ConcurrentModificationException in SingleConnectionFactory$AggregatedExceptionListener [SPR-13421]

[spring-projects-issues]

Mike Noordermeer opened SPR-13421 and commented

The SingleConnectionFactory$AggregatedExceptionListener objects contains a list of delegates in a LinkedHashSet, protected by the SingleConnectionFactory.connectionMonitor lock object.

If you configure a SingleConnectionFactory with reconnectOnException = true, and use it in a SimpleMessageListenerContainer, the following will happen on a JMSException:

1. SingleConnectionFactory$AggregatedExceptionListener.onException() is called, and starts looping over the delegates Set
2. At a certain point in time, it will call SimpleMessageListenerContainer.onException(), which calls refreshSharedConnection(), createSharedConnection(), prepareSharedConnection(), connection.setExceptionListener()
3. This modifies the delegates list (from the same thread, so the locking does not help)
4. A ConcurrentModificationException will be thrown in SingleConnectionFactory$AggregatedExceptionListener.onException()

Full exception message:

Exception in thread "ActiveMQ Connection Executor: tcp://localhost/127.0.0.1:61616@52892" java.util.ConcurrentModificationException
	at java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:711)
	at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:734)
	at org.springframework.jms.connection.SingleConnectionFactory$AggregatedExceptionListener.onException(SingleConnectionFactory.java:670)
	at org.apache.activemq.ActiveMQConnection$5.run(ActiveMQConnection.java:2004)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

The list of delegates should probably be copied before iteration, or the SimpleMessageListenerContainer should not re-add itself as listener.

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Affects: 4.1.7, 4.2.1

Issue Links:

• Memory leak with SimpleMessageListenerContainer and ChainedExceptionListener on Single/CachingConnectionFactory [SPR-10397] #15030 Memory leak with SimpleMessageListenerContainer and ChainedExceptionListener on Single/CachingConnectionFactory
• JMS Integration with Tibco causes deadlock while using DefaultMessageListenerContainer [SPR-15738] #20294 JMS Integration with Tibco causes deadlock while using DefaultMessageListenerContainer

Referenced from: commits f562eb5, 1ed1167

Backported to: 4.1.8

[spring-projects-issues]

Juergen Hoeller commented

Good catch! Fixed for 4.2.2 now, and to be backported to 4.1.8.

Feel free to give the upcoming 4.2.2.BUILD-SNAPSHOT an early try...

Juergen