X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Frculfhash.h;h=8f501ea29b7b1e549c9b2d87f9ecf2e769251af0;hp=1aa98c5618b25da6219e87c0e15ec60dfc2ea2e5;hb=bce63dfd0a2306452c9e39f5df01789e77f3f44a;hpb=f000907d757239af9a08625b850b93b4ef6db508 diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h index 1aa98c5..8f501ea 100644 --- a/urcu/rculfhash.h +++ b/urcu/rculfhash.h @@ -1,56 +1,169 @@ #ifndef _URCU_RCULFHASH_H #define _URCU_RCULFHASH_H +/* + * urcu/rculfhash.h + * + * Userspace RCU library - Lock-Free RCU Hash Table + * + * Copyright 2011 - Mathieu Desnoyers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + #include #include -struct rcu_ht_node { - struct rcu_ht_node *next; - void *key; - unsigned long hash; +#ifdef __cplusplus +extern "C" { +#endif + +/* + * struct cds_lfht_node and struct _cds_lfht_node should be aligned on + * 4-bytes boundaries because the two lower bits are used as flags. + */ + +struct _cds_lfht_node { + struct cds_lfht_node *next; /* ptr | DUMMY_FLAG | REMOVED_FLAG */ unsigned long reverse_hash; - unsigned int dummy; - void *value; +}; + +struct cds_lfht_node { + /* cache-hot for iteration */ + struct _cds_lfht_node p; /* needs to be first field */ + void *key; + unsigned int key_len; + /* cache-cold for iteration */ struct rcu_head head; }; -struct rcu_ht; +struct cds_lfht; /* * Caution ! * Ensure reader and writer threads are registered as urcu readers. */ -typedef unsigned long (*ht_hash_fct)(void *hashseed, void *key); +typedef unsigned long (*cds_lfht_hash_fct)(void *key, size_t length, + unsigned long seed); +typedef unsigned long (*cds_lfht_compare_fct)(void *key1, size_t key1_len, + void *key2, size_t key2_len); +/* + * cds_lfht_node_init - initialize a hash table node + */ static inline -void ht_node_init(struct rcu_ht_node *node, void *key, void *value) +void cds_lfht_node_init(struct cds_lfht_node *node, void *key, + size_t key_len) { node->key = key; - node->value = value; - node->dummy = 0; + node->key_len = key_len; } /* + * Hash table creation flags. + */ +enum { + CDS_LFHT_AUTO_RESIZE = (1U << 0), +}; + +/* + * cds_lfht_new - allocate a hash table. + * * init_size must be power of two. + * Return NULL on error. + */ +struct cds_lfht *cds_lfht_new(cds_lfht_hash_fct hash_fct, + cds_lfht_compare_fct compare_fct, + unsigned long hash_seed, + unsigned long init_size, + int flags, + void (*cds_lfht_call_rcu)(struct rcu_head *head, + void (*func)(struct rcu_head *head)), + void (*cds_lfht_synchronize_rcu)(void), + void (*cds_lfht_rcu_read_lock)(void), + void (*cds_lfht_rcu_read_unlock)(void)); + +/* + * cds_lfht_destroy - destroy a hash table. + * + * Return 0 on success, negative error value on error. */ -struct rcu_ht *ht_new(ht_hash_fct hash_fct, - void *hashseed, - unsigned long init_size, - void (*ht_call_rcu)(struct rcu_head *head, - void (*func)(struct rcu_head *head))); +int cds_lfht_destroy(struct cds_lfht *ht); -int ht_destroy(struct rcu_ht *ht); +/* + * cds_lfht_count_nodes - count the number of nodes in the hash table. + * + * Call with rcu_read_lock held. + */ +void cds_lfht_count_nodes(struct cds_lfht *ht, + unsigned long *count, + unsigned long *removed); -/* Call with rcu_read_lock held. */ -struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key); +/* + * cds_lfht_lookup - lookup a node by key. + * + * Return NULL if not found. + * Call with rcu_read_lock held. + */ +struct cds_lfht_node *cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len); -/* Call with rcu_read_lock held. */ -void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node); +/* + * cds_lfht_next - get the next item with same key (after a lookup). + * + * Return NULL if no following node exists with same key. + * RCU read-side lock must be held across cds_lfht_lookup and cds_lfht_next calls, and also + * between cds_lfht_next calls using the node returned by a previous cds_lfht_next. + * Call with rcu_read_lock held. + */ +struct cds_lfht_node *cds_lfht_next(struct cds_lfht *ht, struct cds_lfht_node *node); -/* Call with rcu_read_lock held. */ -int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node); +/* + * cds_lfht_add - add a node to the hash table. + * + * Call with rcu_read_lock held. + */ +void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node); -void ht_resize(struct rcu_ht *ht, int growth); +/* + * cds_lfht_add_unique - add a node to hash table, if key is not present. + * + * Return the node added upon success. + * Return the unique node already present upon failure. If cds_lfht_add_unique fails, + * the node passed as parameter should be freed by the caller. + * Call with rcu_read_lock held. + */ +struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht, struct cds_lfht_node *node); + +/* + * cds_lfht_remove - remove node from hash table. + * + * Node can be looked up with cds_lfht_lookup. RCU read-side lock must be held between + * lookup and removal. + * Call with rcu_read_lock held. + */ +int cds_lfht_remove(struct cds_lfht *ht, struct cds_lfht_node *node); + +/* + * cds_lfht_resize - Force a hash table resize + * @new_size: update to this hash table size. + */ +void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size); + +#ifdef __cplusplus +} +#endif #endif /* _URCU_RCULFHASH_H */