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/* Copyright (C) 2000-2024 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 <signal.h>
#include <pthread.h>
#include <time.h>
#include <unistd.h>
#include "posix-timer.h"
/* Create new per-process timer using CLOCK. */
int
timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
{
int retval = -1;
struct timer_node *newtimer = NULL;
struct thread_node *thread = NULL;
if (0
#if defined _POSIX_CPUTIME && _POSIX_CPUTIME >= 0
|| clock_id == CLOCK_PROCESS_CPUTIME_ID
#endif
#if defined _POSIX_THREAD_CPUTIME && _POSIX_THREAD_CPUTIME >= 0
|| clock_id == CLOCK_THREAD_CPUTIME_ID
#endif
)
{
/* We don't allow timers for CPU clocks. At least not in the
moment. */
__set_errno (ENOTSUP);
return -1;
}
if (clock_id != CLOCK_REALTIME)
{
__set_errno (EINVAL);
return -1;
}
pthread_once (&__timer_init_once_control, __timer_init_once);
if (__timer_init_failed)
{
__set_errno (ENOMEM);
return -1;
}
pthread_mutex_lock (&__timer_mutex);
newtimer = __timer_alloc ();
if (__glibc_unlikely (newtimer == NULL))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
if (evp != NULL)
newtimer->event = *evp;
else
{
newtimer->event.sigev_notify = SIGEV_SIGNAL;
newtimer->event.sigev_signo = SIGALRM;
newtimer->event.sigev_value.sival_ptr = newtimer;
newtimer->event.sigev_notify_function = 0;
}
newtimer->event.sigev_notify_attributes = &newtimer->attr;
newtimer->creator_pid = getpid ();
switch (__builtin_expect (newtimer->event.sigev_notify, SIGEV_SIGNAL))
{
case SIGEV_NONE:
case SIGEV_SIGNAL:
/* We have a global thread for delivering timed signals.
If it is not running, try to start it up. */
thread = &__timer_signal_thread_rclk;
if (! thread->exists)
{
if (__builtin_expect (__timer_thread_start (thread),
1) < 0)
{
__set_errno (EAGAIN);
goto unlock_bail;
}
}
break;
case SIGEV_THREAD:
/* Copy over thread attributes or set up default ones. */
if (evp->sigev_notify_attributes)
newtimer->attr = *(pthread_attr_t *) evp->sigev_notify_attributes;
else
pthread_attr_init (&newtimer->attr);
/* Ensure thread attributes call for detached thread. */
pthread_attr_setdetachstate (&newtimer->attr, PTHREAD_CREATE_DETACHED);
/* Try to find existing thread having the right attributes. */
thread = __timer_thread_find_matching (&newtimer->attr, clock_id);
/* If no existing thread has these attributes, try to allocate one. */
if (thread == NULL)
thread = __timer_thread_alloc (&newtimer->attr, clock_id);
/* Out of luck; no threads are available. */
if (__glibc_unlikely (thread == NULL))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
/* If the thread is not running already, try to start it. */
if (! thread->exists
&& __builtin_expect (! __timer_thread_start (thread), 0))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
break;
default:
__set_errno (EINVAL);
goto unlock_bail;
}
newtimer->clock = clock_id;
newtimer->abstime = 0;
newtimer->armed = 0;
newtimer->thread = thread;
*timerid = timer_ptr2id (newtimer);
retval = 0;
if (__builtin_expect (retval, 0) == -1)
{
unlock_bail:
if (thread != NULL)
__timer_thread_dealloc (thread);
if (newtimer != NULL)
{
timer_delref (newtimer);
__timer_dealloc (newtimer);
}
}
pthread_mutex_unlock (&__timer_mutex);
return retval;
}
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