RFR: Shenandoah String Dedup refactoring

[Zhengyu Gu]

Shenandoah only webrev:
http://cr.openjdk.java.net/~zgu/shenandoah/dedup_shared_refactor/sh-only/webrev.00/

Thanks,

-Zhengyu

On 05/29/2018 03:54 PM, Zhengyu Gu wrote:
> Hi,
> 
> This refactoring is based on upstream JDK-8203641, which is still under 
> review 
> (http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-May/032565.html).
> 
> We initially borrowed G1's string deduplication implementation, but we 
> diverged at one point, due to we may need to enqueue candidates inside 
> write barrier. It is not the case anymore.
> 
> Once JDK-8203641 upstreamed, we can share dedup table and thread 
> implementation, only need to plugin in our queue implementation.
> 
> It looks like StringDedupTable is another candidate to be replaced by 
> ConcurrentHashTable, we should be able to benefit from it too.
> 
> 
> Webrev: 
> http://cr.openjdk.java.net/~zgu/shenandoah/dedup_shared_refactor/webrev.00/
> 
> 
> Test:
>    hotspot_gc_shenandoah (fastdebug and release)
> 
> Thanks,
> 
> -Zhengyu
>