I'm trying to download a list of files (using reactive extensions), maintaining maximum TWO parallel downloads at a time.
So far I didn't come across a working sample.
The closest thing so far is :
How can I limit Parallel.ForEach?
But I want to do the same that via Rx.net Any help would be really appreciated.
Observable.Merge takes a maxConcurrent argument which lets you limit how many parallel subscriptions are maintained. So you can do something like this:
public class DownloadResult { /*...*/ } public Task<DownloadResult> DownloadFileAsync(string path) { /*...*/ } public IObservable<DownloadResult> DownloadFiles(int maxConcurrent, string[] paths) { return paths .Select(path => Observable.FromAsync(() => DownloadFileAsync(path))) .Merge(maxConcurrent: maxConcurrent); } 
DownloadAsync isnt really async. Never new a Task. Use Task.Run instead. Or declare your method async and get rid of the Task construction and use await Task.Delay(1000); instead of Sleep