wfstack: document first/next return values

[urcu.git] / urcu / wfstack.h

diff --git a/urcu/wfstack.h b/urcu/wfstack.h
index b6992e888cfa71f2334c485034c11f7a788b9fac..20d1882c867b979910ad6000b8c3b64a8879a0c7 100644 (file)
--- a/urcu/wfstack.h
+++ b/urcu/wfstack.h
@@ -6,7 +6,7 @@
  *
  * Userspace RCU library - Stack with wait-free push, blocking traversal.
  *
- * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -162,6 +162,8 @@ extern struct cds_wfs_head *cds_wfs_pop_all_blocking(struct cds_wfs_stack *s);
  * Used by for-like iteration macros in urcu/wfstack.h:
  * cds_wfs_for_each_blocking()
  * cds_wfs_for_each_blocking_safe()
+ *
+ * Returns NULL if popped stack is empty, top stack node otherwise.
  */
 extern struct cds_wfs_node *cds_wfs_first_blocking(struct cds_wfs_head *head);
 
@@ -174,6 +176,9 @@ extern struct cds_wfs_node *cds_wfs_first_blocking(struct cds_wfs_head *head);
  * Used by for-like iteration macros in urcu/wfstack.h:
  * cds_wfs_for_each_blocking()
  * cds_wfs_for_each_blocking_safe()
+ *
+ * Returns NULL if reached end of popped stack, non-NULL next stack
+ * node otherwise.
  */
 extern struct cds_wfs_node *cds_wfs_next_blocking(struct cds_wfs_node *node);