Two simultaneous requests for the same nights could both pass is_available()
before either wrote its held row, double-booking the dates. Wrap the
is_available -> create_booking pair in a per-room asyncio.Lock
(_room_locks[room_id]) in services.request_booking, which both the HTTP and
RPC doors funnel through. FX + invoice creation stay outside the lock, so it
covers only the DB critical section.
Single-loop scope (LNbits runs one worker); documented the multi-worker
caveat (needs a DB-level guard) in event-flow.md and the crud.is_available
note.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019VUQCfdqiLSsFS2jcGnaFD
