gistfile1.txt

def measuring(thread_mode, lock)
  case thread_mode
  when :single_threaded
    yield
  when :multi_threaded
    lock.start
    yield
    lock.stop
  else
    raise "not supported thread mode: #{thread_mode.inspect}"
  end
end

def measure(thread_mode, lock)
  start = Time.now
  measuring(thread_mode, lock) do
    100_000.times do
      lock.lock_and_unlock
    end
  end
  elapsed_time = Time.now - start

  label = [lock.backend, thread_mode].join(", ")
  result = format("%-40s: %1.9f seconds", label, elapsed_time)
  puts(result)
end

class Lock
  def start
    @continue = true
    @thread = Thread.new do
      while @continue
        lock_and_unlock
      end
    end
  end

  def stop
    @continue = false
    @thread.join
  end

  def lock_and_unlock
    lock
    unlock
  end
end

class RubiniusLock < Lock
  def lock
    Rubinius.lock(self)
  end

  def unlock
    Rubinius.unlock(self)
  end

  def backend
    'Rubinius.{lock,unlock}'
  end
end

class ChannelLock < Lock
  def initialize
    @lock = Rubinius::Channel.new
    @lock.send(nil)
  end

  def lock
    @lock.receive
  end

  def unlock
    @lock.send(nil)
  end

  def backend
    'Channel#{receive,send}'
  end
end

5.times do
  [:single_threaded, :multi_threaded].each do |thread_mode|
    channel_lock = ChannelLock.new
    measure(thread_mode, channel_lock)
    rubinius_lock = RubiniusLock.new
    measure(thread_mode, rubinius_lock)
  end
  puts
end