> Norman Vine wrote:
>
> Jonathan Polley writes:
> >
> >The biggest problem I see with C++ and the FAA is that it is VERY hard
to
> >guarantee that C++ will not do any dynamic memory allocation.
>
> Agreed --  this is the 'crux' of the issue for long running 'critical'
> software.
> AFAIK most of this kind of software when written in 'C' will only use
> statically defined 'space'.

The problem I see with Ada is manpower. In this area (near Johnson Space
Center) I saw some projects that were supposed to be done solely in Ada
erode the boundaries of what was acceptable to do in C simply because
"there just aren't any Ada programmers". In the mid-nineties I was one
member of a team of system administrators that supported the Space Station
Training Facility as it was being built up - that was done almost entirely
in Ada. People talked about Ada as if it was going to replace C for
general military/space use. That has gradually subsided here and now I
don't hear anyone talking about it. That certainly doesn't mean it isn't
being used here, but it leads me to wonder why this language has not taken
over the way people said it would.

I see C used in some important current projects locally:

- X-38 flight software
- X-38 avionics testbed simulation software (with legacy fortran code
included)
- Space Shuttle Engineering Simulator II, written in C.

I began writing JSBSim in C++ some years ago because it seemed to lend
itself well to the structure of flight dynamics modeling. I think it's
worked out well, and I can't imaging what it would look like if written in
C. Sure, we can get ourselves in trouble if not careful, but it seems to
work pretty well and it's been loads of fun.

Jon

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