repl-server from fibers task

repl-server from fibers task

[Matt Wette]

Hi All,

I'm trying to get fibers to run in "pure asynchronous" style with a 
repl-server.
By "pure asynchronous" style I mean #:hz 0 and possibly 
#:suspendable-ports #f.
My only guess is that maybe the repl-server has a continuation barrier 
in the way.

Either the other task runs, and I get no connection to the repl-server, 
or vice versa.

Anyone here gotten this to work?  If the code worked below the main terminal
would be counting along while one could telnet in from another source 
and use the repl.

Any help appreciated.

Matt

#!/usr/bin/env guile
# -*- scheme -*-
!#

;; connect to monitor via
;;   $ telnet localhost 37146

(use-modules (fibers))
(use-modules (fibers scheduler))
(use-modules (system repl server))

(define (sf fmt . args) (apply simple-format #t fmt args))

(define (task1)
   (let loop ((cnt 0))
     (sleep 1)
     (sf "task1: ~S\n" cnt)
     (loop (1+ cnt))))

(define monitor
   (let ((sock (make-tcp-server-socket)))
     (fcntl sock F_SETFL (logior O_NONBLOCK (fcntl sock F_GETFL)))
     (add-hook! before-read-hook (lambda () (yield-current-task)))
     (lambda () (run-server sock))))

(run-fibers
  (lambda ()
    (spawn-fiber task1)
    (spawn-fiber monitor)
    (sleep 30))
  #:scheduler (make-scheduler #:parallelism 2)
  #:hz 0
  #:install-suspendable-ports? #f)

;;; --- last line ---

Re: repl-server from fibers task

[Matt Wette]

On 12/19/22 1:30 PM, Matt Wette wrote:
> Hi All,
>
> I'm trying to get fibers to run in "pure asynchronous" style with a 
> repl-server.
> By "pure asynchronous" style I mean #:hz 0 and possibly 
> #:suspendable-ports #f.
> My only guess is that maybe the repl-server has a continuation barrier 
> in the way.
>
> Either the other task runs, and I get no connection to the 
> repl-server, or vice versa.
>
> Anyone here gotten this to work?  If the code worked below the main 
> terminal
> would be counting along while one could telnet in from another source 
> and use the repl.
>
> Any help appreciated.
>
> Matt
I got something to work:

#!/usr/bin/env guile
# -*- scheme -*-
!#

;; connect to monitor via
;;   $ telnet localhost 37146

(use-modules ((fibers) #:renamer (lambda (s) (if (eq? s 'sleep) 'fsleep 
s))))
(use-modules (fibers scheduler))
(use-modules (system repl server))
(use-modules (system repl coop-server))

(define (sf fmt . args) (apply simple-format #t fmt args))

(define (task1)
   (let loop ((cnt 0))
     (fsleep 1)
     (sf "task1: ~S\n" cnt)
     (loop (1+ cnt))))

(define (monitor)
   (let* ((server (spawn-coop-repl-server)))
     (let loop ()
       (poll-coop-repl-server server)
       (yield-current-task)
       (loop))))

(run-fibers
  (lambda ()
    (spawn-fiber task1)
    (spawn-fiber monitor)
    (fsleep 30))
  #:hz 0 #:install-suspendable-ports? #f)

;;; --- last line ---