# File lib/resolv.rb, line 716
716:         def initialize(host, port=Port)
717:           super()
718:           @host = host
719:           @port = port
720:           @sock = TCPSocket.new(@host, @port)
721:           @sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::F_SETFD
722:           @senders = {}
723:         end

     # File lib/resolv.rb, line 749
749:         def close
750:           super
751:           @senders.each_key {|from,id|
752:             DNS.free_request_id(@host, @port, id)
753:           }
754:         end

     # File lib/resolv.rb, line 725
725:         def recv_reply
726:           len = @sock.read(2).unpack('n')[0]
727:           reply = @sock.read(len)
728:           return reply, nil
729:         end

     # File lib/resolv.rb, line 731
731:         def sender(msg, data, host=@host, port=@port)
732:           unless host == @host && port == @port
733:             raise RequestError.new("host/port don't match: #{host}:#{port}")
734:           end
735:           id = DNS.allocate_request_id(@host, @port)
736:           request = msg.encode
737:           request[0,2] = [request.length, id].pack('nn')
738:           return @senders[[nil,id]] = Sender.new(request, data, @sock)
739:         end