The handler for the VM schedules now a event that will cause the

deliver thread to call the clients of low-interrupt. So the handler is
short and save.

scsh/low-interrupt.scm

@@ -59,16 +59,40 @@
 
   
 
-(define (init-low-interrupt)
-  (set-interrupt-handler! 
-   (enum interrupt os-signal)
-   (lambda (type arg enabled-interrupts)
-     (call-handlers type enabled-interrupts)))
 
-  (set-interrupt-handler! 
-   (enum interrupt keyboard)
-   (lambda (enabled-interrupts)
-     (call-handlers (enum low-interrupt keyboard) enabled-interrupts)))
+(define (init-low-interrupt)
+  (spawn 
+   (lambda ()
+     (let ((I (current-thread)))
+       (set-interrupt-handler! 
+	(enum interrupt os-signal)
+	(lambda (type arg enabled-interrupts)
+	  (schedule-event I
+			  (enum event-type interrupt)
+			  (enum interrupt os-signal)
+			  type
+			  enabled-interrupts)))
+       (set-interrupt-handler! 
+	(enum interrupt keyboard)
+	(lambda (enabled-interrupts)
+	  (schedule-event I
+			  (enum event-type interrupt)
+			  (enum interrupt keyboard)
+			  enabled-interrupts)))
+       (let loop ()
+	 (wait)
+	 (call-with-values 
+	  get-next-event!
+	  (lambda (event . data)
+	    (if (eq? event (enum event-type interrupt))
+		(let ((i-nr (car data)))
+		  (if (eq? i-nr (enum interrupt os-signal))
+		      (call-handlers (cadr data) (caddr data))
+		      (if (eq? i-nr (enum interrupt keyboard))
+			  (call-handlers (enum low-interrupt keyboard) 
+					 (cadr data))))))))
+	 (loop))))
+   'low-interrupt-deliver-thread)
   
   (call-after-gc!
    (lambda ()
@@ -83,11 +107,9 @@
 (define interrupt-deliver-lock (make-lock))
 
 (define (call-handlers low-interrupt enabled-interrupts)
-  (obtain-lock interrupt-deliver-lock)
   (for-each (lambda (handler-lock-pair)
 	      ((car handler-lock-pair) enabled-interrupts))
-	    (low-interrupt-handler-ref low-interrupt))
-  (release-lock interrupt-deliver-lock))
+	    (low-interrupt-handler-ref low-interrupt)))
 
 
 ;;; the vm uses the timer for the scheduler