diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index f7ad6b1..a2e2511 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -60,6 +60,7 @@
             int16_t     *mainBuffer() const { return mMainBuffer; }
             int         auxEffectId() const { return mAuxEffectId; }
     virtual status_t    getTimestamp(AudioTimestamp& timestamp);
+            void        signal();
 
 // implement FastMixerState::VolumeProvider interface
     virtual uint32_t    getVolumeLR();