A GC alarm calls a user function after the end of each major GC cycle.
include sig ... endval sexp_of_t : t ‑> Base.Sexp.tval create : (unit ‑> unit) ‑> tcreate f arranges for f to be called after the end of each major GC cycle,
starting with the current cycle or the next one. f will be run in the monitor
that create was called in.
val delete : t ‑> unitdelete t will stop the calls to the function associated with t. Calling delete
t again has no effect.