Here is a more Racket-y version of this:
#lang racket
(define (ping hostname port-no personalip)
(define c (make-custodian))
(define t
(parameterize ((current-custodian c))
(thread
(lambda ()
(with-handlers ((exn:fail:network?
(lambda (x)
(printf "~a:~a ~a\n" hostname port-no " NO"))))
(define-values (in out) (tcp-connect hostname port-no))
(write "'ping" out)
(write personalip out)
(flush-output out)
(printf "~a:~a ~a\n" hostname port-no (read in)))))))
(sync/timeout 0.01 t)
(custodian-shutdown-all c))
On Apr 20, 2014, at 10:41 AM, nicolas carraggi wrote:
> Hey guys,
>
> Thanks a lot for your quick answers!
>
> My ping method now:
>
> (define (ping hostname port-no personalip)
> (define t (thread
> (lambda ()
> (with-handlers ((exn:fail:network? (lambda (x) (begin
> (displayln (string-append hostname ":" (number->string port-no) "
> NOOOOOOOOOO")) #f))));(displayln (exn-message x)))))
> (define-values (in out) (tcp-connect hostname port-no))
> (write "'ping" out)
> (write personalip out)
> (flush-output out)
> (display (string-append hostname ":" (number->string
> port-no) " "))
> (displayln (read in))
> (close-input-port in)
> (close-output-port out)
> #t))))
> (sync/timeout 0.01 t)
> (kill-thread t))
>
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> This is the result when I do a multicast from 192.168.1.0 to 192.168.1.200. (
> a lot of these don't exist and that's why tcp-connect was taking ages to
> throw an error.) Those returning a NOOOOO are existing network nodes where no
> server is running. Pong is the answer from the server running on my laptop.
>
> > (multicast-ping "192.168.1.100" 8080 0 200)
> 192.168.1.0:8080 NOOOOOOOOOO
> 192.168.1.105:8080 NOOOOOOOOOO
> 192.168.1.108:8080 pong
> -------------------
> Multicast finished!
>
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
>
> It's still test-code but it's working fine now, maybe the timout time is too
> small but now it works well!
>
> Greetings,
> Nicolas
>
> Subject: Re: [racket-dev] Implementation question
> From: matth...@ccs.neu.edu
> Date: Sat, 19 Apr 2014 09:25:27 -0400
> CC: nicocarra...@hotmail.com; dev@racket-lang.org
> To: laurent.ors...@gmail.com
>
>
> Let me recommend events instead:
>
> #lang racket
>
> ;; Nat -> Void
> ;; wait for t seconds before connecting to google.com, then stop
> (define (do-work t)
> (thread
> (lambda ()
> (with-handlers ((exn:fail:network? (lambda (x) (displayln (exn-message
> x)))))
> (sleep t)
> (define-values (in out) (tcp-connect "google.com" 80))
> 'done))))
>
> ;; returns #f if 3 seconds pass w/o the thread shutting down
> (sync/timeout 3 (do-work (random 6)))
>
>
>
> On Apr 19, 2014, at 8:34 AM, Laurent wrote:
>
> One simpler possibility is to use `tcp-connect/enable-break` and run a timer
> in parallel to break it after a shorter delay.
> For example:
>
> (define-values (in out) (values #f #f))
>
> (define connect-thread
> (thread
> (λ()(set!-values (in out)
> (tcp-connect "www.google.com" 80)))))
>
> (sleep 3)
> (unless in
> (displayln "Connection not established. Breaking thread.")
> (break-thread connect-thread))
>
> The timer can also be place into its own thread if you need to set up several
> connections in parallel.
>
> Hope this helps,
> Laurent
>
>
> On Thu, Apr 17, 2014 at 6:48 PM, nicolas carraggi <nicocarra...@hotmail.com>
> wrote:
> Hello,
>
> I am actually using "Racket/tcp" for a project in Racket.
> I'm creating a peer-to-peer network but now I encountered a small problem.
> For a multicast I want to connect with each server on the same network.
> For this I use "tcp-connect", but when i try to connect to an ip address
> which is not hosting a server, throwing the error only happens after more
> than 1 minute. So I would like to use a modified "tcp-connect" with a smaller
> time-out.
>
> Where can I find the implementation of "tcp-connect"?
>
> I already found "tcp.rkt" but there it gets the "tcp-connect" method from
> "'#%network" but I can't find this one...
>
> Greetings!
> Nicolas
>
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