The single-slot set_*_handler pattern was a structural blocker, hit twice:
the daemon could not observe control-state changes because
register_default_handlers owns the slot, forcing GetControlState to read the
FSM cross-thread (a data race), and blocking WatchHealth and the Subscribe
stream's ControlStateChange variant.
HandlerSlot<Args...> keeps a primary slot with exact legacy semantics
(set_ replaces — one existing test depends on replacement) plus an
append-only observer list (add_) that survives set_ calls. Fire sites are
textually unchanged (operator bool / operator() / assign-from-function).
Applied to ControlStateMachine + ProcessJobStore + ControlJobStore (the
roadmap-critical three; the remaining single-slot classes follow the same
3-line pattern as needed). EquipmentRuntime gains an atomic control-state
mirror registered as an observer — control_state() is now safe from any
thread, retiring the GetControlState race — plus add_control_state_observer
and add_link_observer (selected/closed fan-out), the hooks WatchHealth and
Subscribe need.
Tests: observer ordering, set-replaces-primary-but-observers-survive,
observers-without-primary, PJ-store coexistence, and the runtime scenario
that was previously impossible (mirror + observer + default-handlers set_).
Core 464/464 (2816 assertions), daemon 16/16, live GEM300 demo passes with
single-fire control-state transitions.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
GEM300 layer: SEMI E40-0705 Process Job and E94-0705 Control Job
state machines, plus the E30 §6.1 communication-state machine that
sits between HSMS SELECT and full GEM communication. Data-driven
via data/process_job_state.yaml and data/control_job_state.yaml,
mirroring the existing control_state.yaml pattern.
Wire coverage:
S14F9/F10 CreateObject (CJ) host -> equipment
S14F11/F12 DeleteObject (CJ) host -> equipment
S16F5/F6 PRJobCommand host -> equipment
S16F9 PRJobAlert equipment -> host
S16F11/F12 PRJobCreate (simplified body) host -> equipment
S16F13/F14 PRJobDequeue host -> equipment
S16F27/F28 CJobCommand host -> equipment
Process Job FSM exposes 8 states matching PRJOBSTATE bytes (E40 §10.3.2);
HOQ is reorder-aware (move-to-head against an insertion-order vector);
Stop/Abort on a Queued PJ routes through ABORTING so the host observes
PRJOBSTATE=7 on the wire (§6.3); alert_enabled is settable per-PJ for
PRALERT control; FSM dispatches through ProcessJobStore::on_change_
dynamically so a late set_state_change_handler() reaches existing PJs.
Hardening: loader rejects NoState (sentinel) as initial/from/to and
rejects `on: created` rows; static_asserts pin enum values to wire
bytes; ProcessJobStore is non-movable to keep the per-PJ this-capture
safe.
Server simulator cascades the full CJ -> PJ lifecycle on CJSTART so
the wire trace exercises every legal state. CEIDs 400/401 fire on CJ
state changes via the existing event-report pipeline.
Tests: 60+ new assertions across test_process_jobs, test_control_jobs,
test_communication_state, test_hsms_connection, plus loader and
messages round-trip coverage.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>