Add resource enforcing to conman_ros

[jbohren]

Add an option to the actionlib actions so that they can be long-running. In this way, they will claim "ownership" of a set of blocks until the action is cancelled. Enforce this in the conman_ros action server.

[adolfo-rt]

Would this mechanism allow to encode behaviors such as exclusivity or allowing concurrence depending on conditions?. Example: Disallow write access to a position command from two sources, but allow multiple writers to an effort command.

[konradb3]

I think that is possible. As it's configured on per port basis. Your example is already possible using only exclusivity mechanism. We can configure "position command" input port to be exclusive and "effort command" input port to be not exclusive.

The idea is to provide mechanism that ensure that there is at leas one component writing data to port. For example we want to ensure that when position controller is active there is also at least one component providing commanded position active.

[adolfo-rt]

The idea is to provide mechanism that ensure that there is at leas one component writing data to port.

Yes, and also that there are not too many, where applicable.