module Netplex_shm_manager:sig..end
val post_add_hook : Netplex_types.controller -> unitpost_add_hook of the
componentval init : low:int64 -> high:int64 -> unitmax_int,
and shm_condition always returns `Normal.
When the sum of all allocated shared memory exceeds the high-water
mark, the condition is switched to `Tight. It is switched back
to `Normal when the sum sinks below the low-water mark.