Re: [ros-users] Shared memory image plugin

Top Page
Attachments:
Message as email
+ (text/plain)
+ (text/html)
Delete this message
Reply to this message
Author: Josh Faust
Date:  
To: ros-users
Subject: Re: [ros-users] Shared memory image plugin
>
> Using serialise/deserialise is I think the only way to do it without
> specialising to one object type. I don't think these functions have a
> huge cost with boost implementation, but I'd be curious to hear about
> any experience out there.
>
>

serialize/deserialize are a very significant portion of sending large
images, especially over loopback (vague recollection of about 2/3rds of the
time from some timings I did while optimizing intraprocess passing, but that
may not be quite right). Most of serializing/deserializing an Image is
memcpy, but that still takes time.

We've talked about a system that allocates the messages themselves out of
shared memory, but that's a huge can of worms. Nodelets (currently in the
common 1.1 experimental releases) are the preferred path forward at this
point.

Josh