mirror of
https://github.com/OPCFoundation/UA-.NETStandard.git
synced 2026-10-29 15:11:53 +08:00
romanettandMarc Schier
805398942a
* Allow to register IAsyncNodeMangers, Add SyncNodeManager Adapter. * Add RemoveNamespaceMananager(IASyncNodeManager) * Allow AsyncNodeManagers in ReferenceServer * Add documentation * Create real sync GetManagerHandle implementation --------- Co-authored-by: Marc Schier <marcschier@users.noreply.github.com>
50 lines
3.9 KiB
Markdown
50 lines
3.9 KiB
Markdown
# Support of the TAP (Task Asynchronous Pattern) for server operations
|
|
|
|
The OPC UA .NET Standard stack has supported asynchronous operations for a long time. The asynchronous operations are based on the IAsyncResult pattern, which is also called the APM (Asynchronous Programming Model) or the Begin/End pattern. This pattern was introduced with .NET Framework 1.0 and is still supported in .NET 8.0.
|
|
|
|
In addition to the APM, the TAP (Task Asynchronous Pattern) is now also supported for server operations. The TAP is based on the Task and async/await keywords introduced in .NET Framework 4.0 and is the recommended way to implement asynchronous operations in modern .NET applications.
|
|
|
|
In the future APM support will be deprecated, as it was never implemented for NodeManagers.
|
|
|
|
Starting with 1.5.378 the server library allows users to also implement Task based NodeManagers.
|
|
Implementing the TAP allows to improve the scalability of the server, as the TAP is significantly more efficient in terms of resource usage and performance.
|
|
|
|
In order to support the TAP pattern, the following changes have been made to the server library:
|
|
|
|
- Introduce a Task based `RequestQueue`
|
|
- Introduce a Task based `TransportListenerCallback`
|
|
- Update the generated Code to support Task based operations
|
|
- Update of the `MasterNodeManager` to support Task based operations
|
|
- Introduce a Task based `IAsyncNodeManager` interface
|
|
- Introduce `AsyncNodeManagerAdapter` and `SyncNodeManagerAdapter` classes to support sync and async node managers side by side.
|
|
|
|
## Upgrading an existing server
|
|
|
|
- Update `INodeManager.CreateMonitoredItems` to support the new `MonitoredItemIdFactory`.
|
|
- In a future release an `CustomNodeManagerAsync` class will be provided to simplify the creation of fully async NodeManagers.
|
|
- The existing `CustomNodeManager2` class can be used as is, and async operations can be implemented as needed using the different interfaces provided by the server library:
|
|
- `IAsyncNodeManager` for full async support
|
|
- `ICallAsyncNodeManager` for async method calls
|
|
- `IReadAsyncNodeManager` for async reading
|
|
- `IWriteAsyncNodeManager` for async writing
|
|
- `IHistoryReadAsyncNodeManager` for async history read
|
|
- `IHistoryUpdateAsyncNodeManager` for async history update
|
|
- `IConditionRefreshAsyncNodeManager` for async condition refresh
|
|
- `ITranslateBrowsePathAsyncNodeManager` for async translate browse path
|
|
- `IBrowseAsyncNodeManager` for async browsing
|
|
- `ISetMonitoringModeAsyncNodeManager` for async monitoring mode changes
|
|
- `ITransferMonitoredItemsAsyncNodeManager` for async monitored item transfer
|
|
- `IDeleteMonitoredItemsAsyncNodeManager` for async monitored item deletion
|
|
- `IModifyMonitoredItemsAsyncNodeManager` for async monitored item modification
|
|
- `ICreateMonitoredItemsAsyncNodeManager` for async monitored item creation
|
|
|
|
--> The MasterNodeManager automatically detects if a NodeManager implements any of the async interfaces and uses the async implementation if available. If no async interface is implemented, the sync implementation is used.
|
|
|
|
- The Server already allows to register fully async NodeManagers, which implement the `IAsyncNodeManager` interface. To register a fully async Nodemanager use `StandardServer.RegisterNodeManager(IAsyncNodeManagerFactory)`.
|
|
For compatibility reasons the IAsyncNodeManager has a property `SyncNodeManager`, this needs to be implemented by passing your IAsyncNodeManager to the `SyncNodeManagerAdapter`.
|
|
|
|
## Async Method call
|
|
|
|
Support for async method callbacks is already implemented by `CustomNodeManager2` to enable the support just add `IAsyncNodeManager` to your NodeManager implementation.
|
|
All generated code already has support for Async Methods e.g. `UpdateCertificateMethodState.OnCallAsync`. If the NodeManager implements `IAsyncNodeManager` the async callback is used automatically.
|
|
If a generic Method handler shall be used the `MethodState.OnCallMethod2Async` handler shall be used. |