nptl/pthread_mutex_destroy.c

   1 /* Copyright (C) 2002-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include "pthreadP.h"
  21
  22 #include <stap-probe.h>
  23
  24
  25 int
  26 __pthread_mutex_destroy (pthread_mutex_t *mutex)
  27 {
  28   LIBC_PROBE (mutex_destroy, 1, mutex);
  29
  30   /* See concurrency notes regarding __kind in struct __pthread_mutex_s
  31      in sysdeps/nptl/bits/thread-shared-types.h.  */
  32   if ((atomic_load_relaxed (&(mutex->__data.__kind))
  33        & PTHREAD_MUTEX_ROBUST_NORMAL_NP) == 0
  34       && mutex->__data.__nusers != 0)
  35     return EBUSY;
  36
  37   /* Set to an invalid value.  Relaxed MO is enough as it is undefined behavior
  38      if the mutex is used after it has been destroyed.  But you can reinitialize
  39      it with pthread_mutex_init.  */
  40   atomic_store_relaxed (&(mutex->__data.__kind), -1);
  41
  42   return 0;
  43 }
  44 weak_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
  45 hidden_def (__pthread_mutex_destroy)