2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $DragonFly: src/lib/libthread_xu/thread/thr_umtx.h,v 1.5 2008/04/14 20:12:41 dillon Exp $
27 * $DragonFly: src/lib/libsysvipc/lock_generic.h,v 1 2013/09/20 Larisa Grigore<lariisagrigore@gmail.com>
30 #ifndef _SYSV_DFLY_UMTX_H_
31 #define _SYSV_DFLY_UMTX_H_
34 #include <machine/atomic.h>
36 #define SYSV_TIMEOUT 4000
40 int __sysv_umtx_lock(volatile umtx_t *mtx, int timo);
41 void __sysv_umtx_unlock(volatile umtx_t *mtx);
44 _sysv_umtx_init(volatile umtx_t *mtx)
50 _sysv_umtx_lock(volatile umtx_t *mtx)
52 if (atomic_cmpset_acq_int(mtx, 0, 1))
54 return (__sysv_umtx_lock(mtx, 0));
58 _sysv_umtx_unlock(volatile umtx_t *mtx)
60 if (atomic_cmpset_acq_int(mtx, 1, 0))
62 __sysv_umtx_unlock(mtx);