58 lines
1.6 KiB
Racket
58 lines
1.6 KiB
Racket
#lang racket
|
|
;; author: Ibrahim Mkusa
|
|
;; about: print and read concurrently
|
|
|
|
;; 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
|
|
(define fair (make-semaphore 1))
|
|
|
|
;; intelligent read, quits when user types in "quit"
|
|
(define (read-loop-i)
|
|
(display usernamei)
|
|
|
|
(semaphore-wait fair)
|
|
(define input (read-line))
|
|
;; do something over here with input maybe send it out
|
|
(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
|
|
(define (hello-world)
|
|
(semaphore-wait fair)
|
|
(display "Hello, World!\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") |