Introduce api for incremental wrapper tracing

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 2105 matching lines @@
 }
 
 // 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) {
   DCHECK(marking_deque_.IsEmpty() && !marking_deque_.overflowed());
   bool work_to_do = true;
   while (work_to_do) {
     if (UsingEmbedderHeapTracer()) {
-      embedder_heap_tracer()->TraceWrappersFrom(wrappers_to_trace_);
-      wrappers_to_trace_.clear();
+      RegisterWrappersWithEmbedderHeapTracer();
+      embedder_heap_tracer()->AdvanceTracing(
+          0, EmbedderHeapTracer::AdvanceTracingActions(
+                 EmbedderHeapTracer::ForceCompletionAction::FORCE_COMPLETION));
     }
     if (!only_process_harmony_weak_collections) {
       isolate()->global_handles()->IterateObjectGroups(
           visitor, &IsUnmarkedHeapObjectWithHeap);
       MarkImplicitRefGroups(&MarkCompactMarkingVisitor::MarkObject);
     }
     ProcessWeakCollections();
     work_to_do = !marking_deque_.IsEmpty();
     ProcessMarkingDeque();
   }
@@ skipping 96 matching lines @@
   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::RegisterWrappersWithEmbedderHeapTracer() {
+  DCHECK(UsingEmbedderHeapTracer());
+  if (wrappers_to_trace_.empty()) {
+    return;
+  }
+  embedder_heap_tracer()->RegisterV8References(wrappers_to_trace_);
+  wrappers_to_trace_.clear();
+}
+
 void MarkCompactCollector::TracePossibleWrapper(JSObject* js_object) {
   DCHECK(js_object->WasConstructedFromApiFunction());
   if (js_object->GetInternalFieldCount() >= 2 &&
       js_object->GetInternalField(0) &&
       js_object->GetInternalField(0) != heap_->undefined_value() &&
       js_object->GetInternalField(1) != heap_->undefined_value()) {
     DCHECK(reinterpret_cast<intptr_t>(js_object->GetInternalField(0)) % 2 == 0);
-    wrappers_to_trace().push_back(std::pair<void*, void*>(
+    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);
@@ skipping 1723 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