onMessage回调中实例化类和静态方法内存消耗差别怎么这么大？这是为何？

public function onMessage(TcpConnection $c, Request $request): void
{
        .....
        //执行控制器
        //$res = $controller::$action($c->army); //调用静态方法内存使用正常
         $res = (new $controller)->$action($c->army);//用new实例化，内存持续增长
         $c->close($res);
}

class AppHide
{
   //控制器里的方法
    public function appHide($army): Response
    {
        ....
        return $army->res->withBody(Out::json(0, 'ok'));
    }
}

class A {
    public $b;
    public function __construct($b)
    {
        // $b是一个长周期的对象，比如$worker
        $this->b = $b;
    }
}

class A {
    public static $instance = [];
    public function __construct()
    {
        static::$instance[] = $this;
    }
}

$class = 'path\\classname';
if (!isset($instances[$class])) {
$instances[$class] = new $class; // 缓存类实例，避免重复初始化
}