Add 'startPaused' option to Isolate.spawn*.

tests/isolate/start_paused_test.dart

+// Copyright (c) 2014, 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 start_paused_test;
+
+import "dart:isolate";
+import "package:expect/expect.dart";
+import "package:async_helper/async_helper.dart";
+
+void isomain(SendPort p) {
+  p.send("DONE");
+}
+
+void notyet(_) {
+  throw "NOT YET";
+}
+
+void main() {
+  test1();
+  test2();
+}
+
+void test1() {
+  // Test that a paused isolate don't send events.

[floitsch, 2014/02/14 14:21:38]

doesn't

[floitsch, 2014/02/14 14:21:38]

Add a small description of how you test:
"We spawn two isolates. One paused the other not. We wait for a reply from the
second isolate before we resume the first isolate.
This is not a full-proof test, since isolates are not required to send messages
in order."

+  asyncStart();

[floitsch, 2014/02/14 14:21:38]

missing asyncEnd

+  RawReceivePort p1 = new RawReceivePort(notyet);
+  Isolate.spawn(isomain, p1.sendPort, startPaused: true)
+         .then((isolate) {
+    RawReceivePort p2;
+    p2 = new RawReceivePort((x) {
+      Expect.equals("DONE", x);
+      p2.close();
+      p1.handler = (x) {
+        Expect.equals("DONE", x);
+        p1.close();
+      };
+      isolate.resume(isolate.pauseCapability);
+    });
+    Isolate.spawn(isomain, p2.sendPort);
+  });
+}
+
+void test2() {
+  // Test that a paused isolate don't send events.

[floitsch, 2014/02/14 14:21:38]

doesn't

+  asyncStart();

[floitsch, 2014/02/14 14:21:38]

missing asyncEnd

+  RawReceivePort p1 = new RawReceivePort(notyet);
+  Isolate.spawn(isomain, p1.sendPort, startPaused: true)
+         .then((isolate) {
+    RawReceivePort p2;
+    Capability c2 = new Capability();
+    // Switch to another pause capability.
+    isolate.pause(c2);
+    isolate.resume(isolate.pauseCapability);
+    p2 = new RawReceivePort((x) {
+      Expect.equals("DONE", x);
+      p2.close();
+      p1.handler = (x) {
+        Expect.equals("DONE", x);
+        p1.close();
+      };
+      isolate.resume(c2);
+    });
+    Isolate.spawn(isomain, p2.sendPort);
+  });
+}