1 | /* Machine-specific definition for spin locks. Stub version. |
2 | Copyright (C) 1994-2024 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 | <https://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 | |
24 | typedef 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 void __spin_unlock (__spin_lock_t *__lock); |
38 | |
39 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
40 | _EXTERN_INLINE void |
41 | __spin_unlock (__spin_lock_t *__lock) |
42 | { |
43 | *__lock = 0; |
44 | } |
45 | #endif |
46 | |
47 | /* Try to lock LOCK; return nonzero if we locked it, zero if another has. */ |
48 | |
49 | extern int __spin_try_lock (__spin_lock_t *__lock); |
50 | |
51 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
52 | _EXTERN_INLINE int |
53 | __spin_try_lock (__spin_lock_t *__lock) |
54 | { |
55 | if (*__lock) |
56 | return 0; |
57 | *__lock = 1; |
58 | return 1; |
59 | } |
60 | #endif |
61 | |
62 | /* Return nonzero if LOCK is locked. */ |
63 | |
64 | extern int __spin_lock_locked (__spin_lock_t *__lock); |
65 | |
66 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
67 | _EXTERN_INLINE int |
68 | __spin_lock_locked (__spin_lock_t *__lock) |
69 | { |
70 | return *__lock != 0; |
71 | } |
72 | #endif |
73 | |
74 | |
75 | #endif /* machine-lock.h */ |
76 | |