tokio VS async-std

Previously, Edge Functions with large dependencies or doing preparation work at the start (e.g., parsing/loading configs, initializing AI models) would incur a noticeable boot delay. Sometimes, these slow neighbors can impact other functions running on the same machine. All JavaScript workers in the Supabase Edge Functions Runtime were cooperatively scheduled on the same Tokio thread pool. If one worker had heavy startup logic, such as parsing JavaScript modules or running synchronous operations, it could delay every worker scheduled after. This led to occasional long‑tail latency spikes in high-traffic projects. To address this issue, we moved workers which are still performing initial script evaluation onto a dedicated blocking pool. This approach prevents heavy initialization tasks from blocking the Tokio thread, significantly reducing boot time spikes for other functions.

docs.rs is just barely viable because it only has to build crates once (for one set of features, one target platform etc.).

What you propose would 1) have to build each create for at least the 8 Tier 1 targets, if not also the 91 Tier 2 targets. That would be either 8 or 99 binaries already.

Then consider that it's difficult to anticipate which feature combinations a user will need. For example, the tokio crate has 14 features [1]. Any combination of 14 different features gives 2^14 = 16384 possible configurations that would all need to be built. Now to be fair, these feature choices are not completely independent, e.g. the "full" feature selects a bunch of other features. Taking these options out, I'm guessing that we will end up with (ballpark) 5000 reasonable configurations. Multiply that by the number of build targets, and we will need to build either 40000 (Tier 1 only) or 495000 binaries for just this one crate.

Now consider on top that the interface of dependency crates can change between versions, so the tokio crate would either have to pin exact dependency versions (which would be DLL hell and therefore version locking is not commonly used for Rust libraries) or otherwise we need to build the tokio crate separately for each dependency version change that is ABI-incompatible somewhere. But even without that, storing tens of thousands of compiled variants is very clearly untenable.

Rust has very clearly chosen the path of "pay only for what you use", which is why all these library features exist in the first place. But because they do, offering prebuilt artifacts is not viable at scale.

[1] https://github.com/tokio-rs/tokio/blob/master/tokio/Cargo.to...

Currently, the de facto standard async runtime is tokio. Beginners can just use tokio without much thought.

Gotham is a flexible web framework built for stable Rust that promotes “stability, safety, security, and speed.” It provides async support with the help of Tokio and hyper out of the box.

Because of the nature of Kubernetes and its operation being "network operations", kube-rs considers all the operations as "async" operations, and we need a way to manage it. The well-known and mostly used way of doing it is with the tokio framework. Adding tokio, with features of "macros" (to use macros like #[tokio::main]) and a runtime (rt-multi-thread) should be enough. Additionally, we need to return an error to this function, so we will be using anyhow crate, that allows us to return errors without worrying about the error type

The situation in Rust seems to be pretty complicated. But I did find that panicking within a thread you spawn kills just that thread and not the whole program. And it seems that Tokio has the same behavior.

https://github.com/tokio-rs/tokio/issues/2002

And web frameworks like Tower provide standard ways of Helen’ handling panics and turning them into error responses.

https://docs.rs/tower-http/latest/tower_http/catch_panic/ind...

So I don’t think panics are necessarily meant to be program-killing in Rust, even if Result types are heavily recommended instead.

There's compiler-level traits like `Iterator` and `Future` which enforce references. If wanting to do intrusive pointers into them, one risks creating overlapping references: https://github.com/tokio-rs/tokio/issues/3399

Full Tokio compatibility

Certainly! Check out the official Diesel documentation and the async-std Rust chapter to familiarize yourself with async Rust programming.

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.