/*

 * 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_MEMORY_METASPACE_CHUNKMANAGER_HPP

#define SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP

#include "memory/allocation.hpp"

#include "memory/binaryTreeDictionary.hpp"

#include "memory/freeList.hpp"

#include "memory/metaspace/metachunk.hpp"

#include "memory/metaspace/metaspaceStatistics.hpp"

#include "memory/metaspaceChunkFreeListSummary.hpp"

#include "utilities/globalDefinitions.hpp"

class ChunkManagerTest;

namespace metaspace {

typedef class FreeList<Metachunk> ChunkList;

typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;

// Manages the global free lists of chunks.

class ChunkManager : public CHeapObj<mtInternal> {

  friend class ::ChunkManagerTest;

  // Free list of chunks of different sizes.

  //   SpecializedChunk

  //   SmallChunk

  //   MediumChunk

  ChunkList _free_chunks[NumberOfFreeLists];

  // Whether or not this is the class chunkmanager.

  const bool _is_class;

  // Return non-humongous chunk list by its index.

  ChunkList* free_chunks(ChunkIndex index);

  // Returns non-humongous chunk list for the given chunk word size.

  ChunkList* find_free_chunks_list(size_t word_size);

  //   HumongousChunk

  ChunkTreeDictionary _humongous_dictionary;

  // Returns the humongous chunk dictionary.

  ChunkTreeDictionary* humongous_dictionary() {

    return &_humongous_dictionary;

  }

  // Size, in metaspace words, of all chunks managed by this ChunkManager

  size_t _free_chunks_total;

  // Number of chunks in this ChunkManager

  size_t _free_chunks_count;

  // Update counters after a chunk was added or removed removed.

  void account_for_added_chunk(const Metachunk* c);

  void account_for_removed_chunk(const Metachunk* c);

  size_t sum_free_chunks();

  size_t sum_free_chunks_count();

  void locked_verify_free_chunks_total();

  void slow_locked_verify_free_chunks_total() {

    if (VerifyMetaspace) {

      locked_verify_free_chunks_total();

    }

  }

  void locked_verify_free_chunks_count();

  void slow_locked_verify_free_chunks_count() {

    if (VerifyMetaspace) {

      locked_verify_free_chunks_count();

    }

  }

  // Given a pointer to a chunk, attempts to merge it with neighboring

  // free chunks to form a bigger chunk. Returns true if successful.

  bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type);

  // Helper for chunk merging:

  //  Given an address range with 1-n chunks which are all supposed to be

  //  free and hence currently managed by this ChunkManager, remove them

  //  from this ChunkManager and mark them as invalid.

  // - This does not correct the occupancy map.

  // - This does not adjust the counters in ChunkManager.

  // - Does not adjust container count counter in containing VirtualSpaceNode.

  // Returns number of chunks removed.

  int remove_chunks_in_area(MetaWord* p, size_t word_size);

  // Helper for chunk splitting: given a target chunk size and a larger free chunk,

  // split up the larger chunk into n smaller chunks, at least one of which should be

  // the target chunk of target chunk size. The smaller chunks, including the target

  // chunk, are returned to the freelist. The pointer to the target chunk is returned.

  // Note that this chunk is supposed to be removed from the freelist right away.

  Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk);

 public:

  ChunkManager(bool is_class);

  // Add or delete (return) a chunk to the global freelist.

  Metachunk* chunk_freelist_allocate(size_t word_size);

  // Map a size to a list index assuming that there are lists

  // for special, small, medium, and humongous chunks.

  ChunkIndex list_index(size_t size);

  // Map a given index to the chunk size.

  size_t size_by_index(ChunkIndex index) const;

  bool is_class() const { return _is_class; }

  // Convenience accessors.

  size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); }

  size_t small_chunk_word_size() const { return size_by_index(SmallIndex); }

  size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); }

  // Take a chunk from the ChunkManager. The chunk is expected to be in

  // the chunk manager (the freelist if non-humongous, the dictionary if

  // humongous).

  void remove_chunk(Metachunk* chunk);

  // Return a single chunk of type index to the ChunkManager.

  void return_single_chunk(Metachunk* chunk);

  // Add the simple linked list of chunks to the freelist of chunks

  // of type index.

  void return_chunk_list(Metachunk* chunk);

  // Total of the space in the free chunks list

  size_t free_chunks_total_words();

  size_t free_chunks_total_bytes();

  // Number of chunks in the free chunks list

  size_t free_chunks_count();

  // Remove from a list by size.  Selects list based on size of chunk.

  Metachunk* free_chunks_get(size_t chunk_word_size);

#define index_bounds_check(index)                                         \

  assert(is_valid_chunktype(index), "Bad index: %d", (int) index)

  size_t num_free_chunks(ChunkIndex index) const {

    index_bounds_check(index);

    if (index == HumongousIndex) {

      return _humongous_dictionary.total_free_blocks();

    }

    ssize_t count = _free_chunks[index].count();

    return count == -1 ? 0 : (size_t) count;

  }

  size_t size_free_chunks_in_bytes(ChunkIndex index) const {

    index_bounds_check(index);

    size_t word_size = 0;

    if (index == HumongousIndex) {

      word_size = _humongous_dictionary.total_size();

    } else {

      const size_t size_per_chunk_in_words = _free_chunks[index].size();

      word_size = size_per_chunk_in_words * num_free_chunks(index);

    }

    return word_size * BytesPerWord;

  }

  MetaspaceChunkFreeListSummary chunk_free_list_summary() const {

    return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),

                                         num_free_chunks(SmallIndex),

                                         num_free_chunks(MediumIndex),

                                         num_free_chunks(HumongousIndex),

                                         size_free_chunks_in_bytes(SpecializedIndex),

                                         size_free_chunks_in_bytes(SmallIndex),

                                         size_free_chunks_in_bytes(MediumIndex),

                                         size_free_chunks_in_bytes(HumongousIndex));

  }

  // Debug support

  void verify();

  void slow_verify() {

    if (VerifyMetaspace) {

      verify();

    }

  }

  void locked_verify();

  void slow_locked_verify() {

    if (VerifyMetaspace) {

      locked_verify();

    }

  }

  void locked_print_free_chunks(outputStream* st);

  void locked_print_sum_free_chunks(outputStream* st);

  // Fill in current statistic values to the given statistics object.

  void collect_statistics(ChunkManagerStatistics* out) const;

};

} // namespace metaspace