+void *
+tdm_display_find_hwc_stamp(tdm_private_display *private_display, double stamp);
+tdm_private_hwc *
+tdm_display_find_private_hwc(tdm_private_display *private_display, tdm_hwc *hwc_backend);
+
+tdm_error
+tdm_output_init(tdm_private_display *private_display);
+
+tdm_error
+tdm_output_call_thread_cb_destroy(tdm_private_output *private_output);