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Async+Await+Futures isn't needed at all, performs worse than a basic epoll loop, is more confusing, and less able to handle complex flow. But they add a lot of

Async+Await+Futures isn't needed at all, performs worse than a basic epoll loop, is more confusing, and less able to handle complex flow. But they add a lot of complexity. The futures paragidm makes the hard stuff almost impossible to do efficiently. It took c++ years to blow its complexity budge. Rust, "Hold my beer."

staticassertion 7y ago
> Async+Await+Futures isn't needed at all Define "needed" ? Code with async/await is radically simpler compared to without - this is not just basic sugar but really, really important due to rust's borrow semantics There is code I have written that required Rc/RefCell ceremony to get around the borrowchecker that will be completely handled by async/await. You can read more about this here: https://aturon.github.io/tech/2018/04/24/async-borrowing/ https://aturon.github.io/tech/2018/04/24/async-borrowing/ > performs worse than a basic epoll loop There are open issues and afaik all of these are solvable problems with known/ theorized solutions. > is more confusing, and less able to handle complex flow Sorry, that's absolutely just not the case Even if "confusing" is subjective, you can not tell me that writing complex loops/ control flow is easier in futures than in async/await. Just look at the examples here: https://docs.rs/dtolnay/0.0.4/dtolnay/macro._01__await_a_minute.html https://docs.rs/dtolnay/0.0.4/dtolnay/macro._01__await_a_min...
- woah 7y ago
  There are programmers who mostly work on code that does a lot of work with the CPU, and needs to be multi core. For these applications, async/await has little to offer. People who are puzzled by async/await often fall into this camp.
  - staticassertion 7y ago
    Why would they not just use threads?
jen20 7y ago
Async and await solve a different problem to epoll (and do so in a cross-platform manner). A “basic epoll loop” won’t help you for file IO on Linux, for example.

staticassertion 7y ago

> Async+Await+Futures isn't needed at all Define "needed" ? Code with async/await is radically simpler compared to without - this is not just basic sugar but really, really important due to rust's borrow semantics There is code I have written that required Rc/RefCell ceremony to get around the borrowchecker that will be completely handled by async/await. You can read more about this here: https://aturon.github.io/tech/2018/04/24/async-borrowing/ https://aturon.github.io/tech/2018/04/24/async-borrowing/ > performs worse than a basic epoll loop There are open issues and afaik all of these are solvable problems with known/ theorized solutions. > is more confusing, and less able to handle complex flow Sorry, that's absolutely just not the case Even if "confusing" is subjective, you can not tell me that writing complex loops/ control flow is easier in futures than in async/await. Just look at the examples here: https://docs.rs/dtolnay/0.0.4/dtolnay/macro._01__await_a_minute.html https://docs.rs/dtolnay/0.0.4/dtolnay/macro._01__await_a_min...

woah 7y ago
There are programmers who mostly work on code that does a lot of work with the CPU, and needs to be multi core. For these applications, async/await has little to offer. People who are puzzled by async/await often fall into this camp.
- staticassertion 7y ago
  Why would they not just use threads?

jen20 7y ago

Async and await solve a different problem to epoll (and do so in a cross-platform manner). A “basic epoll loop” won’t help you for file IO on Linux, for example.