QoS Issues with rmw_connextdds

[cwecht]

If I use EventsExecutors with rmw_connextdds and these chagnes (ros2/rmw_connextdds#76), which enable event listeners, I get many warnings regarding incompatibly QoS. For example, if I execute the events execturos tests, I get these warnings for each test case:

I have no idea whether this is an issue of the events executor or these changes to rmw_connextdds. But I suppose that it makes sense if both sides would have a look at this issue.

[mauropasse]

I think this is the same issue we had both on rmw_cyclonedds and rmw_fastdds, that we were storing a single "event callback" for all the possible listener callbacks. So first a callback is set for "new message" events, but then it is overridden with the callback for an "incompatible QoS". Thus, when you get a new message, the callback for "incompatible QoS" is wrongly called.
This is happening on rmw_connextdds, see here.
Connext should have an array of callbacks for each listener event type (new message, new QoS event, etc).
See what rmw_fastdds has:

https://github.com/ros2/rmw_fastrtps/blob/926b3a1472fc5ba74972ca8384b054c94571b27c/rmw_fastrtps_shared_cpp/src/custom_subscriber_info.cpp#L278

And rmw_cyclonedds:

https://github.com/ros2/rmw_cyclonedds/blob/76572ebf1032f359ed302d7017471a295738fa1e/rmw_cyclonedds_cpp/src/rmw_node.cpp#L641

[cwecht]

@mauropasse Thank you very much for the quick response! I was able to adapt rmw_connextdds acordingly.