int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src, int timeout);
int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout);
int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src, int timeout);
int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout);