using System.Reactive.Disposables; using System.Threading; namespace System.Reactive.Linq.ObservableImpl { internal sealed class Catch<TSource, TException> : Producer<TSource, Catch<TSource, TException>._> where TException : Exception { internal sealed class _ : IdentitySink<TSource> { private readonly Func<TException, IObservable<TSource>> _handler; private bool _once; private IDisposable _subscription; public _(Func<TException, IObservable<TSource>> handler, IObserver<TSource> observer) : base(observer) { _handler = handler; } public override void Run(IObservable<TSource> source) { Disposable.TrySetSingle(ref _subscription, ObservableExtensions.SubscribeSafe<TSource>(source, (IObserver<TSource>)this)); } protected override void Dispose(bool disposing) { if (disposing) Disposable.TryDispose(ref _subscription); base.Dispose(disposing); } public override void OnError(Exception error) { if (!Volatile.Read(ref _once)) { TException val = error as TException; if (val != null) { IObservable<TSource> observable = null; try { observable = _handler(val); } catch (Exception error2) { ForwardOnError(error2); return; } Volatile.Write(ref _once, true); Disposable.TrySetSerial(ref _subscription, ObservableExtensions.SubscribeSafe<TSource>(observable, (IObserver<TSource>)this)); return; } } ForwardOnError(error); } } private readonly IObservable<TSource> _source; private readonly Func<TException, IObservable<TSource>> _handler; public Catch(IObservable<TSource> source, Func<TException, IObservable<TSource>> handler) { _source = source; _handler = handler; } protected override _ CreateSink(IObserver<TSource> observer) { return new _(_handler, observer); } protected override void Run(_ sink) { sink.Run(_source); } } }