simon/moonpool
1
0
Fork 0
mirror of https://github.com/c-cube/moonpool.git synced 2025-12-05 19:00:33 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

remove Fork_join.map_reduce_commutative

Browse source 
A bit too specialized, and not hard to do with `for_`. Let's see if it shows
to be really useful.
This commit is contained in:
Simon Cruanes 2023-07-10 23:19:02 -04:00
parent 9ce94fd242
commit d995992917
No known key found for this signature in database
GPG key ID: EBFFF6F283F3A2B4
2 changed files with 0 additions and 51 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
src/fork_join.ml
View file

@ -207,24 +207,4 @@ let map_list ?chunk_size f (l : _ list) : _ list =
| None -> assert false
| Some x -> x)
type 'a commutative_monoid = {
neutral: unit -> 'a; (** Neutral element *)
combine: 'a -> 'a -> 'a; (** Combine two items. *)
}
let map_reduce_commutative ?chunk_size ~gen ~map
~(reduce : 'b commutative_monoid) n : 'b =
let res = Lock.create (reduce.neutral ()) in
for_ ?chunk_size n (fun low high ->
let local_acc = ref (reduce.neutral ()) in
for i = low to high do
let x = gen i in
let y = map x in
local_acc := reduce.combine !local_acc y
done;
Lock.update res (fun res -> reduce.combine res !local_acc));
Lock.get res
[@@@endif]

31
src/fork_join.mli
View file

@ -106,35 +106,4 @@ val map_list : ?chunk_size:int -> ('a -> 'b) -> 'a list -> 'b list
@since NEXT_RELEASE
{b NOTE} this is only available on OCaml 5. *)
type 'a commutative_monoid = {
neutral: unit -> 'a; (** Neutral element *)
combine: 'a -> 'a -> 'a; (** Combine two items. *)
}
(** A commutative monoid: order of operations does not matter.
@since NEXT_RELEASE *)
val map_reduce_commutative :
?chunk_size:int ->
gen:(int -> 'a) ->
map:('a -> 'b) ->
reduce:'b commutative_monoid ->
int ->
'b
(** [map_reduce_commutative ~gen ~map ~reduce n] produces items of type ['a]
using [gen 0], [gen 1], …, [gen (n-1)]. Items are then mapped using [map]
in background tasks (each task processes up to [chunk_size] items at a time).
Then, items of type ['b] obtained by mapping are reduced together using the
definition of the commutative monoid [reduce]. The order in which they
are reduced is not specified.
@param chunk_size controls granularity of the mapping process
@param gen generates items to process based on an index
@param map takes an item and processes it, independently of other items
@param reduce is used to aggregate results of mapping.
@since NEXT_RELEASE
{b NOTE} this is only available on OCaml 5.
*)
[@@@endif]