An insane idea on reference counting [pdf] | Hacker News Reader

An insane idea on reference counting [pdf]

epicsol.org

58 points_kp6z25 comments

The work gleb is showing here pretty much looks to be proxy collection, which also has a whole parade of patents. An interesting mechanism with good performance characteristics is defined at http://concurrencykit.org/presentations/ebr.pdf and is easily pluggable into an RCU implementation.

Do you know more about this patents?

If writes are infrequent and readers issuing atomic operations on the same word is expensive, why not use a set of read-write locks? Reader contention on any given lock would be amortized over the set; the cost is eaten by writers who must write-lock all the locks.

Could something like tokens from dragonfly BSD be adapted in the way that Matt mentions:

http://lists.dragonflybsd.org/pipermail/kernel/2004-February...

Is the RCU patent really still an issue?

> Is the RCU patent really still an issue?

Only for BSDs; RCU is free to use under LGPL and GPL.

(It was originally only usable under GPL. Later on, after Mathieu Desnoyers implemented a userspace version "liburcu", IBM granted permission to use RCU under LGPL to allow liburcu to use that license, making it more universally usable by arbitrary userspace software.)

Why wouldn't it be?

It must be getting close to expiry at this point -- wasn't it filed in the mid 90s?

EDIT:

I did a little digging and some calculations in the USPTO's horrible, horrible expiry calculator and the list of patents in wikipedia (which TBH, I haven't dug into to figure out how relevant they are but the list below is roughly ordered from "fundamental" to "interesting things you can do with RCU"):

http://www.google.com/patents/US5442758 -- should have expired last year

http://www.google.com/patents/US5608893 -- will expire very shortly, but is noted as "lapsed" due to non-payment of fees

http://www.google.com/patents/US5727209 -- will expire next year

https://www.google.com/patents/US6219690 -- this one will be a few more years

http://www.google.com/patents/US6886162 -- even longer

Good digging.

If the original RCU patents are expired, it might make more sense for the BSDs to start to use RCU, it makes things much easier in the long run, and should scale a lot better than this proposed solution.

Greg, if you know anybody that has some pull on these kinds of things within IBM, can you contact The FreeBSD Foundation? We might need some kind of "FreeBSD and derivative" exemption or an interpretation of the unexpired patents effects on an RCU implementation. Justin Gibbs said last time he tried to contact IBM he got directed immediately to legal staff and does not have a good contact within IBM.

Try contacting the Linux kernel RCU maintainer, he should be able to look into if IBM is willing to do this or not.

Odds are, they are not, it was a very specific decision to let this be a GPLv2 only patent grant, but as I haven't worked for IBM for almost a decade, I can't speak for them in any form (not that I ever could...)

> If the original RCU patents are expired, it might make more sense for the BSDs to start to use RCU, it makes things much easier in the long run, and should scale a lot better than this proposed solution.

Optimizations and new versions of RCU are patented as well: preemptible variations, scalability optimizations, tiny/embedded variations, and many common data structures.

However, I agree that even the most basic RCU implementation will scale far better than referencing counting for many applications.

Why is it patentable?

The Patent Office considers everything patentable. Last month they issued a patent on literally calling up two pharmacies to pick the one that offered your drug cheaper. They even fast tracked that application and didn't ask a single follow up question about it.

I hadn't heard of that one and can't find anything about it. Do you have a source?

Patent:

http://www.google.com/patents/US8712797

Discussion:

http://patentlyo.com/patent/2014/05/business-method-patent.h...

Urgh, no, they don't. If you're ignorant about an issue, you should ask questions, not speak authoritatively about it. And yes, you are clearly ignorant about the issue. I'd guess you would also believe "Amazon just got a patent for taking a photo of something in front of a white background", right?

If you mean this [1], then they convinced the USPTO that their process for taking pictures with a white background and making it look good (F-stops, ISO settings, etc.) was patentable. And of course, the patent says "It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure."

Because you could, of course, use other F-stops, ISO settings, etc. That would be really obvious. The whole set it up with good settings a normal photographer might use? That's the original part.

This reminds me of Apple's design patent on a design where "rounded corners" were basically the only feature anyone could name that was similar to Samsung's. So technically they didn't patent rounded corners... they just accused Samsung in court of infringing it with a phone where that was the primary similarity.

This is all part of a big game where patent lawyers find meaningless "limitations" like this to distinguish themselves from the prior art to the USPTO, then come back to the federal courts and demonstrate just how meaningless they are as they assert what might as well be as bad a patent as is the popular understanding.

[1] http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=H...

I don't think I could agree with you less. The Amazon patent claims are EXTREMELY narrow and specific; any deviation from what's claimed (changing F-stop, ISO, number of lights, etc.) is not within the scope of the claim and is therefore not patented and free to be used. You emphasised that making such changes would be obvious, and yes, I agree, but that's irrelevant unless someone tries to patent a similar process with some of those changes made.

    "It should be emphasized that the above-described embodiments of the present disclosure
    are merely possible examples of implementations set forth for a clear understanding of the principles
    of the disclosure."

Please read the above link about how to read a patent. That has absolutely no baring on the scope the pqatent covers. It's just there to cover the lawyer's arse when the examiner tries to say "Your claims don't match your examples so it's not [reasonably based on the description]#". Examples are necessary in a patent application, but should not be used to limit the scope of the actual invention defined by the claims if all the information to produce all embodiments of the invention would be reasonable ascertained from the description.

Again, why on earth bring up the Apple DESIGN patent? They are practically unrelated topics. It's like saying a Nissan GT-R is a shitty car because you don't like the Tiida (hmm, does that geolocate me too much?). just because they both have patent in the name does not mean that one is related to the other.

# I'm not sure what the US term here is, in most of the world it's "fully supported by the description"

You may be right and can argue all you want. It is utterly meaningless in the real world sadly. What you are saying is how the patent system should work, but cannot. You are leaving out the human factors that ruin it.

All it takes is someone to sue you for use of your novel use of an existing idea and you are dead in the water despite it being valid. Most small companies let alone open source communities have no legal resource to defend themselves even if they are demonstrably in the right.

This is all precisely why it shouldn't not be possible to patent minor abstract symbolic expressions of basic human problem solving. It's like suing a child for learning how to walk for having a patent on walking. Simultaneous invention is normal and healthy.

You're right that they technically patented some narrow thing, and that they're trying to avoid limiting the scope of their patent. I am well aware of the fact that a design patent is a separate class of thing, I brought it up because it shows how lawyers being too good at avoiding limitations is a large part of the unreasonableness. When you get right down to it, you can see where they end up demanding hundreds of millions over ridiculous trivialities because triviality is too subjective and they'd rather have a bright line in a stupid place.

Having watched the motion practice for how these actually play out in court, however, I know how they can dance around all the limitations to the point where "they didn't actually patent taking photos on a white background" becomes academic.

At least this is how it plays out in the US. It's possible that other countries have a saner patent system and I would rather like to believe that, but I do not claim much familiarity with how patents are used outside the US.

The patent system in the US is definitely very sick, and much more open to abuse than elsewhere in my experience. There should be much greater penaqlties for entities who sue and lose, and also the first action in any patent cqase should be the deep assessment of the patent's validity (in the US, the doctrine is that the patent office got it right and the patent is valid). If it were a matter of contract law, the contract would have to be found valid before continuing with any prosecution, but not wiuth the social contract probided by a patent.

Someone being sued has a much greater imputus to find relevant prior art than the patent office (not that the office doesn't want to find it, they just don't have time to go the lengths that might sometimes be required). There also seems to be a lot of common sense missing in the US system (and US law in general).

I'd propose a more constructive reply next time. For example a reply that links to http://www.danshapiro.com/blog/2010/09/how-to-read-a-patent-...

There's no need to be rude (and being right typically doesn't excuse it)

I believe that should be called out when they're outright lying as the commenter I was replying to clearly was (though probably doesn't know it). I've tried being more "constructive" in the past, and it never does any good; people like remaining ignorant so they can feel indignant

You can't lie if you don't know it, lying has a purpose component.

Reply on news.ycombinator.com