RFR: Shortcutting RP during final mark misses JNI Weak Refs

[Zhengyu Gu]

Ha, that's an ugly one.

or you can hoist it out, since process_phaseJNI is public.

Thanks,

-Zhengyu


On 06/08/2017 10:05 AM, Aleksey Shipilev wrote:
> Turns out, there is landmine in RP code: we cannot shortcut on
> has_discovered_references() at our final mark reference processing, because that
> misses the JNI Weak Refs processing. Weak Refs are not counted towards
> "discovered" refs now, so we can omit marking them on shortcut, breaking the heap.
>
> Fix:
>   http://cr.openjdk.java.net/~shade/shenandoah/refproc-shortcut-jniweak/webrev.01/
>
> Heap verifier fails on jcstress because of this.
>
> Thanks,
> -Aleksey
>