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

[Gary Adams]

You are right! I had used the original thread group and missed the
need to refetch getThreadGroup().

Revised changeset:

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
@@ -63,13 +63,13 @@
          try {
              t_a.join();
          } catch (InterruptedException e) {}
+        checkInfo(t_a, t_a.getThreadGroup(), 1);

          thrinfo001b t_b = new thrinfo001b();
          t_b.setPriority(Thread.MIN_PRIORITY);
          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) {}



On 8/27/18, 1:01 PM, Alex Menkov wrote:
>
>
> 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();
>>>>       }
>>>>   }
>>>>
>>