1 /*
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   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
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  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 PrintCLDMetaspaceInfoClosure;
  67 class SpaceManager;
  68 class VirtualSpaceList;
  69 
  70 // Metaspaces each have a  SpaceManager and allocations
  71 // are done by the SpaceManager.  Allocations are done
  72 // out of the current Metachunk.  When the current Metachunk
  73 // is exhausted, the SpaceManager gets a new one from
  74 // the current VirtualSpace.  When the VirtualSpace is exhausted
  75 // the SpaceManager gets a new one.  The SpaceManager
  76 // also manages freelists of available Chunks.
  77 //
  78 // Currently the space manager maintains the list of
  79 // virtual spaces and the list of chunks in use.  Its
  80 // allocate() method returns a block for use as a
  81 // quantum of metadata.
  82 
  83 class Metaspace : public CHeapObj<mtClass> {
  84   friend class VMStructs;
  85   friend class SpaceManager;
  86   friend class VM_CollectForMetadataAllocation;
  87   friend class MetaspaceGC;
  88   friend class MetaspaceAux;
  89   friend class MetaspaceShared;
  90   friend class CollectorPolicy;
  91   friend class PrintCLDMetaspaceInfoClosure;
  92 
  93  public:
  94   enum MetadataType {
  95     ClassType,
  96     NonClassType,
  97     MetadataTypeCount
  98   };
  99   enum MetaspaceType {
 100     StandardMetaspaceType,
 101     BootMetaspaceType,
 102     AnonymousMetaspaceType,
 103     ReflectionMetaspaceType
 104   };
 105 
 106  private:
 107   static void verify_global_initialization();
 108 
 109   void initialize(Mutex* lock, MetaspaceType type);
 110 
 111   // Initialize the first chunk for a Metaspace.  Used for
 112   // special cases such as the boot class loader, reflection
 113   // class loader and anonymous class loader.
 114   void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
 115   Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
 116 
 117   // Align up the word size to the allocation word size
 118   static size_t align_word_size_up(size_t);
 119 
 120   // Aligned size of the metaspace.
 121   static size_t _compressed_class_space_size;
 122 
 123   static size_t compressed_class_space_size() {
 124     return _compressed_class_space_size;
 125   }
 126 
 127   static void set_compressed_class_space_size(size_t size) {
 128     _compressed_class_space_size = size;
 129   }
 130 
 131   static size_t _first_chunk_word_size;
 132   static size_t _first_class_chunk_word_size;
 133 
 134   static size_t _commit_alignment;
 135   static size_t _reserve_alignment;
 136   DEBUG_ONLY(static bool   _frozen;)
 137 
 138   SpaceManager* _vsm;
 139   SpaceManager* vsm() const { return _vsm; }
 140 
 141   SpaceManager* _class_vsm;
 142   SpaceManager* class_vsm() const { return _class_vsm; }
 143   SpaceManager* get_space_manager(MetadataType mdtype) {
 144     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 145     return mdtype == ClassType ? class_vsm() : vsm();
 146   }
 147 
 148   // Allocate space for metadata of type mdtype. This is space
 149   // within a Metachunk and is used by
 150   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
 151   MetaWord* allocate(size_t word_size, MetadataType mdtype);
 152 
 153   MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
 154 
 155   // Virtual Space lists for both classes and other metadata
 156   static VirtualSpaceList* _space_list;
 157   static VirtualSpaceList* _class_space_list;
 158 
 159   static ChunkManager* _chunk_manager_metadata;
 160   static ChunkManager* _chunk_manager_class;
 161 
 162   static const MetaspaceTracer* _tracer;
 163 
 164  public:
 165   static VirtualSpaceList* space_list()       { return _space_list; }
 166   static VirtualSpaceList* class_space_list() { return _class_space_list; }
 167   static VirtualSpaceList* get_space_list(MetadataType mdtype) {
 168     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 169     return mdtype == ClassType ? class_space_list() : space_list();
 170   }
 171 
 172   static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
 173   static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
 174   static ChunkManager* get_chunk_manager(MetadataType mdtype) {
 175     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 176     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
 177   }
 178 
 179   static const MetaspaceTracer* tracer() { return _tracer; }
 180   static void freeze() {
 181     assert(DumpSharedSpaces, "sanity");
 182     DEBUG_ONLY(_frozen = true;)
 183   }
 184  private:
 185 
 186 #ifdef _LP64
 187   static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
 188 
 189   // Returns true if can use CDS with metaspace allocated as specified address.
 190   static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
 191 
 192   static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
 193 
 194   static void initialize_class_space(ReservedSpace rs);
 195 #endif
 196   size_t class_chunk_size(size_t word_size);
 197 
 198  public:
 199 
 200   Metaspace(Mutex* lock, MetaspaceType type);
 201   ~Metaspace();
 202 
 203   static void ergo_initialize();
 204   static void global_initialize();
 205   static void post_initialize();
 206 
 207   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
 208   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 209 
 210   static size_t reserve_alignment()       { return _reserve_alignment; }
 211   static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
 212   static size_t commit_alignment()        { return _commit_alignment; }
 213   static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
 214 
 215   size_t used_words_slow(MetadataType mdtype) const;
 216   size_t free_words_slow(MetadataType mdtype) const;
 217   size_t capacity_words_slow(MetadataType mdtype) const;
 218 
 219   size_t used_bytes_slow(MetadataType mdtype) const;
 220   size_t capacity_bytes_slow(MetadataType mdtype) const;
 221 
 222   size_t allocated_blocks_bytes() const;
 223   size_t allocated_chunks_bytes() const;
 224 
 225   static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
 226                             MetaspaceObj::Type type, TRAPS);
 227   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
 228 
 229   static bool contains(const void* ptr);
 230   static bool contains_non_shared(const void* ptr);
 231 
 232   void dump(outputStream* const out) const;
 233 
 234   // Free empty virtualspaces
 235   static void purge(MetadataType mdtype);
 236   static void purge();
 237 
 238   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
 239                                    MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
 240 
 241   static const char* metadata_type_name(Metaspace::MetadataType mdtype);
 242 
 243   void print_on(outputStream* st) const;
 244   // Debugging support
 245   void verify();
 246 
 247   static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
 248 
 249   // Return TRUE only if UseCompressedClassPointers is True.
 250   static bool using_class_space() {
 251     return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
 252   }
 253 
 254   static bool is_class_space_allocation(MetadataType mdType) {
 255     return mdType == ClassType && using_class_space();
 256   }
 257 
 258 };
 259 
 260 class MetaspaceAux : AllStatic {
 261   static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
 262 
 263   // These methods iterate over the classloader data graph
 264   // for the given Metaspace type.  These are slow.
 265   static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
 266   static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
 267   static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
 268   static size_t capacity_bytes_slow();
 269 
 270   // Running sum of space in all Metachunks that has been
 271   // allocated to a Metaspace.  This is used instead of
 272   // iterating over all the classloaders. One for each
 273   // type of Metadata
 274   static size_t _capacity_words[Metaspace:: MetadataTypeCount];
 275   // Running sum of space in all Metachunks that
 276   // are being used for metadata. One for each
 277   // type of Metadata.
 278   static size_t _used_words[Metaspace:: MetadataTypeCount];
 279 
 280  public:
 281   // Decrement and increment _allocated_capacity_words
 282   static void dec_capacity(Metaspace::MetadataType type, size_t words);
 283   static void inc_capacity(Metaspace::MetadataType type, size_t words);
 284 
 285   // Decrement and increment _allocated_used_words
 286   static void dec_used(Metaspace::MetadataType type, size_t words);
 287   static void inc_used(Metaspace::MetadataType type, size_t words);
 288 
 289   // Total of space allocated to metadata in all Metaspaces.
 290   // This sums the space used in each Metachunk by
 291   // iterating over the classloader data graph
 292   static size_t used_bytes_slow() {
 293     return used_bytes_slow(Metaspace::ClassType) +
 294            used_bytes_slow(Metaspace::NonClassType);
 295   }
 296 
 297   // Used by MetaspaceCounters
 298   static size_t free_chunks_total_words();
 299   static size_t free_chunks_total_bytes();
 300   static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
 301 
 302   static size_t capacity_words(Metaspace::MetadataType mdtype) {
 303     return _capacity_words[mdtype];
 304   }
 305   static size_t capacity_words() {
 306     return capacity_words(Metaspace::NonClassType) +
 307            capacity_words(Metaspace::ClassType);
 308   }
 309   static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
 310     return capacity_words(mdtype) * BytesPerWord;
 311   }
 312   static size_t capacity_bytes() {
 313     return capacity_words() * BytesPerWord;
 314   }
 315 
 316   static size_t used_words(Metaspace::MetadataType mdtype) {
 317     return _used_words[mdtype];
 318   }
 319   static size_t used_words() {
 320     return used_words(Metaspace::NonClassType) +
 321            used_words(Metaspace::ClassType);
 322   }
 323   static size_t used_bytes(Metaspace::MetadataType mdtype) {
 324     return used_words(mdtype) * BytesPerWord;
 325   }
 326   static size_t used_bytes() {
 327     return used_words() * BytesPerWord;
 328   }
 329 
 330   static size_t free_bytes();
 331   static size_t free_bytes(Metaspace::MetadataType mdtype);
 332 
 333   static size_t reserved_bytes(Metaspace::MetadataType mdtype);
 334   static size_t reserved_bytes() {
 335     return reserved_bytes(Metaspace::ClassType) +
 336            reserved_bytes(Metaspace::NonClassType);
 337   }
 338 
 339   static size_t committed_bytes(Metaspace::MetadataType mdtype);
 340   static size_t committed_bytes() {
 341     return committed_bytes(Metaspace::ClassType) +
 342            committed_bytes(Metaspace::NonClassType);
 343   }
 344 
 345   static size_t min_chunk_size_words();
 346   static size_t min_chunk_size_bytes() {
 347     return min_chunk_size_words() * BytesPerWord;
 348   }
 349 
 350   static void print_cld_metadata(outputStream* out);
 351 
 352   static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
 353   static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
 354 
 355   // Print change in used metadata.
 356   static void print_metaspace_change(size_t prev_metadata_used);
 357   static void print_on(outputStream * out);
 358   static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
 359 
 360   static void print_class_waste(outputStream* out);
 361   static void print_waste(outputStream* out);
 362   static void dump(outputStream* out);
 363   static void verify_free_chunks();
 364   // Checks that the values returned by allocated_capacity_bytes() and
 365   // capacity_bytes_slow() are the same.
 366   static void verify_capacity();
 367   static void verify_used();
 368   static void verify_metrics();
 369 };
 370 
 371 // Metaspace are deallocated when their class loader are GC'ed.
 372 // This class implements a policy for inducing GC's to recover
 373 // Metaspaces.
 374 
 375 class MetaspaceGC : AllStatic {
 376 
 377   // The current high-water-mark for inducing a GC.
 378   // When committed memory of all metaspaces reaches this value,
 379   // a GC is induced and the value is increased. Size is in bytes.
 380   static volatile intptr_t _capacity_until_GC;
 381 
 382   // For a CMS collection, signal that a concurrent collection should
 383   // be started.
 384   static bool _should_concurrent_collect;
 385 
 386   static uint _shrink_factor;
 387 
 388   static size_t shrink_factor() { return _shrink_factor; }
 389   void set_shrink_factor(uint v) { _shrink_factor = v; }
 390 
 391  public:
 392 
 393   static void initialize();
 394   static void post_initialize();
 395 
 396   static size_t capacity_until_GC();
 397   static bool inc_capacity_until_GC(size_t v,
 398                                     size_t* new_cap_until_GC = NULL,
 399                                     size_t* old_cap_until_GC = NULL);
 400   static size_t dec_capacity_until_GC(size_t v);
 401 
 402   static bool should_concurrent_collect() { return _should_concurrent_collect; }
 403   static void set_should_concurrent_collect(bool v) {
 404     _should_concurrent_collect = v;
 405   }
 406 
 407   // The amount to increase the high-water-mark (_capacity_until_GC)
 408   static size_t delta_capacity_until_GC(size_t bytes);
 409 
 410   // Tells if we have can expand metaspace without hitting set limits.
 411   static bool can_expand(size_t words, bool is_class);
 412 
 413   // Returns amount that we can expand without hitting a GC,
 414   // measured in words.
 415   static size_t allowed_expansion();
 416 
 417   // Calculate the new high-water mark at which to induce
 418   // a GC.
 419   static void compute_new_size();
 420 };
 421 
 422 #endif // SHARE_VM_MEMORY_METASPACE_HPP