new

# File activesupport/lib/active_support/evented_file_update_checker.rb, line 73
      def initialize(files, dirs)
        @files = files.map { |file| Pathname(file).expand_path }.to_set

        @dirs = dirs.each_with_object({}) do |(dir, exts), hash|
          hash[Pathname(dir).expand_path] = Array(exts).map { |ext| ext.to_s.sub(/\A\.?/, ".") }.to_set
        end

        @common_path = common_path(@dirs.keys)

        @dtw = directories_to_watch
        @missing = []

        @updated = Concurrent::AtomicBoolean.new(false)
        @mutex = Mutex.new

        start
        @after_fork = ActiveSupport::ForkTracker.after_fork { start }
      end