--- /dev/null	2019-06-03 18:05:13.248999865 -0400
+++ new/src/hotspot/share/gc/shenandoah/shenandoahConcurrentRoots.cpp	2019-06-15 08:29:50.656032758 -0400
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2019, Red Hat, Inc. All rights reserved.
+ *
+ * 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/shenandoah/shenandoahConcurrentRoots.hpp"
+#include "gc/shenandoah/shenandoahHeap.inline.hpp"
+
+bool ShenandoahConcurrentRoots::can_do_concurrent_roots() {
+  // Don't support traversal GC at this moment
+  return !ShenandoahHeap::heap()->is_concurrent_traversal_in_progress();
+}
+
+bool ShenandoahConcurrentRoots::should_do_concurrent_roots() {
+  ShenandoahHeap* const heap = ShenandoahHeap::heap();
+  bool stw_gc_in_progress = heap->is_full_gc_in_progress() ||
+                            heap->is_degenerated_gc_in_progress();
+  return can_do_concurrent_roots() &&
+         !stw_gc_in_progress;
+}