1 //
2 // Mono.WebServer.LingeringNetworkStream
3 //
4 // Authors:
5 //	Gonzalo Paniagua Javier (gonzalo@ximian.com)
6 //
7 // (C) Copyright 2004 Novell, Inc. (http://www.novell.com)
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;
30 using System.Net.Sockets;
31 
32 namespace Mono.WebServer
33 {
34 	public class LingeringNetworkStream : NetworkStream
35 	{
36 		const int USECONDS_TO_LINGER = 2000000;
37 		const int MAX_USECONDS_TO_LINGER = 30000000;
38 		// We dont actually use the data from this buffer. So we cache it...
39 		static byte [] buffer;
40 
LingeringNetworkStream(Socket sock, bool owns)41 		public LingeringNetworkStream (Socket sock, bool owns) : base (sock, owns)
42 		{
43 			EnableLingering = true;
44 			OwnsSocket = owns;
45 		}
46 
47 		public bool OwnsSocket { get; private set; }
48 
49 		public bool EnableLingering { get; set; }
50 
LingeringClose()51 		void LingeringClose ()
52 		{
53 			int waited = 0;
54 
55 			if (!Connected)
56 				return;
57 
58 			try {
59 				Socket.Shutdown (SocketShutdown.Send);
60 				DateTime start = DateTime.UtcNow;
61 				while (waited < MAX_USECONDS_TO_LINGER) {
62 					int nread = 0;
63 					try {
64 						if (!Socket.Poll (USECONDS_TO_LINGER, SelectMode.SelectRead))
65 							break;
66 
67 						if (buffer == null)
68 							buffer = new byte [512];
69 
70 						nread = Socket.Receive (buffer, 0, buffer.Length, 0);
71 					} catch { }
72 
73 					if (nread == 0)
74 						break;
75 
76 					waited += (int) (DateTime.UtcNow - start).TotalMilliseconds * 1000;
77 				}
78 			} catch {
79 				// ignore - we don't care, we're closing anyway
80 			}
81 		}
82 
Close()83 		public override void Close ()
84 		{
85 			if (EnableLingering) {
86 				try {
87 					LingeringClose ();
88 				} finally {
89 					base.Close ();
90 				}
91 			}
92 			else
93 				base.Close ();
94 		}
95 
96 		public bool Connected {
97 			get { return Socket.Connected; }
98 		}
99 	}
100 }
101