From: Dale Peakall (dale.peakall_at_[hidden])
Date: 2002-08-08 08:03:40
On Thursday 08 August 2002 12:10 pm, you wrote:
> From: "Dale Peakall" <dale.peakall_at_[hidden]>
> > On Wednesday 07 August 2002 4:54 pm, you wrote:
> > > I think so. Which is only evidence that the logic applied isn't
> > > necessarily the logic that everyone would apply, and thus the premise
> > > (that thread<void> would indicate nothrow semantics) is shaky at best.
> > I have to agree with Bill here. It just doesn't fit in my view of
> > "common sense" which means that as I'm clearly not alone it can't be
> > considered as entirely "obvious" semantics. To be honest, it looks,
> > smells and feels like a hack :-)
> I am not claiming that it is "obvious". I said that it is "logical", in the
> sense that when you see the explanation, you smile and think "So there _is_
> some twisted logic in that!" :-)
I'm glad we agree that it's not obvious, and with the help of your example I
can see how you might consider it logical, but I still don't believe that
it's right. Things should behave consistently.
Why should I allow exceptions to escape from a thread that returns a value,
but not from a thread that doesn't?
> > If you don't want your worker threads to cause your application to
> > terminate on unexpected exceptions catch(...) and add whatever logic is
> > appropriate to your application.
> No, I don't want my application to terminate on _expected_ exceptions
> thrown by the worker threads.
> double f(double x);
> double r;
> r = f(1.0) + f(2.0) + f(3.0);
> // ...
> I want to be able to transform this to:
> thread<double> tf1(bind(f, 1.0));
> thread<double> tf2(bind(f, 2.0));
> thread<double> tf3(bind(f, 3.0));
> r = tf1.join() + tf2.join() + tf3.join();
> // ...
OK, I can finally see why you might want an exception to escape from your
thread, and I can see why its "logical" to want this specifically when
dealing with threads that return values. But as stated above, I prefer
consistency over "twistic logic".
My thread-usage generally involve long-lived threads that are only joined as
part of tidy system shutdown and as I've stated I want my application to
terminate on uncaught exceptions in the thread as they always indicate an
error. Perhaps those of us who want this behaviour should use catch(...) and
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