Files
alkhttp/tasks/websocket/review-001-ws-eof-signal.md
T
glm-5.3-flash 8e8e1f2b14 refactor(gateway): migrate to alkcall 0.2 promoted gateway module
Bump the alkcall dependency to 0.2 (with the gateway feature) and
converge on the promoted shared pieces:

- The local dispatch spine (gateway/dispatch.rs, 721 lines) is deleted;
  GatewayDispatch, schema_disclosure_denial, and DEFAULT_DEADLINE are
  re-exported from alkcall::gateway (alkcall ADR-048). The 30 s default
  deadline preserves the previous behavior exactly.
- gateway/schema_cache.rs (PublishSchemaCache) is deleted: alkcall CF-003
  compiles publish_schema at registration time and exposes
  OperationRegistry::publish_validator; the /publish chunk stream
  resolves against it. Un-compilable schemas are now rejected at
  registration, so the two end-to-end fail-closed tests were reworked
  into a registration-rejection test (a stronger guarantee).
- schema_disclosure_denial consumers (to_mcp, routes) use alkcall's
  promoted implementation; the alkhttp-local copy is gone (ADR-071
  updated: the guard stays as defense-in-depth, the implementation no
  longer forks).
- CF-001: from_wss drop monitor and the WS overlay tests use
  CallError::connection_closed; the review-001-ws-eof-signal race tests
  now assert retryable CONNECTION_CLOSED on both resolution paths (the
  tolerated non-retryable INTERNAL write-failure outcome is gone).
- Added CHANGELOG.md (Keep a Changelog), Unreleased section records the
  bump and convergence.

Verification: cargo test default 453 ok, wss 470 ok, mcp 526 ok,
all-features 575 ok; clippy -D warnings clean (default + all-features,
all-targets); fmt clean; cargo doc warning-free.

Net: -1093 lines.
2026-08-31 10:36:32 +00:00

97 lines
4.6 KiB
Markdown

---
id: review-001-ws-eof-signal
name: Lossless EOF signal + pending-map sweep for from_wss (WS-02, CON-02)
status: completed
depends_on: []
scope: narrow
risk: high
impact: component
level: implementation
tags: [websocket, adapters, review-001, from-wss]
---
## Description
Review 001 findings WS-02 + CON-02 — one mechanism, verified end-to-end:
`src/websocket/byte_adapter.rs:138-139` (and the tungstenite twin at
`:319`) fires `read_eof.notify_waiters()`, which wakes only
*already-registered* waiters and stores no permit. `from_wss` spawns its
drop-monitor *after* session setup (`from_wss.rs:156-166`); if the read
task hits EOF before the monitor first polls `Notified`, the signal is
lost. `import()` does `std::mem::forget(session)` (`:193`), so the
`close_rx` fallback never fires either — the monitor never runs
`fail_all`, and in-flight imported-op calls hang (Once-calls recover only
at the 30 s sweeper *if* a sweeper runs; CON-02 establishes it doesn't on
this path — `Dispatcher::run_loop`'s sweeper is never taken; `Sub`/`Pub`
pendings hang forever). The module doc at `from_wss.rs:111-113` promises
the opposite of the behavior.
Fix both halves:
- Replace `notify_waiters` with a permit-storing signal: `tokio::sync::watch`,
`CancellationToken`, or a checked `AtomicBool` — anything a late
subscriber observes. Apply to both the axum and tungstenite pump paths.
- Extend the from_wss monitor to sweep the pending map periodically while
the session lives (or otherwise ensure post-`fail_all` registrations
still resolve), since calls registered after the one-shot `fail_all`
are currently never resolved.
Acceptance gates from the review: (1) a from_wss test that drops the
connection **while a call is being registered** — the CON-02 race — with
no hang; (2) the module doc's promise ("no hang") becomes true.
## Acceptance Criteria
- [x] EOF-notify is stored (late subscriber observes it) — race test: drop during session setup/first call registration resolves all in-flight calls as retryable
- [x] Post-`fail_all`-registered pendings also resolve (sweep or equivalent), not hang forever
- [x] The `connection_drop_fails_in_flight_calls_retryable_no_hang` test remains green; add the racing-drop variant (COV gap 10)
- [x] Module doc at `from_wss.rs:111-113` matches implemented behavior
- [x] `cargo test` and `cargo clippy --all-targets -- -D warnings` pass
## References
- docs/reviews/001-initial-implementation-review.md (Part B, WS-02; Part G, CON-02; COV-03)
- docs/architecture/decisions/070-from-wss-consumer-adapter.md
## Notes
> Agent fills during implementation. Highest-priority WS fix — lossy
> notification hangs calls; everything else in the WS subsystem can
> follow.
## Summary
Replaced the `Notify`-based read-EOF signal in `WsPumps` (both axum and
tungstenite pump paths in `byte_adapter.rs`) with a retained
`tokio::sync::watch` channel (`Sender<bool>`/`subscribe()` receiver) —
the lossless EOF property WS-02 required. The `from_wss` drop monitor
now selects on `eof_rx.changed()` / `close_rx` / a 1 s sweep tick: on
EOF it fails all pendings with retryable `CONNECTION_CLOSED` and keeps
sweeping every tick so calls registered *after* the initial `fail_all`
(the `std::mem::forget` fire-and-forget import path) are also failed —
the CON-02 no-hang guarantee, independent of registration-vs-EOF
ordering. `std::mem::forget` semantics were left untouched per the task
scope.
Tests (in `from_wss.rs` `mod tests`): a killable producer harness
(`drop_on_signal_producer` — the upgrade handler stashes the server
side's `WsPumps` in a slot the test can `abort()`, forcing consumer-side
EOF deterministically); `forget_session_drop_during_call_registration…`
and `held_session_drop_during_call_registration…` cover the CON-02 race
(EOF before/during registration → call resolves Err, no hang); the
`call_registered_after_eof…` test registers a call well after EOF and
asserts the sweep resolves it retryable; the original
`connection_drop_fails_in_flight_calls_retryable_no_hang` stays green.
One tolerated outcome note: the held-session race can also resolve via
alkcall's write-failure path — since alkcall CF-001 landed
(`CallError::connection_closed`), that path now resolves
retryable `CONNECTION_CLOSED` too, so the race tests assert
retryable-only (updated in the alkcall-0.2 bump; the retryable
assertion no longer needs the sweep-test carve-out).
Verification: cargo test 219 ok; cargo test --features wss 231 ok (3x
flake check); cargo clippy --all-targets -- -D warnings (default;
all-features blocked only by an unrelated in-flight
`src/server/adapter.rs` edit from a parallel agent);
cargo fmt --check.