pg_locks is the whole server's: under the parallel lane a worker's own advisory claim on the same playlist id, or its own lock wait, was counted by another worker's probe (a leak reported where there was none, a commit made before the second tab blocked).
VideoState, Playlist, PlaylistItem, SavedView, ComfortPin, Tag and ChannelTag leave app/models.py
for app/reader/models.py; app.tables registers them. No schema change.
The code cited its plan instead of saying why: `E28 review J4`, `(R6 S3b)`, `S1 justified…`,
`deep-review round 5`. That plan lives in the private ops repo, so for every reader of this one the
citation was noise, and a sentence whose subject was the plan step ("round 2 showed…") hid its
lesson behind an id. Each one is gone and the "why" kept: a bare citation is deleted, a sentence
carrying a lesson is reworded around it ("a later attempt showed…").
Measured (`scripts/audit_metrics.py`, product code): 652 lines in 270 files carried an epic code by
the definition the next commit holds (507 / 241 by the old, two-digit-only one) -> 0. Across all
code, tests, scripts and configs: ~1100 epic-code lines plus ~320 sprint/round ids.
Behaviour unchanged, checked mechanically: every changed .py file has the same AST once docstrings
are blanked; css/sh/toml/yml/json files are identical once comments are stripped; the only
non-comment changes in TS/JS are test titles, one description string in a contract table, and five
ESLint messages, whose text is all the gates snapshot diff holds. Not touched: Markdown (docs and
the changelog keep their history), Alembic migrations, TV episode notation (`S2 · E5`), DESIGN.md
ids (`C1`, `B4`, `S3h`), tracker ids (`SEC-16`, `DX-17`).
One stale claim fixed on the way: test_hls_reaper's docstring said the player checkpoints "every
10 s whether or not it is playing", which plex/stream.py calls wrong; it now says what the code does.
A delete landing while a push read YouTube left a plan over no items, so the push emptied the
YouTube playlist a local-only delete keeps: the push now stops at a vanished list (PlaylistGone,
404), and a delete is refused while a sync of the list runs. The closing baseline fingerprints the
title YouTube got, not the one its lock re-reads, so a rename made during the writes stays dirty.
The other-tab test helper bounds its lock wait, so a lock-order regression fails instead of hanging.
The mirror refresh re-ingested inside its row lock, and that ingest's commit let go of the lock
before the replace: a remove made then was undone and the list read as synced. Push, re-pull and a
delete touched items before the list row, a deadlock beside the playlist-first route edits. A push
now re-plans from the items under the lock and derives dirty after its YouTube writes.
lock_playlists moves to the sync package. Tests pin both ids of a move's lock and the claim's
own connection.
- Every playlist item write (add, remove, move, reorder, rename; Plex remove and remove-bulk) row-locks
the playlist before it touches an item, a move both lists in id order: remove beside reorder was a
deadlock, and two adds of one video a unique-key 500.
- The scheduled mirror refresh re-reads dirty under that lock, so an edit made during its YouTube calls
is not replaced by YouTube's order.
- A user's bulk pull holds a per-user advisory claim: two at once created duplicate mirrors. The manual
sync answers 409 sync_all_busy instead of '0 synced', and like the re-pull spends its cooldown only
on a pull that runs.
- Deleted mirrors are committed at once, not only when a later list commits.
- The claims open an unpooled connection of their own instead of a third pooled one per push.
The client's in-flight flag covers the menus of one page only. A push reads YouTube, then writes
both sides for seconds and commits step by step, so a row lock ends at its first commit: two tabs,
or a push and the scheduled mirror refresh, could interleave into a doubled YouTube item or a
baseline recorded over the other's writes. `sync_claim` takes a session-level advisory lock on a
connection of its own (it survives those commits; a crashed worker's lock dies with its
connection, so no claim column is left stuck). Push and revert answer 409 `sync_busy`; the
scheduled refresh skips a list being synced and picks it up next run.
peter