Fix a command buffer leak that occurs in D3D12

[alessand10]

This PR should fix: #94251

Memory allocated for command buffers in DX12 is never freed. In Vulkan, freeing the command pool also frees the command buffers that have been allocated within the pool. This fix mirrors Vulkan behavior by having each command pool track their respective command buffers. When a command pool is freed, its command buffers are as well.

[clayjohn]

Makes sense to me.

I would like @DarioSamo or @RandomShaper to take a quick look as well before we merge

[RandomShaper]

The rationale makes sense. However, the implementation fails to follow the 'as close to zero allocations as possible' mindset. I think you could use SelfList to achieve that.

[clayjohn]

@alessand10 Could you make the change requested by RandomShaper? I think after doing that, this should be ready to merge

[AThousandShips]

You accidentally wiped your branch when trying to restore, to get back to before the rebase please use git reset --hard 6ed73b1 and try again

[alessand10]

@AThousandShips Sorry for the trouble. Will I need to create a new PR?

[AThousandShips]

No you can solve this one, try:

git reset --hard 6ed73b1

And then try to rebase again, and then finally:

git push --force

I'd help but I'm away from my computer right now

[clayjohn]

Looks great! The final step before merging is to squash all the commits together so that the whole PR only contains 1 big commit with all your changes. We like to merge one commit at a time to keep the git history clean and navigable.

If you don't know how to do that, we have a helpful tutorial in the official documentation https://docs.godotengine.org/en/latest/community/contributing/pr_workflow.html#the-interactive-rebase

[alessand10]

@clayjohn @AThousandShips Thank you for your help and guidance!

[RandomShaper]

Sweet!

Just left a little suggestion, but feel free to ignore it. I consider this is fine the way it already is.

[clayjohn]

Thanks for your quick responses to feedback! That was a bit of a whirlwind day. But it looks great to merge now

[alessand10]

@clayjohn My second PR was definitely more chaotic than I was aiming for, but I appreciate everyone's help and I'm looking forward to learning more about the engine and contribution process. Thanks again!

[akien-mga]

Thanks!