1 /*
   2  * Copyright (c) 1997, 2015, 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 #include "precompiled.hpp"
  26 #include "gc/shared/ageTable.hpp"
  27 #include "gc/shared/collectedHeap.hpp"
  28 #include "gc/shared/collectorPolicy.hpp"
  29 #include "gc/shared/gcPolicyCounters.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "logging/log.hpp"
  32 #include "utilities/copy.hpp"
  33 
  34 /* Copyright (c) 1992, 2015, Oracle and/or its affiliates, and Stanford University.
  35    See the LICENSE file for license information. */
  36 
  37 ageTable::ageTable(bool global) {
  38 
  39   clear();
  40 
  41   if (UsePerfData && global) {
  42 
  43     ResourceMark rm;
  44     EXCEPTION_MARK;
  45 
  46     const char* agetable_ns = "generation.0.agetable";
  47     const char* bytes_ns = PerfDataManager::name_space(agetable_ns, "bytes");
  48 
  49     for(int age = 0; age < table_size; age ++) {
  50       char age_name[10];
  51       jio_snprintf(age_name, sizeof(age_name), "%2.2d", age);
  52       const char* cname = PerfDataManager::counter_name(bytes_ns, age_name);
  53       _perf_sizes[age] = PerfDataManager::create_variable(SUN_GC, cname,
  54                                                           PerfData::U_Bytes,
  55                                                           CHECK);
  56     }
  57 
  58     const char* cname = PerfDataManager::counter_name(agetable_ns, "size");
  59     PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_None,
  60                                      table_size, CHECK);
  61   }
  62 }
  63 
  64 void ageTable::clear() {
  65   for (size_t* p = sizes; p < sizes + table_size; ++p) {
  66     *p = 0;
  67   }
  68 }
  69 
  70 void ageTable::merge(ageTable* subTable) {
  71   for (int i = 0; i < table_size; i++) {
  72     sizes[i]+= subTable->sizes[i];
  73   }
  74 }
  75 
  76 uint ageTable::compute_tenuring_threshold(size_t survivor_capacity, GCPolicyCounters* gc_counters) {
  77   size_t desired_survivor_size = (size_t)((((double) survivor_capacity)*TargetSurvivorRatio)/100);
  78   uint result;
  79 
  80   if (AlwaysTenure || NeverTenure) {
  81     assert(MaxTenuringThreshold == 0 || MaxTenuringThreshold == markOopDesc::max_age + 1,
  82            "MaxTenuringThreshold should be 0 or markOopDesc::max_age + 1, but is " UINTX_FORMAT, MaxTenuringThreshold);
  83     result = MaxTenuringThreshold;
  84   } else {
  85     size_t total = 0;
  86     uint age = 1;
  87     assert(sizes[0] == 0, "no objects with age zero should be recorded");
  88     while (age < table_size) {
  89       total += sizes[age];
  90       // check if including objects of age 'age' made us pass the desired
  91       // size, if so 'age' is the new threshold
  92       if (total > desired_survivor_size) break;
  93       age++;
  94     }
  95     result = age < MaxTenuringThreshold ? age : MaxTenuringThreshold;
  96   }
  97 

  98 
  99   log_debug(gc, age)("Desired survivor size " SIZE_FORMAT " bytes, new threshold " UINTX_FORMAT " (max threshold " UINTX_FORMAT ")",



 100                      desired_survivor_size*oopSize, (uintx) result, MaxTenuringThreshold);

 101 
 102   if (Log<LOG_TAGS(gc, age)>::is_trace() || UsePerfData) {
 103     size_t total = 0;
 104     uint age = 1;
 105     while (age < table_size) {
 106       total += sizes[age];
 107       if (sizes[age] > 0) {
 108         log_trace(gc, age)("- age %3u: " SIZE_FORMAT_W(10) " bytes, " SIZE_FORMAT_W(10) " total",

 109                             age, sizes[age]*oopSize, total*oopSize);

 110       }
 111       if (UsePerfData) {
 112         _perf_sizes[age]->set_value(sizes[age]*oopSize);
 113       }
 114       age++;
 115     }
 116     if (UsePerfData) {
 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 }
--- EOF ---