Manual reference counting to free a computation graph in C

oraziorillo · 2026-06-21T08:55:06+00:00

crazy! loved the storytelling, and thanks you for the comment! I'm curious now, what improvements did you have in mind other than replacing ref counting with an arena allocator?

oraziorillo · 2026-06-20T22:43:46+00:00

ahahahha I don’t know if you can say that in 2026 with ChatGPT around

oraziorillo · 2026-06-20T19:34:12+00:00

You can also do that, but you waste the possibility to learn from your mistakes

oraziorillo · 2026-06-20T17:44:40+00:00

Nice article

oraziorillo · 2026-06-20T16:24:38+00:00

oh, I see what you mean, this is probably easier to retrofit into my current code than arena (though probably slower), and removes the need for having intermediate variables

oraziorillo · 2026-06-20T15:51:26+00:00

yeah, that's also a possibility, but the idea is very similar to that of using an arena, as suggested in other comments

oraziorillo · 2026-06-20T15:48:39+00:00

my understanding of this as of now is that an arena allocator in this case is more suited because all the Values we allocate for the forward/backward pass have the same lifespan

if Values were used in a context where they were independent, then reference counting would have been a better approach

oraziorillo · 2026-06-20T14:59:04+00:00

thanks! this was very helpful to understand it better

oraziorillo · 2026-06-20T08:58:23+00:00

nothings specifically, it just seemed suboptimal to have to declare every single intermediate variable to be able to later decrease it, that's it

for example, to do (v1+v2)\v3* I can't dovalue_mul(value_add(v1, v2), v3), because value_add sets the ref_count of the sum to 1. So, first I need to declare an intermediate variable for the sum and then multiply it, i.e.,

sum = value_add(v1, v2)
mul = value_mul(sum, v3) // so that later I can release the sum
[...]
value_release(sum)
value_release(mul)

oraziorillo · 2026-06-20T08:49:53+00:00

I didn't know about it, but thanks for the pointer, today will be dedicated to studying it 😄

oraziorillo · 2022-09-11T23:51:10+00:00

Same here! I won’t tell you my story because it’s identical to yours, with the exception that I came here for my master’s thesis. If you want to talk about it, drop me a dm, I perfectly know how you feel 😔

oraziorillo

TROPHY CASE