# Objective
- Fixes#18617
## Solution
- Added `thread::sleep` to `bevy_platform_support` using a spin-based
fallback.
- Fixed bug in `bevy_platform_support::time::Instant::elapsed`
(comparison was backwards)
- Switched `ScheduleRunnerPlugin` to use
`bevy_platform_support:🧵:sleep` on `std` and `no_std` platforms
(WASM + Browser excluded)
## Testing
- Ran reproduction code from @mockersf in linked issue and confirmed a
consistent 60 counts per `println!`.
---
## Notes
- I chose to add `bevy_platform_support:🧵:sleep` instead of
putting the fix in-line within `ScheduleRunnerPlugin` to keep the
separation of concerns clean. `sleep` is only used in one other location
in Bevy, `bevy_asset`, but I have decided to leave that as-is since
`bevy_asset` isn't `no_std` compatible anyway.
- The bug in `bevy_platform_support::time::Instant::elapsed` wasn't the
cause of this issue, but it did prevent this fix from working so I have
included the it in this PR.
7925e03f7f