Re: requeue with abort and timed call

[belteshazzar <gbelteshazzar@gmail.com>]

On Jan 4, 1:56 pm, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:
> On Sun, 4 Jan 2009 10:03:44 -0800 (PST), ishik...@arielworks.com wrote:
> > On Jan 4, 6:09 am, "Jeffrey R. Carter"
> > <spam.jrcarter....@spam.acm.org> wrote:
> >> Delay statements and calls to Ada.Text_IO.Put_Line are potentially blocking
> >> operations. It is an error to call potentially blocking operations from a
> >> protected action. See ARM 9.5.1.
> > I'm sorry, I overlooked it.
>
> No, it is perfectly legal to use Put_Line in protected actions *with* GNAT.
>
> GNAT implementation explicitly permits this use. So Jeffrey's comment was
> irrelevant here.
>
> You should report this bug to AdaCore.
>
> > How about this one;
>
> > with Ada.Text_IO; use Ada.Text_IO;
> > procedure Timed_Protected is
> >    Z : boolean := True;
>
> Pedantically, you should have added pragma Atomic (Z), because you access
> it from different tasks. And probably Volatile (Z) to prevent loop
> optimization.
>
> But much simpler would be a primitive busy waiting:
>
> entry E1 when True is
>    T : Time := Clock + 5.0;
> begin
>    for I in Unsigned_64'Range loop
>       exit when Clock >= T;
>    end loop;
> end E1;
>
> --
> Regards,
> Dmitry A. Kazakovhttp://www.dmitry-kazakov.de

it was my understanding that pragma atomic does nothing for tasks, it
just tells the compiler to ensure that the architecture implements
atomic memory access.

also if pragma atomic is used this implies volatile.