"""Generate more file paths to process. Result are saved in _file_path_queue."""
        self._parsing_start_time = time.perf_counter()
        
        
        file_paths_in_progress = self._processors.keys()
        now = timezone.utcnow()
        
        list_mode = conf.get("scheduler", "file_parsing_sort_mode")
        files_with_mtime = {}
        file_paths = []
        is_mtime_mode = list_mode == "modified_time"
        file_paths_recently_processed = []
        file_paths_to_stop_watching = set()
        for file_path in self._file_paths:
            if is_mtime_mode:
                try:
                    files_with_mtime[file_path] = os.path.getmtime(file_path)
                except FileNotFoundError:
                    self.log.warning("Skipping processing of missing file: %s", file_path)
                    self._file_stats.pop(file_path, None)
                    file_paths_to_stop_watching.add(file_path)
                    continue
                file_modified_time = timezone.make_aware(datetime.fromtimestamp(files_with_mtime[file_path]))
            else:
                file_paths.append(file_path)
                file_modified_time = None