| 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> |
|---|
| 19 | #include <sys/types.h> |
|---|
| 20 | #ifdef __USE_XOPEN2K |
|---|
| 21 | # define __need_timespec |
|---|
| 22 | # include <time.h> |
|---|
| 23 | #endif |
|---|
| 24 | |
|---|
| 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 |
|---|
| 30 | |
|---|
| 31 | /* System specific semaphore definition. */ |
|---|
| 32 | typedef struct |
|---|
| 33 | { |
|---|
| 34 | struct _pthread_fastlock __sem_lock; |
|---|
| 35 | int __sem_value; |
|---|
| 36 | _pthread_descr __sem_waiting; |
|---|
| 37 | } sem_t; |
|---|
| 38 | |
|---|
| 39 | |
|---|
| 40 | |
|---|
| 41 | /* Value returned if `sem_open' failed. */ |
|---|
| 42 | #define SEM_FAILED ((sem_t *) 0) |
|---|
| 43 | |
|---|
| 44 | /* Maximum value the semaphore can have. */ |
|---|
| 45 | #define SEM_VALUE_MAX ((int) ((~0u) >> 1)) |
|---|
| 46 | |
|---|
| 47 | |
|---|
| 48 | __BEGIN_DECLS |
|---|
| 49 | |
|---|
| 50 | /* Initialize semaphore object SEM to VALUE. If PSHARED then share it |
|---|
| 51 | with other processes. */ |
|---|
| 52 | extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) __THROW; |
|---|
| 53 | |
|---|
| 54 | /* Free resources associated with semaphore object SEM. */ |
|---|
| 55 | extern int sem_destroy (sem_t *__sem) __THROW; |
|---|
| 56 | |
|---|
| 57 | /* Open a named semaphore NAME with open flaot OFLAG. */ |
|---|
| 58 | extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW; |
|---|
| 59 | |
|---|
| 60 | /* Close descriptor for named semaphore SEM. */ |
|---|
| 61 | extern int sem_close (sem_t *__sem) __THROW; |
|---|
| 62 | |
|---|
| 63 | /* Remove named semaphore NAME. */ |
|---|
| 64 | extern int sem_unlink (__const char *__name) __THROW; |
|---|
| 65 | |
|---|
| 66 | /* Wait for SEM being posted. */ |
|---|
| 67 | extern int sem_wait (sem_t *__sem) __THROW; |
|---|
| 68 | |
|---|
| 69 | #ifdef __USE_XOPEN2K |
|---|
| 70 | /* Similar to `sem_wait' but wait only until ABSTIME. */ |
|---|
| 71 | extern int sem_timedwait (sem_t *__restrict __sem, |
|---|
| 72 | __const struct timespec *__restrict __abstime) |
|---|
| 73 | __THROW; |
|---|
| 74 | #endif |
|---|
| 75 | |
|---|
| 76 | /* Test whether SEM is posted. */ |
|---|
| 77 | extern int sem_trywait (sem_t *__sem) __THROW; |
|---|
| 78 | |
|---|
| 79 | /* Post SEM. */ |
|---|
| 80 | extern int sem_post (sem_t *__sem) __THROW; |
|---|
| 81 | |
|---|
| 82 | /* Get current value of SEM and store it in *SVAL. */ |
|---|
| 83 | extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval) |
|---|
| 84 | __THROW; |
|---|
| 85 | |
|---|
| 86 | __END_DECLS |
|---|
| 87 | |
|---|
| 88 | #endif /* semaphore.h */ |
|---|
