new

# File activesupport/lib/active_support/evented_file_update_checker.rb, line 75
      def initialize(files, dirs)
        gem_paths = Gem.path
        files = files.map { |f| Pathname(f).expand_path }
        files.reject! { |f| f.to_s.start_with?(*gem_paths) }
        @files = files.to_set

        @dirs = dirs.each_with_object({}) do |(dir, exts), hash|
          next if dir.start_with?(*gem_paths)
          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
        # inotify / FSEvents file descriptors are inherited on fork, so
        # we need to reopen them otherwise only the parent or the child
        # will be notified.
        # FIXME: this callback is keeping a reference on the instance
        @after_fork = ActiveSupport::ForkTracker.after_fork { start }
      end