diff -r 351481a5cf31 -r 6182ca66bc7b hotspot/src/share/vm/memory/binaryTreeDictionary.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/binaryTreeDictionary.cpp	Thu Mar 29 19:46:24 2012 -0700
@@ -0,0 +1,1343 @@
+/*
+ * Copyright (c) 2001, 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/shared/allocationStats.hpp"
+#include "memory/binaryTreeDictionary.hpp"
+#include "runtime/globals.hpp"
+#include "utilities/ostream.hpp"
+#ifndef SERIALGC
+#include "gc_implementation/shared/spaceDecorator.hpp"
+#include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
+#endif // SERIALGC
+
+////////////////////////////////////////////////////////////////////////////////
+// A binary tree based search structure for free blocks.
+// This is currently used in the Concurrent Mark&Sweep implementation.
+////////////////////////////////////////////////////////////////////////////////
+
+template <class Chunk>
+TreeChunk<Chunk>* TreeChunk<Chunk>::as_TreeChunk(Chunk* fc) {
+  // Do some assertion checking here.
+  return (TreeChunk<Chunk>*) fc;
+}
+
+template <class Chunk>
+void TreeChunk<Chunk>::verifyTreeChunkList() const {
+  TreeChunk<Chunk>* nextTC = (TreeChunk<Chunk>*)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");
+  }
+  if (nextTC != NULL) {
+    guarantee(as_TreeChunk(nextTC->prev()) == this, "broken chain");
+    guarantee(nextTC->size() == size(), "wrong size");
+    nextTC->verifyTreeChunkList();
+  }
+}
+
+
+template <class Chunk>
+TreeList<Chunk>* TreeList<Chunk>::as_TreeList(TreeChunk<Chunk>* 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();
+  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->setParent(NULL);
+  tl->setLeft(NULL);
+  tl->setRight(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
+  // (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->setSize(size);
+  tc->linkPrev(NULL);
+  tc->linkNext(NULL);
+  TreeList<Chunk>* tl = TreeList<Chunk>::as_TreeList(tc);
+  return tl;
+}
+
+template <class Chunk>
+TreeList<Chunk>* TreeList<Chunk>::removeChunkReplaceIfNeeded(TreeChunk<Chunk>* tc) {
+
+  TreeList<Chunk>* retTL = this;
+  Chunk* 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() ||
+    this == parent()->right(), "list is inconsistent");
+  assert(tc->isFree(), "Header is not marked correctly");
+  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());
+  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
+    // 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
+    // list can be the start of a free range.  Free ranges are removed
+    // from the free lists so that they are not available to be
+    // 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.
+    if (nextTC == NULL) {
+      assert(prevFC == NULL, "Not last chunk in the list");
+      set_tail(NULL);
+      set_head(NULL);
+    } else {
+      // copy embedded list.
+      nextTC->set_embedded_list(tc->embedded_list());
+      retTL = nextTC->embedded_list();
+      // Fix the pointer to the list in each chunk in the list.
+      // 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())) {
+        curTC->set_list(retTL);
+      }
+      // Fix the parent to point to the new TreeList<Chunk>.
+      if (retTL->parent() != NULL) {
+        if (this == retTL->parent()->left()) {
+          retTL->parent()->setLeft(retTL);
+        } else {
+          assert(this == retTL->parent()->right(), "Parent is incorrect");
+          retTL->parent()->setRight(retTL);
+        }
+      }
+      // Fix the children's parent pointers to point to the
+      // new list.
+      assert(right() == retTL->right(), "Should have been copied");
+      if (retTL->right() != NULL) {
+        retTL->right()->setParent(retTL);
+      }
+      assert(left() == retTL->left(), "Should have been copied");
+      if (retTL->left() != NULL) {
+        retTL->left()->setParent(retTL);
+      }
+      retTL->link_head(nextTC);
+      assert(nextTC->isFree(), "Should be a free chunk");
+    }
+  } else {
+    if (nextTC == NULL) {
+      // Removing chunk at tail of list
+      link_tail(prevFC);
+    }
+    // Chunk is interior to the list
+    prevFC->linkAfter(nextTC);
+  }
+
+  // Below this point the embeded TreeList<Chunk> being used for the
+  // tree node may have changed. Don't use "this"
+  // TreeList<Chunk>*.
+  // chunk should still be a free chunk (bit set in _prev)
+  assert(!retTL->head() || retTL->size() == retTL->head()->size(),
+    "Wrong sized chunk in list");
+  debug_only(
+    tc->linkPrev(NULL);
+    tc->linkNext(NULL);
+    tc->set_list(NULL);
+    bool prev_found = false;
+    bool next_found = false;
+    for (Chunk* curFC = retTL->head();
+         curFC != NULL; curFC = curFC->next()) {
+      assert(curFC != tc, "Chunk is still in list");
+      if (curFC == prevFC) {
+        prev_found = true;
+      }
+      if (curFC == nextTC) {
+        next_found = true;
+      }
+    }
+    assert(prevFC == NULL || prev_found, "Chunk was lost from list");
+    assert(nextTC == NULL || next_found, "Chunk was lost from list");
+    assert(retTL->parent() == NULL ||
+           retTL == retTL->parent()->left() ||
+           retTL == retTL->parent()->right(),
+           "list is inconsistent");
+  )
+  retTL->decrement_count();
+
+  assert(tc->isFree(), "Should still be a free chunk");
+  assert(retTL->head() == NULL || retTL->head()->prev() == NULL,
+    "list invariant");
+  assert(retTL->tail() == NULL || retTL->tail()->next() == NULL,
+    "list invariant");
+  return retTL;
+}
+
+template <class Chunk>
+void TreeList<Chunk>::returnChunkAtTail(TreeChunk<Chunk>* 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");
+  // which means that the list can never be empty.
+  assert(!verifyChunkInFreeLists(chunk), "Double entry");
+  assert(head() == NULL || head()->prev() == NULL, "list invariant");
+  assert(tail() == NULL || tail()->next() == NULL, "list invariant");
+
+  Chunk* fc = tail();
+  fc->linkAfter(chunk);
+  link_tail(chunk);
+
+  assert(!tail() || size() == tail()->size(), "Wrong sized chunk in list");
+  FreeList<Chunk>::increment_count();
+  debug_only(increment_returnedBytes_by(chunk->size()*sizeof(HeapWord));)
+  assert(head() == NULL || head()->prev() == NULL, "list invariant");
+  assert(tail() == NULL || tail()->next() == NULL, "list invariant");
+}
+
+// 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>::returnChunkAtHead(TreeChunk<Chunk>* 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");
+  assert(!verifyChunkInFreeLists(chunk), "Double entry");
+  assert(head() == NULL || head()->prev() == NULL, "list invariant");
+  assert(tail() == NULL || tail()->next() == NULL, "list invariant");
+
+  Chunk* fc = head()->next();
+  if (fc != NULL) {
+    chunk->linkAfter(fc);
+  } else {
+    assert(tail() == NULL, "List is inconsistent");
+    link_tail(chunk);
+  }
+  head()->linkAfter(chunk);
+  assert(!head() || size() == head()->size(), "Wrong sized chunk in list");
+  FreeList<Chunk>::increment_count();
+  debug_only(increment_returnedBytes_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>
+TreeChunk<Chunk>* TreeList<Chunk>::first_available() {
+  assert(head() != NULL, "The head of the list cannot be NULL");
+  Chunk* fc = head()->next();
+  TreeChunk<Chunk>* retTC;
+  if (fc == NULL) {
+    retTC = head_as_TreeChunk();
+  } else {
+    retTC = TreeChunk<Chunk>::as_TreeChunk(fc);
+  }
+  assert(retTC->list() == this, "Wrong type of chunk.");
+  return retTC;
+}
+
+// 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() {
+  assert(head() != NULL, "The head of the list cannot be NULL");
+  Chunk* fc = head()->next();
+  TreeChunk<Chunk>* 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;
+    while (fc->next() != NULL) {
+      if ((HeapWord*)last < (HeapWord*)fc) {
+        last = fc;
+      }
+      fc = fc->next();
+    }
+    retTC = TreeChunk<Chunk>::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),
+  _totalSize(0), _totalFreeBlocks(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");
+
+  reset(mr);
+  assert(root()->left() == NULL, "reset check failed");
+  assert(root()->right() == NULL, "reset check failed");
+  assert(root()->head()->next() == NULL, "reset check failed");
+  assert(root()->head()->prev() == NULL, "reset check failed");
+  assert(totalSize() == root()->size(), "reset check failed");
+  assert(totalFreeBlocks() == 1, "reset check failed");
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::inc_totalSize(size_t inc) {
+  _totalSize = _totalSize + inc;
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::dec_totalSize(size_t dec) {
+  _totalSize = _totalSize - 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()));
+  set_totalSize(mr.word_size());
+  set_totalFreeBlocks(1);
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::reset(HeapWord* addr, size_t byte_size) {
+  MemRegion mr(addr, heap_word_size(byte_size));
+  reset(mr);
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::reset() {
+  set_root(NULL);
+  set_totalSize(0);
+  set_totalFreeBlocks(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>::getChunkFromTree(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither, bool splay)
+{
+  TreeList<Chunk> *curTL, *prevTL;
+  TreeChunk<Chunk>* retTC = NULL;
+  assert(size >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "minimum chunk size");
+  if (FLSVerifyDictionary) {
+    verifyTree();
+  }
+  // starting at the root, work downwards trying to find match.
+  // Remember the last node of size too great or too small.
+  for (prevTL = curTL = root(); curTL != NULL;) {
+    if (curTL->size() == size) {        // exact match
+      break;
+    }
+    prevTL = curTL;
+    if (curTL->size() < size) {        // proceed to right sub-tree
+      curTL = curTL->right();
+    } else {                           // proceed to left sub-tree
+      assert(curTL->size() > size, "size inconsistency");
+      curTL = curTL->left();
+    }
+  }
+  if (curTL == NULL) { // couldn't find exact match
+
+    if (dither == FreeBlockDictionary<Chunk>::exactly) return NULL;
+
+    // try and find the next larger size by walking back up the search path
+    for (curTL = prevTL; curTL != NULL;) {
+      if (curTL->size() >= size) break;
+      else curTL = curTL->parent();
+    }
+    assert(curTL == NULL || curTL->count() > 0,
+      "An empty list should not be in the tree");
+  }
+  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 = findList(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) {
+      semiSplayStep(curTL);
+    }
+    retTC = curTL->first_available();
+    assert((retTC != NULL) && (curTL->count() > 0),
+      "A list in the binary tree should not be NULL");
+    assert(retTC->size() >= size,
+      "A chunk of the wrong size was found");
+    removeChunkFromTree(retTC);
+    assert(retTC->isFree(), "Header is not marked correctly");
+  }
+
+  if (FLSVerifyDictionary) {
+    verify();
+  }
+  return retTC;
+}
+
+template <class Chunk>
+TreeList<Chunk>* BinaryTreeDictionary<Chunk>::findList(size_t size) const {
+  TreeList<Chunk>* curTL;
+  for (curTL = root(); curTL != NULL;) {
+    if (curTL->size() == size) {        // exact match
+      break;
+    }
+
+    if (curTL->size() < size) {        // proceed to right sub-tree
+      curTL = curTL->right();
+    } else {                           // proceed to left sub-tree
+      assert(curTL->size() > size, "size inconsistency");
+      curTL = curTL->left();
+    }
+  }
+  return curTL;
+}
+
+
+template <class Chunk>
+bool BinaryTreeDictionary<Chunk>::verifyChunkInFreeLists(Chunk* tc) const {
+  size_t size = tc->size();
+  TreeList<Chunk>* tl = findList(size);
+  if (tl == NULL) {
+    return false;
+  } else {
+    return tl->verifyChunkInFreeLists(tc);
+  }
+}
+
+template <class Chunk>
+Chunk* BinaryTreeDictionary<Chunk>::findLargestDict() const {
+  TreeList<Chunk> *curTL = root();
+  if (curTL != NULL) {
+    while(curTL->right() != NULL) curTL = curTL->right();
+    return curTL->largest_address();
+  } else {
+    return NULL;
+  }
+}
+
+// Remove the current chunk from the tree.  If it is not the last
+// 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>::removeChunkFromTree(TreeChunk<Chunk>* tc) {
+  assert(tc != NULL, "Should not call with a NULL chunk");
+  assert(tc->isFree(), "Header is not marked correctly");
+
+  TreeList<Chunk> *newTL, *parentTL;
+  TreeChunk<Chunk>* retTC;
+  TreeList<Chunk>* tl = tc->list();
+  debug_only(
+    bool removing_only_chunk = false;
+    if (tl == _root) {
+      if ((_root->left() == NULL) && (_root->right() == NULL)) {
+        if (_root->count() == 1) {
+          assert(_root->head() == tc, "Should only be this one chunk");
+          removing_only_chunk = true;
+        }
+      }
+    }
+  )
+  assert(tl != NULL, "List should be set");
+  assert(tl->parent() == NULL || tl == tl->parent()->left() ||
+         tl == tl->parent()->right(), "list is inconsistent");
+
+  bool complicatedSplice = false;
+
+  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->removeChunkReplaceIfNeeded(tc);
+  assert(tc->isFree(), "Chunk should still be free");
+  assert(replacementTL->parent() == NULL ||
+         replacementTL == replacementTL->parent()->left() ||
+         replacementTL == replacementTL->parent()->right(),
+         "list is inconsistent");
+  if (tl == root()) {
+    assert(replacementTL->parent() == NULL, "Incorrectly replacing root");
+    set_root(replacementTL);
+  }
+  debug_only(
+    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();
+      assert(rhl == replacementTL, "Broken head");
+      assert(rtl == replacementTL, "Broken tail");
+      assert(replacementTL->size() == tc->size(),  "Broken size");
+    }
+  )
+
+  // Does the tree need to be repaired?
+  if (replacementTL->count() == 0) {
+    assert(replacementTL->head() == NULL &&
+           replacementTL->tail() == NULL, "list count is incorrect");
+    // Find the replacement node for the (soon to be empty) node being removed.
+    // if we have a single (or no) child, splice child in our stead
+    if (replacementTL->left() == NULL) {
+      // left is NULL so pick right.  right may also be NULL.
+      newTL = replacementTL->right();
+      debug_only(replacementTL->clearRight();)
+    } else if (replacementTL->right() == NULL) {
+      // right is NULL
+      newTL = replacementTL->left();
+      debug_only(replacementTL->clearLeft();)
+    } else {  // we have both children, so, by patriarchal convention,
+              // my replacement is least node in right sub-tree
+      complicatedSplice = true;
+      newTL = removeTreeMinimum(replacementTL->right());
+      assert(newTL != NULL && newTL->left() == NULL &&
+             newTL->right() == NULL, "sub-tree minimum exists");
+    }
+    // newTL is the replacement for the (soon to be empty) node.
+    // newTL may be NULL.
+    // should verify; we just cleanly excised our replacement
+    if (FLSVerifyDictionary) {
+      verifyTree();
+    }
+    // first make newTL my parent's child
+    if ((parentTL = replacementTL->parent()) == NULL) {
+      // newTL should be root
+      assert(tl == root(), "Incorrectly replacing root");
+      set_root(newTL);
+      if (newTL != NULL) {
+        newTL->clearParent();
+      }
+    } else if (parentTL->right() == replacementTL) {
+      // replacementTL is a right child
+      parentTL->setRight(newTL);
+    } else {                                // replacementTL is a left child
+      assert(parentTL->left() == replacementTL, "should be left child");
+      parentTL->setLeft(newTL);
+    }
+    debug_only(replacementTL->clearParent();)
+    if (complicatedSplice) {  // we need newTL to get replacementTL's
+                              // two children
+      assert(newTL != NULL &&
+             newTL->left() == NULL && newTL->right() == NULL,
+            "newTL should not have encumbrances from the past");
+      // we'd like to assert as below:
+      // assert(replacementTL->left() != NULL && replacementTL->right() != NULL,
+      //       "else !complicatedSplice");
+      // ... however, the above assertion is too strong because we aren't
+      // guaranteed that replacementTL->right() is still NULL.
+      // Recall that we removed
+      // the right sub-tree minimum from replacementTL.
+      // That may well have been its right
+      // child! So we'll just assert half of the above:
+      assert(replacementTL->left() != NULL, "else !complicatedSplice");
+      newTL->setLeft(replacementTL->left());
+      newTL->setRight(replacementTL->right());
+      debug_only(
+        replacementTL->clearRight();
+        replacementTL->clearLeft();
+      )
+    }
+    assert(replacementTL->right() == NULL &&
+           replacementTL->left() == NULL &&
+           replacementTL->parent() == NULL,
+        "delete without encumbrances");
+  }
+
+  assert(totalSize() >= retTC->size(), "Incorrect total size");
+  dec_totalSize(retTC->size());     // size book-keeping
+  assert(totalFreeBlocks() > 0, "Incorrect total count");
+  set_totalFreeBlocks(totalFreeBlocks() - 1);
+
+  assert(retTC != NULL, "null chunk?");
+  assert(retTC->prev() == NULL && retTC->next() == NULL,
+         "should return without encumbrances");
+  if (FLSVerifyDictionary) {
+    verifyTree();
+  }
+  assert(!removing_only_chunk || _root == NULL, "root should be NULL");
+  return TreeChunk<Chunk>::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>::removeTreeMinimum(TreeList<Chunk>* 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;
+  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();
+    if (parentTL->left() == curTL) { // curTL is a left child
+      parentTL->setLeft(curTL->right());
+    } else {
+      // If the list tl has no left child, then curTL may be
+      // the right child of parentTL.
+      assert(parentTL->right() == curTL, "should be a right child");
+      parentTL->setRight(curTL->right());
+    }
+  } else {
+    // The only use of this method would not pass the root of the
+    // tree (as indicated by the assertion above that the tree list
+    // has a parent) but the specification does not explicitly exclude the
+    // passing of the root so accomodate it.
+    set_root(NULL);
+  }
+  debug_only(
+    curTL->clearParent();  // Test if this needs to be cleared
+    curTL->clearRight();    // recall, above, left child is already null
+  )
+  // we just excised a (non-root) node, we should still verify all tree invariants
+  if (FLSVerifyDictionary) {
+    verifyTree();
+  }
+  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>::semiSplayStep(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>::insertChunkInTree(Chunk* fc) {
+  TreeList<Chunk> *curTL, *prevTL;
+  size_t size = fc->size();
+
+  assert(size >= BinaryTreeDictionary<Chunk>::min_tree_chunk_size, "too small to be a TreeList<Chunk>");
+  if (FLSVerifyDictionary) {
+    verifyTree();
+  }
+
+  fc->clearNext();
+  fc->linkPrev(NULL);
+
+  // work down from the _root, looking for insertion point
+  for (prevTL = curTL = root(); curTL != NULL;) {
+    if (curTL->size() == size)  // exact match
+      break;
+    prevTL = curTL;
+    if (curTL->size() > size) { // follow left branch
+      curTL = curTL->left();
+    } else {                    // follow right branch
+      assert(curTL->size() < size, "size inconsistency");
+      curTL = curTL->right();
+    }
+  }
+  TreeChunk<Chunk>* tc = TreeChunk<Chunk>::as_TreeChunk(fc);
+  // This chunk is being returned to the binary tree.  Its embedded
+  // TreeList<Chunk> should be unused at this point.
+  tc->initialize();
+  if (curTL != NULL) {          // exact match
+    tc->set_list(curTL);
+    curTL->returnChunkAtTail(tc);
+  } else {                     // need a new node in tree
+    tc->clearNext();
+    tc->linkPrev(NULL);
+    TreeList<Chunk>* newTL = TreeList<Chunk>::as_TreeList(tc);
+    assert(((TreeChunk<Chunk>*)tc)->list() == newTL,
+      "List was not initialized correctly");
+    if (prevTL == NULL) {      // we are the only tree node
+      assert(root() == NULL, "control point invariant");
+      set_root(newTL);
+    } else {                   // insert under prevTL ...
+      if (prevTL->size() < size) {   // am right child
+        assert(prevTL->right() == NULL, "control point invariant");
+        prevTL->setRight(newTL);
+      } else {                       // am left child
+        assert(prevTL->size() > size && prevTL->left() == NULL, "cpt pt inv");
+        prevTL->setLeft(newTL);
+      }
+    }
+  }
+  assert(tc->list() != NULL, "Tree list should be set");
+
+  inc_totalSize(size);
+  // Method 'totalSizeInTree' walks through the every block in the
+  // tree, so it can cause significant performance loss if there are
+  // many blocks in the tree
+  assert(!FLSVerifyDictionary || totalSizeInTree(root()) == totalSize(), "_totalSize inconsistency");
+  set_totalFreeBlocks(totalFreeBlocks() + 1);
+  if (FLSVerifyDictionary) {
+    verifyTree();
+  }
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::maxChunkSize() const {
+  FreeBlockDictionary<Chunk>::verify_par_locked();
+  TreeList<Chunk>* tc = root();
+  if (tc == NULL) return 0;
+  for (; tc->right() != NULL; tc = tc->right());
+  return tc->size();
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::totalListLength(TreeList<Chunk>* tl) const {
+  size_t res;
+  res = tl->count();
+#ifdef ASSERT
+  size_t cnt;
+  Chunk* 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>::totalSizeInTree(TreeList<Chunk>* tl) const {
+  if (tl == NULL)
+    return 0;
+  return (tl->size() * totalListLength(tl)) +
+         totalSizeInTree(tl->left())    +
+         totalSizeInTree(tl->right());
+}
+
+template <class Chunk>
+double BinaryTreeDictionary<Chunk>::sum_of_squared_block_sizes(TreeList<Chunk>* const tl) const {
+  if (tl == NULL) {
+    return 0.0;
+  }
+  double size = (double)(tl->size());
+  double curr = size * size * totalListLength(tl);
+  curr += sum_of_squared_block_sizes(tl->left());
+  curr += sum_of_squared_block_sizes(tl->right());
+  return curr;
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::totalFreeBlocksInTree(TreeList<Chunk>* tl) const {
+  if (tl == NULL)
+    return 0;
+  return totalListLength(tl) +
+         totalFreeBlocksInTree(tl->left()) +
+         totalFreeBlocksInTree(tl->right());
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::numFreeBlocks() const {
+  assert(totalFreeBlocksInTree(root()) == totalFreeBlocks(),
+         "_totalFreeBlocks inconsistency");
+  return totalFreeBlocks();
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::treeHeightHelper(TreeList<Chunk>* tl) const {
+  if (tl == NULL)
+    return 0;
+  return 1 + MAX2(treeHeightHelper(tl->left()),
+                  treeHeightHelper(tl->right()));
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::treeHeight() const {
+  return treeHeightHelper(root());
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::totalNodesHelper(TreeList<Chunk>* tl) const {
+  if (tl == NULL) {
+    return 0;
+  }
+  return 1 + totalNodesHelper(tl->left()) +
+    totalNodesHelper(tl->right());
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::totalNodesInTree(TreeList<Chunk>* tl) const {
+  return totalNodesHelper(root());
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::dictCensusUpdate(size_t size, bool split, bool birth){
+  TreeList<Chunk>* nd = findList(size);
+  if (nd) {
+    if (split) {
+      if (birth) {
+        nd->increment_splitBirths();
+        nd->increment_surplus();
+      }  else {
+        nd->increment_splitDeaths();
+        nd->decrement_surplus();
+      }
+    } else {
+      if (birth) {
+        nd->increment_coalBirths();
+        nd->increment_surplus();
+      } else {
+        nd->increment_coalDeaths();
+        nd->decrement_surplus();
+      }
+    }
+  }
+  // A list for this size may not be found (nd == 0) if
+  //   This is a death where the appropriate list is now
+  //     empty and has been removed from the list.
+  //   This is a birth associated with a LinAB.  The chunk
+  //     for the LinAB is not in the dictionary.
+}
+
+template <class Chunk>
+bool BinaryTreeDictionary<Chunk>::coalDictOverPopulated(size_t size) {
+  if (FLSAlwaysCoalesceLarge) return true;
+
+  TreeList<Chunk>* list_of_size = findList(size);
+  // None of requested size implies overpopulated.
+  return list_of_size == NULL || list_of_size->coalDesired() <= 0 ||
+         list_of_size->count() > list_of_size->coalDesired();
+}
+
+// Closures for walking the binary tree.
+//   do_list() walks the free list in a node applying the closure
+//     to each free chunk in the list
+//   do_tree() walks the nodes in the binary tree applying do_list()
+//     to each list at each node.
+
+template <class Chunk>
+class TreeCensusClosure : public StackObj {
+ protected:
+  virtual void do_list(FreeList<Chunk>* fl) = 0;
+ public:
+  virtual void do_tree(TreeList<Chunk>* tl) = 0;
+};
+
+template <class Chunk>
+class AscendTreeCensusClosure : public TreeCensusClosure<Chunk> {
+ public:
+  void do_tree(TreeList<Chunk>* tl) {
+    if (tl != NULL) {
+      do_tree(tl->left());
+      do_list(tl);
+      do_tree(tl->right());
+    }
+  }
+};
+
+template <class Chunk>
+class DescendTreeCensusClosure : public TreeCensusClosure<Chunk> {
+ public:
+  void do_tree(TreeList<Chunk>* tl) {
+    if (tl != NULL) {
+      do_tree(tl->right());
+      do_list(tl);
+      do_tree(tl->left());
+    }
+  }
+};
+
+// 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> {
+  double _percentage;
+  float _inter_sweep_current;
+  float _inter_sweep_estimate;
+  float _intra_sweep_estimate;
+
+ public:
+  BeginSweepClosure(double p, float inter_sweep_current,
+                              float inter_sweep_estimate,
+                              float intra_sweep_estimate) :
+   _percentage(p),
+   _inter_sweep_current(inter_sweep_current),
+   _inter_sweep_estimate(inter_sweep_estimate),
+   _intra_sweep_estimate(intra_sweep_estimate) { }
+
+  void do_list(FreeList<Chunk>* fl) {
+    double coalSurplusPercent = _percentage;
+    fl->compute_desired(_inter_sweep_current, _inter_sweep_estimate, _intra_sweep_estimate);
+    fl->set_coalDesired((ssize_t)((double)fl->desired() * coalSurplusPercent));
+    fl->set_beforeSweep(fl->count());
+    fl->set_bfrSurp(fl->surplus());
+  }
+};
+
+// 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>
+class TreeSearchClosure : public StackObj {
+ protected:
+  virtual bool do_list(FreeList<Chunk>* fl) = 0;
+ public:
+  virtual bool do_tree(TreeList<Chunk>* tl) = 0;
+};
+
+#if 0 //  Don't need this yet but here for symmetry.
+template <class Chunk>
+class AscendTreeSearchClosure : public TreeSearchClosure {
+ public:
+  bool do_tree(TreeList<Chunk>* tl) {
+    if (tl != NULL) {
+      if (do_tree(tl->left())) return true;
+      if (do_list(tl)) return true;
+      if (do_tree(tl->right())) return true;
+    }
+    return false;
+  }
+};
+#endif
+
+template <class Chunk>
+class DescendTreeSearchClosure : public TreeSearchClosure<Chunk> {
+ public:
+  bool do_tree(TreeList<Chunk>* tl) {
+    if (tl != NULL) {
+      if (do_tree(tl->right())) return true;
+      if (do_list(tl)) return true;
+      if (do_tree(tl->left())) return true;
+    }
+    return false;
+  }
+};
+
+// Searches the tree for a chunk that ends at the
+// specified address.
+template <class Chunk>
+class EndTreeSearchClosure : public DescendTreeSearchClosure<Chunk> {
+  HeapWord* _target;
+  Chunk* _found;
+
+ public:
+  EndTreeSearchClosure(HeapWord* target) : _target(target), _found(NULL) {}
+  bool do_list(FreeList<Chunk>* fl) {
+    Chunk* item = fl->head();
+    while (item != NULL) {
+      if (item->end() == _target) {
+        _found = item;
+        return true;
+      }
+      item = item->next();
+    }
+    return false;
+  }
+  Chunk* found() { return _found; }
+};
+
+template <class Chunk>
+Chunk* BinaryTreeDictionary<Chunk>::find_chunk_ends_at(HeapWord* target) const {
+  EndTreeSearchClosure<Chunk> 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>::beginSweepDictCensus(double coalSurplusPercent,
+  float inter_sweep_current, float inter_sweep_estimate, float intra_sweep_estimate) {
+  BeginSweepClosure<Chunk> bsc(coalSurplusPercent, inter_sweep_current,
+                                            inter_sweep_estimate,
+                                            intra_sweep_estimate);
+  bsc.do_tree(root());
+}
+
+// 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> {
+   public:
+  void do_list(FreeList<Chunk>* fl) {
+    fl->set_returnedBytes(0);
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::initializeDictReturnedBytes() {
+  InitializeDictReturnedBytesClosure<Chunk> idrb;
+  idrb.do_tree(root());
+}
+
+template <class Chunk>
+class ReturnedBytesClosure : public AscendTreeCensusClosure<Chunk> {
+  size_t _dictReturnedBytes;
+ public:
+  ReturnedBytesClosure() { _dictReturnedBytes = 0; }
+  void do_list(FreeList<Chunk>* fl) {
+    _dictReturnedBytes += fl->returnedBytes();
+  }
+  size_t dictReturnedBytes() { return _dictReturnedBytes; }
+};
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::sumDictReturnedBytes() {
+  ReturnedBytesClosure<Chunk> rbc;
+  rbc.do_tree(root());
+
+  return rbc.dictReturnedBytes();
+}
+
+// Count the number of entries in the tree.
+template <class Chunk>
+class treeCountClosure : public DescendTreeCensusClosure<Chunk> {
+ public:
+  uint count;
+  treeCountClosure(uint c) { count = c; }
+  void do_list(FreeList<Chunk>* fl) {
+    count++;
+  }
+};
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::totalCount() {
+  treeCountClosure<Chunk> 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> {
+  double percentage;
+ public:
+  setTreeSurplusClosure(double v) { percentage = v; }
+  void do_list(FreeList<Chunk>* fl) {
+    double splitSurplusPercent = percentage;
+    fl->set_surplus(fl->count() -
+                   (ssize_t)((double)fl->desired() * splitSurplusPercent));
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::setTreeSurplus(double splitSurplusPercent) {
+  setTreeSurplusClosure<Chunk> sts(splitSurplusPercent);
+  sts.do_tree(root());
+}
+
+// Set hints for the lists in the tree.
+template <class Chunk>
+class setTreeHintsClosure : public DescendTreeCensusClosure<Chunk> {
+  size_t hint;
+ public:
+  setTreeHintsClosure(size_t v) { hint = v; }
+  void do_list(FreeList<Chunk>* fl) {
+    fl->set_hint(hint);
+    assert(fl->hint() == 0 || fl->hint() > fl->size(),
+      "Current hint is inconsistent");
+    if (fl->surplus() > 0) {
+      hint = fl->size();
+    }
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::setTreeHints(void) {
+  setTreeHintsClosure<Chunk> 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) {
+    fl->set_prevSweep(fl->count());
+    fl->set_coalBirths(0);
+    fl->set_coalDeaths(0);
+    fl->set_splitBirths(0);
+    fl->set_splitDeaths(0);
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::clearTreeCensus(void) {
+  clearTreeCensusClosure<Chunk> ctc;
+  ctc.do_tree(root());
+}
+
+// Do reporting and post sweep clean up.
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::endSweepDictCensus(double splitSurplusPercent) {
+  // Does walking the tree 3 times hurt?
+  setTreeSurplus(splitSurplusPercent);
+  setTreeHints();
+  if (PrintGC && Verbose) {
+    reportStatistics();
+  }
+  clearTreeCensus();
+}
+
+// Print summary statistics
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::reportStatistics() const {
+  FreeBlockDictionary<Chunk>::verify_par_locked();
+  gclog_or_tty->print("Statistics for BinaryTreeDictionary:\n"
+         "------------------------------------\n");
+  size_t totalSize = totalChunkSize(debug_only(NULL));
+  size_t    freeBlocks = numFreeBlocks();
+  gclog_or_tty->print("Total Free Space: %d\n", totalSize);
+  gclog_or_tty->print("Max   Chunk Size: %d\n", maxChunkSize());
+  gclog_or_tty->print("Number of Blocks: %d\n", freeBlocks);
+  if (freeBlocks > 0) {
+    gclog_or_tty->print("Av.  Block  Size: %d\n", totalSize/freeBlocks);
+  }
+  gclog_or_tty->print("Tree      Height: %d\n", treeHeight());
+}
+
+// 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> {
+  int _print_line;
+  size_t _totalFree;
+  FreeList<Chunk> _total;
+
+ public:
+  PrintTreeCensusClosure() {
+    _print_line = 0;
+    _totalFree = 0;
+  }
+  FreeList<Chunk>* total() { return &_total; }
+  size_t totalFree() { return _totalFree; }
+  void do_list(FreeList<Chunk>* fl) {
+    if (++_print_line >= 40) {
+      FreeList<Chunk>::print_labels_on(gclog_or_tty, "size");
+      _print_line = 0;
+    }
+    fl->print_on(gclog_or_tty);
+    _totalFree +=            fl->count()            * fl->size()        ;
+    total()->set_count(      total()->count()       + fl->count()      );
+    total()->set_bfrSurp(    total()->bfrSurp()     + fl->bfrSurp()    );
+    total()->set_surplus(    total()->splitDeaths() + fl->surplus()    );
+    total()->set_desired(    total()->desired()     + fl->desired()    );
+    total()->set_prevSweep(  total()->prevSweep()   + fl->prevSweep()  );
+    total()->set_beforeSweep(total()->beforeSweep() + fl->beforeSweep());
+    total()->set_coalBirths( total()->coalBirths()  + fl->coalBirths() );
+    total()->set_coalDeaths( total()->coalDeaths()  + fl->coalDeaths() );
+    total()->set_splitBirths(total()->splitBirths() + fl->splitBirths());
+    total()->set_splitDeaths(total()->splitDeaths() + fl->splitDeaths());
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::printDictCensus(void) const {
+
+  gclog_or_tty->print("\nBinaryTree\n");
+  FreeList<Chunk>::print_labels_on(gclog_or_tty, "size");
+  PrintTreeCensusClosure<Chunk> ptc;
+  ptc.do_tree(root());
+
+  FreeList<Chunk>* total = ptc.total();
+  FreeList<Chunk>::print_labels_on(gclog_or_tty, " ");
+  total->print_on(gclog_or_tty, "TOTAL\t");
+  gclog_or_tty->print(
+              "totalFree(words): " SIZE_FORMAT_W(16)
+              " growth: %8.5f  deficit: %8.5f\n",
+              ptc.totalFree(),
+              (double)(total->splitBirths() + total->coalBirths()
+                     - total->splitDeaths() - total->coalDeaths())
+              /(total->prevSweep() != 0 ? (double)total->prevSweep() : 1.0),
+             (double)(total->desired() - total->count())
+             /(total->desired() != 0 ? (double)total->desired() : 1.0));
+}
+
+template <class Chunk>
+class PrintFreeListsClosure : public AscendTreeCensusClosure<Chunk> {
+  outputStream* _st;
+  int _print_line;
+
+ public:
+  PrintFreeListsClosure(outputStream* st) {
+    _st = st;
+    _print_line = 0;
+  }
+  void do_list(FreeList<Chunk>* fl) {
+    if (++_print_line >= 40) {
+      FreeList<Chunk>::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;
+         fc = fc->next()) {
+      _st->print_cr("\t[" PTR_FORMAT "," PTR_FORMAT ")  %s",
+                    fc, (HeapWord*)fc + sz,
+                    fc->cantCoalesce() ? "\t CC" : "");
+    }
+  }
+};
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::print_free_lists(outputStream* st) const {
+
+  FreeList<Chunk>::print_labels_on(st, "size");
+  PrintFreeListsClosure<Chunk> pflc(st);
+  pflc.do_tree(root());
+}
+
+// Verify the following tree invariants:
+// . _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>::verifyTree() const {
+  guarantee(root() == NULL || totalFreeBlocks() == 0 ||
+    totalSize() != 0, "_totalSize should't be 0?");
+  guarantee(root() == NULL || root()->parent() == NULL, "_root shouldn't have parent");
+  verifyTreeHelper(root());
+}
+
+template <class Chunk>
+size_t BinaryTreeDictionary<Chunk>::verifyPrevFreePtrs(TreeList<Chunk>* tl) {
+  size_t ct = 0;
+  for (Chunk* curFC = tl->head(); curFC != NULL; curFC = curFC->next()) {
+    ct++;
+    assert(curFC->prev() == NULL || curFC->prev()->isFree(),
+      "Chunk should be free");
+  }
+  return ct;
+}
+
+// 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>::verifyTreeHelper(TreeList<Chunk>* tl) const {
+  if (tl == NULL)
+    return;
+  guarantee(tl->size() != 0, "A list must has a size");
+  guarantee(tl->left()  == NULL || tl->left()->parent()  == tl,
+         "parent<-/->left");
+  guarantee(tl->right() == NULL || tl->right()->parent() == tl,
+         "parent<-/->right");;
+  guarantee(tl->left() == NULL  || tl->left()->size()    <  tl->size(),
+         "parent !> left");
+  guarantee(tl->right() == NULL || tl->right()->size()   >  tl->size(),
+         "parent !< left");
+  guarantee(tl->head() == NULL || tl->head()->isFree(), "!Free");
+  guarantee(tl->head() == NULL || tl->head_as_TreeChunk()->list() == tl,
+    "list inconsistency");
+  guarantee(tl->count() > 0 || (tl->head() == NULL && tl->tail() == NULL),
+    "list count is inconsistent");
+  guarantee(tl->count() > 1 || tl->head() == tl->tail(),
+    "list is incorrectly constructed");
+  size_t count = verifyPrevFreePtrs(tl);
+  guarantee(count == (size_t)tl->count(), "Node count is incorrect");
+  if (tl->head() != NULL) {
+    tl->head_as_TreeChunk()->verifyTreeChunkList();
+  }
+  verifyTreeHelper(tl->left());
+  verifyTreeHelper(tl->right());
+}
+
+template <class Chunk>
+void BinaryTreeDictionary<Chunk>::verify() const {
+  verifyTree();
+  guarantee(totalSize() == totalSizeInTree(root()), "Total Size inconsistency");
+}
+
+#ifndef SERIALGC
+// Explicitly instantiate these types for FreeChunk.
+template class BinaryTreeDictionary<FreeChunk>;
+template class TreeChunk<FreeChunk>;
+template class TreeList<FreeChunk>;
+#endif // SERIALGC