trying to stop cleanly

racket-webview-qt.rkt

@@ -577,14 +577,20 @@
                     )  ; close without closing windows
   )
 
+(define evt-guard-stop -93273)
+
 (define (start-event-processing)
    (thread (λ ()
      (letrec
          ((f
            (λ ()
              (let ((waiting (sync events-channel)))
+               (if (= waiting evt-guard-stop)
+                   (begin
+                     (displayln "got evt-guard-stop, exiting event processing")
+                     evt-guard-stop)
+                   (begin
                      (set! waiting (rkt_webview_events_waiting))
-               ;(displayln (format "Events waiting: ~a" waiting))
                      (while (> waiting 0)
                             (let* ((rkt-evt (rkt_webview_get_event)))
                               (if (eq? rkt-evt #f)
@@ -605,10 +611,13 @@
                                             (cb evt)))))))
                             (set! waiting (- waiting 1))
                             )
-               )
                      (f))
+                   )
+               )
+             )
            ))
-       (f)))))
+       (f))))
+  )
 
 (define evt-processing-thread (start-event-processing))
 
@@ -813,6 +822,7 @@
 
 
 (define (rkt-webview-finalizer rkt-wv-store close-windows message)
+  (displayln "rkt-webview-finalizer active")
   (when close-windows
     (let ((open-windows (hash->list rkt-wv-store)))
       (for-each (λ (kv)
@@ -820,6 +830,7 @@
                         (handle (cdr kv)))
                     (rkt-webview-close handle)))
                 open-windows)))
+  (event-callback evt-guard-stop)
   (rkt_webview_cleanup)
   (unless (eq? message #f) (error message))
   (stop-event-processing)