1 /* Destroy a semaphore.  Generic version.
2    Copyright (C) 2005-2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
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 <semaphore.h>
20 #include <errno.h>
21 
22 #include <pt-internal.h>
23 
24 int
__sem_destroy(sem_t * sem)25 __sem_destroy (sem_t *sem)
26 {
27   struct new_sem *isem = (struct new_sem *) sem;
28   if (
29 #if __HAVE_64B_ATOMICS
30       atomic_load_relaxed (&isem->data) >> SEM_NWAITERS_SHIFT
31 #else
32       atomic_load_relaxed (&isem->value) & SEM_NWAITERS_MASK
33       || isem->nwaiters
34 #endif
35       )
36     /* There are threads waiting on *SEM.  */
37     {
38       errno = EBUSY;
39       return -1;
40     }
41 
42   return 0;
43 }
44 
45 strong_alias (__sem_destroy, sem_destroy);
46