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Module Clock

Signature

include Async_kernel.Clock_intf.Clock with module Time := Core.Std.Time
module Time : sig .. end
val run_at : Time.t -> ('a -> unit) -> 'a -> unit

run_at time f a runs f a as soon as possible after time. If time is in the past, then run_at will immediately schedule a job t that will run f a. In no situation will run_at actually call f itself. The call to f will always be in another job.

run_after is like run_at, except that one specifies a time span rather than an absolute time.

val run_after : Time.Span.t -> ('a -> unit) -> 'a -> unit
val at : Time.t -> unit Async_kernel.Deferred.t

at time returns a deferred d that will become determined as soon as possible after time

after is like at, except that one specifies a time span rather than an absolute time.

If you set up a lot of after events at the beginning of your program they will trigger at the same time. Use Time.Span.randomize to even that out.

val after : Time.Span.t -> unit Async_kernel.Deferred.t
val with_timeout : Time.Span.t -> 'a Async_kernel.Deferred.t -> [
| `Timeout
| `Result of 'a
] Async_kernel.Deferred.t

with_timeout span d does pretty much what one would expect. Note that at the point of checking if d is determined and the timeout has expired, the resulting deferred will be determined with `Result. In other words, since there is an inherent race between d and the timeout, preference is given to d.

module Event : sig .. end
Events provide variants of run_at and run_after with the ability to abort or reschedule an event that hasn't yet happened.
val at_varying_intervals : ?stop:unit Async_kernel.Deferred.t -> (unit -> Time.Span.t) -> unit Async_kernel.Async_stream.t

at_varying_intervals f ?stop returns a stream whose next element becomes determined by calling f () and waiting for that amount of time, and then looping to determine subsequent elements. The stream will end after stop becomes determined.

val at_intervals : ?start:Time.t -> ?stop:unit Async_kernel.Deferred.t -> Time.Span.t -> unit Async_kernel.Async_stream.t

at_intervals interval ?start ?stop returns a stream whose elements will become determined at nonnegative integer multiples of interval after the start time, until stop becomes determined:

        start + 0 * interval
        start + 1 * interval
        start + 2 * interval
        start + 3 * interval
        ...

If the interval is too small or the CPU is too loaded, at_intervals will skip until the next upcoming multiple of interval after start.

val every' : ?start:unit Async_kernel.Deferred.t -> ?stop:unit Async_kernel.Deferred.t -> ?continue_on_error:bool -> Time.Span.t -> (unit -> unit Async_kernel.Deferred.t) -> unit

every' ?start ?stop span f runs f () every span amount of time starting when start becomes determined and stopping when stop becomes determined. every waits until the result of f () becomes determined before waiting for the next span.

It is guaranteed that if stop becomes determined, even during evaluation of f, then f will not be called again by a subsequent iteration of the loop.

It is an error for span to be nonpositive.

With ~continue_on_error:true, when f asynchronously raises, iteration continues. With ~continue_on_error:false, if f asynchronously raises, then iteration only continues when the result of f becomes determined.

Exceptions raised by f are always sent to monitor in effect when every' was called, even with ~continue_on_error:true.

val every : ?start:unit Async_kernel.Deferred.t -> ?stop:unit Async_kernel.Deferred.t -> ?continue_on_error:bool -> Time.Span.t -> (unit -> unit) -> unit

every ?start ?stop span f is every' ?start ?stop span (fun () -> f (); Deferred.unit)

val run_at_intervals' : ?start:Time.t -> ?stop:unit Async_kernel.Deferred.t -> ?continue_on_error:bool -> Time.Span.t -> (unit -> unit Async_kernel.Deferred.t) -> unit

run_at_intervals' ?start ?stop span f runs f() at increments of start + i * span for non-negative integers i, until stop becomes determined. run_at_intervals' waits for the result of f to become determined before waiting for the next interval.

Exceptions raised by f are always sent to monitor in effect when run_at_intervals' was called, even with ~continue_on_error:true.

val run_at_intervals : ?start:Time.t -> ?stop:unit Async_kernel.Deferred.t -> ?continue_on_error:bool -> Time.Span.t -> (unit -> unit) -> unit

run_at_intervals ?start ?stop ?continue_on_error span f is equivalent to:


        run_at_intervals' ?start ?stop ?continue_on_error span
          (fun () -> f (); Deferred.unit)