156 lines
4.7 KiB
Java
156 lines
4.7 KiB
Java
/*
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* Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* @test
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* @bug 6331746
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* @summary Test a deadlock and will be blocked forever if the deadlock is present.
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* @author Shanliang JIANG
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*
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* @run main DeadlockTest
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*/
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import javax.management.*;
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import javax.management.timer.*;
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public class DeadlockTest extends StandardMBean {
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public <T> DeadlockTest(T implementation, Class<T> mbeanInterface)
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throws NotCompliantMBeanException {
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super(implementation, mbeanInterface);
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}
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public MBeanInfo getCachedMBeanInfo() {
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return super.getCachedMBeanInfo();
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}
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public void cacheMBeanInfo(MBeanInfo mi) {
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super.cacheMBeanInfo(mi);
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}
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public static void main(String[] args) throws Exception {
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System.out.println("main: No deadlock please.");
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System.out.println("main: Create a BadBay to hold the lock forever.");
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DeadlockTest dt = new DeadlockTest(new Timer(), TimerMBean.class);
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BadBoy bb = new BadBoy(dt);
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bb.start();
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synchronized(bb) {
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while(!bb.gotLock) {
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bb.wait(); // if blocked here, means failing to get lock, impossible.
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}
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}
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System.out.println("main: The BadBay is holding the lock forever.");
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System.out.println("main: Create a WorkingBoy to see blocking ...");
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WorkingBoy wb = new WorkingBoy(dt);
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synchronized(wb) {
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wb.start();
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while(!wb.done) {
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wb.wait(); // if blocked here, the deadlock happends
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}
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}
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System.out.println("main: OK, bye bye.");
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}
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private static class BadBoy extends Thread {
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public BadBoy(Object o) {
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setDaemon(true);
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this.o = o;
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}
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public void run() {
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System.out.println("BadBoy-run: keep synchronization lock forever!");
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synchronized(o) {
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synchronized(this) {
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gotLock = true;
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this.notify();
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}
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try {
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Thread.sleep(10000000);
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} catch (Exception e) {
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// OK
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}
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}
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}
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final Object o;
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public boolean gotLock;
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}
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private static class WorkingBoy extends Thread {
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public WorkingBoy(DeadlockTest sm) {
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setDaemon(true);
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this.sm = sm;
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}
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public void run() {
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try {
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System.out.println("WorkingBoy-run: calling StandardMBean methods ...");
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System.out.println("WorkingBoy-run: calling setImplementation ...");
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sm.setImplementation(new Timer());
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System.out.println("WorkingBoy-run: calling getImplementation ...");
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sm.getImplementation();
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System.out.println("WorkingBoy-run: calling getMBeanInterface ...");
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sm.getMBeanInterface();
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System.out.println("WorkingBoy-run: calling getImplementationClass ...");
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sm.getImplementationClass();
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System.out.println("WorkingBoy-run: calling cacheMBeanInfo ...");
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sm.cacheMBeanInfo(null);
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System.out.println("WorkingBoy-run: calling getCachedMBeanInfo ...");
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sm.getCachedMBeanInfo();
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System.out.println("WorkingBoy-run: All done!");
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synchronized(this) {
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done = true;
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this.notifyAll();
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}
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} catch (NotCompliantMBeanException ne) {
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// Impossible?
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throw new RuntimeException(ne);
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}
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}
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final DeadlockTest sm;
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public boolean done;
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}
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}
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