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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Exception Propagation
Date: 1999/06/09
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Date: 1999-06-09T00:00:00+00:00
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In article <m3wvxef8zw.fsf@mheaney.ni.net>,
  Matthew Heaney <matthew_heaney@acm.org> wrote:
> Robert Dewar <robert_dewar@my-deja.com> writes:
>
> > I would have preferred that an unhandled exception in a task
> > caused termination of the entire program, you can always get
> > the bizarre effect in the RM if you really want it by doing:
> >
> >       exception when others => null;
> >
> > at the outer level of a task
>
> I don't understand this comment.
>
> Given this task body:
>
>   task body T is
>     ...
>   begin
>     ...
>   exception
>     when others => null;
>
>   end T;
>
> Are you saying that if an exception occurs, that that
> exception handler
> will cause behavior other than silent termination of task T?


No -- I am saying that I would have preferred semantics where
if an exception is unhandled in a task, the entire program is
terminated (as for an unhandled exception in the environment
task). Then if you want the current RM semantics of tasks
going away silently, you program it explicitly as shown above,
though once you are forced to program this explicitly, you
may well get the feeling that "null" is NOT the best choice
of code to write here :-)


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