+ static size_t _working_buffers_size;
+
+ /* these collections of working buffers for supporting
+ playlist's reading from potentially nested/recursive
+ sources assume SINGLE THREADED reads by the butler
+ thread, or a lock around calls that use them.
+ */
+
+ static std::vector<boost::shared_ptr<Sample> > _mixdown_buffers;
+ static std::vector<boost::shared_ptr<gain_t> > _gain_buffers;
+ static Glib::StaticMutex _level_buffer_lock;
+
+ static void ensure_buffers_for_level (uint32_t, framecnt_t);
+ static void ensure_buffers_for_level_locked (uint32_t, framecnt_t);
+