view src/share/vm/gc_implementation/parallelScavenge/generationSizer.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents d1605aabd0a1
children c18cbe5936b8
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/*
 * Copyright 2001-2008 Sun Microsystems, Inc.  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.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

// There is a nice batch of tested generation sizing code in
// TwoGenerationCollectorPolicy. Lets reuse it!

class GenerationSizer : public TwoGenerationCollectorPolicy {
 public:
  GenerationSizer() {
    // Partial init only!
    initialize_flags();
    initialize_size_info();
  }

  void initialize_flags() {
    // Do basic sizing work
    this->TwoGenerationCollectorPolicy::initialize_flags();

    // If the user hasn't explicitly set the number of worker
    // threads, set the count.
    assert(UseSerialGC ||
           !FLAG_IS_DEFAULT(ParallelGCThreads) ||
           (ParallelGCThreads > 0),
           "ParallelGCThreads should be set before flag initialization");

    // The survivor ratio's are calculated "raw", unlike the
    // default gc, which adds 2 to the ratio value. We need to
    // make sure the values are valid before using them.
    if (MinSurvivorRatio < 3) {
      MinSurvivorRatio = 3;
    }

    if (InitialSurvivorRatio < 3) {
      InitialSurvivorRatio = 3;
    }
  }

  size_t min_young_gen_size() { return _min_gen0_size; }
  size_t young_gen_size()     { return _initial_gen0_size; }
  size_t max_young_gen_size() { return _max_gen0_size; }

  size_t min_old_gen_size()   { return _min_gen1_size; }
  size_t old_gen_size()       { return _initial_gen1_size; }
  size_t max_old_gen_size()   { return _max_gen1_size; }

  size_t perm_gen_size()      { return PermSize; }
  size_t max_perm_gen_size()  { return MaxPermSize; }
};