Memory leak on MS DI with Disposable Transient

[YZahringer]

I think there is a memory leak with Microsoft Dependency Injection adapter with the Transient disposable types.
I try it with/without MS DI and with/without Disposable type, the memory leak occurs only with MS DI and Disposable type.

Currently we use DryIoc with Prism on Xamarin.Forms multiplatform application. This bug produces a big memory leak, all VM are never released.

static void Main()
{
    // Default Container
    // Disposable: FALSE
    using (var container = new Container())
    {
        container.Register<NotDisposableViewModel>(Reuse.Transient);
        ResolveManyTimes(container, typeof(NotDisposableViewModel));
        Debugger.Break(); // No VM instances in memory 
    }

    // Default Container
    // Disposable: TRUE
    using (var container = new Container(Rules.Default.WithoutThrowOnRegisteringDisposableTransient()))
    {
        container.Register<DisposableViewModel>(Reuse.Transient);
        ResolveManyTimes(container, typeof(DisposableViewModel));
        Debugger.Break(); // No VM instances in memory
    }

    // MS DI Adapter
    // Disposable: FALSE
    using (var container = new Container().WithDependencyInjectionAdapter(new ServiceCollection().AddTransient<NotDisposableViewModel>()))
    {
        ResolveManyTimes(container, typeof(NotDisposableViewModel));
        Debugger.Break(); // No VM instances in memory
    }

    // MS DI Adapter
    // Disposable: TRUE
    using (var container = new Container().WithDependencyInjectionAdapter(new ServiceCollection().AddTransient<DisposableViewModel>()))
    {
        ResolveManyTimes(container, typeof(DisposableViewModel));
        Debugger.Break(); // 100 VM instances in memory (MEMORY LEAK!!!)
    }

    // MS DI Adapter with Scope
    // Disposable: TRUE
    using (var container = new Container().WithDependencyInjectionAdapter(new ServiceCollection().AddTransient<DisposableViewModel>()))
    {
        using (var scope = container.OpenScope())
        {
            ResolveManyTimes(scope, typeof(DisposableViewModel));
        }
        Debugger.Break(); // No VM instances in memory
    }

    // MS DI Adapter and Register on Default Container
    // Disposable: TRUE
    using (var container = new Container().WithDependencyInjectionAdapter(new ServiceCollection()))
    {
        container.Register<DisposableViewModel>(Reuse.Transient);
        ResolveManyTimes(container, typeof(DisposableViewModel));
        Debugger.Break(); // 100 VM instances in memory (MEMORY LEAK!!!)
    }

    Console.Read();
}

private static void ResolveManyTimes(IResolver container, Type typeToResolve)
{
    for (var i = 0; i < 100; i++)
    {
        container.Resolve(typeToResolve);
    }
}

internal class NotDisposableViewModel
{

}

internal class DisposableViewModel : IDisposable
{
    public void Dispose()
    {
    
    }
}

Output from VS Memory Analyzer:

[dadhi]

@YZahringer Hi, thanks for the interesting observation and detailed repros.

The problem is known and is laying in MS.DI rules including WithTrackingDisposableTransients, so the disposable transients will be stored in the nearest scope or in the container singleton scope until either scope or container is disposed.

You may suppress the rule applying the WithoutTrackingDisposableTransients() after the WithDependencyInjectionAdapter(...), or you may change the Transient for something else to be more explicit about VM lifetime.

[YZahringer]

@dadhi Thanks for the quick answer. I can't find the WithoutTrackingDisposableTransients() method, only WithTrackingDisposableTransients is available.

This one is missing or planned for a future release?
Is there another way to remove this rule without this method?

[dadhi]

I cannot find WithoutTrackingDisposableTransients

Then let's add it.
There also a wrong api-doc on WithTracking... counterpart.
Plus let's document the MS.DI rules and important consequences.

[SeriousM]

I also have a memoryleak and I suspect that MS.DI is a vital part in my story but wasn't able to verify it yet.
What is the downside of WithoutTrackingDisposableTransients in combination with MS.DI?

[dadhi]

@SeriousM Likely, yes. Fix will be soon.

[dadhi]

Added the WithoutTrackingDisposableTransients, corrected the docs, documented the rule list and released the v4.8.2