glibc/sysdeps/unix/sysv/linux/timer_delete.c

/* Copyright (C) 2003-2021 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 <stdlib.h>
#include <time.h>
#include <sysdep.h>
#include "kernel-posix-timers.h"


#ifdef timer_delete_alias
# define timer_delete timer_delete_alias
#endif


int
timer_delete (timer_t timerid)
{
#undef timer_delete
  kernel_timer_t ktimerid = timerid_to_kernel_timer (timerid);
  int res = INLINE_SYSCALL_CALL (timer_delete, ktimerid);

  if (res == 0)
    {
      if (timer_is_sigev_thread (timerid))
	{
	  struct timer *kt = timerid_to_timer (timerid);

	  /* Remove the timer from the list.  */
	  pthread_mutex_lock (&__active_timer_sigev_thread_lock);
	  if (__active_timer_sigev_thread == kt)
	    __active_timer_sigev_thread = kt->next;
	  else
	    {
	      struct timer *prevp = __active_timer_sigev_thread;
	      while (prevp->next != NULL)
		if (prevp->next == kt)
		  {
		    prevp->next = kt->next;
		    break;
		  }
		else
		  prevp = prevp->next;
	    }
	  pthread_mutex_unlock (&__active_timer_sigev_thread_lock);

	  free (kt);
	}

      return 0;
    }

  /* The kernel timer is not known or something else bad happened.
     Return the error.  */
  return -1;
}