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kmarsden edited comment on DERBY-3980 at 12/12/08 1:52 PM:
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Thanks Mike for the tips and recommending tests.  I am studying the code but must admit I am still a bit baffled by it all.
I do think I can help by writing regression tests, so we can feel confident in the fix when we get one.   I'll write one for the simple deadlock case that I know works and  I'd like to write a test for the live lock scenario.  Do I just need three  threads,  2 doing a repeated staggered select and another trying to get in and do an update?
 
Are there any other tests that would be good?

Thanks

Kathey


      was (Author: kmarsden):
    Thanks Mike for the tips and recommending tests.  I am studying the code but must admit I am still a bit baffled by it all.
I do think I can help by writing regression tests, so we can feel confident in the fix when we get one.   I'll write one for the simple deadlock case that I know works and  I'd like to write a test for the live lock scenario.  Do I just need two threads,  1 doing a repeated select and another trying to get in and do an update?
 
Are there any other tests that would be good?

Thanks

Kathey

  
> Conflicting select then update with REPEATABLE_READ gives lock timeout instead of deadlock
> ------------------------------------------------------------------------------------------
>
>                 Key: DERBY-3980
>                 URL: https://issues.apache.org/jira/browse/DERBY-3980
>             Project: Derby
>          Issue Type: Bug
>          Components: Store
>    Affects Versions: 10.1.3.1, 10.2.2.0, 10.3.3.0, 10.4.2.0, 10.5.0.0
>            Reporter: Kathey Marsden
>         Attachments: derby-3980_javadoc_and_test_diff.txt, derby.log, derby.log.10_1, javacore.20081209.092827.9800.txt, TryTimeout.java, TryTimeout2.java, TryTimeout2.out.10_1.deadlock, TryTimeout2.out.10_1.deadlock, TryTimeout2.out.10_1.locktimeout, TryTimeout2.out.10_1.locktimeout
>
>
> The attached program TryTimeout.java should detect a deadlock but instead throws a lock timeout exception.  The program has two threads that attempt:
> 	    
> 	    threadConnection.setAutoCommit(false);
> 	    /* set isolation level to repeatable read */
> 	    threadConnection.setTransactionIsolation(Connection.TRANSACTION_REPEATABLE_READ);
> 	    
> 	    ResultSet rs = stmt.executeQuery("select * from t where i = 456");
> 	    while (rs.next());
> 	    stmt.executeUpdate("update t set i = 456 where i = 456");
> 	    threadConnection.commit();
> This gives SQLState 40001 (deadlock) with DB2 but a lock timeout with Derby.

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