1/* C11 threads call once implementation.
2 Copyright (C) 2018-2024 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
24void
25__call_once (once_flag *flag, void (*func)(void))
26{
27 _Static_assert (sizeof (once_flag) == sizeof (pthread_once_t),
28 "sizeof (once_flag) != sizeof (pthread_once_t)");
29 _Static_assert (alignof (once_flag) == alignof (pthread_once_t),
30 "alignof (once_flag) != alignof (pthread_once_t)");
31 __pthread_once ((pthread_once_t *) flag, func);
32}
33#if PTHREAD_IN_LIBC
34versioned_symbol (libc, __call_once, call_once, GLIBC_2_34);
35# if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_28, GLIBC_2_34)
36compat_symbol (libpthread, __call_once, call_once, GLIBC_2_28);
37# endif
38#else /* !PTHREAD_IN_LIBC */
39strong_alias (__call_once, call_once)
40#endif
41

source code of glibc/sysdeps/pthread/call_once.c