xref: /freebsd/lib/libc/include/spinlock.h (revision ebbd4fa8c8427d3dd847ba33c45c996e0500e6ff)
1 /*
2  * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by John Birrell.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  *
34  * Lock definitions used in both libc and libpthread.
35  *
36  */
37 
38 #ifndef _SPINLOCK_H_
39 #define _SPINLOCK_H_
40 #include <sys/cdefs.h>
41 #include <sys/types.h>
42 
43 /*
44  * Lock structure with room for debugging information.
45  */
46 typedef struct {
47 	volatile long	access_lock;
48 	volatile long	lock_owner;
49 	volatile char	*fname;
50 	volatile int	lineno;
51 } spinlock_t;
52 
53 #define	_SPINLOCK_INITIALIZER	{ 0, 0, 0, 0 }
54 
55 #define _SPINUNLOCK(_lck)	(_lck)->access_lock = 0
56 #ifdef	_LOCK_DEBUG
57 #define	_SPINLOCK(_lck)		_spinlock_debug(_lck, __FILE__, __LINE__)
58 #else
59 #define	_SPINLOCK(_lck)		_spinlock(_lck)
60 #endif
61 
62 /*
63  * Thread function prototype definitions:
64  */
65 __BEGIN_DECLS
66 long	_atomic_lock(volatile long *);
67 void	_spinlock(spinlock_t *);
68 void	_spinlock_debug(spinlock_t *, char *, int);
69 __END_DECLS
70 
71 #endif /* _SPINLOCK_H_ */
72