/*
* Define the minimum table size.
*/
-//#define MIN_TABLE_SIZE 128
#define MIN_TABLE_SIZE 1
#if (CAA_BITS_PER_LONG == 32)
#define FLAGS_MASK ((1UL << 2) - 1)
/* Value of the end pointer. Should not interact with flags. */
-#define END_VALUE 0x4
+#define END_VALUE NULL
struct ht_items_count {
unsigned long add, remove;
* Remove all logically deleted nodes from a bucket up to a certain node key.
*/
static
-int _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node)
+void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node)
{
struct cds_lfht_node *iter_prev, *iter, *next, *new_next;
iter_prev = dummy;
/* We can always skip the dummy node initially */
iter = rcu_dereference(iter_prev->p.next);
- if (unlikely(iter == NULL)) {
- /*
- * We are executing concurrently with a hash table
- * expand, so we see a dummy node with NULL next value.
- * Help expand by linking this node into the list and
- * retry.
- */
- return 1;
- }
assert(iter_prev->p.reverse_hash <= node->p.reverse_hash);
/*
* We should never be called with dummy (start of chain)
*/
assert(dummy != node);
for (;;) {
- assert(iter != NULL);
if (unlikely(is_end(iter)))
- return 0;
+ return;
if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash))
- return 0;
+ return;
next = rcu_dereference(clear_flag(iter)->p.next);
if (likely(is_removed(next)))
break;
new_next = flag_dummy(clear_flag(next));
else
new_next = clear_flag(next);
- assert(new_next != NULL);
(void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next);
}
- return 0;
+ return;
}
static
*dummy_node;
struct _cds_lfht_node *lookup;
unsigned long hash, index, order;
- int force_dummy = 0;
assert(!is_dummy(node));
assert(!is_removed(node));
iter_prev = (struct cds_lfht_node *) lookup;
/* We can always skip the dummy node initially */
iter = rcu_dereference(iter_prev->p.next);
- if (unlikely(iter == NULL)) {
- /*
- * We are executing concurrently with a hash table
- * expand, so we see a dummy node with NULL next value.
- * Help expand by linking this node into the list and
- * retry.
- */
- (void) _cds_lfht_add(ht, size >> 1, iter_prev, 0, 1);
- continue; /* retry */
- }
assert(iter_prev->p.reverse_hash <= node->p.reverse_hash);
for (;;) {
- assert(iter != NULL);
- /*
- * When adding a dummy node, we allow concurrent
- * add/removal to help. If we find the dummy node in
- * place, skip its insertion.
- */
- if (unlikely(dummy && clear_flag(iter) == node))
- return node;
if (unlikely(is_end(iter)))
goto insert;
if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash))
assert(!is_removed(iter_prev));
assert(!is_removed(iter));
assert(iter_prev != node);
- if (!dummy) {
+ if (!dummy)
node->p.next = clear_flag(iter);
- } else {
- /*
- * Dummy node insertion is performed concurrently (help
- * scheme). We try to link its next node, and if this
- * succeeds, it _means_ it's us who link this dummy node
- * into the table. force_dummy is set as soon as we
- * succeed this cmpxchg within this function.
- */
- if (!force_dummy) {
- if (uatomic_cmpxchg(&node->p.next, NULL,
- flag_dummy(clear_flag(iter))) != NULL) {
- return NULL;
- }
- force_dummy = 1;
- } else {
- node->p.next = flag_dummy(clear_flag(iter));
- }
- }
+ else
+ node->p.next = flag_dummy(clear_flag(iter));
if (is_dummy(iter))
new_node = flag_dummy(node);
else
new_node = node;
- assert(new_node != NULL);
if (uatomic_cmpxchg(&iter_prev->p.next, iter,
new_node) != iter)
continue; /* retry */
order = get_count_order_ulong(index + 1);
lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))];
dummy_node = (struct cds_lfht_node *) lookup;
- if (_cds_lfht_gc_bucket(dummy_node, node)) {
- /* Help expand */
- (void) _cds_lfht_add(ht, size >> 1, dummy_node, 0, 1);
- goto gc_end; /* retry */
- }
+ _cds_lfht_gc_bucket(dummy_node, node);
return node;
}
* the node, and remove it (along with any other logically removed node)
* if found.
*/
-gc_retry:
hash = bit_reverse_ulong(node->p.reverse_hash);
assert(size > 0);
index = hash & (size - 1);
order = get_count_order_ulong(index + 1);
lookup = &ht->t.tbl[order]->nodes[index & (!order ? 0 : ((1UL << (order - 1)) - 1))];
dummy = (struct cds_lfht_node *) lookup;
- if (_cds_lfht_gc_bucket(dummy, node)) {
- /* Help expand */
- (void) _cds_lfht_add(ht, size >> 1, dummy, 0, 1);
- goto gc_retry; /* retry */
- }
+ _cds_lfht_gc_bucket(dummy, node);
end:
/*
* Only the flagging action indicated that we (and no other)
/* Set all dummy nodes reverse hash values for a level */
init_table_hash(ht, i, len);
- /*
- * Update table size. At this point, concurrent add/remove see
- * dummy nodes with correctly initialized reverse hash value,
- * but with NULL next pointers. If they do, they can help us
- * link the dummy nodes into the list and retry.
- */
- cmm_smp_wmb(); /* populate data before RCU size */
- CMM_STORE_SHARED(ht->t.size, !i ? 1 : (1UL << i));
-
/*
* Link all dummy nodes into the table. Concurrent
* add/remove are helping us.
*/
init_table_link(ht, i, len);
+ /*
+ * Update table size.
+ */
+ cmm_smp_wmb(); /* populate data before RCU size */
+ CMM_STORE_SHARED(ht->t.size, !i ? 1 : (1UL << i));
+
dbg_printf("init new size: %lu\n", !i ? 1 : (1UL << i));
if (CMM_LOAD_SHARED(ht->in_progress_destroy))
break;
hash = ht->hash_fct(key, key_len, ht->hash_seed);
reverse_hash = bit_reverse_ulong(hash);
-restart:
size = rcu_dereference(ht->t.size);
index = hash & (size - 1);
order = get_count_order_ulong(index + 1);
dummy_node = (struct cds_lfht_node *) lookup;
/* We can always skip the dummy node initially */
node = rcu_dereference(dummy_node->p.next);
- if (unlikely(node == NULL)) {
- /*
- * We are executing concurrently with a hash table
- * expand, so we see a dummy node with NULL next value.
- * Help expand by linking this node into the list and
- * retry.
- */
- (void) _cds_lfht_add(ht, size >> 1, dummy_node, 0, 1);
- goto restart; /* retry */
- }
node = clear_flag(node);
for (;;) {
if (unlikely(is_end(node))) {
projects / urcu.git / commitdiff
