[AMQ-1930] NPE during shutdown of embedded activemq

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 5.2.0
• Fix Version/s: NEEDS_REVIEW
• Component/s: Transport

Environment

revision 675393 of trunk, ActiveMQ 5.2.0

• Assignee: Unassigned
• Reporter: Scott Stanton
• Created: 08/Sep/08 17:59
• Updated: 13/Jul/11 18:01
• Resolved: 13/Jul/11 18:01

Description

I received the following exception from the VMTransport thread when shutting down the broker:

Async error occurred: java.lang.NullPointerException
java.lang.NullPointerException
	at org.apache.activemq.broker.TransportConnection.processRemoveConsumer(TransportConnection.java:542)
	at org.apache.activemq.command.RemoveInfo.visit(RemoveInfo.java:64)
	at org.apache.activemq.broker.TransportConnection.service(TransportConnection.java:292)
	at org.apache.activemq.broker.TransportConnection$1.onCommand(TransportConnection.java:180)
	at org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:104)
	at org.apache.activemq.transport.TransportFilter.onCommand(TransportFilter.java:68)
	at org.apache.activemq.transport.vm.VMTransport.iterate(VMTransport.java:205)
	at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:122)
	at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:43)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
	at java.lang.Thread.run(Thread.java:619)

The failure occurred at the following lines of code:

        TransportConnectionState cs = lookupConnectionState(connectionId);
        SessionState ss = cs.getSessionState(sessionId);

It appears that there is a race during shutdown where the connection state is discarded before the last consumer is removed.