Adds a special case for sending an int over a port with the native API.

runtime/lib/isolate.cc

 // Copyright (c) 2012, 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_native_api.h"
 #include "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
@@ skipping 88 matching lines @@
   int32_t hash = (hi ^ lo) & kSmiMax;
   return Smi::New(hash);
 }
 
 
 DEFINE_NATIVE_ENTRY(SendPortImpl_sendInternal_, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(SendPort, port, arguments->NativeArgAt(0));
   // TODO(iposva): Allow for arbitrary messages to be sent.
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, obj, arguments->NativeArgAt(1));
 
-  uint8_t* data = NULL;
-
   const Dart_Port destination_port_id = port.Id();
   const bool can_send_any_object = isolate->origin_id() == port.origin_id();
 
-  MessageWriter writer(&data, &allocator, can_send_any_object);
-  writer.WriteMessage(obj);
+  if (obj.IsSmi() || obj.InVMHeap()) {
+    PortMap::PostMessage(new Message(destination_port_id,
+                                     reinterpret_cast<uint8_t*>(obj.raw()), 0,
+                                     Message::kNormalPriority));
+  } else {
+    uint8_t* data = NULL;
+    MessageWriter writer(&data, &allocator, can_send_any_object);
+    writer.WriteMessage(obj);
 
-  // TODO(turnidge): Throw an exception when the return value is false?
-  PortMap::PostMessage(new Message(destination_port_id,
-                                   data, writer.BytesWritten(),
-                                   Message::kNormalPriority));
+    // TODO(turnidge): Throw an exception when the return value is false?
+    PortMap::PostMessage(new Message(destination_port_id,
+                                     data, writer.BytesWritten(),
+                                     Message::kNormalPriority));
+  }
   return Object::null();
 }
 
 
 static void ThrowIsolateSpawnException(const String& message) {
   const Array& args = Array::Handle(Array::New(1));
   args.SetAt(0, message);
   Exceptions::ThrowByType(Exceptions::kIsolateSpawn, args);
 }
 
@@ skipping 288 matching lines @@
   MessageWriter writer(&data, &allocator, false);
   writer.WriteMessage(msg);
 
   PortMap::PostMessage(new Message(port.Id(),
                                    data, writer.BytesWritten(),
                                    Message::kOOBPriority));
   return Object::null();
 }
 
 }  // namespace dart