What should be a Parallel.For equivalent of this loop

Question

I have this sequential loop in vb.net.

For i As Integer = 0 To 615 Step 15
    DownloadSingleFile(i)
Next

The "Step 15" part in the loop is important. I'm unable to figure out a parallel substitute for this code.

I tried the below code, but it is missing the "Step 15" part.

Parallel.For(0, 615, Sub(i)
                 DownloadSingleFile(i)
                     End Sub)

Please help.

possible duplicate of [Parallelizing a for loop with stepping in .net 4.5](http://stackoverflow.com/questions/13593342/parallelizing-a-for-loop-with-stepping-in-net-4-5) — , Sep 24 '14 at 15:59

score 4 · Accepted Answer · edited Sep 24 '14 at 16:13

4

This should do the same:

42 (exclusive) = ((615 / 15) + 1)

Parallel.For(0, 42, Sub(i)
      DownloadSingleFile(i * 15)
 End Sub)

edited Sep 24 '14 at 16:13

answered Sep 24 '14 at 15:05

Allan S. Hansen

I cannot believe I missed your answer. Anyhow, I deleted mine, and updated yours. – Bjørn-Roger Kringsjå Sep 24 '14 at 16:16
+1. Another suggestion is to use Enumerable.Range http://stackoverflow.com/questions/14045112/parallel-for-using-step-1. – Victor Zakharov Sep 24 '14 at 17:30
@AllanS.Hansen I know you'd do the same for me;) – Bjørn-Roger Kringsjå Sep 25 '14 at 06:06

1 Answers1