[ros-users] ROS & DDS

Mon Feb 24 19:58:32 UTC 2014

I assume there would be a ROS IDL -> DDS conversion as part of this?  This could be useful for future extensions independent of the message transport.  Adding support for bitfields or range checking for example. 

-----Original Message-----
From: ros-users-bounces at lists.ros.org [mailto:ros-users-bounces at lists.ros.org] On Behalf Of Brian Gerkey
Sent: Thursday, February 20, 2014 6:26 PM
To: User discussions
Subject: Re: [ros-users] ROS & DDS

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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>
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