1 | /* Copyright (C) 1994-2022 Free Software Foundation, Inc. |
---|---|
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #ifndef _LOCK_INTERN_H |
19 | #define _LOCK_INTERN_H |
20 | |
21 | #include <sys/cdefs.h> |
22 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
23 | # include <lowlevellock.h> |
24 | #endif |
25 | |
26 | #ifndef _EXTERN_INLINE |
27 | #define _EXTERN_INLINE __extern_inline |
28 | #endif |
29 | |
30 | /* The type of a spin lock variable. */ |
31 | typedef unsigned int __spin_lock_t; |
32 | |
33 | /* Static initializer for spinlocks. */ |
34 | #define __SPIN_LOCK_INITIALIZER LLL_LOCK_INITIALIZER |
35 | |
36 | /* Initialize LOCK. */ |
37 | |
38 | extern void __spin_lock_init (__spin_lock_t *__lock); |
39 | |
40 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
41 | _EXTERN_INLINE void |
42 | __spin_lock_init (__spin_lock_t *__lock) |
43 | { |
44 | *__lock = __SPIN_LOCK_INITIALIZER; |
45 | } |
46 | #endif |
47 | |
48 | |
49 | /* Lock LOCK, blocking if we can't get it. */ |
50 | extern void __spin_lock_solid (__spin_lock_t *__lock); |
51 | |
52 | /* Lock the spin lock LOCK. */ |
53 | |
54 | extern void __spin_lock (__spin_lock_t *__lock); |
55 | |
56 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
57 | _EXTERN_INLINE void |
58 | __spin_lock (__spin_lock_t *__lock) |
59 | { |
60 | __lll_lock (__lock, 0); |
61 | } |
62 | #endif |
63 | |
64 | /* Unlock LOCK. */ |
65 | extern void __spin_unlock (__spin_lock_t *__lock); |
66 | |
67 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
68 | _EXTERN_INLINE void |
69 | __spin_unlock (__spin_lock_t *__lock) |
70 | { |
71 | __lll_unlock (__lock, 0); |
72 | } |
73 | #endif |
74 | |
75 | /* Try to lock LOCK; return nonzero if we locked it, zero if another has. */ |
76 | extern int __spin_try_lock (__spin_lock_t *__lock); |
77 | |
78 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
79 | _EXTERN_INLINE int |
80 | __spin_try_lock (__spin_lock_t *__lock) |
81 | { |
82 | return (__lll_trylock (__lock) == 0); |
83 | } |
84 | #endif |
85 | |
86 | /* Return nonzero if LOCK is locked. */ |
87 | extern int __spin_lock_locked (__spin_lock_t *__lock); |
88 | |
89 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
90 | _EXTERN_INLINE int |
91 | __spin_lock_locked (__spin_lock_t *__lock) |
92 | { |
93 | return (*(volatile __spin_lock_t *)__lock != 0); |
94 | } |
95 | #endif |
96 | |
97 | /* Name space-clean internal interface to mutex locks. */ |
98 | struct mutex { |
99 | __spin_lock_t __held; |
100 | __spin_lock_t __lock; |
101 | const char *__name; |
102 | void *__head, *__tail; |
103 | void *__holder; |
104 | }; |
105 | |
106 | #define MUTEX_INITIALIZER { __SPIN_LOCK_INITIALIZER } |
107 | |
108 | /* Initialize the newly allocated mutex lock LOCK for further use. */ |
109 | extern void __mutex_init (void *__lock); |
110 | |
111 | /* Lock the mutex lock LOCK. */ |
112 | |
113 | extern void __mutex_lock (void *__lock); |
114 | |
115 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
116 | _EXTERN_INLINE void |
117 | __mutex_lock (void *__lock) |
118 | { |
119 | __spin_lock (lock: (__spin_lock_t *)__lock); |
120 | } |
121 | #endif |
122 | |
123 | /* Unlock the mutex lock LOCK. */ |
124 | |
125 | extern void __mutex_unlock (void *__lock); |
126 | |
127 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
128 | _EXTERN_INLINE void |
129 | __mutex_unlock (void *__lock) |
130 | { |
131 | __spin_unlock (lock: (__spin_lock_t *)__lock); |
132 | } |
133 | #endif |
134 | |
135 | |
136 | extern int __mutex_trylock (void *__lock); |
137 | |
138 | #if defined __USE_EXTERN_INLINES && defined _LIBC |
139 | _EXTERN_INLINE int |
140 | __mutex_trylock (void *__lock) |
141 | { |
142 | return (__spin_try_lock (lock: (__spin_lock_t *)__lock)); |
143 | } |
144 | #endif |
145 | |
146 | #endif /* lock-intern.h */ |
147 |