changeset 3761:685df3c6f84b

7045397: NPG: Add freelists to class loader arenas. Reviewed-by: coleenp, stefank, jprovino, ohair
author jmasa
date Tue, 18 Sep 2012 23:35:42 -0700
parents d0e7716b179e
children 476718ea6759
files make/excludeSrc.make src/share/vm/gc_implementation/concurrentMarkSweep/adaptiveFreeList.cpp src/share/vm/gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp src/share/vm/gc_implementation/shared/vmGCOperations.hpp src/share/vm/memory/binaryTreeDictionary.cpp src/share/vm/memory/binaryTreeDictionary.hpp src/share/vm/memory/freeBlockDictionary.cpp src/share/vm/memory/freeBlockDictionary.hpp src/share/vm/memory/freeList.cpp src/share/vm/memory/freeList.hpp src/share/vm/memory/metablock.hpp src/share/vm/memory/metachunk.hpp src/share/vm/memory/metaspace.cpp src/share/vm/memory/metaspace.hpp src/share/vm/runtime/vmStructs.cpp
diffstat 20 files changed, 1558 insertions(+), 1234 deletions(-) [+]
line wrap: on
line diff
--- a/make/excludeSrc.make	Fri Oct 19 11:26:17 2012 -0700
+++ b/make/excludeSrc.make	Tue Sep 18 23:35:42 2012 -0700
@@ -79,10 +79,10 @@
       CXXFLAGS += -DSERIALGC
       CFLAGS += -DSERIALGC
       Src_Files_EXCLUDE += \
-	binaryTreeDictionary.cpp cmsAdaptiveSizePolicy.cpp cmsCollectorPolicy.cpp \
+	cmsAdaptiveSizePolicy.cpp cmsCollectorPolicy.cpp \
 	cmsGCAdaptivePolicyCounters.cpp cmsLockVerifier.cpp cmsPermGen.cpp compactibleFreeListSpace.cpp \
-	concurrentMarkSweepGeneration.cpp concurrentMarkSweepThread.cpp freeBlockDictionary.cpp \
-	freeChunk.cpp freeList.cpp promotionInfo.cpp vmCMSOperations.cpp collectionSetChooser.cpp \
+	concurrentMarkSweepGeneration.cpp concurrentMarkSweepThread.cpp \
+	freeChunk.cpp adaptiveFreeList.cpp promotionInfo.cpp vmCMSOperations.cpp collectionSetChooser.cpp \
 	concurrentG1Refine.cpp concurrentG1RefineThread.cpp concurrentMark.cpp concurrentMarkThread.cpp \
 	dirtyCardQueue.cpp g1AllocRegion.cpp g1BlockOffsetTable.cpp g1CollectedHeap.cpp g1GCPhaseTimes.cpp \
 	g1CollectorPolicy.cpp g1ErgoVerbose.cpp g1_globals.cpp g1HRPrinter.cpp g1MarkSweep.cpp \
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/adaptiveFreeList.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2012, 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 "gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp"
+#include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
+#include "memory/freeBlockDictionary.hpp"
+#include "memory/sharedHeap.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/mutex.hpp"
+#include "runtime/vmThread.hpp"
+
+template <>
+void AdaptiveFreeList<FreeChunk>::print_on(outputStream* st, const char* c) const {
+  if (c != NULL) {
+    st->print("%16s", c);
+  } else {
+    st->print(SIZE_FORMAT_W(16), size());
+  }
+  st->print("\t"
+           SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t"
+           SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\n",
+           bfr_surp(),             surplus(),             desired(),             prev_sweep(),           before_sweep(),
+           count(),               coal_births(),          coal_deaths(),          split_births(),         split_deaths());
+}
+
+template <class Chunk>
+AdaptiveFreeList<Chunk>::AdaptiveFreeList() : FreeList<Chunk>(), _hint(0) {
+  init_statistics();
+}
+
+template <class Chunk>
+AdaptiveFreeList<Chunk>::AdaptiveFreeList(Chunk* fc) : FreeList<Chunk>(fc), _hint(0) {
+  init_statistics();
+#ifndef PRODUCT
+  _allocation_stats.set_returned_bytes(size() * HeapWordSize);
+#endif
+}
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::initialize() {
+  FreeList<Chunk>::initialize();
+  set_hint(0);
+  init_statistics(true /* split_birth */);
+}
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::reset(size_t hint) {
+  FreeList<Chunk>::reset();
+  set_hint(hint);
+}
+
+#ifndef PRODUCT
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::assert_proper_lock_protection_work() const {
+  assert(protecting_lock() != NULL, "Don't call this directly");
+  assert(ParallelGCThreads > 0, "Don't call this directly");
+  Thread* thr = Thread::current();
+  if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) {
+    // assert that we are holding the freelist lock
+  } else if (thr->is_GC_task_thread()) {
+    assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED");
+  } else if (thr->is_Java_thread()) {
+    assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing");
+  } else {
+    ShouldNotReachHere();  // unaccounted thread type?
+  }
+}
+#endif
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::init_statistics(bool split_birth) {
+  _allocation_stats.initialize(split_birth);
+}
+
+template <class Chunk>
+size_t AdaptiveFreeList<Chunk>::get_better_size() {
+
+  // A candidate chunk has been found.  If it is already under
+  // populated and there is a hinT, REturn the hint().  Else
+  // return the size of this chunk.
+  if (surplus() <= 0) {
+    if (hint() != 0) {
+      return hint();
+    } else {
+      return size();
+    }
+  } else {
+    // This list has a surplus so use it.
+    return size();
+  }
+}
+
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk) {
+  assert_proper_lock_protection();
+  return_chunk_at_head(chunk, true);
+}
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk, bool record_return) {
+  FreeList<Chunk>::return_chunk_at_head(chunk, record_return);
+#ifdef ASSERT
+  if (record_return) {
+    increment_returned_bytes_by(size()*HeapWordSize);
+  }
+#endif
+}
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk) {
+  return_chunk_at_tail(chunk, true);
+}
+
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk, bool record_return) {
+  FreeList<Chunk>::return_chunk_at_tail(chunk, record_return);
+#ifdef ASSERT
+  if (record_return) {
+    increment_returned_bytes_by(size()*HeapWordSize);
+  }
+#endif
+}
+
+#ifndef PRODUCT
+template <class Chunk>
+void AdaptiveFreeList<Chunk>::verify_stats() const {
+  // The +1 of the LH comparand is to allow some "looseness" in
+  // checking: we usually call this interface when adding a block
+  // and we'll subsequently update the stats; we cannot update the
+  // stats beforehand because in the case of the large-block BT
+  // dictionary for example, this might be the first block and
+  // in that case there would be no place that we could record
+  // the stats (which are kept in the block itself).
+  assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births()
+          + _allocation_stats.coal_births() + 1)   // Total Production Stock + 1
+         >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths()
+             + (ssize_t)count()),                // Total Current Stock + depletion
+         err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
+                 " violates Conservation Principle: "
+                 "prev_sweep(" SIZE_FORMAT ")"
+                 " + split_births(" SIZE_FORMAT ")"
+                 " + coal_births(" SIZE_FORMAT ") + 1 >= "
+                 " split_deaths(" SIZE_FORMAT ")"
+                 " coal_deaths(" SIZE_FORMAT ")"
+                 " + count(" SSIZE_FORMAT ")",
+                 this, size(), _allocation_stats.prev_sweep(), _allocation_stats.split_births(),
+                 _allocation_stats.split_births(), _allocation_stats.split_deaths(),
+                 _allocation_stats.coal_deaths(), count()));
+}
+#endif
+
+// Needs to be after the definitions have been seen.
+template class AdaptiveFreeList<FreeChunk>;
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 2001, 2010, 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_ADAPTIVEFREELIST_HPP
+#define SHARE_VM_MEMORY_ADAPTIVEFREELIST_HPP
+
+#include "memory/freeList.hpp"
+#include "gc_implementation/shared/allocationStats.hpp"
+
+class CompactibleFreeListSpace;
+
+// A class for maintaining a free list of Chunk's.  The FreeList
+// maintains a the structure of the list (head, tail, etc.) plus
+// statistics for allocations from the list.  The links between items
+// are not part of FreeList.  The statistics are
+// used to make decisions about coalescing Chunk's when they
+// are swept during collection.
+//
+// See the corresponding .cpp file for a description of the specifics
+// for that implementation.
+
+class Mutex;
+
+template <class Chunk>
+class AdaptiveFreeList : public FreeList<Chunk> {
+  friend class CompactibleFreeListSpace;
+  friend class VMStructs;
+  // friend class PrintTreeCensusClosure<Chunk, FreeList_t>;
+
+  size_t        _hint;          // next larger size list with a positive surplus
+
+  AllocationStats _allocation_stats; // allocation-related statistics
+
+ public:
+
+  AdaptiveFreeList();
+  AdaptiveFreeList(Chunk* fc);
+
+  using FreeList<Chunk>::assert_proper_lock_protection;
+#ifdef ASSERT
+  using FreeList<Chunk>::protecting_lock;
+#endif
+  using FreeList<Chunk>::count;
+  using FreeList<Chunk>::size;
+  using FreeList<Chunk>::verify_chunk_in_free_list;
+  using FreeList<Chunk>::getFirstNChunksFromList;
+  using FreeList<Chunk>::print_on;
+  void return_chunk_at_head(Chunk* fc, bool record_return);
+  void return_chunk_at_head(Chunk* fc);
+  void return_chunk_at_tail(Chunk* fc, bool record_return);
+  void return_chunk_at_tail(Chunk* fc);
+  using FreeList<Chunk>::return_chunk_at_tail;
+  using FreeList<Chunk>::remove_chunk;
+  using FreeList<Chunk>::prepend;
+  using FreeList<Chunk>::print_labels_on;
+  using FreeList<Chunk>::get_chunk_at_head;
+
+  // Initialize.
+  void initialize();
+
+  // Reset the head, tail, hint, and count of a free list.
+  void reset(size_t hint);
+
+  void assert_proper_lock_protection_work() const PRODUCT_RETURN;
+
+  void print_on(outputStream* st, const char* c = NULL) const;
+
+  size_t hint() const {
+    return _hint;
+  }
+  void set_hint(size_t v) {
+    assert_proper_lock_protection();
+    assert(v == 0 || size() < v, "Bad hint");
+    _hint = v;
+  }
+
+  size_t get_better_size();
+
+  // Accessors for statistics
+  void init_statistics(bool split_birth = false);
+
+  AllocationStats* allocation_stats() {
+    assert_proper_lock_protection();
+    return &_allocation_stats;
+  }
+
+  ssize_t desired() const {
+    return _allocation_stats.desired();
+  }
+  void set_desired(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_desired(v);
+  }
+  void compute_desired(float inter_sweep_current,
+                       float inter_sweep_estimate,
+                       float intra_sweep_estimate) {
+    assert_proper_lock_protection();
+    _allocation_stats.compute_desired(count(),
+                                      inter_sweep_current,
+                                      inter_sweep_estimate,
+                                      intra_sweep_estimate);
+  }
+  ssize_t coal_desired() const {
+    return _allocation_stats.coal_desired();
+  }
+  void set_coal_desired(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_coal_desired(v);
+  }
+
+  ssize_t surplus() const {
+    return _allocation_stats.surplus();
+  }
+  void set_surplus(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_surplus(v);
+  }
+  void increment_surplus() {
+    assert_proper_lock_protection();
+    _allocation_stats.increment_surplus();
+  }
+  void decrement_surplus() {
+    assert_proper_lock_protection();
+    _allocation_stats.decrement_surplus();
+  }
+
+  ssize_t bfr_surp() const {
+    return _allocation_stats.bfr_surp();
+  }
+  void set_bfr_surp(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_bfr_surp(v);
+  }
+  ssize_t prev_sweep() const {
+    return _allocation_stats.prev_sweep();
+  }
+  void set_prev_sweep(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_prev_sweep(v);
+  }
+  ssize_t before_sweep() const {
+    return _allocation_stats.before_sweep();
+  }
+  void set_before_sweep(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_before_sweep(v);
+  }
+
+  ssize_t coal_births() const {
+    return _allocation_stats.coal_births();
+  }
+  void set_coal_births(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_coal_births(v);
+  }
+  void increment_coal_births() {
+    assert_proper_lock_protection();
+    _allocation_stats.increment_coal_births();
+  }
+
+  ssize_t coal_deaths() const {
+    return _allocation_stats.coal_deaths();
+  }
+  void set_coal_deaths(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_coal_deaths(v);
+  }
+  void increment_coal_deaths() {
+    assert_proper_lock_protection();
+    _allocation_stats.increment_coal_deaths();
+  }
+
+  ssize_t split_births() const {
+    return _allocation_stats.split_births();
+  }
+  void set_split_births(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_split_births(v);
+  }
+  void increment_split_births() {
+    assert_proper_lock_protection();
+    _allocation_stats.increment_split_births();
+  }
+
+  ssize_t split_deaths() const {
+    return _allocation_stats.split_deaths();
+  }
+  void set_split_deaths(ssize_t v) {
+    assert_proper_lock_protection();
+    _allocation_stats.set_split_deaths(v);
+  }
+  void increment_split_deaths() {
+    assert_proper_lock_protection();
+    _allocation_stats.increment_split_deaths();
+  }
+
+#ifndef PRODUCT
+  // For debugging.  The "_returned_bytes" in all the lists are summed
+  // and compared with the total number of bytes swept during a
+  // collection.
+  size_t returned_bytes() const { return _allocation_stats.returned_bytes(); }
+  void set_returned_bytes(size_t v) { _allocation_stats.set_returned_bytes(v); }
+  void increment_returned_bytes_by(size_t v) {
+    _allocation_stats.set_returned_bytes(_allocation_stats.returned_bytes() + v);
+  }
+  // Stats verification
+  void verify_stats() const;
+#endif  // NOT PRODUCT
+};
+
+#endif // SHARE_VM_MEMORY_ADAPTIVEFREELIST_HPP
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -91,7 +91,7 @@
   _collector(NULL)
 {
   assert(sizeof(FreeChunk) / BytesPerWord <= MinChunkSize,
-    "FreeChunk is larger than expected");
+         "FreeChunk is larger than expected");
   _bt.set_space(this);
   initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle);
   // We have all of "mr", all of which we place in the dictionary
@@ -101,14 +101,14 @@
   // implementation, namely, the simple binary tree (splaying
   // temporarily disabled).
   switch (dictionaryChoice) {
+    case FreeBlockDictionary<FreeChunk>::dictionaryBinaryTree:
+      _dictionary = new BinaryTreeDictionary<FreeChunk, AdaptiveFreeList>(mr);
+      break;
     case FreeBlockDictionary<FreeChunk>::dictionarySplayTree:
     case FreeBlockDictionary<FreeChunk>::dictionarySkipList:
     default:
       warning("dictionaryChoice: selected option not understood; using"
               " default BinaryTreeDictionary implementation instead.");
-    case FreeBlockDictionary<FreeChunk>::dictionaryBinaryTree:
-      _dictionary = new BinaryTreeDictionary<FreeChunk>(mr, use_adaptive_freelists);
-      break;
   }
   assert(_dictionary != NULL, "CMS dictionary initialization");
   // The indexed free lists are initially all empty and are lazily
@@ -453,7 +453,7 @@
   reportIndexedFreeListStatistics();
   gclog_or_tty->print_cr("Layout of Indexed Freelists");
   gclog_or_tty->print_cr("---------------------------");
-  FreeList<FreeChunk>::print_labels_on(st, "size");
+  AdaptiveFreeList<FreeChunk>::print_labels_on(st, "size");
   for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
     _indexedFreeList[i].print_on(gclog_or_tty);
     for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL;
@@ -1319,7 +1319,7 @@
   size_t currSize = numWords + MinChunkSize;
   assert(currSize % MinObjAlignment == 0, "currSize should be aligned");
   for (i = currSize; i < IndexSetSize; i += IndexSetStride) {
-    FreeList<FreeChunk>* fl = &_indexedFreeList[i];
+    AdaptiveFreeList<FreeChunk>* fl = &_indexedFreeList[i];
     if (fl->head()) {
       ret = getFromListGreater(fl, numWords);
       assert(ret == NULL || ret->is_free(), "Should be returning a free chunk");
@@ -1702,7 +1702,9 @@
   _dictionary->return_chunk(chunk);
 #ifndef PRODUCT
   if (CMSCollector::abstract_state() != CMSCollector::Sweeping) {
-    TreeChunk<FreeChunk>::as_TreeChunk(chunk)->list()->verify_stats();
+    TreeChunk<FreeChunk, AdaptiveFreeList>* tc = TreeChunk<FreeChunk, AdaptiveFreeList>::as_TreeChunk(chunk);
+    TreeList<FreeChunk, AdaptiveFreeList>* tl = tc->list();
+    tl->verify_stats();
   }
 #endif // PRODUCT
 }
@@ -1745,7 +1747,7 @@
   {
     MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag);
     ec = dictionary()->find_largest_dict();  // get largest block
-    if (ec != NULL && ec->end() == chunk) {
+    if (ec != NULL && ec->end() == (uintptr_t*) chunk) {
       // It's a coterminal block - we can coalesce.
       size_t old_size = ec->size();
       coalDeath(old_size);
@@ -1850,11 +1852,11 @@
      the excess is >= MIN_CHUNK. */
   size_t start = align_object_size(numWords + MinChunkSize);
   if (start < IndexSetSize) {
-    FreeList<FreeChunk>* it   = _indexedFreeList;
+    AdaptiveFreeList<FreeChunk>* it   = _indexedFreeList;
     size_t    hint = _indexedFreeList[start].hint();
     while (hint < IndexSetSize) {
       assert(hint % MinObjAlignment == 0, "hint should be aligned");
-      FreeList<FreeChunk> *fl = &_indexedFreeList[hint];
+      AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[hint];
       if (fl->surplus() > 0 && fl->head() != NULL) {
         // Found a list with surplus, reset original hint
         // and split out a free chunk which is returned.
@@ -1873,7 +1875,7 @@
 }
 
 /* Requires fl->size >= numWords + MinChunkSize */
-FreeChunk* CompactibleFreeListSpace::getFromListGreater(FreeList<FreeChunk>* fl,
+FreeChunk* CompactibleFreeListSpace::getFromListGreater(AdaptiveFreeList<FreeChunk>* fl,
   size_t numWords) {
   FreeChunk *curr = fl->head();
   size_t oldNumWords = curr->size();
@@ -2155,7 +2157,7 @@
   assert_locked();
   size_t i;
   for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
-    FreeList<FreeChunk>* fl = &_indexedFreeList[i];
+    AdaptiveFreeList<FreeChunk>* fl    = &_indexedFreeList[i];
     if (PrintFLSStatistics > 1) {
       gclog_or_tty->print("size[%d] : ", i);
     }
@@ -2174,7 +2176,7 @@
   assert_locked();
   size_t i;
   for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
-    FreeList<FreeChunk> *fl = &_indexedFreeList[i];
+    AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[i];
     fl->set_surplus(fl->count() -
                     (ssize_t)((double)fl->desired() * CMSSmallSplitSurplusPercent));
   }
@@ -2185,7 +2187,7 @@
   size_t i;
   size_t h = IndexSetSize;
   for (i = IndexSetSize - 1; i != 0; i -= IndexSetStride) {
-    FreeList<FreeChunk> *fl = &_indexedFreeList[i];
+    AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[i];
     fl->set_hint(h);
     if (fl->surplus() > 0) {
       h = i;
@@ -2197,7 +2199,7 @@
   assert_locked();
   size_t i;
   for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
-    FreeList<FreeChunk> *fl = &_indexedFreeList[i];
+    AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[i];
     fl->set_prev_sweep(fl->count());
     fl->set_coal_births(0);
     fl->set_coal_deaths(0);
@@ -2224,7 +2226,7 @@
 
 bool CompactibleFreeListSpace::coalOverPopulated(size_t size) {
   if (size < SmallForDictionary) {
-    FreeList<FreeChunk> *fl = &_indexedFreeList[size];
+    AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[size];
     return (fl->coal_desired() < 0) ||
            ((int)fl->count() > fl->coal_desired());
   } else {
@@ -2234,14 +2236,14 @@
 
 void CompactibleFreeListSpace::smallCoalBirth(size_t size) {
   assert(size < SmallForDictionary, "Size too large for indexed list");
-  FreeList<FreeChunk> *fl = &_indexedFreeList[size];
+  AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[size];
   fl->increment_coal_births();
   fl->increment_surplus();
 }
 
 void CompactibleFreeListSpace::smallCoalDeath(size_t size) {
   assert(size < SmallForDictionary, "Size too large for indexed list");
-  FreeList<FreeChunk> *fl = &_indexedFreeList[size];
+  AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[size];
   fl->increment_coal_deaths();
   fl->decrement_surplus();
 }
@@ -2250,7 +2252,7 @@
   if (size  < SmallForDictionary) {
     smallCoalBirth(size);
   } else {
-    dictionary()->dict_census_udpate(size,
+    dictionary()->dict_census_update(size,
                                    false /* split */,
                                    true /* birth */);
   }
@@ -2260,7 +2262,7 @@
   if(size  < SmallForDictionary) {
     smallCoalDeath(size);
   } else {
-    dictionary()->dict_census_udpate(size,
+    dictionary()->dict_census_update(size,
                                    false /* split */,
                                    false /* birth */);
   }
@@ -2268,14 +2270,14 @@
 
 void CompactibleFreeListSpace::smallSplitBirth(size_t size) {
   assert(size < SmallForDictionary, "Size too large for indexed list");
-  FreeList<FreeChunk> *fl = &_indexedFreeList[size];
+  AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[size];
   fl->increment_split_births();
   fl->increment_surplus();
 }
 
 void CompactibleFreeListSpace::smallSplitDeath(size_t size) {
   assert(size < SmallForDictionary, "Size too large for indexed list");
-  FreeList<FreeChunk> *fl = &_indexedFreeList[size];
+  AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[size];
   fl->increment_split_deaths();
   fl->decrement_surplus();
 }
@@ -2284,7 +2286,7 @@
   if (size  < SmallForDictionary) {
     smallSplitBirth(size);
   } else {
-    dictionary()->dict_census_udpate(size,
+    dictionary()->dict_census_update(size,
                                    true /* split */,
                                    true /* birth */);
   }
@@ -2294,7 +2296,7 @@
   if (size  < SmallForDictionary) {
     smallSplitDeath(size);
   } else {
-    dictionary()->dict_census_udpate(size,
+    dictionary()->dict_census_update(size,
                                    true /* split */,
                                    false /* birth */);
   }
@@ -2517,10 +2519,10 @@
 
 #ifndef PRODUCT
 void CompactibleFreeListSpace::check_free_list_consistency() const {
-  assert(_dictionary->min_size() <= IndexSetSize,
+  assert((TreeChunk<FreeChunk, AdaptiveFreeList>::min_size() <= IndexSetSize),
     "Some sizes can't be allocated without recourse to"
     " linear allocation buffers");
-  assert(BinaryTreeDictionary<FreeChunk>::min_tree_chunk_size*HeapWordSize == sizeof(TreeChunk<FreeChunk>),
+  assert((TreeChunk<FreeChunk, AdaptiveFreeList>::min_size()*HeapWordSize == sizeof(TreeChunk<FreeChunk, AdaptiveFreeList>)),
     "else MIN_TREE_CHUNK_SIZE is wrong");
   assert(IndexSetStart != 0, "IndexSetStart not initialized");
   assert(IndexSetStride != 0, "IndexSetStride not initialized");
@@ -2529,15 +2531,15 @@
 
 void CompactibleFreeListSpace::printFLCensus(size_t sweep_count) const {
   assert_lock_strong(&_freelistLock);
-  FreeList<FreeChunk> total;
+  AdaptiveFreeList<FreeChunk> total;
   gclog_or_tty->print("end sweep# " SIZE_FORMAT "\n", sweep_count);
-  FreeList<FreeChunk>::print_labels_on(gclog_or_tty, "size");
+  AdaptiveFreeList<FreeChunk>::print_labels_on(gclog_or_tty, "size");
   size_t total_free = 0;
   for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
-    const FreeList<FreeChunk> *fl = &_indexedFreeList[i];
+    const AdaptiveFreeList<FreeChunk> *fl = &_indexedFreeList[i];
     total_free += fl->count() * fl->size();
     if (i % (40*IndexSetStride) == 0) {
-      FreeList<FreeChunk>::print_labels_on(gclog_or_tty, "size");
+      AdaptiveFreeList<FreeChunk>::print_labels_on(gclog_or_tty, "size");
     }
     fl->print_on(gclog_or_tty);
     total.set_bfr_surp(    total.bfr_surp()     + fl->bfr_surp()    );
@@ -2620,7 +2622,7 @@
     res = _cfls->getChunkFromDictionaryExact(word_sz);
     if (res == NULL) return NULL;
   } else {
-    FreeList<FreeChunk>* fl = &_indexedFreeList[word_sz];
+    AdaptiveFreeList<FreeChunk>* fl = &_indexedFreeList[word_sz];
     if (fl->count() == 0) {
       // Attempt to refill this local free list.
       get_from_global_pool(word_sz, fl);
@@ -2640,7 +2642,7 @@
 
 // Get a chunk of blocks of the right size and update related
 // book-keeping stats
-void CFLS_LAB::get_from_global_pool(size_t word_sz, FreeList<FreeChunk>* fl) {
+void CFLS_LAB::get_from_global_pool(size_t word_sz, AdaptiveFreeList<FreeChunk>* fl) {
   // Get the #blocks we want to claim
   size_t n_blks = (size_t)_blocks_to_claim[word_sz].average();
   assert(n_blks > 0, "Error");
@@ -2722,7 +2724,7 @@
         if (num_retire > 0) {
           _cfls->_indexedFreeList[i].prepend(&_indexedFreeList[i]);
           // Reset this list.
-          _indexedFreeList[i] = FreeList<FreeChunk>();
+          _indexedFreeList[i] = AdaptiveFreeList<FreeChunk>();
           _indexedFreeList[i].set_size(i);
         }
       }
@@ -2736,7 +2738,7 @@
   }
 }
 
-void CompactibleFreeListSpace:: par_get_chunk_of_blocks(size_t word_sz, size_t n, FreeList<FreeChunk>* fl) {
+void CompactibleFreeListSpace:: par_get_chunk_of_blocks(size_t word_sz, size_t n, AdaptiveFreeList<FreeChunk>* fl) {
   assert(fl->count() == 0, "Precondition.");
   assert(word_sz < CompactibleFreeListSpace::IndexSetSize,
          "Precondition");
@@ -2752,12 +2754,12 @@
          (cur_sz < CompactibleFreeListSpace::IndexSetSize) &&
          (CMSSplitIndexedFreeListBlocks || k <= 1);
          k++, cur_sz = k * word_sz) {
-      FreeList<FreeChunk> fl_for_cur_sz;  // Empty.
+      AdaptiveFreeList<FreeChunk> fl_for_cur_sz;  // Empty.
       fl_for_cur_sz.set_size(cur_sz);
       {
         MutexLockerEx x(_indexedFreeListParLocks[cur_sz],
                         Mutex::_no_safepoint_check_flag);
-        FreeList<FreeChunk>* gfl = &_indexedFreeList[cur_sz];
+        AdaptiveFreeList<FreeChunk>* gfl = &_indexedFreeList[cur_sz];
         if (gfl->count() != 0) {
           // nn is the number of chunks of size cur_sz that
           // we'd need to split k-ways each, in order to create
@@ -2832,12 +2834,11 @@
     MutexLockerEx x(parDictionaryAllocLock(),
                     Mutex::_no_safepoint_check_flag);
     while (n > 0) {
-      fc = dictionary()->get_chunk(MAX2(n * word_sz,
-                                  _dictionary->min_size()),
+      fc = dictionary()->get_chunk(MAX2(n * word_sz, _dictionary->min_size()),
                                   FreeBlockDictionary<FreeChunk>::atLeast);
       if (fc != NULL) {
         _bt.allocated((HeapWord*)fc, fc->size(), true /* reducing */);  // update _unallocated_blk
-        dictionary()->dict_census_udpate(fc->size(),
+        dictionary()->dict_census_update(fc->size(),
                                        true /*split*/,
                                        false /*birth*/);
         break;
@@ -2890,7 +2891,7 @@
       fc->set_size(prefix_size);
       if (rem >= IndexSetSize) {
         returnChunkToDictionary(rem_fc);
-        dictionary()->dict_census_udpate(rem, true /*split*/, true /*birth*/);
+        dictionary()->dict_census_update(rem, true /*split*/, true /*birth*/);
         rem_fc = NULL;
       }
       // Otherwise, return it to the small list below.
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_COMPACTIBLEFREELISTSPACE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_COMPACTIBLEFREELISTSPACE_HPP
 
+#include "gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp"
 #include "gc_implementation/concurrentMarkSweep/promotionInfo.hpp"
 #include "memory/binaryTreeDictionary.hpp"
 #include "memory/blockOffsetTable.inline.hpp"
@@ -38,6 +39,7 @@
 class CompactibleFreeListSpace;
 class BlkClosure;
 class BlkClosureCareful;
+class FreeChunk;
 class UpwardsObjectClosure;
 class ObjectClosureCareful;
 class Klass;
@@ -131,7 +133,7 @@
   FreeBlockDictionary<FreeChunk>::DictionaryChoice _dictionaryChoice;
   FreeBlockDictionary<FreeChunk>* _dictionary;    // ptr to dictionary for large size blocks
 
-  FreeList<FreeChunk> _indexedFreeList[IndexSetSize];
+  AdaptiveFreeList<FreeChunk> _indexedFreeList[IndexSetSize];
                                        // indexed array for small size blocks
   // allocation stategy
   bool       _fitStrategy;      // Use best fit strategy.
@@ -168,7 +170,7 @@
   // If the count of "fl" is negative, it's absolute value indicates a
   // number of free chunks that had been previously "borrowed" from global
   // list of size "word_sz", and must now be decremented.
-  void par_get_chunk_of_blocks(size_t word_sz, size_t n, FreeList<FreeChunk>* fl);
+  void par_get_chunk_of_blocks(size_t word_sz, size_t n, AdaptiveFreeList<FreeChunk>* fl);
 
   // Allocation helper functions
   // Allocate using a strategy that takes from the indexed free lists
@@ -214,7 +216,7 @@
   // and return it.  The split off remainder is returned to
   // the free lists.  The old name for getFromListGreater
   // was lookInListGreater.
-  FreeChunk* getFromListGreater(FreeList<FreeChunk>* fl, size_t numWords);
+  FreeChunk* getFromListGreater(AdaptiveFreeList<FreeChunk>* fl, size_t numWords);
   // Get a chunk in the indexed free list or dictionary,
   // by considering a larger chunk and splitting it.
   FreeChunk* getChunkFromGreater(size_t numWords);
@@ -621,7 +623,7 @@
   CompactibleFreeListSpace* _cfls;
 
   // Our local free lists.
-  FreeList<FreeChunk> _indexedFreeList[CompactibleFreeListSpace::IndexSetSize];
+  AdaptiveFreeList<FreeChunk> _indexedFreeList[CompactibleFreeListSpace::IndexSetSize];
 
   // Initialized from a command-line arg.
 
@@ -634,7 +636,7 @@
   size_t        _num_blocks        [CompactibleFreeListSpace::IndexSetSize];
 
   // Internal work method
-  void get_from_global_pool(size_t word_sz, FreeList<FreeChunk>* fl);
+  void get_from_global_pool(size_t word_sz, AdaptiveFreeList<FreeChunk>* fl);
 
 public:
   CFLS_LAB(CompactibleFreeListSpace* cfls);
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -9143,7 +9143,7 @@
     size_t shrinkable_size_in_bytes = chunk_at_end->size();
     size_t aligned_shrinkable_size_in_bytes =
       align_size_down(shrinkable_size_in_bytes, os::vm_page_size());
-    assert(unallocated_start <= chunk_at_end->end(),
+    assert(unallocated_start <= (HeapWord*) chunk_at_end->end(),
       "Inconsistent chunk at end of space");
     size_t bytes = MIN2(desired_bytes, aligned_shrinkable_size_in_bytes);
     size_t word_size_before = heap_word_size(_virtual_space.committed_size());
@@ -9210,7 +9210,7 @@
 
     assert(_cmsSpace->unallocated_block() <= _cmsSpace->end(),
       "Inconsistency at end of space");
-    assert(chunk_at_end->end() == _cmsSpace->end(),
+    assert(chunk_at_end->end() == (uintptr_t*) _cmsSpace->end(),
       "Shrinking is inconsistent");
     return;
   }
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -133,7 +133,7 @@
   }
 
   // Return the address past the end of this chunk
-  HeapWord* end() const { return ((HeapWord*) this) + size(); }
+  uintptr_t* end() const { return ((uintptr_t*) this) + size(); }
 
   // debugging
   void verify()             const PRODUCT_RETURN;
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -25,6 +25,8 @@
 #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_VMSTRUCTS_CMS_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_VMSTRUCTS_CMS_HPP
 
+typedef BinaryTreeDictionary<FreeChunk, AdaptiveFreeList> AFLBinaryTreeDictionary;
+
 #define VM_STRUCTS_CMS(nonstatic_field, \
                    volatile_nonstatic_field, \
                    static_field) \
@@ -38,14 +40,8 @@
   nonstatic_field(CMSCollector,                _markBitMap,                                   CMSBitMap)                             \
   nonstatic_field(ConcurrentMarkSweepGeneration, _cmsSpace,                                   CompactibleFreeListSpace*)             \
      static_field(ConcurrentMarkSweepThread,   _collector,                                    CMSCollector*)                         \
-  volatile_nonstatic_field(FreeChunk,          _size,                                         size_t)                                \
-  nonstatic_field(FreeChunk,                   _next,                                         FreeChunk*)                            \
-  nonstatic_field(FreeChunk,                   _prev,                                         FreeChunk*)                            \
   nonstatic_field(LinearAllocBlock,            _word_size,                                    size_t)                                \
-  nonstatic_field(FreeList<FreeChunk>,         _size,                                         size_t)                                \
-  nonstatic_field(FreeList<FreeChunk>,         _count,                                        ssize_t)                               \
-  nonstatic_field(BinaryTreeDictionary<FreeChunk>,_total_size,                                 size_t)                                \
-  nonstatic_field(CompactibleFreeListSpace,    _dictionary,                                   FreeBlockDictionary<FreeChunk>*)       \
+  nonstatic_field(AFLBinaryTreeDictionary,     _total_size,                                   size_t)                                \
   nonstatic_field(CompactibleFreeListSpace,    _indexedFreeList[0],                           FreeList<FreeChunk>)                   \
   nonstatic_field(CompactibleFreeListSpace,    _smallLinearAllocBlock,                        LinearAllocBlock)
 
@@ -60,19 +56,17 @@
   declare_toplevel_type(CMSCollector)                                     \
   declare_toplevel_type(CMSBitMap)                                        \
   declare_toplevel_type(FreeChunk)                                        \
+  declare_toplevel_type(Metablock)                                        \
   declare_toplevel_type(ConcurrentMarkSweepThread*)                       \
   declare_toplevel_type(ConcurrentMarkSweepGeneration*)                   \
   declare_toplevel_type(SurrogateLockerThread*)                           \
   declare_toplevel_type(CompactibleFreeListSpace*)                        \
   declare_toplevel_type(CMSCollector*)                                    \
-  declare_toplevel_type(FreeChunk*)                                       \
-  declare_toplevel_type(BinaryTreeDictionary<FreeChunk>*)                 \
-  declare_toplevel_type(FreeBlockDictionary<FreeChunk>*)                  \
-  declare_toplevel_type(FreeList<FreeChunk>*)                             \
-  declare_toplevel_type(FreeList<FreeChunk>)                              \
+  declare_toplevel_type(AFLBinaryTreeDictionary*)                         \
   declare_toplevel_type(LinearAllocBlock)                                 \
   declare_toplevel_type(FreeBlockDictionary<FreeChunk>)                   \
-            declare_type(BinaryTreeDictionary<FreeChunk>, FreeBlockDictionary<FreeChunk>)
+  declare_type(AFLBinaryTreeDictionary, FreeBlockDictionary<FreeChunk>)   \
+            declare_type(AFLBinaryTreeDictionary, FreeBlockDictionary<FreeChunk>) \
 
 #define VM_INT_CONSTANTS_CMS(declare_constant)                            \
   declare_constant(Generation::ConcurrentMarkSweep)                       \
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -191,7 +191,7 @@
 class VM_CollectForMetadataAllocation: public VM_GC_Operation {
  private:
   MetaWord*                _result;
-  size_t      _size;                       // size of object to be allocated
+  size_t                   _size;     // size of object to be allocated
   Metaspace::MetadataType  _mdtype;
   ClassLoaderData*         _loader_data;
  public:
--- a/src/share/vm/memory/binaryTreeDictionary.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/binaryTreeDictionary.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -25,9 +25,15 @@
 #include "precompiled.hpp"
 #include "gc_implementation/shared/allocationStats.hpp"
 #include "memory/binaryTreeDictionary.hpp"
+#include "memory/freeList.hpp"
+#include "memory/freeBlockDictionary.hpp"
+#include "memory/metablock.hpp"
+#include "memory/metachunk.hpp"
 #include "runtime/globals.hpp"
 #include "utilities/ostream.hpp"
 #ifndef SERIALGC
+#include "gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp"
+#include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
 #endif // SERIALGC
@@ -37,15 +43,18 @@
 // This is currently used in the Concurrent Mark&Sweep implementation.
 ////////////////////////////////////////////////////////////////////////////////
 
-template <class Chunk>
-TreeChunk<Chunk>* TreeChunk<Chunk>::as_TreeChunk(Chunk* fc) {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t TreeChunk<Chunk_t, FreeList_t>::_min_tree_chunk_size = sizeof(TreeChunk<Chunk_t,  FreeList_t>)/HeapWordSize;
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>* TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(Chunk_t* fc) {
   // Do some assertion checking here.
-  return (TreeChunk<Chunk>*) fc;
+  return (TreeChunk<Chunk_t, FreeList_t>*) fc;
 }
 
-template <class Chunk>
-void TreeChunk<Chunk>::verify_tree_chunk_list() const {
-  TreeChunk<Chunk>* nextTC = (TreeChunk<Chunk>*)next();
+template <class Chunk_t, template <class> class FreeList_t>
+void TreeChunk<Chunk_t, FreeList_t>::verify_tree_chunk_list() const {
+  TreeChunk<Chunk_t, FreeList_t>* nextTC = (TreeChunk<Chunk_t, FreeList_t>*)next();
   if (prev() != NULL) { // interior list node shouldn'r have tree fields
     guarantee(embedded_list()->parent() == NULL && embedded_list()->left() == NULL &&
               embedded_list()->right()  == NULL, "should be clear");
@@ -57,53 +66,113 @@
   }
 }
 
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>::TreeList() {}
 
-template <class Chunk>
-TreeList<Chunk>* TreeList<Chunk>::as_TreeList(TreeChunk<Chunk>* tc) {
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>*
+TreeList<Chunk_t, FreeList_t>::as_TreeList(TreeChunk<Chunk_t,FreeList_t>* tc) {
   // This first free chunk in the list will be the tree list.
-  assert(tc->size() >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "Chunk is too small for a TreeChunk");
-  TreeList<Chunk>* tl = tc->embedded_list();
+  assert((tc->size() >= (TreeChunk<Chunk_t, FreeList_t>::min_size())),
+    "Chunk is too small for a TreeChunk");
+  TreeList<Chunk_t, FreeList_t>* tl = tc->embedded_list();
+  tl->initialize();
   tc->set_list(tl);
-#ifdef ASSERT
-  tl->set_protecting_lock(NULL);
-#endif
-  tl->set_hint(0);
   tl->set_size(tc->size());
   tl->link_head(tc);
   tl->link_tail(tc);
   tl->set_count(1);
-  tl->init_statistics(true /* split_birth */);
-  tl->set_parent(NULL);
-  tl->set_left(NULL);
-  tl->set_right(NULL);
+
   return tl;
 }
 
-template <class Chunk>
-TreeList<Chunk>* TreeList<Chunk>::as_TreeList(HeapWord* addr, size_t size) {
-  TreeChunk<Chunk>* tc = (TreeChunk<Chunk>*) addr;
-  assert(size >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "Chunk is too small for a TreeChunk");
-  // The space in the heap will have been mangled initially but
-  // is not remangled when a free chunk is returned to the free list
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>*
+get_chunk(size_t size, enum FreeBlockDictionary<Chunk_t>::Dither dither) {
+  FreeBlockDictionary<Chunk_t>::verify_par_locked();
+  Chunk_t* res = get_chunk_from_tree(size, dither);
+  assert(res == NULL || res->is_free(),
+         "Should be returning a free chunk");
+  assert(dither != FreeBlockDictionary<Chunk_t>::exactly ||
+         res->size() == size, "Not correct size");
+  return res;
+}
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>*
+TreeList<Chunk_t, FreeList_t>::as_TreeList(HeapWord* addr, size_t size) {
+  TreeChunk<Chunk_t, FreeList_t>* tc = (TreeChunk<Chunk_t, FreeList_t>*) addr;
+  assert((size >= TreeChunk<Chunk_t, FreeList_t>::min_size()),
+    "Chunk is too small for a TreeChunk");
+  // The space will have been mangled initially but
+  // is not remangled when a Chunk_t is returned to the free list
   // (since it is used to maintain the chunk on the free list).
-  assert((ZapUnusedHeapArea &&
-          SpaceMangler::is_mangled((HeapWord*) tc->size_addr()) &&
-          SpaceMangler::is_mangled((HeapWord*) tc->prev_addr()) &&
-          SpaceMangler::is_mangled((HeapWord*) tc->next_addr())) ||
-          (tc->size() == 0 && tc->prev() == NULL && tc->next() == NULL),
-    "Space should be clear or mangled");
+  tc->assert_is_mangled();
   tc->set_size(size);
   tc->link_prev(NULL);
   tc->link_next(NULL);
-  TreeList<Chunk>* tl = TreeList<Chunk>::as_TreeList(tc);
+  TreeList<Chunk_t, FreeList_t>* tl = TreeList<Chunk_t, FreeList_t>::as_TreeList(tc);
   return tl;
 }
 
-template <class Chunk>
-TreeList<Chunk>* TreeList<Chunk>::remove_chunk_replace_if_needed(TreeChunk<Chunk>* tc) {
 
-  TreeList<Chunk>* retTL = this;
-  Chunk* list = head();
+#ifndef SERIALGC
+// Specialize for AdaptiveFreeList which tries to avoid
+// splitting a chunk of a size that is under populated in favor of
+// an over populated size.  The general get_better_list() just returns
+// the current list.
+template <>
+TreeList<FreeChunk, AdaptiveFreeList>*
+TreeList<FreeChunk, AdaptiveFreeList>::get_better_list(
+  BinaryTreeDictionary<FreeChunk, ::AdaptiveFreeList>* dictionary) {
+  // A candidate chunk has been found.  If it is already under
+  // populated, get a chunk associated with the hint for this
+  // chunk.
+
+  TreeList<FreeChunk, ::AdaptiveFreeList>* curTL = this;
+  if (surplus() <= 0) {
+    /* Use the hint to find a size with a surplus, and reset the hint. */
+    TreeList<FreeChunk, ::AdaptiveFreeList>* hintTL = this;
+    while (hintTL->hint() != 0) {
+      assert(hintTL->hint() > hintTL->size(),
+        "hint points in the wrong direction");
+      hintTL = dictionary->find_list(hintTL->hint());
+      assert(curTL != hintTL, "Infinite loop");
+      if (hintTL == NULL ||
+          hintTL == curTL /* Should not happen but protect against it */ ) {
+        // No useful hint.  Set the hint to NULL and go on.
+        curTL->set_hint(0);
+        break;
+      }
+      assert(hintTL->size() > curTL->size(), "hint is inconsistent");
+      if (hintTL->surplus() > 0) {
+        // The hint led to a list that has a surplus.  Use it.
+        // Set the hint for the candidate to an overpopulated
+        // size.
+        curTL->set_hint(hintTL->size());
+        // Change the candidate.
+        curTL = hintTL;
+        break;
+      }
+    }
+  }
+  return curTL;
+}
+#endif // SERIALGC
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>*
+TreeList<Chunk_t, FreeList_t>::get_better_list(
+  BinaryTreeDictionary<Chunk_t, FreeList_t>* dictionary) {
+  return this;
+}
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::remove_chunk_replace_if_needed(TreeChunk<Chunk_t, FreeList_t>* tc) {
+
+  TreeList<Chunk_t, FreeList_t>* retTL = this;
+  Chunk_t* list = head();
   assert(!list || list != list->next(), "Chunk on list twice");
   assert(tc != NULL, "Chunk being removed is NULL");
   assert(parent() == NULL || this == parent()->left() ||
@@ -112,13 +181,13 @@
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
 
-  Chunk* prevFC = tc->prev();
-  TreeChunk<Chunk>* nextTC = TreeChunk<Chunk>::as_TreeChunk(tc->next());
+  Chunk_t* prevFC = tc->prev();
+  TreeChunk<Chunk_t, FreeList_t>* nextTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(tc->next());
   assert(list != NULL, "should have at least the target chunk");
 
   // Is this the first item on the list?
   if (tc == list) {
-    // The "getChunk..." functions for a TreeList<Chunk> will not return the
+    // The "getChunk..." functions for a TreeList<Chunk_t, FreeList_t> will not return the
     // first chunk in the list unless it is the last chunk in the list
     // because the first chunk is also acting as the tree node.
     // When coalescing happens, however, the first chunk in the a tree
@@ -127,8 +196,8 @@
     // allocated when the sweeper yields (giving up the free list lock)
     // to allow mutator activity.  If this chunk is the first in the
     // list and is not the last in the list, do the work to copy the
-    // TreeList<Chunk> from the first chunk to the next chunk and update all
-    // the TreeList<Chunk> pointers in the chunks in the list.
+    // TreeList<Chunk_t, FreeList_t> from the first chunk to the next chunk and update all
+    // the TreeList<Chunk_t, FreeList_t> pointers in the chunks in the list.
     if (nextTC == NULL) {
       assert(prevFC == NULL, "Not last chunk in the list");
       set_tail(NULL);
@@ -141,11 +210,11 @@
       // This can be slow for a long list.  Consider having
       // an option that does not allow the first chunk on the
       // list to be coalesced.
-      for (TreeChunk<Chunk>* curTC = nextTC; curTC != NULL;
-          curTC = TreeChunk<Chunk>::as_TreeChunk(curTC->next())) {
+      for (TreeChunk<Chunk_t, FreeList_t>* curTC = nextTC; curTC != NULL;
+          curTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(curTC->next())) {
         curTC->set_list(retTL);
       }
-      // Fix the parent to point to the new TreeList<Chunk>.
+      // Fix the parent to point to the new TreeList<Chunk_t, FreeList_t>.
       if (retTL->parent() != NULL) {
         if (this == retTL->parent()->left()) {
           retTL->parent()->set_left(retTL);
@@ -176,9 +245,9 @@
     prevFC->link_after(nextTC);
   }
 
-  // Below this point the embeded TreeList<Chunk> being used for the
+  // Below this point the embeded TreeList<Chunk_t, FreeList_t> being used for the
   // tree node may have changed. Don't use "this"
-  // TreeList<Chunk>*.
+  // TreeList<Chunk_t, FreeList_t>*.
   // chunk should still be a free chunk (bit set in _prev)
   assert(!retTL->head() || retTL->size() == retTL->head()->size(),
     "Wrong sized chunk in list");
@@ -188,7 +257,7 @@
     tc->set_list(NULL);
     bool prev_found = false;
     bool next_found = false;
-    for (Chunk* curFC = retTL->head();
+    for (Chunk_t* curFC = retTL->head();
          curFC != NULL; curFC = curFC->next()) {
       assert(curFC != tc, "Chunk is still in list");
       if (curFC == prevFC) {
@@ -215,8 +284,8 @@
   return retTL;
 }
 
-template <class Chunk>
-void TreeList<Chunk>::return_chunk_at_tail(TreeChunk<Chunk>* chunk) {
+template <class Chunk_t, template <class> class FreeList_t>
+void TreeList<Chunk_t, FreeList_t>::return_chunk_at_tail(TreeChunk<Chunk_t, FreeList_t>* chunk) {
   assert(chunk != NULL, "returning NULL chunk");
   assert(chunk->list() == this, "list should be set for chunk");
   assert(tail() != NULL, "The tree list is embedded in the first chunk");
@@ -225,12 +294,12 @@
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
 
-  Chunk* fc = tail();
+  Chunk_t* fc = tail();
   fc->link_after(chunk);
   link_tail(chunk);
 
   assert(!tail() || size() == tail()->size(), "Wrong sized chunk in list");
-  increment_count();
+  FreeList_t<Chunk_t>::increment_count();
   debug_only(increment_returned_bytes_by(chunk->size()*sizeof(HeapWord));)
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
@@ -238,10 +307,10 @@
 
 // Add this chunk at the head of the list.  "At the head of the list"
 // is defined to be after the chunk pointer to by head().  This is
-// because the TreeList<Chunk> is embedded in the first TreeChunk<Chunk> in the
-// list.  See the definition of TreeChunk<Chunk>.
-template <class Chunk>
-void TreeList<Chunk>::return_chunk_at_head(TreeChunk<Chunk>* chunk) {
+// because the TreeList<Chunk_t, FreeList_t> is embedded in the first TreeChunk<Chunk_t, FreeList_t> in the
+// list.  See the definition of TreeChunk<Chunk_t, FreeList_t>.
+template <class Chunk_t, template <class> class FreeList_t>
+void TreeList<Chunk_t, FreeList_t>::return_chunk_at_head(TreeChunk<Chunk_t, FreeList_t>* chunk) {
   assert(chunk->list() == this, "list should be set for chunk");
   assert(head() != NULL, "The tree list is embedded in the first chunk");
   assert(chunk != NULL, "returning NULL chunk");
@@ -249,7 +318,7 @@
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
 
-  Chunk* fc = head()->next();
+  Chunk_t* fc = head()->next();
   if (fc != NULL) {
     chunk->link_after(fc);
   } else {
@@ -258,28 +327,38 @@
   }
   head()->link_after(chunk);
   assert(!head() || size() == head()->size(), "Wrong sized chunk in list");
-  increment_count();
+  FreeList_t<Chunk_t>::increment_count();
   debug_only(increment_returned_bytes_by(chunk->size()*sizeof(HeapWord));)
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
 }
 
-template <class Chunk>
-TreeChunk<Chunk>* TreeList<Chunk>::head_as_TreeChunk() {
-  assert(head() == NULL || TreeChunk<Chunk>::as_TreeChunk(head())->list() == this,
-    "Wrong type of chunk?");
-  return TreeChunk<Chunk>::as_TreeChunk(head());
+template <class Chunk_t, template <class> class FreeList_t>
+void TreeChunk<Chunk_t, FreeList_t>::assert_is_mangled() const {
+  assert((ZapUnusedHeapArea &&
+          SpaceMangler::is_mangled((HeapWord*) Chunk_t::size_addr()) &&
+          SpaceMangler::is_mangled((HeapWord*) Chunk_t::prev_addr()) &&
+          SpaceMangler::is_mangled((HeapWord*) Chunk_t::next_addr())) ||
+          (size() == 0 && prev() == NULL && next() == NULL),
+    "Space should be clear or mangled");
 }
 
-template <class Chunk>
-TreeChunk<Chunk>* TreeList<Chunk>::first_available() {
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::head_as_TreeChunk() {
+  assert(head() == NULL || (TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(head())->list() == this),
+    "Wrong type of chunk?");
+  return TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(head());
+}
+
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::first_available() {
   assert(head() != NULL, "The head of the list cannot be NULL");
-  Chunk* fc = head()->next();
-  TreeChunk<Chunk>* retTC;
+  Chunk_t* fc = head()->next();
+  TreeChunk<Chunk_t, FreeList_t>* retTC;
   if (fc == NULL) {
     retTC = head_as_TreeChunk();
   } else {
-    retTC = TreeChunk<Chunk>::as_TreeChunk(fc);
+    retTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(fc);
   }
   assert(retTC->list() == this, "Wrong type of chunk.");
   return retTC;
@@ -288,41 +367,32 @@
 // Returns the block with the largest heap address amongst
 // those in the list for this size; potentially slow and expensive,
 // use with caution!
-template <class Chunk>
-TreeChunk<Chunk>* TreeList<Chunk>::largest_address() {
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::largest_address() {
   assert(head() != NULL, "The head of the list cannot be NULL");
-  Chunk* fc = head()->next();
-  TreeChunk<Chunk>* retTC;
+  Chunk_t* fc = head()->next();
+  TreeChunk<Chunk_t, FreeList_t>* retTC;
   if (fc == NULL) {
     retTC = head_as_TreeChunk();
   } else {
     // walk down the list and return the one with the highest
     // heap address among chunks of this size.
-    Chunk* last = fc;
+    Chunk_t* last = fc;
     while (fc->next() != NULL) {
       if ((HeapWord*)last < (HeapWord*)fc) {
         last = fc;
       }
       fc = fc->next();
     }
-    retTC = TreeChunk<Chunk>::as_TreeChunk(last);
+    retTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(last);
   }
   assert(retTC->list() == this, "Wrong type of chunk.");
   return retTC;
 }
 
-template <class Chunk>
-BinaryTreeDictionary<Chunk>::BinaryTreeDictionary(bool adaptive_freelists, bool splay) :
-  _splay(splay), _adaptive_freelists(adaptive_freelists),
-  _total_size(0), _total_free_blocks(0), _root(0) {}
-
-template <class Chunk>
-BinaryTreeDictionary<Chunk>::BinaryTreeDictionary(MemRegion mr,
-                                           bool adaptive_freelists,
-                                           bool splay):
-  _adaptive_freelists(adaptive_freelists), _splay(splay)
-{
-  assert(mr.word_size() >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "minimum chunk size");
+template <class Chunk_t, template <class> class FreeList_t>
+BinaryTreeDictionary<Chunk_t, FreeList_t>::BinaryTreeDictionary(MemRegion mr) {
+  assert((mr.byte_size() > min_size()), "minimum chunk size");
 
   reset(mr);
   assert(root()->left() == NULL, "reset check failed");
@@ -333,52 +403,48 @@
   assert(total_free_blocks() == 1, "reset check failed");
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::inc_total_size(size_t inc) {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::inc_total_size(size_t inc) {
   _total_size = _total_size + inc;
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::dec_total_size(size_t dec) {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::dec_total_size(size_t dec) {
   _total_size = _total_size - dec;
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::reset(MemRegion mr) {
-  assert(mr.word_size() >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "minimum chunk size");
-  set_root(TreeList<Chunk>::as_TreeList(mr.start(), mr.word_size()));
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset(MemRegion mr) {
+  assert((mr.byte_size() > min_size()), "minimum chunk size");
+  set_root(TreeList<Chunk_t, FreeList_t>::as_TreeList(mr.start(), mr.word_size()));
   set_total_size(mr.word_size());
   set_total_free_blocks(1);
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::reset(HeapWord* addr, size_t byte_size) {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset(HeapWord* addr, size_t byte_size) {
   MemRegion mr(addr, heap_word_size(byte_size));
   reset(mr);
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::reset() {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset() {
   set_root(NULL);
   set_total_size(0);
   set_total_free_blocks(0);
 }
 
 // Get a free block of size at least size from tree, or NULL.
-// If a splay step is requested, the removal algorithm (only) incorporates
-// a splay step as follows:
-// . the search proceeds down the tree looking for a possible
-//   match. At the (closest) matching location, an appropriate splay step is applied
-//   (zig, zig-zig or zig-zag). A chunk of the appropriate size is then returned
-//   if available, and if it's the last chunk, the node is deleted. A deteleted
-//   node is replaced in place by its tree successor.
-template <class Chunk>
-TreeChunk<Chunk>*
-BinaryTreeDictionary<Chunk>::get_chunk_from_tree(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither, bool splay)
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>*
+BinaryTreeDictionary<Chunk_t, FreeList_t>::get_chunk_from_tree(
+                              size_t size,
+                              enum FreeBlockDictionary<Chunk_t>::Dither dither)
 {
-  TreeList<Chunk> *curTL, *prevTL;
-  TreeChunk<Chunk>* retTC = NULL;
-  assert(size >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "minimum chunk size");
+  TreeList<Chunk_t, FreeList_t> *curTL, *prevTL;
+  TreeChunk<Chunk_t, FreeList_t>* retTC = NULL;
+
+  assert((size >= min_size()), "minimum chunk size");
   if (FLSVerifyDictionary) {
     verify_tree();
   }
@@ -398,7 +464,7 @@
   }
   if (curTL == NULL) { // couldn't find exact match
 
-    if (dither == FreeBlockDictionary<Chunk>::exactly) return NULL;
+    if (dither == FreeBlockDictionary<Chunk_t>::exactly) return NULL;
 
     // try and find the next larger size by walking back up the search path
     for (curTL = prevTL; curTL != NULL;) {
@@ -410,46 +476,9 @@
   }
   if (curTL != NULL) {
     assert(curTL->size() >= size, "size inconsistency");
-    if (adaptive_freelists()) {
 
-      // A candidate chunk has been found.  If it is already under
-      // populated, get a chunk associated with the hint for this
-      // chunk.
-      if (curTL->surplus() <= 0) {
-        /* Use the hint to find a size with a surplus, and reset the hint. */
-        TreeList<Chunk>* hintTL = curTL;
-        while (hintTL->hint() != 0) {
-          assert(hintTL->hint() == 0 || hintTL->hint() > hintTL->size(),
-            "hint points in the wrong direction");
-          hintTL = find_list(hintTL->hint());
-          assert(curTL != hintTL, "Infinite loop");
-          if (hintTL == NULL ||
-              hintTL == curTL /* Should not happen but protect against it */ ) {
-            // No useful hint.  Set the hint to NULL and go on.
-            curTL->set_hint(0);
-            break;
-          }
-          assert(hintTL->size() > size, "hint is inconsistent");
-          if (hintTL->surplus() > 0) {
-            // The hint led to a list that has a surplus.  Use it.
-            // Set the hint for the candidate to an overpopulated
-            // size.
-            curTL->set_hint(hintTL->size());
-            // Change the candidate.
-            curTL = hintTL;
-            break;
-          }
-          // The evm code reset the hint of the candidate as
-          // at an interim point.  Why?  Seems like this leaves
-          // the hint pointing to a list that didn't work.
-          // curTL->set_hint(hintTL->size());
-        }
-      }
-    }
-    // don't waste time splaying if chunk's singleton
-    if (splay && curTL->head()->next() != NULL) {
-      semi_splay_step(curTL);
-    }
+    curTL = curTL->get_better_list(this);
+
     retTC = curTL->first_available();
     assert((retTC != NULL) && (curTL->count() > 0),
       "A list in the binary tree should not be NULL");
@@ -465,9 +494,9 @@
   return retTC;
 }
 
-template <class Chunk>
-TreeList<Chunk>* BinaryTreeDictionary<Chunk>::find_list(size_t size) const {
-  TreeList<Chunk>* curTL;
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_list(size_t size) const {
+  TreeList<Chunk_t, FreeList_t>* curTL;
   for (curTL = root(); curTL != NULL;) {
     if (curTL->size() == size) {        // exact match
       break;
@@ -484,10 +513,10 @@
 }
 
 
-template <class Chunk>
-bool BinaryTreeDictionary<Chunk>::verify_chunk_in_free_list(Chunk* tc) const {
+template <class Chunk_t, template <class> class FreeList_t>
+bool BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_chunk_in_free_list(Chunk_t* tc) const {
   size_t size = tc->size();
-  TreeList<Chunk>* tl = find_list(size);
+  TreeList<Chunk_t, FreeList_t>* tl = find_list(size);
   if (tl == NULL) {
     return false;
   } else {
@@ -495,9 +524,9 @@
   }
 }
 
-template <class Chunk>
-Chunk* BinaryTreeDictionary<Chunk>::find_largest_dict() const {
-  TreeList<Chunk> *curTL = root();
+template <class Chunk_t, template <class> class FreeList_t>
+Chunk_t* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_largest_dict() const {
+  TreeList<Chunk_t, FreeList_t> *curTL = root();
   if (curTL != NULL) {
     while(curTL->right() != NULL) curTL = curTL->right();
     return curTL->largest_address();
@@ -510,15 +539,15 @@
 // chunk in a list on a tree node, just unlink it.
 // If it is the last chunk in the list (the next link is NULL),
 // remove the node and repair the tree.
-template <class Chunk>
-TreeChunk<Chunk>*
-BinaryTreeDictionary<Chunk>::remove_chunk_from_tree(TreeChunk<Chunk>* tc) {
+template <class Chunk_t, template <class> class FreeList_t>
+TreeChunk<Chunk_t, FreeList_t>*
+BinaryTreeDictionary<Chunk_t, FreeList_t>::remove_chunk_from_tree(TreeChunk<Chunk_t, FreeList_t>* tc) {
   assert(tc != NULL, "Should not call with a NULL chunk");
   assert(tc->is_free(), "Header is not marked correctly");
 
-  TreeList<Chunk> *newTL, *parentTL;
-  TreeChunk<Chunk>* retTC;
-  TreeList<Chunk>* tl = tc->list();
+  TreeList<Chunk_t, FreeList_t> *newTL, *parentTL;
+  TreeChunk<Chunk_t, FreeList_t>* retTC;
+  TreeList<Chunk_t, FreeList_t>* tl = tc->list();
   debug_only(
     bool removing_only_chunk = false;
     if (tl == _root) {
@@ -538,8 +567,8 @@
 
   retTC = tc;
   // Removing this chunk can have the side effect of changing the node
-  // (TreeList<Chunk>*) in the tree.  If the node is the root, update it.
-  TreeList<Chunk>* replacementTL = tl->remove_chunk_replace_if_needed(tc);
+  // (TreeList<Chunk_t, FreeList_t>*) in the tree.  If the node is the root, update it.
+  TreeList<Chunk_t, FreeList_t>* replacementTL = tl->remove_chunk_replace_if_needed(tc);
   assert(tc->is_free(), "Chunk should still be free");
   assert(replacementTL->parent() == NULL ||
          replacementTL == replacementTL->parent()->left() ||
@@ -549,17 +578,18 @@
     assert(replacementTL->parent() == NULL, "Incorrectly replacing root");
     set_root(replacementTL);
   }
-  debug_only(
+#ifdef ASSERT
     if (tl != replacementTL) {
       assert(replacementTL->head() != NULL,
         "If the tree list was replaced, it should not be a NULL list");
-      TreeList<Chunk>* rhl = replacementTL->head_as_TreeChunk()->list();
-      TreeList<Chunk>* rtl = TreeChunk<Chunk>::as_TreeChunk(replacementTL->tail())->list();
+      TreeList<Chunk_t, FreeList_t>* rhl = replacementTL->head_as_TreeChunk()->list();
+      TreeList<Chunk_t, FreeList_t>* rtl =
+        TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(replacementTL->tail())->list();
       assert(rhl == replacementTL, "Broken head");
       assert(rtl == replacementTL, "Broken tail");
       assert(replacementTL->size() == tc->size(),  "Broken size");
     }
-  )
+#endif
 
   // Does the tree need to be repaired?
   if (replacementTL->count() == 0) {
@@ -574,7 +604,7 @@
     } else if (replacementTL->right() == NULL) {
       // right is NULL
       newTL = replacementTL->left();
-      debug_only(replacementTL->clearLeft();)
+      debug_only(replacementTL->clear_left();)
     } else {  // we have both children, so, by patriarchal convention,
               // my replacement is least node in right sub-tree
       complicated_splice = true;
@@ -623,7 +653,7 @@
       newTL->set_right(replacementTL->right());
       debug_only(
         replacementTL->clear_right();
-        replacementTL->clearLeft();
+        replacementTL->clear_left();
       )
     }
     assert(replacementTL->right() == NULL &&
@@ -644,21 +674,21 @@
     verify_tree();
   }
   assert(!removing_only_chunk || _root == NULL, "root should be NULL");
-  return TreeChunk<Chunk>::as_TreeChunk(retTC);
+  return TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(retTC);
 }
 
 // Remove the leftmost node (lm) in the tree and return it.
 // If lm has a right child, link it to the left node of
 // the parent of lm.
-template <class Chunk>
-TreeList<Chunk>* BinaryTreeDictionary<Chunk>::remove_tree_minimum(TreeList<Chunk>* tl) {
+template <class Chunk_t, template <class> class FreeList_t>
+TreeList<Chunk_t, FreeList_t>* BinaryTreeDictionary<Chunk_t, FreeList_t>::remove_tree_minimum(TreeList<Chunk_t, FreeList_t>* tl) {
   assert(tl != NULL && tl->parent() != NULL, "really need a proper sub-tree");
   // locate the subtree minimum by walking down left branches
-  TreeList<Chunk>* curTL = tl;
+  TreeList<Chunk_t, FreeList_t>* curTL = tl;
   for (; curTL->left() != NULL; curTL = curTL->left());
   // obviously curTL now has at most one child, a right child
   if (curTL != root()) {  // Should this test just be removed?
-    TreeList<Chunk>* parentTL = curTL->parent();
+    TreeList<Chunk_t, FreeList_t>* parentTL = curTL->parent();
     if (parentTL->left() == curTL) { // curTL is a left child
       parentTL->set_left(curTL->right());
     } else {
@@ -685,31 +715,14 @@
   return curTL;
 }
 
-// Based on a simplification of the algorithm by Sleator and Tarjan (JACM 1985).
-// The simplifications are the following:
-// . we splay only when we delete (not when we insert)
-// . we apply a single spay step per deletion/access
-// By doing such partial splaying, we reduce the amount of restructuring,
-// while getting a reasonably efficient search tree (we think).
-// [Measurements will be needed to (in)validate this expectation.]
-
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::semi_splay_step(TreeList<Chunk>* tc) {
-  // apply a semi-splay step at the given node:
-  // . if root, norting needs to be done
-  // . if child of root, splay once
-  // . else zig-zig or sig-zag depending on path from grandparent
-  if (root() == tc) return;
-  warning("*** Splaying not yet implemented; "
-          "tree operations may be inefficient ***");
-}
-
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::insert_chunk_in_tree(Chunk* fc) {
-  TreeList<Chunk> *curTL, *prevTL;
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::insert_chunk_in_tree(Chunk_t* fc) {
+  TreeList<Chunk_t, FreeList_t> *curTL, *prevTL;
   size_t size = fc->size();
 
-  assert(size >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "too small to be a TreeList<Chunk>");
+  assert((size >= min_size()),
+    err_msg(SIZE_FORMAT " is too small to be a TreeChunk<Chunk_t, FreeList_t> " SIZE_FORMAT,
+      size, min_size()));
   if (FLSVerifyDictionary) {
     verify_tree();
   }
@@ -729,9 +742,9 @@
       curTL = curTL->right();
     }
   }
-  TreeChunk<Chunk>* tc = TreeChunk<Chunk>::as_TreeChunk(fc);
+  TreeChunk<Chunk_t, FreeList_t>* tc = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(fc);
   // This chunk is being returned to the binary tree.  Its embedded
-  // TreeList<Chunk> should be unused at this point.
+  // TreeList<Chunk_t, FreeList_t> should be unused at this point.
   tc->initialize();
   if (curTL != NULL) {          // exact match
     tc->set_list(curTL);
@@ -739,8 +752,8 @@
   } else {                     // need a new node in tree
     tc->clear_next();
     tc->link_prev(NULL);
-    TreeList<Chunk>* newTL = TreeList<Chunk>::as_TreeList(tc);
-    assert(((TreeChunk<Chunk>*)tc)->list() == newTL,
+    TreeList<Chunk_t, FreeList_t>* newTL = TreeList<Chunk_t, FreeList_t>::as_TreeList(tc);
+    assert(((TreeChunk<Chunk_t, FreeList_t>*)tc)->list() == newTL,
       "List was not initialized correctly");
     if (prevTL == NULL) {      // we are the only tree node
       assert(root() == NULL, "control point invariant");
@@ -768,30 +781,30 @@
   }
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::max_chunk_size() const {
-  FreeBlockDictionary<Chunk>::verify_par_locked();
-  TreeList<Chunk>* tc = root();
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::max_chunk_size() const {
+  FreeBlockDictionary<Chunk_t>::verify_par_locked();
+  TreeList<Chunk_t, FreeList_t>* tc = root();
   if (tc == NULL) return 0;
   for (; tc->right() != NULL; tc = tc->right());
   return tc->size();
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_list_length(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_list_length(TreeList<Chunk_t, FreeList_t>* tl) const {
   size_t res;
   res = tl->count();
 #ifdef ASSERT
   size_t cnt;
-  Chunk* tc = tl->head();
+  Chunk_t* tc = tl->head();
   for (cnt = 0; tc != NULL; tc = tc->next(), cnt++);
   assert(res == cnt, "The count is not being maintained correctly");
 #endif
   return res;
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_size_in_tree(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_size_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
   if (tl == NULL)
     return 0;
   return (tl->size() * total_list_length(tl)) +
@@ -799,8 +812,8 @@
          total_size_in_tree(tl->right());
 }
 
-template <class Chunk>
-double BinaryTreeDictionary<Chunk>::sum_of_squared_block_sizes(TreeList<Chunk>* const tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+double BinaryTreeDictionary<Chunk_t, FreeList_t>::sum_of_squared_block_sizes(TreeList<Chunk_t, FreeList_t>* const tl) const {
   if (tl == NULL) {
     return 0.0;
   }
@@ -811,8 +824,8 @@
   return curr;
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_free_blocks_in_tree(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_free_blocks_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
   if (tl == NULL)
     return 0;
   return total_list_length(tl) +
@@ -820,28 +833,28 @@
          total_free_blocks_in_tree(tl->right());
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::num_free_blocks() const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::num_free_blocks() const {
   assert(total_free_blocks_in_tree(root()) == total_free_blocks(),
          "_total_free_blocks inconsistency");
   return total_free_blocks();
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::tree_height_helper(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::tree_height_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
   if (tl == NULL)
     return 0;
   return 1 + MAX2(tree_height_helper(tl->left()),
                   tree_height_helper(tl->right()));
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::treeHeight() const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::tree_height() const {
   return tree_height_helper(root());
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_nodes_helper(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_nodes_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
   if (tl == NULL) {
     return 0;
   }
@@ -849,14 +862,18 @@
     total_nodes_helper(tl->right());
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_nodes_in_tree(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_nodes_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
   return total_nodes_helper(root());
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::dict_census_udpate(size_t size, bool split, bool birth){
-  TreeList<Chunk>* nd = find_list(size);
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::dict_census_update(size_t size, bool split, bool birth){}
+
+#ifndef SERIALGC
+template <>
+void BinaryTreeDictionary<FreeChunk, AdaptiveFreeList>::dict_census_update(size_t size, bool split, bool birth){
+  TreeList<FreeChunk, AdaptiveFreeList>* nd = find_list(size);
   if (nd) {
     if (split) {
       if (birth) {
@@ -882,16 +899,26 @@
   //   This is a birth associated with a LinAB.  The chunk
   //     for the LinAB is not in the dictionary.
 }
+#endif // SERIALGC
 
-template <class Chunk>
-bool BinaryTreeDictionary<Chunk>::coal_dict_over_populated(size_t size) {
+template <class Chunk_t, template <class> class FreeList_t>
+bool BinaryTreeDictionary<Chunk_t, FreeList_t>::coal_dict_over_populated(size_t size) {
+  // For the general type of freelists, encourage coalescing by
+  // returning true.
+  return true;
+}
+
+#ifndef SERIALGC
+template <>
+bool BinaryTreeDictionary<FreeChunk, AdaptiveFreeList>::coal_dict_over_populated(size_t size) {
   if (FLSAlwaysCoalesceLarge) return true;
 
-  TreeList<Chunk>* list_of_size = find_list(size);
+  TreeList<FreeChunk, AdaptiveFreeList>* list_of_size = find_list(size);
   // None of requested size implies overpopulated.
   return list_of_size == NULL || list_of_size->coal_desired() <= 0 ||
          list_of_size->count() > list_of_size->coal_desired();
 }
+#endif  // SERIALGC
 
 // Closures for walking the binary tree.
 //   do_list() walks the free list in a node applying the closure
@@ -899,19 +926,18 @@
 //   do_tree() walks the nodes in the binary tree applying do_list()
 //     to each list at each node.
 
-template <class Chunk>
+template <class Chunk_t, template <class> class FreeList_t>
 class TreeCensusClosure : public StackObj {
  protected:
-  virtual void do_list(FreeList<Chunk>* fl) = 0;
+  virtual void do_list(FreeList_t<Chunk_t>* fl) = 0;
  public:
-  virtual void do_tree(TreeList<Chunk>* tl) = 0;
+  virtual void do_tree(TreeList<Chunk_t, FreeList_t>* tl) = 0;
 };
 
-template <class Chunk>
-class AscendTreeCensusClosure : public TreeCensusClosure<Chunk> {
-  using TreeCensusClosure<Chunk>::do_list;
+template <class Chunk_t, template <class> class FreeList_t>
+class AscendTreeCensusClosure : public TreeCensusClosure<Chunk_t, FreeList_t> {
  public:
-  void do_tree(TreeList<Chunk>* tl) {
+  void do_tree(TreeList<Chunk_t, FreeList_t>* tl) {
     if (tl != NULL) {
       do_tree(tl->left());
       do_list(tl);
@@ -920,11 +946,10 @@
   }
 };
 
-template <class Chunk>
-class DescendTreeCensusClosure : public TreeCensusClosure<Chunk> {
-  using TreeCensusClosure<Chunk>::do_list;
+template <class Chunk_t, template <class> class FreeList_t>
+class DescendTreeCensusClosure : public TreeCensusClosure<Chunk_t, FreeList_t> {
  public:
-  void do_tree(TreeList<Chunk>* tl) {
+  void do_tree(TreeList<Chunk_t, FreeList_t>* tl) {
     if (tl != NULL) {
       do_tree(tl->right());
       do_list(tl);
@@ -935,8 +960,8 @@
 
 // For each list in the tree, calculate the desired, desired
 // coalesce, count before sweep, and surplus before sweep.
-template <class Chunk>
-class BeginSweepClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class BeginSweepClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
   double _percentage;
   float _inter_sweep_current;
   float _inter_sweep_estimate;
@@ -951,32 +976,36 @@
    _inter_sweep_estimate(inter_sweep_estimate),
    _intra_sweep_estimate(intra_sweep_estimate) { }
 
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList<Chunk_t>* fl) {}
+
+#ifndef SERIALGC
+  void do_list(AdaptiveFreeList<Chunk_t>* fl) {
     double coalSurplusPercent = _percentage;
     fl->compute_desired(_inter_sweep_current, _inter_sweep_estimate, _intra_sweep_estimate);
     fl->set_coal_desired((ssize_t)((double)fl->desired() * coalSurplusPercent));
     fl->set_before_sweep(fl->count());
     fl->set_bfr_surp(fl->surplus());
   }
+#endif // SERIALGC
 };
 
 // Used to search the tree until a condition is met.
 // Similar to TreeCensusClosure but searches the
 // tree and returns promptly when found.
 
-template <class Chunk>
+template <class Chunk_t, template <class> class FreeList_t>
 class TreeSearchClosure : public StackObj {
  protected:
-  virtual bool do_list(FreeList<Chunk>* fl) = 0;
+  virtual bool do_list(FreeList_t<Chunk_t>* fl) = 0;
  public:
-  virtual bool do_tree(TreeList<Chunk>* tl) = 0;
+  virtual bool do_tree(TreeList<Chunk_t, FreeList_t>* tl) = 0;
 };
 
 #if 0 //  Don't need this yet but here for symmetry.
-template <class Chunk>
-class AscendTreeSearchClosure : public TreeSearchClosure {
+template <class Chunk_t, template <class> class FreeList_t>
+class AscendTreeSearchClosure : public TreeSearchClosure<Chunk_t> {
  public:
-  bool do_tree(TreeList<Chunk>* tl) {
+  bool do_tree(TreeList<Chunk_t, FreeList_t>* tl) {
     if (tl != NULL) {
       if (do_tree(tl->left())) return true;
       if (do_list(tl)) return true;
@@ -987,11 +1016,10 @@
 };
 #endif
 
-template <class Chunk>
-class DescendTreeSearchClosure : public TreeSearchClosure<Chunk> {
-  using TreeSearchClosure<Chunk>::do_list;
+template <class Chunk_t, template <class> class FreeList_t>
+class DescendTreeSearchClosure : public TreeSearchClosure<Chunk_t, FreeList_t> {
  public:
-  bool do_tree(TreeList<Chunk>* tl) {
+  bool do_tree(TreeList<Chunk_t, FreeList_t>* tl) {
     if (tl != NULL) {
       if (do_tree(tl->right())) return true;
       if (do_list(tl)) return true;
@@ -1003,17 +1031,17 @@
 
 // Searches the tree for a chunk that ends at the
 // specified address.
-template <class Chunk>
-class EndTreeSearchClosure : public DescendTreeSearchClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class EndTreeSearchClosure : public DescendTreeSearchClosure<Chunk_t, FreeList_t> {
   HeapWord* _target;
-  Chunk* _found;
+  Chunk_t* _found;
 
  public:
   EndTreeSearchClosure(HeapWord* target) : _target(target), _found(NULL) {}
-  bool do_list(FreeList<Chunk>* fl) {
-    Chunk* item = fl->head();
+  bool do_list(FreeList_t<Chunk_t>* fl) {
+    Chunk_t* item = fl->head();
     while (item != NULL) {
-      if (item->end() == _target) {
+      if (item->end() == (uintptr_t*) _target) {
         _found = item;
         return true;
       }
@@ -1021,22 +1049,22 @@
     }
     return false;
   }
-  Chunk* found() { return _found; }
+  Chunk_t* found() { return _found; }
 };
 
-template <class Chunk>
-Chunk* BinaryTreeDictionary<Chunk>::find_chunk_ends_at(HeapWord* target) const {
-  EndTreeSearchClosure<Chunk> etsc(target);
+template <class Chunk_t, template <class> class FreeList_t>
+Chunk_t* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_chunk_ends_at(HeapWord* target) const {
+  EndTreeSearchClosure<Chunk_t, FreeList_t> etsc(target);
   bool found_target = etsc.do_tree(root());
   assert(found_target || etsc.found() == NULL, "Consistency check");
   assert(!found_target || etsc.found() != NULL, "Consistency check");
   return etsc.found();
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::begin_sweep_dict_census(double coalSurplusPercent,
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::begin_sweep_dict_census(double coalSurplusPercent,
   float inter_sweep_current, float inter_sweep_estimate, float intra_sweep_estimate) {
-  BeginSweepClosure<Chunk> bsc(coalSurplusPercent, inter_sweep_current,
+  BeginSweepClosure<Chunk_t, FreeList_t> bsc(coalSurplusPercent, inter_sweep_current,
                                             inter_sweep_estimate,
                                             intra_sweep_estimate);
   bsc.do_tree(root());
@@ -1045,84 +1073,91 @@
 // Closures and methods for calculating total bytes returned to the
 // free lists in the tree.
 #ifndef PRODUCT
-template <class Chunk>
-class InitializeDictReturnedBytesClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class InitializeDictReturnedBytesClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
    public:
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList_t<Chunk_t>* fl) {
     fl->set_returned_bytes(0);
   }
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::initialize_dict_returned_bytes() {
-  InitializeDictReturnedBytesClosure<Chunk> idrb;
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::initialize_dict_returned_bytes() {
+  InitializeDictReturnedBytesClosure<Chunk_t, FreeList_t> idrb;
   idrb.do_tree(root());
 }
 
-template <class Chunk>
-class ReturnedBytesClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class ReturnedBytesClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
   size_t _dict_returned_bytes;
  public:
   ReturnedBytesClosure() { _dict_returned_bytes = 0; }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList_t<Chunk_t>* fl) {
     _dict_returned_bytes += fl->returned_bytes();
   }
   size_t dict_returned_bytes() { return _dict_returned_bytes; }
 };
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::sum_dict_returned_bytes() {
-  ReturnedBytesClosure<Chunk> rbc;
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::sum_dict_returned_bytes() {
+  ReturnedBytesClosure<Chunk_t, FreeList_t> rbc;
   rbc.do_tree(root());
 
   return rbc.dict_returned_bytes();
 }
 
 // Count the number of entries in the tree.
-template <class Chunk>
-class treeCountClosure : public DescendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class treeCountClosure : public DescendTreeCensusClosure<Chunk_t, FreeList_t> {
  public:
   uint count;
   treeCountClosure(uint c) { count = c; }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList_t<Chunk_t>* fl) {
     count++;
   }
 };
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::total_count() {
-  treeCountClosure<Chunk> ctc(0);
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_count() {
+  treeCountClosure<Chunk_t, FreeList_t> ctc(0);
   ctc.do_tree(root());
   return ctc.count;
 }
 #endif // PRODUCT
 
 // Calculate surpluses for the lists in the tree.
-template <class Chunk>
-class setTreeSurplusClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class setTreeSurplusClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
   double percentage;
  public:
   setTreeSurplusClosure(double v) { percentage = v; }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList<Chunk_t>* fl) {}
+
+#ifndef SERIALGC
+  void do_list(AdaptiveFreeList<Chunk_t>* fl) {
     double splitSurplusPercent = percentage;
     fl->set_surplus(fl->count() -
                    (ssize_t)((double)fl->desired() * splitSurplusPercent));
   }
+#endif // SERIALGC
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::set_tree_surplus(double splitSurplusPercent) {
-  setTreeSurplusClosure<Chunk> sts(splitSurplusPercent);
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::set_tree_surplus(double splitSurplusPercent) {
+  setTreeSurplusClosure<Chunk_t, FreeList_t> sts(splitSurplusPercent);
   sts.do_tree(root());
 }
 
 // Set hints for the lists in the tree.
-template <class Chunk>
-class setTreeHintsClosure : public DescendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class setTreeHintsClosure : public DescendTreeCensusClosure<Chunk_t, FreeList_t> {
   size_t hint;
  public:
   setTreeHintsClosure(size_t v) { hint = v; }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList<Chunk_t>* fl) {}
+
+#ifndef SERIALGC
+  void do_list(AdaptiveFreeList<Chunk_t>* fl) {
     fl->set_hint(hint);
     assert(fl->hint() == 0 || fl->hint() > fl->size(),
       "Current hint is inconsistent");
@@ -1130,35 +1165,40 @@
       hint = fl->size();
     }
   }
+#endif // SERIALGC
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::set_tree_hints(void) {
-  setTreeHintsClosure<Chunk> sth(0);
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::set_tree_hints(void) {
+  setTreeHintsClosure<Chunk_t, FreeList_t> sth(0);
   sth.do_tree(root());
 }
 
 // Save count before previous sweep and splits and coalesces.
-template <class Chunk>
-class clearTreeCensusClosure : public AscendTreeCensusClosure<Chunk> {
-  void do_list(FreeList<Chunk>* fl) {
+template <class Chunk_t, template <class> class FreeList_t>
+class clearTreeCensusClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
+  void do_list(FreeList<Chunk_t>* fl) {}
+
+#ifndef SERIALGC
+  void do_list(AdaptiveFreeList<Chunk_t>* fl) {
     fl->set_prev_sweep(fl->count());
     fl->set_coal_births(0);
     fl->set_coal_deaths(0);
     fl->set_split_births(0);
     fl->set_split_deaths(0);
   }
+#endif  // SERIALGC
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::clear_tree_census(void) {
-  clearTreeCensusClosure<Chunk> ctc;
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::clear_tree_census(void) {
+  clearTreeCensusClosure<Chunk_t, FreeList_t> ctc;
   ctc.do_tree(root());
 }
 
 // Do reporting and post sweep clean up.
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::end_sweep_dict_census(double splitSurplusPercent) {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::end_sweep_dict_census(double splitSurplusPercent) {
   // Does walking the tree 3 times hurt?
   set_tree_surplus(splitSurplusPercent);
   set_tree_hints();
@@ -1169,9 +1209,9 @@
 }
 
 // Print summary statistics
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::report_statistics() const {
-  FreeBlockDictionary<Chunk>::verify_par_locked();
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::report_statistics() const {
+  FreeBlockDictionary<Chunk_t>::verify_par_locked();
   gclog_or_tty->print("Statistics for BinaryTreeDictionary:\n"
          "------------------------------------\n");
   size_t total_size = total_chunk_size(debug_only(NULL));
@@ -1182,36 +1222,47 @@
   if (free_blocks > 0) {
     gclog_or_tty->print("Av.  Block  Size: %d\n", total_size/free_blocks);
   }
-  gclog_or_tty->print("Tree      Height: %d\n", treeHeight());
+  gclog_or_tty->print("Tree      Height: %d\n", tree_height());
 }
 
 // Print census information - counts, births, deaths, etc.
 // for each list in the tree.  Also print some summary
 // information.
-template <class Chunk>
-class PrintTreeCensusClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class PrintTreeCensusClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
   int _print_line;
   size_t _total_free;
-  FreeList<Chunk> _total;
+  FreeList_t<Chunk_t> _total;
 
  public:
   PrintTreeCensusClosure() {
     _print_line = 0;
     _total_free = 0;
   }
-  FreeList<Chunk>* total() { return &_total; }
+  FreeList_t<Chunk_t>* total() { return &_total; }
   size_t total_free() { return _total_free; }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList<Chunk_t>* fl) {
     if (++_print_line >= 40) {
-      FreeList<Chunk>::print_labels_on(gclog_or_tty, "size");
+      FreeList_t<Chunk_t>::print_labels_on(gclog_or_tty, "size");
       _print_line = 0;
     }
     fl->print_on(gclog_or_tty);
     _total_free +=            fl->count()            * fl->size()        ;
     total()->set_count(      total()->count()       + fl->count()      );
-    total()->set_bfr_surp(    total()->bfr_surp()     + fl->bfr_surp()    );
+  }
+
+#ifndef SERIALGC
+  void do_list(AdaptiveFreeList<Chunk_t>* fl) {
+    if (++_print_line >= 40) {
+      FreeList_t<Chunk_t>::print_labels_on(gclog_or_tty, "size");
+      _print_line = 0;
+    }
+    fl->print_on(gclog_or_tty);
+    _total_free +=           fl->count()             * fl->size()        ;
+    total()->set_count(      total()->count()        + fl->count()      );
+    total()->set_bfr_surp(   total()->bfr_surp()     + fl->bfr_surp()    );
     total()->set_surplus(    total()->split_deaths() + fl->surplus()    );
-    total()->set_desired(    total()->desired()     + fl->desired()    );
+    total()->set_desired(    total()->desired()      + fl->desired()    );
     total()->set_prev_sweep(  total()->prev_sweep()   + fl->prev_sweep()  );
     total()->set_before_sweep(total()->before_sweep() + fl->before_sweep());
     total()->set_coal_births( total()->coal_births()  + fl->coal_births() );
@@ -1219,18 +1270,32 @@
     total()->set_split_births(total()->split_births() + fl->split_births());
     total()->set_split_deaths(total()->split_deaths() + fl->split_deaths());
   }
+#endif  // SERIALGC
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::print_dict_census(void) const {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::print_dict_census(void) const {
 
   gclog_or_tty->print("\nBinaryTree\n");
-  FreeList<Chunk>::print_labels_on(gclog_or_tty, "size");
-  PrintTreeCensusClosure<Chunk> ptc;
+  FreeList_t<Chunk_t>::print_labels_on(gclog_or_tty, "size");
+  PrintTreeCensusClosure<Chunk_t, FreeList_t> ptc;
   ptc.do_tree(root());
 
-  FreeList<Chunk>* total = ptc.total();
-  FreeList<Chunk>::print_labels_on(gclog_or_tty, " ");
+  FreeList_t<Chunk_t>* total = ptc.total();
+  FreeList_t<Chunk_t>::print_labels_on(gclog_or_tty, " ");
+}
+
+#ifndef SERIALGC
+template <>
+void BinaryTreeDictionary<FreeChunk, AdaptiveFreeList>::print_dict_census(void) const {
+
+  gclog_or_tty->print("\nBinaryTree\n");
+  AdaptiveFreeList<FreeChunk>::print_labels_on(gclog_or_tty, "size");
+  PrintTreeCensusClosure<FreeChunk, AdaptiveFreeList> ptc;
+  ptc.do_tree(root());
+
+  AdaptiveFreeList<FreeChunk>* total = ptc.total();
+  AdaptiveFreeList<FreeChunk>::print_labels_on(gclog_or_tty, " ");
   total->print_on(gclog_or_tty, "TOTAL\t");
   gclog_or_tty->print(
               "total_free(words): " SIZE_FORMAT_W(16)
@@ -1242,9 +1307,10 @@
              (double)(total->desired() - total->count())
              /(total->desired() != 0 ? (double)total->desired() : 1.0));
 }
+#endif  // SERIALGC
 
-template <class Chunk>
-class PrintFreeListsClosure : public AscendTreeCensusClosure<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class PrintFreeListsClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
   outputStream* _st;
   int _print_line;
 
@@ -1253,14 +1319,14 @@
     _st = st;
     _print_line = 0;
   }
-  void do_list(FreeList<Chunk>* fl) {
+  void do_list(FreeList_t<Chunk_t>* fl) {
     if (++_print_line >= 40) {
-      FreeList<Chunk>::print_labels_on(_st, "size");
+      FreeList_t<Chunk_t>::print_labels_on(_st, "size");
       _print_line = 0;
     }
     fl->print_on(gclog_or_tty);
     size_t sz = fl->size();
-    for (Chunk* fc = fl->head(); fc != NULL;
+    for (Chunk_t* fc = fl->head(); fc != NULL;
          fc = fc->next()) {
       _st->print_cr("\t[" PTR_FORMAT "," PTR_FORMAT ")  %s",
                     fc, (HeapWord*)fc + sz,
@@ -1269,11 +1335,11 @@
   }
 };
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::print_free_lists(outputStream* st) const {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::print_free_lists(outputStream* st) const {
 
-  FreeList<Chunk>::print_labels_on(st, "size");
-  PrintFreeListsClosure<Chunk> pflc(st);
+  FreeList_t<Chunk_t>::print_labels_on(st, "size");
+  PrintFreeListsClosure<Chunk_t, FreeList_t> pflc(st);
   pflc.do_tree(root());
 }
 
@@ -1281,18 +1347,18 @@
 // . _root has no parent
 // . parent and child point to each other
 // . each node's key correctly related to that of its child(ren)
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::verify_tree() const {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_tree() const {
   guarantee(root() == NULL || total_free_blocks() == 0 ||
     total_size() != 0, "_total_size should't be 0?");
   guarantee(root() == NULL || root()->parent() == NULL, "_root shouldn't have parent");
   verify_tree_helper(root());
 }
 
-template <class Chunk>
-size_t BinaryTreeDictionary<Chunk>::verify_prev_free_ptrs(TreeList<Chunk>* tl) {
+template <class Chunk_t, template <class> class FreeList_t>
+size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_prev_free_ptrs(TreeList<Chunk_t, FreeList_t>* tl) {
   size_t ct = 0;
-  for (Chunk* curFC = tl->head(); curFC != NULL; curFC = curFC->next()) {
+  for (Chunk_t* curFC = tl->head(); curFC != NULL; curFC = curFC->next()) {
     ct++;
     assert(curFC->prev() == NULL || curFC->prev()->is_free(),
       "Chunk should be free");
@@ -1303,8 +1369,8 @@
 // Note: this helper is recursive rather than iterative, so use with
 // caution on very deep trees; and watch out for stack overflow errors;
 // In general, to be used only for debugging.
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::verify_tree_helper(TreeList<Chunk>* tl) const {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_tree_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
   if (tl == NULL)
     return;
   guarantee(tl->size() != 0, "A list must has a size");
@@ -1332,15 +1398,25 @@
   verify_tree_helper(tl->right());
 }
 
-template <class Chunk>
-void BinaryTreeDictionary<Chunk>::verify() const {
+template <class Chunk_t, template <class> class FreeList_t>
+void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify() const {
   verify_tree();
   guarantee(total_size() == total_size_in_tree(root()), "Total Size inconsistency");
 }
 
+template class TreeList<Metablock, FreeList>;
+template class BinaryTreeDictionary<Metablock, FreeList>;
+template class TreeChunk<Metablock, FreeList>;
+
+template class TreeList<Metachunk, FreeList>;
+template class BinaryTreeDictionary<Metachunk, FreeList>;
+template class TreeChunk<Metachunk, FreeList>;
+
+
 #ifndef SERIALGC
 // Explicitly instantiate these types for FreeChunk.
-template class BinaryTreeDictionary<FreeChunk>;
-template class TreeChunk<FreeChunk>;
-template class TreeList<FreeChunk>;
+template class TreeList<FreeChunk, AdaptiveFreeList>;
+template class BinaryTreeDictionary<FreeChunk, AdaptiveFreeList>;
+template class TreeChunk<FreeChunk, AdaptiveFreeList>;
+
 #endif // SERIALGC
--- a/src/share/vm/memory/binaryTreeDictionary.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/binaryTreeDictionary.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -37,77 +37,78 @@
 // A TreeList is a FreeList which can be used to maintain a
 // binary tree of free lists.
 
-template <class Chunk> class TreeChunk;
-template <class Chunk> class BinaryTreeDictionary;
-template <class Chunk> class AscendTreeCensusClosure;
-template <class Chunk> class DescendTreeCensusClosure;
-template <class Chunk> class DescendTreeSearchClosure;
+template <class Chunk_t, template <class> class FreeList_t> class TreeChunk;
+template <class Chunk_t, template <class> class FreeList_t> class BinaryTreeDictionary;
+template <class Chunk_t, template <class> class FreeList_t> class AscendTreeCensusClosure;
+template <class Chunk_t, template <class> class FreeList_t> class DescendTreeCensusClosure;
+template <class Chunk_t, template <class> class FreeList_t> class DescendTreeSearchClosure;
 
-template <class Chunk>
-class TreeList: public FreeList<Chunk> {
-  friend class TreeChunk<Chunk>;
-  friend class BinaryTreeDictionary<Chunk>;
-  friend class AscendTreeCensusClosure<Chunk>;
-  friend class DescendTreeCensusClosure<Chunk>;
-  friend class DescendTreeSearchClosure<Chunk>;
+template <class Chunk_t, template <class> class FreeList_t>
+class TreeList : public FreeList_t<Chunk_t> {
+  friend class TreeChunk<Chunk_t, FreeList_t>;
+  friend class BinaryTreeDictionary<Chunk_t, FreeList_t>;
+  friend class AscendTreeCensusClosure<Chunk_t, FreeList_t>;
+  friend class DescendTreeCensusClosure<Chunk_t, FreeList_t>;
+  friend class DescendTreeSearchClosure<Chunk_t, FreeList_t>;
 
-  TreeList<Chunk>* _parent;
-  TreeList<Chunk>* _left;
-  TreeList<Chunk>* _right;
+  TreeList<Chunk_t, FreeList_t>* _parent;
+  TreeList<Chunk_t, FreeList_t>* _left;
+  TreeList<Chunk_t, FreeList_t>* _right;
 
  protected:
-  TreeList<Chunk>* parent() const { return _parent; }
-  TreeList<Chunk>* left()   const { return _left;   }
-  TreeList<Chunk>* right()  const { return _right;  }
 
-  // Explicitly import these names into our namespace to fix name lookup with templates
-  using FreeList<Chunk>::head;
-  using FreeList<Chunk>::set_head;
+  TreeList<Chunk_t, FreeList_t>* parent() const { return _parent; }
+  TreeList<Chunk_t, FreeList_t>* left()   const { return _left;   }
+  TreeList<Chunk_t, FreeList_t>* right()  const { return _right;  }
 
-  using FreeList<Chunk>::tail;
-  using FreeList<Chunk>::set_tail;
-  using FreeList<Chunk>::link_tail;
+  // Wrapper on call to base class, to get the template to compile.
+  Chunk_t* head() const { return FreeList_t<Chunk_t>::head(); }
+  Chunk_t* tail() const { return FreeList_t<Chunk_t>::tail(); }
+  void set_head(Chunk_t* head) { FreeList_t<Chunk_t>::set_head(head); }
+  void set_tail(Chunk_t* tail) { FreeList_t<Chunk_t>::set_tail(tail); }
 
-  using FreeList<Chunk>::increment_count;
-  NOT_PRODUCT(using FreeList<Chunk>::increment_returned_bytes_by;)
-  using FreeList<Chunk>::verify_chunk_in_free_list;
-  using FreeList<Chunk>::size;
+  size_t size() const { return FreeList_t<Chunk_t>::size(); }
 
   // Accessors for links in tree.
 
-  void set_left(TreeList<Chunk>* tl) {
+  void set_left(TreeList<Chunk_t, FreeList_t>* tl) {
     _left   = tl;
     if (tl != NULL)
       tl->set_parent(this);
   }
-  void set_right(TreeList<Chunk>* tl) {
+  void set_right(TreeList<Chunk_t, FreeList_t>* tl) {
     _right  = tl;
     if (tl != NULL)
       tl->set_parent(this);
   }
-  void set_parent(TreeList<Chunk>* tl)  { _parent = tl;   }
+  void set_parent(TreeList<Chunk_t, FreeList_t>* tl)  { _parent = tl;   }
 
-  void clearLeft()               { _left = NULL;   }
+  void clear_left()               { _left = NULL;   }
   void clear_right()              { _right = NULL;  }
   void clear_parent()             { _parent = NULL; }
-  void initialize()              { clearLeft(); clear_right(), clear_parent(); }
+  void initialize()               { clear_left(); clear_right(), clear_parent(); FreeList_t<Chunk_t>::initialize(); }
 
   // For constructing a TreeList from a Tree chunk or
   // address and size.
-  static TreeList<Chunk>* as_TreeList(TreeChunk<Chunk>* tc);
-  static TreeList<Chunk>* as_TreeList(HeapWord* addr, size_t size);
+  TreeList();
+  static TreeList<Chunk_t, FreeList_t>*
+          as_TreeList(TreeChunk<Chunk_t, FreeList_t>* tc);
+  static TreeList<Chunk_t, FreeList_t>* as_TreeList(HeapWord* addr, size_t size);
 
   // Returns the head of the free list as a pointer to a TreeChunk.
-  TreeChunk<Chunk>* head_as_TreeChunk();
+  TreeChunk<Chunk_t, FreeList_t>* head_as_TreeChunk();
 
   // Returns the first available chunk in the free list as a pointer
   // to a TreeChunk.
-  TreeChunk<Chunk>* first_available();
+  TreeChunk<Chunk_t, FreeList_t>* first_available();
 
   // Returns the block with the largest heap address amongst
   // those in the list for this size; potentially slow and expensive,
   // use with caution!
-  TreeChunk<Chunk>* largest_address();
+  TreeChunk<Chunk_t, FreeList_t>* largest_address();
+
+  TreeList<Chunk_t, FreeList_t>* get_better_list(
+    BinaryTreeDictionary<Chunk_t, FreeList_t>* dictionary);
 
   // remove_chunk_replace_if_needed() removes the given "tc" from the TreeList.
   // If "tc" is the first chunk in the list, it is also the
@@ -115,10 +116,10 @@
   // returns the possibly replaced TreeList* for the node in
   // the tree.  It also updates the parent of the original
   // node to point to the new node.
-  TreeList<Chunk>* remove_chunk_replace_if_needed(TreeChunk<Chunk>* tc);
+  TreeList<Chunk_t, FreeList_t>* remove_chunk_replace_if_needed(TreeChunk<Chunk_t, FreeList_t>* tc);
   // See FreeList.
-  void return_chunk_at_head(TreeChunk<Chunk>* tc);
-  void return_chunk_at_tail(TreeChunk<Chunk>* tc);
+  void return_chunk_at_head(TreeChunk<Chunk_t, FreeList_t>* tc);
+  void return_chunk_at_tail(TreeChunk<Chunk_t, FreeList_t>* tc);
 };
 
 // A TreeChunk is a subclass of a Chunk that additionally
@@ -134,52 +135,54 @@
 // on the free list for a node in the tree and is only removed if
 // it is the last chunk on the free list.
 
-template <class Chunk>
-class TreeChunk : public Chunk {
-  friend class TreeList<Chunk>;
-  TreeList<Chunk>* _list;
-  TreeList<Chunk> _embedded_list;  // if non-null, this chunk is on _list
+template <class Chunk_t, template <class> class FreeList_t>
+class TreeChunk : public Chunk_t {
+  friend class TreeList<Chunk_t, FreeList_t>;
+  TreeList<Chunk_t, FreeList_t>* _list;
+  TreeList<Chunk_t, FreeList_t> _embedded_list;  // if non-null, this chunk is on _list
+
+  static size_t _min_tree_chunk_size;
+
  protected:
-  TreeList<Chunk>* embedded_list() const { return (TreeList<Chunk>*) &_embedded_list; }
-  void set_embedded_list(TreeList<Chunk>* v) { _embedded_list = *v; }
+  TreeList<Chunk_t, FreeList_t>* embedded_list() const { return (TreeList<Chunk_t, FreeList_t>*) &_embedded_list; }
+  void set_embedded_list(TreeList<Chunk_t, FreeList_t>* v) { _embedded_list = *v; }
  public:
-  TreeList<Chunk>* list() { return _list; }
-  void set_list(TreeList<Chunk>* v) { _list = v; }
-  static TreeChunk<Chunk>* as_TreeChunk(Chunk* fc);
+  TreeList<Chunk_t, FreeList_t>* list() { return _list; }
+  void set_list(TreeList<Chunk_t, FreeList_t>* v) { _list = v; }
+  static TreeChunk<Chunk_t, FreeList_t>* as_TreeChunk(Chunk_t* fc);
   // Initialize fields in a TreeChunk that should be
   // initialized when the TreeChunk is being added to
   // a free list in the tree.
   void initialize() { embedded_list()->initialize(); }
 
-  Chunk* next() const { return Chunk::next(); }
-  Chunk* prev() const { return Chunk::prev(); }
-  size_t size() const volatile { return Chunk::size(); }
+  Chunk_t* next() const { return Chunk_t::next(); }
+  Chunk_t* prev() const { return Chunk_t::prev(); }
+  size_t size() const volatile { return Chunk_t::size(); }
+
+  static size_t min_size() {
+    return _min_tree_chunk_size;
+  }
 
   // debugging
   void verify_tree_chunk_list() const;
+  void assert_is_mangled() const;
 };
 
 
-template <class Chunk>
-class BinaryTreeDictionary: public FreeBlockDictionary<Chunk> {
+template <class Chunk_t, template <class> class FreeList_t>
+class BinaryTreeDictionary: public FreeBlockDictionary<Chunk_t> {
   friend class VMStructs;
-  bool       _splay;
-  bool       _adaptive_freelists;
   size_t     _total_size;
   size_t     _total_free_blocks;
-  TreeList<Chunk>* _root;
+  TreeList<Chunk_t, FreeList_t>* _root;
 
   // private accessors
-  bool splay() const { return _splay; }
-  void set_splay(bool v) { _splay = v; }
   void set_total_size(size_t v) { _total_size = v; }
   virtual void inc_total_size(size_t v);
   virtual void dec_total_size(size_t v);
-  size_t total_free_blocks() const { return _total_free_blocks; }
   void set_total_free_blocks(size_t v) { _total_free_blocks = v; }
-  TreeList<Chunk>* root() const { return _root; }
-  void set_root(TreeList<Chunk>* v) { _root = v; }
-  bool adaptive_freelists() { return _adaptive_freelists; }
+  TreeList<Chunk_t, FreeList_t>* root() const { return _root; }
+  void set_root(TreeList<Chunk_t, FreeList_t>* v) { _root = v; }
 
   // This field is added and can be set to point to the
   // the Mutex used to synchronize access to the
@@ -191,54 +194,55 @@
   // return it.  If the chunk
   // is the last chunk of that size, remove the node for that size
   // from the tree.
-  TreeChunk<Chunk>* get_chunk_from_tree(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither, bool splay);
+  TreeChunk<Chunk_t, FreeList_t>* get_chunk_from_tree(size_t size, enum FreeBlockDictionary<Chunk_t>::Dither dither);
+  // Remove this chunk from the tree.  If the removal results
+  // in an empty list in the tree, remove the empty list.
+  TreeChunk<Chunk_t, FreeList_t>* remove_chunk_from_tree(TreeChunk<Chunk_t, FreeList_t>* tc);
+  // Remove the node in the trees starting at tl that has the
+  // minimum value and return it.  Repair the tree as needed.
+  TreeList<Chunk_t, FreeList_t>* remove_tree_minimum(TreeList<Chunk_t, FreeList_t>* tl);
+  // Add this free chunk to the tree.
+  void       insert_chunk_in_tree(Chunk_t* freeChunk);
+ public:
+
   // Return a list of the specified size or NULL from the tree.
   // The list is not removed from the tree.
-  TreeList<Chunk>* find_list (size_t size) const;
-  // Remove this chunk from the tree.  If the removal results
-  // in an empty list in the tree, remove the empty list.
-  TreeChunk<Chunk>* remove_chunk_from_tree(TreeChunk<Chunk>* tc);
-  // Remove the node in the trees starting at tl that has the
-  // minimum value and return it.  Repair the tree as needed.
-  TreeList<Chunk>* remove_tree_minimum(TreeList<Chunk>* tl);
-  void       semi_splay_step(TreeList<Chunk>* tl);
-  // Add this free chunk to the tree.
-  void       insert_chunk_in_tree(Chunk* freeChunk);
- public:
-
-  static const size_t min_tree_chunk_size  = sizeof(TreeChunk<Chunk>)/HeapWordSize;
+  TreeList<Chunk_t, FreeList_t>* find_list (size_t size) const;
 
   void       verify_tree() const;
   // verify that the given chunk is in the tree.
-  bool       verify_chunk_in_free_list(Chunk* tc) const;
+  bool       verify_chunk_in_free_list(Chunk_t* tc) const;
  private:
-  void          verify_tree_helper(TreeList<Chunk>* tl) const;
-  static size_t verify_prev_free_ptrs(TreeList<Chunk>* tl);
+  void          verify_tree_helper(TreeList<Chunk_t, FreeList_t>* tl) const;
+  static size_t verify_prev_free_ptrs(TreeList<Chunk_t, FreeList_t>* tl);
 
   // Returns the total number of chunks in the list.
-  size_t     total_list_length(TreeList<Chunk>* tl) const;
+  size_t     total_list_length(TreeList<Chunk_t, FreeList_t>* tl) const;
   // Returns the total number of words in the chunks in the tree
   // starting at "tl".
-  size_t     total_size_in_tree(TreeList<Chunk>* tl) const;
+  size_t     total_size_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const;
   // Returns the sum of the square of the size of each block
   // in the tree starting at "tl".
-  double     sum_of_squared_block_sizes(TreeList<Chunk>* const tl) const;
+  double     sum_of_squared_block_sizes(TreeList<Chunk_t, FreeList_t>* const tl) const;
   // Returns the total number of free blocks in the tree starting
   // at "tl".
-  size_t     total_free_blocks_in_tree(TreeList<Chunk>* tl) const;
-  size_t     num_free_blocks() const;
-  size_t     treeHeight() const;
-  size_t     tree_height_helper(TreeList<Chunk>* tl) const;
-  size_t     total_nodes_in_tree(TreeList<Chunk>* tl) const;
-  size_t     total_nodes_helper(TreeList<Chunk>* tl) const;
+  size_t     total_free_blocks_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const;
+  size_t     num_free_blocks()  const;
+  size_t     tree_height() const;
+  size_t     tree_height_helper(TreeList<Chunk_t, FreeList_t>* tl) const;
+  size_t     total_nodes_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const;
+  size_t     total_nodes_helper(TreeList<Chunk_t, FreeList_t>* tl) const;
 
  public:
   // Constructor
-  BinaryTreeDictionary(bool adaptive_freelists, bool splay = false);
-  BinaryTreeDictionary(MemRegion mr, bool adaptive_freelists, bool splay = false);
+  BinaryTreeDictionary() :
+    _total_size(0), _total_free_blocks(0), _root(0) {}
+
+  BinaryTreeDictionary(MemRegion mr);
 
   // Public accessors
   size_t total_size() const { return _total_size; }
+  size_t total_free_blocks() const { return _total_free_blocks; }
 
   // Reset the dictionary to the initial conditions with
   // a single free chunk.
@@ -249,23 +253,24 @@
 
   // Return a chunk of size "size" or greater from
   // the tree.
-  // want a better dynamic splay strategy for the future.
-  Chunk* get_chunk(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither) {
-    FreeBlockDictionary<Chunk>::verify_par_locked();
-    Chunk* res = get_chunk_from_tree(size, dither, splay());
+  Chunk_t* get_chunk(size_t size, enum FreeBlockDictionary<Chunk_t>::Dither dither) {
+    FreeBlockDictionary<Chunk_t>::verify_par_locked();
+    Chunk_t* res = get_chunk_from_tree(size, dither);
     assert(res == NULL || res->is_free(),
            "Should be returning a free chunk");
+    assert(dither != FreeBlockDictionary<Chunk_t>::exactly ||
+           res->size() == size, "Not correct size");
     return res;
   }
 
-  void return_chunk(Chunk* chunk) {
-    FreeBlockDictionary<Chunk>::verify_par_locked();
+  void return_chunk(Chunk_t* chunk) {
+    FreeBlockDictionary<Chunk_t>::verify_par_locked();
     insert_chunk_in_tree(chunk);
   }
 
-  void remove_chunk(Chunk* chunk) {
-    FreeBlockDictionary<Chunk>::verify_par_locked();
-    remove_chunk_from_tree((TreeChunk<Chunk>*)chunk);
+  void remove_chunk(Chunk_t* chunk) {
+    FreeBlockDictionary<Chunk_t>::verify_par_locked();
+    remove_chunk_from_tree((TreeChunk<Chunk_t, FreeList_t>*)chunk);
     assert(chunk->is_free(), "Should still be a free chunk");
   }
 
@@ -281,19 +286,19 @@
   }
 
   size_t     min_size() const {
-    return min_tree_chunk_size;
+    return TreeChunk<Chunk_t, FreeList_t>::min_size();
   }
 
   double     sum_of_squared_block_sizes() const {
     return sum_of_squared_block_sizes(root());
   }
 
-  Chunk* find_chunk_ends_at(HeapWord* target) const;
+  Chunk_t* find_chunk_ends_at(HeapWord* target) const;
 
   // Find the list with size "size" in the binary tree and update
   // the statistics in the list according to "split" (chunk was
   // split or coalesce) and "birth" (chunk was added or removed).
-  void       dict_census_udpate(size_t size, bool split, bool birth);
+  void       dict_census_update(size_t size, bool split, bool birth);
   // Return true if the dictionary is overpopulated (more chunks of
   // this size than desired) for size "size".
   bool       coal_dict_over_populated(size_t size);
@@ -307,7 +312,7 @@
   // statistics for the sweep.
   void       end_sweep_dict_census(double splitSurplusPercent);
   // Return the largest free chunk in the tree.
-  Chunk* find_largest_dict() const;
+  Chunk_t* find_largest_dict() const;
   // Accessors for statistics
   void       set_tree_surplus(double splitSurplusPercent);
   void       set_tree_hints(void);
--- a/src/share/vm/memory/freeBlockDictionary.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/freeBlockDictionary.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -27,6 +27,8 @@
 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
 #endif // SERIALGC
 #include "memory/freeBlockDictionary.hpp"
+#include "memory/metablock.hpp"
+#include "memory/metachunk.hpp"
 #ifdef TARGET_OS_FAMILY_linux
 # include "thread_linux.inline.hpp"
 #endif
@@ -62,6 +64,9 @@
 }
 #endif
 
+template class FreeBlockDictionary<Metablock>;
+template class FreeBlockDictionary<Metachunk>;
+
 #ifndef SERIALGC
 // Explicitly instantiate for FreeChunk
 template class FreeBlockDictionary<FreeChunk>;
--- a/src/share/vm/memory/freeBlockDictionary.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/freeBlockDictionary.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -66,7 +66,7 @@
   virtual void       reset(HeapWord* addr, size_t size) = 0;
   virtual void       reset() = 0;
 
-  virtual void       dict_census_udpate(size_t size, bool split, bool birth) = 0;
+  virtual void       dict_census_update(size_t size, bool split, bool birth) = 0;
   virtual bool       coal_dict_over_populated(size_t size) = 0;
   virtual void       begin_sweep_dict_census(double coalSurplusPercent,
                        float inter_sweep_current, float inter_sweep_estimate,
--- a/src/share/vm/memory/freeList.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/freeList.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -25,6 +25,8 @@
 #include "precompiled.hpp"
 #include "memory/freeBlockDictionary.hpp"
 #include "memory/freeList.hpp"
+#include "memory/metablock.hpp"
+#include "memory/metachunk.hpp"
 #include "memory/sharedHeap.hpp"
 #include "runtime/globals.hpp"
 #include "runtime/mutex.hpp"
@@ -49,8 +51,6 @@
 {
   _size         = 0;
   _count        = 0;
-  _hint         = 0;
-  init_statistics();
 }
 
 template <class Chunk>
@@ -62,34 +62,50 @@
 {
   _size         = fc->size();
   _count        = 1;
-  _hint         = 0;
-  init_statistics();
-#ifndef PRODUCT
-  _allocation_stats.set_returned_bytes(size() * HeapWordSize);
-#endif
 }
 
 template <class Chunk>
-void FreeList<Chunk>::reset(size_t hint) {
+void FreeList<Chunk>::link_head(Chunk* v) {
+  assert_proper_lock_protection();
+  set_head(v);
+  // If this method is not used (just set the head instead),
+  // this check can be avoided.
+  if (v != NULL) {
+    v->link_prev(NULL);
+  }
+}
+
+
+
+template <class Chunk>
+void FreeList<Chunk>::reset() {
+  // Don't set the _size to 0 because this method is
+  // used with a existing list that has a size but which has
+  // been emptied.
+  // Don't clear the _protecting_lock of an existing list.
   set_count(0);
   set_head(NULL);
   set_tail(NULL);
-  set_hint(hint);
 }
 
 template <class Chunk>
-void FreeList<Chunk>::init_statistics(bool split_birth) {
-  _allocation_stats.initialize(split_birth);
+void FreeList<Chunk>::initialize() {
+#ifdef ASSERT
+  // Needed early because it might be checked in other initializing code.
+  set_protecting_lock(NULL);
+#endif
+  reset();
+  set_size(0);
 }
 
-template <class Chunk>
-Chunk* FreeList<Chunk>::get_chunk_at_head() {
+template <class Chunk_t>
+Chunk_t* FreeList<Chunk_t>::get_chunk_at_head() {
   assert_proper_lock_protection();
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
-  Chunk* fc = head();
+  Chunk_t* fc = head();
   if (fc != NULL) {
-    Chunk* nextFC = fc->next();
+    Chunk_t* nextFC = fc->next();
     if (nextFC != NULL) {
       // The chunk fc being removed has a "next".  Set the "next" to the
       // "prev" of fc.
@@ -197,11 +213,6 @@
     link_tail(chunk);
   }
   increment_count(); // of # of chunks in list
-  DEBUG_ONLY(
-    if (record_return) {
-      increment_returned_bytes_by(size()*HeapWordSize);
-    }
-  )
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
   assert(head() == NULL || head()->size() == size(), "wrong item on list");
@@ -233,11 +244,6 @@
   }
   link_tail(chunk);
   increment_count();  // of # of chunks in list
-  DEBUG_ONLY(
-    if (record_return) {
-      increment_returned_bytes_by(size()*HeapWordSize);
-    }
-  )
   assert(head() == NULL || head()->prev() == NULL, "list invariant");
   assert(tail() == NULL || tail()->next() == NULL, "list invariant");
   assert(head() == NULL || head()->size() == size(), "wrong item on list");
@@ -273,7 +279,7 @@
   }
 }
 
-// verify_chunk_in_free_list() is used to verify that an item is in this free list.
+// verify_chunk_in_free_lists() is used to verify that an item is in this free list.
 // It is used as a debugging aid.
 template <class Chunk>
 bool FreeList<Chunk>::verify_chunk_in_free_list(Chunk* fc) const {
@@ -294,40 +300,14 @@
 
 #ifndef PRODUCT
 template <class Chunk>
-void FreeList<Chunk>::verify_stats() const {
-  // The +1 of the LH comparand is to allow some "looseness" in
-  // checking: we usually call this interface when adding a block
-  // and we'll subsequently update the stats; we cannot update the
-  // stats beforehand because in the case of the large-block BT
-  // dictionary for example, this might be the first block and
-  // in that case there would be no place that we could record
-  // the stats (which are kept in the block itself).
-  assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births()
-          + _allocation_stats.coal_births() + 1)   // Total Production Stock + 1
-         >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths()
-             + (ssize_t)count()),                // Total Current Stock + depletion
-         err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
-                 " violates Conservation Principle: "
-                 "prev_sweep(" SIZE_FORMAT ")"
-                 " + split_births(" SIZE_FORMAT ")"
-                 " + coal_births(" SIZE_FORMAT ") + 1 >= "
-                 " split_deaths(" SIZE_FORMAT ")"
-                 " coal_deaths(" SIZE_FORMAT ")"
-                 " + count(" SSIZE_FORMAT ")",
-                 this, _size, _allocation_stats.prev_sweep(), _allocation_stats.split_births(),
-                 _allocation_stats.split_births(), _allocation_stats.split_deaths(),
-                 _allocation_stats.coal_deaths(), count()));
-}
-
-template <class Chunk>
 void FreeList<Chunk>::assert_proper_lock_protection_work() const {
-  assert(_protecting_lock != NULL, "Don't call this directly");
+  assert(protecting_lock() != NULL, "Don't call this directly");
   assert(ParallelGCThreads > 0, "Don't call this directly");
   Thread* thr = Thread::current();
   if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) {
     // assert that we are holding the freelist lock
   } else if (thr->is_GC_task_thread()) {
-    assert(_protecting_lock->owned_by_self(), "FreeList RACE DETECTED");
+    assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED");
   } else if (thr->is_Java_thread()) {
     assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing");
   } else {
@@ -350,21 +330,17 @@
 // to the call is a non-null string, it is printed in the first column;
 // otherwise, if the argument is null (the default), then the size of the
 // (free list) block is printed in the first column.
-template <class Chunk>
-void FreeList<Chunk>::print_on(outputStream* st, const char* c) const {
+template <class Chunk_t>
+void FreeList<Chunk_t>::print_on(outputStream* st, const char* c) const {
   if (c != NULL) {
     st->print("%16s", c);
   } else {
     st->print(SIZE_FORMAT_W(16), size());
   }
-  st->print("\t"
-           SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t"
-           SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\n",
-           bfr_surp(),             surplus(),             desired(),             prev_sweep(),           before_sweep(),
-           count(),               coal_births(),          coal_deaths(),          split_births(),         split_deaths());
 }
 
+template class FreeList<Metablock>;
+template class FreeList<Metachunk>;
 #ifndef SERIALGC
-// Needs to be after the definitions have been seen.
 template class FreeList<FreeChunk>;
 #endif // SERIALGC
--- a/src/share/vm/memory/freeList.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/freeList.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -40,23 +40,19 @@
 // for that implementation.
 
 class Mutex;
-template <class Chunk> class TreeList;
-template <class Chunk> class PrintTreeCensusClosure;
 
-template <class Chunk>
+template <class Chunk_t>
 class FreeList VALUE_OBJ_CLASS_SPEC {
   friend class CompactibleFreeListSpace;
   friend class VMStructs;
-  friend class PrintTreeCensusClosure<Chunk>;
 
  private:
-  Chunk*        _head;          // Head of list of free chunks
-  Chunk*        _tail;          // Tail of list of free chunks
+  Chunk_t*      _head;          // Head of list of free chunks
+  Chunk_t*      _tail;          // Tail of list of free chunks
   size_t        _size;          // Size in Heap words of each chunk
   ssize_t       _count;         // Number of entries in list
-  size_t        _hint;          // next larger size list with a positive surplus
 
-  AllocationStats _allocation_stats; // allocation-related statistics
+ protected:
 
 #ifdef ASSERT
   Mutex*        _protecting_lock;
@@ -71,10 +67,6 @@
 #endif
   }
 
-  // Initialize the allocation statistics.
- protected:
-  void init_statistics(bool split_birth = false);
-  void set_count(ssize_t v) { _count = v;}
   void increment_count()    {
     _count++;
   }
@@ -89,52 +81,48 @@
   // Construct a list without any entries.
   FreeList();
   // Construct a list with "fc" as the first (and lone) entry in the list.
-  FreeList(Chunk* fc);
+  FreeList(Chunk_t* fc);
 
-  // Reset the head, tail, hint, and count of a free list.
-  void reset(size_t hint);
+  // Do initialization
+  void initialize();
+
+  // Reset the head, tail, and count of a free list.
+  void reset();
 
   // Declare the current free list to be protected by the given lock.
 #ifdef ASSERT
-  void set_protecting_lock(Mutex* protecting_lock) {
-    _protecting_lock = protecting_lock;
+  Mutex* protecting_lock() const { return _protecting_lock; }
+  void set_protecting_lock(Mutex* v) {
+    _protecting_lock = v;
   }
 #endif
 
   // Accessors.
-  Chunk* head() const {
+  Chunk_t* head() const {
     assert_proper_lock_protection();
     return _head;
   }
-  void set_head(Chunk* v) {
+  void set_head(Chunk_t* v) {
     assert_proper_lock_protection();
     _head = v;
     assert(!_head || _head->size() == _size, "bad chunk size");
   }
   // Set the head of the list and set the prev field of non-null
   // values to NULL.
-  void link_head(Chunk* v) {
-    assert_proper_lock_protection();
-    set_head(v);
-    // If this method is not used (just set the head instead),
-    // this check can be avoided.
-    if (v != NULL) {
-      v->link_prev(NULL);
-    }
-  }
+  void link_head(Chunk_t* v);
 
-  Chunk* tail() const {
+  Chunk_t* tail() const {
     assert_proper_lock_protection();
     return _tail;
   }
-  void set_tail(Chunk* v) {
+  void set_tail(Chunk_t* v) {
     assert_proper_lock_protection();
     _tail = v;
     assert(!_tail || _tail->size() == _size, "bad chunk size");
   }
   // Set the tail of the list and set the next field of non-null
   // values to NULL.
-  void link_tail(Chunk* v) {
+  void link_tail(Chunk_t* v) {
     assert_proper_lock_protection();
     set_tail(v);
     if (v != NULL) {
@@ -152,174 +140,45 @@
     assert_proper_lock_protection();
     _size = v;
   }
-  ssize_t count() const {
-    return _count;
-  }
-  size_t hint() const {
-    return _hint;
-  }
-  void set_hint(size_t v) {
-    assert_proper_lock_protection();
-    assert(v == 0 || _size < v, "Bad hint"); _hint = v;
-  }
+  ssize_t count() const { return _count; }
+  void set_count(ssize_t v) { _count = v;}
 
-  // Accessors for statistics
-  AllocationStats* allocation_stats() {
-    assert_proper_lock_protection();
-    return &_allocation_stats;
-  }
+  size_t get_better_size() { return size(); }
 
-  ssize_t desired() const {
-    return _allocation_stats.desired();
-  }
-  void set_desired(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_desired(v);
-  }
-  void compute_desired(float inter_sweep_current,
-                       float inter_sweep_estimate,
-                       float intra_sweep_estimate) {
-    assert_proper_lock_protection();
-    _allocation_stats.compute_desired(_count,
-                                      inter_sweep_current,
-                                      inter_sweep_estimate,
-                                      intra_sweep_estimate);
-  }
-  ssize_t coal_desired() const {
-    return _allocation_stats.coal_desired();
-  }
-  void set_coal_desired(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_coal_desired(v);
-  }
-
-  ssize_t surplus() const {
-    return _allocation_stats.surplus();
-  }
-  void set_surplus(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_surplus(v);
-  }
-  void increment_surplus() {
-    assert_proper_lock_protection();
-    _allocation_stats.increment_surplus();
-  }
-  void decrement_surplus() {
-    assert_proper_lock_protection();
-    _allocation_stats.decrement_surplus();
-  }
-
-  ssize_t bfr_surp() const {
-    return _allocation_stats.bfr_surp();
-  }
-  void set_bfr_surp(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_bfr_surp(v);
-  }
-  ssize_t prev_sweep() const {
-    return _allocation_stats.prev_sweep();
-  }
-  void set_prev_sweep(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_prev_sweep(v);
-  }
-  ssize_t before_sweep() const {
-    return _allocation_stats.before_sweep();
-  }
-  void set_before_sweep(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_before_sweep(v);
-  }
-
-  ssize_t coal_births() const {
-    return _allocation_stats.coal_births();
-  }
-  void set_coal_births(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_coal_births(v);
-  }
-  void increment_coal_births() {
-    assert_proper_lock_protection();
-    _allocation_stats.increment_coal_births();
-  }
-
-  ssize_t coal_deaths() const {
-    return _allocation_stats.coal_deaths();
-  }
-  void set_coal_deaths(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_coal_deaths(v);
-  }
-  void increment_coal_deaths() {
-    assert_proper_lock_protection();
-    _allocation_stats.increment_coal_deaths();
-  }
-
-  ssize_t split_births() const {
-    return _allocation_stats.split_births();
-  }
-  void set_split_births(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_split_births(v);
-  }
-  void increment_split_births() {
-    assert_proper_lock_protection();
-    _allocation_stats.increment_split_births();
-  }
-
-  ssize_t split_deaths() const {
-    return _allocation_stats.split_deaths();
-  }
-  void set_split_deaths(ssize_t v) {
-    assert_proper_lock_protection();
-    _allocation_stats.set_split_deaths(v);
-  }
-  void increment_split_deaths() {
-    assert_proper_lock_protection();
-    _allocation_stats.increment_split_deaths();
-  }
-
-  NOT_PRODUCT(
-    // For debugging.  The "_returned_bytes" in all the lists are summed
-    // and compared with the total number of bytes swept during a
-    // collection.
-    size_t returned_bytes() const { return _allocation_stats.returned_bytes(); }
-    void set_returned_bytes(size_t v) { _allocation_stats.set_returned_bytes(v); }
-    void increment_returned_bytes_by(size_t v) {
-      _allocation_stats.set_returned_bytes(_allocation_stats.returned_bytes() + v);
-    }
-  )
+  size_t returned_bytes() const { ShouldNotReachHere(); return 0; }
+  void set_returned_bytes(size_t v) {}
+  void increment_returned_bytes_by(size_t v) {}
 
   // Unlink head of list and return it.  Returns NULL if
   // the list is empty.
-  Chunk* get_chunk_at_head();
+  Chunk_t* get_chunk_at_head();
 
   // Remove the first "n" or "count", whichever is smaller, chunks from the
   // list, setting "fl", which is required to be empty, to point to them.
-  void getFirstNChunksFromList(size_t n, FreeList<Chunk>* fl);
+  void getFirstNChunksFromList(size_t n, FreeList<Chunk_t>* fl);
 
   // Unlink this chunk from it's free list
-  void remove_chunk(Chunk* fc);
+  void remove_chunk(Chunk_t* fc);
 
   // Add this chunk to this free list.
-  void return_chunk_at_head(Chunk* fc);
-  void return_chunk_at_tail(Chunk* fc);
+  void return_chunk_at_head(Chunk_t* fc);
+  void return_chunk_at_tail(Chunk_t* fc);
 
   // Similar to returnChunk* but also records some diagnostic
   // information.
-  void return_chunk_at_head(Chunk* fc, bool record_return);
-  void return_chunk_at_tail(Chunk* fc, bool record_return);
+  void return_chunk_at_head(Chunk_t* fc, bool record_return);
+  void return_chunk_at_tail(Chunk_t* fc, bool record_return);
 
   // Prepend "fl" (whose size is required to be the same as that of "this")
   // to the front of "this" list.
-  void prepend(FreeList<Chunk>* fl);
+  void prepend(FreeList<Chunk_t>* fl);
 
   // Verify that the chunk is in the list.
   // found.  Return NULL if "fc" is not found.
-  bool verify_chunk_in_free_list(Chunk* fc) const;
+  bool verify_chunk_in_free_list(Chunk_t* fc) const;
 
   // Stats verification
-  void verify_stats() const PRODUCT_RETURN;
+//  void verify_stats() const { ShouldNotReachHere(); };
 
   // Printing support
   static void print_labels_on(outputStream* st, const char* c);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/metablock.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2012, 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_METABLOCK_HPP
+#define SHARE_VM_MEMORY_METABLOCK_HPP
+
+// Metablock are the unit of allocation from a Chunk.  It is initialized
+// with the size of the requested allocation.  That size is overwritten
+// once the allocation returns.
+//
+// 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 VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+ private:
+  // Used to align the allocation (see below).
+  union block_t {
+    void* _data[3];
+    struct header_t {
+      size_t _word_size;
+      Metablock* _next;
+      Metablock* _prev;
+    } _header;
+  } _block;
+  static size_t _min_block_byte_size;
+  static size_t _overhead;
+
+  typedef union block_t Block;
+  typedef struct header_t Header;
+  const Block* block() const { return &_block; }
+  const Block::header_t* header() const { return &(block()->_header); }
+ public:
+
+  static Metablock* initialize(MetaWord* p, size_t word_size);
+
+  // This places the body of the block at a 2 word boundary
+  // because every block starts on a 2 word boundary.  Work out
+  // how to make the body on a 2 word boundary if the block
+  // starts on a arbitrary boundary.  JJJ
+
+  size_t word_size() const  { return header()->_word_size; }
+  void set_word_size(size_t v) { _block._header._word_size = v; }
+  size_t size() const volatile { return _block._header._word_size; }
+  void set_size(size_t v) { _block._header._word_size = v; }
+  Metablock* next() const { return header()->_next; }
+  void set_next(Metablock* v) { _block._header._next = v; }
+  Metablock* prev() const { return header()->_prev; }
+  void set_prev(Metablock* v) { _block._header._prev = v; }
+
+  static size_t min_block_byte_size() { return _min_block_byte_size; }
+  static size_t overhead() { return _overhead; }
+
+  bool is_free()                 { return header()->_word_size != 0; }
+  void clear_next()              { set_next(NULL); }
+  void link_prev(Metablock* ptr) { set_prev(ptr); }
+  uintptr_t* end()              { return ((uintptr_t*) this) + size(); }
+  bool cantCoalesce() const     { return false; }
+  void link_next(Metablock* ptr) { set_next(ptr); }
+  void link_after(Metablock* ptr){
+    link_next(ptr);
+    if (ptr != NULL) ptr->link_prev(this);
+  }
+
+  // Should not be needed in a free list of Metablocks
+  void markNotFree()            { ShouldNotReachHere(); }
+
+  // Debug support
+#ifdef ASSERT
+  void* prev_addr() const { return (void*)&_block._header._prev; }
+  void* next_addr() const { return (void*)&_block._header._next; }
+  void* size_addr() const { return (void*)&_block._header._word_size; }
+#endif
+  bool verify_chunk_in_free_list(Metablock* tc) const { return true; }
+  bool verify_par_locked() { return true; }
+
+  void assert_is_mangled() const {/* Don't check "\*/}
+};
+#endif // SHARE_VM_MEMORY_METABLOCK_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/metachunk.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2012, 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
+
+//  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     |
+//            |              |            |          |
+//            |              |            |          | capacity
+//            |              |            |          |
+//            |              | <- top   --+          |
+//            |              |           ---+        |
+//            |              |              | used   |
+//            |              |              |        |
+//            |              |              |        |
+//            +--------------+ <- bottom ---+     ---+
+
+class Metachunk VALUE_OBJ_CLASS_SPEC {
+  // link to support lists of chunks
+  Metachunk* _next;
+  Metachunk* _prev;
+
+  MetaWord* _bottom;
+  MetaWord* _end;
+  MetaWord* _top;
+  size_t _word_size;
+  // Used in a guarantee() so included in the Product builds
+  // even through it is only for debugging.
+  bool _is_free;
+
+  // 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.
+  static size_t _overhead;
+
+  void set_bottom(MetaWord* v) { _bottom = v; }
+  void set_end(MetaWord* v) { _end = v; }
+  void set_top(MetaWord* v) { _top = v; }
+  void set_word_size(size_t v) { _word_size = v; }
+ public:
+#ifdef ASSERT
+  Metachunk() : _bottom(NULL), _end(NULL), _top(NULL), _is_free(false) {}
+#else
+  Metachunk() : _bottom(NULL), _end(NULL), _top(NULL) {}
+#endif
+
+  // Used to add a Metachunk to a list of Metachunks
+  void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");}
+  void set_prev(Metachunk* v) { _prev = v; assert(v != this, "Boom");}
+
+  MetaWord* allocate(size_t word_size);
+  static Metachunk* initialize(MetaWord* ptr, size_t word_size);
+
+  // Accessors
+  Metachunk* next() const { return _next; }
+  Metachunk* prev() const { return _prev; }
+  MetaWord* bottom() const { return _bottom; }
+  MetaWord* end() const { return _end; }
+  MetaWord* top() const { return _top; }
+  size_t word_size() const { return _word_size; }
+  size_t size() const volatile { return _word_size; }
+  void set_size(size_t v) { _word_size = v; }
+  bool is_free() { return _is_free; }
+  void set_is_free(bool v) { _is_free = v; }
+  static size_t overhead() { return _overhead; }
+  void clear_next()              { set_next(NULL); }
+  void link_prev(Metachunk* ptr) { set_prev(ptr); }
+  uintptr_t* end()              { return ((uintptr_t*) this) + size(); }
+  bool cantCoalesce() const     { return false; }
+  void link_next(Metachunk* ptr) { set_next(ptr); }
+  void link_after(Metachunk* ptr){
+    link_next(ptr);
+    if (ptr != NULL) ptr->link_prev(this);
+  }
+
+  // Reset top to bottom so chunk can be reused.
+  void reset_empty() { _top = (_bottom + _overhead); }
+  bool is_empty() { return _top == (_bottom + _overhead); }
+
+  // used (has been allocated)
+  // free (available for future allocations)
+  // capacity (total size of chunk)
+  size_t used_word_size();
+  size_t free_word_size();
+  size_t capacity_word_size();
+
+  // 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(Metachunk* tc) const { return true; }
+  bool verify_par_locked() { return true; }
+
+  void assert_is_mangled() const {/* Don't check "\*/}
+
+#ifdef ASSERT
+  void mangle();
+#endif // ASSERT
+
+  void print_on(outputStream* st) const;
+  void verify();
+};
+#endif  // SHARE_VM_MEMORY_METACHUNK_HPP
--- a/src/share/vm/memory/metaspace.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/metaspace.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -24,9 +24,12 @@
 #include "precompiled.hpp"
 #include "gc_interface/collectedHeap.hpp"
 #include "memory/binaryTreeDictionary.hpp"
+#include "memory/freeList.hpp"
 #include "memory/collectorPolicy.hpp"
 #include "memory/filemap.hpp"
 #include "memory/freeList.hpp"
+#include "memory/metablock.hpp"
+#include "memory/metachunk.hpp"
 #include "memory/metaspace.hpp"
 #include "memory/metaspaceShared.hpp"
 #include "memory/resourceArea.hpp"
@@ -37,15 +40,8 @@
 #include "utilities/copy.hpp"
 #include "utilities/debug.hpp"
 
-// Define this macro to deallocate Metablock.  If not defined,
-// blocks are not yet deallocated and are only mangled.
-#undef DEALLOCATE_BLOCKS
-
-// Easily recognizable patterns
-// These patterns can be the same in 32bit or 64bit since
-// they only have to be easily recognizable.
-const void* metaspace_allocation_leader = (void*) 0X11111111;
-const void* metaspace_allocation_trailer = (void*) 0X77777777;
+typedef BinaryTreeDictionary<Metablock, FreeList> BlockTreeDictionary;
+typedef BinaryTreeDictionary<Metachunk, FreeList> ChunkTreeDictionary;
 
 // Parameters for stress mode testing
 const uint metadata_deallocate_a_lot_block = 10;
@@ -53,7 +49,6 @@
 size_t const allocation_from_dictionary_limit = 64 * K;
 const size_t metadata_chunk_initialize = 0xf7f7f7f7;
 const size_t metadata_deallocate = 0xf5f5f5f5;
-const size_t metadata_space_manager_allocate = 0xf3f3f3f3;
 
 MetaWord* last_allocated = 0;
 
@@ -62,11 +57,12 @@
   SmallIndex = 0,
   MediumIndex = 1,
   HumongousIndex = 2,
-  NumberOfFreeLists = 3
+  NumberOfFreeLists = 2,
+  NumberOfInUseLists = 3
 };
 
 static ChunkIndex next_chunk_index(ChunkIndex i) {
-  assert(i < NumberOfFreeLists, "Out of bound");
+  assert(i < NumberOfInUseLists, "Out of bound");
   return (ChunkIndex) (i+1);
 }
 
@@ -100,164 +96,13 @@
 // the Chunk after the header for the Chunk) where as Metachunks
 // point to space in a VirtualSpace.  To replace Metachunks with
 // Chunks, change Chunks so that they can be allocated out of a VirtualSpace.
-//
-
-// Metablock are the unit of allocation from a Chunk.  It contains
-// the size of the requested allocation in a debug build.
-// Also in a debug build it has a marker before and after the
-// body of the block. The address of the body is the address returned
-// by the allocation.
-//
-// Layout in a debug build.  In a product build only the body is present.
-//
-//     +-----------+-----------+------------+     +-----------+
-//     | word size | leader    | body       | ... | trailer   |
-//     +-----------+-----------+------------+     +-----------+
-//
-// 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 are not deallocated, rather
-// the Metachunk it is a part of will be deallocated when it's
-// associated class loader is collected.
-//
-// When the word size of a block is passed in to the deallocation
-// call the word size no longer needs to be part of a Metablock.
-
-class Metablock {
-  friend class VMStructs;
- private:
-  // Used to align the allocation (see below) and for debugging.
+size_t Metablock::_min_block_byte_size = sizeof(Metablock);
 #ifdef ASSERT
-  struct {
-    size_t _word_size;
-    void*  _leader;
-  } _header;
-  void* _data[1];
+  size_t Metablock::_overhead =
+    Chunk::aligned_overhead_size(sizeof(Metablock)) / BytesPerWord;
+#else
+  size_t Metablock::_overhead = 0;
 #endif
-  static size_t _overhead;
-
-#ifdef ASSERT
-  void set_word_size(size_t v) { _header._word_size = v; }
-  void* leader() { return _header._leader; }
-  void* trailer() {
-    jlong index = (jlong) _header._word_size - sizeof(_header)/BytesPerWord - 1;
-    assert(index > 0, err_msg("Bad indexling of trailer %d", index));
-    void** ptr = &_data[index];
-    return *ptr;
-  }
-  void set_leader(void* v) { _header._leader = v; }
-  void set_trailer(void* v) {
-    void** ptr = &_data[_header._word_size - sizeof(_header)/BytesPerWord - 1];
-    *ptr = v;
-  }
- public:
-  size_t word_size() { return _header._word_size; }
-#endif
- public:
-
-  static Metablock* initialize(MetaWord* p, size_t word_size);
-
-  // This places the body of the block at a 2 word boundary
-  // because every block starts on a 2 word boundary.  Work out
-  // how to make the body on a 2 word boundary if the block
-  // starts on a arbitrary boundary.  JJJ
-
-#ifdef ASSERT
-  MetaWord* data() { return (MetaWord*) &_data[0]; }
-#else
-  MetaWord* data() { return (MetaWord*) this; }
-#endif
-  static Metablock* metablock_from_data(MetaWord* p) {
-#ifdef ASSERT
-    size_t word_offset = offset_of(Metablock, _data)/BytesPerWord;
-    Metablock* result = (Metablock*) (p - word_offset);
-    return result;
-#else
-    return (Metablock*) p;
-#endif
-  }
-
-  static size_t overhead() { return _overhead; }
-  void verify();
-};
-
-//  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     |
-//            |              |            |          |
-//            |              |            |          | capacity
-//            |              |            |          |
-//            |              | <- top   --+          |
-//            |              |           ---+        |
-//            |              |              | used   |
-//            |              |              |        |
-//            |              |              |        |
-//            +--------------+ <- bottom ---+     ---+
-
-class Metachunk VALUE_OBJ_CLASS_SPEC {
-  // link to support lists of chunks
-  Metachunk* _next;
-
-  MetaWord* _bottom;
-  MetaWord* _end;
-  MetaWord* _top;
-  size_t _word_size;
-
-  // 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.
-  static size_t _overhead;
-
-  void set_bottom(MetaWord* v) { _bottom = v; }
-  void set_end(MetaWord* v) { _end = v; }
-  void set_top(MetaWord* v) { _top = v; }
-  void set_word_size(size_t v) { _word_size = v; }
- public:
-
-  // Used to add a Metachunk to a list of Metachunks
-  void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");}
-
-  Metablock* allocate(size_t word_size);
-  static Metachunk* initialize(MetaWord* ptr, size_t word_size);
-
-  // Accessors
-  Metachunk* next() const { return _next; }
-  MetaWord* bottom() const { return _bottom; }
-  MetaWord* end() const { return _end; }
-  MetaWord* top() const { return _top; }
-  size_t word_size() const { return _word_size; }
-  static size_t overhead() { return _overhead; }
-
-  // Reset top to bottom so chunk can be reused.
-  void reset_empty() { _top = (_bottom + _overhead); }
-  bool is_empty() { return _top == (_bottom + _overhead); }
-
-  // used (has been allocated)
-  // free (available for future allocations)
-  // capacity (total size of chunk)
-  size_t used_word_size();
-  size_t free_word_size();
-  size_t capacity_word_size();
-
-#ifdef ASSERT
-  void mangle() {
-    // Mangle the payload of the chunk and not the links that
-    // maintain list of chunks.
-    HeapWord* start = (HeapWord*)(bottom() + overhead());
-    size_t word_size = capacity_word_size() - overhead();
-    Copy::fill_to_words(start, word_size, metadata_chunk_initialize);
-  }
-#endif // ASSERT
-
-  void print_on(outputStream* st) const;
-  void verify();
-};
 
 
 // Pointer to list of Metachunks.
@@ -292,7 +137,10 @@
   //   SmallChunk
   //   MediumChunk
   //   HumongousChunk
-  ChunkList _free_chunks[3];
+  ChunkList _free_chunks[NumberOfFreeLists];
+
+  //   HumongousChunk
+  ChunkTreeDictionary _humongous_dictionary;
 
   // ChunkManager in all lists of this type
   size_t _free_chunks_total;
@@ -337,7 +185,9 @@
   }
   ChunkList* free_medium_chunks() { return &_free_chunks[1]; }
   ChunkList* free_small_chunks() { return &_free_chunks[0]; }
-  ChunkList* free_humongous_chunks() { return &_free_chunks[2]; }
+  ChunkTreeDictionary* humongous_dictionary() {
+    return &_humongous_dictionary;
+  }
 
   ChunkList* free_chunks(ChunkIndex index);
 
@@ -356,41 +206,35 @@
 
   void locked_print_free_chunks(outputStream* st);
   void locked_print_sum_free_chunks(outputStream* st);
+
+  void print_on(outputStream* st);
 };
 
 
 // Used to manage the free list of Metablocks (a block corresponds
 // to the allocation of a quantum of metadata).
 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
-#ifdef DEALLOCATE_BLOCKS
-  BinaryTreeDictionary<Metablock>* _dictionary;
-#endif
-  static Metablock* initialize_free_chunk(Metablock* block, size_t word_size);
-
-#ifdef DEALLOCATE_BLOCKS
+  BlockTreeDictionary* _dictionary;
+  static Metablock* initialize_free_chunk(MetaWord* p, size_t word_size);
+
   // Accessors
-  BinaryTreeDictionary<Metablock>* dictionary() const { return _dictionary; }
-#endif
+  BlockTreeDictionary* dictionary() const { return _dictionary; }
 
  public:
   BlockFreelist();
   ~BlockFreelist();
 
   // Get and return a block to the free list
-  Metablock* get_block(size_t word_size);
-  void return_block(Metablock* block, size_t word_size);
-
-  size_t totalSize() {
-#ifdef DEALLOCATE_BLOCKS
-    if (dictionary() == NULL) {
-      return 0;
-    } else {
-      return dictionary()->totalSize();
-    }
-#else
+  MetaWord* get_block(size_t word_size);
+  void return_block(MetaWord* p, size_t word_size);
+
+  size_t total_size() {
+  if (dictionary() == NULL) {
     return 0;
-#endif
+  } else {
+    return dictionary()->total_size();
   }
+}
 
   void print_on(outputStream* st) const;
 };
@@ -600,7 +444,6 @@
   };
 };
 
-
 class Metadebug : AllStatic {
   // Debugging support for Metaspaces
   static int _deallocate_block_a_lot_count;
@@ -655,7 +498,7 @@
   // 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* _chunks_in_use[NumberOfFreeLists];
+  Metachunk* _chunks_in_use[NumberOfInUseLists];
   Metachunk* _current_chunk;
 
   // Virtual space where allocation comes from.
@@ -700,24 +543,6 @@
   // Add chunk to the list of chunks in use
   void add_chunk(Metachunk* v, bool make_current);
 
-  // Debugging support
-  void verify_chunks_in_use_index(ChunkIndex index, Metachunk* v) {
-    switch (index) {
-    case 0:
-      assert(v->word_size() == SmallChunk, "Not a SmallChunk");
-      break;
-    case 1:
-      assert(v->word_size() == MediumChunk, "Not a MediumChunk");
-      break;
-    case 2:
-      assert(v->word_size() > MediumChunk, "Not a HumongousChunk");
-      break;
-    default:
-      assert(false, "Wrong list.");
-    }
-  }
-
- protected:
   Mutex* lock() const { return _lock; }
 
  public:
@@ -751,10 +576,10 @@
   MetaWord* allocate(size_t word_size);
 
   // Helper for allocations
-  Metablock* allocate_work(size_t word_size);
+  MetaWord* allocate_work(size_t word_size);
 
   // Returns a block to the per manager freelist
-  void deallocate(MetaWord* p);
+  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).
@@ -763,7 +588,7 @@
   // 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.
-  Metablock* grow_and_allocate(size_t word_size);
+  MetaWord* grow_and_allocate(size_t word_size);
 
   // debugging support.
 
@@ -780,6 +605,8 @@
 
 uint const SpaceManager::_small_chunk_limit = 4;
 
+
+
 const char* SpaceManager::_expand_lock_name =
   "SpaceManager chunk allocation lock";
 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
@@ -788,39 +615,26 @@
             SpaceManager::_expand_lock_name,
             Mutex::_allow_vm_block_flag);
 
-#ifdef ASSERT
-size_t Metablock::_overhead =
-  Chunk::aligned_overhead_size(sizeof(Metablock)) / BytesPerWord;
-#else
-size_t Metablock::_overhead = 0;
-#endif
 size_t Metachunk::_overhead =
   Chunk::aligned_overhead_size(sizeof(Metachunk)) / BytesPerWord;
 
 // New blocks returned by the Metaspace are zero initialized.
 // We should fix the constructors to not assume this instead.
 Metablock* Metablock::initialize(MetaWord* p, size_t word_size) {
+  if (p == NULL) {
+    return NULL;
+  }
+
   Metablock* result = (Metablock*) p;
 
   // Clear the memory
   Copy::fill_to_aligned_words((HeapWord*)result, word_size);
 #ifdef ASSERT
   result->set_word_size(word_size);
-  // Check after work size is set.
-  result->set_leader((void*) metaspace_allocation_leader);
-  result->set_trailer((void*) metaspace_allocation_trailer);
 #endif
   return result;
 }
 
-void Metablock::verify() {
-#ifdef ASSERT
-  assert(leader() == metaspace_allocation_leader &&
-         trailer() == metaspace_allocation_trailer,
-         "block has been corrupted");
-#endif
-}
-
 // Metachunk methods
 
 Metachunk* Metachunk::initialize(MetaWord* ptr, size_t word_size) {
@@ -843,18 +657,13 @@
 }
 
 
-Metablock* Metachunk::allocate(size_t word_size) {
-  Metablock* result = NULL;
+MetaWord* Metachunk::allocate(size_t word_size) {
+  MetaWord* result = NULL;
   // If available, bump the pointer to allocate.
   if (free_word_size() >= word_size) {
-    result = Metablock::initialize(_top, word_size);
+    result = _top;
     _top = _top + word_size;
   }
-#ifdef ASSERT
-  assert(result == NULL ||
-         result->word_size() == word_size,
-         "Block size is not set correctly");
-#endif
   return result;
 }
 
@@ -878,103 +687,85 @@
                bottom(), top(), end(), word_size());
 }
 
+#ifdef ASSERT
+void Metachunk::mangle() {
+  // Mangle the payload of the chunk and not the links that
+  // maintain list of chunks.
+  HeapWord* start = (HeapWord*)(bottom() + overhead());
+  size_t word_size = capacity_word_size() - overhead();
+  Copy::fill_to_words(start, word_size, metadata_chunk_initialize);
+}
+#endif // ASSERT
 
 void Metachunk::verify() {
 #ifdef ASSERT
   // Cannot walk through the blocks unless the blocks have
   // headers with sizes.
-  MetaWord* curr = bottom() + overhead();
-  while (curr < top()) {
-    Metablock* block = (Metablock*) curr;
-    size_t word_size = block->word_size();
-    block->verify();
-    curr = curr + word_size;
-  }
+  assert(_bottom <= _top &&
+         _top <= _end,
+         "Chunk has been smashed");
+  assert(SpaceManager::is_humongous(_word_size) ||
+         _word_size == SpaceManager::MediumChunk ||
+         _word_size == SpaceManager::SmallChunk,
+         "Chunk size is wrong");
 #endif
   return;
 }
 
 // BlockFreelist methods
 
-#ifdef DEALLOCATE_BLOCKS
 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
-#else
-BlockFreelist::BlockFreelist() {}
-#endif
 
 BlockFreelist::~BlockFreelist() {
-#ifdef DEALLOCATE_BLOCKS
   if (_dictionary != NULL) {
     if (Verbose && TraceMetadataChunkAllocation) {
       _dictionary->print_free_lists(gclog_or_tty);
     }
     delete _dictionary;
   }
-#endif
 }
 
-Metablock* BlockFreelist::initialize_free_chunk(Metablock* block, size_t word_size) {
-#ifdef DEALLOCATE_BLOCKS
-#ifdef ASSERT
-  assert(word_size = block->word_size(), "Wrong chunk size");
-#endif
-  Metablock* result = block;
-  result->setSize(word_size);
-  result->linkPrev(NULL);
-  result->linkNext(NULL);
-
-  return result;
-#else
-  ShouldNotReachHere();
+Metablock* BlockFreelist::initialize_free_chunk(MetaWord* p, size_t word_size) {
+  Metablock* block = (Metablock*) p;
+  block->set_word_size(word_size);
+  block->set_prev(NULL);
+  block->set_next(NULL);
+
   return block;
-#endif
 }
 
-void BlockFreelist::return_block(Metablock* block, size_t word_size) {
-#ifdef ASSERT
-  assert(word_size = block->word_size(), "Block size is wrong");;
-#endif
-  Metablock* free_chunk = initialize_free_chunk(block, word_size);
-#ifdef DEALLOCATE_BLOCKS
+void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
+  Metablock* free_chunk = initialize_free_chunk(p, word_size);
   if (dictionary() == NULL) {
-   _dictionary = new BinaryTreeDictionary<Metablock>(false /* adaptive_freelists */);
+   _dictionary = new BlockTreeDictionary();
   }
-  dictionary()->returnChunk(free_chunk);
-#endif
+  dictionary()->return_chunk(free_chunk);
 }
 
-Metablock* BlockFreelist::get_block(size_t word_size) {
-#ifdef DEALLOCATE_BLOCKS
+MetaWord* BlockFreelist::get_block(size_t word_size) {
   if (dictionary() == NULL) {
     return NULL;
   }
 
-  Metablock* free_chunk =
-    dictionary()->getChunk(word_size, FreeBlockDictionary<Metablock>::exactly);
-#else
-  Metablock* free_chunk = NULL;
-#endif
-  if (free_chunk == NULL) {
+  if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
+    // Dark matter.  Too small for dictionary.
     return NULL;
   }
-  assert(free_chunk->word_size() == word_size, "Size of chunk is incorrect");
-  Metablock* block = Metablock::initialize((MetaWord*) free_chunk, word_size);
-#ifdef ASSERT
-  assert(block->word_size() == word_size, "Block size is not set correctly");
-#endif
-
-  return block;
+
+  Metablock* free_block =
+    dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::exactly);
+  if (free_block == NULL) {
+    return NULL;
+  }
+
+  return (MetaWord*) free_block;
 }
 
 void BlockFreelist::print_on(outputStream* st) const {
-#ifdef DEALLOCATE_BLOCKS
   if (dictionary() == NULL) {
     return;
   }
   dictionary()->print_free_lists(st);
-#else
-  return;
-#endif
 }
 
 // VirtualSpaceNode methods
@@ -1597,14 +1388,11 @@
         Metadebug::deallocate_block_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
     Metadebug::set_deallocate_block_a_lot_count(0);
     for (uint i = 0; i < metadata_deallocate_a_lot_block; i++) {
-      Metablock* dummy_block = sm->allocate_work(raw_word_size);
+      MetaWord* dummy_block = sm->allocate_work(raw_word_size);
       if (dummy_block == 0) {
         break;
       }
-#ifdef ASSERT
-      assert(dummy_block->word_size() == raw_word_size, "Block size is not set correctly");
-#endif
-      sm->deallocate(dummy_block->data());
+      sm->deallocate(dummy_block, raw_word_size);
     }
   } else {
     Metadebug::inc_deallocate_block_a_lot_count();
@@ -1784,8 +1572,8 @@
 }
 
 void ChunkManager::locked_verify() {
+  locked_verify_free_chunks_count();
   locked_verify_free_chunks_total();
-  locked_verify_free_chunks_count();
 }
 
 void ChunkManager::locked_print_free_chunks(outputStream* st) {
@@ -1803,7 +1591,6 @@
   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() {
@@ -1818,6 +1605,7 @@
 
     result = result + list->sum_list_capacity();
   }
+  result = result + humongous_dictionary()->total_size();
   return result;
 }
 
@@ -1831,6 +1619,7 @@
     }
     count = count + list->sum_list_count();
   }
+  count = count + humongous_dictionary()->total_free_blocks();
   return count;
 }
 
@@ -1875,23 +1664,24 @@
   assert_lock_strong(SpaceManager::expand_lock());
 
   locked_verify();
-  ChunkList* free_list = find_free_chunks_list(word_size);
-  assert(free_list != NULL, "Sanity check");
-
-  Metachunk* chunk = free_list->head();
-  debug_only(Metachunk* debug_head = chunk;)
-
-  if (chunk == NULL) {
-    return NULL;
-  }
-
-  Metachunk* prev_chunk = chunk;
-  if (chunk->word_size() == word_size) {
-    // Chunk is being removed from the chunks free list.
-    dec_free_chunks_total(chunk->capacity_word_size());
+
+  Metachunk* chunk = NULL;
+  if (!SpaceManager::is_humongous(word_size)) {
+    ChunkList* free_list = find_free_chunks_list(word_size);
+    assert(free_list != NULL, "Sanity check");
+
+    chunk = free_list->head();
+    debug_only(Metachunk* debug_head = chunk;)
+
+    if (chunk == NULL) {
+      return NULL;
+    }
+
     // Remove the chunk as the head of the list.
     free_list->set_head(chunk->next());
     chunk->set_next(NULL);
+    // Chunk has been removed from the chunks free list.
+    dec_free_chunks_total(chunk->capacity_word_size());
 
     if (TraceMetadataChunkAllocation && Verbose) {
       tty->print_cr("ChunkManager::free_chunks_get: free_list "
@@ -1899,79 +1689,24 @@
                     free_list, chunk, chunk->word_size());
     }
   } else {
-    assert(SpaceManager::is_humongous(word_size),
-      "Should only need to check humongous");
-    // This code to find the best fit is just for purposes of
-    // investigating the loss due to fragmentation on a humongous
-    // chunk.  It will be replace by a binaryTreeDictionary for
-    // the humongous chunks.
-    uint count = 0;
-    Metachunk* best_fit = NULL;
-    Metachunk* best_fit_prev = NULL;
-    while (chunk != NULL) {
-      count++;
-      if (chunk->word_size() < word_size) {
-        prev_chunk = chunk;
-        chunk = chunk->next();
-      } else if (chunk->word_size() == word_size) {
-        break;
-      } else {
-        if (best_fit == NULL ||
-            best_fit->word_size() > chunk->word_size()) {
-          best_fit_prev = prev_chunk;
-          best_fit = chunk;
-        }
-        prev_chunk = chunk;
-        chunk = chunk->next();
+    chunk = humongous_dictionary()->get_chunk(
+      word_size,
+      FreeBlockDictionary<Metachunk>::atLeast);
+
+    if (chunk != NULL) {
+      if (TraceMetadataHumongousAllocation) {
+        size_t waste = chunk->word_size() - word_size;
+        tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
+                      " for requested size " SIZE_FORMAT
+                      " waste " SIZE_FORMAT,
+                      chunk->word_size(), word_size, waste);
       }
+      // Chunk is being removed from the chunks free list.
+      dec_free_chunks_total(chunk->capacity_word_size());
+#ifdef ASSERT
+      chunk->set_is_free(false);
+#endif
     }
-      if (chunk == NULL) {
-        prev_chunk = best_fit_prev;
-        chunk = best_fit;
-      }
-      if (chunk != NULL) {
-        if (TraceMetadataHumongousAllocation) {
-          size_t waste = chunk->word_size() - word_size;
-          tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
-                        " for requested size " SIZE_FORMAT
-                        " waste " SIZE_FORMAT
-                        " found at " SIZE_FORMAT " of " SIZE_FORMAT,
-                        chunk->word_size(), word_size, waste,
-                        count, free_list->sum_list_count());
-        }
-        // Chunk is being removed from the chunks free list.
-        dec_free_chunks_total(chunk->capacity_word_size());
-        // Remove the chunk if it is at the head of the list.
-        if (chunk == free_list->head()) {
-          free_list->set_head(chunk->next());
-
-          if (TraceMetadataHumongousAllocation) {
-            tty->print_cr("ChunkManager::free_chunks_get: humongous free_list "
-                          PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT
-                          " new head " PTR_FORMAT,
-                          free_list, chunk, chunk->word_size(),
-                          free_list->head());
-          }
-        } else {
-          // Remove a chunk in the interior of the list
-          prev_chunk->set_next(chunk->next());
-
-          if (TraceMetadataHumongousAllocation) {
-            tty->print_cr("ChunkManager::free_chunks_get: humongous free_list "
-                          PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT
-                          PTR_FORMAT "  prev " PTR_FORMAT " next " PTR_FORMAT,
-                          free_list, chunk, chunk->word_size(),
-                          prev_chunk, chunk->next());
-          }
-        }
-        chunk->set_next(NULL);
-      } else {
-        if (TraceMetadataHumongousAllocation) {
-          tty->print_cr("ChunkManager::free_chunks_get: New humongous chunk of size "
-                        SIZE_FORMAT,
-                        word_size);
-        }
-      }
   }
   locked_verify();
   return chunk;
@@ -2000,12 +1735,18 @@
   return chunk;
 }
 
+void ChunkManager::print_on(outputStream* out) {
+  if (PrintFLSStatistics != 0) {
+    humongous_dictionary()->report_statistics();
+  }
+}
+
 // SpaceManager methods
 
 size_t SpaceManager::sum_free_in_chunks_in_use() const {
   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
   size_t free = 0;
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
     Metachunk* chunk = chunks_in_use(i);
     while (chunk != NULL) {
       free += chunk->free_word_size();
@@ -2018,11 +1759,12 @@
 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
   size_t result = 0;
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
-   // Count the free space in all the chunk but not the
-   // current chunk from which allocations are still being done.
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
+
+
    result += sum_waste_in_chunks_in_use(i);
   }
+
   return result;
 }
 
@@ -2033,10 +1775,10 @@
   // Count the free space in all the chunk but not the
   // current chunk from which allocations are still being done.
   if (chunk != NULL) {
-    while (chunk != NULL) {
-      if (chunk != current_chunk()) {
-        result += chunk->free_word_size();
-      }
+    Metachunk* prev = chunk;
+    while (chunk != NULL && chunk != current_chunk()) {
+      result += chunk->free_word_size();
+      prev = chunk;
       chunk = chunk->next();
       count++;
     }
@@ -2047,7 +1789,7 @@
 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
   size_t sum = 0;
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
     Metachunk* chunk = chunks_in_use(i);
     while (chunk != NULL) {
       // Just changed this sum += chunk->capacity_word_size();
@@ -2061,9 +1803,10 @@
 
 size_t SpaceManager::sum_count_in_chunks_in_use() {
   size_t count = 0;
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
     count = count + sum_count_in_chunks_in_use(i);
   }
+
   return count;
 }
 
@@ -2081,7 +1824,7 @@
 size_t SpaceManager::sum_used_in_chunks_in_use() const {
   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
   size_t used = 0;
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
     Metachunk* chunk = chunks_in_use(i);
     while (chunk != NULL) {
       used += chunk->used_word_size();
@@ -2139,15 +1882,13 @@
     gclog_or_tty->print_cr("  word_size " PTR_FORMAT, word_size);
     gclog_or_tty->print_cr("  chunk_word_size " PTR_FORMAT,
                            chunk_word_size);
-    gclog_or_tty->print_cr("    block overhead " PTR_FORMAT
-                           " chunk overhead " PTR_FORMAT,
-                           Metablock::overhead(),
+    gclog_or_tty->print_cr("    chunk overhead " PTR_FORMAT,
                            Metachunk::overhead());
   }
   return chunk_word_size;
 }
 
-Metablock* SpaceManager::grow_and_allocate(size_t word_size) {
+MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
   assert(vs_list()->current_virtual_space() != NULL,
          "Should have been set");
   assert(current_chunk() == NULL ||
@@ -2180,7 +1921,7 @@
 void SpaceManager::print_on(outputStream* st) const {
 
   for (ChunkIndex i = SmallIndex;
-       i < NumberOfFreeLists ;
+       i < NumberOfInUseLists ;
        i = next_chunk_index(i) ) {
     st->print_cr("  chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
                  chunks_in_use(i),
@@ -2191,8 +1932,11 @@
                sum_waste_in_chunks_in_use(SmallIndex),
                sum_waste_in_chunks_in_use(MediumIndex),
                sum_waste_in_chunks_in_use(HumongousIndex));
-  // Nothing in them yet
-  // block_freelists()->print_on(st);
+  // block free lists
+  if (block_freelists() != NULL) {
+    st->print_cr("total in block free lists " SIZE_FORMAT,
+      block_freelists()->total_size());
+  }
 }
 
 SpaceManager::SpaceManager(Mutex* lock, VirtualSpaceList* vs_list) :
@@ -2200,7 +1944,7 @@
   _allocation_total(0),
   _lock(lock) {
   Metadebug::init_allocation_fail_alot_count();
-  for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+  for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
     _chunks_in_use[i] = NULL;
   }
   _current_chunk = NULL;
@@ -2262,22 +2006,24 @@
   // Humongous chunks are never the current chunk.
   Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
 
-  if (humongous_chunks != NULL) {
-    chunk_manager->free_humongous_chunks()->add_at_head(humongous_chunks);
-    set_chunks_in_use(HumongousIndex, NULL);
+  while (humongous_chunks != NULL) {
+#ifdef ASSERT
+    humongous_chunks->set_is_free(true);
+#endif
+    Metachunk* next_humongous_chunks = humongous_chunks->next();
+    chunk_manager->humongous_dictionary()->return_chunk(humongous_chunks);
+    humongous_chunks = next_humongous_chunks;
   }
+  set_chunks_in_use(HumongousIndex, NULL);
   chunk_manager->locked_verify();
 }
 
-void SpaceManager::deallocate(MetaWord* p) {
+void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
   assert_lock_strong(_lock);
-  ShouldNotReachHere();  // Where is this needed.
-#ifdef DEALLOCATE_BLOCKS
-  Metablock* block = Metablock::metablock_from_data(p);
-  // This is expense but kept it until integration JJJ
-  assert(contains((address)block), "Block does not belong to this metaspace");
-  block_freelists()->return_block(block, word_size);
-#endif
+  size_t min_size = TreeChunk<Metablock, FreeList>::min_size();
+  assert(word_size >= min_size,
+    err_msg("Should not deallocate dark matter " SIZE_FORMAT, word_size));
+  block_freelists()->return_block(p, word_size);
 }
 
 // Adds a chunk to the list of chunks in use.
@@ -2366,50 +2112,40 @@
 MetaWord* SpaceManager::allocate(size_t word_size) {
   MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
 
-  size_t block_overhead = Metablock::overhead();
   // If only the dictionary is going to be used (i.e., no
   // indexed free list), then there is a minimum size requirement.
   // MinChunkSize is a placeholder for the real minimum size JJJ
-  size_t byte_size_with_overhead = (word_size + block_overhead) * BytesPerWord;
-#ifdef DEALLOCATE_BLOCKS
-  size_t raw_bytes_size = MAX2(ARENA_ALIGN(byte_size_with_overhead),
-                               MinChunkSize * BytesPerWord);
-#else
-  size_t raw_bytes_size = ARENA_ALIGN(byte_size_with_overhead);
-#endif
+  size_t byte_size = word_size * BytesPerWord;
+
+  size_t byte_size_with_overhead = byte_size + Metablock::overhead();
+
+  size_t raw_bytes_size = MAX2(byte_size_with_overhead,
+                               Metablock::min_block_byte_size());
+  raw_bytes_size = ARENA_ALIGN(raw_bytes_size);
   size_t raw_word_size = raw_bytes_size / BytesPerWord;
   assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
 
   BlockFreelist* fl =  block_freelists();
-  Metablock* block = NULL;
+  MetaWord* p = NULL;
   // 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->totalSize() > allocation_from_dictionary_limit) {
-    block = fl->get_block(raw_word_size);
+  if (fl->total_size() > allocation_from_dictionary_limit) {
+    p = fl->get_block(raw_word_size);
   }
-  if (block == NULL) {
-    block = allocate_work(raw_word_size);
-    if (block == NULL) {
-      return NULL;
-    }
+  if (p == NULL) {
+    p = allocate_work(raw_word_size);
   }
   Metadebug::deallocate_block_a_lot(this, raw_word_size);
 
-  // Push the allocation past the word containing the size and leader.
-#ifdef ASSERT
-  MetaWord* result =  block->data();
-  return result;
-#else
-  return (MetaWord*) block;
-#endif
+  return p;
 }
 
 // Returns the address of spaced allocated for "word_size".
 // This methods does not know about blocks (Metablocks)
-Metablock* SpaceManager::allocate_work(size_t word_size) {
+MetaWord* SpaceManager::allocate_work(size_t word_size) {
   assert_lock_strong(_lock);
 #ifdef ASSERT
   if (Metadebug::test_metadata_failure()) {
@@ -2417,7 +2153,7 @@
   }
 #endif
   // Is there space in the current chunk?
-  Metablock* result = NULL;
+  MetaWord* result = NULL;
 
   // For DumpSharedSpaces, only allocate out of the current chunk which is
   // never null because we gave it the size we wanted.   Caller reports out
@@ -2436,8 +2172,8 @@
   }
   if (result > 0) {
     inc_allocation_total(word_size);
-    assert(result != (Metablock*) chunks_in_use(MediumIndex), "Head of the list is being allocated");
-    assert(result->word_size() == word_size, "Size not set correctly");
+    assert(result != (MetaWord*) chunks_in_use(MediumIndex),
+           "Head of the list is being allocated");
   }
 
   return result;
@@ -2447,13 +2183,13 @@
   // If there are blocks in the dictionary, then
   // verfication of chunks does not work since
   // being in the dictionary alters a chunk.
-  if (block_freelists()->totalSize() == 0) {
+  if (block_freelists()->total_size() == 0) {
     // Skip the small chunks because their next link points to
     // medium chunks.  This is because the small chunk is the
     // current chunk (for allocations) until it is full and the
     // the addition of the next chunk does not NULL the next
     // like of the small chunk.
-    for (ChunkIndex i = MediumIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
+    for (ChunkIndex i = MediumIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
       Metachunk* curr = chunks_in_use(i);
       while (curr != NULL) {
         curr->verify();
@@ -2492,7 +2228,7 @@
 
   // Add up statistics for all chunks in this SpaceManager.
   for (ChunkIndex index = SmallIndex;
-       index < NumberOfFreeLists;
+       index < NumberOfInUseLists;
        index = next_chunk_index(index)) {
     for (Metachunk* curr = chunks_in_use(index);
          curr != NULL;
@@ -2521,7 +2257,7 @@
 #ifdef ASSERT
 void SpaceManager::mangle_freed_chunks() {
   for (ChunkIndex index = SmallIndex;
-       index < NumberOfFreeLists;
+       index < NumberOfInUseLists;
        index = next_chunk_index(index)) {
     for (Metachunk* curr = chunks_in_use(index);
          curr != NULL;
@@ -2833,13 +2569,12 @@
   }
 }
 
-
 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
   // DumpSharedSpaces doesn't use class metadata area (yet)
   if (mdtype == ClassType && !DumpSharedSpaces) {
-    return class_vsm()->allocate(word_size);
+    return  class_vsm()->allocate(word_size);
   } else {
-    return vsm()->allocate(word_size);
+    return  vsm()->allocate(word_size);
   }
 }
 
@@ -2853,6 +2588,7 @@
     gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
       " to " SIZE_FORMAT, before_inc, MetaspaceGC::capacity_until_GC());
   }
+
   result = allocate(word_size, mdtype);
 
   return result;
@@ -2889,37 +2625,39 @@
 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
   if (SafepointSynchronize::is_at_safepoint()) {
     assert(Thread::current()->is_VM_thread(), "should be the VM thread");
-    // Don't take lock
-#ifdef DEALLOCATE_BLOCKS
+    // Don't take Heap_lock
+    MutexLocker ml(vsm()->lock());
+    if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
+      // Dark matter.  Too small for dictionary.
+#ifdef ASSERT
+      Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
+#endif
+      return;
+    }
     if (is_class) {
-      class_vsm()->deallocate(ptr);
+       class_vsm()->deallocate(ptr, word_size);
     } else {
-      vsm()->deallocate(ptr);
+      vsm()->deallocate(ptr, word_size);
     }
-#else
-#ifdef ASSERT
-    Copy::fill_to_words((HeapWord*)ptr, word_size, metadata_deallocate);
-#endif
-#endif
-
   } else {
     MutexLocker ml(vsm()->lock());
 
-#ifdef DEALLOCATE_BLOCKS
+    if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
+      // Dark matter.  Too small for dictionary.
+#ifdef ASSERT
+      Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
+#endif
+      return;
+    }
     if (is_class) {
-      class_vsm()->deallocate(ptr);
+      class_vsm()->deallocate(ptr, word_size);
     } else {
-      vsm()->deallocate(ptr);
+      vsm()->deallocate(ptr, word_size);
     }
-#else
-#ifdef ASSERT
-    Copy::fill_to_words((HeapWord*)ptr, word_size, metadata_deallocate);
-#endif
-#endif
   }
 }
 
-MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
+Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
                               bool read_only, MetadataType mdtype, TRAPS) {
   if (HAS_PENDING_EXCEPTION) {
     assert(false, "Should not allocate with exception pending");
@@ -2943,7 +2681,7 @@
     if (result == NULL) {
       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
     }
-    return result;
+    return Metablock::initialize(result, word_size);
   }
 
   result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
@@ -2951,7 +2689,7 @@
   if (result == NULL) {
     // Try to clean out some memory and retry.
     result =
-    Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
+      Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
         loader_data, word_size, mdtype);
 
     // If result is still null, we are out of memory.
@@ -2967,7 +2705,7 @@
       THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
     }
   }
-  return result;
+  return Metablock::initialize(result, word_size);
 }
 
 void Metaspace::print_on(outputStream* out) const {
--- a/src/share/vm/memory/metaspace.hpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/memory/metaspace.hpp	Tue Sep 18 23:35:42 2012 -0700
@@ -57,12 +57,10 @@
 //
 
 class ClassLoaderData;
+class Metablock;
 class MetaWord;
 class Mutex;
 class outputStream;
-class FreeChunk;
-template <class Chunk_t> class FreeList;
-template <class Chunk_t> class BinaryTreeDictionary;
 class SpaceManager;
 
 // Metaspaces each have a  SpaceManager and allocations
@@ -128,7 +126,7 @@
   size_t capacity_words(MetadataType mdtype) const;
   size_t waste_words(MetadataType mdtype) const;
 
-  static MetaWord* allocate(ClassLoaderData* loader_data, size_t size,
+  static Metablock* allocate(ClassLoaderData* loader_data, size_t size,
                             bool read_only, MetadataType mdtype, TRAPS);
   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
 
--- a/src/share/vm/runtime/vmStructs.cpp	Fri Oct 19 11:26:17 2012 -0700
+++ b/src/share/vm/runtime/vmStructs.cpp	Tue Sep 18 23:35:42 2012 -0700
@@ -59,6 +59,7 @@
 #include "memory/generation.hpp"
 #include "memory/generationSpec.hpp"
 #include "memory/heap.hpp"
+#include "memory/metablock.hpp"
 #include "memory/space.hpp"
 #include "memory/tenuredGeneration.hpp"
 #include "memory/universe.hpp"
@@ -249,6 +250,7 @@
 typedef Hashtable<Klass*, mtClass>            KlassHashtable;
 typedef HashtableEntry<Klass*, mtClass>       KlassHashtableEntry;
 typedef TwoOopHashtable<Symbol*, mtClass>     SymbolTwoOopHashtable;
+typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
 
 //--------------------------------------------------------------------------------
 // VM_STRUCTS
@@ -1237,7 +1239,15 @@
   nonstatic_field(AccessFlags,                 _flags,                                       jint)                                   \
   nonstatic_field(elapsedTimer,                _counter,                                     jlong)                                  \
   nonstatic_field(elapsedTimer,                _active,                                      bool)                                   \
-  nonstatic_field(InvocationCounter,           _counter,                                     unsigned int)
+  nonstatic_field(InvocationCounter,           _counter,                                     unsigned int)                           \
+  volatile_nonstatic_field(FreeChunk,          _size,                                        size_t)                                 \
+  nonstatic_field(FreeChunk,                   _next,                                        FreeChunk*)                             \
+  nonstatic_field(FreeChunk,                   _prev,                                        FreeChunk*)                             \
+  nonstatic_field(FreeList<FreeChunk>,         _size,                                        size_t)                                 \
+  nonstatic_field(FreeList<Metablock>,         _size,                                        size_t)                                 \
+  nonstatic_field(FreeList<FreeChunk>,         _count,                                       ssize_t)                                \
+  nonstatic_field(FreeList<Metablock>,         _count,                                       ssize_t)                                \
+  nonstatic_field(MetablockTreeDictionary,     _total_size,                                  size_t)
 
   /* NOTE that we do not use the last_entry() macro here; it is used  */
   /* in vmStructs_<os>_<cpu>.hpp's VM_STRUCTS_OS_CPU macro (and must  */
@@ -2080,7 +2090,24 @@
   declare_toplevel_type(Universe)                                         \
   declare_toplevel_type(vframeArray)                                      \
   declare_toplevel_type(vframeArrayElement)                               \
-  declare_toplevel_type(Annotations*)
+  declare_toplevel_type(Annotations*)                                     \
+                                                                          \
+  /***************/                                                       \
+  /* Miscellaneous types */                                               \
+  /***************/                                                       \
+                                                                          \
+  /* freelist */                                                          \
+  declare_toplevel_type(FreeChunk*)                                       \
+  declare_toplevel_type(Metablock*)                                       \
+  declare_toplevel_type(FreeBlockDictionary<FreeChunk>*)                  \
+  declare_toplevel_type(FreeList<FreeChunk>*)                             \
+  declare_toplevel_type(FreeList<FreeChunk>)                              \
+  declare_toplevel_type(FreeBlockDictionary<Metablock>*)                  \
+  declare_toplevel_type(FreeList<Metablock>*)                             \
+  declare_toplevel_type(FreeList<Metablock>)                              \
+  declare_toplevel_type(MetablockTreeDictionary*)                         \
+  declare_type(MetablockTreeDictionary, FreeBlockDictionary<Metablock>)   \
+              declare_type(MetablockTreeDictionary, FreeBlockDictionary<Metablock>)
 
 
   /* NOTE that we do not use the last_entry() macro here; it is used  */