Files
Joseph Doherty
6c5b202910
TwinCAT follow-up — Native ADS notifications for ISubscribable. Closes task #189 — upgrades TwinCATDriver's subscription path from polling (shared PollGroupEngine) to native AdsClient.AddDeviceNotificationExAsync so the PLC pushes changes on its own cycle rather than the driver polling. Strictly better for latency + CPU — TC2 and TC3 runtimes notify on value change with sub-millisecond latency from the PLC cycle. ITwinCATClient gains AddNotificationAsync — takes symbolPath + TwinCATDataType + optional bitIndex + cycleTime + onChange callback + CancellationToken; returns an ITwinCATNotificationHandle whose Dispose tears the notification down on the wire. Bit-within-word reads supported — the parent word value arrives via the notification, driver extracts the bit before invoking the callback (same ExtractBit path as the read surface from PR 2). AdsTwinCATClient — subscribes to AdsClient.AdsNotificationEx in the ctor, maintains a ConcurrentDictionary<uint, NotificationRegistration> keyed on the server-side notification handle. AddDeviceNotificationExAsync returns Task<ResultHandle> with Handle + ErrorCode; non-NoError throws InvalidOperationException so the driver can catch + retry. Notification event args carry Handle + Value + DataType; lookup in _notifications dict routes the value through any bit-extraction + calls the consumer callback. Consumer-side exceptions are swallowed so a misbehaving callback can't crash the ADS notification thread. Dispose unsubscribes from AdsNotificationEx + clears the dict + disposes AdsClient. NotificationRegistration is ITwinCATNotificationHandle — Dispose fires DeleteDeviceNotificationAsync as fire-and-forget with CancellationToken.None (caller has already committed to teardown; blocking would slow shutdown). TwinCATDriverOptions.UseNativeNotifications — new bool, default true. When true the driver uses native notifications; when false it falls through to the shared PollGroupEngine (same semantics as other libplctag-backed drivers, also a safety valve for targets with notification limits). TwinCATDriver.SubscribeAsync dual-path — if UseNativeNotifications false delegate into _poll.Subscribe (unchanged behavior from PR 3). If true, iterate fullReferences, resolve each to its device's client via EnsureConnectedAsync (reuses PR 2's per-device connection cache), parse the SymbolPath via TwinCATSymbolPath (preserves bit-in-word support), call ITwinCATClient.AddNotificationAsync with a closure over the FullReference (not the ADS symbol — OPC UA subscribers addressed the driver-side name). Per-registration callback bridges (_, value) → OnDataChange event with a fresh DataValueSnapshot (Good status, current UtcNow timestamps). Any mid-registration failure triggers a try/catch that disposes every already-registered handle before rethrowing, keeping the driver in a clean never-existed state rather than half-registered. UnsubscribeAsync dispatches on handle type — NativeSubscriptionHandle disposes all its cached ITwinCATNotificationHandles; anything else delegates to _poll.Unsubscribe for the poll fallback. ShutdownAsync tears down native subs first (so AdsClient-level cleanup happens before the client itself disposes), then PollGroupEngine, then per-device probe CTS + client. NativeSubscriptionHandle DiagnosticId prefixes with twincat-native-sub- so Admin UI + logs can distinguish the paths. 9 new unit tests in TwinCATNativeNotificationTests — native subscribe registers one notification per tag, pushed value via FireNotification fires OnDataChange with the right FullReference (driver-side, not ADS symbol), unsubscribe disposes all notifications, unsubscribe halts future notifications, partial-failure cleanup via FailAfterNAddsFake (first succeeds, second throws → first gets torn down + Notifications count returns to 0 + AddCallCount=2 proving the test actually exercised both calls), shutdown disposes subscriptions, poll fallback works when UseNativeNotifications=false (no native handles created + initial-data push still fires), handle DiagnosticId distinguishes native vs poll. Existing poll-mode ISubscribable tests in TwinCATCapabilityTests updated with UseNativeNotifications=false so they continue testing the poll path specifically — both poll + native paths have test coverage now. TwinCATDriverTests got Probe.Enabled=false added because the default factory creates a real AdsClient which was flakily affected by parallel test execution sharing AMS router state. Total TwinCAT unit tests now 93/93 passing (+8 from PR 3's 85 counting the new native tests + 2 existing tests that got options tweaks). Full solution builds 0 errors; Modbus / AbCip / AbLegacy / other drivers untouched. TwinCAT driver is now feature-complete end-to-end — read / write / discover / native-subscribe / probe / host-resolve, with poll-mode as a safety valve. Unblocks closing task #120 for TwinCAT; remaining sub-task: FOCAS + task #188 (symbol-browsing — lower priority than FOCAS since real config flows still use pre-declared tags).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
AB Legacy PR 3 — ITagDiscovery + ISubscribable + IHostConnectivityProbe + IPerCallHostResolver. Fills out the AbLegacy capability surface — the driver now implements the same 7-interface set as AbCip (IDriver + IReadable + IWritable + ITagDiscovery + ISubscribable + IHostConnectivityProbe + IPerCallHostResolver). ITagDiscovery emits pre-declared tags under an AbLegacy root folder with a per-device sub-folder keyed on HostAddress (DeviceName fallback to HostAddress when null). Writable tags surface as SecurityClassification.Operate, non-writable as ViewOnly. No controller-side enumeration — PCCC has no @tags equivalent on SLC / MicroLogix / PLC-5 (symbol table isn't exposed the way Logix exposes it), so the pre-declared path is the only discovery mechanism. ISubscribable consumes the shared PollGroupEngine extracted in AB CIP PR 1 — reader delegate points at ReadAsync (already handles lazy runtime init + caching), onChange bridges into the driver's OnDataChange event. 100ms interval floor. Initial-data push on first poll. Makes AbLegacy the third consumer of PollGroupEngine (after Modbus and AbCip). IHostConnectivityProbe — per-device probe loop when ProbeOptions.Enabled + ProbeAddress configured (defaults to S:0 status file word 0). Lazy-init on first tick, re-init on wire failure (destroyed native handle gets recreated rather than silently staying broken). Success transitions device to Running, exception to Stopped, same-state spurious event guard under per-device lock. GetHostStatuses returns one entry per device with current state + last-change timestamp for Admin /hosts surfacing. IPerCallHostResolver maps tag full-ref → DeviceHostAddress for the Phase 6.1 (DriverInstanceId, ResolvedHostName) bulkhead/breaker keying per plan decision #144. Unknown refs fall back to first device's address (invoker handles at capability level as BadNodeIdUnknown); no devices → DriverInstanceId. ShutdownAsync cancels + disposes each probe CTS, disposes PollGroupEngine cancelling active subscriptions, disposes every cached runtime. DeviceState gains ProbeLock / HostState / HostStateChangedUtc / ProbeCts / ProbeInitialized matching AbCip's DeviceState shape. 10 new unit tests in AbLegacyCapabilityTests covering — pre-declared tags emit under AbLegacy/device folder with correct SecurityClassification, subscription initial poll raises OnDataChange with correct value, unsubscribe halts polling (value change post-unsub produces no further events), GetHostStatuses returns one entry per device, probe Running transition on successful read, probe Stopped transition on read exception, probe disabled when ProbeAddress null, ResolveHost returns declared device for known tag, falls back to first device for unknown, falls back to DriverInstanceId when no devices. Total AbLegacy unit tests now 92/92 passing (+10 from PR 2's 82); full solution builds 0 errors; AbCip + Modbus + other drivers untouched. AB Legacy driver now complete end-to-end — SLC 500 / MicroLogix / PLC-5 / LogixPccc all shippable with read / write / discovery / subscribe / probe / host-resolve, feature-parity with AbCip minus IAlarmSource (same deferral per plan).
TwinCAT follow-up — Native ADS notifications for ISubscribable. Closes task #189 — upgrades TwinCATDriver's subscription path from polling (shared PollGroupEngine) to native AdsClient.AddDeviceNotificationExAsync so the PLC pushes changes on its own cycle rather than the driver polling. Strictly better for latency + CPU — TC2 and TC3 runtimes notify on value change with sub-millisecond latency from the PLC cycle. ITwinCATClient gains AddNotificationAsync — takes symbolPath + TwinCATDataType + optional bitIndex + cycleTime + onChange callback + CancellationToken; returns an ITwinCATNotificationHandle whose Dispose tears the notification down on the wire. Bit-within-word reads supported — the parent word value arrives via the notification, driver extracts the bit before invoking the callback (same ExtractBit path as the read surface from PR 2). AdsTwinCATClient — subscribes to AdsClient.AdsNotificationEx in the ctor, maintains a ConcurrentDictionary<uint, NotificationRegistration> keyed on the server-side notification handle. AddDeviceNotificationExAsync returns Task<ResultHandle> with Handle + ErrorCode; non-NoError throws InvalidOperationException so the driver can catch + retry. Notification event args carry Handle + Value + DataType; lookup in _notifications dict routes the value through any bit-extraction + calls the consumer callback. Consumer-side exceptions are swallowed so a misbehaving callback can't crash the ADS notification thread. Dispose unsubscribes from AdsNotificationEx + clears the dict + disposes AdsClient. NotificationRegistration is ITwinCATNotificationHandle — Dispose fires DeleteDeviceNotificationAsync as fire-and-forget with CancellationToken.None (caller has already committed to teardown; blocking would slow shutdown). TwinCATDriverOptions.UseNativeNotifications — new bool, default true. When true the driver uses native notifications; when false it falls through to the shared PollGroupEngine (same semantics as other libplctag-backed drivers, also a safety valve for targets with notification limits). TwinCATDriver.SubscribeAsync dual-path — if UseNativeNotifications false delegate into _poll.Subscribe (unchanged behavior from PR 3). If true, iterate fullReferences, resolve each to its device's client via EnsureConnectedAsync (reuses PR 2's per-device connection cache), parse the SymbolPath via TwinCATSymbolPath (preserves bit-in-word support), call ITwinCATClient.AddNotificationAsync with a closure over the FullReference (not the ADS symbol — OPC UA subscribers addressed the driver-side name). Per-registration callback bridges (_, value) → OnDataChange event with a fresh DataValueSnapshot (Good status, current UtcNow timestamps). Any mid-registration failure triggers a try/catch that disposes every already-registered handle before rethrowing, keeping the driver in a clean never-existed state rather than half-registered. UnsubscribeAsync dispatches on handle type — NativeSubscriptionHandle disposes all its cached ITwinCATNotificationHandles; anything else delegates to _poll.Unsubscribe for the poll fallback. ShutdownAsync tears down native subs first (so AdsClient-level cleanup happens before the client itself disposes), then PollGroupEngine, then per-device probe CTS + client. NativeSubscriptionHandle DiagnosticId prefixes with twincat-native-sub- so Admin UI + logs can distinguish the paths. 9 new unit tests in TwinCATNativeNotificationTests — native subscribe registers one notification per tag, pushed value via FireNotification fires OnDataChange with the right FullReference (driver-side, not ADS symbol), unsubscribe disposes all notifications, unsubscribe halts future notifications, partial-failure cleanup via FailAfterNAddsFake (first succeeds, second throws → first gets torn down + Notifications count returns to 0 + AddCallCount=2 proving the test actually exercised both calls), shutdown disposes subscriptions, poll fallback works when UseNativeNotifications=false (no native handles created + initial-data push still fires), handle DiagnosticId distinguishes native vs poll. Existing poll-mode ISubscribable tests in TwinCATCapabilityTests updated with UseNativeNotifications=false so they continue testing the poll path specifically — both poll + native paths have test coverage now. TwinCATDriverTests got Probe.Enabled=false added because the default factory creates a real AdsClient which was flakily affected by parallel test execution sharing AMS router state. Total TwinCAT unit tests now 93/93 passing (+8 from PR 3's 85 counting the new native tests + 2 existing tests that got options tweaks). Full solution builds 0 errors; Modbus / AbCip / AbLegacy / other drivers untouched. TwinCAT driver is now feature-complete end-to-end — read / write / discover / native-subscribe / probe / host-resolve, with poll-mode as a safety valve. Unblocks closing task #120 for TwinCAT; remaining sub-task: FOCAS + task #188 (symbol-browsing — lower priority than FOCAS since real config flows still use pre-declared tags).