Phantom references support internal fields

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 400 matching lines @@
   V8_INLINE Local<T> Get(Isolate* isolate);
   V8_INLINE bool IsEmpty() { return index_ == kInitialValue; }
   template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
 
  private:
   static const int kInitialValue = -1;
   int index_;
 };
 
 
+template<class T>
+class CallbackData {
+ public:
+  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
+  V8_INLINE T* GetParameter() const { return parameter_; }
+
+ protected:
+  CallbackData(Isolate* isolate, T* parameter)
+    : isolate_(isolate), parameter_(parameter) { }
+
+ private:
+  Isolate* isolate_;
+  T* parameter_;
+};
+
 template<class T, class P>
-class WeakCallbackData {
+class WeakCallbackData : public CallbackData<P> {
  public:
   typedef void (*Callback)(const WeakCallbackData<T, P>& data);
 
-  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
   V8_INLINE Local<T> GetValue() const { return handle_; }
-  V8_INLINE P* GetParameter() const { return parameter_; }
 
  private:
   friend class internal::GlobalHandles;
   WeakCallbackData(Isolate* isolate, Local<T> handle, P* parameter)
-    : isolate_(isolate), handle_(handle), parameter_(parameter) { }
-  Isolate* isolate_;
+    : CallbackData<P>(isolate, parameter), handle_(handle) { }
   Local<T> handle_;
-  P* parameter_;
 };
 
 
+template<typename T>
+class PhantomCallbackData : public CallbackData<T> {
+ public:
+  typedef void (*Callback)(const PhantomCallbackData<T>& data);
+
+  V8_INLINE void* GetInternalField1() const { return internal_field1_; }
+  V8_INLINE void* GetInternalField2() const { return internal_field2_; }
+
+ private:
+  friend class internal::GlobalHandles;
+  PhantomCallbackData(Isolate* isolate, void* internalField1, void* internalField2)
+    : CallbackData<T>(isolate, NULL),
+      internal_field1_(internalField1),
+      internal_field2_(internalField2) { }
+  PhantomCallbackData(Isolate* isolate, T* parameter)
+    : CallbackData<T>(isolate, parameter),
+      internal_field1_(NULL),
+      internal_field2_(NULL) { }
+  void* internal_field1_;
+  void* internal_field2_;
+};
+
+
 /**
  * An object reference that is independent of any handle scope.  Where
  * a Local handle only lives as long as the HandleScope in which it was
  * allocated, a PersistentBase handle remains valid until it is explicitly
  * disposed.
  *
  * A persistent handle contains a reference to a storage cell within
  * the v8 engine which holds an object value and which is updated by
  * the garbage collector whenever the object is moved.  A new storage
  * cell can be created using the constructor or PersistentBase::Reset and
@@ skipping 14 matching lines @@
   template <class S>
   V8_INLINE void Reset(Isolate* isolate, const Handle<S>& other);
 
   /**
    * If non-empty, destroy the underlying storage cell
    * and create a new one with the contents of other if other is non empty
    */
   template <class S>
   V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
 
-  V8_INLINE bool IsEmpty() const { return val_ == 0; }
+  V8_INLINE bool IsEmpty() const { return val_ == NULL; }
+  V8_INLINE void Empty() { val_ = NULL; }
 
   template <class S>
   V8_INLINE bool operator==(const PersistentBase<S>& that) const {
     internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
     internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
     if (a == 0) return b == 0;
     if (b == 0) return false;
     return *a == *b;
   }
 
@@ skipping 30 matching lines @@
   V8_INLINE void SetWeak(
       P* parameter,
       typename WeakCallbackData<S, P>::Callback callback);
 
   // Phantom persistents work like weak persistents, except that the pointer to
   // the object being collected is not available in the finalization callback.
   // This enables the garbage collector to collect the object and any objects
   // it references transitively in one GC cycle.
   template <typename P>
   V8_INLINE void SetPhantom(P* parameter,
-                            typename WeakCallbackData<T, P>::Callback callback);
+                            typename PhantomCallbackData<P>::Callback callback);
 
-  template <typename S, typename P>
-  V8_INLINE void SetPhantom(P* parameter,
-                            typename WeakCallbackData<S, P>::Callback callback);
+  V8_INLINE void SetPhantom(typename PhantomCallbackData<void>::Callback callback,
+                            int internalFieldOffset1, int internalFieldOffset2);
 
   template<typename P>
   V8_INLINE P* ClearWeak();
 
   // TODO(dcarney): remove this.
   V8_INLINE void ClearWeak() { ClearWeak<void>(); }
 
   /**
    * Marks the reference to this object independent. Garbage collector is free
    * to ignore any object groups containing this object. Weak callback for an
@@ skipping 1936 matching lines @@
   Local<String> ObjectProtoToString();
 
   /**
    * Returns the name of the function invoked as a constructor for this object.
    */
   Local<String> GetConstructorName();
 
   /** Gets the number of internal fields for this Object. */
   int InternalFieldCount();
 
+  static const int kNoInternalFieldIndex = -1;
+
   /** Same as above, but works for Persistents */
   V8_INLINE static int InternalFieldCount(
       const PersistentBase<Object>& object) {
     return object.val_->InternalFieldCount();
   }
 
   /** Gets the value from an internal field. */
   V8_INLINE Local<Value> GetInternalField(int index);
 
   /** Sets the value in an internal field. */
@@ skipping 2984 matching lines @@
  private:
   V8();
 
   enum WeakHandleType { PhantomHandle, NonphantomHandle };
 
   static internal::Object** GlobalizeReference(internal::Isolate* isolate,
                                                internal::Object** handle);
   static internal::Object** CopyPersistent(internal::Object** handle);
   static void DisposeGlobal(internal::Object** global_handle);
   typedef WeakCallbackData<Value, void>::Callback WeakCallback;
+  typedef PhantomCallbackData<void>::Callback PhantomCallback;
   static void MakeWeak(internal::Object** global_handle, void* data,
-                       WeakCallback weak_callback, WeakHandleType phantom);
+                       WeakCallback weak_callback);
+  static void MakePhantom(
+      internal::Object** global_handle, void* data,
+      PhantomCallback weak_callback,
+      int internal_field_index1 = Object::kNoInternalFieldIndex,
+      int internal_field_index2 = Object::kNoInternalFieldIndex);
   static void* ClearWeak(internal::Object** global_handle);
   static void Eternalize(Isolate* isolate,
                          Value* handle,
                          int* index);
   static Local<Value> GetEternal(Isolate* isolate, int index);
 
   template <class T> friend class Handle;
   template <class T> friend class Local;
   template <class T> friend class Eternal;
   template <class T> friend class PersistentBase;
@@ skipping 588 matching lines @@
   static const int kTrueValueRootIndex = 8;
   static const int kFalseValueRootIndex = 9;
   static const int kEmptyStringRootIndex = 154;
 
   // The external allocation limit should be below 256 MB on all architectures
   // to avoid that resource-constrained embedders run low on memory.
   static const int kExternalAllocationLimit = 192 * 1024 * 1024;
 
   static const int kNodeClassIdOffset = 1 * kApiPointerSize;
   static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
-  static const int kNodeStateMask = 0xf;
+  static const int kNodeStateMask = 0x7;
   static const int kNodeStateIsWeakValue = 2;
   static const int kNodeStateIsPendingValue = 3;
   static const int kNodeStateIsNearDeathValue = 4;
-  static const int kNodeIsIndependentShift = 4;
-  static const int kNodeIsPartiallyDependentShift = 5;
+  static const int kNodeIsIndependentShift = 3;
+  static const int kNodeIsPartiallyDependentShift = 4;
 
   static const int kJSObjectType = 0xbd;
   static const int kFirstNonstringType = 0x80;
   static const int kOddballType = 0x83;
   static const int kForeignType = 0x88;
 
   static const int kUndefinedOddballKind = 5;
   static const int kNullOddballKind = 3;
 
   static const uint32_t kNumIsolateDataSlots = 4;
@@ skipping 237 matching lines @@
 
 
 template <class T>
 template <typename S, typename P>
 void PersistentBase<T>::SetWeak(
     P* parameter,
     typename WeakCallbackData<S, P>::Callback callback) {
   TYPE_CHECK(S, T);
   typedef typename WeakCallbackData<Value, void>::Callback Callback;
   V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
-               reinterpret_cast<Callback>(callback), V8::NonphantomHandle);
+               reinterpret_cast<Callback>(callback));
 }
 
 
 template <class T>
 template <typename P>
 void PersistentBase<T>::SetWeak(
     P* parameter,
     typename WeakCallbackData<T, P>::Callback callback) {
   SetWeak<T, P>(parameter, callback);
 }
 
 
 template <class T>
-template <typename S, typename P>
-void PersistentBase<T>::SetPhantom(
-    P* parameter, typename WeakCallbackData<S, P>::Callback callback) {
-  TYPE_CHECK(S, T);
-  typedef typename WeakCallbackData<Value, void>::Callback Callback;
-  V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
-               reinterpret_cast<Callback>(callback), V8::PhantomHandle);
-}
-
-
-template <class T>
 template <typename P>
 void PersistentBase<T>::SetPhantom(
-    P* parameter, typename WeakCallbackData<T, P>::Callback callback) {
-  SetPhantom<T, P>(parameter, callback);
+    P* parameter, typename PhantomCallbackData<P>::Callback callback) {
+  typedef typename PhantomCallbackData<void>::Callback Callback;
+  V8::MakePhantom(reinterpret_cast<internal::Object**>(this->val_), parameter,
+                  reinterpret_cast<Callback>(callback),
+                  Object::kNoInternalFieldIndex, Object::kNoInternalFieldIndex);
 }
 
 
+template <class T>
+void PersistentBase<T>::SetPhantom(
+    typename PhantomCallbackData<void>::Callback callback,
+    int internal_field_index1, int internal_field_index2) {
+  typedef typename PhantomCallbackData<void>::Callback Callback;
+  V8::MakePhantom(reinterpret_cast<internal::Object**>(this->val_), 0,
+                  reinterpret_cast<Callback>(callback), internal_field_index1,
+                  internal_field_index2);
+}
+
+
 template <class T>
 template <typename P>
 P* PersistentBase<T>::ClearWeak() {
   return reinterpret_cast<P*>(
     V8::ClearWeak(reinterpret_cast<internal::Object**>(this->val_)));
 }
 
 
 template <class T>
 void PersistentBase<T>::MarkIndependent() {
@@ skipping 973 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_