90 lines
2.9 KiB
C
90 lines
2.9 KiB
C
/* Linuxthreads - a simple clone()-based implementation of Posix */
|
|
/* threads for Linux. */
|
|
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
|
|
/* */
|
|
/* This program is free software; you can redistribute it and/or */
|
|
/* modify it under the terms of the GNU Library General Public License */
|
|
/* as published by the Free Software Foundation; either version 2 */
|
|
/* of the License, or (at your option) any later version. */
|
|
/* */
|
|
/* This program is distributed in the hope that it will be useful, */
|
|
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
|
|
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
|
|
/* GNU Library General Public License for more details. */
|
|
|
|
#ifndef _SEMAPHORE_H
|
|
#define _SEMAPHORE_H 1
|
|
|
|
#include <features.h>
|
|
#include <sys/types.h>
|
|
#include <bits/pthreadtypes.h>
|
|
#ifdef __USE_XOPEN2K
|
|
# define __need_timespec
|
|
# include <time.h>
|
|
#endif
|
|
|
|
#ifndef _PTHREAD_DESCR_DEFINED
|
|
/* Thread descriptors. Needed for `sem_t' definition. */
|
|
typedef struct _pthread_descr_struct *_pthread_descr;
|
|
# define _PTHREAD_DESCR_DEFINED
|
|
#endif
|
|
|
|
/* System specific semaphore definition. */
|
|
typedef struct
|
|
{
|
|
struct _pthread_fastlock __sem_lock;
|
|
int __sem_value;
|
|
_pthread_descr __sem_waiting;
|
|
} sem_t;
|
|
|
|
|
|
|
|
/* Value returned if `sem_open' failed. */
|
|
#define SEM_FAILED ((sem_t *) 0)
|
|
|
|
/* Maximum value the semaphore can have. */
|
|
#define SEM_VALUE_MAX ((int) ((~0u) >> 1))
|
|
|
|
|
|
__BEGIN_DECLS
|
|
|
|
/* Initialize semaphore object SEM to VALUE. If PSHARED then share it
|
|
with other processes. */
|
|
extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) __THROW;
|
|
|
|
/* Free resources associated with semaphore object SEM. */
|
|
extern int sem_destroy (sem_t *__sem) __THROW;
|
|
|
|
/* Open a named semaphore NAME with open flaot OFLAG. */
|
|
extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW;
|
|
|
|
/* Close descriptor for named semaphore SEM. */
|
|
extern int sem_close (sem_t *__sem) __THROW;
|
|
|
|
/* Remove named semaphore NAME. */
|
|
extern int sem_unlink (__const char *__name) __THROW;
|
|
|
|
/* Wait for SEM being posted. */
|
|
extern int sem_wait (sem_t *__sem) __THROW;
|
|
|
|
#ifdef __USE_XOPEN2K
|
|
/* Similar to `sem_wait' but wait only until ABSTIME. */
|
|
extern int sem_timedwait (sem_t *__restrict __sem,
|
|
__const struct timespec *__restrict __abstime)
|
|
__THROW;
|
|
#endif
|
|
|
|
/* Test whether SEM is posted. */
|
|
extern int sem_trywait (sem_t *__sem) __THROW;
|
|
|
|
/* Post SEM. */
|
|
extern int sem_post (sem_t *__sem) __THROW;
|
|
|
|
/* Get current value of SEM and store it in *SVAL. */
|
|
extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
|
|
__THROW;
|
|
|
|
__END_DECLS
|
|
|
|
#endif /* semaphore.h */
|