Module Clock

module Clock: sig .. end

Schedule jobs to run at a time in the future.

The underlying implementation uses a heap of events, one for each job that needs to run in the future. The async scheduler is responsible for waking up at the right time to run the jobs.

val run_at : Core.Std.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 : Core.Std.Time.Span.t -> ('a -> unit) -> 'a -> unit

val at : Core.Std.Time.t -> unit 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 : Core.Std.Time.Span.t -> unit Deferred.t

val with_timeout : Core.Std.Time.Span.t ->
       'a Deferred.t -> [ `Result of 'a | `Timeout ] 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 inherent race between d and the timeout, the preference is given to d.

module Event: sig .. end

Events provide abortable versions of at and after.

val at_varying_intervals : ?stop:unit Deferred.t ->
       (unit -> Core.Std.Time.Span.t) -> unit 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:Core.Std.Time.t ->
       ?stop:unit Deferred.t -> Core.Std.Time.Span.t -> unit 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 Deferred.t ->
       ?stop:unit Deferred.t ->
       ?continue_on_error:bool ->
       Core.Std.Time.Span.t -> (unit -> unit 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.

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

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