1 /* 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP 26 #define SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP 27 28 #include "memory/freeBlockDictionary.hpp" 29 #include "memory/freeList.hpp" 30 31 /* 32 * A binary tree based search structure for free blocks. 33 * This is currently used in the Concurrent Mark&Sweep implementation, but 34 * will be used for free block management for metadata. 35 */ 36 37 // A TreeList is a FreeList which can be used to maintain a 38 // binary tree of free lists. 39 40 template <class Chunk_t, class FreeList_t> class TreeChunk; 41 template <class Chunk_t, class FreeList_t> class BinaryTreeDictionary; 42 template <class Chunk_t, class FreeList_t> class AscendTreeCensusClosure; 43 template <class Chunk_t, class FreeList_t> class DescendTreeCensusClosure; 44 template <class Chunk_t, class FreeList_t> class DescendTreeSearchClosure; 45 46 class FreeChunk; 47 template <class> class AdaptiveFreeList; 48 typedef BinaryTreeDictionary<FreeChunk, AdaptiveFreeList<FreeChunk> > AFLBinaryTreeDictionary; 49 50 template <class Chunk_t, class FreeList_t> 51 class TreeList : public FreeList_t { 52 friend class TreeChunk<Chunk_t, FreeList_t>; 53 friend class BinaryTreeDictionary<Chunk_t, FreeList_t>; 54 friend class AscendTreeCensusClosure<Chunk_t, FreeList_t>; 55 friend class DescendTreeCensusClosure<Chunk_t, FreeList_t>; 56 friend class DescendTreeSearchClosure<Chunk_t, FreeList_t>; 57 58 TreeList<Chunk_t, FreeList_t>* _parent; 59 TreeList<Chunk_t, FreeList_t>* _left; 60 TreeList<Chunk_t, FreeList_t>* _right; 61 62 protected: 63 64 TreeList<Chunk_t, FreeList_t>* parent() const { return _parent; } 65 TreeList<Chunk_t, FreeList_t>* left() const { return _left; } 66 TreeList<Chunk_t, FreeList_t>* right() const { return _right; } 67 68 // Wrapper on call to base class, to get the template to compile. 69 Chunk_t* head() const { return FreeList_t::head(); } 70 Chunk_t* tail() const { return FreeList_t::tail(); } 71 void set_head(Chunk_t* head) { FreeList_t::set_head(head); } 72 void set_tail(Chunk_t* tail) { FreeList_t::set_tail(tail); } 73 74 size_t size() const { return FreeList_t::size(); } 75 76 // Accessors for links in tree. 77 78 void set_left(TreeList<Chunk_t, FreeList_t>* tl) { 79 _left = tl; 80 if (tl != NULL) 81 tl->set_parent(this); 82 } 83 void set_right(TreeList<Chunk_t, FreeList_t>* tl) { 84 _right = tl; 85 if (tl != NULL) 86 tl->set_parent(this); 87 } 88 void set_parent(TreeList<Chunk_t, FreeList_t>* tl) { _parent = tl; } 89 90 void clear_left() { _left = NULL; } 91 void clear_right() { _right = NULL; } 92 void clear_parent() { _parent = NULL; } 93 void initialize() { clear_left(); clear_right(), clear_parent(); FreeList_t::initialize(); } 94 95 // For constructing a TreeList from a Tree chunk or 96 // address and size. 97 TreeList(); 98 static TreeList<Chunk_t, FreeList_t>* 99 as_TreeList(TreeChunk<Chunk_t, FreeList_t>* tc); 100 static TreeList<Chunk_t, FreeList_t>* as_TreeList(HeapWord* addr, size_t size); 101 102 // Returns the head of the free list as a pointer to a TreeChunk. 103 TreeChunk<Chunk_t, FreeList_t>* head_as_TreeChunk(); 104 105 // Returns the first available chunk in the free list as a pointer 106 // to a TreeChunk. 107 TreeChunk<Chunk_t, FreeList_t>* first_available(); 108 109 // Returns the block with the largest heap address amongst 110 // those in the list for this size; potentially slow and expensive, 111 // use with caution! 112 TreeChunk<Chunk_t, FreeList_t>* largest_address(); 113 114 TreeList<Chunk_t, FreeList_t>* get_better_list( 115 BinaryTreeDictionary<Chunk_t, FreeList_t>* dictionary); 116 117 // remove_chunk_replace_if_needed() removes the given "tc" from the TreeList. 118 // If "tc" is the first chunk in the list, it is also the 119 // TreeList that is the node in the tree. remove_chunk_replace_if_needed() 120 // returns the possibly replaced TreeList* for the node in 121 // the tree. It also updates the parent of the original 122 // node to point to the new node. 123 TreeList<Chunk_t, FreeList_t>* remove_chunk_replace_if_needed(TreeChunk<Chunk_t, FreeList_t>* tc); 124 // See FreeList. 125 void return_chunk_at_head(TreeChunk<Chunk_t, FreeList_t>* tc); 126 void return_chunk_at_tail(TreeChunk<Chunk_t, FreeList_t>* tc); 127 }; 128 129 // A TreeChunk is a subclass of a Chunk that additionally 130 // maintains a pointer to the free list on which it is currently 131 // linked. 132 // A TreeChunk is also used as a node in the binary tree. This 133 // allows the binary tree to be maintained without any additional 134 // storage (the free chunks are used). In a binary tree the first 135 // chunk in the free list is also the tree node. Note that the 136 // TreeChunk has an embedded TreeList for this purpose. Because 137 // the first chunk in the list is distinguished in this fashion 138 // (also is the node in the tree), it is the last chunk to be found 139 // on the free list for a node in the tree and is only removed if 140 // it is the last chunk on the free list. 141 142 template <class Chunk_t, class FreeList_t> 143 class TreeChunk : public Chunk_t { 144 friend class TreeList<Chunk_t, FreeList_t>; 145 TreeList<Chunk_t, FreeList_t>* _list; 146 TreeList<Chunk_t, FreeList_t> _embedded_list; // if non-null, this chunk is on _list 147 148 static size_t _min_tree_chunk_size; 149 150 protected: 151 TreeList<Chunk_t, FreeList_t>* embedded_list() const { return (TreeList<Chunk_t, FreeList_t>*) &_embedded_list; } 152 void set_embedded_list(TreeList<Chunk_t, FreeList_t>* v) { _embedded_list = *v; } 153 public: 154 TreeList<Chunk_t, FreeList_t>* list() { return _list; } 155 void set_list(TreeList<Chunk_t, FreeList_t>* v) { _list = v; } 156 static TreeChunk<Chunk_t, FreeList_t>* as_TreeChunk(Chunk_t* fc); 157 // Initialize fields in a TreeChunk that should be 158 // initialized when the TreeChunk is being added to 159 // a free list in the tree. 160 void initialize() { embedded_list()->initialize(); } 161 162 Chunk_t* next() const { return Chunk_t::next(); } 163 Chunk_t* prev() const { return Chunk_t::prev(); } 164 size_t size() const volatile { return Chunk_t::size(); } 165 166 static size_t min_size() { 167 return _min_tree_chunk_size; 168 } 169 170 // debugging 171 void verify_tree_chunk_list() const; 172 void assert_is_mangled() const; 173 }; 174 175 176 template <class Chunk_t, class FreeList_t> 177 class BinaryTreeDictionary: public FreeBlockDictionary<Chunk_t> { 178 friend class VMStructs; 179 size_t _total_size; 180 size_t _total_free_blocks; 181 TreeList<Chunk_t, FreeList_t>* _root; 182 183 // private accessors 184 void set_total_size(size_t v) { _total_size = v; } 185 virtual void inc_total_size(size_t v); 186 virtual void dec_total_size(size_t v); 187 void set_total_free_blocks(size_t v) { _total_free_blocks = v; } 188 TreeList<Chunk_t, FreeList_t>* root() const { return _root; } 189 void set_root(TreeList<Chunk_t, FreeList_t>* v) { _root = v; } 190 191 // This field is added and can be set to point to the 192 // the Mutex used to synchronize access to the 193 // dictionary so that assertion checking can be done. 194 // For example it is set to point to _parDictionaryAllocLock. 195 NOT_PRODUCT(Mutex* _lock;) 196 197 // Remove a chunk of size "size" or larger from the tree and 198 // return it. If the chunk 199 // is the last chunk of that size, remove the node for that size 200 // from the tree. 201 TreeChunk<Chunk_t, FreeList_t>* get_chunk_from_tree(size_t size, enum FreeBlockDictionary<Chunk_t>::Dither dither); 202 // Remove this chunk from the tree. If the removal results 203 // in an empty list in the tree, remove the empty list. 204 TreeChunk<Chunk_t, FreeList_t>* remove_chunk_from_tree(TreeChunk<Chunk_t, FreeList_t>* tc); 205 // Remove the node in the trees starting at tl that has the 206 // minimum value and return it. Repair the tree as needed. 207 TreeList<Chunk_t, FreeList_t>* remove_tree_minimum(TreeList<Chunk_t, FreeList_t>* tl); 208 // Add this free chunk to the tree. 209 void insert_chunk_in_tree(Chunk_t* freeChunk); 210 public: 211 212 // Return a list of the specified size or NULL from the tree. 213 // The list is not removed from the tree. 214 TreeList<Chunk_t, FreeList_t>* find_list (size_t size) const; 215 216 void verify_tree() const; 217 // verify that the given chunk is in the tree. 218 bool verify_chunk_in_free_list(Chunk_t* tc) const; 219 private: 220 void verify_tree_helper(TreeList<Chunk_t, FreeList_t>* tl) const; 221 static size_t verify_prev_free_ptrs(TreeList<Chunk_t, FreeList_t>* tl); 222 223 // Returns the total number of chunks in the list. 224 size_t total_list_length(TreeList<Chunk_t, FreeList_t>* tl) const; 225 // Returns the total number of words in the chunks in the tree 226 // starting at "tl". 227 size_t total_size_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const; 228 // Returns the sum of the square of the size of each block 229 // in the tree starting at "tl". 230 double sum_of_squared_block_sizes(TreeList<Chunk_t, FreeList_t>* const tl) const; 231 // Returns the total number of free blocks in the tree starting 232 // at "tl". 233 size_t total_free_blocks_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const; 234 size_t num_free_blocks() const; 235 size_t tree_height() const; 236 size_t tree_height_helper(TreeList<Chunk_t, FreeList_t>* tl) const; 237 size_t total_nodes_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const; 238 size_t total_nodes_helper(TreeList<Chunk_t, FreeList_t>* tl) const; 239 240 public: 241 // Constructor 242 BinaryTreeDictionary() : 243 _total_size(0), _total_free_blocks(0), _root(0) {} 244 245 BinaryTreeDictionary(MemRegion mr); 246 247 // Public accessors 248 size_t total_size() const { return _total_size; } 249 size_t total_free_blocks() const { return _total_free_blocks; } 250 251 // Reset the dictionary to the initial conditions with 252 // a single free chunk. 253 void reset(MemRegion mr); 254 void reset(HeapWord* addr, size_t size); 255 // Reset the dictionary to be empty. 256 void reset(); 257 258 // Return a chunk of size "size" or greater from 259 // the tree. 260 Chunk_t* get_chunk(size_t size, enum FreeBlockDictionary<Chunk_t>::Dither dither) { 261 FreeBlockDictionary<Chunk_t>::verify_par_locked(); 262 Chunk_t* res = get_chunk_from_tree(size, dither); 263 assert(res == NULL || res->is_free(), 264 "Should be returning a free chunk"); 265 assert(dither != FreeBlockDictionary<Chunk_t>::exactly || 266 res == NULL || res->size() == size, "Not correct size"); 267 return res; 268 } 269 270 void return_chunk(Chunk_t* chunk) { 271 FreeBlockDictionary<Chunk_t>::verify_par_locked(); 272 insert_chunk_in_tree(chunk); 273 } 274 275 void remove_chunk(Chunk_t* chunk) { 276 FreeBlockDictionary<Chunk_t>::verify_par_locked(); 277 remove_chunk_from_tree((TreeChunk<Chunk_t, FreeList_t>*)chunk); 278 assert(chunk->is_free(), "Should still be a free chunk"); 279 } 280 281 size_t max_chunk_size() const; 282 size_t total_chunk_size(debug_only(const Mutex* lock)) const { 283 debug_only( 284 if (lock != NULL && lock->owned_by_self()) { 285 assert(total_size_in_tree(root()) == total_size(), 286 "_total_size inconsistency"); 287 } 288 ) 289 return total_size(); 290 } 291 292 size_t min_size() const { 293 return TreeChunk<Chunk_t, FreeList_t>::min_size(); 294 } 295 296 double sum_of_squared_block_sizes() const { 297 return sum_of_squared_block_sizes(root()); 298 } 299 300 Chunk_t* find_chunk_ends_at(HeapWord* target) const; 301 302 // Find the list with size "size" in the binary tree and update 303 // the statistics in the list according to "split" (chunk was 304 // split or coalesce) and "birth" (chunk was added or removed). 305 void dict_census_update(size_t size, bool split, bool birth); 306 // Return true if the dictionary is overpopulated (more chunks of 307 // this size than desired) for size "size". 308 bool coal_dict_over_populated(size_t size); 309 // Methods called at the beginning of a sweep to prepare the 310 // statistics for the sweep. 311 void begin_sweep_dict_census(double coalSurplusPercent, 312 float inter_sweep_current, 313 float inter_sweep_estimate, 314 float intra_sweep_estimate); 315 // Methods called after the end of a sweep to modify the 316 // statistics for the sweep. 317 void end_sweep_dict_census(double splitSurplusPercent); 318 // Return the largest free chunk in the tree. 319 Chunk_t* find_largest_dict() const; 320 // Accessors for statistics 321 void set_tree_surplus(double splitSurplusPercent); 322 void set_tree_hints(void); 323 // Reset statistics for all the lists in the tree. 324 void clear_tree_census(void); 325 // Print the statistics for all the lists in the tree. Also may 326 // print out summaries. 327 void print_dict_census(void) const; 328 void print_free_lists(outputStream* st) const; 329 330 // For debugging. Returns the sum of the _returned_bytes for 331 // all lists in the tree. 332 size_t sum_dict_returned_bytes() PRODUCT_RETURN0; 333 // Sets the _returned_bytes for all the lists in the tree to zero. 334 void initialize_dict_returned_bytes() PRODUCT_RETURN; 335 // For debugging. Return the total number of chunks in the dictionary. 336 size_t total_count() PRODUCT_RETURN0; 337 338 void report_statistics() const; 339 340 void verify() const; 341 }; 342 343 #endif // SHARE_VM_MEMORY_BINARYTREEDICTIONARY_HPP