hi,
Why the object-oriented design is not suitable for real time system?

Any hints? Thank you

Homework???

What is the context of your question?
What kind of real-time system?

Not a homework its just something I need to discuss in the next lecture. I mean real-time systems in general, ex: anti-burglar system. My question is why the object oriented languages are not better choice for implementing such systems since for the time constraint is important. I'm not very familiar with this thats why I ask, but I have some basic ideas, all I need is a little nudge

Discuss in the lecture??? Are you the teacher? (If you are a student, then preparing for a class discussion IS homework.)

What is your background in programming? Have you ever programmed a real-time system?

I am not well-versed in object-oriented programming, but I can't think why it would make a difference. Isn't the main issue knowing how long different processes will take and/or having the time be consistent?

A real-time system is one where software, and its associated control system, has to respond to a real-world situation where 'time' is critical in the proper sense of the word. One example is where a tool in a machine-tool system (operating at full speed) is cutting a circle which has to be accurate to one-tenth of a thousandth of an inch. I've done that. Realise that not only the tool but the electronics, and the drive systems in the machine tool, have to respond to software which, itself, is highly complex. In fact, any system such as aircraft and the like, have the tiniest margin of error, else it is disaster. I suggest that a burglar system is not in that category!

I should have added in my previous post that, in my view, object oriented (OO) programming is entirely suitable for a burglar alarm system because the time constraints are not as critical as in fast real-time control software/electronic systems. The objects in OO programs are generalised but seldom for speed. I suppose one could have real-time objects, but I would prefer to write real-time software in assembler, or possibly C, even C++ with care, Ada, and I used Pascal many years ago.

There is no reason OO languages can not be used in a real-time context.

Most real-time applications are done in C, with assembly optimizations, but it could also be done in C++, or even Java. The important thing in real-time operating systems is the ability to determine how long something will take - not necessarily raw speed. As long as the language has a good compiler, and allows the programmer to determine how long each task will take, it can be used for a real-time application.

Having said that, C is generally used because it allows for optimizations, and can be very predictable. Also, most of the benefits of OO would not be required in a real-time environment.

If you need to prepare for a lecture, read the relevant chapters of your text, other texts and resources available on the internet (Like IEEE Xplore).

--Ian