--- /dev/null	2018-11-30 10:10:44.238550338 +0100
+++ new/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.hpp	2018-11-30 21:09:22.480690202 +0100
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP
+#define SHARE_VM_GC_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP
+
+#include "memory/allocation.hpp"
+#include "gc/shenandoah/shenandoahHeap.hpp"
+#include "gc/shenandoah/shenandoahHeapRegionSet.hpp"
+#include "gc/shenandoah/shenandoahTaskqueue.hpp"
+#include "runtime/thread.hpp"
+
+class ShenandoahTraversalGC : public CHeapObj<mtGC> {
+private:
+  ShenandoahHeap* const _heap;
+  ShenandoahObjToScanQueueSet* const _task_queues;
+  ShenandoahHeapRegionSet _traversal_set;
+
+public:
+  ShenandoahTraversalGC(ShenandoahHeap* heap, size_t num_regions);
+  ~ShenandoahTraversalGC();
+
+  ShenandoahHeapRegionSet* traversal_set() { return &_traversal_set; }
+
+  void reset();
+  void prepare();
+  void init_traversal_collection();
+  void concurrent_traversal_collection();
+  void final_traversal_collection();
+
+  template <class T, bool STRING_DEDUP, bool DEGEN>
+  inline void process_oop(T* p, Thread* thread, ShenandoahObjToScanQueue* queue, ShenandoahMarkingContext* const mark_context);
+
+  bool check_and_handle_cancelled_gc(ShenandoahTaskTerminator* terminator, bool sts_yield);
+
+  ShenandoahObjToScanQueueSet* task_queues();
+
+  void main_loop(uint worker_id, ShenandoahTaskTerminator* terminator, bool sts_yield);
+
+private:
+  void prepare_regions();
+
+  template <class T>
+  void main_loop_work(T* cl, jushort* live_data, uint worker_id, ShenandoahTaskTerminator* terminator, bool sts_yield);
+
+  void preclean_weak_refs();
+  void weak_refs_work();
+  void weak_refs_work_doit();
+
+  void fixup_roots();
+};
+
+#endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHTRAVERSALGC_HPP