RFR 8251118: BiasedLocking::preserve_marks should not have a HandleMark

[Coleen Phillimore]

On 8/11/20 4:45 PM, Patricio Chilano wrote:
>
> On 8/11/20 5:34 PM, Daniel D. Daugherty wrote:
>> On 8/11/20 4:27 PM, Patricio Chilano wrote:
>>> Hi Dan,
>>>
>>> Thanks for looking at this.
>>>
>>> On 8/11/20 4:53 PM, Daniel D. Daugherty wrote:
>>>> On 8/11/20 2:11 PM, Patricio Chilano wrote:
>>>>> Hi all,
>>>>>
>>>>> Please review the following small fix which involves removing the 
>>>>> added HandleMark in BiasedLocking::preserve_marks():
>>>>>
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8251118
>>>>> Webrev: http://cr.openjdk.java.net/~pchilanomate/8251118/v1/webrev/
>>>>
>>>> src/hotspot/share/runtime/biasedLocking.cpp
>>>>     No comments.
>>>>
>>>> As mentioned by Harold, adding a new test case to:
>>>>
>>>>     test/hotspot/jtreg/runtime/7158988/FieldMonitor.java
>>>>
>>>> that enables '-XX:+UseBiasedLocking' is a good idea.
>>> I suggested adding it to test TestFullGCALot.java instead because it 
>>> fails much more consistently.
>>
>> I'm good with that also.

Me too, even better than FieldMonitor.java if it's more reproduceable.

>>
>>
>>>
>>>> Also, Coleen added this note to your bug report:
>>>>
>>>>> Also in the patch for JDK-8249192 
>>>>> <https://bugs.openjdk.java.net/browse/JDK-8249192>, vframe.hpp 
>>>>> shouldn't include
>>>>> handles.inline.hpp (only cpp and inline.hpp files can include
>>>>> inline.hpp). It doesn't look like it needs handles.inline.hpp,
>>>>> only handles.hpp. 
>>>>
>>>> Were you planning on resolving that left over in this bug?
>>> Not really. I can change it here if you are okay though.
>>
>> Your call on whether to fix it here or with a new bug. Seems
>> like fixing it here is less work... this bug is a follow-on to
>> the original and that comment is a follow-on to the original...
> Yeah, sounds good to me to remove the extra header in this change. 
> I'll check it builds fine on all platforms first.
> Below is v2 in case you wanted to see it:
>
> Full: http://cr.openjdk.java.net/~pchilanomate/8251118/v2/webrev/
> Inc: http://cr.openjdk.java.net/~pchilanomate/8251118/v2/inc/webrev/

I think vframe.hpp should include handles.hpp because there are Handle 
types in it, just in case something changes and it's not transiently 
included anymore.

Otherwise, everything looks good.  I don't need to see another webrev.

thanks!
Coleen
>
> Thanks Dan!
>
> Patricio
>> Dan
>>
>>
>>>
>>> Patricio
>>>> Dan
>>>>
>>>>
>>>>>
>>>>> I've inspected the callers of BiasedLocking::preserve_marks() and 
>>>>> they all have an assert that the current thread is the VMThread. 
>>>>> Since the VMThread creates a HandleMark object before executing a 
>>>>> VM operation the extra HandleMark added in 8249192 is not needed.
>>>>> I've run tiers1-3 in mach5 with -XX:+UseBiasedLocking and without 
>>>>> the patch I get several crashes in BiasedLocking::restore_marks(). 
>>>>> With the patch tests completed successfully.
>>>>>
>>>>> Thanks,
>>>>> Patricio
>>>>>
>>>>
>>>
>>
>