1 /*-
2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #ifndef _SYSVIPC_LOCK_GENERIC_H_
28 #define _SYSVIPC_LOCK_GENERIC_H_
29
30 #include <unistd.h>
31 #include <machine/atomic.h>
32
33 #define SYSV_TIMEOUT 4000
34
35 typedef int umtx_t;
36
37 int __sysv_umtx_lock(volatile umtx_t *mtx, int timo);
38 void __sysv_umtx_unlock(volatile umtx_t *mtx);
39
40 static inline void
_sysv_umtx_init(volatile umtx_t * mtx)41 _sysv_umtx_init(volatile umtx_t *mtx)
42 {
43 *mtx = 0;
44 }
45
46 static inline int
_sysv_umtx_lock(volatile umtx_t * mtx)47 _sysv_umtx_lock(volatile umtx_t *mtx)
48 {
49 if (atomic_cmpset_acq_int(mtx, 0, 1))
50 return (0);
51 return (__sysv_umtx_lock(mtx, 0));
52 }
53
54 static inline void
_sysv_umtx_unlock(volatile umtx_t * mtx)55 _sysv_umtx_unlock(volatile umtx_t *mtx)
56 {
57 if (atomic_cmpset_acq_int(mtx, 1, 0))
58 return;
59 __sysv_umtx_unlock(mtx);
60 }
61
62 #endif /* !_SYSVIPC_LOCK_GENERIC_H_ */
63