Safe Memory Reclamation for lock-free structures — threads publish hazard pointers; a retired node is held until no slot references it, then freed.
| Operation | Cost | Notes |
|---|---|---|
| protect (publish + validate) | O(1) | store + StoreLoad fence + re-read; may retry |
| clear slot | O(1) | store null — unpins the node |
| retire | O(1) | append to thread-local list (never free) |
| scan + reclaim | O(R + H·K) | amortized O(1) per node at threshold ≈ 2·H·K |
| held memory | Θ(H²·K) | bounded; stalled reader pins only its K slots |