#107 Got java.util.ConcurrentModificationException


Hi there,

One of my user in my project has reported the following exception stacktrace. Would anyone here know what can cause this?

Caused by: java.sql.SQLException: An SQLException was provoked by the following failure: java.util.ConcurrentModificationException
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:62)
at com.mchange.v2.c3p0.impl.NewProxyConnection.close(NewProxyConnection.java:1271)
at myschedule.quartz.extra.JdbcSchedulerHistoryPlugin.withConn(JdbcSchedulerHistoryPlugin.java:193)
... 10 more
Caused by: java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:806)
at java.util.HashMap$KeyIterator.next(HashMap.java:841)
at com.mchange.v2.c3p0.stmt.GooGooStatementCache.checkinAll(GooGooStatementCache.java:286)
at com.mchange.v2.c3p0.impl.NewPooledConnection.checkinAllCachedStatements(NewPooledConnection.java:589)
at com.mchange.v2.c3p0.impl.NewPooledConnection.markClosedProxyConnection(NewPooledConnection.java:298)
at com.mchange.v2.c3p0.impl.NewProxyConnection.close(NewProxyConnection.java:1246)
... 11 more

Ref: http://code.google.com/p/myschedule/issues/detail?id=73


  • Steve Waldman

    Steve Waldman - 2012-02-24


    can you please tell me what version of c3p0 you are using? the statement cache was significantly overhauled in the latest prerelease issue in a way which hopefully eliminated this sort of race condition. are you using the latest "stable" release c3p0-, or the current "pre" release 0.9.2-pre1?

    if the stable release, please try the "pre" release.

    many thanks.

  • Zemian Deng

    Zemian Deng - 2012-02-24

    We are using c3p0- Which version do you recommend us using?

  • Zemian Deng

    Zemian Deng - 2012-02-24

    Oh, never mind. I see you said use "c3p0-". Sure, we will give this a try and let you know.

  • Zemian Deng

    Zemian Deng - 2012-02-24

    BTW, I don't see latest "c3p0-" on Maven central yet. Is there way you guys can publish it soon?

    Much thanks!

  • Steve Waldman

    Steve Waldman - 2012-05-13
    • status: open --> closed
  • Steve Waldman

    Steve Waldman - 2012-05-13


    I'm closing this one for now, as I believe it is fixed in the current pre-release. The request for publication to a Maven repository is well taken, and I hope to get to c3p0-0.9.2 final soon. But that's a different issue than this bug. If you see ConcurrentModificationExceptions on 0.9.2, please repost the bug. Thanks!


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