(*
 * Copyright (c) 2013-2022 Thomas Gazagnaire <thomas@gazagnaire.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *)

(** {1 Process locking helpers} *)

module type S = sig
  type t
  (** The type for lock manager. *)

  type key
  (** The type for key to be locked. *)

  val v : unit -> t
  (** Create a lock manager. *)

  val with_lock : t -> key -> (unit -> 'a Lwt.t) -> 'a Lwt.t
  (** [with_lock t k f] executes [f ()] while holding the exclusive lock
      associated to the key [k]. *)

  val stats : t -> int
end

(** Create a lock manager implementation. *)
module Make (K : Type.S) : S with type key = K.t
