Iter 25. Single-call operator surface: spawn() takes a BfldPipeline and
a Publish impl, returns a handle whose send() enqueues sensing inputs
into a worker thread. The worker drives pipeline.process() then
publish_event() per input. Drop or shutdown() joins cleanly.
Added (gated on `feature = "std"`):
- src/mqtt_topics.rs: impl<P: Publish> Publish for Arc<Mutex<P>>
Lets a publisher owned by a worker thread remain inspectable from a
test or operator post-shutdown.
- src/pipeline_handle.rs:
* PipelineInput { inputs: SensingInputs, embedding: Option<...> }
* BfldPipelineHandle { sender, worker: Option<JoinHandle<()>> }
* spawn<P: Publish + Send + 'static>(pipeline, publisher) -> Self
Worker loop: recv() → pipeline.process() → publish_event(); errors
logged to stderr (single-frame failures must not kill the loop)
* send(PipelineInput) -> Result<(), SendError<...>>
* shutdown(self) — replaces sender with a dropped channel so worker
recv() returns Err(RecvError); join propagates worker panics
* Drop impl mirrors shutdown so forgotten handles still clean up
- pub use BfldPipelineHandle, PipelineInput from lib.rs
tests/pipeline_handle_worker.rs (8 named tests, all green):
handle_publishes_single_input (5 topics for Anonymous + no zone)
handle_publishes_multiple_inputs_in_order (3 × 5 = 15 topics)
handle_send_after_shutdown_errors
(compile-time witness: shutdown(self) consumes the handle so
post-shutdown send() is structurally impossible)
handle_drop_without_explicit_shutdown_joins_worker_cleanly
(validates the Drop path completes without hanging)
handle_honors_privacy_mode_toggle_via_pipeline_state
(4 topics for Restricted; identity_risk absent)
handle_drops_event_when_gate_rejects
(5 topics from first Accept-state input + 0 from Reject)
handle_with_zone_threads_through_to_published_topics
(zone_activity payload = "\"kitchen\"")
class_3_pipeline_baseline_produces_four_topics_per_input
Test publisher pattern: Arc<Mutex<CapturePublisher>> lets the test thread
read out the worker thread's publish log post-shutdown without needing
custom channel plumbing per test.
ACs progressed:
- ADR-118 §2.1 lib.rs entry point now has the "set up MQTT and walk away"
operator surface promised in the implementation plan. Two lines:
let handle = BfldPipelineHandle::spawn(pipeline, rumqttc_pub);
handle.send(PipelineInput { inputs, embedding })?;
- ADR-122 §2.2 per-frame publish path is now structurally guarded by
worker-thread isolation: even if a Publish::publish call panics, only
the worker thread dies; the main thread sees a clean error on send().
Test config:
- cargo test --no-default-features → 72 passed
- cargo test → 177 passed (169 + 8)
- cargo test --features mqtt → 186 (178 + 8 — handle is std-only,
reachable in both feature configs)
Out of scope (next iter target):
- GitHub Actions workflow with mosquitto Docker service so the iter-24
integration test actually runs in CI with BFLD_MQTT_BROKER set.
- HA discovery payload publisher (ADR-122 §2.1) — the auto-discovery
config messages HA needs alongside the state topics this handle ships.
Co-Authored-By: claude-flow <ruv@ruv.net>