--- /dev/null
+diff --git a/src/cpu/x86/vm/interp_masm_x86_32.cpp b/src/cpu/x86/vm/interp_masm_x86_32.cpp
+index b0ebcfd..6366d68 100644
+--- a/src/cpu/x86/vm/interp_masm_x86_32.cpp
++++ b/src/cpu/x86/vm/interp_masm_x86_32.cpp
+@@ -1364,7 +1364,7 @@
+ }
+
+ // RedefineClasses() tracing support for obsolete method entry
+- if (RC_TRACE_IN_RANGE(0x00001000, 0x00002000)) {
++ IF_TRACE_RC4 {
+ get_thread(rcx);
+ get_method(rbx);
+ call_VM_leaf(
+diff --git a/src/cpu/x86/vm/interp_masm_x86_64.cpp b/src/cpu/x86/vm/interp_masm_x86_64.cpp
+index 2790c2a..c315b18 100644
+--- a/src/cpu/x86/vm/interp_masm_x86_64.cpp
++++ b/src/cpu/x86/vm/interp_masm_x86_64.cpp
+@@ -1427,7 +1427,7 @@
+ }
+
+ // RedefineClasses() tracing support for obsolete method entry
+- if (RC_TRACE_IN_RANGE(0x00001000, 0x00002000)) {
++ IF_TRACE_RC4 {
+ get_method(c_rarg1);
+ call_VM_leaf(
+ CAST_FROM_FN_PTR(address, SharedRuntime::rc_trace_method_entry),
+diff --git a/src/cpu/x86/vm/sharedRuntime_x86_32.cpp b/src/cpu/x86/vm/sharedRuntime_x86_32.cpp
+index 16958cd..09d6300 100644
+--- a/src/cpu/x86/vm/sharedRuntime_x86_32.cpp
++++ b/src/cpu/x86/vm/sharedRuntime_x86_32.cpp
+@@ -1976,7 +1976,7 @@
+ }
+
+ // RedefineClasses() tracing support for obsolete method entry
+- if (RC_TRACE_IN_RANGE(0x00001000, 0x00002000)) {
++ IF_TRACE_RC4 {
+ __ movoop(rax, JNIHandles::make_local(method()));
+ __ call_VM_leaf(
+ CAST_FROM_FN_PTR(address, SharedRuntime::rc_trace_method_entry),
+diff --git a/src/cpu/x86/vm/sharedRuntime_x86_64.cpp b/src/cpu/x86/vm/sharedRuntime_x86_64.cpp
+index 7dc4e62..86c8c95 100644
+--- a/src/cpu/x86/vm/sharedRuntime_x86_64.cpp
++++ b/src/cpu/x86/vm/sharedRuntime_x86_64.cpp
+@@ -2235,7 +2235,7 @@
+ }
+
+ // RedefineClasses() tracing support for obsolete method entry
+- if (RC_TRACE_IN_RANGE(0x00001000, 0x00002000)) {
++ IF_TRACE_RC4 {
+ // protect the args we've loaded
+ save_args(masm, total_c_args, c_arg, out_regs);
+ __ movoop(c_rarg1, JNIHandles::make_local(method()));
+diff --git a/src/share/vm/c1/c1_Compilation.hpp b/src/share/vm/c1/c1_Compilation.hpp
+index 9a8ca61..83e6f54 100644
+--- a/src/share/vm/c1/c1_Compilation.hpp
++++ b/src/share/vm/c1/c1_Compilation.hpp
+@@ -242,8 +242,9 @@
+ #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; }
++// (tw) Also checks a thread local flag that can be set to trigger compiler bailout from another thread.
++#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/ciObjectFactory.cpp b/src/share/vm/ci/ciObjectFactory.cpp
+index e0ab96b..db8e551 100644
+--- a/src/share/vm/ci/ciObjectFactory.cpp
++++ b/src/share/vm/ci/ciObjectFactory.cpp
+@@ -764,3 +764,26 @@
+ _unloaded_instances->length(),
+ _unloaded_klasses->length());
+ }
++
++int ciObjectFactory::compare_ciobjects(ciObject** a, ciObject** b) {
++ oop oop1 = (*a)->get_oop();
++ oop oop2 = (*b)->get_oop();
++ return ((oop1 > oop2) ? 1 : ((oop1 == oop2) ? 0 : -1));
++}
++
++// (DCEVM) Resoring the ciObject arrays after class redefinition
++void ciObjectFactory::resort_shared_ci_objects() {
++ _shared_ci_objects->sort(ciObjectFactory::compare_ciobjects);
++
++#ifdef ASSERT
++ if (CIObjectFactoryVerify) {
++ oop last = NULL;
++ for (int j = 0; j < _shared_ci_objects->length(); j++) {
++ oop o = _shared_ci_objects->at(j)->get_oop();
++ assert(last < o, "out of order");
++ last = o;
++ }
++ }
++#endif // ASSERT
++}
++
+diff --git a/src/share/vm/ci/ciObjectFactory.hpp b/src/share/vm/ci/ciObjectFactory.hpp
+index 26cc2c3..d99d3d6 100644
+--- a/src/share/vm/ci/ciObjectFactory.hpp
++++ b/src/share/vm/ci/ciObjectFactory.hpp
+@@ -88,6 +88,7 @@
+
+ ciInstance* get_unloaded_instance(ciInstanceKlass* klass);
+
++ static int compare_ciobjects(ciObject** a, ciObject** b);
+ public:
+ static bool is_initialized() { return _initialized; }
+
+@@ -137,6 +138,8 @@
+
+ void print_contents();
+ void print();
++
++ static void resort_shared_ci_objects();
+ };
+
+ #endif // SHARE_VM_CI_CIOBJECTFACTORY_HPP
+diff --git a/src/share/vm/classfile/classFileParser.cpp b/src/share/vm/classfile/classFileParser.cpp
+index 847cbd2..c4bdc54 100644
+--- a/src/share/vm/classfile/classFileParser.cpp
++++ b/src/share/vm/classfile/classFileParser.cpp
+@@ -795,6 +795,7 @@
+ 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 @@
+ 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 @@
+ 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);
+ }
+
+@@ -2955,8 +2962,10 @@
+ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
+ Handle class_loader,
+ Handle protection_domain,
++ KlassHandle old_klass,
+ KlassHandle host_klass,
+ GrowableArray<Handle>* cp_patches,
++ GrowableArray<Symbol*>* parsed_super_symbols,
+ TempNewSymbol& parsed_name,
+ bool verify,
+ TRAPS) {
+@@ -2982,7 +2991,7 @@
+
+ init_parsed_class_attributes();
+
+- if (JvmtiExport::should_post_class_file_load_hook()) {
++ if (parsed_super_symbols == NULL && JvmtiExport::should_post_class_file_load_hook()) {
+ // Get the cached class file bytes (if any) from the class that
+ // is being redefined or retransformed. We use jvmti_thread_state()
+ // instead of JvmtiThreadState::state_for(jt) so we don't allocate
+@@ -3005,10 +3014,13 @@
+ 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.
+@@ -3124,6 +3136,30 @@
+ CHECK_(nullHandle));
+ }
+
++ // (tw) Do not parse full class file, only get super symbols and return.
++ if (parsed_super_symbols != NULL) {
++ u2 super_class_index = cfs->get_u2_fast();
++
++ if (super_class_index != 0) {
++ parsed_super_symbols->append(cp->klass_name_at(super_class_index));
++ }
++
++ // 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_NULL);
++ }
++
++ for (int i=0; i<local_interfaces->length(); i++) {
++ oop o = local_interfaces->obj_at(i);
++ parsed_super_symbols->append(((klassOop)o)->klass_part()->name());
++ }
++ return NULL;
++ }
++
+ klassOop preserve_this_klass; // for storing result across HandleMark
+
+ // release all handles when parsing is done
+@@ -3164,7 +3200,11 @@
+ // 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 +3222,7 @@
+ 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 +3277,9 @@
+ 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 +3668,19 @@
+ rt = REF_NONE;
+ } else {
+ rt = super_klass->reference_type();
++
++ // (tw) 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
+@@ -3634,6 +3689,7 @@
+ total_oop_map_count,
+ access_flags,
+ rt, host_klass,
++ old_klass,
+ CHECK_(nullHandle));
+ instanceKlassHandle this_klass (THREAD, ik);
+
+@@ -3726,7 +3782,7 @@
+ 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));
+@@ -3744,6 +3800,10 @@
+ // check that if this class is an interface then it doesn't have static methods
+ if (this_klass->is_interface()) {
+ check_illegal_static_method(this_klass, CHECK_(nullHandle));
++ }
++
++ if (rt == REF_OTHER) {
++ instanceRefKlass::update_nonstatic_oop_maps(ik);
+ }
+
+ // Allocate mirror and initialize static fields
+@@ -3891,7 +3951,7 @@
+ }
+
+
+-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 +3959,9 @@
+ 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 +3977,7 @@
+
+ // 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..ebf08b3 100644
+--- a/src/share/vm/classfile/classFileParser.hpp
++++ b/src/share/vm/classfile/classFileParser.hpp
+@@ -151,6 +151,7 @@
+ Handle class_loader,
+ Handle protection_domain,
+ Symbol* class_name,
++ KlassHandle old_klass,
+ TRAPS);
+
+ // Field parsing
+@@ -239,7 +240,7 @@
+ 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);
+
+@@ -357,17 +358,20 @@
+ 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, 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,
++ GrowableArray<Symbol*>* parsed_super_symbols,
+ TempNewSymbol& parsed_name,
+ bool verify,
+ TRAPS);
+diff --git a/src/share/vm/classfile/classLoader.cpp b/src/share/vm/classfile/classLoader.cpp
+index aa670a4..584c168 100644
+--- a/src/share/vm/classfile/classLoader.cpp
++++ b/src/share/vm/classfile/classLoader.cpp
+@@ -924,6 +924,7 @@
+ 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..d167c98 100644
+--- a/src/share/vm/classfile/dictionary.cpp
++++ b/src/share/vm/classfile/dictionary.cpp
+@@ -144,87 +144,10 @@
+ probe = *p;
+ klassOop e = probe->klass();
+ oop class_loader = probe->loader();
+-
+ instanceKlass* ik = instanceKlass::cast(e);
+- if (ik->previous_versions() != NULL) {
+- // This klass has previous versions so see what we can cleanup
+- // while it is safe to do so.
+-
+- int gc_count = 0; // leave debugging breadcrumbs
+- int live_count = 0;
+-
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000200, ("unload: %s: previous version length=%d",
+- ik->external_name(), ik->previous_versions()->length()));
+-
+- for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
+- // check the previous versions array for GC'ed weak refs
+- PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
+- jobject cp_ref = pv_node->prev_constant_pool();
+- assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
+- if (cp_ref == NULL) {
+- delete pv_node;
+- ik->previous_versions()->remove_at(i);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue; // robustness
+- }
+-
+- constantPoolOop pvcp = (constantPoolOop)JNIHandles::resolve(cp_ref);
+- if (pvcp == NULL) {
+- // this entry has been GC'ed so remove it
+- delete pv_node;
+- ik->previous_versions()->remove_at(i);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- gc_count++;
+- continue;
+- } else {
+- RC_TRACE(0x00000200, ("unload: previous version @%d is alive", i));
+- if (is_alive->do_object_b(pvcp)) {
+- live_count++;
+- } else {
+- guarantee(false, "sanity check");
+- }
+- }
+-
+- GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
+- if (method_refs != NULL) {
+- RC_TRACE(0x00000200, ("unload: previous methods length=%d",
+- method_refs->length()));
+- for (int j = method_refs->length() - 1; j >= 0; j--) {
+- jweak method_ref = method_refs->at(j);
+- assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
+- if (method_ref == NULL) {
+- method_refs->remove_at(j);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue; // robustness
+- }
+-
+- methodOop method = (methodOop)JNIHandles::resolve(method_ref);
+- if (method == NULL) {
+- // this method entry has been GC'ed so remove it
+- JNIHandles::destroy_weak_global(method_ref);
+- method_refs->remove_at(j);
+- } else {
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000200,
+- ("unload: %s(%s): prev method @%d in version @%d is alive",
+- method->name()->as_C_string(),
+- method->signature()->as_C_string(), j, i));
+- }
+- }
+- }
+- }
+- assert(ik->previous_versions()->length() == live_count, "sanity check");
+- RC_TRACE(0x00000200,
+- ("unload: previous version stats: live=%d, GC'ed=%d", live_count,
+- gc_count));
+- }
+-
++
+ // Non-unloadable classes were handled in always_strong_oops_do
+- if (!is_strongly_reachable(class_loader, e)) {
++ if (!ik->is_redefining() && !is_strongly_reachable(class_loader, e)) {
+ // Entry was not visited in phase1 (negated test from phase1)
+ assert(class_loader != NULL, "unloading entry with null class loader");
+ oop k_def_class_loader = ik->class_loader();
+@@ -325,6 +248,7 @@
+ }
+ }
+ }
++
+
+ // Added for initialize_itable_for_klass to handle exceptions
+ // Just the classes from defining class loaders
+@@ -433,6 +357,33 @@
+ add_entry(index, entry);
+ }
+
++// (tw) 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;
++}
++
++// (tw) 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 +410,21 @@
+ return NULL;
+ }
+
++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 +437,7 @@
+ 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 +449,7 @@
+ 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..ea1fe3c 100644
+--- a/src/share/vm/classfile/dictionary.hpp
++++ b/src/share/vm/classfile/dictionary.hpp
+@@ -73,6 +73,10 @@
+
+ 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);
+
+@@ -105,6 +109,7 @@
+ 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 78176f1..3903424 100644
+--- a/src/share/vm/classfile/javaClasses.cpp
++++ b/src/share/vm/classfile/javaClasses.cpp
+@@ -637,6 +637,10 @@
+ assert(java_lang_Class::is_instance(java_class), "must be a Class object");
+ klassOop k = klassOop(java_class->obj_field(_klass_offset));
+ assert(k == NULL || k->is_klass(), "type check");
++ // Necessary to make old verifier work.
++ if (Thread::current()->pretend_new_universe()) {
++ k = k->klass_part()->newest_version();
++ }
+ return k;
+ }
+
+@@ -1563,6 +1567,7 @@
+ skip_throwableInit_check = true;
+ }
+ }
++ method = method->newest_version();
+ if (method->is_hidden()) {
+ if (skip_hidden) continue;
+ }
+@@ -2558,12 +2563,12 @@
+ 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",
++ TRACE_RC1(("adjust: name=%s",
+ instanceKlass::cast(old_method->method_holder())->external_name()));
+ *trace_name_printed = true;
+ }
+ // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00400000, ("MemberName method update: %s(%s)",
++ TRACE_RC1(("MemberName method update: %s(%s)",
+ new_method->name()->as_C_string(),
+ new_method->signature()->as_C_string()));
+ }
+diff --git a/src/share/vm/classfile/javaClasses.hpp b/src/share/vm/classfile/javaClasses.hpp
+index 7f02ca2..7c4e906 100644
+--- a/src/share/vm/classfile/javaClasses.hpp
++++ b/src/share/vm/classfile/javaClasses.hpp
+@@ -214,6 +214,7 @@
+
+ class java_lang_Class : AllStatic {
+ friend class VMStructs;
++ friend class VM_RedefineClasses;
+
+ private:
+ // The fake offsets are added by the class loader when java.lang.Class is loaded
+@@ -256,7 +257,7 @@
+ static void print_signature(oop java_class, outputStream *st);
+ // Testing
+ static bool is_instance(oop obj) {
+- return obj != NULL && obj->klass() == SystemDictionary::Class_klass();
++ return obj != NULL && (obj->klass()->klass_part()->newest_version() == SystemDictionary::Class_klass()->klass_part()->newest_version());
+ }
+ static bool is_primitive(oop java_class);
+ static BasicType primitive_type(oop java_class);
+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 @@
+ 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/systemDictionary.cpp b/src/share/vm/classfile/systemDictionary.cpp
+index 7901263..ee383b7 100644
+--- a/src/share/vm/classfile/systemDictionary.cpp
++++ b/src/share/vm/classfile/systemDictionary.cpp
+@@ -157,6 +157,7 @@
+ // 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 +200,7 @@
+ // 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(),
++ 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()));
+@@ -961,8 +962,10 @@
+ instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
+ class_loader,
+ protection_domain,
++ KlassHandle(),
+ host_klass,
+ cp_patches,
++ NULL,
+ parsed_name,
+ true,
+ THREAD);
+@@ -1022,7 +1025,15 @@
+ 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 +1061,14 @@
+ 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 &&
+@@ -1087,11 +1103,16 @@
+ // 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
+@@ -1122,7 +1143,7 @@
+ 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 +1370,11 @@
+ }
+ }
+
+-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 +1401,23 @@
+ 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);
++
++ // (tw) 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 +1443,9 @@
+ }
+ 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 +1518,7 @@
+ }
+ }
+
+- define_instance_class(k, THREAD);
++ define_instance_class(k, KlassHandle(), THREAD);
+
+ Handle linkage_exception = Handle(); // null handle
+
+@@ -1613,6 +1649,14 @@
+ 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 (tw): Remove from interfaces.
++}
+
+ // ----------------------------------------------------------------------------
+ // GC support
+@@ -1870,9 +1914,12 @@
+
+ // 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(Cleaner_klass), scan, CHECK);
++ // TODO(tw): Check that the following is also not necessary?
+ instanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
+ instanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
+ instanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
+@@ -1957,7 +2004,7 @@
+ // 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)) {
+ linkage_error = "loader (instance of %s): attempted duplicate class "
+ "definition for name: \"%s\"";
+ } else {
+@@ -2633,8 +2680,10 @@
+ name = find_placeholder(class_name, class_loader);
+ }
+ }
+- guarantee(probe != NULL || name != NULL,
+- "Loaded klasses should be in SystemDictionary");
++ // (tw) Relaxed assertion to allow different class versions. Also allow redefining classes lie around (because of rollback).
++ guarantee(probe != NULL &&
++ (!probe->is_klass() || (!((klassOop)(obj()))->klass_part()->is_redefining()) || ((klassOop)probe)->klass_part()->is_same_or_older_version((klassOop)(obj()))) || ((klassOop)(obj()))->klass_part()->is_redefining(),
++ "Loaded klasses should be in SystemDictionary");
+ }
+
+ // utility function for posting class load event
+diff --git a/src/share/vm/classfile/systemDictionary.hpp b/src/share/vm/classfile/systemDictionary.hpp
+index 85474c5..570606f 100644
+--- a/src/share/vm/classfile/systemDictionary.hpp
++++ b/src/share/vm/classfile/systemDictionary.hpp
+@@ -270,7 +270,7 @@
+ // 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);
+@@ -345,6 +345,8 @@
+ // System loader lock
+ static oop system_loader_lock() { return _system_loader_lock_obj; }
+
++ // Remove link to hierarchy
++ static void remove_from_hierarchy(instanceKlassHandle k);
+ private:
+ // Traverses preloaded oops: various system classes. These are
+ // guaranteed to be in the perm gen.
+@@ -416,6 +418,8 @@
+ int limit = (int)end_id + 1;
+ initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
+ }
++
++ static void rollback_redefinition();
+
+ public:
+ #define WK_KLASS_DECLARE(name, symbol, option) \
+@@ -598,7 +602,7 @@
+ // 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);
+diff --git a/src/share/vm/classfile/verifier.cpp b/src/share/vm/classfile/verifier.cpp
+index 49c4b2c..937f4f6 100644
+--- a/src/share/vm/classfile/verifier.cpp
++++ b/src/share/vm/classfile/verifier.cpp
+@@ -106,7 +106,7 @@
+ 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);
+
+@@ -117,6 +117,7 @@
+
+ const char* klassName = klass->external_name();
+ bool can_failover = FailOverToOldVerifier &&
++ may_use_old_verifier &&
+ klass->major_version() < NOFAILOVER_MAJOR_VERSION;
+
+ // If the class should be verified, first see if we can use the split
+@@ -138,6 +139,7 @@
+ 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 @@
+ exception_message = split_verifier.exception_message();
+ }
+ } else {
++ assert(may_use_old_verifier, "");
+ exception_name = inference_verify(
+ klass, message_buffer, message_buffer_len, THREAD);
+ }
+@@ -210,7 +213,7 @@
+ // 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 +520,7 @@
+
+ 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 +550,7 @@
+ _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++) {
+@@ -2668,7 +2671,8 @@
+ 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 92c4fd2..5e8e0da 100644
+--- a/src/share/vm/classfile/verifier.hpp
++++ b/src/share/vm/classfile/verifier.hpp
+@@ -48,7 +48,7 @@
+ * 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
+@@ -257,7 +257,10 @@
+
+ ErrorContext _error_context; // contains information about an error
+
++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);
+@@ -341,6 +344,7 @@
+
+ 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/code/nmethod.cpp b/src/share/vm/code/nmethod.cpp
+index dddbea2..d5918cd 100644
+--- a/src/share/vm/code/nmethod.cpp
++++ b/src/share/vm/code/nmethod.cpp
+@@ -2083,15 +2083,14 @@
+ methodOop method = deps.method_argument(0);
+ for (int j = 0; j < dependee_methods->length(); j++) {
+ if ((methodOop) dependee_methods->obj_at(j) == method) {
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x01000000,
+- ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
++ ResourceMark rm(Thread::current());
++ TRACE_RC3("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
+ _method->method_holder()->klass_part()->external_name(),
+ _method->name()->as_C_string(),
+ _method->signature()->as_C_string(), compile_id(),
+ method->method_holder()->klass_part()->external_name(),
+ method->name()->as_C_string(),
+- method->signature()->as_C_string()));
++ method->signature()->as_C_string());
+ if (TraceDependencies || LogCompilation)
+ deps.log_dependency(dependee);
+ return true;
+diff --git a/src/share/vm/compiler/compileBroker.cpp b/src/share/vm/compiler/compileBroker.cpp
+index c07d997..3d40411 100644
+--- a/src/share/vm/compiler/compileBroker.cpp
++++ b/src/share/vm/compiler/compileBroker.cpp
+@@ -1592,6 +1592,9 @@
+
+ // Never compile a method if breakpoints are present in it
+ if (method()->number_of_breakpoints() == 0) {
++ // (tw) Obtain a compilation lock. Class redefinition requires that there is no compilation in parallel.
++ thread->compilation_mutex()->lock();
++ thread->set_should_bailout(false);
+ // Compile the method.
+ if ((UseCompiler || AlwaysCompileLoopMethods) && CompileBroker::should_compile_new_jobs()) {
+ invoke_compiler_on_method(task);
+@@ -1599,6 +1602,7 @@
+ // After compilation is disabled, remove remaining methods from queue
+ method->clear_queued_for_compilation();
+ }
++ thread->compilation_mutex()->unlock();
+ }
+ }
+ }
+@@ -1764,7 +1768,11 @@
+ //assert(false, "compiler should always document failure");
+ // The compiler elected, without comment, not to register a result.
+ // Do not attempt further compilations of this method.
+- ci_env.record_method_not_compilable("compile failed", !TieredCompilation);
++ if (((CompilerThread *)Thread::current())->should_bailout()) {
++ ci_env.record_failure("compile externally aborted");
++ } else {
++ ci_env.record_method_not_compilable("compile failed");
++ }
+ }
+
+ // Copy this bit to the enclosing block:
+diff --git a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
+index a3abd66..fb52e6f 100644
+--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
++++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
+@@ -162,6 +162,13 @@
+ }
+ }
+
++
++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.
+@@ -2118,7 +2125,7 @@
+ // Support for compaction
+
+ void CompactibleFreeListSpace::prepare_for_compaction(CompactPoint* cp) {
+- SCAN_AND_FORWARD(cp,end,block_is_obj,block_size);
++ SCAN_AND_FORWARD(cp,end,block_is_obj,block_size,false);
+ // prepare_for_compaction() uses the space between live objects
+ // so that later phase can skip dead space quickly. So verification
+ // of the free lists doesn't work after.
+@@ -2139,7 +2146,7 @@
+ }
+
+ void CompactibleFreeListSpace::compact() {
+- SCAN_AND_COMPACT(obj_size);
++ SCAN_AND_COMPACT(obj_size, false);
+ }
+
+ // fragmentation_metric = 1 - [sum of (fbs**2) / (sum of fbs)**2]
+diff --git a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
+index 24509b6..6670b73 100644
+--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
++++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp
+@@ -149,6 +149,7 @@
+
+ // 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..d1386c7 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 +359,97 @@
+ }
+
+ #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();
++
++ assert(rescued_obj->blueprint()->new_version() != NULL, "just checking");
++
++ if (rescued_obj->blueprint()->new_version()->klass_part()->update_information() != NULL) {
++ MarkSweep::update_fields(rescued_obj, new_obj);
++ } else {
++ rescued_obj->set_klass_no_check(rescued_obj->blueprint()->new_version());
++ 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;
++
++ // Save object somewhere, there is an overlap in fields
++ 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);
++ }
++ }
++
++ tmp_obj->set_klass_no_check(new_klass_oop);
++ int *cur = new_klass_oop->klass_part()->update_information();
++ assert(cur != NULL, "just checking");
++ MarkSweep::update_fields(new_location, tmp_obj, cur);
++
++ if (tmp_obj != q) {
++ FREE_RESOURCE_ARRAY(HeapWord, tmp_obj, size);
++ }
++}
++
++void MarkSweep::update_fields(oop new_location, oop tmp_obj, int *cur) {
++ assert(cur != NULL, "just checking");
++ char* to = (char*)new_location;
++ while (*cur != 0) {
++ int size = *cur;
++ if (size > 0) {
++ cur++;
++ int offset = *cur;
++ HeapWord* from = (HeapWord*)(((char *)tmp_obj) + offset);
++ if (size == HeapWordSize) {
++ *((HeapWord*)to) = *from;
++ } else if (size == HeapWordSize * 2) {
++ *((HeapWord*)to) = *from;
++ *(((HeapWord*)to) + 1) = *(from + 1);
++ } else {
++ Copy::conjoint_jbytes(from, to, size);
++ }
++ to += size;
++ cur++;
++ } else {
++ assert(size < 0, "");
++ int skip = -*cur;
++ Copy::fill_to_bytes(to, skip, 0);
++ to += skip;
++ cur++;
++ }
++ }
++}
+diff --git a/src/share/vm/gc_implementation/shared/markSweep.hpp b/src/share/vm/gc_implementation/shared/markSweep.hpp
+index eb8252c..40118db 100644
+--- a/src/share/vm/gc_implementation/shared/markSweep.hpp
++++ b/src/share/vm/gc_implementation/shared/markSweep.hpp
+@@ -117,7 +117,11 @@
+ 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 +212,9 @@
+ 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 update_fields(oop new_location, oop tmp_obj, int *cur);
+ 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..e6b4166 100644
+--- a/src/share/vm/interpreter/interpreterRuntime.cpp
++++ b/src/share/vm/interpreter/interpreterRuntime.cpp
+@@ -402,7 +402,7 @@
+ 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();
+ }
+diff --git a/src/share/vm/interpreter/linkResolver.cpp b/src/share/vm/interpreter/linkResolver.cpp
+index 1676add..ec32845 100644
+--- a/src/share/vm/interpreter/linkResolver.cpp
++++ b/src/share/vm/interpreter/linkResolver.cpp
+@@ -153,8 +153,8 @@
+ // 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 @@
+ // 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?");
+@@ -643,7 +643,7 @@
+ }
+
+ // 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 +848,7 @@
+ 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 +878,7 @@
+ KlassHandle resolved_klass,
+ Handle recv,
+ KlassHandle recv_klass,
++ KlassHandle current_klass,
+ bool check_null_and_abstract,
+ TRAPS) {
+
+@@ -926,6 +927,9 @@
+ // 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();
++
++ // (tw) Check that the receiver is a subtype of the holder of the resolved method.
++ assert(inst->is_subtype_of(resolved_method->method_holder()), "receiver and resolved method holder are inconsistent");
+ selected_method = methodHandle(THREAD, inst->method_at_vtable(vtable_index));
+ }
+ }
+diff --git a/src/share/vm/interpreter/linkResolver.hpp b/src/share/vm/interpreter/linkResolver.hpp
+index dfd74f9..6ca1b54 100644
+--- a/src/share/vm/interpreter/linkResolver.hpp
++++ b/src/share/vm/interpreter/linkResolver.hpp
+@@ -110,7 +110,8 @@
+ // 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_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 +134,7 @@
+ 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/oopMapCache.cpp b/src/share/vm/interpreter/oopMapCache.cpp
+index 01d5753..6816b3a 100644
+--- a/src/share/vm/interpreter/oopMapCache.cpp
++++ b/src/share/vm/interpreter/oopMapCache.cpp
+@@ -536,9 +536,9 @@
+ if (!_array[i].is_empty() && _array[i].method()->is_old()) {
+ // Cache entry is occupied by an old redefined method and we don't want
+ // to pin it down so flush the entry.
+- RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d",
++ TRACE_RC3("flush: %s(%s): cached entry @%d",
+ _array[i].method()->name()->as_C_string(),
+- _array[i].method()->signature()->as_C_string(), i));
++ _array[i].method()->signature()->as_C_string(), i);
+
+ _array[i].flush();
+ }
+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 @@
+ // 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 @@
+
+ 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/iterator.hpp b/src/share/vm/memory/iterator.hpp
+index b5f8e0e..856cfce 100644
+--- a/src/share/vm/memory/iterator.hpp
++++ b/src/share/vm/memory/iterator.hpp
+@@ -101,6 +101,12 @@
+ #endif
+ };
+
++class OopClosureNoHeader : public OopClosure {
++public:
++ // If "true", invoke on header klass field.
++ bool do_header() { return false; } // Note that this is non-virtual.
++};
++
+ // ObjectClosure is used for iterating through an object space
+
+ class ObjectClosure : public Closure {
+diff --git a/src/share/vm/memory/oopFactory.cpp b/src/share/vm/memory/oopFactory.cpp
+index def88cc..016d7eb 100644
+--- a/src/share/vm/memory/oopFactory.cpp
++++ b/src/share/vm/memory/oopFactory.cpp
+@@ -129,11 +129,11 @@
+ unsigned int nonstatic_oop_map_count,
+ AccessFlags access_flags,
+ ReferenceType rt,
+- KlassHandle host_klass, TRAPS) {
++ KlassHandle host_klass, KlassHandle old_klass, TRAPS) {
+ instanceKlassKlass* ikk = instanceKlassKlass::cast(Universe::instanceKlassKlassObj());
+ return ikk->allocate_instance_klass(name, vtable_len, itable_len,
+ static_field_size, nonstatic_oop_map_count,
+- access_flags, rt, host_klass, CHECK_NULL);
++ access_flags, rt, host_klass, old_klass, CHECK_NULL);
+ }
+
+
+diff --git a/src/share/vm/memory/oopFactory.hpp b/src/share/vm/memory/oopFactory.hpp
+index e7e22d4..ce39ada 100644
+--- a/src/share/vm/memory/oopFactory.hpp
++++ b/src/share/vm/memory/oopFactory.hpp
+@@ -80,7 +80,7 @@
+ unsigned int nonstatic_oop_map_count,
+ AccessFlags access_flags,
+ ReferenceType rt,
+- KlassHandle host_klass, TRAPS);
++ KlassHandle host_klass, KlassHandle old_klass, TRAPS);
+
+ // Methods
+ private:
+diff --git a/src/share/vm/memory/space.cpp b/src/share/vm/memory/space.cpp
+index f97bc34..c8563b2 100644
+--- a/src/share/vm/memory/space.cpp
++++ b/src/share/vm/memory/space.cpp
+@@ -378,9 +378,8 @@
+ _compaction_top = bottom();
+ }
+
+-HeapWord* CompactibleSpace::forward(oop q, size_t size,
+- CompactPoint* cp, HeapWord* compact_top) {
+- // q is alive
++// (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);
+@@ -400,8 +399,15 @@
+ 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) {
++ compact_top = forward_compact_top(size, cp, compact_top);
++
+ // 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 {
+@@ -423,6 +429,58 @@
+ return compact_top;
+ }
+
++// Compute the forward sizes and leave out objects whose position could
++// possibly overlap other objects.
++HeapWord* CompactibleSpace::forward_with_rescue(oop q, size_t size,
++ CompactPoint* cp, HeapWord* compact_top) {
++ size_t forward_size = size;
++
++ // (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 = forward_compact_top(forward_size, cp, compact_top);
++
++ if (must_rescue(oop(q), oop(compact_top))) {
++ if (MarkSweep::_rescued_oops == NULL) {
++ MarkSweep::_rescued_oops = new GrowableArray<oop>(128);
++ }
++ MarkSweep::_rescued_oops->append(oop(q));
++ return compact_top;
++ }
++
++ return forward(q, forward_size, cp, compact_top);
++}
++
++// Compute the forwarding addresses for the objects that need to be rescued.
++HeapWord* CompactibleSpace::forward_rescued(CompactPoint* cp, HeapWord* compact_top) {
++ // TODO: empty the _rescued_oops after ALL spaces are compacted!
++ if (MarkSweep::_rescued_oops != NULL) {
++ 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);
++
++ // (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");
++ size = new_size;
++ }
++
++ compact_top = cp->space->forward(oop(q), size, cp, compact_top);
++ assert(compact_top <= end(), "must not write over end of space!");
++ }
++ MarkSweep::_rescued_oops->clear();
++ MarkSweep::_rescued_oops = NULL;
++ }
++ return compact_top;
++}
+
+ bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words,
+ HeapWord* q, size_t deadlength) {
+@@ -444,12 +502,17 @@
+ #define adjust_obj_size(s) s
+
+ void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) {
+- SCAN_AND_FORWARD(cp, end, block_is_obj, block_size);
++ SCAN_AND_FORWARD(cp, end, block_is_obj, block_size, false);
+ }
+
+ // 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, false);
++ } else {
++ // Redefinition run
++ SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size, true);
++ }
+ }
+
+ void Space::adjust_pointers() {
+@@ -490,6 +553,111 @@
+ 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) {
++ // Only redefined objects can have the need to be rescued.
++ if (oop(old_obj)->blueprint()->new_version() == NULL) return false;
++
++ if (old_obj->is_perm()) {
++ // This object is in perm gen: Always rescue to satisfy invariant obj->klass() <= obj.
++ return true;
++ }
++
++ int new_size = old_obj->size_given_klass(oop(old_obj)->blueprint()->new_version()->klass_part());
++ int original_size = old_obj->size();
++
++ Generation* tenured_gen = GenCollectedHeap::heap()->get_gen(1);
++ bool old_in_tenured = tenured_gen->is_in_reserved(old_obj);
++ bool new_in_tenured = tenured_gen->is_in_reserved(new_obj);
++ if (old_in_tenured == new_in_tenured) {
++ // Rescue if object may overlap with a higher memory address.
++ bool overlap = (old_obj + original_size < new_obj + new_size);
++ if (old_in_tenured) {
++ // 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");
++ } 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(overlap == (space_index(old_obj) < space_index(new_obj)), "slow and fast computation must yield same result");
++ }
++ return overlap;
++
++ } else {
++ assert(space_index(old_obj) != space_index(new_obj), "old_obj and new_obj must be in different spaces");
++ 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;
++ }
++ }
++}
++
++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) {
+@@ -500,7 +668,13 @@
+ }
+
+ void CompactibleSpace::compact() {
+- SCAN_AND_COMPACT(obj_size);
++
++ if(!Universe::is_redefining_gc_run()) {
++ SCAN_AND_COMPACT(obj_size, false);
++ } else {
++ // Redefinition run
++ SCAN_AND_COMPACT(obj_size, true)
++ }
+ }
+
+ 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..ff95a8b 100644
+--- a/src/share/vm/memory/space.hpp
++++ b/src/share/vm/memory/space.hpp
+@@ -445,6 +445,9 @@
+ // 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();
+@@ -474,6 +477,15 @@
+ // accordingly".
+ virtual HeapWord* forward(oop q, size_t size, CompactPoint* cp,
+ HeapWord* compact_top);
++ // (DCEVM) same as forwad, but can rescue objects. Invoked only during
++ // redefinition runs
++ HeapWord* forward_with_rescue(oop q, size_t size, CompactPoint* cp,
++ HeapWord* compact_top);
++
++ HeapWord* forward_rescued(CompactPoint* cp, HeapWord* compact_top);
++
++ // (tw) Compute new compact top without actually forwarding the object.
++ 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; }
+@@ -504,7 +516,7 @@
+ size_t word_len);
+ };
+
+-#define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \
++#define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size,redefinition_run) { \
+ /* Compute the new addresses for the live objects and store it in the mark \
+ * Used by universe::mark_sweep_phase2() \
+ */ \
+@@ -564,7 +576,17 @@
+ Prefetch::write(q, interval); \
+ /* size_t size = oop(q)->size(); changing this for cms for perm gen */\
+ size_t size = block_size(q); \
+- compact_top = cp->space->forward(oop(q), size, cp, compact_top); \
++ if (redefinition_run) { \
++ compact_top = cp->space->forward_with_rescue(oop(q), size, \
++ cp, compact_top); \
++ if (q < first_dead && oop(q)->is_gc_marked()) { \
++ /* Was moved (otherwise, forward would reset mark), \
++ set first_dead to here */ \
++ first_dead = q; \
++ } \
++ } else { \
++ compact_top = cp->space->forward(oop(q), size, cp, compact_top); \
++ } \
+ q += size; \
+ end_of_live = q; \
+ } else { \
+@@ -612,6 +634,8 @@
+ q = end; \
+ } \
+ } \
++ \
++ if (redefinition_run) { compact_top = forward_rescued(cp, compact_top); } \
+ \
+ assert(q == t, "just checking"); \
+ if (liveRange != NULL) { \
+@@ -665,13 +689,8 @@
+ q += size; \
+ } \
+ \
+- if (_first_dead == t) { \
+- q = t; \
+- } else { \
+- /* $$$ This is funky. Using this to read the previously written \
+- * LiveRange. See also use below. */ \
+- q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \
+- } \
++ /* (DCEVM) first_dead can be live object if we move/rescue resized objects */ \
++ q = _first_dead; \
+ } \
+ \
+ const intx interval = PrefetchScanIntervalInBytes; \
+@@ -702,7 +721,7 @@
+ assert(q == t, "just checking"); \
+ }
+
+-#define SCAN_AND_COMPACT(obj_size) { \
++#define SCAN_AND_COMPACT(obj_size, redefinition_run) { \
+ /* Copy all live objects to their new location \
+ * Used by MarkSweep::mark_sweep_phase4() */ \
+ \
+@@ -728,12 +747,8 @@
+ } \
+ ) /* debug_only */ \
+ \
+- if (_first_dead == t) { \
+- q = t; \
+- } else { \
+- /* $$$ Funky */ \
+- q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \
+- } \
++ /* (DCEVM) first_dead can be live object if we move/rescue resized objects */ \
++ q = _first_dead; \
+ } \
+ \
+ const intx scan_interval = PrefetchScanIntervalInBytes; \
+@@ -752,13 +767,36 @@
+ size_t size = obj_size(q); \
+ HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \
+ \
++ if (redefinition_run && must_rescue(oop(q), oop(q)->forwardee())) { \
++ oop dest_obj = rescue(oop(q)); \
++ debug_only(Copy::fill_to_words(q, size, 0)); \
++ q += size; \
++ continue; \
++ } \
++ \
+ /* 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, "everything in this pass should be moving"); \
++ assert(q != compaction_top || oop(q)->blueprint()->new_version() != NULL, \
++ "everything in this pass should be moving"); \
++ if (redefinition_run && oop(q)->blueprint()->new_version() != NULL) { \
++ klassOop new_version = oop(q)->blueprint()->new_version(); \
++ if (new_version->klass_part()->update_information() == NULL) { \
++ Copy::aligned_conjoint_words(q, compaction_top, size); \
++ oop(compaction_top)->set_klass_no_check(new_version); \
++ } else { \
++ MarkSweep::update_fields(oop(q), oop(compaction_top)); \
++ } \
++ oop(compaction_top)->init_mark(); \
++ assert(oop(compaction_top)->klass() != NULL, "should have a class"); \
++ \
++ debug_only(prev_q = q); \
++ q += size; \
++ continue; \
++ } \
+ Copy::aligned_conjoint_words(q, compaction_top, size); \
+ oop(compaction_top)->init_mark(); \
+ assert(oop(compaction_top)->klass() != NULL, "should have a class"); \
+diff --git a/src/share/vm/memory/specialized_oop_closures.hpp b/src/share/vm/memory/specialized_oop_closures.hpp
+index 4d7c50b..671787e 100644
+--- a/src/share/vm/memory/specialized_oop_closures.hpp
++++ b/src/share/vm/memory/specialized_oop_closures.hpp
+@@ -37,6 +37,7 @@
+
+ // Forward declarations.
+ class OopClosure;
++class OopClosureNoHeader;
+ class OopsInGenClosure;
+ // DefNew
+ class ScanClosure;
+@@ -74,6 +75,7 @@
+ #endif
+
+ #define SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_S(f) \
++ f(OopClosureNoHeader,_v) \
+ f(ScanClosure,_nv) \
+ f(FastScanClosure,_nv) \
+ f(FilteringClosure,_nv)
+@@ -132,6 +134,7 @@
+
+ #define ALL_PAR_OOP_ITERATE_CLOSURES(f) \
+ f(OopClosure,_v) \
++ f(OopClosureNoHeader,_v) \
+ SPECIALIZED_PAR_OOP_ITERATE_CLOSURES(f)
+ #endif // SERIALGC
+
+diff --git a/src/share/vm/memory/universe.cpp b/src/share/vm/memory/universe.cpp
+index 4030d9d..052fb27 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;
+@@ -202,6 +204,42 @@
+ f(instanceKlassKlassObj());
+ f(constantPoolKlassObj());
+ f(systemObjArrayKlassObj());
++}
++
++// (tw) 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;
++
++ Universe::oops_do(oopClosure);
++// ReferenceProcessor::oops_do(oopClosure); (tw) check why no longer there
++ JNIHandles::oops_do(oopClosure); // Global (strong) JNI handles
++ Threads::oops_do(oopClosure, NULL);
++ ObjectSynchronizer::oops_do(oopClosure);
++ FlatProfiler::oops_do(oopClosure);
++ JvmtiExport::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);
++
++ // (tw) TODO: Check if this is correct?
++ //CodeCache::scavenge_root_nmethods_oops_do(oopClosure);
++ //Management::oops_do(oopClosure);
++ //ref_processor()->weak_oops_do(&oopClosure);
++ //PSScavenge::reference_processor()->weak_oops_do(&oopClosure);
++
++ // SO_AllClasses
++ SystemDictionary::oops_do(oopClosure);
+ }
+
+ void Universe::oops_do(OopClosure* f, bool do_all) {
+@@ -1599,10 +1637,9 @@
+ }
+
+ // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000100,
+- ("add: %s(%s): adding prev version ref for cached method @%d",
++ TRACE_RC2("add: %s(%s): adding prev version ref for cached method @%d",
+ method->name()->as_C_string(), method->signature()->as_C_string(),
+- _prev_methods->length()));
++ _prev_methods->length());
+
+ methodHandle method_h(method);
+ jweak method_ref = JNIHandles::make_weak_global(method_h);
+@@ -1629,9 +1666,8 @@
+ JNIHandles::destroy_weak_global(method_ref);
+ _prev_methods->remove_at(i);
+ } else {
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
+- m->name()->as_C_string(), m->signature()->as_C_string(), i));
++ TRACE_RC2("add: %s(%s): previous cached method @%d is alive",
++ m->name()->as_C_string(), m->signature()->as_C_string(), i);
+ }
+ }
+ } // end add_previous_version()
+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 @@
+ 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 @@
+
+ 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 @@
+
+ // 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 @@
+
+ // 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/cpCacheOop.cpp b/src/share/vm/oops/cpCacheOop.cpp
+index b8d6f83..79f509c 100644
+--- a/src/share/vm/oops/cpCacheOop.cpp
++++ b/src/share/vm/oops/cpCacheOop.cpp
+@@ -40,6 +40,11 @@
+ void ConstantPoolCacheEntry::initialize_entry(int index) {
+ assert(0 < index && index < 0x10000, "sanity check");
+ _indices = index;
++// (DCEVM) Should put something else to force JVM to fail if these invalid entries are accessed!
++//#ifdef ASSERT
++ _f1 = NULL;
++ _f2 = 0;
++//#endif
+ assert(constant_pool_index() == index, "");
+ }
+
+@@ -162,7 +167,8 @@
+ 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;
+@@ -516,118 +522,6 @@
+ }
+ #endif // SERIALGC
+
+-// RedefineClasses() API support:
+-// 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) {
+-
+- 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()));
+- }
+-
+- return true;
+- }
+-
+- // f1() is not used with virtual entries so bail out
+- 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.
+- 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;
+- }
+-
+- 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();
+- }
+-
+- // Secondary entry can have vfinal flag and a NULL _f2, giving m==NULL here:
+- assert(is_secondary_entry() || (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(" -------------");
+@@ -665,60 +559,12 @@
+ }
+ }
+
+-// 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() {
+
+ 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_secondary_entry()) {
++ entry_at(i)->initialize_entry(entry_at(i)->constant_pool_index());
++ }
+ }
+ }
+
+-// 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 b9107cd..79d3e5b 100644
+--- a/src/share/vm/oops/cpCacheOop.hpp
++++ b/src/share/vm/oops/cpCacheOop.hpp
+@@ -362,17 +362,6 @@
+
+ void update_pointers();
+
+- // RedefineClasses() API support:
+- // If this constantPoolCacheEntry refers to old_method then update it
+- // to refer to 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.
+- 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);
+-
+ // Debugging & Printing
+ void print (outputStream* st, int index) const;
+ void verify(outputStream* st) const;
+@@ -492,16 +481,8 @@
+ 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) Clear references to methods and fields from this cache.
++ void adjust_entries();
+ };
+
+ #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP
+diff --git a/src/share/vm/oops/instanceKlass.cpp b/src/share/vm/oops/instanceKlass.cpp
+index 2ddc80a..fdffaa7 100644
+--- a/src/share/vm/oops/instanceKlass.cpp
++++ b/src/share/vm/oops/instanceKlass.cpp
+@@ -255,7 +255,7 @@
+ // 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 +362,13 @@
+ jt->get_thread_stat()->perf_recursion_counts_addr(),
+ jt->get_thread_stat()->perf_timers_addr(),
+ PerfClassTraceTime::CLASS_VERIFY);
++ 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 +406,8 @@
+ }
+ #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());
+@@ -454,7 +461,9 @@
+ // If we were to use wait() instead of waitInterruptibly() then
+ // we might end up throwing IE from link/symbol resolution sites
+ // that aren't expected to throw. This would wreak havoc. See 6320309.
+- while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
++ // (tw) Wait also for the old class version to be fully initialized.
++ while((this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self))
++ || (this_oop->old_version() != NULL && ((instanceKlass*)this_oop->old_version()->klass_part())->is_being_initialized())) {
+ wait = true;
+ ol.waitUninterruptibly(CHECK);
+ }
+@@ -667,6 +676,18 @@
+ assert(Klass::cast(k)->is_interface(), "should be an interface class");
+ for (int i = 0; i < transitive_interfaces()->length(); i++) {
+ if (transitive_interfaces()->obj_at(i) == k) {
++ return true;
++ }
++ }
++ 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;
+ }
+ }
+@@ -949,6 +970,18 @@
+ }
+ }
+
++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);
++}
+
+ void instanceKlass::do_local_static_fields(FieldClosure* cl) {
+ for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
+@@ -1368,6 +1401,20 @@
+ 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 +1574,13 @@
+ 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();
+@@ -1931,16 +1985,6 @@
+ if (breakpoints() != 0x0) {
+ methods_do(clear_all_breakpoints);
+ assert(breakpoints() == 0x0, "should have cleared breakpoints");
+- }
+-
+- // deallocate information about previous versions
+- if (_previous_versions != NULL) {
+- for (int i = _previous_versions->length() - 1; i >= 0; i--) {
+- PreviousVersionNode * pv_node = _previous_versions->at(i);
+- delete pv_node;
+- }
+- delete _previous_versions;
+- _previous_versions = NULL;
+ }
+
+ // deallocate the cached class file
+@@ -2579,275 +2623,10 @@
+ }
+ #endif
+
+-
+-// RedefineClasses() support for previous versions:
+-
+-// Add an information node that contains weak references to the
+-// interesting parts of the previous version of the_class.
+-// This is also where we clean out any unused weak references.
+-// Note that while we delete nodes from the _previous_versions
+-// array, we never delete the array itself until the klass is
+-// unloaded. The has_been_redefined() query depends on that fact.
+-//
+-void instanceKlass::add_previous_version(instanceKlassHandle ikh,
+- BitMap* emcp_methods, int emcp_method_count) {
+- assert(Thread::current()->is_VM_thread(),
+- "only VMThread can add previous versions");
+-
+- if (_previous_versions == NULL) {
+- // This is the first previous version so make some space.
+- // Start with 2 elements under the assumption that the class
+- // won't be redefined much.
+- _previous_versions = new (ResourceObj::C_HEAP, mtClass)
+- GrowableArray<PreviousVersionNode *>(2, true);
+- }
+-
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
+- ikh->external_name(), _previous_versions->length(), emcp_method_count));
+- constantPoolHandle cp_h(ikh->constants());
+- jobject cp_ref;
+- if (cp_h->is_shared()) {
+- // a shared ConstantPool requires a regular reference; a weak
+- // reference would be collectible
+- cp_ref = JNIHandles::make_global(cp_h);
+- } else {
+- cp_ref = JNIHandles::make_weak_global(cp_h);
+- }
+- PreviousVersionNode * pv_node = NULL;
+- objArrayOop old_methods = ikh->methods();
+-
+- if (emcp_method_count == 0) {
+- // non-shared ConstantPool gets a weak reference
+- pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
+- RC_TRACE(0x00000400,
+- ("add: all methods are obsolete; flushing any EMCP weak refs"));
+- } else {
+- int local_count = 0;
+- GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP, mtClass)
+- GrowableArray<jweak>(emcp_method_count, true);
+- for (int i = 0; i < old_methods->length(); i++) {
+- if (emcp_methods->at(i)) {
+- // this old method is EMCP so save a weak ref
+- methodOop old_method = (methodOop) old_methods->obj_at(i);
+- methodHandle old_method_h(old_method);
+- jweak method_ref = JNIHandles::make_weak_global(old_method_h);
+- method_refs->append(method_ref);
+- if (++local_count >= emcp_method_count) {
+- // no more EMCP methods so bail out now
+- break;
+- }
+- }
+- }
+- // non-shared ConstantPool gets a weak reference
+- pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
+- }
+-
+- _previous_versions->append(pv_node);
+-
+- // Using weak references allows the interesting parts of previous
+- // classes to be GC'ed when they are no longer needed. Since the
+- // caller is the VMThread and we are at a safepoint, this is a good
+- // time to clear out unused weak references.
+-
+- RC_TRACE(0x00000400, ("add: previous version length=%d",
+- _previous_versions->length()));
+-
+- // skip the last entry since we just added it
+- for (int i = _previous_versions->length() - 2; i >= 0; i--) {
+- // check the previous versions array for a GC'ed weak refs
+- pv_node = _previous_versions->at(i);
+- cp_ref = pv_node->prev_constant_pool();
+- assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
+- if (cp_ref == NULL) {
+- delete pv_node;
+- _previous_versions->remove_at(i);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue; // robustness
+- }
+-
+- constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
+- if (cp == NULL) {
+- // this entry has been GC'ed so remove it
+- delete pv_node;
+- _previous_versions->remove_at(i);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue;
+- } else {
+- RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
+- }
+-
+- GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
+- if (method_refs != NULL) {
+- RC_TRACE(0x00000400, ("add: previous methods length=%d",
+- method_refs->length()));
+- for (int j = method_refs->length() - 1; j >= 0; j--) {
+- jweak method_ref = method_refs->at(j);
+- assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
+- if (method_ref == NULL) {
+- method_refs->remove_at(j);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue; // robustness
+- }
+-
+- methodOop method = (methodOop)JNIHandles::resolve(method_ref);
+- if (method == NULL || emcp_method_count == 0) {
+- // This method entry has been GC'ed or the current
+- // RedefineClasses() call has made all methods obsolete
+- // so remove it.
+- JNIHandles::destroy_weak_global(method_ref);
+- method_refs->remove_at(j);
+- } else {
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00000400,
+- ("add: %s(%s): previous method @%d in version @%d is alive",
+- method->name()->as_C_string(), method->signature()->as_C_string(),
+- j, i));
+- }
+- }
+- }
+- }
+-
+- int obsolete_method_count = old_methods->length() - emcp_method_count;
+-
+- if (emcp_method_count != 0 && obsolete_method_count != 0 &&
+- _previous_versions->length() > 1) {
+- // We have a mix of obsolete and EMCP methods. If there is more
+- // than the previous version that we just added, then we have to
+- // clear out any matching EMCP method entries the hard way.
+- int local_count = 0;
+- for (int i = 0; i < old_methods->length(); i++) {
+- if (!emcp_methods->at(i)) {
+- // only obsolete methods are interesting
+- methodOop old_method = (methodOop) old_methods->obj_at(i);
+- Symbol* m_name = old_method->name();
+- Symbol* m_signature = old_method->signature();
+-
+- // skip the last entry since we just added it
+- for (int j = _previous_versions->length() - 2; j >= 0; j--) {
+- // check the previous versions array for a GC'ed weak refs
+- pv_node = _previous_versions->at(j);
+- cp_ref = pv_node->prev_constant_pool();
+- assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
+- if (cp_ref == NULL) {
+- delete pv_node;
+- _previous_versions->remove_at(j);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue; // robustness
+- }
+-
+- constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
+- if (cp == NULL) {
+- // this entry has been GC'ed so remove it
+- delete pv_node;
+- _previous_versions->remove_at(j);
+- // Since we are traversing the array backwards, we don't have to
+- // do anything special with the index.
+- continue;
+- }
+-
+- GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
+- if (method_refs == NULL) {
+- // We have run into a PreviousVersion generation where
+- // all methods were made obsolete during that generation's
+- // RedefineClasses() operation. At the time of that
+- // operation, all EMCP methods were flushed so we don't
+- // have to go back any further.
+- //
+- // A NULL method_refs is different than an empty method_refs.
+- // We cannot infer any optimizations about older generations
+- // from an empty method_refs for the current generation.
+- break;
+- }
+-
+- for (int k = method_refs->length() - 1; k >= 0; k--) {
+- jweak method_ref = method_refs->at(k);
+- assert(method_ref != NULL,
+- "weak method ref was unexpectedly cleared");
+- if (method_ref == NULL) {
+- method_refs->remove_at(k);
+- // Since we are traversing the array backwards, we don't
+- // have to do anything special with the index.
+- continue; // robustness
+- }
+-
+- methodOop method = (methodOop)JNIHandles::resolve(method_ref);
+- if (method == NULL) {
+- // this method entry has been GC'ed so skip it
+- JNIHandles::destroy_weak_global(method_ref);
+- method_refs->remove_at(k);
+- continue;
+- }
+-
+- if (method->name() == m_name &&
+- method->signature() == m_signature) {
+- // The current RedefineClasses() call has made all EMCP
+- // versions of this method obsolete so mark it as obsolete
+- // and remove the weak ref.
+- RC_TRACE(0x00000400,
+- ("add: %s(%s): flush obsolete method @%d in version @%d",
+- m_name->as_C_string(), m_signature->as_C_string(), k, j));
+-
+- method->set_is_obsolete();
+- JNIHandles::destroy_weak_global(method_ref);
+- method_refs->remove_at(k);
+- break;
+- }
+- }
+-
+- // The previous loop may not find a matching EMCP method, but
+- // that doesn't mean that we can optimize and not go any
+- // further back in the PreviousVersion generations. The EMCP
+- // method for this generation could have already been GC'ed,
+- // but there still may be an older EMCP method that has not
+- // been GC'ed.
+- }
+-
+- if (++local_count >= obsolete_method_count) {
+- // no more obsolete methods so bail out now
+- break;
+- }
+- }
+- }
+- }
+-} // end add_previous_version()
+-
+-
+ // Determine if instanceKlass has a previous version.
+ bool instanceKlass::has_previous_version() const {
+- if (_previous_versions == NULL) {
+- // no previous versions array so answer is easy
+- return false;
+- }
+-
+- for (int i = _previous_versions->length() - 1; i >= 0; i--) {
+- // Check the previous versions array for an info node that hasn't
+- // been GC'ed
+- PreviousVersionNode * pv_node = _previous_versions->at(i);
+-
+- jobject cp_ref = pv_node->prev_constant_pool();
+- assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
+- if (cp_ref == NULL) {
+- continue; // robustness
+- }
+-
+- constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
+- if (cp != NULL) {
+- // we have at least one previous version
+- return true;
+- }
+-
+- // We don't have to check the method refs. If the constant pool has
+- // been GC'ed then so have the methods.
+- }
+-
+- // all of the underlying nodes' info has been GC'ed
+- return false;
+-} // end has_previous_version()
++ return _old_version != NULL;
++}
+
+ methodOop instanceKlass::method_with_idnum(int idnum) {
+ methodOop m = NULL;
+@@ -2888,153 +2667,3 @@
+ } // if no array and idnum isn't included there is nothing to do
+ }
+
+-// Construct a PreviousVersionNode entry for the array hung off
+-// the instanceKlass.
+-PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
+- bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
+-
+- _prev_constant_pool = prev_constant_pool;
+- _prev_cp_is_weak = prev_cp_is_weak;
+- _prev_EMCP_methods = prev_EMCP_methods;
+-}
+-
+-
+-// Destroy a PreviousVersionNode
+-PreviousVersionNode::~PreviousVersionNode() {
+- if (_prev_constant_pool != NULL) {
+- if (_prev_cp_is_weak) {
+- JNIHandles::destroy_weak_global(_prev_constant_pool);
+- } else {
+- JNIHandles::destroy_global(_prev_constant_pool);
+- }
+- }
+-
+- if (_prev_EMCP_methods != NULL) {
+- for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
+- jweak method_ref = _prev_EMCP_methods->at(i);
+- if (method_ref != NULL) {
+- JNIHandles::destroy_weak_global(method_ref);
+- }
+- }
+- delete _prev_EMCP_methods;
+- }
+-}
+-
+-
+-// Construct a PreviousVersionInfo entry
+-PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
+- _prev_constant_pool_handle = constantPoolHandle(); // NULL handle
+- _prev_EMCP_method_handles = NULL;
+-
+- jobject cp_ref = pv_node->prev_constant_pool();
+- assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
+- if (cp_ref == NULL) {
+- return; // robustness
+- }
+-
+- constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
+- if (cp == NULL) {
+- // Weak reference has been GC'ed. Since the constant pool has been
+- // GC'ed, the methods have also been GC'ed.
+- return;
+- }
+-
+- // make the constantPoolOop safe to return
+- _prev_constant_pool_handle = constantPoolHandle(cp);
+-
+- GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
+- if (method_refs == NULL) {
+- // the instanceKlass did not have any EMCP methods
+- return;
+- }
+-
+- _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
+-
+- int n_methods = method_refs->length();
+- for (int i = 0; i < n_methods; i++) {
+- jweak method_ref = method_refs->at(i);
+- assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
+- if (method_ref == NULL) {
+- continue; // robustness
+- }
+-
+- methodOop method = (methodOop)JNIHandles::resolve(method_ref);
+- if (method == NULL) {
+- // this entry has been GC'ed so skip it
+- continue;
+- }
+-
+- // make the methodOop safe to return
+- _prev_EMCP_method_handles->append(methodHandle(method));
+- }
+-}
+-
+-
+-// Destroy a PreviousVersionInfo
+-PreviousVersionInfo::~PreviousVersionInfo() {
+- // Since _prev_EMCP_method_handles is not C-heap allocated, we
+- // don't have to delete it.
+-}
+-
+-
+-// Construct a helper for walking the previous versions array
+-PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
+- _previous_versions = ik->previous_versions();
+- _current_index = 0;
+- // _hm needs no initialization
+- _current_p = NULL;
+-}
+-
+-
+-// Destroy a PreviousVersionWalker
+-PreviousVersionWalker::~PreviousVersionWalker() {
+- // Delete the current info just in case the caller didn't walk to
+- // the end of the previous versions list. No harm if _current_p is
+- // already NULL.
+- delete _current_p;
+-
+- // When _hm is destroyed, all the Handles returned in
+- // PreviousVersionInfo objects will be destroyed.
+- // Also, after this destructor is finished it will be
+- // safe to delete the GrowableArray allocated in the
+- // PreviousVersionInfo objects.
+-}
+-
+-
+-// Return the interesting information for the next previous version
+-// of the klass. Returns NULL if there are no more previous versions.
+-PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
+- if (_previous_versions == NULL) {
+- // no previous versions so nothing to return
+- return NULL;
+- }
+-
+- delete _current_p; // cleanup the previous info for the caller
+- _current_p = NULL; // reset to NULL so we don't delete same object twice
+-
+- int length = _previous_versions->length();
+-
+- while (_current_index < length) {
+- PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
+- PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
+- PreviousVersionInfo(pv_node);
+-
+- constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
+- if (cp_h.is_null()) {
+- delete pv_info;
+-
+- // The underlying node's info has been GC'ed so try the next one.
+- // We don't have to check the methods. If the constant pool has
+- // GC'ed then so have the methods.
+- continue;
+- }
+-
+- // Found a node with non GC'ed info so return it. The caller will
+- // need to delete pv_info when they are done with it.
+- _current_p = pv_info;
+- return pv_info;
+- }
+-
+- // all of the underlying nodes' info has been GC'ed
+- return NULL;
+-} // end next_previous_version()
+diff --git a/src/share/vm/oops/instanceKlass.hpp b/src/share/vm/oops/instanceKlass.hpp
+index f718837..2d42483 100644
+--- a/src/share/vm/oops/instanceKlass.hpp
++++ b/src/share/vm/oops/instanceKlass.hpp
+@@ -273,9 +273,6 @@
+ nmethodBucket* _dependencies; // list of dependent nmethods
+ nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
+ BreakpointInfo* _breakpoints; // bpt lists, managed by methodOop
+- // Array of interesting part(s) of the previous version(s) of this
+- // instanceKlass. See PreviousVersionWalker below.
+- GrowableArray<PreviousVersionNode *>* _previous_versions;
+ // JVMTI fields can be moved to their own structure - see 6315920
+ unsigned char * _cached_class_file_bytes; // JVMTI: cached class file, before retransformable agent modified it in CFLH
+ jint _cached_class_file_len; // JVMTI: length of above
+@@ -573,20 +570,11 @@
+ _nonstatic_oop_map_size = words;
+ }
+
+- // RedefineClasses() support for previous versions:
+- void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
+- int emcp_method_count);
+ // If the _previous_versions array is non-NULL, then this klass
+ // has been redefined at least once even if we aren't currently
+ // tracking a previous version.
+- bool has_been_redefined() const { return _previous_versions != NULL; }
++ bool has_been_redefined() const { return _old_version != NULL; }
+ bool has_previous_version() const;
+- void init_previous_versions() {
+- _previous_versions = NULL;
+- }
+- GrowableArray<PreviousVersionNode *>* previous_versions() const {
+- return _previous_versions;
+- }
+
+ // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
+ void set_cached_class_file(unsigned char *class_file_bytes,
+@@ -631,6 +619,7 @@
+ 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 +702,7 @@
+
+ // 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 +752,9 @@
+ 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 store_update_information(GrowableArray<int> &values);
++ void clear_update_information();
++
+
+ void methods_do(void f(methodOop method));
+ void array_klasses_do(void f(klassOop k));
+@@ -897,7 +890,6 @@
+ ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
+ #endif // !SERIALGC
+
+-private:
+ // initialization state
+ #ifdef ASSERT
+ void set_init_state(ClassState state);
+@@ -1063,106 +1055,6 @@
+ #endif
+ void verify(klassOop holder);
+ };
+-
+-
+-// If breakpoints are more numerous than just JVMTI breakpoints,
+-// consider compressing this data structure.
+-// It is currently a simple linked list defined in methodOop.hpp.
+-
+-class BreakpointInfo;
+-
+-
+-// A collection point for interesting information about the previous
+-// version(s) of an instanceKlass. This class uses weak references to
+-// the information so that the information may be collected as needed
+-// by the system. If the information is shared, then a regular
+-// reference must be used because a weak reference would be seen as
+-// collectible. A GrowableArray of PreviousVersionNodes is attached
+-// to the instanceKlass as needed. See PreviousVersionWalker below.
+-class PreviousVersionNode : public CHeapObj<mtClass> {
+- private:
+- // A shared ConstantPool is never collected so we'll always have
+- // a reference to it so we can update items in the cache. We'll
+- // have a weak reference to a non-shared ConstantPool until all
+- // of the methods (EMCP or obsolete) have been collected; the
+- // non-shared ConstantPool becomes collectible at that point.
+- jobject _prev_constant_pool; // regular or weak reference
+- bool _prev_cp_is_weak; // true if not a shared ConstantPool
+-
+- // If the previous version of the instanceKlass doesn't have any
+- // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
+- // EMCP methods have been collected, then _prev_EMCP_methods can
+- // have a length of zero.
+- GrowableArray<jweak>* _prev_EMCP_methods;
+-
+-public:
+- PreviousVersionNode(jobject prev_constant_pool, bool prev_cp_is_weak,
+- GrowableArray<jweak>* prev_EMCP_methods);
+- ~PreviousVersionNode();
+- jobject prev_constant_pool() const {
+- return _prev_constant_pool;
+- }
+- GrowableArray<jweak>* prev_EMCP_methods() const {
+- return _prev_EMCP_methods;
+- }
+-};
+-
+-
+-// A Handle-ized version of PreviousVersionNode.
+-class PreviousVersionInfo : public ResourceObj {
+- private:
+- constantPoolHandle _prev_constant_pool_handle;
+- // If the previous version of the instanceKlass doesn't have any
+- // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
+- // methods cannot be collected while we hold a handle,
+- // _prev_EMCP_methods should never have a length of zero.
+- GrowableArray<methodHandle>* _prev_EMCP_method_handles;
+-
+-public:
+- PreviousVersionInfo(PreviousVersionNode *pv_node);
+- ~PreviousVersionInfo();
+- constantPoolHandle prev_constant_pool_handle() const {
+- return _prev_constant_pool_handle;
+- }
+- GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
+- return _prev_EMCP_method_handles;
+- }
+-};
+-
+-
+-// Helper object for walking previous versions. This helper cleans up
+-// the Handles that it allocates when the helper object is destroyed.
+-// The PreviousVersionInfo object returned by next_previous_version()
+-// is only valid until a subsequent call to next_previous_version() or
+-// the helper object is destroyed.
+-class PreviousVersionWalker : public StackObj {
+- private:
+- GrowableArray<PreviousVersionNode *>* _previous_versions;
+- int _current_index;
+- // Fields for cleaning up when we are done walking the previous versions:
+- // A HandleMark for the PreviousVersionInfo handles:
+- HandleMark _hm;
+-
+- // It would be nice to have a ResourceMark field in this helper also,
+- // but the ResourceMark code says to be careful to delete handles held
+- // in GrowableArrays _before_ deleting the GrowableArray. Since we
+- // can't guarantee the order in which the fields are destroyed, we
+- // have to let the creator of the PreviousVersionWalker object do
+- // the right thing. Also, adding a ResourceMark here causes an
+- // include loop.
+-
+- // A pointer to the current info object so we can handle the deletes.
+- PreviousVersionInfo * _current_p;
+-
+- public:
+- PreviousVersionWalker(instanceKlass *ik);
+- ~PreviousVersionWalker();
+-
+- // Return the interesting information for the next previous version
+- // of the klass. Returns NULL if there are no more previous versions.
+- PreviousVersionInfo* next_previous_version();
+-};
+-
+
+ //
+ // nmethodBucket is used to record dependent nmethods for
+diff --git a/src/share/vm/oops/instanceKlassKlass.cpp b/src/share/vm/oops/instanceKlassKlass.cpp
+index 8e7dc12..5b9b266 100644
+--- a/src/share/vm/oops/instanceKlassKlass.cpp
++++ b/src/share/vm/oops/instanceKlassKlass.cpp
+@@ -358,7 +358,7 @@
+ unsigned nonstatic_oop_map_count,
+ AccessFlags access_flags,
+ ReferenceType rt,
+- KlassHandle host_klass, TRAPS) {
++ KlassHandle host_klass, KlassHandle old_klass, TRAPS) {
+
+ const int nonstatic_oop_map_size =
+ instanceKlass::nonstatic_oop_map_size(nonstatic_oop_map_count);
+@@ -435,7 +435,6 @@
+ ik->set_jni_ids(NULL);
+ ik->set_osr_nmethods_head(NULL);
+ ik->set_breakpoints(NULL);
+- ik->init_previous_versions();
+ ik->set_generic_signature(NULL);
+ ik->release_set_methods_jmethod_ids(NULL);
+ ik->release_set_methods_cached_itable_indices(NULL);
+@@ -480,6 +479,28 @@
+ 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();
+@@ -536,26 +557,6 @@
+ st->print_cr("%s", ik->source_debug_extension());
+ st->cr();
+ }
+-
+- {
+- ResourceMark rm;
+- // 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.
+- {
+- bool have_pv = false;
+- PreviousVersionWalker pvw(ik);
+- for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
+- pv_info != NULL; pv_info = pvw.next_previous_version()) {
+- if (!have_pv)
+- st->print(BULLET"previous version: ");
+- have_pv = true;
+- pv_info->prev_constant_pool_handle()()->print_value_on(st);
+- }
+- if (have_pv) st->cr();
+- } // pvw is cleaned up
+- } // rm is cleaned up
+
+ if (ik->generic_signature() != NULL) {
+ st->print(BULLET"generic signature: ");
+@@ -663,7 +664,7 @@
+ }
+ 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/instanceKlassKlass.hpp b/src/share/vm/oops/instanceKlassKlass.hpp
+index df674a9..45d0b66 100644
+--- a/src/share/vm/oops/instanceKlassKlass.hpp
++++ b/src/share/vm/oops/instanceKlassKlass.hpp
+@@ -50,6 +50,7 @@
+ AccessFlags access_flags,
+ ReferenceType rt,
+ KlassHandle host_klass,
++ KlassHandle old_klass,
+ TRAPS);
+
+ // Casting from klassOop
+diff --git a/src/share/vm/oops/instanceMirrorKlass.cpp b/src/share/vm/oops/instanceMirrorKlass.cpp
+index e0dd7d7..a7eec08 100644
+--- a/src/share/vm/oops/instanceMirrorKlass.cpp
++++ b/src/share/vm/oops/instanceMirrorKlass.cpp
+@@ -156,6 +156,13 @@
+ assert_is_in_closed_subset)
+ }
+
++void instanceMirrorKlass::oop_fields_iterate(oop obj, OopClosure* blk) {
++ InstanceMirrorKlass_OOP_ITERATE( \
++ start_of_static_fields(obj), java_lang_Class::static_oop_field_count(obj), \
++ blk->do_oop(p), \
++ assert_is_in_closed_subset)
++}
++
+ #ifndef SERIALGC
+ void instanceMirrorKlass::oop_follow_contents(ParCompactionManager* cm,
+ oop obj) {
+diff --git a/src/share/vm/oops/instanceMirrorKlass.hpp b/src/share/vm/oops/instanceMirrorKlass.hpp
+index 2b8b2f4..31969c7 100644
+--- a/src/share/vm/oops/instanceMirrorKlass.hpp
++++ b/src/share/vm/oops/instanceMirrorKlass.hpp
+@@ -79,6 +79,9 @@
+ DEFINE_ALLOCATE_PERMANENT(instanceMirrorKlass);
+ instanceOop allocate_instance(KlassHandle k, TRAPS);
+
++ // Class redefinition, iterate static fields
++ static void oop_fields_iterate(oop obj, OopClosure* blk);
++
+ // Garbage collection
+ int oop_adjust_pointers(oop obj);
+ void oop_follow_contents(oop obj);
+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 @@
+ 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..94406fe 100644
+--- a/src/share/vm/oops/klass.cpp
++++ b/src/share/vm/oops/klass.cpp
+@@ -170,6 +170,13 @@
+ 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_prototype_header(markOopDesc::prototype());
+ kl->set_biased_lock_revocation_count(0);
+ kl->set_last_biased_lock_bulk_revocation_time(0);
+@@ -241,7 +248,7 @@
+ 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);
+@@ -394,7 +401,7 @@
+ void Klass::remove_from_sibling_list() {
+ // remove receiver from sibling list
+ instanceKlass* super = superklass();
+- assert(super != NULL || as_klassOop() == SystemDictionary::Object_klass(), "should have super");
++ assert(super != NULL || as_klassOop()->klass_part()->newest_version() == SystemDictionary::Object_klass()->klass_part()->newest_version(), "should have super");
+ if (super == NULL) return; // special case: class Object
+ if (super->subklass() == this) {
+ // first subklass
+diff --git a/src/share/vm/oops/klass.hpp b/src/share/vm/oops/klass.hpp
+index a449e87..d2490b7 100644
+--- a/src/share/vm/oops/klass.hpp
++++ b/src/share/vm/oops/klass.hpp
+@@ -171,6 +171,7 @@
+ 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 +224,31 @@
+ 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 has been marked as an affected class.
++ MarkedAsAffected = RemoveSuperType << 1
++ };
++
+ protected:
+ //
+ // The oop block. All oop fields must be declared here and only oop fields
+@@ -242,6 +268,10 @@
+ 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
+@@ -253,6 +283,16 @@
+
+ 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?
++ bool _original_field_offsets_changed; // Did the original field offsets of this class change during class redefinition?
++ int * _update_information; // Update information
++ bool _is_redefining;
+
+ #ifndef PRODUCT
+ int _verify_count; // to avoid redundant verifies
+@@ -301,6 +341,75 @@
+
+ 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; }
++ void set_redefinition_flag(int flag) { _redefinition_flags |= flag; }
++ void clear_redefinition_flag(int flag) { _redefinition_flags &= ~flag; }
++ 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; }
++
++ 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;
++ }
++
++ 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 +471,8 @@
+ 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; }
+diff --git a/src/share/vm/oops/klassKlass.cpp b/src/share/vm/oops/klassKlass.cpp
+index 06809d5..1050eda 100644
+--- a/src/share/vm/oops/klassKlass.cpp
++++ b/src/share/vm/oops/klassKlass.cpp
+@@ -68,6 +68,8 @@
+ 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 @@
+ 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 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());
+@@ -133,6 +139,10 @@
+ Klass* k = Klass::cast(klassOop(obj));
+ 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;
+@@ -167,6 +177,8 @@
+ 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/klassVtable.cpp b/src/share/vm/oops/klassVtable.cpp
+index ff22444..b366b73 100644
+--- a/src/share/vm/oops/klassVtable.cpp
++++ b/src/share/vm/oops/klassVtable.cpp
+@@ -649,17 +649,13 @@
+ if (unchecked_method_at(index) == old_method) {
+ put_method_at(new_method, index);
+
+- if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
++ IF_TRACE_RC4 {
+ 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_RC4("adjust: name=%s", Klass::cast(old_method->method_holder())->external_name());
+ *trace_name_printed = true;
+ }
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00100000, ("vtable method update: %s(%s)",
+- new_method->name()->as_C_string(),
+- new_method->signature()->as_C_string()));
++ TRACE_RC4("vtable method update: %s(%s)", new_method->name()->as_C_string(),
++ new_method->signature()->as_C_string());
+ }
+ // cannot 'break' here; see for-loop comment above.
+ }
+@@ -1029,17 +1025,13 @@
+ if (ime->method() == old_method) {
+ ime->initialize(new_method);
+
+- if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
++ IF_TRACE_RC4 {
+ 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_RC4("adjust: name=%s", Klass::cast(old_method->method_holder())->external_name());
+ *trace_name_printed = true;
+ }
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00200000, ("itable method update: %s(%s)",
+- new_method->name()->as_C_string(),
+- new_method->signature()->as_C_string()));
++ TRACE_RC4("itable method update: %s(%s)", new_method->name()->as_C_string(),
++ new_method->signature()->as_C_string());
+ }
+ // cannot 'break' here; see for-loop comment above.
+ }
+@@ -1262,6 +1254,7 @@
+
+ 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 +1274,8 @@
+
+ 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 +1283,13 @@
+ #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);
++ }
++ }
+ }
+ }
+
+@@ -1296,8 +1297,8 @@
+
+ void vtableEntry::print() {
+ ResourceMark rm;
+- tty->print("vtableEntry %s: ", method()->name()->as_C_string());
+ if (Verbose) {
++ tty->print("vtableEntry %s: ", (method() == NULL) ? "null" : method()->name()->as_C_string());
+ tty->print("m %#lx ", (address)method());
+ }
+ }
+diff --git a/src/share/vm/oops/methodKlass.cpp b/src/share/vm/oops/methodKlass.cpp
+index 75d0b09..c4be146 100644
+--- a/src/share/vm/oops/methodKlass.cpp
++++ b/src/share/vm/oops/methodKlass.cpp
+@@ -93,6 +93,9 @@
+ m->set_adapter_entry(NULL);
+ m->clear_code(); // from_c/from_i get set to c2i/i2i
+
++ 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 +125,8 @@
+ // 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_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 +140,8 @@
+ // 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_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 +159,8 @@
+ // 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_new_version());
++ blk->do_oop(m->adr_old_version());
+ if (m->method_data() != NULL) {
+ blk->do_oop(m->adr_method_data());
+ }
+@@ -170,6 +179,10 @@
+ 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_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 +200,8 @@
+ // 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_new_version());
++ MarkSweep::adjust_pointer(m->adr_old_version());
+ if (m->method_data() != NULL) {
+ MarkSweep::adjust_pointer(m->adr_method_data());
+ }
+@@ -202,6 +217,8 @@
+ assert(obj->is_method(), "should be method");
+ methodOop m = methodOop(obj);
+ PSParallelCompact::adjust_pointer(m->adr_constMethod());
++ 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 +239,18 @@
+ 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..32cb4cf 100644
+--- a/src/share/vm/oops/methodOop.cpp
++++ b/src/share/vm/oops/methodOop.cpp
+@@ -1061,6 +1061,8 @@
+
+ // Reset correct method/const method, method size, and parameter info
+ newm->set_constMethod(newcm);
++ 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..e35d5ed 100644
+--- a/src/share/vm/oops/methodOop.hpp
++++ b/src/share/vm/oops/methodOop.hpp
+@@ -114,6 +114,10 @@
+ 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 _new_version;
++ methodOop _old_version;
++
+ #ifdef CC_INTERP
+ int _result_index; // C++ interpreter needs for converting results to/from stack
+ #endif
+@@ -174,6 +178,29 @@
+ Symbol* name() const { return constants()->symbol_at(name_index()); }
+ int name_index() const { return constMethod()->name_index(); }
+ void set_name_index(int index) { constMethod()->set_name_index(index); }
++
++ 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()); }
+@@ -734,6 +761,8 @@
+
+ // Garbage collection support
+ oop* adr_constMethod() const { return (oop*)&_constMethod; }
++ 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 @@
+ 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 @@
+ 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_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_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 50e1263..701ed74 100644
+--- a/src/share/vm/prims/jni.cpp
++++ b/src/share/vm/prims/jni.cpp
+@@ -406,7 +406,7 @@
+ }
+ }
+ 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 c87af13..bb4b5d8 100644
+--- a/src/share/vm/prims/jvm.cpp
++++ b/src/share/vm/prims/jvm.cpp
+@@ -947,7 +947,7 @@
+ 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/jvm_misc.hpp b/src/share/vm/prims/jvm_misc.hpp
+index 2b46e36..549e949 100644
+--- a/src/share/vm/prims/jvm_misc.hpp
++++ b/src/share/vm/prims/jvm_misc.hpp
+@@ -84,6 +84,7 @@
+ (JNIEnv *env, jobject obj, jfieldID fieldID);
+ }
+
++// TODO(tw): Check if we need to "unquicken" because of class redefinition.
+ void quicken_jni_functions();
+ address jni_GetBooleanField_addr();
+ address jni_GetByteField_addr();
+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 @@
+ 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 @@
+ // 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 @@
+ // 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..31a8a19 100644
+--- a/src/share/vm/prims/jvmtiImpl.cpp
++++ b/src/share/vm/prims/jvmtiImpl.cpp
+@@ -284,60 +284,11 @@
+ }
+
+ void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
+- ((methodOopDesc*)_method->*meth_act)(_bci);
+-
+- // add/remove breakpoint to/from versions of the method that
+- // are EMCP. Directly or transitively obsolete methods are
+- // not saved in the PreviousVersionInfo.
+- Thread *thread = Thread::current();
+- instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
+- Symbol* m_name = _method->name();
+- Symbol* m_signature = _method->signature();
+-
+- {
+- 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.
+- {
+- // search previous versions if they exist
+- PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part());
+- for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
+- pv_info != NULL; pv_info = pvw.next_previous_version()) {
+- GrowableArray<methodHandle>* methods =
+- pv_info->prev_EMCP_method_handles();
+-
+- if (methods == NULL) {
+- // We have run into a PreviousVersion generation where
+- // all methods were made obsolete during that generation's
+- // RedefineClasses() operation. At the time of that
+- // operation, all EMCP methods were flushed so we don't
+- // have to go back any further.
+- //
+- // A NULL methods array is different than an empty methods
+- // array. We cannot infer any optimizations about older
+- // generations from an empty methods array for the current
+- // generation.
+- break;
+- }
+-
+- for (int i = methods->length() - 1; i >= 0; i--) {
+- methodHandle method = methods->at(i);
+- if (method->name() == m_name && method->signature() == m_signature) {
+- RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
+- meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear",
+- method->name()->as_C_string(),
+- method->signature()->as_C_string()));
+- assert(!method->is_obsolete(), "only EMCP methods here");
+-
+- ((methodOopDesc*)method()->*meth_act)(_bci);
+- break;
+- }
+- }
+- }
+- } // pvw is cleaned up
+- } // rm is cleaned up
++ methodOop method = _method;
++ while (method != NULL) {
++ ((methodOopDesc*)method->*meth_act)(_bci);
++ method = method->old_version();
++ }
+ }
+
+ void JvmtiBreakpoint::set() {
+diff --git a/src/share/vm/prims/jvmtiRedefineClasses.cpp b/src/share/vm/prims/jvmtiRedefineClasses.cpp
+index 606be1c..cb90823 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
+@@ -35,545 +35,57 @@
+ #include "prims/jvmtiImpl.hpp"
+ #include "prims/jvmtiRedefineClasses.hpp"
+ #include "prims/methodComparator.hpp"
+-#include "prims/methodHandles.hpp"
+ #include "runtime/deoptimization.hpp"
+ #include "runtime/relocator.hpp"
+ #include "utilities/bitMap.inline.hpp"
++#include "prims/jvmtiClassFileReconstituter.hpp"
++#include "compiler/compileBroker.hpp"
++#include "oops/instanceMirrorKlass.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;
++GrowableArray<instanceKlassHandle>* VM_RedefineClasses::_affected_klasses = NULL;
+
+
+-VM_RedefineClasses::VM_RedefineClasses(jint class_count,
+- const jvmtiClassDefinition *class_defs,
+- JvmtiClassLoadKind class_load_kind) {
++// 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_GC_Operation(Universe::heap()->total_full_collections(), GCCause::_heap_inspection) {
++ RC_TIMER_START(_timer_total);
+ _class_count = class_count;
+ _class_defs = class_defs;
+ _class_load_kind = class_load_kind;
+- _res = JVMTI_ERROR_NONE;
++ _result = JVMTI_ERROR_NONE;
+ }
+
+-bool VM_RedefineClasses::doit_prologue() {
+- if (_class_count == 0) {
+- _res = JVMTI_ERROR_NONE;
+- return false;
+- }
+- if (_class_defs == NULL) {
+- _res = JVMTI_ERROR_NULL_POINTER;
+- return false;
+- }
+- 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;
+- }
+- }
++VM_RedefineClasses::~VM_RedefineClasses() {
++ unlock_threads();
++ RC_TIMER_STOP(_timer_total);
+
+- // 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);
+-
+- // 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;
+- }
+-
+- RC_TIMER_STOP(_timer_vm_op_prologue);
+- return true;
+-}
+-
+-void VM_RedefineClasses::doit() {
+- Thread *thread = Thread::current();
+-
+- 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;
+- }
+- }
+-
+- 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();
+-
+- // Set flag indicating that some invariants are no longer true.
+- // See jvmtiExport.hpp for detailed explanation.
+- JvmtiExport::set_has_redefined_a_class();
+-
+-// 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
+-}
+-
+-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 (TimeRedefineClasses) {
++ tty->print_cr("");
++ 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 Prepare Redefinition: %d", _timer_prepare_redefinition.milliseconds());
++ tty->print_cr("Timing Heap Iteration: %d", _timer_heap_iteration.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());
++ tty->print_cr("");
+ }
+ }
+-
+-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;
+-}
+-
+-// 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);
+-
+- 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_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");
+- break;
+- }
+-
+- 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));
+- }
+- 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 (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_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
+-
+- 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;
+- }
+- }
+- return new_bs_i;
+-} // end find_or_append_operand()
+-
+-
+-void VM_RedefineClasses::finalize_operands_merge(constantPoolHandle merge_cp, TRAPS) {
+- if (merge_cp->operands() == NULL) {
+- return;
+- }
+- // Shrink the merge_cp operands
+- merge_cp->shrink_operands(_operands_cur_length, CHECK);
+-
+- 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++;
+- }
+- }
+- }
+- // 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;
+@@ -591,20 +103,604 @@
+ scratch_class->set_method_default_annotations_of(j, save);
+ }
+
++void VM_RedefineClasses::add_affected_klasses( klassOop klass )
++{
++ assert(!_affected_klasses->contains(klass), "must not occur more than once!");
++ assert(klass->klass_part()->new_version() == NULL, "Only last version is valid entry in system dictionary");
+
+-jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
+- instanceKlassHandle the_class,
+- instanceKlassHandle scratch_class) {
++ Klass* k = klass->klass_part();
++
++ if (k->check_redefinition_flag(Klass::MarkedAsAffected)) {
++ _affected_klasses->append(klass);
++ return;
++ }
++
++ for (juint i = 0; i < k->super_depth(); i++) {
++ klassOop primary_oop = k->primary_super_of_depth(i);
++ // super_depth returns "8" for interfaces, but they don't have primaries other than Object.
++ if (primary_oop == NULL) break;
++ Klass* primary = Klass::cast(primary_oop);
++ if (primary->check_redefinition_flag(Klass::MarkedAsAffected)) {
++ TRACE_RC3("Found affected class: %s", k->name()->as_C_string());
++ k->set_redefinition_flag(Klass::MarkedAsAffected);
++ _affected_klasses->append(klass);
++ return;
++ }
++ }
++
++ // Check secondary supers
++ int cnt = k->secondary_supers()->length();
++ for (int i = 0; i < cnt; i++) {
++ Klass* secondary = Klass::cast((klassOop) k->secondary_supers()->obj_at(i));
++ if (secondary->check_redefinition_flag(Klass::MarkedAsAffected)) {
++ TRACE_RC3("Found affected class: %s", k->name()->as_C_string());
++ k->set_redefinition_flag(Klass::MarkedAsAffected);
++ _affected_klasses->append(klass);
++ return;
++ }
++ }
++}
++
++
++// 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() {
++
++ assert(_affected_klasses, "");
++ 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));
++ klass_handle->set_redefinition_flag(Klass::MarkedAsAffected);
++ assert(klass_handle->new_version() == NULL, "Must be new class");
++ }
++
++ // Find classes not directly redefined, but affected by a redefinition (because one of its supertypes is redefined)
++ SystemDictionary::classes_do(VM_RedefineClasses::add_affected_klasses);
++ TRACE_RC1("%d classes affected", _affected_klasses->length());
++
++ // 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, Thread::current());
++ IF_TRACE_RC2 {
++ TRACE_RC2("Redefine order: ");
++ for (int i = 0; i < _affected_klasses->length(); i++) {
++ TRACE_RC2("%s", _affected_klasses->at(i)->name()->as_C_string());
++ }
++ }
++
++ return result;
++}
++
++// 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) {
++
++ *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;
++ }
++ }
++
++ if (j == _class_count) {
++
++ *not_changed = true;
++
++ // 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.
++
++ 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();
++
++ TRACE_RC3("Reconstituted class 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();
++
++
++ TRACE_RC3("Retrieved cached class 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;
++}
++
++// Prologue of the VM operation, called on the Java thread in parallel to normal program execution
++bool VM_RedefineClasses::doit_prologue() {
++
++ _revision_number++;
++ TRACE_RC1("Redefinition with revision number %d started!", _revision_number);
++ lock_threads();
++
++ 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;
++ }
++
++ // 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);
++
++ assert(_affected_klasses == NULL, "");
++ _affected_klasses = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceKlassHandle>(_class_count, true);
++
++
++ _result = load_new_class_versions(Thread::current());
++
++ TRACE_RC1("Loaded new class versions!");
++ if (_result != JVMTI_ERROR_NONE) {
++ TRACE_RC1("error occured: %d!", _result);
++ delete _new_classes;
++ _new_classes = NULL;
++ delete _affected_klasses;
++ _affected_klasses = NULL;
++ RC_TIMER_STOP(_timer_prologue);
++ return false;
++ }
++
++ TRACE_RC2("nearly finished");
++ VM_GC_Operation::doit_prologue();
++ RC_TIMER_STOP(_timer_prologue);
++ TRACE_RC2("doit_prologue finished!");
++ return true;
++}
++
++// Checks basic properties of the arguments of the redefinition command.
++jvmtiError VM_RedefineClasses::check_arguments_error() {
++ if (_class_defs == NULL) return JVMTI_ERROR_NULL_POINTER;
++ for (int i = 0; i < _class_count; i++) {
++ if (_class_defs[i].klass == NULL) return JVMTI_ERROR_INVALID_CLASS;
++ if (_class_defs[i].class_byte_count == 0) return JVMTI_ERROR_INVALID_CLASS_FORMAT;
++ if (_class_defs[i].class_bytes == NULL) return JVMTI_ERROR_NULL_POINTER;
++ }
++ return JVMTI_ERROR_NONE;
++}
++
++// Returns false and sets an result error code if the redefinition should be aborted.
++bool VM_RedefineClasses::check_arguments() {
++ jvmtiError error = check_arguments_error();
++ if (error != JVMTI_ERROR_NONE || _class_count == 0) {
++ _result = error;
++ return false;
++ }
++ 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();
++ TRACE_RC1("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);
++
++ TRACE_RC1("===================================================================");
++ TRACE_RC1("redefinition started by thread \"%s\"", THREAD->name());
++ TRACE_RC1("load new class versions (%d)", _class_count);
++
++ // Retrieve an array of all classes that need to be redefined
++ jvmtiError err = find_sorted_affected_classes();
++ if (err != JVMTI_ERROR_NONE) {
++ TRACE_RC1("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<_affected_klasses->length(); i++) {
++ TRACE_RC2("Processing affected class %d of %d", i+1, _affected_klasses->length());
++
++ instanceKlassHandle the_class = _affected_klasses->at(i);
++ TRACE_RC2("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, ¬_changed)) != JVMTI_ERROR_NONE) {
++ TRACE_RC1("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);
++
++ TRACE_RC2("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());
++ ClassFileStream st((u1*) class_bytes, class_byte_count, (char *)"__VM_RedefineClasses__");
++ instanceKlassHandle new_class(THREAD, SystemDictionary::resolve_from_stream(the_class->name(),
++ the_class_loader,
++ protection_domain,
++ &st,
++ true,
++ the_class,
++ THREAD));
++
++ RC_TIMER_STOP(_timer_class_loading);
++ RC_TIMER_START(_timer_prologue);
++
++ TRACE_RC2("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;
++
++ not_changed = false;
++
++#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()) {
++
++ TRACE_RC2("name=%s loader="INTPTR_FORMAT" protection_domain="INTPTR_FORMAT, the_class->name()->as_C_string(), the_class->class_loader(), 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;
++ }
++ }
++
++#endif
++
++ IF_TRACE_RC1 {
++ if (new_class->layout_helper() != the_class->layout_helper()) {
++ TRACE_RC1("Instance size change for class %s: new=%d old=%d", new_class->name()->as_C_string(), new_class->layout_helper(), the_class->layout_helper());
++ }
++ }
++
++ // 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);
++ if (redefinition_flags >= Klass::RemoveSuperType) {
++ TRACE_RC1("Remove super type is not allowed");
++ result = JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
++ break;
++ }
++ } else {
++ jvmtiError allowed = check_redefinition_allowed(new_class);
++ if (allowed != JVMTI_ERROR_NONE) {
++ TRACE_RC1("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);
++
++ _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 {
++ // Fields were not changed, transfer special flags only
++ 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");
++
++ JavaFieldStream old_fs(the_class);
++ JavaFieldStream new_fs(new_class);
++ for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) {
++ AccessFlags flags = new_fs.access_flags();
++ flags.set_is_field_modification_watched(old_fs.access_flags().is_field_modification_watched());
++ flags.set_is_field_access_watched(old_fs.access_flags().is_field_access_watched());
++ new_fs.set_access_flags(flags);
++ }
++ }
++
++ IF_TRACE_RC3 {
++ if (new_class->super() != NULL) {
++ TRACE_RC3("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
++
++ TRACE_RC2("Verification done!");
++
++ if (i == _affected_klasses->length() - 1) {
++
++ // This was the last class processed => check if additional classes have been loaded in the meantime
++
++ for (int j=0; j<_affected_klasses->length(); j++) {
++
++ klassOop initial_klass = _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() && !cur_klass->is_redefining()) {
++ instanceKlassHandle handle(THREAD, cur_klass->as_klassOop());
++ if (!_affected_klasses->contains(handle)) {
++
++ int k = i + 1;
++ for (; k<_affected_klasses->length(); k++) {
++ if (_affected_klasses->at(k)->is_subtype_of(cur_klass->as_klassOop())) {
++ break;
++ }
++ }
++ _affected_klasses->insert_before(k, handle);
++ TRACE_RC2("Adding newly loaded class to affected classes: %s", cur_klass->name()->as_C_string());
++ }
++ }
++
++ cur_klass = cur_klass->next_sibling();
++ }
++ }
++
++ int new_count = _affected_klasses->length() - 1 - i;
++ if (new_count != 0) {
++
++ TRACE_RC1("Found new number of affected classes: %d", new_count);
++ }
++ }
++ }
++
++ 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<_affected_klasses->length(); i++) {
++ instanceKlassHandle the_class = _affected_klasses->at(i);
++ instanceKlassHandle new_class(the_class->new_version());
++
++ TRACE_RC2("Linking class %d/%d %s", i, _affected_klasses->length(), the_class->name()->as_C_string());
++ new_class->link_class(THREAD);
++
++ result = check_exception();
++ if (result != JVMTI_ERROR_NONE) break;
++ }
++ RC_TIMER_STOP(_timer_class_linking);
++ RC_TIMER_START(_timer_prologue);
++
++ if (result != JVMTI_ERROR_NONE) {
++ rollback();
++ return result;
++ }
++
++ TRACE_RC2("All classes loaded!");
++
++#ifdef ASSERT
++ for (int i=0; i<_affected_klasses->length(); i++) {
++ instanceKlassHandle the_class = _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
++
++ TRACE_RC1("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();
++ }
++
++ TRACE_RC2("Locked %d compiler threads", cnt);
++
++ cnt = 0;
++ javaThread = Threads::first();
++ while (javaThread != NULL) {
++ if (javaThread != Thread::current()) {
++ javaThread->redefine_classes_mutex()->lock();
++ cnt++;
++ }
++ javaThread = javaThread->next();
++ }
++
++
++ TRACE_RC2("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();
++ }
++
++ TRACE_RC2("Unlocked %d compiler threads", cnt);
++
++ 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();
++ cnt++;
++ }
++ }
++ javaThread = javaThread->next();
++ }
++
++ TRACE_RC2("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());
++
+ 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 +718,8 @@
+ }
+ 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 +868,8 @@
+ 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 +878,11 @@
+ // 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 +897,19 @@
+ 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:
+@@ -833,2119 +920,1332 @@
+ 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;
++ int result = Klass::NoRedefinition;
++
++
++
++ TRACE_RC2("Comparing different class versions of class %s", new_class->name()->as_C_string());
++
++ assert(new_class->old_version() != NULL, "must have old version");
++ instanceKlassHandle the_class(new_class->old_version());
++
++ // 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);
+ }
+
+- 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 i;
+
+- int value = _index_map_p->at(old_index);
+- if (value == -1) {
+- // the old_index is not mapped
+- return 0;
+- }
++ //////////////////////////////////////////////////////////////////////////////////////////////////////////
++ // 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
+
+- return value;
+-} // end find_new_index()
++ klassOop cur_klass = the_class->super();
++ while (cur_klass != NULL) {
++ if (!new_class->is_subclass_of(cur_klass->klass_part()->newest_version())) {
++ TRACE_RC2("Removed super class %s", cur_klass->klass_part()->name()->as_C_string());
++ result = result | Klass::RemoveSuperType | Klass::ModifyInstances | Klass::ModifyClass;
+
+-
+-// 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;
+- }
+-
+- 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;
+- }
+-
+- 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) {
+-
+- 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
+- }
+-
+- 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
+- }
+-
+- if (t1 == t2) {
+- return false; // not a mismatch; not our special case
+- }
+-
+- 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
+- }
+-
+- 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
+- }
+-
+- 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
+- }
+-
+- 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;
+- }
+-
+- 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);
+-
+- 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();
+-
+- // 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;
+- } else {
+- return JVMTI_ERROR_INTERNAL;
++ if (!cur_klass->klass_part()->has_subtype_changed()) {
++ TRACE_RC2("Subtype changed of class %s", cur_klass->klass_part()->name()->as_C_string());
++ cur_klass->klass_part()->set_subtype_changed(true);
+ }
+ }
++
++ cur_klass = cur_klass->klass_part()->super();
+ }
+
+- // 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;
+- }
+-
+- // 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;
++ cur_klass = new_class->super();
++ while (cur_klass != NULL) {
++ if (!the_class->is_subclass_of(cur_klass->klass_part()->old_version())) {
++ TRACE_RC2("Added super class %s", cur_klass->klass_part()->name()->as_C_string());
++ result = result | Klass::ModifyClass | Klass::ModifyInstances;
+ }
+- }
+-
+- res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
+- if (res != JVMTI_ERROR_NONE) {
+- return res;
+- }
+-
+- 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);
+- }
+-
+- 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;
+- }
+- }
+- }
+-
+- Rewriter::rewrite(scratch_class, THREAD);
+- if (!HAS_PENDING_EXCEPTION) {
+- Rewriter::relocate_and_link(scratch_class, THREAD);
+- }
+- 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;
+- }
+- }
+-
+- _scratch_classes[i] = scratch_class;
+-
+- // 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));
+- }
+-
+- return JVMTI_ERROR_NONE;
+-}
+-
+-
+-// 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;
+- }
+-
+- if (old_index == new_index) {
+- // no mapping is needed
+- return;
+- }
+-
+- _index_map_p->at_put(old_index, new_index);
+- _index_map_count++;
+-
+- 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()
+-
+-
+-// 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;
+- }
+-
+- if (old_index == new_index) {
+- // no mapping is needed
+- return;
+- }
+-
+- _operands_index_map_p->at_put(old_index, new_index);
+- _operands_index_map_count++;
+-
+- RC_TRACE(0x00040000, ("mapped bootstrap specifier at index %d to %d", old_index, new_index));
+-} // end map_index()
+-
+-
+-// 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) {
+-
+- 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
+- }
+-
+- RC_TRACE_WITH_THREAD(0x00010000, THREAD,
+- ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
+- scratch_cp->length()));
+-
+- {
+- // 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;
+-
+- 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;
+-
+- 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;
+- }
+- } // 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);
+-
+- // 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;
+- }
+-
+- // 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));
+-
+- 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;
+-
+- default:
+- increment = 1;
+- break;
+- }
+-
+- 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);
++ cur_klass = cur_klass->klass_part()->super();
+ }
+ }
+
+- 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));
++ //////////////////////////////////////////////////////////////////////////////////////////////////////////
++ // Check interfaces
+
+- 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;
+-
+- default:
+- increment = 1;
+- break;
++ // 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;
++ TRACE_RC2("Removed interface %s", old_interface->name()->as_C_string());
++
++ if (!old_interface->has_subtype_changed()) {
++ TRACE_RC2("Subtype changed of interface %s", old_interface->name()->as_C_string());
++ old_interface->set_subtype_changed(true);
+ }
+-
+- 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;
+- }
+-
+- // 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 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
+- *merge_cp_length_p, scratch_i, _index_map_count));
+- }
+- 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());
+ }
+
+- ResourceMark rm(THREAD);
+- _index_map_count = 0;
+- _index_map_p = new intArray(scratch_cp->length(), -1);
+-
+- _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);
+-
+- // 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);
+-
+- if (!result) {
+- // The merge can fail due to memory allocation failure or due
+- // to robustness checks.
+- return JVMTI_ERROR_INTERNAL;
++ // 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;
++ TRACE_RC2("Added interface %s", ((klassOop)new_interfaces->obj_at(i))->klass_part()->name()->as_C_string());
++ }
+ }
+
+- 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
++ // 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?
++ }
++
++ // 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) {
++ // TODO (tw) can this have any effect?
++ }
++ // 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;
++ }
++ }
+
+- 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.
++ // If both streams aren't done then we have a differing number of
++ // fields.
++ if (!old_fs.done() || !new_fs.done()) {
++ result = result | Klass::ModifyInstances;
++ }
+
+- 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.
++ // 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();
+
+- merge_cp()->set_is_conc_safe(true);
+- merge_cp = constantPoolHandle(); // toss the merged constant pool
++ int ni = 0;
++ int oi = 0;
++ while (true) {
++ methodOop k_old_method;
++ methodOop k_new_method;
++ enum { matched, added, deleted, undetermined } method_was = undetermined;
++
++ 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 {
+- // 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.
++ // 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 {
++ 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;
++ }
++ }
+
+- // 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();
+- }
+- } 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++;
++ if (nj >= n_new_methods) {
++ // reached the end without a match; so method was deleted
++ method_was = deleted;
+ }
+ }
+ }
+
+- // 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;
++ 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;
+ }
+-
+- // 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);
+- }
+- 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()
+-
+-
+-// Rewrite constant pool references in klass scratch_class.
+-bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
+- TRAPS) {
+-
+- // rewrite constant pool references in the methods:
+- if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
+- // propagate failure back to caller
+- return false;
+- }
+-
+- // 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;
+- }
+-
+- // 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;
+- }
+-
+- // 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;
+- }
+-
+- // 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;
+- }
+-
+- // 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 true;
+-} // end rewrite_cp_refs()
+-
+-
+-// Rewrite constant pool references in the methods.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
+- instanceKlassHandle scratch_class, TRAPS) {
+-
+- objArrayHandle methods(THREAD, scratch_class->methods());
+-
+- if (methods.is_null() || methods->length() == 0) {
+- // no methods so nothing to do
+- return true;
+- }
+-
+- // 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());
++ {
++ 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);
++ TRACE_RC2("swapping idnum of new and old method %d / %d!", new_num, old_num);
++ swap_all_method_annotations(old_num, new_num, new_class);
++ }
++ }
++ TRACE_RC3("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;
++ }
++ {
++ u2 num = the_class->next_method_idnum();
++ if (num == constMethodOopDesc::UNSET_IDNUM) {
++ // cannot add any more methods
++ result = result | Klass::ModifyClass;
++ }
++ 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);
++ }
++ TRACE_RC1("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;
++ }
++ TRACE_RC1("Method deleted: old: %s [%d]",
++ k_old_method->name_and_sig_as_C_string(), oi);
++ ++oi; // advance to next old method
++ break;
++ default:
++ ShouldNotReachHere();
+ }
+ }
+
+- return true;
++ if (new_class()->size() != new_class->old_version()->size()) {
++ result |= Klass::ModifyClassSize;
++ }
++
++ if (new_class->size_helper() != ((instanceKlass*)(new_class->old_version()->klass_part()))->size_helper()) {
++ result |= Klass::ModifyInstanceSize;
++ }
++
++ // (tw) Check method bodies to be able to return NoChange?
++ return result;
++}
++
++void VM_RedefineClasses::calculate_instance_update_information(klassOop new_version) {
++
++ class CalculateFieldUpdates : public FieldClosure {
++
++ private:
++ instanceKlass* _old_ik;
++ GrowableArray<int> _update_info;
++ int _position;
++ bool _copy_backwards;
++
++ public:
++
++ bool does_copy_backwards() {
++ return _copy_backwards;
++ }
++
++ CalculateFieldUpdates(instanceKlass* old_ik) :
++ _old_ik(old_ik), _position(instanceOopDesc::base_offset_in_bytes()), _copy_backwards(false) {
++ _update_info.append(_position);
++ _update_info.append(0);
++ }
++
++ GrowableArray<int> &finish() {
++ _update_info.append(0);
++ return _update_info;
++ }
++
++ void do_field(fieldDescriptor* fd) {
++ int alignment = fd->offset() - _position;
++ if (alignment > 0) {
++ // This field was aligned, so we need to make sure that we fill the gap
++ fill(alignment);
++ }
++
++ assert(_position == fd->offset(), "must be correct offset!");
++
++ fieldDescriptor old_fd;
++ if (_old_ik->find_field(fd->name(), fd->signature(), false, &old_fd) != NULL) {
++ // Found field in the old class, copy
++ copy(old_fd.offset(), type2aelembytes(fd->field_type()));
++
++ if (old_fd.offset() < fd->offset()) {
++ _copy_backwards = true;
++ }
++
++ // Transfer special flags
++ fd->set_is_field_modification_watched(old_fd.is_field_modification_watched());
++ fd->set_is_field_access_watched(old_fd.is_field_access_watched());
++ } else {
++ // New field, fill
++ fill(type2aelembytes(fd->field_type()));
++ }
++ }
++
++ private:
++
++ void fill(int size) {
++ if (_update_info.length() > 0 && _update_info.at(_update_info.length() - 1) < 0) {
++ (*_update_info.adr_at(_update_info.length() - 1)) -= size;
++ } else {
++ _update_info.append(-size);
++ }
++ _position += size;
++ }
++
++ void copy(int offset, int size) {
++ int prev_end = -1;
++ if (_update_info.length() > 0 && _update_info.at(_update_info.length() - 1) > 0) {
++ prev_end = _update_info.at(_update_info.length() - 2) + _update_info.at(_update_info.length() - 1);
++ }
++
++ if (prev_end == offset) {
++ (*_update_info.adr_at(_update_info.length() - 2)) += size;
++ } else {
++ _update_info.append(size);
++ _update_info.append(offset);
++ }
++
++ _position += size;
++ }
++ };
++
++ instanceKlass* ik = instanceKlass::cast(new_version);
++ instanceKlass* old_ik = instanceKlass::cast(new_version->klass_part()->old_version());
++ CalculateFieldUpdates cl(old_ik);
++ ik->do_nonstatic_fields(&cl);
++
++ GrowableArray<int> result = cl.finish();
++ ik->store_update_information(result);
++ ik->set_copying_backwards(cl.does_copy_backwards());
++
++ IF_TRACE_RC2 {
++ TRACE_RC2("Instance update information for %s:", new_version->klass_part()->name()->as_C_string());
++ if (cl.does_copy_backwards()) {
++ TRACE_RC2("\tDoes copy backwards!");
++ }
++ for (int i=0; i<result.length(); i++) {
++ int curNum = result.at(i);
++ if (curNum < 0) {
++ TRACE_RC2("\t%d CLEAN", curNum);
++ } else if (curNum > 0) {
++ TRACE_RC2("\t%d COPY from %d", curNum, result.at(i + 1));
++ i++;
++ } else {
++ TRACE_RC2("\tEND");
++ }
++ }
++ }
++}
++
++void VM_RedefineClasses::rollback() {
++ TRACE_RC1("Rolling back redefinition!");
++ SystemDictionary::rollback_redefinition();
++
++ TRACE_RC1("After rolling back system dictionary!");
++ for (int i=0; i<_new_classes->length(); i++) {
++ SystemDictionary::remove_from_hierarchy(_new_classes->at(i));
++ }
++
++ 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);
++ }
++
++}
++
++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);
+ }
+
+
+-// 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) {
++class FieldCopier : public FieldClosure {
++ public:
++ void do_field(fieldDescriptor* fd) {
++ instanceKlass* cur = instanceKlass::cast(fd->field_holder());
++ oop cur_oop = cur->java_mirror();
+
+- *new_method_p = methodHandle(); // default is no new method
++ instanceKlass* old = instanceKlass::cast(cur->old_version());
++ oop old_oop = old->java_mirror();
+
+- // 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;
++ fieldDescriptor result;
++ bool found = old->find_local_field(fd->name(), fd->signature(), &result);
++ if (found && result.is_static()) {
++ TRACE_RC3("Copying static field value for field %s old_offset=%d new_offset=%d",
++ fd->name()->as_C_string(), result.offset(), fd->offset());
++ memcpy(cur_oop->obj_field_addr<HeapWord>(fd->offset()),
++ old_oop->obj_field_addr<HeapWord>(result.offset()),
++ type2aelembytes(fd->field_type()));
+
+- // Bytecodes and their length
+- address code_base = method->code_base();
+- int code_length = method->code_size();
++ // Static fields may have references to java.lang.Class
++ if (fd->field_type() == T_OBJECT) {
++ oop oop = cur_oop->obj_field(fd->offset());
++ if (oop != NULL && oop->is_instanceMirror()) {
++ klassOop klass = java_lang_Class::as_klassOop(oop);
++ if (klass != NULL && klass->klass_part()->oop_is_instance()) {
++ assert(oop == instanceKlass::cast(klass)->java_mirror(), "just checking");
++ if (klass->klass_part()->new_version() != NULL) {
++ oop = instanceKlass::cast(klass->klass_part()->new_version())->java_mirror();
+
+- int bc_length;
+- for (int bci = 0; bci < code_length; bci += bc_length) {
+- address bcp = code_base + bci;
+- Bytecodes::Code c = (Bytecodes::Code)(*bcp);
+-
+- 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);
+- }
+-
+- assert(bc_length != 0, "impossible bytecode length");
+-
+- switch (c) {
+- case Bytecodes::_ldc:
+- {
+- int cp_index = *(bcp + 1);
+- int new_index = find_new_index(cp_index);
+-
+- 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;
++ cur_oop->obj_field_put(fd->offset(), oop);
++ }
++ }
+ }
+- 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);
++void VM_RedefineClasses::mark_as_scavengable(nmethod* nm) {
++ if (!nm->on_scavenge_root_list()) {
++ CodeCache::add_scavenge_root_nmethod(nm);
++ }
++}
+
+- // 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");
++struct StoreBarrier {
++ template <class T> static void oop_store(T* p, oop v) { ::oop_store(p, v); }
++};
++
++struct StoreNoBarrier {
++ template <class T> static void oop_store(T* p, oop v) { oopDesc::encode_store_heap_oop_not_null(p, v); }
++};
++
++template <class S>
++class ChangePointersOopClosure : public OopClosureNoHeader {
++ // Forward pointers to instanceKlass and mirror class to new versions
++ template <class T>
++ inline void do_oop_work(T* p) {
++ oop oop = oopDesc::load_decode_heap_oop(p);
++ if (oop == NULL) {
++ return;
++ }
++ if (oop->is_instanceKlass()) {
++ klassOop klass = (klassOop) oop;
++ if (klass->klass_part()->new_version() != NULL) {
++ oop = klass->klass_part()->new_version();
++ S::oop_store(p, oop);
++ }
++ } else if (oop->is_instanceMirror()) {
++ klassOop klass = java_lang_Class::as_klassOop(oop);
++ if (klass != NULL && klass->klass_part()->oop_is_instance()) {
++ assert(oop == instanceKlass::cast(klass)->java_mirror(), "just checking");
++ if (klass->klass_part()->new_version() != NULL) {
++ oop = instanceKlass::cast(klass->klass_part()->new_version())->java_mirror();
++ S::oop_store(p, oop);
++ }
++ }
++ }
++ }
++
++ virtual void do_oop(oop* o) {
++ do_oop_work(o);
++ }
++
++ virtual void do_oop(narrowOop* o) {
++ do_oop_work(o);
++ }
++};
++
++void VM_RedefineClasses::doit() {
++ Thread *thread = Thread::current();
++
++ TRACE_RC1("Entering doit!");
++
++ assert((_max_redefinition_flags & Klass::RemoveSuperType) == 0, "removing super types not allowed");
++
++ 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()) {
++ TRACE_RC1("failed to remap shared readonly space to readwrite, private");
++ _result = JVMTI_ERROR_INTERNAL;
++ return;
++ }
++ }
++
++ 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());
++
++ // Adjust constantpool caches and vtables for all classes
++ // that reference methods of the evolved class.
++ SystemDictionary::classes_do(adjust_cpool_cache, Thread::current());
++
++ RC_TIMER_STOP(_timer_prepare_redefinition);
++ RC_TIMER_START(_timer_heap_iteration);
++
++ class ChangePointersObjectClosure : public ObjectClosure {
++
++ private:
++
++ OopClosureNoHeader *_closure;
++ bool _needs_instance_update;
++ oop _tmp_obj;
++ int _tmp_obj_size;
++
++ public:
++ ChangePointersObjectClosure(OopClosureNoHeader *closure) : _closure(closure), _needs_instance_update(false), _tmp_obj(NULL), _tmp_obj_size(0) {}
++
++ bool needs_instance_update() {
++ return _needs_instance_update;
++ }
++
++ void copy_to_tmp(oop o) {
++ int size = o->size();
++ if (_tmp_obj_size < size) {
++ _tmp_obj_size = size;
++ _tmp_obj = (oop)resource_allocate_bytes(size * HeapWordSize);
++ }
++ Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)_tmp_obj, size);
++ }
++
++ virtual void do_object(oop obj) {
++ if (obj->is_instanceKlass()) return;
++ if (obj->is_instanceMirror()) {
++ // static fields may have references to old java.lang.Class instances, update them
++ // at the same time, we don't want to update other oops in the java.lang.Class
++ // Causes SIGSEGV?
++ //instanceMirrorKlass::oop_fields_iterate(obj, _closure);
++ } else {
++ obj->oop_iterate(_closure);
++ }
++
++ // Update method handles
++ // FIXME: should we also update fields?
++ if (java_lang_invoke_MemberName::is_instance(obj)) {
++ oop target = java_lang_invoke_MemberName::vmtarget(obj);
++ if (target != NULL && target->is_method()) {
++ methodOop m = (methodOop) target;
++ klassOop holder = m->method_holder();
++ if (!holder->klass_part()->is_newest_version()) {
++ // Let's try to re-resolve method
++ klassOop newest = holder->klass_part()->newest_version();
++ methodOop new_method = instanceKlass::cast(newest)->find_method(m->name(), m->signature());
++ java_lang_invoke_MemberName::set_vmtarget(obj, new_method);
++ }
++ }
++ }
++
++ if (obj->blueprint()->new_version() != NULL) {
++ Klass* new_klass = obj->blueprint()->new_version()->klass_part();
++ if (obj->is_perm()) {
++ _needs_instance_update = true;
++ } else if(new_klass->update_information() != NULL) {
++ int size_diff = obj->size() - obj->size_given_klass(new_klass);
++
++ // Either new size is bigger or gap is to small to be filled
++ if (size_diff < 0 || (size_diff > 0 && (size_t) size_diff < CollectedHeap::min_fill_size())) {
++ // We need an instance update => set back to old klass
++ _needs_instance_update = true;
++ } else {
++ oop src = obj;
++ if (new_klass->is_copying_backwards()) {
++ copy_to_tmp(obj);
++ src = _tmp_obj;
++ }
++ src->set_klass_no_check(obj->blueprint()->new_version());
++ MarkSweep::update_fields(obj, src, new_klass->update_information());
++
++ if (size_diff > 0) {
++ HeapWord* dead_space = ((HeapWord *)obj) + obj->size();
++ CollectedHeap::fill_with_object(dead_space, size_diff);
+ }
+ }
+-
+- // 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);
++ } else {
++ obj->set_klass_no_check(obj->blueprint()->new_version());
++ }
+ }
+- } break;
++ }
++ };
++
++ ChangePointersOopClosure<StoreNoBarrier> oopClosureNoBarrier;
++ ChangePointersOopClosure<StoreBarrier> oopClosure;
++ ChangePointersObjectClosure objectClosure(&oopClosure);
++
++ {
++ // Since we may update oops inside nmethod's code blob to point to java.lang.Class in new generation, we need to
++ // make sure such references are properly recognized by GC. For that, If ScavengeRootsInCode is true, we need to
++ // mark such nmethod's as "scavengable".
++ // For now, mark all nmethod's as scavengable that are not scavengable already
++ if (ScavengeRootsInCode) {
++ CodeCache::nmethods_do(mark_as_scavengable);
++ }
++
++ SharedHeap::heap()->gc_prologue(true);
++ Universe::heap()->object_iterate(&objectClosure);
++ Universe::root_oops_do(&oopClosureNoBarrier);
++ SharedHeap::heap()->gc_epilogue(false);
+ }
+- } // end for each bytecode
+-} // end rewrite_cp_refs_in_method()
+
+
+-// Rewrite constant pool references in the class_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
+- instanceKlassHandle scratch_class, TRAPS) {
++ for (int i=0; i<_new_classes->length(); i++) {
++ klassOop cur_oop = _new_classes->at(i)();
++ instanceKlass* cur = instanceKlass::cast(cur_oop);
++ klassOop old_oop = cur->old_version();
++ instanceKlass* old = instanceKlass::cast(old_oop);
+
+- 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;
++ // Swap marks to have same hashcodes
++ swap_marks(cur_oop, old_oop);
++ swap_marks(cur->java_mirror(), old->java_mirror());
++
++ // Revert pool holder for old version of klass (it was updated by one of ours closure!)
++ old->constants()->set_pool_holder(old_oop);
++
++
++ if (old->array_klasses() != NULL) {
++ // Transfer the array classes, otherwise we might get cast exceptions when casting array types.
++ assert(cur->array_klasses() == NULL, "just checking");
++ cur->set_array_klasses(old->array_klasses());
++ }
++
++ // 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.
++ FieldCopier copier;
++ cur->do_local_static_fields(&copier); // TODO (tw): What about internal static fields??
++ old->set_java_mirror(cur->java_mirror());
++
++ // Transfer init state
++ instanceKlass::ClassState state = old->init_state();
++ if (state > instanceKlass::linked) {
++ cur->set_init_state(state);
++ }
++ }
++
++ RC_TIMER_STOP(_timer_heap_iteration);
++ RC_TIMER_START(_timer_redefinition);
++ if (objectClosure.needs_instance_update()){
++
++ // Do a full garbage collection to update the instance sizes accordingly
++ TRACE_RC1("Before performing full GC!");
++ Universe::set_redefining_gc_run(true);
++ notify_gc_begin(true);
++ Universe::heap()->collect_as_vm_thread(GCCause::_heap_inspection);
++ notify_gc_end();
++ Universe::set_redefining_gc_run(false);
++ TRACE_RC1("GC done!");
+ }
+
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("class_annotations length=%d", class_annotations->length()));
++ // Unmark klassOops as "redefining"
++ for (int i=0; i<_new_classes->length(); i++) {
++ klassOop cur_klass = _new_classes->at(i)();
++ instanceKlass* cur = (instanceKlass*)cur_klass->klass_part();
++ cur->set_redefining(false);
++ cur->clear_update_information();
++ }
+
+- int byte_i = 0; // byte index into class_annotations
+- return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
+- THREAD);
++ // 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
++ ciObjectFactory::resort_shared_ci_objects();
++
++#ifdef ASSERT
++
++ // Universe::verify();
++ // JNIHandles::verify();
++
++ SystemDictionary::classes_do(check_class, thread);
++#endif
++
++ RC_TIMER_STOP(_timer_redefinition);
++
++ if (TraceRedefineClasses > 0) {
++ tty->flush();
++ }
+ }
+
++void VM_RedefineClasses::doit_epilogue() {
+
+-// 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) {
++ RC_TIMER_START(_timer_vm_op_epilogue);
+
+- 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;
+- }
++ //unlock_threads();
+
+- u2 num_annotations = Bytes::get_Java_u2((address)
+- annotations_typeArray->byte_at_addr(byte_i_ref));
+- byte_i_ref += 2;
++ ResourceMark mark;
+
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("num_annotations=%d", num_annotations));
++ VM_GC_Operation::doit_epilogue();
++ TRACE_RC1("GC Operation epilogue finished! ");
+
+- 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;
+- }
+- }
+- assert(num_annotations == calc_num_annotations, "sanity check");
++ // Free the array of scratch classes
++ delete _new_classes;
++ _new_classes = NULL;
+
+- return true;
+-} // end rewrite_cp_refs_in_annotations_typeArray()
++ // Free the array of affected classes
++ delete _affected_klasses;
++ _affected_klasses = NULL;
+
++ TRACE_RC1("Redefinition finished!");
+
+-// 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;
+- }
+-
+- 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;
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("type_index=%d num_element_value_pairs=%d", type_index,
+- num_element_value_pairs));
+-
+- 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;
+- }
+-
+- u2 element_name_index = rewrite_cp_ref_in_annotation_data(
+- annotations_typeArray, byte_i_ref,
+- "mapped old element_name_index=%d", THREAD);
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("element_name_index=%d", element_name_index));
+-
+- 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;
+- }
+- } // 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_STOP(_timer_vm_op_epilogue);
+ }
+
+-
+-// 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) {
+-
+- 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"));
++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;
+ }
+-
+- 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.
+-
+- 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;
+- }
+-
+- u2 const_value_index = rewrite_cp_ref_in_annotation_data(
+- annotations_typeArray, byte_i_ref,
+- "mapped old const_value_index=%d", THREAD);
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("const_value_index=%d", const_value_index));
+- } break;
+-
+- case 'e':
+- {
+- // for the above tag value, value.enum_const_value is right union field
+-
+- 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;
+- }
+-
+- u2 type_name_index = rewrite_cp_ref_in_annotation_data(
+- annotations_typeArray, byte_i_ref,
+- "mapped old type_name_index=%d", THREAD);
+-
+- u2 const_name_index = rewrite_cp_ref_in_annotation_data(
+- annotations_typeArray, byte_i_ref,
+- "mapped old const_name_index=%d", THREAD);
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("type_name_index=%d const_name_index=%d", type_name_index,
+- const_name_index));
+- } break;
+-
+- case 'c':
+- {
+- // for the above tag value, value.class_info_index is right union field
+-
+- 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;
+- }
+-
+- u2 class_info_index = rewrite_cp_ref_in_annotation_data(
+- annotations_typeArray, byte_i_ref,
+- "mapped old class_info_index=%d", THREAD);
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("class_info_index=%d", class_info_index));
+- } break;
+-
+- 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;
+-
+- 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;
+- }
+- }
+- 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
+-
++ 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;
+-} // end rewrite_cp_refs_in_element_value()
++}
+
++#ifdef ASSERT
+
+-// Rewrite constant pool references in a fields_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
+- instanceKlassHandle scratch_class, TRAPS) {
++void VM_RedefineClasses::verify_classes(klassOop k_oop_latest, oop initiating_loader, TRAPS) {
++ klassOop k_oop = k_oop_latest;
++ while (k_oop != NULL) {
+
+- objArrayHandle fields_annotations(THREAD,
+- scratch_class->fields_annotations());
+-
+- if (fields_annotations.is_null() || fields_annotations->length() == 0) {
+- // no fields_annotations so nothing to do
+- return true;
++ instanceKlassHandle k_handle(THREAD, k_oop);
++ Verifier::verify(k_handle, Verifier::ThrowException, true, true, THREAD);
++ k_oop = k_oop->klass_part()->old_version();
+ }
++}
+
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("fields_annotations length=%d", fields_annotations->length()));
++#endif
+
+- 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;
+- }
++// 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.
++void VM_RedefineClasses::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();
+
+- 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;
+- }
+- }
+-
+- return true;
+-} // end rewrite_cp_refs_in_fields_annotations()
+-
+-
+-// Rewrite constant pool references in a methods_annotations field.
+-bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
+- instanceKlassHandle scratch_class, TRAPS) {
+-
+- objArrayHandle methods_annotations(THREAD,
+- scratch_class->methods_annotations());
+-
+- 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;
+- }
+-
+- 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;
+- }
+- }
+-
+- return true;
+-} // end rewrite_cp_refs_in_methods_annotations()
+-
+-
+-// 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) {
+-
+- objArrayHandle methods_parameter_annotations(THREAD,
+- scratch_class->methods_parameter_annotations());
+-
+- if (methods_parameter_annotations.is_null()
+- || methods_parameter_annotations->length() == 0) {
+- // no methods_parameter_annotations so nothing to do
+- return true;
+- }
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("methods_parameter_annotations length=%d",
+- methods_parameter_annotations->length()));
+-
+- 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;
+- }
+-
+- int byte_i = 0; // byte index into method_parameter_annotations
+-
+- u1 num_parameters = method_parameter_annotations->byte_at(byte_i);
+- byte_i++;
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("num_parameters=%d", num_parameters));
+-
+- 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;
++ 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);
+ }
+- }
+- assert(num_parameters == calc_num_parameters, "sanity check");
+- }
+-
+- return true;
+-} // end rewrite_cp_refs_in_methods_parameter_annotations()
+-
+-
+-// 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) {
+-
+- objArrayHandle methods_default_annotations(THREAD,
+- scratch_class->methods_default_annotations());
+-
+- if (methods_default_annotations.is_null()
+- || methods_default_annotations->length() == 0) {
+- // no methods_default_annotations so nothing to do
+- return true;
+- }
+-
+- RC_TRACE_WITH_THREAD(0x02000000, THREAD,
+- ("methods_default_annotations length=%d",
+- methods_default_annotations->length()));
+-
+- 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;
+- }
+-
+- int byte_i = 0; // byte index into method_default_annotations
+-
+- 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;
+- }
+- }
+-
+- return true;
+-} // end rewrite_cp_refs_in_methods_default_annotations()
+-
+-
+-// 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);
++ } 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;
+ }
+ }
+
+- // 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);
+- }
++ // 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);
+ }
+- } // 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;
+-
+- // 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;
+-
+- 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
+-
+- 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()
+-
+-
+-// Unevolving classes may point to methods of the_class directly
++// 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.
++// to fix up these pointers. Additional field offsets and vtable indices
++// in the constant pool cache entries are fixed.
+ //
+ // 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;
++void VM_RedefineClasses::adjust_cpool_cache(klassOop k_oop_latest, oop initiating_loader, TRAPS) {
++ klassOop k_oop = k_oop_latest;
++ while (k_oop != NULL) {
++ Klass *k = k_oop->klass_part();
++ if (k->oop_is_instance()) {
++ HandleMark hm(THREAD);
++ instanceKlass *ik = (instanceKlass *) k;
+
+- // 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;
+- }
++ constantPoolHandle other_cp;
++ constantPoolCacheOop cp_cache;
+
+- // 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());
++
++ 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) {
++
++ // (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!");
++ }
++ }
++
+ 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);
++ cp_cache->adjust_entries();
++ }
++
++ // If bytecode rewriting is enabled, we also need to unpatch bytecode to force resolution of zeroed entries
++ if (RewriteBytecodes) {
++ ik->methods_do(unpatch_bytecode);
+ }
+ }
+- {
+- 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
++ k_oop = k_oop->klass_part()->old_version();
+ }
+ }
+
+ void VM_RedefineClasses::update_jmethod_ids() {
+ for (int j = 0; j < _matching_methods_length; ++j) {
+- methodOop old_method = _matching_old_methods[j];
++ methodOop old_method = (methodOop)_old_methods->obj_at(_matching_old_methods[j]);
++ TRACE_RC3("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(_matching_new_methods[j]);
++ 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);
++ //TRACE_RC3("Changed jmethodID for old method assigned to %d / result=%d", new_jmethod_id, result);
++ //TRACE_RC3("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);
++ //TRACE_RC3("Changed jmethodID for new method assigned to %d / result=%d", jmid, result);
++ }
+ JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h);
+- assert(JNIHandles::resolve_jmethod_id(jmid) == _matching_new_methods[j],
+- "should be replaced");
++ //TRACE_RC3("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!");
++
++ //TRACE_RC3("jmethodID new method: %d jmethodID old method: %d", new_method_h->jmethod_id(), old_method->jmethod_id());
+ }
+ }
+ }
+
+-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;
+- }
++// Deoptimize all compiled code that depends on this class.
++//
++// If the can_redefine_classes capability is obtained in the onload
++// phase then the compiler has recorded all dependencies from startup.
++// In that case we need only deoptimize and throw away all compiled code
++// that depends on the class.
++//
++// If can_redefine_classes is obtained sometime after the onload
++// phase then the dependency information may be incomplete. In that case
++// the first call to RedefineClasses causes all compiled code to be
++// thrown away. As can_redefine_classes has been obtained then
++// all future compilations will record dependencies so second and
++// subsequent calls to RedefineClasses need only throw away code
++// that depends on the class.
++//
++void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
++ assert_locked_or_safepoint(Compile_lock);
+
+- 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.
++ // All dependencies have been recorded from startup or this is a second or
++ // subsequent use of RedefineClasses
+
+- // track which methods are EMCP for add_previous_version() call
+- emcp_methods->set_bit(old_index);
+- (*emcp_method_count_p)++;
++ // 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();
+
+- // 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++;
++ ResourceMark rm(THREAD);
++ DeoptimizationMarker dm;
+
+- // 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
++ // Deoptimize all activations depending on marked nmethods
++ Deoptimization::deoptimize_dependents();
++
++ // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
++ CodeCache::make_marked_nmethods_not_entrant();
++
++ // From now on we know that the dependency information is complete
++ JvmtiExport::set_all_dependencies_are_recorded(true);
++ }
++}
++
++void VM_RedefineClasses::compute_added_deleted_matching_methods() {
++ methodOop old_method;
++ methodOop new_method;
++
++ _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;
++ _added_methods_length = 0;
++
++ int nj = 0;
++ int oj = 0;
++ while (true) {
++ if (oj >= _old_methods->length()) {
++ if (nj >= _new_methods->length()) {
++ break; // we've looked at everything, done
+ }
++ // New method at the end
++ new_method = (methodOop) _new_methods->obj_at(nj);
++ _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++] = 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 ] = 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++] = 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++] = nj;//new_method;
++ ++nj;
++ } else {
++ // deleted method
++ _deleted_methods[_deleted_methods_length++] = oj;//old_method;
++ ++oj;
++ }
++ }
++ }
++ }
++ assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
++ assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
++ TRACE_RC3("Matching methods = %d / deleted methods = %d / added methods = %d", _matching_methods_length, _deleted_methods_length, _added_methods_length);
++}
++
++
++
++// Install the redefinition of a class:
++// - house keeping (flushing breakpoints and caches, deoptimizing
++// dependent compiled code)
++// - adjusting constant pool caches and vtables in other classes
++void VM_RedefineClasses::redefine_single_class(instanceKlassHandle the_new_class, TRAPS) {
++
++ ResourceMark rm(THREAD);
++
++ 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");
++
++ 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_old_class());
++#endif // !JVMTI_KERNEL
++
++ 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_old_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
++ }
++
++ _old_methods = the_old_class->methods();
++ _new_methods = the_new_class->methods();
++ compute_added_deleted_matching_methods();
++
++ // track which methods are EMCP for add_previous_version() call below
++
++ // (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);
++ update_jmethod_ids();
++
++ // TODO:
++ transfer_old_native_function_registrations(the_old_class);
++
++
++
++#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();
++
++// 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_old_class()->klass_part(), THREAD);
++
++}
++
++
++void VM_RedefineClasses::check_methods_and_mark_as_obsolete(BitMap *emcp_methods, int * emcp_method_count_p) {
++ TRACE_RC3("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);
++
++ TRACE_RC3("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()) {
++ TRACE_RC2("Checking breakpoint");
++ TRACE_RC2("%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");
++ TRACE_RC2("Found a breakpoint in an old EMCP method");
++ new_method->set_breakpoint(bp->bci());
++ }
++ }
++ } 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.
++ TRACE_RC3("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]);
++
++ //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 %s(%s) as obsolete",
++ TRACE_RC3("mark deleted %s(%s) as obsolete",
+ old_method->name()->as_C_string(),
+- old_method->signature()->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 = _deleted_methods[i];
++ //assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(), "sanity check");
++ TRACE_RC3("EMCP_cnt=%d, obsolete_cnt=%d !", *emcp_method_count_p, obsolete_count);
++}
+
+- assert(old_method->vtable_index() < 0,
+- "cannot delete methods with vtable entries");;
++// Increment the classRedefinedCount field in the specific instanceKlass
++// and in all direct and indirect subclasses.
++void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) {
++ oop class_mirror = ik->java_mirror();
++ 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);
++ TRACE_RC3("updated count for class=%s to %d", ik->external_name(), new_count);
++}
+
+- // 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()));
++#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_or_obsolete_entries()) {
++ TRACE_RC1("size of class: %d\n", k_oop->size());
++ TRACE_RC1("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name());
++ assert(false, "OLD method found");
++ }
++
++ ik->vtable()->verify(tty, true);
++ }
+ }
+- 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));
++}
++
++#endif
++
++static bool match_right(void* value, Pair<klassOop, klassOop> elem) {
++ return elem.right() == value;
++}
++
++jvmtiError VM_RedefineClasses::do_topological_class_sorting( const jvmtiClassDefinition *class_defs, int class_count, TRAPS)
++{
++ GrowableArray< Pair<klassOop, klassOop> > links;
++
++ for (int i=0; i<class_count; i++) {
++
++ oop mirror = JNIHandles::resolve_non_null(class_defs[i].klass);
++ instanceKlassHandle the_class(THREAD, java_lang_Class::as_klassOop(mirror));
++ 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;
++ TempNewSymbol parsed_name;
++ TRACE_RC2("Before find super symbols of class %s", the_class->name()->as_C_string());
++ cfp.parseClassFile(the_class->name(), the_class_loader, protection_domain, the_class, KlassHandle(), NULL, &symbolArr, parsed_name, false, THREAD);
++
++ for (int j=0; j<symbolArr.length(); j++) {
++ Symbol* sym = symbolArr.at(j);
++ TRACE_RC3("Before adding link to super class %s", sym->as_C_string());
++ klassOop super_klass = SystemDictionary::resolve_or_null(sym, the_class_loader, protection_domain, THREAD);
++ if (super_klass != NULL) {
++ instanceKlassHandle the_super_class(THREAD, super_klass);
++ if (_affected_klasses->contains(the_super_class)) {
++ TRACE_RC2("Found class to link");
++ links.append(Pair<klassOop, klassOop>(super_klass, the_class()));
++ }
++ }
++ }
++
++ assert(the_class->check_redefinition_flag(Klass::MarkedAsAffected), "");
++ the_class->clear_redefinition_flag(Klass::MarkedAsAffected);
++ }
++
++
++ TRACE_RC1("Identified links between classes! ");
++
++ for (int i=0; i < _affected_klasses->length(); i++) {
++ instanceKlassHandle klass = _affected_klasses->at(i);
++
++ if (klass->check_redefinition_flag(Klass::MarkedAsAffected)) {
++ klass->clear_redefinition_flag(Klass::MarkedAsAffected);
++ klassOop superKlass = klass->super();
++ if (_affected_klasses->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 (_affected_klasses->contains(interfaceKlass)) {
++ links.append(Pair<klassOop, klassOop>(interfaceKlass, klass()));
++ }
++ }
++ }
++ }
++
++ IF_TRACE_RC2 {
++ TRACE_RC2("Identified links: ");
++ for (int i=0; i<links.length(); i++) {
++ TRACE_RC2("%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 < _affected_klasses->length(); i++) {
++ int j;
++ for (j = i; j < _affected_klasses->length(); j++) {
++ // Search for node with no incoming edges
++ klassOop oop = _affected_klasses->at(j)();
++ int k = links.find(oop, match_right);
++ if (k == -1) break;
++ }
++ if (j == _affected_klasses->length()) {
++ return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
++ }
++
++ // Remove all links from this node
++ klassOop oop = _affected_klasses->at(j)();
++ int k = 0;
++ while (k < links.length()) {
++ if (links.adr_at(k)->left() == oop) {
++ links.delete_at(k);
++ } else {
++ k++;
++ }
++ }
++
++ // Swap node
++ instanceKlassHandle tmp = _affected_klasses->at(j);
++ _affected_klasses->at_put(j, _affected_klasses->at(i));
++ _affected_klasses->at_put(i, tmp);
++ }
++
++ return JVMTI_ERROR_NONE;
+ }
+
+ // This internal class transfers the native function registration from old methods
+@@ -2969,7 +2269,7 @@
+ // Same, caused by prefix removal only 3_2_1_m -> 3_2_m
+ //
+ class TransferNativeFunctionRegistration {
+- private:
++private:
+ instanceKlassHandle the_class;
+ int prefix_count;
+ char** prefixes;
+@@ -2982,42 +2282,42 @@
+ // (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
++ 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
++ // 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 NULL; // This whole branch bore nothing
+ }
+
+ // Return the method name with old prefixes stripped away.
+@@ -3042,10 +2342,10 @@
+ ResourceMark rm;
+ char* name_str = method_name_without_prefixes(method);
+ return search_prefix_name_space(0, name_str, strlen(name_str),
+- method->signature());
++ method->signature());
+ }
+
+- public:
++public:
+
+ // Construct a native method transfer processor for this class.
+ TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
+@@ -3056,9 +2356,9 @@
+ }
+
+ // Attempt to transfer any of the old or deleted methods that are native
+- void transfer_registrations(methodOop* old_methods, int methods_length) {
++ void transfer_registrations(instanceKlassHandle old_klass, int* old_methods, int methods_length) {
+ for (int j = 0; j < methods_length; j++) {
+- methodOop old_method = old_methods[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);
+@@ -3067,7 +2367,9 @@
+ // 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);
++ !methodOopDesc::native_bind_event_is_interesting);
++
++ TRACE_RC3("Transfering native function for method %s", old_method->name()->as_C_string());
+ }
+ }
+ }
+@@ -3075,544 +2377,8 @@
+ };
+
+ // 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
+-// phase then the compiler has recorded all dependencies from startup.
+-// In that case we need only deoptimize and throw away all compiled code
+-// that depends on the class.
+-//
+-// If can_redefine_classes is obtained sometime after the onload
+-// phase then the dependency information may be incomplete. In that case
+-// the first call to RedefineClasses causes all compiled code to be
+-// thrown away. As can_redefine_classes has been obtained then
+-// all future compilations will record dependencies so second and
+-// subsequent calls to RedefineClasses need only throw away code
+-// that depends on the class.
+-//
+-void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
+- assert_locked_or_safepoint(Compile_lock);
+-
+- // All dependencies have been recorded from startup or this is a second or
+- // subsequent use of RedefineClasses
+- if (JvmtiExport::all_dependencies_are_recorded()) {
+- Universe::flush_evol_dependents_on(k_h);
+- } else {
+- CodeCache::mark_all_nmethods_for_deoptimization();
+-
+- ResourceMark rm(THREAD);
+- DeoptimizationMarker dm;
+-
+- // Deoptimize all activations depending on marked nmethods
+- Deoptimization::deoptimize_dependents();
+-
+- // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
+- CodeCache::make_marked_nmethods_not_entrant();
+-
+- // From now on we know that the dependency information is complete
+- JvmtiExport::set_all_dependencies_are_recorded(true);
+- }
+-}
+-
+-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_methods_length = 0;
+- _deleted_methods_length = 0;
+- _added_methods_length = 0;
+-
+- int nj = 0;
+- int oj = 0;
+- while (true) {
+- if (oj >= _old_methods->length()) {
+- if (nj >= _new_methods->length()) {
+- break; // we've looked at everything, done
+- }
+- // New method at the end
+- new_method = (methodOop) _new_methods->obj_at(nj);
+- _added_methods[_added_methods_length++] = new_method;
+- ++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;
+- ++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;
+- ++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;
+- ++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;
+- ++nj;
+- } else {
+- // deleted method
+- _deleted_methods[_deleted_methods_length++] = old_method;
+- ++oj;
+- }
+- }
+- }
+- }
+- assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
+- assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
+-}
+-
+-
+-
+-// 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) {
+-
+- RC_TIMER_START(_timer_rsc_phase1);
+-
+- 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);
+-
+- // 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);
+-
+- if (the_class_oop == 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()));
+- }
+-
+- // 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;
+- 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());
+- int emcp_method_count = 0;
+- emcp_methods.clear(); // clears 0..(length() - 1)
+- 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);
+-
+- // keep track of previous versions of this class
+- the_class->add_previous_version(scratch_class, &emcp_methods,
+- emcp_method_count);
+-
+- RC_TIMER_STOP(_timer_rsc_phase1);
+- RC_TIMER_START(_timer_rsc_phase2);
+-
+- // 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);
+- }
+-
+- 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();
+- }
+-
+- // 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);
+-
+- // 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));
+-
+- RC_TIMER_STOP(_timer_rsc_phase2);
+-} // end redefine_single_class()
+-
+-
+-// Increment the classRedefinedCount field in the specific instanceKlass
+-// and in all direct and indirect subclasses.
+-void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) {
+- oop class_mirror = ik->java_mirror();
+- 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);
+-
+- 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));
+- }
+-
+- 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::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);
+-
+- // 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.");
+- }
+- guarantee(false, "OLD and/or OBSOLETE method(s) found");
+- }
+- }
+-}
+-
+-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_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..8333cee 100644
+--- a/src/share/vm/prims/jvmtiRedefineClasses.hpp
++++ b/src/share/vm/prims/jvmtiRedefineClasses.hpp
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2003, 2013, 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
+@@ -30,332 +30,29 @@
+ #include "memory/resourceArea.hpp"
+ #include "oops/objArrayKlass.hpp"
+ #include "oops/objArrayOop.hpp"
++#include "oops/fieldStreams.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 {
++// New version that allows arbitrary changes to already loaded classes.
++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;
++
++ static GrowableArray<instanceKlassHandle>* _affected_klasses;
+
+ // The instance fields are used to pass information from
+ // doit_prologue() to doit() and doit_epilogue().
+@@ -366,46 +63,27 @@
+ // RetransformClasses. Indicate which.
+ JvmtiClassLoadKind _class_load_kind;
+
+- // _index_map_count is just an optimization for knowing if
+- // _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;
++ 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;
++ elapsedTimer _timer_total;
++ elapsedTimer _timer_prologue;
++ elapsedTimer _timer_class_linking;
++ elapsedTimer _timer_class_loading;
++ elapsedTimer _timer_prepare_redefinition;
++ elapsedTimer _timer_wait_for_locks;
++ elapsedTimer _timer_heap_iteration;
++ elapsedTimer _timer_redefinition;
++ elapsedTimer _timer_vm_op_epilogue;
+
+- // 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).
++ jvmtiError check_redefinition_allowed(instanceKlassHandle new_class);
++ jvmtiError find_sorted_affected_classes( );
++ 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
+@@ -414,103 +92,71 @@
+ // 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);
++ void swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class);
+
+- // 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 void add_affected_klasses( klassOop obj );
++
++ static jvmtiError do_topological_class_sorting(const jvmtiClassDefinition *class_definitions, int class_count, 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);
++
++ static void unpatch_bytecode(methodOop method);
++
++#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 mark_as_scavengable(nmethod* nm);
++
++ bool check_arguments();
++ jvmtiError check_arguments_error();
+
+ 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 doit_prologue();
+ void doit();
+ void doit_epilogue();
++ void rollback();
+
+- bool allow_nested_vm_operations() const { return true; }
+- jvmtiError check_error() { return _res; }
++ 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; }
+
+ // Modifiable test must be shared between IsModifiableClass query
+ // and redefine implementation
+ static bool is_modifiable_class(oop klass_mirror);
++
++ // Utility methods for transfering field access flags
++
++ static void transfer_special_access_flags(JavaFieldStream *from, JavaFieldStream *to);
++ static void transfer_special_access_flags(fieldDescriptor *from, fieldDescriptor *to);
++
++ void transfer_old_native_function_registrations(instanceKlassHandle the_class);
++
++ void lock_threads();
++ void unlock_threads();
++
++ static void swap_marks(oop first, oop second);
++
+ };
+
+ #endif // SHARE_VM_PRIMS_JVMTIREDEFINECLASSES_HPP
+diff --git a/src/share/vm/prims/jvmtiRedefineClassesTrace.hpp b/src/share/vm/prims/jvmtiRedefineClassesTrace.hpp
+index 878d300..7eb7336 100644
+--- a/src/share/vm/prims/jvmtiRedefineClassesTrace.hpp
++++ b/src/share/vm/prims/jvmtiRedefineClassesTrace.hpp
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2003, 2013, 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
+@@ -22,90 +22,17 @@
+ *
+ */
+
+-#ifndef SHARE_VM_PRIMS_JVMTIREDEFINECLASSESTRACE_HPP
+-#define SHARE_VM_PRIMS_JVMTIREDEFINECLASSESTRACE_HPP
++#define IF_TRACE_RC1 if (TraceRedefineClasses >= 1)
++#define IF_TRACE_RC2 if (TraceRedefineClasses >= 2)
++#define IF_TRACE_RC3 if (TraceRedefineClasses >= 3)
++#define IF_TRACE_RC4 if (TraceRedefineClasses >= 4)
++#define IF_TRACE_RC5 if (TraceRedefineClasses >= 5)
+
+-// RedefineClasses tracing support via the TraceRedefineClasses
+-// option. A bit is assigned to each group of trace messages.
+-// Groups of messages are individually selectable. We have to use
+-// decimal values on the command line since the command option
+-// parsing logic doesn't like non-decimal numerics. The HEX values
+-// are used in the actual RC_TRACE() calls for sanity. To achieve
+-// the old cumulative behavior, pick the level after the one in
+-// which you are interested and subtract one, e.g., 33554431 will
+-// print every tracing message.
+-//
+-// 0x00000000 | 0 - default; no tracing messages
+-// 0x00000001 | 1 - name each target class before loading, after
+-// loading and after redefinition is completed
+-// 0x00000002 | 2 - print info if parsing, linking or
+-// verification throws an exception
+-// 0x00000004 | 4 - print timer info for the VM operation
+-// 0x00000008 | 8 - print subclass counter updates
+-// 0x00000010 | 16 - unused
+-// 0x00000020 | 32 - unused
+-// 0x00000040 | 64 - unused
+-// 0x00000080 | 128 - unused
+-// 0x00000100 | 256 - previous class weak reference addition
+-// 0x00000200 | 512 - previous class weak reference mgmt during
+-// class unloading checks (GC)
+-// 0x00000400 | 1024 - previous class weak reference mgmt during
+-// add previous ops (GC)
+-// 0x00000800 | 2048 - previous class breakpoint mgmt
+-// 0x00001000 | 4096 - detect calls to obsolete methods
+-// 0x00002000 | 8192 - fail a guarantee() in addition to detection
+-// 0x00004000 | 16384 - detect old/obsolete methods in metadata
+-// 0x00008000 | 32768 - old/new method matching/add/delete
+-// 0x00010000 | 65536 - impl details: CP size info
+-// 0x00020000 | 131072 - impl details: CP merge pass info
+-// 0x00040000 | 262144 - impl details: CP index maps
+-// 0x00080000 | 524288 - impl details: modified CP index values
+-// 0x00100000 | 1048576 - impl details: vtable updates
+-// 0x00200000 | 2097152 - impl details: itable updates
+-// 0x00400000 | 4194304 - impl details: constant pool cache updates
+-// 0x00800000 | 8388608 - impl details: methodComparator info
+-// 0x01000000 | 16777216 - impl details: nmethod evolution info
+-// 0x02000000 | 33554432 - impl details: annotation updates
+-// 0x04000000 | 67108864 - impl details: StackMapTable updates
+-// 0x08000000 | 134217728 - impl details: OopMapCache updates
+-// 0x10000000 | 268435456 - unused
+-// 0x20000000 | 536870912 - unused
+-// 0x40000000 | 1073741824 - unused
+-// 0x80000000 | 2147483648 - unused
+-//
+-// Note: The ResourceMark is to cleanup resource allocated args.
+-// The "while (0)" is so we can use semi-colon at end of RC_TRACE().
+-#define RC_TRACE(level, args) \
+- if ((TraceRedefineClasses & level) != 0) { \
+- ResourceMark rm; \
+- tty->print("RedefineClasses-0x%x: ", level); \
+- tty->print_cr args; \
+- } while (0)
+-
+-#define RC_TRACE_NO_CR(level, args) \
+- if ((TraceRedefineClasses & level) != 0) { \
+- ResourceMark rm; \
+- tty->print("RedefineClasses-0x%x: ", level); \
+- tty->print args; \
+- } while (0)
+-
+-#define RC_TRACE_WITH_THREAD(level, thread, args) \
+- if ((TraceRedefineClasses & level) != 0) { \
+- ResourceMark rm(thread); \
+- tty->print("RedefineClasses-0x%x: ", level); \
+- tty->print_cr args; \
+- } while (0)
+-
+-#define RC_TRACE_MESG(args) \
+- { \
+- ResourceMark rm; \
+- tty->print("RedefineClasses: "); \
+- tty->print_cr args; \
+- } while (0)
+-
+-// Macro for checking if TraceRedefineClasses has a specific bit
+-// enabled. Returns true if the bit specified by level is set.
+-#define RC_TRACE_ENABLED(level) ((TraceRedefineClasses & level) != 0)
++#define TRACE_RC1 if (TraceRedefineClasses >= 1) tty->print("TraceRedefineClasses-1: "); if (TraceRedefineClasses >= 1) tty->print_cr
++#define TRACE_RC2 if (TraceRedefineClasses >= 2) tty->print(" TraceRedefineClasses-2: "); if (TraceRedefineClasses >= 2) tty->print_cr
++#define TRACE_RC3 if (TraceRedefineClasses >= 3) tty->print(" TraceRedefineClasses-3: "); if (TraceRedefineClasses >= 3) tty->print_cr
++#define TRACE_RC4 if (TraceRedefineClasses >= 4) tty->print(" TraceRedefineClasses-4: "); if (TraceRedefineClasses >= 4) tty->print_cr
++#define TRACE_RC5 if (TraceRedefineClasses >= 5) tty->print(" TraceRedefineClasses-5: "); if (TraceRedefineClasses >= 5) tty->print_cr
+
+ // Macro for checking if TraceRedefineClasses has one or more bits
+ // set in a range of bit values. Returns true if one or more bits
+@@ -124,12 +51,10 @@
+ // is enabled. The "while (0)" is so we can use semi-colon at end of
+ // the macro.
+ #define RC_TIMER_START(t) \
+- if (RC_TRACE_ENABLED(0x00000004)) { \
++ if (TimeRedefineClasses) { \
+ t.start(); \
+ } while (0)
+ #define RC_TIMER_STOP(t) \
+- if (RC_TRACE_ENABLED(0x00000004)) { \
++ if (TimeRedefineClasses) { \
+ t.stop(); \
+ } while (0)
+-
+-#endif // SHARE_VM_PRIMS_JVMTIREDEFINECLASSESTRACE_HPP
+diff --git a/src/share/vm/prims/methodComparator.cpp b/src/share/vm/prims/methodComparator.cpp
+index 60eaf97..785dc24 100644
+--- a/src/share/vm/prims/methodComparator.cpp
++++ b/src/share/vm/prims/methodComparator.cpp
+@@ -42,10 +42,9 @@
+ if (old_method->code_size() != new_method->code_size())
+ return false;
+ if (check_stack_and_locals_size(old_method, new_method) != 0) {
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
++ TRACE_RC4("Methods %s non-comparable with diagnosis %d",
+ old_method->name()->as_C_string(),
+- check_stack_and_locals_size(old_method, new_method)));
++ check_stack_and_locals_size(old_method, new_method));
+ return false;
+ }
+
+@@ -114,10 +113,9 @@
+ // Now we can test all forward jumps
+ for (int i = 0; i < fwd_jmps.length() / 2; i++) {
+ if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
+- RC_TRACE(0x00800000,
+- ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
++ TRACE_RC4("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
+ fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
+- fwd_jmps.at(i*2+1)));
++ fwd_jmps.at(i*2+1));
+ return false;
+ }
+ }
+diff --git a/src/share/vm/prims/methodHandles.cpp b/src/share/vm/prims/methodHandles.cpp
+index 928bce1..b268fec 100644
+--- a/src/share/vm/prims/methodHandles.cpp
++++ b/src/share/vm/prims/methodHandles.cpp
+@@ -1004,25 +1004,6 @@
+ }
+
+
+-// It is called at safepoint only for RedefineClasses
+-void MemberNameTable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+- int methods_length, bool *trace_name_printed) {
+- assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
+- // For each redefined method
+- for (int j = 0; j < methods_length; j++) {
+- methodOop old_method = old_methods[j];
+- methodOop new_method = new_methods[j];
+- // search the MemberNameTable for uses of either obsolete or EMCP methods
+- for (int idx = 0; idx < length(); idx++) {
+- oop mem_name = JNIHandles::resolve(this->at(idx));
+- if (mem_name != NULL) {
+- java_lang_invoke_MemberName::adjust_vmtarget(mem_name, old_method, new_method,
+- trace_name_printed);
+- }
+- }
+- }
+-}
+-
+ //
+ // Here are the native methods in java.lang.invoke.MethodHandleNatives
+ // They are the private interface between this JVM and the HotSpot-specific
+diff --git a/src/share/vm/prims/methodHandles.hpp b/src/share/vm/prims/methodHandles.hpp
+index 2688b94..0be2330 100644
+--- a/src/share/vm/prims/methodHandles.hpp
++++ b/src/share/vm/prims/methodHandles.hpp
+@@ -240,12 +240,6 @@
+
+ void add_member_name(jweak mem_name_ref);
+
+- public:
+- // RedefineClasses() API support:
+- // If a MemberName refers to old_method then update it
+- // to refer to new_method.
+- void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+- int methods_length, bool *trace_name_printed);
+ };
+
+ #endif // SHARE_VM_PRIMS_METHODHANDLES_HPP
+diff --git a/src/share/vm/runtime/arguments.cpp b/src/share/vm/runtime/arguments.cpp
+index 36aebb4..60020ed 100644
+--- a/src/share/vm/runtime/arguments.cpp
++++ b/src/share/vm/runtime/arguments.cpp
+@@ -54,8 +54,8 @@
+ #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp"
+ #endif
+
+-// Note: This is a special bug reporting site for the JVM
+-#define DEFAULT_VENDOR_URL_BUG "http://bugreport.java.com/bugreport/crash.jsp"
++// (tw) The DCE VM has its own JIRA bug tracking system.
++#define DEFAULT_VENDOR_URL_BUG "http://ssw.jku.at/dcevm/bugreport/"
+ #define DEFAULT_JAVA_LAUNCHER "generic"
+
+ char** Arguments::_jvm_flags_array = NULL;
+@@ -1875,6 +1875,16 @@
+ status = false;
+ }
+
++ // (tw) Must use serial GC. This limitation applies because the instance size changing GC modifications
++ // are only built into the mark and compact algorithm.
++ 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;
+ }
+
+@@ -3464,7 +3474,7 @@
+
+ // Set flags if Aggressive optimization flags (-XX:+AggressiveOpts) enabled.
+ set_aggressive_opts_flags();
+-
++#ifndef COMPILER2
+ // Turn off biased locking for locking debug mode flags,
+ // which are subtlely different from each other but neither works with
+ // biased locking.
+@@ -3481,6 +3491,7 @@
+ }
+ UseBiasedLocking = false;
+ }
++#endif
+
+ #ifdef CC_INTERP
+ // Clear flags not supported by the C++ interpreter
+diff --git a/src/share/vm/runtime/fieldDescriptor.cpp b/src/share/vm/runtime/fieldDescriptor.cpp
+index 3d5213f..9cc701b 100644
+--- a/src/share/vm/runtime/fieldDescriptor.cpp
++++ b/src/share/vm/runtime/fieldDescriptor.cpp
+@@ -92,7 +92,8 @@
+ instanceKlass* ik = instanceKlass::cast(k);
+ _cp = ik->constants();
+ FieldInfo* f = ik->field(index);
+- assert(!f->is_internal(), "regular Java fields only");
++ // (tw) do we need this?
++// assert(!f->is_internal(), "regular Java fields only");
+
+ _access_flags = accessFlags_from(f->access_flags());
+ guarantee(f->name_index() != 0 && f->signature_index() != 0, "bad constant pool index for fieldDescriptor");
+diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
+index 7ec105c..bb68b23 100644
+--- a/src/share/vm/runtime/globals.hpp
++++ b/src/share/vm/runtime/globals.hpp
+@@ -1235,6 +1235,11 @@
+ 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 @@
+ 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 @@
+ 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 @@
+ }
+
+ 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 @@
+ // 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 @@
+ // 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 @@
+ // 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 @@
+ 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..1b583ff 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;
+@@ -283,6 +284,7 @@
+ 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..f839f46 100644
+--- a/src/share/vm/runtime/mutexLocker.hpp
++++ b/src/share/vm/runtime/mutexLocker.hpp
+@@ -43,6 +43,7 @@
+ // Mutexes used in the VM.
+
+ extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
++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 @@
+ // 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 @@
+ 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 @@
+ // 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..689b9a2 100644
+--- a/src/share/vm/runtime/sharedRuntime.cpp
++++ b/src/share/vm/runtime/sharedRuntime.cpp
+@@ -603,21 +603,13 @@
+ //
+ JRT_LEAF(int, SharedRuntime::rc_trace_method_entry(
+ JavaThread* thread, methodOopDesc* method))
+- assert(RC_TRACE_IN_RANGE(0x00001000, 0x00002000), "wrong call");
++ assert(TraceRedefineClasses >= 4, "wrong call");
+
+ if (method->is_obsolete()) {
+ // We are calling an obsolete method, but this is not necessarily
+ // an error. Our method could have been redefined just after we
+ // fetched the methodOop from the constant pool.
+-
+- // RC_TRACE macro has an embedded ResourceMark
+- RC_TRACE_WITH_THREAD(0x00001000, thread,
+- ("calling obsolete method '%s'",
+- method->name_and_sig_as_C_string()));
+- if (RC_TRACE_ENABLED(0x00002000)) {
+- // this option is provided to debug calls to obsolete methods
+- guarantee(false, "faulting at call to an obsolete method.");
+- }
++ TRACE_RC4("calling obsolete method '%s'", method->name_and_sig_as_C_string());
+ }
+ return 0;
+ JRT_END
+@@ -1137,7 +1129,20 @@
+ 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()->super() != NULL) {
++
++ // (tw) 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 c8644d0..5f42114 100644
+--- a/src/share/vm/runtime/thread.cpp
++++ b/src/share/vm/runtime/thread.cpp
+@@ -216,6 +216,8 @@
+ 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 @@
+ omFreeProvision = 32 ;
+ omInUseList = NULL ;
+ omInUseCount = 0 ;
++ _pretend_new_universe = false;
+
+ #ifdef ASSERT
+ _visited_for_critical_count = false;
+@@ -880,6 +883,15 @@
+ bool Thread::owns_locks_but_compiled_lock() const {
+ for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
+ if (cur != Compile_lock) return true;
++ }
++ 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;
+ }
+@@ -1637,7 +1649,7 @@
+ 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 @@
+
+ // 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 @@
+ _counters = counters;
+ _buffer_blob = NULL;
+ _scanned_nmethod = NULL;
++ _compilation_mutex = new Mutex(Mutex::redefine_classes, "compilationMutex", false);
+
+ #ifndef PRODUCT
+ _ideal_graph_printer = NULL;
+diff --git a/src/share/vm/runtime/thread.hpp b/src/share/vm/runtime/thread.hpp
+index 774bd27..4620820 100644
+--- a/src/share/vm/runtime/thread.hpp
++++ b/src/share/vm/runtime/thread.hpp
+@@ -202,11 +202,14 @@
+ public:
+ 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; }
++ 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 @@
+ 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 @@
+ 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 @@
+ 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 @@
+
+ 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; }
+diff --git a/src/share/vm/runtime/vmThread.cpp b/src/share/vm/runtime/vmThread.cpp
+index 0a3e0da..3c0b0e0 100644
+--- a/src/share/vm/runtime/vmThread.cpp
++++ b/src/share/vm/runtime/vmThread.cpp
+@@ -694,6 +694,9 @@
+ void VMThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+ Thread::oops_do(f, cf);
+ _vm_queue->oops_do(f);
++ 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..18e324b 100644
+--- a/src/share/vm/utilities/exceptions.cpp
++++ b/src/share/vm/utilities/exceptions.cpp
+@@ -254,6 +254,8 @@
+ 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 @@
+ 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 @@
+ 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 {
projects / dcevm.git / commitdiff