Mercurial > hg > truffle

comparison src/share/vm/gc_implementation/concurrentMarkSweep/binaryTreeDictionary.hpp @ 0:a61af66fc99e jdk7-b24

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children c70a245cad3a
comparison
equal deleted inserted replaced
-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2001-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 /*
26 * A binary tree based search structure for free blocks.
27 * This is currently used in the Concurrent Mark&Sweep implementation.
28 */
29
30 // A TreeList is a FreeList which can be used to maintain a
31 // binary tree of free lists.
32
33 class TreeChunk;
34 class BinaryTreeDictionary;
35 class AscendTreeCensusClosure;
36 class DescendTreeCensusClosure;
37 class DescendTreeSearchClosure;
38
39 class TreeList: public FreeList {
40 friend class TreeChunk;
41 friend class BinaryTreeDictionary;
42 friend class AscendTreeCensusClosure;
43 friend class DescendTreeCensusClosure;
44 friend class DescendTreeSearchClosure;
45 TreeList* _parent;
46 TreeList* _left;
47 TreeList* _right;
48
49 protected:
50 TreeList* parent() const { return _parent; }
51 TreeList* left() const { return _left; }
52 TreeList* right() const { return _right; }
53
54 // Accessors for links in tree.
55
56 void setLeft(TreeList* tl) {
57 _left = tl;
58 if (tl != NULL)
59 tl->setParent(this);
60 }
61 void setRight(TreeList* tl) {
62 _right = tl;
63 if (tl != NULL)
64 tl->setParent(this);
65 }
66 void setParent(TreeList* tl) { _parent = tl; }
67
68 void clearLeft() { _left = NULL; }
69 void clearRight() { _right = NULL; }
70 void clearParent() { _parent = NULL; }
71 void initialize() { clearLeft(); clearRight(), clearParent(); }
72
73 // For constructing a TreeList from a Tree chunk or
74 // address and size.
75 static TreeList* as_TreeList(TreeChunk* tc);
76 static TreeList* as_TreeList(HeapWord* addr, size_t size);
77
78 // Returns the head of the free list as a pointer to a TreeChunk.
79 TreeChunk* head_as_TreeChunk();
80
81 // Returns the first available chunk in the free list as a pointer
82 // to a TreeChunk.
83 TreeChunk* first_available();
84
85 // removeChunkReplaceIfNeeded() removes the given "tc" from the TreeList.
86 // If "tc" is the first chunk in the list, it is also the
87 // TreeList that is the node in the tree. removeChunkReplaceIfNeeded()
88 // returns the possibly replaced TreeList* for the node in
89 // the tree. It also updates the parent of the original
90 // node to point to the new node.
91 TreeList* removeChunkReplaceIfNeeded(TreeChunk* tc);
92 // See FreeList.
93 void returnChunkAtHead(TreeChunk* tc);
94 void returnChunkAtTail(TreeChunk* tc);
95 };
96
97 // A TreeChunk is a subclass of a FreeChunk that additionally
98 // maintains a pointer to the free list on which it is currently
99 // linked.
100 // A TreeChunk is also used as a node in the binary tree. This
101 // allows the binary tree to be maintained without any additional
102 // storage (the free chunks are used). In a binary tree the first
103 // chunk in the free list is also the tree node. Note that the
104 // TreeChunk has an embedded TreeList for this purpose. Because
105 // the first chunk in the list is distinguished in this fashion
106 // (also is the node in the tree), it is the last chunk to be found
107 // on the free list for a node in the tree and is only removed if
108 // it is the last chunk on the free list.
109
110 class TreeChunk : public FreeChunk {
111 friend class TreeList;
112 TreeList* _list;
113 TreeList _embedded_list; // if non-null, this chunk is on _list
114 protected:
115 TreeList* embedded_list() const { return (TreeList*) &_embedded_list; }
116 void set_embedded_list(TreeList* v) { _embedded_list = *v; }
117 public:
118 TreeList* list() { return _list; }
119 void set_list(TreeList* v) { _list = v; }
120 static TreeChunk* as_TreeChunk(FreeChunk* fc);
121 // Initialize fields in a TreeChunk that should be
122 // initialized when the TreeChunk is being added to
123 // a free list in the tree.
124 void initialize() { embedded_list()->initialize(); }
125
126 // debugging
127 void verifyTreeChunkList() const;
128 };
129
130 const size_t MIN_TREE_CHUNK_SIZE = sizeof(TreeChunk)/HeapWordSize;
131
132 class BinaryTreeDictionary: public FreeBlockDictionary {
133 bool _splay;
134 size_t _totalSize;
135 size_t _totalFreeBlocks;
136 TreeList* _root;
137
138 // private accessors
139 bool splay() const { return _splay; }
140 void set_splay(bool v) { _splay = v; }
141 size_t totalSize() const { return _totalSize; }
142 void set_totalSize(size_t v) { _totalSize = v; }
143 virtual void inc_totalSize(size_t v);
144 virtual void dec_totalSize(size_t v);
145 size_t totalFreeBlocks() const { return _totalFreeBlocks; }
146 void set_totalFreeBlocks(size_t v) { _totalFreeBlocks = v; }
147 TreeList* root() const { return _root; }
148 void set_root(TreeList* v) { _root = v; }
149
150 // Remove a chunk of size "size" or larger from the tree and
151 // return it. If the chunk
152 // is the last chunk of that size, remove the node for that size
153 // from the tree.
154 TreeChunk* getChunkFromTree(size_t size, Dither dither, bool splay);
155 // Return a list of the specified size or NULL from the tree.
156 // The list is not removed from the tree.
157 TreeList* findList (size_t size) const;
158 // Remove this chunk from the tree. If the removal results
159 // in an empty list in the tree, remove the empty list.
160 TreeChunk* removeChunkFromTree(TreeChunk* tc);
161 // Remove the node in the trees starting at tl that has the
162 // minimum value and return it. Repair the tree as needed.
163 TreeList* removeTreeMinimum(TreeList* tl);
164 void semiSplayStep(TreeList* tl);
165 // Add this free chunk to the tree.
166 void insertChunkInTree(FreeChunk* freeChunk);
167 public:
168 void verifyTree() const;
169 // verify that the given chunk is in the tree.
170 bool verifyChunkInFreeLists(FreeChunk* tc) const;
171 private:
172 void verifyTreeHelper(TreeList* tl) const;
173 static size_t verifyPrevFreePtrs(TreeList* tl);
174
175 // Returns the total number of chunks in the list.
176 size_t totalListLength(TreeList* tl) const;
177 // Returns the total number of words in the chunks in the tree
178 // starting at "tl".
179 size_t totalSizeInTree(TreeList* tl) const;
180 // Returns the sum of the square of the size of each block
181 // in the tree starting at "tl".
182 double sum_of_squared_block_sizes(TreeList* const tl) const;
183 // Returns the total number of free blocks in the tree starting
184 // at "tl".
185 size_t totalFreeBlocksInTree(TreeList* tl) const;
186 size_t numFreeBlocks() const;
187 size_t treeHeight() const;
188 size_t treeHeightHelper(TreeList* tl) const;
189 size_t totalNodesInTree(TreeList* tl) const;
190 size_t totalNodesHelper(TreeList* tl) const;
191
192 public:
193 // Constructor
194 BinaryTreeDictionary(MemRegion mr, bool splay = false);
195
196 // Reset the dictionary to the initial conditions with
197 // a single free chunk.
198 void reset(MemRegion mr);
199 void reset(HeapWord* addr, size_t size);
200 // Reset the dictionary to be empty.
201 void reset();
202
203 // Return a chunk of size "size" or greater from
204 // the tree.
205 // want a better dynamic splay strategy for the future.
206 FreeChunk* getChunk(size_t size, Dither dither) {
207 verify_par_locked();
208 FreeChunk* res = getChunkFromTree(size, dither, splay());
209 assert(res == NULL || res->isFree(),
210 "Should be returning a free chunk");
211 return res;
212 }
213
214 void returnChunk(FreeChunk* chunk) {
215 verify_par_locked();
216 insertChunkInTree(chunk);
217 }
218
219 void removeChunk(FreeChunk* chunk) {
220 verify_par_locked();
221 removeChunkFromTree((TreeChunk*)chunk);
222 assert(chunk->isFree(), "Should still be a free chunk");
223 }
224
225 size_t maxChunkSize() const;
226 size_t totalChunkSize(debug_only(const Mutex* lock)) const {
227 debug_only(
228 if (lock != NULL && lock->owned_by_self()) {
229 assert(totalSizeInTree(root()) == totalSize(),
230 "_totalSize inconsistency");
231 }
232 )
233 return totalSize();
234 }
235
236 size_t minSize() const {
237 return MIN_TREE_CHUNK_SIZE;
238 }
239
240 double sum_of_squared_block_sizes() const {
241 return sum_of_squared_block_sizes(root());
242 }
243
244 FreeChunk* find_chunk_ends_at(HeapWord* target) const;
245
246 // Find the list with size "size" in the binary tree and update
247 // the statistics in the list according to "split" (chunk was
248 // split or coalesce) and "birth" (chunk was added or removed).
249 void dictCensusUpdate(size_t size, bool split, bool birth);
250 // Return true if the dictionary is overpopulated (more chunks of
251 // this size than desired) for size "size".
252 bool coalDictOverPopulated(size_t size);
253 // Methods called at the beginning of a sweep to prepare the
254 // statistics for the sweep.
255 void beginSweepDictCensus(double coalSurplusPercent,
256 float sweep_current,
257 float sweep_estimate);
258 // Methods called after the end of a sweep to modify the
259 // statistics for the sweep.
260 void endSweepDictCensus(double splitSurplusPercent);
261 // Return the largest free chunk in the tree.
262 FreeChunk* findLargestDict() const;
263 // Accessors for statistics
264 void setTreeSurplus(double splitSurplusPercent);
265 void setTreeHints(void);
266 // Reset statistics for all the lists in the tree.
267 void clearTreeCensus(void);
268 // Print the statistcis for all the lists in the tree. Also may
269 // print out summaries.
270 void printDictCensus(void) const;
271
272 // For debugging. Returns the sum of the _returnedBytes for
273 // all lists in the tree.
274 size_t sumDictReturnedBytes() PRODUCT_RETURN0;
275 // Sets the _returnedBytes for all the lists in the tree to zero.
276 void initializeDictReturnedBytes() PRODUCT_RETURN;
277 // For debugging. Return the total number of chunks in the dictionary.
278 size_t totalCount() PRODUCT_RETURN0;
279
280 void reportStatistics() const;
281
282 void verify() const;
283 };