;;;; A program that prints far more than a pipe holds, for the one failure a
;;;; quiet fixture cannot reach.
;;;;
;;;; In a merged `flan dev' the program's stdout is a 64K pipe back into the
;;;; same process, and the only thing reading it is the daemon's accept loop —
;;;; which is not running while the daemon is answering a request. Every other
;;;; fixture here prints a line or two per frame, so the pipe never fills and
;;;; the arrangement looks sound. This one prints 4K per frame, which fills 64K
;;;; in sixteen frames: less time than a module takes to build. By the time an
;;;; evaluation is delivered the game thread is stopped inside fwrite, and it
;;;; stays there until somebody reads — so a daemon that waits for a frame
;;;; boundary without draining waits for one that cannot arrive, and then says
;;;; the program is not calling (agent/poll).
;;;;
;;;; It is calling it. See lib/dev.ml's [eval_expr], which drains every tick.
(import agent "vendor:agent")

;;; Counted so that an evaluation has something of the program's own to read,
;;; and so a transcript can be checked for progress rather than only for text.
(defvar frames i64)

(defn chatter [] i64
  ;; Sixty-four lines of sixty-three characters and a newline: 4096 bytes a
  ;; frame, written through the line buffer flan_rt.c asks for, so each line
  ;; is its own write and the block happens in the middle of a frame rather
  ;; than at a flush somewhere else.
  (dotimes [i 64]
    (println "..............................................................."))
  (set frames (+ frames 1))
  frames)

(defn main [] i32
  (agent/start "/tmp/flan-dev-chatty-fallback.sock")
  ;; 24000 for dev-repl.flan's reason: the test closes the connection when it
  ;; is done and the daemon takes the program with it, so the count only has
  ;; to outlast the checks. A program that reached its last frame mid-test
  ;; would fail honestly and for the wrong reason.
  (dotimes [i 24000]
    (chatter)
    (agent/wait 1))
  0)