private function errorHandler($msg)
    {
        $waited = $this->getConfig('locktimeout');
        $this->log("PANIC! {$this->sid} cannot be acquired after waiting for {$waited}s. ");
        $h = $this->getConfig('error_handler');

        //call and exit
        call_user_func_array($h, array($msg));
        exit(1);
    }