Re: [ros-users] Shared memory image plugin

Do you have any timing data of this vs. TCP over loopback? Since you're
still doing a serialize/deserialize I would expect them to be fairly
similar.

Josh

On Thu, May 6, 2010 at 5:05 PM, Cedric Pradalier <
cedric.pradalier@mavt.ethz.ch> wrote:

> Hi All,
>
> I've just written a small shared-memory based image_transport_plugin using
> boost::interprocess and it raises 2 questions:
>
> - First, I don't see how to write it efficiently while having the publish
> function const in image_transport/publisher.h. I currently wait to receive
> the first image to allocate the shared memory segment, and as far as I could
> tell, I can only do it in the publish function of the plugin, so this has to
> be non-const. Any reason why it would have to be const? Or any hint on how
> to achieve the same result while having the function const?
>
> - Second, as it is written now, the plugin does not care at all that the
> object it manipulates are images (it cares that the object are
> constant/bounded size though). So would it be possible to extend/convert the
> image_transport plugin architecture, to a generic message_transport plugin
> architecture? I think sharedmem transfer would be particularly suitable for
> big point clouds...
>
> I attach the targz of the package if someone wants to review it. It will
> NOT compile in a standard install, because of the "const" problem mentioned
> above. I include a patch to image_transport that removes the "const". Note
> that if you apply it, you also need to check the const in the other
> image_transport_plugins (2nd patch).
>
> Best,
>
> --
> Dr. Cedric Pradalier
> http://www.asl.ethz.ch/people/cedricp
>
>
> _______________________________________________
> ros-users mailing list
> ros-users@code.ros.org
> https://code.ros.org/mailman/listinfo/ros-users
>
>