Files
codex/codex-rs/thread-store
Owen Lin 5c94796dc9 Enforce single-writer ownership for paginated threads (#34986)
## Why

Only one app-server process should keep a paginated thread open for writing at
a time, while other processes must still be able to read it.

## What changed

- Acquire a per-thread filesystem lock when creating or resuming a paginated
  thread, and retain it for the lifetime of the live recorder.
- Reject a competing `thread/resume` request with JSON-RPC error `-32600` and
  release ownership when the writer is discarded, deleted, or shut down.
- Remove stale lock files without disturbing active writers.

## Testing

Added coverage for competing processes, ownership transfer after shutdown,
stale-lock cleanup, and lock release during discard and deletion.

GitOrigin-RevId: 81d49a2fffc73ba8135752b4944f27feafa4c0d6
2026-07-23 18:22:41 +00:00
..
2026-04-14 13:51:00 -07:00

Thread Store

codex-thread-store is the storage boundary for Codex threads. It defines the ThreadStore trait plus local and in-memory implementations. Other storage implementations may live outside this repository.

Responsibilities

  • ThreadStore::append_items is the raw canonical history append API. It does not infer metadata from item contents.
  • ThreadStore::update_thread_metadata is the only thread metadata write API. It accepts a single literal metadata patch shape, regardless of whether the caller is applying a user/API mutation or facts derived above the store from appended history.
  • LiveThread is the preferred API for active session persistence. It owns a per-thread metadata sync helper, applies the rollout persistence policy, appends canonical history, and then sends metadata patches through ThreadStore::update_thread_metadata.
  • ThreadManager routes metadata mutations for loaded and cold threads through one entrypoint. Loaded threads use their LiveThread; cold threads go directly to the store.
  • LocalThreadStore persists history through codex-rollout JSONL files and persists queryable metadata through the SQLite state database when available. Local explicit metadata mutations also maintain JSONL/name-index compatibility so reading old or SQLite-less local storage keeps working.
  • RolloutRecorder is the local JSONL writer. It writes already-canonical items for ThreadStore::append_items; it no longer decides metadata updates for live thread-store appends.
  • core/session creates or resumes LiveThread handles and does not need to know whether persistence is backed by local files or another store.

Direction

New metadata observation semantics should live above ThreadStore. Stores persist explicit metadata fields, but raw history appends remain history-only.