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

[serguei.spitsyn at oracle.com]

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
>>>
>>