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/*
* Copyright (c) 2005, 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 6337571
* @summary Test if findDeadlockedThreads works for an ownable synchronizer
* in shared mode which has no owner when a thread is parked.
* @author Mandy Chung
*
* @run main/othervm SharedSynchronizer
*/
import java.util.concurrent.*;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;
public class SharedSynchronizer {
public static void main(String[] args) throws Exception {
MyThread t = new MyThread();
t.setDaemon(true);
t.start();
ThreadMXBean tmbean = ManagementFactory.getThreadMXBean();
if (!tmbean.isSynchronizerUsageSupported()) {
System.out.println("Monitoring of synchronizer usage not supported")
;
return;
}
long[] result = tmbean.findDeadlockedThreads();
if (result != null) {
throw new RuntimeException("TEST FAILED: result should be null");
}
}
static class MyThread extends Thread {
public void run() {
FutureTask f = new FutureTask(
new Callable() {
public Object call() {
throw new RuntimeException("should never reach here");
}
}
);
// A FutureTask uses the AbstractOwnableSynchronizer in a shared
// mode (not exclusive mode). When the thread calls f.get(),
// it will put to park on the ownable synchronizer that
// is not owned by any thread.
try {
f.get();
} catch (Exception e) {
RuntimeException re = new RuntimeException(e.getMessage());
re.initCause(e);
throw re;
}
}
}
}
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