RFR(XS): 8028306: nsk stress tests, CodeCache fills, then safepoint asserts

[Albert Noll]

Igor, Vladimir, thanks for the reviews.

Best,
Albert

On 11/14/2013 06:31 PM, Vladimir Kozlov wrote:
> Changes are good.
>
> Thanks,
> Vladimir K
>
> On 11/14/13 2:58 AM, Albert Noll wrote:
>> Hi Vladimir,
>>
>> thanks for your feedback. Yes, it is possible that a non-compiler 
>> thread calls
>> 'possibly_sweep()'. E.g., 'create_native_wrapper()' can be called by 
>> a non-compiler
>> thread ('sharedRuntime.cpp') and calls 'handle_full_code_cache()' 
>> which in turn
>> 'calls possibly_sweep()'.
>>
>> I added the check, since I encountered a failing assert (example 
>> above) that checks
>> that only compiler threads call the sweeper. I think it is fine to 
>> have the check in there
>> since we only possibly sweep.
>>
>> Best,
>> Albert
>>
>> On 11/14/2013 11:36 AM, Vladimir Ivanov wrote:
>>> Albert,
>>>
>>> Thanks for fixing that. Missed that case when added 
>>> No_Safepoint_Verifier.
>>>
>>> ciEnv.cpp: looks good.
>>> sweeper.cpp: is it possible NMethodSweeper::possibly_sweep is called 
>>> in non-compiler thread? Why don't you turn the
>>> check into assert?
>>>
>>> Best regards,
>>> Vladimir Ivanov
>>>
>>> On 11/14/13 1:36 PM, Albert Noll wrote:
>>>> Hi,
>>>>
>>>> could I have reviews for this small patch?
>>>>
>>>> webrev: http://cr.openjdk.java.net/~anoll/8028306/webrev.00/
>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8028306
>>>>
>>>> problem: 1) ciEnv::register_method() calls
>>>> CodeCache::handle_full_code_cache() in a
>>>>                     block where no safepoints are allowed. However,
>>>> handle_full_code_cache
>>>>                     can reach a safepoint since it uses locks.
>>>>                  2) I added a check in 'possibly_sweep()' that ensures
>>>> that only compiler threads
>>>>                      can sweep the code cache. It can happen that 
>>>> normal
>>>> Java threads can call
>>>>                      'possibly_sweep()' via 
>>>> 'handle_full_code_cache()'.
>>>> solution:  1) move call to 'handle_full_code_cache()' outside the 
>>>> block
>>>> where no safepoints
>>>>                      are allowed
>>>>                  2) see above
>>>>
>>>> testing: failing test case passes.
>>>>
>>>>
>>>> Many thanks in advance,
>>>> Albert
>>>>
>>>>
>>>>
>>