--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/binaryTreeDictionary.hpp Thu Mar 29 19:46:24 2012 -0700
@@ -0,0 +1,329 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP
+#define SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP
+
+#include "memory/freeBlockDictionary.hpp"
+#include "memory/freeList.hpp"
+
+/*
+ * A binary tree based search structure for free blocks.
+ * This is currently used in the Concurrent Mark&Sweep implementation, but
+ * will be used for free block management for metadata.
+ */
+
+// 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>
+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>;
+
+ TreeList<Chunk>* _parent;
+ TreeList<Chunk>* _left;
+ TreeList<Chunk>* _right;
+
+ protected:
+ TreeList<Chunk>* parent() const { return _parent; }
+ TreeList<Chunk>* left() const { return _left; }
+ TreeList<Chunk>* right() const { return _right; }
+
+ // Wrapper on call to base class, to get the template to compile.
+ Chunk* head() const { return FreeList<Chunk>::head(); }
+ Chunk* tail() const { return FreeList<Chunk>::tail(); }
+ void set_head(Chunk* head) { FreeList<Chunk>::set_head(head); }
+ void set_tail(Chunk* tail) { FreeList<Chunk>::set_tail(tail); }
+
+ size_t size() const { return FreeList<Chunk>::size(); }
+
+ // Accessors for links in tree.
+
+ void setLeft(TreeList<Chunk>* tl) {
+ _left = tl;
+ if (tl != NULL)
+ tl->setParent(this);
+ }
+ void setRight(TreeList<Chunk>* tl) {
+ _right = tl;
+ if (tl != NULL)
+ tl->setParent(this);
+ }
+ void setParent(TreeList<Chunk>* tl) { _parent = tl; }
+
+ void clearLeft() { _left = NULL; }
+ void clearRight() { _right = NULL; }
+ void clearParent() { _parent = NULL; }
+ void initialize() { clearLeft(); clearRight(), clearParent(); }
+
+ // 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);
+
+ // Returns the head of the free list as a pointer to a TreeChunk.
+ TreeChunk<Chunk>* head_as_TreeChunk();
+
+ // Returns the first available chunk in the free list as a pointer
+ // to a TreeChunk.
+ TreeChunk<Chunk>* 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();
+
+ // removeChunkReplaceIfNeeded() removes the given "tc" from the TreeList.
+ // If "tc" is the first chunk in the list, it is also the
+ // TreeList that is the node in the tree. removeChunkReplaceIfNeeded()
+ // 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>* removeChunkReplaceIfNeeded(TreeChunk<Chunk>* tc);
+ // See FreeList.
+ void returnChunkAtHead(TreeChunk<Chunk>* tc);
+ void returnChunkAtTail(TreeChunk<Chunk>* tc);
+};
+
+// A TreeChunk is a subclass of a Chunk that additionally
+// maintains a pointer to the free list on which it is currently
+// linked.
+// A TreeChunk is also used as a node in the binary tree. This
+// allows the binary tree to be maintained without any additional
+// storage (the free chunks are used). In a binary tree the first
+// chunk in the free list is also the tree node. Note that the
+// TreeChunk has an embedded TreeList for this purpose. Because
+// the first chunk in the list is distinguished in this fashion
+// (also is the node in the tree), it is the last chunk to be found
+// 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
+ protected:
+ TreeList<Chunk>* embedded_list() const { return (TreeList<Chunk>*) &_embedded_list; }
+ void set_embedded_list(TreeList<Chunk>* 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);
+ // 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(); }
+
+ // debugging
+ void verifyTreeChunkList() const;
+};
+
+
+template <class Chunk>
+class BinaryTreeDictionary: public FreeBlockDictionary<Chunk> {
+ friend class VMStructs;
+ bool _splay;
+ size_t _totalSize;
+ size_t _totalFreeBlocks;
+ TreeList<Chunk>* _root;
+ bool _adaptive_freelists;
+
+ // private accessors
+ bool splay() const { return _splay; }
+ void set_splay(bool v) { _splay = v; }
+ void set_totalSize(size_t v) { _totalSize = v; }
+ virtual void inc_totalSize(size_t v);
+ virtual void dec_totalSize(size_t v);
+ size_t totalFreeBlocks() const { return _totalFreeBlocks; }
+ void set_totalFreeBlocks(size_t v) { _totalFreeBlocks = v; }
+ TreeList<Chunk>* root() const { return _root; }
+ void set_root(TreeList<Chunk>* v) { _root = v; }
+ bool adaptive_freelists() { return _adaptive_freelists; }
+
+ // This field is added and can be set to point to the
+ // the Mutex used to synchronize access to the
+ // dictionary so that assertion checking can be done.
+ // For example it is set to point to _parDictionaryAllocLock.
+ NOT_PRODUCT(Mutex* _lock;)
+
+ // Remove a chunk of size "size" or larger from the tree and
+ // return it. If the chunk
+ // is the last chunk of that size, remove the node for that size
+ // from the tree.
+ TreeChunk<Chunk>* getChunkFromTree(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither, bool splay);
+ // Return a list of the specified size or NULL from the tree.
+ // The list is not removed from the tree.
+ TreeList<Chunk>* findList (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>* removeChunkFromTree(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>* removeTreeMinimum(TreeList<Chunk>* tl);
+ void semiSplayStep(TreeList<Chunk>* tl);
+ // Add this free chunk to the tree.
+ void insertChunkInTree(Chunk* freeChunk);
+ public:
+
+ static const size_t min_tree_chunk_size = sizeof(TreeChunk<Chunk>)/HeapWordSize;
+
+ void verifyTree() const;
+ // verify that the given chunk is in the tree.
+ bool verifyChunkInFreeLists(Chunk* tc) const;
+ private:
+ void verifyTreeHelper(TreeList<Chunk>* tl) const;
+ static size_t verifyPrevFreePtrs(TreeList<Chunk>* tl);
+
+ // Returns the total number of chunks in the list.
+ size_t totalListLength(TreeList<Chunk>* tl) const;
+ // Returns the total number of words in the chunks in the tree
+ // starting at "tl".
+ size_t totalSizeInTree(TreeList<Chunk>* 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;
+ // Returns the total number of free blocks in the tree starting
+ // at "tl".
+ size_t totalFreeBlocksInTree(TreeList<Chunk>* tl) const;
+ size_t numFreeBlocks() const;
+ size_t treeHeight() const;
+ size_t treeHeightHelper(TreeList<Chunk>* tl) const;
+ size_t totalNodesInTree(TreeList<Chunk>* tl) const;
+ size_t totalNodesHelper(TreeList<Chunk>* tl) const;
+
+ public:
+ // Constructor
+ BinaryTreeDictionary(bool adaptive_freelists, bool splay = false);
+ BinaryTreeDictionary(MemRegion mr, bool adaptive_freelists, bool splay = false);
+
+ // Public accessors
+ size_t totalSize() const { return _totalSize; }
+
+ // Reset the dictionary to the initial conditions with
+ // a single free chunk.
+ void reset(MemRegion mr);
+ void reset(HeapWord* addr, size_t size);
+ // Reset the dictionary to be empty.
+ void reset();
+
+ // Return a chunk of size "size" or greater from
+ // the tree.
+ // want a better dynamic splay strategy for the future.
+ Chunk* getChunk(size_t size, enum FreeBlockDictionary<Chunk>::Dither dither) {
+ FreeBlockDictionary<Chunk>::verify_par_locked();
+ Chunk* res = getChunkFromTree(size, dither, splay());
+ assert(res == NULL || res->isFree(),
+ "Should be returning a free chunk");
+ return res;
+ }
+
+ void returnChunk(Chunk* chunk) {
+ FreeBlockDictionary<Chunk>::verify_par_locked();
+ insertChunkInTree(chunk);
+ }
+
+ void removeChunk(Chunk* chunk) {
+ FreeBlockDictionary<Chunk>::verify_par_locked();
+ removeChunkFromTree((TreeChunk<Chunk>*)chunk);
+ assert(chunk->isFree(), "Should still be a free chunk");
+ }
+
+ size_t maxChunkSize() const;
+ size_t totalChunkSize(debug_only(const Mutex* lock)) const {
+ debug_only(
+ if (lock != NULL && lock->owned_by_self()) {
+ assert(totalSizeInTree(root()) == totalSize(),
+ "_totalSize inconsistency");
+ }
+ )
+ return totalSize();
+ }
+
+ size_t minSize() const {
+ return min_tree_chunk_size;
+ }
+
+ double sum_of_squared_block_sizes() const {
+ return sum_of_squared_block_sizes(root());
+ }
+
+ Chunk* 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 dictCensusUpdate(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 coalDictOverPopulated(size_t size);
+ // Methods called at the beginning of a sweep to prepare the
+ // statistics for the sweep.
+ void beginSweepDictCensus(double coalSurplusPercent,
+ float inter_sweep_current,
+ float inter_sweep_estimate,
+ float intra_sweep_estimate);
+ // Methods called after the end of a sweep to modify the
+ // statistics for the sweep.
+ void endSweepDictCensus(double splitSurplusPercent);
+ // Return the largest free chunk in the tree.
+ Chunk* findLargestDict() const;
+ // Accessors for statistics
+ void setTreeSurplus(double splitSurplusPercent);
+ void setTreeHints(void);
+ // Reset statistics for all the lists in the tree.
+ void clearTreeCensus(void);
+ // Print the statistcis for all the lists in the tree. Also may
+ // print out summaries.
+ void printDictCensus(void) const;
+ void print_free_lists(outputStream* st) const;
+
+ // For debugging. Returns the sum of the _returnedBytes for
+ // all lists in the tree.
+ size_t sumDictReturnedBytes() PRODUCT_RETURN0;
+ // Sets the _returnedBytes for all the lists in the tree to zero.
+ void initializeDictReturnedBytes() PRODUCT_RETURN;
+ // For debugging. Return the total number of chunks in the dictionary.
+ size_t totalCount() PRODUCT_RETURN0;
+
+ void reportStatistics() const;
+
+ void verify() const;
+};
+
+#endif // SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP