Durable but cynical publisher in F#

(*
Publisher for durable subscriber
*)
#r @"bin/fszmq.dll"
open fszmq
open fszmq.Context
open fszmq.Socket

#load "zhelpers.fs"

let main () =
use context = new Context(1)

// subscriber tells us when it's ready here
use sync = pull context
"tcp://*:5564" |> bind sync

// we send updates via this socket
use publisher = pub context

// prevent publisher overflow from slow subscribers
(ZMQ.HWM,1UL) |> set publisher

// specify swap space in bytes, this covers all subscribers
(ZMQ.SWAP,25000000UL) |> set publisher
"tcp://*:5565" |> bind publisher

// wait for a synchronization request
sync |> s_recv |> ignore

// now broadcast exactly 10 updates with pause
for update_nbr in 0 .. 9 do
let message = sprintf "Update %d" update_nbr
message |> s_send publisher
sleep 1000
"END" |> s_send publisher

EXIT_SUCCESS

main ()