C# SocketAsyncEventArgs.StartOperationCommon方法代码示例

 public bool ReceiveAsync(SocketAsyncEventArgs e)
 {
     bool flag;
     int num;
     SocketError error;
     if (s_LoggingEnabled)
     {
         Logging.Enter(Logging.Sockets, this, "ReceiveAsync", "");
     }
     if (this.CleanedUp)
     {
         throw new ObjectDisposedException(base.GetType().FullName);
     }
     e.StartOperationCommon(this);
     e.StartOperationReceive();
     this.BindToCompletionPort();
     SocketFlags socketFlags = e.m_SocketFlags;
     try
     {
         if (e.m_Buffer != null)
         {
             error = UnsafeNclNativeMethods.OSSOCK.WSARecv(this.m_Handle, ref e.m_WSABuffer, 1, out num, ref socketFlags, e.m_PtrNativeOverlapped, IntPtr.Zero);
         }
         else
         {
             error = UnsafeNclNativeMethods.OSSOCK.WSARecv(this.m_Handle, e.m_WSABufferArray, e.m_WSABufferArray.Length, out num, ref socketFlags, e.m_PtrNativeOverlapped, IntPtr.Zero);
         }
     }
     catch (Exception exception)
     {
         e.Complete();
         throw exception;
     }
     if (error != SocketError.Success)
     {
         error = (SocketError) Marshal.GetLastWin32Error();
     }
     if ((error != SocketError.Success) && (error != SocketError.IOPending))
     {
         e.FinishOperationSyncFailure(error, num, socketFlags);
         flag = false;
     }
     else
     {
         flag = true;
     }
     if (s_LoggingEnabled)
     {
         Logging.Exit(Logging.Sockets, this, "ReceiveAsync", flag);
     }
     return flag;
 }

        public bool ReceiveAsync(SocketAsyncEventArgs e)
        {
            bool retval;

            if (s_loggingEnabled)
            {
                Logging.Enter(Logging.Sockets, this, "ReceiveAsync", "");
            }

            if (CleanedUp)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            if (e == null)
            {
                throw new ArgumentNullException("e");
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationReceive();

            // Local vars for sync completion of native call.
            SocketFlags flags;
            int bytesTransferred;
            SocketError socketError;

            // Wrap native methods with try/catch so event args object can be cleaned up.
            try
            {
                socketError = e.DoOperationReceive(_handle, out flags, out bytesTransferred);
            }
            catch (Exception ex)
            {
                // Clear in-use flag on event args object. 
                e.Complete();
                throw ex;
            }

            // Handle completion when completion port is not posted.
            if (socketError != SocketError.Success && socketError != SocketError.IOPending)
            {
                e.FinishOperationSyncFailure(socketError, bytesTransferred, flags);
                retval = false;
            }
            else
            {
                retval = true;
            }

            if (s_loggingEnabled)
            {
                Logging.Exit(Logging.Sockets, this, "ReceiveAsync", retval);
            }
            return retval;
        }

        public bool SendPacketsAsync(SocketAsyncEventArgs e)
        {
            bool retval;

            if (s_loggingEnabled)
            {
                Logging.Enter(Logging.Sockets, this, "SendPacketsAsync", "");
            }

            // Throw if socket disposed
            if (CleanedUp)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            if (e == null)
            {
                throw new ArgumentNullException("e");
            }
            if (e.SendPacketsElements == null)
            {
                throw new ArgumentNullException("e.SendPacketsElements");
            }
            if (!Connected)
            {
                throw new NotSupportedException(SR.net_notconnected);
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationSendPackets();

            // Make the native call.
            SocketError socketError;

            Debug.Assert(e.SendPacketsDescriptorCount != null);

            if (e.SendPacketsDescriptorCount > 0)
            {
                try
                {
                    socketError = e.DoOperationSendPackets(this, _handle);
                }
                catch (Exception)
                {
                    // Clear in-use flag on event args object. 
                    e.Complete();
                    throw;
                }

                // Handle completion when completion port is not posted.
                if (socketError != SocketError.Success && socketError != SocketError.IOPending)
                {
                    e.FinishOperationSyncFailure(socketError, 0, SocketFlags.None);
                    retval = false;
                }
                else
                {
                    retval = true;
                }
            }
            else
            {
                // No buffers or files to send.
                e.FinishOperationSuccess(SocketError.Success, 0, SocketFlags.None);
                retval = false;
            }

            if (s_loggingEnabled)
            {
                Logging.Exit(Logging.Sockets, this, "SendPacketsAsync", retval);
            }

            return retval;
        }

        //
        // SendToAsync
        // 
        public bool SendToAsync(SocketAsyncEventArgs e) {

            bool retval;

            if(s_LoggingEnabled) Logging.Enter(Logging.Sockets, this, "SendToAsync", "");

            // Throw if socket disposed
            if(CleanedUp) {
                throw new ObjectDisposedException(GetType().FullName);
            }

            // Throw if remote endpoint property is null.
            if(e.RemoteEndPoint == null) {
                throw new ArgumentNullException("RemoteEndPoint");
            }

            // Check permissions for connect and prepare SocketAddress
            EndPoint endPointSnapshot = e.RemoteEndPoint;
            e.m_SocketAddress = CheckCacheRemote(ref endPointSnapshot, false);

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationSendTo();
            BindToCompletionPort();

            // Make the native call.
            int bytesTransferred;
            SocketError socketError;

            // Wrap native methods with try/catch so event args object can be cleaned up
            try {
                if(e.m_Buffer != null) {
                    // Single buffer case
                    socketError = UnsafeNclNativeMethods.OSSOCK.WSASendTo(
                                    m_Handle,
                                    ref e.m_WSABuffer,
                                    1,
                                    out bytesTransferred,
                                    e.m_SocketFlags,
                                    e.m_PtrSocketAddressBuffer,
                                    e.m_SocketAddress.m_Size,
                                    e.m_PtrNativeOverlapped,
                                    IntPtr.Zero);
                } else {
                    socketError = UnsafeNclNativeMethods.OSSOCK.WSASendTo(
                                    m_Handle,
                                    e.m_WSABufferArray,
                                    e.m_WSABufferArray.Length,
                                    out bytesTransferred,
                                    e.m_SocketFlags,
                                    e.m_PtrSocketAddressBuffer,
                                    e.m_SocketAddress.m_Size,
                                    e.m_PtrNativeOverlapped,
                                    IntPtr.Zero);


                }
            }
            catch(Exception ex) {
                // clear in-use on event arg object 
                e.Complete();
                throw ex;
            }

            // Native method emits single catch-all error code when error occurs.
            // Must get Win32 error for specific error code.
            if(socketError != SocketError.Success) {
                socketError = (SocketError)Marshal.GetLastWin32Error();
            }

            // Handle completion when completion port is not posted.
            if(socketError != SocketError.Success && socketError != SocketError.IOPending) {
                e.FinishOperationSyncFailure(socketError, bytesTransferred, SocketFlags.None);
                retval = false;
            } else {
                retval = true;
            }

            if(s_LoggingEnabled) Logging.Exit(Logging.Sockets, this, "SendToAsync", retval);

            return retval;
        }

        public bool ConnectAsync(SocketAsyncEventArgs e)
        {
            bool retval;

            if (s_loggingEnabled)
            {
                Logging.Enter(Logging.Sockets, this, "ConnectAsync", "");
            }

            if (CleanedUp)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            if (e == null)
            {
                throw new ArgumentNullException("e");
            }
            if (e._bufferList != null)
            {
                throw new ArgumentException(SR.net_multibuffernotsupported, "BufferList");
            }
            if (e.RemoteEndPoint == null)
            {
                throw new ArgumentNullException("remoteEP");
            }
            if (_isListening)
            {
                throw new InvalidOperationException(SR.net_sockets_mustnotlisten);
            }

            // Check permissions for connect and prepare SocketAddress.
            EndPoint endPointSnapshot = e.RemoteEndPoint;
            DnsEndPoint dnsEP = endPointSnapshot as DnsEndPoint;

            if (dnsEP != null)
            {
                if (s_loggingEnabled)
                {
                    Logging.PrintInfo(Logging.Sockets, "Socket#" + Logging.HashString(this) + "::ConnectAsync " + SR.net_log_socket_connect_dnsendpoint);
                }

                if (dnsEP.AddressFamily != AddressFamily.Unspecified && !CanTryAddressFamily(dnsEP.AddressFamily))
                {
                    throw new NotSupportedException(SR.net_invalidversion);
                }

                MultipleConnectAsync multipleConnectAsync = new SingleSocketMultipleConnectAsync(this, true);

                e.StartOperationCommon(this);
                e.StartOperationWrapperConnect(multipleConnectAsync);

                retval = multipleConnectAsync.StartConnectAsync(e, dnsEP);
            }
            else
            {
                // Throw if remote address family doesn't match socket.
                if (!CanTryAddressFamily(e.RemoteEndPoint.AddressFamily))
                {
                    throw new NotSupportedException(SR.net_invalidversion);
                }

                e._socketAddress = CheckCacheRemote(ref endPointSnapshot, false);

                // Do wildcard bind if socket not bound.
                if (_rightEndPoint == null)
                {
                    if (endPointSnapshot.AddressFamily == AddressFamily.InterNetwork)
                    {
                        InternalBind(new IPEndPoint(IPAddress.Any, 0));
                    }
                    else
                    {
                        InternalBind(new IPEndPoint(IPAddress.IPv6Any, 0));
                    }
                }

                // Save the old RightEndPoint and prep new RightEndPoint.           
                EndPoint oldEndPoint = _rightEndPoint;
                if (_rightEndPoint == null)
                {
                    _rightEndPoint = endPointSnapshot;
                }

                // Prepare for the native call.
                e.StartOperationCommon(this);
                e.StartOperationConnect();

                // Make the native call.
                int bytesTransferred;
                SocketError socketError = SocketError.Success;
                try
                {
                    socketError = e.DoOperationConnect(this, _handle, out bytesTransferred);
                }
                catch (Exception ex)
                {
                    _rightEndPoint = oldEndPoint;

                    // Clear in-use flag on event args object. 
//.........这里部分代码省略.........

        //
        // DisconnectAsync
        // 
        public bool DisconnectAsync(SocketAsyncEventArgs e) {

            bool retval;
            
            if(s_LoggingEnabled) Logging.Enter(Logging.Sockets, this, "DisconnectAsync", "");

            // Throw if socket disposed
            if(CleanedUp) {
                throw new ObjectDisposedException(GetType().FullName);
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationDisconnect();
            BindToCompletionPort();

            // Make the native call.
            SocketError socketError = SocketError.Success;
            try {
                if(!DisconnectEx(
                        m_Handle,
                        e.m_PtrNativeOverlapped,
                        (int)(e.DisconnectReuseSocket ? TransmitFileOptions.ReuseSocket : 0),
                        0)) {
                    socketError = (SocketError)Marshal.GetLastWin32Error();
                }
            }
            catch(Exception ex) {
                // clear in-use on event arg object 
                e.Complete();
                throw ex;
            }

            // Handle completion when completion port is not posted.
            if(socketError != SocketError.Success && socketError != SocketError.IOPending) {
                e.FinishOperationSyncFailure(socketError, 0, SocketFlags.None);
                retval = false;
            } else {
                retval = true;
            }

            if(s_LoggingEnabled) Logging.Exit(Logging.Sockets, this, "DisconnectAsync", retval);

            return retval;
        }

        //
        // ReceiveMessageFromAsync
        // 
        public bool ReceiveMessageFromAsync(SocketAsyncEventArgs e) {

            bool retval;

            if(s_LoggingEnabled) Logging.Enter(Logging.Sockets, this, "ReceiveMessageFromAsync", "");
          
            // Throw if socket disposed
            if(CleanedUp) {
                throw new ObjectDisposedException(GetType().FullName);
            }

            // Throw if remote endpoint property is null.
            if(e.RemoteEndPoint == null) {
                throw new ArgumentNullException("RemoteEndPoint");
            }

            if(!CanTryAddressFamily(e.RemoteEndPoint.AddressFamily)) {
                throw new ArgumentException(SR.GetString(SR.net_InvalidEndPointAddressFamily, 
                    e.RemoteEndPoint.AddressFamily, addressFamily), "RemoteEndPoint");
            }

            // We don't do a CAS demand here because the contents of remoteEP aren't used by
            // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
            // with the right address family
            EndPoint endPointSnapshot = e.RemoteEndPoint;
            e.m_SocketAddress = SnapshotAndSerialize(ref endPointSnapshot);
            // DualMode may have updated the endPointSnapshot, and it has to have the same AddressFamily as 
            // e.m_SocketAddres for Create to work later.
            e.RemoteEndPoint = endPointSnapshot;

            SetReceivingPacketInformation();

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationReceiveMessageFrom();
            BindToCompletionPort();

            
            // Make the native call.
            int bytesTransferred;
            SocketError socketError;

            try {
                socketError = WSARecvMsg(
                    m_Handle,
                    e.m_PtrWSAMessageBuffer,
                    out bytesTransferred,
                    e.m_PtrNativeOverlapped,
                    IntPtr.Zero);
            }
            catch(Exception ex) {
                // clear in-use on event arg object 
                e.Complete();
                throw ex;
            }
            
            // Native method emits single catch-all error code when error occurs.
            // Must get Win32 error for specific error code.
            if(socketError != SocketError.Success) {
                socketError = (SocketError)Marshal.GetLastWin32Error();
            }

            // Handle completion when completion port is not posted.
            if(socketError != SocketError.Success && socketError != SocketError.IOPending) {
                e.FinishOperationSyncFailure(socketError, bytesTransferred, SocketFlags.None);
                retval = false;
            } else {
                retval = true;
            }

            if(s_LoggingEnabled) Logging.Exit(Logging.Sockets, this, "ReceiveMessageFromAsync", retval);
            
            return retval;
        }

 /// <summary>
 /// Begins an asynchronous operation to accept an incoming connection attempt.
 /// </summary>
 /// 
 /// <returns>
 /// Returns true if the I/O operation is pending. The <see cref="E:System.Net.Sockets.SocketAsyncEventArgs.Completed"/> event on the <paramref name="e"/> parameter will be raised upon completion of the operation.Returns false if the I/O operation completed synchronously. The <see cref="E:System.Net.Sockets.SocketAsyncEventArgs.Completed"/> event on the <paramref name="e"/> parameter will not be raised and the <paramref name="e"/> object passed as a parameter may be examined immediately after the method call returns to retrieve the result of the operation.
 /// </returns>
 /// <param name="e">The <see cref="T:System.Net.Sockets.SocketAsyncEventArgs"/> object to use for this asynchronous socket operation.</param><exception cref="T:System.ArgumentException">An argument is not valid. This exception occurs if the buffer provided is not large enough. The buffer must be at least 2 * (sizeof(SOCKADDR_STORAGE + 16) bytes. This exception also occurs if multiple buffers are specified, the <see cref="P:System.Net.Sockets.SocketAsyncEventArgs.BufferList"/> property is not null.</exception><exception cref="T:System.ArgumentOutOfRangeException">An argument is out of range. The exception occurs if the <see cref="P:System.Net.Sockets.SocketAsyncEventArgs.Count"/> is less than 0.</exception><exception cref="T:System.InvalidOperationException">An invalid operation was requested. This exception occurs if the accepting <see cref="T:System.Net.Sockets.Socket"/> is not listening for connections or the accepted socket is bound. You must call the <see cref="M:System.Net.Sockets.Socket.Bind(System.Net.EndPoint)"/> and <see cref="M:System.Net.Sockets.Socket.Listen(System.Int32)"/> method before calling the <see cref="M:System.Net.Sockets.Socket.AcceptAsync(System.Net.Sockets.SocketAsyncEventArgs)"/> method.This exception also occurs if the socket is already connected or a socket operation was already in progress using the specified <paramref name="e"/> parameter. </exception><exception cref="T:System.Net.Sockets.SocketException">An error occurred when attempting to access the socket. See the Remarks section for more information. </exception><exception cref="T:System.NotSupportedException">Windows XP or later is required for this method.</exception><exception cref="T:System.ObjectDisposedException">The <see cref="T:System.Net.Sockets.Socket"/> has been closed. </exception>
 public bool AcceptAsync(SocketAsyncEventArgs e)
 {
     if (Socket.s_LoggingEnabled)
     Logging.Enter(Logging.Sockets, (object) this, "AcceptAsync", "");
       if (this.CleanedUp)
     throw new ObjectDisposedException(this.GetType().FullName);
       if (e.m_BufferList != null)
     throw new ArgumentException(SR.GetString("net_multibuffernotsupported"), "BufferList");
       if (this.m_RightEndPoint == null)
     throw new InvalidOperationException(SR.GetString("net_sockets_mustbind"));
       if (!this.isListening)
     throw new InvalidOperationException(SR.GetString("net_sockets_mustlisten"));
       if (e.AcceptSocket == null)
     e.AcceptSocket = new Socket(this.addressFamily, this.socketType, this.protocolType);
       else if (e.AcceptSocket.m_RightEndPoint != null && !e.AcceptSocket.m_IsDisconnected)
     throw new InvalidOperationException(SR.GetString("net_sockets_namedmustnotbebound", new object[1]
     {
       (object) "AcceptSocket"
     }));
       e.StartOperationCommon(this);
       e.StartOperationAccept();
       this.BindToCompletionPort();
       SocketError socketError = SocketError.Success;
       int bytesReceived;
       try
       {
     if (!this.AcceptEx(this.m_Handle, e.AcceptSocket.m_Handle, e.m_PtrSingleBuffer != IntPtr.Zero ? e.m_PtrSingleBuffer : e.m_PtrAcceptBuffer, e.m_PtrSingleBuffer != IntPtr.Zero ? e.Count - e.m_AcceptAddressBufferCount : 0, e.m_AcceptAddressBufferCount / 2, e.m_AcceptAddressBufferCount / 2, out bytesReceived, (SafeHandle) e.m_PtrNativeOverlapped))
       socketError = (SocketError) Marshal.GetLastWin32Error();
       }
       catch (Exception ex)
       {
     e.Complete();
     throw ex;
       }
       bool flag;
       if (socketError != SocketError.Success && socketError != SocketError.IOPending)
       {
     e.FinishOperationSyncFailure(socketError, bytesReceived, SocketFlags.None);
     flag = false;
       }
       else
     flag = true;
       if (Socket.s_LoggingEnabled)
     Logging.Exit(Logging.Sockets, (object) this, "AcceptAsync", (object) (bool) (flag ? 1 : 0));
       return flag;
 }

 /// <summary>
 /// Begins an asynchronous request for a connection to a remote host.
 /// </summary>
 /// 
 /// <returns>
 /// Returns true if the I/O operation is pending. The <see cref="E:System.Net.Sockets.SocketAsyncEventArgs.Completed"/> event on the <paramref name="e"/> parameter will be raised upon completion of the operation. Returns false if the I/O operation completed synchronously. In this case, The <see cref="E:System.Net.Sockets.SocketAsyncEventArgs.Completed"/> event on the <paramref name="e"/> parameter will not be raised and the <paramref name="e"/> object passed as a parameter may be examined immediately after the method call returns to retrieve the result of the operation.
 /// </returns>
 /// <param name="e">The <see cref="T:System.Net.Sockets.SocketAsyncEventArgs"/> object to use for this asynchronous socket operation.</param><exception cref="T:System.ArgumentException">An argument is not valid. This exception occurs if multiple buffers are specified, the <see cref="P:System.Net.Sockets.SocketAsyncEventArgs.BufferList"/> property is not null. </exception><exception cref="T:System.ArgumentNullException">The <paramref name="e"/> parameter cannot be null and the <see cref="P:System.Net.Sockets.SocketAsyncEventArgs.RemoteEndPoint"/> cannot be null.</exception><exception cref="T:System.InvalidOperationException">The <see cref="T:System.Net.Sockets.Socket"/> is listening or a socket operation was already in progress using the <see cref="T:System.Net.Sockets.SocketAsyncEventArgs"/> object specified in the <paramref name="e"/> parameter.</exception><exception cref="T:System.Net.Sockets.SocketException">An error occurred when attempting to access the socket. See the Remarks section for more information.</exception><exception cref="T:System.NotSupportedException">Windows XP or later is required for this method. This exception also occurs if the local endpoint and the <see cref="P:System.Net.Sockets.SocketAsyncEventArgs.RemoteEndPoint"/> are not the same address family.</exception><exception cref="T:System.ObjectDisposedException">The <see cref="T:System.Net.Sockets.Socket"/> has been closed. </exception><exception cref="T:System.Security.SecurityException">A caller higher in the call stack does not have permission for the requested operation.</exception>
 public bool ConnectAsync(SocketAsyncEventArgs e)
 {
     if (Socket.s_LoggingEnabled)
     Logging.Enter(Logging.Sockets, (object) this, "ConnectAsync", "");
       if (this.CleanedUp)
     throw new ObjectDisposedException(this.GetType().FullName);
       if (e.m_BufferList != null)
     throw new ArgumentException(SR.GetString("net_multibuffernotsupported"), "BufferList");
       if (e.RemoteEndPoint == null)
     throw new ArgumentNullException("remoteEP");
       if (this.isListening)
     throw new InvalidOperationException(SR.GetString("net_sockets_mustnotlisten"));
       EndPoint remoteEndPoint = e.RemoteEndPoint;
       DnsEndPoint endPoint1 = remoteEndPoint as DnsEndPoint;
       bool flag;
       if (endPoint1 != null)
       {
     if (Socket.s_LoggingEnabled)
       Logging.PrintInfo(Logging.Sockets, "Socket#" + ValidationHelper.HashString((object) this) + "::ConnectAsync " + SR.GetString("net_log_socket_connect_dnsendpoint"));
     if (endPoint1.AddressFamily != AddressFamily.Unspecified && !this.CanTryAddressFamily(endPoint1.AddressFamily))
       throw new NotSupportedException(SR.GetString("net_invalidversion"));
     MultipleConnectAsync args = (MultipleConnectAsync) new SingleSocketMultipleConnectAsync(this, true);
     e.StartOperationCommon(this);
     e.StartOperationWrapperConnect(args);
     flag = args.StartConnectAsync(e, endPoint1);
       }
       else
       {
     if (!this.CanTryAddressFamily(e.RemoteEndPoint.AddressFamily))
       throw new NotSupportedException(SR.GetString("net_invalidversion"));
     e.m_SocketAddress = this.CheckCacheRemote(ref remoteEndPoint, false);
     if (this.m_RightEndPoint == null)
     {
       if (remoteEndPoint.AddressFamily == AddressFamily.InterNetwork)
     this.InternalBind((EndPoint) new IPEndPoint(IPAddress.Any, 0));
       else
     this.InternalBind((EndPoint) new IPEndPoint(IPAddress.IPv6Any, 0));
     }
     EndPoint endPoint2 = this.m_RightEndPoint;
     if (this.m_RightEndPoint == null)
       this.m_RightEndPoint = remoteEndPoint;
     e.StartOperationCommon(this);
     e.StartOperationConnect();
     this.BindToCompletionPort();
     SocketError socketError = SocketError.Success;
     int bytesSent;
     try
     {
       if (!this.ConnectEx(this.m_Handle, e.m_PtrSocketAddressBuffer, e.m_SocketAddress.m_Size, e.m_PtrSingleBuffer, e.Count, out bytesSent, (SafeHandle) e.m_PtrNativeOverlapped))
     socketError = (SocketError) Marshal.GetLastWin32Error();
     }
     catch (Exception ex)
     {
       this.m_RightEndPoint = endPoint2;
       e.Complete();
       throw ex;
     }
     if (socketError != SocketError.Success && socketError != SocketError.IOPending)
     {
       e.FinishOperationSyncFailure(socketError, bytesSent, SocketFlags.None);
       flag = false;
     }
     else
       flag = true;
       }
       if (Socket.s_LoggingEnabled)
     Logging.Exit(Logging.Sockets, (object) this, "ConnectAsync", (object) (bool) (flag ? 1 : 0));
       return flag;
 }

        public bool DisconnectAsync(SocketAsyncEventArgs e)
        {
            if (NetEventSource.IsEnabled) NetEventSource.Enter(this);
            bool retval;

            // Throw if socket disposed
            if (CleanedUp)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationDisconnect();

            SocketError socketError = SocketError.Success;
            try
            {
                socketError = e.DoOperationDisconnect(this, _handle);
            }
            catch
            {
                // clear in-use on event arg object 
                e.Complete();
                throw;
            }

            // Handle completion when completion port is not posted.
            if (socketError != SocketError.Success && socketError != SocketError.IOPending)
            {
                e.FinishOperationSyncFailure(socketError, 0, SocketFlags.None);
                retval = false;
            }
            else
            {
                retval = true;
            }

            if (NetEventSource.IsEnabled) NetEventSource.Exit(this, retval);
            return retval;
        }

        public bool SendAsync(SocketAsyncEventArgs e)
        {
            if (NetEventSource.IsEnabled) NetEventSource.Enter(this, e);
            bool retval;

            if (CleanedUp)
            {
                throw new ObjectDisposedException(GetType().FullName);
            }

            if (e == null)
            {
                throw new ArgumentNullException(nameof(e));
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationSend();

            // Local vars for sync completion of native call.
            int bytesTransferred;
            SocketError socketError;

            // Wrap native methods with try/catch so event args object can be cleaned up.
            try
            {
                socketError = e.DoOperationSend(_handle, out bytesTransferred);
            }
            catch
            {
                // Clear in-use flag on event args object. 
                e.Complete();
                throw;
            }

            // Handle completion when completion port is not posted.
            if (socketError != SocketError.Success && socketError != SocketError.IOPending)
            {
                e.FinishOperationSyncFailure(socketError, bytesTransferred, SocketFlags.None);
                retval = false;
            }
            else
            {
                retval = true;
            }

            if (NetEventSource.IsEnabled) NetEventSource.Exit(this, retval);
            return retval;
        }

 public bool SendToAsync(SocketAsyncEventArgs e)
 {
     bool flag;
     int num;
     SocketError error;
     if (s_LoggingEnabled)
     {
         Logging.Enter(Logging.Sockets, this, "SendToAsync", "");
     }
     if (this.CleanedUp)
     {
         throw new ObjectDisposedException(base.GetType().FullName);
     }
     if (e.RemoteEndPoint == null)
     {
         throw new ArgumentNullException("RemoteEndPoint");
     }
     EndPoint remoteEndPoint = e.RemoteEndPoint;
     e.m_SocketAddress = this.CheckCacheRemote(ref remoteEndPoint, false);
     e.StartOperationCommon(this);
     e.StartOperationSendTo();
     this.BindToCompletionPort();
     try
     {
         if (e.m_Buffer != null)
         {
             error = UnsafeNclNativeMethods.OSSOCK.WSASendTo(this.m_Handle, ref e.m_WSABuffer, 1, out num, e.m_SocketFlags, e.m_PtrSocketAddressBuffer, e.m_SocketAddress.m_Size, e.m_PtrNativeOverlapped, IntPtr.Zero);
         }
         else
         {
             error = UnsafeNclNativeMethods.OSSOCK.WSASendTo(this.m_Handle, e.m_WSABufferArray, e.m_WSABufferArray.Length, out num, e.m_SocketFlags, e.m_PtrSocketAddressBuffer, e.m_SocketAddress.m_Size, e.m_PtrNativeOverlapped, IntPtr.Zero);
         }
     }
     catch (Exception exception)
     {
         e.Complete();
         throw exception;
     }
     if (error != SocketError.Success)
     {
         error = (SocketError) Marshal.GetLastWin32Error();
     }
     if ((error != SocketError.Success) && (error != SocketError.IOPending))
     {
         e.FinishOperationSyncFailure(error, num, SocketFlags.None);
         flag = false;
     }
     else
     {
         flag = true;
     }
     if (s_LoggingEnabled)
     {
         Logging.Exit(Logging.Sockets, this, "SendToAsync", flag);
     }
     return flag;
 }

 public bool SendPacketsAsync(SocketAsyncEventArgs e)
 {
     bool flag;
     SocketError success;
     bool flag2;
     if (s_LoggingEnabled)
     {
         Logging.Enter(Logging.Sockets, this, "SendPacketsAsync", "");
     }
     if (this.CleanedUp)
     {
         throw new ObjectDisposedException(base.GetType().FullName);
     }
     if (!this.Connected)
     {
         throw new NotSupportedException(SR.GetString("net_notconnected"));
     }
     e.StartOperationCommon(this);
     e.StartOperationSendPackets();
     this.BindToCompletionPort();
     try
     {
         flag2 = this.TransmitPackets(this.m_Handle, e.m_PtrSendPacketsDescriptor, e.m_SendPacketsElements.Length, e.m_SendPacketsSendSize, e.m_PtrNativeOverlapped, e.m_SendPacketsFlags);
     }
     catch (Exception exception)
     {
         e.Complete();
         throw exception;
     }
     if (!flag2)
     {
         success = (SocketError) Marshal.GetLastWin32Error();
     }
     else
     {
         success = SocketError.Success;
     }
     if ((success != SocketError.Success) && (success != SocketError.IOPending))
     {
         e.FinishOperationSyncFailure(success, 0, SocketFlags.None);
         flag = false;
     }
     else
     {
         flag = true;
     }
     if (s_LoggingEnabled)
     {
         Logging.Exit(Logging.Sockets, this, "SendPacketsAsync", flag);
     }
     return flag;
 }

 public bool ReceiveMessageFromAsync(SocketAsyncEventArgs e)
 {
     bool flag;
     int num;
     SocketError error;
     if (s_LoggingEnabled)
     {
         Logging.Enter(Logging.Sockets, this, "ReceiveMessageFromAsync", "");
     }
     if (this.CleanedUp)
     {
         throw new ObjectDisposedException(base.GetType().FullName);
     }
     if (e.RemoteEndPoint == null)
     {
         throw new ArgumentNullException("RemoteEndPoint");
     }
     if (e.RemoteEndPoint.AddressFamily != this.addressFamily)
     {
         throw new ArgumentException(SR.GetString("net_InvalidEndPointAddressFamily", new object[] { e.RemoteEndPoint.AddressFamily, this.addressFamily }), "RemoteEndPoint");
     }
     EndPoint remoteEndPoint = e.RemoteEndPoint;
     e.m_SocketAddress = this.SnapshotAndSerialize(ref remoteEndPoint);
     this.SetReceivingPacketInformation();
     e.StartOperationCommon(this);
     e.StartOperationReceiveMessageFrom();
     this.BindToCompletionPort();
     try
     {
         error = this.WSARecvMsg(this.m_Handle, e.m_PtrWSAMessageBuffer, out num, e.m_PtrNativeOverlapped, IntPtr.Zero);
     }
     catch (Exception exception)
     {
         e.Complete();
         throw exception;
     }
     if (error != SocketError.Success)
     {
         error = (SocketError) Marshal.GetLastWin32Error();
     }
     if ((error != SocketError.Success) && (error != SocketError.IOPending))
     {
         e.FinishOperationSyncFailure(error, num, SocketFlags.None);
         flag = false;
     }
     else
     {
         flag = true;
     }
     if (s_LoggingEnabled)
     {
         Logging.Exit(Logging.Sockets, this, "ReceiveMessageFromAsync", flag);
     }
     return flag;
 }

        //
        // AcceptAsync
        //        
        public bool AcceptAsync(SocketAsyncEventArgs e) {

            bool retval;

            if(s_LoggingEnabled) Logging.Enter(Logging.Sockets, this, "AcceptAsync", "");
       
            // Throw if socket disposed
            if(CleanedUp) {
               throw new ObjectDisposedException(GetType().FullName);
            }
            
            // Throw if multiple buffers specified.
            if(e.m_BufferList != null) {
                throw new ArgumentException(SR.GetString(SR.net_multibuffernotsupported), "BufferList");
            }
            
            // Throw if not bound.
            if(m_RightEndPoint == null) {
                throw new InvalidOperationException(SR.GetString(SR.net_sockets_mustbind));
            }

            // Throw if not listening.
            if(!isListening) {
                throw new InvalidOperationException(SR.GetString(SR.net_sockets_mustlisten));
            }

            // Handle AcceptSocket property.
            if(e.AcceptSocket == null) {
                // Accept socket not specified - create it.
                e.AcceptSocket = new Socket(addressFamily, socketType, protocolType);
            } else {
                // Validate accept socket for use here.
                if(e.AcceptSocket.m_RightEndPoint != null && !e.AcceptSocket.m_IsDisconnected) {
                    throw new InvalidOperationException(SR.GetString(SR.net_sockets_namedmustnotbebound, "AcceptSocket"));
                }
            }

            // Prepare for the native call.
            e.StartOperationCommon(this);
            e.StartOperationAccept();
            BindToCompletionPort();

            // Local variables for [....] completion.
            int bytesTransferred;
            SocketError socketError = SocketError.Success;

            // Make the native call.
            try {
                if(!AcceptEx(
                        m_Handle,
                        e.AcceptSocket.m_Handle,
                        (e.m_PtrSingleBuffer != IntPtr.Zero) ? e.m_PtrSingleBuffer : e.m_PtrAcceptBuffer,
                        (e.m_PtrSingleBuffer != IntPtr.Zero) ? e.Count - e.m_AcceptAddressBufferCount : 0,
                        e.m_AcceptAddressBufferCount / 2,
                        e.m_AcceptAddressBufferCount / 2,
                        out bytesTransferred,
                        e.m_PtrNativeOverlapped)) {
                    socketError = (SocketError)Marshal.GetLastWin32Error();
                }
            }
            catch (Exception ex) {
                // clear in-use on event arg object 
                e.Complete();
                throw ex;
            }

            // Handle completion when completion port is not posted.
            if(socketError != SocketError.Success && socketError != SocketError.IOPending) {
                e.FinishOperationSyncFailure(socketError, bytesTransferred, SocketFlags.None);
                retval = false;
            } else {
                retval = true;
            }

            if(s_LoggingEnabled) Logging.Exit(Logging.Sockets, this, "AcceptAsync", retval);
            return retval;
        }