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/* Copyright (C) 2000-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthread.h>
#include <time.h>
#include "posix-timer.h"
/* Set timer TIMERID to VALUE, returning old value in OVLAUE. */
int
timer_settime (timer_t timerid, int flags, const struct itimerspec *value,
struct itimerspec *ovalue)
{
struct timer_node *timer;
struct thread_node *thread = NULL;
struct timespec now;
int have_now = 0, need_wakeup = 0;
int retval = -1;
timer = timer_id2ptr (timerid);
if (timer == NULL)
{
__set_errno (EINVAL);
goto bail;
}
if (! valid_nanoseconds (value->it_interval.tv_nsec)
|| ! valid_nanoseconds (value->it_value.tv_nsec))
{
__set_errno (EINVAL);
goto bail;
}
/* Will need to know current time since this is a relative timer;
might as well make the system call outside of the lock now! */
if ((flags & TIMER_ABSTIME) == 0)
{
__clock_gettime (timer->clock, &now);
have_now = 1;
}
pthread_mutex_lock (&__timer_mutex);
timer_addref (timer);
/* One final check of timer validity; this one is possible only
until we have the mutex, because it accesses the inuse flag. */
if (! timer_valid(timer))
{
__set_errno (EINVAL);
goto unlock_bail;
}
if (ovalue != NULL)
{
ovalue->it_interval = timer->value.it_interval;
if (timer->armed)
{
if (! have_now)
{
pthread_mutex_unlock (&__timer_mutex);
__clock_gettime (timer->clock, &now);
have_now = 1;
pthread_mutex_lock (&__timer_mutex);
timer_addref (timer);
}
timespec_sub (&ovalue->it_value, &timer->expirytime, &now);
}
else
{
ovalue->it_value.tv_sec = 0;
ovalue->it_value.tv_nsec = 0;
}
}
timer->value = *value;
list_unlink_ip (&timer->links);
timer->armed = 0;
thread = timer->thread;
/* A value of { 0, 0 } causes the timer to be stopped. */
if (value->it_value.tv_sec != 0
|| __builtin_expect (value->it_value.tv_nsec != 0, 1))
{
if ((flags & TIMER_ABSTIME) != 0)
/* The user specified the expiration time. */
timer->expirytime = value->it_value;
else
timespec_add (&timer->expirytime, &now, &value->it_value);
/* Only need to wake up the thread if timer is inserted
at the head of the queue. */
if (thread != NULL)
need_wakeup = __timer_thread_queue_timer (thread, timer);
timer->armed = 1;
}
retval = 0;
unlock_bail:
timer_delref (timer);
pthread_mutex_unlock (&__timer_mutex);
bail:
if (thread != NULL && need_wakeup)
__timer_thread_wakeup (thread);
return retval;
}
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