+ added a second version of wait-event. See event.scm for details.

scheme/xlib/event.scm

@@ -146,13 +146,25 @@
 
 ;; wait-event blocks the current thread until an event is available,
 ;; and then it returns this new event.
-;; In future releases this should be done with a select. But for now
-;; we just do a loop with event-ready? and next-event. On this machine
-;; that uses an acceptable amount of about 1% CPU-Time.
 
-(define (wait-event display)
-  (if (event-ready? display)
-      (next-event display)
+;; This does not work yet! We are working on it.
+;(define (wait-event dpy) ; needs ports, locks
+;  (let ((port (display-message-inport dpy)))
+;    (display "obtaining port lock..." (current-error-port))
+;    (obtain-lock (port-lock port))
+;    (display " ...got it\n" (current-error-port))
+;
+;    (display "waiting for events..." (current-error-port))
+;    (wait-for-channel (port->channel port))
+;    (display " ...receiving events.\n" (current-error-port))
+;
+;    (release-lock (port-lock port))
+;    (next-event dpy)))
+
+;; The old, ugly version that works...
+(define (wait-event dpy)
+  (if (event-ready? dpy)
+      (next-event dpy)
       (begin
 	(sleep 20) ; sleep for 20 ms
-	(wait-event display))))
+	(wait-event dpy))))

scheme/xlib/xlib-packages.scm

@@ -75,6 +75,9 @@
   (open scheme
 	external-calls
 	threads  ;; for sleep
+	ports locks  ;; for locking the port
+	channel-i/o ;; for wait-for-channel
+	scsh-level-0 ;; for port->channel
 	xlib-types)
   (files event))