From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sun, 19 Aug 2012 13:28:53 +0000 (-0400)
Subject: rcuja: create shadow node for root
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=b0f74e4734295f71a2c311817c0082223f2564d8;p=userspace-rcu.git

rcuja: create shadow node for root

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

diff --git a/rcuja/rcuja-internal.h b/rcuja/rcuja-internal.h
index 28908e0..0277808 100644
--- a/rcuja/rcuja-internal.h
+++ b/rcuja/rcuja-internal.h
@@ -43,6 +43,7 @@ struct cds_ja_shadow_node {
 	pthread_mutex_t *lock;
 	unsigned int nr_child;		/* number of children in node */
 	struct rcu_head head;		/* for deferred node and shadow node reclaim */
+	int is_root;			/* is it a root node ? */
 };
 
 struct cds_ja {
diff --git a/rcuja/rcuja.c b/rcuja/rcuja.c
index 1c1d6e4..945b299 100644
--- a/rcuja/rcuja.c
+++ b/rcuja/rcuja.c
@@ -876,7 +876,8 @@ int cds_ja_add(struct cds_ja *ja, uint64_t key,
 retry:
 	iter_key = key;
 	parent2_node_flag = NULL;
-	parent_node_flag = NULL;
+	parent_node_flag =
+		(struct cds_ja_inode_flag *) &ja->root;	/* Use root ptr address as key for mutex */
 	node_flag_ptr = &ja->root;
 	node_flag = rcu_dereference(*node_flag_ptr);
 
@@ -921,6 +922,7 @@ struct cds_ja *_cds_ja_new(unsigned int key_bits,
 		const struct rcu_flavor_struct *flavor)
 {
 	struct cds_ja *ja;
+	int ret;
 
 	ja = calloc(sizeof(*ja), 1);
 	if (!ja)
@@ -950,8 +952,21 @@ struct cds_ja *_cds_ja_new(unsigned int key_bits,
 	ja->ht = rcuja_create_ht(flavor);
 	if (!ja->ht)
 		goto ht_error;
+
+	/*
+	 * Note: we should not free this node until judy array destroy.
+	 */
+	ret = rcuja_shadow_set(ja->ht,
+			ja_node_ptr((struct cds_ja_inode_flag *) &ja->root),
+			NULL);
+	if (ret)
+		goto ht_node_error;
+
 	return ja;
 
+ht_node_error:
+	ret = rcuja_delete_ht(ja->ht);
+	assert(!ret);
 ht_error:
 check_error:
 	free(ja);