src/hotspot/share/gc/g1/survRateGroup.cpp

rev 55208 : imported patch 8220089.webrev.0
rev 55209 : imported patch 8220089.webrev.1
rev 55210 : imported patch 8220089.webrev.2

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2019, 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.

@@ -35,11 +35,12 @@
   _accum_surv_rate_pred(NULL),
   _last_pred(0.0),
   _surv_rate_pred(NULL),
   _all_regions_allocated(0),
   _region_num(0),
-  _setup_seq_num(0)
+  _setup_seq_num(0),
+  _retained_region_num(0)
 {
   reset();
   start_adding_regions();
 }
 

@@ -47,10 +48,11 @@
   _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;
+  _retained_region_num   = 0;
 
   // 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) {

@@ -70,11 +72,13 @@
   _region_num = 0;
 }
 
 void SurvRateGroup::start_adding_regions() {
   _setup_seq_num   = _stats_arrays_length;
-  _region_num      = 0;
+  // Retained region number should be reflected to address actual reused case.
+  _region_num      = _retained_region_num;
+  _retained_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);

@@ -88,11 +92,12 @@
   }
 }
 
 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" );
+             "Age in group (" PTR_FORMAT ") should be [0, " SIZE_FORMAT "), but it is %d",
+             p2i(this), _region_num, age_in_group);
 
   double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;
   _surv_rate_pred[age_in_group]->add(surv_rate);
 }