type barrier = | ASP| BSP| SSP| PSP
val set : 'a -> 'b -> unitval worker_num : unit -> intval start : ?barrier:barrier -> string -> string -> unitval register_schedule : ('a list -> ('a * ('b * 'c) list) list) -> unitval register_pull : (('a * 'b) list -> ('a * 'c) list) -> unitval register_push : ('a -> ('b * 'c) list -> ('b * 'c) list) -> unit