#ifndef _URCU_RCULFHASH_H
#define _URCU_RCULFHASH_H
+/*
+ * urcu/rculfhash.h
+ *
+ * Userspace RCU library - Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * 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 <stdint.h>
+#include <urcu-call-rcu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * struct rcu_ht_node and struct _rcu_ht_node should be aligned on
+ * 4-bytes boundaries because the two lower bits are used as flags.
+ */
+
+struct _rcu_ht_node {
+ struct rcu_ht_node *next; /* ptr | DUMMY_FLAG | REMOVED_FLAG */
+ unsigned long reverse_hash;
+};
+
+struct rcu_ht_node {
+ /* cache-hot for iteration */
+ struct _rcu_ht_node p; /* needs to be first field */
+ void *key;
+ unsigned int key_len;
+ /* cache-cold for iteration */
+ struct rcu_head head;
+};
+
+struct rcu_ht;
/*
* Caution !
- * Ensure writer threads are registered as urcu readers and with with
- * urcu-defer.
- * Ensure reader threads are registered as urcu readers.
+ * Ensure reader and writer threads are registered as urcu readers.
*/
-typedef uint32_t (*ht_hash_fct)(void *key, uint32_t length, uint32_t initval);
+typedef unsigned long (*ht_hash_fct)(void *key, size_t length,
+ unsigned long seed);
+typedef unsigned long (*ht_compare_fct)(void *key1, size_t key1_len,
+ void *key2, size_t key2_len);
/*
- * init_size must be power of two.
+ * ht_node_init - initialize a hash table node
*/
-struct rcu_ht *ht_new(ht_hash_fct hash_fct, void (*free_fct)(void *data),
- unsigned long init_size, uint32_t keylen,
- uint32_t hashseed);
+static inline
+void ht_node_init(struct rcu_ht_node *node, void *key,
+ size_t key_len)
+{
+ node->key = key;
+ node->key_len = key_len;
+}
-int ht_delete_all(struct rcu_ht *ht);
+/*
+ * ht_new - allocate a hash table.
+ *
+ * init_size must be power of two.
+ */
+struct rcu_ht *ht_new(ht_hash_fct hash_fct,
+ ht_compare_fct compare_fct,
+ unsigned long hash_seed,
+ unsigned long init_size,
+ void (*ht_call_rcu)(struct rcu_head *head,
+ void (*func)(struct rcu_head *head)));
+/*
+ * ht_destroy - destroy a hash table.
+ */
int ht_destroy(struct rcu_ht *ht);
-void *ht_lookup(struct rcu_ht *ht, void *key);
+/*
+ * ht_count_nodes - count the number of nodes in the hash table.
+ *
+ * Call with rcu_read_lock held.
+ */
+void ht_count_nodes(struct rcu_ht *ht,
+ unsigned long *count,
+ unsigned long *removed);
+
+/*
+ * ht_lookup - lookup a node by key.
+ *
+ * Returns NULL if not found.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len);
+
+/*
+ * ht_next - get the next item with same key (after a lookup).
+ *
+ * Returns NULL if no following node exists with same key.
+ * RCU read-side lock must be held across ht_lookup and ht_next calls, and also
+ * between ht_next calls using the node returned by a previous ht_next.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_next(struct rcu_ht *ht, struct rcu_ht_node *node);
-int ht_add(struct rcu_ht *ht, void *key, void *data);
+/*
+ * ht_add - add a node to the hash table.
+ *
+ * Call with rcu_read_lock held.
+ */
+void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
-int ht_delete(struct rcu_ht *ht, void *key);
+/*
+ * ht_add_unique - add a node to hash table, if key is not present.
+ *
+ * Returns the node added upon success.
+ * Returns the unique node already present upon failure. If ht_add_unique fails,
+ * the node passed as parameter should be freed by the caller.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node);
-void *ht_steal(struct rcu_ht *ht, void *key);
+/*
+ * ht_remove - remove node from hash table.
+ *
+ * Node can be looked up with ht_lookup. RCU read-side lock must be held between
+ * lookup and removal.
+ * Call with rcu_read_lock held.
+ */
+int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node);
+/*
+ * ht_resize - Force a hash table resize
+ * @growth: growth order (current size is multiplied by 2^growth)
+ *
+ * Currently, only expand operation is supported (growth >= 0).
+ */
void ht_resize(struct rcu_ht *ht, int growth);
-uint32_t ht_jhash(void *key, uint32_t length, uint32_t initval);
+#ifdef __cplusplus
+}
+#endif
#endif /* _URCU_RCULFHASH_H */
projects / urcu.git / blobdiff