# File lib/spring/sid.rb, line 23
    def self.sid
      @sid ||= begin
        if Process.respond_to?(:getsid)
          # Ruby 2
          Process.getsid
        elsif defined?(Fiddle) and defined?(DL)
          # Ruby 1.9.3 compiled with libffi support
          fiddle_func.call(0)
        else
          # last resort: shell out
          `ps -p #{Process.pid} -o sess=`.to_i
        end
      end
    end