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/* Copyright (C) 2003-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
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 <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sysdep.h>
#include <internaltypes.h>
#include <nptl/pthreadP.h>
#include "kernel-posix-timers.h"
#include "kernel-posix-cpu-timers.h"
#ifdef timer_create_alias
# define timer_create timer_create_alias
#endif
int
timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
{
#undef timer_create
{
clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID
? MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED)
: clock_id == CLOCK_THREAD_CPUTIME_ID
? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
: clock_id);
/* If the user wants notification via a thread we need to handle
this special. */
if (evp == NULL
|| __builtin_expect (evp->sigev_notify != SIGEV_THREAD, 1))
{
struct sigevent local_evp;
/* We avoid allocating too much memory by basically
using struct timer as a derived class with the
first two elements being in the superclass. We only
need these two elements here. */
struct timer *newp = (struct timer *) malloc (offsetof (struct timer,
thrfunc));
if (newp == NULL)
/* No more memory. */
return -1;
if (evp == NULL)
{
/* The kernel has to pass up the timer ID which is a
userlevel object. Therefore we cannot leave it up to
the kernel to determine it. */
local_evp.sigev_notify = SIGEV_SIGNAL;
local_evp.sigev_signo = SIGALRM;
local_evp.sigev_value.sival_ptr = newp;
evp = &local_evp;
}
kernel_timer_t ktimerid;
int retval = INLINE_SYSCALL (timer_create, 3, syscall_clockid, evp,
&ktimerid);
if (retval != -1)
{
newp->sigev_notify = (evp != NULL
? evp->sigev_notify : SIGEV_SIGNAL);
newp->ktimerid = ktimerid;
*timerid = (timer_t) newp;
}
else
{
/* Cannot allocate the timer, fail. */
free (newp);
retval = -1;
}
return retval;
}
else
{
/* Create the helper thread. */
pthread_once (&__helper_once, __start_helper_thread);
if (__helper_tid == 0)
{
/* No resources to start the helper thread. */
__set_errno (EAGAIN);
return -1;
}
struct timer *newp;
newp = (struct timer *) malloc (sizeof (struct timer));
if (newp == NULL)
return -1;
/* Copy the thread parameters the user provided. */
newp->sival = evp->sigev_value;
newp->thrfunc = evp->sigev_notify_function;
newp->sigev_notify = SIGEV_THREAD;
/* We cannot simply copy the thread attributes since the
implementation might keep internal information for
each instance. */
(void) pthread_attr_init (&newp->attr);
if (evp->sigev_notify_attributes != NULL)
{
struct pthread_attr *nattr;
struct pthread_attr *oattr;
nattr = (struct pthread_attr *) &newp->attr;
oattr = (struct pthread_attr *) evp->sigev_notify_attributes;
nattr->schedparam = oattr->schedparam;
nattr->schedpolicy = oattr->schedpolicy;
nattr->flags = oattr->flags;
nattr->guardsize = oattr->guardsize;
nattr->stackaddr = oattr->stackaddr;
nattr->stacksize = oattr->stacksize;
}
/* In any case set the detach flag. */
(void) pthread_attr_setdetachstate (&newp->attr,
PTHREAD_CREATE_DETACHED);
/* Create the event structure for the kernel timer. */
struct sigevent sev =
{ .sigev_value.sival_ptr = newp,
.sigev_signo = SIGTIMER,
.sigev_notify = SIGEV_SIGNAL | SIGEV_THREAD_ID,
._sigev_un = { ._pad = { [0] = __helper_tid } } };
/* Create the timer. */
int res;
res = INTERNAL_SYSCALL_CALL (timer_create,
syscall_clockid, &sev, &newp->ktimerid);
if (! INTERNAL_SYSCALL_ERROR_P (res))
{
/* Add to the queue of active timers with thread
delivery. */
pthread_mutex_lock (&__active_timer_sigev_thread_lock);
newp->next = __active_timer_sigev_thread;
__active_timer_sigev_thread = newp;
pthread_mutex_unlock (&__active_timer_sigev_thread_lock);
*timerid = (timer_t) newp;
return 0;
}
/* Free the resources. */
free (newp);
__set_errno (INTERNAL_SYSCALL_ERRNO (res));
return -1;
}
}
}
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