view src/share/vm/gc_implementation/g1/concurrentG1RefineThread.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 37f87013dfd8
children 315a5d70b295
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/*
 * Copyright 2001-2007 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.
 *
 */

// Forward Decl.
class ConcurrentG1Refine;

// The G1 Concurrent Refinement Thread (could be several in the future).

class ConcurrentG1RefineThread: public ConcurrentGCThread {
  friend class VMStructs;
  friend class G1CollectedHeap;

  double _vtime_start;  // Initial virtual time.
  double _vtime_accum;  // Initial virtual time.

 public:
  virtual void run();

 private:
  ConcurrentG1Refine*              _cg1r;
  bool                             _started;
  bool                             _in_progress;
  volatile bool                    _restart;

  COTracker                        _co_tracker;
  double                           _interval_ms;

  bool                             _do_traversal;

  void decreaseInterval(int processing_time_ms) {
    double min_interval_ms = (double) processing_time_ms;
    _interval_ms = 0.8 * _interval_ms;
    if (_interval_ms < min_interval_ms)
      _interval_ms = min_interval_ms;
  }
  void increaseInterval(int processing_time_ms) {
    double max_interval_ms = 9.0 * (double) processing_time_ms;
    _interval_ms = 1.1 * _interval_ms;
    if (max_interval_ms > 0 && _interval_ms > max_interval_ms)
      _interval_ms = max_interval_ms;
  }

  void sleepBeforeNextCycle();

  void traversalBasedRefinement();

  void queueBasedRefinement();

  // For use by G1CollectedHeap, which is a friend.
  static SuspendibleThreadSet* sts() { return &_sts; }

 public:
  // Constructor
  ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r);

  // Printing
  void print();

  // Total virtual time so far.
  double vtime_accum() { return _vtime_accum; }

  ConcurrentG1Refine* cg1r()                     { return _cg1r;     }


  void            set_started()                  { _started = true;   }
  void            clear_started()                { _started = false;  }
  bool            started()                      { return _started;   }

  void            set_in_progress()              { _in_progress = true;   }
  void            clear_in_progress()            { _in_progress = false;  }
  bool            in_progress()                  { return _in_progress;   }

  void            set_do_traversal(bool b);
  bool            do_traversal() { return _do_traversal; }

  void            sample_young_list_rs_lengths();

  // Yield for GC
  void            yield();

  // shutdown
  static void stop();
};