src/share/vm/memory/metaspace.cpp

Tue, 12 Feb 2013 14:15:45 -0800

author
jmasa
date
Tue, 12 Feb 2013 14:15:45 -0800
changeset 5015
868d87ed63c8
parent 5007
c23dbf0e8ab7
child 5023
601183f604b2
permissions
-rw-r--r--

8008966: NPG: Inefficient Metaspace counter functions cause large young GC regressions
Reviewed-by: mgerdin, coleenp

     1 /*
     2  * Copyright (c) 2011, 2013, 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/binaryTreeDictionary.hpp"
    27 #include "memory/freeList.hpp"
    28 #include "memory/collectorPolicy.hpp"
    29 #include "memory/filemap.hpp"
    30 #include "memory/freeList.hpp"
    31 #include "memory/metablock.hpp"
    32 #include "memory/metachunk.hpp"
    33 #include "memory/metaspace.hpp"
    34 #include "memory/metaspaceShared.hpp"
    35 #include "memory/resourceArea.hpp"
    36 #include "memory/universe.hpp"
    37 #include "runtime/globals.hpp"
    38 #include "runtime/mutex.hpp"
    39 #include "runtime/orderAccess.hpp"
    40 #include "services/memTracker.hpp"
    41 #include "utilities/copy.hpp"
    42 #include "utilities/debug.hpp"
    44 typedef BinaryTreeDictionary<Metablock, FreeList> BlockTreeDictionary;
    45 typedef BinaryTreeDictionary<Metachunk, FreeList> ChunkTreeDictionary;
    46 // Define this macro to enable slow integrity checking of
    47 // the free chunk lists
    48 const bool metaspace_slow_verify = false;
    50 // Parameters for stress mode testing
    51 const uint metadata_deallocate_a_lot_block = 10;
    52 const uint metadata_deallocate_a_lock_chunk = 3;
    53 size_t const allocation_from_dictionary_limit = 64 * K;
    55 MetaWord* last_allocated = 0;
    57 // Used in declarations in SpaceManager and ChunkManager
    58 enum ChunkIndex {
    59   ZeroIndex = 0,
    60   SpecializedIndex = ZeroIndex,
    61   SmallIndex = SpecializedIndex + 1,
    62   MediumIndex = SmallIndex + 1,
    63   HumongousIndex = MediumIndex + 1,
    64   NumberOfFreeLists = 3,
    65   NumberOfInUseLists = 4
    66 };
    68 enum ChunkSizes {    // in words.
    69   ClassSpecializedChunk = 128,
    70   SpecializedChunk = 128,
    71   ClassSmallChunk = 256,
    72   SmallChunk = 512,
    73   ClassMediumChunk = 1 * K,
    74   MediumChunk = 8 * K,
    75   HumongousChunkGranularity = 8
    76 };
    78 static ChunkIndex next_chunk_index(ChunkIndex i) {
    79   assert(i < NumberOfInUseLists, "Out of bound");
    80   return (ChunkIndex) (i+1);
    81 }
    83 // Originally _capacity_until_GC was set to MetaspaceSize here but
    84 // the default MetaspaceSize before argument processing was being
    85 // used which was not the desired value.  See the code
    86 // in should_expand() to see how the initialization is handled
    87 // now.
    88 size_t MetaspaceGC::_capacity_until_GC = 0;
    89 bool MetaspaceGC::_expand_after_GC = false;
    90 uint MetaspaceGC::_shrink_factor = 0;
    91 bool MetaspaceGC::_should_concurrent_collect = false;
    93 // Blocks of space for metadata are allocated out of Metachunks.
    94 //
    95 // Metachunk are allocated out of MetadataVirtualspaces and once
    96 // allocated there is no explicit link between a Metachunk and
    97 // the MetadataVirtualspaces from which it was allocated.
    98 //
    99 // Each SpaceManager maintains a
   100 // list of the chunks it is using and the current chunk.  The current
   101 // chunk is the chunk from which allocations are done.  Space freed in
   102 // a chunk is placed on the free list of blocks (BlockFreelist) and
   103 // reused from there.
   105 typedef class FreeList<Metachunk> ChunkList;
   107 // Manages the global free lists of chunks.
   108 // Has three lists of free chunks, and a total size and
   109 // count that includes all three
   111 class ChunkManager VALUE_OBJ_CLASS_SPEC {
   113   // Free list of chunks of different sizes.
   114   //   SpecializedChunk
   115   //   SmallChunk
   116   //   MediumChunk
   117   //   HumongousChunk
   118   ChunkList _free_chunks[NumberOfFreeLists];
   121   //   HumongousChunk
   122   ChunkTreeDictionary _humongous_dictionary;
   124   // ChunkManager in all lists of this type
   125   size_t _free_chunks_total;
   126   size_t _free_chunks_count;
   128   void dec_free_chunks_total(size_t v) {
   129     assert(_free_chunks_count > 0 &&
   130              _free_chunks_total > 0,
   131              "About to go negative");
   132     Atomic::add_ptr(-1, &_free_chunks_count);
   133     jlong minus_v = (jlong) - (jlong) v;
   134     Atomic::add_ptr(minus_v, &_free_chunks_total);
   135   }
   137   // Debug support
   139   size_t sum_free_chunks();
   140   size_t sum_free_chunks_count();
   142   void locked_verify_free_chunks_total();
   143   void slow_locked_verify_free_chunks_total() {
   144     if (metaspace_slow_verify) {
   145       locked_verify_free_chunks_total();
   146     }
   147   }
   148   void locked_verify_free_chunks_count();
   149   void slow_locked_verify_free_chunks_count() {
   150     if (metaspace_slow_verify) {
   151       locked_verify_free_chunks_count();
   152     }
   153   }
   154   void verify_free_chunks_count();
   156  public:
   158   ChunkManager() : _free_chunks_total(0), _free_chunks_count(0) {}
   160   // add or delete (return) a chunk to the global freelist.
   161   Metachunk* chunk_freelist_allocate(size_t word_size);
   162   void chunk_freelist_deallocate(Metachunk* chunk);
   164   // Map a size to a list index assuming that there are lists
   165   // for special, small, medium, and humongous chunks.
   166   static ChunkIndex list_index(size_t size);
   168   // Remove the chunk from its freelist.  It is
   169   // expected to be on one of the _free_chunks[] lists.
   170   void remove_chunk(Metachunk* chunk);
   172   // Add the simple linked list of chunks to the freelist of chunks
   173   // of type index.
   174   void return_chunks(ChunkIndex index, Metachunk* chunks);
   176   // Total of the space in the free chunks list
   177   size_t free_chunks_total();
   178   size_t free_chunks_total_in_bytes();
   180   // Number of chunks in the free chunks list
   181   size_t free_chunks_count();
   183   void inc_free_chunks_total(size_t v, size_t count = 1) {
   184     Atomic::add_ptr(count, &_free_chunks_count);
   185     Atomic::add_ptr(v, &_free_chunks_total);
   186   }
   187   ChunkTreeDictionary* humongous_dictionary() {
   188     return &_humongous_dictionary;
   189   }
   191   ChunkList* free_chunks(ChunkIndex index);
   193   // Returns the list for the given chunk word size.
   194   ChunkList* find_free_chunks_list(size_t word_size);
   196   // Add and remove from a list by size.  Selects
   197   // list based on size of chunk.
   198   void free_chunks_put(Metachunk* chuck);
   199   Metachunk* free_chunks_get(size_t chunk_word_size);
   201   // Debug support
   202   void verify();
   203   void slow_verify() {
   204     if (metaspace_slow_verify) {
   205       verify();
   206     }
   207   }
   208   void locked_verify();
   209   void slow_locked_verify() {
   210     if (metaspace_slow_verify) {
   211       locked_verify();
   212     }
   213   }
   214   void verify_free_chunks_total();
   216   void locked_print_free_chunks(outputStream* st);
   217   void locked_print_sum_free_chunks(outputStream* st);
   219   void print_on(outputStream* st);
   220 };
   222 // Used to manage the free list of Metablocks (a block corresponds
   223 // to the allocation of a quantum of metadata).
   224 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
   225   BlockTreeDictionary* _dictionary;
   226   static Metablock* initialize_free_chunk(MetaWord* p, size_t word_size);
   228   // Accessors
   229   BlockTreeDictionary* dictionary() const { return _dictionary; }
   231  public:
   232   BlockFreelist();
   233   ~BlockFreelist();
   235   // Get and return a block to the free list
   236   MetaWord* get_block(size_t word_size);
   237   void return_block(MetaWord* p, size_t word_size);
   239   size_t total_size() {
   240   if (dictionary() == NULL) {
   241     return 0;
   242   } else {
   243     return dictionary()->total_size();
   244   }
   245 }
   247   void print_on(outputStream* st) const;
   248 };
   250 class VirtualSpaceNode : public CHeapObj<mtClass> {
   251   friend class VirtualSpaceList;
   253   // Link to next VirtualSpaceNode
   254   VirtualSpaceNode* _next;
   256   // total in the VirtualSpace
   257   MemRegion _reserved;
   258   ReservedSpace _rs;
   259   VirtualSpace _virtual_space;
   260   MetaWord* _top;
   261   // count of chunks contained in this VirtualSpace
   262   uintx _container_count;
   264   // Convenience functions for logical bottom and end
   265   MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
   266   MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
   268   // Convenience functions to access the _virtual_space
   269   char* low()  const { return virtual_space()->low(); }
   270   char* high() const { return virtual_space()->high(); }
   272   // The first Metachunk will be allocated at the bottom of the
   273   // VirtualSpace
   274   Metachunk* first_chunk() { return (Metachunk*) bottom(); }
   276   void inc_container_count();
   277 #ifdef ASSERT
   278   uint container_count_slow();
   279 #endif
   281  public:
   283   VirtualSpaceNode(size_t byte_size);
   284   VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs), _container_count(0) {}
   285   ~VirtualSpaceNode();
   287   // address of next available space in _virtual_space;
   288   // Accessors
   289   VirtualSpaceNode* next() { return _next; }
   290   void set_next(VirtualSpaceNode* v) { _next = v; }
   292   void set_reserved(MemRegion const v) { _reserved = v; }
   293   void set_top(MetaWord* v) { _top = v; }
   295   // Accessors
   296   MemRegion* reserved() { return &_reserved; }
   297   VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
   299   // Returns true if "word_size" is available in the VirtualSpace
   300   bool is_available(size_t word_size) { return _top + word_size <= end(); }
   302   MetaWord* top() const { return _top; }
   303   void inc_top(size_t word_size) { _top += word_size; }
   305   uintx container_count() { return _container_count; }
   306   void dec_container_count();
   307 #ifdef ASSERT
   308   void verify_container_count();
   309 #endif
   311   // used and capacity in this single entry in the list
   312   size_t used_words_in_vs() const;
   313   size_t capacity_words_in_vs() const;
   314   size_t free_words_in_vs() const;
   316   bool initialize();
   318   // get space from the virtual space
   319   Metachunk* take_from_committed(size_t chunk_word_size);
   321   // Allocate a chunk from the virtual space and return it.
   322   Metachunk* get_chunk_vs(size_t chunk_word_size);
   323   Metachunk* get_chunk_vs_with_expand(size_t chunk_word_size);
   325   // Expands/shrinks the committed space in a virtual space.  Delegates
   326   // to Virtualspace
   327   bool expand_by(size_t words, bool pre_touch = false);
   328   bool shrink_by(size_t words);
   330   // In preparation for deleting this node, remove all the chunks
   331   // in the node from any freelist.
   332   void purge(ChunkManager* chunk_manager);
   334 #ifdef ASSERT
   335   // Debug support
   336   static void verify_virtual_space_total();
   337   static void verify_virtual_space_count();
   338   void mangle();
   339 #endif
   341   void print_on(outputStream* st) const;
   342 };
   344   // byte_size is the size of the associated virtualspace.
   345 VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(0), _container_count(0) {
   346   // align up to vm allocation granularity
   347   byte_size = align_size_up(byte_size, os::vm_allocation_granularity());
   349   // This allocates memory with mmap.  For DumpSharedspaces, try to reserve
   350   // configurable address, generally at the top of the Java heap so other
   351   // memory addresses don't conflict.
   352   if (DumpSharedSpaces) {
   353     char* shared_base = (char*)SharedBaseAddress;
   354     _rs = ReservedSpace(byte_size, 0, false, shared_base, 0);
   355     if (_rs.is_reserved()) {
   356       assert(shared_base == 0 || _rs.base() == shared_base, "should match");
   357     } else {
   358       // Get a mmap region anywhere if the SharedBaseAddress fails.
   359       _rs = ReservedSpace(byte_size);
   360     }
   361     MetaspaceShared::set_shared_rs(&_rs);
   362   } else {
   363     _rs = ReservedSpace(byte_size);
   364   }
   366   MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
   367 }
   369 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
   370   Metachunk* chunk = first_chunk();
   371   Metachunk* invalid_chunk = (Metachunk*) top();
   372   while (chunk < invalid_chunk ) {
   373     assert(chunk->is_free(), "Should be marked free");
   374       MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
   375       chunk_manager->remove_chunk(chunk);
   376       assert(chunk->next() == NULL &&
   377              chunk->prev() == NULL,
   378              "Was not removed from its list");
   379       chunk = (Metachunk*) next;
   380   }
   381 }
   383 #ifdef ASSERT
   384 uint VirtualSpaceNode::container_count_slow() {
   385   uint count = 0;
   386   Metachunk* chunk = first_chunk();
   387   Metachunk* invalid_chunk = (Metachunk*) top();
   388   while (chunk < invalid_chunk ) {
   389     MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
   390     // Don't count the chunks on the free lists.  Those are
   391     // still part of the VirtualSpaceNode but not currently
   392     // counted.
   393     if (!chunk->is_free()) {
   394       count++;
   395     }
   396     chunk = (Metachunk*) next;
   397   }
   398   return count;
   399 }
   400 #endif
   402 // List of VirtualSpaces for metadata allocation.
   403 // It has a  _next link for singly linked list and a MemRegion
   404 // for total space in the VirtualSpace.
   405 class VirtualSpaceList : public CHeapObj<mtClass> {
   406   friend class VirtualSpaceNode;
   408   enum VirtualSpaceSizes {
   409     VirtualSpaceSize = 256 * K
   410   };
   412   // Global list of virtual spaces
   413   // Head of the list
   414   VirtualSpaceNode* _virtual_space_list;
   415   // virtual space currently being used for allocations
   416   VirtualSpaceNode* _current_virtual_space;
   417   // Free chunk list for all other metadata
   418   ChunkManager      _chunk_manager;
   420   // Can this virtual list allocate >1 spaces?  Also, used to determine
   421   // whether to allocate unlimited small chunks in this virtual space
   422   bool _is_class;
   423   bool can_grow() const { return !is_class() || !UseCompressedKlassPointers; }
   425   // Sum of space in all virtual spaces and number of virtual spaces
   426   size_t _virtual_space_total;
   427   size_t _virtual_space_count;
   429   ~VirtualSpaceList();
   431   VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
   433   void set_virtual_space_list(VirtualSpaceNode* v) {
   434     _virtual_space_list = v;
   435   }
   436   void set_current_virtual_space(VirtualSpaceNode* v) {
   437     _current_virtual_space = v;
   438   }
   440   void link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size);
   442   // Get another virtual space and add it to the list.  This
   443   // is typically prompted by a failed attempt to allocate a chunk
   444   // and is typically followed by the allocation of a chunk.
   445   bool grow_vs(size_t vs_word_size);
   447  public:
   448   VirtualSpaceList(size_t word_size);
   449   VirtualSpaceList(ReservedSpace rs);
   451   size_t free_bytes();
   453   Metachunk* get_new_chunk(size_t word_size,
   454                            size_t grow_chunks_by_words,
   455                            size_t medium_chunk_bunch);
   457   // Get the first chunk for a Metaspace.  Used for
   458   // special cases such as the boot class loader, reflection
   459   // class loader and anonymous class loader.
   460   Metachunk* get_initialization_chunk(size_t word_size, size_t chunk_bunch);
   462   VirtualSpaceNode* current_virtual_space() {
   463     return _current_virtual_space;
   464   }
   466   ChunkManager* chunk_manager() { return &_chunk_manager; }
   467   bool is_class() const { return _is_class; }
   469   // Allocate the first virtualspace.
   470   void initialize(size_t word_size);
   472   size_t virtual_space_total() { return _virtual_space_total; }
   474   void inc_virtual_space_total(size_t v);
   475   void dec_virtual_space_total(size_t v);
   476   void inc_virtual_space_count();
   477   void dec_virtual_space_count();
   479   // Unlink empty VirtualSpaceNodes and free it.
   480   void purge();
   482   // Used and capacity in the entire list of virtual spaces.
   483   // These are global values shared by all Metaspaces
   484   size_t capacity_words_sum();
   485   size_t capacity_bytes_sum() { return capacity_words_sum() * BytesPerWord; }
   486   size_t used_words_sum();
   487   size_t used_bytes_sum() { return used_words_sum() * BytesPerWord; }
   489   bool contains(const void *ptr);
   491   void print_on(outputStream* st) const;
   493   class VirtualSpaceListIterator : public StackObj {
   494     VirtualSpaceNode* _virtual_spaces;
   495    public:
   496     VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
   497       _virtual_spaces(virtual_spaces) {}
   499     bool repeat() {
   500       return _virtual_spaces != NULL;
   501     }
   503     VirtualSpaceNode* get_next() {
   504       VirtualSpaceNode* result = _virtual_spaces;
   505       if (_virtual_spaces != NULL) {
   506         _virtual_spaces = _virtual_spaces->next();
   507       }
   508       return result;
   509     }
   510   };
   511 };
   513 class Metadebug : AllStatic {
   514   // Debugging support for Metaspaces
   515   static int _deallocate_block_a_lot_count;
   516   static int _deallocate_chunk_a_lot_count;
   517   static int _allocation_fail_alot_count;
   519  public:
   520   static int deallocate_block_a_lot_count() {
   521     return _deallocate_block_a_lot_count;
   522   }
   523   static void set_deallocate_block_a_lot_count(int v) {
   524     _deallocate_block_a_lot_count = v;
   525   }
   526   static void inc_deallocate_block_a_lot_count() {
   527     _deallocate_block_a_lot_count++;
   528   }
   529   static int deallocate_chunk_a_lot_count() {
   530     return _deallocate_chunk_a_lot_count;
   531   }
   532   static void reset_deallocate_chunk_a_lot_count() {
   533     _deallocate_chunk_a_lot_count = 1;
   534   }
   535   static void inc_deallocate_chunk_a_lot_count() {
   536     _deallocate_chunk_a_lot_count++;
   537   }
   539   static void init_allocation_fail_alot_count();
   540 #ifdef ASSERT
   541   static bool test_metadata_failure();
   542 #endif
   544   static void deallocate_chunk_a_lot(SpaceManager* sm,
   545                                      size_t chunk_word_size);
   546   static void deallocate_block_a_lot(SpaceManager* sm,
   547                                      size_t chunk_word_size);
   549 };
   551 int Metadebug::_deallocate_block_a_lot_count = 0;
   552 int Metadebug::_deallocate_chunk_a_lot_count = 0;
   553 int Metadebug::_allocation_fail_alot_count = 0;
   555 //  SpaceManager - used by Metaspace to handle allocations
   556 class SpaceManager : public CHeapObj<mtClass> {
   557   friend class Metaspace;
   558   friend class Metadebug;
   560  private:
   562   // protects allocations and contains.
   563   Mutex* const _lock;
   565   // Chunk related size
   566   size_t _medium_chunk_bunch;
   568   // List of chunks in use by this SpaceManager.  Allocations
   569   // are done from the current chunk.  The list is used for deallocating
   570   // chunks when the SpaceManager is freed.
   571   Metachunk* _chunks_in_use[NumberOfInUseLists];
   572   Metachunk* _current_chunk;
   574   // Virtual space where allocation comes from.
   575   VirtualSpaceList* _vs_list;
   577   // Number of small chunks to allocate to a manager
   578   // If class space manager, small chunks are unlimited
   579   static uint const _small_chunk_limit;
   580   bool has_small_chunk_limit() { return !vs_list()->is_class(); }
   582   // Sum of all space in allocated chunks
   583   size_t _allocated_blocks_words;
   585   // Sum of all allocated chunks
   586   size_t _allocated_chunks_words;
   587   size_t _allocated_chunks_count;
   589   // Free lists of blocks are per SpaceManager since they
   590   // are assumed to be in chunks in use by the SpaceManager
   591   // and all chunks in use by a SpaceManager are freed when
   592   // the class loader using the SpaceManager is collected.
   593   BlockFreelist _block_freelists;
   595   // protects virtualspace and chunk expansions
   596   static const char*  _expand_lock_name;
   597   static const int    _expand_lock_rank;
   598   static Mutex* const _expand_lock;
   600  private:
   601   // Accessors
   602   Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
   603   void set_chunks_in_use(ChunkIndex index, Metachunk* v) { _chunks_in_use[index] = v; }
   605   BlockFreelist* block_freelists() const {
   606     return (BlockFreelist*) &_block_freelists;
   607   }
   609   VirtualSpaceList* vs_list() const    { return _vs_list; }
   611   Metachunk* current_chunk() const { return _current_chunk; }
   612   void set_current_chunk(Metachunk* v) {
   613     _current_chunk = v;
   614   }
   616   Metachunk* find_current_chunk(size_t word_size);
   618   // Add chunk to the list of chunks in use
   619   void add_chunk(Metachunk* v, bool make_current);
   621   Mutex* lock() const { return _lock; }
   623   const char* chunk_size_name(ChunkIndex index) const;
   625  protected:
   626   void initialize();
   628  public:
   629   SpaceManager(Mutex* lock,
   630                VirtualSpaceList* vs_list);
   631   ~SpaceManager();
   633   enum ChunkMultiples {
   634     MediumChunkMultiple = 4
   635   };
   637   // Accessors
   638   size_t specialized_chunk_size() { return SpecializedChunk; }
   639   size_t small_chunk_size() { return (size_t) vs_list()->is_class() ? ClassSmallChunk : SmallChunk; }
   640   size_t medium_chunk_size() { return (size_t) vs_list()->is_class() ? ClassMediumChunk : MediumChunk; }
   641   size_t medium_chunk_bunch() { return medium_chunk_size() * MediumChunkMultiple; }
   643   size_t allocated_blocks_words() const { return _allocated_blocks_words; }
   644   size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; }
   645   size_t allocated_chunks_words() const { return _allocated_chunks_words; }
   646   size_t allocated_chunks_count() const { return _allocated_chunks_count; }
   648   bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
   650   static Mutex* expand_lock() { return _expand_lock; }
   652   // Increment the per Metaspace and global running sums for Metachunks
   653   // by the given size.  This is used when a Metachunk to added to
   654   // the in-use list.
   655   void inc_size_metrics(size_t words);
   656   // Increment the per Metaspace and global running sums Metablocks by the given
   657   // size.  This is used when a Metablock is allocated.
   658   void inc_used_metrics(size_t words);
   659   // Delete the portion of the running sums for this SpaceManager. That is,
   660   // the globals running sums for the Metachunks and Metablocks are
   661   // decremented for all the Metachunks in-use by this SpaceManager.
   662   void dec_total_from_size_metrics();
   664   // Set the sizes for the initial chunks.
   665   void get_initial_chunk_sizes(Metaspace::MetaspaceType type,
   666                                size_t* chunk_word_size,
   667                                size_t* class_chunk_word_size);
   669   size_t sum_capacity_in_chunks_in_use() const;
   670   size_t sum_used_in_chunks_in_use() const;
   671   size_t sum_free_in_chunks_in_use() const;
   672   size_t sum_waste_in_chunks_in_use() const;
   673   size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
   675   size_t sum_count_in_chunks_in_use();
   676   size_t sum_count_in_chunks_in_use(ChunkIndex i);
   678   Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
   680   // Block allocation and deallocation.
   681   // Allocates a block from the current chunk
   682   MetaWord* allocate(size_t word_size);
   684   // Helper for allocations
   685   MetaWord* allocate_work(size_t word_size);
   687   // Returns a block to the per manager freelist
   688   void deallocate(MetaWord* p, size_t word_size);
   690   // Based on the allocation size and a minimum chunk size,
   691   // returned chunk size (for expanding space for chunk allocation).
   692   size_t calc_chunk_size(size_t allocation_word_size);
   694   // Called when an allocation from the current chunk fails.
   695   // Gets a new chunk (may require getting a new virtual space),
   696   // and allocates from that chunk.
   697   MetaWord* grow_and_allocate(size_t word_size);
   699   // debugging support.
   701   void dump(outputStream* const out) const;
   702   void print_on(outputStream* st) const;
   703   void locked_print_chunks_in_use_on(outputStream* st) const;
   705   void verify();
   706   void verify_chunk_size(Metachunk* chunk);
   707   NOT_PRODUCT(void mangle_freed_chunks();)
   708 #ifdef ASSERT
   709   void verify_allocated_blocks_words();
   710 #endif
   711 };
   713 uint const SpaceManager::_small_chunk_limit = 4;
   715 const char* SpaceManager::_expand_lock_name =
   716   "SpaceManager chunk allocation lock";
   717 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
   718 Mutex* const SpaceManager::_expand_lock =
   719   new Mutex(SpaceManager::_expand_lock_rank,
   720             SpaceManager::_expand_lock_name,
   721             Mutex::_allow_vm_block_flag);
   723 void VirtualSpaceNode::inc_container_count() {
   724   assert_lock_strong(SpaceManager::expand_lock());
   725   _container_count++;
   726   assert(_container_count == container_count_slow(),
   727          err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
   728                  "container_count_slow() " SIZE_FORMAT,
   729                  _container_count, container_count_slow()));
   730 }
   732 void VirtualSpaceNode::dec_container_count() {
   733   assert_lock_strong(SpaceManager::expand_lock());
   734   _container_count--;
   735 }
   737 #ifdef ASSERT
   738 void VirtualSpaceNode::verify_container_count() {
   739   assert(_container_count == container_count_slow(),
   740     err_msg("Inconsistency in countainer_count _container_count " SIZE_FORMAT
   741             "container_count_slow() " SIZE_FORMAT, _container_count, container_count_slow()));
   742 }
   743 #endif
   745 // BlockFreelist methods
   747 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
   749 BlockFreelist::~BlockFreelist() {
   750   if (_dictionary != NULL) {
   751     if (Verbose && TraceMetadataChunkAllocation) {
   752       _dictionary->print_free_lists(gclog_or_tty);
   753     }
   754     delete _dictionary;
   755   }
   756 }
   758 Metablock* BlockFreelist::initialize_free_chunk(MetaWord* p, size_t word_size) {
   759   Metablock* block = (Metablock*) p;
   760   block->set_word_size(word_size);
   761   block->set_prev(NULL);
   762   block->set_next(NULL);
   764   return block;
   765 }
   767 void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
   768   Metablock* free_chunk = initialize_free_chunk(p, word_size);
   769   if (dictionary() == NULL) {
   770    _dictionary = new BlockTreeDictionary();
   771   }
   772   dictionary()->return_chunk(free_chunk);
   773 }
   775 MetaWord* BlockFreelist::get_block(size_t word_size) {
   776   if (dictionary() == NULL) {
   777     return NULL;
   778   }
   780   if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
   781     // Dark matter.  Too small for dictionary.
   782     return NULL;
   783   }
   785   Metablock* free_block =
   786     dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::exactly);
   787   if (free_block == NULL) {
   788     return NULL;
   789   }
   791   return (MetaWord*) free_block;
   792 }
   794 void BlockFreelist::print_on(outputStream* st) const {
   795   if (dictionary() == NULL) {
   796     return;
   797   }
   798   dictionary()->print_free_lists(st);
   799 }
   801 // VirtualSpaceNode methods
   803 VirtualSpaceNode::~VirtualSpaceNode() {
   804   _rs.release();
   805 #ifdef ASSERT
   806   size_t word_size = sizeof(*this) / BytesPerWord;
   807   Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
   808 #endif
   809 }
   811 size_t VirtualSpaceNode::used_words_in_vs() const {
   812   return pointer_delta(top(), bottom(), sizeof(MetaWord));
   813 }
   815 // Space committed in the VirtualSpace
   816 size_t VirtualSpaceNode::capacity_words_in_vs() const {
   817   return pointer_delta(end(), bottom(), sizeof(MetaWord));
   818 }
   820 size_t VirtualSpaceNode::free_words_in_vs() const {
   821   return pointer_delta(end(), top(), sizeof(MetaWord));
   822 }
   824 // Allocates the chunk from the virtual space only.
   825 // This interface is also used internally for debugging.  Not all
   826 // chunks removed here are necessarily used for allocation.
   827 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
   828   // Bottom of the new chunk
   829   MetaWord* chunk_limit = top();
   830   assert(chunk_limit != NULL, "Not safe to call this method");
   832   if (!is_available(chunk_word_size)) {
   833     if (TraceMetadataChunkAllocation) {
   834       tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
   835       // Dump some information about the virtual space that is nearly full
   836       print_on(tty);
   837     }
   838     return NULL;
   839   }
   841   // Take the space  (bump top on the current virtual space).
   842   inc_top(chunk_word_size);
   844   // Initialize the chunk
   845   Metachunk* result = ::new (chunk_limit) Metachunk(chunk_word_size, this);
   846   return result;
   847 }
   850 // Expand the virtual space (commit more of the reserved space)
   851 bool VirtualSpaceNode::expand_by(size_t words, bool pre_touch) {
   852   size_t bytes = words * BytesPerWord;
   853   bool result =  virtual_space()->expand_by(bytes, pre_touch);
   854   if (TraceMetavirtualspaceAllocation && !result) {
   855     gclog_or_tty->print_cr("VirtualSpaceNode::expand_by() failed "
   856                            "for byte size " SIZE_FORMAT, bytes);
   857     virtual_space()->print();
   858   }
   859   return result;
   860 }
   862 // Shrink the virtual space (commit more of the reserved space)
   863 bool VirtualSpaceNode::shrink_by(size_t words) {
   864   size_t bytes = words * BytesPerWord;
   865   virtual_space()->shrink_by(bytes);
   866   return true;
   867 }
   869 // Add another chunk to the chunk list.
   871 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
   872   assert_lock_strong(SpaceManager::expand_lock());
   873   Metachunk* result = take_from_committed(chunk_word_size);
   874   if (result != NULL) {
   875     inc_container_count();
   876   }
   877   return result;
   878 }
   880 Metachunk* VirtualSpaceNode::get_chunk_vs_with_expand(size_t chunk_word_size) {
   881   assert_lock_strong(SpaceManager::expand_lock());
   883   Metachunk* new_chunk = get_chunk_vs(chunk_word_size);
   885   if (new_chunk == NULL) {
   886     // Only a small part of the virtualspace is committed when first
   887     // allocated so committing more here can be expected.
   888     size_t page_size_words = os::vm_page_size() / BytesPerWord;
   889     size_t aligned_expand_vs_by_words = align_size_up(chunk_word_size,
   890                                                     page_size_words);
   891     expand_by(aligned_expand_vs_by_words, false);
   892     new_chunk = get_chunk_vs(chunk_word_size);
   893   }
   894   return new_chunk;
   895 }
   897 bool VirtualSpaceNode::initialize() {
   899   if (!_rs.is_reserved()) {
   900     return false;
   901   }
   903   // An allocation out of this Virtualspace that is larger
   904   // than an initial commit size can waste that initial committed
   905   // space.
   906   size_t committed_byte_size = 0;
   907   bool result = virtual_space()->initialize(_rs, committed_byte_size);
   908   if (result) {
   909     set_top((MetaWord*)virtual_space()->low());
   910     set_reserved(MemRegion((HeapWord*)_rs.base(),
   911                  (HeapWord*)(_rs.base() + _rs.size())));
   913     assert(reserved()->start() == (HeapWord*) _rs.base(),
   914       err_msg("Reserved start was not set properly " PTR_FORMAT
   915         " != " PTR_FORMAT, reserved()->start(), _rs.base()));
   916     assert(reserved()->word_size() == _rs.size() / BytesPerWord,
   917       err_msg("Reserved size was not set properly " SIZE_FORMAT
   918         " != " SIZE_FORMAT, reserved()->word_size(),
   919         _rs.size() / BytesPerWord));
   920   }
   922   return result;
   923 }
   925 void VirtualSpaceNode::print_on(outputStream* st) const {
   926   size_t used = used_words_in_vs();
   927   size_t capacity = capacity_words_in_vs();
   928   VirtualSpace* vs = virtual_space();
   929   st->print_cr("   space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
   930            "[" PTR_FORMAT ", " PTR_FORMAT ", "
   931            PTR_FORMAT ", " PTR_FORMAT ")",
   932            vs, capacity / K,
   933            capacity == 0 ? 0 : used * 100 / capacity,
   934            bottom(), top(), end(),
   935            vs->high_boundary());
   936 }
   938 #ifdef ASSERT
   939 void VirtualSpaceNode::mangle() {
   940   size_t word_size = capacity_words_in_vs();
   941   Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
   942 }
   943 #endif // ASSERT
   945 // VirtualSpaceList methods
   946 // Space allocated from the VirtualSpace
   948 VirtualSpaceList::~VirtualSpaceList() {
   949   VirtualSpaceListIterator iter(virtual_space_list());
   950   while (iter.repeat()) {
   951     VirtualSpaceNode* vsl = iter.get_next();
   952     delete vsl;
   953   }
   954 }
   956 void VirtualSpaceList::inc_virtual_space_total(size_t v) {
   957   assert_lock_strong(SpaceManager::expand_lock());
   958   _virtual_space_total = _virtual_space_total + v;
   959 }
   960 void VirtualSpaceList::dec_virtual_space_total(size_t v) {
   961   assert_lock_strong(SpaceManager::expand_lock());
   962   _virtual_space_total = _virtual_space_total - v;
   963 }
   965 void VirtualSpaceList::inc_virtual_space_count() {
   966   assert_lock_strong(SpaceManager::expand_lock());
   967   _virtual_space_count++;
   968 }
   969 void VirtualSpaceList::dec_virtual_space_count() {
   970   assert_lock_strong(SpaceManager::expand_lock());
   971   _virtual_space_count--;
   972 }
   974 void ChunkManager::remove_chunk(Metachunk* chunk) {
   975   size_t word_size = chunk->word_size();
   976   ChunkIndex index = list_index(word_size);
   977   if (index != HumongousIndex) {
   978     free_chunks(index)->remove_chunk(chunk);
   979   } else {
   980     humongous_dictionary()->remove_chunk(chunk);
   981   }
   983   // Chunk is being removed from the chunks free list.
   984   dec_free_chunks_total(chunk->capacity_word_size());
   985 }
   987 // Walk the list of VirtualSpaceNodes and delete
   988 // nodes with a 0 container_count.  Remove Metachunks in
   989 // the node from their respective freelists.
   990 void VirtualSpaceList::purge() {
   991   assert_lock_strong(SpaceManager::expand_lock());
   992   // Don't use a VirtualSpaceListIterator because this
   993   // list is being changed and a straightforward use of an iterator is not safe.
   994   VirtualSpaceNode* purged_vsl = NULL;
   995   VirtualSpaceNode* prev_vsl = virtual_space_list();
   996   VirtualSpaceNode* next_vsl = prev_vsl;
   997   while (next_vsl != NULL) {
   998     VirtualSpaceNode* vsl = next_vsl;
   999     next_vsl = vsl->next();
  1000     // Don't free the current virtual space since it will likely
  1001     // be needed soon.
  1002     if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
  1003       // Unlink it from the list
  1004       if (prev_vsl == vsl) {
  1005         // This is the case of the current note being the first note.
  1006         assert(vsl == virtual_space_list(), "Expected to be the first note");
  1007         set_virtual_space_list(vsl->next());
  1008       } else {
  1009         prev_vsl->set_next(vsl->next());
  1012       vsl->purge(chunk_manager());
  1013       dec_virtual_space_total(vsl->reserved()->word_size());
  1014       dec_virtual_space_count();
  1015       purged_vsl = vsl;
  1016       delete vsl;
  1017     } else {
  1018       prev_vsl = vsl;
  1021 #ifdef ASSERT
  1022   if (purged_vsl != NULL) {
  1023   // List should be stable enough to use an iterator here.
  1024   VirtualSpaceListIterator iter(virtual_space_list());
  1025     while (iter.repeat()) {
  1026       VirtualSpaceNode* vsl = iter.get_next();
  1027       assert(vsl != purged_vsl, "Purge of vsl failed");
  1030 #endif
  1033 size_t VirtualSpaceList::used_words_sum() {
  1034   size_t allocated_by_vs = 0;
  1035   VirtualSpaceListIterator iter(virtual_space_list());
  1036   while (iter.repeat()) {
  1037     VirtualSpaceNode* vsl = iter.get_next();
  1038     // Sum used region [bottom, top) in each virtualspace
  1039     allocated_by_vs += vsl->used_words_in_vs();
  1041   assert(allocated_by_vs >= chunk_manager()->free_chunks_total(),
  1042     err_msg("Total in free chunks " SIZE_FORMAT
  1043             " greater than total from virtual_spaces " SIZE_FORMAT,
  1044             allocated_by_vs, chunk_manager()->free_chunks_total()));
  1045   size_t used =
  1046     allocated_by_vs - chunk_manager()->free_chunks_total();
  1047   return used;
  1050 // Space available in all MetadataVirtualspaces allocated
  1051 // for metadata.  This is the upper limit on the capacity
  1052 // of chunks allocated out of all the MetadataVirtualspaces.
  1053 size_t VirtualSpaceList::capacity_words_sum() {
  1054   size_t capacity = 0;
  1055   VirtualSpaceListIterator iter(virtual_space_list());
  1056   while (iter.repeat()) {
  1057     VirtualSpaceNode* vsl = iter.get_next();
  1058     capacity += vsl->capacity_words_in_vs();
  1060   return capacity;
  1063 VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
  1064                                    _is_class(false),
  1065                                    _virtual_space_list(NULL),
  1066                                    _current_virtual_space(NULL),
  1067                                    _virtual_space_total(0),
  1068                                    _virtual_space_count(0) {
  1069   MutexLockerEx cl(SpaceManager::expand_lock(),
  1070                    Mutex::_no_safepoint_check_flag);
  1071   bool initialization_succeeded = grow_vs(word_size);
  1073   _chunk_manager.free_chunks(SpecializedIndex)->set_size(SpecializedChunk);
  1074   _chunk_manager.free_chunks(SmallIndex)->set_size(SmallChunk);
  1075   _chunk_manager.free_chunks(MediumIndex)->set_size(MediumChunk);
  1076   assert(initialization_succeeded,
  1077     " VirtualSpaceList initialization should not fail");
  1080 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
  1081                                    _is_class(true),
  1082                                    _virtual_space_list(NULL),
  1083                                    _current_virtual_space(NULL),
  1084                                    _virtual_space_total(0),
  1085                                    _virtual_space_count(0) {
  1086   MutexLockerEx cl(SpaceManager::expand_lock(),
  1087                    Mutex::_no_safepoint_check_flag);
  1088   VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
  1089   bool succeeded = class_entry->initialize();
  1090   _chunk_manager.free_chunks(SpecializedIndex)->set_size(SpecializedChunk);
  1091   _chunk_manager.free_chunks(SmallIndex)->set_size(ClassSmallChunk);
  1092   _chunk_manager.free_chunks(MediumIndex)->set_size(ClassMediumChunk);
  1093   assert(succeeded, " VirtualSpaceList initialization should not fail");
  1094   link_vs(class_entry, rs.size()/BytesPerWord);
  1097 size_t VirtualSpaceList::free_bytes() {
  1098   return virtual_space_list()->free_words_in_vs() * BytesPerWord;
  1101 // Allocate another meta virtual space and add it to the list.
  1102 bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
  1103   assert_lock_strong(SpaceManager::expand_lock());
  1104   if (vs_word_size == 0) {
  1105     return false;
  1107   // Reserve the space
  1108   size_t vs_byte_size = vs_word_size * BytesPerWord;
  1109   assert(vs_byte_size % os::vm_page_size() == 0, "Not aligned");
  1111   // Allocate the meta virtual space and initialize it.
  1112   VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
  1113   if (!new_entry->initialize()) {
  1114     delete new_entry;
  1115     return false;
  1116   } else {
  1117     // ensure lock-free iteration sees fully initialized node
  1118     OrderAccess::storestore();
  1119     link_vs(new_entry, vs_word_size);
  1120     return true;
  1124 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size) {
  1125   if (virtual_space_list() == NULL) {
  1126       set_virtual_space_list(new_entry);
  1127   } else {
  1128     current_virtual_space()->set_next(new_entry);
  1130   set_current_virtual_space(new_entry);
  1131   inc_virtual_space_total(vs_word_size);
  1132   inc_virtual_space_count();
  1133 #ifdef ASSERT
  1134   new_entry->mangle();
  1135 #endif
  1136   if (TraceMetavirtualspaceAllocation && Verbose) {
  1137     VirtualSpaceNode* vsl = current_virtual_space();
  1138     vsl->print_on(tty);
  1142 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
  1143                                            size_t grow_chunks_by_words,
  1144                                            size_t medium_chunk_bunch) {
  1146   // Get a chunk from the chunk freelist
  1147   Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
  1149   if (next != NULL) {
  1150     next->container()->inc_container_count();
  1151   } else {
  1152     // Allocate a chunk out of the current virtual space.
  1153     next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
  1156   if (next == NULL) {
  1157     // Not enough room in current virtual space.  Try to commit
  1158     // more space.
  1159     size_t expand_vs_by_words = MAX2(medium_chunk_bunch,
  1160                                      grow_chunks_by_words);
  1161     size_t page_size_words = os::vm_page_size() / BytesPerWord;
  1162     size_t aligned_expand_vs_by_words = align_size_up(expand_vs_by_words,
  1163                                                         page_size_words);
  1164     bool vs_expanded =
  1165       current_virtual_space()->expand_by(aligned_expand_vs_by_words, false);
  1166     if (!vs_expanded) {
  1167       // Should the capacity of the metaspaces be expanded for
  1168       // this allocation?  If it's the virtual space for classes and is
  1169       // being used for CompressedHeaders, don't allocate a new virtualspace.
  1170       if (can_grow() && MetaspaceGC::should_expand(this, word_size)) {
  1171         // Get another virtual space.
  1172           size_t grow_vs_words =
  1173             MAX2((size_t)VirtualSpaceSize, aligned_expand_vs_by_words);
  1174         if (grow_vs(grow_vs_words)) {
  1175           // Got it.  It's on the list now.  Get a chunk from it.
  1176           next = current_virtual_space()->get_chunk_vs_with_expand(grow_chunks_by_words);
  1178       } else {
  1179         // Allocation will fail and induce a GC
  1180         if (TraceMetadataChunkAllocation && Verbose) {
  1181           gclog_or_tty->print_cr("VirtualSpaceList::get_new_chunk():"
  1182             " Fail instead of expand the metaspace");
  1185     } else {
  1186       // The virtual space expanded, get a new chunk
  1187       next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
  1188       assert(next != NULL, "Just expanded, should succeed");
  1192   assert(next == NULL || (next->next() == NULL && next->prev() == NULL),
  1193          "New chunk is still on some list");
  1194   return next;
  1197 Metachunk* VirtualSpaceList::get_initialization_chunk(size_t chunk_word_size,
  1198                                                       size_t chunk_bunch) {
  1199   // Get a chunk from the chunk freelist
  1200   Metachunk* new_chunk = get_new_chunk(chunk_word_size,
  1201                                        chunk_word_size,
  1202                                        chunk_bunch);
  1203   return new_chunk;
  1206 void VirtualSpaceList::print_on(outputStream* st) const {
  1207   if (TraceMetadataChunkAllocation && Verbose) {
  1208     VirtualSpaceListIterator iter(virtual_space_list());
  1209     while (iter.repeat()) {
  1210       VirtualSpaceNode* node = iter.get_next();
  1211       node->print_on(st);
  1216 bool VirtualSpaceList::contains(const void *ptr) {
  1217   VirtualSpaceNode* list = virtual_space_list();
  1218   VirtualSpaceListIterator iter(list);
  1219   while (iter.repeat()) {
  1220     VirtualSpaceNode* node = iter.get_next();
  1221     if (node->reserved()->contains(ptr)) {
  1222       return true;
  1225   return false;
  1229 // MetaspaceGC methods
  1231 // VM_CollectForMetadataAllocation is the vm operation used to GC.
  1232 // Within the VM operation after the GC the attempt to allocate the metadata
  1233 // should succeed.  If the GC did not free enough space for the metaspace
  1234 // allocation, the HWM is increased so that another virtualspace will be
  1235 // allocated for the metadata.  With perm gen the increase in the perm
  1236 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion.  The
  1237 // metaspace policy uses those as the small and large steps for the HWM.
  1238 //
  1239 // After the GC the compute_new_size() for MetaspaceGC is called to
  1240 // resize the capacity of the metaspaces.  The current implementation
  1241 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
  1242 // to resize the Java heap by some GC's.  New flags can be implemented
  1243 // if really needed.  MinMetaspaceFreeRatio is used to calculate how much
  1244 // free space is desirable in the metaspace capacity to decide how much
  1245 // to increase the HWM.  MaxMetaspaceFreeRatio is used to decide how much
  1246 // free space is desirable in the metaspace capacity before decreasing
  1247 // the HWM.
  1249 // Calculate the amount to increase the high water mark (HWM).
  1250 // Increase by a minimum amount (MinMetaspaceExpansion) so that
  1251 // another expansion is not requested too soon.  If that is not
  1252 // enough to satisfy the allocation (i.e. big enough for a word_size
  1253 // allocation), increase by MaxMetaspaceExpansion.  If that is still
  1254 // not enough, expand by the size of the allocation (word_size) plus
  1255 // some.
  1256 size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
  1257   size_t before_inc = MetaspaceGC::capacity_until_GC();
  1258   size_t min_delta_words = MinMetaspaceExpansion / BytesPerWord;
  1259   size_t max_delta_words = MaxMetaspaceExpansion / BytesPerWord;
  1260   size_t page_size_words = os::vm_page_size() / BytesPerWord;
  1261   size_t size_delta_words = align_size_up(word_size, page_size_words);
  1262   size_t delta_words = MAX2(size_delta_words, min_delta_words);
  1263   if (delta_words > min_delta_words) {
  1264     // Don't want to hit the high water mark on the next
  1265     // allocation so make the delta greater than just enough
  1266     // for this allocation.
  1267     delta_words = MAX2(delta_words, max_delta_words);
  1268     if (delta_words > max_delta_words) {
  1269       // This allocation is large but the next ones are probably not
  1270       // so increase by the minimum.
  1271       delta_words = delta_words + min_delta_words;
  1274   return delta_words;
  1277 bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
  1279   size_t committed_capacity_bytes = MetaspaceAux::allocated_capacity_bytes();
  1280   // If the user wants a limit, impose one.
  1281   size_t max_metaspace_size_bytes = MaxMetaspaceSize;
  1282   size_t metaspace_size_bytes = MetaspaceSize;
  1283   if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
  1284       MetaspaceAux::reserved_in_bytes() >= MaxMetaspaceSize) {
  1285     return false;
  1288   // Class virtual space should always be expanded.  Call GC for the other
  1289   // metadata virtual space.
  1290   if (vsl == Metaspace::class_space_list()) return true;
  1292   // If this is part of an allocation after a GC, expand
  1293   // unconditionally.
  1294   if (MetaspaceGC::expand_after_GC()) {
  1295     return true;
  1300   // If the capacity is below the minimum capacity, allow the
  1301   // expansion.  Also set the high-water-mark (capacity_until_GC)
  1302   // to that minimum capacity so that a GC will not be induced
  1303   // until that minimum capacity is exceeded.
  1304   if (committed_capacity_bytes < metaspace_size_bytes ||
  1305       capacity_until_GC() == 0) {
  1306     set_capacity_until_GC(metaspace_size_bytes);
  1307     return true;
  1308   } else {
  1309     if (committed_capacity_bytes < capacity_until_GC()) {
  1310       return true;
  1311     } else {
  1312       if (TraceMetadataChunkAllocation && Verbose) {
  1313         gclog_or_tty->print_cr("  allocation request size " SIZE_FORMAT
  1314                         "  capacity_until_GC " SIZE_FORMAT
  1315                         "  allocated_capacity_bytes " SIZE_FORMAT,
  1316                         word_size,
  1317                         capacity_until_GC(),
  1318                         MetaspaceAux::allocated_capacity_bytes());
  1320       return false;
  1327 void MetaspaceGC::compute_new_size() {
  1328   assert(_shrink_factor <= 100, "invalid shrink factor");
  1329   uint current_shrink_factor = _shrink_factor;
  1330   _shrink_factor = 0;
  1332   // Until a faster way of calculating the "used" quantity is implemented,
  1333   // use "capacity".
  1334   const size_t used_after_gc = MetaspaceAux::allocated_capacity_bytes();
  1335   const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
  1337   const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
  1338   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
  1340   const double min_tmp = used_after_gc / maximum_used_percentage;
  1341   size_t minimum_desired_capacity =
  1342     (size_t)MIN2(min_tmp, double(max_uintx));
  1343   // Don't shrink less than the initial generation size
  1344   minimum_desired_capacity = MAX2(minimum_desired_capacity,
  1345                                   MetaspaceSize);
  1347   if (PrintGCDetails && Verbose) {
  1348     gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
  1349     gclog_or_tty->print_cr("  "
  1350                   "  minimum_free_percentage: %6.2f"
  1351                   "  maximum_used_percentage: %6.2f",
  1352                   minimum_free_percentage,
  1353                   maximum_used_percentage);
  1354     gclog_or_tty->print_cr("  "
  1355                   "   used_after_gc       : %6.1fKB",
  1356                   used_after_gc / (double) K);
  1360   size_t shrink_bytes = 0;
  1361   if (capacity_until_GC < minimum_desired_capacity) {
  1362     // If we have less capacity below the metaspace HWM, then
  1363     // increment the HWM.
  1364     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
  1365     // Don't expand unless it's significant
  1366     if (expand_bytes >= MinMetaspaceExpansion) {
  1367       MetaspaceGC::set_capacity_until_GC(capacity_until_GC + expand_bytes);
  1369     if (PrintGCDetails && Verbose) {
  1370       size_t new_capacity_until_GC = capacity_until_GC;
  1371       gclog_or_tty->print_cr("    expanding:"
  1372                     "  minimum_desired_capacity: %6.1fKB"
  1373                     "  expand_bytes: %6.1fKB"
  1374                     "  MinMetaspaceExpansion: %6.1fKB"
  1375                     "  new metaspace HWM:  %6.1fKB",
  1376                     minimum_desired_capacity / (double) K,
  1377                     expand_bytes / (double) K,
  1378                     MinMetaspaceExpansion / (double) K,
  1379                     new_capacity_until_GC / (double) K);
  1381     return;
  1384   // No expansion, now see if we want to shrink
  1385   // We would never want to shrink more than this
  1386   size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity;
  1387   assert(max_shrink_bytes >= 0, err_msg("max_shrink_bytes " SIZE_FORMAT,
  1388     max_shrink_bytes));
  1390   // Should shrinking be considered?
  1391   if (MaxMetaspaceFreeRatio < 100) {
  1392     const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0;
  1393     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
  1394     const double max_tmp = used_after_gc / minimum_used_percentage;
  1395     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
  1396     maximum_desired_capacity = MAX2(maximum_desired_capacity,
  1397                                     MetaspaceSize);
  1398     if (PrintGCDetails && Verbose) {
  1399       gclog_or_tty->print_cr("  "
  1400                              "  maximum_free_percentage: %6.2f"
  1401                              "  minimum_used_percentage: %6.2f",
  1402                              maximum_free_percentage,
  1403                              minimum_used_percentage);
  1404       gclog_or_tty->print_cr("  "
  1405                              "  minimum_desired_capacity: %6.1fKB"
  1406                              "  maximum_desired_capacity: %6.1fKB",
  1407                              minimum_desired_capacity / (double) K,
  1408                              maximum_desired_capacity / (double) K);
  1411     assert(minimum_desired_capacity <= maximum_desired_capacity,
  1412            "sanity check");
  1414     if (capacity_until_GC > maximum_desired_capacity) {
  1415       // Capacity too large, compute shrinking size
  1416       shrink_bytes = capacity_until_GC - maximum_desired_capacity;
  1417       // We don't want shrink all the way back to initSize if people call
  1418       // System.gc(), because some programs do that between "phases" and then
  1419       // we'd just have to grow the heap up again for the next phase.  So we
  1420       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
  1421       // on the third call, and 100% by the fourth call.  But if we recompute
  1422       // size without shrinking, it goes back to 0%.
  1423       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
  1424       assert(shrink_bytes <= max_shrink_bytes,
  1425         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
  1426           shrink_bytes, max_shrink_bytes));
  1427       if (current_shrink_factor == 0) {
  1428         _shrink_factor = 10;
  1429       } else {
  1430         _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
  1432       if (PrintGCDetails && Verbose) {
  1433         gclog_or_tty->print_cr("  "
  1434                       "  shrinking:"
  1435                       "  initSize: %.1fK"
  1436                       "  maximum_desired_capacity: %.1fK",
  1437                       MetaspaceSize / (double) K,
  1438                       maximum_desired_capacity / (double) K);
  1439         gclog_or_tty->print_cr("  "
  1440                       "  shrink_bytes: %.1fK"
  1441                       "  current_shrink_factor: %d"
  1442                       "  new shrink factor: %d"
  1443                       "  MinMetaspaceExpansion: %.1fK",
  1444                       shrink_bytes / (double) K,
  1445                       current_shrink_factor,
  1446                       _shrink_factor,
  1447                       MinMetaspaceExpansion / (double) K);
  1452   // Don't shrink unless it's significant
  1453   if (shrink_bytes >= MinMetaspaceExpansion &&
  1454       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
  1455     MetaspaceGC::set_capacity_until_GC(capacity_until_GC - shrink_bytes);
  1459 // Metadebug methods
  1461 void Metadebug::deallocate_chunk_a_lot(SpaceManager* sm,
  1462                                        size_t chunk_word_size){
  1463 #ifdef ASSERT
  1464   VirtualSpaceList* vsl = sm->vs_list();
  1465   if (MetaDataDeallocateALot &&
  1466       Metadebug::deallocate_chunk_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
  1467     Metadebug::reset_deallocate_chunk_a_lot_count();
  1468     for (uint i = 0; i < metadata_deallocate_a_lock_chunk; i++) {
  1469       Metachunk* dummy_chunk = vsl->current_virtual_space()->take_from_committed(chunk_word_size);
  1470       if (dummy_chunk == NULL) {
  1471         break;
  1473       vsl->chunk_manager()->chunk_freelist_deallocate(dummy_chunk);
  1475       if (TraceMetadataChunkAllocation && Verbose) {
  1476         gclog_or_tty->print("Metadebug::deallocate_chunk_a_lot: %d) ",
  1477                                sm->sum_count_in_chunks_in_use());
  1478         dummy_chunk->print_on(gclog_or_tty);
  1479         gclog_or_tty->print_cr("  Free chunks total %d  count %d",
  1480                                vsl->chunk_manager()->free_chunks_total(),
  1481                                vsl->chunk_manager()->free_chunks_count());
  1484   } else {
  1485     Metadebug::inc_deallocate_chunk_a_lot_count();
  1487 #endif
  1490 void Metadebug::deallocate_block_a_lot(SpaceManager* sm,
  1491                                        size_t raw_word_size){
  1492 #ifdef ASSERT
  1493   if (MetaDataDeallocateALot &&
  1494         Metadebug::deallocate_block_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
  1495     Metadebug::set_deallocate_block_a_lot_count(0);
  1496     for (uint i = 0; i < metadata_deallocate_a_lot_block; i++) {
  1497       MetaWord* dummy_block = sm->allocate_work(raw_word_size);
  1498       if (dummy_block == 0) {
  1499         break;
  1501       sm->deallocate(dummy_block, raw_word_size);
  1503   } else {
  1504     Metadebug::inc_deallocate_block_a_lot_count();
  1506 #endif
  1509 void Metadebug::init_allocation_fail_alot_count() {
  1510   if (MetadataAllocationFailALot) {
  1511     _allocation_fail_alot_count =
  1512       1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
  1516 #ifdef ASSERT
  1517 bool Metadebug::test_metadata_failure() {
  1518   if (MetadataAllocationFailALot &&
  1519       Threads::is_vm_complete()) {
  1520     if (_allocation_fail_alot_count > 0) {
  1521       _allocation_fail_alot_count--;
  1522     } else {
  1523       if (TraceMetadataChunkAllocation && Verbose) {
  1524         gclog_or_tty->print_cr("Metadata allocation failing for "
  1525                                "MetadataAllocationFailALot");
  1527       init_allocation_fail_alot_count();
  1528       return true;
  1531   return false;
  1533 #endif
  1535 // ChunkManager methods
  1537 // Verification of _free_chunks_total and _free_chunks_count does not
  1538 // work with the CMS collector because its use of additional locks
  1539 // complicate the mutex deadlock detection but it can still be useful
  1540 // for detecting errors in the chunk accounting with other collectors.
  1542 size_t ChunkManager::free_chunks_total() {
  1543 #ifdef ASSERT
  1544   if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
  1545     MutexLockerEx cl(SpaceManager::expand_lock(),
  1546                      Mutex::_no_safepoint_check_flag);
  1547     slow_locked_verify_free_chunks_total();
  1549 #endif
  1550   return _free_chunks_total;
  1553 size_t ChunkManager::free_chunks_total_in_bytes() {
  1554   return free_chunks_total() * BytesPerWord;
  1557 size_t ChunkManager::free_chunks_count() {
  1558 #ifdef ASSERT
  1559   if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
  1560     MutexLockerEx cl(SpaceManager::expand_lock(),
  1561                      Mutex::_no_safepoint_check_flag);
  1562     // This lock is only needed in debug because the verification
  1563     // of the _free_chunks_totals walks the list of free chunks
  1564     slow_locked_verify_free_chunks_count();
  1566 #endif
  1567   return _free_chunks_count;
  1570 void ChunkManager::locked_verify_free_chunks_total() {
  1571   assert_lock_strong(SpaceManager::expand_lock());
  1572   assert(sum_free_chunks() == _free_chunks_total,
  1573     err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
  1574            " same as sum " SIZE_FORMAT, _free_chunks_total,
  1575            sum_free_chunks()));
  1578 void ChunkManager::verify_free_chunks_total() {
  1579   MutexLockerEx cl(SpaceManager::expand_lock(),
  1580                      Mutex::_no_safepoint_check_flag);
  1581   locked_verify_free_chunks_total();
  1584 void ChunkManager::locked_verify_free_chunks_count() {
  1585   assert_lock_strong(SpaceManager::expand_lock());
  1586   assert(sum_free_chunks_count() == _free_chunks_count,
  1587     err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
  1588            " same as sum " SIZE_FORMAT, _free_chunks_count,
  1589            sum_free_chunks_count()));
  1592 void ChunkManager::verify_free_chunks_count() {
  1593 #ifdef ASSERT
  1594   MutexLockerEx cl(SpaceManager::expand_lock(),
  1595                      Mutex::_no_safepoint_check_flag);
  1596   locked_verify_free_chunks_count();
  1597 #endif
  1600 void ChunkManager::verify() {
  1601   MutexLockerEx cl(SpaceManager::expand_lock(),
  1602                      Mutex::_no_safepoint_check_flag);
  1603   locked_verify();
  1606 void ChunkManager::locked_verify() {
  1607   locked_verify_free_chunks_count();
  1608   locked_verify_free_chunks_total();
  1611 void ChunkManager::locked_print_free_chunks(outputStream* st) {
  1612   assert_lock_strong(SpaceManager::expand_lock());
  1613   st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
  1614                 _free_chunks_total, _free_chunks_count);
  1617 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
  1618   assert_lock_strong(SpaceManager::expand_lock());
  1619   st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
  1620                 sum_free_chunks(), sum_free_chunks_count());
  1622 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
  1623   return &_free_chunks[index];
  1626 // These methods that sum the free chunk lists are used in printing
  1627 // methods that are used in product builds.
  1628 size_t ChunkManager::sum_free_chunks() {
  1629   assert_lock_strong(SpaceManager::expand_lock());
  1630   size_t result = 0;
  1631   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
  1632     ChunkList* list = free_chunks(i);
  1634     if (list == NULL) {
  1635       continue;
  1638     result = result + list->count() * list->size();
  1640   result = result + humongous_dictionary()->total_size();
  1641   return result;
  1644 size_t ChunkManager::sum_free_chunks_count() {
  1645   assert_lock_strong(SpaceManager::expand_lock());
  1646   size_t count = 0;
  1647   for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
  1648     ChunkList* list = free_chunks(i);
  1649     if (list == NULL) {
  1650       continue;
  1652     count = count + list->count();
  1654   count = count + humongous_dictionary()->total_free_blocks();
  1655   return count;
  1658 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
  1659   ChunkIndex index = list_index(word_size);
  1660   assert(index < HumongousIndex, "No humongous list");
  1661   return free_chunks(index);
  1664 void ChunkManager::free_chunks_put(Metachunk* chunk) {
  1665   assert_lock_strong(SpaceManager::expand_lock());
  1666   ChunkList* free_list = find_free_chunks_list(chunk->word_size());
  1667   chunk->set_next(free_list->head());
  1668   free_list->set_head(chunk);
  1669   // chunk is being returned to the chunk free list
  1670   inc_free_chunks_total(chunk->capacity_word_size());
  1671   slow_locked_verify();
  1674 void ChunkManager::chunk_freelist_deallocate(Metachunk* chunk) {
  1675   // The deallocation of a chunk originates in the freelist
  1676   // manangement code for a Metaspace and does not hold the
  1677   // lock.
  1678   assert(chunk != NULL, "Deallocating NULL");
  1679   assert_lock_strong(SpaceManager::expand_lock());
  1680   slow_locked_verify();
  1681   if (TraceMetadataChunkAllocation) {
  1682     tty->print_cr("ChunkManager::chunk_freelist_deallocate: chunk "
  1683                   PTR_FORMAT "  size " SIZE_FORMAT,
  1684                   chunk, chunk->word_size());
  1686   free_chunks_put(chunk);
  1689 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
  1690   assert_lock_strong(SpaceManager::expand_lock());
  1692   slow_locked_verify();
  1694   Metachunk* chunk = NULL;
  1695   if (list_index(word_size) != HumongousIndex) {
  1696     ChunkList* free_list = find_free_chunks_list(word_size);
  1697     assert(free_list != NULL, "Sanity check");
  1699     chunk = free_list->head();
  1700     debug_only(Metachunk* debug_head = chunk;)
  1702     if (chunk == NULL) {
  1703       return NULL;
  1706     // Remove the chunk as the head of the list.
  1707     free_list->remove_chunk(chunk);
  1709     // Chunk is being removed from the chunks free list.
  1710     dec_free_chunks_total(chunk->capacity_word_size());
  1712     if (TraceMetadataChunkAllocation && Verbose) {
  1713       tty->print_cr("ChunkManager::free_chunks_get: free_list "
  1714                     PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
  1715                     free_list, chunk, chunk->word_size());
  1717   } else {
  1718     chunk = humongous_dictionary()->get_chunk(
  1719       word_size,
  1720       FreeBlockDictionary<Metachunk>::atLeast);
  1722     if (chunk != NULL) {
  1723       if (TraceMetadataHumongousAllocation) {
  1724         size_t waste = chunk->word_size() - word_size;
  1725         tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
  1726                       " for requested size " SIZE_FORMAT
  1727                       " waste " SIZE_FORMAT,
  1728                       chunk->word_size(), word_size, waste);
  1730       // Chunk is being removed from the chunks free list.
  1731       dec_free_chunks_total(chunk->capacity_word_size());
  1732     } else {
  1733       return NULL;
  1737   // Remove it from the links to this freelist
  1738   chunk->set_next(NULL);
  1739   chunk->set_prev(NULL);
  1740 #ifdef ASSERT
  1741   // Chunk is no longer on any freelist. Setting to false make container_count_slow()
  1742   // work.
  1743   chunk->set_is_free(false);
  1744 #endif
  1745   slow_locked_verify();
  1746   return chunk;
  1749 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
  1750   assert_lock_strong(SpaceManager::expand_lock());
  1751   slow_locked_verify();
  1753   // Take from the beginning of the list
  1754   Metachunk* chunk = free_chunks_get(word_size);
  1755   if (chunk == NULL) {
  1756     return NULL;
  1759   assert((word_size <= chunk->word_size()) ||
  1760          list_index(chunk->word_size() == HumongousIndex),
  1761          "Non-humongous variable sized chunk");
  1762   if (TraceMetadataChunkAllocation) {
  1763     size_t list_count;
  1764     if (list_index(word_size) < HumongousIndex) {
  1765       ChunkList* list = find_free_chunks_list(word_size);
  1766       list_count = list->count();
  1767     } else {
  1768       list_count = humongous_dictionary()->total_count();
  1770     tty->print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk "
  1771                PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
  1772                this, chunk, chunk->word_size(), list_count);
  1773     locked_print_free_chunks(tty);
  1776   return chunk;
  1779 void ChunkManager::print_on(outputStream* out) {
  1780   if (PrintFLSStatistics != 0) {
  1781     humongous_dictionary()->report_statistics();
  1785 // SpaceManager methods
  1787 void SpaceManager::get_initial_chunk_sizes(Metaspace::MetaspaceType type,
  1788                                            size_t* chunk_word_size,
  1789                                            size_t* class_chunk_word_size) {
  1790   switch (type) {
  1791   case Metaspace::BootMetaspaceType:
  1792     *chunk_word_size = Metaspace::first_chunk_word_size();
  1793     *class_chunk_word_size = Metaspace::first_class_chunk_word_size();
  1794     break;
  1795   case Metaspace::ROMetaspaceType:
  1796     *chunk_word_size = SharedReadOnlySize / wordSize;
  1797     *class_chunk_word_size = ClassSpecializedChunk;
  1798     break;
  1799   case Metaspace::ReadWriteMetaspaceType:
  1800     *chunk_word_size = SharedReadWriteSize / wordSize;
  1801     *class_chunk_word_size = ClassSpecializedChunk;
  1802     break;
  1803   case Metaspace::AnonymousMetaspaceType:
  1804   case Metaspace::ReflectionMetaspaceType:
  1805     *chunk_word_size = SpecializedChunk;
  1806     *class_chunk_word_size = ClassSpecializedChunk;
  1807     break;
  1808   default:
  1809     *chunk_word_size = SmallChunk;
  1810     *class_chunk_word_size = ClassSmallChunk;
  1811     break;
  1813   assert(*chunk_word_size != 0 && *class_chunk_word_size != 0,
  1814     err_msg("Initial chunks sizes bad: data  " SIZE_FORMAT
  1815             " class " SIZE_FORMAT,
  1816             *chunk_word_size, *class_chunk_word_size));
  1819 size_t SpaceManager::sum_free_in_chunks_in_use() const {
  1820   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
  1821   size_t free = 0;
  1822   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1823     Metachunk* chunk = chunks_in_use(i);
  1824     while (chunk != NULL) {
  1825       free += chunk->free_word_size();
  1826       chunk = chunk->next();
  1829   return free;
  1832 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
  1833   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
  1834   size_t result = 0;
  1835   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1836    result += sum_waste_in_chunks_in_use(i);
  1839   return result;
  1842 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
  1843   size_t result = 0;
  1844   Metachunk* chunk = chunks_in_use(index);
  1845   // Count the free space in all the chunk but not the
  1846   // current chunk from which allocations are still being done.
  1847   if (chunk != NULL) {
  1848     Metachunk* prev = chunk;
  1849     while (chunk != NULL && chunk != current_chunk()) {
  1850       result += chunk->free_word_size();
  1851       prev = chunk;
  1852       chunk = chunk->next();
  1855   return result;
  1858 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
  1859   // For CMS use "allocated_chunks_words()" which does not need the
  1860   // Metaspace lock.  For the other collectors sum over the
  1861   // lists.  Use both methods as a check that "allocated_chunks_words()"
  1862   // is correct.  That is, sum_capacity_in_chunks() is too expensive
  1863   // to use in the product and allocated_chunks_words() should be used
  1864   // but allow for  checking that allocated_chunks_words() returns the same
  1865   // value as sum_capacity_in_chunks_in_use() which is the definitive
  1866   // answer.
  1867   if (UseConcMarkSweepGC) {
  1868     return allocated_chunks_words();
  1869   } else {
  1870     MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
  1871     size_t sum = 0;
  1872     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1873       Metachunk* chunk = chunks_in_use(i);
  1874       while (chunk != NULL) {
  1875         sum += chunk->capacity_word_size();
  1876         chunk = chunk->next();
  1879   return sum;
  1883 size_t SpaceManager::sum_count_in_chunks_in_use() {
  1884   size_t count = 0;
  1885   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1886     count = count + sum_count_in_chunks_in_use(i);
  1889   return count;
  1892 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
  1893   size_t count = 0;
  1894   Metachunk* chunk = chunks_in_use(i);
  1895   while (chunk != NULL) {
  1896     count++;
  1897     chunk = chunk->next();
  1899   return count;
  1903 size_t SpaceManager::sum_used_in_chunks_in_use() const {
  1904   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
  1905   size_t used = 0;
  1906   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1907     Metachunk* chunk = chunks_in_use(i);
  1908     while (chunk != NULL) {
  1909       used += chunk->used_word_size();
  1910       chunk = chunk->next();
  1913   return used;
  1916 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
  1918   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  1919     Metachunk* chunk = chunks_in_use(i);
  1920     st->print("SpaceManager: %s " PTR_FORMAT,
  1921                  chunk_size_name(i), chunk);
  1922     if (chunk != NULL) {
  1923       st->print_cr(" free " SIZE_FORMAT,
  1924                    chunk->free_word_size());
  1925     } else {
  1926       st->print_cr("");
  1930   vs_list()->chunk_manager()->locked_print_free_chunks(st);
  1931   vs_list()->chunk_manager()->locked_print_sum_free_chunks(st);
  1934 size_t SpaceManager::calc_chunk_size(size_t word_size) {
  1936   // Decide between a small chunk and a medium chunk.  Up to
  1937   // _small_chunk_limit small chunks can be allocated but
  1938   // once a medium chunk has been allocated, no more small
  1939   // chunks will be allocated.
  1940   size_t chunk_word_size;
  1941   if (chunks_in_use(MediumIndex) == NULL &&
  1942       (!has_small_chunk_limit() ||
  1943        sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit)) {
  1944     chunk_word_size = (size_t) small_chunk_size();
  1945     if (word_size + Metachunk::overhead() > small_chunk_size()) {
  1946       chunk_word_size = medium_chunk_size();
  1948   } else {
  1949     chunk_word_size = medium_chunk_size();
  1952   // Might still need a humongous chunk.  Enforce an
  1953   // eight word granularity to facilitate reuse (some
  1954   // wastage but better chance of reuse).
  1955   size_t if_humongous_sized_chunk =
  1956     align_size_up(word_size + Metachunk::overhead(),
  1957                   HumongousChunkGranularity);
  1958   chunk_word_size =
  1959     MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
  1961   assert(!SpaceManager::is_humongous(word_size) ||
  1962          chunk_word_size == if_humongous_sized_chunk,
  1963          err_msg("Size calculation is wrong, word_size " SIZE_FORMAT
  1964                  " chunk_word_size " SIZE_FORMAT,
  1965                  word_size, chunk_word_size));
  1966   if (TraceMetadataHumongousAllocation &&
  1967       SpaceManager::is_humongous(word_size)) {
  1968     gclog_or_tty->print_cr("Metadata humongous allocation:");
  1969     gclog_or_tty->print_cr("  word_size " PTR_FORMAT, word_size);
  1970     gclog_or_tty->print_cr("  chunk_word_size " PTR_FORMAT,
  1971                            chunk_word_size);
  1972     gclog_or_tty->print_cr("    chunk overhead " PTR_FORMAT,
  1973                            Metachunk::overhead());
  1975   return chunk_word_size;
  1978 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
  1979   assert(vs_list()->current_virtual_space() != NULL,
  1980          "Should have been set");
  1981   assert(current_chunk() == NULL ||
  1982          current_chunk()->allocate(word_size) == NULL,
  1983          "Don't need to expand");
  1984   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
  1986   if (TraceMetadataChunkAllocation && Verbose) {
  1987     size_t words_left = 0;
  1988     size_t words_used = 0;
  1989     if (current_chunk() != NULL) {
  1990       words_left = current_chunk()->free_word_size();
  1991       words_used = current_chunk()->used_word_size();
  1993     gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
  1994                            " words " SIZE_FORMAT " words used " SIZE_FORMAT
  1995                            " words left",
  1996                             word_size, words_used, words_left);
  1999   // Get another chunk out of the virtual space
  2000   size_t grow_chunks_by_words = calc_chunk_size(word_size);
  2001   Metachunk* next = get_new_chunk(word_size, grow_chunks_by_words);
  2003   // If a chunk was available, add it to the in-use chunk list
  2004   // and do an allocation from it.
  2005   if (next != NULL) {
  2006     Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
  2007     // Add to this manager's list of chunks in use.
  2008     add_chunk(next, false);
  2009     return next->allocate(word_size);
  2011   return NULL;
  2014 void SpaceManager::print_on(outputStream* st) const {
  2016   for (ChunkIndex i = ZeroIndex;
  2017        i < NumberOfInUseLists ;
  2018        i = next_chunk_index(i) ) {
  2019     st->print_cr("  chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
  2020                  chunks_in_use(i),
  2021                  chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
  2023   st->print_cr("    waste:  Small " SIZE_FORMAT " Medium " SIZE_FORMAT
  2024                " Humongous " SIZE_FORMAT,
  2025                sum_waste_in_chunks_in_use(SmallIndex),
  2026                sum_waste_in_chunks_in_use(MediumIndex),
  2027                sum_waste_in_chunks_in_use(HumongousIndex));
  2028   // block free lists
  2029   if (block_freelists() != NULL) {
  2030     st->print_cr("total in block free lists " SIZE_FORMAT,
  2031       block_freelists()->total_size());
  2035 SpaceManager::SpaceManager(Mutex* lock,
  2036                            VirtualSpaceList* vs_list) :
  2037   _vs_list(vs_list),
  2038   _allocated_blocks_words(0),
  2039   _allocated_chunks_words(0),
  2040   _allocated_chunks_count(0),
  2041   _lock(lock)
  2043   initialize();
  2046 void SpaceManager::inc_size_metrics(size_t words) {
  2047   assert_lock_strong(SpaceManager::expand_lock());
  2048   // Total of allocated Metachunks and allocated Metachunks count
  2049   // for each SpaceManager
  2050   _allocated_chunks_words = _allocated_chunks_words + words;
  2051   _allocated_chunks_count++;
  2052   // Global total of capacity in allocated Metachunks
  2053   MetaspaceAux::inc_capacity(words);
  2054   // Global total of allocated Metablocks.
  2055   // used_words_slow() includes the overhead in each
  2056   // Metachunk so include it in the used when the
  2057   // Metachunk is first added (so only added once per
  2058   // Metachunk).
  2059   MetaspaceAux::inc_used(Metachunk::overhead());
  2062 void SpaceManager::inc_used_metrics(size_t words) {
  2063   // Add to the per SpaceManager total
  2064   Atomic::add_ptr(words, &_allocated_blocks_words);
  2065   // Add to the global total
  2066   MetaspaceAux::inc_used(words);
  2069 void SpaceManager::dec_total_from_size_metrics() {
  2070   MetaspaceAux::dec_capacity(allocated_chunks_words());
  2071   MetaspaceAux::dec_used(allocated_blocks_words());
  2072   // Also deduct the overhead per Metachunk
  2073   MetaspaceAux::dec_used(allocated_chunks_count() * Metachunk::overhead());
  2076 void SpaceManager::initialize() {
  2077   Metadebug::init_allocation_fail_alot_count();
  2078   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  2079     _chunks_in_use[i] = NULL;
  2081   _current_chunk = NULL;
  2082   if (TraceMetadataChunkAllocation && Verbose) {
  2083     gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
  2087 void ChunkManager::return_chunks(ChunkIndex index, Metachunk* chunks) {
  2088   if (chunks == NULL) {
  2089     return;
  2091   ChunkList* list = free_chunks(index);
  2092   assert(list->size() == chunks->word_size(), "Mismatch in chunk sizes");
  2093   assert_lock_strong(SpaceManager::expand_lock());
  2094   Metachunk* cur = chunks;
  2096   // This returns chunks one at a time.  If a new
  2097   // class List can be created that is a base class
  2098   // of FreeList then something like FreeList::prepend()
  2099   // can be used in place of this loop
  2100   while (cur != NULL) {
  2101     assert(cur->container() != NULL, "Container should have been set");
  2102     cur->container()->dec_container_count();
  2103     // Capture the next link before it is changed
  2104     // by the call to return_chunk_at_head();
  2105     Metachunk* next = cur->next();
  2106     cur->set_is_free(true);
  2107     list->return_chunk_at_head(cur);
  2108     cur = next;
  2112 SpaceManager::~SpaceManager() {
  2113   // This call this->_lock which can't be done while holding expand_lock()
  2114   assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(),
  2115     err_msg("sum_capacity_in_chunks_in_use() " SIZE_FORMAT
  2116             " allocated_chunks_words() " SIZE_FORMAT,
  2117             sum_capacity_in_chunks_in_use(), allocated_chunks_words()));
  2119   MutexLockerEx fcl(SpaceManager::expand_lock(),
  2120                     Mutex::_no_safepoint_check_flag);
  2122   ChunkManager* chunk_manager = vs_list()->chunk_manager();
  2124   chunk_manager->slow_locked_verify();
  2126   dec_total_from_size_metrics();
  2128   if (TraceMetadataChunkAllocation && Verbose) {
  2129     gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
  2130     locked_print_chunks_in_use_on(gclog_or_tty);
  2133   // Do not mangle freed Metachunks.  The chunk size inside Metachunks
  2134   // is during the freeing of a VirtualSpaceNodes.
  2136   // Have to update before the chunks_in_use lists are emptied
  2137   // below.
  2138   chunk_manager->inc_free_chunks_total(allocated_chunks_words(),
  2139                                        sum_count_in_chunks_in_use());
  2141   // Add all the chunks in use by this space manager
  2142   // to the global list of free chunks.
  2144   // Follow each list of chunks-in-use and add them to the
  2145   // free lists.  Each list is NULL terminated.
  2147   for (ChunkIndex i = ZeroIndex; i < HumongousIndex; i = next_chunk_index(i)) {
  2148     if (TraceMetadataChunkAllocation && Verbose) {
  2149       gclog_or_tty->print_cr("returned %d %s chunks to freelist",
  2150                              sum_count_in_chunks_in_use(i),
  2151                              chunk_size_name(i));
  2153     Metachunk* chunks = chunks_in_use(i);
  2154     chunk_manager->return_chunks(i, chunks);
  2155     set_chunks_in_use(i, NULL);
  2156     if (TraceMetadataChunkAllocation && Verbose) {
  2157       gclog_or_tty->print_cr("updated freelist count %d %s",
  2158                              chunk_manager->free_chunks(i)->count(),
  2159                              chunk_size_name(i));
  2161     assert(i != HumongousIndex, "Humongous chunks are handled explicitly later");
  2164   // The medium chunk case may be optimized by passing the head and
  2165   // tail of the medium chunk list to add_at_head().  The tail is often
  2166   // the current chunk but there are probably exceptions.
  2168   // Humongous chunks
  2169   if (TraceMetadataChunkAllocation && Verbose) {
  2170     gclog_or_tty->print_cr("returned %d %s humongous chunks to dictionary",
  2171                             sum_count_in_chunks_in_use(HumongousIndex),
  2172                             chunk_size_name(HumongousIndex));
  2173     gclog_or_tty->print("Humongous chunk dictionary: ");
  2175   // Humongous chunks are never the current chunk.
  2176   Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
  2178   while (humongous_chunks != NULL) {
  2179 #ifdef ASSERT
  2180     humongous_chunks->set_is_free(true);
  2181 #endif
  2182     if (TraceMetadataChunkAllocation && Verbose) {
  2183       gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ",
  2184                           humongous_chunks,
  2185                           humongous_chunks->word_size());
  2187     assert(humongous_chunks->word_size() == (size_t)
  2188            align_size_up(humongous_chunks->word_size(),
  2189                              HumongousChunkGranularity),
  2190            err_msg("Humongous chunk size is wrong: word size " SIZE_FORMAT
  2191                    " granularity %d",
  2192                    humongous_chunks->word_size(), HumongousChunkGranularity));
  2193     Metachunk* next_humongous_chunks = humongous_chunks->next();
  2194     humongous_chunks->container()->dec_container_count();
  2195     chunk_manager->humongous_dictionary()->return_chunk(humongous_chunks);
  2196     humongous_chunks = next_humongous_chunks;
  2198   if (TraceMetadataChunkAllocation && Verbose) {
  2199     gclog_or_tty->print_cr("");
  2200     gclog_or_tty->print_cr("updated dictionary count %d %s",
  2201                      chunk_manager->humongous_dictionary()->total_count(),
  2202                      chunk_size_name(HumongousIndex));
  2204   chunk_manager->slow_locked_verify();
  2207 const char* SpaceManager::chunk_size_name(ChunkIndex index) const {
  2208   switch (index) {
  2209     case SpecializedIndex:
  2210       return "Specialized";
  2211     case SmallIndex:
  2212       return "Small";
  2213     case MediumIndex:
  2214       return "Medium";
  2215     case HumongousIndex:
  2216       return "Humongous";
  2217     default:
  2218       return NULL;
  2222 ChunkIndex ChunkManager::list_index(size_t size) {
  2223   switch (size) {
  2224     case SpecializedChunk:
  2225       assert(SpecializedChunk == ClassSpecializedChunk,
  2226              "Need branch for ClassSpecializedChunk");
  2227       return SpecializedIndex;
  2228     case SmallChunk:
  2229     case ClassSmallChunk:
  2230       return SmallIndex;
  2231     case MediumChunk:
  2232     case ClassMediumChunk:
  2233       return MediumIndex;
  2234     default:
  2235       assert(size > MediumChunk || size > ClassMediumChunk,
  2236              "Not a humongous chunk");
  2237       return HumongousIndex;
  2241 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
  2242   assert_lock_strong(_lock);
  2243   size_t min_size = TreeChunk<Metablock, FreeList>::min_size();
  2244   assert(word_size >= min_size,
  2245     err_msg("Should not deallocate dark matter " SIZE_FORMAT, word_size));
  2246   block_freelists()->return_block(p, word_size);
  2249 // Adds a chunk to the list of chunks in use.
  2250 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
  2252   assert(new_chunk != NULL, "Should not be NULL");
  2253   assert(new_chunk->next() == NULL, "Should not be on a list");
  2255   new_chunk->reset_empty();
  2257   // Find the correct list and and set the current
  2258   // chunk for that list.
  2259   ChunkIndex index = ChunkManager::list_index(new_chunk->word_size());
  2261   if (index != HumongousIndex) {
  2262     set_current_chunk(new_chunk);
  2263     new_chunk->set_next(chunks_in_use(index));
  2264     set_chunks_in_use(index, new_chunk);
  2265   } else {
  2266     // For null class loader data and DumpSharedSpaces, the first chunk isn't
  2267     // small, so small will be null.  Link this first chunk as the current
  2268     // chunk.
  2269     if (make_current) {
  2270       // Set as the current chunk but otherwise treat as a humongous chunk.
  2271       set_current_chunk(new_chunk);
  2273     // Link at head.  The _current_chunk only points to a humongous chunk for
  2274     // the null class loader metaspace (class and data virtual space managers)
  2275     // any humongous chunks so will not point to the tail
  2276     // of the humongous chunks list.
  2277     new_chunk->set_next(chunks_in_use(HumongousIndex));
  2278     set_chunks_in_use(HumongousIndex, new_chunk);
  2280     assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
  2283   // Add to the running sum of capacity
  2284   inc_size_metrics(new_chunk->word_size());
  2286   assert(new_chunk->is_empty(), "Not ready for reuse");
  2287   if (TraceMetadataChunkAllocation && Verbose) {
  2288     gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
  2289                         sum_count_in_chunks_in_use());
  2290     new_chunk->print_on(gclog_or_tty);
  2291     if (vs_list() != NULL) {
  2292       vs_list()->chunk_manager()->locked_print_free_chunks(tty);
  2297 Metachunk* SpaceManager::get_new_chunk(size_t word_size,
  2298                                        size_t grow_chunks_by_words) {
  2300   Metachunk* next = vs_list()->get_new_chunk(word_size,
  2301                                              grow_chunks_by_words,
  2302                                              medium_chunk_bunch());
  2304   if (TraceMetadataHumongousAllocation &&
  2305       SpaceManager::is_humongous(next->word_size())) {
  2306     gclog_or_tty->print_cr("  new humongous chunk word size " PTR_FORMAT,
  2307                            next->word_size());
  2310   return next;
  2313 MetaWord* SpaceManager::allocate(size_t word_size) {
  2314   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
  2316   // If only the dictionary is going to be used (i.e., no
  2317   // indexed free list), then there is a minimum size requirement.
  2318   // MinChunkSize is a placeholder for the real minimum size JJJ
  2319   size_t byte_size = word_size * BytesPerWord;
  2321   size_t byte_size_with_overhead = byte_size + Metablock::overhead();
  2323   size_t raw_bytes_size = MAX2(byte_size_with_overhead,
  2324                                Metablock::min_block_byte_size());
  2325   raw_bytes_size = ARENA_ALIGN(raw_bytes_size);
  2326   size_t raw_word_size = raw_bytes_size / BytesPerWord;
  2327   assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
  2329   BlockFreelist* fl =  block_freelists();
  2330   MetaWord* p = NULL;
  2331   // Allocation from the dictionary is expensive in the sense that
  2332   // the dictionary has to be searched for a size.  Don't allocate
  2333   // from the dictionary until it starts to get fat.  Is this
  2334   // a reasonable policy?  Maybe an skinny dictionary is fast enough
  2335   // for allocations.  Do some profiling.  JJJ
  2336   if (fl->total_size() > allocation_from_dictionary_limit) {
  2337     p = fl->get_block(raw_word_size);
  2339   if (p == NULL) {
  2340     p = allocate_work(raw_word_size);
  2342   Metadebug::deallocate_block_a_lot(this, raw_word_size);
  2344   return p;
  2347 // Returns the address of spaced allocated for "word_size".
  2348 // This methods does not know about blocks (Metablocks)
  2349 MetaWord* SpaceManager::allocate_work(size_t word_size) {
  2350   assert_lock_strong(_lock);
  2351 #ifdef ASSERT
  2352   if (Metadebug::test_metadata_failure()) {
  2353     return NULL;
  2355 #endif
  2356   // Is there space in the current chunk?
  2357   MetaWord* result = NULL;
  2359   // For DumpSharedSpaces, only allocate out of the current chunk which is
  2360   // never null because we gave it the size we wanted.   Caller reports out
  2361   // of memory if this returns null.
  2362   if (DumpSharedSpaces) {
  2363     assert(current_chunk() != NULL, "should never happen");
  2364     inc_used_metrics(word_size);
  2365     return current_chunk()->allocate(word_size); // caller handles null result
  2367   if (current_chunk() != NULL) {
  2368     result = current_chunk()->allocate(word_size);
  2371   if (result == NULL) {
  2372     result = grow_and_allocate(word_size);
  2374   if (result > 0) {
  2375     inc_used_metrics(word_size);
  2376     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
  2377            "Head of the list is being allocated");
  2380   return result;
  2383 void SpaceManager::verify() {
  2384   // If there are blocks in the dictionary, then
  2385   // verfication of chunks does not work since
  2386   // being in the dictionary alters a chunk.
  2387   if (block_freelists()->total_size() == 0) {
  2388     for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
  2389       Metachunk* curr = chunks_in_use(i);
  2390       while (curr != NULL) {
  2391         curr->verify();
  2392         verify_chunk_size(curr);
  2393         curr = curr->next();
  2399 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
  2400   assert(is_humongous(chunk->word_size()) ||
  2401          chunk->word_size() == medium_chunk_size() ||
  2402          chunk->word_size() == small_chunk_size() ||
  2403          chunk->word_size() == specialized_chunk_size(),
  2404          "Chunk size is wrong");
  2405   return;
  2408 #ifdef ASSERT
  2409 void SpaceManager::verify_allocated_blocks_words() {
  2410   // Verification is only guaranteed at a safepoint.
  2411   assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(),
  2412     "Verification can fail if the applications is running");
  2413   assert(allocated_blocks_words() == sum_used_in_chunks_in_use(),
  2414     err_msg("allocation total is not consistent " SIZE_FORMAT
  2415             " vs " SIZE_FORMAT,
  2416             allocated_blocks_words(), sum_used_in_chunks_in_use()));
  2419 #endif
  2421 void SpaceManager::dump(outputStream* const out) const {
  2422   size_t curr_total = 0;
  2423   size_t waste = 0;
  2424   uint i = 0;
  2425   size_t used = 0;
  2426   size_t capacity = 0;
  2428   // Add up statistics for all chunks in this SpaceManager.
  2429   for (ChunkIndex index = ZeroIndex;
  2430        index < NumberOfInUseLists;
  2431        index = next_chunk_index(index)) {
  2432     for (Metachunk* curr = chunks_in_use(index);
  2433          curr != NULL;
  2434          curr = curr->next()) {
  2435       out->print("%d) ", i++);
  2436       curr->print_on(out);
  2437       if (TraceMetadataChunkAllocation && Verbose) {
  2438         block_freelists()->print_on(out);
  2440       curr_total += curr->word_size();
  2441       used += curr->used_word_size();
  2442       capacity += curr->capacity_word_size();
  2443       waste += curr->free_word_size() + curr->overhead();;
  2447   size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size();
  2448   // Free space isn't wasted.
  2449   waste -= free;
  2451   out->print_cr("total of all chunks "  SIZE_FORMAT " used " SIZE_FORMAT
  2452                 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
  2453                 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
  2456 #ifndef PRODUCT
  2457 void SpaceManager::mangle_freed_chunks() {
  2458   for (ChunkIndex index = ZeroIndex;
  2459        index < NumberOfInUseLists;
  2460        index = next_chunk_index(index)) {
  2461     for (Metachunk* curr = chunks_in_use(index);
  2462          curr != NULL;
  2463          curr = curr->next()) {
  2464       curr->mangle();
  2468 #endif // PRODUCT
  2470 // MetaspaceAux
  2473 size_t MetaspaceAux::_allocated_capacity_words = 0;
  2474 size_t MetaspaceAux::_allocated_used_words = 0;
  2476 size_t MetaspaceAux::free_bytes() {
  2477   size_t result = 0;
  2478   if (Metaspace::class_space_list() != NULL) {
  2479     result = result + Metaspace::class_space_list()->free_bytes();
  2481   if (Metaspace::space_list() != NULL) {
  2482     result = result + Metaspace::space_list()->free_bytes();
  2484   return result;
  2487 void MetaspaceAux::dec_capacity(size_t words) {
  2488   assert_lock_strong(SpaceManager::expand_lock());
  2489   assert(words <= _allocated_capacity_words,
  2490     err_msg("About to decrement below 0: words " SIZE_FORMAT
  2491             " is greater than _allocated_capacity_words " SIZE_FORMAT,
  2492             words, _allocated_capacity_words));
  2493   _allocated_capacity_words = _allocated_capacity_words - words;
  2496 void MetaspaceAux::inc_capacity(size_t words) {
  2497   assert_lock_strong(SpaceManager::expand_lock());
  2498   // Needs to be atomic
  2499   _allocated_capacity_words = _allocated_capacity_words + words;
  2502 void MetaspaceAux::dec_used(size_t words) {
  2503   assert(words <= _allocated_used_words,
  2504     err_msg("About to decrement below 0: words " SIZE_FORMAT
  2505             " is greater than _allocated_used_words " SIZE_FORMAT,
  2506             words, _allocated_used_words));
  2507   // For CMS deallocation of the Metaspaces occurs during the
  2508   // sweep which is a concurrent phase.  Protection by the expand_lock()
  2509   // is not enough since allocation is on a per Metaspace basis
  2510   // and protected by the Metaspace lock.
  2511   jlong minus_words = (jlong) - (jlong) words;
  2512   Atomic::add_ptr(minus_words, &_allocated_used_words);
  2515 void MetaspaceAux::inc_used(size_t words) {
  2516   // _allocated_used_words tracks allocations for
  2517   // each piece of metadata.  Those allocations are
  2518   // generally done concurrently by different application
  2519   // threads so must be done atomically.
  2520   Atomic::add_ptr(words, &_allocated_used_words);
  2523 size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) {
  2524   size_t used = 0;
  2525   ClassLoaderDataGraphMetaspaceIterator iter;
  2526   while (iter.repeat()) {
  2527     Metaspace* msp = iter.get_next();
  2528     // Sum allocated_blocks_words for each metaspace
  2529     if (msp != NULL) {
  2530       used += msp->used_words_slow(mdtype);
  2533   return used * BytesPerWord;
  2536 size_t MetaspaceAux::free_in_bytes(Metaspace::MetadataType mdtype) {
  2537   size_t free = 0;
  2538   ClassLoaderDataGraphMetaspaceIterator iter;
  2539   while (iter.repeat()) {
  2540     Metaspace* msp = iter.get_next();
  2541     if (msp != NULL) {
  2542       free += msp->free_words(mdtype);
  2545   return free * BytesPerWord;
  2548 size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) {
  2549   // Don't count the space in the freelists.  That space will be
  2550   // added to the capacity calculation as needed.
  2551   size_t capacity = 0;
  2552   ClassLoaderDataGraphMetaspaceIterator iter;
  2553   while (iter.repeat()) {
  2554     Metaspace* msp = iter.get_next();
  2555     if (msp != NULL) {
  2556       capacity += msp->capacity_words_slow(mdtype);
  2559   return capacity * BytesPerWord;
  2562 size_t MetaspaceAux::reserved_in_bytes(Metaspace::MetadataType mdtype) {
  2563   size_t reserved = (mdtype == Metaspace::ClassType) ?
  2564                        Metaspace::class_space_list()->virtual_space_total() :
  2565                        Metaspace::space_list()->virtual_space_total();
  2566   return reserved * BytesPerWord;
  2569 size_t MetaspaceAux::min_chunk_size() { return Metaspace::first_chunk_word_size(); }
  2571 size_t MetaspaceAux::free_chunks_total(Metaspace::MetadataType mdtype) {
  2572   ChunkManager* chunk = (mdtype == Metaspace::ClassType) ?
  2573                             Metaspace::class_space_list()->chunk_manager() :
  2574                             Metaspace::space_list()->chunk_manager();
  2575   chunk->slow_verify();
  2576   return chunk->free_chunks_total();
  2579 size_t MetaspaceAux::free_chunks_total_in_bytes(Metaspace::MetadataType mdtype) {
  2580   return free_chunks_total(mdtype) * BytesPerWord;
  2583 size_t MetaspaceAux::free_chunks_total() {
  2584   return free_chunks_total(Metaspace::ClassType) +
  2585          free_chunks_total(Metaspace::NonClassType);
  2588 size_t MetaspaceAux::free_chunks_total_in_bytes() {
  2589   return free_chunks_total() * BytesPerWord;
  2592 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
  2593   gclog_or_tty->print(", [Metaspace:");
  2594   if (PrintGCDetails && Verbose) {
  2595     gclog_or_tty->print(" "  SIZE_FORMAT
  2596                         "->" SIZE_FORMAT
  2597                         "("  SIZE_FORMAT ")",
  2598                         prev_metadata_used,
  2599                         allocated_capacity_bytes(),
  2600                         reserved_in_bytes());
  2601   } else {
  2602     gclog_or_tty->print(" "  SIZE_FORMAT "K"
  2603                         "->" SIZE_FORMAT "K"
  2604                         "("  SIZE_FORMAT "K)",
  2605                         prev_metadata_used / K,
  2606                         allocated_capacity_bytes() / K,
  2607                         reserved_in_bytes()/ K);
  2610   gclog_or_tty->print("]");
  2613 // This is printed when PrintGCDetails
  2614 void MetaspaceAux::print_on(outputStream* out) {
  2615   Metaspace::MetadataType ct = Metaspace::ClassType;
  2616   Metaspace::MetadataType nct = Metaspace::NonClassType;
  2618   out->print_cr(" Metaspace total "
  2619                 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
  2620                 " reserved " SIZE_FORMAT "K",
  2621                 allocated_capacity_bytes()/K, allocated_used_bytes()/K, reserved_in_bytes()/K);
  2622 #if 0
  2623 // The calls to capacity_bytes_slow() and used_bytes_slow() cause
  2624 // lock ordering assertion failures with some collectors.  Do
  2625 // not include this code until the lock ordering is fixed.
  2626   if (PrintGCDetails && Verbose) {
  2627     out->print_cr("  data space     "
  2628                   SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
  2629                   " reserved " SIZE_FORMAT "K",
  2630                   capacity_bytes_slow(nct)/K, used_bytes_slow(nct)/K, reserved_in_bytes(nct)/K);
  2631     out->print_cr("  class space    "
  2632                   SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
  2633                   " reserved " SIZE_FORMAT "K",
  2634                   capacity_bytes_slow(ct)/K, used_bytes_slow(ct)/K, reserved_in_bytes(ct)/K);
  2636 #endif
  2639 // Print information for class space and data space separately.
  2640 // This is almost the same as above.
  2641 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
  2642   size_t free_chunks_capacity_bytes = free_chunks_total_in_bytes(mdtype);
  2643   size_t capacity_bytes = capacity_bytes_slow(mdtype);
  2644   size_t used_bytes = used_bytes_slow(mdtype);
  2645   size_t free_bytes = free_in_bytes(mdtype);
  2646   size_t used_and_free = used_bytes + free_bytes +
  2647                            free_chunks_capacity_bytes;
  2648   out->print_cr("  Chunk accounting: used in chunks " SIZE_FORMAT
  2649              "K + unused in chunks " SIZE_FORMAT "K  + "
  2650              " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
  2651              "K  capacity in allocated chunks " SIZE_FORMAT "K",
  2652              used_bytes / K,
  2653              free_bytes / K,
  2654              free_chunks_capacity_bytes / K,
  2655              used_and_free / K,
  2656              capacity_bytes / K);
  2657   // Accounting can only be correct if we got the values during a safepoint
  2658   assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong");
  2661 // Print total fragmentation for class and data metaspaces separately
  2662 void MetaspaceAux::print_waste(outputStream* out) {
  2664   size_t specialized_waste = 0, small_waste = 0, medium_waste = 0, large_waste = 0;
  2665   size_t specialized_count = 0, small_count = 0, medium_count = 0, large_count = 0;
  2666   size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0, cls_large_waste = 0;
  2667   size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_large_count = 0;
  2669   ClassLoaderDataGraphMetaspaceIterator iter;
  2670   while (iter.repeat()) {
  2671     Metaspace* msp = iter.get_next();
  2672     if (msp != NULL) {
  2673       specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
  2674       specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
  2675       small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
  2676       small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
  2677       medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
  2678       medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
  2679       large_waste += msp->vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
  2680       large_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
  2682       cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
  2683       cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
  2684       cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
  2685       cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
  2686       cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
  2687       cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
  2688       cls_large_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
  2689       cls_large_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
  2692   out->print_cr("Total fragmentation waste (words) doesn't count free space");
  2693   out->print_cr("  data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
  2694                         SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
  2695                         SIZE_FORMAT " medium(s) " SIZE_FORMAT,
  2696              specialized_count, specialized_waste, small_count,
  2697              small_waste, medium_count, medium_waste);
  2698   out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
  2699                            SIZE_FORMAT " small(s) " SIZE_FORMAT,
  2700              cls_specialized_count, cls_specialized_waste,
  2701              cls_small_count, cls_small_waste);
  2704 // Dump global metaspace things from the end of ClassLoaderDataGraph
  2705 void MetaspaceAux::dump(outputStream* out) {
  2706   out->print_cr("All Metaspace:");
  2707   out->print("data space: "); print_on(out, Metaspace::NonClassType);
  2708   out->print("class space: "); print_on(out, Metaspace::ClassType);
  2709   print_waste(out);
  2712 void MetaspaceAux::verify_free_chunks() {
  2713   Metaspace::space_list()->chunk_manager()->verify();
  2714   Metaspace::class_space_list()->chunk_manager()->verify();
  2717 void MetaspaceAux::verify_capacity() {
  2718 #ifdef ASSERT
  2719   size_t running_sum_capacity_bytes = allocated_capacity_bytes();
  2720   // For purposes of the running sum of used, verify against capacity
  2721   size_t capacity_in_use_bytes = capacity_bytes_slow();
  2722   assert(running_sum_capacity_bytes == capacity_in_use_bytes,
  2723     err_msg("allocated_capacity_words() * BytesPerWord " SIZE_FORMAT
  2724             " capacity_bytes_slow()" SIZE_FORMAT,
  2725             running_sum_capacity_bytes, capacity_in_use_bytes));
  2726 #endif
  2729 void MetaspaceAux::verify_used() {
  2730 #ifdef ASSERT
  2731   size_t running_sum_used_bytes = allocated_used_bytes();
  2732   // For purposes of the running sum of used, verify against capacity
  2733   size_t used_in_use_bytes = used_bytes_slow();
  2734   assert(allocated_used_bytes() == used_in_use_bytes,
  2735     err_msg("allocated_used_bytes() " SIZE_FORMAT
  2736             " used_bytes_slow()()" SIZE_FORMAT,
  2737             allocated_used_bytes(), used_in_use_bytes));
  2738 #endif
  2741 void MetaspaceAux::verify_metrics() {
  2742   verify_capacity();
  2743   verify_used();
  2747 // Metaspace methods
  2749 size_t Metaspace::_first_chunk_word_size = 0;
  2750 size_t Metaspace::_first_class_chunk_word_size = 0;
  2752 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
  2753   initialize(lock, type);
  2756 Metaspace::~Metaspace() {
  2757   delete _vsm;
  2758   delete _class_vsm;
  2761 VirtualSpaceList* Metaspace::_space_list = NULL;
  2762 VirtualSpaceList* Metaspace::_class_space_list = NULL;
  2764 #define VIRTUALSPACEMULTIPLIER 2
  2766 void Metaspace::global_initialize() {
  2767   // Initialize the alignment for shared spaces.
  2768   int max_alignment = os::vm_page_size();
  2769   MetaspaceShared::set_max_alignment(max_alignment);
  2771   if (DumpSharedSpaces) {
  2772     SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
  2773     SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
  2774     SharedMiscDataSize  = align_size_up(SharedMiscDataSize, max_alignment);
  2775     SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize, max_alignment);
  2777     // Initialize with the sum of the shared space sizes.  The read-only
  2778     // and read write metaspace chunks will be allocated out of this and the
  2779     // remainder is the misc code and data chunks.
  2780     size_t total = align_size_up(SharedReadOnlySize + SharedReadWriteSize +
  2781                                  SharedMiscDataSize + SharedMiscCodeSize,
  2782                                  os::vm_allocation_granularity());
  2783     size_t word_size = total/wordSize;
  2784     _space_list = new VirtualSpaceList(word_size);
  2785   } else {
  2786     // If using shared space, open the file that contains the shared space
  2787     // and map in the memory before initializing the rest of metaspace (so
  2788     // the addresses don't conflict)
  2789     if (UseSharedSpaces) {
  2790       FileMapInfo* mapinfo = new FileMapInfo();
  2791       memset(mapinfo, 0, sizeof(FileMapInfo));
  2793       // Open the shared archive file, read and validate the header. If
  2794       // initialization fails, shared spaces [UseSharedSpaces] are
  2795       // disabled and the file is closed.
  2796       // Map in spaces now also
  2797       if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
  2798         FileMapInfo::set_current_info(mapinfo);
  2799       } else {
  2800         assert(!mapinfo->is_open() && !UseSharedSpaces,
  2801                "archive file not closed or shared spaces not disabled.");
  2805     // Initialize these before initializing the VirtualSpaceList
  2806     _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
  2807     _first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
  2808     // Make the first class chunk bigger than a medium chunk so it's not put
  2809     // on the medium chunk list.   The next chunk will be small and progress
  2810     // from there.  This size calculated by -version.
  2811     _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
  2812                                        (ClassMetaspaceSize/BytesPerWord)*2);
  2813     _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
  2814     // Arbitrarily set the initial virtual space to a multiple
  2815     // of the boot class loader size.
  2816     size_t word_size = VIRTUALSPACEMULTIPLIER * first_chunk_word_size();
  2817     // Initialize the list of virtual spaces.
  2818     _space_list = new VirtualSpaceList(word_size);
  2822 // For UseCompressedKlassPointers the class space is reserved as a piece of the
  2823 // Java heap because the compression algorithm is the same for each.  The
  2824 // argument passed in is at the top of the compressed space
  2825 void Metaspace::initialize_class_space(ReservedSpace rs) {
  2826   // The reserved space size may be bigger because of alignment, esp with UseLargePages
  2827   assert(rs.size() >= ClassMetaspaceSize,
  2828          err_msg(SIZE_FORMAT " != " UINTX_FORMAT, rs.size(), ClassMetaspaceSize));
  2829   _class_space_list = new VirtualSpaceList(rs);
  2832 void Metaspace::initialize(Mutex* lock,
  2833                            MetaspaceType type) {
  2835   assert(space_list() != NULL,
  2836     "Metadata VirtualSpaceList has not been initialized");
  2838   _vsm = new SpaceManager(lock, space_list());
  2839   if (_vsm == NULL) {
  2840     return;
  2842   size_t word_size;
  2843   size_t class_word_size;
  2844   vsm()->get_initial_chunk_sizes(type,
  2845                                  &word_size,
  2846                                  &class_word_size);
  2848   assert(class_space_list() != NULL,
  2849     "Class VirtualSpaceList has not been initialized");
  2851   // Allocate SpaceManager for classes.
  2852   _class_vsm = new SpaceManager(lock, class_space_list());
  2853   if (_class_vsm == NULL) {
  2854     return;
  2857   MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
  2859   // Allocate chunk for metadata objects
  2860   Metachunk* new_chunk =
  2861      space_list()->get_initialization_chunk(word_size,
  2862                                             vsm()->medium_chunk_bunch());
  2863   assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
  2864   if (new_chunk != NULL) {
  2865     // Add to this manager's list of chunks in use and current_chunk().
  2866     vsm()->add_chunk(new_chunk, true);
  2869   // Allocate chunk for class metadata objects
  2870   Metachunk* class_chunk =
  2871      class_space_list()->get_initialization_chunk(class_word_size,
  2872                                                   class_vsm()->medium_chunk_bunch());
  2873   if (class_chunk != NULL) {
  2874     class_vsm()->add_chunk(class_chunk, true);
  2878 size_t Metaspace::align_word_size_up(size_t word_size) {
  2879   size_t byte_size = word_size * wordSize;
  2880   return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
  2883 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
  2884   // DumpSharedSpaces doesn't use class metadata area (yet)
  2885   if (mdtype == ClassType && !DumpSharedSpaces) {
  2886     return  class_vsm()->allocate(word_size);
  2887   } else {
  2888     return  vsm()->allocate(word_size);
  2892 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
  2893   MetaWord* result;
  2894   MetaspaceGC::set_expand_after_GC(true);
  2895   size_t before_inc = MetaspaceGC::capacity_until_GC();
  2896   size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size) * BytesPerWord;
  2897   MetaspaceGC::inc_capacity_until_GC(delta_bytes);
  2898   if (PrintGCDetails && Verbose) {
  2899     gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
  2900       " to " SIZE_FORMAT, before_inc, MetaspaceGC::capacity_until_GC());
  2903   result = allocate(word_size, mdtype);
  2905   return result;
  2908 // Space allocated in the Metaspace.  This may
  2909 // be across several metadata virtual spaces.
  2910 char* Metaspace::bottom() const {
  2911   assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
  2912   return (char*)vsm()->current_chunk()->bottom();
  2915 size_t Metaspace::used_words_slow(MetadataType mdtype) const {
  2916   // return vsm()->allocated_used_words();
  2917   return mdtype == ClassType ? class_vsm()->sum_used_in_chunks_in_use() :
  2918                                vsm()->sum_used_in_chunks_in_use();  // includes overhead!
  2921 size_t Metaspace::free_words(MetadataType mdtype) const {
  2922   return mdtype == ClassType ? class_vsm()->sum_free_in_chunks_in_use() :
  2923                                vsm()->sum_free_in_chunks_in_use();
  2926 // Space capacity in the Metaspace.  It includes
  2927 // space in the list of chunks from which allocations
  2928 // have been made. Don't include space in the global freelist and
  2929 // in the space available in the dictionary which
  2930 // is already counted in some chunk.
  2931 size_t Metaspace::capacity_words_slow(MetadataType mdtype) const {
  2932   return mdtype == ClassType ? class_vsm()->sum_capacity_in_chunks_in_use() :
  2933                                vsm()->sum_capacity_in_chunks_in_use();
  2936 size_t Metaspace::used_bytes_slow(MetadataType mdtype) const {
  2937   return used_words_slow(mdtype) * BytesPerWord;
  2940 size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const {
  2941   return capacity_words_slow(mdtype) * BytesPerWord;
  2944 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
  2945   if (SafepointSynchronize::is_at_safepoint()) {
  2946     assert(Thread::current()->is_VM_thread(), "should be the VM thread");
  2947     // Don't take Heap_lock
  2948     MutexLocker ml(vsm()->lock());
  2949     if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
  2950       // Dark matter.  Too small for dictionary.
  2951 #ifdef ASSERT
  2952       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
  2953 #endif
  2954       return;
  2956     if (is_class) {
  2957        class_vsm()->deallocate(ptr, word_size);
  2958     } else {
  2959       vsm()->deallocate(ptr, word_size);
  2961   } else {
  2962     MutexLocker ml(vsm()->lock());
  2964     if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
  2965       // Dark matter.  Too small for dictionary.
  2966 #ifdef ASSERT
  2967       Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
  2968 #endif
  2969       return;
  2971     if (is_class) {
  2972       class_vsm()->deallocate(ptr, word_size);
  2973     } else {
  2974       vsm()->deallocate(ptr, word_size);
  2979 Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
  2980                               bool read_only, MetadataType mdtype, TRAPS) {
  2981   if (HAS_PENDING_EXCEPTION) {
  2982     assert(false, "Should not allocate with exception pending");
  2983     return NULL;  // caller does a CHECK_NULL too
  2986   // SSS: Should we align the allocations and make sure the sizes are aligned.
  2987   MetaWord* result = NULL;
  2989   assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
  2990         "ClassLoaderData::the_null_class_loader_data() should have been used.");
  2991   // Allocate in metaspaces without taking out a lock, because it deadlocks
  2992   // with the SymbolTable_lock.  Dumping is single threaded for now.  We'll have
  2993   // to revisit this for application class data sharing.
  2994   if (DumpSharedSpaces) {
  2995     if (read_only) {
  2996       result = loader_data->ro_metaspace()->allocate(word_size, NonClassType);
  2997     } else {
  2998       result = loader_data->rw_metaspace()->allocate(word_size, NonClassType);
  3000     if (result == NULL) {
  3001       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
  3003     return Metablock::initialize(result, word_size);
  3006   result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
  3008   if (result == NULL) {
  3009     // Try to clean out some memory and retry.
  3010     result =
  3011       Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
  3012         loader_data, word_size, mdtype);
  3014     // If result is still null, we are out of memory.
  3015     if (result == NULL) {
  3016       if (Verbose && TraceMetadataChunkAllocation) {
  3017         gclog_or_tty->print_cr("Metaspace allocation failed for size "
  3018           SIZE_FORMAT, word_size);
  3019         if (loader_data->metaspace_or_null() != NULL) loader_data->metaspace_or_null()->dump(gclog_or_tty);
  3020         MetaspaceAux::dump(gclog_or_tty);
  3022       // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
  3023       report_java_out_of_memory("Metadata space");
  3025       if (JvmtiExport::should_post_resource_exhausted()) {
  3026         JvmtiExport::post_resource_exhausted(
  3027             JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
  3028             "Metadata space");
  3030       THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
  3033   return Metablock::initialize(result, word_size);
  3036 void Metaspace::purge() {
  3037   MutexLockerEx cl(SpaceManager::expand_lock(),
  3038                    Mutex::_no_safepoint_check_flag);
  3039   space_list()->purge();
  3040   class_space_list()->purge();
  3043 void Metaspace::print_on(outputStream* out) const {
  3044   // Print both class virtual space counts and metaspace.
  3045   if (Verbose) {
  3046       vsm()->print_on(out);
  3047       class_vsm()->print_on(out);
  3051 bool Metaspace::contains(const void * ptr) {
  3052   if (MetaspaceShared::is_in_shared_space(ptr)) {
  3053     return true;
  3055   // This is checked while unlocked.  As long as the virtualspaces are added
  3056   // at the end, the pointer will be in one of them.  The virtual spaces
  3057   // aren't deleted presently.  When they are, some sort of locking might
  3058   // be needed.  Note, locking this can cause inversion problems with the
  3059   // caller in MetaspaceObj::is_metadata() function.
  3060   return space_list()->contains(ptr) ||
  3061          class_space_list()->contains(ptr);
  3064 void Metaspace::verify() {
  3065   vsm()->verify();
  3066   class_vsm()->verify();
  3069 void Metaspace::dump(outputStream* const out) const {
  3070   out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
  3071   vsm()->dump(out);
  3072   out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
  3073   class_vsm()->dump(out);

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