semaphore.h

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/*
 *  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.org/license/LICENSE.
 */

#ifndef _SEMAPHORE_H
#define _SEMAPHORE_H

#ifdef __cplusplus
extern "C" {
#endif

#include <unistd.h>

#if defined(_POSIX_SEMAPHORES)

#include <sys/time.h>

/*
 *  11.1 Semaphore Characteristics, P1003.1b-1993, p.219
 */
typedef uint32_t sem_t;

/*
 *  Bad semaphore Id
 */
#define SEM_FAILED ((sem_t *)0)

/*
 *  11.2.1 Initialize an Unnamed Semaphore, P1003.1b-1993, p.219
 */
int sem_init(
  sem_t         *sem,
  int            pshared,
  unsigned int   value
);

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,
  ...
);

int sem_close(
  sem_t *sem
);

int sem_unlink(
  const char *name
);

int sem_wait(
  sem_t *sem
);

int sem_trywait(
  sem_t *sem
);

#if defined(_POSIX_TIMEOUTS)

int sem_timedwait(
  sem_t                 *__restrict sem,
  const struct timespec *__restrict timeout
);
#endif

int sem_post(
  sem_t  *sem
);

int sem_getvalue(
  sem_t  *__restrict sem,
  int    *__restrict sval
);

#endif   /* _POSIX_SEMAPHORES */

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */