Two bugs caught by live verification against the mxaccessgw at 10.100.0.48:5120:
- MaxAttempts=1 produced an invalid Polly RetryStrategyOptions -> the probe failed
on every real gateway. Removed the Retry override (matches GalaxyDriver); fail-fast
is already guaranteed by the TCP preflight + the per-call deadline.
- A rejected key surfaces as a typed MxGatewayAuthenticationException, not a raw
RpcException, so 'auth-rejection = reachable' was bypassed. Catch the typed auth/
authorization exceptions -> Ok=true.
Adds DriverProbeHandshakeE2eTests: direct-probe, skip-gated cross-protocol green/red
discrimination (Modbus, OpcUaClient, Galaxy + a local real OPC UA server).
Replaces the bare-TCP AbLegacyDriverProbe with a two-phase probe:
Phase 1 is the existing TCP preflight; Phase 2 initialises a
LibplctagLegacyTagRuntime (Protocol.ab_eip + per-family PlcType) to
open a real PCCC-over-EIP session, using AbLegacyProbeOptions.ProbeAddress
("S:0") as the probe tag. Status-code discrimination mirrors the AbCip
probe: ErrorNotFound/ErrorNoMatch/ErrorBadDevice → Ok=true "controller
reachable"; transport errors → Ok=false "handshake failed".
Adds AbLegacyDriverProbeTests (5 unit tests, all green, 168 total).
Replace the bare-TCP-only AbCipDriverProbe with a two-phase check:
Phase 1 keeps the existing TCP preflight; Phase 2 initialises a
LibplctagTagRuntime against the first device to open a real EIP session
and CIP Forward Open, so a live-but-rejecting CIP endpoint reads red
instead of a false-positive green.
Status mapping: ErrorNotFound / ErrorNoMatch / ErrorBadDevice → reachable
(controller answered CIP, probe tag absent); ErrorTimeout / ErrorBadConnection
/ ErrorBadGateway / ErrorWinsock / ErrorOpen / ErrorClose / ErrorRead /
ErrorWrite / ErrorBadReply / ErrorRemoteErr / ErrorPartial / ErrorAbort →
handshake failed. LibPlcTagException message text is used as a secondary
signal for the reachable-exception path. All other statuses default to
handshake-failed (conservative).
Add AbCipDriverProbeTests: invalid JSON, no devices, malformed host address,
closed-port TCP rejection, and black-hole timeout — all offline-determinable.
Happy path + CIP-error path covered live against the CIP sim.
Replace the bare TCP-connect return in OpcUaClientDriverProbe with a real
OPC UA GetEndpoints discovery handshake (mirroring SelectMatchingEndpointAsync
in the driver). TCP preflight still fast-fails closed ports; the handshake
confirms the remote is actually an OPC UA server, so a live-but-rejecting
non-OPC-UA process now reads RED instead of a false-healthy green.
Replace bare TCP-connect with a two-phase probe: Phase 1 keeps the
existing SocketException / timeout / generic preflight paths unchanged;
Phase 2 runs Plc.OpenAsync (COTP CR/CC + S7 setup-communication) so a
device that accepts TCP but is not an S7 PLC reads red instead of green.
A linked CTS distinguishes caller cancellation ("timed out") from the
S7netplus internal read-timeout OCE ("handshake failed: timed out").
Replace the bare TCP-connect probe in ModbusDriverProbe with a two-phase
check: TCP connect via ModbusTcpTransport (keeps the same SocketException /
timeout / generic error paths and messages), then a one-shot FC03 Read
Holding Registers (qty 1 @ addr 0). A normal response → Ok=true "Modbus
FC03 OK"; a Modbus exception PDU → Ok=true "Modbus FC03 OK (device
returned exception PDU)"; any other failure after TCP succeeds → Ok=false
"Reachable at host:port but Modbus FC03 handshake failed: …".
Add ModbusDriverProbeTests (6 tests) covering invalid JSON, missing
host/port, closed port, TCP-accept-then-close, canned MBAP happy path,
and Modbus exception PDU path. All 277 Modbus tests green.
Add IFocasClientFactory.EnsureUsable() — a config-time probe called by
FocasDriver.InitializeAsync before any background loops start. The
UnimplementedFocasClientFactory throws NotSupportedException immediately
(faulting the driver at init), eliminating the footgun where a driver on
the 'unimplemented' backend appeared Healthy then failed every read/write/
subscribe silently. WireFocasClientFactory and FakeFocasClientFactory are
no-ops. Backstop Create() throw remains in place.
Make MapDataType internal, split the combined Int64/UInt64 arm to return
DriverDataType.Int64 and DriverDataType.UInt64 respectively, and remove
the now-stale Driver.Modbus-007 caveat doc block and inline comment.
Add a Theory covering both cases; full suite 271/271 green.
The owning DriverInstanceActor re-subscribes alarms on every Connected
entry (DetachAlarmSource nulls its cached handle on Connected->Reconnecting
without calling UnsubscribeAlarmsAsync), and the driver object + its alarm
projection are reused across every in-place reconnect. Each SubscribeAsync
started a fresh, never-cancelled Task.Run poll loop and added it to _subs,
so N reconnects leaked N concurrent loops all polling the device and all
firing the same raise/clear transitions => duplicate alarm events + CPU/mem
growth.
Mirrors the Galaxy #399 fix (Clear-before-Add) but for live poll loops the
collapse must also CANCEL the superseded loops, not just drop references.
SubscribeAsync now snapshots existing subs under _subsLock, clears _subs,
adds the new sub, starts its loop, then retires each stale sub out-of-band
(RetireAsync: Cancel + await loop + Dispose CTS, fire-and-forget so the new
subscription's return isn't blocked on a poll interval). Snapshot+clear under
the same lock DisposeAsync uses guarantees no double-own / double-dispose.
There is exactly one consumer per driver instance (factory-per-actor), so
retiring all prior subscriptions before starting the new one is faithful.
Regression tests (TDD, fail->pass): subscribe twice then drive one device
raise; assert OnAlarmEvent fires exactly once (was twice with two leaked
loops).
GalaxyDriver's StreamAlarms feed is session-less and survives an in-place
reconnect, so DriverInstanceActor re-subscribed on every Connected re-entry
(after dropping its own cached handle without an Unsubscribe — sync teardown).
The re-subscribe was additive: _alarmSubscriptions.Add grew the list by one
untracked handle per reconnect cycle — a slow unbounded leak. Functionally
harmless (the gate is Count>0 and OnAlarmFeedTransition only reads [0], firing
once regardless), but it accumulated forever.
Fix: SubscribeAlarmsAsync clears the set before adding, collapsing to a single
live handle (under the existing _alarmHandlersLock, atomic w.r.t. the fan-out
reader). There is exactly one consumer per driver instance (factory-per-actor
lifecycle), so replacing the set with the latest handle is faithful. Chosen
over making the actor's sync DetachAlarmSource call UnsubscribeAlarmsAsync
async/fire-and-forget — disproportionate for a minor leak.
Regression test Re_subscribe_collapses_to_a_single_handle_no_accumulation
(TDD-verified: FAILS without the Clear — releasing the latest handle leaves
the feed open because stale handles remain; PASSES with the fix). Galaxy tests
263 pass / 3 skip; Runtime native-alarm 24 pass. Code-reviewed (approved).
Joseph Doherty