- disabled creation of tcp listener in erl.ss, which caused infinite loop

on machines with networking completely turned off
- added find-listener/port, which may be used in the future to enable
  networking explicitly (though erl.ss will need significant mods for that)
- removed mention of distribution in README for demos (i.e., net-pong demo)

- minor bug fix in gui wrapper

- noted that spreadsheet is broken on MacOS

svn: r3403

collects/frtime/demos/README

@@ -21,36 +21,6 @@ pong.ss : A simple pong/air-hockey game.  The left paddle moves with
 numeric keypad; the right paddle moves with the mouse.  The 'r' key
 resets the score.
 
-net-pong-*.ss : A networked version of the pong/air-hockey game.
-Currently known to work under Linux.  To play, open the client on one
-machine and the server on another.  Execute both (and require if
-necessary, depending on language level).  Evaluate (self) on each.
-Results will be something like:
-
-[client]
-> (self)
-#3(tid 128.148.38.2:1180 main)
-
-and
-[server]
-> (self)
-#3(tid 128.148.33.71:1178 main)
-
-Now tell each machine about the other:
-[client]
-> (set-cell! server (make-tid '128.148.33.71 1178 'frtime-heart))
-
-[server]
-> (set-cell! client (make-tid '128.148.38.2 1180 'frtime-heart))
-
-Note the differences between the #3(tid ...) output and the (make-tid ...)
-commands---there is no colon (:) between the host and port, and main becomes
-'frtime-heart.
-
-After setting the cells, complete the connection by clicking the left
-mouse button in both animation windows.  The player running the server
-can reset the score by pressing 'r'.
-
 pizza.ss : A simple "pizza ordering" user interface based on an HtDP
 exercise.
 

collects/frtime/demos/gui/fred.ss

@@ -230,7 +230,8 @@
     (add-signal-controls
      (class gauge%
        (init value)  
-       (super-new))
+       (super-new)
+       (send this set-value value))
      (value set-value 0)
      (range set-range 1)))
   

collects/frtime/demos/spreadsheet/doc.txt

@@ -29,3 +29,4 @@ Known Bugs:
 - Whole-screen redraw, as when scrolling or resizing, is super slow.
 - Errors arising during re-evaluation (not during initial evaluation) go
   to the DrScheme interactions window instead of propagating to the cell.
+- Does not work on MacOS

collects/frtime/erl.ss

@@ -41,11 +41,18 @@
   
   ; for thread ids, port is the TCP port number (not to be confused with MzScheme ports)
   (define-values (listener port)
-    ; find first free port after 1178
-    (let loop ([port 1178])
-      (with-handlers
-          ([exn:fail:network? (lambda (_) (loop (add1 port)))])
-        (values (tcp-listen port) port))))
+    ; for the time being, disable distribution
+    (values never-evt 1178))
+  
+  (define (find-listener/port num-retries)
+    (parameterize ([current-pseudo-random-generator (make-pseudo-random-generator)])
+      (let loop ([i 0])
+        (with-handlers* ([(lambda (exn)
+                            (and (exn:fail:network? exn)
+                                 (< i num-retries)))
+                          (lambda (_) (loop (add1 i)))])
+          (let ([port (+ 1024 (random 64000))])
+            (values (tcp-listen port) port))))))
   
   (define ip-address '127.0.0.1
     #;(let*-values