set_non_blocking

# File lib/webrick/utils.rb, line 23
    def set_non_blocking(io)
      flag = File::NONBLOCK
      if defined?(Fcntl::F_GETFL)
        flag |= io.fcntl(Fcntl::F_GETFL)
      end
      io.fcntl(Fcntl::F_SETFL, flag)
    end