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

[Gary Adams]

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.

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();
>>       }
>>   }
>>