glibc/sysdeps/pthread/semaphore.h

/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _SEMAPHORE_H
#define _SEMAPHORE_H	1

#include <features.h>
#include <sys/types.h>
#ifdef __USE_XOPEN2K
# include <bits/types/struct_timespec.h>
#endif

/* Get the definition for sem_t.  */
#include <bits/semaphore.h>


__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 __nonnull ((1));

/* Free resources associated with semaphore object SEM.  */
extern int sem_destroy (sem_t *__sem) __THROW __nonnull ((1));

/* Open a named semaphore NAME with open flags OFLAG.  */
extern sem_t *sem_open (const char *__name, int __oflag, ...)
  __THROW __nonnull ((1));

/* Close descriptor for named semaphore SEM.  */
extern int sem_close (sem_t *__sem) __THROW __nonnull ((1));

/* Remove named semaphore NAME.  */
extern int sem_unlink (const char *__name) __THROW __nonnull ((1));

/* Wait for SEM being posted.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int sem_wait (sem_t *__sem) __nonnull ((1));

#ifdef __USE_XOPEN2K
/* Similar to `sem_wait' but wait only until ABSTIME.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int sem_timedwait (sem_t *__restrict __sem,
			  const struct timespec *__restrict __abstime)
  __nonnull ((1, 2));
#endif

#ifdef __USE_GNU
extern int sem_clockwait (sem_t *__restrict __sem,
			  clockid_t clock,
			  const struct timespec *__restrict __abstime)
  __nonnull ((1, 3));
#endif

/* Test whether SEM is posted.  */
extern int sem_trywait (sem_t *__sem) __THROWNL __nonnull ((1));

/* Post SEM.  */
extern int sem_post (sem_t *__sem) __THROWNL __nonnull ((1));

/* Get current value of SEM and store it in *SVAL.  */
extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
  __THROW __nonnull ((1, 2));


__END_DECLS

#endif	/* semaphore.h */