From 7d2d70150787790ab03f8e3af1386b3d8ffc1659 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonygarnockjones@gmail.com>
Date: Thu, 12 Jul 2012 13:25:35 -0400
Subject: [PATCH] os2-tcp-test-bytewise-echo.rkt from 4 July 2012

---
 os2-tcp-test-bytewise-echo.rkt | 51 ++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 os2-tcp-test-bytewise-echo.rkt

diff --git a/os2-tcp-test-bytewise-echo.rkt b/os2-tcp-test-bytewise-echo.rkt
new file mode 100644
index 0000000..4708bcc
--- /dev/null
+++ b/os2-tcp-test-bytewise-echo.rkt
@@ -0,0 +1,51 @@
+#lang racket/base
+;; A more different trivial example program demonstrating os2-tcp.rkt.
+
+(require racket/string)
+(require racket/set)
+(require racket/match)
+(require "os2.rkt")
+(require "os2-timer.rkt")
+(require "os2-tcp.rkt")
+
+(define ((connection-handler local-addr remote-addr) self-pid)
+  (define (reader-role)
+    (role 'echoer (topic-subscriber (tcp-channel remote-addr local-addr (wild)))
+      #:state state
+      [(tcp-channel remote _ (? bytes? bs))
+       (transition state
+	 (send-tcp-credit remote-addr local-addr 16)
+	 (send-message (tcp-channel local-addr remote-addr bs)))]
+      [(tcp-channel remote _ (? eof-object?))
+       (transition state
+	 (kill))]))
+
+  (transition 'no-state
+    (send-tcp-credit remote-addr local-addr 16)
+    (reader-role)))
+
+(define (listener local-addr)
+  (transition 'no-state
+    (role 'inbound-handler (topic-subscriber (tcp-channel (wild) local-addr (wild)) #:monitor? #t)
+      #:state state
+      #:topic t
+      #:on-presence (match t
+		      [(topic 'publisher (tcp-channel remote-addr (== local-addr) _) #f)
+		       (transition state (spawn (connection-handler local-addr remote-addr)))]))))
+
+(define (main port)
+  (define (arm-timer)
+    (role 'waiter (topic-subscriber (timer-expired (wild) (wild)))
+      #:state state
+      #:on-presence (transition state (send-message (set-timer 'label 500 'relative)))
+      [(timer-expired _ _)
+       (transition state (delete-role 'waiter) (arm-timer))]))
+  (ground-vm
+   (transition 'none
+     (spawn tcp-spy)
+     (spawn tcp-driver)
+     (spawn timer-driver)
+     (arm-timer)
+     (spawn (listener (tcp-listener port))))))
+
+(main 5999)