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