glibc (2.38)
1 /* Copyright (C) 2002-2023 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 #ifndef _SEMAPHORE_H
19 #define _SEMAPHORE_H 1
20
21 #include <features.h>
22 #include <sys/types.h>
23 #ifdef __USE_XOPEN2K
24 # include <bits/types/struct_timespec.h>
25 #endif
26
27 /* Get the definition for sem_t. */
28 #include <bits/semaphore.h>
29
30
31 __BEGIN_DECLS
32
33 /* Initialize semaphore object SEM to VALUE. If PSHARED then share it
34 with other processes. */
35 extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value)
36 __THROW __nonnull ((1));
37
38 /* Free resources associated with semaphore object SEM. */
39 extern int sem_destroy (sem_t *__sem) __THROW __nonnull ((1));
40
41 /* Open a named semaphore NAME with open flags OFLAG. */
42 extern sem_t *sem_open (const char *__name, int __oflag, ...)
43 __THROW __nonnull ((1));
44
45 /* Close descriptor for named semaphore SEM. */
46 extern int sem_close (sem_t *__sem) __THROW __nonnull ((1));
47
48 /* Remove named semaphore NAME. */
49 extern int sem_unlink (const char *__name) __THROW __nonnull ((1));
50
51 /* Wait for SEM being posted.
52
53 This function is a cancellation point and therefore not marked with
54 __THROW. */
55 extern int sem_wait (sem_t *__sem) __nonnull ((1));
56
57 #ifdef __USE_XOPEN2K
58 /* Similar to `sem_wait' but wait only until ABSTIME.
59
60 This function is a cancellation point and therefore not marked with
61 __THROW. */
62 # ifndef __USE_TIME_BITS64
63 extern int sem_timedwait (sem_t *__restrict __sem,
64 const struct timespec *__restrict __abstime)
65 __nonnull ((1, 2));
66 # else
67 # ifdef __REDIRECT
68 extern int __REDIRECT (sem_timedwait,
69 (sem_t *__restrict __sem,
70 const struct timespec *__restrict __abstime),
71 __sem_timedwait64)
72 __nonnull ((1, 2));
73 # else
74 # define sem_timedwait __sem_timedwait64
75 # endif
76 # endif
77 #endif
78
79 #ifdef __USE_GNU
80 # ifndef __USE_TIME_BITS64
81 extern int sem_clockwait (sem_t *__restrict __sem,
82 clockid_t clock,
83 const struct timespec *__restrict __abstime)
84 __nonnull ((1, 3));
85 # else
86 # ifdef __REDIRECT
87 extern int __REDIRECT (sem_clockwait,
88 (sem_t *__restrict __sem,
89 clockid_t clock,
90 const struct timespec *__restrict __abstime),
91 __sem_clockwait64)
92 __nonnull ((1, 3));
93 # else
94 # define sem_clockwait __sem_clockwait64
95 # endif
96 # endif
97 #endif
98
99 /* Test whether SEM is posted. */
100 extern int sem_trywait (sem_t *__sem) __THROWNL __nonnull ((1));
101
102 /* Post SEM. */
103 extern int sem_post (sem_t *__sem) __THROWNL __nonnull ((1));
104
105 /* Get current value of SEM and store it in *SVAL. */
106 extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
107 __THROW __nonnull ((1, 2));
108
109
110 __END_DECLS
111
112 #endif /* semaphore.h */
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