/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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.

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#ifndef SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP

#define SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP

#include "gc/shared/concurrentGCThread.hpp"

// The Concurrent Mark GC Thread triggers the parallel G1CMConcurrentMarkingTasks

// as well as handling various marking cleanup.

class G1ConcurrentMark;

class G1CollectorPolicy;

class ConcurrentMarkThread: public ConcurrentGCThread {

  friend class VMStructs;

  double _vtime_start;  // Initial virtual time.

  double _vtime_accum;  // Accumulated virtual time.

  double _vtime_mark_accum;

  G1ConcurrentMark*                _cm;

  enum State {

    Idle,

    Started,

    InProgress

  };

  volatile State _state;

  void sleepBeforeNextCycle();

  void delay_to_keep_mmu(G1CollectorPolicy* g1_policy, bool remark);

  void run_service();

  void stop_service();

 public:

  // Constructor

  ConcurrentMarkThread(G1ConcurrentMark* cm);

  // Total virtual time so far for this thread and concurrent marking tasks.

  double vtime_accum();

  // Marking virtual time so far this thread and concurrent marking tasks.

  double vtime_mark_accum();

  G1ConcurrentMark* cm()   { return _cm; }

  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }

  bool idle()              { return _state == Idle; }

  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }

  bool started()           { return _state == Started; }

  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }

  bool in_progress()       { return _state == InProgress; }

  // Returns true from the moment a marking cycle is

  // initiated (during the initial-mark pause when started() is set)

  // to the moment when the cycle completes (just after the next

  // marking bitmap has been cleared and in_progress() is

  // cleared). While during_cycle() is true we will not start another cycle

  // so that cycles do not overlap. We cannot use just in_progress()

  // as the CM thread might take some time to wake up before noticing

  // that started() is set and set in_progress().

  bool during_cycle()      { return !idle(); }

};

#endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP