move qos_profile_rosout_default from rcl.

[fujitatomoya]

related and need to be merged before ros2/rclpy#1376

[fujitatomoya]

qos profile for rosout publisher is defined in rcl. it should be moved here with other profiles. see more details for ros2/rcl#1195

[fujitatomoya]

Pulls: ros2/rclpy#1376, #381, ros2/rcl#1195, ros2/rclcpp#2663
Gist: https://gist.githubusercontent.com/fujitatomoya/e4ad476b64d3f274940ae31ebe7149e3/raw/2fa0833cd5e3edd9602385b88d556cb0d18ad054/ros2.repos
BUILD args: --packages-above-and-dependencies rclpy rmw rcl rclcpp
TEST args: --packages-above rclpy rmw rcl rclcpp
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/14837

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[christophebedard]

I think we talked about this in the waffle meeting last week and it was mentioned that, since rosout is an rcl-level thing and not an rmw-level thing, the QoS profile should stay in rcl.

[fujitatomoya]

@christophebedard thanks for the comment!

hmmm okay, in that case why clients default profiles are defined in rmw? for example, rmw_qos_profile_parameter_events. if those are supposed to be defined on where it is used, it should be defined in client libraries? i was thinking that those default profiles are defined in rmw so that all dependent libraries on top of that, can be consistent profile... maybe i am missing something... ❓❓❓

[christophebedard]

Then maybe rmw_qos_profile_parameter_events doesn't belong in rmw. If it's meant to be used by client libraries (rclcpp, rclpy) and not rmw itself, and is a client library concept instead of an rmw concept, then it should go in rcl.

Parameter events are a client library concept, but clients and services are an rmw concept, so rmw_qos_profile_services_default probably belongs in rmw. So I wouldn't say "defined where used" but "defined where it belongs," if that makes sense.

Anyway, I was just relaying what was mentioned in the waffle meeting last week. We may want to talk about it again.

[fujitatomoya]

yeah i know you are just sharing the information, thanks!

since rosout is an rcl-level thing and not an rmw-level thing, the QoS profile should stay in rcl.

if that is a really requirement, we need to update the pybind to expose the rosout qos from rcl instead of rmw.

IMO, having rosout default profile in rmw should be okay, lets keep this open.

[fujitatomoya]

@ahcorde @clalancette @mjcarroll @wjwwood any thoughts above discussion? thanks in advance.