pmap

pmap.rb

# coding utf-8

class Array
  def pmap
    pipes, out = [], []

    each do |e|
      r, w = IO.pipe
      Process.fork do
        r.close
        res = yield(e)
        w.write(Marshal.dump(res))
      end
      w.close
      pipes << r
    end

    Process.waitall
    pipes.each do |p|
      out << Marshal.load(p.read)
      p.close
    end
    out
  end # end pmap
end # end Array

require 'benchmark'

seconds = Benchmark.realtime do
  test = [1, 2, 3].pmap do |x|
    sleep x
    x**x
  end
  p test
end

puts "work #{seconds} seconds"