From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 21 Dec 2011 13:16:41 +0000 (-0500)
Subject: rculfhash: number of logically removed nodes should not appear in API
X-Git-Tag: v0.7.0~43^2~9
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=caf3653dbe9dec81dc37c8e81267f27d3163dd19;p=userspace-rcu.git

rculfhash: number of logically removed nodes should not appear in API

This is an implementation artefact that should not appear in the API. So
only count the non-removed nodes. Print a debug message showing the
number of logically removed nodes instead within the count nodes
function.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/rculfhash.c b/rculfhash.c
index 8f2d8e4..f214293 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -1600,11 +1600,10 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
 void cds_lfht_count_nodes(struct cds_lfht *ht,
 		long *approx_before,
 		unsigned long *count,
-		unsigned long *removed,
 		long *approx_after)
 {
 	struct cds_lfht_node *node, *next;
-	unsigned long nr_bucket = 0;
+	unsigned long nr_bucket = 0, nr_removed = 0;
 
 	*approx_before = 0;
 	if (ht->split_count) {
@@ -1617,7 +1616,6 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
 	}
 
 	*count = 0;
-	*removed = 0;
 
 	/* Count non-bucket nodes in the table */
 	node = bucket_at(ht, 0);
@@ -1625,7 +1623,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
 		next = rcu_dereference(node->next);
 		if (is_removed(next)) {
 			if (!is_bucket(next))
-				(*removed)++;
+				(nr_removed)++;
 			else
 				(nr_bucket)++;
 		} else if (!is_bucket(next))
@@ -1634,6 +1632,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
 			(nr_bucket)++;
 		node = clear_flag(next);
 	} while (!is_end(node));
+	dbg_printf("number of logically removed nodes: %lu\n", nr_removed);
 	dbg_printf("number of bucket nodes: %lu\n", nr_bucket);
 	*approx_after = 0;
 	if (ht->split_count) {
diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index c696533..8c6f0da 100644
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -454,7 +454,7 @@ void *thr_count(void *arg)
 	rcu_register_thread();
 
 	for (;;) {
-		unsigned long count, removed;
+		unsigned long count;
 		long approx_before, approx_after;
 		ssize_t len;
 		char buf[1];
@@ -470,15 +470,15 @@ void *thr_count(void *arg)
 		printf("Counting nodes... ");
 		fflush(stdout);
 		rcu_read_lock();
-		cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
+		cds_lfht_count_nodes(test_ht, &approx_before, &count,
 				&approx_after);
 		rcu_read_unlock();
 		printf("done.\n");
 		printf("Approximation before node accounting: %ld nodes.\n",
 			approx_before);
 		printf("Accounting of nodes in the hash table: "
-			"%lu nodes + %lu logically removed.\n",
-			count, removed);
+			"%lu nodes.\n",
+			count);
 		printf("Approximation after node accounting: %ld nodes.\n",
 			approx_after);
 	}
@@ -763,7 +763,7 @@ int main(int argc, char **argv)
 	struct wr_count *count_writer;
 	unsigned long long tot_reads = 0, tot_writes = 0,
 		tot_add = 0, tot_add_exist = 0, tot_remove = 0;
-	unsigned long count, removed;
+	unsigned long count;
 	long approx_before, approx_after;
 	int i, a, ret;
 	struct sigaction act;
@@ -1086,18 +1086,17 @@ int main(int argc, char **argv)
 	rcu_thread_online();
 	rcu_read_lock();
 	printf("Counting nodes... ");
-	cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
-		&approx_after);
+	cds_lfht_count_nodes(test_ht, &approx_before, &count, &approx_after);
 	printf("done.\n");
 	test_delete_all_nodes(test_ht);
 	rcu_read_unlock();
 	rcu_thread_offline();
-	if (count || removed) {
+	if (count) {
 		printf("Approximation before node accounting: %ld nodes.\n",
 			approx_before);
 		printf("Nodes deleted from hash table before destroy: "
-			"%lu nodes + %lu logically removed.\n",
-			count, removed);
+			"%lu nodes.\n",
+			count);
 		printf("Approximation after node accounting: %ld nodes.\n",
 			approx_after);
 	}
diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index de34fae..6ea00de 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -182,7 +182,6 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
  * @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.
@@ -191,7 +190,6 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
 void cds_lfht_count_nodes(struct cds_lfht *ht,
 		long *split_count_before,
 		unsigned long *count,
-		unsigned long *removed,
 		long *split_count_after);
 
 /*