Re: Need info about Ada tasks

[Fionn Mac Cumhaill <invisible@hiding.from.spam>]

On Thu, 25 Sep 2008 15:49:28 +0200, "Dmitry A. Kazakov"
<mailbox@dmitry-kazakov.de> wrote:

>On Thu, 25 Sep 2008 13:31:27 GMT, Fionn Mac Cumhaill wrote:
>
>> My simple solution has a minor problem; I have a select just after the
>> display routine that receives the abort message, but if the message
>> doesn't arrive on time I get another iteration of the loop before the
>> task aborts. How can I make this thing abort immediately, even when I
>> have a delay(60.0) to give a 1-minute delay between display refreshes?
>> I.e., how do I bail out in the middle of a delay?
>
>1. If the abort event is implemented as a protected object:
>
>task body Refresh_Engine is
>begin
>   loop
>      ... -- Refresh the display
>      select -- Timed entry call
>         Abort_Event.Wait;
>         exit;
>      or delay 60.0;
>      end select;
>   end loop;
>end Refresh_Engine;
>
>2. If the abort event is signaled by an entry call:
>
>task body Refresh_Engine is
>begin
>   loop
>      ... -- Refresh the display
>      select -- Selective accept with a time out alternative
>         accept Abort_Event;
>         exit;
>      or delay 60.0;
>      end select;
>   end loop;
>end Refresh_Engine;

Many thanks - that was exactly what I needed to know.