/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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*/
/*
* @test
* @bug 4757273
* @summary Test deadlock in MBeanServerDelegate listeners
* @author Eamonn McManus
* @run clean NotifDeadlockTest
* @run build NotifDeadlockTest
* @run main NotifDeadlockTest
*/
/*
* Test deadlock when a listener for an MBeanServerDelegate does a
* register or unregister of an MBean. Since such a listener is
* triggered by a register or unregister operation, deadlock scenarios
* are possible if there are any locks held while the listener is
* being dispatched.
*
* The flow of control looks rather like this:
*
* Thread 1:
* - MBeanServer.createMBean(..., objectName1);
* --- MBeanServerDelegate.sendNotification
* ----- XListener.handleNotification
* ------- create Thread 2
* ------- wait for Thread 2 to complete
*
* Thread 2:
* - MBeanServer.createMBean(..., objectName2);
* - end Thread 2
*
* If any locks are held by Thread 1 within createMBean or
* sendNotification, then Thread 2 can block waiting for them.
* Since Thread 1 is itself waiting for Thread 2, this is a deadlock.
*
* We test all four combinations of:
* (Thread1-create,Thread1-unregister) x (Thread2-create,Thread2-unregister)
*
* In the JMX 1.1 RI, all four tests fail. In the JMX 1.2 RI, all four
* tests should pass.
*/
import javax.management.*;
public class NotifDeadlockTest {
static {
try {
delName =
new ObjectName("JMImplementation:type=MBeanServerDelegate");
} catch (MalformedObjectNameException e) {
throw new Error();
}
}
static boolean timedOut;
/* This listener registers or unregisters the MBean called on2
when triggered. */
private boolean firstTime = true;
private final boolean register;
}
if (firstTime) {
firstTime = false;
public void run() {
try {
if (register) {
on2);
} else {
}
} catch (Exception e) {
e.printStackTrace();
}
}
};
t.start();
try {
t.join(2000);
} catch (InterruptedException e) {
e.printStackTrace(); // should not happen
}
if (t.isAlive()) {
"probable deadlock");
timedOut = true;
}
}
}
}
boolean success = true;
timedOut = false;
if (timedOut) {
success = false;
// wait for the spawned thread to complete its work, probably
}
timedOut = false;
if (timedOut) {
success = false;
// wait for the spawned thread to complete its work, probably
}
timedOut = false;
if (timedOut) {
success = false;
// wait for the spawned thread to complete its work, probably
}
timedOut = false;
if (timedOut) {
success = false;
// wait for the spawned thread to complete its work, probably
}
if (success)
else {
}
}
}