gistfile1.txt

# solver.jl
module Solver

    export solve

    function solve_sub()
        y = rand(1000,1000)
        for busy = 1:100
            y *= 10
            y /= 10
        end
        return mean(y)
    end


    function solve()
        remote_busy = false
        remote_result = nothing
        
        for iter = 1:100
            x = rand(1000,1000)
            x = 10*x
            x = 10*x
            x = 10*x
            x = 10*x
            x = 10*x
            x /= 100000
            avg = mean(x)

            print(iter, " ", avg, " ", remote_busy)

            if avg < 0.5 && !remote_busy
                println(" starting sub")
                remote_result = @spawnat 2 solve_sub()
                remote_busy = true
            end
            
            @time ready = remote_busy && isready(remote_result)

            if ready
                res = take!(remote_result)
                print(" got result $res")
                remote_busy = false
            end

            println()
        end
    end
end


# Then another file test.jl
using Solver

solve()


# julia -p 2 test.jl

1 0.499949244417727 false starting sub
elapsed time: 1.256024145 seconds (1540584 bytes allocated)
 got result 0.4998042450174787
2 0.5005155793905703 falseelapsed time: 1.49e-7 seconds (0 bytes allocated)

3 0.49979916948467273 false starting sub
elapsed time: 1.165724098 seconds (10376 bytes allocated)
 got result 0.5000743191124121
4 0.49987534612626455 false starting sub
elapsed time: 1.162399819 seconds (8088 bytes allocated)
 got result 0.5000267495200585
5 0.5003024117948347 falseelapsed time: 1.48e-7 seconds (0 bytes allocated)

6 0.5001057455369299 falseelapsed time: 1.91e-7 seconds (0 bytes allocated)

7 0.49977373772910283 false starting sub
elapsed time: 1.168619742 seconds (8088 bytes allocated)
 got result 0.5002357213152845
8 0.4999847640256721 false starting sub
elapsed time: 1.165707928 seconds (9704 bytes allocated)
 got result 0.5002197985300247
9 0.4997749590974831 false starting sub
elapsed time: 1.162779257 seconds (9704 bytes allocated)
 got result 0.4999976924032774
10 0.4996215802466504 false starting sub

# which shows how it blocks

try wait(remote_result) at L38