time-thread-contention.rb

def time_thread_contention(options = {})
  thread_count = options.fetch(:threads, 10)
  iterations = options.fetch(:iterations, 10)
  
  start_time = Time.now
  iterations.times.each_slice(thread_count).to_a.transpose.map do |idxs|
    Thread.new do
      idxs.each do |idx|
        yield
        Thread.pass if idx.odd?
      end
    end
  end.map(&:join)
  end_time = Time.now

  end_time - start_time
end

def time_thread_contention_compensated(options = {}, &block)  
  with = time_thread_contention(options, &block)
  without = time_thread_contention(options) { true }

  with - without
end