function __construct(AsyncDNS $owner, Net_DNS_Packet $packet, $nextping = NULL)
{
parent::__construct($owner);
$this->packet = $packet;
if (!($sock = $this->connect(AsyncDNS::getNameservers()))) {
throw new Exception("Nameservers down");
}
if (!$sock->send($packet->data())) {
throw new Exception("Send error");
}
$sock->onRead(array($this, 'read'));
$sock->onError(array($this, 'error'));
$sock->onPing(array($this, 'ping'), $nextping);
$this->sock = $sock;
}
