[c++-pthreads] Re: thread-safety definition

[Ted Baker]

> ... the problem isn't with the model, but rather with the effect of that 
> model on existing code that all-too-casually and agressively eats 
> exceptions it doesn't understand. I think there are vanishingly few 
> circumstances where a blind catch(...) without an unconditional re-throw 
> should be considered "legitimate". If you don't completely understand 
> what an exception means, you cannot claim to have completely recovered, 
> and therefore cannot reasonably finalize propagation. (And when you 
> catch anonymously, you can't possibly understand what they mean since 
> you can't even identify them.) On the other hand, regardless of whether 
> the semantics are meaningful or reasonable, the syntax is legal and 
> apparently (unfortunately) in common use, so I can't dispute that you 
> need to consider that.

This problem could be eliminated by specifying that cancellation
is a special case, that cannot be caught by catch(...), i.e., that
it can only be caught by a handler that names it explicitly, or that
it cannot be caught at all.

--Ted