src/common/hashtable/hashtable.cpp

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "hashtable.hpp"
  10 #include "utils.hpp"
  11
  12 #include <common/common.hpp>
  13 #include <common/defaults.hpp>
  14
  15 #include <string.h>
  16 #include <urcu.h>
  17 #include <urcu/compiler.h>
  18
  19 /* seed_lock protects both seed_init and lttng_ht_seed. */
  20 static pthread_mutex_t seed_lock = PTHREAD_MUTEX_INITIALIZER;
  21 static bool seed_init;
  22
  23 static unsigned long min_hash_alloc_size = 1;
  24 static unsigned long max_hash_buckets_size = 0;
  25
  26 /*
  27  * Getter/lookup functions need to be called with RCU read-side lock
  28  * held. However, modification functions (add, add_unique, replace, del)
  29  * take the RCU lock internally, so it does not matter whether the
  30  * caller hold the RCU lock or not.
  31  */
  32
  33 /*
  34  * Match function for string node.
  35  */
  36 static int match_str(struct cds_lfht_node *node, const void *key)
  37 {
  38         struct lttng_ht_node_str *match_node =
  39                 lttng::utils::container_of(node, &lttng_ht_node_str::node);
  40
  41         return hash_match_key_str(match_node->key, (void *) key);
  42 }
  43
  44 /*
  45  * Match function for ulong node.
  46  */
  47 static int match_ulong(struct cds_lfht_node *node, const void *key)
  48 {
  49         struct lttng_ht_node_ulong *match_node =
  50                 lttng::utils::container_of(node, &lttng_ht_node_ulong::node);
  51
  52         return hash_match_key_ulong((void *) match_node->key, (void *) key);
  53 }
  54
  55 /*
  56  * Match function for u64 node.
  57  */
  58 static int match_u64(struct cds_lfht_node *node, const void *key)
  59 {
  60         struct lttng_ht_node_u64 *match_node =
  61                 lttng::utils::container_of(node, &lttng_ht_node_u64::node);
  62
  63         return hash_match_key_u64(&match_node->key, (void *) key);
  64 }
  65
  66 /*
  67  * Match function for two uint64_t node.
  68  */
  69 static int match_two_u64(struct cds_lfht_node *node, const void *key)
  70 {
  71         struct lttng_ht_node_two_u64 *match_node =
  72                 lttng::utils::container_of(node, &lttng_ht_node_two_u64::node);
  73
  74         return hash_match_key_two_u64((void *) &match_node->key, (void *) key);
  75 }
  76
  77 static inline const char *lttng_ht_type_str(enum lttng_ht_type type)
  78 {
  79         switch (type) {
  80         case LTTNG_HT_TYPE_STRING:
  81                 return "STRING";
  82         case LTTNG_HT_TYPE_ULONG:
  83                 return "ULONG";
  84         case LTTNG_HT_TYPE_U64:
  85                 return "U64";
  86         case LTTNG_HT_TYPE_TWO_U64:
  87                 return "TWO_U64";
  88         default:
  89                 ERR("Unknown lttng hashtable type %d", type);
  90                 abort();
  91         }
  92 }
  93
  94 /*
  95  * Return an allocated lttng hashtable.
  96  */
  97 struct lttng_ht *lttng_ht_new(unsigned long size, lttng_ht_type type)
  98 {
  99         struct lttng_ht *ht;
 100
 101         /* Test size */
 102         if (!size)
 103                 size = DEFAULT_HT_SIZE;
 104
 105         pthread_mutex_lock(&seed_lock);
 106         if (!seed_init) {
 107                 lttng_ht_seed = (unsigned long) time(NULL);
 108                 seed_init = true;
 109         }
 110         pthread_mutex_unlock(&seed_lock);
 111
 112         ht = zmalloc<lttng_ht>();
 113         if (ht == NULL) {
 114                 PERROR("zmalloc lttng_ht");
 115                 goto error;
 116         }
 117
 118         ht->ht = cds_lfht_new(size,
 119                               min_hash_alloc_size,
 120                               max_hash_buckets_size,
 121                               CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING,
 122                               NULL);
 123         /*
 124          * There is already an assert in the RCU hashtable code so if the ht is
 125          * NULL here there is a *huge* problem.
 126          */
 127         LTTNG_ASSERT(ht->ht);
 128
 129         switch (type) {
 130         case LTTNG_HT_TYPE_STRING:
 131                 ht->match_fct = match_str;
 132                 ht->hash_fct = hash_key_str;
 133                 break;
 134         case LTTNG_HT_TYPE_ULONG:
 135                 ht->match_fct = match_ulong;
 136                 ht->hash_fct = hash_key_ulong;
 137                 break;
 138         case LTTNG_HT_TYPE_U64:
 139                 ht->match_fct = match_u64;
 140                 ht->hash_fct = hash_key_u64;
 141                 break;
 142         case LTTNG_HT_TYPE_TWO_U64:
 143                 ht->match_fct = match_two_u64;
 144                 ht->hash_fct = hash_key_two_u64;
 145                 break;
 146         default:
 147                 ERR("Unknown lttng hashtable type %d", type);
 148                 lttng_ht_destroy(ht);
 149                 goto error;
 150         }
 151
 152         DBG3("Created hashtable size %lu at %p of type %s", size, ht->ht, lttng_ht_type_str(type));
 153
 154         return ht;
 155
 156 error:
 157         return NULL;
 158 }
 159
 160 /*
 161  * Free a lttng hashtable.
 162  */
 163 void lttng_ht_destroy(struct lttng_ht *ht)
 164 {
 165         int ret;
 166
 167         ret = cds_lfht_destroy(ht->ht, NULL);
 168         LTTNG_ASSERT(!ret);
 169         free(ht);
 170 }
 171
 172 /*
 173  * Init lttng ht node string.
 174  */
 175 void lttng_ht_node_init_str(struct lttng_ht_node_str *node, char *key)
 176 {
 177         LTTNG_ASSERT(node);
 178
 179         node->key = key;
 180         cds_lfht_node_init(&node->node);
 181 }
 182
 183 /*
 184  * Init lttng ht node unsigned long.
 185  */
 186 void lttng_ht_node_init_ulong(struct lttng_ht_node_ulong *node, unsigned long key)
 187 {
 188         LTTNG_ASSERT(node);
 189
 190         node->key = key;
 191         cds_lfht_node_init(&node->node);
 192 }
 193
 194 /*
 195  * Init lttng ht node uint64_t.
 196  */
 197 void lttng_ht_node_init_u64(struct lttng_ht_node_u64 *node, uint64_t key)
 198 {
 199         LTTNG_ASSERT(node);
 200
 201         node->key = key;
 202         cds_lfht_node_init(&node->node);
 203 }
 204
 205 /*
 206  * Init lttng ht node with two uint64_t.
 207  */
 208 void lttng_ht_node_init_two_u64(struct lttng_ht_node_two_u64 *node, uint64_t key1, uint64_t key2)
 209 {
 210         LTTNG_ASSERT(node);
 211
 212         node->key.key1 = key1;
 213         node->key.key2 = key2;
 214         cds_lfht_node_init(&node->node);
 215 }
 216
 217 /*
 218  * Free lttng ht node string.
 219  */
 220 void lttng_ht_node_free_str(struct lttng_ht_node_str *node)
 221 {
 222         LTTNG_ASSERT(node);
 223         free(node);
 224 }
 225
 226 /*
 227  * Free lttng ht node unsigned long.
 228  */
 229 void lttng_ht_node_free_ulong(struct lttng_ht_node_ulong *node)
 230 {
 231         LTTNG_ASSERT(node);
 232         free(node);
 233 }
 234
 235 /*
 236  * Free lttng ht node uint64_t.
 237  */
 238 void lttng_ht_node_free_u64(struct lttng_ht_node_u64 *node)
 239 {
 240         LTTNG_ASSERT(node);
 241         free(node);
 242 }
 243
 244 /*
 245  * Free lttng ht node two uint64_t.
 246  */
 247 void lttng_ht_node_free_two_u64(struct lttng_ht_node_two_u64 *node)
 248 {
 249         LTTNG_ASSERT(node);
 250         free(node);
 251 }
 252
 253 /*
 254  * Lookup function in hashtable.
 255  */
 256 void lttng_ht_lookup(struct lttng_ht *ht, const void *key, struct lttng_ht_iter *iter)
 257 {
 258         LTTNG_ASSERT(ht);
 259         LTTNG_ASSERT(ht->ht);
 260
 261         cds_lfht_lookup(ht->ht, ht->hash_fct(key, lttng_ht_seed), ht->match_fct, key, &iter->iter);
 262 }
 263
 264 /*
 265  * Add unique string node to hashtable.
 266  */
 267 void lttng_ht_add_unique_str(struct lttng_ht *ht, struct lttng_ht_node_str *node)
 268 {
 269         struct cds_lfht_node *node_ptr;
 270         LTTNG_ASSERT(ht);
 271         LTTNG_ASSERT(ht->ht);
 272         LTTNG_ASSERT(node);
 273
 274         /* RCU read lock protects from ABA. */
 275         rcu_read_lock();
 276         node_ptr = cds_lfht_add_unique(ht->ht,
 277                                        ht->hash_fct(node->key, lttng_ht_seed),
 278                                        ht->match_fct,
 279                                        node->key,
 280                                        &node->node);
 281         rcu_read_unlock();
 282         LTTNG_ASSERT(node_ptr == &node->node);
 283 }
 284
 285 /*
 286  * Add string node to hashtable.
 287  */
 288 void lttng_ht_add_str(struct lttng_ht *ht, struct lttng_ht_node_str *node)
 289 {
 290         LTTNG_ASSERT(ht);
 291         LTTNG_ASSERT(ht->ht);
 292         LTTNG_ASSERT(node);
 293
 294         /* RCU read lock protects from ABA. */
 295         rcu_read_lock();
 296         cds_lfht_add(ht->ht, ht->hash_fct(node->key, lttng_ht_seed), &node->node);
 297         rcu_read_unlock();
 298 }
 299
 300 /*
 301  * Add unsigned long node to hashtable.
 302  */
 303 void lttng_ht_add_ulong(struct lttng_ht *ht, struct lttng_ht_node_ulong *node)
 304 {
 305         LTTNG_ASSERT(ht);
 306         LTTNG_ASSERT(ht->ht);
 307         LTTNG_ASSERT(node);
 308
 309         /* RCU read lock protects from ABA. */
 310         rcu_read_lock();
 311         cds_lfht_add(ht->ht, ht->hash_fct((void *) node->key, lttng_ht_seed), &node->node);
 312         rcu_read_unlock();
 313 }
 314
 315 /*
 316  * Add uint64_t node to hashtable.
 317  */
 318 void lttng_ht_add_u64(struct lttng_ht *ht, struct lttng_ht_node_u64 *node)
 319 {
 320         LTTNG_ASSERT(ht);
 321         LTTNG_ASSERT(ht->ht);
 322         LTTNG_ASSERT(node);
 323
 324         /* RCU read lock protects from ABA. */
 325         rcu_read_lock();
 326         cds_lfht_add(ht->ht, ht->hash_fct(&node->key, lttng_ht_seed), &node->node);
 327         rcu_read_unlock();
 328 }
 329
 330 /*
 331  * Add unique unsigned long node to hashtable.
 332  */
 333 void lttng_ht_add_unique_ulong(struct lttng_ht *ht, struct lttng_ht_node_ulong *node)
 334 {
 335         struct cds_lfht_node *node_ptr;
 336         LTTNG_ASSERT(ht);
 337         LTTNG_ASSERT(ht->ht);
 338         LTTNG_ASSERT(node);
 339
 340         /* RCU read lock protects from ABA. */
 341         rcu_read_lock();
 342         node_ptr = cds_lfht_add_unique(ht->ht,
 343                                        ht->hash_fct((void *) node->key, lttng_ht_seed),
 344                                        ht->match_fct,
 345                                        (void *) node->key,
 346                                        &node->node);
 347         rcu_read_unlock();
 348         LTTNG_ASSERT(node_ptr == &node->node);
 349 }
 350
 351 /*
 352  * Add unique uint64_t node to hashtable.
 353  */
 354 void lttng_ht_add_unique_u64(struct lttng_ht *ht, struct lttng_ht_node_u64 *node)
 355 {
 356         struct cds_lfht_node *node_ptr;
 357         LTTNG_ASSERT(ht);
 358         LTTNG_ASSERT(ht->ht);
 359         LTTNG_ASSERT(node);
 360
 361         /* RCU read lock protects from ABA. */
 362         rcu_read_lock();
 363         node_ptr = cds_lfht_add_unique(ht->ht,
 364                                        ht->hash_fct(&node->key, lttng_ht_seed),
 365                                        ht->match_fct,
 366                                        &node->key,
 367                                        &node->node);
 368         rcu_read_unlock();
 369         LTTNG_ASSERT(node_ptr == &node->node);
 370 }
 371
 372 /*
 373  * Add unique two uint64_t node to hashtable.
 374  */
 375 void lttng_ht_add_unique_two_u64(struct lttng_ht *ht, struct lttng_ht_node_two_u64 *node)
 376 {
 377         struct cds_lfht_node *node_ptr;
 378         LTTNG_ASSERT(ht);
 379         LTTNG_ASSERT(ht->ht);
 380         LTTNG_ASSERT(node);
 381
 382         /* RCU read lock protects from ABA. */
 383         rcu_read_lock();
 384         node_ptr = cds_lfht_add_unique(ht->ht,
 385                                        ht->hash_fct((void *) &node->key, lttng_ht_seed),
 386                                        ht->match_fct,
 387                                        (void *) &node->key,
 388                                        &node->node);
 389         rcu_read_unlock();
 390         LTTNG_ASSERT(node_ptr == &node->node);
 391 }
 392
 393 /*
 394  * Add replace unsigned long node to hashtable.
 395  */
 396 struct lttng_ht_node_ulong *lttng_ht_add_replace_ulong(struct lttng_ht *ht,
 397                                                        struct lttng_ht_node_ulong *node)
 398 {
 399         struct cds_lfht_node *node_ptr;
 400         LTTNG_ASSERT(ht);
 401         LTTNG_ASSERT(ht->ht);
 402         LTTNG_ASSERT(node);
 403
 404         /* RCU read lock protects from ABA. */
 405         rcu_read_lock();
 406         node_ptr = cds_lfht_add_replace(ht->ht,
 407                                         ht->hash_fct((void *) node->key, lttng_ht_seed),
 408                                         ht->match_fct,
 409                                         (void *) node->key,
 410                                         &node->node);
 411         rcu_read_unlock();
 412         if (!node_ptr) {
 413                 return NULL;
 414         } else {
 415                 return lttng::utils::container_of(node_ptr, &lttng_ht_node_ulong::node);
 416         }
 417         LTTNG_ASSERT(node_ptr == &node->node);
 418 }
 419
 420 /*
 421  * Add replace unsigned long node to hashtable.
 422  */
 423 struct lttng_ht_node_u64 *lttng_ht_add_replace_u64(struct lttng_ht *ht,
 424                                                    struct lttng_ht_node_u64 *node)
 425 {
 426         struct cds_lfht_node *node_ptr;
 427         LTTNG_ASSERT(ht);
 428         LTTNG_ASSERT(ht->ht);
 429         LTTNG_ASSERT(node);
 430
 431         /* RCU read lock protects from ABA. */
 432         rcu_read_lock();
 433         node_ptr = cds_lfht_add_replace(ht->ht,
 434                                         ht->hash_fct(&node->key, lttng_ht_seed),
 435                                         ht->match_fct,
 436                                         &node->key,
 437                                         &node->node);
 438         rcu_read_unlock();
 439         if (!node_ptr) {
 440                 return NULL;
 441         } else {
 442                 return lttng::utils::container_of(node_ptr, &lttng_ht_node_u64::node);
 443         }
 444         LTTNG_ASSERT(node_ptr == &node->node);
 445 }
 446
 447 /*
 448  * Delete node from hashtable.
 449  */
 450 int lttng_ht_del(struct lttng_ht *ht, struct lttng_ht_iter *iter)
 451 {
 452         int ret;
 453
 454         LTTNG_ASSERT(ht);
 455         LTTNG_ASSERT(ht->ht);
 456         LTTNG_ASSERT(iter);
 457
 458         /* RCU read lock protects from ABA. */
 459         rcu_read_lock();
 460         ret = cds_lfht_del(ht->ht, iter->iter.node);
 461         rcu_read_unlock();
 462         return ret;
 463 }
 464
 465 /*
 466  * Get first node in the hashtable.
 467  */
 468 void lttng_ht_get_first(struct lttng_ht *ht, struct lttng_ht_iter *iter)
 469 {
 470         LTTNG_ASSERT(ht);
 471         LTTNG_ASSERT(ht->ht);
 472         LTTNG_ASSERT(iter);
 473
 474         cds_lfht_first(ht->ht, &iter->iter);
 475 }
 476
 477 /*
 478  * Get next node in the hashtable.
 479  */
 480 void lttng_ht_get_next(struct lttng_ht *ht, struct lttng_ht_iter *iter)
 481 {
 482         LTTNG_ASSERT(ht);
 483         LTTNG_ASSERT(ht->ht);
 484         LTTNG_ASSERT(iter);
 485
 486         cds_lfht_next(ht->ht, &iter->iter);
 487 }
 488
 489 /*
 490  * Return the number of nodes in the hashtable.
 491  */
 492 unsigned long lttng_ht_get_count(struct lttng_ht *ht)
 493 {
 494         long scb, sca;
 495         unsigned long count;
 496
 497         LTTNG_ASSERT(ht);
 498         LTTNG_ASSERT(ht->ht);
 499
 500         /* RCU read lock protects from ABA and allows RCU traversal. */
 501         rcu_read_lock();
 502         cds_lfht_count_nodes(ht->ht, &scb, &count, &sca);
 503         rcu_read_unlock();
 504
 505         return count;
 506 }
 507
 508 /*
 509  * Return lttng ht string node from iterator.
 510  */
 511 struct lttng_ht_node_str *lttng_ht_iter_get_node_str(struct lttng_ht_iter *iter)
 512 {
 513         struct cds_lfht_node *node;
 514
 515         LTTNG_ASSERT(iter);
 516         node = cds_lfht_iter_get_node(&iter->iter);
 517         if (!node) {
 518                 return NULL;
 519         }
 520         return lttng::utils::container_of(node, &lttng_ht_node_str::node);
 521 }
 522
 523 /*
 524  * Return lttng ht unsigned long node from iterator.
 525  */
 526 struct lttng_ht_node_ulong *lttng_ht_iter_get_node_ulong(struct lttng_ht_iter *iter)
 527 {
 528         struct cds_lfht_node *node;
 529
 530         LTTNG_ASSERT(iter);
 531         node = cds_lfht_iter_get_node(&iter->iter);
 532         if (!node) {
 533                 return NULL;
 534         }
 535         return lttng::utils::container_of(node, &lttng_ht_node_ulong::node);
 536 }
 537
 538 /*
 539  * Return lttng ht unsigned long node from iterator.
 540  */
 541 struct lttng_ht_node_u64 *lttng_ht_iter_get_node_u64(struct lttng_ht_iter *iter)
 542 {
 543         struct cds_lfht_node *node;
 544
 545         LTTNG_ASSERT(iter);
 546         node = cds_lfht_iter_get_node(&iter->iter);
 547         if (!node) {
 548                 return NULL;
 549         }
 550         return lttng::utils::container_of(node, &lttng_ht_node_u64::node);
 551 }
 552
 553 /*
 554  * Return lttng ht stream and index id node from iterator.
 555  */
 556 struct lttng_ht_node_two_u64 *lttng_ht_iter_get_node_two_u64(struct lttng_ht_iter *iter)
 557 {
 558         struct cds_lfht_node *node;
 559
 560         LTTNG_ASSERT(iter);
 561         node = cds_lfht_iter_get_node(&iter->iter);
 562         if (!node) {
 563                 return NULL;
 564         }
 565         return lttng::utils::container_of(node, &lttng_ht_node_two_u64::node);
 566 }