jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp@e018e6884bd8

6631166: CMS: better heuristics when combatting fragmentation
Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa

     1 /*

     2  * Copyright 2001-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    25 // A FreeBlockDictionary is an abstract superclass that will allow

    26 // a number of alternative implementations in the future.

    27 class FreeBlockDictionary: public CHeapObj {

    28  public:

    29   enum Dither {

    30     atLeast,

    31     exactly,

    32     roughly

    33   };

    34   enum DictionaryChoice {

    35     dictionaryBinaryTree = 0,

    36     dictionarySplayTree  = 1,

    37     dictionarySkipList   = 2

    38   };

    40  private:

    41   NOT_PRODUCT(Mutex* _lock;)

    43  public:

    44   virtual void       removeChunk(FreeChunk* fc) = 0;

    45   virtual FreeChunk* getChunk(size_t size, Dither dither = atLeast) = 0;

    46   virtual void       returnChunk(FreeChunk* chunk) = 0;

    47   virtual size_t     totalChunkSize(debug_only(const Mutex* lock)) const = 0;

    48   virtual size_t     maxChunkSize()   const = 0;

    49   virtual size_t     minSize()        const = 0;

    50   // Reset the dictionary to the initial conditions for a single

    51   // block.

    52   virtual void       reset(HeapWord* addr, size_t size) = 0;

    53   virtual void       reset() = 0;

    55   virtual void       dictCensusUpdate(size_t size, bool split, bool birth) = 0;

    56   virtual bool       coalDictOverPopulated(size_t size) = 0;

    57   virtual void       beginSweepDictCensus(double coalSurplusPercent,

    58                        float inter_sweep_current, float inter_sweep_estimate,

    59                        float intra__sweep_current) = 0;

    60   virtual void       endSweepDictCensus(double splitSurplusPercent) = 0;

    61   virtual FreeChunk* findLargestDict() const = 0;

    62   // verify that the given chunk is in the dictionary.

    63   virtual bool verifyChunkInFreeLists(FreeChunk* tc) const = 0;

    65   // Sigma_{all_free_blocks} (block_size^2)

    66   virtual double sum_of_squared_block_sizes() const = 0;

    68   virtual FreeChunk* find_chunk_ends_at(HeapWord* target) const = 0;

    69   virtual void inc_totalSize(size_t v) = 0;

    70   virtual void dec_totalSize(size_t v) = 0;

    72   NOT_PRODUCT (

    73     virtual size_t   sumDictReturnedBytes() = 0;

    74     virtual void     initializeDictReturnedBytes() = 0;

    75     virtual size_t   totalCount() = 0;

    76   )

    78   virtual void       reportStatistics() const {

    79     gclog_or_tty->print("No statistics available");

    80   }

    82   virtual void       printDictCensus() const = 0;

    83   virtual void       print_free_lists(outputStream* st) const = 0;

    85   virtual void       verify()         const = 0;

    87   Mutex* par_lock()                const PRODUCT_RETURN0;

    88   void   set_par_lock(Mutex* lock)       PRODUCT_RETURN;

    89   void   verify_par_locked()       const PRODUCT_RETURN;

    90 };

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp@e018e6884bd8

src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp