| /* |
| * Copyright (c) 2003, 2015, 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. |
| */ |
| |
| /* |
| * @test |
| * @bug 4530538 |
| * @summary Basic unit test of ThreadInfo.getBlockedCount() |
| * @author Alexei Guibadoulline and Mandy Chung |
| * @author Jaroslav Bachorik |
| * @modules java.management |
| * @run main ThreadBlockedCount |
| */ |
| |
| import java.lang.management.*; |
| import java.util.concurrent.Phaser; |
| |
| public class ThreadBlockedCount { |
| static final long EXPECTED_BLOCKED_COUNT = 3; |
| static final int DEPTH = 10; |
| private static final ThreadMXBean mbean |
| = ManagementFactory.getThreadMXBean(); |
| |
| private static final Object a = new Object(); |
| private static final Object b = new Object(); |
| private static final Object c = new Object(); |
| |
| private static final Object blockedObj1 = new Object(); |
| private static final Object blockedObj2 = new Object(); |
| private static final Object blockedObj3 = new Object(); |
| private static volatile boolean testOk = true; |
| private static BlockingThread blocking; |
| private static BlockedThread blocked; |
| |
| public static void main(String args[]) throws Exception { |
| // real run |
| runTest(); |
| if (!testOk) { |
| throw new RuntimeException("TEST FAILED."); |
| } |
| System.out.println("Test passed."); |
| } |
| |
| private static void runTest() throws Exception { |
| final Phaser p = new Phaser(2); |
| |
| blocking = new BlockingThread(p); |
| blocking.start(); |
| |
| blocked = new BlockedThread(p); |
| blocked.start(); |
| |
| try { |
| blocking.join(); |
| |
| testOk = checkBlocked(); |
| p.arriveAndAwaitAdvance(); // #5 |
| |
| } catch (InterruptedException e) { |
| System.err.println("Unexpected exception."); |
| e.printStackTrace(System.err); |
| throw e; |
| } |
| } |
| |
| |
| static class BlockedThread extends Thread { |
| private final Phaser p; |
| |
| BlockedThread(Phaser p) { |
| super("BlockedThread"); |
| this.p = p; |
| } |
| |
| public void run() { |
| int accumulator = 0; |
| p.arriveAndAwaitAdvance(); // #1 |
| |
| // Enter lock a without blocking |
| synchronized (a) { |
| p.arriveAndAwaitAdvance(); // #2 |
| |
| // Block to enter blockedObj1 |
| // blockedObj1 should be owned by BlockingThread |
| synchronized (blockedObj1) { |
| accumulator++; // filler |
| } |
| } |
| |
| // Enter lock a without blocking |
| synchronized (b) { |
| // wait until BlockingThread holds blockedObj2 |
| p.arriveAndAwaitAdvance(); // #3 |
| |
| // Block to enter blockedObj2 |
| // blockedObj2 should be owned by BlockingThread |
| synchronized (blockedObj2) { |
| accumulator++; // filler |
| } |
| } |
| |
| // Enter lock a without blocking |
| synchronized (c) { |
| // wait until BlockingThread holds blockedObj3 |
| p.arriveAndAwaitAdvance(); // #4 |
| |
| // Block to enter blockedObj3 |
| // blockedObj3 should be owned by BlockingThread |
| synchronized (blockedObj3) { |
| accumulator++; // filler |
| } |
| } |
| |
| // wait for the main thread to check the blocked count |
| System.out.println("Acquired " + accumulator + " monitors"); |
| p.arriveAndAwaitAdvance(); // #5 |
| // ... and we can leave now |
| } // run() |
| } // BlockedThread |
| |
| static class BlockingThread extends Thread { |
| private final Phaser p; |
| |
| BlockingThread(Phaser p) { |
| super("BlockingThread"); |
| this.p = p; |
| } |
| |
| private void waitForBlocked() { |
| // wait for BlockedThread. |
| p.arriveAndAwaitAdvance(); |
| |
| boolean threadBlocked = false; |
| while (!threadBlocked) { |
| // give a chance for BlockedThread to really block |
| try { |
| Thread.sleep(50); |
| } catch (InterruptedException e) { |
| System.err.println("Unexpected exception."); |
| e.printStackTrace(System.err); |
| testOk = false; |
| break; |
| } |
| ThreadInfo info = mbean.getThreadInfo(blocked.getId()); |
| threadBlocked = (info.getThreadState() == Thread.State.BLOCKED); |
| } |
| } |
| |
| public void run() { |
| p.arriveAndAwaitAdvance(); // #1 |
| |
| synchronized (blockedObj1) { |
| System.out.println("BlockingThread attempts to notify a"); |
| waitForBlocked(); // #2 |
| } |
| |
| // block until BlockedThread is ready |
| synchronized (blockedObj2) { |
| System.out.println("BlockingThread attempts to notify b"); |
| waitForBlocked(); // #3 |
| } |
| |
| // block until BlockedThread is ready |
| synchronized (blockedObj3) { |
| System.out.println("BlockingThread attempts to notify c"); |
| waitForBlocked(); // #4 |
| } |
| |
| } // run() |
| } // BlockingThread |
| |
| private static long getBlockedCount() { |
| long count; |
| // Check the mbean now |
| ThreadInfo ti = mbean.getThreadInfo(blocked.getId()); |
| count = ti.getBlockedCount(); |
| return count; |
| } |
| |
| private static boolean checkBlocked() { |
| // wait for the thread stats to be updated for 10 seconds |
| long count = -1; |
| for (int i = 0; i < 100; i++) { |
| count = getBlockedCount(); |
| if (count >= EXPECTED_BLOCKED_COUNT) { |
| return true; |
| } |
| try { |
| Thread.sleep(100); |
| } catch (InterruptedException e) { |
| System.err.println("Unexpected exception."); |
| e.printStackTrace(System.err); |
| return false; |
| } |
| } |
| System.err.println("TEST FAILED: Blocked thread has " + count + |
| " blocked counts. Expected at least " + |
| EXPECTED_BLOCKED_COUNT); |
| return false; |
| } |
| } |