include/urcu/rculfhash.h

   1 #ifndef _URCU_RCULFHASH_H
   2 #define _URCU_RCULFHASH_H
   3
   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>
  10  * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
  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
  25  *
  26  * For use with URCU_API_MAP (API mapping of liburcu), include this file
  27  * _after_ including your URCU flavor.
  28  */
  29
  30 #include <urcu/config.h>
  31 #include <stdint.h>
  32 #include <pthread.h>
  33 #include <urcu/compiler.h>
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 struct cds_lfht;
  40
  41 /*
  42  * cds_lfht_node: Contains the next pointers and reverse-hash
  43  * value required for lookup and traversal of the hash table.
  44  *
  45  * struct cds_lfht_node should be aligned on 8-bytes boundaries because
  46  * the three lower bits are used as flags. It is worth noting that the
  47  * information contained within these three bits could be represented on
  48  * two bits by re-using the same bit for REMOVAL_OWNER_FLAG and
  49  * BUCKET_FLAG. This can be done if we ensure that no iterator nor
  50  * updater check the BUCKET_FLAG after it detects that the REMOVED_FLAG
  51  * is set. Given the minimum size of struct cds_lfht_node is 8 bytes on
  52  * 32-bit architectures, we choose to go for simplicity and reserve
  53  * three bits.
  54  *
  55  * struct cds_lfht_node can be embedded into a structure (as a field).
  56  * caa_container_of() can be used to get the structure from the struct
  57  * cds_lfht_node after a lookup.
  58  *
  59  * The structure which embeds it typically holds the key (or key-value
  60  * pair) of the object. The caller code is responsible for calculation
  61  * of the hash value for cds_lfht APIs.
  62  */
  63 struct cds_lfht_node {
  64         struct cds_lfht_node *next;     /* ptr | REMOVAL_OWNER_FLAG | BUCKET_FLAG | REMOVED_FLAG */
  65         unsigned long reverse_hash;
  66 } __attribute__((aligned(8)));
  67
  68 /* cds_lfht_iter: Used to track state while traversing a hash chain. */
  69 struct cds_lfht_iter {
  70         struct cds_lfht_node *node, *next;
  71         /*
  72          * For debugging purposes, build both API users and rculfhash
  73          * library with CDS_LFHT_ITER_DEBUG defined. This enables extra
  74          * consistency checks for calls to a cds_lfht_next() or
  75          * cds_lfht_next_duplicate() after the iterator has been
  76          * re-purposed to iterate on a different hash table. This is a
  77          * common programming mistake when performing hash table lookup
  78          * nested in a hash table traversal.
  79          */
  80 #ifdef CONFIG_CDS_LFHT_ITER_DEBUG
  81         struct cds_lfht *lfht;
  82 #endif
  83 };
  84
  85 static inline
  86 struct cds_lfht_node *cds_lfht_iter_get_node(struct cds_lfht_iter *iter)
  87 {
  88         return iter->node;
  89 }
  90
  91 struct rcu_flavor_struct;
  92
  93 /*
  94  * Caution !
  95  * Ensure reader and writer threads are registered as urcu readers.
  96  */
  97
  98 typedef int (*cds_lfht_match_fct)(struct cds_lfht_node *node, const void *key);
  99
 100 /*
 101  * cds_lfht_node_init - initialize a hash table node
 102  * @node: the node to initialize.
 103  *
 104  * This function is kept to be eventually used for debugging purposes
 105  * (detection of memory corruption).
 106  */
 107 static inline
 108 void cds_lfht_node_init(struct cds_lfht_node *node __attribute__((unused)))
 109 {
 110 }
 111
 112 /*
 113  * cds_lfht_node_init_deleted - initialize a hash table node to "removed" state
 114  * @node: the node to initialize.
 115  *
 116  * Initialize the node such that cds_lfht_is_node_deleted() can be used
 117  * on the node before it is added to a hash table.
 118  */
 119 extern
 120 void cds_lfht_node_init_deleted(struct cds_lfht_node *node);
 121
 122 /*
 123  * Hash table creation flags.
 124  */
 125 enum {
 126         CDS_LFHT_AUTO_RESIZE = (1U << 0),
 127         CDS_LFHT_ACCOUNTING = (1U << 1),
 128 };
 129
 130 struct cds_lfht_mm_type {
 131         struct cds_lfht *(*alloc_cds_lfht)(unsigned long min_nr_alloc_buckets,
 132                         unsigned long max_nr_buckets);
 133         void (*alloc_bucket_table)(struct cds_lfht *ht, unsigned long order);
 134         void (*free_bucket_table)(struct cds_lfht *ht, unsigned long order);
 135         struct cds_lfht_node *(*bucket_at)(struct cds_lfht *ht,
 136                         unsigned long index);
 137 };
 138
 139 extern const struct cds_lfht_mm_type cds_lfht_mm_order;
 140 extern const struct cds_lfht_mm_type cds_lfht_mm_chunk;
 141 extern const struct cds_lfht_mm_type cds_lfht_mm_mmap;
 142
 143 /*
 144  * _cds_lfht_new - API used by cds_lfht_new wrapper. Do not use directly.
 145  */
 146 extern
 147 struct cds_lfht *_cds_lfht_new(unsigned long init_size,
 148                         unsigned long min_nr_alloc_buckets,
 149                         unsigned long max_nr_buckets,
 150                         int flags,
 151                         const struct cds_lfht_mm_type *mm,
 152                         const struct rcu_flavor_struct *flavor,
 153                         pthread_attr_t *attr);
 154
 155 /*
 156  * cds_lfht_new_flavor - allocate a hash table tied to a RCU flavor.
 157  * @init_size: number of buckets to allocate initially. Must be power of two.
 158  * @min_nr_alloc_buckets: the minimum number of allocated buckets.
 159  *                        (must be power of two)
 160  * @max_nr_buckets: the maximum number of hash table buckets allowed.
 161  *                  (must be power of two, 0 is accepted, means
 162  *                  "infinite")
 163  * @flavor: flavor of liburcu to use to synchronize the hash table
 164  * @flags: hash table creation flags (can be combined with bitwise or: '|').
 165  *           0: no flags.
 166  *           CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
 167  *           CDS_LFHT_ACCOUNTING: count the number of node addition
 168  *                                and removal in the table
 169  * @attr: optional resize worker thread attributes. NULL for default.
 170  *
 171  * Return NULL on error.
 172  * Note: the RCU flavor must be already included before the hash table header.
 173  *
 174  * The programmer is responsible for ensuring that resize operation has a
 175  * priority equal to hash table updater threads. It should be performed by
 176  * specifying the appropriate priority in the pthread "attr" argument, and,
 177  * for CDS_LFHT_AUTO_RESIZE, by ensuring that call_rcu worker threads also have
 178  * this priority level. Having lower priority for call_rcu and resize threads
 179  * does not pose any correctness issue, but the resize operations could be
 180  * starved by updates, thus leading to long hash table bucket chains.
 181  * Threads calling cds_lfht_new are NOT required to be registered RCU
 182  * read-side threads. It can be called very early. (e.g. before RCU is
 183  * initialized)
 184  */
 185 static inline
 186 struct cds_lfht *cds_lfht_new_flavor(unsigned long init_size,
 187                         unsigned long min_nr_alloc_buckets,
 188                         unsigned long max_nr_buckets,
 189                         int flags,
 190                         const struct rcu_flavor_struct *flavor,
 191                         pthread_attr_t *attr)
 192 {
 193         return _cds_lfht_new(init_size, min_nr_alloc_buckets, max_nr_buckets,
 194                         flags, NULL, flavor, attr);
 195 }
 196
 197
 198 #ifdef URCU_API_MAP
 199 /*
 200  * cds_lfht_new - allocate a hash table.
 201  * @init_size: number of buckets to allocate initially. Must be power of two.
 202  * @min_nr_alloc_buckets: the minimum number of allocated buckets.
 203  *                        (must be power of two)
 204  * @max_nr_buckets: the maximum number of hash table buckets allowed.
 205  *                  (must be power of two, 0 is accepted, means
 206  *                  "infinite")
 207  * @flags: hash table creation flags (can be combined with bitwise or: '|').
 208  *           0: no flags.
 209  *           CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
 210  *           CDS_LFHT_ACCOUNTING: count the number of node addition
 211  *                                and removal in the table
 212  * @attr: optional resize worker thread attributes. NULL for default.
 213  *
 214  * Return NULL on error.
 215  * Note: the RCU flavor must be already included before the hash table header.
 216  *
 217  * The programmer is responsible for ensuring that resize operation has a
 218  * priority equal to hash table updater threads. It should be performed by
 219  * specifying the appropriate priority in the pthread "attr" argument, and,
 220  * for CDS_LFHT_AUTO_RESIZE, by ensuring that call_rcu worker threads also have
 221  * this priority level. Having lower priority for call_rcu and resize threads
 222  * does not pose any correctness issue, but the resize operations could be
 223  * starved by updates, thus leading to long hash table bucket chains.
 224  * Threads calling cds_lfht_new are NOT required to be registered RCU
 225  * read-side threads. It can be called very early. (e.g. before RCU is
 226  * initialized)
 227  */
 228 static inline
 229 struct cds_lfht *cds_lfht_new(unsigned long init_size,
 230                         unsigned long min_nr_alloc_buckets,
 231                         unsigned long max_nr_buckets,
 232                         int flags,
 233                         pthread_attr_t *attr)
 234 {
 235         return _cds_lfht_new(init_size, min_nr_alloc_buckets, max_nr_buckets,
 236                         flags, NULL, &rcu_flavor, attr);
 237 }
 238 #endif /* URCU_API_MAP */
 239
 240 /*
 241  * cds_lfht_destroy - destroy a hash table.
 242  * @ht: the hash table to destroy.
 243  * @attr: (output) resize worker thread attributes, as received by cds_lfht_new.
 244  *        The caller will typically want to free this pointer if dynamically
 245  *        allocated. The attr point can be NULL if the caller does not
 246  *        need to be informed of the value passed to cds_lfht_new().
 247  *
 248  * Return 0 on success, negative error value on error.
 249
 250  * Prior to liburcu 0.10:
 251  * - Threads calling this API need to be registered RCU read-side
 252  *   threads.
 253  * - cds_lfht_destroy should *not* be called from a RCU read-side
 254  *   critical section. It should *not* be called from a call_rcu thread
 255  *   context neither.
 256  *
 257  * Starting from liburcu 0.10, rculfhash implements its own worker
 258  * thread to handle resize operations, which removes RCU requirements on
 259  * cds_lfht_destroy.
 260  */
 261 extern
 262 int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
 263
 264 /*
 265  * cds_lfht_count_nodes - count the number of nodes in the hash table.
 266  * @ht: the hash table.
 267  * @split_count_before: sample the node count split-counter before traversal.
 268  * @count: traverse the hash table, count the number of nodes observed.
 269  * @split_count_after: sample the node count split-counter after traversal.
 270  *
 271  * Call with rcu_read_lock held.
 272  * Threads calling this API need to be registered RCU read-side threads.
 273  */
 274 extern
 275 void cds_lfht_count_nodes(struct cds_lfht *ht,
 276                 long *split_count_before,
 277                 unsigned long *count,
 278                 long *split_count_after);
 279
 280 /*
 281  * cds_lfht_lookup - lookup a node by key.
 282  * @ht: the hash table.
 283  * @hash: the key hash.
 284  * @match: the key match function.
 285  * @key: the current node key.
 286  * @iter: node, if found (output). *iter->node set to NULL if not found.
 287  *
 288  * Call with rcu_read_lock held.
 289  * Threads calling this API need to be registered RCU read-side threads.
 290  * This function acts as a rcu_dereference() to read the node pointer.
 291  */
 292 extern
 293 void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
 294                 cds_lfht_match_fct match, const void *key,
 295                 struct cds_lfht_iter *iter);
 296
 297 /*
 298  * cds_lfht_next_duplicate - get the next item with same key, after iterator.
 299  * @ht: the hash table.
 300  * @match: the key match function.
 301  * @key: the current node key.
 302  * @iter: input: current iterator.
 303  *        output: node, if found. *iter->node set to NULL if not found.
 304  *
 305  * Uses an iterator initialized by a lookup or traversal. Important: the
 306  * iterator _needs_ to be initialized before calling
 307  * cds_lfht_next_duplicate.
 308  * Sets *iter-node to the following node with same key.
 309  * Sets *iter->node to NULL if no following node exists with same key.
 310  * RCU read-side lock must be held across cds_lfht_lookup and
 311  * cds_lfht_next calls, and also between cds_lfht_next calls using the
 312  * node returned by a previous cds_lfht_next.
 313  * Call with rcu_read_lock held.
 314  * Threads calling this API need to be registered RCU read-side threads.
 315  * This function acts as a rcu_dereference() to read the node pointer.
 316  */
 317 extern
 318 void cds_lfht_next_duplicate(struct cds_lfht *ht,
 319                 cds_lfht_match_fct match, const void *key,
 320                 struct cds_lfht_iter *iter);
 321
 322 /*
 323  * cds_lfht_first - get the first node in the table.
 324  * @ht: the hash table.
 325  * @iter: First node, if exists (output). *iter->node set to NULL if not found.
 326  *
 327  * Output in "*iter". *iter->node set to NULL if table is empty.
 328  * Call with rcu_read_lock held.
 329  * Threads calling this API need to be registered RCU read-side threads.
 330  * This function acts as a rcu_dereference() to read the node pointer.
 331  */
 332 extern
 333 void cds_lfht_first(struct cds_lfht *ht, struct cds_lfht_iter *iter);
 334
 335 /*
 336  * cds_lfht_next - get the next node in the table.
 337  * @ht: the hash table.
 338  * @iter: input: current iterator.
 339  *        output: next node, if exists. *iter->node set to NULL if not found.
 340  *
 341  * Input/Output in "*iter". *iter->node set to NULL if *iter was
 342  * pointing to the last table node.
 343  * Call with rcu_read_lock held.
 344  * Threads calling this API need to be registered RCU read-side threads.
 345  * This function acts as a rcu_dereference() to read the node pointer.
 346  */
 347 extern
 348 void cds_lfht_next(struct cds_lfht *ht, struct cds_lfht_iter *iter);
 349
 350 /*
 351  * cds_lfht_add - add a node to the hash table.
 352  * @ht: the hash table.
 353  * @hash: the key hash.
 354  * @node: the node to add.
 355  *
 356  * This function supports adding redundant keys into the table.
 357  * Call with rcu_read_lock held.
 358  * Threads calling this API need to be registered RCU read-side threads.
 359  * This function issues a full memory barrier before and after its
 360  * atomic commit.
 361  */
 362 extern
 363 void cds_lfht_add(struct cds_lfht *ht, unsigned long hash,
 364                 struct cds_lfht_node *node);
 365
 366 /*
 367  * cds_lfht_add_unique - add a node to hash table, if key is not present.
 368  * @ht: the hash table.
 369  * @hash: the node's hash.
 370  * @match: the key match function.
 371  * @key: the node's key.
 372  * @node: the node to try adding.
 373  *
 374  * Return the node added upon success.
 375  * Return the unique node already present upon failure. If
 376  * cds_lfht_add_unique fails, the node passed as parameter should be
 377  * freed by the caller. In this case, the caller does NOT need to wait
 378  * for a grace period before freeing or re-using the node.
 379  * Call with rcu_read_lock held.
 380  * Threads calling this API need to be registered RCU read-side threads.
 381  *
 382  * The semantic of this function is that if only this function is used
 383  * to add keys into the table, no duplicated keys should ever be
 384  * observable in the table. The same guarantee apply for combination of
 385  * add_unique and add_replace (see below).
 386  *
 387  * Upon success, this function issues a full memory barrier before and
 388  * after its atomic commit. Upon failure, this function acts like a
 389  * simple lookup operation: it acts as a rcu_dereference() to read the
 390  * node pointer. The failure case does not guarantee any other memory
 391  * barrier.
 392  */
 393 extern
 394 struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
 395                 unsigned long hash,
 396                 cds_lfht_match_fct match,
 397                 const void *key,
 398                 struct cds_lfht_node *node);
 399
 400 /*
 401  * cds_lfht_add_replace - replace or add a node within hash table.
 402  * @ht: the hash table.
 403  * @hash: the node's hash.
 404  * @match: the key match function.
 405  * @key: the node's key.
 406  * @node: the node to add.
 407  *
 408  * Return the node replaced upon success. If no node matching the key
 409  * was present, return NULL, which also means the operation succeeded.
 410  * This replacement operation should never fail.
 411  * Call with rcu_read_lock held.
 412  * Threads calling this API need to be registered RCU read-side threads.
 413  * After successful replacement, a grace period must be waited for before
 414  * freeing or re-using the memory reserved for the returned node.
 415  *
 416  * The semantic of replacement vs lookups and traversals is the
 417  * following: if lookups and traversals are performed between a key
 418  * unique insertion and its removal, we guarantee that the lookups and
 419  * traversals will always find exactly one instance of the key if it is
 420  * replaced concurrently with the lookups.
 421  *
 422  * Providing this semantic allows us to ensure that replacement-only
 423  * schemes will never generate duplicated keys. It also allows us to
 424  * guarantee that a combination of add_replace and add_unique updates
 425  * will never generate duplicated keys.
 426  *
 427  * This function issues a full memory barrier before and after its
 428  * atomic commit.
 429  */
 430 extern
 431 struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
 432                 unsigned long hash,
 433                 cds_lfht_match_fct match,
 434                 const void *key,
 435                 struct cds_lfht_node *node);
 436
 437 /*
 438  * cds_lfht_replace - replace a node pointed to by iter within hash table.
 439  * @ht: the hash table.
 440  * @old_iter: the iterator position of the node to replace.
 441  * @hash: the node's hash.
 442  * @match: the key match function.
 443  * @key: the node's key.
 444  * @new_node: the new node to use as replacement.
 445  *
 446  * Return 0 if replacement is successful, negative value otherwise.
 447  * Replacing a NULL old node or an already removed node will fail with
 448  * -ENOENT.
 449  * If the hash or value of the node to replace and the new node differ,
 450  * this function returns -EINVAL without proceeding to the replacement.
 451  * Old node can be looked up with cds_lfht_lookup and cds_lfht_next.
 452  * RCU read-side lock must be held between lookup and replacement.
 453  * Call with rcu_read_lock held.
 454  * Threads calling this API need to be registered RCU read-side threads.
 455  * After successful replacement, a grace period must be waited for before
 456  * freeing or re-using the memory reserved for the old node (which can
 457  * be accessed with cds_lfht_iter_get_node).
 458  *
 459  * The semantic of replacement vs lookups is the same as
 460  * cds_lfht_add_replace().
 461  *
 462  * Upon success, this function issues a full memory barrier before and
 463  * after its atomic commit. Upon failure, this function does not issue
 464  * any memory barrier.
 465  */
 466 extern
 467 int cds_lfht_replace(struct cds_lfht *ht,
 468                 struct cds_lfht_iter *old_iter,
 469                 unsigned long hash,
 470                 cds_lfht_match_fct match,
 471                 const void *key,
 472                 struct cds_lfht_node *new_node);
 473
 474 /*
 475  * cds_lfht_del - remove node pointed to by iterator from hash table.
 476  * @ht: the hash table.
 477  * @node: the node to delete.
 478  *
 479  * Return 0 if the node is successfully removed, negative value
 480  * otherwise.
 481  * Deleting a NULL node or an already removed node will fail with a
 482  * negative value.
 483  * Node can be looked up with cds_lfht_lookup and cds_lfht_next,
 484  * followed by use of cds_lfht_iter_get_node.
 485  * RCU read-side lock must be held between lookup and removal.
 486  * Call with rcu_read_lock held.
 487  * Threads calling this API need to be registered RCU read-side threads.
 488  * After successful removal, a grace period must be waited for before
 489  * freeing or re-using the memory reserved for old node (which can be
 490  * accessed with cds_lfht_iter_get_node).
 491  * Upon success, this function issues a full memory barrier before and
 492  * after its atomic commit. Upon failure, this function does not issue
 493  * any memory barrier.
 494  */
 495 extern
 496 int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_node *node);
 497
 498 /*
 499  * cds_lfht_is_node_deleted - query whether a node is removed from hash table.
 500  *
 501  * Return non-zero if the node is deleted from the hash table, 0
 502  * otherwise.
 503  * Node can be looked up with cds_lfht_lookup and cds_lfht_next,
 504  * followed by use of cds_lfht_iter_get_node.
 505  * RCU read-side lock must be held between lookup and call to this
 506  * function.
 507  * Call with rcu_read_lock held.
 508  * Threads calling this API need to be registered RCU read-side threads.
 509  * This function does not issue any memory barrier.
 510  */
 511 extern
 512 int cds_lfht_is_node_deleted(const struct cds_lfht_node *node);
 513
 514 /*
 515  * cds_lfht_resize - Force a hash table resize
 516  * @ht: the hash table.
 517  * @new_size: update to this hash table size.
 518  *
 519  * Threads calling this API need to be registered RCU read-side threads.
 520  * This function does not (necessarily) issue memory barriers.
 521  * cds_lfht_resize should *not* be called from a RCU read-side critical
 522  * section.
 523  */
 524 extern
 525 void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
 526
 527 /*
 528  * Note: it is safe to perform element removal (del), replacement, or
 529  * any hash table update operation during any of the following hash
 530  * table traversals.
 531  * These functions act as rcu_dereference() to read the node pointers.
 532  */
 533 #define cds_lfht_for_each(ht, iter, node)                               \
 534         for (cds_lfht_first(ht, iter),                                  \
 535                         node = cds_lfht_iter_get_node(iter);            \
 536                 node != NULL;                                           \
 537                 cds_lfht_next(ht, iter),                                \
 538                         node = cds_lfht_iter_get_node(iter))
 539
 540 #define cds_lfht_for_each_duplicate(ht, hash, match, key, iter, node)   \
 541         for (cds_lfht_lookup(ht, hash, match, key, iter),               \
 542                         node = cds_lfht_iter_get_node(iter);            \
 543                 node != NULL;                                           \
 544                 cds_lfht_next_duplicate(ht, match, key, iter),          \
 545                         node = cds_lfht_iter_get_node(iter))
 546
 547 #define cds_lfht_for_each_entry(ht, iter, pos, member)                  \
 548         for (cds_lfht_first(ht, iter),                                  \
 549                         pos = caa_container_of(cds_lfht_iter_get_node(iter), \
 550                                         __typeof__(*(pos)), member);    \
 551                 cds_lfht_iter_get_node(iter) != NULL;                   \
 552                 cds_lfht_next(ht, iter),                                \
 553                         pos = caa_container_of(cds_lfht_iter_get_node(iter), \
 554                                         __typeof__(*(pos)), member))
 555
 556 #define cds_lfht_for_each_entry_duplicate(ht, hash, match, key,         \
 557                                 iter, pos, member)                      \
 558         for (cds_lfht_lookup(ht, hash, match, key, iter),               \
 559                         pos = caa_container_of(cds_lfht_iter_get_node(iter), \
 560                                         __typeof__(*(pos)), member);    \
 561                 cds_lfht_iter_get_node(iter) != NULL;                   \
 562                 cds_lfht_next_duplicate(ht, match, key, iter),          \
 563                         pos = caa_container_of(cds_lfht_iter_get_node(iter), \
 564                                         __typeof__(*(pos)), member))
 565
 566 #ifdef __cplusplus
 567 }
 568 #endif
 569
 570 #endif /* _URCU_RCULFHASH_H */