async-std VS rio

But maybe check out the discussion here https://github.com/async-rs/async-std/pull/631 or something (the blog post was linked on the end of it)

Have a look at these: https://github.com/async-rs/async-std/tree/main/examples

In fact, there are a lot of crates in Rust where in other programming languages, it would be included in the standard library. Examples are regex, random number generators, additional iterator methods, macros for other collections, num traits, loggers, HTTP libraries, error handling, async runtimes, serialization and deserialization, date and time, and many more.

Two major projects (non std lib but extremely commonly used) stand out in the area of async programming: Async std and Tokio - no doubt familiar to anyone that has turned an eye towards Rust for a second too long. Async architecture in general is likely very familiar to JavaScript programmers but in Rust there are some extra considerations (like ownership of the data that is thrown into an async function). Tokio is fast becoming a heavily supported and road tested async framework, with a thread scheduling runtime "baked in" that has learned from the history of Go, Erlang, and Java thread schedulers.

Ah... https://github.com/tokio-rs/tokio and https://github.com/async-rs/async-std ?

async-std: Basically a Tokio alternative with a few different design decisions.

Go's solution is for the scheduler to notice after a while when a goroutine has blocked execution and to shift goroutines waiting their turn to another thread. async-std pondered a similar approach with tasks, but it proved controversial and was never merged.

This indicates curl, zlib, openssl, and libnghttp2 as well as a bunch of WASM-related things are being dynamically linked into my executable. To resolve this, I looked at the build features exposed by surf and found that it selects the "curl_client" feature by default, which can be turned off and replaced with "h1-client-rustls" which uses an HTTP client backed by rustls and async-std and no dynamically linked libraries. Enabling this build feature removed all -sys dependencies from androidx-release-watcher, allowing me to build static executables of it.

And also, the actual PR never got merged.

Async in rust needs a runtime (aka executor) to run. You can maybe get a better description from the rust docs. As an example, Tokio attempts to provide an interface for a developer that is minimal change to the more common blocking code. So you'd end up putting #[tokio::main] above your main function to spin up the executor and most of the rest of the code is similar to a non-async version with a few sprinkles of .await, which you can see in the hello world for tokio. In contrast, async-std provides a more hands-on/low-level approach. If you are unlucky enough to have libraries that choose different stacks to work on, you'll possibly (probably?) have to handle both.

Also, not to be too bad about a reputation fallacy, but I found the author to be flippant and disrespectful when good-faith unsoundness was pointed out in his crates: https://github.com/spacejam/rio/issues/30

In my previous post on linear types I spent quite a bit of time motivating linear types. For example the ergonomic rio io_uring library could be made sound if it could guarantee destructors are run. Or performing FFI with async C++ could be made more efficient if it could rely directly on destructors rather than having to involve an intermediate runtime for each call.

It's like cargo should have a way to mark a dependency as unsafe. That way, you could have a safe mmap crate as an unsafe dependency. Or something like rio which is deliberately unsound (but is fine if you abide by its rules through the entirety of the program)

for completeness there is also rio, but:

rio still has known soundness issues– its Completion futures block the thread when dropped (!!!), and can allow for use-after-free bugs if leaked. See https://github.com/spacejam/rio/issues/30 for details.

Here are some posts about the design. https://without.boats/blog/io-uring/ https://github.com/spacejam/rio/issues/30 https://github.com/axboe/liburing/issues/109

The author of sled[1], an embedded database in Rust which has a number of promising features, has also written parts of rio[2], an underlying pure Rust io_uring library, which is intended to become the core write path for sled. rio has support for files but also has a demo for TCP (on Linux 5.5 and later) and O_DIRECT.

I tested rio recently as I had a Brilliant but Bad Idea™ involving file access and was pleasantly surprised by the API, as I have been with sled's.

I'm excited for the experimentation in the Rust ecosystem and for such low level crates to handle the complex io_uring tasks (relatively) safely!

[1]: https://github.com/spacejam/sled

[2]: https://github.com/spacejam/rio