example.clj

(def queue (java.util.concurrent.LinkedBlockingDeque.))

; long running proces
(defn do-long-running-stuff []
  ...
  (.add queue current-state))
  
  
; quil
; 'draw' waits on queue until it has at least
; one element, removes it from queue and draws
(defn draw []
  (let [state (.take queue)]
    ...))