shutdown

# File activesupport/lib/active_support/testing/parallelization.rb, line 49
      def shutdown
        dead_worker_pids = @worker_pool.filter_map do |pid|
          Process.waitpid(pid, Process::WNOHANG)
        rescue Errno::ECHILD
          pid
        end
        @queue_server.remove_dead_workers(dead_worker_pids)

        @queue_server.shutdown
        @worker_pool.each do |pid|
          Process.waitpid(pid)
        rescue Errno::ECHILD
          nil
        end
      end