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

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 *

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 * 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,

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#ifndef SHARE_VM_GC_G1_G1COLLECTORSTATE_HPP

#define SHARE_VM_GC_G1_G1COLLECTORSTATE_HPP

#include "gc/g1/g1YCTypes.hpp"

#include "utilities/globalDefinitions.hpp"

// Various state variables that indicate

// the phase of the G1 collection.

class G1CollectorState {

  // Indicates whether we are in "full young" or "mixed" GC mode.

  bool _gcs_are_young;

  // Was the last GC "young"?

  bool _last_gc_was_young;

  // Is this the "last young GC" before we start doing mixed GCs?

  // Set after a concurrent mark has completed.

  bool _last_young_gc;

  // If initiate_conc_mark_if_possible() is set at the beginning of a

  // pause, it is a suggestion that the pause should start a marking

  // cycle by doing the initial-mark work. However, it is possible

  // that the concurrent marking thread is still finishing up the

  // previous marking cycle (e.g., clearing the next marking

  // bitmap). If that is the case we cannot start a new cycle and

  // we'll have to wait for the concurrent marking thread to finish

  // what it is doing. In this case we will postpone the marking cycle

  // initiation decision for the next pause. When we eventually decide

  // to start a cycle, we will set _during_initial_mark_pause which

  // will stay true until the end of the initial-mark pause and it's

  // the condition that indicates that a pause is doing the

  // initial-mark work.

  volatile bool _during_initial_mark_pause;

  // At the end of a pause we check the heap occupancy and we decide

  // whether we will start a marking cycle during the next pause. If

  // we decide that we want to do that, we will set this parameter to

  // true. So, this parameter will stay true between the end of a

  // pause and the beginning of a subsequent pause (not necessarily

  // the next one, see the comments on the next field) when we decide

  // that we will indeed start a marking cycle and do the initial-mark

  // work.

  volatile bool _initiate_conc_mark_if_possible;

  // NOTE: if some of these are synonyms for others,

  // the redundant fields should be eliminated. XXX

  bool _during_marking;

  bool _mark_in_progress;

  bool _in_marking_window;

  bool _in_marking_window_im;

  bool _full_collection;

  public:

    G1CollectorState() :

      _gcs_are_young(true),

      _last_gc_was_young(false),

      _last_young_gc(false),

      _during_initial_mark_pause(false),

      _initiate_conc_mark_if_possible(false),

      _during_marking(false),

      _mark_in_progress(false),

      _in_marking_window(false),

      _in_marking_window_im(false),

      _full_collection(false) {}

  // Setters

  void set_gcs_are_young(bool v) { _gcs_are_young = v; }

  void set_last_gc_was_young(bool v) { _last_gc_was_young = v; }

  void set_during_initial_mark_pause(bool v) { _during_initial_mark_pause = v; }

  void set_initiate_conc_mark_if_possible(bool v) { _initiate_conc_mark_if_possible = v; }

  void set_during_marking(bool v) { _during_marking = v; }

  void set_mark_in_progress(bool v) { _mark_in_progress = v; }

  void set_in_marking_window(bool v) { _in_marking_window = v; }

  void set_in_marking_window_im(bool v) { _in_marking_window_im = v; }

  void set_full_collection(bool v) { _full_collection = v; }

  // Getters

  bool gcs_are_young() const { return _gcs_are_young; }

  bool last_gc_was_young() const { return _last_gc_was_young; }

  bool last_young_gc() const { return _last_young_gc; }

  bool during_initial_mark_pause() const { return _during_initial_mark_pause; }

  bool initiate_conc_mark_if_possible() const { return _initiate_conc_mark_if_possible; }

  bool during_marking() const { return _during_marking; }

  bool mark_in_progress() const { return _mark_in_progress; }

  bool in_marking_window() const { return _in_marking_window; }

  bool in_marking_window_im() const { return _in_marking_window_im; }

  bool full_collection() const { return _full_collection; }

  // Composite booleans (clients worry about flickering)

  bool during_concurrent_mark() const {

    return (_in_marking_window && !_in_marking_window_im);

  }

  G1YCType yc_type() const {

    if (during_initial_mark_pause()) {

      return InitialMark;

    } else if (mark_in_progress()) {

      return DuringMark;

    } else if (gcs_are_young()) {

      return Normal;

    } else {

      return Mixed;

    }

  }

};

#endif // SHARE_VM_GC_G1_G1COLLECTORSTATE_HPP