X-Git-Url: https://git.lttng.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Frculfhash.h;h=f4f3373298492b3dee1e71f35277a310af735dd7;hp=1376b5a0b4e2b4fb0fe70378f9bc91644a845027;hb=5f74363e048fb82d7ad97a780eadbeb063840787;hpb=a4ce4f122a4e615b6426fa876df38f5c3ea5fb8a

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 1376b5a..f4f3373 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -37,12 +37,22 @@ extern "C" {
  * 4-bytes boundaries because the two lower bits are used as flags.
  */
 
+/*
+ * _cds_lfht_node: Contains the internal pointers and reverse-hash
+ * value required for lookup and traversal of the hash table.
+ */
 struct _cds_lfht_node {
 	struct cds_lfht_node *next;	/* ptr | DUMMY_FLAG | REMOVED_FLAG */
 	unsigned long reverse_hash;
 } __attribute__((aligned(4)));
 
 /*
+ * cds_lfht_node: Contains the full key and length required to check for
+ * an actual match, and also contains an rcu_head structure that is used
+ * by RCU to track a node through a given RCU grace period.  There is an
+ * instance of _cds_lfht_node enclosed as a field within each
+ * _cds_lfht_node structure.
+ *
  * 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
  * cds_lfht_node after a lookup.
@@ -52,10 +62,9 @@ struct cds_lfht_node {
 	struct _cds_lfht_node p;          /* needs to be first field */
 	void *key;
 	unsigned int key_len;
-	/* cache-cold for iteration */
-	struct rcu_head head;
 };
 
+/* cds_lfht_iter: Used to track state while traversing a hash chain. */
 struct cds_lfht_iter {
 	struct cds_lfht_node *node, *next;
 };
@@ -94,6 +103,7 @@ void cds_lfht_node_init(struct cds_lfht_node *node, void *key,
  */
 enum {
 	CDS_LFHT_AUTO_RESIZE = (1U << 0),
+	CDS_LFHT_ACCOUNTING = (1U << 1),
 };
 
 /*
@@ -103,6 +113,7 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct,
 			cds_lfht_compare_fct compare_fct,
 			unsigned long hash_seed,
 			unsigned long init_size,
+			unsigned long min_alloc_size,
 			int flags,
 			void (*cds_lfht_call_rcu)(struct rcu_head *head,
 				void (*func)(struct rcu_head *head)),
@@ -121,6 +132,7 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct,
  * @compare_fct: the key comparison function.
  * @hash_seed: the seed for hash function.
  * @init_size: number of nodes to allocate initially. Must be power of two.
+ * @min_alloc_size: the smallest allocation size to use. Must be power of two.
  * @flags: hash table creation flags (can be combined with bitwise or: '|').
  *           0: no flags.
  *           CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
@@ -143,11 +155,12 @@ struct cds_lfht *cds_lfht_new(cds_lfht_hash_fct hash_fct,
 			cds_lfht_compare_fct compare_fct,
 			unsigned long hash_seed,
 			unsigned long init_size,
+			unsigned long min_alloc_size,
 			int flags,
 			pthread_attr_t *attr)
 {
 	return _cds_lfht_new(hash_fct, compare_fct, hash_seed,
-			init_size, flags,
+			init_size, min_alloc_size, flags,
 			call_rcu, synchronize_rcu, rcu_read_lock,
 			rcu_read_unlock, rcu_thread_offline,
 			rcu_thread_online, rcu_register_thread,
@@ -159,7 +172,8 @@ struct cds_lfht *cds_lfht_new(cds_lfht_hash_fct hash_fct,
  * @ht: the hash table to destroy.
  * @attr: (output) resize worker thread attributes, as received by cds_lfht_new.
  *        The caller will typically want to free this pointer if dynamically
- *        allocated.
+ *        allocated. The attr point can be NULL if the caller does not
+ *        need to be informed of the value passed to cds_lfht_new().
  *
  * Return 0 on success, negative error value on error.
  * Threads calling this API need to be registered RCU read-side threads.
@@ -168,15 +182,19 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
 
 /*
  * cds_lfht_count_nodes - count the number of nodes in the hash table.
- *
+ * @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.
  * Threads calling this API need to be registered RCU read-side threads.
  */
 void cds_lfht_count_nodes(struct cds_lfht *ht,
-		long *approx_before,
+		long *split_count_before,
 		unsigned long *count,
 		unsigned long *removed,
-		long *approx_after);
+		long *split_count_after);
 
 /*
  * cds_lfht_lookup - lookup a node by key.