Use new lock primitive

.editorconfig

@@ -361,7 +361,7 @@ dotnet_diagnostic.SA1113.severity = error
 dotnet_diagnostic.SA1114.severity = none
 dotnet_diagnostic.SA1115.severity = error
 dotnet_diagnostic.SA1116.severity = none
-dotnet_diagnostic.SA1117.severity = error
+dotnet_diagnostic.SA1117.severity = none
 dotnet_diagnostic.SA1118.severity = none
 dotnet_diagnostic.SA1119.severity = error
 dotnet_diagnostic.SA1120.severity = error
@@ -380,7 +380,7 @@ dotnet_diagnostic.SA1133.severity = error
 dotnet_diagnostic.SA1134.severity = error
 dotnet_diagnostic.SA1135.severity = error
 dotnet_diagnostic.SA1136.severity = error
-dotnet_diagnostic.SA1137.severity = error
+dotnet_diagnostic.SA1137.severity = none
 dotnet_diagnostic.SA1139.severity = error
 dotnet_diagnostic.SA1200.severity = none
 dotnet_diagnostic.SA1201.severity = none

src/DynamicData/Aggregation/SumEx.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Aggregation;
 
 /// <summary>

src/DynamicData/Alias/ObservableCacheAlias.cs

@@ -4,8 +4,6 @@
 
 using System.Reactive;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Alias;
 
 /// <summary>

src/DynamicData/Binding/ExpressionBuilder.cs

@@ -5,7 +5,6 @@
 using System.ComponentModel;
 using System.Linq.Expressions;
 using System.Reactive;
-using System.Reactive.Disposables;
 using System.Reactive.Linq;
 using System.Reflection;
 

src/DynamicData/Binding/ObservableCollectionEx.cs

@@ -6,7 +6,6 @@
 using System.Collections.Specialized;
 using System.Reactive;
 using System.Reactive.Linq;
-using DynamicData.Kernel;
 
 namespace DynamicData.Binding;
 

src/DynamicData/Binding/SortAndBind.cs

@@ -65,7 +65,7 @@ public SortAndBind(IObservable<IChangeSet<TObject, TKey>> source,
                 comparerChanged = comparerChanged.ObserveOn(scheduler);
             }
 
-            var locker = new object();
+            var locker = InternalEx.NewLock();
             SortApplicator? sortApplicator = null;
 
             // Create a new sort applicator each time.

src/DynamicData/Cache/CacheChangeSetEx.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache;
 
 internal static class CacheChangeSetEx

src/DynamicData/Cache/Change.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 // ReSharper disable once CheckNamespace
 namespace DynamicData;
 

src/DynamicData/Cache/ChangeAwareCache.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for full license information.
 
 using DynamicData.Cache;
-using DynamicData.Kernel;
 
 // ReSharper disable once CheckNamespace
 namespace DynamicData;

src/DynamicData/Cache/IGrouping.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 // ReSharper disable once CheckNamespace
 namespace DynamicData;
 

src/DynamicData/Cache/IObservableCache.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 // ReSharper disable once CheckNamespace
 namespace DynamicData;
 

src/DynamicData/Cache/IQuery.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 // ReSharper disable once CheckNamespace
 namespace DynamicData;
 

src/DynamicData/Cache/IntermediateCache.cs

@@ -4,7 +4,6 @@
 
 using System.Diagnostics;
 using DynamicData.Binding;
-using DynamicData.Kernel;
 
 // ReSharper disable once CheckNamespace
 namespace DynamicData;

src/DynamicData/Cache/Internal/AbstractFilter.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal abstract class AbstractFilter<TObject, TKey> : IFilter<TObject, TKey>

src/DynamicData/Cache/Internal/AnonymousObservableCache.cs

@@ -4,7 +4,6 @@
 
 using System.Diagnostics;
 using System.Reactive.Disposables;
-using DynamicData.Kernel;
 
 namespace DynamicData.Cache.Internal;
 

src/DynamicData/Cache/Internal/AnonymousQuery.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class AnonymousQuery<TObject, TKey>(Cache<TObject, TKey> cache) : IQuery<TObject, TKey>

src/DynamicData/Cache/Internal/AutoRefresh.cs

@@ -32,7 +32,7 @@ public IObservable<IChangeSet<TObject, TKey>> Run() => Observable.Create<IChange
                     changes.Buffer(buffer.Value, _scheduler).Where(list => list.Count > 0).Select(items => new ChangeSet<TObject, TKey>(items));
 
                 // publish refreshes and underlying changes
-                var locker = new object();
+                var locker = InternalEx.NewLock();
                 var publisher = shared.Synchronize(locker).Merge(refreshChanges.Synchronize(locker)).SubscribeSafe(observer);
 
                 return new CompositeDisposable(publisher, shared.Connect());

src/DynamicData/Cache/Internal/BatchIf.cs

@@ -23,7 +23,7 @@ public IObservable<ChangeSet<TObject, TKey>> Run() => Observable.Create<ChangeSe
             observer =>
             {
                 var batchedChanges = new List<IChangeSet<TObject, TKey>>();
-                var locker = new object();
+                var locker = InternalEx.NewLock();
                 var paused = initialPauseState;
                 var timeoutDisposer = new SerialDisposable();
                 var intervalTimerDisposer = new SerialDisposable();

src/DynamicData/Cache/Internal/Cache.cs

@@ -4,8 +4,6 @@
 
 using System.Diagnostics;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 [DebuggerDisplay("Cache<{typeof(TObject).Name}, {typeof(TKey).Name}> ({Count} Items)")]

src/DynamicData/Cache/Internal/CacheUpdater.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class CacheUpdater<TObject, TKey> : ISourceUpdater<TObject, TKey>

src/DynamicData/Cache/Internal/Cast.cs

@@ -4,8 +4,6 @@
 
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class Cast<TSource, TKey, TDestination>(IObservable<IChangeSet<TSource, TKey>> source, Func<TSource, TDestination> converter)

src/DynamicData/Cache/Internal/ChangeSetMergeTracker.cs

@@ -2,9 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System.Reactive.Linq;
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class ChangeSetMergeTracker<TObject, TKey>(Func<IEnumerable<ChangeSetCache<TObject, TKey>>> selectCaches, IComparer<TObject>? comparer, IEqualityComparer<TObject>? equalityComparer)

src/DynamicData/Cache/Internal/Combiner.cs

@@ -4,8 +4,6 @@
 
 using System.Reactive.Disposables;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 /// <summary>
@@ -17,7 +15,11 @@ internal sealed class Combiner<TObject, TKey>(CombineOperator type, Action<IChan
 {
     private readonly ChangeAwareCache<TObject, TKey> _combinedCache = new();
 
+#if NET9_0_OR_GREATER
+    private readonly Lock _locker = new();
+#else
     private readonly object _locker = new();
+#endif
 
     private readonly IList<Cache<TObject, TKey>> _sourceCaches = new List<Cache<TObject, TKey>>();
 

src/DynamicData/Cache/Internal/DeferUntilLoaded.cs

@@ -4,8 +4,6 @@
 
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class DeferUntilLoaded<TObject, TKey>

src/DynamicData/Cache/Internal/DistinctCalculator.cs

@@ -4,8 +4,6 @@
 
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class DistinctCalculator<TObject, TKey, TValue>(IObservable<IChangeSet<TObject, TKey>> source, Func<TObject, TValue> valueSelector)

src/DynamicData/Cache/Internal/DynamicCombiner.cs

@@ -5,8 +5,6 @@
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class DynamicCombiner<TObject, TKey>(IObservableList<IObservable<IChangeSet<TObject, TKey>>> source, CombineOperator type)
@@ -18,7 +16,7 @@ internal sealed class DynamicCombiner<TObject, TKey>(IObservableList<IObservable
     public IObservable<IChangeSet<TObject, TKey>> Run() => Observable.Create<IChangeSet<TObject, TKey>>(
             observer =>
             {
-                var locker = new object();
+                var locker = InternalEx.NewLock();
 
                 // this is the resulting cache which produces all notifications
                 var resultCache = new ChangeAwareCache<TObject, TKey>();

src/DynamicData/Cache/Internal/DynamicFilter.cs

@@ -22,7 +22,7 @@ public IObservable<IChangeSet<TObject, TKey>> Run() => Observable.Create<IChange
                 var filteredData = new ChangeAwareCache<TObject, TKey>();
                 Func<TObject, bool> predicate = _ => false;
 
-                var locker = new object();
+                var locker = InternalEx.NewLock();
 
                 var refresher = LatestPredicateObservable().Synchronize(locker).Select(
                     p =>

src/DynamicData/Cache/Internal/DynamicGrouper.cs

@@ -4,7 +4,6 @@
 
 using System.Diagnostics;
 using System.Reactive.Disposables;
-using DynamicData.Kernel;
 
 namespace DynamicData.Cache.Internal;
 

src/DynamicData/Cache/Internal/EditDiff.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class EditDiff<TObject, TKey>(ISourceCache<TObject, TKey> source, Func<TObject, TObject, bool> areEqual)

src/DynamicData/Cache/Internal/EditDiffChangeSet.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System.Reactive.Linq;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class EditDiffChangeSet<TObject, TKey>(IObservable<IEnumerable<TObject>> source, Func<TObject, TKey> keySelector, IEqualityComparer<TObject>? equalityComparer)

src/DynamicData/Cache/Internal/EditDiffChangeSetOptional.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for full license information.
 
 using System.Reactive.Linq;
-using DynamicData.Kernel;
 
 namespace DynamicData.Cache.Internal;
 

src/DynamicData/Cache/Internal/Filter.WithPredicateState.cs

@@ -2,12 +2,7 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Reactive;
-using System.Reactive.Disposables;
 using System.Reactive.Linq;
-using System.Transactions;
-
 using DynamicData.Internal;
 
 namespace DynamicData.Cache.Internal;

src/DynamicData/Cache/Internal/FilteredIndexCalculator.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal static class FilteredIndexCalculator<TObject, TKey>

src/DynamicData/Cache/Internal/FullJoin.cs

@@ -5,8 +5,6 @@
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class FullJoin<TLeft, TLeftKey, TRight, TRightKey, TDestination>(IObservable<IChangeSet<TLeft, TLeftKey>> left, IObservable<IChangeSet<TRight, TRightKey>> right, Func<TRight, TLeftKey> rightKeySelector, Func<TLeftKey, Optional<TLeft>, Optional<TRight>, TDestination> resultSelector)
@@ -27,7 +25,7 @@ internal sealed class FullJoin<TLeft, TLeftKey, TRight, TRightKey, TDestination>
     public IObservable<IChangeSet<TDestination, TLeftKey>> Run() => Observable.Create<IChangeSet<TDestination, TLeftKey>>(
             observer =>
             {
-                var locker = new object();
+                var locker = InternalEx.NewLock();
 
                 // create local backing stores
                 var leftCache = _left.Synchronize(locker).AsObservableCache(false);

src/DynamicData/Cache/Internal/FullJoinMany.cs

@@ -2,8 +2,6 @@
 // Roland Pheasant licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class FullJoinMany<TLeft, TLeftKey, TRight, TRightKey, TDestination>(IObservable<IChangeSet<TLeft, TLeftKey>> left, IObservable<IChangeSet<TRight, TRightKey>> right, Func<TRight, TLeftKey> rightKeySelector, Func<TLeftKey, Optional<TLeft>, IGrouping<TRight, TRightKey, TLeftKey>, TDestination> resultSelector)

src/DynamicData/Cache/Internal/GroupOn.cs

@@ -6,8 +6,6 @@
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class GroupOn<TObject, TKey, TGroupKey>(IObservable<IChangeSet<TObject, TKey>> source, Func<TObject, TGroupKey> groupSelectorKey, IObservable<Unit>? regrouper)
@@ -24,7 +22,7 @@ internal sealed class GroupOn<TObject, TKey, TGroupKey>(IObservable<IChangeSet<T
     public IObservable<IGroupChangeSet<TObject, TKey, TGroupKey>> Run() => Observable.Create<IGroupChangeSet<TObject, TKey, TGroupKey>>(
             observer =>
             {
-                var locker = new object();
+                var locker = InternalEx.NewLock();
                 var grouper = new Grouper(_groupSelectorKey);
 
                 var groups = _source.Finally(observer.OnCompleted).Synchronize(locker).Select(grouper.Update).Where(changes => changes.Count != 0);

src/DynamicData/Cache/Internal/GroupOnDynamic.cs

@@ -6,7 +6,6 @@
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
 using DynamicData.Internal;
-using DynamicData.Kernel;
 
 namespace DynamicData.Cache.Internal;
 

src/DynamicData/Cache/Internal/GroupOnImmutable.cs

@@ -5,8 +5,6 @@
 using System.Reactive;
 using System.Reactive.Linq;
 
-using DynamicData.Kernel;
-
 namespace DynamicData.Cache.Internal;
 
 internal sealed class GroupOnImmutable<TObject, TKey, TGroupKey>(IObservable<IChangeSet<TObject, TKey>> source, Func<TObject, TGroupKey> groupSelectorKey, IObservable<Unit>? regrouper)
@@ -23,7 +21,7 @@ internal sealed class GroupOnImmutable<TObject, TKey, TGroupKey>(IObservable<ICh
     public IObservable<IImmutableGroupChangeSet<TObject, TKey, TGroupKey>> Run() => Observable.Create<IImmutableGroupChangeSet<TObject, TKey, TGroupKey>>(
             observer =>
             {
-                var locker = new object();
+                var locker = InternalEx.NewLock();
                 var grouper = new Grouper(_groupSelectorKey);
 
                 var groups = _source.Synchronize(locker).Select(grouper.Update).Where(changes => changes.Count != 0);