sysdeps/pthread/timer_delete.c

   1 /* Copyright (C) 2000-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Kaz Kylheku <kaz@ashi.footprints.net>.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <pthread.h>
  22 #include <time.h>
  23
  24 #include "posix-timer.h"
  25
  26
  27 /* Delete timer TIMERID.  */
  28 int
  29 timer_delete (timer_t timerid)
  30 {
  31   struct timer_node *timer;
  32   int retval = -1;
  33
  34   pthread_mutex_lock (&__timer_mutex);
  35
  36   timer = timer_id2ptr (timerid);
  37   if (! timer_valid (timer))
  38     /* Invalid timer ID or the timer is not in use.  */
  39     __set_errno (EINVAL);
  40   else
  41     {
  42       if (timer->armed && timer->thread != NULL)
  43         {
  44           struct thread_node *thread = timer->thread;
  45           assert (thread != NULL);
  46
  47           /* If thread is cancelled while waiting for handler to terminate,
  48              the mutex is unlocked and timer_delete is aborted.  */
  49           pthread_cleanup_push (__timer_mutex_cancel_handler, &__timer_mutex);
  50
  51           /* If timer is currently being serviced, wait for it to finish.  */
  52           while (thread->current_timer == timer)
  53             pthread_cond_wait (&thread->cond, &__timer_mutex);
  54
  55           pthread_cleanup_pop (0);
  56         }
  57
  58       /* Remove timer from whatever queue it may be on and deallocate it.  */
  59       timer->inuse = TIMER_DELETED;
  60       list_unlink_ip (&timer->links);
  61       timer_delref (timer);
  62       retval = 0;
  63     }
  64
  65   pthread_mutex_unlock (&__timer_mutex);
  66
  67   return retval;
  68 }