#519 — a driver's OPC UA status code now reaches a client with its sub-code intact.
DriverInstanceActor projected the driver's uint onto a 3-state Good/Uncertain/Bad enum
and OtOpcUaNodeManager re-expanded Bad to a bare 0x80000000, so BadNoCommunication,
BadTypeMismatch and BadNotSupported were indistinguishable on the wire and every
driver's status constants (incl. the 16 #497 had just corrected) were diagnostic in
logs only. Resolved by option (b): the raw uint rides AttributeValuePublished ->
AttributeValueUpdate -> IOpcUaAddressSpaceSink.WriteValue, OpcUaQuality is deleted, and
severity classification is a helper (OpcUaStatus.IsGood/IsUncertain/IsBad).
The surface was wider than the issue costed (41 files, not "the sink and 3
implementations"): OpcUaQuality had non-driver producers with no uint to carry.
Each got its natural code — BadInternalError for a failed virtual-tag script,
BadNoCommunication for driver comms loss — and ScriptedAlarmHostActor's pair of
mutually-inverse uint<->enum mappers is deleted, having round-tripped a code the
engine already held. AddressSpaceApplier's removal writes deliberately keep the
generic Bad: not losing a code the driver had is this issue; inventing one for the
deploy path is a separate call.
Behaviour change: WriteAlarmQuality fires its Part 9 event on a status-code change
rather than a severity-bucket change. While the annotation was 3-state those were the
same predicate; now a move between two Bad reasons changes what a subscriber reads.
New SDK-free named constants live on Commons.OpcUa.OpcUaStatus, and
StatusCodeParityTests is widened to cover them — that guard is reflection-driven, so
it can only see a named constant, never an inline literal.
#517 — the symptom is real but the issue named the wrong path and its fix was unsafe.
ShutdownAsync cannot race: DriverInstanceActor calls it from PostStop, after the
mailbox drains. (Core/Hosting/DriverHost, the one class with a concurrent GetHealth,
has no production call site.) InitializeAsync can: it runs on a fire-and-forget
Task.Run, and MTConnectDriver writes Healthy then starts loops that can throw into a
catch which disposes the client before writing Faulted.
Moving the write earlier, as suggested, inverts the terminal state — teardown drains
in-flight loops that write health as they unwind, so a late loop could leave Healthy at
rest with every connection closed. The fix is a bracket (conservative before, terminal
after), applied to MTConnect's init-failure path only; shutdown keeps its single
trailing write, and the rule plus the reachability table are documented on
IDriver.ShutdownAsync.
CalculationDriver.GetHealth returned a hard-coded Healthy that consulted nothing —
Healthy before initialize, after shutdown and after dispose. Now derived from _running.
Its test, named Health_is_always_Connected, asserted the defect and is replaced.
Every new guard was falsified by breaking the production code and watching it go red.
The two sub-code tests each assert two different Bad codes, since a single-code
assertion could pass against a hard-coded constant under the old projection.
Pre-existing failures, verified unchanged on a stashed tree and not chased: 4 in
Driver.AbLegacy.IntegrationTests (slc500/micrologix/plc5 fixtures not up) and 3 in
Host.IntegrationTests.
Closes#517Closes#519
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
Adds the Calculation pseudo-driver (tags computed by C# scripts over other tags' live
values) plus the host seam that feeds it:
- IDependencyConsumer capability interface (Core.Abstractions) + DriverTypeNames.Calculation.
- CalculationDriver : IDriver, ISubscribable, IReadable, IDependencyConsumer — change-gate +
dedupe (VirtualTagActor parity), timer-group scheduler, Bad-transition + script-log emission,
Good recovery; reuses the T0-4 CalculationEvaluator.
- DriverHostActor spawns a DependencyConsumerMuxAdapter per dependency-consuming driver,
registering its refs on the per-node DependencyMuxActor and forwarding DependencyValueChanged
→ OnDependencyValue; re-registers on every apply, torn down with the driver.
- Factory + probe registered in DriverFactoryBootstrap (keeps the T0-3 guard green); guard test
csproj references the driver so the bin-scan discovers the factory.
- DeploymentArtifact injects the resolved scriptSource (scriptId → SourceCode) into a calc tag's
delivered TagConfig so the host-blind driver can compile it.
- DraftValidator deploy gates: CalculationScriptMissing / CalculationScriptNotFound (scriptId
existence) + CalculationDependencyCycle (DependencyGraph.DetectCycles over calc→calc edges).
- Tests: driver units (dep-ref extraction, change-gate, dedupe, Bad+script-log+recovery, timer,
read), tag-config parsing, DraftValidator gates (self/2-cycle/cross-driver-terminal), and a
Runtime integration test proving values FLOW mux → adapter → driver → calc-of-calc end-to-end.
Claude-Session: https://claude.ai/code/session_01LVneM3eh1UtJxEisFXgmox
Joseph Doherty