php class Singleton of thread type

I have a class that accesses the service layer of my application. This class is a singleton. Through the service, it accesses the data evenly, so that my application has the expected behavior. The problem is, I see the need for my class to also be a thread. Does that make sense to you? Thanks

class envio_massa extends Thread {
// atributos
private static $instance = NULL;


// construtor
private static function __construct() {
    ;
}

// funções

// singleton
public static function get_instance() {
    // Já existe uma instância
    if (self::$instance == NULL) {
        self::$instance = new envio_campanha_service();
    }

    return self::$instance;
}

// Previne o uso de clone
private function __clone() {}
public function run() {...}

}