Improved Approach To Limiting Asynchronous Calls with Rx

gistfile1.cs

Action<IList<XElement>> saveAction = SaveChunk;
var loader = new BulkPostLoader(@"e:\stackoverflow\062010 so\posts.xml");
var batches = loader.BufferWithCount(5000);
var results = batches.Select(x => saveAction.BeginInvoke(x, null, null));
        
results
    .Aggregate(new HashSet<IAsyncResult>(), (set, result) =>
    {
        set.RemoveWhere(x => x.IsCompleted);
        set.Add(result);
        if(set.Count > 5)
        {
            var inProcess = set.Where(x => !x.IsCompleted).FirstOrDefault();
            if(inProcess != null)
            {
                inProcess.AsyncWaitHandle.WaitOne();
            }
        }
        return set;
    }
    .Subscribe(x => {});