splat: [BUG] Splat.Microsoft.Extensions.DependencyInjection causes System.InvalidOperationException: Call from invalid thread

Just trying to put together Avalonia’s routing sample and Splat.Microsoft.Extensions.DependencyInjection. Pressing Go next button throws the exception below when Splat.Microsoft.Extensions.DependencyInjection is used. Works fine if services.UseMicrosoftDependencyResolver(); is commented out.

Repro: AvaRxUI.zip

System.InvalidOperationException: Call from invalid thread
   at Avalonia.Threading.Dispatcher.<VerifyAccess>g__ThrowVerifyAccess|16_0() in /_/src/Avalonia.Base/Threading/Dispatcher.cs:line 77
   at Avalonia.Threading.Dispatcher.VerifyAccess() in /_/src/Avalonia.Base/Threading/Dispatcher.cs:line 78
   at Avalonia.AvaloniaObject.VerifyAccess() in /_/src/Avalonia.Base/AvaloniaObject.cs:line 111
   at Avalonia.AvaloniaObject.GetValue[T](StyledProperty`1 property) in /_/src/Avalonia.Base/AvaloniaObject.cs:line 226
   at Avalonia.Controls.Button.get_Command() in /_/src/Avalonia.Controls/Button.cs:line 138
   at Avalonia.Controls.Button.CanExecuteChanged(Object sender, EventArgs e) in /_/src/Avalonia.Controls/Button.cs:line 560
   at ReactiveUI.ReactiveCommandBase`2.OnCanExecuteChanged(Boolean newValue) in /_/src/ReactiveUI/ReactiveCommand/ReactiveCommandBase.cs:line 219
   at System.Reactive.AnonymousSafeObserver`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/AnonymousSafeObserver.cs:line 43
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.IdentitySink`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Internal/IdentitySink.cs:line 15
   at System.Reactive.Subjects.FastImmediateObserver`1.EnsureActive(Int32 count) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 863
   at System.Reactive.Subjects.FastImmediateObserver`1.EnsureActive() in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 765
   at System.Reactive.Subjects.ReplaySubject`1.ReplayBase.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 270
   at System.Reactive.Subjects.ReplaySubject`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 161
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.IdentitySink`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Internal/IdentitySink.cs:line 15
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.Linq.ObservableImpl.DistinctUntilChanged`2._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/DistinctUntilChanged.cs:line 72
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.Linq.ObservableImpl.CombineLatest`3._.SecondObserver.OnNext(TSecond value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/CombineLatest.cs:line 177
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.IdentitySink`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Internal/IdentitySink.cs:line 15
   at System.Reactive.Subjects.FastImmediateObserver`1.EnsureActive(Int32 count) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 863
   at System.Reactive.Subjects.FastImmediateObserver`1.EnsureActive() in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 765
   at System.Reactive.Subjects.ReplaySubject`1.ReplayBase.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 270
   at System.Reactive.Subjects.ReplaySubject`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Subjects/ReplaySubject.cs:line 161
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.IdentitySink`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Internal/IdentitySink.cs:line 15
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.Linq.ObservableImpl.DistinctUntilChanged`2._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/DistinctUntilChanged.cs:line 72
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.IdentitySink`1.OnNext(T value) in /_/Rx.NET/Source/src/System.Reactive/Internal/IdentitySink.cs:line 15
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.Linq.ObservableImpl.Select`2.Selector._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/Select.cs:line 47
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.Linq.ObservableImpl.Scan`2._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/Scan.cs:line 48
   at System.Reactive.SafeObserver`1.WrappingSafeObserver.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Internal/SafeObserver.cs:line 30
   at System.Reactive.Sink`1.ForwardOnNext(TTarget value) in /_/Rx.NET/Source/src/System.Reactive/Internal/Sink.cs:line 49
   at System.Reactive.ObserveOnObserverLongRunning`1.Drain() in /_/Rx.NET/Source/src/System.Reactive/Internal/ScheduledObserver.cs:line 732
   at System.Reactive.ObserveOnObserverLongRunning`1.<>c.<.cctor>b__17_0(ObserveOnObserverLongRunning`1 self, ICancelable cancelable) in /_/Rx.NET/Source/src/System.Reactive/Internal/ScheduledObserver.cs:line 680
   at System.Reactive.Concurrency.DefaultScheduler.LongRunning.LongScheduledWorkItem`1.<>c.<.ctor>b__3_0(Object thisObject) in /_/Rx.NET/Source/src/System.Reactive/Concurrency/DefaultScheduler.cs:line 181
   at System.Reactive.Concurrency.ConcurrencyAbstractionLayerImpl.<>c.<StartThread>b__8_0(Object itemObject) in /_/Rx.NET/Source/src/System.Reactive/Concurrency/ConcurrencyAbstractionLayerImpl.cs:line 75

About this issue

Original URL
State: closed
Created a year ago
Comments: 16 (11 by maintainers)

Most upvoted comments

The end Splat packages will be a single alternative package for Avalonia and not an additional one, and be an extension of the existing code with a single dll.

RxApp.MainThreadScheduler should be set to AvaloniaScheduler.Instance and is done in the UseReactiveUI section of Avalonia.ReactiveUI, however when initialisation of Splat with the new DI occurs the RxApp.MainThreadScheduler is reset causing the issue you experienced. We will need to document the order in which the AppBuilder extensions are added in order to ensure that things are initialised in the correct order. I will most likely wrap the UseReactiveUI inside the extension to be certain it’s done in the right order. Something like UseReactiveUiWithDryIoc(container => {})

ChrisPulman on Jul 20, 2023