Add Dart_PostPriority function to dart_api, and use it in runAsync to schedule immediate events in …

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
@@ skipping 1039 matching lines @@
   const Object& object = Object::Handle(isolate, Api::UnwrapHandle(handle));
   uint8_t* data = NULL;
   MessageWriter writer(&data, &allocator);
   writer.WriteMessage(object);
   intptr_t len = writer.BytesWritten();
   return PortMap::PostMessage(new Message(
       port_id, Message::kIllegalPort, data, len, Message::kNormalPriority));
 }
 
 
+DART_EXPORT bool Dart_PostPriority(Dart_Port port_id, Dart_Handle handle) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+  const Object& object = Object::Handle(isolate, Api::UnwrapHandle(handle));
+  uint8_t* data = NULL;
+  MessageWriter writer(&data, &allocator);
+  writer.WriteMessage(object);
+  intptr_t len = writer.BytesWritten();
+  return PortMap::PostMessage(new Message(
+      port_id, Message::kIllegalPort, data, len, Message::kFirstPriority));
+}
+
+
 DART_EXPORT Dart_Handle Dart_NewSendPort(Dart_Port port_id) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   CHECK_CALLBACK_STATE(isolate);
   return Api::NewHandle(isolate, DartLibraryCalls::NewSendPort(port_id));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetReceivePort(Dart_Port port_id) {
   Isolate* isolate = Isolate::Current();
@@ skipping 3231 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success();
 }
 
 }  // namespace dart