events.php中onMessage和onClose如何使用同个数据库操作类或全局变量呢？

$DataBaseConn=null;
$gateway_text->onWorkerStart = function($connection)
{   
    global $DataBaseConn;
    $DataBaseConn="test";
}

public static function onMessage($client_id, $message){
     global $DataBaseConn;
     echo $DataBaseConn;
}

$businessworker->onWorkerStart = function($connection)
{
    global $DataBaseConn;
    $DataBaseConn="test";
}