1 /*

     2  * Copyright (c) 2011, 2017, 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 #ifndef SHARE_VM_MEMORY_METASPACE_HPP

    25 #define SHARE_VM_MEMORY_METASPACE_HPP

    26 

    27 #include "memory/allocation.hpp"

    28 #include "memory/memRegion.hpp"

    29 #include "memory/metaspaceChunkFreeListSummary.hpp"

    30 #include "memory/virtualspace.hpp"

    31 #include "utilities/exceptions.hpp"

    32 

    33 // Metaspace

    34 //

    35 // Metaspaces are Arenas for the VM's metadata.

    36 // They are allocated one per class loader object, and one for the null

    37 // bootstrap class loader

    38 //

    39 //    block X ---+       +-------------------+

    40 //               |       |  Virtualspace     |

    41 //               |       |                   |

    42 //               |       |                   |

    43 //               |       |-------------------|

    44 //               |       || Chunk            |

    45 //               |       ||                  |

    46 //               |       ||----------        |

    47 //               +------>||| block 0 |       |

    48 //                       ||----------        |

    49 //                       ||| block 1 |       |

    50 //                       ||----------        |

    51 //                       ||                  |

    52 //                       |-------------------|

    53 //                       |                   |

    54 //                       |                   |

    55 //                       +-------------------+

    56 //

    57 

    58 class ChunkManager;

    59 class ClassLoaderData;

    60 class Metablock;

    61 class Metachunk;

    62 class MetaspaceTracer;

    63 class MetaWord;

    64 class Mutex;

    65 class outputStream;

    66 class SpaceManager;

    67 class VirtualSpaceList;

    68 

    69 // Metaspaces each have a  SpaceManager and allocations

    70 // are done by the SpaceManager.  Allocations are done

    71 // out of the current Metachunk.  When the current Metachunk

    72 // is exhausted, the SpaceManager gets a new one from

    73 // the current VirtualSpace.  When the VirtualSpace is exhausted

    74 // the SpaceManager gets a new one.  The SpaceManager

    75 // also manages freelists of available Chunks.

    76 //

    77 // Currently the space manager maintains the list of

    78 // virtual spaces and the list of chunks in use.  Its

    79 // allocate() method returns a block for use as a

    80 // quantum of metadata.

    81 

    82 class Metaspace : public CHeapObj<mtClass> {

    83   friend class VMStructs;

    84   friend class SpaceManager;

    85   friend class VM_CollectForMetadataAllocation;

    86   friend class MetaspaceGC;

    87   friend class MetaspaceAux;

    88   friend class MetaspaceShared;

    89   friend class CollectorPolicy;

    90 

    91  public:

    92   enum MetadataType {

    93     ClassType,

    94     NonClassType,

    95     MetadataTypeCount

    96   };

    97   enum MetaspaceType {

    98     StandardMetaspaceType,

    99     BootMetaspaceType,

   100     AnonymousMetaspaceType,

   101     ReflectionMetaspaceType

   102   };

   103 

   104  private:

   105   static void verify_global_initialization();

   106 

   107   void initialize(Mutex* lock, MetaspaceType type);

   108 

   109   // Initialize the first chunk for a Metaspace.  Used for

   110   // special cases such as the boot class loader, reflection

   111   // class loader and anonymous class loader.

   112   void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);

   113   Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);

   114 

   115   // Align up the word size to the allocation word size

   116   static size_t align_word_size_up(size_t);

   117 

   118   // Aligned size of the metaspace.

   119   static size_t _compressed_class_space_size;

   120 

   121   static size_t compressed_class_space_size() {

   122     return _compressed_class_space_size;

   123   }

   124 

   125   static void set_compressed_class_space_size(size_t size) {

   126     _compressed_class_space_size = size;

   127   }

   128 

   129   static size_t _first_chunk_word_size;

   130   static size_t _first_class_chunk_word_size;

   131 

   132   static size_t _commit_alignment;

   133   static size_t _reserve_alignment;

   134   DEBUG_ONLY(static bool   _frozen;)

   135 

   136   SpaceManager* _vsm;

   137   SpaceManager* vsm() const { return _vsm; }

   138 

   139   SpaceManager* _class_vsm;

   140   SpaceManager* class_vsm() const { return _class_vsm; }

   141   SpaceManager* get_space_manager(MetadataType mdtype) {

   142     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");

   143     return mdtype == ClassType ? class_vsm() : vsm();

   144   }

   145 

   146   // Allocate space for metadata of type mdtype. This is space

   147   // within a Metachunk and is used by

   148   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)

   149   MetaWord* allocate(size_t word_size, MetadataType mdtype);

   150 

   151   MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);

   152 

   153   // Virtual Space lists for both classes and other metadata

   154   static VirtualSpaceList* _space_list;

   155   static VirtualSpaceList* _class_space_list;

   156 

   157   static ChunkManager* _chunk_manager_metadata;

   158   static ChunkManager* _chunk_manager_class;

   159 

   160   static const MetaspaceTracer* _tracer;

   161 

   162  public:

   163   static VirtualSpaceList* space_list()       { return _space_list; }

   164   static VirtualSpaceList* class_space_list() { return _class_space_list; }

   165   static VirtualSpaceList* get_space_list(MetadataType mdtype) {

   166     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");

   167     return mdtype == ClassType ? class_space_list() : space_list();

   168   }

   169 

   170   static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }

   171   static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }

   172   static ChunkManager* get_chunk_manager(MetadataType mdtype) {

   173     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");

   174     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();

   175   }

   176 

   177   static const MetaspaceTracer* tracer() { return _tracer; }

   178   static void freeze() {

   179     assert(DumpSharedSpaces, "sanity");

   180     DEBUG_ONLY(_frozen = true;)

   181   }

   182  private:

   183 

   184 #ifdef _LP64

   185   static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);

   186 

   187   // Returns true if can use CDS with metaspace allocated as specified address.

   188   static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);

   189 

   190   static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);

   191 

   192   static void initialize_class_space(ReservedSpace rs);

   193 #endif

   194   size_t class_chunk_size(size_t word_size);

   195 

   196  public:

   197 

   198   Metaspace(Mutex* lock, MetaspaceType type);

   199   ~Metaspace();

   200 

   201   static void ergo_initialize();

   202   static void global_initialize();

   203   static void post_initialize();

   204 

   205   static size_t first_chunk_word_size() { return _first_chunk_word_size; }

   206   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }

   207 

   208   static size_t reserve_alignment()       { return _reserve_alignment; }

   209   static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }

   210   static size_t commit_alignment()        { return _commit_alignment; }

   211   static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }

   212 

   213   size_t used_words_slow(MetadataType mdtype) const;

   214   size_t free_words_slow(MetadataType mdtype) const;

   215   size_t capacity_words_slow(MetadataType mdtype) const;

   216 

   217   size_t used_bytes_slow(MetadataType mdtype) const;

   218   size_t capacity_bytes_slow(MetadataType mdtype) const;

   219 

   220   size_t allocated_blocks_bytes() const;

   221   size_t allocated_chunks_bytes() const;

   222 

   223   static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,

   224                             MetaspaceObj::Type type, TRAPS);

   225   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);

   226 

   227   static bool contains(const void* ptr);

   228   static bool contains_non_shared(const void* ptr);

   229 

   230   void dump(outputStream* const out) const;

   231 

   232   // Free empty virtualspaces

   233   static void purge(MetadataType mdtype);

   234   static void purge();

   235 

   236   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,

   237                                    MetaspaceObj::Type type, MetadataType mdtype, TRAPS);

   238 

   239   static const char* metadata_type_name(Metaspace::MetadataType mdtype);

   240 

   241   void print_on(outputStream* st) const;

   242   // Debugging support

   243   void verify();

   244 

   245   static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});

   246 

   247   // Return TRUE only if UseCompressedClassPointers is True.

   248   static bool using_class_space() {

   249     return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);

   250   }

   251 

   252   static bool is_class_space_allocation(MetadataType mdType) {

   253     return mdType == ClassType && using_class_space();

   254   }

   255 

   256 };

   257 

   258 class MetaspaceAux : AllStatic {

   259   static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);

   260 

   261   // These methods iterate over the classloader data graph

   262   // for the given Metaspace type.  These are slow.

   263   static size_t used_bytes_slow(Metaspace::MetadataType mdtype);

   264   static size_t free_bytes_slow(Metaspace::MetadataType mdtype);

   265   static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);

   266   static size_t capacity_bytes_slow();

   267 

   268   // Running sum of space in all Metachunks that has been

   269   // allocated to a Metaspace.  This is used instead of

   270   // iterating over all the classloaders. One for each

   271   // type of Metadata

   272   static size_t _capacity_words[Metaspace:: MetadataTypeCount];

   273   // Running sum of space in all Metachunks that

   274   // are being used for metadata. One for each

   275   // type of Metadata.

   276   static size_t _used_words[Metaspace:: MetadataTypeCount];

   277 

   278  public:

   279   // Decrement and increment _allocated_capacity_words

   280   static void dec_capacity(Metaspace::MetadataType type, size_t words);

   281   static void inc_capacity(Metaspace::MetadataType type, size_t words);

   282 

   283   // Decrement and increment _allocated_used_words

   284   static void dec_used(Metaspace::MetadataType type, size_t words);

   285   static void inc_used(Metaspace::MetadataType type, size_t words);

   286 

   287   // Total of space allocated to metadata in all Metaspaces.

   288   // This sums the space used in each Metachunk by

   289   // iterating over the classloader data graph

   290   static size_t used_bytes_slow() {

   291     return used_bytes_slow(Metaspace::ClassType) +

   292            used_bytes_slow(Metaspace::NonClassType);

   293   }

   294 

   295   // Used by MetaspaceCounters

   296   static size_t free_chunks_total_words();

   297   static size_t free_chunks_total_bytes();

   298   static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);

   299 

   300   static size_t capacity_words(Metaspace::MetadataType mdtype) {

   301     return _capacity_words[mdtype];

   302   }

   303   static size_t capacity_words() {

   304     return capacity_words(Metaspace::NonClassType) +

   305            capacity_words(Metaspace::ClassType);

   306   }

   307   static size_t capacity_bytes(Metaspace::MetadataType mdtype) {

   308     return capacity_words(mdtype) * BytesPerWord;

   309   }

   310   static size_t capacity_bytes() {

   311     return capacity_words() * BytesPerWord;

   312   }

   313 

   314   static size_t used_words(Metaspace::MetadataType mdtype) {

   315     return _used_words[mdtype];

   316   }

   317   static size_t used_words() {

   318     return used_words(Metaspace::NonClassType) +

   319            used_words(Metaspace::ClassType);

   320   }

   321   static size_t used_bytes(Metaspace::MetadataType mdtype) {

   322     return used_words(mdtype) * BytesPerWord;

   323   }

   324   static size_t used_bytes() {

   325     return used_words() * BytesPerWord;

   326   }

   327 

   328   static size_t free_bytes();

   329   static size_t free_bytes(Metaspace::MetadataType mdtype);

   330 

   331   static size_t reserved_bytes(Metaspace::MetadataType mdtype);

   332   static size_t reserved_bytes() {

   333     return reserved_bytes(Metaspace::ClassType) +

   334            reserved_bytes(Metaspace::NonClassType);

   335   }

   336 

   337   static size_t committed_bytes(Metaspace::MetadataType mdtype);

   338   static size_t committed_bytes() {

   339     return committed_bytes(Metaspace::ClassType) +

   340            committed_bytes(Metaspace::NonClassType);

   341   }

   342 

   343   static size_t min_chunk_size_words();

   344   static size_t min_chunk_size_bytes() {

   345     return min_chunk_size_words() * BytesPerWord;

   346   }

   347 

   348   static bool has_chunk_free_list(Metaspace::MetadataType mdtype);

   349   static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);

   350 

   351   // Print change in used metadata.

   352   static void print_metaspace_change(size_t prev_metadata_used);

   353   static void print_on(outputStream * out);

   354   static void print_on(outputStream * out, Metaspace::MetadataType mdtype);

   355 

   356   static void print_class_waste(outputStream* out);

   357   static void print_waste(outputStream* out);

   358   static void dump(outputStream* out);

   359   static void verify_free_chunks();

   360   // Checks that the values returned by allocated_capacity_bytes() and

   361   // capacity_bytes_slow() are the same.

   362   static void verify_capacity();

   363   static void verify_used();

   364   static void verify_metrics();

   365 };

   366 

   367 // Metaspace are deallocated when their class loader are GC'ed.

   368 // This class implements a policy for inducing GC's to recover

   369 // Metaspaces.

   370 

   371 class MetaspaceGC : AllStatic {

   372 

   373   // The current high-water-mark for inducing a GC.

   374   // When committed memory of all metaspaces reaches this value,

   375   // a GC is induced and the value is increased. Size is in bytes.

   376   static volatile intptr_t _capacity_until_GC;

   377 

   378   // For a CMS collection, signal that a concurrent collection should

   379   // be started.

   380   static bool _should_concurrent_collect;

   381 

   382   static uint _shrink_factor;

   383 

   384   static size_t shrink_factor() { return _shrink_factor; }

   385   void set_shrink_factor(uint v) { _shrink_factor = v; }

   386 

   387  public:

   388 

   389   static void initialize();

   390   static void post_initialize();

   391 

   392   static size_t capacity_until_GC();

   393   static bool inc_capacity_until_GC(size_t v,

   394                                     size_t* new_cap_until_GC = NULL,

   395                                     size_t* old_cap_until_GC = NULL);

   396   static size_t dec_capacity_until_GC(size_t v);

   397 

   398   static bool should_concurrent_collect() { return _should_concurrent_collect; }

   399   static void set_should_concurrent_collect(bool v) {

   400     _should_concurrent_collect = v;

   401   }

   402 

   403   // The amount to increase the high-water-mark (_capacity_until_GC)

   404   static size_t delta_capacity_until_GC(size_t bytes);

   405 

   406   // Tells if we have can expand metaspace without hitting set limits.

   407   static bool can_expand(size_t words, bool is_class);

   408 

   409   // Returns amount that we can expand without hitting a GC,

   410   // measured in words.

   411   static size_t allowed_expansion();

   412 

   413   // Calculate the new high-water mark at which to induce

   414   // a GC.

   415   static void compute_new_size();

   416 };

   417 

   418 #endif // SHARE_VM_MEMORY_METASPACE_HPP