| /* |
| * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| import jdk.test.lib.Utils; |
| import java.lang.management.ManagementFactory; |
| import java.lang.management.ThreadMXBean; |
| import java.util.Random; |
| |
| /* |
| * @test |
| * @bug 8016304 |
| * @summary Make sure no deadlock is reported for this program which has no deadlocks. |
| * @modules java.base/jdk.internal.misc |
| * @library /test/lib |
| * @run main/othervm TestFalseDeadLock |
| */ |
| |
| /* |
| * This test will not provoke the bug every time it is run since the bug is intermittent. |
| * The test has a fixed running time of 5 seconds. |
| */ |
| |
| public class TestFalseDeadLock { |
| private static ThreadMXBean bean; |
| private static volatile boolean running = true; |
| private static volatile boolean found = false; |
| |
| public static void main(String[] args) throws Exception { |
| bean = ManagementFactory.getThreadMXBean(); |
| Thread[] threads = new Thread[500]; |
| for (int i = 0; i < threads.length; i++) { |
| Test t = new Test(); |
| threads[i] = new Thread(t); |
| threads[i].start(); |
| } |
| try { |
| Thread.sleep(5000); |
| } catch (InterruptedException ex) { |
| } |
| running = false; |
| for (Thread t : threads) { |
| t.join(); |
| } |
| if (found) { |
| throw new Exception("Deadlock reported, but there is no deadlock."); |
| } |
| } |
| |
| public static class Test implements Runnable { |
| public void run() { |
| Random r = Utils.getRandomInstance(); |
| while (running) { |
| try { |
| synchronized (this) { |
| wait(r.nextInt(1000) + 1); |
| } |
| } catch (InterruptedException ex) { |
| } |
| recurse(2000); |
| } |
| if (bean.findDeadlockedThreads() != null) { |
| System.out.println("FOUND!"); |
| found = true; |
| } |
| } |
| |
| private void recurse(int i) { |
| if (!running) { |
| // It is important for the test to call println here |
| // since there are locks inside that path. |
| System.out.println("Hullo"); |
| } |
| else if (i > 0) { |
| recurse(i - 1); |
| } |
| } |
| } |
| } |