Add an API to V8 to get simple heap statistics.

Review URL: http://codereview.chromium.org/261037

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3089 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -2102,6 +2102,29 @@ enum ProfilerModules {
 };
 
 
+/**
+ * Collection of V8 heap information.
+ *
+ * Instances of this class can be passed to v8::V8::HeapStatistics to
+ * get heap statistics from V8.
+ */
+class V8EXPORT HeapStatistics {
+ public:
+  HeapStatistics();
+  size_t total_heap_size() { return total_heap_size_; }
+  size_t used_heap_size() { return used_heap_size_; }
+
+ private:
+  void set_total_heap_size(size_t size) { total_heap_size_ = size; }
+  void set_used_heap_size(size_t size) { used_heap_size_ = size; }
+
+  size_t total_heap_size_;
+  size_t used_heap_size_;
+
+  friend class V8;
+};
+
+
 /**
  * Container class for static utility functions.
  */
@@ -2352,6 +2375,10 @@ class V8EXPORT V8 {
    */
   static bool Dispose();
 
+  /**
+   * Get statistics about the heap memory usage.
+   */
+  static void GetHeapStatistics(HeapStatistics* heap_statistics);
 
   /**
    * Optional notification that the embedder is idle.

src/api.cc

@@ -2611,6 +2611,15 @@ bool v8::V8::Dispose() {
 }
 
 
+HeapStatistics::HeapStatistics(): total_heap_size_(0), used_heap_size_(0) { }
+
+
+void v8::V8::GetHeapStatistics(HeapStatistics* heap_statistics) {
+  heap_statistics->set_total_heap_size(i::Heap::CommittedMemory());
+  heap_statistics->set_used_heap_size(i::Heap::SizeOfObjects());
+}
+
+
 bool v8::V8::IdleNotification() {
   // Returning true tells the caller that it need not
   // continue to call IdleNotification.

src/heap.cc

@@ -127,6 +127,19 @@ int Heap::Capacity() {
 }
 
 
+int Heap::CommittedMemory() {
+  if (!HasBeenSetup()) return 0;
+
+  return new_space_.CommittedMemory() +
+      old_pointer_space_->CommittedMemory() +
+      old_data_space_->CommittedMemory() +
+      code_space_->CommittedMemory() +
+      map_space_->CommittedMemory() +
+      cell_space_->CommittedMemory() +
+      lo_space_->Size();
+}
+
+
 int Heap::Available() {
   if (!HasBeenSetup()) return 0;
 
@@ -222,19 +235,34 @@ void Heap::ReportStatisticsBeforeGC() {
 void Heap::PrintShortHeapStatistics() {
   if (!FLAG_trace_gc_verbose) return;
   PrintF("Memory allocator,   used: %8d, available: %8d\n",
-         MemoryAllocator::Size(), MemoryAllocator::Available());
+         MemoryAllocator::Size(),
+         MemoryAllocator::Available());
   PrintF("New space,          used: %8d, available: %8d\n",
-         Heap::new_space_.Size(), new_space_.Available());
-  PrintF("Old pointers,       used: %8d, available: %8d\n",
-         old_pointer_space_->Size(), old_pointer_space_->Available());
-  PrintF("Old data space,     used: %8d, available: %8d\n",
-         old_data_space_->Size(), old_data_space_->Available());
-  PrintF("Code space,         used: %8d, available: %8d\n",
-         code_space_->Size(), code_space_->Available());
-  PrintF("Map space,          used: %8d, available: %8d\n",
-         map_space_->Size(), map_space_->Available());
+         Heap::new_space_.Size(),
+         new_space_.Available());
+  PrintF("Old pointers,       used: %8d, available: %8d, waste: %8d\n",
+         old_pointer_space_->Size(),
+         old_pointer_space_->Available(),
+         old_pointer_space_->Waste());
+  PrintF("Old data space,     used: %8d, available: %8d, waste: %8d\n",
+         old_data_space_->Size(),
+         old_data_space_->Available(),
+         old_data_space_->Waste());
+  PrintF("Code space,         used: %8d, available: %8d, waste: %8d\n",
+         code_space_->Size(),
+         code_space_->Available(),
+         code_space_->Waste());
+  PrintF("Map space,          used: %8d, available: %8d, waste: %8d\n",
+         map_space_->Size(),
+         map_space_->Available(),
+         map_space_->Waste());
+  PrintF("Cell space,         used: %8d, available: %8d, waste: %8d\n",
+         cell_space_->Size(),
+         cell_space_->Available(),
+         cell_space_->Waste());
   PrintF("Large object space, used: %8d, avaialble: %8d\n",
-         lo_space_->Size(), lo_space_->Available());
+         lo_space_->Size(),
+         lo_space_->Available());
 }
 #endif
 

src/heap.h

@@ -260,6 +260,9 @@ class Heap : public AllStatic {
   // more spaces are needed until it reaches the limit.
   static int Capacity();
 
+  // Returns the amount of memory currently committed for the heap.
+  static int CommittedMemory();
+
   // Returns the available bytes in space w/o growing.
   // Heap doesn't guarantee that it can allocate an object that requires
   // all available bytes. Check MaxHeapObjectSize() instead.

src/spaces.h

@@ -862,6 +862,10 @@ class PagedSpace : public Space {
   // Current capacity without growing (Size() + Available() + Waste()).
   int Capacity() { return accounting_stats_.Capacity(); }
 
+  // Total amount of memory committed for this space.  For paged
+  // spaces this equals the capacity.
+  int CommittedMemory() { return Capacity(); }
+
   // Available bytes without growing.
   int Available() { return accounting_stats_.Available(); }
 
@@ -1252,11 +1256,19 @@ class NewSpace : public Space {
 
   // Return the allocated bytes in the active semispace.
   virtual int Size() { return top() - bottom(); }
+
   // Return the current capacity of a semispace.
   int Capacity() {
     ASSERT(to_space_.Capacity() == from_space_.Capacity());
     return to_space_.Capacity();
   }
+
+  // Return the total amount of memory committed for new space.
+  int CommittedMemory() {
+    if (from_space_.is_committed()) return 2 * Capacity();
+    return Capacity();
+  }
+
   // Return the available bytes without growing in the active semispace.
   int Available() { return Capacity() - Size(); }
 

test/cctest/test-api.cc

@@ -8153,3 +8153,15 @@ TEST(SetResourceConstraintsInThread) {
     CHECK(stack_limit == set_limit);
   }
 }
+
+
+THREADED_TEST(GetHeapStatistics) {
+  v8::HandleScope scope;
+  LocalContext c1;
+  v8::HeapStatistics heap_statistics;
+  CHECK_EQ(heap_statistics.total_heap_size(), 0);
+  CHECK_EQ(heap_statistics.used_heap_size(), 0);
+  v8::V8::GetHeapStatistics(&heap_statistics);
+  CHECK_NE(heap_statistics.total_heap_size(), 0);
+  CHECK_NE(heap_statistics.used_heap_size(), 0);
+}