/*

 * Copyright (c) 2001, 2019, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_GC_G1_G1REMSET_HPP

#define SHARE_GC_G1_G1REMSET_HPP

#include "gc/g1/g1CardTable.hpp"

#include "gc/g1/g1OopClosures.hpp"

#include "gc/g1/g1GCPhaseTimes.hpp"

#include "gc/g1/g1RemSetSummary.hpp"

#include "gc/g1/heapRegion.hpp"

#include "memory/allocation.hpp"

#include "memory/iterator.hpp"

#include "utilities/ticks.hpp"

// A G1RemSet provides ways of iterating over pointers into a selected

// collection set.

class BitMap;

class CardTableBarrierSet;

class G1BlockOffsetTable;

class CodeBlobClosure;

class G1CollectedHeap;

class G1CMBitMap;

class G1HotCardCache;

class G1RemSetScanState;

class G1ParScanThreadState;

class G1ParScanThreadStateSet;

class G1Policy;

class G1ScanCardClosure;

class HeapRegionClaimer;

// A G1RemSet in which each heap region has a rem set that records the

// external heap references into it.  Uses a mod ref bs to track updates,

// so that they can be used to update the individual region remsets.

class G1RemSet: public CHeapObj<mtGC> {

private:

  G1RemSetScanState* _scan_state;

  G1RemSetSummary _prev_period_summary;

  G1CollectedHeap* _g1h;

  G1CardTable*           _ct;

  G1Policy*              _g1p;

  G1HotCardCache*        _hot_card_cache;

  void print_merge_heap_roots_stats();

public:

  typedef CardTable::CardValue CardValue;

  // Gives an approximation on how many threads can be expected to add records to

  // a remembered set in parallel. This can be used for sizing data structures to

  // decrease performance losses due to data structure sharing.

  // Examples for quantities that influence this value are the maximum number of

  // mutator threads, maximum number of concurrent refinement or GC threads.

  static uint num_par_rem_sets();

  // Initialize data that depends on the heap size being known.

  void initialize(size_t capacity, uint max_regions);

  G1RemSet(G1CollectedHeap* g1h,

           G1CardTable* ct,

           G1HotCardCache* hot_card_cache);

  ~G1RemSet();

  // Scan all cards in the non-collection set regions that potentially contain

  // references into the current whole collection set.

  void scan_heap_roots(G1ParScanThreadState* pss,

                       uint worker_id,

                       G1GCPhaseTimes::GCParPhases scan_phase,

                       G1GCPhaseTimes::GCParPhases objcopy_phase);

  // Merge cards from various sources (remembered sets, hot card cache, log buffers)

  // and calculate the cards that need to be scanned later (via scan_heap_roots()).

  // If initial_evacuation is set, this is called during the initial evacuation.

  void merge_heap_roots(bool initial_evacuation);

  // Prepare for and cleanup after scanning the heap roots. Must be called

  // once before and after in sequential code.

  void prepare_for_scan_heap_roots();

  // Cleans the card table from temporary duplicate detection information.

  void cleanup_after_scan_heap_roots();

  // Do work for regions in the current increment of the collection set, scanning

  // non-card based (heap) roots.

  void scan_collection_set_regions(G1ParScanThreadState* pss,

                                   uint worker_id,

                                   G1GCPhaseTimes::GCParPhases scan_phase,

                                   G1GCPhaseTimes::GCParPhases coderoots_phase,

                                   G1GCPhaseTimes::GCParPhases objcopy_phase);

  // Two methods for concurrent refinement support, executed concurrently to

  // the mutator:

  // Cleans the card at "*card_ptr_addr" before refinement, returns true iff the

  // card needs later refinement. Note that "*card_ptr_addr" could be updated to

  // a different card due to use of hot card cache.

  bool clean_card_before_refine(CardValue** const card_ptr_addr);

  // Refine the region corresponding to "card_ptr". Must be called after

  // being filtered by clean_card_before_refine(), and after proper

  // fence/synchronization.

  void refine_card_concurrently(CardValue* const card_ptr,

                                const uint worker_id);

  // Print accumulated summary info from the start of the VM.

  void print_summary_info();

  // Print accumulated summary info from the last time called.

  void print_periodic_summary_info(const char* header, uint period_count);

  // Rebuilds the remembered set by scanning from bottom to TARS for all regions

  // using the given work gang.

  void rebuild_rem_set(G1ConcurrentMark* cm, WorkGang* workers, uint worker_id_offset);

};

#endif // SHARE_GC_G1_G1REMSET_HPP