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7e30abe3 MD |
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 | * | |
6982d6d7 | 9 | * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7e30abe3 MD |
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> | |
a2e7bf9c | 31 | #include <urcu/uatomic.h> |
7e30abe3 | 32 | |
36bc70a8 MD |
33 | #ifdef __cplusplus |
34 | extern "C" { | |
67ecffc0 | 35 | #endif |
36bc70a8 | 36 | |
d663f489 | 37 | #if defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS) |
7e30abe3 | 38 | |
af7c2dbe | 39 | #include <urcu/static/urcu-pointer.h> |
7e30abe3 MD |
40 | |
41 | /* | |
42 | * rcu_dereference(ptr) | |
43 | * | |
44 | * Fetch a RCU-protected pointer. Typically used to copy the variable ptr to a | |
45 | * local variable. | |
46 | */ | |
47 | #define rcu_dereference _rcu_dereference | |
48 | ||
49 | /* | |
3daae22a | 50 | * type *rcu_cmpxchg_pointer(type **ptr, type *new, type *old) |
7e30abe3 | 51 | * type *rcu_xchg_pointer(type **ptr, type *new) |
3daae22a | 52 | * void rcu_set_pointer(type **ptr, type *new) |
7e30abe3 MD |
53 | * |
54 | * RCU pointer updates. | |
55 | * @ptr: address of the pointer to modify | |
56 | * @new: new pointer value | |
57 | * @old: old pointer value (expected) | |
58 | * | |
59 | * return: old pointer value | |
60 | */ | |
61 | #define rcu_cmpxchg_pointer _rcu_cmpxchg_pointer | |
62 | #define rcu_xchg_pointer _rcu_xchg_pointer | |
63 | #define rcu_set_pointer _rcu_set_pointer | |
64 | ||
d663f489 | 65 | #else /* !(defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS)) */ |
7e30abe3 | 66 | |
2ff1db4a MD |
67 | extern void *rcu_dereference_sym(void *p); |
68 | #define rcu_dereference(p) \ | |
1b85da85 | 69 | __extension__ \ |
2ff1db4a | 70 | ({ \ |
bdffa73a | 71 | __typeof__(p) _________p1 = URCU_FORCE_CAST(__typeof__(p), \ |
4501f284 | 72 | rcu_dereference_sym(URCU_FORCE_CAST(void *, p))); \ |
2ff1db4a MD |
73 | (_________p1); \ |
74 | }) | |
7e30abe3 MD |
75 | |
76 | extern void *rcu_cmpxchg_pointer_sym(void **p, void *old, void *_new); | |
2ff1db4a | 77 | #define rcu_cmpxchg_pointer(p, old, _new) \ |
1b85da85 | 78 | __extension__ \ |
2ff1db4a | 79 | ({ \ |
bdffa73a MD |
80 | __typeof__(*(p)) _________pold = (old); \ |
81 | __typeof__(*(p)) _________pnew = (_new); \ | |
82 | __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \ | |
83 | rcu_cmpxchg_pointer_sym(URCU_FORCE_CAST(void **, p), \ | |
4501f284 MD |
84 | _________pold, \ |
85 | _________pnew)); \ | |
2ff1db4a MD |
86 | (_________p1); \ |
87 | }) | |
7e30abe3 MD |
88 | |
89 | extern void *rcu_xchg_pointer_sym(void **p, void *v); | |
2ff1db4a | 90 | #define rcu_xchg_pointer(p, v) \ |
1b85da85 | 91 | __extension__ \ |
2ff1db4a | 92 | ({ \ |
bdffa73a MD |
93 | __typeof__(*(p)) _________pv = (v); \ |
94 | __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \ | |
4501f284 MD |
95 | rcu_xchg_pointer_sym(URCU_FORCE_CAST(void **, p), \ |
96 | _________pv)); \ | |
2ff1db4a MD |
97 | (_________p1); \ |
98 | }) | |
7e30abe3 | 99 | |
3daae22a MD |
100 | /* |
101 | * Note: rcu_set_pointer_sym returns @v because we don't want to break | |
102 | * the ABI. At the API level, rcu_set_pointer() now returns void. Use of | |
103 | * the return value is therefore deprecated, and will cause a build | |
104 | * error. | |
105 | */ | |
7e30abe3 | 106 | extern void *rcu_set_pointer_sym(void **p, void *v); |
2ff1db4a | 107 | #define rcu_set_pointer(p, v) \ |
3daae22a | 108 | do { \ |
bdffa73a | 109 | __typeof__(*(p)) _________pv = (v); \ |
3daae22a MD |
110 | (void) rcu_set_pointer_sym(URCU_FORCE_CAST(void **, p), \ |
111 | _________pv); \ | |
112 | } while (0) | |
7e30abe3 | 113 | |
d663f489 | 114 | #endif /* !(defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS)) */ |
7e30abe3 MD |
115 | |
116 | /* | |
3daae22a | 117 | * void rcu_assign_pointer(type *ptr, type *new) |
7e30abe3 MD |
118 | * |
119 | * Same as rcu_set_pointer, but takes the pointer to assign to rather than its | |
120 | * address as first parameter. Provided for compatibility with the Linux kernel | |
121 | * RCU semantic. | |
122 | */ | |
123 | #define rcu_assign_pointer(p, v) rcu_set_pointer((&p), (v)) | |
124 | ||
67ecffc0 | 125 | #ifdef __cplusplus |
36bc70a8 MD |
126 | } |
127 | #endif | |
128 | ||
7e30abe3 | 129 | #endif /* _URCU_POINTER_H */ |