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https://issues.apache.org/jira/browse/JENA-1873?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17069059#comment-17069059
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Andy Seaborne edited comment on JENA-1873 at 3/28/20, 12:09 AM:
----------------------------------------------------------------

This is a TopBraid error. Contact TopQuadrant support.

It is the applications responsibility to use {{StoreConnection.expel}} 
carefully. Overlapping cases are not guaranteed. As the javadoc on 
{{TDBInternal.releaseDSG}} says "Use with great care."

{{TDBInternal.releaseDSG}} should not be needed in normal operation. Deleting 
and forcing out of the JVM (which does not work on MS Windows anyway - long 
time java bug).
 
By the way: TopQuadrant TBCME release 6.3.1, the latest on their website, 
contains Jena 3.13.1, not 3.14.0.

 


was (Author: andy.seaborne):
This is a TopBraid error. Contact TopQuadrant support.

It is the applications responsibility to use {{StoreConnection.expel}} 
carefully. Overlapping cases are not guaranteed. As the javadoc on 
{{TDBInternal.releaseDSG}} says "Use with great care."

{{TDBInternal.releaseDSG}} should not be needed in normal operation. Deleting 
and forcing out of the JVM (which does not work on MS Windows anyway - long 
time java bug).
 

 

 

> Deadlock issue
> --------------
>
>                 Key: JENA-1873
>                 URL: https://issues.apache.org/jira/browse/JENA-1873
>             Project: Apache Jena
>          Issue Type: Bug
>          Components: Jena, TDB
>    Affects Versions: Jena 3.14.0
>            Reporter: Fabian Polkosnik
>            Priority: Major
>
> It is possible to face a deadlock issue when 3 threads are running in 
> parallel. It is possible to face a deadlock issue when 3 threads are running 
> in parallel.
> One of the threads is creating a new TDB dataset. The other two are deleting 
> existing ones. It's resulting in the 3 thread cycle deadlock.
> Here are the stacktraces of 3 threads that are causing the problem.
> {code:java}
> "qtp1726434078-492": 
> at org.apache.jena.tdb.sys.TDBInternal.releaseDSG(TDBInternal.java:194) - 
> waiting to lock <0x000000069a6524a0> (a java.lang.Class for 
> org.apache.jena.tdb.sys.TDBInternal) 
> at org.apache.jena.tdb.StoreConnection.expel(StoreConnection.java:214) - 
> locked <0x000000069a4568c0> (a java.lang.Class for 
> org.apache.jena.tdb.StoreConnection) 
> at org.apache.jena.tdb.StoreConnection.release(StoreConnection.java:202) - 
> locked <0x000000069a4568c0> (a java.lang.Class for 
> org.apache.jena.tdb.StoreConnection) 
> at org.topbraid.tdb.TDBGraphs.removeSingleTDB(TDBGraphs.java:167) at 
> org.topbraid.tdb.TDBGraphs.lambda$5(TDBGraphs.java:152) at 
> org.topbraid.tdb.TDBGraphs$$Lambda$677/0x00000008010e2840.run(Unknown Source) 
> at org.topbraid.tdb.TDBGraphs.destroy(TDBGraphs.java:92){code}
> {code:java}
> "qtp1726434078-151": 
> at org.apache.jena.tdb.StoreConnection.make(StoreConnection.java:240) - 
> waiting to lock <0x000000069a4568c0> (a java.lang.Class for 
> org.apache.jena.tdb.StoreConnection) 
> at org.apache.jena.tdb.StoreConnection.make(StoreConnection.java:258) at 
> org.apache.jena.tdb.transaction.DatasetGraphTransaction.<init>(DatasetGraphTransaction.java:69)
>  
> at org.apache.jena.tdb.sys.TDBMaker.createDirect(TDBMaker.java:126) at 
> org.apache.jena.tdb.sys.TDBMaker$$Lambda$682/0x0000000801117840.apply(Unknown 
> Source) 
> at 
> java.util.concurrent.ConcurrentHashMap.computeIfAbsent([email protected]/ConcurrentHashMap.java:1737)
>  - locked <0x00000006a5cdc880> (a 
> java.util.concurrent.ConcurrentHashMap$Node) 
> at org.apache.jena.tdb.sys.TDBMaker._create(TDBMaker.java:112) at 
> org.apache.jena.tdb.sys.TDBMaker.createDatasetGraphTransaction(TDBMaker.java:43){code}
> {code:java}
> "qtp1726434078-95": 
> at 
> java.util.concurrent.ConcurrentHashMap.replaceNode([email protected]/ConcurrentHashMap.java:1122)
>  - waiting to lock <0x00000006a5cdc880> (a 
> java.util.concurrent.ConcurrentHashMap$Node) 
> at 
> java.util.concurrent.ConcurrentHashMap.remove([email protected]/ConcurrentHashMap.java:1102)
>  at org.apache.jena.tdb.sys.TDBMaker.uncache(TDBMaker.java:88) 
> at org.apache.jena.tdb.sys.TDBInternal.releaseDSG(TDBInternal.java:194) - 
> locked <0x000000069a6524a0> (a java.lang.Class for 
> org.apache.jena.tdb.sys.TDBInternal) 
> at org.topbraid.tdb.TDBGraphs.removeSingleTDB(TDBGraphs.java:166) at 
> org.topbraid.tdb.TDBGraphs.lambda$5(TDBGraphs.java:152) at 
> org.topbraid.tdb.TDBGraphs$$Lambda$677/0x00000008010e2840.run(Unknown Source) 
> at org.topbraid.tdb.TDBGraphs.destroy(TDBGraphs.java:92){code}



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