text: /*
   * Copyright (c) 2001, 2015, 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_VM_GC_CMS_ADAPTIVEFREELIST_HPP
  #define SHARE_VM_GC_CMS_ADAPTIVEFREELIST_HPP
  
  #include "gc/cms/allocationStats.hpp"
  #include "memory/freeList.hpp"
  
  class CompactibleFreeListSpace;
  
  // A class for maintaining a free list of Chunk's.  The FreeList
  // maintains a the structure of the list (head, tail, etc.) plus
  // statistics for allocations from the list.  The links between items
  // are not part of FreeList.  The statistics are
  // used to make decisions about coalescing Chunk's when they
  // are swept during collection.
  //
  // See the corresponding .cpp file for a description of the specifics
  // for that implementation.
  
  class Mutex;
  
  template <class Chunk>
  class AdaptiveFreeList : public FreeList<Chunk> {
    friend class CompactibleFreeListSpace;
    friend class VMStructs;
    // friend class PrintTreeCensusClosure<Chunk, FreeList_t>;
  
    size_t        _hint;          // next larger size list with a positive surplus
  
    AllocationStats _allocation_stats; // allocation-related statistics
  
   public:
  
    AdaptiveFreeList();
  
    using FreeList<Chunk>::assert_proper_lock_protection;
  #ifdef ASSERT
    using FreeList<Chunk>::protecting_lock;
  #endif
    using FreeList<Chunk>::count;
    using FreeList<Chunk>::size;
    using FreeList<Chunk>::verify_chunk_in_free_list;
    using FreeList<Chunk>::getFirstNChunksFromList;
    using FreeList<Chunk>::print_on;
    void return_chunk_at_head(Chunk* fc, bool record_return);
    void return_chunk_at_head(Chunk* fc);
    void return_chunk_at_tail(Chunk* fc, bool record_return);
    void return_chunk_at_tail(Chunk* fc);
    using FreeList<Chunk>::return_chunk_at_tail;
    using FreeList<Chunk>::remove_chunk;
    using FreeList<Chunk>::prepend;
    using FreeList<Chunk>::print_labels_on;
    using FreeList<Chunk>::get_chunk_at_head;
  
    // Initialize.
    void initialize();
  
    // Reset the head, tail, hint, and count of a free list.
    void reset(size_t hint);
  
    void print_on(outputStream* st, const char* c = NULL) const;
  
    size_t hint() const {
      return _hint;
    }
    void set_hint(size_t v) {
      assert_proper_lock_protection();
      assert(v == 0 || size() < v, "Bad hint");
      _hint = v;
    }
  
    size_t get_better_size();
  
    // Accessors for statistics
    void init_statistics(bool split_birth = false);
  
    AllocationStats* allocation_stats() {
      assert_proper_lock_protection();
      return &_allocation_stats;
    }
  
    ssize_t desired() const {
      return _allocation_stats.desired();
    }
    void set_desired(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_desired(v);
    }
    void compute_desired(float inter_sweep_current,
                         float inter_sweep_estimate,
                         float intra_sweep_estimate) {
      assert_proper_lock_protection();
      _allocation_stats.compute_desired(count(),
                                        inter_sweep_current,
                                        inter_sweep_estimate,
                                        intra_sweep_estimate);
    }
    ssize_t coal_desired() const {
      return _allocation_stats.coal_desired();
    }
    void set_coal_desired(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_coal_desired(v);
    }
  
    ssize_t surplus() const {
      return _allocation_stats.surplus();
    }
    void set_surplus(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_surplus(v);
    }
    void increment_surplus() {
      assert_proper_lock_protection();
      _allocation_stats.increment_surplus();
    }
    void decrement_surplus() {
      assert_proper_lock_protection();
      _allocation_stats.decrement_surplus();
    }
  
    ssize_t bfr_surp() const {
      return _allocation_stats.bfr_surp();
    }
    void set_bfr_surp(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_bfr_surp(v);
    }
    ssize_t prev_sweep() const {
      return _allocation_stats.prev_sweep();
    }
    void set_prev_sweep(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_prev_sweep(v);
    }
    ssize_t before_sweep() const {
      return _allocation_stats.before_sweep();
    }
    void set_before_sweep(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_before_sweep(v);
    }
  
    ssize_t coal_births() const {
      return _allocation_stats.coal_births();
    }
    void set_coal_births(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_coal_births(v);
    }
    void increment_coal_births() {
      assert_proper_lock_protection();
      _allocation_stats.increment_coal_births();
    }
  
    ssize_t coal_deaths() const {
      return _allocation_stats.coal_deaths();
    }
    void set_coal_deaths(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_coal_deaths(v);
    }
    void increment_coal_deaths() {
      assert_proper_lock_protection();
      _allocation_stats.increment_coal_deaths();
    }
  
    ssize_t split_births() const {
      return _allocation_stats.split_births();
    }
    void set_split_births(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_split_births(v);
    }
    void increment_split_births() {
      assert_proper_lock_protection();
      _allocation_stats.increment_split_births();
    }
  
    ssize_t split_deaths() const {
      return _allocation_stats.split_deaths();
    }
    void set_split_deaths(ssize_t v) {
      assert_proper_lock_protection();
      _allocation_stats.set_split_deaths(v);
    }
    void increment_split_deaths() {
      assert_proper_lock_protection();
      _allocation_stats.increment_split_deaths();
    }
  
  #ifndef PRODUCT
    // For debugging.  The "_returned_bytes" in all the lists are summed
    // and compared with the total number of bytes swept during a
    // collection.
    size_t returned_bytes() const { return _allocation_stats.returned_bytes(); }
    void set_returned_bytes(size_t v) { _allocation_stats.set_returned_bytes(v); }
    void increment_returned_bytes_by(size_t v) {
      _allocation_stats.set_returned_bytes(_allocation_stats.returned_bytes() + v);
    }
    // Stats verification
    void verify_stats() const;
  #endif  // NOT PRODUCT
  };
  
  #endif // SHARE_VM_GC_CMS_ADAPTIVEFREELIST_HPP
  