moonpool/src/lock.mli
2023-07-16 23:36:34 -04:00

35 lines
1 KiB
OCaml

(** Mutex-protected resource.
@since 0.3 *)
type 'a t
(** A value protected by a mutex *)
val create : 'a -> 'a t
(** Create a new protected value. *)
val with_ : 'a t -> ('a -> 'b) -> 'b
(** [with_ l f] runs [f x] where [x] is the value protected with
the lock [l], in a critical section. If [f x] fails, [with_lock l f]
fails too but the lock is released. *)
val update : 'a t -> ('a -> 'a) -> unit
(** [update l f] replaces the content [x] of [l] with [f x], while protected
by the mutex. *)
val update_map : 'a t -> ('a -> 'a * 'b) -> 'b
(** [update_map l f] computes [x', y = f (get l)], then puts [x'] in [l]
and returns [y], while protected by the mutex. *)
val mutex : _ t -> Mutex.t
(** Underlying mutex. *)
val get : 'a t -> 'a
(** Atomically get the value in the lock. The value that is returned
isn't protected! *)
val set : 'a t -> 'a -> unit
(** Atomically set the value.
{b NOTE} caution: using {!get} and {!set} as if this were a {!ref}
is an anti pattern and will not protect data against some race conditions. *)