ZF2：pthreads - 传递PDO

This is my first time using pthreads.

I have a Controller that runs multiple threads. Each thread will do lots of processing, and it will wait for a file to download. Later, it will save to a database.

Previously in the controller I used to get an instance of the database connection using:

public function getAppTable() {
        if (!$this->appTable) {
            $sm = $this->getServiceLocator();
            $this->appTable = $sm->get('AppTable');
        }
        return $this->appTable;
    }

However if I try to do this in my Thread extending class, I'll get getServiceLocator is not defined due to the fact that the class does not extend Controller. I cannot pass $this->appTable to the Thread as PDO cannot be serialized or unserialized.

How can I get this to work?