Module lock 

Store ownership via a process-local registry and an OS file lock.

Two mechanisms are needed, because neither alone is sufficient:

• The process-local registry provides same-process exclusion. POSIX record locks do not conflict between descriptors held by one process, so without the registry a second Store in the same process would be admitted. Windows byte-range locks do conflict per handle, even inside one process, but the registry is still what keeps the two platforms on one contract: it owns exactly one descriptor per store, counts the local shared holders, and refuses a conflicting mode before any lock call, so admission does not depend on which platform is answering.
• The persistent writer.lock provides cross-process exclusion and is released by the operating system when the holder dies, orderly or not.

The registry is keyed on the store directory’s stable filesystem identity — (st_dev, st_ino) on Unix, (volume serial, file index) on Windows — never on path text, so case differences, separator differences, relative versus absolute spellings and supported junctions all converge on one store.

Nothing else in this process may open STORE_LOCK_FILE.

Structs

StoreLock

Exclusive writer ownership automatically released when the process dies.

Enums

StoreLockError

Failure to open or acquire the single-writer lock.

Constants

STORE_LOCK_FILE

Persistent lock filename; only StoreLock may open this file.