private void Unsubscribe(SubjectDisposable observer)
{
for (; ;)
{
var a = Volatile.Read(ref _observers);
var n = a.Length;
if (n == 0)
{
break;
}
var j = Array.IndexOf(a, observer);
if (j < 0)
{
break;
}
SubjectDisposable[] b;
if (n == 1)
{
b = Array.Empty <SubjectDisposable>();
}
else
{
b = new SubjectDisposable[n - 1];
Array.Copy(a, 0, b, 0, j);
Array.Copy(a, j + 1, b, j, n - j - 1);
}
if (Interlocked.CompareExchange(ref _observers, b, a) == a)
{
break;
}
}
}
/// <summary>
/// Subscribes an observer to the subject.
/// </summary>
/// <param name="observer">Observer to subscribe to the subject.</param>
/// <returns>Disposable object that can be used to unsubscribe the observer from the subject.</returns>
/// <exception cref="ArgumentNullException"><paramref name="observer"/> is null.</exception>
public override IDisposable Subscribe(IObserver <T> observer)
{
if (null == observer)
{
throw new ArgumentNullException(nameof(observer));
}
var disposable = default(SubjectDisposable);
for (; ;)
{
var subscribers = Volatile.Read(ref observers);
if (subscribers == DISPOSED)
{
exception = null;
ThrowDisposed();
break;
}
if (subscribers == TERMINATED)
{
var ex = exception;
if (ex != null)
{
observer.OnError(ex);
}
else
{
observer.OnCompleted();
}
break;
}
if (disposable == null)
{
disposable = new SubjectDisposable(this, observer);
}
var n = subscribers.Length;
var b = new SubjectDisposable[n + 1];
Array.Copy(subscribers, 0, b, 0, n);
b[n] = disposable;
if (Interlocked.CompareExchange(ref observers, b, subscribers) == subscribers)
{
return(disposable);
}
}
return(Disposable.Empty);
}
public IDisposable Subscribe(IObserver <T> observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
var disposable = default(SubjectDisposable);
for (; ;)
{
var observers = Volatile.Read(ref _observers);
if (observers == Disposed)
{
_exception = null;
ThrowDisposed();
break;
}
if (observers == Terminated)
{
var ex = _exception;
if (ex != null)
{
observer.OnError(ex);
}
else
{
observer.OnCompleted();
}
break;
}
disposable ??= new SubjectDisposable(this, observer);
var n = observers.Length;
var b = new SubjectDisposable[n + 1];
Array.Copy(observers, 0, b, 0, n);
b[n] = disposable;
if (Interlocked.CompareExchange(ref _observers, b, observers) == observers)
{
return(disposable);
}
}
return(Disposable.Empty);
}
