service add two ints client/service example test is flakey

[wjwwood]

See:

http://ci.ros2.org/view/nightly/job/nightly_osx_debug/29/testReport/projectroot.Users.osrf.jenkins.workspace.nightly_osx_debug.ws.src.ros2.examples/rclcpp_examples/test_example_add_two_ints_server_add_two_ints_client__rmw_fastrtps_cpp/

If you search through the console output, you'll see that it is failing due to the test timeout. I can reproduce this on my machine (it is flakey).

If I start the server and then run the client in a loop I cannot reproduce the issue. So I'm going to look into a startup race condition again, as I believe it is still this issue: #93 (comment)

I'm not sure I can solve it, but I am going to try some things and at least we'll have an issue tracking this (I couldn't find one that is already open other than ros2/rclcpp#201 which is tracking a related feature but not the issue). I think tracking the issue is a good idea because it took me a while to figure out we had already looked into this because I looked at the open tickets on this repository and didn't see anything.

[jacquelinekay]

have we observed this as flaky on fastrtps only or on multiple middlewares?

[wjwwood]

I believe more that one, but we couldn't implement the fix @gerkey originally wanted partly because the rmw layer for FastRTPS doesn't have topic listing (if I remember correctly).

[wjwwood]

This should hopefully be addressed by #110 (at least for opensplice) once it is merged.

[dirk-thomas]

Since the referenced PR which is supposed to address this has been merged has this been seen since then or can this be closed?

[wjwwood]

Yup.