1 /*
   2  * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 #include "precompiled.hpp"
  25 #include "gc_interface/collectedHeap.hpp"
  26 #include "memory/allocation.hpp"
  27 #include "memory/binaryTreeDictionary.hpp"
  28 #include "memory/freeList.hpp"
  29 #include "memory/collectorPolicy.hpp"
  30 #include "memory/filemap.hpp"
  31 #include "memory/freeList.hpp"
  32 #include "memory/gcLocker.hpp"
  33 #include "memory/metachunk.hpp"
  34 #include "memory/metaspace.hpp"
  35 #include "memory/metaspaceGCThresholdUpdater.hpp"
  36 #include "memory/metaspaceShared.hpp"
  37 #include "memory/metaspaceTracer.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "memory/universe.hpp"
  40 #include "runtime/atomic.inline.hpp"
  41 #include "runtime/globals.hpp"
  42 #include "runtime/init.hpp"
  43 #include "runtime/java.hpp"
  44 #include "runtime/mutex.hpp"
  45 #include "runtime/orderAccess.inline.hpp"
  46 #include "services/memTracker.hpp"
  47 #include "services/memoryService.hpp"
  48 #include "utilities/copy.hpp"
  49 #include "utilities/debug.hpp"
  50 
  51 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  52 
  53 typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary;
  54 typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;
  55 
  56 // Set this constant to enable slow integrity checking of the free chunk lists
  57 const bool metaspace_slow_verify = false;
  58 
  59 size_t const allocation_from_dictionary_limit = 4 * K;
  60 
  61 MetaWord* last_allocated = 0;
  62 
  63 size_t Metaspace::_compressed_class_space_size;
  64 const MetaspaceTracer* Metaspace::_tracer = NULL;
  65 
  66 // Used in declarations in SpaceManager and ChunkManager
  67 enum ChunkIndex {
  68   ZeroIndex = 0,
  69   SpecializedIndex = ZeroIndex,
  70   SmallIndex = SpecializedIndex + 1,
  71   MediumIndex = SmallIndex + 1,
  72   HumongousIndex = MediumIndex + 1,
  73   NumberOfFreeLists = 3,
  74   NumberOfInUseLists = 4
  75 };
  76 
  77 enum ChunkSizes {    // in words.
  78   ClassSpecializedChunk = 128,
  79   SpecializedChunk = 128,
  80   ClassSmallChunk = 256,
  81   SmallChunk = 512,
  82   ClassMediumChunk = 4 * K,
  83   MediumChunk = 8 * K
  84 };
  85 
  86 static ChunkIndex next_chunk_index(ChunkIndex i) {
  87   assert(i < NumberOfInUseLists, "Out of bound");
  88   return (ChunkIndex) (i+1);
  89 }
  90 
  91 volatile intptr_t MetaspaceGC::_capacity_until_GC = 0;
  92 uint MetaspaceGC::_shrink_factor = 0;
  93 bool MetaspaceGC::_should_concurrent_collect = false;
  94 
  95 typedef class FreeList<Metachunk> ChunkList;
  96 
  97 // Manages the global free lists of chunks.
  98 class ChunkManager : public CHeapObj<mtInternal> {
  99   friend class TestVirtualSpaceNodeTest;
 100 
 101   // Free list of chunks of different sizes.
 102   //   SpecializedChunk
 103   //   SmallChunk
 104   //   MediumChunk
 105   //   HumongousChunk
 106   ChunkList _free_chunks[NumberOfFreeLists];
 107 
 108   //   HumongousChunk
 109   ChunkTreeDictionary _humongous_dictionary;
 110 
 111   // ChunkManager in all lists of this type
 112   size_t _free_chunks_total;
 113   size_t _free_chunks_count;
 114 
 115   void dec_free_chunks_total(size_t v) {
 116     assert(_free_chunks_count > 0 &&
 117              _free_chunks_total > 0,
 118              "About to go negative");
 119     Atomic::add_ptr(-1, &_free_chunks_count);
 120     jlong minus_v = (jlong) - (jlong) v;
 121     Atomic::add_ptr(minus_v, &_free_chunks_total);
 122   }
 123 
 124   // Debug support
 125 
 126   size_t sum_free_chunks();
 127   size_t sum_free_chunks_count();
 128 
 129   void locked_verify_free_chunks_total();
 130   void slow_locked_verify_free_chunks_total() {
 131     if (metaspace_slow_verify) {
 132       locked_verify_free_chunks_total();
 133     }
 134   }
 135   void locked_verify_free_chunks_count();
 136   void slow_locked_verify_free_chunks_count() {
 137     if (metaspace_slow_verify) {
 138       locked_verify_free_chunks_count();
 139     }
 140   }
 141   void verify_free_chunks_count();
 142 
 143  public:
 144 
 145   ChunkManager(size_t specialized_size, size_t small_size, size_t medium_size)
 146       : _free_chunks_total(0), _free_chunks_count(0) {
 147     _free_chunks[SpecializedIndex].set_size(specialized_size);
 148     _free_chunks[SmallIndex].set_size(small_size);
 149     _free_chunks[MediumIndex].set_size(medium_size);
 150   }
 151 
 152   // add or delete (return) a chunk to the global freelist.
 153   Metachunk* chunk_freelist_allocate(size_t word_size);
 154 
 155   // Map a size to a list index assuming that there are lists
 156   // for special, small, medium, and humongous chunks.
 157   static ChunkIndex list_index(size_t size);
 158 
 159   // Remove the chunk from its freelist.  It is
 160   // expected to be on one of the _free_chunks[] lists.
 161   void remove_chunk(Metachunk* chunk);
 162 
 163   // Add the simple linked list of chunks to the freelist of chunks
 164   // of type index.
 165   void return_chunks(ChunkIndex index, Metachunk* chunks);
 166 
 167   // Total of the space in the free chunks list
 168   size_t free_chunks_total_words();
 169   size_t free_chunks_total_bytes();
 170 
 171   // Number of chunks in the free chunks list
 172   size_t free_chunks_count();
 173 
 174   void inc_free_chunks_total(size_t v, size_t count = 1) {
 175     Atomic::add_ptr(count, &_free_chunks_count);
 176     Atomic::add_ptr(v, &_free_chunks_total);
 177   }
 178   ChunkTreeDictionary* humongous_dictionary() {
 179     return &_humongous_dictionary;
 180   }
 181 
 182   ChunkList* free_chunks(ChunkIndex index);
 183 
 184   // Returns the list for the given chunk word size.
 185   ChunkList* find_free_chunks_list(size_t word_size);
 186 
 187   // Remove from a list by size.  Selects list based on size of chunk.
 188   Metachunk* free_chunks_get(size_t chunk_word_size);
 189 
 190 #define index_bounds_check(index)                                         \
 191   assert(index == SpecializedIndex ||                                     \
 192          index == SmallIndex ||                                           \
 193          index == MediumIndex ||                                          \
 194          index == HumongousIndex, err_msg("Bad index: %d", (int) index))
 195 
 196   size_t num_free_chunks(ChunkIndex index) const {
 197     index_bounds_check(index);
 198 
 199     if (index == HumongousIndex) {
 200       return _humongous_dictionary.total_free_blocks();
 201     }
 202 
 203     ssize_t count = _free_chunks[index].count();
 204     return count == -1 ? 0 : (size_t) count;
 205   }
 206 
 207   size_t size_free_chunks_in_bytes(ChunkIndex index) const {
 208     index_bounds_check(index);
 209 
 210     size_t word_size = 0;
 211     if (index == HumongousIndex) {
 212       word_size = _humongous_dictionary.total_size();
 213     } else {
 214       const size_t size_per_chunk_in_words = _free_chunks[index].size();
 215       word_size = size_per_chunk_in_words * num_free_chunks(index);
 216     }
 217 
 218     return word_size * BytesPerWord;
 219   }
 220 
 221   MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
 222     return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
 223                                          num_free_chunks(SmallIndex),
 224                                          num_free_chunks(MediumIndex),
 225                                          num_free_chunks(HumongousIndex),
 226                                          size_free_chunks_in_bytes(SpecializedIndex),
 227                                          size_free_chunks_in_bytes(SmallIndex),
 228                                          size_free_chunks_in_bytes(MediumIndex),
 229                                          size_free_chunks_in_bytes(HumongousIndex));
 230   }
 231 
 232   // Debug support
 233   void verify();
 234   void slow_verify() {
 235     if (metaspace_slow_verify) {
 236       verify();
 237     }
 238   }
 239   void locked_verify();
 240   void slow_locked_verify() {
 241     if (metaspace_slow_verify) {
 242       locked_verify();
 243     }
 244   }
 245   void verify_free_chunks_total();
 246 
 247   void locked_print_free_chunks(outputStream* st);
 248   void locked_print_sum_free_chunks(outputStream* st);
 249 
 250   void print_on(outputStream* st) const;
 251 };
 252 
 253 // Used to manage the free list of Metablocks (a block corresponds
 254 // to the allocation of a quantum of metadata).
 255 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
 256   BlockTreeDictionary* _dictionary;
 257 
 258   // Only allocate and split from freelist if the size of the allocation
 259   // is at least 1/4th the size of the available block.
 260   const static int WasteMultiplier = 4;
 261 
 262   // Accessors
 263   BlockTreeDictionary* dictionary() const { return _dictionary; }
 264 
 265  public:
 266   BlockFreelist();
 267   ~BlockFreelist();
 268 
 269   // Get and return a block to the free list
 270   MetaWord* get_block(size_t word_size);
 271   void return_block(MetaWord* p, size_t word_size);
 272 
 273   size_t total_size() {
 274   if (dictionary() == NULL) {
 275     return 0;
 276   } else {
 277     return dictionary()->total_size();
 278   }
 279 }
 280 
 281   void print_on(outputStream* st) const;
 282 };
 283 
 284 // A VirtualSpaceList node.
 285 class VirtualSpaceNode : public CHeapObj<mtClass> {
 286   friend class VirtualSpaceList;
 287 
 288   // Link to next VirtualSpaceNode
 289   VirtualSpaceNode* _next;
 290 
 291   // total in the VirtualSpace
 292   MemRegion _reserved;
 293   ReservedSpace _rs;
 294   VirtualSpace _virtual_space;
 295   MetaWord* _top;
 296   // count of chunks contained in this VirtualSpace
 297   uintx _container_count;
 298 
 299   // Convenience functions to access the _virtual_space
 300   char* low()  const { return virtual_space()->low(); }
 301   char* high() const { return virtual_space()->high(); }
 302 
 303   // The first Metachunk will be allocated at the bottom of the
 304   // VirtualSpace
 305   Metachunk* first_chunk() { return (Metachunk*) bottom(); }
 306 
 307   // Committed but unused space in the virtual space
 308   size_t free_words_in_vs() const;
 309  public:
 310 
 311   VirtualSpaceNode(size_t byte_size);
 312   VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs), _container_count(0) {}
 313   ~VirtualSpaceNode();
 314 
 315   // Convenience functions for logical bottom and end
 316   MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
 317   MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
 318 
 319   bool contains(const void* ptr) { return ptr >= low() && ptr < high(); }
 320 
 321   size_t reserved_words() const  { return _virtual_space.reserved_size() / BytesPerWord; }
 322   size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; }
 323 
 324   bool is_pre_committed() const { return _virtual_space.special(); }
 325 
 326   // address of next available space in _virtual_space;
 327   // Accessors
 328   VirtualSpaceNode* next() { return _next; }
 329   void set_next(VirtualSpaceNode* v) { _next = v; }
 330 
 331   void set_reserved(MemRegion const v) { _reserved = v; }
 332   void set_top(MetaWord* v) { _top = v; }
 333 
 334   // Accessors
 335   MemRegion* reserved() { return &_reserved; }
 336   VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
 337 
 338   // Returns true if "word_size" is available in the VirtualSpace
 339   bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); }
 340 
 341   MetaWord* top() const { return _top; }
 342   void inc_top(size_t word_size) { _top += word_size; }
 343 
 344   uintx container_count() { return _container_count; }
 345   void inc_container_count();
 346   void dec_container_count();
 347 #ifdef ASSERT
 348   uint container_count_slow();
 349   void verify_container_count();
 350 #endif
 351 
 352   // used and capacity in this single entry in the list
 353   size_t used_words_in_vs() const;
 354   size_t capacity_words_in_vs() const;
 355 
 356   bool initialize();
 357 
 358   // get space from the virtual space
 359   Metachunk* take_from_committed(size_t chunk_word_size);
 360 
 361   // Allocate a chunk from the virtual space and return it.
 362   Metachunk* get_chunk_vs(size_t chunk_word_size);
 363 
 364   // Expands/shrinks the committed space in a virtual space.  Delegates
 365   // to Virtualspace
 366   bool expand_by(size_t min_words, size_t preferred_words);
 367 
 368   // In preparation for deleting this node, remove all the chunks
 369   // in the node from any freelist.
 370   void purge(ChunkManager* chunk_manager);
 371 
 372   // If an allocation doesn't fit in the current node a new node is created.
 373   // Allocate chunks out of the remaining committed space in this node
 374   // to avoid wasting that memory.
 375   // This always adds up because all the chunk sizes are multiples of
 376   // the smallest chunk size.
 377   void retire(ChunkManager* chunk_manager);
 378 
 379 #ifdef ASSERT
 380   // Debug support
 381   void mangle();
 382 #endif
 383 
 384   void print_on(outputStream* st) const;
 385 };
 386 
 387 #define assert_is_ptr_aligned(ptr, alignment) \
 388   assert(is_ptr_aligned(ptr, alignment),      \
 389     err_msg(PTR_FORMAT " is not aligned to "  \
 390       SIZE_FORMAT, ptr, alignment))
 391 
 392 #define assert_is_size_aligned(size, alignment) \
 393   assert(is_size_aligned(size, alignment),      \
 394     err_msg(SIZE_FORMAT " is not aligned to "   \
 395        SIZE_FORMAT, size, alignment))
 396 
 397 
 398 // Decide if large pages should be committed when the memory is reserved.
 399 static bool should_commit_large_pages_when_reserving(size_t bytes) {
 400   if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) {
 401     size_t words = bytes / BytesPerWord;
 402     bool is_class = false; // We never reserve large pages for the class space.
 403     if (MetaspaceGC::can_expand(words, is_class) &&
 404         MetaspaceGC::allowed_expansion() >= words) {
 405       return true;
 406     }
 407   }
 408 
 409   return false;
 410 }
 411 
 412   // byte_size is the size of the associated virtualspace.
 413 VirtualSpaceNode::VirtualSpaceNode(size_t bytes) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
 414   assert_is_size_aligned(bytes, Metaspace::reserve_alignment());
 415 
 416 #if INCLUDE_CDS
 417   // This allocates memory with mmap.  For DumpSharedspaces, try to reserve
 418   // configurable address, generally at the top of the Java heap so other
 419   // memory addresses don't conflict.
 420   if (DumpSharedSpaces) {
 421     bool large_pages = false; // No large pages when dumping the CDS archive.
 422     char* shared_base = (char*)align_ptr_up((char*)SharedBaseAddress, Metaspace::reserve_alignment());
 423 
 424     _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages, shared_base);
 425     if (_rs.is_reserved()) {
 426       assert(shared_base == 0 || _rs.base() == shared_base, "should match");
 427     } else {
 428       // Get a mmap region anywhere if the SharedBaseAddress fails.
 429       _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
 430     }
 431     MetaspaceShared::set_shared_rs(&_rs);
 432   } else
 433 #endif
 434   {
 435     bool large_pages = should_commit_large_pages_when_reserving(bytes);
 436 
 437     _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
 438   }
 439 
 440   if (_rs.is_reserved()) {
 441     assert(_rs.base() != NULL, "Catch if we get a NULL address");
 442     assert(_rs.size() != 0, "Catch if we get a 0 size");
 443     assert_is_ptr_aligned(_rs.base(), Metaspace::reserve_alignment());
 444     assert_is_size_aligned(_rs.size(), Metaspace::reserve_alignment());
 445 
 446     MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
 447   }
 448 }
 449 
 450 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
 451   Metachunk* chunk = first_chunk();
 452   Metachunk* invalid_chunk = (Metachunk*) top();
 453   while (chunk < invalid_chunk ) {
 454     assert(chunk->is_tagged_free(), "Should be tagged free");
 455     MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
 456     chunk_manager->remove_chunk(chunk);
 457     assert(chunk->next() == NULL &&
 458            chunk->prev() == NULL,
 459            "Was not removed from its list");
 460     chunk = (Metachunk*) next;
 461   }
 462 }
 463 
 464 #ifdef ASSERT
 465 uint VirtualSpaceNode::container_count_slow() {
 466   uint count = 0;
 467   Metachunk* chunk = first_chunk();
 468   Metachunk* invalid_chunk = (Metachunk*) top();
 469   while (chunk < invalid_chunk ) {
 470     MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
 471     // Don't count the chunks on the free lists.  Those are
 472     // still part of the VirtualSpaceNode but not currently
 473     // counted.
 474     if (!chunk->is_tagged_free()) {
 475       count++;
 476     }
 477     chunk = (Metachunk*) next;
 478   }
 479   return count;
 480 }
 481 #endif
 482 
 483 // List of VirtualSpaces for metadata allocation.
 484 class VirtualSpaceList : public CHeapObj<mtClass> {
 485   friend class VirtualSpaceNode;
 486 
 487   enum VirtualSpaceSizes {
 488     VirtualSpaceSize = 256 * K
 489   };
 490 
 491   // Head of the list
 492   VirtualSpaceNode* _virtual_space_list;
 493   // virtual space currently being used for allocations
 494   VirtualSpaceNode* _current_virtual_space;
 495 
 496   // Is this VirtualSpaceList used for the compressed class space
 497   bool _is_class;
 498 
 499   // Sum of reserved and committed memory in the virtual spaces
 500   size_t _reserved_words;
 501   size_t _committed_words;
 502 
 503   // Number of virtual spaces
 504   size_t _virtual_space_count;
 505 
 506   ~VirtualSpaceList();
 507 
 508   VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
 509 
 510   void set_virtual_space_list(VirtualSpaceNode* v) {
 511     _virtual_space_list = v;
 512   }
 513   void set_current_virtual_space(VirtualSpaceNode* v) {
 514     _current_virtual_space = v;
 515   }
 516 
 517   void link_vs(VirtualSpaceNode* new_entry);
 518 
 519   // Get another virtual space and add it to the list.  This
 520   // is typically prompted by a failed attempt to allocate a chunk
 521   // and is typically followed by the allocation of a chunk.
 522   bool create_new_virtual_space(size_t vs_word_size);
 523 
 524   // Chunk up the unused committed space in the current
 525   // virtual space and add the chunks to the free list.
 526   void retire_current_virtual_space();
 527 
 528  public:
 529   VirtualSpaceList(size_t word_size);
 530   VirtualSpaceList(ReservedSpace rs);
 531 
 532   size_t free_bytes();
 533 
 534   Metachunk* get_new_chunk(size_t word_size,
 535                            size_t grow_chunks_by_words,
 536                            size_t medium_chunk_bunch);
 537 
 538   bool expand_node_by(VirtualSpaceNode* node,
 539                       size_t min_words,
 540                       size_t preferred_words);
 541 
 542   bool expand_by(size_t min_words,
 543                  size_t preferred_words);
 544 
 545   VirtualSpaceNode* current_virtual_space() {
 546     return _current_virtual_space;
 547   }
 548 
 549   bool is_class() const { return _is_class; }
 550 
 551   bool initialization_succeeded() { return _virtual_space_list != NULL; }
 552 
 553   size_t reserved_words()  { return _reserved_words; }
 554   size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
 555   size_t committed_words() { return _committed_words; }
 556   size_t committed_bytes() { return committed_words() * BytesPerWord; }
 557 
 558   void inc_reserved_words(size_t v);
 559   void dec_reserved_words(size_t v);
 560   void inc_committed_words(size_t v);
 561   void dec_committed_words(size_t v);
 562   void inc_virtual_space_count();
 563   void dec_virtual_space_count();
 564 
 565   bool contains(const void* ptr);
 566 
 567   // Unlink empty VirtualSpaceNodes and free it.
 568   void purge(ChunkManager* chunk_manager);
 569 
 570   void print_on(outputStream* st) const;
 571 
 572   class VirtualSpaceListIterator : public StackObj {
 573     VirtualSpaceNode* _virtual_spaces;
 574    public:
 575     VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
 576       _virtual_spaces(virtual_spaces) {}
 577 
 578     bool repeat() {
 579       return _virtual_spaces != NULL;
 580     }
 581 
 582     VirtualSpaceNode* get_next() {
 583       VirtualSpaceNode* result = _virtual_spaces;
 584       if (_virtual_spaces != NULL) {
 585         _virtual_spaces = _virtual_spaces->next();
 586       }
 587       return result;
 588     }
 589   };
 590 };
 591 
 592 class Metadebug : AllStatic {
 593   // Debugging support for Metaspaces
 594   static int _allocation_fail_alot_count;
 595 
 596  public:
 597 
 598   static void init_allocation_fail_alot_count();
 599 #ifdef ASSERT
 600   static bool test_metadata_failure();
 601 #endif
 602 };
 603 
 604 int Metadebug::_allocation_fail_alot_count = 0;
 605 
 606 //  SpaceManager - used by Metaspace to handle allocations
 607 class SpaceManager : public CHeapObj<mtClass> {
 608   friend class Metaspace;
 609   friend class Metadebug;
 610 
 611  private:
 612 
 613   // protects allocations
 614   Mutex* const _lock;
 615 
 616   // Type of metadata allocated.
 617   Metaspace::MetadataType _mdtype;
 618 
 619   // List of chunks in use by this SpaceManager.  Allocations
 620   // are done from the current chunk.  The list is used for deallocating
 621   // chunks when the SpaceManager is freed.
 622   Metachunk* _chunks_in_use[NumberOfInUseLists];
 623   Metachunk* _current_chunk;
 624 
 625   // Number of small chunks to allocate to a manager
 626   // If class space manager, small chunks are unlimited
 627   static uint const _small_chunk_limit;
 628 
 629   // Sum of all space in allocated chunks
 630   size_t _allocated_blocks_words;
 631 
 632   // Sum of all allocated chunks
 633   size_t _allocated_chunks_words;
 634   size_t _allocated_chunks_count;
 635 
 636   // Free lists of blocks are per SpaceManager since they
 637   // are assumed to be in chunks in use by the SpaceManager
 638   // and all chunks in use by a SpaceManager are freed when
 639   // the class loader using the SpaceManager is collected.
 640   BlockFreelist _block_freelists;
 641 
 642   // protects virtualspace and chunk expansions
 643   static const char*  _expand_lock_name;
 644   static const int    _expand_lock_rank;
 645   static Mutex* const _expand_lock;
 646 
 647  private:
 648   // Accessors
 649   Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
 650   void set_chunks_in_use(ChunkIndex index, Metachunk* v) {
 651     _chunks_in_use[index] = v;
 652   }
 653 
 654   BlockFreelist* block_freelists() const {
 655     return (BlockFreelist*) &_block_freelists;
 656   }
 657 
 658   Metaspace::MetadataType mdtype() { return _mdtype; }
 659 
 660   VirtualSpaceList* vs_list()   const { return Metaspace::get_space_list(_mdtype); }
 661   ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
 662 
 663   Metachunk* current_chunk() const { return _current_chunk; }
 664   void set_current_chunk(Metachunk* v) {
 665     _current_chunk = v;
 666   }
 667 
 668   Metachunk* find_current_chunk(size_t word_size);
 669 
 670   // Add chunk to the list of chunks in use
 671   void add_chunk(Metachunk* v, bool make_current);
 672   void retire_current_chunk();
 673 
 674   Mutex* lock() const { return _lock; }
 675 
 676   const char* chunk_size_name(ChunkIndex index) const;
 677 
 678  protected:
 679   void initialize();
 680 
 681  public:
 682   SpaceManager(Metaspace::MetadataType mdtype,
 683                Mutex* lock);
 684   ~SpaceManager();
 685 
 686   enum ChunkMultiples {
 687     MediumChunkMultiple = 4
 688   };
 689 
 690   bool is_class() { return _mdtype == Metaspace::ClassType; }
 691 
 692   // Accessors
 693   size_t specialized_chunk_size() { return (size_t) is_class() ? ClassSpecializedChunk : SpecializedChunk; }
 694   size_t small_chunk_size()       { return (size_t) is_class() ? ClassSmallChunk : SmallChunk; }
 695   size_t medium_chunk_size()      { return (size_t) is_class() ? ClassMediumChunk : MediumChunk; }
 696   size_t medium_chunk_bunch()     { return medium_chunk_size() * MediumChunkMultiple; }
 697 
 698   size_t smallest_chunk_size()  { return specialized_chunk_size(); }
 699 
 700   size_t allocated_blocks_words() const { return _allocated_blocks_words; }
 701   size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; }
 702   size_t allocated_chunks_words() const { return _allocated_chunks_words; }
 703   size_t allocated_chunks_bytes() const { return _allocated_chunks_words * BytesPerWord; }
 704   size_t allocated_chunks_count() const { return _allocated_chunks_count; }
 705 
 706   bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
 707 
 708   static Mutex* expand_lock() { return _expand_lock; }
 709 
 710   // Increment the per Metaspace and global running sums for Metachunks
 711   // by the given size.  This is used when a Metachunk to added to
 712   // the in-use list.
 713   void inc_size_metrics(size_t words);
 714   // Increment the per Metaspace and global running sums Metablocks by the given
 715   // size.  This is used when a Metablock is allocated.
 716   void inc_used_metrics(size_t words);
 717   // Delete the portion of the running sums for this SpaceManager. That is,
 718   // the globals running sums for the Metachunks and Metablocks are
 719   // decremented for all the Metachunks in-use by this SpaceManager.
 720   void dec_total_from_size_metrics();
 721 
 722   // Set the sizes for the initial chunks.
 723   void get_initial_chunk_sizes(Metaspace::MetaspaceType type,
 724                                size_t* chunk_word_size,
 725                                size_t* class_chunk_word_size);
 726 
 727   size_t sum_capacity_in_chunks_in_use() const;
 728   size_t sum_used_in_chunks_in_use() const;
 729   size_t sum_free_in_chunks_in_use() const;
 730   size_t sum_waste_in_chunks_in_use() const;
 731   size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
 732 
 733   size_t sum_count_in_chunks_in_use();
 734   size_t sum_count_in_chunks_in_use(ChunkIndex i);
 735 
 736   Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
 737 
 738   // Block allocation and deallocation.
 739   // Allocates a block from the current chunk
 740   MetaWord* allocate(size_t word_size);
 741 
 742   // Helper for allocations
 743   MetaWord* allocate_work(size_t word_size);
 744 
 745   // Returns a block to the per manager freelist
 746   void deallocate(MetaWord* p, size_t word_size);
 747 
 748   // Based on the allocation size and a minimum chunk size,
 749   // returned chunk size (for expanding space for chunk allocation).
 750   size_t calc_chunk_size(size_t allocation_word_size);
 751 
 752   // Called when an allocation from the current chunk fails.
 753   // Gets a new chunk (may require getting a new virtual space),
 754   // and allocates from that chunk.
 755   MetaWord* grow_and_allocate(size_t word_size);
 756 
 757   // Notify memory usage to MemoryService.
 758   void track_metaspace_memory_usage();
 759 
 760   // debugging support.
 761 
 762   void dump(outputStream* const out) const;
 763   void print_on(outputStream* st) const;
 764   void locked_print_chunks_in_use_on(outputStream* st) const;
 765 
 766   void verify();
 767   void verify_chunk_size(Metachunk* chunk);
 768   NOT_PRODUCT(void mangle_freed_chunks();)
 769 #ifdef ASSERT
 770   void verify_allocated_blocks_words();
 771 #endif
 772 
 773   size_t get_raw_word_size(size_t word_size) {
 774     size_t byte_size = word_size * BytesPerWord;
 775 
 776     size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
 777     raw_bytes_size = align_size_up(raw_bytes_size, Metachunk::object_alignment());
 778 
 779     size_t raw_word_size = raw_bytes_size / BytesPerWord;
 780     assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
 781 
 782     return raw_word_size;
 783   }
 784 };
 785 
 786 uint const SpaceManager::_small_chunk_limit = 4;
 787 
 788 const char* SpaceManager::_expand_lock_name =
 789   "SpaceManager chunk allocation lock";
 790 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
 791 Mutex* const SpaceManager::_expand_lock =
 792   new Mutex(SpaceManager::_expand_lock_rank,
 793             SpaceManager::_expand_lock_name,
 794             Mutex::_allow_vm_block_flag);
 795 
 796 void VirtualSpaceNode::inc_container_count() {
 797   assert_lock_strong(SpaceManager::expand_lock());
 798   _container_count++;
 799   assert(_container_count == container_count_slow(),
 800          err_msg("Inconsistency in container_count _container_count " SIZE_FORMAT
 801                  " container_count_slow() " SIZE_FORMAT,
 802                  _container_count, container_count_slow()));
 803 }
 804 
 805 void VirtualSpaceNode::dec_container_count() {
 806   assert_lock_strong(SpaceManager::expand_lock());
 807   _container_count--;
 808 }
 809 
 810 #ifdef ASSERT
 811 void VirtualSpaceNode::verify_container_count() {
 812   assert(_container_count == container_count_slow(),
 813     err_msg("Inconsistency in container_count _container_count " SIZE_FORMAT
 814             " container_count_slow() " SIZE_FORMAT, _container_count, container_count_slow()));
 815 }
 816 #endif
 817 
 818 // BlockFreelist methods
 819 
 820 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
 821 
 822 BlockFreelist::~BlockFreelist() {
 823   if (_dictionary != NULL) {
 824     if (Verbose && TraceMetadataChunkAllocation) {
 825       _dictionary->print_free_lists(gclog_or_tty);
 826     }
 827     delete _dictionary;
 828   }
 829 }
 830 
 831 void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
 832   Metablock* free_chunk = ::new (p) Metablock(word_size);
 833   if (dictionary() == NULL) {
 834    _dictionary = new BlockTreeDictionary();
 835   }
 836   dictionary()->return_chunk(free_chunk);
 837 }
 838 
 839 MetaWord* BlockFreelist::get_block(size_t word_size) {
 840   if (dictionary() == NULL) {
 841     return NULL;
 842   }
 843 
 844   if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 845     // Dark matter.  Too small for dictionary.
 846     return NULL;
 847   }
 848 
 849   Metablock* free_block =
 850     dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::atLeast);
 851   if (free_block == NULL) {
 852     return NULL;
 853   }
 854 
 855   const size_t block_size = free_block->size();
 856   if (block_size > WasteMultiplier * word_size) {
 857     return_block((MetaWord*)free_block, block_size);
 858     return NULL;
 859   }
 860 
 861   MetaWord* new_block = (MetaWord*)free_block;
 862   assert(block_size >= word_size, "Incorrect size of block from freelist");
 863   const size_t unused = block_size - word_size;
 864   if (unused >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
 865     return_block(new_block + word_size, unused);
 866   }
 867 
 868   return new_block;
 869 }
 870 
 871 void BlockFreelist::print_on(outputStream* st) const {
 872   if (dictionary() == NULL) {
 873     return;
 874   }
 875   dictionary()->print_free_lists(st);
 876 }
 877 
 878 // VirtualSpaceNode methods
 879 
 880 VirtualSpaceNode::~VirtualSpaceNode() {
 881   _rs.release();
 882 #ifdef ASSERT
 883   size_t word_size = sizeof(*this) / BytesPerWord;
 884   Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
 885 #endif
 886 }
 887 
 888 size_t VirtualSpaceNode::used_words_in_vs() const {
 889   return pointer_delta(top(), bottom(), sizeof(MetaWord));
 890 }
 891 
 892 // Space committed in the VirtualSpace
 893 size_t VirtualSpaceNode::capacity_words_in_vs() const {
 894   return pointer_delta(end(), bottom(), sizeof(MetaWord));
 895 }
 896 
 897 size_t VirtualSpaceNode::free_words_in_vs() const {
 898   return pointer_delta(end(), top(), sizeof(MetaWord));
 899 }
 900 
 901 // Allocates the chunk from the virtual space only.
 902 // This interface is also used internally for debugging.  Not all
 903 // chunks removed here are necessarily used for allocation.
 904 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
 905   // Bottom of the new chunk
 906   MetaWord* chunk_limit = top();
 907   assert(chunk_limit != NULL, "Not safe to call this method");
 908 
 909   // The virtual spaces are always expanded by the
 910   // commit granularity to enforce the following condition.
 911   // Without this the is_available check will not work correctly.
 912   assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
 913       "The committed memory doesn't match the expanded memory.");
 914 
 915   if (!is_available(chunk_word_size)) {
 916     if (TraceMetadataChunkAllocation) {
 917       gclog_or_tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
 918       // Dump some information about the virtual space that is nearly full
 919       print_on(gclog_or_tty);
 920     }
 921     return NULL;
 922   }
 923 
 924   // Take the space  (bump top on the current virtual space).
 925   inc_top(chunk_word_size);
 926 
 927   // Initialize the chunk
 928   Metachunk* result = ::new (chunk_limit) Metachunk(chunk_word_size, this);
 929   return result;
 930 }
 931 
 932 
 933 // Expand the virtual space (commit more of the reserved space)
 934 bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
 935   size_t min_bytes = min_words * BytesPerWord;
 936   size_t preferred_bytes = preferred_words * BytesPerWord;
 937 
 938   size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
 939 
 940   if (uncommitted < min_bytes) {
 941     return false;
 942   }
 943 
 944   size_t commit = MIN2(preferred_bytes, uncommitted);
 945   bool result = virtual_space()->expand_by(commit, false);
 946 
 947   assert(result, "Failed to commit memory");
 948 
 949   return result;
 950 }
 951 
 952 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
 953   assert_lock_strong(SpaceManager::expand_lock());
 954   Metachunk* result = take_from_committed(chunk_word_size);
 955   if (result != NULL) {
 956     inc_container_count();
 957   }
 958   return result;
 959 }
 960 
 961 bool VirtualSpaceNode::initialize() {
 962 
 963   if (!_rs.is_reserved()) {
 964     return false;
 965   }
 966 
 967   // These are necessary restriction to make sure that the virtual space always
 968   // grows in steps of Metaspace::commit_alignment(). If both base and size are
 969   // aligned only the middle alignment of the VirtualSpace is used.
 970   assert_is_ptr_aligned(_rs.base(), Metaspace::commit_alignment());
 971   assert_is_size_aligned(_rs.size(), Metaspace::commit_alignment());
 972 
 973   // ReservedSpaces marked as special will have the entire memory
 974   // pre-committed. Setting a committed size will make sure that
 975   // committed_size and actual_committed_size agrees.
 976   size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
 977 
 978   bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
 979                                             Metaspace::commit_alignment());
 980   if (result) {
 981     assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
 982         "Checking that the pre-committed memory was registered by the VirtualSpace");
 983 
 984     set_top((MetaWord*)virtual_space()->low());
 985     set_reserved(MemRegion((HeapWord*)_rs.base(),
 986                  (HeapWord*)(_rs.base() + _rs.size())));
 987 
 988     assert(reserved()->start() == (HeapWord*) _rs.base(),
 989       err_msg("Reserved start was not set properly " PTR_FORMAT
 990         " != " PTR_FORMAT, reserved()->start(), _rs.base()));
 991     assert(reserved()->word_size() == _rs.size() / BytesPerWord,
 992       err_msg("Reserved size was not set properly " SIZE_FORMAT
 993         " != " SIZE_FORMAT, reserved()->word_size(),
 994         _rs.size() / BytesPerWord));
 995   }
 996 
 997   return result;
 998 }
 999 
1000 void VirtualSpaceNode::print_on(outputStream* st) const {
1001   size_t used = used_words_in_vs();
1002   size_t capacity = capacity_words_in_vs();
1003   VirtualSpace* vs = virtual_space();
1004   st->print_cr("   space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
1005            "[" PTR_FORMAT ", " PTR_FORMAT ", "
1006            PTR_FORMAT ", " PTR_FORMAT ")",
1007            vs, capacity / K,
1008            capacity == 0 ? 0 : used * 100 / capacity,
1009            bottom(), top(), end(),
1010            vs->high_boundary());
1011 }
1012 
1013 #ifdef ASSERT
1014 void VirtualSpaceNode::mangle() {
1015   size_t word_size = capacity_words_in_vs();
1016   Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
1017 }
1018 #endif // ASSERT
1019 
1020 // VirtualSpaceList methods
1021 // Space allocated from the VirtualSpace
1022 
1023 VirtualSpaceList::~VirtualSpaceList() {
1024   VirtualSpaceListIterator iter(virtual_space_list());
1025   while (iter.repeat()) {
1026     VirtualSpaceNode* vsl = iter.get_next();
1027     delete vsl;
1028   }
1029 }
1030 
1031 void VirtualSpaceList::inc_reserved_words(size_t v) {
1032   assert_lock_strong(SpaceManager::expand_lock());
1033   _reserved_words = _reserved_words + v;
1034 }
1035 void VirtualSpaceList::dec_reserved_words(size_t v) {
1036   assert_lock_strong(SpaceManager::expand_lock());
1037   _reserved_words = _reserved_words - v;
1038 }
1039 
1040 #define assert_committed_below_limit()                             \
1041   assert(MetaspaceAux::committed_bytes() <= MaxMetaspaceSize,      \
1042       err_msg("Too much committed memory. Committed: " SIZE_FORMAT \
1043               " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
1044           MetaspaceAux::committed_bytes(), MaxMetaspaceSize));
1045 
1046 void VirtualSpaceList::inc_committed_words(size_t v) {
1047   assert_lock_strong(SpaceManager::expand_lock());
1048   _committed_words = _committed_words + v;
1049 
1050   assert_committed_below_limit();
1051 }
1052 void VirtualSpaceList::dec_committed_words(size_t v) {
1053   assert_lock_strong(SpaceManager::expand_lock());
1054   _committed_words = _committed_words - v;
1055 
1056   assert_committed_below_limit();
1057 }
1058 
1059 void VirtualSpaceList::inc_virtual_space_count() {
1060   assert_lock_strong(SpaceManager::expand_lock());
1061   _virtual_space_count++;
1062 }
1063 void VirtualSpaceList::dec_virtual_space_count() {
1064   assert_lock_strong(SpaceManager::expand_lock());
1065   _virtual_space_count--;
1066 }
1067 
1068 void ChunkManager::remove_chunk(Metachunk* chunk) {
1069   size_t word_size = chunk->word_size();
1070   ChunkIndex index = list_index(word_size);
1071   if (index != HumongousIndex) {
1072     free_chunks(index)->remove_chunk(chunk);
1073   } else {
1074     humongous_dictionary()->remove_chunk(chunk);
1075   }
1076 
1077   // Chunk is being removed from the chunks free list.
1078   dec_free_chunks_total(chunk->word_size());
1079 }
1080 
1081 // Walk the list of VirtualSpaceNodes and delete
1082 // nodes with a 0 container_count.  Remove Metachunks in
1083 // the node from their respective freelists.
1084 void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
1085   assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work");
1086   assert_lock_strong(SpaceManager::expand_lock());
1087   // Don't use a VirtualSpaceListIterator because this
1088   // list is being changed and a straightforward use of an iterator is not safe.
1089   VirtualSpaceNode* purged_vsl = NULL;
1090   VirtualSpaceNode* prev_vsl = virtual_space_list();
1091   VirtualSpaceNode* next_vsl = prev_vsl;
1092   while (next_vsl != NULL) {
1093     VirtualSpaceNode* vsl = next_vsl;
1094     next_vsl = vsl->next();
1095     // Don't free the current virtual space since it will likely
1096     // be needed soon.
1097     if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
1098       // Unlink it from the list
1099       if (prev_vsl == vsl) {
1100         // This is the case of the current node being the first node.
1101         assert(vsl == virtual_space_list(), "Expected to be the first node");
1102         set_virtual_space_list(vsl->next());
1103       } else {
1104         prev_vsl->set_next(vsl->next());
1105       }
1106 
1107       vsl->purge(chunk_manager);
1108       dec_reserved_words(vsl->reserved_words());
1109       dec_committed_words(vsl->committed_words());
1110       dec_virtual_space_count();
1111       purged_vsl = vsl;
1112       delete vsl;
1113     } else {
1114       prev_vsl = vsl;
1115     }
1116   }
1117 #ifdef ASSERT
1118   if (purged_vsl != NULL) {
1119     // List should be stable enough to use an iterator here.
1120     VirtualSpaceListIterator iter(virtual_space_list());
1121     while (iter.repeat()) {
1122       VirtualSpaceNode* vsl = iter.get_next();
1123       assert(vsl != purged_vsl, "Purge of vsl failed");
1124     }
1125   }
1126 #endif
1127 }
1128 
1129 
1130 // This function looks at the mmap regions in the metaspace without locking.
1131 // The chunks are added with store ordering and not deleted except for at
1132 // unloading time during a safepoint.
1133 bool VirtualSpaceList::contains(const void* ptr) {
1134   // List should be stable enough to use an iterator here because removing virtual
1135   // space nodes is only allowed at a safepoint.
1136   VirtualSpaceListIterator iter(virtual_space_list());
1137   while (iter.repeat()) {
1138     VirtualSpaceNode* vsn = iter.get_next();
1139     if (vsn->contains(ptr)) {
1140       return true;
1141     }
1142   }
1143   return false;
1144 }
1145 
1146 void VirtualSpaceList::retire_current_virtual_space() {
1147   assert_lock_strong(SpaceManager::expand_lock());
1148 
1149   VirtualSpaceNode* vsn = current_virtual_space();
1150 
1151   ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() :
1152                                   Metaspace::chunk_manager_metadata();
1153 
1154   vsn->retire(cm);
1155 }
1156 
1157 void VirtualSpaceNode::retire(ChunkManager* chunk_manager) {
1158   for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) {
1159     ChunkIndex index = (ChunkIndex)i;
1160     size_t chunk_size = chunk_manager->free_chunks(index)->size();
1161 
1162     while (free_words_in_vs() >= chunk_size) {
1163       DEBUG_ONLY(verify_container_count();)
1164       Metachunk* chunk = get_chunk_vs(chunk_size);
1165       assert(chunk != NULL, "allocation should have been successful");
1166 
1167       chunk_manager->return_chunks(index, chunk);
1168       chunk_manager->inc_free_chunks_total(chunk_size);
1169       DEBUG_ONLY(verify_container_count();)
1170     }
1171   }
1172   assert(free_words_in_vs() == 0, "should be empty now");
1173 }
1174 
1175 VirtualSpaceList::VirtualSpaceList(size_t word_size) :
1176                                    _is_class(false),
1177                                    _virtual_space_list(NULL),
1178                                    _current_virtual_space(NULL),
1179                                    _reserved_words(0),
1180                                    _committed_words(0),
1181                                    _virtual_space_count(0) {
1182   MutexLockerEx cl(SpaceManager::expand_lock(),
1183                    Mutex::_no_safepoint_check_flag);
1184   create_new_virtual_space(word_size);
1185 }
1186 
1187 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
1188                                    _is_class(true),
1189                                    _virtual_space_list(NULL),
1190                                    _current_virtual_space(NULL),
1191                                    _reserved_words(0),
1192                                    _committed_words(0),
1193                                    _virtual_space_count(0) {
1194   MutexLockerEx cl(SpaceManager::expand_lock(),
1195                    Mutex::_no_safepoint_check_flag);
1196   VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
1197   bool succeeded = class_entry->initialize();
1198   if (succeeded) {
1199     link_vs(class_entry);
1200   }
1201 }
1202 
1203 size_t VirtualSpaceList::free_bytes() {
1204   return virtual_space_list()->free_words_in_vs() * BytesPerWord;
1205 }
1206 
1207 // Allocate another meta virtual space and add it to the list.
1208 bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
1209   assert_lock_strong(SpaceManager::expand_lock());
1210 
1211   if (is_class()) {
1212     assert(false, "We currently don't support more than one VirtualSpace for"
1213                   " the compressed class space. The initialization of the"
1214                   " CCS uses another code path and should not hit this path.");
1215     return false;
1216   }
1217 
1218   if (vs_word_size == 0) {
1219     assert(false, "vs_word_size should always be at least _reserve_alignment large.");
1220     return false;
1221   }
1222 
1223   // Reserve the space
1224   size_t vs_byte_size = vs_word_size * BytesPerWord;
1225   assert_is_size_aligned(vs_byte_size, Metaspace::reserve_alignment());
1226 
1227   // Allocate the meta virtual space and initialize it.
1228   VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
1229   if (!new_entry->initialize()) {
1230     delete new_entry;
1231     return false;
1232   } else {
1233     assert(new_entry->reserved_words() == vs_word_size,
1234         "Reserved memory size differs from requested memory size");
1235     // ensure lock-free iteration sees fully initialized node
1236     OrderAccess::storestore();
1237     link_vs(new_entry);
1238     return true;
1239   }
1240 }
1241 
1242 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
1243   if (virtual_space_list() == NULL) {
1244       set_virtual_space_list(new_entry);
1245   } else {
1246     current_virtual_space()->set_next(new_entry);
1247   }
1248   set_current_virtual_space(new_entry);
1249   inc_reserved_words(new_entry->reserved_words());
1250   inc_committed_words(new_entry->committed_words());
1251   inc_virtual_space_count();
1252 #ifdef ASSERT
1253   new_entry->mangle();
1254 #endif
1255   if (TraceMetavirtualspaceAllocation && Verbose) {
1256     VirtualSpaceNode* vsl = current_virtual_space();
1257     vsl->print_on(gclog_or_tty);
1258   }
1259 }
1260 
1261 bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
1262                                       size_t min_words,
1263                                       size_t preferred_words) {
1264   size_t before = node->committed_words();
1265 
1266   bool result = node->expand_by(min_words, preferred_words);
1267 
1268   size_t after = node->committed_words();
1269 
1270   // after and before can be the same if the memory was pre-committed.
1271   assert(after >= before, "Inconsistency");
1272   inc_committed_words(after - before);
1273 
1274   return result;
1275 }
1276 
1277 bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
1278   assert_is_size_aligned(min_words,       Metaspace::commit_alignment_words());
1279   assert_is_size_aligned(preferred_words, Metaspace::commit_alignment_words());
1280   assert(min_words <= preferred_words, "Invalid arguments");
1281 
1282   if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
1283     return  false;
1284   }
1285 
1286   size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
1287   if (allowed_expansion_words < min_words) {
1288     return false;
1289   }
1290 
1291   size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
1292 
1293   // Commit more memory from the the current virtual space.
1294   bool vs_expanded = expand_node_by(current_virtual_space(),
1295                                     min_words,
1296                                     max_expansion_words);
1297   if (vs_expanded) {
1298     return true;
1299   }
1300   retire_current_virtual_space();
1301 
1302   // Get another virtual space.
1303   size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
1304   grow_vs_words = align_size_up(grow_vs_words, Metaspace::reserve_alignment_words());
1305 
1306   if (create_new_virtual_space(grow_vs_words)) {
1307     if (current_virtual_space()->is_pre_committed()) {
1308       // The memory was pre-committed, so we are done here.
1309       assert(min_words <= current_virtual_space()->committed_words(),
1310           "The new VirtualSpace was pre-committed, so it"
1311           "should be large enough to fit the alloc request.");
1312       return true;
1313     }
1314 
1315     return expand_node_by(current_virtual_space(),
1316                           min_words,
1317                           max_expansion_words);
1318   }
1319 
1320   return false;
1321 }
1322 
1323 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
1324                                            size_t grow_chunks_by_words,
1325                                            size_t medium_chunk_bunch) {
1326 
1327   // Allocate a chunk out of the current virtual space.
1328   Metachunk* next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1329 
1330   if (next != NULL) {
1331     return next;
1332   }
1333 
1334   // The expand amount is currently only determined by the requested sizes
1335   // and not how much committed memory is left in the current virtual space.
1336 
1337   size_t min_word_size       = align_size_up(grow_chunks_by_words, Metaspace::commit_alignment_words());
1338   size_t preferred_word_size = align_size_up(medium_chunk_bunch,   Metaspace::commit_alignment_words());
1339   if (min_word_size >= preferred_word_size) {
1340     // Can happen when humongous chunks are allocated.
1341     preferred_word_size = min_word_size;
1342   }
1343 
1344   bool expanded = expand_by(min_word_size, preferred_word_size);
1345   if (expanded) {
1346     next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1347     assert(next != NULL, "The allocation was expected to succeed after the expansion");
1348   }
1349 
1350    return next;
1351 }
1352 
1353 void VirtualSpaceList::print_on(outputStream* st) const {
1354   if (TraceMetadataChunkAllocation && Verbose) {
1355     VirtualSpaceListIterator iter(virtual_space_list());
1356     while (iter.repeat()) {
1357       VirtualSpaceNode* node = iter.get_next();
1358       node->print_on(st);
1359     }
1360   }
1361 }
1362 
1363 // MetaspaceGC methods
1364 
1365 // VM_CollectForMetadataAllocation is the vm operation used to GC.
1366 // Within the VM operation after the GC the attempt to allocate the metadata
1367 // should succeed.  If the GC did not free enough space for the metaspace
1368 // allocation, the HWM is increased so that another virtualspace will be
1369 // allocated for the metadata.  With perm gen the increase in the perm
1370 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion.  The
1371 // metaspace policy uses those as the small and large steps for the HWM.
1372 //
1373 // After the GC the compute_new_size() for MetaspaceGC is called to
1374 // resize the capacity of the metaspaces.  The current implementation
1375 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
1376 // to resize the Java heap by some GC's.  New flags can be implemented
1377 // if really needed.  MinMetaspaceFreeRatio is used to calculate how much
1378 // free space is desirable in the metaspace capacity to decide how much
1379 // to increase the HWM.  MaxMetaspaceFreeRatio is used to decide how much
1380 // free space is desirable in the metaspace capacity before decreasing
1381 // the HWM.
1382 
1383 // Calculate the amount to increase the high water mark (HWM).
1384 // Increase by a minimum amount (MinMetaspaceExpansion) so that
1385 // another expansion is not requested too soon.  If that is not
1386 // enough to satisfy the allocation, increase by MaxMetaspaceExpansion.
1387 // If that is still not enough, expand by the size of the allocation
1388 // plus some.
1389 size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) {
1390   size_t min_delta = MinMetaspaceExpansion;
1391   size_t max_delta = MaxMetaspaceExpansion;
1392   size_t delta = align_size_up(bytes, Metaspace::commit_alignment());
1393 
1394   if (delta <= min_delta) {
1395     delta = min_delta;
1396   } else if (delta <= max_delta) {
1397     // Don't want to hit the high water mark on the next
1398     // allocation so make the delta greater than just enough
1399     // for this allocation.
1400     delta = max_delta;
1401   } else {
1402     // This allocation is large but the next ones are probably not
1403     // so increase by the minimum.
1404     delta = delta + min_delta;
1405   }
1406 
1407   assert_is_size_aligned(delta, Metaspace::commit_alignment());
1408 
1409   return delta;
1410 }
1411 
1412 size_t MetaspaceGC::capacity_until_GC() {
1413   size_t value = (size_t)OrderAccess::load_ptr_acquire(&_capacity_until_GC);
1414   assert(value >= MetaspaceSize, "Not initialied properly?");
1415   return value;
1416 }
1417 
1418 bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) {
1419   assert_is_size_aligned(v, Metaspace::commit_alignment());
1420 
1421   size_t capacity_until_GC = (size_t) _capacity_until_GC;
1422   size_t new_value = capacity_until_GC + v;
1423 
1424   if (new_value < capacity_until_GC) {
1425     // The addition wrapped around, set new_value to aligned max value.
1426     new_value = align_size_down(max_uintx, Metaspace::commit_alignment());
1427   }
1428 
1429   intptr_t expected = (intptr_t) capacity_until_GC;
1430   intptr_t actual = Atomic::cmpxchg_ptr((intptr_t) new_value, &_capacity_until_GC, expected);
1431 
1432   if (expected != actual) {
1433     return false;
1434   }
1435 
1436   if (new_cap_until_GC != NULL) {
1437     *new_cap_until_GC = new_value;
1438   }
1439   if (old_cap_until_GC != NULL) {
1440     *old_cap_until_GC = capacity_until_GC;
1441   }
1442   return true;
1443 }
1444 
1445 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
1446   assert_is_size_aligned(v, Metaspace::commit_alignment());
1447 
1448   return (size_t)Atomic::add_ptr(-(intptr_t)v, &_capacity_until_GC);
1449 }
1450 
1451 void MetaspaceGC::initialize() {
1452   // Set the high-water mark to MaxMetapaceSize during VM initializaton since
1453   // we can't do a GC during initialization.
1454   _capacity_until_GC = MaxMetaspaceSize;
1455 }
1456 
1457 void MetaspaceGC::post_initialize() {
1458   // Reset the high-water mark once the VM initialization is done.
1459   _capacity_until_GC = MAX2(MetaspaceAux::committed_bytes(), MetaspaceSize);
1460 }
1461 
1462 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
1463   // Check if the compressed class space is full.
1464   if (is_class && Metaspace::using_class_space()) {
1465     size_t class_committed = MetaspaceAux::committed_bytes(Metaspace::ClassType);
1466     if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
1467       return false;
1468     }
1469   }
1470 
1471   // Check if the user has imposed a limit on the metaspace memory.
1472   size_t committed_bytes = MetaspaceAux::committed_bytes();
1473   if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
1474     return false;
1475   }
1476 
1477   return true;
1478 }
1479 
1480 size_t MetaspaceGC::allowed_expansion() {
1481   size_t committed_bytes = MetaspaceAux::committed_bytes();
1482   size_t capacity_until_gc = capacity_until_GC();
1483 
1484   assert(capacity_until_gc >= committed_bytes,
1485         err_msg("capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT,
1486                 capacity_until_gc, committed_bytes));
1487 
1488   size_t left_until_max  = MaxMetaspaceSize - committed_bytes;
1489   size_t left_until_GC = capacity_until_gc - committed_bytes;
1490   size_t left_to_commit = MIN2(left_until_GC, left_until_max);
1491 
1492   return left_to_commit / BytesPerWord;
1493 }
1494 
1495 void MetaspaceGC::compute_new_size() {
1496   assert(_shrink_factor <= 100, "invalid shrink factor");
1497   uint current_shrink_factor = _shrink_factor;
1498   _shrink_factor = 0;
1499 
1500   // Using committed_bytes() for used_after_gc is an overestimation, since the
1501   // chunk free lists are included in committed_bytes() and the memory in an
1502   // un-fragmented chunk free list is available for future allocations.
1503   // However, if the chunk free lists becomes fragmented, then the memory may
1504   // not be available for future allocations and the memory is therefore "in use".
1505   // Including the chunk free lists in the definition of "in use" is therefore
1506   // necessary. Not including the chunk free lists can cause capacity_until_GC to
1507   // shrink below committed_bytes() and this has caused serious bugs in the past.
1508   const size_t used_after_gc = MetaspaceAux::committed_bytes();
1509   const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
1510 
1511   const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
1512   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
1513 
1514   const double min_tmp = used_after_gc / maximum_used_percentage;
1515   size_t minimum_desired_capacity =
1516     (size_t)MIN2(min_tmp, double(max_uintx));
1517   // Don't shrink less than the initial generation size
1518   minimum_desired_capacity = MAX2(minimum_desired_capacity,
1519                                   MetaspaceSize);
1520 
1521   if (PrintGCDetails && Verbose) {
1522     gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
1523     gclog_or_tty->print_cr("  "
1524                   "  minimum_free_percentage: %6.2f"
1525                   "  maximum_used_percentage: %6.2f",
1526                   minimum_free_percentage,
1527                   maximum_used_percentage);
1528     gclog_or_tty->print_cr("  "
1529                   "   used_after_gc       : %6.1fKB",
1530                   used_after_gc / (double) K);
1531   }
1532 
1533 
1534   size_t shrink_bytes = 0;
1535   if (capacity_until_GC < minimum_desired_capacity) {
1536     // If we have less capacity below the metaspace HWM, then
1537     // increment the HWM.
1538     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
1539     expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
1540     // Don't expand unless it's significant
1541     if (expand_bytes >= MinMetaspaceExpansion) {
1542       size_t new_capacity_until_GC = 0;
1543       bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC);
1544       assert(succeeded, "Should always succesfully increment HWM when at safepoint");
1545 
1546       Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1547                                                new_capacity_until_GC,
1548                                                MetaspaceGCThresholdUpdater::ComputeNewSize);
1549       if (PrintGCDetails && Verbose) {
1550         gclog_or_tty->print_cr("    expanding:"
1551                       "  minimum_desired_capacity: %6.1fKB"
1552                       "  expand_bytes: %6.1fKB"
1553                       "  MinMetaspaceExpansion: %6.1fKB"
1554                       "  new metaspace HWM:  %6.1fKB",
1555                       minimum_desired_capacity / (double) K,
1556                       expand_bytes / (double) K,
1557                       MinMetaspaceExpansion / (double) K,
1558                       new_capacity_until_GC / (double) K);
1559       }
1560     }
1561     return;
1562   }
1563 
1564   // No expansion, now see if we want to shrink
1565   // We would never want to shrink more than this
1566   assert(capacity_until_GC >= minimum_desired_capacity,
1567          err_msg(SIZE_FORMAT " >= " SIZE_FORMAT,
1568                  capacity_until_GC, minimum_desired_capacity));
1569   size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity;
1570 
1571   // Should shrinking be considered?
1572   if (MaxMetaspaceFreeRatio < 100) {
1573     const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0;
1574     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
1575     const double max_tmp = used_after_gc / minimum_used_percentage;
1576     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
1577     maximum_desired_capacity = MAX2(maximum_desired_capacity,
1578                                     MetaspaceSize);
1579     if (PrintGCDetails && Verbose) {
1580       gclog_or_tty->print_cr("  "
1581                              "  maximum_free_percentage: %6.2f"
1582                              "  minimum_used_percentage: %6.2f",
1583                              maximum_free_percentage,
1584                              minimum_used_percentage);
1585       gclog_or_tty->print_cr("  "
1586                              "  minimum_desired_capacity: %6.1fKB"
1587                              "  maximum_desired_capacity: %6.1fKB",
1588                              minimum_desired_capacity / (double) K,
1589                              maximum_desired_capacity / (double) K);
1590     }
1591 
1592     assert(minimum_desired_capacity <= maximum_desired_capacity,
1593            "sanity check");
1594 
1595     if (capacity_until_GC > maximum_desired_capacity) {
1596       // Capacity too large, compute shrinking size
1597       shrink_bytes = capacity_until_GC - maximum_desired_capacity;
1598       // We don't want shrink all the way back to initSize if people call
1599       // System.gc(), because some programs do that between "phases" and then
1600       // we'd just have to grow the heap up again for the next phase.  So we
1601       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
1602       // on the third call, and 100% by the fourth call.  But if we recompute
1603       // size without shrinking, it goes back to 0%.
1604       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
1605 
1606       shrink_bytes = align_size_down(shrink_bytes, Metaspace::commit_alignment());
1607 
1608       assert(shrink_bytes <= max_shrink_bytes,
1609         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
1610           shrink_bytes, max_shrink_bytes));
1611       if (current_shrink_factor == 0) {
1612         _shrink_factor = 10;
1613       } else {
1614         _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
1615       }
1616       if (PrintGCDetails && Verbose) {
1617         gclog_or_tty->print_cr("  "
1618                       "  shrinking:"
1619                       "  initSize: %.1fK"
1620                       "  maximum_desired_capacity: %.1fK",
1621                       MetaspaceSize / (double) K,
1622                       maximum_desired_capacity / (double) K);
1623         gclog_or_tty->print_cr("  "
1624                       "  shrink_bytes: %.1fK"
1625                       "  current_shrink_factor: %d"
1626                       "  new shrink factor: %d"
1627                       "  MinMetaspaceExpansion: %.1fK",
1628                       shrink_bytes / (double) K,
1629                       current_shrink_factor,
1630                       _shrink_factor,
1631                       MinMetaspaceExpansion / (double) K);
1632       }
1633     }
1634   }
1635 
1636   // Don't shrink unless it's significant
1637   if (shrink_bytes >= MinMetaspaceExpansion &&
1638       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
1639     size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
1640     Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
1641                                              new_capacity_until_GC,
1642                                              MetaspaceGCThresholdUpdater::ComputeNewSize);
1643   }
1644 }
1645 
1646 // Metadebug methods
1647 
1648 void Metadebug::init_allocation_fail_alot_count() {
1649   if (MetadataAllocationFailALot) {
1650     _allocation_fail_alot_count =
1651       1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
1652   }
1653 }
1654 
1655 #ifdef ASSERT
1656 bool Metadebug::test_metadata_failure() {
1657   if (MetadataAllocationFailALot &&
1658       Threads::is_vm_complete()) {
1659     if (_allocation_fail_alot_count > 0) {
1660       _allocation_fail_alot_count--;
1661     } else {
1662       if (TraceMetadataChunkAllocation && Verbose) {
1663         gclog_or_tty->print_cr("Metadata allocation failing for "
1664                                "MetadataAllocationFailALot");
1665       }
1666       init_allocation_fail_alot_count();
1667       return true;
1668     }
1669   }
1670   return false;
1671 }
1672 #endif
1673 
1674 // ChunkManager methods
1675 
1676 size_t ChunkManager::free_chunks_total_words() {
1677   return _free_chunks_total;
1678 }
1679 
1680 size_t ChunkManager::free_chunks_total_bytes() {
1681   return free_chunks_total_words() * BytesPerWord;
1682 }
1683 
1684 size_t ChunkManager::free_chunks_count() {
1685 #ifdef ASSERT
1686   if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1687     MutexLockerEx cl(SpaceManager::expand_lock(),
1688                      Mutex::_no_safepoint_check_flag);
1689     // This lock is only needed in debug because the verification
1690     // of the _free_chunks_totals walks the list of free chunks
1691     slow_locked_verify_free_chunks_count();
1692   }
1693 #endif
1694   return _free_chunks_count;
1695 }
1696 
1697 void ChunkManager::locked_verify_free_chunks_total() {
1698   assert_lock_strong(SpaceManager::expand_lock());
1699   assert(sum_free_chunks() == _free_chunks_total,
1700     err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
1701            " same as sum " SIZE_FORMAT, _free_chunks_total,
1702            sum_free_chunks()));
1703 }
1704 
1705 void ChunkManager::verify_free_chunks_total() {
1706   MutexLockerEx cl(SpaceManager::expand_lock(),
1707                      Mutex::_no_safepoint_check_flag);
1708   locked_verify_free_chunks_total();
1709 }
1710 
1711 void ChunkManager::locked_verify_free_chunks_count() {
1712   assert_lock_strong(SpaceManager::expand_lock());
1713   assert(sum_free_chunks_count() == _free_chunks_count,
1714     err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
1715            " same as sum " SIZE_FORMAT, _free_chunks_count,
1716            sum_free_chunks_count()));
1717 }
1718 
1719 void ChunkManager::verify_free_chunks_count() {
1720 #ifdef ASSERT
1721   MutexLockerEx cl(SpaceManager::expand_lock(),
1722                      Mutex::_no_safepoint_check_flag);
1723   locked_verify_free_chunks_count();
1724 #endif
1725 }
1726 
1727 void ChunkManager::verify() {
1728   MutexLockerEx cl(SpaceManager::expand_lock(),
1729                      Mutex::_no_safepoint_check_flag);
1730   locked_verify();
1731 }
1732 
1733 void ChunkManager::locked_verify() {
1734   locked_verify_free_chunks_count();
1735   locked_verify_free_chunks_total();
1736 }
1737 
1738 void ChunkManager::locked_print_free_chunks(outputStream* st) {
1739   assert_lock_strong(SpaceManager::expand_lock());
1740   st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1741                 _free_chunks_total, _free_chunks_count);
1742 }
1743 
1744 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
1745   assert_lock_strong(SpaceManager::expand_lock());
1746   st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
1747                 sum_free_chunks(), sum_free_chunks_count());
1748 }
1749 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
1750   return &_free_chunks[index];
1751 }
1752 
1753 // These methods that sum the free chunk lists are used in printing
1754 // methods that are used in product builds.
1755 size_t ChunkManager::sum_free_chunks() {
1756   assert_lock_strong(SpaceManager::expand_lock());
1757   size_t result = 0;
1758   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1759     ChunkList* list = free_chunks(i);
1760 
1761     if (list == NULL) {
1762       continue;
1763     }
1764 
1765     result = result + list->count() * list->size();
1766   }
1767   result = result + humongous_dictionary()->total_size();
1768   return result;
1769 }
1770 
1771 size_t ChunkManager::sum_free_chunks_count() {
1772   assert_lock_strong(SpaceManager::expand_lock());
1773   size_t count = 0;
1774   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1775     ChunkList* list = free_chunks(i);
1776     if (list == NULL) {
1777       continue;
1778     }
1779     count = count + list->count();
1780   }
1781   count = count + humongous_dictionary()->total_free_blocks();
1782   return count;
1783 }
1784 
1785 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
1786   ChunkIndex index = list_index(word_size);
1787   assert(index < HumongousIndex, "No humongous list");
1788   return free_chunks(index);
1789 }
1790 
1791 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
1792   assert_lock_strong(SpaceManager::expand_lock());
1793 
1794   slow_locked_verify();
1795 
1796   Metachunk* chunk = NULL;
1797   if (list_index(word_size) != HumongousIndex) {
1798     ChunkList* free_list = find_free_chunks_list(word_size);
1799     assert(free_list != NULL, "Sanity check");
1800 
1801     chunk = free_list->head();
1802 
1803     if (chunk == NULL) {
1804       return NULL;
1805     }
1806 
1807     // Remove the chunk as the head of the list.
1808     free_list->remove_chunk(chunk);
1809 
1810     if (TraceMetadataChunkAllocation && Verbose) {
1811       gclog_or_tty->print_cr("ChunkManager::free_chunks_get: free_list "
1812                              PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
1813                              free_list, chunk, chunk->word_size());
1814     }
1815   } else {
1816     chunk = humongous_dictionary()->get_chunk(
1817       word_size,
1818       FreeBlockDictionary<Metachunk>::atLeast);
1819 
1820     if (chunk == NULL) {
1821       return NULL;
1822     }
1823 
1824     if (TraceMetadataHumongousAllocation) {
1825       size_t waste = chunk->word_size() - word_size;
1826       gclog_or_tty->print_cr("Free list allocate humongous chunk size "
1827                              SIZE_FORMAT " for requested size " SIZE_FORMAT
1828                              " waste " SIZE_FORMAT,
1829                              chunk->word_size(), word_size, waste);
1830     }
1831   }
1832 
1833   // Chunk is being removed from the chunks free list.
1834   dec_free_chunks_total(chunk->word_size());
1835 
1836   // Remove it from the links to this freelist
1837   chunk->set_next(NULL);
1838   chunk->set_prev(NULL);
1839 #ifdef ASSERT
1840   // Chunk is no longer on any freelist. Setting to false make container_count_slow()
1841   // work.
1842   chunk->set_is_tagged_free(false);
1843 #endif
1844   chunk->container()->inc_container_count();
1845 
1846   slow_locked_verify();
1847   return chunk;
1848 }
1849 
1850 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
1851   assert_lock_strong(SpaceManager::expand_lock());
1852   slow_locked_verify();
1853 
1854   // Take from the beginning of the list
1855   Metachunk* chunk = free_chunks_get(word_size);
1856   if (chunk == NULL) {
1857     return NULL;
1858   }
1859 
1860   assert((word_size <= chunk->word_size()) ||
1861          list_index(chunk->word_size() == HumongousIndex),
1862          "Non-humongous variable sized chunk");
1863   if (TraceMetadataChunkAllocation) {
1864     size_t list_count;
1865     if (list_index(word_size) < HumongousIndex) {
1866       ChunkList* list = find_free_chunks_list(word_size);
1867       list_count = list->count();
1868     } else {
1869       list_count = humongous_dictionary()->total_count();
1870     }
1871     gclog_or_tty->print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk "
1872                         PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
1873                         this, chunk, chunk->word_size(), list_count);
1874     locked_print_free_chunks(gclog_or_tty);
1875   }
1876 
1877   return chunk;
1878 }
1879 
1880 void ChunkManager::print_on(outputStream* out) const {
1881   if (PrintFLSStatistics != 0) {
1882     const_cast<ChunkManager *>(this)->humongous_dictionary()->report_statistics();
1883   }
1884 }
1885 
1886 // SpaceManager methods
1887 
1888 void SpaceManager::get_initial_chunk_sizes(Metaspace::MetaspaceType type,
1889                                            size_t* chunk_word_size,
1890                                            size_t* class_chunk_word_size) {
1891   switch (type) {
1892   case Metaspace::BootMetaspaceType:
1893     *chunk_word_size = Metaspace::first_chunk_word_size();
1894     *class_chunk_word_size = Metaspace::first_class_chunk_word_size();
1895     break;
1896   case Metaspace::ROMetaspaceType:
1897     *chunk_word_size = SharedReadOnlySize / wordSize;
1898     *class_chunk_word_size = ClassSpecializedChunk;
1899     break;
1900   case Metaspace::ReadWriteMetaspaceType:
1901     *chunk_word_size = SharedReadWriteSize / wordSize;
1902     *class_chunk_word_size = ClassSpecializedChunk;
1903     break;
1904   case Metaspace::AnonymousMetaspaceType:
1905   case Metaspace::ReflectionMetaspaceType:
1906     *chunk_word_size = SpecializedChunk;
1907     *class_chunk_word_size = ClassSpecializedChunk;
1908     break;
1909   default:
1910     *chunk_word_size = SmallChunk;
1911     *class_chunk_word_size = ClassSmallChunk;
1912     break;
1913   }
1914   assert(*chunk_word_size != 0 && *class_chunk_word_size != 0,
1915     err_msg("Initial chunks sizes bad: data  " SIZE_FORMAT
1916             " class " SIZE_FORMAT,
1917             *chunk_word_size, *class_chunk_word_size));
1918 }
1919 
1920 size_t SpaceManager::sum_free_in_chunks_in_use() const {
1921   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1922   size_t free = 0;
1923   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1924     Metachunk* chunk = chunks_in_use(i);
1925     while (chunk != NULL) {
1926       free += chunk->free_word_size();
1927       chunk = chunk->next();
1928     }
1929   }
1930   return free;
1931 }
1932 
1933 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
1934   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1935   size_t result = 0;
1936   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1937    result += sum_waste_in_chunks_in_use(i);
1938   }
1939 
1940   return result;
1941 }
1942 
1943 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
1944   size_t result = 0;
1945   Metachunk* chunk = chunks_in_use(index);
1946   // Count the free space in all the chunk but not the
1947   // current chunk from which allocations are still being done.
1948   while (chunk != NULL) {
1949     if (chunk != current_chunk()) {
1950       result += chunk->free_word_size();
1951     }
1952     chunk = chunk->next();
1953   }
1954   return result;
1955 }
1956 
1957 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
1958   // For CMS use "allocated_chunks_words()" which does not need the
1959   // Metaspace lock.  For the other collectors sum over the
1960   // lists.  Use both methods as a check that "allocated_chunks_words()"
1961   // is correct.  That is, sum_capacity_in_chunks() is too expensive
1962   // to use in the product and allocated_chunks_words() should be used
1963   // but allow for  checking that allocated_chunks_words() returns the same
1964   // value as sum_capacity_in_chunks_in_use() which is the definitive
1965   // answer.
1966   if (UseConcMarkSweepGC) {
1967     return allocated_chunks_words();
1968   } else {
1969     MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1970     size_t sum = 0;
1971     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1972       Metachunk* chunk = chunks_in_use(i);
1973       while (chunk != NULL) {
1974         sum += chunk->word_size();
1975         chunk = chunk->next();
1976       }
1977     }
1978   return sum;
1979   }
1980 }
1981 
1982 size_t SpaceManager::sum_count_in_chunks_in_use() {
1983   size_t count = 0;
1984   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1985     count = count + sum_count_in_chunks_in_use(i);
1986   }
1987 
1988   return count;
1989 }
1990 
1991 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
1992   size_t count = 0;
1993   Metachunk* chunk = chunks_in_use(i);
1994   while (chunk != NULL) {
1995     count++;
1996     chunk = chunk->next();
1997   }
1998   return count;
1999 }
2000 
2001 
2002 size_t SpaceManager::sum_used_in_chunks_in_use() const {
2003   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2004   size_t used = 0;
2005   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2006     Metachunk* chunk = chunks_in_use(i);
2007     while (chunk != NULL) {
2008       used += chunk->used_word_size();
2009       chunk = chunk->next();
2010     }
2011   }
2012   return used;
2013 }
2014 
2015 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
2016 
2017   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2018     Metachunk* chunk = chunks_in_use(i);
2019     st->print("SpaceManager: %s " PTR_FORMAT,
2020                  chunk_size_name(i), chunk);
2021     if (chunk != NULL) {
2022       st->print_cr(" free " SIZE_FORMAT,
2023                    chunk->free_word_size());
2024     } else {
2025       st->cr();
2026     }
2027   }
2028 
2029   chunk_manager()->locked_print_free_chunks(st);
2030   chunk_manager()->locked_print_sum_free_chunks(st);
2031 }
2032 
2033 size_t SpaceManager::calc_chunk_size(size_t word_size) {
2034 
2035   // Decide between a small chunk and a medium chunk.  Up to
2036   // _small_chunk_limit small chunks can be allocated but
2037   // once a medium chunk has been allocated, no more small
2038   // chunks will be allocated.
2039   size_t chunk_word_size;
2040   if (chunks_in_use(MediumIndex) == NULL &&
2041       sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) {
2042     chunk_word_size = (size_t) small_chunk_size();
2043     if (word_size + Metachunk::overhead() > small_chunk_size()) {
2044       chunk_word_size = medium_chunk_size();
2045     }
2046   } else {
2047     chunk_word_size = medium_chunk_size();
2048   }
2049 
2050   // Might still need a humongous chunk.  Enforce
2051   // humongous allocations sizes to be aligned up to
2052   // the smallest chunk size.
2053   size_t if_humongous_sized_chunk =
2054     align_size_up(word_size + Metachunk::overhead(),
2055                   smallest_chunk_size());
2056   chunk_word_size =
2057     MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
2058 
2059   assert(!SpaceManager::is_humongous(word_size) ||
2060          chunk_word_size == if_humongous_sized_chunk,
2061          err_msg("Size calculation is wrong, word_size " SIZE_FORMAT
2062                  " chunk_word_size " SIZE_FORMAT,
2063                  word_size, chunk_word_size));
2064   if (TraceMetadataHumongousAllocation &&
2065       SpaceManager::is_humongous(word_size)) {
2066     gclog_or_tty->print_cr("Metadata humongous allocation:");
2067     gclog_or_tty->print_cr("  word_size " PTR_FORMAT, word_size);
2068     gclog_or_tty->print_cr("  chunk_word_size " PTR_FORMAT,
2069                            chunk_word_size);
2070     gclog_or_tty->print_cr("    chunk overhead " PTR_FORMAT,
2071                            Metachunk::overhead());
2072   }
2073   return chunk_word_size;
2074 }
2075 
2076 void SpaceManager::track_metaspace_memory_usage() {
2077   if (is_init_completed()) {
2078     if (is_class()) {
2079       MemoryService::track_compressed_class_memory_usage();
2080     }
2081     MemoryService::track_metaspace_memory_usage();
2082   }
2083 }
2084 
2085 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
2086   assert(vs_list()->current_virtual_space() != NULL,
2087          "Should have been set");
2088   assert(current_chunk() == NULL ||
2089          current_chunk()->allocate(word_size) == NULL,
2090          "Don't need to expand");
2091   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2092 
2093   if (TraceMetadataChunkAllocation && Verbose) {
2094     size_t words_left = 0;
2095     size_t words_used = 0;
2096     if (current_chunk() != NULL) {
2097       words_left = current_chunk()->free_word_size();
2098       words_used = current_chunk()->used_word_size();
2099     }
2100     gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
2101                            " words " SIZE_FORMAT " words used " SIZE_FORMAT
2102                            " words left",
2103                             word_size, words_used, words_left);
2104   }
2105 
2106   // Get another chunk out of the virtual space
2107   size_t grow_chunks_by_words = calc_chunk_size(word_size);
2108   Metachunk* next = get_new_chunk(word_size, grow_chunks_by_words);
2109 
2110   MetaWord* mem = NULL;
2111 
2112   // If a chunk was available, add it to the in-use chunk list
2113   // and do an allocation from it.
2114   if (next != NULL) {
2115     // Add to this manager's list of chunks in use.
2116     add_chunk(next, false);
2117     mem = next->allocate(word_size);
2118   }
2119 
2120   // Track metaspace memory usage statistic.
2121   track_metaspace_memory_usage();
2122 
2123   return mem;
2124 }
2125 
2126 void SpaceManager::print_on(outputStream* st) const {
2127 
2128   for (ChunkIndex i = ZeroIndex;
2129        i < NumberOfInUseLists ;
2130        i = next_chunk_index(i) ) {
2131     st->print_cr("  chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
2132                  chunks_in_use(i),
2133                  chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
2134   }
2135   st->print_cr("    waste:  Small " SIZE_FORMAT " Medium " SIZE_FORMAT
2136                " Humongous " SIZE_FORMAT,
2137                sum_waste_in_chunks_in_use(SmallIndex),
2138                sum_waste_in_chunks_in_use(MediumIndex),
2139                sum_waste_in_chunks_in_use(HumongousIndex));
2140   // block free lists
2141   if (block_freelists() != NULL) {
2142     st->print_cr("total in block free lists " SIZE_FORMAT,
2143       block_freelists()->total_size());
2144   }
2145 }
2146 
2147 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
2148                            Mutex* lock) :
2149   _mdtype(mdtype),
2150   _allocated_blocks_words(0),
2151   _allocated_chunks_words(0),
2152   _allocated_chunks_count(0),
2153   _lock(lock)
2154 {
2155   initialize();
2156 }
2157 
2158 void SpaceManager::inc_size_metrics(size_t words) {
2159   assert_lock_strong(SpaceManager::expand_lock());
2160   // Total of allocated Metachunks and allocated Metachunks count
2161   // for each SpaceManager
2162   _allocated_chunks_words = _allocated_chunks_words + words;
2163   _allocated_chunks_count++;
2164   // Global total of capacity in allocated Metachunks
2165   MetaspaceAux::inc_capacity(mdtype(), words);
2166   // Global total of allocated Metablocks.
2167   // used_words_slow() includes the overhead in each
2168   // Metachunk so include it in the used when the
2169   // Metachunk is first added (so only added once per
2170   // Metachunk).
2171   MetaspaceAux::inc_used(mdtype(), Metachunk::overhead());
2172 }
2173 
2174 void SpaceManager::inc_used_metrics(size_t words) {
2175   // Add to the per SpaceManager total
2176   Atomic::add_ptr(words, &_allocated_blocks_words);
2177   // Add to the global total
2178   MetaspaceAux::inc_used(mdtype(), words);
2179 }
2180 
2181 void SpaceManager::dec_total_from_size_metrics() {
2182   MetaspaceAux::dec_capacity(mdtype(), allocated_chunks_words());
2183   MetaspaceAux::dec_used(mdtype(), allocated_blocks_words());
2184   // Also deduct the overhead per Metachunk
2185   MetaspaceAux::dec_used(mdtype(), allocated_chunks_count() * Metachunk::overhead());
2186 }
2187 
2188 void SpaceManager::initialize() {
2189   Metadebug::init_allocation_fail_alot_count();
2190   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2191     _chunks_in_use[i] = NULL;
2192   }
2193   _current_chunk = NULL;
2194   if (TraceMetadataChunkAllocation && Verbose) {
2195     gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
2196   }
2197 }
2198 
2199 void ChunkManager::return_chunks(ChunkIndex index, Metachunk* chunks) {
2200   if (chunks == NULL) {
2201     return;
2202   }
2203   ChunkList* list = free_chunks(index);
2204   assert(list->size() == chunks->word_size(), "Mismatch in chunk sizes");
2205   assert_lock_strong(SpaceManager::expand_lock());
2206   Metachunk* cur = chunks;
2207 
2208   // This returns chunks one at a time.  If a new
2209   // class List can be created that is a base class
2210   // of FreeList then something like FreeList::prepend()
2211   // can be used in place of this loop
2212   while (cur != NULL) {
2213     assert(cur->container() != NULL, "Container should have been set");
2214     cur->container()->dec_container_count();
2215     // Capture the next link before it is changed
2216     // by the call to return_chunk_at_head();
2217     Metachunk* next = cur->next();
2218     DEBUG_ONLY(cur->set_is_tagged_free(true);)
2219     list->return_chunk_at_head(cur);
2220     cur = next;
2221   }
2222 }
2223 
2224 SpaceManager::~SpaceManager() {
2225   // This call this->_lock which can't be done while holding expand_lock()
2226   assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(),
2227     err_msg("sum_capacity_in_chunks_in_use() " SIZE_FORMAT
2228             " allocated_chunks_words() " SIZE_FORMAT,
2229             sum_capacity_in_chunks_in_use(), allocated_chunks_words()));
2230 
2231   MutexLockerEx fcl(SpaceManager::expand_lock(),
2232                     Mutex::_no_safepoint_check_flag);
2233 
2234   chunk_manager()->slow_locked_verify();
2235 
2236   dec_total_from_size_metrics();
2237 
2238   if (TraceMetadataChunkAllocation && Verbose) {
2239     gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
2240     locked_print_chunks_in_use_on(gclog_or_tty);
2241   }
2242 
2243   // Do not mangle freed Metachunks.  The chunk size inside Metachunks
2244   // is during the freeing of a VirtualSpaceNodes.
2245 
2246   // Have to update before the chunks_in_use lists are emptied
2247   // below.
2248   chunk_manager()->inc_free_chunks_total(allocated_chunks_words(),
2249                                          sum_count_in_chunks_in_use());
2250 
2251   // Add all the chunks in use by this space manager
2252   // to the global list of free chunks.
2253 
2254   // Follow each list of chunks-in-use and add them to the
2255   // free lists.  Each list is NULL terminated.
2256 
2257   for (ChunkIndex i = ZeroIndex; i < HumongousIndex; i = next_chunk_index(i)) {
2258     if (TraceMetadataChunkAllocation && Verbose) {
2259       gclog_or_tty->print_cr("returned %d %s chunks to freelist",
2260                              sum_count_in_chunks_in_use(i),
2261                              chunk_size_name(i));
2262     }
2263     Metachunk* chunks = chunks_in_use(i);
2264     chunk_manager()->return_chunks(i, chunks);
2265     set_chunks_in_use(i, NULL);
2266     if (TraceMetadataChunkAllocation && Verbose) {
2267       gclog_or_tty->print_cr("updated freelist count %d %s",
2268                              chunk_manager()->free_chunks(i)->count(),
2269                              chunk_size_name(i));
2270     }
2271     assert(i != HumongousIndex, "Humongous chunks are handled explicitly later");
2272   }
2273 
2274   // The medium chunk case may be optimized by passing the head and
2275   // tail of the medium chunk list to add_at_head().  The tail is often
2276   // the current chunk but there are probably exceptions.
2277 
2278   // Humongous chunks
2279   if (TraceMetadataChunkAllocation && Verbose) {
2280     gclog_or_tty->print_cr("returned %d %s humongous chunks to dictionary",
2281                             sum_count_in_chunks_in_use(HumongousIndex),
2282                             chunk_size_name(HumongousIndex));
2283     gclog_or_tty->print("Humongous chunk dictionary: ");
2284   }
2285   // Humongous chunks are never the current chunk.
2286   Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
2287 
2288   while (humongous_chunks != NULL) {
2289 #ifdef ASSERT
2290     humongous_chunks->set_is_tagged_free(true);
2291 #endif
2292     if (TraceMetadataChunkAllocation && Verbose) {
2293       gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ",
2294                           humongous_chunks,
2295                           humongous_chunks->word_size());
2296     }
2297     assert(humongous_chunks->word_size() == (size_t)
2298            align_size_up(humongous_chunks->word_size(),
2299                              smallest_chunk_size()),
2300            err_msg("Humongous chunk size is wrong: word size " SIZE_FORMAT
2301                    " granularity %d",
2302                    humongous_chunks->word_size(), smallest_chunk_size()));
2303     Metachunk* next_humongous_chunks = humongous_chunks->next();
2304     humongous_chunks->container()->dec_container_count();
2305     chunk_manager()->humongous_dictionary()->return_chunk(humongous_chunks);
2306     humongous_chunks = next_humongous_chunks;
2307   }
2308   if (TraceMetadataChunkAllocation && Verbose) {
2309     gclog_or_tty->cr();
2310     gclog_or_tty->print_cr("updated dictionary count %d %s",
2311                      chunk_manager()->humongous_dictionary()->total_count(),
2312                      chunk_size_name(HumongousIndex));
2313   }
2314   chunk_manager()->slow_locked_verify();
2315 }
2316 
2317 const char* SpaceManager::chunk_size_name(ChunkIndex index) const {
2318   switch (index) {
2319     case SpecializedIndex:
2320       return "Specialized";
2321     case SmallIndex:
2322       return "Small";
2323     case MediumIndex:
2324       return "Medium";
2325     case HumongousIndex:
2326       return "Humongous";
2327     default:
2328       return NULL;
2329   }
2330 }
2331 
2332 ChunkIndex ChunkManager::list_index(size_t size) {
2333   switch (size) {
2334     case SpecializedChunk:
2335       assert(SpecializedChunk == ClassSpecializedChunk,
2336              "Need branch for ClassSpecializedChunk");
2337       return SpecializedIndex;
2338     case SmallChunk:
2339     case ClassSmallChunk:
2340       return SmallIndex;
2341     case MediumChunk:
2342     case ClassMediumChunk:
2343       return MediumIndex;
2344     default:
2345       assert(size > MediumChunk || size > ClassMediumChunk,
2346              "Not a humongous chunk");
2347       return HumongousIndex;
2348   }
2349 }
2350 
2351 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
2352   assert_lock_strong(_lock);
2353   size_t raw_word_size = get_raw_word_size(word_size);
2354   size_t min_size = TreeChunk<Metablock, FreeList<Metablock> >::min_size();
2355   assert(raw_word_size >= min_size,
2356          err_msg("Should not deallocate dark matter " SIZE_FORMAT "<" SIZE_FORMAT, word_size, min_size));
2357   block_freelists()->return_block(p, raw_word_size);
2358 }
2359 
2360 // Adds a chunk to the list of chunks in use.
2361 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
2362 
2363   assert(new_chunk != NULL, "Should not be NULL");
2364   assert(new_chunk->next() == NULL, "Should not be on a list");
2365 
2366   new_chunk->reset_empty();
2367 
2368   // Find the correct list and and set the current
2369   // chunk for that list.
2370   ChunkIndex index = ChunkManager::list_index(new_chunk->word_size());
2371 
2372   if (index != HumongousIndex) {
2373     retire_current_chunk();
2374     set_current_chunk(new_chunk);
2375     new_chunk->set_next(chunks_in_use(index));
2376     set_chunks_in_use(index, new_chunk);
2377   } else {
2378     // For null class loader data and DumpSharedSpaces, the first chunk isn't
2379     // small, so small will be null.  Link this first chunk as the current
2380     // chunk.
2381     if (make_current) {
2382       // Set as the current chunk but otherwise treat as a humongous chunk.
2383       set_current_chunk(new_chunk);
2384     }
2385     // Link at head.  The _current_chunk only points to a humongous chunk for
2386     // the null class loader metaspace (class and data virtual space managers)
2387     // any humongous chunks so will not point to the tail
2388     // of the humongous chunks list.
2389     new_chunk->set_next(chunks_in_use(HumongousIndex));
2390     set_chunks_in_use(HumongousIndex, new_chunk);
2391 
2392     assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
2393   }
2394 
2395   // Add to the running sum of capacity
2396   inc_size_metrics(new_chunk->word_size());
2397 
2398   assert(new_chunk->is_empty(), "Not ready for reuse");
2399   if (TraceMetadataChunkAllocation && Verbose) {
2400     gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
2401                         sum_count_in_chunks_in_use());
2402     new_chunk->print_on(gclog_or_tty);
2403     chunk_manager()->locked_print_free_chunks(gclog_or_tty);
2404   }
2405 }
2406 
2407 void SpaceManager::retire_current_chunk() {
2408   if (current_chunk() != NULL) {
2409     size_t remaining_words = current_chunk()->free_word_size();
2410     if (remaining_words >= TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
2411       block_freelists()->return_block(current_chunk()->allocate(remaining_words), remaining_words);
2412       inc_used_metrics(remaining_words);
2413     }
2414   }
2415 }
2416 
2417 Metachunk* SpaceManager::get_new_chunk(size_t word_size,
2418                                        size_t grow_chunks_by_words) {
2419   // Get a chunk from the chunk freelist
2420   Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
2421 
2422   if (next == NULL) {
2423     next = vs_list()->get_new_chunk(word_size,
2424                                     grow_chunks_by_words,
2425                                     medium_chunk_bunch());
2426   }
2427 
2428   if (TraceMetadataHumongousAllocation && next != NULL &&
2429       SpaceManager::is_humongous(next->word_size())) {
2430     gclog_or_tty->print_cr("  new humongous chunk word size "
2431                            PTR_FORMAT, next->word_size());
2432   }
2433 
2434   return next;
2435 }
2436 
2437 MetaWord* SpaceManager::allocate(size_t word_size) {
2438   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2439 
2440   size_t raw_word_size = get_raw_word_size(word_size);
2441   BlockFreelist* fl =  block_freelists();
2442   MetaWord* p = NULL;
2443   // Allocation from the dictionary is expensive in the sense that
2444   // the dictionary has to be searched for a size.  Don't allocate
2445   // from the dictionary until it starts to get fat.  Is this
2446   // a reasonable policy?  Maybe an skinny dictionary is fast enough
2447   // for allocations.  Do some profiling.  JJJ
2448   if (fl->total_size() > allocation_from_dictionary_limit) {
2449     p = fl->get_block(raw_word_size);
2450   }
2451   if (p == NULL) {
2452     p = allocate_work(raw_word_size);
2453   }
2454 
2455   return p;
2456 }
2457 
2458 // Returns the address of spaced allocated for "word_size".
2459 // This methods does not know about blocks (Metablocks)
2460 MetaWord* SpaceManager::allocate_work(size_t word_size) {
2461   assert_lock_strong(_lock);
2462 #ifdef ASSERT
2463   if (Metadebug::test_metadata_failure()) {
2464     return NULL;
2465   }
2466 #endif
2467   // Is there space in the current chunk?
2468   MetaWord* result = NULL;
2469 
2470   // For DumpSharedSpaces, only allocate out of the current chunk which is
2471   // never null because we gave it the size we wanted.   Caller reports out
2472   // of memory if this returns null.
2473   if (DumpSharedSpaces) {
2474     assert(current_chunk() != NULL, "should never happen");
2475     inc_used_metrics(word_size);
2476     return current_chunk()->allocate(word_size); // caller handles null result
2477   }
2478 
2479   if (current_chunk() != NULL) {
2480     result = current_chunk()->allocate(word_size);
2481   }
2482 
2483   if (result == NULL) {
2484     result = grow_and_allocate(word_size);
2485   }
2486 
2487   if (result != NULL) {
2488     inc_used_metrics(word_size);
2489     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
2490            "Head of the list is being allocated");
2491   }
2492 
2493   return result;
2494 }
2495 
2496 void SpaceManager::verify() {
2497   // If there are blocks in the dictionary, then
2498   // verification of chunks does not work since
2499   // being in the dictionary alters a chunk.
2500   if (block_freelists()->total_size() == 0) {
2501     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2502       Metachunk* curr = chunks_in_use(i);
2503       while (curr != NULL) {
2504         curr->verify();
2505         verify_chunk_size(curr);
2506         curr = curr->next();
2507       }
2508     }
2509   }
2510 }
2511 
2512 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
2513   assert(is_humongous(chunk->word_size()) ||
2514          chunk->word_size() == medium_chunk_size() ||
2515          chunk->word_size() == small_chunk_size() ||
2516          chunk->word_size() == specialized_chunk_size(),
2517          "Chunk size is wrong");
2518   return;
2519 }
2520 
2521 #ifdef ASSERT
2522 void SpaceManager::verify_allocated_blocks_words() {
2523   // Verification is only guaranteed at a safepoint.
2524   assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(),
2525     "Verification can fail if the applications is running");
2526   assert(allocated_blocks_words() == sum_used_in_chunks_in_use(),
2527     err_msg("allocation total is not consistent " SIZE_FORMAT
2528             " vs " SIZE_FORMAT,
2529             allocated_blocks_words(), sum_used_in_chunks_in_use()));
2530 }
2531 
2532 #endif
2533 
2534 void SpaceManager::dump(outputStream* const out) const {
2535   size_t curr_total = 0;
2536   size_t waste = 0;
2537   uint i = 0;
2538   size_t used = 0;
2539   size_t capacity = 0;
2540 
2541   // Add up statistics for all chunks in this SpaceManager.
2542   for (ChunkIndex index = ZeroIndex;
2543        index < NumberOfInUseLists;
2544        index = next_chunk_index(index)) {
2545     for (Metachunk* curr = chunks_in_use(index);
2546          curr != NULL;
2547          curr = curr->next()) {
2548       out->print("%d) ", i++);
2549       curr->print_on(out);
2550       curr_total += curr->word_size();
2551       used += curr->used_word_size();
2552       capacity += curr->word_size();
2553       waste += curr->free_word_size() + curr->overhead();;
2554     }
2555   }
2556 
2557   if (TraceMetadataChunkAllocation && Verbose) {
2558     block_freelists()->print_on(out);
2559   }
2560 
2561   size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size();
2562   // Free space isn't wasted.
2563   waste -= free;
2564 
2565   out->print_cr("total of all chunks "  SIZE_FORMAT " used " SIZE_FORMAT
2566                 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
2567                 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
2568 }
2569 
2570 #ifndef PRODUCT
2571 void SpaceManager::mangle_freed_chunks() {
2572   for (ChunkIndex index = ZeroIndex;
2573        index < NumberOfInUseLists;
2574        index = next_chunk_index(index)) {
2575     for (Metachunk* curr = chunks_in_use(index);
2576          curr != NULL;
2577          curr = curr->next()) {
2578       curr->mangle();
2579     }
2580   }
2581 }
2582 #endif // PRODUCT
2583 
2584 // MetaspaceAux
2585 
2586 
2587 size_t MetaspaceAux::_capacity_words[] = {0, 0};
2588 size_t MetaspaceAux::_used_words[] = {0, 0};
2589 
2590 size_t MetaspaceAux::free_bytes(Metaspace::MetadataType mdtype) {
2591   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2592   return list == NULL ? 0 : list->free_bytes();
2593 }
2594 
2595 size_t MetaspaceAux::free_bytes() {
2596   return free_bytes(Metaspace::ClassType) + free_bytes(Metaspace::NonClassType);
2597 }
2598 
2599 void MetaspaceAux::dec_capacity(Metaspace::MetadataType mdtype, size_t words) {
2600   assert_lock_strong(SpaceManager::expand_lock());
2601   assert(words <= capacity_words(mdtype),
2602     err_msg("About to decrement below 0: words " SIZE_FORMAT
2603             " is greater than _capacity_words[%u] " SIZE_FORMAT,
2604             words, mdtype, capacity_words(mdtype)));
2605   _capacity_words[mdtype] -= words;
2606 }
2607 
2608 void MetaspaceAux::inc_capacity(Metaspace::MetadataType mdtype, size_t words) {
2609   assert_lock_strong(SpaceManager::expand_lock());
2610   // Needs to be atomic
2611   _capacity_words[mdtype] += words;
2612 }
2613 
2614 void MetaspaceAux::dec_used(Metaspace::MetadataType mdtype, size_t words) {
2615   assert(words <= used_words(mdtype),
2616     err_msg("About to decrement below 0: words " SIZE_FORMAT
2617             " is greater than _used_words[%u] " SIZE_FORMAT,
2618             words, mdtype, used_words(mdtype)));
2619   // For CMS deallocation of the Metaspaces occurs during the
2620   // sweep which is a concurrent phase.  Protection by the expand_lock()
2621   // is not enough since allocation is on a per Metaspace basis
2622   // and protected by the Metaspace lock.
2623   jlong minus_words = (jlong) - (jlong) words;
2624   Atomic::add_ptr(minus_words, &_used_words[mdtype]);
2625 }
2626 
2627 void MetaspaceAux::inc_used(Metaspace::MetadataType mdtype, size_t words) {
2628   // _used_words tracks allocations for
2629   // each piece of metadata.  Those allocations are
2630   // generally done concurrently by different application
2631   // threads so must be done atomically.
2632   Atomic::add_ptr(words, &_used_words[mdtype]);
2633 }
2634 
2635 size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) {
2636   size_t used = 0;
2637   ClassLoaderDataGraphMetaspaceIterator iter;
2638   while (iter.repeat()) {
2639     Metaspace* msp = iter.get_next();
2640     // Sum allocated_blocks_words for each metaspace
2641     if (msp != NULL) {
2642       used += msp->used_words_slow(mdtype);
2643     }
2644   }
2645   return used * BytesPerWord;
2646 }
2647 
2648 size_t MetaspaceAux::free_bytes_slow(Metaspace::MetadataType mdtype) {
2649   size_t free = 0;
2650   ClassLoaderDataGraphMetaspaceIterator iter;
2651   while (iter.repeat()) {
2652     Metaspace* msp = iter.get_next();
2653     if (msp != NULL) {
2654       free += msp->free_words_slow(mdtype);
2655     }
2656   }
2657   return free * BytesPerWord;
2658 }
2659 
2660 size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) {
2661   if ((mdtype == Metaspace::ClassType) && !Metaspace::using_class_space()) {
2662     return 0;
2663   }
2664   // Don't count the space in the freelists.  That space will be
2665   // added to the capacity calculation as needed.
2666   size_t capacity = 0;
2667   ClassLoaderDataGraphMetaspaceIterator iter;
2668   while (iter.repeat()) {
2669     Metaspace* msp = iter.get_next();
2670     if (msp != NULL) {
2671       capacity += msp->capacity_words_slow(mdtype);
2672     }
2673   }
2674   return capacity * BytesPerWord;
2675 }
2676 
2677 size_t MetaspaceAux::capacity_bytes_slow() {
2678 #ifdef PRODUCT
2679   // Use capacity_bytes() in PRODUCT instead of this function.
2680   guarantee(false, "Should not call capacity_bytes_slow() in the PRODUCT");
2681 #endif
2682   size_t class_capacity = capacity_bytes_slow(Metaspace::ClassType);
2683   size_t non_class_capacity = capacity_bytes_slow(Metaspace::NonClassType);
2684   assert(capacity_bytes() == class_capacity + non_class_capacity,
2685       err_msg("bad accounting: capacity_bytes() " SIZE_FORMAT
2686         " class_capacity + non_class_capacity " SIZE_FORMAT
2687         " class_capacity " SIZE_FORMAT " non_class_capacity " SIZE_FORMAT,
2688         capacity_bytes(), class_capacity + non_class_capacity,
2689         class_capacity, non_class_capacity));
2690 
2691   return class_capacity + non_class_capacity;
2692 }
2693 
2694 size_t MetaspaceAux::reserved_bytes(Metaspace::MetadataType mdtype) {
2695   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2696   return list == NULL ? 0 : list->reserved_bytes();
2697 }
2698 
2699 size_t MetaspaceAux::committed_bytes(Metaspace::MetadataType mdtype) {
2700   VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
2701   return list == NULL ? 0 : list->committed_bytes();
2702 }
2703 
2704 size_t MetaspaceAux::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); }
2705 
2706 size_t MetaspaceAux::free_chunks_total_words(Metaspace::MetadataType mdtype) {
2707   ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype);
2708   if (chunk_manager == NULL) {
2709     return 0;
2710   }
2711   chunk_manager->slow_verify();
2712   return chunk_manager->free_chunks_total_words();
2713 }
2714 
2715 size_t MetaspaceAux::free_chunks_total_bytes(Metaspace::MetadataType mdtype) {
2716   return free_chunks_total_words(mdtype) * BytesPerWord;
2717 }
2718 
2719 size_t MetaspaceAux::free_chunks_total_words() {
2720   return free_chunks_total_words(Metaspace::ClassType) +
2721          free_chunks_total_words(Metaspace::NonClassType);
2722 }
2723 
2724 size_t MetaspaceAux::free_chunks_total_bytes() {
2725   return free_chunks_total_words() * BytesPerWord;
2726 }
2727 
2728 bool MetaspaceAux::has_chunk_free_list(Metaspace::MetadataType mdtype) {
2729   return Metaspace::get_chunk_manager(mdtype) != NULL;
2730 }
2731 
2732 MetaspaceChunkFreeListSummary MetaspaceAux::chunk_free_list_summary(Metaspace::MetadataType mdtype) {
2733   if (!has_chunk_free_list(mdtype)) {
2734     return MetaspaceChunkFreeListSummary();
2735   }
2736 
2737   const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype);
2738   return cm->chunk_free_list_summary();
2739 }
2740 
2741 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
2742   gclog_or_tty->print(", [Metaspace:");
2743   if (PrintGCDetails && Verbose) {
2744     gclog_or_tty->print(" "  SIZE_FORMAT
2745                         "->" SIZE_FORMAT
2746                         "("  SIZE_FORMAT ")",
2747                         prev_metadata_used,
2748                         used_bytes(),
2749                         reserved_bytes());
2750   } else {
2751     gclog_or_tty->print(" "  SIZE_FORMAT "K"
2752                         "->" SIZE_FORMAT "K"
2753                         "("  SIZE_FORMAT "K)",
2754                         prev_metadata_used/K,
2755                         used_bytes()/K,
2756                         reserved_bytes()/K);
2757   }
2758 
2759   gclog_or_tty->print("]");
2760 }
2761 
2762 // This is printed when PrintGCDetails
2763 void MetaspaceAux::print_on(outputStream* out) {
2764   Metaspace::MetadataType nct = Metaspace::NonClassType;
2765 
2766   out->print_cr(" Metaspace       "
2767                 "used "      SIZE_FORMAT "K, "
2768                 "capacity "  SIZE_FORMAT "K, "
2769                 "committed " SIZE_FORMAT "K, "
2770                 "reserved "  SIZE_FORMAT "K",
2771                 used_bytes()/K,
2772                 capacity_bytes()/K,
2773                 committed_bytes()/K,
2774                 reserved_bytes()/K);
2775 
2776   if (Metaspace::using_class_space()) {
2777     Metaspace::MetadataType ct = Metaspace::ClassType;
2778     out->print_cr("  class space    "
2779                   "used "      SIZE_FORMAT "K, "
2780                   "capacity "  SIZE_FORMAT "K, "
2781                   "committed " SIZE_FORMAT "K, "
2782                   "reserved "  SIZE_FORMAT "K",
2783                   used_bytes(ct)/K,
2784                   capacity_bytes(ct)/K,
2785                   committed_bytes(ct)/K,
2786                   reserved_bytes(ct)/K);
2787   }
2788 }
2789 
2790 // Print information for class space and data space separately.
2791 // This is almost the same as above.
2792 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
2793   size_t free_chunks_capacity_bytes = free_chunks_total_bytes(mdtype);
2794   size_t capacity_bytes = capacity_bytes_slow(mdtype);
2795   size_t used_bytes = used_bytes_slow(mdtype);
2796   size_t free_bytes = free_bytes_slow(mdtype);
2797   size_t used_and_free = used_bytes + free_bytes +
2798                            free_chunks_capacity_bytes;
2799   out->print_cr("  Chunk accounting: used in chunks " SIZE_FORMAT
2800              "K + unused in chunks " SIZE_FORMAT "K  + "
2801              " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
2802              "K  capacity in allocated chunks " SIZE_FORMAT "K",
2803              used_bytes / K,
2804              free_bytes / K,
2805              free_chunks_capacity_bytes / K,
2806              used_and_free / K,
2807              capacity_bytes / K);
2808   // Accounting can only be correct if we got the values during a safepoint
2809   assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong");
2810 }
2811 
2812 // Print total fragmentation for class metaspaces
2813 void MetaspaceAux::print_class_waste(outputStream* out) {
2814   assert(Metaspace::using_class_space(), "class metaspace not used");
2815   size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0;
2816   size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_humongous_count = 0;
2817   ClassLoaderDataGraphMetaspaceIterator iter;
2818   while (iter.repeat()) {
2819     Metaspace* msp = iter.get_next();
2820     if (msp != NULL) {
2821       cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2822       cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2823       cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2824       cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
2825       cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2826       cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
2827       cls_humongous_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2828     }
2829   }
2830   out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2831                 SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2832                 SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2833                 "large count " SIZE_FORMAT,
2834                 cls_specialized_count, cls_specialized_waste,
2835                 cls_small_count, cls_small_waste,
2836                 cls_medium_count, cls_medium_waste, cls_humongous_count);
2837 }
2838 
2839 // Print total fragmentation for data and class metaspaces separately
2840 void MetaspaceAux::print_waste(outputStream* out) {
2841   size_t specialized_waste = 0, small_waste = 0, medium_waste = 0;
2842   size_t specialized_count = 0, small_count = 0, medium_count = 0, humongous_count = 0;
2843 
2844   ClassLoaderDataGraphMetaspaceIterator iter;
2845   while (iter.repeat()) {
2846     Metaspace* msp = iter.get_next();
2847     if (msp != NULL) {
2848       specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
2849       specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
2850       small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2851       small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
2852       medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2853       medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
2854       humongous_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
2855     }
2856   }
2857   out->print_cr("Total fragmentation waste (words) doesn't count free space");
2858   out->print_cr("  data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
2859                         SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
2860                         SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
2861                         "large count " SIZE_FORMAT,
2862              specialized_count, specialized_waste, small_count,
2863              small_waste, medium_count, medium_waste, humongous_count);
2864   if (Metaspace::using_class_space()) {
2865     print_class_waste(out);
2866   }
2867 }
2868 
2869 // Dump global metaspace things from the end of ClassLoaderDataGraph
2870 void MetaspaceAux::dump(outputStream* out) {
2871   out->print_cr("All Metaspace:");
2872   out->print("data space: "); print_on(out, Metaspace::NonClassType);
2873   out->print("class space: "); print_on(out, Metaspace::ClassType);
2874   print_waste(out);
2875 }
2876 
2877 void MetaspaceAux::verify_free_chunks() {
2878   Metaspace::chunk_manager_metadata()->verify();
2879   if (Metaspace::using_class_space()) {
2880     Metaspace::chunk_manager_class()->verify();
2881   }
2882 }
2883 
2884 void MetaspaceAux::verify_capacity() {
2885 #ifdef ASSERT
2886   size_t running_sum_capacity_bytes = capacity_bytes();
2887   // For purposes of the running sum of capacity, verify against capacity
2888   size_t capacity_in_use_bytes = capacity_bytes_slow();
2889   assert(running_sum_capacity_bytes == capacity_in_use_bytes,
2890     err_msg("capacity_words() * BytesPerWord " SIZE_FORMAT
2891             " capacity_bytes_slow()" SIZE_FORMAT,
2892             running_sum_capacity_bytes, capacity_in_use_bytes));
2893   for (Metaspace::MetadataType i = Metaspace::ClassType;
2894        i < Metaspace:: MetadataTypeCount;
2895        i = (Metaspace::MetadataType)(i + 1)) {
2896     size_t capacity_in_use_bytes = capacity_bytes_slow(i);
2897     assert(capacity_bytes(i) == capacity_in_use_bytes,
2898       err_msg("capacity_bytes(%u) " SIZE_FORMAT
2899               " capacity_bytes_slow(%u)" SIZE_FORMAT,
2900               i, capacity_bytes(i), i, capacity_in_use_bytes));
2901   }
2902 #endif
2903 }
2904 
2905 void MetaspaceAux::verify_used() {
2906 #ifdef ASSERT
2907   size_t running_sum_used_bytes = used_bytes();
2908   // For purposes of the running sum of used, verify against used
2909   size_t used_in_use_bytes = used_bytes_slow();
2910   assert(used_bytes() == used_in_use_bytes,
2911     err_msg("used_bytes() " SIZE_FORMAT
2912             " used_bytes_slow()" SIZE_FORMAT,
2913             used_bytes(), used_in_use_bytes));
2914   for (Metaspace::MetadataType i = Metaspace::ClassType;
2915        i < Metaspace:: MetadataTypeCount;
2916        i = (Metaspace::MetadataType)(i + 1)) {
2917     size_t used_in_use_bytes = used_bytes_slow(i);
2918     assert(used_bytes(i) == used_in_use_bytes,
2919       err_msg("used_bytes(%u) " SIZE_FORMAT
2920               " used_bytes_slow(%u)" SIZE_FORMAT,
2921               i, used_bytes(i), i, used_in_use_bytes));
2922   }
2923 #endif
2924 }
2925 
2926 void MetaspaceAux::verify_metrics() {
2927   verify_capacity();
2928   verify_used();
2929 }
2930 
2931 
2932 // Metaspace methods
2933 
2934 size_t Metaspace::_first_chunk_word_size = 0;
2935 size_t Metaspace::_first_class_chunk_word_size = 0;
2936 
2937 size_t Metaspace::_commit_alignment = 0;
2938 size_t Metaspace::_reserve_alignment = 0;
2939 
2940 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
2941   initialize(lock, type);
2942 }
2943 
2944 Metaspace::~Metaspace() {
2945   delete _vsm;
2946   if (using_class_space()) {
2947     delete _class_vsm;
2948   }
2949 }
2950 
2951 VirtualSpaceList* Metaspace::_space_list = NULL;
2952 VirtualSpaceList* Metaspace::_class_space_list = NULL;
2953 
2954 ChunkManager* Metaspace::_chunk_manager_metadata = NULL;
2955 ChunkManager* Metaspace::_chunk_manager_class = NULL;
2956 
2957 #define VIRTUALSPACEMULTIPLIER 2
2958 
2959 #ifdef _LP64
2960 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
2961 
2962 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) {
2963   // Figure out the narrow_klass_base and the narrow_klass_shift.  The
2964   // narrow_klass_base is the lower of the metaspace base and the cds base
2965   // (if cds is enabled).  The narrow_klass_shift depends on the distance
2966   // between the lower base and higher address.
2967   address lower_base;
2968   address higher_address;
2969 #if INCLUDE_CDS
2970   if (UseSharedSpaces) {
2971     higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
2972                           (address)(metaspace_base + compressed_class_space_size()));
2973     lower_base = MIN2(metaspace_base, cds_base);
2974   } else
2975 #endif
2976   {
2977     higher_address = metaspace_base + compressed_class_space_size();
2978     lower_base = metaspace_base;
2979 
2980     uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes;
2981     // If compressed class space fits in lower 32G, we don't need a base.
2982     if (higher_address <= (address)klass_encoding_max) {
2983       lower_base = 0; // Effectively lower base is zero.
2984     }
2985   }
2986 
2987   Universe::set_narrow_klass_base(lower_base);
2988 
2989   if ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) {
2990     Universe::set_narrow_klass_shift(0);
2991   } else {
2992     assert(!UseSharedSpaces, "Cannot shift with UseSharedSpaces");
2993     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
2994   }
2995 }
2996 
2997 #if INCLUDE_CDS
2998 // Return TRUE if the specified metaspace_base and cds_base are close enough
2999 // to work with compressed klass pointers.
3000 bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) {
3001   assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS");
3002   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3003   address lower_base = MIN2((address)metaspace_base, cds_base);
3004   address higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
3005                                 (address)(metaspace_base + compressed_class_space_size()));
3006   return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
3007 }
3008 #endif
3009 
3010 // Try to allocate the metaspace at the requested addr.
3011 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
3012   assert(using_class_space(), "called improperly");
3013   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
3014   assert(compressed_class_space_size() < KlassEncodingMetaspaceMax,
3015          "Metaspace size is too big");
3016   assert_is_ptr_aligned(requested_addr, _reserve_alignment);
3017   assert_is_ptr_aligned(cds_base, _reserve_alignment);
3018   assert_is_size_aligned(compressed_class_space_size(), _reserve_alignment);
3019 
3020   // Don't use large pages for the class space.
3021   bool large_pages = false;
3022 
3023   ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(),
3024                                              _reserve_alignment,
3025                                              large_pages,
3026                                              requested_addr);
3027   if (!metaspace_rs.is_reserved()) {
3028 #if INCLUDE_CDS
3029     if (UseSharedSpaces) {
3030       size_t increment = align_size_up(1*G, _reserve_alignment);
3031 
3032       // Keep trying to allocate the metaspace, increasing the requested_addr
3033       // by 1GB each time, until we reach an address that will no longer allow
3034       // use of CDS with compressed klass pointers.
3035       char *addr = requested_addr;
3036       while (!metaspace_rs.is_reserved() && (addr + increment > addr) &&
3037              can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
3038         addr = addr + increment;
3039         metaspace_rs = ReservedSpace(compressed_class_space_size(),
3040                                      _reserve_alignment, large_pages, addr);
3041       }
3042     }
3043 #endif
3044     // If no successful allocation then try to allocate the space anywhere.  If
3045     // that fails then OOM doom.  At this point we cannot try allocating the
3046     // metaspace as if UseCompressedClassPointers is off because too much
3047     // initialization has happened that depends on UseCompressedClassPointers.
3048     // So, UseCompressedClassPointers cannot be turned off at this point.
3049     if (!metaspace_rs.is_reserved()) {
3050       metaspace_rs = ReservedSpace(compressed_class_space_size(),
3051                                    _reserve_alignment, large_pages);
3052       if (!metaspace_rs.is_reserved()) {
3053         vm_exit_during_initialization(err_msg("Could not allocate metaspace: %d bytes",
3054                                               compressed_class_space_size()));
3055       }
3056     }
3057   }
3058 
3059   // If we got here then the metaspace got allocated.
3060   MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass);
3061 
3062 #if INCLUDE_CDS
3063   // Verify that we can use shared spaces.  Otherwise, turn off CDS.
3064   if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) {
3065     FileMapInfo::stop_sharing_and_unmap(
3066         "Could not allocate metaspace at a compatible address");
3067   }
3068 #endif
3069   set_narrow_klass_base_and_shift((address)metaspace_rs.base(),
3070                                   UseSharedSpaces ? (address)cds_base : 0);
3071 
3072   initialize_class_space(metaspace_rs);
3073 
3074   if (PrintCompressedOopsMode || (PrintMiscellaneous && Verbose)) {
3075     gclog_or_tty->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: " SIZE_FORMAT,
3076                             Universe::narrow_klass_base(), Universe::narrow_klass_shift());
3077     gclog_or_tty->print_cr("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT " Req Addr: " PTR_FORMAT,
3078                            compressed_class_space_size(), metaspace_rs.base(), requested_addr);
3079   }
3080 }
3081 
3082 // For UseCompressedClassPointers the class space is reserved above the top of
3083 // the Java heap.  The argument passed in is at the base of the compressed space.
3084 void Metaspace::initialize_class_space(ReservedSpace rs) {
3085   // The reserved space size may be bigger because of alignment, esp with UseLargePages
3086   assert(rs.size() >= CompressedClassSpaceSize,
3087          err_msg(SIZE_FORMAT " != " UINTX_FORMAT, rs.size(), CompressedClassSpaceSize));
3088   assert(using_class_space(), "Must be using class space");
3089   _class_space_list = new VirtualSpaceList(rs);
3090   _chunk_manager_class = new ChunkManager(SpecializedChunk, ClassSmallChunk, ClassMediumChunk);
3091 
3092   if (!_class_space_list->initialization_succeeded()) {
3093     vm_exit_during_initialization("Failed to setup compressed class space virtual space list.");
3094   }
3095 }
3096 
3097 #endif
3098 
3099 void Metaspace::ergo_initialize() {
3100   if (DumpSharedSpaces) {
3101     // Using large pages when dumping the shared archive is currently not implemented.
3102     FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false);
3103   }
3104 
3105   size_t page_size = os::vm_page_size();
3106   if (UseLargePages && UseLargePagesInMetaspace) {
3107     page_size = os::large_page_size();
3108   }
3109 
3110   _commit_alignment  = page_size;
3111   _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
3112 
3113   // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
3114   // override if MaxMetaspaceSize was set on the command line or not.
3115   // This information is needed later to conform to the specification of the
3116   // java.lang.management.MemoryUsage API.
3117   //
3118   // Ideally, we would be able to set the default value of MaxMetaspaceSize in
3119   // globals.hpp to the aligned value, but this is not possible, since the
3120   // alignment depends on other flags being parsed.
3121   MaxMetaspaceSize = align_size_down_bounded(MaxMetaspaceSize, _reserve_alignment);
3122 
3123   if (MetaspaceSize > MaxMetaspaceSize) {
3124     MetaspaceSize = MaxMetaspaceSize;
3125   }
3126 
3127   MetaspaceSize = align_size_down_bounded(MetaspaceSize, _commit_alignment);
3128 
3129   assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
3130 
3131   if (MetaspaceSize < 256*K) {
3132     vm_exit_during_initialization("Too small initial Metaspace size");
3133   }
3134 
3135   MinMetaspaceExpansion = align_size_down_bounded(MinMetaspaceExpansion, _commit_alignment);
3136   MaxMetaspaceExpansion = align_size_down_bounded(MaxMetaspaceExpansion, _commit_alignment);
3137 
3138   CompressedClassSpaceSize = align_size_down_bounded(CompressedClassSpaceSize, _reserve_alignment);
3139   set_compressed_class_space_size(CompressedClassSpaceSize);
3140 }
3141 
3142 void Metaspace::global_initialize() {
3143   MetaspaceGC::initialize();
3144 
3145   // Initialize the alignment for shared spaces.
3146   int max_alignment = os::vm_allocation_granularity();
3147   size_t cds_total = 0;
3148 
3149   MetaspaceShared::set_max_alignment(max_alignment);
3150 
3151   if (DumpSharedSpaces) {
3152 #if INCLUDE_CDS
3153     MetaspaceShared::estimate_regions_size();
3154 
3155     SharedReadOnlySize  = align_size_up(SharedReadOnlySize,  max_alignment);
3156     SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
3157     SharedMiscDataSize  = align_size_up(SharedMiscDataSize,  max_alignment);
3158     SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize,  max_alignment);
3159 
3160     // the min_misc_code_size estimate is based on MetaspaceShared::generate_vtable_methods()
3161     uintx min_misc_code_size = align_size_up(
3162       (MetaspaceShared::num_virtuals * MetaspaceShared::vtbl_list_size) *
3163         (sizeof(void*) + MetaspaceShared::vtbl_method_size) + MetaspaceShared::vtbl_common_code_size,
3164           max_alignment);
3165 
3166     if (SharedMiscCodeSize < min_misc_code_size) {
3167       report_out_of_shared_space(SharedMiscCode);
3168     }
3169 
3170     // Initialize with the sum of the shared space sizes.  The read-only
3171     // and read write metaspace chunks will be allocated out of this and the
3172     // remainder is the misc code and data chunks.
3173     cds_total = FileMapInfo::shared_spaces_size();
3174     cds_total = align_size_up(cds_total, _reserve_alignment);
3175     _space_list = new VirtualSpaceList(cds_total/wordSize);
3176     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3177 
3178     if (!_space_list->initialization_succeeded()) {
3179       vm_exit_during_initialization("Unable to dump shared archive.", NULL);
3180     }
3181 
3182 #ifdef _LP64
3183     if (cds_total + compressed_class_space_size() > UnscaledClassSpaceMax) {
3184       vm_exit_during_initialization("Unable to dump shared archive.",
3185           err_msg("Size of archive (" SIZE_FORMAT ") + compressed class space ("
3186                   SIZE_FORMAT ") == total (" SIZE_FORMAT ") is larger than compressed "
3187                   "klass limit: " SIZE_FORMAT, cds_total, compressed_class_space_size(),
3188                   cds_total + compressed_class_space_size(), UnscaledClassSpaceMax));
3189     }
3190 
3191     // Set the compressed klass pointer base so that decoding of these pointers works
3192     // properly when creating the shared archive.
3193     assert(UseCompressedOops && UseCompressedClassPointers,
3194       "UseCompressedOops and UseCompressedClassPointers must be set");
3195     Universe::set_narrow_klass_base((address)_space_list->current_virtual_space()->bottom());
3196     if (TraceMetavirtualspaceAllocation && Verbose) {
3197       gclog_or_tty->print_cr("Setting_narrow_klass_base to Address: " PTR_FORMAT,
3198                              _space_list->current_virtual_space()->bottom());
3199     }
3200 
3201     Universe::set_narrow_klass_shift(0);
3202 #endif // _LP64
3203 #endif // INCLUDE_CDS
3204   } else {
3205 #if INCLUDE_CDS
3206     // If using shared space, open the file that contains the shared space
3207     // and map in the memory before initializing the rest of metaspace (so
3208     // the addresses don't conflict)
3209     address cds_address = NULL;
3210     if (UseSharedSpaces) {
3211       FileMapInfo* mapinfo = new FileMapInfo();
3212 
3213       // Open the shared archive file, read and validate the header. If
3214       // initialization fails, shared spaces [UseSharedSpaces] are
3215       // disabled and the file is closed.
3216       // Map in spaces now also
3217       if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
3218         cds_total = FileMapInfo::shared_spaces_size();
3219         cds_address = (address)mapinfo->region_base(0);
3220       } else {
3221         assert(!mapinfo->is_open() && !UseSharedSpaces,
3222                "archive file not closed or shared spaces not disabled.");
3223       }
3224     }
3225 #endif // INCLUDE_CDS
3226 #ifdef _LP64
3227     // If UseCompressedClassPointers is set then allocate the metaspace area
3228     // above the heap and above the CDS area (if it exists).
3229     if (using_class_space()) {
3230       if (UseSharedSpaces) {
3231 #if INCLUDE_CDS
3232         char* cds_end = (char*)(cds_address + cds_total);
3233         cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
3234         allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
3235 #endif
3236       } else {
3237         char* base = (char*)align_ptr_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
3238         allocate_metaspace_compressed_klass_ptrs(base, 0);
3239       }
3240     }
3241 #endif // _LP64
3242 
3243     // Initialize these before initializing the VirtualSpaceList
3244     _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
3245     _first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
3246     // Make the first class chunk bigger than a medium chunk so it's not put
3247     // on the medium chunk list.   The next chunk will be small and progress
3248     // from there.  This size calculated by -version.
3249     _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
3250                                        (CompressedClassSpaceSize/BytesPerWord)*2);
3251     _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
3252     // Arbitrarily set the initial virtual space to a multiple
3253     // of the boot class loader size.
3254     size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size;
3255     word_size = align_size_up(word_size, Metaspace::reserve_alignment_words());
3256 
3257     // Initialize the list of virtual spaces.
3258     _space_list = new VirtualSpaceList(word_size);
3259     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
3260 
3261     if (!_space_list->initialization_succeeded()) {
3262       vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL);
3263     }
3264   }
3265 
3266   _tracer = new MetaspaceTracer();
3267 }
3268 
3269 void Metaspace::post_initialize() {
3270   MetaspaceGC::post_initialize();
3271 }
3272 
3273 Metachunk* Metaspace::get_initialization_chunk(MetadataType mdtype,
3274                                                size_t chunk_word_size,
3275                                                size_t chunk_bunch) {
3276   // Get a chunk from the chunk freelist
3277   Metachunk* chunk = get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size);
3278   if (chunk != NULL) {
3279     return chunk;
3280   }
3281 
3282   return get_space_list(mdtype)->get_new_chunk(chunk_word_size, chunk_word_size, chunk_bunch);
3283 }
3284 
3285 void Metaspace::initialize(Mutex* lock, MetaspaceType type) {
3286 
3287   assert(space_list() != NULL,
3288     "Metadata VirtualSpaceList has not been initialized");
3289   assert(chunk_manager_metadata() != NULL,
3290     "Metadata ChunkManager has not been initialized");
3291 
3292   _vsm = new SpaceManager(NonClassType, lock);
3293   if (_vsm == NULL) {
3294     return;
3295   }
3296   size_t word_size;
3297   size_t class_word_size;
3298   vsm()->get_initial_chunk_sizes(type, &word_size, &class_word_size);
3299 
3300   if (using_class_space()) {
3301   assert(class_space_list() != NULL,
3302     "Class VirtualSpaceList has not been initialized");
3303   assert(chunk_manager_class() != NULL,
3304     "Class ChunkManager has not been initialized");
3305 
3306     // Allocate SpaceManager for classes.
3307     _class_vsm = new SpaceManager(ClassType, lock);
3308     if (_class_vsm == NULL) {
3309       return;
3310     }
3311   }
3312 
3313   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3314 
3315   // Allocate chunk for metadata objects
3316   Metachunk* new_chunk = get_initialization_chunk(NonClassType,
3317                                                   word_size,
3318                                                   vsm()->medium_chunk_bunch());
3319   assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
3320   if (new_chunk != NULL) {
3321     // Add to this manager's list of chunks in use and current_chunk().
3322     vsm()->add_chunk(new_chunk, true);
3323   }
3324 
3325   // Allocate chunk for class metadata objects
3326   if (using_class_space()) {
3327     Metachunk* class_chunk = get_initialization_chunk(ClassType,
3328                                                       class_word_size,
3329                                                       class_vsm()->medium_chunk_bunch());
3330     if (class_chunk != NULL) {
3331       class_vsm()->add_chunk(class_chunk, true);
3332     }
3333   }
3334 
3335   _alloc_record_head = NULL;
3336   _alloc_record_tail = NULL;
3337 }
3338 
3339 size_t Metaspace::align_word_size_up(size_t word_size) {
3340   size_t byte_size = word_size * wordSize;
3341   return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
3342 }
3343 
3344 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
3345   // DumpSharedSpaces doesn't use class metadata area (yet)
3346   // Also, don't use class_vsm() unless UseCompressedClassPointers is true.
3347   if (is_class_space_allocation(mdtype)) {
3348     return  class_vsm()->allocate(word_size);
3349   } else {
3350     return  vsm()->allocate(word_size);
3351   }
3352 }
3353 
3354 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
3355   size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
3356   assert(delta_bytes > 0, "Must be");
3357 
3358   size_t before = 0;
3359   size_t after = 0;
3360   MetaWord* res;
3361   bool incremented;
3362 
3363   // Each thread increments the HWM at most once. Even if the thread fails to increment
3364   // the HWM, an allocation is still attempted. This is because another thread must then
3365   // have incremented the HWM and therefore the allocation might still succeed.
3366   do {
3367     incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before);
3368     res = allocate(word_size, mdtype);
3369   } while (!incremented && res == NULL);
3370 
3371   if (incremented) {
3372     tracer()->report_gc_threshold(before, after,
3373                                   MetaspaceGCThresholdUpdater::ExpandAndAllocate);
3374     if (PrintGCDetails && Verbose) {
3375       gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
3376           " to " SIZE_FORMAT, before, after);
3377     }
3378   }
3379 
3380   return res;
3381 }
3382 
3383 // Space allocated in the Metaspace.  This may
3384 // be across several metadata virtual spaces.
3385 char* Metaspace::bottom() const {
3386   assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
3387   return (char*)vsm()->current_chunk()->bottom();
3388 }
3389 
3390 size_t Metaspace::used_words_slow(MetadataType mdtype) const {
3391   if (mdtype == ClassType) {
3392     return using_class_space() ? class_vsm()->sum_used_in_chunks_in_use() : 0;
3393   } else {
3394     return vsm()->sum_used_in_chunks_in_use();  // includes overhead!
3395   }
3396 }
3397 
3398 size_t Metaspace::free_words_slow(MetadataType mdtype) const {
3399   if (mdtype == ClassType) {
3400     return using_class_space() ? class_vsm()->sum_free_in_chunks_in_use() : 0;
3401   } else {
3402     return vsm()->sum_free_in_chunks_in_use();
3403   }
3404 }
3405 
3406 // Space capacity in the Metaspace.  It includes
3407 // space in the list of chunks from which allocations
3408 // have been made. Don't include space in the global freelist and
3409 // in the space available in the dictionary which
3410 // is already counted in some chunk.
3411 size_t Metaspace::capacity_words_slow(MetadataType mdtype) const {
3412   if (mdtype == ClassType) {
3413     return using_class_space() ? class_vsm()->sum_capacity_in_chunks_in_use() : 0;
3414   } else {
3415     return vsm()->sum_capacity_in_chunks_in_use();
3416   }
3417 }
3418 
3419 size_t Metaspace::used_bytes_slow(MetadataType mdtype) const {
3420   return used_words_slow(mdtype) * BytesPerWord;
3421 }
3422 
3423 size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const {
3424   return capacity_words_slow(mdtype) * BytesPerWord;
3425 }
3426 
3427 size_t Metaspace::allocated_blocks_bytes() const {
3428   return vsm()->allocated_blocks_bytes() +
3429       (using_class_space() ? class_vsm()->allocated_blocks_bytes() : 0);
3430 }
3431 
3432 size_t Metaspace::allocated_chunks_bytes() const {
3433   return vsm()->allocated_chunks_bytes() +
3434       (using_class_space() ? class_vsm()->allocated_chunks_bytes() : 0);
3435 }
3436 
3437 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
3438   assert(!SafepointSynchronize::is_at_safepoint()
3439          || Thread::current()->is_VM_thread(), "should be the VM thread");
3440 
3441   if (DumpSharedSpaces && PrintSharedSpaces) {
3442     record_deallocation(ptr, vsm()->get_raw_word_size(word_size));
3443   }
3444 
3445   MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
3446 
3447   if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
3448     // Dark matter.  Too small for dictionary.
3449 #ifdef ASSERT
3450     Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
3451 #endif
3452     return;
3453   }
3454   if (is_class && using_class_space()) {
3455     class_vsm()->deallocate(ptr, word_size);
3456   } else {
3457     vsm()->deallocate(ptr, word_size);
3458   }
3459 }
3460 
3461 
3462 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
3463                               bool read_only, MetaspaceObj::Type type, TRAPS) {
3464   if (HAS_PENDING_EXCEPTION) {
3465     assert(false, "Should not allocate with exception pending");
3466     return NULL;  // caller does a CHECK_NULL too
3467   }
3468 
3469   assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
3470         "ClassLoaderData::the_null_class_loader_data() should have been used.");
3471 
3472   // Allocate in metaspaces without taking out a lock, because it deadlocks
3473   // with the SymbolTable_lock.  Dumping is single threaded for now.  We'll have
3474   // to revisit this for application class data sharing.
3475   if (DumpSharedSpaces) {
3476     assert(type > MetaspaceObj::UnknownType && type < MetaspaceObj::_number_of_types, "sanity");
3477     Metaspace* space = read_only ? loader_data->ro_metaspace() : loader_data->rw_metaspace();
3478     MetaWord* result = space->allocate(word_size, NonClassType);
3479     if (result == NULL) {
3480       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
3481     }
3482     if (PrintSharedSpaces) {
3483       space->record_allocation(result, type, space->vsm()->get_raw_word_size(word_size));
3484     }
3485 
3486     // Zero initialize.
3487     Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3488 
3489     return result;
3490   }
3491 
3492   MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
3493 
3494   // Try to allocate metadata.
3495   MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
3496 
3497   if (result == NULL) {
3498     tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
3499 
3500     // Allocation failed.
3501     if (is_init_completed()) {
3502       // Only start a GC if the bootstrapping has completed.
3503 
3504       // Try to clean out some memory and retry.
3505       result = Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
3506           loader_data, word_size, mdtype);
3507     }
3508   }
3509 
3510   if (result == NULL) {
3511     report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL);
3512   }
3513 
3514   // Zero initialize.
3515   Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
3516 
3517   return result;
3518 }
3519 
3520 size_t Metaspace::class_chunk_size(size_t word_size) {
3521   assert(using_class_space(), "Has to use class space");
3522   return class_vsm()->calc_chunk_size(word_size);
3523 }
3524 
3525 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
3526   tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
3527 
3528   // If result is still null, we are out of memory.
3529   if (Verbose && TraceMetadataChunkAllocation) {
3530     gclog_or_tty->print_cr("Metaspace allocation failed for size "
3531         SIZE_FORMAT, word_size);
3532     if (loader_data->metaspace_or_null() != NULL) {
3533       loader_data->dump(gclog_or_tty);
3534     }
3535     MetaspaceAux::dump(gclog_or_tty);
3536   }
3537 
3538   bool out_of_compressed_class_space = false;
3539   if (is_class_space_allocation(mdtype)) {
3540     Metaspace* metaspace = loader_data->metaspace_non_null();
3541     out_of_compressed_class_space =
3542       MetaspaceAux::committed_bytes(Metaspace::ClassType) +
3543       (metaspace->class_chunk_size(word_size) * BytesPerWord) >
3544       CompressedClassSpaceSize;
3545   }
3546 
3547   // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
3548   const char* space_string = out_of_compressed_class_space ?
3549     "Compressed class space" : "Metaspace";
3550 
3551   report_java_out_of_memory(space_string);
3552 
3553   if (JvmtiExport::should_post_resource_exhausted()) {
3554     JvmtiExport::post_resource_exhausted(
3555         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
3556         space_string);
3557   }
3558 
3559   if (!is_init_completed()) {
3560     vm_exit_during_initialization("OutOfMemoryError", space_string);
3561   }
3562 
3563   if (out_of_compressed_class_space) {
3564     THROW_OOP(Universe::out_of_memory_error_class_metaspace());
3565   } else {
3566     THROW_OOP(Universe::out_of_memory_error_metaspace());
3567   }
3568 }
3569 
3570 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) {
3571   switch (mdtype) {
3572     case Metaspace::ClassType: return "Class";
3573     case Metaspace::NonClassType: return "Metadata";
3574     default:
3575       assert(false, err_msg("Got bad mdtype: %d", (int) mdtype));
3576       return NULL;
3577   }
3578 }
3579 
3580 void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
3581   assert(DumpSharedSpaces, "sanity");
3582 
3583   int byte_size = (int)word_size * HeapWordSize;
3584   AllocRecord *rec = new AllocRecord((address)ptr, type, byte_size);
3585 
3586   if (_alloc_record_head == NULL) {
3587     _alloc_record_head = _alloc_record_tail = rec;
3588   } else if (_alloc_record_tail->_ptr + _alloc_record_tail->_byte_size == (address)ptr) {
3589     _alloc_record_tail->_next = rec;
3590     _alloc_record_tail = rec;
3591   } else {
3592     // slow linear search, but this doesn't happen that often, and only when dumping
3593     for (AllocRecord *old = _alloc_record_head; old; old = old->_next) {
3594       if (old->_ptr == ptr) {
3595         assert(old->_type == MetaspaceObj::DeallocatedType, "sanity");
3596         int remain_bytes = old->_byte_size - byte_size;
3597         assert(remain_bytes >= 0, "sanity");
3598         old->_type = type;
3599 
3600         if (remain_bytes == 0) {
3601           delete(rec);
3602         } else {
3603           address remain_ptr = address(ptr) + byte_size;
3604           rec->_ptr = remain_ptr;
3605           rec->_byte_size = remain_bytes;
3606           rec->_type = MetaspaceObj::DeallocatedType;
3607           rec->_next = old->_next;
3608           old->_byte_size = byte_size;
3609           old->_next = rec;
3610         }
3611         return;
3612       }
3613     }
3614     assert(0, "reallocating a freed pointer that was not recorded");
3615   }
3616 }
3617 
3618 void Metaspace::record_deallocation(void* ptr, size_t word_size) {
3619   assert(DumpSharedSpaces, "sanity");
3620 
3621   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3622     if (rec->_ptr == ptr) {
3623       assert(rec->_byte_size == (int)word_size * HeapWordSize, "sanity");
3624       rec->_type = MetaspaceObj::DeallocatedType;
3625       return;
3626     }
3627   }
3628 
3629   assert(0, "deallocating a pointer that was not recorded");
3630 }
3631 
3632 void Metaspace::iterate(Metaspace::AllocRecordClosure *closure) {
3633   assert(DumpSharedSpaces, "unimplemented for !DumpSharedSpaces");
3634 
3635   address last_addr = (address)bottom();
3636 
3637   for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
3638     address ptr = rec->_ptr;
3639     if (last_addr < ptr) {
3640       closure->doit(last_addr, MetaspaceObj::UnknownType, ptr - last_addr);
3641     }
3642     closure->doit(ptr, rec->_type, rec->_byte_size);
3643     last_addr = ptr + rec->_byte_size;
3644   }
3645 
3646   address top = ((address)bottom()) + used_bytes_slow(Metaspace::NonClassType);
3647   if (last_addr < top) {
3648     closure->doit(last_addr, MetaspaceObj::UnknownType, top - last_addr);
3649   }
3650 }
3651 
3652 void Metaspace::purge(MetadataType mdtype) {
3653   get_space_list(mdtype)->purge(get_chunk_manager(mdtype));
3654 }
3655 
3656 void Metaspace::purge() {
3657   MutexLockerEx cl(SpaceManager::expand_lock(),
3658                    Mutex::_no_safepoint_check_flag);
3659   purge(NonClassType);
3660   if (using_class_space()) {
3661     purge(ClassType);
3662   }
3663 }
3664 
3665 void Metaspace::print_on(outputStream* out) const {
3666   // Print both class virtual space counts and metaspace.
3667   if (Verbose) {
3668     vsm()->print_on(out);
3669     if (using_class_space()) {
3670       class_vsm()->print_on(out);
3671     }
3672   }
3673 }
3674 
3675 bool Metaspace::contains(const void* ptr) {
3676   if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(ptr)) {
3677     return true;
3678   }
3679 
3680   if (using_class_space() && get_space_list(ClassType)->contains(ptr)) {
3681      return true;
3682   }
3683 
3684   return get_space_list(NonClassType)->contains(ptr);
3685 }
3686 
3687 void Metaspace::verify() {
3688   vsm()->verify();
3689   if (using_class_space()) {
3690     class_vsm()->verify();
3691   }
3692 }
3693 
3694 void Metaspace::dump(outputStream* const out) const {
3695   out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
3696   vsm()->dump(out);
3697   if (using_class_space()) {
3698     out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
3699     class_vsm()->dump(out);
3700   }
3701 }
3702 
3703 /////////////// Unit tests ///////////////
3704 
3705 #ifndef PRODUCT
3706 
3707 class TestMetaspaceAuxTest : AllStatic {
3708  public:
3709   static void test_reserved() {
3710     size_t reserved = MetaspaceAux::reserved_bytes();
3711 
3712     assert(reserved > 0, "assert");
3713 
3714     size_t committed  = MetaspaceAux::committed_bytes();
3715     assert(committed <= reserved, "assert");
3716 
3717     size_t reserved_metadata = MetaspaceAux::reserved_bytes(Metaspace::NonClassType);
3718     assert(reserved_metadata > 0, "assert");
3719     assert(reserved_metadata <= reserved, "assert");
3720 
3721     if (UseCompressedClassPointers) {
3722       size_t reserved_class    = MetaspaceAux::reserved_bytes(Metaspace::ClassType);
3723       assert(reserved_class > 0, "assert");
3724       assert(reserved_class < reserved, "assert");
3725     }
3726   }
3727 
3728   static void test_committed() {
3729     size_t committed = MetaspaceAux::committed_bytes();
3730 
3731     assert(committed > 0, "assert");
3732 
3733     size_t reserved  = MetaspaceAux::reserved_bytes();
3734     assert(committed <= reserved, "assert");
3735 
3736     size_t committed_metadata = MetaspaceAux::committed_bytes(Metaspace::NonClassType);
3737     assert(committed_metadata > 0, "assert");
3738     assert(committed_metadata <= committed, "assert");
3739 
3740     if (UseCompressedClassPointers) {
3741       size_t committed_class    = MetaspaceAux::committed_bytes(Metaspace::ClassType);
3742       assert(committed_class > 0, "assert");
3743       assert(committed_class < committed, "assert");
3744     }
3745   }
3746 
3747   static void test_virtual_space_list_large_chunk() {
3748     VirtualSpaceList* vs_list = new VirtualSpaceList(os::vm_allocation_granularity());
3749     MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3750     // A size larger than VirtualSpaceSize (256k) and add one page to make it _not_ be
3751     // vm_allocation_granularity aligned on Windows.
3752     size_t large_size = (size_t)(2*256*K + (os::vm_page_size()/BytesPerWord));
3753     large_size += (os::vm_page_size()/BytesPerWord);
3754     vs_list->get_new_chunk(large_size, large_size, 0);
3755   }
3756 
3757   static void test() {
3758     test_reserved();
3759     test_committed();
3760     test_virtual_space_list_large_chunk();
3761   }
3762 };
3763 
3764 void TestMetaspaceAux_test() {
3765   TestMetaspaceAuxTest::test();
3766 }
3767 
3768 class TestVirtualSpaceNodeTest {
3769   static void chunk_up(size_t words_left, size_t& num_medium_chunks,
3770                                           size_t& num_small_chunks,
3771                                           size_t& num_specialized_chunks) {
3772     num_medium_chunks = words_left / MediumChunk;
3773     words_left = words_left % MediumChunk;
3774 
3775     num_small_chunks = words_left / SmallChunk;
3776     words_left = words_left % SmallChunk;
3777     // how many specialized chunks can we get?
3778     num_specialized_chunks = words_left / SpecializedChunk;
3779     assert(words_left % SpecializedChunk == 0, "should be nothing left");
3780   }
3781 
3782  public:
3783   static void test() {
3784     MutexLockerEx ml(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
3785     const size_t vsn_test_size_words = MediumChunk  * 4;
3786     const size_t vsn_test_size_bytes = vsn_test_size_words * BytesPerWord;
3787 
3788     // The chunk sizes must be multiples of eachother, or this will fail
3789     STATIC_ASSERT(MediumChunk % SmallChunk == 0);
3790     STATIC_ASSERT(SmallChunk % SpecializedChunk == 0);
3791 
3792     { // No committed memory in VSN
3793       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3794       VirtualSpaceNode vsn(vsn_test_size_bytes);
3795       vsn.initialize();
3796       vsn.retire(&cm);
3797       assert(cm.sum_free_chunks_count() == 0, "did not commit any memory in the VSN");
3798     }
3799 
3800     { // All of VSN is committed, half is used by chunks
3801       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3802       VirtualSpaceNode vsn(vsn_test_size_bytes);
3803       vsn.initialize();
3804       vsn.expand_by(vsn_test_size_words, vsn_test_size_words);
3805       vsn.get_chunk_vs(MediumChunk);
3806       vsn.get_chunk_vs(MediumChunk);
3807       vsn.retire(&cm);
3808       assert(cm.sum_free_chunks_count() == 2, "should have been memory left for 2 medium chunks");
3809       assert(cm.sum_free_chunks() == 2*MediumChunk, "sizes should add up");
3810     }
3811 
3812     { // 4 pages of VSN is committed, some is used by chunks
3813       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3814       VirtualSpaceNode vsn(vsn_test_size_bytes);
3815       const size_t page_chunks = 4 * (size_t)os::vm_page_size() / BytesPerWord;
3816       assert(page_chunks < MediumChunk, "Test expects medium chunks to be at least 4*page_size");
3817       vsn.initialize();
3818       vsn.expand_by(page_chunks, page_chunks);
3819       vsn.get_chunk_vs(SmallChunk);
3820       vsn.get_chunk_vs(SpecializedChunk);
3821       vsn.retire(&cm);
3822 
3823       // committed - used = words left to retire
3824       const size_t words_left = page_chunks - SmallChunk - SpecializedChunk;
3825 
3826       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3827       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3828 
3829       assert(num_medium_chunks == 0, "should not get any medium chunks");
3830       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3831       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3832     }
3833 
3834     { // Half of VSN is committed, a humongous chunk is used
3835       ChunkManager cm(SpecializedChunk, SmallChunk, MediumChunk);
3836       VirtualSpaceNode vsn(vsn_test_size_bytes);
3837       vsn.initialize();
3838       vsn.expand_by(MediumChunk * 2, MediumChunk * 2);
3839       vsn.get_chunk_vs(MediumChunk + SpecializedChunk); // Humongous chunks will be aligned up to MediumChunk + SpecializedChunk
3840       vsn.retire(&cm);
3841 
3842       const size_t words_left = MediumChunk * 2 - (MediumChunk + SpecializedChunk);
3843       size_t num_medium_chunks, num_small_chunks, num_spec_chunks;
3844       chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks);
3845 
3846       assert(num_medium_chunks == 0, "should not get any medium chunks");
3847       assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks");
3848       assert(cm.sum_free_chunks() == words_left, "sizes should add up");
3849     }
3850 
3851   }
3852 
3853 #define assert_is_available_positive(word_size) \
3854   assert(vsn.is_available(word_size), \
3855     err_msg(#word_size ": " PTR_FORMAT " bytes were not available in " \
3856             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3857             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3858 
3859 #define assert_is_available_negative(word_size) \
3860   assert(!vsn.is_available(word_size), \
3861     err_msg(#word_size ": " PTR_FORMAT " bytes should not be available in " \
3862             "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \
3863             (uintptr_t)(word_size * BytesPerWord), vsn.bottom(), vsn.end()));
3864 
3865   static void test_is_available_positive() {
3866     // Reserve some memory.
3867     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3868     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3869 
3870     // Commit some memory.
3871     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3872     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3873     assert(expanded, "Failed to commit");
3874 
3875     // Check that is_available accepts the committed size.
3876     assert_is_available_positive(commit_word_size);
3877 
3878     // Check that is_available accepts half the committed size.
3879     size_t expand_word_size = commit_word_size / 2;
3880     assert_is_available_positive(expand_word_size);
3881   }
3882 
3883   static void test_is_available_negative() {
3884     // Reserve some memory.
3885     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3886     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3887 
3888     // Commit some memory.
3889     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3890     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3891     assert(expanded, "Failed to commit");
3892 
3893     // Check that is_available doesn't accept a too large size.
3894     size_t two_times_commit_word_size = commit_word_size * 2;
3895     assert_is_available_negative(two_times_commit_word_size);
3896   }
3897 
3898   static void test_is_available_overflow() {
3899     // Reserve some memory.
3900     VirtualSpaceNode vsn(os::vm_allocation_granularity());
3901     assert(vsn.initialize(), "Failed to setup VirtualSpaceNode");
3902 
3903     // Commit some memory.
3904     size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord;
3905     bool expanded = vsn.expand_by(commit_word_size, commit_word_size);
3906     assert(expanded, "Failed to commit");
3907 
3908     // Calculate a size that will overflow the virtual space size.
3909     void* virtual_space_max = (void*)(uintptr_t)-1;
3910     size_t bottom_to_max = pointer_delta(virtual_space_max, vsn.bottom(), 1);
3911     size_t overflow_size = bottom_to_max + BytesPerWord;
3912     size_t overflow_word_size = overflow_size / BytesPerWord;
3913 
3914     // Check that is_available can handle the overflow.
3915     assert_is_available_negative(overflow_word_size);
3916   }
3917 
3918   static void test_is_available() {
3919     TestVirtualSpaceNodeTest::test_is_available_positive();
3920     TestVirtualSpaceNodeTest::test_is_available_negative();
3921     TestVirtualSpaceNodeTest::test_is_available_overflow();
3922   }
3923 };
3924 
3925 void TestVirtualSpaceNode_test() {
3926   TestVirtualSpaceNodeTest::test();
3927   TestVirtualSpaceNodeTest::test_is_available();
3928 }
3929 #endif