void DisposeImpl()
{
var y = _yielder;
if (y != null)
{
y.Break();
_yielder = null;
}
// Let the task finish on its own
_task = null;
}
public async Task <bool> MoveNext(CancellationToken cancellationToken)
{
if (_task != null)
{
// Second MoveNext() call. Tell Yielder to let the function continue.
_yielder.CancellationToken = cancellationToken;
_yielder.Continue();
}
else
{
if (_func == null)
{
throw new AsyncYielderDisposedException();
}
// First MoveNext() call. Start the task.
_yielder = new AsyncYielder <T>();
_yielder.CancellationToken = cancellationToken;
_task = _func(_yielder);
_func = null;
}
// Wait for yield or return.
Task finished = await Task.WhenAny(_task, _yielder.YieldTask).ConfigureAwait(false);
var y = _yielder;
if (finished != _task && y != null)
{
// the function returned a result.
Current = y.YieldTask.Result;
return(true);
}
// The operation is finished.
Task t = _task;
_yielder = null;
_task = null;
if (t != null && t.IsFaulted)
{
throw t.Exception;
}
return(false);
}