Wait until a BlockingCollection queue is cleared by a background thread, with a timeout if it takes too long?

Question

In C#, I'm wondering if it's possible to wait until a BlockingCollection is cleared by a background thread, with a timeout if it takes too long.

The temporary code that I have at the moment strikes me as somewhat inelegant (since when is it good practice to use Thread.Sleep?):

while (_blockingCollection.Count > 0 || !_blockingCollection.IsAddingCompleted)
{
    Thread.Sleep(TimeSpan.FromMilliseconds(20));
    // [extra code to break if it takes too long]
}

Answer 1

What if you write something like this in your consuming thread:

var timeout = TimeSpan.FromMilliseconds(10000);
T item;
while (_blockingCollection.TryTake(out item, timeout))
{
     // do something with item
}
// If we end here. Either we have a timeout or we are out of items.
if (!_blockingCollection.IsAddingCompleted)
   throw MyTimeoutException();