[ros-users] ROS & DDS

Thu Feb 20 23:25:39 UTC 2014

In a theoretical ROS-on-DDS future, there would be a small C/C++
library that implements the familiar ROS API (pub, sub, adv, etc.)
atop the DDS API.  Assuming that Ada has a reasonable foreign function
interface, you could build your client library by wrapping that small
C/C++ library.

Or, as William suggested, you could implement the DDS wire protocol
(RTPS) directly in Ada.

There would also be some work to expose in-memory message objects to
Ada; here, again, you would likely have a couple of choices on how to
approach it.

brian.

On Thu, Feb 20, 2014 at 11:26 AM, William Woodall
<william at osrfoundation.org> wrote:
> For the theoretical system we are discussing here, that isn't entirely clear
> yet, but a large part of it would be looking at the DDS specifications:
>
> http://portals.omg.org/dds/content/page/specifications
>
> The DDS specifications separately define a wire protocol, a general API and
> behavior, as well as language specific API's (C/C++/Java), and the IDL
> message definition system, among other things.
>
> If you meant for the current ROS implementation, this wiki page is probably
> where you would start:
>
> http://wiki.ros.org/Implementing%20Client%20Libraries
>
> --
>
>
> On Thu, Feb 20, 2014 at 3:44 AM, Andrew Harris <andrew.unit at gmail.com>
> wrote:
>>
>> Hello,
>>
>>    Imagine a small company that would like to implement, for example, an
>> Ada client API for ROS.  What would this small company have to do in order
>> to find out how their new ROS Ada client API must behave?
>>
>> best regards,
>> -andrew
>>
>>
>> On Tue, Feb 18, 2014 at 8:43 PM, William Woodall
>> <william at osrfoundation.org> wrote:
>>>
>>> Sorry that entirely wrong, Michi Henning is chief scientist at ZeroC
>>> (which makes the Ice middleware). Martin Sústrik is the developer of ZeroMQ
>>> and nanomsg. Sorry about that :/.
>>>
>>> Still an interesting point.
>>>
>>>
>>> On Tue, Feb 18, 2014 at 5:40 PM, William Woodall
>>> <william at osrfoundation.org> wrote:
>>>>
>>>> This article was very good:
>>>>
>>>> https://queue.acm.org/detail.cfm?id=1142044
>>>>
>>>> I think that is outlines many of the fears that one might have with DDS,
>>>> culturally, but we should keep in mind that it is describing CORBA. Part of
>>>> me hopes that OMG learned from this with DDS and that the history of DDS is
>>>> different enough to avoid some of the mistakes CORBA made. It is definitely
>>>> something we will keep an eye on as we do market research and during our
>>>> prototyping.
>>>>
>>>> A very interesting point is that this article was written by Michi
>>>> Henning, the chief architect of ZeroMQ, who as since moved on to nanomsg.
>>>> Such a small world :)
>>>>
>>>>
>>>> On Sat, Feb 15, 2014 at 3:19 PM, Michael Zillich
>>>> <zillich at acin.tuwien.ac.at> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> my two cents regarding this discussion come from experiences with
>>>>> another "industry-standard" middleware, that was somewhat ... complex
>>>>> internally and thus typically was hidden under layers of convenience code:
>>>>> the abominable CORBA.
>>>>> (I ended up writing my own middleware after CORBA nearly killed a
>>>>> project)
>>>>>
>>>>> I have to admit I know nothing about DDS, so forgive me if I unjustly
>>>>> critizise it. But reading in some of the ongoing discussions that its
>>>>> complexity can easily be handled by some abstraction layer .. that rang an
>>>>> alarm bell.
>>>>>
>>>>> If something is too complex to use for the intended target audience of
>>>>> developers, and thus has to be hidden behind another layer (which, trust me,
>>>>> inevitably leads to the most hilarious bugs you can possibly imagine) then
>>>>> it is probably the wrong technology for that application area. (But there
>>>>> are certainly other appliction areas where this middleware is the perfect
>>>>> choice).
>>>>>
>>>>> So my personal choice is always a clear and simple solution targeted at
>>>>> a specific application area (with specific requirements, problems, and
>>>>> development procedures and cycles) rather than a
>>>>> solves-all-and-everyones-problems solution developled by large committees.
>>>>>
>>>>> cheers,
>>>>> Michael
>>>>>
>>>>> p.s. For those interested in the CORBA story read the enlightening
>>>>> article by Michi Henning
>>>>>   https://queue.acm.org/detail.cfm?id=1142044
>>>>> who as one of the authors of "Advanced CORBA Programming with C++" is
>>>>> probably one of the only two persons on the planet, who actually understood
>>>>> CORBA (the other person being Steve Vinoski, the other author of the book).
>>>>>
>>>>> --
>>>>> Dr. Michael Zillich
>>>>> ACIN Institute of Automation and Control
>>>>> Vienna University of Technology
>>>>> (DVR-Number 0005886)
>>>>> Gusshausstr 27-29/E376, 1040 Vienna, Austria
>>>>> zillich at acin.tuwien.ac.at       http://users.acin.tuwien.ac.at/mzillich
>>>>> Tel: +43 1 58801 376648           Fax: +43 1 58801 37698
>>>>>
>>>>> _______________________________________________
>>>>> ros-users mailing list
>>>>> ros-users at lists.ros.org
>>>>> http://lists.ros.org/mailman/listinfo/ros-users
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> William Woodall
>>>> ROS Development Team
>>>> william at osrfoundation.org
>>>> http://williamjwoodall.com/
>>>
>>>
>>>
>>>
>>> --
>>> William Woodall
>>> ROS Development Team
>>> william at osrfoundation.org
>>> http://williamjwoodall.com/
>>>
>>> _______________________________________________
>>> ros-users mailing list
>>> ros-users at lists.ros.org
>>> http://lists.ros.org/mailman/listinfo/ros-users
>>>
>>
>>
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>
>
>
> --
> William Woodall
> ROS Development Team
> william at osrfoundation.org
> http://williamjwoodall.com/
>
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