The Vulkan allocator

[i509VCB]

Scope

First is a thin lightweight wrapper around ash to get an Instance and PhysicalDevices. This helper is kept intentionally lightweight to prevent essentially replicating a crate like vulkano. Creation of a logical Device is intentionally not covered since extensions to DeviceCreateInfo and queue creation are hard to model in a public API. The Vulkan allocator and a future renderer are expected to initialize their own logical device(s) and queues.

The Vulkan allocator is modeled around the Allocator trait. Implementing memory import/export and dmabuf import could be done, but it involves much more complex lifetimes (since memory import/export requires copy commands, which means command execution and needing to delay destruction of images until command execution finishes). In the future we could expand the allocator api to handle this as an alternative to gbm's memory import/export functions. This may be harder to do but will allow custom Vulkan renderers to be build more easily (since all the external memory logical will be in one type you can just pull in).

There are a few things we do need to do before merging:

• A new ash release (Release ash 0.37.1 ash-rs/ash#632). 0.37.1 will not eliminate the builders, so if we do not want to wait for 0.38.0 then we will need to readd the builders. Will use 0.37.1 pre-release with a set revision for now.
• Double check we do not have validation errors.

[codecov-commenter]

Codecov Report

Merging #614 (1967a3e) into master (01ffd33) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #614      +/-   ##
==========================================
+ Coverage   31.04%   31.06%   +0.01%     
==========================================
  Files          84       84              
  Lines       13770    13770              
==========================================
+ Hits         4275     4277       +2     
+ Misses       9495     9493       -2     

Flag	Coverage Δ
wlcs-core	28.50% <ø> (+0.01%)	⬆️
wlcs-output	10.47% <ø> (ø)
wlcs-pointer-input	30.65% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/backend/allocator/mod.rs	0.00% <ø> (ø)
src/desktop/space/mod.rs	59.23% <0.00%> (+0.36%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 01ffd33...1967a3e. Read the comment docs.

[Drakulix]

Looks mostly good, some questions: