class Logger::LogDevice

def reopen(log = nil)
  # reopen the same filename if no argument, do nothing for IO
  log ||= @filename if @filename
  if log
    synchronize do
      if @filename and @dev
        @dev.close rescue nil # close only file opened by Logger
        @filename = nil
      end
      set_dev(log)
    end
  end
  self
end