--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1HeapTransition.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1HEAPTRANSITION_HPP
+#define SHARE_VM_GC_G1_G1HEAPTRANSITION_HPP
+
+#include "gc/shared/plab.hpp"
+
+class G1CollectedHeap;
+
+class G1HeapTransition {
+  struct Data {
+    size_t _eden_length;
+    size_t _survivor_length;
+    size_t _old_length;
+    size_t _humongous_length;
+    size_t _metaspace_used_bytes;
+
+    Data(G1CollectedHeap* g1_heap);
+  };
+
+  G1CollectedHeap* _g1_heap;
+  Data _before;
+
+public:
+  G1HeapTransition(G1CollectedHeap* g1_heap);
+
+  void print();
+};
+
+#endif // SHARE_VM_GC_G1_G1HEAPTRANSITION_HPP