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https://entire.com/gh/paperclipai/-/trails/69/changes/paperclip/69
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## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Operator Stop must revoke task authority before it stops provider
execution.
> - Its transaction locks the task and then the run. A concurrent writer
can hold the run while it waits for the task.
> - PostgreSQL can abort the Stop transaction with a confirmed deadlock.
The cancel API then returns 500.
> - This pull request retries only that aborted database transaction, at
most three times.
> - Provider Stop and activity publication stay after commit, so the
retry cannot repeat those effects.
## Linked Issues or Issue Description
Refs #17639. Its agent-chat project browser test completed the product
assertions, then failed during cleanup when the cancel API returned 500.
A real PostgreSQL lock-cycle test reproduces the same `40P01` error in
the Stop transaction.
Related: #13911 addresses audit foreign-key lock contention. This change
handles a different concurrent run-writer path without changing the
schema or task/run lock order.
Stack base: #17639. This is a separate correctness repair for the sleep
migration stack, not another polling migration.
## What Changed
- Control the runner timeout regression fixture's clock so it reaches
the pending append before expiry; retain production cancellation and
late-append assertions.
- Retry the Stop authority transaction only after PostgreSQL reports
`40P01`. Make at most three attempts, with short bounded backoff.
- Discard rolled-back local run state, claim flags, and queued activity
publications before each retry. Re-read current authority under fresh
locks.
- Keep provider cancellation and activity publication outside the
retried transaction. Preserve other errors and the existing native
lock-conflict response.
- Add a real two-transaction deadlock test. Add server-side failure
tests for retry exhaustion and errors that must not retry.
- Let run-control tests use a validated disposable PostgreSQL database
URL.
## Verification
Published head: `60ba892ae9fc5faaf8cd0833694b4a66c13323c3`, targeting
master after #17639 merged at
`1ed0af41867ba40fd1d23292d395588d18c2fcbe`. The normal ancestry merge
preserves the complete five-path tested cancellation patch
byte-for-byte, including the review repair, and all four unrelated
current master paths. The production retry logic remains unchanged from
this slice's reviewed implementation; the follow-up adds coverage and
its audit.
- **228 distinct complete cases pass:** all 48 run-control cases and all
180 native-session runtime cases. The two new targeted cases are
included in 48 and are not counted again. Server typechecking, build and
module-boundary checks also pass.
- The new real PostgreSQL cases reach a failed native run's correlated
Stop claim, cancellation fence, board handoff retirement and activity
write before raising `40P01`. One case preserves retry authority and
commits exactly one cancellation activity/live notice. The other changes
coordinator authority between attempts, returns 409, preserves the
failed run and handoff, and performs no provider/workspace cleanup.
- A negative control removes only the publication-list reset. It fails
with two live notices for one durable activity. Production was restored
byte-for-byte before final validation. The existing actual
two-connection deadlock, bounded attempts, non-deadlock rejection and
post-commit provider behavior remain covered.
- Preserve the initial new-assertion typecheck failure (optional
live-event payload) and the corrected final pass. Service-local test
files are typechecked; `src/__tests__` is excluded. The negative-control
harness initially expected an untruncated Vitest assertion line; the
actual named 1-versus-2 failure and restoration were inspected before
correcting its result matcher.
- [Current-parent acceptance and failure
ledger](https://github.com/paperclipai/paperclip/blob/60ba892ae9fc5faaf8cd0833694b4a66c13323c3/doc/plans/2026-10-28-cancellation-deadlock-acceptance.md)
records current scope, commands, isolated fixtures, mutation evidence
and limits. Earlier combined-stack counts retain their original revision
scope. The existing controlled runner timeout/late-append fixture is
retained and passes within the complete 180-case runtime suite.
- This addresses the prior Ponytail request to exercise native claimed
state before deadlock rollback and re-evaluate authority afterward. The
advisory loop-invariant snapshot/named-attempt-bound note remains a
maintainability suggestion, not a runtime defect. No production loop
refactor or new worker duty is introduced.
- **All 58 current checks are clean; Greptile and Ponytail both rate
this exact head 5/5.** Ponytail explicitly confirms that the
native-claim coverage request is resolved and says Ship. The formerly
queued dependency/quality review workflow has completed successfully.
Old `fffc`/parent checks and reviews are not current passes; the former
pending Snyk status is not called successful. Actual failing Ponytail
findings must be fixed. Missing/stopped/paused turns without a verdict
are authorized nonblockers. Active unfinished reviews retain their
original per-head timer, with a 25-minute monitor cutoff respecting the
30-minute maximum.
- No full local repository matrix, live provider execution, external
alarm, physical host/database suspension or savings claim is made. No
schema, dependency, workflow, shared scheduler contract or shared OS
resource changes are introduced.
## Risks
- Persistent contention still returns an error after the third attempt.
This change does not promise to eliminate every possible lock cycle.
- Retrying a write after an ambiguous connection failure would be
unsafe. The retry accepts only PostgreSQL's confirmed deadlock abort
code; it does not accept transport errors.
- No schema or public API contract changes. Current task/run authority
and cancellation eligibility are checked again on each attempt.
## Model Used
OpenAI GPT-6 via Codex, with shell, GitHub CLI, TypeScript, PostgreSQL,
and Playwright tools. The exact serving model ID and context window are
not exposed in this session.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
