[jboss-jira] [JBoss JIRA] Reopened: (JBAS-8626) QueuedPessimisticEJBLock is released too early

[Jason Greene (JIRA)]

     [ https://issues.jboss.org/browse/JBAS-8626?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jason Greene reopened JBAS-8626:
--------------------------------



Due to feedback from the community, I have split the AS7 and AS6 projects and reopened all unscheduled AS6 issues that are a year or less old. This will make it easier community members to find and work on them.

Future releases beyond 6.1 can be done provided a community member steps up to coordinate them.

> QueuedPessimisticEJBLock is released too early
> ----------------------------------------------
>
>                 Key: JBAS-8626
>                 URL: https://issues.jboss.org/browse/JBAS-8626
>             Project: Legacy JBoss Application Server 6 
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>    Affects Versions: JBossAS-3.2.7 Final, JBossAS-5.1.0.GA
>            Reporter: Judith Bürgstein
>             Fix For: No Release
>
>         Attachments: bug-0.1-SNAPSHOT.jar, jboss_logfile.log, source.jar
>
>
> Usecase:
> All xx, xy, yy and xz are representing readonly entitybean-methods and are called on one EntityBean. CMT required and reentrant true.
> The following methods are executed on the server in this order: 
> Thread1: calls entitybean.xx
> Thread1: calls entitybean.xy
> Thread2: calls entitybean.yy -> has to wait for the QueuedPessimisticEJBLock
> Thread1: returns from entitybean.xy and frees the QueuedPessimisticEJBLock                    <--- BUG
> Thread2: gets the QueuedPessimisticEJBLock but doesn't get the NonReentrantLock
> Thread1: calls entitybean.xz -> has to wait for the QueuedPessimisticEJBLock and still holds the NonReentrantLock
> Result: Undetected deadlock between QueuedPessimisticEJBLock and NonReentrantLock.
> Please use the attached bug-0.1-SNAPSHOT.jar for verification. Main class for the test is locking.bug.DeadlockTest.
> Our current workaround:
> Created a subclass of QueuedPessimisticEJBLock and override problematic method "endInvocation":
> public void endInvocation(Invocation P_mi)
>     {
>         Transaction F_tx = P_mi.getTransaction();
>         if (F_tx != null && F_tx.equals(getTransaction()))
>         {
>             EntityEnterpriseContext F_ctx = (EntityEnterpriseContext)P_mi.getEnterpriseContext();
>             if(F_ctx == null)
>             {
>                 endTransaction(F_tx);
>             }
>             else if(F_ctx.hasTxSynchronization() == false)
>             {
>                 NonReentrantLock F_mLock = F_ctx.getMethodLock();
>                 
>                 if (F_mLock == null)
>                 {
>                     endTransaction(F_tx);
>                 }
>                 else
>                 {
>                     Object F_resourceHolder = F_mLock.getResourceHolder();
>                     if (F_resourceHolder instanceof Thread
>                             && Thread.currentThread().equals(F_resourceHolder))
>                     {
>                         // don't end the transaction, because we still own the
>                         // lock!
>                     }
>                     else if (F_resourceHolder instanceof Transaction
>                             && F_tx.equals(F_resourceHolder))
>                     {
>                         // don't end the transaction, because we still own the
>                         // lock!
>                     }
>                     else
>                     {
>                         endTransaction(F_tx);
>                     }
>                 }
>             }
>             else
>             {
>                 //hasTxSynchronization is true -> don't end the transaction
>             }
>         }
>     }

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