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-rw-r--r--Hermes/TODO.txt5
-rw-r--r--Hermes/server.rkt44
2 files changed, 42 insertions, 7 deletions
diff --git a/Hermes/TODO.txt b/Hermes/TODO.txt
index 02c421c..c1f17fa 100644
--- a/Hermes/TODO.txt
+++ b/Hermes/TODO.txt
@@ -6,5 +6,8 @@
6. keep count of connected clients using object orientation
7. maybe fiddle around with irc library
8. separate main running code from definitions
-9. closure connections, messages, threads. Avoid using set! without an object
+**9. closure connections, messages, threads. Avoid using set! without an object
like make-account
+make own count to deal with closures
+10. authentication for databases
+11. user can ask for no of logged in users. Server has to parse
diff --git a/Hermes/server.rkt b/Hermes/server.rkt
index 96f314b..b0f2dff 100644
--- a/Hermes/server.rkt
+++ b/Hermes/server.rkt
@@ -4,10 +4,35 @@
;; TODO wrap "safer send in a function that takes care of semaphores"
;; globals
-;; must control access via semaphore as listener thread or broadcast thread
-;; might need to access it
+; track number of connections with closure
+(define (make-count no-count)
+ (define (increment)
+ (set! no-count (+ no-count 1))
+ no-count)
+ (define (decrement)
+ (set! no-count (- no-count 1))
+ no-count)
+ (define (current-count)
+ no-count)
+ (define (dispatch m)
+ (cond [(eq? m 'increment) increment]
+ [(eq? m 'decrement) decrement]
+ [(eq? m 'current-count) current-count]))
+ dispatch)
+(define c-count (make-count 0))
+(define c-count-s (make-semaphore 1))
+
(define connections '()) ;; maintains a list of open ports
-;; ((in1, out1), (in2, out2), (in3, out3), (in4, out4) ...)
+
+(define (make-connections connections)
+ (define (null-cons?)
+ (null? connections))
+ (define (add in out)
+ (set! connections (append connections (list (list in out))))
+ connections)
+ (define (cons-list)
+ connections))
+
(define connections-s (make-semaphore 1)) ;; control access to connections
;; every 5 seconds run to broadcast top message in list
@@ -54,7 +79,11 @@
(define cust (make-custodian))
(parameterize ([current-custodian cust])
(define-values (in out) (tcp-accept listener))
- ;; TODO
+ ; increment number of connections
+ (semaphore-wait c-count-s)
+ ((c-count 'increment))
+ (semaphore-post c-count-s)
+
(displayln-safe (string-append
"Successfully connected to a client.\n"
"Sending client a welcome message.")
@@ -88,8 +117,11 @@
(cond [(eof-object? evt-t0)
(displayln-safe "Connection closed. EOF received"
stdout)
- (exit)
- ]
+ (semaphore-wait c-count-s)
+ ((c-count 'decrement))
+ (semaphore-post c-count-s)
+ ;(exit)
+ (kill-thread (current-thread))]
[(string? evt-t0)
(semaphore-wait messages-s)
; append the message to list of messages