Exception on IHostApplicationLifetime.StopApplication()

[Leon99]

xxx type only implements IAsyncDisposable. Use DisposeAsync to dispose the container. is thrown on calling IHostApplicationLifetime.StopApplication() if there's a service in the container that implements IAsyncDisposable but not IDisposable. Any ideas how to deal with it (other than calling DisposeAsync().GetAwaiter().GetResult(); from Dispose(), which may lead to a deadlock)? I suspect having IHostApplicationLifetime.StopApplicationAsync() could help, but it doesn't exist.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[ghost]

Tagging subscribers to this area: @eerhardt, @maryamariyan
See info in area-owners.md if you want to be subscribed.

Issue Details

---

xxx type only implements IAsyncDisposable. Use DisposeAsync to dispose the container. is thrown on calling IHostApplicationLifetime.StopApplication() if there's a service in the container that implements IAsyncDisposable but not IDisposable. Any ideas how to deal with it (other than calling DisposeAsync().GetAwaiter().GetResult(); from Dispose(), of course)? I suspect having IHostApplicationLifetime.StopApplicationAsync() could help, but it doesn't exist.

Author:	Leon99
Assignees:	-
Labels:	area-Extensions-Hosting, untriaged
Milestone:	-

[davidfowl]

Can you show the stack trace? Where are disposing the host from?

[Leon99]

This exception was originally thrown at this call stack:
    Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.Dispose()
    Cli.CrawlService.StartAsync(System.Threading.CancellationToken) in CrawlService.cs
    System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
    System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(System.Threading.Tasks.Task)
    Microsoft.Extensions.Hosting.Internal.Host.StartAsync(System.Threading.CancellationToken)
    System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
    System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(System.Threading.Tasks.Task)
    System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(System.Threading.Tasks.Task)
    System.Runtime.CompilerServices.ConfiguredTaskAwaitable.ConfiguredTaskAwaiter.GetResult()
    Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(Microsoft.Extensions.Hosting.IHost, System.Threading.CancellationToken)
    ...
    [Call Stack Truncated]

[davidfowl]

In the CrawlService, are you making a custom service scope and calling Dispose instead of DisposeAsync? Why?

[Leon99]

Hmm, looking at that stack - it's not exactly what I saw initially, I changed the code significantly since then but didn't save the stack trace (shame on me) and now I just tried to reproduce it. Initially, it was failing on StopApplication(), although it's on the last line in that method... Anyway, to answer your question - I don't call Dispose explicitly, but I do using var scope = _serviceScopeFactory.CreateScope(); and then resolve the service from that scope.

[davidfowl]

Unfortunately, the workaround for this is a big ugly:

public static class ServiceScopeExtensions
{
    public static AsyncServiceScope CreateAsyncServiceScope(this IServiceProvider serviceProvider)
    {
        return new AsyncServiceScope(serviceProvider.CreateScope());
    }
}

public struct AsyncServiceScope : IServiceScope, IAsyncDisposable
{
    private readonly IServiceScope _serviceScope;

    public AsyncServiceScope(IServiceScope serviceScope)
    {
        _serviceScope = serviceScope;
    }

    public IServiceProvider ServiceProvider => _serviceScope.ServiceProvider;

    public void Dispose()
    {
        _serviceScope.Dispose();
    }

    public ValueTask DisposeAsync()
    {
        if (_serviceScope is IAsyncDisposable ad)
        {
            return ad.DisposeAsync();
        }
        _serviceScope.Dispose();
        return ValueTask.CompletedTask;
    }
}

Then you can change your code to do this:

await using var scope = _serviceProvider.CreateAsyncServiceScope();

[davidfowl]

See #43970 for more information.

[davidfowl]

Closing this one