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https://issues.apache.org/jira/browse/AMQ-5260?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14149020#comment-14149020
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Gary Tully commented on AMQ-5260:
---------------------------------
@matteo - i have not had the opportunity to delve into this... but for the
mutex transport - my understanding is that is there to protect the socket
writes - there can be multiple sessions/producers on a connection and they all
want to send data concurrently over the socket. Openwire allows interleaving at
the command level only. In addition there openwire cache depends on serial
inserts on both ends of the channel, the mutex protects that also.
inversion of lock order is a bug. It is great that you are investigating this
in such detail, thanks. This code has evolved quite a bit so the more eyes on
it the better.
> Cross talk over duplex network connection can lead to blocking (alternative
> take)
> ---------------------------------------------------------------------------------
>
> Key: AMQ-5260
> URL: https://issues.apache.org/jira/browse/AMQ-5260
> Project: ActiveMQ
> Issue Type: Bug
> Affects Versions: 5.9.0, 5.10.0
> Reporter: matteo rulli
> Attachments: AMQ5260AdvancedTest.java, AMQ_5260.patch,
> AMQ_5260_2.patch, AMQ_5260_3.patch, deadlock.jpg, debug.jpg
>
>
> Pretty the same description with respect to AMQ-4328.
> ----
> !deadlock.jpg!
> h2. Stacktraces:
> Stacktrace no.1:
> {noformat}
> Name: ActiveMQ NIO Worker 12
> State: BLOCKED on java.net.URI@1bae2b28 owned by: ActiveMQ Transport:
> tcp:///10.0.1.219:61616@57789
> Total blocked: 2 Total waited: 67
> Stack trace:
>
> org.apache.activemq.network.DemandForwardingBridgeSupport.serviceRemoteConsumerAdvisory(DemandForwardingBridgeSupport.java:714)
> org.apache.activemq.network.DemandForwardingBridgeSupport.serviceRemoteCommand(DemandForwardingBridgeSupport.java:581)
> org.apache.activemq.network.DemandForwardingBridgeSupport$3.onCommand(DemandForwardingBridgeSupport.java:191)
> org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116)
> org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50)
> org.apache.activemq.transport.WireFormatNegotiator.onCommand(WireFormatNegotiator.java:113)
> org.apache.activemq.transport.AbstractInactivityMonitor.onCommand(AbstractInactivityMonitor.java:270)
> org.apache.activemq.transport.TransportSupport.doConsume(TransportSupport.java:83)
> org.apache.activemq.transport.nio.NIOTransport.serviceRead(NIOTransport.java:138)
> org.apache.activemq.transport.nio.NIOTransport$1.onSelect(NIOTransport.java:69)
> org.apache.activemq.transport.nio.SelectorSelection.onSelect(SelectorSelection.java:94)
> org.apache.activemq.transport.nio.SelectorWorker$1.run(SelectorWorker.java:119)
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
> java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
> java.lang.Thread.run(Unknown Source)
> {noformat}
> ----
> stack trace no.2
> {noformat}
> Name: ActiveMQ Transport: tcp:///10.0.1.219:61616@57789
> State: WAITING on
> java.util.concurrent.locks.ReentrantLock$NonfairSync@3cdbfa3e owned by:
> ActiveMQ BrokerService[master2] Task-4
> Total blocked: 19 Total waited: 3
> Stack trace:
> sun.misc.Unsafe.park(Native Method)
> java.util.concurrent.locks.LockSupport.park(Unknown Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(Unknown
> Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(Unknown
> Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Unknown Source)
> java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(Unknown Source)
> java.util.concurrent.locks.ReentrantLock.lock(Unknown Source)
> org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:66)
> org.apache.activemq.transport.ResponseCorrelator.oneway(ResponseCorrelator.java:60)
> org.apache.activemq.broker.TransportConnection.dispatch(TransportConnection.java:1339)
> org.apache.activemq.broker.TransportConnection.processDispatch(TransportConnection.java:858)
> org.apache.activemq.broker.TransportConnection.dispatchSync(TransportConnection.java:818)
> org.apache.activemq.broker.TransportConnection$1.onCommand(TransportConnection.java:151)
> org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116)
> org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50)
> org.apache.activemq.transport.vm.VMTransport.doDispatch(VMTransport.java:138)
> org.apache.activemq.transport.vm.VMTransport.dispatch(VMTransport.java:127)
> - locked java.util.concurrent.atomic.AtomicBoolean@689389da
> org.apache.activemq.transport.vm.VMTransport.oneway(VMTransport.java:104)
> org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:68)
> org.apache.activemq.transport.ResponseCorrelator.asyncRequest(ResponseCorrelator.java:81)
> org.apache.activemq.transport.ResponseCorrelator.request(ResponseCorrelator.java:86)
> org.apache.activemq.network.DemandForwardingBridgeSupport.addSubscription(DemandForwardingBridgeSupport.java:856)
> org.apache.activemq.network.DemandForwardingBridgeSupport.addConsumerInfo(DemandForwardingBridgeSupport.java:1128)
> org.apache.activemq.network.DemandForwardingBridgeSupport.serviceRemoteConsumerAdvisory(DemandForwardingBridgeSupport.java:714)
> - locked java.net.URI@1bae2b28
> org.apache.activemq.network.DemandForwardingBridgeSupport.serviceRemoteCommand(DemandForwardingBridgeSupport.java:581)
> org.apache.activemq.network.DemandForwardingBridgeSupport$3.onCommand(DemandForwardingBridgeSupport.java:191)
> org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116)
> org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50)
> org.apache.activemq.transport.failover.FailoverTransport$3.onCommand(FailoverTransport.java:196)
> org.apache.activemq.transport.WireFormatNegotiator.onCommand(WireFormatNegotiator.java:113)
> org.apache.activemq.transport.AbstractInactivityMonitor.onCommand(AbstractInactivityMonitor.java:270)
> org.apache.activemq.transport.TransportSupport.doConsume(TransportSupport.java:83)
> org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:214)
> org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:196)
> java.lang.Thread.run(Unknown Source)
> {noformat}
> ----
> stack trace no.3
> {noformat}
> Name: ActiveMQ BrokerService[master2] Task-4
> State: WAITING on
> java.util.concurrent.locks.ReentrantLock$NonfairSync@717bb9c owned by:
> ActiveMQ Transport: tcp:///10.0.1.219:61616@57789
> Total blocked: 19 Total waited: 117
> Stack trace:
> sun.misc.Unsafe.park(Native Method)
> java.util.concurrent.locks.LockSupport.park(Unknown Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(Unknown
> Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(Unknown
> Source)
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Unknown Source)
> java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(Unknown Source)
> java.util.concurrent.locks.ReentrantLock.lock(Unknown Source)
> org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:66)
> org.apache.activemq.transport.ResponseCorrelator.oneway(ResponseCorrelator.java:60)
> org.apache.activemq.network.DemandForwardingBridgeSupport.serviceLocalCommand(DemandForwardingBridgeSupport.java:921)
> org.apache.activemq.network.DemandForwardingBridgeSupport$2.onCommand(DemandForwardingBridgeSupport.java:173)
> org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116)
> org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50)
> org.apache.activemq.transport.vm.VMTransport.doDispatch(VMTransport.java:138)
> org.apache.activemq.transport.vm.VMTransport.dispatch(VMTransport.java:127)
> - locked java.util.concurrent.atomic.AtomicBoolean@453bb109
> org.apache.activemq.transport.vm.VMTransport.oneway(VMTransport.java:104)
> org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:68)
> org.apache.activemq.transport.ResponseCorrelator.oneway(ResponseCorrelator.java:60)
> org.apache.activemq.broker.TransportConnection.dispatch(TransportConnection.java:1339)
> org.apache.activemq.broker.TransportConnection.processDispatch(TransportConnection.java:858)
> org.apache.activemq.broker.TransportConnection.iterate(TransportConnection.java:904)
> org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:129)
> org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:47)
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
> java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
> java.lang.Thread.run(Unknown Source)
> {noformat}
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