gistfile1.rb

require 'rubygems'
require 'eventmachine'
require 'em-http'
require 'dataflow'
 
Thread.new {
  EM.run{}
}
 
module EventMachine
  module DataflowDeferrable
    include Dataflow
    declare :results
 
    def succeeded?
      barrier results
      @deferred_status == :succeeded
    end
 
    def failed?
      barrier results
      @deferred_status == :failed
    end
 
    def set_deferred_status(status, *args)
      @deferred_status = status
      unify results, @deferred_args
    end
  end
end
 
class EventMachine::HttpClient
  include EventMachine::DataflowDeferrable
end
 
def dataflow_http
  results = %w(http://www.yahoo.com/ http://www.slashdot.org/ http://www.github.com/ http://www.oib.com/).map do |url|
    EventMachine::HttpRequest.new(url).get
  end
 
  results.each do |http|
    if http.succeeded?
      p http.response
    else
      p "bad stuff happened"
    end
  end
end
 
dataflow_http