diff --git a/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.ml b/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.ml
index b255239dd4d..1ca5e916ef4 100644
--- a/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.ml
+++ b/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.ml
@@ -111,3 +111,23 @@ module Delay = struct
         (* If the wait hasn't happened yet then store up the signal *)
     )
 end
+
+let wait_timed_read fd timeout =
+  match Xapi_stdext_unix.Unixext.select [fd] [] [] timeout with
+  | [], _, _ ->
+      false
+  | [fd'], _, _ ->
+      assert (fd' = fd) ;
+      true
+  | _ ->
+      assert false
+
+let wait_timed_write fd timeout =
+  match Xapi_stdext_unix.Unixext.select [] [fd] [] timeout with
+  | _, [], _ ->
+      false
+  | _, [fd'], _ ->
+      assert (fd' = fd) ;
+      true
+  | _ ->
+      assert false
diff --git a/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.mli b/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.mli
index 8349ab71366..057aedfa700 100644
--- a/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.mli
+++ b/ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext.mli
@@ -33,3 +33,7 @@ module Delay : sig
   val signal : t -> unit
   (** Sends a signal to a waiting thread. See 'wait' *)
 end
+
+val wait_timed_read : Unix.file_descr -> float -> bool
+
+val wait_timed_write : Unix.file_descr -> float -> bool