlassHandle super,
+                                                objArrayHandle local_ifs, TRAPS);
+ 
+@@ -345,7 +349,12 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
+ 
+  public:
+   // Constructor
+-  ClassFileParser(ClassFileStream* st) { set_stream(st); }
++  ClassFileParser(ClassFileStream* st) {
++      set_stream(st);
++      _field_redefinition_policy = 0xff;
++      _static_field_redefinition_policy = 0xff;
++      _method_redefinition_policy = 0xff;
++  }
+ 
+   // Parse .class file and return new klassOop. The klassOop is not hooked up
+   // to the system dictionary or any other structures, so a .class file can
+@@ -357,21 +366,33 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
+   instanceKlassHandle parseClassFile(Symbol* name,
+                                      Handle class_loader,
+                                      Handle protection_domain,
++                                     KlassHandle old_klass,
+                                      TempNewSymbol& parsed_name,
+                                      bool verify,
+                                      TRAPS) {
+     KlassHandle no_host_klass;
+-    return parseClassFile(name, class_loader, protection_domain, no_host_klass, NULL, parsed_name, verify, THREAD);
++    return parseClassFile(name, class_loader, protection_domain, old_klass, no_host_klass, NULL, parsed_name, verify, THREAD);
+   }
+   instanceKlassHandle parseClassFile(Symbol* name,
+                                      Handle class_loader,
+                                      Handle protection_domain,
++                                     KlassHandle old_klass,
+                                      KlassHandle host_klass,
+                                      GrowableArray<Handle>* cp_patches,
+                                      TempNewSymbol& parsed_name,
+                                      bool verify,
+                                      TRAPS);
+ 
++  static void initialize_static_field(fieldDescriptor* fd, TRAPS);
++
++  // DCEVM: Creates symbol handles for the super class and the interfaces
++  void findSuperSymbols(Symbol* name,
++                        Handle class_loader,
++                        Handle protection_domain,
++                        KlassHandle old_klass,
++                        GrowableArray<Symbol*> &handles,
++                        TRAPS);
++
+   // Verifier checks
+   static void check_super_class_access(instanceKlassHandle this_klass, TRAPS);
+   static void check_super_interface_access(instanceKlassHandle this_klass, TRAPS);
+diff --git a/src/share/vm/classfile/classLoader.cpp b/src/share/vm/classfile/classLoader.cpp
+index a2e61a4..450e19f 100644
+--- a/src/share/vm/classfile/classLoader.cpp
++++ b/src/share/vm/classfile/classLoader.cpp
+@@ -915,6 +915,7 @@ instanceKlassHandle ClassLoader::load_classfile(Symbol* h_name, TRAPS) {
+     instanceKlassHandle result = parser.parseClassFile(h_name,
+                                                        class_loader,
+                                                        protection_domain,
++                                                       KlassHandle(),
+                                                        parsed_name,
+                                                        false,
+                                                        CHECK_(h));
+diff --git a/src/share/vm/classfile/dictionary.cpp b/src/share/vm/classfile/dictionary.cpp
+index 78e76cc..ee21f3a 100644
+--- a/src/share/vm/classfile/dictionary.cpp
++++ b/src/share/vm/classfile/dictionary.cpp
+@@ -326,6 +326,21 @@ void Dictionary::classes_do(void f(klassOop)) {
+   }
+ }
+ 
++
++// DCEVM: Just the classes from defining class loaders
++void Dictionary::classes_do(ObjectClosure *closure) {
++  for (int index = 0; index < table_size(); index++) {
++    for (DictionaryEntry* probe = bucket(index);
++      probe != NULL;
++      probe = probe->next()) {
++        klassOop k = probe->klass();
++        if (probe->loader() == instanceKlass::cast(k)->class_loader()) {
++          closure->do_object(k);
++        }
++    }
++  }
++}
++
+ // Added for initialize_itable_for_klass to handle exceptions
+ //   Just the classes from defining class loaders
+ void Dictionary::classes_do(void f(klassOop, TRAPS), TRAPS) {
+@@ -433,6 +448,33 @@ void Dictionary::add_klass(Symbol* class_name, Handle class_loader,
+   add_entry(index, entry);
+ }
+ 
++// DCEVM: Updates the klass entry to point to the new klassOop. Necessary only for class redefinition.
++bool Dictionary::update_klass(int index, unsigned int hash, Symbol* name, Handle loader, KlassHandle k, KlassHandle old_class) {
++
++  // There are several entries for the same class in the dictionary: One extra entry for each parent classloader of the classloader of the class.
++  bool found = false;
++  for (int index = 0; index < table_size(); index++) {
++    for (DictionaryEntry* entry = bucket(index); entry != NULL; entry = entry->next()) {
++      if (entry->klass() == old_class()) {
++        entry->set_literal(k());
++        found = true;
++      }
++    }
++  }
++
++  return found;
++}
++
++// DCEVM: Undo previous updates to the system dictionary
++void Dictionary::rollback_redefinition() {
++  for (int index = 0; index < table_size(); index++) {
++    for (DictionaryEntry* entry = bucket(index); entry != NULL; entry = entry->next()) {
++      if (entry->klass()->klass_part()->is_redefining()) {
++        entry->set_literal(entry->klass()->klass_part()->old_version());
++      }
++    }
++  }
++}
+ 
+ // This routine does not lock the system dictionary.
+ //
+@@ -459,12 +501,22 @@ DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
+   return NULL;
+ }
+ 
++// DCEVM: return old version if we are not in the new universe?
++klassOop Dictionary::intercept_for_version(klassOop k) {
++  if (k == NULL) return k;
++
++  if (k->klass_part()->is_redefining() && !Thread::current()->pretend_new_universe()) {
++    return k->klass_part()->old_version();
++  }
++
++  return k;
++}
+ 
+ klassOop Dictionary::find(int index, unsigned int hash, Symbol* name,
+                           Handle loader, Handle protection_domain, TRAPS) {
+   DictionaryEntry* entry = get_entry(index, hash, name, loader);
+   if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
+-    return entry->klass();
++    return intercept_for_version(entry->klass());
+   } else {
+     return NULL;
+   }
+@@ -477,7 +529,7 @@ klassOop Dictionary::find_class(int index, unsigned int hash,
+   assert (index == index_for(name, loader), "incorrect index?");
+ 
+   DictionaryEntry* entry = get_entry(index, hash, name, loader);
+-  return (entry != NULL) ? entry->klass() : (klassOop)NULL;
++  return intercept_for_version((entry != NULL) ? entry->klass() : (klassOop)NULL);
+ }
+ 
+ 
+@@ -489,7 +541,7 @@ klassOop Dictionary::find_shared_class(int index, unsigned int hash,
+   assert (index == index_for(name, Handle()), "incorrect index?");
+ 
+   DictionaryEntry* entry = get_entry(index, hash, name, Handle());
+-  return (entry != NULL) ? entry->klass() : (klassOop)NULL;
++  return intercept_for_version((entry != NULL) ? entry->klass() : (klassOop)NULL);
+ }
+ 
+ 
+diff --git a/src/share/vm/classfile/dictionary.hpp b/src/share/vm/classfile/dictionary.hpp
+index bd33760..186d0eb 100644
+--- a/src/share/vm/classfile/dictionary.hpp
++++ b/src/share/vm/classfile/dictionary.hpp
+@@ -73,6 +73,10 @@ public:
+ 
+   void add_klass(Symbol* class_name, Handle class_loader,KlassHandle obj);
+ 
++  bool update_klass(int index, unsigned int hash, Symbol* name, Handle loader, KlassHandle k, KlassHandle old_class);
++
++  void rollback_redefinition();
++
+   klassOop find_class(int index, unsigned int hash,
+                       Symbol* name, Handle loader);
+ 
+@@ -89,6 +93,7 @@ public:
+   void classes_do(void f(klassOop, TRAPS), TRAPS);
+   void classes_do(void f(klassOop, oop));
+   void classes_do(void f(klassOop, oop, TRAPS), TRAPS);
++  void classes_do(ObjectClosure *closure);
+ 
+   void methods_do(void f(methodOop));
+ 
+@@ -105,6 +110,7 @@ public:
+   bool do_unloading(BoolObjectClosure* is_alive);
+ 
+   // Protection domains
++  static klassOop intercept_for_version(klassOop k);
+   klassOop find(int index, unsigned int hash, Symbol* name,
+                 Handle loader, Handle protection_domain, TRAPS);
+   bool is_valid_protection_domain(int index, unsigned int hash,
+diff --git a/src/share/vm/classfile/javaClasses.cpp b/src/share/vm/classfile/javaClasses.cpp
+index 7dd5f1b..9c7d8eb 100644
+--- a/src/share/vm/classfile/javaClasses.cpp
++++ b/src/share/vm/classfile/javaClasses.cpp
+@@ -1798,7 +1798,7 @@ Handle java_lang_reflect_Method::create(TRAPS) {
+   klassOop klass = SystemDictionary::reflect_Method_klass();
+   // This class is eagerly initialized during VM initialization, since we keep a refence
+   // to one of the methods
+-  assert(instanceKlass::cast(klass)->is_initialized(), "must be initialized");
++  assert(instanceKlass::cast(klass)->is_initialized() || klass->klass_part()->old_version() != NULL, "must be initialized");
+   return instanceKlass::cast(klass)->allocate_instance_handle(CHECK_NH);
+ }
+ 
+diff --git a/src/share/vm/classfile/javaClasses.hpp b/src/share/vm/classfile/javaClasses.hpp
+index 36d1cec..a6de98e 100644
+--- a/src/share/vm/classfile/javaClasses.hpp
++++ b/src/share/vm/classfile/javaClasses.hpp
+@@ -213,7 +213,6 @@ class java_lang_String : AllStatic {
+ 
+ class java_lang_Class : AllStatic {
+   friend class VMStructs;
+-
+  private:
+   // The fake offsets are added by the class loader when java.lang.Class is loaded
+ 
+diff --git a/src/share/vm/classfile/loaderConstraints.cpp b/src/share/vm/classfile/loaderConstraints.cpp
+index 8650cd9..965cce2 100644
+--- a/src/share/vm/classfile/loaderConstraints.cpp
++++ b/src/share/vm/classfile/loaderConstraints.cpp
+@@ -449,7 +449,7 @@ void LoaderConstraintTable::verify(Dictionary* dictionary,
+         if (k != NULL) {
+           // We found the class in the system dictionary, so we should
+           // make sure that the klassOop matches what we already have.
+-          guarantee(k == probe->klass(), "klass should be in dictionary");
++          guarantee(k == probe->klass()->klass_part()->newest_version(), "klass should be in dictionary");
+         } else {
+           // If we don't find the class in the system dictionary, it
+           // has to be in the placeholders table.
+diff --git a/src/share/vm/classfile/loaderConstraints.hpp b/src/share/vm/classfile/loaderConstraints.hpp
+index d01b2c4..1ad80f7 100644
+--- a/src/share/vm/classfile/loaderConstraints.hpp
++++ b/src/share/vm/classfile/loaderConstraints.hpp
+@@ -106,7 +106,7 @@ public:
+ 
+   klassOop klass() { return literal(); }
+   klassOop* klass_addr() { return literal_addr(); }
+-  void set_klass(klassOop k) { set_literal(k); }
++  void set_klass(klassOop k) { set_literal(k); assert(k == NULL || !k->klass_part()->is_redefining(), "just checking"); }
+ 
+   LoaderConstraintEntry* next() {
+     return (LoaderConstraintEntry*)HashtableEntry<klassOop, mtClass>::next();
+diff --git a/src/share/vm/classfile/systemDictionary.cpp b/src/share/vm/classfile/systemDictionary.cpp
+index 4899d32..365aeda 100644
+--- a/src/share/vm/classfile/systemDictionary.cpp
++++ b/src/share/vm/classfile/systemDictionary.cpp
+@@ -157,6 +157,7 @@ klassOop SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_load
+     // can return a null klass
+     klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
+   }
++  assert(klass == NULL || klass->klass_part()->is_newest_version() || klass->klass_part()->newest_version()->klass_part()->is_redefining(), "must be");
+   return klass;
+ }
+ 
+@@ -199,7 +200,8 @@ klassOop SystemDictionary::resolve_or_fail(Symbol* class_name,
+ // Forwards to resolve_instance_class_or_null
+ 
+ klassOop SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
+-  assert(!THREAD->is_Compiler_thread(),
++  // DCEVM: Check if this relaxing of the condition is correct? Test case hs203t004 failing otherwise.
++  assert(!THREAD->is_Compiler_thread() || JvmtiThreadState::state_for(JavaThread::current())->get_class_being_redefined() != NULL,
+          err_msg("can not load classes with compiler thread: class=%s, classloader=%s",
+                  class_name->as_C_string(),
+                  class_loader.is_null() ? "null" : class_loader->klass()->klass_part()->name()->as_C_string()));
+@@ -961,6 +963,7 @@ klassOop SystemDictionary::parse_stream(Symbol* class_name,
+   instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
+                                                              class_loader,
+                                                              protection_domain,
++                                                             KlassHandle(),
+                                                              host_klass,
+                                                              cp_patches,
+                                                              parsed_name,
+@@ -1022,7 +1025,14 @@ klassOop SystemDictionary::resolve_from_stream(Symbol* class_name,
+                                                Handle protection_domain,
+                                                ClassFileStream* st,
+                                                bool verify,
++                                               KlassHandle old_class,
+                                                TRAPS) {
++  bool redefine_classes_locked = false;
++  if (!Thread::current()->redefine_classes_mutex()->owned_by_self()) {
++    Thread::current()->redefine_classes_mutex()->lock();
++    redefine_classes_locked = true;
++  }
++  
+   // Classloaders that support parallelism, e.g. bootstrap classloader,
+   // or all classloaders with UnsyncloadClass do not acquire lock here
+   bool DoObjectLock = true;
+@@ -1050,9 +1060,14 @@ klassOop SystemDictionary::resolve_from_stream(Symbol* class_name,
+   instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
+                                                              class_loader,
+                                                              protection_domain,
++                                                             old_class,
+                                                              parsed_name,
+                                                              verify,
+                                                              THREAD);
++  if (!old_class.is_null() && !k.is_null()) {
++    k->set_redefining(true);
++    k->set_old_version(old_class());
++  }
+ 
+   const char* pkg = "java/";
+   if (!HAS_PENDING_EXCEPTION &&
+@@ -1087,13 +1102,18 @@ klassOop SystemDictionary::resolve_from_stream(Symbol* class_name,
+     // Add class just loaded
+     // If a class loader supports parallel classloading handle parallel define requests
+     // find_or_define_instance_class may return a different instanceKlass
+-    if (is_parallelCapable(class_loader)) {
++    // (tw) TODO: for class redefinition the parallel version does not work, check if this is a problem?
++    if (is_parallelCapable(class_loader) && old_class.is_null()) {
+       k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
+     } else {
+-      define_instance_class(k, THREAD);
++      define_instance_class(k, old_class, THREAD);
+     }
+   }
+ 
++  if (redefine_classes_locked) {
++    Thread::current()->redefine_classes_mutex()->unlock();
++  }
++
+   // If parsing the class file or define_instance_class failed, we
+   // need to remove the placeholder added on our behalf. But we
+   // must make sure parsed_name is valid first (it won't be if we had
+@@ -1122,7 +1142,7 @@ klassOop SystemDictionary::resolve_from_stream(Symbol* class_name,
+       MutexLocker mu(SystemDictionary_lock, THREAD);
+ 
+       klassOop check = find_class(parsed_name, class_loader);
+-      assert(check == k(), "should be present in the dictionary");
++      assert((check == k() && !k->is_redefining()) || (k->is_redefining() && check == k->old_version()), "should be present in the dictionary");
+ 
+       klassOop check2 = find_class(h_name, h_loader);
+       assert(check == check2, "name inconsistancy in SystemDictionary");
+@@ -1349,7 +1369,11 @@ instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Ha
+   }
+ }
+ 
+-void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
++void SystemDictionary::rollback_redefinition() {
++  dictionary()->rollback_redefinition();
++}
++
++void SystemDictionary::define_instance_class(instanceKlassHandle k, KlassHandle old_class, TRAPS) {
+ 
+   Handle class_loader_h(THREAD, k->class_loader());
+ 
+@@ -1376,13 +1400,23 @@ void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
+   Symbol*  name_h = k->name();
+   unsigned int d_hash = dictionary()->compute_hash(name_h, class_loader_h);
+   int d_index = dictionary()->hash_to_index(d_hash);
+-  check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
++
++  // DCEVM: Update version of the klassOop in the system dictionary
++  // TODO: Check for thread safety!
++  if (!old_class.is_null()) {
++    bool ok = dictionary()->update_klass(d_index, d_hash, name_h, class_loader_h, k, old_class);
++    assert (ok, "must have found old class and updated!");
++  }
++  check_constraints(d_index, d_hash, k, class_loader_h, old_class.is_null(), CHECK);
++
++  if(!old_class.is_null() && TraceRedefineClasses >= 3){ tty->print_cr("Class has been updated!"); }
+ 
+   // Register class just loaded with class loader (placed in Vector)
+   // Note we do this before updating the dictionary, as this can
+   // fail with an OutOfMemoryError (if it does, we will *not* put this
+   // class in the dictionary and will not update the class hierarchy).
+-  if (k->class_loader() != NULL) {
++  // (tw) Only register if not redefining a class.
++  if (k->class_loader() != NULL && old_class.is_null()) {
+     methodHandle m(THREAD, Universe::loader_addClass_method());
+     JavaValue result(T_VOID);
+     JavaCallArguments args(class_loader_h);
+@@ -1408,8 +1442,9 @@ void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
+   }
+   k->eager_initialize(THREAD);
+ 
++  // (tw) Only notify jvmti if not redefining a class.
+   // notify jvmti
+-  if (JvmtiExport::should_post_class_load()) {
++  if (JvmtiExport::should_post_class_load() && old_class.is_null()) {
+       assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
+       JvmtiExport::post_class_load((JavaThread *) THREAD, k());
+ 
+@@ -1482,7 +1517,7 @@ instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* clas
+     }
+   }
+ 
+-  define_instance_class(k, THREAD);
++  define_instance_class(k, KlassHandle(), THREAD);
+ 
+   Handle linkage_exception = Handle(); // null handle
+ 
+@@ -1613,6 +1648,14 @@ void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
+   Universe::flush_dependents_on(k);
+ }
+ 
++// (tw) Remove from hierarchy - Undo add_to_hierarchy.
++void SystemDictionary::remove_from_hierarchy(instanceKlassHandle k) {
++  assert(k.not_null(), "just checking");
++
++  k->remove_from_sibling_list();
++
++  // TODO: Remove from interfaces.
++}
+ 
+ // ----------------------------------------------------------------------------
+ // GC support
+@@ -1702,6 +1745,24 @@ void SystemDictionary::oops_do(OopClosure* f) {
+ }
+ 
+ 
++// (tw) Iterate over all pre-loaded classes in the dictionary.
++void SystemDictionary::preloaded_classes_do(OopClosure *f) {
++  for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
++    f->do_oop((oop*) &_well_known_klasses[k]);
++  }
++
++  {
++    for (int i = 0; i < T_VOID+1; i++) {
++      if (_box_klasses[i] != NULL) {
++        assert(i >= T_BOOLEAN, "checking");
++        f->do_oop((oop*) &_box_klasses[i]);
++      }
++    }
++  }
++
++  // TODO: Check if we need to call FilterFieldsMap
++}
++
+ void SystemDictionary::preloaded_oops_do(OopClosure* f) {
+   for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
+     f->do_oop((oop*) &_well_known_klasses[k]);
+@@ -1734,6 +1795,11 @@ void SystemDictionary::classes_do(void f(klassOop)) {
+   dictionary()->classes_do(f);
+ }
+ 
++// (tw) Iterate over all classes in the dictionary.
++void SystemDictionary::classes_do(ObjectClosure *closure) {
++  dictionary()->classes_do(closure);
++}
++
+ // Added for initialize_itable_for_klass
+ //   Just the classes from defining class loaders
+ // Don't iterate over placeholders
+@@ -1870,7 +1936,9 @@ void SystemDictionary::initialize_preloaded_classes(TRAPS) {
+ 
+   // Preload ref klasses and set reference types
+   instanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
+-  instanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
++
++  // (tw) This is now done in parseClassFile in order to support class redefinition
++  // instanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
+ 
+   initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
+   instanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
+@@ -1956,7 +2024,11 @@ void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
+       // also holds array classes
+ 
+       assert(check->klass_part()->oop_is_instance(), "noninstance in systemdictionary");
+-      if ((defining == true) || (k() != check)) {
++      if ((defining == true) && ((k() != check) && k->old_version() != check)) {
++        ResourceMark rm(Thread::current());
++        tty->print_cr("(%d / %d) (%s/%s)", k->revision_number(), check->klass_part()->revision_number(), k->name()->as_C_string(), check->klass_part()->name()->as_C_string());
++        k()->print();
++        check->print();
+         linkage_error = "loader (instance of  %s): attempted  duplicate class "
+           "definition for name: \"%s\"";
+       } else {
+diff --git a/src/share/vm/classfile/systemDictionary.hpp b/src/share/vm/classfile/systemDictionary.hpp
+index 324d53d..0c600ae 100644
+--- a/src/share/vm/classfile/systemDictionary.hpp
++++ b/src/share/vm/classfile/systemDictionary.hpp
+@@ -269,7 +269,7 @@ public:
+   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
+   static klassOop resolve_from_stream(Symbol* class_name, Handle class_loader,
+                                       Handle protection_domain,
+-                                      ClassFileStream* st, bool verify, TRAPS);
++                                      ClassFileStream* st, bool verify, KlassHandle old_class, TRAPS);
+ 
+   // Lookup an already loaded class. If not found NULL is returned.
+   static klassOop find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
+@@ -310,6 +310,8 @@ public:
+   // Iterate over all klasses in dictionary
+   //   Just the classes from defining class loaders
+   static void classes_do(void f(klassOop));
++  static void classes_do(ObjectClosure *closure);
++  static void preloaded_classes_do(OopClosure *closure);
+   // Added for initialize_itable_for_klass to handle exceptions
+   static void classes_do(void f(klassOop, TRAPS), TRAPS);
+   //   All classes, and their class loaders
+@@ -416,6 +418,8 @@ public:
+     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
+   }
+ 
++  static void rollback_redefinition();
++
+ public:
+   #define WK_KLASS_DECLARE(name, symbol, option) \
+     static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); }
+@@ -597,11 +601,11 @@ private:
+   // after waiting, but before reentering SystemDictionary_lock
+   // to preserve lock order semantics.
+   static void double_lock_wait(Handle lockObject, TRAPS);
+-  static void define_instance_class(instanceKlassHandle k, TRAPS);
++  static void define_instance_class(instanceKlassHandle k, KlassHandle old_class, TRAPS);
+   static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
+                                                 Handle class_loader,
+                                                 instanceKlassHandle k, TRAPS);
+-  static instanceKlassHandle load_shared_class(Symbol* class_name,
++  static instanceKlassHandle load_shared_class(Symbol* class_name, // after waiting, but before reentering SystemDictionary_lock,
+                                                Handle class_loader, TRAPS);
+   static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
+                                                Handle class_loader, TRAPS);
+@@ -616,12 +620,16 @@ private:
+   // Setup link to hierarchy
+   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
+ 
++public:
++  // Remove link to hierarchy
++  static void remove_from_hierarchy(instanceKlassHandle k);
++
++private:
+   // event based tracing
+   static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
+                                     Handle initiating_loader);
+   static void post_class_unload_events(BoolObjectClosure* is_alive);
+ 
+-private:
+   // We pass in the hashtable index so we can calculate it outside of
+   // the SystemDictionary_lock.
+ 
+diff --git a/src/share/vm/classfile/verifier.cpp b/src/share/vm/classfile/verifier.cpp
+index 0dbe9dd..f4b22cc 100644
+--- a/src/share/vm/classfile/verifier.cpp
++++ b/src/share/vm/classfile/verifier.cpp
+@@ -106,7 +106,7 @@ bool Verifier::relax_verify_for(oop loader) {
+   return !need_verify;
+ }
+ 
+-bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool should_verify_class, TRAPS) {
++bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool should_verify_class, bool may_use_old_verifier, TRAPS) {
+   HandleMark hm;
+   ResourceMark rm(THREAD);
+ 
+@@ -117,7 +117,8 @@ bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool shoul
+ 
+   const char* klassName = klass->external_name();
+   bool can_failover = FailOverToOldVerifier &&
+-      klass->major_version() < NOFAILOVER_MAJOR_VERSION;
++      klass->major_version() < NOFAILOVER_MAJOR_VERSION &&
++      may_use_old_verifier;
+ 
+   // If the class should be verified, first see if we can use the split
+   // verifier.  If not, or if verification fails and FailOverToOldVerifier
+@@ -138,6 +139,7 @@ bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool shoul
+           tty->print_cr(
+             "Fail over class verification to old verifier for: %s", klassName);
+         }
++        assert(may_use_old_verifier, "");
+         exception_name = inference_verify(
+           klass, message_buffer, message_buffer_len, THREAD);
+       }
+@@ -145,6 +147,7 @@ bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool shoul
+         exception_message = split_verifier.exception_message();
+       }
+     } else {
++      assert(may_use_old_verifier, "");
+       exception_name = inference_verify(
+           klass, message_buffer, message_buffer_len, THREAD);
+     }
+@@ -159,6 +162,9 @@ bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool shoul
+       }
+       tty->print_cr("End class verification for: %s", klassName);
+     }
++  } else if (TraceClassInitialization) {
++    // (tw) Output not verified classes
++    tty->print_cr("Class %s was not verified", klassName);
+   }
+ 
+   if (HAS_PENDING_EXCEPTION) {
+@@ -210,7 +216,7 @@ bool Verifier::is_eligible_for_verification(instanceKlassHandle klass, bool shou
+     // NOTE: this is called too early in the bootstrapping process to be
+     // guarded by Universe::is_gte_jdk14x_version()/UseNewReflection.
+     (refl_magic_klass == NULL ||
+-     !klass->is_subtype_of(refl_magic_klass) ||
++     !(klass->is_subtype_of(refl_magic_klass) || klass->is_subtype_of(refl_magic_klass->klass_part()->newest_version())) ||
+      VerifyReflectionBytecodes)
+   );
+ }
+@@ -517,7 +523,7 @@ void ErrorContext::stackmap_details(outputStream* ss, methodOop method) const {
+ 
+ ClassVerifier::ClassVerifier(
+     instanceKlassHandle klass, TRAPS)
+-    : _thread(THREAD), _exception_type(NULL), _message(NULL), _klass(klass) {
++    : _thread(THREAD), _exception_type(NULL), _message(NULL), _klass(klass->newest_version()), _klass_to_verify(klass) {
+   _this_type = VerificationType::reference_type(klass->name());
+   // Create list to hold symbols in reference area.
+   _symbols = new GrowableArray<Symbol*>(100, 0, NULL);
+@@ -547,7 +553,7 @@ void ClassVerifier::verify_class(TRAPS) {
+       _klass->external_name());
+   }
+ 
+-  objArrayHandle methods(THREAD, _klass->methods());
++  objArrayHandle methods(THREAD, _klass_to_verify->methods());
+   int num_methods = methods->length();
+ 
+   for (int index = 0; index < num_methods; index++) {
+@@ -2475,7 +2481,10 @@ void ClassVerifier::verify_invoke_instructions(
+         VerificationType stack_object_type =
+           current_frame->pop_stack(ref_class_type, CHECK_VERIFY(this));
+         if (current_type() != stack_object_type) {
+-          assert(cp->cache() == NULL, "not rewritten yet");
++          
++          // (tw) TODO: Check if relaxing the following assertion is correct. For class redefinition we might call the verifier twice.
++          //assert(cp->cache() == NULL, "not rewritten yet");
++
+           Symbol* ref_class_name =
+             cp->klass_name_at(cp->klass_ref_index_at(index));
+           // See the comments in verify_field_instructions() for
+diff --git a/src/share/vm/classfile/verifier.hpp b/src/share/vm/classfile/verifier.hpp
+index 022c9b7..c495af4 100644
+--- a/src/share/vm/classfile/verifier.hpp
++++ b/src/share/vm/classfile/verifier.hpp
+@@ -47,7 +47,7 @@ class Verifier : AllStatic {
+    * Otherwise, no exception is thrown and the return indicates the
+    * error.
+    */
+-  static bool verify(instanceKlassHandle klass, Mode mode, bool should_verify_class, TRAPS);
++  static bool verify(instanceKlassHandle klass, Mode mode, bool should_verify_class, bool may_use_old_verifier, TRAPS);
+ 
+   // Return false if the class is loaded by the bootstrap loader,
+   // or if defineClass was called requesting skipping verification
+@@ -259,7 +259,10 @@ class ClassVerifier : public StackObj {
+   // Used to detect illegal jumps over calls to super() and this() in ctors.
+   int32_t _furthest_jump;
+ 
++public:
+   void verify_method(methodHandle method, TRAPS);
++
++private:
+   char* generate_code_data(methodHandle m, u4 code_length, TRAPS);
+   void verify_exception_handler_table(u4 code_length, char* code_data,
+                                       int& min, int& max, TRAPS);
+@@ -332,6 +335,7 @@ class ClassVerifier : public StackObj {
+ 
+   VerificationType object_type() const;
+ 
++  instanceKlassHandle _klass_to_verify;
+   instanceKlassHandle _klass;  // the class being verified
+   methodHandle        _method; // current method being verified
+   VerificationType    _this_type; // the verification type of the current class
+diff --git a/src/share/vm/classfile/vmSymbols.hpp b/src/share/vm/classfile/vmSymbols.hpp
+index 5b773da..b20086b 100644
+--- a/src/share/vm/classfile/vmSymbols.hpp
++++ b/src/share/vm/classfile/vmSymbols.hpp
+@@ -138,6 +138,10 @@
+   template(tag_annotation_default,                    "AnnotationDefault")                        \
+   template(tag_enclosing_method,                      "EnclosingMethod")                          \
+   template(tag_bootstrap_methods,                     "BootstrapMethods")                         \
++  template(tag_static_field_redefinition_policy,      "StaticFieldRedefinitionPolicy")            \
++  template(tag_field_redefinition_policy,             "FieldRedefinitionPolicy")                  \
++  template(tag_method_redefinition_policy,            "MethodRedefinitionPolicy")                 \
++  template(tag_code_sections,                         "CodeSections")                             \
+                                                                                                   \
+   /* exception klasses: at least all exceptions thrown by the VM have entries here */             \
+   template(java_lang_ArithmeticException,             "java/lang/ArithmeticException")            \
+@@ -379,6 +383,10 @@
+   template(oop_size_name,                             "oop_size")                                 \
+   template(static_oop_field_count_name,               "static_oop_field_count")                   \
+                                                                                                   \
++  /* mutator in case of class redefinition */                                                     \
++  template(static_transformer_name,                   "$staticTransformer")                       \
++  template(transformer_name,                          "$transformer")                             \
++                                                                                                  \
+   /* non-intrinsic name/signature pairs: */                                                       \
+   template(register_method_name,                      "register")                                 \
+   do_alias(register_method_signature,         object_void_signature)                              \
+diff --git a/src/share/vm/compiler/compileBroker.cpp b/src/share/vm/compiler/compileBroker.cpp
+index 3e8a65a..fe96a94 100644
+--- a/src/share/vm/compiler/compileBroker.cpp
++++ b/src/share/vm/compiler/compileBroker.cpp
+@@ -1181,6 +1181,14 @@ nmethod* CompileBroker::compile_method(methodHandle method, int osr_bci,
+                                        int comp_level,
+                                        methodHandle hot_method, int hot_count,
+                                        const char* comment, Thread* THREAD) {
++  JavaThread* thread = JavaThread::current();
++  if (thread->is_Compiler_thread() && thread->as_CompilerThread()->should_bailout()) {
++    return NULL; // FIXME: DCEVM: should we do something else?
++  }
++  if (instanceKlass::cast(method->method_holder())->is_not_initialized()) {
++    return NULL; // FIXME: DCEVM: how should we avoid this?
++  }
++
+   // make sure arguments make sense
+   assert(method->method_holder()->klass_part()->oop_is_instance(), "not an instance method");
+   assert(osr_bci == InvocationEntryBci || (0 <= osr_bci && osr_bci < method->code_size()), "bci out of range");
+@@ -1260,6 +1268,7 @@ nmethod* CompileBroker::compile_method(methodHandle method, int osr_bci,
+   }
+ 
+   // RedefineClasses() has replaced this method; just return
++  // (tw) This is important for the new version of hotswapping: Old code will only execute properly in the interpreter!
+   if (method->is_old()) {
+     return NULL;
+   }
+@@ -1592,6 +1601,8 @@ void CompileBroker::compiler_thread_loop() {
+ 
+       // Never compile a method if breakpoints are present in it
+       if (method()->number_of_breakpoints() == 0) {
++        thread->compilation_mutex()->lock();
++        thread->set_should_bailout(false);
+         // Compile the method.
+         if ((UseCompiler || AlwaysCompileLoopMethods) && CompileBroker::should_compile_new_jobs()) {
+ #ifdef COMPILER1
+@@ -1615,6 +1626,7 @@ void CompileBroker::compiler_thread_loop() {
+           // After compilation is disabled, remove remaining methods from queue
+           method->clear_queued_for_compilation();
+         }
++        thread->compilation_mutex()->unlock();
+       }
+     }
+   }
+@@ -2165,3 +2177,15 @@ void CompileBroker::print_compiler_threads_on(outputStream* st) {
+   st->cr();
+ #endif
+ }
++
++// (tw) Clean up compiler interface after a class redefinition step
++void CompileBroker::cleanup_after_redefinition() {
++  int num_threads = _method_threads->length();
++
++  ciObjectFactory::sort_ci_objects(ciObjectFactory::_shared_ci_objects);
++  for (int i=0; i<num_threads; i++) {
++    if (_method_threads->at(i)->env() != NULL && _method_threads->at(i)->env() != (ciEnv *)badAddress) {
++      _method_threads->at(i)->env()->cleanup_after_redefinition();
++    }
++  }
++}
+diff --git a/src/share/vm/compiler/compileBroker.hpp b/src/share/vm/compiler/compileBroker.hpp
+index 29f2b22..37989d1 100644
+--- a/src/share/vm/compiler/compileBroker.hpp
++++ b/src/share/vm/compiler/compileBroker.hpp
+@@ -408,6 +408,7 @@ class CompileBroker: AllStatic {
+ 
+   static void print_compiler_threads_on(outputStream* st);
+ 
++  static void cleanup_after_redefinition();
+   static int get_total_compile_count() {          return _total_compile_count; }
+   static int get_total_bailout_count() {          return _total_bailout_count; }
+   static int get_total_invalidated_count() {      return _total_invalidated_count; }
+diff --git a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
+index b0c9ec8..b3298e0 100644
+--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
++++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
+@@ -162,6 +162,13 @@ CompactibleFreeListSpace::CompactibleFreeListSpace(BlockOffsetSharedArray* bs,
+   }
+ }
+ 
++
++HeapWord* CompactibleFreeListSpace::forward_compact_top(size_t size,
++                                    CompactPoint* cp, HeapWord* compact_top) {
++  ShouldNotReachHere();
++  return NULL;
++}
++
+ // Like CompactibleSpace forward() but always calls cross_threshold() to
+ // update the block offset table.  Removed initialize_threshold call because
+ // CFLS does not use a block offset array for contiguous spaces.
+diff --git a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
+index 3b7bb9a..de7e54b 100644
+--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
++++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
+@@ -149,6 +149,7 @@ class CompactibleFreeListSpace: public CompactibleSpace {
+ 
+   // Support for compacting cms
+   HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
++  HeapWord* forward_compact_top(size_t size, CompactPoint* cp, HeapWord* compact_top);
+   HeapWord* forward(oop q, size_t size, CompactPoint* cp, HeapWord* compact_top);
+ 
+   // Initialization helpers.
+diff --git a/src/share/vm/gc_implementation/shared/markSweep.cpp b/src/share/vm/gc_implementation/shared/markSweep.cpp
+index 29841d8..a13a35d 100644
+--- a/src/share/vm/gc_implementation/shared/markSweep.cpp
++++ b/src/share/vm/gc_implementation/shared/markSweep.cpp
+@@ -32,6 +32,8 @@
+ #include "oops/objArrayKlass.inline.hpp"
+ #include "oops/oop.inline.hpp"
+ 
++GrowableArray<oop>*           MarkSweep::_rescued_oops       = NULL;
++
+ Stack<oop, mtGC>              MarkSweep::_marking_stack;
+ Stack<DataLayout*, mtGC>      MarkSweep::_revisit_mdo_stack;
+ Stack<Klass*, mtGC>           MarkSweep::_revisit_klass_stack;
+@@ -357,3 +359,86 @@ void MarkSweep::trace(const char* msg) {
+ }
+ 
+ #endif
++
++// (tw) Copy the rescued objects to their destination address after compaction.
++void MarkSweep::copy_rescued_objects_back() {
++
++  if (_rescued_oops != NULL) {
++
++    for (int i=0; i<_rescued_oops->length(); i++) {
++      oop rescued_obj = _rescued_oops->at(i);
++
++      int size = rescued_obj->size();
++      oop new_obj = rescued_obj->forwardee();
++
++      if (rescued_obj->blueprint()->new_version() != NULL) {
++        MarkSweep::update_fields(rescued_obj, new_obj);
++      } else {
++        Copy::aligned_disjoint_words((HeapWord*)rescued_obj, (HeapWord*)new_obj, size);
++      }
++
++      FREE_RESOURCE_ARRAY(HeapWord, rescued_obj, size);
++
++      new_obj->init_mark();
++      assert(new_obj->is_oop(), "must be a valid oop");
++    }
++    _rescued_oops->clear();
++    _rescued_oops = NULL;
++  }
++}
++
++// (tw) Update instances of a class whose fields changed.
++void MarkSweep::update_fields(oop q, oop new_location) {
++
++  assert(q->blueprint()->new_version() != NULL, "class of old object must have new version");
++
++  klassOop old_klass_oop = q->klass();
++  klassOop new_klass_oop = q->blueprint()->new_version();
++
++  instanceKlass *old_klass = instanceKlass::cast(old_klass_oop);
++  instanceKlass *new_klass = instanceKlass::cast(new_klass_oop);
++
++  int size = q->size_given_klass(old_klass);
++  int new_size = q->size_given_klass(new_klass);
++  
++  oop tmp_obj = q;
++
++  if (new_klass_oop->klass_part()->is_copying_backwards()) {
++    if (((HeapWord *)q >= (HeapWord *)new_location && (HeapWord *)q < (HeapWord *)new_location + new_size) || 
++        ((HeapWord *)new_location >= (HeapWord *)q && (HeapWord *)new_location < (HeapWord *)q + size)) {
++       tmp_obj = (oop)resource_allocate_bytes(size * HeapWordSize);
++       Copy::aligned_disjoint_words((HeapWord*)q, (HeapWord*)tmp_obj, size);
++    }
++  }
++  
++  int *cur = new_klass_oop->klass_part()->update_information();
++
++  tmp_obj->set_klass_no_check(new_klass_oop);
++
++  if (cur == NULL) {
++    assert(size == new_size, "just checking");
++    Copy::conjoint_words(((HeapWord *)tmp_obj), ((HeapWord *)new_location), size);
++  } else {
++    int destOffset = 0;
++    while (*cur != 0) {
++      if (*cur > 0) {
++        int size = *cur;
++        cur++;
++        int offset = *cur;
++        Copy::conjoint_jbytes(((char *)tmp_obj) + offset, ((char *)new_location) + destOffset, size);
++        destOffset += size;
++        cur++;
++      } else {
++        assert(*cur < 0, "");
++        int skip = -*cur;
++        Copy::fill_to_bytes(((char*)new_location) + destOffset, skip, 0);
++        destOffset += skip;
++        cur++;
++      }
++    }
++  }
++
++  if (tmp_obj != q) {
++    FREE_RESOURCE_ARRAY(HeapWord, tmp_obj, size);
++  }
++}
+diff --git a/src/share/vm/gc_implementation/shared/markSweep.hpp b/src/share/vm/gc_implementation/shared/markSweep.hpp
+index eb8252c..b96a677 100644
+--- a/src/share/vm/gc_implementation/shared/markSweep.hpp
++++ b/src/share/vm/gc_implementation/shared/markSweep.hpp
+@@ -117,8 +117,12 @@ class MarkSweep : AllStatic {
+   friend class AdjustPointerClosure;
+   friend class KeepAliveClosure;
+   friend class VM_MarkSweep;
++  friend class GenMarkSweep;
+   friend void marksweep_init();
+ 
++public:
++  static GrowableArray<oop>*             _rescued_oops;
++
+   //
+   // Vars
+   //
+@@ -208,6 +212,8 @@ class MarkSweep : AllStatic {
+   template <class T> static inline void mark_and_push(T* p);
+   static inline void push_objarray(oop obj, size_t index);
+ 
++  static void copy_rescued_objects_back();
++  static void update_fields(oop q, oop new_location);
+   static void follow_stack();   // Empty marking stack.
+ 
+   static void preserve_mark(oop p, markOop mark);
+diff --git a/src/share/vm/interpreter/interpreterRuntime.cpp b/src/share/vm/interpreter/interpreterRuntime.cpp
+index 1a1af1b..94972f0 100644
+--- a/src/share/vm/interpreter/interpreterRuntime.cpp
++++ b/src/share/vm/interpreter/interpreterRuntime.cpp
+@@ -402,7 +402,7 @@ IRT_ENTRY(address, InterpreterRuntime::exception_handler_for_exception(JavaThrea
+     assert(h_exception.not_null(), "NULL exceptions should be handled by athrow");
+     assert(h_exception->is_oop(), "just checking");
+     // Check that exception is a subclass of Throwable, otherwise we have a VerifyError
+-    if (!(h_exception->is_a(SystemDictionary::Throwable_klass()))) {
++    if (!(h_exception->is_a(SystemDictionary::Throwable_klass()->klass_part()->newest_version())) && !(h_exception->is_a(SystemDictionary::Throwable_klass()))) {
+       if (ExitVMOnVerifyError) vm_exit(-1);
+       ShouldNotReachHere();
+     }
+@@ -656,6 +656,82 @@ IRT_ENTRY(void, InterpreterRuntime::_breakpoint(JavaThread* thread, methodOopDes
+   JvmtiExport::post_raw_breakpoint(thread, method, bcp);
+ IRT_END
+ 
++// (tw) Correctly resolve method when running old code.
++IRT_ENTRY(void, InterpreterRuntime::forward_method(JavaThread *thread))
++  {
++    MonitorLockerEx ml(RedefinitionSync_lock);
++    while (Threads::wait_at_instrumentation_entry()) {
++      ml.wait();
++    }
++  }
++  frame f = last_frame(thread);
++  methodOop m = f.interpreter_frame_method();
++  methodOop forward_method = m->forward_method();
++  if (forward_method != NULL) {
++    int bci = f.interpreter_frame_bci();
++    
++    if (TraceRedefineClasses >= 3) {
++      tty->print_cr("Executing NOP in method %s at bci %d %d", m->name()->as_C_string(), bci, m->is_in_code_section(bci + 1));
++    }
++
++    int next_bci = bci - 1;
++    // First try bci before NOP.
++    if (!m->is_in_code_section(next_bci)) {
++      // Try bci after NOP.
++      next_bci = bci + 1;
++      if (!m->is_in_code_section(next_bci)) return;
++    }
++    
++    int new_bci = m->calculate_forward_bci(next_bci, forward_method);
++    if (TraceRedefineClasses >= 2) {
++      tty->print_cr("Transferring execution of %s to new method old_bci=%d new_bci=%d", forward_method->name()->as_C_string(), bci, new_bci);
++    }
++    RegisterMap reg_map(thread);
++    vframe* vf = vframe::new_vframe(&f, &reg_map, thread);
++    interpretedVFrame *iframe = (interpretedVFrame *)vf;
++    iframe->set_method(forward_method, new_bci - 1);
++  }
++IRT_END
++
++// (tw) Correctly resolve method when running old code.
++IRT_ENTRY(void, InterpreterRuntime::find_correct_method(JavaThread *thread, oopDesc* receiverOop, int vTableIndex))
++  // extract receiver from the outgoing argument list if necessary
++  Handle receiver(thread, receiverOop);
++
++  // TODO: Check for invokeinterface!
++  Bytecodes::Code bytecode = Bytecodes::_invokevirtual;
++
++  int method_holder_revision_number = method(thread)->method_holder()->klass_part()->revision_number();
++  klassOop klass = receiverOop->klass();
++  while (klass->klass_part()->revision_number() > method_holder_revision_number) {
++    klass = klass->klass_part()->old_version();
++  }
++
++  // TODO: Check for correctness if different vtable indices in different versions?
++
++  methodOop method = ((instanceKlass *)klass->klass_part())->method_at_vtable(vTableIndex);
++  thread->set_vm_result(method);
++IRT_END
++
++// Correctly resolve interface method when running old code.
++IRT_ENTRY(void, InterpreterRuntime::find_correct_interface_method(JavaThread *thread, oopDesc* receiverOop, oopDesc* interface_klass, int vTableIndex))
++
++  // extract receiver from the outgoing argument list if necessary
++  Handle receiver(thread, receiverOop);
++
++  // TODO: Check for invokeinterface!
++  Bytecodes::Code bytecode = Bytecodes::_invokevirtual;
++
++  int method_holder_revision_number = method(thread)->method_holder()->klass_part()->revision_number();
++  klassOop klass = receiverOop->klass();
++  while (klass->klass_part()->revision_number() > method_holder_revision_number) {
++    klass = klass->klass_part()->old_version();
++  }
++
++  methodOop method = ((instanceKlass *)klass->klass_part())->method_at_itable((klassOop)interface_klass, vTableIndex, THREAD);
++  thread->set_vm_result(method);
++IRT_END
++
+ IRT_ENTRY(void, InterpreterRuntime::resolve_invoke(JavaThread* thread, Bytecodes::Code bytecode)) {
+   // extract receiver from the outgoing argument list if necessary
+   Handle receiver(thread, NULL);
+@@ -684,6 +760,10 @@ IRT_ENTRY(void, InterpreterRuntime::resolve_invoke(JavaThread* thread, Bytecodes
+     if (JvmtiExport::can_hotswap_or_post_breakpoint()) {
+       int retry_count = 0;
+       while (info.resolved_method()->is_old()) {
++        // (tw) If we are executing an old method, this is OK!
++        if (method(thread)->is_old()) {
++          break;
++        }
+         // It is very unlikely that method is redefined more than 100 times
+         // in the middle of resolve. If it is looping here more than 100 times
+         // means then there could be a bug here.
+diff --git a/src/share/vm/interpreter/interpreterRuntime.hpp b/src/share/vm/interpreter/interpreterRuntime.hpp
+index 6d5f13a..50fa219 100644
+--- a/src/share/vm/interpreter/interpreterRuntime.hpp
++++ b/src/share/vm/interpreter/interpreterRuntime.hpp
+@@ -141,6 +141,9 @@ class InterpreterRuntime: AllStatic {
+   static void post_method_entry(JavaThread *thread);
+   static void post_method_exit (JavaThread *thread);
+   static int  interpreter_contains(address pc);
++  static void forward_method(JavaThread *thread);
++  static void find_correct_method(JavaThread *thread, oopDesc* receiver, int vTableIndex);
++  static void find_correct_interface_method(JavaThread *thread, oopDesc* receiver, oopDesc* interface_klass, int vTableIndex);
+ 
+   // Native signature handlers
+   static void prepare_native_call(JavaThread* thread, methodOopDesc* method);
+diff --git a/src/share/vm/interpreter/linkResolver.cpp b/src/share/vm/interpreter/linkResolver.cpp
+index 1676add..ccd5241 100644
+--- a/src/share/vm/interpreter/linkResolver.cpp
++++ b/src/share/vm/interpreter/linkResolver.cpp
+@@ -153,8 +153,8 @@ void CallInfo::set_common(KlassHandle resolved_klass, KlassHandle selected_klass
+ // Klass resolution
+ 
+ void LinkResolver::check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS) {
+-  if (!Reflection::verify_class_access(ref_klass->as_klassOop(),
+-                                       sel_klass->as_klassOop(),
++  if (!Reflection::verify_class_access(ref_klass->as_klassOop()->klass_part()->newest_version(),
++                                       sel_klass->as_klassOop()->klass_part()->newest_version(),
+                                        true)) {
+     ResourceMark rm(THREAD);
+     Exceptions::fthrow(
+@@ -346,7 +346,7 @@ void LinkResolver::check_method_accessability(KlassHandle ref_klass,
+   // We'll check for the method name first, as that's most likely
+   // to be false (so we'll short-circuit out of these tests).
+   if (sel_method->name() == vmSymbols::clone_name() &&
+-      sel_klass() == SystemDictionary::Object_klass() &&
++      sel_klass()->klass_part()->newest_version() == SystemDictionary::Object_klass()->klass_part()->newest_version() &&
+       resolved_klass->oop_is_array()) {
+     // We need to change "protected" to "public".
+     assert(flags.is_protected(), "clone not protected?");
+@@ -412,48 +412,169 @@ void LinkResolver::resolve_method_statically(methodHandle& resolved_method, Klas
+   }
+ }
+ 
+-void LinkResolver::resolve_method(methodHandle& resolved_method, KlassHandle resolved_klass,
+-                                  Symbol* method_name, Symbol* method_signature,
+-                                  KlassHandle current_klass, bool check_access, TRAPS) {
+ 
+-  // 1. check if klass is not interface
+-  if (resolved_klass->is_interface()) {
+-    ResourceMark rm(THREAD);
+-    char buf[200];
+-    jio_snprintf(buf, sizeof(buf), "Found interface %s, but class was expected", Klass::cast(resolved_klass())->external_name());
+-    THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);
++void LinkResolver::lookup_method(methodHandle& resolved_method, KlassHandle resolved_klass,
++                   Symbol* method_name, Symbol* method_signature, bool is_interface, KlassHandle current_klass, TRAPS) {
++
++   // Interface method lookup?
++   if (is_interface) {
++
++     // lookup method in this interface or its super, java.lang.Object
++     lookup_instance_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++
++     if (resolved_method.is_null() && !resolved_klass->oop_is_array()) {
++       // lookup method in all the super-interfaces
++       lookup_method_in_interfaces(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++     }
++
++   // Other methods
++   } else {
++    Handle nested_exception;
++
++    // 2. lookup method in resolved klass and its super klasses
++    lookup_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++
++    if (resolved_method.is_null() && !resolved_klass->oop_is_array()) { // not found in the class hierarchy
++      // 3. lookup method in all the interfaces implemented by the resolved klass
++      lookup_method_in_interfaces(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++
++      if (resolved_method.is_null()) {
++        // JSR 292:  see if this is an implicitly generated method MethodHandle.linkToVirtual(*...), etc
++        lookup_polymorphic_method(resolved_method, resolved_klass, method_name, method_signature,
++                                  current_klass, (Handle*)NULL, (Handle*)NULL, THREAD);
++        if (HAS_PENDING_EXCEPTION) {
++          nested_exception = Handle(THREAD, PENDING_EXCEPTION);
++          CLEAR_PENDING_EXCEPTION;
++        }
++      }
++    }
+   }
++}
+ 
+-  Handle nested_exception;
++void LinkResolver::lookup_correct_field(fieldDescriptor &fd, KlassHandle &sel_klass, KlassHandle resolved_klass, KlassHandle current_klass, Symbol* field_name, Symbol* field_sig, bool is_static) {
+ 
+-  // 2. lookup method in resolved klass and its super klasses
+-  lookup_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++  // First attempt unversioned
++  sel_klass = KlassHandle(Thread::current(), resolved_klass->find_field(field_name, field_sig, &fd));
+ 
+-  if (resolved_method.is_null() && !resolved_klass->oop_is_array()) { // not found in the class hierarchy
+-    // 3. lookup method in all the interfaces implemented by the resolved klass
+-    lookup_method_in_interfaces(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++  if (!current_klass.is_null() && !current_klass->is_newest_version()) {
++
++    // Look for the policy defined in the new version of the class (_not_ in the newest, but only in the newer relative to current klass).
++    int redefinition_policy = current_klass->new_version()->klass_part()->field_redefinition_policy();
++    if (is_static) {
++      redefinition_policy = current_klass->new_version()->klass_part()->static_field_redefinition_policy();
++    }
++
++    assert(redefinition_policy != Klass::StaticCheck, "if the policy is static check, then we can never reach here");
++
++    if (redefinition_policy != Klass::DynamicCheck) {
++
++      if (redefinition_policy == Klass::AccessOldMembers) {
++        // Forget looked up fields
++        sel_klass = KlassHandle(Thread::current(), (oop)NULL);
++      }
++
++      assert(redefinition_policy == Klass::AccessOldMembers || redefinition_policy == Klass::AccessDeletedMembers, "");
++
++      if (sel_klass.is_null() || fd.is_static() != is_static /* access old static field field is changed from static to non-static */) {
++
++        // Select correct version for resolved klass.
++        find_correct_resolved_klass(resolved_klass, current_klass);
++
++        sel_klass = KlassHandle(Thread::current(), instanceKlass::cast(resolved_klass())->find_field(field_name, field_sig, &fd));
+ 
+-    if (resolved_method.is_null()) {
+-      // JSR 292:  see if this is an implicitly generated method MethodHandle.linkToVirtual(*...), etc
+-      lookup_polymorphic_method(resolved_method, resolved_klass, method_name, method_signature,
+-                                current_klass, (Handle*)NULL, (Handle*)NULL, THREAD);
+-      if (HAS_PENDING_EXCEPTION) {
+-        nested_exception = Handle(THREAD, PENDING_EXCEPTION);
+-        CLEAR_PENDING_EXCEPTION;
++        // FIXME: idubrov
++        //if (sel_klass.is_null()) {
++        //  TRACE_RC2("Trying to resolve field (%s) in old universe failed => exception is the correct behaviour", field_name->as_C_string());
++        //} else {
++        //  assert(sel_klass->new_version() != NULL, "must be old class!");
++        //  TRACE_RC2("Resolved a field in the old universe (%s)!", field_name->as_C_string());
++        //}
+       }
+     }
+   }
++}
+ 
+-  if (resolved_method.is_null()) {
+-    // 4. method lookup failed
++void LinkResolver::lookup_correct_method(methodHandle& resolved_method, KlassHandle resolved_klass, KlassHandle current_klass,
++                                 Symbol* method_name, Symbol* method_signature, bool is_interface, TRAPS) {
++
++   // First attempt unversioned
++   lookup_method(resolved_method, resolved_klass, method_name, method_signature, is_interface, current_klass, CHECK);
++
++   // (tw) Are we in an old method that wants to see a different view on the world?
++   if (!current_klass.is_null() && !current_klass->is_newest_version()) {
++
++     // Look for the policy defined in the new version of the class (_not_ in the newest, but only in the newer relative to current klass).
++     int method_redefinition_policy = current_klass->new_version()->klass_part()->method_redefinition_policy();
++     assert(method_redefinition_policy != Klass::StaticCheck, "if the policy is static check, then we can never reach here");
++
++     if (method_redefinition_policy != Klass::DynamicCheck) {
++
++       // We do not throw the exception
++       if (method_redefinition_policy == Klass::AccessOldMembers) {
++         // Forget any new member lookup
++         resolved_method = methodHandle(THREAD, NULL);
++       }
++
++       assert(method_redefinition_policy == Klass::AccessOldMembers || method_redefinition_policy == Klass::AccessDeletedMembers, "");
++
++       if (resolved_method.is_null()) {
++
++         // Select correct version for resolved klass.
++         find_correct_resolved_klass(resolved_klass, current_klass);
++
++         // Now do the lookup in a second attempt with a different resolved klass.
++         lookup_method(resolved_method, resolved_klass, method_name, method_signature, is_interface, current_klass, CHECK);
++
++         // FIXME: idubrov
++         //IF_TRACE_RC2 {
++         //  ResourceMark rm(THREAD);
++         //  if (resolved_method.is_null()) {
++         //    TRACE_RC2("Trying to resolve method (%s) in old universe failed => exception is the correct behaviour", method_name->as_C_string());
++         //  } else {
++         //    assert(resolved_method->is_old(), "must be old method!");
++         //    TRACE_RC2("Resolved a method in the old universe (%s)!", resolved_method->name()->as_C_string());
++         //  }
++         //}
++       }
++     }
++   }
++
++   if (resolved_method.is_null()) {
++     // no method found
++     ResourceMark rm(THREAD);
++     THROW_MSG(vmSymbols::java_lang_NoSuchMethodError(),
++       methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),
++       method_name,
++       method_signature));
++   }
++}
++
++void LinkResolver::find_correct_resolved_klass(KlassHandle &resolved_klass, KlassHandle &current_klass) {
++  int current_klass_revision = current_klass->revision_number();
++  int resolved_klass_revision = resolved_klass->revision_number();
++  // FIXME: idubrov
++  //TRACE_RC2("The two different revision numbers for interfaces: current=%d / resolved_callee=%d", current_klass_revision, resolved_klass_revision);
++
++  while (resolved_klass->revision_number() > current_klass_revision) {
++    assert(resolved_klass->old_version(), "must have old version");
++	resolved_klass = KlassHandle(Thread::current(), resolved_klass->old_version());
++  }
++}
++void LinkResolver::resolve_method(methodHandle& resolved_method, KlassHandle resolved_klass,
++                                  Symbol* method_name, Symbol* method_signature,
++                                  KlassHandle current_klass, bool check_access, TRAPS) {
++
++  // 1. check if klass is not interface
++  if (resolved_klass->is_interface()) {
+     ResourceMark rm(THREAD);
+-    THROW_MSG_CAUSE(vmSymbols::java_lang_NoSuchMethodError(),
+-                    methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),
+-                                                            method_name,
+-                                                            method_signature),
+-                    nested_exception);
++    char buf[200];
++    jio_snprintf(buf, sizeof(buf), "Found interface %s, but class was expected", Klass::cast(resolved_klass())->external_name());
++    THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);
+   }
+ 
++  // 2. and 3. and 4. lookup method in resolved klass and its super klasses
++  lookup_correct_method(resolved_method, resolved_klass, current_klass, method_name, method_signature, false, CHECK);
++
+   // 5. check if method is concrete
+   if (resolved_method->is_abstract() && !resolved_klass->is_abstract()) {
+     ResourceMark rm(THREAD);
+@@ -520,7 +641,10 @@ void LinkResolver::resolve_interface_method(methodHandle& resolved_method,
+   }
+ 
+   // lookup method in this interface or its super, java.lang.Object
+-  lookup_instance_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);
++  lookup_correct_method(resolved_method, resolved_klass, current_klass, method_name, method_signature, true, CHECK);
++
++
++
+ 
+   if (resolved_method.is_null() && !resolved_klass->oop_is_array()) {
+     // lookup method in all the super-interfaces
+@@ -621,9 +745,14 @@ void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle poo
+     THROW_MSG(vmSymbols::java_lang_NoSuchFieldError(), field->as_C_string());
+   }
+ 
++  KlassHandle ref_klass(THREAD, pool->pool_holder()->klass_part());
++
+   // Resolve instance field
+   fieldDescriptor fd; // find_field initializes fd if found
+-  KlassHandle sel_klass(THREAD, resolved_klass->find_field(field, sig, &fd));
++
++  KlassHandle sel_klass;
++  lookup_correct_field(fd, sel_klass, resolved_klass, ref_klass, field, sig, is_static);
++
+   // check if field exists; i.e., if a klass containing the field def has been selected
+   if (sel_klass.is_null()){
+     ResourceMark rm(THREAD);
+@@ -631,7 +760,6 @@ void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle poo
+   }
+ 
+   // check access
+-  KlassHandle ref_klass(THREAD, pool->pool_holder());
+   check_field_accessability(ref_klass, resolved_klass, sel_klass, fd, CHECK);
+ 
+   // check for errors
+@@ -643,7 +771,7 @@ void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle poo
+   }
+ 
+   // Final fields can only be accessed from its own class.
+-  if (is_put && fd.access_flags().is_final() && sel_klass() != pool->pool_holder()) {
++  if (is_put && fd.access_flags().is_final() && sel_klass() != pool->pool_holder()->klass_part()->active_version() && sel_klass() != pool->pool_holder()) {
+     THROW(vmSymbols::java_lang_IllegalAccessError());
+   }
+ 
+@@ -848,7 +976,7 @@ void LinkResolver::resolve_virtual_call(CallInfo& result, Handle recv, KlassHand
+                                         bool check_access, bool check_null_and_abstract, TRAPS) {
+   methodHandle resolved_method;
+   linktime_resolve_virtual_method(resolved_method, resolved_klass, method_name, method_signature, current_klass, check_access, CHECK);
+-  runtime_resolve_virtual_method(result, resolved_method, resolved_klass, recv, receiver_klass, check_null_and_abstract, CHECK);
++  runtime_resolve_virtual_method(result, resolved_method, resolved_klass, recv, receiver_klass, current_klass, check_null_and_abstract, CHECK);
+ }
+ 
+ // throws linktime exceptions
+@@ -878,6 +1006,7 @@ void LinkResolver::runtime_resolve_virtual_method(CallInfo& result,
+                                                   KlassHandle resolved_klass,
+                                                   Handle recv,
+                                                   KlassHandle recv_klass,
++                                                  KlassHandle current_klass,
+                                                   bool check_null_and_abstract,
+                                                   TRAPS) {
+ 
+@@ -926,10 +1055,44 @@ void LinkResolver::runtime_resolve_virtual_method(CallInfo& result,
+       // recv_klass might be an arrayKlassOop but all vtables start at
+       // the same place. The cast is to avoid virtual call and assertion.
+       instanceKlass* inst = (instanceKlass*)recv_klass()->klass_part();
+-      selected_method = methodHandle(THREAD, inst->method_at_vtable(vtable_index));
++
++      // (tw) The type of the virtual method call and the type of the receiver do not need to
++      // have anything in common, as the receiver type could've been hotswapped.
++      // Does not always work (method could be resolved with correct dynamic type and later
++      // be called at the same place with a wrong dynamic type).
++      // (tw) TODO: Need to handle the static type vs dynamic type issue more generally.
++
++      // The vTable must be based on the view of the world of the resolved method
++      klassOop method_holder = resolved_method->method_holder();
++
++      if (method_holder->klass_part()->new_version() != NULL) {
++        // We are executing in old code
++        // FIXME: idubrov
++        //TRACE_RC2("Calling a method in old code");
++        while (method_holder->klass_part()->revision_number() < inst->revision_number()) {
++          inst = (instanceKlass *)(inst->old_version()->klass_part());
++        }
++      }
++
++      if (inst->is_subtype_of(method_holder)) {
++        selected_method = methodHandle(THREAD, inst->method_at_vtable(vtable_index));
++      } else {
++
++        tty->print_cr("Failure:");
++        inst->as_klassOop()->print();
++        inst->super()->print();
++        juint    off = inst->super_check_offset();
++        klassOop sup = *(klassOop*)( (address)inst->as_klassOop() + off );
++        sup->print();
++        method_holder->print();
++
++        bool b = inst->is_subtype_of(method_holder);
++        THROW_MSG(vmSymbols::java_lang_NoSuchMethodError(), "(tw) A virtual method was called, but the type of the receiver is not related with the type of the class of the called method!");
++      }
+     }
+   }
+ 
++
+   // check if method exists
+   if (selected_method.is_null()) {
+     ResourceMark rm(THREAD);
+diff --git a/src/share/vm/interpreter/linkResolver.hpp b/src/share/vm/interpreter/linkResolver.hpp
+index dfd74f9..cf6e44a 100644
+--- a/src/share/vm/interpreter/linkResolver.hpp
++++ b/src/share/vm/interpreter/linkResolver.hpp
+@@ -110,7 +110,11 @@ class CallInfo: public LinkInfo {
+ // It does all necessary link-time checks & throws exceptions if necessary.
+ 
+ class LinkResolver: AllStatic {
+- private:
++private:
++  static void lookup_method                     (methodHandle& result, KlassHandle resolved_klass, Symbol* name, Symbol* signature, bool is_interface, KlassHandle current_klass, TRAPS);
++  static void lookup_correct_field				(fieldDescriptor &fd, KlassHandle &sel_klass, KlassHandle resolved_klass, KlassHandle current_klass, Symbol* field_name, Symbol* field_sig, bool is_static);
++  static void lookup_correct_method             (methodHandle& result, KlassHandle resolved_klass, KlassHandle current_klass, Symbol* name, Symbol* signature, bool is_interface, TRAPS);
++  static void find_correct_resolved_klass       (KlassHandle &resolved_klass, KlassHandle &current_klass);
+   static void lookup_method_in_klasses          (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
+   static void lookup_instance_method_in_klasses (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
+   static void lookup_method_in_interfaces       (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
+@@ -133,7 +137,7 @@ class LinkResolver: AllStatic {
+   static void linktime_resolve_interface_method (methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, TRAPS);
+ 
+   static void runtime_resolve_special_method    (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, KlassHandle current_klass, bool check_access, TRAPS);
+-  static void runtime_resolve_virtual_method    (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, Handle recv, KlassHandle recv_klass, bool check_null_and_abstract, TRAPS);
++  static void runtime_resolve_virtual_method    (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, Handle recv, KlassHandle recv_klass, KlassHandle current_klass, bool check_null_and_abstract, TRAPS);
+   static void runtime_resolve_interface_method  (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, Handle recv, KlassHandle recv_klass, bool check_null_and_abstract, TRAPS);
+ 
+   static void check_field_accessability   (KlassHandle ref_klass, KlassHandle resolved_klass, KlassHandle sel_klass, fieldDescriptor& fd, TRAPS);
+diff --git a/src/share/vm/interpreter/templateTable.hpp b/src/share/vm/interpreter/templateTable.hpp
+index 17e9f26..e77500f 100644
+--- a/src/share/vm/interpreter/templateTable.hpp
++++ b/src/share/vm/interpreter/templateTable.hpp
+@@ -329,8 +329,8 @@ class TemplateTable: AllStatic {
+   static void shouldnotreachhere();
+ 
+   // jvmti support
+-  static void jvmti_post_field_access(Register cache, Register index, bool is_static, bool has_tos);
+-  static void jvmti_post_field_mod(Register cache, Register index, bool is_static);
++  static void jvmti_post_field_access(Register cache, Register index, int byte_no, bool is_static, bool has_tos);
++  static void jvmti_post_field_mod(Register cache, Register index, int byte_no, bool is_static);
+   static void jvmti_post_fast_field_mod();
+ 
+   // debugging of TemplateGenerator
+diff --git a/src/share/vm/memory/genMarkSweep.cpp b/src/share/vm/memory/genMarkSweep.cpp
+index 76e18d8..6af7c14 100644
+--- a/src/share/vm/memory/genMarkSweep.cpp
++++ b/src/share/vm/memory/genMarkSweep.cpp
+@@ -421,6 +421,7 @@ void GenMarkSweep::mark_sweep_phase4() {
+   // in the same order in phase2, phase3 and phase4. We don't quite do that
+   // here (perm_gen first rather than last), so we tell the validate code
+   // to use a higher index (saved from phase2) when verifying perm_gen.
++  assert(_rescued_oops == NULL, "must be empty before processing");
+   GenCollectedHeap* gch = GenCollectedHeap::heap();
+   Generation* pg = gch->perm_gen();
+ 
+@@ -433,10 +434,14 @@ void GenMarkSweep::mark_sweep_phase4() {
+ 
+   VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false));
+ 
++  MarkSweep::copy_rescued_objects_back();
++
+   GenCompactClosure blk;
+   gch->generation_iterate(&blk, true);
+ 
+   VALIDATE_MARK_SWEEP_ONLY(compaction_complete());
+ 
++  MarkSweep::copy_rescued_objects_back();
++
+   pg->post_compact(); // Shared spaces verification.
+ }
+diff --git a/src/share/vm/memory/permGen.cpp b/src/share/vm/memory/permGen.cpp
+index 350f583..59faad1 100644
+--- a/src/share/vm/memory/permGen.cpp
++++ b/src/share/vm/memory/permGen.cpp
+@@ -57,7 +57,12 @@ HeapWord* PermGen::mem_allocate_in_gen(size_t size, Generation* gen) {
+ 
+   for (;;) {
+     {
+-      MutexLocker ml(Heap_lock);
++      // (tw) Only lock when not at a safepoint (necessary to use the split verifier from the VmThread)
++      Monitor *lock = Heap_lock;
++      if (SafepointSynchronize::is_at_safepoint()) {
++        lock = NULL;
++      }
++      MutexLockerEx ml(lock);
+       if ((obj = gen->allocate(size, false)) != NULL) {
+         return obj;
+       }
+diff --git a/src/share/vm/memory/space.cpp b/src/share/vm/memory/space.cpp
+index f97bc34..9b20d08 100644
+--- a/src/share/vm/memory/space.cpp
++++ b/src/share/vm/memory/space.cpp
+@@ -378,6 +378,31 @@ void CompactibleSpace::clear(bool mangle_space) {
+   _compaction_top = bottom();
+ }
+ 
++// (tw) Calculates the compact_top that will be used for placing the next object with the giving size on the heap.
++HeapWord* CompactibleSpace::forward_compact_top(size_t size,
++CompactPoint* cp, HeapWord* compact_top) {
++  // First check if we should switch compaction space
++  assert(this == cp->space, "'this' should be current compaction space.");
++  size_t compaction_max_size = pointer_delta(end(), compact_top);
++  while (size > compaction_max_size) {
++    // switch to next compaction space
++    cp->space->set_compaction_top(compact_top);
++    cp->space = cp->space->next_compaction_space();
++    if (cp->space == NULL) {
++      cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen);
++      assert(cp->gen != NULL, "compaction must succeed");
++      cp->space = cp->gen->first_compaction_space();
++      assert(cp->space != NULL, "generation must have a first compaction space");
++    }
++    compact_top = cp->space->bottom();
++    cp->space->set_compaction_top(compact_top);
++    cp->threshold = cp->space->initialize_threshold();
++    compaction_max_size = pointer_delta(cp->space->end(), compact_top);
++  }
++
++  return compact_top;
++}
++
+ HeapWord* CompactibleSpace::forward(oop q, size_t size,
+                                     CompactPoint* cp, HeapWord* compact_top) {
+   // q is alive
+@@ -401,7 +426,7 @@ HeapWord* CompactibleSpace::forward(oop q, size_t size,
+   }
+ 
+   // store the forwarding pointer into the mark word
+-  if ((HeapWord*)q != compact_top) {
++  if ((HeapWord*)q != compact_top || (size_t)q->size() != size) {
+     q->forward_to(oop(compact_top));
+     assert(q->is_gc_marked(), "encoding the pointer should preserve the mark");
+   } else {
+@@ -449,7 +474,208 @@ void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) {
+ 
+ // Faster object search.
+ void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) {
+-  SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size);
++  if (!Universe::is_redefining_gc_run()) {
++    SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size);
++    return;
++  }
++
++  /* Compute the new addresses for the live objects and store it in the mark 
++   * Used by universe::mark_sweep_phase2()                                   
++   */                                                                        
++  HeapWord* compact_top; /* This is where we are currently compacting to. */ 
++                                                                             
++  /* We're sure to be here before any objects are compacted into this        
++   * space, so this is a good time to initialize this:                       
++   */                                                                        
++  set_compaction_top(bottom());                                              
++                                                                             
++  if (cp->space == NULL) {                                                   
++    assert(cp->gen != NULL, "need a generation");                            
++    assert(cp->threshold == NULL, "just checking");                          
++    assert(cp->gen->first_compaction_space() == this, "just checking");      
++    cp->space = cp->gen->first_compaction_space();                           
++    compact_top = cp->space->bottom();                                       
++    cp->space->set_compaction_top(compact_top);                              
++    cp->threshold = cp->space->initialize_threshold();                       
++  } else {                                                                  
++    compact_top = cp->space->compaction_top();                               
++  }                                                                          
++                                                                             
++  /* We allow some amount of garbage towards the bottom of the space, so     
++   * we don't start compacting before there is a significant gain to be made.
++   * Occasionally, we want to ensure a full compaction, which is determined  
++   * by the MarkSweepAlwaysCompactCount parameter.                           
++   */                                                                        
++  int invocations = SharedHeap::heap()->perm_gen()->stat_record()->invocations;
++  bool skip_dead = (MarkSweepAlwaysCompactCount < 1)
++    ||((invocations % MarkSweepAlwaysCompactCount) != 0);
++
++  size_t allowed_deadspace = 0;                                              
++  if (skip_dead) {                                                           
++    int ratio = (int)allowed_dead_ratio();                                        
++    allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize;           
++  }                                                                          
++                                                                             
++  HeapWord* q = bottom();                                                    
++  HeapWord* t = end();                                                
++                                                                             
++  HeapWord*  end_of_live= q;    /* One byte beyond the last byte of the last 
++                                   live object. */                           
++  HeapWord*  first_dead = end();/* The first dead object. */                 
++  LiveRange* liveRange  = NULL; /* The current live range, recorded in the   
++                                   first header of preceding free area. */   
++  _first_dead = first_dead;                                                  
++                                                                            
++  const intx interval = PrefetchScanIntervalInBytes;                         
++                                                                             
++  while (q < t) {                                                            
++    assert(!block_is_obj(q) ||                                               
++           oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() ||   
++           oop(q)->mark()->has_bias_pattern(),                               
++           "these are the only valid states during a mark sweep");           
++    if (block_is_obj(q) && oop(q)->is_gc_marked()) {                         
++      /* prefetch beyond q */                                                
++      Prefetch::write(q, interval);                                          
++      /* size_t size = oop(q)->size();  changing this for cms for perm gen */
++      size_t size = block_size(q);     
++
++      // DCEVM: begin
++      //////////////////////////////////////////////////////////////////////////
++      size_t forward_size = size;
++      
++      // Compute the forward sizes and leave out objects whose position could
++      // possibly overlap other objects.
++
++      // DCEVM: There is a new version of the class of q => different size
++      if (oop(q)->blueprint()->new_version() != NULL && oop(q)->blueprint()->new_version()->klass_part()->update_information() != NULL) {
++      
++        size_t new_size = oop(q)->size_given_klass(oop(q)->blueprint()->new_version()->klass_part());
++        assert(size != new_size || oop(q)->is_perm(), "instances without changed size have to be updated prior to GC run");
++        forward_size = new_size;
++      }
++
++      compact_top = cp->space->forward_compact_top(forward_size, cp, compact_top);
++
++      bool rescueing = false;
++      if (rescueing = must_rescue(oop(q), oop(compact_top))) {
++        if (MarkSweep::_rescued_oops == NULL) {
++          MarkSweep::_rescued_oops = new GrowableArray<oop>(128);
++        }
++        // FIXME: idubrov
++        //TRACE_RC5("rescue obj %d klass=%s", MarkSweep::_rescued_oops->length(), oop(q)->klass()->klass_part()->name()->as_C_string());
++        MarkSweep::_rescued_oops->append(oop(q));
++      } else {
++        compact_top = cp->space->forward(oop(q), forward_size, cp, compact_top);
++      }
++      
++      if ((size != forward_size || rescueing) && q < first_dead) {
++        // (tw) This object moves => first_dead must be set to here!
++        first_dead = q;
++      }
++      //////////////////////////////////////////////////////////////////////////
++      q += size;                                                          
++      end_of_live = q;
++    } else {                                                                 
++      /* run over all the contiguous dead objects */                         
++      HeapWord* end = q;                                                     
++      do {                                                                   
++        /* prefetch beyond end */                                            
++        Prefetch::write(end, interval);                                      
++        end += block_size(end);                                              
++      } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));
++                                                                             
++      /* see if we might want to pretend this object is alive so that        
++       * we don't have to compact quite as often.                            
++       */                                                                    
++      if (allowed_deadspace > 0 && q == compact_top) {                       
++        size_t sz = pointer_delta(end, q);                                   
++        if (insert_deadspace(allowed_deadspace, q, sz)) {                    
++          compact_top = cp->space->forward(oop(q), sz, cp, compact_top);     
++          q = end;                                                           
++          end_of_live = end;                                                 
++          continue;                                                          
++        }                                                                    
++      }                                                                      
++                                                                             
++      /* otherwise, it really is a free region. */                           
++                                                                             
++      /* for the previous LiveRange, record the end of the live objects. */  
++      if (liveRange) {                                                       
++        liveRange->set_end(q);                                               
++      }                                                                      
++                                                                             
++      /* record the current LiveRange object.                                
++       * liveRange->start() is overlaid on the mark word.                    
++       */                                                                    
++      liveRange = (LiveRange*)q;                                             
++      liveRange->set_start(end);                                             
++      liveRange->set_end(end);                                               
++                                                                             
++      /* see if this is the first dead region. */                            
++      if (q < first_dead) {                                                  
++        first_dead = q;                                                      
++      }                                                                      
++                                                                             
++      /* move on to the next object */                                       
++      q = end;                                                               
++    }                                                                        
++  }
++
++  //////////////////////////////////////////////////////////////////////////
++  // Compute the forwarding addresses for the objects that need to be
++  // rescued.
++  // TODO: empty the _rescued_oops after ALL spaces are compacted!
++  if (MarkSweep::_rescued_oops != NULL) {
++    // FIXME: idubrov
++    //TRACE_RC2("Calculating new forward sizes for %d objects!", MarkSweep::_rescued_oops->length());
++
++    for (int i=0; i<MarkSweep::_rescued_oops->length(); i++) {
++      oop q = MarkSweep::_rescued_oops->at(i);
++
++      /* size_t size = oop(q)->size();  changing this for cms for perm gen */
++      size_t size = block_size((HeapWord*)q);     
++
++      size_t forward_size = size;
++
++      // (tw) There is a new version of the class of q => different size
++      if (oop(q)->blueprint()->new_version() != NULL) {
++
++        size_t new_size = oop(q)->size_given_klass(oop(q)->blueprint()->new_version()->klass_part());
++        assert(size != new_size || oop(q)->is_perm(), "instances without changed size have to be updated prior to GC run");
++        forward_size = new_size;
++      }
++      
++      compact_top = cp->space->forward(oop(q), forward_size, cp, compact_top);
++      assert(compact_top <= t, "must not write over end of space!");
++    }
++    MarkSweep::_rescued_oops->clear();
++    MarkSweep::_rescued_oops = NULL;
++  }
++  //////////////////////////////////////////////////////////////////////////
++                      
++  assert(q == t, "just checking");                                           
++  if (liveRange != NULL) {                                                   
++    liveRange->set_end(q);                                                   
++  }                                                                         
++  _end_of_live = end_of_live;                                                
++  if (end_of_live < first_dead) {                                            
++    first_dead = end_of_live;                                                
++  }                                                                          
++  _first_dead = first_dead;    
++
++// FIXME: idubrov
++//  if (_first_dead > top()) {
++//    _first_dead = top();
++//  }
++//
++//  if (_end_of_live > top()) {
++//    _end_of_live = top();
++//  }
++  assert(_first_dead <= top(), "Must be smaller equal");
++  assert(_end_of_live <= top(), "Must be smaller equal");
++                                                                             
++  /* save the compaction_top of the compaction space. */                     
++  cp->space->set_compaction_top(compact_top);      
+ }
+ 
+ void Space::adjust_pointers() {
+@@ -490,17 +716,313 @@ void Space::adjust_pointers() {
+   assert(q == t, "just checking");
+ }
+ 
++
++#ifdef ASSERT
++
++int CompactibleSpace::space_index(oop obj) {
++  GenCollectedHeap* heap = GenCollectedHeap::heap();
++
++  if (heap->is_in_permanent(obj)) {
++    return -1;
++  }
++
++  int index = 0;
++  for (int i = heap->n_gens() - 1; i >= 0; i--) {
++    Generation* gen = heap->get_gen(i);
++    CompactibleSpace* space = gen->first_compaction_space();
++    while (space != NULL) {
++      if (space->is_in_reserved(obj)) {
++        return index;
++      }
++      space = space->next_compaction_space();
++      index++;
++    }
++  }
++
++  tty->print_cr("could not compute space_index for %08xh", obj);
++  index = 0;
++  for (int i = heap->n_gens() - 1; i >= 0; i--) {
++    Generation* gen = heap->get_gen(i);
++    tty->print_cr("  generation %s: %08xh - %08xh", gen->name(), gen->reserved().start(), gen->reserved().end());
++
++    CompactibleSpace* space = gen->first_compaction_space();
++    while (space != NULL) {
++      tty->print_cr("    %2d space %08xh - %08xh", index, space->bottom(), space->end());
++      space = space->next_compaction_space();
++      index++;
++    }
++  }
++
++  ShouldNotReachHere();
++  return 0;
++}
++#endif
++
++bool CompactibleSpace::must_rescue(oop old_obj, oop new_obj) {
++
++  assert(is_in_reserved(old_obj), "old_obj must be in this space");
++
++  if (old_obj->is_perm()) {
++    // This object is in perm gen; check for invariant obj->klass() <= obj
++    if (oop(old_obj)->blueprint()->new_version() != NULL) {
++      return true;
++    }
++  }
++
++  int size = old_obj->size();
++  int original_size = size;
++  if (oop(old_obj)->blueprint()->is_redefining()) {
++    assert(oop(old_obj)->blueprint()->old_version() != NULL, "must not be null");
++    original_size = oop(old_obj)->size_given_klass(oop(old_obj)->blueprint()->old_version()->klass_part());
++  } else if (oop(old_obj)->blueprint()->new_version() != NULL) {
++    size = oop(old_obj)->size_given_klass(oop(old_obj)->blueprint()->new_version()->klass_part());
++  }
++
++  bool normalComparison = (old_obj + original_size < new_obj + size);
++
++  if (is_in_reserved(new_obj)) {
++    // Old and new address are in same space, so just compare the address.
++    // Must rescue if object moves towards the top of the space.
++    assert(space_index(old_obj) == space_index(new_obj), "old_obj and new_obj must be in same space");
++    return normalComparison;
++
++  } else {
++
++    assert(space_index(old_obj) != space_index(new_obj), "old_obj and new_obj must be in different spaces");
++
++    Generation* tenured_gen = GenCollectedHeap::heap()->get_gen(1);
++    if (tenured_gen->is_in_reserved(new_obj)) {
++      // Must never rescue when moving from the new into the old generation.
++      assert(GenCollectedHeap::heap()->get_gen(0)->is_in_reserved(old_obj), "old_obj must be in DefNewGeneration");
++      assert(space_index(old_obj) > space_index(new_obj), "must be");
++      return false;
++
++    } else if (tenured_gen->is_in_reserved(old_obj)) {
++      // Must always rescue when moving from the old into the new generation.
++      assert(GenCollectedHeap::heap()->get_gen(0)->is_in_reserved(new_obj), "new_obj must be in DefNewGeneration");
++      assert(space_index(old_obj) < space_index(new_obj), "must be");
++      return true;
++
++    } else {
++      // In the new generation, eden is located before the from space, so a
++      // simple pointer comparison is sufficient.
++      assert(GenCollectedHeap::heap()->get_gen(0)->is_in_reserved(old_obj), "old_obj must be in DefNewGeneration");
++      assert(GenCollectedHeap::heap()->get_gen(0)->is_in_reserved(new_obj), "new_obj must be in DefNewGeneration");
++      assert((normalComparison) == (space_index(old_obj) < space_index(new_obj)), "slow and fast computation must yield same result");
++      return normalComparison;
++    }
++  }
++}
++
++oop CompactibleSpace::rescue(oop old_obj) {
++  assert(must_rescue(old_obj, old_obj->forwardee()), "do not call otherwise");
++
++  int size = old_obj->size();
++  oop rescued_obj = (oop)resource_allocate_bytes(size * HeapWordSize);
++  Copy::aligned_disjoint_words((HeapWord*)old_obj, (HeapWord*)rescued_obj, size);
++
++  if (MarkSweep::_rescued_oops == NULL) {
++    MarkSweep::_rescued_oops = new GrowableArray<oop>(128);
++  }
++
++  MarkSweep::_rescued_oops->append(rescued_obj);
++  return rescued_obj;
++}
++
+ void CompactibleSpace::adjust_pointers() {
+   // Check first is there is any work to do.
+   if (used() == 0) {
+     return;   // Nothing to do.
+   }
+-
+-  SCAN_AND_ADJUST_POINTERS(adjust_obj_size);
++  /* adjust all the interior pointers to point at the new locations of objects        
++  * Used by MarkSweep::mark_sweep_phase3() */                                        
++
++  HeapWord* q = bottom();                                                        
++  HeapWord* t = _end_of_live;  /* Established by "prepare_for_compaction". */        
++
++  assert(_first_dead <= _end_of_live, "Stands to reason, no?");                        
++
++  debug_only(HeapWord* prev_q = NULL);   
++  debug_only(HeapWord* prev_prev_q = NULL); 
++  debug_only(HeapWord* prev_prev_prev_q = NULL);   
++  if (q < t && _first_dead > q &&                                                
++    !oop(q)->is_gc_marked()) {                                                
++      /* we have a chunk of the space which hasn't moved and we've                
++      * reinitialized the mark word during the previous pass, so we can't        
++      * use is_gc_marked for the traversal. */                                        
++      HeapWord* end = _first_dead;                                                
++      
++        while (q < end) {                                                                
++          /* I originally tried to conjoin "block_start(q) == q" to the                
++          * assertion below, but that doesn't work, because you can't                
++          * accurately traverse previous objects to get to the current one                
++          * after their pointers (including pointers into permGen) have been        
++          * updated, until the actual compaction is done.  dld, 4/00 */                
++          assert(block_is_obj(q),                                                        
++            "should be at block boundaries, and should be looking at objs");        
++
++          VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q)));     
++
++          /* point all the oops to the new location */     
++          size_t size = oop(q)->adjust_pointers();        
++          size = adjust_obj_size(size);        
++
++          VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers());           
++          VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size));     
++
++          debug_only(prev_prev_prev_q = prev_prev_q);  
++          debug_only(prev_prev_q = prev_q);  
++          debug_only(prev_q = q);  
++          q += size;                                                                
++        }                                                                                
++
++        // (tw) first_dead can be live object!
++        q = _first_dead;
++
++//        if (_first_dead == t) {                                                        
++//          q = t;                                                                        
++//        } else {                                                                        
++//          /* $$$ This is funky.  Using this to read the previously written                
++//          * LiveRange.  See also use below. */                                        
++//          q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer();                
++//        }                                                                               
++  }                                                                                
++
++  const intx interval = PrefetchScanIntervalInBytes;                            
++
++  debug_only(prev_q = NULL);  
++  debug_only(prev_prev_q = NULL); 
++  debug_only(prev_prev_prev_q = NULL);                                                 
++  while (q < t) {                                                                
++    /* prefetch beyond q */                                                        
++    Prefetch::write(q, interval);                                               
++    if (oop(q)->is_gc_marked()) {                                                
++      /* q is alive */                                                                
++      VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q)));     
++      /* point all the oops to the new location */                                
++      size_t size = oop(q)->adjust_pointers();      
++      size = adjust_obj_size(size);                                                
++      VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers());                
++      VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size));     
++      debug_only(prev_prev_prev_q = prev_prev_q);  
++      debug_only(prev_prev_q = prev_q);  
++      debug_only(prev_q = q);                                                        
++      q += size;                                                                
++    } else {                                                                        
++      /* q is not a live object, so its mark should point at the next                
++      * live object */                              
++      debug_only(prev_prev_prev_q = prev_prev_q);  
++      debug_only(prev_prev_q = prev_q);                                    
++      debug_only(prev_q = q);                                                        
++      q = (HeapWord*) oop(q)->mark()->decode_pointer();                                
++      assert(q > prev_q, "we should be moving forward through memory");                
++    }                                                                                
++  }                                                                                
++
++  assert(q == t, "just checking");     
+ }
+ 
+ void CompactibleSpace::compact() {
+-  SCAN_AND_COMPACT(obj_size);
++
++  if(!Universe::is_redefining_gc_run()) {
++    SCAN_AND_COMPACT(obj_size);
++    return;
++  } 
++
++  /* Copy all live objects to their new location
++   * Used by MarkSweep::mark_sweep_phase4() */
++  
++  HeapWord*       q = bottom();
++  HeapWord* const t = _end_of_live; 
++  debug_only(HeapWord* prev_q = NULL);    
++  
++  if (q < t && _first_dead > q &&                                                
++      !oop(q)->is_gc_marked()) {
++    debug_only(
++    /* we have a chunk of the space which hasn't moved and we've reinitialized  
++     * the mark word during the previous pass, so we can't use is_gc_marked for 
++     * the traversal. */                                                        
++    HeapWord* const end = _first_dead;                                                
++
++    while (q < end) {
++      size_t size = obj_size(q); // FIXME: idubrov oop(q)->size();
++      assert(!oop(q)->is_gc_marked(),                                           
++             "should be unmarked (special dense prefix handling)");             
++      VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, q));     
++      debug_only(prev_q = q);                                                        
++      q += size;                                                                
++    }  
++    )  /* debug_only */
++    // (tw) first_dead can be live object!
++    q = _first_dead;
++
++    //if (_first_dead == t) {                                                        
++    //  q = t;                                                                        
++    //} else {                                                                        
++    ///* $$$ Funky */                                                                 
++    //q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer();                
++    //}                                                                                
++  }                                                                                
++  
++  const intx scan_interval = PrefetchScanIntervalInBytes;                        
++  const intx copy_interval = PrefetchCopyIntervalInBytes;                        
++  while (q < t) {                                                                
++    if (!oop(q)->is_gc_marked()) {                                                
++      /* mark is pointer to next marked oop */     
++      debug_only(prev_q = q);                                                        
++      q = (HeapWord*) oop(q)->mark()->decode_pointer();                                
++      assert(q > prev_q, "we should be moving forward through memory");                
++    } else {                                                                        
++      /* prefetch beyond q */                                                        
++      Prefetch::read(q, scan_interval);
++   
++      /* size and destination */                                                
++      size_t size = obj_size(q);                                                
++      HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); 
++
++      if (must_rescue(oop(q), oop(q)->forwardee())) {
++        oop dest_obj = rescue(oop(q));
++        debug_only(Copy::fill_to_words(q, size, 0));
++      } else {
++
++        /* prefetch beyond compaction_top */                                        
++        Prefetch::write(compaction_top, copy_interval);                           
++        
++        /* copy object and reinit its mark */                                        
++        VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size,            
++                                                              compaction_top));   
++        assert(q != compaction_top || oop(q)->blueprint()->new_version() != NULL, "everything in this pass should be moving");        
++        
++        if (oop(q)->blueprint()->new_version() != NULL) {
++          MarkSweep::update_fields(oop(q), oop(compaction_top));
++        } else {
++          Copy::aligned_conjoint_words(q, compaction_top, size);
++        }
++        oop(compaction_top)->init_mark();                                                
++        assert(oop(compaction_top)->klass() != NULL, "should have a class");
++      }
++
++      debug_only(prev_q = q);               
++      q += size;                                                                
++    }                                                                                
++  }                        
++  
++  /* Let's remember if we were empty before we did the compaction. */
++  bool was_empty = used_region().is_empty();
++  /* Reset space after compaction is complete */
++  reset_after_compaction();
++  /* We do this clear, below, since it has overloaded meanings for some */
++  /* space subtypes.  For example, OffsetTableContigSpace's that were   */
++  /* compacted into will have had their offset table thresholds updated */
++  /* continuously, but those that weren't need to have their thresholds */
++  /* re-initialized.  Also mangles unused area for debugging.           */
++  if (used_region().is_empty()) {
++    if (!was_empty) clear(SpaceDecorator::Mangle);
++  } else {
++    if (ZapUnusedHeapArea) mangle_unused_area();
++  }
++
++  //SCAN_AND_COMPACT(obj_size);
+ }
+ 
+ void Space::print_short() const { print_short_on(tty); }
+diff --git a/src/share/vm/memory/space.hpp b/src/share/vm/memory/space.hpp
+index ef2f2c6..b54d470 100644
+--- a/src/share/vm/memory/space.hpp
++++ b/src/share/vm/memory/space.hpp
+@@ -445,6 +445,9 @@ public:
+   // indicates when the next such action should be taken.
+   virtual void prepare_for_compaction(CompactPoint* cp);
+   // MarkSweep support phase3
++  DEBUG_ONLY(int space_index(oop obj));
++  bool must_rescue(oop old_obj, oop new_obj);
++  oop rescue(oop old_obj);
+   virtual void adjust_pointers();
+   // MarkSweep support phase4
+   virtual void compact();
+@@ -475,6 +478,10 @@ public:
+   virtual HeapWord* forward(oop q, size_t size, CompactPoint* cp,
+                     HeapWord* compact_top);
+ 
++  // (tw)
++  virtual HeapWord* forward_compact_top(size_t size, CompactPoint* cp,
++    HeapWord* compact_top);
++
+   // Return a size with adjusments as required of the space.
+   virtual size_t adjust_object_size_v(size_t size) const { return size; }
+ 
+diff --git a/src/share/vm/memory/universe.cpp b/src/share/vm/memory/universe.cpp
+index 4030d9d..da9a186 100644
+--- a/src/share/vm/memory/universe.cpp
++++ b/src/share/vm/memory/universe.cpp
+@@ -100,6 +100,8 @@
+ #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
+ #endif
+ 
++bool Universe::_is_redefining_gc_run = false;
++
+ // Known objects
+ klassOop Universe::_boolArrayKlassObj                 = NULL;
+ klassOop Universe::_byteArrayKlassObj                 = NULL;
+@@ -204,6 +206,38 @@ void Universe::system_classes_do(void f(klassOop)) {
+   f(systemObjArrayKlassObj());
+ }
+ 
++// DCEVM: This method should iterate all pointers that are not within heap objects.
++void Universe::root_oops_do(OopClosure *oopClosure) {
++
++  class AlwaysTrueClosure: public BoolObjectClosure {
++  public:
++    void do_object(oop p) { ShouldNotReachHere(); }
++    bool do_object_b(oop p) { return true; }
++  };
++  AlwaysTrueClosure always_true;
++
++  // General strong roots
++  Universe::oops_do(oopClosure);
++  JNIHandles::oops_do(oopClosure);
++  Threads::oops_do(oopClosure, NULL);
++  ObjectSynchronizer::oops_do(oopClosure);
++  FlatProfiler::oops_do(oopClosure);
++  //Management::oops_do(oopClosure); // DCEVM: TODO: Check if this is correct?
++  JvmtiExport::oops_do(oopClosure);
++  // SO_AllClasses
++  SystemDictionary::oops_do(oopClosure);
++  
++  // Now adjust pointers in remaining weak roots.  (All of which should
++  // have been cleared if they pointed to non-surviving objects.)
++  // Global (weak) JNI handles
++  JNIHandles::weak_oops_do(&always_true, oopClosure);
++  
++  CodeCache::oops_do(oopClosure);
++  StringTable::oops_do(oopClosure);
++  //ref_processor()->weak_oops_do(&oopClosure); // DCEVM: TODO: Check if this is correct?
++  //PSScavenge::reference_processor()->weak_oops_do(&oopClosure); // DCEVM: TODO: Check if this is correct?
++}
++
+ void Universe::oops_do(OopClosure* f, bool do_all) {
+ 
+   f->do_oop((oop*) &_int_mirror);
+diff --git a/src/share/vm/memory/universe.hpp b/src/share/vm/memory/universe.hpp
+index 50fcb62..afb6b33 100644
+--- a/src/share/vm/memory/universe.hpp
++++ b/src/share/vm/memory/universe.hpp
+@@ -127,6 +127,8 @@ class Universe: AllStatic {
+   friend class SystemDictionary;
+   friend class VMStructs;
+   friend class CompactingPermGenGen;
++  friend class Space;
++  friend class ContiguousSpace;
+   friend class VM_PopulateDumpSharedSpace;
+ 
+   friend jint  universe_init();
+@@ -258,7 +260,18 @@ class Universe: AllStatic {
+ 
+   static void compute_verify_oop_data();
+ 
++  static bool _is_redefining_gc_run;
++
+  public:
++
++   static bool is_redefining_gc_run() {
++     return _is_redefining_gc_run;
++   }
++
++   static void set_redefining_gc_run(bool b) {
++     _is_redefining_gc_run = b;
++   }
++
+   // Known classes in the VM
+   static klassOop boolArrayKlassObj()                 { return _boolArrayKlassObj;   }
+   static klassOop byteArrayKlassObj()                 { return _byteArrayKlassObj;   }
+@@ -403,6 +416,8 @@ class Universe: AllStatic {
+ 
+   // Iteration
+ 
++  static void root_oops_do(OopClosure *f);
++
+   // Apply "f" to the addresses of all the direct heap pointers maintained
+   // as static fields of "Universe".
+   static void oops_do(OopClosure* f, bool do_all = false);
+@@ -419,6 +434,7 @@ class Universe: AllStatic {
+ 
+   // Debugging
+   static bool verify_in_progress() { return _verify_in_progress; }
++  static void set_verify_in_progress(bool b) { _verify_in_progress = b; }
+   static void verify(VerifyOption option, const char* prefix, bool silent = VerifySilently);
+   static void verify(const char* prefix, bool silent = VerifySilently) {
+     verify(VerifyOption_Default, prefix, silent);
+diff --git a/src/share/vm/oops/arrayKlass.cpp b/src/share/vm/oops/arrayKlass.cpp
+index 16142b8..921e546 100644
+--- a/src/share/vm/oops/arrayKlass.cpp
++++ b/src/share/vm/oops/arrayKlass.cpp
+@@ -136,9 +136,9 @@ objArrayOop arrayKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
+ 
+ bool arrayKlass::compute_is_subtype_of(klassOop k) {
+   // An array is a subtype of Serializable, Clonable, and Object
+-  return    k == SystemDictionary::Object_klass()
+-         || k == SystemDictionary::Cloneable_klass()
+-         || k == SystemDictionary::Serializable_klass();
++  return    k->klass_part()->newest_version() == SystemDictionary::Object_klass()->klass_part()->newest_version()
++         || k->klass_part()->newest_version() == SystemDictionary::Cloneable_klass()->klass_part()->newest_version()
++         || k->klass_part()->newest_version() == SystemDictionary::Serializable_klass()->klass_part()->newest_version();
+ }
+ 
+ 
+diff --git a/src/share/vm/oops/constMethodKlass.cpp b/src/share/vm/oops/constMethodKlass.cpp
+index e74811f..be3fe7d 100644
+--- a/src/share/vm/oops/constMethodKlass.cpp
++++ b/src/share/vm/oops/constMethodKlass.cpp
+@@ -102,6 +102,7 @@ void constMethodKlass::oop_follow_contents(oop obj) {
+   constMethodOop cm = constMethodOop(obj);
+   MarkSweep::mark_and_push(cm->adr_constants());
+   MarkSweep::mark_and_push(cm->adr_stackmap_data());
++  MarkSweep::mark_and_push(cm->adr_code_section_table());
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::constMethodKlassObj never moves.
+ }
+@@ -113,6 +114,7 @@ void constMethodKlass::oop_follow_contents(ParCompactionManager* cm,
+   constMethodOop cm_oop = constMethodOop(obj);
+   PSParallelCompact::mark_and_push(cm, cm_oop->adr_constants());
+   PSParallelCompact::mark_and_push(cm, cm_oop->adr_stackmap_data());
++  PSParallelCompact::mark_and_push(cm, cm_oop->adr_code_section_table());
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::constMethodKlassObj never moves.
+ }
+@@ -123,6 +125,7 @@ int constMethodKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
+   constMethodOop cm = constMethodOop(obj);
+   blk->do_oop(cm->adr_constants());
+   blk->do_oop(cm->adr_stackmap_data());
++  blk->do_oop(cm->adr_code_section_table());
+   // Get size before changing pointers.
+   // Don't call size() or oop_size() since that is a virtual call.
+   int size = cm->object_size();
+@@ -138,6 +141,8 @@ int constMethodKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr)
+   if (mr.contains(adr)) blk->do_oop(adr);
+   adr = cm->adr_stackmap_data();
+   if (mr.contains(adr)) blk->do_oop(adr);
++  adr = cm->adr_code_section_table();
++  if (mr.contains(adr)) blk->do_oop(adr);
+   // Get size before changing pointers.
+   // Don't call size() or oop_size() since that is a virtual call.
+   int size = cm->object_size();
+@@ -152,6 +157,7 @@ int constMethodKlass::oop_adjust_pointers(oop obj) {
+   constMethodOop cm = constMethodOop(obj);
+   MarkSweep::adjust_pointer(cm->adr_constants());
+   MarkSweep::adjust_pointer(cm->adr_stackmap_data());
++  MarkSweep::adjust_pointer(cm->adr_code_section_table());
+   // Get size before changing pointers.
+   // Don't call size() or oop_size() since that is a virtual call.
+   int size = cm->object_size();
+diff --git a/src/share/vm/oops/constMethodOop.hpp b/src/share/vm/oops/constMethodOop.hpp
+index 549192b..5cea5c4 100644
+--- a/src/share/vm/oops/constMethodOop.hpp
++++ b/src/share/vm/oops/constMethodOop.hpp
+@@ -129,7 +129,7 @@ private:
+ 
+ public:
+   oop* oop_block_beg() const { return adr_constants(); }
+-  oop* oop_block_end() const { return adr_stackmap_data() + 1; }
++  oop* oop_block_end() const { return adr_code_section_table() + 1; }
+ 
+ private:
+   //
+@@ -141,6 +141,9 @@ private:
+   // Raw stackmap data for the method
+   typeArrayOop      _stackmap_data;
+ 
++  // (tw) Table mapping code sections for method forward points.
++  typeArrayOop      _code_section_table;
++
+   //
+   // End of the oop block.
+   //
+@@ -195,6 +198,28 @@ public:
+   }
+   bool has_stackmap_table() const { return _stackmap_data != NULL; }
+ 
++  // code section table
++  typeArrayOop code_section_table() const         { return _code_section_table; }
++  void set_code_section_table(typeArrayOop e)     { oop_store_without_check((oop*) &_code_section_table, (oop) e); }
++  bool has_code_section_table() const             { return code_section_table() != NULL && code_section_table()->length() > 0; }
++  static const int ValuesPerCodeSectionEntry = 3;
++  int code_section_entries() const {
++    if (!has_code_section_table()) return 0;
++    return _code_section_table->length() / ValuesPerCodeSectionEntry;
++  }
++
++  int code_section_new_index_at(int index) const {
++    return _code_section_table->short_at(index * ValuesPerCodeSectionEntry);
++  }
++
++  int code_section_original_index_at(int index) const {
++    return _code_section_table->short_at(index * ValuesPerCodeSectionEntry + 1);
++  }
++
++  int code_section_length_at(int index) const {
++    return _code_section_table->short_at(index * ValuesPerCodeSectionEntry + 2);
++  }
++
+   void init_fingerprint() {
+     const uint64_t initval = CONST64(0x8000000000000000);
+     _fingerprint = initval;
+@@ -301,6 +326,7 @@ public:
+   // Garbage collection support
+   oop*  adr_constants() const          { return (oop*)&_constants; }
+   oop*  adr_stackmap_data() const      { return (oop*)&_stackmap_data;   }
++  oop*  adr_code_section_table() const { return (oop*)&_code_section_table; }
+   bool is_conc_safe() { return _is_conc_safe; }
+   void set_is_conc_safe(bool v) { _is_conc_safe = v; }
+ 
+diff --git a/src/share/vm/oops/cpCacheOop.cpp b/src/share/vm/oops/cpCacheOop.cpp
+index ad62921..f39f202 100644
+--- a/src/share/vm/oops/cpCacheOop.cpp
++++ b/src/share/vm/oops/cpCacheOop.cpp
+@@ -37,9 +37,15 @@
+ 
+ // Implememtation of ConstantPoolCacheEntry
+ 
++void ConstantPoolCacheEntry::copy_from(ConstantPoolCacheEntry *other) {
++  _flags = other->_flags;    // flags
++}
++
+ void ConstantPoolCacheEntry::initialize_entry(int index) {
+   assert(0 < index && index < 0x10000, "sanity check");
+   _indices = index;
++  _f1 = NULL;
++  _f2 = 0;
+   assert(constant_pool_index() == index, "");
+ }
+ 
+@@ -162,7 +168,8 @@ void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
+                                         int vtable_index) {
+   assert(!is_secondary_entry(), "");
+   assert(method->interpreter_entry() != NULL, "should have been set at this point");
+-  assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
++  // (tw) No longer valid assert
++  //assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
+ 
+   int byte_no = -1;
+   bool change_to_virtual = false;
+@@ -183,6 +190,7 @@ void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
+           set_method_flags(as_TosState(method->result_type()),
+                            (                             1      << is_vfinal_shift) |
+                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |
++                           ((method->is_old()          ? 1 : 0) << is_old_method_shift) |
+                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),
+                            method()->size_of_parameters());
+           set_f2_as_vfinal_method(method());
+@@ -190,9 +198,13 @@ void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
+           assert(vtable_index >= 0, "valid index");
+           assert(!method->is_final_method(), "sanity");
+           set_method_flags(as_TosState(method->result_type()),
++                           ((method->is_old()          ? 1 : 0) << is_old_method_shift) |
+                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
+                            method()->size_of_parameters());
+           set_f2(vtable_index);
++
++          // (tw) save method holder in f1 for virtual calls
++          set_f1(method());
+         }
+         byte_no = 2;
+         break;
+@@ -206,7 +218,8 @@ void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
+       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
+       set_method_flags(as_TosState(method->result_type()),
+                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |
+-                       ((method->is_final_method() ? 1 : 0) << is_final_shift),
++                       ((method->is_final_method() ? 1 : 0) << is_final_shift) |
++                       ((method->is_old()          ? 1 : 0) << is_old_method_shift),
+                        method()->size_of_parameters());
+       set_f1(method());
+       byte_no = 1;
+@@ -259,7 +272,7 @@ void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index)
+   set_f1(interf);
+   set_f2(index);
+   set_method_flags(as_TosState(method->result_type()),
+-                   0,  // no option bits
++                   ((method->is_old()          ? 1 : 0) << is_old_method_shift),
+                    method()->size_of_parameters());
+   set_bytecode_1(Bytecodes::_invokeinterface);
+ }
+@@ -520,27 +533,12 @@ void ConstantPoolCacheEntry::update_pointers() {
+ // If this constantPoolCacheEntry refers to old_method then update it
+ // to refer to new_method.
+ bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
+-       methodOop new_method, bool * trace_name_printed) {
++       methodOop new_method) {
+ 
+   if (is_vfinal()) {
+-    // virtual and final so _f2 contains method ptr instead of vtable index
+-    if (f2_as_vfinal_method() == old_method) {
+-      // match old_method so need an update
+-      // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
+-      _f2 = (intptr_t)new_method;
+-      if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
+-        if (!(*trace_name_printed)) {
+-          // RC_TRACE_MESG macro has an embedded ResourceMark
+-          RC_TRACE_MESG(("adjust: name=%s",
+-            Klass::cast(old_method->method_holder())->external_name()));
+-          *trace_name_printed = true;
+-        }
+-        // RC_TRACE macro has an embedded ResourceMark
+-        RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
+-          new_method->name()->as_C_string(),
+-          new_method->signature()->as_C_string()));
+-      }
+-
++    // virtual and final so f2() contains method ptr instead of vtable index
++    if (f2_as_vfinal_method() != NULL && f2_as_vfinal_method()->method_holder()->klass_part()->new_version()) {
++      initialize_entry(constant_pool_index());
+       return true;
+     }
+ 
+@@ -548,84 +546,27 @@ bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
+     return false;
+   }
+ 
+-  if ((oop)_f1 == NULL) {
+-    // NULL f1() means this is a virtual entry so bail out
+-    // We are assuming that the vtable index does not need change.
++  // (tw) check how to update interface methods!
++  if (bytecode_1() == Bytecodes::_invokevirtual || bytecode_2() == Bytecodes::_invokevirtual) {
++      
++    if(f1_as_method()->method_holder()->klass_part()->new_version()) {
++      initialize_entry(constant_pool_index());
++      return true;
++    }
++
+     return false;
+   }
+ 
+   if ((oop)_f1 == old_method) {
+     _f1 = new_method;
+-    if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
+-      if (!(*trace_name_printed)) {
+-        // RC_TRACE_MESG macro has an embedded ResourceMark
+-        RC_TRACE_MESG(("adjust: name=%s",
+-          Klass::cast(old_method->method_holder())->external_name()));
+-        *trace_name_printed = true;
+-      }
+-      // RC_TRACE macro has an embedded ResourceMark
+-      RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
+-        new_method->name()->as_C_string(),
+-        new_method->signature()->as_C_string()));
+-    }
+-
+     return true;
++  } else if(_f1 != NULL && (bytecode_1() != Bytecodes::_invokeinterface && f1_as_method()->method_holder()->klass_part()->new_version())) {
++    initialize_entry(constant_pool_index());
+   }
+ 
+   return false;
+ }
+ 
+-// a constant pool cache entry should never contain old or obsolete methods
+-bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
+-  if (is_vfinal()) {
+-    // virtual and final so _f2 contains method ptr instead of vtable index
+-    methodOop m = (methodOop)_f2;
+-    // Return false if _f2 refers to an old or an obsolete method.
+-    // _f2 == NULL || !m->is_method() are just as unexpected here.
+-    return (m != NULL && m->is_method() && !m->is_old() && !m->is_obsolete());
+-  } else if ((oop)_f1 == NULL || !((oop)_f1)->is_method()) {
+-    // _f1 == NULL || !_f1->is_method() are OK here
+-    return true;
+-  }
+-
+-  methodOop m = (methodOop)_f1;
+-  // return false if _f1 refers to an old or an obsolete method
+-  return (!m->is_old() && !m->is_obsolete());
+-}
+-
+-bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {
+-  if (!is_method_entry()) {
+-    // not a method entry so not interesting by default
+-    return false;
+-  }
+-
+-  methodOop m = NULL;
+-  if (is_vfinal()) {
+-    // virtual and final so _f2 contains method ptr instead of vtable index
+-    m = f2_as_vfinal_method();
+-  } else if (is_f1_null()) {
+-    // NULL _f1 means this is a virtual entry so also not interesting
+-    return false;
+-  } else {
+-    oop f1 = _f1;  // _f1 is volatile
+-    if (!f1->is_method()) {
+-      // _f1 can also contain a klassOop for an interface
+-      return false;
+-    }
+-    m = f1_as_method();
+-  }
+-
+-  assert(m != NULL && m->is_method(), "sanity check");
+-  if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
+-    // robustness for above sanity checks or method is not in
+-    // the interesting class
+-    return false;
+-  }
+-
+-  // the method is in the interesting class so the entry is interesting
+-  return true;
+-}
+-
+ void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
+   // print separator
+   if (index == 0) st->print_cr("                 -------------");
+@@ -663,60 +604,18 @@ void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {
+   }
+ }
+ 
+-// RedefineClasses() API support:
+-// If any entry of this constantPoolCache points to any of
+-// old_methods, replace it with the corresponding new_method.
+-void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+-                                                     int methods_length, bool * trace_name_printed) {
+-
+-  if (methods_length == 0) {
+-    // nothing to do if there are no methods
+-    return;
+-  }
+-
+-  // get shorthand for the interesting class
+-  klassOop old_holder = old_methods[0]->method_holder();
++void constantPoolCacheOopDesc::adjust_entries(methodOop* old_methods, methodOop* new_methods,
++                                                     int methods_length) {
+ 
+   for (int i = 0; i < length(); i++) {
+-    if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
+-      // skip uninteresting methods
+-      continue;
+-    }
+-
+-    // The constantPoolCache contains entries for several different
+-    // things, but we only care about methods. In fact, we only care
+-    // about methods in the same class as the one that contains the
+-    // old_methods. At this point, we have an interesting entry.
+-
+-    for (int j = 0; j < methods_length; j++) {
+-      methodOop old_method = old_methods[j];
+-      methodOop new_method = new_methods[j];
+-
+-      if (entry_at(i)->adjust_method_entry(old_method, new_method,
+-          trace_name_printed)) {
+-        // current old_method matched this entry and we updated it so
+-        // break out and get to the next interesting entry if there one
+-        break;
+-      }
++    if (entry_at(i)->is_field_entry()) {
++      // (tw) TODO: Update only field offsets and modify only constant pool entries that
++      // point to changed fields
++      entry_at(i)->initialize_entry(entry_at(i)->constant_pool_index());     
++    } else if(entry_at(i)->is_method_entry()) {
++      entry_at(i)->adjust_method_entry(NULL, NULL);
+     }
+   }
+ }
+ 
+-// the constant pool cache should never contain old or obsolete methods
+-bool constantPoolCacheOopDesc::check_no_old_or_obsolete_entries() {
+-  for (int i = 1; i < length(); i++) {
+-    if (entry_at(i)->is_interesting_method_entry(NULL) &&
+-        !entry_at(i)->check_no_old_or_obsolete_entries()) {
+-      return false;
+-    }
+-  }
+-  return true;
+-}
+ 
+-void constantPoolCacheOopDesc::dump_cache() {
+-  for (int i = 1; i < length(); i++) {
+-    if (entry_at(i)->is_interesting_method_entry(NULL)) {
+-      entry_at(i)->print(tty, i);
+-    }
+-  }
+-}
+diff --git a/src/share/vm/oops/cpCacheOop.hpp b/src/share/vm/oops/cpCacheOop.hpp
+index ef26775..6f37d81 100644
+--- a/src/share/vm/oops/cpCacheOop.hpp
++++ b/src/share/vm/oops/cpCacheOop.hpp
+@@ -136,7 +136,8 @@ class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
+   void set_bytecode_2(Bytecodes::Code code);
+   void set_f1(oop f1)                            {
+     oop existing_f1 = _f1; // read once
+-    assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
++    // (tw) need to relax assertion for redefinition
++    // assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
+     oop_store(&_f1, f1);
+   }
+   void release_set_f1(oop f1);
+@@ -167,6 +168,7 @@ class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
+     tos_state_mask             = right_n_bits(tos_state_bits),
+     tos_state_shift            = BitsPerInt - tos_state_bits,  // see verify_tos_state_shift below
+     // misc. option bits; can be any bit position in [16..27]
++    is_old_method_shift        = 19,
+     is_vfinal_shift            = 20,
+     is_volatile_shift          = 21,
+     is_final_shift             = 22,
+@@ -200,6 +202,8 @@ class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
+   void initialize_entry(int original_index);     // initialize primary entry
+   void initialize_secondary_entry(int main_index); // initialize secondary entry
+ 
++  void copy_from(ConstantPoolCacheEntry *other);
++
+   void set_field(                                // sets entry to resolved field state
+     Bytecodes::Code get_code,                    // the bytecode used for reading the field
+     Bytecodes::Code put_code,                    // the bytecode used for writing the field
+@@ -361,10 +365,7 @@ class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
+   // trace_name_printed is set to true if the current call has
+   // printed the klass name so that other routines in the adjust_*
+   // group don't print the klass name.
+-  bool adjust_method_entry(methodOop old_method, methodOop new_method,
+-         bool * trace_name_printed);
+-  bool check_no_old_or_obsolete_entries();
+-  bool is_interesting_method_entry(klassOop k);
++  bool adjust_method_entry(methodOop old_method, methodOop new_method);
+ 
+   // Debugging & Printing
+   void print (outputStream* st, int index) const;
+@@ -485,16 +486,9 @@ class constantPoolCacheOopDesc: public oopDesc {
+     return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
+   }
+ 
+-  // RedefineClasses() API support:
+-  // If any entry of this constantPoolCache points to any of
+-  // old_methods, replace it with the corresponding new_method.
+-  // trace_name_printed is set to true if the current call has
+-  // printed the klass name so that other routines in the adjust_*
+-  // group don't print the klass name.
+-  void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+-                             int methods_length, bool * trace_name_printed);
+-  bool check_no_old_or_obsolete_entries();
+-  void dump_cache();
++  // (tw) Update method and field references
++  void adjust_entries(methodOop* old_methods, methodOop* new_methods,
++                             int methods_length);
+ };
+ 
+ #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP
+diff --git a/src/share/vm/oops/instanceKlass.cpp b/src/share/vm/oops/instanceKlass.cpp
+index a775b02..749458f 100644
+--- a/src/share/vm/oops/instanceKlass.cpp
++++ b/src/share/vm/oops/instanceKlass.cpp
+@@ -250,12 +250,118 @@ void instanceKlass::initialize(TRAPS) {
+ }
+ 
+ 
++void instanceKlass::initialize_redefined_class() {
++  RC_TRACE(0x00000400, ("initializing redefined class %s",
++    name()->as_C_string()));
++  
++  assert(!is_initialized(), "");
++  assert(this->old_version() != NULL, "");
++  assert(is_linked(), "must be linked before");
++
++
++  instanceKlassHandle this_oop(Thread::current(), this->as_klassOop());
++  class UpdateStaticFieldClosure : public FieldClosure {
++
++  private:
++    instanceKlassHandle this_oop;
++
++  public:
++    UpdateStaticFieldClosure(instanceKlassHandle this_oop) {
++      this->this_oop = this_oop;
++    }
++
++    virtual void do_field(fieldDescriptor* fd) {
++      fieldDescriptor result;
++      bool found = ((instanceKlass *)(this_oop->old_version()->klass_part()))->find_local_field(fd->name(), fd->signature(), &result);
++    
++      if (found && result.is_static()) {
++        int old_offset = result.offset();
++        assert(result.field_type() == fd->field_type(), "Old and new field type does not match");
++
++        oop new_location = this_oop()->java_mirror();
++        oop old_location = this_oop->old_version()->java_mirror();
++        int offset = fd->offset();
++        RC_TRACE(0x00000400, ("Copying static field value for field '%s' old_offset=%d new_offset=%d",
++          fd->name()->as_C_string(), old_offset, offset));
++
++        oop cur_oop;
++
++        switch(result.field_type()) {
++
++          // Found static field with same name and type in the old klass => copy value from old to new klass
++        
++          case T_BOOLEAN:
++            new_location->bool_field_put(offset, old_location->bool_field(old_offset));
++            DEBUG_ONLY(old_location->byte_field_put(old_offset, 0));
++            break;
++
++          case T_CHAR:
++            new_location->char_field_put(offset, old_location->char_field(old_offset));
++            DEBUG_ONLY(old_location->char_field_put(old_offset, 0));
++            break;
++
++          case T_FLOAT:
++            new_location->float_field_put(offset, old_location->float_field(old_offset));
++            DEBUG_ONLY(old_location->float_field_put(old_offset, 0));
++            break;
++
++          case T_DOUBLE:
++            new_location->double_field_put(offset, old_location->double_field(old_offset));
++            DEBUG_ONLY(old_location->double_field_put(old_offset, 0));
++            break;
++
++          case T_BYTE:
++            new_location->byte_field_put(offset, old_location->byte_field(old_offset));
++            DEBUG_ONLY(old_location->byte_field_put(old_offset, 0));
++            break;
++
++          case T_SHORT:
++            new_location->short_field_put(offset, old_location->short_field(old_offset));
++            DEBUG_ONLY(old_location->short_field_put(old_offset, 0));
++            break;
++
++          case T_INT:
++            new_location->int_field_put(offset, old_location->int_field(old_offset));
++            DEBUG_ONLY(old_location->int_field_put(old_offset, 0));
++            break;
++
++          case T_LONG:
++            new_location->long_field_put(offset, old_location->long_field(old_offset));
++            DEBUG_ONLY(old_location->long_field_put(old_offset, 0));
++            break;
++
++          case T_OBJECT:
++          case T_ARRAY:
++            cur_oop = old_location->obj_field(old_offset);
++            new_location->obj_field_put_raw(offset, cur_oop);
++            old_location->obj_field_put_raw(old_offset, NULL);
++            break;
++
++          default:
++            ShouldNotReachHere();
++        }
++      } else {
++        RC_TRACE(0x00000200, ("New static field %s has_initial_value=%d",
++          fd->name()->as_C_string(), (int)(fd->has_initial_value())));
++        // field not found
++        // (tw) TODO: Probably this call is not necessary here!
++        // FIXME: idubrov
++        //ClassFileParser::initialize_static_field(fd, Thread::current());
++      }
++    }
++  };
++
++  UpdateStaticFieldClosure cl(this_oop);
++  this->do_local_static_fields(&cl);
++}
++
++
+ bool instanceKlass::verify_code(
+     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
+   // 1) Verify the bytecodes
+   Verifier::Mode mode =
+     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
+-  return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
++  return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), true, CHECK_false);
+ }
+ 
+ 
+@@ -362,7 +468,13 @@ bool instanceKlass::link_class_impl(
+                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
+                                    jt->get_thread_stat()->perf_timers_addr(),
+                                    PerfClassTraceTime::CLASS_VERIFY);
+-          bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
++          if (this_oop->is_redefining()) {
++            Thread::current()->set_pretend_new_universe(true);
++          }
++          bool verify_ok  = verify_code(this_oop, throw_verifyerror, THREAD);
++          if (this_oop->is_redefining()) {
++            Thread::current()->set_pretend_new_universe(false);
++          }
+           if (!verify_ok) {
+             return false;
+           }
+@@ -400,7 +512,8 @@ bool instanceKlass::link_class_impl(
+       }
+ #endif
+       this_oop->set_init_state(linked);
+-      if (JvmtiExport::should_post_class_prepare()) {
++      // (tw) Must check for old version in order to prevent infinite loops.
++      if (JvmtiExport::should_post_class_prepare() && this_oop->old_version() == NULL /* JVMTI deadlock otherwise */) {
+         Thread *thread = THREAD;
+         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
+         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
+@@ -673,6 +786,18 @@ bool instanceKlass::implements_interface(klassOop k) const {
+   return false;
+ }
+ 
++bool instanceKlass::implements_interface_any_version(klassOop k) const {
++  k = k->klass_part()->newest_version();
++  if (this->newest_version() == k) return true;
++  assert(Klass::cast(k)->is_interface(), "should be an interface class");
++  for (int i = 0; i < transitive_interfaces()->length(); i++) {
++    if (((klassOop)transitive_interfaces()->obj_at(i))->klass_part()->newest_version() == k) {
++      return true;
++    }
++  }
++  return false;
++}
++
+ objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
+   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
+   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
+@@ -801,7 +926,25 @@ methodOop instanceKlass::class_initializer() {
+ }
+ 
+ void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
++
++  ResourceMark rm(THREAD);
+   methodHandle h_method(THREAD, this_oop->class_initializer());
++
++  if (this_oop->revision_number() != -1){
++    methodOop m = NULL;
++    if (AllowAdvancedClassRedefinition) {
++      m = this_oop->find_method(vmSymbols::static_transformer_name(), vmSymbols::void_method_signature());
++    }
++    methodHandle method(m);
++    if (method() != NULL && method()->is_static()) {
++      RC_TRACE(0x00000200, ("Calling static transformer instead of static initializer"));
++      h_method = method;
++    } else if (!((instanceKlass*)this_oop->old_version()->klass_part())->is_not_initialized()) {
++      // Only execute the static initializer, if it was not yet executed for the old version of the class.
++      return;
++    }
++  }
++
+   assert(!this_oop->is_initialized(), "we cannot initialize twice");
+   if (TraceClassInitialization) {
+     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
+@@ -949,6 +1092,137 @@ void instanceKlass::methods_do(void f(methodOop method)) {
+   }
+ }
+ 
++void instanceKlass::store_update_information(GrowableArray<int> &values) {
++  int *arr = NEW_C_HEAP_ARRAY(int, values.length(), mtClass);
++  for (int i=0; i<values.length(); i++) {
++    arr[i] = values.at(i);
++  }
++  set_update_information(arr);
++}
++
++void instanceKlass::clear_update_information() {
++  FREE_C_HEAP_ARRAY(int, update_information(), mtClass);
++  set_update_information(NULL);
++}
++
++typedef Pair<int, klassOop> typeInfoPair;
++
++void instanceKlass::store_type_check_information(GrowableArray< Pair<int, klassOop> > &values) {
++  Pair<int, klassOop> *arr = NEW_C_HEAP_ARRAY(typeInfoPair, values.length(), mtClass);
++  for (int i=0; i<values.length(); i++) {
++    arr[i] = values.at(i);
++  }
++  set_type_check_information(arr);
++}
++
++void instanceKlass::clear_type_check_information() {
++  FREE_C_HEAP_ARRAY(typeInfoPair, type_check_information(), mtClass);
++  set_type_check_information(NULL);
++}
++
++void instanceKlass::do_fields_evolution(FieldEvolutionClosure* cl) {
++
++  assert (old_version() != NULL, "must have old version!");
++
++  klassOop old_klass_oop = old_version();
++  instanceKlass *old_klass = instanceKlass::cast(old_klass_oop);
++  instanceKlass *new_klass = this;
++
++  fieldDescriptor fd;
++  fieldDescriptor old_fd;
++
++  instanceKlass *cur_new_klass = new_klass;
++  klassOop cur_new_klass_oop = this->as_klassOop();
++
++  if (_fields_not_changed) {
++
++    class MyFieldClosure : public FieldClosure {
++
++      FieldEvolutionClosure *_cl;
++    public:
++      MyFieldClosure(FieldEvolutionClosure *cl) {_cl = cl; }
++      virtual void do_field(fieldDescriptor* fd) {
++        _cl->do_changed_field(fd, fd);
++      }
++    };
++
++    MyFieldClosure mfc(cl);
++    do_nonstatic_fields(&mfc);
++  } else {
++
++    _fields_not_changed = true;
++    GrowableArray<fieldDescriptor> fds;
++    while (true) {
++      for (JavaFieldStream fs(cur_new_klass); !fs.done(); fs.next()) {
++        fd.initialize(cur_new_klass_oop, fs.index());
++        if (fd.is_static()) {
++          continue;
++        }
++        fds.append(fd);
++      }
++
++      if (cur_new_klass->super() != NULL) {
++        cur_new_klass_oop = cur_new_klass->super();
++        cur_new_klass = instanceKlass::cast(cur_new_klass_oop);
++      } else {
++        break;
++      }
++    }
++
++    GrowableArray<fieldDescriptor> sortedFds;
++    while (fds.length() > 0) {
++      int minOffset = 0x7fffffff;
++      int minIndex = -1;
++      for (int i=0; i<fds.length(); i++) {
++        int curOffset = fds.adr_at(i)->offset();
++        if (curOffset < minOffset) {
++          minOffset = curOffset;
++          minIndex = i;
++        }
++      }
++
++      sortedFds.append(fds.at(minIndex));
++      fds.remove_at(minIndex);
++    }
++
++
++    for (int i=0; i<sortedFds.length(); i++) {
++      fieldDescriptor &fd = *sortedFds.adr_at(i);
++
++      char found = 0;
++      instanceKlass *cur_old_klass = old_klass;
++      klassOop cur_old_klass_oop = old_klass_oop;
++      while (true) {
++        for (JavaFieldStream fs(cur_old_klass); !fs.done(); fs.next()) {
++          old_fd.initialize(cur_old_klass_oop, fs.index());
++          if (old_fd.is_static()) {
++            continue;
++          }
++          if (old_fd.name() == fd.name() && old_fd.signature() == fd.signature()) {
++            found = 1;
++            break;
++          }
++        }
++        if (!found && cur_old_klass->super()) {
++          cur_old_klass_oop = cur_old_klass->super();
++          cur_old_klass = instanceKlass::cast(cur_old_klass_oop);
++        } else {
++          break;
++        }
++      }
++
++      if (found) {
++        if (old_fd.offset() != fd.offset()) {
++          _fields_not_changed = false;
++        }
++        cl->do_changed_field(&old_fd, &fd);
++      } else {
++        _fields_not_changed = false;
++        cl->do_new_field(&fd);
++      }
++    }
++  }
++}
+ 
+ void instanceKlass::do_local_static_fields(FieldClosure* cl) {
+   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
+@@ -1368,6 +1642,20 @@ jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
+   return id;
+ }
+ 
++bool instanceKlass::update_jmethod_id(methodOop method, jmethodID newMethodID) {
++  size_t idnum = (size_t)method->method_idnum();
++  jmethodID* jmeths = methods_jmethod_ids_acquire();
++  size_t length;                                // length assigned as debugging crumb
++  jmethodID id = NULL;
++  if (jmeths != NULL &&                         // If there is a cache
++    (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
++      jmeths[idnum+1] = newMethodID;                       // Set the id (may be NULL)
++      return true;
++  }
++
++  return false;
++}
++
+ 
+ // Cache an itable index
+ void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
+@@ -1527,6 +1815,13 @@ void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
+     last = b;
+     b = b->next();
+   }
++
++  // (tw) Hack as dependencies get wrong version of klassOop
++  if(this->old_version() != NULL) {
++    ((instanceKlass *)this->old_version()->klass_part())->remove_dependent_nmethod(nm);
++    return;
++  }
++
+ #ifdef ASSERT
+   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
+   nm->print();
+@@ -2417,6 +2712,9 @@ void instanceKlass::oop_print_on(oop obj, outputStream* st) {
+     klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
+     st->print(BULLET"fake entry for mirror: ");
+     mirrored_klass->print_value_on(st);
++    if (mirrored_klass != NULL) {
++      st->print_cr("revision: %d (oldest=%d, newest=%d)", mirrored_klass->klass_part()->revision_number(), mirrored_klass->klass_part()->oldest_version()->klass_part()->revision_number(), mirrored_klass->klass_part()->newest_version()->klass_part()->revision_number());
++    }
+     st->cr();
+     st->print(BULLET"fake entry resolved_constructor: ");
+     methodOop ctor = java_lang_Class::resolved_constructor(obj);
+diff --git a/src/share/vm/oops/instanceKlass.hpp b/src/share/vm/oops/instanceKlass.hpp
+index bb613b0..71f0083 100644
+--- a/src/share/vm/oops/instanceKlass.hpp
++++ b/src/share/vm/oops/instanceKlass.hpp
+@@ -102,6 +102,22 @@ public:
+   virtual void do_field(fieldDescriptor* fd) = 0;
+ };
+ 
++// (tw) Iterates over the fields of the old and new class
++class FieldEvolutionClosure : public StackObj {
++public:
++  virtual void do_new_field(fieldDescriptor* fd) = 0;
++  virtual void do_old_field(fieldDescriptor* fd) = 0;
++  virtual void do_changed_field(fieldDescriptor* old_fd, fieldDescriptor *new_fd) = 0;
++};
++
++// (tw) Iterates over the methods of the old and new class
++class MethodEvolutionClosure : public StackObj {
++public:
++  virtual void do_new_method(methodOop oop) = 0;
++  virtual void do_old_method(methodOop oop) = 0;
++  virtual void do_changed_method(methodOop oldOop, methodOop newOop) = 0;
++};
++
+ #ifndef PRODUCT
+ // Print fields.
+ // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
+@@ -287,6 +303,11 @@ class instanceKlass: public Klass {
+   // _idnum_allocated_count.
+   u1              _init_state;                    // state of class
+ 
++  // (tw) Field that allows for a short-path when calculating updated fields for the second time and
++  // no fields changed. Testing performance impact with this, can be removed later when the update
++  // information is cached.
++  bool            _fields_not_changed;
++
+   u1              _reference_type;                // reference type
+ 
+   // embedded Java vtable follows here
+@@ -454,6 +475,7 @@ class instanceKlass: public Klass {
+   // initialization (virtuals from Klass)
+   bool should_be_initialized() const;  // means that initialize should be called
+   void initialize(TRAPS);
++  void initialize_redefined_class();
+   void link_class(TRAPS);
+   bool link_class_or_fail(TRAPS); // returns false on failure
+   void unlink_class();
+@@ -631,6 +653,7 @@ class instanceKlass: public Klass {
+   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
+                 size_t *length_p, jmethodID* id_p);
+   jmethodID jmethod_id_or_null(methodOop method);
++  bool update_jmethod_id(methodOop method, jmethodID newMethodID);
+ 
+   // cached itable index support
+   void set_cached_itable_index(size_t idnum, int index);
+@@ -713,6 +736,7 @@ class instanceKlass: public Klass {
+ 
+   // subclass/subinterface checks
+   bool implements_interface(klassOop k) const;
++  bool implements_interface_any_version(klassOop k) const;
+ 
+   // Access to the implementor of an interface.
+   klassOop implementor() const
+@@ -762,6 +786,12 @@ class instanceKlass: public Klass {
+   void do_local_static_fields(FieldClosure* cl);
+   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
+   void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
++  void do_fields_evolution(FieldEvolutionClosure *cl);
++  void store_update_information(GrowableArray<int> &values);
++  void clear_update_information();
++  void store_type_check_information(GrowableArray< Pair<int, klassOop> > &values);
++  void clear_type_check_information();
++
+ 
+   void methods_do(void f(methodOop method));
+   void array_klasses_do(void f(klassOop k));
+diff --git a/src/share/vm/oops/instanceKlassKlass.cpp b/src/share/vm/oops/instanceKlassKlass.cpp
+index 8e7dc12..63d6dc4 100644
+--- a/src/share/vm/oops/instanceKlassKlass.cpp
++++ b/src/share/vm/oops/instanceKlassKlass.cpp
+@@ -480,6 +480,28 @@ void instanceKlassKlass::oop_print_on(oop obj, outputStream* st) {
+   instanceKlass* ik = instanceKlass::cast(klassOop(obj));
+   klassKlass::oop_print_on(obj, st);
+ 
++  // (tw) Output revision number and revision numbers of older / newer and oldest / newest version of this class.
++
++  st->print(BULLET"revision:          %d", ik->revision_number());                    
++  
++  if (ik->new_version() != NULL) {
++    st->print(" (newer=%d)", ik->new_version()->klass_part()->revision_number());
++  }
++
++  if (ik->newest_version() != ik->new_version() && ik->newest_version() != obj) {
++    st->print(" (newest=%d)", ik->newest_version()->klass_part()->revision_number());
++  }
++
++  if (ik->old_version() != NULL) {
++    st->print(" (old=%d)", ik->old_version()->klass_part()->revision_number());
++  }
++
++  if (ik->oldest_version() != ik->old_version() && ik->oldest_version() != obj) {
++    st->print(" (oldest=%d)", ik->oldest_version()->klass_part()->revision_number());
++  }
++
++  st->cr();
++  
+   st->print(BULLET"instance size:     %d", ik->size_helper());                        st->cr();
+   st->print(BULLET"klass size:        %d", ik->object_size());                        st->cr();
+   st->print(BULLET"access:            "); ik->access_flags().print_on(st);            st->cr();
+@@ -663,7 +685,7 @@ void instanceKlassKlass::oop_verify_on(oop obj, outputStream* st) {
+       }
+       guarantee(sib->as_klassOop()->is_klass(), "should be klass");
+       guarantee(sib->as_klassOop()->is_perm(),  "should be in permspace");
+-      guarantee(sib->super() == super, "siblings should have same superklass");
++      guarantee(sib->super() == super || super->klass_part()->newest_version() == SystemDictionary::Object_klass(), "siblings should have same superklass");
+       sib = sib->next_sibling();
+     }
+ 
+diff --git a/src/share/vm/oops/instanceRefKlass.cpp b/src/share/vm/oops/instanceRefKlass.cpp
+index 7db4f03..1171487 100644
+--- a/src/share/vm/oops/instanceRefKlass.cpp
++++ b/src/share/vm/oops/instanceRefKlass.cpp
+@@ -455,10 +455,13 @@ void instanceRefKlass::update_nonstatic_oop_maps(klassOop k) {
+   instanceKlass* ik = instanceKlass::cast(k);
+ 
+   // Check that we have the right class
+-  debug_only(static bool first_time = true);
+-  assert(k == SystemDictionary::Reference_klass() && first_time,
+-         "Invalid update of maps");
+-  debug_only(first_time = false);
++  
++  // (tw) Asserts no longer valid for class redefinition
++  // debug_only(static bool first_time = true);
++  
++  //assert(k == SystemDictionary::Reference_klass() && first_time,
++  //       "Invalid update of maps");
++  //debug_only(first_time = false);
+   assert(ik->nonstatic_oop_map_count() == 1, "just checking");
+ 
+   OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
+diff --git a/src/share/vm/oops/klass.cpp b/src/share/vm/oops/klass.cpp
+index ff33181..28537e2 100644
+--- a/src/share/vm/oops/klass.cpp
++++ b/src/share/vm/oops/klass.cpp
+@@ -55,6 +55,26 @@ bool Klass::is_subclass_of(klassOop k) const {
+   return false;
+ }
+ 
++void Klass::update_supers_to_newest_version() {
++
++  if (super() != NULL) set_super(super()->klass_part()->newest_version());
++  
++  for (uint i=0; i<primary_super_limit(); i++) {
++    klassOop cur = _primary_supers[i];
++    if (cur != NULL) {
++      _primary_supers[i] = cur->klass_part()->newest_version();
++    }
++  }
++
++  // Scan the array-of-objects 
++  int cnt = secondary_supers()->length();
++  for (int i = 0; i < cnt; i++) {
++    klassOop cur = (klassOop)secondary_supers()->obj_at(i);
++    if (cur != NULL) {
++      secondary_supers()->obj_at_put(i, cur->klass_part()->newest_version());
++    }
++  }
++}
+ bool Klass::search_secondary_supers(klassOop k) const {
+   // Put some extra logic here out-of-line, before the search proper.
+   // This cuts down the size of the inline method.
+@@ -170,6 +190,16 @@ klassOop Klass::base_create_klass_oop(KlassHandle& klass, int size,
+   kl->set_alloc_size(0);
+   TRACE_INIT_ID(kl);
+ 
++  kl->set_redefinition_flags(Klass::NoRedefinition);
++  kl->set_redefining(false);
++  kl->set_new_version(NULL);
++  kl->set_old_version(NULL);
++  kl->set_redefinition_index(-1);
++  kl->set_revision_number(-1);
++  kl->set_field_redefinition_policy(DynamicCheck);
++  kl->set_static_field_redefinition_policy(AccessDeletedMembers);
++  kl->set_method_redefinition_policy(AccessDeletedMembers);
++
+   kl->set_prototype_header(markOopDesc::prototype());
+   kl->set_biased_lock_revocation_count(0);
+   kl->set_last_biased_lock_bulk_revocation_time(0);
+@@ -241,7 +271,7 @@ void Klass::initialize_supers(klassOop k, TRAPS) {
+     set_super(NULL);
+     oop_store_without_check((oop*) &_primary_supers[0], (oop) this->as_klassOop());
+     assert(super_depth() == 0, "Object must already be initialized properly");
+-  } else if (k != super() || k == SystemDictionary::Object_klass()) {
++  } else if (k != super() || k->klass_part()->super() == NULL) {
+     assert(super() == NULL || super() == SystemDictionary::Object_klass(),
+            "initialize this only once to a non-trivial value");
+     set_super(k);
+diff --git a/src/share/vm/oops/klass.hpp b/src/share/vm/oops/klass.hpp
+index a449e87..52364ba 100644
+--- a/src/share/vm/oops/klass.hpp
++++ b/src/share/vm/oops/klass.hpp
+@@ -171,6 +171,7 @@ class Klass_vtbl {
+   void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS);
+ };
+ 
++template<class L, class R> class Pair;
+ 
+ class Klass : public Klass_vtbl {
+   friend class VMStructs;
+@@ -223,6 +224,39 @@ class Klass : public Klass_vtbl {
+   oop* oop_block_beg() const { return adr_secondary_super_cache(); }
+   oop* oop_block_end() const { return adr_next_sibling() + 1; }
+ 
++  // (tw) Different class redefinition flags of code evolution.
++  enum RedefinitionFlags {
++
++    // This class is not redefined at all!
++    NoRedefinition,
++
++    // There are changes to the class meta data.
++    ModifyClass = 1,
++
++    // The size of the class meta data changes.
++    ModifyClassSize = ModifyClass << 1,
++
++    // There are change to the instance format.
++    ModifyInstances = ModifyClassSize << 1,
++
++    // The size of instances changes.
++    ModifyInstanceSize = ModifyInstances << 1,
++
++    // A super type of this class is removed.
++    RemoveSuperType = ModifyInstanceSize << 1,
++
++    // This class (or one of its super classes) has an instance transformer method.
++    HasInstanceTransformer = RemoveSuperType << 1,
++  };
++
++  // (tw) Different policies dealing with deleted fields / methods in old code.
++  enum RedefinitionPolicy {
++    StaticCheck,
++    DynamicCheck,
++    AccessDeletedMembers,
++    AccessOldMembers
++  };
++
+  protected:
+   //
+   // The oop block.  All oop fields must be declared here and only oop fields
+@@ -242,6 +276,10 @@ class Klass : public Klass_vtbl {
+   oop       _java_mirror;
+   // Superclass
+   klassOop  _super;
++  // Old class
++  klassOop _old_version;
++  // New class
++  klassOop _new_version;
+   // First subclass (NULL if none); _subklass->next_sibling() is next one
+   klassOop _subklass;
+   // Sibling link (or NULL); links all subklasses of a klass
+@@ -254,6 +292,19 @@ class Klass : public Klass_vtbl {
+   jint        _modifier_flags;  // Processed access flags, for use by Class.getModifiers.
+   AccessFlags _access_flags;    // Access flags. The class/interface distinction is stored here.
+ 
++  // (tw) Non-oop fields for enhanced class redefinition
++  jint                  _revision_number;        // The revision number for redefined classes
++  jint                  _redefinition_index;     // Index of this class when performing the redefinition
++  bool                  _subtype_changed;
++  int                   _redefinition_flags;     // Level of class redefinition
++  bool                  _is_copying_backwards;   // Does the class need to copy fields backwards? => possibly overwrite itself?
++  int *                 _update_information;     // Update information
++  Pair<int, klassOop> * _type_check_information; // Offsets of object fields that need a type check
++  char                  _method_redefinition_policy;
++  char                  _field_redefinition_policy;
++  char                  _static_field_redefinition_policy;
++  bool                  _is_redefining;
++
+ #ifndef PRODUCT
+   int           _verify_count;  // to avoid redundant verifies
+ #endif
+@@ -302,6 +353,99 @@ class Klass : public Klass_vtbl {
+   klassOop secondary_super_cache() const     { return _secondary_super_cache; }
+   void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); }
+ 
++  // BEGIN class redefinition utilities
++
++  // double links between new and old version of a class
++  klassOop old_version() const                         { return _old_version; }
++  void set_old_version(klassOop klass)                 { assert(_old_version == NULL || klass == NULL, "Can only be set once!"); _old_version = klass; }
++  klassOop new_version() const                         { return _new_version; }
++  void set_new_version(klassOop klass)                 { assert(_new_version == NULL || klass == NULL, "Can only be set once!"); _new_version = klass; }
++
++  // A subtype of this class is no longer a subtype
++  bool has_subtype_changed() const                     { return _subtype_changed; }
++  void set_subtype_changed(bool b)                     { assert(is_newest_version() || new_version()->klass_part()->is_newest_version(), "must be newest or second newest version");
++                                                         _subtype_changed = b; }
++  // state of being redefined
++  int redefinition_index() const                       { return _redefinition_index; }
++  void set_redefinition_index(int index)               { _redefinition_index = index; }
++  void set_redefining(bool b)                          { _is_redefining = b; }
++  bool is_redefining() const                           { return _is_redefining; }
++  int redefinition_flags() const                       { return _redefinition_flags; }
++  bool check_redefinition_flag(int flags) const        { return (_redefinition_flags & flags) != 0; }
++  void set_redefinition_flags(int flags)               { _redefinition_flags = flags; }
++  bool is_copying_backwards() const                    { return _is_copying_backwards; }
++  void set_copying_backwards(bool b)                   { _is_copying_backwards = b; }
++
++  // update information
++  int *update_information() const                      { return _update_information; }
++  void set_update_information(int *info)               { _update_information = info; }
++  Pair<int, klassOop> *type_check_information() const        { return _type_check_information; }
++  void set_type_check_information(Pair<int, klassOop> *info) { _type_check_information = info; }
++
++  bool is_same_or_older_version(klassOop klass) const {
++    if (Klass::cast(klass) == this) { return true; }
++    else if (_old_version == NULL) { return false; }
++    else { return _old_version->klass_part()->is_same_or_older_version(klass); }
++  }
++
++  // Revision number for redefined classes, -1 for originally loaded classes
++  jint revision_number() const {
++    return _revision_number;
++  }
++
++  bool was_redefined() const {
++    return _revision_number != -1;
++  }
++
++  void set_revision_number(jint number) {
++    _revision_number = number;
++  }
++
++  char method_redefinition_policy() {
++    return _method_redefinition_policy;
++  }
++
++  void set_method_redefinition_policy(char v) {
++    _method_redefinition_policy = v;
++  }
++
++  char field_redefinition_policy() {
++    return _field_redefinition_policy;
++  }
++
++  void set_field_redefinition_policy(char v) {
++    _field_redefinition_policy = v;
++  }
++
++  char static_field_redefinition_policy() {
++	  return _static_field_redefinition_policy;
++  }
++
++  void set_static_field_redefinition_policy(char v) {
++	  _static_field_redefinition_policy = v;
++  }
++
++  klassOop oldest_version() const {
++    if (_old_version == NULL) { return this->as_klassOop(); }
++    else { return _old_version->klass_part()->oldest_version(); };
++  }
++
++  klassOop newest_version() const {
++    if (_new_version == NULL) { return this->as_klassOop(); }
++    else { return _new_version->klass_part()->newest_version(); };
++  }
++
++  klassOop active_version() const {
++    if (_new_version == NULL || _new_version->klass_part()->is_redefining()) { return this->as_klassOop(); assert(!this->is_redefining(), "just checking"); }
++    else { return _new_version->klass_part()->active_version(); };
++  }
++
++  bool is_newest_version() const {
++    return _new_version == NULL;
++  }
++
++  // END class redefinition utilities
++
+   objArrayOop secondary_supers() const { return _secondary_supers; }
+   void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); }
+ 
+@@ -362,6 +506,8 @@ class Klass : public Klass_vtbl {
+   void     set_next_sibling(klassOop s);
+ 
+   oop* adr_super()           const { return (oop*)&_super;             }
++  oop* adr_old_version()           const { return (oop*)&_old_version; }
++  oop* adr_new_version()           const { return (oop*)&_new_version; }
+   oop* adr_primary_supers()  const { return (oop*)&_primary_supers[0]; }
+   oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; }
+   oop* adr_secondary_supers()const { return (oop*)&_secondary_supers;  }
+@@ -491,6 +637,7 @@ class Klass : public Klass_vtbl {
+       return search_secondary_supers(k);
+     }
+   }
++  void update_supers_to_newest_version();
+   bool search_secondary_supers(klassOop k) const;
+ 
+   // Find LCA in class hierarchy
+@@ -818,6 +965,8 @@ class Klass : public Klass_vtbl {
+ 
+ 
+ inline oop klassOopDesc::java_mirror() const                        { return klass_part()->java_mirror(); }
++inline klassOop klassOopDesc::old_version() const                   { return klass_part()->old_version(); }
++inline klassOop klassOopDesc::new_version() const                   { return klass_part()->new_version(); }
+ 
+ 
+ #endif // SHARE_VM_OOPS_KLASS_HPP
+diff --git a/src/share/vm/oops/klassKlass.cpp b/src/share/vm/oops/klassKlass.cpp
+index 06809d5..9c08f32 100644
+--- a/src/share/vm/oops/klassKlass.cpp
++++ b/src/share/vm/oops/klassKlass.cpp
+@@ -68,6 +68,8 @@ void klassKlass::oop_follow_contents(oop obj) {
+   Klass* k = Klass::cast(klassOop(obj));
+   // If we are alive it is valid to keep our superclass and subtype caches alive
+   MarkSweep::mark_and_push(k->adr_super());
++  MarkSweep::mark_and_push(k->adr_old_version());
++  MarkSweep::mark_and_push(k->adr_new_version());
+   for (juint i = 0; i < Klass::primary_super_limit(); i++)
+     MarkSweep::mark_and_push(k->adr_primary_supers()+i);
+   MarkSweep::mark_and_push(k->adr_secondary_super_cache());
+@@ -87,6 +89,8 @@ void klassKlass::oop_follow_contents(ParCompactionManager* cm,
+   Klass* k = Klass::cast(klassOop(obj));
+   // If we are alive it is valid to keep our superclass and subtype caches alive
+   PSParallelCompact::mark_and_push(cm, k->adr_super());
++  PSParallelCompact::mark_and_push(cm, k->adr_old_version());
++  PSParallelCompact::mark_and_push(cm, k->adr_new_version());
+   for (juint i = 0; i < Klass::primary_super_limit(); i++)
+     PSParallelCompact::mark_and_push(cm, k->adr_primary_supers()+i);
+   PSParallelCompact::mark_and_push(cm, k->adr_secondary_super_cache());
+@@ -106,6 +110,8 @@ int klassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
+   int size = oop_size(obj);
+   Klass* k = Klass::cast(klassOop(obj));
+   blk->do_oop(k->adr_super());
++  blk->do_oop(k->adr_old_version());
++  blk->do_oop(k->adr_new_version());
+   for (juint i = 0; i < Klass::primary_super_limit(); i++)
+     blk->do_oop(k->adr_primary_supers()+i);
+   blk->do_oop(k->adr_secondary_super_cache());
+@@ -134,6 +140,10 @@ int klassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
+   oop* adr;
+   adr = k->adr_super();
+   if (mr.contains(adr)) blk->do_oop(adr);
++  adr = k->adr_old_version();
++  if (mr.contains(adr)) blk->do_oop(adr);
++  adr = k->adr_new_version();
++  if (mr.contains(adr)) blk->do_oop(adr);
+   for (juint i = 0; i < Klass::primary_super_limit(); i++) {
+     adr = k->adr_primary_supers()+i;
+     if (mr.contains(adr)) blk->do_oop(adr);
+@@ -147,6 +157,8 @@ int klassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
+   // The following are "weak links" in the perm gen and are
+   // treated specially in a later phase of a perm gen collection.
+   assert(oop(k)->is_perm(), "should be in perm");
++  assert(oop(k->adr_old_version())->is_perm(), "should be in perm");
++  assert(oop(k->adr_new_version())->is_perm(), "should be in perm");
+   assert(oop(k->adr_subklass())->is_perm(), "should be in perm");
+   assert(oop(k->adr_next_sibling())->is_perm(), "should be in perm");
+   if (blk->should_remember_klasses()
+@@ -167,6 +179,8 @@ int klassKlass::oop_adjust_pointers(oop obj) {
+   Klass* k = Klass::cast(klassOop(obj));
+ 
+   MarkSweep::adjust_pointer(k->adr_super());
++  MarkSweep::adjust_pointer(k->adr_new_version());
++  MarkSweep::adjust_pointer(k->adr_old_version());
+   for (juint i = 0; i < Klass::primary_super_limit(); i++)
+     MarkSweep::adjust_pointer(k->adr_primary_supers()+i);
+   MarkSweep::adjust_pointer(k->adr_secondary_super_cache());
+diff --git a/src/share/vm/oops/klassOop.hpp b/src/share/vm/oops/klassOop.hpp
+index f212fc5..9731a9c 100644
+--- a/src/share/vm/oops/klassOop.hpp
++++ b/src/share/vm/oops/klassOop.hpp
+@@ -41,8 +41,10 @@ class klassOopDesc : public oopDesc {
+   // returns the Klass part containing dispatching behavior
+   Klass* klass_part() const                      { return (Klass*)((address)this + sizeof(klassOopDesc)); }
+ 
+-  // Convenience wrapper
++  // Convenience wrappers
+   inline oop java_mirror() const;
++  inline klassOop old_version() const;
++  inline klassOop new_version() const;
+ 
+  private:
+   // These have no implementation since klassOop should never be accessed in this fashion
+diff --git a/src/share/vm/oops/klassVtable.cpp b/src/share/vm/oops/klassVtable.cpp
+index ff22444..8d39611 100644
+--- a/src/share/vm/oops/klassVtable.cpp
++++ b/src/share/vm/oops/klassVtable.cpp
+@@ -97,7 +97,8 @@ void klassVtable::compute_vtable_size_and_num_mirandas(int &vtable_length,
+     vtable_length = Universe::base_vtable_size();
+   }
+ 
+-  if (super == NULL && !Universe::is_bootstrapping() &&
++  // (tw) TODO: Check if we can relax the condition on a fixed base vtable size
++  /*if (super == NULL && !Universe::is_bootstrapping() &&
+       vtable_length != Universe::base_vtable_size()) {
+     // Someone is attempting to redefine java.lang.Object incorrectly.  The
+     // only way this should happen is from
+@@ -107,9 +108,9 @@ void klassVtable::compute_vtable_size_and_num_mirandas(int &vtable_length,
+     vtable_length = Universe::base_vtable_size();
+   }
+   assert(super != NULL || vtable_length == Universe::base_vtable_size(),
+-         "bad vtable size for class Object");
++         "bad vtable size for class Object");*/
+   assert(vtable_length % vtableEntry::size() == 0, "bad vtable length");
+-  assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
++  //assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
+ }
+ 
+ int klassVtable::index_of(methodOop m, int len) const {
+@@ -678,20 +679,6 @@ bool klassVtable::check_no_old_or_obsolete_entries() {
+   return true;
+ }
+ 
+-void klassVtable::dump_vtable() {
+-  tty->print_cr("vtable dump --");
+-  for (int i = 0; i < length(); i++) {
+-    methodOop m = unchecked_method_at(i);
+-    if (m != NULL) {
+-      tty->print("      (%5d)  ", i);
+-      m->access_flags().print_on(tty);
+-      tty->print(" --  ");
+-      m->print_name(tty);
+-      tty->cr();
+-    }
+-  }
+-}
+-
+ // CDS/RedefineClasses support - clear vtables so they can be reinitialized
+ void klassVtable::clear_vtable() {
+   for (int i = 0; i < _length; i++) table()[i].clear();
+@@ -1262,6 +1249,7 @@ void klassVtable::verify(outputStream* st, bool forced) {
+ 
+ void klassVtable::verify_against(outputStream* st, klassVtable* vt, int index) {
+   vtableEntry* vte = &vt->table()[index];
++  if (vte->method() == NULL || table()[index].method() == NULL) return;
+   if (vte->method()->name()      != table()[index].method()->name() ||
+       vte->method()->signature() != table()[index].method()->signature()) {
+     fatal("mismatched name/signature of vtable entries");
+@@ -1281,6 +1269,8 @@ void klassVtable::print() {
+ 
+ void vtableEntry::verify(klassVtable* vt, outputStream* st) {
+   NOT_PRODUCT(FlagSetting fs(IgnoreLockingAssertions, true));
++  // (tw) TODO: Check: Does not hold?
++  if (method() != NULL) {
+   assert(method() != NULL, "must have set method");
+   method()->verify();
+   // we sub_type, because it could be a miranda method
+@@ -1288,7 +1278,13 @@ void vtableEntry::verify(klassVtable* vt, outputStream* st) {
+ #ifndef PRODUCT
+     print();
+ #endif
+-    fatal(err_msg("vtableEntry " PTR_FORMAT ": method is from subclass", this));
++      klassOop first_klass = vt->klass()();
++      klassOop second_klass = method()->method_holder();
++      // (tw) the following fatal does not work for old versions of classes
++      if (first_klass->klass_part()->is_newest_version()) {
++        //fatal1("vtableEntry %#lx: method is from subclass", this);
++      }
++    }
+   }
+ }
+ 
+@@ -1296,7 +1292,7 @@ void vtableEntry::verify(klassVtable* vt, outputStream* st) {
+ 
+ void vtableEntry::print() {
+   ResourceMark rm;
+-  tty->print("vtableEntry %s: ", method()->name()->as_C_string());
++  tty->print("vtableEntry %s: ", (method() == NULL) ? "null" : method()->name()->as_C_string());
+   if (Verbose) {
+     tty->print("m %#lx ", (address)method());
+   }
+@@ -1363,6 +1359,33 @@ void klassVtable::print_statistics() {
+   tty->print_cr("%6d bytes total", total);
+ }
+ 
++bool klassVtable::check_no_old_entries() {
++  // Check that there really is no entry
++  for (int i = 0; i < length(); i++) {
++    methodOop m = unchecked_method_at(i);
++    if (m != NULL) {
++        if (m->is_old() || !m->method_holder()->klass_part()->is_newest_version()) {
++            return false;
++        }
++    }
++  }
++  return true;
++}
++
++void klassVtable::dump_vtable() {
++  tty->print_cr("vtable dump --");
++  for (int i = 0; i < length(); i++) {
++    methodOop m = unchecked_method_at(i);
++    if (m != NULL) {
++      tty->print("      (%5d)  ", i);
++      m->access_flags().print_on(tty);
++      tty->print(" --  ");
++      m->print_name(tty);
++      tty->cr();
++    }
++  }
++}
++
+ int  klassItable::_total_classes;   // Total no. of classes with itables
+ long klassItable::_total_size;      // Total no. of bytes used for itables
+ 
+diff --git a/src/share/vm/oops/klassVtable.hpp b/src/share/vm/oops/klassVtable.hpp
+index 405b0c7..0c8d2f7 100644
+--- a/src/share/vm/oops/klassVtable.hpp
++++ b/src/share/vm/oops/klassVtable.hpp
+@@ -100,6 +100,7 @@ class klassVtable : public ResourceObj {
+                              int methods_length, bool * trace_name_printed);
+   bool check_no_old_or_obsolete_entries();
+   void dump_vtable();
++  bool check_no_old_entries();
+ 
+   // Garbage collection
+   void oop_follow_contents();
+diff --git a/src/share/vm/oops/methodKlass.cpp b/src/share/vm/oops/methodKlass.cpp
+index 75d0b09..f1b7d2f 100644
+--- a/src/share/vm/oops/methodKlass.cpp
++++ b/src/share/vm/oops/methodKlass.cpp
+@@ -93,6 +93,10 @@ methodOop methodKlass::allocate(constMethodHandle xconst,
+   m->set_adapter_entry(NULL);
+   m->clear_code(); // from_c/from_i get set to c2i/i2i
+ 
++  m->set_forward_method(NULL);
++  m->set_new_version(NULL);
++  m->set_old_version(NULL);
++
+   if (access_flags.is_native()) {
+     m->clear_native_function();
+     m->set_signature_handler(NULL);
+@@ -122,6 +126,9 @@ void methodKlass::oop_follow_contents(oop obj) {
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::methodKlassObj never moves.
+   MarkSweep::mark_and_push(m->adr_constMethod());
++  MarkSweep::mark_and_push(m->adr_forward_method());
++  MarkSweep::mark_and_push(m->adr_new_version());
++  MarkSweep::mark_and_push(m->adr_old_version());
+   if (m->method_data() != NULL) {
+     MarkSweep::mark_and_push(m->adr_method_data());
+   }
+@@ -135,6 +142,9 @@ void methodKlass::oop_follow_contents(ParCompactionManager* cm,
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::methodKlassObj never moves.
+   PSParallelCompact::mark_and_push(cm, m->adr_constMethod());
++  PSParallelCompact::mark_and_push(cm, m->adr_forward_method());
++  PSParallelCompact::mark_and_push(cm, m->adr_new_version());
++  PSParallelCompact::mark_and_push(cm, m->adr_old_version());
+ #ifdef COMPILER2
+   if (m->method_data() != NULL) {
+     PSParallelCompact::mark_and_push(cm, m->adr_method_data());
+@@ -152,6 +162,9 @@ int methodKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::methodKlassObj never moves
+   blk->do_oop(m->adr_constMethod());
++  blk->do_oop(m->adr_forward_method());
++  blk->do_oop(m->adr_new_version());
++  blk->do_oop(m->adr_old_version());
+   if (m->method_data() != NULL) {
+     blk->do_oop(m->adr_method_data());
+   }
+@@ -170,6 +183,12 @@ int methodKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
+   oop* adr;
+   adr = m->adr_constMethod();
+   if (mr.contains(adr)) blk->do_oop(adr);
++  adr = m->adr_new_version();
++  if (mr.contains(adr)) blk->do_oop(adr);
++  adr = m->adr_forward_method();
++  if (mr.contains(adr)) blk->do_oop(adr);
++  adr = m->adr_old_version();
++  if (mr.contains(adr)) blk->do_oop(adr);
+   if (m->method_data() != NULL) {
+     adr = m->adr_method_data();
+     if (mr.contains(adr)) blk->do_oop(adr);
+@@ -187,6 +206,9 @@ int methodKlass::oop_adjust_pointers(oop obj) {
+   // Performance tweak: We skip iterating over the klass pointer since we
+   // know that Universe::methodKlassObj never moves.
+   MarkSweep::adjust_pointer(m->adr_constMethod());
++  MarkSweep::adjust_pointer(m->adr_forward_method());
++  MarkSweep::adjust_pointer(m->adr_new_version());
++  MarkSweep::adjust_pointer(m->adr_old_version());
+   if (m->method_data() != NULL) {
+     MarkSweep::adjust_pointer(m->adr_method_data());
+   }
+@@ -202,6 +224,9 @@ int methodKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
+   assert(obj->is_method(), "should be method");
+   methodOop m = methodOop(obj);
+   PSParallelCompact::adjust_pointer(m->adr_constMethod());
++  PSParallelCompact::adjust_pointer(m->adr_forward_method());
++  PSParallelCompact::adjust_pointer(m->adr_new_version());
++  PSParallelCompact::adjust_pointer(m->adr_old_version());
+ #ifdef COMPILER2
+   if (m->method_data() != NULL) {
+     PSParallelCompact::adjust_pointer(m->adr_method_data());
+@@ -222,7 +247,18 @@ void methodKlass::oop_print_on(oop obj, outputStream* st) {
+   methodOop m = methodOop(obj);
+   // get the effect of PrintOopAddress, always, for methods:
+   st->print_cr(" - this oop:          "INTPTR_FORMAT, (intptr_t)m);
+-  st->print   (" - method holder:     ");    m->method_holder()->print_value_on(st); st->cr();
++  st->print   (" - method holder:     ");    m->method_holder()->print_value_on(st);
++
++  if (m->method_holder()->klass_part()->new_version() != NULL) {
++    st->print(" (old)");
++  }
++  st->cr();
++
++  st->print_cr(" - is obsolete:       %d",   (int)(m->is_obsolete()));
++  st->print_cr(" - is old:            %d",   (int)(m->is_old()));
++  st->print_cr(" - new version:       "INTPTR_FORMAT" ",   (address)(m->new_version()));
++  st->print_cr(" - old version:       "INTPTR_FORMAT" ",   (address)(m->old_version()));
++  st->print_cr(" - holder revision:   %d", m->method_holder()->klass_part()->revision_number());
+   st->print   (" - constants:         "INTPTR_FORMAT" ", (address)m->constants());
+   m->constants()->print_value_on(st); st->cr();
+   st->print   (" - access:            0x%x  ", m->access_flags().as_int()); m->access_flags().print_on(st); st->cr();
+diff --git a/src/share/vm/oops/methodOop.cpp b/src/share/vm/oops/methodOop.cpp
+index 4f59d3a..5cdf147 100644
+--- a/src/share/vm/oops/methodOop.cpp
++++ b/src/share/vm/oops/methodOop.cpp
+@@ -328,6 +328,70 @@ void methodOopDesc::cleanup_inline_caches() {
+ }
+ 
+ 
++bool methodOopDesc::is_in_code_section(int bci) {
++  // There is no table => every bci is in the code section table.
++  if (!constMethod()->has_code_section_table()) return true;
++
++  constMethodOop m = constMethod();
++  for (int i = 0; i < m->code_section_entries(); ++i) {
++    u2 new_index = m->code_section_new_index_at(i);
++    u2 length = m->code_section_length_at(i);
++    if (bci >= new_index && bci < new_index + length) {
++      // We are in a specified code section.
++      return true;
++    }
++  }
++
++  return false;
++}
++
++int methodOopDesc::calculate_forward_bci(int bci, methodOop new_method) {
++  int original_bci = -1;
++  if (constMethod()->has_code_section_table()) {
++    assert(is_in_code_section(bci), "can only forward in section");
++    // First calculate back to original bci.
++    constMethodOop m = constMethod();
++    for (int i = 0; i < m->code_section_entries(); ++i) {
++      u2 new_index = m->code_section_new_index_at(i);
++      u2 original_index = m->code_section_original_index_at(i);
++      u2 length = m->code_section_length_at(i);
++      if (bci >= new_index && bci < new_index + length) {
++        // We are in a specified code section.
++        original_bci = bci - new_index + original_index;
++        break;
++      }
++    }
++    assert (original_bci != -1, "must have been in code section");
++  } else {
++    // No code sections specified => we are in an original method.
++    original_bci = bci;
++  }
++
++  // We know the original bci => match to new method.
++  int new_bci = -1;
++  if (new_method->constMethod()->has_code_section_table()) {
++    // Map to new bci.
++    constMethodOop m = new_method->constMethod();
++    for (int i = 0; i < m->code_section_entries(); ++i) {
++      u2 new_index = m->code_section_new_index_at(i);
++      u2 original_index = m->code_section_original_index_at(i);
++      u2 length = m->code_section_length_at(i);
++      if (original_bci >= original_index && original_bci < original_index + length) {
++        new_bci = original_bci - original_index + new_index;
++        break;
++      }
++    }
++    assert (new_bci != -1, "must have found new code section");
++
++  } else {
++    // We are in an original method.
++    new_bci = original_bci;
++  }
++
++  return new_bci;
++}
++
++
+ int methodOopDesc::extra_stack_words() {
+   // not an inline function, to avoid a header dependency on Interpreter
+   return extra_stack_entries() * Interpreter::stackElementSize;
+@@ -1061,6 +1125,9 @@ methodHandle methodOopDesc::clone_with_new_data(methodHandle m, u_char* new_code
+ 
+   // Reset correct method/const method, method size, and parameter info
+   newm->set_constMethod(newcm);
++  newm->set_forward_method(newm->forward_method());
++  newm->set_new_version(newm->new_version());
++  newm->set_old_version(newm->old_version());
+   newm->constMethod()->set_code_size(new_code_length);
+   newm->constMethod()->set_constMethod_size(new_const_method_size);
+   newm->set_method_size(new_method_size);
+diff --git a/src/share/vm/oops/methodOop.hpp b/src/share/vm/oops/methodOop.hpp
+index 486e106..11e52bb 100644
+--- a/src/share/vm/oops/methodOop.hpp
++++ b/src/share/vm/oops/methodOop.hpp
+@@ -114,6 +114,11 @@ class methodOopDesc : public oopDesc {
+   AccessFlags       _access_flags;               // Access flags
+   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
+                                                  // note: can have vtables with >2**16 elements (because of inheritance)
++  // (tw) Newer version of method available?
++  methodOop         _forward_method;
++  methodOop         _new_version;
++  methodOop         _old_version;
++
+ #ifdef CC_INTERP
+   int               _result_index;               // C++ interpreter needs for converting results to/from stack
+ #endif
+@@ -175,6 +180,32 @@ class methodOopDesc : public oopDesc {
+   int name_index() const                         { return constMethod()->name_index();         }
+   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
+ 
++  methodOop forward_method() const {return _forward_method; }
++  void set_forward_method(methodOop m) { _forward_method = m; }
++  bool has_forward_method() const { return forward_method() != NULL; }
++  methodOop new_version() const {return _new_version; }
++  void set_new_version(methodOop m) { _new_version = m; }
++  methodOop newest_version() { if(_new_version == NULL) return this; else return new_version()->newest_version(); }
++
++  methodOop old_version() const {return _old_version; };
++  void set_old_version(methodOop m) {
++    if (m == NULL) {
++      _old_version = NULL;
++      return;
++    }
++
++    assert(_old_version == NULL, "may only be set once");
++    assert(this->code_size() == m->code_size(), "must have same code length");
++    _old_version = m;
++  }
++
++  methodOop oldest_version() const { 
++    if(_old_version == NULL) return (methodOop)this;
++    else {
++      return old_version()->oldest_version();
++    }
++  }
++
+   // signature
+   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
+   int signature_index() const                    { return constMethod()->signature_index();         }
+@@ -670,6 +701,10 @@ class methodOopDesc : public oopDesc {
+   // Inline cache support
+   void cleanup_inline_caches();
+ 
++  // (tw) Method forwarding support.
++  bool is_in_code_section(int bci);
++  int calculate_forward_bci(int bci, methodOop new_method);
++
+   // Find if klass for method is loaded
+   bool is_klass_loaded_by_klass_index(int klass_index) const;
+   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
+@@ -734,6 +769,9 @@ class methodOopDesc : public oopDesc {
+ 
+   // Garbage collection support
+   oop*  adr_constMethod() const                  { return (oop*)&_constMethod;     }
++  oop*  adr_forward_method() const               { return (oop*)&_forward_method;  }
++  oop*  adr_new_version() const                  { return (oop*)&_new_version;     }
++  oop*  adr_old_version() const                  { return (oop*)&_old_version;     }
+   oop*  adr_method_data() const                  { return (oop*)&_method_data;     }
+ };
+ 
+diff --git a/src/share/vm/oops/oop.hpp b/src/share/vm/oops/oop.hpp
+index 5982c88..4873fca 100644
+--- a/src/share/vm/oops/oop.hpp
++++ b/src/share/vm/oops/oop.hpp
+@@ -95,6 +95,7 @@ class oopDesc {
+   narrowOop* compressed_klass_addr();
+ 
+   void set_klass(klassOop k);
++  void set_klass_no_check(klassOop k);
+ 
+   // For klass field compression
+   int klass_gap() const;
+@@ -135,6 +136,7 @@ class oopDesc {
+   bool is_array()              const;
+   bool is_objArray()           const;
+   bool is_klass()              const;
++  bool is_instanceKlass()      const;
+   bool is_thread()             const;
+   bool is_method()             const;
+   bool is_constMethod()        const;
+diff --git a/src/share/vm/oops/oop.inline.hpp b/src/share/vm/oops/oop.inline.hpp
+index f4eb2f7..0acb346 100644
+--- a/src/share/vm/oops/oop.inline.hpp
++++ b/src/share/vm/oops/oop.inline.hpp
+@@ -123,6 +123,14 @@ inline void oopDesc::set_klass(klassOop k) {
+   }
+ }
+ 
++inline void oopDesc::set_klass_no_check(klassOop k) {
++  if (UseCompressedOops) {
++    oop_store_without_check(compressed_klass_addr(), (oop)k);
++  } else {
++    oop_store_without_check(klass_addr(), (oop) k);
++  }
++}
++
+ inline int oopDesc::klass_gap() const {
+   return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
+ }
+@@ -156,6 +164,7 @@ inline bool oopDesc::is_objArray()           const { return blueprint()->oop_is_
+ inline bool oopDesc::is_typeArray()          const { return blueprint()->oop_is_typeArray(); }
+ inline bool oopDesc::is_javaArray()          const { return blueprint()->oop_is_javaArray(); }
+ inline bool oopDesc::is_klass()              const { return blueprint()->oop_is_klass(); }
++inline bool oopDesc::is_instanceKlass()      const { return blueprint()->oop_is_instanceKlass(); }
+ inline bool oopDesc::is_thread()             const { return blueprint()->oop_is_thread(); }
+ inline bool oopDesc::is_method()             const { return blueprint()->oop_is_method(); }
+ inline bool oopDesc::is_constMethod()        const { return blueprint()->oop_is_constMethod(); }
+diff --git a/src/share/vm/prims/jni.cpp b/src/share/vm/prims/jni.cpp
+index 8d82439..0e95b14 100644
+--- a/src/share/vm/prims/jni.cpp
++++ b/src/share/vm/prims/jni.cpp
+@@ -406,7 +406,7 @@ JNI_ENTRY(jclass, jni_DefineClass(JNIEnv *env, const char *name, jobject loaderR
+     }
+   }
+   klassOop k = SystemDictionary::resolve_from_stream(class_name, class_loader,
+-                                                     Handle(), &st, true,
++                                                     Handle(), &st, true, KlassHandle(),
+                                                      CHECK_NULL);
+ 
+   if (TraceClassResolution && k != NULL) {
+diff --git a/src/share/vm/prims/jvm.cpp b/src/share/vm/prims/jvm.cpp
+index 839c11f..a82f450 100644
+--- a/src/share/vm/prims/jvm.cpp
++++ b/src/share/vm/prims/jvm.cpp
+@@ -909,7 +909,7 @@ static jclass jvm_define_class_common(JNIEnv *env, const char *name,
+   Handle protection_domain (THREAD, JNIHandles::resolve(pd));
+   klassOop k = SystemDictionary::resolve_from_stream(class_name, class_loader,
+                                                      protection_domain, &st,
+-                                                     verify != 0,
++                                                     verify != 0, KlassHandle(),
+                                                      CHECK_NULL);
+ 
+   if (TraceClassResolution && k != NULL) {
+diff --git a/src/share/vm/prims/jvmtiEnv.cpp b/src/share/vm/prims/jvmtiEnv.cpp
+index 4ac6b82..30b8e84 100644
+--- a/src/share/vm/prims/jvmtiEnv.cpp
++++ b/src/share/vm/prims/jvmtiEnv.cpp
+@@ -290,7 +290,10 @@ JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
+     class_definitions[index].klass              = jcls;
+   }
+   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
+-  VMThread::execute(&op);
++  {
++    MutexLocker sd_mutex(RedefineClasses_lock);
++    VMThread::execute(&op);
++  }
+   return (op.check_error());
+ } /* end RetransformClasses */
+ 
+@@ -299,9 +302,12 @@ JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
+ // class_definitions - pre-checked for NULL
+ jvmtiError
+ JvmtiEnv::RedefineClasses(jint class_count, const jvmtiClassDefinition* class_definitions) {
+-//TODO: add locking
++
+   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_redefine);
+-  VMThread::execute(&op);
++  {
++    MutexLocker sd_mutex(RedefineClasses_lock);
++    VMThread::execute(&op);
++  }
+   return (op.check_error());
+ } /* end RedefineClasses */
+ 
+diff --git a/src/share/vm/prims/jvmtiExport.cpp b/src/share/vm/prims/jvmtiExport.cpp
+index ec8ede3..2bd5983 100644
+--- a/src/share/vm/prims/jvmtiExport.cpp
++++ b/src/share/vm/prims/jvmtiExport.cpp
+@@ -2296,7 +2296,7 @@ JvmtiDynamicCodeEventCollector::JvmtiDynamicCodeEventCollector() : _code_blobs(N
+ // iterate over any code blob descriptors collected and post a
+ // DYNAMIC_CODE_GENERATED event to the profiler.
+ JvmtiDynamicCodeEventCollector::~JvmtiDynamicCodeEventCollector() {
+-  assert(!JavaThread::current()->owns_locks(), "all locks must be released to post deferred events");
++  assert(!JavaThread::current()->owns_locks_but_redefine_classes_lock(), "all locks must be released to post deferred events");
+  // iterate over any code blob descriptors that we collected
+  if (_code_blobs != NULL) {
+    for (int i=0; i<_code_blobs->length(); i++) {
+diff --git a/src/share/vm/prims/jvmtiImpl.cpp b/src/share/vm/prims/jvmtiImpl.cpp
+index d3fa140..f4f8b57 100644
+--- a/src/share/vm/prims/jvmtiImpl.cpp
++++ b/src/share/vm/prims/jvmtiImpl.cpp
+@@ -286,6 +286,8 @@ address JvmtiBreakpoint::getBcp() {
+ void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
+   ((methodOopDesc*)_method->*meth_act)(_bci);
+ 
++  // DCEVM: TODO: Check how we can implement this differently here!
++
+   // add/remove breakpoint to/from versions of the method that
+   // are EMCP. Directly or transitively obsolete methods are
+   // not saved in the PreviousVersionInfo.
+diff --git a/src/share/vm/prims/jvmtiRedefineClasses.cpp b/src/share/vm/prims/jvmtiRedefineClasses.cpp
+index 606be1c..ef4f380 100644
+--- a/src/share/vm/prims/jvmtiRedefineClasses.cpp
++++ b/src/share/vm/prims/jvmtiRedefineClasses.cpp
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
++ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+  *
+  * This code is free software; you can redistribute it and/or modify it
+@@ -30,581 +30,637 @@
+ #include "interpreter/rewriter.hpp"
+ #include "memory/gcLocker.hpp"
+ #include "memory/universe.inline.hpp"
+-#include "oops/fieldStreams.hpp"
++#include "memory/cardTableRS.hpp"
+ #include "oops/klassVtable.hpp"
++#include "oops/fieldStreams.hpp"
+ #include "prims/jvmtiImpl.hpp"
+ #include "prims/jvmtiRedefineClasses.hpp"
++#include "prims/jvmtiClassFileReconstituter.hpp"
+ #include "prims/methodComparator.hpp"
+-#include "prims/methodHandles.hpp"
+ #include "runtime/deoptimization.hpp"
+ #include "runtime/relocator.hpp"
+ #include "utilities/bitMap.inline.hpp"
++#include "compiler/compileBroker.hpp"
+ 
+ 
+ objArrayOop VM_RedefineClasses::_old_methods = NULL;
+ objArrayOop VM_RedefineClasses::_new_methods = NULL;
+-methodOop*  VM_RedefineClasses::_matching_old_methods = NULL;
+-methodOop*  VM_RedefineClasses::_matching_new_methods = NULL;
+-methodOop*  VM_RedefineClasses::_deleted_methods      = NULL;
+-methodOop*  VM_RedefineClasses::_added_methods        = NULL;
++int*        VM_RedefineClasses::_matching_old_methods = NULL;
++int*        VM_RedefineClasses::_matching_new_methods = NULL;
++int*        VM_RedefineClasses::_deleted_methods      = NULL;
++int*        VM_RedefineClasses::_added_methods        = NULL;
+ int         VM_RedefineClasses::_matching_methods_length = 0;
+ int         VM_RedefineClasses::_deleted_methods_length  = 0;
+ int         VM_RedefineClasses::_added_methods_length    = 0;
+ klassOop    VM_RedefineClasses::_the_class_oop = NULL;
+ 
++// Holds the revision number of the current class redefinition
++int    VM_RedefineClasses::_revision_number = -1;
+ 
+-VM_RedefineClasses::VM_RedefineClasses(jint class_count,
+-                                       const jvmtiClassDefinition *class_defs,
+-                                       JvmtiClassLoadKind class_load_kind) {
++VM_RedefineClasses::VM_RedefineClasses(jint class_count, const jvmtiClassDefinition *class_defs, JvmtiClassLoadKind class_load_kind)
++   : VM_GC_Operation(Universe::heap()->total_full_collections(), GCCause::_jvmti_force_gc) {
++  RC_TIMER_START(_timer_total);
+   _class_count = class_count;
+   _class_defs = class_defs;
+   _class_load_kind = class_load_kind;
+-  _res = JVMTI_ERROR_NONE;
++  _updated_oops = NULL;
++  _result = JVMTI_ERROR_NONE;
+ }
+ 
+-bool VM_RedefineClasses::doit_prologue() {
+-  if (_class_count == 0) {
+-    _res = JVMTI_ERROR_NONE;
+-    return false;
++VM_RedefineClasses::~VM_RedefineClasses() {
++  {
++    MonitorLockerEx ml(RedefinitionSync_lock);
++    Threads::set_wait_at_instrumentation_entry(false);
++    ml.notify_all();
++  }
++
++  unlock_threads();
++  RC_TIMER_STOP(_timer_total);
++
++  if (TimeRedefineClasses) {
++    tty->print_cr("Timing Prologue:             %d", _timer_prologue.milliseconds());
++    tty->print_cr("Timing Class Loading:        %d", _timer_class_loading.milliseconds());
++    tty->print_cr("Timing Waiting for Lock:     %d", _timer_wait_for_locks.milliseconds());
++    tty->print_cr("Timing Class Linking:        %d", _timer_class_linking.milliseconds());
++    tty->print_cr("Timing Check Type:           %d", _timer_check_type.milliseconds());
++    tty->print_cr("Timing Prepare Redefinition: %d", _timer_prepare_redefinition.milliseconds());
++    tty->print_cr("Timing Redefinition GC:      %d", _timer_redefinition.milliseconds());
++    tty->print_cr("Timing Epilogue:             %d", _timer_vm_op_epilogue.milliseconds());
++    tty->print_cr("------------------------------------------------------------------");
++    tty->print_cr("Total Time:                  %d", _timer_total.milliseconds());
+   }
+-  if (_class_defs == NULL) {
+-    _res = JVMTI_ERROR_NULL_POINTER;
+-    return false;
++}
++
++// Searches for all affected classes and performs a sorting such that a supertype is always before a subtype.
++jvmtiError VM_RedefineClasses::find_sorted_affected_classes(GrowableArray<instanceKlassHandle> *all_affected_klasses) {
++
++  // Create array with all classes for which the redefine command was given
++  GrowableArray<instanceKlassHandle> klasses_to_redefine;
++  for (int i=0; i<_class_count; i++) {
++    oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
++    instanceKlassHandle klass_handle(Thread::current(), java_lang_Class::as_klassOop(mirror));
++    klasses_to_redefine.append(klass_handle);
++    assert(klass_handle->new_version() == NULL, "Must be new class");
+   }
+-  for (int i = 0; i < _class_count; i++) {
+-    if (_class_defs[i].klass == NULL) {
+-      _res = JVMTI_ERROR_INVALID_CLASS;
+-      return false;
+-    }
+-    if (_class_defs[i].class_byte_count == 0) {
+-      _res = JVMTI_ERROR_INVALID_CLASS_FORMAT;
+-      return false;
+-    }
+-    if (_class_defs[i].class_bytes == NULL) {
+-      _res = JVMTI_ERROR_NULL_POINTER;
+-      return false;
++
++  // Find classes not directly redefined, but affected by a redefinition (because one of its supertypes is redefined)
++  GrowableArray<instanceKlassHandle> affected_classes;
++  FindAffectedKlassesClosure closure(&klasses_to_redefine, &affected_classes);
++
++  // Trace affected classes
++  if (RC_TRACE_ENABLED(0x00000001)) {
++    RC_TRACE(0x00000001, ("Klasses affected: %d",
++      affected_classes.length()));
++    for (int i=0; i<affected_classes.length(); i++) {
++      RC_TRACE(0x00000001, ("%s",
++        affected_classes.at(i)->name()->as_C_string()));
+     }
+   }
+ 
+-  // Start timer after all the sanity checks; not quite accurate, but
+-  // better than adding a bunch of stop() calls.
+-  RC_TIMER_START(_timer_vm_op_prologue);
++  // Add the array of affected classes and the array of redefined classes to get a list of all classes that need a redefinition
++  all_affected_klasses->appendAll(&klasses_to_redefine);
++  all_affected_klasses->appendAll(&affected_classes);
+ 
+-  // We first load new class versions in the prologue, because somewhere down the
+-  // call chain it is required that the current thread is a Java thread.
+-  _res = load_new_class_versions(Thread::current());
+-  if (_res != JVMTI_ERROR_NONE) {
+-    // Free os::malloc allocated memory in load_new_class_version.
+-    os::free(_scratch_classes);
+-    RC_TIMER_STOP(_timer_vm_op_prologue);
+-    return false;
++  // Sort the affected klasses such that a supertype is always on a smaller array index than its subtype.
++  jvmtiError result = do_topological_class_sorting(_class_defs, _class_count, &affected_classes, all_affected_klasses, Thread::current());
++  if (RC_TRACE_ENABLED(0x00000001)) {
++    RC_TRACE(0x00000001, ("Redefine order: "));
++    for (int i=0; i<all_affected_klasses->length(); i++) {
++      RC_TRACE(0x00000001, ("%s",
++        all_affected_klasses->at(i)->name()->as_C_string()));
++    }
+   }
+ 
+-  RC_TIMER_STOP(_timer_vm_op_prologue);
+-  return true;
++  return result;
+ }
+ 
+-void VM_RedefineClasses::doit() {
+-  Thread *thread = Thread::current();
++// Searches for the class bytes of the given class and returns them as a byte array.
++jvmtiError VM_RedefineClasses::find_class_bytes(instanceKlassHandle the_class, const unsigned char **class_bytes, jint *class_byte_count, jboolean *not_changed) {
+ 
+-  if (UseSharedSpaces) {
+-    // Sharing is enabled so we remap the shared readonly space to
+-    // shared readwrite, private just in case we need to redefine
+-    // a shared class. We do the remap during the doit() phase of
+-    // the safepoint to be safer.
+-    if (!CompactingPermGenGen::remap_shared_readonly_as_readwrite()) {
+-      RC_TRACE_WITH_THREAD(0x00000001, thread,
+-        ("failed to remap shared readonly space to readwrite, private"));
+-      _res = JVMTI_ERROR_INTERNAL;
+-      return;
++  *not_changed = false;
++
++  // Search for the index in the redefinition array that corresponds to the current class
++  int j;
++  for (j=0; j<_class_count; j++) {
++    oop mirror = JNIHandles::resolve_non_null(_class_defs[j].klass);
++    klassOop the_class_oop = java_lang_Class::as_klassOop(mirror);
++    if (the_class_oop == the_class()) {
++      break;
+     }
+   }
+ 
+-  for (int i = 0; i < _class_count; i++) {
+-    redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread);
+-  }
+-  // Disable any dependent concurrent compilations
+-  SystemDictionary::notice_modification();
++  if (j == _class_count) {
+ 
+-  // Set flag indicating that some invariants are no longer true.
+-  // See jvmtiExport.hpp for detailed explanation.
+-  JvmtiExport::set_has_redefined_a_class();
++    *not_changed = true;
+ 
+-// check_class() is optionally called for product bits, but is
+-// always called for non-product bits.
+-#ifdef PRODUCT
+-  if (RC_TRACE_ENABLED(0x00004000)) {
+-#endif
+-    RC_TRACE_WITH_THREAD(0x00004000, thread, ("calling check_class"));
+-    SystemDictionary::classes_do(check_class, thread);
+-#ifdef PRODUCT
+-  }
+-#endif
+-}
++    // Redefine with same bytecodes. This is a class that is only indirectly affected by redefinition,
++    // so the user did not specify a different bytecode for that class.
+ 
+-void VM_RedefineClasses::doit_epilogue() {
+-  // Free os::malloc allocated memory.
+-  // The memory allocated in redefine will be free'ed in next VM operation.
+-  os::free(_scratch_classes);
+-
+-  if (RC_TRACE_ENABLED(0x00000004)) {
+-    // Used to have separate timers for "doit" and "all", but the timer
+-    // overhead skewed the measurements.
+-    jlong doit_time = _timer_rsc_phase1.milliseconds() +
+-                      _timer_rsc_phase2.milliseconds();
+-    jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time;
+-
+-    RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT
+-      "  prologue=" UINT64_FORMAT "  doit=" UINT64_FORMAT, all_time,
+-      _timer_vm_op_prologue.milliseconds(), doit_time));
+-    RC_TRACE(0x00000004,
+-      ("redefine_single_class: phase1=" UINT64_FORMAT "  phase2=" UINT64_FORMAT,
+-       _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds()));
++    if (the_class->get_cached_class_file_bytes() == NULL) {
++      // not cached, we need to reconstitute the class file from VM representation
++      constantPoolHandle  constants(Thread::current(), the_class->constants());
++      ObjectLocker ol(constants, Thread::current());    // lock constant pool while we query it
++
++      JvmtiClassFileReconstituter reconstituter(the_class);
++      if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
++        return reconstituter.get_error();
++      }
++
++      *class_byte_count = (jint)reconstituter.class_file_size();
++      *class_bytes      = (unsigned char*)reconstituter.class_file_bytes();
++
++    } else {
++
++      // it is cached, get it from the cache
++      *class_byte_count = the_class->get_cached_class_file_len();
++      *class_bytes      = the_class->get_cached_class_file_bytes();
++    }
++
++  } else {
++
++    // Redefine with bytecodes at index j
++    *class_bytes = _class_defs[j].class_bytes;
++    *class_byte_count = _class_defs[j].class_byte_count;
+   }
++
++  return JVMTI_ERROR_NONE;
+ }
+ 
+-bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) {
+-  // classes for primitives cannot be redefined
+-  if (java_lang_Class::is_primitive(klass_mirror)) {
++// Prologue of the VM operation, called on the Java thread in parallel to normal program execution
++bool VM_RedefineClasses::doit_prologue() {
++
++  _revision_number++;
++  RC_TRACE(0x00000001, ("Redefinition with revision number %d started!", _revision_number));
++
++  assert(Thread::current()->is_Java_thread(), "must be Java thread");
++  RC_TIMER_START(_timer_prologue);
++
++  if (!check_arguments()) {
++    RC_TIMER_STOP(_timer_prologue);
+     return false;
+   }
+-  klassOop the_class_oop = java_lang_Class::as_klassOop(klass_mirror);
+-  // classes for arrays cannot be redefined
+-  if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) {
++
++  // We first load new class versions in the prologue, because somewhere down the
++  // call chain it is required that the current thread is a Java thread.
++  _new_classes = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceKlassHandle>(5, true);
++  _result = load_new_class_versions(Thread::current());
++
++  RC_TRACE(0x00000001, ("Loaded new class versions!"));
++  if (_result != JVMTI_ERROR_NONE) {
++    RC_TRACE(0x00000001, ("error occured: %d!", _result));
++    delete _new_classes;
++    _new_classes = NULL;
++    RC_TIMER_STOP(_timer_prologue);
+     return false;
+   }
++
++  RC_TRACE(0x00000001, ("nearly finished"));
++  VM_GC_Operation::doit_prologue();
++  RC_TIMER_STOP(_timer_prologue);
++  RC_TRACE(0x00000001, ("doit_prologue finished!"));
+   return true;
+ }
+ 
+-// Append the current entry at scratch_i in scratch_cp to *merge_cp_p
+-// where the end of *merge_cp_p is specified by *merge_cp_length_p. For
+-// direct CP entries, there is just the current entry to append. For
+-// indirect and double-indirect CP entries, there are zero or more
+-// referenced CP entries along with the current entry to append.
+-// Indirect and double-indirect CP entries are handled by recursive
+-// calls to append_entry() as needed. The referenced CP entries are
+-// always appended to *merge_cp_p before the referee CP entry. These
+-// referenced CP entries may already exist in *merge_cp_p in which case
+-// there is nothing extra to append and only the current entry is
+-// appended.
+-void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp,
+-       int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p,
+-       TRAPS) {
+-
+-  // append is different depending on entry tag type
+-  switch (scratch_cp->tag_at(scratch_i).value()) {
+-
+-    // The old verifier is implemented outside the VM. It loads classes,
+-    // but does not resolve constant pool entries directly so we never
+-    // see Class entries here with the old verifier. Similarly the old
+-    // verifier does not like Class entries in the input constant pool.
+-    // The split-verifier is implemented in the VM so it can optionally
+-    // and directly resolve constant pool entries to load classes. The
+-    // split-verifier can accept either Class entries or UnresolvedClass
+-    // entries in the input constant pool. We revert the appended copy
+-    // back to UnresolvedClass so that either verifier will be happy
+-    // with the constant pool entry.
+-    case JVM_CONSTANT_Class:
+-    {
+-      // revert the copy to JVM_CONSTANT_UnresolvedClass
+-      (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p,
+-        scratch_cp->klass_name_at(scratch_i));
+-
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p)++;
+-    } break;
+-
+-    // these are direct CP entries so they can be directly appended,
+-    // but double and long take two constant pool entries
+-    case JVM_CONSTANT_Double:  // fall through
+-    case JVM_CONSTANT_Long:
+-    {
+-      constantPoolOopDesc::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
+-        THREAD);
+-
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p) += 2;
+-    } break;
+-
+-    // these are direct CP entries so they can be directly appended
+-    case JVM_CONSTANT_Float:   // fall through
+-    case JVM_CONSTANT_Integer: // fall through
+-    case JVM_CONSTANT_Utf8:    // fall through
+-
+-    // This was an indirect CP entry, but it has been changed into
+-    // an interned string so this entry can be directly appended.
+-    case JVM_CONSTANT_String:      // fall through
+-
+-    // These were indirect CP entries, but they have been changed into
+-    // Symbol*s so these entries can be directly appended.
+-    case JVM_CONSTANT_UnresolvedClass:  // fall through
+-    case JVM_CONSTANT_UnresolvedString:
+-    {
+-      constantPoolOopDesc::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
+-        THREAD);
++// Checks basic properties of the arguments of the redefinition command.
++bool VM_RedefineClasses::check_arguments() {
++
++  if (_class_count == 0) RC_ABORT(JVMTI_ERROR_NONE);
++  if (_class_defs == NULL) RC_ABORT(JVMTI_ERROR_NULL_POINTER);
++  for (int i = 0; i < _class_count; i++) {
++    if (_class_defs[i].klass == NULL) RC_ABORT(JVMTI_ERROR_INVALID_CLASS);
++    if (_class_defs[i].class_byte_count == 0) RC_ABORT(JVMTI_ERROR_INVALID_CLASS_FORMAT);
++    if (_class_defs[i].class_bytes == NULL) RC_ABORT(JVMTI_ERROR_NULL_POINTER);
++  }
++
++  return true;
++}
++
++jvmtiError VM_RedefineClasses::check_exception() const {
++  Thread* THREAD = Thread::current();
++  if (HAS_PENDING_EXCEPTION) {
++
++    Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
++    RC_TRACE(0x00000001, ("parse_stream exception: '%s'",
++      ex_name->as_C_string()));
++    if (TraceRedefineClasses >= 1) {
++      java_lang_Throwable::print(PENDING_EXCEPTION, tty);
++      tty->print_cr("");
++    }
++    CLEAR_PENDING_EXCEPTION;
++
++    if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
++      return JVMTI_ERROR_UNSUPPORTED_VERSION;
++    } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
++      return JVMTI_ERROR_INVALID_CLASS_FORMAT;
++    } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
++      return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
++    } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
++      // The message will be "XXX (wrong name: YYY)"
++      return JVMTI_ERROR_NAMES_DONT_MATCH;
++    } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
++      return JVMTI_ERROR_OUT_OF_MEMORY;
++    } else {
++      // Just in case more exceptions can be thrown..
++      return JVMTI_ERROR_FAILS_VERIFICATION;
++    }
++  }
++
++  return JVMTI_ERROR_NONE;
++}
++
++// Loads all new class versions and stores the instanceKlass handles in an array.
++jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
++
++  ResourceMark rm(THREAD);
++
++  RC_TRACE(0x00000001, ("==================================================================="));
++  RC_TRACE(0x00000001, ("load new class versions (%d)",
++    _class_count));
++
++  // Retrieve an array of all classes that need to be redefined
++  GrowableArray<instanceKlassHandle> all_affected_klasses;
++  jvmtiError err = find_sorted_affected_classes(&all_affected_klasses);
++  if (err != JVMTI_ERROR_NONE) {
++    RC_TRACE(0x00000001, ("Error finding sorted affected classes: %d",
++      (int)err));
++    return err;
++  }
++
++
++  JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
++
++  _max_redefinition_flags = Klass::NoRedefinition;
++  jvmtiError result = JVMTI_ERROR_NONE;
++
++  for (int i=0; i<all_affected_klasses.length(); i++) {
++    RC_TRACE(0x00000002, ("Processing affected class %d of %d",
++      i+1, all_affected_klasses.length()));
++
++    instanceKlassHandle the_class = all_affected_klasses.at(i);
++    RC_TRACE(0x00000002, ("name=%s",
++      the_class->name()->as_C_string()));
++
++    the_class->link_class(THREAD);
++    result = check_exception();
++    if (result != JVMTI_ERROR_NONE) break;
++
++    // Find new class bytes
++    const unsigned char* class_bytes;
++    jint class_byte_count;
++    jvmtiError error;
++    jboolean not_changed;
++    if ((error = find_class_bytes(the_class, &class_bytes, &class_byte_count, &not_changed)) != JVMTI_ERROR_NONE) {
++      RC_TRACE(0x00000001, ("Error finding class bytes: %d",
++        (int)error));
++      result = error;
++      break;
++    }
++    assert(class_bytes != NULL && class_byte_count != 0, "Class bytes defined at this point!");
++
++
++    // Set redefined class handle in JvmtiThreadState class.
++    // This redefined class is sent to agent event handler for class file
++    // load hook event.
++    state->set_class_being_redefined(&the_class, _class_load_kind);
++
++    RC_TRACE(0x00000002, ("Before resolving from stream"));
++
++    RC_TIMER_STOP(_timer_prologue);
++    RC_TIMER_START(_timer_class_loading);
++
++
++    // Parse the stream.
++    Handle the_class_loader(THREAD, the_class->class_loader());
++    Handle protection_domain(THREAD, the_class->protection_domain());
++    Symbol* the_class_sym = the_class->name();
++    ClassFileStream st((u1*) class_bytes, class_byte_count, (char *)"__VM_RedefineClasses__");
++    instanceKlassHandle new_class(THREAD, SystemDictionary::resolve_from_stream(the_class_sym,
++      the_class_loader,
++      protection_domain,
++      &st,
++      true,
++      the_class,
++      THREAD));
++
++    not_changed = false;
++
++    RC_TIMER_STOP(_timer_class_loading);
++    RC_TIMER_START(_timer_prologue);
++
++    RC_TRACE(0x00000002, ("After resolving class from stream!"));
++    // Clear class_being_redefined just to be sure.
++    state->clear_class_being_redefined();
++
++    result = check_exception();
++    if (result != JVMTI_ERROR_NONE) break;
++
++#ifdef ASSERT
++
++    assert(new_class() != NULL, "Class could not be loaded!");
++    assert(new_class() != the_class(), "must be different");
++    assert(new_class->new_version() == NULL && new_class->old_version() != NULL, "");
++
++
++    objArrayOop k_interfaces = new_class->local_interfaces();
++    for (int j=0; j<k_interfaces->length(); j++) {
++      assert(((klassOop)k_interfaces->obj_at(j))->klass_part()->is_newest_version(), "just checking");
++    }
++
++    if (!THREAD->is_Compiler_thread()) {
++
++      RC_TRACE(0x00000002, ("name=%s loader="INTPTR_FORMAT" protection_domain="INTPTR_FORMAT" ",
++        the_class->name()->as_C_string(),
++        (address)(the_class->class_loader()),
++        (address)(the_class->protection_domain())));
++      // If we are on the compiler thread, we must not try to resolve a class.
++      klassOop systemLookup = SystemDictionary::resolve_or_null(the_class->name(), the_class->class_loader(), the_class->protection_domain(), THREAD);
++      
++      if (systemLookup != NULL) {
++        assert(systemLookup == new_class->old_version(), "Old class must be in system dictionary!");
++      
++
++        Klass *subklass = new_class()->klass_part()->subklass();
++        while (subklass != NULL) {
++          assert(subklass->new_version() == NULL, "Most recent version of class!");
++          subklass = subklass->next_sibling();
++        }
++      } else {
++        // This can happen for reflection generated classes.. ?
++        CLEAR_PENDING_EXCEPTION;
++      }
++    }
+ 
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
++#endif
++
++    if (RC_TRACE_ENABLED(0x00000001)) {
++      if (new_class->layout_helper() != the_class->layout_helper()) {
++        RC_TRACE(0x00000001, ("Instance size change for class %s: new=%d old=%d",
++         new_class->name()->as_C_string(),
++         new_class->layout_helper(),
++         the_class->layout_helper()));
+       }
+-      (*merge_cp_length_p)++;
+-    } break;
++    }
+ 
+-    // this is an indirect CP entry so it needs special handling
+-    case JVM_CONSTANT_NameAndType:
+-    {
+-      int name_ref_i = scratch_cp->name_ref_index_at(scratch_i);
+-      int new_name_ref_i = find_or_append_indirect_entry(scratch_cp, name_ref_i, merge_cp_p,
+-                                                         merge_cp_length_p, THREAD);
+-
+-      int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i);
+-      int new_signature_ref_i = find_or_append_indirect_entry(scratch_cp, signature_ref_i,
+-                                                              merge_cp_p, merge_cp_length_p,
+-                                                              THREAD);
+-
+-      // If the referenced entries already exist in *merge_cp_p, then
+-      // both new_name_ref_i and new_signature_ref_i will both be 0.
+-      // In that case, all we are appending is the current entry.
+-      if (new_name_ref_i != name_ref_i) {
+-        RC_TRACE(0x00080000,
+-          ("NameAndType entry@%d name_ref_index change: %d to %d",
+-          *merge_cp_length_p, name_ref_i, new_name_ref_i));
+-      }
+-      if (new_signature_ref_i != signature_ref_i) {
+-        RC_TRACE(0x00080000,
+-          ("NameAndType entry@%d signature_ref_index change: %d to %d",
+-          *merge_cp_length_p, signature_ref_i, new_signature_ref_i));
+-      }
+-
+-      (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p,
+-        new_name_ref_i, new_signature_ref_i);
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p)++;
+-    } break;
+-
+-    // this is a double-indirect CP entry so it needs special handling
+-    case JVM_CONSTANT_Fieldref:           // fall through
+-    case JVM_CONSTANT_InterfaceMethodref: // fall through
+-    case JVM_CONSTANT_Methodref:
+-    {
+-      int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i);
+-      int new_klass_ref_i = find_or_append_indirect_entry(scratch_cp, klass_ref_i,
+-                                                          merge_cp_p, merge_cp_length_p, THREAD);
+-      int name_and_type_ref_i = scratch_cp->uncached_name_and_type_ref_index_at(scratch_i);
+-      int new_name_and_type_ref_i = find_or_append_indirect_entry(scratch_cp, name_and_type_ref_i,
+-                                                          merge_cp_p, merge_cp_length_p, THREAD);
+-
+-      const char *entry_name;
+-      switch (scratch_cp->tag_at(scratch_i).value()) {
+-      case JVM_CONSTANT_Fieldref:
+-        entry_name = "Fieldref";
+-        (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i,
+-          new_name_and_type_ref_i);
+-        break;
+-      case JVM_CONSTANT_InterfaceMethodref:
+-        entry_name = "IFMethodref";
+-        (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p,
+-          new_klass_ref_i, new_name_and_type_ref_i);
+-        break;
+-      case JVM_CONSTANT_Methodref:
+-        entry_name = "Methodref";
+-        (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i,
+-          new_name_and_type_ref_i);
+-        break;
+-      default:
+-        guarantee(false, "bad switch");
++    // Set the new version of the class
++    new_class->set_revision_number(_revision_number);
++    new_class->set_redefinition_index(i);
++    the_class->set_new_version(new_class());
++    _new_classes->append(new_class);
++
++    assert(new_class->new_version() == NULL, "");
++
++    int redefinition_flags = Klass::NoRedefinition;
++
++    if (not_changed) {
++      redefinition_flags = Klass::NoRedefinition;
++    } else if (AllowAdvancedClassRedefinition) {
++      redefinition_flags = calculate_redefinition_flags(new_class);
++    } else {
++      jvmtiError allowed = check_redefinition_allowed(new_class);
++      if (allowed != JVMTI_ERROR_NONE) {
++        RC_TRACE(0x00000001, ("Error redefinition not allowed!"));
++        result = allowed;
+         break;
+       }
++      redefinition_flags = Klass::ModifyClass;
++    }
++
++    if (new_class->super() != NULL) {
++      redefinition_flags = redefinition_flags | new_class->super()->klass_part()->redefinition_flags();
++    }
++
++    for (int j=0; j<new_class->local_interfaces()->length(); j++) {
++      redefinition_flags = redefinition_flags | ((klassOop)new_class->local_interfaces()->obj_at(j))->klass_part()->redefinition_flags();
++    }
++
++    new_class->set_redefinition_flags(redefinition_flags);
+ 
+-      if (klass_ref_i != new_klass_ref_i) {
+-        RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d",
+-          entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i));
++    _max_redefinition_flags = _max_redefinition_flags | redefinition_flags;
++
++    if ((redefinition_flags & Klass::ModifyInstances) != 0) {
++      // TODO: Check if watch access flags of static fields are updated correctly.
++      calculate_instance_update_information(_new_classes->at(i)());
++    } else {
++      assert(new_class->layout_helper() >> 1 == new_class->old_version()->klass_part()->layout_helper() >> 1, "must be equal");
++      assert(new_class->fields()->length() == ((instanceKlass*)new_class->old_version()->klass_part())->fields()->length(), "must be equal");
++
++      fieldDescriptor fd_new;
++      fieldDescriptor fd_old;
++      for (JavaFieldStream fs(new_class); !fs.done(); fs.next()) {
++        fd_new.initialize(new_class(), fs.index());
++        fd_old.initialize(new_class->old_version(), fs.index());
++        transfer_special_access_flags(&fd_old, &fd_new);
+       }
+-      if (name_and_type_ref_i != new_name_and_type_ref_i) {
+-        RC_TRACE(0x00080000,
+-          ("%s entry@%d name_and_type_index changed: %d to %d",
+-          entry_name, *merge_cp_length_p, name_and_type_ref_i,
+-          new_name_and_type_ref_i));
++    }
++
++    if (RC_TRACE_ENABLED(0x00000008)) {
++      if (new_class->super() != NULL) {
++        RC_TRACE(0x00000008, ("Super class is %s",
++          new_class->super()->klass_part()->name()->as_C_string()));
+       }
++    }
++
++#ifdef ASSERT
++    assert(new_class->super() == NULL || new_class->super()->klass_part()->new_version() == NULL, "Super klass must be newest version!");
++
++    the_class->vtable()->verify(tty);
++    new_class->vtable()->verify(tty);
++#endif
++
++    RC_TRACE(0x00000002, ("Verification done!"));
++
++    if (i == all_affected_klasses.length() - 1) {
+ 
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
++      // This was the last class processed => check if additional classes have been loaded in the meantime
++
++      RC_TIMER_STOP(_timer_prologue);
++      lock_threads();
++      RC_TIMER_START(_timer_prologue);
++
++      for (int j=0; j<all_affected_klasses.length(); j++) {
++
++        klassOop initial_klass = all_affected_klasses.at(j)();
++        Klass *initial_subklass = initial_klass->klass_part()->subklass();
++        Klass *cur_klass = initial_subklass;
++        while(cur_klass != NULL) {
++
++          if(cur_klass->oop_is_instance() && cur_klass->is_newest_version()) {
++            instanceKlassHandle handle(THREAD, cur_klass->as_klassOop());
++            if (!all_affected_klasses.contains(handle)) {
++
++              int k = i + 1;
++              for (; k<all_affected_klasses.length(); k++) {
++                if (all_affected_klasses.at(k)->is_subtype_of(cur_klass->as_klassOop())) {
++                  break;
++                }
++              }
++              all_affected_klasses.insert_before(k, handle);
++              RC_TRACE(0x00000002, ("Adding newly loaded class to affected classes: %s",
++                cur_klass->name()->as_C_string()));
++            }
++          }
++
++          cur_klass = cur_klass->next_sibling();
++        }
+       }
+-      (*merge_cp_length_p)++;
+-    } break;
+ 
+-    // this is an indirect CP entry so it needs special handling
+-    case JVM_CONSTANT_MethodType:
+-    {
+-      int ref_i = scratch_cp->method_type_index_at(scratch_i);
+-      int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
+-                                                    merge_cp_length_p, THREAD);
+-      if (new_ref_i != ref_i) {
+-        RC_TRACE(0x00080000,
+-                 ("MethodType entry@%d ref_index change: %d to %d",
+-                  *merge_cp_length_p, ref_i, new_ref_i));
+-      }
+-      (*merge_cp_p)->method_type_index_at_put(*merge_cp_length_p, new_ref_i);
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p)++;
+-    } break;
+-
+-    // this is an indirect CP entry so it needs special handling
+-    case JVM_CONSTANT_MethodHandle:
+-    {
+-      int ref_kind = scratch_cp->method_handle_ref_kind_at(scratch_i);
+-      int ref_i = scratch_cp->method_handle_index_at(scratch_i);
+-      int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
+-                                                    merge_cp_length_p, THREAD);
+-      if (new_ref_i != ref_i) {
+-        RC_TRACE(0x00080000,
+-                 ("MethodHandle entry@%d ref_index change: %d to %d",
+-                  *merge_cp_length_p, ref_i, new_ref_i));
+-      }
+-      (*merge_cp_p)->method_handle_index_at_put(*merge_cp_length_p, ref_kind, new_ref_i);
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p)++;
+-    } break;
+-
+-    // this is an indirect CP entry so it needs special handling
+-    case JVM_CONSTANT_InvokeDynamic:
+-    {
+-      // Index of the bootstrap specifier in the operands array
+-      int old_bs_i = scratch_cp->invoke_dynamic_bootstrap_specifier_index(scratch_i);
+-      int new_bs_i = find_or_append_operand(scratch_cp, old_bs_i, merge_cp_p,
+-                                                    merge_cp_length_p, THREAD);
+-      // The bootstrap method NameAndType_info index
+-      int old_ref_i = scratch_cp->invoke_dynamic_name_and_type_ref_index_at(scratch_i);
+-      int new_ref_i = find_or_append_indirect_entry(scratch_cp, old_ref_i, merge_cp_p,
+-                                                    merge_cp_length_p, THREAD);
+-      if (new_bs_i != old_bs_i) {
+-        RC_TRACE(0x00080000,
+-                 ("InvokeDynamic entry@%d bootstrap_method_attr_index change: %d to %d",
+-                  *merge_cp_length_p, old_bs_i, new_bs_i));
+-      }
+-      if (new_ref_i != old_ref_i) {
+-        RC_TRACE(0x00080000,
+-                 ("InvokeDynamic entry@%d name_and_type_index change: %d to %d",
+-                  *merge_cp_length_p, old_ref_i, new_ref_i));
+-      }
+-
+-      (*merge_cp_p)->invoke_dynamic_at_put(*merge_cp_length_p, new_bs_i, new_ref_i);
+-      if (scratch_i != *merge_cp_length_p) {
+-        // The new entry in *merge_cp_p is at a different index than
+-        // the new entry in scratch_cp so we need to map the index values.
+-        map_index(scratch_cp, scratch_i, *merge_cp_length_p);
+-      }
+-      (*merge_cp_length_p)++;
+-    } break;
+-
+-   // At this stage, Class or UnresolvedClass could be here, but not
+-    // ClassIndex
+-    case JVM_CONSTANT_ClassIndex: // fall through
+-
+-    // Invalid is used as the tag for the second constant pool entry
+-    // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
+-    // not be seen by itself.
+-    case JVM_CONSTANT_Invalid: // fall through
+-
+-    // At this stage, String or UnresolvedString could be here, but not
+-    // StringIndex
+-    case JVM_CONSTANT_StringIndex: // fall through
+-
+-    // At this stage JVM_CONSTANT_UnresolvedClassInError should not be
+-    // here
+-    case JVM_CONSTANT_UnresolvedClassInError: // fall through
++      int new_count = all_affected_klasses.length() - 1 - i;
++      if (new_count != 0) {
+ 
+-    default:
+-    {
+-      // leave a breadcrumb
+-      jbyte bad_value = scratch_cp->tag_at(scratch_i).value();
+-      ShouldNotReachHere();
+-    } break;
+-  } // end switch tag value
+-} // end append_entry()
+-
+-
+-int VM_RedefineClasses::find_or_append_indirect_entry(constantPoolHandle scratch_cp,
+-      int ref_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
+-
+-  int new_ref_i = ref_i;
+-  bool match = (ref_i < *merge_cp_length_p) &&
+-               scratch_cp->compare_entry_to(ref_i, *merge_cp_p, ref_i, THREAD);
+-
+-  if (!match) {
+-    // forward reference in *merge_cp_p or not a direct match
+-    int found_i = scratch_cp->find_matching_entry(ref_i, *merge_cp_p, THREAD);
+-    if (found_i != 0) {
+-      guarantee(found_i != ref_i, "compare_entry_to() and find_matching_entry() do not agree");
+-      // Found a matching entry somewhere else in *merge_cp_p so just need a mapping entry.
+-      new_ref_i = found_i;
+-      map_index(scratch_cp, ref_i, found_i);
+-    } else {
+-      // no match found so we have to append this entry to *merge_cp_p
+-      append_entry(scratch_cp, ref_i, merge_cp_p, merge_cp_length_p, THREAD);
+-      // The above call to append_entry() can only append one entry
+-      // so the post call query of *merge_cp_length_p is only for
+-      // the sake of consistency.
+-      new_ref_i = *merge_cp_length_p - 1;
+-    }
+-  }
+-
+-  return new_ref_i;
+-} // end find_or_append_indirect_entry()
+-
+-
+-// Append a bootstrap specifier into the merge_cp operands that is semantically equal
+-// to the scratch_cp operands bootstrap specifier passed by the old_bs_i index.
+-// Recursively append new merge_cp entries referenced by the new bootstrap specifier.
+-void VM_RedefineClasses::append_operand(constantPoolHandle scratch_cp, int old_bs_i,
+-       constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
+-
+-  int old_ref_i = scratch_cp->operand_bootstrap_method_ref_index_at(old_bs_i);
+-  int new_ref_i = find_or_append_indirect_entry(scratch_cp, old_ref_i, merge_cp_p,
+-                                                merge_cp_length_p, THREAD);
+-  if (new_ref_i != old_ref_i) {
+-    RC_TRACE(0x00080000,
+-             ("operands entry@%d bootstrap method ref_index change: %d to %d",
+-              _operands_cur_length, old_ref_i, new_ref_i));
+-  }
+-
+-  typeArrayOop merge_ops = (*merge_cp_p)->operands();
+-  int new_bs_i = _operands_cur_length;
+-  // We have _operands_cur_length == 0 when the merge_cp operands is empty yet.
+-  // However, the operand_offset_at(0) was set in the extend_operands() call.
+-  int new_base = (new_bs_i == 0) ? (*merge_cp_p)->operand_offset_at(0)
+-                                 : (*merge_cp_p)->operand_next_offset_at(new_bs_i - 1);
+-  int argc     = scratch_cp->operand_argument_count_at(old_bs_i);
+-
+-  constantPoolOopDesc::operand_offset_at_put(merge_ops, _operands_cur_length, new_base);
+-  merge_ops->short_at_put(new_base++, new_ref_i);
+-  merge_ops->short_at_put(new_base++, argc);
+-
+-  for (int i = 0; i < argc; i++) {
+-    int old_arg_ref_i = scratch_cp->operand_argument_index_at(old_bs_i, i);
+-    int new_arg_ref_i = find_or_append_indirect_entry(scratch_cp, old_arg_ref_i, merge_cp_p,
+-                                                      merge_cp_length_p, THREAD);
+-    merge_ops->short_at_put(new_base++, new_arg_ref_i);
+-    if (new_arg_ref_i != old_arg_ref_i) {
+-      RC_TRACE(0x00080000,
+-               ("operands entry@%d bootstrap method argument ref_index change: %d to %d",
+-                _operands_cur_length, old_arg_ref_i, new_arg_ref_i));
+-    }
+-  }
+-  if (old_bs_i != _operands_cur_length) {
+-    // The bootstrap specifier in *merge_cp_p is at a different index than
+-    // that in scratch_cp so we need to map the index values.
+-    map_operand_index(old_bs_i, new_bs_i);
+-  }
+-  _operands_cur_length++;
+-} // end append_operand()
+-
+-
+-int VM_RedefineClasses::find_or_append_operand(constantPoolHandle scratch_cp,
+-      int old_bs_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
+-
+-  int new_bs_i = old_bs_i; // bootstrap specifier index
+-  bool match = (old_bs_i < _operands_cur_length) &&
+-               scratch_cp->compare_operand_to(old_bs_i, *merge_cp_p, old_bs_i, THREAD);
+-
+-  if (!match) {
+-    // forward reference in *merge_cp_p or not a direct match
+-    int found_i = scratch_cp->find_matching_operand(old_bs_i, *merge_cp_p,
+-                                                    _operands_cur_length, THREAD);
+-    if (found_i != -1) {
+-      guarantee(found_i != old_bs_i, "compare_operand_to() and find_matching_operand() disagree");
+-      // found a matching operand somewhere else in *merge_cp_p so just need a mapping
+-      new_bs_i = found_i;
+-      map_operand_index(old_bs_i, found_i);
+-    } else {
+-      // no match found so we have to append this bootstrap specifier to *merge_cp_p
+-      append_operand(scratch_cp, old_bs_i, merge_cp_p, merge_cp_length_p, THREAD);
+-      new_bs_i = _operands_cur_length - 1;
++        unlock_threads();
++        RC_TRACE(0x00000001, ("Found new number of affected classes: %d",
++          new_count));
++      }
+     }
+   }
+-  return new_bs_i;
+-} // end find_or_append_operand()
+ 
++  if (result != JVMTI_ERROR_NONE) {
++    rollback();
++    return result;
++  }
++
++  RC_TIMER_STOP(_timer_prologue);
++  RC_TIMER_START(_timer_class_linking);
++  // Link and verify new classes _after_ all classes have been updated in the system dictionary!
++  for (int i=0; i<all_affected_klasses.length(); i++) {
++    instanceKlassHandle the_class = all_affected_klasses.at(i);
++    instanceKlassHandle new_class(the_class->new_version());
++
++    RC_TRACE(0x00000002, ("Linking class %d/%d %s",
++      i,
++      all_affected_klasses.length(),
++      the_class->name()->as_C_string()));
++    new_class->link_class(THREAD);
+ 
+-void VM_RedefineClasses::finalize_operands_merge(constantPoolHandle merge_cp, TRAPS) {
+-  if (merge_cp->operands() == NULL) {
+-    return;
++    result = check_exception();
++    if (result != JVMTI_ERROR_NONE) break;
+   }
+-  // Shrink the merge_cp operands
+-  merge_cp->shrink_operands(_operands_cur_length, CHECK);
++  RC_TIMER_STOP(_timer_class_linking);
++  RC_TIMER_START(_timer_prologue);
+ 
+-  if (RC_TRACE_ENABLED(0x00040000)) {
+-    // don't want to loop unless we are tracing
+-    int count = 0;
+-    for (int i = 1; i < _operands_index_map_p->length(); i++) {
+-      int value = _operands_index_map_p->at(i);
+-      if (value != -1) {
+-        RC_TRACE_WITH_THREAD(0x00040000, THREAD,
+-          ("operands_index_map[%d]: old=%d new=%d", count, i, value));
+-        count++;
+-      }
++  if (result != JVMTI_ERROR_NONE) {
++    rollback();
++    return result;
++  }
++
++  RC_TRACE(0x00000002, ("All classes loaded!"));
++
++#ifdef ASSERT
++  for (int i=0; i<all_affected_klasses.length(); i++) {
++    instanceKlassHandle the_class = all_affected_klasses.at(i);
++    assert(the_class->new_version() != NULL, "Must have been redefined");
++    instanceKlassHandle new_version = instanceKlassHandle(THREAD, the_class->new_version());
++    assert(new_version->new_version() == NULL, "Must be newest version");
++
++    if (!(new_version->super() == NULL || new_version->super()->klass_part()->new_version() == NULL)) {
++      new_version()->print();
++      new_version->super()->print();
++    }
++    assert(new_version->super() == NULL || new_version->super()->klass_part()->new_version() == NULL, "Super class must be newest version");
++  }
++
++  SystemDictionary::classes_do(check_class, THREAD);
++
++#endif
++
++  RC_TRACE(0x00000001, ("Finished verification!"));
++  return JVMTI_ERROR_NONE;
++}
++
++void VM_RedefineClasses::lock_threads() {
++
++  RC_TIMER_START(_timer_wait_for_locks);
++
++
++  JavaThread *javaThread = Threads::first();
++  while (javaThread != NULL) {
++    if (javaThread->is_Compiler_thread() && javaThread != Thread::current()) {
++      CompilerThread *compilerThread = (CompilerThread *)javaThread;
++      compilerThread->set_should_bailout(true);
++    }
++    javaThread = javaThread->next();
++  }
++
++  int cnt = 0;
++  javaThread = Threads::first();
++  while (javaThread != NULL) {
++    if (javaThread->is_Compiler_thread() && javaThread != Thread::current()) {
++      CompilerThread *compilerThread = (CompilerThread *)javaThread;
++      compilerThread->compilation_mutex()->lock();
++      cnt++;
++    }
++    javaThread = javaThread->next();
++  }
++
++  RC_TRACE(0x00000002, ("Locked %d compiler threads", cnt));
++
++  cnt = 0;
++  javaThread = Threads::first();
++  while (javaThread != NULL) {
++    if (javaThread != Thread::current()) {
++      javaThread->redefine_classes_mutex()->lock();
+     }
++    javaThread = javaThread->next();
+   }
+-  // Clean-up
+-  _operands_index_map_p = NULL;
+-  _operands_cur_length = 0;
+-  _operands_index_map_count = 0;
+-} // end finalize_operands_merge()
+ 
+ 
+-void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class) {
+-  typeArrayOop save;
++  RC_TRACE(0x00000002, ("Locked %d threads", cnt));
++
++  RC_TIMER_STOP(_timer_wait_for_locks);
++}
++
++void VM_RedefineClasses::unlock_threads() {
++
++  int cnt = 0;
++  JavaThread *javaThread = Threads::first();
++  Thread *thread = Thread::current();
++  while (javaThread != NULL) {
++    if (javaThread->is_Compiler_thread() && javaThread != Thread::current()) {
++      CompilerThread *compilerThread = (CompilerThread *)javaThread;
++      if (compilerThread->compilation_mutex()->owned_by_self()) {
++        compilerThread->compilation_mutex()->unlock();
++        cnt++;
++      }
++    }
++    javaThread = javaThread->next();
++  }
+ 
+-  save = scratch_class->get_method_annotations_of(i);
+-  scratch_class->set_method_annotations_of(i, scratch_class->get_method_annotations_of(j));
+-  scratch_class->set_method_annotations_of(j, save);
++  RC_TRACE(0x00000002, ("Unlocked %d compiler threads", cnt));
+ 
+-  save = scratch_class->get_method_parameter_annotations_of(i);
+-  scratch_class->set_method_parameter_annotations_of(i, scratch_class->get_method_parameter_annotations_of(j));
+-  scratch_class->set_method_parameter_annotations_of(j, save);
++  cnt = 0;
++  javaThread = Threads::first();
++  while (javaThread != NULL) {
++    if (javaThread != Thread::current()) {
++      if (javaThread->redefine_classes_mutex()->owned_by_self()) {
++        javaThread->redefine_classes_mutex()->unlock();
++      }
++    }
++    javaThread = javaThread->next();
++  }
+ 
+-  save = scratch_class->get_method_default_annotations_of(i);
+-  scratch_class->set_method_default_annotations_of(i, scratch_class->get_method_default_annotations_of(j));
+-  scratch_class->set_method_default_annotations_of(j, save);
++  RC_TRACE(0x00000002, ("Unlocked %d threads", cnt));
+ }
+ 
++jvmtiError VM_RedefineClasses::check_redefinition_allowed(instanceKlassHandle scratch_class) {
++
++
++  
++  // Compatibility mode => check for unsupported modification
++
++
++  assert(scratch_class->old_version() != NULL, "must have old version");
++  instanceKlassHandle the_class(scratch_class->old_version());
+ 
+-jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+-             instanceKlassHandle the_class,
+-             instanceKlassHandle scratch_class) {
+   int i;
+ 
+   // Check superclasses, or rather their names, since superclasses themselves can be
+   // requested to replace.
+   // Check for NULL superclass first since this might be java.lang.Object
+   if (the_class->super() != scratch_class->super() &&
+-      (the_class->super() == NULL || scratch_class->super() == NULL ||
+-       Klass::cast(the_class->super())->name() !=
+-       Klass::cast(scratch_class->super())->name())) {
+-    return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
++    (the_class->super() == NULL || scratch_class->super() == NULL ||
++    Klass::cast(the_class->super())->name() !=
++    Klass::cast(scratch_class->super())->name())) {
++      return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
+   }
+ 
+   // Check if the number, names and order of directly implemented interfaces are the same.
+@@ -622,8 +678,8 @@ jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+   }
+   for (i = 0; i < n_intfs; i++) {
+     if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() !=
+-        Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) {
+-      return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
++      Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) {
++        return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
+     }
+   }
+ 
+@@ -772,12 +828,8 @@ jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+             idnum_owner->set_method_idnum(new_num);
+           }
+           k_new_method->set_method_idnum(old_num);
+-          swap_all_method_annotations(old_num, new_num, scratch_class);
+         }
+       }
+-      RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
+-                            k_new_method->name_and_sig_as_C_string(), ni,
+-                            k_old_method->name_and_sig_as_C_string(), oi));
+       // advance to next pair of methods
+       ++oi;
+       ++ni;
+@@ -786,11 +838,11 @@ jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+       // method added, see if it is OK
+       new_flags = (jushort) k_new_method->access_flags().get_flags();
+       if ((new_flags & JVM_ACC_PRIVATE) == 0
+-           // hack: private should be treated as final, but alas
+-          || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
+-         ) {
+-        // new methods must be private
+-        return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
++        // hack: private should be treated as final, but alas
++        || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
++        ) {
++          // new methods must be private
++          return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
+       }
+       {
+         u2 num = the_class->next_method_idnum();
+@@ -805,24 +857,19 @@ jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+           idnum_owner->set_method_idnum(new_num);
+         }
+         k_new_method->set_method_idnum(num);
+-        swap_all_method_annotations(new_num, num, scratch_class);
+       }
+-      RC_TRACE(0x00008000, ("Method added: new: %s [%d]",
+-                            k_new_method->name_and_sig_as_C_string(), ni));
+       ++ni; // advance to next new method
+       break;
+     case deleted:
+       // method deleted, see if it is OK
+       old_flags = (jushort) k_old_method->access_flags().get_flags();
+       if ((old_flags & JVM_ACC_PRIVATE) == 0
+-           // hack: private should be treated as final, but alas
+-          || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
+-         ) {
+-        // deleted methods must be private
+-        return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
++        // hack: private should be treated as final, but alas
++        || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
++        ) {
++          // deleted methods must be private
++          return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
+       }
+-      RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]",
+-                            k_old_method->name_and_sig_as_C_string(), oi));
+       ++oi; // advance to next old method
+       break;
+     default:
+@@ -833,2254 +880,1783 @@ jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+   return JVMTI_ERROR_NONE;
+ }
+ 
++int VM_RedefineClasses::calculate_redefinition_flags(instanceKlassHandle new_class) {
+ 
+-// Find new constant pool index value for old constant pool index value
+-// by seaching the index map. Returns zero (0) if there is no mapped
+-// value for the old constant pool index.
+-int VM_RedefineClasses::find_new_index(int old_index) {
+-  if (_index_map_count == 0) {
+-    // map is empty so nothing can be found
+-    return 0;
+-  }
+-
+-  if (old_index < 1 || old_index >= _index_map_p->length()) {
+-    // The old_index is out of range so it is not mapped. This should
+-    // not happen in regular constant pool merging use, but it can
+-    // happen if a corrupt annotation is processed.
+-    return 0;
+-  }
++  int result = Klass::NoRedefinition;
+ 
+-  int value = _index_map_p->at(old_index);
+-  if (value == -1) {
+-    // the old_index is not mapped
+-    return 0;
+-  }
+ 
+-  return value;
+-} // end find_new_index()
+ 
++  RC_TRACE(0x00000002, ("Comparing different class versions of class %s",
++    new_class->name()->as_C_string()));
+ 
+-// Find new bootstrap specifier index value for old bootstrap specifier index
+-// value by seaching the index map. Returns zero (-1) if there is no mapped
+-// value for the old bootstrap specifier index.
+-int VM_RedefineClasses::find_new_operand_index(int old_index) {
+-  if (_operands_index_map_count == 0) {
+-    // map is empty so nothing can be found
+-    return -1;
+-  }
++  assert(new_class->old_version() != NULL, "must have old version");
++  instanceKlassHandle the_class(new_class->old_version());
+ 
+-  if (old_index == -1 || old_index >= _operands_index_map_p->length()) {
+-    // The old_index is out of range so it is not mapped.
+-    // This should not happen in regular constant pool merging use.
+-    return -1;
++  // Check whether class is in the error init state.
++  if (the_class->is_in_error_state()) {
++    // TBD #5057930: special error code is needed in 1.6
++    //result = Klass::union_redefinition_level(result, Klass::Invalid);
+   }
+ 
+-  int value = _operands_index_map_p->at(old_index);
+-
+-  return value;
+-} // end find_new_operand_index()
+-
+-
+-// Returns true if the current mismatch is due to a resolved/unresolved
+-// class pair. Otherwise, returns false.
+-bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1,
+-       int index1, constantPoolHandle cp2, int index2) {
++  int i;
+ 
+-  jbyte t1 = cp1->tag_at(index1).value();
+-  if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) {
+-    return false;  // wrong entry type; not our special case
+-  }
++  //////////////////////////////////////////////////////////////////////////////////////////////////////////
++  // Check superclasses
++  assert(new_class->super() == NULL || new_class->super()->klass_part()->is_newest_version(), "");
++  if (the_class->super() != new_class->super()) {
++    // Super class changed
++
++    klassOop cur_klass = the_class->super();
++    while (cur_klass != NULL) {
++      if (!new_class->is_subclass_of(cur_klass->klass_part()->newest_version())) {
++        RC_TRACE(0x00000002, ("Removed super class %s",
++          cur_klass->klass_part()->name()->as_C_string()));
++        result = result | Klass::RemoveSuperType | Klass::ModifyInstances | Klass::ModifyClass;
++
++        if (!cur_klass->klass_part()->has_subtype_changed()) {
++          RC_TRACE(0x00000002, ("Subtype changed of class %s",
++            cur_klass->klass_part()->name()->as_C_string()));
++          cur_klass->klass_part()->set_subtype_changed(true);
++        }
++      }
+ 
+-  jbyte t2 = cp2->tag_at(index2).value();
+-  if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) {
+-    return false;  // wrong entry type; not our special case
+-  }
++      cur_klass = cur_klass->klass_part()->super();
++    }
+ 
+-  if (t1 == t2) {
+-    return false;  // not a mismatch; not our special case
++    cur_klass = new_class->super();
++    while (cur_klass != NULL) {
++      if (!the_class->is_subclass_of(cur_klass->klass_part()->old_version())) {
++        RC_TRACE(0x00000002, ("Added super class %s",
++          cur_klass->klass_part()->name()->as_C_string()));
++        result = result | Klass::ModifyClass | Klass::ModifyInstances;
++      }
++      cur_klass = cur_klass->klass_part()->super();
++    }
++  }
++
++  //////////////////////////////////////////////////////////////////////////////////////////////////////////
++  // Check interfaces
++
++  // Interfaces removed?
++  objArrayOop old_interfaces = the_class->transitive_interfaces();
++  for (i = 0; i<old_interfaces->length(); i++) {
++    instanceKlassHandle old_interface((klassOop)old_interfaces->obj_at(i));
++    if (!new_class->implements_interface_any_version(old_interface())) {
++      result = result | Klass::RemoveSuperType | Klass::ModifyClass;
++      RC_TRACE(0x00000002, ("Removed interface %s",
++        old_interface->name()->as_C_string()));
++      
++      if (!old_interface->has_subtype_changed()) {
++        RC_TRACE(0x00000002, ("Subtype changed of interface %s",
++          old_interface->name()->as_C_string()));
++        old_interface->set_subtype_changed(true);
++      }
++    }
+   }
+ 
+-  char *s1 = cp1->klass_name_at(index1)->as_C_string();
+-  char *s2 = cp2->klass_name_at(index2)->as_C_string();
+-  if (strcmp(s1, s2) != 0) {
+-    return false;  // strings don't match; not our special case
++  // Interfaces added?
++  objArrayOop new_interfaces = new_class->transitive_interfaces();
++  for (i = 0; i<new_interfaces->length(); i++) {
++    if (!the_class->implements_interface_any_version((klassOop)new_interfaces->obj_at(i))) {
++      result = result | Klass::ModifyClass;
++      RC_TRACE(0x00000002, ("Added interface %s",
++        ((klassOop)new_interfaces->obj_at(i))->klass_part()->name()->as_C_string()));
++    }
+   }
+ 
+-  return true;  // made it through the gauntlet; this is our special case
+-} // end is_unresolved_class_mismatch()
+ 
+-
+-// Returns true if the current mismatch is due to a resolved/unresolved
+-// string pair. Otherwise, returns false.
+-bool VM_RedefineClasses::is_unresolved_string_mismatch(constantPoolHandle cp1,
+-       int index1, constantPoolHandle cp2, int index2) {
+-
+-  jbyte t1 = cp1->tag_at(index1).value();
+-  if (t1 != JVM_CONSTANT_String && t1 != JVM_CONSTANT_UnresolvedString) {
+-    return false;  // wrong entry type; not our special case
+-  }
+-
+-  jbyte t2 = cp2->tag_at(index2).value();
+-  if (t2 != JVM_CONSTANT_String && t2 != JVM_CONSTANT_UnresolvedString) {
+-    return false;  // wrong entry type; not our special case
++  // Check whether class modifiers are the same.
++  jushort old_flags = (jushort) the_class->access_flags().get_flags();
++  jushort new_flags = (jushort) new_class->access_flags().get_flags();
++  if (old_flags != new_flags) {
++    // TODO (tw): Can this have any effects?
+   }
+ 
+-  if (t1 == t2) {
+-    return false;  // not a mismatch; not our special case
+-  }
+-
+-  char *s1 = cp1->string_at_noresolve(index1);
+-  char *s2 = cp2->string_at_noresolve(index2);
+-  if (strcmp(s1, s2) != 0) {
+-    return false;  // strings don't match; not our special case
++  // Check if the number, names, types and order of fields declared in these classes
++  // are the same.
++  JavaFieldStream old_fs(the_class);
++  JavaFieldStream new_fs(new_class);
++  for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) {
++    // access
++    old_flags = old_fs.access_flags().as_short();
++    new_flags = new_fs.access_flags().as_short();
++    if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
++      // (tw) Can this have any effects?
++    }
++    // offset
++    if (old_fs.offset() != new_fs.offset()) {
++        result = result | Klass::ModifyInstances;
++    }
++    // name and signature
++    Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index());
++    Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index());
++    Symbol* name_sym2 = new_class->constants()->symbol_at(new_fs.name_index());
++    Symbol* sig_sym2 = new_class->constants()->symbol_at(new_fs.signature_index());
++    if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
++      result = result | Klass::ModifyInstances;
++    }
+   }
+ 
+-  return true;  // made it through the gauntlet; this is our special case
+-} // end is_unresolved_string_mismatch()
+-
+-
+-jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
+-  // For consistency allocate memory using os::malloc wrapper.
+-  _scratch_classes = (instanceKlassHandle *)
+-    os::malloc(sizeof(instanceKlassHandle) * _class_count, mtInternal);
+-  if (_scratch_classes == NULL) {
+-    return JVMTI_ERROR_OUT_OF_MEMORY;
++  if (!old_fs.done() || !new_fs.done()) {
++    result = result | Klass::ModifyInstances;
+   }
+ 
+-  ResourceMark rm(THREAD);
+-
+-  JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
+-  // state can only be NULL if the current thread is exiting which
+-  // should not happen since we're trying to do a RedefineClasses
+-  guarantee(state != NULL, "exiting thread calling load_new_class_versions");
+-  for (int i = 0; i < _class_count; i++) {
+-    oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
+-    // classes for primitives cannot be redefined
+-    if (!is_modifiable_class(mirror)) {
+-      return JVMTI_ERROR_UNMODIFIABLE_CLASS;
+-    }
+-    klassOop the_class_oop = java_lang_Class::as_klassOop(mirror);
+-    instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
+-    Symbol*  the_class_sym = the_class->name();
+-
+-    // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-    RC_TRACE_WITH_THREAD(0x00000001, THREAD,
+-      ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)",
+-      the_class->external_name(), _class_load_kind,
+-      os::available_memory() >> 10));
+-
+-    ClassFileStream st((u1*) _class_defs[i].class_bytes,
+-      _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
+-
+-    // Parse the stream.
+-    Handle the_class_loader(THREAD, the_class->class_loader());
+-    Handle protection_domain(THREAD, the_class->protection_domain());
+-    // Set redefined class handle in JvmtiThreadState class.
+-    // This redefined class is sent to agent event handler for class file
+-    // load hook event.
+-    state->set_class_being_redefined(&the_class, _class_load_kind);
++  // Do a parallel walk through the old and new methods. Detect
++  // cases where they match (exist in both), have been added in
++  // the new methods, or have been deleted (exist only in the
++  // old methods).  The class file parser places methods in order
++  // by method name, but does not order overloaded methods by
++  // signature.  In order to determine what fate befell the methods,
++  // this code places the overloaded new methods that have matching
++  // old methods in the same order as the old methods and places
++  // new overloaded methods at the end of overloaded methods of
++  // that name. The code for this order normalization is adapted
++  // from the algorithm used in instanceKlass::find_method().
++  // Since we are swapping out of order entries as we find them,
++  // we only have to search forward through the overloaded methods.
++  // Methods which are added and have the same name as an existing
++  // method (but different signature) will be put at the end of
++  // the methods with that name, and the name mismatch code will
++  // handle them.
++  objArrayHandle k_old_methods(the_class->methods());
++  objArrayHandle k_new_methods(new_class->methods());
++  int n_old_methods = k_old_methods->length();
++  int n_new_methods = k_new_methods->length();
+ 
+-    klassOop k = SystemDictionary::parse_stream(the_class_sym,
+-                                                the_class_loader,
+-                                                protection_domain,
+-                                                &st,
+-                                                THREAD);
+-    // Clear class_being_redefined just to be sure.
+-    state->clear_class_being_redefined();
++  int ni = 0;
++  int oi = 0;
++  while (true) {
++    methodOop k_old_method;
++    methodOop k_new_method;
++    enum { matched, added, deleted, undetermined } method_was = undetermined;
+ 
+-    // TODO: if this is retransform, and nothing changed we can skip it
+-
+-    instanceKlassHandle scratch_class (THREAD, k);
+-
+-    if (HAS_PENDING_EXCEPTION) {
+-      Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
+-      // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-      RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'",
+-        ex_name->as_C_string()));
+-      CLEAR_PENDING_EXCEPTION;
+-
+-      if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
+-        return JVMTI_ERROR_UNSUPPORTED_VERSION;
+-      } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
+-        return JVMTI_ERROR_INVALID_CLASS_FORMAT;
+-      } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
+-        return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
+-      } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
+-        // The message will be "XXX (wrong name: YYY)"
+-        return JVMTI_ERROR_NAMES_DONT_MATCH;
+-      } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
+-        return JVMTI_ERROR_OUT_OF_MEMORY;
+-      } else {  // Just in case more exceptions can be thrown..
+-        return JVMTI_ERROR_FAILS_VERIFICATION;
+-      }
+-    }
+-
+-    // Ensure class is linked before redefine
+-    if (!the_class->is_linked()) {
+-      the_class->link_class(THREAD);
+-      if (HAS_PENDING_EXCEPTION) {
+-        Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
+-        // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-        RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'",
+-          ex_name->as_C_string()));
+-        CLEAR_PENDING_EXCEPTION;
+-        if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
+-          return JVMTI_ERROR_OUT_OF_MEMORY;
++    if (oi >= n_old_methods) {
++      if (ni >= n_new_methods) {
++        break; // we've looked at everything, done
++      }
++      // New method at the end
++      k_new_method = (methodOop) k_new_methods->obj_at(ni);
++      method_was = added;
++    } else if (ni >= n_new_methods) {
++      // Old method, at the end, is deleted
++      k_old_method = (methodOop) k_old_methods->obj_at(oi);
++      method_was = deleted;
++    } else {
++      // There are more methods in both the old and new lists
++      k_old_method = (methodOop) k_old_methods->obj_at(oi);
++      k_new_method = (methodOop) k_new_methods->obj_at(ni);
++      if (k_old_method->name() != k_new_method->name()) {
++        // Methods are sorted by method name, so a mismatch means added
++        // or deleted
++        if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) {
++          method_was = added;
+         } else {
+-          return JVMTI_ERROR_INTERNAL;
++          method_was = deleted;
++        }
++      } else if (k_old_method->signature() == k_new_method->signature()) {
++        // Both the name and signature match
++        method_was = matched;
++      } else {
++        // The name matches, but the signature doesn't, which means we have to
++        // search forward through the new overloaded methods.
++        int nj;  // outside the loop for post-loop check
++        for (nj = ni + 1; nj < n_new_methods; nj++) {
++          methodOop m = (methodOop)k_new_methods->obj_at(nj);
++          if (k_old_method->name() != m->name()) {
++            // reached another method name so no more overloaded methods
++            method_was = deleted;
++            break;
++          }
++          if (k_old_method->signature() == m->signature()) {
++            // found a match so swap the methods
++            k_new_methods->obj_at_put(ni, m);
++            k_new_methods->obj_at_put(nj, k_new_method);
++            k_new_method = m;
++            method_was = matched;
++            break;
++          }
++        }
++
++        if (nj >= n_new_methods) {
++          // reached the end without a match; so method was deleted
++          method_was = deleted;
+         }
+       }
+     }
+ 
+-    // Do the validity checks in compare_and_normalize_class_versions()
+-    // before verifying the byte codes. By doing these checks first, we
+-    // limit the number of functions that require redirection from
+-    // the_class to scratch_class. In particular, we don't have to
+-    // modify JNI GetSuperclass() and thus won't change its performance.
+-    jvmtiError res = compare_and_normalize_class_versions(the_class,
+-                       scratch_class);
+-    if (res != JVMTI_ERROR_NONE) {
+-      return res;
++    switch (method_was) {
++  case matched:
++    // methods match, be sure modifiers do too
++    old_flags = (jushort) k_old_method->access_flags().get_flags();
++    new_flags = (jushort) k_new_method->access_flags().get_flags();
++    if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) {
++      // (tw) Can this have any effects? Probably yes on vtables?
++      result = result | Klass::ModifyClass;
+     }
+-
+-    // verify what the caller passed us
+     {
+-      // The bug 6214132 caused the verification to fail.
+-      // Information about the_class and scratch_class is temporarily
+-      // recorded into jvmtiThreadState. This data is used to redirect
+-      // the_class to scratch_class in the JVM_* functions called by the
+-      // verifier. Please, refer to jvmtiThreadState.hpp for the detailed
+-      // description.
+-      RedefineVerifyMark rvm(&the_class, &scratch_class, state);
+-      Verifier::verify(
+-        scratch_class, Verifier::ThrowException, true, THREAD);
+-    }
+-
+-    if (HAS_PENDING_EXCEPTION) {
+-      Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
+-      // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-      RC_TRACE_WITH_THREAD(0x00000002, THREAD,
+-        ("verify_byte_codes exception: '%s'", ex_name->as_C_string()));
+-      CLEAR_PENDING_EXCEPTION;
+-      if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
+-        return JVMTI_ERROR_OUT_OF_MEMORY;
+-      } else {
+-        // tell the caller the bytecodes are bad
+-        return JVMTI_ERROR_FAILS_VERIFICATION;
++      u2 new_num = k_new_method->method_idnum();
++      u2 old_num = k_old_method->method_idnum();
++      if (new_num != old_num) {
++        methodOop idnum_owner = new_class->method_with_idnum(old_num);
++        if (idnum_owner != NULL) {
++          // There is already a method assigned this idnum -- switch them
++          idnum_owner->set_method_idnum(new_num);
++        }
++        k_new_method->set_method_idnum(old_num);
++        RC_TRACE(0x00000002, ("swapping idnum of new and old method %d / %d!",
++          new_num,
++          old_num));
++       // swap_all_method_annotations(old_num, new_num, new_class);
+       }
+     }
+-
+-    res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
+-    if (res != JVMTI_ERROR_NONE) {
+-      return res;
++    RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
++      k_new_method->name_and_sig_as_C_string(), ni,
++      k_old_method->name_and_sig_as_C_string(), oi));
++    // advance to next pair of methods
++    ++oi;
++    ++ni;
++    break;
++  case added:
++    // method added, see if it is OK
++    new_flags = (jushort) k_new_method->access_flags().get_flags();
++    if ((new_flags & JVM_ACC_PRIVATE) == 0
++      // hack: private should be treated as final, but alas
++      || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
++      ) {
++        // new methods must be private
++        result = result | Klass::ModifyClass;
+     }
+-
+-    if (VerifyMergedCPBytecodes) {
+-      // verify what we have done during constant pool merging
+-      {
+-        RedefineVerifyMark rvm(&the_class, &scratch_class, state);
+-        Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD);
++    {
++      u2 num = the_class->next_method_idnum();
++      if (num == constMethodOopDesc::UNSET_IDNUM) {
++        // cannot add any more methods
++        result = result | Klass::ModifyClass;
+       }
+-
+-      if (HAS_PENDING_EXCEPTION) {
+-        Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
+-        // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-        RC_TRACE_WITH_THREAD(0x00000002, THREAD,
+-          ("verify_byte_codes post merge-CP exception: '%s'",
+-          ex_name->as_C_string()));
+-        CLEAR_PENDING_EXCEPTION;
+-        if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
+-          return JVMTI_ERROR_OUT_OF_MEMORY;
+-        } else {
+-          // tell the caller that constant pool merging screwed up
+-          return JVMTI_ERROR_INTERNAL;
+-        }
++      u2 new_num = k_new_method->method_idnum();
++      methodOop idnum_owner = new_class->method_with_idnum(num);
++      if (idnum_owner != NULL) {
++        // There is already a method assigned this idnum -- switch them
++        idnum_owner->set_method_idnum(new_num);
+       }
++      k_new_method->set_method_idnum(num);
++      //swap_all_method_annotations(new_num, num, new_class);
+     }
+-
+-    Rewriter::rewrite(scratch_class, THREAD);
+-    if (!HAS_PENDING_EXCEPTION) {
+-      Rewriter::relocate_and_link(scratch_class, THREAD);
++    RC_TRACE(0x00000001, ("Method added: new: %s [%d]",
++      k_new_method->name_and_sig_as_C_string(), ni));
++    ++ni; // advance to next new method
++    break;
++  case deleted:
++    // method deleted, see if it is OK
++    old_flags = (jushort) k_old_method->access_flags().get_flags();
++    if ((old_flags & JVM_ACC_PRIVATE) == 0
++      // hack: private should be treated as final, but alas
++      || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
++      ) {
++        // deleted methods must be private
++        result = result | Klass::ModifyClass;
+     }
+-    if (HAS_PENDING_EXCEPTION) {
+-      Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
+-      CLEAR_PENDING_EXCEPTION;
+-      if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
+-        return JVMTI_ERROR_OUT_OF_MEMORY;
+-      } else {
+-        return JVMTI_ERROR_INTERNAL;
+-      }
++    RC_TRACE(0x00000001, ("Method deleted: old: %s [%d]",
++      k_old_method->name_and_sig_as_C_string(), oi));
++    ++oi; // advance to next old method
++    break;
++  default:
++    ShouldNotReachHere();
+     }
++  }
++
++  if (new_class()->size() != new_class->old_version()->size()) {
++    result |= Klass::ModifyClassSize;
++  }
+ 
+-    _scratch_classes[i] = scratch_class;
++  if (new_class->size_helper() != ((instanceKlass*)(new_class->old_version()->klass_part()))->size_helper()) {
++    result |= Klass::ModifyInstanceSize;
++  }
+ 
+-    // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
+-    RC_TRACE_WITH_THREAD(0x00000001, THREAD,
+-      ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)",
+-      the_class->external_name(), os::available_memory() >> 10));
++  methodHandle instanceTransformerMethod(new_class->find_method(vmSymbols::transformer_name(), vmSymbols::void_method_signature()));
++  if (!instanceTransformerMethod.is_null() && !instanceTransformerMethod->is_static()) {
++    result |= Klass::HasInstanceTransformer;
+   }
+ 
+-  return JVMTI_ERROR_NONE;
++  // (tw) Check method bodies to be able to return NoChange?
++  return result;
+ }
+ 
++void VM_RedefineClasses::calculate_instance_update_information(klassOop new_version) {
+ 
+-// Map old_index to new_index as needed. scratch_cp is only needed
+-// for RC_TRACE() calls.
+-void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp,
+-       int old_index, int new_index) {
+-  if (find_new_index(old_index) != 0) {
+-    // old_index is already mapped
+-    return;
+-  }
++  class UpdateFieldsEvolutionClosure : public FieldEvolutionClosure {
+ 
+-  if (old_index == new_index) {
+-    // no mapping is needed
+-    return;
+-  }
++  private:
+ 
+-  _index_map_p->at_put(old_index, new_index);
+-  _index_map_count++;
++    GrowableArray<int> info;
++    int curPosition;
++    bool copy_backwards;
+ 
+-  RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d",
+-    scratch_cp->tag_at(old_index).value(), old_index, new_index));
+-} // end map_index()
++  public:
+ 
++    bool does_copy_backwards() {
++      return copy_backwards;
++    }
+ 
+-// Map old_index to new_index as needed.
+-void VM_RedefineClasses::map_operand_index(int old_index, int new_index) {
+-  if (find_new_operand_index(old_index) != -1) {
+-    // old_index is already mapped
+-    return;
+-  }
++    UpdateFieldsEvolutionClosure(klassOop klass) {
+ 
+-  if (old_index == new_index) {
+-    // no mapping is needed
+-    return;
+-  }
++      int base_offset = instanceOopDesc::base_offset_in_bytes();
+ 
+-  _operands_index_map_p->at_put(old_index, new_index);
+-  _operands_index_map_count++;
++      if (klass->klass_part()->newest_version() == SystemDictionary::Reference_klass()->klass_part()->newest_version()) {
++        base_offset += java_lang_ref_Reference::number_of_fake_oop_fields*size_of_type(T_OBJECT);
++      }
+ 
+-  RC_TRACE(0x00040000, ("mapped bootstrap specifier at index %d to %d", old_index, new_index));
+-} // end map_index()
++      info.append(base_offset);
++      info.append(0);
++      curPosition = base_offset;
++      copy_backwards = false;
++    }
+ 
++    GrowableArray<int> &finish() {
++      info.append(0);
++      return info;
++    }
+ 
+-// Merge old_cp and scratch_cp and return the results of the merge via
+-// merge_cp_p. The number of entries in *merge_cp_p is returned via
+-// merge_cp_length_p. The entries in old_cp occupy the same locations
+-// in *merge_cp_p. Also creates a map of indices from entries in
+-// scratch_cp to the corresponding entry in *merge_cp_p. Index map
+-// entries are only created for entries in scratch_cp that occupy a
+-// different location in *merged_cp_p.
+-bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp,
+-       constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
+-       int *merge_cp_length_p, TRAPS) {
++    virtual void do_new_field(fieldDescriptor* fd){
++      int alignment = fd->offset() - curPosition;
++      if (alignment > 0) {
++        // This field was aligned, so we need to make sure that we fill the gap
++        fill(alignment);
++      }
+ 
+-  if (merge_cp_p == NULL) {
+-    assert(false, "caller must provide scatch constantPool");
+-    return false; // robustness
+-  }
+-  if (merge_cp_length_p == NULL) {
+-    assert(false, "caller must provide scatch CP length");
+-    return false; // robustness
+-  }
+-  // Worst case we need old_cp->length() + scratch_cp()->length(),
+-  // but the caller might be smart so make sure we have at least
+-  // the minimum.
+-  if ((*merge_cp_p)->length() < old_cp->length()) {
+-    assert(false, "merge area too small");
+-    return false; // robustness
+-  }
++      int size = size_of_type(fd->field_type());
++      fill(size);
++    }
+ 
+-  RC_TRACE_WITH_THREAD(0x00010000, THREAD,
+-    ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
+-    scratch_cp->length()));
++  private:
+ 
+-  {
+-    // Pass 0:
+-    // The old_cp is copied to *merge_cp_p; this means that any code
+-    // using old_cp does not have to change. This work looks like a
+-    // perfect fit for constantPoolOop::copy_cp_to(), but we need to
+-    // handle one special case:
+-    // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass
+-    // This will make verification happy.
+-
+-    int old_i;  // index into old_cp
+-
+-    // index zero (0) is not used in constantPools
+-    for (old_i = 1; old_i < old_cp->length(); old_i++) {
+-      // leave debugging crumb
+-      jbyte old_tag = old_cp->tag_at(old_i).value();
+-      switch (old_tag) {
+-      case JVM_CONSTANT_Class:
+-      case JVM_CONSTANT_UnresolvedClass:
+-        // revert the copy to JVM_CONSTANT_UnresolvedClass
+-        // May be resolving while calling this so do the same for
+-        // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition)
+-        (*merge_cp_p)->unresolved_klass_at_put(old_i,
+-          old_cp->klass_name_at(old_i));
+-        break;
++    void fill(int size) {
++      if (info.length() > 0 && info.at(info.length() - 1) < 0) {
++        (*info.adr_at(info.length() - 1)) -= size;
++      } else {
++        info.append(-size);
++      }
+ 
+-      case JVM_CONSTANT_Double:
+-      case JVM_CONSTANT_Long:
+-        // just copy the entry to *merge_cp_p, but double and long take
+-        // two constant pool entries
+-        constantPoolOopDesc::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
+-        old_i++;
+-        break;
++      curPosition += size;
++    }
+ 
+-      default:
+-        // just copy the entry to *merge_cp_p
+-        constantPoolOopDesc::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
+-        break;
++    int size_of_type(BasicType type) {
++      int size = 0;
++      switch(type) {
++        case T_BOOLEAN:
++          size = sizeof(jboolean);
++          break;
++
++        case T_CHAR:
++          size = (sizeof(jchar));
++          break;
++
++        case T_FLOAT:
++          size = (sizeof(jfloat));
++          break;
++
++        case T_DOUBLE:
++          size = (sizeof(jdouble));
++          break;
++
++        case T_BYTE:
++          size = (sizeof(jbyte));
++          break;
++
++        case T_SHORT:
++          size = (sizeof(jshort));
++          break;
++
++        case T_INT:
++          size = (sizeof(jint));
++          break;
++
++        case T_LONG:
++          size = (sizeof(jlong));
++          break;
++
++        case T_OBJECT:
++        case T_ARRAY:
++          if (UseCompressedOops) {
++            size = sizeof(narrowOop);
++          } else {
++            size = (sizeof(oop));
++          }
++          break;
++
++        default:
++          ShouldNotReachHere();
+       }
+-    } // end for each old_cp entry
+ 
+-    constantPoolOopDesc::copy_operands(old_cp, *merge_cp_p, CHECK_0);
+-    (*merge_cp_p)->extend_operands(scratch_cp, CHECK_0);
++      assert(size > 0, "");
++      return size;
+ 
+-    // We don't need to sanity check that *merge_cp_length_p is within
+-    // *merge_cp_p bounds since we have the minimum on-entry check above.
+-    (*merge_cp_length_p) = old_i;
+-  }
++    }
++    
++  public:
+ 
+-  // merge_cp_len should be the same as old_cp->length() at this point
+-  // so this trace message is really a "warm-and-breathing" message.
+-  RC_TRACE_WITH_THREAD(0x00020000, THREAD,
+-    ("after pass 0: merge_cp_len=%d", *merge_cp_length_p));
++    virtual void do_old_field(fieldDescriptor* fd){}
+ 
+-  int scratch_i;  // index into scratch_cp
+-  {
+-    // Pass 1a:
+-    // Compare scratch_cp entries to the old_cp entries that we have
+-    // already copied to *merge_cp_p. In this pass, we are eliminating
+-    // exact duplicates (matching entry at same index) so we only
+-    // compare entries in the common indice range.
+-    int increment = 1;
+-    int pass1a_length = MIN2(old_cp->length(), scratch_cp->length());
+-    for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) {
+-      switch (scratch_cp->tag_at(scratch_i).value()) {
+-      case JVM_CONSTANT_Double:
+-      case JVM_CONSTANT_Long:
+-        // double and long take two constant pool entries
+-        increment = 2;
+-        break;
++    virtual void do_changed_field(fieldDescriptor* old_fd, fieldDescriptor *new_fd){
+ 
+-      default:
+-        increment = 1;
+-        break;
++      int alignment = new_fd->offset() - curPosition;
++      if (alignment > 0) {
++        // This field was aligned, so we need to make sure that we fill the gap
++        fill(alignment);
+       }
+ 
+-      bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p,
+-        scratch_i, CHECK_0);
+-      if (match) {
+-        // found a match at the same index so nothing more to do
+-        continue;
+-      } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i,
+-                                              *merge_cp_p, scratch_i)) {
+-        // The mismatch in compare_entry_to() above is because of a
+-        // resolved versus unresolved class entry at the same index
+-        // with the same string value. Since Pass 0 reverted any
+-        // class entries to unresolved class entries in *merge_cp_p,
+-        // we go with the unresolved class entry.
+-        continue;
+-      } else if (is_unresolved_string_mismatch(scratch_cp, scratch_i,
+-                                               *merge_cp_p, scratch_i)) {
+-        // The mismatch in compare_entry_to() above is because of a
+-        // resolved versus unresolved string entry at the same index
+-        // with the same string value. We can live with whichever
+-        // happens to be at scratch_i in *merge_cp_p.
+-        continue;
+-      }
+-
+-      int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p,
+-        CHECK_0);
+-      if (found_i != 0) {
+-        guarantee(found_i != scratch_i,
+-          "compare_entry_to() and find_matching_entry() do not agree");
+-
+-        // Found a matching entry somewhere else in *merge_cp_p so
+-        // just need a mapping entry.
+-        map_index(scratch_cp, scratch_i, found_i);
+-        continue;
+-      }
+-
+-      // The find_matching_entry() call above could fail to find a match
+-      // due to a resolved versus unresolved class or string entry situation
+-      // like we solved above with the is_unresolved_*_mismatch() calls.
+-      // However, we would have to call is_unresolved_*_mismatch() over
+-      // all of *merge_cp_p (potentially) and that doesn't seem to be
+-      // worth the time.
+-
+-      // No match found so we have to append this entry and any unique
+-      // referenced entries to *merge_cp_p.
+-      append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
+-        CHECK_0);
+-    }
+-  }
+-
+-  RC_TRACE_WITH_THREAD(0x00020000, THREAD,
+-    ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
+-    *merge_cp_length_p, scratch_i, _index_map_count));
+-
+-  if (scratch_i < scratch_cp->length()) {
+-    // Pass 1b:
+-    // old_cp is smaller than scratch_cp so there are entries in
+-    // scratch_cp that we have not yet processed. We take care of
+-    // those now.
+-    int increment = 1;
+-    for (; scratch_i < scratch_cp->length(); scratch_i += increment) {
+-      switch (scratch_cp->tag_at(scratch_i).value()) {
+-      case JVM_CONSTANT_Double:
+-      case JVM_CONSTANT_Long:
+-        // double and long take two constant pool entries
+-        increment = 2;
+-        break;
++      assert(old_fd->field_type() == new_fd->field_type(), "");
++      assert(curPosition == new_fd->offset(), "must be correct offset!");
+ 
+-      default:
+-        increment = 1;
+-        break;
++      int offset = old_fd->offset();
++      int size = size_of_type(old_fd->field_type());
++
++      int prevEnd = -1;
++      if (info.length() > 0 && info.at(info.length() - 1) > 0) {
++        prevEnd = info.at(info.length() - 2) + info.at(info.length() - 1);
++      }
++
++      if (prevEnd == offset) {
++        info.at_put(info.length() - 2, info.at(info.length() - 2) + size);
++      } else {
++        info.append(size);
++        info.append(offset);
+       }
+ 
+-      int found_i =
+-        scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0);
+-      if (found_i != 0) {
+-        // Found a matching entry somewhere else in *merge_cp_p so
+-        // just need a mapping entry.
+-        map_index(scratch_cp, scratch_i, found_i);
+-        continue;
++      if (old_fd->offset() < new_fd->offset()) {
++        copy_backwards = true;
+       }
+ 
+-      // No match found so we have to append this entry and any unique
+-      // referenced entries to *merge_cp_p.
+-      append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
+-        CHECK_0);
++      transfer_special_access_flags(old_fd, new_fd);
++
++      curPosition += size;
+     }
++  };
+ 
+-    RC_TRACE_WITH_THREAD(0x00020000, THREAD,
+-      ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
+-      *merge_cp_length_p, scratch_i, _index_map_count));
++  UpdateFieldsEvolutionClosure cl(new_version);
++  ((instanceKlass*)new_version->klass_part())->do_fields_evolution(&cl);
++
++  GrowableArray<int> result = cl.finish();
++  ((instanceKlass*)new_version->klass_part())->store_update_information(result);
++  ((instanceKlass*)new_version->klass_part())->set_copying_backwards(cl.does_copy_backwards());
++
++  if (RC_TRACE_ENABLED(0x00000002))  {
++    RC_TRACE(0x00000002, ("Instance update information for %s:",
++      new_version->klass_part()->name()->as_C_string()));
++    if (cl.does_copy_backwards()) {
++      RC_TRACE(0x00000002, ("\tDoes copy backwards!"));
++    }
++    for (int i=0; i<result.length(); i++) {
++      int curNum = result.at(i);
++      if (curNum < 0) {
++        RC_TRACE(0x00000002, ("\t%d CLEAN", curNum));
++      } else if (curNum > 0) {
++        RC_TRACE(0x00000002, ("\t%d COPY from %d", curNum, result.at(i + 1)));
++        i++;
++      } else {
++        RC_TRACE(0x00000002, ("\tEND"));
++      }
++    }
+   }
+-  finalize_operands_merge(*merge_cp_p, THREAD);
++}
+ 
+-  return true;
+-} // end merge_constant_pools()
+-
+-
+-// Merge constant pools between the_class and scratch_class and
+-// potentially rewrite bytecodes in scratch_class to use the merged
+-// constant pool.
+-jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
+-             instanceKlassHandle the_class, instanceKlassHandle scratch_class,
+-             TRAPS) {
+-  // worst case merged constant pool length is old and new combined
+-  int merge_cp_length = the_class->constants()->length()
+-        + scratch_class->constants()->length();
+-
+-  constantPoolHandle old_cp(THREAD, the_class->constants());
+-  constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
+-
+-  // Constant pools are not easily reused so we allocate a new one
+-  // each time.
+-  // merge_cp is created unsafe for concurrent GC processing.  It
+-  // should be marked safe before discarding it. Even though
+-  // garbage,  if it crosses a card boundary, it may be scanned
+-  // in order to find the start of the first complete object on the card.
+-  constantPoolHandle merge_cp(THREAD,
+-    oopFactory::new_constantPool(merge_cp_length,
+-                                 oopDesc::IsUnsafeConc,
+-                                 THREAD));
+-  int orig_length = old_cp->orig_length();
+-  if (orig_length == 0) {
+-    // This old_cp is an actual original constant pool. We save
+-    // the original length in the merged constant pool so that
+-    // merge_constant_pools() can be more efficient. If a constant
+-    // pool has a non-zero orig_length() value, then that constant
+-    // pool was created by a merge operation in RedefineClasses.
+-    merge_cp->set_orig_length(old_cp->length());
+-  } else {
+-    // This old_cp is a merged constant pool from a previous
+-    // RedefineClasses() calls so just copy the orig_length()
+-    // value.
+-    merge_cp->set_orig_length(old_cp->orig_length());
++Symbol* VM_RedefineClasses::signature_to_class_name(Symbol* signature) {
++  assert(FieldType::is_obj(signature), "");
++  return SymbolTable::new_symbol(signature->as_C_string() + 1, signature->utf8_length() - 2, Thread::current());
++}
++
++void VM_RedefineClasses::calculate_type_check_information(klassOop klass) {
++  if (klass->klass_part()->is_redefining()) {
++    klass = klass->klass_part()->old_version();
+   }
+ 
+-  ResourceMark rm(THREAD);
+-  _index_map_count = 0;
+-  _index_map_p = new intArray(scratch_cp->length(), -1);
++  // We found an instance klass!
++  instanceKlass *cur_instance_klass = instanceKlass::cast(klass);
++  GrowableArray< Pair<int, klassOop> > type_check_information;
+ 
+-  _operands_cur_length = constantPoolOopDesc::operand_array_length(old_cp->operands());
+-  _operands_index_map_count = 0;
+-  _operands_index_map_p = new intArray(
+-    constantPoolOopDesc::operand_array_length(scratch_cp->operands()), -1);
++  class MyFieldClosure : public FieldClosure {
+ 
+-  // reference to the cp holder is needed for copy_operands()
+-  merge_cp->set_pool_holder(scratch_class());
+-  bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp,
+-                  &merge_cp_length, THREAD);
+-  merge_cp->set_pool_holder(NULL);
++  public:
+ 
+-  if (!result) {
+-    // The merge can fail due to memory allocation failure or due
+-    // to robustness checks.
+-    return JVMTI_ERROR_INTERNAL;
+-  }
+-
+-  RC_TRACE_WITH_THREAD(0x00010000, THREAD,
+-    ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count));
+-
+-  if (_index_map_count == 0) {
+-    // there is nothing to map between the new and merged constant pools
+-
+-    if (old_cp->length() == scratch_cp->length()) {
+-      // The old and new constant pools are the same length and the
+-      // index map is empty. This means that the three constant pools
+-      // are equivalent (but not the same). Unfortunately, the new
+-      // constant pool has not gone through link resolution nor have
+-      // the new class bytecodes gone through constant pool cache
+-      // rewriting so we can't use the old constant pool with the new
+-      // class.
+-
+-      merge_cp()->set_is_conc_safe(true);
+-      merge_cp = constantPoolHandle();  // toss the merged constant pool
+-    } else if (old_cp->length() < scratch_cp->length()) {
+-      // The old constant pool has fewer entries than the new constant
+-      // pool and the index map is empty. This means the new constant
+-      // pool is a superset of the old constant pool. However, the old
+-      // class bytecodes have already gone through constant pool cache
+-      // rewriting so we can't use the new constant pool with the old
+-      // class.
+-
+-      merge_cp()->set_is_conc_safe(true);
+-      merge_cp = constantPoolHandle();  // toss the merged constant pool
+-    } else {
+-      // The old constant pool has more entries than the new constant
+-      // pool and the index map is empty. This means that both the old
+-      // and merged constant pools are supersets of the new constant
+-      // pool.
+-
+-      // Replace the new constant pool with a shrunken copy of the
+-      // merged constant pool; the previous new constant pool will
+-      // get GCed.
+-      set_new_constant_pool(scratch_class, merge_cp, merge_cp_length,
+-        THREAD);
+-      // drop local ref to the merged constant pool
+-      merge_cp()->set_is_conc_safe(true);
+-      merge_cp = constantPoolHandle();
++    GrowableArray< Pair<int, klassOop> > *_arr;
++
++    MyFieldClosure(GrowableArray< Pair<int, klassOop> > *arr) {
++      _arr = arr;
+     }
+-  } else {
+-    if (RC_TRACE_ENABLED(0x00040000)) {
+-      // don't want to loop unless we are tracing
+-      int count = 0;
+-      for (int i = 1; i < _index_map_p->length(); i++) {
+-        int value = _index_map_p->at(i);
+-
+-        if (value != -1) {
+-          RC_TRACE_WITH_THREAD(0x00040000, THREAD,
+-            ("index_map[%d]: old=%d new=%d", count, i, value));
+-          count++;
++
++    virtual void do_field(fieldDescriptor* fd) {
++      if (fd->field_type() == T_OBJECT) {
++        Symbol* signature = fd->signature();
++        if (FieldType::is_obj(signature)) {
++          Symbol* name = signature_to_class_name(signature);
++          klassOop field_klass;
++          if (is_field_dangerous(name, fd, field_klass)) {
++            RC_TRACE(0x00000002, ("Found dangerous field %s in klass %s of type %s",
++              fd->name()->as_C_string(),
++              fd->field_holder()->klass_part()->name()->as_C_string(),
++              name->as_C_string()));
++            _arr->append(Pair<int, klassOop>(fd->offset(), field_klass->klass_part()->newest_version()));
++          }
+         }
++
++        // Array fields can never be a problem!
+       }
+     }
+ 
+-    // We have entries mapped between the new and merged constant pools
+-    // so we have to rewrite some constant pool references.
+-    if (!rewrite_cp_refs(scratch_class, THREAD)) {
+-      return JVMTI_ERROR_INTERNAL;
++    bool is_field_dangerous(Symbol* klass_name, fieldDescriptor *fd, klassOop &field_klass) {
++      field_klass = SystemDictionary::find(klass_name, fd->field_holder()->klass_part()->class_loader(),
++              fd->field_holder()->klass_part()->protection_domain(), Thread::current());
++      if(field_klass != NULL) {
++        if (field_klass->klass_part()->is_redefining()) {
++          field_klass = field_klass->klass_part()->old_version();
++        }
++        if (field_klass->klass_part()->has_subtype_changed()) {
++          return true;
++        }
++      }
++      return false;
+     }
++  };
++
++  MyFieldClosure fieldClosure(&type_check_information);
++  cur_instance_klass->do_nonstatic_fields(&fieldClosure);
+ 
+-    // Replace the new constant pool with a shrunken copy of the
+-    // merged constant pool so now the rewritten bytecodes have
+-    // valid references; the previous new constant pool will get
+-    // GCed.
+-    set_new_constant_pool(scratch_class, merge_cp, merge_cp_length,
+-      THREAD);
+-    merge_cp()->set_is_conc_safe(true);
++  if (type_check_information.length() > 0) {
++    type_check_information.append(Pair<int, klassOop>(-1, NULL));
++    cur_instance_klass->store_type_check_information(type_check_information);
+   }
+-  assert(old_cp()->is_conc_safe(), "Just checking");
+-  assert(scratch_cp()->is_conc_safe(), "Just checking");
++}
+ 
+-  return JVMTI_ERROR_NONE;
+-} // end merge_cp_and_rewrite()
++bool VM_RedefineClasses::check_field_value_types() {
+ 
++  Thread *THREAD = Thread::current();
++  class CheckFieldTypesClosure : public ObjectClosure {
+ 
+-// Rewrite constant pool references in klass scratch_class.
+-bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
+-       TRAPS) {
++  private:
+ 
+-  // rewrite constant pool references in the methods:
+-  if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
+-    // propagate failure back to caller
+-    return false;
+-  }
++    bool _result;
+ 
+-  // rewrite constant pool references in the class_annotations:
+-  if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) {
+-    // propagate failure back to caller
+-    return false;
+-  }
++  public:
+ 
+-  // rewrite constant pool references in the fields_annotations:
+-  if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) {
+-    // propagate failure back to caller
+-    return false;
+-  }
++    CheckFieldTypesClosure() {
++      _result = true;
++    }
+ 
+-  // rewrite constant pool references in the methods_annotations:
+-  if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) {
+-    // propagate failure back to caller
+-    return false;
+-  }
++    bool result() { return _result; }
+ 
+-  // rewrite constant pool references in the methods_parameter_annotations:
+-  if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class,
+-         THREAD)) {
+-    // propagate failure back to caller
+-    return false;
++    virtual void do_object(oop obj) {
++
++      if (!_result) {
++        return;
++      }
++
++      if (obj->is_objArray()) {
++
++        objArrayOop array = objArrayOop(obj);
++
++        klassOop element_klass = objArrayKlass::cast(array->klass())->element_klass();
++
++        if (element_klass->klass_part()->has_subtype_changed()) {
++          int length = array->length();
++          for (int i=0; i<length; i++) {
++            oop element = array->obj_at(i);
++            if (element != NULL && element->blueprint()->newest_version()->klass_part()->is_redefining()) {
++              // Check subtype relationship to static type of array
++              if (!element->blueprint()->newest_version()->klass_part()->is_subtype_of(element_klass->klass_part()->newest_version())) {
++                RC_TRACE(0x00000001, ("Array value is INVALID - abort redefinition (static_type=%s, index=%d, dynamic_type=%s)",
++                  element_klass->klass_part()->name()->as_C_string(),
++                  i,
++                  element->blueprint()->name()->as_C_string()));
++                _result = false;
++                break;
++              }
++            }
++          }
++        }
++
++      } else {
++        Pair<int, klassOop> *cur = obj->klass()->klass_part()->type_check_information();
++        if (cur != NULL) {
++          // Type check information exists for this oop
++          while ((*cur).left() != -1) {
++            check_field(obj, (*cur).left(), (*cur).right());
++            cur++;
++          }
++        }
++      }
++    }
++
++    void check_field(oop obj, int offset, klassOop static_type) {
++      oop field_value = obj->obj_field(offset);
++      if (field_value != NULL) {
++        // Field is not null
++        if (field_value->klass()->klass_part()->newest_version()->klass_part()->is_subtype_of(static_type)) {
++          // We are OK
++          RC_TRACE(0x00008000, ("Field value is OK (klass=%s, static_type=%s, offset=%d, dynamic_type=%s)",
++            obj->klass()->klass_part()->name()->as_C_string(),
++            static_type->klass_part()->name()->as_C_string(),
++            offset,
++            field_value->klass()->klass_part()->name()->as_C_string()));
++        } else {
++          // Failure!
++          RC_TRACE(0x00000001, ("Field value is INVALID - abort redefinition (klass=%s, static_type=%s, offset=%d, dynamic_type=%s)",
++            obj->klass()->klass_part()->name()->as_C_string(),
++            static_type->klass_part()->name()->as_C_string(),
++            offset,
++            field_value->klass()->klass_part()->name()->as_C_string()));
++          _result = false;
++        }
++      }
++    }
++  };
++
++  CheckFieldTypesClosure myObjectClosure;
++
++  // make sure that heap is parsable (fills TLABs with filler objects)
++  Universe::heap()->ensure_parsability(false);  // no need to retire TLABs
++
++  // do the iteration
++  // If this operation encounters a bad object when using CMS,
++  // consider using safe_object_iterate() which avoids perm gen
++  // objects that may contain bad references.
++  Universe::heap()->object_iterate(&myObjectClosure);
++
++  // when sharing is enabled we must iterate over the shared spaces
++  if (UseSharedSpaces) {
++    GenCollectedHeap* gch = GenCollectedHeap::heap();
++    CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
++    gen->ro_space()->object_iterate(&myObjectClosure);
++    gen->rw_space()->object_iterate(&myObjectClosure);
+   }
+ 
+-  // rewrite constant pool references in the methods_default_annotations:
+-  if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class,
+-         THREAD)) {
+-    // propagate failure back to caller
+-    return false;
++  return myObjectClosure.result();
++}
++
++void VM_RedefineClasses::clear_type_check_information(klassOop k) {
++  if (k->klass_part()->is_redefining()) {
++    k = k->klass_part()->old_version();
+   }
+ 
+-  return true;
+-} // end rewrite_cp_refs()
++  // We found an instance klass!
++  instanceKlass *cur_instance_klass = instanceKlass::cast(k);
++  cur_instance_klass->clear_type_check_information();
++}
+ 
++void VM_RedefineClasses::update_active_methods() {
++
++  RC_TRACE(0x00000002, ("Updating active methods"));
++  JavaThread *java_thread = Threads::first();
++  while (java_thread != NULL) {
++
++    int stack_depth = 0;
++    if (java_thread->has_last_Java_frame()) {
++
++      RC_TRACE(0x0000000400, ("checking stack of Java thread %s", java_thread->name()));
++
++      // vframes are resource allocated
++      Thread* current_thread = Thread::current();
++      ResourceMark rm(current_thread);
++      HandleMark hm(current_thread);
++
++      RegisterMap reg_map(java_thread);
++      frame f = java_thread->last_frame();
++      vframe* vf = vframe::new_vframe(&f, &reg_map, java_thread);
++      frame* last_entry_frame = NULL;
++
++      while (vf != NULL) {
++        if (vf->is_java_frame()) {
++          // java frame (interpreted, compiled, ...)
++          javaVFrame *jvf = javaVFrame::cast(vf);
++
++          if (!(jvf->method()->is_native())) {
++            int bci = jvf->bci();
++            RC_TRACE(0x00000400, ("found method: %s / bci=%d", jvf->method()->name()->as_C_string(), bci));
++            ResourceMark rm(Thread::current());
++            HandleMark hm;
++            instanceKlassHandle klass(jvf->method()->method_holder());
++
++            if (jvf->method()->new_version() != NULL && jvf->is_interpreted_frame()) {
++
++              
++              RC_TRACE(0x00000002, ("Found method that should just be updated to the newest version %s",
++                jvf->method()->name_and_sig_as_C_string()));
++
++              if (RC_TRACE_ENABLED(0x01000000)) {
++                int code_size = jvf->method()->code_size();
++                char *code_base_old = (char*)jvf->method()->code_base();
++                char *code_base_new = (char*)jvf->method()->new_version()->code_base();
++                for (int i=0; i<code_size; i++) {
++                  tty->print_cr("old=%d new=%d", *code_base_old++, *code_base_new++);
++                }
++                jvf->method()->print_codes_on(tty);
++                jvf->method()->new_version()->print_codes_on(tty);
++              }
++              
++              assert(jvf->is_interpreted_frame(), "Every frame must be interpreted!");              
++              interpretedVFrame *iframe = (interpretedVFrame *)jvf;
++
++
++              if (RC_TRACE_ENABLED(0x01000000)) {
++                constantPoolCacheOop cp_old = jvf->method()->constants()->cache();
++                tty->print_cr("old cp");
++                for (int i=0; i<cp_old->length(); i++) {
++                  cp_old->entry_at(i)->print(tty, i);
++                }
++                constantPoolCacheOop cp_new = jvf->method()->new_version()->constants()->cache();
++                tty->print_cr("new cp");
++                for (int i=0; i<cp_new->length(); i++) {
++                  cp_new->entry_at(i)->print(tty, i);
++                }
++              }
++
++              iframe->set_method(jvf->method()->new_version(), bci);
++              RC_TRACE(0x00000002, ("Updated method to newer version"));
++              assert(jvf->method()->new_version() == NULL, "must be latest version");
++
++            }
++          } 
++        }
++        vf = vf->sender();
++      }
++    }
+ 
+-// Rewrite constant pool references in the methods.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
+-       instanceKlassHandle scratch_class, TRAPS) {
++    // Advance to next thread
++    java_thread = java_thread->next();
++  }
++}
+ 
+-  objArrayHandle methods(THREAD, scratch_class->methods());
++void VM_RedefineClasses::method_forwarding() {
++
++  int forwarding_count = 0;
++  JavaThread *java_thread = Threads::first();
++  while (java_thread != NULL) {
++
++    int stack_depth = 0;
++    if (java_thread->has_last_Java_frame()) {
++
++      RC_TRACE(0x00000400, ("checking stack of Java thread %s", java_thread->name()));
++
++      // vframes are resource allocated
++      Thread* current_thread = Thread::current();
++      ResourceMark rm(current_thread);
++      HandleMark hm(current_thread);
++
++      RegisterMap reg_map(java_thread);
++      frame f = java_thread->last_frame();
++      vframe* vf = vframe::new_vframe(&f, &reg_map, java_thread);
++      frame* last_entry_frame = NULL;
++
++      while (vf != NULL) {
++        if (vf->is_java_frame()) {
++          // java frame (interpreted, compiled, ...)
++          javaVFrame *jvf = javaVFrame::cast(vf);
++
++          if (!(jvf->method()->is_native())) {
++            RC_TRACE(0x00008000, ("found method: %s",
++              jvf->method()->name()->as_C_string()));
++            ResourceMark rm(Thread::current());
++            HandleMark hm;
++            instanceKlassHandle klass(jvf->method()->method_holder());
++            methodOop m = jvf->method();
++            int bci = jvf->bci();
++            RC_TRACE(0x00008000, ("klass redef %d",
++              klass->is_redefining()));
++
++            if (klass->new_version() != NULL && m->new_version() == NULL) {
++              RC_TRACE(0x00008000, ("found potential forwarding method: %s",
++                m->name()->as_C_string()));
++              
++              klassOop new_klass = klass->newest_version();
++              methodOop new_method = new_klass->klass_part()->lookup_method(m->name(), m->signature());
++              RC_TRACE(0x00000002, ("%d %d",
++                new_method,
++                new_method->constMethod()->has_code_section_table()));
++
++              if (new_method != NULL && new_method->constMethod()->has_code_section_table()) {
++                RC_TRACE(0x00008000, ("found code section table for method: %s",
++                  new_method->name()->as_C_string()));
++                m->set_forward_method(new_method);
++                if (new_method->max_locals() != m->max_locals()) {
++                  tty->print_cr("new_m max locals: %d old_m max locals: %d", new_method->max_locals(), m->max_locals());
++                }
++                assert(new_method->max_locals() == m->max_locals(), "number of locals must match");
++                assert(new_method->max_stack() == m->max_stack(), "number of stack values must match");
++                if (jvf->is_interpreted_frame()) {
++                  if (m->is_in_code_section(bci)) {
++                    // We must transfer now and cannot delay until next NOP.
++                    int new_bci = m->calculate_forward_bci(bci, new_method);
++                    interpretedVFrame* iframe = interpretedVFrame::cast(jvf);
++                    RC_TRACE(0x00000002, ("Transferring execution of %s to new method old_bci=%d new_bci=%d",
++                      new_method->name()->as_C_string(),
++                      bci,
++                      new_bci));
++                    iframe->set_method(new_method, new_bci);
++                  } else {
++                    RC_TRACE(0x00000002, ("Delaying method forwarding of %s because %d is not in a code section",
++                      new_method->name()->as_C_string(),
++                      bci));
++                  }
++                } else {
++                  RC_TRACE(0x00000002, ("Delaying method forwarding of %s because method is compiled",
++                    new_method->name()->as_C_string()));
++                }
++              }
++            }
++          } 
++        }
++        vf = vf->sender();
++      }
++    }
+ 
+-  if (methods.is_null() || methods->length() == 0) {
+-    // no methods so nothing to do
+-    return true;
++    // Advance to next thread
++    java_thread = java_thread->next();
+   }
+ 
+-  // rewrite constant pool references in the methods:
+-  for (int i = methods->length() - 1; i >= 0; i--) {
+-    methodHandle method(THREAD, (methodOop)methods->obj_at(i));
+-    methodHandle new_method;
+-    rewrite_cp_refs_in_method(method, &new_method, CHECK_false);
+-    if (!new_method.is_null()) {
+-      // the method has been replaced so save the new method version
+-      methods->obj_at_put(i, new_method());
++  RC_TRACE(0x00000001, ("Method forwarding applied to %d methods",
++    forwarding_count));
++}
++
++bool VM_RedefineClasses::check_method_stacks() {
++
++  JavaThread *java_thread = Threads::first();
++  while (java_thread != NULL) {
++
++    int stack_depth = 0;
++    if (java_thread->has_last_Java_frame()) {
++
++      RC_TRACE(0x00000400, ("checking stack of Java thread %s", java_thread->name()));
++
++      // vframes are resource allocated
++      Thread* current_thread = Thread::current();
++      ResourceMark rm(current_thread);
++      HandleMark hm(current_thread);
++
++      RegisterMap reg_map(java_thread);
++      frame f = java_thread->last_frame();
++      vframe* vf = vframe::new_vframe(&f, &reg_map, java_thread);
++      frame* last_entry_frame = NULL;
++
++      while (vf != NULL) {
++        if (vf->is_java_frame()) {
++          // java frame (interpreted, compiled, ...)
++          javaVFrame *jvf = javaVFrame::cast(vf);
++
++          if (!(jvf->method()->is_native())) {
++            RC_TRACE(0x00000400, ("found method: %s", jvf->method()->name()->as_C_string()));
++            ResourceMark rm(Thread::current());
++            HandleMark hm;
++            instanceKlassHandle klass(jvf->method()->method_holder());
++
++            StackValueCollection *locals = jvf->locals();
++            const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
++            char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
++
++            for (int i=0; i<locals->size(); i++) {
++              StackValue *stack_value = locals->at(i);
++              if (stack_value->type() == T_OBJECT) {
++                Handle obj = stack_value->get_obj();
++                if (!obj.is_null() && obj->klass()->klass_part()->newest_version()->klass_part()->check_redefinition_flag(Klass::RemoveSuperType)) {
++                  
++                  // OK, so this is a possible failure => check local variable table, if it could be OK.
++                  bool result = false;
++                  methodOop method = jvf->method();
++                  if (method->has_localvariable_table()) {
++                    LocalVariableTableElement *elem = jvf->method()->localvariable_table_start();
++                    for (int j=0; j<method->localvariable_table_length(); j++) {
++
++                      if (elem->slot == i) {
++
++                        // Matching index found
++
++                        if (elem->start_bci <= jvf->bci() && elem->start_bci + elem->length > jvf->bci()) {
++
++                          // Also in range!!
++                          Symbol* signature = jvf->method()->constants()->symbol_at(elem->descriptor_cp_index);
++                          Symbol* klass_name = signature_to_class_name(signature);
++
++                          klassOop local_klass = SystemDictionary::find(klass_name, jvf->method()->method_holder()->klass_part()->class_loader(), jvf->method()->method_holder()->klass_part()->protection_domain(), Thread::current())->klass_part()->newest_version();
++                          klassOop cur = obj->klass()->klass_part()->newest_version();
++
++                          // Field is not null
++                          if (cur->klass_part()->newest_version()->klass_part()->is_subtype_of(local_klass)) {
++                            // We are OK
++                            RC_TRACE(0x00008000, ("Local variable value is OK (local_klass=%s, cur_klass=%s)",
++                              local_klass->klass_part()->name()->as_C_string(), cur->klass_part()->name()->as_C_string()));
++                            result = true;
++                          } else {
++                            // Failure!
++                            RC_TRACE(0x00000001, ("Local variable value is INVALID - abort redefinition (local_klass=%s, cur_klass=%s)",
++                              local_klass->klass_part()->name()->as_C_string(),
++                              cur->klass_part()->name()->as_C_string()));
++                            return false;
++                          }
++                        }
++                      }
++
++                      elem++;
++                    }
++                  } else {
++                    RC_TRACE(0x00000002, ("Method %s does not have a local variable table => abort",
++                      method->name_and_sig_as_C_string()));
++                  }
++                  
++                  if (!result) {
++                    return false;
++                  }
++
++                  RC_TRACE(0x00008000, ("Verifying class %s",
++                    jvf->method()->method_holder()->klass_part()->name()->as_C_string()));
++
++                  Symbol* exception_name;
++                  const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
++                  char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
++
++                  Thread::current()->set_pretend_new_universe(true);
++                  ClassVerifier split_verifier(klass, Thread::current());
++                  split_verifier.verify_method(jvf->method(), Thread::current());
++                  exception_name = split_verifier.result();
++                  Thread::current()->set_pretend_new_universe(false);
++
++                  if (exception_name != NULL) {
++                 
++                    RC_TRACE(0x00000001, ("Verification of class %s failed",
++                      jvf->method()->method_holder()->klass_part()->name()->as_C_string()));
++                    RC_TRACE(0x00000001, ("Exception: %s",
++                      exception_name->as_C_string()));
++                    RC_TRACE(0x00000001, ("Message: %s",
++                      message_buffer));
++                    Thread::current()->clear_pending_exception();
++                    return false;
++                  } 
++
++                }
++              }
++            }
++          } 
++        }
++        vf = vf->sender();
++      }
+     }
++
++    // Advance to next thread
++    java_thread = java_thread->next();
+   }
+ 
+   return true;
+ }
+ 
++bool VM_RedefineClasses::check_method(methodOop method) {
+ 
+-// Rewrite constant pool references in the specific method. This code
+-// was adapted from Rewriter::rewrite_method().
+-void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method,
+-       methodHandle *new_method_p, TRAPS) {
+ 
+-  *new_method_p = methodHandle();  // default is no new method
++  return true;
++}
+ 
+-  // We cache a pointer to the bytecodes here in code_base. If GC
+-  // moves the methodOop, then the bytecodes will also move which
+-  // will likely cause a crash. We create a No_Safepoint_Verifier
+-  // object to detect whether we pass a possible safepoint in this
+-  // code block.
+-  No_Safepoint_Verifier nsv;
++// Warning: destroys redefinition level values of klasses.
++bool VM_RedefineClasses::check_loaded_methods() {
+ 
+-  // Bytecodes and their length
+-  address code_base = method->code_base();
+-  int code_length = method->code_size();
++  class CheckLoadedMethodsClosure : public ObjectClosure {
+ 
+-  int bc_length;
+-  for (int bci = 0; bci < code_length; bci += bc_length) {
+-    address bcp = code_base + bci;
+-    Bytecodes::Code c = (Bytecodes::Code)(*bcp);
++  private:
++    
++    bool _result;
++    GrowableArray<klassOop> *_dangerous_klasses;
+ 
+-    bc_length = Bytecodes::length_for(c);
+-    if (bc_length == 0) {
+-      // More complicated bytecodes report a length of zero so
+-      // we have to try again a slightly different way.
+-      bc_length = Bytecodes::length_at(method(), bcp);
++  public:
++    CheckLoadedMethodsClosure(GrowableArray<klassOop> *dangerous_klasses) {
++      _result = true;
++      _dangerous_klasses = dangerous_klasses;
+     }
+ 
+-    assert(bc_length != 0, "impossible bytecode length");
++    bool result() {
++      return _result;
++    }
+ 
+-    switch (c) {
+-      case Bytecodes::_ldc:
+-      {
+-        int cp_index = *(bcp + 1);
+-        int new_index = find_new_index(cp_index);
++    bool is_class_dangerous(klassOop k) {
++      return k->klass_part()->newest_version()->klass_part()->check_redefinition_flag(Klass::RemoveSuperType);
++    }
+ 
+-        if (StressLdcRewrite && new_index == 0) {
+-          // If we are stressing ldc -> ldc_w rewriting, then we
+-          // always need a new_index value.
+-          new_index = cp_index;
+-        }
+-        if (new_index != 0) {
+-          // the original index is mapped so we have more work to do
+-          if (!StressLdcRewrite && new_index <= max_jubyte) {
+-            // The new value can still use ldc instead of ldc_w
+-            // unless we are trying to stress ldc -> ldc_w rewriting
+-            RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-              ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
+-              bcp, cp_index, new_index));
+-            *(bcp + 1) = new_index;
+-          } else {
+-            RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-              ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d",
+-              Bytecodes::name(c), bcp, cp_index, new_index));
+-            // the new value needs ldc_w instead of ldc
+-            u_char inst_buffer[4]; // max instruction size is 4 bytes
+-            bcp = (address)inst_buffer;
+-            // construct new instruction sequence
+-            *bcp = Bytecodes::_ldc_w;
+-            bcp++;
+-            // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w.
+-            // See comment below for difference between put_Java_u2()
+-            // and put_native_u2().
+-            Bytes::put_Java_u2(bcp, new_index);
+-
+-            Relocator rc(method, NULL /* no RelocatorListener needed */);
+-            methodHandle m;
+-            {
+-              Pause_No_Safepoint_Verifier pnsv(&nsv);
+-
+-              // ldc is 2 bytes and ldc_w is 3 bytes
+-              m = rc.insert_space_at(bci, 3, inst_buffer, THREAD);
+-              if (m.is_null() || HAS_PENDING_EXCEPTION) {
+-                guarantee(false, "insert_space_at() failed");
++    bool can_be_affected(instanceKlass *klass) {
++
++      constantPoolOop cp = klass->constants();
++
++      Thread *THREAD = Thread::current();
++      klassOop k;
++      Symbol* symbol;
++
++      for (int i=1; i<cp->length(); i++) {
++        jbyte tag = cp->tag_at(i).value();
++        switch(tag) {
++          case JVM_CONSTANT_Long:
++          case JVM_CONSTANT_Double:
++            i++;
++            break;
++
++          case JVM_CONSTANT_Utf8:
++          case JVM_CONSTANT_Unicode:
++          case JVM_CONSTANT_Integer:
++          case JVM_CONSTANT_Float:
++          case JVM_CONSTANT_String:
++          case JVM_CONSTANT_Fieldref:
++          case JVM_CONSTANT_Methodref:
++          case JVM_CONSTANT_InterfaceMethodref:
++          case JVM_CONSTANT_ClassIndex:
++          case JVM_CONSTANT_UnresolvedString:
++          case JVM_CONSTANT_StringIndex:
++          case JVM_CONSTANT_UnresolvedClassInError:
++          case JVM_CONSTANT_Object:
++            // do nothing
++            break;
++
++          case JVM_CONSTANT_Class:
++            k = cp->klass_at(i, CHECK_(true));
++            if (is_class_dangerous(k)) {
++              RC_TRACE(0x00000002, ("Class %s is potentially affected, because at cp[%d] references class %s",
++                klass->name()->as_C_string(),
++                i,
++                k->klass_part()->name()->as_C_string()));
++              return true;
++            }
++            break;
++          
++          case JVM_CONSTANT_NameAndType:
++            symbol = cp->symbol_at(cp->signature_ref_index_at(i));
++            if (symbol->byte_at(0) == '(') {
++              // This must be a method
++              SignatureStream signatureStream(symbol);
++              while (true) {
++
++                if (signatureStream.is_array()) {
++                  Symbol* cur_signature = signatureStream.as_symbol(Thread::current());
++                  if (is_type_signature_dangerous(cur_signature)) {
++                    return true;
++                  }
++                } else if (signatureStream.is_object()) {
++                  if (is_symbol_dangerous(signatureStream.as_symbol(Thread::current()))) {
++                    return true;
++                  }
++                } 
++
++                if (signatureStream.at_return_type()) {
++                  break;
++                }
++
++                signatureStream.next();
+               }
++
++            } else if (is_type_signature_dangerous(symbol)) {
++              return true;
+             }
++            break;
+ 
+-            // return the new method so that the caller can update
+-            // the containing class
+-            *new_method_p = method = m;
+-            // switch our bytecode processing loop from the old method
+-            // to the new method
+-            code_base = method->code_base();
+-            code_length = method->code_size();
+-            bcp = code_base + bci;
+-            c = (Bytecodes::Code)(*bcp);
+-            bc_length = Bytecodes::length_for(c);
+-            assert(bc_length != 0, "sanity check");
+-          } // end we need ldc_w instead of ldc
+-        } // end if there is a mapped index
+-      } break;
+-
+-      // these bytecodes have a two-byte constant pool index
+-      case Bytecodes::_anewarray      : // fall through
+-      case Bytecodes::_checkcast      : // fall through
+-      case Bytecodes::_getfield       : // fall through
+-      case Bytecodes::_getstatic      : // fall through
+-      case Bytecodes::_instanceof     : // fall through
+-      case Bytecodes::_invokedynamic  : // fall through
+-      case Bytecodes::_invokeinterface: // fall through
+-      case Bytecodes::_invokespecial  : // fall through
+-      case Bytecodes::_invokestatic   : // fall through
+-      case Bytecodes::_invokevirtual  : // fall through
+-      case Bytecodes::_ldc_w          : // fall through
+-      case Bytecodes::_ldc2_w         : // fall through
+-      case Bytecodes::_multianewarray : // fall through
+-      case Bytecodes::_new            : // fall through
+-      case Bytecodes::_putfield       : // fall through
+-      case Bytecodes::_putstatic      :
+-      {
+-        address p = bcp + 1;
+-        int cp_index = Bytes::get_Java_u2(p);
+-        int new_index = find_new_index(cp_index);
+-        if (new_index != 0) {
+-          // the original index is mapped so update w/ new value
+-          RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-            ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
+-            bcp, cp_index, new_index));
+-          // Rewriter::rewrite_method() uses put_native_u2() in this
+-          // situation because it is reusing the constant pool index
+-          // location for a native index into the constantPoolCache.
+-          // Since we are updating the constant pool index prior to
+-          // verification and constantPoolCache initialization, we
+-          // need to keep the new index in Java byte order.
+-          Bytes::put_Java_u2(p, new_index);
++          case JVM_CONSTANT_UnresolvedClass:
++            symbol = cp->unresolved_klass_at(i);
++            if (is_symbol_dangerous(symbol)) {
++              return true;
++            }
++            break;
++
++          default:
++            ShouldNotReachHere();
++        }
++      }
++
++      return false;
++    }
++
++    bool is_type_signature_dangerous(Symbol* signature) {
++      // This must be a field type
++      if (FieldType::is_obj(signature)) {
++        Symbol* name = signature_to_class_name(signature);
++        if (is_symbol_dangerous(name)) {
++          return true;
++        }
++      } else if (FieldType::is_array(signature)) {
++        //jint dimension;
++        //Symbol* object_key;
++        FieldArrayInfo fd;
++        FieldType::get_array_info(signature, fd, Thread::current());
++        if (is_symbol_dangerous(fd.object_key())) {
++          return true;
+         }
+-      } break;
++      }
++      return false;
+     }
+-  } // end for each bytecode
+-} // end rewrite_cp_refs_in_method()
+ 
++    bool is_symbol_dangerous(Symbol* symbol) {
++      for (int i=0; i<_dangerous_klasses->length(); i++) {
++        if(_dangerous_klasses->at(i)->klass_part()->name() == symbol) {
++          RC_TRACE(0x00000002, ("Found constant pool index %d references class %s",
++            i,
++            symbol->as_C_string()));
++          return true;
++        }
++      }
++      return false;
++    }
++
++    virtual void do_object(oop obj) {
++
++      if (!_result) return;
+ 
+-// Rewrite constant pool references in the class_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
+-       instanceKlassHandle scratch_class, TRAPS) {
++      klassOop klassObj = (klassOop)obj;
++      Thread *THREAD = Thread::current();
++
++      // We found an instance klass!
++      instanceKlass *klass = instanceKlass::cast(klassObj);
++      instanceKlassHandle handle(klassObj);
++
++      RC_TRACE(0x00000400, ("Check if verification is necessary for class %s major_version=%d", handle->name()->as_C_string(), handle->major_version()));
++
++      if (!can_be_affected(klass)) {
++        RC_TRACE(0x00000400, ("Skipping verification of class %s major_version=%d", handle->name()->as_C_string(), handle->major_version()));
++        return;
++      }
++
++      if (handle->major_version() < Verifier::STACKMAP_ATTRIBUTE_MAJOR_VERSION) {
++        RC_TRACE(0x00000001, ("Failing because cannot verify class %s major_version=%d", handle->name()->as_C_string(), handle->major_version()));
++        _result = false;
++        return;
++      }
++
++      RC_TRACE(0x00000001, ("Verifying class %s", handle->name()->as_C_string()));
++
++      if (!Verifier::verify(handle, Verifier::NoException, true, false, Thread::current())) {
++        
++        RC_TRACE(0x00000001, ("Verification of class %s failed", handle->name()->as_C_string()));
++        //Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
++        //RC_TRACE(0x00000002, ("exception when verifying class: '%s'", ex_name->as_C_string());
++        //PENDING_EXCEPTION->print();
++        CLEAR_PENDING_EXCEPTION;
++        _result = false;
++      } 
++
++      /*int method_count = klass->methods()->length();
++      for (int i=0; i<method_count; i++) {
++        methodOop cur_method = (methodOop)klass->methods()->obj_at(i);
++        if (!check_method(cur_method)) {
++          RC_TRACE(0x00000001, ("Failed to verify consistency of method %s of klass %s", cur_method->name()->as_C_string(), klass->name()->as_C_string());
++        }
++      }*/
++    }
++  };
+ 
+-  typeArrayHandle class_annotations(THREAD,
+-    scratch_class->class_annotations());
+-  if (class_annotations.is_null() || class_annotations->length() == 0) {
+-    // no class_annotations so nothing to do
+-    return true;
++  // TODO: Check bytecodes in case of interface => class or class => interface etc..
++
++  GrowableArray<klassOop> dangerous_klasses;
++  for (int i=0; i<_new_classes->length(); i++) {
++    instanceKlassHandle handle = _new_classes->at(i);
++    if (handle->check_redefinition_flag(Klass::RemoveSuperType)) {
++      dangerous_klasses.append(handle());
++    }
+   }
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("class_annotations length=%d", class_annotations->length()));
++  CheckLoadedMethodsClosure checkLoadedMethodsClosure(&dangerous_klasses);
++  Thread::current()->set_pretend_new_universe(true);
++  SystemDictionary::classes_do(&checkLoadedMethodsClosure);
++  Thread::current()->set_pretend_new_universe(false);
++
+ 
+-  int byte_i = 0;  // byte index into class_annotations
+-  return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
+-           THREAD);
++  return checkLoadedMethodsClosure.result();
+ }
+ 
++bool VM_RedefineClasses::check_type_consistency() {
+ 
+-// Rewrite constant pool references in an annotations typeArray. This
+-// "structure" is adapted from the RuntimeVisibleAnnotations_attribute
+-// that is described in section 4.8.15 of the 2nd-edition of the VM spec:
+-//
+-// annotations_typeArray {
+-//   u2 num_annotations;
+-//   annotation annotations[num_annotations];
+-// }
+-//
+-bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray(
+-       typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
++  Universe::set_verify_in_progress(true);
++
++  SystemDictionary::classes_do(calculate_type_check_information);
++  bool result = check_field_value_types();
++  SystemDictionary::classes_do(clear_type_check_information);
++  if (!result) {
++    RC_TRACE(0x00000001, ("Aborting redefinition because of wrong field or array element value!"));
++    Universe::set_verify_in_progress(false);
++    return false;
++  }
++
++  result = check_method_stacks();
++  if (!result) {
++    RC_TRACE(0x00000001, ("Aborting redefinition because of wrong value on the stack"));
++    Universe::set_verify_in_progress(false);
++    return false;
++  }
++
++  result = check_loaded_methods();
++  if (!result) {
++    RC_TRACE(0x00000001, ("Aborting redefinition because of wrong loaded method"));
++    Universe::set_verify_in_progress(false);
++    return false;
++  }
++
++  RC_TRACE(0x00000001, ("Verification passed => hierarchy change is valid!"));
++  Universe::set_verify_in_progress(false);
++  return true;
++}
++
++void VM_RedefineClasses::rollback() {
++  RC_TRACE(0x00000001, ("Rolling back redefinition!"));
++  SystemDictionary::rollback_redefinition();
+ 
+-  if ((byte_i_ref + 2) > annotations_typeArray->length()) {
+-    // not enough room for num_annotations field
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-      ("length() is too small for num_annotations field"));
+-    return false;
++  RC_TRACE(0x00000001, ("After rolling back system dictionary!"));
++  for (int i=0; i<_new_classes->length(); i++) {
++    SystemDictionary::remove_from_hierarchy(_new_classes->at(i));
+   }
+ 
+-  u2 num_annotations = Bytes::get_Java_u2((address)
+-                         annotations_typeArray->byte_at_addr(byte_i_ref));
+-  byte_i_ref += 2;
++  for (int i=0; i<_new_classes->length(); i++) {
++    instanceKlassHandle new_class = _new_classes->at(i);
++    new_class->set_redefining(false);
++    new_class->old_version()->klass_part()->set_new_version(NULL);
++    new_class->set_old_version(NULL);
++  }
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("num_annotations=%d", num_annotations));
++}
+ 
+-  int calc_num_annotations = 0;
+-  for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
+-    if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
+-           byte_i_ref, THREAD)) {
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("bad annotation_struct at %d", calc_num_annotations));
+-      // propagate failure back to caller
+-      return false;
++template <class T> void VM_RedefineClasses::do_oop_work(T* p) {
++  T heap_oop = oopDesc::load_heap_oop(p);
++  if (!oopDesc::is_null(heap_oop)) {
++    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
++    if (obj->is_instanceKlass()) {
++      klassOop klass = (klassOop)obj;
++      // DCEVM: note: can overwrite owner of old_klass constants pool with new_klass, so we need to fix it back later
++      if (klass->new_version() != NULL && klass->new_version()->klass_part()->is_redefining()) {
++        obj = klass->klass_part()->new_version();
++        oopDesc::encode_store_heap_oop_not_null(p, obj);
++      }
++    } else if (obj->blueprint()->newest_version() == SystemDictionary::Class_klass()->klass_part()->newest_version()) {
++      // update references to java.lang.Class to point to newest version. Only update references to non-primitive
++      // java.lang.Class instances.
++      klassOop klass_oop = java_lang_Class::as_klassOop(obj);
++      if (klass_oop != NULL) {
++        if (klass_oop->new_version() != NULL && klass_oop->new_version()->klass_part()->is_redefining()) {
++          obj = klass_oop->new_version()->java_mirror();
++        } else if (klass_oop->klass_part()->is_redefining()) {
++          obj = klass_oop->java_mirror();
++        }
++        oopDesc::encode_store_heap_oop_not_null(p, obj);
++
++
++        // FIXME: DCEVM: better implementation?
++        // Starting from JDK 7 java_mirror can be kept in the regular heap. Therefore, it is possible
++        // that new java_mirror is in the young generation whereas p is in tenured generation. In that
++        // case we need to run write barrier to make sure card table is properly updated. This will
++        // allow JVM to detect reference in tenured generation properly during young generation GC.
++        if (Universe::heap()->is_in_reserved(p)) {
++          if (GenCollectedHeap::heap()->is_in_young(obj)) {
++            GenRemSet* rs = GenCollectedHeap::heap()->rem_set();
++            assert(rs->rs_kind() == GenRemSet::CardTable, "Wrong rem set kind.");
++            CardTableRS* _rs = (CardTableRS*)rs;
++            _rs->inline_write_ref_field_gc(p, obj);
++          }
++        }
++      }
+     }
+   }
+-  assert(num_annotations == calc_num_annotations, "sanity check");
++}
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_annotations_typeArray()
++void VM_RedefineClasses::swap_marks(oop first, oop second) {
++  markOop first_mark = first->mark();
++  markOop second_mark = second->mark();
++  first->set_mark(second_mark);
++  second->set_mark(first_mark);
++}
+ 
++void VM_RedefineClasses::doit() {
++  Thread *thread = Thread::current();
+ 
+-// Rewrite constant pool references in the annotation struct portion of
+-// an annotations_typeArray. This "structure" is from section 4.8.15 of
+-// the 2nd-edition of the VM spec:
+-//
+-// struct annotation {
+-//   u2 type_index;
+-//   u2 num_element_value_pairs;
+-//   {
+-//     u2 element_name_index;
+-//     element_value value;
+-//   } element_value_pairs[num_element_value_pairs];
+-// }
+-//
+-bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct(
+-       typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
+-  if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) {
+-    // not enough room for smallest annotation_struct
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-      ("length() is too small for annotation_struct"));
+-    return false;
+-  }
++  RC_TRACE(0x00000001, ("Entering doit!"));
+ 
+-  u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray,
+-                    byte_i_ref, "mapped old type_index=%d", THREAD);
+ 
+-  u2 num_element_value_pairs = Bytes::get_Java_u2((address)
+-                                 annotations_typeArray->byte_at_addr(
+-                                 byte_i_ref));
+-  byte_i_ref += 2;
++  if ((_max_redefinition_flags & Klass::RemoveSuperType) != 0) {
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("type_index=%d  num_element_value_pairs=%d", type_index,
+-    num_element_value_pairs));
++    RC_TIMER_START(_timer_check_type);
+ 
+-  int calc_num_element_value_pairs = 0;
+-  for (; calc_num_element_value_pairs < num_element_value_pairs;
+-       calc_num_element_value_pairs++) {
+-    if ((byte_i_ref + 2) > annotations_typeArray->length()) {
+-      // not enough room for another element_name_index, let alone
+-      // the rest of another component
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("length() is too small for element_name_index"));
+-      return false;
++    if (!check_type_consistency()) {
++      // (tw) TODO: Rollback the class redefinition
++      rollback();
++      RC_TRACE(0x00000001, ("Detected type inconsistency!"));
++      _result = JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
++      RC_TIMER_STOP(_timer_check_type);
++      return;
+     }
+ 
+-    u2 element_name_index = rewrite_cp_ref_in_annotation_data(
+-                              annotations_typeArray, byte_i_ref,
+-                              "mapped old element_name_index=%d", THREAD);
++    RC_TIMER_STOP(_timer_check_type);
+ 
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-      ("element_name_index=%d", element_name_index));
++  } else {
++    RC_TRACE(0x00000001, ("No type narrowing => skipping check for type inconsistency"));
++  }
+ 
+-    if (!rewrite_cp_refs_in_element_value(annotations_typeArray,
+-           byte_i_ref, THREAD)) {
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("bad element_value at %d", calc_num_element_value_pairs));
+-      // propagate failure back to caller
+-      return false;
++  if (UseMethodForwardPoints) {
++    RC_TRACE(0x00000001, ("Check stack for forwarding methods to new version"));
++    method_forwarding();
++  }
++
++  if (UseSharedSpaces) {
++    // Sharing is enabled so we remap the shared readonly space to
++    // shared readwrite, private just in case we need to redefine
++    // a shared class. We do the remap during the doit() phase of
++    // the safepoint to be safer.
++    if (!CompactingPermGenGen::remap_shared_readonly_as_readwrite()) {
++      RC_TRACE(0x00000001, ("failed to remap shared readonly space to readwrite, private"));
++      _result = JVMTI_ERROR_INTERNAL;
++      return;
+     }
+-  } // end for each component
+-  assert(num_element_value_pairs == calc_num_element_value_pairs,
+-    "sanity check");
++  }
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_annotation_struct()
+-
+-
+-// Rewrite a constant pool reference at the current position in
+-// annotations_typeArray if needed. Returns the original constant
+-// pool reference if a rewrite was not needed or the new constant
+-// pool reference if a rewrite was needed.
+-u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data(
+-     typeArrayHandle annotations_typeArray, int &byte_i_ref,
+-     const char * trace_mesg, TRAPS) {
+-
+-  address cp_index_addr = (address)
+-    annotations_typeArray->byte_at_addr(byte_i_ref);
+-  u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr);
+-  u2 new_cp_index = find_new_index(old_cp_index);
+-  if (new_cp_index != 0) {
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index));
+-    Bytes::put_Java_u2(cp_index_addr, new_cp_index);
+-    old_cp_index = new_cp_index;
+-  }
+-  byte_i_ref += 2;
+-  return old_cp_index;
+-}
++  RC_TIMER_START(_timer_prepare_redefinition);
++  for (int i = 0; i < _new_classes->length(); i++) {
++    redefine_single_class(_new_classes->at(i), thread);
++  }
+ 
++  // Deoptimize all compiled code that depends on this class
++  flush_dependent_code(instanceKlassHandle(Thread::current(), (klassOop)NULL), Thread::current());
+ 
+-// Rewrite constant pool references in the element_value portion of an
+-// annotations_typeArray. This "structure" is from section 4.8.15.1 of
+-// the 2nd-edition of the VM spec:
+-//
+-// struct element_value {
+-//   u1 tag;
+-//   union {
+-//     u2 const_value_index;
+-//     {
+-//       u2 type_name_index;
+-//       u2 const_name_index;
+-//     } enum_const_value;
+-//     u2 class_info_index;
+-//     annotation annotation_value;
+-//     struct {
+-//       u2 num_values;
+-//       element_value values[num_values];
+-//     } array_value;
+-//   } value;
+-// }
+-//
+-bool VM_RedefineClasses::rewrite_cp_refs_in_element_value(
+-       typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) {
++  // Adjust constantpool caches and vtables for all classes
++  // that reference methods of the evolved class.
++  SystemDictionary::classes_do(adjust_cpool_cache, Thread::current());
+ 
+-  if ((byte_i_ref + 1) > annotations_typeArray->length()) {
+-    // not enough room for a tag let alone the rest of an element_value
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-      ("length() is too small for a tag"));
+-    return false;
+-  }
++  RC_TIMER_STOP(_timer_prepare_redefinition);
++  RC_TIMER_START(_timer_redefinition);
+ 
+-  u1 tag = annotations_typeArray->byte_at(byte_i_ref);
+-  byte_i_ref++;
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag));
+-
+-  switch (tag) {
+-    // These BaseType tag values are from Table 4.2 in VM spec:
+-    case 'B':  // byte
+-    case 'C':  // char
+-    case 'D':  // double
+-    case 'F':  // float
+-    case 'I':  // int
+-    case 'J':  // long
+-    case 'S':  // short
+-    case 'Z':  // boolean
+-
+-    // The remaining tag values are from Table 4.8 in the 2nd-edition of
+-    // the VM spec:
+-    case 's':
+-    {
+-      // For the above tag values (including the BaseType values),
+-      // value.const_value_index is right union field.
++    class ChangePointersOopClosure : public OopClosure {
++      virtual void do_oop(oop* o) {
++        do_oop_work(o);
++      }
+ 
+-      if ((byte_i_ref + 2) > annotations_typeArray->length()) {
+-        // not enough room for a const_value_index
+-        RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-          ("length() is too small for a const_value_index"));
+-        return false;
++      virtual void do_oop(narrowOop* o) {
++        do_oop_work(o);
+       }
++    };
+ 
+-      u2 const_value_index = rewrite_cp_ref_in_annotation_data(
+-                               annotations_typeArray, byte_i_ref,
+-                               "mapped old const_value_index=%d", THREAD);
++    class ChangePointersObjectClosure : public ObjectClosure {
+ 
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("const_value_index=%d", const_value_index));
+-    } break;
++    private:
+ 
+-    case 'e':
+-    {
+-      // for the above tag value, value.enum_const_value is right union field
++      OopClosure *_closure;
++      bool _needs_instance_update;
++      GrowableArray<oop> *_updated_oops;
+ 
+-      if ((byte_i_ref + 4) > annotations_typeArray->length()) {
+-        // not enough room for a enum_const_value
+-        RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-          ("length() is too small for a enum_const_value"));
+-        return false;
+-      }
++    public:
++      ChangePointersObjectClosure(OopClosure *closure) : _closure(closure), _needs_instance_update(false), _updated_oops(NULL) {}
+ 
+-      u2 type_name_index = rewrite_cp_ref_in_annotation_data(
+-                             annotations_typeArray, byte_i_ref,
+-                             "mapped old type_name_index=%d", THREAD);
++      bool needs_instance_update() {
++        return _needs_instance_update;
++      }
+ 
+-      u2 const_name_index = rewrite_cp_ref_in_annotation_data(
+-                              annotations_typeArray, byte_i_ref,
+-                              "mapped old const_name_index=%d", THREAD);
++      GrowableArray<oop> *updated_oops() { return _updated_oops; }
+ 
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("type_name_index=%d  const_name_index=%d", type_name_index,
+-        const_name_index));
+-    } break;
++      virtual void do_object(oop obj) {
++        if (!obj->is_instanceKlass()) {
++          obj->oop_iterate(_closure);
++          
++          if (obj->blueprint()->is_redefining()) {
+ 
+-    case 'c':
+-    {
+-      // for the above tag value, value.class_info_index is right union field
++            if (obj->blueprint()->check_redefinition_flag(Klass::HasInstanceTransformer)) {
++              if (_updated_oops == NULL) {
++                _updated_oops = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(100, true);
++              }
++              _updated_oops->append(obj);
++            }
+ 
+-      if ((byte_i_ref + 2) > annotations_typeArray->length()) {
+-        // not enough room for a class_info_index
+-        RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-          ("length() is too small for a class_info_index"));
+-        return false;
+-      }
++            if(obj->blueprint()->update_information() != NULL || obj->is_perm()) {
+ 
+-      u2 class_info_index = rewrite_cp_ref_in_annotation_data(
+-                              annotations_typeArray, byte_i_ref,
+-                              "mapped old class_info_index=%d", THREAD);
++              assert(obj->blueprint()->old_version() != NULL, "must have old version");
++              obj->set_klass_no_check(obj->blueprint()->old_version());
+ 
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("class_info_index=%d", class_info_index));
+-    } break;
++              if (obj->size() != obj->size_given_klass(obj->blueprint()->new_version()->klass_part()) || obj->is_perm()) {
++                // We need an instance update => set back to old klass
++                _needs_instance_update = true;
+ 
+-    case '@':
+-      // For the above tag value, value.attr_value is the right union
+-      // field. This is a nested annotation.
+-      if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
+-             byte_i_ref, THREAD)) {
+-        // propagate failure back to caller
+-        return false;
+-      }
+-      break;
++              } else {
++                MarkSweep::update_fields(obj, obj);
++                assert(obj->blueprint()->is_redefining(), "update fields resets the klass");
++              }
++            }
++          }
+ 
+-    case '[':
+-    {
+-      if ((byte_i_ref + 2) > annotations_typeArray->length()) {
+-        // not enough room for a num_values field
+-        RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-          ("length() is too small for a num_values field"));
+-        return false;
+-      }
+-
+-      // For the above tag value, value.array_value is the right union
+-      // field. This is an array of nested element_value.
+-      u2 num_values = Bytes::get_Java_u2((address)
+-                        annotations_typeArray->byte_at_addr(byte_i_ref));
+-      byte_i_ref += 2;
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values));
+-
+-      int calc_num_values = 0;
+-      for (; calc_num_values < num_values; calc_num_values++) {
+-        if (!rewrite_cp_refs_in_element_value(
+-               annotations_typeArray, byte_i_ref, THREAD)) {
+-          RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-            ("bad nested element_value at %d", calc_num_values));
+-          // propagate failure back to caller
+-          return false;
++        } else {
++          instanceKlass *klass = instanceKlass::cast((klassOop)obj);
++          if (klass->is_redefining()) {
++            // DCEVM: We need to restorte constants pool owner which was updated by do_oop_work
++            instanceKlass* old_klass = instanceKlass::cast(klass->old_version());
++            old_klass->constants()->set_pool_holder(klass->old_version());
++ 
++            // Initialize the new class! Special static initialization that does not execute the
++            // static constructor but copies static field values from the old class if name
++            // and signature of a static field match.
++            klass->initialize_redefined_class();
++          }
++          // idubrov: FIXME: we probably don't need that since oop's will be visited in a regular way...
++          // idubrov: need to check if there is a test to verify that fields referencing class being updated
++          // idubrov: will get new version of that class
++          //klass->iterate_static_fields(_closure);
+         }
+       }
+-      assert(num_values == calc_num_values, "sanity check");
+-    } break;
++    };
+ 
+-    default:
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag));
+-      return false;
+-  } // end decode tag field
++    ChangePointersOopClosure oopClosure;
++    ChangePointersObjectClosure objectClosure(&oopClosure);
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_element_value()
++    {
++      SharedHeap::heap()->gc_prologue(true);
++      Universe::root_oops_do(&oopClosure);
++      Universe::heap()->object_iterate(&objectClosure);
++      SharedHeap::heap()->gc_epilogue(false);
++    }
+ 
++    // Swap marks to have same hashcodes
++    for (int i=0; i<_new_classes->length(); i++) {
++      swap_marks(_new_classes->at(i)(), _new_classes->at(i)->old_version());
++      swap_marks(_new_classes->at(i)->java_mirror(), _new_classes->at(i)->old_version()->java_mirror());
++    }
+ 
+-// Rewrite constant pool references in a fields_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
+-       instanceKlassHandle scratch_class, TRAPS) {
++    _updated_oops = objectClosure.updated_oops();
+ 
+-  objArrayHandle fields_annotations(THREAD,
+-    scratch_class->fields_annotations());
++  if (objectClosure.needs_instance_update()){
+ 
+-  if (fields_annotations.is_null() || fields_annotations->length() == 0) {
+-    // no fields_annotations so nothing to do
+-    return true;
++    // Do a full garbage collection to update the instance sizes accordingly
++    RC_TRACE(0x00000001, ("Before performing full GC!"));
++    Universe::set_redefining_gc_run(true);
++    JvmtiGCMarker jgcm;
++    notify_gc_begin(true);
++    Universe::heap()->collect_as_vm_thread(GCCause::_heap_inspection);
++    notify_gc_end();
++    Universe::set_redefining_gc_run(false);
++    RC_TRACE(0x00000001, ("GC done!"));
+   }
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("fields_annotations length=%d", fields_annotations->length()));
+-
+-  for (int i = 0; i < fields_annotations->length(); i++) {
+-    typeArrayHandle field_annotations(THREAD,
+-      (typeArrayOop)fields_annotations->obj_at(i));
+-    if (field_annotations.is_null() || field_annotations->length() == 0) {
+-      // this field does not have any annotations so skip it
+-      continue;
+-    }
+ 
+-    int byte_i = 0;  // byte index into field_annotations
+-    if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i,
+-           THREAD)) {
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("bad field_annotations at %d", i));
+-      // propagate failure back to caller
+-      return false;
++  if (RC_TRACE_ENABLED(0x00000001)) {
++    if (_updated_oops != NULL) {
++      RC_TRACE(0x00000001, ("%d object(s) updated!", _updated_oops->length()));
++    } else {
++      RC_TRACE(0x00000001, ("No objects updated!"));
+     }
+   }
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_fields_annotations()
+-
++  // Unmark klassOops as "redefining"
++  for (int i=0; i<_new_classes->length(); i++) {
++    klassOop cur = _new_classes->at(i)();
++    _new_classes->at(i)->set_redefining(false);
++    _new_classes->at(i)->clear_update_information();
++    _new_classes->at(i)->update_supers_to_newest_version();
+ 
+-// Rewrite constant pool references in a methods_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
+-       instanceKlassHandle scratch_class, TRAPS) {
++    if (((instanceKlass *)cur->klass_part()->old_version()->klass_part())->array_klasses() != NULL) {
++      update_array_classes_to_newest_version(((instanceKlass *)cur->klass_part()->old_version()->klass_part())->array_klasses());
+ 
+-  objArrayHandle methods_annotations(THREAD,
+-    scratch_class->methods_annotations());
++      // Transfer the array classes, otherwise we might get cast exceptions when casting array types.
++      ((instanceKlass*)cur->klass_part())->set_array_klasses(((instanceKlass*)cur->klass_part()->old_version()->klass_part())->array_klasses());
+ 
+-  if (methods_annotations.is_null() || methods_annotations->length() == 0) {
+-    // no methods_annotations so nothing to do
+-    return true;
+-  }
+-
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("methods_annotations length=%d", methods_annotations->length()));
+-
+-  for (int i = 0; i < methods_annotations->length(); i++) {
+-    typeArrayHandle method_annotations(THREAD,
+-      (typeArrayOop)methods_annotations->obj_at(i));
+-    if (method_annotations.is_null() || method_annotations->length() == 0) {
+-      // this method does not have any annotations so skip it
+-      continue;
++      oop new_mirror = _new_classes->at(i)->java_mirror();
++      oop old_mirror = _new_classes->at(i)->old_version()->java_mirror();
++      java_lang_Class::set_array_klass(new_mirror, java_lang_Class::array_klass(old_mirror));
+     }
++  }
+ 
+-    int byte_i = 0;  // byte index into method_annotations
+-    if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i,
+-           THREAD)) {
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("bad method_annotations at %d", i));
+-      // propagate failure back to caller
+-      return false;
+-    }
++  for (int i=T_BOOLEAN; i<=T_LONG; i++) {
++    update_array_classes_to_newest_version(Universe::typeArrayKlassObj((BasicType)i));
+   }
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_methods_annotations()
++  // Disable any dependent concurrent compilations
++  SystemDictionary::notice_modification();
++
++  // Set flag indicating that some invariants are no longer true.
++  // See jvmtiExport.hpp for detailed explanation.
++  JvmtiExport::set_has_redefined_a_class();
+ 
++  // Clean up caches in the compiler interface and compiler threads
++  CompileBroker::cleanup_after_redefinition();
+ 
+-// Rewrite constant pool references in a methods_parameter_annotations
+-// field. This "structure" is adapted from the
+-// RuntimeVisibleParameterAnnotations_attribute described in section
+-// 4.8.17 of the 2nd-edition of the VM spec:
+-//
+-// methods_parameter_annotations_typeArray {
+-//   u1 num_parameters;
+-//   {
+-//     u2 num_annotations;
+-//     annotation annotations[num_annotations];
+-//   } parameter_annotations[num_parameters];
+-// }
+-//
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations(
+-       instanceKlassHandle scratch_class, TRAPS) {
++#ifdef ASSERT
+ 
+-  objArrayHandle methods_parameter_annotations(THREAD,
+-    scratch_class->methods_parameter_annotations());
++  // Universe::verify();
++  // JNIHandles::verify();
+ 
+-  if (methods_parameter_annotations.is_null()
+-      || methods_parameter_annotations->length() == 0) {
+-    // no methods_parameter_annotations so nothing to do
+-    return true;
+-  }
++  SystemDictionary::classes_do(check_class, thread);
++#endif
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("methods_parameter_annotations length=%d",
+-    methods_parameter_annotations->length()));
++  update_active_methods();
++  RC_TIMER_STOP(_timer_redefinition);
+ 
+-  for (int i = 0; i < methods_parameter_annotations->length(); i++) {
+-    typeArrayHandle method_parameter_annotations(THREAD,
+-      (typeArrayOop)methods_parameter_annotations->obj_at(i));
+-    if (method_parameter_annotations.is_null()
+-        || method_parameter_annotations->length() == 0) {
+-      // this method does not have any parameter annotations so skip it
+-      continue;
+-    }
++}
+ 
+-    if (method_parameter_annotations->length() < 1) {
+-      // not enough room for a num_parameters field
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("length() is too small for a num_parameters field at %d", i));
+-      return false;
+-    }
++void VM_RedefineClasses::update_array_classes_to_newest_version(klassOop smallest_dimension) {
+ 
+-    int byte_i = 0;  // byte index into method_parameter_annotations
++  arrayKlass *curArrayKlass = arrayKlass::cast(smallest_dimension);
++  assert(curArrayKlass->lower_dimension() == NULL, "argument must be smallest dimension");
+ 
+-    u1 num_parameters = method_parameter_annotations->byte_at(byte_i);
+-    byte_i++;
+ 
+-    RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-      ("num_parameters=%d", num_parameters));
++  while (curArrayKlass != NULL) {
++    klassOop higher_dimension = curArrayKlass->higher_dimension();
++    klassOop lower_dimension = curArrayKlass->lower_dimension();
++    curArrayKlass->update_supers_to_newest_version();
+ 
+-    int calc_num_parameters = 0;
+-    for (; calc_num_parameters < num_parameters; calc_num_parameters++) {
+-      if (!rewrite_cp_refs_in_annotations_typeArray(
+-             method_parameter_annotations, byte_i, THREAD)) {
+-        RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-          ("bad method_parameter_annotations at %d", calc_num_parameters));
+-        // propagate failure back to caller
+-        return false;
+-      }
++    curArrayKlass = NULL;
++    if (higher_dimension != NULL) {
++      curArrayKlass = arrayKlass::cast(higher_dimension);
+     }
+-    assert(num_parameters == calc_num_parameters, "sanity check");
+   }
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_methods_parameter_annotations()
++}
+ 
++void VM_RedefineClasses::doit_epilogue() {
+ 
+-// Rewrite constant pool references in a methods_default_annotations
+-// field. This "structure" is adapted from the AnnotationDefault_attribute
+-// that is described in section 4.8.19 of the 2nd-edition of the VM spec:
+-//
+-// methods_default_annotations_typeArray {
+-//   element_value default_value;
+-// }
+-//
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations(
+-       instanceKlassHandle scratch_class, TRAPS) {
++  RC_TIMER_START(_timer_vm_op_epilogue);
+ 
+-  objArrayHandle methods_default_annotations(THREAD,
+-    scratch_class->methods_default_annotations());
++  unlock_threads();
+ 
+-  if (methods_default_annotations.is_null()
+-      || methods_default_annotations->length() == 0) {
+-    // no methods_default_annotations so nothing to do
+-    return true;
+-  }
++  ResourceMark mark;
+ 
+-  RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-    ("methods_default_annotations length=%d",
+-    methods_default_annotations->length()));
++  VM_GC_Operation::doit_epilogue();
++  RC_TRACE(0x00000001, ("GC Operation epilogue finished! "));
+ 
+-  for (int i = 0; i < methods_default_annotations->length(); i++) {
+-    typeArrayHandle method_default_annotations(THREAD,
+-      (typeArrayOop)methods_default_annotations->obj_at(i));
+-    if (method_default_annotations.is_null()
+-        || method_default_annotations->length() == 0) {
+-      // this method does not have any default annotations so skip it
+-      continue;
++  GrowableArray<methodHandle> instanceTransformerMethods;
++
++  // Call static transformers
++  for (int i=0; i<_new_classes->length(); i++) {
++    
++    instanceKlassHandle klass = _new_classes->at(i);
++
++    // Transfer init state
++    if (klass->old_version() != NULL) {
++      instanceKlass::ClassState state = instanceKlass::cast(klass->old_version())->init_state();
++      if (state > instanceKlass::linked) {
++        klass->initialize(Thread::current());
++      }
+     }
++    
++    // Find instance transformer method
+ 
+-    int byte_i = 0;  // byte index into method_default_annotations
++    if (klass->check_redefinition_flag(Klass::HasInstanceTransformer)) {
+ 
+-    if (!rewrite_cp_refs_in_element_value(
+-           method_default_annotations, byte_i, THREAD)) {
+-      RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+-        ("bad default element_value at %d", i));
+-      // propagate failure back to caller
+-      return false;
++      RC_TRACE(0x00008000, ("Call instance transformer of %s instance", klass->name()->as_C_string()));
++      klassOop cur_klass = klass();
++      while (cur_klass != NULL) {
++        methodOop method = ((instanceKlass*)cur_klass->klass_part())->find_method(vmSymbols::transformer_name(), vmSymbols::void_method_signature());
++        if (method != NULL) {
++          methodHandle instanceTransformerMethod(method);
++          instanceTransformerMethods.append(instanceTransformerMethod);
++          break;
++        } else {
++          cur_klass = cur_klass->klass_part()->super();
++        }
++      }
++      assert(cur_klass != NULL, "must have instance transformer method");
++    } else {
++      instanceTransformerMethods.append(methodHandle(Thread::current(), NULL));
+     }
+   }
+ 
+-  return true;
+-} // end rewrite_cp_refs_in_methods_default_annotations()
+ 
++  // Call instance transformers
++  if (_updated_oops != NULL) {
+ 
+-// Rewrite constant pool references in the method's stackmap table.
+-// These "structures" are adapted from the StackMapTable_attribute that
+-// is described in section 4.8.4 of the 6.0 version of the VM spec
+-// (dated 2005.10.26):
+-// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
+-//
+-// stack_map {
+-//   u2 number_of_entries;
+-//   stack_map_frame entries[number_of_entries];
+-// }
+-//
+-void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table(
+-       methodHandle method, TRAPS) {
+-
+-  if (!method->has_stackmap_table()) {
+-    return;
+-  }
+-
+-  typeArrayOop stackmap_data = method->stackmap_data();
+-  address stackmap_p = (address)stackmap_data->byte_at_addr(0);
+-  address stackmap_end = stackmap_p + stackmap_data->length();
+-
+-  assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries");
+-  u2 number_of_entries = Bytes::get_Java_u2(stackmap_p);
+-  stackmap_p += 2;
+-
+-  RC_TRACE_WITH_THREAD(0x04000000, THREAD,
+-    ("number_of_entries=%u", number_of_entries));
+-
+-  // walk through each stack_map_frame
+-  u2 calc_number_of_entries = 0;
+-  for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) {
+-    // The stack_map_frame structure is a u1 frame_type followed by
+-    // 0 or more bytes of data:
+-    //
+-    // union stack_map_frame {
+-    //   same_frame;
+-    //   same_locals_1_stack_item_frame;
+-    //   same_locals_1_stack_item_frame_extended;
+-    //   chop_frame;
+-    //   same_frame_extended;
+-    //   append_frame;
+-    //   full_frame;
+-    // }
+-
+-    assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type");
+-    // The Linux compiler does not like frame_type to be u1 or u2. It
+-    // issues the following warning for the first if-statement below:
+-    //
+-    // "warning: comparison is always true due to limited range of data type"
+-    //
+-    u4 frame_type = *stackmap_p;
+-    stackmap_p++;
+-
+-    // same_frame {
+-    //   u1 frame_type = SAME; /* 0-63 */
+-    // }
+-    if (frame_type >= 0 && frame_type <= 63) {
+-      // nothing more to do for same_frame
+-    }
+-
+-    // same_locals_1_stack_item_frame {
+-    //   u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */
+-    //   verification_type_info stack[1];
+-    // }
+-    else if (frame_type >= 64 && frame_type <= 127) {
+-      rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
+-        calc_number_of_entries, frame_type, THREAD);
+-    }
+-
+-    // reserved for future use
+-    else if (frame_type >= 128 && frame_type <= 246) {
+-      // nothing more to do for reserved frame_types
+-    }
+-
+-    // same_locals_1_stack_item_frame_extended {
+-    //   u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */
+-    //   u2 offset_delta;
+-    //   verification_type_info stack[1];
+-    // }
+-    else if (frame_type == 247) {
+-      stackmap_p += 2;
+-      rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
+-        calc_number_of_entries, frame_type, THREAD);
+-    }
+-
+-    // chop_frame {
+-    //   u1 frame_type = CHOP; /* 248-250 */
+-    //   u2 offset_delta;
+-    // }
+-    else if (frame_type >= 248 && frame_type <= 250) {
+-      stackmap_p += 2;
+-    }
+-
+-    // same_frame_extended {
+-    //   u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/
+-    //   u2 offset_delta;
+-    // }
+-    else if (frame_type == 251) {
+-      stackmap_p += 2;
+-    }
+-
+-    // append_frame {
+-    //   u1 frame_type = APPEND; /* 252-254 */
+-    //   u2 offset_delta;
+-    //   verification_type_info locals[frame_type - 251];
+-    // }
+-    else if (frame_type >= 252 && frame_type <= 254) {
+-      assert(stackmap_p + 2 <= stackmap_end,
+-        "no room for offset_delta");
+-      stackmap_p += 2;
+-      u1 len = frame_type - 251;
+-      for (u1 i = 0; i < len; i++) {
+-        rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
+-          calc_number_of_entries, frame_type, THREAD);
+-      }
+-    }
+-
+-    // full_frame {
+-    //   u1 frame_type = FULL_FRAME; /* 255 */
+-    //   u2 offset_delta;
+-    //   u2 number_of_locals;
+-    //   verification_type_info locals[number_of_locals];
+-    //   u2 number_of_stack_items;
+-    //   verification_type_info stack[number_of_stack_items];
+-    // }
+-    else if (frame_type == 255) {
+-      assert(stackmap_p + 2 + 2 <= stackmap_end,
+-        "no room for smallest full_frame");
+-      stackmap_p += 2;
+-
+-      u2 number_of_locals = Bytes::get_Java_u2(stackmap_p);
+-      stackmap_p += 2;
+-
+-      for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) {
+-        rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
+-          calc_number_of_entries, frame_type, THREAD);
+-      }
+-
+-      // Use the largest size for the number_of_stack_items, but only get
+-      // the right number of bytes.
+-      u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p);
+-      stackmap_p += 2;
+-
+-      for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) {
+-        rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
+-          calc_number_of_entries, frame_type, THREAD);
+-      }
+-    }
+-  } // end while there is a stack_map_frame
+-  assert(number_of_entries == calc_number_of_entries, "sanity check");
+-} // end rewrite_cp_refs_in_stack_map_table()
+-
+-
+-// Rewrite constant pool references in the verification type info
+-// portion of the method's stackmap table. These "structures" are
+-// adapted from the StackMapTable_attribute that is described in
+-// section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26):
+-// file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
+-//
+-// The verification_type_info structure is a u1 tag followed by 0 or
+-// more bytes of data:
+-//
+-// union verification_type_info {
+-//   Top_variable_info;
+-//   Integer_variable_info;
+-//   Float_variable_info;
+-//   Long_variable_info;
+-//   Double_variable_info;
+-//   Null_variable_info;
+-//   UninitializedThis_variable_info;
+-//   Object_variable_info;
+-//   Uninitialized_variable_info;
+-// }
+-//
+-void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info(
+-       address& stackmap_p_ref, address stackmap_end, u2 frame_i,
+-       u1 frame_type, TRAPS) {
+-
+-  assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag");
+-  u1 tag = *stackmap_p_ref;
+-  stackmap_p_ref++;
+-
+-  switch (tag) {
+-  // Top_variable_info {
+-  //   u1 tag = ITEM_Top; /* 0 */
+-  // }
+-  // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top
+-  case 0:  // fall through
+-
+-  // Integer_variable_info {
+-  //   u1 tag = ITEM_Integer; /* 1 */
+-  // }
+-  case ITEM_Integer:  // fall through
+-
+-  // Float_variable_info {
+-  //   u1 tag = ITEM_Float; /* 2 */
+-  // }
+-  case ITEM_Float:  // fall through
+-
+-  // Double_variable_info {
+-  //   u1 tag = ITEM_Double; /* 3 */
+-  // }
+-  case ITEM_Double:  // fall through
+-
+-  // Long_variable_info {
+-  //   u1 tag = ITEM_Long; /* 4 */
+-  // }
+-  case ITEM_Long:  // fall through
+-
+-  // Null_variable_info {
+-  //   u1 tag = ITEM_Null; /* 5 */
+-  // }
+-  case ITEM_Null:  // fall through
+-
+-  // UninitializedThis_variable_info {
+-  //   u1 tag = ITEM_UninitializedThis; /* 6 */
+-  // }
+-  case ITEM_UninitializedThis:
+-    // nothing more to do for the above tag types
+-    break;
++    for (int i=0; i<_updated_oops->length(); i++) {
++      assert(_updated_oops->at(i) != NULL, "must not be null!");
++      Handle cur(_updated_oops->at(i));
++      instanceKlassHandle klass(cur->klass());
+ 
+-  // Object_variable_info {
+-  //   u1 tag = ITEM_Object; /* 7 */
+-  //   u2 cpool_index;
+-  // }
+-  case ITEM_Object:
+-  {
+-    assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index");
+-    u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref);
+-    u2 new_cp_index = find_new_index(cpool_index);
+-    if (new_cp_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x04000000, THREAD,
+-        ("mapped old cpool_index=%d", cpool_index));
+-      Bytes::put_Java_u2(stackmap_p_ref, new_cp_index);
+-      cpool_index = new_cp_index;
+-    }
+-    stackmap_p_ref += 2;
+-
+-    RC_TRACE_WITH_THREAD(0x04000000, THREAD,
+-      ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i,
+-      frame_type, cpool_index));
+-  } break;
+-
+-  // Uninitialized_variable_info {
+-  //   u1 tag = ITEM_Uninitialized; /* 8 */
+-  //   u2 offset;
+-  // }
+-  case ITEM_Uninitialized:
+-    assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset");
+-    stackmap_p_ref += 2;
+-    break;
++      if (klass->check_redefinition_flag(Klass::HasInstanceTransformer)) {
+ 
+-  default:
+-    RC_TRACE_WITH_THREAD(0x04000000, THREAD,
+-      ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag));
+-    ShouldNotReachHere();
+-    break;
+-  } // end switch (tag)
+-} // end rewrite_cp_refs_in_verification_type_info()
+-
+-
+-// Change the constant pool associated with klass scratch_class to
+-// scratch_cp. If shrink is true, then scratch_cp_length elements
+-// are copied from scratch_cp to a smaller constant pool and the
+-// smaller constant pool is associated with scratch_class.
+-void VM_RedefineClasses::set_new_constant_pool(
+-       instanceKlassHandle scratch_class, constantPoolHandle scratch_cp,
+-       int scratch_cp_length, TRAPS) {
+-  assert(scratch_cp->length() >= scratch_cp_length, "sanity check");
+-
+-  // scratch_cp is a merged constant pool and has enough space for a
+-  // worst case merge situation. We want to associate the minimum
+-  // sized constant pool with the klass to save space.
+-  constantPoolHandle smaller_cp(THREAD,
+-    oopFactory::new_constantPool(scratch_cp_length,
+-                                 oopDesc::IsUnsafeConc,
+-                                 THREAD));
+-  // preserve orig_length() value in the smaller copy
+-  int orig_length = scratch_cp->orig_length();
+-  assert(orig_length != 0, "sanity check");
+-  smaller_cp->set_orig_length(orig_length);
+-
+-  // attach klass to new constant pool
+-  // reference to the cp holder is needed for copy_operands()
+-  smaller_cp->set_pool_holder(scratch_class());
+-
+-  scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
+-  scratch_cp = smaller_cp;
+-  smaller_cp()->set_is_conc_safe(true);
+-
+-  // attach new constant pool to klass
+-  scratch_class->set_constants(scratch_cp());
+-
+-  int i;  // for portability
+-
+-  // update each field in klass to use new constant pool indices as needed
+-  for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) {
+-    jshort cur_index = fs.name_index();
+-    jshort new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("field-name_index change: %d to %d", cur_index, new_index));
+-      fs.set_name_index(new_index);
+-    }
+-    cur_index = fs.signature_index();
+-    new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("field-signature_index change: %d to %d", cur_index, new_index));
+-      fs.set_signature_index(new_index);
+-    }
+-    cur_index = fs.initval_index();
+-    new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("field-initval_index change: %d to %d", cur_index, new_index));
+-      fs.set_initval_index(new_index);
+-    }
+-    cur_index = fs.generic_signature_index();
+-    new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("field-generic_signature change: %d to %d", cur_index, new_index));
+-      fs.set_generic_signature_index(new_index);
+-    }
+-  } // end for each field
+-
+-  // Update constant pool indices in the inner classes info to use
+-  // new constant indices as needed. The inner classes info is a
+-  // quadruple:
+-  // (inner_class_info, outer_class_info, inner_name, inner_access_flags)
+-  InnerClassesIterator iter(scratch_class);
+-  for (; !iter.done(); iter.next()) {
+-    int cur_index = iter.inner_class_info_index();
+-    if (cur_index == 0) {
+-      continue;  // JVM spec. allows null inner class refs so skip it
+-    }
+-    int new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("inner_class_info change: %d to %d", cur_index, new_index));
+-      iter.set_inner_class_info_index(new_index);
+-    }
+-    cur_index = iter.outer_class_info_index();
+-    new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("outer_class_info change: %d to %d", cur_index, new_index));
+-      iter.set_outer_class_info_index(new_index);
+-    }
+-    cur_index = iter.inner_name_index();
+-    new_index = find_new_index(cur_index);
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("inner_name change: %d to %d", cur_index, new_index));
+-      iter.set_inner_name_index(new_index);
+-    }
+-  } // end for each inner class
+-
+-  // Attach each method in klass to the new constant pool and update
+-  // to use new constant pool indices as needed:
+-  objArrayHandle methods(THREAD, scratch_class->methods());
+-  for (i = methods->length() - 1; i >= 0; i--) {
+-    methodHandle method(THREAD, (methodOop)methods->obj_at(i));
+-    method->set_constants(scratch_cp());
+-
+-    int new_index = find_new_index(method->name_index());
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("method-name_index change: %d to %d", method->name_index(),
+-        new_index));
+-      method->set_name_index(new_index);
+-    }
+-    new_index = find_new_index(method->signature_index());
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("method-signature_index change: %d to %d",
+-        method->signature_index(), new_index));
+-      method->set_signature_index(new_index);
+-    }
+-    new_index = find_new_index(method->generic_signature_index());
+-    if (new_index != 0) {
+-      RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-        ("method-generic_signature_index change: %d to %d",
+-        method->generic_signature_index(), new_index));
+-      method->set_generic_signature_index(new_index);
+-    }
+-
+-    // Update constant pool indices in the method's checked exception
+-    // table to use new constant indices as needed.
+-    int cext_length = method->checked_exceptions_length();
+-    if (cext_length > 0) {
+-      CheckedExceptionElement * cext_table =
+-        method->checked_exceptions_start();
+-      for (int j = 0; j < cext_length; j++) {
+-        int cur_index = cext_table[j].class_cp_index;
+-        int new_index = find_new_index(cur_index);
+-        if (new_index != 0) {
+-          RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-            ("cext-class_cp_index change: %d to %d", cur_index, new_index));
+-          cext_table[j].class_cp_index = (u2)new_index;
+-        }
+-      } // end for each checked exception table entry
+-    } // end if there are checked exception table entries
+-
+-    // Update each catch type index in the method's exception table
+-    // to use new constant pool indices as needed. The exception table
+-    // holds quadruple entries of the form:
+-    //   (beg_bci, end_bci, handler_bci, klass_index)
+-
+-    ExceptionTable ex_table(method());
+-    int ext_length = ex_table.length();
+-
+-    for (int j = 0; j < ext_length; j ++) {
+-      int cur_index = ex_table.catch_type_index(j);
+-      int new_index = find_new_index(cur_index);
+-      if (new_index != 0) {
+-        RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-          ("ext-klass_index change: %d to %d", cur_index, new_index));
+-        ex_table.set_catch_type_index(j, new_index);
+-      }
+-    } // end for each exception table entry
+-
+-    // Update constant pool indices in the method's local variable
+-    // table to use new constant indices as needed. The local variable
+-    // table hold sextuple entries of the form:
+-    // (start_pc, length, name_index, descriptor_index, signature_index, slot)
+-    int lvt_length = method->localvariable_table_length();
+-    if (lvt_length > 0) {
+-      LocalVariableTableElement * lv_table =
+-        method->localvariable_table_start();
+-      for (int j = 0; j < lvt_length; j++) {
+-        int cur_index = lv_table[j].name_cp_index;
+-        int new_index = find_new_index(cur_index);
+-        if (new_index != 0) {
+-          RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-            ("lvt-name_cp_index change: %d to %d", cur_index, new_index));
+-          lv_table[j].name_cp_index = (u2)new_index;
+-        }
+-        cur_index = lv_table[j].descriptor_cp_index;
+-        new_index = find_new_index(cur_index);
+-        if (new_index != 0) {
+-          RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-            ("lvt-descriptor_cp_index change: %d to %d", cur_index,
+-            new_index));
+-          lv_table[j].descriptor_cp_index = (u2)new_index;
+-        }
+-        cur_index = lv_table[j].signature_cp_index;
+-        new_index = find_new_index(cur_index);
+-        if (new_index != 0) {
+-          RC_TRACE_WITH_THREAD(0x00080000, THREAD,
+-            ("lvt-signature_cp_index change: %d to %d", cur_index, new_index));
+-          lv_table[j].signature_cp_index = (u2)new_index;
+-        }
+-      } // end for each local variable table entry
+-    } // end if there are local variable table entries
++        methodHandle method = instanceTransformerMethods.at(klass->redefinition_index());
+ 
+-    rewrite_cp_refs_in_stack_map_table(method, THREAD);
+-  } // end for each method
+-  assert(scratch_cp()->is_conc_safe(), "Just checking");
+-} // end set_new_constant_pool()
++        RC_TRACE(0x00008000, ("executing transformer method"));
++        
++        Thread *__the_thread__ = Thread::current();
++        JavaValue result(T_VOID);
++        JavaCallArguments args(cur);
++        JavaCalls::call(&result,
++          method,
++          &args,
++          THREAD);
+ 
++        // TODO: What to do with an exception here?
++        if (HAS_PENDING_EXCEPTION) {
++          Symbol* ex_name = PENDING_EXCEPTION->klass()->klass_part()->name();
++          RC_TRACE(0x00000002, ("exception when executing transformer: '%s'",
++            ex_name->as_C_string()));
++          CLEAR_PENDING_EXCEPTION;
++        }
++      }
++    }
+ 
+-// Unevolving classes may point to methods of the_class directly
+-// from their constant pool caches, itables, and/or vtables. We
+-// use the SystemDictionary::classes_do() facility and this helper
+-// to fix up these pointers.
+-//
+-// Note: We currently don't support updating the vtable in
+-// arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp.
+-void VM_RedefineClasses::adjust_cpool_cache_and_vtable(klassOop k_oop,
+-       oop initiating_loader, TRAPS) {
+-  Klass *k = k_oop->klass_part();
+-  if (k->oop_is_instance()) {
+-    HandleMark hm(THREAD);
+-    instanceKlass *ik = (instanceKlass *) k;
++    delete _updated_oops;
++    _updated_oops = NULL;
++  }
+ 
+-    // HotSpot specific optimization! HotSpot does not currently
+-    // support delegation from the bootstrap class loader to a
+-    // user-defined class loader. This means that if the bootstrap
+-    // class loader is the initiating class loader, then it will also
+-    // be the defining class loader. This also means that classes
+-    // loaded by the bootstrap class loader cannot refer to classes
+-    // loaded by a user-defined class loader. Note: a user-defined
+-    // class loader can delegate to the bootstrap class loader.
+-    //
+-    // If the current class being redefined has a user-defined class
+-    // loader as its defining class loader, then we can skip all
+-    // classes loaded by the bootstrap class loader.
+-    bool is_user_defined =
+-           instanceKlass::cast(_the_class_oop)->class_loader() != NULL;
+-    if (is_user_defined && ik->class_loader() == NULL) {
+-      return;
+-    }
++  // Free the array of scratch classes
++  delete _new_classes;
++  _new_classes = NULL;
++  RC_TRACE(0x00000001, ("Redefinition finished!"));
+ 
+-    // This is a very busy routine. We don't want too much tracing
+-    // printed out.
+-    bool trace_name_printed = false;
+-
+-    // Very noisy: only enable this call if you are trying to determine
+-    // that a specific class gets found by this routine.
+-    // RC_TRACE macro has an embedded ResourceMark
+-    // RC_TRACE_WITH_THREAD(0x00100000, THREAD,
+-    //   ("adjust check: name=%s", ik->external_name()));
+-    // trace_name_printed = true;
+-
+-    // Fix the vtable embedded in the_class and subclasses of the_class,
+-    // if one exists. We discard scratch_class and we don't keep an
+-    // instanceKlass around to hold obsolete methods so we don't have
+-    // any other instanceKlass embedded vtables to update. The vtable
+-    // holds the methodOops for virtual (but not final) methods.
+-    if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) {
+-      // ik->vtable() creates a wrapper object; rm cleans it up
+-      ResourceMark rm(THREAD);
+-      ik->vtable()->adjust_method_entries(_matching_old_methods,
+-                                          _matching_new_methods,
+-                                          _matching_methods_length,
+-                                          &trace_name_printed);
+-    }
+-
+-    // If the current class has an itable and we are either redefining an
+-    // interface or if the current class is a subclass of the_class, then
+-    // we potentially have to fix the itable. If we are redefining an
+-    // interface, then we have to call adjust_method_entries() for
+-    // every instanceKlass that has an itable since there isn't a
+-    // subclass relationship between an interface and an instanceKlass.
+-    if (ik->itable_length() > 0 && (Klass::cast(_the_class_oop)->is_interface()
+-        || ik->is_subclass_of(_the_class_oop))) {
+-      // ik->itable() creates a wrapper object; rm cleans it up
+-      ResourceMark rm(THREAD);
+-      ik->itable()->adjust_method_entries(_matching_old_methods,
+-                                          _matching_new_methods,
+-                                          _matching_methods_length,
+-                                          &trace_name_printed);
+-    }
+-
+-    // The constant pools in other classes (other_cp) can refer to
+-    // methods in the_class. We have to update method information in
+-    // other_cp's cache. If other_cp has a previous version, then we
+-    // have to repeat the process for each previous version. The
+-    // constant pool cache holds the methodOops for non-virtual
+-    // methods and for virtual, final methods.
+-    //
+-    // Special case: if the current class is the_class, then new_cp
+-    // has already been attached to the_class and old_cp has already
+-    // been added as a previous version. The new_cp doesn't have any
+-    // cached references to old methods so it doesn't need to be
+-    // updated. We can simply start with the previous version(s) in
+-    // that case.
+-    constantPoolHandle other_cp;
+-    constantPoolCacheOop cp_cache;
+-
+-    if (k_oop != _the_class_oop) {
+-      // this klass' constant pool cache may need adjustment
+-      other_cp = constantPoolHandle(ik->constants());
+-      cp_cache = other_cp->cache();
+-      if (cp_cache != NULL) {
+-        cp_cache->adjust_method_entries(_matching_old_methods,
+-                                        _matching_new_methods,
+-                                        _matching_methods_length,
+-                                        &trace_name_printed);
+-      }
+-    }
+-    {
+-      ResourceMark rm(THREAD);
+-      // PreviousVersionInfo objects returned via PreviousVersionWalker
+-      // contain a GrowableArray of handles. We have to clean up the
+-      // GrowableArray _after_ the PreviousVersionWalker destructor
+-      // has destroyed the handles.
+-      {
+-        // the previous versions' constant pool caches may need adjustment
+-        PreviousVersionWalker pvw(ik);
+-        for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
+-             pv_info != NULL; pv_info = pvw.next_previous_version()) {
+-          other_cp = pv_info->prev_constant_pool_handle();
+-          cp_cache = other_cp->cache();
+-          if (cp_cache != NULL) {
+-            cp_cache->adjust_method_entries(_matching_old_methods,
+-                                            _matching_new_methods,
+-                                            _matching_methods_length,
+-                                            &trace_name_printed);
+-          }
+-        }
+-      } // pvw is cleaned up
+-    } // rm is cleaned up
++  RC_TIMER_STOP(_timer_vm_op_epilogue);
++}
++
++bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) {
++  // classes for primitives cannot be redefined
++  if (java_lang_Class::is_primitive(klass_mirror)) {
++    return false;
++  }
++  klassOop the_class_oop = java_lang_Class::as_klassOop(klass_mirror);
++  // classes for arrays cannot be redefined
++  if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) {
++    return false;
+   }
++  return true;
+ }
+ 
+-void VM_RedefineClasses::update_jmethod_ids() {
+-  for (int j = 0; j < _matching_methods_length; ++j) {
+-    methodOop old_method = _matching_old_methods[j];
+-    jmethodID jmid = old_method->find_jmethod_id_or_null();
+-    if (jmid != NULL) {
+-      // There is a jmethodID, change it to point to the new method
+-      methodHandle new_method_h(_matching_new_methods[j]);
+-      JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h);
+-      assert(JNIHandles::resolve_jmethod_id(jmid) == _matching_new_methods[j],
+-             "should be replaced");
+-    }
++#ifdef ASSERT
++
++void VM_RedefineClasses::verify_classes(klassOop k_oop_latest, oop initiating_loader, TRAPS) {
++  klassOop k_oop = k_oop_latest;
++  while (k_oop != NULL) {
++
++    instanceKlassHandle k_handle(THREAD, k_oop);
++    Verifier::verify(k_handle, Verifier::ThrowException, true, true, THREAD);
++    k_oop = k_oop->klass_part()->old_version();
+   }
+ }
+ 
+-void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
+-       BitMap *emcp_methods, int * emcp_method_count_p) {
+-  *emcp_method_count_p = 0;
+-  int obsolete_count = 0;
+-  int old_index = 0;
+-  for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
+-    methodOop old_method = _matching_old_methods[j];
+-    methodOop new_method = _matching_new_methods[j];
+-    methodOop old_array_method;
+-
+-    // Maintain an old_index into the _old_methods array by skipping
+-    // deleted methods
+-    while ((old_array_method = (methodOop) _old_methods->obj_at(old_index))
+-                                                            != old_method) {
+-      ++old_index;
+-    }
+-
+-    if (MethodComparator::methods_EMCP(old_method, new_method)) {
+-      // The EMCP definition from JSR-163 requires the bytecodes to be
+-      // the same with the exception of constant pool indices which may
+-      // differ. However, the constants referred to by those indices
+-      // must be the same.
+-      //
+-      // We use methods_EMCP() for comparison since constant pool
+-      // merging can remove duplicate constant pool entries that were
+-      // present in the old method and removed from the rewritten new
+-      // method. A faster binary comparison function would consider the
+-      // old and new methods to be different when they are actually
+-      // EMCP.
+-      //
+-      // The old and new methods are EMCP and you would think that we
+-      // could get rid of one of them here and now and save some space.
+-      // However, the concept of EMCP only considers the bytecodes and
+-      // the constant pool entries in the comparison. Other things,
+-      // e.g., the line number table (LNT) or the local variable table
+-      // (LVT) don't count in the comparison. So the new (and EMCP)
+-      // method can have a new LNT that we need so we can't just
+-      // overwrite the new method with the old method.
+-      //
+-      // When this routine is called, we have already attached the new
+-      // methods to the_class so the old methods are effectively
+-      // overwritten. However, if an old method is still executing,
+-      // then the old method cannot be collected until sometime after
+-      // the old method call has returned. So the overwriting of old
+-      // methods by new methods will save us space except for those
+-      // (hopefully few) old methods that are still executing.
+-      //
+-      // A method refers to a constMethodOop and this presents another
+-      // possible avenue to space savings. The constMethodOop in the
+-      // new method contains possibly new attributes (LNT, LVT, etc).
+-      // At first glance, it seems possible to save space by replacing
+-      // the constMethodOop in the old method with the constMethodOop
+-      // from the new method. The old and new methods would share the
+-      // same constMethodOop and we would save the space occupied by
+-      // the old constMethodOop. However, the constMethodOop contains
+-      // a back reference to the containing method. Sharing the
+-      // constMethodOop between two methods could lead to confusion in
+-      // the code that uses the back reference. This would lead to
+-      // brittle code that could be broken in non-obvious ways now or
+-      // in the future.
+-      //
+-      // Another possibility is to copy the constMethodOop from the new
+-      // method to the old method and then overwrite the new method with
+-      // the old method. Since the constMethodOop contains the bytecodes
+-      // for the method embedded in the oop, this option would change
+-      // the bytecodes out from under any threads executing the old
+-      // method and make the thread's bcp invalid. Since EMCP requires
+-      // that the bytecodes be the same modulo constant pool indices, it
+-      // is straight forward to compute the correct new bcp in the new
+-      // constMethodOop from the old bcp in the old constMethodOop. The
+-      // time consuming part would be searching all the frames in all
+-      // of the threads to find all of the calls to the old method.
+-      //
+-      // It looks like we will have to live with the limited savings
+-      // that we get from effectively overwriting the old methods
+-      // when the new methods are attached to the_class.
+-
+-      // track which methods are EMCP for add_previous_version() call
+-      emcp_methods->set_bit(old_index);
+-      (*emcp_method_count_p)++;
+-
+-      // An EMCP method is _not_ obsolete. An obsolete method has a
+-      // different jmethodID than the current method. An EMCP method
+-      // has the same jmethodID as the current method. Having the
+-      // same jmethodID for all EMCP versions of a method allows for
+-      // a consistent view of the EMCP methods regardless of which
+-      // EMCP method you happen to have in hand. For example, a
+-      // breakpoint set in one EMCP method will work for all EMCP
+-      // versions of the method including the current one.
+-    } else {
+-      // mark obsolete methods as such
+-      old_method->set_is_obsolete();
+-      obsolete_count++;
++#endif
+ 
+-      // obsolete methods need a unique idnum
+-      u2 num = instanceKlass::cast(_the_class_oop)->next_method_idnum();
+-      if (num != constMethodOopDesc::UNSET_IDNUM) {
+-//      u2 old_num = old_method->method_idnum();
+-        old_method->set_method_idnum(num);
+-// TO DO: attach obsolete annotations to obsolete method's new idnum
++// Rewrite faster byte-codes back to their slower equivalent. Undoes rewriting happening in templateTable_xxx.cpp
++// The reason is that once we zero cpool caches, we need to re-resolve all entries again. Faster bytecodes do not
++// do that, they assume that cache entry is resolved already.
++static void unpatch_bytecode(methodOop method) {
++  RawBytecodeStream bcs(method);
++  Bytecodes::Code code;
++  Bytecodes::Code java_code;
++  while (!bcs.is_last_bytecode()) {
++    code = bcs.raw_next();
++    address bcp = bcs.bcp();
++
++    if (code == Bytecodes::_breakpoint) {
++      int bci = method->bci_from(bcp);
++      code = method->orig_bytecode_at(bci);
++      java_code = Bytecodes::java_code(code);
++      if (code != java_code &&
++           (java_code == Bytecodes::_getfield ||
++            java_code == Bytecodes::_putfield ||
++            java_code == Bytecodes::_aload_0)) {
++        // Let breakpoint table handling unpatch bytecode
++        method->set_orig_bytecode_at(bci, java_code);
+       }
+-      // With tracing we try not to "yack" too much. The position of
+-      // this trace assumes there are fewer obsolete methods than
+-      // EMCP methods.
+-      RC_TRACE(0x00000100, ("mark %s(%s) as obsolete",
+-        old_method->name()->as_C_string(),
+-        old_method->signature()->as_C_string()));
++    } else {
++      java_code = Bytecodes::java_code(code);
++      if (code != java_code &&
++           (java_code == Bytecodes::_getfield ||
++            java_code == Bytecodes::_putfield ||
++            java_code == Bytecodes::_aload_0)) {
++        *bcp = java_code;
++      }
++    }
++
++    // Additionally, we need to unpatch bytecode at bcp+1 for fast_xaccess (which would be fast field access)
++    if (code == Bytecodes::_fast_iaccess_0 || code == Bytecodes::_fast_aaccess_0 || code == Bytecodes::_fast_faccess_0) {
++      Bytecodes::Code code2 = Bytecodes::code_or_bp_at(bcp + 1);
++      assert(code2 == Bytecodes::_fast_igetfield ||
++             code2 == Bytecodes::_fast_agetfield ||
++             code2 == Bytecodes::_fast_fgetfield, "");
++      *(bcp + 1) = Bytecodes::java_code(code2);
+     }
+-    old_method->set_is_old();
+-  }
+-  for (int i = 0; i < _deleted_methods_length; ++i) {
+-    methodOop old_method = _deleted_methods[i];
+-
+-    assert(old_method->vtable_index() < 0,
+-           "cannot delete methods with vtable entries");;
+-
+-    // Mark all deleted methods as old and obsolete
+-    old_method->set_is_old();
+-    old_method->set_is_obsolete();
+-    ++obsolete_count;
+-    // With tracing we try not to "yack" too much. The position of
+-    // this trace assumes there are fewer obsolete methods than
+-    // EMCP methods.
+-    RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete",
+-                          old_method->name()->as_C_string(),
+-                          old_method->signature()->as_C_string()));
+-  }
+-  assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
+-    "sanity check");
+-  RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
+-    obsolete_count));
++  }
+ }
+ 
+-// This internal class transfers the native function registration from old methods
+-// to new methods.  It is designed to handle both the simple case of unchanged
+-// native methods and the complex cases of native method prefixes being added and/or
+-// removed.
+-// It expects only to be used during the VM_RedefineClasses op (a safepoint).
+-//
+-// This class is used after the new methods have been installed in "the_class".
+-//
+-// So, for example, the following must be handled.  Where 'm' is a method and
+-// a number followed by an underscore is a prefix.
+-//
+-//                                      Old Name    New Name
+-// Simple transfer to new method        m       ->  m
+-// Add prefix                           m       ->  1_m
+-// Remove prefix                        1_m     ->  m
+-// Simultaneous add of prefixes         m       ->  3_2_1_m
+-// Simultaneous removal of prefixes     3_2_1_m ->  m
+-// Simultaneous add and remove          1_m     ->  2_m
+-// Same, caused by prefix removal only  3_2_1_m ->  3_2_m
++// Unevolving classes may point to old methods directly
++// from their constant pool caches, itables, and/or vtables. We
++// use the SystemDictionary::classes_do() facility and this helper
++// to fix up these pointers. Additional field offsets and vtable indices
++// in the constant pool cache entries are fixed.
+ //
+-class TransferNativeFunctionRegistration {
+- private:
+-  instanceKlassHandle the_class;
+-  int prefix_count;
+-  char** prefixes;
++// Note: We currently don't support updating the vtable in
++// arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp.
++void VM_RedefineClasses::adjust_cpool_cache(klassOop k_oop_latest, oop initiating_loader, TRAPS) {
++  klassOop k_oop = k_oop_latest;
++  while (k_oop != NULL) {
++    //tty->print_cr("name=%s", k_oop->klass_part()->name()->as_C_string());
++/*
++    methodOop *matching_old_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
++    methodOop *matching_new_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
+ 
+-  // Recursively search the binary tree of possibly prefixed method names.
+-  // Iteration could be used if all agents were well behaved. Full tree walk is
+-  // more resilent to agents not cleaning up intermediate methods.
+-  // Branch at each depth in the binary tree is:
+-  //    (1) without the prefix.
+-  //    (2) with the prefix.
+-  // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
+-  methodOop search_prefix_name_space(int depth, char* name_str, size_t name_len,
+-                                     Symbol* signature) {
+-    TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len);
+-    if (name_symbol != NULL) {
+-      methodOop method = Klass::cast(the_class())->lookup_method(name_symbol, signature);
+-      if (method != NULL) {
+-        // Even if prefixed, intermediate methods must exist.
+-        if (method->is_native()) {
+-          // Wahoo, we found a (possibly prefixed) version of the method, return it.
+-          return method;
+-        }
+-        if (depth < prefix_count) {
+-          // Try applying further prefixes (other than this one).
+-          method = search_prefix_name_space(depth+1, name_str, name_len, signature);
+-          if (method != NULL) {
+-            return method; // found
+-          }
++    for (int i=0; i<_matching_methods_length; i++) {
++      matching_old_methods[i] = (methodOop)_old_methods->obj_at(_matching_old_methods[i]);
++      matching_new_methods[i] = (methodOop)_new_methods->obj_at(_matching_new_methods[i]);
++    }*/
+ 
+-          // Try adding this prefix to the method name and see if it matches
+-          // another method name.
+-          char* prefix = prefixes[depth];
+-          size_t prefix_len = strlen(prefix);
+-          size_t trial_len = name_len + prefix_len;
+-          char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
+-          strcpy(trial_name_str, prefix);
+-          strcat(trial_name_str, name_str);
+-          method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
+-                                            signature);
+-          if (method != NULL) {
+-            // If found along this branch, it was prefixed, mark as such
+-            method->set_is_prefixed_native();
+-            return method; // found
+-          }
+-        }
+-      }
+-    }
+-    return NULL;  // This whole branch bore nothing
+-  }
++    Klass *k = k_oop->klass_part();
++    if (k->oop_is_instance()) {
++      HandleMark hm(THREAD);
++      instanceKlass *ik = (instanceKlass *) k;
+ 
+-  // Return the method name with old prefixes stripped away.
+-  char* method_name_without_prefixes(methodOop method) {
+-    Symbol* name = method->name();
+-    char* name_str = name->as_utf8();
++      constantPoolHandle other_cp;
++      constantPoolCacheOop cp_cache;
+ 
+-    // Old prefixing may be defunct, strip prefixes, if any.
+-    for (int i = prefix_count-1; i >= 0; i--) {
+-      char* prefix = prefixes[i];
+-      size_t prefix_len = strlen(prefix);
+-      if (strncmp(prefix, name_str, prefix_len) == 0) {
+-        name_str += prefix_len;
+-      }
+-    }
+-    return name_str;
+-  }
++      other_cp = constantPoolHandle(ik->constants());
+ 
+-  // Strip any prefixes off the old native method, then try to find a
+-  // (possibly prefixed) new native that matches it.
+-  methodOop strip_and_search_for_new_native(methodOop method) {
+-    ResourceMark rm;
+-    char* name_str = method_name_without_prefixes(method);
+-    return search_prefix_name_space(0, name_str, strlen(name_str),
+-                                    method->signature());
+-  }
++      for (int i=0; i<other_cp->length(); i++) {
++        if (other_cp->tag_at(i).is_klass()) {
++          klassOop klass = other_cp->klass_at(i, THREAD);
++          if (klass->klass_part()->new_version() != NULL) {
+ 
+- public:
++            // (tw) TODO: check why/if this is necessary
++            other_cp->klass_at_put(i, klass->klass_part()->new_version());
++          }
++          klass = other_cp->klass_at(i, THREAD);
++          assert(klass->klass_part()->new_version() == NULL, "Must be new klass!");
++        }
++      }
+ 
+-  // Construct a native method transfer processor for this class.
+-  TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
+-    assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
++      cp_cache = other_cp->cache();
+ 
+-    the_class = _the_class;
+-    prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
++      if (cp_cache != NULL) {
++        cp_cache->adjust_entries(NULL,
++          NULL,
++          0);
++      }
++
++      // If bytecode rewriting is enabled, we also need to unpatch bytecode to force resolution of zeroied entries
++      if (RewriteBytecodes) {
++        ik->methods_do(unpatch_bytecode);
++      }
++    }
++    k_oop = k_oop->klass_part()->old_version();
+   }
++}
+ 
+-  // Attempt to transfer any of the old or deleted methods that are native
+-  void transfer_registrations(methodOop* old_methods, int methods_length) {
+-    for (int j = 0; j < methods_length; j++) {
+-      methodOop old_method = old_methods[j];
++void VM_RedefineClasses::update_jmethod_ids() {
++  for (int j = 0; j < _matching_methods_length; ++j) {
++    methodOop old_method = (methodOop)_old_methods->obj_at(_matching_old_methods[j]);
++    RC_TRACE(0x00008000, ("matching method %s", old_method->name_and_sig_as_C_string()));
++    
++    jmethodID jmid = old_method->find_jmethod_id_or_null();
++    if (old_method->new_version() != NULL && jmid == NULL) {
++       // (tw) Have to create jmethodID in this case
++       jmid = old_method->jmethod_id();
++    }
++
++    if (jmid != NULL) {
++      // There is a jmethodID, change it to point to the new method
++      methodHandle new_method_h((methodOop)_new_methods->obj_at(_matching_new_methods[j]));
++      if (old_method->new_version() == NULL) {
++        methodHandle old_method_h((methodOop)_old_methods->obj_at(_matching_old_methods[j]));
++        jmethodID new_jmethod_id = JNIHandles::make_jmethod_id(old_method_h);
++        bool result = instanceKlass::cast(old_method_h->method_holder())->update_jmethod_id(old_method_h(), new_jmethod_id);
++        //RC_TRACE(0x00008000, ("Changed jmethodID for old method assigned to %d / result=%d", new_jmethod_id, result);
++        //RC_TRACE(0x00008000, ("jmethodID new method: %d jmethodID old method: %d", new_method_h->jmethod_id(), old_method->jmethod_id());
++      } else {
++        jmethodID mid = new_method_h->jmethod_id();
++        bool result = instanceKlass::cast(new_method_h->method_holder())->update_jmethod_id(new_method_h(), jmid);
++        //RC_TRACE(0x00008000, ("Changed jmethodID for new method assigned to %d / result=%d", jmid, result);
+ 
+-      if (old_method->is_native() && old_method->has_native_function()) {
+-        methodOop new_method = strip_and_search_for_new_native(old_method);
+-        if (new_method != NULL) {
+-          // Actually set the native function in the new method.
+-          // Redefine does not send events (except CFLH), certainly not this
+-          // behind the scenes re-registration.
+-          new_method->set_native_function(old_method->native_function(),
+-                              !methodOopDesc::native_bind_event_is_interesting);
+-        }
+       }
++      JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h);
++      //RC_TRACE(0x00008000, ("changing method associated with jmethod id %d to %s", (int)jmid, new_method_h->name()->as_C_string());
++      assert(JNIHandles::resolve_jmethod_id(jmid) == (methodOop)_new_methods->obj_at(_matching_new_methods[j]), "should be replaced");
++      jmethodID mid = ((methodOop)_new_methods->obj_at(_matching_new_methods[j]))->jmethod_id();
++      assert(JNIHandles::resolve_non_null((jobject)mid) == new_method_h(), "must match!");
++
++      //RC_TRACE(0x00008000, ("jmethodID new method: %d jmethodID old method: %d", new_method_h->jmethod_id(), old_method->jmethod_id());
+     }
+   }
+-};
+-
+-// Don't lose the association between a native method and its JNI function.
+-void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) {
+-  TransferNativeFunctionRegistration transfer(the_class);
+-  transfer.transfer_registrations(_deleted_methods, _deleted_methods_length);
+-  transfer.transfer_registrations(_matching_old_methods, _matching_methods_length);
+ }
+ 
++
+ // Deoptimize all compiled code that depends on this class.
+ //
+ // If the can_redefine_classes capability is obtained in the onload
+@@ -3101,7 +2677,10 @@ void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
+ 
+   // All dependencies have been recorded from startup or this is a second or
+   // subsequent use of RedefineClasses
+-  if (JvmtiExport::all_dependencies_are_recorded()) {
++
++  // For now deopt all
++  // (tw) TODO: Improve the dependency system such that we can safely deopt only a subset of the methods
++  if (0 && JvmtiExport::all_dependencies_are_recorded()) {
+     Universe::flush_evol_dependents_on(k_h);
+   } else {
+     CodeCache::mark_all_nmethods_for_deoptimization();
+@@ -3124,10 +2703,10 @@ void VM_RedefineClasses::compute_added_deleted_matching_methods() {
+   methodOop old_method;
+   methodOop new_method;
+ 
+-  _matching_old_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
+-  _matching_new_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
+-  _added_methods        = NEW_RESOURCE_ARRAY(methodOop, _new_methods->length());
+-  _deleted_methods      = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length());
++  _matching_old_methods = NEW_RESOURCE_ARRAY(int, _old_methods->length());
++  _matching_new_methods = NEW_RESOURCE_ARRAY(int, _old_methods->length());
++  _added_methods        = NEW_RESOURCE_ARRAY(int, _new_methods->length());
++  _deleted_methods      = NEW_RESOURCE_ARRAY(int, _old_methods->length());
+ 
+   _matching_methods_length = 0;
+   _deleted_methods_length  = 0;
+@@ -3142,36 +2721,36 @@ void VM_RedefineClasses::compute_added_deleted_matching_methods() {
+       }
+       // New method at the end
+       new_method = (methodOop) _new_methods->obj_at(nj);
+-      _added_methods[_added_methods_length++] = new_method;
++      _added_methods[_added_methods_length++] = nj;
+       ++nj;
+     } else if (nj >= _new_methods->length()) {
+       // Old method, at the end, is deleted
+       old_method = (methodOop) _old_methods->obj_at(oj);
+-      _deleted_methods[_deleted_methods_length++] = old_method;
++      _deleted_methods[_deleted_methods_length++] = oj;
+       ++oj;
+     } else {
+       old_method = (methodOop) _old_methods->obj_at(oj);
+       new_method = (methodOop) _new_methods->obj_at(nj);
+       if (old_method->name() == new_method->name()) {
+         if (old_method->signature() == new_method->signature()) {
+-          _matching_old_methods[_matching_methods_length  ] = old_method;
+-          _matching_new_methods[_matching_methods_length++] = new_method;
++          _matching_old_methods[_matching_methods_length  ] = oj;//old_method;
++          _matching_new_methods[_matching_methods_length++] = nj;//new_method;
+           ++nj;
+           ++oj;
+         } else {
+           // added overloaded have already been moved to the end,
+           // so this is a deleted overloaded method
+-          _deleted_methods[_deleted_methods_length++] = old_method;
++          _deleted_methods[_deleted_methods_length++] = oj;//old_method;
+           ++oj;
+         }
+       } else { // names don't match
+         if (old_method->name()->fast_compare(new_method->name()) > 0) {
+           // new method
+-          _added_methods[_added_methods_length++] = new_method;
++          _added_methods[_added_methods_length++] = nj;//new_method;
+           ++nj;
+         } else {
+           // deleted method
+-          _deleted_methods[_deleted_methods_length++] = old_method;
++          _deleted_methods[_deleted_methods_length++] = oj;//old_method;
+           ++oj;
+         }
+       }
+@@ -3179,6 +2758,8 @@ void VM_RedefineClasses::compute_added_deleted_matching_methods() {
+   }
+   assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
+   assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
++  RC_TRACE(0x00008000, ("Matching methods = %d / deleted methods = %d / added methods = %d",
++    _matching_methods_length, _deleted_methods_length, _added_methods_length));
+ }
+ 
+ 
+@@ -3186,297 +2767,184 @@ void VM_RedefineClasses::compute_added_deleted_matching_methods() {
+ // Install the redefinition of a class:
+ //    - house keeping (flushing breakpoints and caches, deoptimizing
+ //      dependent compiled code)
+-//    - replacing parts in the_class with parts from scratch_class
+-//    - adding a weak reference to track the obsolete but interesting
+-//      parts of the_class
+ //    - adjusting constant pool caches and vtables in other classes
+-//      that refer to methods in the_class. These adjustments use the
+-//      SystemDictionary::classes_do() facility which only allows
+-//      a helper method to be specified. The interesting parameters
+-//      that we would like to pass to the helper method are saved in
+-//      static global fields in the VM operation.
+-void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
+-       instanceKlassHandle scratch_class, TRAPS) {
++void VM_RedefineClasses::redefine_single_class(instanceKlassHandle the_new_class, TRAPS) {
++
++  ResourceMark rm(THREAD);
+ 
+-  RC_TIMER_START(_timer_rsc_phase1);
++  assert(the_new_class->old_version() != NULL, "Must not be null");
++  assert(the_new_class->old_version()->klass_part()->new_version() == the_new_class(), "Must equal");
+ 
+-  oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass);
+-  klassOop the_class_oop = java_lang_Class::as_klassOop(the_class_mirror);
+-  instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
++  instanceKlassHandle the_old_class = instanceKlassHandle(THREAD, the_new_class->old_version());
+ 
++#ifndef JVMTI_KERNEL
+   // Remove all breakpoints in methods of this class
+   JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
+-  jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop);
++  jvmti_breakpoints.clearall_in_class_at_safepoint(the_old_class());
++#endif // !JVMTI_KERNEL
+ 
+-  if (the_class_oop == Universe::reflect_invoke_cache()->klass()) {
++  if (the_old_class() == Universe::reflect_invoke_cache()->klass()) {
+     // We are redefining java.lang.reflect.Method. Method.invoke() is
+     // cached and users of the cache care about each active version of
+     // the method so we have to track this previous version.
+     // Do this before methods get switched
+     Universe::reflect_invoke_cache()->add_previous_version(
+-      the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
++      the_old_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
+   }
+ 
+-  // Deoptimize all compiled code that depends on this class
+-  flush_dependent_code(the_class, THREAD);
+-
+-  _old_methods = the_class->methods();
+-  _new_methods = scratch_class->methods();
+-  _the_class_oop = the_class_oop;
++  _old_methods = the_old_class->methods();
++  _new_methods = the_new_class->methods();
++  _the_class_oop = the_old_class();
+   compute_added_deleted_matching_methods();
+-  update_jmethod_ids();
+-
+-  // Attach new constant pool to the original klass. The original
+-  // klass still refers to the old constant pool (for now).
+-  scratch_class->constants()->set_pool_holder(the_class());
+-
+-#if 0
+-  // In theory, with constant pool merging in place we should be able
+-  // to save space by using the new, merged constant pool in place of
+-  // the old constant pool(s). By "pool(s)" I mean the constant pool in
+-  // the klass version we are replacing now and any constant pool(s) in
+-  // previous versions of klass. Nice theory, doesn't work in practice.
+-  // When this code is enabled, even simple programs throw NullPointer
+-  // exceptions. I'm guessing that this is caused by some constant pool
+-  // cache difference between the new, merged constant pool and the
+-  // constant pool that was just being used by the klass. I'm keeping
+-  // this code around to archive the idea, but the code has to remain
+-  // disabled for now.
+-
+-  // Attach each old method to the new constant pool. This can be
+-  // done here since we are past the bytecode verification and
+-  // constant pool optimization phases.
+-  for (int i = _old_methods->length() - 1; i >= 0; i--) {
+-    methodOop method = (methodOop)_old_methods->obj_at(i);
+-    method->set_constants(scratch_class->constants());
+-  }
+-
+-  {
+-    // walk all previous versions of the klass
+-    instanceKlass *ik = (instanceKlass *)the_class()->klass_part();
+-    PreviousVersionWalker pvw(ik);
+-    instanceKlassHandle ikh;
+-    do {
+-      ikh = pvw.next_previous_version();
+-      if (!ikh.is_null()) {
+-        ik = ikh();
+-
+-        // attach previous version of klass to the new constant pool
+-        ik->set_constants(scratch_class->constants());
+-
+-        // Attach each method in the previous version of klass to the
+-        // new constant pool
+-        objArrayOop prev_methods = ik->methods();
+-        for (int i = prev_methods->length() - 1; i >= 0; i--) {
+-          methodOop method = (methodOop)prev_methods->obj_at(i);
+-          method->set_constants(scratch_class->constants());
+-        }
+-      }
+-    } while (!ikh.is_null());
+-  }
+-#endif
+-
+-  // Replace methods and constantpool
+-  the_class->set_methods(_new_methods);
+-  scratch_class->set_methods(_old_methods);     // To prevent potential GCing of the old methods,
+-                                          // and to be able to undo operation easily.
+-
+-  constantPoolOop old_constants = the_class->constants();
+-  the_class->set_constants(scratch_class->constants());
+-  scratch_class->set_constants(old_constants);  // See the previous comment.
+-#if 0
+-  // We are swapping the guts of "the new class" with the guts of "the
+-  // class". Since the old constant pool has just been attached to "the
+-  // new class", it seems logical to set the pool holder in the old
+-  // constant pool also. However, doing this will change the observable
+-  // class hierarchy for any old methods that are still executing. A
+-  // method can query the identity of its "holder" and this query uses
+-  // the method's constant pool link to find the holder. The change in
+-  // holding class from "the class" to "the new class" can confuse
+-  // things.
+-  //
+-  // Setting the old constant pool's holder will also cause
+-  // verification done during vtable initialization below to fail.
+-  // During vtable initialization, the vtable's class is verified to be
+-  // a subtype of the method's holder. The vtable's class is "the
+-  // class" and the method's holder is gotten from the constant pool
+-  // link in the method itself. For "the class"'s directly implemented
+-  // methods, the method holder is "the class" itself (as gotten from
+-  // the new constant pool). The check works fine in this case. The
+-  // check also works fine for methods inherited from super classes.
+-  //
+-  // Miranda methods are a little more complicated. A miranda method is
+-  // provided by an interface when the class implementing the interface
+-  // does not provide its own method.  These interfaces are implemented
+-  // internally as an instanceKlass. These special instanceKlasses
+-  // share the constant pool of the class that "implements" the
+-  // interface. By sharing the constant pool, the method holder of a
+-  // miranda method is the class that "implements" the interface. In a
+-  // non-redefine situation, the subtype check works fine. However, if
+-  // the old constant pool's pool holder is modified, then the check
+-  // fails because there is no class hierarchy relationship between the
+-  // vtable's class and "the new class".
+-
+-  old_constants->set_pool_holder(scratch_class());
+-#endif
+ 
+   // track which methods are EMCP for add_previous_version() call below
+-  BitMap emcp_methods(_old_methods->length());
++  
++  // (tw) TODO: Check if we need the concept of EMCP?
++   BitMap emcp_methods(_old_methods->length());
+   int emcp_method_count = 0;
+   emcp_methods.clear();  // clears 0..(length() - 1)
++  
++  // We need to mark methods as old!!
+   check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
+-  transfer_old_native_function_registrations(the_class);
+-
+-  // The class file bytes from before any retransformable agents mucked
+-  // with them was cached on the scratch class, move to the_class.
+-  // Note: we still want to do this if nothing needed caching since it
+-  // should get cleared in the_class too.
+-  if (the_class->get_cached_class_file_bytes() == 0) {
+-    // the_class doesn't have a cache yet so copy it
+-    the_class->set_cached_class_file(
+-      scratch_class->get_cached_class_file_bytes(),
+-      scratch_class->get_cached_class_file_len());
+-  }
+-#ifndef PRODUCT
+-  else {
+-    assert(the_class->get_cached_class_file_bytes() ==
+-      scratch_class->get_cached_class_file_bytes(), "cache ptrs must match");
+-    assert(the_class->get_cached_class_file_len() ==
+-      scratch_class->get_cached_class_file_len(), "cache lens must match");
+-  }
+-#endif
+-
+-  // Replace inner_classes
+-  typeArrayOop old_inner_classes = the_class->inner_classes();
+-  the_class->set_inner_classes(scratch_class->inner_classes());
+-  scratch_class->set_inner_classes(old_inner_classes);
+-
+-  // Initialize the vtable and interface table after
+-  // methods have been rewritten
+-  {
+-    ResourceMark rm(THREAD);
+-    // no exception should happen here since we explicitly
+-    // do not check loader constraints.
+-    // compare_and_normalize_class_versions has already checked:
+-    //  - classloaders unchanged, signatures unchanged
+-    //  - all instanceKlasses for redefined classes reused & contents updated
+-    the_class->vtable()->initialize_vtable(false, THREAD);
+-    the_class->itable()->initialize_itable(false, THREAD);
+-    assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception");
+-  }
+-
+-  // Leave arrays of jmethodIDs and itable index cache unchanged
+-
+-  // Copy the "source file name" attribute from new class version
+-  the_class->set_source_file_name(scratch_class->source_file_name());
+-
+-  // Copy the "source debug extension" attribute from new class version
+-  the_class->set_source_debug_extension(
+-    scratch_class->source_debug_extension(),
+-    scratch_class->source_debug_extension() == NULL ? 0 :
+-    (int)strlen(scratch_class->source_debug_extension()));
+-
+-  // Use of javac -g could be different in the old and the new
+-  if (scratch_class->access_flags().has_localvariable_table() !=
+-      the_class->access_flags().has_localvariable_table()) {
+-
+-    AccessFlags flags = the_class->access_flags();
+-    if (scratch_class->access_flags().has_localvariable_table()) {
+-      flags.set_has_localvariable_table();
+-    } else {
+-      flags.clear_has_localvariable_table();
+-    }
+-    the_class->set_access_flags(flags);
+-  }
+-
+-  // Replace class annotation fields values
+-  typeArrayOop old_class_annotations = the_class->class_annotations();
+-  the_class->set_class_annotations(scratch_class->class_annotations());
+-  scratch_class->set_class_annotations(old_class_annotations);
+-
+-  // Replace fields annotation fields values
+-  objArrayOop old_fields_annotations = the_class->fields_annotations();
+-  the_class->set_fields_annotations(scratch_class->fields_annotations());
+-  scratch_class->set_fields_annotations(old_fields_annotations);
+-
+-  // Replace methods annotation fields values
+-  objArrayOop old_methods_annotations = the_class->methods_annotations();
+-  the_class->set_methods_annotations(scratch_class->methods_annotations());
+-  scratch_class->set_methods_annotations(old_methods_annotations);
+-
+-  // Replace methods parameter annotation fields values
+-  objArrayOop old_methods_parameter_annotations =
+-    the_class->methods_parameter_annotations();
+-  the_class->set_methods_parameter_annotations(
+-    scratch_class->methods_parameter_annotations());
+-  scratch_class->set_methods_parameter_annotations(old_methods_parameter_annotations);
+-
+-  // Replace methods default annotation fields values
+-  objArrayOop old_methods_default_annotations =
+-    the_class->methods_default_annotations();
+-  the_class->set_methods_default_annotations(
+-    scratch_class->methods_default_annotations());
+-  scratch_class->set_methods_default_annotations(old_methods_default_annotations);
+-
+-  // Replace minor version number of class file
+-  u2 old_minor_version = the_class->minor_version();
+-  the_class->set_minor_version(scratch_class->minor_version());
+-  scratch_class->set_minor_version(old_minor_version);
+-
+-  // Replace major version number of class file
+-  u2 old_major_version = the_class->major_version();
+-  the_class->set_major_version(scratch_class->major_version());
+-  scratch_class->set_major_version(old_major_version);
+-
+-  // Replace CP indexes for class and name+type of enclosing method
+-  u2 old_class_idx  = the_class->enclosing_method_class_index();
+-  u2 old_method_idx = the_class->enclosing_method_method_index();
+-  the_class->set_enclosing_method_indices(
+-    scratch_class->enclosing_method_class_index(),
+-    scratch_class->enclosing_method_method_index());
+-  scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
++  update_jmethod_ids();
+ 
+   // keep track of previous versions of this class
+-  the_class->add_previous_version(scratch_class, &emcp_methods,
++  the_new_class->add_previous_version(the_old_class, &emcp_methods,
+     emcp_method_count);
+ 
+-  RC_TIMER_STOP(_timer_rsc_phase1);
+-  RC_TIMER_START(_timer_rsc_phase2);
++  // TODO:
++  transfer_old_native_function_registrations(the_old_class);
+ 
+-  // Adjust constantpool caches and vtables for all classes
+-  // that reference methods of the evolved class.
+-  SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD);
+ 
+-  // JSR-292 support
+-  MemberNameTable* mnt = the_class->member_names();
+-  if (mnt != NULL) {
+-    bool trace_name_printed = false;
+-    mnt->adjust_method_entries(_matching_old_methods,
+-                               _matching_new_methods,
+-                               _matching_methods_length,
+-                               &trace_name_printed);
+-  }
++#ifdef ASSERT
++
++//  klassOop systemLookup1 = SystemDictionary::resolve_or_null(the_old_class->name(), the_old_class->class_loader(), the_old_class->protection_domain(), THREAD);
++//  assert(systemLookup1 == the_new_class(), "New class must be in system dictionary!");
++
++  //JNIHandles::verify();
+ 
+-  if (the_class->oop_map_cache() != NULL) {
+-    // Flush references to any obsolete methods from the oop map cache
+-    // so that obsolete methods are not pinned.
+-    the_class->oop_map_cache()->flush_obsolete_entries();
++//  klassOop systemLookup = SystemDictionary::resolve_or_null(the_old_class->name(), the_old_class->class_loader(), the_old_class->protection_domain(), THREAD);
++
++//  assert(systemLookup == the_new_class(), "New class must be in system dictionary!");
++  assert(the_new_class->old_version() != NULL, "Must not be null");
++  assert(the_new_class->old_version()->klass_part()->new_version() == the_new_class(), "Must equal");
++
++  for (int i=0; i<the_new_class->methods()->length(); i++) {
++    assert(((methodOop)the_new_class->methods()->obj_at(i))->method_holder() == the_new_class(), "method holder must match!");
+   }
+ 
++  _old_methods->verify();
++  _new_methods->verify();
++
++  the_new_class->vtable()->verify(tty);
++  the_old_class->vtable()->verify(tty);
++
++#endif
++
+   // increment the classRedefinedCount field in the_class and in any
+   // direct and indirect subclasses of the_class
+-  increment_class_counter((instanceKlass *)the_class()->klass_part(), THREAD);
++  increment_class_counter((instanceKlass *)the_old_class()->klass_part(), THREAD);
++
++}
++
++
++void VM_RedefineClasses::check_methods_and_mark_as_obsolete(BitMap *emcp_methods, int * emcp_method_count_p) {
++    RC_TRACE(0x00008000, ("Checking matching methods for EMCP"));
++    *emcp_method_count_p = 0;
++    int obsolete_count = 0;
++    int old_index = 0;
++    for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
++      methodOop old_method = (methodOop)_old_methods->obj_at(_matching_old_methods[j]);
++      methodOop new_method = (methodOop)_new_methods->obj_at(_matching_new_methods[j]);
++      methodOop old_array_method;
++
++      // Maintain an old_index into the _old_methods array by skipping
++      // deleted methods
++      while ((old_array_method = (methodOop) _old_methods->obj_at(old_index))
++        != old_method) {
++          ++old_index;
++      }
++
++      if (MethodComparator::methods_EMCP(old_method, new_method)) {
++        // The EMCP definition from JSR-163 requires the bytecodes to be
++        // the same with the exception of constant pool indices which may
++        // differ. However, the constants referred to by those indices
++        // must be the same.
++        //
++        // We use methods_EMCP() for comparison since constant pool
++        // merging can remove duplicate constant pool entries that were
++        // present in the old method and removed from the rewritten new
++        // method. A faster binary comparison function would consider the
++        // old and new methods to be different when they are actually
++        // EMCP.
++
++        // track which methods are EMCP for add_previous_version() call
++        emcp_methods->set_bit(old_index);
++        (*emcp_method_count_p)++;
++
++        // An EMCP method is _not_ obsolete. An obsolete method has a
++        // different jmethodID than the current method. An EMCP method
++        // has the same jmethodID as the current method. Having the
++        // same jmethodID for all EMCP versions of a method allows for
++        // a consistent view of the EMCP methods regardless of which
++        // EMCP method you happen to have in hand. For example, a
++        // breakpoint set in one EMCP method will work for all EMCP
++        // versions of the method including the current one.
++
++        old_method->set_new_version(new_method);
++        new_method->set_old_version(old_method);
++
++        RC_TRACE(0x00008000, ("Found EMCP method %s", old_method->name_and_sig_as_C_string()));
++
++        // Transfer breakpoints
++        instanceKlass *ik = instanceKlass::cast(old_method->method_holder());
++        for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = bp->next()) {
++          RC_TRACE(0x00000002, ("Checking breakpoint"));
++          RC_TRACE(0x00000002, ("%d / %d",
++            bp->match(old_method), bp->match(new_method)));
++          if (bp->match(old_method)) {
++            assert(bp->match(new_method), "if old method is method, then new method must match too");
++            RC_TRACE(0x00000002, ("Found a breakpoint in an old EMCP method"));
++            new_method->set_breakpoint(bp->bci());
++          }
++        }
++
++
+ 
+-  // RC_TRACE macro has an embedded ResourceMark
+-  RC_TRACE_WITH_THREAD(0x00000001, THREAD,
+-    ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)",
+-    the_class->external_name(),
+-    java_lang_Class::classRedefinedCount(the_class_mirror),
+-    os::available_memory() >> 10));
++      } else {
++        // mark obsolete methods as such
++        old_method->set_is_obsolete();
++        obsolete_count++;
++
++        // With tracing we try not to "yack" too much. The position of
++        // this trace assumes there are fewer obsolete methods than
++        // EMCP methods.
++        RC_TRACE(0x00008000, ("mark %s(%s) as obsolete",
++          old_method->name()->as_C_string(),
++          old_method->signature()->as_C_string()));
++      }
++      old_method->set_is_old();
++    }
++    for (int i = 0; i < _deleted_methods_length; ++i) {
++      methodOop old_method = (methodOop)_old_methods->obj_at(_deleted_methods[i]);
+ 
+-  RC_TIMER_STOP(_timer_rsc_phase2);
+-} // end redefine_single_class()
++      //assert(old_method->vtable_index() < 0,
++      //  "cannot delete methods with vtable entries");;
+ 
++      // Mark all deleted methods as old and obsolete
++      old_method->set_is_old();
++      old_method->set_is_obsolete();
++      ++obsolete_count;
++      // With tracing we try not to "yack" too much. The position of
++      // this trace assumes there are fewer obsolete methods than
++      // EMCP methods.
++      RC_TRACE(0x00008000, ("mark deleted %s(%s) as obsolete",
++        old_method->name()->as_C_string(),
++        old_method->signature()->as_C_string()));
++    }
++    //assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(), "sanity check");
++    RC_TRACE(0x00008000, ("EMCP_cnt=%d, obsolete_cnt=%d !", *emcp_method_count_p, obsolete_count));
++}
+ 
+ // Increment the classRedefinedCount field in the specific instanceKlass
+ // and in all direct and indirect subclasses.
+@@ -3485,134 +2953,324 @@ void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) {
+   klassOop class_oop = java_lang_Class::as_klassOop(class_mirror);
+   int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1;
+   java_lang_Class::set_classRedefinedCount(class_mirror, new_count);
++  RC_TRACE(0x00008000, ("updated count for class=%s to %d", ik->external_name(), new_count));
++}
++
++#ifndef PRODUCT
++void VM_RedefineClasses::check_class(klassOop k_oop, TRAPS) {
++  Klass *k = k_oop->klass_part();
++  if (k->oop_is_instance()) {
++    HandleMark hm(THREAD);
++    instanceKlass *ik = (instanceKlass *) k;
++    assert(ik->is_newest_version(), "must be latest version in system dictionary");
++
++    if (ik->vtable_length() > 0) {
++      ResourceMark rm(THREAD);
++      if (!ik->vtable()->check_no_old_entries()) {
++        RC_TRACE(0x00000001, ("size of class: %d\n",
++          k_oop->size()));
++        RC_TRACE(0x00000001, ("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s",
++          ik->signature_name()));
++        assert(false, "OLD method found");
++      }
+ 
+-  if (class_oop != _the_class_oop) {
+-    // _the_class_oop count is printed at end of redefine_single_class()
+-    RC_TRACE_WITH_THREAD(0x00000008, THREAD,
+-      ("updated count in subclass=%s to %d", ik->external_name(), new_count));
++      ik->vtable()->verify(tty, true);
++    }
+   }
++}
++
++#endif
++
++VM_RedefineClasses::FindAffectedKlassesClosure::FindAffectedKlassesClosure( GrowableArray<instanceKlassHandle> *original_klasses, GrowableArray<instanceKlassHandle> *result )
++{
++  assert(original_klasses != NULL && result != NULL, "");
++  this->_original_klasses = original_klasses;
++  this->_result = result;
++  SystemDictionary::classes_do(this);
++}
+ 
+-  for (Klass *subk = ik->subklass(); subk != NULL;
+-       subk = subk->next_sibling()) {
+-    if (subk->oop_is_instance()) {
+-      // Only update instanceKlasses
+-      instanceKlass *subik = (instanceKlass*)subk;
+-      // recursively do subclasses of the current subclass
+-      increment_class_counter(subik, THREAD);
++void VM_RedefineClasses::FindAffectedKlassesClosure::do_object( oop obj )
++{
++  klassOop klass = (klassOop)obj;
++  assert(!_result->contains(klass), "must not occur more than once!");
++  assert(klass->klass_part()->new_version() == NULL, "Only last version is valid entry in system dictionary");
++
++  for(int i=0; i<_original_klasses->length(); i++) {
++    instanceKlassHandle cur = _original_klasses->at(i);
++    if (cur() != klass && klass->klass_part()->is_subtype_of(cur()) && !_original_klasses->contains(klass)) {  
++      RC_TRACE(0x00008000, ("Found affected class: %s", klass->klass_part()->name()->as_C_string()));
++      _result->append(klass);
++      break;
+     }
+   }
+ }
+ 
+-void VM_RedefineClasses::check_class(klassOop k_oop,
+-       oop initiating_loader, TRAPS) {
+-  Klass *k = k_oop->klass_part();
+-  if (k->oop_is_instance()) {
+-    HandleMark hm(THREAD);
+-    instanceKlass *ik = (instanceKlass *) k;
+-    bool no_old_methods = true;  // be optimistic
+-    ResourceMark rm(THREAD);
++jvmtiError VM_RedefineClasses::do_topological_class_sorting( const jvmtiClassDefinition *class_defs, int class_count, GrowableArray<instanceKlassHandle> *affected, GrowableArray<instanceKlassHandle> *arr, TRAPS)
++{
++  GrowableArray< Pair<klassOop, klassOop> > *links = new GrowableArray< Pair<klassOop, klassOop> >();
+ 
+-    // a vtable should never contain old or obsolete methods
+-    if (ik->vtable_length() > 0 &&
+-        !ik->vtable()->check_no_old_or_obsolete_entries()) {
+-      if (RC_TRACE_ENABLED(0x00004000)) {
+-        RC_TRACE_WITH_THREAD(0x00004000, THREAD,
+-          ("klassVtable::check_no_old_or_obsolete_entries failure"
+-           " -- OLD or OBSOLETE method found -- class: %s",
+-           ik->signature_name()));
+-        ik->vtable()->dump_vtable();
+-      }
+-      no_old_methods = false;
+-    }
+-
+-    // an itable should never contain old or obsolete methods
+-    if (ik->itable_length() > 0 &&
+-        !ik->itable()->check_no_old_or_obsolete_entries()) {
+-      if (RC_TRACE_ENABLED(0x00004000)) {
+-        RC_TRACE_WITH_THREAD(0x00004000, THREAD,
+-          ("klassItable::check_no_old_or_obsolete_entries failure"
+-           " -- OLD or OBSOLETE method found -- class: %s",
+-           ik->signature_name()));
+-        ik->itable()->dump_itable();
+-      }
+-      no_old_methods = false;
+-    }
+-
+-    // the constant pool cache should never contain old or obsolete methods
+-    if (ik->constants() != NULL &&
+-        ik->constants()->cache() != NULL &&
+-        !ik->constants()->cache()->check_no_old_or_obsolete_entries()) {
+-      if (RC_TRACE_ENABLED(0x00004000)) {
+-        RC_TRACE_WITH_THREAD(0x00004000, THREAD,
+-          ("cp-cache::check_no_old_or_obsolete_entries failure"
+-           " -- OLD or OBSOLETE method found -- class: %s",
+-           ik->signature_name()));
+-        ik->constants()->cache()->dump_cache();
+-      }
+-      no_old_methods = false;
+-    }
+-
+-    if (!no_old_methods) {
+-      if (RC_TRACE_ENABLED(0x00004000)) {
+-        dump_methods();
+-      } else {
+-        tty->print_cr("INFO: use the '-XX:TraceRedefineClasses=16384' option "
+-          "to see more info about the following guarantee() failure.");
++  for (int i=0; i<class_count; i++) {
++
++    oop mirror = JNIHandles::resolve_non_null(class_defs[i].klass);
++    klassOop the_class_oop = java_lang_Class::as_klassOop(mirror);
++    instanceKlassHandle the_class(THREAD, the_class_oop);
++    Handle the_class_loader(THREAD, the_class->class_loader());
++    Handle protection_domain(THREAD, the_class->protection_domain());
++
++    ClassFileStream st((u1*) class_defs[i].class_bytes,
++      class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
++    ClassFileParser cfp(&st);
++
++    GrowableArray<Symbol*> symbolArr;
++    RC_TRACE(0x00000002, ("Before find super symbols of class %s",
++      the_class->name()->as_C_string()));
++    cfp.findSuperSymbols(the_class->name(), the_class_loader, protection_domain, the_class, symbolArr, THREAD);
++    
++    for (int j=0; j<symbolArr.length(); j++) {
++      Symbol* sym = symbolArr.at(j);
++
++      RC_TRACE(0x00008000, ("Before adding link to super class %s", sym->as_C_string()));
++
++      for (int k=0; k<arr->length(); k++) {
++        klassOop curOop = arr->at(k)();
++        // (tw) TODO: Check if we get aliasing problems with different class loaders?
++        if (curOop->klass_part()->name() == sym /*&& curOop->klass_part()->class_loader() == the_class_loader()*/) {
++          RC_TRACE(0x00000002, ("Found class to link"));
++          links->append(Pair<klassOop, klassOop>(curOop, the_class()));
++          break;
++        }
++      }
++    }
++  }
++
++
++  RC_TRACE(0x00000001, ("Identified links between classes! "));
++
++  for (int i=0; i<affected->length(); i++) {
++
++    instanceKlassHandle klass = affected->at(i);
++
++    klassOop superKlass = klass->super();
++    if (affected->contains(superKlass)) {
++      links->append(Pair<klassOop, klassOop>(superKlass, klass()));
++    }
++
++    objArrayOop superInterfaces = klass->local_interfaces();
++    for (int j=0; j<superInterfaces->length(); j++) {
++      klassOop interfaceKlass = (klassOop)superInterfaces->obj_at(j);
++      if (arr->contains(interfaceKlass)) {
++        links->append(Pair<klassOop, klassOop>(interfaceKlass, klass()));
++      }
++    }
++  }
++
++  if (RC_TRACE_ENABLED(0x00000002))  {
++    RC_TRACE(0x00000002, ("Identified links: "));
++    for (int i=0; i<links->length(); i++) {
++      RC_TRACE(0x00000002, ("%s to %s",
++        links->at(i).left()->klass_part()->name()->as_C_string(),
++        links->at(i).right()->klass_part()->name()->as_C_string()));
++    }
++  }
++
++  for (int i=0; i<arr->length(); i++) {
++
++    int j;
++    for (j=i; j<arr->length(); j++) {
++
++      int k;
++      for (k=0; k<links->length(); k++) {
++
++        klassOop k1 = links->adr_at(k)->right();
++        klassOop k2 = arr->at(j)();
++        if (k1 == k2) {
++          break;
++        }
++      }
++
++      if (k == links->length()) {
++        break;
+       }
+-      guarantee(false, "OLD and/or OBSOLETE method(s) found");
++    }
++
++    if (j == arr->length()) {
++      // circle detected
++      return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
++    }
++
++    for (int k=0; k<links->length(); k++) {
++      if (links->adr_at(k)->left() == arr->at(j)()) {
++        links->at_put(k, links->at(links->length() - 1));
++        links->remove_at(links->length() - 1);
++        k--;
++      }
++    }
++
++    instanceKlassHandle tmp = arr->at(j);
++    arr->at_put(j, arr->at(i));
++    arr->at_put(i, tmp);
++  }
++
++  return JVMTI_ERROR_NONE;
++}
++
++void VM_RedefineClasses::oops_do(OopClosure *closure) {
++
++  if (_updated_oops != NULL) {
++    for (int i=0; i<_updated_oops->length(); i++) {
++      closure->do_oop(_updated_oops->adr_at(i));
+     }
+   }
+ }
+ 
+-void VM_RedefineClasses::dump_methods() {
+-  int j;
+-  RC_TRACE(0x00004000, ("_old_methods --"));
+-  for (j = 0; j < _old_methods->length(); ++j) {
+-    methodOop m = (methodOop) _old_methods->obj_at(j);
+-    RC_TRACE_NO_CR(0x00004000, ("%4d  (%5d)  ", j, m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->print(" --  ");
+-    m->print_name(tty);
+-    tty->cr();
+-  }
+-  RC_TRACE(0x00004000, ("_new_methods --"));
+-  for (j = 0; j < _new_methods->length(); ++j) {
+-    methodOop m = (methodOop) _new_methods->obj_at(j);
+-    RC_TRACE_NO_CR(0x00004000, ("%4d  (%5d)  ", j, m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->print(" --  ");
+-    m->print_name(tty);
+-    tty->cr();
+-  }
+-  RC_TRACE(0x00004000, ("_matching_(old/new)_methods --"));
+-  for (j = 0; j < _matching_methods_length; ++j) {
+-    methodOop m = _matching_old_methods[j];
+-    RC_TRACE_NO_CR(0x00004000, ("%4d  (%5d)  ", j, m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->print(" --  ");
+-    m->print_name(tty);
+-    tty->cr();
+-    m = _matching_new_methods[j];
+-    RC_TRACE_NO_CR(0x00004000, ("      (%5d)  ", m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->cr();
+-  }
+-  RC_TRACE(0x00004000, ("_deleted_methods --"));
+-  for (j = 0; j < _deleted_methods_length; ++j) {
+-    methodOop m = _deleted_methods[j];
+-    RC_TRACE_NO_CR(0x00004000, ("%4d  (%5d)  ", j, m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->print(" --  ");
+-    m->print_name(tty);
+-    tty->cr();
+-  }
+-  RC_TRACE(0x00004000, ("_added_methods --"));
+-  for (j = 0; j < _added_methods_length; ++j) {
+-    methodOop m = _added_methods[j];
+-    RC_TRACE_NO_CR(0x00004000, ("%4d  (%5d)  ", j, m->vtable_index()));
+-    m->access_flags().print_on(tty);
+-    tty->print(" --  ");
+-    m->print_name(tty);
+-    tty->cr();
++void VM_RedefineClasses::transfer_special_access_flags(fieldDescriptor *from, fieldDescriptor *to) {
++  to->set_is_field_modification_watched(from->is_field_modification_watched());
++  to->set_is_field_access_watched(from->is_field_access_watched());
++  if (from->is_field_modification_watched() || from->is_field_access_watched()) {
++    RC_TRACE(0x00000002, ("Transferred watch for field %s",
++      from->name()->as_C_string()));
++  }
++  update_klass_field_access_flag(to);
++}
++
++void VM_RedefineClasses::update_klass_field_access_flag(fieldDescriptor *fd) {
++  instanceKlass* ik = instanceKlass::cast(fd->field_holder());
++  FieldInfo* fi = FieldInfo::from_field_array(ik->fields(), fd->index());
++  fi->set_access_flags(fd->access_flags().as_short());
++}
++
++
++// This internal class transfers the native function registration from old methods
++// to new methods.  It is designed to handle both the simple case of unchanged
++// native methods and the complex cases of native method prefixes being added and/or
++// removed.
++// It expects only to be used during the VM_RedefineClasses op (a safepoint).
++//
++// This class is used after the new methods have been installed in "the_class".
++//
++// So, for example, the following must be handled.  Where 'm' is a method and
++// a number followed by an underscore is a prefix.
++//
++//                                      Old Name    New Name
++// Simple transfer to new method        m       ->  m
++// Add prefix                           m       ->  1_m
++// Remove prefix                        1_m     ->  m
++// Simultaneous add of prefixes         m       ->  3_2_1_m
++// Simultaneous removal of prefixes     3_2_1_m ->  m
++// Simultaneous add and remove          1_m     ->  2_m
++// Same, caused by prefix removal only  3_2_1_m ->  3_2_m
++//
++class TransferNativeFunctionRegistration {
++private:
++  instanceKlassHandle the_class;
++  int prefix_count;
++  char** prefixes;
++
++  // Recursively search the binary tree of possibly prefixed method names.
++  // Iteration could be used if all agents were well behaved. Full tree walk is
++  // more resilent to agents not cleaning up intermediate methods.
++  // Branch at each depth in the binary tree is:
++  //    (1) without the prefix.
++  //    (2) with the prefix.
++  // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
++  methodOop search_prefix_name_space(int depth, char* name_str, size_t name_len,
++    Symbol* signature) {
++      Symbol* name_symbol = SymbolTable::probe(name_str, (int)name_len);
++      if (name_symbol != NULL) {
++        methodOop method = Klass::cast(the_class()->klass_part()->new_version())->lookup_method(name_symbol, signature);
++        if (method != NULL) {
++          // Even if prefixed, intermediate methods must exist.
++          if (method->is_native()) {
++            // Wahoo, we found a (possibly prefixed) version of the method, return it.
++            return method;
++          }
++          if (depth < prefix_count) {
++            // Try applying further prefixes (other than this one).
++            method = search_prefix_name_space(depth+1, name_str, name_len, signature);
++            if (method != NULL) {
++              return method; // found
++            }
++
++            // Try adding this prefix to the method name and see if it matches
++            // another method name.
++            char* prefix = prefixes[depth];
++            size_t prefix_len = strlen(prefix);
++            size_t trial_len = name_len + prefix_len;
++            char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
++            strcpy(trial_name_str, prefix);
++            strcat(trial_name_str, name_str);
++            method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
++              signature);
++            if (method != NULL) {
++              // If found along this branch, it was prefixed, mark as such
++              method->set_is_prefixed_native();
++              return method; // found
++            }
++          }
++        }
++      }
++      return NULL;  // This whole branch bore nothing
++  }
++
++  // Return the method name with old prefixes stripped away.
++  char* method_name_without_prefixes(methodOop method) {
++    Symbol* name = method->name();
++    char* name_str = name->as_utf8();
++
++    // Old prefixing may be defunct, strip prefixes, if any.
++    for (int i = prefix_count-1; i >= 0; i--) {
++      char* prefix = prefixes[i];
++      size_t prefix_len = strlen(prefix);
++      if (strncmp(prefix, name_str, prefix_len) == 0) {
++        name_str += prefix_len;
++      }
++    }
++    return name_str;
++  }
++
++  // Strip any prefixes off the old native method, then try to find a
++  // (possibly prefixed) new native that matches it.
++  methodOop strip_and_search_for_new_native(methodOop method) {
++    ResourceMark rm;
++    char* name_str = method_name_without_prefixes(method);
++    return search_prefix_name_space(0, name_str, strlen(name_str),
++      method->signature());
++  }
++
++public:
++
++  // Construct a native method transfer processor for this class.
++  TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
++    assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
++
++    the_class = _the_class;
++    prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
++  }
++
++  // Attempt to transfer any of the old or deleted methods that are native
++  void transfer_registrations(instanceKlassHandle old_klass, int* old_methods, int methods_length) {
++    for (int j = 0; j < methods_length; j++) {
++      methodOop old_method = (methodOop)old_klass->methods()->obj_at(old_methods[j]);
++
++      if (old_method->is_native() && old_method->has_native_function()) {
++        methodOop new_method = strip_and_search_for_new_native(old_method);
++        if (new_method != NULL) {
++          // Actually set the native function in the new method.
++          // Redefine does not send events (except CFLH), certainly not this
++          // behind the scenes re-registration.
++          new_method->set_native_function(old_method->native_function(),
++            !methodOopDesc::native_bind_event_is_interesting);
++
++          RC_TRACE(0x00008000, ("Transferring native function for method %s", old_method->name()->as_C_string()));
++        }
++      }
++    }
+   }
++};
++
++// Don't lose the association between a native method and its JNI function.
++void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle old_klass) {
++  TransferNativeFunctionRegistration transfer(old_klass);
++  transfer.transfer_registrations(old_klass, _deleted_methods, _deleted_methods_length);
++  transfer.transfer_registrations(old_klass, _matching_old_methods, _matching_methods_length);
+ }
+diff --git a/src/share/vm/prims/jvmtiRedefineClasses.hpp b/src/share/vm/prims/jvmtiRedefineClasses.hpp
+index bfac62c..d7ba79f 100644
+--- a/src/share/vm/prims/jvmtiRedefineClasses.hpp
++++ b/src/share/vm/prims/jvmtiRedefineClasses.hpp
+@@ -1,26 +1,29 @@
+ /*
+- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+- *
+- * This code is free software; you can redistribute it and/or modify it
+- * under the terms of the GNU General Public License version 2 only, as
+- * published by the Free Software Foundation.
+- *
+- * This code is distributed in the hope that it will be useful, but WITHOUT
+- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+- * version 2 for more details (a copy is included in the LICENSE file that
+- * accompanied this code).
+- *
+- * You should have received a copy of the GNU General Public License version
+- * 2 along with this work; if not, write to the Free Software Foundation,
+- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+- *
+- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+- * or visit www.oracle.com if you need additional information or have any
+- * questions.
+- *
+- */
++* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
++* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
++*
++* This code is free software; you can redistribute it and/or modify it
++* under the terms of the GNU General Public License version 2 only, as
++* published by the Free Software Foundation.
++*
++* This code is distributed in the hope that it will be useful, but WITHOUT
++* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
++* version 2 for more details (a copy is included in the LICENSE file that
++* accompanied this code).
++*
++* You should have received a copy of the GNU General Public License version
++* 2 along with this work; if not, write to the Free Software Foundation,
++* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
++*
++* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
++* or visit www.oracle.com if you need additional information or have any
++* questions.
++*
++*/
++
++// New version that allows arbitrary changes to already loaded classes.
++// Modifications done by: Thomas Wuerthinger <thomas.wuerthinger@gmail.com>
+ 
+ #ifndef SHARE_VM_PRIMS_JVMTIREDEFINECLASSES_HPP
+ #define SHARE_VM_PRIMS_JVMTIREDEFINECLASSES_HPP
+@@ -32,331 +35,28 @@
+ #include "oops/objArrayOop.hpp"
+ #include "prims/jvmtiRedefineClassesTrace.hpp"
+ #include "runtime/vm_operations.hpp"
++#include "gc_implementation/shared/vmGCOperations.hpp"
+ 
+-// Introduction:
+-//
+-// The RedefineClasses() API is used to change the definition of one or
+-// more classes. While the API supports redefining more than one class
+-// in a single call, in general, the API is discussed in the context of
+-// changing the definition of a single current class to a single new
+-// class. For clarity, the current class is will always be called
+-// "the_class" and the new class will always be called "scratch_class".
+-//
+-// The name "the_class" is used because there is only one structure
+-// that represents a specific class; redefinition does not replace the
+-// structure, but instead replaces parts of the structure. The name
+-// "scratch_class" is used because the structure that represents the
+-// new definition of a specific class is simply used to carry around
+-// the parts of the new definition until they are used to replace the
+-// appropriate parts in the_class. Once redefinition of a class is
+-// complete, scratch_class is thrown away.
+-//
+-//
+-// Implementation Overview:
+-//
+-// The RedefineClasses() API is mostly a wrapper around the VM op that
+-// does the real work. The work is split in varying degrees between
+-// doit_prologue(), doit() and doit_epilogue().
+-//
+-// 1) doit_prologue() is called by the JavaThread on the way to a
+-//    safepoint. It does parameter verification and loads scratch_class
+-//    which involves:
+-//    - parsing the incoming class definition using the_class' class
+-//      loader and security context
+-//    - linking scratch_class
+-//    - merging constant pools and rewriting bytecodes as needed
+-//      for the merged constant pool
+-//    - verifying the bytecodes in scratch_class
+-//    - setting up the constant pool cache and rewriting bytecodes
+-//      as needed to use the cache
+-//    - finally, scratch_class is compared to the_class to verify
+-//      that it is a valid replacement class
+-//    - if everything is good, then scratch_class is saved in an
+-//      instance field in the VM operation for the doit() call
+-//
+-//    Note: A JavaThread must do the above work.
+-//
+-// 2) doit() is called by the VMThread during a safepoint. It installs
+-//    the new class definition(s) which involves:
+-//    - retrieving the scratch_class from the instance field in the
+-//      VM operation
+-//    - house keeping (flushing breakpoints and caches, deoptimizing
+-//      dependent compiled code)
+-//    - replacing parts in the_class with parts from scratch_class
+-//    - adding weak reference(s) to track the obsolete but interesting
+-//      parts of the_class
+-//    - adjusting constant pool caches and vtables in other classes
+-//      that refer to methods in the_class. These adjustments use the
+-//      SystemDictionary::classes_do() facility which only allows
+-//      a helper method to be specified. The interesting parameters
+-//      that we would like to pass to the helper method are saved in
+-//      static global fields in the VM operation.
+-//    - telling the SystemDictionary to notice our changes
+-//
+-//    Note: the above work must be done by the VMThread to be safe.
+-//
+-// 3) doit_epilogue() is called by the JavaThread after the VM op
+-//    is finished and the safepoint is done. It simply cleans up
+-//    memory allocated in doit_prologue() and used in doit().
+-//
+-//
+-// Constant Pool Details:
+-//
+-// When the_class is redefined, we cannot just replace the constant
+-// pool in the_class with the constant pool from scratch_class because
+-// that could confuse obsolete methods that may still be running.
+-// Instead, the constant pool from the_class, old_cp, is merged with
+-// the constant pool from scratch_class, scratch_cp. The resulting
+-// constant pool, merge_cp, replaces old_cp in the_class.
+-//
+-// The key part of any merging algorithm is the entry comparison
+-// function so we have to know the types of entries in a constant pool
+-// in order to merge two of them together. Constant pools can contain
+-// up to 12 different kinds of entries; the JVM_CONSTANT_Unicode entry
+-// is not presently used so we only have to worry about the other 11
+-// entry types. For the purposes of constant pool merging, it is
+-// helpful to know that the 11 entry types fall into 3 different
+-// subtypes: "direct", "indirect" and "double-indirect".
+-//
+-// Direct CP entries contain data and do not contain references to
+-// other CP entries. The following are direct CP entries:
+-//     JVM_CONSTANT_{Double,Float,Integer,Long,Utf8}
+-//
+-// Indirect CP entries contain 1 or 2 references to a direct CP entry
+-// and no other data. The following are indirect CP entries:
+-//     JVM_CONSTANT_{Class,NameAndType,String}
+-//
+-// Double-indirect CP entries contain two references to indirect CP
+-// entries and no other data. The following are double-indirect CP
+-// entries:
+-//     JVM_CONSTANT_{Fieldref,InterfaceMethodref,Methodref}
+-//
+-// When comparing entries between two constant pools, the entry types
+-// are compared first and if they match, then further comparisons are
+-// made depending on the entry subtype. Comparing direct CP entries is
+-// simply a matter of comparing the data associated with each entry.
+-// Comparing both indirect and double-indirect CP entries requires
+-// recursion.
+-//
+-// Fortunately, the recursive combinations are limited because indirect
+-// CP entries can only refer to direct CP entries and double-indirect
+-// CP entries can only refer to indirect CP entries. The following is
+-// an example illustration of the deepest set of indirections needed to
+-// access the data associated with a JVM_CONSTANT_Fieldref entry:
+-//
+-//     JVM_CONSTANT_Fieldref {
+-//         class_index => JVM_CONSTANT_Class {
+-//             name_index => JVM_CONSTANT_Utf8 {
+-//                 <data-1>
+-//             }
+-//         }
+-//         name_and_type_index => JVM_CONSTANT_NameAndType {
+-//             name_index => JVM_CONSTANT_Utf8 {
+-//                 <data-2>
+-//             }
+-//             descriptor_index => JVM_CONSTANT_Utf8 {
+-//                 <data-3>
+-//             }
+-//         }
+-//     }
+-//
+-// The above illustration is not a data structure definition for any
+-// computer language. The curly braces ('{' and '}') are meant to
+-// delimit the context of the "fields" in the CP entry types shown.
+-// Each indirection from the JVM_CONSTANT_Fieldref entry is shown via
+-// "=>", e.g., the class_index is used to indirectly reference a
+-// JVM_CONSTANT_Class entry where the name_index is used to indirectly
+-// reference a JVM_CONSTANT_Utf8 entry which contains the interesting
+-// <data-1>. In order to understand a JVM_CONSTANT_Fieldref entry, we
+-// have to do a total of 5 indirections just to get to the CP entries
+-// that contain the interesting pieces of data and then we have to
+-// fetch the three pieces of data. This means we have to do a total of
+-// (5 + 3) * 2 == 16 dereferences to compare two JVM_CONSTANT_Fieldref
+-// entries.
+-//
+-// Here is the indirection, data and dereference count for each entry
+-// type:
+-//
+-//    JVM_CONSTANT_Class               1 indir, 1 data, 2 derefs
+-//    JVM_CONSTANT_Double              0 indir, 1 data, 1 deref
+-//    JVM_CONSTANT_Fieldref            2 indir, 3 data, 8 derefs
+-//    JVM_CONSTANT_Float               0 indir, 1 data, 1 deref
+-//    JVM_CONSTANT_Integer             0 indir, 1 data, 1 deref
+-//    JVM_CONSTANT_InterfaceMethodref  2 indir, 3 data, 8 derefs
+-//    JVM_CONSTANT_Long                0 indir, 1 data, 1 deref
+-//    JVM_CONSTANT_Methodref           2 indir, 3 data, 8 derefs
+-//    JVM_CONSTANT_NameAndType         1 indir, 2 data, 4 derefs
+-//    JVM_CONSTANT_String              1 indir, 1 data, 2 derefs
+-//    JVM_CONSTANT_Utf8                0 indir, 1 data, 1 deref
+-//
+-// So different subtypes of CP entries require different amounts of
+-// work for a proper comparison.
+-//
+-// Now that we've talked about the different entry types and how to
+-// compare them we need to get back to merging. This is not a merge in
+-// the "sort -u" sense or even in the "sort" sense. When we merge two
+-// constant pools, we copy all the entries from old_cp to merge_cp,
+-// preserving entry order. Next we append all the unique entries from
+-// scratch_cp to merge_cp and we track the index changes from the
+-// location in scratch_cp to the possibly new location in merge_cp.
+-// When we are done, any obsolete code that is still running that
+-// uses old_cp should not be able to observe any difference if it
+-// were to use merge_cp. As for the new code in scratch_class, it is
+-// modified to use the appropriate index values in merge_cp before it
+-// is used to replace the code in the_class.
+-//
+-// There is one small complication in copying the entries from old_cp
+-// to merge_cp. Two of the CP entry types are special in that they are
+-// lazily resolved. Before explaining the copying complication, we need
+-// to digress into CP entry resolution.
+-//
+-// JVM_CONSTANT_Class and JVM_CONSTANT_String entries are present in
+-// the class file, but are not stored in memory as such until they are
+-// resolved. The entries are not resolved unless they are used because
+-// resolution is expensive. During class file parsing the entries are
+-// initially stored in memory as JVM_CONSTANT_ClassIndex and
+-// JVM_CONSTANT_StringIndex entries. These special CP entry types
+-// indicate that the JVM_CONSTANT_Class and JVM_CONSTANT_String entries
+-// have been parsed, but the index values in the entries have not been
+-// validated. After the entire constant pool has been parsed, the index
+-// values can be validated and then the entries are converted into
+-// JVM_CONSTANT_UnresolvedClass and JVM_CONSTANT_UnresolvedString
+-// entries. During this conversion process, the UTF8 values that are
+-// indirectly referenced by the JVM_CONSTANT_ClassIndex and
+-// JVM_CONSTANT_StringIndex entries are changed into Symbol*s and the
+-// entries are modified to refer to the Symbol*s. This optimization
+-// eliminates one level of indirection for those two CP entry types and
+-// gets the entries ready for verification. During class file parsing
+-// it is also possible for JVM_CONSTANT_UnresolvedString entries to be
+-// resolved into JVM_CONSTANT_String entries. Verification expects to
+-// find JVM_CONSTANT_UnresolvedClass and either JVM_CONSTANT_String or
+-// JVM_CONSTANT_UnresolvedString entries and not JVM_CONSTANT_Class
+-// entries.
+-//
+-// Now we can get back to the copying complication. When we copy
+-// entries from old_cp to merge_cp, we have to revert any
+-// JVM_CONSTANT_Class entries to JVM_CONSTANT_UnresolvedClass entries
+-// or verification will fail.
+-//
+-// It is important to explicitly state that the merging algorithm
+-// effectively unresolves JVM_CONSTANT_Class entries that were in the
+-// old_cp when they are changed into JVM_CONSTANT_UnresolvedClass
+-// entries in the merge_cp. This is done both to make verification
+-// happy and to avoid adding more brittleness between RedefineClasses
+-// and the constant pool cache. By allowing the constant pool cache
+-// implementation to (re)resolve JVM_CONSTANT_UnresolvedClass entries
+-// into JVM_CONSTANT_Class entries, we avoid having to embed knowledge
+-// about those algorithms in RedefineClasses.
+-//
+-// Appending unique entries from scratch_cp to merge_cp is straight
+-// forward for direct CP entries and most indirect CP entries. For the
+-// indirect CP entry type JVM_CONSTANT_NameAndType and for the double-
+-// indirect CP entry types, the presence of more than one piece of
+-// interesting data makes appending the entries more complicated.
+-//
+-// For the JVM_CONSTANT_{Double,Float,Integer,Long,Utf8} entry types,
+-// the entry is simply copied from scratch_cp to the end of merge_cp.
+-// If the index in scratch_cp is different than the destination index
+-// in merge_cp, then the change in index value is tracked.
+-//
+-// Note: the above discussion for the direct CP entries also applies
+-// to the JVM_CONSTANT_Unresolved{Class,String} entry types.
+-//
+-// For the JVM_CONSTANT_{Class,String} entry types, since there is only
+-// one data element at the end of the recursion, we know that we have
+-// either one or two unique entries. If the JVM_CONSTANT_Utf8 entry is
+-// unique then it is appended to merge_cp before the current entry.
+-// If the JVM_CONSTANT_Utf8 entry is not unique, then the current entry
+-// is updated to refer to the duplicate entry in merge_cp before it is
+-// appended to merge_cp. Again, any changes in index values are tracked
+-// as needed.
+-//
+-// Note: the above discussion for JVM_CONSTANT_{Class,String} entry
+-// types is theoretical. Since those entry types have already been
+-// optimized into JVM_CONSTANT_Unresolved{Class,String} entry types,
+-// they are handled as direct CP entries.
+-//
+-// For the JVM_CONSTANT_NameAndType entry type, since there are two
+-// data elements at the end of the recursions, we know that we have
+-// between one and three unique entries. Any unique JVM_CONSTANT_Utf8
+-// entries are appended to merge_cp before the current entry. For any
+-// JVM_CONSTANT_Utf8 entries that are not unique, the current entry is
+-// updated to refer to the duplicate entry in merge_cp before it is
+-// appended to merge_cp. Again, any changes in index values are tracked
+-// as needed.
+-//
+-// For the JVM_CONSTANT_{Fieldref,InterfaceMethodref,Methodref} entry
+-// types, since there are two indirect CP entries and three data
+-// elements at the end of the recursions, we know that we have between
+-// one and six unique entries. See the JVM_CONSTANT_Fieldref diagram
+-// above for an example of all six entries. The uniqueness algorithm
+-// for the JVM_CONSTANT_Class and JVM_CONSTANT_NameAndType entries is
+-// covered above. Any unique entries are appended to merge_cp before
+-// the current entry. For any entries that are not unique, the current
+-// entry is updated to refer to the duplicate entry in merge_cp before
+-// it is appended to merge_cp. Again, any changes in index values are
+-// tracked as needed.
+-//
+-//
+-// Other Details:
+-//
+-// Details for other parts of RedefineClasses need to be written.
+-// This is a placeholder section.
+-//
+-//
+-// Open Issues (in no particular order):
+-//
+-// - How do we serialize the RedefineClasses() API without deadlocking?
+-//
+-// - SystemDictionary::parse_stream() was called with a NULL protection
+-//   domain since the initial version. This has been changed to pass
+-//   the_class->protection_domain(). This change has been tested with
+-//   all NSK tests and nothing broke, but what will adding it now break
+-//   in ways that we don't test?
+-//
+-// - GenerateOopMap::rewrite_load_or_store() has a comment in its
+-//   (indirect) use of the Relocator class that the max instruction
+-//   size is 4 bytes. goto_w and jsr_w are 5 bytes and wide/iinc is
+-//   6 bytes. Perhaps Relocator only needs a 4 byte buffer to do
+-//   what it does to the bytecodes. More investigation is needed.
+-//
+-// - java.lang.Object methods can be called on arrays. This is
+-//   implemented via the arrayKlassOop vtable which we don't
+-//   update. For example, if we redefine java.lang.Object.toString(),
+-//   then the new version of the method will not be called for array
+-//   objects.
+-//
+-// - How do we know if redefine_single_class() and the guts of
+-//   instanceKlass are out of sync? I don't think this can be
+-//   automated, but we should probably order the work in
+-//   redefine_single_class() to match the order of field
+-//   definitions in instanceKlass. We also need to add some
+-//   comments about keeping things in sync.
+-//
+-// - set_new_constant_pool() is huge and we should consider refactoring
+-//   it into smaller chunks of work.
+-//
+-// - The exception table update code in set_new_constant_pool() defines
+-//   const values that are also defined in a local context elsewhere.
+-//   The same literal values are also used in elsewhere. We need to
+-//   coordinate a cleanup of these constants with Runtime.
+-//
+-
+-class VM_RedefineClasses: public VM_Operation {
++#define RC_ABORT(error) { _result = error; return false; }
++
++class VM_RedefineClasses: public VM_GC_Operation {
+  private:
++
+   // These static fields are needed by SystemDictionary::classes_do()
+   // facility and the adjust_cpool_cache_and_vtable() helper:
+   static objArrayOop     _old_methods;
+   static objArrayOop     _new_methods;
+-  static methodOop*      _matching_old_methods;
+-  static methodOop*      _matching_new_methods;
+-  static methodOop*      _deleted_methods;
+-  static methodOop*      _added_methods;
++  static int*            _matching_old_methods;
++  static int*            _matching_new_methods;
++  static int*            _deleted_methods;
++  static int*            _added_methods;
+   static int             _matching_methods_length;
+   static int             _deleted_methods_length;
+   static int             _added_methods_length;
+   static klassOop        _the_class_oop;
+ 
++  static int             _revision_number;
++
+   // The instance fields are used to pass information from
+   // doit_prologue() to doit() and doit_epilogue().
+   jint                        _class_count;
+@@ -370,43 +70,29 @@ class VM_RedefineClasses: public VM_Operation {
+   // _index_map_p contains any entries.
+   int                         _index_map_count;
+   intArray *                  _index_map_p;
+-
+-  // _operands_index_map_count is just an optimization for knowing if
+-  // _operands_index_map_p contains any entries.
+-  int                         _operands_cur_length;
+-  int                         _operands_index_map_count;
+-  intArray *                  _operands_index_map_p;
+-
+-  // ptr to _class_count scratch_classes
+-  instanceKlassHandle *       _scratch_classes;
+-  jvmtiError                  _res;
++  GrowableArray<instanceKlassHandle>* _new_classes;
++  GrowableArray<oop>*         _updated_oops;
++  jvmtiError                  _result;
++  int                         _max_redefinition_flags;
+ 
+   // Performance measurement support. These timers do not cover all
+   // the work done for JVM/TI RedefineClasses() but they do cover
+   // the heavy lifting.
+-  elapsedTimer  _timer_rsc_phase1;
+-  elapsedTimer  _timer_rsc_phase2;
+-  elapsedTimer  _timer_vm_op_prologue;
+-
+-  // These routines are roughly in call order unless otherwise noted.
+-
+-  // Load the caller's new class definition(s) into _scratch_classes.
+-  // Constant pool merging work is done here as needed. Also calls
+-  // compare_and_normalize_class_versions() to verify the class
+-  // definition(s).
++  elapsedTimer _timer_total;
++  elapsedTimer _timer_prologue;
++  elapsedTimer _timer_class_linking;
++  elapsedTimer _timer_class_loading;
++  elapsedTimer _timer_check_type;
++  elapsedTimer _timer_prepare_redefinition;
++  elapsedTimer _timer_wait_for_locks;
++  elapsedTimer _timer_redefinition;
++  elapsedTimer _timer_vm_op_epilogue;
++
++  jvmtiError check_redefinition_allowed(instanceKlassHandle new_class);
++  jvmtiError find_sorted_affected_classes(GrowableArray<instanceKlassHandle> *all_affected_klasses);
++  jvmtiError find_class_bytes(instanceKlassHandle the_class, const unsigned char **class_bytes, jint *class_byte_count, jboolean *not_changed);
+   jvmtiError load_new_class_versions(TRAPS);
+ 
+-  // Verify that the caller provided class definition(s) that meet
+-  // the restrictions of RedefineClasses. Normalize the order of
+-  // overloaded methods as needed.
+-  jvmtiError compare_and_normalize_class_versions(
+-    instanceKlassHandle the_class, instanceKlassHandle scratch_class);
+-
+-  // Swap annotations[i] with annotations[j]
+-  // Used by compare_and_normalize_class_versions() when normalizing
+-  // overloaded methods or changing idnum as when adding or deleting methods.
+-  void swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class);
+-
+   // Figure out which new methods match old methods in name and signature,
+   // which methods have been added, and which are no longer present
+   void compute_added_deleted_matching_methods();
+@@ -414,103 +100,99 @@ class VM_RedefineClasses: public VM_Operation {
+   // Change jmethodIDs to point to the new methods
+   void update_jmethod_ids();
+ 
+-  // In addition to marking methods as obsolete, this routine
+-  // records which methods are EMCP (Equivalent Module Constant
+-  // Pool) in the emcp_methods BitMap and returns the number of
+-  // EMCP methods via emcp_method_count_p. This information is
+-  // used when information about the previous version of the_class
+-  // is squirreled away.
+-  void check_methods_and_mark_as_obsolete(BitMap *emcp_methods,
+-         int * emcp_method_count_p);
+-  void transfer_old_native_function_registrations(instanceKlassHandle the_class);
++  class FindAffectedKlassesClosure : public ObjectClosure {
++
++  private:
++    GrowableArray<instanceKlassHandle> *_original_klasses;
++    GrowableArray<instanceKlassHandle> *_result;
++
++  public:
++    FindAffectedKlassesClosure(GrowableArray<instanceKlassHandle> *original_klasses, GrowableArray<instanceKlassHandle> *result);
++   
++    virtual void do_object(oop obj);
++  };
+ 
+-  // Unevolving classes may point to methods of the_class directly
+-  // from their constant pool caches, itables, and/or vtables. We
+-  // use the SystemDictionary::classes_do() facility and this helper
+-  // to fix up these pointers.
+-  static void adjust_cpool_cache_and_vtable(klassOop k_oop, oop loader, TRAPS);
++
++  static jvmtiError do_topological_class_sorting(const jvmtiClassDefinition *class_definitions, int class_count, GrowableArray<instanceKlassHandle> *affected, GrowableArray<instanceKlassHandle> *arr, TRAPS);
+ 
+   // Install the redefinition of a class
+-  void redefine_single_class(jclass the_jclass,
+-    instanceKlassHandle scratch_class, TRAPS);
++  void redefine_single_class(instanceKlassHandle the_new_class, TRAPS);
+ 
+   // Increment the classRedefinedCount field in the specific instanceKlass
+   // and in all direct and indirect subclasses.
+   void increment_class_counter(instanceKlass *ik, TRAPS);
+ 
+-  // Support for constant pool merging (these routines are in alpha order):
+-  void append_entry(constantPoolHandle scratch_cp, int scratch_i,
+-    constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS);
+-  void append_operand(constantPoolHandle scratch_cp, int scratch_bootstrap_spec_index,
+-    constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS);
+-  void finalize_operands_merge(constantPoolHandle merge_cp, TRAPS);
+-  int find_or_append_indirect_entry(constantPoolHandle scratch_cp, int scratch_i,
+-    constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS);
+-  int find_or_append_operand(constantPoolHandle scratch_cp, int scratch_bootstrap_spec_index,
+-    constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS);
+-  int find_new_index(int old_index);
+-  int find_new_operand_index(int old_bootstrap_spec_index);
+-  bool is_unresolved_class_mismatch(constantPoolHandle cp1, int index1,
+-    constantPoolHandle cp2, int index2);
+-  bool is_unresolved_string_mismatch(constantPoolHandle cp1, int index1,
+-    constantPoolHandle cp2, int index2);
+-  void map_index(constantPoolHandle scratch_cp, int old_index, int new_index);
+-  void map_operand_index(int old_bootstrap_spec_index, int new_bootstrap_spec_index);
+-  bool merge_constant_pools(constantPoolHandle old_cp,
+-    constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
+-    int *merge_cp_length_p, TRAPS);
+-  jvmtiError merge_cp_and_rewrite(instanceKlassHandle the_class,
+-    instanceKlassHandle scratch_class, TRAPS);
+-  u2 rewrite_cp_ref_in_annotation_data(
+-    typeArrayHandle annotations_typeArray, int &byte_i_ref,
+-    const char * trace_mesg, TRAPS);
+-  bool rewrite_cp_refs(instanceKlassHandle scratch_class, TRAPS);
+-  bool rewrite_cp_refs_in_annotation_struct(
+-    typeArrayHandle class_annotations, int &byte_i_ref, TRAPS);
+-  bool rewrite_cp_refs_in_annotations_typeArray(
+-    typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS);
+-  bool rewrite_cp_refs_in_class_annotations(
+-    instanceKlassHandle scratch_class, TRAPS);
+-  bool rewrite_cp_refs_in_element_value(
+-    typeArrayHandle class_annotations, int &byte_i_ref, TRAPS);
+-  bool rewrite_cp_refs_in_fields_annotations(
+-    instanceKlassHandle scratch_class, TRAPS);
+-  void rewrite_cp_refs_in_method(methodHandle method,
+-    methodHandle * new_method_p, TRAPS);
+-  bool rewrite_cp_refs_in_methods(instanceKlassHandle scratch_class, TRAPS);
+-  bool rewrite_cp_refs_in_methods_annotations(
+-    instanceKlassHandle scratch_class, TRAPS);
+-  bool rewrite_cp_refs_in_methods_default_annotations(
+-    instanceKlassHandle scratch_class, TRAPS);
+-  bool rewrite_cp_refs_in_methods_parameter_annotations(
+-    instanceKlassHandle scratch_class, TRAPS);
+-  void rewrite_cp_refs_in_stack_map_table(methodHandle method, TRAPS);
+-  void rewrite_cp_refs_in_verification_type_info(
+-         address& stackmap_addr_ref, address stackmap_end, u2 frame_i,
+-         u1 frame_size, TRAPS);
+-  void set_new_constant_pool(instanceKlassHandle scratch_class,
+-    constantPoolHandle scratch_cp, int scratch_cp_length, TRAPS);
+ 
+   void flush_dependent_code(instanceKlassHandle k_h, TRAPS);
+ 
+-  static void check_class(klassOop k_oop, oop initiating_loader, TRAPS);
+-  static void dump_methods();
++  static void check_class(klassOop k_oop,/* oop initiating_loader,*/ TRAPS) PRODUCT_RETURN;
++
++  static void adjust_cpool_cache(klassOop k_oop, oop initiating_loader, TRAPS);
++
++#ifdef ASSERT
++  static void verify_classes(klassOop k_oop, oop initiating_loader, TRAPS);
++#endif
++
++  int calculate_redefinition_flags(instanceKlassHandle new_version);
++  void calculate_instance_update_information(klassOop new_version);
++  void check_methods_and_mark_as_obsolete(BitMap *emcp_methods, int * emcp_method_count_p);
++
++  static void calculate_type_check_information(klassOop k);
++  static void clear_type_check_information(klassOop k);
+ 
+  public:
+-  VM_RedefineClasses(jint class_count,
+-                     const jvmtiClassDefinition *class_defs,
+-                     JvmtiClassLoadKind class_load_kind);
+-  VMOp_Type type() const { return VMOp_RedefineClasses; }
++  VM_RedefineClasses(jint class_count, const jvmtiClassDefinition *class_defs, JvmtiClassLoadKind class_load_kind);
++  virtual ~VM_RedefineClasses();
++  
++  bool check_arguments();
+   bool doit_prologue();
+   void doit();
+   void doit_epilogue();
++  void rollback();
++
++  jvmtiError check_exception() const;
++  VMOp_Type type() const                         { return VMOp_RedefineClasses; }
++  bool skip_operation() const                    { return false; }
++  bool allow_nested_vm_operations() const        { return true;  }
++  jvmtiError check_error()                       { return _result;  }
++
++  void update_active_methods();
+ 
+-  bool allow_nested_vm_operations() const        { return true; }
+-  jvmtiError check_error()                       { return _res; }
++  // Checks for type consistency after hierarchy change
++  bool check_type_consistency();
++  void calculate_type_check_information();
++  bool check_field_value_types();
++  void clear_type_check_information();
++  bool check_method_stacks();
++  bool check_loaded_methods();
++  bool check_method(methodOop method);
++  static Symbol* signature_to_class_name(Symbol* signature);
++
++  void method_forwarding();
++
++  void update_array_classes_to_newest_version(klassOop smallest_dimension);
+ 
+   // Modifiable test must be shared between IsModifiableClass query
+   // and redefine implementation
+   static bool is_modifiable_class(oop klass_mirror);
++
++  // Method used during garbage collection, the VM operation must iterate over all oops.
++  void oops_do(OopClosure* f);
++
++  // Utility methods for transferring field access flags
++
++  static void transfer_special_access_flags(fieldDescriptor *from, fieldDescriptor *to);
++  static void update_klass_field_access_flag(fieldDescriptor *fd);
++
++  void transfer_old_native_function_registrations(instanceKlassHandle the_class);
++
++  void lock_threads();
++  void unlock_threads();
++
++  template <class T> static void do_oop_work(T* p);
++
++  static void swap_marks(oop first, oop second);
++
+ };
+ 
+ #endif // SHARE_VM_PRIMS_JVMTIREDEFINECLASSES_HPP
+diff --git a/src/share/vm/prims/methodComparator.cpp b/src/share/vm/prims/methodComparator.cpp
+index 60eaf97..07bb6e3 100644
+--- a/src/share/vm/prims/methodComparator.cpp
++++ b/src/share/vm/prims/methodComparator.cpp
+@@ -65,6 +65,7 @@ bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method)
+     if (! args_same(c_old, c_new))
+       return false;
+   }
++
+   return true;
+ }
+ 
+diff --git a/src/share/vm/prims/nativeLookup.cpp b/src/share/vm/prims/nativeLookup.cpp
+index 41fc42d..53b3e0c 100644
+--- a/src/share/vm/prims/nativeLookup.cpp
++++ b/src/share/vm/prims/nativeLookup.cpp
+@@ -35,6 +35,7 @@
+ #include "oops/symbol.hpp"
+ #include "prims/jvm_misc.hpp"
+ #include "prims/nativeLookup.hpp"
++#include "prims/jvmtiRedefineClasses.hpp"
+ #include "runtime/arguments.hpp"
+ #include "runtime/handles.inline.hpp"
+ #include "runtime/javaCalls.hpp"
+@@ -53,7 +54,6 @@
+ # include "os_bsd.inline.hpp"
+ #endif
+ 
+-
+ static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) {
+   char* bytes = (char*)name->bytes() + begin;
+   char* end_bytes = (char*)name->bytes() + end;
+@@ -138,6 +138,40 @@ static JNINativeMethod lookup_special_native_methods[] = {
+   { CC"Java_sun_hotspot_WhiteBox_registerNatives",                 NULL, FN_PTR(JVM_RegisterWhiteBoxMethods)     },
+ };
+ 
++// Helper function to call redefineClasses from Java Code
++JVM_ENTRY(int, JVM_RedefineClassesHelper(JNIEnv *env, jclass cb, jclass target, jbyteArray bytes))
++  ResourceMark rm(THREAD);
++
++  JavaThread* current_thread = JavaThread::current();
++  jbyte* bytecodes = NULL;
++  const int class_count = 1;
++  jvmtiClassDefinition* class_definitions = NEW_RESOURCE_ARRAY(jvmtiClassDefinition, class_count);
++  
++  {
++     ThreadToNativeFromVM ttnfv(thread);
++     jboolean is_copy = JNI_FALSE;
++     bytecodes = env->GetByteArrayElements(bytes, &is_copy);
++     class_definitions[0].klass = target;
++     class_definitions[0].class_byte_count = env->GetArrayLength(bytes);
++     class_definitions[0].class_bytes = (unsigned char*)bytecodes;
++  }
++
++  VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
++  VMThread::execute(&op);
++  int result = op.check_error();
++
++  {
++    ThreadToNativeFromVM ttnfv(thread);
++    if (env->ExceptionOccurred()) {
++      return -1;
++    }
++    env->ReleaseByteArrayElements(bytes, bytecodes, 0);
++  }
++
++ return result;
++JVM_END
++
++
+ static address lookup_special_native(char* jni_name) {
+   int i = !JDK_Version::is_gte_jdk14x_version() ? 0 : 2;  // see comment in lookup_special_native_methods
+   int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
+@@ -177,6 +211,9 @@ address NativeLookup::lookup_style(methodHandle method, char* pure_name, const c
+       return entry;
+     }
+   }
++  if(strstr(jni_name, "Java_at_ssw_hotswap_ClassRedefinition_redefineClasses") != NULL) {
++		return CAST_FROM_FN_PTR(address, JVM_RedefineClassesHelper);
++  }
+ 
+   // Otherwise call static method findNative in ClassLoader
+   KlassHandle   klass (THREAD, SystemDictionary::ClassLoader_klass());
+diff --git a/src/share/vm/runtime/arguments.cpp b/src/share/vm/runtime/arguments.cpp
+index ec79354..541bf0f 100644
+--- a/src/share/vm/runtime/arguments.cpp
++++ b/src/share/vm/runtime/arguments.cpp
+@@ -1831,6 +1831,15 @@ bool Arguments::check_gc_consistency() {
+     status = false;
+   }
+ 
++  // (tw) Must use serial GC
++  if (!UseSerialGC && i >= 1) {
++    jio_fprintf(defaultStream::error_stream(),
++      "Must use the serial GC in the Dynamic Code Evolution VM\n");
++    status = false;
++  } else {
++    UseSerialGC = true;
++  }
++
+   return status;
+ }
+ 
+diff --git a/src/share/vm/runtime/deoptimization.cpp b/src/share/vm/runtime/deoptimization.cpp
+index 2b767d4..e9b6f47 100644
+--- a/src/share/vm/runtime/deoptimization.cpp
++++ b/src/share/vm/runtime/deoptimization.cpp
+@@ -599,6 +599,38 @@ JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_m
+   // Cleanup thread deopt data
+   cleanup_deopt_info(thread, array);
+ 
++  // (tw) Redefinition support: Check if we need to transfer method execution points to new versions
++  {
++    ResourceMark res_mark;
++
++    // Verify that the just-unpacked frames match the interpreter's
++    // notions of expression stack and locals
++    vframeArray* cur_array = thread->vframe_array_last();
++    RegisterMap rm(thread, false);
++    rm.set_include_argument_oops(false);
++    for (int i = 0; i < cur_array->frames(); i++) {
++      vframeArrayElement* el = cur_array->element(i);
++      frame* frame = el->iframe();
++      guarantee(frame->is_interpreted_frame(), "Wrong frame type");
++      RegisterMap reg_map(thread);
++      vframe* vf = vframe::new_vframe(frame, &reg_map, thread);
++      interpretedVFrame *iframe = (interpretedVFrame *)vf;
++      methodOop method = iframe->method();
++      int bci = iframe->bci();
++      method = method->newest_version();
++      iframe->set_method(method, bci);
++
++      methodOop forward_method = method->forward_method();
++      if (forward_method != NULL && method->is_in_code_section(bci)) {
++        int new_bci = method->calculate_forward_bci(bci, forward_method);
++        if (TraceRedefineClasses >= 2) {
++          tty->print_cr("Transferring execution of %s to new method old_bci=%d new_bci=%d", forward_method->name()->as_C_string(), bci, new_bci);
++        }
++        iframe->set_method(forward_method, new_bci);
++      }
++    }
++  }
++
+ #ifndef PRODUCT
+   if (VerifyStack) {
+     ResourceMark res_mark;
+diff --git a/src/share/vm/runtime/frame.cpp b/src/share/vm/runtime/frame.cpp
+index aacd835..3772b3f 100644
+--- a/src/share/vm/runtime/frame.cpp
++++ b/src/share/vm/runtime/frame.cpp
+@@ -408,6 +408,12 @@ void frame::interpreter_frame_set_method(methodOop method) {
+   *interpreter_frame_method_addr() = method;
+ }
+ 
++// (tw) Sets constant pool cache oop
++void frame::interpreter_frame_set_cache(constantPoolCacheOop cp) {
++  assert(is_interpreted_frame(), "interpreted frame expected");
++  *interpreter_frame_cache_addr() = cp;
++}
++
+ void frame::interpreter_frame_set_bcx(intptr_t bcx) {
+   assert(is_interpreted_frame(), "Not an interpreted frame");
+   if (ProfileInterpreter) {
+@@ -423,19 +429,27 @@ void frame::interpreter_frame_set_bcx(intptr_t bcx) {
+           // The bcx was just converted from bci to bcp.
+           // Convert the mdx in parallel.
+           methodDataOop mdo = interpreter_frame_method()->method_data();
+-          assert(mdo != NULL, "");
+-          int mdi = mdx - 1; // We distinguish valid mdi from zero by adding one.
+-          address mdp = mdo->di_to_dp(mdi);
+-          interpreter_frame_set_mdx((intptr_t)mdp);
++          if (mdo == NULL) {
++            interpreter_frame_set_mdx(0);
++          } else {
++            assert(mdo != NULL, "");
++            int mdi = mdx - 1; // We distinguish valid mdi from zero by adding one.
++            address mdp = mdo->di_to_dp(mdi);
++            interpreter_frame_set_mdx((intptr_t)mdp);
++          }
+         }
+       } else {
+         if (is_now_bci) {
+           // The bcx was just converted from bcp to bci.
+           // Convert the mdx in parallel.
+           methodDataOop mdo = interpreter_frame_method()->method_data();
+-          assert(mdo != NULL, "");
+-          int mdi = mdo->dp_to_di((address)mdx);
+-          interpreter_frame_set_mdx((intptr_t)mdi + 1); // distinguish valid from 0.
++          if (mdo == NULL) {
++            interpreter_frame_set_mdx(0);
++          } else {
++            assert(mdo != NULL, "");
++            int mdi = mdo->dp_to_di((address)mdx);
++            interpreter_frame_set_mdx((intptr_t)mdi + 1); // distinguish valid from 0.
++          }
+         }
+       }
+     }
+diff --git a/src/share/vm/runtime/frame.hpp b/src/share/vm/runtime/frame.hpp
+index 9c7bb72..04a6595 100644
+--- a/src/share/vm/runtime/frame.hpp
++++ b/src/share/vm/runtime/frame.hpp
+@@ -346,6 +346,7 @@ class frame VALUE_OBJ_CLASS_SPEC {
+   // Method & constant pool cache
+   methodOop interpreter_frame_method() const;
+   void interpreter_frame_set_method(methodOop method);
++  void interpreter_frame_set_cache(constantPoolCacheOop method);
+   methodOop* interpreter_frame_method_addr() const;
+   constantPoolCacheOop* interpreter_frame_cache_addr() const;
+ #ifdef PPC
+diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
+index b0179c2..a4e9bd9 100644
+--- a/src/share/vm/runtime/globals.hpp
++++ b/src/share/vm/runtime/globals.hpp
+@@ -1229,9 +1229,23 @@ class CommandLineFlags {
+   product(bool, StressLdcRewrite, false,                                    \
+           "Force ldc -> ldc_w rewrite during RedefineClasses")              \
+                                                                             \
++  product(bool, UseMethodForwardPoints, false,                              \
++          "Use method forward points")                                      \
++                                                                            \
++  product(intx, MethodForwardPointsMaxLocals, 300,                          \
++          "Maximum number of locals in forwarding method")                  \
++                                                                            \
++  product(intx, MethodForwardPointsMaxStack, 300,                           \
++          "Maximum number of stack slots in forwarding method")             \
++                                                                            \
+   product(intx, TraceRedefineClasses, 0,                                    \
+           "Trace level for JVMTI RedefineClasses")                          \
+                                                                             \
++  product(bool, TimeRedefineClasses, false,                                 \
++          "Measure timing for JVMTI RedefineClasses")                       \
++                                                                            \
++  product(bool, AllowAdvancedClassRedefinition, true,                       \
++          "Allow advanced class redefinition beyond swapping method bodies")\
+   develop(bool, StressMethodComparator, false,                              \
+           "run the MethodComparator on all loaded methods")                 \
+                                                                             \
+diff --git a/src/share/vm/runtime/interfaceSupport.hpp b/src/share/vm/runtime/interfaceSupport.hpp
+index 2875ee0..61fd8fe 100644
+--- a/src/share/vm/runtime/interfaceSupport.hpp
++++ b/src/share/vm/runtime/interfaceSupport.hpp
+@@ -296,7 +296,7 @@ class ThreadToNativeFromVM : public ThreadStateTransition {
+   ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {
+     // We are leaving the VM at this point and going directly to native code.
+     // Block, if we are in the middle of a safepoint synchronization.
+-    assert(!thread->owns_locks(), "must release all locks when leaving VM");
++    assert(!thread->owns_locks_but_redefine_classes_lock(), "must release all locks when leaving VM");
+     thread->frame_anchor()->make_walkable(thread);
+     trans_and_fence(_thread_in_vm, _thread_in_native);
+     // Check for pending. async. exceptions or suspends.
+diff --git a/src/share/vm/runtime/javaCalls.cpp b/src/share/vm/runtime/javaCalls.cpp
+index edbba98..4a27925 100644
+--- a/src/share/vm/runtime/javaCalls.cpp
++++ b/src/share/vm/runtime/javaCalls.cpp
+@@ -60,7 +60,7 @@ JavaCallWrapper::JavaCallWrapper(methodHandle callee_method, Handle receiver, Ja
+   bool clear_pending_exception = true;
+ 
+   guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
+-  assert(!thread->owns_locks(), "must release all locks when leaving VM");
++  assert(!thread->owns_locks_but_redefine_classes_lock(), "must release all locks when leaving VM");
+   guarantee(!thread->is_Compiler_thread(), "cannot make java calls from the compiler");
+   _result   = result;
+ 
+diff --git a/src/share/vm/runtime/jniHandles.cpp b/src/share/vm/runtime/jniHandles.cpp
+index 3cbcaca..30839d7 100644
+--- a/src/share/vm/runtime/jniHandles.cpp
++++ b/src/share/vm/runtime/jniHandles.cpp
+@@ -112,6 +112,10 @@ jobject JNIHandles::make_weak_global(Handle obj) {
+ }
+ 
+ jmethodID JNIHandles::make_jmethod_id(methodHandle mh) {
++  if (mh->newest_version() != mh()) {
++    methodHandle mh_new(Thread::current(), mh()->newest_version());
++    return (jmethodID) make_weak_global(mh_new);
++  }
+   return (jmethodID) make_weak_global(mh);
+ }
+ 
+diff --git a/src/share/vm/runtime/mutex.cpp b/src/share/vm/runtime/mutex.cpp
+index 2095237..c541434 100644
+--- a/src/share/vm/runtime/mutex.cpp
++++ b/src/share/vm/runtime/mutex.cpp
+@@ -1227,7 +1227,7 @@ Monitor * Monitor::get_least_ranked_lock(Monitor * locks) {
+     // in increasing rank order (modulo any native ranks)
+     for (tmp = locks; tmp != NULL; tmp = tmp->next()) {
+       if (tmp->next() != NULL) {
+-        assert(tmp->rank() == Mutex::native ||
++        assert(tmp->rank() == Mutex::native || tmp->rank() == Mutex::redefine_classes ||
+                tmp->rank() <= tmp->next()->rank(), "mutex rank anomaly?");
+       }
+     }
+@@ -1247,7 +1247,7 @@ Monitor* Monitor::get_least_ranked_lock_besides_this(Monitor* locks) {
+     // in increasing rank order (modulo any native ranks)
+     for (tmp = locks; tmp != NULL; tmp = tmp->next()) {
+       if (tmp->next() != NULL) {
+-        assert(tmp->rank() == Mutex::native ||
++        assert(tmp->rank() == Mutex::native || tmp->rank() == Mutex::redefine_classes ||
+                tmp->rank() <= tmp->next()->rank(), "mutex rank anomaly?");
+       }
+     }
+@@ -1310,6 +1310,7 @@ void Monitor::set_owner_implementation(Thread *new_owner) {
+       //   already hold Terminator_lock - may happen because of periodic safepoints
+       if (this->rank() != Mutex::native &&
+           this->rank() != Mutex::suspend_resume &&
++          this->rank() != Mutex::redefine_classes && 
+           locks != NULL && locks->rank() <= this->rank() &&
+           !SafepointSynchronize::is_at_safepoint() &&
+           this != Interrupt_lock &&
+diff --git a/src/share/vm/runtime/mutex.hpp b/src/share/vm/runtime/mutex.hpp
+index 7d2cd82..11eb32e 100644
+--- a/src/share/vm/runtime/mutex.hpp
++++ b/src/share/vm/runtime/mutex.hpp
+@@ -109,7 +109,8 @@ class Monitor : public CHeapObj<mtInternal> {
+        barrier     = safepoint      +   1,
+        nonleaf     = barrier        +   1,
+        max_nonleaf = nonleaf        + 900,
+-       native      = max_nonleaf    +   1
++       native      = max_nonleaf    +   1,
++       redefine_classes = native    +   1
+   };
+ 
+   // The WaitSet and EntryList linked lists are composed of ParkEvents.
+diff --git a/src/share/vm/runtime/mutexLocker.cpp b/src/share/vm/runtime/mutexLocker.cpp
+index 77fddef..9d453d4 100644
+--- a/src/share/vm/runtime/mutexLocker.cpp
++++ b/src/share/vm/runtime/mutexLocker.cpp
+@@ -49,6 +49,7 @@
+ // Consider using GCC's __read_mostly.
+ 
+ Mutex*   Patching_lock                = NULL;
++Mutex*   RedefineClasses_lock         = NULL;
+ Monitor* SystemDictionary_lock        = NULL;
+ Mutex*   PackageTable_lock            = NULL;
+ Mutex*   CompiledIC_lock              = NULL;
+@@ -91,6 +92,7 @@ Mutex*   Shared_SATB_Q_lock           = NULL;
+ Mutex*   DirtyCardQ_FL_lock           = NULL;
+ Monitor* DirtyCardQ_CBL_mon           = NULL;
+ Mutex*   Shared_DirtyCardQ_lock       = NULL;
++Monitor* RedefinitionSync_lock        = NULL;
+ Mutex*   ParGCRareEvent_lock          = NULL;
+ Mutex*   EvacFailureStack_lock        = NULL;
+ Mutex*   DerivedPointerTableGC_lock   = NULL;
+@@ -208,6 +210,7 @@ void mutex_init() {
+     def(HotCardCache_lock          , Mutex  , special  ,   true );
+     def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true );
+   }
++  def(RedefinitionSync_lock        , Monitor  , leaf     ,   false );
+   def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true );
+   def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true );
+   def(CodeCache_lock               , Mutex  , special,     true );
+@@ -283,6 +286,7 @@ void mutex_init() {
+   def(Debug3_lock                  , Mutex  , nonleaf+4,   true );
+   def(CompileThread_lock           , Monitor, nonleaf+5,   false);
+   def(PeriodicTask_lock            , Monitor, nonleaf+5,   true);
++  def(RedefineClasses_lock         , Mutex  , nonleaf+7,   false ); // for ensuring that class redefinition is not done in parallel
+ 
+ #ifdef INCLUDE_TRACE
+   def(JfrMsg_lock                  , Monitor, leaf,        true);
+diff --git a/src/share/vm/runtime/mutexLocker.hpp b/src/share/vm/runtime/mutexLocker.hpp
+index a6549b1..089ed11 100644
+--- a/src/share/vm/runtime/mutexLocker.hpp
++++ b/src/share/vm/runtime/mutexLocker.hpp
+@@ -43,6 +43,8 @@
+ // Mutexes used in the VM.
+ 
+ extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
++extern Monitor* RedefinitionSync_lock;           // a lock on synchronized class redefinition
++extern Mutex*   RedefineClasses_lock;            // a lock on class redefinition
+ extern Monitor* SystemDictionary_lock;           // a lock on the system dictonary
+ extern Mutex*   PackageTable_lock;               // a lock on the class loader package table
+ extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
+diff --git a/src/share/vm/runtime/reflection.cpp b/src/share/vm/runtime/reflection.cpp
+index 1665d93..6baabba 100644
+--- a/src/share/vm/runtime/reflection.cpp
++++ b/src/share/vm/runtime/reflection.cpp
+@@ -468,7 +468,8 @@ bool Reflection::verify_class_access(klassOop current_class, klassOop new_class,
+   // sun/reflect/MagicAccessorImpl subclasses to succeed trivially.
+   if (   JDK_Version::is_gte_jdk14x_version()
+       && UseNewReflection
+-      && Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass())) {
++      && (Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass()) ||
++      Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass()->klass_part()->newest_version()))) {
+     return true;
+   }
+ 
+@@ -519,6 +520,12 @@ bool Reflection::verify_field_access(klassOop current_class,
+                                      AccessFlags access,
+                                      bool classloader_only,
+                                      bool protected_restriction) {
++
++  // (tw) Decide accessibility based on active version
++  if (current_class != NULL) {
++    current_class = current_class->klass_part()->active_version();
++  }
++  
+   // Verify that current_class can access a field of field_class, where that
+   // field's access bits are "access".  We assume that we've already verified
+   // that current_class can access field_class.
+@@ -560,7 +567,8 @@ bool Reflection::verify_field_access(klassOop current_class,
+   // sun/reflect/MagicAccessorImpl subclasses to succeed trivially.
+   if (   JDK_Version::is_gte_jdk14x_version()
+       && UseNewReflection
+-      && Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass())) {
++      && (Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass()) ||
++      Klass::cast(current_class)->is_subclass_of(SystemDictionary::reflect_MagicAccessorImpl_klass()->klass_part()->newest_version()))) {
+     return true;
+   }
+ 
+diff --git a/src/share/vm/runtime/sharedRuntime.cpp b/src/share/vm/runtime/sharedRuntime.cpp
+index 709d783..e0e19b1 100644
+--- a/src/share/vm/runtime/sharedRuntime.cpp
++++ b/src/share/vm/runtime/sharedRuntime.cpp
+@@ -1137,7 +1137,20 @@ methodHandle SharedRuntime::resolve_helper(JavaThread *thread,
+   if (JvmtiExport::can_hotswap_or_post_breakpoint()) {
+     int retry_count = 0;
+     while (!HAS_PENDING_EXCEPTION && callee_method->is_old() &&
+-           callee_method->method_holder() != SystemDictionary::Object_klass()) {
++           callee_method->method_holder()->klass_part()->newest_version() != SystemDictionary::Object_klass()->klass_part()->newest_version()) {
++
++      // DCEVM: If we are executing an old method, this is OK!
++      {
++        ResourceMark rm(thread);
++        RegisterMap cbl_map(thread, false);
++        frame caller_frame = thread->last_frame().sender(&cbl_map);
++
++        CodeBlob* caller_cb = caller_frame.cb();
++        guarantee(caller_cb != NULL && caller_cb->is_nmethod(), "must be called from nmethod");
++        nmethod* caller_nm = caller_cb->as_nmethod_or_null();
++        if (caller_nm->method()->is_old()) break;
++      }
++
+       // If has a pending exception then there is no need to re-try to
+       // resolve this method.
+       // If the method has been redefined, we need to try again.
+diff --git a/src/share/vm/runtime/thread.cpp b/src/share/vm/runtime/thread.cpp
+index f3acf4d..ea61cae 100644
+--- a/src/share/vm/runtime/thread.cpp
++++ b/src/share/vm/runtime/thread.cpp
+@@ -216,6 +216,8 @@ Thread::Thread() {
+   set_self_raw_id(0);
+   set_lgrp_id(-1);
+ 
++  _redefine_classes_mutex = new Mutex(Mutex::redefine_classes, "redefine classes lock", false);
++
+   // allocated data structures
+   set_osthread(NULL);
+   set_resource_area(new (mtThread)ResourceArea());
+@@ -249,6 +251,7 @@ Thread::Thread() {
+   omFreeProvision = 32 ;
+   omInUseList = NULL ;
+   omInUseCount = 0 ;
++  _pretend_new_universe = false;
+ 
+ #ifdef ASSERT
+   _visited_for_critical_count = false;
+@@ -884,6 +887,15 @@ bool Thread::owns_locks_but_compiled_lock() const {
+   return false;
+ }
+ 
++bool Thread::owns_locks_but_redefine_classes_lock() const {
++  for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
++    if (cur != RedefineClasses_lock && cur->rank() != Mutex::redefine_classes) {
++      return true;
++    }
++  }
++  return false;
++}
++
+ 
+ #endif
+ 
+@@ -1637,7 +1649,7 @@ void JavaThread::run() {
+   ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
+ 
+   assert(JavaThread::current() == this, "sanity check");
+-  assert(!Thread::current()->owns_locks(), "sanity check");
++  assert(!Thread::current()->owns_locks_but_redefine_classes_lock(), "sanity check");
+ 
+   DTRACE_THREAD_PROBE(start, this);
+ 
+@@ -3193,7 +3205,7 @@ static void compiler_thread_entry(JavaThread* thread, TRAPS) {
+ 
+ // Create a CompilerThread
+ CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
+-: JavaThread(&compiler_thread_entry) {
++: JavaThread(&compiler_thread_entry), _should_bailout(false) {
+   _env   = NULL;
+   _log   = NULL;
+   _task  = NULL;
+@@ -3201,6 +3213,7 @@ CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
+   _counters = counters;
+   _buffer_blob = NULL;
+   _scanned_nmethod = NULL;
++  _compilation_mutex = new Mutex(Mutex::redefine_classes, "compilationMutex", false);
+ 
+ #ifndef PRODUCT
+   _ideal_graph_printer = NULL;
+@@ -3230,6 +3243,7 @@ int         Threads::_number_of_threads = 0;
+ int         Threads::_number_of_non_daemon_threads = 0;
+ int         Threads::_return_code = 0;
+ size_t      JavaThread::_stack_size_at_create = 0;
++bool        Threads::_wait_at_instrumentation_entry = false;
+ 
+ // All JavaThreads
+ #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
+diff --git a/src/share/vm/runtime/thread.hpp b/src/share/vm/runtime/thread.hpp
+index 774bd27..4ca4502 100644
+--- a/src/share/vm/runtime/thread.hpp
++++ b/src/share/vm/runtime/thread.hpp
+@@ -203,11 +203,14 @@ class Thread: public ThreadShadow {
+   void enter_signal_handler() { _num_nested_signal++; }
+   void leave_signal_handler() { _num_nested_signal--; }
+   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
++  Mutex* redefine_classes_mutex() { return _redefine_classes_mutex; }
+ 
+  private:
+   // Debug tracing
+   static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
+ 
++  Mutex* _redefine_classes_mutex;
++
+   // Active_handles points to a block of handles
+   JNIHandleBlock* _active_handles;
+ 
+@@ -530,10 +533,15 @@ public:
+   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
+   int              _lgrp_id;
+ 
++
++  bool             _pretend_new_universe;
++
+  public:
+   // Stack overflow support
+   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
+ 
++  void    set_pretend_new_universe(bool b) { if (_pretend_new_universe != b) { if (TraceRedefineClasses >= 5) tty->print_cr("Changing pretend universe to %d", (int)b); _pretend_new_universe = b; } }
++  bool    pretend_new_universe() { return _pretend_new_universe; }
+   void    set_stack_base(address base) { _stack_base = base; }
+   size_t  stack_size() const           { return _stack_size; }
+   void    set_stack_size(size_t size)  { _stack_size = size; }
+@@ -570,6 +578,7 @@ public:
+   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
+   Monitor* owned_locks() const                   { return _owned_locks;          }
+   bool owns_locks() const                        { return owned_locks() != NULL; }
++  bool owns_locks_but_redefine_classes_lock() const;
+   bool owns_locks_but_compiled_lock() const;
+ 
+   // Deadlock detection
+@@ -1793,6 +1802,8 @@ class CompilerThread : public JavaThread {
+   CompileTask*  _task;
+   CompileQueue* _queue;
+   BufferBlob*   _buffer_blob;
++  bool          _should_bailout;
++  Mutex*        _compilation_mutex;
+ 
+   nmethod*      _scanned_nmethod;  // nmethod being scanned by the sweeper
+ 
+@@ -1802,12 +1813,16 @@ class CompilerThread : public JavaThread {
+ 
+   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
+ 
++  bool should_bailout() const                    { return _should_bailout; }
++  void set_should_bailout(bool b)                { _should_bailout = false; }
++
+   bool is_Compiler_thread() const                { return true; }
+   // Hide this compiler thread from external view.
+   bool is_hidden_from_external_view() const      { return true; }
+ 
+   CompileQueue* queue()                          { return _queue; }
+   CompilerCounters* counters()                   { return _counters; }
++  Mutex *compilation_mutex()                      { return _compilation_mutex; }
+ 
+   // Get/set the thread's compilation environment.
+   ciEnv*        env()                            { return _env; }
+@@ -1862,6 +1877,7 @@ class Threads: AllStatic {
+   static int         _number_of_threads;
+   static int         _number_of_non_daemon_threads;
+   static int         _return_code;
++  static bool        _wait_at_instrumentation_entry;
+ 
+  public:
+   // Thread management
+@@ -1873,6 +1889,9 @@ class Threads: AllStatic {
+   static JavaThread* first()                     { return _thread_list; }
+   static void threads_do(ThreadClosure* tc);
+ 
++  static bool wait_at_instrumentation_entry() { return _wait_at_instrumentation_entry; }
++  static void set_wait_at_instrumentation_entry(bool b) { _wait_at_instrumentation_entry = b; }
++
+   // Initializes the vm and creates the vm thread
+   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
+   static void convert_vm_init_libraries_to_agents();
+diff --git a/src/share/vm/runtime/vframe.cpp b/src/share/vm/runtime/vframe.cpp
+index 09e324f..d47ffef 100644
+--- a/src/share/vm/runtime/vframe.cpp
++++ b/src/share/vm/runtime/vframe.cpp
+@@ -253,6 +253,46 @@ methodOop interpretedVFrame::method() const {
+   return fr().interpreter_frame_method();
+ }
+ 
++// (tw) Sets interpreter frame method.
++void interpretedVFrame::set_method(methodOop new_method, int new_bci) {
++  methodOop old_method = fr().interpreter_frame_method();
++  int old_stack_size = fr().interpreter_frame_expression_stack_size();
++  if (old_method == new_method) return;
++  u_char *old_bcp = bcp();
++  int old_bci = bci();
++  fr().interpreter_frame_set_method(new_method);
++  fr().interpreter_frame_set_cache(new_method->constants()->cache());
++  u_char *new_bcp = new_method->code_base() + new_bci;
++  assert(new_method->bcp_from(new_bci) == new_bcp, "");
++
++  set_bcp(new_bcp);
++
++  Bytecodes::Code code = Bytecodes::java_code_at(old_method, old_bcp);
++  assert(Bytecodes::java_code_at(new_method, new_bcp) == code, "must have same bytecode at this position");
++
++  switch (code) {
++    case Bytecodes::_invokevirtual  :
++    case Bytecodes::_invokespecial  :
++    case Bytecodes::_invokestatic   :
++    case Bytecodes::_invokeinterface: {
++      int old_index = Bytes::get_native_u2(old_bcp+1);
++      int new_index = Bytes::get_native_u2(new_bcp+1);
++      new_method->constants()->cache()->entry_at(new_index)->copy_from(old_method->constants()->cache()->entry_at(old_index));
++      break;
++    }
++
++    case Bytecodes::_invokedynamic: {
++      int old_index = Bytes::get_native_u4(old_bcp+1);
++      int new_index = Bytes::get_native_u4(new_bcp+1);
++      new_method->constants()->cache()->secondary_entry_at(new_index)->copy_from(old_method->constants()->cache()->secondary_entry_at(old_index));
++      break;
++    }
++  }
++
++  int new_stack_size = fr().interpreter_frame_expression_stack_size();
++  assert(new_method->validate_bci_from_bcx((intptr_t)new_bcp) == new_bci, "");
++}
++
+ StackValueCollection* interpretedVFrame::locals() const {
+   int length = method()->max_locals();
+ 
+diff --git a/src/share/vm/runtime/vframe.hpp b/src/share/vm/runtime/vframe.hpp
+index badfea5..edbc5c7 100644
+--- a/src/share/vm/runtime/vframe.hpp
++++ b/src/share/vm/runtime/vframe.hpp
+@@ -163,6 +163,7 @@ class interpretedVFrame: public javaVFrame {
+   StackValueCollection*        locals()         const;
+   StackValueCollection*        expressions()    const;
+   GrowableArray<MonitorInfo*>* monitors()       const;
++  void                         set_method(methodOop method, int new_bci);
+ 
+   void set_locals(StackValueCollection* values) const;
+ 
+diff --git a/src/share/vm/runtime/vmThread.cpp b/src/share/vm/runtime/vmThread.cpp
+index 5ddcf26..213e678 100644
+--- a/src/share/vm/runtime/vmThread.cpp
++++ b/src/share/vm/runtime/vmThread.cpp
+@@ -691,6 +691,10 @@ void VMThread::execute(VM_Operation* op) {
+ void VMThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+   Thread::oops_do(f, cf);
+   _vm_queue->oops_do(f);
++  // (DCEVM) need to update oops in VM_RedefineClasses!
++  if (_cur_vm_operation != NULL) {
++    _cur_vm_operation->oops_do(f);
++  }
+ }
+ 
+ //------------------------------------------------------------------------------------------------------------------
+diff --git a/src/share/vm/utilities/exceptions.cpp b/src/share/vm/utilities/exceptions.cpp
+index 03f254d..c9e0efc 100644
+--- a/src/share/vm/utilities/exceptions.cpp
++++ b/src/share/vm/utilities/exceptions.cpp
+@@ -254,6 +254,8 @@ Handle Exceptions::new_exception(Thread *thread, Symbol* name,
+   assert(thread->is_Java_thread(), "can only be called by a Java thread");
+   assert(!thread->has_pending_exception(), "already has exception");
+ 
++  bool old_pretend_value = Thread::current()->pretend_new_universe();
++  Thread::current()->set_pretend_new_universe(false);
+   Handle h_exception;
+ 
+   // Resolve exception klass
+@@ -285,6 +287,7 @@ Handle Exceptions::new_exception(Thread *thread, Symbol* name,
+     h_exception = Handle(thread, thread->pending_exception());
+     thread->clear_pending_exception();
+   }
++  Thread::current()->set_pretend_new_universe(old_pretend_value);
+   return h_exception;
+ }
+ 
+@@ -295,6 +298,8 @@ Handle Exceptions::new_exception(Thread *thread, Symbol* name,
+                                  Symbol* signature, JavaCallArguments *args,
+                                  Handle h_cause,
+                                  Handle h_loader, Handle h_protection_domain) {
++  bool old_pretend_value = Thread::current()->pretend_new_universe();
++  Thread::current()->set_pretend_new_universe(false);
+   Handle h_exception = new_exception(thread, name, signature, args, h_loader, h_protection_domain);
+ 
+   // Future: object initializer should take a cause argument
+@@ -317,6 +322,8 @@ Handle Exceptions::new_exception(Thread *thread, Symbol* name,
+     h_exception = Handle(thread, thread->pending_exception());
+     thread->clear_pending_exception();
+   }
++
++  Thread::current()->set_pretend_new_universe(old_pretend_value);
+   return h_exception;
+ }
+ 
+diff --git a/src/share/vm/utilities/growableArray.hpp b/src/share/vm/utilities/growableArray.hpp
+index ea92a80..05e940e 100644
+--- a/src/share/vm/utilities/growableArray.hpp
++++ b/src/share/vm/utilities/growableArray.hpp
+@@ -145,6 +145,33 @@ class GenericGrowableArray : public ResourceObj {
+     assert(on_stack(), "fast ResourceObj path only");
+     return (void*)resource_allocate_bytes(thread, elementSize * _max);
+   }
++
++};
++
++template<class E, class F> class Pair : public StackObj
++{
++private:
++  E _left;
++  F _right;
++
++public:
++
++  Pair() {
++
++  }
++
++  Pair(E left, F right) {
++    this->_left = left;
++    this->_right = right;
++  }
++
++  E left() {
++    return _left;
++  }
++
++  F right() {
++    return _right;
++  }
+ };
+ 
+ template<class E> class GrowableArray : public GenericGrowableArray {