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123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
/* Provide a replacement for the POSIX nanosleep function.
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Copyright (C) 1999, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* written by Jim Meyering */
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#include <config.h>
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/* Undefine nanosleep here so any prototype is not redefined to be a
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prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2) */
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#undef nanosleep
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#include <stdbool.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <signal.h>
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#include <errno.h>
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#if HAVE_UNISTD_H
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# include <unistd.h>
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#endif
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#include "timespec.h"
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/* Some systems (MSDOS) don't have SIGCONT.
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Using SIGTERM here turns the signal-handling code below
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into a no-op on such systems. */
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#ifndef SIGCONT
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# define SIGCONT SIGTERM
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#endif
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#if ! HAVE_SIGINTERRUPT
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# define siginterrupt(sig, flag) /* empty */
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#endif
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static sig_atomic_t volatile suspended;
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/* Handle SIGCONT. */
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static void
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sighandler (int sig)
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{
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suspended = 1;
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}
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/* FIXME: comment */
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static void
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my_usleep (const struct timespec *ts_delay)
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{
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struct timeval tv_delay;
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tv_delay.tv_sec = ts_delay->tv_sec;
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tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
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if (tv_delay.tv_usec == 1000000)
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{
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tv_delay.tv_sec++;
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tv_delay.tv_usec = 0;
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}
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select (0, NULL, NULL, NULL, &tv_delay);
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}
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/* FIXME: comment */
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int
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rpl_nanosleep (const struct timespec *requested_delay,
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struct timespec *remaining_delay)
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{
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static bool initialized;
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/* set up sig handler */
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if (! initialized)
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{
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#ifdef SA_NOCLDSTOP
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struct sigaction oldact, newact;
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newact.sa_handler = sighandler;
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sigemptyset (&newact.sa_mask);
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newact.sa_flags = 0;
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sigaction (SIGCONT, NULL, &oldact);
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if (oldact.sa_handler != SIG_IGN)
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sigaction (SIGCONT, &newact, NULL);
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#else
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if (signal (SIGCONT, SIG_IGN) != SIG_IGN)
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{
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signal (SIGCONT, sighandler);
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siginterrupt (SIGCONT, 1);
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}
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#endif
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initialized = true;
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}
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suspended = 0;
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my_usleep (requested_delay);
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if (suspended)
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{
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/* Calculate time remaining. */
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/* FIXME: the code in sleep doesn't use this, so there's no
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rush to implement it. */
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errno = EINTR;
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}
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/* FIXME: Restore sig handler? */
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return suspended;
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}
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