# Objective
Because `prepare_assets::<T>` had a mutable reference to the
`RenderAssetBytesPerFrame` resource, no render asset preparation could
happen in parallel. This PR fixes this by using an `AtomicUsize` to
count bytes written (if there's a limit in place), so that the system
doesn't need mutable access.
- Related: https://github.com/bevyengine/bevy/pull/12622
**Before**
<img width="1049" alt="Screenshot 2025-02-17 at 11 40 53 AM"
src="https://github.com/user-attachments/assets/040e6184-1192-4368-9597-5ceda4b8251b"
/>
**After**
<img width="836" alt="Screenshot 2025-02-17 at 1 38 37 PM"
src="https://github.com/user-attachments/assets/95488796-3323-425c-b0a6-4cf17753512e"
/>
## Testing
- Tested on a local project (with and without limiting enabled)
- Someone with more knowledge of wgpu/underlying driver guts should
confirm that this doesn't actually bite us by introducing contention
(i.e. if buffer writing really *should be* serial).
dacb77d745