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1 | #ifndef _URCU_POINTER_H |
2 | #define _URCU_POINTER_H | |
3 | ||
4 | /* | |
5 | * urcu-pointer.h | |
6 | * | |
7 | * Userspace RCU header. Operations on pointers. | |
8 | * | |
9 | * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | |
10 | * Copyright (c) 2009 Paul E. McKenney, IBM Corporation. | |
11 | * | |
12 | * This library is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU Lesser General Public | |
14 | * License as published by the Free Software Foundation; either | |
15 | * version 2.1 of the License, or (at your option) any later version. | |
16 | * | |
17 | * This library is distributed in the hope that it will be useful, | |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * Lesser General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU Lesser General Public | |
23 | * License along with this library; if not, write to the Free Software | |
24 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
25 | * | |
26 | * IBM's contributions to this file may be relicensed under LGPLv2 or later. | |
27 | */ | |
28 | ||
29 | #include <urcu/compiler.h> | |
30 | #include <urcu/arch.h> | |
31 | #include <urcu/arch_uatomic.h> | |
32 | ||
33 | #ifdef _LGPL_SOURCE | |
34 | ||
35 | #include <urcu-pointer-static.h> | |
36 | ||
37 | /* | |
38 | * rcu_dereference(ptr) | |
39 | * | |
40 | * Fetch a RCU-protected pointer. Typically used to copy the variable ptr to a | |
41 | * local variable. | |
42 | */ | |
43 | #define rcu_dereference _rcu_dereference | |
44 | ||
45 | /* | |
46 | * rcu_cmpxchg_pointer(type **ptr, type *new, type *old) | |
47 | * type *rcu_xchg_pointer(type **ptr, type *new) | |
48 | * type *rcu_set_pointer(type **ptr, type *new) | |
49 | * | |
50 | * RCU pointer updates. | |
51 | * @ptr: address of the pointer to modify | |
52 | * @new: new pointer value | |
53 | * @old: old pointer value (expected) | |
54 | * | |
55 | * return: old pointer value | |
56 | */ | |
57 | #define rcu_cmpxchg_pointer _rcu_cmpxchg_pointer | |
58 | #define rcu_xchg_pointer _rcu_xchg_pointer | |
59 | #define rcu_set_pointer _rcu_set_pointer | |
60 | ||
61 | /* | |
62 | * type *rcu_publish_content(type **ptr, type *new) | |
63 | * | |
64 | * Exchanges the pointer and waits for quiescent state. The pointer returned | |
65 | * can be freed. You are encouraged to use either | |
66 | * - rcu_cmpxchg_pointer | |
67 | * - rcu_xchg_pointer | |
68 | * - rcu_set_pointer | |
69 | * with call_rcu(free, ptr) instead to deal with reclamation more efficiently. | |
70 | */ | |
71 | #define rcu_publish_content _rcu_publish_content | |
72 | ||
73 | #else /* !_LGPL_SOURCE */ | |
74 | ||
75 | extern void *rcu_dereference(void *p); | |
76 | ||
77 | extern void *rcu_cmpxchg_pointer_sym(void **p, void *old, void *_new); | |
78 | #define rcu_cmpxchg_pointer(p, old, _new) \ | |
79 | rcu_cmpxchg_pointer_sym((void **)(p), (old), (_new)) | |
80 | ||
81 | extern void *rcu_xchg_pointer_sym(void **p, void *v); | |
82 | #define rcu_xchg_pointer(p, v) \ | |
83 | rcu_xchg_pointer_sym((void **)(p), (v)) | |
84 | ||
85 | extern void *rcu_set_pointer_sym(void **p, void *v); | |
86 | #define rcu_set_pointer(p, v) \ | |
87 | rcu_set_pointer_sym((void **)(p), (v)) | |
88 | ||
89 | extern void *rcu_publish_content_sym(void **p, void *v); | |
90 | #define rcu_publish_content(p, v) \ | |
91 | rcu_publish_content_sym((void **)(p), (v)) | |
92 | ||
93 | extern void *rcu_assign_pointer_sym(void **p, void *v); | |
94 | ||
95 | #endif /* !_LGPL_SOURCE */ | |
96 | ||
97 | /* | |
98 | * rcu_assign_pointer(type *ptr, type *new) | |
99 | * | |
100 | * Same as rcu_set_pointer, but takes the pointer to assign to rather than its | |
101 | * address as first parameter. Provided for compatibility with the Linux kernel | |
102 | * RCU semantic. | |
103 | */ | |
104 | #define rcu_assign_pointer(p, v) rcu_set_pointer((&p), (v)) | |
105 | ||
106 | #endif /* _URCU_POINTER_H */ |