C#•3d ago

Cannot access a disposed context instance.

I'm receiving the ObjectDisposedException about a DbContext being disposed while using IDbContextFactory<> to initialize my database context. After searching online for potential ways for me to approach resolving this, none of them seem to apply for my case. Code:

logger.LogInformation("{Availability} Guild {Name} has just been created.", $"{(gatewayEvent.Guild.IsT0 ? "A" : "Una")}vailable", gatewayEvent.Guild.IsT0 ? gatewayEvent.Guild.AsT0.Name : gatewayEvent.Guild.AsT1.ID.ToString());
        
if (gatewayEvent.Guild.IsT1) return Result.FromSuccess();

var guild = gatewayEvent.Guild.AsT0;
var guildModel = new GuildModel(guild, configuration["PREFIX"]!);

await using (var databaseContext = await database.CreateDbContextAsync(ct))
{
    var dbGuild = await databaseContext.Guilds.SingleByIdAsync(guild.ID, ct);
            
    if (dbGuild is null) // Only add actual new guilds to the database as this fires on ALL guilds during startup
    {
        databaseContext.Guilds.Add(guildModel);
        await databaseContext.SaveChangesAsync(ct);
    } else guildModel = dbGuild;
}

using (var entry = memoryCache.CreateEntry(CacheKey.StringKey($"Guild:{guild.ID}")))
    entry.Value = guildModel;
        
return Result.FromSuccess();

logger.LogInformation("{Availability} Guild {Name} has just been created.", $"{(gatewayEvent.Guild.IsT0 ? "A" : "Una")}vailable", gatewayEvent.Guild.IsT0 ? gatewayEvent.Guild.AsT0.Name : gatewayEvent.Guild.AsT1.ID.ToString());
        
if (gatewayEvent.Guild.IsT1) return Result.FromSuccess();

var guild = gatewayEvent.Guild.AsT0;
var guildModel = new GuildModel(guild, configuration["PREFIX"]!);

await using (var databaseContext = await database.CreateDbContextAsync(ct))
{
    var dbGuild = await databaseContext.Guilds.SingleByIdAsync(guild.ID, ct);
            
    if (dbGuild is null) // Only add actual new guilds to the database as this fires on ALL guilds during startup
    {
        databaseContext.Guilds.Add(guildModel);
        await databaseContext.SaveChangesAsync(ct);
    } else guildModel = dbGuild;
}

using (var entry = memoryCache.CreateEntry(CacheKey.StringKey($"Guild:{guild.ID}")))
    entry.Value = guildModel;
        
return Result.FromSuccess();

-# Exception Trace is attached as .txt file.

Exception_Trace.txt

17 Replies

Sossenbinder•3d ago

Hmm, you're using a pooled dbcontext from what I can read from the stacktrace I suspect the disposal behaviour is connected to that Maybe you can shrink the potential error area by trying a non pooled context first

batiOP•3d ago

Yeah I do have pooling toggled on for my database config

batiOP•3d ago

Here's after disabling pooling:

ExceptionTrace.txt

batiOP•3d ago

Found the trace differences just now

With Pooling

at void Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IResettableService.ResetState()
at void Microsoft.EntityFrameworkCore.Internal.DbContextPool<TContext>.Return(IDbContextPoolable context)
at void Microsoft.EntityFrameworkCore.Internal.DbContextLease.Release()
at void Microsoft.EntityFrameworkCore.Internal.DbContextLease.ContextDisposed()
at void Microsoft.EntityFrameworkCore.DbContext.Dispose()

=================================================================================

Without Pooling

at async Task Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IResettableService.ResetStateAsync(CancellationToken cancellationToken)
at async ValueTask Microsoft.EntityFrameworkCore.Internal.DbContextPool<TContext>.ReturnAsync(IDbContextPoolable context, CancellationToken cancellationToken)
at async ValueTask Microsoft.EntityFrameworkCore.DbContext.DisposeAsync()

With Pooling

at void Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IResettableService.ResetState()
at void Microsoft.EntityFrameworkCore.Internal.DbContextPool<TContext>.Return(IDbContextPoolable context)
at void Microsoft.EntityFrameworkCore.Internal.DbContextLease.Release()
at void Microsoft.EntityFrameworkCore.Internal.DbContextLease.ContextDisposed()
at void Microsoft.EntityFrameworkCore.DbContext.Dispose()

=================================================================================

Without Pooling

at async Task Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IResettableService.ResetStateAsync(CancellationToken cancellationToken)
at async ValueTask Microsoft.EntityFrameworkCore.Internal.DbContextPool<TContext>.ReturnAsync(IDbContextPoolable context, CancellationToken cancellationToken)
at async ValueTask Microsoft.EntityFrameworkCore.DbContext.DisposeAsync()

Sehra•3d ago

did you create a service scope?

Sossenbinder•3d ago

Hm, interesting, looking at https://github.com/dotnet/efcore/blob/main/src/EFCore/Internal/DbContextLease.cs#L111 it does seem like the stacktrace you're going down would only happen for a context which does use pooling. The only way the DbContextLease does use an instance with a pool is from within a pooled factory https://github.com/dotnet/efcore/blob/main/src/EFCore/Infrastructure/PooledDbContextFactory.cs#L69

batiOP•3d ago

I'll go ahead and send how I'm injecting the dbcontext factory

webApplicationBuilder.Services.AddPooledDbContextFactory<SionDbContext>((s, o) => 
{
#if MIGRATION
    const string connectionString = "raw connection string for now";
#else
    var configuration = s.GetRequiredService<IConfigurationRoot>();
    var connectionString = new MySqlConnectionStringBuilder
    {
        Server = configuration["MARIADB_SERVER"] ?? "localhost", 
        Port = uint.Parse(configuration["MARIADB_PORT"] ?? "3306"),
        // Pooling = true,
        Database = configuration["MARIADB_NAME"],
        UserID = configuration["MARIADB_USERNAME"] ?? "root",
        Password = configuration["MARIADB_PASSWORD"]
    }.ConnectionString;
#endif
           
    o.UseMySql(connectionString, new MariaDbServerVersion(ServerVersion.AutoDetect(connectionString)));
    o.UseLoggerFactory(s.GetRequiredService<ILoggerFactory>());
    o.EnableDetailedErrors();
});

webApplicationBuilder.Services.AddPooledDbContextFactory<SionDbContext>((s, o) => 
{
#if MIGRATION
    const string connectionString = "raw connection string for now";
#else
    var configuration = s.GetRequiredService<IConfigurationRoot>();
    var connectionString = new MySqlConnectionStringBuilder
    {
        Server = configuration["MARIADB_SERVER"] ?? "localhost", 
        Port = uint.Parse(configuration["MARIADB_PORT"] ?? "3306"),
        // Pooling = true,
        Database = configuration["MARIADB_NAME"],
        UserID = configuration["MARIADB_USERNAME"] ?? "root",
        Password = configuration["MARIADB_PASSWORD"]
    }.ConnectionString;
#endif
           
    o.UseMySql(connectionString, new MariaDbServerVersion(ServerVersion.AutoDetect(connectionString)));
    o.UseLoggerFactory(s.GetRequiredService<ILoggerFactory>());
    o.EnableDetailedErrors();
});

Ohh I need to use AddDbContextFactory<>() instead

Sehra•3d ago

can you register your responder with DI and ask for a SionDbContext in the constructor?

batiOP•3d ago

As in register the context?

Sehra•3d ago

Sion.Discord.Responders.GuildCreateResponder that one

batiOP•3d ago

That already is registered from another service

Sehra•3d ago

but registered as IResponder<Something>

batiOP•3d ago

Also, my error has been resolved by removing pooling

Sehra•3d ago

ok, cause i was looking at https://github.com/Remora/Remora.Discord/blob/main/Backend/Remora.Discord.Gateway/Services/ResponderDispatchService.cs#L303 and it creates a service scope and resolve responders, so accepting a SionDbContext in your constructor could work

GitHub

Remora.Discord/Backend/Remora.Discord.Gateway/Services/ResponderDis...

A data-oriented C# Discord library, focused on high-performance concurrency and robust design. - Remora/Remora.Discord

batiOP•3d ago

Not with a factory

Sehra•3d ago

no, there wouldn't be a need for factory in that case, it's more for apps that don't deal with service scopes so the lifetime would be handled by the service scope remora creates, and it would be disposed when your responder return

batiOP•3d ago

Ah I see where you're coming from

Gaming

Programming

Cannot access a disposed context instance.

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