10 ms·
Does anyone know what it's written in? Boeing writes (nearly) everything in Ada and as far as I know has never had any software problems of this scale. Most of
by PeCaN 11y ago
Does anyone know what it's written in?
Boeing writes (nearly) everything in Ada and as far as I know has never had any software problems of this scale. Most of it is in SPARK as well, a restricted subset of Ada that can be partially formally verified[1]. Frankly, not formally verifying mission-critical software where a failure can potentially threaten someone's life seems rather irresponsible.
1. Contrary to what seems popular opinion, regular Ada is not particularly strict (less so than Rust). SPARK is very, very strict about what you can compile, and if it compiles it follows the spec (which is usually easier to audit).
- topkekz 11y agof-35 part starts at the bottom of page 37 https://www.csiac.org/wp-content/uploads/2016/02/2010_03_30_SoftwareQualityReliabilityandErrorPrediction.pdf https://www.csiac.org/wp-content/uploads/2016/02/2010_03_30_...
- nathancahill 11y agoFaulty car software threaten someone's life. Faulty fighter jet software threatens a lot more than that.
- mbrameld 11y agoYou're not wrong, you just missed the point.
- fsck--off 11y agoI think C++ but I'm not certain about that.
- deleted 11y ago[deleted]
- Jtsummers 11y agoC and C++ for the vast majority. Some Ada. Some Fortran, but probably only in physical modules (LRUs) that are being reused (COTS or GOTS) from other projects. http://www.militaryaerospace.com/articles/2013/10/software-code-f-35.html http://www.militaryaerospace.com/articles/2013/10/software-c... -- but a Google search reveals much the same from any article I can find, and just reiterates what I've read in past articles on F-35 software.
- xtrxtg 11y agoThe article seems to confuse ALIS with software that runs on the aircraft. ALIS is a web-based portal used by logistics and maintenance personnel to manage the logistics and maintenance for the F-35. As the article states: “ALIS is the ground-based computer system meant to diagnose mechanical problems, order and track replacement parts, and guide maintenance crews through repairs. It also allows pilots to plan missions and later review their performance.”
- Jtsummers 11y agoYeah, you're right. My comment is less appropriate as an answer to the question of ALIS's language.
- acomjean 11y agoSpeaking as someone who left a company that did radar software development in ADA (and some C). We were a subcontractor of Boeing and wrote the software for them. We didn't formally verify the code, its way too complex, but everything was reviewed and heavily tested. And tested again. Then integrated and tested... Ada is pretty strict and if it compiles you usually had some confidence it was going to at least run ok. The industry was moving to C/C++ because developers know it and promises of higher productivity. I did kinda grow to like ada. It had its warts, but it was good. It reminds me a bit of GO with its packages.
- PeCaN 11y ago> It reminds me a bit of GO with its packages. Ada Tasks also bear some semblance to goroutines. (In the sense that they share memory by communicating instead of communicating by sharing memory.) It's definitely a nice and well-designed language IMO—with a share of annoyances[1] and flaws—but overall deserving of more attention than it gets. Lately I've gotten comfortable enough with it that I have been making a habit of reaching for Ada for side-projects where I would formerly use C. (For example, I'm writing a toy X window manager in Ada at the moment—using XCB from Ada is a little ugly at times but definitely bearable.) 1. For example, why can't a record discriminant be a range bound? Answer: standards committee didn't think people would use it. Of course, this means if you have an array of discriminated size, you can't conveniently have a type for a position in it. e.g. type Thing_Stack (Max_Size : Positive) is record Elements : array (Positive range 1 .. Max_Size) of Thing; Top_Index : Positive range 0 .. Max_Size := 0; -- 0 = Empty stack end record; Fails to compile with "Discriminant cannot constrain scalar type". According to [2], this is because > This restriction is left over from Ada 83 (RM83 3.7.1(6)). We considered removing this restriction in Ada 95, but ultimately decided that the implementation effort to support this modest extension would outweigh the (more?) modest benefits. Perhaps a short-sighted decision, in retrospect... > As for why the original Ada 83 restriction existed, noone knows for sure, but it probably relates to the historical purpose of discriminants as only for controlling the "shape" of the record, rather than being seen (as in Ada 95) as more general type "parameters." And apparently it got left in Ada 2012 also. (For C people, this is basically: typedef struct { size_t max_size, top_index; thing elements[]; } thing_stack; but bounds-checked and without the annoyance of allocating flexible array members.) 2. http://computer-programming-forum.com/44-ada/82b646ab38d529af.htm http://computer-programming-forum.com/44-ada/82b646ab38d529a...
- outworlder 11y ago> Does anyone know what it's written in? The slightly sarcastic answer would be "C++, of course". There is even a code standars document that's floating around. (Edit) Link: http://www.stroustrup.com/JSF-AV-rules.pdf http://www.stroustrup.com/JSF-AV-rules.pdf That said, I don't really think the troubles come from the technology side of things.
- logicallee 11y agoI don't get why you state your response is slightly sarcastic. You mean "probably C++, even though it's not a suitable language"? Why not?
- engi_nerd 11y agoWell, to clarify, that's the coding standard for the Air Vehicle (in other words, the airplane itself). That does not apply to ALIS (although there's nothing stopping them from using those coding guidelines if they really wish, I guess). I have no idea what ALIS is written in.
- alephnil 11y agoSeems like most of it is written in C++, while some parts reused from F22 is in Ada 83. This was done "due to programmer availability" according to Wikipedia (links the article cite for that claim are dead).
- kps 11y agoLearning Ada is easier than learning to write reliable software. If language experience is the barrier to ‘programmer availability’, then management is Doing It Wrong.
- alephnil 11y agoIndeed. I included that quote precisely because it shows such a lack of perspective. To get programmers with experience in safety critical real time programming is much harder than learning Ada, and training them to learn safety critical programming is much harder than learning any relevant programming language. But apparently the availability of C++ programmers was what they considered important.
- tormeh 11y agoYou know, I think they need a language with a lower entry point, to make it easier to onboard developers. PHP should do the job nicely. Please nobody tell them.
- kps 11y agoSounds reasonable. An F-35 is built to ‘move fast and break things’.
- wrong_variable 11y agoSomeone should email the bosses the agile manifesto.
- kevin_thibedeau 11y ago
- bitwize 11y agoI would assume C++, since an oft-quoted set of C++ standards is linked to the JSF project.
- btbuildem 11y agoJavascript, by the sound of it..
- PeCaN 11y agoAt least the F-35 is web scale.
- supercoder 11y agoHopefully a modern JavaScript framework like Reduox, Isometa, or JSJ Query.