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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)usleep.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
#endif
#if !defined(_THREAD_SAFE) && !defined(USE_NANOSLEEP)
#define TICK 10000 /* system clock resolution in microseconds */
#define USPS 1000000 /* number of microseconds in a second */
#endif
#ifndef _THREAD_SAFE
#ifndef USE_NANOSLEEP
#define setvec(vec, a) \
vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
static int ringring;
#endif
static void
sleephandler()
{
#ifndef USE_NANOSLEEP
ringring = 1;
#endif
}
#endif /* _THREAD_SAFE */
void
usleep(useconds)
unsigned int useconds;
{
#ifdef _THREAD_SAFE
struct timespec time_to_sleep;
struct timespec time_remaining;
if (useconds) {
time_to_sleep.tv_nsec = (useconds % 1000000) * 1000;
time_to_sleep.tv_sec = useconds / 1000000;
do {
nanosleep(&time_to_sleep, &time_remaining);
time_to_sleep = time_remaining;
} while (time_to_sleep.tv_sec != 0 &&
time_to_sleep.tv_nsec != 0);
}
#else
#ifdef USE_NANOSLEEP
struct timespec time_to_sleep;
struct timespec time_remaining;
struct sigaction act, oact;
sigset_t mask, omask;
int alarm_blocked;
if (useconds != 0) {
time_to_sleep.tv_nsec = (useconds % 1000000) * 1000;
time_to_sleep.tv_sec = useconds / 1000000;
/* Block SIGALRM while fiddling with it */
sigemptyset(&mask);
sigaddset(&mask, SIGALRM);
sigprocmask(SIG_BLOCK, &mask, &omask);
/* Was SIGALRM blocked already? */
alarm_blocked = sigismember(&omask, SIGALRM);
if (!alarm_blocked) {
/*
* Set up handler to interrupt signanosleep only if
* SIGALRM was unblocked. (Save some syscalls)
*/
memset(&act, 0, sizeof(act));
act.sa_handler = sleephandler;
sigaction(SIGALRM, &act, &oact);
}
/*
* signanosleep() uses the given mask for the lifetime of
* the syscall only - it resets on return. Note that the
* Old sleep explicitly unblocks SIGALRM during the sleep,
* we don't do that now since we don't depend on SIGALRM
* to end the timout. If the process blocks SIGALRM, it
* gets what it asks for.
*/
do {
signanosleep(&time_to_sleep, &time_remaining, &mask);
time_to_sleep = time_remaining;
} while (time_to_sleep.tv_sec != 0 &&
time_to_sleep.tv_nsec != 0);
if (!alarm_blocked) {
/* Unwind */
sigaction(SIGALRM, &oact, (struct sigaction *)0);
sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
}
}
#else
register struct itimerval *itp;
struct itimerval itv, oitv;
struct sigvec vec, ovec;
long omask;
static void sleephandler();
itp = &itv;
if (!useconds)
return;
timerclear(&itp->it_interval);
timerclear(&itp->it_value);
if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
return;
itp->it_value.tv_sec = useconds / USPS;
itp->it_value.tv_usec = useconds % USPS;
if (timerisset(&oitv.it_value)) {
if (timercmp(&oitv.it_value, &itp->it_value, >)) {
oitv.it_value.tv_sec -= itp->it_value.tv_sec;
oitv.it_value.tv_usec -= itp->it_value.tv_usec;
if (oitv.it_value.tv_usec < 0) {
oitv.it_value.tv_usec += USPS;
oitv.it_value.tv_sec--;
}
} else {
itp->it_value = oitv.it_value;
oitv.it_value.tv_sec = 0;
oitv.it_value.tv_usec = 2 * TICK;
}
}
setvec(vec, sleephandler);
(void) sigvec(SIGALRM, &vec, &ovec);
omask = sigblock(sigmask(SIGALRM));
ringring = 0;
(void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
while (!ringring)
sigpause(omask &~ sigmask(SIGALRM));
(void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
(void) sigsetmask(omask);
(void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
#endif /* USE_NANOSLEEP */
#endif /* _THREAD_SAFE */
}
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