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/* 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>
#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
{
long int status;
int spinlock;
} __sem_lock;
int __sem_value;
_pthread_descr __sem_waiting;
} sem_t;
/* Value returned if `sem_open' failed. */
#define SEM_FAILED ((sem_t *) NULL)
/* 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;
/* 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 *__sem, int *__sval) __THROW;
__END_DECLS
#endif /* semaphore.h */
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