Add isActive field on Timer.

BUG= http://dartbug.com/10010
R=floitsch@google.com

Review URL: https://codereview.chromium.org//18325006

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@24678 260f80e4-7a28-3924-810f-c04153c831b5

sdk/lib/_internal/lib/isolate_helper.dart

@@ -1360,6 +1360,16 @@ class TimerImpl implements Timer {
   TimerImpl(int milliseconds, void callback())
       : _once = true {
     if (milliseconds == 0 && (!hasTimer() || _globalState.isWorker)) {
+
+      void internalCallback() {
+        _handle = null;
+        callback();
+      }
+
+      // Setting _handle to something different from null indicates that the
+      // callback has not been run. Hence, the choice of 1 is arbitrary.
+      _handle = 1;
+
       // This makes a dependency between the async library and the
       // event loop of the isolate library. The compiler makes sure
       // that the event loop is compiled if [Timer] is used.
@@ -1367,15 +1377,17 @@ class TimerImpl implements Timer {
       // loop instead of setTimeout, to make sure the futures get executed in
       // order.
       _globalState.topEventLoop.enqueue(
-          _globalState.currentContext, callback, 'timer');
+          _globalState.currentContext, internalCallback, 'timer');
       _inEventLoop = true;
     } else if (hasTimer()) {
-      _globalState.topEventLoop.activeTimerCount++;
+
       void internalCallback() {
-        callback();
         _handle = null;
         _globalState.topEventLoop.activeTimerCount--;
+        callback();
       }
+
+      _globalState.topEventLoop.activeTimerCount++;
       _handle = JS('int', '#.setTimeout(#, #)',
                    globalThis,
                    convertDartClosureToJS(internalCallback, 0),
@@ -1416,6 +1428,8 @@ class TimerImpl implements Timer {
       throw new UnsupportedError("Canceling a timer.");
     }
   }
+
+  bool get isActive => _handle != null;
 }
 
 bool hasTimer() => JS('', '#.setTimeout', globalThis) != null;

sdk/lib/async/timer.dart

@@ -57,6 +57,16 @@ abstract class Timer {
    * Cancels the timer.
    */
   void cancel();
+
+  /**
+   * Returns whether the timer is still active.
+   *
+   * A non-periodic timer is active if the callback has not been executed,
+   * and the timer has not been canceled.
+   *
+   * A periodic timer is active if it has not been canceled.
+   */
+  bool get isActive;
 }
 
 external Timer _createTimer(Duration duration, void callback());

sdk/lib/async/zone.dart

@@ -436,7 +436,6 @@ class _ZoneTimer implements Timer {
   final _Zone _zone;
   final _TimerCallback _callback;
   Timer _timer;
-  bool _isDone = false;
 
   _ZoneTimer(this._zone, Duration duration, this._callback) {
     _zone.expectCallback();
@@ -444,15 +443,15 @@ class _ZoneTimer implements Timer {
   }
 
   void _run() {
-    _isDone = true;
     _zone.executeCallbackGuarded(_callback);
   }
 
   void cancel() {
-    if (!_isDone) _zone.cancelCallbackExpectation();
-    _isDone = true;
+    if (_timer.isActive) _zone.cancelCallbackExpectation();
     _timer.cancel();
   }
+
+  bool get isActive => _timer.isActive;
 }
 
 typedef void _PeriodicTimerCallback(Timer timer);
@@ -464,7 +463,6 @@ class _PeriodicZoneTimer implements Timer {
   final _Zone _zone;
   final _PeriodicTimerCallback _callback;
   Timer _timer;
-  bool _isDone = false;
 
   _PeriodicZoneTimer(this._zone, Duration duration, this._callback) {
     _zone.expectCallback();
@@ -477,10 +475,11 @@ class _PeriodicZoneTimer implements Timer {
   }
 
   void cancel() {
-    if (!_isDone) _zone.cancelCallbackExpectation();
-    _isDone = true;
+    if (_timer.isActive) _zone.cancelCallbackExpectation();
     _timer.cancel();
   }
+
+  bool get isActive => _timer.isActive;
 }
 
 /**

sdk/lib/html/dartium/html_dartium.dart

@@ -31009,31 +31009,44 @@ final _pureIsolatePrintClosure = (s) {
 
 final _forwardingPrintClosure = _Utils.forwardingPrint;
 
-class _Timer implements Timer {
-  final canceller;
+ class _Timer implements Timer {
+  final _canceler;
 
-  _Timer(this.canceller);
+  _Timer(int milliSeconds, void callback(Timer timer), bool repeating) {
 
-  void cancel() { canceller(); }
+    if (repeating) {
+      int id = window._setInterval(() {
+        _canceler = null;
+        callback(this);
+      }, milliSeconds);)
+      _canceler = () => window._clearInterval(id);
+    } else {
+      int id = window._setTimeout(() {
+        _canceler = null;
+        callback(this);
+      }, milliSeconds); )
+      _canceler = window._clearTimeout(id);
+    }
+  }
+
+  void cancel() {
+    if (_canceler != null) {
+      _canceler();
+    }
+    _canceler = null;
+  }
+
+  bool get isActive => _canceler != null;
 }
 
-get _timerFactoryClosure => (int milliSeconds, void callback(Timer timer), bool repeating) {
-  var maker;
-  var canceller;
-  if (repeating) {
-    maker = window._setInterval;
-    canceller = window._clearInterval;
-  } else {
-    maker = window._setTimeout;
-    canceller = window._clearTimeout;
-  }
-  Timer timer;
-  final int id = maker(() { callback(timer); }, milliSeconds);
-  timer = new _Timer(() { canceller(id); });
-  return timer;
+get _timerFactoryClosure =>
+    (int milliSeconds, void callback(Timer timer), bool repeating) {
+  return new _Timer(milliseconds, callback, repeating);
 };
 
+
 class _PureIsolateTimer implements Timer {
+  bool _isDone = false;
   final ReceivePort _port = new ReceivePort();
   SendPort _sendPort; // Effectively final.
 
@@ -31043,6 +31056,7 @@ class _PureIsolateTimer implements Timer {
     _sendPort = _port.toSendPort();
     _port.receive((msg, replyTo) {
       assert(msg == _TIMER_PING);
+      _isDone = !repeating;
       callback(this);
       if (!repeating) _cancel();
     });
@@ -31056,12 +31070,15 @@ class _PureIsolateTimer implements Timer {
   }
 
   void _cancel() {
+    _isDone = true;
     _port.close();
   }
 
   _send(msg) {
     _sendToHelperIsolate(msg, _sendPort);
   }
+
+  bool get isActive => !_isDone;
 }
 
 get _pureIsolateTimerFactoryClosure =>

sdk/lib/io/timer_impl.dart

@@ -50,6 +50,7 @@ class _Timer extends LinkedListEntry<_Timer> implements Timer {
 
   bool get _repeating => _milliSeconds >= 0;
 
+  bool get isActive => _callback != null;
 
   // Cancels a set timer. The timer is removed from the timer list and if
   // the given timer is the earliest timer the native timer is reset.
@@ -143,7 +144,12 @@ class _Timer extends LinkedListEntry<_Timer> implements Timer {
           // one of the later timers which will set the callback to
           // null.
           if (timer._callback != null) {
-            timer._callback(timer);
+            var callback = timer._callback;
+            if (!timer._repeating) {
+              //Mark timer as inactive.
+              timer._callback = null;
+            }
+            callback(timer);
             // Re-insert repeating timer if not canceled.
             if (timer._repeating && timer._callback != null) {
               timer._advanceWakeupTime();

tests/lib/async/timer_isActive_test.dart

@@ -0,0 +1,45 @@
+// 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.
+
+import 'dart:async';
+import '../../../pkg/unittest/lib/unittest.dart';
+
+main() {
+
+  test("timer isActive test", () {
+    Timer t;
+
+    t = new Timer(const Duration(seconds: 1),
+                  expectAsync0(() => expect(t.isActive, equals(false))));
+    expect(t.isActive, equals(true));
+  });
+
+  test("periodic timer cancel test", () {
+    Timer t;
+
+    int i = 0;
+    void checkActive(Timer timer) {
+      expect(t.isActive, equals(true));
+      if (i == 2) {
+        t.cancel();
+        expect(t.isActive, equals(false));
+      }
+      i++;
+    }
+
+    t = new Timer.periodic(new Duration(milliseconds: 1),
+                           expectAsync1(checkActive, count: 3));
+    expect(t.isActive, equals(true));
+  });
+
+  test("timer cancel test", () {
+    Timer timer = new Timer(const Duration(seconds: 1),
+                            () => fail("Should not be reached."));
+    Timer.run(expectAsync0(() {
+      expect(timer.isActive, equals(true));
+      timer.cancel();
+      expect(timer.isActive, equals(false));
+    }));
+  });
+}

tests/lib/lib.status

@@ -59,6 +59,7 @@ async/stream_periodic4_test: Fail # Timer interface not supported; dartbug.com/7
 async/stream_periodic5_test: Fail # Timer interface not supported; dartbug.com/7728.
 async/run_zoned7_test: Fail # Timer interface not supported: dartbug.com/7728.
 async/catch_errors22_test: Fail # Timer interface not supported: dartbug.com/7728.
+async/timer_isActive_test: Fail # Timer interface not supported: dartbug.com/7728.
 
 [ $compiler == dart2js && $browser ]
 async/timer_not_available_test: Fail, OK # only meant to test when there is no way to

tools/dom/src/native_DOMImplementation.dart

@@ -198,31 +198,43 @@ final _pureIsolatePrintClosure = (s) {
 
 final _forwardingPrintClosure = _Utils.forwardingPrint;
 
-class _Timer implements Timer {
-  final canceller;
+ class _Timer implements Timer{
+  var _canceler;
 
-  _Timer(this.canceller);
+  _Timer(int milliSeconds, void callback(Timer timer), bool repeating) {
 
-  void cancel() { canceller(); }
+    if (repeating) {
+      int id = window._setInterval(() {
+        callback(this);
+      }, milliSeconds);)
+      _canceler = () => window._clearInterval(id);
+    } else {
+      int id = window._setTimeout(() {
+        _canceler = null;
+        callback(this);
+      }, milliSeconds);)
+      _canceler = () => window._clearTimeout(id);
+    }
+  }
+
+  void cancel() {
+    if (_canceler != null) {
+      _canceler();
+    }
+    _canceler = null;
+  }
+
+  bool get isActive => _canceler != null;
 }
 
-get _timerFactoryClosure => (int milliSeconds, void callback(Timer timer), bool repeating) {
-  var maker;
-  var canceller;
-  if (repeating) {
-    maker = window._setInterval;
-    canceller = window._clearInterval;
-  } else {
-    maker = window._setTimeout;
-    canceller = window._clearTimeout;
-  }
-  Timer timer;
-  final int id = maker(() { callback(timer); }, milliSeconds);
-  timer = new _Timer(() { canceller(id); });
-  return timer;
+get _timerFactoryClosure =>
+    (int milliSeconds, void callback(Timer timer), bool repeating) {
+  return new _Timer(milliseconds, callback, repeating);
 };
 
+
 class _PureIsolateTimer implements Timer {
+  bool _isActive = true;
   final ReceivePort _port = new ReceivePort();
   SendPort _sendPort; // Effectively final.
 
@@ -232,6 +244,7 @@ class _PureIsolateTimer implements Timer {
     _sendPort = _port.toSendPort();
     _port.receive((msg, replyTo) {
       assert(msg == _TIMER_PING);
+      _isActive = repeating;
       callback(this);
       if (!repeating) _cancel();
     });
@@ -245,12 +258,15 @@ class _PureIsolateTimer implements Timer {
   }
 
   void _cancel() {
+    _isActive = false;
     _port.close();
   }
 
   _send(msg) {
     _sendToHelperIsolate(msg, _sendPort);
   }
+
+  bool get isActive => _isActive;
 }
 
 get _pureIsolateTimerFactoryClosure =>