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6809322: javax.management.timer.Timer does not fire all notifications

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Some notifications get dropped due to ConcurrentModificationException thrown in Timer.notifyAlarmClock() method.

Reviewed-by: dholmes, rbackman
This commit is contained in:
Jaroslav Bachorik 2012-10-17 18:34:07 +04:00 committed by Dmitry Samersoff
parent a76d98e716
commit 9c38da478a
2 changed files with 150 additions and 19 deletions
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39
jdk/src/share/classes/javax/management/timer/Timer.java
View File

@ -28,8 +28,7 @@ package javax.management.timer;
import static com.sun.jmx.defaults.JmxProperties.TIMER_LOGGER;
import java.util.ArrayList;
import java.util.Date;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
@ -128,8 +127,8 @@ public class Timer extends NotificationBroadcasterSupport
* Table containing all the timer notifications of this timer,
* with the associated date, period and number of occurrences.
*/
private Map<Integer,Object[]> timerTable =
new Hashtable<Integer,Object[]>();
final private Map<Integer,Object[]> timerTable =
new HashMap<>();
/**
* Past notifications sending on/off flag value.
@ -163,7 +162,7 @@ public class Timer extends NotificationBroadcasterSupport
* The notification counter ID.
* Used to keep the max key value inserted into the timer table.
*/
private int counterID = 0;
volatile private int counterID = 0;
private java.util.Timer timer;
@ -776,7 +775,7 @@ public class Timer extends NotificationBroadcasterSupport
*
* @return The number of timer notifications.
*/
public int getNbNotifications() {
public synchronized int getNbNotifications() {
return timerTable.size();
}
@ -824,7 +823,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return The timer notification type or null if the identifier is not mapped to any
* timer notification registered for this timer MBean.
*/
public String getNotificationType(Integer id) {
public synchronized String getNotificationType(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -841,7 +840,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return The timer notification detailed message or null if the identifier is not mapped to any
* timer notification registered for this timer MBean.
*/
public String getNotificationMessage(Integer id) {
public synchronized String getNotificationMessage(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -862,7 +861,7 @@ public class Timer extends NotificationBroadcasterSupport
//public Serializable getNotificationUserData(Integer id) {
// end of NPCTE fix for bugId 4464388
public Object getNotificationUserData(Integer id) {
public synchronized Object getNotificationUserData(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
return ( ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getUserData() );
@ -878,7 +877,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return A copy of the date or null if the identifier is not mapped to any
* timer notification registered for this timer MBean.
*/
public Date getDate(Integer id) {
public synchronized Date getDate(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -896,7 +895,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return A copy of the period or null if the identifier is not mapped to any
* timer notification registered for this timer MBean.
*/
public Long getPeriod(Integer id) {
public synchronized Long getPeriod(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -913,7 +912,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return A copy of the remaining number of occurrences or null if the identifier is not mapped to any
* timer notification registered for this timer MBean.
*/
public Long getNbOccurences(Integer id) {
public synchronized Long getNbOccurences(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -931,7 +930,7 @@ public class Timer extends NotificationBroadcasterSupport
* @return A copy of the flag indicating whether a periodic notification is
* executed at <i>fixed-delay</i> or at <i>fixed-rate</i>.
*/
public Boolean getFixedRate(Integer id) {
public synchronized Boolean getFixedRate(Integer id) {
Object[] obj = timerTable.get(id);
if (obj != null) {
@ -982,7 +981,7 @@ public class Timer extends NotificationBroadcasterSupport
*
* @return <CODE>true</CODE> if the list of timer notifications is empty, <CODE>false</CODE> otherwise.
*/
public boolean isEmpty() {
public synchronized boolean isEmpty() {
return (timerTable.isEmpty());
}
@ -1184,11 +1183,13 @@ public class Timer extends NotificationBroadcasterSupport
//
TimerAlarmClock alarmClock = (TimerAlarmClock)notification.getSource();
for (Object[] obj : timerTable.values()) {
if (obj[ALARM_CLOCK_INDEX] == alarmClock) {
timerNotification = (TimerNotification)obj[TIMER_NOTIF_INDEX];
timerDate = (Date)obj[TIMER_DATE_INDEX];
break;
synchronized(Timer.this) {
for (Object[] obj : timerTable.values()) {
if (obj[ALARM_CLOCK_INDEX] == alarmClock) {
timerNotification = (TimerNotification)obj[TIMER_NOTIF_INDEX];
timerDate = (Date)obj[TIMER_DATE_INDEX];
break;
}
}
}

130
jdk/test/javax/management/timer/MissingNotificationTest.java Normal file
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@ -0,0 +1,130 @@
/*
* Copyright (c) 2008, 2012, 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 6809322
* @summary Test for missing notifications in a high concurrency environment
* @author Jaroslav Bachorik
* @run clean MissingNotificationTest
* @run build MissingNotificationTest
* @run main MissingNotificationTest
*/
import java.util.Date;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import javax.management.timer.Timer;
import javax.management.Notification;
import javax.management.NotificationListener;
public class MissingNotificationTest {
private static int TASK_COUNT = 10000;
private static long fixedDelay = 0;// anything bigger than 100 and no alarms remain unfired
private static class NotifListener implements NotificationListener {
int count;
public synchronized void handleNotification(Notification notification, Object handback) {
count++;
}
synchronized int getCount() {
return count;
}
}
public static void main(String[] args) throws Exception {
System.out.println(
">>> Test for missing notifications.");
System.out.println(">>> Create a Timer object.");
final Timer timer = new Timer();
timer.start();
NotifListener listener = new NotifListener();
timer.addNotificationListener(listener, null, null);
ExecutorService executor = Executors.newFixedThreadPool(100);
final Random rand = new Random();
for (int i = 0; i < TASK_COUNT; i++) {
executor.execute(new Runnable() {
public void run() {
long dateMillis = System.currentTimeMillis() + fixedDelay + rand.nextInt(2000);
Date date = new Date(dateMillis);
timer.addNotification("type", "msg", "userData", date);
}
});
}
executor.shutdown();
executor.awaitTermination(20, TimeUnit.SECONDS);
waitForNotificationsToEnd(listener);
timer.stop();
if (listener.count < TASK_COUNT) {
throw new RuntimeException("Not fired: " + (TASK_COUNT - listener.count));
} else {
System.out.println(">>> All notifications handled OK");
}
System.out.println(">>> Bye bye!");
}
/**
* Will return when all notifications are handled or after 10sec. of no new
* notifications
*
* @param listener
* @throws InterruptedException
*/
private static void waitForNotificationsToEnd(NotifListener listener)
throws InterruptedException {
int oldCout = listener.getCount();
int noChangeCounter = 1;
while (listener.getCount() < TASK_COUNT) {
Thread.sleep(1000);
System.out.print('.');
if (oldCout == listener.getCount())//no change
{
if (++noChangeCounter > 10) {
break;
}
} else {
noChangeCounter = 1;
}
oldCout = listener.getCount();
}
System.out.println();
}
}