Socket中如何设置连接超时

1. create socket

     struct sockaddr_in addr;
     addr.sin_family = AF_INET;

     // Server address
     addr.sin_addr.s_addr = inet_addr(host);
     // Server port
     addr.sin_port = htons(port);

     // Creating socket
     if ((soc = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET)
      throw connector_exception("connector: can't create socket");

    2. connect

     if (::connect(soc, (struct sockaddr *) &addr, sizeof(addr)) == SOCKET_ERROR)
      throw connector_exception("connector: can't connect.");

    3. 设置为非阻塞式socket

       unsigned long ul = 1;
       int ret = ioctlsocket(rec(), FIONBIO, (unsigned long*)&ul);
       if(ret==SOCKET_ERROR)
        log <<"ioctlsocket error" << endl;
    4. select socket

       FD_SET(rec(), &r_readfds); FD_SET(rec(), &r_exfds);
      if ((iret=select(0,&r_readfds, NULL,&r_exfds,&tv))==SOCKET_ERROR){
    每次调用好select后，select 函数自动把r_readfds，r_exfds都设为空，必须重新调用
    FD_SET(rec(), &r_readfds); FD_SET(rec(), &r_exfds);  否则会报10022 WSAEINVAL 错误

    5 参考文献

    http://support.microsoft.com/kb/q147714/