RFR: 8234768: Shenandoah: Streamline enqueueing runtime barriers

[Zhengyu Gu]

Nice cleanup and looks good to me.

Thanks,

-Zhengyu

On 11/26/19 8:48 AM, Roman Kennke wrote:
> Shenandoah's runtime barriers for SATB pre-date the GC interface, and
> have been very coarsly fitted into the new GC interfaces. It leaves room
> for improvements:
> - Rename methods to make more sense
> - Group enqueueing barrier methods together
> - Make them inlinable, including the ultimate enqueue() method
> - Avoid barriers on DEST_UNINITIALIZED pre-barriers
> - Benefit from static resolution of decorators when possible, and don't
> generate barriers at all in those cases
> 
> As a bonus, add SATB and traversal store-value barriers to native oop
> stores. This is not doing anything now, but will enable concurrent roots
> scanning in the near future.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8234768
> Webrev:
> http://cr.openjdk.java.net/~rkennke/JDK-8234768/webrev.00/
> 
> Can I please get a review?
> 
> Thanks,
> Roman
>