PI77306: DEADLOCK MAY OCCUR WHEN STOPPING LISTENER PORT

Fixes are available

APAR status

Closed as program error.

Error description

Deadlock occurs when stopping listener port.  A javacore shows
two threads that have entered a deadlocked state with
callstacks similar to below:

Waiting on condition
Monitor
Owns Monitor Lock on java/util/Vector@0x0000000089B6AC90
Java Stack
at java/lang/Object.wait(Native Method)
at java/lang/Object.wait(Object.java:172(Compiled Code))
at
com/ibm/mq/jmqi/remote/api/RemoteHconn.waitOnDispatchEvent(Remot
eHconn.java:529)
...
at
com/ibm/msg/client/jms/internal/JmsSessionImpl.close(JmsSessionI
mpl.java:343(Compiled Code))
at com/ibm/mq/jms/MQSession.close(MQSession.java:275(Compiled
Code))
at
com/ibm/ejs/jms/JMSManagedSession.destroy(JMSManagedSession.java
:529(Compiled Code))
at
com/ibm/ejs/j2c/MCWrapper.destroy(MCWrapper.java:2097(Compiled
Code))
...
at
com/ibm/ejs/j2c/ConnectionEventListener.connectionClosed(Connect
ionEventListener.java:384(Compiled Code))
at
com/ibm/ejs/jms/JMSManagedSession.handleClosed(JMSManagedSession
.java:796(Compiled Code))
...
at
com/ibm/ejs/jms/listener/ServerSessionPool.closeFreeSessions(Ser
verSessionPool.java:335)
at
com/ibm/ejs/jms/listener/ServerSessionPool.softClose(ServerSessi
onPool.java:312)
at
com/ibm/ejs/jms/listener/MDBListenerImpl.internalStop(MDBListene
rImpl.java:956)
at
com/ibm/ejs/jms/listener/JMSExceptionListener.onException(JMSExc
eptionListener.java:129)
at
com/ibm/ejs/jms/JMSManagedConnection.onException(JMSManagedConne
ction.java:1501)



Blocked
Monitor
Waiting for Monitor Lock on java/util/Vector@0x0000000089B6AC90
Java Stack
at
com/ibm/ejs/jms/listener/ServerSessionPool.getServerSession(Serv
erSessionPool.java:399(Compiled Code))
at
com/ibm/msg/client/jms/internal/JmsConnectionConsumerImpl$JmsMes
sageReferenceHandlerImpl.endDeliverInternal(JmsConnectionConsume
rImpl.java:358(Compiled Code))
at
com/ibm/msg/client/jms/internal/JmsConnectionConsumerImpl$JmsMes
sageReferenceHandlerImpl.handleMessageReference(JmsConnectionCon
sumerImpl.java:477(Compiled Code))
at
com/ibm/msg/client/jms/internal/JmsConnectionImpl$JmsProviderMes
sageRefHandler.handleMessageReference(JmsConnectionImpl.java:189
7(Compiled Code))
at
com/ibm/msg/client/wmq/internal/WMQConnectionBrowser$WMQConnecti
onBrowserShadow.consumer(WMQConnectionBrowser.java:929(Compiled
Code))
at
com/ibm/mq/jmqi/remote/impl/RemoteProxyQueue.driveConsumer(Remot
eProxyQueue.java:4350(Compiled Code))
at
com/ibm/mq/jmqi/remote/impl/RemoteProxyQueue.checkTxnMessage(Rem
oteProxyQueue.java:4243)
at
com/ibm/mq/jmqi/remote/impl/RemoteProxyQueueManager.checkTxnMess
age(RemoteProxyQueueManager.java:394)
at
com/ibm/mq/jmqi/remote/api/RemoteHconn.checkTxnMessage(RemoteHco
nn.java:325)
at
com/ibm/mq/jmqi/remote/api/RemoteHconn.doSuspend(RemoteHconn.jav
a:3334)
at
com/ibm/mq/jmqi/remote/impl/RemoteDispatchThread.processHconn(Re
moteDispatchThread.java:654(Compiled Code))
at
com/ibm/mq/jmqi/remote/impl/RemoteDispatchThread.run(RemoteDispa
tchThread.java:221(Compiled Code))
at
com/ibm/msg/client/commonservices/workqueue/WorkQueueItem.runTas
k(WorkQueueItem.java:319)
at
com/ibm/msg/client/commonservices/workqueue/SimpleWorkQueueItem.
runItem(SimpleWorkQueueItem.java:99)
at
com/ibm/msg/client/commonservices/workqueue/WorkQueueItem.run(Wo
rkQueueItem.java:341(Compiled Code))
at
com/ibm/ws/wmqcsi/workqueue/WorkQueueManagerImpl$WorkQueueRunnab
le.run(WorkQueueManagerImpl.java:550(Compiled Code))
at java/lang/Thread.run(Thread.java:785)

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  WebSphere Application Server users of       *
*                  listener ports                              *
****************************************************************
* PROBLEM DESCRIPTION: A deadlock occurs when stopping a       *
*                      listener port when using WebSphere MQ   *
*                      as the JMS Provider.                    *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The listener port code within the WebSphere Application
Server messaging component executed methods on the JMS
provider within a synchronization block.  The JMS provider also
performed its own synchronization internally and made calls
into the WebSphere Application Service messaging component
while holding its own intrinsic locks.
This meant that a thread that had acquired the intrinsic lock
in the messaging component could then block waiting for the
intrinsic lock within the JMS provider which was held by a
different thread which itself was blocked waiting for the
intrinsic lock in the messaging component.
This resulted in an ABBA deadlock.

Problem conclusion

Synchronization within the messaging component was modified so
that calls made to the external JMS provider were made outside
of intrinsic locks held by the messaging component.

The fix for this APAR is currently targeted for inclusion in
fix packs 8.0.0.14, 8.5.5.12 and 9.0.0.4.  Please refer to the
Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PI77306
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
900
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-02-28
Closed date
2017-04-18
Last modified date
2017-05-12

APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name
WEBSPHERE APP S
Fixed component ID
5724J0800

Applicable component levels

R800 PSY
UP
R850 PSY
UP
R900 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
04 May 2022

Tips

PI77306: DEADLOCK MAY OCCUR WHEN STOPPING LISTENER PORT

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R800 PSY

R850 PSY

R900 PSY

Document Information

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