jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp@3bfae429e2cf

6948537: CMS: BOT walkers observe out-of-thin-air zeros on sun4v sparc/CMT
Summary: On sun4v/CMT avoid use of memset() in BOT updates so as to prevent concurrent BOT readers from seeing the phantom zeros arising from memset()'s use of BIS.
Reviewed-by: jmasa, johnc, minqi, poonam, tonyp

     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@3bfae429e2cf

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