[Server] [Performance] Reduce locking in CustomNodeManager2

[romanett]

Proposed changes

• Make NodeIdDictionary a ConcurrentDictionary and therefore allow to gradually remove locks from many parts of the server
• Update (m_)PredefinedNodes in CustomNodeManager2 to be used without locks
• make m_namespaceUris + (m_)NamespaceIndexes in CustomNodeManager2 ReadOnlyCollections and therefore threadsafe
• make m_componentCache a NodeIdDictionary
• make m_rootNotifiers a NodeIdDictionary
• make (m_)MonitoredNodes a NodeIdDictionary (faster compare + concurrentDictionary)
• make IsNodeInNamespace /IsHandleInNamespace /GetManagerHandle threadsafe
• make underlying List of MIs in MonitoredNode a ConcurrentDictionary instead of lists, as the implementation before was not efficient

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds functionality)
• Test enhancement (non-breaking change to increase test coverage)
• Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc.
• I have signed the CLA.
• I ran tests locally with my changes, all passed.
• I fixed all failing tests in the CI pipelines.
• I fixed all introduced issues with CodeQL and LGTM.
• I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• I have added necessary documentation (if appropriate).
• Any dependent changes have been merged and published in downstream modules.

Further comments

ToDo

• Concurrent tests for RootNotifier & MonitoredNode

Optimized Methods:

• AlarmNodeManager Call
  CustomNodeManger:
• SetNamespaces / SetNamespaceIndexes / IsNodeIdInNamespace (make thread safe by using IReadOnlyCollection for m_namespaceUris + (m_)NamespaceIndexes)
• Find(remove lock)
• DeleteNode (remove lock, only lock modifying m_rootNotifiers)
• AddPredefinedNode
• AddRootNotifier, RemoveRootNotifier (make Lock Free)
• DeleteAddressSpace (remove lock by copying predefined nodes to temp array)
• GetManagerHandle remove lock (IsNodeIdInNamespace & m_predefinedNodes are threadsafe)
• DeleteReference, GetNodeMetadata, GetPermissionMetadata, Browse, TranslateBrowsePath, Call (lock only after validating nodes are in the namespace of the NodeManager)
• CreateMonitoredItems, ModifyMonitoredItems, DeleteMonitoredItems, SetMonitoringMode (lock only after validating nodes are in the namespace of the NodeManager)
• LookupNodeInComponentCache, RemoveNodeFromComponentCache, AddNodeToComponentCache (Make these methods work Lock Free by making m_componentCache a NodeIDictionary)
• SubscribeToEvents (Add missing locks in callers)

Parallel Tests:

• ComponentCache
• PredefinedNodesDictionary

To Decide:

• iterate over Values of Dictionary (snapshot) or iterate KVPs (updated in Realtime, no snapshot)

[codecov]

Codecov Report

Attention: Patch coverage is 63.06306% with 82 lines in your changes missing coverage. Please review.

Project coverage is 55.40%. Comparing base (0777bbd) to head (c427487).
Report is 4 commits behind head on master.

Files with missing lines	Patch %	Lines
...ies/Opc.Ua.Server/Diagnostics/CustomNodeManager.cs	65.02%	49 Missing and 15 partials ⚠️
...braries/Opc.Ua.Server/Diagnostics/MonitoredNode.cs	48.14%	10 Missing and 4 partials ⚠️
...tack/Opc.Ua.Core/Types/BuiltIn/NodeIdDictionary.cs	62.50%	2 Missing and 1 partial ⚠️
...ibraries/Opc.Ua.Client/Session/TraceableSession.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2895      +/-   ##
==========================================
- Coverage   55.43%   55.40%   -0.04%     
==========================================
  Files         352      352              
  Lines       67602    67561      -41     
  Branches    13849    13830      -19     
==========================================
- Hits        37477    37433      -44     
- Misses      26021    26028       +7     
+ Partials     4104     4100       -4     

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[mregen]

lets chat about this, I have some ideas...

[romanett]

Test Issue:

Failed TestComponentCacheAsync [4 s]
Error Message:
Assert.That(handleFromCache, Is.Not.Null)
Expected: not null
But was: null

Stack Trace:
at Opc.Ua.Server.Tests.CustomNodeManagerTests.UseComponentCacheAsync(TestableCustomNodeManger2 nodeManager, BaseObjectState baseObject, NodeHandle nodeHandle) in //Tests/Opc.Ua.Server.Tests/CustomNodeManagerTests.cs:line 150
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)
at Opc.Ua.Server.Tests.CustomNodeManagerTests.UseComponentCacheAsync(TestableCustomNodeManger2 nodeManager, BaseObjectState baseObject, NodeHandle nodeHandle)
at Opc.Ua.Server.Tests.CustomNodeManagerTests.<>c__DisplayClass0_0.b__0() in //Tests/Opc.Ua.Server.Tests/CustomNodeManagerTests.cs:line 41
at Opc.Ua.Server.Tests.CustomNodeManagerTests.<>c__DisplayClass4_0.<b__0>d.MoveNext() in /_/Tests/Opc.Ua.Server.Tests/CustomNodeManagerTests.cs:line 177

[romanett]

We need to enshure Data Changes reach each monitored Item in the right order i would sugesst a semaphore only for this method. No need to lock the entire node manager to enshure this behaviour (the node changes reach this method anyway)

[romanett]

Use Parallel.ForEach