;; -*- Mode: Irken -*-

;; Version of coro0.scm that uses getcc/putcc directly.
;;
;; At first blush, it seems that this will be more efficient, since
;;  it's not creating closures upon each yield.  However, we have to
;;  stop yield from being inlined (otherwise the wrong continuation
;;  will be captured), and this may completely undo the advantage?
;;
;; The truth is that using getcc/putcc requires knowledge of what
;;   the compiler is doing, and that's bad.

(include "lib/basis.scm")

(define run-queue (queue/make))

(define (enqueue k)
  (queue/add run-queue k))

(define (dispatch)
  (match (queue/pop run-queue) with
    (maybe:yes k) -> (putcc k #u)
    (maybe:no) -> #u))

(define (^fork f)
  (enqueue (getcc))
  (f)
  (dispatch))

(define fork ^fork)

(define (^yield)
  (enqueue (getcc))
  (dispatch))

(define yield ^yield)

(define (thread n)
  (for-range
      i 10
      (print-string (format "thread# " (int n) ":" (int i) "\n"))
      (yield)
      ))

(print-string "first fork\n")
(fork (lambda () (thread 0)))
(print-string "second fork\n")
(fork (lambda () (thread 1)))
(thread 2)
(print-string (format "queue length = " (int run-queue.length) "\n"))