question: public long extractAlarm ( long now , boolean isTest ) { long lastTime = _now . getAndSet ( now ) ; long nextTime = _nextAlarmTime . get ( ) ; if ( now < nextTime ) { return nextTime ; } _nextAlarmTime . set ( now + CLOCK_NEXT ) ; int delta ; delta = ( int ) ( now - lastTime ) / CLOCK_INTERVAL ; delta = Math . min ( delta , CLOCK_PERIOD ) ; Alarm alarm ; int bucket = getBucket ( lastTime ) ; for ( int i = 0 ; i <= delta ; i ++ ) { while ( ( alarm = extractNextAlarm ( bucket , now , isTest ) ) != null ) { dispatch ( alarm , now , isTest ) ; } bucket = ( bucket + 1 ) % CLOCK_PERIOD ; } while ( ( alarm = extractNextCurrentAlarm ( ) ) != null ) { dispatch ( alarm , now , isTest ) ; } long next = updateNextAlarmTime ( now ) ; _lastTime = now ; return next ; }
target:  Returns the next alarm ready to run