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 MetaspaceUtils;
  89   friend class MetaspaceShared;
  90   friend class CollectedHeap;
  91   friend class PrintCLDMetaspaceInfoClosure;
  92   friend class MetaspaceAllocationTest;
  93 
  94  public:
  95   enum MetadataType {
  96     ClassType,
  97     NonClassType,
  98     MetadataTypeCount
  99   };
 100   enum MetaspaceType {
 101     StandardMetaspaceType,
 102     BootMetaspaceType,
 103     AnonymousMetaspaceType,
 104     ReflectionMetaspaceType
 105   };
 106 
 107  private:
 108   static void verify_global_initialization();
 109 
 110   void initialize(Mutex* lock, MetaspaceType type);
 111 
 112   // Initialize the first chunk for a Metaspace.  Used for
 113   // special cases such as the boot class loader, reflection
 114   // class loader and anonymous class loader.
 115   void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
 116   Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
 117 
 118   // Align up the word size to the allocation word size
 119   static size_t align_word_size_up(size_t);
 120 
 121   // Aligned size of the metaspace.
 122   static size_t _compressed_class_space_size;
 123 
 124   static size_t compressed_class_space_size() {
 125     return _compressed_class_space_size;
 126   }
 127 
 128   static void set_compressed_class_space_size(size_t size) {
 129     _compressed_class_space_size = size;
 130   }
 131 
 132   static size_t _first_chunk_word_size;
 133   static size_t _first_class_chunk_word_size;
 134 
 135   static size_t _commit_alignment;
 136   static size_t _reserve_alignment;
 137   DEBUG_ONLY(static bool   _frozen;)
 138 
 139   SpaceManager* _vsm;
 140   SpaceManager* vsm() const { return _vsm; }
 141 
 142   SpaceManager* _class_vsm;
 143   SpaceManager* class_vsm() const { return _class_vsm; }
 144   SpaceManager* get_space_manager(MetadataType mdtype) {
 145     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 146     return mdtype == ClassType ? class_vsm() : vsm();
 147   }
 148 
 149   // Allocate space for metadata of type mdtype. This is space
 150   // within a Metachunk and is used by
 151   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
 152   MetaWord* allocate(size_t word_size, MetadataType mdtype);
 153 
 154   MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
 155 
 156   // Virtual Space lists for both classes and other metadata
 157   static VirtualSpaceList* _space_list;
 158   static VirtualSpaceList* _class_space_list;
 159 
 160   static ChunkManager* _chunk_manager_metadata;
 161   static ChunkManager* _chunk_manager_class;
 162 
 163   static const MetaspaceTracer* _tracer;
 164 
 165  public:
 166   static VirtualSpaceList* space_list()       { return _space_list; }
 167   static VirtualSpaceList* class_space_list() { return _class_space_list; }
 168   static VirtualSpaceList* get_space_list(MetadataType mdtype) {
 169     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 170     return mdtype == ClassType ? class_space_list() : space_list();
 171   }
 172 
 173   static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
 174   static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
 175   static ChunkManager* get_chunk_manager(MetadataType mdtype) {
 176     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 177     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
 178   }
 179 
 180   // convenience function
 181   static ChunkManager* get_chunk_manager(bool is_class) {
 182     return is_class ? chunk_manager_class() : chunk_manager_metadata();
 183   }
 184 
 185   static const MetaspaceTracer* tracer() { return _tracer; }
 186   static void freeze() {
 187     assert(DumpSharedSpaces, "sanity");
 188     DEBUG_ONLY(_frozen = true;)
 189   }
 190 #ifdef _LP64
 191   static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
 192 #endif
 193 
 194  private:
 195 
 196 #ifdef _LP64
 197   static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
 198 
 199   // Returns true if can use CDS with metaspace allocated as specified address.
 200   static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
 201 
 202   static void initialize_class_space(ReservedSpace rs);
 203 #endif
 204   size_t class_chunk_size(size_t word_size);
 205 
 206  public:
 207 
 208   Metaspace(Mutex* lock, MetaspaceType type);
 209   ~Metaspace();
 210 
 211   static void ergo_initialize();
 212   static void global_initialize();
 213   static void post_initialize();
 214 
 215   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
 216   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 217 
 218   static size_t reserve_alignment()       { return _reserve_alignment; }
 219   static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
 220   static size_t commit_alignment()        { return _commit_alignment; }
 221   static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
 222 
 223   size_t used_words_slow(MetadataType mdtype) const;
 224   size_t free_words_slow(MetadataType mdtype) const;
 225   size_t capacity_words_slow(MetadataType mdtype) const;
 226 
 227   size_t used_bytes_slow(MetadataType mdtype) const;
 228   size_t capacity_bytes_slow(MetadataType mdtype) const;
 229 
 230   size_t allocated_blocks_bytes() const;
 231   size_t allocated_chunks_bytes() const;
 232 
 233   static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
 234                             MetaspaceObj::Type type, TRAPS);
 235   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
 236 
 237   static bool contains(const void* ptr);
 238   static bool contains_non_shared(const void* ptr);
 239 
 240   void dump(outputStream* const out) const;
 241 
 242   // Free empty virtualspaces
 243   static void purge(MetadataType mdtype);
 244   static void purge();
 245 
 246   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
 247                                    MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
 248 
 249   static const char* metadata_type_name(Metaspace::MetadataType mdtype);
 250 
 251   void print_on(outputStream* st) const;
 252   // Debugging support
 253   void verify();
 254 
 255   static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
 256 
 257   // Return TRUE only if UseCompressedClassPointers is True.
 258   static bool using_class_space() {
 259     return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
 260   }
 261 
 262   static bool is_class_space_allocation(MetadataType mdType) {
 263     return mdType == ClassType && using_class_space();
 264   }
 265 
 266 };
 267 
 268 class MetaspaceUtils : AllStatic {
 269   static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
 270 
 271   // These methods iterate over the classloader data graph
 272   // for the given Metaspace type.  These are slow.
 273   static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
 274   static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
 275   static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
 276   static size_t capacity_bytes_slow();
 277 
 278   // Running sum of space in all Metachunks that has been
 279   // allocated to a Metaspace.  This is used instead of
 280   // iterating over all the classloaders. One for each
 281   // type of Metadata
 282   static size_t _capacity_words[Metaspace:: MetadataTypeCount];
 283   // Running sum of space in all Metachunks that
 284   // are being used for metadata. One for each
 285   // type of Metadata.
 286   static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
 287 
 288  public:
 289   // Decrement and increment _allocated_capacity_words
 290   static void dec_capacity(Metaspace::MetadataType type, size_t words);
 291   static void inc_capacity(Metaspace::MetadataType type, size_t words);
 292 
 293   // Decrement and increment _allocated_used_words
 294   static void dec_used(Metaspace::MetadataType type, size_t words);
 295   static void inc_used(Metaspace::MetadataType type, size_t words);
 296 
 297   // Total of space allocated to metadata in all Metaspaces.
 298   // This sums the space used in each Metachunk by
 299   // iterating over the classloader data graph
 300   static size_t used_bytes_slow() {
 301     return used_bytes_slow(Metaspace::ClassType) +
 302            used_bytes_slow(Metaspace::NonClassType);
 303   }
 304 
 305   // Used by MetaspaceCounters
 306   static size_t free_chunks_total_words();
 307   static size_t free_chunks_total_bytes();
 308   static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
 309 
 310   static size_t capacity_words(Metaspace::MetadataType mdtype) {
 311     return _capacity_words[mdtype];
 312   }
 313   static size_t capacity_words() {
 314     return capacity_words(Metaspace::NonClassType) +
 315            capacity_words(Metaspace::ClassType);
 316   }
 317   static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
 318     return capacity_words(mdtype) * BytesPerWord;
 319   }
 320   static size_t capacity_bytes() {
 321     return capacity_words() * BytesPerWord;
 322   }
 323 
 324   static size_t used_words(Metaspace::MetadataType mdtype) {
 325     return _used_words[mdtype];
 326   }
 327   static size_t used_words() {
 328     return used_words(Metaspace::NonClassType) +
 329            used_words(Metaspace::ClassType);
 330   }
 331   static size_t used_bytes(Metaspace::MetadataType mdtype) {
 332     return used_words(mdtype) * BytesPerWord;
 333   }
 334   static size_t used_bytes() {
 335     return used_words() * BytesPerWord;
 336   }
 337 
 338   static size_t free_bytes();
 339   static size_t free_bytes(Metaspace::MetadataType mdtype);
 340 
 341   static size_t reserved_bytes(Metaspace::MetadataType mdtype);
 342   static size_t reserved_bytes() {
 343     return reserved_bytes(Metaspace::ClassType) +
 344            reserved_bytes(Metaspace::NonClassType);
 345   }
 346 
 347   static size_t committed_bytes(Metaspace::MetadataType mdtype);
 348   static size_t committed_bytes() {
 349     return committed_bytes(Metaspace::ClassType) +
 350            committed_bytes(Metaspace::NonClassType);
 351   }
 352 
 353   static size_t min_chunk_size_words();
 354   static size_t min_chunk_size_bytes() {
 355     return min_chunk_size_words() * BytesPerWord;
 356   }
 357 
 358   static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
 359 
 360   static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
 361   static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
 362 
 363   // Print change in used metadata.
 364   static void print_metaspace_change(size_t prev_metadata_used);
 365   static void print_on(outputStream * out);
 366   static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
 367 
 368   static void print_class_waste(outputStream* out);
 369   static void print_waste(outputStream* out);
 370 
 371   // Prints an ASCII representation of the given space.
 372   static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
 373 
 374   static void dump(outputStream* out);
 375   static void verify_free_chunks();
 376   // Checks that the values returned by allocated_capacity_bytes() and
 377   // capacity_bytes_slow() are the same.
 378   static void verify_capacity();
 379   static void verify_used();
 380   static void verify_metrics();
 381 };
 382 
 383 // Metaspace are deallocated when their class loader are GC'ed.
 384 // This class implements a policy for inducing GC's to recover
 385 // Metaspaces.
 386 
 387 class MetaspaceGC : AllStatic {
 388 
 389   // The current high-water-mark for inducing a GC.
 390   // When committed memory of all metaspaces reaches this value,
 391   // a GC is induced and the value is increased. Size is in bytes.
 392   static volatile intptr_t _capacity_until_GC;
 393 
 394   // For a CMS collection, signal that a concurrent collection should
 395   // be started.
 396   static bool _should_concurrent_collect;
 397 
 398   static uint _shrink_factor;
 399 
 400   static size_t shrink_factor() { return _shrink_factor; }
 401   void set_shrink_factor(uint v) { _shrink_factor = v; }
 402 
 403  public:
 404 
 405   static void initialize();
 406   static void post_initialize();
 407 
 408   static size_t capacity_until_GC();
 409   static bool inc_capacity_until_GC(size_t v,
 410                                     size_t* new_cap_until_GC = NULL,
 411                                     size_t* old_cap_until_GC = NULL);
 412   static size_t dec_capacity_until_GC(size_t v);
 413 
 414   static bool should_concurrent_collect() { return _should_concurrent_collect; }
 415   static void set_should_concurrent_collect(bool v) {
 416     _should_concurrent_collect = v;
 417   }
 418 
 419   // The amount to increase the high-water-mark (_capacity_until_GC)
 420   static size_t delta_capacity_until_GC(size_t bytes);
 421 
 422   // Tells if we have can expand metaspace without hitting set limits.
 423   static bool can_expand(size_t words, bool is_class);
 424 
 425   // Returns amount that we can expand without hitting a GC,
 426   // measured in words.
 427   static size_t allowed_expansion();
 428 
 429   // Calculate the new high-water mark at which to induce
 430   // a GC.
 431   static void compute_new_size();
 432 };
 433 
 434 #endif // SHARE_VM_MEMORY_METASPACE_HPP