Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Using Rust for an Undergraduate OS Course

rust-class.org

Post reply on HN
Print view View original

31–40 of 72 posts

Re: Using Rust for an Undergraduate OS Course

#31

Post by bascule »

rdtsc wrote: post #6

> Go. Go is a systems programming language Not those kinds of "systems". It is funny, it seems initially it was meant to be those kind of "systems", and then it pivoted as we like to say, to become a "distributed-server-network-backend systems" not "hardware-kernel-OS" kind of systems. And then creators kinds of winged it and remarked how "well, that's what we meant when we said systems". As for Rust, yeah, there are…

Rust is a high-level systems programming language. Go is a low-level managed language runtime

Re: Using Rust for an Undergraduate OS Course

#32

Post by rdtsc »

mseepgood wrote: post #29
rdtsc wrote: post #6

> Go. Go is a systems programming language Not those kinds of "systems". It is funny, it seems initially it was meant to be those kind of "systems", and then it pivoted as we like to say, to become a "distributed-server-network-backend systems" not "hardware-kernel-OS" kind of systems. And then creators kinds of winged it and remarked how "well, that's what we meant when we said systems". As for Rust, yeah, there are…

> it seems initially it was meant to be those kind of "systems" From the announcement talk: "And it's a systems language in the sense that we intend it to be used to write things like web servers" http://www.youtube.com/watch?v=rKnDgT73v8s I don't think that Google ever wanted to develop a new OS kernel.

> From the announcement talk

From the announcement blog (and that was the widely circulated quote in tech news not the video transcript):

---

Go combines the development speed of working in a dynamic language like Python with the performance and safety of a compiled language like C or C++. [...] And the compiled code runs close to the speed of C [...] Go is a great language for systems programming with support for multi-processing ...

---

http://google-opensource.blogspot.com/2009/11/hey-ho-lets-go...

> I don't think that Google ever wanted to develop a new OS kernel.

As the meme goes, they keep using the word "systems", I don't think it means what they think it means.

Re: Using Rust for an Undergraduate OS Course

#33

Post by tinco »

johnhamlet wrote: post #15
dbaupp wrote: post #12

Earlier quoted context omitted.

No compiler can reason about whether some high-level piece of code is semantically order-of-execution dependent or not; not every non-deterministic piece of code is a race-condition.

You: "not every non-deterministic piece of code is a race-condition" Wikipedia: "A race condition ... is ... where the output is dependent on the sequence or timing..." Boom! Headshot!

The wikipedia article means the sequence or timing of the execution of the instructions in relation to each other.

Non-deterministic code does not only encompass code of which the results vary with the timing of instructions relative to each other, but also code of which the results vary with the timing of instructions relative to the state of the universe or anything in it.

Re: Using Rust for an Undergraduate OS Course

#34

Post by noahl »

johnhamlet wrote: post #15
dbaupp wrote: post #12

Earlier quoted context omitted.

No compiler can reason about whether some high-level piece of code is semantically order-of-execution dependent or not; not every non-deterministic piece of code is a race-condition.

You: "not every non-deterministic piece of code is a race-condition" Wikipedia: "A race condition ... is ... where the output is dependent on the sequence or timing..." Boom! Headshot!

    Boom! Headshot!
That adds nothing to the discussion and makes it feel more adversarial. It reduces the quality of discussion for no gain. Please don't do that again.

Re: Using Rust for an Undergraduate OS Course

#35

Post by kps »

Is there any support for the article's assertion that C uses ‘=’ for assignment (and ‘==’ for equality) “to save memory”? dmr simply described it as “a matter of taste”¹ and hinted that he was simply used to typing ‘=’ for assignment². [Edit: And the compilers didn't keep source in memory, anyway.]

¹http://cm.bell-labs.com/who/dmr/chist.html (also published in HOPL-II) ²History of Programming Languages II, Transcript of C Presentation, p692

(Nice to see Rust trying to bring progress to the C niche, BTW.)

Re: Using Rust for an Undergraduate OS Course

#36

Post by stephen_g »

This just doesn't make a lot of sense to me, given that almost all systems programming in the real world is done in C and C++, and given the complexity of OS kernels, we're not going to see a general purpose commercial grade one written in Rust either ever (if it falls out of popularity) or for ten to fifteen years (if it becomes very popular). This isn't like application or web programming - in comparison to web technologies it moves at a glacial pace. So I think teaching an OS course in Rust is going to leave them underprepared and be a big shock if the students actually go on to do systems programming on real systems.

The other thing is that I did an OS course in C, where we got dirty playing around in the depths of the Linux kernel, replacing the scheduler, writing a filesystem, and so on. It was damn hard, but probably one of the only courses in Uni that really pushed me as a programmer generally (everything else I found easy). I think that it really helps to have experience in unsafe languages like C, just like you really need to do at least a bit of assembly when you teach computer organisation.

Re: Using Rust for an Undergraduate OS Course

#37

Post by pcwalton »

stephen_g wrote: post #36

This just doesn't make a lot of sense to me, given that almost all systems programming in the real world is done in C and C++, and given the complexity of OS kernels, we're not going to see a general purpose commercial grade one written in Rust either ever (if it falls out of popularity) or for ten to fifteen years (if it becomes very popular). This isn't like application or web programming - in comparison to web tec…

I'm not sure the lack of safety is the pedagogically interesting part though. The interesting parts of writing a kernel for x86 are the low-level interfaces: assembly, I/O ports, the 8259A PIC, the fundamentals of scheduling, writing a slab allocator, and so forth. Rust allows unfettered access to those just as C does.

The lack of safety in C just means that the projects take longer to debug because the compiler doesn't catch as many mistakes; I don't think it adds much to the learning experience.

Re: Using Rust for an Undergraduate OS Course

#38

Post by frou_dh »

rdtsc wrote: post #32
mseepgood wrote: post #29

Earlier quoted context omitted.

> it seems initially it was meant to be those kind of "systems" From the announcement talk: "And it's a systems language in the sense that we intend it to be used to write things like web servers" http://www.youtube.com/watch?v=rKnDgT73v8s I don't think that Google ever wanted to develop a new OS kernel.

> From the announcement talk From the announcement blog (and that was the widely circulated quote in tech news not the video transcript): --- Go combines the development speed of working in a dynamic language like Python with the performance and safety of a compiled language like C or C++. [...] And the compiled code runs close to the speed of C [...] Go is a great language for systems programming with support for mu…

It's a tough crowd when being the authors of both the Unix and Plan 9 kernels isn't sufficient to get the benefit of the doubt on this matter!

Re: Using Rust for an Undergraduate OS Course

#39

Post by thirsteh »

2pxl wrote: post #18

"I'm not aware of any other language that has concurrency constructs as elegant and easy to use as Rust's spawn, and I don't know of any language that comes close to the race-free safety guarantees provided by Rust." I'd recommend having a look at Erlang, it allows you to start lightweight pseudo processes for concurrency and provides a robust data sharing model. Not so sure about low level access, we used C for thos…

> I don't know of any language that comes close to the race-free safety guarantees provided by Rust.

STM in Haskell.

Re: Using Rust for an Undergraduate OS Course

#40

Post by sixbrx »

stephen_g wrote: post #36

This just doesn't make a lot of sense to me, given that almost all systems programming in the real world is done in C and C++, and given the complexity of OS kernels, we're not going to see a general purpose commercial grade one written in Rust either ever (if it falls out of popularity) or for ten to fifteen years (if it becomes very popular). This isn't like application or web programming - in comparison to web tec…

You may be imagining that it will be complete OS/systems written in non-C language from scratch, but it doesn't have to happen that way.

With languages with no GC or optional GC, calling back and forth between the new language and C is easy and direct, and so writing only new (or maybe historically problematic) pieces of a system in the new language becomes feasible.

Post reply on HN