Re: gnat: Execution_Time is not supported in this configuration

["John B. Matthews" <nospam@nospam.invalid>]

In article 
<5e5d6fb5-e719-4195-925c-d1286699393d@f16g2000yqm.googlegroups.com>,
 singo <sander.ingo@gmail.com> wrote:

> I have recently become very interested of Ada 2005, and it's 
> real-time annex. However, as a new user of Ada I face some problems 
> with the software.
> 
> I cannot get the package Ada.Execution_Time to work with gnat, 
> although the gnat documentation says that the real-time annex is 
> fully supported... I use the gnat version 4.4 on a Ubuntu 9.10 
> distribution.
> 
> The typical error message I get is
> 
> gcc -c executiontime.adb
> Execution_Time is not supported in this configuration
> compilation abandoned

Georg Bauhaus has helpfully referred you to comments in 
Ada.Execution_Time.

> How can I configure gnat to support the Ada.Execution_Time package?

I defer to Dmitry A. Kazakov about Windows, but this variation produces 
similar results on MacOS 10.5 & Ubuntu 9.10 using GNAT 4.3.4:

<code>
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Real_Time; use Ada.Real_Time;

procedure ExecutionTime is
   task T;

   task body T is
      Start : Time := Clock;
      Interval : Time_Span := Milliseconds(100);
   begin
      loop
         Put_Line(Duration'Image(To_Duration(Clock - Start)));
         delay To_Duration(Interval);
      end loop;
   end T;
begin
   null;
end ExecutionTime;
</code>

<console>
$ ./executiontime 
 0.000008000
 0.100168000
 0.200289000
 0.300409000
 0.400527000
 0.500575000
...
</console>

-- 
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>