keeping count of input and output ports directly is feasible. Trying
a different way.
This commit is contained in:
parent
1edfa0442c
commit
e0354fd1c2
@ -4,8 +4,101 @@
|
|||||||
;; globals
|
;; globals
|
||||||
;; must control access via semaphore as listener thread or broadcast thread
|
;; must control access via semaphore as listener thread or broadcast thread
|
||||||
;; might need to access it
|
;; might need to access it
|
||||||
(define connections '())
|
(define connections '()) ;; maintains a list of open ports
|
||||||
|
;; ((in1, out1), (in2, out2), (in3, out3), (in4, out4) ...)
|
||||||
|
|
||||||
|
;; lets keep thread descriptor values
|
||||||
|
;
|
||||||
|
|
||||||
|
(define fair (make-semaphore 1)) ;; managing connections above
|
||||||
|
|
||||||
|
(define can-i-broadcast (make-semaphore 1))
|
||||||
|
|
||||||
|
;; alternative one keep running list of input and output ports directly
|
||||||
|
;; broadcasts a message to all connected clients
|
||||||
|
(define broadcast-message
|
||||||
|
(lambda (message connections)
|
||||||
|
(map send_message connections)
|
||||||
|
'ok))
|
||||||
|
|
||||||
|
; port pair -> '(input-port output-port)
|
||||||
|
|
||||||
|
(define (get-input-port port-pair)
|
||||||
|
(car port-pair))
|
||||||
|
|
||||||
|
(define (get-output-port port-pair)
|
||||||
|
(cadr port-pair))
|
||||||
|
|
||||||
|
;; gets pair of input and output port of a client and sends a message
|
||||||
|
(define send-message
|
||||||
|
(lambda (client_ports)
|
||||||
|
(displayln message (get-output-port (client-ports)))
|
||||||
|
(flush-output (get-output-port (client-ports)))
|
||||||
|
'ok))
|
||||||
|
|
||||||
|
|
||||||
|
;;
|
||||||
|
|
||||||
|
;; This is a relay server making two clients communicate
|
||||||
|
;; Both `server' and `accept-and-handle' change
|
||||||
|
;; to use a custodian.
|
||||||
|
;; To start server
|
||||||
|
;; (define stop (serve 8080))
|
||||||
|
;; (stop) to close the server
|
||||||
|
|
||||||
|
(define (serve port-no)
|
||||||
|
(define main-cust (make-custodian))
|
||||||
|
(parameterize ([current-custodian main-cust])
|
||||||
|
(define listener (tcp-listen port-no 5 #t))
|
||||||
|
(define (loop)
|
||||||
|
(accept-and-handle listener)
|
||||||
|
(loop))
|
||||||
|
(thread loop))
|
||||||
|
(lambda ()
|
||||||
|
(displayln "\nGoodbye, shutting down all services\n")
|
||||||
|
(custodian-shutdown-all main-cust)))
|
||||||
|
|
||||||
|
(define (accept-and-handle listener)
|
||||||
|
(define cust (make-custodian))
|
||||||
|
(parameterize ([current-custodian cust])
|
||||||
|
(define-values (in out) (tcp-accept listener))
|
||||||
|
(semaphore-wait fair)
|
||||||
|
;; keep track of open ports
|
||||||
|
(append connections (list (list in out)))
|
||||||
|
(semaphore-wait fiar)
|
||||||
|
|
||||||
|
; thread will communicate to all clients at once in a broadcast
|
||||||
|
; manner
|
||||||
|
(thread (lambda ()
|
||||||
|
(handle in out) ;; this handles connection with that specific client
|
||||||
|
(close-input-port in)
|
||||||
|
(close-output-port out)))
|
||||||
|
)
|
||||||
|
;; Watcher thread:
|
||||||
|
;; kills current thread for waiting too long for connection from
|
||||||
|
;; clients
|
||||||
|
(thread (lambda ()
|
||||||
|
(sleep 120)
|
||||||
|
(custodian-shutdown-all cust))))
|
||||||
|
|
||||||
|
; (define (handle connections)
|
||||||
|
; ())
|
||||||
|
;; each thread needs 2 new threads
|
||||||
|
(define (handle in out)
|
||||||
|
; define function to deal with in
|
||||||
|
(define (something-to-say in)
|
||||||
|
(sync/timeout 4 (read-line-evt in 'linefeed)))
|
||||||
|
; define function to deal with out
|
||||||
|
; thread them each
|
||||||
|
; (server-loop in out)
|
||||||
|
(sleep 5) ;; wait 5 seconds to guarantee client has already send message
|
||||||
|
(define echo (read-line in)) ;; bind message to echo
|
||||||
|
(displayln (string-append echo "\n"))
|
||||||
|
; echo back the message, appending echo
|
||||||
|
; could regex match the input to extract the name
|
||||||
|
(writeln "Admin: Hello there" out) ;; append "echo " to echo and send back
|
||||||
|
(flush-output out)
|
||||||
|
)
|
||||||
;; This is a single server communicating directly to the client
|
;; This is a single server communicating directly to the client
|
||||||
|
|
||||||
;;;;;;;;;;;;;;;;;;;;;;Server Client communication;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
;;;;;;;;;;;;;;;;;;;;;;Server Client communication;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||||
@ -80,7 +173,6 @@
|
|||||||
(display "What's your name?\n")
|
(display "What's your name?\n")
|
||||||
(define username (read-line))
|
(define username (read-line))
|
||||||
(define usernamei (string-append username ": ")) ;; make username appear nicer in a prompt
|
(define usernamei (string-append username ": ")) ;; make username appear nicer in a prompt
|
||||||
(define fair (make-semaphore 1))
|
|
||||||
|
|
||||||
;; intelligent read, quits when user types in "quit"
|
;; intelligent read, quits when user types in "quit"
|
||||||
(define (read-loop-i)
|
(define (read-loop-i)
|
||||||
@ -128,4 +220,4 @@
|
|||||||
; (kill-thread t)
|
; (kill-thread t)
|
||||||
; (define a (thread (display "hello world!\n")))
|
; (define a (thread (display "hello world!\n")))
|
||||||
; (display "John: hello soso\n")
|
; (display "John: hello soso\n")
|
||||||
; (display "Emmanuel: cumbaya!!!!\n")
|
; (display "Emmanuel: cumbaya!!!!\n")
|
||||||
|
Loading…
Reference in New Issue
Block a user