[cpp-threads] Asynchronous Execution Issues (caching_async)

[Lawrence Crowl]

On 5/1/09, Anthony Williams <anthony at justsoftwaresolutions.co.uk> wrote:
> At Fri 01 May 2009 22:34:17 BST, "Boehm, Hans" <hans.boehm at hp.com> wrote:
> > Here's a draft of a paper on these issues that Lawrence and I
> > are about to submit.
>
> Sorry for my lack of reply earlier. I didn't see the messages
> until now.
>
> I'm concerned about removing detach(). It makes it very hard
> (if not impossible) to write a simple async function without
> using a thread pool unless one also has a wait-for-the-thread
> variant of a future. Even with a wait-for-the-thread future,
> what happens if no-one waits? Do we get a thread leak? Join on
> destruction? Throw on destruction?

I would join on destruction, because I expect the destruction to
happen without the wait mostly when the wait is bypassed by an
exception, and I'd rather not put an exception in a destructor.

> Also, people will expect detach().  Boost has it.  POSIX has it.
> Both have destructors for thread-locals.  This would be seen as
> a big step backwards.

We need to ensure that C++0x can solve the problems for which
others used detach.  A careful analysis of examples might yield
some interesting insights.

-- 
Lawrence Crowl