--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/management/notification/BroadcasterSupportDeadlockTest.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,170 @@
+/*
+ * Copyright 2004-2005 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 5093922 2120055
+ * @summary Test that NotificationBroadcasterSupport can be subclassed
+ * and used with synchronized(this) without causing deadlock
+ * @author Eamonn McManus
+ * @run clean BroadcasterSupportDeadlockTest
+ * @run build BroadcasterSupportDeadlockTest
+ * @run main BroadcasterSupportDeadlockTest
+ */
+
+import java.lang.management.*;
+import java.util.concurrent.*;
+import javax.management.*;
+
+public class BroadcasterSupportDeadlockTest {
+ public static void main(String[] args) throws Exception {
+ try {
+ Class.forName(ManagementFactory.class.getName());
+ } catch (Throwable t) {
+ System.out.println("TEST CANNOT RUN: needs JDK 5 at least");
+ return;
+ }
+
+ final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
+ final BroadcasterMBean mbean = new Broadcaster();
+ final ObjectName name = new ObjectName("test:type=Broadcaster");
+ mbs.registerMBean(mbean, name);
+
+ ThreadMXBean threads = ManagementFactory.getThreadMXBean();
+ threads.setThreadContentionMonitoringEnabled(true);
+
+ final Semaphore semaphore = new Semaphore(0);
+
+ // Thread 1 - block the Broadcaster
+ Thread t1 = new Thread() {
+ public void run() {
+ try {
+ mbs.invoke(name, "block",
+ new Object[] {semaphore},
+ new String[] {Semaphore.class.getName()});
+ } catch (Exception e) {
+ e.printStackTrace(System.out);
+ } finally {
+ System.out.println("TEST INCORRECT: block returned");
+ System.exit(1);
+ }
+ }
+ };
+ t1.setDaemon(true);
+ t1.start();
+
+ /* Wait for Thread 1 to be doing Object.wait(). It's very
+ difficult to synchronize properly here so we wait for the
+ semaphore, then wait a little longer for the mbs.invoke to
+ run, then just in case that isn't enough, we wait for the
+ thread to be in WAITING state. This isn't foolproof,
+ because the machine could be very slow and the
+ Thread.getState() could find the thread in WAITING state
+ due to some operation it does on its way to the one we're
+ interested in. */
+ semaphore.acquire();
+ Thread.sleep(100);
+ while (t1.getState() != Thread.State.WAITING)
+ Thread.sleep(1);
+
+ // Thread 2 - try to add a listener
+ final NotificationListener listener = new NotificationListener() {
+ public void handleNotification(Notification n, Object h) {}
+ };
+ Thread t2 = new Thread() {
+ public void run() {
+ try {
+ mbs.addNotificationListener(name, listener, null, null);
+ } catch (Exception e) {
+ System.out.println("TEST INCORRECT: addNL failed:");
+ e.printStackTrace(System.out);
+ }
+ }
+ };
+ t2.setDaemon(true);
+ t2.start();
+
+ /* Wait for Thread 2 to be blocked on the monitor or to
+ succeed. */
+ Thread.sleep(100);
+
+ for (int i = 0; i < 1000/*ms*/; i++) {
+ t2.join(1/*ms*/);
+ switch (t2.getState()) {
+ case TERMINATED:
+ System.out.println("TEST PASSED");
+ return;
+ case BLOCKED:
+ java.util.Map<Thread,StackTraceElement[]> traces =
+ Thread.getAllStackTraces();
+ showStackTrace("Thread 1", traces.get(t1));
+ showStackTrace("Thread 2", traces.get(t2));
+ System.out.println("TEST FAILED: deadlock");
+ System.exit(1);
+ break;
+ default:
+ break;
+ }
+ }
+
+ System.out.println("TEST FAILED BUT DID NOT NOTICE DEADLOCK");
+ Thread.sleep(10000);
+ System.exit(1);
+ }
+
+ private static void showStackTrace(String title,
+ StackTraceElement[] stack) {
+ System.out.println("---" + title + "---");
+ if (stack == null)
+ System.out.println("<no stack trace???>");
+ else {
+ for (StackTraceElement elmt : stack)
+ System.out.println(" " + elmt);
+ }
+ System.out.println();
+ }
+
+ public static interface BroadcasterMBean {
+ public void block(Semaphore semaphore);
+ }
+
+ public static class Broadcaster
+ extends NotificationBroadcasterSupport
+ implements BroadcasterMBean {
+ public synchronized void block(Semaphore semaphore) {
+ Object lock = new Object();
+ synchronized (lock) {
+ try {
+ // Let the caller know that it can now wait for us to
+ // hit the WAITING state
+ semaphore.release();
+ lock.wait(); // block forever
+ } catch (InterruptedException e) {
+ System.out.println("TEST INCORRECT: lock interrupted:");
+ e.printStackTrace(System.out);
+ System.exit(1);
+ }
+ }
+ }
+ }
+}