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 6330307 6355645
  27  * @summary Check for race conditions in COWArray classes
  28  * @author Martin Buchholz
  29  */
  30 
  31 import java.util.*;
  32 import java.util.concurrent.*;
  33 
  34 public class RacingCows {
  35     private static void realMain(String[] args) throws Throwable {
  36         final int iterations = 100000;
  37         final Integer two = Integer.valueOf(2);
  38         final Integer three = Integer.valueOf(3);
  39 
  40         //------------ CopyOnWriteArraySet -------------------------------
  41         final Set<Integer> s1 = new CopyOnWriteArraySet<Integer>();
  42         final Set<Integer> s2 = new CopyOnWriteArraySet<Integer>();
  43         s1.add(1);
  44 
  45         final Thread t1 = new CheckedThread() { public void realRun() {
  46             for (int i = 0; i < iterations; i++) {
  47                 s2.add(two);
  48                 s2.remove(two);
  49             }}};
  50         t1.start();
  51 
  52         for (int i = 0; i < iterations; i++) {
  53             check(! s1.equals(s2));
  54             check(! s2.equals(s1));
  55         }
  56         t1.join();
  57 
  58         //------------ CopyOnWriteArrayList ------------------------------
  59         final List<Integer> l1 = new CopyOnWriteArrayList<Integer>();
  60         final List<Integer> l2 = new CopyOnWriteArrayList<Integer>();
  61         final List<Integer> l3 = new CopyOnWriteArrayList<Integer>();
  62         l1.add(1);
  63 
  64         final Thread t2 = new CheckedThread() { public void realRun() {
  65             for (int i = 0; i < iterations; i++) {
  66                 switch (i%2) {
  67                 case 0: l2.add(two);    break;
  68                 case 1: l2.add(0, two); break;
  69                 }
  70                 switch (i%3) {
  71                 case 0: l2.remove(two); break;
  72                 case 1: l2.remove(0);   break;
  73                 case 2: l2.clear();     break;
  74                 }}}};
  75         t2.start();
  76 
  77         final Thread t3 = new CheckedThread() { public void realRun() {
  78             l3.add(three);
  79             for (int i = 0; i < iterations; i++) {
  80                 switch (i%2) {
  81                 case 0: l3.add(two);    break;
  82                 case 1: l3.add(0, two); break;
  83                 }
  84                 switch (i%2) {
  85                 case 0: l3.remove(two); break;
  86                 case 1: l3.remove(0);   break;
  87                 }}}};
  88         t3.start();
  89 
  90         for (int i = 0; i < iterations; i++) {
  91             check(! l1.equals(l2));
  92             check(! l2.equals(l1));
  93 
  94             // CopyOnWriteArrayList(mutatingCollection)
  95             try { new CopyOnWriteArrayList<Integer>(l2); }
  96             catch (Throwable t) { unexpected(t); }
  97 
  98             // addAllAbsent(mutatingCollection)
  99             try { new CopyOnWriteArrayList<Integer>().addAllAbsent(l3); }
 100             catch (Throwable t) { unexpected(t); }
 101 
 102             // addAll(mutatingCollection)
 103             try { new CopyOnWriteArrayList<Integer>().addAll(l3); }
 104             catch (Throwable t) { unexpected(t); }
 105 
 106             // addAll(int, mutatingCollection)
 107             try { new CopyOnWriteArrayList<Integer>().addAll(0,l3); }
 108             catch (Throwable t) { unexpected(t); }
 109         }
 110         t2.join();
 111         t3.join();
 112     }
 113 
 114     //--------------------- Infrastructure ---------------------------
 115     static volatile int passed = 0, failed = 0;
 116     static void pass() {passed++;}
 117     static void fail() {failed++; Thread.dumpStack();}
 118     static void fail(String msg) {System.out.println(msg); fail();}
 119     static void unexpected(Throwable t) {failed++; t.printStackTrace();}
 120     static void check(boolean cond) {if (cond) pass(); else fail();}
 121     static void equal(Object x, Object y) {
 122         if (x == null ? y == null : x.equals(y)) pass();
 123         else fail(x + " not equal to " + y);}
 124     public static void main(String[] args) throws Throwable {
 125         try {realMain(args);} catch (Throwable t) {unexpected(t);}
 126         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
 127         if (failed > 0) throw new AssertionError("Some tests failed");}
 128     private abstract static class CheckedThread extends Thread {
 129         public abstract void realRun() throws Throwable;
 130         public void run() {
 131             try { realRun(); } catch (Throwable t) { unexpected(t); }}}
 132 }
--- EOF ---