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/* Sleep a given number of milliseconds.
Copyright (C) 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
François Pinard <pinard@iro.umontreal.ca>, 1992.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
/* This code is heavily borrowed from Taylor UUCP 1.03. Ian picks one of
usleep, nap, napms, poll, select and sleep, in decreasing order of
preference. The sleep function is always available. */
/* In many cases, we will sleep if the wanted number of milliseconds
is higher than this value. */
#define THRESHOLD_FOR_SLEEP 30000
/* Include some header files. */
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_POLL
# if HAVE_STROPTS_H
# include <stropts.h>
# endif
# if HAVE_POLL_H
# include <sys/types.h>
# include <poll.h>
# endif
# if !HAVE_STROPTS_H && !HAVE_POLL_H
/* We need a definition for struct pollfd, although it doesn't matter
what it contains. */
struct pollfd
{
int idummy;
};
# endif
#else
# if HAVE_SELECT
# include <sys/time.h>
# endif
#endif
/*---------------------------------------.
| Sleep a given number of milliseconds. |
`---------------------------------------*/
void
msleep (milliseconds)
int milliseconds;
{
#if HAVE_USLEEP
if (milliseconds > 0)
usleep (milliseconds * (long) 1000);
#else
# if HAVE_NAP
if (milliseconds > 0)
nap ((long) milliseconds);
# else
# if HAVE_NAPMS
if (milliseconds >= THRESHOLD_FOR_SLEEP)
{
sleep (milliseconds / 1000);
milliseconds %= 1000;
}
if (milliseconds > 0)
napms (milliseconds);
# else
# if HAVE_POLL
struct pollfd sdummy; /* poll(2) checks this address */
if (milliseconds >= THRESHOLD_FOR_SLEEP)
{
sleep (milliseconds / 1000);
milliseconds %= 1000;
}
if (milliseconds > 0)
poll (&sdummy, 0, milliseconds);
# else
# if HAVE_SELECT
struct timeval s;
if (milliseconds >= THRESHOLD_FOR_SLEEP)
{
sleep (milliseconds / 1000);
milliseconds %= 1000;
}
if (milliseconds > 0)
{
s.tv_sec = milliseconds / 1000;
s.tv_usec = (milliseconds % 1000) * (long) 1000;
select (0, NULL, NULL, NULL, &s);
}
# else
/* Round the time up to the next full second. */
if (milliseconds > 0)
sleep ((milliseconds + 999) / 1000);
# endif
# endif
# endif
# endif
#endif
}
|
