src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp

rev 58202 : 8240217: Shenandoah: remove ShenandoahEvacAssist
Reviewed-by: XXX

*** 142,188 ****
  
    oop fwd = resolve_forwarded_not_null_mutator(obj);
    if (obj == fwd) {
      assert(_heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL),
             "evac should be in progress");
! 
!     ShenandoahEvacOOMScope oom_evac_scope;
! 
!     Thread* thread = Thread::current();
!     oop res_oop = _heap->evacuate_object(obj, thread);
! 
!     // Since we are already here and paid the price of getting through runtime call adapters
!     // and acquiring oom-scope, it makes sense to try and evacuate more adjacent objects,
!     // thus amortizing the overhead. For sparsely live heaps, scan costs easily dominate
!     // total assist costs, and can introduce a lot of evacuation latency. This is why we
!     // only scan for _nearest_ N objects, regardless if they are eligible for evac or not.
!     // The scan itself should also avoid touching the non-marked objects below TAMS, because
!     // their metadata (notably, klasses) may be incorrect already.
! 
!     size_t max = ShenandoahEvacAssist;
!     if (max > 0) {
!       // Traversal is special: it uses incomplete marking context, because it coalesces evac with mark.
!       // Other code uses complete marking context, because evac happens after the mark.
!       ShenandoahMarkingContext* ctx = _heap->is_concurrent_traversal_in_progress() ?
!                                       _heap->marking_context() : _heap->complete_marking_context();
! 
!       ShenandoahHeapRegion* r = _heap->heap_region_containing(obj);
!       assert(r->is_cset(), "sanity");
! 
!       HeapWord* cur = cast_from_oop<HeapWord*>(obj) + obj->size();
! 
!       size_t count = 0;
!       while ((cur < r->top()) && ctx->is_marked(oop(cur)) && (count++ < max)) {
!         oop cur_oop = oop(cur);
!         if (cur_oop == resolve_forwarded_not_null_mutator(cur_oop)) {
!           _heap->evacuate_object(cur_oop, thread);
!         }
!         cur = cur + cur_oop->size();
!       }
!     }
! 
!     fwd = res_oop;
    }
  
    if (load_addr != NULL && fwd != obj) {
      // Since we are here and we know the load address, update the reference.
      ShenandoahHeap::cas_oop(fwd, load_addr, obj);
--- 142,153 ----
  
    oop fwd = resolve_forwarded_not_null_mutator(obj);
    if (obj == fwd) {
      assert(_heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL),
             "evac should be in progress");
!     ShenandoahEvacOOMScope scope;
!     fwd = _heap->evacuate_object(obj, Thread::current());
    }
  
    if (load_addr != NULL && fwd != obj) {
      // Since we are here and we know the load address, update the reference.
      ShenandoahHeap::cas_oop(fwd, load_addr, obj);