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https://issues.apache.org/jira/browse/DERBY-3980?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12657204#action_12657204
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Knut Anders Hatlen commented on DERBY-3980:
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I understood Mike's comment as that we should make sure a livelock wasn't
detected as a deadlock (false positive) after we make the changes, which means
we would have to run deadlock detection on a possible livelock situation in
order to test it. I have problems seeing how changes to the deadlock detection
algorithm could cause a regression in a test that doesn't exercise that
algorithm. But I agree that it's good to have this test too. Just shortening
the deadlock timeout or increasing the time the select threads hold the locks
would additionally make it test the deadlock detection algorithm, though.
> 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, LiveLockTest_diff.txt,
> LockTimeoutWithInserts.java, 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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