async_wrap,src: wrap promises directly

configure

@@ -954,6 +954,7 @@ def configure_v8(o):
   o['variables']['v8_no_strict_aliasing'] = 1  # Work around compiler bugs.
   o['variables']['v8_optimized_debug'] = 0  # Compile with -O0 in debug builds.
   o['variables']['v8_random_seed'] = 0  # Use a random seed for hash tables.
+  o['variables']['v8_promise_internal_field_count'] = 1 # Add internal field to promises for async hooks.
   o['variables']['v8_use_snapshot'] = 'false' if options.without_snapshot else 'true'
   o['variables']['node_use_v8_platform'] = b(not options.without_v8_platform)
   o['variables']['node_use_bundled_v8'] = b(not options.without_bundled_v8)

deps/v8/BUILD.gn

@@ -38,6 +38,9 @@ declare_args() {
   # Sets -dENABLE_DISASSEMBLER.
   v8_enable_disassembler = ""
 
+  # Sets the number of internal fields on promise objects.
+  v8_promise_internal_field_count = 0
+
   # Sets -dENABLE_GDB_JIT_INTERFACE.
   v8_enable_gdbjit = ""
 
@@ -197,6 +200,10 @@ config("features") {
   if (v8_enable_disassembler) {
     defines += [ "ENABLE_DISASSEMBLER" ]
   }
+  if (v8_promise_internal_field_count != 0) {
+    defines +=
+        [ "V8_PROMISE_INTERNAL_FIELD_COUNT=${v8_promise_internal_field_count}" ]
+  }
   if (v8_enable_gdbjit) {
     defines += [ "ENABLE_GDB_JIT_INTERFACE" ]
   }

deps/v8/gypfiles/features.gypi

@@ -31,6 +31,8 @@
   'variables': {
     'v8_enable_disassembler%': 0,
 
+    'v8_promise_internal_field_count%': 0,
+
     'v8_enable_gdbjit%': 0,
 
     'v8_enable_verify_csa%': 0,
@@ -77,6 +79,9 @@
       ['v8_enable_disassembler==1', {
         'defines': ['ENABLE_DISASSEMBLER',],
       }],
+      ['v8_promise_internal_field_count!=0', {
+        'defines': ['V8_PROMISE_INTERNAL_FIELD_COUNT','v8_promise_internal_field_count'],
+      }],
       ['v8_enable_gdbjit==1', {
         'defines': ['ENABLE_GDB_JIT_INTERFACE',],
       }],

deps/v8/include/v8-version.h

@@ -11,7 +11,7 @@
 #define V8_MAJOR_VERSION 5
 #define V8_MINOR_VERSION 8
 #define V8_BUILD_NUMBER 283
-#define V8_PATCH_LEVEL 40
+#define V8_PATCH_LEVEL 41
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)

deps/v8/include/v8.h

@@ -3741,6 +3741,10 @@ class V8_EXPORT Function : public Object {
   static void CheckCast(Value* obj);
 };
 
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
 
 /**
  * An instance of the built-in Promise constructor (ES6 draft).
@@ -3822,6 +3826,8 @@ class V8_EXPORT Promise : public Object {
 
   V8_INLINE static Promise* Cast(Value* obj);
 
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
  private:
   Promise();
   static void CheckCast(Value* obj);

deps/v8/src/bootstrapper.cc

@@ -1945,9 +1945,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), TENURED);
-    Handle<JSFunction> promise_fun =
-        InstallFunction(global, "Promise", JS_PROMISE_TYPE, JSPromise::kSize,
-                        prototype, Builtins::kPromiseConstructor);
+    Handle<JSFunction> promise_fun = InstallFunction(
+        global, "Promise", JS_PROMISE_TYPE, JSPromise::kSizeWithEmbedderFields,
+        prototype, Builtins::kPromiseConstructor);
     InstallWithIntrinsicDefaultProto(isolate, promise_fun,
                                      Context::PROMISE_FUNCTION_INDEX);
 

deps/v8/src/builtins/builtins-promise.cc

@@ -31,6 +31,10 @@ void PromiseBuiltinsAssembler::PromiseInit(Node* promise) {
   StoreObjectField(promise, JSPromise::kStatusOffset,
                    SmiConstant(v8::Promise::kPending));
   StoreObjectField(promise, JSPromise::kFlagsOffset, SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(promise, offset, SmiConstant(Smi::kZero));
+  }
 }
 
 Node* PromiseBuiltinsAssembler::AllocateAndInitJSPromise(Node* context) {
@@ -62,6 +66,10 @@ Node* PromiseBuiltinsAssembler::AllocateAndSetJSPromise(Node* context,
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kResultOffset, result);
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kFlagsOffset,
                                  SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(instance, offset, SmiConstant(Smi::kZero));
+  }
 
   Label out(this);
   GotoIfNot(IsPromiseHookEnabledOrDebugIsActive(), &out);

deps/v8/src/objects.h

@@ -8443,6 +8443,8 @@ class JSPromise : public JSObject {
       kFulfillReactionsOffset + kPointerSize;
   static const int kFlagsOffset = kRejectReactionsOffset + kPointerSize;
   static const int kSize = kFlagsOffset + kPointerSize;
+  static const int kSizeWithEmbedderFields =
+      kSize + v8::Promise::kEmbedderFieldCount * kPointerSize;
 
   // Flags layout.
   static const int kHasHandlerBit = 0;

src/async-wrap.cc

@@ -281,32 +281,13 @@ static void PromiseHook(PromiseHookType type, Local<Promise> promise,
   Local<Context> context = promise->CreationContext();
   Environment* env = Environment::GetCurrent(context);
   if (type == PromiseHookType::kInit) {
-    // Unfortunately, promises don't have internal fields. Need a surrogate that
-    // async wrap can wrap.
-    Local<Object> obj =
-      env->async_hooks_promise_object()->NewInstance(context).ToLocalChecked();
-    PromiseWrap* wrap = new PromiseWrap(env, obj);
-    v8::PropertyAttribute hidden =
-      static_cast<v8::PropertyAttribute>(v8::ReadOnly
-                                         | v8::DontDelete
-                                         | v8::DontEnum);
-    promise->DefineOwnProperty(context,
-              env->promise_wrap(),
-              v8::External::New(env->isolate(), wrap),
-              hidden).FromJust();
-    // The async tag will be destroyed at the same time as the promise as the
-    // only reference to it is held by the promise. This allows the promise
-    // wrap instance to be notified when the promise is destroyed.
-    promise->DefineOwnProperty(context,
-              env->promise_async_tag(),
-              obj, hidden).FromJust();
+    PromiseWrap* wrap = new PromiseWrap(env, promise);
+    promise->SetAlignedPointerInInternalField(0, wrap);
   } else if (type == PromiseHookType::kResolve) {
     // TODO(matthewloring): need to expose this through the async hooks api.
   }
-  Local<v8::Value> external_wrap =
-      promise->Get(context, env->promise_wrap()).ToLocalChecked();
   PromiseWrap* wrap =
-    static_cast<PromiseWrap*>(external_wrap.As<v8::External>()->Value());
+    static_cast<PromiseWrap*>(promise->GetAlignedPointerFromInternalField(0));
   CHECK_NE(wrap, nullptr);
   if (type == PromiseHookType::kBefore) {
     PreCallbackExecution(wrap, false);
@@ -402,11 +383,6 @@ void AsyncWrap::Initialize(Local<Object> target,
   env->SetMethod(target, "clearIdStack", ClearIdStack);
   env->SetMethod(target, "addIdToDestroyList", QueueDestroyId);
 
-  Local<v8::ObjectTemplate> promise_object_template =
-    v8::ObjectTemplate::New(env->isolate());
-  promise_object_template->SetInternalFieldCount(1);
-  env->set_async_hooks_promise_object(promise_object_template);
-
   v8::PropertyAttribute ReadOnlyDontDelete =
       static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete);
 

src/env.h

@@ -195,8 +195,6 @@ namespace node {
   V(preference_string, "preference")                                          \
   V(priority_string, "priority")                                              \
   V(produce_cached_data_string, "produceCachedData")                          \
-  V(promise_wrap, "_promise_async_wrap")                                      \
-  V(promise_async_tag, "_promise_async_wrap_tag")                             \
   V(raw_string, "raw")                                                        \
   V(read_host_object_string, "_readHostObject")                               \
   V(readable_string, "readable")                                              \
@@ -258,7 +256,6 @@ namespace node {
   V(async_hooks_init_function, v8::Function)                                  \
   V(async_hooks_before_function, v8::Function)                                \
   V(async_hooks_after_function, v8::Function)                                 \
-  V(async_hooks_promise_object, v8::ObjectTemplate)                           \
   V(binding_cache_object, v8::Object)                                         \
   V(buffer_constructor_function, v8::Function)                                \
   V(buffer_prototype_object, v8::Object)                                      \