Using onMessage and postMessage in a worker and main thread

[ari62]

Hello, please provide an example of using onMessage and postMessage from both the worker side and the main thread side using Typescript. The object returned from spawn doesn't seem to include those methods and I dont see how to call them from within expose as well.

Thank you

[andywer]

Hey @ari62. You are not supposed to use the worker directly when using threads.js.

What's your use case that you want to go low-level?

[ari62]

Hi Andy, I think what i was trying to do is use setInterval to do a repeated task in a thread and then send a message to the thread to stop the setInterval. I think if I just stop the thread (using Thread.terminate) and don't call clearInterval, I risk memory leaks. I also needed to send data from the thread to the originating code. I guess any use case where you need to send a message to a thread or from a thread to the originating code would be the general use case for posting message both to and from threads.

[andywer]

Ahhh, in this case what you want is #273 😉

Because using the low-level postMessage seems like a rather bad idea. For your use case, however, I don't see a need for any of that. Why not just do something like this?

// worker code
import { expose } from "threads/worker"

const interval = setInterval(doStuff, 1234)

expose({
  // …
  stop() {
    clearInterval(interval)
  }
})

Btw, I don't think you're at risk of memory leaks if you call Thread.terminate() as you terminate the whole thread anyway. That should free up all resources used by the thread.