# Description
Adopt
[`System.TimeProvider`](https://learn.microsoft.com/dotnet/api/system.timeprovider)
across the stack so that every place that creates timers, runs duration
math, or schedules periodic work is mockable, deterministic in tests,
and immune to wall-clock changes.
The migration touches Core, Core.Types, Server, Client, PubSub,
Configuration, Gds (server + client), Lds, and the Quickstarts/Console
reference apps. Per-component changes follow the same pattern:
1. Add a `private readonly TimeProvider m_timeProvider;` field.
2. Accept a nullable `TimeProvider? timeProvider = null` as the **last**
constructor parameter (new overload; legacy constructor stays for binary
compatibility and delegates with `timeProvider: null`).
3. Initialise the field with `m_timeProvider = timeProvider ??=
TimeProvider.System;`.
4. Replace `new Timer(...)`, `Stopwatch`, `HiResClock.*`,
`DateTime.UtcNow`-based duration math, and `Task.Delay(delay, ct)` in
timing loops with the matching `m_timeProvider` API (`CreateTimer`,
`GetTimestamp` / `GetElapsedTime`, `GetUtcNow().UtcDateTime`,
`Task.Delay(delay, m_timeProvider, ct)`).
5. Wire the provider through DI: `AddOpcUaServerBuilder` /
`AddOpcUaClientBuilder` register `TimeProvider.System` via
`TryAddSingleton<TimeProvider>()` so tests can swap in
`Microsoft.Extensions.Time.Testing.FakeTimeProvider`.
`HiResClock` itself is kept (so the
`ApplicationConfiguration.DisableHiResClock` schema flag still
round-trips), but **every public member** is now `[Obsolete]` with a
single shared message pointing to the new migration-guide section. The
few internal call sites that still need to set/read `HiResClock` are
wrapped with `#pragma warning disable CS0618`.
### Highlights per component
- **Core / Stack** — `Opc.Ua.Core`, `Opc.Ua.Core.Types`, channel
pipeline (`UaSCBinaryClientChannel`, `ChannelToken`,
`UaSCBinaryChannel`), `ApplicationConfiguration`, certificate
validators, `JwksIssuerKeyResolver`, `TimeProviderExtensions` polyfills
(`GetTimestampMilliseconds`, `GetTickCount`,
`CancellationTokenSource(timeout, timeProvider)`, `Task.Delay(delay,
provider, ct)` polyfill for older TFMs).
- **Server** — session lockout, subscription pipeline
(publish/sample/keep-alive/lifetime), `MonitoredItemQueue`, alarm
sampling rate, `IntervalRunner`, server diagnostics, configuration state
machines, hosted services.
- **Client** — `Session`, managed/V2 subscription engines, reconnect
handlers, channel keep-alive, periodic publishing, complex-type
discovery polling.
- **PubSub** — `IntervalRunner` pipeline, message-receive timers,
MQTT/UDP keep-alive, publishers/readers.
- **Gds / Lds** — `LdsServer`, `LinqApplicationsDatabase` expiry
housekeeping, GDS clients (push, pull), `DirectoryCertificateStore`,
`ConnectionStateMachine`, classic subscription engine.
- **Quickstarts / Console samples** — `SampleNodeManager`,
`ReferenceNodeManager`, `AlarmNodeManager`, `BoilerState`,
`MemoryBufferState`, `PublishedValuesWrites`. Samples resolve via
`(Server as ITimeProviderProvider)?.TimeProvider ?? TimeProvider.System`
so existing ctor signatures stay binary-compatible.
- **Tests** — `Opc.Ua.PubSub.Tests` adds `IntervalRunnerTests`; existing
`SubscriptionTests`, `UaPublisherTests`, and `TestDataSystem` move off
`HiResClock`. Added `Microsoft.Extensions.TimeProvider.Testing` package
for `FakeTimeProvider` (project-load warning surfaces on net48/net472
only — runtime is .NET 8+).
### Migration guide
New section [**Time and Timer abstraction
(`TimeProvider`)**](Docs/MigrationGuide.md#time-and-timer-abstraction-timeprovider)
documents:
- The canonical replacement table (`HiResClock.UtcNow` →
`timeProvider.GetUtcNow().UtcDateTime`, `HiResClock.TickCount64` →
`timeProvider.GetTimestamp()`, `new Timer` → `timeProvider.CreateTimer`,
`Task.Delay(delay, ct)` → `Task.Delay(delay, timeProvider, ct)`, …).
- The `TimeProvider? timeProvider = null` + `??=` constructor pattern.
- DI wiring and how to swap in `FakeTimeProvider` in tests.
- Before/after snippets for `HiResClock.TickCount64`,
`HiResClock.UtcNow`, and `new Timer(...)`.
## Related Issues
- Fixes#2458
## Checklist
- [x] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.
# Description
V2 subscription engine feature parity round to make the classic engine
eligible for deprecation. Splits the test surface so the classic and V2
engines can evolve independently, ports the gaps the classic-engine
integration tests had been exercising, and lands the public V2 API
additions needed to close them.
- Splits `Tests/Opc.Ua.Subscriptions.Tests` into a classic
(`Opc.Ua.Subscriptions.Classic.Tests`) and a V2
(`Opc.Ua.Subscriptions.Tests`) project to shrink CI time and let the two
engines diverge cleanly.
- Adds the V2 public-surface gaps required by the test ports
(`Subscription.ServerId` on the class, `SetSubscriptionDurableAsync`,
`SendInitialValuesOnTransfer`, unified `OnSubscriptionStateChangedAsync`
handler callback, per-item `ConditionRefreshAsync`, fluent
`LoadSubscriptionsAsync(Stream, …)` and `Subscription.Snapshot()` /
`RestoreAsync()` for save/load + transfer).
- Lands handler-centric design (no `PublishingStopped` property handlers
maintain derived state); always-sequential per-subscription delivery
documented + tested.
- **Adds short and long haul stability tests for the V2 `ManagedSession`
+ subscription engine. Closes #3744** (see "Issue #3744 Haul tests"
below).
- **Migrates SubscriptionStateSnapshot / MonitoredItemStateSnapshot to
`[DataType]` source-generator codecs**.
- `SubscriptionDurableV2Tests.cs` 5 V2 ports of the classic durable test
patterns.
- `V2FollowUpCoverageTests.cs` handler state-change callback, fluent
stream-based `LoadSubscriptionsAsync`, `SendInitialValuesOnTransfer`,
snapshot edge cases (empty / `DataChangeFilter` round-trip / concurrent
mutation).
- `SubscriptionFailoverV2Tests.cs` forced channel-break with and without
`WithTransferSubscriptionsOnRecreate`.
- `MonitoredItemConditionRefreshLiveV2Tests.cs` ΓÇö live
`ConditionRefresh` against the reference server's event source; asserts
`RefreshStart` / `RefreshEnd` events flow through the handler.
## Fixes
- #3744 Haul tests (V2 ManagedSession + subscription engine)
`Tests/Opc.Ua.Sessions.Tests/ManagedSessionStabilityTest.cs` adds the
short/long haul coverage requested by
[#3744](https://github.com/OPCFoundation/UA-.NETStandard/issues/3744)
plus the bonus fault-injection variant:
| Test | Duration | Category | Purpose |
|---|---|---|---|
| `ShortHaulManagedSessionV2Async` | 2 minutes | `ManagedSessionHaul`
(`[Explicit]`) | Quick local sanity check of the V2 monotonicity
contract. |
| `LongHaulManagedSessionV2Async` | 90 minutes (configurable via
`TEST_DURATION_MINUTES`) | `ManagedSessionHaul` (`[Explicit]`) |
Long-running V2 stability + monotonicity. |
| `LongHaulManagedSessionWithFaultInjectionV2Async` | 90 minutes
(configurable) + fault every `FAULT_INJECTION_INTERVAL_SECONDS` (default
60s) | `ManagedSessionHaul` (`[Explicit]`) | **Bonus** ΓÇö force-closes
the subscriber transport channel periodically; verifies V2 manager
transfers/recreates the subscription and continues monotonic delivery
across reconnects. |
**Pattern.** A writer `ManagedSession` increments a `uint32` counter and
writes it into `Scalar_Static_Mass_UInt32_UInt32_00` every 250ms. A
subscriber `ManagedSession` runs a V2 subscription with a single
monitored item on the same node. `MonotonicCounterHandler` asserts each
received sample is *strictly greater than* the previous one. V2
`ISubscriptionNotificationHandler` per-subscription ordering guarantee.
Skipped values (sampling rate < write rate) are tolerated; duplicates
and reorderings are violations.
* New certificate and secrete abstraction with certificate infrastructure and certificate/secret stores.
* leak testing for certificate resources to validate new ref counting in every test assembly
* Migration guide updated and documentation added for all
* Remove IDisposable from Nodestate and UserIdentity.
* UserCertificateTokenHandler now just points into certificate registry/stores, no dispose required
* Fix CA2000 warnings and cleanup of other diagnostics, increase warning levels in .editorconfig
- Add new managed session, wrapping session and providing connection management and failover handling
- Add new Subscription engine that can act as alternative to current engine, but is based on channels with worker tasks
- Add a fluent builder for managed session clients
- Replace NodeCache with LruNodeCache, rename ILruNodeCache and LruNodeCache to INodeCache and NodeCache
- Update migration guide and document new functionality.
This pull request modernizes the OPC UA .NET codebase and tests, removes .NET Standard 2.0 support from certificate/security code, and updates test code to use C# 12 and .NET 8+ features for clarity and maintainability.
- Certificate and BouncyCastle interop files (e.g., CertificateBuilder.cs, X509Extensions.cs, X509SignatureFactory.cs) are refactored to drop NETSTANDARD2_0 support and use modern .NET APIs and conditional compilation.
- Test code across the codebase is updated to use default, strongly-typed Parse methods, collection expressions, and improved async/await patterns.
- Exception handling and assertions in tests are modernized, and test method naming is made consistent with Async suffixes.
- The project and build files are updated to clarify Roslynator analyzer usage and remove obsolete netstandard tags.
- General code and test cleanup includes improved null safety, type safety, and removal of deprecated or unused code.
* Initial plan
* Add support for private encodeable factory in server initialization
- Add new ServiceMessageContext constructor that accepts a custom IEncodeableFactory
- Add CreateMessageContext(IEncodeableFactory) overload to ApplicationConfiguration
- Mark CreateMessageContext(bool) as obsolete since the clonedFactory parameter was never used
- Add PrivateEncodeableFactory property to ServerBase for specifying a private factory
- Update all internal calls to use the new parameterless CreateMessageContext()
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
* Add unit tests for ServiceMessageContext private factory support
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
* Improve documentation for ServiceMessageContext constructors
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
Marc Schier