private void Start()
{
if (client.Handle == IntPtr.Zero || handle != IntPtr.Zero ||
(foundListeners.Count == 0 && timeoutListeners.Count == 0))
return;
lock (client) {
handle = avahi_host_name_resolver_new (client.Handle, iface, proto,
Utility.StringToBytes (hostname), aproto, flags,
cb, IntPtr.Zero);
if (handle == IntPtr.Zero)
client.ThrowError ();
}
}