fix: dotnet/efcore#26202

samples/HelloCart/v2/AppDbContext.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using Microsoft.EntityFrameworkCore;
+using Stl.Fusion.EntityFramework;
 using Stl.Fusion.EntityFramework.Operations;
 
 namespace Samples.HelloCart.V2
@@ -24,7 +25,7 @@ public class DbCartItem
         public decimal Quantity { get; set; }
     }
 
-    public class AppDbContext : DbContext
+    public class AppDbContext : DbContextBase
     {
         public DbSet<DbProduct> Products { get; protected set; } = null!;
         public DbSet<DbCart> Carts { get; protected set; } = null!;

samples/TodoApp/Services/AppDbContext.cs

@@ -1,11 +1,12 @@
 using Microsoft.EntityFrameworkCore;
+using Stl.Fusion.EntityFramework;
 using Stl.Fusion.EntityFramework.Authentication;
 using Stl.Fusion.EntityFramework.Extensions;
 using Stl.Fusion.EntityFramework.Operations;
 
 namespace Templates.TodoApp.Services
 {
-    public class AppDbContext : DbContext
+    public class AppDbContext : DbContextBase
     {
         // Stl.Fusion.EntityFramework tables
         public DbSet<DbUser<string>> Users { get; protected set; } = null!;

src/Stl.Fusion.EntityFramework/DbContextBase.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+
+namespace Stl.Fusion.EntityFramework
+{
+    /// <summary>
+    /// This type solves a single problem: currently EF Core 6.0
+    /// doesn't properly dispose pooled DbContexts rendering
+    /// them unusable after disposal.
+    /// Details: https://github.com/dotnet/efcore/issues/26202
+    /// </summary>
+    public abstract class DbContextBase :
+#if NET6_0
+        DbContext, IResettableService
+#else
+        DbContext
+#endif
+    {
+#if NET6_0
+        private static readonly FieldInfo DisposedField =
+            typeof(DbContext).GetField("_disposed", BindingFlags.Instance | BindingFlags.NonPublic)!;
+        private static readonly MethodInfo GetResettableServicesMethod =
+            typeof(DbContext).GetMethod("GetResettableServices", BindingFlags.Instance | BindingFlags.NonPublic)!;
+#endif
+
+        protected DbContextBase() { }
+        protected DbContextBase(DbContextOptions options) : base(options) { }
+
+#if NET6_0
+        void IResettableService.ResetState()
+        {
+            var services = GetResettableServices2();
+            foreach (var service in services)
+                service.ResetState();
+            DisposedField.SetValue(this, false);
+        }
+
+        async Task IResettableService.ResetStateAsync(CancellationToken cancellationToken = default)
+        {
+            var services = GetResettableServices2();
+            foreach (var service in services)
+                await service.ResetStateAsync(cancellationToken).ConfigureAwait(false);
+            DisposedField.SetValue(this, false);
+        }
+
+        private IEnumerable<IResettableService> GetResettableServices2()
+            => (IEnumerable<IResettableService>) GetResettableServicesMethod.Invoke(
+                this,
+                Array.Empty<object>())!;
+#endif
+    }
+}

tests/Stl.Fusion.Tests/Model/TestDbContext.cs

@@ -12,7 +12,7 @@ public class DbAuthUser : DbUser<long>
     public class DbAuthSessionInfo : DbSessionInfo<long>
     { }
 
-    public class TestDbContext : DbContext
+    public class TestDbContext : DbContextBase
     {
         public DbSet<User> Users { get; protected set; } = null!;
         public DbSet<Message> Messages { get; protected set; } = null!;

tests/Stl.Fusion.Tests/PerformanceTest.cs

@@ -40,8 +40,8 @@ public override async Task InitializeAsync()
             await Task.WhenAll(tasks);
         }
 
-        // [Fact]
-        [Fact(Skip = "Performance")]
+        [Fact]
+        // [Fact(Skip = "Performance")]
         public async Task ComputedPerformanceTest()
         {
             if (TestRunnerInfo.IsBuildAgent())

tests/Stl.Fusion.Tests/Services/UserService.cs

@@ -135,7 +135,7 @@ public virtual async Task<bool> Delete(IUserService.DeleteCommand command, Cance
         {
             // Debug.WriteLine($"TryGetAsync {userId}");
             await Everything().ConfigureAwait(false);
-            await using var dbContext = DbContextFactory.CreateDbContext();
+            await using var dbContext = CreateDbContext();
             var user = await dbContext.Users
                 .FindAsync(new[] {(object) userId}, cancellationToken)
                 .ConfigureAwait(false);
@@ -145,7 +145,7 @@ public virtual async Task<bool> Delete(IUserService.DeleteCommand command, Cance
         public virtual async Task<long> Count(CancellationToken cancellationToken = default)
         {
             await Everything().ConfigureAwait(false);
-            await using var dbContext = DbContextFactory.CreateDbContext();
+            await using var dbContext = CreateDbContext();
             var count = await dbContext.Users.LongCountAsync(cancellationToken).ConfigureAwait(false);
             // _log.LogDebug($"Users.Count query: {count}");
             return count;

tests/Stl.Tests/CommandR/Services/Db/TestDbContext.cs

@@ -1,9 +1,10 @@
 using Microsoft.EntityFrameworkCore;
+using Stl.Fusion.EntityFramework;
 using Stl.Fusion.EntityFramework.Operations;
 
 namespace Stl.Tests.CommandR.Services
 {
-    public class TestDbContext : DbContext
+    public class TestDbContext : DbContextBase
     {
         public DbSet<DbOperation> Operations { get; protected set; } = null!;
         public DbSet<User> Users { get; protected set; } = null!;