[jboss-jira] [JBoss JIRA] Commented: (JGRP-507) CloserThread's attempt to interrupt TimeScheduler on closure could be end up being ignored

[Galder Zamarreno (JIRA)]

    [ http://jira.jboss.com/jira/browse/JGRP-507?page=comments#action_12374627 ] 
            
Galder Zamarreno commented on JGRP-507:
---------------------------------------

Bela, it was fixed in 2.4.1.SP3. I just posted the link to the case that raised 
this a few months ago.

> CloserThread's attempt to interrupt TimeScheduler on closure could be end up being ignored
> ------------------------------------------------------------------------------------------
>
>                 Key: JGRP-507
>                 URL: http://jira.jboss.com/jira/browse/JGRP-507
>             Project: JGroups
>          Issue Type: Bug
>    Affects Versions: 2.3 SP1, 2.3, 2.4.1 SP2, 2.4.1 SP1, 2.4.1, 2.4, 2.2.9 SP4, 2.2.9 SP3 (2.2.9.3), 2.2.9.2, 2.2.9.1, 2.2.9, 2.2.8, 2.2.7 SP1
>            Reporter: Galder Zamarreno
>         Assigned To: Bela Ban
>             Fix For: 2.6
>
>
> A race condition in JGroups could cause a channel that should be closed (for example, after being shunned) 
> to never be closed.
> In order to stop TimeScheduler thread, CloserThread set's TimeScheduler's thread status 
> as interrupted. If the interruption occurs while TimeScheduler is waiting, then no problems.
> But, in TimeScheduler._run(), actual running of a task via task.run(); happens outside
> synchronized(queue) block which means that CloserThread could set the TimeSchedule thread's 
> status as interrupted while the task is running, for example, sending an FD are-you-alive message.
> If down the protocol that's carrying out the task, all down threads are set to false, and TimeScheduler 
> thread is interrupted while the task is running, the interruption could be caught while sending a message to network:
> TP (UDP and TCP/TCP_NIO's parent):
> TP.down(Event evt)
> ....
> try {
> if(use_outgoing_packet_handler)
> outgoing_queue.put(msg);
> else
> send(msg, dest, multicast);
> }
> catch(QueueClosedException closed_ex) {
> }
> catch(InterruptedException interruptedEx) {
> }
> catch(Throwable e) {
> if(log.isErrorEnabled()) log.error("failed sending message", e);
> } 
> Catching InterruptedException and doing nothing will clear the Thread's interrupted status. If 
> the interruption from CloserThread is caught here, TimeScheduler thread will never finished, 
> leaving the channel blocked and never rejoining the cluster and unable to merge back.

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