RFR (S): 8223736:jvmti/scenarios/contention/TC04/tc04t001/TestDescription.java fails due to wrong number of MonitorContendedEntered events

[Alex Menkov]

LGTM

--alex

On 06/20/2019 16:59, serguei.spitsyn at oracle.com wrote:
> Hi Alex,
> 
> Thank you a lot for review!
> 
> 
> 
> On 6/20/19 16:30, Alex Menkov wrote:
>> Hi Serguei,
>>
>> Main idea looks good.
>>
>> I'd simplify threads[i].join/threads[i].done logic with CountDownLatch
>> (note also exception message ("Thread-" + i + " was interrupted by 
>> timeout!") is not correct):
>>
>> in tc04t001 class add
>>   final static CountDownLatch threadsDoneSignal = new 
>> CountDownLatch(THREADS_LIMIT);
>>
>> replace cycle of threads[i].join / threads[i].done check with
>>   if (!threadsDoneSignal.await(timeout, TimeUnit.MILLISECONDS)) {
>>     throw new RuntimeException("Threads timeout");
>>   }
>> at the end of tc04t001Thread.run
>> replace
>>   done = true;
>> with
>>   tc04t001.threadsDoneSignal.countDown();
> 
> Okay, thanks!
> I've made this change.
> 
> The updated webrev is:
> http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8223736-mon-events-test.2/ 
> 
> 
> It also includes the changes suggested by Dan.
> 
> Thanks,
> Serguei
> 
>>
>> --alex
>>
>> On 06/19/2019 18:59, serguei.spitsyn at oracle.com wrote:
>>> Sorry, forgot the  bug title to add to the email subject.
>>>
>>> Thanks,
>>> Serguei
>>>
>>> On 6/19/19 6:09 PM, serguei.spitsyn at oracle.com wrote:
>>>> Please review a fix for test bug:
>>>>   https://bugs.openjdk.java.net/browse/JDK-8223736
>>>>
>>>> Webrev:
>>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8223736-mon-events-test.1/ 
>>>>
>>>>
>>>> Summary:
>>>>  It seems that waiting for 0.5 sec for a MonitorContendedEnter event 
>>>> in the
>>>>  increment() method sometime is not enough (especially when the JFR 
>>>> is enabled).
>>>>  The fix implement an approach to ensure the event has posted before 
>>>> the worker
>>>>  thread goes to the next iteration.
>>>>  Also, another check is added to diagnose if any of two worker threads
>>>>  (tc04t001Thread) has been interrupted by timeout.
>>>>  In fact, we have many other tests which miss this kind of check and 
>>>> diagnostics.
>>>>  We may want to consider fixing other cases if we encounter this 
>>>> eventually happens.
>>>>
>>>> Testing:
>>>>  A mach5 test submission is in progress.
>>>>
>>>> Thanks,
>>>> Serguei
>>>>
>>>
>