rt/timer_delete.c

   1 /* Copyright (C) 2000-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If
  16    not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  19 #include <errno.h>
  20 #include <pthread.h>
  21 #include <time.h>
  22
  23 #include "posix-timer.h"
  24
  25
  26 /* Delete timer TIMERID.  */
  27 int
  28 timer_delete (timer_t timerid)
  29 {
  30   struct timer_node *timer;
  31   int retval = -1;
  32
  33   pthread_mutex_lock (&__timer_mutex);
  34
  35   timer = timer_id2ptr (timerid);
  36   if (! timer_valid (timer))
  37     /* Invalid timer ID or the timer is not in use.  */
  38     __set_errno (EINVAL);
  39   else
  40     {
  41       if (timer->armed && timer->thread != NULL)
  42         {
  43           struct thread_node *thread = timer->thread;
  44           assert (thread != NULL);
  45
  46           /* If thread is cancelled while waiting for handler to terminate,
  47              the mutex is unlocked and timer_delete is aborted.  */
  48           pthread_cleanup_push (__timer_mutex_cancel_handler, &__timer_mutex);
  49
  50           /* If timer is currently being serviced, wait for it to finish.  */
  51           while (thread->current_timer == timer)
  52             pthread_cond_wait (&thread->cond, &__timer_mutex);
  53
  54           pthread_cleanup_pop (0);
  55         }
  56
  57       /* Remove timer from whatever queue it may be on and deallocate it.  */
  58       timer->inuse = TIMER_DELETED;
  59       list_unlink_ip (&timer->links);
  60       timer_delref (timer);
  61       retval = 0;
  62     }
  63
  64   pthread_mutex_unlock (&__timer_mutex);
  65
  66   return retval;
  67 }