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https://issues.apache.org/jira/browse/DERBY-2689?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Manish Khettry updated DERBY-2689:
----------------------------------
Attachment: deadlock.patch.txt
I have moved the logic that closes unused activations. Earlier this was done
when a activation was initialized and added to a lcc.
at
org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.addActivation(Unknown
Source)
at org.apache.derby.impl.sql.execute.BaseActivation.initFromContext(Unknown
Source)
at
org.apache.derby.impl.services.reflect.LoadedGeneratedClass.newInstance(Unknown
Source)
at
org.apache.derby.impl.services.reflect.ReflectGeneratedClass.newInstance(Unknown
Source)
at org.apache.derby.impl.sql.GenericActivationHolder.<init>(Unknown Source)
Now it is done by the caller (outside a synchronized block) whenever a
statement is prepared or executed in GenericPreparedStatement:getActivation.
For testing, I ran the reproduction attached with this bug. Without the bugfix
it would deadlock within a few minutes. I let it run all morning and all the
threads were making progress before I stopped the threads around noon. I also
ran the reproduction with DERBY-418. Without the cleanup code being invoked,
the test would run out of memory after about 230K iterations (with 20m heap
size). With the bugfix I let it run to about 1m iterations before stopping the
process. Also derbylang.
The patch was made against trunk.
> Deadlock with GenericPreparedStatement
> --------------------------------------
>
> Key: DERBY-2689
> URL: https://issues.apache.org/jira/browse/DERBY-2689
> Project: Derby
> Issue Type: Bug
> Components: JDBC
> Affects Versions: 10.2.2.0
> Environment: Windows
> Reporter: Marc Ewert
> Assignee: Manish Khettry
> Priority: Critical
> Attachments: deadlock.patch.txt, TestDerbyPreparedStatements.java
>
>
> We encountered two times a deadlock inside of derby. It seems that we can't
> workaround it. The involved two threads are attached, it looks like a
> classical deadlock:
> "Thread-22" daemon prio=6 tid=0x0cdaa400 nid=0x1c0 waiting for monitor entry
> [0x1317f000..0x1317fd4c]
> java.lang.Thread.State: BLOCKED (on object monitor)
> at org.apache.derby.impl.sql.GenericPreparedStatement.finish(Unknown
> Source)
> - waiting to lock <0x052f4d70> (a
> org.apache.derby.impl.sql.GenericPreparedStatement)
> at org.apache.derby.impl.sql.execute.BaseActivation.close(Unknown
> Source)
> at
> org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.addActivation(Unknown
> Source)
> at
> org.apache.derby.impl.sql.execute.BaseActivation.initFromContext(Unknown
> Source)
> at
> org.apache.derby.impl.services.reflect.LoadedGeneratedClass.newInstance(Unknown
> Source)
> at
> org.apache.derby.impl.services.reflect.ReflectGeneratedClass.newInstance(Unknown
> Source)
> at org.apache.derby.impl.sql.GenericActivationHolder.<init>(Unknown
> Source)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.getActivation(Unknown
> Source)
> - locked <0x05306f88> (a
> org.apache.derby.impl.sql.GenericPreparedStatement)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown
> Source)
> at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
> - locked <0x047beb00> (a org.apache.derby.impl.jdbc.EmbedConnection40)
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
> [custom methods]
> "ThreadPoolThread-SyncScheduler-3-1" prio=2 tid=0x0e620400 nid=0xfec waiting
> for monitor entry [0x10a7e000..0x10a7fa14]
> java.lang.Thread.State: BLOCKED (on object monitor)
> at org.apache.derby.impl.sql.GenericPreparedStatement.finish(Unknown
> Source)
> - waiting to lock <0x05306f88> (a
> org.apache.derby.impl.sql.GenericPreparedStatement)
> at org.apache.derby.impl.sql.execute.BaseActivation.close(Unknown
> Source)
> at
> org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.addActivation(Unknown
> Source)
> at
> org.apache.derby.impl.sql.execute.BaseActivation.initFromContext(Unknown
> Source)
> at
> org.apache.derby.impl.services.reflect.LoadedGeneratedClass.newInstance(Unknown
> Source)
> at
> org.apache.derby.impl.services.reflect.ReflectGeneratedClass.newInstance(Unknown
> Source)
> at org.apache.derby.impl.sql.GenericActivationHolder.<init>(Unknown
> Source)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.getActivation(Unknown
> Source)
> - locked <0x052f4d70> (a
> org.apache.derby.impl.sql.GenericPreparedStatement)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown
> Source)
> at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
> - locked <0x04225178> (a org.apache.derby.impl.jdbc.EmbedConnection40)
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
> [custom methods]
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