[ 
https://issues.apache.org/jira/browse/JCR-3226?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Thomas Mueller updated JCR-3226:
--------------------------------
    Attachment: JCR-3226-test.patch

JCR-3226-test.patch: test case to reproduce the problem. The repository.xml 
needs to be moved to target/repository; here clustering is disabled. There is a 
sleep added before the second synchronized block, to increase the chance that a 
deadlock occurs. Sometimes the deadlock occurs after about 5-20 iterations, 
sometimes I had to restart the test. Not sure why, maybe it has to do with a 
JVM optimization (lock coarsening / lock elision / biased locking). Or maybe it 
was just bad luck.

> stateCreated deadlock
> ---------------------
>
>                 Key: JCR-3226
>                 URL: https://issues.apache.org/jira/browse/JCR-3226
>             Project: Jackrabbit Content Repository
>          Issue Type: Bug
>          Components: jackrabbit-core
>    Affects Versions: 2.2, 2.4
>            Reporter: Jukka Zitting
>            Assignee: Jukka Zitting
>              Labels: deadlock
>         Attachments: JCR-3226-test.patch
>
>
> In JCR-2650 a potential deadlock in SessionItemStateManager.stateModified() 
> got fixed by postponing the work to the save() call.
> Unfortunately this still leaves the stateCreated() method vulnerable to a 
> similar (though much less likely) deadlock scenario (observed in Jackrabbit 
> 2.2.x):
> Thread A:
>       at org.apache.jackrabbit.core.state.NodeState.copy(NodeState.java:118)
>       - waiting to lock <0x00007ffec8ddfa18> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       - locked <0x00007ffec8ddf9d8> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       at org.apache.jackrabbit.core.state.ItemState.pull(ItemState.java:152)
>       - locked <0x00007ffec8ddf9d8> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       at 
> org.apache.jackrabbit.core.state.SessionItemStateManager.stateCreated(SessionItemStateManager.java:791)
>       at 
> org.apache.jackrabbit.core.state.StateChangeDispatcher.notifyStateCreated(StateChangeDispatcher.java:94)
>       at 
> org.apache.jackrabbit.core.state.LocalItemStateManager.stateCreated(LocalItemStateManager.java:428)
>       at 
> org.apache.jackrabbit.core.state.StateChangeDispatcher.notifyStateCreated(StateChangeDispatcher.java:94)
>       at 
> org.apache.jackrabbit.core.state.SharedItemStateManager.stateCreated(SharedItemStateManager.java:398)
>       at 
> org.apache.jackrabbit.core.state.ItemState.notifyStateCreated(ItemState.java:231)
>       at 
> org.apache.jackrabbit.core.state.ChangeLog.persisted(ChangeLog.java:309)
>       at 
> org.apache.jackrabbit.core.state.SharedItemStateManager$Update.end(SharedItemStateManager.java:777)
>       at 
> org.apache.jackrabbit.core.state.SharedItemStateManager.update(SharedItemStateManager.java:1488)
>       at 
> org.apache.jackrabbit.core.state.LocalItemStateManager.update(LocalItemStateManager.java:351)
>       at 
> org.apache.jackrabbit.core.state.XAItemStateManager.update(XAItemStateManager.java:354)
>       at 
> org.apache.jackrabbit.core.state.LocalItemStateManager.update(LocalItemStateManager.java:326)
>       at 
> org.apache.jackrabbit.core.state.SessionItemStateManager.update(SessionItemStateManager.java:289)
>       at 
> org.apache.jackrabbit.core.ItemSaveOperation.perform(ItemSaveOperation.java:258)
>       at 
> org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:200)
>       at org.apache.jackrabbit.core.ItemImpl.perform(ItemImpl.java:91)
>       at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:329)
> Thread B:
>       at org.apache.jackrabbit.core.state.NodeState.copy(NodeState.java:119)
>       - waiting to lock <0x00007ffec8ddf9d8> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       - locked <0x00007ffec8ddfa18> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       at org.apache.jackrabbit.core.NodeImpl.makePersistent(NodeImpl.java:869)
>       - locked <0x00007ffec8ddfa18> (a 
> org.apache.jackrabbit.core.state.NodeState)
>       at 
> org.apache.jackrabbit.core.ItemSaveOperation.persistTransientItems(ItemSaveOperation.java:836)
>       at 
> org.apache.jackrabbit.core.ItemSaveOperation.perform(ItemSaveOperation.java:243)
>       at 
> org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:200)
>       at org.apache.jackrabbit.core.ItemImpl.perform(ItemImpl.java:91)
>       at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:329)
>       at 
> org.apache.jackrabbit.core.session.SessionSaveOperation.perform(SessionSaveOperation.java:42)
>       at 
> org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:200)
>       at org.apache.jackrabbit.core.SessionImpl.perform(SessionImpl.java:355)
>       at org.apache.jackrabbit.core.SessionImpl.save(SessionImpl.java:758)
> IIUC this can only occur when two sessions are concurrently importing a node 
> with the same UUID.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to