X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=rculfhash.c;h=5264a8ec7fc9747afeccbc544dad3d2b3a80a54a;hb=0adc36a89d4089a653c11a68ea6fb92a2ec7c5aa;hp=b9c184fcc5f22e0e3043dd7f8b2c8a3ad2f6756f;hpb=83beee94416bdffdec505bc33cfd79859f6aa243;p=urcu.git

diff --git a/rculfhash.c b/rculfhash.c
index b9c184f..5264a8e 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -119,12 +119,9 @@
  * 
  * order              bits       reverse
  * 0               0  000        000
- *                 |
- * 1               |  1  001        100       <-    <-
- *                 |  |                        |     |
- * 2               |  |  2  010        010     |     |
+ * 1               |  1  001        100             <-
+ * 2               |  |  2  010        010    <-     |
  *                 |  |  |  3  011        110  | <-  |
- *                 |  |  |  |                  |  |  |
  * 3               -> |  |  |  4  100        001  |  |
  *                    -> |  |     5  101        101  |
  *                       -> |        6  110        011
@@ -748,6 +745,7 @@ void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node
 		iter_prev = dummy;
 		/* We can always skip the dummy node initially */
 		iter = rcu_dereference(iter_prev->p.next);
+		assert(!is_removed(iter));
 		assert(iter_prev->p.reverse_hash <= node->p.reverse_hash);
 		/*
 		 * We should never be called with dummy (start of chain)
@@ -772,8 +770,6 @@ void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node
 			new_next = flag_dummy(clear_flag(next));
 		else
 			new_next = clear_flag(next);
-		if (is_removed(iter))
-			new_next = flag_removed(new_next);
 		(void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next);
 	}
 	return;
@@ -787,10 +783,9 @@ int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
 {
 	struct cds_lfht_node *dummy, *ret_next;
 	struct _cds_lfht_node *lookup;
-	int flagged = 0;
 
 	if (!old_node)	/* Return -ENOENT if asked to replace NULL node */
-		goto end;
+		return -ENOENT;
 
 	assert(!is_removed(old_node));
 	assert(!is_dummy(old_node));
@@ -804,7 +799,7 @@ int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
 			 * Too late, the old node has been removed under us
 			 * between lookup and replace. Fail.
 			 */
-			goto end;
+			return -ENOENT;
 		}
 		assert(!is_dummy(old_next));
 		assert(new_node != clear_flag(old_next));
@@ -822,13 +817,10 @@ int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
 		ret_next = uatomic_cmpxchg(&old_node->p.next,
 			      old_next, flag_removed(new_node));
 		if (ret_next == old_next)
-			break;
+			break;		/* We performed the replacement. */
 		old_next = ret_next;
 	}
 
-	/* We performed the replacement. */
-	flagged = 1;
-
 	/*
 	 * Ensure that the old node is not visible to readers anymore:
 	 * lookup for the node, and remove it (along with any other
@@ -837,17 +829,9 @@ int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
 	lookup = lookup_bucket(ht, size, bit_reverse_ulong(old_node->p.reverse_hash));
 	dummy = (struct cds_lfht_node *) lookup;
 	_cds_lfht_gc_bucket(dummy, new_node);
-end:
-	/*
-	 * Only the flagging action indicated that we (and no other)
-	 * replaced the node from the hash table.
-	 */
-	if (flagged) {
-		assert(is_removed(rcu_dereference(old_node->p.next)));
-		return 0;
-	} else {
-		return -ENOENT;
-	}
+
+	assert(is_removed(rcu_dereference(old_node->p.next)));
+	return 0;
 }
 
 /*
@@ -958,10 +942,9 @@ int _cds_lfht_del(struct cds_lfht *ht, unsigned long size,
 {
 	struct cds_lfht_node *dummy, *next, *old;
 	struct _cds_lfht_node *lookup;
-	int flagged = 0;
 
 	if (!node)	/* Return -ENOENT if asked to delete NULL node */
-		goto end;
+		return -ENOENT;
 
 	/* logically delete the node */
 	assert(!is_dummy(node));
@@ -972,7 +955,7 @@ int _cds_lfht_del(struct cds_lfht *ht, unsigned long size,
 
 		next = old;
 		if (unlikely(is_removed(next)))
-			goto end;
+			return -ENOENT;
 		if (dummy_removal)
 			assert(is_dummy(next));
 		else
@@ -980,9 +963,7 @@ int _cds_lfht_del(struct cds_lfht *ht, unsigned long size,
 		new_next = flag_removed(next);
 		old = uatomic_cmpxchg(&node->p.next, next, new_next);
 	} while (old != next);
-
 	/* We performed the (logical) deletion. */
-	flagged = 1;
 
 	/*
 	 * Ensure that the node is not visible to readers anymore: lookup for
@@ -992,17 +973,9 @@ int _cds_lfht_del(struct cds_lfht *ht, unsigned long size,
 	lookup = lookup_bucket(ht, size, bit_reverse_ulong(node->p.reverse_hash));
 	dummy = (struct cds_lfht_node *) lookup;
 	_cds_lfht_gc_bucket(dummy, node);
-end:
-	/*
-	 * Only the flagging action indicated that we (and no other)
-	 * removed the node from the hash.
-	 */
-	if (flagged) {
-		assert(is_removed(rcu_dereference(node->p.next)));
-		return 0;
-	} else {
-		return -ENOENT;
-	}
+
+	assert(is_removed(rcu_dereference(node->p.next)));
+	return 0;
 }
 
 static