Does Parallel.ForEach Block?

Question

Does the .net function Parallel.ForEach block the calling thread? My guess as to the behavior is one of these:

1. Yes, it blocks until the slowest item executing

Answer 1

Number 1 is correct; Parallel.ForEach does not return until the loop has completed. If you don't want that behavior, you can simply execute your loop as a Task and run it on another thread.