view src/share/vm/gc_implementation/parallelScavenge/asPSOldGen.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 a61af66fc99e
children c18cbe5936b8
line wrap: on
line source

/*
 * Copyright 2003 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.
 *
 */

class ASPSOldGen : public PSOldGen {
  friend class VMStructs;
  size_t _gen_size_limit;  // Largest size the generation's reserved size
                           // can grow.
 public:
  ASPSOldGen(size_t initial_byte_size,
             size_t minimum_byte_size,
             size_t byte_size_limit,
             const char* gen_name, int level);
  ASPSOldGen(PSVirtualSpace* vs,
             size_t initial_byte_size,
             size_t minimum_byte_size,
             size_t byte_size_limit,
             const char* gen_name, int level);
  size_t gen_size_limit()               { return _gen_size_limit; }
  size_t max_gen_size()                 { return _reserved.byte_size(); }
  void set_gen_size_limit(size_t v)     { _gen_size_limit = v; }

  // After a shrink or expand reset the generation
  void reset_after_change();

  // Return number of bytes that the virtual space in the generation is willing
  // to expand or contract.  The results from these methods should feed into the
  // decisions about adjusting the virtual space.
  size_t available_for_expansion();
  size_t available_for_contraction();

  // Accessors
  void set_reserved(MemRegion v) { _reserved = v; }

  // Debugging support
  virtual const char* short_name() const { return "ASPSOldGen"; }
};