wfcqueue: document first/next return values

[urcu.git] / urcu / wfcqueue.h

diff --git a/urcu/wfcqueue.h b/urcu/wfcqueue.h
index d9ec5349d7be203da7f80f6e6c0de5cda96e20e9..b6be9f3dfaad4ca5bea9db29ad72dd043d1ffada 100644 (file)
--- a/urcu/wfcqueue.h
+++ b/urcu/wfcqueue.h
@@ -280,6 +280,8 @@ extern enum cds_wfcq_ret __cds_wfcq_splice_nonblocking(
  * Used by for-like iteration macros:
  * __cds_wfcq_for_each_blocking()
  * __cds_wfcq_for_each_blocking_safe()
+ *
+ * Returns NULL if queue is empty, first node otherwise.
  */
 extern struct cds_wfcq_node *__cds_wfcq_first_blocking(
                struct cds_wfcq_head *head,
@@ -306,6 +308,9 @@ extern struct cds_wfcq_node *__cds_wfcq_first_nonblocking(
  * Used by for-like iteration macros:
  * __cds_wfcq_for_each_blocking()
  * __cds_wfcq_for_each_blocking_safe()
+ *
+ * Returns NULL if reached end of queue, non-NULL next queue node
+ * otherwise.
  */
 extern struct cds_wfcq_node *__cds_wfcq_next_blocking(
                struct cds_wfcq_head *head,