changeset 50193:49c3e91c424f

8176808: Split up metaspace.cpp Reviewed-by: asiebenborn, coleenp
author stuefe
date Mon, 21 May 2018 11:33:59 +0200
parents 8bc79d2d1568
children 2ae4cd9d809d
files src/hotspot/share/gc/cms/vmStructs_cms.hpp src/hotspot/share/memory/binaryTreeDictionary.hpp src/hotspot/share/memory/binaryTreeDictionary.inline.hpp src/hotspot/share/memory/freeList.inline.hpp src/hotspot/share/memory/metachunk.cpp src/hotspot/share/memory/metachunk.hpp src/hotspot/share/memory/metaspace.cpp src/hotspot/share/memory/metaspace.hpp src/hotspot/share/memory/metaspace/blockFreelist.cpp src/hotspot/share/memory/metaspace/blockFreelist.hpp src/hotspot/share/memory/metaspace/chunkManager.cpp src/hotspot/share/memory/metaspace/chunkManager.hpp src/hotspot/share/memory/metaspace/metaDebug.cpp src/hotspot/share/memory/metaspace/metaDebug.hpp src/hotspot/share/memory/metaspace/metabase.hpp src/hotspot/share/memory/metaspace/metablock.hpp src/hotspot/share/memory/metaspace/metachunk.cpp src/hotspot/share/memory/metaspace/metachunk.hpp src/hotspot/share/memory/metaspace/metaspaceCommon.cpp src/hotspot/share/memory/metaspace/metaspaceCommon.hpp src/hotspot/share/memory/metaspace/metaspaceDCmd.hpp src/hotspot/share/memory/metaspace/metaspaceStatistics.cpp src/hotspot/share/memory/metaspace/metaspaceStatistics.hpp src/hotspot/share/memory/metaspace/occupancyMap.cpp src/hotspot/share/memory/metaspace/occupancyMap.hpp src/hotspot/share/memory/metaspace/printCLDMetaspaceInfoClosure.cpp src/hotspot/share/memory/metaspace/printCLDMetaspaceInfoClosure.hpp src/hotspot/share/memory/metaspace/smallBlocks.cpp src/hotspot/share/memory/metaspace/smallBlocks.hpp src/hotspot/share/memory/metaspace/spaceManager.cpp src/hotspot/share/memory/metaspace/spaceManager.hpp src/hotspot/share/memory/metaspace/virtualSpaceList.cpp src/hotspot/share/memory/metaspace/virtualSpaceList.hpp src/hotspot/share/memory/metaspace/virtualSpaceNode.cpp src/hotspot/share/memory/metaspace/virtualSpaceNode.hpp src/hotspot/share/runtime/vmStructs.cpp test/hotspot/gtest/memory/test_chunkManager.cpp test/hotspot/gtest/memory/test_metachunk.cpp test/hotspot/gtest/memory/test_spaceManager.cpp
diffstat 39 files changed, 4698 insertions(+), 3911 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/cms/vmStructs_cms.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/gc/cms/vmStructs_cms.hpp	Mon May 21 11:33:59 2018 +0200
@@ -70,7 +70,7 @@
   declare_toplevel_type(CMSCollector)                                     \
   declare_toplevel_type(CMSBitMap)                                        \
   declare_toplevel_type(FreeChunk)                                        \
-  declare_toplevel_type(Metablock)                                        \
+  declare_toplevel_type(metaspace::Metablock)                             \
   declare_toplevel_type(ConcurrentMarkSweepThread*)                       \
   declare_toplevel_type(ConcurrentMarkSweepGeneration*)                   \
   declare_toplevel_type(CompactibleFreeListSpace*)                        \
--- a/src/hotspot/share/memory/binaryTreeDictionary.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/binaryTreeDictionary.hpp	Mon May 21 11:33:59 2018 +0200
@@ -26,6 +26,9 @@
 #define SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP
 
 #include "memory/freeList.hpp"
+#include "memory/memRegion.hpp"
+
+class Mutex;
 
 /*
  * A binary tree based search structure for free blocks.
@@ -276,15 +279,7 @@
   }
 
   size_t     max_chunk_size() const;
-  size_t     total_chunk_size(debug_only(const Mutex* lock)) const {
-    debug_only(
-      if (lock != NULL && lock->owned_by_self()) {
-        assert(total_size_in_tree(root()) == total_size(),
-               "_total_size inconsistency");
-      }
-    )
-    return total_size();
-  }
+  inline size_t total_chunk_size(debug_only(const Mutex* lock)) const;
 
   size_t     min_size() const {
     return TreeChunk<Chunk_t, FreeList_t>::min_size();
--- a/src/hotspot/share/memory/binaryTreeDictionary.inline.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/binaryTreeDictionary.inline.hpp	Mon May 21 11:33:59 2018 +0200
@@ -30,8 +30,8 @@
 #include "logging/logStream.hpp"
 #include "memory/binaryTreeDictionary.hpp"
 #include "memory/freeList.inline.hpp"
-#include "memory/metachunk.hpp"
 #include "memory/resourceArea.hpp"
+#include "runtime/mutex.hpp"
 #include "runtime/globals.hpp"
 #include "utilities/macros.hpp"
 #include "utilities/ostream.hpp"
@@ -1022,4 +1022,15 @@
   guarantee(total_size() == total_size_in_tree(root()), "Total Size inconsistency");
 }
 
+template <class Chunk_t, class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_chunk_size(debug_only(const Mutex* lock)) const {
+  debug_only(
+    if (lock != NULL && lock->owned_by_self()) {
+      assert(total_size_in_tree(root()) == total_size(),
+             "_total_size inconsistency");
+    }
+  )
+  return total_size();
+}
+
 #endif // SHARE_VM_MEMORY_BINARYTREEDICTIONARY_INLINE_HPP
--- a/src/hotspot/share/memory/freeList.inline.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/freeList.inline.hpp	Mon May 21 11:33:59 2018 +0200
@@ -27,7 +27,6 @@
 
 #include "gc/shared/collectedHeap.hpp"
 #include "memory/freeList.hpp"
-#include "memory/metachunk.hpp"
 #include "runtime/globals.hpp"
 #include "runtime/mutex.hpp"
 #include "runtime/vmThread.hpp"
--- a/src/hotspot/share/memory/metachunk.cpp	Sun May 20 22:10:45 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,149 +0,0 @@
-/*
- * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "precompiled.hpp"
-#include "memory/allocation.hpp"
-#include "memory/metachunk.hpp"
-#include "utilities/align.hpp"
-#include "utilities/copy.hpp"
-#include "utilities/debug.hpp"
-
-class VirtualSpaceNode;
-
-size_t Metachunk::object_alignment() {
-  // Must align pointers and sizes to 8,
-  // so that 64 bit types get correctly aligned.
-  const size_t alignment = 8;
-
-  // Make sure that the Klass alignment also agree.
-  STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes);
-
-  return alignment;
-}
-
-size_t Metachunk::overhead() {
-  return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord;
-}
-
-// Metachunk methods
-
-Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size,
-                     VirtualSpaceNode* container)
-    : Metabase<Metachunk>(word_size),
-    _chunk_type(chunktype),
-    _is_class(is_class),
-    _sentinel(CHUNK_SENTINEL),
-    _origin(origin_normal),
-    _use_count(0),
-    _top(NULL),
-    _container(container)
-{
-  _top = initial_top();
-  set_is_tagged_free(false);
-#ifdef ASSERT
-  mangle(uninitMetaWordVal);
-  verify();
-#endif
-}
-
-MetaWord* Metachunk::allocate(size_t word_size) {
-  MetaWord* result = NULL;
-  // If available, bump the pointer to allocate.
-  if (free_word_size() >= word_size) {
-    result = _top;
-    _top = _top + word_size;
-  }
-  return result;
-}
-
-// _bottom points to the start of the chunk including the overhead.
-size_t Metachunk::used_word_size() const {
-  return pointer_delta(_top, bottom(), sizeof(MetaWord));
-}
-
-size_t Metachunk::free_word_size() const {
-  return pointer_delta(end(), _top, sizeof(MetaWord));
-}
-
-void Metachunk::print_on(outputStream* st) const {
-  st->print_cr("Metachunk:"
-               " bottom " PTR_FORMAT " top " PTR_FORMAT
-               " end " PTR_FORMAT " size " SIZE_FORMAT " (%s)",
-               p2i(bottom()), p2i(_top), p2i(end()), word_size(),
-               chunk_size_name(get_chunk_type()));
-  if (Verbose) {
-    st->print_cr("    used " SIZE_FORMAT " free " SIZE_FORMAT,
-                 used_word_size(), free_word_size());
-  }
-}
-
-#ifdef ASSERT
-void Metachunk::mangle(juint word_value) {
-  // Overwrite the payload of the chunk and not the links that
-  // maintain list of chunks.
-  HeapWord* start = (HeapWord*)initial_top();
-  size_t size = word_size() - overhead();
-  Copy::fill_to_words(start, size, word_value);
-}
-
-void Metachunk::verify() const {
-  assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this));
-  const ChunkIndex chunk_type = get_chunk_type();
-  assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this));
-  if (chunk_type != HumongousIndex) {
-    assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()),
-           "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.",
-           p2i(this), word_size(), chunk_size_name(chunk_type));
-  }
-  assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this));
-  assert(bottom() <= _top && _top <= (MetaWord*)end(),
-         "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this));
-
-  // For non-humongous chunks, starting address shall be aligned
-  // to its chunk size. Humongous chunks start address is
-  // aligned to specialized chunk size.
-  const size_t required_alignment =
-    (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord);
-  assert(is_aligned((address)this, required_alignment),
-         "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".",
-         p2i(this), word_size() * sizeof(MetaWord), required_alignment);
-}
-
-#endif // ASSERT
-
-// Helper, returns a descriptive name for the given index.
-const char* chunk_size_name(ChunkIndex index) {
-  switch (index) {
-    case SpecializedIndex:
-      return "specialized";
-    case SmallIndex:
-      return "small";
-    case MediumIndex:
-      return "medium";
-    case HumongousIndex:
-      return "humongous";
-    default:
-      return "Invalid index";
-  }
-}
--- a/src/hotspot/share/memory/metachunk.hpp	Sun May 20 22:10:45 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,250 +0,0 @@
-/*
- * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-#ifndef SHARE_VM_MEMORY_METACHUNK_HPP
-#define SHARE_VM_MEMORY_METACHUNK_HPP
-
-#include "utilities/debug.hpp"
-#include "utilities/globalDefinitions.hpp"
-
-class VirtualSpaceNode;
-
-// Super class of Metablock and Metachunk to allow them to
-// be put on the FreeList and in the BinaryTreeDictionary.
-template <class T>
-class Metabase {
-  size_t _word_size;
-  T*     _next;
-  T*     _prev;
-
- protected:
-  Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {}
-
- public:
-  T* next() const         { return _next; }
-  T* prev() const         { return _prev; }
-  void set_next(T* v)     { _next = v; assert(v != this, "Boom");}
-  void set_prev(T* v)     { _prev = v; assert(v != this, "Boom");}
-  void clear_next()       { set_next(NULL); }
-  void clear_prev()       { set_prev(NULL); }
-
-  size_t size() const volatile { return _word_size; }
-  void set_size(size_t v) { _word_size = v; }
-
-  void link_next(T* ptr)  { set_next(ptr); }
-  void link_prev(T* ptr)  { set_prev(ptr); }
-  void link_after(T* ptr) {
-    link_next(ptr);
-    if (ptr != NULL) ptr->link_prev((T*)this);
-  }
-
-  uintptr_t* end() const        { return ((uintptr_t*) this) + size(); }
-
-  bool cantCoalesce() const     { return false; }
-
-  // Debug support
-#ifdef ASSERT
-  void* prev_addr() const { return (void*)&_prev; }
-  void* next_addr() const { return (void*)&_next; }
-  void* size_addr() const { return (void*)&_word_size; }
-#endif
-  bool verify_chunk_in_free_list(T* tc) const { return true; }
-  bool verify_par_locked() { return true; }
-
-  void assert_is_mangled() const {/* Don't check "\*/}
-
-  bool is_free()                 { return true; }
-};
-
-//  Metachunk - Quantum of allocation from a Virtualspace
-//    Metachunks are reused (when freed are put on a global freelist) and
-//    have no permanent association to a SpaceManager.
-
-//            +--------------+ <- end    --+       --+
-//            |              |             |         |
-//            |              |             | free    |
-//            |              |             |         |
-//            |              |             |         | size | capacity
-//            |              |             |         |
-//            |              | <- top   -- +         |
-//            |              |             |         |
-//            |              |             | used    |
-//            |              |             |         |
-//            |              |             |         |
-//            +--------------+ <- bottom --+       --+
-
-// ChunkIndex defines the type of chunk.
-// Chunk types differ by size: specialized < small < medium, chunks
-// larger than medium are humongous chunks of varying size.
-enum ChunkIndex {
-  ZeroIndex = 0,
-  SpecializedIndex = ZeroIndex,
-  SmallIndex = SpecializedIndex + 1,
-  MediumIndex = SmallIndex + 1,
-  HumongousIndex = MediumIndex + 1,
-  NumberOfFreeLists = 3,
-  NumberOfInUseLists = 4
-};
-
-// Utility functions.
-size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunk_type, bool is_class);
-ChunkIndex get_chunk_type_by_size(size_t size, bool is_class);
-
-ChunkIndex next_chunk_index(ChunkIndex i);
-ChunkIndex prev_chunk_index(ChunkIndex i);
-
-// Returns a descriptive name for a chunk type.
-const char* chunk_size_name(ChunkIndex index);
-
-// Verify chunk type.
-inline bool is_valid_chunktype(ChunkIndex index) {
-  return index == SpecializedIndex || index == SmallIndex ||
-         index == MediumIndex || index == HumongousIndex;
-}
-
-inline bool is_valid_nonhumongous_chunktype(ChunkIndex index) {
-  return is_valid_chunktype(index) && index != HumongousIndex;
-}
-
-enum ChunkOrigin {
-  // Chunk normally born (via take_from_committed)
-  origin_normal = 1,
-  // Chunk was born as padding chunk
-  origin_pad = 2,
-  // Chunk was born as leftover chunk in VirtualSpaceNode::retire
-  origin_leftover = 3,
-  // Chunk was born as result of a merge of smaller chunks
-  origin_merge = 4,
-  // Chunk was born as result of a split of a larger chunk
-  origin_split = 5,
-
-  origin_minimum = origin_normal,
-  origin_maximum = origin_split,
-  origins_count = origin_maximum + 1
-};
-
-inline bool is_valid_chunkorigin(ChunkOrigin origin) {
-  return origin == origin_normal ||
-    origin == origin_pad ||
-    origin == origin_leftover ||
-    origin == origin_merge ||
-    origin == origin_split;
-}
-
-class Metachunk : public Metabase<Metachunk> {
-  friend class MetachunkTest;
-  // The VirtualSpaceNode containing this chunk.
-  VirtualSpaceNode* const _container;
-
-  // Current allocation top.
-  MetaWord* _top;
-
-  // A 32bit sentinel for debugging purposes.
-  enum { CHUNK_SENTINEL = 0x4d4554EF,  // "MET"
-         CHUNK_SENTINEL_INVALID = 0xFEEEEEEF
-  };
-
-  uint32_t _sentinel;
-
-  const ChunkIndex _chunk_type;
-  const bool _is_class;
-  // Whether the chunk is free (in freelist) or in use by some class loader.
-  bool _is_tagged_free;
-
-  ChunkOrigin _origin;
-  int _use_count;
-
-  MetaWord* initial_top() const { return (MetaWord*)this + overhead(); }
-  MetaWord* top() const         { return _top; }
-
- public:
-  // Metachunks are allocated out of a MetadataVirtualSpace and
-  // and use some of its space to describe itself (plus alignment
-  // considerations).  Metadata is allocated in the rest of the chunk.
-  // This size is the overhead of maintaining the Metachunk within
-  // the space.
-
-  // Alignment of each allocation in the chunks.
-  static size_t object_alignment();
-
-  // Size of the Metachunk header, in words, including alignment.
-  static size_t overhead();
-
-  Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size, VirtualSpaceNode* container);
-
-  MetaWord* allocate(size_t word_size);
-
-  VirtualSpaceNode* container() const { return _container; }
-
-  MetaWord* bottom() const { return (MetaWord*) this; }
-
-  // Reset top to bottom so chunk can be reused.
-  void reset_empty() { _top = initial_top(); clear_next(); clear_prev(); }
-  bool is_empty() { return _top == initial_top(); }
-
-  // used (has been allocated)
-  // free (available for future allocations)
-  size_t word_size() const { return size(); }
-  size_t used_word_size() const;
-  size_t free_word_size() const;
-
-  bool is_tagged_free() { return _is_tagged_free; }
-  void set_is_tagged_free(bool v) { _is_tagged_free = v; }
-
-  bool contains(const void* ptr) { return bottom() <= ptr && ptr < _top; }
-
-  void print_on(outputStream* st) const;
-
-  bool is_valid_sentinel() const        { return _sentinel == CHUNK_SENTINEL; }
-  void remove_sentinel()                { _sentinel = CHUNK_SENTINEL_INVALID; }
-
-  int get_use_count() const             { return _use_count; }
-  void inc_use_count()                  { _use_count ++; }
-
-  ChunkOrigin get_origin() const        { return _origin; }
-  void set_origin(ChunkOrigin orig)     { _origin = orig; }
-
-  ChunkIndex get_chunk_type() const     { return _chunk_type; }
-  bool is_class() const                 { return _is_class; }
-
-  DEBUG_ONLY(void mangle(juint word_value);)
-  DEBUG_ONLY(void verify() const;)
-
-};
-
-// Metablock is the unit of allocation from a Chunk.
-//
-// A Metablock may be reused by its SpaceManager but are never moved between
-// SpaceManagers.  There is no explicit link to the Metachunk
-// from which it was allocated.  Metablock may be deallocated and
-// put on a freelist but the space is never freed, rather
-// the Metachunk it is a part of will be deallocated when it's
-// associated class loader is collected.
-
-class Metablock : public Metabase<Metablock> {
-  friend class VMStructs;
- public:
-  Metablock(size_t word_size) : Metabase<Metablock>(word_size) {}
-};
-
-#endif  // SHARE_VM_MEMORY_METACHUNK_HPP
--- a/src/hotspot/share/memory/metaspace.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace.cpp	Mon May 21 11:33:59 2018 +0200
@@ -21,53 +21,31 @@
  * questions.
  *
  */
+
 #include "precompiled.hpp"
+
 #include "aot/aotLoader.hpp"
-#include "gc/shared/collectedHeap.hpp"
-#include "gc/shared/collectorPolicy.hpp"
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
-#include "memory/allocation.hpp"
-#include "memory/binaryTreeDictionary.inline.hpp"
 #include "memory/filemap.hpp"
-#include "memory/freeList.inline.hpp"
-#include "memory/metachunk.hpp"
 #include "memory/metaspace.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metachunk.hpp"
 #include "memory/metaspace/metaspaceCommon.hpp"
-#include "memory/metaspace/metaspaceStatistics.hpp"
-#include "memory/metaspaceGCThresholdUpdater.hpp"
+#include "memory/metaspace/printCLDMetaspaceInfoClosure.hpp"
+#include "memory/metaspace/spaceManager.hpp"
+#include "memory/metaspace/virtualSpaceList.hpp"
 #include "memory/metaspaceShared.hpp"
 #include "memory/metaspaceTracer.hpp"
-#include "memory/resourceArea.hpp"
-#include "memory/universe.hpp"
-#include "runtime/atomic.hpp"
-#include "runtime/globals.hpp"
 #include "runtime/init.hpp"
-#include "runtime/java.hpp"
-#include "runtime/mutex.hpp"
-#include "runtime/mutexLocker.hpp"
 #include "runtime/orderAccess.inline.hpp"
 #include "services/memTracker.hpp"
-#include "services/memoryService.hpp"
-#include "utilities/align.hpp"
 #include "utilities/copy.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
-#include "utilities/macros.hpp"
 
-using namespace metaspace::internals;
 
-typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary;
-typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;
-
-// Helper function that does a bunch of checks for a chunk.
-DEBUG_ONLY(static void do_verify_chunk(Metachunk* chunk);)
-
-// Given a Metachunk, update its in-use information (both in the
-// chunk and the occupancy map).
-static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse);
-
-size_t const allocation_from_dictionary_limit = 4 * K;
+using namespace metaspace;
 
 MetaWord* last_allocated = 0;
 
@@ -76,103 +54,6 @@
 
 DEBUG_ONLY(bool Metaspace::_frozen = false;)
 
-// Internal statistics.
-#ifdef ASSERT
-static struct {
-  // Number of allocations.
-  uintx num_allocs;
-  // Number of times a ClassLoaderMetaspace was born...
-  uintx num_metaspace_births;
-  // ... and died.
-  uintx num_metaspace_deaths;
-  // Number of times VirtualSpaceListNodes were created...
-  uintx num_vsnodes_created;
-  // ... and purged.
-  uintx num_vsnodes_purged;
-  // Number of times we expanded the committed section of the space.
-  uintx num_committed_space_expanded;
-  // Number of deallocations
-  uintx num_deallocs;
-  // Number of deallocations triggered from outside ("real" deallocations).
-  uintx num_external_deallocs;
-  // Number of times an allocation was satisfied from deallocated blocks.
-  uintx num_allocs_from_deallocated_blocks;
-} g_internal_statistics;
-#endif
-
-enum ChunkSizes {    // in words.
-  ClassSpecializedChunk = 128,
-  SpecializedChunk = 128,
-  ClassSmallChunk = 256,
-  SmallChunk = 512,
-  ClassMediumChunk = 4 * K,
-  MediumChunk = 8 * K
-};
-
-// Returns size of this chunk type.
-size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunktype, bool is_class) {
-  assert(is_valid_nonhumongous_chunktype(chunktype), "invalid chunk type.");
-  size_t size = 0;
-  if (is_class) {
-    switch(chunktype) {
-      case SpecializedIndex: size = ClassSpecializedChunk; break;
-      case SmallIndex: size = ClassSmallChunk; break;
-      case MediumIndex: size = ClassMediumChunk; break;
-      default:
-        ShouldNotReachHere();
-    }
-  } else {
-    switch(chunktype) {
-      case SpecializedIndex: size = SpecializedChunk; break;
-      case SmallIndex: size = SmallChunk; break;
-      case MediumIndex: size = MediumChunk; break;
-      default:
-        ShouldNotReachHere();
-    }
-  }
-  return size;
-}
-
-ChunkIndex get_chunk_type_by_size(size_t size, bool is_class) {
-  if (is_class) {
-    if (size == ClassSpecializedChunk) {
-      return SpecializedIndex;
-    } else if (size == ClassSmallChunk) {
-      return SmallIndex;
-    } else if (size == ClassMediumChunk) {
-      return MediumIndex;
-    } else if (size > ClassMediumChunk) {
-      // A valid humongous chunk size is a multiple of the smallest chunk size.
-      assert(is_aligned(size, ClassSpecializedChunk), "Invalid chunk size");
-      return HumongousIndex;
-    }
-  } else {
-    if (size == SpecializedChunk) {
-      return SpecializedIndex;
-    } else if (size == SmallChunk) {
-      return SmallIndex;
-    } else if (size == MediumChunk) {
-      return MediumIndex;
-    } else if (size > MediumChunk) {
-      // A valid humongous chunk size is a multiple of the smallest chunk size.
-      assert(is_aligned(size, SpecializedChunk), "Invalid chunk size");
-      return HumongousIndex;
-    }
-  }
-  ShouldNotReachHere();
-  return (ChunkIndex)-1;
-}
-
-ChunkIndex next_chunk_index(ChunkIndex i) {
-  assert(i < NumberOfInUseLists, "Out of bound");
-  return (ChunkIndex) (i+1);
-}
-
-ChunkIndex prev_chunk_index(ChunkIndex i) {
-  assert(i > ZeroIndex, "Out of bound");
-  return (ChunkIndex) (i-1);
-}
-
 static const char* space_type_name(Metaspace::MetaspaceType t) {
   const char* s = NULL;
   switch (t) {
@@ -189,2176 +70,10 @@
 uint MetaspaceGC::_shrink_factor = 0;
 bool MetaspaceGC::_should_concurrent_collect = false;
 
-
-typedef class FreeList<Metachunk> ChunkList;
-
-// Manages the global free lists of chunks.
-class ChunkManager : public CHeapObj<mtInternal> {
-  friend class TestVirtualSpaceNodeTest;
-
-  // Free list of chunks of different sizes.
-  //   SpecializedChunk
-  //   SmallChunk
-  //   MediumChunk
-  ChunkList _free_chunks[NumberOfFreeLists];
-
-  // Whether or not this is the class chunkmanager.
-  const bool _is_class;
-
-  // Return non-humongous chunk list by its index.
-  ChunkList* free_chunks(ChunkIndex index);
-
-  // Returns non-humongous chunk list for the given chunk word size.
-  ChunkList* find_free_chunks_list(size_t word_size);
-
-  //   HumongousChunk
-  ChunkTreeDictionary _humongous_dictionary;
-
-  // Returns the humongous chunk dictionary.
-  ChunkTreeDictionary* humongous_dictionary() {
-    return &_humongous_dictionary;
-  }
-
-  // Size, in metaspace words, of all chunks managed by this ChunkManager
-  size_t _free_chunks_total;
-  // Number of chunks in this ChunkManager
-  size_t _free_chunks_count;
-
-  // Update counters after a chunk was added or removed removed.
-  void account_for_added_chunk(const Metachunk* c);
-  void account_for_removed_chunk(const Metachunk* c);
-
-  // Debug support
-
-  size_t sum_free_chunks();
-  size_t sum_free_chunks_count();
-
-  void locked_verify_free_chunks_total();
-  void slow_locked_verify_free_chunks_total() {
-    if (VerifyMetaspace) {
-      locked_verify_free_chunks_total();
-    }
-  }
-  void locked_verify_free_chunks_count();
-  void slow_locked_verify_free_chunks_count() {
-    if (VerifyMetaspace) {
-      locked_verify_free_chunks_count();
-    }
-  }
-
-  // Given a pointer to a chunk, attempts to merge it with neighboring
-  // free chunks to form a bigger chunk. Returns true if successful.
-  bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type);
-
-  // Helper for chunk merging:
-  //  Given an address range with 1-n chunks which are all supposed to be
-  //  free and hence currently managed by this ChunkManager, remove them
-  //  from this ChunkManager and mark them as invalid.
-  // - This does not correct the occupancy map.
-  // - This does not adjust the counters in ChunkManager.
-  // - Does not adjust container count counter in containing VirtualSpaceNode.
-  // Returns number of chunks removed.
-  int remove_chunks_in_area(MetaWord* p, size_t word_size);
-
-  // Helper for chunk splitting: given a target chunk size and a larger free chunk,
-  // split up the larger chunk into n smaller chunks, at least one of which should be
-  // the target chunk of target chunk size. The smaller chunks, including the target
-  // chunk, are returned to the freelist. The pointer to the target chunk is returned.
-  // Note that this chunk is supposed to be removed from the freelist right away.
-  Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk);
-
- public:
-
-  ChunkManager(bool is_class)
-      : _is_class(is_class), _free_chunks_total(0), _free_chunks_count(0) {
-    _free_chunks[SpecializedIndex].set_size(get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class));
-    _free_chunks[SmallIndex].set_size(get_size_for_nonhumongous_chunktype(SmallIndex, is_class));
-    _free_chunks[MediumIndex].set_size(get_size_for_nonhumongous_chunktype(MediumIndex, is_class));
-  }
-
-  // Add or delete (return) a chunk to the global freelist.
-  Metachunk* chunk_freelist_allocate(size_t word_size);
-
-  // Map a size to a list index assuming that there are lists
-  // for special, small, medium, and humongous chunks.
-  ChunkIndex list_index(size_t size);
-
-  // Map a given index to the chunk size.
-  size_t size_by_index(ChunkIndex index) const;
-
-  bool is_class() const { return _is_class; }
-
-  // Convenience accessors.
-  size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); }
-  size_t small_chunk_word_size() const { return size_by_index(SmallIndex); }
-  size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); }
-
-  // Take a chunk from the ChunkManager. The chunk is expected to be in
-  // the chunk manager (the freelist if non-humongous, the dictionary if
-  // humongous).
-  void remove_chunk(Metachunk* chunk);
-
-  // Return a single chunk of type index to the ChunkManager.
-  void return_single_chunk(Metachunk* chunk);
-
-  // Add the simple linked list of chunks to the freelist of chunks
-  // of type index.
-  void return_chunk_list(Metachunk* chunks);
-
-  // Total of the space in the free chunks list
-  size_t free_chunks_total_words();
-  size_t free_chunks_total_bytes();
-
-  // Number of chunks in the free chunks list
-  size_t free_chunks_count();
-
-  // Remove from a list by size.  Selects list based on size of chunk.
-  Metachunk* free_chunks_get(size_t chunk_word_size);
-
-#define index_bounds_check(index)                                         \
-  assert(is_valid_chunktype(index), "Bad index: %d", (int) index)
-
-  size_t num_free_chunks(ChunkIndex index) const {
-    index_bounds_check(index);
-
-    if (index == HumongousIndex) {
-      return _humongous_dictionary.total_free_blocks();
-    }
-
-    ssize_t count = _free_chunks[index].count();
-    return count == -1 ? 0 : (size_t) count;
-  }
-
-  size_t size_free_chunks_in_bytes(ChunkIndex index) const {
-    index_bounds_check(index);
-
-    size_t word_size = 0;
-    if (index == HumongousIndex) {
-      word_size = _humongous_dictionary.total_size();
-    } else {
-      const size_t size_per_chunk_in_words = _free_chunks[index].size();
-      word_size = size_per_chunk_in_words * num_free_chunks(index);
-    }
-
-    return word_size * BytesPerWord;
-  }
-
-  MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
-    return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
-                                         num_free_chunks(SmallIndex),
-                                         num_free_chunks(MediumIndex),
-                                         num_free_chunks(HumongousIndex),
-                                         size_free_chunks_in_bytes(SpecializedIndex),
-                                         size_free_chunks_in_bytes(SmallIndex),
-                                         size_free_chunks_in_bytes(MediumIndex),
-                                         size_free_chunks_in_bytes(HumongousIndex));
-  }
-
-  // Debug support
-  void verify();
-  void slow_verify() {
-    if (VerifyMetaspace) {
-      verify();
-    }
-  }
-  void locked_verify();
-  void slow_locked_verify() {
-    if (VerifyMetaspace) {
-      locked_verify();
-    }
-  }
-
-  void locked_print_free_chunks(outputStream* st);
-  void locked_print_sum_free_chunks(outputStream* st);
-
-  // Fill in current statistic values to the given statistics object.
-  void collect_statistics(ChunkManagerStatistics* out) const;
-
-};
-
-class SmallBlocks : public CHeapObj<mtClass> {
-  const static uint _small_block_max_size = sizeof(TreeChunk<Metablock,  FreeList<Metablock> >)/HeapWordSize;
-  // Note: this corresponds to the imposed miminum allocation size, see SpaceManager::get_allocation_word_size()
-  const static uint _small_block_min_size = sizeof(Metablock)/HeapWordSize;
-
- private:
-  FreeList<Metablock> _small_lists[_small_block_max_size - _small_block_min_size];
-
-  FreeList<Metablock>& list_at(size_t word_size) {
-    assert(word_size >= _small_block_min_size, "There are no metaspace objects less than %u words", _small_block_min_size);
-    return _small_lists[word_size - _small_block_min_size];
-  }
-
- public:
-  SmallBlocks() {
-    for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
-      uint k = i - _small_block_min_size;
-      _small_lists[k].set_size(i);
-    }
-  }
-
-  // Returns the total size, in words, of all blocks, across all block sizes.
-  size_t total_size() const {
-    size_t result = 0;
-    for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
-      uint k = i - _small_block_min_size;
-      result = result + _small_lists[k].count() * _small_lists[k].size();
-    }
-    return result;
-  }
-
-  // Returns the total number of all blocks across all block sizes.
-  uintx total_num_blocks() const {
-    uintx result = 0;
-    for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
-      uint k = i - _small_block_min_size;
-      result = result + _small_lists[k].count();
-    }
-    return result;
-  }
-
-  static uint small_block_max_size() { return _small_block_max_size; }
-  static uint small_block_min_size() { return _small_block_min_size; }
-
-  MetaWord* get_block(size_t word_size) {
-    if (list_at(word_size).count() > 0) {
-      MetaWord* new_block = (MetaWord*) list_at(word_size).get_chunk_at_head();
-      return new_block;
-    } else {
-      return NULL;
-    }
-  }
-  void return_block(Metablock* free_chunk, size_t word_size) {
-    list_at(word_size).return_chunk_at_head(free_chunk, false);
-    assert(list_at(word_size).count() > 0, "Should have a chunk");
-  }
-
-  void print_on(outputStream* st) const {
-    st->print_cr("SmallBlocks:");
-    for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
-      uint k = i - _small_block_min_size;
-      st->print_cr("small_lists size " SIZE_FORMAT " count " SIZE_FORMAT, _small_lists[k].size(), _small_lists[k].count());
-    }
-  }
-};
-
-// Used to manage the free list of Metablocks (a block corresponds
-// to the allocation of a quantum of metadata).
-class BlockFreelist : public CHeapObj<mtClass> {
-  BlockTreeDictionary* const _dictionary;
-  SmallBlocks* _small_blocks;
-
-  // Only allocate and split from freelist if the size of the allocation
-  // is at least 1/4th the size of the available block.
-  const static int WasteMultiplier = 4;
-
-  // Accessors
-  BlockTreeDictionary* dictionary() const { return _dictionary; }
-  SmallBlocks* small_blocks() {
-    if (_small_blocks == NULL) {
-      _small_blocks = new SmallBlocks();
-    }
-    return _small_blocks;
-  }
-
- public:
-  BlockFreelist();
-  ~BlockFreelist();
-
-  // Get and return a block to the free list
-  MetaWord* get_block(size_t word_size);
-  void return_block(MetaWord* p, size_t word_size);
-
-  // Returns the total size, in words, of all blocks kept in this structure.
-  size_t total_size() const  {
-    size_t result = dictionary()->total_size();
-    if (_small_blocks != NULL) {
-      result = result + _small_blocks->total_size();
-    }
-    return result;
-  }
-
-  // Returns the number of all blocks kept in this structure.
-  uintx num_blocks() const {
-    uintx result = dictionary()->total_free_blocks();
-    if (_small_blocks != NULL) {
-      result = result + _small_blocks->total_num_blocks();
-    }
-    return result;
-  }
-
-  static size_t min_dictionary_size()   { return TreeChunk<Metablock, FreeList<Metablock> >::min_size(); }
-  void print_on(outputStream* st) const;
-};
-
-// Helper for Occupancy Bitmap. A type trait to give an all-bits-are-one-unsigned constant.
-template <typename T> struct all_ones  { static const T value; };
-template <> struct all_ones <uint64_t> { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; };
-template <> struct all_ones <uint32_t> { static const uint32_t value = 0xFFFFFFFF; };
-
-// The OccupancyMap is a bitmap which, for a given VirtualSpaceNode,
-// keeps information about
-// - where a chunk starts
-// - whether a chunk is in-use or free
-// A bit in this bitmap represents one range of memory in the smallest
-// chunk size (SpecializedChunk or ClassSpecializedChunk).
-class OccupancyMap : public CHeapObj<mtInternal> {
-
-  // The address range this map covers.
-  const MetaWord* const _reference_address;
-  const size_t _word_size;
-
-  // The word size of a specialized chunk, aka the number of words one
-  // bit in this map represents.
-  const size_t _smallest_chunk_word_size;
-
-  // map data
-  // Data are organized in two bit layers:
-  // The first layer is the chunk-start-map. Here, a bit is set to mark
-  // the corresponding region as the head of a chunk.
-  // The second layer is the in-use-map. Here, a set bit indicates that
-  // the corresponding belongs to a chunk which is in use.
-  uint8_t* _map[2];
-
-  enum { layer_chunk_start_map = 0, layer_in_use_map = 1 };
-
-  // length, in bytes, of bitmap data
-  size_t _map_size;
-
-  // Returns true if bit at position pos at bit-layer layer is set.
-  bool get_bit_at_position(unsigned pos, unsigned layer) const {
-    assert(layer == 0 || layer == 1, "Invalid layer %d", layer);
-    const unsigned byteoffset = pos / 8;
-    assert(byteoffset < _map_size,
-           "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
-    const unsigned mask = 1 << (pos % 8);
-    return (_map[layer][byteoffset] & mask) > 0;
-  }
-
-  // Changes bit at position pos at bit-layer layer to value v.
-  void set_bit_at_position(unsigned pos, unsigned layer, bool v) {
-    assert(layer == 0 || layer == 1, "Invalid layer %d", layer);
-    const unsigned byteoffset = pos / 8;
-    assert(byteoffset < _map_size,
-           "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
-    const unsigned mask = 1 << (pos % 8);
-    if (v) {
-      _map[layer][byteoffset] |= mask;
-    } else {
-      _map[layer][byteoffset] &= ~mask;
-    }
-  }
-
-  // Optimized case of is_any_bit_set_in_region for 32/64bit aligned access:
-  // pos is 32/64 aligned and num_bits is 32/64.
-  // This is the typical case when coalescing to medium chunks, whose size is
-  // 32 or 64 times the specialized chunk size (depending on class or non class
-  // case), so they occupy 64 bits which should be 64bit aligned, because
-  // chunks are chunk-size aligned.
-  template <typename T>
-  bool is_any_bit_set_in_region_3264(unsigned pos, unsigned num_bits, unsigned layer) const {
-    assert(_map_size > 0, "not initialized");
-    assert(layer == 0 || layer == 1, "Invalid layer %d.", layer);
-    assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned (%u).", pos);
-    assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u).", num_bits);
-    const size_t byteoffset = pos / 8;
-    assert(byteoffset <= (_map_size - sizeof(T)),
-           "Invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
-    const T w = *(T*)(_map[layer] + byteoffset);
-    return w > 0 ? true : false;
-  }
-
-  // Returns true if any bit in region [pos1, pos1 + num_bits) is set in bit-layer layer.
-  bool is_any_bit_set_in_region(unsigned pos, unsigned num_bits, unsigned layer) const {
-    if (pos % 32 == 0 && num_bits == 32) {
-      return is_any_bit_set_in_region_3264<uint32_t>(pos, num_bits, layer);
-    } else if (pos % 64 == 0 && num_bits == 64) {
-      return is_any_bit_set_in_region_3264<uint64_t>(pos, num_bits, layer);
-    } else {
-      for (unsigned n = 0; n < num_bits; n ++) {
-        if (get_bit_at_position(pos + n, layer)) {
-          return true;
-        }
-      }
-    }
-    return false;
-  }
-
-  // Returns true if any bit in region [p, p+word_size) is set in bit-layer layer.
-  bool is_any_bit_set_in_region(MetaWord* p, size_t word_size, unsigned layer) const {
-    assert(word_size % _smallest_chunk_word_size == 0,
-        "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size);
-    const unsigned pos = get_bitpos_for_address(p);
-    const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size);
-    return is_any_bit_set_in_region(pos, num_bits, layer);
-  }
-
-  // Optimized case of set_bits_of_region for 32/64bit aligned access:
-  // pos is 32/64 aligned and num_bits is 32/64.
-  // This is the typical case when coalescing to medium chunks, whose size
-  // is 32 or 64 times the specialized chunk size (depending on class or non
-  // class case), so they occupy 64 bits which should be 64bit aligned,
-  // because chunks are chunk-size aligned.
-  template <typename T>
-  void set_bits_of_region_T(unsigned pos, unsigned num_bits, unsigned layer, bool v) {
-    assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned to %u (%u).",
-           (unsigned)(sizeof(T) * 8), pos);
-    assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u), expected %u.",
-           num_bits, (unsigned)(sizeof(T) * 8));
-    const size_t byteoffset = pos / 8;
-    assert(byteoffset <= (_map_size - sizeof(T)),
-           "invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
-    T* const pw = (T*)(_map[layer] + byteoffset);
-    *pw = v ? all_ones<T>::value : (T) 0;
-  }
-
-  // Set all bits in a region starting at pos to a value.
-  void set_bits_of_region(unsigned pos, unsigned num_bits, unsigned layer, bool v) {
-    assert(_map_size > 0, "not initialized");
-    assert(layer == 0 || layer == 1, "Invalid layer %d.", layer);
-    if (pos % 32 == 0 && num_bits == 32) {
-      set_bits_of_region_T<uint32_t>(pos, num_bits, layer, v);
-    } else if (pos % 64 == 0 && num_bits == 64) {
-      set_bits_of_region_T<uint64_t>(pos, num_bits, layer, v);
-    } else {
-      for (unsigned n = 0; n < num_bits; n ++) {
-        set_bit_at_position(pos + n, layer, v);
-      }
-    }
-  }
-
-  // Helper: sets all bits in a region [p, p+word_size).
-  void set_bits_of_region(MetaWord* p, size_t word_size, unsigned layer, bool v) {
-    assert(word_size % _smallest_chunk_word_size == 0,
-        "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size);
-    const unsigned pos = get_bitpos_for_address(p);
-    const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size);
-    set_bits_of_region(pos, num_bits, layer, v);
-  }
-
-  // Helper: given an address, return the bit position representing that address.
-  unsigned get_bitpos_for_address(const MetaWord* p) const {
-    assert(_reference_address != NULL, "not initialized");
-    assert(p >= _reference_address && p < _reference_address + _word_size,
-           "Address %p out of range for occupancy map [%p..%p).",
-            p, _reference_address, _reference_address + _word_size);
-    assert(is_aligned(p, _smallest_chunk_word_size * sizeof(MetaWord)),
-           "Address not aligned (%p).", p);
-    const ptrdiff_t d = (p - _reference_address) / _smallest_chunk_word_size;
-    assert(d >= 0 && (size_t)d < _map_size * 8, "Sanity.");
-    return (unsigned) d;
-  }
-
- public:
-
-  OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) :
-    _reference_address(reference_address), _word_size(word_size),
-    _smallest_chunk_word_size(smallest_chunk_word_size) {
-    assert(reference_address != NULL, "invalid reference address");
-    assert(is_aligned(reference_address, smallest_chunk_word_size),
-           "Reference address not aligned to smallest chunk size.");
-    assert(is_aligned(word_size, smallest_chunk_word_size),
-           "Word_size shall be a multiple of the smallest chunk size.");
-    // Calculate bitmap size: one bit per smallest_chunk_word_size'd area.
-    size_t num_bits = word_size / smallest_chunk_word_size;
-    _map_size = (num_bits + 7) / 8;
-    assert(_map_size * 8 >= num_bits, "sanity");
-    _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal);
-    _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal);
-    assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed.");
-    memset(_map[1], 0, _map_size);
-    memset(_map[0], 0, _map_size);
-    // Sanity test: the first respectively last possible chunk start address in
-    // the covered range shall map to the first and last bit in the bitmap.
-    assert(get_bitpos_for_address(reference_address) == 0,
-      "First chunk address in range must map to fist bit in bitmap.");
-    assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1,
-      "Last chunk address in range must map to last bit in bitmap.");
-  }
-
-  ~OccupancyMap() {
-    os::free(_map[0]);
-    os::free(_map[1]);
-  }
-
-  // Returns true if at address x a chunk is starting.
-  bool chunk_starts_at_address(MetaWord* p) const {
-    const unsigned pos = get_bitpos_for_address(p);
-    return get_bit_at_position(pos, layer_chunk_start_map);
-  }
-
-  void set_chunk_starts_at_address(MetaWord* p, bool v) {
-    const unsigned pos = get_bitpos_for_address(p);
-    set_bit_at_position(pos, layer_chunk_start_map, v);
-  }
-
-  // Removes all chunk-start-bits inside a region, typically as a
-  // result of a chunk merge.
-  void wipe_chunk_start_bits_in_region(MetaWord* p, size_t word_size) {
-    set_bits_of_region(p, word_size, layer_chunk_start_map, false);
-  }
-
-  // Returns true if there are life (in use) chunks in the region limited
-  // by [p, p+word_size).
-  bool is_region_in_use(MetaWord* p, size_t word_size) const {
-    return is_any_bit_set_in_region(p, word_size, layer_in_use_map);
-  }
-
-  // Marks the region starting at p with the size word_size as in use
-  // or free, depending on v.
-  void set_region_in_use(MetaWord* p, size_t word_size, bool v) {
-    set_bits_of_region(p, word_size, layer_in_use_map, v);
-  }
-
-#ifdef ASSERT
-  // Verify occupancy map for the address range [from, to).
-  // We need to tell it the address range, because the memory the
-  // occupancy map is covering may not be fully comitted yet.
-  void verify(MetaWord* from, MetaWord* to) {
-    Metachunk* chunk = NULL;
-    int nth_bit_for_chunk = 0;
-    MetaWord* chunk_end = NULL;
-    for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) {
-      const unsigned pos = get_bitpos_for_address(p);
-      // Check the chunk-starts-info:
-      if (get_bit_at_position(pos, layer_chunk_start_map)) {
-        // Chunk start marked in bitmap.
-        chunk = (Metachunk*) p;
-        if (chunk_end != NULL) {
-          assert(chunk_end == p, "Unexpected chunk start found at %p (expected "
-                 "the next chunk to start at %p).", p, chunk_end);
-        }
-        assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p);
-        if (chunk->get_chunk_type() != HumongousIndex) {
-          guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p);
-        }
-        chunk_end = p + chunk->word_size();
-        nth_bit_for_chunk = 0;
-        assert(chunk_end <= to, "Chunk end overlaps test address range.");
-      } else {
-        // No chunk start marked in bitmap.
-        assert(chunk != NULL, "Chunk should start at start of address range.");
-        assert(p < chunk_end, "Did not find expected chunk start at %p.", p);
-        nth_bit_for_chunk ++;
-      }
-      // Check the in-use-info:
-      const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map);
-      if (in_use_bit) {
-        assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).",
-               chunk, nth_bit_for_chunk);
-      } else {
-        assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).",
-               chunk, nth_bit_for_chunk);
-      }
-    }
-  }
-
-  // Verify that a given chunk is correctly accounted for in the bitmap.
-  void verify_for_chunk(Metachunk* chunk) {
-    assert(chunk_starts_at_address((MetaWord*) chunk),
-           "No chunk start marked in map for chunk %p.", chunk);
-    // For chunks larger than the minimal chunk size, no other chunk
-    // must start in its area.
-    if (chunk->word_size() > _smallest_chunk_word_size) {
-      assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size,
-                                       chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map),
-             "No chunk must start within another chunk.");
-    }
-    if (!chunk->is_tagged_free()) {
-      assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()),
-             "Chunk %p is in use but marked as free in map (%d %d).",
-             chunk, chunk->get_chunk_type(), chunk->get_origin());
-    } else {
-      assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()),
-             "Chunk %p is free but marked as in-use in map (%d %d).",
-             chunk, chunk->get_chunk_type(), chunk->get_origin());
-    }
-  }
-
-#endif // ASSERT
-
-};
-
-// A VirtualSpaceList node.
-class VirtualSpaceNode : public CHeapObj<mtClass> {
-  friend class VirtualSpaceList;
-
-  // Link to next VirtualSpaceNode
-  VirtualSpaceNode* _next;
-
-  // Whether this node is contained in class or metaspace.
-  const bool _is_class;
-
-  // total in the VirtualSpace
-  MemRegion _reserved;
-  ReservedSpace _rs;
-  VirtualSpace _virtual_space;
-  MetaWord* _top;
-  // count of chunks contained in this VirtualSpace
-  uintx _container_count;
-
-  OccupancyMap* _occupancy_map;
-
-  // Convenience functions to access the _virtual_space
-  char* low()  const { return virtual_space()->low(); }
-  char* high() const { return virtual_space()->high(); }
-
-  // The first Metachunk will be allocated at the bottom of the
-  // VirtualSpace
-  Metachunk* first_chunk() { return (Metachunk*) bottom(); }
-
-  // Committed but unused space in the virtual space
-  size_t free_words_in_vs() const;
-
-  // True if this node belongs to class metaspace.
-  bool is_class() const { return _is_class; }
-
-  // Helper function for take_from_committed: allocate padding chunks
-  // until top is at the given address.
-  void allocate_padding_chunks_until_top_is_at(MetaWord* target_top);
-
- public:
-
-  VirtualSpaceNode(bool is_class, size_t byte_size);
-  VirtualSpaceNode(bool is_class, ReservedSpace rs) :
-    _is_class(is_class), _top(NULL), _next(NULL), _rs(rs), _container_count(0), _occupancy_map(NULL) {}
-  ~VirtualSpaceNode();
-
-  // Convenience functions for logical bottom and end
-  MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
-  MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
-
-  const OccupancyMap* occupancy_map() const { return _occupancy_map; }
-  OccupancyMap* occupancy_map() { return _occupancy_map; }
-
-  bool contains(const void* ptr) { return ptr >= low() && ptr < high(); }
-
-  size_t reserved_words() const  { return _virtual_space.reserved_size() / BytesPerWord; }
-  size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; }
-
-  bool is_pre_committed() const { return _virtual_space.special(); }
-
-  // address of next available space in _virtual_space;
-  // Accessors
-  VirtualSpaceNode* next() { return _next; }
-  void set_next(VirtualSpaceNode* v) { _next = v; }
-
-  void set_reserved(MemRegion const v) { _reserved = v; }
-  void set_top(MetaWord* v) { _top = v; }
-
-  // Accessors
-  MemRegion* reserved() { return &_reserved; }
-  VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
-
-  // Returns true if "word_size" is available in the VirtualSpace
-  bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); }
-
-  MetaWord* top() const { return _top; }
-  void inc_top(size_t word_size) { _top += word_size; }
-
-  uintx container_count() { return _container_count; }
-  void inc_container_count();
-  void dec_container_count();
-#ifdef ASSERT
-  uintx container_count_slow();
-  void verify_container_count();
-#endif
-
-  // used and capacity in this single entry in the list
-  size_t used_words_in_vs() const;
-  size_t capacity_words_in_vs() const;
-
-  bool initialize();
-
-  // get space from the virtual space
-  Metachunk* take_from_committed(size_t chunk_word_size);
-
-  // Allocate a chunk from the virtual space and return it.
-  Metachunk* get_chunk_vs(size_t chunk_word_size);
-
-  // Expands/shrinks the committed space in a virtual space.  Delegates
-  // to Virtualspace
-  bool expand_by(size_t min_words, size_t preferred_words);
-
-  // In preparation for deleting this node, remove all the chunks
-  // in the node from any freelist.
-  void purge(ChunkManager* chunk_manager);
-
-  // If an allocation doesn't fit in the current node a new node is created.
-  // Allocate chunks out of the remaining committed space in this node
-  // to avoid wasting that memory.
-  // This always adds up because all the chunk sizes are multiples of
-  // the smallest chunk size.
-  void retire(ChunkManager* chunk_manager);
-
-
-  void print_on(outputStream* st) const                 { print_on(st, K); }
-  void print_on(outputStream* st, size_t scale) const;
-  void print_map(outputStream* st, bool is_class) const;
-
-  // Debug support
-  DEBUG_ONLY(void mangle();)
-  // Verify counters, all chunks in this list node and the occupancy map.
-  DEBUG_ONLY(void verify();)
-  // Verify that all free chunks in this node are ideally merged
-  // (there not should be multiple small chunks where a large chunk could exist.)
-  DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();)
-
-};
-
-#define assert_is_aligned(value, alignment)                  \
-  assert(is_aligned((value), (alignment)),                   \
-         SIZE_FORMAT_HEX " is not aligned to "               \
-         SIZE_FORMAT, (size_t)(uintptr_t)value, (alignment))
-
-#define assert_counter(expected_value, real_value, msg) \
-  assert( (expected_value) == (real_value),             \
-         "Counter mismatch (%s): expected " SIZE_FORMAT \
-         ", but got: " SIZE_FORMAT ".", msg, expected_value, \
-         real_value);
-
-// Decide if large pages should be committed when the memory is reserved.
-static bool should_commit_large_pages_when_reserving(size_t bytes) {
-  if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) {
-    size_t words = bytes / BytesPerWord;
-    bool is_class = false; // We never reserve large pages for the class space.
-    if (MetaspaceGC::can_expand(words, is_class) &&
-        MetaspaceGC::allowed_expansion() >= words) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-  // byte_size is the size of the associated virtualspace.
-VirtualSpaceNode::VirtualSpaceNode(bool is_class, size_t bytes) :
-  _is_class(is_class), _top(NULL), _next(NULL), _rs(), _container_count(0), _occupancy_map(NULL) {
-  assert_is_aligned(bytes, Metaspace::reserve_alignment());
-  bool large_pages = should_commit_large_pages_when_reserving(bytes);
-  _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
-
-  if (_rs.is_reserved()) {
-    assert(_rs.base() != NULL, "Catch if we get a NULL address");
-    assert(_rs.size() != 0, "Catch if we get a 0 size");
-    assert_is_aligned(_rs.base(), Metaspace::reserve_alignment());
-    assert_is_aligned(_rs.size(), Metaspace::reserve_alignment());
-
-    MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
-  }
-}
-
-void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
-  DEBUG_ONLY(this->verify();)
-  Metachunk* chunk = first_chunk();
-  Metachunk* invalid_chunk = (Metachunk*) top();
-  while (chunk < invalid_chunk ) {
-    assert(chunk->is_tagged_free(), "Should be tagged free");
-    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
-    chunk_manager->remove_chunk(chunk);
-    chunk->remove_sentinel();
-    assert(chunk->next() == NULL &&
-           chunk->prev() == NULL,
-           "Was not removed from its list");
-    chunk = (Metachunk*) next;
-  }
-}
-
-void VirtualSpaceNode::print_map(outputStream* st, bool is_class) const {
-
-  if (bottom() == top()) {
-    return;
-  }
-
-  const size_t spec_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk;
-  const size_t small_chunk_size = is_class ? ClassSmallChunk : SmallChunk;
-  const size_t med_chunk_size = is_class ? ClassMediumChunk : MediumChunk;
-
-  int line_len = 100;
-  const size_t section_len = align_up(spec_chunk_size * line_len, med_chunk_size);
-  line_len = (int)(section_len / spec_chunk_size);
-
-  static const int NUM_LINES = 4;
-
-  char* lines[NUM_LINES];
-  for (int i = 0; i < NUM_LINES; i ++) {
-    lines[i] = (char*)os::malloc(line_len, mtInternal);
-  }
-  int pos = 0;
-  const MetaWord* p = bottom();
-  const Metachunk* chunk = (const Metachunk*)p;
-  const MetaWord* chunk_end = p + chunk->word_size();
-  while (p < top()) {
-    if (pos == line_len) {
-      pos = 0;
-      for (int i = 0; i < NUM_LINES; i ++) {
-        st->fill_to(22);
-        st->print_raw(lines[i], line_len);
-        st->cr();
-      }
-    }
-    if (pos == 0) {
-      st->print(PTR_FORMAT ":", p2i(p));
-    }
-    if (p == chunk_end) {
-      chunk = (Metachunk*)p;
-      chunk_end = p + chunk->word_size();
-    }
-    // line 1: chunk starting points (a dot if that area is a chunk start).
-    lines[0][pos] = p == (const MetaWord*)chunk ? '.' : ' ';
-
-    // Line 2: chunk type (x=spec, s=small, m=medium, h=humongous), uppercase if
-    // chunk is in use.
-    const bool chunk_is_free = ((Metachunk*)chunk)->is_tagged_free();
-    if (chunk->word_size() == spec_chunk_size) {
-      lines[1][pos] = chunk_is_free ? 'x' : 'X';
-    } else if (chunk->word_size() == small_chunk_size) {
-      lines[1][pos] = chunk_is_free ? 's' : 'S';
-    } else if (chunk->word_size() == med_chunk_size) {
-      lines[1][pos] = chunk_is_free ? 'm' : 'M';
-    } else if (chunk->word_size() > med_chunk_size) {
-      lines[1][pos] = chunk_is_free ? 'h' : 'H';
-    } else {
-      ShouldNotReachHere();
-    }
-
-    // Line 3: chunk origin
-    const ChunkOrigin origin = chunk->get_origin();
-    lines[2][pos] = origin == origin_normal ? ' ' : '0' + (int) origin;
-
-    // Line 4: Virgin chunk? Virgin chunks are chunks created as a byproduct of padding or splitting,
-    //         but were never used.
-    lines[3][pos] = chunk->get_use_count() > 0 ? ' ' : 'v';
-
-    p += spec_chunk_size;
-    pos ++;
-  }
-  if (pos > 0) {
-    for (int i = 0; i < NUM_LINES; i ++) {
-      st->fill_to(22);
-      st->print_raw(lines[i], line_len);
-      st->cr();
-    }
-  }
-  for (int i = 0; i < NUM_LINES; i ++) {
-    os::free(lines[i]);
-  }
-}
-
-
-#ifdef ASSERT
-uintx VirtualSpaceNode::container_count_slow() {
-  uintx count = 0;
-  Metachunk* chunk = first_chunk();
-  Metachunk* invalid_chunk = (Metachunk*) top();
-  while (chunk < invalid_chunk ) {
-    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
-    do_verify_chunk(chunk);
-    // Don't count the chunks on the free lists.  Those are
-    // still part of the VirtualSpaceNode but not currently
-    // counted.
-    if (!chunk->is_tagged_free()) {
-      count++;
-    }
-    chunk = (Metachunk*) next;
-  }
-  return count;
-}
-#endif
-
-#ifdef ASSERT
-// Verify counters, all chunks in this list node and the occupancy map.
-void VirtualSpaceNode::verify() {
-  uintx num_in_use_chunks = 0;
-  Metachunk* chunk = first_chunk();
-  Metachunk* invalid_chunk = (Metachunk*) top();
-
-  // Iterate the chunks in this node and verify each chunk.
-  while (chunk < invalid_chunk ) {
-    DEBUG_ONLY(do_verify_chunk(chunk);)
-    if (!chunk->is_tagged_free()) {
-      num_in_use_chunks ++;
-    }
-    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
-    chunk = (Metachunk*) next;
-  }
-  assert(_container_count == num_in_use_chunks, "Container count mismatch (real: " UINTX_FORMAT
-         ", counter: " UINTX_FORMAT ".", num_in_use_chunks, _container_count);
-  // Also verify the occupancy map.
-  occupancy_map()->verify(this->bottom(), this->top());
-}
-#endif // ASSERT
-
-#ifdef ASSERT
-// Verify that all free chunks in this node are ideally merged
-// (there not should be multiple small chunks where a large chunk could exist.)
-void VirtualSpaceNode::verify_free_chunks_are_ideally_merged() {
-  Metachunk* chunk = first_chunk();
-  Metachunk* invalid_chunk = (Metachunk*) top();
-  // Shorthands.
-  const size_t size_med = (is_class() ? ClassMediumChunk : MediumChunk) * BytesPerWord;
-  const size_t size_small = (is_class() ? ClassSmallChunk : SmallChunk) * BytesPerWord;
-  int num_free_chunks_since_last_med_boundary = -1;
-  int num_free_chunks_since_last_small_boundary = -1;
-  while (chunk < invalid_chunk ) {
-    // Test for missed chunk merge opportunities: count number of free chunks since last chunk boundary.
-    // Reset the counter when encountering a non-free chunk.
-    if (chunk->get_chunk_type() != HumongousIndex) {
-      if (chunk->is_tagged_free()) {
-        // Count successive free, non-humongous chunks.
-        if (is_aligned(chunk, size_small)) {
-          assert(num_free_chunks_since_last_small_boundary <= 1,
-                 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_small, size_small);
-          num_free_chunks_since_last_small_boundary = 0;
-        } else if (num_free_chunks_since_last_small_boundary != -1) {
-          num_free_chunks_since_last_small_boundary ++;
-        }
-        if (is_aligned(chunk, size_med)) {
-          assert(num_free_chunks_since_last_med_boundary <= 1,
-                 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_med, size_med);
-          num_free_chunks_since_last_med_boundary = 0;
-        } else if (num_free_chunks_since_last_med_boundary != -1) {
-          num_free_chunks_since_last_med_boundary ++;
-        }
-      } else {
-        // Encountering a non-free chunk, reset counters.
-        num_free_chunks_since_last_med_boundary = -1;
-        num_free_chunks_since_last_small_boundary = -1;
-      }
-    } else {
-      // One cannot merge areas with a humongous chunk in the middle. Reset counters.
-      num_free_chunks_since_last_med_boundary = -1;
-      num_free_chunks_since_last_small_boundary = -1;
-    }
-
-    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
-    chunk = (Metachunk*) next;
-  }
-}
-#endif // ASSERT
-
-// List of VirtualSpaces for metadata allocation.
-class VirtualSpaceList : public CHeapObj<mtClass> {
-  friend class VirtualSpaceNode;
-
-  enum VirtualSpaceSizes {
-    VirtualSpaceSize = 256 * K
-  };
-
-  // Head of the list
-  VirtualSpaceNode* _virtual_space_list;
-  // virtual space currently being used for allocations
-  VirtualSpaceNode* _current_virtual_space;
-
-  // Is this VirtualSpaceList used for the compressed class space
-  bool _is_class;
-
-  // Sum of reserved and committed memory in the virtual spaces
-  size_t _reserved_words;
-  size_t _committed_words;
-
-  // Number of virtual spaces
-  size_t _virtual_space_count;
-
-  ~VirtualSpaceList();
-
-  VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
-
-  void set_virtual_space_list(VirtualSpaceNode* v) {
-    _virtual_space_list = v;
-  }
-  void set_current_virtual_space(VirtualSpaceNode* v) {
-    _current_virtual_space = v;
-  }
-
-  void link_vs(VirtualSpaceNode* new_entry);
-
-  // Get another virtual space and add it to the list.  This
-  // is typically prompted by a failed attempt to allocate a chunk
-  // and is typically followed by the allocation of a chunk.
-  bool create_new_virtual_space(size_t vs_word_size);
-
-  // Chunk up the unused committed space in the current
-  // virtual space and add the chunks to the free list.
-  void retire_current_virtual_space();
-
- public:
-  VirtualSpaceList(size_t word_size);
-  VirtualSpaceList(ReservedSpace rs);
-
-  size_t free_bytes();
-
-  Metachunk* get_new_chunk(size_t chunk_word_size,
-                           size_t suggested_commit_granularity);
-
-  bool expand_node_by(VirtualSpaceNode* node,
-                      size_t min_words,
-                      size_t preferred_words);
-
-  bool expand_by(size_t min_words,
-                 size_t preferred_words);
-
-  VirtualSpaceNode* current_virtual_space() {
-    return _current_virtual_space;
-  }
-
-  bool is_class() const { return _is_class; }
-
-  bool initialization_succeeded() { return _virtual_space_list != NULL; }
-
-  size_t reserved_words()  { return _reserved_words; }
-  size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
-  size_t committed_words() { return _committed_words; }
-  size_t committed_bytes() { return committed_words() * BytesPerWord; }
-
-  void inc_reserved_words(size_t v);
-  void dec_reserved_words(size_t v);
-  void inc_committed_words(size_t v);
-  void dec_committed_words(size_t v);
-  void inc_virtual_space_count();
-  void dec_virtual_space_count();
-
-  bool contains(const void* ptr);
-
-  // Unlink empty VirtualSpaceNodes and free it.
-  void purge(ChunkManager* chunk_manager);
-
-  void print_on(outputStream* st) const                 { print_on(st, K); }
-  void print_on(outputStream* st, size_t scale) const;
-  void print_map(outputStream* st) const;
-
-  class VirtualSpaceListIterator : public StackObj {
-    VirtualSpaceNode* _virtual_spaces;
-   public:
-    VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
-      _virtual_spaces(virtual_spaces) {}
-
-    bool repeat() {
-      return _virtual_spaces != NULL;
-    }
-
-    VirtualSpaceNode* get_next() {
-      VirtualSpaceNode* result = _virtual_spaces;
-      if (_virtual_spaces != NULL) {
-        _virtual_spaces = _virtual_spaces->next();
-      }
-      return result;
-    }
-  };
-};
-
-class Metadebug : AllStatic {
-  // Debugging support for Metaspaces
-  static int _allocation_fail_alot_count;
-
- public:
-
-  static void init_allocation_fail_alot_count();
-#ifdef ASSERT
-  static bool test_metadata_failure();
-#endif
-};
-
-int Metadebug::_allocation_fail_alot_count = 0;
-
-
-//  SpaceManager - used by Metaspace to handle allocations
-class SpaceManager : public CHeapObj<mtClass> {
-  friend class ClassLoaderMetaspace;
-  friend class Metadebug;
-
- private:
-
-  // protects allocations
-  Mutex* const _lock;
-
-  // Type of metadata allocated.
-  const Metaspace::MetadataType   _mdtype;
-
-  // Type of metaspace
-  const Metaspace::MetaspaceType  _space_type;
-
-  // List of chunks in use by this SpaceManager.  Allocations
-  // are done from the current chunk.  The list is used for deallocating
-  // chunks when the SpaceManager is freed.
-  Metachunk* _chunk_list;
-  Metachunk* _current_chunk;
-
-  // Maximum number of small chunks to allocate to a SpaceManager
-  static uint const _small_chunk_limit;
-
-  // Maximum number of specialize chunks to allocate for anonymous and delegating
-  // metadata space to a SpaceManager
-  static uint const _anon_and_delegating_metadata_specialize_chunk_limit;
-
-  // Some running counters, but lets keep their number small to not add to much to
-  // the per-classloader footprint.
-  // Note: capacity = used + free + waste + overhead. We do not keep running counters for
-  // free and waste. Their sum can be deduced from the three other values.
-  size_t _overhead_words;
-  size_t _capacity_words;
-  size_t _used_words;
-  uintx _num_chunks_by_type[NumberOfInUseLists];
-
-  // Free lists of blocks are per SpaceManager since they
-  // are assumed to be in chunks in use by the SpaceManager
-  // and all chunks in use by a SpaceManager are freed when
-  // the class loader using the SpaceManager is collected.
-  BlockFreelist* _block_freelists;
-
- private:
-  // Accessors
-  Metachunk* chunk_list() const { return _chunk_list; }
-
-  BlockFreelist* block_freelists() const { return _block_freelists; }
-
-  Metaspace::MetadataType mdtype() { return _mdtype; }
-
-  VirtualSpaceList* vs_list()   const { return Metaspace::get_space_list(_mdtype); }
-  ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
-
-  Metachunk* current_chunk() const { return _current_chunk; }
-  void set_current_chunk(Metachunk* v) {
-    _current_chunk = v;
-  }
-
-  Metachunk* find_current_chunk(size_t word_size);
-
-  // Add chunk to the list of chunks in use
-  void add_chunk(Metachunk* v, bool make_current);
-  void retire_current_chunk();
-
-  Mutex* lock() const { return _lock; }
-
-  // Adds to the given statistic object. Expects to be locked with lock().
-  void add_to_statistics_locked(SpaceManagerStatistics* out) const;
-
-  // Verify internal counters against the current state. Expects to be locked with lock().
-  DEBUG_ONLY(void verify_metrics_locked() const;)
-
- public:
-  SpaceManager(Metaspace::MetadataType mdtype,
-               Metaspace::MetaspaceType space_type,
-               Mutex* lock);
-  ~SpaceManager();
-
-  enum ChunkMultiples {
-    MediumChunkMultiple = 4
-  };
-
-  static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; }
-  static size_t small_chunk_size(bool is_class)       { return is_class ? ClassSmallChunk : SmallChunk; }
-  static size_t medium_chunk_size(bool is_class)      { return is_class ? ClassMediumChunk : MediumChunk; }
-
-  static size_t smallest_chunk_size(bool is_class)    { return specialized_chunk_size(is_class); }
-
-  // Accessors
-  bool is_class() const { return _mdtype == Metaspace::ClassType; }
-
-  size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); }
-  size_t small_chunk_size()       const { return small_chunk_size(is_class()); }
-  size_t medium_chunk_size()      const { return medium_chunk_size(is_class()); }
-
-  size_t smallest_chunk_size()    const { return smallest_chunk_size(is_class()); }
-
-  size_t medium_chunk_bunch()     const { return medium_chunk_size() * MediumChunkMultiple; }
-
-  bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
-
-  size_t capacity_words() const     { return _capacity_words; }
-  size_t used_words() const         { return _used_words; }
-  size_t overhead_words() const     { return _overhead_words; }
-
-  // Adjust local, global counters after a new chunk has been added.
-  void account_for_new_chunk(const Metachunk* new_chunk);
-
-  // Adjust local, global counters after space has been allocated from the current chunk.
-  void account_for_allocation(size_t words);
-
-  // Adjust global counters just before the SpaceManager dies, after all its chunks
-  // have been returned to the freelist.
-  void account_for_spacemanager_death();
-
-  // Adjust the initial chunk size to match one of the fixed chunk list sizes,
-  // or return the unadjusted size if the requested size is humongous.
-  static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space);
-  size_t adjust_initial_chunk_size(size_t requested) const;
-
-  // Get the initial chunks size for this metaspace type.
-  size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const;
-
-  // Todo: remove this once we have counters by chunk type.
-  uintx num_chunks_by_type(ChunkIndex chunk_type) const       { return _num_chunks_by_type[chunk_type]; }
-
-  Metachunk* get_new_chunk(size_t chunk_word_size);
-
-  // Block allocation and deallocation.
-  // Allocates a block from the current chunk
-  MetaWord* allocate(size_t word_size);
-
-  // Helper for allocations
-  MetaWord* allocate_work(size_t word_size);
-
-  // Returns a block to the per manager freelist
-  void deallocate(MetaWord* p, size_t word_size);
-
-  // Based on the allocation size and a minimum chunk size,
-  // returned chunk size (for expanding space for chunk allocation).
-  size_t calc_chunk_size(size_t allocation_word_size);
-
-  // Called when an allocation from the current chunk fails.
-  // Gets a new chunk (may require getting a new virtual space),
-  // and allocates from that chunk.
-  MetaWord* grow_and_allocate(size_t word_size);
-
-  // Notify memory usage to MemoryService.
-  void track_metaspace_memory_usage();
-
-  // debugging support.
-
-  void print_on(outputStream* st) const;
-  void locked_print_chunks_in_use_on(outputStream* st) const;
-
-  void verify();
-  void verify_chunk_size(Metachunk* chunk);
-
-  // This adjusts the size given to be greater than the minimum allocation size in
-  // words for data in metaspace.  Esentially the minimum size is currently 3 words.
-  size_t get_allocation_word_size(size_t word_size) {
-    size_t byte_size = word_size * BytesPerWord;
-
-    size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
-    raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment());
-
-    size_t raw_word_size = raw_bytes_size / BytesPerWord;
-    assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
-
-    return raw_word_size;
-  }
-
-  // Adds to the given statistic object.
-  void add_to_statistics(SpaceManagerStatistics* out) const;
-
-  // Verify internal counters against the current state.
-  DEBUG_ONLY(void verify_metrics() const;)
-
-};
-
-uint const SpaceManager::_small_chunk_limit = 4;
-uint const SpaceManager::_anon_and_delegating_metadata_specialize_chunk_limit = 4;
-
-void VirtualSpaceNode::inc_container_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _container_count++;
-}
-
-void VirtualSpaceNode::dec_container_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _container_count--;
-}
-
-#ifdef ASSERT
-void VirtualSpaceNode::verify_container_count() {
-  assert(_container_count == container_count_slow(),
-         "Inconsistency in container_count _container_count " UINTX_FORMAT
-         " container_count_slow() " UINTX_FORMAT, _container_count, container_count_slow());
-}
-#endif
-
 // BlockFreelist methods
 
-BlockFreelist::BlockFreelist() : _dictionary(new BlockTreeDictionary()), _small_blocks(NULL) {}
-
-BlockFreelist::~BlockFreelist() {
-  delete _dictionary;
-  if (_small_blocks != NULL) {
-    delete _small_blocks;
-  }
-}
-
-void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
-  assert(word_size >= SmallBlocks::small_block_min_size(), "never return dark matter");
-
-  Metablock* free_chunk = ::new (p) Metablock(word_size);
-  if (word_size < SmallBlocks::small_block_max_size()) {
-    small_blocks()->return_block(free_chunk, word_size);
-  } else {
-  dictionary()->return_chunk(free_chunk);
-}
-  log_trace(gc, metaspace, freelist, blocks)("returning block at " INTPTR_FORMAT " size = "
-            SIZE_FORMAT, p2i(free_chunk), word_size);
-}
-
-MetaWord* BlockFreelist::get_block(size_t word_size) {
-  assert(word_size >= SmallBlocks::small_block_min_size(), "never get dark matter");
-
-  // Try small_blocks first.
-  if (word_size < SmallBlocks::small_block_max_size()) {
-    // Don't create small_blocks() until needed.  small_blocks() allocates the small block list for
-    // this space manager.
-    MetaWord* new_block = (MetaWord*) small_blocks()->get_block(word_size);
-    if (new_block != NULL) {
-      log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
-              p2i(new_block), word_size);
-      return new_block;
-    }
-  }
-
-  if (word_size < BlockFreelist::min_dictionary_size()) {
-    // If allocation in small blocks fails, this is Dark Matter.  Too small for dictionary.
-    return NULL;
-  }
-
-  Metablock* free_block = dictionary()->get_chunk(word_size);
-  if (free_block == NULL) {
-    return NULL;
-  }
-
-  const size_t block_size = free_block->size();
-  if (block_size > WasteMultiplier * word_size) {
-    return_block((MetaWord*)free_block, block_size);
-    return NULL;
-  }
-
-  MetaWord* new_block = (MetaWord*)free_block;
-  assert(block_size >= word_size, "Incorrect size of block from freelist");
-  const size_t unused = block_size - word_size;
-  if (unused >= SmallBlocks::small_block_min_size()) {
-    return_block(new_block + word_size, unused);
-  }
-
-  log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
-            p2i(new_block), word_size);
-  return new_block;
-}
-
-void BlockFreelist::print_on(outputStream* st) const {
-  dictionary()->print_free_lists(st);
-  if (_small_blocks != NULL) {
-    _small_blocks->print_on(st);
-  }
-}
-
 // VirtualSpaceNode methods
 
-VirtualSpaceNode::~VirtualSpaceNode() {
-  _rs.release();
-  if (_occupancy_map != NULL) {
-    delete _occupancy_map;
-  }
-#ifdef ASSERT
-  size_t word_size = sizeof(*this) / BytesPerWord;
-  Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
-#endif
-}
-
-size_t VirtualSpaceNode::used_words_in_vs() const {
-  return pointer_delta(top(), bottom(), sizeof(MetaWord));
-}
-
-// Space committed in the VirtualSpace
-size_t VirtualSpaceNode::capacity_words_in_vs() const {
-  return pointer_delta(end(), bottom(), sizeof(MetaWord));
-}
-
-size_t VirtualSpaceNode::free_words_in_vs() const {
-  return pointer_delta(end(), top(), sizeof(MetaWord));
-}
-
-// Given an address larger than top(), allocate padding chunks until top is at the given address.
-void VirtualSpaceNode::allocate_padding_chunks_until_top_is_at(MetaWord* target_top) {
-
-  assert(target_top > top(), "Sanity");
-
-  // Padding chunks are added to the freelist.
-  ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class());
-
-  // shorthands
-  const size_t spec_word_size = chunk_manager->specialized_chunk_word_size();
-  const size_t small_word_size = chunk_manager->small_chunk_word_size();
-  const size_t med_word_size = chunk_manager->medium_chunk_word_size();
-
-  while (top() < target_top) {
-
-    // We could make this coding more generic, but right now we only deal with two possible chunk sizes
-    // for padding chunks, so it is not worth it.
-    size_t padding_chunk_word_size = small_word_size;
-    if (is_aligned(top(), small_word_size * sizeof(MetaWord)) == false) {
-      assert_is_aligned(top(), spec_word_size * sizeof(MetaWord)); // Should always hold true.
-      padding_chunk_word_size = spec_word_size;
-    }
-    MetaWord* here = top();
-    assert_is_aligned(here, padding_chunk_word_size * sizeof(MetaWord));
-    inc_top(padding_chunk_word_size);
-
-    // Create new padding chunk.
-    ChunkIndex padding_chunk_type = get_chunk_type_by_size(padding_chunk_word_size, is_class());
-    assert(padding_chunk_type == SpecializedIndex || padding_chunk_type == SmallIndex, "sanity");
-
-    Metachunk* const padding_chunk =
-      ::new (here) Metachunk(padding_chunk_type, is_class(), padding_chunk_word_size, this);
-    assert(padding_chunk == (Metachunk*)here, "Sanity");
-    DEBUG_ONLY(padding_chunk->set_origin(origin_pad);)
-    log_trace(gc, metaspace, freelist)("Created padding chunk in %s at "
-                                       PTR_FORMAT ", size " SIZE_FORMAT_HEX ".",
-                                       (is_class() ? "class space " : "metaspace"),
-                                       p2i(padding_chunk), padding_chunk->word_size() * sizeof(MetaWord));
-
-    // Mark chunk start in occupancy map.
-    occupancy_map()->set_chunk_starts_at_address((MetaWord*)padding_chunk, true);
-
-    // Chunks are born as in-use (see MetaChunk ctor). So, before returning
-    // the padding chunk to its chunk manager, mark it as in use (ChunkManager
-    // will assert that).
-    do_update_in_use_info_for_chunk(padding_chunk, true);
-
-    // Return Chunk to freelist.
-    inc_container_count();
-    chunk_manager->return_single_chunk(padding_chunk);
-    // Please note: at this point, ChunkManager::return_single_chunk()
-    // may already have merged the padding chunk with neighboring chunks, so
-    // it may have vanished at this point. Do not reference the padding
-    // chunk beyond this point.
-  }
-
-  assert(top() == target_top, "Sanity");
-
-} // allocate_padding_chunks_until_top_is_at()
-
-// Allocates the chunk from the virtual space only.
-// This interface is also used internally for debugging.  Not all
-// chunks removed here are necessarily used for allocation.
-Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
-  // Non-humongous chunks are to be allocated aligned to their chunk
-  // size. So, start addresses of medium chunks are aligned to medium
-  // chunk size, those of small chunks to small chunk size and so
-  // forth. This facilitates merging of free chunks and reduces
-  // fragmentation. Chunk sizes are spec < small < medium, with each
-  // larger chunk size being a multiple of the next smaller chunk
-  // size.
-  // Because of this alignment, me may need to create a number of padding
-  // chunks. These chunks are created and added to the freelist.
-
-  // The chunk manager to which we will give our padding chunks.
-  ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class());
-
-  // shorthands
-  const size_t spec_word_size = chunk_manager->specialized_chunk_word_size();
-  const size_t small_word_size = chunk_manager->small_chunk_word_size();
-  const size_t med_word_size = chunk_manager->medium_chunk_word_size();
-
-  assert(chunk_word_size == spec_word_size || chunk_word_size == small_word_size ||
-         chunk_word_size >= med_word_size, "Invalid chunk size requested.");
-
-  // Chunk alignment (in bytes) == chunk size unless humongous.
-  // Humongous chunks are aligned to the smallest chunk size (spec).
-  const size_t required_chunk_alignment = (chunk_word_size > med_word_size ?
-                                           spec_word_size : chunk_word_size) * sizeof(MetaWord);
-
-  // Do we have enough space to create the requested chunk plus
-  // any padding chunks needed?
-  MetaWord* const next_aligned =
-    static_cast<MetaWord*>(align_up(top(), required_chunk_alignment));
-  if (!is_available((next_aligned - top()) + chunk_word_size)) {
-    return NULL;
-  }
-
-  // Before allocating the requested chunk, allocate padding chunks if necessary.
-  // We only need to do this for small or medium chunks: specialized chunks are the
-  // smallest size, hence always aligned. Homungous chunks are allocated unaligned
-  // (implicitly, also aligned to smallest chunk size).
-  if ((chunk_word_size == med_word_size || chunk_word_size == small_word_size) && next_aligned > top())  {
-    log_trace(gc, metaspace, freelist)("Creating padding chunks in %s between %p and %p...",
-        (is_class() ? "class space " : "metaspace"),
-        top(), next_aligned);
-    allocate_padding_chunks_until_top_is_at(next_aligned);
-    // Now, top should be aligned correctly.
-    assert_is_aligned(top(), required_chunk_alignment);
-  }
-
-  // Now, top should be aligned correctly.
-  assert_is_aligned(top(), required_chunk_alignment);
-
-  // Bottom of the new chunk
-  MetaWord* chunk_limit = top();
-  assert(chunk_limit != NULL, "Not safe to call this method");
-
-  // The virtual spaces are always expanded by the
-  // commit granularity to enforce the following condition.
-  // Without this the is_available check will not work correctly.
-  assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
-      "The committed memory doesn't match the expanded memory.");
-
-  if (!is_available(chunk_word_size)) {
-    LogTarget(Debug, gc, metaspace, freelist) lt;
-    if (lt.is_enabled()) {
-      LogStream ls(lt);
-      ls.print("VirtualSpaceNode::take_from_committed() not available " SIZE_FORMAT " words ", chunk_word_size);
-      // Dump some information about the virtual space that is nearly full
-      print_on(&ls);
-    }
-    return NULL;
-  }
-
-  // Take the space  (bump top on the current virtual space).
-  inc_top(chunk_word_size);
-
-  // Initialize the chunk
-  ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class());
-  Metachunk* result = ::new (chunk_limit) Metachunk(chunk_type, is_class(), chunk_word_size, this);
-  assert(result == (Metachunk*)chunk_limit, "Sanity");
-  occupancy_map()->set_chunk_starts_at_address((MetaWord*)result, true);
-  do_update_in_use_info_for_chunk(result, true);
-
-  inc_container_count();
-
-  if (VerifyMetaspace) {
-    DEBUG_ONLY(chunk_manager->locked_verify());
-    DEBUG_ONLY(this->verify());
-  }
-
-  DEBUG_ONLY(do_verify_chunk(result));
-
-  result->inc_use_count();
-
-  return result;
-}
-
-
-// Expand the virtual space (commit more of the reserved space)
-bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
-  size_t min_bytes = min_words * BytesPerWord;
-  size_t preferred_bytes = preferred_words * BytesPerWord;
-
-  size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
-
-  if (uncommitted < min_bytes) {
-    return false;
-  }
-
-  size_t commit = MIN2(preferred_bytes, uncommitted);
-  bool result = virtual_space()->expand_by(commit, false);
-
-  if (result) {
-    log_trace(gc, metaspace, freelist)("Expanded %s virtual space list node by " SIZE_FORMAT " words.",
-              (is_class() ? "class" : "non-class"), commit);
-    DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_committed_space_expanded));
-  } else {
-    log_trace(gc, metaspace, freelist)("Failed to expand %s virtual space list node by " SIZE_FORMAT " words.",
-              (is_class() ? "class" : "non-class"), commit);
-  }
-
-  assert(result, "Failed to commit memory");
-
-  return result;
-}
-
-Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  Metachunk* result = take_from_committed(chunk_word_size);
-  return result;
-}
-
-bool VirtualSpaceNode::initialize() {
-
-  if (!_rs.is_reserved()) {
-    return false;
-  }
-
-  // These are necessary restriction to make sure that the virtual space always
-  // grows in steps of Metaspace::commit_alignment(). If both base and size are
-  // aligned only the middle alignment of the VirtualSpace is used.
-  assert_is_aligned(_rs.base(), Metaspace::commit_alignment());
-  assert_is_aligned(_rs.size(), Metaspace::commit_alignment());
-
-  // ReservedSpaces marked as special will have the entire memory
-  // pre-committed. Setting a committed size will make sure that
-  // committed_size and actual_committed_size agrees.
-  size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
-
-  bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
-                                            Metaspace::commit_alignment());
-  if (result) {
-    assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
-        "Checking that the pre-committed memory was registered by the VirtualSpace");
-
-    set_top((MetaWord*)virtual_space()->low());
-    set_reserved(MemRegion((HeapWord*)_rs.base(),
-                 (HeapWord*)(_rs.base() + _rs.size())));
-
-    assert(reserved()->start() == (HeapWord*) _rs.base(),
-           "Reserved start was not set properly " PTR_FORMAT
-           " != " PTR_FORMAT, p2i(reserved()->start()), p2i(_rs.base()));
-    assert(reserved()->word_size() == _rs.size() / BytesPerWord,
-           "Reserved size was not set properly " SIZE_FORMAT
-           " != " SIZE_FORMAT, reserved()->word_size(),
-           _rs.size() / BytesPerWord);
-  }
-
-  // Initialize Occupancy Map.
-  const size_t smallest_chunk_size = is_class() ? ClassSpecializedChunk : SpecializedChunk;
-  _occupancy_map = new OccupancyMap(bottom(), reserved_words(), smallest_chunk_size);
-
-  return result;
-}
-
-void VirtualSpaceNode::print_on(outputStream* st, size_t scale) const {
-  size_t used_words = used_words_in_vs();
-  size_t commit_words = committed_words();
-  size_t res_words = reserved_words();
-  VirtualSpace* vs = virtual_space();
-
-  st->print("node @" PTR_FORMAT ": ", p2i(this));
-  st->print("reserved=");
-  print_scaled_words(st, res_words, scale);
-  st->print(", committed=");
-  print_scaled_words_and_percentage(st, commit_words, res_words, scale);
-  st->print(", used=");
-  print_scaled_words_and_percentage(st, used_words, res_words, scale);
-  st->cr();
-  st->print("   [" PTR_FORMAT ", " PTR_FORMAT ", "
-           PTR_FORMAT ", " PTR_FORMAT ")",
-           p2i(bottom()), p2i(top()), p2i(end()),
-           p2i(vs->high_boundary()));
-}
-
-#ifdef ASSERT
-void VirtualSpaceNode::mangle() {
-  size_t word_size = capacity_words_in_vs();
-  Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
-}
-#endif // ASSERT
-
-// VirtualSpaceList methods
-// Space allocated from the VirtualSpace
-
-VirtualSpaceList::~VirtualSpaceList() {
-  VirtualSpaceListIterator iter(virtual_space_list());
-  while (iter.repeat()) {
-    VirtualSpaceNode* vsl = iter.get_next();
-    delete vsl;
-  }
-}
-
-void VirtualSpaceList::inc_reserved_words(size_t v) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _reserved_words = _reserved_words + v;
-}
-void VirtualSpaceList::dec_reserved_words(size_t v) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _reserved_words = _reserved_words - v;
-}
-
-#define assert_committed_below_limit()                        \
-  assert(MetaspaceUtils::committed_bytes() <= MaxMetaspaceSize, \
-         "Too much committed memory. Committed: " SIZE_FORMAT \
-         " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
-          MetaspaceUtils::committed_bytes(), MaxMetaspaceSize);
-
-void VirtualSpaceList::inc_committed_words(size_t v) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _committed_words = _committed_words + v;
-
-  assert_committed_below_limit();
-}
-void VirtualSpaceList::dec_committed_words(size_t v) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _committed_words = _committed_words - v;
-
-  assert_committed_below_limit();
-}
-
-void VirtualSpaceList::inc_virtual_space_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _virtual_space_count++;
-}
-void VirtualSpaceList::dec_virtual_space_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _virtual_space_count--;
-}
-
-void ChunkManager::remove_chunk(Metachunk* chunk) {
-  size_t word_size = chunk->word_size();
-  ChunkIndex index = list_index(word_size);
-  if (index != HumongousIndex) {
-    free_chunks(index)->remove_chunk(chunk);
-  } else {
-    humongous_dictionary()->remove_chunk(chunk);
-  }
-
-  // Chunk has been removed from the chunks free list, update counters.
-  account_for_removed_chunk(chunk);
-}
-
-bool ChunkManager::attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  assert(chunk != NULL, "invalid chunk pointer");
-  // Check for valid merge combinations.
-  assert((chunk->get_chunk_type() == SpecializedIndex &&
-          (target_chunk_type == SmallIndex || target_chunk_type == MediumIndex)) ||
-         (chunk->get_chunk_type() == SmallIndex && target_chunk_type == MediumIndex),
-        "Invalid chunk merge combination.");
-
-  const size_t target_chunk_word_size =
-    get_size_for_nonhumongous_chunktype(target_chunk_type, this->is_class());
-
-  // [ prospective merge region )
-  MetaWord* const p_merge_region_start =
-    (MetaWord*) align_down(chunk, target_chunk_word_size * sizeof(MetaWord));
-  MetaWord* const p_merge_region_end =
-    p_merge_region_start + target_chunk_word_size;
-
-  // We need the VirtualSpaceNode containing this chunk and its occupancy map.
-  VirtualSpaceNode* const vsn = chunk->container();
-  OccupancyMap* const ocmap = vsn->occupancy_map();
-
-  // The prospective chunk merge range must be completely contained by the
-  // committed range of the virtual space node.
-  if (p_merge_region_start < vsn->bottom() || p_merge_region_end > vsn->top()) {
-    return false;
-  }
-
-  // Only attempt to merge this range if at its start a chunk starts and at its end
-  // a chunk ends. If a chunk (can only be humongous) straddles either start or end
-  // of that range, we cannot merge.
-  if (!ocmap->chunk_starts_at_address(p_merge_region_start)) {
-    return false;
-  }
-  if (p_merge_region_end < vsn->top() &&
-      !ocmap->chunk_starts_at_address(p_merge_region_end)) {
-    return false;
-  }
-
-  // Now check if the prospective merge area contains live chunks. If it does we cannot merge.
-  if (ocmap->is_region_in_use(p_merge_region_start, target_chunk_word_size)) {
-    return false;
-  }
-
-  // Success! Remove all chunks in this region...
-  log_trace(gc, metaspace, freelist)("%s: coalescing chunks in area [%p-%p)...",
-    (is_class() ? "class space" : "metaspace"),
-    p_merge_region_start, p_merge_region_end);
-
-  const int num_chunks_removed =
-    remove_chunks_in_area(p_merge_region_start, target_chunk_word_size);
-
-  // ... and create a single new bigger chunk.
-  Metachunk* const p_new_chunk =
-      ::new (p_merge_region_start) Metachunk(target_chunk_type, is_class(), target_chunk_word_size, vsn);
-  assert(p_new_chunk == (Metachunk*)p_merge_region_start, "Sanity");
-  p_new_chunk->set_origin(origin_merge);
-
-  log_trace(gc, metaspace, freelist)("%s: created coalesced chunk at %p, size " SIZE_FORMAT_HEX ".",
-    (is_class() ? "class space" : "metaspace"),
-    p_new_chunk, p_new_chunk->word_size() * sizeof(MetaWord));
-
-  // Fix occupancy map: remove old start bits of the small chunks and set new start bit.
-  ocmap->wipe_chunk_start_bits_in_region(p_merge_region_start, target_chunk_word_size);
-  ocmap->set_chunk_starts_at_address(p_merge_region_start, true);
-
-  // Mark chunk as free. Note: it is not necessary to update the occupancy
-  // map in-use map, because the old chunks were also free, so nothing
-  // should have changed.
-  p_new_chunk->set_is_tagged_free(true);
-
-  // Add new chunk to its freelist.
-  ChunkList* const list = free_chunks(target_chunk_type);
-  list->return_chunk_at_head(p_new_chunk);
-
-  // And adjust ChunkManager:: _free_chunks_count (_free_chunks_total
-  // should not have changed, because the size of the space should be the same)
-  _free_chunks_count -= num_chunks_removed;
-  _free_chunks_count ++;
-
-  // VirtualSpaceNode::container_count does not have to be modified:
-  // it means "number of active (non-free) chunks", so merging free chunks
-  // should not affect that count.
-
-  // At the end of a chunk merge, run verification tests.
-  if (VerifyMetaspace) {
-    DEBUG_ONLY(this->locked_verify());
-    DEBUG_ONLY(vsn->verify());
-  }
-
-  return true;
-}
-
-// Remove all chunks in the given area - the chunks are supposed to be free -
-// from their corresponding freelists. Mark them as invalid.
-// - This does not correct the occupancy map.
-// - This does not adjust the counters in ChunkManager.
-// - Does not adjust container count counter in containing VirtualSpaceNode
-// Returns number of chunks removed.
-int ChunkManager::remove_chunks_in_area(MetaWord* p, size_t word_size) {
-  assert(p != NULL && word_size > 0, "Invalid range.");
-  const size_t smallest_chunk_size = get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class());
-  assert_is_aligned(word_size, smallest_chunk_size);
-
-  Metachunk* const start = (Metachunk*) p;
-  const Metachunk* const end = (Metachunk*)(p + word_size);
-  Metachunk* cur = start;
-  int num_removed = 0;
-  while (cur < end) {
-    Metachunk* next = (Metachunk*)(((MetaWord*)cur) + cur->word_size());
-    DEBUG_ONLY(do_verify_chunk(cur));
-    assert(cur->get_chunk_type() != HumongousIndex, "Unexpected humongous chunk found at %p.", cur);
-    assert(cur->is_tagged_free(), "Chunk expected to be free (%p)", cur);
-    log_trace(gc, metaspace, freelist)("%s: removing chunk %p, size " SIZE_FORMAT_HEX ".",
-      (is_class() ? "class space" : "metaspace"),
-      cur, cur->word_size() * sizeof(MetaWord));
-    cur->remove_sentinel();
-    // Note: cannot call ChunkManager::remove_chunk, because that
-    // modifies the counters in ChunkManager, which we do not want. So
-    // we call remove_chunk on the freelist directly (see also the
-    // splitting function which does the same).
-    ChunkList* const list = free_chunks(list_index(cur->word_size()));
-    list->remove_chunk(cur);
-    num_removed ++;
-    cur = next;
-  }
-  return num_removed;
-}
-
-// Walk the list of VirtualSpaceNodes and delete
-// nodes with a 0 container_count.  Remove Metachunks in
-// the node from their respective freelists.
-void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
-  assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work");
-  assert_lock_strong(MetaspaceExpand_lock);
-  // Don't use a VirtualSpaceListIterator because this
-  // list is being changed and a straightforward use of an iterator is not safe.
-  VirtualSpaceNode* purged_vsl = NULL;
-  VirtualSpaceNode* prev_vsl = virtual_space_list();
-  VirtualSpaceNode* next_vsl = prev_vsl;
-  while (next_vsl != NULL) {
-    VirtualSpaceNode* vsl = next_vsl;
-    DEBUG_ONLY(vsl->verify_container_count();)
-    next_vsl = vsl->next();
-    // Don't free the current virtual space since it will likely
-    // be needed soon.
-    if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
-      log_trace(gc, metaspace, freelist)("Purging VirtualSpaceNode " PTR_FORMAT " (capacity: " SIZE_FORMAT
-                                         ", used: " SIZE_FORMAT ").", p2i(vsl), vsl->capacity_words_in_vs(), vsl->used_words_in_vs());
-      DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_purged));
-      // Unlink it from the list
-      if (prev_vsl == vsl) {
-        // This is the case of the current node being the first node.
-        assert(vsl == virtual_space_list(), "Expected to be the first node");
-        set_virtual_space_list(vsl->next());
-      } else {
-        prev_vsl->set_next(vsl->next());
-      }
-
-      vsl->purge(chunk_manager);
-      dec_reserved_words(vsl->reserved_words());
-      dec_committed_words(vsl->committed_words());
-      dec_virtual_space_count();
-      purged_vsl = vsl;
-      delete vsl;
-    } else {
-      prev_vsl = vsl;
-    }
-  }
-#ifdef ASSERT
-  if (purged_vsl != NULL) {
-    // List should be stable enough to use an iterator here.
-    VirtualSpaceListIterator iter(virtual_space_list());
-    while (iter.repeat()) {
-      VirtualSpaceNode* vsl = iter.get_next();
-      assert(vsl != purged_vsl, "Purge of vsl failed");
-    }
-  }
-#endif
-}
-
-
-// This function looks at the mmap regions in the metaspace without locking.
-// The chunks are added with store ordering and not deleted except for at
-// unloading time during a safepoint.
-bool VirtualSpaceList::contains(const void* ptr) {
-  // List should be stable enough to use an iterator here because removing virtual
-  // space nodes is only allowed at a safepoint.
-  VirtualSpaceListIterator iter(virtual_space_list());
-  while (iter.repeat()) {
-    VirtualSpaceNode* vsn = iter.get_next();
-    if (vsn->contains(ptr)) {
-      return true;
-    }
-  }
-  return false;
-}
-
-void VirtualSpaceList::retire_current_virtual_space() {
-  assert_lock_strong(MetaspaceExpand_lock);
-
-  VirtualSpaceNode* vsn = current_virtual_space();
-
-  ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() :
-                                  Metaspace::chunk_manager_metadata();
-
-  vsn->retire(cm);
-}
-
-void VirtualSpaceNode::retire(ChunkManager* chunk_manager) {
-  DEBUG_ONLY(verify_container_count();)
-  assert(this->is_class() == chunk_manager->is_class(), "Wrong ChunkManager?");
-  for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) {
-    ChunkIndex index = (ChunkIndex)i;
-    size_t chunk_size = chunk_manager->size_by_index(index);
-
-    while (free_words_in_vs() >= chunk_size) {
-      Metachunk* chunk = get_chunk_vs(chunk_size);
-      // Chunk will be allocated aligned, so allocation may require
-      // additional padding chunks. That may cause above allocation to
-      // fail. Just ignore the failed allocation and continue with the
-      // next smaller chunk size. As the VirtualSpaceNode comitted
-      // size should be a multiple of the smallest chunk size, we
-      // should always be able to fill the VirtualSpace completely.
-      if (chunk == NULL) {
-        break;
-      }
-      chunk_manager->return_single_chunk(chunk);
-    }
-    DEBUG_ONLY(verify_container_count();)
-  }
-  assert(free_words_in_vs() == 0, "should be empty now");
-}
-
-VirtualSpaceList::VirtualSpaceList(size_t word_size) :
-                                   _is_class(false),
-                                   _virtual_space_list(NULL),
-                                   _current_virtual_space(NULL),
-                                   _reserved_words(0),
-                                   _committed_words(0),
-                                   _virtual_space_count(0) {
-  MutexLockerEx cl(MetaspaceExpand_lock,
-                   Mutex::_no_safepoint_check_flag);
-  create_new_virtual_space(word_size);
-}
-
-VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
-                                   _is_class(true),
-                                   _virtual_space_list(NULL),
-                                   _current_virtual_space(NULL),
-                                   _reserved_words(0),
-                                   _committed_words(0),
-                                   _virtual_space_count(0) {
-  MutexLockerEx cl(MetaspaceExpand_lock,
-                   Mutex::_no_safepoint_check_flag);
-  VirtualSpaceNode* class_entry = new VirtualSpaceNode(is_class(), rs);
-  bool succeeded = class_entry->initialize();
-  if (succeeded) {
-    link_vs(class_entry);
-  }
-}
-
-size_t VirtualSpaceList::free_bytes() {
-  return current_virtual_space()->free_words_in_vs() * BytesPerWord;
-}
-
-// Allocate another meta virtual space and add it to the list.
-bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
-  assert_lock_strong(MetaspaceExpand_lock);
-
-  if (is_class()) {
-    assert(false, "We currently don't support more than one VirtualSpace for"
-                  " the compressed class space. The initialization of the"
-                  " CCS uses another code path and should not hit this path.");
-    return false;
-  }
-
-  if (vs_word_size == 0) {
-    assert(false, "vs_word_size should always be at least _reserve_alignment large.");
-    return false;
-  }
-
-  // Reserve the space
-  size_t vs_byte_size = vs_word_size * BytesPerWord;
-  assert_is_aligned(vs_byte_size, Metaspace::reserve_alignment());
-
-  // Allocate the meta virtual space and initialize it.
-  VirtualSpaceNode* new_entry = new VirtualSpaceNode(is_class(), vs_byte_size);
-  if (!new_entry->initialize()) {
-    delete new_entry;
-    return false;
-  } else {
-    assert(new_entry->reserved_words() == vs_word_size,
-        "Reserved memory size differs from requested memory size");
-    // ensure lock-free iteration sees fully initialized node
-    OrderAccess::storestore();
-    link_vs(new_entry);
-    DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_created));
-    return true;
-  }
-}
-
-void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
-  if (virtual_space_list() == NULL) {
-      set_virtual_space_list(new_entry);
-  } else {
-    current_virtual_space()->set_next(new_entry);
-  }
-  set_current_virtual_space(new_entry);
-  inc_reserved_words(new_entry->reserved_words());
-  inc_committed_words(new_entry->committed_words());
-  inc_virtual_space_count();
-#ifdef ASSERT
-  new_entry->mangle();
-#endif
-  LogTarget(Trace, gc, metaspace) lt;
-  if (lt.is_enabled()) {
-    LogStream ls(lt);
-    VirtualSpaceNode* vsl = current_virtual_space();
-    ResourceMark rm;
-    vsl->print_on(&ls);
-  }
-}
-
-bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
-                                      size_t min_words,
-                                      size_t preferred_words) {
-  size_t before = node->committed_words();
-
-  bool result = node->expand_by(min_words, preferred_words);
-
-  size_t after = node->committed_words();
-
-  // after and before can be the same if the memory was pre-committed.
-  assert(after >= before, "Inconsistency");
-  inc_committed_words(after - before);
-
-  return result;
-}
-
-bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
-  assert_is_aligned(min_words,       Metaspace::commit_alignment_words());
-  assert_is_aligned(preferred_words, Metaspace::commit_alignment_words());
-  assert(min_words <= preferred_words, "Invalid arguments");
-
-  const char* const class_or_not = (is_class() ? "class" : "non-class");
-
-  if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
-    log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list.",
-              class_or_not);
-    return  false;
-  }
-
-  size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
-  if (allowed_expansion_words < min_words) {
-    log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list (must try gc first).",
-              class_or_not);
-    return false;
-  }
-
-  size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
-
-  // Commit more memory from the the current virtual space.
-  bool vs_expanded = expand_node_by(current_virtual_space(),
-                                    min_words,
-                                    max_expansion_words);
-  if (vs_expanded) {
-     log_trace(gc, metaspace, freelist)("Expanded %s virtual space list.",
-               class_or_not);
-     return true;
-  }
-  log_trace(gc, metaspace, freelist)("%s virtual space list: retire current node.",
-            class_or_not);
-  retire_current_virtual_space();
-
-  // Get another virtual space.
-  size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
-  grow_vs_words = align_up(grow_vs_words, Metaspace::reserve_alignment_words());
-
-  if (create_new_virtual_space(grow_vs_words)) {
-    if (current_virtual_space()->is_pre_committed()) {
-      // The memory was pre-committed, so we are done here.
-      assert(min_words <= current_virtual_space()->committed_words(),
-          "The new VirtualSpace was pre-committed, so it"
-          "should be large enough to fit the alloc request.");
-      return true;
-    }
-
-    return expand_node_by(current_virtual_space(),
-                          min_words,
-                          max_expansion_words);
-  }
-
-  return false;
-}
-
-// Given a chunk, calculate the largest possible padding space which
-// could be required when allocating it.
-static size_t largest_possible_padding_size_for_chunk(size_t chunk_word_size, bool is_class) {
-  const ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class);
-  if (chunk_type != HumongousIndex) {
-    // Normal, non-humongous chunks are allocated at chunk size
-    // boundaries, so the largest padding space required would be that
-    // minus the smallest chunk size.
-    const size_t smallest_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk;
-    return chunk_word_size - smallest_chunk_size;
-  } else {
-    // Humongous chunks are allocated at smallest-chunksize
-    // boundaries, so there is no padding required.
-    return 0;
-  }
-}
-
-
-Metachunk* VirtualSpaceList::get_new_chunk(size_t chunk_word_size, size_t suggested_commit_granularity) {
-
-  // Allocate a chunk out of the current virtual space.
-  Metachunk* next = current_virtual_space()->get_chunk_vs(chunk_word_size);
-
-  if (next != NULL) {
-    return next;
-  }
-
-  // The expand amount is currently only determined by the requested sizes
-  // and not how much committed memory is left in the current virtual space.
-
-  // We must have enough space for the requested size and any
-  // additional reqired padding chunks.
-  const size_t size_for_padding = largest_possible_padding_size_for_chunk(chunk_word_size, this->is_class());
-
-  size_t min_word_size       = align_up(chunk_word_size + size_for_padding, Metaspace::commit_alignment_words());
-  size_t preferred_word_size = align_up(suggested_commit_granularity, Metaspace::commit_alignment_words());
-  if (min_word_size >= preferred_word_size) {
-    // Can happen when humongous chunks are allocated.
-    preferred_word_size = min_word_size;
-  }
-
-  bool expanded = expand_by(min_word_size, preferred_word_size);
-  if (expanded) {
-    next = current_virtual_space()->get_chunk_vs(chunk_word_size);
-    assert(next != NULL, "The allocation was expected to succeed after the expansion");
-  }
-
-   return next;
-}
-
-void VirtualSpaceList::print_on(outputStream* st, size_t scale) const {
-  st->print_cr(SIZE_FORMAT " nodes, current node: " PTR_FORMAT,
-      _virtual_space_count, p2i(_current_virtual_space));
-  VirtualSpaceListIterator iter(virtual_space_list());
-  while (iter.repeat()) {
-    st->cr();
-    VirtualSpaceNode* node = iter.get_next();
-    node->print_on(st, scale);
-  }
-}
-
-void VirtualSpaceList::print_map(outputStream* st) const {
-  VirtualSpaceNode* list = virtual_space_list();
-  VirtualSpaceListIterator iter(list);
-  unsigned i = 0;
-  while (iter.repeat()) {
-    st->print_cr("Node %u:", i);
-    VirtualSpaceNode* node = iter.get_next();
-    node->print_map(st, this->is_class());
-    i ++;
-  }
-}
-
 // MetaspaceGC methods
 
 // VM_CollectForMetadataAllocation is the vm operation used to GC.
@@ -2615,972 +330,6 @@
   }
 }
 
-// Metadebug methods
-
-void Metadebug::init_allocation_fail_alot_count() {
-  if (MetadataAllocationFailALot) {
-    _allocation_fail_alot_count =
-      1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
-  }
-}
-
-#ifdef ASSERT
-bool Metadebug::test_metadata_failure() {
-  if (MetadataAllocationFailALot &&
-      Threads::is_vm_complete()) {
-    if (_allocation_fail_alot_count > 0) {
-      _allocation_fail_alot_count--;
-    } else {
-      log_trace(gc, metaspace, freelist)("Metadata allocation failing for MetadataAllocationFailALot");
-      init_allocation_fail_alot_count();
-      return true;
-    }
-  }
-  return false;
-}
-#endif
-
-// ChunkManager methods
-size_t ChunkManager::free_chunks_total_words() {
-  return _free_chunks_total;
-}
-
-size_t ChunkManager::free_chunks_total_bytes() {
-  return free_chunks_total_words() * BytesPerWord;
-}
-
-// Update internal accounting after a chunk was added
-void ChunkManager::account_for_added_chunk(const Metachunk* c) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  _free_chunks_count ++;
-  _free_chunks_total += c->word_size();
-}
-
-// Update internal accounting after a chunk was removed
-void ChunkManager::account_for_removed_chunk(const Metachunk* c) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  assert(_free_chunks_count >= 1,
-    "ChunkManager::_free_chunks_count: about to go negative (" SIZE_FORMAT ").", _free_chunks_count);
-  assert(_free_chunks_total >= c->word_size(),
-    "ChunkManager::_free_chunks_total: about to go negative"
-     "(now: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ").", _free_chunks_total, c->word_size());
-  _free_chunks_count --;
-  _free_chunks_total -= c->word_size();
-}
-
-size_t ChunkManager::free_chunks_count() {
-#ifdef ASSERT
-  if (!UseConcMarkSweepGC && !MetaspaceExpand_lock->is_locked()) {
-    MutexLockerEx cl(MetaspaceExpand_lock,
-                     Mutex::_no_safepoint_check_flag);
-    // This lock is only needed in debug because the verification
-    // of the _free_chunks_totals walks the list of free chunks
-    slow_locked_verify_free_chunks_count();
-  }
-#endif
-  return _free_chunks_count;
-}
-
-ChunkIndex ChunkManager::list_index(size_t size) {
-  return get_chunk_type_by_size(size, is_class());
-}
-
-size_t ChunkManager::size_by_index(ChunkIndex index) const {
-  index_bounds_check(index);
-  assert(index != HumongousIndex, "Do not call for humongous chunks.");
-  return get_size_for_nonhumongous_chunktype(index, is_class());
-}
-
-void ChunkManager::locked_verify_free_chunks_total() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  assert(sum_free_chunks() == _free_chunks_total,
-         "_free_chunks_total " SIZE_FORMAT " is not the"
-         " same as sum " SIZE_FORMAT, _free_chunks_total,
-         sum_free_chunks());
-}
-
-void ChunkManager::locked_verify_free_chunks_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  assert(sum_free_chunks_count() == _free_chunks_count,
-         "_free_chunks_count " SIZE_FORMAT " is not the"
-         " same as sum " SIZE_FORMAT, _free_chunks_count,
-         sum_free_chunks_count());
-}
-
-void ChunkManager::verify() {
-  MutexLockerEx cl(MetaspaceExpand_lock,
-                     Mutex::_no_safepoint_check_flag);
-  locked_verify();
-}
-
-void ChunkManager::locked_verify() {
-  locked_verify_free_chunks_count();
-  locked_verify_free_chunks_total();
-  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
-    ChunkList* list = free_chunks(i);
-    if (list != NULL) {
-      Metachunk* chunk = list->head();
-      while (chunk) {
-        DEBUG_ONLY(do_verify_chunk(chunk);)
-        assert(chunk->is_tagged_free(), "Chunk should be tagged as free.");
-        chunk = chunk->next();
-      }
-    }
-  }
-}
-
-void ChunkManager::locked_print_free_chunks(outputStream* st) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
-                _free_chunks_total, _free_chunks_count);
-}
-
-void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
-                sum_free_chunks(), sum_free_chunks_count());
-}
-
-ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
-  assert(index == SpecializedIndex || index == SmallIndex || index == MediumIndex,
-         "Bad index: %d", (int)index);
-
-  return &_free_chunks[index];
-}
-
-// These methods that sum the free chunk lists are used in printing
-// methods that are used in product builds.
-size_t ChunkManager::sum_free_chunks() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  size_t result = 0;
-  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
-    ChunkList* list = free_chunks(i);
-
-    if (list == NULL) {
-      continue;
-    }
-
-    result = result + list->count() * list->size();
-  }
-  result = result + humongous_dictionary()->total_size();
-  return result;
-}
-
-size_t ChunkManager::sum_free_chunks_count() {
-  assert_lock_strong(MetaspaceExpand_lock);
-  size_t count = 0;
-  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
-    ChunkList* list = free_chunks(i);
-    if (list == NULL) {
-      continue;
-    }
-    count = count + list->count();
-  }
-  count = count + humongous_dictionary()->total_free_blocks();
-  return count;
-}
-
-ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
-  ChunkIndex index = list_index(word_size);
-  assert(index < HumongousIndex, "No humongous list");
-  return free_chunks(index);
-}
-
-// Helper for chunk splitting: given a target chunk size and a larger free chunk,
-// split up the larger chunk into n smaller chunks, at least one of which should be
-// the target chunk of target chunk size. The smaller chunks, including the target
-// chunk, are returned to the freelist. The pointer to the target chunk is returned.
-// Note that this chunk is supposed to be removed from the freelist right away.
-Metachunk* ChunkManager::split_chunk(size_t target_chunk_word_size, Metachunk* larger_chunk) {
-  assert(larger_chunk->word_size() > target_chunk_word_size, "Sanity");
-
-  const ChunkIndex larger_chunk_index = larger_chunk->get_chunk_type();
-  const ChunkIndex target_chunk_index = get_chunk_type_by_size(target_chunk_word_size, is_class());
-
-  MetaWord* const region_start = (MetaWord*)larger_chunk;
-  const size_t region_word_len = larger_chunk->word_size();
-  MetaWord* const region_end = region_start + region_word_len;
-  VirtualSpaceNode* const vsn = larger_chunk->container();
-  OccupancyMap* const ocmap = vsn->occupancy_map();
-
-  // Any larger non-humongous chunk size is a multiple of any smaller chunk size.
-  // Since non-humongous chunks are aligned to their chunk size, the larger chunk should start
-  // at an address suitable to place the smaller target chunk.
-  assert_is_aligned(region_start, target_chunk_word_size);
-
-  // Remove old chunk.
-  free_chunks(larger_chunk_index)->remove_chunk(larger_chunk);
-  larger_chunk->remove_sentinel();
-
-  // Prevent access to the old chunk from here on.
-  larger_chunk = NULL;
-  // ... and wipe it.
-  DEBUG_ONLY(memset(region_start, 0xfe, region_word_len * BytesPerWord));
-
-  // In its place create first the target chunk...
-  MetaWord* p = region_start;
-  Metachunk* target_chunk = ::new (p) Metachunk(target_chunk_index, is_class(), target_chunk_word_size, vsn);
-  assert(target_chunk == (Metachunk*)p, "Sanity");
-  target_chunk->set_origin(origin_split);
-
-  // Note: we do not need to mark its start in the occupancy map
-  // because it coincides with the old chunk start.
-
-  // Mark chunk as free and return to the freelist.
-  do_update_in_use_info_for_chunk(target_chunk, false);
-  free_chunks(target_chunk_index)->return_chunk_at_head(target_chunk);
-
-  // This chunk should now be valid and can be verified.
-  DEBUG_ONLY(do_verify_chunk(target_chunk));
-
-  // In the remaining space create the remainder chunks.
-  p += target_chunk->word_size();
-  assert(p < region_end, "Sanity");
-
-  while (p < region_end) {
-
-    // Find the largest chunk size which fits the alignment requirements at address p.
-    ChunkIndex this_chunk_index = prev_chunk_index(larger_chunk_index);
-    size_t this_chunk_word_size = 0;
-    for(;;) {
-      this_chunk_word_size = get_size_for_nonhumongous_chunktype(this_chunk_index, is_class());
-      if (is_aligned(p, this_chunk_word_size * BytesPerWord)) {
-        break;
-      } else {
-        this_chunk_index = prev_chunk_index(this_chunk_index);
-        assert(this_chunk_index >= target_chunk_index, "Sanity");
-      }
-    }
-
-    assert(this_chunk_word_size >= target_chunk_word_size, "Sanity");
-    assert(is_aligned(p, this_chunk_word_size * BytesPerWord), "Sanity");
-    assert(p + this_chunk_word_size <= region_end, "Sanity");
-
-    // Create splitting chunk.
-    Metachunk* this_chunk = ::new (p) Metachunk(this_chunk_index, is_class(), this_chunk_word_size, vsn);
-    assert(this_chunk == (Metachunk*)p, "Sanity");
-    this_chunk->set_origin(origin_split);
-    ocmap->set_chunk_starts_at_address(p, true);
-    do_update_in_use_info_for_chunk(this_chunk, false);
-
-    // This chunk should be valid and can be verified.
-    DEBUG_ONLY(do_verify_chunk(this_chunk));
-
-    // Return this chunk to freelist and correct counter.
-    free_chunks(this_chunk_index)->return_chunk_at_head(this_chunk);
-    _free_chunks_count ++;
-
-    log_trace(gc, metaspace, freelist)("Created chunk at " PTR_FORMAT ", word size "
-      SIZE_FORMAT_HEX " (%s), in split region [" PTR_FORMAT "..." PTR_FORMAT ").",
-      p2i(this_chunk), this_chunk->word_size(), chunk_size_name(this_chunk_index),
-      p2i(region_start), p2i(region_end));
-
-    p += this_chunk_word_size;
-
-  }
-
-  return target_chunk;
-}
-
-Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
-  assert_lock_strong(MetaspaceExpand_lock);
-
-  slow_locked_verify();
-
-  Metachunk* chunk = NULL;
-  bool we_did_split_a_chunk = false;
-
-  if (list_index(word_size) != HumongousIndex) {
-
-    ChunkList* free_list = find_free_chunks_list(word_size);
-    assert(free_list != NULL, "Sanity check");
-
-    chunk = free_list->head();
-
-    if (chunk == NULL) {
-      // Split large chunks into smaller chunks if there are no smaller chunks, just large chunks.
-      // This is the counterpart of the coalescing-upon-chunk-return.
-
-      ChunkIndex target_chunk_index = get_chunk_type_by_size(word_size, is_class());
-
-      // Is there a larger chunk we could split?
-      Metachunk* larger_chunk = NULL;
-      ChunkIndex larger_chunk_index = next_chunk_index(target_chunk_index);
-      while (larger_chunk == NULL && larger_chunk_index < NumberOfFreeLists) {
-        larger_chunk = free_chunks(larger_chunk_index)->head();
-        if (larger_chunk == NULL) {
-          larger_chunk_index = next_chunk_index(larger_chunk_index);
-        }
-      }
-
-      if (larger_chunk != NULL) {
-        assert(larger_chunk->word_size() > word_size, "Sanity");
-        assert(larger_chunk->get_chunk_type() == larger_chunk_index, "Sanity");
-
-        // We found a larger chunk. Lets split it up:
-        // - remove old chunk
-        // - in its place, create new smaller chunks, with at least one chunk
-        //   being of target size, the others sized as large as possible. This
-        //   is to make sure the resulting chunks are "as coalesced as possible"
-        //   (similar to VirtualSpaceNode::retire()).
-        // Note: during this operation both ChunkManager and VirtualSpaceNode
-        //  are temporarily invalid, so be careful with asserts.
-
-        log_trace(gc, metaspace, freelist)("%s: splitting chunk " PTR_FORMAT
-           ", word size " SIZE_FORMAT_HEX " (%s), to get a chunk of word size " SIZE_FORMAT_HEX " (%s)...",
-          (is_class() ? "class space" : "metaspace"), p2i(larger_chunk), larger_chunk->word_size(),
-          chunk_size_name(larger_chunk_index), word_size, chunk_size_name(target_chunk_index));
-
-        chunk = split_chunk(word_size, larger_chunk);
-
-        // This should have worked.
-        assert(chunk != NULL, "Sanity");
-        assert(chunk->word_size() == word_size, "Sanity");
-        assert(chunk->is_tagged_free(), "Sanity");
-
-        we_did_split_a_chunk = true;
-
-      }
-    }
-
-    if (chunk == NULL) {
-      return NULL;
-    }
-
-    // Remove the chunk as the head of the list.
-    free_list->remove_chunk(chunk);
-
-    log_trace(gc, metaspace, freelist)("ChunkManager::free_chunks_get: free_list: " PTR_FORMAT " chunks left: " SSIZE_FORMAT ".",
-                                       p2i(free_list), free_list->count());
-
-  } else {
-    chunk = humongous_dictionary()->get_chunk(word_size);
-
-    if (chunk == NULL) {
-      return NULL;
-    }
-
-    log_debug(gc, metaspace, alloc)("Free list allocate humongous chunk size " SIZE_FORMAT " for requested size " SIZE_FORMAT " waste " SIZE_FORMAT,
-                                    chunk->word_size(), word_size, chunk->word_size() - word_size);
-  }
-
-  // Chunk has been removed from the chunk manager; update counters.
-  account_for_removed_chunk(chunk);
-  do_update_in_use_info_for_chunk(chunk, true);
-  chunk->container()->inc_container_count();
-  chunk->inc_use_count();
-
-  // Remove it from the links to this freelist
-  chunk->set_next(NULL);
-  chunk->set_prev(NULL);
-
-  // Run some verifications (some more if we did a chunk split)
-#ifdef ASSERT
-  if (VerifyMetaspace) {
-    locked_verify();
-    VirtualSpaceNode* const vsn = chunk->container();
-    vsn->verify();
-    if (we_did_split_a_chunk) {
-      vsn->verify_free_chunks_are_ideally_merged();
-    }
-  }
-#endif
-
-  return chunk;
-}
-
-Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
-  assert_lock_strong(MetaspaceExpand_lock);
-  slow_locked_verify();
-
-  // Take from the beginning of the list
-  Metachunk* chunk = free_chunks_get(word_size);
-  if (chunk == NULL) {
-    return NULL;
-  }
-
-  assert((word_size <= chunk->word_size()) ||
-         (list_index(chunk->word_size()) == HumongousIndex),
-         "Non-humongous variable sized chunk");
-  LogTarget(Debug, gc, metaspace, freelist) lt;
-  if (lt.is_enabled()) {
-    size_t list_count;
-    if (list_index(word_size) < HumongousIndex) {
-      ChunkList* list = find_free_chunks_list(word_size);
-      list_count = list->count();
-    } else {
-      list_count = humongous_dictionary()->total_count();
-    }
-    LogStream ls(lt);
-    ls.print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk " PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
-             p2i(this), p2i(chunk), chunk->word_size(), list_count);
-    ResourceMark rm;
-    locked_print_free_chunks(&ls);
-  }
-
-  return chunk;
-}
-
-void ChunkManager::return_single_chunk(Metachunk* chunk) {
-  const ChunkIndex index = chunk->get_chunk_type();
-  assert_lock_strong(MetaspaceExpand_lock);
-  DEBUG_ONLY(do_verify_chunk(chunk);)
-  assert(chunk != NULL, "Expected chunk.");
-  assert(chunk->container() != NULL, "Container should have been set.");
-  assert(chunk->is_tagged_free() == false, "Chunk should be in use.");
-  index_bounds_check(index);
-
-  // Note: mangle *before* returning the chunk to the freelist or dictionary. It does not
-  // matter for the freelist (non-humongous chunks), but the humongous chunk dictionary
-  // keeps tree node pointers in the chunk payload area which mangle will overwrite.
-  DEBUG_ONLY(chunk->mangle(badMetaWordVal);)
-
-  if (index != HumongousIndex) {
-    // Return non-humongous chunk to freelist.
-    ChunkList* list = free_chunks(index);
-    assert(list->size() == chunk->word_size(), "Wrong chunk type.");
-    list->return_chunk_at_head(chunk);
-    log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " to freelist.",
-        chunk_size_name(index), p2i(chunk));
-  } else {
-    // Return humongous chunk to dictionary.
-    assert(chunk->word_size() > free_chunks(MediumIndex)->size(), "Wrong chunk type.");
-    assert(chunk->word_size() % free_chunks(SpecializedIndex)->size() == 0,
-           "Humongous chunk has wrong alignment.");
-    _humongous_dictionary.return_chunk(chunk);
-    log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " (word size " SIZE_FORMAT ") to freelist.",
-        chunk_size_name(index), p2i(chunk), chunk->word_size());
-  }
-  chunk->container()->dec_container_count();
-  do_update_in_use_info_for_chunk(chunk, false);
-
-  // Chunk has been added; update counters.
-  account_for_added_chunk(chunk);
-
-  // Attempt coalesce returned chunks with its neighboring chunks:
-  // if this chunk is small or special, attempt to coalesce to a medium chunk.
-  if (index == SmallIndex || index == SpecializedIndex) {
-    if (!attempt_to_coalesce_around_chunk(chunk, MediumIndex)) {
-      // This did not work. But if this chunk is special, we still may form a small chunk?
-      if (index == SpecializedIndex) {
-        if (!attempt_to_coalesce_around_chunk(chunk, SmallIndex)) {
-          // give up.
-        }
-      }
-    }
-  }
-
-}
-
-void ChunkManager::return_chunk_list(Metachunk* chunks) {
-  if (chunks == NULL) {
-    return;
-  }
-  LogTarget(Trace, gc, metaspace, freelist) log;
-  if (log.is_enabled()) { // tracing
-    log.print("returning list of chunks...");
-  }
-  unsigned num_chunks_returned = 0;
-  size_t size_chunks_returned = 0;
-  Metachunk* cur = chunks;
-  while (cur != NULL) {
-    // Capture the next link before it is changed
-    // by the call to return_chunk_at_head();
-    Metachunk* next = cur->next();
-    if (log.is_enabled()) { // tracing
-      num_chunks_returned ++;
-      size_chunks_returned += cur->word_size();
-    }
-    return_single_chunk(cur);
-    cur = next;
-  }
-  if (log.is_enabled()) { // tracing
-    log.print("returned %u chunks to freelist, total word size " SIZE_FORMAT ".",
-        num_chunks_returned, size_chunks_returned);
-  }
-}
-
-void ChunkManager::collect_statistics(ChunkManagerStatistics* out) const {
-  MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
-  for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
-    out->chunk_stats(i).add(num_free_chunks(i), size_free_chunks_in_bytes(i) / sizeof(MetaWord));
-  }
-}
-
-// SpaceManager methods
-
-size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) {
-  size_t chunk_sizes[] = {
-      specialized_chunk_size(is_class_space),
-      small_chunk_size(is_class_space),
-      medium_chunk_size(is_class_space)
-  };
-
-  // Adjust up to one of the fixed chunk sizes ...
-  for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) {
-    if (requested <= chunk_sizes[i]) {
-      return chunk_sizes[i];
-    }
-  }
-
-  // ... or return the size as a humongous chunk.
-  return requested;
-}
-
-size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const {
-  return adjust_initial_chunk_size(requested, is_class());
-}
-
-size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const {
-  size_t requested;
-
-  if (is_class()) {
-    switch (type) {
-    case Metaspace::BootMetaspaceType:       requested = Metaspace::first_class_chunk_word_size(); break;
-    case Metaspace::AnonymousMetaspaceType:  requested = ClassSpecializedChunk; break;
-    case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break;
-    default:                                 requested = ClassSmallChunk; break;
-    }
-  } else {
-    switch (type) {
-    case Metaspace::BootMetaspaceType:       requested = Metaspace::first_chunk_word_size(); break;
-    case Metaspace::AnonymousMetaspaceType:  requested = SpecializedChunk; break;
-    case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break;
-    default:                                 requested = SmallChunk; break;
-    }
-  }
-
-  // Adjust to one of the fixed chunk sizes (unless humongous)
-  const size_t adjusted = adjust_initial_chunk_size(requested);
-
-  assert(adjusted != 0, "Incorrect initial chunk size. Requested: "
-         SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted);
-
-  return adjusted;
-}
-
-void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
-
-  for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
-    st->print("SpaceManager: " UINTX_FORMAT " %s chunks.",
-        num_chunks_by_type(i), chunk_size_name(i));
-  }
-
-  chunk_manager()->locked_print_free_chunks(st);
-}
-
-size_t SpaceManager::calc_chunk_size(size_t word_size) {
-
-  // Decide between a small chunk and a medium chunk.  Up to
-  // _small_chunk_limit small chunks can be allocated.
-  // After that a medium chunk is preferred.
-  size_t chunk_word_size;
-
-  // Special case for anonymous metadata space.
-  // Anonymous metadata space is usually small, with majority within 1K - 2K range and
-  // rarely about 4K (64-bits JVM).
-  // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation
-  // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4)
-  // reduces space waste from 60+% to around 30%.
-  if ((_space_type == Metaspace::AnonymousMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) &&
-      _mdtype == Metaspace::NonClassType &&
-      num_chunks_by_type(SpecializedIndex) < _anon_and_delegating_metadata_specialize_chunk_limit &&
-      word_size + Metachunk::overhead() <= SpecializedChunk) {
-    return SpecializedChunk;
-  }
-
-  if (num_chunks_by_type(MediumIndex) == 0 &&
-      num_chunks_by_type(SmallIndex) < _small_chunk_limit) {
-    chunk_word_size = (size_t) small_chunk_size();
-    if (word_size + Metachunk::overhead() > small_chunk_size()) {
-      chunk_word_size = medium_chunk_size();
-    }
-  } else {
-    chunk_word_size = medium_chunk_size();
-  }
-
-  // Might still need a humongous chunk.  Enforce
-  // humongous allocations sizes to be aligned up to
-  // the smallest chunk size.
-  size_t if_humongous_sized_chunk =
-    align_up(word_size + Metachunk::overhead(),
-                  smallest_chunk_size());
-  chunk_word_size =
-    MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
-
-  assert(!SpaceManager::is_humongous(word_size) ||
-         chunk_word_size == if_humongous_sized_chunk,
-         "Size calculation is wrong, word_size " SIZE_FORMAT
-         " chunk_word_size " SIZE_FORMAT,
-         word_size, chunk_word_size);
-  Log(gc, metaspace, alloc) log;
-  if (log.is_debug() && SpaceManager::is_humongous(word_size)) {
-    log.debug("Metadata humongous allocation:");
-    log.debug("  word_size " PTR_FORMAT, word_size);
-    log.debug("  chunk_word_size " PTR_FORMAT, chunk_word_size);
-    log.debug("    chunk overhead " PTR_FORMAT, Metachunk::overhead());
-  }
-  return chunk_word_size;
-}
-
-void SpaceManager::track_metaspace_memory_usage() {
-  if (is_init_completed()) {
-    if (is_class()) {
-      MemoryService::track_compressed_class_memory_usage();
-    }
-    MemoryService::track_metaspace_memory_usage();
-  }
-}
-
-MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
-  assert_lock_strong(_lock);
-  assert(vs_list()->current_virtual_space() != NULL,
-         "Should have been set");
-  assert(current_chunk() == NULL ||
-         current_chunk()->allocate(word_size) == NULL,
-         "Don't need to expand");
-  MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
-
-  if (log_is_enabled(Trace, gc, metaspace, freelist)) {
-    size_t words_left = 0;
-    size_t words_used = 0;
-    if (current_chunk() != NULL) {
-      words_left = current_chunk()->free_word_size();
-      words_used = current_chunk()->used_word_size();
-    }
-    log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left",
-                                       word_size, words_used, words_left);
-  }
-
-  // Get another chunk
-  size_t chunk_word_size = calc_chunk_size(word_size);
-  Metachunk* next = get_new_chunk(chunk_word_size);
-
-  MetaWord* mem = NULL;
-
-  // If a chunk was available, add it to the in-use chunk list
-  // and do an allocation from it.
-  if (next != NULL) {
-    // Add to this manager's list of chunks in use.
-    // If the new chunk is humongous, it was created to serve a single large allocation. In that
-    // case it usually makes no sense to make it the current chunk, since the next allocation would
-    // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly
-    // good chunk which could be used for more normal allocations.
-    bool make_current = true;
-    if (next->get_chunk_type() == HumongousIndex &&
-        current_chunk() != NULL) {
-      make_current = false;
-    }
-    add_chunk(next, make_current);
-    mem = next->allocate(word_size);
-  }
-
-  // Track metaspace memory usage statistic.
-  track_metaspace_memory_usage();
-
-  return mem;
-}
-
-void SpaceManager::print_on(outputStream* st) const {
-  SpaceManagerStatistics stat;
-  add_to_statistics(&stat); // will lock _lock.
-  stat.print_on(st, 1*K, false);
-}
-
-SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
-                           Metaspace::MetaspaceType space_type,
-                           Mutex* lock) :
-  _mdtype(mdtype),
-  _space_type(space_type),
-  _capacity_words(0),
-  _used_words(0),
-  _overhead_words(0),
-  _block_freelists(NULL),
-  _lock(lock),
-  _chunk_list(NULL),
-  _current_chunk(NULL)
-{
-  Metadebug::init_allocation_fail_alot_count();
-  memset(_num_chunks_by_type, 0, sizeof(_num_chunks_by_type));
-  log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this));
-}
-
-void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) {
-
-  assert_lock_strong(MetaspaceExpand_lock);
-
-  _capacity_words += new_chunk->word_size();
-  _overhead_words += Metachunk::overhead();
-  DEBUG_ONLY(new_chunk->verify());
-  _num_chunks_by_type[new_chunk->get_chunk_type()] ++;
-
-  // Adjust global counters:
-  MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size());
-  MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead());
-}
-
-void SpaceManager::account_for_allocation(size_t words) {
-  // Note: we should be locked with the ClassloaderData-specific metaspace lock.
-  // We may or may not be locked with the global metaspace expansion lock.
-  assert_lock_strong(lock());
-
-  // Add to the per SpaceManager totals. This can be done non-atomically.
-  _used_words += words;
-
-  // Adjust global counters. This will be done atomically.
-  MetaspaceUtils::inc_used(mdtype(), words);
-}
-
-void SpaceManager::account_for_spacemanager_death() {
-
-  assert_lock_strong(MetaspaceExpand_lock);
-
-  MetaspaceUtils::dec_capacity(mdtype(), _capacity_words);
-  MetaspaceUtils::dec_overhead(mdtype(), _overhead_words);
-  MetaspaceUtils::dec_used(mdtype(), _used_words);
-}
-
-SpaceManager::~SpaceManager() {
-
-  // This call this->_lock which can't be done while holding MetaspaceExpand_lock
-  DEBUG_ONLY(verify_metrics());
-
-  MutexLockerEx fcl(MetaspaceExpand_lock,
-                    Mutex::_no_safepoint_check_flag);
-
-  chunk_manager()->slow_locked_verify();
-
-  account_for_spacemanager_death();
-
-  Log(gc, metaspace, freelist) log;
-  if (log.is_trace()) {
-    log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this));
-    ResourceMark rm;
-    LogStream ls(log.trace());
-    locked_print_chunks_in_use_on(&ls);
-    if (block_freelists() != NULL) {
-      block_freelists()->print_on(&ls);
-    }
-  }
-
-  // Add all the chunks in use by this space manager
-  // to the global list of free chunks.
-
-  // Follow each list of chunks-in-use and add them to the
-  // free lists.  Each list is NULL terminated.
-  chunk_manager()->return_chunk_list(chunk_list());
-#ifdef ASSERT
-  _chunk_list = NULL;
-  _current_chunk = NULL;
-#endif
-
-  chunk_manager()->slow_locked_verify();
-
-  if (_block_freelists != NULL) {
-    delete _block_freelists;
-  }
-}
-
-void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
-  assert_lock_strong(lock());
-  // Allocations and deallocations are in raw_word_size
-  size_t raw_word_size = get_allocation_word_size(word_size);
-  // Lazily create a block_freelist
-  if (block_freelists() == NULL) {
-    _block_freelists = new BlockFreelist();
-  }
-  block_freelists()->return_block(p, raw_word_size);
-  DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_deallocs));
-}
-
-// Adds a chunk to the list of chunks in use.
-void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
-
-  assert_lock_strong(_lock);
-  assert(new_chunk != NULL, "Should not be NULL");
-  assert(new_chunk->next() == NULL, "Should not be on a list");
-
-  new_chunk->reset_empty();
-
-  // Find the correct list and and set the current
-  // chunk for that list.
-  ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size());
-
-  if (make_current) {
-    // If we are to make the chunk current, retire the old current chunk and replace
-    // it with the new chunk.
-    retire_current_chunk();
-    set_current_chunk(new_chunk);
-  }
-
-  // Add the new chunk at the head of its respective chunk list.
-  new_chunk->set_next(_chunk_list);
-  _chunk_list = new_chunk;
-
-  // Adjust counters.
-  account_for_new_chunk(new_chunk);
-
-  assert(new_chunk->is_empty(), "Not ready for reuse");
-  Log(gc, metaspace, freelist) log;
-  if (log.is_trace()) {
-    log.trace("SpaceManager::added chunk: ");
-    ResourceMark rm;
-    LogStream ls(log.trace());
-    new_chunk->print_on(&ls);
-    chunk_manager()->locked_print_free_chunks(&ls);
-  }
-}
-
-void SpaceManager::retire_current_chunk() {
-  if (current_chunk() != NULL) {
-    size_t remaining_words = current_chunk()->free_word_size();
-    if (remaining_words >= SmallBlocks::small_block_min_size()) {
-      MetaWord* ptr = current_chunk()->allocate(remaining_words);
-      deallocate(ptr, remaining_words);
-      account_for_allocation(remaining_words);
-    }
-  }
-}
-
-Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) {
-  // Get a chunk from the chunk freelist
-  Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size);
-
-  if (next == NULL) {
-    next = vs_list()->get_new_chunk(chunk_word_size,
-                                    medium_chunk_bunch());
-  }
-
-  Log(gc, metaspace, alloc) log;
-  if (log.is_debug() && next != NULL &&
-      SpaceManager::is_humongous(next->word_size())) {
-    log.debug("  new humongous chunk word size " PTR_FORMAT, next->word_size());
-  }
-
-  return next;
-}
-
-MetaWord* SpaceManager::allocate(size_t word_size) {
-  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
-  size_t raw_word_size = get_allocation_word_size(word_size);
-  BlockFreelist* fl =  block_freelists();
-  MetaWord* p = NULL;
-
-  DEBUG_ONLY(if (VerifyMetaspace) verify_metrics_locked());
-
-  // Allocation from the dictionary is expensive in the sense that
-  // the dictionary has to be searched for a size.  Don't allocate
-  // from the dictionary until it starts to get fat.  Is this
-  // a reasonable policy?  Maybe an skinny dictionary is fast enough
-  // for allocations.  Do some profiling.  JJJ
-  if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) {
-    p = fl->get_block(raw_word_size);
-    if (p != NULL) {
-      DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs_from_deallocated_blocks));
-    }
-  }
-  if (p == NULL) {
-    p = allocate_work(raw_word_size);
-  }
-
-  return p;
-}
-
-// Returns the address of spaced allocated for "word_size".
-// This methods does not know about blocks (Metablocks)
-MetaWord* SpaceManager::allocate_work(size_t word_size) {
-  assert_lock_strong(lock());
-#ifdef ASSERT
-  if (Metadebug::test_metadata_failure()) {
-    return NULL;
-  }
-#endif
-  // Is there space in the current chunk?
-  MetaWord* result = NULL;
-
-  if (current_chunk() != NULL) {
-    result = current_chunk()->allocate(word_size);
-  }
-
-  if (result == NULL) {
-    result = grow_and_allocate(word_size);
-  }
-
-  if (result != NULL) {
-    account_for_allocation(word_size);
-  }
-
-  return result;
-}
-
-void SpaceManager::verify() {
-  Metachunk* curr = chunk_list();
-  while (curr != NULL) {
-    DEBUG_ONLY(do_verify_chunk(curr);)
-    assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use.");
-    curr = curr->next();
-  }
-}
-
-void SpaceManager::verify_chunk_size(Metachunk* chunk) {
-  assert(is_humongous(chunk->word_size()) ||
-         chunk->word_size() == medium_chunk_size() ||
-         chunk->word_size() == small_chunk_size() ||
-         chunk->word_size() == specialized_chunk_size(),
-         "Chunk size is wrong");
-  return;
-}
-
-void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const {
-  assert_lock_strong(lock());
-  Metachunk* chunk = chunk_list();
-  while (chunk != NULL) {
-    UsedChunksStatistics& chunk_stat = out->chunk_stats(chunk->get_chunk_type());
-    chunk_stat.add_num(1);
-    chunk_stat.add_cap(chunk->word_size());
-    chunk_stat.add_overhead(Metachunk::overhead());
-    chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead());
-    if (chunk != current_chunk()) {
-      chunk_stat.add_waste(chunk->free_word_size());
-    } else {
-      chunk_stat.add_free(chunk->free_word_size());
-    }
-    chunk = chunk->next();
-  }
-  if (block_freelists() != NULL) {
-    out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size());
-  }
-}
-
-void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const {
-  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
-  add_to_statistics_locked(out);
-}
-
-#ifdef ASSERT
-void SpaceManager::verify_metrics_locked() const {
-  assert_lock_strong(lock());
-
-  SpaceManagerStatistics stat;
-  add_to_statistics_locked(&stat);
-
-  UsedChunksStatistics chunk_stats = stat.totals();
-
-  DEBUG_ONLY(chunk_stats.check_sanity());
-
-  assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words");
-  assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words");
-  assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words");
-}
-
-void SpaceManager::verify_metrics() const {
-  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
-  verify_metrics_locked();
-}
-#endif // ASSERT
-
-
-
 // MetaspaceUtils
 size_t MetaspaceUtils::_capacity_words [Metaspace:: MetadataTypeCount] = {0, 0};
 size_t MetaspaceUtils::_overhead_words [Metaspace:: MetadataTypeCount] = {0, 0};
@@ -3733,72 +482,6 @@
   }
 }
 
-class PrintCLDMetaspaceInfoClosure : public CLDClosure {
-private:
-  outputStream* const _out;
-  const size_t        _scale;
-  const bool          _do_print;
-  const bool          _break_down_by_chunktype;
-
-public:
-
-  uintx                           _num_loaders;
-  ClassLoaderMetaspaceStatistics  _stats_total;
-
-  uintx                           _num_loaders_by_spacetype [Metaspace::MetaspaceTypeCount];
-  ClassLoaderMetaspaceStatistics  _stats_by_spacetype [Metaspace::MetaspaceTypeCount];
-
-public:
-  PrintCLDMetaspaceInfoClosure(outputStream* out, size_t scale, bool do_print, bool break_down_by_chunktype)
-    : _out(out), _scale(scale), _do_print(do_print), _break_down_by_chunktype(break_down_by_chunktype)
-    , _num_loaders(0)
-  {
-    memset(_num_loaders_by_spacetype, 0, sizeof(_num_loaders_by_spacetype));
-  }
-
-  void do_cld(ClassLoaderData* cld) {
-
-    assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
-
-    ClassLoaderMetaspace* msp = cld->metaspace_or_null();
-    if (msp == NULL) {
-      return;
-    }
-
-    // Collect statistics for this class loader metaspace
-    ClassLoaderMetaspaceStatistics this_cld_stat;
-    msp->add_to_statistics(&this_cld_stat);
-
-    // And add it to the running totals
-    _stats_total.add(this_cld_stat);
-    _num_loaders ++;
-    _stats_by_spacetype[msp->space_type()].add(this_cld_stat);
-    _num_loaders_by_spacetype[msp->space_type()] ++;
-
-    // Optionally, print.
-    if (_do_print) {
-
-      _out->print(UINTX_FORMAT_W(4) ": ", _num_loaders);
-
-      if (cld->is_anonymous()) {
-        _out->print("ClassLoaderData " PTR_FORMAT " for anonymous class", p2i(cld));
-      } else {
-        ResourceMark rm;
-        _out->print("ClassLoaderData " PTR_FORMAT " for %s", p2i(cld), cld->loader_name());
-      }
-
-      if (cld->is_unloading()) {
-        _out->print(" (unloading)");
-      }
-
-      this_cld_stat.print_on(_out, _scale, _break_down_by_chunktype);
-      _out->cr();
-
-    }
-
-  } // do_cld
-
-};
 
 void MetaspaceUtils::print_vs(outputStream* out, size_t scale) {
   const size_t reserved_nonclass_words = reserved_bytes(Metaspace::NonClassType) / sizeof(MetaWord);
@@ -4839,24 +1522,6 @@
   add_to_statistics_locked(out);
 }
 
-#ifdef ASSERT
-static void do_verify_chunk(Metachunk* chunk) {
-  guarantee(chunk != NULL, "Sanity");
-  // Verify chunk itself; then verify that it is consistent with the
-  // occupany map of its containing node.
-  chunk->verify();
-  VirtualSpaceNode* const vsn = chunk->container();
-  OccupancyMap* const ocmap = vsn->occupancy_map();
-  ocmap->verify_for_chunk(chunk);
-}
-#endif
-
-static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) {
-  chunk->set_is_tagged_free(!inuse);
-  OccupancyMap* const ocmap = chunk->container()->occupancy_map();
-  ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse);
-}
-
 /////////////// Unit tests ///////////////
 
 #ifndef PRODUCT
@@ -5081,99 +1746,8 @@
   }
 };
 
-// The following test is placed here instead of a gtest / unittest file
-// because the ChunkManager class is only available in this file.
-void ChunkManager_test_list_index() {
-  {
-    // Test previous bug where a query for a humongous class metachunk,
-    // incorrectly matched the non-class medium metachunk size.
-    {
-      ChunkManager manager(true);
-
-      assert(MediumChunk > ClassMediumChunk, "Precondition for test");
-
-      ChunkIndex index = manager.list_index(MediumChunk);
-
-      assert(index == HumongousIndex,
-          "Requested size is larger than ClassMediumChunk,"
-          " so should return HumongousIndex. Got index: %d", (int)index);
-    }
-
-    // Check the specified sizes as well.
-    {
-      ChunkManager manager(true);
-      assert(manager.list_index(ClassSpecializedChunk) == SpecializedIndex, "sanity");
-      assert(manager.list_index(ClassSmallChunk) == SmallIndex, "sanity");
-      assert(manager.list_index(ClassMediumChunk) == MediumIndex, "sanity");
-      assert(manager.list_index(ClassMediumChunk + ClassSpecializedChunk) == HumongousIndex, "sanity");
-    }
-    {
-      ChunkManager manager(false);
-      assert(manager.list_index(SpecializedChunk) == SpecializedIndex, "sanity");
-      assert(manager.list_index(SmallChunk) == SmallIndex, "sanity");
-      assert(manager.list_index(MediumChunk) == MediumIndex, "sanity");
-      assert(manager.list_index(MediumChunk + SpecializedChunk) == HumongousIndex, "sanity");
-    }
-
-  }
-
-}
-
 #endif // !PRODUCT
 
-#ifdef ASSERT
-
-// The following test is placed here instead of a gtest / unittest file
-// because the ChunkManager class is only available in this file.
-class SpaceManagerTest : AllStatic {
-  friend void SpaceManager_test_adjust_initial_chunk_size();
-
-  static void test_adjust_initial_chunk_size(bool is_class) {
-    const size_t smallest = SpaceManager::smallest_chunk_size(is_class);
-    const size_t normal   = SpaceManager::small_chunk_size(is_class);
-    const size_t medium   = SpaceManager::medium_chunk_size(is_class);
-
-#define test_adjust_initial_chunk_size(value, expected, is_class_value)          \
-    do {                                                                         \
-      size_t v = value;                                                          \
-      size_t e = expected;                                                       \
-      assert(SpaceManager::adjust_initial_chunk_size(v, (is_class_value)) == e,  \
-             "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT, e, v);               \
-    } while (0)
-
-    // Smallest (specialized)
-    test_adjust_initial_chunk_size(1,            smallest, is_class);
-    test_adjust_initial_chunk_size(smallest - 1, smallest, is_class);
-    test_adjust_initial_chunk_size(smallest,     smallest, is_class);
-
-    // Small
-    test_adjust_initial_chunk_size(smallest + 1, normal, is_class);
-    test_adjust_initial_chunk_size(normal - 1,   normal, is_class);
-    test_adjust_initial_chunk_size(normal,       normal, is_class);
-
-    // Medium
-    test_adjust_initial_chunk_size(normal + 1, medium, is_class);
-    test_adjust_initial_chunk_size(medium - 1, medium, is_class);
-    test_adjust_initial_chunk_size(medium,     medium, is_class);
-
-    // Humongous
-    test_adjust_initial_chunk_size(medium + 1, medium + 1, is_class);
-
-#undef test_adjust_initial_chunk_size
-  }
-
-  static void test_adjust_initial_chunk_size() {
-    test_adjust_initial_chunk_size(false);
-    test_adjust_initial_chunk_size(true);
-  }
-};
-
-void SpaceManager_test_adjust_initial_chunk_size() {
-  SpaceManagerTest::test_adjust_initial_chunk_size();
-}
-
-#endif // ASSERT
-
 struct chunkmanager_statistics_t {
   int num_specialized_chunks;
   int num_small_chunks;
--- a/src/hotspot/share/memory/metaspace.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace.hpp	Mon May 21 11:33:59 2018 +0200
@@ -55,23 +55,23 @@
 //                       +-------------------+
 //
 
-class ChunkManager;
 class ClassLoaderData;
-class Metablock;
-class Metachunk;
 class MetaspaceTracer;
 class MetaWord;
 class Mutex;
 class outputStream;
-class PrintCLDMetaspaceInfoClosure;
-class SpaceManager;
-class VirtualSpaceList;
+
 class CollectedHeap;
 
 namespace metaspace {
-namespace internals {
+  class ChunkManager;
   class ClassLoaderMetaspaceStatistics;
-}}
+  class Metablock;
+  class Metachunk;
+  class PrintCLDMetaspaceInfoClosure;
+  class SpaceManager;
+  class VirtualSpaceList;
+}
 
 // Metaspaces each have a  SpaceManager and allocations
 // are done by the SpaceManager.  Allocations are done
@@ -131,31 +131,31 @@
   DEBUG_ONLY(static bool   _frozen;)
 
   // Virtual Space lists for both classes and other metadata
-  static VirtualSpaceList* _space_list;
-  static VirtualSpaceList* _class_space_list;
+  static metaspace::VirtualSpaceList* _space_list;
+  static metaspace::VirtualSpaceList* _class_space_list;
 
-  static ChunkManager* _chunk_manager_metadata;
-  static ChunkManager* _chunk_manager_class;
+  static metaspace::ChunkManager* _chunk_manager_metadata;
+  static metaspace::ChunkManager* _chunk_manager_class;
 
   static const MetaspaceTracer* _tracer;
 
  public:
-  static VirtualSpaceList* space_list()       { return _space_list; }
-  static VirtualSpaceList* class_space_list() { return _class_space_list; }
-  static VirtualSpaceList* get_space_list(MetadataType mdtype) {
+  static metaspace::VirtualSpaceList* space_list()       { return _space_list; }
+  static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; }
+  static metaspace::VirtualSpaceList* get_space_list(MetadataType mdtype) {
     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
     return mdtype == ClassType ? class_space_list() : space_list();
   }
 
-  static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
-  static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
-  static ChunkManager* get_chunk_manager(MetadataType mdtype) {
+  static metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
+  static metaspace::ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
+  static metaspace::ChunkManager* get_chunk_manager(MetadataType mdtype) {
     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
   }
 
   // convenience function
-  static ChunkManager* get_chunk_manager(bool is_class) {
+  static metaspace::ChunkManager* get_chunk_manager(bool is_class) {
     return is_class ? chunk_manager_class() : chunk_manager_metadata();
   }
 
@@ -231,7 +231,7 @@
   friend class CollectedHeap; // For expand_and_allocate()
   friend class Metaspace;
   friend class MetaspaceUtils;
-  friend class PrintCLDMetaspaceInfoClosure;
+  friend class metaspace::PrintCLDMetaspaceInfoClosure;
   friend class VM_CollectForMetadataAllocation; // For expand_and_allocate()
 
  private:
@@ -242,16 +242,16 @@
   // special cases such as the boot class loader, reflection
   // class loader and anonymous class loader.
   void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
-  Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
+  metaspace::Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
 
   const Metaspace::MetaspaceType _space_type;
   Mutex* const  _lock;
-  SpaceManager* _vsm;
-  SpaceManager* _class_vsm;
+  metaspace::SpaceManager* _vsm;
+  metaspace::SpaceManager* _class_vsm;
 
-  SpaceManager* vsm() const { return _vsm; }
-  SpaceManager* class_vsm() const { return _class_vsm; }
-  SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) {
+  metaspace::SpaceManager* vsm() const { return _vsm; }
+  metaspace::SpaceManager* class_vsm() const { return _class_vsm; }
+  metaspace::SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) {
     assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
     return mdtype == Metaspace::ClassType ? class_vsm() : vsm();
   }
@@ -263,15 +263,15 @@
   size_t class_chunk_size(size_t word_size);
 
   // Adds to the given statistic object. Must be locked with CLD metaspace lock.
-  void add_to_statistics_locked(metaspace::internals::ClassLoaderMetaspaceStatistics* out) const;
+  void add_to_statistics_locked(metaspace::ClassLoaderMetaspaceStatistics* out) const;
+
+  Metaspace::MetaspaceType space_type() const { return _space_type; }
 
  public:
 
   ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type);
   ~ClassLoaderMetaspace();
 
-  Metaspace::MetaspaceType space_type() const { return _space_type; }
-
   // Allocate space for metadata of type mdtype. This is space
   // within a Metachunk and is used by
   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
@@ -287,14 +287,14 @@
   void verify();
 
   // Adds to the given statistic object. Will lock with CLD metaspace lock.
-  void add_to_statistics(metaspace::internals::ClassLoaderMetaspaceStatistics* out) const;
+  void add_to_statistics(metaspace::ClassLoaderMetaspaceStatistics* out) const;
 
 }; // ClassLoaderMetaspace
 
 class MetaspaceUtils : AllStatic {
 
   // Spacemanager updates running counters.
-  friend class SpaceManager;
+  friend class metaspace::SpaceManager;
 
   // Running counters for statistics concerning in-use chunks.
   // Note: capacity = used + free + waste + overhead. Note that we do not
@@ -328,7 +328,7 @@
   // Collect used metaspace statistics. This involves walking the CLDG. The resulting
   // output will be the accumulated values for all live metaspaces.
   // Note: method does not do any locking.
-  static void collect_statistics(metaspace::internals::ClassLoaderMetaspaceStatistics* out);
+  static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out);
 
   // Used by MetaspaceCounters
   static size_t free_chunks_total_words();
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/blockFreelist.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#include "precompiled.hpp"
+
+#include "logging/log.hpp"
+#include "memory/binaryTreeDictionary.inline.hpp"
+#include "memory/metaspace/blockFreelist.hpp"
+#include "utilities/ostream.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+
+namespace metaspace {
+
+
+BlockFreelist::BlockFreelist() : _dictionary(new BlockTreeDictionary()), _small_blocks(NULL) {}
+
+BlockFreelist::~BlockFreelist() {
+  delete _dictionary;
+  if (_small_blocks != NULL) {
+    delete _small_blocks;
+  }
+}
+
+void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
+  assert(word_size >= SmallBlocks::small_block_min_size(), "never return dark matter");
+
+  Metablock* free_chunk = ::new (p) Metablock(word_size);
+  if (word_size < SmallBlocks::small_block_max_size()) {
+    small_blocks()->return_block(free_chunk, word_size);
+  } else {
+  dictionary()->return_chunk(free_chunk);
+}
+  log_trace(gc, metaspace, freelist, blocks)("returning block at " INTPTR_FORMAT " size = "
+            SIZE_FORMAT, p2i(free_chunk), word_size);
+}
+
+MetaWord* BlockFreelist::get_block(size_t word_size) {
+  assert(word_size >= SmallBlocks::small_block_min_size(), "never get dark matter");
+
+  // Try small_blocks first.
+  if (word_size < SmallBlocks::small_block_max_size()) {
+    // Don't create small_blocks() until needed.  small_blocks() allocates the small block list for
+    // this space manager.
+    MetaWord* new_block = (MetaWord*) small_blocks()->get_block(word_size);
+    if (new_block != NULL) {
+      log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
+              p2i(new_block), word_size);
+      return new_block;
+    }
+  }
+
+  if (word_size < BlockFreelist::min_dictionary_size()) {
+    // If allocation in small blocks fails, this is Dark Matter.  Too small for dictionary.
+    return NULL;
+  }
+
+  Metablock* free_block = dictionary()->get_chunk(word_size);
+  if (free_block == NULL) {
+    return NULL;
+  }
+
+  const size_t block_size = free_block->size();
+  if (block_size > WasteMultiplier * word_size) {
+    return_block((MetaWord*)free_block, block_size);
+    return NULL;
+  }
+
+  MetaWord* new_block = (MetaWord*)free_block;
+  assert(block_size >= word_size, "Incorrect size of block from freelist");
+  const size_t unused = block_size - word_size;
+  if (unused >= SmallBlocks::small_block_min_size()) {
+    return_block(new_block + word_size, unused);
+  }
+
+  log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
+            p2i(new_block), word_size);
+  return new_block;
+}
+
+void BlockFreelist::print_on(outputStream* st) const {
+  dictionary()->print_free_lists(st);
+  if (_small_blocks != NULL) {
+    _small_blocks->print_on(st);
+  }
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/blockFreelist.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_BLOCKFREELIST_HPP
+#define SHARE_MEMORY_METASPACE_BLOCKFREELIST_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/binaryTreeDictionary.hpp"
+#include "memory/freeList.hpp"
+#include "memory/metaspace/smallBlocks.hpp"
+#include "memory/metaspace/metablock.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary;
+
+// Used to manage the free list of Metablocks (a block corresponds
+// to the allocation of a quantum of metadata).
+class BlockFreelist : public CHeapObj<mtClass> {
+
+  BlockTreeDictionary* const _dictionary;
+  SmallBlocks* _small_blocks;
+
+  // Only allocate and split from freelist if the size of the allocation
+  // is at least 1/4th the size of the available block.
+  const static int WasteMultiplier = 4;
+
+  // Accessors
+  BlockTreeDictionary* dictionary() const { return _dictionary; }
+  SmallBlocks* small_blocks() {
+    if (_small_blocks == NULL) {
+      _small_blocks = new SmallBlocks();
+    }
+    return _small_blocks;
+  }
+
+ public:
+
+  BlockFreelist();
+  ~BlockFreelist();
+
+  // Get and return a block to the free list
+  MetaWord* get_block(size_t word_size);
+  void return_block(MetaWord* p, size_t word_size);
+
+  // Returns the total size, in words, of all blocks kept in this structure.
+  size_t total_size() const  {
+    size_t result = dictionary()->total_size();
+    if (_small_blocks != NULL) {
+      result = result + _small_blocks->total_size();
+    }
+    return result;
+  }
+
+  // Returns the number of all blocks kept in this structure.
+  uintx num_blocks() const {
+    uintx result = dictionary()->total_free_blocks();
+    if (_small_blocks != NULL) {
+      result = result + _small_blocks->total_num_blocks();
+    }
+    return result;
+  }
+
+  static size_t min_dictionary_size()   { return TreeChunk<Metablock, FreeList<Metablock> >::min_size(); }
+  void print_on(outputStream* st) const;
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_BLOCKFREELIST_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/chunkManager.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,654 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#include "precompiled.hpp"
+
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/binaryTreeDictionary.inline.hpp"
+#include "memory/freeList.inline.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "memory/metaspace/occupancyMap.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/ostream.hpp"
+
+namespace metaspace {
+
+void ChunkManager::remove_chunk(Metachunk* chunk) {
+  size_t word_size = chunk->word_size();
+  ChunkIndex index = list_index(word_size);
+  if (index != HumongousIndex) {
+    free_chunks(index)->remove_chunk(chunk);
+  } else {
+    humongous_dictionary()->remove_chunk(chunk);
+  }
+
+  // Chunk has been removed from the chunks free list, update counters.
+  account_for_removed_chunk(chunk);
+}
+
+bool ChunkManager::attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  assert(chunk != NULL, "invalid chunk pointer");
+  // Check for valid merge combinations.
+  assert((chunk->get_chunk_type() == SpecializedIndex &&
+          (target_chunk_type == SmallIndex || target_chunk_type == MediumIndex)) ||
+         (chunk->get_chunk_type() == SmallIndex && target_chunk_type == MediumIndex),
+        "Invalid chunk merge combination.");
+
+  const size_t target_chunk_word_size =
+    get_size_for_nonhumongous_chunktype(target_chunk_type, this->is_class());
+
+  // [ prospective merge region )
+  MetaWord* const p_merge_region_start =
+    (MetaWord*) align_down(chunk, target_chunk_word_size * sizeof(MetaWord));
+  MetaWord* const p_merge_region_end =
+    p_merge_region_start + target_chunk_word_size;
+
+  // We need the VirtualSpaceNode containing this chunk and its occupancy map.
+  VirtualSpaceNode* const vsn = chunk->container();
+  OccupancyMap* const ocmap = vsn->occupancy_map();
+
+  // The prospective chunk merge range must be completely contained by the
+  // committed range of the virtual space node.
+  if (p_merge_region_start < vsn->bottom() || p_merge_region_end > vsn->top()) {
+    return false;
+  }
+
+  // Only attempt to merge this range if at its start a chunk starts and at its end
+  // a chunk ends. If a chunk (can only be humongous) straddles either start or end
+  // of that range, we cannot merge.
+  if (!ocmap->chunk_starts_at_address(p_merge_region_start)) {
+    return false;
+  }
+  if (p_merge_region_end < vsn->top() &&
+      !ocmap->chunk_starts_at_address(p_merge_region_end)) {
+    return false;
+  }
+
+  // Now check if the prospective merge area contains live chunks. If it does we cannot merge.
+  if (ocmap->is_region_in_use(p_merge_region_start, target_chunk_word_size)) {
+    return false;
+  }
+
+  // Success! Remove all chunks in this region...
+  log_trace(gc, metaspace, freelist)("%s: coalescing chunks in area [%p-%p)...",
+    (is_class() ? "class space" : "metaspace"),
+    p_merge_region_start, p_merge_region_end);
+
+  const int num_chunks_removed =
+    remove_chunks_in_area(p_merge_region_start, target_chunk_word_size);
+
+  // ... and create a single new bigger chunk.
+  Metachunk* const p_new_chunk =
+      ::new (p_merge_region_start) Metachunk(target_chunk_type, is_class(), target_chunk_word_size, vsn);
+  assert(p_new_chunk == (Metachunk*)p_merge_region_start, "Sanity");
+  p_new_chunk->set_origin(origin_merge);
+
+  log_trace(gc, metaspace, freelist)("%s: created coalesced chunk at %p, size " SIZE_FORMAT_HEX ".",
+    (is_class() ? "class space" : "metaspace"),
+    p_new_chunk, p_new_chunk->word_size() * sizeof(MetaWord));
+
+  // Fix occupancy map: remove old start bits of the small chunks and set new start bit.
+  ocmap->wipe_chunk_start_bits_in_region(p_merge_region_start, target_chunk_word_size);
+  ocmap->set_chunk_starts_at_address(p_merge_region_start, true);
+
+  // Mark chunk as free. Note: it is not necessary to update the occupancy
+  // map in-use map, because the old chunks were also free, so nothing
+  // should have changed.
+  p_new_chunk->set_is_tagged_free(true);
+
+  // Add new chunk to its freelist.
+  ChunkList* const list = free_chunks(target_chunk_type);
+  list->return_chunk_at_head(p_new_chunk);
+
+  // And adjust ChunkManager:: _free_chunks_count (_free_chunks_total
+  // should not have changed, because the size of the space should be the same)
+  _free_chunks_count -= num_chunks_removed;
+  _free_chunks_count ++;
+
+  // VirtualSpaceNode::container_count does not have to be modified:
+  // it means "number of active (non-free) chunks", so merging free chunks
+  // should not affect that count.
+
+  // At the end of a chunk merge, run verification tests.
+  if (VerifyMetaspace) {
+    DEBUG_ONLY(this->locked_verify());
+    DEBUG_ONLY(vsn->verify());
+  }
+
+  return true;
+}
+
+// Remove all chunks in the given area - the chunks are supposed to be free -
+// from their corresponding freelists. Mark them as invalid.
+// - This does not correct the occupancy map.
+// - This does not adjust the counters in ChunkManager.
+// - Does not adjust container count counter in containing VirtualSpaceNode
+// Returns number of chunks removed.
+int ChunkManager::remove_chunks_in_area(MetaWord* p, size_t word_size) {
+  assert(p != NULL && word_size > 0, "Invalid range.");
+  const size_t smallest_chunk_size = get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class());
+  assert_is_aligned(word_size, smallest_chunk_size);
+
+  Metachunk* const start = (Metachunk*) p;
+  const Metachunk* const end = (Metachunk*)(p + word_size);
+  Metachunk* cur = start;
+  int num_removed = 0;
+  while (cur < end) {
+    Metachunk* next = (Metachunk*)(((MetaWord*)cur) + cur->word_size());
+    DEBUG_ONLY(do_verify_chunk(cur));
+    assert(cur->get_chunk_type() != HumongousIndex, "Unexpected humongous chunk found at %p.", cur);
+    assert(cur->is_tagged_free(), "Chunk expected to be free (%p)", cur);
+    log_trace(gc, metaspace, freelist)("%s: removing chunk %p, size " SIZE_FORMAT_HEX ".",
+      (is_class() ? "class space" : "metaspace"),
+      cur, cur->word_size() * sizeof(MetaWord));
+    cur->remove_sentinel();
+    // Note: cannot call ChunkManager::remove_chunk, because that
+    // modifies the counters in ChunkManager, which we do not want. So
+    // we call remove_chunk on the freelist directly (see also the
+    // splitting function which does the same).
+    ChunkList* const list = free_chunks(list_index(cur->word_size()));
+    list->remove_chunk(cur);
+    num_removed ++;
+    cur = next;
+  }
+  return num_removed;
+}
+
+size_t ChunkManager::free_chunks_total_words() {
+  return _free_chunks_total;
+}
+
+size_t ChunkManager::free_chunks_total_bytes() {
+  return free_chunks_total_words() * BytesPerWord;
+}
+
+// Update internal accounting after a chunk was added
+void ChunkManager::account_for_added_chunk(const Metachunk* c) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _free_chunks_count ++;
+  _free_chunks_total += c->word_size();
+}
+
+// Update internal accounting after a chunk was removed
+void ChunkManager::account_for_removed_chunk(const Metachunk* c) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  assert(_free_chunks_count >= 1,
+    "ChunkManager::_free_chunks_count: about to go negative (" SIZE_FORMAT ").", _free_chunks_count);
+  assert(_free_chunks_total >= c->word_size(),
+    "ChunkManager::_free_chunks_total: about to go negative"
+     "(now: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ").", _free_chunks_total, c->word_size());
+  _free_chunks_count --;
+  _free_chunks_total -= c->word_size();
+}
+
+size_t ChunkManager::free_chunks_count() {
+#ifdef ASSERT
+  if (!UseConcMarkSweepGC && !MetaspaceExpand_lock->is_locked()) {
+    MutexLockerEx cl(MetaspaceExpand_lock,
+                     Mutex::_no_safepoint_check_flag);
+    // This lock is only needed in debug because the verification
+    // of the _free_chunks_totals walks the list of free chunks
+    slow_locked_verify_free_chunks_count();
+  }
+#endif
+  return _free_chunks_count;
+}
+
+ChunkIndex ChunkManager::list_index(size_t size) {
+  return get_chunk_type_by_size(size, is_class());
+}
+
+size_t ChunkManager::size_by_index(ChunkIndex index) const {
+  index_bounds_check(index);
+  assert(index != HumongousIndex, "Do not call for humongous chunks.");
+  return get_size_for_nonhumongous_chunktype(index, is_class());
+}
+
+void ChunkManager::locked_verify_free_chunks_total() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  assert(sum_free_chunks() == _free_chunks_total,
+         "_free_chunks_total " SIZE_FORMAT " is not the"
+         " same as sum " SIZE_FORMAT, _free_chunks_total,
+         sum_free_chunks());
+}
+
+void ChunkManager::locked_verify_free_chunks_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  assert(sum_free_chunks_count() == _free_chunks_count,
+         "_free_chunks_count " SIZE_FORMAT " is not the"
+         " same as sum " SIZE_FORMAT, _free_chunks_count,
+         sum_free_chunks_count());
+}
+
+void ChunkManager::verify() {
+  MutexLockerEx cl(MetaspaceExpand_lock,
+                     Mutex::_no_safepoint_check_flag);
+  locked_verify();
+}
+
+void ChunkManager::locked_verify() {
+  locked_verify_free_chunks_count();
+  locked_verify_free_chunks_total();
+  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+    ChunkList* list = free_chunks(i);
+    if (list != NULL) {
+      Metachunk* chunk = list->head();
+      while (chunk) {
+        DEBUG_ONLY(do_verify_chunk(chunk);)
+        assert(chunk->is_tagged_free(), "Chunk should be tagged as free.");
+        chunk = chunk->next();
+      }
+    }
+  }
+}
+
+void ChunkManager::locked_print_free_chunks(outputStream* st) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  st->print_cr("Free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
+                _free_chunks_total, _free_chunks_count);
+}
+
+void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  st->print_cr("Sum free chunk total " SIZE_FORMAT "  count " SIZE_FORMAT,
+                sum_free_chunks(), sum_free_chunks_count());
+}
+
+ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
+  assert(index == SpecializedIndex || index == SmallIndex || index == MediumIndex,
+         "Bad index: %d", (int)index);
+
+  return &_free_chunks[index];
+}
+
+// These methods that sum the free chunk lists are used in printing
+// methods that are used in product builds.
+size_t ChunkManager::sum_free_chunks() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  size_t result = 0;
+  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+    ChunkList* list = free_chunks(i);
+
+    if (list == NULL) {
+      continue;
+    }
+
+    result = result + list->count() * list->size();
+  }
+  result = result + humongous_dictionary()->total_size();
+  return result;
+}
+
+size_t ChunkManager::sum_free_chunks_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  size_t count = 0;
+  for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+    ChunkList* list = free_chunks(i);
+    if (list == NULL) {
+      continue;
+    }
+    count = count + list->count();
+  }
+  count = count + humongous_dictionary()->total_free_blocks();
+  return count;
+}
+
+ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
+  ChunkIndex index = list_index(word_size);
+  assert(index < HumongousIndex, "No humongous list");
+  return free_chunks(index);
+}
+
+// Helper for chunk splitting: given a target chunk size and a larger free chunk,
+// split up the larger chunk into n smaller chunks, at least one of which should be
+// the target chunk of target chunk size. The smaller chunks, including the target
+// chunk, are returned to the freelist. The pointer to the target chunk is returned.
+// Note that this chunk is supposed to be removed from the freelist right away.
+Metachunk* ChunkManager::split_chunk(size_t target_chunk_word_size, Metachunk* larger_chunk) {
+  assert(larger_chunk->word_size() > target_chunk_word_size, "Sanity");
+
+  const ChunkIndex larger_chunk_index = larger_chunk->get_chunk_type();
+  const ChunkIndex target_chunk_index = get_chunk_type_by_size(target_chunk_word_size, is_class());
+
+  MetaWord* const region_start = (MetaWord*)larger_chunk;
+  const size_t region_word_len = larger_chunk->word_size();
+  MetaWord* const region_end = region_start + region_word_len;
+  VirtualSpaceNode* const vsn = larger_chunk->container();
+  OccupancyMap* const ocmap = vsn->occupancy_map();
+
+  // Any larger non-humongous chunk size is a multiple of any smaller chunk size.
+  // Since non-humongous chunks are aligned to their chunk size, the larger chunk should start
+  // at an address suitable to place the smaller target chunk.
+  assert_is_aligned(region_start, target_chunk_word_size);
+
+  // Remove old chunk.
+  free_chunks(larger_chunk_index)->remove_chunk(larger_chunk);
+  larger_chunk->remove_sentinel();
+
+  // Prevent access to the old chunk from here on.
+  larger_chunk = NULL;
+  // ... and wipe it.
+  DEBUG_ONLY(memset(region_start, 0xfe, region_word_len * BytesPerWord));
+
+  // In its place create first the target chunk...
+  MetaWord* p = region_start;
+  Metachunk* target_chunk = ::new (p) Metachunk(target_chunk_index, is_class(), target_chunk_word_size, vsn);
+  assert(target_chunk == (Metachunk*)p, "Sanity");
+  target_chunk->set_origin(origin_split);
+
+  // Note: we do not need to mark its start in the occupancy map
+  // because it coincides with the old chunk start.
+
+  // Mark chunk as free and return to the freelist.
+  do_update_in_use_info_for_chunk(target_chunk, false);
+  free_chunks(target_chunk_index)->return_chunk_at_head(target_chunk);
+
+  // This chunk should now be valid and can be verified.
+  DEBUG_ONLY(do_verify_chunk(target_chunk));
+
+  // In the remaining space create the remainder chunks.
+  p += target_chunk->word_size();
+  assert(p < region_end, "Sanity");
+
+  while (p < region_end) {
+
+    // Find the largest chunk size which fits the alignment requirements at address p.
+    ChunkIndex this_chunk_index = prev_chunk_index(larger_chunk_index);
+    size_t this_chunk_word_size = 0;
+    for(;;) {
+      this_chunk_word_size = get_size_for_nonhumongous_chunktype(this_chunk_index, is_class());
+      if (is_aligned(p, this_chunk_word_size * BytesPerWord)) {
+        break;
+      } else {
+        this_chunk_index = prev_chunk_index(this_chunk_index);
+        assert(this_chunk_index >= target_chunk_index, "Sanity");
+      }
+    }
+
+    assert(this_chunk_word_size >= target_chunk_word_size, "Sanity");
+    assert(is_aligned(p, this_chunk_word_size * BytesPerWord), "Sanity");
+    assert(p + this_chunk_word_size <= region_end, "Sanity");
+
+    // Create splitting chunk.
+    Metachunk* this_chunk = ::new (p) Metachunk(this_chunk_index, is_class(), this_chunk_word_size, vsn);
+    assert(this_chunk == (Metachunk*)p, "Sanity");
+    this_chunk->set_origin(origin_split);
+    ocmap->set_chunk_starts_at_address(p, true);
+    do_update_in_use_info_for_chunk(this_chunk, false);
+
+    // This chunk should be valid and can be verified.
+    DEBUG_ONLY(do_verify_chunk(this_chunk));
+
+    // Return this chunk to freelist and correct counter.
+    free_chunks(this_chunk_index)->return_chunk_at_head(this_chunk);
+    _free_chunks_count ++;
+
+    log_trace(gc, metaspace, freelist)("Created chunk at " PTR_FORMAT ", word size "
+      SIZE_FORMAT_HEX " (%s), in split region [" PTR_FORMAT "..." PTR_FORMAT ").",
+      p2i(this_chunk), this_chunk->word_size(), chunk_size_name(this_chunk_index),
+      p2i(region_start), p2i(region_end));
+
+    p += this_chunk_word_size;
+
+  }
+
+  return target_chunk;
+}
+
+Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
+  assert_lock_strong(MetaspaceExpand_lock);
+
+  slow_locked_verify();
+
+  Metachunk* chunk = NULL;
+  bool we_did_split_a_chunk = false;
+
+  if (list_index(word_size) != HumongousIndex) {
+
+    ChunkList* free_list = find_free_chunks_list(word_size);
+    assert(free_list != NULL, "Sanity check");
+
+    chunk = free_list->head();
+
+    if (chunk == NULL) {
+      // Split large chunks into smaller chunks if there are no smaller chunks, just large chunks.
+      // This is the counterpart of the coalescing-upon-chunk-return.
+
+      ChunkIndex target_chunk_index = get_chunk_type_by_size(word_size, is_class());
+
+      // Is there a larger chunk we could split?
+      Metachunk* larger_chunk = NULL;
+      ChunkIndex larger_chunk_index = next_chunk_index(target_chunk_index);
+      while (larger_chunk == NULL && larger_chunk_index < NumberOfFreeLists) {
+        larger_chunk = free_chunks(larger_chunk_index)->head();
+        if (larger_chunk == NULL) {
+          larger_chunk_index = next_chunk_index(larger_chunk_index);
+        }
+      }
+
+      if (larger_chunk != NULL) {
+        assert(larger_chunk->word_size() > word_size, "Sanity");
+        assert(larger_chunk->get_chunk_type() == larger_chunk_index, "Sanity");
+
+        // We found a larger chunk. Lets split it up:
+        // - remove old chunk
+        // - in its place, create new smaller chunks, with at least one chunk
+        //   being of target size, the others sized as large as possible. This
+        //   is to make sure the resulting chunks are "as coalesced as possible"
+        //   (similar to VirtualSpaceNode::retire()).
+        // Note: during this operation both ChunkManager and VirtualSpaceNode
+        //  are temporarily invalid, so be careful with asserts.
+
+        log_trace(gc, metaspace, freelist)("%s: splitting chunk " PTR_FORMAT
+           ", word size " SIZE_FORMAT_HEX " (%s), to get a chunk of word size " SIZE_FORMAT_HEX " (%s)...",
+          (is_class() ? "class space" : "metaspace"), p2i(larger_chunk), larger_chunk->word_size(),
+          chunk_size_name(larger_chunk_index), word_size, chunk_size_name(target_chunk_index));
+
+        chunk = split_chunk(word_size, larger_chunk);
+
+        // This should have worked.
+        assert(chunk != NULL, "Sanity");
+        assert(chunk->word_size() == word_size, "Sanity");
+        assert(chunk->is_tagged_free(), "Sanity");
+
+        we_did_split_a_chunk = true;
+
+      }
+    }
+
+    if (chunk == NULL) {
+      return NULL;
+    }
+
+    // Remove the chunk as the head of the list.
+    free_list->remove_chunk(chunk);
+
+    log_trace(gc, metaspace, freelist)("ChunkManager::free_chunks_get: free_list: " PTR_FORMAT " chunks left: " SSIZE_FORMAT ".",
+                                       p2i(free_list), free_list->count());
+
+  } else {
+    chunk = humongous_dictionary()->get_chunk(word_size);
+
+    if (chunk == NULL) {
+      return NULL;
+    }
+
+    log_debug(gc, metaspace, alloc)("Free list allocate humongous chunk size " SIZE_FORMAT " for requested size " SIZE_FORMAT " waste " SIZE_FORMAT,
+                                    chunk->word_size(), word_size, chunk->word_size() - word_size);
+  }
+
+  // Chunk has been removed from the chunk manager; update counters.
+  account_for_removed_chunk(chunk);
+  do_update_in_use_info_for_chunk(chunk, true);
+  chunk->container()->inc_container_count();
+  chunk->inc_use_count();
+
+  // Remove it from the links to this freelist
+  chunk->set_next(NULL);
+  chunk->set_prev(NULL);
+
+  // Run some verifications (some more if we did a chunk split)
+#ifdef ASSERT
+  if (VerifyMetaspace) {
+    locked_verify();
+    VirtualSpaceNode* const vsn = chunk->container();
+    vsn->verify();
+    if (we_did_split_a_chunk) {
+      vsn->verify_free_chunks_are_ideally_merged();
+    }
+  }
+#endif
+
+  return chunk;
+}
+
+Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  slow_locked_verify();
+
+  // Take from the beginning of the list
+  Metachunk* chunk = free_chunks_get(word_size);
+  if (chunk == NULL) {
+    return NULL;
+  }
+
+  assert((word_size <= chunk->word_size()) ||
+         (list_index(chunk->word_size()) == HumongousIndex),
+         "Non-humongous variable sized chunk");
+  LogTarget(Debug, gc, metaspace, freelist) lt;
+  if (lt.is_enabled()) {
+    size_t list_count;
+    if (list_index(word_size) < HumongousIndex) {
+      ChunkList* list = find_free_chunks_list(word_size);
+      list_count = list->count();
+    } else {
+      list_count = humongous_dictionary()->total_count();
+    }
+    LogStream ls(lt);
+    ls.print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk " PTR_FORMAT "  size " SIZE_FORMAT " count " SIZE_FORMAT " ",
+             p2i(this), p2i(chunk), chunk->word_size(), list_count);
+    ResourceMark rm;
+    locked_print_free_chunks(&ls);
+  }
+
+  return chunk;
+}
+
+void ChunkManager::return_single_chunk(Metachunk* chunk) {
+  const ChunkIndex index = chunk->get_chunk_type();
+  assert_lock_strong(MetaspaceExpand_lock);
+  DEBUG_ONLY(do_verify_chunk(chunk);)
+  assert(chunk != NULL, "Expected chunk.");
+  assert(chunk->container() != NULL, "Container should have been set.");
+  assert(chunk->is_tagged_free() == false, "Chunk should be in use.");
+  index_bounds_check(index);
+
+  // Note: mangle *before* returning the chunk to the freelist or dictionary. It does not
+  // matter for the freelist (non-humongous chunks), but the humongous chunk dictionary
+  // keeps tree node pointers in the chunk payload area which mangle will overwrite.
+  DEBUG_ONLY(chunk->mangle(badMetaWordVal);)
+
+  if (index != HumongousIndex) {
+    // Return non-humongous chunk to freelist.
+    ChunkList* list = free_chunks(index);
+    assert(list->size() == chunk->word_size(), "Wrong chunk type.");
+    list->return_chunk_at_head(chunk);
+    log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " to freelist.",
+        chunk_size_name(index), p2i(chunk));
+  } else {
+    // Return humongous chunk to dictionary.
+    assert(chunk->word_size() > free_chunks(MediumIndex)->size(), "Wrong chunk type.");
+    assert(chunk->word_size() % free_chunks(SpecializedIndex)->size() == 0,
+           "Humongous chunk has wrong alignment.");
+    _humongous_dictionary.return_chunk(chunk);
+    log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " (word size " SIZE_FORMAT ") to freelist.",
+        chunk_size_name(index), p2i(chunk), chunk->word_size());
+  }
+  chunk->container()->dec_container_count();
+  do_update_in_use_info_for_chunk(chunk, false);
+
+  // Chunk has been added; update counters.
+  account_for_added_chunk(chunk);
+
+  // Attempt coalesce returned chunks with its neighboring chunks:
+  // if this chunk is small or special, attempt to coalesce to a medium chunk.
+  if (index == SmallIndex || index == SpecializedIndex) {
+    if (!attempt_to_coalesce_around_chunk(chunk, MediumIndex)) {
+      // This did not work. But if this chunk is special, we still may form a small chunk?
+      if (index == SpecializedIndex) {
+        if (!attempt_to_coalesce_around_chunk(chunk, SmallIndex)) {
+          // give up.
+        }
+      }
+    }
+  }
+
+}
+
+void ChunkManager::return_chunk_list(Metachunk* chunks) {
+  if (chunks == NULL) {
+    return;
+  }
+  LogTarget(Trace, gc, metaspace, freelist) log;
+  if (log.is_enabled()) { // tracing
+    log.print("returning list of chunks...");
+  }
+  unsigned num_chunks_returned = 0;
+  size_t size_chunks_returned = 0;
+  Metachunk* cur = chunks;
+  while (cur != NULL) {
+    // Capture the next link before it is changed
+    // by the call to return_chunk_at_head();
+    Metachunk* next = cur->next();
+    if (log.is_enabled()) { // tracing
+      num_chunks_returned ++;
+      size_chunks_returned += cur->word_size();
+    }
+    return_single_chunk(cur);
+    cur = next;
+  }
+  if (log.is_enabled()) { // tracing
+    log.print("returned %u chunks to freelist, total word size " SIZE_FORMAT ".",
+        num_chunks_returned, size_chunks_returned);
+  }
+}
+
+void ChunkManager::collect_statistics(ChunkManagerStatistics* out) const {
+  MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
+  for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
+    out->chunk_stats(i).add(num_free_chunks(i), size_free_chunks_in_bytes(i) / sizeof(MetaWord));
+  }
+}
+
+} // namespace metaspace
+
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/chunkManager.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,229 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
+#define SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/binaryTreeDictionary.hpp"
+#include "memory/freeList.inline.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "memory/metaspaceChunkFreeListSummary.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class TestVirtualSpaceNodeTest;
+
+namespace metaspace {
+
+typedef class FreeList<Metachunk> ChunkList;
+typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary;
+
+// Manages the global free lists of chunks.
+class ChunkManager : public CHeapObj<mtInternal> {
+  friend class ::TestVirtualSpaceNodeTest;
+
+  // Free list of chunks of different sizes.
+  //   SpecializedChunk
+  //   SmallChunk
+  //   MediumChunk
+  ChunkList _free_chunks[NumberOfFreeLists];
+
+  // Whether or not this is the class chunkmanager.
+  const bool _is_class;
+
+  // Return non-humongous chunk list by its index.
+  ChunkList* free_chunks(ChunkIndex index);
+
+  // Returns non-humongous chunk list for the given chunk word size.
+  ChunkList* find_free_chunks_list(size_t word_size);
+
+  //   HumongousChunk
+  ChunkTreeDictionary _humongous_dictionary;
+
+  // Returns the humongous chunk dictionary.
+  ChunkTreeDictionary* humongous_dictionary() {
+    return &_humongous_dictionary;
+  }
+
+  // Size, in metaspace words, of all chunks managed by this ChunkManager
+  size_t _free_chunks_total;
+  // Number of chunks in this ChunkManager
+  size_t _free_chunks_count;
+
+  // Update counters after a chunk was added or removed removed.
+  void account_for_added_chunk(const Metachunk* c);
+  void account_for_removed_chunk(const Metachunk* c);
+
+  size_t sum_free_chunks();
+  size_t sum_free_chunks_count();
+
+  void locked_verify_free_chunks_total();
+  void slow_locked_verify_free_chunks_total() {
+    if (VerifyMetaspace) {
+      locked_verify_free_chunks_total();
+    }
+  }
+  void locked_verify_free_chunks_count();
+  void slow_locked_verify_free_chunks_count() {
+    if (VerifyMetaspace) {
+      locked_verify_free_chunks_count();
+    }
+  }
+
+  // Given a pointer to a chunk, attempts to merge it with neighboring
+  // free chunks to form a bigger chunk. Returns true if successful.
+  bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type);
+
+  // Helper for chunk merging:
+  //  Given an address range with 1-n chunks which are all supposed to be
+  //  free and hence currently managed by this ChunkManager, remove them
+  //  from this ChunkManager and mark them as invalid.
+  // - This does not correct the occupancy map.
+  // - This does not adjust the counters in ChunkManager.
+  // - Does not adjust container count counter in containing VirtualSpaceNode.
+  // Returns number of chunks removed.
+  int remove_chunks_in_area(MetaWord* p, size_t word_size);
+
+  // Helper for chunk splitting: given a target chunk size and a larger free chunk,
+  // split up the larger chunk into n smaller chunks, at least one of which should be
+  // the target chunk of target chunk size. The smaller chunks, including the target
+  // chunk, are returned to the freelist. The pointer to the target chunk is returned.
+  // Note that this chunk is supposed to be removed from the freelist right away.
+  Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk);
+
+ public:
+
+  ChunkManager(bool is_class)
+      : _is_class(is_class), _free_chunks_total(0), _free_chunks_count(0) {
+    _free_chunks[SpecializedIndex].set_size(get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class));
+    _free_chunks[SmallIndex].set_size(get_size_for_nonhumongous_chunktype(SmallIndex, is_class));
+    _free_chunks[MediumIndex].set_size(get_size_for_nonhumongous_chunktype(MediumIndex, is_class));
+  }
+
+  // Add or delete (return) a chunk to the global freelist.
+  Metachunk* chunk_freelist_allocate(size_t word_size);
+
+  // Map a size to a list index assuming that there are lists
+  // for special, small, medium, and humongous chunks.
+  ChunkIndex list_index(size_t size);
+
+  // Map a given index to the chunk size.
+  size_t size_by_index(ChunkIndex index) const;
+
+  bool is_class() const { return _is_class; }
+
+  // Convenience accessors.
+  size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); }
+  size_t small_chunk_word_size() const { return size_by_index(SmallIndex); }
+  size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); }
+
+  // Take a chunk from the ChunkManager. The chunk is expected to be in
+  // the chunk manager (the freelist if non-humongous, the dictionary if
+  // humongous).
+  void remove_chunk(Metachunk* chunk);
+
+  // Return a single chunk of type index to the ChunkManager.
+  void return_single_chunk(Metachunk* chunk);
+
+  // Add the simple linked list of chunks to the freelist of chunks
+  // of type index.
+  void return_chunk_list(Metachunk* chunk);
+
+  // Total of the space in the free chunks list
+  size_t free_chunks_total_words();
+  size_t free_chunks_total_bytes();
+
+  // Number of chunks in the free chunks list
+  size_t free_chunks_count();
+
+  // Remove from a list by size.  Selects list based on size of chunk.
+  Metachunk* free_chunks_get(size_t chunk_word_size);
+
+#define index_bounds_check(index)                                         \
+  assert(is_valid_chunktype(index), "Bad index: %d", (int) index)
+
+  size_t num_free_chunks(ChunkIndex index) const {
+    index_bounds_check(index);
+
+    if (index == HumongousIndex) {
+      return _humongous_dictionary.total_free_blocks();
+    }
+
+    ssize_t count = _free_chunks[index].count();
+    return count == -1 ? 0 : (size_t) count;
+  }
+
+  size_t size_free_chunks_in_bytes(ChunkIndex index) const {
+    index_bounds_check(index);
+
+    size_t word_size = 0;
+    if (index == HumongousIndex) {
+      word_size = _humongous_dictionary.total_size();
+    } else {
+      const size_t size_per_chunk_in_words = _free_chunks[index].size();
+      word_size = size_per_chunk_in_words * num_free_chunks(index);
+    }
+
+    return word_size * BytesPerWord;
+  }
+
+  MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
+    return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
+                                         num_free_chunks(SmallIndex),
+                                         num_free_chunks(MediumIndex),
+                                         num_free_chunks(HumongousIndex),
+                                         size_free_chunks_in_bytes(SpecializedIndex),
+                                         size_free_chunks_in_bytes(SmallIndex),
+                                         size_free_chunks_in_bytes(MediumIndex),
+                                         size_free_chunks_in_bytes(HumongousIndex));
+  }
+
+  // Debug support
+  void verify();
+  void slow_verify() {
+    if (VerifyMetaspace) {
+      verify();
+    }
+  }
+  void locked_verify();
+  void slow_locked_verify() {
+    if (VerifyMetaspace) {
+      locked_verify();
+    }
+  }
+
+  void locked_print_free_chunks(outputStream* st);
+  void locked_print_sum_free_chunks(outputStream* st);
+
+  // Fill in current statistic values to the given statistics object.
+  void collect_statistics(ChunkManagerStatistics* out) const;
+
+};
+
+} // namespace metaspace
+
+
+#endif /* SHARE_MEMORY_METASPACE_CHUNKMANAGER_HPP_ */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metaDebug.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "logging/log.hpp"
+#include "memory/metaspace/metaDebug.hpp"
+#include "runtime/os.hpp"
+#include "runtime/thread.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+int Metadebug::_allocation_fail_alot_count = 0;
+
+void Metadebug::init_allocation_fail_alot_count() {
+  if (MetadataAllocationFailALot) {
+    _allocation_fail_alot_count =
+      1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
+  }
+}
+
+#ifdef ASSERT
+bool Metadebug::test_metadata_failure() {
+  if (MetadataAllocationFailALot &&
+      Threads::is_vm_complete()) {
+    if (_allocation_fail_alot_count > 0) {
+      _allocation_fail_alot_count--;
+    } else {
+      log_trace(gc, metaspace, freelist)("Metadata allocation failing for MetadataAllocationFailALot");
+      init_allocation_fail_alot_count();
+      return true;
+    }
+  }
+  return false;
+}
+#endif
+
+
+} // namespace metaspace
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metaDebug.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_METADEBUG_HPP
+#define SHARE_MEMORY_METASPACE_METADEBUG_HPP
+
+#include "memory/allocation.hpp"
+
+namespace metaspace {
+
+class Metadebug : AllStatic {
+  // Debugging support for Metaspaces
+  static int _allocation_fail_alot_count;
+
+ public:
+
+  static void init_allocation_fail_alot_count();
+#ifdef ASSERT
+  static bool test_metadata_failure();
+#endif
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_METADEBUG_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metabase.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_METABASE_HPP
+#define SHARE_MEMORY_METASPACE_METABASE_HPP
+
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+// Super class of Metablock and Metachunk to allow them to
+// be put on the FreeList and in the BinaryTreeDictionary.
+template <class T>
+class Metabase {
+  size_t _word_size;
+  T*     _next;
+  T*     _prev;
+
+ protected:
+  Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {}
+
+ public:
+  T* next() const         { return _next; }
+  T* prev() const         { return _prev; }
+  void set_next(T* v)     { _next = v; assert(v != this, "Boom");}
+  void set_prev(T* v)     { _prev = v; assert(v != this, "Boom");}
+  void clear_next()       { set_next(NULL); }
+  void clear_prev()       { set_prev(NULL); }
+
+  size_t size() const volatile { return _word_size; }
+  void set_size(size_t v) { _word_size = v; }
+
+  void link_next(T* ptr)  { set_next(ptr); }
+  void link_prev(T* ptr)  { set_prev(ptr); }
+  void link_after(T* ptr) {
+    link_next(ptr);
+    if (ptr != NULL) ptr->link_prev((T*)this);
+  }
+
+  uintptr_t* end() const        { return ((uintptr_t*) this) + size(); }
+
+  bool cantCoalesce() const     { return false; }
+
+  // Debug support
+#ifdef ASSERT
+  void* prev_addr() const { return (void*)&_prev; }
+  void* next_addr() const { return (void*)&_next; }
+  void* size_addr() const { return (void*)&_word_size; }
+#endif
+  bool verify_chunk_in_free_list(T* tc) const { return true; }
+  bool verify_par_locked() { return true; }
+
+  void assert_is_mangled() const {/* Don't check "\*/}
+
+  bool is_free()                 { return true; }
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_METABASE_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metablock.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_METABLOCK_HPP
+#define SHARE_MEMORY_METASPACE_METABLOCK_HPP
+
+#include "memory/metaspace/metabase.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+// Metablock is the unit of allocation from a Chunk.
+//
+// A Metablock may be reused by its SpaceManager but are never moved between
+// SpaceManagers.  There is no explicit link to the Metachunk
+// from which it was allocated.  Metablock may be deallocated and
+// put on a freelist but the space is never freed, rather
+// the Metachunk it is a part of will be deallocated when it's
+// associated class loader is collected.
+
+class Metablock : public Metabase<Metablock> {
+  friend class VMStructs;
+ public:
+  Metablock(size_t word_size) : Metabase<Metablock>(word_size) {}
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_METABLOCK_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metachunk.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "memory/allocation.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/occupancyMap.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "utilities/align.hpp"
+#include "utilities/copy.hpp"
+#include "utilities/debug.hpp"
+
+namespace metaspace {
+
+size_t Metachunk::object_alignment() {
+  // Must align pointers and sizes to 8,
+  // so that 64 bit types get correctly aligned.
+  const size_t alignment = 8;
+
+  // Make sure that the Klass alignment also agree.
+  STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes);
+
+  return alignment;
+}
+
+size_t Metachunk::overhead() {
+  return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord;
+}
+
+// Metachunk methods
+
+Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size,
+                     VirtualSpaceNode* container)
+    : Metabase<Metachunk>(word_size),
+    _chunk_type(chunktype),
+    _is_class(is_class),
+    _sentinel(CHUNK_SENTINEL),
+    _origin(origin_normal),
+    _use_count(0),
+    _top(NULL),
+    _container(container)
+{
+  _top = initial_top();
+  set_is_tagged_free(false);
+#ifdef ASSERT
+  mangle(uninitMetaWordVal);
+  verify();
+#endif
+}
+
+MetaWord* Metachunk::allocate(size_t word_size) {
+  MetaWord* result = NULL;
+  // If available, bump the pointer to allocate.
+  if (free_word_size() >= word_size) {
+    result = _top;
+    _top = _top + word_size;
+  }
+  return result;
+}
+
+// _bottom points to the start of the chunk including the overhead.
+size_t Metachunk::used_word_size() const {
+  return pointer_delta(_top, bottom(), sizeof(MetaWord));
+}
+
+size_t Metachunk::free_word_size() const {
+  return pointer_delta(end(), _top, sizeof(MetaWord));
+}
+
+void Metachunk::print_on(outputStream* st) const {
+  st->print_cr("Metachunk:"
+               " bottom " PTR_FORMAT " top " PTR_FORMAT
+               " end " PTR_FORMAT " size " SIZE_FORMAT " (%s)",
+               p2i(bottom()), p2i(_top), p2i(end()), word_size(),
+               chunk_size_name(get_chunk_type()));
+  if (Verbose) {
+    st->print_cr("    used " SIZE_FORMAT " free " SIZE_FORMAT,
+                 used_word_size(), free_word_size());
+  }
+}
+
+#ifdef ASSERT
+void Metachunk::mangle(juint word_value) {
+  // Overwrite the payload of the chunk and not the links that
+  // maintain list of chunks.
+  HeapWord* start = (HeapWord*)initial_top();
+  size_t size = word_size() - overhead();
+  Copy::fill_to_words(start, size, word_value);
+}
+
+void Metachunk::verify() const {
+  assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this));
+  const ChunkIndex chunk_type = get_chunk_type();
+  assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this));
+  if (chunk_type != HumongousIndex) {
+    assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()),
+           "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.",
+           p2i(this), word_size(), chunk_size_name(chunk_type));
+  }
+  assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this));
+  assert(bottom() <= _top && _top <= (MetaWord*)end(),
+         "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this));
+
+  // For non-humongous chunks, starting address shall be aligned
+  // to its chunk size. Humongous chunks start address is
+  // aligned to specialized chunk size.
+  const size_t required_alignment =
+    (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord);
+  assert(is_aligned((address)this, required_alignment),
+         "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".",
+         p2i(this), word_size() * sizeof(MetaWord), required_alignment);
+}
+
+#endif // ASSERT
+
+// Helper, returns a descriptive name for the given index.
+const char* chunk_size_name(ChunkIndex index) {
+  switch (index) {
+    case SpecializedIndex:
+      return "specialized";
+    case SmallIndex:
+      return "small";
+    case MediumIndex:
+      return "medium";
+    case HumongousIndex:
+      return "humongous";
+    default:
+      return "Invalid index";
+  }
+}
+
+#ifdef ASSERT
+void do_verify_chunk(Metachunk* chunk) {
+  guarantee(chunk != NULL, "Sanity");
+  // Verify chunk itself; then verify that it is consistent with the
+  // occupany map of its containing node.
+  chunk->verify();
+  VirtualSpaceNode* const vsn = chunk->container();
+  OccupancyMap* const ocmap = vsn->occupancy_map();
+  ocmap->verify_for_chunk(chunk);
+}
+#endif
+
+void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) {
+  chunk->set_is_tagged_free(!inuse);
+  OccupancyMap* const ocmap = chunk->container()->occupancy_map();
+  ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse);
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/metachunk.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#ifndef SHARE_VM_MEMORY_METACHUNK_HPP
+#define SHARE_VM_MEMORY_METACHUNK_HPP
+
+#include "memory/metaspace/metabase.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class MetachunkTest;
+
+namespace metaspace {
+
+class VirtualSpaceNode;
+
+//  Metachunk - Quantum of allocation from a Virtualspace
+//    Metachunks are reused (when freed are put on a global freelist) and
+//    have no permanent association to a SpaceManager.
+
+//            +--------------+ <- end    --+       --+
+//            |              |             |         |
+//            |              |             | free    |
+//            |              |             |         |
+//            |              |             |         | size | capacity
+//            |              |             |         |
+//            |              | <- top   -- +         |
+//            |              |             |         |
+//            |              |             | used    |
+//            |              |             |         |
+//            |              |             |         |
+//            +--------------+ <- bottom --+       --+
+
+enum ChunkOrigin {
+  // Chunk normally born (via take_from_committed)
+  origin_normal = 1,
+  // Chunk was born as padding chunk
+  origin_pad = 2,
+  // Chunk was born as leftover chunk in VirtualSpaceNode::retire
+  origin_leftover = 3,
+  // Chunk was born as result of a merge of smaller chunks
+  origin_merge = 4,
+  // Chunk was born as result of a split of a larger chunk
+  origin_split = 5,
+
+  origin_minimum = origin_normal,
+  origin_maximum = origin_split,
+  origins_count = origin_maximum + 1
+};
+
+inline bool is_valid_chunkorigin(ChunkOrigin origin) {
+  return origin == origin_normal ||
+    origin == origin_pad ||
+    origin == origin_leftover ||
+    origin == origin_merge ||
+    origin == origin_split;
+}
+
+class Metachunk : public Metabase<Metachunk> {
+
+  friend class ::MetachunkTest;
+
+  // The VirtualSpaceNode containing this chunk.
+  VirtualSpaceNode* const _container;
+
+  // Current allocation top.
+  MetaWord* _top;
+
+  // A 32bit sentinel for debugging purposes.
+  enum { CHUNK_SENTINEL = 0x4d4554EF,  // "MET"
+         CHUNK_SENTINEL_INVALID = 0xFEEEEEEF
+  };
+
+  uint32_t _sentinel;
+
+  const ChunkIndex _chunk_type;
+  const bool _is_class;
+  // Whether the chunk is free (in freelist) or in use by some class loader.
+  bool _is_tagged_free;
+
+  ChunkOrigin _origin;
+  int _use_count;
+
+  MetaWord* initial_top() const { return (MetaWord*)this + overhead(); }
+  MetaWord* top() const         { return _top; }
+
+ public:
+  // Metachunks are allocated out of a MetadataVirtualSpace and
+  // and use some of its space to describe itself (plus alignment
+  // considerations).  Metadata is allocated in the rest of the chunk.
+  // This size is the overhead of maintaining the Metachunk within
+  // the space.
+
+  // Alignment of each allocation in the chunks.
+  static size_t object_alignment();
+
+  // Size of the Metachunk header, in words, including alignment.
+  static size_t overhead();
+
+  Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size, VirtualSpaceNode* container);
+
+  MetaWord* allocate(size_t word_size);
+
+  VirtualSpaceNode* container() const { return _container; }
+
+  MetaWord* bottom() const { return (MetaWord*) this; }
+
+  // Reset top to bottom so chunk can be reused.
+  void reset_empty() { _top = initial_top(); clear_next(); clear_prev(); }
+  bool is_empty() { return _top == initial_top(); }
+
+  // used (has been allocated)
+  // free (available for future allocations)
+  size_t word_size() const { return size(); }
+  size_t used_word_size() const;
+  size_t free_word_size() const;
+
+  bool is_tagged_free() { return _is_tagged_free; }
+  void set_is_tagged_free(bool v) { _is_tagged_free = v; }
+
+  bool contains(const void* ptr) { return bottom() <= ptr && ptr < _top; }
+
+  void print_on(outputStream* st) const;
+
+  bool is_valid_sentinel() const        { return _sentinel == CHUNK_SENTINEL; }
+  void remove_sentinel()                { _sentinel = CHUNK_SENTINEL_INVALID; }
+
+  int get_use_count() const             { return _use_count; }
+  void inc_use_count()                  { _use_count ++; }
+
+  ChunkOrigin get_origin() const        { return _origin; }
+  void set_origin(ChunkOrigin orig)     { _origin = orig; }
+
+  ChunkIndex get_chunk_type() const     { return _chunk_type; }
+  bool is_class() const                 { return _is_class; }
+
+  DEBUG_ONLY(void mangle(juint word_value);)
+  DEBUG_ONLY(void verify() const;)
+
+};
+
+
+// Helper function that does a bunch of checks for a chunk.
+DEBUG_ONLY(void do_verify_chunk(Metachunk* chunk);)
+
+// Given a Metachunk, update its in-use information (both in the
+// chunk and the occupancy map).
+void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse);
+
+} // namespace metaspace
+
+#endif  // SHARE_VM_MEMORY_METACHUNK_HPP
--- a/src/hotspot/share/memory/metaspace/metaspaceCommon.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace/metaspaceCommon.cpp	Mon May 21 11:33:59 2018 +0200
@@ -1,6 +1,5 @@
 /*
  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2018, SAP and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,11 +25,14 @@
 #include "precompiled.hpp"
 
 #include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/ostream.hpp"
 
 namespace metaspace {
-namespace internals {
+
+DEBUG_ONLY(internal_statistics_t g_internal_statistics;)
 
 // Print a size, in words, scaled.
 void print_scaled_words(outputStream* st, size_t word_size, size_t scale, int width) {
@@ -128,5 +130,70 @@
   }
 }
 
-} // namespace internals
+// Returns size of this chunk type.
+size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunktype, bool is_class) {
+  assert(is_valid_nonhumongous_chunktype(chunktype), "invalid chunk type.");
+  size_t size = 0;
+  if (is_class) {
+    switch(chunktype) {
+      case SpecializedIndex: size = ClassSpecializedChunk; break;
+      case SmallIndex: size = ClassSmallChunk; break;
+      case MediumIndex: size = ClassMediumChunk; break;
+      default:
+        ShouldNotReachHere();
+    }
+  } else {
+    switch(chunktype) {
+      case SpecializedIndex: size = SpecializedChunk; break;
+      case SmallIndex: size = SmallChunk; break;
+      case MediumIndex: size = MediumChunk; break;
+      default:
+        ShouldNotReachHere();
+    }
+  }
+  return size;
+}
+
+ChunkIndex get_chunk_type_by_size(size_t size, bool is_class) {
+  if (is_class) {
+    if (size == ClassSpecializedChunk) {
+      return SpecializedIndex;
+    } else if (size == ClassSmallChunk) {
+      return SmallIndex;
+    } else if (size == ClassMediumChunk) {
+      return MediumIndex;
+    } else if (size > ClassMediumChunk) {
+      // A valid humongous chunk size is a multiple of the smallest chunk size.
+      assert(is_aligned(size, ClassSpecializedChunk), "Invalid chunk size");
+      return HumongousIndex;
+    }
+  } else {
+    if (size == SpecializedChunk) {
+      return SpecializedIndex;
+    } else if (size == SmallChunk) {
+      return SmallIndex;
+    } else if (size == MediumChunk) {
+      return MediumIndex;
+    } else if (size > MediumChunk) {
+      // A valid humongous chunk size is a multiple of the smallest chunk size.
+      assert(is_aligned(size, SpecializedChunk), "Invalid chunk size");
+      return HumongousIndex;
+    }
+  }
+  ShouldNotReachHere();
+  return (ChunkIndex)-1;
+}
+
+ChunkIndex next_chunk_index(ChunkIndex i) {
+  assert(i < NumberOfInUseLists, "Out of bound");
+  return (ChunkIndex) (i+1);
+}
+
+ChunkIndex prev_chunk_index(ChunkIndex i) {
+  assert(i > ZeroIndex, "Out of bound");
+  return (ChunkIndex) (i-1);
+}
+
+
 } // namespace metaspace
+
--- a/src/hotspot/share/memory/metaspace/metaspaceCommon.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace/metaspaceCommon.hpp	Mon May 21 11:33:59 2018 +0200
@@ -22,16 +22,24 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP_
-#define SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP_
+#ifndef SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP
+#define SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP
 
+#include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 
-
 class outputStream;
 
 namespace metaspace {
-namespace internals {
+
+enum ChunkSizes {    // in words.
+  ClassSpecializedChunk = 128,
+  SpecializedChunk = 128,
+  ClassSmallChunk = 256,
+  SmallChunk = 512,
+  ClassMediumChunk = 4 * K,
+  MediumChunk = 8 * K
+};
 
 // Print a size, in words, scaled.
 void print_scaled_words(outputStream* st, size_t word_size, size_t scale = 0, int width = -1);
@@ -50,7 +58,70 @@
 // larger than 99% but not 100% are displayed as ">100%".
 void print_percentage(outputStream* st, size_t total, size_t part);
 
-} // namespace internals
+
+#define assert_is_aligned(value, alignment)                  \
+  assert(is_aligned((value), (alignment)),                   \
+         SIZE_FORMAT_HEX " is not aligned to "               \
+         SIZE_FORMAT, (size_t)(uintptr_t)value, (alignment))
+
+// Internal statistics.
+#ifdef ASSERT
+struct  internal_statistics_t {
+  // Number of allocations.
+  uintx num_allocs;
+  // Number of times a ClassLoaderMetaspace was born...
+  uintx num_metaspace_births;
+  // ... and died.
+  uintx num_metaspace_deaths;
+  // Number of times VirtualSpaceListNodes were created...
+  uintx num_vsnodes_created;
+  // ... and purged.
+  uintx num_vsnodes_purged;
+  // Number of times we expanded the committed section of the space.
+  uintx num_committed_space_expanded;
+  // Number of deallocations
+  uintx num_deallocs;
+  // Number of deallocations triggered from outside ("real" deallocations).
+  uintx num_external_deallocs;
+  // Number of times an allocation was satisfied from deallocated blocks.
+  uintx num_allocs_from_deallocated_blocks;
+};
+extern internal_statistics_t g_internal_statistics;
+#endif
+
+// ChunkIndex defines the type of chunk.
+// Chunk types differ by size: specialized < small < medium, chunks
+// larger than medium are humongous chunks of varying size.
+enum ChunkIndex {
+  ZeroIndex = 0,
+  SpecializedIndex = ZeroIndex,
+  SmallIndex = SpecializedIndex + 1,
+  MediumIndex = SmallIndex + 1,
+  HumongousIndex = MediumIndex + 1,
+  NumberOfFreeLists = 3,
+  NumberOfInUseLists = 4
+};
+
+// Utility functions.
+size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunk_type, bool is_class);
+ChunkIndex get_chunk_type_by_size(size_t size, bool is_class);
+
+ChunkIndex next_chunk_index(ChunkIndex i);
+ChunkIndex prev_chunk_index(ChunkIndex i);
+// Returns a descriptive name for a chunk type.
+const char* chunk_size_name(ChunkIndex index);
+
+// Verify chunk type.
+inline bool is_valid_chunktype(ChunkIndex index) {
+  return index == SpecializedIndex || index == SmallIndex ||
+         index == MediumIndex || index == HumongousIndex;
+}
+
+inline bool is_valid_nonhumongous_chunktype(ChunkIndex index) {
+  return is_valid_chunktype(index) && index != HumongousIndex;
+}
+
 } // namespace metaspace
 
-#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP_ */
+#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP */
+
--- a/src/hotspot/share/memory/metaspace/metaspaceDCmd.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace/metaspaceDCmd.hpp	Mon May 21 11:33:59 2018 +0200
@@ -22,8 +22,8 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_METASPACEDCMD_HPP_
-#define SHARE_MEMORY_METASPACE_METASPACEDCMD_HPP_
+#ifndef SHARE_MEMORY_METASPACE_METASPACEDCMD_HPP
+#define SHARE_MEMORY_METASPACE_METASPACEDCMD_HPP
 
 #include "services/diagnosticCommand.hpp"
 
@@ -61,4 +61,4 @@
 
 } // namespace metaspace
 
-#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP_ */
+#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP */
--- a/src/hotspot/share/memory/metaspace/metaspaceStatistics.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace/metaspaceStatistics.cpp	Mon May 21 11:33:59 2018 +0200
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2018, SAP and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,7 +24,7 @@
  */
 #include "precompiled.hpp"
 
-#include "memory/metachunk.hpp"
+#include "memory/metaspace/metachunk.hpp"
 #include "memory/metaspace/metaspaceCommon.hpp"
 #include "memory/metaspace/metaspaceStatistics.hpp"
 #include "utilities/debug.hpp"
@@ -32,7 +32,6 @@
 #include "utilities/ostream.hpp"
 
 namespace metaspace {
-namespace internals {
 
 // FreeChunksStatistics methods
 
@@ -271,8 +270,7 @@
   st->cr();
 }
 
-
-} // end namespace internals
 } // end namespace metaspace
 
 
+
--- a/src/hotspot/share/memory/metaspace/metaspaceStatistics.hpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/memory/metaspace/metaspaceStatistics.hpp	Mon May 21 11:33:59 2018 +0200
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2018, SAP and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,17 +23,16 @@
  *
  */
 
-#ifndef SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP_
-#define SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP_
+#ifndef SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP
+#define SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP
 
 #include "utilities/globalDefinitions.hpp"
-#include "memory/metachunk.hpp" // for ChunkIndex enum
 #include "memory/metaspace.hpp" // for MetadataType enum
+#include "memory/metaspace/metachunk.hpp" // for ChunkIndex enum
 
 class outputStream;
 
 namespace metaspace {
-namespace internals {
 
 // Contains statistics for a number of free chunks.
 class FreeChunksStatistics {
@@ -183,7 +182,7 @@
 
 }; // ClassLoaderMetaspaceStatistics
 
-} // namespace internals
 } // namespace metaspace
 
-#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP_ */
+#endif /* SHARE_MEMORY_METASPACE_METASPACESTATISTICS_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/occupancyMap.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018 SAP SE. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/occupancyMap.hpp"
+#include "runtime/os.hpp"
+
+namespace metaspace {
+
+OccupancyMap::OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) :
+            _reference_address(reference_address), _word_size(word_size),
+            _smallest_chunk_word_size(smallest_chunk_word_size)
+{
+  assert(reference_address != NULL, "invalid reference address");
+  assert(is_aligned(reference_address, smallest_chunk_word_size),
+      "Reference address not aligned to smallest chunk size.");
+  assert(is_aligned(word_size, smallest_chunk_word_size),
+      "Word_size shall be a multiple of the smallest chunk size.");
+  // Calculate bitmap size: one bit per smallest_chunk_word_size'd area.
+  size_t num_bits = word_size / smallest_chunk_word_size;
+  _map_size = (num_bits + 7) / 8;
+  assert(_map_size * 8 >= num_bits, "sanity");
+  _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal);
+  _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal);
+  assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed.");
+  memset(_map[1], 0, _map_size);
+  memset(_map[0], 0, _map_size);
+  // Sanity test: the first respectively last possible chunk start address in
+  // the covered range shall map to the first and last bit in the bitmap.
+  assert(get_bitpos_for_address(reference_address) == 0,
+      "First chunk address in range must map to fist bit in bitmap.");
+  assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1,
+      "Last chunk address in range must map to last bit in bitmap.");
+}
+
+OccupancyMap::~OccupancyMap() {
+  os::free(_map[0]);
+  os::free(_map[1]);
+}
+
+#ifdef ASSERT
+// Verify occupancy map for the address range [from, to).
+// We need to tell it the address range, because the memory the
+// occupancy map is covering may not be fully comitted yet.
+void OccupancyMap::verify(MetaWord* from, MetaWord* to) {
+  Metachunk* chunk = NULL;
+  int nth_bit_for_chunk = 0;
+  MetaWord* chunk_end = NULL;
+  for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) {
+    const unsigned pos = get_bitpos_for_address(p);
+    // Check the chunk-starts-info:
+    if (get_bit_at_position(pos, layer_chunk_start_map)) {
+      // Chunk start marked in bitmap.
+      chunk = (Metachunk*) p;
+      if (chunk_end != NULL) {
+        assert(chunk_end == p, "Unexpected chunk start found at %p (expected "
+            "the next chunk to start at %p).", p, chunk_end);
+      }
+      assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p);
+      if (chunk->get_chunk_type() != HumongousIndex) {
+        guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p);
+      }
+      chunk_end = p + chunk->word_size();
+      nth_bit_for_chunk = 0;
+      assert(chunk_end <= to, "Chunk end overlaps test address range.");
+    } else {
+      // No chunk start marked in bitmap.
+      assert(chunk != NULL, "Chunk should start at start of address range.");
+      assert(p < chunk_end, "Did not find expected chunk start at %p.", p);
+      nth_bit_for_chunk ++;
+    }
+    // Check the in-use-info:
+    const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map);
+    if (in_use_bit) {
+      assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).",
+          chunk, nth_bit_for_chunk);
+    } else {
+      assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).",
+          chunk, nth_bit_for_chunk);
+    }
+  }
+}
+
+// Verify that a given chunk is correctly accounted for in the bitmap.
+void OccupancyMap::verify_for_chunk(Metachunk* chunk) {
+  assert(chunk_starts_at_address((MetaWord*) chunk),
+      "No chunk start marked in map for chunk %p.", chunk);
+  // For chunks larger than the minimal chunk size, no other chunk
+  // must start in its area.
+  if (chunk->word_size() > _smallest_chunk_word_size) {
+    assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size,
+        chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map),
+        "No chunk must start within another chunk.");
+  }
+  if (!chunk->is_tagged_free()) {
+    assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()),
+        "Chunk %p is in use but marked as free in map (%d %d).",
+        chunk, chunk->get_chunk_type(), chunk->get_origin());
+  } else {
+    assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()),
+        "Chunk %p is free but marked as in-use in map (%d %d).",
+        chunk, chunk->get_chunk_type(), chunk->get_origin());
+  }
+}
+
+#endif // ASSERT
+
+} // namespace metaspace
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/occupancyMap.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,243 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018 SAP SE. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_OCCUPANCYMAP_HPP
+#define SHARE_MEMORY_METASPACE_OCCUPANCYMAP_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+
+namespace metaspace {
+
+class Metachunk;
+
+// Helper for Occupancy Bitmap. A type trait to give an all-bits-are-one-unsigned constant.
+template <typename T> struct all_ones  { static const T value; };
+template <> struct all_ones <uint64_t> { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; };
+template <> struct all_ones <uint32_t> { static const uint32_t value = 0xFFFFFFFF; };
+
+// The OccupancyMap is a bitmap which, for a given VirtualSpaceNode,
+// keeps information about
+// - where a chunk starts
+// - whether a chunk is in-use or free
+// A bit in this bitmap represents one range of memory in the smallest
+// chunk size (SpecializedChunk or ClassSpecializedChunk).
+class OccupancyMap : public CHeapObj<mtInternal> {
+
+  // The address range this map covers.
+  const MetaWord* const _reference_address;
+  const size_t _word_size;
+
+  // The word size of a specialized chunk, aka the number of words one
+  // bit in this map represents.
+  const size_t _smallest_chunk_word_size;
+
+  // map data
+  // Data are organized in two bit layers:
+  // The first layer is the chunk-start-map. Here, a bit is set to mark
+  // the corresponding region as the head of a chunk.
+  // The second layer is the in-use-map. Here, a set bit indicates that
+  // the corresponding belongs to a chunk which is in use.
+  uint8_t* _map[2];
+
+  enum { layer_chunk_start_map = 0, layer_in_use_map = 1 };
+
+  // length, in bytes, of bitmap data
+  size_t _map_size;
+
+  // Returns true if bit at position pos at bit-layer layer is set.
+  bool get_bit_at_position(unsigned pos, unsigned layer) const {
+    assert(layer == 0 || layer == 1, "Invalid layer %d", layer);
+    const unsigned byteoffset = pos / 8;
+    assert(byteoffset < _map_size,
+           "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
+    const unsigned mask = 1 << (pos % 8);
+    return (_map[layer][byteoffset] & mask) > 0;
+  }
+
+  // Changes bit at position pos at bit-layer layer to value v.
+  void set_bit_at_position(unsigned pos, unsigned layer, bool v) {
+    assert(layer == 0 || layer == 1, "Invalid layer %d", layer);
+    const unsigned byteoffset = pos / 8;
+    assert(byteoffset < _map_size,
+           "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
+    const unsigned mask = 1 << (pos % 8);
+    if (v) {
+      _map[layer][byteoffset] |= mask;
+    } else {
+      _map[layer][byteoffset] &= ~mask;
+    }
+  }
+
+  // Optimized case of is_any_bit_set_in_region for 32/64bit aligned access:
+  // pos is 32/64 aligned and num_bits is 32/64.
+  // This is the typical case when coalescing to medium chunks, whose size is
+  // 32 or 64 times the specialized chunk size (depending on class or non class
+  // case), so they occupy 64 bits which should be 64bit aligned, because
+  // chunks are chunk-size aligned.
+  template <typename T>
+  bool is_any_bit_set_in_region_3264(unsigned pos, unsigned num_bits, unsigned layer) const {
+    assert(_map_size > 0, "not initialized");
+    assert(layer == 0 || layer == 1, "Invalid layer %d.", layer);
+    assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned (%u).", pos);
+    assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u).", num_bits);
+    const size_t byteoffset = pos / 8;
+    assert(byteoffset <= (_map_size - sizeof(T)),
+           "Invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
+    const T w = *(T*)(_map[layer] + byteoffset);
+    return w > 0 ? true : false;
+  }
+
+  // Returns true if any bit in region [pos1, pos1 + num_bits) is set in bit-layer layer.
+  bool is_any_bit_set_in_region(unsigned pos, unsigned num_bits, unsigned layer) const {
+    if (pos % 32 == 0 && num_bits == 32) {
+      return is_any_bit_set_in_region_3264<uint32_t>(pos, num_bits, layer);
+    } else if (pos % 64 == 0 && num_bits == 64) {
+      return is_any_bit_set_in_region_3264<uint64_t>(pos, num_bits, layer);
+    } else {
+      for (unsigned n = 0; n < num_bits; n ++) {
+        if (get_bit_at_position(pos + n, layer)) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  // Returns true if any bit in region [p, p+word_size) is set in bit-layer layer.
+  bool is_any_bit_set_in_region(MetaWord* p, size_t word_size, unsigned layer) const {
+    assert(word_size % _smallest_chunk_word_size == 0,
+        "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size);
+    const unsigned pos = get_bitpos_for_address(p);
+    const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size);
+    return is_any_bit_set_in_region(pos, num_bits, layer);
+  }
+
+  // Optimized case of set_bits_of_region for 32/64bit aligned access:
+  // pos is 32/64 aligned and num_bits is 32/64.
+  // This is the typical case when coalescing to medium chunks, whose size
+  // is 32 or 64 times the specialized chunk size (depending on class or non
+  // class case), so they occupy 64 bits which should be 64bit aligned,
+  // because chunks are chunk-size aligned.
+  template <typename T>
+  void set_bits_of_region_T(unsigned pos, unsigned num_bits, unsigned layer, bool v) {
+    assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned to %u (%u).",
+           (unsigned)(sizeof(T) * 8), pos);
+    assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u), expected %u.",
+           num_bits, (unsigned)(sizeof(T) * 8));
+    const size_t byteoffset = pos / 8;
+    assert(byteoffset <= (_map_size - sizeof(T)),
+           "invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size);
+    T* const pw = (T*)(_map[layer] + byteoffset);
+    *pw = v ? all_ones<T>::value : (T) 0;
+  }
+
+  // Set all bits in a region starting at pos to a value.
+  void set_bits_of_region(unsigned pos, unsigned num_bits, unsigned layer, bool v) {
+    assert(_map_size > 0, "not initialized");
+    assert(layer == 0 || layer == 1, "Invalid layer %d.", layer);
+    if (pos % 32 == 0 && num_bits == 32) {
+      set_bits_of_region_T<uint32_t>(pos, num_bits, layer, v);
+    } else if (pos % 64 == 0 && num_bits == 64) {
+      set_bits_of_region_T<uint64_t>(pos, num_bits, layer, v);
+    } else {
+      for (unsigned n = 0; n < num_bits; n ++) {
+        set_bit_at_position(pos + n, layer, v);
+      }
+    }
+  }
+
+  // Helper: sets all bits in a region [p, p+word_size).
+  void set_bits_of_region(MetaWord* p, size_t word_size, unsigned layer, bool v) {
+    assert(word_size % _smallest_chunk_word_size == 0,
+        "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size);
+    const unsigned pos = get_bitpos_for_address(p);
+    const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size);
+    set_bits_of_region(pos, num_bits, layer, v);
+  }
+
+  // Helper: given an address, return the bit position representing that address.
+  unsigned get_bitpos_for_address(const MetaWord* p) const {
+    assert(_reference_address != NULL, "not initialized");
+    assert(p >= _reference_address && p < _reference_address + _word_size,
+           "Address %p out of range for occupancy map [%p..%p).",
+            p, _reference_address, _reference_address + _word_size);
+    assert(is_aligned(p, _smallest_chunk_word_size * sizeof(MetaWord)),
+           "Address not aligned (%p).", p);
+    const ptrdiff_t d = (p - _reference_address) / _smallest_chunk_word_size;
+    assert(d >= 0 && (size_t)d < _map_size * 8, "Sanity.");
+    return (unsigned) d;
+  }
+
+ public:
+
+  OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size);
+  ~OccupancyMap();
+
+  // Returns true if at address x a chunk is starting.
+  bool chunk_starts_at_address(MetaWord* p) const {
+    const unsigned pos = get_bitpos_for_address(p);
+    return get_bit_at_position(pos, layer_chunk_start_map);
+  }
+
+  void set_chunk_starts_at_address(MetaWord* p, bool v) {
+    const unsigned pos = get_bitpos_for_address(p);
+    set_bit_at_position(pos, layer_chunk_start_map, v);
+  }
+
+  // Removes all chunk-start-bits inside a region, typically as a
+  // result of a chunk merge.
+  void wipe_chunk_start_bits_in_region(MetaWord* p, size_t word_size) {
+    set_bits_of_region(p, word_size, layer_chunk_start_map, false);
+  }
+
+  // Returns true if there are life (in use) chunks in the region limited
+  // by [p, p+word_size).
+  bool is_region_in_use(MetaWord* p, size_t word_size) const {
+    return is_any_bit_set_in_region(p, word_size, layer_in_use_map);
+  }
+
+  // Marks the region starting at p with the size word_size as in use
+  // or free, depending on v.
+  void set_region_in_use(MetaWord* p, size_t word_size, bool v) {
+    set_bits_of_region(p, word_size, layer_in_use_map, v);
+  }
+
+  // Verify occupancy map for the address range [from, to).
+  // We need to tell it the address range, because the memory the
+  // occupancy map is covering may not be fully comitted yet.
+  DEBUG_ONLY(void verify(MetaWord* from, MetaWord* to);)
+
+  // Verify that a given chunk is correctly accounted for in the bitmap.
+  DEBUG_ONLY(void verify_for_chunk(Metachunk* chunk);)
+
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_OCCUPANCYMAP_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/printCLDMetaspaceInfoClosure.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#include "precompiled.hpp"
+#include "classfile/classLoaderData.hpp"
+#include "memory/metaspace/printCLDMetaspaceInfoClosure.hpp"
+#include "memory/resourceArea.hpp"
+#include "runtime/safepoint.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/ostream.hpp"
+
+
+namespace metaspace {
+
+PrintCLDMetaspaceInfoClosure::PrintCLDMetaspaceInfoClosure(outputStream* out, size_t scale, bool do_print, bool break_down_by_chunktype)
+: _out(out), _scale(scale), _do_print(do_print), _break_down_by_chunktype(break_down_by_chunktype)
+, _num_loaders(0)
+{
+  memset(_num_loaders_by_spacetype, 0, sizeof(_num_loaders_by_spacetype));
+}
+
+void PrintCLDMetaspaceInfoClosure::do_cld(ClassLoaderData* cld) {
+
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
+
+  ClassLoaderMetaspace* msp = cld->metaspace_or_null();
+  if (msp == NULL) {
+    return;
+  }
+
+  // Collect statistics for this class loader metaspace
+  ClassLoaderMetaspaceStatistics this_cld_stat;
+  msp->add_to_statistics(&this_cld_stat);
+
+  // And add it to the running totals
+  _stats_total.add(this_cld_stat);
+  _num_loaders ++;
+  _stats_by_spacetype[msp->space_type()].add(this_cld_stat);
+  _num_loaders_by_spacetype[msp->space_type()] ++;
+
+  // Optionally, print.
+  if (_do_print) {
+
+    _out->print(UINTX_FORMAT_W(4) ": ", _num_loaders);
+
+    if (cld->is_anonymous()) {
+      _out->print("ClassLoaderData " PTR_FORMAT " for anonymous class", p2i(cld));
+    } else {
+      ResourceMark rm;
+      _out->print("ClassLoaderData " PTR_FORMAT " for %s", p2i(cld), cld->loader_name());
+    }
+
+    if (cld->is_unloading()) {
+      _out->print(" (unloading)");
+    }
+
+    this_cld_stat.print_on(_out, _scale, _break_down_by_chunktype);
+    _out->cr();
+
+  }
+
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/printCLDMetaspaceInfoClosure.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_PRINTCLDMETASPACEINFOCLOSURE_HPP
+#define SHARE_MEMORY_METASPACE_PRINTCLDMETASPACEINFOCLOSURE_HPP
+
+#include "memory/iterator.hpp"
+#include "memory/metaspace.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+
+namespace metaspace {
+
+class PrintCLDMetaspaceInfoClosure : public CLDClosure {
+private:
+  outputStream* const _out;
+  const size_t        _scale;
+  const bool          _do_print;
+  const bool          _break_down_by_chunktype;
+
+public:
+
+  uintx                           _num_loaders;
+  ClassLoaderMetaspaceStatistics  _stats_total;
+
+  uintx                           _num_loaders_by_spacetype [Metaspace::MetaspaceTypeCount];
+  ClassLoaderMetaspaceStatistics  _stats_by_spacetype [Metaspace::MetaspaceTypeCount];
+
+  PrintCLDMetaspaceInfoClosure(outputStream* out, size_t scale, bool do_print, bool break_down_by_chunktype);
+  void do_cld(ClassLoaderData* cld);
+
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_PRINTCLDMETASPACEINFOCLOSURE_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/smallBlocks.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#include "precompiled.hpp"
+
+#include "memory/metaspace/smallBlocks.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/ostream.hpp"
+
+namespace metaspace {
+
+void SmallBlocks::print_on(outputStream* st) const {
+  st->print_cr("SmallBlocks:");
+  for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
+    uint k = i - _small_block_min_size;
+    st->print_cr("small_lists size " SIZE_FORMAT " count " SIZE_FORMAT, _small_lists[k].size(), _small_lists[k].count());
+  }
+}
+
+
+// Returns the total size, in words, of all blocks, across all block sizes.
+size_t SmallBlocks::total_size() const {
+  size_t result = 0;
+  for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
+    uint k = i - _small_block_min_size;
+    result = result + _small_lists[k].count() * _small_lists[k].size();
+  }
+  return result;
+}
+
+// Returns the total number of all blocks across all block sizes.
+uintx SmallBlocks::total_num_blocks() const {
+  uintx result = 0;
+  for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
+    uint k = i - _small_block_min_size;
+    result = result + _small_lists[k].count();
+  }
+  return result;
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/smallBlocks.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_SMALLBLOCKS_HPP
+#define SHARE_MEMORY_METASPACE_SMALLBLOCKS_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/binaryTreeDictionary.hpp"
+#include "memory/metaspace/metablock.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+
+namespace metaspace {
+
+class SmallBlocks : public CHeapObj<mtClass> {
+
+  const static uint _small_block_max_size = sizeof(TreeChunk<Metablock,  FreeList<Metablock> >)/HeapWordSize;
+  // Note: this corresponds to the imposed miminum allocation size, see SpaceManager::get_allocation_word_size()
+  const static uint _small_block_min_size = sizeof(Metablock)/HeapWordSize;
+
+private:
+  FreeList<Metablock> _small_lists[_small_block_max_size - _small_block_min_size];
+
+  FreeList<Metablock>& list_at(size_t word_size) {
+    assert(word_size >= _small_block_min_size, "There are no metaspace objects less than %u words", _small_block_min_size);
+    return _small_lists[word_size - _small_block_min_size];
+  }
+
+public:
+  SmallBlocks() {
+    for (uint i = _small_block_min_size; i < _small_block_max_size; i++) {
+      uint k = i - _small_block_min_size;
+      _small_lists[k].set_size(i);
+    }
+  }
+
+  // Returns the total size, in words, of all blocks, across all block sizes.
+  size_t total_size() const;
+
+  // Returns the total number of all blocks across all block sizes.
+  uintx total_num_blocks() const;
+
+  static uint small_block_max_size() { return _small_block_max_size; }
+  static uint small_block_min_size() { return _small_block_min_size; }
+
+  MetaWord* get_block(size_t word_size) {
+    if (list_at(word_size).count() > 0) {
+      MetaWord* new_block = (MetaWord*) list_at(word_size).get_chunk_at_head();
+      return new_block;
+    } else {
+      return NULL;
+    }
+  }
+  void return_block(Metablock* free_chunk, size_t word_size) {
+    list_at(word_size).return_chunk_at_head(free_chunk, false);
+    assert(list_at(word_size).count() > 0, "Should have a chunk");
+  }
+
+  void print_on(outputStream* st) const;
+
+};
+
+} // namespace metaspace
+
+
+#endif /* SHARE_MEMORY_METASPACE_SMALLBLOCKS_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/spaceManager.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,522 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#include "precompiled.hpp"
+
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaDebug.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/spaceManager.hpp"
+#include "memory/metaspace/virtualSpaceList.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/init.hpp"
+#include "services/memoryService.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+#define assert_counter(expected_value, real_value, msg) \
+  assert( (expected_value) == (real_value),             \
+         "Counter mismatch (%s): expected " SIZE_FORMAT \
+         ", but got: " SIZE_FORMAT ".", msg, expected_value, \
+         real_value);
+
+// SpaceManager methods
+
+size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) {
+  size_t chunk_sizes[] = {
+      specialized_chunk_size(is_class_space),
+      small_chunk_size(is_class_space),
+      medium_chunk_size(is_class_space)
+  };
+
+  // Adjust up to one of the fixed chunk sizes ...
+  for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) {
+    if (requested <= chunk_sizes[i]) {
+      return chunk_sizes[i];
+    }
+  }
+
+  // ... or return the size as a humongous chunk.
+  return requested;
+}
+
+size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const {
+  return adjust_initial_chunk_size(requested, is_class());
+}
+
+size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const {
+  size_t requested;
+
+  if (is_class()) {
+    switch (type) {
+    case Metaspace::BootMetaspaceType:       requested = Metaspace::first_class_chunk_word_size(); break;
+    case Metaspace::AnonymousMetaspaceType:  requested = ClassSpecializedChunk; break;
+    case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break;
+    default:                                 requested = ClassSmallChunk; break;
+    }
+  } else {
+    switch (type) {
+    case Metaspace::BootMetaspaceType:       requested = Metaspace::first_chunk_word_size(); break;
+    case Metaspace::AnonymousMetaspaceType:  requested = SpecializedChunk; break;
+    case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break;
+    default:                                 requested = SmallChunk; break;
+    }
+  }
+
+  // Adjust to one of the fixed chunk sizes (unless humongous)
+  const size_t adjusted = adjust_initial_chunk_size(requested);
+
+  assert(adjusted != 0, "Incorrect initial chunk size. Requested: "
+         SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted);
+
+  return adjusted;
+}
+
+void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
+
+  for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
+    st->print("SpaceManager: " UINTX_FORMAT " %s chunks.",
+        num_chunks_by_type(i), chunk_size_name(i));
+  }
+
+  chunk_manager()->locked_print_free_chunks(st);
+}
+
+size_t SpaceManager::calc_chunk_size(size_t word_size) {
+
+  // Decide between a small chunk and a medium chunk.  Up to
+  // _small_chunk_limit small chunks can be allocated.
+  // After that a medium chunk is preferred.
+  size_t chunk_word_size;
+
+  // Special case for anonymous metadata space.
+  // Anonymous metadata space is usually small, with majority within 1K - 2K range and
+  // rarely about 4K (64-bits JVM).
+  // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation
+  // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4)
+  // reduces space waste from 60+% to around 30%.
+  if ((_space_type == Metaspace::AnonymousMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) &&
+      _mdtype == Metaspace::NonClassType &&
+      num_chunks_by_type(SpecializedIndex) < anon_and_delegating_metadata_specialize_chunk_limit &&
+      word_size + Metachunk::overhead() <= SpecializedChunk) {
+    return SpecializedChunk;
+  }
+
+  if (num_chunks_by_type(MediumIndex) == 0 &&
+      num_chunks_by_type(SmallIndex) < small_chunk_limit) {
+    chunk_word_size = (size_t) small_chunk_size();
+    if (word_size + Metachunk::overhead() > small_chunk_size()) {
+      chunk_word_size = medium_chunk_size();
+    }
+  } else {
+    chunk_word_size = medium_chunk_size();
+  }
+
+  // Might still need a humongous chunk.  Enforce
+  // humongous allocations sizes to be aligned up to
+  // the smallest chunk size.
+  size_t if_humongous_sized_chunk =
+    align_up(word_size + Metachunk::overhead(),
+                  smallest_chunk_size());
+  chunk_word_size =
+    MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
+
+  assert(!SpaceManager::is_humongous(word_size) ||
+         chunk_word_size == if_humongous_sized_chunk,
+         "Size calculation is wrong, word_size " SIZE_FORMAT
+         " chunk_word_size " SIZE_FORMAT,
+         word_size, chunk_word_size);
+  Log(gc, metaspace, alloc) log;
+  if (log.is_debug() && SpaceManager::is_humongous(word_size)) {
+    log.debug("Metadata humongous allocation:");
+    log.debug("  word_size " PTR_FORMAT, word_size);
+    log.debug("  chunk_word_size " PTR_FORMAT, chunk_word_size);
+    log.debug("    chunk overhead " PTR_FORMAT, Metachunk::overhead());
+  }
+  return chunk_word_size;
+}
+
+void SpaceManager::track_metaspace_memory_usage() {
+  if (is_init_completed()) {
+    if (is_class()) {
+      MemoryService::track_compressed_class_memory_usage();
+    }
+    MemoryService::track_metaspace_memory_usage();
+  }
+}
+
+MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
+  assert_lock_strong(_lock);
+  assert(vs_list()->current_virtual_space() != NULL,
+         "Should have been set");
+  assert(current_chunk() == NULL ||
+         current_chunk()->allocate(word_size) == NULL,
+         "Don't need to expand");
+  MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
+
+  if (log_is_enabled(Trace, gc, metaspace, freelist)) {
+    size_t words_left = 0;
+    size_t words_used = 0;
+    if (current_chunk() != NULL) {
+      words_left = current_chunk()->free_word_size();
+      words_used = current_chunk()->used_word_size();
+    }
+    log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left",
+                                       word_size, words_used, words_left);
+  }
+
+  // Get another chunk
+  size_t chunk_word_size = calc_chunk_size(word_size);
+  Metachunk* next = get_new_chunk(chunk_word_size);
+
+  MetaWord* mem = NULL;
+
+  // If a chunk was available, add it to the in-use chunk list
+  // and do an allocation from it.
+  if (next != NULL) {
+    // Add to this manager's list of chunks in use.
+    // If the new chunk is humongous, it was created to serve a single large allocation. In that
+    // case it usually makes no sense to make it the current chunk, since the next allocation would
+    // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly
+    // good chunk which could be used for more normal allocations.
+    bool make_current = true;
+    if (next->get_chunk_type() == HumongousIndex &&
+        current_chunk() != NULL) {
+      make_current = false;
+    }
+    add_chunk(next, make_current);
+    mem = next->allocate(word_size);
+  }
+
+  // Track metaspace memory usage statistic.
+  track_metaspace_memory_usage();
+
+  return mem;
+}
+
+void SpaceManager::print_on(outputStream* st) const {
+  SpaceManagerStatistics stat;
+  add_to_statistics(&stat); // will lock _lock.
+  stat.print_on(st, 1*K, false);
+}
+
+SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
+                           Metaspace::MetaspaceType space_type,//
+                           Mutex* lock) :
+  _mdtype(mdtype),
+  _space_type(space_type),
+  _capacity_words(0),
+  _used_words(0),
+  _overhead_words(0),
+  _block_freelists(NULL),
+  _lock(lock),
+  _chunk_list(NULL),
+  _current_chunk(NULL)
+{
+  Metadebug::init_allocation_fail_alot_count();
+  memset(_num_chunks_by_type, 0, sizeof(_num_chunks_by_type));
+  log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this));
+}
+
+void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) {
+
+  assert_lock_strong(MetaspaceExpand_lock);
+
+  _capacity_words += new_chunk->word_size();
+  _overhead_words += Metachunk::overhead();
+  DEBUG_ONLY(new_chunk->verify());
+  _num_chunks_by_type[new_chunk->get_chunk_type()] ++;
+
+  // Adjust global counters:
+  MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size());
+  MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead());
+}
+
+void SpaceManager::account_for_allocation(size_t words) {
+  // Note: we should be locked with the ClassloaderData-specific metaspace lock.
+  // We may or may not be locked with the global metaspace expansion lock.
+  assert_lock_strong(lock());
+
+  // Add to the per SpaceManager totals. This can be done non-atomically.
+  _used_words += words;
+
+  // Adjust global counters. This will be done atomically.
+  MetaspaceUtils::inc_used(mdtype(), words);
+}
+
+void SpaceManager::account_for_spacemanager_death() {
+
+  assert_lock_strong(MetaspaceExpand_lock);
+
+  MetaspaceUtils::dec_capacity(mdtype(), _capacity_words);
+  MetaspaceUtils::dec_overhead(mdtype(), _overhead_words);
+  MetaspaceUtils::dec_used(mdtype(), _used_words);
+}
+
+SpaceManager::~SpaceManager() {
+
+  // This call this->_lock which can't be done while holding MetaspaceExpand_lock
+  DEBUG_ONLY(verify_metrics());
+
+  MutexLockerEx fcl(MetaspaceExpand_lock,
+                    Mutex::_no_safepoint_check_flag);
+
+  chunk_manager()->slow_locked_verify();
+
+  account_for_spacemanager_death();
+
+  Log(gc, metaspace, freelist) log;
+  if (log.is_trace()) {
+    log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this));
+    ResourceMark rm;
+    LogStream ls(log.trace());
+    locked_print_chunks_in_use_on(&ls);
+    if (block_freelists() != NULL) {
+      block_freelists()->print_on(&ls);
+    }
+  }
+
+  // Add all the chunks in use by this space manager
+  // to the global list of free chunks.
+
+  // Follow each list of chunks-in-use and add them to the
+  // free lists.  Each list is NULL terminated.
+  chunk_manager()->return_chunk_list(chunk_list());
+#ifdef ASSERT
+  _chunk_list = NULL;
+  _current_chunk = NULL;
+#endif
+
+  chunk_manager()->slow_locked_verify();
+
+  if (_block_freelists != NULL) {
+    delete _block_freelists;
+  }
+}
+
+void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
+  assert_lock_strong(lock());
+  // Allocations and deallocations are in raw_word_size
+  size_t raw_word_size = get_allocation_word_size(word_size);
+  // Lazily create a block_freelist
+  if (block_freelists() == NULL) {
+    _block_freelists = new BlockFreelist();
+  }
+  block_freelists()->return_block(p, raw_word_size);
+  DEBUG_ONLY(Atomic::inc(&(g_internal_statistics.num_deallocs)));
+}
+
+// Adds a chunk to the list of chunks in use.
+void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
+
+  assert_lock_strong(_lock);
+  assert(new_chunk != NULL, "Should not be NULL");
+  assert(new_chunk->next() == NULL, "Should not be on a list");
+
+  new_chunk->reset_empty();
+
+  // Find the correct list and and set the current
+  // chunk for that list.
+  ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size());
+
+  if (make_current) {
+    // If we are to make the chunk current, retire the old current chunk and replace
+    // it with the new chunk.
+    retire_current_chunk();
+    set_current_chunk(new_chunk);
+  }
+
+  // Add the new chunk at the head of its respective chunk list.
+  new_chunk->set_next(_chunk_list);
+  _chunk_list = new_chunk;
+
+  // Adjust counters.
+  account_for_new_chunk(new_chunk);
+
+  assert(new_chunk->is_empty(), "Not ready for reuse");
+  Log(gc, metaspace, freelist) log;
+  if (log.is_trace()) {
+    log.trace("SpaceManager::added chunk: ");
+    ResourceMark rm;
+    LogStream ls(log.trace());
+    new_chunk->print_on(&ls);
+    chunk_manager()->locked_print_free_chunks(&ls);
+  }
+}
+
+void SpaceManager::retire_current_chunk() {
+  if (current_chunk() != NULL) {
+    size_t remaining_words = current_chunk()->free_word_size();
+    if (remaining_words >= SmallBlocks::small_block_min_size()) {
+      MetaWord* ptr = current_chunk()->allocate(remaining_words);
+      deallocate(ptr, remaining_words);
+      account_for_allocation(remaining_words);
+    }
+  }
+}
+
+Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) {
+  // Get a chunk from the chunk freelist
+  Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size);
+
+  if (next == NULL) {
+    next = vs_list()->get_new_chunk(chunk_word_size,
+                                    medium_chunk_bunch());
+  }
+
+  Log(gc, metaspace, alloc) log;
+  if (log.is_debug() && next != NULL &&
+      SpaceManager::is_humongous(next->word_size())) {
+    log.debug("  new humongous chunk word size " PTR_FORMAT, next->word_size());
+  }
+
+  return next;
+}
+
+MetaWord* SpaceManager::allocate(size_t word_size) {
+  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
+  size_t raw_word_size = get_allocation_word_size(word_size);
+  BlockFreelist* fl =  block_freelists();
+  MetaWord* p = NULL;
+
+  DEBUG_ONLY(if (VerifyMetaspace) verify_metrics_locked());
+
+  // Allocation from the dictionary is expensive in the sense that
+  // the dictionary has to be searched for a size.  Don't allocate
+  // from the dictionary until it starts to get fat.  Is this
+  // a reasonable policy?  Maybe an skinny dictionary is fast enough
+  // for allocations.  Do some profiling.  JJJ
+  if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) {
+    p = fl->get_block(raw_word_size);
+    if (p != NULL) {
+      DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs_from_deallocated_blocks));
+    }
+  }
+  if (p == NULL) {
+    p = allocate_work(raw_word_size);
+  }
+
+  return p;
+}
+
+// Returns the address of spaced allocated for "word_size".
+// This methods does not know about blocks (Metablocks)
+MetaWord* SpaceManager::allocate_work(size_t word_size) {
+  assert_lock_strong(lock());
+#ifdef ASSERT
+  if (Metadebug::test_metadata_failure()) {
+    return NULL;
+  }
+#endif
+  // Is there space in the current chunk?
+  MetaWord* result = NULL;
+
+  if (current_chunk() != NULL) {
+    result = current_chunk()->allocate(word_size);
+  }
+
+  if (result == NULL) {
+    result = grow_and_allocate(word_size);
+  }
+
+  if (result != NULL) {
+    account_for_allocation(word_size);
+  }
+
+  return result;
+}
+
+void SpaceManager::verify() {
+  Metachunk* curr = chunk_list();
+  while (curr != NULL) {
+    DEBUG_ONLY(do_verify_chunk(curr);)
+    assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use.");
+    curr = curr->next();
+  }
+}
+
+void SpaceManager::verify_chunk_size(Metachunk* chunk) {
+  assert(is_humongous(chunk->word_size()) ||
+         chunk->word_size() == medium_chunk_size() ||
+         chunk->word_size() == small_chunk_size() ||
+         chunk->word_size() == specialized_chunk_size(),
+         "Chunk size is wrong");
+  return;
+}
+
+void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const {
+  assert_lock_strong(lock());
+  Metachunk* chunk = chunk_list();
+  while (chunk != NULL) {
+    UsedChunksStatistics& chunk_stat = out->chunk_stats(chunk->get_chunk_type());
+    chunk_stat.add_num(1);
+    chunk_stat.add_cap(chunk->word_size());
+    chunk_stat.add_overhead(Metachunk::overhead());
+    chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead());
+    if (chunk != current_chunk()) {
+      chunk_stat.add_waste(chunk->free_word_size());
+    } else {
+      chunk_stat.add_free(chunk->free_word_size());
+    }
+    chunk = chunk->next();
+  }
+  if (block_freelists() != NULL) {
+    out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size());
+  }
+}
+
+void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const {
+  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
+  add_to_statistics_locked(out);
+}
+
+#ifdef ASSERT
+void SpaceManager::verify_metrics_locked() const {
+  assert_lock_strong(lock());
+
+  SpaceManagerStatistics stat;
+  add_to_statistics_locked(&stat);
+
+  UsedChunksStatistics chunk_stats = stat.totals();
+
+  DEBUG_ONLY(chunk_stats.check_sanity());
+
+  assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words");
+  assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words");
+  assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words");
+}
+
+void SpaceManager::verify_metrics() const {
+  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
+  verify_metrics_locked();
+}
+#endif // ASSERT
+
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/spaceManager.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP
+#define SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/metaspace.hpp"
+#include "memory/metaspace/blockFreelist.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaspaceStatistics.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+class Mutex;
+
+namespace metaspace {
+
+//  SpaceManager - used by Metaspace to handle allocations
+class SpaceManager : public CHeapObj<mtClass> {
+  friend class ::ClassLoaderMetaspace;
+  friend class Metadebug;
+
+ private:
+
+  // protects allocations
+  Mutex* const _lock;
+
+  // Type of metadata allocated.
+  const Metaspace::MetadataType   _mdtype;
+
+  // Type of metaspace
+  const Metaspace::MetaspaceType  _space_type;
+
+  // List of chunks in use by this SpaceManager.  Allocations
+  // are done from the current chunk.  The list is used for deallocating
+  // chunks when the SpaceManager is freed.
+  Metachunk* _chunk_list;
+  Metachunk* _current_chunk;
+
+  enum {
+
+    // Maximum number of small chunks to allocate to a SpaceManager
+    small_chunk_limit = 4,
+
+    // Maximum number of specialize chunks to allocate for anonymous and delegating
+    // metadata space to a SpaceManager
+    anon_and_delegating_metadata_specialize_chunk_limit = 4,
+
+    allocation_from_dictionary_limit = 4 * K
+
+  };
+
+  // Some running counters, but lets keep their number small to not add to much to
+  // the per-classloader footprint.
+  // Note: capacity = used + free + waste + overhead. We do not keep running counters for
+  // free and waste. Their sum can be deduced from the three other values.
+  size_t _overhead_words;
+  size_t _capacity_words;
+  size_t _used_words;
+  uintx _num_chunks_by_type[NumberOfInUseLists];
+
+  // Free lists of blocks are per SpaceManager since they
+  // are assumed to be in chunks in use by the SpaceManager
+  // and all chunks in use by a SpaceManager are freed when
+  // the class loader using the SpaceManager is collected.
+  BlockFreelist* _block_freelists;
+
+ private:
+  // Accessors
+  Metachunk* chunk_list() const { return _chunk_list; }
+
+  BlockFreelist* block_freelists() const { return _block_freelists; }
+
+  Metaspace::MetadataType mdtype() { return _mdtype; }
+
+  VirtualSpaceList* vs_list()   const { return Metaspace::get_space_list(_mdtype); }
+  ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); }
+
+  Metachunk* current_chunk() const { return _current_chunk; }
+  void set_current_chunk(Metachunk* v) {
+    _current_chunk = v;
+  }
+
+  Metachunk* find_current_chunk(size_t word_size);
+
+  // Add chunk to the list of chunks in use
+  void add_chunk(Metachunk* v, bool make_current);
+  void retire_current_chunk();
+
+  Mutex* lock() const { return _lock; }
+
+  // Adds to the given statistic object. Expects to be locked with lock().
+  void add_to_statistics_locked(SpaceManagerStatistics* out) const;
+
+  // Verify internal counters against the current state. Expects to be locked with lock().
+  DEBUG_ONLY(void verify_metrics_locked() const;)
+
+ public:
+  SpaceManager(Metaspace::MetadataType mdtype,
+               Metaspace::MetaspaceType space_type,
+               Mutex* lock);
+  ~SpaceManager();
+
+  enum ChunkMultiples {
+    MediumChunkMultiple = 4
+  };
+
+  static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; }
+  static size_t small_chunk_size(bool is_class)       { return is_class ? ClassSmallChunk : SmallChunk; }
+  static size_t medium_chunk_size(bool is_class)      { return is_class ? ClassMediumChunk : MediumChunk; }
+
+  static size_t smallest_chunk_size(bool is_class)    { return specialized_chunk_size(is_class); }
+
+  // Accessors
+  bool is_class() const { return _mdtype == Metaspace::ClassType; }
+
+  size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); }
+  size_t small_chunk_size()       const { return small_chunk_size(is_class()); }
+  size_t medium_chunk_size()      const { return medium_chunk_size(is_class()); }
+
+  size_t smallest_chunk_size()    const { return smallest_chunk_size(is_class()); }
+
+  size_t medium_chunk_bunch()     const { return medium_chunk_size() * MediumChunkMultiple; }
+
+  bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
+
+  size_t capacity_words() const     { return _capacity_words; }
+  size_t used_words() const         { return _used_words; }
+  size_t overhead_words() const     { return _overhead_words; }
+
+  // Adjust local, global counters after a new chunk has been added.
+  void account_for_new_chunk(const Metachunk* new_chunk);
+
+  // Adjust local, global counters after space has been allocated from the current chunk.
+  void account_for_allocation(size_t words);
+
+  // Adjust global counters just before the SpaceManager dies, after all its chunks
+  // have been returned to the freelist.
+  void account_for_spacemanager_death();
+
+  // Adjust the initial chunk size to match one of the fixed chunk list sizes,
+  // or return the unadjusted size if the requested size is humongous.
+  static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space);
+  size_t adjust_initial_chunk_size(size_t requested) const;
+
+  // Get the initial chunks size for this metaspace type.
+  size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const;
+
+  // Todo: remove this once we have counters by chunk type.
+  uintx num_chunks_by_type(ChunkIndex chunk_type) const       { return _num_chunks_by_type[chunk_type]; }
+
+  Metachunk* get_new_chunk(size_t chunk_word_size);
+
+  // Block allocation and deallocation.
+  // Allocates a block from the current chunk
+  MetaWord* allocate(size_t word_size);
+
+  // Helper for allocations
+  MetaWord* allocate_work(size_t word_size);
+
+  // Returns a block to the per manager freelist
+  void deallocate(MetaWord* p, size_t word_size);
+
+  // Based on the allocation size and a minimum chunk size,
+  // returned chunk size (for expanding space for chunk allocation).
+  size_t calc_chunk_size(size_t allocation_word_size);
+
+  // Called when an allocation from the current chunk fails.
+  // Gets a new chunk (may require getting a new virtual space),
+  // and allocates from that chunk.
+  MetaWord* grow_and_allocate(size_t word_size);
+
+  // Notify memory usage to MemoryService.
+  void track_metaspace_memory_usage();
+
+  // debugging support.
+
+  void print_on(outputStream* st) const;
+  void locked_print_chunks_in_use_on(outputStream* st) const;
+
+  void verify();
+  void verify_chunk_size(Metachunk* chunk);
+
+  // This adjusts the size given to be greater than the minimum allocation size in
+  // words for data in metaspace.  Esentially the minimum size is currently 3 words.
+  size_t get_allocation_word_size(size_t word_size) {
+    size_t byte_size = word_size * BytesPerWord;
+
+    size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock));
+    raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment());
+
+    size_t raw_word_size = raw_bytes_size / BytesPerWord;
+    assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
+
+    return raw_word_size;
+  }
+
+  // Adds to the given statistic object.
+  void add_to_statistics(SpaceManagerStatistics* out) const;
+
+  // Verify internal counters against the current state.
+  DEBUG_ONLY(void verify_metrics() const;)
+
+};
+
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_SPACEMANAGER_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/virtualSpaceList.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,387 @@
+/*
+ * virtualSpaceList.cpp
+ *
+ *  Created on: May 6, 2018
+ *      Author: thomas
+ */
+
+
+#include "precompiled.hpp"
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/metaspace.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/virtualSpaceList.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/safepoint.hpp"
+
+namespace metaspace {
+
+
+VirtualSpaceList::~VirtualSpaceList() {
+  VirtualSpaceListIterator iter(virtual_space_list());
+  while (iter.repeat()) {
+    VirtualSpaceNode* vsl = iter.get_next();
+    delete vsl;
+  }
+}
+
+void VirtualSpaceList::inc_reserved_words(size_t v) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _reserved_words = _reserved_words + v;
+}
+void VirtualSpaceList::dec_reserved_words(size_t v) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _reserved_words = _reserved_words - v;
+}
+
+#define assert_committed_below_limit()                        \
+  assert(MetaspaceUtils::committed_bytes() <= MaxMetaspaceSize, \
+         "Too much committed memory. Committed: " SIZE_FORMAT \
+         " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
+          MetaspaceUtils::committed_bytes(), MaxMetaspaceSize);
+
+void VirtualSpaceList::inc_committed_words(size_t v) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _committed_words = _committed_words + v;
+
+  assert_committed_below_limit();
+}
+void VirtualSpaceList::dec_committed_words(size_t v) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _committed_words = _committed_words - v;
+
+  assert_committed_below_limit();
+}
+
+void VirtualSpaceList::inc_virtual_space_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _virtual_space_count++;
+}
+
+void VirtualSpaceList::dec_virtual_space_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _virtual_space_count--;
+}
+
+// Walk the list of VirtualSpaceNodes and delete
+// nodes with a 0 container_count.  Remove Metachunks in
+// the node from their respective freelists.
+void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
+  assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work");
+  assert_lock_strong(MetaspaceExpand_lock);
+  // Don't use a VirtualSpaceListIterator because this
+  // list is being changed and a straightforward use of an iterator is not safe.
+  VirtualSpaceNode* purged_vsl = NULL;
+  VirtualSpaceNode* prev_vsl = virtual_space_list();
+  VirtualSpaceNode* next_vsl = prev_vsl;
+  while (next_vsl != NULL) {
+    VirtualSpaceNode* vsl = next_vsl;
+    DEBUG_ONLY(vsl->verify_container_count();)
+    next_vsl = vsl->next();
+    // Don't free the current virtual space since it will likely
+    // be needed soon.
+    if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
+      log_trace(gc, metaspace, freelist)("Purging VirtualSpaceNode " PTR_FORMAT " (capacity: " SIZE_FORMAT
+                                         ", used: " SIZE_FORMAT ").", p2i(vsl), vsl->capacity_words_in_vs(), vsl->used_words_in_vs());
+      DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_purged));
+      // Unlink it from the list
+      if (prev_vsl == vsl) {
+        // This is the case of the current node being the first node.
+        assert(vsl == virtual_space_list(), "Expected to be the first node");
+        set_virtual_space_list(vsl->next());
+      } else {
+        prev_vsl->set_next(vsl->next());
+      }
+
+      vsl->purge(chunk_manager);
+      dec_reserved_words(vsl->reserved_words());
+      dec_committed_words(vsl->committed_words());
+      dec_virtual_space_count();
+      purged_vsl = vsl;
+      delete vsl;
+    } else {
+      prev_vsl = vsl;
+    }
+  }
+#ifdef ASSERT
+  if (purged_vsl != NULL) {
+    // List should be stable enough to use an iterator here.
+    VirtualSpaceListIterator iter(virtual_space_list());
+    while (iter.repeat()) {
+      VirtualSpaceNode* vsl = iter.get_next();
+      assert(vsl != purged_vsl, "Purge of vsl failed");
+    }
+  }
+#endif
+}
+
+
+// This function looks at the mmap regions in the metaspace without locking.
+// The chunks are added with store ordering and not deleted except for at
+// unloading time during a safepoint.
+bool VirtualSpaceList::contains(const void* ptr) {
+  // List should be stable enough to use an iterator here because removing virtual
+  // space nodes is only allowed at a safepoint.
+  VirtualSpaceListIterator iter(virtual_space_list());
+  while (iter.repeat()) {
+    VirtualSpaceNode* vsn = iter.get_next();
+    if (vsn->contains(ptr)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void VirtualSpaceList::retire_current_virtual_space() {
+  assert_lock_strong(MetaspaceExpand_lock);
+
+  VirtualSpaceNode* vsn = current_virtual_space();
+
+  ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() :
+                                  Metaspace::chunk_manager_metadata();
+
+  vsn->retire(cm);
+}
+
+VirtualSpaceList::VirtualSpaceList(size_t word_size) :
+                                   _is_class(false),
+                                   _virtual_space_list(NULL),
+                                   _current_virtual_space(NULL),
+                                   _reserved_words(0),
+                                   _committed_words(0),
+                                   _virtual_space_count(0) {
+  MutexLockerEx cl(MetaspaceExpand_lock,
+                   Mutex::_no_safepoint_check_flag);
+  create_new_virtual_space(word_size);
+}
+
+VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
+                                   _is_class(true),
+                                   _virtual_space_list(NULL),
+                                   _current_virtual_space(NULL),
+                                   _reserved_words(0),
+                                   _committed_words(0),
+                                   _virtual_space_count(0) {
+  MutexLockerEx cl(MetaspaceExpand_lock,
+                   Mutex::_no_safepoint_check_flag);
+  VirtualSpaceNode* class_entry = new VirtualSpaceNode(is_class(), rs);
+  bool succeeded = class_entry->initialize();
+  if (succeeded) {
+    link_vs(class_entry);
+  }
+}
+
+size_t VirtualSpaceList::free_bytes() {
+  return current_virtual_space()->free_words_in_vs() * BytesPerWord;
+}
+
+// Allocate another meta virtual space and add it to the list.
+bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
+  assert_lock_strong(MetaspaceExpand_lock);
+
+  if (is_class()) {
+    assert(false, "We currently don't support more than one VirtualSpace for"
+                  " the compressed class space. The initialization of the"
+                  " CCS uses another code path and should not hit this path.");
+    return false;
+  }
+
+  if (vs_word_size == 0) {
+    assert(false, "vs_word_size should always be at least _reserve_alignment large.");
+    return false;
+  }
+
+  // Reserve the space
+  size_t vs_byte_size = vs_word_size * BytesPerWord;
+  assert_is_aligned(vs_byte_size, Metaspace::reserve_alignment());
+
+  // Allocate the meta virtual space and initialize it.
+  VirtualSpaceNode* new_entry = new VirtualSpaceNode(is_class(), vs_byte_size);
+  if (!new_entry->initialize()) {
+    delete new_entry;
+    return false;
+  } else {
+    assert(new_entry->reserved_words() == vs_word_size,
+        "Reserved memory size differs from requested memory size");
+    // ensure lock-free iteration sees fully initialized node
+    OrderAccess::storestore();
+    link_vs(new_entry);
+    DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_created));
+    return true;
+  }
+}
+
+void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
+  if (virtual_space_list() == NULL) {
+      set_virtual_space_list(new_entry);
+  } else {
+    current_virtual_space()->set_next(new_entry);
+  }
+  set_current_virtual_space(new_entry);
+  inc_reserved_words(new_entry->reserved_words());
+  inc_committed_words(new_entry->committed_words());
+  inc_virtual_space_count();
+#ifdef ASSERT
+  new_entry->mangle();
+#endif
+  LogTarget(Trace, gc, metaspace) lt;
+  if (lt.is_enabled()) {
+    LogStream ls(lt);
+    VirtualSpaceNode* vsl = current_virtual_space();
+    ResourceMark rm;
+    vsl->print_on(&ls);
+  }
+}
+
+bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
+                                      size_t min_words,
+                                      size_t preferred_words) {
+  size_t before = node->committed_words();
+
+  bool result = node->expand_by(min_words, preferred_words);
+
+  size_t after = node->committed_words();
+
+  // after and before can be the same if the memory was pre-committed.
+  assert(after >= before, "Inconsistency");
+  inc_committed_words(after - before);
+
+  return result;
+}
+
+bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
+  assert_is_aligned(min_words,       Metaspace::commit_alignment_words());
+  assert_is_aligned(preferred_words, Metaspace::commit_alignment_words());
+  assert(min_words <= preferred_words, "Invalid arguments");
+
+  const char* const class_or_not = (is_class() ? "class" : "non-class");
+
+  if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
+    log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list.",
+              class_or_not);
+    return  false;
+  }
+
+  size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
+  if (allowed_expansion_words < min_words) {
+    log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list (must try gc first).",
+              class_or_not);
+    return false;
+  }
+
+  size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
+
+  // Commit more memory from the the current virtual space.
+  bool vs_expanded = expand_node_by(current_virtual_space(),
+                                    min_words,
+                                    max_expansion_words);
+  if (vs_expanded) {
+     log_trace(gc, metaspace, freelist)("Expanded %s virtual space list.",
+               class_or_not);
+     return true;
+  }
+  log_trace(gc, metaspace, freelist)("%s virtual space list: retire current node.",
+            class_or_not);
+  retire_current_virtual_space();
+
+  // Get another virtual space.
+  size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
+  grow_vs_words = align_up(grow_vs_words, Metaspace::reserve_alignment_words());
+
+  if (create_new_virtual_space(grow_vs_words)) {
+    if (current_virtual_space()->is_pre_committed()) {
+      // The memory was pre-committed, so we are done here.
+      assert(min_words <= current_virtual_space()->committed_words(),
+          "The new VirtualSpace was pre-committed, so it"
+          "should be large enough to fit the alloc request.");
+      return true;
+    }
+
+    return expand_node_by(current_virtual_space(),
+                          min_words,
+                          max_expansion_words);
+  }
+
+  return false;
+}
+
+// Given a chunk, calculate the largest possible padding space which
+// could be required when allocating it.
+static size_t largest_possible_padding_size_for_chunk(size_t chunk_word_size, bool is_class) {
+  const ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class);
+  if (chunk_type != HumongousIndex) {
+    // Normal, non-humongous chunks are allocated at chunk size
+    // boundaries, so the largest padding space required would be that
+    // minus the smallest chunk size.
+    const size_t smallest_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk;
+    return chunk_word_size - smallest_chunk_size;
+  } else {
+    // Humongous chunks are allocated at smallest-chunksize
+    // boundaries, so there is no padding required.
+    return 0;
+  }
+}
+
+
+Metachunk* VirtualSpaceList::get_new_chunk(size_t chunk_word_size, size_t suggested_commit_granularity) {
+
+  // Allocate a chunk out of the current virtual space.
+  Metachunk* next = current_virtual_space()->get_chunk_vs(chunk_word_size);
+
+  if (next != NULL) {
+    return next;
+  }
+
+  // The expand amount is currently only determined by the requested sizes
+  // and not how much committed memory is left in the current virtual space.
+
+  // We must have enough space for the requested size and any
+  // additional reqired padding chunks.
+  const size_t size_for_padding = largest_possible_padding_size_for_chunk(chunk_word_size, this->is_class());
+
+  size_t min_word_size       = align_up(chunk_word_size + size_for_padding, Metaspace::commit_alignment_words());
+  size_t preferred_word_size = align_up(suggested_commit_granularity, Metaspace::commit_alignment_words());
+  if (min_word_size >= preferred_word_size) {
+    // Can happen when humongous chunks are allocated.
+    preferred_word_size = min_word_size;
+  }
+
+  bool expanded = expand_by(min_word_size, preferred_word_size);
+  if (expanded) {
+    next = current_virtual_space()->get_chunk_vs(chunk_word_size);
+    assert(next != NULL, "The allocation was expected to succeed after the expansion");
+  }
+
+   return next;
+}
+
+void VirtualSpaceList::print_on(outputStream* st, size_t scale) const {
+  st->print_cr(SIZE_FORMAT " nodes, current node: " PTR_FORMAT,
+      _virtual_space_count, p2i(_current_virtual_space));
+  VirtualSpaceListIterator iter(virtual_space_list());
+  while (iter.repeat()) {
+    st->cr();
+    VirtualSpaceNode* node = iter.get_next();
+    node->print_on(st, scale);
+  }
+}
+
+void VirtualSpaceList::print_map(outputStream* st) const {
+  VirtualSpaceNode* list = virtual_space_list();
+  VirtualSpaceListIterator iter(list);
+  unsigned i = 0;
+  while (iter.repeat()) {
+    st->print_cr("Node %u:", i);
+    VirtualSpaceNode* node = iter.get_next();
+    node->print_map(st, this->is_class());
+    i ++;
+  }
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/virtualSpaceList.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_VIRTUALSPACELIST_HPP
+#define SHARE_MEMORY_METASPACE_VIRTUALSPACELIST_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+
+namespace metaspace {
+
+class Metachunk;
+class ChunkManager;
+
+// List of VirtualSpaces for metadata allocation.
+class VirtualSpaceList : public CHeapObj<mtClass> {
+  friend class VirtualSpaceNode;
+
+  enum VirtualSpaceSizes {
+    VirtualSpaceSize = 256 * K
+  };
+
+  // Head of the list
+  VirtualSpaceNode* _virtual_space_list;
+  // virtual space currently being used for allocations
+  VirtualSpaceNode* _current_virtual_space;
+
+  // Is this VirtualSpaceList used for the compressed class space
+  bool _is_class;
+
+  // Sum of reserved and committed memory in the virtual spaces
+  size_t _reserved_words;
+  size_t _committed_words;
+
+  // Number of virtual spaces
+  size_t _virtual_space_count;
+
+  ~VirtualSpaceList();
+
+  VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
+
+  void set_virtual_space_list(VirtualSpaceNode* v) {
+    _virtual_space_list = v;
+  }
+  void set_current_virtual_space(VirtualSpaceNode* v) {
+    _current_virtual_space = v;
+  }
+
+  void link_vs(VirtualSpaceNode* new_entry);
+
+  // Get another virtual space and add it to the list.  This
+  // is typically prompted by a failed attempt to allocate a chunk
+  // and is typically followed by the allocation of a chunk.
+  bool create_new_virtual_space(size_t vs_word_size);
+
+  // Chunk up the unused committed space in the current
+  // virtual space and add the chunks to the free list.
+  void retire_current_virtual_space();
+
+ public:
+  VirtualSpaceList(size_t word_size);
+  VirtualSpaceList(ReservedSpace rs);
+
+  size_t free_bytes();
+
+  Metachunk* get_new_chunk(size_t chunk_word_size,
+                           size_t suggested_commit_granularity);
+
+  bool expand_node_by(VirtualSpaceNode* node,
+                      size_t min_words,
+                      size_t preferred_words);
+
+  bool expand_by(size_t min_words,
+                 size_t preferred_words);
+
+  VirtualSpaceNode* current_virtual_space() {
+    return _current_virtual_space;
+  }
+
+  bool is_class() const { return _is_class; }
+
+  bool initialization_succeeded() { return _virtual_space_list != NULL; }
+
+  size_t reserved_words()  { return _reserved_words; }
+  size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
+  size_t committed_words() { return _committed_words; }
+  size_t committed_bytes() { return committed_words() * BytesPerWord; }
+
+  void inc_reserved_words(size_t v);
+  void dec_reserved_words(size_t v);
+  void inc_committed_words(size_t v);
+  void dec_committed_words(size_t v);
+  void inc_virtual_space_count();
+  void dec_virtual_space_count();
+
+  bool contains(const void* ptr);
+
+  // Unlink empty VirtualSpaceNodes and free it.
+  void purge(ChunkManager* chunk_manager);
+
+  void print_on(outputStream* st) const                 { print_on(st, K); }
+  void print_on(outputStream* st, size_t scale) const;
+  void print_map(outputStream* st) const;
+
+  class VirtualSpaceListIterator : public StackObj {
+    VirtualSpaceNode* _virtual_spaces;
+   public:
+    VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
+      _virtual_spaces(virtual_spaces) {}
+
+    bool repeat() {
+      return _virtual_spaces != NULL;
+    }
+
+    VirtualSpaceNode* get_next() {
+      VirtualSpaceNode* result = _virtual_spaces;
+      if (_virtual_spaces != NULL) {
+        _virtual_spaces = _virtual_spaces->next();
+      }
+      return result;
+    }
+  };
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_VIRTUALSPACELIST_HPP */
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/virtualSpaceNode.cpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,596 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/metaspace/metachunk.hpp"
+#include "memory/metaspace.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
+#include "memory/metaspace/occupancyMap.hpp"
+#include "memory/metaspace/virtualSpaceNode.hpp"
+#include "memory/virtualspace.hpp"
+#include "runtime/os.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/copy.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+namespace metaspace {
+
+// Decide if large pages should be committed when the memory is reserved.
+static bool should_commit_large_pages_when_reserving(size_t bytes) {
+  if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) {
+    size_t words = bytes / BytesPerWord;
+    bool is_class = false; // We never reserve large pages for the class space.
+    if (MetaspaceGC::can_expand(words, is_class) &&
+        MetaspaceGC::allowed_expansion() >= words) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+// byte_size is the size of the associated virtualspace.
+VirtualSpaceNode::VirtualSpaceNode(bool is_class, size_t bytes) :
+    _is_class(is_class), _top(NULL), _next(NULL), _rs(), _container_count(0), _occupancy_map(NULL) {
+  assert_is_aligned(bytes, Metaspace::reserve_alignment());
+  bool large_pages = should_commit_large_pages_when_reserving(bytes);
+  _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
+
+  if (_rs.is_reserved()) {
+    assert(_rs.base() != NULL, "Catch if we get a NULL address");
+    assert(_rs.size() != 0, "Catch if we get a 0 size");
+    assert_is_aligned(_rs.base(), Metaspace::reserve_alignment());
+    assert_is_aligned(_rs.size(), Metaspace::reserve_alignment());
+
+    MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
+  }
+}
+
+void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
+  DEBUG_ONLY(this->verify();)
+    Metachunk* chunk = first_chunk();
+  Metachunk* invalid_chunk = (Metachunk*) top();
+  while (chunk < invalid_chunk ) {
+    assert(chunk->is_tagged_free(), "Should be tagged free");
+    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
+    chunk_manager->remove_chunk(chunk);
+    chunk->remove_sentinel();
+    assert(chunk->next() == NULL &&
+        chunk->prev() == NULL,
+        "Was not removed from its list");
+    chunk = (Metachunk*) next;
+  }
+}
+
+void VirtualSpaceNode::print_map(outputStream* st, bool is_class) const {
+
+  if (bottom() == top()) {
+    return;
+  }
+
+  const size_t spec_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk;
+  const size_t small_chunk_size = is_class ? ClassSmallChunk : SmallChunk;
+  const size_t med_chunk_size = is_class ? ClassMediumChunk : MediumChunk;
+
+  int line_len = 100;
+  const size_t section_len = align_up(spec_chunk_size * line_len, med_chunk_size);
+  line_len = (int)(section_len / spec_chunk_size);
+
+  static const int NUM_LINES = 4;
+
+  char* lines[NUM_LINES];
+  for (int i = 0; i < NUM_LINES; i ++) {
+    lines[i] = (char*)os::malloc(line_len, mtInternal);
+  }
+  int pos = 0;
+  const MetaWord* p = bottom();
+  const Metachunk* chunk = (const Metachunk*)p;
+  const MetaWord* chunk_end = p + chunk->word_size();
+  while (p < top()) {
+    if (pos == line_len) {
+      pos = 0;
+      for (int i = 0; i < NUM_LINES; i ++) {
+        st->fill_to(22);
+        st->print_raw(lines[i], line_len);
+        st->cr();
+      }
+    }
+    if (pos == 0) {
+      st->print(PTR_FORMAT ":", p2i(p));
+    }
+    if (p == chunk_end) {
+      chunk = (Metachunk*)p;
+      chunk_end = p + chunk->word_size();
+    }
+    // line 1: chunk starting points (a dot if that area is a chunk start).
+    lines[0][pos] = p == (const MetaWord*)chunk ? '.' : ' ';
+
+    // Line 2: chunk type (x=spec, s=small, m=medium, h=humongous), uppercase if
+    // chunk is in use.
+    const bool chunk_is_free = ((Metachunk*)chunk)->is_tagged_free();
+    if (chunk->word_size() == spec_chunk_size) {
+      lines[1][pos] = chunk_is_free ? 'x' : 'X';
+    } else if (chunk->word_size() == small_chunk_size) {
+      lines[1][pos] = chunk_is_free ? 's' : 'S';
+    } else if (chunk->word_size() == med_chunk_size) {
+      lines[1][pos] = chunk_is_free ? 'm' : 'M';
+    } else if (chunk->word_size() > med_chunk_size) {
+      lines[1][pos] = chunk_is_free ? 'h' : 'H';
+    } else {
+      ShouldNotReachHere();
+    }
+
+    // Line 3: chunk origin
+    const ChunkOrigin origin = chunk->get_origin();
+    lines[2][pos] = origin == origin_normal ? ' ' : '0' + (int) origin;
+
+    // Line 4: Virgin chunk? Virgin chunks are chunks created as a byproduct of padding or splitting,
+    //         but were never used.
+    lines[3][pos] = chunk->get_use_count() > 0 ? ' ' : 'v';
+
+    p += spec_chunk_size;
+    pos ++;
+  }
+  if (pos > 0) {
+    for (int i = 0; i < NUM_LINES; i ++) {
+      st->fill_to(22);
+      st->print_raw(lines[i], line_len);
+      st->cr();
+    }
+  }
+  for (int i = 0; i < NUM_LINES; i ++) {
+    os::free(lines[i]);
+  }
+}
+
+
+#ifdef ASSERT
+uintx VirtualSpaceNode::container_count_slow() {
+  uintx count = 0;
+  Metachunk* chunk = first_chunk();
+  Metachunk* invalid_chunk = (Metachunk*) top();
+  while (chunk < invalid_chunk ) {
+    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
+    do_verify_chunk(chunk);
+    // Don't count the chunks on the free lists.  Those are
+    // still part of the VirtualSpaceNode but not currently
+    // counted.
+    if (!chunk->is_tagged_free()) {
+      count++;
+    }
+    chunk = (Metachunk*) next;
+  }
+  return count;
+}
+#endif
+
+#ifdef ASSERT
+// Verify counters, all chunks in this list node and the occupancy map.
+void VirtualSpaceNode::verify() {
+  uintx num_in_use_chunks = 0;
+  Metachunk* chunk = first_chunk();
+  Metachunk* invalid_chunk = (Metachunk*) top();
+
+  // Iterate the chunks in this node and verify each chunk.
+  while (chunk < invalid_chunk ) {
+    DEBUG_ONLY(do_verify_chunk(chunk);)
+      if (!chunk->is_tagged_free()) {
+        num_in_use_chunks ++;
+      }
+    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
+    chunk = (Metachunk*) next;
+  }
+  assert(_container_count == num_in_use_chunks, "Container count mismatch (real: " UINTX_FORMAT
+      ", counter: " UINTX_FORMAT ".", num_in_use_chunks, _container_count);
+  // Also verify the occupancy map.
+  occupancy_map()->verify(this->bottom(), this->top());
+}
+#endif // ASSERT
+
+#ifdef ASSERT
+// Verify that all free chunks in this node are ideally merged
+// (there not should be multiple small chunks where a large chunk could exist.)
+void VirtualSpaceNode::verify_free_chunks_are_ideally_merged() {
+  Metachunk* chunk = first_chunk();
+  Metachunk* invalid_chunk = (Metachunk*) top();
+  // Shorthands.
+  const size_t size_med = (is_class() ? ClassMediumChunk : MediumChunk) * BytesPerWord;
+  const size_t size_small = (is_class() ? ClassSmallChunk : SmallChunk) * BytesPerWord;
+  int num_free_chunks_since_last_med_boundary = -1;
+  int num_free_chunks_since_last_small_boundary = -1;
+  while (chunk < invalid_chunk ) {
+    // Test for missed chunk merge opportunities: count number of free chunks since last chunk boundary.
+    // Reset the counter when encountering a non-free chunk.
+    if (chunk->get_chunk_type() != HumongousIndex) {
+      if (chunk->is_tagged_free()) {
+        // Count successive free, non-humongous chunks.
+        if (is_aligned(chunk, size_small)) {
+          assert(num_free_chunks_since_last_small_boundary <= 1,
+              "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_small, size_small);
+          num_free_chunks_since_last_small_boundary = 0;
+        } else if (num_free_chunks_since_last_small_boundary != -1) {
+          num_free_chunks_since_last_small_boundary ++;
+        }
+        if (is_aligned(chunk, size_med)) {
+          assert(num_free_chunks_since_last_med_boundary <= 1,
+              "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_med, size_med);
+          num_free_chunks_since_last_med_boundary = 0;
+        } else if (num_free_chunks_since_last_med_boundary != -1) {
+          num_free_chunks_since_last_med_boundary ++;
+        }
+      } else {
+        // Encountering a non-free chunk, reset counters.
+        num_free_chunks_since_last_med_boundary = -1;
+        num_free_chunks_since_last_small_boundary = -1;
+      }
+    } else {
+      // One cannot merge areas with a humongous chunk in the middle. Reset counters.
+      num_free_chunks_since_last_med_boundary = -1;
+      num_free_chunks_since_last_small_boundary = -1;
+    }
+
+    MetaWord* next = ((MetaWord*)chunk) + chunk->word_size();
+    chunk = (Metachunk*) next;
+  }
+}
+#endif // ASSERT
+
+void VirtualSpaceNode::inc_container_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _container_count++;
+}
+
+void VirtualSpaceNode::dec_container_count() {
+  assert_lock_strong(MetaspaceExpand_lock);
+  _container_count--;
+}
+
+#ifdef ASSERT
+void VirtualSpaceNode::verify_container_count() {
+  assert(_container_count == container_count_slow(),
+      "Inconsistency in container_count _container_count " UINTX_FORMAT
+      " container_count_slow() " UINTX_FORMAT, _container_count, container_count_slow());
+}
+#endif
+
+VirtualSpaceNode::~VirtualSpaceNode() {
+  _rs.release();
+  if (_occupancy_map != NULL) {
+    delete _occupancy_map;
+  }
+#ifdef ASSERT
+  size_t word_size = sizeof(*this) / BytesPerWord;
+  Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1);
+#endif
+}
+
+size_t VirtualSpaceNode::used_words_in_vs() const {
+  return pointer_delta(top(), bottom(), sizeof(MetaWord));
+}
+
+// Space committed in the VirtualSpace
+size_t VirtualSpaceNode::capacity_words_in_vs() const {
+  return pointer_delta(end(), bottom(), sizeof(MetaWord));
+}
+
+size_t VirtualSpaceNode::free_words_in_vs() const {
+  return pointer_delta(end(), top(), sizeof(MetaWord));
+}
+
+// Given an address larger than top(), allocate padding chunks until top is at the given address.
+void VirtualSpaceNode::allocate_padding_chunks_until_top_is_at(MetaWord* target_top) {
+
+  assert(target_top > top(), "Sanity");
+
+  // Padding chunks are added to the freelist.
+  ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class());
+
+  // shorthands
+  const size_t spec_word_size = chunk_manager->specialized_chunk_word_size();
+  const size_t small_word_size = chunk_manager->small_chunk_word_size();
+  const size_t med_word_size = chunk_manager->medium_chunk_word_size();
+
+  while (top() < target_top) {
+
+    // We could make this coding more generic, but right now we only deal with two possible chunk sizes
+    // for padding chunks, so it is not worth it.
+    size_t padding_chunk_word_size = small_word_size;
+    if (is_aligned(top(), small_word_size * sizeof(MetaWord)) == false) {
+      assert_is_aligned(top(), spec_word_size * sizeof(MetaWord)); // Should always hold true.
+      padding_chunk_word_size = spec_word_size;
+    }
+    MetaWord* here = top();
+    assert_is_aligned(here, padding_chunk_word_size * sizeof(MetaWord));
+    inc_top(padding_chunk_word_size);
+
+    // Create new padding chunk.
+    ChunkIndex padding_chunk_type = get_chunk_type_by_size(padding_chunk_word_size, is_class());
+    assert(padding_chunk_type == SpecializedIndex || padding_chunk_type == SmallIndex, "sanity");
+
+    Metachunk* const padding_chunk =
+        ::new (here) Metachunk(padding_chunk_type, is_class(), padding_chunk_word_size, this);
+    assert(padding_chunk == (Metachunk*)here, "Sanity");
+    DEBUG_ONLY(padding_chunk->set_origin(origin_pad);)
+    log_trace(gc, metaspace, freelist)("Created padding chunk in %s at "
+        PTR_FORMAT ", size " SIZE_FORMAT_HEX ".",
+        (is_class() ? "class space " : "metaspace"),
+        p2i(padding_chunk), padding_chunk->word_size() * sizeof(MetaWord));
+
+    // Mark chunk start in occupancy map.
+    occupancy_map()->set_chunk_starts_at_address((MetaWord*)padding_chunk, true);
+
+    // Chunks are born as in-use (see MetaChunk ctor). So, before returning
+    // the padding chunk to its chunk manager, mark it as in use (ChunkManager
+    // will assert that).
+    do_update_in_use_info_for_chunk(padding_chunk, true);
+
+    // Return Chunk to freelist.
+    inc_container_count();
+    chunk_manager->return_single_chunk(padding_chunk);
+    // Please note: at this point, ChunkManager::return_single_chunk()
+    // may already have merged the padding chunk with neighboring chunks, so
+    // it may have vanished at this point. Do not reference the padding
+    // chunk beyond this point.
+  }
+
+  assert(top() == target_top, "Sanity");
+
+} // allocate_padding_chunks_until_top_is_at()
+
+// Allocates the chunk from the virtual space only.
+// This interface is also used internally for debugging.  Not all
+// chunks removed here are necessarily used for allocation.
+Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
+  // Non-humongous chunks are to be allocated aligned to their chunk
+  // size. So, start addresses of medium chunks are aligned to medium
+  // chunk size, those of small chunks to small chunk size and so
+  // forth. This facilitates merging of free chunks and reduces
+  // fragmentation. Chunk sizes are spec < small < medium, with each
+  // larger chunk size being a multiple of the next smaller chunk
+  // size.
+  // Because of this alignment, me may need to create a number of padding
+  // chunks. These chunks are created and added to the freelist.
+
+  // The chunk manager to which we will give our padding chunks.
+  ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class());
+
+  // shorthands
+  const size_t spec_word_size = chunk_manager->specialized_chunk_word_size();
+  const size_t small_word_size = chunk_manager->small_chunk_word_size();
+  const size_t med_word_size = chunk_manager->medium_chunk_word_size();
+
+  assert(chunk_word_size == spec_word_size || chunk_word_size == small_word_size ||
+      chunk_word_size >= med_word_size, "Invalid chunk size requested.");
+
+  // Chunk alignment (in bytes) == chunk size unless humongous.
+  // Humongous chunks are aligned to the smallest chunk size (spec).
+  const size_t required_chunk_alignment = (chunk_word_size > med_word_size ?
+      spec_word_size : chunk_word_size) * sizeof(MetaWord);
+
+  // Do we have enough space to create the requested chunk plus
+  // any padding chunks needed?
+  MetaWord* const next_aligned =
+      static_cast<MetaWord*>(align_up(top(), required_chunk_alignment));
+  if (!is_available((next_aligned - top()) + chunk_word_size)) {
+    return NULL;
+  }
+
+  // Before allocating the requested chunk, allocate padding chunks if necessary.
+  // We only need to do this for small or medium chunks: specialized chunks are the
+  // smallest size, hence always aligned. Homungous chunks are allocated unaligned
+  // (implicitly, also aligned to smallest chunk size).
+  if ((chunk_word_size == med_word_size || chunk_word_size == small_word_size) && next_aligned > top())  {
+    log_trace(gc, metaspace, freelist)("Creating padding chunks in %s between %p and %p...",
+        (is_class() ? "class space " : "metaspace"),
+        top(), next_aligned);
+    allocate_padding_chunks_until_top_is_at(next_aligned);
+    // Now, top should be aligned correctly.
+    assert_is_aligned(top(), required_chunk_alignment);
+  }
+
+  // Now, top should be aligned correctly.
+  assert_is_aligned(top(), required_chunk_alignment);
+
+  // Bottom of the new chunk
+  MetaWord* chunk_limit = top();
+  assert(chunk_limit != NULL, "Not safe to call this method");
+
+  // The virtual spaces are always expanded by the
+  // commit granularity to enforce the following condition.
+  // Without this the is_available check will not work correctly.
+  assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
+      "The committed memory doesn't match the expanded memory.");
+
+  if (!is_available(chunk_word_size)) {
+    LogTarget(Debug, gc, metaspace, freelist) lt;
+    if (lt.is_enabled()) {
+      LogStream ls(lt);
+      ls.print("VirtualSpaceNode::take_from_committed() not available " SIZE_FORMAT " words ", chunk_word_size);
+      // Dump some information about the virtual space that is nearly full
+      print_on(&ls);
+    }
+    return NULL;
+  }
+
+  // Take the space  (bump top on the current virtual space).
+  inc_top(chunk_word_size);
+
+  // Initialize the chunk
+  ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class());
+  Metachunk* result = ::new (chunk_limit) Metachunk(chunk_type, is_class(), chunk_word_size, this);
+  assert(result == (Metachunk*)chunk_limit, "Sanity");
+  occupancy_map()->set_chunk_starts_at_address((MetaWord*)result, true);
+  do_update_in_use_info_for_chunk(result, true);
+
+  inc_container_count();
+
+  if (VerifyMetaspace) {
+    DEBUG_ONLY(chunk_manager->locked_verify());
+    DEBUG_ONLY(this->verify());
+  }
+
+  DEBUG_ONLY(do_verify_chunk(result));
+
+  result->inc_use_count();
+
+  return result;
+}
+
+
+// Expand the virtual space (commit more of the reserved space)
+bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
+  size_t min_bytes = min_words * BytesPerWord;
+  size_t preferred_bytes = preferred_words * BytesPerWord;
+
+  size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
+
+  if (uncommitted < min_bytes) {
+    return false;
+  }
+
+  size_t commit = MIN2(preferred_bytes, uncommitted);
+  bool result = virtual_space()->expand_by(commit, false);
+
+  if (result) {
+    log_trace(gc, metaspace, freelist)("Expanded %s virtual space list node by " SIZE_FORMAT " words.",
+        (is_class() ? "class" : "non-class"), commit);
+    DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_committed_space_expanded));
+  } else {
+    log_trace(gc, metaspace, freelist)("Failed to expand %s virtual space list node by " SIZE_FORMAT " words.",
+        (is_class() ? "class" : "non-class"), commit);
+  }
+
+  assert(result, "Failed to commit memory");
+
+  return result;
+}
+
+Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
+  assert_lock_strong(MetaspaceExpand_lock);
+  Metachunk* result = take_from_committed(chunk_word_size);
+  return result;
+}
+
+bool VirtualSpaceNode::initialize() {
+
+  if (!_rs.is_reserved()) {
+    return false;
+  }
+
+  // These are necessary restriction to make sure that the virtual space always
+  // grows in steps of Metaspace::commit_alignment(). If both base and size are
+  // aligned only the middle alignment of the VirtualSpace is used.
+  assert_is_aligned(_rs.base(), Metaspace::commit_alignment());
+  assert_is_aligned(_rs.size(), Metaspace::commit_alignment());
+
+  // ReservedSpaces marked as special will have the entire memory
+  // pre-committed. Setting a committed size will make sure that
+  // committed_size and actual_committed_size agrees.
+  size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
+
+  bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
+      Metaspace::commit_alignment());
+  if (result) {
+    assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
+        "Checking that the pre-committed memory was registered by the VirtualSpace");
+
+    set_top((MetaWord*)virtual_space()->low());
+    set_reserved(MemRegion((HeapWord*)_rs.base(),
+        (HeapWord*)(_rs.base() + _rs.size())));
+
+    assert(reserved()->start() == (HeapWord*) _rs.base(),
+        "Reserved start was not set properly " PTR_FORMAT
+        " != " PTR_FORMAT, p2i(reserved()->start()), p2i(_rs.base()));
+    assert(reserved()->word_size() == _rs.size() / BytesPerWord,
+        "Reserved size was not set properly " SIZE_FORMAT
+        " != " SIZE_FORMAT, reserved()->word_size(),
+        _rs.size() / BytesPerWord);
+  }
+
+  // Initialize Occupancy Map.
+  const size_t smallest_chunk_size = is_class() ? ClassSpecializedChunk : SpecializedChunk;
+  _occupancy_map = new OccupancyMap(bottom(), reserved_words(), smallest_chunk_size);
+
+  return result;
+}
+
+void VirtualSpaceNode::print_on(outputStream* st, size_t scale) const {
+  size_t used_words = used_words_in_vs();
+  size_t commit_words = committed_words();
+  size_t res_words = reserved_words();
+  VirtualSpace* vs = virtual_space();
+
+  st->print("node @" PTR_FORMAT ": ", p2i(this));
+  st->print("reserved=");
+  print_scaled_words(st, res_words, scale);
+  st->print(", committed=");
+  print_scaled_words_and_percentage(st, commit_words, res_words, scale);
+  st->print(", used=");
+  print_scaled_words_and_percentage(st, used_words, res_words, scale);
+  st->cr();
+  st->print("   [" PTR_FORMAT ", " PTR_FORMAT ", "
+      PTR_FORMAT ", " PTR_FORMAT ")",
+      p2i(bottom()), p2i(top()), p2i(end()),
+      p2i(vs->high_boundary()));
+}
+
+#ifdef ASSERT
+void VirtualSpaceNode::mangle() {
+  size_t word_size = capacity_words_in_vs();
+  Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
+}
+#endif // ASSERT
+
+void VirtualSpaceNode::retire(ChunkManager* chunk_manager) {
+  DEBUG_ONLY(verify_container_count();)
+  assert(this->is_class() == chunk_manager->is_class(), "Wrong ChunkManager?");
+  for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) {
+    ChunkIndex index = (ChunkIndex)i;
+    size_t chunk_size = chunk_manager->size_by_index(index);
+
+    while (free_words_in_vs() >= chunk_size) {
+      Metachunk* chunk = get_chunk_vs(chunk_size);
+      // Chunk will be allocated aligned, so allocation may require
+      // additional padding chunks. That may cause above allocation to
+      // fail. Just ignore the failed allocation and continue with the
+      // next smaller chunk size. As the VirtualSpaceNode comitted
+      // size should be a multiple of the smallest chunk size, we
+      // should always be able to fill the VirtualSpace completely.
+      if (chunk == NULL) {
+        break;
+      }
+      chunk_manager->return_single_chunk(chunk);
+    }
+    DEBUG_ONLY(verify_container_count();)
+  }
+  assert(free_words_in_vs() == 0, "should be empty now");
+}
+
+} // namespace metaspace
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/virtualSpaceNode.hpp	Mon May 21 11:33:59 2018 +0200
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
+#define SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
+
+#include "memory/virtualspace.hpp"
+#include "memory/memRegion.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+
+namespace metaspace {
+
+class Metachunk;
+class ChunkManager;
+class OccupancyMap;
+
+// A VirtualSpaceList node.
+class VirtualSpaceNode : public CHeapObj<mtClass> {
+  friend class VirtualSpaceList;
+
+  // Link to next VirtualSpaceNode
+  VirtualSpaceNode* _next;
+
+  // Whether this node is contained in class or metaspace.
+  const bool _is_class;
+
+  // total in the VirtualSpace
+  MemRegion _reserved;
+  ReservedSpace _rs;
+  VirtualSpace _virtual_space;
+  MetaWord* _top;
+  // count of chunks contained in this VirtualSpace
+  uintx _container_count;
+
+  OccupancyMap* _occupancy_map;
+
+  // Convenience functions to access the _virtual_space
+  char* low()  const { return virtual_space()->low(); }
+  char* high() const { return virtual_space()->high(); }
+
+  // The first Metachunk will be allocated at the bottom of the
+  // VirtualSpace
+  Metachunk* first_chunk() { return (Metachunk*) bottom(); }
+
+  // Committed but unused space in the virtual space
+  size_t free_words_in_vs() const;
+
+  // True if this node belongs to class metaspace.
+  bool is_class() const { return _is_class; }
+
+  // Helper function for take_from_committed: allocate padding chunks
+  // until top is at the given address.
+  void allocate_padding_chunks_until_top_is_at(MetaWord* target_top);
+
+ public:
+
+  VirtualSpaceNode(bool is_class, size_t byte_size);
+  VirtualSpaceNode(bool is_class, ReservedSpace rs) :
+    _is_class(is_class), _top(NULL), _next(NULL), _rs(rs), _container_count(0), _occupancy_map(NULL) {}
+  ~VirtualSpaceNode();
+
+  // Convenience functions for logical bottom and end
+  MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
+  MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
+
+  const OccupancyMap* occupancy_map() const { return _occupancy_map; }
+  OccupancyMap* occupancy_map() { return _occupancy_map; }
+
+  bool contains(const void* ptr) { return ptr >= low() && ptr < high(); }
+
+  size_t reserved_words() const  { return _virtual_space.reserved_size() / BytesPerWord; }
+  size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; }
+
+  bool is_pre_committed() const { return _virtual_space.special(); }
+
+  // address of next available space in _virtual_space;
+  // Accessors
+  VirtualSpaceNode* next() { return _next; }
+  void set_next(VirtualSpaceNode* v) { _next = v; }
+
+  void set_reserved(MemRegion const v) { _reserved = v; }
+  void set_top(MetaWord* v) { _top = v; }
+
+  // Accessors
+  MemRegion* reserved() { return &_reserved; }
+  VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
+
+  // Returns true if "word_size" is available in the VirtualSpace
+  bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); }
+
+  MetaWord* top() const { return _top; }
+  void inc_top(size_t word_size) { _top += word_size; }
+
+  uintx container_count() { return _container_count; }
+  void inc_container_count();
+  void dec_container_count();
+#ifdef ASSERT
+  uintx container_count_slow();
+  void verify_container_count();
+#endif
+
+  // used and capacity in this single entry in the list
+  size_t used_words_in_vs() const;
+  size_t capacity_words_in_vs() const;
+
+  bool initialize();
+
+  // get space from the virtual space
+  Metachunk* take_from_committed(size_t chunk_word_size);
+
+  // Allocate a chunk from the virtual space and return it.
+  Metachunk* get_chunk_vs(size_t chunk_word_size);
+
+  // Expands/shrinks the committed space in a virtual space.  Delegates
+  // to Virtualspace
+  bool expand_by(size_t min_words, size_t preferred_words);
+
+  // In preparation for deleting this node, remove all the chunks
+  // in the node from any freelist.
+  void purge(ChunkManager* chunk_manager);
+
+  // If an allocation doesn't fit in the current node a new node is created.
+  // Allocate chunks out of the remaining committed space in this node
+  // to avoid wasting that memory.
+  // This always adds up because all the chunk sizes are multiples of
+  // the smallest chunk size.
+  void retire(ChunkManager* chunk_manager);
+
+  void print_on(outputStream* st) const                 { print_on(st, K); }
+  void print_on(outputStream* st, size_t scale) const;
+  void print_map(outputStream* st, bool is_class) const;
+
+  // Debug support
+  DEBUG_ONLY(void mangle();)
+  // Verify counters, all chunks in this list node and the occupancy map.
+  DEBUG_ONLY(void verify();)
+  // Verify that all free chunks in this node are ideally merged
+  // (there not should be multiple small chunks where a large chunk could exist.)
+  DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();)
+
+};
+
+} // namespace metaspace
+
+#endif /* SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP */
--- a/src/hotspot/share/runtime/vmStructs.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/src/hotspot/share/runtime/vmStructs.cpp	Mon May 21 11:33:59 2018 +0200
@@ -51,7 +51,7 @@
 #include "memory/allocation.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/heap.hpp"
-#include "memory/metachunk.hpp"
+#include "memory/metaspace/metablock.hpp"
 #include "memory/padded.hpp"
 #include "memory/referenceType.hpp"
 #include "memory/universe.hpp"
--- a/test/hotspot/gtest/memory/test_chunkManager.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/test/hotspot/gtest/memory/test_chunkManager.cpp	Mon May 21 11:33:59 2018 +0200
@@ -22,18 +22,47 @@
  */
 
 #include "precompiled.hpp"
+#include "memory/metaspace/chunkManager.hpp"
+#include "memory/metaspace/metaspaceCommon.hpp"
 
 // The test function is only available in debug builds
 #ifdef ASSERT
 
 #include "unittest.hpp"
 
-void ChunkManager_test_list_index();
+using namespace metaspace;
 
 TEST(ChunkManager, list_index) {
-  // The ChunkManager is only available in metaspace.cpp,
-  // so the test code is located in that file.
-  ChunkManager_test_list_index();
+
+  // Test previous bug where a query for a humongous class metachunk,
+  // incorrectly matched the non-class medium metachunk size.
+  {
+    ChunkManager manager(true);
+
+    ASSERT_TRUE(MediumChunk > ClassMediumChunk) << "Precondition for test";
+
+    ChunkIndex index = manager.list_index(MediumChunk);
+
+    ASSERT_TRUE(index == HumongousIndex) <<
+        "Requested size is larger than ClassMediumChunk,"
+        " so should return HumongousIndex. Got index: " << index;
+  }
+
+  // Check the specified sizes as well.
+  {
+    ChunkManager manager(true);
+    ASSERT_TRUE(manager.list_index(ClassSpecializedChunk) == SpecializedIndex);
+    ASSERT_TRUE(manager.list_index(ClassSmallChunk) == SmallIndex);
+    ASSERT_TRUE(manager.list_index(ClassMediumChunk) == MediumIndex);
+    ASSERT_TRUE(manager.list_index(ClassMediumChunk + ClassSpecializedChunk) == HumongousIndex);
+  }
+  {
+    ChunkManager manager(false);
+    ASSERT_TRUE(manager.list_index(SpecializedChunk) == SpecializedIndex);
+    ASSERT_TRUE(manager.list_index(SmallChunk) == SmallIndex);
+    ASSERT_TRUE(manager.list_index(MediumChunk) == MediumIndex);
+    ASSERT_TRUE(manager.list_index(MediumChunk + SpecializedChunk) == HumongousIndex);
+  }
 
 }
 
--- a/test/hotspot/gtest/memory/test_metachunk.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/test/hotspot/gtest/memory/test_metachunk.cpp	Mon May 21 11:33:59 2018 +0200
@@ -23,12 +23,14 @@
 
 #include "precompiled.hpp"
 #include "memory/allocation.hpp"
-#include "memory/metachunk.hpp"
+#include "memory/metaspace/metachunk.hpp"
 #include "unittest.hpp"
 #include "utilities/align.hpp"
 #include "utilities/copy.hpp"
 #include "utilities/debug.hpp"
 
+using namespace metaspace;
+
 class MetachunkTest {
  public:
   static MetaWord* initial_top(Metachunk* metachunk) {
--- a/test/hotspot/gtest/memory/test_spaceManager.cpp	Sun May 20 22:10:45 2018 +0200
+++ b/test/hotspot/gtest/memory/test_spaceManager.cpp	Mon May 21 11:33:59 2018 +0200
@@ -22,18 +22,53 @@
  */
 
 #include "precompiled.hpp"
+#include "memory/metaspace/spaceManager.hpp"
+
+using metaspace::SpaceManager;
 
 // The test function is only available in debug builds
 #ifdef ASSERT
 
 #include "unittest.hpp"
 
-void SpaceManager_test_adjust_initial_chunk_size();
+
+static void test_adjust_initial_chunk_size(bool is_class) {
+  const size_t smallest = SpaceManager::smallest_chunk_size(is_class);
+  const size_t normal   = SpaceManager::small_chunk_size(is_class);
+  const size_t medium   = SpaceManager::medium_chunk_size(is_class);
+
+#define do_test(value, expected, is_class_value)                                 \
+    do {                                                                         \
+      size_t v = value;                                                          \
+      size_t e = expected;                                                       \
+      assert(SpaceManager::adjust_initial_chunk_size(v, (is_class_value)) == e,  \
+             "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT, e, v);               \
+    } while (0)
+
+    // Smallest (specialized)
+    do_test(1,            smallest, is_class);
+    do_test(smallest - 1, smallest, is_class);
+    do_test(smallest,     smallest, is_class);
+
+    // Small
+    do_test(smallest + 1, normal, is_class);
+    do_test(normal - 1,   normal, is_class);
+    do_test(normal,       normal, is_class);
+
+    // Medium
+    do_test(normal + 1, medium, is_class);
+    do_test(medium - 1, medium, is_class);
+    do_test(medium,     medium, is_class);
+
+    // Humongous
+    do_test(medium + 1, medium + 1, is_class);
+
+#undef test_adjust_initial_chunk_size
+}
 
 TEST(SpaceManager, adjust_initial_chunk_size) {
-  // The SpaceManager is only available in metaspace.cpp,
-  // so the test code is located in that file.
-  SpaceManager_test_adjust_initial_chunk_size();
+  test_adjust_initial_chunk_size(true);
+  test_adjust_initial_chunk_size(false);
 }
 
 #endif // ASSERT