1 /*
   2  * Copyright (c) 2011, 2014, 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 #include "precompiled.hpp"
  25 #include "gc_interface/collectedHeap.hpp"
  26 #include "memory/allocation.hpp"
  27 #include "memory/binaryTreeDictionary.hpp"
  28 #include "memory/freeList.hpp"
  29 #include "memory/collectorPolicy.hpp"
  30 #include "memory/filemap.hpp"
  31 #include "memory/freeList.hpp"
  32 #include "memory/gcLocker.hpp"
  33 #include "memory/metachunk.hpp"
  34 #include "memory/metaspace.hpp"
  35 #include "memory/metaspaceGCThresholdUpdater.hpp"
  36 #include "memory/metaspaceShared.hpp"
  37 #include "memory/metaspaceTracer.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "memory/universe.hpp"
  40 #include "runtime/atomic.inline.hpp"
  41 #include "runtime/globals.hpp"
  42 #include "runtime/init.hpp"
  43 #include "runtime/java.hpp"
  44 #include "runtime/mutex.hpp"
  45 #include "runtime/orderAccess.inline.hpp"
  46 #include "services/memTracker.hpp"
  47 #include "services/memoryService.hpp"
  48 #include "utilities/copy.hpp"
  49 #include "utilities/debug.hpp"
  50 
  51 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  52 
  53 typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary;
  54 typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;
  55 
  56 // Set this constant to enable slow integrity checking of the free chunk lists
  57 const bool metaspace_slow_verify = false;
  58 
  59 size_t const allocation_from_dictionary_limit = 4 * K;
  60 
  61 MetaWord* last_allocated = 0;
  62 
  63 size_t Metaspace::_compressed_class_space_size;
  64 const MetaspaceTracer* Metaspace::_tracer = NULL;
  65 
  66 // Used in declarations in SpaceManager and ChunkManager
  67 enum ChunkIndex {
  68   ZeroIndex = 0,
  69   SpecializedIndex = ZeroIndex,
  70   SmallIndex = SpecializedIndex + 1,
  71   MediumIndex = SmallIndex + 1,
  72   HumongousIndex = MediumIndex + 1,
  73   NumberOfFreeLists = 3,
  74   NumberOfInUseLists = 4
  75 };
  76 
  77 enum ChunkSizes {    // in words.
  78   ClassSpecializedChunk = 128,
  79   SpecializedChunk = 128,
  80   ClassSmallChunk = 256,
  81   SmallChunk = 512,
  82   ClassMediumChunk = 4 * K,
  83   MediumChunk = 8 * K
  84 };
  85 
  86 static ChunkIndex next_chunk_index(ChunkIndex i) {
  87   assert(i < NumberOfInUseLists, "Out of bound");
  88   return (ChunkIndex) (i+1);
  89 }
  90 
  91 volatile intptr_t MetaspaceGC::_capacity_until_GC = 0;
  92 uint MetaspaceGC::_shrink_factor = 0;
  93 bool MetaspaceGC::_should_concurrent_collect = false;
  94 
  95 typedef class FreeList<Metachunk> ChunkList;
  96 
  97 // Manages the global free lists of chunks.
  98 class ChunkManager : public CHeapObj<mtInternal> {
  99   friend class TestVirtualSpaceNodeTest;
 100 
 101   // Free list of chunks of different sizes.
 102   //   SpecializedChunk
 103   //   SmallChunk
 104   //   MediumChunk
 105   //   HumongousChunk
 106   ChunkList _free_chunks[NumberOfFreeLists];
 107 
 108   //   HumongousChunk
 109   ChunkTreeDictionary _humongous_dictionary;
 110 
 111   // ChunkManager in all lists of this type
 112   size_t _free_chunks_total;
 113   size_t _free_chunks_count;
 114 
 115   void dec_free_chunks_total(size_t v) {
 116     assert(_free_chunks_count > 0 &&
 117              _free_chunks_total > 0,
 118              "About to go negative");
 119     Atomic::add_ptr(-1, &_free_chunks_count);
 120     jlong minus_v = (jlong) - (jlong) v;
 121     Atomic::add_ptr(minus_v, &_free_chunks_total);
 122   }
 123 
 124   // Debug support
 125 
 126   size_t sum_free_chunks();
 127   size_t sum_free_chunks_count();
 128 
 129   void locked_verify_free_chunks_total();
 130   void slow_locked_verify_free_chunks_total() {
 131     if (metaspace_slow_verify) {
 132       locked_verify_free_chunks_total();
 133     }
 134   }
 135   void locked_verify_free_chunks_count();
 136   void slow_locked_verify_free_chunks_count() {
 137     if (metaspace_slow_verify) {
 138       locked_verify_free_chunks_count();
 139     }
 140   }
 141   void verify_free_chunks_count();
 142 
 143  public:
 144 
 145   ChunkManager(size_t specialized_size, size_t small_size, size_t medium_size)
 146       : _free_chunks_total(0), _free_chunks_count(0) {
 147     _free_chunks[SpecializedIndex].set_size(specialized_size);
 148     _free_chunks[SmallIndex].set_size(small_size);
 149     _free_chunks[MediumIndex].set_size(medium_size);
 150   }
 151 
 152   // add or delete (return) a chunk to the global freelist.
 153   Metachunk* chunk_freelist_allocate(size_t word_size);
 154 
 155   // Map a size to a list index assuming that there are lists
 156   // for special, small, medium, and humongous chunks.
 157   static ChunkIndex list_index(size_t size);
 158 
 159   // Remove the chunk from its freelist.  It is
 160   // expected to be on one of the _free_chunks[] lists.
 161   void remove_chunk(Metachunk* chunk);
 162 
 163   // Add the simple linked list of chunks to the freelist of chunks
 164   // of type index.
 165   void return_chunks(ChunkIndex index, Metachunk* chunks);
 166 
 167   // Total of the space in the free chunks list
 168   size_t free_chunks_total_words();
 169   size_t free_chunks_total_bytes();
 170 
 171   // Number of chunks in the free chunks list
 172   size_t free_chunks_count();
 173 
 174   void inc_free_chunks_total(size_t v, size_t count = 1) {
 175     Atomic::add_ptr(count, &_free_chunks_count);
 176     Atomic::add_ptr(v, &_free_chunks_total);
 177   }
 178   ChunkTreeDictionary* humongous_dictionary() {
 179     return &_humongous_dictionary;
 180   }
 181 
 182   ChunkList* free_chunks(ChunkIndex index);
 183 
 184   // Returns the list for the given chunk word size.
 185   ChunkList* find_free_chunks_list(size_t word_size);
 186 
 187   // Remove from a list by size.  Selects list based on size of chunk.
 188   Metachunk* free_chunks_get(size_t chunk_word_size);
 189 
 190 #define index_bounds_check(index)                                         \
 191   assert(index == SpecializedIndex ||                                     \
 192          index == SmallIndex ||                                           \
 193          index == MediumIndex ||                                          \
 194          index == HumongousIndex, err_msg("Bad index: %d", (int) index))
 195 
 196   size_t num_free_chunks(ChunkIndex index) const {
 197     index_bounds_check(index);
 198 
 199     if (index == HumongousIndex) {
 200       return _humongous_dictionary.total_free_blocks();
 201     }
 202 
 203     ssize_t count = _free_chunks[index].count();
 204     return count == -1 ? 0 : (size_t) count;
 205   }
 206 
 207   size_t size_free_chunks_in_bytes(ChunkIndex index) const {
 208     index_bounds_check(index);
 209 
 210     size_t word_size = 0;
 211     if (index == HumongousIndex) {
 212       word_size = _humongous_dictionary.total_size();
 213     } else {
 214       const size_t size_per_chunk_in_words = _free_chunks[index].size();
 215       word_size = size_per_chunk_in_words * num_free_chunks(index);
 216     }
 217 
 218     return word_size * BytesPerWord;
 219   }
 220 
 221   MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
 222     return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
 223                                          num_free_chunks(SmallIndex),
 224                                          num_free_chunks(MediumIndex),
 225                                          num_free_chunks(HumongousIndex),
 226                                          size_free_chunks_in_bytes(SpecializedIndex),
 227                                          size_free_chunks_in_bytes(SmallIndex),
 228                                          size_free_chunks_in_bytes(MediumIndex),
 229                                          size_free_chunks_in_bytes(HumongousIndex));
 230   }
 231 
 232   // Debug support
 233   void verify();
 234   void slow_verify() {
 235     if (metaspace_slow_verify) {
 236       verify();
 237     }
 238   }
 239   void locked_verify();
 240   void slow_locked_verify() {
 241     if (metaspace_slow_verify) {
 242       locked_verify();
 243     }
 244   }
 245   void verify_free_chunks_total();
 246 
 247   void locked_print_free_chunks(outputStream* st);
 248   void locked_print_sum_free_chunks(outputStream* st);
 249 
 250   void print_on(outputStream* st) const;
 251 };
 252 
 253 // Used to manage the free list of Metablocks (a block corresponds
 254 // to the allocation of a quantum of metadata).
 255 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
 256   BlockTreeDictionary* _dictionary;
 257 
 258   // Only allocate and split from freelist if the size of the allocation
 259   // is at least 1/4th the size of the available block.
 260   const static int WasteMultiplier = 4;
 261 
 262   // Accessors
 263   BlockTreeDictionary* dictionary() const { return _dictionary; }
 264 
 265  public:
 266   BlockFreelist();
 267   ~BlockFreelist();
 268 
 269   // Get and return a block to the free list
 270   MetaWord* get_block(size_t word_size);
 271   void return_block(MetaWord* p, size_t word_size);
 272 
 273   size_t total_size() {
 274   if (dictionary() == NULL) {
 275     return 0;
 276   } else {
 277     return dictionary()->total_size();
 278   }
 279 }
 280 
 281   void print_on(outputStream* st) const;
 282 };
 283 
 284 // A VirtualSpaceList node.
 285 class VirtualSpaceNode : public CHeapObj<mtClass> {
 286   friend class VirtualSpaceList;
 287 
 288   // Link to next VirtualSpaceNode
 289   VirtualSpaceNode* _next;
 290 
 291   // total in the VirtualSpace
 292   MemRegion _reserved;
 293   ReservedSpace _rs;
 294   VirtualSpace _virtual_space;
 295   MetaWord* _top;
 296   // count of chunks contained in this VirtualSpace
 297   uintx _container_count;
 298 
 299   // Convenience functions to access the _virtual_space
 300   char* low()  const { return virtual_space()->low(); }
 301   char* high() const { return virtual_space()->high(); }
 302 
 303   // The first Metachunk will be allocated at the bottom of the
 304   // VirtualSpace
 305   Metachunk* first_chunk() { return (Metachunk*) bottom(); }
 306 
 307   // Committed but unused space in the virtual space
 308   size_t free_words_in_vs() const;
 309  public:
 310 
 311   VirtualSpaceNode(size_t byte_size);
 312   VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs), _container_count(0) {}
 313   ~VirtualSpaceNode();
 314 
 315   // Convenience functions for logical bottom and end
 316   MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
 317   MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
 318 
 319   bool contains(const void* ptr) { return ptr >= low() && ptr < high(); }
 320 
 321   size_t reserved_words() const  { return _virtual_space.reserved_size() / BytesPerWord; }
 322   size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; }
 323 
 324   bool is_pre_committed() const { return _virtual_space.special(); }
 325 
 326   // address of next available space in _virtual_space;
 327   // Accessors
 328   VirtualSpaceNode* next() { return _next; }
 329   void set_next(VirtualSpaceNode* v) { _next = v; }
 330 
 331   void set_reserved(MemRegion const v) { _reserved = v; }
 332   void set_top(MetaWord* v) { _top = v; }
 333 
 334   // Accessors
 335   MemRegion* reserved() { return &_reserved; }
 336   VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
 337 
 338   // Returns true if "word_size" is available in the VirtualSpace
 339   bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); }
 340 
 341   MetaWord* top() const { return _top; }
 342   void inc_top(size_t word_size) { _top += word_size; }
 343 
 344   uintx container_count() { return _container_count; }
 345   void inc_container_count();
 346   void dec_container_count();
 347 #ifdef ASSERT
 348   uint container_count_slow();
 349   void verify_container_count();
 350 #endif
 351 
 352   // used and capacity in this single entry in the list
 353   size_t used_words_in_vs() const;
 354   size_t capacity_words_in_vs() const;
 355 
 356   bool initialize();
 357 
 358   // get space from the virtual space
 359   Metachunk* take_from_committed(size_t chunk_word_size);
 360 
 361   // Allocate a chunk from the virtual space and return it.
 362   Metachunk* get_chunk_vs(size_t chunk_word_size);
 363 
 364   // Expands/shrinks the committed space in a virtual space.  Delegates
 365   // to Virtualspace
 366   bool expand_by(size_t min_words, size_t preferred_words);
 367 
 368   // In preparation for deleting this node, remove all the chunks
 369   // in the node from any freelist.
 370   void purge(ChunkManager* chunk_manager);
 371 
 372   // If an allocation doesn't fit in the current node a new node is created.
 373   // Allocate chunks out of the remaining committed space in this node
 374   // to avoid wasting that memory.
 375   // This always adds up because all the chunk sizes are multiples of
 376   // the smallest chunk size.
 377   void retire(ChunkManager* chunk_manager);
 378 
 379 #ifdef ASSERT
 380   // Debug support
 381   void mangle();
 382 #endif
 383 
 384   void print_on(outputStream* st) const;
 385 };
 386 
 387 #define assert_is_ptr_aligned(ptr, alignment) \
 388   assert(is_ptr_aligned(ptr, alignment),      \
 389     err_msg(PTR_FORMAT " is not aligned to "  \
 390       SIZE_FORMAT, ptr, alignment))
 391 
 392 #define assert_is_size_aligned(size, alignment) \
 393   assert(is_size_aligned(size, alignment),      \
 394     err_msg(SIZE_FORMAT " is not aligned to "   \
 395        SIZE_FORMAT, size, alignment))
 396 
 397 
 398 // Decide if large pages should be committed when the memory is reserved.
 399 static bool should_commit_large_pages_when_reserving(size_t bytes) {
 400   if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) {
 401     size_t words = bytes / BytesPerWord;
 402     bool is_class = false; // We never reserve large pages for the class space.
 403     if (MetaspaceGC::can_expand(words, is_class) &&
 404         MetaspaceGC::allowed_expansion() >= words) {
 405       return true;
 406     }
 407   }
 408 
 409   return false;
 410 }
 411 
 412   // byte_size is the size of the associated virtualspace.
 413 VirtualSpaceNode::VirtualSpaceNode(size_t bytes) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
 414   assert_is_size_aligned(bytes, Metaspace::reserve_alignment());
 415 
 416 #if INCLUDE_CDS
 417   // This allocates memory with mmap.  For DumpSharedspaces, try to reserve
 418   // configurable address, generally at the top of the Java heap so other
 419   // memory addresses don't conflict.
 420   if (DumpSharedSpaces) {
 421     bool large_pages = false; // No large pages when dumping the CDS archive.
 422     char* shared_base = (char*)align_ptr_up((char*)SharedBaseAddress, Metaspace::reserve_alignment());
 423 
 424     _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages, shared_base, 0);
 425     if (_rs.is_reserved()) {
 426       assert(shared_base == 0 || _rs.base() == shared_base, "should match");
 427     } else {
 428       // Get a mmap region anywhere if the SharedBaseAddress fails.
 429       _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
 430     }
 431     MetaspaceShared::set_shared_rs(&_rs);
 432   } else
 433 #endif
 434   {
 435     bool large_pages = should_commit_large_pages_when_reserving(bytes);
 436 
 437     _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
 438   }
 439 
 440   if (_rs.is_reserved()) {
 441     assert(_rs.base() != NULL, "Catch if we get a NULL address");
 442     assert(_rs.size() != 0, "Catch if we get a 0 size");
 443     assert_is_ptr_aligned(_rs.base(), Metaspace::reserve_alignment());
 444     assert_is_size_aligned(_rs.size(), Metaspace::reserve_alignment());
 445 
 446     MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
 447   }
 448 }
 449 
 450 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
 451   Metachunk* chunk = first_chunk();
 452   Metachunk* invalid_chunk = (Metachunk*) top();
 453   while (chunk < invalid_chunk ) {
 454     assert(chunk->is_tagged_free(), "Should be tagged free");
 455     MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
 456     chunk_manager->remove_chunk(chunk);
 457     assert(chunk->next() == NULL &&
 458            chunk->prev() == NULL,
 459            "Was not removed from its list");
 460     chunk = (Metachunk*) next;
 461   }
 462 }
 463 
 464 #ifdef ASSERT
 465 uint VirtualSpaceNode::container_count_slow() {
 466   uint count = 0;
 467   Metachunk* chunk = first_chunk();
 468   Metachunk* invalid_chunk = (Metachunk*) top();
 469   while (chunk < invalid_chunk ) {
 470     MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
 471     // Don't count the chunks on the free lists.  Those are
 472     // still part of the VirtualSpaceNode but not currently
 473     // counted.
 474     if (!chunk->is_tagged_free()) {
 475       count++;
 476     }
 477     chunk = (Metachunk*) next;
 478   }
 479   return count;
 480 }
 481 #endif
 482 
 483 // List of VirtualSpaces for metadata allocation.
 484 class VirtualSpaceList : public CHeapObj<mtClass> {
 485   friend class VirtualSpaceNode;
 486 
 487   enum VirtualSpaceSizes {
 488     VirtualSpaceSize = 256 * K
 489   };
 490 
 491   // Head of the list
 492   VirtualSpaceNode* _virtual_space_list;
 493   // virtual space currently being used for allocations
 494   VirtualSpaceNode* _current_virtual_space;
 495 
 496   // Is this VirtualSpaceList used for the compressed class space
 497   bool _is_class;
 498 
 499   // Sum of reserved and committed memory in the virtual spaces
 500   size_t _reserved_words;
 501   size_t _committed_words;
 502 
 503   // Number of virtual spaces
 504   size_t _virtual_space_count;
 505 
 506   ~VirtualSpaceList();
 507 
 508   VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
 509 
 510   void set_virtual_space_list(VirtualSpaceNode* v) {
 511     _virtual_space_list = v;
 512   }
 513   void set_current_virtual_space(VirtualSpaceNode* v) {
 514     _current_virtual_space = v;
 515   }
 516 
 517   void link_vs(VirtualSpaceNode* new_entry);
 518 
 519   // Get another virtual space and add it to the list.  This
 520   // is typically prompted by a failed attempt to allocate a chunk
 521   // and is typically followed by the allocation of a chunk.
 522   bool create_new_virtual_space(size_t vs_word_size);
 523 
 524   // Chunk up the unused committed space in the current
 525   // virtual space and add the chunks to the free list.
 526   void retire_current_virtual_space();
 527 
 528  public:
 529   VirtualSpaceList(size_t word_size);
 530   VirtualSpaceList(ReservedSpace rs);
 531 
 532   size_t free_bytes();
 533 
 534   Metachunk* get_new_chunk(size_t word_size,
 535                            size_t grow_chunks_by_words,
 536                            size_t medium_chunk_bunch);
 537 
 538   bool expand_node_by(VirtualSpaceNode* node,
 539                       size_t min_words,
 540                       size_t preferred_words);
 541 
 542   bool expand_by(size_t min_words,
 543                  size_t preferred_words);
 544 
 545   VirtualSpaceNode* current_virtual_space() {
 546     return _current_virtual_space;
 547   }
 548 
 549   bool is_class() const { return _is_class; }
 550 
 551   bool initialization_succeeded() { return _virtual_space_list != NULL; }
 552 
 553   size_t reserved_words()  { return _reserved_words; }
 554   size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
 555   size_t committed_words() { return _committed_words; }
 556   size_t committed_bytes() { return committed_words() * BytesPerWord; }
 557 
 558   void inc_reserved_words(size_t v);
 559   void dec_reserved_words(size_t v);
 560   void inc_committed_words(size_t v);
 561   void dec_committed_words(size_t v);
 562   void inc_virtual_space_count();
 563   void dec_virtual_space_count();
 564 
 565   bool contains(const void* ptr);
 566 
 567   // Unlink empty VirtualSpaceNodes and free it.
 568   void purge(ChunkManager* chunk_manager);
 569 
 570   void print_on(outputStream* st) const;
 571 
 572   class VirtualSpaceListIterator : public StackObj {
 573     VirtualSpaceNode* _virtual_spaces;
 574    public:
 575     VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
 576       _virtual_spaces(virtual_spaces) {}
 577 
 578     bool repeat() {
 579       return _virtual_spaces != NULL;
 580     }
 581 
 582     VirtualSpaceNode* get_next() {
 583       VirtualSpaceNode* result = _virtual_spaces;
 584       if (_virtual_spaces != NULL) {
 585         _virtual_spaces = _virtual_spaces->next();
 586       }
 587       return result;
 588     }
 589   };
 590 };
 591 
 592 class Metadebug : AllStatic {
 593   // Debugging support for Metaspaces
 594   static int _allocation_fail_alot_count;
 595 
 596  public:
 597 
 598   static void init_allocation_fail_alot_count();
 599 #ifdef ASSERT
 600   static bool test_metadata_failure();
 601 #endif
 602 };
 603 
 604 int Metadebug::_allocation_fail_alot_count = 0;
 605 
 606 //  SpaceManager - used by Metaspace to handle allocations
 607 class SpaceManager : public CHeapObj<mtClass> {
 608   friend class Metaspace;
 609   friend class Metadebug;
 610 
 611  private:
 612 
 613   // protects allocations
 614   Mutex* const _lock;
 615 
 616   // Type of metadata allocated.
 617   Metaspace::MetadataType _mdtype;
 618 
 619   // List of chunks in use by this SpaceManager.  Allocations
 620   // are done from the current chunk.  The list is used for deallocating
 621   // chunks when the SpaceManager is freed.
 622   Metachunk* _chunks_in_use[NumberOfInUseLists];
 623   Metachunk* _current_chunk;
 624 
 625   // Number of small chunks to allocate to a manager
 626   // If class space manager, small chunks are unlimited
 627   static uint const _small_chunk_limit;
 628 
 629   // Sum of all space in allocated chunks
 630   size_t _allocated_blocks_words;
 631 
 632   // Sum of all allocated chunks
 633   size_t _allocated_chunks_words;
 634   size_t _allocated_chunks_count;
 635 
 636   // Free lists of blocks are per SpaceManager since they
 637   // are assumed to be in chunks in use by the SpaceManager
 638   // and all chunks in use by a SpaceManager are freed when
 639   // the class loader using the SpaceManager is collected.
 640   BlockFreelist _block_freelists;
 641 
 642   // protects virtualspace and chunk expansions
 643   static const char*  _expand_lock_name;
 644   static const int    _expand_lock_rank;
 645   static Mutex* const _expand_lock;
 646 
 647  private:
 648   // Accessors
 649   Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
 650   void set_chunks_in_use(ChunkIndex index, Metachunk* v) {
 651     _chunks_in_use[index] = v;
 652   }
 653 
 654   BlockFreelist* block_freelists() const {
 655     return (BlockFreelist*) &_block_freelists;
 656   }
 657 
 658   Metaspace::MetadataType mdtype() { return _mdtype; }
 659 
 660   VirtualSpaceList* vs_list()   const { return Metaspace::get_space_list(_mdtype); }
 661   ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
 662 
 663   Metachunk* current_chunk() const { return _current_chunk; }
 664   void set_current_chunk(Metachunk* v) {
 665     _current_chunk = v;
 666   }
 667 
 668   Metachunk* find_current_chunk(size_t word_size);
 669 
 670   // Add chunk to the list of chunks in use
 671   void add_chunk(Metachunk* v, bool make_current);
 672   void retire_current_chunk();
 673 
 674   Mutex* lock() const { return _lock; }
 675 
 676   const char* chunk_size_name(ChunkIndex index) const;
 677 
 678  protected:
 679   void initialize();
 680 
 681  public:
 682   SpaceManager(Metaspace::MetadataType mdtype,
 683                Mutex* lock);
 684   ~SpaceManager();
 685 
 686   enum ChunkMultiples {
 687     MediumChunkMultiple = 4
 688   };
 689 
 690   bool is_class() { return _mdtype == Metaspace::ClassType; }
 691 
 692   // Accessors
 693   size_t specialized_chunk_size() { return (size_t) is_class() ? ClassSpecializedChunk : SpecializedChunk; }
 694   size_t small_chunk_size()       { return (size_t) is_class() ? ClassSmallChunk : SmallChunk; }
 695   size_t medium_chunk_size()      { return (size_t) is_class() ? ClassMediumChunk : MediumChunk; }
 696   size_t medium_chunk_bunch()     { return medium_chunk_size() * MediumChunkMultiple; }
 697 
 698   size_t smallest_chunk_size()  { return specialized_chunk_size(); }
 699 
 700   size_t allocated_blocks_words() const { return _allocated_blocks_words; }
 701   size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; }
 702   size_t allocated_chunks_words() const { return _allocated_chunks_words; }
 703   size_t allocated_chunks_count() const { return _allocated_chunks_count; }
 704 
 705   bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
 706 
 707   static Mutex* expand_lock() { return _expand_lock; }
 708 
 709   // Increment the per Metaspace and global running sums for Metachunks
 710   // by the given size.  This is used when a Metachunk to added to
 711   // the in-use list.
 712   void inc_size_metrics(size_t words);
 713   // Increment the per Metaspace and global running sums Metablocks by the given
 714   // size.  This is used when a Metablock is allocated.
 715   void inc_used_metrics(size_t words);
 716   // Delete the portion of the running sums for this SpaceManager. That is,
 717   // the globals running sums for the Metachunks and Metablocks are
 718   // decremented for all the Metachunks in-use by this SpaceManager.
 719   void dec_total_from_size_metrics();
 720 
 721   // Set the sizes for the initial chunks.
 722   void get_initial_chunk_sizes(Metaspace::MetaspaceType type,
 723                                size_t* chunk_word_size,
 724                                size_t* class_chunk_word_size);
 725 
 726   size_t sum_capacity_in_chunks_in_use() const;
 727   size_t sum_used_in_chunks_in_use() const;
 728   size_t sum_free_in_chunks_in_use() const;
 729   size_t sum_waste_in_chunks_in_use() const;
 730   size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
 731 
 732   size_t sum_count_in_chunks_in_use();
 733   size_t sum_count_in_chunks_in_use(ChunkIndex i);
 734 
 735   Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
 736 
 737   // Block allocation and deallocation.
 738   // Allocates a block from the current chunk
 739   MetaWord* allocate(size_t word_size);
 740 
 741   // Helper for allocations
 742   MetaWord* allocate_work(size_t word_size);
 743 
 744   // Returns a block to the per manager freelist
 745   void deallocate(MetaWord* p, size_t word_size);
 746 
 747   // Based on the allocation size and a minimum chunk size,
 748   // returned chunk size (for expanding space for chunk allocation).
 749   size_t calc_chunk_size(size_t allocation_word_size);
 750 
 751   // Called when an allocation from the current chunk fails.
 752   // Gets a new chunk (may require getting a new virtual space),
 753   // and allocates from that chunk.
 754   MetaWord* grow_and_allocate(size_t word_size);
 755 
 756   // Notify memory usage to MemoryService.
 757   void track_metaspace_memory_usage();
 758 
 759   // debugging support.
 760 
 761   void dump(outputStream* const out) const;
 762   void print_on(outputStream* st) const;
 763   void locked_print_chunks_in_use_on(outputStream* st) const;
 764 
 765   void verify();
 766   void verify_chunk_size(Metachunk* chunk);
 767   NOT_PRODUCT(void mangle_freed_chunks();)
 768 #ifdef ASSERT
 769   void verify_allocated_blocks_words();
 770 #endif
 771 
 772   size_t get_raw_word_size(size_t word_size) {
 773     size_t byte_size = word_size * BytesPerWord;
 774 
 775     size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
 776     raw_bytes_size = align_size_up(raw_bytes_size, Metachunk::object_alignment());
 777 
 778     size_t raw_word_size = raw_bytes_size / BytesPerWord;
 779     assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
 780 
 781     return raw_word_size;
 782   }
 783 };
 784 
 785 uint const SpaceManager::_small_chunk_limit = 4;
 786 
 787 const char* SpaceManager::_expand_lock_name =
 788   "SpaceManager chunk allocation lock";
 789 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
 790 Mutex* const SpaceManager::_expand_lock =
 791   new Mutex(SpaceManager::_expand_lock_rank,
 792             SpaceManager::_expand_lock_name,
 793             Mutex::_allow_vm_block_flag);
 794 
 795 void VirtualSpaceNode::inc_container_count() {
 796   assert_lock_strong(SpaceManager::expand_lock());
 797   _container_count++;
 798   assert(_container_count == container_count_slow(),
 799          err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
 800                  " container_count_slow() " SIZE_FORMAT,
 801                  _container_count, container_count_slow()));
 802 }
 803 
 804 void VirtualSpaceNode::dec_container_count() {
 805   assert_lock_strong(SpaceManager::expand_lock());
 806   _container_count--;
 807 }
 808 
 809 #ifdef ASSERT
 810 void VirtualSpaceNode::verify_container_count() {
 811   assert(_container_count == container_count_slow(),
 812     err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
 813             " container_count_slow() " SIZE_FORMAT, _container_count, container_count_slow()));
 814 }
 815 #endif
 816 
 817 // BlockFreelist methods
 818 
 819 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
 820 
 821 BlockFreelist::~BlockFreelist() {
 822   if (_dictionary != NULL) {
 823     if (Verbose && TraceMetadataChunkAllocation) {
 824       _dictionary->print_free_lists(gclog_or_tty);
 825     }
 826     delete _dictionary;
 827   }
 828 }
 829 
 830 void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
 831   Metablock* free_chunk = ::new (p) Metablock(word_size);
 832   if (dictionary() == NULL) {
 833    _dictionary = new BlockTreeDictionary();
 834   }
 835   dictionary()->return_chunk(free_chunk);
 836 }
 837 
 838 MetaWord* BlockFreelist::get_block(size_t word_size) {
 839   if (dictionary() == NULL) {
 840     return NULL;
 841   }
 842 
 843   if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 844     // Dark matter.  Too small for dictionary.
 845     return NULL;
 846   }
 847 
 848   Metablock* free_block =
 849     dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::atLeast);
 850   if (free_block == NULL) {
 851     return NULL;
 852   }
 853 
 854   const size_t block_size = free_block->size();
 855   if (block_size > WasteMultiplier * word_size) {
 856     return_block((MetaWord*)free_block, block_size);
 857     return NULL;
 858   }
 859 
 860   MetaWord* new_block = (MetaWord*)free_block;
 861   assert(block_size >= word_size, "Incorrect size of block from freelist");
 862   const size_t unused = block_size - word_size;
 863   if (unused >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 864     return_block(new_block + word_size, unused);
 865   }
 866 
 867   return new_block;
 868 }
 869 
 870 void BlockFreelist::print_on(outputStream* st) const {
 871   if (dictionary() == NULL) {
 872     return;
 873   }
 874   dictionary()->print_free_lists(st);
 875 }
 876 
 877 // VirtualSpaceNode methods
 878 
 879 VirtualSpaceNode::~VirtualSpaceNode() {
 880   _rs.release();
 881 #ifdef ASSERT
 882   size_t word_size = sizeof(*this) / BytesPerWord;
 883   Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
 884 #endif
 885 }
 886 
 887 size_t VirtualSpaceNode::used_words_in_vs() const {
 888   return pointer_delta(top(), bottom(), sizeof(MetaWord));
 889 }
 890 
 891 // Space committed in the VirtualSpace
 892 size_t VirtualSpaceNode::capacity_words_in_vs() const {
 893   return pointer_delta(end(), bottom(), sizeof(MetaWord));
 894 }
 895 
 896 size_t VirtualSpaceNode::free_words_in_vs() const {
 897   return pointer_delta(end(), top(), sizeof(MetaWord));
 898 }
 899 
 900 // Allocates the chunk from the virtual space only.
 901 // This interface is also used internally for debugging.  Not all
 902 // chunks removed here are necessarily used for allocation.
 903 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
 904   // Bottom of the new chunk
 905   MetaWord* chunk_limit = top();
 906   assert(chunk_limit != NULL, "Not safe to call this method");
 907 
 908   // The virtual spaces are always expanded by the
 909   // commit granularity to enforce the following condition.
 910   // Without this the is_available check will not work correctly.
 911   assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
 912       "The committed memory doesn't match the expanded memory.");
 913 
 914   if (!is_available(chunk_word_size)) {
 915     if (TraceMetadataChunkAllocation) {
 916       gclog_or_tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
 917       // Dump some information about the virtual space that is nearly full
 918       print_on(gclog_or_tty);
 919     }
 920     return NULL;
 921   }
 922 
 923   // Take the space  (bump top on the current virtual space).
 924   inc_top(chunk_word_size);
 925 
 926   // Initialize the chunk
 927   Metachunk* result = ::new (chunk_limit) Metachunk(chunk_word_size, this);
 928   return result;
 929 }
 930 
 931 
 932 // Expand the virtual space (commit more of the reserved space)
 933 bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
 934   size_t min_bytes = min_words * BytesPerWord;
 935   size_t preferred_bytes = preferred_words * BytesPerWord;
 936 
 937   size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
 938 
 939   if (uncommitted < min_bytes) {
 940     return false;
 941   }
 942 
 943   size_t commit = MIN2(preferred_bytes, uncommitted);
 944   bool result = virtual_space()->expand_by(commit, false);
 945 
 946   assert(result, "Failed to commit memory");
 947 
 948   return result;
 949 }
 950 
 951 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
 952   assert_lock_strong(SpaceManager::expand_lock());
 953   Metachunk* result = take_from_committed(chunk_word_size);
 954   if (result != NULL) {
 955     inc_container_count();
 956   }
 957   return result;
 958 }
 959 
 960 bool VirtualSpaceNode::initialize() {
 961 
 962   if (!_rs.is_reserved()) {
 963     return false;
 964   }
 965 
 966   // These are necessary restriction to make sure that the virtual space always
 967   // grows in steps of Metaspace::commit_alignment(). If both base and size are
 968   // aligned only the middle alignment of the VirtualSpace is used.
 969   assert_is_ptr_aligned(_rs.base(), Metaspace::commit_alignment());
 970   assert_is_size_aligned(_rs.size(), Metaspace::commit_alignment());
 971 
 972   // ReservedSpaces marked as special will have the entire memory
 973   // pre-committed. Setting a committed size will make sure that
 974   // committed_size and actual_committed_size agrees.
 975   size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
 976 
 977   bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
 978                                             Metaspace::commit_alignment());
 979   if (result) {
 980     assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
 981         "Checking that the pre-committed memory was registered by the VirtualSpace");
 982 
 983     set_top((MetaWord*)virtual_space()->low());
 984     set_reserved(MemRegion((HeapWord*)_rs.base(),
 985                  (HeapWord*)(_rs.base() + _rs.size())));
 986 
 987     assert(reserved()->start() == (HeapWord*) _rs.base(),
 988       err_msg("Reserved start was not set properly " PTR_FORMAT
 989         " != " PTR_FORMAT, reserved()->start(), _rs.base()));
 990     assert(reserved()->word_size() == _rs.size() / BytesPerWord,
 991       err_msg("Reserved size was not set properly " SIZE_FORMAT
 992         " != " SIZE_FORMAT, reserved()->word_size(),
 993         _rs.size() / BytesPerWord));
 994   }
 995 
 996   return result;
 997 }
 998 
 999 void VirtualSpaceNode::print_on(outputStream* st) const {
1000   size_t used = used_words_in_vs();
1001   size_t capacity = capacity_words_in_vs();
1002   VirtualSpace* vs = virtual_space();
1003   st->print_cr("   space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
1004            "[" PTR_FORMAT ", " PTR_FORMAT ", "
1005            PTR_FORMAT ", " PTR_FORMAT ")",
1006            vs, capacity / K,
1007            capacity == 0 ? 0 : used * 100 / capacity,
1008            bottom(), top(), end(),
1009            vs->high_boundary());
1010 }
1011 
1012 #ifdef ASSERT
1013 void VirtualSpaceNode::mangle() {
1014   size_t word_size = capacity_words_in_vs();
1015   Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
1016 }
1017 #endif // ASSERT
1018 
1019 // VirtualSpaceList methods
1020 // Space allocated from the VirtualSpace
1021 
1022 VirtualSpaceList::~VirtualSpaceList() {
1023   VirtualSpaceListIterator iter(virtual_space_list());
1024   while (iter.repeat()) {
1025     VirtualSpaceNode* vsl = iter.get_next();
1026     delete vsl;
1027   }
1028 }
1029 
1030 void VirtualSpaceList::inc_reserved_words(size_t v) {
1031   assert_lock_strong(SpaceManager::expand_lock());
1032   _reserved_words = _reserved_words + v;
1033 }
1034 void VirtualSpaceList::dec_reserved_words(size_t v) {
1035   assert_lock_strong(SpaceManager::expand_lock());
1036   _reserved_words = _reserved_words - v;
1037 }
1038 
1039 #define assert_committed_below_limit()                             \
1040   assert(MetaspaceAux::committed_bytes() <= MaxMetaspaceSize,      \
1041       err_msg("Too much committed memory. Committed: " SIZE_FORMAT \
1042               " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
1043           MetaspaceAux::committed_bytes(), MaxMetaspaceSize));
1044 
1045 void VirtualSpaceList::inc_committed_words(size_t v) {
1046   assert_lock_strong(SpaceManager::expand_lock());
1047   _committed_words = _committed_words + v;
1048 
1049   assert_committed_below_limit();
1050 }
1051 void VirtualSpaceList::dec_committed_words(size_t v) {
1052   assert_lock_strong(SpaceManager::expand_lock());
1053   _committed_words = _committed_words - v;
1054 
1055   assert_committed_below_limit();
1056 }
1057 
1058 void VirtualSpaceList::inc_virtual_space_count() {
1059   assert_lock_strong(SpaceManager::expand_lock());
1060   _virtual_space_count++;
1061 }
1062 void VirtualSpaceList::dec_virtual_space_count() {
1063   assert_lock_strong(SpaceManager::expand_lock());
1064   _virtual_space_count--;
1065 }
1066 
1067 void ChunkManager::remove_chunk(Metachunk* chunk) {
1068   size_t word_size = chunk->word_size();
1069   ChunkIndex index = list_index(word_size);
1070   if (index != HumongousIndex) {
1071     free_chunks(index)->remove_chunk(chunk);
1072   } else {
1073     humongous_dictionary()->remove_chunk(chunk);
1074   }
1075 
1076   // Chunk is being removed from the chunks free list.
1077   dec_free_chunks_total(chunk->word_size());
1078 }
1079 
1080 // Walk the list of VirtualSpaceNodes and delete
1081 // nodes with a 0 container_count.  Remove Metachunks in
1082 // the node from their respective freelists.
1083 void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
1084   assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work");
1085   assert_lock_strong(SpaceManager::expand_lock());
1086   // Don't use a VirtualSpaceListIterator because this
1087   // list is being changed and a straightforward use of an iterator is not safe.
1088   VirtualSpaceNode* purged_vsl = NULL;
1089   VirtualSpaceNode* prev_vsl = virtual_space_list();
1090   VirtualSpaceNode* next_vsl = prev_vsl;
1091   while (next_vsl != NULL) {
1092     VirtualSpaceNode* vsl = next_vsl;
1093     next_vsl = vsl->next();
1094     // Don't free the current virtual space since it will likely
1095     // be needed soon.
1096     if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
1097       // Unlink it from the list
1098       if (prev_vsl == vsl) {
1099         // This is the case of the current node being the first node.
1100         assert(vsl == virtual_space_list(), "Expected to be the first node");
1101         set_virtual_space_list(vsl->next());
1102       } else {
1103         prev_vsl->set_next(vsl->next());
1104       }
1105 
1106       vsl->purge(chunk_manager);
1107       dec_reserved_words(vsl->reserved_words());
1108       dec_committed_words(vsl->committed_words());
1109       dec_virtual_space_count();
1110       purged_vsl = vsl;
1111       delete vsl;
1112     } else {
1113       prev_vsl = vsl;
1114     }
1115   }
1116 #ifdef ASSERT
1117   if (purged_vsl != NULL) {
1118     // List should be stable enough to use an iterator here.
1119     VirtualSpaceListIterator iter(virtual_space_list());
1120     while (iter.repeat()) {
1121       VirtualSpaceNode* vsl = iter.get_next();
1122       assert(vsl != purged_vsl, "Purge of vsl failed");
1123     }
1124   }
1125 #endif
1126 }
1127 
1128 
1129 // This function looks at the mmap regions in the metaspace without locking.
1130 // The chunks are added with store ordering and not deleted except for at
1131 // unloading time during a safepoint.
1132 bool VirtualSpaceList::contains(const void* ptr) {
1133   // List should be stable enough to use an iterator here because removing virtual
1134   // space nodes is only allowed at a safepoint.
1135   VirtualSpaceListIterator iter(virtual_space_list());
1136   while (iter.repeat()) {
1137     VirtualSpaceNode* vsn = iter.get_next();
1138     if (vsn->contains(ptr)) {
1139       return true;
1140     }
1141   }
1142   return false;
1143 }
1144 
1145 void VirtualSpaceList::retire_current_virtual_space() {
1146   assert_lock_strong(SpaceManager::expand_lock());
1147 
1148   VirtualSpaceNode* vsn = current_virtual_space();
1149 
1150   ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() :
1151                                   Metaspace::chunk_manager_metadata();
1152 
1153   vsn->retire(cm);
1154 }
1155 
1156 void VirtualSpaceNode::retire(ChunkManager* chunk_manager) {
1157   for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) {
1158     ChunkIndex index = (ChunkIndex)i;
1159     size_t chunk_size = chunk_manager->free_chunks(index)->size();
1160 
1161     while (free_words_in_vs() >= chunk_size) {
1162       DEBUG_ONLY(verify_container_count();)
1163       Metachunk* chunk = get_chunk_vs(chunk_size);
1164       assert(chunk != NULL, "allocation should have been successful");
1165 
1166       chunk_manager->return_chunks(index, chunk);
1167       chunk_manager->inc_free_chunks_total(chunk_size);
1168       DEBUG_ONLY(verify_container_count();)
1169     }
1170   }
1171   assert(free_words_in_vs() == 0, "should be empty now");
1172 }
1173 
1174 VirtualSpaceList::VirtualSpaceList(size_t word_size) :
1175                                    _is_class(false),
1176                                    _virtual_space_list(NULL),
1177                                    _current_virtual_space(NULL),
1178                                    _reserved_words(0),
1179                                    _committed_words(0),
1180                                    _virtual_space_count(0) {
1181   MutexLockerEx cl(SpaceManager::expand_lock(),
1182                    Mutex::_no_safepoint_check_flag);
1183   create_new_virtual_space(word_size);
1184 }
1185 
1186 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
1187                                    _is_class(true),
1188                                    _virtual_space_list(NULL),
1189                                    _current_virtual_space(NULL),
1190                                    _reserved_words(0),
1191                                    _committed_words(0),
1192                                    _virtual_space_count(0) {
1193   MutexLockerEx cl(SpaceManager::expand_lock(),
1194                    Mutex::_no_safepoint_check_flag);
1195   VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
1196   bool succeeded = class_entry->initialize();
1197   if (succeeded) {
1198     link_vs(class_entry);
1199   }
1200 }
1201 
1202 size_t VirtualSpaceList::free_bytes() {
1203   return virtual_space_list()->free_words_in_vs() * BytesPerWord;
1204 }
1205 
1206 // Allocate another meta virtual space and add it to the list.
1207 bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
1208   assert_lock_strong(SpaceManager::expand_lock());
1209 
1210   if (is_class()) {
1211     assert(false, "We currently don't support more than one VirtualSpace for"
1212                   " the compressed class space. The initialization of the"
1213                   " CCS uses another code path and should not hit this path.");
1214     return false;
1215   }
1216 
1217   if (vs_word_size == 0) {
1218     assert(false, "vs_word_size should always be at least _reserve_alignment large.");
1219     return false;
1220   }
1221 
1222   // Reserve the space
1223   size_t vs_byte_size = vs_word_size * BytesPerWord;
1224   assert_is_size_aligned(vs_byte_size, Metaspace::reserve_alignment());
1225 
1226   // Allocate the meta virtual space and initialize it.
1227   VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
1228   if (!new_entry->initialize()) {
1229     delete new_entry;
1230     return false;
1231   } else {
1232     assert(new_entry->reserved_words() == vs_word_size,
1233         "Reserved memory size differs from requested memory size");
1234     // ensure lock-free iteration sees fully initialized node
1235     OrderAccess::storestore();
1236     link_vs(new_entry);
1237     return true;
1238   }
1239 }
1240 
1241 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
1242   if (virtual_space_list() == NULL) {
1243       set_virtual_space_list(new_entry);
1244   } else {
1245     current_virtual_space()->set_next(new_entry);
1246   }
1247   set_current_virtual_space(new_entry);
1248   inc_reserved_words(new_entry->reserved_words());
1249   inc_committed_words(new_entry->committed_words());
1250   inc_virtual_space_count();
1251 #ifdef ASSERT
1252   new_entry->mangle();
1253 #endif
1254   if (TraceMetavirtualspaceAllocation && Verbose) {
1255     VirtualSpaceNode* vsl = current_virtual_space();
1256     vsl->print_on(gclog_or_tty);
1257   }
1258 }
1259 
1260 bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
1261                                       size_t min_words,
1262                                       size_t preferred_words) {
1263   size_t before = node->committed_words();
1264 
1265   bool result = node->expand_by(min_words, preferred_words);
1266 
1267   size_t after = node->committed_words();
1268 
1269   // after and before can be the same if the memory was pre-committed.
1270   assert(after >= before, "Inconsistency");
1271   inc_committed_words(after - before);
1272 
1273   return result;
1274 }
1275 
1276 bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
1277   assert_is_size_aligned(min_words,       Metaspace::commit_alignment_words());
1278   assert_is_size_aligned(preferred_words, Metaspace::commit_alignment_words());
1279   assert(min_words <= preferred_words, "Invalid arguments");
1280 
1281   if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
1282     return  false;
1283   }
1284 
1285   size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
1286   if (allowed_expansion_words < min_words) {
1287     return false;
1288   }
1289 
1290   size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
1291 
1292   // Commit more memory from the the current virtual space.
1293   bool vs_expanded = expand_node_by(current_virtual_space(),
1294                                     min_words,
1295                                     max_expansion_words);
1296   if (vs_expanded) {
1297     return true;
1298   }
1299   retire_current_virtual_space();
1300 
1301   // Get another virtual space.
1302   size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
1303   grow_vs_words = align_size_up(grow_vs_words, Metaspace::reserve_alignment_words());
1304 
1305   if (create_new_virtual_space(grow_vs_words)) {
1306     if (current_virtual_space()->is_pre_committed()) {
1307       // The memory was pre-committed, so we are done here.
1308       assert(min_words <= current_virtual_space()->committed_words(),
1309           "The new VirtualSpace was pre-committed, so it"
1310           "should be large enough to fit the alloc request.");
1311       return true;
1312     }
1313 
1314     return expand_node_by(current_virtual_space(),
1315                           min_words,
1316                           max_expansion_words);
1317   }
1318 
1319   return false;
1320 }
1321 
1322 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
1323                                            size_t grow_chunks_by_words,
1324                                            size_t medium_chunk_bunch) {
1325 
1326   // Allocate a chunk out of the current virtual space.
1327   Metachunk* next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1328 
1329   if (next != NULL) {
1330     return next;
1331   }
1332 
1333   // The expand amount is currently only determined by the requested sizes
1334   // and not how much committed memory is left in the current virtual space.
1335 
1336   size_t min_word_size       = align_size_up(grow_chunks_by_words, Metaspace::commit_alignment_words());
1337   size_t preferred_word_size = align_size_up(medium_chunk_bunch,   Metaspace::commit_alignment_words());
1338   if (min_word_size >= preferred_word_size) {
1339     // Can happen when humongous chunks are allocated.
1340     preferred_word_size = min_word_size;
1341   }
1342 
1343   bool expanded = expand_by(min_word_size, preferred_word_size);
1344   if (expanded) {
1345     next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1346     assert(next != NULL, "The allocation was expected to succeed after the expansion");
1347   }
1348 
1349    return next;
1350 }
1351 
1352 void VirtualSpaceList::print_on(outputStream* st) const {
1353   if (TraceMetadataChunkAllocation && Verbose) {
1354     VirtualSpaceListIterator iter(virtual_space_list());
1355     while (iter.repeat()) {
1356       VirtualSpaceNode* node = iter.get_next();
1357       node->print_on(st);
1358     }
1359   }
1360 }
1361 
1362 // MetaspaceGC methods
1363 
1364 // VM_CollectForMetadataAllocation is the vm operation used to GC.
1365 // Within the VM operation after the GC the attempt to allocate the metadata
1366 // should succeed.  If the GC did not free enough space for the metaspace
1367 // allocation, the HWM is increased so that another virtualspace will be
1368 // allocated for the metadata.  With perm gen the increase in the perm
1369 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion.  The
1370 // metaspace policy uses those as the small and large steps for the HWM.
1371 //
1372 // After the GC the compute_new_size() for MetaspaceGC is called to
1373 // resize the capacity of the metaspaces.  The current implementation
1374 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
1375 // to resize the Java heap by some GC's.  New flags can be implemented
1376 // if really needed.  MinMetaspaceFreeRatio is used to calculate how much
1377 // free space is desirable in the metaspace capacity to decide how much
1378 // to increase the HWM.  MaxMetaspaceFreeRatio is used to decide how much
1379 // free space is desirable in the metaspace capacity before decreasing
1380 // the HWM.
1381 
1382 // Calculate the amount to increase the high water mark (HWM).
1383 // Increase by a minimum amount (MinMetaspaceExpansion) so that
1384 // another expansion is not requested too soon.  If that is not
1385 // enough to satisfy the allocation, increase by MaxMetaspaceExpansion.
1386 // If that is still not enough, expand by the size of the allocation
1387 // plus some.
1388 size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) {
1389   size_t min_delta = MinMetaspaceExpansion;
1390   size_t max_delta = MaxMetaspaceExpansion;
1391   size_t delta = align_size_up(bytes, Metaspace::commit_alignment());
1392 
1393   if (delta <= min_delta) {
1394     delta = min_delta;
1395   } else if (delta <= max_delta) {
1396     // Don't want to hit the high water mark on the next
1397     // allocation so make the delta greater than just enough
1398     // for this allocation.
1399     delta = max_delta;
1400   } else {
1401     // This allocation is large but the next ones are probably not
1402     // so increase by the minimum.
1403     delta = delta + min_delta;
1404   }
1405 
1406   assert_is_size_aligned(delta, Metaspace::commit_alignment());
1407 
1408   return delta;
1409 }
1410 
1411 size_t MetaspaceGC::capacity_until_GC() {
1412   size_t value = (size_t)OrderAccess::load_ptr_acquire(&_capacity_until_GC);
1413   assert(value >= MetaspaceSize, "Not initialied properly?");
1414   return value;
1415 }
1416 
1417 bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) {
1418   assert_is_size_aligned(v, Metaspace::commit_alignment());
1419 
1420   size_t capacity_until_GC = (size_t) _capacity_until_GC;
1421   size_t new_value = capacity_until_GC + v;
1422 
1423   if (new_value < capacity_until_GC) {
1424     // The addition wrapped around, set new_value to aligned max value.
1425     new_value = align_size_down(max_uintx, Metaspace::commit_alignment());
1426   }
1427 
1428   intptr_t expected = (intptr_t) capacity_until_GC;
1429   intptr_t actual = Atomic::cmpxchg_ptr((intptr_t) new_value, &_capacity_until_GC, expected);
1430 
1431   if (expected != actual) {
1432     return false;
1433   }
1434 
1435   if (new_cap_until_GC != NULL) {
1436     *new_cap_until_GC = new_value;
1437   }
1438   if (old_cap_until_GC != NULL) {
1439     *old_cap_until_GC = capacity_until_GC;
1440   }
1441   return true;
1442 }
1443 
1444 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
1445   assert_is_size_aligned(v, Metaspace::commit_alignment());
1446 
1447   return (size_t)Atomic::add_ptr(-(intptr_t)v, &_capacity_until_GC);
1448 }
1449 
1450 void MetaspaceGC::initialize() {
1451   // Set the high-water mark to MaxMetapaceSize during VM initializaton since
1452   // we can't do a GC during initialization.
1453   _capacity_until_GC = MaxMetaspaceSize;
1454 }
1455 
1456 void MetaspaceGC::post_initialize() {
1457   // Reset the high-water mark once the VM initialization is done.
1458   _capacity_until_GC = MAX2(MetaspaceAux::committed_bytes(), MetaspaceSize);
1459 }
1460 
1461 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
1462   // Check if the compressed class space is full.
1463   if (is_class && Metaspace::using_class_space()) {
1464     size_t class_committed = MetaspaceAux::committed_bytes(Metaspace::ClassType);
1465     if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
1466       return false;
1467     }
1468   }
1469 
1470   // Check if the user has imposed a limit on the metaspace memory.
1471   size_t committed_bytes = MetaspaceAux::committed_bytes();
1472   if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
1473     return false;
1474   }
1475 
1476   return true;
1477 }
1478 
1479 size_t MetaspaceGC::allowed_expansion() {
1480   size_t committed_bytes = MetaspaceAux::committed_bytes();
1481   size_t capacity_until_gc = capacity_until_GC();
1482 
1483   assert(capacity_until_gc >= committed_bytes,
1484         err_msg("capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT,
1485                 capacity_until_gc, committed_bytes));
1486 
1487   size_t left_until_max  = MaxMetaspaceSize - committed_bytes;
1488   size_t left_until_GC = capacity_until_gc - committed_bytes;
1489   size_t left_to_commit = MIN2(left_until_GC, left_until_max);
1490 
1491   return left_to_commit / BytesPerWord;
1492 }
1493 
1494 void MetaspaceGC::compute_new_size() {
1495   assert(_shrink_factor <= 100, "invalid shrink factor");
1496   uint current_shrink_factor = _shrink_factor;
1497   _shrink_factor = 0;
1498 
1499   // Using committed_bytes() for used_after_gc is an overestimation, since the
1500   // chunk free lists are included in committed_bytes() and the memory in an
1501   // un-fragmented chunk free list is available for future allocations.
1502   // However, if the chunk free lists becomes fragmented, then the memory may
1503   // not be available for future allocations and the memory is therefore "in use".
1504   // Including the chunk free lists in the definition of "in use" is therefore
1505   // necessary. Not including the chunk free lists can cause capacity_until_GC to
1506   // shrink below committed_bytes() and this has caused serious bugs in the past.
1507   const size_t used_after_gc = MetaspaceAux::committed_bytes();
1508   const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
1509 
1510   const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
1511   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
1512 
1513   const double min_tmp = used_after_gc / maximum_used_percentage;
1514   size_t minimum_desired_capacity =
1515     (size_t)MIN2(min_tmp, double(max_uintx));
1516   // Don't shrink less than the initial generation size
1517   minimum_desired_capacity = MAX2(minimum_desired_capacity,
1518                                   MetaspaceSize);
1519 
1520   if (PrintGCDetails && Verbose) {
1521     gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
1522     gclog_or_tty->print_cr("  "
1523                   "  minimum_free_percentage: %6.2f"
1524                   "  maximum_used_percentage: %6.2f",
1525                   minimum_free_percentage,
1526                   maximum_used_percentage);
1527     gclog_or_tty->print_cr("  "
1528                   "   used_after_gc       : %6.1fKB",
1529                   used_after_gc / (double) K);
1530   }
1531 
1532 
1533   size_t shrink_bytes = 0;
1534   if (capacity_until_GC < minimum_desired_capacity) {
1535     // If we have less capacity below the metaspace HWM, then
1536     // increment the HWM.
1537     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
1538     expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
1539     // Don't expand unless it's significant
1540     if (expand_bytes >= MinMetaspaceExpansion) {
1541       size_t new_capacity_until_GC = 0;
1542       bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC);
1543       assert(succeeded, "Should always succesfully increment HWM when at safepoint");
1544 
1545       Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1546                                                new_capacity_until_GC,
1547                                                MetaspaceGCThresholdUpdater::ComputeNewSize);
1548       if (PrintGCDetails && Verbose) {
1549         gclog_or_tty->print_cr("    expanding:"
1550                       "  minimum_desired_capacity: %6.1fKB"
1551                       "  expand_bytes: %6.1fKB"
1552                       "  MinMetaspaceExpansion: %6.1fKB"
1553                       "  new metaspace HWM:  %6.1fKB",
1554                       minimum_desired_capacity / (double) K,
1555                       expand_bytes / (double) K,
1556                       MinMetaspaceExpansion / (double) K,
1557                       new_capacity_until_GC / (double) K);
1558       }
1559     }
1560     return;
1561   }
1562 
1563   // No expansion, now see if we want to shrink
1564   // We would never want to shrink more than this
1565   size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity;
1566   assert(max_shrink_bytes >= 0, err_msg("max_shrink_bytes " SIZE_FORMAT,
1567     max_shrink_bytes));
1568 
1569   // Should shrinking be considered?
1570   if (MaxMetaspaceFreeRatio < 100) {
1571     const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0;
1572     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
1573     const double max_tmp = used_after_gc / minimum_used_percentage;
1574     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
1575     maximum_desired_capacity = MAX2(maximum_desired_capacity,
1576                                     MetaspaceSize);
1577     if (PrintGCDetails && Verbose) {
1578       gclog_or_tty->print_cr("  "
1579                              "  maximum_free_percentage: %6.2f"
1580                              "  minimum_used_percentage: %6.2f",
1581                              maximum_free_percentage,
1582                              minimum_used_percentage);
1583       gclog_or_tty->print_cr("  "
1584                              "  minimum_desired_capacity: %6.1fKB"
1585                              "  maximum_desired_capacity: %6.1fKB",
1586                              minimum_desired_capacity / (double) K,
1587                              maximum_desired_capacity / (double) K);
1588     }
1589 
1590     assert(minimum_desired_capacity <= maximum_desired_capacity,
1591            "sanity check");
1592 
1593     if (capacity_until_GC > maximum_desired_capacity) {
1594       // Capacity too large, compute shrinking size
1595       shrink_bytes = capacity_until_GC - maximum_desired_capacity;
1596       // We don't want shrink all the way back to initSize if people call
1597       // System.gc(), because some programs do that between "phases" and then
1598       // we'd just have to grow the heap up again for the next phase.  So we
1599       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
1600       // on the third call, and 100% by the fourth call.  But if we recompute
1601       // size without shrinking, it goes back to 0%.
1602       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
1603 
1604       shrink_bytes = align_size_down(shrink_bytes, Metaspace::commit_alignment());
1605 
1606       assert(shrink_bytes <= max_shrink_bytes,
1607         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
1608           shrink_bytes, max_shrink_bytes));
1609       if (current_shrink_factor == 0) {
1610         _shrink_factor = 10;
1611       } else {
1612         _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
1613       }
1614       if (PrintGCDetails && Verbose) {
1615         gclog_or_tty->print_cr("  "
1616                       "  shrinking:"
1617                       "  initSize: %.1fK"
1618                       "  maximum_desired_capacity: %.1fK",
1619                       MetaspaceSize / (double) K,
1620                       maximum_desired_capacity / (double) K);
1621         gclog_or_tty->print_cr("  "
1622                       "  shrink_bytes: %.1fK"
1623                       "  current_shrink_factor: %d"
1624                       "  new shrink factor: %d"
1625                       "  MinMetaspaceExpansion: %.1fK",
1626                       shrink_bytes / (double) K,
1627                       current_shrink_factor,
1628                       _shrink_factor,
1629                       MinMetaspaceExpansion / (double) K);
1630       }
1631     }
1632   }
1633 
1634   // Don't shrink unless it's significant
1635   if (shrink_bytes >= MinMetaspaceExpansion &&
1636       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
1637     size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
1638     Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1639                                              new_capacity_until_GC,
1640                                              MetaspaceGCThresholdUpdater::ComputeNewSize);
1641   }
1642 }
1643 
1644 // Metadebug methods
1645 
1646 void Metadebug::init_allocation_fail_alot_count() {
1647   if (MetadataAllocationFailALot) {
1648     _allocation_fail_alot_count =
1649       1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
1650   }
1651 }
1652 
1653 #ifdef ASSERT
1654 bool Metadebug::test_metadata_failure() {
1655   if (MetadataAllocationFailALot &&
1656       Threads::is_vm_complete()) {
1657     if (_allocation_fail_alot_count > 0) {
1658       _allocation_fail_alot_count--;
1659     } else {
1660       if (TraceMetadataChunkAllocation && Verbose) {
1661         gclog_or_tty->print_cr("Metadata allocation failing for "
1662                                "MetadataAllocationFailALot");
1663       }
1664       init_allocation_fail_alot_count();
1665       return true;
1666     }
1667   }
1668   return false;
1669 }
1670 #endif
1671 
1672 // ChunkManager methods
1673 
1674 size_t ChunkManager::free_chunks_total_words() {
1675   return _free_chunks_total;
1676 }
1677 
1678 size_t ChunkManager::free_chunks_total_bytes() {
1679   return free_chunks_total_words() * BytesPerWord;
1680 }
1681 
1682 size_t ChunkManager::free_chunks_count() {
1683 #ifdef ASSERT
1684   if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1685     MutexLockerEx cl(SpaceManager::expand_lock(),
1686                      Mutex::_no_safepoint_check_flag);
1687     // This lock is only needed in debug because the verification
1688     // of the _free_chunks_totals walks the list of free chunks
1689     slow_locked_verify_free_chunks_count();
1690   }
1691 #endif
1692   return _free_chunks_count;
1693 }
1694 
1695 void ChunkManager::locked_verify_free_chunks_total() {
1696   assert_lock_strong(SpaceManager::expand_lock());
1697   assert(sum_free_chunks() == _free_chunks_total,
1698     err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
1699            " same as sum " SIZE_FORMAT, _free_chunks_total,
1700            sum_free_chunks()));
1701 }
1702 
1703 void ChunkManager::verify_free_chunks_total() {
1704   MutexLockerEx cl(SpaceManager::expand_lock(),
1705                      Mutex::_no_safepoint_check_flag);
1706   locked_verify_free_chunks_total();
1707 }
1708 
1709 void ChunkManager::locked_verify_free_chunks_count() {
1710   assert_lock_strong(SpaceManager::expand_lock());
1711   assert(sum_free_chunks_count() == _free_chunks_count,
1712     err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
1713            " same as sum " SIZE_FORMAT, _free_chunks_count,
1714            sum_free_chunks_count()));
1715 }
1716 
1717 void ChunkManager::verify_free_chunks_count() {
1718 #ifdef ASSERT
1719   MutexLockerEx cl(SpaceManager::expand_lock(),
1720                      Mutex::_no_safepoint_check_flag);
1721   locked_verify_free_chunks_count();
1722 #endif
1723 }
1724 
1725 void ChunkManager::verify() {
1726   MutexLockerEx cl(SpaceManager::expand_lock(),
1727                      Mutex::_no_safepoint_check_flag);
1728   locked_verify();
1729 }
1730 
1731 void ChunkManager::locked_verify() {
1732   locked_verify_free_chunks_count();
1733   locked_verify_free_chunks_total();
1734 }
1735 
1736 void ChunkManager::locked_print_free_chunks(outputStream* st) {
1737   assert_lock_strong(SpaceManager::expand_lock());
1738   st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1739                 _free_chunks_total, _free_chunks_count);
1740 }
1741 
1742 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
1743   assert_lock_strong(SpaceManager::expand_lock());
1744   st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1745                 sum_free_chunks(), sum_free_chunks_count());
1746 }
1747 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
1748   return &_free_chunks[index];
1749 }
1750 
1751 // These methods that sum the free chunk lists are used in printing
1752 // methods that are used in product builds.
1753 size_t ChunkManager::sum_free_chunks() {
1754   assert_lock_strong(SpaceManager::expand_lock());
1755   size_t result = 0;
1756   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1757     ChunkList* list = free_chunks(i);
1758 
1759     if (list == NULL) {
1760       continue;
1761     }
1762 
1763     result = result + list->count() * list->size();
1764   }
1765   result = result + humongous_dictionary()->total_size();
1766   return result;
1767 }
1768 
1769 size_t ChunkManager::sum_free_chunks_count() {
1770   assert_lock_strong(SpaceManager::expand_lock());
1771   size_t count = 0;
1772   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1773     ChunkList* list = free_chunks(i);
1774     if (list == NULL) {
1775       continue;
1776     }
1777     count = count + list->count();
1778   }
1779   count = count + humongous_dictionary()->total_free_blocks();
1780   return count;
1781 }
1782 
1783 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
1784   ChunkIndex index = list_index(word_size);
1785   assert(index < HumongousIndex, "No humongous list");
1786   return free_chunks(index);
1787 }
1788 
1789 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
1790   assert_lock_strong(SpaceManager::expand_lock());
1791 
1792   slow_locked_verify();
1793 
1794   Metachunk* chunk = NULL;
1795   if (list_index(word_size) != HumongousIndex) {
1796     ChunkList* free_list = find_free_chunks_list(word_size);
1797     assert(free_list != NULL, "Sanity check");
1798 
1799     chunk = free_list->head();
1800 
1801     if (chunk == NULL) {
1802       return NULL;
1803     }
1804 
1805     // Remove the chunk as the head of the list.
1806     free_list->remove_chunk(chunk);
1807 
1808     if (TraceMetadataChunkAllocation && Verbose) {
1809       gclog_or_tty->print_cr("ChunkManager::free_chunks_get: free_list "
1810                              PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
1811                              free_list, chunk, chunk->word_size());
1812     }
1813   } else {
1814     chunk = humongous_dictionary()->get_chunk(
1815       word_size,
1816       FreeBlockDictionary<Metachunk>::atLeast);
1817 
1818     if (chunk == NULL) {
1819       return NULL;
1820     }
1821 
1822     if (TraceMetadataHumongousAllocation) {
1823       size_t waste = chunk->word_size() - word_size;
1824       gclog_or_tty->print_cr("Free list allocate humongous chunk size "
1825                              SIZE_FORMAT " for requested size " SIZE_FORMAT
1826                              " waste " SIZE_FORMAT,
1827                              chunk->word_size(), word_size, waste);
1828     }
1829   }
1830 
1831   // Chunk is being removed from the chunks free list.
1832   dec_free_chunks_total(chunk->word_size());
1833 
1834   // Remove it from the links to this freelist
1835   chunk->set_next(NULL);
1836   chunk->set_prev(NULL);
1837 #ifdef ASSERT
1838   // Chunk is no longer on any freelist. Setting to false make container_count_slow()
1839   // work.
1840   chunk->set_is_tagged_free(false);
1841 #endif
1842   chunk->container()->inc_container_count();
1843 
1844   slow_locked_verify();
1845   return chunk;
1846 }
1847 
1848 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
1849   assert_lock_strong(SpaceManager::expand_lock());
1850   slow_locked_verify();
1851 
1852   // Take from the beginning of the list
1853   Metachunk* chunk = free_chunks_get(word_size);
1854   if (chunk == NULL) {
1855     return NULL;
1856   }
1857 
1858   assert((word_size <= chunk->word_size()) ||
1859          list_index(chunk->word_size() == HumongousIndex),
1860          "Non-humongous variable sized chunk");
1861   if (TraceMetadataChunkAllocation) {
1862     size_t list_count;
1863     if (list_index(word_size) < HumongousIndex) {
1864       ChunkList* list = find_free_chunks_list(word_size);
1865       list_count = list->count();
1866     } else {
1867       list_count = humongous_dictionary()->total_count();
1868     }
1869     gclog_or_tty->print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk "
1870                         PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
1871                         this, chunk, chunk->word_size(), list_count);
1872     locked_print_free_chunks(gclog_or_tty);
1873   }
1874 
1875   return chunk;
1876 }
1877 
1878 void ChunkManager::print_on(outputStream* out) const {
1879   if (PrintFLSStatistics != 0) {
1880     const_cast<ChunkManager *>(this)->humongous_dictionary()->report_statistics();
1881   }
1882 }
1883 
1884 // SpaceManager methods
1885 
1886 void SpaceManager::get_initial_chunk_sizes(Metaspace::MetaspaceType type,
1887                                            size_t* chunk_word_size,
1888                                            size_t* class_chunk_word_size) {
1889   switch (type) {
1890   case Metaspace::BootMetaspaceType:
1891     *chunk_word_size = Metaspace::first_chunk_word_size();
1892     *class_chunk_word_size = Metaspace::first_class_chunk_word_size();
1893     break;
1894   case Metaspace::ROMetaspaceType:
1895     *chunk_word_size = SharedReadOnlySize / wordSize;
1896     *class_chunk_word_size = ClassSpecializedChunk;
1897     break;
1898   case Metaspace::ReadWriteMetaspaceType:
1899     *chunk_word_size = SharedReadWriteSize / wordSize;
1900     *class_chunk_word_size = ClassSpecializedChunk;
1901     break;
1902   case Metaspace::AnonymousMetaspaceType:
1903   case Metaspace::ReflectionMetaspaceType:
1904     *chunk_word_size = SpecializedChunk;
1905     *class_chunk_word_size = ClassSpecializedChunk;
1906     break;
1907   default:
1908     *chunk_word_size = SmallChunk;
1909     *class_chunk_word_size = ClassSmallChunk;
1910     break;
1911   }
1912   assert(*chunk_word_size != 0 && *class_chunk_word_size != 0,
1913     err_msg("Initial chunks sizes bad: data  " SIZE_FORMAT
1914             " class " SIZE_FORMAT,
1915             *chunk_word_size, *class_chunk_word_size));
1916 }
1917 
1918 size_t SpaceManager::sum_free_in_chunks_in_use() const {
1919   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1920   size_t free = 0;
1921   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1922     Metachunk* chunk = chunks_in_use(i);
1923     while (chunk != NULL) {
1924       free += chunk->free_word_size();
1925       chunk = chunk->next();
1926     }
1927   }
1928   return free;
1929 }
1930 
1931 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
1932   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1933   size_t result = 0;
1934   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1935    result += sum_waste_in_chunks_in_use(i);
1936   }
1937 
1938   return result;
1939 }
1940 
1941 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
1942   size_t result = 0;
1943   Metachunk* chunk = chunks_in_use(index);
1944   // Count the free space in all the chunk but not the
1945   // current chunk from which allocations are still being done.
1946   while (chunk != NULL) {
1947     if (chunk != current_chunk()) {
1948       result += chunk->free_word_size();
1949     }
1950     chunk = chunk->next();
1951   }
1952   return result;
1953 }
1954 
1955 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
1956   // For CMS use "allocated_chunks_words()" which does not need the
1957   // Metaspace lock.  For the other collectors sum over the
1958   // lists.  Use both methods as a check that "allocated_chunks_words()"
1959   // is correct.  That is, sum_capacity_in_chunks() is too expensive
1960   // to use in the product and allocated_chunks_words() should be used
1961   // but allow for  checking that allocated_chunks_words() returns the same
1962   // value as sum_capacity_in_chunks_in_use() which is the definitive
1963   // answer.
1964   if (UseConcMarkSweepGC) {
1965     return allocated_chunks_words();
1966   } else {
1967     MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1968     size_t sum = 0;
1969     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1970       Metachunk* chunk = chunks_in_use(i);
1971       while (chunk != NULL) {
1972         sum += chunk->word_size();
1973         chunk = chunk->next();
1974       }
1975     }
1976   return sum;
1977   }
1978 }
1979 
1980 size_t SpaceManager::sum_count_in_chunks_in_use() {
1981   size_t count = 0;
1982   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1983     count = count + sum_count_in_chunks_in_use(i);
1984   }
1985 
1986   return count;
1987 }
1988 
1989 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
1990   size_t count = 0;
1991   Metachunk* chunk = chunks_in_use(i);
1992   while (chunk != NULL) {
1993     count++;
1994     chunk = chunk->next();
1995   }
1996   return count;
1997 }
1998 
1999 
2000 size_t SpaceManager::sum_used_in_chunks_in_use() const {
2001   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2002   size_t used = 0;
2003   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2004     Metachunk* chunk = chunks_in_use(i);
2005     while (chunk != NULL) {
2006       used += chunk->used_word_size();
2007       chunk = chunk->next();
2008     }
2009   }
2010   return used;
2011 }
2012 
2013 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
2014 
2015   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2016     Metachunk* chunk = chunks_in_use(i);
2017     st->print("SpaceManager: %s " PTR_FORMAT,
2018                  chunk_size_name(i), chunk);
2019     if (chunk != NULL) {
2020       st->print_cr(" free " SIZE_FORMAT,
2021                    chunk->free_word_size());
2022     } else {
2023       st->cr();
2024     }
2025   }
2026 
2027   chunk_manager()->locked_print_free_chunks(st);
2028   chunk_manager()->locked_print_sum_free_chunks(st);
2029 }
2030 
2031 size_t SpaceManager::calc_chunk_size(size_t word_size) {
2032 
2033   // Decide between a small chunk and a medium chunk.  Up to
2034   // _small_chunk_limit small chunks can be allocated but
2035   // once a medium chunk has been allocated, no more small
2036   // chunks will be allocated.
2037   size_t chunk_word_size;
2038   if (chunks_in_use(MediumIndex) == NULL &&
2039       sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) {
2040     chunk_word_size = (size_t) small_chunk_size();
2041     if (word_size + Metachunk::overhead() > small_chunk_size()) {
2042       chunk_word_size = medium_chunk_size();
2043     }
2044   } else {
2045     chunk_word_size = medium_chunk_size();
2046   }
2047 
2048   // Might still need a humongous chunk.  Enforce
2049   // humongous allocations sizes to be aligned up to
2050   // the smallest chunk size.
2051   size_t if_humongous_sized_chunk =
2052     align_size_up(word_size + Metachunk::overhead(),
2053                   smallest_chunk_size());
2054   chunk_word_size =
2055     MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
2056 
2057   assert(!SpaceManager::is_humongous(word_size) ||
2058          chunk_word_size == if_humongous_sized_chunk,
2059          err_msg("Size calculation is wrong, word_size " SIZE_FORMAT
2060                  " chunk_word_size " SIZE_FORMAT,
2061                  word_size, chunk_word_size));
2062   if (TraceMetadataHumongousAllocation &&
2063       SpaceManager::is_humongous(word_size)) {
2064     gclog_or_tty->print_cr("Metadata humongous allocation:");
2065     gclog_or_tty->print_cr("  word_size " PTR_FORMAT, word_size);
2066     gclog_or_tty->print_cr("  chunk_word_size " PTR_FORMAT,
2067                            chunk_word_size);
2068     gclog_or_tty->print_cr("    chunk overhead " PTR_FORMAT,
2069                            Metachunk::overhead());
2070   }
2071   return chunk_word_size;
2072 }
2073 
2074 void SpaceManager::track_metaspace_memory_usage() {
2075   if (is_init_completed()) {
2076     if (is_class()) {
2077       MemoryService::track_compressed_class_memory_usage();
2078     }
2079     MemoryService::track_metaspace_memory_usage();
2080   }
2081 }
2082 
2083 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
2084   assert(vs_list()->current_virtual_space() != NULL,
2085          "Should have been set");
2086   assert(current_chunk() == NULL ||
2087          current_chunk()->allocate(word_size) == NULL,
2088          "Don't need to expand");
2089   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2090 
2091   if (TraceMetadataChunkAllocation && Verbose) {
2092     size_t words_left = 0;
2093     size_t words_used = 0;
2094     if (current_chunk() != NULL) {
2095       words_left = current_chunk()->free_word_size();
2096       words_used = current_chunk()->used_word_size();
2097     }
2098     gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
2099                            " words " SIZE_FORMAT " words used " SIZE_FORMAT
2100                            " words left",
2101                             word_size, words_used, words_left);
2102   }
2103 
2104   // Get another chunk out of the virtual space
2105   size_t grow_chunks_by_words = calc_chunk_size(word_size);
2106   Metachunk* next = get_new_chunk(word_size, grow_chunks_by_words);
2107 
2108   MetaWord* mem = NULL;
2109 
2110   // If a chunk was available, add it to the in-use chunk list
2111   // and do an allocation from it.
2112   if (next != NULL) {
2113     // Add to this manager's list of chunks in use.
2114     add_chunk(next, false);
2115     mem = next->allocate(word_size);
2116   }
2117 
2118   // Track metaspace memory usage statistic.
2119   track_metaspace_memory_usage();
2120 
2121   return mem;
2122 }
2123 
2124 void SpaceManager::print_on(outputStream* st) const {
2125 
2126   for (ChunkIndex i = ZeroIndex;
2127        i < NumberOfInUseLists ;
2128        i = next_chunk_index(i) ) {
2129     st->print_cr("  chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
2130                  chunks_in_use(i),
2131                  chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
2132   }
2133   st->print_cr("    waste:  Small " SIZE_FORMAT " Medium " SIZE_FORMAT
2134                " Humongous " SIZE_FORMAT,
2135                sum_waste_in_chunks_in_use(SmallIndex),
2136                sum_waste_in_chunks_in_use(MediumIndex),
2137                sum_waste_in_chunks_in_use(HumongousIndex));
2138   // block free lists
2139   if (block_freelists() != NULL) {
2140     st->print_cr("total in block free lists " SIZE_FORMAT,
2141       block_freelists()->total_size());
2142   }
2143 }
2144 
2145 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
2146                            Mutex* lock) :
2147   _mdtype(mdtype),
2148   _allocated_blocks_words(0),
2149   _allocated_chunks_words(0),
2150   _allocated_chunks_count(0),
2151   _lock(lock)
2152 {
2153   initialize();
2154 }
2155 
2156 void SpaceManager::inc_size_metrics(size_t words) {
2157   assert_lock_strong(SpaceManager::expand_lock());
2158   // Total of allocated Metachunks and allocated Metachunks count
2159   // for each SpaceManager
2160   _allocated_chunks_words = _allocated_chunks_words + words;
2161   _allocated_chunks_count++;
2162   // Global total of capacity in allocated Metachunks
2163   MetaspaceAux::inc_capacity(mdtype(), words);
2164   // Global total of allocated Metablocks.
2165   // used_words_slow() includes the overhead in each
2166   // Metachunk so include it in the used when the
2167   // Metachunk is first added (so only added once per
2168   // Metachunk).
2169   MetaspaceAux::inc_used(mdtype(), Metachunk::overhead());
2170 }
2171 
2172 void SpaceManager::inc_used_metrics(size_t words) {
2173   // Add to the per SpaceManager total
2174   Atomic::add_ptr(words, &_allocated_blocks_words);
2175   // Add to the global total
2176   MetaspaceAux::inc_used(mdtype(), words);
2177 }
2178 
2179 void SpaceManager::dec_total_from_size_metrics() {
2180   MetaspaceAux::dec_capacity(mdtype(), allocated_chunks_words());
2181   MetaspaceAux::dec_used(mdtype(), allocated_blocks_words());
2182   // Also deduct the overhead per Metachunk
2183   MetaspaceAux::dec_used(mdtype(), allocated_chunks_count() * Metachunk::overhead());
2184 }
2185 
2186 void SpaceManager::initialize() {
2187   Metadebug::init_allocation_fail_alot_count();
2188   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2189     _chunks_in_use[i] = NULL;
2190   }
2191   _current_chunk = NULL;
2192   if (TraceMetadataChunkAllocation && Verbose) {
2193     gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
2194   }
2195 }
2196 
2197 void ChunkManager::return_chunks(ChunkIndex index, Metachunk* chunks) {
2198   if (chunks == NULL) {
2199     return;
2200   }
2201   ChunkList* list = free_chunks(index);
2202   assert(list->size() == chunks->word_size(), "Mismatch in chunk sizes");
2203   assert_lock_strong(SpaceManager::expand_lock());
2204   Metachunk* cur = chunks;
2205 
2206   // This returns chunks one at a time.  If a new
2207   // class List can be created that is a base class
2208   // of FreeList then something like FreeList::prepend()
2209   // can be used in place of this loop
2210   while (cur != NULL) {
2211     assert(cur->container() != NULL, "Container should have been set");
2212     cur->container()->dec_container_count();
2213     // Capture the next link before it is changed
2214     // by the call to return_chunk_at_head();
2215     Metachunk* next = cur->next();
2216     DEBUG_ONLY(cur->set_is_tagged_free(true);)
2217     list->return_chunk_at_head(cur);
2218     cur = next;
2219   }
2220 }
2221 
2222 SpaceManager::~SpaceManager() {
2223   // This call this->_lock which can't be done while holding expand_lock()
2224   assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(),
2225     err_msg("sum_capacity_in_chunks_in_use() " SIZE_FORMAT
2226             " allocated_chunks_words() " SIZE_FORMAT,
2227             sum_capacity_in_chunks_in_use(), allocated_chunks_words()));
2228 
2229   MutexLockerEx fcl(SpaceManager::expand_lock(),
2230                     Mutex::_no_safepoint_check_flag);
2231 
2232   chunk_manager()->slow_locked_verify();
2233 
2234   dec_total_from_size_metrics();
2235 
2236   if (TraceMetadataChunkAllocation && Verbose) {
2237     gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
2238     locked_print_chunks_in_use_on(gclog_or_tty);
2239   }
2240 
2241   // Do not mangle freed Metachunks.  The chunk size inside Metachunks
2242   // is during the freeing of a VirtualSpaceNodes.
2243 
2244   // Have to update before the chunks_in_use lists are emptied
2245   // below.
2246   chunk_manager()->inc_free_chunks_total(allocated_chunks_words(),
2247                                          sum_count_in_chunks_in_use());
2248 
2249   // Add all the chunks in use by this space manager
2250   // to the global list of free chunks.
2251 
2252   // Follow each list of chunks-in-use and add them to the
2253   // free lists.  Each list is NULL terminated.
2254 
2255   for (ChunkIndex i = ZeroIndex; i < HumongousIndex; i = next_chunk_index(i)) {
2256     if (TraceMetadataChunkAllocation && Verbose) {
2257       gclog_or_tty->print_cr("returned %d %s chunks to freelist",
2258                              sum_count_in_chunks_in_use(i),
2259                              chunk_size_name(i));
2260     }
2261     Metachunk* chunks = chunks_in_use(i);
2262     chunk_manager()->return_chunks(i, chunks);
2263     set_chunks_in_use(i, NULL);
2264     if (TraceMetadataChunkAllocation && Verbose) {
2265       gclog_or_tty->print_cr("updated freelist count %d %s",
2266                              chunk_manager()->free_chunks(i)->count(),
2267                              chunk_size_name(i));
2268     }
2269     assert(i != HumongousIndex, "Humongous chunks are handled explicitly later");
2270   }
2271 
2272   // The medium chunk case may be optimized by passing the head and
2273   // tail of the medium chunk list to add_at_head().  The tail is often
2274   // the current chunk but there are probably exceptions.
2275 
2276   // Humongous chunks
2277   if (TraceMetadataChunkAllocation && Verbose) {
2278     gclog_or_tty->print_cr("returned %d %s humongous chunks to dictionary",
2279                             sum_count_in_chunks_in_use(HumongousIndex),
2280                             chunk_size_name(HumongousIndex));
2281     gclog_or_tty->print("Humongous chunk dictionary: ");
2282   }
2283   // Humongous chunks are never the current chunk.
2284   Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
2285 
2286   while (humongous_chunks != NULL) {
2287 #ifdef ASSERT
2288     humongous_chunks->set_is_tagged_free(true);
2289 #endif
2290     if (TraceMetadataChunkAllocation && Verbose) {
2291       gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ",
2292                           humongous_chunks,
2293                           humongous_chunks->word_size());
2294     }
2295     assert(humongous_chunks->word_size() == (size_t)
2296            align_size_up(humongous_chunks->word_size(),
2297                              smallest_chunk_size()),
2298            err_msg("Humongous chunk size is wrong: word size " SIZE_FORMAT
2299                    " granularity %d",
2300                    humongous_chunks->word_size(), smallest_chunk_size()));
2301     Metachunk* next_humongous_chunks = humongous_chunks->next();
2302     humongous_chunks->container()->dec_container_count();
2303     chunk_manager()->humongous_dictionary()->return_chunk(humongous_chunks);
2304     humongous_chunks = next_humongous_chunks;
2305   }
2306   if (TraceMetadataChunkAllocation && Verbose) {
2307     gclog_or_tty->cr();
2308     gclog_or_tty->print_cr("updated dictionary count %d %s",
2309                      chunk_manager()->humongous_dictionary()->total_count(),
2310                      chunk_size_name(HumongousIndex));
2311   }
2312   chunk_manager()->slow_locked_verify();
2313 }
2314 
2315 const char* SpaceManager::chunk_size_name(ChunkIndex index) const {
2316   switch (index) {
2317     case SpecializedIndex:
2318       return "Specialized";
2319     case SmallIndex:
2320       return "Small";
2321     case MediumIndex:
2322       return "Medium";
2323     case HumongousIndex:
2324       return "Humongous";
2325     default:
2326       return NULL;
2327   }
2328 }
2329 
2330 ChunkIndex ChunkManager::list_index(size_t size) {
2331   switch (size) {
2332     case SpecializedChunk:
2333       assert(SpecializedChunk == ClassSpecializedChunk,
2334              "Need branch for ClassSpecializedChunk");
2335       return SpecializedIndex;
2336     case SmallChunk:
2337     case ClassSmallChunk:
2338       return SmallIndex;
2339     case MediumChunk:
2340     case ClassMediumChunk:
2341       return MediumIndex;
2342     default:
2343       assert(size > MediumChunk || size > ClassMediumChunk,
2344              "Not a humongous chunk");
2345       return HumongousIndex;
2346   }
2347 }
2348 
2349 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
2350   assert_lock_strong(_lock);
2351   size_t raw_word_size = get_raw_word_size(word_size);
2352   size_t min_size = TreeChunk<Metablock, FreeList<Metablock> >::min_size();
2353   assert(raw_word_size >= min_size,
2354          err_msg("Should not deallocate dark matter " SIZE_FORMAT "<" SIZE_FORMAT, word_size, min_size));
2355   block_freelists()->return_block(p, raw_word_size);
2356 }
2357 
2358 // Adds a chunk to the list of chunks in use.
2359 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
2360 
2361   assert(new_chunk != NULL, "Should not be NULL");
2362   assert(new_chunk->next() == NULL, "Should not be on a list");
2363 
2364   new_chunk->reset_empty();
2365 
2366   // Find the correct list and and set the current
2367   // chunk for that list.
2368   ChunkIndex index = ChunkManager::list_index(new_chunk->word_size());
2369 
2370   if (index != HumongousIndex) {
2371     retire_current_chunk();
2372     set_current_chunk(new_chunk);
2373     new_chunk->set_next(chunks_in_use(index));
2374     set_chunks_in_use(index, new_chunk);
2375   } else {
2376     // For null class loader data and DumpSharedSpaces, the first chunk isn't
2377     // small, so small will be null.  Link this first chunk as the current
2378     // chunk.
2379     if (make_current) {
2380       // Set as the current chunk but otherwise treat as a humongous chunk.
2381       set_current_chunk(new_chunk);
2382     }
2383     // Link at head.  The _current_chunk only points to a humongous chunk for
2384     // the null class loader metaspace (class and data virtual space managers)
2385     // any humongous chunks so will not point to the tail
2386     // of the humongous chunks list.
2387     new_chunk->set_next(chunks_in_use(HumongousIndex));
2388     set_chunks_in_use(HumongousIndex, new_chunk);
2389 
2390     assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
2391   }
2392 
2393   // Add to the running sum of capacity
2394   inc_size_metrics(new_chunk->word_size());
2395 
2396   assert(new_chunk->is_empty(), "Not ready for reuse");
2397   if (TraceMetadataChunkAllocation && Verbose) {
2398     gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
2399                         sum_count_in_chunks_in_use());
2400     new_chunk->print_on(gclog_or_tty);
2401     chunk_manager()->locked_print_free_chunks(gclog_or_tty);
2402   }
2403 }
2404 
2405 void SpaceManager::retire_current_chunk() {
2406   if (current_chunk() != NULL) {
2407     size_t remaining_words = current_chunk()->free_word_size();
2408     if (remaining_words >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
2409       block_freelists()->return_block(current_chunk()->allocate(remaining_words), remaining_words);
2410       inc_used_metrics(remaining_words);
2411     }
2412   }
2413 }
2414 
2415 Metachunk* SpaceManager::get_new_chunk(size_t word_size,
2416                                        size_t grow_chunks_by_words) {
2417   // Get a chunk from the chunk freelist
2418   Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
2419 
2420   if (next == NULL) {
2421     next = vs_list()->get_new_chunk(word_size,
2422                                     grow_chunks_by_words,
2423                                     medium_chunk_bunch());
2424   }
2425 
2426   if (TraceMetadataHumongousAllocation && next != NULL &&
2427       SpaceManager::is_humongous(next->word_size())) {
2428     gclog_or_tty->print_cr("  new humongous chunk word size "
2429                            PTR_FORMAT, next->word_size());
2430   }
2431 
2432   return next;
2433 }
2434 
2435 MetaWord* SpaceManager::allocate(size_t word_size) {
2436   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2437 
2438   size_t raw_word_size = get_raw_word_size(word_size);
2439   BlockFreelist* fl =  block_freelists();
2440   MetaWord* p = NULL;
2441   // Allocation from the dictionary is expensive in the sense that
2442   // the dictionary has to be searched for a size.  Don't allocate
2443   // from the dictionary until it starts to get fat.  Is this
2444   // a reasonable policy?  Maybe an skinny dictionary is fast enough
2445   // for allocations.  Do some profiling.  JJJ
2446   if (fl->total_size() > allocation_from_dictionary_limit) {
2447     p = fl->get_block(raw_word_size);
2448   }
2449   if (p == NULL) {
2450     p = allocate_work(raw_word_size);
2451   }
2452 
2453   return p;
2454 }
2455 
2456 // Returns the address of spaced allocated for "word_size".
2457 // This methods does not know about blocks (Metablocks)
2458 MetaWord* SpaceManager::allocate_work(size_t word_size) {
2459   assert_lock_strong(_lock);
2460 #ifdef ASSERT
2461   if (Metadebug::test_metadata_failure()) {
2462     return NULL;
2463   }
2464 #endif
2465   // Is there space in the current chunk?
2466   MetaWord* result = NULL;
2467 
2468   // For DumpSharedSpaces, only allocate out of the current chunk which is
2469   // never null because we gave it the size we wanted.   Caller reports out
2470   // of memory if this returns null.
2471   if (DumpSharedSpaces) {
2472     assert(current_chunk() != NULL, "should never happen");
2473     inc_used_metrics(word_size);
2474     return current_chunk()->allocate(word_size); // caller handles null result
2475   }
2476 
2477   if (current_chunk() != NULL) {
2478     result = current_chunk()->allocate(word_size);
2479   }
2480 
2481   if (result == NULL) {
2482     result = grow_and_allocate(word_size);
2483   }
2484 
2485   if (result != NULL) {
2486     inc_used_metrics(word_size);
2487     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
2488            "Head of the list is being allocated");
2489   }
2490 
2491   return result;
2492 }
2493 
2494 void SpaceManager::verify() {
2495   // If there are blocks in the dictionary, then
2496   // verfication of chunks does not work since
2497   // being in the dictionary alters a chunk.
2498   if (block_freelists()->total_size() == 0) {
2499     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2500       Metachunk* curr = chunks_in_use(i);
2501       while (curr != NULL) {
2502         curr->verify();
2503         verify_chunk_size(curr);
2504         curr = curr->next();
2505       }
2506     }
2507   }
2508 }
2509 
2510 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
2511   assert(is_humongous(chunk->word_size()) ||
2512          chunk->word_size() == medium_chunk_size() ||
2513          chunk->word_size() == small_chunk_size() ||
2514          chunk->word_size() == specialized_chunk_size(),
2515          "Chunk size is wrong");
2516   return;
2517 }
2518 
2519 #ifdef ASSERT
2520 void SpaceManager::verify_allocated_blocks_words() {
2521   // Verification is only guaranteed at a safepoint.
2522   assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(),
2523     "Verification can fail if the applications is running");
2524   assert(allocated_blocks_words() == sum_used_in_chunks_in_use(),
2525     err_msg("allocation total is not consistent " SIZE_FORMAT
2526             " vs " SIZE_FORMAT,
2527             allocated_blocks_words(), sum_used_in_chunks_in_use()));
2528 }
2529 
2530 #endif
2531 
2532 void SpaceManager::dump(outputStream* const out) const {
2533   size_t curr_total = 0;
2534   size_t waste = 0;
2535   uint i = 0;
2536   size_t used = 0;
2537   size_t capacity = 0;
2538 
2539   // Add up statistics for all chunks in this SpaceManager.
2540   for (ChunkIndex index = ZeroIndex;
2541        index < NumberOfInUseLists;
2542        index = next_chunk_index(index)) {
2543     for (Metachunk* curr = chunks_in_use(index);
2544          curr != NULL;
2545          curr = curr->next()) {
2546       out->print("%d) ", i++);
2547       curr->print_on(out);
2548       curr_total += curr->word_size();
2549       used += curr->used_word_size();
2550       capacity += curr->word_size();
2551       waste += curr->free_word_size() + curr->overhead();;
2552     }
2553   }
2554 
2555   if (TraceMetadataChunkAllocation && Verbose) {
2556     block_freelists()->print_on(out);
2557   }
2558 
2559   size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size();
2560   // Free space isn't wasted.
2561   waste -= free;
2562 
2563   out->print_cr("total of all chunks "  SIZE_FORMAT " used " SIZE_FORMAT
2564                 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
2565                 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
2566 }
2567 
2568 #ifndef PRODUCT
2569 void SpaceManager::mangle_freed_chunks() {
2570   for (ChunkIndex index = ZeroIndex;
2571        index < NumberOfInUseLists;
2572        index = next_chunk_index(index)) {
2573     for (Metachunk* curr = chunks_in_use(index);
2574          curr != NULL;
2575          curr = curr->next()) {
2576       curr->mangle();
2577     }
2578   }
2579 }
2580 #endif // PRODUCT
2581 
2582 // MetaspaceAux
2583 
2584 
2585 size_t MetaspaceAux::_capacity_words[] = {0, 0};
2586 size_t MetaspaceAux::_used_words[] = {0, 0};
2587 
2588 size_t MetaspaceAux::free_bytes(Metaspace::MetadataType mdtype) {
2589   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2590   return list == NULL ? 0 : list->free_bytes();
2591 }
2592 
2593 size_t MetaspaceAux::free_bytes() {
2594   return free_bytes(Metaspace::ClassType) + free_bytes(Metaspace::NonClassType);
2595 }
2596 
2597 void MetaspaceAux::dec_capacity(Metaspace::MetadataType mdtype, size_t words) {
2598   assert_lock_strong(SpaceManager::expand_lock());
2599   assert(words <= capacity_words(mdtype),
2600     err_msg("About to decrement below 0: words " SIZE_FORMAT
2601             " is greater than _capacity_words[%u] " SIZE_FORMAT,
2602             words, mdtype, capacity_words(mdtype)));
2603   _capacity_words[mdtype] -= words;
2604 }
2605 
2606 void MetaspaceAux::inc_capacity(Metaspace::MetadataType mdtype, size_t words) {
2607   assert_lock_strong(SpaceManager::expand_lock());
2608   // Needs to be atomic
2609   _capacity_words[mdtype] += words;
2610 }
2611 
2612 void MetaspaceAux::dec_used(Metaspace::MetadataType mdtype, size_t words) {
2613   assert(words <= used_words(mdtype),
2614     err_msg("About to decrement below 0: words " SIZE_FORMAT
2615             " is greater than _used_words[%u] " SIZE_FORMAT,
2616             words, mdtype, used_words(mdtype)));
2617   // For CMS deallocation of the Metaspaces occurs during the
2618   // sweep which is a concurrent phase.  Protection by the expand_lock()
2619   // is not enough since allocation is on a per Metaspace basis
2620   // and protected by the Metaspace lock.
2621   jlong minus_words = (jlong) - (jlong) words;
2622   Atomic::add_ptr(minus_words, &_used_words[mdtype]);
2623 }
2624 
2625 void MetaspaceAux::inc_used(Metaspace::MetadataType mdtype, size_t words) {
2626   // _used_words tracks allocations for
2627   // each piece of metadata.  Those allocations are
2628   // generally done concurrently by different application
2629   // threads so must be done atomically.
2630   Atomic::add_ptr(words, &_used_words[mdtype]);
2631 }
2632 
2633 size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) {
2634   size_t used = 0;
2635   ClassLoaderDataGraphMetaspaceIterator iter;
2636   while (iter.repeat()) {
2637     Metaspace* msp = iter.get_next();
2638     // Sum allocated_blocks_words for each metaspace
2639     if (msp != NULL) {
2640       used += msp->used_words_slow(mdtype);
2641     }
2642   }
2643   return used * BytesPerWord;
2644 }
2645 
2646 size_t MetaspaceAux::free_bytes_slow(Metaspace::MetadataType mdtype) {
2647   size_t free = 0;
2648   ClassLoaderDataGraphMetaspaceIterator iter;
2649   while (iter.repeat()) {
2650     Metaspace* msp = iter.get_next();
2651     if (msp != NULL) {
2652       free += msp->free_words_slow(mdtype);
2653     }
2654   }
2655   return free * BytesPerWord;
2656 }
2657 
2658 size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) {
2659   if ((mdtype == Metaspace::ClassType) && !Metaspace::using_class_space()) {
2660     return 0;
2661   }
2662   // Don't count the space in the freelists.  That space will be
2663   // added to the capacity calculation as needed.
2664   size_t capacity = 0;
2665   ClassLoaderDataGraphMetaspaceIterator iter;
2666   while (iter.repeat()) {
2667     Metaspace* msp = iter.get_next();
2668     if (msp != NULL) {
2669       capacity += msp->capacity_words_slow(mdtype);
2670     }
2671   }
2672   return capacity * BytesPerWord;
2673 }
2674 
2675 size_t MetaspaceAux::capacity_bytes_slow() {
2676 #ifdef PRODUCT
2677   // Use capacity_bytes() in PRODUCT instead of this function.
2678   guarantee(false, "Should not call capacity_bytes_slow() in the PRODUCT");
2679 #endif
2680   size_t class_capacity = capacity_bytes_slow(Metaspace::ClassType);
2681   size_t non_class_capacity = capacity_bytes_slow(Metaspace::NonClassType);
2682   assert(capacity_bytes() == class_capacity + non_class_capacity,
2683       err_msg("bad accounting: capacity_bytes() " SIZE_FORMAT
2684         " class_capacity + non_class_capacity " SIZE_FORMAT
2685         " class_capacity " SIZE_FORMAT " non_class_capacity " SIZE_FORMAT,
2686         capacity_bytes(), class_capacity + non_class_capacity,
2687         class_capacity, non_class_capacity));
2688 
2689   return class_capacity + non_class_capacity;
2690 }
2691 
2692 size_t MetaspaceAux::reserved_bytes(Metaspace::MetadataType mdtype) {
2693   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2694   return list == NULL ? 0 : list->reserved_bytes();
2695 }
2696 
2697 size_t MetaspaceAux::committed_bytes(Metaspace::MetadataType mdtype) {
2698   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2699   return list == NULL ? 0 : list->committed_bytes();
2700 }
2701 
2702 size_t MetaspaceAux::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); }
2703 
2704 size_t MetaspaceAux::free_chunks_total_words(Metaspace::MetadataType mdtype) {
2705   ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype);
2706   if (chunk_manager == NULL) {
2707     return 0;
2708   }
2709   chunk_manager->slow_verify();
2710   return chunk_manager->free_chunks_total_words();
2711 }
2712 
2713 size_t MetaspaceAux::free_chunks_total_bytes(Metaspace::MetadataType mdtype) {
2714   return free_chunks_total_words(mdtype) * BytesPerWord;
2715 }
2716 
2717 size_t MetaspaceAux::free_chunks_total_words() {
2718   return free_chunks_total_words(Metaspace::ClassType) +
2719          free_chunks_total_words(Metaspace::NonClassType);
2720 }
2721 
2722 size_t MetaspaceAux::free_chunks_total_bytes() {
2723   return free_chunks_total_words() * BytesPerWord;
2724 }
2725 
2726 bool MetaspaceAux::has_chunk_free_list(Metaspace::MetadataType mdtype) {
2727   return Metaspace::get_chunk_manager(mdtype) != NULL;
2728 }
2729 
2730 MetaspaceChunkFreeListSummary MetaspaceAux::chunk_free_list_summary(Metaspace::MetadataType mdtype) {
2731   if (!has_chunk_free_list(mdtype)) {
2732     return MetaspaceChunkFreeListSummary();
2733   }
2734 
2735   const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype);
2736   return cm->chunk_free_list_summary();
2737 }
2738 
2739 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
2740   gclog_or_tty->print(", [Metaspace:");
2741   if (PrintGCDetails && Verbose) {
2742     gclog_or_tty->print(" "  SIZE_FORMAT
2743                         "->" SIZE_FORMAT
2744                         "("  SIZE_FORMAT ")",
2745                         prev_metadata_used,
2746                         used_bytes(),
2747                         reserved_bytes());
2748   } else {
2749     gclog_or_tty->print(" "  SIZE_FORMAT "K"
2750                         "->" SIZE_FORMAT "K"
2751                         "("  SIZE_FORMAT "K)",
2752                         prev_metadata_used/K,
2753                         used_bytes()/K,
2754                         reserved_bytes()/K);
2755   }
2756 
2757   gclog_or_tty->print("]");
2758 }
2759 
2760 // This is printed when PrintGCDetails
2761 void MetaspaceAux::print_on(outputStream* out) {
2762   Metaspace::MetadataType nct = Metaspace::NonClassType;
2763 
2764   out->print_cr(" Metaspace       "
2765                 "used "      SIZE_FORMAT "K, "
2766                 "capacity "  SIZE_FORMAT "K, "
2767                 "committed " SIZE_FORMAT "K, "
2768                 "reserved "  SIZE_FORMAT "K",
2769                 used_bytes()/K,
2770                 capacity_bytes()/K,
2771                 committed_bytes()/K,
2772                 reserved_bytes()/K);
2773 
2774   if (Metaspace::using_class_space()) {
2775     Metaspace::MetadataType ct = Metaspace::ClassType;
2776     out->print_cr("  class space    "
2777                   "used "      SIZE_FORMAT "K, "
2778                   "capacity "  SIZE_FORMAT "K, "
2779                   "committed " SIZE_FORMAT "K, "
2780                   "reserved "  SIZE_FORMAT "K",
2781                   used_bytes(ct)/K,
2782                   capacity_bytes(ct)/K,
2783                   committed_bytes(ct)/K,
2784                   reserved_bytes(ct)/K);
2785   }
2786 }
2787 
2788 // Print information for class space and data space separately.
2789 // This is almost the same as above.
2790 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
2791   size_t free_chunks_capacity_bytes = free_chunks_total_bytes(mdtype);
2792   size_t capacity_bytes = capacity_bytes_slow(mdtype);
2793   size_t used_bytes = used_bytes_slow(mdtype);
2794   size_t free_bytes = free_bytes_slow(mdtype);
2795   size_t used_and_free = used_bytes + free_bytes +
2796                            free_chunks_capacity_bytes;
2797   out->print_cr("  Chunk accounting: used in chunks " SIZE_FORMAT
2798              "K + unused in chunks " SIZE_FORMAT "K  + "
2799              " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
2800              "K  capacity in allocated chunks " SIZE_FORMAT "K",
2801              used_bytes / K,
2802              free_bytes / K,
2803              free_chunks_capacity_bytes / K,
2804              used_and_free / K,
2805              capacity_bytes / K);
2806   // Accounting can only be correct if we got the values during a safepoint
2807   assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong");
2808 }
2809 
2810 // Print total fragmentation for class metaspaces
2811 void MetaspaceAux::print_class_waste(outputStream* out) {
2812   assert(Metaspace::using_class_space(), "class metaspace not used");
2813   size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0;
2814   size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_humongous_count = 0;
2815   ClassLoaderDataGraphMetaspaceIterator iter;
2816   while (iter.repeat()) {
2817     Metaspace* msp = iter.get_next();
2818     if (msp != NULL) {
2819       cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2820       cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2821       cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2822       cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
2823       cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2824       cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
2825       cls_humongous_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2826     }
2827   }
2828   out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2829                 SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2830                 SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2831                 "large count " SIZE_FORMAT,
2832                 cls_specialized_count, cls_specialized_waste,
2833                 cls_small_count, cls_small_waste,
2834                 cls_medium_count, cls_medium_waste, cls_humongous_count);
2835 }
2836 
2837 // Print total fragmentation for data and class metaspaces separately
2838 void MetaspaceAux::print_waste(outputStream* out) {
2839   size_t specialized_waste = 0, small_waste = 0, medium_waste = 0;
2840   size_t specialized_count = 0, small_count = 0, medium_count = 0, humongous_count = 0;
2841 
2842   ClassLoaderDataGraphMetaspaceIterator iter;
2843   while (iter.repeat()) {
2844     Metaspace* msp = iter.get_next();
2845     if (msp != NULL) {
2846       specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2847       specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2848       small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2849       small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
2850       medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2851       medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
2852       humongous_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2853     }
2854   }
2855   out->print_cr("Total fragmentation waste (words) doesn't count free space");
2856   out->print_cr("  data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2857                         SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2858                         SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2859                         "large count " SIZE_FORMAT,
2860              specialized_count, specialized_waste, small_count,
2861              small_waste, medium_count, medium_waste, humongous_count);
2862   if (Metaspace::using_class_space()) {
2863     print_class_waste(out);
2864   }
2865 }
2866 
2867 // Dump global metaspace things from the end of ClassLoaderDataGraph
2868 void MetaspaceAux::dump(outputStream* out) {
2869   out->print_cr("All Metaspace:");
2870   out->print("data space: "); print_on(out, Metaspace::NonClassType);
2871   out->print("class space: "); print_on(out, Metaspace::ClassType);
2872   print_waste(out);
2873 }
2874 
2875 void MetaspaceAux::verify_free_chunks() {
2876   Metaspace::chunk_manager_metadata()->verify();
2877   if (Metaspace::using_class_space()) {
2878     Metaspace::chunk_manager_class()->verify();
2879   }
2880 }
2881 
2882 void MetaspaceAux::verify_capacity() {
2883 #ifdef ASSERT
2884   size_t running_sum_capacity_bytes = capacity_bytes();
2885   // For purposes of the running sum of capacity, verify against capacity
2886   size_t capacity_in_use_bytes = capacity_bytes_slow();
2887   assert(running_sum_capacity_bytes == capacity_in_use_bytes,
2888     err_msg("capacity_words() * BytesPerWord " SIZE_FORMAT
2889             " capacity_bytes_slow()" SIZE_FORMAT,
2890             running_sum_capacity_bytes, capacity_in_use_bytes));
2891   for (Metaspace::MetadataType i = Metaspace::ClassType;
2892        i < Metaspace:: MetadataTypeCount;
2893        i = (Metaspace::MetadataType)(i + 1)) {
2894     size_t capacity_in_use_bytes = capacity_bytes_slow(i);
2895     assert(capacity_bytes(i) == capacity_in_use_bytes,
2896       err_msg("capacity_bytes(%u) " SIZE_FORMAT
2897               " capacity_bytes_slow(%u)" SIZE_FORMAT,
2898               i, capacity_bytes(i), i, capacity_in_use_bytes));
2899   }
2900 #endif
2901 }
2902 
2903 void MetaspaceAux::verify_used() {
2904 #ifdef ASSERT
2905   size_t running_sum_used_bytes = used_bytes();
2906   // For purposes of the running sum of used, verify against used
2907   size_t used_in_use_bytes = used_bytes_slow();
2908   assert(used_bytes() == used_in_use_bytes,
2909     err_msg("used_bytes() " SIZE_FORMAT
2910             " used_bytes_slow()" SIZE_FORMAT,
2911             used_bytes(), used_in_use_bytes));
2912   for (Metaspace::MetadataType i = Metaspace::ClassType;
2913        i < Metaspace:: MetadataTypeCount;
2914        i = (Metaspace::MetadataType)(i + 1)) {
2915     size_t used_in_use_bytes = used_bytes_slow(i);
2916     assert(used_bytes(i) == used_in_use_bytes,
2917       err_msg("used_bytes(%u) " SIZE_FORMAT
2918               " used_bytes_slow(%u)" SIZE_FORMAT,
2919               i, used_bytes(i), i, used_in_use_bytes));
2920   }
2921 #endif
2922 }
2923 
2924 void MetaspaceAux::verify_metrics() {
2925   verify_capacity();
2926   verify_used();
2927 }
2928 
2929 
2930 // Metaspace methods
2931 
2932 size_t Metaspace::_first_chunk_word_size = 0;
2933 size_t Metaspace::_first_class_chunk_word_size = 0;
2934 
2935 size_t Metaspace::_commit_alignment = 0;
2936 size_t Metaspace::_reserve_alignment = 0;
2937 
2938 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
2939   initialize(lock, type);
2940 }
2941 
2942 Metaspace::~Metaspace() {
2943   delete _vsm;
2944   if (using_class_space()) {
2945     delete _class_vsm;
2946   }
2947 }
2948 
2949 VirtualSpaceList* Metaspace::_space_list = NULL;
2950 VirtualSpaceList* Metaspace::_class_space_list = NULL;
2951 
2952 ChunkManager* Metaspace::_chunk_manager_metadata = NULL;
2953 ChunkManager* Metaspace::_chunk_manager_class = NULL;
2954 
2955 #define VIRTUALSPACEMULTIPLIER 2
2956 
2957 #ifdef _LP64
2958 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
2959 
2960 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) {
2961   // Figure out the narrow_klass_base and the narrow_klass_shift.  The
2962   // narrow_klass_base is the lower of the metaspace base and the cds base
2963   // (if cds is enabled).  The narrow_klass_shift depends on the distance
2964   // between the lower base and higher address.
2965   address lower_base;
2966   address higher_address;
2967 #if INCLUDE_CDS
2968   if (UseSharedSpaces) {
2969     higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
2970                           (address)(metaspace_base + compressed_class_space_size()));
2971     lower_base = MIN2(metaspace_base, cds_base);
2972   } else
2973 #endif
2974   {
2975     higher_address = metaspace_base + compressed_class_space_size();
2976     lower_base = metaspace_base;
2977 
2978     uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes;
2979     // If compressed class space fits in lower 32G, we don't need a base.
2980     if (higher_address <= (address)klass_encoding_max) {
2981       lower_base = 0; // effectively lower base is zero.
2982     }
2983   }
2984 
2985   Universe::set_narrow_klass_base(lower_base);
2986 
2987   if ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) {
2988     Universe::set_narrow_klass_shift(0);
2989   } else {
2990     assert(!UseSharedSpaces, "Cannot shift with UseSharedSpaces");
2991     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
2992   }
2993 }
2994 
2995 #if INCLUDE_CDS
2996 // Return TRUE if the specified metaspace_base and cds_base are close enough
2997 // to work with compressed klass pointers.
2998 bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) {
2999   assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS");
3000   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3001   address lower_base = MIN2((address)metaspace_base, cds_base);
3002   address higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
3003                                 (address)(metaspace_base + compressed_class_space_size()));
3004   return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
3005 }
3006 #endif
3007 
3008 // Try to allocate the metaspace at the requested addr.
3009 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
3010   assert(using_class_space(), "called improperly");
3011   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3012   assert(compressed_class_space_size() < KlassEncodingMetaspaceMax,
3013          "Metaspace size is too big");
3014   assert_is_ptr_aligned(requested_addr, _reserve_alignment);
3015   assert_is_ptr_aligned(cds_base, _reserve_alignment);
3016   assert_is_size_aligned(compressed_class_space_size(), _reserve_alignment);
3017 
3018   // Don't use large pages for the class space.
3019   bool large_pages = false;
3020 
3021   ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(),
3022                                              _reserve_alignment,
3023                                              large_pages,
3024                                              requested_addr, 0);
3025   if (!metaspace_rs.is_reserved()) {
3026 #if INCLUDE_CDS
3027     if (UseSharedSpaces) {
3028       size_t increment = align_size_up(1*G, _reserve_alignment);
3029 
3030       // Keep trying to allocate the metaspace, increasing the requested_addr
3031       // by 1GB each time, until we reach an address that will no longer allow
3032       // use of CDS with compressed klass pointers.
3033       char *addr = requested_addr;
3034       while (!metaspace_rs.is_reserved() && (addr + increment > addr) &&
3035              can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
3036         addr = addr + increment;
3037         metaspace_rs = ReservedSpace(compressed_class_space_size(),
3038                                      _reserve_alignment, large_pages, addr, 0);
3039       }
3040     }
3041 #endif
3042     // If no successful allocation then try to allocate the space anywhere.  If
3043     // that fails then OOM doom.  At this point we cannot try allocating the
3044     // metaspace as if UseCompressedClassPointers is off because too much
3045     // initialization has happened that depends on UseCompressedClassPointers.
3046     // So, UseCompressedClassPointers cannot be turned off at this point.
3047     if (!metaspace_rs.is_reserved()) {
3048       metaspace_rs = ReservedSpace(compressed_class_space_size(),
3049                                    _reserve_alignment, large_pages);
3050       if (!metaspace_rs.is_reserved()) {
3051         vm_exit_during_initialization(err_msg("Could not allocate metaspace: %d bytes",
3052                                               compressed_class_space_size()));
3053       }
3054     }
3055   }
3056 
3057   // If we got here then the metaspace got allocated.
3058   MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass);
3059 
3060 #if INCLUDE_CDS
3061   // Verify that we can use shared spaces.  Otherwise, turn off CDS.
3062   if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) {
3063     FileMapInfo::stop_sharing_and_unmap(
3064         "Could not allocate metaspace at a compatible address");
3065   }
3066 #endif
3067   set_narrow_klass_base_and_shift((address)metaspace_rs.base(),
3068                                   UseSharedSpaces ? (address)cds_base : 0);
3069 
3070   initialize_class_space(metaspace_rs);
3071 
3072   if (PrintCompressedOopsMode || (PrintMiscellaneous && Verbose)) {
3073     gclog_or_tty->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: " SIZE_FORMAT,
3074                             Universe::narrow_klass_base(), Universe::narrow_klass_shift());
3075     gclog_or_tty->print_cr("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT " Req Addr: " PTR_FORMAT,
3076                            compressed_class_space_size(), metaspace_rs.base(), requested_addr);
3077   }
3078 }
3079 
3080 // For UseCompressedClassPointers the class space is reserved above the top of
3081 // the Java heap.  The argument passed in is at the base of the compressed space.
3082 void Metaspace::initialize_class_space(ReservedSpace rs) {
3083   // The reserved space size may be bigger because of alignment, esp with UseLargePages
3084   assert(rs.size() >= CompressedClassSpaceSize,
3085          err_msg(SIZE_FORMAT " != " UINTX_FORMAT, rs.size(), CompressedClassSpaceSize));
3086   assert(using_class_space(), "Must be using class space");
3087   _class_space_list = new VirtualSpaceList(rs);
3088   _chunk_manager_class = new ChunkManager(SpecializedChunk, ClassSmallChunk, ClassMediumChunk);
3089 
3090   if (!_class_space_list->initialization_succeeded()) {
3091     vm_exit_during_initialization("Failed to setup compressed class space virtual space list.");
3092   }
3093 }
3094 
3095 #endif
3096 
3097 void Metaspace::ergo_initialize() {
3098   if (DumpSharedSpaces) {
3099     // Using large pages when dumping the shared archive is currently not implemented.
3100     FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false);
3101   }
3102 
3103   size_t page_size = os::vm_page_size();
3104   if (UseLargePages && UseLargePagesInMetaspace) {
3105     page_size = os::large_page_size();
3106   }
3107 
3108   _commit_alignment  = page_size;
3109   _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
3110 
3111   // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
3112   // override if MaxMetaspaceSize was set on the command line or not.
3113   // This information is needed later to conform to the specification of the
3114   // java.lang.management.MemoryUsage API.
3115   //
3116   // Ideally, we would be able to set the default value of MaxMetaspaceSize in
3117   // globals.hpp to the aligned value, but this is not possible, since the
3118   // alignment depends on other flags being parsed.
3119   MaxMetaspaceSize = align_size_down_bounded(MaxMetaspaceSize, _reserve_alignment);
3120 
3121   if (MetaspaceSize > MaxMetaspaceSize) {
3122     MetaspaceSize = MaxMetaspaceSize;
3123   }
3124 
3125   MetaspaceSize = align_size_down_bounded(MetaspaceSize, _commit_alignment);
3126 
3127   assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
3128 
3129   if (MetaspaceSize < 256*K) {
3130     vm_exit_during_initialization("Too small initial Metaspace size");
3131   }
3132 
3133   MinMetaspaceExpansion = align_size_down_bounded(MinMetaspaceExpansion, _commit_alignment);
3134   MaxMetaspaceExpansion = align_size_down_bounded(MaxMetaspaceExpansion, _commit_alignment);
3135 
3136   CompressedClassSpaceSize = align_size_down_bounded(CompressedClassSpaceSize, _reserve_alignment);
3137   set_compressed_class_space_size(CompressedClassSpaceSize);
3138 }
3139 
3140 void Metaspace::global_initialize() {
3141   MetaspaceGC::initialize();
3142 
3143   // Initialize the alignment for shared spaces.
3144   int max_alignment = os::vm_allocation_granularity();
3145   size_t cds_total = 0;
3146 
3147   MetaspaceShared::set_max_alignment(max_alignment);
3148 
3149   if (DumpSharedSpaces) {
3150 #if INCLUDE_CDS
3151     MetaspaceShared::estimate_regions_size();
3152 
3153     SharedReadOnlySize  = align_size_up(SharedReadOnlySize,  max_alignment);
3154     SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
3155     SharedMiscDataSize  = align_size_up(SharedMiscDataSize,  max_alignment);
3156     SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize,  max_alignment);
3157 
3158     // the min_misc_code_size estimate is based on MetaspaceShared::generate_vtable_methods()
3159     uintx min_misc_code_size = align_size_up(
3160       (MetaspaceShared::num_virtuals * MetaspaceShared::vtbl_list_size) *
3161         (sizeof(void*) + MetaspaceShared::vtbl_method_size) + MetaspaceShared::vtbl_common_code_size,
3162           max_alignment);
3163 
3164     if (SharedMiscCodeSize < min_misc_code_size) {
3165       report_out_of_shared_space(SharedMiscCode);
3166     }
3167 
3168     // Initialize with the sum of the shared space sizes.  The read-only
3169     // and read write metaspace chunks will be allocated out of this and the
3170     // remainder is the misc code and data chunks.
3171     cds_total = FileMapInfo::shared_spaces_size();
3172     cds_total = align_size_up(cds_total, _reserve_alignment);
3173     _space_list = new VirtualSpaceList(cds_total/wordSize);
3174     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3175 
3176     if (!_space_list->initialization_succeeded()) {
3177       vm_exit_during_initialization("Unable to dump shared archive.", NULL);
3178     }
3179 
3180 #ifdef _LP64
3181     if (cds_total + compressed_class_space_size() > UnscaledClassSpaceMax) {
3182       vm_exit_during_initialization("Unable to dump shared archive.",
3183           err_msg("Size of archive (" SIZE_FORMAT ") + compressed class space ("
3184                   SIZE_FORMAT ") == total (" SIZE_FORMAT ") is larger than compressed "
3185                   "klass limit: " SIZE_FORMAT, cds_total, compressed_class_space_size(),
3186                   cds_total + compressed_class_space_size(), UnscaledClassSpaceMax));
3187     }
3188 
3189     // Set the compressed klass pointer base so that decoding of these pointers works
3190     // properly when creating the shared archive.
3191     assert(UseCompressedOops && UseCompressedClassPointers,
3192       "UseCompressedOops and UseCompressedClassPointers must be set");
3193     Universe::set_narrow_klass_base((address)_space_list->current_virtual_space()->bottom());
3194     if (TraceMetavirtualspaceAllocation && Verbose) {
3195       gclog_or_tty->print_cr("Setting_narrow_klass_base to Address: " PTR_FORMAT,
3196                              _space_list->current_virtual_space()->bottom());
3197     }
3198 
3199     Universe::set_narrow_klass_shift(0);
3200 #endif // _LP64
3201 #endif // INCLUDE_CDS
3202   } else {
3203 #if INCLUDE_CDS
3204     // If using shared space, open the file that contains the shared space
3205     // and map in the memory before initializing the rest of metaspace (so
3206     // the addresses don't conflict)
3207     address cds_address = NULL;
3208     if (UseSharedSpaces) {
3209       FileMapInfo* mapinfo = new FileMapInfo();
3210 
3211       // Open the shared archive file, read and validate the header. If
3212       // initialization fails, shared spaces [UseSharedSpaces] are
3213       // disabled and the file is closed.
3214       // Map in spaces now also
3215       if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
3216         cds_total = FileMapInfo::shared_spaces_size();
3217         cds_address = (address)mapinfo->region_base(0);
3218       } else {
3219         assert(!mapinfo->is_open() && !UseSharedSpaces,
3220                "archive file not closed or shared spaces not disabled.");
3221       }
3222     }
3223 #endif // INCLUDE_CDS
3224 #ifdef _LP64
3225     // If UseCompressedClassPointers is set then allocate the metaspace area
3226     // above the heap and above the CDS area (if it exists).
3227     if (using_class_space()) {
3228       if (UseSharedSpaces) {
3229 #if INCLUDE_CDS
3230         char* cds_end = (char*)(cds_address + cds_total);
3231         cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
3232         allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
3233 #endif
3234       } else {
3235         char* base = (char*)align_ptr_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
3236         allocate_metaspace_compressed_klass_ptrs(base, 0);
3237       }
3238     }
3239 #endif // _LP64
3240 
3241     // Initialize these before initializing the VirtualSpaceList
3242     _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
3243     _first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
3244     // Make the first class chunk bigger than a medium chunk so it's not put
3245     // on the medium chunk list.   The next chunk will be small and progress
3246     // from there.  This size calculated by -version.
3247     _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
3248                                        (CompressedClassSpaceSize/BytesPerWord)*2);
3249     _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
3250     // Arbitrarily set the initial virtual space to a multiple
3251     // of the boot class loader size.
3252     size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size;
3253     word_size = align_size_up(word_size, Metaspace::reserve_alignment_words());
3254 
3255     // Initialize the list of virtual spaces.
3256     _space_list = new VirtualSpaceList(word_size);
3257     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3258 
3259     if (!_space_list->initialization_succeeded()) {
3260       vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL);
3261     }
3262   }
3263 
3264   _tracer = new MetaspaceTracer();
3265 }
3266 
3267 void Metaspace::post_initialize() {
3268   MetaspaceGC::post_initialize();
3269 }
3270 
3271 Metachunk* Metaspace::get_initialization_chunk(MetadataType mdtype,
3272                                                size_t chunk_word_size,
3273                                                size_t chunk_bunch) {
3274   // Get a chunk from the chunk freelist
3275   Metachunk* chunk = get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size);
3276   if (chunk != NULL) {
3277     return chunk;
3278   }
3279 
3280   return get_space_list(mdtype)->get_new_chunk(chunk_word_size, chunk_word_size, chunk_bunch);
3281 }
3282 
3283 void Metaspace::initialize(Mutex* lock, MetaspaceType type) {
3284 
3285   assert(space_list() != NULL,
3286     "Metadata VirtualSpaceList has not been initialized");
3287   assert(chunk_manager_metadata() != NULL,
3288     "Metadata ChunkManager has not been initialized");
3289 
3290   _vsm = new SpaceManager(NonClassType, lock);
3291   if (_vsm == NULL) {
3292     return;
3293   }
3294   size_t word_size;
3295   size_t class_word_size;
3296   vsm()->get_initial_chunk_sizes(type, &word_size, &class_word_size);
3297 
3298   if (using_class_space()) {
3299   assert(class_space_list() != NULL,
3300     "Class VirtualSpaceList has not been initialized");
3301   assert(chunk_manager_class() != NULL,
3302     "Class ChunkManager has not been initialized");
3303 
3304     // Allocate SpaceManager for classes.
3305     _class_vsm = new SpaceManager(ClassType, lock);
3306     if (_class_vsm == NULL) {
3307       return;
3308     }
3309   }
3310 
3311   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3312 
3313   // Allocate chunk for metadata objects
3314   Metachunk* new_chunk = get_initialization_chunk(NonClassType,
3315                                                   word_size,
3316                                                   vsm()->medium_chunk_bunch());
3317   assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
3318   if (new_chunk != NULL) {
3319     // Add to this manager's list of chunks in use and current_chunk().
3320     vsm()->add_chunk(new_chunk, true);
3321   }
3322 
3323   // Allocate chunk for class metadata objects
3324   if (using_class_space()) {
3325     Metachunk* class_chunk = get_initialization_chunk(ClassType,
3326                                                       class_word_size,
3327                                                       class_vsm()->medium_chunk_bunch());
3328     if (class_chunk != NULL) {
3329       class_vsm()->add_chunk(class_chunk, true);
3330     }
3331   }
3332 
3333   _alloc_record_head = NULL;
3334   _alloc_record_tail = NULL;
3335 }
3336 
3337 size_t Metaspace::align_word_size_up(size_t word_size) {
3338   size_t byte_size = word_size * wordSize;
3339   return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
3340 }
3341 
3342 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
3343   // DumpSharedSpaces doesn't use class metadata area (yet)
3344   // Also, don't use class_vsm() unless UseCompressedClassPointers is true.
3345   if (is_class_space_allocation(mdtype)) {
3346     return  class_vsm()->allocate(word_size);
3347   } else {
3348     return  vsm()->allocate(word_size);
3349   }
3350 }
3351 
3352 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
3353   size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
3354   assert(delta_bytes > 0, "Must be");
3355 
3356   size_t before = 0;
3357   size_t after = 0;
3358   MetaWord* res;
3359   bool incremented;
3360 
3361   // Each thread increments the HWM at most once. Even if the thread fails to increment
3362   // the HWM, an allocation is still attempted. This is because another thread must then
3363   // have incremented the HWM and therefore the allocation might still succeed.
3364   do {
3365     incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before);
3366     res = allocate(word_size, mdtype);
3367   } while (!incremented && res == NULL);
3368 
3369   if (incremented) {
3370     tracer()->report_gc_threshold(before, after,
3371                                   MetaspaceGCThresholdUpdater::ExpandAndAllocate);
3372     if (PrintGCDetails && Verbose) {
3373       gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
3374           " to " SIZE_FORMAT, before, after);
3375     }
3376   }
3377 
3378   return res;
3379 }
3380 
3381 // Space allocated in the Metaspace.  This may
3382 // be across several metadata virtual spaces.
3383 char* Metaspace::bottom() const {
3384   assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
3385   return (char*)vsm()->current_chunk()->bottom();
3386 }
3387 
3388 size_t Metaspace::used_words_slow(MetadataType mdtype) const {
3389   if (mdtype == ClassType) {
3390     return using_class_space() ? class_vsm()->sum_used_in_chunks_in_use() : 0;
3391   } else {
3392     return vsm()->sum_used_in_chunks_in_use();  // includes overhead!
3393   }
3394 }
3395 
3396 size_t Metaspace::free_words_slow(MetadataType mdtype) const {
3397   if (mdtype == ClassType) {
3398     return using_class_space() ? class_vsm()->sum_free_in_chunks_in_use() : 0;
3399   } else {
3400     return vsm()->sum_free_in_chunks_in_use();
3401   }
3402 }
3403 
3404 // Space capacity in the Metaspace.  It includes
3405 // space in the list of chunks from which allocations
3406 // have been made. Don't include space in the global freelist and
3407 // in the space available in the dictionary which
3408 // is already counted in some chunk.
3409 size_t Metaspace::capacity_words_slow(MetadataType mdtype) const {
3410   if (mdtype == ClassType) {
3411     return using_class_space() ? class_vsm()->sum_capacity_in_chunks_in_use() : 0;
3412   } else {
3413     return vsm()->sum_capacity_in_chunks_in_use();
3414   }
3415 }
3416 
3417 size_t Metaspace::used_bytes_slow(MetadataType mdtype) const {
3418   return used_words_slow(mdtype) * BytesPerWord;
3419 }
3420 
3421 size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const {
3422   return capacity_words_slow(mdtype) * BytesPerWord;
3423 }
3424 
3425 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
3426   if (SafepointSynchronize::is_at_safepoint()) {
3427     if (DumpSharedSpaces && PrintSharedSpaces) {
3428       record_deallocation(ptr, vsm()->get_raw_word_size(word_size));
3429     }
3430 
3431     assert(Thread::current()->is_VM_thread(), "should be the VM thread");
3432     // Don't take Heap_lock
3433     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
3434     if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
3435       // Dark matter.  Too small for dictionary.
3436 #ifdef ASSERT
3437       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
3438 #endif
3439       return;
3440     }
3441     if (is_class && using_class_space()) {
3442       class_vsm()->deallocate(ptr, word_size);
3443     } else {
3444       vsm()->deallocate(ptr, word_size);
3445     }
3446   } else {
3447     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
3448 
3449     if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
3450       // Dark matter.  Too small for dictionary.
3451 #ifdef ASSERT
3452       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
3453 #endif
3454       return;
3455     }
3456     if (is_class && using_class_space()) {
3457       class_vsm()->deallocate(ptr, word_size);
3458     } else {
3459       vsm()->deallocate(ptr, word_size);
3460     }
3461   }
3462 }
3463 
3464 
3465 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
3466                               bool read_only, MetaspaceObj::Type type, TRAPS) {
3467   if (HAS_PENDING_EXCEPTION) {
3468     assert(false, "Should not allocate with exception pending");
3469     return NULL;  // caller does a CHECK_NULL too
3470   }
3471 
3472   assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
3473         "ClassLoaderData::the_null_class_loader_data() should have been used.");
3474 
3475   // Allocate in metaspaces without taking out a lock, because it deadlocks
3476   // with the SymbolTable_lock.  Dumping is single threaded for now.  We'll have
3477   // to revisit this for application class data sharing.
3478   if (DumpSharedSpaces) {
3479     assert(type > MetaspaceObj::UnknownType && type < MetaspaceObj::_number_of_types, "sanity");
3480     Metaspace* space = read_only ? loader_data->ro_metaspace() : loader_data->rw_metaspace();
3481     MetaWord* result = space->allocate(word_size, NonClassType);
3482     if (result == NULL) {
3483       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
3484     }
3485     if (PrintSharedSpaces) {
3486       space->record_allocation(result, type, space->vsm()->get_raw_word_size(word_size));
3487     }
3488 
3489     // Zero initialize.
3490     Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3491 
3492     return result;
3493   }
3494 
3495   MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
3496 
3497   // Try to allocate metadata.
3498   MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
3499 
3500   if (result == NULL) {
3501     tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
3502 
3503     // Allocation failed.
3504     if (is_init_completed()) {
3505       // Only start a GC if the bootstrapping has completed.
3506 
3507       // Try to clean out some memory and retry.
3508       result = Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
3509           loader_data, word_size, mdtype);
3510     }
3511   }
3512 
3513   if (result == NULL) {
3514     report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL);
3515   }
3516 
3517   // Zero initialize.
3518   Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3519 
3520   return result;
3521 }
3522 
3523 size_t Metaspace::class_chunk_size(size_t word_size) {
3524   assert(using_class_space(), "Has to use class space");
3525   return class_vsm()->calc_chunk_size(word_size);
3526 }
3527 
3528 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
3529   tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
3530 
3531   // If result is still null, we are out of memory.
3532   if (Verbose && TraceMetadataChunkAllocation) {
3533     gclog_or_tty->print_cr("Metaspace allocation failed for size "
3534         SIZE_FORMAT, word_size);
3535     if (loader_data->metaspace_or_null() != NULL) {
3536       loader_data->dump(gclog_or_tty);
3537     }
3538     MetaspaceAux::dump(gclog_or_tty);
3539   }
3540 
3541   bool out_of_compressed_class_space = false;
3542   if (is_class_space_allocation(mdtype)) {
3543     Metaspace* metaspace = loader_data->metaspace_non_null();
3544     out_of_compressed_class_space =
3545       MetaspaceAux::committed_bytes(Metaspace::ClassType) +
3546       (metaspace->class_chunk_size(word_size) * BytesPerWord) >
3547       CompressedClassSpaceSize;
3548   }
3549 
3550   // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
3551   const char* space_string = out_of_compressed_class_space ?
3552     "Compressed class space" : "Metaspace";
3553 
3554   report_java_out_of_memory(space_string);
3555 
3556   if (JvmtiExport::should_post_resource_exhausted()) {
3557     JvmtiExport::post_resource_exhausted(
3558         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
3559         space_string);
3560   }
3561 
3562   if (!is_init_completed()) {
3563     vm_exit_during_initialization("OutOfMemoryError", space_string);
3564   }
3565 
3566   if (out_of_compressed_class_space) {
3567     THROW_OOP(Universe::out_of_memory_error_class_metaspace());
3568   } else {
3569     THROW_OOP(Universe::out_of_memory_error_metaspace());
3570   }
3571 }
3572 
3573 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) {
3574   switch (mdtype) {
3575     case Metaspace::ClassType: return "Class";
3576     case Metaspace::NonClassType: return "Metadata";
3577     default:
3578       assert(false, err_msg("Got bad mdtype: %d", (int) mdtype));
3579       return NULL;
3580   }
3581 }
3582 
3583 void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
3584   assert(DumpSharedSpaces, "sanity");
3585 
3586   int byte_size = (int)word_size * HeapWordSize;
3587   AllocRecord *rec = new AllocRecord((address)ptr, type, byte_size);
3588 
3589   if (_alloc_record_head == NULL) {
3590     _alloc_record_head = _alloc_record_tail = rec;
3591   } else if (_alloc_record_tail->_ptr + _alloc_record_tail->_byte_size == (address)ptr) {
3592     _alloc_record_tail->_next = rec;
3593     _alloc_record_tail = rec;
3594   } else {
3595     // slow linear search, but this doesn't happen that often, and only when dumping
3596     for (AllocRecord *old = _alloc_record_head; old; old = old->_next) {
3597       if (old->_ptr == ptr) {
3598         assert(old->_type == MetaspaceObj::DeallocatedType, "sanity");
3599         int remain_bytes = old->_byte_size - byte_size;
3600         assert(remain_bytes >= 0, "sanity");
3601         old->_type = type;
3602 
3603         if (remain_bytes == 0) {
3604           delete(rec);
3605         } else {
3606           address remain_ptr = address(ptr) + byte_size;
3607           rec->_ptr = remain_ptr;
3608           rec->_byte_size = remain_bytes;
3609           rec->_type = MetaspaceObj::DeallocatedType;
3610           rec->_next = old->_next;
3611           old->_byte_size = byte_size;
3612           old->_next = rec;
3613         }
3614         return;
3615       }
3616     }
3617     assert(0, "reallocating a freed pointer that was not recorded");
3618   }
3619 }
3620 
3621 void Metaspace::record_deallocation(void* ptr, size_t word_size) {
3622   assert(DumpSharedSpaces, "sanity");
3623 
3624   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3625     if (rec->_ptr == ptr) {
3626       assert(rec->_byte_size == (int)word_size * HeapWordSize, "sanity");
3627       rec->_type = MetaspaceObj::DeallocatedType;
3628       return;
3629     }
3630   }
3631 
3632   assert(0, "deallocating a pointer that was not recorded");
3633 }
3634 
3635 void Metaspace::iterate(Metaspace::AllocRecordClosure *closure) {
3636   assert(DumpSharedSpaces, "unimplemented for !DumpSharedSpaces");
3637 
3638   address last_addr = (address)bottom();
3639 
3640   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3641     address ptr = rec->_ptr;
3642     if (last_addr < ptr) {
3643       closure->doit(last_addr, MetaspaceObj::UnknownType, ptr - last_addr);
3644     }
3645     closure->doit(ptr, rec->_type, rec->_byte_size);
3646     last_addr = ptr + rec->_byte_size;
3647   }
3648 
3649   address top = ((address)bottom()) + used_bytes_slow(Metaspace::NonClassType);
3650   if (last_addr < top) {
3651     closure->doit(last_addr, MetaspaceObj::UnknownType, top - last_addr);
3652   }
3653 }
3654 
3655 void Metaspace::purge(MetadataType mdtype) {
3656   get_space_list(mdtype)->purge(get_chunk_manager(mdtype));
3657 }
3658 
3659 void Metaspace::purge() {
3660   MutexLockerEx cl(SpaceManager::expand_lock(),
3661                    Mutex::_no_safepoint_check_flag);
3662   purge(NonClassType);
3663   if (using_class_space()) {
3664     purge(ClassType);
3665   }
3666 }
3667 
3668 void Metaspace::print_on(outputStream* out) const {
3669   // Print both class virtual space counts and metaspace.
3670   if (Verbose) {
3671     vsm()->print_on(out);
3672     if (using_class_space()) {
3673       class_vsm()->print_on(out);
3674     }
3675   }
3676 }
3677 
3678 bool Metaspace::contains(const void* ptr) {
3679   if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(ptr)) {
3680     return true;
3681   }
3682 
3683   if (using_class_space() && get_space_list(ClassType)->contains(ptr)) {
3684      return true;
3685   }
3686 
3687   return get_space_list(NonClassType)->contains(ptr);
3688 }
3689 
3690 void Metaspace::verify() {
3691   vsm()->verify();
3692   if (using_class_space()) {
3693     class_vsm()->verify();
3694   }
3695 }
3696 
3697 void Metaspace::dump(outputStream* const out) const {
3698   out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
3699   vsm()->dump(out);
3700   if (using_class_space()) {
3701     out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
3702     class_vsm()->dump(out);
3703   }
3704 }
3705 
3706 /////////////// Unit tests ///////////////
3707 
3708 #ifndef PRODUCT
3709 
3710 class TestMetaspaceAuxTest : AllStatic {
3711  public:
3712   static void test_reserved() {
3713     size_t reserved = MetaspaceAux::reserved_bytes();
3714 
3715     assert(reserved > 0, "assert");
3716 
3717     size_t committed  = MetaspaceAux::committed_bytes();
3718     assert(committed <= reserved, "assert");
3719 
3720     size_t reserved_metadata = MetaspaceAux::reserved_bytes(Metaspace::NonClassType);
3721     assert(reserved_metadata > 0, "assert");
3722     assert(reserved_metadata <= reserved, "assert");
3723 
3724     if (UseCompressedClassPointers) {
3725       size_t reserved_class    = MetaspaceAux::reserved_bytes(Metaspace::ClassType);
3726       assert(reserved_class > 0, "assert");
3727       assert(reserved_class < reserved, "assert");
3728     }
3729   }
3730 
3731   static void test_committed() {
3732     size_t committed = MetaspaceAux::committed_bytes();
3733 
3734     assert(committed > 0, "assert");
3735 
3736     size_t reserved  = MetaspaceAux::reserved_bytes();
3737     assert(committed <= reserved, "assert");
3738 
3739     size_t committed_metadata = MetaspaceAux::committed_bytes(Metaspace::NonClassType);
3740     assert(committed_metadata > 0, "assert");
3741     assert(committed_metadata <= committed, "assert");
3742 
3743     if (UseCompressedClassPointers) {
3744       size_t committed_class    = MetaspaceAux::committed_bytes(Metaspace::ClassType);
3745       assert(committed_class > 0, "assert");
3746       assert(committed_class < committed, "assert");
3747     }
3748   }
3749 
3750   static void test_virtual_space_list_large_chunk() {
3751     VirtualSpaceList* vs_list = new VirtualSpaceList(os::vm_allocation_granularity());
3752     MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3753     // A size larger than VirtualSpaceSize (256k) and add one page to make it _not_ be
3754     // vm_allocation_granularity aligned on Windows.
3755     size_t large_size = (size_t)(2*256*K + (os::vm_page_size()/BytesPerWord));
3756     large_size += (os::vm_page_size()/BytesPerWord);
3757     vs_list->get_new_chunk(large_size, large_size, 0);
3758   }
3759 
3760   static void test() {
3761     test_reserved();
3762     test_committed();
3763     test_virtual_space_list_large_chunk();
3764   }
3765 };
3766 
3767 void TestMetaspaceAux_test() {
3768   TestMetaspaceAuxTest::test();
3769 }
3770 
3771 class TestVirtualSpaceNodeTest {
3772   static void chunk_up(size_t words_left, size_t& num_medium_chunks,
3773                                           size_t& num_small_chunks,
3774                                           size_t& num_specialized_chunks) {
3775     num_medium_chunks = words_left / MediumChunk;
3776     words_left = words_left % MediumChunk;
3777 
3778     num_small_chunks = words_left / SmallChunk;
3779     words_left = words_left % SmallChunk;
3780     // how many specialized chunks can we get?
3781     num_specialized_chunks = words_left / SpecializedChunk;
3782     assert(words_left % SpecializedChunk == 0, "should be nothing left");
3783   }
3784 
3785  public:
3786   static void test() {
3787     MutexLockerEx ml(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3788     const size_t vsn_test_size_words = MediumChunk  * 4;
3789     const size_t vsn_test_size_bytes = vsn_test_size_words * BytesPerWord;
3790 
3791     // The chunk sizes must be multiples of eachother, or this will fail
3792     STATIC_ASSERT(MediumChunk % SmallChunk == 0);
3793     STATIC_ASSERT(SmallChunk % SpecializedChunk == 0);
3794 
3795     { // No committed memory in VSN
3796       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3797       VirtualSpaceNode vsn(vsn_test_size_bytes);
3798       vsn.initialize();
3799       vsn.retire(&cm);
3800       assert(cm.sum_free_chunks_count() == 0, "did not commit any memory in the VSN");
3801     }
3802 
3803     { // All of VSN is committed, half is used by chunks
3804       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3805       VirtualSpaceNode vsn(vsn_test_size_bytes);
3806       vsn.initialize();
3807       vsn.expand_by(vsn_test_size_words, vsn_test_size_words);
3808       vsn.get_chunk_vs(MediumChunk);
3809       vsn.get_chunk_vs(MediumChunk);
3810       vsn.retire(&cm);
3811       assert(cm.sum_free_chunks_count() == 2, "should have been memory left for 2 medium chunks");
3812       assert(cm.sum_free_chunks() == 2*MediumChunk, "sizes should add up");
3813     }
3814 
3815     { // 4 pages of VSN is committed, some is used by chunks
3816       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3817       VirtualSpaceNode vsn(vsn_test_size_bytes);
3818       const size_t page_chunks = 4 * (size_t)os::vm_page_size() / BytesPerWord;
3819       assert(page_chunks < MediumChunk, "Test expects medium chunks to be at least 4*page_size");
3820       vsn.initialize();
3821       vsn.expand_by(page_chunks, page_chunks);
3822       vsn.get_chunk_vs(SmallChunk);
3823       vsn.get_chunk_vs(SpecializedChunk);
3824       vsn.retire(&cm);
3825 
3826       // committed - used = words left to retire
3827       const size_t words_left = page_chunks - SmallChunk - SpecializedChunk;
3828 
3829       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3830       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3831 
3832       assert(num_medium_chunks == 0, "should not get any medium chunks");
3833       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3834       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3835     }
3836 
3837     { // Half of VSN is committed, a humongous chunk is used
3838       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3839       VirtualSpaceNode vsn(vsn_test_size_bytes);
3840       vsn.initialize();
3841       vsn.expand_by(MediumChunk * 2, MediumChunk * 2);
3842       vsn.get_chunk_vs(MediumChunk + SpecializedChunk); // Humongous chunks will be aligned up to MediumChunk + SpecializedChunk
3843       vsn.retire(&cm);
3844 
3845       const size_t words_left = MediumChunk * 2 - (MediumChunk + SpecializedChunk);
3846       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3847       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3848 
3849       assert(num_medium_chunks == 0, "should not get any medium chunks");
3850       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3851       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3852     }
3853 
3854   }
3855 
3856 #define assert_is_available_positive(word_size) \
3857   assert(vsn.is_available(word_size), \
3858     err_msg(#word_size ": " PTR_FORMAT " bytes were not available in " \
3859             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3860             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3861 
3862 #define assert_is_available_negative(word_size) \
3863   assert(!vsn.is_available(word_size), \
3864     err_msg(#word_size ": " PTR_FORMAT " bytes should not be available in " \
3865             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3866             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3867 
3868   static void test_is_available_positive() {
3869     // Reserve some memory.
3870     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3871     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3872 
3873     // Commit some memory.
3874     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3875     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3876     assert(expanded, "Failed to commit");
3877 
3878     // Check that is_available accepts the committed size.
3879     assert_is_available_positive(commit_word_size);
3880 
3881     // Check that is_available accepts half the committed size.
3882     size_t expand_word_size = commit_word_size / 2;
3883     assert_is_available_positive(expand_word_size);
3884   }
3885 
3886   static void test_is_available_negative() {
3887     // Reserve some memory.
3888     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3889     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3890 
3891     // Commit some memory.
3892     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3893     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3894     assert(expanded, "Failed to commit");
3895 
3896     // Check that is_available doesn't accept a too large size.
3897     size_t two_times_commit_word_size = commit_word_size * 2;
3898     assert_is_available_negative(two_times_commit_word_size);
3899   }
3900 
3901   static void test_is_available_overflow() {
3902     // Reserve some memory.
3903     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3904     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3905 
3906     // Commit some memory.
3907     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3908     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3909     assert(expanded, "Failed to commit");
3910 
3911     // Calculate a size that will overflow the virtual space size.
3912     void* virtual_space_max = (void*)(uintptr_t)-1;
3913     size_t bottom_to_max = pointer_delta(virtual_space_max, vsn.bottom(), 1);
3914     size_t overflow_size = bottom_to_max + BytesPerWord;
3915     size_t overflow_word_size = overflow_size / BytesPerWord;
3916 
3917     // Check that is_available can handle the overflow.
3918     assert_is_available_negative(overflow_word_size);
3919   }
3920 
3921   static void test_is_available() {
3922     TestVirtualSpaceNodeTest::test_is_available_positive();
3923     TestVirtualSpaceNodeTest::test_is_available_negative();
3924     TestVirtualSpaceNodeTest::test_is_available_overflow();
3925   }
3926 };
3927 
3928 void TestVirtualSpaceNode_test() {
3929   TestVirtualSpaceNodeTest::test();
3930   TestVirtualSpaceNodeTest::test_is_available();
3931 }
3932 #endif