TDB Transaction deadlock
------------------------
Key: JENA-161
URL: https://issues.apache.org/jira/browse/JENA-161
Project: Jena
Issue Type: Bug
Components: TDB
Affects Versions: TDB 0.9.0
Environment: Windows 7 64 bit. I am using the snapshot of SVN of 10
November 2011
Reporter: Simon Helsen
While running some tests I ran into a deadlock. Unfortunately, on my 64 bit
windows 7, I was unable to trigger the complete stack trace. (there is no
equivalent of kill -3 and all known utilities to achieve this on windows don't
work with a 64 bit process). I was able to see two of the threads which were
hanging (because of a UI view in our admin console), but it is not showing the
other threads (which I'd need to see why the 2 threads I do have are hanging).
I will show the 2 threads which are hanging here in the hope it rings a bell. I
hope I will be able to get a full set of stack traces at some point
as for an analysis: Not sure if we are dealing with a double-crossed locking
issue here. It seems that thread 2 is waiting for thread 1 who clearly has the
lock on the transaction manager, but it is not clear why it is waiting on the
Transaction object. It seems that some other thread still has it and the
question is whether thread 2 could be the one (so there is a crossing of the
locks)? It would surprise me because thread 1 is doing a READ transaction and
thread 2 is doing a separate WRITE transaction.
thread 1:
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com.hp.hpl.jena.tdb.transaction.Transaction.signalEnacted(Transaction.java:178)
com.hp.hpl.jena.tdb.transaction.TransactionManager.enactTransaction(TransactionManager.java:384)
com.hp.hpl.jena.tdb.transaction.TransactionManager.processDelayedReplayQueue(TransactionManager.java:419)
com.hp.hpl.jena.tdb.transaction.TransactionManager$TSM_WriteBackEndTxn.readerFinishes(TransactionManager.java:189)
com.hp.hpl.jena.tdb.transaction.TransactionManager.readerFinishes(TransactionManager.java:609)
com.hp.hpl.jena.tdb.transaction.TransactionManager.noteTxnCommit(TransactionManager.java:472)
com.hp.hpl.jena.tdb.transaction.TransactionManager.notifyCommit(TransactionManager.java:349)
com.hp.hpl.jena.tdb.transaction.Transaction.commit(Transaction.java:100)
com.hp.hpl.jena.tdb.transaction.Transaction.close(Transaction.java:151)
com.hp.hpl.jena.tdb.DatasetGraphTxn.close(DatasetGraphTxn.java:55)
com.ibm.team.jfs.rdf.internal.jena.tdb.JenaTdbTxProvider.storeOperation(JenaTdbTxProvider.java:179)
<snip>
thread 2
------------
com.hp.hpl.jena.tdb.transaction.TransactionManager.notifyClose(TransactionManager.java:445)
com.hp.hpl.jena.tdb.transaction.Transaction.close(Transaction.java:162)
com.hp.hpl.jena.tdb.DatasetGraphTxn.close(DatasetGraphTxn.java:55)
com.ibm.team.jfs.rdf.internal.jena.tdb.JenaTdbTxProvider.storeOperation(JenaTdbTxProvider.java:285)
com.ibm.team.jfs.rdf.internal.jena.tdb.JenaTdbTxProvider.unprotectedDelete(JenaTdbTxProvider.java:1902)
com.ibm.team.jfs.rdf.internal.jena.tdb.JenaTdbTxProvider.delete(JenaTdbTxProvider.java:664)
<snip>
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