jmx-dev RFR 7144200: java/lang/management/ClassLoadingMXBean/LoadCounts.java failed with JFR enabled

[Jaroslav Bachorik]

On 7.10.2013 16:22, Daniel Fuchs wrote:
> Hi Jaroslav,
>
> I am not an expert in classloading but I don't see any obvious
> issue with what you propose.

I hope there is none :) If the number of loaded classes is not changing 
the test should continue immediately. The only problem could be loading 
the classes veeery slowly - not increasing the number of the loaded 
classes in 300ms interval. We could get a false positive and end up with 
the same failure as now :(

>
> I wonder whether making the test always run in /othervm mode
> might make it more stable.

I don't know. I was not able to reproduce the problem but from the 
description it sounds like it is spotted only with JFR enabled. So, I 
suppose, running it in othervm would not help at all.

-JB-

>
> best regards,
>
> -- daniel
>
> On 10/7/13 3:59 PM, Jaroslav Bachorik wrote:
>> The test captures the number of loaded classes right at the start and
>> then checks the diffs when it's finished. However, it seems that there
>> might by some async class loading still going on, initiated by JFR.
>>
>> The patch simply adds a loop to wait for the number of loaded classes to
>> settle before continuing. This should prevent the test failing with JFR
>> intermittently.
>>
>> Issue:  https://bugs.openjdk.java.net/browse/JDK-7144200
>> Webrev: http://cr.openjdk.java.net/~jbachorik/7144200/webrev.00/
>>
>> Cheers,
>>
>> -JB-
>