Module std::time

Time as an effect: code reads the clock and waits on it only through a Clock capability in its row, so its caller decides which clock it reads. Every executor (std::task::Pool, std::net::Evented) handles it with the monotonic clock in nanoseconds; a test uses std::sim::SimClock or the virtual time of std::sim::world.

Source: std/time.weir; committed interface: std/time.iface. Index

• effect Clock: Reading the time and waiting: handled by every executor, or by std::sim::SimClock alone.

effect Clock

pub effect Clock {
    fn now() -> Int;
    once fn sleep(d: Int);
}

Reading the time and waiting: handled by every executor, or by std::sim::SimClock alone.

op now

fn now() -> Int;

Control kind tail: the clause's result is the op's, and the performer goes on, never aborted or suspended.

The current time, in ticks of the handler's choosing (nanoseconds on a real executor).

op sleep

once fn sleep(d: Int);

Control kind once: the clause takes the continuation (cont k) and resumes or cancels it, so the perform is a suspension and an abort edge.

Waits until d ticks have passed (none when d is not positive). A once op: an executor parks the task and runs others meanwhile; a clock that runs no tasks answers at once.