diff options
Diffstat (limited to 'server.rkt')
| -rw-r--r-- | server.rkt | 150 |
1 files changed, 54 insertions, 96 deletions
@@ -6,11 +6,24 @@ ;; might need to access it (define connections '()) ;; maintains a list of open ports ;; ((in1, out1), (in2, out2), (in3, out3), (in4, out4) ...) +(define connections-s (make-semaphore 1)) ;; control access to connections +;; 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 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 fair (make-semaphore 1)) ;; managing connections above +;; define a broadcast function +(define broadcast + (lambda () + (semaphore-wait messages-s) + (semaphore-wait threads-s) + (map (lambda (thread-descriptor) + ())))) (define can-i-broadcast (make-semaphore 1)) @@ -40,116 +53,61 @@ (define cust (make-custodian)) (parameterize ([current-custodian cust]) (define-values (in out) (tcp-accept listener)) - (semaphore-wait fair) + (semaphore-wait connections-s) ;; keep track of open ports (append connections (list (list in out))) - (semaphore-wait fiar) + (semaphore-wait connections-s) - ; thread will communicate to all clients at once in a broadcast - ; manner - (thread (lambda () + ; start a thread to deal with specific client and add descriptor value to the list of threads + (append threads (list (thread (lambda () (handle in out) ;; this handles connection with that specific client (close-input-port in) - (close-output-port out))) - ) + (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)))) + (custodian-shutdown-all cust))))) ; (define (handle connections) ; ()) ;; each thread needs 2 new threads (define (handle in out) - ; define function to deal with in + ; define function to deal with incoming messages from client (define (something-to-say in) - (sync/timeout 4 (read-line-evt in 'linefeed))) + (define evt-t0 (sync/timeout 120 (read-line-evt in 'linefeed))) + (cond [(not evt-t0) + (displayln "Nothing received from " (current-thread) "exiting")] + [(string? evt-t0) + (semaphore-wait messages-s) + ; append the message to list of messages + (append messages (list evt-t0)) + (semaphore-post messages-s)])) + + ; define function to deal with out + (define (something-to-send out) + (define evt-t1 (sync/timeout 120 (thread-receive-evt))) + ;; send message to client + (fprintf out "~a~n" (thread-receive)) + (flush-output out) + ) ; thread them each + + ;; i could bind to values, and call wait on them + ;; thread that deals with incoming messages for that particular thread + (thread (lambda () + (let loop [] + (something-to-say in) + (loop)))) + + (thread (lambda () + (let loop [] + (something-to-say out) + (loop)))) ; (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 -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - - -;; author: Ibrahim Mkusa -;; about: print and read concurrently -;; notes: output may need to be aligned and formatted nicely -;; look into -;; https://docs.racket-lang.org/gui/text-field_.html#%28meth._%28%28%28lib._mred%2Fmain..rkt%29._text-field~25%29._get-editor%29%29 - -;; create custodian for managing all resources -;; so we can shutdown everything at once -;(define guard (make-custodian (current-custodian))) -;(current-custodian guard) -;; reads values continously from stdin and redisplays them -(define (read-loop) - (display (read-line)) - (display "\n") - (read-loop) - ) - -(define input-prompt "input: ") -(define output-prompt "output: ") - -;; prompt for username and bind to a variable username -(display "What's your name?\n") -(define username (read-line)) -(define usernamei (string-append username ": ")) ;; make username appear nicer in a prompt - -;; intelligent read, quits when user types in "quit" -(define (read-loop-i) - - - ;(semaphore-wait fair) - (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) - (kill-thread t)))) - (display (string-append output-prompt input "\n")) - ;(semaphore-post fair) - (read-loop-i) - ) - - -;; 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) - (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 what-to-print (random-integer 0 2)) - (if (= what-to-print 0) - (display "Doug: What's up, up?\n") - (display "Fred: Looking good, good!\n")) - ;(semaphore-post fair) - (hello-world)) - -(define t (thread (lambda () - (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") + ; (sleep 5) ;; wait 5 seconds to guarantee client has already send message + 'ok + ) |