[Xenomai-help] Hard real-time and C++

[Xenomai-help] Hard real-time and C++

[Rodrigo Rosenfeld Rosas]

Hi,

I'm willing to develop a framework for helping people to program mobile robots for doing hard
real-time tasks. Assuming most of them will have a limitated knowledge both to RTOS and
programming, I would like to keep it simple to use.

I think that developing it using a object-oriented methodology is crucial for achieving my
objectives. But I have some challenges then. And some questions too.

Since Xenomai and Linux will be built using gcc, I'm willing to use it too. So, I would need to
choose between C++ and C (through the Object Oriented C - OOC - approach). I didn't like very much
the OOC aproaches I've seen. I would like to understand better what would be the C++ problems
before I can choose between these alternatives.

I know about the new/delete problems that use the malloc like functions, that runs on secondary
mode. I was wondering if there is an elegant way of changing these call to some Xenomai memory
allocation functions. Maybe overriding new() methods... Any more suggestion?

Please, if someone could list me a list of disadvantages of C++ use on hard real-time systems,
requiring object oriented approach, I would be very glad to read it. Better yet if it comes with
the possible solutions to each problem or pointing out that there is no solution at all.

Thanks in advance,

Rodrigo.



	



	
		
_______________________________________________________ 
Yahoo! doce lar. Faça do Yahoo! sua homepage. 
http://br.yahoo.com/homepageset.html 

Re: [Xenomai-help] Hard real-time and C++

[Klaas Gadeyne]

> I'm willing to develop a framework for helping people to program mobile robots for doing hard
> real-time tasks. Assuming most of them will have a limitated knowledge both to RTOS and
> programming, I would like to keep it simple to use.

Do you know <http://www.orocos.org>?

> Please, if someone could list me a list of disadvantages of C++ use on hard real-time systems,
> requiring object oriented approach, I would be very glad to read it. Better yet if it comes with
> the possible solutions to each problem or pointing out that there is no solution at all.

<http://people.mech.kuleuven.be/~psoetens/orocos/doc/orocos-faq.html#id2451300>

ps.  There's experimental (i.e. untested) xenomai support in the latest
orocos release.

regards,

Klaas

Re: [Xenomai-help] Hard real-time and C++

[Rodrigo Rosenfeld Rosas]

Em Quinta 23 Mar=E7o 2006 04:55, Klaas Gadeyne escreveu:

>> I'm willing to develop a framework for helping people to program mobile
>> robots for doing hard real-time tasks. Assuming most of them will have a
>> limitated knowledge both to RTOS and programming, I would like to keep it
>> simple to use.
>
>Do you know <http://www.orocos.org>?

Yes, I didn't like the idea of using RT-CORBA. But I won't discuss this top=
ic=20
here neither. At least in the moment since I'm very worried about my=20
deadline...

>> Please, if someone could list me a list of disadvantages of C++ use on
>> hard real-time systems, requiring object oriented approach, I would be
>> very glad to read it. Better yet if it comes with the possible solutions
>> to each problem or pointing out that there is no solution at all.
>
><http://people.mech.kuleuven.be/~psoetens/orocos/doc/orocos-faq.html#id245=
1300>

Thank you very much, specially for the technical report. BTW, in section=20
4.2.2.2 (Dynamic Memory Allocation), what the IS-5.3.4 means? Where do I fi=
nd=20
it? And the other references too...

>ps.  There's experimental (i.e. untested) xenomai support in the latest
>orocos release.

How is dynamic memory management done in OROCO's classes? Do you override a=
ll=20
new() methods?

Thanks,

Best Regards,

Rodrigo.

		
_______________________________________________________ 
Novo Yahoo! Messenger com voz: Instale agora e faça ligações de graça. 
http://br.messenger.yahoo.com/

Re: [Xenomai-help] Hard real-time and C++

[Klaas Gadeyne]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed, Size: 1224 bytes --]

On Thu, 23 Mar 2006, Rodrigo Rosenfeld Rosas wrote:
> Em Quinta 23 Março 2006 04:55, Klaas Gadeyne escreveu:
[...]
>> Do you know <http://www.orocos.org>?
>
> Yes, I didn't like the idea of using RT-CORBA. But I won't discuss this topic
> here neither. At least in the moment since I'm very worried about my
> deadline...

<Off-topic>Orocos != RT-CORBA</Off-topic>

>>> Please, if someone could list me a list of disadvantages of C++ use on
>>> hard real-time systems, requiring object oriented approach, I would be
>>> very glad to read it. Better yet if it comes with the possible solutions
>>> to each problem or pointing out that there is no solution at all.
>>
>> <http://people.mech.kuleuven.be/~psoetens/orocos/doc/orocos-faq.html#id2451300>
>
> Thank you very much, specially for the technical report. BTW, in section
> 4.2.2.2 (Dynamic Memory Allocation), what the IS-5.3.4 means? Where do I find
> it? And the other references too...

It refers to the C++ standard I guess.  I doubt it's on the web though.

> How is dynamic memory management done in OROCO's classes? Do you override all
> new() methods?

Never.  Just don't allocate memory in the real-time parts of your
code.

Klaas

Re: [Xenomai-help] Hard real-time and C++

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 1073 bytes --]

Rodrigo Rosenfeld Rosas wrote:
> Hi,
> 
> I'm willing to develop a framework for helping people to program mobile robots for doing hard
> real-time tasks. Assuming most of them will have a limitated knowledge both to RTOS and
> programming, I would like to keep it simple to use.

Note that this is what our RACK (Robotic Application Construction Kit)
aims for. It comes with a simple modular concept for input, output, and
processing components, is written in C++ over Xenomai, contains a lot of
abstractions for typical component classes in mobile service robotics,
and supports both RT (=>RTnet) and non-RT (=>TCP/IP) distribution.

As my colleagues are currently porting a lot of old components from the
previous framework to RACK, there has been no time to finalise the
release of the core as open source. Well, we have no fixed schedule for
this release unfortunately, only schedules for two upcoming robotic
challenges within the next two months...

If you are interested in a sneak-preview, I could try to arrange
something next week.

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 250 bytes --]

Re: [Xenomai-help] Hard real-time and C++

[Rodrigo Rosenfeld Rosas]

Em Domingo 26 Mar=E7o 2006 07:03, Jan Kiszka escreveu:

>...
>Note that this is what our RACK (Robotic Application Construction Kit)
>aims for. It comes with a simple modular concept for input, output, and
>processing components, is written in C++ over Xenomai, contains a lot of
>abstractions for typical component classes in mobile service robotics,
>and supports both RT (=3D>RTnet) and non-RT (=3D>TCP/IP) distribution.
>
>As my colleagues are currently porting a lot of old components from the
>previous framework to RACK, there has been no time to finalise the
>release of the core as open source. Well, we have no fixed schedule for
>this release unfortunately, only schedules for two upcoming robotic
>challenges within the next two months...
>
>If you are interested in a sneak-preview, I could try to arrange
>something next week.

Yes, I would really like to see your design. I would be very glad if you co=
uld=20
be that kind. :)

Thank you,

Rodrigo.

		
_______________________________________________________ 
Novo Yahoo! Messenger com voz: Instale agora e faça ligações de graça. 
http://br.messenger.yahoo.com/