accept_nonblock

/*
 * call-seq:
 *      unixserver.accept_nonblock => unixsocket
 * 
 * Accepts an incoming connection using accept(2) after
 * O_NONBLOCK is set for the underlying file descriptor.
 * It returns an accepted UNIXSocket for the incoming connection.
 * 
 * === Example
 *      require 'socket'
 *      serv = UNIXServer.new("/tmp/sock")
 *      begin
 *        sock = serv.accept_nonblock
 *      rescue Errno::EAGAIN, Errno::EWOULDBLOCK, Errno::ECONNABORTED, Errno::EPROTO, Errno::EINTR
 *        IO.select([serv])
 *        retry
 *      end
 *      # sock is an accepted socket.
 * 
 * Refer to Socket#accept for the exceptions that may be thrown if the call
 * to UNIXServer#accept_nonblock fails. 
 *
 * UNIXServer#accept_nonblock may raise any error corresponding to accept(2) failure,
 * including Errno::EAGAIN.
 * 
 * === See
 * * UNIXServer#accept
 * * Socket#accept
 */
static VALUE
unix_accept_nonblock(sock)
    VALUE sock;
{
    rb_io_t *fptr;
    struct sockaddr_un from;
    socklen_t fromlen;

    GetOpenFile(sock, fptr);
    fromlen = sizeof(from);
    return s_accept_nonblock(rb_cUNIXSocket, fptr,
                             (struct sockaddr *)&from, &fromlen);
}