Swoole fatal error은(는) 무슨 뜻인가요?

register_shutdown_function('handleFatal');
function handleFatal()
{
    $error = error_get_last();
    switch ($error['type'] ?? null) {
        case E_ERROR :
        case E_PARSE :
        case E_CORE_ERROR :
        case E_COMPILE_ERROR :
            $message = $error['message'] . PHP_EOL;
            if (isset($_SERVER['REQUEST_URI'])) {
                $message .= '[QUERY] ' . $_SERVER['REQUEST_URI'];
            }
            // log or send:
            // error_log($message);
            // $server->send($fd, $message);
            break;
    }
}