mcs/class/System/System.Timers/Timer.cs

   1 //
   2 // System.Timers.Timer
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   8 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // The docs talk about server timers and such...
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.ComponentModel;
  34 using System.Threading;
  35
  36 namespace System.Timers
  37 {
  38         [DefaultEventAttribute("Elapsed")]
  39         [DefaultProperty("Interval")]
  40         public class Timer : Component, ISupportInitialize {
  41                 double interval;
  42                 bool autoReset;
  43                 System.Threading.Timer timer;
  44                 object _lock = new object ();
  45                 ISynchronizeInvoke so;
  46
  47                 [Category("Behavior")]
  48                 [TimersDescription("Occurs when the Interval has elapsed.")]
  49                 public event ElapsedEventHandler Elapsed;
  50
  51                 public Timer () : this (100)
  52                 {
  53                 }
  54
  55                 public Timer (double interval)
  56                 {
  57                         // MSBUG: https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=296761
  58                         if (interval > 0x7FFFFFFF)
  59                                 throw new ArgumentException ("Invalid value: " + interval, "interval");
  60
  61                         autoReset = true;
  62                         Interval = interval;
  63                 }
  64
  65                 [Category("Behavior")]
  66                 [DefaultValue(true)]
  67                 [TimersDescription("Indicates whether the timer will be restarted when it is enabled.")]
  68                 public bool AutoReset
  69                 {
  70                         get { return autoReset; }
  71                         set { autoReset = value; }
  72                 }
  73
  74                 [Category("Behavior")]
  75                 [DefaultValue(false)]
  76                 [TimersDescription("Indicates whether the timer is enabled to fire events at a defined interval.")]
  77                 public bool Enabled
  78                 {
  79                         get {
  80                                 lock (_lock)
  81                                         return timer != null;
  82                         }
  83                         set {
  84                                 lock (_lock) {
  85                                         bool enabled = timer != null;
  86                                         if (enabled == value)
  87                                                 return;
  88
  89                                         if (value) {
  90                                                 timer = new System.Threading.Timer (Callback, this, (int)interval, autoReset ? (int)interval: 0);
  91                                         } else {
  92                                                 timer.Dispose ();
  93                                                 timer = null;
  94                                         }
  95                                 }
  96                         }
  97                 }
  98
  99                 [Category("Behavior")]
 100                 [DefaultValue(100)]
 101                 [RecommendedAsConfigurable(true)]
 102                 [TimersDescription( "The number of milliseconds between timer events.")]
 103                 public double Interval
 104                 {
 105                         get { return interval; }
 106                         set {
 107                                 // The doc says 'less than 0', but 0 also throws the exception
 108                                 if (value <= 0)
 109                                         throw new ArgumentException ("Invalid value: " + value);
 110
 111                                 lock (_lock) {
 112                                         interval = value;
 113                                         if (timer != null)
 114                                                 timer.Change ((int)interval, autoReset? (int)interval: 0);
 115                                 }
 116                         }
 117                 }
 118
 119                 public override ISite Site
 120                 {
 121                         get { return base.Site; }
 122                         set { base.Site = value; }
 123                 }
 124
 125                 [DefaultValue(null)]
 126                 [TimersDescriptionAttribute("The object used to marshal the event handler calls issued " +
 127                                             "when an interval has elapsed.")]
 128                 [Browsable (false)]
 129                 public ISynchronizeInvoke SynchronizingObject
 130                 {
 131                         get { return so; }
 132                         set { so = value; }
 133                 }
 134
 135                 public void BeginInit ()
 136                 {
 137                         // Nothing to do
 138                 }
 139
 140                 public void Close ()
 141                 {
 142                         Enabled = false;
 143                 }
 144
 145                 public void EndInit ()
 146                 {
 147                         // Nothing to do
 148                 }
 149
 150                 public void Start ()
 151                 {
 152                         Enabled = true;
 153                 }
 154
 155                 public void Stop ()
 156                 {
 157                         Enabled = false;
 158                 }
 159
 160                 protected override void Dispose (bool disposing)
 161                 {
 162                         Close ();
 163                         base.Dispose (disposing);
 164                 }
 165
 166                 static void Callback (object state)
 167                 {
 168                         Timer timer = (Timer) state;
 169                         if (timer.Enabled == false)
 170                                 return;
 171                         ElapsedEventHandler events = timer.Elapsed;
 172                         if (!timer.autoReset)
 173                                 timer.Enabled = false;
 174                         if (events == null)
 175                                 return;
 176
 177                         ElapsedEventArgs arg = new ElapsedEventArgs (DateTime.Now);
 178
 179                         if (timer.so != null && timer.so.InvokeRequired) {
 180                                 timer.so.BeginInvoke (events, new object [2] {timer, arg});
 181                         } else {
 182                                 try {
 183                                         events (timer, arg);
 184                                 } catch {
 185                                 }
 186                         }
 187                 }
 188
 189         }
 190 }