按照文檔說明reloadable設(shè)置為false，那么這個進程是不會被重啟的，但是源碼中，還是對這些進程進行重啟信號，代碼如下：

                // Send reload signal to all child processes.
                $reloadable_pid_array = array();
                foreach (static::$_pidMap as $worker_id => $worker_pid_array) {
                    $worker = static::$_workers[$worker_id];
                    if ($worker->reloadable) {
                        foreach ($worker_pid_array as $pid) {
                            $reloadable_pid_array[$pid] = $pid;
                        }
                    } else {
                        foreach ($worker_pid_array as $pid) {
                            // Send reload signal to a worker process which reloadable is false.
                            \posix_kill($pid, $sig);
                        }
                    }
                }

所以對reloadable設(shè)置為false的進程發(fā)送信號的意義是？