1 //
2 // Watchdog.cs: A generic watchdog
3 //
4 // Authors:
5 //   Leonardo Taglialegne <leonardo.taglialegne@gmail.com>
6 //
7 // (C) Copyright 2013 Leonardo Taglialegne
8 //
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
16 //
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
19 //
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
27 //
28 
29 using System.Timers;
30 
31 namespace Mono.WebServer.FastCgi
32 {
33 	class Watchdog
34 	{
35 		/// <summary>
36 		/// Gets the timeout.
37 		/// </summary>
38 		/// <value>The timeout, in milliseconds.</value>
39 		public double Timeout {
40 			get;
41 			private set;
42 		}
43 
44 		public event ElapsedEventHandler End;
45 
46 		Timer timer;
47 
48 		readonly object end_lock = new object ();
49 
50 		bool ended;
51 
52 		/// <param name="timeout">Timeout, in milliseconds.</param>
Watchdog(double timeout)53 		public Watchdog(double timeout)
54 		{
55 			Timeout = timeout;
56 			timer = CreateTimer (timeout);
57 		}
58 
Kick()59 		public void Kick()
60 		{
61 			lock (end_lock) {
62 				if (ended)
63 					return;
64 
65 				timer.Dispose ();
66 				timer = CreateTimer (Timeout);
67 			}
68 		}
69 
CreateTimer(double timeout)70 		Timer CreateTimer (double timeout)
71 		{
72 			var toret = new Timer (timeout) {
73 				AutoReset = false
74 			};
75 			toret.Elapsed += (sender, args) =>  {
76 				lock (end_lock) {
77 					ended = true;
78 				}
79 				if (End != null)
80 					End (sender, args);
81 			};
82 			toret.Start ();
83 			return toret;
84 		}
85 	}
86 }
87