Running Rust in WebAssembly in a Pool of Concurrent Web Workers in JavaScript


Your scientists were so preoccupied with whether or not they could, that they didn’t stop to think whether they should.

- Ian Malcolm

I would like to share a little experiment I did for no other reason than to show I could.

In this proof of concept application, the main application starts a pool of web workers that it later uses to offload a series of heavy tasks.

The task in question is to to render a single frame of a simple 3D scene using ray-tracing (path-tracing). The computationally intensive rendering is performed by a rust library compiled to WebAssembly.

These are the tools I used:

  • post-me to communicate with the workers using a Promise API: Blog - Github
  • My own toy ray tracing engine I implemented in rust a couple of years ago: Github
  • wasm-bindgen to compile rust to wasm and create js bindings: Github
  • Small in-house task queue to dispatch tasks to workers when available.
  • react for the scheleton of the app.

If you would like to run this madness, an instance of this application is deployed here.


If you would like to see the details of the implementation, you can find the source code of the app on Github


Using a similar approach, I also created an app that can detect the pitch of sounds being captured by the device’s microphone.

Try it out


Written on January 16, 2021