Add a simple float test and prevent inlining

This prevents Flamda from noticing that we are potentially storing float values into a non-float array.
ocaml-multicore · Apr 2, 2024 · b6e62a1 · b6e62a1
1 parent beaec4f
commit b6e62a1
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/src_lockfree/spsc_queue.ml b/src_lockfree/spsc_queue.ml
@@ -50,7 +50,10 @@ let create ~size_exponent =
 
 type _ mono = Unit : unit mono | Bool : bool mono
 
-let push_as (type r) t element (mono : r mono) : r =
+(* NOTE: Uses of [@inline never] prevent Flambda from noticing that we might be
+   storing float values into a non-float array. *)
+
+let[@inline never] push_as (type r) t element (mono : r mono) : r =
   let size = Array.length t.array in
   let tail = Atomic.fenceless_get t.tail in
   let head_cache = !(t.head_cache) in
@@ -75,7 +78,7 @@ exception Empty
 type ('a, _) poly = Option : ('a, 'a option) poly | Value : ('a, 'a) poly
 type op = Peek | Pop
 
-let pop_or_peek_as (type a r) (t : a t) op (poly : (a, r) poly) : r =
+let[@inline never] pop_or_peek_as (type a r) t op (poly : (a, r) poly) : r =
   let head = Atomic.fenceless_get t.head in
   let tail_cache = !(t.tail_cache) in
   if

diff --git a/test/spsc_queue/test_spsc_queue.ml b/test/spsc_queue/test_spsc_queue.ml
@@ -50,7 +50,13 @@ let test_parallel () =
   Domain.join producer;
   Printf.printf "test_spsc_queue_parallel: ok (transferred = %d)\n" !last_num
 
+let test_float () =
+  let q = Spsc_queue.create ~size_exponent:1 in
+  assert (Spsc_queue.try_push q 1.01);
+  assert (Spsc_queue.pop_opt q = Some 1.01)
+
 let _ =
   test_empty ();
   test_full ();
-  test_parallel ()
+  test_parallel ();
+  test_float ()