user/pthread/semaphore.h

/* Copyright (C) 2002, 2003 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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#pragma once

#include <sys/queue.h>
#include <pthread.h>
#include <parlib/mcs.h>
#include <benchutil/alarm.h>

__BEGIN_DECLS

/* Value returned if `sem_open' failed.  */
#define SEM_FAILED      ((sem_t *) 0)

struct sem_queue_element {
	TAILQ_ENTRY(sem_queue_element) next;
	struct sem *sem;
	pthread_t pthread;
	uint64_t us_timeout;
	struct alarm_waiter awaiter;
	bool timedout;
};
TAILQ_HEAD(sem_qe_queue, sem_queue_element);

typedef struct sem
{
	unsigned int count;
	struct sem_qe_queue queue;
	struct spin_pdr_lock lock;
} sem_t;

extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value);
extern int sem_destroy (sem_t *__sem);
extern sem_t *sem_open (__const char *__name, int __oflag, ...);
extern int sem_close (sem_t *__sem);
extern int sem_unlink (__const char *__name);
extern int sem_wait (sem_t *__sem);
extern int sem_timedwait(sem_t *sem, const struct timespec *abs_timeout);
extern int sem_trywait (sem_t *__sem);
extern int sem_post (sem_t *__sem);
extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval);

__END_DECLS