Module coordination 

Cooperative cold-miss coordination through nonblocking advisory file locks.

All producers for a namespace must use the same stable lock files. Do not unlink or replace .lock entries while any producer can use the directory: doing so would allow independent locks on different inodes for one key. Contended locks return without waiting. Hosts choose retry and cancellation policy; descriptor and filesystem operations remain synchronous. Filesystem and mount settings determine the scope of advisory locking. See https://man7.org/linux/man-pages/man2/flock.2.html.

Structs

Lease

An exclusive producer guard. Dropping it explicitly unlocks and closes its descriptor. The empty lock file remains for future producers.