/// <summary>
/// This method is invoked when an asynchronous send operation completes.
/// The method issues another receive on the socket to read any additional data sent from the client
/// </summary>
private void ProcessSend(SocketAsyncEventArgs e)
{
if (e.SocketError == SocketError.Success)
{
// done echoing data back to the client 完成回传数据回到客户端
AsyncUserToken token = (AsyncUserToken)e.UserToken;
// read the next block of data send from the client 读取从客户端发送的下一个数据块
bool willRaiseEvent = token.UserSocket.ReceiveAsync(e);
if (!willRaiseEvent)
{
ProcessReceive(e);
}
}
else
{
CloseClientSocket(e);
}
}
private void CloseClientSocket(SocketAsyncEventArgs e)
{
AsyncUserToken token = e.UserToken as AsyncUserToken;
// close the socket associated with the client
try
{
token.UserSocket.Shutdown(SocketShutdown.Send);
}
// throws if client process has already closed
catch (Exception) { }
token.UserSocket.Close();
// Free the SocketAsyncEventArg so they can be reused by another client
Interlocked.Decrement(ref m_numConnectedSockets);
m_maxNumberAcceptedClients.Release();
Console.WriteLine("A client has been disconnected from the Server. There are {0} clients connected to the server", m_numConnectedSockets);
// Free the SocketAsyncEventArg so they can be reused by another client
m_readWritePool.Push(e);
}
/// <summary>
/// This method is invoked when an asynchronous receive operation completes.
/// If the remote host closed the connection, then the socket is closed.
/// If data was received then the data is echoed back to the client.
/// </summary>
/// <param name="e"></param>
private void ProcessReceive(SocketAsyncEventArgs e)
{
AsyncUserToken token = (AsyncUserToken)e.UserToken;
// e.BytesTransferred获取套接字操作中传输的字节数。
if (e.BytesTransferred > 0 && e.SocketError == SocketError.Success)
{
// 对两个 32 位整数进行求和并用和替换第一个整数，上述操作作为一个原子操作完成。
Interlocked.Add(ref m_totalBytesRead, e.BytesTransferred);
Console.WriteLine("Server : The server has read a total of {0} bytes", m_totalBytesRead);
//echo the data received back to the client
e.SetBuffer(e.Offset, e.BytesTransferred);
bool willRaiseEvent = token.UserSocket.SendAsync(e);
if (!willRaiseEvent)
{
ProcessSend(e);
}
}
else
{
CloseClientSocket(e);
}
}
