[promises] Move PromiseReactionJob to c++

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 20ff7ff899e317ae3f62f84099117d0165e16677..4c9fda66c11150d1cdf280c2a71076da316d9437 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -8,7 +8,6 @@
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
-
 #include "src/ast/context-slot-cache.h"
 #include "src/base/hashmap.h"
 #include "src/base/platform/platform.h"
@@ -24,6 +23,7 @@
 #include "src/crankshaft/hydrogen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
+#include "src/elements.h"
 #include "src/external-reference-table.h"
 #include "src/frames-inl.h"
 #include "src/ic/access-compiler-data.h"
@@ -3008,6 +3008,55 @@ void Isolate::ReportPromiseReject(Handle<JSObject> promise,
       v8::Utils::StackTraceToLocal(stack_trace)));
 }
 
+void Isolate::PromiseReactionJob(Handle<PromiseHandleInfo> promise_handle_info,
+                                 MaybeHandle<Object>* result,
+                                 MaybeHandle<Object>* maybe_exception) {
+  if (debug()->is_active()) {
+    Handle<Object> before_debug_event(promise_handle_info->before_debug_event(),
+                                      this);
+    if (before_debug_event->IsJSObject()) {
+      debug()->OnAsyncTaskEvent(Handle<JSObject>::cast(before_debug_event));
+    }
+  }
+
+  Handle<Object> value(promise_handle_info->value(), this);
+  Handle<Object> tasks(promise_handle_info->tasks(), this);
+
+  if (tasks->IsJSArray()) {
+    Handle<JSArray> array = Handle<JSArray>::cast(tasks);
+    DCHECK(array->length()->IsSmi());
+    Handle<FixedArrayBase> elements(array->elements(), this);
+    // Safer way to get length? Check backing store?
+    int length = elements->length();
+    ElementsAccessor* accessor = array->GetElementsAccessor();
+    for (int i = 0; i < length; i += 2) {
+      // Do I need the check?
+      if (accessor->HasElement(array, i, elements) &&
+          accessor->HasElement(array, i + 1, elements)) {
+        Handle<Object> argv[] = {value, accessor->Get(array, i),
+                                 accessor->Get(array, i + 1)};
+        *result = Execution::TryCall(this, promise_handle(),
+                                     factory()->undefined_value(),
+                                     arraysize(argv), argv, maybe_exception);
+      }
+    }
+  } else {
+    Handle<Object> deferreds(promise_handle_info->deferreds(), this);
+    Handle<Object> argv[] = {value, tasks, deferreds};
+    *result =
+        Execution::TryCall(this, promise_handle(), factory()->undefined_value(),
+                           arraysize(argv), argv, maybe_exception);
+  }
+
+  if (debug()->is_active()) {
+    Handle<Object> after_debug_event(promise_handle_info->after_debug_event(),
+                                     this);
+    if (after_debug_event->IsJSObject()) {
+      debug()->OnAsyncTaskEvent(Handle<JSObject>::cast(after_debug_event));
+    }
+  }
+}
+
 void Isolate::PromiseResolveThenableJob(Handle<PromiseContainer> container,
                                         MaybeHandle<Object>* result,
                                         MaybeHandle<Object>* maybe_exception) {
@@ -3044,8 +3093,9 @@ void Isolate::PromiseResolveThenableJob(Handle<PromiseContainer> container,
 }
 
 void Isolate::EnqueueMicrotask(Handle<Object> microtask) {
+  // TODO(gsathya): remove IsJSFunction?
   DCHECK(microtask->IsJSFunction() || microtask->IsCallHandlerInfo() ||
-         microtask->IsPromiseContainer());
+         microtask->IsPromiseContainer() || microtask->IsPromiseHandleInfo());
   Handle<FixedArray> queue(heap()->microtask_queue(), this);
   int num_tasks = pending_microtask_count();
   DCHECK(num_tasks <= queue->length());
@@ -3097,11 +3147,18 @@ void Isolate::RunMicrotasksInternal() {
         callback(data);
       } else {
         SaveContext save(this);
-        Context* context = microtask->IsJSFunction()
-                               ? Handle<JSFunction>::cast(microtask)->context()
-                               : Handle<PromiseContainer>::cast(microtask)
-                                     ->resolve()
-                                     ->context();
+        Context* context;
+        if (microtask->IsJSFunction()) {
+          context = Handle<JSFunction>::cast(microtask)->context();
+        } else if (microtask->IsPromiseContainer()) {
+          context =
+              Handle<PromiseContainer>::cast(microtask)->resolve()->context();
+        } else {
+          context = Handle<PromiseHandleInfo>::cast(microtask)
+                        ->reaction_context()
+                        ->context();
+        }
+
         set_context(context->native_context());
         handle_scope_implementer_->EnterMicrotaskContext(
             Handle<Context>(context, this));
@@ -3115,9 +3172,12 @@ void Isolate::RunMicrotasksInternal() {
           result = Execution::TryCall(this, microtask_function,
                                       factory()->undefined_value(), 0, NULL,
                                       &maybe_exception);
-        } else {
+        } else if (microtask->IsPromiseContainer()) {
           PromiseResolveThenableJob(Handle<PromiseContainer>::cast(microtask),
                                     &result, &maybe_exception);
+        } else if (microtask->IsPromiseHandleInfo()) {
+          PromiseReactionJob(Handle<PromiseHandleInfo>::cast(microtask),
+                             &result, &maybe_exception);
         }
 
         handle_scope_implementer_->LeaveMicrotaskContext();