[Atomics] code stubs for atomic operations

src/bootstrapper.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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 2400 matching lines @@
                         Builtins::kReflectSet, 3, false);
   SimpleInstallFunction(reflect, factory->setPrototypeOf_string(),
                         Builtins::kReflectSetPrototypeOf, 2, true);
 }
 
 
 void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
   if (!FLAG_harmony_sharedarraybuffer) return;
 
   Handle<JSGlobalObject> global(native_context()->global_object());
+  Isolate* isolate = global->GetIsolate();
+  Factory* factory = isolate->factory();
+
   Handle<JSFunction> shared_array_buffer_fun =
       InstallArrayBuffer(global, "SharedArrayBuffer");
   native_context()->set_shared_array_buffer_fun(*shared_array_buffer_fun);
+
+  Handle<String> name = factory->InternalizeUtf8String("Atomics");
+  Handle<JSFunction> cons = factory->NewFunction(name);
+  JSFunction::SetInstancePrototype(
+      cons,
+      Handle<Object>(native_context()->initial_object_prototype(), isolate));
+  Handle<JSObject> atomics_object = factory->NewJSObject(cons, TENURED);
+  DCHECK(atomics_object->IsJSObject());
+  JSObject::AddProperty(global, name, atomics_object, DONT_ENUM);
+
+  SimpleInstallFunction(atomics_object, factory->InternalizeUtf8String("load"),
+                        Builtins::kAtomicsLoadCheck, 2, false);

[Jarin, 2016/02/03 09:04:07]

Here, you should pass "true" as the last argument. This would make sure that the
builtin is always called with two arguments (if the caller provides different
number of arguments, extra arguments will be ignored and missing arguments will
be undefined).

[binji, 2016/02/03 22:09:02]

Cool, that seems to work. Thanks! I saw "adapt", but I didn't know what that
meant. :)

 }
 
 
 void Genesis::InitializeGlobal_harmony_simd() {
   if (!FLAG_harmony_simd) return;
 
   Handle<JSGlobalObject> global(
       JSGlobalObject::cast(native_context()->global_object()));
   Isolate* isolate = global->GetIsolate();
   Factory* factory = isolate->factory();
@@ skipping 1197 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8