view src/share/vm/gc_implementation/shared/ageTable.hpp @ 577:58054a18d735

6484959: G1: introduce survivor spaces 6797754: G1: combined bugfix Summary: Implemented a policy to control G1 survivor space parameters. Reviewed-by: tonyp, iveresov
author apetrusenko
date Fri, 06 Feb 2009 01:38:50 +0300
parents a61af66fc99e
children 0fbdb4381b99
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 * Copyright 1997-2003 Sun Microsystems, Inc.  All Rights Reserved.
 * 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 if you need additional information or
 * have any questions.

/* Copyright 1992 Sun Microsystems, Inc. and Stanford University.
   See the LICENSE file for license information. */

// Age table for adaptive feedback-mediated tenuring (scavenging)
// Note: all sizes are in oops

class ageTable VALUE_OBJ_CLASS_SPEC {
  friend class VMStructs;

  // constants
  enum { table_size = markOopDesc::max_age + 1 };

  // instance variables
  size_t sizes[table_size];

  // constructor.  "global" indicates that this is the global age table
  // (as opposed to gc-thread-local)
  ageTable(bool global = true);

  // clear table
  void clear();

  // add entry
  void add(oop p, size_t oop_size) {
    int age = p->age();
    assert(age > 0 && age < table_size, "invalid age of object");
    sizes[age] += oop_size;

  // Merge another age table with the current one.  Used
  // for parallel young generation gc.
  void merge(ageTable* subTable);
  void merge_par(ageTable* subTable);

  // calculate new tenuring threshold based on age information
  int compute_tenuring_threshold(size_t survivor_capacity);

  PerfVariable* _perf_sizes[table_size];