updates to server.rkt and client.rkt

client.rkt

@@ -13,67 +13,90 @@
 ;(current-custodian guard)
 ;; reads values continously from stdin and redisplays them
 
-;;;;;; NOT IN USE ;;;;;;;
+;; Notes connect to server on localhost
-(define (read-loop)
+;; use client template of tcpvanilla
-  (display (read-line))
+;; use event for read-write
-  (display "\n")
-  (read-loop)
-  )
 
-(define input-prompt "input: ")
+;; modify read-loop-i
-(define output-prompt "output: ")
+; read a value and send it to server via output-port
 
-(define fair (make-semaphore 1))
+; is there something in the input port. If yes? display it
+; in the hello world
 
-;; prompt for username and bind to a variable username
+; make connection to server
+(define (client port-no)
+  (define main-client-cust (make-custodian))
+  (parameterize ([current-custodian main-client-cust])
+    ;; connect to server at port 8080
+    (define-values (in out) (tcp-connect "localhost" port-no)) ;; define values
+    (display in)
+    (displayln out)
+    ;; binds to multiple values akin to unpacking tuples in python
     (display "What's your name?\n")
     (define username (read-line))
-(define usernamei (string-append username ": ")) ;; make username appear nicer in a prompt
 
+  ; (thread (lambda ()
+    ;; make threads 2 lines
+    (define a (thread
+                (lambda ()
+                  (let loop []
+                    (receive-messages in)
+                    (sleep 1)
+                    (loop)))))
+    (define t (thread
+                (lambda ()
+                  (let loop []
+                    (send-messages username out)
+                    (sleep 1)
+                    (loop)))))
+    (thread-wait t) ;; returns prompt back to drracket
+    (close-input-port in)
+    (close-output-port out))
+    (custodian-shutdown-all main-client-cust))
+
+
+;; the send-messages
+(define (send-messages username out)
   ;; intelligent read, quits when user types in "quit"
-(define (read-loop-i)
-  
-  
   ;(semaphore-wait fair)
-  (display usernamei)
+  ; (display usernamei)
   (define input (read-line))
   ;; do something over here with input maybe send it out
   
   ;; Tests input if its a quit then kills all threads
   ;; An if would be better here tbh
-  (cond ((string=? input "quit") (begin (kill-thread a)
+  ;; (cond ((string=? input "quit") (begin (kill-thread a)
-                                        (kill-thread t))))
+                                        ;(kill-thread t))))
-  (display (string-append output-prompt input "\n"))
+  (cond ((string=? input "quit") (exit)))
+  ;; modify to send messages to out port 
+  (displayln (string-append username ": " input) out)
+  (flush-output out)
+
   ;(semaphore-post fair)
-  (read-loop-i)
+  ; (read-loop-i out)
 )
 
 
+
 ;; print hello world continously
 ;; "(hello-world)" can be executed as part of background thread
 ;; that prints in the event there is something in the input port
-(define (hello-world)
+(define (receive-messages in)
-  (sleep (random-integer 0 15)) ;; sleep between 0 and 15 seconds to simulate coms
+  ; (sleep (random-integer 0 15)) ;; sleep between 0 and 15 seconds to simulate coms
                                 ;; with server
   ;(semaphore-wait fair)
   ;; we will retrieve the line printed below from the server
-  ;; at this time we simulate the input from different users
+  (define evt (sync/timeout 30 (read-line-evt in)))
-  (define what-to-print (random-integer 0 2))
+  (cond [(eof-object? evt)
-  (if (= what-to-print 0)
+         (displayln "Server connection closed")
-      (display "Doug: What's up, up?\n")
+         (exit)]
-      (display "Fred: Looking good, good!\n"))
+        [(string? evt)
+         (displayln evt)] ; could time stamp here or to send message
+        [else
+          (displayln (string-append "Nothing received from server for 2 minutes."))]
+        )
   ;(semaphore-post fair)
-  (hello-world))
+) 
 
-(define t (thread (lambda ()
+(define stop (client 4321))
-                    (read-loop-i))))
-(define a (thread (lambda ()
-                    (hello-world))))
 
-(thread-wait t) ;; returns prompt back to drracket
-;; below doesn't execute
-; (sleep 10)
-; (kill-thread t)
-; (define a (thread (display "hello world!\n")))
-; (display "John: hello soso\n")
-; (display "Emmanuel: cumbaya!!!!\n")

server.rkt

@@ -11,26 +11,13 @@
 ;; every 5 seconds run to broadcast top message in list
 ;; and remove it from list
 (define messages-s (make-semaphore 1))  ;; control access to messages
-(define messages '())  ;; stores a list of messages(strings) from currents
+(define messages '("hello, world!"))  ;; stores a list of messages(strings) from currents
 
 (define threads-s (make-semaphore 1))  ;; control access to threads
 ;; lets keep thread descriptor values
 (define threads '())  ;; stores a list of client serving threads as thread descriptor values
 
-;; define a broadcast function
+
-(define broadcast
-  (lambda ()
-    (semaphore-wait messages-s)
-    (semaphore-wait threads-s)
-    (if (not (null? messages))
-        (begin (map (lambda (thread-descriptor)
-            (thread-send thread-descriptor (first messages))))
-               (set! messages (rest messages))
-        )
-      (display "No message to display\n") ; for later create file port for errors and save error messages to that file
-      )
-    (semaphore-post threads-s)
-    (semaphore-post messages-s)))
 
 ;;
 
@@ -52,7 +39,8 @@
     ;; Create a thread whose job is to simply call broadcast iteratively
     (thread (lambda ()
               (let loopb []
-                broadcast
+                (sleep 30)  ;; wait 30 secs before beginning to broadcast
+                (broadcast)
                 (sleep 10) ;; sleep for 10 seconds between broadcasts
                 (loopb)))))
   (lambda ()
@@ -63,22 +51,26 @@
   (define cust (make-custodian))
   (parameterize ([current-custodian cust])
     (define-values (in out) (tcp-accept listener))
+    ; discard request header
+    ; Discard the request header (up to blank line):
+    (regexp-match #rx"(\r\n|^)\r\n" in)
     (semaphore-wait connections-s)
     ;; keep track of open ports
-    (append connections (list (list in out)))
+    (set! connections (append connections (list (list in out))))
-    (semaphore-wait connections-s)
+    (semaphore-post connections-s)
 
     ; start a thread to deal with specific client and add descriptor value to the list of threads
-    (append threads (list (thread (lambda ()
+    (set! threads (append threads (list (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)
+            (sleep 360)
             (custodian-shutdown-all cust)))))
 
 ; (define (handle connections)
@@ -87,14 +79,19 @@
 (define (handle in out) 
   ; define function to deal with incoming messages from client
   (define (something-to-say in)
-    (define evt-t0 (sync/timeout 120  (read-line-evt in 'linefeed)))
+    (define evt-t0 (sync/timeout 30  (read-line-evt in 'linefeed)))
-    (cond [(not evt-t0)
+    (cond [(eof-object? evt-t0)
-           (displayln "Nothing received from " (current-thread) "exiting")]
+           (displayln (string-append "Connection closed " (current-thread) "exiting"))
+           (exit)
+           ]
           [(string? evt-t0)
            (semaphore-wait messages-s)
            ; append the message to list of messages
-           (append messages (list evt-t0))
+           (display (string-append evt-t0 "\n"))
-           (semaphore-post messages-s)]))
+           (set! messages (append messages (list evt-t0)))
+           (semaphore-post messages-s)]
+          [else
+           (displayln (string-append "Nothing received from " (current-thread)))]))
 
 
   ; define function to deal with out
@@ -111,13 +108,33 @@
   (thread (lambda ()
             (let loop []
               (something-to-say in)
+              (sleep 1)
               (loop))))
 
   (thread (lambda ()
             (let loop []
-              (something-to-say out)
+              (something-to-send out)
+              (sleep 1)
               (loop))))
   ; (server-loop in out)
   ; (sleep 5) ;; wait 5 seconds to guarantee client has already send message
   'ok
  )
+
+;; define a broadcast function
+(define broadcast
+  (lambda ()
+    (semaphore-wait messages-s)
+    (semaphore-wait threads-s)
+    (if (not (null? messages))
+        (begin (map (lambda (thread-descriptor)
+            (thread-send thread-descriptor (first messages)))
+                    threads)
+               (set! messages (rest messages))
+        )
+      (display "No message to display\n") ; for later create file port for errors and save error messages to that file
+      )
+    (semaphore-post threads-s)
+    (semaphore-post messages-s)))
+
+(define stop (serve 4321)) ;; start server then close with stop