1 /* 2 * Copyright (c) 2003, 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 * @test 26 * @bug 4892507 27 * @summary Basic Test for the following reset methods: 28 * - ThreadMXBean.findMonitorDeadlockedThreads() 29 * @author Mandy Chung 30 * 31 * @build MonitorDeadlock 32 * @build ThreadDump 33 * @run main/othervm FindMonitorDeadlock 34 */ 35 36 import java.lang.management.*; 37 import java.util.*; 38 39 public class FindMonitorDeadlock { 40 public static void main(String[] argv) { 41 // create deadlocked threads 42 MonitorDeadlock md = new MonitorDeadlock(); 43 44 // No deadlock 45 ThreadMXBean mbean = ManagementFactory.getThreadMXBean(); 46 long[] threads = mbean.findMonitorDeadlockedThreads(); 47 if (threads != null) { 48 throw new RuntimeException("TEST FAILED: Should return null."); 49 } 50 51 // Let the threads to proceed 52 md.goDeadlock(); 53 54 // wait until the deadlock is ready 55 md.waitUntilDeadlock(); 56 57 // Find Deadlock 58 threads = mbean.findMonitorDeadlockedThreads(); 59 if (threads == null) { 60 ThreadDump.dumpStacks(); 61 throw new RuntimeException("TEST FAILED: Deadlock not detected."); 62 } 63 64 // Print Deadlock stack trace 65 System.out.println("Found threads that are in deadlock:-"); 66 ThreadInfo[] infos = mbean.getThreadInfo(threads, Integer.MAX_VALUE); 67 for (int i = 0; i < infos.length; i++) { 68 ThreadDump.printThreadInfo(infos[i]); 69 } 70 71 md.checkResult(threads); 72 System.out.println("Test passed"); 73 } 74 }