src/share/vm/gc_implementation/g1/survRateGroup.cpp

Tue, 18 Mar 2014 19:07:22 +0100

author
pliden
date
Tue, 18 Mar 2014 19:07:22 +0100
changeset 6413
595c0f60d50d
parent 3900
d2a62e0f25eb
child 6680
78bbf4d43a14
permissions
-rw-r--r--

8029075: String deduplication in G1
Summary: Implementation of JEP 192, http://openjdk.java.net/jeps/192
Reviewed-by: brutisso, tschatzl, coleenp

     1 /*
     2  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    27 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
    28 #include "gc_implementation/g1/heapRegion.hpp"
    29 #include "gc_implementation/g1/survRateGroup.hpp"
    30 #include "memory/allocation.hpp"
    32 SurvRateGroup::SurvRateGroup(G1CollectorPolicy* g1p,
    33                              const char* name,
    34                              size_t summary_surv_rates_len) :
    35     _g1p(g1p), _name(name),
    36     _summary_surv_rates_len(summary_surv_rates_len),
    37     _summary_surv_rates_max_len(0),
    38     _summary_surv_rates(NULL),
    39     _surv_rate(NULL),
    40     _accum_surv_rate_pred(NULL),
    41     _surv_rate_pred(NULL),
    42     _stats_arrays_length(0) {
    43   reset();
    44   if (summary_surv_rates_len > 0) {
    45     size_t length = summary_surv_rates_len;
    46       _summary_surv_rates = NEW_C_HEAP_ARRAY(NumberSeq*, length, mtGC);
    47     for (size_t i = 0; i < length; ++i) {
    48       _summary_surv_rates[i] = new NumberSeq();
    49     }
    50   }
    52   start_adding_regions();
    53 }
    55 void SurvRateGroup::reset() {
    56   _all_regions_allocated = 0;
    57   _setup_seq_num         = 0;
    58   _accum_surv_rate       = 0.0;
    59   _last_pred             = 0.0;
    60   // the following will set up the arrays with length 1
    61   _region_num            = 1;
    63   // The call to stop_adding_regions() will use "new" to refill
    64   // the _surv_rate_pred array, so we need to make sure to call
    65   // "delete".
    66   for (size_t i = 0; i < _stats_arrays_length; ++i) {
    67     delete _surv_rate_pred[i];
    68   }
    69   _stats_arrays_length = 0;
    71   stop_adding_regions();
    72   guarantee( _stats_arrays_length == 1, "invariant" );
    73   guarantee( _surv_rate_pred[0] != NULL, "invariant" );
    74   _surv_rate_pred[0]->add(0.4);
    75   all_surviving_words_recorded(false);
    76   _region_num = 0;
    77 }
    79 void
    80 SurvRateGroup::start_adding_regions() {
    81   _setup_seq_num   = _stats_arrays_length;
    82   _region_num      = 0;
    83   _accum_surv_rate = 0.0;
    84 }
    86 void
    87 SurvRateGroup::stop_adding_regions() {
    88   if (_region_num > _stats_arrays_length) {
    89     double* old_surv_rate = _surv_rate;
    90     double* old_accum_surv_rate_pred = _accum_surv_rate_pred;
    91     TruncatedSeq** old_surv_rate_pred = _surv_rate_pred;
    93     _surv_rate = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);
    94     _accum_surv_rate_pred = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);
    95     _surv_rate_pred = NEW_C_HEAP_ARRAY(TruncatedSeq*, _region_num, mtGC);
    97     for (size_t i = 0; i < _stats_arrays_length; ++i) {
    98       _surv_rate_pred[i] = old_surv_rate_pred[i];
    99     }
   100     for (size_t i = _stats_arrays_length; i < _region_num; ++i) {
   101       _surv_rate_pred[i] = new TruncatedSeq(10);
   102     }
   104     _stats_arrays_length = _region_num;
   106     if (old_surv_rate != NULL) {
   107       FREE_C_HEAP_ARRAY(double, old_surv_rate, mtGC);
   108     }
   109     if (old_accum_surv_rate_pred != NULL) {
   110       FREE_C_HEAP_ARRAY(double, old_accum_surv_rate_pred, mtGC);
   111     }
   112     if (old_surv_rate_pred != NULL) {
   113       FREE_C_HEAP_ARRAY(TruncatedSeq*, old_surv_rate_pred, mtGC);
   114     }
   115   }
   117   for (size_t i = 0; i < _stats_arrays_length; ++i) {
   118     _surv_rate[i] = 0.0;
   119   }
   120 }
   122 double
   123 SurvRateGroup::accum_surv_rate(size_t adjustment) {
   124   // we might relax this one in the future...
   125   guarantee( adjustment == 0 || adjustment == 1, "pre-condition" );
   127   double ret = _accum_surv_rate;
   128   if (adjustment > 0) {
   129     TruncatedSeq* seq = get_seq(_region_num+1);
   130     double surv_rate = _g1p->get_new_prediction(seq);
   131     ret += surv_rate;
   132   }
   134   return ret;
   135 }
   137 int
   138 SurvRateGroup::next_age_index() {
   139   TruncatedSeq* seq = get_seq(_region_num);
   140   double surv_rate = _g1p->get_new_prediction(seq);
   141   _accum_surv_rate += surv_rate;
   143   ++_region_num;
   144   return (int) ++_all_regions_allocated;
   145 }
   147 void
   148 SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
   149   guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
   150              "pre-condition" );
   151   guarantee( _surv_rate[age_in_group] <= 0.00001,
   152              "should only update each slot once" );
   154   double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;
   155   _surv_rate[age_in_group] = surv_rate;
   156   _surv_rate_pred[age_in_group]->add(surv_rate);
   157   if ((size_t)age_in_group < _summary_surv_rates_len) {
   158     _summary_surv_rates[age_in_group]->add(surv_rate);
   159     if ((size_t)(age_in_group+1) > _summary_surv_rates_max_len)
   160       _summary_surv_rates_max_len = age_in_group+1;
   161   }
   162 }
   164 void
   165 SurvRateGroup::all_surviving_words_recorded(bool propagate) {
   166   if (propagate && _region_num > 0) { // conservative
   167     double surv_rate = _surv_rate_pred[_region_num-1]->last();
   168     for (size_t i = _region_num; i < _stats_arrays_length; ++i) {
   169       guarantee( _surv_rate[i] <= 0.00001,
   170                  "the slot should not have been updated" );
   171       _surv_rate_pred[i]->add(surv_rate);
   172     }
   173   }
   175   double accum = 0.0;
   176   double pred = 0.0;
   177   for (size_t i = 0; i < _stats_arrays_length; ++i) {
   178     pred = _g1p->get_new_prediction(_surv_rate_pred[i]);
   179     if (pred > 1.0) pred = 1.0;
   180     accum += pred;
   181     _accum_surv_rate_pred[i] = accum;
   182     // gclog_or_tty->print_cr("age %3d, accum %10.2lf", i, accum);
   183   }
   184   _last_pred = pred;
   185 }
   187 #ifndef PRODUCT
   188 void
   189 SurvRateGroup::print() {
   190   gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries)",
   191                 _name, _region_num);
   192   for (size_t i = 0; i < _region_num; ++i) {
   193     gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%",
   194                   i, _surv_rate[i] * 100.0,
   195                   _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0);
   196   }
   197 }
   199 void
   200 SurvRateGroup::print_surv_rate_summary() {
   201   size_t length = _summary_surv_rates_max_len;
   202   if (length == 0)
   203     return;
   205   gclog_or_tty->print_cr("");
   206   gclog_or_tty->print_cr("%s Rate Summary (for up to age %d)", _name, length-1);
   207   gclog_or_tty->print_cr("      age range     survival rate (avg)      samples (avg)");
   208   gclog_or_tty->print_cr("  ---------------------------------------------------------");
   210   size_t index = 0;
   211   size_t limit = MIN2((int) length, 10);
   212   while (index < limit) {
   213     gclog_or_tty->print_cr("           %4d                 %6.2lf%%             %6.2lf",
   214                   index, _summary_surv_rates[index]->avg() * 100.0,
   215                   (double) _summary_surv_rates[index]->num());
   216     ++index;
   217   }
   219   gclog_or_tty->print_cr("  ---------------------------------------------------------");
   221   int num = 0;
   222   double sum = 0.0;
   223   int samples = 0;
   224   while (index < length) {
   225     ++num;
   226     sum += _summary_surv_rates[index]->avg() * 100.0;
   227     samples += _summary_surv_rates[index]->num();
   228     ++index;
   230     if (index == length || num % 10 == 0) {
   231       gclog_or_tty->print_cr("   %4d .. %4d                 %6.2lf%%             %6.2lf",
   232                     (index-1) / 10 * 10, index-1, sum / (double) num,
   233                     (double) samples / (double) num);
   234       sum = 0.0;
   235       num = 0;
   236       samples = 0;
   237     }
   238   }
   240   gclog_or_tty->print_cr("  ---------------------------------------------------------");
   241 }
   242 #endif // PRODUCT

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