Very simple version of Isolates.

tests/isolate/global_error_handler2_test.dart

-// 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.
-
-library test;
-
-import 'package:expect/expect.dart';
-import 'dart:async';
-import 'dart:isolate';
-import "package:async_helper/async_helper.dart";
-
-runTest() {
-  SendPort mainIsolate;
-  bool isFirst = true;
-  port.receive((msg, replyTo) {
-    if (isFirst) {
-      mainIsolate = msg;
-      isFirst = false;
-      throw new UnsupportedError("ignore exception");
-    }
-    Expect.equals("message 2", msg);
-    mainIsolate.send("received");
-  });
-}
-
-bool globalErrorHandler(IsolateUnhandledException e) {
-  return e.source is UnsupportedError && e.source.message == "ignore exception";
-}
-
-main() {
-  // Make sure this test doesn't last longer than 2 seconds.
-  var timer = new Timer(const Duration(seconds: 2), () { throw "failed"; });
-
-  var port = new ReceivePort();
-  SendPort otherIsolate = spawnFunction(runTest, globalErrorHandler);
-  otherIsolate.send(port.toSendPort());
-  otherIsolate.send("message 2");
-  asyncStart();
-  port.receive((msg, replyPort) {
-    Expect.equals("received", msg);
-    port.close();
-    timer.cancel();
-    asyncEnd();
-  });
-}