Async server example with Fibers

async_fibers.rb

require 'fiber'

module Stuff
  class << self

    def system_call_1
      f = Fiber.current
      EM.system 'delayedEcho dogs' do |result, status|
        f.resume result
      end
      Fiber.yield
    end

    def system_call_2
      f = Fiber.current
      EM.system 'delayedEcho pigs' do |result, status|
        f.resume result
      end
      Fiber.yield
    end

  end
end

class DragonflyServer
    
  def call(env)
    Fiber.new do
      
      res1 = Stuff.system_call_1
      res2 = Stuff.system_call_2
      env['async.callback'].call [200, {'Content-Type' => 'text/plain'}, [res1, res2]]
      
    end.resume

    [-1, {}, []]
  end
  
end

run DragonflyServer.new