RFR: JDK-8019927: [TESTBUG] nsk/jvmti/GetThreadInfo/thrinfo001 intermittently fails with 'invalid thread group' when running with JFR

[Alex Menkov]

On 08/27/2018 05:08, Gary Adams wrote:
> I just tried the suggestion to add the check after thread1 join call
> and it fails with :
> 
>   Thread thread1: invalid thread group
> 
> If a thread completes and we join the thread, not all information
> of the terminated thread is available.

Per spec after thread termination both Thread.getThreadGroup() and jvmti 
GetThreadInfo should return null.
IsSameObject should return JNI_TRUE if both objects are NULL.
Could you please investigate which function returns unexpected value.

--alex

> 
> I think we need to limit the test checking to before starting the
> thread and again while it is running. If the thread is finished,
> we can not perform the checks reliably.
> 
> On 8/24/18, 8:11 PM, Alex Menkov wrote:
>> Hi Gary,
>>
>> Removing 1st checkInfo (just after t_b.start()) looks good, but I 
>> don't think 2nd checkInfo call should be dropped.
>> I'd rather added checkInfo for t_a after t_a.join()
>> Then the test will cover 3 cases - before thread is started, while 
>> thread is running (checkInfo from thread.run()) and after thread 
>> termination.
>>
>> --alex
>>
>> On 08/24/2018 05:19, Gary Adams wrote:
>>> David pointed out the flaw in this test a long time ago, but
>>> no one followed through to fix the test. When the test thread
>>> runs to completion, there is no way to get the thread info
>>> for the comparisons being made in checkInfo().
>>>
>>> The test already calls checkInfo before starting the thread
>>> and again in the test thread run method. The change below
>>> will make the thrinfo001a and thrinfo001b tests perform the
>>> same checking. It will avoid the race condition when thrinfo001b
>>> finishes quickly.
>>>
>>>    Issue: https://bugs.openjdk.java.net/browse/JDK-8019927
>>>
>>>
>>> diff --git 
>>> a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetThreadInfo/thrinfo001.java 
>>> b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetThreadInfo/thrinfo001.java
>>> --- 
>>> a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetThreadInfo/thrinfo001.java
>>> +++ 
>>> b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetThreadInfo/thrinfo001.java
>>> @@ -69,11 +69,9 @@
>>>           t_b.setDaemon(true);
>>>           checkInfo(t_b, t_b.getThreadGroup(), 2);
>>>           t_b.start();
>>> -        checkInfo(t_b, t_b.getThreadGroup(), 2);
>>>           try {
>>>               t_b.join();
>>>           } catch (InterruptedException e) {}
>>> -        checkInfo(t_b, t_b.getThreadGroup(), 2);
>>>           return getRes();
>>>       }
>>>   }
>>>
>