Monitoring progress in Parallel.ForEach every minute

Question

I'm using Parallel.ForEach to download 500K URLs and I want to monitor the number of URLs that have been successfully downloaded each minute.

 int elapsedMinutes = 0, cnt = 0;
 Parallel.ForEach(list, tuple =>
 {
 var currMinutes = (int) ((DateTime.Now - startTime).TotalMinutes);
 lock (Object)
 {
 if (currMinutes > elapsedMinutes)
 {
 elapsedMinutes = currMinutes;
 Console.WriteLine("{0}: Extracted {1} urls", DateTime.Now, cnt);
 }
 }
 //download urls ...
 Interlocked.Increment(ref cnt);
 });

It looks fine now but the lock statement part seems a bit ugly to me. Is there a better way to achieve this?

Answer 1

Instead of checking the time from each thread on each iteration, I would use a Timer:

int count = 0;
TimeSpan reportPeriod = TimeSpan.FromMinutes(0.1);
using (new Timer(
 _ => Console.WriteLine("{0}: Extracted {1} urls", DateTime.Now, count),
 null, reportPeriod, reportPeriod))
{
 Parallel.ForEach(
 list, tuple =>
 {
 //download urls ...
 Interlocked.Increment(ref count);
 });
}
Console.WriteLine("{0}: Done", DateTime.Now);

I have also renamed cnt to count, those two characters are not worth it to make your code less readable.