require 'eventmachine' require 'em-http' require 'fiber' # Using Fibers in Ruby 1.9 to simulate blocking IO / IO scheduling # while using the async EventMachine API's def async_fetch(url) f = Fiber.current http = EventMachine::HttpRequest.new(url).get :timeout => 10 http.callback { f.resume(http) } http.errback { f.resume(http) } return Fiber.yield end EventMachine.run do Fiber.new{ puts "Setting up HTTP request #1" data = async_fetch('http://www.google.com/') puts "Fetched page #1: #{data.response_header.status}" puts "Setting up HTTP request #2" data = async_fetch('http://www.yahoo.com/') puts "Fetched page #2: #{data.response_header.status}" EventMachine.stop }.resume end puts "Done" # Setting up HTTP request #1 # Fetched page #1: 302 # Setting up HTTP request #2 # Fetched page #2: 200 # Done