[heap] Report total size of global handles

Report the total size of global handles in GetHeapStatistics as well.
This size includes used and free global handles.

Change-Id: I08c0647d993a810a37ae9f332732de9551b5ea8d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2083020
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66562}

include/v8.h

@@ -7578,6 +7578,7 @@ class V8_EXPORT HeapStatistics {
   size_t total_heap_size_executable() { return total_heap_size_executable_; }
   size_t total_physical_size() { return total_physical_size_; }
   size_t total_available_size() { return total_available_size_; }
+  size_t total_global_handles_size() { return total_global_handles_size_; }
   size_t used_heap_size() { return used_heap_size_; }
   size_t heap_size_limit() { return heap_size_limit_; }
   size_t malloced_memory() { return malloced_memory_; }
@@ -7605,6 +7606,7 @@ class V8_EXPORT HeapStatistics {
   bool does_zap_garbage_;
   size_t number_of_native_contexts_;
   size_t number_of_detached_contexts_;
+  size_t total_global_handles_size_;
 
   friend class V8;
   friend class Isolate;

src/api/api.cc

@@ -8483,6 +8483,7 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
   heap_statistics->total_available_size_ = heap->Available();
   heap_statistics->used_heap_size_ = heap->SizeOfObjects();
+  heap_statistics->total_global_handles_size_ = heap->TotalGlobalHandlesSize();
 
 #ifndef V8_SHARED_RO_HEAP
   i::ReadOnlySpace* ro_space = heap->read_only_space();

src/handles/global-handles.cc

@@ -186,6 +186,8 @@ class GlobalHandles::NodeSpace final {
   iterator begin() { return iterator(first_used_block_); }
   iterator end() { return iterator(nullptr); }
 
+  size_t TotalSize() const { return blocks_ * sizeof(NodeType) * kBlockSize; }
+
  private:
   void PutNodesOnFreeList(BlockType* block);
   V8_INLINE void Free(NodeType* node);
@@ -194,6 +196,7 @@ class GlobalHandles::NodeSpace final {
   BlockType* first_block_ = nullptr;
   BlockType* first_used_block_ = nullptr;
   NodeType* first_free_ = nullptr;
+  size_t blocks_ = 0;
 };
 
 template <class NodeType>
@@ -210,6 +213,7 @@ template <class NodeType>
 NodeType* GlobalHandles::NodeSpace<NodeType>::Acquire(Object object) {
   if (first_free_ == nullptr) {
     first_block_ = new BlockType(global_handles_, this, first_block_);
+    blocks_++;
     PutNodesOnFreeList(first_block_);
   }
   DCHECK_NOT_NULL(first_free_);
@@ -875,6 +879,10 @@ size_t GlobalHandles::NumberOfOnStackHandlesForTesting() {
   return on_stack_nodes_->NumberOfHandlesForTesting();
 }
 
+size_t GlobalHandles::TotalSize() const {
+  return regular_nodes_->TotalSize() + traced_nodes_->TotalSize();
+}
+
 void GlobalHandles::SetStackStart(void* stack_start) {
   on_stack_nodes_->SetStackStart(stack_start);
 }

src/handles/global-handles.h

@@ -176,6 +176,8 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
 
   Isolate* isolate() const { return isolate_; }
 
+  size_t TotalSize() const;
+
   // Number of global handles.
   size_t handles_count() const { return handles_count_; }
 

src/heap/heap.cc

@@ -867,6 +867,10 @@ size_t Heap::SizeOfObjects() {
   return total;
 }
 
+size_t Heap::TotalGlobalHandlesSize() {
+  return isolate_->global_handles()->TotalSize();
+}
+
 // static
 const char* Heap::GetSpaceName(AllocationSpace space) {
   switch (space) {

src/heap/heap.h

@@ -1195,9 +1195,12 @@ class Heap {
   // all available bytes. Check MaxHeapObjectSize() instead.
   size_t Available();
 
-  // Returns of size of all objects residing in the heap.
+  // Returns size of all objects residing in the heap.
   V8_EXPORT_PRIVATE size_t SizeOfObjects();
 
+  // Returns size of all global handles in the heap.
+  V8_EXPORT_PRIVATE size_t TotalGlobalHandlesSize();
+
   void UpdateSurvivalStatistics(int start_new_space_size);
 
   inline void IncrementPromotedObjectsSize(size_t object_size) {

test/cctest/test-global-handles.cc

@@ -98,6 +98,15 @@ void ConstructJSObject(v8::Isolate* isolate, v8::Global<v8::Object>* global) {
   CHECK(!global->IsEmpty());
 }
 
+void ConstructJSObject(v8::Isolate* isolate,
+                       v8::TracedGlobal<v8::Object>* traced) {
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::Object> object(v8::Object::New(isolate));
+  CHECK(!object.IsEmpty());
+  *traced = v8::TracedGlobal<v8::Object>(isolate, object);
+  CHECK(!traced->IsEmpty());
+}
+
 template <typename HandleContainer>
 void ConstructJSApiObject(v8::Isolate* isolate, v8::Local<v8::Context> context,
                           HandleContainer* flag_and_persistent) {
@@ -667,5 +676,31 @@ TEST(MoveWeakGlobal) {
   InvokeMarkSweep();
 }
 
+TEST(TotalSizeRegularNode) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+  Isolate* i_isolate = CcTest::i_isolate();
+  v8::HandleScope scope(isolate);
+
+  v8::Global<v8::Object>* global = new Global<v8::Object>();
+  CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  ConstructJSObject(isolate, global);
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  delete global;
+}
+
+TEST(TotalSizeTracedNode) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+  Isolate* i_isolate = CcTest::i_isolate();
+  v8::HandleScope scope(isolate);
+
+  v8::TracedGlobal<v8::Object>* global = new TracedGlobal<v8::Object>();
+  CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  ConstructJSObject(isolate, global);
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  delete global;
+}
+
 }  // namespace internal
 }  // namespace v8