--- /dev/null	2020-01-14 10:13:11.907818291 +0100
+++ new/src/hotspot/share/gc/shenandoah/shenandoahObjectMarker.cpp	2020-02-21 11:14:41.032210252 +0100
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2020, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+
+#include "precompiled.hpp"
+
+#include "gc/shared/markBitMap.inline.hpp"
+#include "gc/shenandoah/shenandoahHeap.hpp"
+#include "gc/shenandoah/shenandoahObjectMarker.hpp"
+
+bool ShenandoahObjectMarker::init() {
+  assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints");
+  // Bailout if failed to commit aux bitmap
+  if (!_heap->commit_aux_bitmap()) {
+    _bit_map = NULL;
+    return false;
+  }
+  _bit_map->clear();
+  return true;
+}
+
+void ShenandoahObjectMarker::done() {
+  if (_bit_map != NULL) {
+    _heap->uncommit_aux_bit_map();
+  }
+  delete this;
+}
+
+bool ShenandoahObjectMarker::mark(oop o) {
+  assert(_bit_map != NULL, "Should have been bailed out");
+  if (_bit_map->is_marked(o)) return false;
+  _bit_map->mark(o);
+  return true;
+}
+
+bool ShenandoahObjectMarker::marked(oop o) {
+  assert(_bit_map != NULL, "Should have been bailed out");
+  return _bit_map->is_marked(o);
+}