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From: Martin Krischik <krischik@users.sourceforge.net>
Newsgroups: comp.lang.ada
Subject: Re: Finding out minimal allocation unit
Date: Tue, 03 Apr 2007 15:34:33 +0200
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Date: 2007-04-03T15:34:33+02:00
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Georg Bauhaus schrieb:
> On Tue, 2007-04-03 at 14:43 +0200, Stefan Bellon wrote:
> 
>> Is there a reliable way of finding out the smallest allocation unit?
> 
> FWIW,
> 
>  type LP is -- new ... with
>             record
>                 forward: access LP;
>                 backward: access LP;
>             end record;
>         for LP'Size use 63;
> 
> should make the compiler complain when 63 bits aren't enough.
> 

I think you misunderstood the OP: if you use new to create an object 
inside an storage pool then additional housekeeping informations are 
added to object.

Also if the storage pool uses C malloc (as GNAT does) then the object 
need to universally aligned. C - unlike Ada - demands that the pointer 
returned need to suitable for all kind of data.

So I believe the OP wanted to know how to find out how much memory for 
"new"ed object is allocated in total in order to know if extra 
optimisation is needed.

Martin