Re: [boost] [boost.async] Some questions

niedz., 13 sie 2023 o 11:32 Andrzej Krzemienski napisał(a):

Hi Everyone, I would like to thank Klemens for writing and sharing this library. I am sure the community needs a higher level library for asynchronous computations based on C++20 coroutines. Boost.Async addresses the need. I would like to ask a couple of questions to better understand the design goals and the scope of the library.

Q1. Is single-threaded-ness the design goal? Or is the plan to enable multi-threaded use cases? There is a GitHub issue ( https://github.com/klemens-morgenstern/async/issues/19) suggesting the latter.

Q2. Reading through the docs, I get an impression that Boost.Async is "Either a wrapper over ASIO, or an isolated usage for a generator". They seem like two unrelated worlds. The former requires a hard prerequisite of having a Boost.ASIO library (with Boost version at least 1.82). The latter can hardly be called "asynchronous". Generators, the way I understand them, are perfectly synchronous. Is this impression correct?

The following are more remarks regarding the choice of names.

Q3. The docs say that `promise` and `task` differ primarily by their level of eagerness. But the names do not seem to reflect this. What is the rationale or the intuition behind those names?

R1. I find the name `use_op` uninformative. The examples in documentation suggest that it is an *adapter*: they change the Boost.ASIO interface into the Boost.Async interface. Is that correct?

One more question. This interface of async::generator, taking two parameters, where one can not only generate values from the generator, but also obtain values: is there a real-life use case for this? I tried to use it, but the order of events seems impractical: in order to generate a new value I have to feed a value: auto output = co_await generator(input); But in the generator, I cannot use the provided input to generate the output. The output corresponding to the passed input would only be accessible upon the subsequent co_await. Regards, &rzej;