mcs/class/System/System.Net.Sockets/SocketAsyncResult.cs

   1 // System.Net.Sockets.SocketAsyncResult.cs
   2 //
   3 // Authors:
   4 //      Ludovic Henry <ludovic@xamarin.com>
   5 //
   6 // Copyright (C) 2015 Xamarin, Inc. (https://www.xamarin.com)
   7 //
   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.Collections;
  30 using System.Collections.Generic;
  31 using System.Runtime.InteropServices;
  32 using System.Runtime.Remoting.Messaging;
  33 using System.Threading;
  34
  35 namespace System.Net.Sockets
  36 {
  37         [StructLayout (LayoutKind.Sequential)]
  38         internal sealed class SocketAsyncResult: IOAsyncResult
  39         {
  40                 public Socket socket;
  41                 public SocketOperation operation;
  42
  43                 Exception DelayedException;
  44
  45                 public EndPoint EndPoint;                 // Connect,ReceiveFrom,SendTo
  46                 public byte [] Buffer;                    // Receive,ReceiveFrom,Send,SendTo
  47                 public int Offset;                        // Receive,ReceiveFrom,Send,SendTo
  48                 public int Size;                          // Receive,ReceiveFrom,Send,SendTo
  49                 public SocketFlags SockFlags;             // Receive,ReceiveFrom,Send,SendTo
  50                 public Socket AcceptSocket;               // AcceptReceive
  51                 public IPAddress[] Addresses;             // Connect
  52                 public int Port;                          // Connect
  53                 public IList<ArraySegment<byte>> Buffers; // Receive, Send
  54                 public bool ReuseSocket;                  // Disconnect
  55                 public int CurrentAddress;                // Connect
  56
  57                 public Socket AcceptedSocket;
  58                 public int Total;
  59
  60                 internal int error;
  61
  62                 public int EndCalled;
  63
  64                 public IntPtr Handle {
  65                         get { return socket != null ? socket.Handle : IntPtr.Zero; }
  66                 }
  67
  68                 /* Used by SocketAsyncEventArgs */
  69                 public SocketAsyncResult ()
  70                         : base ()
  71                 {
  72                 }
  73
  74                 public void Init (Socket socket, AsyncCallback callback, object state, SocketOperation operation)
  75                 {
  76                         base.Init (callback, state);
  77
  78                         this.socket = socket;
  79                         this.operation = operation;
  80
  81                         DelayedException = null;
  82
  83                         EndPoint = null;
  84                         Buffer = null;
  85                         Offset = 0;
  86                         Size = 0;
  87                         SockFlags = SocketFlags.None;
  88                         AcceptSocket = null;
  89                         Addresses = null;
  90                         Port = 0;
  91                         Buffers = null;
  92                         ReuseSocket = false;
  93                         CurrentAddress = 0;
  94
  95                         AcceptedSocket = null;
  96                         Total = 0;
  97
  98                         error = 0;
  99
 100                         EndCalled = 0;
 101                 }
 102
 103                 public SocketAsyncResult (Socket socket, AsyncCallback callback, object state, SocketOperation operation)
 104                         : base (callback, state)
 105                 {
 106                         this.socket = socket;
 107                         this.operation = operation;
 108                 }
 109
 110                 public SocketError ErrorCode {
 111                         get {
 112                                 SocketException ex = DelayedException as SocketException;
 113                                 if (ex != null)
 114                                         return ex.SocketErrorCode;
 115
 116                                 if (error != 0)
 117                                         return (SocketError) error;
 118
 119                                 return SocketError.Success;
 120                         }
 121                 }
 122
 123                 public void CheckIfThrowDelayedException ()
 124                 {
 125                         if (DelayedException != null) {
 126                                 socket.is_connected = false;
 127                                 throw DelayedException;
 128                         }
 129
 130                         if (error != 0) {
 131                                 socket.is_connected = false;
 132                                 throw new SocketException (error);
 133                         }
 134                 }
 135
 136                 internal override void CompleteDisposed ()
 137                 {
 138                         Complete ();
 139                 }
 140
 141                 public void Complete ()
 142                 {
 143                         if (operation != SocketOperation.Receive && socket.CleanedUp)
 144                                 DelayedException = new ObjectDisposedException (socket.GetType ().ToString ());
 145
 146                         IsCompleted = true;
 147
 148                         /* It is possible that this.socket is modified by this.Init which has been called by the callback. This
 149                          * would lead to inconsistency, as we would for example not release the correct socket.ReadSem or
 150                          * socket.WriteSem.
 151                          * For example, this can happen with AcceptAsync followed by a ReceiveAsync on the same
 152                          * SocketAsyncEventArgs */
 153                         Socket completedSocket = socket;
 154                         SocketOperation completedOperation = operation;
 155
 156                         AsyncCallback callback = AsyncCallback;
 157                         if (callback != null) {
 158                                 ThreadPool.UnsafeQueueUserWorkItem (_ => callback (this), null);
 159                         }
 160
 161                         /* Warning: any field on the current SocketAsyncResult might have changed, as the callback might have
 162                          * called this.Init */
 163
 164                         switch (completedOperation) {
 165                         case SocketOperation.Receive:
 166                         case SocketOperation.ReceiveFrom:
 167                         case SocketOperation.ReceiveGeneric:
 168                         case SocketOperation.Accept:
 169                                 completedSocket.ReadSem.Release ();
 170                                 break;
 171                         case SocketOperation.Send:
 172                         case SocketOperation.SendTo:
 173                         case SocketOperation.SendGeneric:
 174                                 completedSocket.WriteSem.Release ();
 175                                 break;
 176                         }
 177
 178                         // IMPORTANT: 'callback', if any is scheduled from unmanaged code
 179                 }
 180
 181                 public void Complete (bool synch)
 182                 {
 183                         CompletedSynchronously = synch;
 184                         Complete ();
 185                 }
 186
 187                 public void Complete (int total)
 188                 {
 189                         Total = total;
 190                         Complete ();
 191                 }
 192
 193                 public void Complete (Exception e, bool synch)
 194                 {
 195                         DelayedException = e;
 196                         CompletedSynchronously = synch;
 197                         Complete ();
 198                 }
 199
 200                 public void Complete (Exception e)
 201                 {
 202                         DelayedException = e;
 203                         Complete ();
 204                 }
 205
 206                 public void Complete (Socket s)
 207                 {
 208                         AcceptedSocket = s;
 209                         Complete ();
 210                 }
 211
 212                 public void Complete (Socket s, int total)
 213                 {
 214                         AcceptedSocket = s;
 215                         Total = total;
 216                         Complete ();
 217                 }
 218         }
 219 }