From fa56c151c2551ad22577766c67ed52832066bf33 Mon Sep 17 00:00:00 2001
From: Tim Vaughan <plugd@thelambdalab.xyz>
Date: Tue, 27 Apr 2021 12:45:47 +0200
Subject: [PATCH] Receiving messages over UDP works.

---
 sam.scm | 43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/sam.scm b/sam.scm
index c819ca5..8e8a730 100644
--- a/sam.scm
+++ b/sam.scm
@@ -5,6 +5,7 @@
 
 (import (chicken io)
         (chicken string)
+        (chicken port)
         matchable
         srfi-18 ; threads
         srfi-69 ; hash-table
@@ -16,7 +17,7 @@
 ;; Actors
 
 (define this-host "localhost")
-(define this-port 1234)
+(define this-port 8000)
 
 (define (make-address host port id)
   (make-uri #:scheme "actor"
@@ -24,15 +25,13 @@
             #:port port
             #:path (list '/ id)))
 
-(define next-local-address
-  (let ((mutex (make-mutex "actor address mutex")))
-    (lambda ()
-      (let ((res #f))
-        (mutex-lock! mutex)
-        (set! res (make-address this-host this-port (uuid)))
-        (mutex-unlock! mutex)
-        res))))
-
+(define (make-local-address . args)
+  (make-address this-host
+                this-port
+                (if (null? args)
+                    (uuid)
+                    (car args))))
+                
 (define (address-id address) (cadr (uri-path address)))
 
 (define (address-local? address)
@@ -42,7 +41,7 @@
 (define actor-table (make-hash-table))
 
 (define (make-actor beh)
-  (let* ((address (next-local-address))
+  (let* ((address (make-local-address))
          (id (address-id address)))
     (hash-table-set! actor-table id beh)
     address))
@@ -137,6 +136,23 @@
     (loop)))
 
 
+;; Network
+
+(define (start-network-listener)
+  (thread-start!
+   (lambda ()
+     (let ((s (udp-open-socket*)))
+       (udp-bind! s #f this-port)
+       (let loop ()
+         (let-values (((n str) (udp-recv s 1024)))
+           (print "Received " n " bytes over network: " str)
+           (match (with-input-from-string str read)
+             ((uri-str message ...)
+              (apply send-message (cons (uri-reference uri-str) message)))
+             (else
+              (print "Warning: received badly formatted message string '" str "'"))))
+         (loop))))))
+
 ;; System interface
 
 (define system
@@ -163,10 +179,13 @@
 
 (thread-start!
  (lambda ()
-   (thread-sleep! 10)
+   (thread-sleep! 120)
    (send-message system 'shutdown)))
 
+(print (uri->string system))
+
 (start-scheduler)
+(start-network-listener)
 (start-console)
 
 ;; (thread-join! scheduler-thread)
-- 
2.20.1