using System.Runtime.CompilerServices; namespace System.Reactive { [System.Runtime.CompilerServices.NullableContext(1)] [System.Runtime.CompilerServices.Nullable(new byte[] { 0, 1 })] internal sealed class SynchronizedObserver<[System.Runtime.CompilerServices.Nullable(2)] T> : ObserverBase<T> { private readonly object _gate; private readonly IObserver<T> _observer; public SynchronizedObserver(IObserver<T> observer, object gate) { _gate = gate; _observer = observer; } protected override void OnNextCore(T value) { lock (_gate) { _observer.OnNext(value); } } protected override void OnErrorCore(Exception exception) { lock (_gate) { _observer.OnError(exception); } } protected override void OnCompletedCore() { lock (_gate) { _observer.OnCompleted(); } } } }