/*	$NetBSD: mutex.h,v 1.6 2020/05/25 20:47:22 christos Exp $	*/

/*
 * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* Id: mutex.h,v 1.6 2007/06/19 23:47:18 tbox Exp  */

#ifndef ISC_MUTEX_H
#define ISC_MUTEX_H 1

#include <isc/result.h>		/* for ISC_R_ codes */

typedef int isc_mutex_t;

#define isc_mutex_init(mp) \
	(*(mp) = 0, ISC_R_SUCCESS)
#define isc_mutex_lock(mp) \
	((*(mp))++ == 0 ? ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#define isc_mutex_unlock(mp) \
	(--(*(mp)) == 0 ? ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#define isc_mutex_trylock(mp) \
	(*(mp) == 0 ? ((*(mp))++, ISC_R_SUCCESS) : ISC_R_LOCKBUSY)
#define isc_mutex_destroy(mp) \
	(*(mp) == 0 ? (*(mp) = -1, ISC_R_SUCCESS) : ISC_R_UNEXPECTED)
#define isc_mutex_stats(fp)

#endif /* ISC_MUTEX_H */