-- Our solution to Outside Assignment 6:
with text_io, calendar; use text_io, calendar;
procedure tasking is
   interval        : constant duration := 5.0;
   total_intervals : constant positive := 9;
   start_time      : constant time := clock;
   quitting_time   : constant time := start_time +
                                             total_intervals*interval;
   next_time       : time := start_time;
   task type tick is
      ENTRY IDENTIFY(TASK_NUMBER : IN NATURAL);
      entry shutdown;
   end tick;
   T               : ARRAY(1 .. 3) OF TICK;
   PERIOD          : CONSTANT ARRAY(T'RANGE) OF POSITIVE := (2, 3, 4);
   TIMER           : ARRAY(T'RANGE) OF NATURAL := (OTHERS => 0);
   task body tick is
      quit : boolean := false;
   begin
      while not quit loop
         select
            ACCEPT IDENTIFY(TASK_NUMBER : IN NATURAL) DO
               PUT_LINE("Task number" & INTEGER'IMAGE(TASK_NUMBER) &
                    " is starting.");
            END IDENTIFY;
         or
            accept shutdown;
            quit := true;
         end select;
      end loop;
   end tick;
begin
   while next_time < quitting_time loop
      FOR I IN T'RANGE LOOP
         IF TIMER(I) = 0 THEN
            T(I).IDENTIFY(I);
            TIMER(I) := PERIOD(I);
         END IF;
         TIMER(I) := TIMER(I) - 1;
      END LOOP;
      next_time := next_time + interval;
      delay next_time - clock; new_line;
   end loop;
   FOR I IN T'RANGE LOOP
      T(I).SHUTDOWN;
   END LOOP;
end tasking;