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Hacking Coroutines into C

(wiomoc.de)
135 points jmillikin | 3 comments | 13 Jul 25 01:12 UTC | HN request time: 0.614s | source
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Nursie ◴[13 Jul 25 05:41 UTC] No.44547796[source]▶
Cooperative multithreading via setjmp and longjmp has been around in C since the 80s at least.

I’m not sure this is so much hacking as an accepted technique from the old-old days which has somewhat fallen out of favour, especially as C is falling a little outside of the mainstream these days.

Perhaps it’s almost becoming lost knowledge :)

replies(1): >>44548029 #
1. ajb ◴[13 Jul 25 06:39 UTC] No.44548029[source]▶
This isn't using setjmp/longjmp

It's using Simon Tatham's method based on Duff's device (https://www.chiark.greenend.org.uk/~sgtatham/coroutines.html)

replies(1): >>44548333 #
2. Nursie ◴[13 Jul 25 07:44 UTC] No.44548333[source]▶
Sure, I guess I just wanted to point out that regardless of method, people have been building these sorts of facilities in C for a very long time.

It doesn’t lessen the achievement of course, but it amuses me an in “everything old is new again” kinda way.

replies(1): >>44549248 #
3. johnisgood ◴[13 Jul 25 10:41 UTC] No.44549248[source]▶
"everything old is new again" is so true. I see it across IT all the time, heh.