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/*
* Copyright (c) 2004, 2024, 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 6199899
* @summary Tests reconnection done by a fetching notif thread.
* @author Shanliang JIANG
* @requires vm.compMode != "Xcomp"
* @comment Running with -Xcomp is likely to cause a timeout from ServerCommunicatorAdmin
* before addNotificationListener can complete.
*
* @run clean NotifReconnectDeadlockTest
* @run build NotifReconnectDeadlockTest
* @run main NotifReconnectDeadlockTest
*/
import java.util.HashMap;
import java.util.Map;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.Notification;
import javax.management.NotificationBroadcasterSupport;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.remote.JMXConnectionNotification;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXConnectorServer;
import javax.management.remote.JMXConnectorServerFactory;
import javax.management.remote.JMXServiceURL;
/**
* "This test checks for a bug whereby reconnection did not work if (a) it was
* initiated by the fetchNotifications thread and (b) it succeeded. These conditions
* are not usual, since connection failure is usually caused by either idle timeout
* (which doesn't usually happen if fetchNotifications is running) or communication
* problems (which are usually permanent so reconnection fails). But they can happen,
* so we test for them here.
* The test sets a very short idle timeout, and effectively suspends the
* fetchNotifications thread by having it invoke a listener with a delay in it.
* This means that the idle timeout happens. When the delayed listener returns,
* the fetchNotifications thread will attempt to reconnect, and this attempt should
* succeed, so we meet the two conditions above.
* The test succeeds if there is indeed a reconnection, detected by the connection
* listener seeing an OPENED notification. The connection listener should not see
* a CLOSED or FAILED notification."
*/
public class NotifReconnectDeadlockTest {
public static void main(String[] args) throws Exception {
System.out.println(
">>> Tests reconnection done by a fetching notif thread.");
ObjectName oname = new ObjectName ("Default:name=NotificationEmitter");
JMXServiceURL url = new JMXServiceURL("rmi", null, 0);
Map env = new HashMap(2);
env.put("jmx.remote.x.server.connection.timeout", new Long(serverTimeout));
env.put("jmx.remote.x.client.connection.check.period", new Long(Long.MAX_VALUE));
final MBeanServer mbs = MBeanServerFactory.newMBeanServer();
mbs.registerMBean(new NotificationEmitter(), oname);
JMXConnectorServer server = JMXConnectorServerFactory.newJMXConnectorServer(
url,
env,
mbs);
server.start();
JMXServiceURL addr = server.getAddress();
JMXConnector client = JMXConnectorFactory.connect(addr, env);
// Sleeping here was an attempt to avoid seeing an initial notification.
// This does not work, but does not matter.
// Thread.sleep(100);
client.getMBeanServerConnection().addNotificationListener(oname,
listener,
null,
null);
client.addConnectionNotificationListener(listener, null, null);
// max test time: 2 minutes
final long end = System.currentTimeMillis()+120000;
synchronized(lock) {
while(clientState == null && System.currentTimeMillis() < end) {
System.out.println("Calling sendNotifications");
mbs.invoke(oname, "sendNotifications",
new Object[] {new Notification("MyType", "", 0)},
new String[] {"javax.management.Notification"});
try {
lock.wait(1000); // sleep as no point in constant notifications
} catch (Exception e) {}
}
}
if (clientState == null) {
throw new RuntimeException(
"No reconnection happened, need to reconfigure the test.");
} else if (JMXConnectionNotification.FAILED.equals(clientState) ||
JMXConnectionNotification.CLOSED.equals(clientState)) {
throw new RuntimeException("Failed to reconnect.");
}
System.out.println(">>> Passed!");
client.removeConnectionNotificationListener(listener);
client.close();
server.stop();
}
//--------------------------
// private classes
//--------------------------
public static class NotificationEmitter extends NotificationBroadcasterSupport
implements NotificationEmitterMBean {
public void sendNotifications(Notification n) {
sendNotification(n);
}
}
public interface NotificationEmitterMBean {
public void sendNotifications(Notification n);
}
private final static NotificationListener listener = new NotificationListener() {
public void handleNotification(Notification n, Object hb) {
System.out.println("handleNotification: " + n);
if (n instanceof JMXConnectionNotification) {
if (!JMXConnectionNotification.NOTIFS_LOST.equals(n.getType())) {
// Expected: [type=jmx.remote.connection.opened][message=Reconnected to server]
clientState = n.getType();
System.out.println(
">>> The client state has been changed to: "+clientState);
synchronized(lock) {
lock.notifyAll();
}
}
return;
}
System.out.println(">>> sleeping in NotificationListener to force reconnection.");
synchronized(lock) {
try {
lock.wait(listenerSleep);
} catch (Exception e) {
// OK
}
}
}
};
// serverTimeout increased to avoid occasional problems with initial connect.
// Not using Utils.adjustTimeout to avoid accidentally making it too long.
private static final long serverTimeout = 3000;
private static final long listenerSleep = serverTimeout*6;
private volatile static String clientState = null;
private static final int[] lock = new int[0];
}
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