sig
type t
external get : Thread.t -> Unix_ext.Clock.t = "unix_pthread_getcpuclockid"
external get_time : Unix_ext.Clock.t -> float = "unix_clock_gettime"
external set_time : Unix_ext.Clock.t -> float -> unit
= "unix_clock_settime"
external get_resolution : Unix_ext.Clock.t -> float = "unix_clock_getres"
end