public static function tick(float $ms, callable $callback, $params = null)
    {
        $tid = Timer::tick($ms, $callback, $params);

        // save meta info
        self::$timers[$tid] = [
            'type'     => 'tick',
            'ctime'    => \time(), // add time.
            'interval' => $ms,
        ];

        return $tid;
    }