1 /*

     2  * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef SHARE_GC_CMS_ADAPTIVEFREELIST_HPP

    26 #define SHARE_GC_CMS_ADAPTIVEFREELIST_HPP

    27 

    28 #include "gc/cms/allocationStats.hpp"

    29 #include "memory/freeList.hpp"

    30 

    31 class CompactibleFreeListSpace;

    32 

    33 // A class for maintaining a free list of Chunk's.  The FreeList

    34 // maintains a the structure of the list (head, tail, etc.) plus

    35 // statistics for allocations from the list.  The links between items

    36 // are not part of FreeList.  The statistics are

    37 // used to make decisions about coalescing Chunk's when they

    38 // are swept during collection.

    39 //

    40 // See the corresponding .cpp file for a description of the specifics

    41 // for that implementation.

    42 

    43 class Mutex;

    44 

    45 template <class Chunk>

    46 class AdaptiveFreeList : public FreeList<Chunk> {

    47   friend class CompactibleFreeListSpace;

    48   friend class VMStructs;

    49   // friend class PrintTreeCensusClosure<Chunk, FreeList_t>;

    50 

    51   size_t        _hint;          // next larger size list with a positive surplus

    52 

    53   AllocationStats _allocation_stats; // allocation-related statistics

    54 

    55  public:

    56 

    57   AdaptiveFreeList();

    58 

    59   using FreeList<Chunk>::assert_proper_lock_protection;

    60 #ifdef ASSERT

    61   using FreeList<Chunk>::protecting_lock;

    62 #endif

    63   using FreeList<Chunk>::count;

    64   using FreeList<Chunk>::size;

    65   using FreeList<Chunk>::verify_chunk_in_free_list;

    66   using FreeList<Chunk>::getFirstNChunksFromList;

    67   using FreeList<Chunk>::print_on;

    68   void return_chunk_at_head(Chunk* fc, bool record_return);

    69   void return_chunk_at_head(Chunk* fc);

    70   void return_chunk_at_tail(Chunk* fc, bool record_return);

    71   void return_chunk_at_tail(Chunk* fc);

    72   using FreeList<Chunk>::return_chunk_at_tail;

    73   using FreeList<Chunk>::remove_chunk;

    74   using FreeList<Chunk>::prepend;

    75   using FreeList<Chunk>::print_labels_on;

    76   using FreeList<Chunk>::get_chunk_at_head;

    77 

    78   // Initialize.

    79   void initialize();

    80 

    81   // Reset the head, tail, hint, and count of a free list.

    82   void reset(size_t hint);

    83 

    84   void print_on(outputStream* st, const char* c = NULL) const;

    85 

    86   size_t hint() const {

    87     return _hint;

    88   }

    89   void set_hint(size_t v) {

    90     assert_proper_lock_protection();

    91     assert(v == 0 || size() < v, "Bad hint");

    92     _hint = v;

    93   }

    94 

    95   size_t get_better_size();

    96 

    97   // Accessors for statistics

    98   void init_statistics(bool split_birth = false);

    99 

   100   AllocationStats* allocation_stats() {

   101     assert_proper_lock_protection();

   102     return &_allocation_stats;

   103   }

   104 

   105   ssize_t desired() const {

   106     return _allocation_stats.desired();

   107   }

   108   void set_desired(ssize_t v) {

   109     assert_proper_lock_protection();

   110     _allocation_stats.set_desired(v);

   111   }

   112   void compute_desired(float inter_sweep_current,

   113                        float inter_sweep_estimate,

   114                        float intra_sweep_estimate) {

   115     assert_proper_lock_protection();

   116     _allocation_stats.compute_desired(count(),

   117                                       inter_sweep_current,

   118                                       inter_sweep_estimate,

   119                                       intra_sweep_estimate);

   120   }

   121   ssize_t coal_desired() const {

   122     return _allocation_stats.coal_desired();

   123   }

   124   void set_coal_desired(ssize_t v) {

   125     assert_proper_lock_protection();

   126     _allocation_stats.set_coal_desired(v);

   127   }

   128 

   129   ssize_t surplus() const {

   130     return _allocation_stats.surplus();

   131   }

   132   void set_surplus(ssize_t v) {

   133     assert_proper_lock_protection();

   134     _allocation_stats.set_surplus(v);

   135   }

   136   void increment_surplus() {

   137     assert_proper_lock_protection();

   138     _allocation_stats.increment_surplus();

   139   }

   140   void decrement_surplus() {

   141     assert_proper_lock_protection();

   142     _allocation_stats.decrement_surplus();

   143   }

   144 

   145   ssize_t bfr_surp() const {

   146     return _allocation_stats.bfr_surp();

   147   }

   148   void set_bfr_surp(ssize_t v) {

   149     assert_proper_lock_protection();

   150     _allocation_stats.set_bfr_surp(v);

   151   }

   152   ssize_t prev_sweep() const {

   153     return _allocation_stats.prev_sweep();

   154   }

   155   void set_prev_sweep(ssize_t v) {

   156     assert_proper_lock_protection();

   157     _allocation_stats.set_prev_sweep(v);

   158   }

   159   ssize_t before_sweep() const {

   160     return _allocation_stats.before_sweep();

   161   }

   162   void set_before_sweep(ssize_t v) {

   163     assert_proper_lock_protection();

   164     _allocation_stats.set_before_sweep(v);

   165   }

   166 

   167   ssize_t coal_births() const {

   168     return _allocation_stats.coal_births();

   169   }

   170   void set_coal_births(ssize_t v) {

   171     assert_proper_lock_protection();

   172     _allocation_stats.set_coal_births(v);

   173   }

   174   void increment_coal_births() {

   175     assert_proper_lock_protection();

   176     _allocation_stats.increment_coal_births();

   177   }

   178 

   179   ssize_t coal_deaths() const {

   180     return _allocation_stats.coal_deaths();

   181   }

   182   void set_coal_deaths(ssize_t v) {

   183     assert_proper_lock_protection();

   184     _allocation_stats.set_coal_deaths(v);

   185   }

   186   void increment_coal_deaths() {

   187     assert_proper_lock_protection();

   188     _allocation_stats.increment_coal_deaths();

   189   }

   190 

   191   ssize_t split_births() const {

   192     return _allocation_stats.split_births();

   193   }

   194   void set_split_births(ssize_t v) {

   195     assert_proper_lock_protection();

   196     _allocation_stats.set_split_births(v);

   197   }

   198   void increment_split_births() {

   199     assert_proper_lock_protection();

   200     _allocation_stats.increment_split_births();

   201   }

   202 

   203   ssize_t split_deaths() const {

   204     return _allocation_stats.split_deaths();

   205   }

   206   void set_split_deaths(ssize_t v) {

   207     assert_proper_lock_protection();

   208     _allocation_stats.set_split_deaths(v);

   209   }

   210   void increment_split_deaths() {

   211     assert_proper_lock_protection();

   212     _allocation_stats.increment_split_deaths();

   213   }

   214 

   215 #ifndef PRODUCT

   216   // For debugging.  The "_returned_bytes" in all the lists are summed

   217   // and compared with the total number of bytes swept during a

   218   // collection.

   219   size_t returned_bytes() const { return _allocation_stats.returned_bytes(); }

   220   void set_returned_bytes(size_t v) { _allocation_stats.set_returned_bytes(v); }

   221   void increment_returned_bytes_by(size_t v) {

   222     _allocation_stats.set_returned_bytes(_allocation_stats.returned_bytes() + v);

   223   }

   224   // Stats verification

   225   void verify_stats() const;

   226 #endif  // NOT PRODUCT

   227 };

   228 

   229 #endif // SHARE_GC_CMS_ADAPTIVEFREELIST_HPP