diff --git a/trunk/src/app/srs_app_source.hpp b/trunk/src/app/srs_app_source.hpp
index 7c626b7eb..fe82f6332 100755
--- a/trunk/src/app/srs_app_source.hpp
+++ b/trunk/src/app/srs_app_source.hpp
@@ -190,6 +190,10 @@ private:
     * if no iframe found, clear it.
     */
     virtual void shrink();
+public:
+    /**
+     * clear all messages in queue.
+     */
     virtual void clear();
 };