source.dussan.org Git - aspectj.git/blob

   1 /* *******************************************************************
   2  * Copyright (c) 2004 IBM
   3  * All rights reserved.
   4  * This program and the accompanying materials are made available
   5  * under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     Andy Clement -     initial implementation
  11  * ******************************************************************/
  12
  13 package org.aspectj.apache.bcel.classfile.tests;
  14
  15 import org.aspectj.apache.bcel.classfile.Code;
  16 import org.aspectj.apache.bcel.classfile.JavaClass;
  17 import org.aspectj.apache.bcel.classfile.LocalVariableTable;
  18 import org.aspectj.apache.bcel.classfile.Method;
  19 import org.aspectj.apache.bcel.classfile.tests.BcelTestCase;
  20
  21 import java.util.concurrent.CountDownLatch;
  22 import java.util.concurrent.ExecutorService;
  23 import java.util.concurrent.Executors;
  24 import java.util.concurrent.Semaphore;
  25 import java.util.concurrent.atomic.AtomicReference;
  26
  27
  28 public class LocalVariableTableConcurrencyTest extends BcelTestCase {
  29
  30         private final int nThreads = Runtime.getRuntime().availableProcessors();
  31
  32         private final ExecutorService[] workers = new ExecutorService[nThreads];
  33
  34         private LocalVariableTable reference;
  35
  36         protected void setUp() throws Exception {
  37                 super.setUp();
  38                 for (int i = 0; i < nThreads; i++) workers[i] = Executors.newSingleThreadExecutor();
  39
  40                 JavaClass clazz = getClassFromJar("SimpleGenericsProgram");
  41
  42                 Method mainMethod = getMethod(clazz,"main");
  43                 Code codeAttr = (Code) findAttribute("Code",mainMethod.getAttributes());
  44
  45                 reference =
  46                                 (LocalVariableTable) findAttribute("LocalVariableTable",codeAttr.getAttributes());
  47         }
  48
  49         private LocalVariableTable createReferenceCopy() {
  50                 try {
  51                         return (LocalVariableTable) reference.clone();
  52                 } catch (CloneNotSupportedException e) {
  53                         throw new RuntimeException("Faileed to clone LocalVariableTable", e);
  54                 }
  55         }
  56
  57         public void testLocalVariableTableAttributeConcurrency() throws RuntimeException, InterruptedException {
  58                 final AtomicReference<RuntimeException> error = new AtomicReference<>();
  59                 for (int i = 0; i < 100000; i++) {
  60                         LocalVariableTable sharedInstance = createReferenceCopy();
  61                         CountDownLatch preStart = new CountDownLatch(nThreads);
  62                         Semaphore start = new Semaphore(0);
  63                         CountDownLatch finish = new CountDownLatch(nThreads);
  64
  65                         for (int j = 0; j < nThreads; j++) {
  66                                 final boolean needsDelay = j > 0;
  67                                 workers[j].execute(() -> {
  68                                         preStart.countDown();
  69                                         start.acquireUninterruptibly();
  70                                         // trying to trigger concurrent unpacking - one tread should enter unpack() when other is about to leave it
  71                                         if (needsDelay) createReferenceCopy().getTableLength();
  72                                         try {
  73                                                 sharedInstance.getTableLength();
  74                                         }
  75                                         catch (RuntimeException ex) {
  76                                                 error.compareAndSet(null, ex);
  77                                         }
  78                                         finish.countDown();
  79                                 });
  80                         }
  81
  82                         preStart.await();
  83                         start.release(nThreads);
  84                         finish.await();
  85
  86                         if (error.get() != null) throw error.get();
  87                 }
  88         }
  89
  90         protected void tearDown() throws Exception {
  91                 for (int i = 0; i < nThreads; i++) if (workers[i] != null) workers[i].shutdownNow();
  92                 super.tearDown();
  93         }
  94 }