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/*
* Authors: Martin Nagy <mnagy@redhat.com>
*
* Copyright (C) 2008 Red Hat
* see file 'COPYING' for use and warranty information
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; version 2 or later
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _LD_SEMAPHORE_H_
#define _LD_SEMAPHORE_H_
#include <isc/condition.h>
#include <isc/mutex.h>
/*
* Semaphore can be "acquired" multiple times. However, it has a maximum
* number of times someone can acquire him. If a semaphore is already acquired
* more times than allowed, it will block until other thread release its,
*/
struct semaphore {
int value; /* Maximum number of times you can LOCK()) */
isc_mutex_t mutex; /* Mutex protecting this whole struct. */
isc_condition_t cond; /* Condition used for waiting on release. */
};
typedef struct semaphore semaphore_t;
/* Public functions. */
isc_result_t semaphore_init(semaphore_t *sem, int value);
void semaphore_destroy(semaphore_t *sem);
void semaphore_wait(semaphore_t *sem);
void semaphore_signal(semaphore_t *sem);
#endif /* !_LD_SEMAPHORE_H_ */
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