/* Copyright 1998 by the Massachusetts Institute of Technology.

 *

 * Permission to use, copy, modify, and distribute this

 * software and its documentation for any purpose and without

 * fee is hereby granted, provided that the above copyright

 * notice appear in all copies and that both that copyright

 * notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in

 * advertising or publicity pertaining to distribution of the

 * software without specific, written prior permission.

 * M.I.T. makes no representations about the suitability of

 * this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include "ares_setup.h"

#include "ares.h"

#include "ares_nowarn.h"

#include "ares_private.h"

int ares_fds(ares_channel channel, fd_set *read_fds, fd_set *write_fds)

{

  struct server_state *server;

  ares_socket_t nfds;

  int i;

  /* Are there any active queries? */

  int active_queries = !ares__is_list_empty(&(channel->all_queries));

  nfds = 0;

  for (i = 0; i < channel->nservers; i++)

    {

      server = &channel->servers[i];

      /* We only need to register interest in UDP sockets if we have

       * outstanding queries.

       */

      if (active_queries && server->udp_socket != ARES_SOCKET_BAD)

        {

          FD_SET(server->udp_socket, read_fds);

          if (server->udp_socket >= nfds)

            nfds = server->udp_socket + 1;

        }

      /* We always register for TCP events, because we want to know

       * when the other side closes the connection, so we don't waste

       * time trying to use a broken connection.

       */

      if (server->tcp_socket != ARES_SOCKET_BAD)

       {

         FD_SET(server->tcp_socket, read_fds);

         if (server->qhead)

           FD_SET(server->tcp_socket, write_fds);

         if (server->tcp_socket >= nfds)

           nfds = server->tcp_socket + 1;

	}

    }

  return (int)nfds;

}