diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 847a9c6..dc23717 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -555,6 +555,9 @@
                     size_t          size() const {
                         return mActiveTracks.size();
                     }
+                    bool            isEmpty() const {
+                        return mActiveTracks.isEmpty();
+                    }
                     ssize_t         indexOf(const sp<T>& item) {
                         return mActiveTracks.indexOf(item);
                     }