Re: [boost] Asynchronous library now in Boost Library Incubator

Subject: Re: [boost] Asynchronous library now in Boost Library Incubator
From: Thomas Heller (thom.heller_at_[hidden])
Date: 2016-11-30 16:27:24

On Mittwoch, 30. November 2016 21:47:34 CET Christophe Henry wrote:
> >After having a deeper dive into the documentation and examples, one
> >pattern I see popping up quite
> >frequently is this:
> >future<R> fut = my_promise.get_future();
> >post_callback(some_work, [this](expected<R> r) {
> >this->my_promise.set_value(r.get()); });
> >return fut;
> 
> This is simply to make examples easier to run (it finishes the example). It
> demonstrates that the only one which blocks in an application built on
> Asynchronous is main().
> This might be more confusing than useful and I probably should get rid of
> this.

Understood. It's always a difficult task to present clear and good examples and 
best practices.

Out of curiosity (I can't recall reading that in the documentation, correct me 
if I am wrong), how is a real and complex application supposed to signal 
shutdown/completion?
The answer to this question is somehow important. You make it very clear, in 
the documentation and here in this thread, that having a chain of future.then 
(which conceptually really are just callbacks that are called whenever the 
future became ready), is not the way to go because eventually you need to 
block the thread of execution. At least as your very last call main, for 
example.
Joining the threads of your active threadpools also blocks the thread of 
execution. So where is the difference? Which technique did I miss?