Reland "Remove the weak list of views from array buffers"

src/runtime/runtime-typedarray.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 
@@ skipping 45 matching lines @@
     array_buffer->set_weak_next(isolate->heap()->array_buffers_list());
     isolate->heap()->set_array_buffers_list(*array_buffer);
     if (isolate->heap()->last_array_buffer_in_list()->IsUndefined()) {
       isolate->heap()->set_last_array_buffer_in_list(*array_buffer);
     }
   } else {
     JSArrayBuffer::cast(isolate->heap()->last_array_buffer_in_list())
         ->set_weak_next(*array_buffer);
     isolate->heap()->set_last_array_buffer_in_list(*array_buffer);
   }
-  array_buffer->set_weak_first_view(isolate->heap()->undefined_value());
 }
 
 
 bool Runtime::SetupArrayBufferAllocatingData(Isolate* isolate,
                                              Handle<JSArrayBuffer> array_buffer,
                                              size_t allocated_length,
                                              bool initialize) {
   void* data;
   CHECK(V8::ArrayBufferAllocator() != NULL);
   // Prevent creating array buffers when serializing.
@@ skipping 13 matching lines @@
   SetupArrayBuffer(isolate, array_buffer, false, data, allocated_length);
 
   reinterpret_cast<v8::Isolate*>(isolate)
       ->AdjustAmountOfExternalAllocatedMemory(allocated_length);
 
   return true;
 }
 
 
 void Runtime::NeuterArrayBuffer(Handle<JSArrayBuffer> array_buffer) {
-  Isolate* isolate = array_buffer->GetIsolate();
-  // Firstly, iterate over the views which are referenced directly by the array
-  // buffer.
-  for (Handle<Object> view_obj(array_buffer->weak_first_view(), isolate);
-       !view_obj->IsUndefined();) {
-    Handle<JSArrayBufferView> view(JSArrayBufferView::cast(*view_obj));
-    if (view->IsJSTypedArray()) {
-      JSTypedArray::cast(*view)->Neuter();
-    } else if (view->IsJSDataView()) {
-      JSDataView::cast(*view)->Neuter();
-    } else {
-      UNREACHABLE();
-    }
-    view_obj = handle(view->weak_next(), isolate);
-  }
-
-  // Secondly, iterate over the global list of new space views to find views
-  // that belong to the neutered array buffer.
-  Heap* heap = isolate->heap();
-  for (Handle<Object> view_obj(heap->new_array_buffer_views_list(), isolate);
-       !view_obj->IsUndefined();) {
-    Handle<JSArrayBufferView> view(JSArrayBufferView::cast(*view_obj));
-    if (view->buffer() == *array_buffer) {
-      if (view->IsJSTypedArray()) {
-        JSTypedArray::cast(*view)->Neuter();
-      } else if (view->IsJSDataView()) {
-        JSDataView::cast(*view)->Neuter();
-      } else {
-        UNREACHABLE();
-      }
-    }
-    view_obj = handle(view->weak_next(), isolate);
-  }
   array_buffer->Neuter();
 }
 
 
 RUNTIME_FUNCTION(Runtime_ArrayBufferInitialize) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, holder, 0);
   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byteLength, 1);
   if (!holder->byte_length()->IsUndefined()) {
@@ skipping 145 matching lines @@
   DCHECK(holder->GetInternalFieldCount() ==
          v8::ArrayBufferView::kInternalFieldCount);
   for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
     holder->SetInternalField(i, Smi::FromInt(0));
   }
   Handle<Object> length_obj = isolate->factory()->NewNumberFromSize(length);
   holder->set_length(*length_obj);
   holder->set_byte_offset(*byte_offset_object);
   holder->set_byte_length(*byte_length_object);
 
-  Heap* heap = isolate->heap();
   if (!maybe_buffer->IsNull()) {
     Handle<JSArrayBuffer> buffer = Handle<JSArrayBuffer>::cast(maybe_buffer);
     holder->set_buffer(*buffer);
 
-    if (heap->InNewSpace(*holder)) {
-      holder->set_weak_next(heap->new_array_buffer_views_list());
-      heap->set_new_array_buffer_views_list(*holder);
-    } else {
-      holder->set_weak_next(buffer->weak_first_view());
-      buffer->set_weak_first_view(*holder);
-    }
-
     Handle<ExternalArray> elements = isolate->factory()->NewExternalArray(
         static_cast<int>(length), array_type,
         static_cast<uint8_t*>(buffer->backing_store()) + byte_offset);
     Handle<Map> map =
         JSObject::GetElementsTransitionMap(holder, external_elements_kind);
     JSObject::SetMapAndElements(holder, map, elements);
     DCHECK(IsExternalArrayElementsKind(holder->map()->elements_kind()));
   } else {
     holder->set_buffer(Smi::FromInt(0));
-    holder->set_weak_next(isolate->heap()->undefined_value());
     Handle<FixedTypedArrayBase> elements =
         isolate->factory()->NewFixedTypedArray(static_cast<int>(length),
                                                array_type);
     holder->set_elements(*elements);
   }
   return isolate->heap()->undefined_value();
 }
 
 
 // Initializes a typed array from an array-like object.
@@ skipping 67 matching lines @@
                                HandleVector<Object>(NULL, 0)));
   }
 
   holder->set_buffer(*buffer);
   holder->set_byte_offset(Smi::FromInt(0));
   Handle<Object> byte_length_obj(
       isolate->factory()->NewNumberFromSize(byte_length));
   holder->set_byte_length(*byte_length_obj);
   holder->set_length(*length_obj);
 
-  Heap* heap = isolate->heap();
-  if (heap->InNewSpace(*holder)) {
-    holder->set_weak_next(heap->new_array_buffer_views_list());
-    heap->set_new_array_buffer_views_list(*holder);
-  } else {
-    holder->set_weak_next(buffer->weak_first_view());
-    buffer->set_weak_first_view(*holder);
-  }
-
   Handle<ExternalArray> elements = isolate->factory()->NewExternalArray(
       static_cast<int>(length), array_type,
       static_cast<uint8_t*>(buffer->backing_store()));
   Handle<Map> map =
       JSObject::GetElementsTransitionMap(holder, external_elements_kind);
   JSObject::SetMapAndElements(holder, map, elements);
 
   if (source->IsJSTypedArray()) {
     Handle<JSTypedArray> typed_array(JSTypedArray::cast(*source));
 
@@ skipping 152 matching lines @@
   // Entire range [offset, offset + length] must be in bounds.
   RUNTIME_ASSERT(offset <= buffer_length);
   RUNTIME_ASSERT(offset + length <= buffer_length);
   // No overflow.
   RUNTIME_ASSERT(offset + length >= offset);
 
   holder->set_buffer(*buffer);
   holder->set_byte_offset(*byte_offset);
   holder->set_byte_length(*byte_length);
 
-  Heap* heap = isolate->heap();
-  if (heap->InNewSpace(*holder)) {
-    holder->set_weak_next(heap->new_array_buffer_views_list());
-    heap->set_new_array_buffer_views_list(*holder);
-  } else {
-    holder->set_weak_next(buffer->weak_first_view());
-    buffer->set_weak_first_view(*holder);
-  }
-
   return isolate->heap()->undefined_value();
 }
 
 
 inline static bool NeedToFlipBytes(bool is_little_endian) {
 #ifdef V8_TARGET_LITTLE_ENDIAN
   return !is_little_endian;
 #else
   return is_little_endian;
 #endif
@@ skipping 203 matching lines @@
 DATA_VIEW_SETTER(Uint16, uint16_t)
 DATA_VIEW_SETTER(Int16, int16_t)
 DATA_VIEW_SETTER(Uint32, uint32_t)
 DATA_VIEW_SETTER(Int32, int32_t)
 DATA_VIEW_SETTER(Float32, float)
 DATA_VIEW_SETTER(Float64, double)
 
 #undef DATA_VIEW_SETTER
 }
 }  // namespace v8::internal