--- /dev/null	2015-11-03 09:29:33.822158357 +0100
+++ new/src/share/vm/gc/g1/g1IHOPControl.hpp	2015-11-06 11:34:08.420393384 +0100
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2015, 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_G1IHOPCONTROL_HPP
+#define SHARE_VM_GC_G1_G1IHOPCONTROL_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/numberSeq.hpp"
+
+class G1Predictions;
+
+// Manages the decision about the threshold when concurrent marking should start.
+class G1IHOPControl : public CHeapObj<mtGC> {
+ protected:
+  double _ihop_percent;
+  size_t _target_occupancy;
+
+  // Initialize an instance with the initial IHOP value in percent and the target
+  // occupancy. The target occupancy is the number of bytes when marking should
+  // be finished and reclaim started.
+  G1IHOPControl(double initial_ihop_percent, size_t target_occupancy);
+ public:
+  virtual ~G1IHOPControl() { }
+
+  // Get the current marking threshold in bytes.
+  virtual size_t get_conc_mark_start_threshold() = 0;
+
+  // Update information about recent time during which allocations happened,
+  // how many allocations happened and an additional safety buffer.
+  virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) = 0;
+  // Update the time from the end of initial mark to the first mixed gc.
+  virtual void update_time_to_mixed(double marking_length_s) = 0;
+
+  virtual void print() = 0;
+};
+
+class G1StaticIHOPControl : public G1IHOPControl {
+  double _last_allocation_time_s;
+  size_t _last_allocated_bytes;
+  double _last_marking_length_s;
+ public:
+  G1StaticIHOPControl(double ihop_percent, size_t target_occupancy);
+
+  size_t get_conc_mark_start_threshold() { return (size_t) (_ihop_percent * _target_occupancy / 100.0); }
+
+  virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
+    assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
+    _last_allocation_time_s = allocation_time_s;
+    _last_allocated_bytes = allocated_bytes;
+  }
+
+  virtual void update_time_to_mixed(double marking_length_s) {
+   assert(marking_length_s > 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
+    _last_marking_length_s = marking_length_s;
+  }
+
+  virtual void print();
+#ifndef PRODUCT
+  static void test();
+#endif
+};
+
+#endif // SHARE_VM_GC_G1_G1IHOPCONTROL_HPP