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view test/compiler/testlibrary/rtm/BusyLock.java @ 19492:5a91549293df
Truffle/Instrumentation: placate FindBugs
author | Michael Van De Vanter <michael.van.de.vanter@oracle.com> |
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date | Wed, 18 Feb 2015 20:38:04 -0800 |
parents | 665bbe93823f |
children |
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/* * Copyright (c) 2014, 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. * */ package rtm; import com.oracle.java.testlibrary.Utils; import sun.misc.Unsafe; import java.util.concurrent.BrokenBarrierException; import java.util.concurrent.CyclicBarrier; /** * Test case for busy lock scenario. * One thread enters the monitor and sleep for a while. * Another thread is blocked on the same monitor. */ public class BusyLock implements CompilableTest, Runnable { private static final int DEFAULT_TIMEOUT = 1000; private final CyclicBarrier barrier; // Following field have to be static in order to avoid escape analysis. @SuppressWarnings("UnsuedDeclaration") private static int field = 0; private static final Unsafe UNSAFE = Utils.getUnsafe(); protected final Object monitor; protected final int timeout; public BusyLock() { this(BusyLock.DEFAULT_TIMEOUT); } public BusyLock(int timeout) { this.timeout = timeout; this.monitor = new Object(); this.barrier = new CyclicBarrier(2); } @Override public void run() { try { // wait until forceAbort leave monitor barrier.await(); if (UNSAFE.tryMonitorEnter(monitor)) { try { barrier.await(); Thread.sleep(timeout); } finally { UNSAFE.monitorExit(monitor); } } else { throw new RuntimeException("Monitor should be entered by " + "::run() first."); } } catch (InterruptedException | BrokenBarrierException e) { throw new RuntimeException("Synchronization error happened.", e); } } public void test() { try { barrier.await(); // wait until monitor is locked by a ::run method barrier.await(); } catch (InterruptedException | BrokenBarrierException e) { throw new RuntimeException("Synchronization error happened.", e); } synchronized(monitor) { BusyLock.field++; } } @Override public String getMethodWithLockName() { return this.getClass().getName() + "::test"; } @Override public String[] getMethodsToCompileNames() { return new String[] { getMethodWithLockName() }; } /** * Usage: * BusyLock [ <inflate monitor> [ <timeout> ] ] * * Default values are: * <ul> * <li>inflate monitor = {@code true}</li> * <li>timeout = {@code BusyLock.DEFAULT_TIMEOUT}</li> * </ul> */ public static void main(String args[]) throws Exception { int timeoutValue = BusyLock.DEFAULT_TIMEOUT; boolean inflateMonitor = true; if (args.length > 0 ) { inflateMonitor = Boolean.valueOf(args[0]); if (args.length > 1) { timeoutValue = Integer.valueOf(args[1]); } } BusyLock busyLock = new BusyLock(timeoutValue); if (inflateMonitor) { AbortProvoker.inflateMonitor(busyLock.monitor); } Thread t = new Thread(busyLock); t.start(); busyLock.test(); t.join(); } }