jmx-dev RFR 8038794: java/lang/management/ThreadMXBean/SynchronizationStatistics.java fails intermittently

[Jaroslav Bachorik]

On 07/01/2014 08:05 AM, Staffan Larsen wrote:
> Jaroslav,
>
> I wonder about this snippet:
>
>   167         ti1 = mbean.getThreadInfo(tid);
>   168         testBlocked(ti, () -> mbean.getThreadInfo(tid), lockName, lock1);
>   169         ti = ti1;
>
> When ti is used later (line 177) it may not have the values of the ThreadInfo that was actually ok:ed by testBlocked() (since testBlocked() loops). Is this a problem?

In this case it would probably make no difference since we are checking 
only for the reported number of thread blocked events being increased.

But using the actual up-to-date ThreadInfo makes the intentions clear 
and does not change the test outcome.

Updated webrev: http://cr.openjdk.java.net/~jbachorik/8038794/webrev.01

-JB-

>
> Thanks,
> /Staffan
>
>
>
> On 30 jun 2014, at 18:35, Jaroslav Bachorik <jaroslav.bachorik at oracle.com> wrote:
>
>> Please, review this test fix.
>>
>> Issue : https://bugs.openjdk.java.net/browse/JDK-8038794
>> Webrev: http://cr.openjdk.java.net/~jbachorik/8038794/webrev.00
>>
>> The problem described in this issue is that while a thread was blocked the blocked count reported by the MBean does not reflect it in very rare cases. However, it should be enough to wait a few moments to let the VM counter propagate the value to the MBean.
>>
>> The attempted fix will cause the test to wait for the expected values instead of doing a one-time check. In the worst case the test will be timed out by the harness.
>>
>> The rest of the changes just add more info to debug outputs.
>>
>> Thanks,
>>
>> -JB-
>