heap: allow allocation in gc prologue/epilogue

src/heap-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 791 matching lines @@
 }
 
 
 NoWeakObjectVerificationScope::~NoWeakObjectVerificationScope() {
   Isolate* isolate = Isolate::Current();
   isolate->heap()->no_weak_object_verification_scope_depth_--;
 }
 #endif
 
 
+GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) {
+  heap_->gc_callbacks_depth_++;
+}
+
+
+GCCallbacksScope::~GCCallbacksScope() {
+  heap_->gc_callbacks_depth_--;
+}
+
+
+bool GCCallbacksScope::CheckReenter() {
+  return heap_->gc_callbacks_depth_ == 1;
+}
+
+
 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
   for (Object** current = start; current < end; current++) {
     if ((*current)->IsHeapObject()) {
       HeapObject* object = HeapObject::cast(*current);
       CHECK(object->GetIsolate()->heap()->Contains(object));
       CHECK(object->map()->IsMap());
     }
   }
 }
 
@@ skipping 23 matching lines @@
 #ifdef DEBUG
   Isolate* isolate = Isolate::Current();
   isolate->heap()->disallow_allocation_failure_ = old_state_;
 #endif
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_