burst-safety

Burst Safety

This is a skill pack, not an agent. Load when triage marks domain=DOTS|Hybrid.

Hard Rules (do not violate without architect approval)

1. No managed types in [BurstCompile] code paths. No string, List<T>, Dictionary<K,V>, class, object, boxed value types, delegates, or try/catch (managed exceptions).
2. No static mutable state. Statics must be readonly and reference only blittable types. [BurstCompile] does not see managed singletons.
3. No reflection. typeof(T).GetField(...), Activator.CreateInstance, Marshal.* — all forbidden inside burst.
4. No virtual dispatch. No interface calls on instances; use static methods, generic constraints, or function pointers.
5. fixed blocks must use UnsafeUtility.AddressOf for managed objects — in practice this means do not need fixed at all in burst code.
6. Math: prefer Unity.Mathematics. math.sin, math.length, float3/int3, not Mathf.* or Vector3 (those are managed wrappers).
7. Debug.Log is forbidden in [BurstCompile] methods. Use UnityEngine.Debug.Log only outside burst, or [BurstDiscard] on a small log helper called from non-hot paths.

Diagnostic Checklist Before Signaling Verifier

For every system or job you wrote or modified:

• [BurstCompile] is still on the method/struct if it was there before. Removing it requires [BLOCK: performance] escalation.
• Burst Inspector (or BurstCompiler.Enable = false toggle test) shows the method compiles without warnings.
• No string, List, Dictionary field added.
• No try/catch in [BurstCompile] body.
• No Debug.Log introduced in the hot path.
• If you needed scratch memory: NativeArray<T> with explicit Allocator.Temp (frame-scoped) or Allocator.TempJob (job-scoped), and disposed in the same frame/job.

Common Burst Bugs (do not repeat)