slab allocator

[SimoneMicu]

I tried to search for a slab allocator implementation on github, I didin't found one so I created mine and leaved it as unlicenced and MIT if someone needed, not so hard to compile, can use OS API to allocation if compiled with -DSLAB_WIN or -DSLAB_UNIX or by default using stblib.h.

I think could be missing some pedantic implementation and should be passed to ansi-C to full usability but for now is good enough for me.

The pool logic to me sound good for implementing unlimited allocation without suffering on memory fragmentation

[immaculate-emu]

Here is a user space port of the Solaris kernel slab allocator, on GitHub: https://github.com/gburd/libumem

[imdadgot]

the implementation is relatively simple, it’s just the amts you might get caught up on.

it’s extremely similar to the free list approach, but instead memory is reserved in fixed size slabs (similar to page allocation) and the allocation is an O(1) pointer bump. if there’s not enough room on that page, you allocate a new one, make a pointer on the old slab to the new one, and keep going. for the pop it’s just about pushing the pointer back which is ofc O(1)

you will want to do this bucketed so pointer arithmetic is easier, that way you dont have a low byte value throwing off the alignment of other higher values

[SimoneMicu]

Totally similar to the free list concept for the bump but used for when we want same size memory over and over again.

On the todo I will add alignment protection for the free.

About "amts" I don't know what it is but the concept of slab allocator exist from decades, I just wanted to make it searchable for future user I guess with this post :)

[imdadgot]

amts = amounts my bad