--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/survRateGroup.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2001, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1Predictions.hpp"
+#include "gc/g1/heapRegion.hpp"
+#include "gc/g1/survRateGroup.hpp"
+#include "logging/log.hpp"
+#include "memory/allocation.hpp"
+
+SurvRateGroup::SurvRateGroup() :
+    _accum_surv_rate_pred(NULL),
+    _surv_rate_pred(NULL),
+    _stats_arrays_length(0) {
+  reset();
+  start_adding_regions();
+}
+
+void SurvRateGroup::reset() {
+  _all_regions_allocated = 0;
+  _setup_seq_num         = 0;
+  _last_pred             = 0.0;
+  // the following will set up the arrays with length 1
+  _region_num            = 1;
+
+  // The call to stop_adding_regions() will use "new" to refill
+  // the _surv_rate_pred array, so we need to make sure to call
+  // "delete".
+  for (size_t i = 0; i < _stats_arrays_length; ++i) {
+    delete _surv_rate_pred[i];
+  }
+  _stats_arrays_length = 0;
+
+  stop_adding_regions();
+
+  // Seed initial _surv_rate_pred and _accum_surv_rate_pred values
+  guarantee( _stats_arrays_length == 1, "invariant" );
+  guarantee( _surv_rate_pred[0] != NULL, "invariant" );
+  const double initial_surv_rate = 0.4;
+  _surv_rate_pred[0]->add(initial_surv_rate);
+  _last_pred = _accum_surv_rate_pred[0] = initial_surv_rate;
+
+  _region_num = 0;
+}
+
+void SurvRateGroup::start_adding_regions() {
+  _setup_seq_num   = _stats_arrays_length;
+  _region_num      = 0;
+}
+
+void SurvRateGroup::stop_adding_regions() {
+  if (_region_num > _stats_arrays_length) {
+    _accum_surv_rate_pred = REALLOC_C_HEAP_ARRAY(double, _accum_surv_rate_pred, _region_num, mtGC);
+    _surv_rate_pred = REALLOC_C_HEAP_ARRAY(TruncatedSeq*, _surv_rate_pred, _region_num, mtGC);
+
+    for (size_t i = _stats_arrays_length; i < _region_num; ++i) {
+      _surv_rate_pred[i] = new TruncatedSeq(10);
+    }
+
+    _stats_arrays_length = _region_num;
+  }
+}
+
+void SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
+  guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
+             "pre-condition" );
+
+  double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;
+  _surv_rate_pred[age_in_group]->add(surv_rate);
+}
+
+void SurvRateGroup::all_surviving_words_recorded(const G1Predictions& predictor, bool update_predictors) {
+  if (update_predictors) {
+    fill_in_last_surv_rates();
+  }
+  finalize_predictions(predictor);
+}
+
+void SurvRateGroup::fill_in_last_surv_rates() {
+  if (_region_num > 0) { // conservative
+    double surv_rate = _surv_rate_pred[_region_num-1]->last();
+    for (size_t i = _region_num; i < _stats_arrays_length; ++i) {
+      _surv_rate_pred[i]->add(surv_rate);
+    }
+  }
+}
+
+void SurvRateGroup::finalize_predictions(const G1Predictions& predictor) {
+  double accum = 0.0;
+  double pred = 0.0;
+  for (size_t i = 0; i < _stats_arrays_length; ++i) {
+    pred = predictor.get_new_prediction(_surv_rate_pred[i]);
+    if (pred > 1.0) pred = 1.0;
+    accum += pred;
+    _accum_surv_rate_pred[i] = accum;
+  }
+  _last_pred = pred;
+}