Module Future

module Future: sig .. end

Computations run in background.

type 'a t = java'util'concurrent'Future java_instance

The type of futures, that are computations run in background.

val cancel : 'a t -> bool -> bool

cancel f i attemps to cancel future f, i indicating whether to interrupt the computation if already started. Returns whether the future was cancelled; see cancel(...).

val get : 'a t -> 'a

Waits for the computation to complete, and returns its result; see get(...).
Raises

Java_exception if the thread is interrupted
Java_exception is the computation raised an uncaught exception
Java_exception if the computation was cancelled

val get_time : 'a t -> java_long -> TimeUnit.t -> 'a

get_time f t u is similar to get f, except that the current thread will at most wait for t (time value whose unit is u); see get(...).
Raises

Java_exception if the thread is interrupted
Java_exception is the computation raised an uncaught exception
Java_exception if the computation was cancelled
Java_exception if time has elapsed without completion

val is_cancelled : 'a t -> bool

Tests whether the task was cancelled before completion; see isCancelled(...).

val is_done : 'a t -> bool

Tests whether the computation is completed; see isDone(...).

Null value

val null : 'a t

The null value.

val is_null : 'a t -> bool

is_null obj returns true iff obj is equal to null.

val is_not_null : 'a t -> bool

is_not_null obj returns false iff obj is equal to null.

Miscellaneous

val wrap : 'a t -> 'a t option

wrap obj wraps the reference obj into an option type:

Some x if obj is not null;
None if obj is null.

val unwrap : 'a t option -> 'a t

unwrap obj unwraps the option obj into a bare reference:

Some x is mapped to x;
None is mapped to null.