[Shenandoah 11u backport] 8229919: Support JNI Critical functions in object pinning API on x86_32 platforms

[Zhengyu Gu]

On 2/19/20 6:14 PM, Roman Kennke wrote:
> Looks good to me.
> 
> Roman
> 
> PS: I wonder if we should take these parts to upstream 11u eventually,
> that would bring down our shared-code exposure considerably. OTOH, only
> Shenandoah uses these code paths. Hmm.
> 
> Or could we take the whole code path to ShenandoahBarrierSetAssembler,
> call it right before:
> 
> unpack_array_argument(..)
> 
> like we do elsewhere? E.g.:
> 
> #ifdef INCLUDE_SHENANDOAHGC
>    if (UseShenandoahGC) {
>      ShenandoahBarrierSetAssembler::bsasm()->gen_object_pinning();
>    }
> #endif
> unpack_array_argument(..);
> 
> and move all the rest of the code into ShBSA?

Well, bringing down these parts of code to 11u, likely results a clean 
backport, probably less risky than refactoring.

Thanks,

-Zhengyu

> 
> That should be a follow-up though because it would also do the same code
> movements for x86_64 and aarch64.
> 
> Roman
> 
>> I would like backport JDK-8229919 to Shenandoah 11u.
>>
>> http://cr.openjdk.java.net/~zgu/JDK-8229919/11u/webrev.00/
>>
>> Test:
>>    hotspot_gc_shenandoah x86_32 on Linux
>>
>> Thanks,
>>
>> -Zhengyu
>>
>