Tick.Make_poweroff

Best-effort, program poweroff resistant, monotonic, clock tick watchers.

Given a watcher w:

If there is no Tick.LIFECYCLE.suspend event while Tick.WATCHER.waiting w is true, the value of Tick.WATCHER.linger_ns w is an accurate and exact wall-clock time span.
If there is one or more pairs of Tick.LIFECYCLE.suspend and Tick.LIFECYCLE.resume events while Tick.WATCHER.waiting w is true and that the difference between the value of Tick.PCLOCK.now_d_ps at these events provides an accurate measure of the actual wall-clock time span that elapsed during suspension, the value of Tick.WATCHER.linger_ns w is an accurate and exact wall-clock time span.
This condition is typically satisfied if Tick.PCLOCK is well synchronized at Tick.LIFECYCLE.suspend and Tick.LIFECYCLE.resume and no leap second occurs between these two events. The absolute value of Tick.PCLOCK doesn't matter.
If there is one or more pairs of Tick.LIFECYCLE.poweroff and Tick.LIFECYCLE.poweron events and that the difference between the value of Tick.PCLOCK.now_d_ps at these events provides an accurate measure of the actual wall-clock time span that elapsed during the poweroff, the value of Tick.WATCHER.linger_ns w is an accurate and exact wall-clock time span.
This condition is typically satisfied if Tick.PCLOCK is well synchronized at Tick.LIFECYCLE.poweroff and Tick.LIFECYCLE.poweron and no leap second occurs between these two events. The absolute value of Tick.PCLOCK doesn't matter.

In this interface triggers can be persisted. Note that trigger actuation occurs through the Tick.PERSISTENT_TRIGGER interface.

The type for positive nanoseconds time spans. This is an unsigned 64-bit integer it can represent time spans up to approximatevley 584 Julian years.

The type for tick watcher triggers. This is the value being acted upon when a watcher sees a tick.

The type for tick watchers. Encapsulate a delay to watch for and a trigger to actuate whenever the delay elapsed.

watch d tr is a tick in that occurs after d nanoseconds and is watched by trigger tr.

unwatch w unwatches the tick in w. If w is no longer Tick.WATCHER.waiting this has no effect. Otherwise w's trigger is guaranteed not to be actuated and Tick.WATCHER.waiting w becomes false.

waiting w is true iff w's trigger has not been actuated yet or w was not Tick.WATCHER.unwatched.

linger_ns w is the number of nanoseconds during which Tick.WATCHER.waiting w was true. If w's trigger was actuated then:

linger_ns w < delay_ns w the tick was in advance.
linger_ns w = delay_ns w the tick was on time.
linger_ns w > delay_ns w the tick was late.

delay_ns w is w's waiting delay.

trigger w is w's trigger.

fold f acc folds over all watchers that have Tick.WATCHER.waiting t = true.

Functor Tick.Make_poweroff_resistant

Tick watchers