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00131368 MD |
1 | #ifndef URCU_RBTREE_H |
2 | #define URCU_RBTREE_H | |
3 | ||
4 | /* | |
5 | * urcu-rbtree.h | |
6 | * | |
7 | * Userspace RCU library - Red-Black Tree | |
8 | * | |
9 | * Copyright (c) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
10 | * | |
11 | * This library is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU Lesser General Public | |
13 | * License as published by the Free Software Foundation; either | |
14 | * version 2.1 of the License, or (at your option) any later version. | |
15 | * | |
16 | * This library is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * Lesser General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU Lesser General Public | |
22 | * License along with this library; if not, write to the Free Software | |
23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
24 | * | |
25 | * Implementation of RCU-adapted data structures and operations based on the RB | |
26 | * tree algorithms found in chapter 12 of: | |
27 | * | |
28 | * Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and | |
29 | * Clifford Stein. Introduction to Algorithms, Third Edition. The MIT | |
30 | * Press, September 2009. | |
31 | */ | |
32 | ||
33 | #include <pthread.h> | |
34 | ||
35 | #define COLOR_BLACK 0 | |
36 | #define COLOR_RED 1 | |
37 | ||
38 | /* | |
39 | * Node key comparison function. | |
40 | * < 0 : a lower than b. | |
41 | * > 0 : a greater than b. | |
42 | * == 0 : a equals b. | |
43 | */ | |
44 | typedef int (*rcu_rbtree_comp)(void *a, void *b); | |
45 | ||
46 | /* | |
47 | * Node allocation and deletion functions. | |
48 | */ | |
49 | typedef struct rcu_rbtree_node *(*rcu_rbtree_alloc)(void); | |
50 | typedef void (*rcu_rbtree_free)(struct rcu_rbtree_node *node); | |
51 | ||
52 | struct rcu_rbtree_node; | |
53 | ||
54 | struct rcu_rbtree_node { | |
55 | /* must be set upon insertion */ | |
56 | void *key; | |
57 | ||
58 | /* internally reserved */ | |
59 | struct rcu_rbtree_node *p, *left, *right; | |
60 | unsigned int color:1; | |
61 | }; | |
62 | ||
db5b1669 MD |
63 | /* nil rbtree node. "root" must initially point to this node. */ |
64 | struct rcu_rbtree_node rcu_rbtree_nil; | |
65 | ||
00131368 MD |
66 | /* |
67 | * Each of the search primitive and "prev"/"next" iteration must be called with | |
68 | * the RCU read-side lock held. | |
69 | * | |
70 | * Insertion and removal must be protected by a mutex. At the moment, insertion | |
71 | * and removal use defer_rcu, so calling them with rcu read-lock held is | |
72 | * prohibited. | |
73 | */ | |
74 | ||
75 | /* | |
76 | * Node insertion. Returns 0 on success. May fail with -ENOMEM. | |
77 | */ | |
78 | int rcu_rbtree_insert(struct rcu_rbtree_node **root, | |
79 | struct rcu_rbtree_node *node, | |
80 | rcu_rbtree_comp comp, | |
81 | rcu_rbtree_alloc rballoc, | |
82 | rcu_rbtree_free rbfree); | |
83 | ||
84 | /* | |
85 | * Remove node from tree. | |
86 | * Must wait for a grace period after removal before performing deletion of the | |
3bc7f395 MD |
87 | * node. Note: it is illegal to re-use the same node pointer passed to "insert" |
88 | * also to "remove", because it may have been copied and garbage-collected since | |
89 | * the insertion. A "search" for the key in the tree should be done to get | |
90 | * "node". | |
00131368 | 91 | * Returns 0 on success. May fail with -ENOMEM. |
3bc7f395 MD |
92 | * |
93 | * The caller is responsible for freeing the node after a grace period. | |
00131368 MD |
94 | */ |
95 | int rcu_rbtree_remove(struct rcu_rbtree_node **root, | |
96 | struct rcu_rbtree_node *node, | |
97 | rcu_rbtree_comp comp, | |
98 | rcu_rbtree_alloc rballoc, | |
99 | rcu_rbtree_free rbfree); | |
100 | ||
101 | /* RCU read-side */ | |
102 | ||
103 | /* | |
104 | * Search key starting from node x. Returns NULL if not found. | |
105 | */ | |
106 | struct rcu_rbtree_node* rcu_rbtree_search(struct rcu_rbtree_node *x, | |
107 | void *key, rcu_rbtree_comp comp); | |
108 | ||
109 | struct rcu_rbtree_node *rcu_rbtree_min(struct rcu_rbtree_node *x, | |
110 | rcu_rbtree_comp comp); | |
111 | ||
112 | struct rcu_rbtree_node *rcu_rbtree_max(struct rcu_rbtree_node *x, | |
113 | rcu_rbtree_comp comp); | |
114 | ||
115 | struct rcu_rbtree_node *rcu_rbtree_next(struct rcu_rbtree_node *x, | |
116 | rcu_rbtree_comp comp); | |
117 | ||
118 | struct rcu_rbtree_node *rcu_rbtree_prev(struct rcu_rbtree_node *x, | |
119 | rcu_rbtree_comp comp); | |
120 | ||
121 | #endif /* URCU_RBTREE_H */ |