ros2 topic pub starts publishing right away.

[fujitatomoya]

address #624

Signed-off-by: Tomoya Fujita Tomoya.Fujita@sony.com

[fujitatomoya]

@clalancette @ivanpauno what do you think? i'd like to hear your opinion.

[clalancette]

I think we should punt on this for now; the issue isn't that important and I don't think we should change it for Galactic. I'll add this to H-Turtle board instead.

[audrow]

The change looks good and I tested that it worked on my machine.

I think maybe the true solution is to change the timer behavior in rcl, but this might be an easier way to make ros2 topic pub perform how the user expects.

[audrow]

• Linux
• Linux-aarch64
• macOS
• Windows

[ivanpauno]

I think maybe the true solution is to change the timer behavior in rcl

I don't think that's a good idea.
e.g.: if you want a "one-shot timer", what you currently do is to register a timer and cancel it from the callback.
If the first call happens immediatly that wouldn't work.

[fujitatomoya]

e.g.: if you want a "one-shot timer", what you currently do is to register a timer and cancel it from the callback.

yeah i am with @ivanpauno on this. application can have more control for use cases.

[audrow]

Rerunning CI to double check that things are good:

• Linux
• Linux-aarch64
• macOS
• Windows

[fujitatomoya]

I believe that rebase required to include #616, retry CI:

• Linux
• Linux-aarch64
• macOS
• Windows

[ivanpauno]

@ros-pull-request-builder retest this please

[ivanpauno]

@fujitatomoya could you confirm if the Rpr failure is unrelated or not?

Besides that failure, this seems to be ready to be merged.

[fujitatomoya]

@ivanpauno thanks!

https://build.ros2.org/job/Rpr__ros2cli__ubuntu_focal_amd64/223/testReport/ros2topic.ros2topic.test/test_cli/test_cli/ is not related to the fix. it is failure of ros2 topic info not pub, i do not see the relationship from the test implementation. besides, i cannot reproduce this failure on my local environment.

(Just FYI, https://build.ros2.org/job/Rpr__ros2cli__ubuntu_focal_amd64/223/testReport/ros2topic.ros2topic.test/test_cli/test_cli/ does have the expected output which is Type: std_msgs/msg/String\n\nPublisher count: 1\n\nNode name: talker_node\nNode namespace: /\nTopic type: std_msgs/ms...ds\n Liveliness: AUTOMATIC\n Liveliness lease duration: 9223372036854775807 nanoseconds\n\nSubscription count: 0\n\n. i do not really see why this is failing.)

[ivanpauno]

Ah, I know the problem

Liveliness lease duration: 9223372036854775807

ros2/rclpy#722, that change wasn't released into rolling when the Rpr builder last run (and the tests here were already updated).

It should pass now:

@ros-pull-request-builder retest this please.

[fujitatomoya]

@ivanpauno thanks for the support!