From: "John B. Matthews" <nospam@nospam.invalid>
Subject: Re: Barrier re-evaluation issue with GNAT 4.3.2
Date: Wed, 30 Sep 2009 11:59:09 -0400
Date: 2009-09-30T11:59:09-04:00 [thread overview]
Message-ID: <nospam-12AAE0.11590930092009@news.aioe.org> (raw)
In-Reply-To: h9vp0g$1kn$1@news.eternal-september.org
In article <h9vp0g$1kn$1@news.eternal-september.org>,
Reto Buerki <reet@codelabs.ch> wrote:
> John B. Matthews wrote:
> > Using Pragma Detect_Blocking, as suggested by Bob Duff, will tell
> > you if the compiler's warning is actualized at run-time. As this is
> > a work-around and your original code seems correct, you might
> > arrange things so that the original can be restored easily upon
> > upgrade or port.
>
> The code runs correctly even though Program_Error is raised when
> compiled with the Detect_Blocking pragma.
>
> I think it's good enough as a workaround, we will upgrade to GNAT
> 4.4.x as soon as possible.
Excellent, although upgrading has it's own perils. :-)
Another alternative, suggested by Dmitry A. Kazakov, is to replace entry
Wait with procedure Wait, which obviates the need for Signal:
with Ada.Text_IO;
with Alarm_Clock;
procedure Main is
My_Alarm : Alarm_Clock.Alarm_Type;
begin
Ada.Text_IO.Put_Line ("Setting alarm ...");
My_Alarm.Set;
Ada.Text_IO.Put_Line ("Waiting for alarm ...");
My_Alarm.Wait;
Ada.Text_IO.Put_Line ("ALARM!!");
end Main;
with Ada.Real_Time.Timing_Events;
package Alarm_Clock is
protected type Alarm_Type is
procedure Set;
procedure Wait;
end Alarm_Type;
end Alarm_Clock;
package body Alarm_Clock is
use Ada.Real_Time;
Timer : Timing_Events.Timing_Event;
Fired : Boolean := False;
protected body Alarm_Type is
procedure Wakeup(Event : in out Timing_Events.Timing_Event) is
begin
Fired := True;
end Wakeup;
procedure Set is
begin
Timer.Set_Handler(In_Time => Seconds (2),
Handler => Wakeup'Access);
end Set;
procedure Wait is
begin
loop
exit when Fired;
end loop;
end Wait;
end Alarm_Type;
end Alarm_Clock;
> Thanks for all your help!
I enjoyed the opportunity to examine this interesting question.
--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>
next prev parent reply other threads:[~2009-09-30 15:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-24 17:02 Barrier re-evaluation issue with GNAT 4.3.2 Reto Buerki
2009-09-24 17:47 ` Dmitry A. Kazakov
2009-09-25 8:50 ` Brad Moore
2009-09-25 9:17 ` Dmitry A. Kazakov
2009-09-25 9:57 ` Ludovic Brenta
2009-09-25 10:31 ` Dmitry A. Kazakov
2009-09-25 11:23 ` Jean-Pierre Rosen
2009-09-28 10:41 ` Reto Buerki
2009-09-25 17:06 ` Brad Moore
2009-09-25 18:42 ` Dmitry A. Kazakov
2009-09-25 19:39 ` Brad Moore
2009-09-28 10:18 ` Reto Buerki
2009-09-25 15:56 ` John B. Matthews
2009-09-26 14:23 ` John B. Matthews
2009-09-28 10:28 ` Reto Buerki
2009-09-28 12:39 ` John B. Matthews
2009-09-28 13:25 ` Reto Buerki
2009-09-28 14:05 ` Reto Buerki
2009-09-28 18:38 ` Jeffrey R. Carter
2009-09-28 18:51 ` Dmitry A. Kazakov
2009-09-29 8:37 ` Reto Buerki
2009-09-28 21:13 ` Robert A Duff
2009-09-28 22:28 ` Jeffrey R. Carter
2009-10-10 5:41 ` Randy Brukardt
2009-09-29 8:30 ` Reto Buerki
2009-09-29 15:06 ` John B. Matthews
2009-09-30 14:12 ` Reto Buerki
2009-09-30 15:59 ` John B. Matthews [this message]
2009-10-01 16:12 ` John B. Matthews
2009-10-01 17:17 ` Anh Vo
2009-10-02 2:26 ` John B. Matthews
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