Implement freelist class

[gavv]

Subtask extracted from #602. See that task for rationale.

Add new class core::Freelist<T>, which implements lock-free free list based on this article:
Solving the ABA Problem for Lock-Free Free Lists

It should be modeled after core::List<T>. It should implement lock-free LIFO based on singly linked list, with just two operations: push_back() and pop_back(). It should be intrusive, just like core::List, i.e. elements should inherit node class, so that node data is embedded into element instead of being allocated separately.

We also need to cover it with unit tests.

[nataliayave]

Hi, I am interesting in solving this issue. This would be my first time contributing to an open source project. Where would I find where this issue is taking place? Which file should I be working on?

[gavv]

Hi, thanks.

It belongs to roc_core module. See here: https://roc-streaming.org/toolkit/docs/internals/code_structure.html

[mihir-mihir]

I'd be interested in giving this one and/or #602 a shot, @nataliayave are you still working on this? I can pick up #602 after if you are, otherwise I can take both

[gavv]

@mihir-mihir While we're waiting for reply from Natalia, probably you'd be interested in #749, which is also about lock-free programming.

UPD: Oh, and there is also #362, which was abandoned a while ago, but I think is pretty interesting.

[mihir-mihir]

Thanks, I've commented on #749

[gavv]

@mihir-mihir I guess we can assume that the issue is free, please ping me if/when you want to be assigned.

[mihir-mihir]

@gavv yes I'll take this one thanks

[gavv]

Awesome

[veronikaro]

Hey @mihir-mihir, are you still working on this?
@gavv if not, could you please assign me to the issue? I would like to give it a go.

[mihir-mihir]

Hi @veronikaro, go ahead

[Ahilan001]

Hi, I know I didn't request the issue here, but I have been working on it too. I am going to finish working on the issue today, so would it be okay to make a pull request when I finish it?

[gavv]

@Ahilan001 The patch you sent is confusing, looks like some random pieces of code?.. And it doesn't compile. Also please read coding guidelines: https://roc-streaming.org/toolkit/docs/development/coding_guidelines.html

Veronika, it would be great if you could take this issue :) @veronikaro

[veronikaro]

@gavv thanks, will do! :)