do what you can when not in 3m

svn: r5878

collects/mzlib/sandbox.ss

@@ -173,12 +173,14 @@
 
   (define-struct (exn:fail:resource exn:fail) (resource))
 
+  (define 3m? (eq? '3m (system-type 'gc)))
+
   (define (call-with-limits sec mb thunk)
     (let ([cust (make-custodian)]
           [ch   (make-channel)]
           ;; use this to copy parameter changes from the sub-thread
           [p    current-preserved-thread-cell-values])
-      (when mb (custodian-limit-memory cust (* mb 1024 1024) cust))
+      (when (and mb 3m?) (custodian-limit-memory cust (* mb 1024 1024) cust))
       (let* ([work (parameterize ([current-custodian cust])
                      (thread (lambda ()
                                (channel-put ch

collects/tests/mzscheme/sandbox.ss

@@ -56,7 +56,10 @@
    (id 1) => 1
    (id (plus1 x)) => 1
    (loop) =err> "out of time"
-   (memory 1000000) =err> "out of memory"
+   --top--
+   (when (eq? '3m (system-type 'gc))
+     (t --eval-- (memory 1000000) =err> "out of memory"))
+   --eval--
    (printf "x = ~s\n" x) => (void)
    ,eof =err> "terminated"
    x =err> "terminated"
@@ -266,6 +269,4 @@
    (set! y 789) ; would be an error without the `set!' parameter
    y => 789
 
-   )
-
-  )
+   ))