src/share/vm/memory/defNewGeneration.hpp

Print this page
rev 4773 : 8005849: JEP 167: Event-Based JVM Tracing
Reviewed-by: acorn, coleenp, sla
Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>
   1 /*
   2  * Copyright (c) 2001, 2012, 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_MEMORY_DEFNEWGENERATION_HPP
  26 #define SHARE_VM_MEMORY_DEFNEWGENERATION_HPP
  27 
  28 #include "gc_implementation/shared/ageTable.hpp"
  29 #include "gc_implementation/shared/cSpaceCounters.hpp"
  30 #include "gc_implementation/shared/generationCounters.hpp"

  31 #include "memory/generation.inline.hpp"
  32 #include "utilities/stack.hpp"
  33 
  34 class EdenSpace;
  35 class ContiguousSpace;
  36 class ScanClosure;

  37 
  38 // DefNewGeneration is a young generation containing eden, from- and
  39 // to-space.
  40 
  41 class DefNewGeneration: public Generation {
  42   friend class VMStructs;
  43 
  44 protected:
  45   Generation* _next_gen;
  46   uint        _tenuring_threshold;   // Tenuring threshold for next collection.
  47   ageTable    _age_table;
  48   // Size of object to pretenure in words; command line provides bytes
  49   size_t        _pretenure_size_threshold_words;
  50 
  51   ageTable*   age_table() { return &_age_table; }

  52   // Initialize state to optimistically assume no promotion failure will
  53   // happen.
  54   void   init_assuming_no_promotion_failure();
  55   // True iff a promotion has failed in the current collection.
  56   bool   _promotion_failed;
  57   bool   promotion_failed() { return _promotion_failed; }

  58 
  59   // Handling promotion failure.  A young generation collection
  60   // can fail if a live object cannot be copied out of its
  61   // location in eden or from-space during the collection.  If
  62   // a collection fails, the young generation is left in a
  63   // consistent state such that it can be collected by a
  64   // full collection.
  65   //   Before the collection
  66   //     Objects are in eden or from-space
  67   //     All roots into the young generation point into eden or from-space.
  68   //
  69   //   After a failed collection
  70   //     Objects may be in eden, from-space, or to-space
  71   //     An object A in eden or from-space may have a copy B
  72   //       in to-space.  If B exists, all roots that once pointed
  73   //       to A must now point to B.
  74   //     All objects in the young generation are unmarked.
  75   //     Eden, from-space, and to-space will all be collected by
  76   //       the full collection.
  77   void handle_promotion_failure(oop);


 115   // Allocation support
 116   bool _should_allocate_from_space;
 117   bool should_allocate_from_space() const {
 118     return _should_allocate_from_space;
 119   }
 120   void clear_should_allocate_from_space() {
 121     _should_allocate_from_space = false;
 122   }
 123   void set_should_allocate_from_space() {
 124     _should_allocate_from_space = true;
 125   }
 126 
 127   // Tenuring
 128   void adjust_desired_tenuring_threshold();
 129 
 130   // Spaces
 131   EdenSpace*       _eden_space;
 132   ContiguousSpace* _from_space;
 133   ContiguousSpace* _to_space;
 134 


 135   enum SomeProtectedConstants {
 136     // Generations are GenGrain-aligned and have size that are multiples of
 137     // GenGrain.
 138     MinFreeScratchWords = 100
 139   };
 140 
 141   // Return the size of a survivor space if this generation were of size
 142   // gen_size.
 143   size_t compute_survivor_size(size_t gen_size, size_t alignment) const {
 144     size_t n = gen_size / (SurvivorRatio + 2);
 145     return n > alignment ? align_size_down(n, alignment) : alignment;
 146   }
 147 
 148  public:  // was "protected" but caused compile error on win32
 149   class IsAliveClosure: public BoolObjectClosure {
 150     Generation* _g;
 151   public:
 152     IsAliveClosure(Generation* g);
 153     bool do_object_b(oop p);
 154   };


 186   };
 187 
 188   class FastEvacuateFollowersClosure: public VoidClosure {
 189     GenCollectedHeap* _gch;
 190     int _level;
 191     DefNewGeneration* _gen;
 192     FastScanClosure* _scan_cur_or_nonheap;
 193     FastScanClosure* _scan_older;
 194   public:
 195     FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level,
 196                                  DefNewGeneration* gen,
 197                                  FastScanClosure* cur,
 198                                  FastScanClosure* older);
 199     void do_void();
 200   };
 201 
 202  public:
 203   DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
 204                    const char* policy="Copy");
 205 


 206   virtual Generation::Name kind() { return Generation::DefNew; }
 207 
 208   // Accessing spaces
 209   EdenSpace*       eden() const           { return _eden_space; }
 210   ContiguousSpace* from() const           { return _from_space;  }
 211   ContiguousSpace* to()   const           { return _to_space;    }
 212 
 213   virtual CompactibleSpace* first_compaction_space() const;
 214 
 215   // Space enquiries
 216   size_t capacity() const;
 217   size_t used() const;
 218   size_t free() const;
 219   size_t max_capacity() const;
 220   size_t capacity_before_gc() const;
 221   size_t unsafe_max_alloc_nogc() const;
 222   size_t contiguous_available() const;
 223 
 224   size_t max_eden_size() const              { return _max_eden_size; }
 225   size_t max_survivor_size() const          { return _max_survivor_size; }


   1 /*
   2  * Copyright (c) 2001, 2013, 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_MEMORY_DEFNEWGENERATION_HPP
  26 #define SHARE_VM_MEMORY_DEFNEWGENERATION_HPP
  27 
  28 #include "gc_implementation/shared/ageTable.hpp"
  29 #include "gc_implementation/shared/cSpaceCounters.hpp"
  30 #include "gc_implementation/shared/generationCounters.hpp"
  31 #include "gc_implementation/shared/copyFailedInfo.hpp"
  32 #include "memory/generation.inline.hpp"
  33 #include "utilities/stack.hpp"
  34 
  35 class EdenSpace;
  36 class ContiguousSpace;
  37 class ScanClosure;
  38 class STWGCTimer;
  39 
  40 // DefNewGeneration is a young generation containing eden, from- and
  41 // to-space.
  42 
  43 class DefNewGeneration: public Generation {
  44   friend class VMStructs;
  45 
  46 protected:
  47   Generation* _next_gen;
  48   uint        _tenuring_threshold;   // Tenuring threshold for next collection.
  49   ageTable    _age_table;
  50   // Size of object to pretenure in words; command line provides bytes
  51   size_t      _pretenure_size_threshold_words;
  52 
  53   ageTable*   age_table() { return &_age_table; }
  54 
  55   // Initialize state to optimistically assume no promotion failure will
  56   // happen.
  57   void   init_assuming_no_promotion_failure();
  58   // True iff a promotion has failed in the current collection.
  59   bool   _promotion_failed;
  60   bool   promotion_failed() { return _promotion_failed; }
  61   PromotionFailedInfo _promotion_failed_info;
  62 
  63   // Handling promotion failure.  A young generation collection
  64   // can fail if a live object cannot be copied out of its
  65   // location in eden or from-space during the collection.  If
  66   // a collection fails, the young generation is left in a
  67   // consistent state such that it can be collected by a
  68   // full collection.
  69   //   Before the collection
  70   //     Objects are in eden or from-space
  71   //     All roots into the young generation point into eden or from-space.
  72   //
  73   //   After a failed collection
  74   //     Objects may be in eden, from-space, or to-space
  75   //     An object A in eden or from-space may have a copy B
  76   //       in to-space.  If B exists, all roots that once pointed
  77   //       to A must now point to B.
  78   //     All objects in the young generation are unmarked.
  79   //     Eden, from-space, and to-space will all be collected by
  80   //       the full collection.
  81   void handle_promotion_failure(oop);


 119   // Allocation support
 120   bool _should_allocate_from_space;
 121   bool should_allocate_from_space() const {
 122     return _should_allocate_from_space;
 123   }
 124   void clear_should_allocate_from_space() {
 125     _should_allocate_from_space = false;
 126   }
 127   void set_should_allocate_from_space() {
 128     _should_allocate_from_space = true;
 129   }
 130 
 131   // Tenuring
 132   void adjust_desired_tenuring_threshold();
 133 
 134   // Spaces
 135   EdenSpace*       _eden_space;
 136   ContiguousSpace* _from_space;
 137   ContiguousSpace* _to_space;
 138 
 139   STWGCTimer* _gc_timer;
 140 
 141   enum SomeProtectedConstants {
 142     // Generations are GenGrain-aligned and have size that are multiples of
 143     // GenGrain.
 144     MinFreeScratchWords = 100
 145   };
 146 
 147   // Return the size of a survivor space if this generation were of size
 148   // gen_size.
 149   size_t compute_survivor_size(size_t gen_size, size_t alignment) const {
 150     size_t n = gen_size / (SurvivorRatio + 2);
 151     return n > alignment ? align_size_down(n, alignment) : alignment;
 152   }
 153 
 154  public:  // was "protected" but caused compile error on win32
 155   class IsAliveClosure: public BoolObjectClosure {
 156     Generation* _g;
 157   public:
 158     IsAliveClosure(Generation* g);
 159     bool do_object_b(oop p);
 160   };


 192   };
 193 
 194   class FastEvacuateFollowersClosure: public VoidClosure {
 195     GenCollectedHeap* _gch;
 196     int _level;
 197     DefNewGeneration* _gen;
 198     FastScanClosure* _scan_cur_or_nonheap;
 199     FastScanClosure* _scan_older;
 200   public:
 201     FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level,
 202                                  DefNewGeneration* gen,
 203                                  FastScanClosure* cur,
 204                                  FastScanClosure* older);
 205     void do_void();
 206   };
 207 
 208  public:
 209   DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
 210                    const char* policy="Copy");
 211 
 212   virtual void ref_processor_init();
 213 
 214   virtual Generation::Name kind() { return Generation::DefNew; }
 215 
 216   // Accessing spaces
 217   EdenSpace*       eden() const           { return _eden_space; }
 218   ContiguousSpace* from() const           { return _from_space;  }
 219   ContiguousSpace* to()   const           { return _to_space;    }
 220 
 221   virtual CompactibleSpace* first_compaction_space() const;
 222 
 223   // Space enquiries
 224   size_t capacity() const;
 225   size_t used() const;
 226   size_t free() const;
 227   size_t max_capacity() const;
 228   size_t capacity_before_gc() const;
 229   size_t unsafe_max_alloc_nogc() const;
 230   size_t contiguous_available() const;
 231 
 232   size_t max_eden_size() const              { return _max_eden_size; }
 233   size_t max_survivor_size() const          { return _max_survivor_size; }