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

 *

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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).

 *

 * 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_G1COLLECTIONSET_HPP

#define SHARE_VM_GC_G1_G1COLLECTIONSET_HPP

#include "gc/g1/collectionSetChooser.hpp"

#include "memory/allocation.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

class G1CollectedHeap;

class G1CollectorState;

class G1GCPhaseTimes;

class G1Policy;

class HeapRegion;

class G1CollectionSet VALUE_OBJ_CLASS_SPEC {

  G1CollectedHeap* _g1;

  G1Policy* _policy;

  CollectionSetChooser* _cset_chooser;

  uint _eden_region_length;

  uint _survivor_region_length;

  uint _old_region_length;

  // The head of the list (via "next_in_collection_set()") representing the

  // current collection set. Set from the incrementally built collection

  // set at the start of the pause.

  HeapRegion* _head;

  // The number of bytes in the collection set before the pause. Set from

  // the incrementally built collection set at the start of an evacuation

  // pause, and incremented in finalize_old_part() when adding old regions

  // (if any) to the collection set.

  size_t _bytes_used_before;

  size_t _recorded_rs_lengths;

  // The associated information that is maintained while the incremental

  // collection set is being built with young regions. Used to populate

  // the recorded info for the evacuation pause.

  enum CSetBuildType {

    Active,             // We are actively building the collection set

    Inactive            // We are not actively building the collection set

  };

  CSetBuildType _inc_build_state;

  // The head of the incrementally built collection set.

  HeapRegion* _inc_head;

  // The tail of the incrementally built collection set.

  HeapRegion* _inc_tail;

  // The number of bytes in the incrementally built collection set.

  // Used to set _collection_set_bytes_used_before at the start of

  // an evacuation pause.

  size_t _inc_bytes_used_before;

  // The RSet lengths recorded for regions in the CSet. It is updated

  // by the thread that adds a new region to the CSet. We assume that

  // only one thread can be allocating a new CSet region (currently,

  // it does so after taking the Heap_lock) hence no need to

  // synchronize updates to this field.

  size_t _inc_recorded_rs_lengths;

  // A concurrent refinement thread periodically samples the young

  // region RSets and needs to update _inc_recorded_rs_lengths as

  // the RSets grow. Instead of having to synchronize updates to that

  // field we accumulate them in this field and add it to

  // _inc_recorded_rs_lengths_diffs at the start of a GC.

  ssize_t _inc_recorded_rs_lengths_diffs;

  // The predicted elapsed time it will take to collect the regions in

  // the CSet. This is updated by the thread that adds a new region to

  // the CSet. See the comment for _inc_recorded_rs_lengths about

  // MT-safety assumptions.

  double _inc_predicted_elapsed_time_ms;

  // See the comment for _inc_recorded_rs_lengths_diffs.

  double _inc_predicted_elapsed_time_ms_diffs;

  G1CollectorState* collector_state();

  G1GCPhaseTimes* phase_times();

  double predict_region_elapsed_time_ms(HeapRegion* hr);

public:

  G1CollectionSet(G1CollectedHeap* g1h, G1Policy* policy);

  ~G1CollectionSet();

  CollectionSetChooser* cset_chooser();

  void init_region_lengths(uint eden_cset_region_length,

                           uint survivor_cset_region_length);

  void set_recorded_rs_lengths(size_t rs_lengths);

  uint region_length() const       { return young_region_length() +

                                            old_region_length(); }

  uint young_region_length() const { return eden_region_length() +

                                            survivor_region_length(); }

  uint eden_region_length() const     { return _eden_region_length;     }

  uint survivor_region_length() const { return _survivor_region_length; }

  uint old_region_length() const      { return _old_region_length;      }

  // Incremental CSet Support

  // The head of the incrementally built collection set.

  HeapRegion* inc_head() { return _inc_head; }

  // The tail of the incrementally built collection set.

  HeapRegion* inc_tail() { return _inc_tail; }

  // Initialize incremental collection set info.

  void start_incremental_building();

  // Perform any final calculations on the incremental CSet fields

  // before we can use them.

  void finalize_incremental_building();

  void clear_incremental() {

    _inc_head = NULL;

    _inc_tail = NULL;

  }

  // Stop adding regions to the incremental collection set

  void stop_incremental_building() { _inc_build_state = Inactive; }

  // The head of the list (via "next_in_collection_set()") representing the

  // current collection set.

  HeapRegion* head() { return _head; }

  void clear_head() { _head = NULL; }

  size_t recorded_rs_lengths() { return _recorded_rs_lengths; }

  size_t bytes_used_before() const {

    return _bytes_used_before;

  }

  void reset_bytes_used_before() {

    _bytes_used_before = 0;

  }

  // Choose a new collection set.  Marks the chosen regions as being

  // "in_collection_set", and links them together.  The head and number of

  // the collection set are available via access methods.

  double finalize_young_part(double target_pause_time_ms);

  void finalize_old_part(double time_remaining_ms);

  // Add old region "hr" to the CSet.

  void add_old_region(HeapRegion* hr);

  // Update information about hr in the aggregated information for

  // the incrementally built collection set.

  void update_young_region_prediction(HeapRegion* hr, size_t new_rs_length);

  // Add hr to the LHS of the incremental collection set.

  void add_eden_region(HeapRegion* hr);

  // Add hr to the RHS of the incremental collection set.

  void add_survivor_regions(HeapRegion* hr);

#ifndef PRODUCT

  void print(HeapRegion* list_head, outputStream* st);

#endif // !PRODUCT

private:

  // Update the incremental cset information when adding a region

  // (should not be called directly).

  void add_young_region_common(HeapRegion* hr);

};

#endif // SHARE_VM_GC_G1_G1COLLECTIONSET_HPP