-/* We assume we have an ANSI C Compiler. */
-GC_bool GC_help_wanted = FALSE;
-unsigned GC_helper_count = 0;
-unsigned GC_active_count = 0;
+STATIC GC_bool GC_help_wanted = FALSE; /* Protected by mark lock */
+STATIC unsigned GC_helper_count = 0; /* Number of running helpers. */
+ /* Protected by mark lock */
+STATIC unsigned GC_active_count = 0; /* Number of active helpers. */
+ /* Protected by mark lock */
+ /* May increase and decrease */
+ /* within each mark cycle. But */
+ /* once it returns to 0, it */
+ /* stays zero for the cycle. */
+