最近有项目要做一个高性能网络服务器,决定下功夫搞定完成端口(IOCP),最终花了一个星期终于把它弄清楚了,并用C++写了一个版本,效率很不错。
但,从项目的总体需求来考虑,最终决定上.net平台,因此又花了一天一夜弄出了一个C#版,在这与大家分享。
一些心得体会:
1、在C#中,不用去面对完成端口的操作系统内核对象,Microsoft已经为我们提供了SocketAsyncEventArgs类,它封装了IOCP的使用。请参考:http://msdn.microsoft.com/zh-cn/library/system.net.sockets.socketasynceventargs.aspx?cs-save-lang=1&cs-lang=cpp#code-snippet-1。
2、我的SocketAsyncEventArgsPool类使用List对象来存储对客户端来通信的SocketAsyncEventArgs对象,它相当于直接使用内核对象时的IoContext。我这样设计比用堆栈来实现的好处理是,我可以在SocketAsyncEventArgsPool池中找到任何一个与服务器连接的客户,主动向它发信息。而用堆栈来实现的话,要主动给客户发信息,则还要设计一个结构来存储已连接上服务器的客户。
3、对每一个客户端不管还发送还是接收,我使用同一个SocketAsyncEventArgs对象,对每一个客户端来说,通信是同步进行的,也就是说服务器高度保证同一个客户连接上要么在投递发送请求,并等待;或者是在投递接收请求,等待中。本例只做echo服务器,还未考虑由服务器主动向客户发送信息。
4、SocketAsyncEventArgs的UserToken被直接设定为被接受的客户端Socket。
5、没有使用BufferManager 类,因为我在初始化时给每一个SocketAsyncEventArgsPool中的对象分配一个缓冲区,发送时使用Arrary.Copy来进行字符拷贝,不去改变缓冲区的位置,只改变使用的长度,因此在下次投递接收请求时恢复缓冲区长度就可以了!如果要主动给客户发信息的话,可以new一个SocketAsyncEventArgs对象,或者在初始化中建立几个来专门用于主动发送信息,因为这种需求一般是进行信息群发,建立一个对象可以用于很多次信息发送,总体来看,这种花销不大,还减去了字符拷贝和消耗。
6、测试结果:(在我的笔记本上时行的,我的本本是T420 I7 8G内存)
100客户 100,000(十万次)不间断的发送接收数据(发送和接收之间没有Sleep,就一个一循环,不断的发送与接收)
耗时3004.6325 秒完成
总共 10,000,000 一千万次访问
平均每分完成 199,691.6 次发送与接收
平均每秒完成 3,328.2 次发送与接收
整个运行过程中,内存消耗在开始两三分种后就保持稳定不再增涨。
看了一下对每个客户端的延迟最多不超过2毫秒,CPU占用在8%左右。
7、下载地址:http://download.csdn.net/detail/ztk12/4928644
8、源码:
1 using System; 2 using System.Collections.Generic; 3 using System.Text; 4 using System.Net.Sockets; 5 6 namespace IocpServer 7 { 8 /// <summary> 9 /// 与每个客户Socket相关联,进行Send和Receive投递时所需要的参数 10 /// </summary> 11 internal sealed class IoContextPool 12 { 13 List<SocketAsyncEventArgs> pool; //为每一个Socket客户端分配一个SocketAsyncEventArgs,用一个List管理,在程序启动时建立。 14 Int32 capacity; //pool对象池的容量 15 Int32 boundary; //已分配和未分配对象的边界,大的是已经分配的,小的是未分配的 16 17 internal IoContextPool(Int32 capacity) 18 { 19 this.pool = new List<SocketAsyncEventArgs>(capacity); 20 this.boundary = 0; 21 this.capacity = capacity; 22 } 23 24 /// <summary> 25 /// 往pool对象池中增加新建立的对象,因为这个程序在启动时会建立好所有对象, 26 /// 故这个方法只在初始化时会被调用,因此,没有加锁。 27 /// </summary> 28 /// <param name="arg"></param> 29 /// <returns></returns> 30 internal bool Add(SocketAsyncEventArgs arg) 31 { 32 if (arg != null && pool.Count < capacity) 33 { 34 pool.Add(arg); 35 boundary++; 36 return true; 37 } 38 else 39 return false; 40 } 41 42 /// <summary> 43 /// 取出集合中指定对象,内部使用 44 /// </summary> 45 /// <param name="index"></param> 46 /// <returns></returns> 47 //internal SocketAsyncEventArgs Get(int index) 48 //{ 49 // if (index >= 0 && index < capacity) 50 // return pool[index]; 51 // else 52 // return null; 53 //} 54 55 /// <summary> 56 /// 从对象池中取出一个对象,交给一个socket来进行投递请求操作 57 /// </summary> 58 /// <returns></returns> 59 internal SocketAsyncEventArgs Pop() 60 { 61 lock (this.pool) 62 { 63 if (boundary > 0) 64 { 65 --boundary; 66 return pool[boundary]; 67 } 68 else 69 return null; 70 } 71 } 72 73 /// <summary> 74 /// 一个socket客户断开,与其相关的IoContext被释放,重新投入Pool中,备用。 75 /// </summary> 76 /// <param name="arg"></param> 77 /// <returns></returns> 78 internal bool Push(SocketAsyncEventArgs arg) 79 { 80 if (arg != null) 81 { 82 lock (this.pool) 83 { 84 int index = this.pool.IndexOf(arg, boundary); //找出被断开的客户,此处一定能查到,因此index不可能为-1,必定要大于0。 85 if (index == boundary) //正好是边界元素 86 boundary++; 87 else 88 { 89 this.pool[index] = this.pool[boundary]; //将断开客户移到边界上,边界右移 90 this.pool[boundary++] = arg; 91 } 92 } 93 return true; 94 } 95 else 96 return false; 97 } 98 } 99 }
1 using System;
2 using System.Collections.Generic;
3 using System.Text;
4 using System.Net.Sockets;
5 using System.Threading;
6 using System.Net;
7
8 namespace IocpServer
9 {
10 /// <summary>
11 /// 基于SocketAsyncEventArgs 实现 IOCP 服务器
12 /// </summary>
13 internal sealed class IoServer
14 {
15 /// <summary>
16 /// 监听Socket,用于接受客户端的连接请求
17 /// </summary>
18 private Socket listenSocket;
19
20 /// <summary>
21 /// 用于服务器执行的互斥同步对象
22 /// </summary>
23 private static Mutex mutex = new Mutex();
24
25 /// <summary>
26 /// 用于每个I/O Socket操作的缓冲区大小
27 /// </summary>
28 private Int32 bufferSize;
29
30 /// <summary>
31 /// 服务器上连接的客户端总数
32 /// </summary>
33 private Int32 numConnectedSockets;
34
35 /// <summary>
36 /// 服务器能接受的最大连接数量
37 /// </summary>
38 private Int32 numConnections;
39
40 /// <summary>
41 /// 完成端口上进行投递所用的IoContext对象池
42 /// </summary>
43 private IoContextPool ioContextPool;
44
45 public MainForm mainForm;
46
47 /// <summary>
48 /// 构造函数,建立一个未初始化的服务器实例
49 /// </summary>
50 /// <param name="numConnections">服务器的最大连接数据</param>
51 /// <param name="bufferSize"></param>
52 internal IoServer(Int32 numConnections, Int32 bufferSize)
53 {
54 this.numConnectedSockets = 0;
55 this.numConnections = numConnections;
56 this.bufferSize = bufferSize;
57
58 this.ioContextPool = new IoContextPool(numConnections);
59
60 // 为IoContextPool预分配SocketAsyncEventArgs对象
61 for (Int32 i = 0; i < this.numConnections; i++)
62 {
63 SocketAsyncEventArgs ioContext = new SocketAsyncEventArgs();
64 ioContext.Completed += new EventHandler<SocketAsyncEventArgs>(OnIOCompleted);
65 ioContext.SetBuffer(new Byte[this.bufferSize], 0, this.bufferSize);
66
67 // 将预分配的对象加入SocketAsyncEventArgs对象池中
68 this.ioContextPool.Add(ioContext);
69 }
70 }
71
72 /// <summary>
73 /// 当Socket上的发送或接收请求被完成时,调用此函数
74 /// </summary>
75 /// <param name="sender">激发事件的对象</param>
76 /// <param name="e">与发送或接收完成操作相关联的SocketAsyncEventArg对象</param>
77 private void OnIOCompleted(object sender, SocketAsyncEventArgs e)
78 {
79 // Determine which type of operation just completed and call the associated handler.
80 switch (e.LastOperation)
81 {
82 case SocketAsyncOperation.Receive:
83 this.ProcessReceive(e);
84 break;
85 case SocketAsyncOperation.Send:
86 this.ProcessSend(e);
87 break;
88 default:
89 throw new ArgumentException("The last operation completed on the socket was not a receive or send");
90 }
91 }
92
93 /// <summary>
94 ///接收完成时处理函数
95 /// </summary>
96 /// <param name="e">与接收完成操作相关联的SocketAsyncEventArg对象</param>
97 private void ProcessReceive(SocketAsyncEventArgs e)
98 {
99 // 检查远程主机是否关闭连接
100 if (e.BytesTransferred > 0)
101 {
102 if (e.SocketError == SocketError.Success)
103 {
104 Socket s = (Socket)e.UserToken;
105 //判断所有需接收的数据是否已经完成
106 if (s.Available == 0)
107 {
108 // 设置发送数据
109 Array.Copy(e.Buffer, 0, e.Buffer, e.BytesTransferred, e.BytesTransferred);
110 e.SetBuffer(e.Offset, e.BytesTransferred * 2);
111 if (!s.SendAsync(e)) //投递发送请求,这个函数有可能同步发送出去,这时返回false,并且不会引发SocketAsyncEventArgs.Completed事件
112 {
113 // 同步发送时处理发送完成事件
114 this.ProcessSend(e);
115 }
116 }
117 else if (!s.ReceiveAsync(e)) //为接收下一段数据,投递接收请求,这个函数有可能同步完成,这时返回false,并且不会引发SocketAsyncEventArgs.Completed事件
118 {
119 // 同步接收时处理接收完成事件
120 this.ProcessReceive(e);
121 }
122 }
123 else
124 {
125 this.ProcessError(e);
126 }
127 }
128 else
129 {
130 this.CloseClientSocket(e);
131 }
132 }
133
134 /// <summary>
135 /// 发送完成时处理函数
136 /// </summary>
137 /// <param name="e">与发送完成操作相关联的SocketAsyncEventArg对象</param>
138 private void ProcessSend(SocketAsyncEventArgs e)
139 {
140 if (e.SocketError == SocketError.Success)
141 {
142 Socket s = (Socket)e.UserToken;
143
144 //接收时根据接收的字节数收缩了缓冲区的大小,因此投递接收请求时,恢复缓冲区大小
145 e.SetBuffer(0, bufferSize);
146 if (!s.ReceiveAsync(e)) //投递接收请求
147 {
148 // 同步接收时处理接收完成事件
149 this.ProcessReceive(e);
150 }
151 }
152 else
153 {
154 this.ProcessError(e);
155 }
156 }
157
158 /// <summary>
159 /// 处理socket错误
160 /// </summary>
161 /// <param name="e"></param>
162 private void ProcessError(SocketAsyncEventArgs e)
163 {
164 Socket s = e.UserToken as Socket;
165 IPEndPoint localEp = s.LocalEndPoint as IPEndPoint;
166
167 this.CloseClientSocket(s, e);
168
169 string outStr = String.Format("套接字错误 {0}, IP {1}, 操作 {2}。", (Int32)e.SocketError, localEp, e.LastOperation);
170 mainForm.Invoke(mainForm.setlistboxcallback, outStr);
171 //Console.WriteLine("Socket error {0} on endpoint {1} during {2}.", (Int32)e.SocketError, localEp, e.LastOperation);
172 }
173
174 /// <summary>
175 /// 关闭socket连接
176 /// </summary>
177 /// <param name="e">SocketAsyncEventArg associated with the completed send/receive operation.</param>
178 private void CloseClientSocket(SocketAsyncEventArgs e)
179 {
180 Socket s = e.UserToken as Socket;
181 this.CloseClientSocket(s, e);
182 }
183
184 private void CloseClientSocket(Socket s, SocketAsyncEventArgs e)
185 {
186 Interlocked.Decrement(ref this.numConnectedSockets);
187
188 // SocketAsyncEventArg 对象被释放,压入可重用队列。
189 this.ioContextPool.Push(e);
190 string outStr = String.Format("客户 {0} 断开, 共有 {1} 个连接。", s.RemoteEndPoint.ToString(), this.numConnectedSockets);
191 mainForm.Invoke(mainForm.setlistboxcallback, outStr);
192 //Console.WriteLine("A client has been disconnected from the server. There are {0} clients connected to the server", this.numConnectedSockets);
193 try
194 {
195 s.Shutdown(SocketShutdown.Send);
196 }
197 catch (Exception)
198 {
199 // Throw if client has closed, so it is not necessary to catch.
200 }
201 finally
202 {
203 s.Close();
204 }
205 }
206
207 /// <summary>
208 /// accept 操作完成时回调函数
209 /// </summary>
210 /// <param name="sender">Object who raised the event.</param>
211 /// <param name="e">SocketAsyncEventArg associated with the completed accept operation.</param>
212 private void OnAcceptCompleted(object sender, SocketAsyncEventArgs e)
213 {
214 this.ProcessAccept(e);
215 }
216
217 /// <summary>
218 /// 监听Socket接受处理
219 /// </summary>
220 /// <param name="e">SocketAsyncEventArg associated with the completed accept operation.</param>
221 private void ProcessAccept(SocketAsyncEventArgs e)
222 {
223 Socket s = e.AcceptSocket;
224 if (s.Connected)
225 {
226 try
227 {
228 SocketAsyncEventArgs ioContext = this.ioContextPool.Pop();
229 if (ioContext != null)
230 {
231 // 从接受的客户端连接中取数据配置ioContext
232
233 ioContext.UserToken = s;
234
235 Interlocked.Increment(ref this.numConnectedSockets);
236 string outStr = String.Format("客户 {0} 连入, 共有 {1} 个连接。", s.RemoteEndPoint.ToString(),this.numConnectedSockets);
237 mainForm.Invoke(mainForm.setlistboxcallback,outStr);
238 //Console.WriteLine("Client connection accepted. There are {0} clients connected to the server",
239 //this.numConnectedSockets);
240
241 if (!s.ReceiveAsync(ioContext))
242 {
243 this.ProcessReceive(ioContext);
244 }
245 }
246 else //已经达到最大客户连接数量,在这接受连接,发送“连接已经达到最大数”,然后断开连接
247 {
248 s.Send(Encoding.Default.GetBytes("连接已经达到最大数!"));
249 string outStr = String.Format("连接已满,拒绝 {0} 的连接。", s.RemoteEndPoint);
250 mainForm.Invoke(mainForm.setlistboxcallback, outStr);
251 s.Close();
252 }
253 }
254 catch (SocketException ex)
255 {
256 Socket token = e.UserToken as Socket;
257 string outStr = String.Format("接收客户 {0} 数据出错, 异常信息: {1} 。", token.RemoteEndPoint, ex.ToString());
258 mainForm.Invoke(mainForm.setlistboxcallback, outStr);
259 //Console.WriteLine("Error when processing data received from {0}:\r\n{1}", token.RemoteEndPoint, ex.ToString());
260 }
261 catch (Exception ex)
262 {
263 mainForm.Invoke(mainForm.setlistboxcallback, "异常:" + ex.ToString());
264 }
265 // 投递下一个接受请求
266 this.StartAccept(e);
267 }
268 }
269
270 /// <summary>
271 /// 从客户端开始接受一个连接操作
272 /// </summary>
273 /// <param name="acceptEventArg">The context object to use when issuing
274 /// the accept operation on the server's listening socket.</param>
275 private void StartAccept(SocketAsyncEventArgs acceptEventArg)
276 {
277 if (acceptEventArg == null)
278 {
279 acceptEventArg = new SocketAsyncEventArgs();
280 acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(OnAcceptCompleted);
281 }
282 else
283 {
284 // 重用前进行对象清理
285 acceptEventArg.AcceptSocket = null;
286 }
287
288 if (!this.listenSocket.AcceptAsync(acceptEventArg))
289 {
290 this.ProcessAccept(acceptEventArg);
291 }
292 }
293
294 /// <summary>
295 /// 启动服务,开始监听
296 /// </summary>
297 /// <param name="port">Port where the server will listen for connection requests.</param>
298 internal void Start(Int32 port)
299 {
300 // 获得主机相关信息
301 IPAddress[] addressList = Dns.GetHostEntry(Environment.MachineName).AddressList;
302 IPEndPoint localEndPoint = new IPEndPoint(addressList[addressList.Length - 1], port);
303
304 // 创建监听socket
305 this.listenSocket = new Socket(localEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
306 this.listenSocket.ReceiveBufferSize = this.bufferSize;
307 this.listenSocket.SendBufferSize = this.bufferSize;
308
309 if (localEndPoint.AddressFamily == AddressFamily.InterNetworkV6)
310 {
311 // 配置监听socket为 dual-mode (IPv4 & IPv6)
312 // 27 is equivalent to IPV6_V6ONLY socket option in the winsock snippet below,
31