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/**
* @file
*
* @brief Private Support Information for POSIX Semaphores
*
* This file contains definitions that are internal to the RTEMS
* implementation of POSIX Semaphores.
*/
/*
* COPYRIGHT (c) 1989-2011.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifndef _SEMAPHORE_H
#define _SEMAPHORE_H
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup POSIX_SEMAPHORE POSIX Semaphores Support
*
* @ingroup POSIXAPI
*
* @brief Private Support Information for POSIX Semaphores
*/
#include <unistd.h>
#if defined(_POSIX_SEMAPHORES)
#include <sys/time.h>
/*
* 11.1 Semaphore Characteristics, P1003.1b-1993, p.219
*/
typedef int sem_t;
/*
* Bad semaphore Id
*/
#define SEM_FAILED (sem_t *) -1
/*
* 11.2.1 Initialize an Unnamed Semaphore, P1003.1b-1993, p.219
*/
int sem_init(
sem_t *sem,
int pshared,
unsigned int value
);
/**
* @brief Destroy an unnamed semaphore.
*
* 11.2.2 Destroy an Unnamed Semaphore, P1003.1b-1993, p.220
*/
int sem_destroy(
sem_t *sem
);
/*
* 11.2.3 Initialize/Open a Named Semaphore, P1003.1b-1993, p.221
*
* NOTE: Follows open() calling conventions.
*/
sem_t *sem_open(
const char *name,
int oflag,
...
);
/**
* @brief Close a named semaphore.
*
* Routine to close a semaphore that has been opened or initialized.
*
* 11.2.4 Close a Named Semaphore, P1003.1b-1993, p.224
*/
int sem_close(
sem_t *sem
);
/**
* @brief Remove a named semaphore.
*
* Unlinks a named semaphore, sem_close must also be called to remove
* the semaphore.
*
* 11.2.5 Remove a Named Semaphore, P1003.1b-1993, p.225
*/
int sem_unlink(
const char *name
);
/**
* @brief Lock a semaphore.
*
* 11.2.6 Lock a Semaphore, P1003.1b-1993, p.226
*
* NOTE: P1003.4b/D8 adds sem_timedwait(), p. 27
*/
int sem_wait(
sem_t *sem
);
/**
* @brief Lock a semaphore.
*
* @see sem_wait()
*/
int sem_trywait(
sem_t *sem
);
#if defined(_POSIX_TIMEOUTS)
/**
* @brief Lock a semaphore.
*/
int sem_timedwait(
sem_t *__restrict sem,
const struct timespec *__restrict timeout
);
#endif
/**
* @brief Unlock a semaphore.
*
* 11.2.7 Unlock a Semaphore, P1003.1b-1993, p.227
*/
int sem_post(
sem_t *sem
);
/**
* @brief Get the value of a semaphore.
*
* 11.2.8 Get the Value of a Semaphore, P1003.1b-1993, p.229
*/
int sem_getvalue(
sem_t *__restrict sem,
int *__restrict sval
);
#endif /* _POSIX_SEMAPHORES */
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
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