Re: [boost] Re: first sight

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-01-15 08:33:31

From: "bill_kempf" <williamkempf_at_[hidden]>
> --- In boost_at_y..., "Peter Dimov" <pdimov_at_m...> wrote:
> > FWIW here's an old proposal of mine:
> >
> > http://groups.yahoo.com/group/boost/message/16471
>
> Yes, this old thread has been used to solidify my working mental
> design.  However, there are issues to work through:
>
> A) Can the user catch the exception? (Probably the only choice
> available for Boost.Threads.)

Yes.

> B) Can the user "eat" the exception?

Yes.

> C) How do you portably and efficiently handle cancellation points?
>
> (A) is probably the easiest, though the only viable choice is frought
> with problems.  If user code has catch(...) blocks it may well cause
> hard to diagnose bugs, and if this code is in a library the user may
> not be able to work around the bugs.  I expect this is something
> we'll just have to live with, and practice may prove it to be a non-
> issue, but it still concerns me.
>
> (B) has pros and cons for both choices and needs some serious thought.
>
> (C) is the biggest issue.  The thread_ref you refer to below failed
> in this regard.  Cancellation requests should really cause instant
> cancellation during such blocking operations.  However, doing this in
> a portable manner, especially one that doesn't add overhead to such
> operations, is very difficult to do.

No, thread_ref did not fail. An existing implementation that approximates
the "truth" to the extent of being useful is better than a perfect
implementation that does not exist yet.

--
Peter Dimov
Multi Media Ltd.