Re: select delay; then abort... in Annex E

["Alex R. Mosteo" <devnull@mailinator.com>]

Dr. Adrian Wrigley wrote:

> Hi guys,
> 
> Things are now working *much* better with my Annex E setup here.
> 
> The server hasn't been totally free of problems, but at least I
> can't point the finger at Glade this time ;-)
> 
> I wanted to limit the execution time of a partition. So I tried
> something like:
> 
> select
>    delay 10.0;
>    Complain;
> then abort
>    RemoteProcedure;
> end select;
> 
> the intent was that the partition would terminate if the
> RemoteProcedure exceeded the alloted 10s of execution time.
> 
> Unfortunately, what happens is that the code runs for the full
> duration of the RemoteProcedure (say 10 minutes), then it
> invokes Complain, finally exiting.

This is the behavior you get if you try the same with a Text_Io.Get_Line
call (that indeed is potentially blocking IO).

> Why can't the RemoteProcedure be aborted?  Is it because it
> is a blocking operation (E.4.17)? E.4.13 suggests the construct
> can be aborted (cancelling the remote operation), but the
> above code suggests it can't.
> 
> Is there a way to get my partition to terminate regardless
> of outstanding remote calls?

An idea is to do it the dirty way, creating a new task to do the call and
aborting it the rough way. I've taken a quick look at ARM05/9.8.5 but
couldn't conclude anything.