1 files changed, 10 insertions, 0 deletions
diff --git a/cpp/src/qpid/sys/OutputTask.h b/cpp/src/qpid/sys/OutputTask.h
index 109765b8c3..005ae7dbc4 100644
--- a/cpp/src/qpid/sys/OutputTask.h
+++ b/cpp/src/qpid/sys/OutputTask.h
@@ -28,7 +28,17 @@ namespace sys {
     {
     public:
         virtual ~OutputTask() {}
+        /** Generate some  output.
+         *@return true if output was generated, false if there is no work to do.
+         */
         virtual bool doOutput() = 0;
+
+        /** Check if there may be work to do, but don't do it.
+         * @return True if there may be work to do, false if there is none.
+         * Can to return a false positive, to allow implementations to do a
+         * faster check than doOutput(). Must never return a false negative.
+         */
+        virtual bool hasOutput() = 0;
     };
 
 }