rculfhash: add unique

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

diff --git a/rculfhash.c b/rculfhash.c
index 534a2f8764ba8473ed896aa48a6fbc47690da4cf..a5e4d9feed5a0d3ed7ec074727cacb33f9641d23 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -205,12 +205,13 @@ unsigned long _uatomic_max(unsigned long *ptr, unsigned long v)
 }
 
 static
-void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
+int _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node,
+            int unique)
 {
        struct rcu_ht_node *iter_prev, *iter, *iter_prev_next, *next;
 
        if (!t->size)
-               return;
+               return 0;
        for (;;) {
                uint32_t chain_len = 0;
 
@@ -232,6 +233,12 @@ void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
                        next = rcu_dereference(clear_flag(iter)->next);
                        if (unlikely(is_removed(next)))
                                continue;
+                       if (unique
+                           && !clear_flag(iter)->dummy
+                           && !ht->compare_fct(node->key, node->key_len,
+                                       clear_flag(iter)->key,
+                                       clear_flag(iter)->key_len))
+                               return -EEXIST;
                        if (clear_flag(iter)->reverse_hash > node->reverse_hash)
                                break;
                        /* Only account for identical reverse hash once */
@@ -250,6 +257,7 @@ void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
                else
                        break;
        }
+       return 0;
 }
 
 static
@@ -345,7 +353,7 @@ void init_table(struct rcu_ht *ht, struct rcu_table *t,
                t->tbl[i]->dummy = 1;
                t->tbl[i]->hash = i;
                t->tbl[i]->reverse_hash = bit_reverse_ulong(i);
-               _ht_add(ht, t, t->tbl[i]);
+               (void) _ht_add(ht, t, t->tbl[i], 0);
        }
        t->resize_target = t->size = end;
        t->resize_initiated = 0;
@@ -412,7 +420,18 @@ void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node)
        node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash);
 
        t = rcu_dereference(ht->t);
-       _ht_add(ht, t, node);
+       (void) _ht_add(ht, t, node, 0);
+}
+
+int ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node)
+{
+       struct rcu_table *t;
+
+       node->hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed);
+       node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash);
+
+       t = rcu_dereference(ht->t);
+       return _ht_add(ht, t, node, 1);
 }
 
 int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node)

diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index 59356568bb2602cedea8c98e847f0a9dfe829862..44b9531b2fb8080b1a7e5bf02320669374f5bc6e 100644 (file)
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -405,9 +405,12 @@ void *thr_writer(void *_count)
                                (void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL),
                                sizeof(void *),
                                (void *) 0x42);
-                       ht_add(test_ht, node);
+                       ret = ht_add_unique(test_ht, node);
                        rcu_read_unlock();
-                       nr_add++;
+                       if (ret)
+                               nr_addexist++;
+                       else
+                               nr_add++;
                } else {
                        /* May delete */
                        rcu_read_lock();

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 94206e363bab3f9f3c5aca02e2a37cd890b7c780..ed75431f9864e08b9668e29b86f10496f8110253 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -55,6 +55,9 @@ struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len);
 /* Call with rcu_read_lock held. */
 void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
 
+/* Call with rcu_read_lock held. */
+int ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node);
+
 /* Call with rcu_read_lock held. */
 int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node);