Introduce EmbedderReachableReferenceReporter

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/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 144 matching lines @@
       ring_buffer_end_(0),
       promotion_queue_(this),
       configured_(false),
       current_gc_flags_(Heap::kNoGCFlags),
       current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags),
       external_string_table_(this),
       gc_callbacks_depth_(0),
       deserialization_complete_(false),
       strong_roots_list_(NULL),
       heap_iterator_depth_(0),
+      embedder_heap_tracer_(nullptr),
+      embedder_reference_reporter_(new TracePossibleWrapperReporter(this)),
       force_oom_(false) {
 // Allow build-time customization of the max semispace size. Building
 // V8 with snapshots and a non-default max semispace size is much
 // easier if you can define it as part of the build environment.
 #if defined(V8_MAX_SEMISPACE_SIZE)
   max_semi_space_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
 #endif
 
   // Ensure old_generation_size_ is a multiple of kPageSize.
   DCHECK((max_old_generation_size_ & (Page::kPageSize - 1)) == 0);
@@ skipping 1433 matching lines @@
 
   // Used for updating survived_since_last_expansion_ at function end.
   intptr_t survived_watermark = PromotedSpaceSizeOfObjects();
 
   scavenge_collector_->SelectScavengingVisitorsTable();
 
   if (UsingEmbedderHeapTracer()) {
     // Register found wrappers with embedder so it can add them to its marking
     // deque and correctly manage the case when v8 scavenger collects the
     // wrappers by either keeping wrappables alive, or cleaning marking deque.
-    mark_compact_collector()->RegisterWrappersWithEmbedderHeapTracer();
+    RegisterWrappersWithEmbedderHeapTracer();
   }
 
   // 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
@@ skipping 2578 matching lines @@
       ((allocation_throughput != 0) &&
        (allocation_throughput < kLowAllocationThroughput))) {
     new_space_->Shrink();
     UncommitFromSpace();
   }
 }
 
 bool Heap::MarkingDequesAreEmpty() {
   return mark_compact_collector()->marking_deque()->IsEmpty() &&
          (!UsingEmbedderHeapTracer() ||
-          (mark_compact_collector()->wrappers_to_trace() == 0 &&
-           mark_compact_collector()
-                   ->embedder_heap_tracer()
-                   ->NumberOfWrappersToTrace() == 0));
+          (wrappers_to_trace() == 0 &&
+           embedder_heap_tracer()->NumberOfWrappersToTrace() == 0));
 }
 
 void Heap::FinalizeIncrementalMarkingIfComplete(
     GarbageCollectionReason gc_reason) {
   if (incremental_marking()->IsMarking() &&
       (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
        (!incremental_marking()->finalize_marking_completed() &&
         MarkingDequesAreEmpty()))) {
     FinalizeIncrementalMarking(gc_reason);
   } else if (incremental_marking()->IsComplete() ||
@@ skipping 1323 matching lines @@
     for (Page* p : *s) {
       CHECK(p->NeverEvacuate());
     }
 #endif  // DEBUG
   }
 
   deserialization_complete_ = true;
 }
 
 void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
-  mark_compact_collector()->SetEmbedderHeapTracer(tracer);
+  DCHECK_NOT_NULL(tracer);
+  CHECK_NULL(embedder_heap_tracer_);
+  embedder_heap_tracer_ = tracer;
 }
 
-bool Heap::UsingEmbedderHeapTracer() {
-  return mark_compact_collector()->UsingEmbedderHeapTracer();
+void Heap::RegisterWrappersWithEmbedderHeapTracer() {
+  DCHECK(UsingEmbedderHeapTracer());
+  if (wrappers_to_trace_.empty()) {
+    return;
+  }
+  embedder_heap_tracer()->RegisterV8References(wrappers_to_trace_);
+  wrappers_to_trace_.clear();
 }
 
 void Heap::TracePossibleWrapper(JSObject* js_object) {
-  mark_compact_collector()->TracePossibleWrapper(js_object);
+  DCHECK(js_object->WasConstructedFromApiFunction());
+  if (js_object->GetInternalFieldCount() >= 2 &&
+      js_object->GetInternalField(0) &&
+      js_object->GetInternalField(0) != undefined_value() &&
+      js_object->GetInternalField(1) != undefined_value()) {
+    DCHECK(reinterpret_cast<intptr_t>(js_object->GetInternalField(0)) % 2 == 0);
+    wrappers_to_trace_.push_back(std::pair<void*, void*>(
+        reinterpret_cast<void*>(js_object->GetInternalField(0)),
+        reinterpret_cast<void*>(js_object->GetInternalField(1))));
+  }
+}
+
+bool Heap::RequiresImmediateWrapperProcessing() {
+  const size_t kTooManyWrappers = 16000;
+  return wrappers_to_trace_.size() > kTooManyWrappers;
 }
 
 void Heap::RegisterExternallyReferencedObject(Object** object) {
   HeapObject* heap_object = HeapObject::cast(*object);
   DCHECK(Contains(heap_object));
   if (FLAG_incremental_marking_wrappers && incremental_marking()->IsMarking()) {
     IncrementalMarking::MarkGrey(this, heap_object);
   } else {
     DCHECK(mark_compact_collector()->in_use());
     MarkBit mark_bit = ObjectMarking::MarkBitFrom(heap_object);
@@ skipping 124 matching lines @@
     next = list->next;
     delete list;
   }
   strong_roots_list_ = NULL;
 
   delete store_buffer_;
   store_buffer_ = nullptr;
 
   delete memory_allocator_;
   memory_allocator_ = nullptr;
+
+  delete embedder_reference_reporter_;
+  embedder_reference_reporter_ = nullptr;
 }
 
 
 void Heap::AddGCPrologueCallback(v8::Isolate::GCCallback callback,
                                  GCType gc_type, bool pass_isolate) {
   DCHECK(callback != NULL);
   GCCallbackPair pair(callback, gc_type, pass_isolate);
   DCHECK(!gc_prologue_callbacks_.Contains(pair));
   return gc_prologue_callbacks_.Add(pair);
 }
@@ skipping 813 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8