mcs/class/RabbitMQ.Client/src/client/impl/SessionBase.cs

   1 // This source code is dual-licensed under the Apache License, version
   2 // 2.0, and the Mozilla Public License, version 1.1.
   3 //
   4 // The APL v2.0:
   5 //
   6 //---------------------------------------------------------------------------
   7 //   Copyright (C) 2007-2009 LShift Ltd., Cohesive Financial
   8 //   Technologies LLC., and Rabbit Technologies Ltd.
   9 //
  10 //   Licensed under the Apache License, Version 2.0 (the "License");
  11 //   you may not use this file except in compliance with the License.
  12 //   You may obtain a copy of the License at
  13 //
  14 //       http://www.apache.org/licenses/LICENSE-2.0
  15 //
  16 //   Unless required by applicable law or agreed to in writing, software
  17 //   distributed under the License is distributed on an "AS IS" BASIS,
  18 //   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19 //   See the License for the specific language governing permissions and
  20 //   limitations under the License.
  21 //---------------------------------------------------------------------------
  22 //
  23 // The MPL v1.1:
  24 //
  25 //---------------------------------------------------------------------------
  26 //   The contents of this file are subject to the Mozilla Public License
  27 //   Version 1.1 (the "License"); you may not use this file except in
  28 //   compliance with the License. You may obtain a copy of the License at
  29 //   http://www.rabbitmq.com/mpl.html
  30 //
  31 //   Software distributed under the License is distributed on an "AS IS"
  32 //   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
  33 //   License for the specific language governing rights and limitations
  34 //   under the License.
  35 //
  36 //   The Original Code is The RabbitMQ .NET Client.
  37 //
  38 //   The Initial Developers of the Original Code are LShift Ltd,
  39 //   Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd.
  40 //
  41 //   Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd,
  42 //   Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd
  43 //   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
  44 //   Technologies LLC, and Rabbit Technologies Ltd.
  45 //
  46 //   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
  47 //   Ltd. Portions created by Cohesive Financial Technologies LLC are
  48 //   Copyright (C) 2007-2009 Cohesive Financial Technologies
  49 //   LLC. Portions created by Rabbit Technologies Ltd are Copyright
  50 //   (C) 2007-2009 Rabbit Technologies Ltd.
  51 //
  52 //   All Rights Reserved.
  53 //
  54 //   Contributor(s): ______________________________________.
  55 //
  56 //---------------------------------------------------------------------------
  57 using System;
  58
  59 using RabbitMQ.Client;
  60 using RabbitMQ.Client.Events;
  61 using RabbitMQ.Client.Exceptions;
  62
  63 namespace RabbitMQ.Client.Impl
  64 {
  65     public abstract class SessionBase: ISession
  66     {
  67         private CommandHandler m_commandReceived;
  68
  69         private readonly object m_shutdownLock = new object();
  70         private SessionShutdownEventHandler m_sessionShutdown;
  71         public ShutdownEventArgs m_closeReason = null;
  72
  73         public readonly ConnectionBase m_connection;
  74         public readonly int m_channelNumber;
  75
  76         public SessionBase(ConnectionBase connection, int channelNumber)
  77         {
  78             m_connection = connection;
  79             m_channelNumber = channelNumber;
  80             if (channelNumber != 0)
  81                 connection.ConnectionShutdown +=
  82                     new ConnectionShutdownEventHandler(this.OnConnectionShutdown);
  83         }
  84
  85         public virtual void OnCommandReceived(Command cmd)
  86         {
  87             CommandHandler handler = CommandReceived;
  88             if (handler != null)
  89             {
  90                 handler(this, cmd);
  91             }
  92         }
  93
  94         public virtual void OnConnectionShutdown(IConnection conn, ShutdownEventArgs reason)
  95         {
  96             Close(reason);
  97         }
  98
  99         public virtual void OnSessionShutdown(ShutdownEventArgs reason)
 100         {
 101             //Console.WriteLine("Session shutdown "+ChannelNumber+": "+reason);
 102             m_connection.ConnectionShutdown -=
 103                 new ConnectionShutdownEventHandler(this.OnConnectionShutdown);
 104             SessionShutdownEventHandler handler;
 105             lock (m_shutdownLock)
 106             {
 107                 handler = m_sessionShutdown;
 108                 m_sessionShutdown = null;
 109             }
 110             if (handler != null)
 111             {
 112                 handler(this, reason);
 113             }
 114         }
 115
 116         public override string ToString()
 117         {
 118             return this.GetType().Name+"#" + m_channelNumber + ":" + m_connection;
 119         }
 120
 121         //---------------------------------------------------------------------------
 122         // ISession implementation
 123
 124         public CommandHandler CommandReceived
 125         {
 126             get { return m_commandReceived; }
 127             set { m_commandReceived = value; }
 128         }
 129
 130         public event SessionShutdownEventHandler SessionShutdown
 131         {
 132             add
 133             {
 134                 bool ok = false;
 135                 lock (m_shutdownLock)
 136                 {
 137                     if (m_closeReason == null)
 138                     {
 139                         m_sessionShutdown += value;
 140                         ok = true;
 141                     }
 142                 }
 143                 if (!ok)
 144                 {
 145                     value(this, m_closeReason);
 146                 }
 147             }
 148             remove
 149             {
 150                 lock (m_shutdownLock)
 151                 {
 152                     m_sessionShutdown -= value;
 153                 }
 154             }
 155         }
 156
 157         public int ChannelNumber { get { return m_channelNumber; } }
 158
 159         IConnection ISession.Connection { get { return m_connection; } }
 160         public ConnectionBase Connection { get { return m_connection; } }
 161
 162         public ShutdownEventArgs CloseReason { get { return m_closeReason; } }
 163
 164         public bool IsOpen { get { return m_closeReason == null; } }
 165
 166         public abstract void HandleFrame(Frame frame);
 167
 168         public virtual void Transmit(Command cmd)
 169         {
 170             lock (m_shutdownLock)
 171             {
 172                 if (m_closeReason != null)
 173                 {
 174                     if (!m_connection.Protocol.CanSendWhileClosed(cmd))
 175                             throw new AlreadyClosedException(m_closeReason);
 176                 }
 177                 // We transmit *inside* the lock to avoid interleaving
 178                 // of frames within a channel.
 179                 cmd.Transmit(m_channelNumber, m_connection);
 180             }
 181         }
 182
 183         public void Close(ShutdownEventArgs reason)
 184         {
 185             Close(reason, true);
 186         }
 187
 188         public void Close(ShutdownEventArgs reason, bool notify)
 189         {
 190             lock (m_shutdownLock)
 191             {
 192                 if (m_closeReason == null)
 193                 {
 194                     m_closeReason = reason;
 195                 }
 196             }
 197             if (notify)
 198                 OnSessionShutdown(m_closeReason);
 199         }
 200
 201         public void Notify()
 202         {
 203             // Ensure that we notify only when session is already closed
 204             // If not, throw exception, since this is a serious bug in the library
 205             lock (m_shutdownLock)
 206             {
 207                     if (m_closeReason == null)
 208                     throw new Exception("Internal Error in Session.Close");
 209             }
 210             OnSessionShutdown(m_closeReason);
 211         }
 212     }
 213 }