RFR (XXS): 6771058: TEST_BUG: java/lang/ref/Basic.java may fail with -server -Xcomp

Christian Thalinger christian.thalinger at oracle.com
Thu Oct 18 22:37:36 UTC 2012

On Oct 18, 2012, at 3:31 PM, Mandy Chung <mandy.chung at oracle.com> wrote:

> Hi Christian,
> Thanks for taking on this bug.

Sure.  I'm trying to get HotSpot nightly failures down.

> Just curious - the test runs with a max of 10 GCs. You
> reproduced this bug on a slower machine with fastdebug build.
> If you increase the max number of GCs, I wonder how long
> the test will take to complete/pass?

Around 14 GCs (runtime with -Xcomp approximately 40 seconds on that particular machine).

> With your fix, how many GC does it take to complete?
> I suspect it's one.  

Between 2 and 3 GCs.

> I am guessing that the test might
> want to test that the finalizers are being invoked during
> GC and references are dequeued.  I wonder if there is
> another alternate fix instead of forcing the finalizers
> to be run.  Just a thought.

The fix was not my idea.  I just picked the bug and tried the suggested fix and it worked.  The other suggested fix is to increase the sleep time (but I don't like that).

-- Chris

> Mandy
> On 10/18/2012 2:43 PM, Christian Thalinger wrote:
>> http://cr.openjdk.java.net/~twisti/6771058
>> 6771058: TEST_BUG: java/lang/ref/Basic.java may fail with -server -Xcomp
>> Reviewed-by:
>> This test can fail if finalizer of Basic is not called for some
>> reason.  It happens in compiled mode if compilation is more slow than
>> execution of the main loop.
>> The fix is to call System.runFinalization() after System.gc() to
>> ensure that finalizer is run.
>> test/java/lang/ref/Basic.java

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