- First step in refactoring ports with the goal of moving

runtime/lib/isolate_patch.dart

 // 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.
 
 import "dart:collection" show HashMap;
 
 patch class ReceivePort {
   /* patch */ factory ReceivePort() = _ReceivePortImpl;
 
   /* patch */ factory ReceivePort.fromRawReceivePort(RawReceivePort rawPort) =
@@ skipping 66 matching lines @@
 
 class _RawReceivePortImpl implements RawReceivePort {
   factory _RawReceivePortImpl() native "RawReceivePortImpl_factory";
 
   close() {
     _portMap.remove(_id);
     _closeInternal(_id);
   }
 
   SendPort get sendPort {
-    return new _SendPortImpl(_id);
+    return new _SendPortImpl._from(this);
   }
 
   /**** Internal implementation details ****/
   // Called from the VM to create a new RawReceivePort instance.
-  static _RawReceivePortImpl _get_or_create(int id) {
-    _RawReceivePortImpl port = _portMap[id];
-    if (port != null) {
-      return port;
-    }
+  static _RawReceivePortImpl _get(int id) {
+    return _portMap[id];
+  }
+
+  static _RawReceivePortImpl _create(int id) {
+    assert(_portMap[id]== null);
     return new _RawReceivePortImpl._internal(id);
   }
 
   _RawReceivePortImpl._internal(int id) : _id = id {
     _portMap[id] = this;
   }
 
   // Called from the VM to retrieve the RawReceivePort for a message.
   static _RawReceivePortImpl _lookupReceivePort(int id) {
     return _portMap[id];
@@ skipping 43 matching lines @@
     int hash = _id;
     hash = (hash + ((hash & (MASK >> 10)) << 10)) & MASK;
     hash ^= (hash >> 6);
     hash = (hash + ((hash & (MASK >> 3)) << 3)) & MASK;
     hash ^= (hash >> 11);
     hash = (hash + ((hash & (MASK >> 15)) << 15)) & MASK;
     return hash;
   }
 
   /*--- private implementation ---*/
-  const _SendPortImpl(int id) : _id = id;
+  _SendPortImpl._from(_RawReceivePortImpl from) : _id = from._id;
+  _SendPortImpl._with(int id) : _id = id;
 
   // _SendPortImpl._create is called from the VM when a new SendPort instance is
   // needed by the VM code.
   static SendPort _create(int id) {
-    return new _SendPortImpl(id);
+    return new _SendPortImpl._with(id);
   }
 
   // Forward the implementation of sending messages to the VM. Only port ids
   // are being handed to the VM.
   static _sendInternal(int sendId, var message)
       native "SendPortImpl_sendInternal_";
 
   final int _id;
 }
 
@@ skipping 98 matching lines @@
       native "Isolate_spawnFunction";
 
   static SendPort _spawnUri(String uri) native "Isolate_spawnUri";
 }
 
 patch class Capability {
   /* patch */ factory Capability() {
     throw new UnimplementedError();
   }
 }