1--
2-- Copyright(C) 1998
3-- All Rights Reserved. Salih Yurttas, ZCubes, BitsOfCode Software Systems, Inc..
4--
5-- Permission to use, copy, modify, and distribute this
6-- software and its documentation for EDUCATIONAL purposes
7-- and without fee is hereby granted provided that this
8-- copyright notice appears in all copies.
9--
10
11-- date : January 1, 1998.
12-- author : Salih Yurttas.
13
14-- trains_10.adb
15
16
17with Ada.Text_IO;
18use Ada.Text_IO;
19
20procedure Trains_10 is
21
22 type Train_Id is new Integer range 0..7;
23
24 package Train_IO is new Integer_IO(Train_Id);
25 use Train_IO;
26
27 T : Train_Id := 0;
28
29 task Points is
30 entry Cross(T : in Train_Id);
31 end Points;
32
33 task type Train;
34
35 TA : array(1..3) of Train;
36
37 procedure Approach_Points(T : in Train_Id) is
38 begin
39 Put("...Approach_Points");
40 Put(T);
41 New_Line;
42 end Approach_Points;
43
44 procedure Cross_Points(T : in Train_Id) is
45 begin
46 Put(T);
47 Put_Line(" Crossing_Points");
48 end Cross_Points;
49
50 procedure Go_Away_From_Points(T : in Train_Id) is
51 begin
52 Put(" Go_Away_From_Points...");
53 Put(T);
54 New_Line;
55 end Go_Away_From_Points;
56
57 task body Points is
58 begin
59 loop
60 select
61 accept Cross(T : in Train_Id) do
62 Cross_Points(T);
63 end Cross;
64 or terminate;
65 end select;
66 end loop;
67 end Points;
68
69 task body Train is
70 begin
71 T := T+1;
72 Approach_Points(T);
73 Points.Cross(T);
74 Go_Away_From_Points(T);
75 end Train;
76
77begin
78
79 null;
80
81end Trains_10;