1 /*
   2  * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 #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 chunk_word_size,
 535                            size_t suggested_commit_granularity);
 536 
 537   bool expand_node_by(VirtualSpaceNode* node,
 538                       size_t min_words,
 539                       size_t preferred_words);
 540 
 541   bool expand_by(size_t min_words,
 542                  size_t preferred_words);
 543 
 544   VirtualSpaceNode* current_virtual_space() {
 545     return _current_virtual_space;
 546   }
 547 
 548   bool is_class() const { return _is_class; }
 549 
 550   bool initialization_succeeded() { return _virtual_space_list != NULL; }
 551 
 552   size_t reserved_words()  { return _reserved_words; }
 553   size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
 554   size_t committed_words() { return _committed_words; }
 555   size_t committed_bytes() { return committed_words() * BytesPerWord; }
 556 
 557   void inc_reserved_words(size_t v);
 558   void dec_reserved_words(size_t v);
 559   void inc_committed_words(size_t v);
 560   void dec_committed_words(size_t v);
 561   void inc_virtual_space_count();
 562   void dec_virtual_space_count();
 563 
 564   bool contains(const void* ptr);
 565 
 566   // Unlink empty VirtualSpaceNodes and free it.
 567   void purge(ChunkManager* chunk_manager);
 568 
 569   void print_on(outputStream* st) const;
 570 
 571   class VirtualSpaceListIterator : public StackObj {
 572     VirtualSpaceNode* _virtual_spaces;
 573    public:
 574     VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
 575       _virtual_spaces(virtual_spaces) {}
 576 
 577     bool repeat() {
 578       return _virtual_spaces != NULL;
 579     }
 580 
 581     VirtualSpaceNode* get_next() {
 582       VirtualSpaceNode* result = _virtual_spaces;
 583       if (_virtual_spaces != NULL) {
 584         _virtual_spaces = _virtual_spaces->next();
 585       }
 586       return result;
 587     }
 588   };
 589 };
 590 
 591 class Metadebug : AllStatic {
 592   // Debugging support for Metaspaces
 593   static int _allocation_fail_alot_count;
 594 
 595  public:
 596 
 597   static void init_allocation_fail_alot_count();
 598 #ifdef ASSERT
 599   static bool test_metadata_failure();
 600 #endif
 601 };
 602 
 603 int Metadebug::_allocation_fail_alot_count = 0;
 604 
 605 //  SpaceManager - used by Metaspace to handle allocations
 606 class SpaceManager : public CHeapObj<mtClass> {
 607   friend class Metaspace;
 608   friend class Metadebug;
 609 
 610  private:
 611 
 612   // protects allocations
 613   Mutex* const _lock;
 614 
 615   // Type of metadata allocated.
 616   Metaspace::MetadataType _mdtype;
 617 
 618   // List of chunks in use by this SpaceManager.  Allocations
 619   // are done from the current chunk.  The list is used for deallocating
 620   // chunks when the SpaceManager is freed.
 621   Metachunk* _chunks_in_use[NumberOfInUseLists];
 622   Metachunk* _current_chunk;
 623 
 624   // Number of small chunks to allocate to a manager
 625   // If class space manager, small chunks are unlimited
 626   static uint const _small_chunk_limit;
 627 
 628   // Sum of all space in allocated chunks
 629   size_t _allocated_blocks_words;
 630 
 631   // Sum of all allocated chunks
 632   size_t _allocated_chunks_words;
 633   size_t _allocated_chunks_count;
 634 
 635   // Free lists of blocks are per SpaceManager since they
 636   // are assumed to be in chunks in use by the SpaceManager
 637   // and all chunks in use by a SpaceManager are freed when
 638   // the class loader using the SpaceManager is collected.
 639   BlockFreelist _block_freelists;
 640 
 641   // protects virtualspace and chunk expansions
 642   static const char*  _expand_lock_name;
 643   static const int    _expand_lock_rank;
 644   static Mutex* const _expand_lock;
 645 
 646  private:
 647   // Accessors
 648   Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
 649   void set_chunks_in_use(ChunkIndex index, Metachunk* v) {
 650     _chunks_in_use[index] = v;
 651   }
 652 
 653   BlockFreelist* block_freelists() const {
 654     return (BlockFreelist*) &_block_freelists;
 655   }
 656 
 657   Metaspace::MetadataType mdtype() { return _mdtype; }
 658 
 659   VirtualSpaceList* vs_list()   const { return Metaspace::get_space_list(_mdtype); }
 660   ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
 661 
 662   Metachunk* current_chunk() const { return _current_chunk; }
 663   void set_current_chunk(Metachunk* v) {
 664     _current_chunk = v;
 665   }
 666 
 667   Metachunk* find_current_chunk(size_t word_size);
 668 
 669   // Add chunk to the list of chunks in use
 670   void add_chunk(Metachunk* v, bool make_current);
 671   void retire_current_chunk();
 672 
 673   Mutex* lock() const { return _lock; }
 674 
 675   const char* chunk_size_name(ChunkIndex index) const;
 676 
 677  protected:
 678   void initialize();
 679 
 680  public:
 681   SpaceManager(Metaspace::MetadataType mdtype,
 682                Mutex* lock);
 683   ~SpaceManager();
 684 
 685   enum ChunkMultiples {
 686     MediumChunkMultiple = 4
 687   };
 688 
 689   static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; }
 690   static size_t small_chunk_size(bool is_class)       { return is_class ? ClassSmallChunk : SmallChunk; }
 691   static size_t medium_chunk_size(bool is_class)      { return is_class ? ClassMediumChunk : MediumChunk; }
 692 
 693   static size_t smallest_chunk_size(bool is_class)    { return specialized_chunk_size(is_class); }
 694 
 695   // Accessors
 696   bool is_class() const { return _mdtype == Metaspace::ClassType; }
 697 
 698   size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); }
 699   size_t small_chunk_size()       const { return small_chunk_size(is_class()); }
 700   size_t medium_chunk_size()      const { return medium_chunk_size(is_class()); }
 701 
 702   size_t smallest_chunk_size()    const { return smallest_chunk_size(is_class()); }
 703 
 704   size_t medium_chunk_bunch()     const { return medium_chunk_size() * MediumChunkMultiple; }
 705 
 706   size_t allocated_blocks_words() const { return _allocated_blocks_words; }
 707   size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; }
 708   size_t allocated_chunks_words() const { return _allocated_chunks_words; }
 709   size_t allocated_chunks_count() const { return _allocated_chunks_count; }
 710 
 711   bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
 712 
 713   static Mutex* expand_lock() { return _expand_lock; }
 714 
 715   // Increment the per Metaspace and global running sums for Metachunks
 716   // by the given size.  This is used when a Metachunk to added to
 717   // the in-use list.
 718   void inc_size_metrics(size_t words);
 719   // Increment the per Metaspace and global running sums Metablocks by the given
 720   // size.  This is used when a Metablock is allocated.
 721   void inc_used_metrics(size_t words);
 722   // Delete the portion of the running sums for this SpaceManager. That is,
 723   // the globals running sums for the Metachunks and Metablocks are
 724   // decremented for all the Metachunks in-use by this SpaceManager.
 725   void dec_total_from_size_metrics();
 726 
 727   // Adjust the initial chunk size to match one of the fixed chunk list sizes,
 728   // or return the unadjusted size if the requested size is humongous.
 729   static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space);
 730   size_t adjust_initial_chunk_size(size_t requested) const;
 731 
 732   // Get the initial chunks size for this metaspace type.
 733   size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const;
 734 
 735   size_t sum_capacity_in_chunks_in_use() const;
 736   size_t sum_used_in_chunks_in_use() const;
 737   size_t sum_free_in_chunks_in_use() const;
 738   size_t sum_waste_in_chunks_in_use() const;
 739   size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
 740 
 741   size_t sum_count_in_chunks_in_use();
 742   size_t sum_count_in_chunks_in_use(ChunkIndex i);
 743 
 744   Metachunk* get_new_chunk(size_t chunk_word_size);
 745 
 746   // Block allocation and deallocation.
 747   // Allocates a block from the current chunk
 748   MetaWord* allocate(size_t word_size);
 749 
 750   // Helper for allocations
 751   MetaWord* allocate_work(size_t word_size);
 752 
 753   // Returns a block to the per manager freelist
 754   void deallocate(MetaWord* p, size_t word_size);
 755 
 756   // Based on the allocation size and a minimum chunk size,
 757   // returned chunk size (for expanding space for chunk allocation).
 758   size_t calc_chunk_size(size_t allocation_word_size);
 759 
 760   // Called when an allocation from the current chunk fails.
 761   // Gets a new chunk (may require getting a new virtual space),
 762   // and allocates from that chunk.
 763   MetaWord* grow_and_allocate(size_t word_size);
 764 
 765   // Notify memory usage to MemoryService.
 766   void track_metaspace_memory_usage();
 767 
 768   // debugging support.
 769 
 770   void dump(outputStream* const out) const;
 771   void print_on(outputStream* st) const;
 772   void locked_print_chunks_in_use_on(outputStream* st) const;
 773 
 774   void verify();
 775   void verify_chunk_size(Metachunk* chunk);
 776   NOT_PRODUCT(void mangle_freed_chunks();)
 777 #ifdef ASSERT
 778   void verify_allocated_blocks_words();
 779 #endif
 780 
 781   size_t get_raw_word_size(size_t word_size) {
 782     size_t byte_size = word_size * BytesPerWord;
 783 
 784     size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
 785     raw_bytes_size = align_size_up(raw_bytes_size, Metachunk::object_alignment());
 786 
 787     size_t raw_word_size = raw_bytes_size / BytesPerWord;
 788     assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
 789 
 790     return raw_word_size;
 791   }
 792 };
 793 
 794 uint const SpaceManager::_small_chunk_limit = 4;
 795 
 796 const char* SpaceManager::_expand_lock_name =
 797   "SpaceManager chunk allocation lock";
 798 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
 799 Mutex* const SpaceManager::_expand_lock =
 800   new Mutex(SpaceManager::_expand_lock_rank,
 801             SpaceManager::_expand_lock_name,
 802             Mutex::_allow_vm_block_flag);
 803 
 804 void VirtualSpaceNode::inc_container_count() {
 805   assert_lock_strong(SpaceManager::expand_lock());
 806   _container_count++;
 807   assert(_container_count == container_count_slow(),
 808          err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
 809                  " container_count_slow() " SIZE_FORMAT,
 810                  _container_count, container_count_slow()));
 811 }
 812 
 813 void VirtualSpaceNode::dec_container_count() {
 814   assert_lock_strong(SpaceManager::expand_lock());
 815   _container_count--;
 816 }
 817 
 818 #ifdef ASSERT
 819 void VirtualSpaceNode::verify_container_count() {
 820   assert(_container_count == container_count_slow(),
 821     err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
 822             " container_count_slow() " SIZE_FORMAT, _container_count, container_count_slow()));
 823 }
 824 #endif
 825 
 826 // BlockFreelist methods
 827 
 828 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
 829 
 830 BlockFreelist::~BlockFreelist() {
 831   if (_dictionary != NULL) {
 832     if (Verbose && TraceMetadataChunkAllocation) {
 833       _dictionary->print_free_lists(gclog_or_tty);
 834     }
 835     delete _dictionary;
 836   }
 837 }
 838 
 839 void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
 840   Metablock* free_chunk = ::new (p) Metablock(word_size);
 841   if (dictionary() == NULL) {
 842    _dictionary = new BlockTreeDictionary();
 843   }
 844   dictionary()->return_chunk(free_chunk);
 845 }
 846 
 847 MetaWord* BlockFreelist::get_block(size_t word_size) {
 848   if (dictionary() == NULL) {
 849     return NULL;
 850   }
 851 
 852   if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 853     // Dark matter.  Too small for dictionary.
 854     return NULL;
 855   }
 856 
 857   Metablock* free_block =
 858     dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::atLeast);
 859   if (free_block == NULL) {
 860     return NULL;
 861   }
 862 
 863   const size_t block_size = free_block->size();
 864   if (block_size > WasteMultiplier * word_size) {
 865     return_block((MetaWord*)free_block, block_size);
 866     return NULL;
 867   }
 868 
 869   MetaWord* new_block = (MetaWord*)free_block;
 870   assert(block_size >= word_size, "Incorrect size of block from freelist");
 871   const size_t unused = block_size - word_size;
 872   if (unused >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 873     return_block(new_block + word_size, unused);
 874   }
 875 
 876   return new_block;
 877 }
 878 
 879 void BlockFreelist::print_on(outputStream* st) const {
 880   if (dictionary() == NULL) {
 881     return;
 882   }
 883   dictionary()->print_free_lists(st);
 884 }
 885 
 886 // VirtualSpaceNode methods
 887 
 888 VirtualSpaceNode::~VirtualSpaceNode() {
 889   _rs.release();
 890 #ifdef ASSERT
 891   size_t word_size = sizeof(*this) / BytesPerWord;
 892   Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
 893 #endif
 894 }
 895 
 896 size_t VirtualSpaceNode::used_words_in_vs() const {
 897   return pointer_delta(top(), bottom(), sizeof(MetaWord));
 898 }
 899 
 900 // Space committed in the VirtualSpace
 901 size_t VirtualSpaceNode::capacity_words_in_vs() const {
 902   return pointer_delta(end(), bottom(), sizeof(MetaWord));
 903 }
 904 
 905 size_t VirtualSpaceNode::free_words_in_vs() const {
 906   return pointer_delta(end(), top(), sizeof(MetaWord));
 907 }
 908 
 909 // Allocates the chunk from the virtual space only.
 910 // This interface is also used internally for debugging.  Not all
 911 // chunks removed here are necessarily used for allocation.
 912 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
 913   // Bottom of the new chunk
 914   MetaWord* chunk_limit = top();
 915   assert(chunk_limit != NULL, "Not safe to call this method");
 916 
 917   // The virtual spaces are always expanded by the
 918   // commit granularity to enforce the following condition.
 919   // Without this the is_available check will not work correctly.
 920   assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
 921       "The committed memory doesn't match the expanded memory.");
 922 
 923   if (!is_available(chunk_word_size)) {
 924     if (TraceMetadataChunkAllocation) {
 925       gclog_or_tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
 926       // Dump some information about the virtual space that is nearly full
 927       print_on(gclog_or_tty);
 928     }
 929     return NULL;
 930   }
 931 
 932   // Take the space  (bump top on the current virtual space).
 933   inc_top(chunk_word_size);
 934 
 935   // Initialize the chunk
 936   Metachunk* result = ::new (chunk_limit) Metachunk(chunk_word_size, this);
 937   return result;
 938 }
 939 
 940 
 941 // Expand the virtual space (commit more of the reserved space)
 942 bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
 943   size_t min_bytes = min_words * BytesPerWord;
 944   size_t preferred_bytes = preferred_words * BytesPerWord;
 945 
 946   size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
 947 
 948   if (uncommitted < min_bytes) {
 949     return false;
 950   }
 951 
 952   size_t commit = MIN2(preferred_bytes, uncommitted);
 953   bool result = virtual_space()->expand_by(commit, false);
 954 
 955   assert(result, "Failed to commit memory");
 956 
 957   return result;
 958 }
 959 
 960 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
 961   assert_lock_strong(SpaceManager::expand_lock());
 962   Metachunk* result = take_from_committed(chunk_word_size);
 963   if (result != NULL) {
 964     inc_container_count();
 965   }
 966   return result;
 967 }
 968 
 969 bool VirtualSpaceNode::initialize() {
 970 
 971   if (!_rs.is_reserved()) {
 972     return false;
 973   }
 974 
 975   // These are necessary restriction to make sure that the virtual space always
 976   // grows in steps of Metaspace::commit_alignment(). If both base and size are
 977   // aligned only the middle alignment of the VirtualSpace is used.
 978   assert_is_ptr_aligned(_rs.base(), Metaspace::commit_alignment());
 979   assert_is_size_aligned(_rs.size(), Metaspace::commit_alignment());
 980 
 981   // ReservedSpaces marked as special will have the entire memory
 982   // pre-committed. Setting a committed size will make sure that
 983   // committed_size and actual_committed_size agrees.
 984   size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
 985 
 986   bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
 987                                             Metaspace::commit_alignment());
 988   if (result) {
 989     assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
 990         "Checking that the pre-committed memory was registered by the VirtualSpace");
 991 
 992     set_top((MetaWord*)virtual_space()->low());
 993     set_reserved(MemRegion((HeapWord*)_rs.base(),
 994                  (HeapWord*)(_rs.base() + _rs.size())));
 995 
 996     assert(reserved()->start() == (HeapWord*) _rs.base(),
 997       err_msg("Reserved start was not set properly " PTR_FORMAT
 998         " != " PTR_FORMAT, reserved()->start(), _rs.base()));
 999     assert(reserved()->word_size() == _rs.size() / BytesPerWord,
1000       err_msg("Reserved size was not set properly " SIZE_FORMAT
1001         " != " SIZE_FORMAT, reserved()->word_size(),
1002         _rs.size() / BytesPerWord));
1003   }
1004 
1005   return result;
1006 }
1007 
1008 void VirtualSpaceNode::print_on(outputStream* st) const {
1009   size_t used = used_words_in_vs();
1010   size_t capacity = capacity_words_in_vs();
1011   VirtualSpace* vs = virtual_space();
1012   st->print_cr("   space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
1013            "[" PTR_FORMAT ", " PTR_FORMAT ", "
1014            PTR_FORMAT ", " PTR_FORMAT ")",
1015            vs, capacity / K,
1016            capacity == 0 ? 0 : used * 100 / capacity,
1017            bottom(), top(), end(),
1018            vs->high_boundary());
1019 }
1020 
1021 #ifdef ASSERT
1022 void VirtualSpaceNode::mangle() {
1023   size_t word_size = capacity_words_in_vs();
1024   Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
1025 }
1026 #endif // ASSERT
1027 
1028 // VirtualSpaceList methods
1029 // Space allocated from the VirtualSpace
1030 
1031 VirtualSpaceList::~VirtualSpaceList() {
1032   VirtualSpaceListIterator iter(virtual_space_list());
1033   while (iter.repeat()) {
1034     VirtualSpaceNode* vsl = iter.get_next();
1035     delete vsl;
1036   }
1037 }
1038 
1039 void VirtualSpaceList::inc_reserved_words(size_t v) {
1040   assert_lock_strong(SpaceManager::expand_lock());
1041   _reserved_words = _reserved_words + v;
1042 }
1043 void VirtualSpaceList::dec_reserved_words(size_t v) {
1044   assert_lock_strong(SpaceManager::expand_lock());
1045   _reserved_words = _reserved_words - v;
1046 }
1047 
1048 #define assert_committed_below_limit()                             \
1049   assert(MetaspaceAux::committed_bytes() <= MaxMetaspaceSize,      \
1050       err_msg("Too much committed memory. Committed: " SIZE_FORMAT \
1051               " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
1052           MetaspaceAux::committed_bytes(), MaxMetaspaceSize));
1053 
1054 void VirtualSpaceList::inc_committed_words(size_t v) {
1055   assert_lock_strong(SpaceManager::expand_lock());
1056   _committed_words = _committed_words + v;
1057 
1058   assert_committed_below_limit();
1059 }
1060 void VirtualSpaceList::dec_committed_words(size_t v) {
1061   assert_lock_strong(SpaceManager::expand_lock());
1062   _committed_words = _committed_words - v;
1063 
1064   assert_committed_below_limit();
1065 }
1066 
1067 void VirtualSpaceList::inc_virtual_space_count() {
1068   assert_lock_strong(SpaceManager::expand_lock());
1069   _virtual_space_count++;
1070 }
1071 void VirtualSpaceList::dec_virtual_space_count() {
1072   assert_lock_strong(SpaceManager::expand_lock());
1073   _virtual_space_count--;
1074 }
1075 
1076 void ChunkManager::remove_chunk(Metachunk* chunk) {
1077   size_t word_size = chunk->word_size();
1078   ChunkIndex index = list_index(word_size);
1079   if (index != HumongousIndex) {
1080     free_chunks(index)->remove_chunk(chunk);
1081   } else {
1082     humongous_dictionary()->remove_chunk(chunk);
1083   }
1084 
1085   // Chunk is being removed from the chunks free list.
1086   dec_free_chunks_total(chunk->word_size());
1087 }
1088 
1089 // Walk the list of VirtualSpaceNodes and delete
1090 // nodes with a 0 container_count.  Remove Metachunks in
1091 // the node from their respective freelists.
1092 void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
1093   assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work");
1094   assert_lock_strong(SpaceManager::expand_lock());
1095   // Don't use a VirtualSpaceListIterator because this
1096   // list is being changed and a straightforward use of an iterator is not safe.
1097   VirtualSpaceNode* purged_vsl = NULL;
1098   VirtualSpaceNode* prev_vsl = virtual_space_list();
1099   VirtualSpaceNode* next_vsl = prev_vsl;
1100   while (next_vsl != NULL) {
1101     VirtualSpaceNode* vsl = next_vsl;
1102     next_vsl = vsl->next();
1103     // Don't free the current virtual space since it will likely
1104     // be needed soon.
1105     if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
1106       // Unlink it from the list
1107       if (prev_vsl == vsl) {
1108         // This is the case of the current node being the first node.
1109         assert(vsl == virtual_space_list(), "Expected to be the first node");
1110         set_virtual_space_list(vsl->next());
1111       } else {
1112         prev_vsl->set_next(vsl->next());
1113       }
1114 
1115       vsl->purge(chunk_manager);
1116       dec_reserved_words(vsl->reserved_words());
1117       dec_committed_words(vsl->committed_words());
1118       dec_virtual_space_count();
1119       purged_vsl = vsl;
1120       delete vsl;
1121     } else {
1122       prev_vsl = vsl;
1123     }
1124   }
1125 #ifdef ASSERT
1126   if (purged_vsl != NULL) {
1127     // List should be stable enough to use an iterator here.
1128     VirtualSpaceListIterator iter(virtual_space_list());
1129     while (iter.repeat()) {
1130       VirtualSpaceNode* vsl = iter.get_next();
1131       assert(vsl != purged_vsl, "Purge of vsl failed");
1132     }
1133   }
1134 #endif
1135 }
1136 
1137 
1138 // This function looks at the mmap regions in the metaspace without locking.
1139 // The chunks are added with store ordering and not deleted except for at
1140 // unloading time during a safepoint.
1141 bool VirtualSpaceList::contains(const void* ptr) {
1142   // List should be stable enough to use an iterator here because removing virtual
1143   // space nodes is only allowed at a safepoint.
1144   VirtualSpaceListIterator iter(virtual_space_list());
1145   while (iter.repeat()) {
1146     VirtualSpaceNode* vsn = iter.get_next();
1147     if (vsn->contains(ptr)) {
1148       return true;
1149     }
1150   }
1151   return false;
1152 }
1153 
1154 void VirtualSpaceList::retire_current_virtual_space() {
1155   assert_lock_strong(SpaceManager::expand_lock());
1156 
1157   VirtualSpaceNode* vsn = current_virtual_space();
1158 
1159   ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() :
1160                                   Metaspace::chunk_manager_metadata();
1161 
1162   vsn->retire(cm);
1163 }
1164 
1165 void VirtualSpaceNode::retire(ChunkManager* chunk_manager) {
1166   for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) {
1167     ChunkIndex index = (ChunkIndex)i;
1168     size_t chunk_size = chunk_manager->free_chunks(index)->size();
1169 
1170     while (free_words_in_vs() >= chunk_size) {
1171       DEBUG_ONLY(verify_container_count();)
1172       Metachunk* chunk = get_chunk_vs(chunk_size);
1173       assert(chunk != NULL, "allocation should have been successful");
1174 
1175       chunk_manager->return_chunks(index, chunk);
1176       chunk_manager->inc_free_chunks_total(chunk_size);
1177       DEBUG_ONLY(verify_container_count();)
1178     }
1179   }
1180   assert(free_words_in_vs() == 0, "should be empty now");
1181 }
1182 
1183 VirtualSpaceList::VirtualSpaceList(size_t word_size) :
1184                                    _is_class(false),
1185                                    _virtual_space_list(NULL),
1186                                    _current_virtual_space(NULL),
1187                                    _reserved_words(0),
1188                                    _committed_words(0),
1189                                    _virtual_space_count(0) {
1190   MutexLockerEx cl(SpaceManager::expand_lock(),
1191                    Mutex::_no_safepoint_check_flag);
1192   create_new_virtual_space(word_size);
1193 }
1194 
1195 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
1196                                    _is_class(true),
1197                                    _virtual_space_list(NULL),
1198                                    _current_virtual_space(NULL),
1199                                    _reserved_words(0),
1200                                    _committed_words(0),
1201                                    _virtual_space_count(0) {
1202   MutexLockerEx cl(SpaceManager::expand_lock(),
1203                    Mutex::_no_safepoint_check_flag);
1204   VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
1205   bool succeeded = class_entry->initialize();
1206   if (succeeded) {
1207     link_vs(class_entry);
1208   }
1209 }
1210 
1211 size_t VirtualSpaceList::free_bytes() {
1212   return virtual_space_list()->free_words_in_vs() * BytesPerWord;
1213 }
1214 
1215 // Allocate another meta virtual space and add it to the list.
1216 bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
1217   assert_lock_strong(SpaceManager::expand_lock());
1218 
1219   if (is_class()) {
1220     assert(false, "We currently don't support more than one VirtualSpace for"
1221                   " the compressed class space. The initialization of the"
1222                   " CCS uses another code path and should not hit this path.");
1223     return false;
1224   }
1225 
1226   if (vs_word_size == 0) {
1227     assert(false, "vs_word_size should always be at least _reserve_alignment large.");
1228     return false;
1229   }
1230 
1231   // Reserve the space
1232   size_t vs_byte_size = vs_word_size * BytesPerWord;
1233   assert_is_size_aligned(vs_byte_size, Metaspace::reserve_alignment());
1234 
1235   // Allocate the meta virtual space and initialize it.
1236   VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
1237   if (!new_entry->initialize()) {
1238     delete new_entry;
1239     return false;
1240   } else {
1241     assert(new_entry->reserved_words() == vs_word_size,
1242         "Reserved memory size differs from requested memory size");
1243     // ensure lock-free iteration sees fully initialized node
1244     OrderAccess::storestore();
1245     link_vs(new_entry);
1246     return true;
1247   }
1248 }
1249 
1250 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
1251   if (virtual_space_list() == NULL) {
1252       set_virtual_space_list(new_entry);
1253   } else {
1254     current_virtual_space()->set_next(new_entry);
1255   }
1256   set_current_virtual_space(new_entry);
1257   inc_reserved_words(new_entry->reserved_words());
1258   inc_committed_words(new_entry->committed_words());
1259   inc_virtual_space_count();
1260 #ifdef ASSERT
1261   new_entry->mangle();
1262 #endif
1263   if (TraceMetavirtualspaceAllocation && Verbose) {
1264     VirtualSpaceNode* vsl = current_virtual_space();
1265     vsl->print_on(gclog_or_tty);
1266   }
1267 }
1268 
1269 bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
1270                                       size_t min_words,
1271                                       size_t preferred_words) {
1272   size_t before = node->committed_words();
1273 
1274   bool result = node->expand_by(min_words, preferred_words);
1275 
1276   size_t after = node->committed_words();
1277 
1278   // after and before can be the same if the memory was pre-committed.
1279   assert(after >= before, "Inconsistency");
1280   inc_committed_words(after - before);
1281 
1282   return result;
1283 }
1284 
1285 bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
1286   assert_is_size_aligned(min_words,       Metaspace::commit_alignment_words());
1287   assert_is_size_aligned(preferred_words, Metaspace::commit_alignment_words());
1288   assert(min_words <= preferred_words, "Invalid arguments");
1289 
1290   if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
1291     return  false;
1292   }
1293 
1294   size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
1295   if (allowed_expansion_words < min_words) {
1296     return false;
1297   }
1298 
1299   size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
1300 
1301   // Commit more memory from the the current virtual space.
1302   bool vs_expanded = expand_node_by(current_virtual_space(),
1303                                     min_words,
1304                                     max_expansion_words);
1305   if (vs_expanded) {
1306     return true;
1307   }
1308   retire_current_virtual_space();
1309 
1310   // Get another virtual space.
1311   size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
1312   grow_vs_words = align_size_up(grow_vs_words, Metaspace::reserve_alignment_words());
1313 
1314   if (create_new_virtual_space(grow_vs_words)) {
1315     if (current_virtual_space()->is_pre_committed()) {
1316       // The memory was pre-committed, so we are done here.
1317       assert(min_words <= current_virtual_space()->committed_words(),
1318           "The new VirtualSpace was pre-committed, so it"
1319           "should be large enough to fit the alloc request.");
1320       return true;
1321     }
1322 
1323     return expand_node_by(current_virtual_space(),
1324                           min_words,
1325                           max_expansion_words);
1326   }
1327 
1328   return false;
1329 }
1330 
1331 Metachunk* VirtualSpaceList::get_new_chunk(size_t chunk_word_size, size_t suggested_commit_granularity) {
1332 
1333   // Allocate a chunk out of the current virtual space.
1334   Metachunk* next = current_virtual_space()->get_chunk_vs(chunk_word_size);
1335 
1336   if (next != NULL) {
1337     return next;
1338   }
1339 
1340   // The expand amount is currently only determined by the requested sizes
1341   // and not how much committed memory is left in the current virtual space.
1342 
1343   size_t min_word_size       = align_size_up(chunk_word_size,              Metaspace::commit_alignment_words());
1344   size_t preferred_word_size = align_size_up(suggested_commit_granularity, Metaspace::commit_alignment_words());
1345   if (min_word_size >= preferred_word_size) {
1346     // Can happen when humongous chunks are allocated.
1347     preferred_word_size = min_word_size;
1348   }
1349 
1350   bool expanded = expand_by(min_word_size, preferred_word_size);
1351   if (expanded) {
1352     next = current_virtual_space()->get_chunk_vs(chunk_word_size);
1353     assert(next != NULL, "The allocation was expected to succeed after the expansion");
1354   }
1355 
1356    return next;
1357 }
1358 
1359 void VirtualSpaceList::print_on(outputStream* st) const {
1360   if (TraceMetadataChunkAllocation && Verbose) {
1361     VirtualSpaceListIterator iter(virtual_space_list());
1362     while (iter.repeat()) {
1363       VirtualSpaceNode* node = iter.get_next();
1364       node->print_on(st);
1365     }
1366   }
1367 }
1368 
1369 // MetaspaceGC methods
1370 
1371 // VM_CollectForMetadataAllocation is the vm operation used to GC.
1372 // Within the VM operation after the GC the attempt to allocate the metadata
1373 // should succeed.  If the GC did not free enough space for the metaspace
1374 // allocation, the HWM is increased so that another virtualspace will be
1375 // allocated for the metadata.  With perm gen the increase in the perm
1376 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion.  The
1377 // metaspace policy uses those as the small and large steps for the HWM.
1378 //
1379 // After the GC the compute_new_size() for MetaspaceGC is called to
1380 // resize the capacity of the metaspaces.  The current implementation
1381 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
1382 // to resize the Java heap by some GC's.  New flags can be implemented
1383 // if really needed.  MinMetaspaceFreeRatio is used to calculate how much
1384 // free space is desirable in the metaspace capacity to decide how much
1385 // to increase the HWM.  MaxMetaspaceFreeRatio is used to decide how much
1386 // free space is desirable in the metaspace capacity before decreasing
1387 // the HWM.
1388 
1389 // Calculate the amount to increase the high water mark (HWM).
1390 // Increase by a minimum amount (MinMetaspaceExpansion) so that
1391 // another expansion is not requested too soon.  If that is not
1392 // enough to satisfy the allocation, increase by MaxMetaspaceExpansion.
1393 // If that is still not enough, expand by the size of the allocation
1394 // plus some.
1395 size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) {
1396   size_t min_delta = MinMetaspaceExpansion;
1397   size_t max_delta = MaxMetaspaceExpansion;
1398   size_t delta = align_size_up(bytes, Metaspace::commit_alignment());
1399 
1400   if (delta <= min_delta) {
1401     delta = min_delta;
1402   } else if (delta <= max_delta) {
1403     // Don't want to hit the high water mark on the next
1404     // allocation so make the delta greater than just enough
1405     // for this allocation.
1406     delta = max_delta;
1407   } else {
1408     // This allocation is large but the next ones are probably not
1409     // so increase by the minimum.
1410     delta = delta + min_delta;
1411   }
1412 
1413   assert_is_size_aligned(delta, Metaspace::commit_alignment());
1414 
1415   return delta;
1416 }
1417 
1418 size_t MetaspaceGC::capacity_until_GC() {
1419   size_t value = (size_t)OrderAccess::load_ptr_acquire(&_capacity_until_GC);
1420   assert(value >= MetaspaceSize, "Not initialied properly?");
1421   return value;
1422 }
1423 
1424 bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) {
1425   assert_is_size_aligned(v, Metaspace::commit_alignment());
1426 
1427   size_t capacity_until_GC = (size_t) _capacity_until_GC;
1428   size_t new_value = capacity_until_GC + v;
1429 
1430   if (new_value < capacity_until_GC) {
1431     // The addition wrapped around, set new_value to aligned max value.
1432     new_value = align_size_down(max_uintx, Metaspace::commit_alignment());
1433   }
1434 
1435   intptr_t expected = (intptr_t) capacity_until_GC;
1436   intptr_t actual = Atomic::cmpxchg_ptr((intptr_t) new_value, &_capacity_until_GC, expected);
1437 
1438   if (expected != actual) {
1439     return false;
1440   }
1441 
1442   if (new_cap_until_GC != NULL) {
1443     *new_cap_until_GC = new_value;
1444   }
1445   if (old_cap_until_GC != NULL) {
1446     *old_cap_until_GC = capacity_until_GC;
1447   }
1448   return true;
1449 }
1450 
1451 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
1452   assert_is_size_aligned(v, Metaspace::commit_alignment());
1453 
1454   return (size_t)Atomic::add_ptr(-(intptr_t)v, &_capacity_until_GC);
1455 }
1456 
1457 void MetaspaceGC::initialize() {
1458   // Set the high-water mark to MaxMetapaceSize during VM initializaton since
1459   // we can't do a GC during initialization.
1460   _capacity_until_GC = MaxMetaspaceSize;
1461 }
1462 
1463 void MetaspaceGC::post_initialize() {
1464   // Reset the high-water mark once the VM initialization is done.
1465   _capacity_until_GC = MAX2(MetaspaceAux::committed_bytes(), MetaspaceSize);
1466 }
1467 
1468 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
1469   // Check if the compressed class space is full.
1470   if (is_class && Metaspace::using_class_space()) {
1471     size_t class_committed = MetaspaceAux::committed_bytes(Metaspace::ClassType);
1472     if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
1473       return false;
1474     }
1475   }
1476 
1477   // Check if the user has imposed a limit on the metaspace memory.
1478   size_t committed_bytes = MetaspaceAux::committed_bytes();
1479   if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
1480     return false;
1481   }
1482 
1483   return true;
1484 }
1485 
1486 size_t MetaspaceGC::allowed_expansion() {
1487   size_t committed_bytes = MetaspaceAux::committed_bytes();
1488   size_t capacity_until_gc = capacity_until_GC();
1489 
1490   assert(capacity_until_gc >= committed_bytes,
1491         err_msg("capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT,
1492                 capacity_until_gc, committed_bytes));
1493 
1494   size_t left_until_max  = MaxMetaspaceSize - committed_bytes;
1495   size_t left_until_GC = capacity_until_gc - committed_bytes;
1496   size_t left_to_commit = MIN2(left_until_GC, left_until_max);
1497 
1498   return left_to_commit / BytesPerWord;
1499 }
1500 
1501 void MetaspaceGC::compute_new_size() {
1502   assert(_shrink_factor <= 100, "invalid shrink factor");
1503   uint current_shrink_factor = _shrink_factor;
1504   _shrink_factor = 0;
1505 
1506   // Using committed_bytes() for used_after_gc is an overestimation, since the
1507   // chunk free lists are included in committed_bytes() and the memory in an
1508   // un-fragmented chunk free list is available for future allocations.
1509   // However, if the chunk free lists becomes fragmented, then the memory may
1510   // not be available for future allocations and the memory is therefore "in use".
1511   // Including the chunk free lists in the definition of "in use" is therefore
1512   // necessary. Not including the chunk free lists can cause capacity_until_GC to
1513   // shrink below committed_bytes() and this has caused serious bugs in the past.
1514   const size_t used_after_gc = MetaspaceAux::committed_bytes();
1515   const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
1516 
1517   const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
1518   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
1519 
1520   const double min_tmp = used_after_gc / maximum_used_percentage;
1521   size_t minimum_desired_capacity =
1522     (size_t)MIN2(min_tmp, double(max_uintx));
1523   // Don't shrink less than the initial generation size
1524   minimum_desired_capacity = MAX2(minimum_desired_capacity,
1525                                   MetaspaceSize);
1526 
1527   if (PrintGCDetails && Verbose) {
1528     gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
1529     gclog_or_tty->print_cr("  "
1530                   "  minimum_free_percentage: %6.2f"
1531                   "  maximum_used_percentage: %6.2f",
1532                   minimum_free_percentage,
1533                   maximum_used_percentage);
1534     gclog_or_tty->print_cr("  "
1535                   "   used_after_gc       : %6.1fKB",
1536                   used_after_gc / (double) K);
1537   }
1538 
1539 
1540   size_t shrink_bytes = 0;
1541   if (capacity_until_GC < minimum_desired_capacity) {
1542     // If we have less capacity below the metaspace HWM, then
1543     // increment the HWM.
1544     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
1545     expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
1546     // Don't expand unless it's significant
1547     if (expand_bytes >= MinMetaspaceExpansion) {
1548       size_t new_capacity_until_GC = 0;
1549       bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC);
1550       assert(succeeded, "Should always succesfully increment HWM when at safepoint");
1551 
1552       Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1553                                                new_capacity_until_GC,
1554                                                MetaspaceGCThresholdUpdater::ComputeNewSize);
1555       if (PrintGCDetails && Verbose) {
1556         gclog_or_tty->print_cr("    expanding:"
1557                       "  minimum_desired_capacity: %6.1fKB"
1558                       "  expand_bytes: %6.1fKB"
1559                       "  MinMetaspaceExpansion: %6.1fKB"
1560                       "  new metaspace HWM:  %6.1fKB",
1561                       minimum_desired_capacity / (double) K,
1562                       expand_bytes / (double) K,
1563                       MinMetaspaceExpansion / (double) K,
1564                       new_capacity_until_GC / (double) K);
1565       }
1566     }
1567     return;
1568   }
1569 
1570   // No expansion, now see if we want to shrink
1571   // We would never want to shrink more than this
1572   size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity;
1573   assert(max_shrink_bytes >= 0, err_msg("max_shrink_bytes " SIZE_FORMAT,
1574     max_shrink_bytes));
1575 
1576   // Should shrinking be considered?
1577   if (MaxMetaspaceFreeRatio < 100) {
1578     const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0;
1579     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
1580     const double max_tmp = used_after_gc / minimum_used_percentage;
1581     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
1582     maximum_desired_capacity = MAX2(maximum_desired_capacity,
1583                                     MetaspaceSize);
1584     if (PrintGCDetails && Verbose) {
1585       gclog_or_tty->print_cr("  "
1586                              "  maximum_free_percentage: %6.2f"
1587                              "  minimum_used_percentage: %6.2f",
1588                              maximum_free_percentage,
1589                              minimum_used_percentage);
1590       gclog_or_tty->print_cr("  "
1591                              "  minimum_desired_capacity: %6.1fKB"
1592                              "  maximum_desired_capacity: %6.1fKB",
1593                              minimum_desired_capacity / (double) K,
1594                              maximum_desired_capacity / (double) K);
1595     }
1596 
1597     assert(minimum_desired_capacity <= maximum_desired_capacity,
1598            "sanity check");
1599 
1600     if (capacity_until_GC > maximum_desired_capacity) {
1601       // Capacity too large, compute shrinking size
1602       shrink_bytes = capacity_until_GC - maximum_desired_capacity;
1603       // We don't want shrink all the way back to initSize if people call
1604       // System.gc(), because some programs do that between "phases" and then
1605       // we'd just have to grow the heap up again for the next phase.  So we
1606       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
1607       // on the third call, and 100% by the fourth call.  But if we recompute
1608       // size without shrinking, it goes back to 0%.
1609       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
1610 
1611       shrink_bytes = align_size_down(shrink_bytes, Metaspace::commit_alignment());
1612 
1613       assert(shrink_bytes <= max_shrink_bytes,
1614         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
1615           shrink_bytes, max_shrink_bytes));
1616       if (current_shrink_factor == 0) {
1617         _shrink_factor = 10;
1618       } else {
1619         _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
1620       }
1621       if (PrintGCDetails && Verbose) {
1622         gclog_or_tty->print_cr("  "
1623                       "  shrinking:"
1624                       "  initSize: %.1fK"
1625                       "  maximum_desired_capacity: %.1fK",
1626                       MetaspaceSize / (double) K,
1627                       maximum_desired_capacity / (double) K);
1628         gclog_or_tty->print_cr("  "
1629                       "  shrink_bytes: %.1fK"
1630                       "  current_shrink_factor: %d"
1631                       "  new shrink factor: %d"
1632                       "  MinMetaspaceExpansion: %.1fK",
1633                       shrink_bytes / (double) K,
1634                       current_shrink_factor,
1635                       _shrink_factor,
1636                       MinMetaspaceExpansion / (double) K);
1637       }
1638     }
1639   }
1640 
1641   // Don't shrink unless it's significant
1642   if (shrink_bytes >= MinMetaspaceExpansion &&
1643       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
1644     size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
1645     Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1646                                              new_capacity_until_GC,
1647                                              MetaspaceGCThresholdUpdater::ComputeNewSize);
1648   }
1649 }
1650 
1651 // Metadebug methods
1652 
1653 void Metadebug::init_allocation_fail_alot_count() {
1654   if (MetadataAllocationFailALot) {
1655     _allocation_fail_alot_count =
1656       1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
1657   }
1658 }
1659 
1660 #ifdef ASSERT
1661 bool Metadebug::test_metadata_failure() {
1662   if (MetadataAllocationFailALot &&
1663       Threads::is_vm_complete()) {
1664     if (_allocation_fail_alot_count > 0) {
1665       _allocation_fail_alot_count--;
1666     } else {
1667       if (TraceMetadataChunkAllocation && Verbose) {
1668         gclog_or_tty->print_cr("Metadata allocation failing for "
1669                                "MetadataAllocationFailALot");
1670       }
1671       init_allocation_fail_alot_count();
1672       return true;
1673     }
1674   }
1675   return false;
1676 }
1677 #endif
1678 
1679 // ChunkManager methods
1680 
1681 size_t ChunkManager::free_chunks_total_words() {
1682   return _free_chunks_total;
1683 }
1684 
1685 size_t ChunkManager::free_chunks_total_bytes() {
1686   return free_chunks_total_words() * BytesPerWord;
1687 }
1688 
1689 size_t ChunkManager::free_chunks_count() {
1690 #ifdef ASSERT
1691   if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1692     MutexLockerEx cl(SpaceManager::expand_lock(),
1693                      Mutex::_no_safepoint_check_flag);
1694     // This lock is only needed in debug because the verification
1695     // of the _free_chunks_totals walks the list of free chunks
1696     slow_locked_verify_free_chunks_count();
1697   }
1698 #endif
1699   return _free_chunks_count;
1700 }
1701 
1702 void ChunkManager::locked_verify_free_chunks_total() {
1703   assert_lock_strong(SpaceManager::expand_lock());
1704   assert(sum_free_chunks() == _free_chunks_total,
1705     err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
1706            " same as sum " SIZE_FORMAT, _free_chunks_total,
1707            sum_free_chunks()));
1708 }
1709 
1710 void ChunkManager::verify_free_chunks_total() {
1711   MutexLockerEx cl(SpaceManager::expand_lock(),
1712                      Mutex::_no_safepoint_check_flag);
1713   locked_verify_free_chunks_total();
1714 }
1715 
1716 void ChunkManager::locked_verify_free_chunks_count() {
1717   assert_lock_strong(SpaceManager::expand_lock());
1718   assert(sum_free_chunks_count() == _free_chunks_count,
1719     err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
1720            " same as sum " SIZE_FORMAT, _free_chunks_count,
1721            sum_free_chunks_count()));
1722 }
1723 
1724 void ChunkManager::verify_free_chunks_count() {
1725 #ifdef ASSERT
1726   MutexLockerEx cl(SpaceManager::expand_lock(),
1727                      Mutex::_no_safepoint_check_flag);
1728   locked_verify_free_chunks_count();
1729 #endif
1730 }
1731 
1732 void ChunkManager::verify() {
1733   MutexLockerEx cl(SpaceManager::expand_lock(),
1734                      Mutex::_no_safepoint_check_flag);
1735   locked_verify();
1736 }
1737 
1738 void ChunkManager::locked_verify() {
1739   locked_verify_free_chunks_count();
1740   locked_verify_free_chunks_total();
1741 }
1742 
1743 void ChunkManager::locked_print_free_chunks(outputStream* st) {
1744   assert_lock_strong(SpaceManager::expand_lock());
1745   st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1746                 _free_chunks_total, _free_chunks_count);
1747 }
1748 
1749 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
1750   assert_lock_strong(SpaceManager::expand_lock());
1751   st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1752                 sum_free_chunks(), sum_free_chunks_count());
1753 }
1754 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
1755   return &_free_chunks[index];
1756 }
1757 
1758 // These methods that sum the free chunk lists are used in printing
1759 // methods that are used in product builds.
1760 size_t ChunkManager::sum_free_chunks() {
1761   assert_lock_strong(SpaceManager::expand_lock());
1762   size_t result = 0;
1763   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1764     ChunkList* list = free_chunks(i);
1765 
1766     if (list == NULL) {
1767       continue;
1768     }
1769 
1770     result = result + list->count() * list->size();
1771   }
1772   result = result + humongous_dictionary()->total_size();
1773   return result;
1774 }
1775 
1776 size_t ChunkManager::sum_free_chunks_count() {
1777   assert_lock_strong(SpaceManager::expand_lock());
1778   size_t count = 0;
1779   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1780     ChunkList* list = free_chunks(i);
1781     if (list == NULL) {
1782       continue;
1783     }
1784     count = count + list->count();
1785   }
1786   count = count + humongous_dictionary()->total_free_blocks();
1787   return count;
1788 }
1789 
1790 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
1791   ChunkIndex index = list_index(word_size);
1792   assert(index < HumongousIndex, "No humongous list");
1793   return free_chunks(index);
1794 }
1795 
1796 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
1797   assert_lock_strong(SpaceManager::expand_lock());
1798 
1799   slow_locked_verify();
1800 
1801   Metachunk* chunk = NULL;
1802   if (list_index(word_size) != HumongousIndex) {
1803     ChunkList* free_list = find_free_chunks_list(word_size);
1804     assert(free_list != NULL, "Sanity check");
1805 
1806     chunk = free_list->head();
1807 
1808     if (chunk == NULL) {
1809       return NULL;
1810     }
1811 
1812     // Remove the chunk as the head of the list.
1813     free_list->remove_chunk(chunk);
1814 
1815     if (TraceMetadataChunkAllocation && Verbose) {
1816       gclog_or_tty->print_cr("ChunkManager::free_chunks_get: free_list "
1817                              PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
1818                              free_list, chunk, chunk->word_size());
1819     }
1820   } else {
1821     chunk = humongous_dictionary()->get_chunk(
1822       word_size,
1823       FreeBlockDictionary<Metachunk>::atLeast);
1824 
1825     if (chunk == NULL) {
1826       return NULL;
1827     }
1828 
1829     if (TraceMetadataHumongousAllocation) {
1830       size_t waste = chunk->word_size() - word_size;
1831       gclog_or_tty->print_cr("Free list allocate humongous chunk size "
1832                              SIZE_FORMAT " for requested size " SIZE_FORMAT
1833                              " waste " SIZE_FORMAT,
1834                              chunk->word_size(), word_size, waste);
1835     }
1836   }
1837 
1838   // Chunk is being removed from the chunks free list.
1839   dec_free_chunks_total(chunk->word_size());
1840 
1841   // Remove it from the links to this freelist
1842   chunk->set_next(NULL);
1843   chunk->set_prev(NULL);
1844 #ifdef ASSERT
1845   // Chunk is no longer on any freelist. Setting to false make container_count_slow()
1846   // work.
1847   chunk->set_is_tagged_free(false);
1848 #endif
1849   chunk->container()->inc_container_count();
1850 
1851   slow_locked_verify();
1852   return chunk;
1853 }
1854 
1855 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
1856   assert_lock_strong(SpaceManager::expand_lock());
1857   slow_locked_verify();
1858 
1859   // Take from the beginning of the list
1860   Metachunk* chunk = free_chunks_get(word_size);
1861   if (chunk == NULL) {
1862     return NULL;
1863   }
1864 
1865   assert((word_size <= chunk->word_size()) ||
1866          list_index(chunk->word_size() == HumongousIndex),
1867          "Non-humongous variable sized chunk");
1868   if (TraceMetadataChunkAllocation) {
1869     size_t list_count;
1870     if (list_index(word_size) < HumongousIndex) {
1871       ChunkList* list = find_free_chunks_list(word_size);
1872       list_count = list->count();
1873     } else {
1874       list_count = humongous_dictionary()->total_count();
1875     }
1876     gclog_or_tty->print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk "
1877                         PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
1878                         this, chunk, chunk->word_size(), list_count);
1879     locked_print_free_chunks(gclog_or_tty);
1880   }
1881 
1882   return chunk;
1883 }
1884 
1885 void ChunkManager::print_on(outputStream* out) const {
1886   if (PrintFLSStatistics != 0) {
1887     const_cast<ChunkManager *>(this)->humongous_dictionary()->report_statistics();
1888   }
1889 }
1890 
1891 // SpaceManager methods
1892 
1893 size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) {
1894   size_t chunk_sizes[] = {
1895       specialized_chunk_size(is_class_space),
1896       small_chunk_size(is_class_space),
1897       medium_chunk_size(is_class_space)
1898   };
1899 
1900   // Adjust up to one of the fixed chunk sizes ...
1901   for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) {
1902     if (requested <= chunk_sizes[i]) {
1903       return chunk_sizes[i];
1904     }
1905   }
1906 
1907   // ... or return the size as a humongous chunk.
1908   return requested;
1909 }
1910 
1911 size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const {
1912   return adjust_initial_chunk_size(requested, is_class());
1913 }
1914 
1915 size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const {
1916   size_t requested;
1917 
1918   if (is_class()) {
1919     switch (type) {
1920     case Metaspace::BootMetaspaceType:       requested = Metaspace::first_class_chunk_word_size(); break;
1921     case Metaspace::ROMetaspaceType:         requested = ClassSpecializedChunk; break;
1922     case Metaspace::ReadWriteMetaspaceType:  requested = ClassSpecializedChunk; break;
1923     case Metaspace::AnonymousMetaspaceType:  requested = ClassSpecializedChunk; break;
1924     case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break;
1925     default:                                 requested = ClassSmallChunk; break;
1926     }
1927   } else {
1928     switch (type) {
1929     case Metaspace::BootMetaspaceType:       requested = Metaspace::first_chunk_word_size(); break;
1930     case Metaspace::ROMetaspaceType:         requested = SharedReadOnlySize / wordSize; break;
1931     case Metaspace::ReadWriteMetaspaceType:  requested = SharedReadWriteSize / wordSize; break;
1932     case Metaspace::AnonymousMetaspaceType:  requested = SpecializedChunk; break;
1933     case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break;
1934     default:                                 requested = SmallChunk; break;
1935     }
1936   }
1937 
1938   // Adjust to one of the fixed chunk sizes (unless humongous)
1939   const size_t adjusted = adjust_initial_chunk_size(requested);
1940 
1941   assert(adjusted != 0, err_msg("Incorrect initial chunk size. Requested: "
1942          SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted));
1943 
1944   return adjusted;
1945 }
1946 
1947 size_t SpaceManager::sum_free_in_chunks_in_use() const {
1948   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1949   size_t free = 0;
1950   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1951     Metachunk* chunk = chunks_in_use(i);
1952     while (chunk != NULL) {
1953       free += chunk->free_word_size();
1954       chunk = chunk->next();
1955     }
1956   }
1957   return free;
1958 }
1959 
1960 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
1961   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1962   size_t result = 0;
1963   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1964    result += sum_waste_in_chunks_in_use(i);
1965   }
1966 
1967   return result;
1968 }
1969 
1970 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
1971   size_t result = 0;
1972   Metachunk* chunk = chunks_in_use(index);
1973   // Count the free space in all the chunk but not the
1974   // current chunk from which allocations are still being done.
1975   while (chunk != NULL) {
1976     if (chunk != current_chunk()) {
1977       result += chunk->free_word_size();
1978     }
1979     chunk = chunk->next();
1980   }
1981   return result;
1982 }
1983 
1984 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
1985   // For CMS use "allocated_chunks_words()" which does not need the
1986   // Metaspace lock.  For the other collectors sum over the
1987   // lists.  Use both methods as a check that "allocated_chunks_words()"
1988   // is correct.  That is, sum_capacity_in_chunks() is too expensive
1989   // to use in the product and allocated_chunks_words() should be used
1990   // but allow for  checking that allocated_chunks_words() returns the same
1991   // value as sum_capacity_in_chunks_in_use() which is the definitive
1992   // answer.
1993   if (UseConcMarkSweepGC) {
1994     return allocated_chunks_words();
1995   } else {
1996     MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1997     size_t sum = 0;
1998     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1999       Metachunk* chunk = chunks_in_use(i);
2000       while (chunk != NULL) {
2001         sum += chunk->word_size();
2002         chunk = chunk->next();
2003       }
2004     }
2005   return sum;
2006   }
2007 }
2008 
2009 size_t SpaceManager::sum_count_in_chunks_in_use() {
2010   size_t count = 0;
2011   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2012     count = count + sum_count_in_chunks_in_use(i);
2013   }
2014 
2015   return count;
2016 }
2017 
2018 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
2019   size_t count = 0;
2020   Metachunk* chunk = chunks_in_use(i);
2021   while (chunk != NULL) {
2022     count++;
2023     chunk = chunk->next();
2024   }
2025   return count;
2026 }
2027 
2028 
2029 size_t SpaceManager::sum_used_in_chunks_in_use() const {
2030   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2031   size_t used = 0;
2032   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2033     Metachunk* chunk = chunks_in_use(i);
2034     while (chunk != NULL) {
2035       used += chunk->used_word_size();
2036       chunk = chunk->next();
2037     }
2038   }
2039   return used;
2040 }
2041 
2042 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
2043 
2044   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2045     Metachunk* chunk = chunks_in_use(i);
2046     st->print("SpaceManager: %s " PTR_FORMAT,
2047                  chunk_size_name(i), chunk);
2048     if (chunk != NULL) {
2049       st->print_cr(" free " SIZE_FORMAT,
2050                    chunk->free_word_size());
2051     } else {
2052       st->cr();
2053     }
2054   }
2055 
2056   chunk_manager()->locked_print_free_chunks(st);
2057   chunk_manager()->locked_print_sum_free_chunks(st);
2058 }
2059 
2060 size_t SpaceManager::calc_chunk_size(size_t word_size) {
2061 
2062   // Decide between a small chunk and a medium chunk.  Up to
2063   // _small_chunk_limit small chunks can be allocated but
2064   // once a medium chunk has been allocated, no more small
2065   // chunks will be allocated.
2066   size_t chunk_word_size;
2067   if (chunks_in_use(MediumIndex) == NULL &&
2068       sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) {
2069     chunk_word_size = (size_t) small_chunk_size();
2070     if (word_size + Metachunk::overhead() > small_chunk_size()) {
2071       chunk_word_size = medium_chunk_size();
2072     }
2073   } else {
2074     chunk_word_size = medium_chunk_size();
2075   }
2076 
2077   // Might still need a humongous chunk.  Enforce
2078   // humongous allocations sizes to be aligned up to
2079   // the smallest chunk size.
2080   size_t if_humongous_sized_chunk =
2081     align_size_up(word_size + Metachunk::overhead(),
2082                   smallest_chunk_size());
2083   chunk_word_size =
2084     MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
2085 
2086   assert(!SpaceManager::is_humongous(word_size) ||
2087          chunk_word_size == if_humongous_sized_chunk,
2088          err_msg("Size calculation is wrong, word_size " SIZE_FORMAT
2089                  " chunk_word_size " SIZE_FORMAT,
2090                  word_size, chunk_word_size));
2091   if (TraceMetadataHumongousAllocation &&
2092       SpaceManager::is_humongous(word_size)) {
2093     gclog_or_tty->print_cr("Metadata humongous allocation:");
2094     gclog_or_tty->print_cr("  word_size " PTR_FORMAT, word_size);
2095     gclog_or_tty->print_cr("  chunk_word_size " PTR_FORMAT,
2096                            chunk_word_size);
2097     gclog_or_tty->print_cr("    chunk overhead " PTR_FORMAT,
2098                            Metachunk::overhead());
2099   }
2100   return chunk_word_size;
2101 }
2102 
2103 void SpaceManager::track_metaspace_memory_usage() {
2104   if (is_init_completed()) {
2105     if (is_class()) {
2106       MemoryService::track_compressed_class_memory_usage();
2107     }
2108     MemoryService::track_metaspace_memory_usage();
2109   }
2110 }
2111 
2112 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
2113   assert(vs_list()->current_virtual_space() != NULL,
2114          "Should have been set");
2115   assert(current_chunk() == NULL ||
2116          current_chunk()->allocate(word_size) == NULL,
2117          "Don't need to expand");
2118   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2119 
2120   if (TraceMetadataChunkAllocation && Verbose) {
2121     size_t words_left = 0;
2122     size_t words_used = 0;
2123     if (current_chunk() != NULL) {
2124       words_left = current_chunk()->free_word_size();
2125       words_used = current_chunk()->used_word_size();
2126     }
2127     gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
2128                            " words " SIZE_FORMAT " words used " SIZE_FORMAT
2129                            " words left",
2130                             word_size, words_used, words_left);
2131   }
2132 
2133   // Get another chunk out of the virtual space
2134   size_t chunk_word_size = calc_chunk_size(word_size);
2135   Metachunk* next = get_new_chunk(chunk_word_size);
2136 
2137   MetaWord* mem = NULL;
2138 
2139   // If a chunk was available, add it to the in-use chunk list
2140   // and do an allocation from it.
2141   if (next != NULL) {
2142     // Add to this manager's list of chunks in use.
2143     add_chunk(next, false);
2144     mem = next->allocate(word_size);
2145   }
2146 
2147   // Track metaspace memory usage statistic.
2148   track_metaspace_memory_usage();
2149 
2150   return mem;
2151 }
2152 
2153 void SpaceManager::print_on(outputStream* st) const {
2154 
2155   for (ChunkIndex i = ZeroIndex;
2156        i < NumberOfInUseLists ;
2157        i = next_chunk_index(i) ) {
2158     st->print_cr("  chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
2159                  chunks_in_use(i),
2160                  chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
2161   }
2162   st->print_cr("    waste:  Small " SIZE_FORMAT " Medium " SIZE_FORMAT
2163                " Humongous " SIZE_FORMAT,
2164                sum_waste_in_chunks_in_use(SmallIndex),
2165                sum_waste_in_chunks_in_use(MediumIndex),
2166                sum_waste_in_chunks_in_use(HumongousIndex));
2167   // block free lists
2168   if (block_freelists() != NULL) {
2169     st->print_cr("total in block free lists " SIZE_FORMAT,
2170       block_freelists()->total_size());
2171   }
2172 }
2173 
2174 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
2175                            Mutex* lock) :
2176   _mdtype(mdtype),
2177   _allocated_blocks_words(0),
2178   _allocated_chunks_words(0),
2179   _allocated_chunks_count(0),
2180   _lock(lock)
2181 {
2182   initialize();
2183 }
2184 
2185 void SpaceManager::inc_size_metrics(size_t words) {
2186   assert_lock_strong(SpaceManager::expand_lock());
2187   // Total of allocated Metachunks and allocated Metachunks count
2188   // for each SpaceManager
2189   _allocated_chunks_words = _allocated_chunks_words + words;
2190   _allocated_chunks_count++;
2191   // Global total of capacity in allocated Metachunks
2192   MetaspaceAux::inc_capacity(mdtype(), words);
2193   // Global total of allocated Metablocks.
2194   // used_words_slow() includes the overhead in each
2195   // Metachunk so include it in the used when the
2196   // Metachunk is first added (so only added once per
2197   // Metachunk).
2198   MetaspaceAux::inc_used(mdtype(), Metachunk::overhead());
2199 }
2200 
2201 void SpaceManager::inc_used_metrics(size_t words) {
2202   // Add to the per SpaceManager total
2203   Atomic::add_ptr(words, &_allocated_blocks_words);
2204   // Add to the global total
2205   MetaspaceAux::inc_used(mdtype(), words);
2206 }
2207 
2208 void SpaceManager::dec_total_from_size_metrics() {
2209   MetaspaceAux::dec_capacity(mdtype(), allocated_chunks_words());
2210   MetaspaceAux::dec_used(mdtype(), allocated_blocks_words());
2211   // Also deduct the overhead per Metachunk
2212   MetaspaceAux::dec_used(mdtype(), allocated_chunks_count() * Metachunk::overhead());
2213 }
2214 
2215 void SpaceManager::initialize() {
2216   Metadebug::init_allocation_fail_alot_count();
2217   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2218     _chunks_in_use[i] = NULL;
2219   }
2220   _current_chunk = NULL;
2221   if (TraceMetadataChunkAllocation && Verbose) {
2222     gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
2223   }
2224 }
2225 
2226 void ChunkManager::return_chunks(ChunkIndex index, Metachunk* chunks) {
2227   if (chunks == NULL) {
2228     return;
2229   }
2230   ChunkList* list = free_chunks(index);
2231   assert(list->size() == chunks->word_size(), "Mismatch in chunk sizes");
2232   assert_lock_strong(SpaceManager::expand_lock());
2233   Metachunk* cur = chunks;
2234 
2235   // This returns chunks one at a time.  If a new
2236   // class List can be created that is a base class
2237   // of FreeList then something like FreeList::prepend()
2238   // can be used in place of this loop
2239   while (cur != NULL) {
2240     assert(cur->container() != NULL, "Container should have been set");
2241     cur->container()->dec_container_count();
2242     // Capture the next link before it is changed
2243     // by the call to return_chunk_at_head();
2244     Metachunk* next = cur->next();
2245     DEBUG_ONLY(cur->set_is_tagged_free(true);)
2246     list->return_chunk_at_head(cur);
2247     cur = next;
2248   }
2249 }
2250 
2251 SpaceManager::~SpaceManager() {
2252   // This call this->_lock which can't be done while holding expand_lock()
2253   assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(),
2254     err_msg("sum_capacity_in_chunks_in_use() " SIZE_FORMAT
2255             " allocated_chunks_words() " SIZE_FORMAT,
2256             sum_capacity_in_chunks_in_use(), allocated_chunks_words()));
2257 
2258   MutexLockerEx fcl(SpaceManager::expand_lock(),
2259                     Mutex::_no_safepoint_check_flag);
2260 
2261   chunk_manager()->slow_locked_verify();
2262 
2263   dec_total_from_size_metrics();
2264 
2265   if (TraceMetadataChunkAllocation && Verbose) {
2266     gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
2267     locked_print_chunks_in_use_on(gclog_or_tty);
2268   }
2269 
2270   // Do not mangle freed Metachunks.  The chunk size inside Metachunks
2271   // is during the freeing of a VirtualSpaceNodes.
2272 
2273   // Have to update before the chunks_in_use lists are emptied
2274   // below.
2275   chunk_manager()->inc_free_chunks_total(allocated_chunks_words(),
2276                                          sum_count_in_chunks_in_use());
2277 
2278   // Add all the chunks in use by this space manager
2279   // to the global list of free chunks.
2280 
2281   // Follow each list of chunks-in-use and add them to the
2282   // free lists.  Each list is NULL terminated.
2283 
2284   for (ChunkIndex i = ZeroIndex; i < HumongousIndex; i = next_chunk_index(i)) {
2285     if (TraceMetadataChunkAllocation && Verbose) {
2286       gclog_or_tty->print_cr("returned %d %s chunks to freelist",
2287                              sum_count_in_chunks_in_use(i),
2288                              chunk_size_name(i));
2289     }
2290     Metachunk* chunks = chunks_in_use(i);
2291     chunk_manager()->return_chunks(i, chunks);
2292     set_chunks_in_use(i, NULL);
2293     if (TraceMetadataChunkAllocation && Verbose) {
2294       gclog_or_tty->print_cr("updated freelist count %d %s",
2295                              chunk_manager()->free_chunks(i)->count(),
2296                              chunk_size_name(i));
2297     }
2298     assert(i != HumongousIndex, "Humongous chunks are handled explicitly later");
2299   }
2300 
2301   // The medium chunk case may be optimized by passing the head and
2302   // tail of the medium chunk list to add_at_head().  The tail is often
2303   // the current chunk but there are probably exceptions.
2304 
2305   // Humongous chunks
2306   if (TraceMetadataChunkAllocation && Verbose) {
2307     gclog_or_tty->print_cr("returned %d %s humongous chunks to dictionary",
2308                             sum_count_in_chunks_in_use(HumongousIndex),
2309                             chunk_size_name(HumongousIndex));
2310     gclog_or_tty->print("Humongous chunk dictionary: ");
2311   }
2312   // Humongous chunks are never the current chunk.
2313   Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
2314 
2315   while (humongous_chunks != NULL) {
2316 #ifdef ASSERT
2317     humongous_chunks->set_is_tagged_free(true);
2318 #endif
2319     if (TraceMetadataChunkAllocation && Verbose) {
2320       gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ",
2321                           humongous_chunks,
2322                           humongous_chunks->word_size());
2323     }
2324     assert(humongous_chunks->word_size() == (size_t)
2325            align_size_up(humongous_chunks->word_size(),
2326                              smallest_chunk_size()),
2327            err_msg("Humongous chunk size is wrong: word size " SIZE_FORMAT
2328                    " granularity %d",
2329                    humongous_chunks->word_size(), smallest_chunk_size()));
2330     Metachunk* next_humongous_chunks = humongous_chunks->next();
2331     humongous_chunks->container()->dec_container_count();
2332     chunk_manager()->humongous_dictionary()->return_chunk(humongous_chunks);
2333     humongous_chunks = next_humongous_chunks;
2334   }
2335   if (TraceMetadataChunkAllocation && Verbose) {
2336     gclog_or_tty->cr();
2337     gclog_or_tty->print_cr("updated dictionary count %d %s",
2338                      chunk_manager()->humongous_dictionary()->total_count(),
2339                      chunk_size_name(HumongousIndex));
2340   }
2341   chunk_manager()->slow_locked_verify();
2342 }
2343 
2344 const char* SpaceManager::chunk_size_name(ChunkIndex index) const {
2345   switch (index) {
2346     case SpecializedIndex:
2347       return "Specialized";
2348     case SmallIndex:
2349       return "Small";
2350     case MediumIndex:
2351       return "Medium";
2352     case HumongousIndex:
2353       return "Humongous";
2354     default:
2355       return NULL;
2356   }
2357 }
2358 
2359 ChunkIndex ChunkManager::list_index(size_t size) {
2360   switch (size) {
2361     case SpecializedChunk:
2362       assert(SpecializedChunk == ClassSpecializedChunk,
2363              "Need branch for ClassSpecializedChunk");
2364       return SpecializedIndex;
2365     case SmallChunk:
2366     case ClassSmallChunk:
2367       return SmallIndex;
2368     case MediumChunk:
2369     case ClassMediumChunk:
2370       return MediumIndex;
2371     default:
2372       assert(size > MediumChunk || size > ClassMediumChunk,
2373              "Not a humongous chunk");
2374       return HumongousIndex;
2375   }
2376 }
2377 
2378 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
2379   assert_lock_strong(_lock);
2380   size_t raw_word_size = get_raw_word_size(word_size);
2381   size_t min_size = TreeChunk<Metablock, FreeList<Metablock> >::min_size();
2382   assert(raw_word_size >= min_size,
2383          err_msg("Should not deallocate dark matter " SIZE_FORMAT "<" SIZE_FORMAT, word_size, min_size));
2384   block_freelists()->return_block(p, raw_word_size);
2385 }
2386 
2387 // Adds a chunk to the list of chunks in use.
2388 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
2389 
2390   assert(new_chunk != NULL, "Should not be NULL");
2391   assert(new_chunk->next() == NULL, "Should not be on a list");
2392 
2393   new_chunk->reset_empty();
2394 
2395   // Find the correct list and and set the current
2396   // chunk for that list.
2397   ChunkIndex index = ChunkManager::list_index(new_chunk->word_size());
2398 
2399   if (index != HumongousIndex) {
2400     retire_current_chunk();
2401     set_current_chunk(new_chunk);
2402     new_chunk->set_next(chunks_in_use(index));
2403     set_chunks_in_use(index, new_chunk);
2404   } else {
2405     // For null class loader data and DumpSharedSpaces, the first chunk isn't
2406     // small, so small will be null.  Link this first chunk as the current
2407     // chunk.
2408     if (make_current) {
2409       // Set as the current chunk but otherwise treat as a humongous chunk.
2410       set_current_chunk(new_chunk);
2411     }
2412     // Link at head.  The _current_chunk only points to a humongous chunk for
2413     // the null class loader metaspace (class and data virtual space managers)
2414     // any humongous chunks so will not point to the tail
2415     // of the humongous chunks list.
2416     new_chunk->set_next(chunks_in_use(HumongousIndex));
2417     set_chunks_in_use(HumongousIndex, new_chunk);
2418 
2419     assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
2420   }
2421 
2422   // Add to the running sum of capacity
2423   inc_size_metrics(new_chunk->word_size());
2424 
2425   assert(new_chunk->is_empty(), "Not ready for reuse");
2426   if (TraceMetadataChunkAllocation && Verbose) {
2427     gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
2428                         sum_count_in_chunks_in_use());
2429     new_chunk->print_on(gclog_or_tty);
2430     chunk_manager()->locked_print_free_chunks(gclog_or_tty);
2431   }
2432 }
2433 
2434 void SpaceManager::retire_current_chunk() {
2435   if (current_chunk() != NULL) {
2436     size_t remaining_words = current_chunk()->free_word_size();
2437     if (remaining_words >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
2438       block_freelists()->return_block(current_chunk()->allocate(remaining_words), remaining_words);
2439       inc_used_metrics(remaining_words);
2440     }
2441   }
2442 }
2443 
2444 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) {
2445   // Get a chunk from the chunk freelist
2446   Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size);
2447 
2448   if (next == NULL) {
2449     next = vs_list()->get_new_chunk(chunk_word_size,
2450                                     medium_chunk_bunch());
2451   }
2452 
2453   if (TraceMetadataHumongousAllocation && next != NULL &&
2454       SpaceManager::is_humongous(next->word_size())) {
2455     gclog_or_tty->print_cr("  new humongous chunk word size "
2456                            PTR_FORMAT, next->word_size());
2457   }
2458 
2459   return next;
2460 }
2461 
2462 MetaWord* SpaceManager::allocate(size_t word_size) {
2463   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2464 
2465   size_t raw_word_size = get_raw_word_size(word_size);
2466   BlockFreelist* fl =  block_freelists();
2467   MetaWord* p = NULL;
2468   // Allocation from the dictionary is expensive in the sense that
2469   // the dictionary has to be searched for a size.  Don't allocate
2470   // from the dictionary until it starts to get fat.  Is this
2471   // a reasonable policy?  Maybe an skinny dictionary is fast enough
2472   // for allocations.  Do some profiling.  JJJ
2473   if (fl->total_size() > allocation_from_dictionary_limit) {
2474     p = fl->get_block(raw_word_size);
2475   }
2476   if (p == NULL) {
2477     p = allocate_work(raw_word_size);
2478   }
2479 
2480   return p;
2481 }
2482 
2483 // Returns the address of spaced allocated for "word_size".
2484 // This methods does not know about blocks (Metablocks)
2485 MetaWord* SpaceManager::allocate_work(size_t word_size) {
2486   assert_lock_strong(_lock);
2487 #ifdef ASSERT
2488   if (Metadebug::test_metadata_failure()) {
2489     return NULL;
2490   }
2491 #endif
2492   // Is there space in the current chunk?
2493   MetaWord* result = NULL;
2494 
2495   // For DumpSharedSpaces, only allocate out of the current chunk which is
2496   // never null because we gave it the size we wanted.   Caller reports out
2497   // of memory if this returns null.
2498   if (DumpSharedSpaces) {
2499     assert(current_chunk() != NULL, "should never happen");
2500     inc_used_metrics(word_size);
2501     return current_chunk()->allocate(word_size); // caller handles null result
2502   }
2503 
2504   if (current_chunk() != NULL) {
2505     result = current_chunk()->allocate(word_size);
2506   }
2507 
2508   if (result == NULL) {
2509     result = grow_and_allocate(word_size);
2510   }
2511 
2512   if (result != NULL) {
2513     inc_used_metrics(word_size);
2514     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
2515            "Head of the list is being allocated");
2516   }
2517 
2518   return result;
2519 }
2520 
2521 void SpaceManager::verify() {
2522   // If there are blocks in the dictionary, then
2523   // verfication of chunks does not work since
2524   // being in the dictionary alters a chunk.
2525   if (block_freelists()->total_size() == 0) {
2526     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2527       Metachunk* curr = chunks_in_use(i);
2528       while (curr != NULL) {
2529         curr->verify();
2530         verify_chunk_size(curr);
2531         curr = curr->next();
2532       }
2533     }
2534   }
2535 }
2536 
2537 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
2538   assert(is_humongous(chunk->word_size()) ||
2539          chunk->word_size() == medium_chunk_size() ||
2540          chunk->word_size() == small_chunk_size() ||
2541          chunk->word_size() == specialized_chunk_size(),
2542          "Chunk size is wrong");
2543   return;
2544 }
2545 
2546 #ifdef ASSERT
2547 void SpaceManager::verify_allocated_blocks_words() {
2548   // Verification is only guaranteed at a safepoint.
2549   assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(),
2550     "Verification can fail if the applications is running");
2551   assert(allocated_blocks_words() == sum_used_in_chunks_in_use(),
2552     err_msg("allocation total is not consistent " SIZE_FORMAT
2553             " vs " SIZE_FORMAT,
2554             allocated_blocks_words(), sum_used_in_chunks_in_use()));
2555 }
2556 
2557 #endif
2558 
2559 void SpaceManager::dump(outputStream* const out) const {
2560   size_t curr_total = 0;
2561   size_t waste = 0;
2562   uint i = 0;
2563   size_t used = 0;
2564   size_t capacity = 0;
2565 
2566   // Add up statistics for all chunks in this SpaceManager.
2567   for (ChunkIndex index = ZeroIndex;
2568        index < NumberOfInUseLists;
2569        index = next_chunk_index(index)) {
2570     for (Metachunk* curr = chunks_in_use(index);
2571          curr != NULL;
2572          curr = curr->next()) {
2573       out->print("%d) ", i++);
2574       curr->print_on(out);
2575       curr_total += curr->word_size();
2576       used += curr->used_word_size();
2577       capacity += curr->word_size();
2578       waste += curr->free_word_size() + curr->overhead();;
2579     }
2580   }
2581 
2582   if (TraceMetadataChunkAllocation && Verbose) {
2583     block_freelists()->print_on(out);
2584   }
2585 
2586   size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size();
2587   // Free space isn't wasted.
2588   waste -= free;
2589 
2590   out->print_cr("total of all chunks "  SIZE_FORMAT " used " SIZE_FORMAT
2591                 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
2592                 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
2593 }
2594 
2595 #ifndef PRODUCT
2596 void SpaceManager::mangle_freed_chunks() {
2597   for (ChunkIndex index = ZeroIndex;
2598        index < NumberOfInUseLists;
2599        index = next_chunk_index(index)) {
2600     for (Metachunk* curr = chunks_in_use(index);
2601          curr != NULL;
2602          curr = curr->next()) {
2603       curr->mangle();
2604     }
2605   }
2606 }
2607 #endif // PRODUCT
2608 
2609 // MetaspaceAux
2610 
2611 
2612 size_t MetaspaceAux::_capacity_words[] = {0, 0};
2613 size_t MetaspaceAux::_used_words[] = {0, 0};
2614 
2615 size_t MetaspaceAux::free_bytes(Metaspace::MetadataType mdtype) {
2616   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2617   return list == NULL ? 0 : list->free_bytes();
2618 }
2619 
2620 size_t MetaspaceAux::free_bytes() {
2621   return free_bytes(Metaspace::ClassType) + free_bytes(Metaspace::NonClassType);
2622 }
2623 
2624 void MetaspaceAux::dec_capacity(Metaspace::MetadataType mdtype, size_t words) {
2625   assert_lock_strong(SpaceManager::expand_lock());
2626   assert(words <= capacity_words(mdtype),
2627     err_msg("About to decrement below 0: words " SIZE_FORMAT
2628             " is greater than _capacity_words[%u] " SIZE_FORMAT,
2629             words, mdtype, capacity_words(mdtype)));
2630   _capacity_words[mdtype] -= words;
2631 }
2632 
2633 void MetaspaceAux::inc_capacity(Metaspace::MetadataType mdtype, size_t words) {
2634   assert_lock_strong(SpaceManager::expand_lock());
2635   // Needs to be atomic
2636   _capacity_words[mdtype] += words;
2637 }
2638 
2639 void MetaspaceAux::dec_used(Metaspace::MetadataType mdtype, size_t words) {
2640   assert(words <= used_words(mdtype),
2641     err_msg("About to decrement below 0: words " SIZE_FORMAT
2642             " is greater than _used_words[%u] " SIZE_FORMAT,
2643             words, mdtype, used_words(mdtype)));
2644   // For CMS deallocation of the Metaspaces occurs during the
2645   // sweep which is a concurrent phase.  Protection by the expand_lock()
2646   // is not enough since allocation is on a per Metaspace basis
2647   // and protected by the Metaspace lock.
2648   jlong minus_words = (jlong) - (jlong) words;
2649   Atomic::add_ptr(minus_words, &_used_words[mdtype]);
2650 }
2651 
2652 void MetaspaceAux::inc_used(Metaspace::MetadataType mdtype, size_t words) {
2653   // _used_words tracks allocations for
2654   // each piece of metadata.  Those allocations are
2655   // generally done concurrently by different application
2656   // threads so must be done atomically.
2657   Atomic::add_ptr(words, &_used_words[mdtype]);
2658 }
2659 
2660 size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) {
2661   size_t used = 0;
2662   ClassLoaderDataGraphMetaspaceIterator iter;
2663   while (iter.repeat()) {
2664     Metaspace* msp = iter.get_next();
2665     // Sum allocated_blocks_words for each metaspace
2666     if (msp != NULL) {
2667       used += msp->used_words_slow(mdtype);
2668     }
2669   }
2670   return used * BytesPerWord;
2671 }
2672 
2673 size_t MetaspaceAux::free_bytes_slow(Metaspace::MetadataType mdtype) {
2674   size_t free = 0;
2675   ClassLoaderDataGraphMetaspaceIterator iter;
2676   while (iter.repeat()) {
2677     Metaspace* msp = iter.get_next();
2678     if (msp != NULL) {
2679       free += msp->free_words_slow(mdtype);
2680     }
2681   }
2682   return free * BytesPerWord;
2683 }
2684 
2685 size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) {
2686   if ((mdtype == Metaspace::ClassType) && !Metaspace::using_class_space()) {
2687     return 0;
2688   }
2689   // Don't count the space in the freelists.  That space will be
2690   // added to the capacity calculation as needed.
2691   size_t capacity = 0;
2692   ClassLoaderDataGraphMetaspaceIterator iter;
2693   while (iter.repeat()) {
2694     Metaspace* msp = iter.get_next();
2695     if (msp != NULL) {
2696       capacity += msp->capacity_words_slow(mdtype);
2697     }
2698   }
2699   return capacity * BytesPerWord;
2700 }
2701 
2702 size_t MetaspaceAux::capacity_bytes_slow() {
2703 #ifdef PRODUCT
2704   // Use capacity_bytes() in PRODUCT instead of this function.
2705   guarantee(false, "Should not call capacity_bytes_slow() in the PRODUCT");
2706 #endif
2707   size_t class_capacity = capacity_bytes_slow(Metaspace::ClassType);
2708   size_t non_class_capacity = capacity_bytes_slow(Metaspace::NonClassType);
2709   assert(capacity_bytes() == class_capacity + non_class_capacity,
2710       err_msg("bad accounting: capacity_bytes() " SIZE_FORMAT
2711         " class_capacity + non_class_capacity " SIZE_FORMAT
2712         " class_capacity " SIZE_FORMAT " non_class_capacity " SIZE_FORMAT,
2713         capacity_bytes(), class_capacity + non_class_capacity,
2714         class_capacity, non_class_capacity));
2715 
2716   return class_capacity + non_class_capacity;
2717 }
2718 
2719 size_t MetaspaceAux::reserved_bytes(Metaspace::MetadataType mdtype) {
2720   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2721   return list == NULL ? 0 : list->reserved_bytes();
2722 }
2723 
2724 size_t MetaspaceAux::committed_bytes(Metaspace::MetadataType mdtype) {
2725   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2726   return list == NULL ? 0 : list->committed_bytes();
2727 }
2728 
2729 size_t MetaspaceAux::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); }
2730 
2731 size_t MetaspaceAux::free_chunks_total_words(Metaspace::MetadataType mdtype) {
2732   ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype);
2733   if (chunk_manager == NULL) {
2734     return 0;
2735   }
2736   chunk_manager->slow_verify();
2737   return chunk_manager->free_chunks_total_words();
2738 }
2739 
2740 size_t MetaspaceAux::free_chunks_total_bytes(Metaspace::MetadataType mdtype) {
2741   return free_chunks_total_words(mdtype) * BytesPerWord;
2742 }
2743 
2744 size_t MetaspaceAux::free_chunks_total_words() {
2745   return free_chunks_total_words(Metaspace::ClassType) +
2746          free_chunks_total_words(Metaspace::NonClassType);
2747 }
2748 
2749 size_t MetaspaceAux::free_chunks_total_bytes() {
2750   return free_chunks_total_words() * BytesPerWord;
2751 }
2752 
2753 bool MetaspaceAux::has_chunk_free_list(Metaspace::MetadataType mdtype) {
2754   return Metaspace::get_chunk_manager(mdtype) != NULL;
2755 }
2756 
2757 MetaspaceChunkFreeListSummary MetaspaceAux::chunk_free_list_summary(Metaspace::MetadataType mdtype) {
2758   if (!has_chunk_free_list(mdtype)) {
2759     return MetaspaceChunkFreeListSummary();
2760   }
2761 
2762   const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype);
2763   return cm->chunk_free_list_summary();
2764 }
2765 
2766 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
2767   gclog_or_tty->print(", [Metaspace:");
2768   if (PrintGCDetails && Verbose) {
2769     gclog_or_tty->print(" "  SIZE_FORMAT
2770                         "->" SIZE_FORMAT
2771                         "("  SIZE_FORMAT ")",
2772                         prev_metadata_used,
2773                         used_bytes(),
2774                         reserved_bytes());
2775   } else {
2776     gclog_or_tty->print(" "  SIZE_FORMAT "K"
2777                         "->" SIZE_FORMAT "K"
2778                         "("  SIZE_FORMAT "K)",
2779                         prev_metadata_used/K,
2780                         used_bytes()/K,
2781                         reserved_bytes()/K);
2782   }
2783 
2784   gclog_or_tty->print("]");
2785 }
2786 
2787 // This is printed when PrintGCDetails
2788 void MetaspaceAux::print_on(outputStream* out) {
2789   Metaspace::MetadataType nct = Metaspace::NonClassType;
2790 
2791   out->print_cr(" Metaspace       "
2792                 "used "      SIZE_FORMAT "K, "
2793                 "capacity "  SIZE_FORMAT "K, "
2794                 "committed " SIZE_FORMAT "K, "
2795                 "reserved "  SIZE_FORMAT "K",
2796                 used_bytes()/K,
2797                 capacity_bytes()/K,
2798                 committed_bytes()/K,
2799                 reserved_bytes()/K);
2800 
2801   if (Metaspace::using_class_space()) {
2802     Metaspace::MetadataType ct = Metaspace::ClassType;
2803     out->print_cr("  class space    "
2804                   "used "      SIZE_FORMAT "K, "
2805                   "capacity "  SIZE_FORMAT "K, "
2806                   "committed " SIZE_FORMAT "K, "
2807                   "reserved "  SIZE_FORMAT "K",
2808                   used_bytes(ct)/K,
2809                   capacity_bytes(ct)/K,
2810                   committed_bytes(ct)/K,
2811                   reserved_bytes(ct)/K);
2812   }
2813 }
2814 
2815 // Print information for class space and data space separately.
2816 // This is almost the same as above.
2817 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
2818   size_t free_chunks_capacity_bytes = free_chunks_total_bytes(mdtype);
2819   size_t capacity_bytes = capacity_bytes_slow(mdtype);
2820   size_t used_bytes = used_bytes_slow(mdtype);
2821   size_t free_bytes = free_bytes_slow(mdtype);
2822   size_t used_and_free = used_bytes + free_bytes +
2823                            free_chunks_capacity_bytes;
2824   out->print_cr("  Chunk accounting: used in chunks " SIZE_FORMAT
2825              "K + unused in chunks " SIZE_FORMAT "K  + "
2826              " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
2827              "K  capacity in allocated chunks " SIZE_FORMAT "K",
2828              used_bytes / K,
2829              free_bytes / K,
2830              free_chunks_capacity_bytes / K,
2831              used_and_free / K,
2832              capacity_bytes / K);
2833   // Accounting can only be correct if we got the values during a safepoint
2834   assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong");
2835 }
2836 
2837 // Print total fragmentation for class metaspaces
2838 void MetaspaceAux::print_class_waste(outputStream* out) {
2839   assert(Metaspace::using_class_space(), "class metaspace not used");
2840   size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0;
2841   size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_humongous_count = 0;
2842   ClassLoaderDataGraphMetaspaceIterator iter;
2843   while (iter.repeat()) {
2844     Metaspace* msp = iter.get_next();
2845     if (msp != NULL) {
2846       cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2847       cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2848       cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2849       cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
2850       cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2851       cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
2852       cls_humongous_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2853     }
2854   }
2855   out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2856                 SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2857                 SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2858                 "large count " SIZE_FORMAT,
2859                 cls_specialized_count, cls_specialized_waste,
2860                 cls_small_count, cls_small_waste,
2861                 cls_medium_count, cls_medium_waste, cls_humongous_count);
2862 }
2863 
2864 // Print total fragmentation for data and class metaspaces separately
2865 void MetaspaceAux::print_waste(outputStream* out) {
2866   size_t specialized_waste = 0, small_waste = 0, medium_waste = 0;
2867   size_t specialized_count = 0, small_count = 0, medium_count = 0, humongous_count = 0;
2868 
2869   ClassLoaderDataGraphMetaspaceIterator iter;
2870   while (iter.repeat()) {
2871     Metaspace* msp = iter.get_next();
2872     if (msp != NULL) {
2873       specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2874       specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2875       small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2876       small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
2877       medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2878       medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
2879       humongous_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2880     }
2881   }
2882   out->print_cr("Total fragmentation waste (words) doesn't count free space");
2883   out->print_cr("  data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2884                         SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2885                         SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2886                         "large count " SIZE_FORMAT,
2887              specialized_count, specialized_waste, small_count,
2888              small_waste, medium_count, medium_waste, humongous_count);
2889   if (Metaspace::using_class_space()) {
2890     print_class_waste(out);
2891   }
2892 }
2893 
2894 // Dump global metaspace things from the end of ClassLoaderDataGraph
2895 void MetaspaceAux::dump(outputStream* out) {
2896   out->print_cr("All Metaspace:");
2897   out->print("data space: "); print_on(out, Metaspace::NonClassType);
2898   out->print("class space: "); print_on(out, Metaspace::ClassType);
2899   print_waste(out);
2900 }
2901 
2902 void MetaspaceAux::verify_free_chunks() {
2903   Metaspace::chunk_manager_metadata()->verify();
2904   if (Metaspace::using_class_space()) {
2905     Metaspace::chunk_manager_class()->verify();
2906   }
2907 }
2908 
2909 void MetaspaceAux::verify_capacity() {
2910 #ifdef ASSERT
2911   size_t running_sum_capacity_bytes = capacity_bytes();
2912   // For purposes of the running sum of capacity, verify against capacity
2913   size_t capacity_in_use_bytes = capacity_bytes_slow();
2914   assert(running_sum_capacity_bytes == capacity_in_use_bytes,
2915     err_msg("capacity_words() * BytesPerWord " SIZE_FORMAT
2916             " capacity_bytes_slow()" SIZE_FORMAT,
2917             running_sum_capacity_bytes, capacity_in_use_bytes));
2918   for (Metaspace::MetadataType i = Metaspace::ClassType;
2919        i < Metaspace:: MetadataTypeCount;
2920        i = (Metaspace::MetadataType)(i + 1)) {
2921     size_t capacity_in_use_bytes = capacity_bytes_slow(i);
2922     assert(capacity_bytes(i) == capacity_in_use_bytes,
2923       err_msg("capacity_bytes(%u) " SIZE_FORMAT
2924               " capacity_bytes_slow(%u)" SIZE_FORMAT,
2925               i, capacity_bytes(i), i, capacity_in_use_bytes));
2926   }
2927 #endif
2928 }
2929 
2930 void MetaspaceAux::verify_used() {
2931 #ifdef ASSERT
2932   size_t running_sum_used_bytes = used_bytes();
2933   // For purposes of the running sum of used, verify against used
2934   size_t used_in_use_bytes = used_bytes_slow();
2935   assert(used_bytes() == used_in_use_bytes,
2936     err_msg("used_bytes() " SIZE_FORMAT
2937             " used_bytes_slow()" SIZE_FORMAT,
2938             used_bytes(), used_in_use_bytes));
2939   for (Metaspace::MetadataType i = Metaspace::ClassType;
2940        i < Metaspace:: MetadataTypeCount;
2941        i = (Metaspace::MetadataType)(i + 1)) {
2942     size_t used_in_use_bytes = used_bytes_slow(i);
2943     assert(used_bytes(i) == used_in_use_bytes,
2944       err_msg("used_bytes(%u) " SIZE_FORMAT
2945               " used_bytes_slow(%u)" SIZE_FORMAT,
2946               i, used_bytes(i), i, used_in_use_bytes));
2947   }
2948 #endif
2949 }
2950 
2951 void MetaspaceAux::verify_metrics() {
2952   verify_capacity();
2953   verify_used();
2954 }
2955 
2956 
2957 // Metaspace methods
2958 
2959 size_t Metaspace::_first_chunk_word_size = 0;
2960 size_t Metaspace::_first_class_chunk_word_size = 0;
2961 
2962 size_t Metaspace::_commit_alignment = 0;
2963 size_t Metaspace::_reserve_alignment = 0;
2964 
2965 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
2966   initialize(lock, type);
2967 }
2968 
2969 Metaspace::~Metaspace() {
2970   delete _vsm;
2971   if (using_class_space()) {
2972     delete _class_vsm;
2973   }
2974 }
2975 
2976 VirtualSpaceList* Metaspace::_space_list = NULL;
2977 VirtualSpaceList* Metaspace::_class_space_list = NULL;
2978 
2979 ChunkManager* Metaspace::_chunk_manager_metadata = NULL;
2980 ChunkManager* Metaspace::_chunk_manager_class = NULL;
2981 
2982 #define VIRTUALSPACEMULTIPLIER 2
2983 
2984 #ifdef _LP64
2985 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
2986 
2987 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) {
2988   // Figure out the narrow_klass_base and the narrow_klass_shift.  The
2989   // narrow_klass_base is the lower of the metaspace base and the cds base
2990   // (if cds is enabled).  The narrow_klass_shift depends on the distance
2991   // between the lower base and higher address.
2992   address lower_base;
2993   address higher_address;
2994 #if INCLUDE_CDS
2995   if (UseSharedSpaces) {
2996     higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
2997                           (address)(metaspace_base + compressed_class_space_size()));
2998     lower_base = MIN2(metaspace_base, cds_base);
2999   } else
3000 #endif
3001   {
3002     higher_address = metaspace_base + compressed_class_space_size();
3003     lower_base = metaspace_base;
3004 
3005     uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes;
3006     // If compressed class space fits in lower 32G, we don't need a base.
3007     if (higher_address <= (address)klass_encoding_max) {
3008       lower_base = 0; // effectively lower base is zero.
3009     }
3010   }
3011 
3012   Universe::set_narrow_klass_base(lower_base);
3013 
3014   if ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) {
3015     Universe::set_narrow_klass_shift(0);
3016   } else {
3017     assert(!UseSharedSpaces, "Cannot shift with UseSharedSpaces");
3018     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
3019   }
3020 }
3021 
3022 #if INCLUDE_CDS
3023 // Return TRUE if the specified metaspace_base and cds_base are close enough
3024 // to work with compressed klass pointers.
3025 bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) {
3026   assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS");
3027   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3028   address lower_base = MIN2((address)metaspace_base, cds_base);
3029   address higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
3030                                 (address)(metaspace_base + compressed_class_space_size()));
3031   return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
3032 }
3033 #endif
3034 
3035 // Try to allocate the metaspace at the requested addr.
3036 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
3037   assert(using_class_space(), "called improperly");
3038   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3039   assert(compressed_class_space_size() < KlassEncodingMetaspaceMax,
3040          "Metaspace size is too big");
3041   assert_is_ptr_aligned(requested_addr, _reserve_alignment);
3042   assert_is_ptr_aligned(cds_base, _reserve_alignment);
3043   assert_is_size_aligned(compressed_class_space_size(), _reserve_alignment);
3044 
3045   // Don't use large pages for the class space.
3046   bool large_pages = false;
3047 
3048   ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(),
3049                                              _reserve_alignment,
3050                                              large_pages,
3051                                              requested_addr, 0);
3052   if (!metaspace_rs.is_reserved()) {
3053 #if INCLUDE_CDS
3054     if (UseSharedSpaces) {
3055       size_t increment = align_size_up(1*G, _reserve_alignment);
3056 
3057       // Keep trying to allocate the metaspace, increasing the requested_addr
3058       // by 1GB each time, until we reach an address that will no longer allow
3059       // use of CDS with compressed klass pointers.
3060       char *addr = requested_addr;
3061       while (!metaspace_rs.is_reserved() && (addr + increment > addr) &&
3062              can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
3063         addr = addr + increment;
3064         metaspace_rs = ReservedSpace(compressed_class_space_size(),
3065                                      _reserve_alignment, large_pages, addr, 0);
3066       }
3067     }
3068 #endif
3069     // If no successful allocation then try to allocate the space anywhere.  If
3070     // that fails then OOM doom.  At this point we cannot try allocating the
3071     // metaspace as if UseCompressedClassPointers is off because too much
3072     // initialization has happened that depends on UseCompressedClassPointers.
3073     // So, UseCompressedClassPointers cannot be turned off at this point.
3074     if (!metaspace_rs.is_reserved()) {
3075       metaspace_rs = ReservedSpace(compressed_class_space_size(),
3076                                    _reserve_alignment, large_pages);
3077       if (!metaspace_rs.is_reserved()) {
3078         vm_exit_during_initialization(err_msg("Could not allocate metaspace: %d bytes",
3079                                               compressed_class_space_size()));
3080       }
3081     }
3082   }
3083 
3084   // If we got here then the metaspace got allocated.
3085   MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass);
3086 
3087 #if INCLUDE_CDS
3088   // Verify that we can use shared spaces.  Otherwise, turn off CDS.
3089   if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) {
3090     FileMapInfo::stop_sharing_and_unmap(
3091         "Could not allocate metaspace at a compatible address");
3092   }
3093 #endif
3094   set_narrow_klass_base_and_shift((address)metaspace_rs.base(),
3095                                   UseSharedSpaces ? (address)cds_base : 0);
3096 
3097   initialize_class_space(metaspace_rs);
3098 
3099   if (PrintCompressedOopsMode || (PrintMiscellaneous && Verbose)) {
3100     gclog_or_tty->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: " SIZE_FORMAT,
3101                             Universe::narrow_klass_base(), Universe::narrow_klass_shift());
3102     gclog_or_tty->print_cr("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT " Req Addr: " PTR_FORMAT,
3103                            compressed_class_space_size(), metaspace_rs.base(), requested_addr);
3104   }
3105 }
3106 
3107 // For UseCompressedClassPointers the class space is reserved above the top of
3108 // the Java heap.  The argument passed in is at the base of the compressed space.
3109 void Metaspace::initialize_class_space(ReservedSpace rs) {
3110   // The reserved space size may be bigger because of alignment, esp with UseLargePages
3111   assert(rs.size() >= CompressedClassSpaceSize,
3112          err_msg(SIZE_FORMAT " != " UINTX_FORMAT, rs.size(), CompressedClassSpaceSize));
3113   assert(using_class_space(), "Must be using class space");
3114   _class_space_list = new VirtualSpaceList(rs);
3115   _chunk_manager_class = new ChunkManager(ClassSpecializedChunk, ClassSmallChunk, ClassMediumChunk);
3116 
3117   if (!_class_space_list->initialization_succeeded()) {
3118     vm_exit_during_initialization("Failed to setup compressed class space virtual space list.");
3119   }
3120 }
3121 
3122 #endif
3123 
3124 void Metaspace::ergo_initialize() {
3125   if (DumpSharedSpaces) {
3126     // Using large pages when dumping the shared archive is currently not implemented.
3127     FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false);
3128   }
3129 
3130   size_t page_size = os::vm_page_size();
3131   if (UseLargePages && UseLargePagesInMetaspace) {
3132     page_size = os::large_page_size();
3133   }
3134 
3135   _commit_alignment  = page_size;
3136   _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
3137 
3138   // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
3139   // override if MaxMetaspaceSize was set on the command line or not.
3140   // This information is needed later to conform to the specification of the
3141   // java.lang.management.MemoryUsage API.
3142   //
3143   // Ideally, we would be able to set the default value of MaxMetaspaceSize in
3144   // globals.hpp to the aligned value, but this is not possible, since the
3145   // alignment depends on other flags being parsed.
3146   MaxMetaspaceSize = align_size_down_bounded(MaxMetaspaceSize, _reserve_alignment);
3147 
3148   if (MetaspaceSize > MaxMetaspaceSize) {
3149     MetaspaceSize = MaxMetaspaceSize;
3150   }
3151 
3152   MetaspaceSize = align_size_down_bounded(MetaspaceSize, _commit_alignment);
3153 
3154   assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
3155 
3156   if (MetaspaceSize < 256*K) {
3157     vm_exit_during_initialization("Too small initial Metaspace size");
3158   }
3159 
3160   MinMetaspaceExpansion = align_size_down_bounded(MinMetaspaceExpansion, _commit_alignment);
3161   MaxMetaspaceExpansion = align_size_down_bounded(MaxMetaspaceExpansion, _commit_alignment);
3162 
3163   CompressedClassSpaceSize = align_size_down_bounded(CompressedClassSpaceSize, _reserve_alignment);
3164   set_compressed_class_space_size(CompressedClassSpaceSize);
3165 
3166   // Initial virtual space size will be calculated at global_initialize()
3167   uintx min_metaspace_sz =
3168       VIRTUALSPACEMULTIPLIER * InitialBootClassLoaderMetaspaceSize;
3169   if (UseCompressedClassPointers) {
3170     if ((min_metaspace_sz + CompressedClassSpaceSize) >  MaxMetaspaceSize) {
3171       if (min_metaspace_sz >= MaxMetaspaceSize) {
3172         vm_exit_during_initialization("MaxMetaspaceSize is too small.");
3173       } else {
3174         FLAG_SET_ERGO(uintx, CompressedClassSpaceSize,
3175                       MaxMetaspaceSize - min_metaspace_sz);
3176       }
3177     }
3178   } else if (min_metaspace_sz >= MaxMetaspaceSize) {
3179     FLAG_SET_ERGO(uintx, InitialBootClassLoaderMetaspaceSize,
3180                   min_metaspace_sz);
3181   }
3182 
3183 }
3184 
3185 void Metaspace::global_initialize() {
3186   MetaspaceGC::initialize();
3187 
3188   // Initialize the alignment for shared spaces.
3189   int max_alignment = os::vm_allocation_granularity();
3190   size_t cds_total = 0;
3191 
3192   MetaspaceShared::set_max_alignment(max_alignment);
3193 
3194   if (DumpSharedSpaces) {
3195 #if INCLUDE_CDS
3196     MetaspaceShared::estimate_regions_size();
3197 
3198     SharedReadOnlySize  = align_size_up(SharedReadOnlySize,  max_alignment);
3199     SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
3200     SharedMiscDataSize  = align_size_up(SharedMiscDataSize,  max_alignment);
3201     SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize,  max_alignment);
3202 
3203     // the min_misc_code_size estimate is based on MetaspaceShared::generate_vtable_methods()
3204     uintx min_misc_code_size = align_size_up(
3205       (MetaspaceShared::num_virtuals * MetaspaceShared::vtbl_list_size) *
3206         (sizeof(void*) + MetaspaceShared::vtbl_method_size) + MetaspaceShared::vtbl_common_code_size,
3207           max_alignment);
3208 
3209     if (SharedMiscCodeSize < min_misc_code_size) {
3210       report_out_of_shared_space(SharedMiscCode);
3211     }
3212 
3213     // Initialize with the sum of the shared space sizes.  The read-only
3214     // and read write metaspace chunks will be allocated out of this and the
3215     // remainder is the misc code and data chunks.
3216     cds_total = FileMapInfo::shared_spaces_size();
3217     cds_total = align_size_up(cds_total, _reserve_alignment);
3218     _space_list = new VirtualSpaceList(cds_total/wordSize);
3219     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3220 
3221     if (!_space_list->initialization_succeeded()) {
3222       vm_exit_during_initialization("Unable to dump shared archive.", NULL);
3223     }
3224 
3225 #ifdef _LP64
3226     if (cds_total + compressed_class_space_size() > UnscaledClassSpaceMax) {
3227       vm_exit_during_initialization("Unable to dump shared archive.",
3228           err_msg("Size of archive (" SIZE_FORMAT ") + compressed class space ("
3229                   SIZE_FORMAT ") == total (" SIZE_FORMAT ") is larger than compressed "
3230                   "klass limit: " SIZE_FORMAT, cds_total, compressed_class_space_size(),
3231                   cds_total + compressed_class_space_size(), UnscaledClassSpaceMax));
3232     }
3233 
3234     // Set the compressed klass pointer base so that decoding of these pointers works
3235     // properly when creating the shared archive.
3236     assert(UseCompressedOops && UseCompressedClassPointers,
3237       "UseCompressedOops and UseCompressedClassPointers must be set");
3238     Universe::set_narrow_klass_base((address)_space_list->current_virtual_space()->bottom());
3239     if (TraceMetavirtualspaceAllocation && Verbose) {
3240       gclog_or_tty->print_cr("Setting_narrow_klass_base to Address: " PTR_FORMAT,
3241                              _space_list->current_virtual_space()->bottom());
3242     }
3243 
3244     Universe::set_narrow_klass_shift(0);
3245 #endif // _LP64
3246 #endif // INCLUDE_CDS
3247   } else {
3248 #if INCLUDE_CDS
3249     // If using shared space, open the file that contains the shared space
3250     // and map in the memory before initializing the rest of metaspace (so
3251     // the addresses don't conflict)
3252     address cds_address = NULL;
3253     if (UseSharedSpaces) {
3254       FileMapInfo* mapinfo = new FileMapInfo();
3255 
3256       // Open the shared archive file, read and validate the header. If
3257       // initialization fails, shared spaces [UseSharedSpaces] are
3258       // disabled and the file is closed.
3259       // Map in spaces now also
3260       if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
3261         cds_total = FileMapInfo::shared_spaces_size();
3262         cds_address = (address)mapinfo->region_base(0);
3263       } else {
3264         assert(!mapinfo->is_open() && !UseSharedSpaces,
3265                "archive file not closed or shared spaces not disabled.");
3266       }
3267     }
3268 #endif // INCLUDE_CDS
3269 #ifdef _LP64
3270     // If UseCompressedClassPointers is set then allocate the metaspace area
3271     // above the heap and above the CDS area (if it exists).
3272     if (using_class_space()) {
3273       if (UseSharedSpaces) {
3274 #if INCLUDE_CDS
3275         char* cds_end = (char*)(cds_address + cds_total);
3276         cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
3277         allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
3278 #endif
3279       } else {
3280         char* base = (char*)align_ptr_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
3281         allocate_metaspace_compressed_klass_ptrs(base, 0);
3282       }
3283     }
3284 #endif // _LP64
3285 
3286     // Initialize these before initializing the VirtualSpaceList
3287     _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
3288     _first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
3289     // Make the first class chunk bigger than a medium chunk so it's not put
3290     // on the medium chunk list.   The next chunk will be small and progress
3291     // from there.  This size calculated by -version.
3292     _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
3293                                        (CompressedClassSpaceSize/BytesPerWord)*2);
3294     _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
3295     // Arbitrarily set the initial virtual space to a multiple
3296     // of the boot class loader size.
3297     size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size;
3298     word_size = align_size_up(word_size, Metaspace::reserve_alignment_words());
3299 
3300     // Initialize the list of virtual spaces.
3301     _space_list = new VirtualSpaceList(word_size);
3302     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3303 
3304     if (!_space_list->initialization_succeeded()) {
3305       vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL);
3306     }
3307   }
3308 
3309   _tracer = new MetaspaceTracer();
3310 }
3311 
3312 void Metaspace::post_initialize() {
3313   MetaspaceGC::post_initialize();
3314 }
3315 
3316 void Metaspace::initialize_first_chunk(MetaspaceType type, MetadataType mdtype) {
3317   Metachunk* chunk = get_initialization_chunk(type, mdtype);
3318   if (chunk != NULL) {
3319     // Add to this manager's list of chunks in use and current_chunk().
3320     get_space_manager(mdtype)->add_chunk(chunk, true);
3321   }
3322 }
3323 
3324 Metachunk* Metaspace::get_initialization_chunk(MetaspaceType type, MetadataType mdtype) {
3325   size_t chunk_word_size = get_space_manager(mdtype)->get_initial_chunk_size(type);
3326 
3327   // Get a chunk from the chunk freelist
3328   Metachunk* chunk = get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size);
3329 
3330   if (chunk == NULL) {
3331     chunk = get_space_list(mdtype)->get_new_chunk(chunk_word_size,
3332                                                   get_space_manager(mdtype)->medium_chunk_bunch());
3333   }
3334 
3335   // For dumping shared archive, report error if allocation has failed.
3336   if (DumpSharedSpaces && chunk == NULL) {
3337     report_insufficient_metaspace(MetaspaceAux::committed_bytes() + chunk_word_size * BytesPerWord);
3338   }
3339 
3340   return chunk;
3341 }
3342 
3343 void Metaspace::verify_global_initialization() {
3344   assert(space_list() != NULL, "Metadata VirtualSpaceList has not been initialized");
3345   assert(chunk_manager_metadata() != NULL, "Metadata ChunkManager has not been initialized");
3346 
3347   if (using_class_space()) {
3348     assert(class_space_list() != NULL, "Class VirtualSpaceList has not been initialized");
3349     assert(chunk_manager_class() != NULL, "Class ChunkManager has not been initialized");
3350   }
3351 }
3352 
3353 void Metaspace::initialize(Mutex* lock, MetaspaceType type) {
3354   verify_global_initialization();
3355 
3356   // Allocate SpaceManager for metadata objects.
3357   _vsm = new SpaceManager(NonClassType, lock);
3358 
3359   if (using_class_space()) {
3360     // Allocate SpaceManager for classes.
3361     _class_vsm = new SpaceManager(ClassType, lock);
3362   }
3363 
3364   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3365 
3366   // Allocate chunk for metadata objects
3367   initialize_first_chunk(type, NonClassType);
3368 
3369   // Allocate chunk for class metadata objects
3370   if (using_class_space()) {
3371     initialize_first_chunk(type, ClassType);
3372   }
3373 
3374   _alloc_record_head = NULL;
3375   _alloc_record_tail = NULL;
3376 }
3377 
3378 size_t Metaspace::align_word_size_up(size_t word_size) {
3379   size_t byte_size = word_size * wordSize;
3380   return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
3381 }
3382 
3383 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
3384   // DumpSharedSpaces doesn't use class metadata area (yet)
3385   // Also, don't use class_vsm() unless UseCompressedClassPointers is true.
3386   if (is_class_space_allocation(mdtype)) {
3387     return  class_vsm()->allocate(word_size);
3388   } else {
3389     return  vsm()->allocate(word_size);
3390   }
3391 }
3392 
3393 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
3394   size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
3395   assert(delta_bytes > 0, "Must be");
3396 
3397   size_t before = 0;
3398   size_t after = 0;
3399   MetaWord* res;
3400   bool incremented;
3401 
3402   // Each thread increments the HWM at most once. Even if the thread fails to increment
3403   // the HWM, an allocation is still attempted. This is because another thread must then
3404   // have incremented the HWM and therefore the allocation might still succeed.
3405   do {
3406     incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before);
3407     res = allocate(word_size, mdtype);
3408   } while (!incremented && res == NULL);
3409 
3410   if (incremented) {
3411     tracer()->report_gc_threshold(before, after,
3412                                   MetaspaceGCThresholdUpdater::ExpandAndAllocate);
3413     if (PrintGCDetails && Verbose) {
3414       gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
3415           " to " SIZE_FORMAT, before, after);
3416     }
3417   }
3418 
3419   return res;
3420 }
3421 
3422 // Space allocated in the Metaspace.  This may
3423 // be across several metadata virtual spaces.
3424 char* Metaspace::bottom() const {
3425   assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
3426   return (char*)vsm()->current_chunk()->bottom();
3427 }
3428 
3429 size_t Metaspace::used_words_slow(MetadataType mdtype) const {
3430   if (mdtype == ClassType) {
3431     return using_class_space() ? class_vsm()->sum_used_in_chunks_in_use() : 0;
3432   } else {
3433     return vsm()->sum_used_in_chunks_in_use();  // includes overhead!
3434   }
3435 }
3436 
3437 size_t Metaspace::free_words_slow(MetadataType mdtype) const {
3438   if (mdtype == ClassType) {
3439     return using_class_space() ? class_vsm()->sum_free_in_chunks_in_use() : 0;
3440   } else {
3441     return vsm()->sum_free_in_chunks_in_use();
3442   }
3443 }
3444 
3445 // Space capacity in the Metaspace.  It includes
3446 // space in the list of chunks from which allocations
3447 // have been made. Don't include space in the global freelist and
3448 // in the space available in the dictionary which
3449 // is already counted in some chunk.
3450 size_t Metaspace::capacity_words_slow(MetadataType mdtype) const {
3451   if (mdtype == ClassType) {
3452     return using_class_space() ? class_vsm()->sum_capacity_in_chunks_in_use() : 0;
3453   } else {
3454     return vsm()->sum_capacity_in_chunks_in_use();
3455   }
3456 }
3457 
3458 size_t Metaspace::used_bytes_slow(MetadataType mdtype) const {
3459   return used_words_slow(mdtype) * BytesPerWord;
3460 }
3461 
3462 size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const {
3463   return capacity_words_slow(mdtype) * BytesPerWord;
3464 }
3465 
3466 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
3467   if (SafepointSynchronize::is_at_safepoint()) {
3468     if (DumpSharedSpaces && PrintSharedSpaces) {
3469       record_deallocation(ptr, vsm()->get_raw_word_size(word_size));
3470     }
3471 
3472     assert(Thread::current()->is_VM_thread(), "should be the VM thread");
3473     // Don't take Heap_lock
3474     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
3475     if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
3476       // Dark matter.  Too small for dictionary.
3477 #ifdef ASSERT
3478       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
3479 #endif
3480       return;
3481     }
3482     if (is_class && using_class_space()) {
3483       class_vsm()->deallocate(ptr, word_size);
3484     } else {
3485       vsm()->deallocate(ptr, word_size);
3486     }
3487   } else {
3488     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
3489 
3490     if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
3491       // Dark matter.  Too small for dictionary.
3492 #ifdef ASSERT
3493       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
3494 #endif
3495       return;
3496     }
3497     if (is_class && using_class_space()) {
3498       class_vsm()->deallocate(ptr, word_size);
3499     } else {
3500       vsm()->deallocate(ptr, word_size);
3501     }
3502   }
3503 }
3504 
3505 
3506 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
3507                               bool read_only, MetaspaceObj::Type type, TRAPS) {
3508   if (HAS_PENDING_EXCEPTION) {
3509     assert(false, "Should not allocate with exception pending");
3510     return NULL;  // caller does a CHECK_NULL too
3511   }
3512 
3513   assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
3514         "ClassLoaderData::the_null_class_loader_data() should have been used.");
3515 
3516   // Allocate in metaspaces without taking out a lock, because it deadlocks
3517   // with the SymbolTable_lock.  Dumping is single threaded for now.  We'll have
3518   // to revisit this for application class data sharing.
3519   if (DumpSharedSpaces) {
3520     assert(type > MetaspaceObj::UnknownType && type < MetaspaceObj::_number_of_types, "sanity");
3521     Metaspace* space = read_only ? loader_data->ro_metaspace() : loader_data->rw_metaspace();
3522     MetaWord* result = space->allocate(word_size, NonClassType);
3523     if (result == NULL) {
3524       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
3525     }
3526     if (PrintSharedSpaces) {
3527       space->record_allocation(result, type, space->vsm()->get_raw_word_size(word_size));
3528     }
3529 
3530     // Zero initialize.
3531     Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3532 
3533     return result;
3534   }
3535 
3536   MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
3537 
3538   // Try to allocate metadata.
3539   MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
3540 
3541   if (result == NULL) {
3542     tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
3543 
3544     // Allocation failed.
3545     if (is_init_completed()) {
3546       // Only start a GC if the bootstrapping has completed.
3547 
3548       // Try to clean out some memory and retry.
3549       result = Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
3550           loader_data, word_size, mdtype);
3551     }
3552   }
3553 
3554   if (result == NULL) {
3555     report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL);
3556   }
3557 
3558   // Zero initialize.
3559   Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3560 
3561   return result;
3562 }
3563 
3564 size_t Metaspace::class_chunk_size(size_t word_size) {
3565   assert(using_class_space(), "Has to use class space");
3566   return class_vsm()->calc_chunk_size(word_size);
3567 }
3568 
3569 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
3570   tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
3571 
3572   // If result is still null, we are out of memory.
3573   if (Verbose && TraceMetadataChunkAllocation) {
3574     gclog_or_tty->print_cr("Metaspace allocation failed for size "
3575         SIZE_FORMAT, word_size);
3576     if (loader_data->metaspace_or_null() != NULL) {
3577       loader_data->dump(gclog_or_tty);
3578     }
3579     MetaspaceAux::dump(gclog_or_tty);
3580   }
3581 
3582   bool out_of_compressed_class_space = false;
3583   if (is_class_space_allocation(mdtype)) {
3584     Metaspace* metaspace = loader_data->metaspace_non_null();
3585     out_of_compressed_class_space =
3586       MetaspaceAux::committed_bytes(Metaspace::ClassType) +
3587       (metaspace->class_chunk_size(word_size) * BytesPerWord) >
3588       CompressedClassSpaceSize;
3589   }
3590 
3591   // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
3592   const char* space_string = out_of_compressed_class_space ?
3593     "Compressed class space" : "Metaspace";
3594 
3595   report_java_out_of_memory(space_string);
3596 
3597   if (JvmtiExport::should_post_resource_exhausted()) {
3598     JvmtiExport::post_resource_exhausted(
3599         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
3600         space_string);
3601   }
3602 
3603   if (!is_init_completed()) {
3604     vm_exit_during_initialization("OutOfMemoryError", space_string);
3605   }
3606 
3607   if (out_of_compressed_class_space) {
3608     THROW_OOP(Universe::out_of_memory_error_class_metaspace());
3609   } else {
3610     THROW_OOP(Universe::out_of_memory_error_metaspace());
3611   }
3612 }
3613 
3614 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) {
3615   switch (mdtype) {
3616     case Metaspace::ClassType: return "Class";
3617     case Metaspace::NonClassType: return "Metadata";
3618     default:
3619       assert(false, err_msg("Got bad mdtype: %d", (int) mdtype));
3620       return NULL;
3621   }
3622 }
3623 
3624 void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
3625   assert(DumpSharedSpaces, "sanity");
3626 
3627   int byte_size = (int)word_size * HeapWordSize;
3628   AllocRecord *rec = new AllocRecord((address)ptr, type, byte_size);
3629 
3630   if (_alloc_record_head == NULL) {
3631     _alloc_record_head = _alloc_record_tail = rec;
3632   } else if (_alloc_record_tail->_ptr + _alloc_record_tail->_byte_size == (address)ptr) {
3633     _alloc_record_tail->_next = rec;
3634     _alloc_record_tail = rec;
3635   } else {
3636     // slow linear search, but this doesn't happen that often, and only when dumping
3637     for (AllocRecord *old = _alloc_record_head; old; old = old->_next) {
3638       if (old->_ptr == ptr) {
3639         assert(old->_type == MetaspaceObj::DeallocatedType, "sanity");
3640         int remain_bytes = old->_byte_size - byte_size;
3641         assert(remain_bytes >= 0, "sanity");
3642         old->_type = type;
3643 
3644         if (remain_bytes == 0) {
3645           delete(rec);
3646         } else {
3647           address remain_ptr = address(ptr) + byte_size;
3648           rec->_ptr = remain_ptr;
3649           rec->_byte_size = remain_bytes;
3650           rec->_type = MetaspaceObj::DeallocatedType;
3651           rec->_next = old->_next;
3652           old->_byte_size = byte_size;
3653           old->_next = rec;
3654         }
3655         return;
3656       }
3657     }
3658     assert(0, "reallocating a freed pointer that was not recorded");
3659   }
3660 }
3661 
3662 void Metaspace::record_deallocation(void* ptr, size_t word_size) {
3663   assert(DumpSharedSpaces, "sanity");
3664 
3665   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3666     if (rec->_ptr == ptr) {
3667       assert(rec->_byte_size == (int)word_size * HeapWordSize, "sanity");
3668       rec->_type = MetaspaceObj::DeallocatedType;
3669       return;
3670     }
3671   }
3672 
3673   assert(0, "deallocating a pointer that was not recorded");
3674 }
3675 
3676 void Metaspace::iterate(Metaspace::AllocRecordClosure *closure) {
3677   assert(DumpSharedSpaces, "unimplemented for !DumpSharedSpaces");
3678 
3679   address last_addr = (address)bottom();
3680 
3681   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3682     address ptr = rec->_ptr;
3683     if (last_addr < ptr) {
3684       closure->doit(last_addr, MetaspaceObj::UnknownType, ptr - last_addr);
3685     }
3686     closure->doit(ptr, rec->_type, rec->_byte_size);
3687     last_addr = ptr + rec->_byte_size;
3688   }
3689 
3690   address top = ((address)bottom()) + used_bytes_slow(Metaspace::NonClassType);
3691   if (last_addr < top) {
3692     closure->doit(last_addr, MetaspaceObj::UnknownType, top - last_addr);
3693   }
3694 }
3695 
3696 void Metaspace::purge(MetadataType mdtype) {
3697   get_space_list(mdtype)->purge(get_chunk_manager(mdtype));
3698 }
3699 
3700 void Metaspace::purge() {
3701   MutexLockerEx cl(SpaceManager::expand_lock(),
3702                    Mutex::_no_safepoint_check_flag);
3703   purge(NonClassType);
3704   if (using_class_space()) {
3705     purge(ClassType);
3706   }
3707 }
3708 
3709 void Metaspace::print_on(outputStream* out) const {
3710   // Print both class virtual space counts and metaspace.
3711   if (Verbose) {
3712     vsm()->print_on(out);
3713     if (using_class_space()) {
3714       class_vsm()->print_on(out);
3715     }
3716   }
3717 }
3718 
3719 bool Metaspace::contains(const void* ptr) {
3720   if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(ptr)) {
3721     return true;
3722   }
3723 
3724   if (using_class_space() && get_space_list(ClassType)->contains(ptr)) {
3725      return true;
3726   }
3727 
3728   return get_space_list(NonClassType)->contains(ptr);
3729 }
3730 
3731 void Metaspace::verify() {
3732   vsm()->verify();
3733   if (using_class_space()) {
3734     class_vsm()->verify();
3735   }
3736 }
3737 
3738 void Metaspace::dump(outputStream* const out) const {
3739   out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
3740   vsm()->dump(out);
3741   if (using_class_space()) {
3742     out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
3743     class_vsm()->dump(out);
3744   }
3745 }
3746 
3747 /////////////// Unit tests ///////////////
3748 
3749 #ifndef PRODUCT
3750 
3751 class TestMetaspaceAuxTest : AllStatic {
3752  public:
3753   static void test_reserved() {
3754     size_t reserved = MetaspaceAux::reserved_bytes();
3755 
3756     assert(reserved > 0, "assert");
3757 
3758     size_t committed  = MetaspaceAux::committed_bytes();
3759     assert(committed <= reserved, "assert");
3760 
3761     size_t reserved_metadata = MetaspaceAux::reserved_bytes(Metaspace::NonClassType);
3762     assert(reserved_metadata > 0, "assert");
3763     assert(reserved_metadata <= reserved, "assert");
3764 
3765     if (UseCompressedClassPointers) {
3766       size_t reserved_class    = MetaspaceAux::reserved_bytes(Metaspace::ClassType);
3767       assert(reserved_class > 0, "assert");
3768       assert(reserved_class < reserved, "assert");
3769     }
3770   }
3771 
3772   static void test_committed() {
3773     size_t committed = MetaspaceAux::committed_bytes();
3774 
3775     assert(committed > 0, "assert");
3776 
3777     size_t reserved  = MetaspaceAux::reserved_bytes();
3778     assert(committed <= reserved, "assert");
3779 
3780     size_t committed_metadata = MetaspaceAux::committed_bytes(Metaspace::NonClassType);
3781     assert(committed_metadata > 0, "assert");
3782     assert(committed_metadata <= committed, "assert");
3783 
3784     if (UseCompressedClassPointers) {
3785       size_t committed_class    = MetaspaceAux::committed_bytes(Metaspace::ClassType);
3786       assert(committed_class > 0, "assert");
3787       assert(committed_class < committed, "assert");
3788     }
3789   }
3790 
3791   static void test_virtual_space_list_large_chunk() {
3792     VirtualSpaceList* vs_list = new VirtualSpaceList(os::vm_allocation_granularity());
3793     MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3794     // A size larger than VirtualSpaceSize (256k) and add one page to make it _not_ be
3795     // vm_allocation_granularity aligned on Windows.
3796     size_t large_size = (size_t)(2*256*K + (os::vm_page_size()/BytesPerWord));
3797     large_size += (os::vm_page_size()/BytesPerWord);
3798     vs_list->get_new_chunk(large_size, 0);
3799   }
3800 
3801   static void test() {
3802     test_reserved();
3803     test_committed();
3804     test_virtual_space_list_large_chunk();
3805   }
3806 };
3807 
3808 void TestMetaspaceAux_test() {
3809   TestMetaspaceAuxTest::test();
3810 }
3811 
3812 class TestVirtualSpaceNodeTest {
3813   static void chunk_up(size_t words_left, size_t& num_medium_chunks,
3814                                           size_t& num_small_chunks,
3815                                           size_t& num_specialized_chunks) {
3816     num_medium_chunks = words_left / MediumChunk;
3817     words_left = words_left % MediumChunk;
3818 
3819     num_small_chunks = words_left / SmallChunk;
3820     words_left = words_left % SmallChunk;
3821     // how many specialized chunks can we get?
3822     num_specialized_chunks = words_left / SpecializedChunk;
3823     assert(words_left % SpecializedChunk == 0, "should be nothing left");
3824   }
3825 
3826  public:
3827   static void test() {
3828     MutexLockerEx ml(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3829     const size_t vsn_test_size_words = MediumChunk  * 4;
3830     const size_t vsn_test_size_bytes = vsn_test_size_words * BytesPerWord;
3831 
3832     // The chunk sizes must be multiples of eachother, or this will fail
3833     STATIC_ASSERT(MediumChunk % SmallChunk == 0);
3834     STATIC_ASSERT(SmallChunk % SpecializedChunk == 0);
3835 
3836     { // No committed memory in VSN
3837       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3838       VirtualSpaceNode vsn(vsn_test_size_bytes);
3839       vsn.initialize();
3840       vsn.retire(&cm);
3841       assert(cm.sum_free_chunks_count() == 0, "did not commit any memory in the VSN");
3842     }
3843 
3844     { // All of VSN is committed, half is used by chunks
3845       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3846       VirtualSpaceNode vsn(vsn_test_size_bytes);
3847       vsn.initialize();
3848       vsn.expand_by(vsn_test_size_words, vsn_test_size_words);
3849       vsn.get_chunk_vs(MediumChunk);
3850       vsn.get_chunk_vs(MediumChunk);
3851       vsn.retire(&cm);
3852       assert(cm.sum_free_chunks_count() == 2, "should have been memory left for 2 medium chunks");
3853       assert(cm.sum_free_chunks() == 2*MediumChunk, "sizes should add up");
3854     }
3855 
3856     { // 4 pages of VSN is committed, some is used by chunks
3857       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3858       VirtualSpaceNode vsn(vsn_test_size_bytes);
3859       const size_t page_chunks = 4 * (size_t)os::vm_page_size() / BytesPerWord;
3860       assert(page_chunks < MediumChunk, "Test expects medium chunks to be at least 4*page_size");
3861       vsn.initialize();
3862       vsn.expand_by(page_chunks, page_chunks);
3863       vsn.get_chunk_vs(SmallChunk);
3864       vsn.get_chunk_vs(SpecializedChunk);
3865       vsn.retire(&cm);
3866 
3867       // committed - used = words left to retire
3868       const size_t words_left = page_chunks - SmallChunk - SpecializedChunk;
3869 
3870       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3871       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3872 
3873       assert(num_medium_chunks == 0, "should not get any medium chunks");
3874       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3875       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3876     }
3877 
3878     { // Half of VSN is committed, a humongous chunk is used
3879       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3880       VirtualSpaceNode vsn(vsn_test_size_bytes);
3881       vsn.initialize();
3882       vsn.expand_by(MediumChunk * 2, MediumChunk * 2);
3883       vsn.get_chunk_vs(MediumChunk + SpecializedChunk); // Humongous chunks will be aligned up to MediumChunk + SpecializedChunk
3884       vsn.retire(&cm);
3885 
3886       const size_t words_left = MediumChunk * 2 - (MediumChunk + SpecializedChunk);
3887       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3888       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3889 
3890       assert(num_medium_chunks == 0, "should not get any medium chunks");
3891       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3892       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3893     }
3894 
3895   }
3896 
3897 #define assert_is_available_positive(word_size) \
3898   assert(vsn.is_available(word_size), \
3899     err_msg(#word_size ": " PTR_FORMAT " bytes were not available in " \
3900             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3901             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3902 
3903 #define assert_is_available_negative(word_size) \
3904   assert(!vsn.is_available(word_size), \
3905     err_msg(#word_size ": " PTR_FORMAT " bytes should not be available in " \
3906             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3907             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3908 
3909   static void test_is_available_positive() {
3910     // Reserve some memory.
3911     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3912     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3913 
3914     // Commit some memory.
3915     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3916     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3917     assert(expanded, "Failed to commit");
3918 
3919     // Check that is_available accepts the committed size.
3920     assert_is_available_positive(commit_word_size);
3921 
3922     // Check that is_available accepts half the committed size.
3923     size_t expand_word_size = commit_word_size / 2;
3924     assert_is_available_positive(expand_word_size);
3925   }
3926 
3927   static void test_is_available_negative() {
3928     // Reserve some memory.
3929     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3930     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3931 
3932     // Commit some memory.
3933     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3934     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3935     assert(expanded, "Failed to commit");
3936 
3937     // Check that is_available doesn't accept a too large size.
3938     size_t two_times_commit_word_size = commit_word_size * 2;
3939     assert_is_available_negative(two_times_commit_word_size);
3940   }
3941 
3942   static void test_is_available_overflow() {
3943     // Reserve some memory.
3944     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3945     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3946 
3947     // Commit some memory.
3948     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3949     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3950     assert(expanded, "Failed to commit");
3951 
3952     // Calculate a size that will overflow the virtual space size.
3953     void* virtual_space_max = (void*)(uintptr_t)-1;
3954     size_t bottom_to_max = pointer_delta(virtual_space_max, vsn.bottom(), 1);
3955     size_t overflow_size = bottom_to_max + BytesPerWord;
3956     size_t overflow_word_size = overflow_size / BytesPerWord;
3957 
3958     // Check that is_available can handle the overflow.
3959     assert_is_available_negative(overflow_word_size);
3960   }
3961 
3962   static void test_is_available() {
3963     TestVirtualSpaceNodeTest::test_is_available_positive();
3964     TestVirtualSpaceNodeTest::test_is_available_negative();
3965     TestVirtualSpaceNodeTest::test_is_available_overflow();
3966   }
3967 };
3968 
3969 void TestVirtualSpaceNode_test() {
3970   TestVirtualSpaceNodeTest::test();
3971   TestVirtualSpaceNodeTest::test_is_available();
3972 }
3973 
3974 // The following test is placed here instead of a gtest / unittest file
3975 // because the ChunkManager class is only available in this file.
3976 class SpaceManagerTest : AllStatic {
3977   friend void SpaceManager_test_adjust_initial_chunk_size();
3978 
3979   static void test_adjust_initial_chunk_size(bool is_class) {
3980     const size_t smallest = SpaceManager::smallest_chunk_size(is_class);
3981     const size_t normal   = SpaceManager::small_chunk_size(is_class);
3982     const size_t medium   = SpaceManager::medium_chunk_size(is_class);
3983 
3984 #define test_adjust_initial_chunk_size(value, expected, is_class_value)          \
3985     do {                                                                         \
3986       size_t v = value;                                                          \
3987       size_t e = expected;                                                       \
3988       assert(SpaceManager::adjust_initial_chunk_size(v, (is_class_value)) == e,  \
3989              err_msg("Expected: " SIZE_FORMAT " got: " SIZE_FORMAT, e, v));      \
3990     } while (0)
3991 
3992     // Smallest (specialized)
3993     test_adjust_initial_chunk_size(1,            smallest, is_class);
3994     test_adjust_initial_chunk_size(smallest - 1, smallest, is_class);
3995     test_adjust_initial_chunk_size(smallest,     smallest, is_class);
3996 
3997     // Small
3998     test_adjust_initial_chunk_size(smallest + 1, normal, is_class);
3999     test_adjust_initial_chunk_size(normal - 1,   normal, is_class);
4000     test_adjust_initial_chunk_size(normal,       normal, is_class);
4001 
4002     // Medium
4003     test_adjust_initial_chunk_size(normal + 1, medium, is_class);
4004     test_adjust_initial_chunk_size(medium - 1, medium, is_class);
4005     test_adjust_initial_chunk_size(medium,     medium, is_class);
4006 
4007     // Humongous
4008     test_adjust_initial_chunk_size(medium + 1, medium + 1, is_class);
4009 
4010 #undef test_adjust_initial_chunk_size
4011   }
4012 
4013   static void test_adjust_initial_chunk_size() {
4014     test_adjust_initial_chunk_size(false);
4015     test_adjust_initial_chunk_size(true);
4016   }
4017 };
4018 
4019 void SpaceManager_test_adjust_initial_chunk_size() {
4020   SpaceManagerTest::test_adjust_initial_chunk_size();
4021 }
4022 
4023 #endif