Fix: consumer race: should allow reuse of FD key
[lttng-tools.git] / src / common / hashtable / hashtable.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <assert.h>
20 #include <string.h>
21 #include <urcu.h>
22 #include <urcu/compiler.h>
23
24 #include <common/common.h>
25 #include <common/defaults.h>
26
27 #include "hashtable.h"
28 #include "utils.h"
29
30 #define HASH_SEED 0x42UL /* The answer to life */
31
32 static unsigned long min_hash_alloc_size = 1;
33 static unsigned long max_hash_buckets_size = (1UL << 20);
34
35 /*
36 * Match function for string node.
37 */
38 static int match_str(struct cds_lfht_node *node, const void *key)
39 {
40 struct lttng_ht_node_str *match_node =
41 caa_container_of(node, struct lttng_ht_node_str, node);
42
43 return hash_match_key_str(match_node->key, (void *) key);
44 }
45
46 /*
47 * Match function for ulong node.
48 */
49 static int match_ulong(struct cds_lfht_node *node, const void *key)
50 {
51 struct lttng_ht_node_ulong *match_node =
52 caa_container_of(node, struct lttng_ht_node_ulong, node);
53
54 return hash_match_key_ulong((void *) match_node->key, (void *) key);
55 }
56
57 /*
58 * Return an allocated lttng hashtable.
59 */
60 struct lttng_ht *lttng_ht_new(unsigned long size, int type)
61 {
62 struct lttng_ht *ht;
63
64 /* Test size */
65 if (!size)
66 size = DEFAULT_HT_SIZE;
67
68 ht = zmalloc(sizeof(*ht));
69 if (ht == NULL) {
70 PERROR("zmalloc lttng_ht");
71 goto error;
72 }
73
74 ht->ht = cds_lfht_new(size, min_hash_alloc_size, max_hash_buckets_size,
75 CDS_LFHT_AUTO_RESIZE, NULL);
76 /*
77 * There is already an assert in the RCU hashtable code so if the ht is
78 * NULL here there is a *huge* problem.
79 */
80 assert(ht->ht);
81
82 switch (type) {
83 case LTTNG_HT_TYPE_STRING:
84 ht->match_fct = match_str;
85 ht->hash_fct = hash_key_str;
86 break;
87 case LTTNG_HT_TYPE_ULONG:
88 ht->match_fct = match_ulong;
89 ht->hash_fct = hash_key_ulong;
90 break;
91 default:
92 ERR("Unknown lttng hashtable type %d", type);
93 goto error;
94 }
95
96 DBG3("Created hashtable size %lu at %p of type %d", size, ht->ht, type);
97
98 return ht;
99
100 error:
101 return NULL;
102 }
103
104 /*
105 * Free a lttng hashtable.
106 */
107 void lttng_ht_destroy(struct lttng_ht *ht)
108 {
109 int ret;
110
111 ret = cds_lfht_destroy(ht->ht, NULL);
112 assert(!ret);
113 }
114
115 /*
116 * Init lttng ht node string.
117 */
118 void lttng_ht_node_init_str(struct lttng_ht_node_str *node, char *key)
119 {
120 assert(node);
121
122 node->key = key;
123 cds_lfht_node_init(&node->node);
124 }
125
126 /*
127 * Init lttng ht node unsigned long.
128 */
129 void lttng_ht_node_init_ulong(struct lttng_ht_node_ulong *node,
130 unsigned long key)
131 {
132 assert(node);
133
134 node->key = key;
135 cds_lfht_node_init(&node->node);
136 }
137
138 /*
139 * Free lttng ht node string.
140 */
141 void lttng_ht_node_free_str(struct lttng_ht_node_str *node)
142 {
143 assert(node);
144 free(node);
145 }
146
147 /*
148 * Free lttng ht node unsigned long.
149 */
150 void lttng_ht_node_free_ulong(struct lttng_ht_node_ulong *node)
151 {
152 assert(node);
153 free(node);
154 }
155
156 /*
157 * Lookup function in hashtable.
158 */
159 void lttng_ht_lookup(struct lttng_ht *ht, void *key,
160 struct lttng_ht_iter *iter)
161 {
162 assert(ht);
163 assert(ht->ht);
164
165 cds_lfht_lookup(ht->ht, ht->hash_fct(key, HASH_SEED),
166 ht->match_fct, key, &iter->iter);
167 }
168
169 /*
170 * Add unique string node to hashtable.
171 */
172 void lttng_ht_add_unique_str(struct lttng_ht *ht,
173 struct lttng_ht_node_str *node)
174 {
175 struct cds_lfht_node *node_ptr;
176 assert(ht);
177 assert(ht->ht);
178 assert(node);
179
180 node_ptr = cds_lfht_add_unique(ht->ht, ht->hash_fct(node->key, HASH_SEED),
181 ht->match_fct, node->key, &node->node);
182 assert(node_ptr == &node->node);
183 }
184
185 /*
186 * Add unique unsigned long node to hashtable.
187 */
188 void lttng_ht_add_unique_ulong(struct lttng_ht *ht,
189 struct lttng_ht_node_ulong *node)
190 {
191 struct cds_lfht_node *node_ptr;
192 assert(ht);
193 assert(ht->ht);
194 assert(node);
195
196 node_ptr = cds_lfht_add_unique(ht->ht,
197 ht->hash_fct((void *) node->key, HASH_SEED), ht->match_fct,
198 (void *) node->key, &node->node);
199 assert(node_ptr == &node->node);
200 }
201
202 /*
203 * Add replace unsigned long node to hashtable.
204 */
205 struct lttng_ht_node_ulong *lttng_ht_add_replace_ulong(struct lttng_ht *ht,
206 struct lttng_ht_node_ulong *node)
207 {
208 struct cds_lfht_node *node_ptr;
209 assert(ht);
210 assert(ht->ht);
211 assert(node);
212
213 node_ptr = cds_lfht_add_replace(ht->ht,
214 ht->hash_fct((void *) node->key, HASH_SEED), ht->match_fct,
215 (void *) node->key, &node->node);
216 if (!node_ptr) {
217 return NULL;
218 } else {
219 return caa_container_of(node_ptr, struct lttng_ht_node_ulong, node);
220 }
221 assert(node_ptr == &node->node);
222 }
223
224 /*
225 * Delete node from hashtable.
226 */
227 int lttng_ht_del(struct lttng_ht *ht, struct lttng_ht_iter *iter)
228 {
229 assert(ht);
230 assert(ht->ht);
231 assert(iter);
232
233 return cds_lfht_del(ht->ht, iter->iter.node);
234 }
235
236 /*
237 * Get first node in the hashtable.
238 */
239 void lttng_ht_get_first(struct lttng_ht *ht, struct lttng_ht_iter *iter)
240 {
241 assert(ht);
242 assert(ht->ht);
243 assert(iter);
244
245 cds_lfht_first(ht->ht, &iter->iter);
246 }
247
248 /*
249 * Get next node in the hashtable.
250 */
251 void lttng_ht_get_next(struct lttng_ht *ht, struct lttng_ht_iter *iter)
252 {
253 assert(ht);
254 assert(ht->ht);
255 assert(iter);
256
257 cds_lfht_next(ht->ht, &iter->iter);
258 }
259
260 /*
261 * Return the number of nodes in the hashtable.
262 */
263 unsigned long lttng_ht_get_count(struct lttng_ht *ht)
264 {
265 long scb, sca;
266 unsigned long count;
267
268 assert(ht);
269 assert(ht->ht);
270
271 cds_lfht_count_nodes(ht->ht, &scb, &count, &sca);
272
273 return count;
274 }
275
276 /*
277 * Return lttng ht string node from iterator.
278 */
279 struct lttng_ht_node_str *lttng_ht_iter_get_node_str(
280 struct lttng_ht_iter *iter)
281 {
282 struct cds_lfht_node *node;
283
284 assert(iter);
285 node = cds_lfht_iter_get_node(&iter->iter);
286 if (!node) {
287 return NULL;
288 }
289 return caa_container_of(node, struct lttng_ht_node_str, node);
290 }
291
292 /*
293 * Return lttng ht unsigned long node from iterator.
294 */
295 struct lttng_ht_node_ulong *lttng_ht_iter_get_node_ulong(
296 struct lttng_ht_iter *iter)
297 {
298 struct cds_lfht_node *node;
299
300 assert(iter);
301 node = cds_lfht_iter_get_node(&iter->iter);
302 if (!node) {
303 return NULL;
304 }
305 return caa_container_of(node, struct lttng_ht_node_ulong, node);
306 }
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