;;;; The agent, end to end: a running program takes a redefinition over a
;;;; socket and installs it between "frames".
;;;;
;;;; [tick] is the function that gets redefined. It is called once before any
;;;; reload and once after each of two of them, and nothing else in this file
;;;; changes, so the three numbers are the whole result. Two reloads and not
;;;; one because that is the daemon's actual loop: a second module built from
;;;; the same session, reading state the first one introduced.
;;;;
;;;; It waits rather than polling on a timer because a test that races the
;;;; frame rate is a test that fails on a loaded machine. A game loop calls
;;;; poll at the top of the frame and ignores the answer; the split is in
;;;; vendor/agent/agent.flan.
(import agent "vendor:agent")

(defvar ticks i64)

(defn tick [] i64
  (set ticks (+ ticks 1))
  ticks)

(defn main [args [string]] i32
  (if (< (len args) 2)
    (do (print-line "usage: agent <socket>") 2)
    (do
      (if (< (agent/start (at args 1)) 0)
        (do (print-line "cannot listen") 1)
        (do
          (print-i64 (tick)) (newline)
          (while (= (agent/wait 100) 0) 0)
          (print-i64 (tick)) (newline)
          (while (= (agent/wait 100) 0) 0)
          (print-i64 (tick)) (newline)
          0)))))