Files
alktunnels/tasks/tunnels/consumer-session.md
T
glm-5.3-flash 69498b79cc tasks: Phase 2 decomposition — 12-task dependency graph for v1
tasks/architecture/:
- oq-promotion-sync (planning): back-pointers from the phase-0 ledger
  + AGENTS.md to the promoted OQ tracker (the convergence checklist's
  final half)
- oq-tn-14-tracker: the Safe-Exit external-trigger tracker task for
  OQ-TN-14 (unix/stdio placement; [external-trigger, deferred-oq],
  risk trivial, level research per the two-halves rule)

tasks/tunnels/ (the implementation graph, 8 generations):
- crate-init: module skeleton per overview.md's module map
- params: TunnelParams + open-op spec (ADR-001 wire-stable surface)
- wire-codec: frame_datagram/DatagramReader + the 8 POC-pinned test
  families (ADR-003)
- producer-open-op: establisher (dial, plan flow R-01) + pump handler
  (pump_bidi inline R-02) + registration; POC-ported integration tests
- consumer-session: TunnelSession (open/adopt, data planes, teardown
  matrix — ADR-005); generalizes the reverse POC's ReverseTunnel
- producer-listen: the listen establisher + AcceptQueue contract
  (ADR-004 shape 2)
- local-socket-halves: the local feature (TCP/UDP/unix halves
  functions; truncation fail-loud per OQ-TN-13; unix ships per
  OQ-TN-14's lean-yes, stdio deferred)
- review-core-crates: review-injection point before the downstream
  tasks build on the high-risk producer/consumer shapes
- end-to-end-suite: 6 suites / >=20 tests consolidating both POC
  suites against the public API (the spec's executable form)
- review-impl: the phase-gate review (wire/API/conventions/docs sync;
  findings doc per the alkhttp/alkcall house pattern)

Graph verified with taskgraph: 12 tasks valid, no cycles, 8
generations; critical path = oq-promotion-sync -> crate-init ->
params -> wire-codec -> producer-open-op -> consumer-session ->
review-core-crates -> review-impl; risk concentrated in the two
session tasks (both POC-validated); parallel groups available at
generations 1 and 6
2026-09-07 19:07:20 +00:00

4.2 KiB

id, name, status, depends_on, scope, risk, impact, level, tags
id name status depends_on scope risk impact level tags
tunnels/consumer-session Consumer half — TunnelSession (open/adopt, data planes, teardown) pending
tunnels/params
tunnels/wire-codec
tunnels/producer-open-op
broad high phase implementation
consumer
session
teardown

Description

Implement src/consumer.rs per consumer.md + ADR-005: TunnelSession — the typed client, both construction paths, the substrate-shaped data plane, and teardown ownership. The reverse POC's consumer (/workspace/alktunnels-reverse-poc/src/consumer.rsReverseTunnel) is the seed; this task generalizes it to the spec's session type.

Construction

  • Forward path: TunnelSession::open(client: &ChannelClient, params: TunnelParams) -> Result<Self, TunnelOpenError>client.open_channel(OP_TUNNEL_OPEN, params, TUNNEL_ALPN) → adopt → split the channel BiStream → data plane by substrate. Typed errors (ADR-049 §4; never a phantom session).
  • Reverse path: TunnelSession::adopt(manager: &ChannelManager, channel_id: u32, alpn: impl Into<String>) -> Result<Self, TunnelOpenError> — adopt a worker-allocated ID (early arrivals parked), install the data plane from the adopted halves. open_reverse_channel(hub_call, params, auth_token) -> Result<u32, ReverseOpenError> as the free function the assembly layer calls before adopt (the POC's shape — the hub's call surface is a CallConnection, not a ChannelClient, so the two-step is the honest API).

Data plane

  • Stream variant: stream_halves()(&mut dyn AsyncRead, &mut dyn AsyncWrite) (borrowed access); take_halves(self) → owned boxed halves (the session's halves ARE the tunnel — raw pass-through).
  • Datagram variant: send_datagram(&[u8]) -> Result<(), TunnelIoError> (frame → write → flush; Oversize >65535); recv_datagram() -> Result<Option<Bytes>, TunnelIoError>Some(bytes) per datagram (possibly empty, len=0 legal), None only on stream EOF (the F-2 layering; the POC's read_one_datagram incremental loop).
  • Wrong-substrate operations are WrongSubstrate errors (the POC's shape).

Pump ownership + teardown (ADR-005 — the point)

  • pump_against(self, accepted: impl AsyncRead + AsyncWrite + ...) — for the reverse path: spawn pump_bidi(channel_bistream, accepted_read, accepted_write), hold the returned handle. Returns the session (builder-style) or takes self and returns the handle — pick the shape that makes holding easy; document it.
  • close(self) -> bool — abort the pump (if session-owned) + teardown_channel (ungraceful path).
  • join(self) -> (u64, u64, bool) — await pump completion, then reap; copy counts for observability. Pump-less sessions (after take_halves): completes immediately, reaps only, (0, 0, reaped) (consumer.md's pinned semantics).
  • Drop — abort + sync teardown_channel (best-effort; never leak the entry). No Clone.

Tests

Extend the producer task's integration suite: forward open (session halves drive a duplex), reverse open+adopt+pump_against (the POC's ReverseTunnel tests: round-trip, half-close W4, join_and_reap copy counts, out-of-band close + self-reaping, pump-less join), datagram variant (round-trip incl. empty datagram via the codec), teardown matrix (close/join/Drop paths — no leaked channel entries asserted via channel_ids()).

Acceptance Criteria

  • open + adopt construction both present; typed error surfaces exact
  • stream_halves/take_halves/send_datagram/recv_datagram per consumer.md
  • Teardown matrix: close (ungraceful), join (graceful + copy counts), pump-less join (0, 0, reaped), Drop (no leak)
  • Half-close semantics test (W4's shape) passes
  • No Clone on TunnelSession (compile-asserted)
  • Clippy/fmt clean; wasm32 check passes; cargo test green

References

  • docs/architecture/consumer.md (the normative API)
  • docs/architecture/decisions/005-consumer-session-owns-teardown.md
  • POC reference: /workspace/alktunnels-reverse-poc/src/consumer.rs (the seed shape to generalize)

Notes

Agent fills during implementation.

Summary

Agent fills this on completion.