[multicore] DLS helper in Utils

Summary: As per title, plus a comment fix in AnalysisGlobalState.mli.

Reviewed By: skcho

Differential Revision:
D66805765

Privacy Context Container: L1208441

fbshipit-source-id: de1b9a3506676e9bf10e6c76fc2583ef2f2f99d7

infer/src/IR/AnalysisGlobalState.mli

@@ -10,10 +10,10 @@ open! IStd
 (** {2 Global state for the backend analyses}
 
     While global state should be kept under control at possible (so try to introduce as little of it
-    as possible!), it is sometimes too convenient to ignore. This module lets us do it safely, at
-    least until infer becomes multicore. In particular, global state is appropriately and safely
-    stashed away and restored when the analysis of a procedure is suspended to go analyze another
-    procedure with ondemand (see the {!Backend.Ondemand} module). *)
+    as possible!), it is sometimes too convenient to ignore. This module lets us do it safely. In
+    particular, global state (really, domain-local state) is appropriately and safely stashed away
+    and restored when the analysis of a procedure is suspended to go analyze another procedure with
+    ondemand (see the {!Backend.Ondemand} module). *)
 
 type t
 

infer/src/base/Utils.ml

@@ -513,3 +513,6 @@ let is_term_dumb () =
       true
   | _ ->
       false
+
+
+let with_dls key ~f = Domain.DLS.get key |> f |> Domain.DLS.set key

infer/src/base/Utils.mli

@@ -152,3 +152,7 @@ val zip_fold : init:'a -> f:('a -> Zip.in_file -> Zip.entry -> 'a) -> zip_filena
 val is_term_dumb : unit -> bool
 (** Check if the terminal is "dumb" or otherwise has very limited functionality. For example, Emacs'
     eshell reports itself as a dumb terminal. *)
+
+val with_dls : 'a Domain.DLS.key -> f:('a -> 'a) -> unit
+[@@warning "-unused-value-declaration"]
+(** get value in domain local storage, pass to [f] and set to result *)