+ high then lower it. It starts at -1 (==infinite). */
+/* Note that beforepoll_fn may NOT do anything which might change the
+ fds or timeouts wanted by other registered poll loop loopers.
+ Callers should make sure of this by not making any calls into other
+ modules from the beforepoll_fn; the easiest way to ensure this is
+ for beforepoll_fn to only retreive information and not take any
+ action.
+ */