+extern void signal_add(event_loop_t *loop, signal_t *sig, signal_cb_t cb, void *data, uint8_t signum);
+extern void signal_trigger(event_loop_t *loop, signal_t *sig);
+extern void signal_del(event_loop_t *loop, signal_t *sig);
+
+extern void idle_set(event_loop_t *loop, idle_cb_t cb, void *data);
+