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Posted to dev@openjpa.apache.org by "David Minor (JIRA)" <ji...@apache.org> on 2012/07/26 21:18:35 UTC
[jira] [Updated] (OPENJPA-1716) Deadlock with
openjpa.Multithreaded=true
[ https://issues.apache.org/jira/browse/OPENJPA-1716?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
David Minor updated OPENJPA-1716:
---------------------------------
Attachment: deadlock-fix-OPENJPA-1716.patch.txt
I've attached the fix I'm using to avoid the deadlock I was seeing. It's similar to the original patch in that it locks the broker before the state manager, but only for the particular field access call where I was seeing deadlock.
> Deadlock with openjpa.Multithreaded=true
> ----------------------------------------
>
> Key: OPENJPA-1716
> URL: https://issues.apache.org/jira/browse/OPENJPA-1716
> Project: OpenJPA
> Issue Type: Bug
> Affects Versions: 2.0.0-M1, 2.0.0-M2, 2.0.0-M3, 2.0.0-beta, 2.0.0-beta2, 2.0.0-beta3, 2.0.0
> Reporter: Stefan Wokusch
> Assignee: Rick Curtis
> Attachments: OPENJPA-1716.PATCH, deadlock-fix-OPENJPA-1716.patch.txt
>
>
> There is a Deadlock by using Multithreaded=true and work with some Threads on the same Entitymanager.
> After many hours of debugging, i found a solution for that Deadlock: The Problem could be solved by adding another lock into the lock Method of the StateManagerImpl:
> StateManagerImpl ~line3308
> /**
> * Lock the state manager if the multithreaded option is set.
> */
> protected void lock() {
> if (_instanceLock != null){
> _broker.lock();//<- This is the new Part to fix the Deadlock
> _instanceLock.lock();
> }
> }
> Worked for me without Problems for a long time.
> Some other Configurations:
> <persistence xmlns="http://java.sun.com/xml/ns/persistence"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0">
> <persistence-unit name="default" transaction-type="RESOURCE_LOCAL">
> <mapping-file>orm.xml</mapping-file>
>
> <class>...</class>
> <class>...</class>
>
> <properties>
> <property name="openjpa.OrphanedKeyAction" value="log(Channel=Orphans, Level=TRACE)" />
> <property name="openjpa.ConnectionFactoryProperties" value="PrettyPrint=true, PrettyPrintLineLength=80" />
> <property name="openjpa.Multithreaded" value="true" />
> <property name="openjpa.InverseManager" value="true" />
> <property name="openjpa.LockManager" value="none" />
> <property name="openjpa.WriteLockLevel" value="none" />
> <property name="openjpa.Compatibility" value="
> QuotedNumbersInQueries=true,
> CopyOnDetach=true,
> cascadeWithDetach=true,
> superclassDiscriminatorStrategyByDefault=false
> " />
> <property name="openjpa.DetachState" value="fetch-groups" />
> <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema" />
> <!-- Default DataSource -->
> <property name="openjpa.ConnectionURL" value="jdbc:h2:db/test" />
> <property name="openjpa.ConnectionDriverName" value="org.h2.Driver" />
> </properties>
> </persistence-unit>
> </persistence>
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