no ros::spinOnce()

[simonschmeisser]

calling ros::spinOnce() in random places ( ;) ) messes up threading. This causes updates to PlanningSceneMonitor and joint state to be handled in our gui thread as opposed to the async spinner thread where we intended them to be handled.

[davetcoleman]

This may have big consequences to current users - can you please create a MIGRATION.md file for Melodic and include a note about this change?

See https://github.com/ros-planning/moveit/blob/kinetic-devel/MIGRATION.md for reference

[simonschmeisser]

I'll be on vacation for two more weeks but thanks for looking at all the stuff Dave!

I can see only one case where this would negatively affect existing code: when you never ever call spinOnce and don't start any async spinner thread. I would consider this a bug in user code. Do I miss anything? For us this was just a huge bugfix as spinOnce processes the entire content of the message queue in the calling thread. This heavily delayed JointState messages in some cases.

I'll write the migration note when I'm back

[simonschmeisser]

@davetcoleman like this?

[davetcoleman]

Awesome thanks!

[simonschmeisser]

I'd love to see this cherry picked to kinetic-devel as well ...