Use EmbedderHeapTracer instead of object grouping when trace_embedder_heap flag is set

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 41 matching lines @@
 #ifdef DEBUG
       state_(IDLE),
 #endif
       marking_parity_(ODD_MARKING_PARITY),
       was_marked_incrementally_(false),
       evacuation_(false),
       heap_(heap),
       marking_deque_memory_(NULL),
       marking_deque_memory_committed_(0),
       code_flusher_(nullptr),
+      embedder_heap_tracer_(nullptr),
       have_code_to_deoptimize_(false),
       compacting_(false),
       sweeping_in_progress_(false),
       pending_sweeper_tasks_semaphore_(0),
       pending_compaction_tasks_semaphore_(0) {
 }
 
 #ifdef VERIFY_HEAP
 class VerifyMarkingVisitor : public ObjectVisitor {
  public:
@@ skipping 1882 matching lines @@
 // pointers.  After: the marking stack is empty and there are no overflowed
 // objects in the heap.
 void MarkCompactCollector::ProcessMarkingDeque() {
   EmptyMarkingDeque();
   while (marking_deque_.overflowed()) {
     RefillMarkingDeque();
     EmptyMarkingDeque();
   }
 }
 
-
 // Mark all objects reachable (transitively) from objects on the marking
 // stack including references only considered in the atomic marking pause.
 void MarkCompactCollector::ProcessEphemeralMarking(
     ObjectVisitor* visitor, bool only_process_harmony_weak_collections) {
   bool work_to_do = true;
   DCHECK(marking_deque_.IsEmpty() && !marking_deque_.overflowed());
   while (work_to_do) {
-    if (!only_process_harmony_weak_collections) {
+    if (UsingEmbedderHeapTracer()) {
+      embedder_heap_tracer()->TraceWrappableFrom(
+          reinterpret_cast<v8::Isolate*>(isolate()), wrappers_to_trace_);
+      wrappers_to_trace_.clear();
+    } else if (!only_process_harmony_weak_collections) {
       isolate()->global_handles()->IterateObjectGroups(
           visitor, &IsUnmarkedHeapObjectWithHeap);
       MarkImplicitRefGroups(&MarkCompactMarkingVisitor::MarkObject);
     }
     ProcessWeakCollections();
     work_to_do = !marking_deque_.IsEmpty();
     ProcessMarkingDeque();
   }
 }
 
-
 void MarkCompactCollector::ProcessTopOptimizedFrame(ObjectVisitor* visitor) {
   for (StackFrameIterator it(isolate(), isolate()->thread_local_top());
        !it.done(); it.Advance()) {
     if (it.frame()->type() == StackFrame::JAVA_SCRIPT) {
       return;
     }
     if (it.frame()->type() == StackFrame::OPTIMIZED) {
       Code* code = it.frame()->LookupCode();
       if (!code->CanDeoptAt(it.frame()->pc())) {
         Code::BodyDescriptor::IterateBody(code, visitor);
@@ skipping 78 matching lines @@
 void MarkingDeque::Uninitialize(bool aborting) {
   if (!aborting) {
     DCHECK(IsEmpty());
     DCHECK(!overflowed_);
   }
   DCHECK(in_use_);
   top_ = bottom_ = 0xdecbad;
   in_use_ = false;
 }
 
+void MarkCompactCollector::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
+  DCHECK_NOT_NULL(tracer);
+  CHECK_NULL(embedder_heap_tracer_);
+  embedder_heap_tracer_ = tracer;
+}
+
+void MarkCompactCollector::TracePossibleWrapper(JSObject* js_object) {
+  DCHECK(js_object->WasConstructedFromApiFunction());
+  if (js_object->GetInternalFieldCount() >= 2 &&
+      js_object->GetInternalField(0) != heap_->undefined_value() &&
+      js_object->GetInternalField(1) != heap_->undefined_value()) {
+    wrappers_to_trace().push_back(std::pair<void*, void*>(
+        reinterpret_cast<void*>(js_object->GetInternalField(0)),
+        reinterpret_cast<void*>(js_object->GetInternalField(1))));
+  }
+}
+
+void MarkCompactCollector::RegisterExternallyReferencedObject(Object** object) {
+  DCHECK(in_use());
+  HeapObject* heap_object = HeapObject::cast(*object);
+  DCHECK(heap_->Contains(heap_object));
+  MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
+  MarkObject(heap_object, mark_bit);
+}
 
 void MarkCompactCollector::MarkLiveObjects() {
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK);
   double start_time = 0.0;
   if (FLAG_print_cumulative_gc_stat) {
     start_time = heap_->MonotonicallyIncreasingTimeInMs();
   }
   // The recursive GC marker detects when it is nearing stack overflow,
   // and switches to a different marking system.  JS interrupts interfere
   // with the C stack limit check.
@@ skipping 36 matching lines @@
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WEAK_CLOSURE);
 
     // The objects reachable from the roots are marked, yet unreachable
     // objects are unmarked.  Mark objects reachable due to host
     // application specific logic or through Harmony weak maps.
     {
       TRACE_GC(heap()->tracer(),
                GCTracer::Scope::MC_MARK_WEAK_CLOSURE_EPHEMERAL);
+      if (UsingEmbedderHeapTracer()) {
+        embedder_heap_tracer()->TraceRoots(
+            reinterpret_cast<v8::Isolate*>(isolate()));
+      }
       ProcessEphemeralMarking(&root_visitor, false);
       ProcessMarkingDeque();
     }
 
     // The objects reachable from the roots, weak maps or object groups
     // are marked. Objects pointed to only by weak global handles cannot be
     // immediately reclaimed. Instead, we have to mark them as pending and mark
     // objects reachable from them.
     //
     // First we identify nonlive weak handles and mark them as pending
@@ skipping 16 matching lines @@
 
     // Repeat Harmony weak maps marking to mark unmarked objects reachable from
     // the weak roots we just marked as pending destruction.
     //
     // We only process harmony collections, as all object groups have been fully
     // processed and no weakly reachable node can discover new objects groups.
     {
       TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WEAK_CLOSURE_HARMONY);
       ProcessEphemeralMarking(&root_visitor, true);
       ProcessMarkingDeque();
+      if (UsingEmbedderHeapTracer()) {
+        embedder_heap_tracer()->ClearTracingMarks(
+            reinterpret_cast<v8::Isolate*>(isolate()));
+      }
     }
   }
 
   if (FLAG_print_cumulative_gc_stat) {
     heap_->tracer()->AddMarkingTime(heap_->MonotonicallyIncreasingTimeInMs() -
                                     start_time);
   }
   if (FLAG_track_gc_object_stats) {
     if (FLAG_trace_gc_object_stats) {
       heap()->object_stats_->TraceObjectStats();
@@ skipping 1622 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(host);
     if (Marking::IsBlack(mark_bit)) {
       RelocInfo rinfo(isolate(), pc, RelocInfo::CODE_TARGET, 0, host);
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8