how can I implement efficient intra-process communication with message filters

asked 2019-06-10 04:00:27 -0500

xhuan28 gravatar image

I once tried out the tutorial of intra process communication which impressed me that it can improve communication performance with zero-copy. Afterwards, I tried to adopt this best practice in my application, but I met an issue. I need to synchronize messages from two topics with message filters. As mentioned in the tutorial, we have to use std::unique_ptrs to implement zero-copy.

This is because we’re publishing and subscribing with std::unique_ptrs which allow ownership of a message to be moved around the system safely. You can also publish and subscribe with const & and std::shared_ptr, but zero-copy will not occur in that case.

However, the callback of message filters only accept std::shared_ptr as its parameters. Does it mean we cannot take benefits from zero-copy if we use message filters, unless some code changes need to be done from message filter side?

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Comments

Cross posting your question in multiple locations (https://github.com/ros2/message_filte...) is against the etiquette: http://wiki.ros.org/Support#Etiquette

Dirk Thomas gravatar imageDirk Thomas ( 2019-06-10 11:24:46 -0500 )edit

Sorry, I didn't realize this is against the etiquette of ROS community. However, I think it is more suitable to ask this question here than the github of message filters, so I close that one in github. Could you please reopen this one? Thanks.

xhuan28 gravatar imagexhuan28 ( 2019-06-10 20:50:26 -0500 )edit

Actually, I would like to know whether it is a limitation to implement zero-copy with message filters currently and is it feasible to expose a new API from message filters to break the limitation.

xhuan28 gravatar imagexhuan28 ( 2019-06-10 20:59:08 -0500 )edit

I've re-opened this as the GH issue has been closed, but please keep the etiquette in mind @xhuan28.

I didn't realize this is against the etiquette of ROS community.

nt accepting cross-posting support requests is not necessarily something specific to the ROS community: it leads to split discussions and wasted effort on the part of the people responding to your questions. That would not be a good thing in any community.

gvdhoorn gravatar imagegvdhoorn ( 2019-06-11 02:20:21 -0500 )edit