# Module Atomic

    module Atomic: sig .. end

This module provides a purely sequential implementation of the concurrent atomic references provided by the Multicore OCaml standard library:

https://github.com/ocaml-multicore/ocaml-multicore/blob/parallel_minor_gc/stdlib/atomic.mli

This sequential implementation is provided in the interest of compatibility: when people will start writing code to run on Multicore, it would be nice if their use of Atomic was backward-compatible with older versions of OCaml without having to import additional compatibility layers.

- Since 4.12

    type 'a t

An atomic (mutable) reference to a value of type `'a`.

    val make : 'a -> 'a t

Create an atomic reference.

    val get : 'a t -> 'a

Get the current value of the atomic reference.

    val set : 'a t -> 'a -> unit

Set a new value for the atomic reference.

    val exchange : 'a t -> 'a -> 'a

Set a new value for the atomic reference, and return the current value.

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

`compare_and_set r seen v` sets the new value of `r` to `v` only if its current value is physically equal to `seen` -- the comparison and the set occur atomically. Returns `true` if the comparison succeeded (so the set happened) and `false` otherwise.

    val fetch_and_add : int t -> int -> int

`fetch_and_add r n` atomically increments the value of `r` by `n`, and returns the current value (before the increment).

    val incr : int t -> unit

`incr r` atomically increments the value of `r` by `1`.

    val decr : int t -> unit

`decr r` atomically decrements the value of `r` by `1`.