1 /* C11 threads mutex initialization implementation.
2    Copyright (C) 2018-2022 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 <stdalign.h>
20 #include <shlib-compat.h>
21 
22 #include "thrd_priv.h"
23 
24 int
__mtx_init(mtx_t * mutex,int type)25 __mtx_init (mtx_t *mutex, int type)
26 {
27   _Static_assert (sizeof (mtx_t) == sizeof (pthread_mutex_t),
28 		  "sizeof (mtx_t) != sizeof (pthread_mutex_t)");
29   _Static_assert (alignof (mtx_t) == alignof (pthread_mutex_t),
30 		  "alignof (mtx_t) != alignof (pthread_mutex_t)");
31 
32   pthread_mutexattr_t attr;
33 
34   __pthread_mutexattr_init (&attr);
35 
36   /* Another possible solution would be to set the flags directly in
37      mutex object. */
38   switch (type)
39   {
40     case mtx_plain | mtx_recursive:
41     case mtx_timed | mtx_recursive:
42       __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
43       break;
44     case mtx_plain:
45     case mtx_timed: /* No difference between both in standard */
46     default:
47       __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_NORMAL);
48       break;
49   }
50 
51   int err_code = __pthread_mutex_init ((pthread_mutex_t *) mutex, &attr);
52   /* pthread_mutexattr_destroy implementation is a noop.  */
53   return thrd_err_map (err_code);
54 }
55 #if PTHREAD_IN_LIBC
56 versioned_symbol (libc, __mtx_init, mtx_init, GLIBC_2_34);
57 # if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_28, GLIBC_2_34)
58 compat_symbol (libpthread, __mtx_init, mtx_init, GLIBC_2_28);
59 # endif
60 #else /* !PTHREAD_IN_LIBC */
61 strong_alias (__mtx_init, mtx_init)
62 #endif
63