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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Problem with task component
Date: Wed, 19 Sep 2012 20:48:03 +0200
Organization: cbb software GmbH
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Date: 2012-09-19T20:48:03+02:00
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On Wed, 19 Sep 2012 19:22:07 +0100, Simon Wright wrote:

> If a Limited_Controlled type has a component of a task type, is it wrong
> to call an entry of the task from Initialize?

Right, this is mandated by 7.6(12), because the alternative is much worse,
in presence of class-wide access discriminant to the container, which most
people want.

The simple rule is that you should never ever have task components which
you need to communicate to upon initialization and/or finalization.

Always use pointers to tasks. But doing so, you should be extremely careful
preventing dispatch in the task body during these actions. Which is the
rationale for 7.6(12).

P.S. I am afraid that all my rants about construction/destruction issues in
Ada were in vain.

P.P.S. The issue with task components falls into the category "class-wide
constructor." Class initialization/finalization is the earliest/latest time
when it is type-safe to communicate with a task that dispatches in its
body.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de