[ros-users] Nodelets

[Radu Bogdan Rusu]

Sounds great! Let us know if there's a particular feature you need that's missing atm. Also, if you build any cool 
extended functionality that you would like to share/contribute back, you know where we live ;)

Cheers,
Radu.

On 08/19/2010 10:29 PM, Daniel Stonier wrote:
>
> Mixing processes and platforms is exactly what we've been pushing
> towards for a while. We had good motivation in that direction - our CTO
> would get antsy and more than a little frustrated when the engineers
> rolled out long schedules everytime he considered porting to a new
> robot. So I had a robot core developing with a custom libplugin manager
> (much like the nodelet manager) and a 'topic' style multithreaded
> sigslots library for communications.
>
> The nodelets is nice though, the roslaunch features are great and it
> collapses our redundancy in the data structures back to the single ros
> msg style format as well as removing the need for the sigslots. I can't
> think of anything we'd really need, except perhaps an easy way to
> sometimes extend/customise our own nodelet managers - which I don't
> think would be too hard after having a look at the nodelets code.
>
> Cheers,
> Daniel.
>
> On 20 August 2010 12:02, Radu Bogdan Rusu <rusu at willowgarage.com
> <mailto:rusu at willowgarage.com>> wrote:
>
>     Daniel,
>
>     Nodelets are single process (usually multi-threaded), and you're
>     right - the publish/subscribe intra-process
>     optimization was implemented to get them to use the same ROS API
>     mechanisms (in addition to other requests). The nice
>     thing about the entire design is that you can easily split your
>     nodelet modules into different processes and on
>     different machines without changing anything in your code, simply by
>     passing them to different nodelet managers.
>
>     Cheers,
>     Radu.
>
>     On 08/19/2010 05:55 PM, Daniel Stonier wrote:
>      >
>      > Been playing around with nodelets and have a curiosity. I understand
>      > that their design was driven by the need to pass objects by handles
>      > (pointers) across messaging rather than full copies.
>      >
>      > Recently however, one of the willow garage guys (Josh maybe? I can't
>      > remember) pointed me to try some tests a little while ago with node
>      > handles. If carefully passing and publishing a boost pointer, then a
>      > subscriber in the same process will simply receive that pointer and
>      > bypass all the tcp/ip layers. Was this implemented recently as a
>     result
>      > of the work on nodelets? If not, are there any important differences
>      > between this and nodelets communication mechanisms?
>      >
>      > Actually, I still like the nodelets. Being able to drop your
>     libraries
>      > containing nodelets onto the nodelet manager via roslaunch file is
>      > awesome. You can put together an interrupt driven control system
>      > designed entirely from libraries and xml without the need to even
>      > program any binaries in most cases. Awesome.
>      >
>      > --
>      > Phone : +82-10-5400-3296 (010-5400-3296)
>      > Home: http://snorriheim.dnsdojo.com/
>      > Yujin Robot: http://www.yujinrobot.com/
>      > Embedded Control Libraries:
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>      >
>      >
>      >
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>     | Radu Bogdan Rusu | http://rbrusu.com/
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>
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> Yujin Robot: http://www.yujinrobot.com/
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-- 
| Radu Bogdan Rusu | http://rbrusu.com/