Better.

src/cry.ml

@@ -34,18 +34,16 @@ let poll =
             let timeout = Int64.add int frac in
             Poll.Timeout.after timeout
     in
+    Poll.clear poll;
     List.iter (fun fd -> Poll.set poll fd Poll.Event.read) r;
     List.iter (fun fd -> Poll.set poll fd Poll.Event.write) w;
-    Fun.protect
-      (fun () ->
-        ignore (Poll.wait poll timeout);
-        let r = ref [] in
-        let w = ref [] in
-        Poll.iter_ready poll ~f:(fun fd -> function
-          | { Poll.Event.readable = true; _ } -> r := fd :: !r
-          | _ -> w := fd :: !w);
-        (!r, !w))
-      ~finally:(fun () -> Poll.clear poll)
+    ignore (Poll.wait poll timeout);
+    let r = ref [] in
+    let w = ref [] in
+    Poll.iter_ready poll ~f:(fun fd event ->
+        if event.Poll.Event.readable then r := fd :: !r;
+        if event.Poll.Event.writable then w := fd :: !w);
+    (!r, !w)
 
 type error =
   | Create of exn