Memory leak when using a shared CancellationTokenSource

[QianMoXi]

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use a shared cancellationTokenSource, memory usage is getting too high to be freed:

use CancellationToken.None:

Example

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

internal class Program
{
    private static IServiceProvider _serviceProvider = CreateServiceProvider();

    public static async Task Main(string[] args)
    {
        //If you use a Shared CancellationTokenSource, will cause the memory cannot be released
        var shareTokenSource = new CancellationTokenSource();
        await InitDbAsync(shareTokenSource.Token);
        await WriteToDbAsync(shareTokenSource.Token);

        //If you use CancellationToken.None, no such problem occurs
        await InitDbAsync(CancellationToken.None);
        await WriteToDbAsync(CancellationToken.None);
    }

    public static async Task InitDbAsync(CancellationToken cancellationToken)
    {
        await using var context = await _serviceProvider.GetRequiredService<IDbContextFactory<MyDbContext>>().CreateDbContextAsync(cancellationToken);
        await context.Database.EnsureDeletedAsync(cancellationToken);
        await context.Database.EnsureCreatedAsync(cancellationToken);
    }

    public static async Task WriteToDbAsync(CancellationToken cancellationToken)
    {
        for (var i = 0; i < 1000; i++)
        {
            await using var context = await _serviceProvider.GetRequiredService<IDbContextFactory<MyDbContext>>().CreateDbContextAsync(cancellationToken);

            var data = Enumerable.Range(0, 1000).Select(_ => new TableA()).ToList();

            await context.AddRangeAsync(data, cancellationToken);

            await context.SaveChangesAsync(cancellationToken);

            Console.WriteLine($"{i} TotalMemory: {GC.GetTotalMemory(true)}");
        }

    }

    public static IServiceProvider CreateServiceProvider()
    {
        var services = new ServiceCollection();
        services.AddDbContextFactory<MyDbContext>(builder =>
        {
            builder.UseSqlServer("Data Source=.;Initial Catalog=DbMemoryTest;MultipleActiveResultSets=True;Encrypt=False;Integrated Security=SSPI", b =>
            {
                b.EnableRetryOnFailure();
            });
        });

        return services.BuildServiceProvider();
    }

    public class MyDbContext : DbContext
    {
        public DbSet<TableA> TableAs { get; set; }
        public MyDbContext(DbContextOptions options) : base(options)
        {
        }
    }

    public class TableA
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        public Guid Property1 { get; set; } = Guid.NewGuid();
        public Guid Property2 { get; set; } = Guid.NewGuid();
        public Guid Property3 { get; set; } = Guid.NewGuid();
        public Guid Property4 { get; set; } = Guid.NewGuid();
    }
}

Possible reasons

Data is always in ExecutionContext

Include provider and version information

EF Core version: 7.0.4
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: .NET 7.0
Operating system: Windows 11 22H2
IDE: Visual Studio 2022 17.5.2

[ajcvickers]

This only repros with Microsoft.Data.SqlClient 5.0.1, not on 5.1.0. Likely dotnet/SqlClient#1810

@QianMoXi Explicitly reference Microsoft.Data.SqlClient 5.1.0. For example:

<PackageReference Include="Microsoft.Data.SqlClient" Version="5.1.0" />

[QianMoXi]

@ajcvickers Thanks, it works fine

[roji]

Duplicate of dotnet/SqlClient#1810