Implement SharedArrayBuffer

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/messages.h"
 #include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 
 
 namespace v8 {
 namespace internal {
 
 void Runtime::SetupArrayBuffer(Isolate* isolate,
                                Handle<JSArrayBuffer> array_buffer,
                                bool is_external, void* data,
-                               size_t allocated_length) {
+                               size_t allocated_length, SharedFlag shared) {
   DCHECK(array_buffer->GetInternalFieldCount() ==
          v8::ArrayBuffer::kInternalFieldCount);
   for (int i = 0; i < v8::ArrayBuffer::kInternalFieldCount; i++) {
     array_buffer->SetInternalField(i, Smi::FromInt(0));
   }
   array_buffer->set_backing_store(data);
   array_buffer->set_bit_field(0);
   array_buffer->set_is_external(is_external);
-  array_buffer->set_is_neuterable(true);
+  array_buffer->set_is_neuterable(shared == SharedFlag::kNotShared);
+  array_buffer->set_is_shared(shared == SharedFlag::kShared);
 
   Handle<Object> byte_length =
       isolate->factory()->NewNumberFromSize(allocated_length);
   CHECK(byte_length->IsSmi() || byte_length->IsHeapNumber());
   array_buffer->set_byte_length(*byte_length);
 
   if (data && !is_external) {
     isolate->heap()->RegisterNewArrayBuffer(data, allocated_length);
   }
 }
 
 
 bool Runtime::SetupArrayBufferAllocatingData(Isolate* isolate,
                                              Handle<JSArrayBuffer> array_buffer,
                                              size_t allocated_length,
-                                             bool initialize) {
+                                             bool initialize,
+                                             SharedFlag shared) {
   void* data;
   CHECK(isolate->array_buffer_allocator() != NULL);
   // Prevent creating array buffers when serializing.
   DCHECK(!isolate->serializer_enabled());
   if (allocated_length != 0) {
     if (initialize) {
       data = isolate->array_buffer_allocator()->Allocate(allocated_length);
     } else {
       data = isolate->array_buffer_allocator()->AllocateUninitialized(
           allocated_length);
     }
     if (data == NULL) return false;
   } else {
     data = NULL;
   }
 
-  SetupArrayBuffer(isolate, array_buffer, false, data, allocated_length);
+  SetupArrayBuffer(isolate, array_buffer, false, data, allocated_length,
+                   shared);
   return true;
 }
 
 
 void Runtime::NeuterArrayBuffer(Handle<JSArrayBuffer> array_buffer) {
   array_buffer->Neuter();
 }
 
 
 RUNTIME_FUNCTION(Runtime_ArrayBufferInitialize) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
+  DCHECK(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, holder, 0);
   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byteLength, 1);
+  CONVERT_BOOLEAN_ARG_CHECKED(is_shared, 2);
   if (!holder->byte_length()->IsUndefined()) {
     // ArrayBuffer is already initialized; probably a fuzz test.
     return *holder;
   }
   size_t allocated_length = 0;
   if (!TryNumberToSize(isolate, *byteLength, &allocated_length)) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
   }
-  if (!Runtime::SetupArrayBufferAllocatingData(isolate, holder,
-                                               allocated_length)) {
+  if (!Runtime::SetupArrayBufferAllocatingData(
+          isolate, holder, allocated_length, true,
+          is_shared ? SharedFlag::kShared : SharedFlag::kNotShared)) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
   }
   return *holder;
 }
 
 
 RUNTIME_FUNCTION(Runtime_ArrayBufferGetByteLength) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
@@ skipping 34 matching lines @@
 
 
 RUNTIME_FUNCTION(Runtime_ArrayBufferNeuter) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, array_buffer, 0);
   if (array_buffer->backing_store() == NULL) {
     CHECK(Smi::FromInt(0) == array_buffer->byte_length());
     return isolate->heap()->undefined_value();
   }
+  // Shared array buffers should never be neutered.
+  DCHECK(!array_buffer->is_shared());
   DCHECK(!array_buffer->is_external());
   void* backing_store = array_buffer->backing_store();
   size_t byte_length = NumberToSize(isolate, array_buffer->byte_length());
   array_buffer->set_is_external(true);
   Runtime::NeuterArrayBuffer(array_buffer);
   isolate->heap()->UnregisterArrayBuffer(backing_store);
   isolate->array_buffer_allocator()->Free(backing_store, byte_length);
   return isolate->heap()->undefined_value();
 }
 
@@ skipping 82 matching lines @@
 
     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 {
     Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
-    Runtime::SetupArrayBuffer(isolate, buffer, true, NULL, byte_length);
+    Runtime::SetupArrayBuffer(isolate, buffer, true, NULL, byte_length,
+                              SharedFlag::kNotShared);
     holder->set_buffer(*buffer);
     Handle<FixedTypedArrayBase> elements =
         isolate->factory()->NewFixedTypedArray(static_cast<int>(length),
                                                array_type);
     holder->set_elements(*elements);
   }
   return isolate->heap()->undefined_value();
 }
 
 
@@ skipping 459 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 internal
 }  // namespace v8