The yahns HTTP server uses a long-lived fdmap array to map
Fixnum(fileno) -> IO connections.
This array exists prevent GC from sweeping IOs (because IOs are watched
by Linux epoll and not markable w/o an Array to store them).

64K+ connections (array size) is attainable with yahns.  The long-lived
fdmap array lifetime should not infect the short lived client
connections.

If I were to allow >=64K client connections on my public yahns instance,
clients will cause memory leaks/waste.

(yahns supports infinitely-lived connections, but in
 practice, clients connections tend to be short-lived).