Asynchronous vs synchronous

gistfile1.rb

require 'eventmachine'
require 'benchmark'

rand_iterations = 10

define_method(:generate_func) do
  # This is so we have n different function objects, which seems more realistic
  proc { rand_iterations.times { rand(0..10) } }
end

[0, 100_000, 200_000, 500_000, 1_000_000].each do |n|
  
  puts "#{n}:\n"
  
  Benchmark.bm do |x|
    x.report("Async ordered:") do
      EM.run do
        n.times.map { generate_func }.inject(proc{ EM.stop }) do |memo, func|
          proc { EM.next_tick { func.call; memo.call } }
        end.call
      end
    end
    
    x.report("Async non-ordered:") do
      EM.run do
        n.times.map { generate_func }.each do |func|
          EM.next_tick { func.call }
        end
        EM.next_tick { EM.stop } # Does this guarantee to run the above functions first?
      end
    end
    
    x.report('Sync:') do
      EM.run do
        n.times.map { generate_func }.each { |func| func.call  }
        EM.stop
      end
    end
    
  end
  
  puts "\n"
end

0:
       user     system      total        real
Async ordered:  0.000000   0.000000   0.000000 (  0.119964)
Async non-ordered:  0.000000   0.000000   0.000000 (  0.000108)
Sync:  0.000000   0.000000   0.000000 (  0.090405)

100000:
       user     system      total        real
Async ordered:  1.100000   0.300000   1.400000 (  1.405504)
Async non-ordered:  0.600000   0.060000   0.660000 (  0.657613)
Sync:  0.460000   0.010000   0.470000 (  0.569028)

200000:
       user     system      total        real
Async ordered:  2.250000   0.590000   2.840000 (  2.834279)
Async non-ordered:  1.340000   0.110000   1.450000 (  1.454296)
Sync:  0.720000   0.010000   0.730000 (  0.811283)

500000:
       user     system      total        real
Async ordered:  6.340000   1.810000   8.150000 (  8.198080)
Async non-ordered:  3.740000   0.430000   4.170000 (  4.169899)
Sync:  2.410000   0.150000   2.560000 (  2.666942)

1000000:
       user     system      total        real
Async ordered: 14.330000   3.380000  17.710000 ( 17.754995)
Async non-ordered:  8.400000   1.520000   9.920000 (  9.917599)
Sync:  4.920000   0.110000   5.030000 (  5.137152)

Graph: https://docs.google.com/spreadsheets/d/1zH7SQA8HBRC-WPN9s3uUr718xAvJhr2lWp7VHyx9gdU/edit?usp=sharing