let kill_worker =
(* the following lines are from Xavier Leroy: http://alan.petitepomme.net/cwn/2005.11.08.html *)
let interrupt = ref None in
let kill_worker =
(* the following lines are from Xavier Leroy: http://alan.petitepomme.net/cwn/2005.11.08.html *)
let interrupt = ref None in