{"id":"wal-single-writer-thread-level","text":"The WAL enforces single-writer via `threading.Lock` but has no inter-process locking mechanism (no flock/PID file), so the single-writer invariant holds only within a single OS process","truth_value":"IN","source":"entries/2026/05/29/topic-wal-size-check-toctou.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"wal-single-writer-thread-level","truth_value":"IN","reason":"premise"}]}}