<PackageReference Include="System.Reactive" Version="4.1.2" />

CombineLatest<TFirst, TSecond, TResult>

sealed class CombineLatest<TFirst, TSecond, TResult> : Producer<TResult, _<TFirst, TSecond, TResult>>
using System.Reactive.Disposables; namespace System.Reactive.Linq.ObservableImpl { internal sealed class CombineLatest<TFirst, TSecond, TResult> : Producer<TResult, CombineLatest<TFirst, TSecond, TResult>._> { internal sealed class _ : IdentitySink<TResult> { private sealed class FirstObserver : IObserver<TFirst> { private readonly _ _parent; private SecondObserver _other; public SecondObserver Other { set { _other = value; } } public bool HasValue { get; set; } public TFirst Value { get; set; } public bool Done { get; set; } public FirstObserver(_ parent) { _parent = parent; } public void OnNext(TFirst value) { lock (_parent._gate) { HasValue = true; Value = value; if (_other.HasValue) { TResult val = default(TResult); try { val = _parent._resultSelector(value, _other.Value); } catch (Exception error) { _parent.ForwardOnError(error); return; } _parent.ForwardOnNext(val); } else if (_other.Done) { _parent.ForwardOnCompleted(); } } } public void OnError(Exception error) { lock (_parent._gate) { _parent.ForwardOnError(error); } } public void OnCompleted() { lock (_parent._gate) { Done = true; if (_other.Done) _parent.ForwardOnCompleted(); else Disposable.TryDispose(ref _parent._firstDisposable); } } } private sealed class SecondObserver : IObserver<TSecond> { private readonly _ _parent; private FirstObserver _other; public FirstObserver Other { set { _other = value; } } public bool HasValue { get; set; } public TSecond Value { get; set; } public bool Done { get; set; } public SecondObserver(_ parent) { _parent = parent; } public void OnNext(TSecond value) { lock (_parent._gate) { HasValue = true; Value = value; if (_other.HasValue) { TResult val = default(TResult); try { val = _parent._resultSelector(_other.Value, value); } catch (Exception error) { _parent.ForwardOnError(error); return; } _parent.ForwardOnNext(val); } else if (_other.Done) { _parent.ForwardOnCompleted(); } } } public void OnError(Exception error) { lock (_parent._gate) { _parent.ForwardOnError(error); } } public void OnCompleted() { lock (_parent._gate) { Done = true; if (_other.Done) _parent.ForwardOnCompleted(); else Disposable.TryDispose(ref _parent._secondDisposable); } } } private readonly Func<TFirst, TSecond, TResult> _resultSelector; private object _gate; private IDisposable _firstDisposable; private IDisposable _secondDisposable; public _(Func<TFirst, TSecond, TResult> resultSelector, IObserver<TResult> observer) : base(observer) { _resultSelector = resultSelector; } public void Run(IObservable<TFirst> first, IObservable<TSecond> second) { _gate = new object(); FirstObserver firstObserver = new FirstObserver(this); SecondObserver secondObserver2 = firstObserver.Other = new SecondObserver(this); secondObserver2.Other = firstObserver; Disposable.SetSingle(ref _firstDisposable, ObservableExtensions.SubscribeSafe<TFirst>(first, (IObserver<TFirst>)firstObserver)); Disposable.SetSingle(ref _secondDisposable, ObservableExtensions.SubscribeSafe<TSecond>(second, (IObserver<TSecond>)secondObserver2)); } protected override void Dispose(bool disposing) { if (disposing) { Disposable.TryDispose(ref _firstDisposable); Disposable.TryDispose(ref _secondDisposable); } base.Dispose(disposing); } } private readonly IObservable<TFirst> _first; private readonly IObservable<TSecond> _second; private readonly Func<TFirst, TSecond, TResult> _resultSelector; public CombineLatest(IObservable<TFirst> first, IObservable<TSecond> second, Func<TFirst, TSecond, TResult> resultSelector) { _first = first; _second = second; _resultSelector = resultSelector; } protected override _ CreateSink(IObserver<TResult> observer) { return new _(_resultSelector, observer); } protected override void Run(_ sink) { sink.Run(_first, _second); } } }