[heap] Fine-grained JSArrayBuffer tracking

src/heap/heap.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/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 1608 matching lines @@
   gc_state_ = SCAVENGE;
 
   // Implements Cheney's copying algorithm
   LOG(isolate_, ResourceEvent("scavenge", "begin"));
 
   // Used for updating survived_since_last_expansion_ at function end.
   intptr_t survived_watermark = PromotedSpaceSizeOfObjects();
 
   scavenge_collector_->SelectScavengingVisitorsTable();
 
-  array_buffer_tracker()->PrepareDiscoveryInNewSpace();
-
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
   new_space_.Flip();
   new_space_.ResetAllocationInfo();
 
   // We need to sweep newly copied objects which can be either in the
   // to space or promoted to the old generation.  For to-space
   // objects, we treat the bottom of the to space as a queue.  Newly
   // copied and unswept objects lie between a 'front' mark and the
   // allocation pointer.
@@ skipping 87 matching lines @@
   incremental_marking()->UpdateMarkingDequeAfterScavenge();
 
   ScavengeWeakObjectRetainer weak_object_retainer(this);
   ProcessYoungWeakReferences(&weak_object_retainer);
 
   DCHECK(new_space_front == new_space_.top());
 
   // Set age mark.
   new_space_.set_age_mark(new_space_.top());
 
-  array_buffer_tracker()->FreeDead(true);
+  array_buffer_tracker()->FreeDeadInNewSpace();
 
   // Update how much has survived scavenge.
   IncrementYoungSurvivorsCounter(static_cast<int>(
       (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size()));
 
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
   gc_state_ = NOT_IN_GC;
 }
 
@@ skipping 259 matching lines @@
   return object;
 }
 
 
 HeapObject* Heap::DoubleAlignForDeserialization(HeapObject* object, int size) {
   return AlignWithFiller(object, size - kPointerSize, size, kDoubleAligned);
 }
 
 
 void Heap::RegisterNewArrayBuffer(JSArrayBuffer* buffer) {
-  return array_buffer_tracker()->RegisterNew(buffer);
+  const bool track_live =
+      Page::FromAddress(buffer->address())->IsFlagSet(Page::BLACK_PAGE);

[Hannes Payer (out of office), 2016/05/20 12:21:17]

Instead of checking for black page, it would be better to check for object color
to be independent of black pages.

[Michael Lippautz, 2016/05/23 08:41:00]

Done.

+  return array_buffer_tracker()->RegisterNew(buffer, track_live);
 }
 
 
 void Heap::UnregisterArrayBuffer(JSArrayBuffer* buffer) {
   return array_buffer_tracker()->Unregister(buffer);
 }
 
 
 void Heap::ConfigureInitialOldGenerationSize() {
   if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) {
@@ skipping 4333 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8