refactor: move optional hmap FLS stuff into core/task_local_storage

src/core/dune

@@ -4,6 +4,11 @@
  (libraries
   moonpool.private
   (re_export thread-local-storage)
+  (select
+   hmap_ls_.ml
+   from
+   (hmap -> hmap_ls_.real.ml)
+   (-> hmap_ls_.dummy.ml))
   moonpool.dpool
   (re_export exn_bt)
   (re_export picos))

src/core/hmap_ls_.real.ml

@@ -1,4 +1,4 @@
-open Moonpool.Private.Types_
+open Types_
 
 open struct
   module FLS = Picos.Fiber.FLS
@@ -36,7 +36,8 @@ let[@inline] set_in_local_hmap (k : 'a Hmap.key) (v : 'a) : unit =
 
 (**/**)
 
-module Private_hmap_fls_ = struct
+(* private functions, to be used by the rest of moonpool *)
+module Private_hmap_ls_ = struct
   (** Copy the hmap from f1.fls to f2.fls *)
   let copy_fls (f1 : Picos.Fiber.t) (f2 : Picos.Fiber.t) : unit =
     match FLS.get_exn f1 k_local_hmap with

src/core/task_local_storage.ml

@@ -39,3 +39,5 @@ let with_value k v (f : _ -> 'b) : 'b =
     PF.FLS.set fiber k v;
     let finally () = PF.FLS.set fiber k old_v in
     Fun.protect f ~finally
+
+include Hmap_ls_

src/core/task_local_storage.mli

@@ -36,3 +36,11 @@ val with_value : 'a t -> 'a -> (unit -> 'b) -> 'b
 (** [with_value k v f] sets [k] to [v] for the duration of the call
     to [f()]. When [f()] returns (or fails), [k] is restored
     to its old value. *)
+
+(** {2 Local [Hmap.t]}
+
+    This requires [hmap] to be installed. *)
+
+include module type of struct
+  include Hmap_ls_
+end

src/fib/dune

@@ -4,12 +4,7 @@
  (synopsis "Fibers and structured concurrency for Moonpool")
  (libraries
   moonpool
-  picos
-  (select
-   hmap_fls.ml
-   from
-   (hmap -> hmap_fls.real.ml)
-   (-> hmap_fls.dummy.ml)))
+  picos)
  (enabled_if
   (>= %{ocaml_version} 5.0))
  (flags :standard -open Moonpool_private -open Moonpool)

src/fib/fiber.ml

@@ -259,7 +259,7 @@ let spawn_ ~parent ~runner (f : unit -> 'a) : 'a t =
 
   (* copy local hmap from parent, if present *)
   Option.iter
-    (fun (p : _ t) -> Hmap_fls.Private_hmap_fls_.copy_fls p.pfiber pfiber)
+    (fun (p : _ t) -> Fls.Private_hmap_ls_.copy_fls p.pfiber pfiber)
     parent;
 
   (match parent with

src/fib/fls.ml

@@ -1,2 +1 @@
 include Task_local_storage
-include Hmap_fls

src/fib/fls.mli

@@ -17,11 +17,3 @@
 include module type of struct
   include Task_local_storage
 end
-
-(** {2 Local [Hmap.t]}
-
-    This requires [hmap] to be installed. *)
-
-include module type of struct
-  include Hmap_fls
-end