ARM Club 3/TheARMClub_PDCD3.iso/hensa/programming/ada_1/Examples_demos_ada_diners1

Text File | 1992-10-01 | 7.4 KB | 326 lines

--::::::::::
--io_libs.ada
--::::::::::
-- Precompiled instantiations of Integer_IO and
-- Float_IO for the predefined Integer and Float types

WITH Text_IO;
PACKAGE My_Int_IO IS
  NEW Text_IO.Integer_IO (Num => Integer);

WITH Text_IO;
PACKAGE My_Flt_IO IS
  NEW Text_IO.Float_IO   (Num => Float);
--::::::::::
--random.ads
--::::::::::
PACKAGE Random IS

-- Simple pseudo-random number generator package.
-- Adapated from the Ada literature by
-- Michael B. Feldman, The George Washington University, November 1990.

  PROCEDURE Set_Seed (N : Positive);

  FUNCTION  Unit_Random RETURN Float;

    --returns a float >=0.0 and <1.0

  FUNCTION  Random_Int (N : Positive) RETURN Positive;

    --return a random integer in the range 1..N

END Random;
--::::::::::
--chop.ads
--::::::::::
PACKAGE Chop IS

  TASK TYPE Stick IS
    ENTRY Pick_Up;
    ENTRY Put_Down;
  END Stick;

END Chop;
--::::::::::
--phil.ads
--::::::::::
PACKAGE Phil IS

  TASK TYPE Philosopher IS

    ENTRY Come_To_Life (My_ID :      Positive;
                        Chopstick1 : Positive;
                        Chopstick2 : Positive);

  END Philosopher;

  TYPE States IS (Breathing, Thinking, Eating, Done_Eating,
                    Got_One_Stick, Got_Other_Stick);

END Phil;
--::::::::::
--room.ads
--::::::::::
WITH Chop;
WITH Phil;
PACKAGE Room IS

  Table_Size: CONSTANT := 5;
  SUBTYPE Table_Type IS Positive RANGE 1..Table_Size;

  Sticks:     ARRAY(Table_Type) OF Chop.Stick;

  TASK Head_Waiter IS
    ENTRY Open_The_Room;
    ENTRY Report_State(Which_Phil: Table_Type;
                       State: Phil.States;
                       How_Long: Natural := 0);
  END Head_Waiter;

END Room;
--::::::::::
--diners.ada
--::::::::::
WITH Room;
PROCEDURE Diners IS

BEGIN
  Room.Head_Waiter.Open_The_Room;
  LOOP
    DELAY 20.0;
  END LOOP;
END Diners;
--::::::::::
--random.adb
--::::::::::
WITH Calendar;
USE  Calendar;

PACKAGE BODY Random IS

-- Body of random number generator package.
-- Adapted from the Ada literature by
-- Michael B. Feldman, The George Washington University, November 1990.

  Modulus      : CONSTANT := 9317;

  TYPE Int_16 IS RANGE - 2 ** 15 .. 2 ** 15 - 1;

  TYPE Int_32 IS RANGE - 2 ** 31 .. 2 ** 31 - 1;

  SUBTYPE Seed_Range IS Int_16 RANGE 0 .. (Modulus - 1);

  Seed,
  Default_Seed : Seed_Range;

  PROCEDURE Set_Seed (N : Positive) IS SEPARATE;

  FUNCTION  Unit_Random RETURN Float IS SEPARATE;

  FUNCTION  Random_Int (N : Positive) RETURN Positive IS SEPARATE;
BEGIN
  Default_Seed := Int_16 (Int_32 (Seconds (Clock)) MOD Modulus);
  Seed := Default_Seed;
END Random;

SEPARATE (Random)

PROCEDURE Set_Seed (N : Positive) IS
BEGIN
  Seed := Seed_Range (N);
END Set_Seed;

SEPARATE (Random)

FUNCTION  Unit_Random RETURN Float IS
  Multiplier : CONSTANT := 421;
  Increment  : CONSTANT := 2073;
  Result     : Float;
BEGIN
  Seed := (Multiplier * Seed + Increment) MOD Modulus;
  Result := Float (Seed) / Float (Modulus);
  RETURN Result;
EXCEPTION
  WHEN Constraint_Error | Numeric_Error =>
    Seed := Int_16 ((Multiplier * Int_32 (Seed) + Increment) MOD Modulus);
    Result := Float (Seed) / Float (Modulus);
    RETURN Result;

END Unit_Random;

SEPARATE (Random)

FUNCTION  Random_Int (N : Positive) RETURN Positive IS
  Result : Integer RANGE 1 .. N;
BEGIN
  Result := Integer (Float (N) * Unit_Random + 0.5);
  RETURN Result;
EXCEPTION
  WHEN Constraint_Error | Numeric_Error =>
    RETURN 1;

END Random_Int;
--::::::::::
--chop.adb
--::::::::::
PACKAGE BODY Chop IS

  TASK BODY Stick IS

  BEGIN

    LOOP
      SELECT
        ACCEPT Pick_Up;
        ACCEPT Put_Down;
      OR
        TERMINATE;
      END SELECT;
    END LOOP;

  END Stick;

END Chop;
--::::::::::
--phil.adb
--::::::::::
WITH Room;
WITH Random;
PACKAGE BODY Phil IS

  TASK BODY Philosopher IS

    Who_Am_I   : Positive;
    First_Grab : Positive;
    Second_Grab: Positive;
    Meal_Time  : Natural;
    Think_Time : Natural;

  BEGIN
    ACCEPT Come_To_Life (My_ID :     Positive;
                        Chopstick1 : Positive;
                        Chopstick2 : Positive) DO
      Who_Am_I    := My_ID;
      First_Grab  := Chopstick1;
      Second_Grab := Chopstick2;

    END Come_To_Life;

    Room.Head_Waiter.Report_State(Who_Am_I, Breathing);

    LOOP

      Room.Sticks(First_Grab).Pick_Up;
      Room.Head_Waiter.Report_State(Who_Am_I, Got_One_Stick, First_Grab);

      Room.Sticks(Second_Grab).Pick_Up;
      Room.Head_Waiter.Report_State(Who_Am_I, Got_Other_Stick, Second_Grab);

      Meal_Time := Random.Random_Int(10);
      Room.Head_Waiter.Report_State(Who_Am_I, Eating, Meal_Time);

      DELAY Duration(Meal_Time);
      Room.Head_Waiter.Report_State(Who_Am_I, Done_Eating);

      Room.Sticks(First_Grab).Put_Down;
      Room.Sticks(Second_Grab).Put_Down;

      Think_Time := Random.Random_Int(10);
      Room.Head_Waiter.Report_State(Who_Am_I, Thinking, Think_Time);
      DELAY Duration(Think_Time);

    END LOOP;

  END Philosopher;

END Phil;
--::::::::::
--roomline.adb
--::::::::::
WITH Text_IO;
WITH Chop;
WITH Phil;
WITH Calendar;
PRAGMA Elaborate(Phil);
PACKAGE BODY Room IS

-- A line-oriented version of the Room package, for line-oriented
-- terminals like IBM 3270's where the user cannot do ASCII screen control.
-- This is the only file in the dining philosophers system that needs
-- changing to use in a line-oriented environment.
-- Michael B. Feldman, The George Washington University, November 1990.


  Phils:      ARRAY(Table_Type) OF Phil.Philosopher;

  TYPE Phil_Names IS (Dijkstra, Texel, Booch, Ichbiah, Stroustrup);

  TASK BODY Head_Waiter IS

    T : Integer;
    Start_Time: Calendar.Time;
    Phil_Names: CONSTANT ARRAY(1..5) OF String(1..18) :=
     ("Eddy Dijkstra     ",
      "Putnam Texel      ",
      "Grady Booch       ",
      "Jean Ichbiah      ",
      "Bjarne Stroustrup ");
    Blanks : CONSTANT String := "     ";

  BEGIN

    ACCEPT Open_The_Room;
    Start_Time := Calendar.Clock;

    Phils(1).Come_To_Life(1,1,2);
    Phils(3).Come_To_Life(3,3,4);
    Phils(2).Come_To_Life(2,2,3);
    Phils(5).Come_To_Life(5,1,5);
    Phils(4).Come_To_Life(4,4,5);

    LOOP
      SELECT
        ACCEPT Report_State(Which_Phil: Table_Type;
                         State: Phil.States;
                         How_Long: Natural := 0) DO
          T := Integer(Calendar."-"(Calendar.Clock,Start_Time));
          Text_IO.Put( "T=" & Integer'Image(T) & " "
            & Blanks(1..Which_Phil) & Phil_Names(Which_Phil));

          CASE State IS

            WHEN Phil.Breathing =>
              Text_IO.Put("Breathing");
            WHEN Phil.Thinking =>
              Text_IO.Put( "Thinking"
                         & Integer'Image(How_Long)
                         & " seconds.");
            WHEN Phil.Eating =>
              Text_IO.Put( "Eating"
                         & Integer'Image(How_Long)
                         & " seconds.");
            WHEN Phil.Done_Eating =>
              Text_IO.Put("Yum-yum (burp)");
            WHEN Phil.Got_One_Stick =>
              Text_IO.Put( "First chopstick"
                          & Integer'Image(How_Long));
            WHEN Phil.Got_Other_Stick =>
              Text_IO.Put( "Second chopstick"
                          & Integer'Image(How_Long));

          END CASE;
          Text_IO.New_Line;

         END Report_State;
        OR
          TERMINATE;
        END SELECT;

      END LOOP;

    END Head_Waiter;

END Room;