Implemented an averaging object histogram in the vm.

runtime/vm/isolate.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/thread.h"
@@ skipping 28 matching lines @@
 class RawMint;
 class RawObject;
 class RawInteger;
 class RawError;
 class Simulator;
 class StackResource;
 class StackZone;
 class StubCode;
 class RawFloat32x4;
 class RawUint32x4;
+class ObjectHistogram;
 
 
 // Used by the deoptimization infrastructure to defer allocation of unboxed
 // objects until frame is fully rewritten and GC is safe.
 // Describes a stack slot that should be populated with a reference to the
 // materialized object.
 class DeferredSlot {
  public:
   DeferredSlot(RawInstance** slot, DeferredSlot* next)
       : slot_(slot), next_(next) { }
@@ skipping 165 matching lines @@
   static inline Isolate* Current() {
     return reinterpret_cast<Isolate*>(Thread::GetThreadLocal(isolate_key));
   }
 
   static void SetCurrent(Isolate* isolate);
 
   static void InitOnce();
   static Isolate* Init(const char* name_prefix);
   void Shutdown();
 
+  // Register a newly introduced class.
+  void RegisterClass(const Class& cls);
+
   // Visit all object pointers.
   void VisitObjectPointers(ObjectPointerVisitor* visitor,
                            bool visit_prologue_weak_persistent_handles,
                            bool validate_frames);
 
   // Visits weak object pointers.
   void VisitWeakPersistentHandles(HandleVisitor* visit,
                                   bool visit_prologue_weak_persistent_handles);
 
   StoreBuffer* store_buffer() { return &store_buffer_; }
   static intptr_t store_buffer_offset() {
     return OFFSET_OF(Isolate, store_buffer_);
   }
 
   ClassTable* class_table() { return &class_table_; }
   static intptr_t class_table_offset() {
     return OFFSET_OF(Isolate, class_table_);
   }
 
+  ObjectHistogram* object_histogram() { return object_histogram_; }
+
   MegamorphicCacheTable* megamorphic_cache_table() {
     return &megamorphic_cache_table_;
   }
 
   Dart_MessageNotifyCallback message_notify_callback() const {
     return message_notify_callback_;
   }
   void set_message_notify_callback(Dart_MessageNotifyCallback value) {
     message_notify_callback_ = value;
   }
@@ skipping 365 matching lines @@
   intptr_t deopt_frame_copy_size_;
   DeferredSlot* deferred_boxes_;
   DeferredSlot* deferred_object_refs_;
 
   intptr_t deferred_objects_count_;
   DeferredObject** deferred_objects_;
 
   // Status support.
   char* stacktrace_;
   intptr_t stack_frame_index_;
+  ObjectHistogram* object_histogram_;
 
   static Dart_IsolateCreateCallback create_callback_;
   static Dart_IsolateInterruptCallback interrupt_callback_;
   static Dart_IsolateUnhandledExceptionCallback unhandled_exception_callback_;
   static Dart_IsolateShutdownCallback shutdown_callback_;
   static Dart_FileOpenCallback file_open_callback_;
   static Dart_FileReadCallback file_read_callback_;
   static Dart_FileWriteCallback file_write_callback_;
   static Dart_FileCloseCallback file_close_callback_;
   static Dart_IsolateInterruptCallback vmstats_callback_;
@@ skipping 109 matching lines @@
 
  private:
   Isolate::IsolateRunState saved_state_;
 
   DISALLOW_COPY_AND_ASSIGN(IsolateRunStateManager);
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_