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
  21  * questions.
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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 class CollectedHeap;
  70 
  71 // Metaspaces each have a  SpaceManager and allocations
  72 // are done by the SpaceManager.  Allocations are done
  73 // out of the current Metachunk.  When the current Metachunk
  74 // is exhausted, the SpaceManager gets a new one from
  75 // the current VirtualSpace.  When the VirtualSpace is exhausted
  76 // the SpaceManager gets a new one.  The SpaceManager
  77 // also manages freelists of available Chunks.
  78 //
  79 // Currently the space manager maintains the list of
  80 // virtual spaces and the list of chunks in use.  Its
  81 // allocate() method returns a block for use as a
  82 // quantum of metadata.
  83 
  84 class Metaspace : public CHeapObj<mtClass> {
  85   friend class VMStructs;
  86   friend class SpaceManager;
  87   friend class VM_CollectForMetadataAllocation;
  88   friend class MetaspaceGC;
  89   friend class MetaspaceUtils;
  90   friend class MetaspaceShared;
  91   friend class CollectedHeap;
  92   friend class PrintCLDMetaspaceInfoClosure;
  93   friend class MetaspaceAllocationTest;
  94 
  95  public:
  96   enum MetadataType {
  97     ClassType,
  98     NonClassType,
  99     MetadataTypeCount
 100   };
 101   enum MetaspaceType {
 102     StandardMetaspaceType,
 103     BootMetaspaceType,
 104     AnonymousMetaspaceType,
 105     ReflectionMetaspaceType
 106   };
 107 
 108  private:
 109   static void verify_global_initialization();
 110 
 111   void initialize(Mutex* lock, MetaspaceType type);
 112 
 113   // Initialize the first chunk for a Metaspace.  Used for
 114   // special cases such as the boot class loader, reflection
 115   // class loader and anonymous class loader.
 116   void initialize_first_chunk(MetaspaceType type, MetadataType mdtype);
 117   Metachunk* get_initialization_chunk(MetaspaceType type, MetadataType mdtype);
 118 
 119   // Align up the word size to the allocation word size
 120   static size_t align_word_size_up(size_t);
 121 
 122   // Aligned size of the metaspace.
 123   static size_t _compressed_class_space_size;
 124 
 125   static size_t compressed_class_space_size() {
 126     return _compressed_class_space_size;
 127   }
 128 
 129   static void set_compressed_class_space_size(size_t size) {
 130     _compressed_class_space_size = size;
 131   }
 132 
 133   static size_t _first_chunk_word_size;
 134   static size_t _first_class_chunk_word_size;
 135 
 136   static size_t _commit_alignment;
 137   static size_t _reserve_alignment;
 138   DEBUG_ONLY(static bool   _frozen;)
 139 
 140   SpaceManager* _vsm;
 141   SpaceManager* vsm() const { return _vsm; }
 142 
 143   SpaceManager* _class_vsm;
 144   SpaceManager* class_vsm() const { return _class_vsm; }
 145   SpaceManager* get_space_manager(MetadataType mdtype) {
 146     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 147     return mdtype == ClassType ? class_vsm() : vsm();
 148   }
 149 
 150   // Allocate space for metadata of type mdtype. This is space
 151   // within a Metachunk and is used by
 152   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
 153   MetaWord* allocate(size_t word_size, MetadataType mdtype);
 154 
 155   MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
 156 
 157   // Virtual Space lists for both classes and other metadata
 158   static VirtualSpaceList* _space_list;
 159   static VirtualSpaceList* _class_space_list;
 160 
 161   static ChunkManager* _chunk_manager_metadata;
 162   static ChunkManager* _chunk_manager_class;
 163 
 164   static const MetaspaceTracer* _tracer;
 165 
 166  public:
 167   static VirtualSpaceList* space_list()       { return _space_list; }
 168   static VirtualSpaceList* class_space_list() { return _class_space_list; }
 169   static VirtualSpaceList* get_space_list(MetadataType mdtype) {
 170     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 171     return mdtype == ClassType ? class_space_list() : space_list();
 172   }
 173 
 174   static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
 175   static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
 176   static ChunkManager* get_chunk_manager(MetadataType mdtype) {
 177     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
 178     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
 179   }
 180 
 181   // convenience function
 182   static ChunkManager* get_chunk_manager(bool is_class) {
 183     return is_class ? chunk_manager_class() : chunk_manager_metadata();
 184   }
 185 
 186   static const MetaspaceTracer* tracer() { return _tracer; }
 187   static void freeze() {
 188     assert(DumpSharedSpaces, "sanity");
 189     DEBUG_ONLY(_frozen = true;)
 190   }
 191 #ifdef _LP64
 192   static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
 193 #endif
 194 
 195  private:
 196 
 197 #ifdef _LP64
 198   static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
 199 
 200   // Returns true if can use CDS with metaspace allocated as specified address.
 201   static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
 202 
 203   static void initialize_class_space(ReservedSpace rs);
 204 #endif
 205   size_t class_chunk_size(size_t word_size);
 206 
 207  public:
 208 
 209   Metaspace(Mutex* lock, MetaspaceType type);
 210   ~Metaspace();
 211 
 212   static void ergo_initialize();
 213   static void global_initialize();
 214   static void post_initialize();
 215 
 216   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
 217   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 218 
 219   static size_t reserve_alignment()       { return _reserve_alignment; }
 220   static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
 221   static size_t commit_alignment()        { return _commit_alignment; }
 222   static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
 223 
 224   size_t used_words_slow(MetadataType mdtype) const;
 225   size_t free_words_slow(MetadataType mdtype) const;
 226   size_t capacity_words_slow(MetadataType mdtype) const;
 227 
 228   size_t used_bytes_slow(MetadataType mdtype) const;
 229   size_t capacity_bytes_slow(MetadataType mdtype) const;
 230 
 231   size_t allocated_blocks_bytes() const;
 232   size_t allocated_chunks_bytes() const;
 233 
 234   static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
 235                             MetaspaceObj::Type type, TRAPS);
 236   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
 237 
 238   static bool contains(const void* ptr);
 239   static bool contains_non_shared(const void* ptr);
 240 
 241   void dump(outputStream* const out) const;
 242 
 243   // Free empty virtualspaces
 244   static void purge(MetadataType mdtype);
 245   static void purge();
 246 
 247   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
 248                                    MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
 249 
 250   static const char* metadata_type_name(Metaspace::MetadataType mdtype);
 251 
 252   void print_on(outputStream* st) const;
 253   // Debugging support
 254   void verify();
 255 
 256   static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
 257 
 258   // Return TRUE only if UseCompressedClassPointers is True.
 259   static bool using_class_space() {
 260     return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
 261   }
 262 
 263   static bool is_class_space_allocation(MetadataType mdType) {
 264     return mdType == ClassType && using_class_space();
 265   }
 266 
 267 };
 268 
 269 class MetaspaceUtils : AllStatic {
 270   static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
 271 
 272   // These methods iterate over the classloader data graph
 273   // for the given Metaspace type.  These are slow.
 274   static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
 275   static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
 276   static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
 277   static size_t capacity_bytes_slow();
 278 
 279   // Running sum of space in all Metachunks that has been
 280   // allocated to a Metaspace.  This is used instead of
 281   // iterating over all the classloaders. One for each
 282   // type of Metadata
 283   static size_t _capacity_words[Metaspace:: MetadataTypeCount];
 284   // Running sum of space in all Metachunks that
 285   // are being used for metadata. One for each
 286   // type of Metadata.
 287   static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
 288 
 289  public:
 290   // Decrement and increment _allocated_capacity_words
 291   static void dec_capacity(Metaspace::MetadataType type, size_t words);
 292   static void inc_capacity(Metaspace::MetadataType type, size_t words);
 293 
 294   // Decrement and increment _allocated_used_words
 295   static void dec_used(Metaspace::MetadataType type, size_t words);
 296   static void inc_used(Metaspace::MetadataType type, size_t words);
 297 
 298   // Total of space allocated to metadata in all Metaspaces.
 299   // This sums the space used in each Metachunk by
 300   // iterating over the classloader data graph
 301   static size_t used_bytes_slow() {
 302     return used_bytes_slow(Metaspace::ClassType) +
 303            used_bytes_slow(Metaspace::NonClassType);
 304   }
 305 
 306   // Used by MetaspaceCounters
 307   static size_t free_chunks_total_words();
 308   static size_t free_chunks_total_bytes();
 309   static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
 310 
 311   static size_t capacity_words(Metaspace::MetadataType mdtype) {
 312     return _capacity_words[mdtype];
 313   }
 314   static size_t capacity_words() {
 315     return capacity_words(Metaspace::NonClassType) +
 316            capacity_words(Metaspace::ClassType);
 317   }
 318   static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
 319     return capacity_words(mdtype) * BytesPerWord;
 320   }
 321   static size_t capacity_bytes() {
 322     return capacity_words() * BytesPerWord;
 323   }
 324 
 325   static size_t used_words(Metaspace::MetadataType mdtype) {
 326     return _used_words[mdtype];
 327   }
 328   static size_t used_words() {
 329     return used_words(Metaspace::NonClassType) +
 330            used_words(Metaspace::ClassType);
 331   }
 332   static size_t used_bytes(Metaspace::MetadataType mdtype) {
 333     return used_words(mdtype) * BytesPerWord;
 334   }
 335   static size_t used_bytes() {
 336     return used_words() * BytesPerWord;
 337   }
 338 
 339   static size_t free_bytes();
 340   static size_t free_bytes(Metaspace::MetadataType mdtype);
 341 
 342   static size_t reserved_bytes(Metaspace::MetadataType mdtype);
 343   static size_t reserved_bytes() {
 344     return reserved_bytes(Metaspace::ClassType) +
 345            reserved_bytes(Metaspace::NonClassType);
 346   }
 347 
 348   static size_t committed_bytes(Metaspace::MetadataType mdtype);
 349   static size_t committed_bytes() {
 350     return committed_bytes(Metaspace::ClassType) +
 351            committed_bytes(Metaspace::NonClassType);
 352   }
 353 
 354   static size_t min_chunk_size_words();
 355   static size_t min_chunk_size_bytes() {
 356     return min_chunk_size_words() * BytesPerWord;
 357   }
 358 
 359   static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
 360 
 361   static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
 362   static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
 363 
 364   // Print change in used metadata.
 365   static void print_metaspace_change(size_t prev_metadata_used);
 366   static void print_on(outputStream * out);
 367   static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
 368 
 369   static void print_class_waste(outputStream* out);
 370   static void print_waste(outputStream* out);
 371 
 372   // Prints an ASCII representation of the given space.
 373   static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
 374 
 375   static void dump(outputStream* out);
 376   static void verify_free_chunks();
 377   // Checks that the values returned by allocated_capacity_bytes() and
 378   // capacity_bytes_slow() are the same.
 379   static void verify_capacity();
 380   static void verify_used();
 381   static void verify_metrics();
 382 };
 383 
 384 // Metaspace are deallocated when their class loader are GC'ed.
 385 // This class implements a policy for inducing GC's to recover
 386 // Metaspaces.
 387 
 388 class MetaspaceGC : AllStatic {
 389 
 390   // The current high-water-mark for inducing a GC.
 391   // When committed memory of all metaspaces reaches this value,
 392   // a GC is induced and the value is increased. Size is in bytes.
 393   static volatile intptr_t _capacity_until_GC;
 394 
 395   // For a CMS collection, signal that a concurrent collection should
 396   // be started.
 397   static bool _should_concurrent_collect;
 398 
 399   static uint _shrink_factor;
 400 
 401   static size_t shrink_factor() { return _shrink_factor; }
 402   void set_shrink_factor(uint v) { _shrink_factor = v; }
 403 
 404  public:
 405 
 406   static void initialize();
 407   static void post_initialize();
 408 
 409   static size_t capacity_until_GC();
 410   static bool inc_capacity_until_GC(size_t v,
 411                                     size_t* new_cap_until_GC = NULL,
 412                                     size_t* old_cap_until_GC = NULL);
 413   static size_t dec_capacity_until_GC(size_t v);
 414 
 415   static bool should_concurrent_collect() { return _should_concurrent_collect; }
 416   static void set_should_concurrent_collect(bool v) {
 417     _should_concurrent_collect = v;
 418   }
 419 
 420   // The amount to increase the high-water-mark (_capacity_until_GC)
 421   static size_t delta_capacity_until_GC(size_t bytes);
 422 
 423   // Tells if we have can expand metaspace without hitting set limits.
 424   static bool can_expand(size_t words, bool is_class);
 425 
 426   // Returns amount that we can expand without hitting a GC,
 427   // measured in words.
 428   static size_t allowed_expansion();
 429 
 430   // Calculate the new high-water mark at which to induce
 431   // a GC.
 432   static void compute_new_size();
 433 };
 434 
 435 #endif // SHARE_VM_MEMORY_METASPACE_HPP