RFR: 8191333: Zero variant broken after 8189941

[John Paul Adrian Glaubitz]

On 11/16/2017 08:46 AM, Robbin Ehn wrote:
>>> Honestly, after looking at it, I have no idea.  It seems like something you should remove and see if that works.  The comment says that there should be no
>>> active handles.  Maybe have a NoHandleMark unconditionally? then SafepointMechanism::block_if_requested(THREAD) so that the comment is actually an assertion.
>>> Sorry for too quick review.
>>
>> I just tested that. This builds fine. Whether it's the way to go, I'm
>> not sure. Maybe Robbin can make a statement regarding this.
> 
> Depending on how much testing you have time for, if little time keep Handle, e.g something like:

It's not so much a matter of time but rather that I unfortunately still haven't understood
how to run the testsuite in OpenJDK. It's apparently not as simple as running "make check"
but involves configuring external programs.

>  101 #define SAFEPOINT                                                                \
>  103       {                                                                          \
>  104         /* zap freed handles rather than GC'ing them */                          \
>  105         HandleMarkCleaner __hmc(THREAD);                                         \
>  106       }                                                                          \
>  107       CALL_VM(SafepointMechanism::block_if_requested(THREAD), handle_exception);
> 

Yep. That's what I did. Shall we just go with this approach?

> If this is the only places that zero does safepoints poll, thread-local handshake should actually work with above.
> I can test it if/when I get time.
> 
>>
>> The freshly JVM is run during the build if I remember correctly, so I
>> assume it works with this particular change.
> 
> If you build the image, yes.

Yes, that's what I did.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
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`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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