X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=urcu%2Frcuja.h;h=637366778d0ff1e664723e3ff2e006d50f171b22;hb=170e11866c8a4bb6c3b2bf0a1e86e8b60a44059b;hp=f8cba6af4da08fb5ba0aa7a0a1d46d8c3f16e377;hpb=03ec1aebe1d8eaa2b03a12b501e5b988efc0a6d0;p=userspace-rcu.git

diff --git a/urcu/rcuja.h b/urcu/rcuja.h
index f8cba6a..6373667 100644
--- a/urcu/rcuja.h
+++ b/urcu/rcuja.h
@@ -6,7 +6,7 @@
  *
  * Userspace RCU library - RCU Judy Array
  *
- * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2012-2013 - 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
@@ -58,40 +58,169 @@ void cds_ja_node_init(struct cds_ja_node *node)
 {
 }
 
+/*
+ * cds_ja_lookup - look up by key.
+ * @ja: the Judy array.
+ * @key: key to look up.
+ *
+ * Returns the first node of a duplicate chain if a match is found, else
+ * returns NULL.
+ * A RCU read-side lock should be held across call to this function and
+ * use of its return value.
+ */
 struct cds_ja_node *cds_ja_lookup(struct cds_ja *ja, uint64_t key);
-struct cds_ja_node *cds_ja_lookup_lower_equal(struct cds_ja *ja,
-		uint64_t key);
 
+/*
+ * cds_ja_lookup_below_equal - look up first node with key <= @key.
+ * @ja: the Judy array.
+ * @key: key to look up.
+ * @result_key: key found.
+ *
+ * Returns the first node of a duplicate chain if a node is present in
+ * the tree which has a key below or equal to @key, else returns NULL.
+ * A RCU read-side lock should be held across call to this function and
+ * use of its return value.
+ */
+struct cds_ja_node *cds_ja_lookup_below_equal(struct cds_ja *ja,
+		uint64_t key, uint64_t *result_key);
+
+/*
+ * cds_ja_lookup_above_equal - look up first node with key >= @key.
+ * @ja: the Judy array.
+ * @key: key to look up.
+ * @result_key: key found.
+ *
+ * Returns the first node of a duplicate chain if a node is present in
+ * the tree which has a key above or equal to @key, else returns NULL.
+ * A RCU read-side lock should be held across call to this function and
+ * use of its return value.
+ */
+struct cds_ja_node *cds_ja_lookup_above_equal(struct cds_ja *ja,
+		uint64_t key, uint64_t *result_key);
+
+/*
+ * cds_ja_add - Add @node at @key, allowing duplicates.
+ * @ja: the Judy array.
+ * @key: key at which @node should be added.
+ * @node: node to add.
+ *
+ * Returns 0 on success, negative error value on error.
+ * A RCU read-side lock should be held across call to this function.
+ */
 int cds_ja_add(struct cds_ja *ja, uint64_t key,
-		struct cds_ja_node *new_node);
+		struct cds_ja_node *node);
 
+/*
+ * cds_ja_add_unique - Add @node at @key, without duplicates.
+ * @ja: the Judy array.
+ * @key: key at which @node should be added.
+ * @node: node to add.
+ *
+ * Returns @node if successfully added, else returns the already
+ * existing node (acts as a RCU lookup).
+ * A RCU read-side lock should be held across call to this function and
+ * use of its return value.
+ */
 struct cds_ja_node *cds_ja_add_unique(struct cds_ja *ja, uint64_t key,
-		struct cds_ja_node *new_node);
+		struct cds_ja_node *node);
 
+/*
+ * cds_ja_del - Remove @node at @key.
+ * @ja: the Judy array.
+ * @key: key at which @node is expected.
+ * @node: node to remove.
+ *
+ * Returns 0 on success, negative error value on error.
+ * A RCU read-side lock should be held across call to this function.
+ */
 int cds_ja_del(struct cds_ja *ja, uint64_t key,
 		struct cds_ja_node *node);
 
 struct cds_ja *_cds_ja_new(unsigned int key_bits,
 		const struct rcu_flavor_struct *flavor);
 
+/*
+ * cds_ja_new - Create a Judy array.
+ * @key_bits: Number of bits for key.
+ *
+ * Returns non-NULL pointer on success, else NULL on error. @key_bits
+ * needs to be multiple of 8, either: 8, 16, 24, 32, 40, 48, 56, or 64.
+ */
 static inline
 struct cds_ja *cds_ja_new(unsigned int key_bits)
 {
 	return _cds_ja_new(key_bits, &rcu_flavor);
 }
 
-int cds_ja_destroy(struct cds_ja *ja,
-		void (*rcu_free_node_cb)(struct cds_ja_node *node));
+/*
+ * cds_ja_destroy - Destroy a Judy array.
+ * @ja: the Judy array.
+ *
+ * Returns 0 on success, negative error value on error.
+ * There should be no more concurrent add, delete, nor look-up performed
+ * on the Judy array while it is being destroyed (ensured by the caller).
+ * RCU read-side lock should _not_ be held when calling this function,
+ * however, QSBR threads need to be online.
+ */
+int cds_ja_destroy(struct cds_ja *ja);
 
 /*
+ * cds_ja_for_each_duplicate_rcu: Iterate through duplicates.
+ * @pos: struct cds_ja_node *, start of duplicate list and loop cursor.
+ *
  * Iterate through duplicates returned by cds_ja_lookup*()
  * This must be done while rcu_read_lock() is held.
  * Receives a struct cds_ja_node * as parameter, which is used as start
  * of duplicate list and loop cursor.
+ * _NOT_ safe against node removal within iteration.
  */
-#define cds_ja_for_each_duplicate_rcu(pos)				\
+#define cds_ja_for_each_duplicate_rcu(pos)					\
 	for (; (pos) != NULL; (pos) = rcu_dereference((pos)->next))
 
+/*
+ * cds_ja_for_each_duplicate_safe: Iterate through duplicates.
+ * @pos: struct cds_ja_node *, start of duplicate list and loop cursor.
+ * @p: struct cds_ja_node *, temporary pointer to next.
+ *
+ * Iterate through duplicates returned by cds_ja_lookup*().
+ * Safe against node removal within iteration.
+ * This must be done while rcu_read_lock() is held.
+ */
+#define cds_ja_for_each_duplicate_safe_rcu(pos, p)			\
+	for (; (pos) != NULL ?						\
+			((p) = rcu_dereference((pos)->next), 1) : 0;	\
+			(pos) = (p))
+
+/*
+ * cds_ja_for_each_key_rcu: Iterate over all keys in ascending order.
+ * @ja: Judy array on which iteration should be done.
+ * @key: Key cursor, needs to be a uint64_t.
+ * @pos: struct cds_ja_node *, used as loop cursor.
+ *
+ * Iterate over all keys of a RCU Judy array (_not_ duplicates) in
+ * ascending order.
+ * This must be done while rcu_read_lock() is held.
+ * Safe against node removal during iteration.
+ */
+#define cds_ja_for_each_key_rcu(ja, key, pos)				\
+	for ((key) = 0;							\
+		((pos) = cds_ja_lookup_above_equal(ja, key, &(key))); )
+
+/*
+ * cds_ja_for_each_key_prev_rcu: Iterate over all keys in descending order.
+ * @ja: Judy array on which iteration should be done.
+ * @key: Key cursor, needs to be a uint64_t.
+ * @pos: struct cds_ja_node *, used as loop cursor.
+ *
+ * Iterate over all keys of a RCU Judy array (_not_ duplicates) in
+ * descending order.
+ * This must be done while rcu_read_lock() is held.
+ * Safe against node removal during iteration.
+ */
+#define cds_ja_for_each_key_prev_rcu(ja, key, pos)			\
+	for ((key) = UINT64_MAX;					\
+		((pos) = cds_ja_lookup_below_equal(ja, key, &(key))); )
+
 #ifdef __cplusplus
 }
 #endif