C # Use the select method to implement the socket server,

C # Use the select method to implement the socket server,

Select is an old but proven socket mode that allows you to write socket programs in message-driven mode. There are many examples of C ++ on the Internet, but there are very few examples of C.

Code:

Namespace Server {class Program {// Thread signal. public static ManualResetEvent allDone = new ManualResetEvent (false); private static Socket handler = null; private static ArrayList g_CliSocketArr = new ArrayList (); private static Object thisLock = new Object (); public Program () {} public static void StartListening () {// Data buffer for incoming data. byte [] bytes = new Byte [1024]; IPAddress ipAddress = IPAddress. parse ("192.168.1.71"); // IPEndPoint localEndPoint = new IPEndPoint (ipAddress, 11000); // Create a TCP/IP socket. socket listener = new Socket (AddressFamily. interNetwork, SocketType. stream, ProtocolType. tcp); // Bind the socket to the local endpoint and listen for incoming connections. try {listener. bind (localEndPoint); listener. listen (100); // Start an asynchronous socket to listen for connections. console. writeLine ("Waiting for a connection... "); Thread worker = new Thread (new ThreadStart (WorkerThread); // create a Thread to process the worker request. start (); while (true) {Socket sClient = listener. accept (); Console. writeLine ("There is a new connection. "); g_CliSocketArr.Add (sClient) ;}} catch (Exception e) {Console. writeLine (e. toString ();} Console. writeLine ("\ nPress ENTER to continue... "); Console. read ();} public static void WorkerThread () {Socket socket1 = null; ArrayList readList = new ArrayList (); // readList. add (socket0); while (true) {lock (thisLock) {readList. clear (); for (int I = 0; I <g_CliSocketArr.Count; I ++) {readList. add (g_CliSocketArr [I]) ;}} if (readList. count <= 0) {Thread. sleep (100); continue;} try {Socket. select (read list, null, null, 500); for (int I = 0; I <readList. count; I ++) {socket1 = (Socket) readList [I]; Console. writeLine ("There is a new message from client. "); byte [] buffer = new byte [1024]; int recLen = socket1.Receive (buffer); if (recLen> 0) {// recLen = socket1.Receive (buffer );} else {// If 0 is returned, the client has been disconnected. You must disable this socket and then clear the Console from the connection pool. writeLine ("Rece 0 length. "); for (int ii = 0; ii <g_CliSocketArr.Count; ii ++) {Socket s = (Socket) g_CliSocketArr [ii]; if (s = socket1) g_CliSocketArr.RemoveAt (ii);} socket1.Shutdown (SocketShutdown. both); socket1.Close (); break;} socket1.Send (buffer, recLen, SocketFlags. none) ;}} catch (SocketException e) {Console. writeLine ("{0} Error code: {1 }. ", e. message, e. errorCode); for (int ii = 0; ii <g_CliSocketArr.Count; ii ++) {Socket s = (Socket) g_CliSocketArr [ii]; if (s = socket1) g_CliSocketArr.RemoveAt (ii);} socket1.Shutdown (SocketShutdown. both); socket1.Close () ;}} static void Main (string [] args) {StartListening ();}}}

C language ^ how to use

A1 = 0x01; // 0000 0001
A2 = 0x00; // 0000 0000
A3 = 0x03; // 0000 0011
A4 = 0x02; // 0000 0010

B1 = a1 ^ a2; // 0000 0001
B2 = a1 ^ a3; // 0000 0010
B3 = a1 ^ a4; // 0000 0011

^ XOR operator. The bitwise value is 0 and the difference is 1. See the example above.

//
Examples of simple and practical problems:
====================================
======= A ======= B =========
There are two circuits on the top. The two switches are a and B respectively. The opening status is \ [1], and the closing status is/[0].
If both circuits are enabled or disabled.
If a turns on [1], B turns off [0], and circuit 1 Powers on
=====================
If a disables [0], B enables [1], and circuit 2 powers on.
====================================
In summary, the circuit fails in the and B states simultaneously [0]. When a and B are different, the power is charged [1].

C language ^ how to use

A1 = 0x01; // 0000 0001
A2 = 0x00; // 0000 0000
A3 = 0x03; // 0000 0011
A4 = 0x02; // 0000 0010

B1 = a1 ^ a2; // 0000 0001
B2 = a1 ^ a3; // 0000 0010
B3 = a1 ^ a4; // 0000 0011

^ XOR operator. The bitwise value is 0 and the difference is 1. See the example above.

//
Examples of simple and practical problems:
====================================
======= A ======= B =========
There are two circuits on the top. The two switches are a and B respectively. The opening status is \ [1], and the closing status is/[0].
If both circuits are enabled or disabled.
If a turns on [1], B turns off [0], and circuit 1 Powers on
=====================
If a disables [0], B enables [1], and circuit 2 powers on.
====================================
In summary, the circuit fails in the and B states simultaneously [0]. When a and B are different, the power is charged [1].