diff --git a/client.rkt b/client.rkt new file mode 100644 index 0000000..70df4e6 --- /dev/null +++ b/client.rkt @@ -0,0 +1,77 @@ +#lang racket +(require math/base) ;; for random number generation + +;; 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: ") + +(define fair (make-semaphore 1)) + +;; 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") diff --git a/server.rkt b/server.rkt new file mode 100644 index 0000000..57874a8 --- /dev/null +++ b/server.rkt @@ -0,0 +1,155 @@ +#lang racket +(require math/base) ;; for random number generation + +;; globals +;; must control access via semaphore as listener thread or broadcast thread +;; might need to access it +(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)) + + +;; + +;; 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 +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + + +;; 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")