ccan/list: Add list_empty_nocheck

[ccan] / ccan / list / list.h

diff --git a/ccan/list/list.h b/ccan/list/list.h
index 275442d23da05cb8fe9c462e75ffd589fa97e374..a4c21f189739a2b498b7487c70e454e4024c131e 100644 (file)
--- a/ccan/list/list.h
+++ b/ccan/list/list.h
@@ -95,8 +95,8 @@ struct list_node *list_check_node(const struct list_node *n,
 #define list_debug(h, loc) list_check((h), loc)
 #define list_debug_node(n, loc) list_check_node((n), loc)
 #else
-#define list_debug(h, loc) (h)
-#define list_debug_node(n, loc) (n)
+#define list_debug(h, loc) ((void)loc, h)
+#define list_debug_node(n, loc) ((void)loc, n)
 #endif
 
 /**
@@ -111,7 +111,7 @@ struct list_node *list_check_node(const struct list_node *n,
  * Example:
  *     static struct list_head my_list = LIST_HEAD_INIT(my_list);
  */
-#define LIST_HEAD_INIT(name) { { &name.n, &name.n } }
+#define LIST_HEAD_INIT(name) { { &(name).n, &(name).n } }
 
 /**
  * LIST_HEAD - define and initialize an empty list_head
@@ -291,6 +291,21 @@ static inline bool list_empty_nodebug(const struct list_head *h)
 }
 #endif
 
+/**
+ * list_empty_nocheck - is a list empty?
+ * @h: the list_head
+ *
+ * If the list is empty, returns true. This doesn't perform any
+ * debug check for list consistency, so it can be called without
+ * locks, racing with the list being modified. This is ok for
+ * checks where an incorrect result is not an issue (optimized
+ * bail out path for example).
+ */
+static inline bool list_empty_nocheck(const struct list_head *h)
+{
+       return h->n.next == &h->n;
+}
+
 /**
  * list_del - delete an entry from an (unknown) linked list.
  * @n: the list_node to delete from the list.