/*
 * select.C: select(2) socket engine.
 *
 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
 * Rights to this code are as documented in COPYING.
 *
 *
 * Portions of this file were derived from sources bearing the following license:
 * Rights to this code are documented in doc/pod/license.pod.
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)
 */

static char const rcsid[] = "$Id: select.C,v 1.7 2007/09/16 18:54:45 pippijn Exp $";

#include "atheme.h"
#include "internal.h"
#include "datastream.h"

fd_set readfds, writefds;

/*
 * init_socket_queues()
 *
 * inputs:
 *       none
 *
 * outputs:
 *       none
 *
 * side effects:
 *       when using select, we don't need to do anything here.
 */
void
init_socket_queues (void)
{
  return;
}

/*
 * update_select_sets()
 *
 * inputs:
 *       none
 *
 * outputs:
 *       none
 *
 * side effects:
 *       registered sockets are prepared for the select() loop.
 */
static void
update_select_sets (void)
{
  connection_t::list_type::iterator it = connection_t::list.begin ();
  connection_t::list_type::iterator et = connection_t::list.end ();
  connection_t *cptr;

  FD_ZERO (&readfds);
  FD_ZERO (&writefds);

  while (it != et)
    {
      cptr = *it;
      
      if (cptr->is_connecting ())
        FD_SET (cptr->fd, &writefds);
      
      else if (cptr->is_listening ())
        FD_SET (cptr->fd, &readfds);

      if (sendq_nonempty (cptr))
        FD_SET (cptr->fd, &writefds);
      
      else
        FD_SET (cptr->fd, &readfds);

      ++it;
    }
}

/*
 * connection_t::select()
 *
 * inputs:
 *       delay in nanoseconds
 *
 * outputs:
 *       none
 *
 * side effects:
 *       registered sockets and their associated handlers are acted on.
 */
void
connection_t::select (time_t delay)
{
  int sr;
  connection_t::list_type::iterator it = connection_t::list.begin ();
  connection_t::list_type::iterator et = connection_t::list.end ();
  connection_t *cptr;
  timeval to;

  update_select_sets ();
  to.tv_sec = 0;
  to.tv_usec = delay;

  if ((sr = select (system_state.maxfd + 1, &readfds, &writefds, NULL, &to)) > 0)
    {
      /* Iterate twice, so we don't touch freed memory if
       * a connection is closed.
       * -- jilles */
      while (it != et)
        {
          cptr = *it;
          
          if (FD_ISSET (cptr->fd, &writefds))
            {
              if (cptr->is_connecting ())
                cptr.callback.connected (cptr);
              else
                cptr->write_handler (cptr);
            }

          ++it;
        }
      
      for (it = connection_t::list.begin (), et = connection_t::list.end (); it != et; ++it)
        {
          cptr = *it;
          
          if (FD_ISSET (cptr->fd, &readfds))
            {
              cptr->read_handler (cptr);
            }
        }

      for (it = connection_t::list.begin (), et = connection_t::list.end (); it != et; ++it)
        {
          cptr = *it;
          if (cptr->flags & CF_DEAD)
            cptr->close ();
        }
    }
  else
    {
      if (sr == 0)
	{
	  /* select() timed out */
	}
      else if ((sr == -1) && (errno == EINTR))
	{
	  /* some signal interrupted us, restart select() */
	}
      else if (sr == -1)
	{
	  return;
	}
    }
}

/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
 * vim:ts=8
 * vim:sw=8
 * vim:noexpandtab
 */