isolates refactor: this change introduces 'dart:isolate' as a library. This is a

lib/isolate/runtime/ports.dart

 // Copyright (c) 2011, 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.
 

[siva, 2012/02/22 00:58:20]

Ditto comment about moving this out of 'runtime'

Another question, should ReceivePort, SendPort etc. be part of the Isolate
library or should they be considered corelib features. (the io library uses
ReceivePort and I noticed you had to import 'dart:isolate' in io.dart).

[Siggi Cherem (dart-lang), 2012/02/22 19:18:50]

Done
I think they should be considered part of the isolate library. I'd like to make
it easy to see that a library (e.g. io) is interacting with other isolates. If
ports are part of the isolate library, we can tell if there is any interaction
by looking at the imports.

This happens to be important for frog. To make sure we generate small code for
small programs (e.g. hello world), it is necessary to detect if a program
interacts with any other isolate. If it doesn't, there is a lot of
isolate-machinery that we don't need to include in the generated code. For
example, 'helloworld' can be compiled to be < 1K today, but if we include the
isolate machinery, it becomes 10K. Today, we use adhoc tricks to detect whether
or not the program is interacting with other isolates. With this change, the
detection will be cleaner and less brittle.

 class ReceivePortFactory {
   factory ReceivePort() {
     return new ReceivePortImpl();
   }
 
   factory ReceivePort.singleShot() {
     return new ReceivePortSingleShotImpl();
   }
 }
 
@@ skipping 118 matching lines @@
 
   // Forward the implementation of sending messages to the VM. Only port ids
   // are being handed to the VM.
   static _sendInternal(int sendId, int replyId, var message)
       native "SendPortImpl_sendInternal_";
 
   final int _id;
 }
 
 
-class IsolateNatives {
-  static Future<SendPort> spawn(Isolate isolate, bool isLight) {
-    Completer<SendPort> completer = new Completer<SendPort>();
-    SendPort port = _start(isolate, isLight);
-    completer.complete(port);
-    return completer.future;
-  }
-
-  // Starts a new isolate calling the run method on a new instance of the
-  // remote class's type.
-  // Returns the send port which is passed to the newly created isolate.
-  // This method is being dispatched to from the public core library code.
-  static SendPort _start(Isolate isolate, bool light)
-      native "IsolateNatives_start";
-}