7 * Userspace RCU library - RCU Judy Array
9 * Copyright 2012-2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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.
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.
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
25 * Include this file _after_ including your URCU flavor.
29 #include <urcu/compiler.h>
30 #include <urcu-call-rcu.h>
31 #include <urcu-flavor.h>
39 * Duplicate nodes with the same key are chained into a singly-linked
40 * list. The last item of this list has a NULL next pointer.
43 struct cds_ja_node
*next
;
49 * cds_ja_node_init - initialize a judy array node
50 * @node: the node to initialize.
52 * This function is kept to be eventually used for debugging purposes
53 * (detection of memory corruption).
56 void cds_ja_node_init(struct cds_ja_node
*node
)
61 * cds_ja_lookup - look up by key.
62 * @ja: the Judy array.
63 * @key: key to look up.
65 * Returns the first node of a duplicate chain if a match is found, else
67 * A RCU read-side lock should be held across call to this function and
68 * use of its return value.
70 struct cds_ja_node
*cds_ja_lookup(struct cds_ja
*ja
, uint64_t key
);
73 * cds_ja_lookup_below_equal - look up first node with key <= @key.
74 * @ja: the Judy array.
75 * @key: key to look up.
76 * @result_key: key found.
78 * Returns the first node of a duplicate chain if a node is present in
79 * the tree which has a key below or equal to @key, else returns NULL.
80 * A RCU read-side lock should be held across call to this function and
81 * use of its return value.
83 struct cds_ja_node
*cds_ja_lookup_below_equal(struct cds_ja
*ja
,
84 uint64_t key
, uint64_t *result_key
);
87 * cds_ja_lookup_above_equal - look up first node with key >= @key.
88 * @ja: the Judy array.
89 * @key: key to look up.
90 * @result_key: key found.
92 * Returns the first node of a duplicate chain if a node is present in
93 * the tree which has a key above or equal to @key, else returns NULL.
94 * A RCU read-side lock should be held across call to this function and
95 * use of its return value.
97 struct cds_ja_node
*cds_ja_lookup_above_equal(struct cds_ja
*ja
,
98 uint64_t key
, uint64_t *result_key
);
101 * cds_ja_add - Add @node at @key, allowing duplicates.
102 * @ja: the Judy array.
103 * @key: key at which @node should be added.
104 * @node: node to add.
106 * Returns 0 on success, negative error value on error.
107 * A RCU read-side lock should be held across call to this function.
109 int cds_ja_add(struct cds_ja
*ja
, uint64_t key
,
110 struct cds_ja_node
*node
);
113 * cds_ja_add_unique - Add @node at @key, without duplicates.
114 * @ja: the Judy array.
115 * @key: key at which @node should be added.
116 * @node: node to add.
118 * Returns @node if successfully added, else returns the already
119 * existing node (acts as a RCU lookup).
120 * A RCU read-side lock should be held across call to this function and
121 * use of its return value.
123 struct cds_ja_node
*cds_ja_add_unique(struct cds_ja
*ja
, uint64_t key
,
124 struct cds_ja_node
*node
);
127 * cds_ja_del - Remove @node at @key.
128 * @ja: the Judy array.
129 * @key: key at which @node is expected.
130 * @node: node to remove.
132 * Returns 0 on success, negative error value on error.
133 * A RCU read-side lock should be held across call to this function.
135 int cds_ja_del(struct cds_ja
*ja
, uint64_t key
,
136 struct cds_ja_node
*node
);
138 struct cds_ja
*_cds_ja_new(unsigned int key_bits
,
139 const struct rcu_flavor_struct
*flavor
);
142 * cds_ja_new - Create a Judy array.
143 * @key_bits: Number of bits for key.
145 * Returns non-NULL pointer on success, else NULL on error. @key_bits
146 * needs to be multiple of 8, either: 8, 16, 24, 32, 40, 48, 56, or 64.
149 struct cds_ja
*cds_ja_new(unsigned int key_bits
)
151 return _cds_ja_new(key_bits
, &rcu_flavor
);
155 * cds_ja_destroy - Destroy a Judy array.
156 * @ja: the Judy array.
158 * Returns 0 on success, negative error value on error.
159 * There should be no more concurrent add, delete, nor look-up performed
160 * on the Judy array while it is being destroyed (ensured by the caller).
161 * RCU read-side lock should _not_ be held when calling this function,
162 * however, QSBR threads need to be online.
164 int cds_ja_destroy(struct cds_ja
*ja
);
167 * cds_ja_for_each_duplicate_rcu: Iterate through duplicates.
168 * @pos: struct cds_ja_node *, start of duplicate list and loop cursor.
170 * Iterate through duplicates returned by cds_ja_lookup*()
171 * This must be done while rcu_read_lock() is held.
172 * Receives a struct cds_ja_node * as parameter, which is used as start
173 * of duplicate list and loop cursor.
174 * _NOT_ safe against node removal within iteration.
176 #define cds_ja_for_each_duplicate_rcu(pos) \
177 for (; (pos) != NULL; (pos) = rcu_dereference((pos)->next))
180 * cds_ja_for_each_duplicate_safe: Iterate through duplicates.
181 * @pos: struct cds_ja_node *, start of duplicate list and loop cursor.
182 * @p: struct cds_ja_node *, temporary pointer to next.
184 * Iterate through duplicates returned by cds_ja_lookup*().
185 * Safe against node removal within iteration.
186 * This must be done while rcu_read_lock() is held.
188 #define cds_ja_for_each_duplicate_safe_rcu(pos, p) \
189 for (; (pos) != NULL ? \
190 ((p) = rcu_dereference((pos)->next), 1) : 0; \
194 * cds_ja_for_each_key_rcu: Iterate over all keys in ascending order.
195 * @ja: Judy array on which iteration should be done.
196 * @key: Key cursor, needs to be a uint64_t.
197 * @pos: struct cds_ja_node *, used as loop cursor.
199 * Iterate over all keys of a RCU Judy array (_not_ duplicates) in
201 * This must be done while rcu_read_lock() is held.
202 * Safe against node removal during iteration.
204 #define cds_ja_for_each_key_rcu(ja, key, pos) \
206 ((pos) = cds_ja_lookup_above_equal(ja, key, &(key))); )
209 * cds_ja_for_each_key_prev_rcu: Iterate over all keys in descending order.
210 * @ja: Judy array on which iteration should be done.
211 * @key: Key cursor, needs to be a uint64_t.
212 * @pos: struct cds_ja_node *, used as loop cursor.
214 * Iterate over all keys of a RCU Judy array (_not_ duplicates) in
216 * This must be done while rcu_read_lock() is held.
217 * Safe against node removal during iteration.
219 #define cds_ja_for_each_key_prev_rcu(ja, key, pos) \
220 for ((key) = UINT64_MAX; \
221 ((pos) = cds_ja_lookup_below_equal(ja, key, &(key))); )
227 #endif /* _URCU_RCUJA_H */
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