Interesting points, I’ve definitely run into memory constraints which resulted in completely unresponsive hosts a few times over the years. But as the author said, I don’t see this changing within any another of time due to the large scale archetectural changes required… The author also mentioned “I’m tempted to abandon using Windows, macOS and Linux as the main platforms with which I interact.”. Does anyone know which “daily driver” compatible operating system the author could be referring to?
Most UI Applications are Broken Real-time Applications
Submitted 1 year ago by lysdexic@programming.dev to programming@programming.dev
https://thelig.ht/ui-apps-are-broken/
Comments
harrim4n@feddit.de 1 year ago
Sanctus@lemmy.world 1 year ago
FreeBSD? Gentoo? There aren’t really that many options that are maintained depending on their definition of Linux. Might as well not use any computers at that point because you’d be on TempleOS with no internet and barely any colors.
ICastFist@programming.dev 1 year ago
It’s anyone’s guess, really. I can think of a few “exotic” OSs, like Solaris, Haiku (BeOS like), AROS (Amiga like and compatible), Kolibri and Risc OS, but I doubt the author would use any of those in any capacity.
Solemarc@lemmy.world 1 year ago
Maybe I’m dumb because I’m a backend dev, but if we can’t offload these tasks to Async tasks and we need to block the main thread, why can’t we just put up a loading screen? “Don’t turn off the application we are saving” games have been doing this for a decade and you can’t convince me that your enterprise application is heavier than a AAA game.
lysdexic@programming.dev 1 year ago
Maybe I’m dumb because I’m a backend dev, but if we can’t offload these tasks to Async tasks and we need to block the main thread, why can’t we just put up a loading screen?
That’s not the problem. These tasks can be offloaded to async. The underlying issue, and the reason why I think this is an outstanding article, is that running code on the UI thread straight from handlers is easy and more often than not it goes perfectly unnoticed. Only when the execution time of those handlers grow do these blocking calls become an issue.
There’s a gray area between “obviously we need to make these calls async” and “obviously we can run this on the main thread”, and here’s where the real-time mental model and techniques pay off.
atheken@programming.dev 1 year ago
The problem with the article is that it’s confusing hard realtime and low latency requirements. Most UIs do not require hard realtime, even soft realtime is a nice to have and users will tolerate some latency.
I also think the author handwaves “too many blocking calls end up on the main thread.”
Hardly. This is like rule zero for building gui apps. Put any non-trivial or blocking work on a background thread. It was harder to do before mainstream languages got good green thread/async support, but it’s almost trivial now.
I agree that there are still calls that could have variable response times (such as virtual memory being paged in or out), but even low-end machines are RAM-rich and SSDs are damn fast. The kernel is likely also doing some optimization to page stuff in from disk for the foreground app.
Its
Jummit@lemmy.one 1 year ago
Interesting viewpoint, but I think the applications aren’t at fault: The operating system should ensure that the user has control of the computer at all times. I think you need to do three things to achieve that:
- Limit process RAM usage, so the system never has to swap
- Limit process CPU usage, so the system never stalls
- When drivers / the operating itself crash, revert into a usable state (this one is probably the most complex one)
lysdexic@programming.dev 1 year ago
Interesting viewpoint, but I think the applications aren’t at fault: The operating system should ensure that the user has control of the computer at all times.
The whole point us that the OS does ensure that the user has control of the computer, at least as far as a time-sharing system goes. The problem is that the user (or the software they run) often runs code on the main thread that blocks it.
The real-time mentality towards constraints on how much can be executed by a handler is critical to avoid these issues, and it should drive the decision on whether to keep running a handler on the main thread or get it to trigger an async call.
verdare@beehaw.org 1 year ago
It is somewhat baffling that most interactive, consumer-facing operating systems are not real-time. I suppose that it’s a product of legacy and technical debt.
TerrorBite@meow.social 1 year ago
@verdare @lysdexic they are, but you have to be an enterprise customer.
https://ubuntu.com/blog/real-time-ubuntu-is-now-generally-available
https://learn.microsoft.com/en-us/windows/iot/iot-enterprise/soft-real-time/soft-real-time
RTOS are not going to become consumer operating systems, because there's too much value in selling it as a capability to enterprise customers (who are largely the consumers who REQUIRE a RTOS, rather than it merely being a convenience).
0x0@programming.dev 1 year ago
How can it be convenient for the desktop user to severely limit the amount or running processes? Desktop usage scenarios are the opposite of RT usage.
Vent@lemm.ee 1 year ago
This is a ridiculous definition of “real-time”. To accomplish this you’d need to subvert the kernal’s scheduler, otherwise you’ll always end up with “unbounded” response times since a single program can’t control what else is running or which clock cycles are allocated to it. What you end up with is an OS that only runs one process per thread.
Yeah, okay buddy. And I’m tempted to stop eating and sleeping because I’d like the extra free time.
lysdexic@programming.dev 1 year ago
You missed the whole point of the article.
It makes no sense to read the article and arrive at the conclusion that “I need to subvert the Kernel’s scheduler”. The whole point of the real-time analogy is that handlers have a hard constraint on the time budget allocated to execute each handler. If your handler is within budget them it’s perfectly reasonable to run on the UI thread. If your handler exceeds the budget then user experience starts to suffer, and you need to rework your implementation to run stuff async.
Vent@lemm.ee 1 year ago
The article is not talking about async processing. It’s talking about the process scheduler. It even has a section titled “Real-time Scheduling” that talks specifically about the process scheduler.
It’s simply not possible to fit the author’s definition of real-time without using something like an RTOS, and the author seems to understand that. The main feature of an RTOS is a different scheduler implementation that can guarantee cpu time to events. The catch is that an RTOS isn’t going to handle general purpose usecases like a personal computer very well since it requires purpose-built programs and won’t be great at juggling a lot of different processes at the same time.