-extern void timer_delay(time_t time);
-extern void timer_udelay(utime_t utime);
-INLINE time_t timer_tick(void);
-INLINE time_t timer_tick_unlocked(void);
-INLINE void timer_set_event_softint(Timer* timer, Hook func, void* user_data);
-INLINE void timer_set_delay(Timer* timer, time_t delay);