1 /*
   2  * Copyright (c) 1997, 2009, 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  */
  24 
  25 /* Copyright (c) 1992-2009 Oracle and/or its affiliates, and Stanford University.
  26    See the LICENSE file for license information. */
  27 
  28 # include "incls/_precompiled.incl"
  29 # include "incls/_ageTable.cpp.incl"
  30 
  31 ageTable::ageTable(bool global) {
  32 
  33   clear();
  34 
  35   if (UsePerfData && global) {
  36 
  37     ResourceMark rm;
  38     EXCEPTION_MARK;
  39 
  40     const char* agetable_ns = "generation.0.agetable";
  41     const char* bytes_ns = PerfDataManager::name_space(agetable_ns, "bytes");
  42 
  43     for(int age = 0; age < table_size; age ++) {
  44       char age_name[10];
  45       jio_snprintf(age_name, sizeof(age_name), "%2.2d", age);
  46       const char* cname = PerfDataManager::counter_name(bytes_ns, age_name);
  47       _perf_sizes[age] = PerfDataManager::create_variable(SUN_GC, cname,
  48                                                           PerfData::U_Bytes,
  49                                                           CHECK);
  50     }
  51 
  52     const char* cname = PerfDataManager::counter_name(agetable_ns, "size");
  53     PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_None,
  54                                      table_size, CHECK);
  55   }
  56 }
  57 
  58 void ageTable::clear() {
  59   for (size_t* p = sizes; p < sizes + table_size; ++p) {
  60     *p = 0;
  61   }
  62 }
  63 
  64 void ageTable::merge(ageTable* subTable) {
  65   for (int i = 0; i < table_size; i++) {
  66     sizes[i]+= subTable->sizes[i];
  67   }
  68 }
  69 
  70 void ageTable::merge_par(ageTable* subTable) {
  71   for (int i = 0; i < table_size; i++) {
  72     Atomic::add_ptr(subTable->sizes[i], &sizes[i]);
  73   }
  74 }
  75 
  76 int ageTable::compute_tenuring_threshold(size_t survivor_capacity) {
  77   size_t desired_survivor_size = (size_t)((((double) survivor_capacity)*TargetSurvivorRatio)/100);
  78   size_t total = 0;
  79   int age = 1;
  80   assert(sizes[0] == 0, "no objects with age zero should be recorded");
  81   while (age < table_size) {
  82     total += sizes[age];
  83     // check if including objects of age 'age' made us pass the desired
  84     // size, if so 'age' is the new threshold
  85     if (total > desired_survivor_size) break;
  86     age++;
  87   }
  88   int result = age < MaxTenuringThreshold ? age : MaxTenuringThreshold;
  89 
  90   if (PrintTenuringDistribution || UsePerfData) {
  91 
  92     if (PrintTenuringDistribution) {
  93       gclog_or_tty->cr();
  94       gclog_or_tty->print_cr("Desired survivor size %ld bytes, new threshold %d (max %d)",
  95         desired_survivor_size*oopSize, result, MaxTenuringThreshold);
  96     }
  97 
  98     total = 0;
  99     age = 1;
 100     while (age < table_size) {
 101       total += sizes[age];
 102       if (sizes[age] > 0) {
 103         if (PrintTenuringDistribution) {
 104           gclog_or_tty->print_cr("- age %3d: %10ld bytes, %10ld total",
 105             age, sizes[age]*oopSize, total*oopSize);
 106         }
 107       }
 108       if (UsePerfData) {
 109         _perf_sizes[age]->set_value(sizes[age]*oopSize);
 110       }
 111       age++;
 112     }
 113     if (UsePerfData) {
 114       SharedHeap* sh = SharedHeap::heap();
 115       CollectorPolicy* policy = sh->collector_policy();
 116       GCPolicyCounters* gc_counters = policy->counters();
 117       gc_counters->tenuring_threshold()->set_value(result);
 118       gc_counters->desired_survivor_size()->set_value(
 119         desired_survivor_size*oopSize);
 120     }
 121   }
 122 
 123   return result;
 124 }