Validating 10k hashes 1 thread vs 2 (mri, jruby, rbx results)

10k_multi_thread.rb

require 'dry-validation'
require 'active_model'
require 'benchmark'
require 'thread_safe'

schema = Class.new(Dry::Validation::Schema) do
  key(:name, &:filled?)
  key(:age) { |v| v.int? & v.gt?(18) }
end.new

class User
  include ActiveModel::Validations

  validates :name, presence: true
  validates :age, numericality: { greater_than: 18 }

  attr_reader :name, :age

  def initialize(attrs)
    @name, @age = attrs.values_at(:name, :age)
  end
end

count = 10_000
users = count.times.map { |i| { user: "User #{i}", age: 17 } }

Benchmark.bm do |x|
  x.report('DV: 1 thread') do
    DRY_ST_RESULT = users.map { |user| schema.(user).messages }
  end

  x.report('AM: 1 thread') do
    AM_ST_RESULT = users.map { |user| User.new(user).validate }
  end

  x.report('DV: 2 threads') do
    g1, g2 = users.each_slice(count/2).to_a

    DRY_MT_RESULT = ThreadSafe::Array.new

    t1 = Thread.new { DRY_MT_RESULT.concat(g1.map { |user| schema.(user).messages }) }
    t2 = Thread.new { DRY_MT_RESULT.concat(g2.map { |user| schema.(user).messages }) }

    t1.join
    t2.join
  end

  x.report('AM: 2 threads') do
    g1, g2 = users.each_slice(count/2).to_a

    AM_MT_RESULT = ThreadSafe::Array.new

    t1 = Thread.new { AM_MT_RESULT.concat(g1.map { |user| User.new(user).validate }) }
    t2 = Thread.new { AM_MT_RESULT.concat(g2.map { |user| User.new(user).validate }) }

    t1.join
    t2.join
  end
end

puts DRY_ST_RESULT.sort == DRY_MT_RESULT.sort
puts AM_ST_RESULT.to_a == AM_MT_RESULT.to_a

jruby.txt

       user     system      total        real
DV: 1 thread 10.610000   0.170000  10.780000 (  3.519302)
AM: 1 thread 18.670000   0.240000  18.910000 (  7.975311)
DV: 2 threads  3.280000   0.050000   3.330000 (  0.911350)
AM: 2 threads  7.950000   0.090000   8.040000 (  3.307048)

mri_2.3.txt

       user     system      total        real
DV: 1 thread  0.960000   0.010000   0.970000 (  0.977442)
AM: 1 thread  5.810000   0.040000   5.850000 (  5.897762)
DV: 2 threads  0.990000   0.010000   1.000000 (  1.005680)
AM: 2 threads  5.720000   0.040000   5.760000 (  5.786890)

rbx.txt

       user     system      total        real
DV: 1 thread  9.895571   0.119686  10.015257 (  5.208915)
AM: 1 thread 28.932377   0.286438  29.218815 ( 15.272448)
DV: 2 threads  7.118843   0.132064   7.250907 (  3.015258)
AM: 2 threads 20.210797   0.138119  20.348916 (  7.273697)