[jira] Resolved: (JCR-672) Deadlock on concurrent save/checkin operations possible

["Marcel Reutegger (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/JCR-672?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Marcel Reutegger resolved JCR-672.
----------------------------------

       Resolution: Fixed
    Fix Version/s: 1.4

The calls to VirtualItemStateProvider.setNodeReferences() do not have to be within the scope of the write lock. All virtual item state providers are repository wide anyway and must implement their own locking. Locking the workspace where the call originated is unnecessary and does not help here.

Moved the code further down where the write lock had been downgraded to a read-lock.

Also added test cases: ConcurrentVersioningTest

The tests cover the following cases:
- concurrently create version histories
- concurrently do checkin/checkouts
- concurrently create version histories and do checkin/checkouts

Fixed in revision: 533152

> Deadlock on concurrent save/checkin operations possible
> -------------------------------------------------------
>
>                 Key: JCR-672
>                 URL: https://issues.apache.org/jira/browse/JCR-672
>             Project: Jackrabbit
>          Issue Type: Bug
>          Components: versioning
>            Reporter: Przemo Pakulski
>             Fix For: 1.4
>
>
> Save and checkin operations are trying to acquire 2 locks in different order, what leads to deadlock.
> ->save
> 1.SharedItemStateManager.acquireWriteLock
> 2.AbstractVersionManager.acquireWriteLock	->	locked
> ->checkin
> 1.AbstractVersionManager.acquireWriteLock
> 2.SharedItemStateManager.acquireReadLock	->	locked
> "Thread-4" prio=6 tid=0x0312d840 nid=0x824 in Object.wait() [0x03cef000..0x03cefa68]
> 	at java.lang.Object.wait(Native Method)
> 	- waiting on <0x23210968> (a EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$WriterLock)
> 	at java.lang.Object.wait(Unknown Source)
> 	at EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$WriterLock.acquire(Unknown Source)
> 	- locked <0x23210968> (a EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$WriterLock)
> 	at org.apache.jackrabbit.core.version.AbstractVersionManager.acquireWriteLock(AbstractVersionManager.java:124)
> 	at org.apache.jackrabbit.core.version.VersionManagerImpl.setNodeReferences(VersionManagerImpl.java:413)
> 	at org.apache.jackrabbit.core.version.VersionItemStateProvider.setNodeReferences(VersionItemStateProvider.java:125)
> 	at org.apache.jackrabbit.core.state.SharedItemStateManager$Update.end(SharedItemStateManager.java:699)
> 	at org.apache.jackrabbit.core.state.SharedItemStateManager.update(SharedItemStateManager.java:810)
> 	at org.apache.jackrabbit.core.state.LocalItemStateManager.update(LocalItemStateManager.java:326)
> 	at org.apache.jackrabbit.core.state.XAItemStateManager.update(XAItemStateManager.java:313)
> 	at org.apache.jackrabbit.core.state.LocalItemStateManager.update(LocalItemStateManager.java:302)
> 	at org.apache.jackrabbit.core.state.SessionItemStateManager.update(SessionItemStateManager.java:295)
> 	at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:1204)
> 	- locked <0x2332eaa0> (a org.apache.jackrabbit.core.XASessionImpl)
> 	at JrTestDeadlock.run(JrTestDeadlock.java:87)
> "Thread-3" prio=6 tid=0x0312db18 nid=0xa04 in Object.wait() [0x03caf000..0x03cafae8]
> 	at java.lang.Object.wait(Native Method)
> 	- waiting on <0x232d1360> (a EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$ReaderLock)
> 	at java.lang.Object.wait(Unknown Source)
> 	at EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$ReaderLock.acquire(Unknown Source)
> 	- locked <0x232d1360> (a EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock$ReaderLock)
> 	at org.apache.jackrabbit.core.state.SharedItemStateManager.acquireReadLock(SharedItemStateManager.java:1361)
> 	at org.apache.jackrabbit.core.state.SharedItemStateManager.hasItemState(SharedItemStateManager.java:270)
> 	at org.apache.jackrabbit.core.state.LocalItemStateManager.hasItemState(LocalItemStateManager.java:180)
> 	at org.apache.jackrabbit.core.state.XAItemStateManager.hasItemState(XAItemStateManager.java:252)
> 	at org.apache.jackrabbit.core.state.SessionItemStateManager.hasItemState(SessionItemStateManager.java:188)
> 	at org.apache.jackrabbit.core.ItemManager.itemExists(ItemManager.java:256)
> 	at org.apache.jackrabbit.core.NodeImpl.hasProperty(NodeImpl.java:1509)
> 	at org.apache.jackrabbit.core.version.InternalFrozenNodeImpl.checkin(InternalFrozenNodeImpl.java:276)
> 	at org.apache.jackrabbit.core.version.InternalFrozenNodeImpl.checkin(InternalFrozenNodeImpl.java:248)
> 	at org.apache.jackrabbit.core.version.InternalVersionHistoryImpl.checkin(InternalVersionHistoryImpl.java:440)
> 	at org.apache.jackrabbit.core.version.AbstractVersionManager.checkin(AbstractVersionManager.java:397)
> 	at org.apache.jackrabbit.core.version.VersionManagerImpl$2.run(VersionManagerImpl.java:289)
> 	at org.apache.jackrabbit.core.version.VersionManagerImpl$DynamicESCFactory.doSourced(VersionManagerImpl.java:611)
> 	- locked <0x2320c5d8> (a org.apache.jackrabbit.core.version.VersionManagerImpl$DynamicESCFactory)
> 	at org.apache.jackrabbit.core.version.VersionManagerImpl.checkin(VersionManagerImpl.java:285)
> 	at org.apache.jackrabbit.core.version.XAVersionManager.checkin(XAVersionManager.java:161)
> 	at org.apache.jackrabbit.core.NodeImpl.checkin(NodeImpl.java:2944)
> 	at JrTestDeadlock.run(JrTestDeadlock.java:103)

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.