Wait for pooled threads to complete

Question

I\'m sorry for a redundant question. However, I\'ve found many solutions to my problem but none of them are very well explained. I\'m hoping that it will be made clear, he

Answer 1

Here is a solution using the CountdownEvent class.

var complete = new CountdownEvent(1);
foreach (var o in collection)
{
  var capture = o;
  ThreadPool.QueueUserWorkItem((state) =>
    {
      try
      {
        DoSomething(capture);
      }
      finally
      {
        complete.Signal();
      }
    }, null);
}
complete.Signal();
complete.Wait();

Of course, if you have access to the CountdownEvent class then you have the whole TPL to work with. The Parallel class takes care of the waiting for you.

Parallel.ForEach(collection, o =>
  {
    DoSomething(o);
  });