publish-stable: atomic swap, no 404 window, stale staging cleaned #27
2026-11-10
publish-stable: swap the live dir with one atomic exchange; clean stale staging under a lock
The old swap renamed live aside and staging in: between the two renames /aqua/dings/ answered 404 (a concurrent reader got FileNotFoundError), a kill there left it missing until the next run, and a killed run leaked .stage-* dirs. Now renameat2(RENAME_EXCHANGE) swaps live and staging in one syscall, a per-target flock serialises publishers, and the next run deletes stale staging. test_interruption.py kills the publisher at every filesystem mutation (audit-hook counted), races readers against swaps, and fails against the old code. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>