rculfhash: merge dummy into next ptr

part 2: rely on the flag for check.

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

diff --git a/rculfhash.c b/rculfhash.c
index 86b93b2aa54914f3bb9f6d0cec46dd8f2098c564..55f56ceb6bc54a248032d3e2ce94e2db1bfeb82b 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -263,7 +263,6 @@ struct rcu_ht_node *_ht_add(struct rcu_ht *ht, struct rcu_table *t,
        unsigned long hash;
 
        if (!t->size) {
-               assert(node->p.dummy);
                assert(dummy);
                node->p.next = flag_dummy(NULL);
                return node;    /* Initial first add (head) */
@@ -289,7 +288,7 @@ struct rcu_ht_node *_ht_add(struct rcu_ht *ht, struct rcu_table *t,
                        if (is_removed(next))
                                goto gc_node;
                        if (unique
-                           && !clear_flag(iter)->p.dummy
+                           && !is_dummy(next)
                            && !ht->compare_fct(node->key, node->key_len,
                                                clear_flag(iter)->key,
                                                clear_flag(iter)->key_len))
@@ -305,9 +304,9 @@ struct rcu_ht_node *_ht_add(struct rcu_ht *ht, struct rcu_table *t,
                assert(!is_removed(iter_prev));
                assert(iter_prev != node);
                if (!dummy)
-                       node->p.next = iter;
+                       node->p.next = clear_flag(iter);
                else
-                       node->p.next = flag_dummy(iter);
+                       node->p.next = flag_dummy(clear_flag(iter));
                if (is_dummy(iter))
                        new_node = flag_dummy(node);
                else
@@ -346,7 +345,7 @@ int _ht_remove(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
                next = old;
                if (is_removed(next))
                        goto end;
-               assert(!node->p.dummy);
+               assert(!is_dummy(next));
                old = uatomic_cmpxchg(&node->p.next, next,
                                      flag_removed(next));
        } while (old != next);
@@ -386,7 +385,6 @@ void init_table(struct rcu_ht *ht, struct rcu_table *t,
                if (i != 0 && !(i & (i - 1)))
                        t->size = i;
                t->tbl[i] = calloc(1, sizeof(struct _rcu_ht_node));
-               t->tbl[i]->p.dummy = 1;
                t->tbl[i]->p.reverse_hash = bit_reverse_ulong(i);
                (void) _ht_add(ht, t, t->tbl[i], 0, 1);
        }
@@ -423,7 +421,7 @@ struct rcu_ht *ht_new(ht_hash_fct hash_fct,
 struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len)
 {
        struct rcu_table *t;
-       struct rcu_ht_node *node;
+       struct rcu_ht_node *node, *next;
        unsigned long hash, reverse_hash;
 
        hash = ht->hash_fct(key, key_len, ht->hash_seed);
@@ -438,14 +436,15 @@ struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len)
                        node = NULL;
                        break;
                }
-               if (likely(!is_removed(rcu_dereference(node->p.next)))
-                   && !node->p.dummy
+               next = rcu_dereference(node->p.next);
+               if (likely(!is_removed(next))
+                   && !is_dummy(next)
                    && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) {
                                break;
                }
-               node = clear_flag(rcu_dereference(node->p.next));
+               node = clear_flag(next);
        }
-       assert(!node || !node->p.dummy);
+       assert(!node || !is_dummy(rcu_dereference(node->p.next)));
        return node;
 }
 
@@ -492,14 +491,14 @@ int ht_delete_dummy(struct rcu_ht *ht)
        /* Check that the table is empty */
        node = t->tbl[0];
        do {
-               if (!node->p.dummy)
+               node = clear_flag(node)->p.next;
+               if (!is_dummy(node))
                        return -EPERM;
-               node = node->p.next;
                assert(!is_removed(node));
        } while (clear_flag(node));
        /* Internal sanity check: all nodes left should be dummy */
        for (i = 0; i < t->size; i++) {
-               assert(t->tbl[i]->p.dummy);
+               assert(is_dummy(t->tbl[i]->p.next));
                free(t->tbl[i]);
        }
        return 0;
@@ -540,9 +539,9 @@ void ht_count_nodes(struct rcu_ht *ht,
        do {
                next = rcu_dereference(node->p.next);
                if (is_removed(next)) {
-                       assert(!node->p.dummy);
+                       assert(!is_dummy(next));
                        (*removed)++;
-               } else if (!node->p.dummy)
+               } else if (!is_dummy(next))
                        (*count)++;
                node = clear_flag(next);
        } while (node);

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 99b43a8ba0ec4b178b60f1e9491b7176a3204f1f..5c5d4eb1a57ad87a0b2ec8f7c10ed704efd6b66f 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -11,7 +11,6 @@ extern "C" {
 struct _rcu_ht_node {
        struct rcu_ht_node *next;
        unsigned long reverse_hash;
-       unsigned int dummy;
 };
 
 struct rcu_ht_node {
@@ -41,7 +40,6 @@ void ht_node_init(struct rcu_ht_node *node, void *key,
 {
        node->key = key;
        node->key_len = key_len;
-       node->p.dummy = 0;
 }
 
 /*