view src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp @ 438:122d10c82f3f

6765804: GC "dead ratios" should be unsigned Reviewed-by: ysr, tonyp
author jcoomes
date Wed, 29 Oct 2008 06:30:02 -0700
parents a61af66fc99e
children ad8c8ca4ab0f
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 * Copyright 2001-2002 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.

// A PSMarkSweepDecorator is used to add "ParallelScavenge" style mark sweep operations
// to a MutableSpace.

class ObjectStartArray;

class PSMarkSweepDecorator: public CHeapObj {
  static PSMarkSweepDecorator* _destination_decorator;

  MutableSpace* _space;
  ObjectStartArray* _start_array;
  HeapWord* _first_dead;
  HeapWord* _end_of_live;
  HeapWord* _compaction_top;
  size_t _allowed_dead_ratio;

  bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q,
                        size_t word_len);

  PSMarkSweepDecorator(MutableSpace* space, ObjectStartArray* start_array,
                       size_t allowed_dead_ratio) :
    _space(space), _start_array(start_array),
    _allowed_dead_ratio(allowed_dead_ratio) { }

  // During a compacting collection, we need to collapse objects into
  // spaces in a given order. We want to fill space A, space B, and so
  // on. The code that controls that order is in the following methods.
  static void set_destination_decorator_tenured();
  static void set_destination_decorator_perm_gen();
  static void advance_destination_decorator();
  static PSMarkSweepDecorator* destination_decorator();

  // Accessors
  MutableSpace* space()                     { return _space; }
  ObjectStartArray* start_array()           { return _start_array; }

  HeapWord* compaction_top()                { return _compaction_top; }
  void set_compaction_top(HeapWord* value)  { _compaction_top = value; }

  size_t allowed_dead_ratio()               { return _allowed_dead_ratio; }
  void set_allowed_dead_ratio(size_t value) { _allowed_dead_ratio = value; }

  // Work methods
  void adjust_pointers();
  void precompact();
  void compact(bool mangle_free_space);