SendPort + ReceivePort changes:

tests/isolate/src/TestFramework.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.
 
 #library("TestFramework");
 #import("dart:coreimpl");
 #import("dart:isolate");
 
 
 typedef void AsynchronousTestFunction(TestExpectation check);
@@ skipping 230 matching lines @@
       }
     });
   }
 
   void tearDown() {
     removeRunning();
   }
 
   void addRunning(TestResult result) {
     if (running++ == 0) {
-      keepalive = new ReceivePort.singleShot();
-      keepalive.receive((message, replyTo) {
+      final port = new ReceivePort();
+      port.receive((message, replyTo) {
+        port.close();
         result.runner.done(result);
       });
+      keepalive = port;
     }
   }
 
   void removeRunning() {
     if (--running == 0) {
       keepalive.toSendPort().send(null, null);
       keepalive = null;
     }
   }
 
   // AsynchronousTestCase.run() calls variable test, not function performTest.
   void performTest() {
     Expect.fail('performTest called in AsynchronousTestCase');
   }
 
   AsynchronousTestFunction test;
 
   static int running = 0;
   static ReceivePort keepalive = null;
 
 }