moonpool/src/s_queue.mli
2023-06-06 23:20:52 -04:00

32 lines
1.1 KiB
OCaml

(** Simple blocking queue *)
type 'a t
val create : unit -> _ t
exception Closed
val push : 'a t -> 'a -> unit
(** [push q x] pushes [x] into [q], and returns [()].
@raise Closed if [close q] was previously called.*)
val pop : 'a t -> 'a
(** [pop q] pops the next element in [q]. It might block until an element comes.
@raise Closed if the queue was closed before a new element was available. *)
val try_pop : force_lock:bool -> 'a t -> 'a option
(** [try_pop q] immediately pops the first element of [q], if any,
or returns [None] without blocking.
@param force_lock if true, use {!Mutex.lock} (which can block under contention);
if false, use {!Mutex.try_lock}, which might return [None] even in
presence of an element if there's contention *)
val try_push : 'a t -> 'a -> bool
(** [try_push q x] tries to push into [q], in which case
it returns [true]; or it fails to push and returns [false]
without blocking.
@raise Closed if the locking succeeded but the queue is closed.
*)
val close : _ t -> unit
(** Close the queue, meaning there won't be any more [push] allowed. *)