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lh9ed821d2023-04-07 01:36:19 -07001/* Machine-specific definition for spin locks. Stub version.
2 Copyright (C) 1994-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _MACHINE_LOCK_H
20#define _MACHINE_LOCK_H
21
22/* The type of a spin lock variable. */
23
24typedef volatile int __spin_lock_t;
25
26/* Value to initialize `__spin_lock_t' variables to. */
27
28#define __SPIN_LOCK_INITIALIZER 0
29
30
31#ifndef _EXTERN_INLINE
32#define _EXTERN_INLINE __extern_inline
33#endif
34
35/* Unlock LOCK. */
36
37_EXTERN_INLINE void
38__spin_unlock (__spin_lock_t *__lock)
39{
40 *__lock = 0;
41}
42
43/* Try to lock LOCK; return nonzero if we locked it, zero if another has. */
44
45_EXTERN_INLINE int
46__spin_try_lock (__spin_lock_t *__lock)
47{
48 if (*__lock)
49 return 0;
50 *__lock = 1;
51 return 1;
52}
53
54/* Return nonzero if LOCK is locked. */
55
56_EXTERN_INLINE int
57__spin_lock_locked (__spin_lock_t *__lock)
58{
59 return *__lock != 0;
60}
61
62
63#endif /* machine-lock.h */