Comment by jkelleyrtp
3 days ago
Creator here - haven't had a chance to write up a blog post yet! Stay tuned.
The gist of it is that we intercept the Rust linking phase and then drive `rustc` manually. There's some diffing logic that compares assembly between compiles and then a linking phase where we patch symbols against the running process. Works across macOS, Windows, Linux, iOS, Android, and WASM. On my m4 I can get 130ms compile-patch times, quite wicked stuff.
We handle the hard parts that the traditional dylib-reloading doesn't including TLS, statics, constructors, etc.
I've been posting demos of it to our twitter page (yes twitter, sorry...)
- With bevy: https://x.com/dioxuslabs/status/1924762773734511035
- On iOS: https://x.com/dioxuslabs/status/1920184030173278608
- Frontend + backend (axum): https://x.com/dioxuslabs/status/1913353712552251860
- Ratatui (tui apps): https://x.com/dioxuslabs/status/1899539430173786505
Our unfinished release notes are here:
https://github.com/DioxusLabs/dioxus/releases/tag/v0.7.0-alp...
More details to come!
[How] do you track when it's safe to delete the old version of a patched piece of code?
Edit: or, I guess since this doesn't seem to be something intended for use in prod, maybe that's not necessary. You can just bloat the runtime process more or less indefinitely.
I was curious because IIUC Linux kernel livepatches handle this via something related to RCU, which I guess is not possible in this context.
The axum example looks amazingly useful! Very cool project and idea.
can't access the xitter posts... is the axum part using the whole of dioxus or bare axum + code reloading?
There's a custom `axum::serve` equivalent we built that wraps the router construction in a hot-patchable function. When the patches are loaded, we reset the TCP connections.
It's a little specific to how dioxus uses axum today, but we plan to release an axum-only integration in the future.
awesome. thanks. i will definitely follow the project and hopefully participate. lack of hot reload for the FE folks is the biggest blocker we get from other options.