Add internal fields to JSArrayBufferViews (JSTypedArray and JSDataView)

In Blink, JSTypedArray and JSDataView objects act as "wrappers" for C++
objects. Wrapping protocol in Blink requires all wrapper JavaScript objects
to have a certain amount of internal fields that Blink uses for
book-keeping (essentially a pointer to C++ object and some type
information). This change adds those internal fields to JSTypedArray and
JSDataView, in a similiar way to how it is done for JSArrayBuffer.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/18695004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15511 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -2377,6 +2377,7 @@ class V8EXPORT Function : public Object {
 };
 
 #ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
 #define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
 #endif
 
@@ -2489,6 +2490,12 @@ class V8EXPORT ArrayBuffer : public Object {
 };
 
 
+#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
+#endif
+
+
 /**
  * A base class for an instance of one of "views" over ArrayBuffer,
  * including TypedArrays and DataView (ES6 draft 15.13).
@@ -2516,6 +2523,9 @@ class V8EXPORT ArrayBufferView : public Object {
 
   V8_INLINE(static ArrayBufferView* Cast(Value* obj));
 
+  static const int kInternalFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+
  private:
   ArrayBufferView();
   static void CheckCast(Value* obj);

src/bootstrapper.cc

@@ -1289,7 +1289,7 @@ Handle<JSFunction> Genesis::InstallTypedArray(
       Builtins::kIllegal, false, true);
 
   Handle<Map> initial_map = isolate()->factory()->NewMap(
-      JS_TYPED_ARRAY_TYPE, JSTypedArray::kSize, elementsKind);
+      JS_TYPED_ARRAY_TYPE, JSTypedArray::kSizeWithInternalFields, elementsKind);
   result->set_initial_map(*initial_map);
   initial_map->set_constructor(*result);
   return result;
@@ -1373,7 +1373,7 @@ void Genesis::InitializeExperimentalGlobal() {
     Handle<JSFunction> data_view_fun =
         InstallFunction(
             global, "DataView", JS_DATA_VIEW_TYPE,
-            JSDataView::kSize,
+            JSDataView::kSizeWithInternalFields,
             isolate()->initial_object_prototype(),
             Builtins::kIllegal, true, true);
     native_context()->set_data_view_fun(*data_view_fun);

src/objects-visiting-inl.h

@@ -136,8 +136,8 @@ int StaticNewSpaceVisitor<StaticVisitor>::VisitJSTypedArray(
       map->GetHeap(),
       HeapObject::RawField(object,
           JSTypedArray::kWeakNextOffset + kPointerSize),
-      HeapObject::RawField(object, JSTypedArray::kSize));
-  return JSTypedArray::kSize;
+      HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields));
+  return JSTypedArray::kSizeWithInternalFields;
 }
 
 
@@ -152,8 +152,8 @@ int StaticNewSpaceVisitor<StaticVisitor>::VisitJSDataView(
       map->GetHeap(),
       HeapObject::RawField(object,
           JSDataView::kWeakNextOffset + kPointerSize),
-      HeapObject::RawField(object, JSDataView::kSize));
-  return JSDataView::kSize;
+      HeapObject::RawField(object, JSDataView::kSizeWithInternalFields));
+  return JSDataView::kSizeWithInternalFields;
 }
 
 
@@ -522,7 +522,7 @@ void StaticMarkingVisitor<StaticVisitor>::VisitJSTypedArray(
       map->GetHeap(),
       HeapObject::RawField(object,
         JSTypedArray::kWeakNextOffset + kPointerSize),
-      HeapObject::RawField(object, JSTypedArray::kSize));
+      HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields));
 }
 
 
@@ -537,7 +537,7 @@ void StaticMarkingVisitor<StaticVisitor>::VisitJSDataView(
       map->GetHeap(),
       HeapObject::RawField(object,
         JSDataView::kWeakNextOffset + kPointerSize),
-      HeapObject::RawField(object, JSDataView::kSize));
+      HeapObject::RawField(object, JSDataView::kSizeWithInternalFields));
 }
 
 

src/objects.h

@@ -8918,6 +8918,9 @@ class JSTypedArray: public JSArrayBufferView {
   static const int kLengthOffset = kViewSize + kPointerSize;
   static const int kSize = kLengthOffset + kPointerSize;
 
+  static const int kSizeWithInternalFields =
+      kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
 };
@@ -8937,6 +8940,9 @@ class JSDataView: public JSArrayBufferView {
 
   static const int kSize = kViewSize;
 
+  static const int kSizeWithInternalFields =
+      kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
 };

src/runtime.cc

@@ -796,6 +796,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_TypedArrayInitialize) {
   CONVERT_ARG_HANDLE_CHECKED(Object, byte_offset_object, 3);
   CONVERT_ARG_HANDLE_CHECKED(Object, byte_length_object, 4);
 
+  ASSERT(holder->GetInternalFieldCount() ==
+      v8::ArrayBufferView::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
+    holder->SetInternalField(i, Smi::FromInt(0));
+  }
+
   ExternalArrayType arrayType;
   size_t elementSize;
   switch (arrayId) {
@@ -1012,6 +1018,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DataViewInitialize) {
   CONVERT_ARG_HANDLE_CHECKED(Object, byte_offset, 2);
   CONVERT_ARG_HANDLE_CHECKED(Object, byte_length, 3);
 
+  ASSERT(holder->GetInternalFieldCount() ==
+      v8::ArrayBufferView::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
+    holder->SetInternalField(i, Smi::FromInt(0));
+  }
+
   holder->set_buffer(*buffer);
   ASSERT(byte_offset->IsNumber());
   ASSERT(

test/cctest/test-api.cc

@@ -2572,6 +2572,14 @@ class ScopedArrayBufferContents {
   const v8::ArrayBuffer::Contents contents_;
 };
 
+template <typename T>
+static void CheckInternalFieldsAreZero(v8::Handle<T> value) {
+  CHECK_EQ(T::kInternalFieldCount, value->InternalFieldCount());
+  for (int i = 0; i < value->InternalFieldCount(); i++) {
+    CHECK_EQ(0, value->GetInternalField(i)->Int32Value());
+  }
+}
+
 
 THREADED_TEST(ArrayBuffer_ApiInternalToExternal) {
   i::FLAG_harmony_array_buffer = true;
@@ -2582,6 +2590,7 @@ THREADED_TEST(ArrayBuffer_ApiInternalToExternal) {
   v8::HandleScope handle_scope(isolate);
 
   Local<v8::ArrayBuffer> ab = v8::ArrayBuffer::New(1024);
+  CheckInternalFieldsAreZero(ab);
   CHECK_EQ(1024, static_cast<int>(ab->ByteLength()));
   CHECK(!ab->IsExternal());
   HEAP->CollectAllGarbage(i::Heap::kNoGCFlags);
@@ -2626,6 +2635,7 @@ THREADED_TEST(ArrayBuffer_JSInternalToExternal) {
                  "u8_a[0] = 0xAA;"
                  "u8_a[1] = 0xFF; u8_a.buffer");
   Local<v8::ArrayBuffer> ab1 = Local<v8::ArrayBuffer>::Cast(result);
+  CheckInternalFieldsAreZero(ab1);
   CHECK_EQ(2, static_cast<int>(ab1->ByteLength()));
   CHECK(!ab1->IsExternal());
   ScopedArrayBufferContents ab1_contents(ab1->Externalize());
@@ -2666,6 +2676,7 @@ THREADED_TEST(ArrayBuffer_External) {
   i::ScopedVector<uint8_t> my_data(100);
   memset(my_data.start(), 0, 100);
   Local<v8::ArrayBuffer> ab3 = v8::ArrayBuffer::New(my_data.start(), 100);
+  CheckInternalFieldsAreZero(ab3);
   CHECK_EQ(100, static_cast<int>(ab3->ByteLength()));
   CHECK(ab3->IsExternal());
 
@@ -2718,6 +2729,7 @@ static Handle<TypedArray> CreateAndCheck(Handle<v8::ArrayBuffer> ab,
                                          int byteOffset,
                                          int length) {
   v8::Handle<TypedArray> ta = TypedArray::New(ab, byteOffset, length);
+  CheckInternalFieldsAreZero<v8::ArrayBufferView>(ta);
   CHECK_EQ(byteOffset, static_cast<int>(ta->ByteOffset()));
   CHECK_EQ(length, static_cast<int>(ta->Length()));
   CHECK_EQ(length * kElementSize, static_cast<int>(ta->ByteLength()));
@@ -2755,6 +2767,7 @@ THREADED_TEST(ArrayBuffer_NeuteringApi) {
     CreateAndCheck<v8::Float64Array, 8>(buffer, 8, 127);
 
   v8::Handle<v8::DataView> dv = v8::DataView::New(buffer, 1, 1023);
+  CheckInternalFieldsAreZero<v8::ArrayBufferView>(dv);
   CHECK_EQ(1, static_cast<int>(dv->ByteOffset()));
   CHECK_EQ(1023, static_cast<int>(dv->ByteLength()));
 
@@ -15783,6 +15796,7 @@ void TypedArrayTestHelper(v8::ExternalArrayType array_type,
       backing_store.start(), (kElementCount+2)*sizeof(ElementType));
   Local<TypedArray> ta =
       TypedArray::New(ab, 2*sizeof(ElementType), kElementCount);
+  CheckInternalFieldsAreZero<v8::ArrayBufferView>(ta);
   CHECK_EQ(kElementCount, static_cast<int>(ta->Length()));
   CHECK_EQ(2*sizeof(ElementType), static_cast<int>(ta->ByteOffset()));
   CHECK_EQ(kElementCount*sizeof(ElementType),
@@ -15868,6 +15882,7 @@ THREADED_TEST(DataView) {
       backing_store.start(), 2 + kSize);
   Local<v8::DataView> dv =
       v8::DataView::New(ab, 2, kSize);
+  CheckInternalFieldsAreZero<v8::ArrayBufferView>(dv);
   CHECK_EQ(2, static_cast<int>(dv->ByteOffset()));
   CHECK_EQ(kSize, static_cast<int>(dv->ByteLength()));
   CHECK_EQ(ab, dv->Buffer());
@@ -15887,6 +15902,7 @@ THREADED_TEST(DataView) {
         "new " #View "(ab)");                                                 \
     CHECK(result->IsArrayBufferView());                                       \
     CHECK(result->Is##View());                                                \
+    CheckInternalFieldsAreZero<v8::ArrayBufferView>(result.As<v8::View>());   \
   }
 
 IS_ARRAY_BUFFER_VIEW_TEST(Uint8Array)