Using addprocs and pmap inside a function

General Usage
1

Heya,

Here’s a code file ex1.jl that does what it’s supposed to when I run julia ex1.jl:

module MWE
export gen_complicated_thing, do_para

function complicated_helper()
    return Dict()
end

function gen_complicated_thing(i)
    d = complicated_helper()
    d[i] = i
    return d
end

function do_para(n, numprocs) # numprocs doesn't do anything in this example
    arr = []
    for i in 1:n
        g = gen_complicated_thing(i)
        push!(arr, g)
    end
    return arr
end
end

using .MWE
println(gen_complicated_thing(19283)) # just checking gen_complicated_thing works
println(do_para(10, 2))

However, I want to parallelize the do_para function (none of the data depends on each other, so doing so is “trivial”). If I don’t set the numprocs inside the function and didn’t want a module, I could have a file ex2.jl:

using Distributed
addprocs(2)

@everywhere function complicated_helper()
    return Dict()
end

@everywhere function gen_complicated_thing(i)
    d = complicated_helper()
    d[i] = i
    return d
end

function do_para(n, numprocs) # numprocs doesn't do anything in this example
    arr = pmap(gen_complicated_thing, 1:10)
    return arr
end

println(gen_complicated_thing(19283)) # just checking gen_complicated_thing works
println(do_para(10, 2))

But this is not what I want.

So my question is, how do I set up my module to use addprocs and pmap inside do_para? I have to addprocs before @everywhere right? Do I need to reload a part of the module inside do_para so I can @everywhere what I need or something? Or is there another approach using something other than pmap?

Edit:
I could use Threads.@threads and julia -t 2 ex1.jl or something similar, but I would really like to specify the number of threads/processes inside the function.

function do_para(n, numprocs) # numprocs doesn't do anything in this example
    arr = Array{Any}(undef, n)
    Threads.@threads for i in 1:n
        g = gen_complicated_thing(i)
        arr[i] = g
    end
    return arr
end