RFR(S): 8141356: Explicitly stop CMS threads during VM termination.

Jungwoo Ha jwha at google.com
Wed Nov 4 17:33:37 UTC 2015


Unfortunately, we cannot provide the test publicly.
But we do have internal tests that triggers this bug, and got fixed with
this patch.

On Wed, Nov 4, 2015 at 9:25 AM, Jon Masamitsu <jon.masamitsu at oracle.com>
wrote:

>
>
> On 11/3/2015 5:32 PM, Jungwoo Ha wrote:
>
> Somehow I didn't receive Jon's email.
> We've first noticed this on JDK8, but I think the bug is more triggered
> with the tcmalloc + custom launcher.
>
>
> Jungwoo,
>
> Do you have a test that exhibits the bug?
>
> Jon
>
>
>
> On Tue, Nov 3, 2015 at 4:14 PM, Carsten Varming <varming at gmail.com> wrote:
>
>> Dear Jon,
>>
>> I am pretty sure this has been that way for a long time. I have never
>> seen a problem, but I would like to see Hotspot shut down its threads as
>> well.
>>
>> Carsten
>>
>> On Tue, Nov 3, 2015 at 5:40 PM, Jon Masamitsu <
>> <jon.masamitsu at oracle.com>jon.masamitsu at oracle.com> wrote:
>>
>>> Jungwoo,
>>>
>>> Did you first see this bug in jdk8?  I'm wondering if it
>>> was always broken.
>>>
>>> Jon
>>>
>>> On 11/03/2015 01:14 PM, Jungwoo Ha wrote:
>>>
>>> BUG:  <https://bugs.openjdk.java.net/browse/JDK-8141356>
>>> https://bugs.openjdk.java.net/browse/JDK-8141356
>>> Webrev: http://cr.openjdk.java.net/~jwha/8141356/webrev.00/
>>>
>>> Inside before_exit(), it says
>>>
>>>   // Stop concurrent GC threads
>>>   Universe::heap()->stop();
>>>
>>> but GenCollectedHeap never implemented stop() method, and thus calling
>>> empty SharedHeap::stop() method.
>>> This causes CMS threads to run during the VM termination and ends up
>>> crashing.
>>> ConcurrentMarkSweepThread::stop() is currently a dead code and never
>>> gets called.
>>> The patch just implemented GenCollectedHeap::stop() to call
>>> ConcurrentMarkSweepThread::stop().
>>>
>>> Can someone sponsor this patch?
>>>
>>> --
>>> Jungwoo Ha | Google | <jwha at google.com>jwha at google.com
>>>
>>>
>>>
>>
>
>
> --
> Jungwoo Ha | Java Platform Team | jwha at google.com
>
>
>


-- 
Jungwoo Ha | Java Platform Team | jwha at google.com
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