X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=rculfhash.c;h=a3223f37f046021cb6c3c0119e107e2e4dde4fd0;hp=11c0077977f327e5437a13d050f8eceb6e7a6a6b;hb=848d408839fe4f829db477644c776eba166a0e9a;hpb=49c2e2d66ea7a3c0012343d89723fd608e877024

diff --git a/rculfhash.c b/rculfhash.c
index 11c0077..a3223f3 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -67,6 +67,7 @@ struct rcu_ht {
 	ht_compare_fct compare_fct;
 	unsigned long hash_seed;
 	pthread_mutex_t resize_mutex;	/* resize mutex: add/del mutex */
+	unsigned int in_progress_resize;
 	void (*ht_call_rcu)(struct rcu_head *head,
 		      void (*func)(struct rcu_head *head));
 };
@@ -234,14 +235,16 @@ void _ht_gc_bucket(struct rcu_ht_node *dummy, struct rcu_ht_node *node)
 }
 
 static
-int _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node,
-	     int unique)
+struct rcu_ht_node *_ht_add(struct rcu_ht *ht, struct rcu_table *t,
+			    struct rcu_ht_node *node, int unique)
 {
 	struct rcu_ht_node *iter_prev, *dummy, *iter, *next;
 	unsigned long hash;
 
-	if (!t->size)
-		return 0;
+	if (!t->size) {
+		assert(node->dummy);
+		return node;	/* Initial first add (head) */
+	}
 	hash = bit_reverse_ulong(node->reverse_hash);
 	for (;;) {
 		uint32_t chain_len = 0;
@@ -262,6 +265,12 @@ int _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node,
 			next = rcu_dereference(clear_flag(iter)->next);
 			if (is_removed(next))
 				goto gc_node;
+			if (unique
+			    && !clear_flag(iter)->dummy
+			    && !ht->compare_fct(node->key, node->key_len,
+						clear_flag(iter)->key,
+						clear_flag(iter)->key_len))
+				return clear_flag(iter);
 			/* Only account for identical reverse hash once */
 			if (iter_prev->reverse_hash != clear_flag(iter)->reverse_hash)
 				check_resize(ht, t, ++chain_len);
@@ -287,7 +296,7 @@ gc_end:
 	/* Garbage collect logically removed nodes in the bucket */
 	dummy = rcu_dereference(t->tbl[hash & (t->size - 1)]);
 	_ht_gc_bucket(dummy, node);
-	return 0;
+	return node;
 }
 
 static
@@ -365,6 +374,7 @@ struct rcu_ht *ht_new(ht_hash_fct hash_fct,
 	ht->compare_fct = compare_fct;
 	ht->hash_seed = hash_seed;
 	ht->ht_call_rcu = ht_call_rcu;
+	ht->in_progress_resize = 0;
 	/* this mutex should not nest in read-side C.S. */
 	pthread_mutex_init(&ht->resize_mutex, NULL);
 	ht->t = calloc(1, sizeof(struct rcu_table)
@@ -417,7 +427,7 @@ void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node)
 	(void) _ht_add(ht, t, node, 0);
 }
 
-int ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node)
+struct rcu_ht_node *ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node)
 {
 	struct rcu_table *t;
 	unsigned long hash;
@@ -469,6 +479,9 @@ int ht_destroy(struct rcu_ht *ht)
 {
 	int ret;
 
+	/* Wait for in-flight resize operations to complete */
+	while (uatomic_read(&ht->in_progress_resize))
+		poll(NULL, 0, 100);	/* wait for 100ms */
 	ret = ht_delete_dummy(ht);
 	if (ret)
 		return ret;
@@ -568,6 +581,8 @@ void do_resize_cb(struct rcu_head *head)
 	_do_ht_resize(ht);
 	pthread_mutex_unlock(&ht->resize_mutex);
 	free(work);
+	cmm_smp_mb();	/* finish resize before decrement */
+	uatomic_dec(&ht->in_progress_resize);
 }
 
 static
@@ -578,6 +593,8 @@ void ht_resize_lazy(struct rcu_ht *ht, struct rcu_table *t, int growth)
 
 	target_size = resize_target_update(t, growth);
 	if (!CMM_LOAD_SHARED(t->resize_initiated) && t->size < target_size) {
+		uatomic_inc(&ht->in_progress_resize);
+		cmm_smp_mb();	/* increment resize count before calling it */
 		work = malloc(sizeof(*work));
 		work->ht = ht;
 		ht->ht_call_rcu(&work->head, do_resize_cb);