Where are the missing requests?

[Viktor Dukhovni]

When I run "unbound-control dump_requestlist", I consistently see
fewer requests output than I'd expect:

    # (unbound-control stats_noreset | grep 'requestlist.current.user'; unbound-control dump_requestlist | wc -l)
    thread0.requestlist.current.user=272
    thread1.requestlist.current.user=225
    total.requestlist.current.user=497
	 286

    # (unbound-control stats_noreset | grep 'requestlist.current.user'; unbound-control dump_requestlist | wc -l)
    thread0.requestlist.current.user=283
    thread1.requestlist.current.user=206
    total.requestlist.current.user=489
	 303

    # (unbound-control stats_noreset | grep 'requestlist.current.user'; unbound-control dump_requestlist | wc -l)
    thread0.requestlist.current.user=272
    thread1.requestlist.current.user=219
    total.requestlist.current.user=491
	 300

As you can see above, the request list has ~500 entries, but only
~300 are returned by dump_requestlist.  Is this an artefact of some
sort of lossy list traversal?  Are requests completing too fast to
be captured by dump_requestlist?

-- 
	Viktor.