C# 使用.NET的SocketAsyncEventArgs实现高效能多并发TCPSocket通信

简介：

SocketAsyncEventArgs是一个套接字操作得类，主要作用是实现socket消息的异步接收和发送，跟Socket的BeginSend和BeginReceive方法异步处理没有多大区别，它的优势在于完成端口的实现来处理大数据的并发情况。

BufferManager类, 管理传输流的大小
SocketEventPool类: 管理SocketAsyncEventArgs的一个应用池. 有效地重复使用.
AsyncUserToken类: 这个可以根据自己的实际情况来定义.主要作用就是存储客户端的信息.
SocketManager类: 核心,实现Socket监听,收发信息等操作.
额外功能 1.自动检测无效连接并断开 2.自动释放资源

BufferManager类

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Net.Sockets;  
using System.Text;  namespace Plates.Service  
{  class BufferManager  {  int m_numBytes;                 // the total number of bytes controlled by the buffer pool  byte[] m_buffer;                // the underlying byte array maintained by the Buffer Manager  Stack<int> m_freeIndexPool;     //   int m_currentIndex;  int m_bufferSize;  public BufferManager(int totalBytes, int bufferSize)  {  m_numBytes = totalBytes;  m_currentIndex = 0;  m_bufferSize = bufferSize;  m_freeIndexPool = new Stack<int>();  }  // Allocates buffer space used by the buffer pool  public void InitBuffer()  {  // create one big large buffer and divide that   // out to each SocketAsyncEventArg object  m_buffer = new byte[m_numBytes];  }  // Assigns a buffer from the buffer pool to the   // specified SocketAsyncEventArgs object  //  // <returns>true if the buffer was successfully set, else false</returns>  public bool SetBuffer(SocketAsyncEventArgs args)  {  if (m_freeIndexPool.Count > 0)  {  args.SetBuffer(m_buffer, m_freeIndexPool.Pop(), m_bufferSize);  }  else  {  if ((m_numBytes - m_bufferSize) < m_currentIndex)  {  return false;  }  args.SetBuffer(m_buffer, m_currentIndex, m_bufferSize);  m_currentIndex += m_bufferSize;  }  return true;  }  // Removes the buffer from a SocketAsyncEventArg object.    // This frees the buffer back to the buffer pool  public void FreeBuffer(SocketAsyncEventArgs args)  {  m_freeIndexPool.Push(args.Offset);  args.SetBuffer(null, 0, 0);  }  }  
}

SocketEventPool类:

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Net.Sockets;  
using System.Text;  namespace Plates.Service  
{  class SocketEventPool  {  Stack<SocketAsyncEventArgs> m_pool;  public SocketEventPool(int capacity)  {  m_pool = new Stack<SocketAsyncEventArgs>(capacity);  }  public void Push(SocketAsyncEventArgs item)  {  if (item == null) { throw new ArgumentNullException("Items added to a SocketAsyncEventArgsPool cannot be null"); }  lock (m_pool)  {  m_pool.Push(item);  }  }  // Removes a SocketAsyncEventArgs instance from the pool  // and returns the object removed from the pool  public SocketAsyncEventArgs Pop()  {  lock (m_pool)  {  return m_pool.Pop();  }  }  // The number of SocketAsyncEventArgs instances in the pool  public int Count  {  get { return m_pool.Count; }  }  public void Clear()  {  m_pool.Clear();  }  }  
}

AsyncUserToken类

using System;  
using System.Collections;  
using System.Collections.Generic;  
using System.Linq;  
using System.Net;  
using System.Net.Sockets;  
using System.Text;  namespace Plates.Service  
{  class AsyncUserToken  {  /// <summary>  /// 客户端IP地址  /// </summary>  public IPAddress IPAddress { get; set; }  /// <summary>  /// 远程地址  /// </summary>  public EndPoint Remote { get; set; }  /// <summary>  /// 通信SOKET  /// </summary>  public Socket Socket { get; set; }  /// <summary>  /// 连接时间  /// </summary>  public DateTime ConnectTime { get; set; }  /// <summary>  /// 所属用户信息  /// </summary>  public UserInfoModel UserInfo { get; set; }  /// <summary>  /// 数据缓存区  /// </summary>  public List<byte> Buffer { get; set; }  public AsyncUserToken()  {  this.Buffer = new List<byte>();  }  }  
}

SocketManager类

using Plates.Common;  
using System;  
using System.Collections;  
using System.Collections.Generic;  
using System.Linq;  
using System.Net;  
using System.Net.Sockets;  
using System.Text;  
using System.Threading;  namespace Plates.Service  
{  class SocketManager  {  private int m_maxConnectNum;    //最大连接数  private int m_revBufferSize;    //最大接收字节数  BufferManager m_bufferManager;  const int opsToAlloc = 2;  Socket listenSocket;            //监听Socket  SocketEventPool m_pool;  int m_clientCount;              //连接的客户端数量  Semaphore m_maxNumberAcceptedClients;  List<AsyncUserToken> m_clients; //客户端列表  #region 定义委托  /// <summary>  /// 客户端连接数量变化时触发  /// </summary>  /// <param name="num">当前增加客户的个数(用户退出时为负数,增加时为正数,一般为1)</param>  /// <param name="token">增加用户的信息</param>  public delegate void OnClientNumberChange(int num, AsyncUserToken token);  /// <summary>  /// 接收到客户端的数据  /// </summary>  /// <param name="token">客户端</param>  /// <param name="buff">客户端数据</param>  public delegate void OnReceiveData(AsyncUserToken token, byte[] buff);  #endregion  #region 定义事件  /// <summary>  /// 客户端连接数量变化事件  /// </summary>  public event OnClientNumberChange ClientNumberChange;  /// <summary>  /// 接收到客户端的数据事件  /// </summary>  public event OnReceiveData ReceiveClientData;  #endregion  #region 定义属性  /// <summary>  /// 获取客户端列表  /// </summary>  public List<AsyncUserToken> ClientList { get { return m_clients; } }  #endregion  /// <summary>  /// 构造函数  /// </summary>  /// <param name="numConnections">最大连接数</param>  /// <param name="receiveBufferSize">缓存区大小</param>  public SocketManager(int numConnections, int receiveBufferSize)  {  m_clientCount = 0;  m_maxConnectNum = numConnections;  m_revBufferSize = receiveBufferSize;  // allocate buffers such that the maximum number of sockets can have one outstanding read and   //write posted to the socket simultaneously    m_bufferManager = new BufferManager(receiveBufferSize * numConnections * opsToAlloc, receiveBufferSize);  m_pool = new SocketEventPool(numConnections);  m_maxNumberAcceptedClients = new Semaphore(numConnections, numConnections);  }  /// <summary>  /// 初始化  /// </summary>  public void Init()  {  // Allocates one large byte buffer which all I/O operations use a piece of.  This gaurds   // against memory fragmentation  m_bufferManager.InitBuffer();  m_clients = new List<AsyncUserToken>();  // preallocate pool of SocketAsyncEventArgs objects  SocketAsyncEventArgs readWriteEventArg;  for (int i = 0; i < m_maxConnectNum; i++)  {  readWriteEventArg = new SocketAsyncEventArgs();  readWriteEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(IO_Completed);  readWriteEventArg.UserToken = new AsyncUserToken();  // assign a byte buffer from the buffer pool to the SocketAsyncEventArg object  m_bufferManager.SetBuffer(readWriteEventArg);  // add SocketAsyncEventArg to the pool  m_pool.Push(readWriteEventArg);  }  }  /// <summary>  /// 启动服务  /// </summary>  /// <param name="localEndPoint"></param>  public bool Start(IPEndPoint localEndPoint)  {  try  {  m_clients.Clear();  listenSocket = new Socket(localEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);  listenSocket.Bind(localEndPoint);  // start the server with a listen backlog of 100 connections  listenSocket.Listen(m_maxConnectNum);  // post accepts on the listening socket  StartAccept(null);  return true;  }  catch (Exception)  {  return false;  }  }  /// <summary>  /// 停止服务  /// </summary>  public void Stop()  {  foreach (AsyncUserToken token in m_clients)  {  try  {  token.Socket.Shutdown(SocketShutdown.Both);  }  catch (Exception) { }  }  try  {  listenSocket.Shutdown(SocketShutdown.Both);  }  catch (Exception) { }  listenSocket.Close();  int c_count = m_clients.Count;  lock (m_clients) { m_clients.Clear(); }  if (ClientNumberChange != null)  ClientNumberChange(-c_count, null);  }  public void CloseClient(AsyncUserToken token)  {  try  {  token.Socket.Shutdown(SocketShutdown.Both);  }  catch (Exception) { }  }  // Begins an operation to accept a connection request from the client   //  // <param name="acceptEventArg">The context object to use when issuing   // the accept operation on the server's listening socket</param>  public void StartAccept(SocketAsyncEventArgs acceptEventArg)  {  if (acceptEventArg == null)  {  acceptEventArg = new SocketAsyncEventArgs();  acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(AcceptEventArg_Completed);  }  else  {  // socket must be cleared since the context object is being reused  acceptEventArg.AcceptSocket = null;  }  m_maxNumberAcceptedClients.WaitOne();  if (!listenSocket.AcceptAsync(acceptEventArg))  {  ProcessAccept(acceptEventArg);  }  }  // This method is the callback method associated with Socket.AcceptAsync   // operations and is invoked when an accept operation is complete  //  void AcceptEventArg_Completed(object sender, SocketAsyncEventArgs e)  {  ProcessAccept(e);  }  private void ProcessAccept(SocketAsyncEventArgs e)  {  try  {  Interlocked.Increment(ref m_clientCount);  // Get the socket for the accepted client connection and put it into the   //ReadEventArg object user token  SocketAsyncEventArgs readEventArgs = m_pool.Pop();  AsyncUserToken userToken = (AsyncUserToken)readEventArgs.UserToken;  userToken.Socket = e.AcceptSocket;  userToken.ConnectTime = DateTime.Now;  userToken.Remote = e.AcceptSocket.RemoteEndPoint;  userToken.IPAddress = ((IPEndPoint)(e.AcceptSocket.RemoteEndPoint)).Address;  lock (m_clients) { m_clients.Add(userToken); }  if (ClientNumberChange != null)  ClientNumberChange(1, userToken);  if (!e.AcceptSocket.ReceiveAsync(readEventArgs))  {  ProcessReceive(readEventArgs);  }  }  catch (Exception me)  {  RuncomLib.Log.LogUtils.Info(me.Message + "\r\n" + me.StackTrace);  }  // Accept the next connection request  if (e.SocketError == SocketError.OperationAborted) return;  StartAccept(e);  }  void IO_Completed(object sender, SocketAsyncEventArgs e)  {  // determine which type of operation just completed and call the associated handler  switch (e.LastOperation)  {  case SocketAsyncOperation.Receive:  ProcessReceive(e);  break;  case SocketAsyncOperation.Send:  ProcessSend(e);  break;  default:  throw new ArgumentException("The last operation completed on the socket was not a receive or send");  }  }  // 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.  //  private void ProcessReceive(SocketAsyncEventArgs e)  {  try  {  // check if the remote host closed the connection  AsyncUserToken token = (AsyncUserToken)e.UserToken;  if (e.BytesTransferred > 0 && e.SocketError == SocketError.Success)  {  //读取数据  byte[] data = new byte[e.BytesTransferred];  Array.Copy(e.Buffer, e.Offset, data, 0, e.BytesTransferred);  lock (token.Buffer)  {  token.Buffer.AddRange(data);  }  //注意:你一定会问,这里为什么要用do-while循环?   //如果当客户发送大数据流的时候,e.BytesTransferred的大小就会比客户端发送过来的要小,  //需要分多次接收.所以收到包的时候,先判断包头的大小.够一个完整的包再处理.  //如果客户短时间内发送多个小数据包时, 服务器可能会一次性把他们全收了.  //这样如果没有一个循环来控制,那么只会处理第一个包,  //剩下的包全部留在token.Buffer中了,只有等下一个数据包过来后,才会放出一个来.  do  {  //判断包的长度  byte[] lenBytes = token.Buffer.GetRange(0, 4).ToArray();  int packageLen = BitConverter.ToInt32(lenBytes, 0);  if (packageLen > token.Buffer.Count - 4)  {   //长度不够时,退出循环,让程序继续接收  break;  }  //包够长时,则提取出来,交给后面的程序去处理  byte[] rev = token.Buffer.GetRange(4, packageLen).ToArray();  //从数据池中移除这组数据  lock (token.Buffer)  {  token.Buffer.RemoveRange(0, packageLen + 4);  }  //将数据包交给后台处理,这里你也可以新开个线程来处理.加快速度.  if(ReceiveClientData != null)  ReceiveClientData(token, rev);  //这里API处理完后,并没有返回结果,当然结果是要返回的,却不是在这里, 这里的代码只管接收.  //若要返回结果,可在API处理中调用此类对象的SendMessage方法,统一打包发送.不要被微软的示例给迷惑了.  } while (token.Buffer.Count > 4);  //继续接收. 为什么要这么写,请看Socket.ReceiveAsync方法的说明  if (!token.Socket.ReceiveAsync(e))  this.ProcessReceive(e);  }  else  {  CloseClientSocket(e);  }  }  catch (Exception xe)  {  RuncomLib.Log.LogUtils.Info(xe.Message + "\r\n" + xe.StackTrace);  }  }  // 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  //  // <param name="e"></param>  private void ProcessSend(SocketAsyncEventArgs e)  {  if (e.SocketError == SocketError.Success)  {  // done echoing data back to the client  AsyncUserToken token = (AsyncUserToken)e.UserToken;  // read the next block of data send from the client  bool willRaiseEvent = token.Socket.ReceiveAsync(e);  if (!willRaiseEvent)  {  ProcessReceive(e);  }  }  else  {  CloseClientSocket(e);  }  }  //关闭客户端  private void CloseClientSocket(SocketAsyncEventArgs e)  {  AsyncUserToken token = e.UserToken as AsyncUserToken;  lock (m_clients) { m_clients.Remove(token); }  //如果有事件,则调用事件,发送客户端数量变化通知  if (ClientNumberChange != null)  ClientNumberChange(-1, token);  // close the socket associated with the client  try  {  token.Socket.Shutdown(SocketShutdown.Send);  }  catch (Exception) { }  token.Socket.Close();  // decrement the counter keeping track of the total number of clients connected to the server  Interlocked.Decrement(ref m_clientCount);  m_maxNumberAcceptedClients.Release();  // Free the SocketAsyncEventArg so they can be reused by another client  e.UserToken = new AsyncUserToken();  m_pool.Push(e);  }  /// <summary>  /// 对数据进行打包,然后再发送  /// </summary>  /// <param name="token"></param>  /// <param name="message"></param>  /// <returns></returns>  public void SendMessage(AsyncUserToken token, byte[] message)  {  if (token == null || token.Socket == null || !token.Socket.Connected)  return;  try  {  //对要发送的消息,制定简单协议,头4字节指定包的大小,方便客户端接收(协议可以自己定)  byte[] buff = new byte[message.Length + 4];  byte[] len = BitConverter.GetBytes(message.Length);  Array.Copy(len, buff, 4);  Array.Copy(message, 0, buff, 4, message.Length);  //token.Socket.Send(buff);  //这句也可以发送, 可根据自己的需要来选择  //新建异步发送对象, 发送消息  SocketAsyncEventArgs sendArg = new SocketAsyncEventArgs();  sendArg.UserToken = token;  sendArg.SetBuffer(buff, 0, buff.Length);  //将数据放置进去.  token.Socket.SendAsync(sendArg);  }  catch (Exception e){  RuncomLib.Log.LogUtils.Info("SendMessage - Error:" + e.Message);  }  }  }  
}

使用方法：

SocketManager m_socket = new SocketManager(200, 1024);

m_socket.Init();

m_socket.Start(new IPEndPoint(IPAddress.Any, 13909));

//m_socket.Stop();