1 /*

     2  * Copyright (c) 2005, 2010, 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_VM_GC_IMPLEMENTATION_PARNEW_ASPARNEWGENERATION_HPP

    26 #define SHARE_VM_GC_IMPLEMENTATION_PARNEW_ASPARNEWGENERATION_HPP

    27 

    28 #include "gc_implementation/parNew/parNewGeneration.hpp"

    29 #include "gc_implementation/shared/adaptiveSizePolicy.hpp"

    30 

    31 // A Generation that does parallel young-gen collection extended

    32 // for adaptive size policy.

    33 

    34 // Division of generation into spaces

    35 // done by DefNewGeneration::compute_space_boundaries()

    36 //      +---------------+

    37 //      | uncommitted   |

    38 //      |---------------|

    39 //      | ss0           |

    40 //      |---------------|

    41 //      | ss1           |

    42 //      |---------------|

    43 //      |               |

    44 //      | eden          |

    45 //      |               |

    46 //      +---------------+       <-- low end of VirtualSpace

    47 //

    48 class ASParNewGeneration: public ParNewGeneration {

    49 

    50   size_t _min_gen_size;

    51 

    52   // Resize the generation based on the desired sizes of

    53   // the constituent spaces.

    54   bool resize_generation(size_t eden_size, size_t survivor_size);

    55   // Resize the spaces based on their desired sizes but

    56   // respecting the maximum size of the generation.

    57   void resize_spaces(size_t eden_size, size_t survivor_size);

    58   // Return the byte size remaining to the minimum generation size.

    59   size_t available_to_min_gen();

    60   // Return the byte size remaining to the live data in the generation.

    61   size_t available_to_live() const;

    62   // Return the byte size that the generation is allowed to shrink.

    63   size_t limit_gen_shrink(size_t bytes);

    64   // Reset the size of the spaces after a shrink of the generation.

    65   void reset_survivors_after_shrink();

    66 

    67   // Accessor

    68   VirtualSpace* virtual_space() { return &_virtual_space; }

    69 

    70   virtual void adjust_desired_tenuring_threshold();

    71 

    72  public:

    73 

    74   ASParNewGeneration(ReservedSpace rs,

    75                      size_t initial_byte_size,

    76                      size_t min_byte_size,

    77                      int level);

    78 

    79   virtual const char* short_name() const { return "ASParNew"; }

    80   virtual const char* name() const;

    81   virtual Generation::Name kind() { return ASParNew; }

    82 

    83   // Change the sizes of eden and the survivor spaces in

    84   // the generation.  The parameters are desired sizes

    85   // and are not guaranteed to be met.  For example, if

    86   // the total is larger than the generation.

    87   void resize(size_t eden_size, size_t survivor_size);

    88 

    89   virtual void compute_new_size();

    90 

    91   size_t max_gen_size()                 { return _reserved.byte_size(); }

    92   size_t min_gen_size() const           { return _min_gen_size; }

    93 

    94   // Space boundary invariant checker

    95   void space_invariants() PRODUCT_RETURN;

    96 };

    97 

    98 #endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_ASPARNEWGENERATION_HPP