/*
* Copyright 2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* @test
* @bug 6331746
* @summary Deadlock on synchronization problem
* @author Shanliang JIANG
* @run main DeadlockTest
*/
import javax.management.*;
import javax.management.timer.*;
public class DeadlockTest extends StandardMBean {
public <T> DeadlockTest(T implementation, Class<T> mbeanInterface)
throws NotCompliantMBeanException {
super(implementation, mbeanInterface);
}
public MBeanInfo getCachedMBeanInfo() {
return super.getCachedMBeanInfo();
}
public void cacheMBeanInfo(MBeanInfo mi) {
super.cacheMBeanInfo(mi);
}
public static void main(String[] args) throws Exception {
System.out.println("main: No deadlock please.");
System.out.println("main: Create a BadBay to hold the lock forever.");
DeadlockTest dt = new DeadlockTest(new Timer(), TimerMBean.class);
BadBoy bb = new BadBoy(dt);
bb.start();
final long timeout = 2000;
long stopTime = System.currentTimeMillis() + timeout;
long timeToWait = timeout;
synchronized(bb) {
while(!bb.gotLock || timeToWait > 0) {
bb.wait(timeToWait);
timeToWait = stopTime - System.currentTimeMillis();
}
}
if (!bb.gotLock) {
throw new RuntimeException("Failed to get lock, impossible!");
}
System.out.println("main: The BadBay is holding the lock forever.");
System.out.println("main: Create a WorkingBoy to see blocking ...");
WorkingBoy wb = new WorkingBoy(dt);
stopTime = System.currentTimeMillis() + timeout;
timeToWait = timeout;
synchronized(wb) {
wb.start();
while(!wb.done || timeToWait > 0) {
wb.wait(timeToWait);
timeToWait = stopTime - System.currentTimeMillis();
}
}
if (!wb.done) {
throw new RuntimeException("It is blocked!");
}
System.out.println("main: OK, bye bye.");
}
private static class BadBoy extends Thread {
public BadBoy(Object o) {
setDaemon(true);
this.o = o;
}
public void run() {
System.out.println("BadBoy-run: keep synchronization lock forever!");
synchronized(o) {
synchronized(this) {
gotLock = true;
this.notify();
}
try {
Thread.sleep(10000000);
} catch (Exception e) {
// OK
}
}
}
final Object o;
public boolean gotLock;
}
private static class WorkingBoy extends Thread {
public WorkingBoy(DeadlockTest sm) {
setDaemon(true);
this.sm = sm;
}
public void run() {
try {
System.out.println("WorkingBoy-run: calling StandardMBean methods ...");
System.out.println("WorkingBoy-run: calling setImplementation ...");
sm.setImplementation(new Timer());
System.out.println("WorkingBoy-run: calling getImplementation ...");
sm.getImplementation();
System.out.println("WorkingBoy-run: calling getMBeanInterface ...");
sm.getMBeanInterface();
System.out.println("WorkingBoy-run: calling getImplementationClass ...");
sm.getImplementationClass();
System.out.println("WorkingBoy-run: calling cacheMBeanInfo ...");
sm.cacheMBeanInfo(null);
System.out.println("WorkingBoy-run: calling getCachedMBeanInfo ...");
sm.getCachedMBeanInfo();
System.out.println("WorkingBoy-run: All done!");
synchronized(this) {
done = true;
this.notifyAll();
}
} catch (NotCompliantMBeanException ne) {
// Impossible?
throw new RuntimeException(ne);
}
}
final DeadlockTest sm;
public boolean done;
}
}