`init_thread_pool(0)` will freeze the worker with no error

[zxch3n]

Expected behavior

Switching to optimal thread number or throwing an error.

[RReverser]

Adding an error makes sense, but I wonder how/why did you pass 0 in real-world code.

[zxch3n]

I thought the behavior would be the same as Rayon's num_threads API.

If num_threads is 0, or you do not call this function, then the Rayon runtime will select the number of threads automatically. At present, this is based on the RAYON_NUM_THREADS environment variable (if set), or the number of logical CPUs (otherwise).

And many other thread-related APIs also use 0 or -1 to select the number of threads automatically. No idea whether it's possible in the browser context though.

This behavior can be learned during development, but document or error messages can be very helpful.

And thanks for this tool! It's really amazing.

[RReverser]

Ah interesting.

I kind of wanted to keep number of threads manual to make sure that users don't get code bloat from automatic detection, so for now I'm leaning towards making this a clear error rather than automatic detection. I believe Rayon also said in their docs that default behaviour can change in future and users should pass explicit number of threads too.

Need to check how to do it without also significant code bloat though.

[RReverser]

If you want to send a PR to add such error, that would be welcome too btw.

[zxch3n]

Ok, I'll submit a PR~