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/* Provide a replacement for the POSIX nanosleep function.
Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006 Free Software
Foundation, Inc.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* written by Jim Meyering */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
/* Undefine nanosleep here so any prototype is not redefined to be a
prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2) */
#undef nanosleep
#include <stdbool.h>
#include <stdio.h>
#if HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif
#include <sys/types.h>
#include <signal.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#include <errno.h>
#include <unistd.h>
#include "timespec.h"
/* Some systems (MSDOS) don't have SIGCONT.
Using SIGTERM here turns the signal-handling code below
into a no-op on such systems. */
#ifndef SIGCONT
# define SIGCONT SIGTERM
#endif
#if ! HAVE_SIGINTERRUPT
# define siginterrupt(sig, flag) /* empty */
#endif
static sig_atomic_t volatile suspended;
/* Handle SIGCONT. */
static void
sighandler (int sig)
{
suspended = 1;
}
/* Suspend execution for at least *TS_DELAY seconds. */
static void
my_usleep (const struct timespec *ts_delay)
{
struct timeval tv_delay;
tv_delay.tv_sec = ts_delay->tv_sec;
tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
if (tv_delay.tv_usec == 1000000)
{
time_t t1 = tv_delay.tv_sec + 1;
if (t1 < tv_delay.tv_sec)
tv_delay.tv_usec = 1000000 - 1; /* close enough */
else
{
tv_delay.tv_sec = t1;
tv_delay.tv_usec = 0;
}
}
select (0, NULL, NULL, NULL, &tv_delay);
}
/* Suspend execution for at least *REQUESTED_DELAY seconds. The
*REMAINING_DELAY part isn't implemented yet. */
int
rpl_nanosleep (const struct timespec *requested_delay,
struct timespec *remaining_delay)
{
static bool initialized;
/* set up sig handler */
if (! initialized)
{
#ifdef SA_NOCLDSTOP
struct sigaction oldact, newact;
newact.sa_handler = sighandler;
sigemptyset (&newact.sa_mask);
newact.sa_flags = 0;
sigaction (SIGCONT, NULL, &oldact);
if (oldact.sa_handler != SIG_IGN)
sigaction (SIGCONT, &newact, NULL);
#else
if (signal (SIGCONT, SIG_IGN) != SIG_IGN)
{
signal (SIGCONT, sighandler);
siginterrupt (SIGCONT, 1);
}
#endif
initialized = true;
}
suspended = 0;
my_usleep (requested_delay);
if (suspended)
{
/* Calculate time remaining. */
/* FIXME: the code in sleep doesn't use this, so there's no
rush to implement it. */
errno = EINTR;
}
/* FIXME: Restore sig handler? */
return suspended;
}
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