[release/7.0] Reset LocalView when returning context to the pool (#29181

)

src/EFCore/ChangeTracking/LocalView.cs

@@ -499,4 +499,23 @@ IList IListSource.GetList()
     /// </summary>
     bool IListSource.ContainsListCollection
         => false;
+
+    /// <summary>
+    ///     Resets this view, clearing any <see cref="IBindingList" /> created with <see cref="ToBindingList" /> and
+    ///     any <see cref="ObservableCollection{T}" /> created with <see cref="ToObservableCollection" />, and clearing any
+    ///     events registered on <see cref="PropertyChanged" />, <see cref="PropertyChanging" />, or <see cref="CollectionChanged" />.
+    /// </summary>
+    public virtual void Reset()
+    {
+        _bindingList = null;
+        _observable = null;
+        _countChanges = 0;
+        _count = 0;
+        _triggeringStateManagerChange = false;
+        _triggeringObservableChange = false;
+        _triggeringLocalViewChange = false;
+        PropertyChanged = null;
+        PropertyChanging = null;
+        CollectionChanged = null;
+    }
 }

src/EFCore/Internal/InternalDbSet.cs

@@ -520,16 +520,14 @@ IServiceProvider IInfrastructure<IServiceProvider>.Instance
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
     void IResettableService.ResetState()
-        => _localView = null;
+        => _localView?.Reset();
 
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    /// <param name="cancellationToken">A <see cref="CancellationToken" /> to observe while waiting for the task to complete.</param>
-    /// <exception cref="OperationCanceledException">If the <see cref="CancellationToken" /> is canceled.</exception>
     Task IResettableService.ResetStateAsync(CancellationToken cancellationToken)
     {
         ((IResettableService)this).ResetState();

test/EFCore.SqlServer.FunctionalTests/DbContextPoolingTest.cs

@@ -1,6 +1,9 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
+using System.ComponentModel;
 using System.Data;
 using Microsoft.Data.SqlClient;
 using Microsoft.EntityFrameworkCore.Internal;
@@ -164,6 +167,12 @@ public class Customer
     {
         public string CustomerId { get; set; }
         public string CompanyName { get; set; }
+        public ObservableCollection<Order> Orders { get; } = new();
+    }
+
+    public class Order
+    {
+        public string OrderId { get; set; }
     }
 
     private interface ISecondContext
@@ -768,6 +777,20 @@ public async Task Context_configuration_is_reset(bool useInterface, bool async)
 
         Assert.Null(context1!.Database.GetCommandTimeout());
 
+        var set = context1.Customers;
+        var localView = set.Local;
+        localView.PropertyChanged += LocalView_OnPropertyChanged;
+        localView.PropertyChanging += LocalView_OnPropertyChanging;
+        localView.CollectionChanged += LocalView_OnCollectionChanged;
+        var customer1 = new Customer { CustomerId = "C" };
+        context1.Customers.Attach(customer1);
+        Assert.Equal(1, localView.Count);
+        Assert.Same(customer1, localView.ToBindingList().Single());
+        Assert.Same(customer1, localView.ToObservableCollection().Single());
+        Assert.True(_localView_OnPropertyChanging);
+        Assert.True(_localView_OnPropertyChanged);
+        Assert.True(_localView_OnCollectionChanged);
+
         context1.ChangeTracker.AutoDetectChangesEnabled = true;
         context1.ChangeTracker.LazyLoadingEnabled = true;
         context1.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
@@ -788,6 +811,10 @@ public async Task Context_configuration_is_reset(bool useInterface, bool async)
         context1.SavedChanges += Context_OnSavedChanges;
         context1.SaveChangesFailed += Context_OnSaveChangesFailed;
 
+        _localView_OnPropertyChanging = false;
+        _localView_OnPropertyChanged = false;
+        _localView_OnCollectionChanged = false;
+
         await Dispose(serviceScope, async);
 
         serviceScope = serviceProvider.CreateScope();
@@ -808,9 +835,13 @@ public async Task Context_configuration_is_reset(bool useInterface, bool async)
         Assert.False(context2.Database.AutoSavepointsEnabled);
         Assert.Null(context1.Database.GetCommandTimeout());
 
-        var customer = new Customer { CustomerId = "C" };
-        context2.Customers.Attach(customer).State = EntityState.Modified;
-        context2.Customers.Attach(customer).State = EntityState.Unchanged;
+        Assert.Empty(localView);
+        Assert.Empty(localView.ToBindingList());
+        Assert.Empty(localView.ToObservableCollection());
+
+        var customer2 = new Customer { CustomerId = "C" };
+        context2.Customers.Attach(customer2).State = EntityState.Modified;
+        context2.Customers.Attach(customer2).State = EntityState.Unchanged;
 
         Assert.False(_changeTracker_OnTracking);
         Assert.False(_changeTracker_OnTracked);
@@ -826,6 +857,15 @@ public async Task Context_configuration_is_reset(bool useInterface, bool async)
         Assert.False(_context_OnSavedChanges);
         Assert.False(_context_OnSavingChanges);
         Assert.False(_context_OnSaveChangesFailed);
+
+        Assert.Same(set, context2!.Customers);
+        Assert.Same(localView, context2!.Customers.Local);
+        Assert.Equal(1, localView.Count);
+        Assert.Same(customer2, localView.ToBindingList().Single());
+        Assert.Same(customer2, localView.ToObservableCollection().Single());
+        Assert.False(_localView_OnPropertyChanging);
+        Assert.False(_localView_OnPropertyChanged);
+        Assert.False(_localView_OnCollectionChanged);
     }
 
     [ConditionalTheory]
@@ -865,6 +905,20 @@ public async Task Context_configuration_is_reset_with_factory(bool async, bool w
         var factory = BuildFactory<PooledContext>(withDependencyInjection);
 
         var context1 = async ? await factory.CreateDbContextAsync() : factory.CreateDbContext();
+        var set = context1.Customers;
+
+        var localView = set.Local;
+        localView.PropertyChanged += LocalView_OnPropertyChanged;
+        localView.PropertyChanging += LocalView_OnPropertyChanging;
+        localView.CollectionChanged += LocalView_OnCollectionChanged;
+        var customer1 = new Customer { CustomerId = "C" };
+        context1.Customers.Attach(customer1);
+        Assert.Equal(1, localView.Count);
+        Assert.Same(customer1, localView.ToBindingList().Single());
+        Assert.Same(customer1, localView.ToObservableCollection().Single());
+        Assert.True(_localView_OnPropertyChanging);
+        Assert.True(_localView_OnPropertyChanged);
+        Assert.True(_localView_OnCollectionChanged);
 
         context1.ChangeTracker.AutoDetectChangesEnabled = true;
         context1.ChangeTracker.LazyLoadingEnabled = true;
@@ -885,15 +939,23 @@ public async Task Context_configuration_is_reset_with_factory(bool async, bool w
         context1.SavedChanges += Context_OnSavedChanges;
         context1.SaveChangesFailed += Context_OnSaveChangesFailed;
 
+        _localView_OnPropertyChanging = false;
+        _localView_OnPropertyChanged = false;
+        _localView_OnCollectionChanged = false;
+
         await Dispose(context1, async);
 
         var context2 = async ? await factory.CreateDbContextAsync() : factory.CreateDbContext();
 
         Assert.Same(context1, context2);
 
-        var customer = new Customer { CustomerId = "C" };
-        context2.Customers.Attach(customer).State = EntityState.Modified;
-        context2.Customers.Attach(customer).State = EntityState.Unchanged;
+        Assert.Empty(localView);
+        Assert.Empty(localView.ToBindingList());
+        Assert.Empty(localView.ToObservableCollection());
+
+        var customer2 = new Customer { CustomerId = "C" };
+        context2.Customers.Attach(customer2).State = EntityState.Modified;
+        context2.Customers.Attach(customer2).State = EntityState.Unchanged;
 
         Assert.False(_changeTracker_OnTracking);
         Assert.False(_changeTracker_OnTracked);
@@ -909,6 +971,15 @@ public async Task Context_configuration_is_reset_with_factory(bool async, bool w
         Assert.False(_context_OnSavedChanges);
         Assert.False(_context_OnSavingChanges);
         Assert.False(_context_OnSaveChangesFailed);
+
+        Assert.Same(set, context2!.Customers);
+        Assert.Same(localView, context2!.Customers.Local);
+        Assert.Equal(1, localView.Count);
+        Assert.Same(customer2, localView.ToBindingList().Single());
+        Assert.Same(customer2, localView.ToObservableCollection().Single());
+        Assert.False(_localView_OnPropertyChanging);
+        Assert.False(_localView_OnPropertyChanged);
+        Assert.False(_localView_OnCollectionChanged);
     }
 
     [ConditionalFact]
@@ -995,6 +1066,21 @@ private void Context_OnSaveChangesFailed(object sender, SaveChangesFailedEventAr
 
     private bool _context_OnSaveChangesFailed;
 
+    private bool _localView_OnPropertyChanged;
+
+    private void LocalView_OnPropertyChanged(object sender, PropertyChangedEventArgs e)
+        => _localView_OnPropertyChanged = true;
+
+    private bool _localView_OnPropertyChanging;
+
+    private void LocalView_OnPropertyChanging(object sender, PropertyChangingEventArgs e)
+        => _localView_OnPropertyChanging = true;
+
+    private bool _localView_OnCollectionChanged;
+
+    private void LocalView_OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+        => _localView_OnCollectionChanged = true;
+
     private bool _changeTracker_OnTracking;
 
     private void ChangeTracker_OnTracking(object sender, EntityTrackingEventArgs e)