Ada95 vs Eiffel ?

Ada95 vs Eiffel ?

[Luis Ibanez]

Hi,

I'm planning to develop a critical 
application related with real time
visualization of 3D medical data.

This application is intended to 
run in a surgery room.

The application could be run
on QNX or LYNX real time operating
systems (with an inocuous version
for windows NT...), and will 
intensively use calls to OpenGL.

I'm analyzing the alternatives of
good languages for this kind of 
tasks. By now, the finalist are
Ada and Eiffel,:


Eiffel :because its natural support
        of "design by contract".


Ada95  : because it has a long tradition
         in critical systems developments.


Can anybody give me some advices
about this choice ?



Thanks in advance.

PD. as a secondary point, 
which of this languages 
provides a more "secure" support
for graphical user interfaces ?
(like xforms, gtk, qt ...)

-- 
________________________________________________________________

Luis Eduardo IBANEZ

PhD Student
Departement Image et Traitement de l'Information
Ecole Nationale Superieure des Telecommunications de Bretagne
Technopole de Brest-Iroise BP 832,  29285 BREST - FRANCE
Tel (33)2.98.00.13.57      Fax (33)2.98.00.10.98
e-mail: luis.ibanez@ieee.org
home page: http://www-iti.enst-bretagne.fr/~ibanez
________________________________________________________________

Re: Ada95 vs Eiffel ?

[Tucker Taft]

Luis Ibanez (luisiban@club-internet.fr) wrote:

: I'm planning to develop a critical 
: application related with real time
: visualization of 3D medical data.

: This application is intended to 
: run in a surgery room.

: The application could be run
: on QNX or LYNX real time operating
: systems (with an inocuous version
: for windows NT...), and will 
: intensively use calls to OpenGL.

: I'm analyzing the alternatives of
: good languages for this kind of 
: tasks. By now, the finalist are
: Ada and Eiffel,:


: Eiffel :because its natural support
:         of "design by contract".


: Ada95  : because it has a long tradition
:          in critical systems developments.


: Can anybody give me some advices
: about this choice ?

Echoing what others have said, Ada is specifically designed for
real-time, safety-critical, embedded systems.  You can build
a significant Ada system with no dynamic allocation and 
little or no run-time support.  For what run-time support
you need, there are certified run-times available from multiple
Ada vendors, and you can write your own heap "storage-pool" manager
for any dynamic allocation you require.

By contrast, Eiffel depends fundamentally on dynamic allocation
and garbage collection.  That can be very nice in a desktop environment,
but can be troublesome in a resource-constrained, safety-critical,
real-time environment.

For what it is worth, there are also garbage collectors which can
be used with Ada when garbage collection is the preferred storage
management mechanism.

: Thanks in advance.

: PD. as a secondary point, 
: which of this languages 
: provides a more "secure" support
: for graphical user interfaces ?
: (like xforms, gtk, qt ...)

The "pragma Import" mechanism in Ada 95 is quite easy to use,
making it straightforward to access existing GUI subsystems.  Also,
there are some ready-to-go Ada interfaces for certain GUI
subsystems.  Consult one of the Ada vendors (see www.adaresource.org
for a partial list).

: -- 
: ________________________________________________________________

: Luis Eduardo IBANEZ

: PhD Student
: Departement Image et Traitement de l'Information
: Ecole Nationale Superieure des Telecommunications de Bretagne
: Technopole de Brest-Iroise BP 832,  29285 BREST - FRANCE
: Tel (33)2.98.00.13.57      Fax (33)2.98.00.10.98
: e-mail: luis.ibanez@ieee.org
: home page: http://www-iti.enst-bretagne.fr/~ibanez
: ________________________________________________________________

--
-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
Intermetrics, Inc.  Burlington, MA  USA
An AverStar Company

Re: Ada95 vs Eiffel ?

[Zane Lewkowicz]

Luis Ibanez  <luis.ibanez@ieee.org> wrote:
<snip>


Hello Luis!


I have no advice to give, because i don't have sufficient 
experience in either of these languages, but i would like to 
ask you to please announce what you learn and what you decide! 


Thank you,

Zane

"Must it be assumed that because we are engineers beauty is not
 our concern, and that while we make our constructions robust 
 and durable we do not also strive to make them elegant?"
                                              -- Gustave Eiffel

Re: Ada95 vs Eiffel ?

[LAMP-PUBLISHING]

Luis Ibanez <luisiban@club-internet.fr> wrote:
>Hi,
>
>I'm planning to develop a critical 
>application related with real time
>visualization of 3D medical data.
>
>This application is intended to 
>run in a surgery room.
>
>The application could be run
>on QNX or LYNX real time operating
>systems (with an inocuous version
>for windows NT...), and will 
>intensively use calls to OpenGL.
>
>I'm analyzing the alternatives of
>good languages for this kind of 
>tasks. By now, the finalist are
>Ada and Eiffel,:
>
>
>Eiffel :because its natural support
>        of "design by contract".
>
>
>Ada95  : because it has a long tradition
>         in critical systems developments.
>
>
>Can anybody give me some advices
>about this choice ?
>
>

We do life critical work too and our choice was limited by
what the government agenies would let us certify, in
our case ADA. If we attempted to use Eiffel we would
have to certify the entire Eiffel runtime.

steve

Re: Ada95 vs Eiffel ?

[Don Harrison]

Luis,

My recent background is realtime software engineering in Ada (8 years 
simulators and combat systems) although my "favourite" language is Eiffel.

:I'm planning to develop a critical 
:application related with real time
:visualization of 3D medical data.

...

:The application could be run
:on QNX or LYNX real time operating
:systems (with an inocuous version
:for windows NT...), and will 
:intensively use calls to OpenGL.
:
:I'm analyzing the alternatives of
:good languages for this kind of 
:tasks. By now, the finalist are
:Ada and Eiffel,:
:
:
:Eiffel :because its natural support
:        of "design by contract".
:
:
:Ada95  : because it has a long tradition
:         in critical systems developments.

I would say the strength of Ada is it's orientation towards realtime systems 
(slightly different).

:Can anybody give me some advices
:about this choice ?

Although I like Eiffel very much, I would choose Ada (but use it in an 
Eiffel-esque way), purely on pragmatic grounds. Ada is specifically geared 
towards realtime applications whereas no Eiffel vendor has supported the 
realtime domain with any credibility. Eiffel implementations lack the 
requisite support in terms of low-level and realtime libraries.

An external interface to C (basically what Eiffel offers) is no substitute 
for sophisticated, built-in low-level and realtime support.

:PD. as a secondary point, 
:which of this languages 
:provides a more "secure" support
:for graphical user interfaces ?
:(like xforms, gtk, qt ...)

Don't know the answer to that.


Don (Harrison).   donh at syd.csa.com.au
Eiffel - Software engineering with class

Re: Ada95 vs Eiffel ?

[Jean-Marc Jezequel]

> Luis Ibanez (luisiban@club-internet.fr) wrote:
> 
> : I'm planning to develop a critical
> : application related with real time
> : visualization of 3D medical data.
 ...
> : I'm analyzing the alternatives of
> : good languages for this kind of
> : tasks. By now, the finalist are
> : Ada and Eiffel,:

Nice shortlist ;-)


> : Can anybody give me some advices
> : about this choice ?

>Tucker Taft answered:
> Echoing what others have said, Ada is specifically designed for
> real-time, safety-critical, embedded systems.  You can build
 ...
> By contrast, Eiffel depends fundamentally on dynamic allocation
> and garbage collection.  That can be very nice in a desktop environment,
> but can be troublesome in a resource-constrained, safety-critical,
> real-time environment.
 
Yes, this is true, but it actually depends on what you call "real-time". 
For, let say, so called "hard real time", Ada is superior to Eiffel. But
a really tiny fraction of all information systems are really HRT. And
even in those, most often only a small part of the overall system is
HRT. Fore example, very few telecom (sub)systems are HRT: most often you
can afford to sligtly miss a deadline once in a while without
catastrophic consequences. For this kind of system, Eiffel is worth
considering for its clean and simple implementation of the OO paradigm
(see e.g., my paper: "Object-oriented design of real-time telecom
systems" -- In IEEE International Symposium on Object-oriented Real-time
distributed Computing, ISORC'98, Kyoto, Japan, April 1998.
http://www.irisa.fr/pampa/EPEE/isorc.pdf)

Good luck, and please tell us of your final choice.

-- 
Jean-Marc Jezequel               Tel : +33 299 847 192         
IRISA/CNRS                       Fax : +33 299 847 171         
Campus de Beaulieu               e-mail : jezequel@irisa.fr 
F-35042 RENNES (FRANCE)          http://www.irisa.fr/prive/jezequel