UDPROS: Proper way to stop publishing after subscriber shutdown

edit

There seems to be no way implemented using UDPROS to notify the publisher of the shutdown / unsubscription of a topic (it's handled through closing the connection in TCPROS). No fitting XMLRPC function exisits as well, and no request is sent consequently. The master is notified of course, and the subscriber list updated there. Is there any other sensible way than polling the master for subscribers of a topic in the publisher?

This is the code I use for shutting down the subscriber, not that it should matter (and be necessary):

...
while(run)
    ros::spinOnce();
sub.shutdown();
node.shutdown();
ros::shutdown();