The Scheduler that D4 was waiting on. Built against CORE's engine
HEADERS (now in main); the real EnginePort and the veloxd wiring wait
for lane/core's stage-8 bodies to reach main (deferrals.md D4a/D4b) —
core/src/task/ is still .gitkeep there, so linking vdm::Engine now
would be an unresolved symbol.
- sched/engine_port — the abstract seam: start/pause/resume/cancel/
provide_auth/decide/refresh_url + the ADR 0011 admission config
(set_task_order / set_max_active_segments / set_host_segment_cap).
Keeps the Scheduler testable without a live engine and the daemon
unbound from the concrete vdm::Engine.
- sched/fake_engine_port — a recording impl for tests.
- sched/scheduler:
* owns the wire-UUID <-> vdm::TaskId map.
* tick(): snapshot queues (schedule window evaluated with an
injectable clock) + non-terminal tasks -> governor.evaluate ->
apply. to_start builds a vdm::task::DownloadSpec from the row and
calls EnginePort::start; to_resume -> resume(); to_pause ->
pause() + writes the pause_reason; priority_order -> set_task_order
over the mapped engine ids. `new` tasks are parked (startMode
manual) and skipped.
* on_engine_state(wire_id, state, err): projects an engine
transition onto the store row (state, pause_reason='auto' when an
error rides a paused transition per ADR 0013 §2, flattened error
columns) so the next tick sees ground truth. This is also the hook
event.task.state will fire from (D5).
* reconcile_after_restart(): CORE-owned states -> queued, paused
keeps its reason (ADR 0013 §5).
* reload_config(): reads connection.maxConcurrentDownloads /
maxActiveSegments + a daemon-local host-cap map, pushes caps to
the engine, updates the governor.
* Deps: injectable local-now clock and a post_to_loop marshaller
(engine callbacks arrive on engine threads; default runs inline
for tests).
Test veloxd.sched_scheduler (ASan+UBSan and TSan clean): admission +
ordering, a slot freeing on completion, queue-stop -> pause
(queue_stopped) then queue-restart -> resume (not a fresh start),
engine auto-pause -> pause_reason 'auto' + never auto-resumed,
reconcile_after_restart, reload_config caps push. 35 daemon/cli tests
green.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Upd9WhG9oppieig5nRDLig
