This would synchronize the downloading of the many small files, so it would behave like downloading with a single thread. This way the concurrent scenario of the poller to support many small files wouldn't optimize network usage, it only would require more threads without any benefit. Is this concurrent poller scenario really useful? Probably in most cases different ftpSources have to be handled, these should be polled concurrently, but I don't see a real case for the same FTPSource polled concurrently. I am not sure, if this was the intention by ramkris.Reading your comment though I'm wondering if maybe just synchronising receive() would be good enough for now?