1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/test/serviceability/threads/TestFalseDeadLock.java Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,95 @@
1.4 +/*
1.5 + * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + */
1.26 +
1.27 +import java.lang.management.ManagementFactory;
1.28 +import java.lang.management.ThreadMXBean;
1.29 +import java.util.Random;
1.30 +
1.31 +/*
1.32 + * @test
1.33 + * @bug 8016304
1.34 + * @summary Make sure no deadlock is reported for this program which has no deadlocks.
1.35 + * @run main/othervm TestFalseDeadLock
1.36 + */
1.37 +
1.38 +/*
1.39 + * This test will not provoke the bug every time it is run since the bug is intermittent.
1.40 + * The test has a fixed running time of 5 seconds.
1.41 + */
1.42 +
1.43 +public class TestFalseDeadLock {
1.44 + private static ThreadMXBean bean;
1.45 + private static volatile boolean running = true;
1.46 + private static volatile boolean found = false;
1.47 +
1.48 + public static void main(String[] args) throws Exception {
1.49 + bean = ManagementFactory.getThreadMXBean();
1.50 + Thread[] threads = new Thread[500];
1.51 + for (int i = 0; i < threads.length; i++) {
1.52 + Test t = new Test();
1.53 + threads[i] = new Thread(t);
1.54 + threads[i].start();
1.55 + }
1.56 + try {
1.57 + Thread.sleep(5000);
1.58 + } catch (InterruptedException ex) {
1.59 + }
1.60 + running = false;
1.61 + for (Thread t : threads) {
1.62 + t.join();
1.63 + }
1.64 + if (found) {
1.65 + throw new Exception("Deadlock reported, but there is no deadlock.");
1.66 + }
1.67 + }
1.68 +
1.69 + public static class Test implements Runnable {
1.70 + public void run() {
1.71 + Random r = new Random();
1.72 + while (running) {
1.73 + try {
1.74 + synchronized (this) {
1.75 + wait(r.nextInt(1000) + 1);
1.76 + }
1.77 + } catch (InterruptedException ex) {
1.78 + }
1.79 + recurse(2000);
1.80 + }
1.81 + if (bean.findDeadlockedThreads() != null) {
1.82 + System.out.println("FOUND!");
1.83 + found = true;
1.84 + }
1.85 + }
1.86 +
1.87 + private void recurse(int i) {
1.88 + if (!running) {
1.89 + // It is important for the test to call println here
1.90 + // since there are locks inside that path.
1.91 + System.out.println("Hullo");
1.92 + }
1.93 + else if (i > 0) {
1.94 + recurse(i - 1);
1.95 + }
1.96 + }
1.97 + }
1.98 +}
