Sharing of SharedArrayBuffer via PostMessage transfer

Source/bindings/templates/interface.cpp

 {% extends 'interface_base.cpp' %}
 
 
 {##############################################################################}
 {% block indexed_property_getter %}
 {% if indexed_property_getter and not indexed_property_getter.is_custom %}
 {% set getter = indexed_property_getter %}
 static void indexedPropertyGetter(uint32_t index, const v8::PropertyCallbackInfo<v8::Value>& info)
 {
     {{cpp_class}}* impl = {{v8_class}}::toImpl(info.Holder());
@@ skipping 728 matching lines @@
     // Transfer the ownership of the allocated memory to an ArrayBuffer without
     // copying.
     v8::ArrayBuffer::Contents v8Contents = v8buffer->Externalize();
     WTF::ArrayBufferContents contents(v8Contents.Data(), v8Contents.ByteLength(), WTF::ArrayBufferContents::NotShared);
     RefPtr<{{cpp_class}}> buffer = {{cpp_class}}::create(contents);
     buffer->associateWithWrapper(v8::Isolate::GetCurrent(), buffer->wrapperTypeInfo(), object);
 
     return buffer.get();
 }
 
+{% elif interface_name == 'SharedArrayBuffer' %}
+{{cpp_class}}* V8SharedArrayBuffer::toImpl(v8::Local<v8::Object> object)
+{
+    ASSERT(object->IsSharedArrayBuffer());
+    v8::Local<v8::SharedArrayBuffer> v8buffer = object.As<v8::SharedArrayBuffer>();
+    if (v8buffer->IsExternal()) {
+        const WrapperTypeInfo* wrapperTypeInfo = toWrapperTypeInfo(object);
+        RELEASE_ASSERT(wrapperTypeInfo);
+        RELEASE_ASSERT(wrapperTypeInfo->ginEmbedder == gin::kEmbedderBlink);
+        return toScriptWrappable(object)->toImpl<{{cpp_class}}>();
+    }
+
+    // Transfer the ownership of the allocated memory to a SharedArrayBuffer
+    // without copying.
+    v8::SharedArrayBuffer::Contents v8Contents = v8buffer->Externalize();
+    WTF::ArrayBufferContents contents(v8Contents.Data(), v8Contents.ByteLength(), WTF::ArrayBufferContents::Shared);
+    RefPtr<{{cpp_class}}> buffer = {{cpp_class}}::create(contents);
+    buffer->associateWithWrapper(v8::Isolate::GetCurrent(), buffer->wrapperTypeInfo(), object);
+
+    return buffer.get();
+}
+
 {% elif interface_name == 'ArrayBufferView' %}
 {{cpp_class}}* V8ArrayBufferView::toImpl(v8::Local<v8::Object> object)
 {
     ASSERT(object->IsArrayBufferView());
     ScriptWrappable* scriptWrappable = toScriptWrappable(object);
     if (scriptWrappable)
         return scriptWrappable->toImpl<{{cpp_class}}>();
 
     if (object->IsInt8Array())
         return V8Int8Array::toImpl(object);
@@ skipping 22 matching lines @@
 
 {% elif is_array_buffer_or_view %}
 {{cpp_class}}* {{v8_class}}::toImpl(v8::Local<v8::Object> object)
 {
     ASSERT(object->Is{{interface_name}}());
     ScriptWrappable* scriptWrappable = toScriptWrappable(object);
     if (scriptWrappable)
         return scriptWrappable->toImpl<{{cpp_class}}>();
 
     v8::Local<v8::{{interface_name}}> v8View = object.As<v8::{{interface_name}}>();
-    RefPtr<{{cpp_class}}> typedArray = {{cpp_class}}::create(V8ArrayBuffer::toImpl(v8View->Buffer()), v8View->ByteOffset(), v8View->{% if interface_name == 'DataView' %}Byte{% endif %}Length());
+    v8::Local<v8::Object> arrayBuffer = v8View->Buffer();
+    RefPtr<{{cpp_class}}> typedArray;
+{% if interface_name == 'DataView' %}
+    if (arrayBuffer->IsArrayBuffer()) {
+        typedArray = {{cpp_class}}::create(V8ArrayBuffer::toImpl(arrayBuffer), v8View->ByteOffset(), v8View->ByteLength());
+    } else if (arrayBuffer->IsSharedArrayBuffer()) {
+        typedArray = {{cpp_class}}::create(V8SharedArrayBuffer::toImpl(arrayBuffer), v8View->ByteOffset(), v8View->ByteLength());
+    } else {
+        ASSERT_NOT_REACHED();
+    }
+{% else %}
+    if (arrayBuffer->IsArrayBuffer()) {
+        typedArray = {{cpp_class}}::create(V8ArrayBuffer::toImpl(arrayBuffer), v8View->ByteOffset(), v8View->Length());
+    } else if (arrayBuffer->IsSharedArrayBuffer()) {
+        typedArray = {{cpp_class}}::create(V8SharedArrayBuffer::toImpl(arrayBuffer), v8View->ByteOffset(), v8View->Length());
+    } else {
+        ASSERT_NOT_REACHED();
+    }
+{% endif %}
     typedArray->associateWithWrapper(v8::Isolate::GetCurrent(), typedArray->wrapperTypeInfo(), object);
 
     return typedArray->toImpl<{{cpp_class}}>();
 }
 
 {% endif %}
 {% endblock %}
 
 
 {##############################################################################}
@@ skipping 155 matching lines @@
 }
 
 {% for method in methods if method.overloads and method.overloads.has_partial_overloads %}
 void {{v8_class}}::register{{method.name | blink_capitalize}}MethodForPartialInterface(void (*method)(const v8::FunctionCallbackInfo<v8::Value>&))
 {
     {{cpp_class}}V8Internal::{{method.name}}MethodForPartialInterface = method;
 }
 {% endfor %}
 {% endif %}
 {% endblock %}