[heap] Concurrent slot filtering in sweeper threads.

src/heap/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 284 matching lines @@
 
     heap()->old_space()->EvictEvacuationCandidatesFromLinearAllocationArea();
     heap()->code_space()->EvictEvacuationCandidatesFromLinearAllocationArea();
 
     compacting_ = evacuation_candidates_.length() > 0;
   }
 
   return compacting_;
 }
 
-void MarkCompactCollector::ClearInvalidRememberedSetSlots() {
-  {
-    TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_CLEAR_STORE_BUFFER);
-    RememberedSet<OLD_TO_NEW>::ClearInvalidSlots(heap());
-  }
-// There is not need to filter the old to old set because
-// it is completely cleared after the mark-compact GC.
-// The slots that become invalid due to runtime transitions are
-// cleared eagerly immediately after the transition.
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    RememberedSet<OLD_TO_NEW>::VerifyValidSlots(heap());
-    RememberedSet<OLD_TO_OLD>::VerifyValidSlots(heap());
-  }
-#endif
-}
-
 void MarkCompactCollector::CollectGarbage() {
   // Make sure that Prepare() has been called. The individual steps below will
   // update the state as they proceed.
   DCHECK(state_ == PREPARE_GC);
 
   MarkLiveObjects();
 
   DCHECK(heap_->incremental_marking()->IsStopped());
 
   ClearNonLiveReferences();
@@ skipping 2070 matching lines @@
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_CLEAR_MAPS);
     ClearSimpleMapTransitions(non_live_map_list);
     ClearFullMapTransitions();
   }
 
   MarkDependentCodeForDeoptimization(dependent_code_list);
 
   ClearWeakCollections();
-
-  ClearInvalidRememberedSetSlots();
 }
 
 
 void MarkCompactCollector::MarkDependentCodeForDeoptimization(
     DependentCode* list_head) {
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_CLEAR_DEPENDENT_CODE);
   Isolate* isolate = this->isolate();
   DependentCode* current = list_head;
   while (current->length() > 0) {
     have_code_to_deoptimize_ |= current->MarkCodeForDeoptimization(
@@ skipping 1393 matching lines @@
     if (page->concurrent_sweeping_state().Value() != Page::kSweepingPending) {
       page->mutex()->Unlock();
       return 0;
     }
     page->concurrent_sweeping_state().SetValue(Page::kSweepingInProgress);
     const Sweeper::FreeSpaceTreatmentMode free_space_mode =
         Heap::ShouldZapGarbage() ? ZAP_FREE_SPACE : IGNORE_FREE_SPACE;
     if (identity == NEW_SPACE) {
       RawSweep(page, IGNORE_FREE_LIST, free_space_mode);
     } else if (identity == OLD_SPACE) {
+      RememberedSet<OLD_TO_NEW>::ClearInvalidSlots(heap_, page);

[Michael Lippautz, 2016/10/06 13:02:19]

Not change in this CL, but you could simplify the branching here :)

[Hannes Payer (out of office), 2016/10/06 13:22:40]

Done.

       max_freed = RawSweep(page, REBUILD_FREE_LIST, free_space_mode);
     } else if (identity == CODE_SPACE) {
+      RememberedSet<OLD_TO_NEW>::ClearInvalidTypedSlots(heap_, page);
       max_freed = RawSweep(page, REBUILD_FREE_LIST, free_space_mode);
     } else {
+      RememberedSet<OLD_TO_NEW>::ClearInvalidSlots(heap_, page);
       max_freed = RawSweep(page, REBUILD_FREE_LIST, free_space_mode);
     }
 
     // After finishing sweeping of a page we clean up its remembered set.
     if (page->typed_old_to_new_slots()) {
       page->typed_old_to_new_slots()->FreeToBeFreedChunks();
     }
     if (page->old_to_new_slots()) {
       page->old_to_new_slots()->FreeToBeFreedBuckets();
     }
@@ skipping 165 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8