Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Clearing all messages on a topic

callback

asked 2013-07-01 05:15:24 -0500

jnj11
61 ●1 ●2 ●7

updated 2013-11-14 12:32:55 -0500

tfoote

58457 ●128 ●550 ●526 http://www.ros.org/

I have been reading about the callback queue in roscpp but, I have not found the information I am looking for. I would like to know if there is a way to remove all messages in the callback queue.

As an example: I have a subscriberNode that subscribes to topicFoo and topicInterrupt

5 messages were published to topicFoo from publisherNode.

After the first topicFoo message is processed in topicFooCallback, a topicInterrupt message is published and processed. At this point, I would like all messages in the topicFooCallback to be removed.

Is there a way to do this? Please let me know if any of this is unclear.

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2013-07-01 11:44:49 -0500

thebyohazard
3542 ●52 ●68 ●83

Interesting question. I didn't see anything in the API that looked like it would do what you want. However, I would think re-initializing your subscriber would clear the queue. Maybe there's a better alternative we could help you figure out if you can tell us what you want to do.

edit flag offensive delete link

Comments

You can also simply momentarily set the callback to do nothing so that you can drain them very quickly until it's empty. It's not atomic, but you're downstream of an asyncronous link so that isn't any worse.

tfoote ( 2013-08-12 10:44:03 -0500 )edit

how about if you have a latched publisher that has already published a few messages and you want to cancel/delete those messages not to fall into any subscriber's callback?

azerila ( 2020-08-17 16:16:03 -0500 )edit

add a comment

Question Tools

2 followers

Stats

Asked: 2013-07-01 05:15:24 -0500

Seen: 5,728 times

Last updated: Jul 01 '13

Clearing all messages on a topic edit

1 Answer

Comments

Question Tools

Stats

Related questions

Clearing all messages on a topic