1/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <semaphore.h>
20#include <shlib-compat.h>
21#include "semaphoreP.h"
22#include <kernel-features.h>
23#include <futex-internal.h>
24
25
26int
27__new_sem_init (sem_t *sem, int pshared, unsigned int value)
28{
29 ASSERT_PTHREAD_INTERNAL_SIZE (sem_t, struct new_sem);
30
31 /* Parameter sanity check. */
32 if (__glibc_unlikely (value > SEM_VALUE_MAX))
33 {
34 __set_errno (EINVAL);
35 return -1;
36 }
37 pshared = pshared != 0 ? PTHREAD_PROCESS_SHARED : PTHREAD_PROCESS_PRIVATE;
38 int err = futex_supports_pshared (pshared);
39 if (err != 0)
40 {
41 __set_errno (err);
42 return -1;
43 }
44
45 /* Map to the internal type. */
46 struct new_sem *isem = (struct new_sem *) sem;
47
48 /* Use the values the caller provided. */
49#if __HAVE_64B_ATOMICS
50 isem->data = value;
51#else
52 isem->value = value << SEM_VALUE_SHIFT;
53 /* pad is used as a mutex on pre-v9 sparc and ignored otherwise. */
54 isem->pad = 0;
55 isem->nwaiters = 0;
56#endif
57
58 isem->private = (pshared == PTHREAD_PROCESS_PRIVATE
59 ? FUTEX_PRIVATE : FUTEX_SHARED);
60
61 return 0;
62}
63versioned_symbol (libc, __new_sem_init, sem_init, GLIBC_2_34);
64
65#if OTHER_SHLIB_COMPAT(libpthread, GLIBC_2_1, GLIBC_2_34)
66compat_symbol (libpthread, __new_sem_init, sem_init, GLIBC_2_1);
67#endif
68
69#if OTHER_SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
70int
71attribute_compat_text_section
72__old_sem_init (sem_t *sem, int pshared, unsigned int value)
73{
74 ASSERT_PTHREAD_INTERNAL_SIZE (sem_t, struct new_sem);
75
76 /* Parameter sanity check. */
77 if (__glibc_unlikely (value > SEM_VALUE_MAX))
78 {
79 __set_errno (EINVAL);
80 return -1;
81 }
82
83 /* Map to the internal type. */
84 struct old_sem *isem = (struct old_sem *) sem;
85
86 /* Use the value the user provided. */
87 isem->value = value;
88
89 /* We cannot store the PSHARED attribute. So we always use the
90 operations needed for shared semaphores. */
91
92 return 0;
93}
94compat_symbol (libpthread, __old_sem_init, sem_init, GLIBC_2_0);
95#endif
96

source code of glibc/nptl/sem_init.c