Savon Model and Thread safety

soap.rb

class Soap
  extend Savon::Model

  document "http://www.webservicex.net/CurrencyConvertor.asmx?WSDL"

  def thread_safe?
    p run_in_threads [:inr_to_usd, :usd_to_inr]
    sleep 5
    p run_in_threads [:usd_to_inr, :inr_to_usd]
  end

  def inr_to_usd
    convert 'INR', 'USD'
  end

  def usd_to_inr
    convert 'USD', 'INR'
  end

  private
  def convert from, to
    response = client.request 'http://www.webserviceX.NET/ConversionRate' do
      soap.input =  ['ConversionRate', {'xmlns' => 'http://www.webserviceX.NET/'}]
      soap.body = "<FromCurrency>#{from}</FromCurrency><ToCurrency>#{to}</ToCurrency>"
    end
    response[:conversion_rate_response][:conversion_rate_result]
  end

  def run_in_threads(method_names)
    threads = method_names.map do |method_name|
      Thread.new do
        Thread.current[:value] = Soap.new.send(method_name)
      end
    end
    sleep 10
    threads.each(&:kill)
    threads.collect{|th| th[:value]}.compact
  end
end