RFR: Locked allocation

[Aleksey Shipilev]

On 12/14/2016 05:36 PM, Roman Kennke wrote:
> http://cr.openjdk.java.net/~rkennke/lockedalloc/webrev.00/

Impressive!

Comments:

*) Double/long assert in ShenandoahFreeSet::increase_used. At least break the
line, or better yet, combine two asserts in one?

*) Outdated comment:
90   // The modulo will take care of wrapping around.

*) Also, where *does* it wrap around now? Or we don't need it now, because we
guarantee all the previous regions are finally claimed, and no holes left?

*) Can we write this:

 while (_active_end - next > num) { ...

as this?

 while (next + num < _active_end) { ...

I think it is a tad more readable: the bound is on the right.

*) In RecycleDirtyRegionsClosure, there is no more add_region, why? Was that
call superfluous before?

 864       _heap->free_regions()->add_region(r);

Thanks,
-Aleksey