static int makeNonBlocking(int sockfd)
{
#ifdef WIN32
    ULONG ioctl_opt = 1;
    return ioctlsocket(sockfd, FIONBIO, &ioctl_opt);
#else
    int result = fcntl(sockfd, F_SETFL, O_NONBLOCK);
    return result >= 0 ? result : SOCKET_ERROR;
#endif
}
Unknown