课堂上的功能不承认mysqli对象

Question

我的PHP Thread类有问题，虽然我在构造函数的$this->mysqli上指出$mysqli变量我在该类的函数中得到NULL该变量。

class Process extends Thread {

    protected $counter;
    protected $mysqli;

    public function __construct($name, Counter $counter, $mysqli )
    {
        var_dump($mysqli); // here connection exist

        $this->name = $name;
        $this->counter = $counter;
        $this->mysqli = $mysqli;

    }

    public function run() { 

        var_dump($this->mysqli); // here connection doesn't exist (empty mysqli object)

        $address = new Link($this->mysqli, $this->name);
        $address->insertName($this->name);

    }
}