1 /*
   2  * Copyright (c) 2001, 2008, 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 // There is a nice batch of tested generation sizing code in
  26 // TwoGenerationCollectorPolicy. Lets reuse it!
  27 
  28 class GenerationSizer : public TwoGenerationCollectorPolicy {
  29  public:
  30   GenerationSizer() {
  31     // Partial init only!
  32     initialize_flags();
  33     initialize_size_info();
  34   }
  35 
  36   void initialize_flags() {
  37     // Do basic sizing work
  38     this->TwoGenerationCollectorPolicy::initialize_flags();
  39 
  40     // If the user hasn't explicitly set the number of worker
  41     // threads, set the count.
  42     assert(UseSerialGC ||
  43            !FLAG_IS_DEFAULT(ParallelGCThreads) ||
  44            (ParallelGCThreads > 0),
  45            "ParallelGCThreads should be set before flag initialization");
  46 
  47     // The survivor ratio's are calculated "raw", unlike the
  48     // default gc, which adds 2 to the ratio value. We need to
  49     // make sure the values are valid before using them.
  50     if (MinSurvivorRatio < 3) {
  51       MinSurvivorRatio = 3;
  52     }
  53 
  54     if (InitialSurvivorRatio < 3) {
  55       InitialSurvivorRatio = 3;
  56     }
  57   }
  58 
  59   size_t min_young_gen_size() { return _min_gen0_size; }
  60   size_t young_gen_size()     { return _initial_gen0_size; }
  61   size_t max_young_gen_size() { return _max_gen0_size; }
  62 
  63   size_t min_old_gen_size()   { return _min_gen1_size; }
  64   size_t old_gen_size()       { return _initial_gen1_size; }
  65   size_t max_old_gen_size()   { return _max_gen1_size; }
  66 
  67   size_t perm_gen_size()      { return PermSize; }
  68   size_t max_perm_gen_size()  { return MaxPermSize; }
  69 };