* cds_lfht_node: Contains the next pointers and reverse-hash
* value required for lookup and traversal of the hash table.
*
- * struct cds_lfht_node should be aligned on 4-bytes boundaries because
- * the two lower bits are used as flags.
+ * struct cds_lfht_node should be aligned on 8-bytes boundaries because
+ * the three lower bits are used as flags. It is worth noting that the
+ * information contained within these three bits could be represented on
+ * two bits by re-using the same bit for REMOVAL_OWNER_FLAG and
+ * BUCKET_FLAG. This can be done if we ensure that no iterator nor
+ * updater check the BUCKET_FLAG after it detects that the REMOVED_FLAG
+ * is set. Given the minimum size of struct cds_lfht_node is 8 bytes on
+ * 32-bit architectures, we choose to go for simplicity and reserve
+ * three bits.
*
* struct cds_lfht_node can be embedded into a structure (as a field).
* caa_container_of() can be used to get the structure from the struct
* of the hash value for cds_lfht APIs.
*/
struct cds_lfht_node {
- struct cds_lfht_node *next; /* ptr | BUCKET_FLAG | REMOVED_FLAG */
+ struct cds_lfht_node *next; /* ptr | REMOVAL_OWNER_FLAG | BUCKET_FLAG | REMOVED_FLAG */
unsigned long reverse_hash;
-} __attribute__((aligned(4)));
+} __attribute__((aligned(8)));
/* cds_lfht_iter: Used to track state while traversing a hash chain. */
struct cds_lfht_iter {
};
extern const struct cds_lfht_mm_type cds_lfht_mm_order;
+extern const struct cds_lfht_mm_type cds_lfht_mm_chunk;
+extern const struct cds_lfht_mm_type cds_lfht_mm_mmap;
/*
* _cds_lfht_new - API used by cds_lfht_new wrapper. Do not use directly.
pthread_attr_t *attr)
{
return _cds_lfht_new(init_size, min_nr_alloc_buckets, max_nr_buckets,
- flags, &cds_lfht_mm_order, &rcu_flavor, attr);
+ flags, NULL, &rcu_flavor, attr);
}
/*
* @ht: the hash table.
* @split_count_before: Sample the node count split-counter before traversal.
* @count: Traverse the hash table, count the number of nodes observed.
- * @removed: Number of logically removed nodes observed during traversal.
* @split_count_after: Sample the node count split-counter after traversal.
*
* Call with rcu_read_lock held.
void cds_lfht_count_nodes(struct cds_lfht *ht,
long *split_count_before,
unsigned long *count,
- unsigned long *removed,
long *split_count_after);
/*
* @key: the current node key.
* @iter: Node, if found (output). *iter->node set to NULL if not found.
*
- * Uses an iterator initialized by a lookup.
+ * Uses an iterator initialized by a lookup. Important: the iterator
+ * _needs_ to be initialized before calling cds_lfht_next_duplicate.
* Sets *iter-node to the following node with same key.
* Sets *iter->node to NULL if no following node exists with same key.
* RCU read-side lock must be held across cds_lfht_lookup and
struct cds_lfht_node *node);
/*
- * cds_lfht_replace - replace a node pointer to by iter within hash table.
+ * cds_lfht_replace - replace a node pointed to by iter within hash table.
* @ht: the hash table.
* @old_iter: the iterator position of the node to replace.
- * @now_node: the new node to try using for replacement.
+ * @hash: the node's hash.
+ * @match: the key match function.
+ * @key: the node's key.
+ * @new_node: the new node to use as replacement.
*
* Return 0 if replacement is successful, negative value otherwise.
- * Replacing a NULL old node or an already removed node will fail with a
- * negative value.
+ * Replacing a NULL old node or an already removed node will fail with
+ * -ENOENT.
+ * If the hash or value of the node to replace and the new node differ,
+ * this function returns -EINVAL without proceeding to the replacement.
* Old node can be looked up with cds_lfht_lookup and cds_lfht_next.
* RCU read-side lock must be held between lookup and replacement.
* Call with rcu_read_lock held.
* guarantee that a combination of add_replace and add_unique updates
* will never generate duplicated keys.
*/
-int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
+int cds_lfht_replace(struct cds_lfht *ht,
+ struct cds_lfht_iter *old_iter,
+ unsigned long hash,
+ cds_lfht_match_fct match,
+ const void *key,
struct cds_lfht_node *new_node);
/*
* cds_lfht_del - remove node pointed to by iterator from hash table.
* @ht: the hash table.
- * @iter: the iterator position of the node to delete.
+ * @node: the node to delete.
*
* Return 0 if the node is successfully removed, negative value
* otherwise.
- * Replacing a NULL node or an already removed node will fail with a
+ * Deleting a NULL node or an already removed node will fail with a
* negative value.
- * Node can be looked up with cds_lfht_lookup and cds_lfht_next.
- * cds_lfht_iter_get_node.
+ * Node can be looked up with cds_lfht_lookup and cds_lfht_next,
+ * followed by use of cds_lfht_iter_get_node.
* RCU read-side lock must be held between lookup and removal.
* Call with rcu_read_lock held.
* Threads calling this API need to be registered RCU read-side threads.
* freeing the memory reserved for old node (which can be accessed with
* cds_lfht_iter_get_node).
*/
-int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter);
+int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_node *node);
+
+/*
+ * cds_lfht_is_node_deleted - query if a node is removed from hash table.
+ *
+ * Return non-zero if the node is deleted from the hash table, 0
+ * otherwise.
+ * Node can be looked up with cds_lfht_lookup and cds_lfht_next,
+ * followed by use of cds_lfht_iter_get_node.
+ * RCU read-side lock must be held between lookup and call to this
+ * function.
+ * Call with rcu_read_lock held.
+ * Threads calling this API need to be registered RCU read-side threads.
+ */
+int cds_lfht_is_node_deleted(struct cds_lfht_node *node);
/*
* cds_lfht_resize - Force a hash table resize