寫自己的Socket框架(一)

本系列僅介紹可用于生產環境的C#異步Socket框架，如果您在其他地方看到類似的代碼，不要驚訝，那可能就是我在參考開源代碼時，直接“剽竊”過來的。

1、在腦海里思考一下整個socket的鏈接的處理流程，于是便有了下圖。

2、首先就開始監聽，代碼如下：

public override bool Start()        {            this._socket = new System.Net.Sockets.Socket(AddressFamily.InterNetwork, SocketType.Stream, PRotocolType.Tcp);            //設置KeeyAlive，如果客戶端不主動發消息時，Tcp本身會發一個心跳包，來通知服務器，這是一個保持通訊的鏈接。            //避免等到下一次通訊時，才知道鏈接已經斷開。            this._socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);            this._socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, true);            try            {                this._socket.Bind(base.SocketConfig.Point);                this._socket.Listen(base.SocketConfig.Backlog);                this._socket_args = new SocketAsyncEventArgs();                this._socket_args.Completed += new EventHandler<SocketAsyncEventArgs>(AcceptSocketCompleted);                //在鏈接過來的時候，如果IO沒有掛起，則AcceptAsync為False，表明同步完成。                if (!this._socket.AcceptAsync(this._socket_args))                {                    AcceptSocketCompleted(this._socket, this._socket_args);                }                return true;            }            catch (Exception ex)            {                return false;            }        }void AcceptSocketCompleted(object sender, SocketAsyncEventArgs e)        {            System.Net.Sockets.Socket socket = null;            if (e.SocketError != SocketError.Success)            {                    return;            }            else            {                socket = e.AcceptSocket;            }            e.AcceptSocket = null;            bool willRaiseEvent = false;            try            {                //繼續監聽該端口，在處理邏輯時，不影響其他鏈接的數據傳送。                willRaiseEvent = this._socket.AcceptAsync(e);            }            catch (Exception ex)            {                willRaiseEvent = true;            }            if (socket != null)                OnNewClientAccepted(socket, null);            if (!willRaiseEvent)                AcceptSocketCompleted(null, e);        }

3、這個時候鏈接過來了，就要開始入隊列了，如果沒有這方面的需求，這一步可以忽略，代碼如下：

public class SocketProxy    {        public System.Net.Sockets.Socket Client;        public DateTime Timeout = DateTime.Now;    }public class SocketConnectionQueue : IDisposable    {        private Queue<SocketProxy> _queue;        private readonly object _syncObject = new object();        private bool _isStop = false;        private Thread _thread;        public Action<SocketProxy> Connected;        public SocketConnectionQueue()        {            if (_queue == null)            {                _queue = new Queue<SocketProxy>();            }            if (_thread == null)            {                _thread = new Thread(Thread_Work)                {                    IsBackground = true,                    Priority = ThreadPriority.Highest                };                _thread.Start();            }        }        public void Push(SocketProxy connect)        {            lock (_syncObject)            {                if (_queue != null)                {                    _queue.Enqueue(connect);                }            }        }        public void Thread_Work()        {            while (!_isStop)            {                SocketProxy[] socketConnect = null;                lock (_syncObject)                {                    if (_queue.Count > 0)                    {                        socketConnect = new SocketProxy[_queue.Count];                        _queue.CopyTo(socketConnect, 0);                        _queue.Clear();                    }                }                if (socketConnect != null && socketConnect.Length > 0)                {                    foreach (var client in socketConnect)                    {                        if (Connected != null)                        {                            Connected.Invoke(client);                        }                    }                }                Thread.Sleep(10);            }        }        public void Dispose()        {            _isStop = true;            if (_thread != null)            {                _thread.Join();            }        }    }

4、入完隊列，就要開始從鏈接池子里面分配資源了，你也可以不做鏈接池，在每次請求過來的時候去實例化一個鏈接，然后將這個鏈接入池，我的做法是在程序初始化的時候就分配好一定的資源，代碼如下：

public class SocketConnectionPool : IDisposable    {        private ServerConfig _serverConfig;        public IAppServer AppServer;        private ConcurrentStack<SocketConnection> _connectPool;        private long connect_id = 0;        private byte[] _buffer;        private readonly object _syncObject = new object();        private SocketConnectionQueue _queue;        public Action<System.Net.Sockets.Socket, SocketConnection> Connected;        public long GenerateId()        {            if (connect_id == long.MaxValue)            {                connect_id = 0;            }            connect_id++;            return connect_id;        }        public SocketConnectionPool(IAppServer server)        {            this.AppServer = server;            this._serverConfig = server.AppConfig;        }        public void Init()        {            var connects = new List<SocketConnection>(this._serverConfig.MaxConnectionNumber);            _buffer = new byte[this._serverConfig.BufferSize];            SocketAsyncEventArgs arg;            for (var i = 0; i < this._serverConfig.MaxConnectionNumber; i++)            {                arg = new SocketAsyncEventArgs();                arg.SetBuffer(_buffer, 0, _buffer.Length);                connects.Add(new SocketConnection(arg, this));            }            _connectPool = new ConcurrentStack<SocketConnection>(connects);            if (_queue == null)            {                _queue = new SocketConnectionQueue();            }                        _queue.Connected = OnConnected;        }        public void Push(System.Net.Sockets.Socket socket)        {            SocketProxy proxy = new SocketProxy()            {                Client = socket            };            _queue.Push(proxy);        }        public void OnConnected(SocketProxy proxy)        {            //如果發現隊列里面的鏈接，在Timeout時間內，都沒有分配到資源，則關掉鏈接并丟棄。            int timeout = (int)(DateTime.Now - proxy.Timeout).TotalSeconds;            if (timeout >= this._serverConfig.Timeout)            {                proxy.Client.Close();                return;            }            else            {                //沒有分配到資源重新入列。                SocketConnection connect = this.GetConnectionFromPool();                if (connect == null)                {                    _queue.Push(proxy);                }                else                {                    if