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src/hotspot/share/memory/metaspace/metachunk.hpp

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rev 50068 : [mq]: metaspace-split


   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 #ifndef SHARE_VM_MEMORY_METACHUNK_HPP
  25 #define SHARE_VM_MEMORY_METACHUNK_HPP
  26 


  27 #include "utilities/debug.hpp"
  28 #include "utilities/globalDefinitions.hpp"
  29 
  30 class VirtualSpaceNode;
  31 
  32 // Super class of Metablock and Metachunk to allow them to
  33 // be put on the FreeList and in the BinaryTreeDictionary.
  34 template <class T>
  35 class Metabase {
  36   size_t _word_size;
  37   T*     _next;
  38   T*     _prev;
  39 
  40  protected:
  41   Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {}
  42 
  43  public:
  44   T* next() const         { return _next; }
  45   T* prev() const         { return _prev; }
  46   void set_next(T* v)     { _next = v; assert(v != this, "Boom");}
  47   void set_prev(T* v)     { _prev = v; assert(v != this, "Boom");}
  48   void clear_next()       { set_next(NULL); }
  49   void clear_prev()       { set_prev(NULL); }
  50 
  51   size_t size() const volatile { return _word_size; }
  52   void set_size(size_t v) { _word_size = v; }
  53 
  54   void link_next(T* ptr)  { set_next(ptr); }
  55   void link_prev(T* ptr)  { set_prev(ptr); }
  56   void link_after(T* ptr) {
  57     link_next(ptr);
  58     if (ptr != NULL) ptr->link_prev((T*)this);
  59   }
  60 
  61   uintptr_t* end() const        { return ((uintptr_t*) this) + size(); }
  62 
  63   bool cantCoalesce() const     { return false; }
  64 
  65   // Debug support
  66 #ifdef ASSERT
  67   void* prev_addr() const { return (void*)&_prev; }
  68   void* next_addr() const { return (void*)&_next; }
  69   void* size_addr() const { return (void*)&_word_size; }
  70 #endif
  71   bool verify_chunk_in_free_list(T* tc) const { return true; }
  72   bool verify_par_locked() { return true; }
  73 
  74   void assert_is_mangled() const {/* Don't check "\*/}

  75 
  76   bool is_free()                 { return true; }
  77 };
  78 
  79 //  Metachunk - Quantum of allocation from a Virtualspace
  80 //    Metachunks are reused (when freed are put on a global freelist) and
  81 //    have no permanent association to a SpaceManager.
  82 
  83 //            +--------------+ <- end    --+       --+
  84 //            |              |             |         |
  85 //            |              |             | free    |
  86 //            |              |             |         |
  87 //            |              |             |         | size | capacity
  88 //            |              |             |         |
  89 //            |              | <- top   -- +         |
  90 //            |              |             |         |
  91 //            |              |             | used    |
  92 //            |              |             |         |
  93 //            |              |             |         |
  94 //            +--------------+ <- bottom --+       --+
  95 
  96 // ChunkIndex defines the type of chunk.
  97 // Chunk types differ by size: specialized < small < medium, chunks
  98 // larger than medium are humongous chunks of varying size.
  99 enum ChunkIndex {
 100   ZeroIndex = 0,
 101   SpecializedIndex = ZeroIndex,
 102   SmallIndex = SpecializedIndex + 1,
 103   MediumIndex = SmallIndex + 1,
 104   HumongousIndex = MediumIndex + 1,
 105   NumberOfFreeLists = 3,
 106   NumberOfInUseLists = 4
 107 };
 108 
 109 // Utility functions.
 110 size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunk_type, bool is_class);
 111 ChunkIndex get_chunk_type_by_size(size_t size, bool is_class);
 112 
 113 ChunkIndex next_chunk_index(ChunkIndex i);
 114 ChunkIndex prev_chunk_index(ChunkIndex i);
 115 
 116 // Returns a descriptive name for a chunk type.
 117 const char* chunk_size_name(ChunkIndex index);
 118 
 119 // Verify chunk type.
 120 inline bool is_valid_chunktype(ChunkIndex index) {
 121   return index == SpecializedIndex || index == SmallIndex ||
 122          index == MediumIndex || index == HumongousIndex;
 123 }
 124 
 125 inline bool is_valid_nonhumongous_chunktype(ChunkIndex index) {
 126   return is_valid_chunktype(index) && index != HumongousIndex;
 127 }
 128 
 129 enum ChunkOrigin {
 130   // Chunk normally born (via take_from_committed)
 131   origin_normal = 1,
 132   // Chunk was born as padding chunk
 133   origin_pad = 2,
 134   // Chunk was born as leftover chunk in VirtualSpaceNode::retire
 135   origin_leftover = 3,
 136   // Chunk was born as result of a merge of smaller chunks
 137   origin_merge = 4,
 138   // Chunk was born as result of a split of a larger chunk
 139   origin_split = 5,
 140 
 141   origin_minimum = origin_normal,
 142   origin_maximum = origin_split,
 143   origins_count = origin_maximum + 1
 144 };
 145 
 146 inline bool is_valid_chunkorigin(ChunkOrigin origin) {
 147   return origin == origin_normal ||
 148     origin == origin_pad ||
 149     origin == origin_leftover ||
 150     origin == origin_merge ||
 151     origin == origin_split;
 152 }
 153 
 154 class Metachunk : public Metabase<Metachunk> {
 155   friend class MetachunkTest;


 156   // The VirtualSpaceNode containing this chunk.
 157   VirtualSpaceNode* const _container;
 158 
 159   // Current allocation top.
 160   MetaWord* _top;
 161 
 162   // A 32bit sentinel for debugging purposes.
 163   enum { CHUNK_SENTINEL = 0x4d4554EF,  // "MET"
 164          CHUNK_SENTINEL_INVALID = 0xFEEEEEEF
 165   };
 166 
 167   uint32_t _sentinel;
 168 
 169   const ChunkIndex _chunk_type;
 170   const bool _is_class;
 171   // Whether the chunk is free (in freelist) or in use by some class loader.
 172   bool _is_tagged_free;
 173 
 174   ChunkOrigin _origin;
 175   int _use_count;


 215 
 216   void print_on(outputStream* st) const;
 217 
 218   bool is_valid_sentinel() const        { return _sentinel == CHUNK_SENTINEL; }
 219   void remove_sentinel()                { _sentinel = CHUNK_SENTINEL_INVALID; }
 220 
 221   int get_use_count() const             { return _use_count; }
 222   void inc_use_count()                  { _use_count ++; }
 223 
 224   ChunkOrigin get_origin() const        { return _origin; }
 225   void set_origin(ChunkOrigin orig)     { _origin = orig; }
 226 
 227   ChunkIndex get_chunk_type() const     { return _chunk_type; }
 228   bool is_class() const                 { return _is_class; }
 229 
 230   DEBUG_ONLY(void mangle(juint word_value);)
 231   DEBUG_ONLY(void verify() const;)
 232 
 233 };
 234 
 235 // Metablock is the unit of allocation from a Chunk.
 236 //
 237 // A Metablock may be reused by its SpaceManager but are never moved between
 238 // SpaceManagers.  There is no explicit link to the Metachunk
 239 // from which it was allocated.  Metablock may be deallocated and
 240 // put on a freelist but the space is never freed, rather
 241 // the Metachunk it is a part of will be deallocated when it's
 242 // associated class loader is collected.
 243 
 244 class Metablock : public Metabase<Metablock> {
 245   friend class VMStructs;
 246  public:
 247   Metablock(size_t word_size) : Metabase<Metablock>(word_size) {}
 248 };




 249 
 250 #endif  // SHARE_VM_MEMORY_METACHUNK_HPP


   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 #ifndef SHARE_VM_MEMORY_METACHUNK_HPP
  25 #define SHARE_VM_MEMORY_METACHUNK_HPP
  26 
  27 #include "memory/metaspace/metabase.hpp"
  28 #include "memory/metaspace/metaspaceCommon.hpp"
  29 #include "utilities/debug.hpp"
  30 #include "utilities/globalDefinitions.hpp"
  31 
  32 class MetachunkTest;










































  33 
  34 namespace metaspace {
  35 namespace internals {
  36 
  37 class VirtualSpaceNode;

  38 
  39 //  Metachunk - Quantum of allocation from a Virtualspace
  40 //    Metachunks are reused (when freed are put on a global freelist) and
  41 //    have no permanent association to a SpaceManager.
  42 
  43 //            +--------------+ <- end    --+       --+
  44 //            |              |             |         |
  45 //            |              |             | free    |
  46 //            |              |             |         |
  47 //            |              |             |         | size | capacity
  48 //            |              |             |         |
  49 //            |              | <- top   -- +         |
  50 //            |              |             |         |
  51 //            |              |             | used    |
  52 //            |              |             |         |
  53 //            |              |             |         |
  54 //            +--------------+ <- bottom --+       --+
  55 

































  56 enum ChunkOrigin {
  57   // Chunk normally born (via take_from_committed)
  58   origin_normal = 1,
  59   // Chunk was born as padding chunk
  60   origin_pad = 2,
  61   // Chunk was born as leftover chunk in VirtualSpaceNode::retire
  62   origin_leftover = 3,
  63   // Chunk was born as result of a merge of smaller chunks
  64   origin_merge = 4,
  65   // Chunk was born as result of a split of a larger chunk
  66   origin_split = 5,
  67 
  68   origin_minimum = origin_normal,
  69   origin_maximum = origin_split,
  70   origins_count = origin_maximum + 1
  71 };
  72 
  73 inline bool is_valid_chunkorigin(ChunkOrigin origin) {
  74   return origin == origin_normal ||
  75     origin == origin_pad ||
  76     origin == origin_leftover ||
  77     origin == origin_merge ||
  78     origin == origin_split;
  79 }
  80 
  81 class Metachunk : public Metabase<Metachunk> {
  82 
  83   friend class ::MetachunkTest;
  84 
  85   // The VirtualSpaceNode containing this chunk.
  86   VirtualSpaceNode* const _container;
  87 
  88   // Current allocation top.
  89   MetaWord* _top;
  90 
  91   // A 32bit sentinel for debugging purposes.
  92   enum { CHUNK_SENTINEL = 0x4d4554EF,  // "MET"
  93          CHUNK_SENTINEL_INVALID = 0xFEEEEEEF
  94   };
  95 
  96   uint32_t _sentinel;
  97 
  98   const ChunkIndex _chunk_type;
  99   const bool _is_class;
 100   // Whether the chunk is free (in freelist) or in use by some class loader.
 101   bool _is_tagged_free;
 102 
 103   ChunkOrigin _origin;
 104   int _use_count;


 144 
 145   void print_on(outputStream* st) const;
 146 
 147   bool is_valid_sentinel() const        { return _sentinel == CHUNK_SENTINEL; }
 148   void remove_sentinel()                { _sentinel = CHUNK_SENTINEL_INVALID; }
 149 
 150   int get_use_count() const             { return _use_count; }
 151   void inc_use_count()                  { _use_count ++; }
 152 
 153   ChunkOrigin get_origin() const        { return _origin; }
 154   void set_origin(ChunkOrigin orig)     { _origin = orig; }
 155 
 156   ChunkIndex get_chunk_type() const     { return _chunk_type; }
 157   bool is_class() const                 { return _is_class; }
 158 
 159   DEBUG_ONLY(void mangle(juint word_value);)
 160   DEBUG_ONLY(void verify() const;)
 161 
 162 };
 163 








 164 
 165 // Helper function that does a bunch of checks for a chunk.
 166 DEBUG_ONLY(void do_verify_chunk(Metachunk* chunk);)
 167 
 168 // Given a Metachunk, update its in-use information (both in the
 169 // chunk and the occupancy map).
 170 void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse);
 171 
 172 } // namespace metaspace
 173 } // namespace internals
 174 
 175 #endif  // SHARE_VM_MEMORY_METACHUNK_HPP
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