ADA Programming Guide/ADA Programming Guide.iso/adasmall/eat-sem.ada

Text File | 1996-01-30 | 6KB | 235 lines

with  SMALL_SP;
use  SMALL_SP;
procedure EAT is

    SCREEN: SEMAPHORE := 1;

    task DIJKSTRA is
      entry GIVE_BIRTH;
    end DIJKSTRA;

    task LISKOV is
      entry GIVE_BIRTH;
    end LISKOV;

    task SAMMET is
      entry GIVE_BIRTH;
    end SAMMET;

    task GEHANI is
      entry GIVE_BIRTH;
    end GEHANI;

    task CHOPSTICK1 is
      entry PICKUP;
      entry PUTDOWN;
    end CHOPSTICK1;

    task CHOPSTICK2 is
      entry PICKUP;
      entry PUTDOWN;
    end CHOPSTICK2;

    task CHOPSTICK3 is
      entry PICKUP;
      entry PUTDOWN;
    end CHOPSTICK3;

    task CHOPSTICK4 is
      entry PICKUP;
      entry PUTDOWN;
    end CHOPSTICK4;

    NO_MEALS : integer := 3;

    task body DIJKSTRA is
       LENGTH_OF_MEAL: FLOAT;
    begin
        accept GIVE_BIRTH do
          WAIT(SCREEN);
          PUT("Eddy Dijkstra living and breathing");
          NEW_LINE;
          SIGNAL(SCREEN);
        end GIVE_BIRTH;
      for x in 1..NO_MEALS loop
        CHOPSTICK1.PICKUP;
        CHOPSTICK2.PICKUP;
        LENGTH_OF_MEAL := RANDOM(9) + 1;
        WAIT(SCREEN);
        PUT("Eddy Dijkstra eating meal"); PUT(x:2);
        PUT(" with chopsticks 1 and 2");
        PUT(" for"); PUT(LENGTH_OF_MEAL:2:0); PUT(" seconds");
        NEW_LINE;
        SIGNAL(SCREEN);
        delay LENGTH_OF_MEAL;
        WAIT(SCREEN);
        PUT("Eddy Dijkstra done");
        NEW_LINE;
        SIGNAL(SCREEN);
        CHOPSTICK1.PUTDOWN;
        CHOPSTICK2.PUTDOWN;
        delay 5.0;
      end loop;
      WAIT(SCREEN);
      PUT("Eddy Dijkstra burp");
      NEW_LINE;
      SIGNAL(SCREEN);
    end DIJKSTRA;

    task body LISKOV is
        LENGTH_OF_MEAL: FLOAT;
    begin
        accept GIVE_BIRTH do
          WAIT(SCREEN);
          PUT(" Barbie Liskov living and breathing");
          NEW_LINE;
          SIGNAL(SCREEN);
        end GIVE_BIRTH;
      for x in 1..NO_MEALS loop
        CHOPSTICK2.PICKUP;
        CHOPSTICK3.PICKUP;
        LENGTH_OF_MEAL := RANDOM(9) + 1;
        WAIT(SCREEN);
        PUT(" Barbie Liskov eating meal"); PUT(x:2);
        PUT(" with chopsticks 2 and 3");
        PUT(" for"); PUT(LENGTH_OF_MEAL:2:0); PUT(" seconds");
        NEW_LINE;
        SIGNAL(SCREEN);
        delay LENGTH_OF_MEAL;
        WAIT(SCREEN);
        PUT(" Barbie Liskov done");
        NEW_LINE;
        SIGNAL(SCREEN);
        CHOPSTICK2.PUTDOWN;
        CHOPSTICK3.PUTDOWN;
        delay 5.0;
      end loop;
      WAIT(SCREEN);
      PUT(" Barbie Liskov burp");
      NEW_LINE;
      SIGNAL(SCREEN);
    end LISKOV;

    task body SAMMET is
        LENGTH_OF_MEAL: FLOAT;
    begin
        accept GIVE_BIRTH do
          WAIT(SCREEN);
          PUT("  Jeannie Sammet living and breathing");
          NEW_LINE;
          SIGNAL(SCREEN);
        end GIVE_BIRTH;
      for x in 1..NO_MEALS loop
        CHOPSTICK3.PICKUP;
        CHOPSTICK4.PICKUP;
        LENGTH_OF_MEAL := RANDOM(9) + 1;
        WAIT(SCREEN);
        PUT("  Jeannie Sammet eating meal"); PUT(x:2);
        PUT(" with chopsticks 3 and 4");
        PUT(" for"); PUT(LENGTH_OF_MEAL:2:0); PUT(" seconds");
        NEW_LINE;
        SIGNAL(SCREEN);
        delay LENGTH_OF_MEAL;
        WAIT(SCREEN);
        PUT("  Jeannie Sammet done");
        NEW_LINE;
        SIGNAL(SCREEN);
        CHOPSTICK3.PUTDOWN;
        CHOPSTICK4.PUTDOWN;
        delay 5.0;
      end loop;
      WAIT(SCREEN);
      PUT("  Jeannie Sammet burp");
      NEW_LINE;
      SIGNAL(SCREEN);
    end SAMMET;

    task body GEHANI is
        LENGTH_OF_MEAL : FLOAT;
    begin
        accept GIVE_BIRTH do
          WAIT(SCREEN);
          PUT("   Narain Gehani living and breathing");
          NEW_LINE;
          SIGNAL(SCREEN);
        end GIVE_BIRTH;
      for x in 1..NO_MEALS loop
        CHOPSTICK1.PICKUP;
        CHOPSTICK4.PICKUP;
        LENGTH_OF_MEAL := RANDOM(9) + 1;
        WAIT(SCREEN);
        PUT("   Narain Gehani eating meal"); PUT(x:2);
        PUT(" with chopsticks 1 and 4");
        PUT(" for"); PUT(LENGTH_OF_MEAL:2:0); PUT(" seconds");
        NEW_LINE;
        SIGNAL(SCREEN);
        delay LENGTH_OF_MEAL;
        WAIT(SCREEN);
        PUT("   Narain Gehani done");
        NEW_LINE;
        SIGNAL(SCREEN);
        CHOPSTICK1.PUTDOWN;
        CHOPSTICK4.PUTDOWN;
        delay 5.0;
      end loop;
      WAIT(SCREEN);
      PUT("   Narain Gehani burp");
      NEW_LINE;
      SIGNAL(SCREEN);
    end GEHANI;

  task body CHOPSTICK1 is
    begin
      loop
        select
          accept PICKUP;
          accept PUTDOWN;
        or
          terminate;
        end select;
      end loop;
    end CHOPSTICK1;

  task body CHOPSTICK2 is
    begin
      loop
        select
          accept PICKUP;
          accept PUTDOWN;
        or
          terminate;
        end select;
      end loop;
    end CHOPSTICK2;

  task body CHOPSTICK3 is
    begin
      loop
        select
          accept PICKUP;
          accept PUTDOWN;
        or
          terminate;
        end select;
      end loop;
    end CHOPSTICK3;

  task body CHOPSTICK4 is
    begin
      loop
        select
          accept PICKUP;
          accept PUTDOWN;
        or
          terminate;
        end select;
      end loop;
    end CHOPSTICK4;

begin
  DIJKSTRA.GIVE_BIRTH;
  LISKOV.GIVE_BIRTH;
  SAMMET.GIVE_BIRTH;
  GEHANI.GIVE_BIRTH;
end EAT;