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From: Jacob Sparre Andersen <sparre@hugin.crs4.it>
Newsgroups: comp.lang.ada
Subject: Re: [newbie question] tasks and protected types
Date: 29 Apr 2005 13:23:10 +0200
Organization: hacking.dk - Doing fun stuff with open source
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Date: 2005-04-29T13:23:10+02:00
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Alex R. Mosteo wrote:
> Jacob Sparre Andersen wrote:

> >    protected body Printer is
> >       procedure Put_Line (Item : in     String) is
> >       begin
> >          Ada.Text_IO.Put_Line (Item => Item);
> >          Ada.Text_IO.Flush;
> >       end Put_Line;
> >    end Printer;
> 
> Isn't this considered a blocking operation?

I think I have heard something like that too, but I have not been able
to find it written down anywhere.

> I've read that it is not something to avoid in practice, but this
> advice can be specific for GNAT.

I only tested my version with GNAT, so I can't disprove that.

If calls to Ada.Text_IO _are_ potentially blocking operations, that
means that one has to move the calls to a task.  But from a logical
point of view, using a protected object seems like the right way to do
it.

Jacob
-- 
A password should be like a toothbrush. Use it every day;
change it regularly; and DON'T share it with friends.