Expose cpuCount

[slorber]

This lib computes physical CPUs for pool default values, but this computed value is not exposed.

Exposing it gives the possibility for the user to create more advanced algorithms to define the appropriate number of threads.

I'm not sure what name to use for the export, just wanted to open the discussion that I'd like to access that value.

[AriPerkkio]

I'm not sure what's the use case here. I think users should rather check their host environment and pass the minThreads and maxThreads options to Tinypool. They can use any custom logic they want to compute values for those options.

[slorber]

Agree, this was before I knew about os.availableParallelism() and how you use it in Vitest:

https://github.com/vitest-dev/vitest/blob/b997355be71220c098563b1a60056eb57f4d4d90/packages/vitest/src/node/pools/threads.ts#L46-L71

  const numCpus
    = typeof nodeos.availableParallelism === 'function'
      ? nodeos.availableParallelism()
      : nodeos.cpus().length

I wanted it to be exposed because I didn't know availableParallelism(). Now I wonder what prevents you to use this API instead of this logic: https://github.com/tinylibs/tinypool/blob/main/src/physicalCpuCount.ts

I guess it requires a breaking change, bumping the Node version.