view src/share/vm/gc_implementation/g1/concurrentG1RefineThread.hpp @ 2034:7e37af9d69ef

7011379: G1: overly long concurrent marking cycles Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads. Reviewed-by: johnc, ysr
author tonyp
date Wed, 19 Jan 2011 09:35:17 -0500
parents c18cbe5936b8
children
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/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP

#include "gc_implementation/shared/concurrentGCThread.hpp"

// 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.
  int _worker_id;
  int _worker_id_offset;

  // The refinement threads collection is linked list. A predecessor can activate a successor
  // when the number of the rset update buffer crosses a certain threshold. A successor
  // would self-deactivate when the number of the buffers falls below the threshold.
  bool _active;
  ConcurrentG1RefineThread* _next;
  Monitor* _monitor;
  ConcurrentG1Refine* _cg1r;

  int _thread_threshold_step;
  // This thread activation threshold
  int _threshold;
  // This thread deactivation threshold
  int _deactivation_threshold;

  void sample_young_list_rs_lengths();
  void run_young_rs_sampling();
  void wait_for_completed_buffers();

  void set_active(bool x) { _active = x; }
  bool is_active();
  void activate();
  void deactivate();

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

public:
  virtual void run();
  // Constructor
  ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread* next,
                           int worker_id_offset, int worker_id);

  void initialize();

  // Printing
  void print() const;
  void print_on(outputStream* st) const;

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

  ConcurrentG1Refine* cg1r() { return _cg1r;     }

  // Yield for GC
  void yield();
  // shutdown
  void stop();
};

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP