Ruby threads Threads are executed in parallel while waiting for external command to finish.

benchmark

Using /home/kazjote/.rvm/gems/ruby-1.9.3-p327
➜  threads  time ruby threads.rb 1
ruby threads.rb 1  0.02s user 0.01s system 0% cpu 10.054 total
➜  threads  time ruby threads.rb 2
ruby threads.rb 2  0.02s user 0.02s system 0% cpu 6.049 total
➜  threads  time ruby threads.rb 4
ruby threads.rb 4  0.01s user 0.02s system 0% cpu 4.040 total
➜  threads  time ruby threads.rb 8
ruby threads.rb 8  0.02s user 0.02s system 1% cpu 3.037 total
➜  threads  time ruby threads.rb 16
ruby threads.rb 16  0.02s user 0.05s system 3% cpu 2.065 total
➜  threads  time ruby threads.rb 32 
ruby threads.rb 32  0.05s user 0.05s system 4% cpu 2.073 total

threads.rb

tasks = 10

threads = Array.new(ARGV.first.to_i) do
  Thread.new do
    while tasks > 0
      `sleep 1`
      tasks -= 1
    end
  end
end

threads.each(&:join)