1 /* 2 * Copyright (c) 2005, 2015, 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 /* 26 * @test 27 * @bug 5086470 28 * @key intermittent 29 * @summary Basic Test for the following methods: 30 * - ThreadMXBean.findDeadlockedThreads() 31 * - ThreadMXBean.findMonitorDeadlockedThreads() 32 * @author Mandy Chung 33 * 34 * @modules java.management 35 * @build MonitorDeadlock 36 * @build SynchronizerDeadlock 37 * @build ThreadDump 38 * @run main/othervm FindDeadlocks 39 */ 40 41 import java.lang.management.*; 42 import java.util.*; 43 44 public class FindDeadlocks { 45 static ThreadMXBean mbean = ManagementFactory.getThreadMXBean(); 46 public static void main(String[] argv) { 47 ThreadMXBean mbean = ManagementFactory.getThreadMXBean(); 48 // create deadlocked threads 49 MonitorDeadlock md = new MonitorDeadlock(); 50 51 // no deadlock 52 if (findDeadlocks() != null) { 53 throw new RuntimeException("TEST FAILED: Should return null."); 54 } 55 56 // Let the threads to proceed 57 md.goDeadlock(); 58 // wait until the deadlock is ready 59 md.waitUntilDeadlock(); 60 61 long[] mthreads = findDeadlocks(); 62 if (mthreads == null) { 63 ThreadDump.dumpStacks(); 64 throw new RuntimeException("TEST FAILED: Deadlock not detected."); 65 } 66 md.checkResult(mthreads); 67 68 // create deadlocked threads on synchronizers 69 SynchronizerDeadlock sd = new SynchronizerDeadlock(); 70 71 // Let the threads to proceed 72 sd.goDeadlock(); 73 // wait until the deadlock is ready 74 sd.waitUntilDeadlock(); 75 76 // Find Deadlock 77 long[] threads = findDeadlocks(); 78 if (threads == null) { 79 ThreadDump.dumpStacks(); 80 throw new RuntimeException("TEST FAILED: Deadlock not detected."); 81 } 82 83 // form a list of newly deadlocked threads 84 long[] newList = new long[threads.length - mthreads.length]; 85 int count = 0; 86 for (int i = 0; i < threads.length; i++) { 87 long id = threads[i]; 88 boolean isNew = true; 89 for (int j = 0; j < mthreads.length; j++) { 90 if (mthreads[j] == id) { 91 isNew = false; 92 break; 93 } 94 } 95 if (isNew) { 96 newList[count++] = id; 97 } 98 } 99 100 if (mbean.isSynchronizerUsageSupported()) { 101 sd.checkResult(newList); 102 } else { 103 // monitoring of synchronizer usage not supported 104 if (count != 0) { 105 throw new RuntimeException("TEST FAILED: NewList should be empty."); 106 } 107 } 108 109 // Print Deadlock stack trace 110 System.out.println("Found threads that are in deadlock:-"); 111 ThreadInfo[] infos = mbean.getThreadInfo(threads, Integer.MAX_VALUE); 112 for (int i = 0; i < infos.length; i++) { 113 ThreadDump.printThreadInfo(infos[i]); 114 } 115 116 System.out.println("Test passed"); 117 } 118 static long[] findDeadlocks() { 119 long[] threads; 120 if (mbean.isSynchronizerUsageSupported()) { 121 threads = mbean.findDeadlockedThreads(); 122 } else { 123 threads = mbean.findMonitorDeadlockedThreads(); 124 } 125 return threads; 126 } 127 128 }