want the relationshiop between EM-Synchrony 、em-http-request and fiber 's?

i want to concurrency download web pages so i found these libs,

but i can't distinguish the relationship between em-synchrony and em-http-request?

i had checkout the github of each repository,but it seems all example is about eachself,

but from some article,it seems em-synchrony and em-http-request can use together,but i didn't found relevent code

how to write this demo code ,thanks

EM-Synchrony contains the code to make EM-HTTP-Request use fibers. It's in https://github.com/igrigorik/em-synchrony/blob/master/lib/em-synchrony/em-http.rb. So, once you've required em-synchrony/em-http you're em-http-request calls will be using fibers unless you call the a* versions that get created.

So, something along the lines of:

require 'rubygems'
require 'em-synchrony'
require 'em-synchrony/em-http'

EM.synchrony do
  req = EM::HttpRequest.new('http://www.google.com').get
  p req
end