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From: "Hibou57 (Yannick Duchêne)" <yannick_duchene@yahoo.fr>
Subject: Re: Private or public task ?
Date: Wed, 10 Feb 2010 00:29:53 -0800 (PST)
Date: 2010-02-10T00:29:53-08:00	[thread overview]
Message-ID: <8bf887ec-38cc-4327-8cf6-38af4925e786@a5g2000yqi.googlegroups.com> (raw)
In-Reply-To: ca04a621-bdf9-4958-b395-6e59126e7511@x22g2000yqx.googlegroups.com

On 10 fév, 09:17, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> > There are two kinds of blockings: bounded and unbounded. The idea is
> > that when computing a time budget, you can account for bounded
> > blockings, but not unbounded ones.
> > The "potentially blocking" phrase should be understood as really meaning
> > unbounded.
>
> Well, I know what you try to convey, but there are traps:
>
>    delay Some_Static_Constant;
>
> Is it bounded or unbounded?
>
> As far as WCET (or any other time-based analysis) goes, the above can
> be accounted for statically. Still, it is a no-no within any protected
> operation.
Interesting enigma

I would say Bounded, as it is predictable.
... as long as the delay is short, otherwise it will break the other
rule stating that a protected operation should be fast to execute.

If I try to have a delay X.Y in a protected operation, GNAT just warns
me “ potentially blocking operation in protected operation ”, while
the program is still compiled.

You've said “ it is a no-no within any protected ” : do you get a
compilation error when you do the same ?

I've not seen anything in the Rationale nor in the ARM which
explicitly disallow it anyway (but as these are long pages I should
later read again, I may have miss it).



  reply	other threads:[~2010-02-10  8:29 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-05 20:54 Private or public task ? Hibou57 (Yannick Duchêne)
2010-02-05 20:56 ` Hibou57 (Yannick Duchêne)
2010-02-05 21:38 ` Jeffrey R. Carter
2010-02-05 21:53   ` Hibou57 (Yannick Duchêne)
2010-02-08  9:55     ` Alex R. Mosteo
2010-02-08 10:02     ` Jean-Pierre Rosen
2010-02-08 17:28     ` Maciej Sobczak
2010-02-09  8:43       ` Dmitry A. Kazakov
2010-02-09 12:07       ` Hibou57 (Yannick Duchêne)
2010-02-09 14:26         ` Jean-Pierre Rosen
2010-02-09 18:17           ` Hibou57 (Yannick Duchêne)
2010-02-10  8:17           ` Maciej Sobczak
2010-02-10  8:29             ` Hibou57 (Yannick Duchêne) [this message]
2010-02-10  8:40               ` Martin
2010-02-10 11:44                 ` Jean-Pierre Rosen
2010-02-10 12:51                   ` Martin
2010-02-10 16:17                 ` Robert A Duff
2010-02-10 11:38             ` Jean-Pierre Rosen
2010-02-13 11:09           ` Dmitry A. Kazakov
2010-02-09 15:20         ` Robert A Duff
2010-02-09 18:26           ` Hibou57 (Yannick Duchêne)
2010-02-09 14:44       ` Alex R. Mosteo
2010-02-09 23:38   ` mkasun
2010-02-09 23:51     ` Robert A Duff
2010-02-10  0:01     ` Jeffrey R. Carter
2010-02-05 21:40 ` Dmitry A. Kazakov
2010-02-05 22:09   ` Hibou57 (Yannick Duchêne)
2010-02-05 22:57     ` sjw
2010-02-06  2:20   ` Hibou57 (Yannick Duchêne)
2010-02-06  2:23     ` Hibou57 (Yannick Duchêne)
2010-02-06  3:29     ` Jeffrey R. Carter
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