/*

 * Copyright (c) 2001, 2009, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

// 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();

};