RFR: Shenandoah String Dedup refactoring

[Aleksey Shipilev]

On 07/02/2018 07:51 PM, Zhengyu Gu wrote:
> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/shared_stringdedup/webrev.02/

Nice to see another upstream diff ripout!

*) Should we split out ShenandoahWorkerSession into a separate changeset for backporting?

*) In shenandoahHeap.cpp, this does not seem to be needed:
 2196   ShenandoahHeap* heap = ShenandoahHeap::heap();

*) Use locals:

 105   static inline uint worker_id() {
 106     Thread* thr = Thread::current();
 107     assert(ShenandoahThreadLocalData::worker_id(thr) !=
ShenandoahThreadLocalData::INVALID_WORKER_ID, "Worker session has not been created");
 108     return ShenandoahThreadLocalData::worker_id(thr);
 109   }

...

static inline uint worker_id() {
  Thread* thr = Thread::current();
  id = ShenandoahThreadLocalData::worker_id(thr);
  assert(id != ShenandoahThreadLocalData::INVALID_WORKER_ID, "Worker session has not been created");
  return id;
}

Thanks,
-Aleksey