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Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

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Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#121

Post by wuuwoo »

tschellenbach wrote: post #101

I'm always curious why bluetooth is such a terrible piece of technology. Did anyone write blogposts analyzing what went wrong?

Any analysis would be less than insightful unless it comes from someone who sat in the meetings and helped write the standard.

FWIW Bluetooth isn't "terrible." It's pretty remarkable we can get all sorts of devices to communicate with eachother wirelessly and at low powers with pretty decent bandwidth. And now you can buy a Bluetooth stack on a chip from a variety of vendors.

The bigger issue with Bluetooth is that failure conditions are mostly an afterthought by device manufacturers, and Bluetooth is becoming a sought after feature in environments less than tolerable to failure like automotive and medical devices.

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#122

Post by merb »

glennpratt wrote: post #67
seanalltogether wrote: post #28

Earlier quoted context omitted.

Any insight into why Apple seems to have a much better bluetooth stack? I do a lot of BLE development that has to work cross platform, and we see constant GATT connection issues on android compared to almost none on ios.

Anecdotal, but my new 16 inch MBP drops BT connections all the time. I had to give up the keyboard and mouse I've used for years across at least 5 computers, mostly Mac's because they disconnected so much. Even the Apple keyboard and mouse I switched to drop occasionally.

the 16 inch mbp is full of bugs, so it's probably a problem with the device (typing with one and still crying because of https://forums.macrumors.com/threads/16-is-hot-noisy-with-an...)

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#123

Post by nicoburns »

Thaxll wrote: post #107
entropicdrifter wrote: post #47

Earlier quoted context omitted.

I mean, Mozilla migrated parts of Firefox to Rust, that's the big one. I hear it might start being included in the Linux Kernel soon.

It's not entirely true though, most of the code base is still C++ and there is no plan to migrate the rest.

Isn't that exactly what makes it successful partial migration?

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#124

Post by ampdepolymerase »

fouric wrote: post #31
jmull wrote: post #22

It seems like Rust is really catching on. To be honest, I didn't pay much attention to it for a while -- it felt like it might have simply been that day's "flavor of the day", destined to sink once then next flavor became popular. Now, there's a real problem to be solved. But I thought a simpler approach would be needed (e.g., Zig or something like it). I guess that may still happen, but seems more and more like Rust…

I suspect that Zig will still end up eclipsing Rust - not because it's a "more powerful" language, but because it's much easier to learn. Lower barriers of entry seem to matter more than mere "power" - see Common Lisp's multi-decade feature lead being ignored, and Python leapfrogging other more capable languages (Common Lisp) or equally capable ones that came first (Ruby) due to ease-of-use.

Common Lisp had itself and its community to blame. Their dependency managers were decades behind other scripting languages. Poor defaults for build tooling. Even now building a statically-linked binary is an exercise in frustration.

Despite being an ANSI specified language, the most popular libraries focuses only on SBCL. CL is like Lua where most interpreters never achieve 100% compatibility with each other. The lack of Emacs/Vim alternatives demands beginners to adhere to their dogma. Adhering to their cargo cult might be reasonable if they are the dominant language and culture. But they are not. Software engineering classes in university teaches how to make Java AbstractSingletonProxyFactoryBeans first and caml/lisp much later. Common lisp had it coming when they had their lunch eaten by Clojure. They were an old irrelevant relic that sat on their ivory tower and refused to improve or confront the status quo beyond empty words.

And it is not like the Common Lisp community lacks resources. They claim their language is used at Google via ITA software and in GOFAI through Grammarly. Even the bleeding edge of computing through Regetti. Then where are all the maintained, up to date tooling and libraries? Do a quick search and almost everything is unmaintained or half dead, with the usual generic excuse being "we are ANSI specified, libraries twenty years ago will work perfectly fine".

HN is an echo chamber for the greatness of Lisp where every commenter would worship at its church before going back to coding JS/Python/Java on Monday.

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#126

Post by mondoshawan »

toast0 wrote: post #108
mondoshawan wrote: post #40

Earlier quoted context omitted.

Apple has a unique relationship to its hardware, and the money to bend vendor's firmware to their will. Half of the problem with Bluetooth is the host stack. The other half is the firmware running on the controller on the other side of HCI. If the controller ever gets screwed up, the host stack can only disconnect from HCI and totally restart the controller.

The third half is the bluetooth firmware on the other device. The fourth half is the other firmwares on the other device. The fifth half is the specification(s). The sixth half is the RF environment.

Haha -- yes, indeed. Bluetooth the spec and implementation are an absolute dumpster fire.

"Bluetooth is a layer cake of sadness" is the turn of phrase we used for a while on the Glass connectivity team. One of our project founders, Thad Starner actually apologized to me for the mess it became; apparently it was supposed to be simpler, but when Nokia took ownership back in the 90s, it started to go downhill.

Our lead on the connectivity team at the time had a crazy idea to rewrite the spec using only ACL and L2CAP, but never really went anywhere with it because of the the Glass org implosion.

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#127

Post by [deleted] »

zozbot234 wrote: post #79
kevincox wrote: post #52

Earlier quoted context omitted.

I think the answer is yes. Most C++ projects would be better served by Rust. However there are many caveats: - I think that C++ devs are still more numerous than Rust devs. - There are many excellent C++ libraries that don't yet have great Rust bindings. Furthermore it is unlikely that template-heavy libraries will ever be easy to use from Rust. - C++ is supported on more platforms. - C++ is more powerful. (Particula…

Meta-programming needs in Rust are addressed by macros. There's not really anything missing there compared to what C++ does via templates.

[deleted]

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#128

Post by PragmaticPulp »

stagger87 wrote: post #27

If you go into the parent directory, what appears to be the main Gabeldorsh directory, most of the implementation appears to be written in C++. Is the project being slowly rewritten in Rust? Or are only parts of it written in Rust?

I’m not finding much Rust BlueTooth Stack code in the link. There are only about 4K lines of Rust in here.

Am I missing something? Or is the headline exaggerated?

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#129

Post by steveklabnik »

oriolid wrote: post #111
steveklabnik wrote: post #98

Earlier quoted context omitted.

I mean, C++ has the "class" and "struct" keywords for a reason. (they are very similar, Rust structs are closer to "struct" than "class" though) There are a lot more things going on with C++ classes than syntax sugar for functions that have access to "this." Also, while not in C++, in many languages, classes imply heap allocation, where structs do not.

What's the difference between struct and class in C++? IIRC the standard says they're the same except that members are public by default on struct and private by default on class. You could as well argue that C++ doesn't have structs. The different allocation between structs and class objects in C# is a total head scratcher. Didn't it ever occur to the language designers that someone might want to choose how to alloc…

So, I dug into this a bit more, and you're right!

https://www.fluentcpp.com/2017/06/13/the-real-difference-bet...

Maybe it was the era that I learned C++ (which was in the 98 days), but I was taught something closer to this convention, and didn't realize until just now there was such little difference by the book. Just bundling some data together? Use a struct. Doing more? Use a class.

I still think this distinction is useful overall, because there often is more of one in many languages, but I will be more precise when speaking about C++ specifically in the future. I would also still argue the same thing overall, that is, Rust does not have what C++ calls classes. Our structs are apparently even simpler than C++ structs.

Re: Android's new Bluetooth stack rewrite (Gabeldorsh) is written with Rust

#130

Post by cmyr »

glennpratt wrote: post #67
seanalltogether wrote: post #28

Earlier quoted context omitted.

Any insight into why Apple seems to have a much better bluetooth stack? I do a lot of BLE development that has to work cross platform, and we see constant GATT connection issues on android compared to almost none on ios.

Anecdotal, but my new 16 inch MBP drops BT connections all the time. I had to give up the keyboard and mouse I've used for years across at least 5 computers, mostly Mac's because they disconnected so much. Even the Apple keyboard and mouse I switched to drop occasionally.

I think there might be some issue on that hardware where 2.4ghz wifi and bluetooth share an antenna, and can interfere with each other? If you're using 2.4ghz and can use 5, give that a try.
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