assert(size > 0);
index = hash & (size - 1);
- order = get_count_order_ulong(index + 1);
+ /*
+ * equivalent to get_count_order_ulong(index + 1), but optimizes
+ * away the non-existing 0 special-case for
+ * get_count_order_ulong.
+ */
+ order = fls_ulong(index);
dbg_printf("lookup hash %lu index %lu order %lu aridx %lu\n",
hash, index, order, index & (!order ? 0 : ((1UL << (order - 1)) - 1)));
static
int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
struct cds_lfht_node *old_node,
- struct cds_lfht_node *ret_next,
+ struct cds_lfht_node *old_next,
struct cds_lfht_node *new_node)
{
- struct cds_lfht_node *dummy, *old_next;
+ struct cds_lfht_node *dummy, *ret_next;
struct _cds_lfht_node *lookup;
int flagged = 0;
assert(!is_removed(new_node));
assert(!is_dummy(new_node));
assert(new_node != old_node);
- do {
+ for (;;) {
/* Insert after node to be replaced */
- old_next = ret_next;
if (is_removed(old_next)) {
/*
* Too late, the old node has been removed under us
*/
ret_next = uatomic_cmpxchg(&old_node->p.next,
old_next, flag_removed(new_node));
- } while (ret_next != old_next);
+ if (ret_next == old_next)
+ break;
+ old_next = ret_next;
+ }
/* We performed the replacement. */
flagged = 1;
enum add_mode mode, int dummy)
{
struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next,
- *dummy_node, *return_node;
+ *return_node;
struct _cds_lfht_node *lookup;
assert(!is_dummy(node));
goto insert;
if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash))
goto insert;
+ /* dummy node is the first node of the identical-hash-value chain */
+ if (dummy && clear_flag(iter)->p.reverse_hash == node->p.reverse_hash)
+ goto insert;
next = rcu_dereference(clear_flag(iter)->p.next);
if (unlikely(is_removed(next)))
goto gc_node;
if ((mode == ADD_UNIQUE || mode == ADD_REPLACE)
&& !is_dummy(next)
+ && clear_flag(iter)->p.reverse_hash == node->p.reverse_hash
&& !ht->compare_fct(node->key, node->key_len,
clear_flag(iter)->key,
clear_flag(iter)->key_len)) {
return_node = NULL;
else /* ADD_DEFAULT and ADD_UNIQUE */
return_node = node;
- goto gc_end;
+ goto end;
}
replace:
(void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next);
/* retry */
}
-gc_end:
- /* Garbage collect logically removed nodes in the bucket */
- dummy_node = (struct cds_lfht_node *) lookup;
- _cds_lfht_gc_bucket(dummy_node, node);
end:
return return_node;
}
next = rcu_dereference(node->p.next);
if (likely(!is_removed(next))
&& !is_dummy(next)
+ && clear_flag(node)->p.reverse_hash == reverse_hash
&& likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) {
break;
}