rename min_alloc_size/min_alloc_order
[urcu.git] / urcu / rculfhash.h
CommitLineData
a42cc659
MD
1#ifndef _URCU_RCULFHASH_H
2#define _URCU_RCULFHASH_H
ab7d5fc6 3
f0c29ed7
MD
4/*
5 * urcu/rculfhash.h
6 *
7 * Userspace RCU library - Lock-Free RCU Hash Table
8 *
9 * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
0dcf4847 10 * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
f0c29ed7
MD
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
cf77d1fa
MD
25 *
26 * Include this file _after_ including your URCU flavor.
f0c29ed7
MD
27 */
28
674f7a69 29#include <stdint.h>
6d320126 30#include <urcu/compiler.h>
abc490a1
MD
31#include <urcu-call-rcu.h>
32
01389791
MD
33#ifdef __cplusplus
34extern "C" {
35#endif
36
7f52427b 37/*
04db56f8 38 * cds_lfht_node: Contains the next pointers and reverse-hash
7f52427b 39 * value required for lookup and traversal of the hash table.
04db56f8
LJ
40 *
41 * struct cds_lfht_node should be aligned on 4-bytes boundaries because
42 * the two lower bits are used as flags.
7f52427b 43 *
ae62aa6a
MD
44 * struct cds_lfht_node can be embedded into a structure (as a field).
45 * caa_container_of() can be used to get the structure from the struct
46 * cds_lfht_node after a lookup.
04db56f8
LJ
47 *
48 * The structure which embeds it typically holds the key (or key-value
49 * pair) of the object. The caller code is responsible for calculation
50 * of the hash value for cds_lfht APIs.
ae62aa6a 51 */
14044b37 52struct cds_lfht_node {
1ee8f000 53 struct cds_lfht_node *next; /* ptr | BUCKET_FLAG | REMOVED_FLAG */
04db56f8
LJ
54 unsigned long reverse_hash;
55} __attribute__((aligned(4)));
abc490a1 56
7f52427b 57/* cds_lfht_iter: Used to track state while traversing a hash chain. */
adc0de68
MD
58struct cds_lfht_iter {
59 struct cds_lfht_node *node, *next;
60};
61
62static inline
63struct cds_lfht_node *cds_lfht_iter_get_node(struct cds_lfht_iter *iter)
64{
65 return iter->node;
66}
67
14044b37 68struct cds_lfht;
ab7d5fc6 69
5e28c532
MD
70/*
71 * Caution !
abc490a1 72 * Ensure reader and writer threads are registered as urcu readers.
5e28c532
MD
73 */
74
996ff57c 75typedef int (*cds_lfht_match_fct)(struct cds_lfht_node *node, const void *key);
abc490a1 76
f0c29ed7 77/*
14044b37 78 * cds_lfht_node_init - initialize a hash table node
0422d92c 79 * @node: the node to initialize.
04db56f8
LJ
80 *
81 * This function is kept to be eventually used for debugging purposes
82 * (detection of memory corruption).
f0c29ed7 83 */
abc490a1 84static inline
04db56f8 85void cds_lfht_node_init(struct cds_lfht_node *node)
abc490a1 86{
abc490a1 87}
674f7a69 88
b8af5011
MD
89/*
90 * Hash table creation flags.
91 */
92enum {
93 CDS_LFHT_AUTO_RESIZE = (1U << 0),
5afadd12 94 CDS_LFHT_ACCOUNTING = (1U << 1),
b8af5011
MD
95};
96
674f7a69 97/*
7a9dcf9b 98 * _cds_lfht_new - API used by cds_lfht_new wrapper. Do not use directly.
674f7a69 99 */
0422d92c 100struct cds_lfht *_cds_lfht_new(unsigned long init_size,
0722081a 101 unsigned long min_nr_alloc_buckets,
b8af5011 102 int flags,
14044b37 103 void (*cds_lfht_call_rcu)(struct rcu_head *head,
1475579c 104 void (*func)(struct rcu_head *head)),
01dbfa62
MD
105 void (*cds_lfht_synchronize_rcu)(void),
106 void (*cds_lfht_rcu_read_lock)(void),
5f511391
MD
107 void (*cds_lfht_rcu_read_unlock)(void),
108 void (*cds_lfht_rcu_thread_offline)(void),
b7d619b0
MD
109 void (*cds_lfht_rcu_thread_online)(void),
110 void (*cds_lfht_rcu_register_thread)(void),
111 void (*cds_lfht_rcu_unregister_thread)(void),
112 pthread_attr_t *attr);
ab7d5fc6 113
7a9dcf9b
MD
114/*
115 * cds_lfht_new - allocate a hash table.
f22dd01d 116 * @init_size: number of nodes to allocate initially. Must be power of two.
0722081a 117 * @min_nr_alloc_buckets: the smallest allocation size to use. Must be power of two.
f22dd01d
MD
118 * @flags: hash table creation flags (can be combined with bitwise or: '|').
119 * 0: no flags.
120 * CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
44bbe7fa
LJ
121 * CDS_LFHT_ACCOUNTING: count the number of node addition
122 * and removal in the table
b7d619b0 123 * @attr: optional resize worker thread attributes. NULL for default.
7a9dcf9b 124 *
7a9dcf9b
MD
125 * Return NULL on error.
126 * Note: the RCU flavor must be already included before the hash table header.
b7d619b0
MD
127 *
128 * The programmer is responsible for ensuring that resize operation has a
129 * priority equal to hash table updater threads. It should be performed by
130 * specifying the appropriate priority in the pthread "attr" argument, and,
131 * for CDS_LFHT_AUTO_RESIZE, by ensuring that call_rcu worker threads also have
132 * this priority level. Having lower priority for call_rcu and resize threads
133 * does not pose any correctness issue, but the resize operations could be
134 * starved by updates, thus leading to long hash table bucket chains.
44bbe7fa
LJ
135 * Threads calling this API are NOT required to be registered RCU read-side
136 * threads. It can be called very early.(before rcu is initialized ...etc.)
7a9dcf9b
MD
137 */
138static inline
0422d92c 139struct cds_lfht *cds_lfht_new(unsigned long init_size,
0722081a 140 unsigned long min_nr_alloc_buckets,
b7d619b0
MD
141 int flags,
142 pthread_attr_t *attr)
7a9dcf9b 143{
0722081a 144 return _cds_lfht_new(init_size, min_nr_alloc_buckets, flags,
7a9dcf9b
MD
145 call_rcu, synchronize_rcu, rcu_read_lock,
146 rcu_read_unlock, rcu_thread_offline,
b7d619b0
MD
147 rcu_thread_online, rcu_register_thread,
148 rcu_unregister_thread, attr);
7a9dcf9b
MD
149}
150
f0c29ed7 151/*
14044b37 152 * cds_lfht_destroy - destroy a hash table.
b7d619b0
MD
153 * @ht: the hash table to destroy.
154 * @attr: (output) resize worker thread attributes, as received by cds_lfht_new.
155 * The caller will typically want to free this pointer if dynamically
7f52427b
MD
156 * allocated. The attr point can be NULL if the caller does not
157 * need to be informed of the value passed to cds_lfht_new().
6878c72b
MD
158 *
159 * Return 0 on success, negative error value on error.
3df0c49c 160 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 161 */
b7d619b0 162int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
f0c29ed7
MD
163
164/*
14044b37 165 * cds_lfht_count_nodes - count the number of nodes in the hash table.
7f52427b
MD
166 * @ht: the hash table.
167 * @split_count_before: Sample the node count split-counter before traversal.
168 * @count: Traverse the hash table, count the number of nodes observed.
169 * @removed: Number of logically removed nodes observed during traversal.
170 * @split_count_after: Sample the node count split-counter after traversal.
0422d92c 171 *
f0c29ed7 172 * Call with rcu_read_lock held.
3df0c49c 173 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 174 */
14044b37 175void cds_lfht_count_nodes(struct cds_lfht *ht,
7f52427b 176 long *split_count_before,
adc0de68 177 unsigned long *count,
973e5e1b 178 unsigned long *removed,
7f52427b 179 long *split_count_after);
ab7d5fc6 180
f0c29ed7 181/*
14044b37 182 * cds_lfht_lookup - lookup a node by key.
0422d92c 183 * @ht: the hash table.
0422d92c 184 * @hash: the key hash.
6f554439
LJ
185 * @match: the key match function.
186 * @key: the current node key.
0422d92c 187 * @iter: Node, if found (output). *iter->node set to NULL if not found.
f0c29ed7 188 *
f0c29ed7 189 * Call with rcu_read_lock held.
3df0c49c 190 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 191 */
6f554439 192void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
996ff57c 193 cds_lfht_match_fct match, const void *key,
6f554439 194 struct cds_lfht_iter *iter);
ab7d5fc6 195
f0c29ed7 196/*
3883c0e5 197 * cds_lfht_next_duplicate - get the next item with same key (after a lookup).
0422d92c
MD
198 * @ht: the hash table.
199 * @match: the key match function.
04db56f8 200 * @key: the current node key.
0422d92c 201 * @iter: Node, if found (output). *iter->node set to NULL if not found.
f0c29ed7 202 *
adc0de68
MD
203 * Uses an iterator initialized by a lookup.
204 * Sets *iter-node to the following node with same key.
205 * Sets *iter->node to NULL if no following node exists with same key.
206 * RCU read-side lock must be held across cds_lfht_lookup and
207 * cds_lfht_next calls, and also between cds_lfht_next calls using the
208 * node returned by a previous cds_lfht_next.
209 * Call with rcu_read_lock held.
3df0c49c 210 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 211 */
0422d92c 212void cds_lfht_next_duplicate(struct cds_lfht *ht,
996ff57c 213 cds_lfht_match_fct match, const void *key,
04db56f8 214 struct cds_lfht_iter *iter);
4e9b9fbf
MD
215
216/*
217 * cds_lfht_first - get the first node in the table.
0422d92c
MD
218 * @ht: the hash table.
219 * @iter: First node, if exists (output). *iter->node set to NULL if not found.
4e9b9fbf
MD
220 *
221 * Output in "*iter". *iter->node set to NULL if table is empty.
222 * Call with rcu_read_lock held.
3df0c49c 223 * Threads calling this API need to be registered RCU read-side threads.
4e9b9fbf
MD
224 */
225void cds_lfht_first(struct cds_lfht *ht, struct cds_lfht_iter *iter);
226
227/*
228 * cds_lfht_next - get the next node in the table.
0422d92c
MD
229 * @ht: the hash table.
230 * @iter: Next node, if exists (output). *iter->node set to NULL if not found.
4e9b9fbf
MD
231 *
232 * Input/Output in "*iter". *iter->node set to NULL if *iter was
233 * pointing to the last table node.
234 * Call with rcu_read_lock held.
3df0c49c 235 * Threads calling this API need to be registered RCU read-side threads.
4e9b9fbf
MD
236 */
237void cds_lfht_next(struct cds_lfht *ht, struct cds_lfht_iter *iter);
ab7d5fc6 238
18117871 239/*
14044b37 240 * cds_lfht_add - add a node to the hash table.
0422d92c
MD
241 * @ht: the hash table.
242 * @hash: the key hash.
243 * @node: the node to add.
f0c29ed7 244 *
48ed1c18 245 * This function supports adding redundant keys into the table.
3df0c49c
MD
246 * Call with rcu_read_lock held.
247 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 248 */
0422d92c
MD
249void cds_lfht_add(struct cds_lfht *ht, unsigned long hash,
250 struct cds_lfht_node *node);
f0c29ed7
MD
251
252/*
14044b37 253 * cds_lfht_add_unique - add a node to hash table, if key is not present.
0422d92c 254 * @ht: the hash table.
6f554439 255 * @hash: the node's hash.
0422d92c 256 * @match: the key match function.
04db56f8 257 * @key: the node's key.
0422d92c 258 * @node: the node to try adding.
f0c29ed7 259 *
6878c72b 260 * Return the node added upon success.
860d07e8
MD
261 * Return the unique node already present upon failure. If
262 * cds_lfht_add_unique fails, the node passed as parameter should be
263 * freed by the caller.
f0c29ed7 264 * Call with rcu_read_lock held.
3df0c49c 265 * Threads calling this API need to be registered RCU read-side threads.
48ed1c18
MD
266 *
267 * The semantic of this function is that if only this function is used
268 * to add keys into the table, no duplicated keys should ever be
269 * observable in the table. The same guarantee apply for combination of
9357c415 270 * add_unique and add_replace (see below).
18117871 271 */
adc0de68 272struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
6f554439 273 unsigned long hash,
0422d92c 274 cds_lfht_match_fct match,
996ff57c 275 const void *key,
adc0de68 276 struct cds_lfht_node *node);
3eca1b8c 277
48ed1c18 278/*
9357c415 279 * cds_lfht_add_replace - replace or add a node within hash table.
0422d92c 280 * @ht: the hash table.
6f554439 281 * @hash: the node's hash.
0422d92c 282 * @match: the key match function.
04db56f8 283 * @key: the node's key.
0422d92c 284 * @node: the node to add.
48ed1c18
MD
285 *
286 * Return the node replaced upon success. If no node matching the key
287 * was present, return NULL, which also means the operation succeeded.
288 * This replacement operation should never fail.
289 * Call with rcu_read_lock held.
3df0c49c 290 * Threads calling this API need to be registered RCU read-side threads.
48ed1c18
MD
291 * After successful replacement, a grace period must be waited for before
292 * freeing the memory reserved for the returned node.
293 *
294 * The semantic of replacement vs lookups is the following: if lookups
9357c415
MD
295 * are performed between a key unique insertion and its removal, we
296 * guarantee that the lookups and get next will always find exactly one
297 * instance of the key if it is replaced concurrently with the lookups.
48ed1c18
MD
298 *
299 * Providing this semantic allows us to ensure that replacement-only
300 * schemes will never generate duplicated keys. It also allows us to
9357c415 301 * guarantee that a combination of add_replace and add_unique updates
48ed1c18
MD
302 * will never generate duplicated keys.
303 */
9357c415 304struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
6f554439 305 unsigned long hash,
0422d92c 306 cds_lfht_match_fct match,
996ff57c 307 const void *key,
adc0de68 308 struct cds_lfht_node *node);
48ed1c18 309
f0c29ed7 310/*
9357c415 311 * cds_lfht_replace - replace a node pointer to by iter within hash table.
0422d92c
MD
312 * @ht: the hash table.
313 * @old_iter: the iterator position of the node to replace.
314 * @now_node: the new node to try using for replacement.
f0c29ed7 315 *
9357c415
MD
316 * Return 0 if replacement is successful, negative value otherwise.
317 * Replacing a NULL old node or an already removed node will fail with a
318 * negative value.
319 * Old node can be looked up with cds_lfht_lookup and cds_lfht_next.
320 * RCU read-side lock must be held between lookup and replacement.
321 * Call with rcu_read_lock held.
3df0c49c 322 * Threads calling this API need to be registered RCU read-side threads.
9357c415
MD
323 * After successful replacement, a grace period must be waited for before
324 * freeing the memory reserved for the old node (which can be accessed
325 * with cds_lfht_iter_get_node).
326 *
327 * The semantic of replacement vs lookups is the following: if lookups
328 * are performed between a key unique insertion and its removal, we
329 * guarantee that the lookups and get next will always find exactly one
330 * instance of the key if it is replaced concurrently with the lookups.
331 *
332 * Providing this semantic allows us to ensure that replacement-only
333 * schemes will never generate duplicated keys. It also allows us to
334 * guarantee that a combination of add_replace and add_unique updates
335 * will never generate duplicated keys.
336 */
337int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
338 struct cds_lfht_node *new_node);
339
340/*
341 * cds_lfht_del - remove node pointed to by iterator from hash table.
0422d92c
MD
342 * @ht: the hash table.
343 * @iter: the iterator position of the node to delete.
9357c415
MD
344 *
345 * Return 0 if the node is successfully removed, negative value
346 * otherwise.
347 * Replacing a NULL node or an already removed node will fail with a
348 * negative value.
349 * Node can be looked up with cds_lfht_lookup and cds_lfht_next.
350 * cds_lfht_iter_get_node.
351 * RCU read-side lock must be held between lookup and removal.
f0c29ed7 352 * Call with rcu_read_lock held.
3df0c49c 353 * Threads calling this API need to be registered RCU read-side threads.
48ed1c18 354 * After successful removal, a grace period must be waited for before
9357c415
MD
355 * freeing the memory reserved for old node (which can be accessed with
356 * cds_lfht_iter_get_node).
f0c29ed7 357 */
9357c415 358int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter);
ab7d5fc6 359
f0c29ed7 360/*
14044b37 361 * cds_lfht_resize - Force a hash table resize
0422d92c 362 * @ht: the hash table.
1475579c 363 * @new_size: update to this hash table size.
3df0c49c
MD
364 *
365 * Threads calling this API need to be registered RCU read-side threads.
f0c29ed7 366 */
1475579c 367void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
464a1ec9 368
6d320126
MD
369/*
370 * Note: cds_lfht_for_each are safe for element removal during
371 * iteration.
372 */
373#define cds_lfht_for_each(ht, iter, node) \
374 for (cds_lfht_first(ht, iter), \
375 node = cds_lfht_iter_get_node(iter); \
376 node != NULL; \
377 cds_lfht_next(ht, iter), \
378 node = cds_lfht_iter_get_node(iter))
379
6f554439
LJ
380#define cds_lfht_for_each_duplicate(ht, hash, match, key, iter, node) \
381 for (cds_lfht_lookup(ht, hash, match, key, iter), \
6d320126
MD
382 node = cds_lfht_iter_get_node(iter); \
383 node != NULL; \
384 cds_lfht_next_duplicate(ht, match, key, iter), \
385 node = cds_lfht_iter_get_node(iter))
386
387#define cds_lfht_for_each_entry(ht, iter, pos, member) \
388 for (cds_lfht_first(ht, iter), \
389 pos = caa_container_of(cds_lfht_iter_get_node(iter), \
390 typeof(*(pos)), member); \
0b0627bf 391 &(pos)->member != NULL; \
6d320126
MD
392 cds_lfht_next(ht, iter), \
393 pos = caa_container_of(cds_lfht_iter_get_node(iter), \
394 typeof(*(pos)), member))
395
6f554439 396#define cds_lfht_for_each_entry_duplicate(ht, hash, match, key, \
6d320126 397 iter, pos, member) \
6f554439 398 for (cds_lfht_lookup(ht, hash, match, key, iter), \
6d320126
MD
399 pos = caa_container_of(cds_lfht_iter_get_node(iter), \
400 typeof(*(pos)), member); \
0b0627bf 401 &(pos)->member != NULL; \
6d320126
MD
402 cds_lfht_next_duplicate(ht, match, key, iter), \
403 pos = caa_container_of(cds_lfht_iter_get_node(iter), \
404 typeof(*(pos)), member))
405
01389791
MD
406#ifdef __cplusplus
407}
408#endif
409
a42cc659 410#endif /* _URCU_RCULFHASH_H */
This page took 0.067213 seconds and 4 git commands to generate.