X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=urcu%2Frculfhash.h;h=8ee9bdd9ebd9eb368e139b26a3ab51d167d8ea99;hb=f0c29ed7ca7129056f5c757a9fbcbbfa8c14da44;hp=d989221ae889c6726672dcb8e1f95023fa7c1586;hpb=a42cc6594389e8f88cc49e36a7779afdb6529135;p=urcu.git

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index d989221..8ee9bdd 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -1,38 +1,157 @@
 #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 */