rculfhash: add assertion in path compression

[urcu.git] / rculfhash.c

diff --git a/rculfhash.c b/rculfhash.c
index 4b781f7b9012273b24dfb93e99afa0d664032daf..2565099d2c12b633dce919e927363b10ff63912c 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -672,6 +672,13 @@ void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node
                /* We can always skip the dummy node initially */
                iter = rcu_dereference(iter_prev->p.next);
                assert(iter_prev->p.reverse_hash <= node->p.reverse_hash);
+               /*
+                * We should never be called with dummy (start of chain)
+                * and logically removed node (end of path compression
+                * marker) being the actual same node. This would be a
+                * bug in the algorithm implementation.
+                */
+               assert(dummy != node);
                for (;;) {
                        if (unlikely(!clear_flag(iter)))
                                return;
@@ -890,8 +897,12 @@ void fini_table(struct cds_lfht *ht, struct rcu_table *t,
 
                len = !i ? 1 : 1UL << (i - 1);
                dbg_printf("fini order %lu len: %lu\n", i, len);
-               /* Update table size */
-               t->size = 1UL << (i - 1);
+               /*
+                * Update table size. Need to shrink this table prior to
+                * removal so gc lookups use non-logically-removed dummy
+                * nodes.
+                */
+               t->size = (i == 1) ? 0 : 1UL << (i - 2);
                /* Unlink */
                for (j = 0; j < len; j++) {
                        struct cds_lfht_node *fini_node =