API Request: number of processors (including threads)

[schlichtanders]

I saw that shard is able to compute the number of processors, optionally also including threads.

Dagger.jl/src/chunks.jl

Lines 176 to 198 in cec17a1

	function shard(@nospecialize(f); procs=nothing, workers=nothing, per_thread=false)
	if procs === nothing
	if workers !== nothing
	procs = [OSProc(w) for w in workers]
	else
	procs = lock(Sch.eager_context()) do
	copy(Sch.eager_context().procs)
	end
	end
	if per_thread
	_procs = ThreadProc[]
	for p in procs
	append!(_procs, filter(p->p isa ThreadProc, get_processors(p)))
	end
	procs = _procs
	end
	else
	if workers !== nothing
	throw(ArgumentError("Cannot combine `procs` and `workers`"))
	elseif per_thread
	throw(ArgumentError("Cannot combine `procs` and `per_thread=true`"))
	end
	end

It would be great if this could be available via an API like Dagger.nprocs

[jpsamaroo]

We now have Dagger.all_processors() and Dagger.compatible_processors(scope::Dagger.AbstractScope) for getting the set of processors, and so we could implement a Dagger.num_processors() that does what you ask. I would avoid overloading nprocs, since Distributed exports that as well (and we use it in Dagger internally).