rculfhash: update comments in implementation

[urcu.git] / urcu / rculfhash.h

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 96dc5a023aa6d4958b24bf316269463ed114b62a..004c20817b8585e1cecc21f37068b8725b8a5d43 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -214,7 +214,8 @@ void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
  * @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
@@ -322,7 +323,7 @@ struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
                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.
  * @hash: the node's hash.
@@ -380,6 +381,20 @@ int cds_lfht_replace(struct cds_lfht *ht,
  */
 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
  * @ht: the hash table.