[heap] Report allocated size of global handles

Report the allocated size of global handles in GetHeapStatistics as
well, not including free handles.

Bug: chromium:1060192
Change-Id: I1aedba36735f897cd8518edbb5ef2261cc348bff
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2093493
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66651}

include/v8.h

@@ -7608,6 +7608,7 @@ class V8_EXPORT HeapStatistics {
   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_global_handles_size() { return used_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_; }
@@ -7636,6 +7637,7 @@ class V8_EXPORT HeapStatistics {
   size_t number_of_native_contexts_;
   size_t number_of_detached_contexts_;
   size_t total_global_handles_size_;
+  size_t used_global_handles_size_;
 
   friend class V8;
   friend class Isolate;

src/api/api.cc

@@ -8515,6 +8515,7 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->total_available_size_ = heap->Available();
   heap_statistics->used_heap_size_ = heap->SizeOfObjects();
   heap_statistics->total_global_handles_size_ = heap->TotalGlobalHandlesSize();
+  heap_statistics->used_global_handles_size_ = heap->UsedGlobalHandlesSize();
 
 #ifndef V8_SHARED_RO_HEAP
   i::ReadOnlySpace* ro_space = heap->read_only_space();

src/handles/global-handles.cc

@@ -187,6 +187,7 @@ class GlobalHandles::NodeSpace final {
   iterator end() { return iterator(nullptr); }
 
   size_t TotalSize() const { return blocks_ * sizeof(NodeType) * kBlockSize; }
+  size_t handles_count() const { return handles_count_; }
 
  private:
   void PutNodesOnFreeList(BlockType* block);
@@ -197,6 +198,7 @@ class GlobalHandles::NodeSpace final {
   BlockType* first_used_block_ = nullptr;
   NodeType* first_free_ = nullptr;
   size_t blocks_ = 0;
+  size_t handles_count_ = 0;
 };
 
 template <class NodeType>
@@ -225,7 +227,7 @@ NodeType* GlobalHandles::NodeSpace<NodeType>::Acquire(Object object) {
     block->ListAdd(&first_used_block_);
   }
   global_handles_->isolate()->counters()->global_handles()->Increment();
-  global_handles_->handles_count_++;
+  handles_count_++;
   DCHECK(node->IsInUse());
   return node;
 }
@@ -257,7 +259,7 @@ void GlobalHandles::NodeSpace<NodeType>::Free(NodeType* node) {
     block->ListRemove(&first_used_block_);
   }
   global_handles_->isolate()->counters()->global_handles()->Decrement();
-  global_handles_->handles_count_--;
+  handles_count_--;
 }
 
 template <class Child>
@@ -883,6 +885,15 @@ size_t GlobalHandles::TotalSize() const {
   return regular_nodes_->TotalSize() + traced_nodes_->TotalSize();
 }
 
+size_t GlobalHandles::UsedSize() const {
+  return regular_nodes_->handles_count() * sizeof(Node) +
+         traced_nodes_->handles_count() * sizeof(TracedNode);
+}
+
+size_t GlobalHandles::handles_count() const {
+  return regular_nodes_->handles_count() + traced_nodes_->handles_count();
+}
+
 void GlobalHandles::SetStackStart(void* stack_start) {
   on_stack_nodes_->SetStackStart(stack_start);
 }

src/handles/global-handles.h

@@ -177,9 +177,10 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
   Isolate* isolate() const { return isolate_; }
 
   size_t TotalSize() const;
+  size_t UsedSize() const;
 
   // Number of global handles.
-  size_t handles_count() const { return handles_count_; }
+  size_t handles_count() const;
 
   size_t GetAndResetGlobalHandleResetCount() {
     size_t old = number_of_phantom_handle_resets_;
@@ -239,8 +240,6 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
   std::vector<TracedNode*> traced_young_nodes_;
   std::unique_ptr<OnStackTracedNodeSpace> on_stack_nodes_;
 
-  // Field always containing the number of handles to global objects.
-  size_t handles_count_ = 0;
   size_t number_of_phantom_handle_resets_ = 0;
 
   std::vector<std::pair<Node*, PendingPhantomCallback>>

src/heap/heap.cc

@@ -871,6 +871,10 @@ size_t Heap::TotalGlobalHandlesSize() {
   return isolate_->global_handles()->TotalSize();
 }
 
+size_t Heap::UsedGlobalHandlesSize() {
+  return isolate_->global_handles()->UsedSize();
+}
+
 // static
 const char* Heap::GetSpaceName(AllocationSpace space) {
   switch (space) {

src/heap/heap.h

@@ -1201,6 +1201,9 @@ class Heap {
   // Returns size of all global handles in the heap.
   V8_EXPORT_PRIVATE size_t TotalGlobalHandlesSize();
 
+  // Returns size of all allocated/used global handles in the heap.
+  V8_EXPORT_PRIVATE size_t UsedGlobalHandlesSize();
+
   void UpdateSurvivalStatistics(int start_new_space_size);
 
   inline void IncrementPromotedObjectsSize(size_t object_size) {

test/cctest/test-global-handles.cc

@@ -678,9 +678,13 @@ TEST(TotalSizeRegularNode) {
 
   v8::Global<v8::Object>* global = new Global<v8::Object>();
   CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
   ConstructJSObject(isolate, global);
   CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_GT(i_isolate->global_handles()->UsedSize(), 0);
   delete global;
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
 }
 
 TEST(TotalSizeTracedNode) {
@@ -691,9 +695,13 @@ TEST(TotalSizeTracedNode) {
 
   v8::TracedGlobal<v8::Object>* global = new TracedGlobal<v8::Object>();
   CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
   ConstructJSObject(isolate, global);
   CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_GT(i_isolate->global_handles()->UsedSize(), 0);
   delete global;
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
 }
 
 }  // namespace internal