package ocaml-base-compiler

  1. Overview
  2. Docs
package ocaml-base-compiler
Legend:
Page
Library
Module
Module type
Parameter
Class
Class type
Source

Source file camlinternalAtomic.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(**************************************************************************)
(*                                                                        *)
(*                                 OCaml                                  *)
(*                                                                        *)
(*             Gabriel Scherer, projet Partout, INRIA Paris-Saclay        *)
(*                                                                        *)
(*   Copyright 2020 Institut National de Recherche en Informatique et     *)
(*     en Automatique.                                                    *)
(*                                                                        *)
(*   All rights reserved.  This file is distributed under the terms of    *)
(*   the GNU Lesser General Public License version 2.1, with the          *)
(*   special exception on linking described in the file LICENSE.          *)
(*                                                                        *)
(**************************************************************************)

(* CamlinternalAtomic is a dependency of Stdlib, so it is compiled with
   -nopervasives. *)
external ( == ) : 'a -> 'a -> bool = "%eq"
external ( + ) : int -> int -> int = "%addint"
external ignore : 'a -> unit = "%ignore"

(* We are not reusing ('a ref) directly to make it easier to reason
   about atomicity if we wish to: even in a sequential implementation,
   signals and other asynchronous callbacks might break atomicity. *)
type 'a t = {mutable v: 'a}

let make v = {v}
let get r = r.v
let set r v = r.v <- v

(* The following functions are set to never be inlined: Flambda is
   allowed to move surrounding code inside the critical section,
   including allocations. *)

let[@inline never] exchange r v =
  (* BEGIN ATOMIC *)
  let cur = r.v in
  r.v <- v;
  (* END ATOMIC *)
  cur

let[@inline never] compare_and_set r seen v =
  (* BEGIN ATOMIC *)
  let cur = r.v in
  if cur == seen then (
    r.v <- v;
    (* END ATOMIC *)
    true
  ) else
    false

let[@inline never] fetch_and_add r n =
  (* BEGIN ATOMIC *)
  let cur = r.v in
  r.v <- (cur + n);
  (* END ATOMIC *)
  cur

let incr r = ignore (fetch_and_add r 1)
let decr r = ignore (fetch_and_add r (-1))
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct