[s3graham]

Ah, that video brings back nice memories of bleary-eyed nights in the Real-Time lab. :)

... That and rage at the crappy, broken, unreliable sensors we had at the time. Damn hardware always messing with pretty software abstractions.

What was your gratuitous fluff process to "prove" that the OS was mostly real-time-ish?

[eworoshow]

Demonstrating that the OS was real-ish time consisted of showing that (1) it never dynamically allocates memory, (2) it uses constant-time algorithms. More practically I did a bunch of timing to show that, under real loads, it generated responses under certain (arbitrary) thresholds. In conclusion: a process lacking even the smoke and mirrors of rigor.

[s3graham]

Sorry, I didn't mean to imply your measuring process was fluff.

When I did 452 we had to do something on-screen, to demonstrate responsiveness. I did the "water demo effect" (similar to http://www.derschmale.com/demo/pixelbender-water/PixelBender...). It had to animate without hitching under load, which I guess correlates with your response timing tests (the arbitrary threshold being 60 or 30 Hz in this case).

Anyhoo, I meant "process" in terms of OS-level process, and "fluff", because mine was just lame graphical fluff. :)

btw, planning any more co-op terms before you graduate? Drop me a line.

[eworoshow]

Ah, I guess the course requirements have changed in the intervening years. We got somewhat less time to work on the OS "thanks" to renovations in the lab; none of us had time to get a full, graphical VGA display running.

That said, I think your display better demonstrates real-time-ness than my somewhat-less-than-rigorous measurements. By the time you account for all the assumptions I made to get semi-complete numbers, a working demonstration of a real-time process is far more convincing!