webpki VS tokio

Beyond that, various things like the ScyllaDB driver are using OpenSSL because WebPKI doesn't support validating connections to IP addresses (as opposed to DNS names) and RusTLS currently delegates to WebPKI.

There's a JIT framework in Rust: https://github.com/bytecodealliance/wasmtime

There's a library for doing full X.509 certificate parsing and verification: https://briansmith.org/rustdoc/webpki/

There's definitely some attempts at doing pure-Rust SSL, but I suspect a lot of them are also doing some sketchy things with crypto that shouldn't be trusted (getting constant-time stuff implemented properly is really challenging, and probably requires large amounts of assembly to guarantee correctness).

An issue was raised with webpki to support the IP addressees 5 years ago, and yet it's still not there. What do people use to overcome the fact that rustls can't do IP-based client connections because of it? My guess would be, they are switching to native-tls or openssl-tls.

Yes, rustls currently doesn't support certificates without hostnames (only an IP); this is actually an issue with the webpki crate, and work to solve it is ongoing (will hopefully land in a release in a few months or so).

> Bundling this set with Firefox

I love that they did that; it was actually my idea (https://bugzilla.mozilla.org/show_bug.cgi?id=657228). I believe the list is pretty large and changes frequently and so they download it dynamically.

> short cut to a "Yes"

Do they really do that? That's awesome if so. Then they don't even need to ship the roots.

> I specifically don't like [...] saying "unknown issuer"

https://github.com/briansmith/webpki/issues/221

> If std::fs::File::open() gives me Result with an io:Error that claims "File not found" but the underlying OS file open actually failed due to a permission error, you can see why that's a problem right? Even if this hypothetical OS doesn't expose any specific errors, "File not found" is misleading.

A more accurate analogy: You ask to open "example.txt" without supplying the path, and there is no "example.txt" in the current working directory. You will get "file not found."

Regardless, I agree we could have a better name than UnknownIssuer for this error.

Being able to control nondeterminism is particularly useful for testing and debugging. This allows creating reproducible test environments, as well as discrete-event simulation for faster-than-real-time simulation of time delays. For example, Cardano uses a simulation environment for the IO monad that closely follows core Haskell packages; Sui has a simulator based on madsim that provides an API-compatible replacement for the Tokio runtime and intercepts various POSIX API calls in order to enforce determinism. Both allow running the same code in production as in the simulator for testing.

tokio / hyper / toml / serde / serde_json / json5 / console

tokio - An asynchronous runtime for Rust

3. Tokio

The AWS SDK makes use of the async capabilities in the Tokio library. So when you see async in front of a fn that function is capable of executing asynchronously.

Petar is also looking at implementing concurrency the way it is in Go to have a fully functional virtual machine as it is in the spec. This would likely attract more external contributors to developing the VM. One advantage of Rust is that, with the concurrency model, there is already an extensive library called Tokio which he can use. Petar stresses that this isn’t easy, but he believes it’s achievable, at least as a research topic around determinism and concurrency.

Another thing to point out is that async is a thing in Rust. I'm not going to begin to dive into this paradigm in this article, but know it's handled by the awesome Tokio framework.

So I started by using Tokio, a popular async runtime. The docs and samples helped me get a simple outbound TCP connection working. The Rust async book also had a lot of good explanations, both practical and digging into the details of what a runtime does.

Regarding the quote:

> The Original Sin of Rust async programming is making it multi-threaded by default. If premature optimization is the root of all evil, this is the mother of all premature optimizations, and it curses all your code with the unholy Send + 'static, or worse yet Send + Sync + 'static, which just kills all the joy of actually writing Rust.

Agree about the melodramatic tone. I also don't think removing the Send + Sync really makes that big a difference. It's the 'static that bothers me the most. I want scoped concurrency. Something like <https://github.com/tokio-rs/tokio/issues/2596>.

Another thing I really hate about Rust async right now is the poor instrumentation. I'm having a production problem at work right now in which some tasks just get stuck. I wish I could do the equivalent of `gdb; thread apply all bt`. Looking forward to <https://github.com/tokio-rs/tokio/issues/5638> landing at least. It exists right now but is experimental and in my experience sometimes panics. I'm actually writing a PR today to at least use the experimental version on SIGTERM to see what's going on, on the theory that if it crashes oh well, we're shutting down anyway.

Neither of these complaints would be addressed by taking away work stealing. In fact, I could keep doing down my list, and taking away work stealing wouldn't really help with much of anything.

The PHP <-> Rust bindings are provided by https://github.com/Nicelocal/ext-php-rs/ (our fork of https://github.com/davidcole1340/ext-php-rs with a bunch of UX improvements :).

php-tokio's integrates the https://revolt.run event loop with the https://tokio.rs event loop; async functionality is provided by the two event loops, in combination with PHP fibers through revolt's suspension API (I could've directly used the PHP Fiber API to provide coroutine suspension, but it was a tad easier with revolt's suspension API (https://revolt.run/fibers), since it also handles the base case of suspension in the main fiber).