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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: confusion about message passing between the tasks
Date: Sat, 25 Oct 2014 15:11:20 +0100
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Date: 2014-10-25T15:11:20+01:00
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compguy45@gmail.com writes:

> Why are you passing task as parametar?

I assume you mean

   task type T (Next : T_Access) is

? (it would help if you quoted _some_ context)

I can see why you might think of that as a parameter, but in Ada the
word is "discriminant".

Next *either* designates (contains a pointer to) the "next" task in the
              chain of tasks, the one whose entry _this_ task is
              supposed to call when it's done,

     *or*     is null, in which case _this_ task is the last in the chain;

as implemented in

      if Next /= null then
         Put_Line ("kicking off next task");
         Next.Start (Data + 1);
      else
         Put_Line ("no next task");
      end if;

The task has to have some way of knowing which, if any, task it's
supposed to let know that it's finished.