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Hello people,
I wanna know what are the advantages and the disadvantages regardless to CPU usage / Memory between using the Dynamic reconfigure tool to simply use the rosparam::get function inside my loop.
Thanks, Aviad
To add to what @gvdhoorn said, ros::param::get() is generally intended for retrieving a parameter that doesn't often (if ever) change, but dynamic_reconfigure is intended to keep dependent nodes updated when a parameter may change more often. The first method is often used when initializing a node that depends on some runtime constants. The second is better suited to (re)configuring a driver node or tuning navigation parameters for example. Going further, if your parameter changes very frequently, a topic or other mechanism may be better than either of the previous two methods.
You said dependant nodes but I have hardly seen any examples that configure params between the nodes (or used by several nodes and notify them). Isn't dynamic_reconfigure intended to configure a single node?
Thanks! The client's role and rqt_reconfigure being a client should be better emphasized in the documentation, I think
Asked: 2021-03-01 11:32:46 -0500
Seen: 549 times
Last updated: Mar 01 '21
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I don't believe
dynamic_reconfigurewas created to deal with resource utilisation issues.dynamic_reconfigureis an asynchronous callback based system, in which your nodes are notified parameters have changed.ros::param::get(..)needs to be called by your code, periodically. There is no way for it to be notified of anything, so your node will be unaware anything has changed, unless it explicitly callsros::param::get(..).This is a fundamentally different control flow, and that's the big difference between the two.
Edit: repeatedly calling
ros::param::get(..)is actually an anti-pattern (as there is a rather significant overhead incurred when retrieving parameters) and should be avoided.From that perspective there is a difference in resource utilisation, but it would depend on how the developer has structured his node.