[perf] Make projectile cleanup deterministic in OnSecondUpdate

[Xekep]

Summary

• run recent projectile cleanup directly in second-update path
• remove stale entries in place with RemoveAll under lock

Scope

• focused change in Bouncer.OnSecondUpdate only
• no unrelated file changes

[hakusaro]

@greptile review

[greptile-apps]

Greptile Summary

Refactored projectile cleanup in OnSecondUpdate to run synchronously instead of in a background task, improving determinism and thread safety. The changes include switching from DateTime.Now to DateTime.UtcNow, optimizing cleanup with RemoveAll instead of Where().ToList(), and calculating the threshold once before the loop for better performance.

Key improvements:

• Eliminated potential race conditions by removing Task.Run - cleanup now runs on the main thread where all handlers access the projectile list
• More efficient memory usage with in-place RemoveAll instead of allocating new lists
• Consistent time handling with DateTime.UtcNow
• Threshold calculated once instead of per-player

Note: Documentation in TSPlayer.cs:1053 still references async execution and should be updated.

Confidence Score: 5/5

• This PR is safe to merge with no risk - it improves both correctness and performance
• The changes are well-focused and actually improve thread safety by eliminating async execution that was causing potential race conditions with unlocked reads throughout the codebase. The logic is equivalent, more efficient, and more deterministic.
• No files require special attention - the change is straightforward and correct

Important Files Changed

Filename	Overview
TShockAPI/Bouncer.cs	Improved projectile cleanup by removing async execution, using UTC time, and optimizing with RemoveAll instead of Where().ToList()

_{Last reviewed commit: 584073c}

[greptile-apps]

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

Additional Comments (1)

TShockAPI/TSPlayer.cs
documentation is outdated - cleanup no longer runs in an async task

		/// Keeps track of recently created projectiles by this player. TShock.cs OnSecondUpdate() removes from this synchronously.