There is one more way that is truly lock free. Most lock free implementations relying on atomic compare and swap instructions are not lock free afaik; they have a lock on the cache line in the CPU (in a way you go away from global lock to many distributed locks).
There is one more mechanism that allows implementing ring buffers without having to compare head and tail buffers at all (and doesn’t rely on counters or empty/full flags etc) that piggybacks on the cache consistency protocol
Those hardware-level locks are typically not considered because they work quite differently. A standard software mutex can cause other threads to block indefinitely if, for example, the thread holding the mutex gets preempted for a long time. "Lock free" isn't really about the locks, it's about a guarantee that the system makes progress.
In this sense, the hardware locks used for atomic instructions don't really count, because they're implemented such that they can only be held for a brief, well defined time. There's no equivalent to suspending a thread while it holds a lock, causing all other threads to wait for an arbitrary amount of time.
That's not how "lock free" is defined/used. If you are considering the MESI M state to be a "lock" then you also have to grant that any write instruction is a "lock".
In fact this a crux of the problem in low latency code and there are ways to combat this.
I know there is an academic wait-free and lock-free definition but folks use those often incorrectly as a slogan that something is magically better because it’s „lockfree”.
Imagine how _you_ would implement a read-modify-write atomic in the CPU and why E stands for exclusive (sort of like exclusive in a mutex)
Yes. [1] has background, [2] has the implementation (fig 2. pseudocode). Since you understood my comment I trust you can figure out the rest :) it’s a very neat trick.
I don't have to scan my face, upload my ID and share my biometric data with multiple 3rd parties, who will then lose and leak my private data, every time I drive a car.
This law isn't letting anyone use social media freely until they're suspected of not being an adult, at which point they have to age verify. It requires everyone to identify themselves whenever they want to view, interact, reply or share content on the internet.
This is not true. Its users suspected to be underage which will be asked.
Additionally, the law makes no judgement on the technology used to identify age, just that social media companies need to make an effort. I suspect that companies will not want to deal with the data security issues (very illegal to share pictures of underage people without consent), and will not be "sharing" with 3rd parties.
To comply with the law, platforms are gatekeeping content they deem controversial/NSFW/inappropriate/inconvenient behind age verification walls.
Everyone who wants to view, interact with or share that content has to verify their age to do so.
> I suspect that companies will not want to deal with the data security issues (very illegal to share pictures of underage people without consent), and will not be "sharing" with 3rd parties.
There are countless instances of exactly this happening, over and over again, not to mention that it's the way age verification's implemented now nearly everywhere lol
Pretty much every company will contract a 3rd party service to perform those checks, making sure they get as much bang for as little buck as possible. Said services are usually the weak link that shares the data with others, often through PNGs in public buckets so that Russian teenagers have an easy job CURLing them.
If the government took security seriously, it’d endorse a solution and then take responsibility for it, given it came up with the law in the first place.
The workaround is for everyone to coordinate , print and mail physical returns. Let IRS have fun with scanning and processing :) enough people do this, IRS would open up digital filing again
it’s a known effect. Without going into details here, you can calculate first crossing time of a barrier in a stochastic process and observe that often the first crossing time decreases as the volatility increases. From there you can set one barrier at 0 (default) and draw your own conclusion.
There is one more mechanism that allows implementing ring buffers without having to compare head and tail buffers at all (and doesn’t rely on counters or empty/full flags etc) that piggybacks on the cache consistency protocol
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