How can a node keep working while it waits for another one to publish on a topic?
I have a node (A) that works over a list of variables. This list should be updated regularly with the information given by another node (B). I can't rely on B working at a certain frequency and, as I don't want A to stop working in a ros::spin() (as B could take very long to publish something) I can't use the usual topic/callback. How could I implement this idea?