From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sun, 11 Sep 2011 01:32:45 +0000 (-0700)
Subject: rculfhash: add assertion in path compression
X-Git-Tag: v0.7.0~43^2~163
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=bd4db1530ed788ea97c8a9e4c0d04ef757181ad6;p=urcu.git

rculfhash: add assertion in path compression

Detects incorrect usage of path compression.

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

diff --git a/rculfhash.c b/rculfhash.c
index 003ab0b..2565099 100644
--- 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;