1 /*
   2  * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 6318638 6325166 6330307
  27  * @summary CopyOnWriteArrayList.equals should be thread-safe
  28  * @author Martin Buchholz
  29  */
  30 
  31 import java.util.*;
  32 import java.util.concurrent.*;
  33 
  34 public class EqualsRace {
  35     private static void realMain(String[] args) throws Throwable {
  36         final int iterations = 100000;
  37         final List<Integer> list = new CopyOnWriteArrayList<Integer>();
  38         final Integer one = Integer.valueOf(1);
  39         final List<Integer> oneElementList = Arrays.asList(one);
  40         final Thread t = new CheckedThread() { public void realRun() {
  41             for (int i = 0; i < iterations; i++) {
  42                 list.add(one);
  43                 list.remove(one);
  44             }}};
  45         t.start();
  46 
  47         for (int i = 0; i < iterations; i++) {
  48             list.equals(oneElementList);
  49             list.equals(Collections.EMPTY_LIST);
  50         }
  51         t.join();
  52         check(list.size() == 0);
  53     }
  54 
  55     //--------------------- Infrastructure ---------------------------
  56     static volatile int passed = 0, failed = 0;
  57     static void pass() {passed++;}
  58     static void fail() {failed++; Thread.dumpStack();}
  59     static void fail(String msg) {System.out.println(msg); fail();}
  60     static void unexpected(Throwable t) {failed++; t.printStackTrace();}
  61     static void check(boolean cond) {if (cond) pass(); else fail();}
  62     static void equal(Object x, Object y) {
  63         if (x == null ? y == null : x.equals(y)) pass();
  64         else fail(x + " not equal to " + y);}
  65     public static void main(String[] args) throws Throwable {
  66         try {realMain(args);} catch (Throwable t) {unexpected(t);}
  67         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
  68         if (failed > 0) throw new AssertionError("Some tests failed");}
  69     private abstract static class CheckedThread extends Thread {
  70         public abstract void realRun() throws Throwable;
  71         public void run() {
  72             try { realRun(); } catch (Throwable t) { unexpected(t); }}}
  73 }