--- old/src/hotspot/share/gc/g1/dirtyCardQueue.cpp	Wed Nov  8 08:12:25 2017
+++ new/src/hotspot/share/gc/g1/dirtyCardQueue.cpp	Wed Nov  8 08:12:25 2017
@@ -320,12 +320,8 @@
   clear();
   // Since abandon is done only at safepoints, we can safely manipulate
   // these queues.
-  {
-    ThreadsListHandle tlh;
-    JavaThreadIterator jti(tlh.list());
-    for (JavaThread* t = jti.first(); t != NULL; t = jti.next()) {
-      t->dirty_card_queue().reset();
-    }
+  for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) {
+    t->dirty_card_queue().reset();
   }
   shared_dirty_card_queue()->reset();
 }
@@ -343,12 +339,8 @@
   int save_max_completed_queue = _max_completed_queue;
   _max_completed_queue = max_jint;
   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
-  {
-    ThreadsListHandle tlh;
-    JavaThreadIterator jti(tlh.list());
-    for (JavaThread* t = jti.first(); t != NULL; t = jti.next()) {
-      concatenate_log(t->dirty_card_queue());
-    }
+  for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) {
+    concatenate_log(t->dirty_card_queue());
   }
   concatenate_log(_shared_dirty_card_queue);
   // Restore the completed buffer queue limit.