extern void signal_add(signal_t *sig, signal_cb_t cb, void *data, int signum);
extern void signal_del(signal_t *sig);
extern bool event_loop(void);
extern void signal_add(signal_t *sig, signal_cb_t cb, void *data, int signum);
extern void signal_del(signal_t *sig);
extern bool event_loop(void);