Hello,

I noticed the latest commit to AbandonedObjectPool.java in the Jakarta Commons DBCP 
project. The changes seem to fix some thread blocking that I have observed lately on 
our Tomcat uPortal app.

I tried out the new nightly (9/24/03) today, and I think another point of thread 
contention has been exposed when using the validate connection features of DBCP. I'm 
worried that if the validation query takes too long/hangs then all the other threads 
that want a connection will be blocked until it times out. Do you think I'm on the 
right track?

"Thread-43" daemon prio=1 tid=0x0x85215f8 nid=0x29be waiting for monitor entry
        [5b80b000..5b80c840]
        at 
org.apache.commons.dbcp.PoolableConnectionFactory.validateObject(PoolableConnectionFactory.java:316)
        - waiting to lock <0x45b85a98> (a 
org.apache.commons.dbcp.PoolableConnectionFactory)
        at 
org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:833)

--- several threads like the above wait on the following to complete:

"Thread-98" daemon prio=1 tid=0x0x8691b10 nid=0x2a1d runnable [5c4ff000..5c501840]
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:129)
        at oracle.net.ns.Packet.receive(Unknown Source)
        at oracle.net.ns.NetInputStream.getNextPacket(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.jdbc.ttc7.MAREngine.unmarshalUB1(MAREngine.java:931)
        at oracle.jdbc.ttc7.MAREngine.unmarshalSB1(MAREngine.java:893)
        at oracle.jdbc.ttc7.v8Odscrarr.receive(v8Odscrarr.java:178)
        at oracle.jdbc.ttc7.TTC7Protocol.describe(TTC7Protocol.java:754)
        - locked <0x4dda5560> (a oracle.jdbc.ttc7.TTC7Protocol)
        at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteDescribe(TTC7Protocol.java:860)
        - locked <0x4dda5560> (a oracle.jdbc.ttc7.TTC7Protocol)
        at
oracle.jdbc.driver.OracleStatement.doExecuteQuery(OracleStatement.java:2391)
        at
oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2672)
        at oracle.jdbc.driver.OracleStatement.executeQuery(OracleStatement.java:572)
        - locked <0x44f61438> (a oracle.jdbc.driver.OracleStatement)
        - locked <0x4e07b950> (a oracle.jdbc.driver.OracleConnection)
        at
org.apache.commons.dbcp.DelegatingStatement.executeQuery(DelegatingStatement.java:188)
        at
org.apache.commons.dbcp.PoolableConnectionFactory.validateConnection(PoolableConnectionFactory.java:338)
        - locked <0x45b85a98> (a org.apache.commons.dbcp.PoolableConnectionFactory)
        at
org.apache.commons.dbcp.PoolableConnectionFactory.validateObject(PoolableConnectionFactory.java:318)
        - locked <0x45b85a98> (a org.apache.commons.dbcp.PoolableConnectionFactory)
        at
org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:833)
----------------

Thanks,

Brad Johnson
Texas Tech University

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