Simplify, speed-up correct-context ObjectObserve calls

The original patch which ensured that Object.observe did allocations in the correct context regressed performance about 12%. This patch gets back most of that (about 11%) by simply returning the correct function which is then directly callable from JS, rather than by making the call from the runtime function. A side-effect is that their implementation is shorter.

LOG=Y
BUG=NONE
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/307543008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21575 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/object-observe.js

@@ -368,7 +368,8 @@ function ObjectObserve(object, callback, acceptList) {
   if (ObjectIsFrozen(callback))
     throw MakeTypeError("observe_callback_frozen");
 
-  return %ObjectObserveInObjectContext(object, callback, acceptList);
+  var objectObserveFn = %GetObjectContextObjectObserve(object);
+  return objectObserveFn(object, callback, acceptList);
 }
 
 function NativeObjectObserve(object, callback, acceptList) {
@@ -543,8 +544,8 @@ function ObjectNotifierPerformChange(changeType, changeFn) {
   if (!IS_SPEC_FUNCTION(changeFn))
     throw MakeTypeError("observe_perform_non_function");
 
-  return %ObjectNotifierPerformChangeInObjectContext(
+  var performChangeFn = %GetObjectContextNotifierPerformChange(objectInfo);
-      objectInfo, changeType, changeFn);
+  performChangeFn(objectInfo, changeType, changeFn);
 }
 
 function NativeObjectNotifierPerformChange(objectInfo, changeType, changeFn) {
@@ -571,7 +572,8 @@ function ObjectGetNotifier(object) {
 
   if (!%ObjectWasCreatedInCurrentOrigin(object)) return null;
 
-  return %ObjectGetNotifierInObjectContext(object);
+  var getNotifierFn = %GetObjectContextObjectGetNotifier(object);
+  return getNotifierFn(object);
 }
 
 function NativeObjectGetNotifier(object) {

src/runtime.cc

@@ -14889,64 +14889,33 @@ RUNTIME_FUNCTION(Runtime_ObjectWasCreatedInCurrentOrigin) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_ObjectObserveInObjectContext) {
+RUNTIME_FUNCTION(Runtime_GetObjectContextObjectObserve) {
-  HandleScope scope(isolate);
-  ASSERT(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, callback, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, accept, 2);
-
-  Handle<Context> context(object->GetCreationContext(), isolate);
-  Handle<JSFunction> function(context->native_object_observe(), isolate);
-  Handle<Object> call_args[] = { object, callback, accept };
-  Handle<Object> result;
-
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      Execution::Call(isolate, function,
-          handle(context->object_function(), isolate),
-          ARRAY_SIZE(call_args), call_args, true));
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_ObjectGetNotifierInObjectContext) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
 
   Handle<Context> context(object->GetCreationContext(), isolate);
-  Handle<JSFunction> function(context->native_object_get_notifier(), isolate);
+  return context->native_object_observe();
-  Handle<Object> call_args[] = { object };
-  Handle<Object> result;
-
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      Execution::Call(isolate, function,
-          handle(context->object_function(), isolate),
-          ARRAY_SIZE(call_args), call_args, true));
-  return *result;
 }
 
 
-RUNTIME_FUNCTION(Runtime_ObjectNotifierPerformChangeInObjectContext) {
+RUNTIME_FUNCTION(Runtime_GetObjectContextObjectGetNotifier) {
   HandleScope scope(isolate);
-  ASSERT(args.length() == 3);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+
+  Handle<Context> context(object->GetCreationContext(), isolate);
+  return context->native_object_get_notifier();
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetObjectContextNotifierPerformChange) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object_info, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, change_type, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, change_fn, 2);
 
   Handle<Context> context(object_info->GetCreationContext(), isolate);
-  Handle<JSFunction> function(context->native_object_notifier_perform_change(),
+  return context->native_object_notifier_perform_change();
-      isolate);
-  Handle<Object> call_args[] = { object_info, change_type, change_fn };
-  Handle<Object> result;
-
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      Execution::Call(isolate, function, isolate->factory()->undefined_value(),
-                      ARRAY_SIZE(call_args), call_args, true));
-  return *result;
 }
 
 

src/runtime.h

@@ -306,9 +306,9 @@ namespace internal {
   F(ObservationWeakMapCreate, 0, 1) \
   F(ObserverObjectAndRecordHaveSameOrigin, 3, 1) \
   F(ObjectWasCreatedInCurrentOrigin, 1, 1) \
-  F(ObjectObserveInObjectContext, 3, 1) \
+  F(GetObjectContextObjectObserve, 1, 1) \
-  F(ObjectGetNotifierInObjectContext, 1, 1) \
+  F(GetObjectContextObjectGetNotifier, 1, 1) \
-  F(ObjectNotifierPerformChangeInObjectContext, 3, 1) \
+  F(GetObjectContextNotifierPerformChange, 1, 1) \
   \
   /* Harmony typed arrays */ \
   F(ArrayBufferInitialize, 2, 1)\

test/mjsunit/runtime-gen/getobjectcontextnotifierperformchange.js

@@ -2,6 +2,4 @@
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
 var _object_info = new Object();
-var _change_type = "foo";
+%GetObjectContextNotifierPerformChange(_object_info);
-var _change_fn = function() {};
-%ObjectNotifierPerformChangeInObjectContext(_object_info, _change_type, _change_fn);

test/mjsunit/runtime-gen/getobjectcontextobjectgetnotifier.js

@@ -2,6 +2,4 @@
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
 var _object = new Object();
-var _callback = function() {};
+%GetObjectContextObjectGetNotifier(_object);
-var _accept = new Object();
-%ObjectObserveInObjectContext(_object, _callback, _accept);

test/mjsunit/runtime-gen/getobjectcontextobjectobserve.js

@@ -2,4 +2,4 @@
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
 var _object = new Object();
-%ObjectGetNotifierInObjectContext(_object);
+%GetObjectContextObjectObserve(_object);