sema.h

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/*
 * Copyright (C) 2016 TriaGnoSys GmbH
 *               2015 Martine Lenders <mlenders@inf.fu-berlin.de>
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

#ifndef SEMA_H
#define SEMA_H

#include <stdint.h>

#include "mutex.h"

#ifdef __cplusplus
extern "C" {
#endif

#define SEMA_CREATE(value)         { (value), SEMA_OK, MUTEX_INIT }

#define SEMA_CREATE_LOCKED()        { (0), SEMA_OK, MUTEX_INIT_LOCKED }

typedef enum {
    SEMA_OK = 0,
    SEMA_DESTROY,
} sema_state_t;

typedef struct {
    unsigned int value;             
    sema_state_t state;             
    mutex_t mutex;                  
} sema_t;

void sema_create(sema_t *sema, unsigned int value);

void sema_destroy(sema_t *sema);

static inline unsigned sema_get_value(const sema_t *sema)
{
    return sema->value;
}

int _sema_wait(sema_t *sema, int block, uint64_t timeout);

static inline int sema_wait_timed(sema_t *sema, uint64_t timeout)
{
    return _sema_wait(sema, (timeout != 0), timeout);
}

static inline int sema_wait(sema_t *sema)
{
    return _sema_wait(sema, 1, 0);
}

static inline int sema_try_wait(sema_t *sema)
{
    return _sema_wait(sema, 0, 0);
}

int sema_post(sema_t *sema);

#ifdef __cplusplus
}
#endif

#endif /* SEMA_H */