Implement a heap profiler for the Dart managed heap.

runtime/vm/raw_object.h

 // Copyright (c) 2012, 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_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/token.h"
@@ skipping 325 matching lines @@
   intptr_t SizeFromClass() const;
 
   intptr_t GetClassId() const {
     uword tags = ptr()->tags_;
     return ClassIdTag::decode(tags);
   }
 
   friend class Api;
   friend class Array;
   friend class Heap;
+  friend class HeapProfiler;
   friend class MarkingVisitor;
   friend class Object;
   friend class RawInstructions;
   friend class SnapshotReader;
   friend class SnapshotWriter;
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(RawObject);
 };
 
@@ skipping 24 matching lines @@
   RawFunction* signature_function_;  // Associated function for signature class.
   RawArray* functions_cache_;  // See class FunctionsCache.
   RawArray* constants_;  // Canonicalized values of this class.
   RawArray* canonical_types_;  // Canonicalized types of this class.
   RawCode* allocation_stub_;  // Stub code for allocation of instances.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->allocation_stub_);
   }
 
   cpp_vtable handle_vtable_;
-  intptr_t instance_size_;
+  intptr_t instance_size_;  // Size if fixed length or 0 if variable length.
   ObjectKind instance_kind_;
   intptr_t id_;  // Class Id, also index in the class table.
   intptr_t type_arguments_instance_field_offset_;  // May be kNoTypeArguments.
-  intptr_t next_field_offset_;  // Offset of then next instance field.
+  intptr_t next_field_offset_;  // Offset of the next instance field.
   intptr_t num_native_fields_;  // Number of native fields in class.
   intptr_t token_index_;
   int8_t class_state_;  // Of type ClassState.
   bool is_const_;
   bool is_interface_;
 
+  friend class HeapProfiler;
   friend class Object;
   friend class RawInstance;
   friend class RawInstructions;
   friend RawClass* AllocateFakeClass();
   friend class SnapshotReader;
 };
 
 
 class RawUnresolvedClass : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(UnresolvedClass);
@@ skipping 72 matching lines @@
   RawAbstractTypeArguments* instantiator_type_arguments_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->instantiator_type_arguments_);
   }
 };
 
 
 class RawAbstractTypeArguments : public RawObject {
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(AbstractTypeArguments);
+
+  friend class HeapProfiler;
 };
 
 
 class RawTypeArguments : public RawAbstractTypeArguments {
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(TypeArguments);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->length_);
   }
@@ skipping 80 matching lines @@
   RawString* name_;
   RawClass* owner_;
   RawAbstractType* type_;
   RawInstance* value_;  // Offset for instance and value for static fields.
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->value_); }
 
   intptr_t token_index_;
   bool is_static_;
   bool is_final_;
   bool has_initializer_;
+
+  friend class HeapProfiler;
 };
 
 
 class RawLiteralToken : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(LiteralToken);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->literal_);
   }
   RawString* literal_;  // Literal characters as they appear in source text.
@@ skipping 398 matching lines @@
 
 
 class RawString : public RawInstance {
   RAW_HEAP_OBJECT_IMPLEMENTATION(String);
 
  protected:
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->length_); }
   RawSmi* length_;
   RawSmi* hash_;
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->hash_); }
+
+  friend class HeapProfiler;
 };
 
 
 class RawOneByteString : public RawString {
   RAW_HEAP_OBJECT_IMPLEMENTATION(OneByteString);
 
   // Variable length data follows here.
   uint8_t data_[0];
 
+  friend class HeapProfiler;
   friend class SnapshotReader;
 };
 
 
 class RawTwoByteString : public RawString {
   RAW_HEAP_OBJECT_IMPLEMENTATION(TwoByteString);
 
   // Variable length data follows here.
   uint16_t data_[0];
 
+  friend class HeapProfiler;
   friend class SnapshotReader;
 };
 
 
 class RawFourByteString : public RawString {
   RAW_HEAP_OBJECT_IMPLEMENTATION(FourByteString);
 
   // Variable length data follows here.
   uint32_t data_[0];
 
+  friend class HeapProfiler;
   friend class SnapshotReader;
 };
 
 
 template<typename T>
 class ExternalStringData {
  public:
   ExternalStringData(const T* data, void* peer, Dart_PeerFinalizer callback) :
       data_(data), peer_(peer), callback_(callback) {
   }
@@ skipping 53 matching lines @@
   RawSmi* length_;
   // Variable length data follows here.
   RawObject** data() {
     uword address_of_length = reinterpret_cast<uword>(&length_);
     return reinterpret_cast<RawObject**>(address_of_length + kWordSize);
   }
   RawObject** to(intptr_t length) {
     return reinterpret_cast<RawObject**>(&ptr()->data()[length - 1]);
   }
 
+  friend class GrowableObjectArray;
+  friend class HeapProfiler;
   friend class RawCode;
   friend class RawImmutableArray;
   friend class SnapshotReader;
-  friend class GrowableObjectArray;
 };
 
 
 class RawImmutableArray : public RawArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(ImmutableArray);
 
   friend class SnapshotReader;
 };
 
 
@@ skipping 14 matching lines @@
 };
 
 
 class RawByteArray : public RawInstance {
   RAW_HEAP_OBJECT_IMPLEMENTATION(ByteArray);
 
  protected:
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->length_); }
   RawSmi* length_;
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->length_); }
+
+  friend class HeapProfiler;
 };
 
 
 class RawInt8Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Int8Array);
 
   // Variable length data follows here.
   int8_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawUint8Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Uint8Array);
 
   // Variable length data follows here.
   uint8_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawInt16Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Int16Array);
 
   // Variable length data follows here.
   int16_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawUint16Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Uint16Array);
 
   // Variable length data follows here.
   uint16_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawInt32Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Int32Array);
 
   // Variable length data follows here.
   int32_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawUint32Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Uint32Array);
 
   // Variable length data follows here.
   uint32_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawInt64Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Int64Array);
 
   // Variable length data follows here.
   int64_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawUint64Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Uint64Array);
 
   // Variable length data follows here.
   uint64_t data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawFloat32Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Float32Array);
 
   // Variable length data follows here.
   float data_[0];
+
+  friend class HeapProfiler;
 };
 
 
 class RawFloat64Array: public RawByteArray {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Float64Array);
 
   // Variable length data follows here.
   double data_[0];
+
+  friend class HeapProfiler;

[turnidge, 2012/06/12 17:02:19]

I'm wondering if it makes sense to add this friend decl to one of the macros. 
What do you think?

[cshapiro, 2012/06/14 00:08:36]

I think that is a good idea.  I have pulled this up into a HEAP_PROFILER_SUPPORT
macro.  It cleans up the diff nicely.

 };
 
 
 template<typename T>
 class ExternalByteArrayData {
  public:
   ExternalByteArrayData(T* data,
                         void* peer,
                         Dart_PeerFinalizer callback) :
       data_(data), peer_(peer), callback_(callback) {
@@ skipping 257 matching lines @@
          kExternalUint64Array == kByteArray + 18 &&
          kExternalFloat32Array == kByteArray + 19 &&
          kExternalFloat64Array == kByteArray + 20 &&
          kClosure == kByteArray + 21);
   return (index >= kByteArray && index <= kClosure);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_