1 /*

     2  * Copyright (c) 2007 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  */

    24 

    25 class CardTableRS;   // fwd decl

    26 class ConcurrentMarkSweepGeneration;

    27 

    28 // A PermGen implemented with a CMS space, collected by a CMS collector.

    29 class CMSPermGen:  public PermGen {

    30   friend class VMStructs;

    31 

    32   HeapWord* mem_allocate_work(size_t size);

    33  protected:

    34   // The "generation" view.

    35   ConcurrentMarkSweepGeneration* _gen;

    36 

    37  public:

    38   CMSPermGen(ReservedSpace rs, size_t initial_byte_size,

    39              CardTableRS* ct, FreeBlockDictionary::DictionaryChoice);

    40 

    41   HeapWord* mem_allocate(size_t size);

    42 

    43   void compute_new_size();

    44 

    45   Generation* as_gen() const { return _gen; }

    46 };

    47 

    48 // This is the "generation" view of a CMSPermGen.

    49 class CMSPermGenGen: public ConcurrentMarkSweepGeneration {

    50   // Abstractly, this is a subtype that gets access to protected fields.

    51   friend class CMSPermGen;

    52 public:

    53   CMSPermGenGen(ReservedSpace rs, size_t initial_byte_size,

    54                        int level, CardTableRS* ct):

    55     // See comments in the constructor for CompactibleFreeListSpace

    56     // regarding not using adaptive free lists for a perm gen.

    57     ConcurrentMarkSweepGeneration(rs, initial_byte_size, // MinPermHeapExapnsion

    58       level, ct, false /* use adaptive freelists */,

    59       (FreeBlockDictionary::DictionaryChoice)CMSDictionaryChoice)

    60   {}

    61 

    62   void initialize_performance_counters();

    63 

    64   const char* name() const {

    65     return "concurrent-mark-sweep perm gen";

    66   }

    67 

    68   const char* short_name() const {

    69     return "CMS Perm";

    70   }

    71 

    72   bool must_be_youngest() const { return false; }

    73   bool must_be_oldest() const { return false; }

    74 };