core-async-blocking-put.clj

(def c (a/chan 10 cat))

(go-loop [i 0]
  (let [batch (range i (+ i 3))]
    (when (>! c batch)
      (println "Put succeeded:" batch)
      (recur (+ i 3)))))

;; Put succeeded: (0 1 2)
;; Put succeeded: (3 4 5)
;; Put succeeded: (6 7 8)
;; Put succeeded: (9 10 11)

;; // Predictable so far. Buffer filled up to 12 items and the next put blocked.

(<!! c) ; => 0
;; Put succeeded: (12 13 14)

(<!! c) ; => 1
;; Put succeeded: (15 16 17)

(<!! c) ; => 2
;; Put succeeded: (18 19 20)

;; // What? The buffer keeps growing after each single take!