How to listen on a socket for only 10 seconds

amy

Hi,

I read the following code which open a server socket for client request.
However,  i would like to know how can I change it so that i just listen for client requestfor 10 seconds, after that, it bows out?
Code-- Create socket for listening for client connection requests. listenSocket = socket(AF_INET, SOCK_STREAM, 0); if (listenSocket lt; 0) {   std::cout lt;lt; quot;cannot create listen socketquot;;   return; }  // Bind listen socket to listen port.  First set various fields in // the serverAddress structure, then call bind(). // htonl() and htons() convert long integers and short integers // (respectively) from host byte order (on x86 this is Least // Significant Byte first) to network byte order (Most Significant // Byte first). serverAddress.sin_family = AF_INET; serverAddress.sin_addr.s_addr = htonl(INADDR_ANY); serverAddress.sin_port = htons(listenPort);  if (bind(listenSocket,          (struct sockaddr *) amp;serverAddress,          sizeof(serverAddress)) lt; 0) {   std::cout lt;lt; quot;cannot bind socketquot;;   return; }
// Wait for connections from clients. // This is a non-blocking call; i.e., it registers this program with // the system as expecting connections on this socket, and then // this thread of execution continues on. listen(listenSocket, 10);      int count = 0;
   while (1) {   std::cout lt;lt; quot;Waiting for TCP connection on port quot; lt;lt; listenPort lt;lt; quot; ...\nquot;;
   // Accept a connection with a client that is requesting one.  The   // accept() call is a blocking call; i.e., this thread of   // execution stops until a connection comes in.   // connectSocket is a new socket that the system provides,   // separate from listenSocket.  We *could* accept more   // connections on listenSocket, before connectSocket is closed,   // but this program doesn't do that.   clientAddressLength = sizeof(clientAddress);   connectSocket = accept(listenSocket,               (struct sockaddr *) amp;clientAddress,               amp;clientAddressLength);   if (connectSocket lt; 0) {     std::cout lt;lt; quot;cannot accept connection quot;;     return;   }
Thank you.

you'd have to implement a 'clock' in the software.  Instead of while(1) do a time check to make sure that the loop stops once 10 seconds have been reached.

You can include time.h, and do the following:

Code: clock_t finish; finish = clock() + 10*CLOCKS_PER_SEC; while (clock() lt; finish);


Look up select() in the man pages.  The select() function lets your program wait for an event (such as a connection request) on one or more file descriptors (sockets in your case).  There is a timeout parameter that you can use to achieve your 10 second timeout as well.

The advantage of using select over a while loop with a non-blocking listen call is that your program will sleep for the 10 seconds (or until a connection request is received on the socket) rather than looping and consuming CPU cycles.

Select is also handy for handling multiple connections in a single thread.  Say if you have a daemon listening on a socket, and multiple clients connect to the socket, select() will return which socket(s) have pending actions on them so your program can act on them.