Sequence lock

A synchronization primitive where a writer increments a version counter to odd before and to even after an update, and lock-free readers re-read the counter and retry if it changed mid-read, giving very cheap reader-side access to rarely-written shared data.

grounded in: latest AI/tech trends theme: 'Rust and the hard edges of systems concurrency' — a lasting reader/writer primitive distinct from the existing lock pathologies (deadlock, lock-convoy, priority-inversion