1 /* Linuxthreads - a simple clone()-based implementation of Posix */
2 /* threads for Linux. */
3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
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. */
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. */
16 #define _SEMAPHORE_H 1
19 #include <sys/types.h>
21 # define __need_timespec
24 #include <bits/pthreadtypes.h>
26 #ifndef _PTHREAD_DESCR_DEFINED
27 /* Thread descriptors. Needed for `sem_t' definition. */
28 typedef struct _pthread_descr_struct
*_pthread_descr
;
29 # define _PTHREAD_DESCR_DEFINED
32 /* System specific semaphore definition. */
35 struct _pthread_fastlock __sem_lock
;
37 _pthread_descr __sem_waiting
;
42 /* Value returned if `sem_open' failed. */
43 #define SEM_FAILED ((sem_t *) 0)
45 /* Maximum value the semaphore can have. */
46 #define SEM_VALUE_MAX (2147483647)
51 /* Initialize semaphore object SEM to VALUE. If PSHARED then share it
52 with other processes. */
53 extern int sem_init (sem_t
*__sem
, int __pshared
, unsigned int __value
) __THROW
;
55 /* Free resources associated with semaphore object SEM. */
56 extern int sem_destroy (sem_t
*__sem
) __THROW
;
58 /* Open a named semaphore NAME with open flaot OFLAG. */
59 extern sem_t
*sem_open (__const
char *__name
, int __oflag
, ...) __THROW
;
61 /* Close descriptor for named semaphore SEM. */
62 extern int sem_close (sem_t
*__sem
) __THROW
;
64 /* Remove named semaphore NAME. */
65 extern int sem_unlink (__const
char *__name
) __THROW
;
67 /* Wait for SEM being posted. */
68 extern int sem_wait (sem_t
*__sem
);
71 /* Similar to `sem_wait' but wait only until ABSTIME. */
72 extern int sem_timedwait (sem_t
*__restrict __sem
,
73 __const
struct timespec
*__restrict __abstime
);
76 /* Test whether SEM is posted. */
77 extern int sem_trywait (sem_t
*__sem
) __THROW
;
80 extern int sem_post (sem_t
*__sem
) __THROW
;
82 /* Get current value of SEM and store it in *SVAL. */
83 extern int sem_getvalue (sem_t
*__restrict __sem
, int *__restrict __sval
)
88 #endif /* semaphore.h */