mutex.h revision 290001 
1/*
2 * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: mutex.h,v 1.6 2007/06/19 23:47:18 tbox Exp $ */
19
20#ifndef ISC_MUTEX_H
21#define ISC_MUTEX_H 1
22
23#include <isc/result.h>		/* for ISC_R_ codes */
24
25typedef int isc_mutex_t;
26
27#define isc_mutex_init(mp) \
28	(*(mp) = 0, ISC_R_SUCCESS)
29#define isc_mutex_lock(mp) \
30	((*(mp))++ == 0 ? ISC_R_SUCCESS : ISC_R_UNEXPECTED)
31#define isc_mutex_unlock(mp) \
32	(--(*(mp)) == 0 ? ISC_R_SUCCESS : ISC_R_UNEXPECTED)
33#define isc_mutex_trylock(mp) \
34	(*(mp) == 0 ? ((*(mp))++, ISC_R_SUCCESS) : ISC_R_LOCKBUSY)
35#define isc_mutex_destroy(mp) \
36	(*(mp) == 0 ? (*(mp) = -1, ISC_R_SUCCESS) : ISC_R_UNEXPECTED)
37#define isc_mutex_stats(fp)
38
39#endif /* ISC_MUTEX_H */
40