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Why is BIND 10 written in C++ and Python?

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Re: Why is BIND 10 written in C++ and Python?

#71

Post by nicholassmith »

papsosouid wrote: post #54
nicholassmith wrote: post #13

I think it's interesting that they did consider C and then decided it was too much of a risk. There's a constant theme of 'why use C++? C is faster and doesn't suck as much!' especially due to Linus' statements on the language, but often C is a technical risk as there's so much more that can go wrong. I'm not saying C++ is a better language than C, but it's definitely different and given the language is structured to…

>but often C is a technical risk as there's so much more that can go wrong. That is objectively incorrect. There is much less that can go wrong with C, as there is much less period. Everything that you can do incorrectly with C, you can do incorrectly with C++, plus 10 times more things that C++ introduced. The idea that C++ is safer because "we just won't do dangerous stuff" is silly, as any language is safe if you…

Alright, I probably phrased it wrong. C++ was written with specific safe guards against a number of common issues than can occur in C code, still it's more than possible to go horrifyingly wrong in C++ but the language has been designed (well, 'ish', it's still C++) to help avoid simple issues. The issues then come from the fact it's still is a fairly complex language and developers are often going to make mistakes.

All languages are safe if you've written perfect code, but no one is perfect, C++ does try to catch some of the lower hanging fruit problems but if you're writing hoary code you're going to blow your foot off eventually.

Re: Why is BIND 10 written in C++ and Python?

#72

Post by pjmlp »

papsosouid wrote: post #54
nicholassmith wrote: post #13

I think it's interesting that they did consider C and then decided it was too much of a risk. There's a constant theme of 'why use C++? C is faster and doesn't suck as much!' especially due to Linus' statements on the language, but often C is a technical risk as there's so much more that can go wrong. I'm not saying C++ is a better language than C, but it's definitely different and given the language is structured to…

>but often C is a technical risk as there's so much more that can go wrong. That is objectively incorrect. There is much less that can go wrong with C, as there is much less period. Everything that you can do incorrectly with C, you can do incorrectly with C++, plus 10 times more things that C++ introduced. The idea that C++ is safer because "we just won't do dangerous stuff" is silly, as any language is safe if you…

C++ allows to you to

- use safe arrays with bound checking if you feel like to

- use automatic memory management

- pass arguments by reference and being sure they point to valid data

- use proper strings without caring if the null character is missing

C++ is only dangerous thanks to the C compatibility legacy.

Don't use C'isms and the application will be a lot safer than doing pure C coding.

Re: Why is BIND 10 written in C++ and Python?

#73

Post by qznc »

justin66 wrote: post #47
nicholassmith wrote: post #13

I think it's interesting that they did consider C and then decided it was too much of a risk. There's a constant theme of 'why use C++? C is faster and doesn't suck as much!' especially due to Linus' statements on the language, but often C is a technical risk as there's so much more that can go wrong. I'm not saying C++ is a better language than C, but it's definitely different and given the language is structured to…

It's a tangent, but: has Linus ever given a presentation that involved actually discussing code? Perhaps code projected on a screen, even part of a slideshow? It's odd that he's such an accomplished engineer but every presentation I've seen him give involves saying outrageous things while starry-eyed geeks stare at him adoringly. If it weren't for the fact that he's arguing from a position of (very great) authority,…

Linus does not code much these days, at least not in the kernel. Writing emails and git-merging is most of his job.

If Linus is coding, it is probably more on his scuba diving tool than the Linux kernel.

https://github.com/torvalds/subsurface

Re: Why is BIND 10 written in C++ and Python?

#74

Post by przemoc »

For core services like BIND I don't see any good reason to write them in more than one language (actually anything other than C/C++) and introduce cumbersome dependencies because of that. I wouldn't complain if it was some another DIY name server toy created for whatever reason (how much time it would take..., I can do it!, etc.), but it's software that will become widely deployed in upcoming years (almost) without doubt.

How much more work these 17% done in Python would take to be (re)written in C++? Would it make the code that much worse in terms of quality and managability? Having coherent, one-language codebase, is a good feature on its own too, often improving above mentioned factors.

Re: Why is BIND 10 written in C++ and Python?

#75

Post by pjmlp »

army wrote: post #59
pjmlp wrote: post #8

Nice to see more projects moving into more expressive and safer languages.

I'm not sure that I'd call dynamic languages like Python safer, it depends on context. Compared to C/C++ you lose static typechecking but gain a safer memory model.

Anything is better than C.

Re: Why is BIND 10 written in C++ and Python?

#76

Post by pjmlp »

buster wrote: post #62
microtonal wrote: post #33

Earlier quoted context omitted.

Probably because of memory usage and garbage collection and the fact that java needs to be installed on most systems whereas C++ needs no dependencies Well, GCC (as in the compiler collection) has had a ahead-of-time compiler for ages: http://gcc.gnu.org/java/ There is also work in the LLVM camp on AOT Java compilation: http://vmkit.llvm.org/ Atleast i wouldn't sleep well if i know that the heart of the internet was…

Which ones? I'd say DNS is probably the most important parts. I also don't believe that core routing equipment is running in the JVM. Apparently you are talking about the "Web", i was talking about the internet or networks in general.. I'm aware that tomcat may have a very large installation base. There is no use for your tomcat if the DNS is down, though :P

What about missile radar systems?

http://www.militaryaerospace.com/articles/2009/03/thales-cho...

Re: Why is BIND 10 written in C++ and Python?

#77

Post by pjmlp »

fdr_cs wrote: post #36
microtonal wrote: post #33

Earlier quoted context omitted.

Probably because of memory usage and garbage collection and the fact that java needs to be installed on most systems whereas C++ needs no dependencies Well, GCC (as in the compiler collection) has had a ahead-of-time compiler for ages: http://gcc.gnu.org/java/ There is also work in the LLVM camp on AOT Java compilation: http://vmkit.llvm.org/ Atleast i wouldn't sleep well if i know that the heart of the internet was…

Those implementations have quite weak garbage collection implementations (boehm conservative, but I'm not sure), which would just kill the performance. Hotspot JVM has a very sofisticated Incremental Generational garbage collector, which does have a _very_ good performance. I'm pretty sure they had their reasons for not using Java (I actually do have mine too), but, garbage collection is not one of those.

There are many more commercial AOT solutions for Java

- IBM J9

- Aonix PERC

- Oracle Squawk VM

- Oracle Embedded Java

- Excelsior JET

- Avian

- RoboVM

- ...

Re: Why is BIND 10 written in C++ and Python?

#78

Post by mattmanser »

przemoc wrote: post #74

For core services like BIND I don't see any good reason to write them in more than one language (actually anything other than C/C++) and introduce cumbersome dependencies because of that. I wouldn't complain if it was some another DIY name server toy created for whatever reason (how much time it would take..., I can do it!, etc.), but it's software that will become widely deployed in upcoming years (almost) without d…

You can look at the source yourself.

I don't understand either, randomly opening parts of both the Python and C++ and it's certainly not complicated and they write the Python in a C style anyway.

I'm not a C++ coder and I only play with Python now and then, but can't say the code impressed me much. It's actually pretty hard to skim the code because it's massively over-commented and there are far too many tiny 2-line private functions that are called by exactly one other 2-line private function that is called by exactly one other 2-line function. Or Holographic code as John D. Cook called it[1].

And the copyright notice in every source file is extremely irritating.

Far too high noise to code ratio for my tastes, so I got bored before I could really 'see' how the Python had helped.

but I can't judge that well as I'm not sure if that's all just a bi-product of using C++ and being an open source project that comes out of committee.

[1] http://www.johndcook.com/blog/2012/01/09/holographic-source-...

Re: Why is BIND 10 written in C++ and Python?

#79

Post by papsosouid »

pjmlp wrote: post #72
papsosouid wrote: post #54

Earlier quoted context omitted.

>but often C is a technical risk as there's so much more that can go wrong. That is objectively incorrect. There is much less that can go wrong with C, as there is much less period. Everything that you can do incorrectly with C, you can do incorrectly with C++, plus 10 times more things that C++ introduced. The idea that C++ is safer because "we just won't do dangerous stuff" is silly, as any language is safe if you…

C++ allows to you to - use safe arrays with bound checking if you feel like to - use automatic memory management - pass arguments by reference and being sure they point to valid data - use proper strings without caring if the null character is missing C++ is only dangerous thanks to the C compatibility legacy. Don't use C'isms and the application will be a lot safer than doing pure C coding.

C allows those things too, that's the point. Saying "I choose to code unsafely in C, and safely in C++, therefore C++ is safe and C is dangerous" is dishonest. And C++ has plenty of its own dangerous aspects, not just C compatibility.

Re: Why is BIND 10 written in C++ and Python?

#80

Post by eru »

mattmanser wrote: post #78
przemoc wrote: post #74

For core services like BIND I don't see any good reason to write them in more than one language (actually anything other than C/C++) and introduce cumbersome dependencies because of that. I wouldn't complain if it was some another DIY name server toy created for whatever reason (how much time it would take..., I can do it!, etc.), but it's software that will become widely deployed in upcoming years (almost) without d…

You can look at the source yourself. I don't understand either, randomly opening parts of both the Python and C++ and it's certainly not complicated and they write the Python in a C style anyway. I'm not a C++ coder and I only play with Python now and then, but can't say the code impressed me much. It's actually pretty hard to skim the code because it's massively over-commented and there are far too many tiny 2-line…

In general, abstracting code out into functions can be useful, even when the new functions is only called once.

That is because functions are a well understood abstraction. And having code separated into functions makes it easier for the reader to deduce the coupling points: two blocks of code after another can have all kinds of weird dependencies, e.g. the first blog might set some local variables that the second one relies on. But functions just have arguments and return-values.

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