NetBSD/lib/libpthread/pthread_alarms.c

230 lines
7.1 KiB
C

/* $NetBSD: pthread_alarms.c,v 1.13 2006/03/19 23:01:03 christos Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* 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 NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: pthread_alarms.c,v 1.13 2006/03/19 23:01:03 christos Exp $");
#include <err.h>
#include <sys/time.h>
#include <stdlib.h>
#include "pthread.h"
#include "pthread_int.h"
timer_t pthread_alarmtimer;
PTQ_HEAD(, pt_alarm_t) pthread_alarmqueue = PTQ_HEAD_INITIALIZER;
pthread_spin_t pthread_alarmqlock = __SIMPLELOCK_UNLOCKED;
#ifdef PTHREAD_ALARM_DEBUG
#define SDPRINTF(x) DPRINTF(x)
#else
#define SDPRINTF(x)
#endif
void
pthread__alarm_init(void)
{
struct sigevent ev;
int retval;
ev.sigev_notify = SIGEV_SA;
ev.sigev_signo = 0;
ev.sigev_value.sival_int = (int)PT_ALARMTIMER_MAGIC;
retval = timer_create(CLOCK_REALTIME, &ev, &pthread_alarmtimer);
pthread__assert(retval == 0);
}
void
pthread__alarm_add(pthread_t self, struct pt_alarm_t *alarm,
const struct timespec *ts, void (*func)(void *), void *arg)
{
struct pt_alarm_t *iterator, *prev;
struct itimerspec it;
int retval;
pthread_lockinit(&alarm->pta_lock);
alarm->pta_time = ts;
alarm->pta_func = func;
alarm->pta_arg = arg;
alarm->pta_fired = 0;
SDPRINTF(("(alarm_add %p) alarm %p for %d.%06ld\n",
self, alarm, ts->tv_sec, ts->tv_nsec/1000));
prev = NULL;
pthread_spinlock(self, &pthread_alarmqlock);
PTQ_FOREACH(iterator, &pthread_alarmqueue, pta_next) {
if (timespeccmp(ts, iterator->pta_time, <))
break;
prev = iterator;
}
if (iterator == PTQ_FIRST(&pthread_alarmqueue)) {
PTQ_INSERT_HEAD(&pthread_alarmqueue, alarm, pta_next);
timespecclear(&it.it_interval);
/*
* A zero-valued timespec will disarm the timer, but is
* a legitimate value for the _timedwait functions to
* pass in. Correct for this here and in other timer-resetting
* code by setting it_value to a small value that is
* safely in the past.
*/
if (timespecisset(ts)) {
it.it_value = *ts;
} else {
it.it_value.tv_sec = 1;
it.it_value.tv_nsec = 0;
}
SDPRINTF(("(add %p) resetting alarm timer to %d.%06d\n",
self, it.it_value.tv_sec, it.it_value.tv_nsec/1000));
retval = timer_settime(pthread_alarmtimer, TIMER_ABSTIME,
&it, NULL);
pthread__assert(retval == 0);
} else if (prev != NULL) {
PTQ_INSERT_AFTER(&pthread_alarmqueue, prev, alarm, pta_next);
}
pthread_spinunlock(self, &pthread_alarmqlock);
}
void
pthread__alarm_del(pthread_t self, struct pt_alarm_t *alarm)
{
struct pt_alarm_t *next;
struct itimerspec it;
int retval;
next = NULL;
pthread_spinlock(self, &pthread_alarmqlock);
pthread_spinlock(self, &alarm->pta_lock);
SDPRINTF(("(del %p) alarm %p\n", self, alarm));
if (alarm->pta_fired == 0) {
if (alarm == PTQ_FIRST(&pthread_alarmqueue)) {
next = PTQ_NEXT(alarm, pta_next);
timespecclear(&it.it_interval);
if (next != NULL)
/* See comment in pthread__alarm_add() */
if (timespecisset(next->pta_time)) {
it.it_value = *next->pta_time;
} else {
it.it_value.tv_sec = 1;
it.it_value.tv_nsec = 0;
}
else
timespecclear(&it.it_value);
SDPRINTF(("(del %p) resetting alarm timer to %d.%06d\n",
self, it.it_value.tv_sec, it.it_value.tv_nsec/1000));
retval = timer_settime(pthread_alarmtimer, TIMER_ABSTIME, &it,
NULL);
pthread__assert(retval == 0);
}
PTQ_REMOVE(&pthread_alarmqueue, alarm, pta_next);
}
pthread_spinunlock(self, &alarm->pta_lock);
pthread_spinunlock(self, &pthread_alarmqlock);
}
int
pthread__alarm_fired(struct pt_alarm_t *alarm)
{
return alarm->pta_fired;
}
void
/*ARGSUSED*/
pthread__alarm_process(pthread_t self, void *arg)
{
struct timespec ts;
struct itimerspec it;
struct pt_alarm_t *iterator, *next;
PTQ_HEAD(, pt_alarm_t) runq;
int retval;
clock_gettime(CLOCK_REALTIME, &ts);
SDPRINTF(("(pro %p) alarm time %d.%06ld\n",
self, ts.tv_sec, ts.tv_nsec / 1000));
PTQ_INIT(&runq);
pthread_spinlock(self, &pthread_alarmqlock);
/* 1. Collect a list of all alarms whose time has passed. */
for (iterator = next = PTQ_FIRST(&pthread_alarmqueue);
iterator;
iterator = next) {
if (timespeccmp(&ts, iterator->pta_time, <=))
break;
pthread_spinlock(self, &iterator->pta_lock);
next = PTQ_NEXT(iterator, pta_next);
PTQ_REMOVE(&pthread_alarmqueue, iterator, pta_next);
PTQ_INSERT_TAIL(&runq, iterator, pta_next);
SDPRINTF(("(pro %p) collect alarm %p\n", self, iterator));
}
/* 2. Reset the timer for the next element in the queue. */
if (next) {
timespecclear(&it.it_interval);
/* See comment in pthread__alarm_add() */
if (timespecisset(next->pta_time)) {
it.it_value = *next->pta_time;
} else {
it.it_value.tv_sec = 1;
it.it_value.tv_nsec = 0;
}
SDPRINTF(("(pro %p) resetting alarm timer to %d.%09d\n", self,
it.it_value.tv_sec, it.it_value.tv_nsec));
retval = timer_settime(pthread_alarmtimer, TIMER_ABSTIME, &it, NULL);
pthread__assert(retval == 0);
}
pthread_spinunlock(self, &pthread_alarmqlock);
/* 3. Call the functions for all passed alarms. */
for (iterator = next = PTQ_FIRST(&runq);
iterator;
iterator = next) {
SDPRINTF(("(pro %p) calling function for alarm %p\n", self, iterator));
(*iterator->pta_func)(iterator->pta_arg);
iterator->pta_fired = 1;
next = PTQ_NEXT(iterator, pta_next);
pthread_spinunlock(self, &iterator->pta_lock);
}
SDPRINTF(("(pro %p) done\n", self, iterator));
}