[jboss-jira] [JBoss JIRA] Resolved: (JBAS-6874) TimerImpl should set ACTIVE state before scheduling to avoid race condition

[Brian Stansberry (JIRA)]

     [ https://jira.jboss.org/jira/browse/JBAS-6874?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Brian Stansberry resolved JBAS-6874.
------------------------------------

    Fix Version/s:     (was: JBossAS-6.0.0.M3)
       Resolution: Done


> TimerImpl should set ACTIVE state before scheduling to avoid race condition
> ---------------------------------------------------------------------------
>
>                 Key: JBAS-6874
>                 URL: https://jira.jboss.org/jira/browse/JBAS-6874
>             Project: JBoss Application Server
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>          Components: Scheduling/Timers
>    Affects Versions: JBossAS-4.0.5.GA, JBossAS-4.2.0.GA, JBossAS-4.2.1.GA, JBossAS-4.2.2.GA, JBossAS-4.2.3.GA, JBossAS-5.0.0.GA, JBossAS-5.0.1.GA, JBossAS-5.1.0.Beta1, JBossAS-5.1.0.CR1
>            Reporter: Galder Zamarreno
>            Assignee: Galder Zamarreno
>             Fix For: JBossAS-5.1.0.GA
>
>         Attachments: server.log
>
>
> TimerImpl sets ACTIVE state after it's scheduled the timer task which means that you can have a race 
> condition leading to something like this:
> 2009-04-28 18:55:03,370 45084 DEBUG [org.jboss.ejb.txtimer.TimerImpl] (ScannerThread:) setTimerState: created
> 2009-04-28 18:55:03,372 45086 DEBUG [org.jboss.ejb.txtimer.TimerImpl] (EJB-Timer-2[target=jboss.j2ee:service=EJB3,jar=acme-ejb3.jar,name=ProblematicTimerManagerProxyBean]:) run: [id=2,target=[target=jboss.j2ee:service=EJB3,jar=acme-ejb3.jar,name=ProblematicTimerManagerProxyBean],remaining=-438372,periode=0,created]
> 2009-04-28 18:55:03,372 45086 DEBUG [org.jboss.ejb.txtimer.TimerImpl] (EJB-Timer-2[target=jboss.j2ee:service=EJB3,jar=acme-ejb3.jar,name=ProblematicTimerManagerProxyBean]:) setTimerState: in_timeout
> 2009-04-28 18:55:03,372 45086 DEBUG [org.jboss.ejb.txtimer.TimerImpl] (ScannerThread:) setTimerState: active 
> Sometimes, the timer can kick off even before it's timer state has been set to active, which means that active state will be set after in_timeout. 
> What's the effect of this? After the timer has executed, this means that the finally clause in TimerTaskImpl.run() won't be executed and hence, 
> the timer won't be deleted from the database. This leads to multiple timer executions.
> Please find attached a thread dump where you can see EJB-Timer-1 being executed correctly, including removal from database, but EJB-Timer-2 is not.

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