Ada holding up F-22 Raptor upgrades

http://www.defensenews.com/story.php?i=6559166&c=AME&s=AIR

by theclay • 15 years ago

27 37 15 years ago

defensenews.com

hsmyers• 15 years ago

OK, everyone here who codes in ADA, raise your hand. Atlas?

gooberdlx• 15 years ago

I was taught Ada95 by John McCormick, who wrote several textbooks on Ada.

Though I can't claim any professional experience, lots of my college education was straight from DoD/Navy expats who wrote military software.

There are lots of firms in the midwest that write this kind of software. John Deere, Lockheed, etc.

mithaler• 15 years ago

I hadn't known much about Ada other than that it's very old (as programming languages go) and it has a kind of nonspecific bad reputation, but I looked it up on Wikipedia and it actually doesn't look like an unpleasant language at all from the article. I particularly like its built-in message-passing system for concurrency: http://en.wikipedia.org/wiki/Ada_(programming_language)#Conc...

On projects like this I would worry more about accumulated technical debt from decades of modification than the language they're written in. (I suppose the language can complicate the task of hiring programmers who are skilled with its idiosyncrasies, but that's hardly an insurmountable or crippling problem.)

totalc• 15 years ago

From my defense software experience with Ada 83 and Ada 95, Ada's concurrency features made it much easier to work with than C. Tasks/processes were a top-level feature of the language, like classes in Java, and the "protected" keyword functioned somewhat like "synchronized" in Java (an implementation of the monitor pattern).

Our compiler package also came with an extensive concurrency API that offered a variety of threadsafe containers comparable (again) to java.concurrent - and this was software from the late 80s/early 90s!

What was bad about Ada was Ada 95. It strove to make Ada into an object-oriented language, but did a poor job of it with some very tortured syntax. edit what Masklinn said - "bolted on" is a perfect way to put it.

masklinn2• 15 years ago

There are many nice ideas in Ada, but I have two big issues with it:

1. It's a very lawyery language, there are very few things the compiler will accept to infer, which makes Ada tedious to read and write.

2. The strange mix of underscores and uppercases that is the normal Ada writing style (I believe Ada identifiers are case-insensitive, code from the 80s tends to be VERY_UPPERCASE_HEAVY while the same code now Tends_To_Be_Strangely_Capitalized) makes my head hurt.

And since this is avionics, they're probably dealing with embedded code (which tends to be even less readable) as well...

And as totalc notes, the OO additions of Ada 95 (if you have access to them) feel very bolted on and unnatural.

cubicle67• 15 years ago

when I went to Uni, the main language we used was Turbo Pascal (followed by loads of assembly and a small amount of C). The year behind us had Turbo Pascal replaced by Ada as that was going to be the Next Big Thing.

The Ada class started in '94 if a timeframe helps

gaius7• 15 years ago

Me!

Well not really, but Ada is alive and well in the guise of PL/SQL. You can see it if you look closely, type "desc sys.diana" into any Oracle DB, DIANA is "descriptive intermediate annotated notation for Ada".

illamint• 15 years ago

We had a project in our "Programming Languages" class that consisted of solving a problem in a number of different languages, including Ada, which proved to be the most difficult simply because of the lack of decent resources or guides online. I'm not saying I couldn't get accustomed to it, but with just about any other language you can go online and find a few guides that'll get you acquainted with the paradigm of a language, and I couldn't find anything like that for Ada. Programming in Prolog was easier because at least then I could go to our library and dust off a book from the late '80s about how to write programs in Prolog.

JulianMorrison2• 15 years ago

I've played with it, it's a nice language. Don't see why people hate on it, it's not especially verbose, and the static types are actually helpful (like, you can cleanly loop over the extent of an enumerated type, for example) as well as more than usually protective (like, you can type define "inches" and "centimeters" as kinds of integer, and it won't let you mix them by accident).

gaius7• 15 years ago

F# has units of measure too.

thesz• 15 years ago

Does VHDL count?

doctorosdeck• 15 years ago

I write real-time avionics software for my day job. It's done almost entierly in Ada95.....I don't work on the F-22's.

theclay• 15 years ago

So then what's your take on coding in Ada compared to other languages?

jameskilton• 15 years ago

Odd story, makes software development in Ada kind of a catch-22. The DoD has used Ada for so long because of the security and correctness constraints built right into the language and compiler. When you're talking about software that's flying a plane (passenger, war time, whatever) it HAS to be right, because if it's wrong, people die. When something HAS to be right, that by itself ensures longer development time and testing.

Now I'm not in this industry, but I know that planes these days are extremely complicated beasts and require a ton of code to run everything properly. I worry that if development is artificially sped up, that code problems that would have been caught in the testing get caught in production.

Of course the above kind of assumes a decent dev team and a good code base. What I said could be moot if what's really happening is the technical debt of some of this code is so massive that simple changes take months to make and ensure correct, which would be a problem for sure.

Either way, blaming the language probably isn't the right way to go about this.

nradov• 15 years ago

I have no idea about their overall code quality but there was a famous F-22 bug found a few years ago where it lost all navigation systems when crossing the international date line.

http://www.defenseindustrydaily.com/f22-squadron-shot-down-b...

stcredzero• 15 years ago

Date/Time code is notorious. It always seems simpler than it actually is. There are always corner cases you forgot about. None of it is rocket science. Instead, it's the stupid arbitrariness of it that gets you. (Commodity trading is often the same.)

bugsy• 15 years ago

But I want the lolly NOW!!!!

But seriously, Ada is well designed and not difficult. Ada is not part of the problem, this would take longer and be less reliable in C++.

gaius7• 15 years ago

The article actually nails the real reason: the USAF bought far fewer F22s than it originally planned, so things like this that apply equally to 1 or 1000 have to have their cost spread over far fewer individual units. I'll bet that the F22 software is not actually that much more complicated than that controlling a modern car, yet Ford or whoever can spread the cost over a million units.

masklinn2• 15 years ago

> I'll bet that the F22 software is not actually that much more complicated than that controlling a modern car, yet Ford or whoever can spread the cost over a million units.

I'll bet it is. A car is significantly simpler than a fighter plane (at all levels of resolution), even when you discount weapons and detection systems. Which you can't discount when you're building software for a plane.

Furthermore, the risks involved in a fly-by-wire avionics soft are much greater than in cars in case of bug or crash: there are no drive-by-wire production cars today, although there are many electronics systems.

seanwoods• 15 years ago

What's used in place of Ada nowadays?

gaius7• 15 years ago

OCaml would be a great fit for this space, so would Haskell or Scala...

sbalea• 15 years ago

Oh hellz no! Most of the systems ADA is used for tend to be realtime stuff. The moment you utter the words "Garbage Collection" you throw your realtime guarantees down the toilet.

spatulon• 15 years ago

The Joint Strike Fighter software is written in C++. Meanwhile, the EuroFighter project is still using Ada.

ikilledkojack• 15 years ago

C and C++. Ada is used less for new projects, but existing projects aren't switched over - many projects have long lifespans going over a decade or more.

jerrya• 15 years ago

C++

Ada holding up F-22 Raptor upgrades

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