Re: tasks as part of record

[Simon Wright <simon@pushface.org>]

Stribor40 <ikamzic@gmail.com> writes:

> I though it would be easier if task is componenet of record.  What i
> would like is that every time task runs i would like to operate on
> components of student record.
> For example for each student there will be one tasks.  When each tasks
> run i want it to identify yourself to the screen with student number
> value. For example
>
> This is task #.       -- where # is student number

I'm not saying this is a good idea; limited types can be awkward, and
there will be all sorts of problems with the tasking if you ever want to
delete a student. But, for the record,

   with Ada.Text_IO; use Ada.Text_IO;
   procedure Strib is
      type Student;
      task type T (This : access Student) is
         entry Start (Number : Positive);
      end T;
      type Student is limited record     -- has to be limited
         Student_Number : Positive range 1 .. 10;
         Name : String (1 .. 10);
         Count : Integer;
         The_Task : T (Student'Access);  -- the current Student
      end record;
      task body T is
      begin
         accept Start (Number : Positive) do
            Put_Line ("starting task" & Positive'Image (Number));
            This.Student_Number := Number;
         end Start;
         delay 1.0;
         Put_Line ("this is task" & Positive'Image (This.Student_Number));
      end T;
      Students : array (1 .. 10) of Student;
   begin
      for J in Students'Range loop
         Students (J).The_Task.Start (Number => J);
      end loop;
   end Strib;