--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1HeterogeneousHeapYoungGenSizer.hpp	Fri Dec 21 08:18:59 2018 -0800
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2018, 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_G1HETEROGENEOUSHEAPYOUNGGENSIZER_HPP
+#define SHARE_VM_GC_G1_G1HETEROGENEOUSHEAPYOUNGGENSIZER_HPP
+
+#include "gc/g1/g1YoungGenSizer.hpp"
+
+// This class prevents the size of young generation of G1 heap to exceed dram
+// memory available. If set on command line, MaxRAM and MaxRAMFraction/MaxRAMPercentage
+// are used to determine the maximum size that young generation can grow.
+// Else we set the maximum size to 80% of dram available in the system.
+
+class G1HeterogeneousHeapYoungGenSizer : public G1YoungGenSizer {
+private:
+  // maximum no of regions that young generation can grow to. Calculated in constructor.
+  uint _max_young_length;
+  void adjust_lengths_based_on_dram_memory();
+
+public:
+  G1HeterogeneousHeapYoungGenSizer();
+
+  // Calculate the maximum length of the young gen given the number of regions
+  // depending on the sizing algorithm.
+  virtual void adjust_max_new_size(uint number_of_heap_regions);
+
+  virtual void heap_size_changed(uint new_number_of_heap_regions);
+};
+
+#endif // SHARE_VM_GC_G1_G1HETEROGENEOUSHEAPYOUNGGENSIZER_HPP