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5afdca00 UD |
1 | /* Linuxthreads - a simple clone()-based implementation of Posix */ |
2 | /* threads for Linux. */ | |
3 | /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ | |
4 | /* */ | |
5 | /* This program is free software; you can redistribute it and/or */ | |
6 | /* modify it under the terms of the GNU Library General Public License */ | |
7 | /* as published by the Free Software Foundation; either version 2 */ | |
8 | /* of the License, or (at your option) any later version. */ | |
9 | /* */ | |
10 | /* This program 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 */ | |
13 | /* GNU Library General Public License for more details. */ | |
14 | ||
15 | #ifndef _SEMAPHORE_H | |
16 | #define _SEMAPHORE_H 1 | |
17 | ||
18 | #include <features.h> | |
8325d82c | 19 | #include <sys/types.h> |
8e605e78 UD |
20 | #ifdef __USE_XOPEN2K |
21 | # define __need_timespec | |
22 | # include <time.h> | |
23 | #endif | |
5afdca00 | 24 | |
f8afba91 UD |
25 | #ifndef _PTHREAD_DESCR_DEFINED |
26 | /* Thread descriptors. Needed for `sem_t' definition. */ | |
27 | typedef struct _pthread_descr_struct *_pthread_descr; | |
28 | # define _PTHREAD_DESCR_DEFINED | |
29 | #endif | |
5afdca00 | 30 | |
f8afba91 UD |
31 | /* System specific semaphore definition. */ |
32 | typedef struct | |
33 | { | |
34 | struct | |
35 | { | |
36 | long int status; | |
37 | int spinlock; | |
38 | } __sem_lock; | |
39 | int __sem_value; | |
40 | _pthread_descr __sem_waiting; | |
3387a425 | 41 | } sem_t; |
5afdca00 | 42 | |
f8afba91 UD |
43 | |
44 | ||
45 | /* Value returned if `sem_open' failed. */ | |
93a19c64 | 46 | #define SEM_FAILED ((sem_t *) 0) |
f8afba91 UD |
47 | |
48 | /* Maximum value the semaphore can have. */ | |
49 | #define SEM_VALUE_MAX ((int) ((~0u) >> 1)) | |
50 | ||
51 | ||
5afdca00 UD |
52 | __BEGIN_DECLS |
53 | ||
f8afba91 UD |
54 | /* Initialize semaphore object SEM to VALUE. If PSHARED then share it |
55 | with other processes. */ | |
a9b5d2ee | 56 | extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) __THROW; |
f8afba91 UD |
57 | |
58 | /* Free resources associated with semaphore object SEM. */ | |
a9b5d2ee | 59 | extern int sem_destroy (sem_t *__sem) __THROW; |
f8afba91 UD |
60 | |
61 | /* Open a named semaphore NAME with open flaot OFLAG. */ | |
a9b5d2ee | 62 | extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW; |
f8afba91 UD |
63 | |
64 | /* Close descriptor for named semaphore SEM. */ | |
a9b5d2ee | 65 | extern int sem_close (sem_t *__sem) __THROW; |
f8afba91 UD |
66 | |
67 | /* Remove named semaphore NAME. */ | |
a9b5d2ee | 68 | extern int sem_unlink (__const char *__name) __THROW; |
f8afba91 UD |
69 | |
70 | /* Wait for SEM being posted. */ | |
a9b5d2ee | 71 | extern int sem_wait (sem_t *__sem) __THROW; |
f8afba91 | 72 | |
8e605e78 UD |
73 | #ifdef __USE_XOPEN2K |
74 | /* Similar to `sem_wait' but wait only until ABSTIME. */ | |
98cbe360 UD |
75 | extern int sem_timedwait (sem_t *__restrict __sem, |
76 | __const struct timespec *__restrict __abstime) | |
8e605e78 UD |
77 | __THROW; |
78 | #endif | |
79 | ||
f8afba91 | 80 | /* Test whether SEM is posted. */ |
a9b5d2ee | 81 | extern int sem_trywait (sem_t *__sem) __THROW; |
f8afba91 UD |
82 | |
83 | /* Post SEM. */ | |
a9b5d2ee | 84 | extern int sem_post (sem_t *__sem) __THROW; |
f8afba91 UD |
85 | |
86 | /* Get current value of SEM and store it in *SVAL. */ | |
98cbe360 UD |
87 | extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval) |
88 | __THROW; | |
5afdca00 UD |
89 | |
90 | __END_DECLS | |
91 | ||
92 | #endif /* semaphore.h */ |