1 /*
2 * Copyright (c) 2001, 2017, 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.
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23 */
24
25 #ifndef SHARE_VM_MEMORY_BINARYTREEDICTIONARY_INLINE_HPP
26 #define SHARE_VM_MEMORY_BINARYTREEDICTIONARY_INLINE_HPP
27
28 #include "gc/shared/spaceDecorator.hpp"
29 #include "logging/log.hpp"
30 #include "logging/logStream.hpp"
31 #include "memory/binaryTreeDictionary.hpp"
32 #include "memory/freeList.inline.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "runtime/mutex.hpp"
35 #include "runtime/globals.hpp"
36 #include "utilities/macros.hpp"
37 #include "utilities/ostream.hpp"
38
39 ////////////////////////////////////////////////////////////////////////////////
40 // A binary tree based search structure for free blocks.
41 // This is currently used in the Concurrent Mark&Sweep implementation.
42 ////////////////////////////////////////////////////////////////////////////////
43
44 template <class Chunk_t, class FreeList_t>
45 TreeChunk<Chunk_t, FreeList_t>* TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(Chunk_t* fc) {
46 // Do some assertion checking here.
47 return (TreeChunk<Chunk_t, FreeList_t>*) fc;
48 }
49
50 template <class Chunk_t, class FreeList_t>
51 void TreeChunk<Chunk_t, FreeList_t>::verify_tree_chunk_list() const {
52 TreeChunk<Chunk_t, FreeList_t>* nextTC = (TreeChunk<Chunk_t, FreeList_t>*)next();
53 if (prev() != NULL) { // interior list node shouldn't have tree fields
54 guarantee(embedded_list()->parent() == NULL && embedded_list()->left() == NULL &&
55 embedded_list()->right() == NULL, "should be clear");
56 }
57 if (nextTC != NULL) {
58 guarantee(as_TreeChunk(nextTC->prev()) == this, "broken chain");
59 guarantee(nextTC->size() == size(), "wrong size");
60 nextTC->verify_tree_chunk_list();
61 }
62 }
63
64 template <class Chunk_t, class FreeList_t>
65 TreeList<Chunk_t, FreeList_t>::TreeList() : _parent(NULL),
66 _left(NULL), _right(NULL) {}
67
68 template <class Chunk_t, class FreeList_t>
69 TreeList<Chunk_t, FreeList_t>*
70 TreeList<Chunk_t, FreeList_t>::as_TreeList(TreeChunk<Chunk_t,FreeList_t>* tc) {
71 // This first free chunk in the list will be the tree list.
72 assert((tc->size() >= (TreeChunk<Chunk_t, FreeList_t>::min_size())),
73 "Chunk is too small for a TreeChunk");
74 TreeList<Chunk_t, FreeList_t>* tl = tc->embedded_list();
75 tl->initialize();
76 tc->set_list(tl);
77 tl->set_size(tc->size());
78 tl->link_head(tc);
79 tl->link_tail(tc);
80 tl->set_count(1);
81 assert(tl->parent() == NULL, "Should be clear");
82 return tl;
83 }
84
85 template <class Chunk_t, class FreeList_t>
86 TreeList<Chunk_t, FreeList_t>*
87 TreeList<Chunk_t, FreeList_t>::as_TreeList(HeapWord* addr, size_t size) {
88 TreeChunk<Chunk_t, FreeList_t>* tc = (TreeChunk<Chunk_t, FreeList_t>*) addr;
89 assert((size >= TreeChunk<Chunk_t, FreeList_t>::min_size()),
90 "Chunk is too small for a TreeChunk");
91 // The space will have been mangled initially but
92 // is not remangled when a Chunk_t is returned to the free list
93 // (since it is used to maintain the chunk on the free list).
94 tc->assert_is_mangled();
95 tc->set_size(size);
96 tc->link_prev(NULL);
97 tc->link_next(NULL);
98 TreeList<Chunk_t, FreeList_t>* tl = TreeList<Chunk_t, FreeList_t>::as_TreeList(tc);
99 return tl;
100 }
101
102
103 template <class Chunk_t, class FreeList_t>
104 TreeList<Chunk_t, FreeList_t>*
105 TreeList<Chunk_t, FreeList_t>::get_better_list(
106 BinaryTreeDictionary<Chunk_t, FreeList_t>* dictionary) {
107 return this;
108 }
109
110 template <class Chunk_t, class FreeList_t>
111 TreeList<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::remove_chunk_replace_if_needed(TreeChunk<Chunk_t, FreeList_t>* tc) {
112
113 TreeList<Chunk_t, FreeList_t>* retTL = this;
114 Chunk_t* list = head();
115 assert(!list || list != list->next(), "Chunk on list twice");
116 assert(tc != NULL, "Chunk being removed is NULL");
117 assert(parent() == NULL || this == parent()->left() ||
118 this == parent()->right(), "list is inconsistent");
119 assert(tc->is_free(), "Header is not marked correctly");
120 assert(head() == NULL || head()->prev() == NULL, "list invariant");
121 assert(tail() == NULL || tail()->next() == NULL, "list invariant");
122
123 Chunk_t* prevFC = tc->prev();
124 TreeChunk<Chunk_t, FreeList_t>* nextTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(tc->next());
125 assert(list != NULL, "should have at least the target chunk");
126
127 // Is this the first item on the list?
128 if (tc == list) {
129 // The "getChunk..." functions for a TreeList<Chunk_t, FreeList_t> will not return the
130 // first chunk in the list unless it is the last chunk in the list
131 // because the first chunk is also acting as the tree node.
132 // When coalescing happens, however, the first chunk in the a tree
133 // list can be the start of a free range. Free ranges are removed
134 // from the free lists so that they are not available to be
135 // allocated when the sweeper yields (giving up the free list lock)
136 // to allow mutator activity. If this chunk is the first in the
137 // list and is not the last in the list, do the work to copy the
138 // TreeList<Chunk_t, FreeList_t> from the first chunk to the next chunk and update all
139 // the TreeList<Chunk_t, FreeList_t> pointers in the chunks in the list.
140 if (nextTC == NULL) {
141 assert(prevFC == NULL, "Not last chunk in the list");
142 set_tail(NULL);
143 set_head(NULL);
144 } else {
145 // copy embedded list.
146 nextTC->set_embedded_list(tc->embedded_list());
147 retTL = nextTC->embedded_list();
148 // Fix the pointer to the list in each chunk in the list.
149 // This can be slow for a long list. Consider having
150 // an option that does not allow the first chunk on the
151 // list to be coalesced.
152 for (TreeChunk<Chunk_t, FreeList_t>* curTC = nextTC; curTC != NULL;
153 curTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(curTC->next())) {
154 curTC->set_list(retTL);
155 }
156 // Fix the parent to point to the new TreeList<Chunk_t, FreeList_t>.
157 if (retTL->parent() != NULL) {
158 if (this == retTL->parent()->left()) {
159 retTL->parent()->set_left(retTL);
160 } else {
161 assert(this == retTL->parent()->right(), "Parent is incorrect");
162 retTL->parent()->set_right(retTL);
163 }
164 }
165 // Fix the children's parent pointers to point to the
166 // new list.
167 assert(right() == retTL->right(), "Should have been copied");
168 if (retTL->right() != NULL) {
169 retTL->right()->set_parent(retTL);
170 }
171 assert(left() == retTL->left(), "Should have been copied");
172 if (retTL->left() != NULL) {
173 retTL->left()->set_parent(retTL);
174 }
175 retTL->link_head(nextTC);
176 assert(nextTC->is_free(), "Should be a free chunk");
177 }
178 } else {
179 if (nextTC == NULL) {
180 // Removing chunk at tail of list
181 this->link_tail(prevFC);
182 }
183 // Chunk is interior to the list
184 prevFC->link_after(nextTC);
185 }
186
187 // Below this point the embedded TreeList<Chunk_t, FreeList_t> being used for the
188 // tree node may have changed. Don't use "this"
189 // TreeList<Chunk_t, FreeList_t>*.
190 // chunk should still be a free chunk (bit set in _prev)
191 assert(!retTL->head() || retTL->size() == retTL->head()->size(),
192 "Wrong sized chunk in list");
193 debug_only(
194 tc->link_prev(NULL);
195 tc->link_next(NULL);
196 tc->set_list(NULL);
197 bool prev_found = false;
198 bool next_found = false;
199 for (Chunk_t* curFC = retTL->head();
200 curFC != NULL; curFC = curFC->next()) {
201 assert(curFC != tc, "Chunk is still in list");
202 if (curFC == prevFC) {
203 prev_found = true;
204 }
205 if (curFC == nextTC) {
206 next_found = true;
207 }
208 }
209 assert(prevFC == NULL || prev_found, "Chunk was lost from list");
210 assert(nextTC == NULL || next_found, "Chunk was lost from list");
211 assert(retTL->parent() == NULL ||
212 retTL == retTL->parent()->left() ||
213 retTL == retTL->parent()->right(),
214 "list is inconsistent");
215 )
216 retTL->decrement_count();
217
218 assert(tc->is_free(), "Should still be a free chunk");
219 assert(retTL->head() == NULL || retTL->head()->prev() == NULL,
220 "list invariant");
221 assert(retTL->tail() == NULL || retTL->tail()->next() == NULL,
222 "list invariant");
223 return retTL;
224 }
225
226 template <class Chunk_t, class FreeList_t>
227 void TreeList<Chunk_t, FreeList_t>::return_chunk_at_tail(TreeChunk<Chunk_t, FreeList_t>* chunk) {
228 assert(chunk != NULL, "returning NULL chunk");
229 assert(chunk->list() == this, "list should be set for chunk");
230 assert(tail() != NULL, "The tree list is embedded in the first chunk");
231 // which means that the list can never be empty.
232 assert(!this->verify_chunk_in_free_list(chunk), "Double entry");
233 assert(head() == NULL || head()->prev() == NULL, "list invariant");
234 assert(tail() == NULL || tail()->next() == NULL, "list invariant");
235
236 Chunk_t* fc = tail();
237 fc->link_after(chunk);
238 this->link_tail(chunk);
239
240 assert(!tail() || size() == tail()->size(), "Wrong sized chunk in list");
241 FreeList_t::increment_count();
242 debug_only(this->increment_returned_bytes_by(chunk->size()*sizeof(HeapWord));)
243 assert(head() == NULL || head()->prev() == NULL, "list invariant");
244 assert(tail() == NULL || tail()->next() == NULL, "list invariant");
245 }
246
247 // Add this chunk at the head of the list. "At the head of the list"
248 // is defined to be after the chunk pointer to by head(). This is
249 // because the TreeList<Chunk_t, FreeList_t> is embedded in the first TreeChunk<Chunk_t, FreeList_t> in the
250 // list. See the definition of TreeChunk<Chunk_t, FreeList_t>.
251 template <class Chunk_t, class FreeList_t>
252 void TreeList<Chunk_t, FreeList_t>::return_chunk_at_head(TreeChunk<Chunk_t, FreeList_t>* chunk) {
253 assert(chunk->list() == this, "list should be set for chunk");
254 assert(head() != NULL, "The tree list is embedded in the first chunk");
255 assert(chunk != NULL, "returning NULL chunk");
256 assert(!this->verify_chunk_in_free_list(chunk), "Double entry");
257 assert(head() == NULL || head()->prev() == NULL, "list invariant");
258 assert(tail() == NULL || tail()->next() == NULL, "list invariant");
259
260 Chunk_t* fc = head()->next();
261 if (fc != NULL) {
262 chunk->link_after(fc);
263 } else {
264 assert(tail() == NULL, "List is inconsistent");
265 this->link_tail(chunk);
266 }
267 head()->link_after(chunk);
268 assert(!head() || size() == head()->size(), "Wrong sized chunk in list");
269 FreeList_t::increment_count();
270 debug_only(this->increment_returned_bytes_by(chunk->size()*sizeof(HeapWord));)
271 assert(head() == NULL || head()->prev() == NULL, "list invariant");
272 assert(tail() == NULL || tail()->next() == NULL, "list invariant");
273 }
274
275 template <class Chunk_t, class FreeList_t>
276 void TreeChunk<Chunk_t, FreeList_t>::assert_is_mangled() const {
277 assert((ZapUnusedHeapArea &&
278 SpaceMangler::is_mangled((HeapWord*) Chunk_t::size_addr()) &&
279 SpaceMangler::is_mangled((HeapWord*) Chunk_t::prev_addr()) &&
280 SpaceMangler::is_mangled((HeapWord*) Chunk_t::next_addr())) ||
281 (size() == 0 && prev() == NULL && next() == NULL),
282 "Space should be clear or mangled");
283 }
284
285 template <class Chunk_t, class FreeList_t>
286 TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::head_as_TreeChunk() {
287 assert(head() == NULL || (TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(head())->list() == this),
288 "Wrong type of chunk?");
289 return TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(head());
290 }
291
292 template <class Chunk_t, class FreeList_t>
293 TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::first_available() {
294 assert(head() != NULL, "The head of the list cannot be NULL");
295 Chunk_t* fc = head()->next();
296 TreeChunk<Chunk_t, FreeList_t>* retTC;
297 if (fc == NULL) {
298 retTC = head_as_TreeChunk();
299 } else {
300 retTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(fc);
301 }
302 assert(retTC->list() == this, "Wrong type of chunk.");
303 return retTC;
304 }
305
306 // Returns the block with the largest heap address amongst
307 // those in the list for this size; potentially slow and expensive,
308 // use with caution!
309 template <class Chunk_t, class FreeList_t>
310 TreeChunk<Chunk_t, FreeList_t>* TreeList<Chunk_t, FreeList_t>::largest_address() {
311 assert(head() != NULL, "The head of the list cannot be NULL");
312 Chunk_t* fc = head()->next();
313 TreeChunk<Chunk_t, FreeList_t>* retTC;
314 if (fc == NULL) {
315 retTC = head_as_TreeChunk();
316 } else {
317 // walk down the list and return the one with the highest
318 // heap address among chunks of this size.
319 Chunk_t* last = fc;
320 while (fc->next() != NULL) {
321 if ((HeapWord*)last < (HeapWord*)fc) {
322 last = fc;
323 }
324 fc = fc->next();
325 }
326 retTC = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(last);
327 }
328 assert(retTC->list() == this, "Wrong type of chunk.");
329 return retTC;
330 }
331
332 template <class Chunk_t, class FreeList_t>
333 BinaryTreeDictionary<Chunk_t, FreeList_t>::BinaryTreeDictionary(MemRegion mr) {
334 assert((mr.byte_size() > min_size()), "minimum chunk size");
335
336 reset(mr);
337 assert(root()->left() == NULL, "reset check failed");
338 assert(root()->right() == NULL, "reset check failed");
339 assert(root()->head()->next() == NULL, "reset check failed");
340 assert(root()->head()->prev() == NULL, "reset check failed");
341 assert(total_size() == root()->size(), "reset check failed");
342 assert(total_free_blocks() == 1, "reset check failed");
343 }
344
345 template <class Chunk_t, class FreeList_t>
346 void BinaryTreeDictionary<Chunk_t, FreeList_t>::inc_total_size(size_t inc) {
347 _total_size = _total_size + inc;
348 }
349
350 template <class Chunk_t, class FreeList_t>
351 void BinaryTreeDictionary<Chunk_t, FreeList_t>::dec_total_size(size_t dec) {
352 _total_size = _total_size - dec;
353 }
354
355 template <class Chunk_t, class FreeList_t>
356 void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset(MemRegion mr) {
357 assert((mr.byte_size() > min_size()), "minimum chunk size");
358 set_root(TreeList<Chunk_t, FreeList_t>::as_TreeList(mr.start(), mr.word_size()));
359 set_total_size(mr.word_size());
360 set_total_free_blocks(1);
361 }
362
363 template <class Chunk_t, class FreeList_t>
364 void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset(HeapWord* addr, size_t byte_size) {
365 MemRegion mr(addr, heap_word_size(byte_size));
366 reset(mr);
367 }
368
369 template <class Chunk_t, class FreeList_t>
370 void BinaryTreeDictionary<Chunk_t, FreeList_t>::reset() {
371 set_root(NULL);
372 set_total_size(0);
373 set_total_free_blocks(0);
374 }
375
376 // Get a free block of size at least size from tree, or NULL.
377 template <class Chunk_t, class FreeList_t>
378 TreeChunk<Chunk_t, FreeList_t>*
379 BinaryTreeDictionary<Chunk_t, FreeList_t>::get_chunk_from_tree(size_t size)
380 {
381 TreeList<Chunk_t, FreeList_t> *curTL, *prevTL;
382 TreeChunk<Chunk_t, FreeList_t>* retTC = NULL;
383
384 assert((size >= min_size()), "minimum chunk size");
385 if (FLSVerifyDictionary) {
386 verify_tree();
387 }
388 // starting at the root, work downwards trying to find match.
389 // Remember the last node of size too great or too small.
390 for (prevTL = curTL = root(); curTL != NULL;) {
391 if (curTL->size() == size) { // exact match
392 break;
393 }
394 prevTL = curTL;
395 if (curTL->size() < size) { // proceed to right sub-tree
396 curTL = curTL->right();
397 } else { // proceed to left sub-tree
398 assert(curTL->size() > size, "size inconsistency");
399 curTL = curTL->left();
400 }
401 }
402 if (curTL == NULL) { // couldn't find exact match
403
404 // try and find the next larger size by walking back up the search path
405 for (curTL = prevTL; curTL != NULL;) {
406 if (curTL->size() >= size) break;
407 else curTL = curTL->parent();
408 }
409 assert(curTL == NULL || curTL->count() > 0,
410 "An empty list should not be in the tree");
411 }
412 if (curTL != NULL) {
413 assert(curTL->size() >= size, "size inconsistency");
414
415 curTL = curTL->get_better_list(this);
416
417 retTC = curTL->first_available();
418 assert((retTC != NULL) && (curTL->count() > 0),
419 "A list in the binary tree should not be NULL");
420 assert(retTC->size() >= size,
421 "A chunk of the wrong size was found");
422 remove_chunk_from_tree(retTC);
423 assert(retTC->is_free(), "Header is not marked correctly");
424 }
425
426 if (FLSVerifyDictionary) {
427 verify();
428 }
429 return retTC;
430 }
431
432 template <class Chunk_t, class FreeList_t>
433 TreeList<Chunk_t, FreeList_t>* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_list(size_t size) const {
434 TreeList<Chunk_t, FreeList_t>* curTL;
435 for (curTL = root(); curTL != NULL;) {
436 if (curTL->size() == size) { // exact match
437 break;
438 }
439
440 if (curTL->size() < size) { // proceed to right sub-tree
441 curTL = curTL->right();
442 } else { // proceed to left sub-tree
443 assert(curTL->size() > size, "size inconsistency");
444 curTL = curTL->left();
445 }
446 }
447 return curTL;
448 }
449
450
451 template <class Chunk_t, class FreeList_t>
452 bool BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_chunk_in_free_list(Chunk_t* tc) const {
453 size_t size = tc->size();
454 TreeList<Chunk_t, FreeList_t>* tl = find_list(size);
455 if (tl == NULL) {
456 return false;
457 } else {
458 return tl->verify_chunk_in_free_list(tc);
459 }
460 }
461
462 template <class Chunk_t, class FreeList_t>
463 Chunk_t* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_largest_dict() const {
464 TreeList<Chunk_t, FreeList_t> *curTL = root();
465 if (curTL != NULL) {
466 while(curTL->right() != NULL) curTL = curTL->right();
467 return curTL->largest_address();
468 } else {
469 return NULL;
470 }
471 }
472
473 // Remove the current chunk from the tree. If it is not the last
474 // chunk in a list on a tree node, just unlink it.
475 // If it is the last chunk in the list (the next link is NULL),
476 // remove the node and repair the tree.
477 template <class Chunk_t, class FreeList_t>
478 TreeChunk<Chunk_t, FreeList_t>*
479 BinaryTreeDictionary<Chunk_t, FreeList_t>::remove_chunk_from_tree(TreeChunk<Chunk_t, FreeList_t>* tc) {
480 assert(tc != NULL, "Should not call with a NULL chunk");
481 assert(tc->is_free(), "Header is not marked correctly");
482
483 TreeList<Chunk_t, FreeList_t> *newTL, *parentTL;
484 TreeChunk<Chunk_t, FreeList_t>* retTC;
485 TreeList<Chunk_t, FreeList_t>* tl = tc->list();
486 debug_only(
487 bool removing_only_chunk = false;
488 if (tl == _root) {
489 if ((_root->left() == NULL) && (_root->right() == NULL)) {
490 if (_root->count() == 1) {
491 assert(_root->head() == tc, "Should only be this one chunk");
492 removing_only_chunk = true;
493 }
494 }
495 }
496 )
497 assert(tl != NULL, "List should be set");
498 assert(tl->parent() == NULL || tl == tl->parent()->left() ||
499 tl == tl->parent()->right(), "list is inconsistent");
500
501 bool complicated_splice = false;
502
503 retTC = tc;
504 // Removing this chunk can have the side effect of changing the node
505 // (TreeList<Chunk_t, FreeList_t>*) in the tree. If the node is the root, update it.
506 TreeList<Chunk_t, FreeList_t>* replacementTL = tl->remove_chunk_replace_if_needed(tc);
507 assert(tc->is_free(), "Chunk should still be free");
508 assert(replacementTL->parent() == NULL ||
509 replacementTL == replacementTL->parent()->left() ||
510 replacementTL == replacementTL->parent()->right(),
511 "list is inconsistent");
512 if (tl == root()) {
513 assert(replacementTL->parent() == NULL, "Incorrectly replacing root");
514 set_root(replacementTL);
515 }
516 #ifdef ASSERT
517 if (tl != replacementTL) {
518 assert(replacementTL->head() != NULL,
519 "If the tree list was replaced, it should not be a NULL list");
520 TreeList<Chunk_t, FreeList_t>* rhl = replacementTL->head_as_TreeChunk()->list();
521 TreeList<Chunk_t, FreeList_t>* rtl =
522 TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(replacementTL->tail())->list();
523 assert(rhl == replacementTL, "Broken head");
524 assert(rtl == replacementTL, "Broken tail");
525 assert(replacementTL->size() == tc->size(), "Broken size");
526 }
527 #endif
528
529 // Does the tree need to be repaired?
530 if (replacementTL->count() == 0) {
531 assert(replacementTL->head() == NULL &&
532 replacementTL->tail() == NULL, "list count is incorrect");
533 // Find the replacement node for the (soon to be empty) node being removed.
534 // if we have a single (or no) child, splice child in our stead
535 if (replacementTL->left() == NULL) {
536 // left is NULL so pick right. right may also be NULL.
537 newTL = replacementTL->right();
538 debug_only(replacementTL->clear_right();)
539 } else if (replacementTL->right() == NULL) {
540 // right is NULL
541 newTL = replacementTL->left();
542 debug_only(replacementTL->clear_left();)
543 } else { // we have both children, so, by patriarchal convention,
544 // my replacement is least node in right sub-tree
545 complicated_splice = true;
546 newTL = remove_tree_minimum(replacementTL->right());
547 assert(newTL != NULL && newTL->left() == NULL &&
548 newTL->right() == NULL, "sub-tree minimum exists");
549 }
550 // newTL is the replacement for the (soon to be empty) node.
551 // newTL may be NULL.
552 // should verify; we just cleanly excised our replacement
553 if (FLSVerifyDictionary) {
554 verify_tree();
555 }
556 // first make newTL my parent's child
557 if ((parentTL = replacementTL->parent()) == NULL) {
558 // newTL should be root
559 assert(tl == root(), "Incorrectly replacing root");
560 set_root(newTL);
561 if (newTL != NULL) {
562 newTL->clear_parent();
563 }
564 } else if (parentTL->right() == replacementTL) {
565 // replacementTL is a right child
566 parentTL->set_right(newTL);
567 } else { // replacementTL is a left child
568 assert(parentTL->left() == replacementTL, "should be left child");
569 parentTL->set_left(newTL);
570 }
571 debug_only(replacementTL->clear_parent();)
572 if (complicated_splice) { // we need newTL to get replacementTL's
573 // two children
574 assert(newTL != NULL &&
575 newTL->left() == NULL && newTL->right() == NULL,
576 "newTL should not have encumbrances from the past");
577 // we'd like to assert as below:
578 // assert(replacementTL->left() != NULL && replacementTL->right() != NULL,
579 // "else !complicated_splice");
580 // ... however, the above assertion is too strong because we aren't
581 // guaranteed that replacementTL->right() is still NULL.
582 // Recall that we removed
583 // the right sub-tree minimum from replacementTL.
584 // That may well have been its right
585 // child! So we'll just assert half of the above:
586 assert(replacementTL->left() != NULL, "else !complicated_splice");
587 newTL->set_left(replacementTL->left());
588 newTL->set_right(replacementTL->right());
589 debug_only(
590 replacementTL->clear_right();
591 replacementTL->clear_left();
592 )
593 }
594 assert(replacementTL->right() == NULL &&
595 replacementTL->left() == NULL &&
596 replacementTL->parent() == NULL,
597 "delete without encumbrances");
598 }
599
600 assert(total_size() >= retTC->size(), "Incorrect total size");
601 dec_total_size(retTC->size()); // size book-keeping
602 assert(total_free_blocks() > 0, "Incorrect total count");
603 set_total_free_blocks(total_free_blocks() - 1);
604
605 assert(retTC != NULL, "null chunk?");
606 assert(retTC->prev() == NULL && retTC->next() == NULL,
607 "should return without encumbrances");
608 if (FLSVerifyDictionary) {
609 verify_tree();
610 }
611 assert(!removing_only_chunk || _root == NULL, "root should be NULL");
612 return TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(retTC);
613 }
614
615 // Remove the leftmost node (lm) in the tree and return it.
616 // If lm has a right child, link it to the left node of
617 // the parent of lm.
618 template <class Chunk_t, class FreeList_t>
619 TreeList<Chunk_t, FreeList_t>* BinaryTreeDictionary<Chunk_t, FreeList_t>::remove_tree_minimum(TreeList<Chunk_t, FreeList_t>* tl) {
620 assert(tl != NULL && tl->parent() != NULL, "really need a proper sub-tree");
621 // locate the subtree minimum by walking down left branches
622 TreeList<Chunk_t, FreeList_t>* curTL = tl;
623 for (; curTL->left() != NULL; curTL = curTL->left());
624 // obviously curTL now has at most one child, a right child
625 if (curTL != root()) { // Should this test just be removed?
626 TreeList<Chunk_t, FreeList_t>* parentTL = curTL->parent();
627 if (parentTL->left() == curTL) { // curTL is a left child
628 parentTL->set_left(curTL->right());
629 } else {
630 // If the list tl has no left child, then curTL may be
631 // the right child of parentTL.
632 assert(parentTL->right() == curTL, "should be a right child");
633 parentTL->set_right(curTL->right());
634 }
635 } else {
636 // The only use of this method would not pass the root of the
637 // tree (as indicated by the assertion above that the tree list
638 // has a parent) but the specification does not explicitly exclude the
639 // passing of the root so accommodate it.
640 set_root(NULL);
641 }
642 debug_only(
643 curTL->clear_parent(); // Test if this needs to be cleared
644 curTL->clear_right(); // recall, above, left child is already null
645 )
646 // we just excised a (non-root) node, we should still verify all tree invariants
647 if (FLSVerifyDictionary) {
648 verify_tree();
649 }
650 return curTL;
651 }
652
653 template <class Chunk_t, class FreeList_t>
654 void BinaryTreeDictionary<Chunk_t, FreeList_t>::insert_chunk_in_tree(Chunk_t* fc) {
655 TreeList<Chunk_t, FreeList_t> *curTL, *prevTL;
656 size_t size = fc->size();
657
658 assert((size >= min_size()),
659 SIZE_FORMAT " is too small to be a TreeChunk<Chunk_t, FreeList_t> " SIZE_FORMAT,
660 size, min_size());
661 if (FLSVerifyDictionary) {
662 verify_tree();
663 }
664
665 fc->clear_next();
666 fc->link_prev(NULL);
667
668 // work down from the _root, looking for insertion point
669 for (prevTL = curTL = root(); curTL != NULL;) {
670 if (curTL->size() == size) // exact match
671 break;
672 prevTL = curTL;
673 if (curTL->size() > size) { // follow left branch
674 curTL = curTL->left();
675 } else { // follow right branch
676 assert(curTL->size() < size, "size inconsistency");
677 curTL = curTL->right();
678 }
679 }
680 TreeChunk<Chunk_t, FreeList_t>* tc = TreeChunk<Chunk_t, FreeList_t>::as_TreeChunk(fc);
681 // This chunk is being returned to the binary tree. Its embedded
682 // TreeList<Chunk_t, FreeList_t> should be unused at this point.
683 tc->initialize();
684 if (curTL != NULL) { // exact match
685 tc->set_list(curTL);
686 curTL->return_chunk_at_tail(tc);
687 } else { // need a new node in tree
688 tc->clear_next();
689 tc->link_prev(NULL);
690 TreeList<Chunk_t, FreeList_t>* newTL = TreeList<Chunk_t, FreeList_t>::as_TreeList(tc);
691 assert(((TreeChunk<Chunk_t, FreeList_t>*)tc)->list() == newTL,
692 "List was not initialized correctly");
693 if (prevTL == NULL) { // we are the only tree node
694 assert(root() == NULL, "control point invariant");
695 set_root(newTL);
696 } else { // insert under prevTL ...
697 if (prevTL->size() < size) { // am right child
698 assert(prevTL->right() == NULL, "control point invariant");
699 prevTL->set_right(newTL);
700 } else { // am left child
701 assert(prevTL->size() > size && prevTL->left() == NULL, "cpt pt inv");
702 prevTL->set_left(newTL);
703 }
704 }
705 }
706 assert(tc->list() != NULL, "Tree list should be set");
707
708 inc_total_size(size);
709 // Method 'total_size_in_tree' walks through the every block in the
710 // tree, so it can cause significant performance loss if there are
711 // many blocks in the tree
712 assert(!FLSVerifyDictionary || total_size_in_tree(root()) == total_size(), "_total_size inconsistency");
713 set_total_free_blocks(total_free_blocks() + 1);
714 if (FLSVerifyDictionary) {
715 verify_tree();
716 }
717 }
718
719 template <class Chunk_t, class FreeList_t>
720 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::max_chunk_size() const {
721 verify_par_locked();
722 TreeList<Chunk_t, FreeList_t>* tc = root();
723 if (tc == NULL) return 0;
724 for (; tc->right() != NULL; tc = tc->right());
725 return tc->size();
726 }
727
728 template <class Chunk_t, class FreeList_t>
729 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_list_length(TreeList<Chunk_t, FreeList_t>* tl) const {
730 size_t res;
731 res = tl->count();
732 #ifdef ASSERT
733 size_t cnt;
734 Chunk_t* tc = tl->head();
735 for (cnt = 0; tc != NULL; tc = tc->next(), cnt++);
736 assert(res == cnt, "The count is not being maintained correctly");
737 #endif
738 return res;
739 }
740
741 template <class Chunk_t, class FreeList_t>
742 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_size_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
743 if (tl == NULL)
744 return 0;
745 return (tl->size() * total_list_length(tl)) +
746 total_size_in_tree(tl->left()) +
747 total_size_in_tree(tl->right());
748 }
749
750 template <class Chunk_t, class FreeList_t>
751 double BinaryTreeDictionary<Chunk_t, FreeList_t>::sum_of_squared_block_sizes(TreeList<Chunk_t, FreeList_t>* const tl) const {
752 if (tl == NULL) {
753 return 0.0;
754 }
755 double size = (double)(tl->size());
756 double curr = size * size * total_list_length(tl);
757 curr += sum_of_squared_block_sizes(tl->left());
758 curr += sum_of_squared_block_sizes(tl->right());
759 return curr;
760 }
761
762 template <class Chunk_t, class FreeList_t>
763 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_free_blocks_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
764 if (tl == NULL)
765 return 0;
766 return total_list_length(tl) +
767 total_free_blocks_in_tree(tl->left()) +
768 total_free_blocks_in_tree(tl->right());
769 }
770
771 template <class Chunk_t, class FreeList_t>
772 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::num_free_blocks() const {
773 assert(total_free_blocks_in_tree(root()) == total_free_blocks(),
774 "_total_free_blocks inconsistency");
775 return total_free_blocks();
776 }
777
778 template <class Chunk_t, class FreeList_t>
779 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::tree_height_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
780 if (tl == NULL)
781 return 0;
782 return 1 + MAX2(tree_height_helper(tl->left()),
783 tree_height_helper(tl->right()));
784 }
785
786 template <class Chunk_t, class FreeList_t>
787 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::tree_height() const {
788 return tree_height_helper(root());
789 }
790
791 template <class Chunk_t, class FreeList_t>
792 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_nodes_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
793 if (tl == NULL) {
794 return 0;
795 }
796 return 1 + total_nodes_helper(tl->left()) +
797 total_nodes_helper(tl->right());
798 }
799
800 template <class Chunk_t, class FreeList_t>
801 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_nodes_in_tree(TreeList<Chunk_t, FreeList_t>* tl) const {
802 return total_nodes_helper(root());
803 }
804
805 // Searches the tree for a chunk that ends at the
806 // specified address.
807 template <class Chunk_t, class FreeList_t>
808 class EndTreeSearchClosure : public DescendTreeSearchClosure<Chunk_t, FreeList_t> {
809 HeapWord* _target;
810 Chunk_t* _found;
811
812 public:
813 EndTreeSearchClosure(HeapWord* target) : _target(target), _found(NULL) {}
814 bool do_list(FreeList_t* fl) {
815 Chunk_t* item = fl->head();
816 while (item != NULL) {
817 if (item->end() == (uintptr_t*) _target) {
818 _found = item;
819 return true;
820 }
821 item = item->next();
822 }
823 return false;
824 }
825 Chunk_t* found() { return _found; }
826 };
827
828 template <class Chunk_t, class FreeList_t>
829 Chunk_t* BinaryTreeDictionary<Chunk_t, FreeList_t>::find_chunk_ends_at(HeapWord* target) const {
830 EndTreeSearchClosure<Chunk_t, FreeList_t> etsc(target);
831 bool found_target = etsc.do_tree(root());
832 assert(found_target || etsc.found() == NULL, "Consistency check");
833 assert(!found_target || etsc.found() != NULL, "Consistency check");
834 return etsc.found();
835 }
836
837 // Closures and methods for calculating total bytes returned to the
838 // free lists in the tree.
839 #ifndef PRODUCT
840 template <class Chunk_t, class FreeList_t>
841 class InitializeDictReturnedBytesClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
842 public:
843 void do_list(FreeList_t* fl) {
844 fl->set_returned_bytes(0);
845 }
846 };
847
848 template <class Chunk_t, class FreeList_t>
849 void BinaryTreeDictionary<Chunk_t, FreeList_t>::initialize_dict_returned_bytes() {
850 InitializeDictReturnedBytesClosure<Chunk_t, FreeList_t> idrb;
851 idrb.do_tree(root());
852 }
853
854 template <class Chunk_t, class FreeList_t>
855 class ReturnedBytesClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
856 size_t _dict_returned_bytes;
857 public:
858 ReturnedBytesClosure() { _dict_returned_bytes = 0; }
859 void do_list(FreeList_t* fl) {
860 _dict_returned_bytes += fl->returned_bytes();
861 }
862 size_t dict_returned_bytes() { return _dict_returned_bytes; }
863 };
864
865 template <class Chunk_t, class FreeList_t>
866 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::sum_dict_returned_bytes() {
867 ReturnedBytesClosure<Chunk_t, FreeList_t> rbc;
868 rbc.do_tree(root());
869
870 return rbc.dict_returned_bytes();
871 }
872
873 // Count the number of entries in the tree.
874 template <class Chunk_t, class FreeList_t>
875 class treeCountClosure : public DescendTreeCensusClosure<Chunk_t, FreeList_t> {
876 public:
877 uint count;
878 treeCountClosure(uint c) { count = c; }
879 void do_list(FreeList_t* fl) {
880 count++;
881 }
882 };
883
884 template <class Chunk_t, class FreeList_t>
885 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_count() {
886 treeCountClosure<Chunk_t, FreeList_t> ctc(0);
887 ctc.do_tree(root());
888 return ctc.count;
889 }
890
891 template <class Chunk_t, class FreeList_t>
892 Mutex* BinaryTreeDictionary<Chunk_t, FreeList_t>::par_lock() const {
893 return _lock;
894 }
895
896 template <class Chunk_t, class FreeList_t>
897 void BinaryTreeDictionary<Chunk_t, FreeList_t>::set_par_lock(Mutex* lock) {
898 _lock = lock;
899 }
900
901 template <class Chunk_t, class FreeList_t>
902 void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_par_locked() const {
903 #ifdef ASSERT
904 Thread* my_thread = Thread::current();
905 if (my_thread->is_GC_task_thread()) {
906 assert(par_lock() != NULL, "Should be using locking?");
907 assert_lock_strong(par_lock());
908 }
909 #endif // ASSERT
910 }
911 #endif // PRODUCT
912
913 // Print summary statistics
914 template <class Chunk_t, class FreeList_t>
915 void BinaryTreeDictionary<Chunk_t, FreeList_t>::report_statistics(outputStream* st) const {
916 verify_par_locked();
917 st->print_cr("Statistics for BinaryTreeDictionary:");
918 st->print_cr("------------------------------------");
919 size_t total_size = total_chunk_size(debug_only(NULL));
920 size_t free_blocks = num_free_blocks();
921 st->print_cr("Total Free Space: " SIZE_FORMAT, total_size);
922 st->print_cr("Max Chunk Size: " SIZE_FORMAT, max_chunk_size());
923 st->print_cr("Number of Blocks: " SIZE_FORMAT, free_blocks);
924 if (free_blocks > 0) {
925 st->print_cr("Av. Block Size: " SIZE_FORMAT, total_size/free_blocks);
926 }
927 st->print_cr("Tree Height: " SIZE_FORMAT, tree_height());
928 }
929
930 template <class Chunk_t, class FreeList_t>
931 class PrintFreeListsClosure : public AscendTreeCensusClosure<Chunk_t, FreeList_t> {
932 outputStream* _st;
933 int _print_line;
934
935 public:
936 PrintFreeListsClosure(outputStream* st) {
937 _st = st;
938 _print_line = 0;
939 }
940 void do_list(FreeList_t* fl) {
941 if (++_print_line >= 40) {
942 FreeList_t::print_labels_on(_st, "size");
943 _print_line = 0;
944 }
945 fl->print_on(_st);
946 size_t sz = fl->size();
947 for (Chunk_t* fc = fl->head(); fc != NULL;
948 fc = fc->next()) {
949 _st->print_cr("\t[" PTR_FORMAT "," PTR_FORMAT ") %s",
950 p2i(fc), p2i((HeapWord*)fc + sz),
951 fc->cantCoalesce() ? "\t CC" : "");
952 }
953 }
954 };
955
956 template <class Chunk_t, class FreeList_t>
957 void BinaryTreeDictionary<Chunk_t, FreeList_t>::print_free_lists(outputStream* st) const {
958
959 FreeList_t::print_labels_on(st, "size");
960 PrintFreeListsClosure<Chunk_t, FreeList_t> pflc(st);
961 pflc.do_tree(root());
962 }
963
964 // Verify the following tree invariants:
965 // . _root has no parent
966 // . parent and child point to each other
967 // . each node's key correctly related to that of its child(ren)
968 template <class Chunk_t, class FreeList_t>
969 void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_tree() const {
970 guarantee(root() == NULL || total_free_blocks() == 0 ||
971 total_size() != 0, "_total_size shouldn't be 0?");
972 guarantee(root() == NULL || root()->parent() == NULL, "_root shouldn't have parent");
973 verify_tree_helper(root());
974 }
975
976 template <class Chunk_t, class FreeList_t>
977 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_prev_free_ptrs(TreeList<Chunk_t, FreeList_t>* tl) {
978 size_t ct = 0;
979 for (Chunk_t* curFC = tl->head(); curFC != NULL; curFC = curFC->next()) {
980 ct++;
981 assert(curFC->prev() == NULL || curFC->prev()->is_free(),
982 "Chunk should be free");
983 }
984 return ct;
985 }
986
987 // Note: this helper is recursive rather than iterative, so use with
988 // caution on very deep trees; and watch out for stack overflow errors;
989 // In general, to be used only for debugging.
990 template <class Chunk_t, class FreeList_t>
991 void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify_tree_helper(TreeList<Chunk_t, FreeList_t>* tl) const {
992 if (tl == NULL)
993 return;
994 guarantee(tl->size() != 0, "A list must has a size");
995 guarantee(tl->left() == NULL || tl->left()->parent() == tl,
996 "parent<-/->left");
997 guarantee(tl->right() == NULL || tl->right()->parent() == tl,
998 "parent<-/->right");;
999 guarantee(tl->left() == NULL || tl->left()->size() < tl->size(),
1000 "parent !> left");
1001 guarantee(tl->right() == NULL || tl->right()->size() > tl->size(),
1002 "parent !< left");
1003 guarantee(tl->head() == NULL || tl->head()->is_free(), "!Free");
1004 guarantee(tl->head() == NULL || tl->head_as_TreeChunk()->list() == tl,
1005 "list inconsistency");
1006 guarantee(tl->count() > 0 || (tl->head() == NULL && tl->tail() == NULL),
1007 "list count is inconsistent");
1008 guarantee(tl->count() > 1 || tl->head() == tl->tail(),
1009 "list is incorrectly constructed");
1010 size_t count = verify_prev_free_ptrs(tl);
1011 guarantee(count == (size_t)tl->count(), "Node count is incorrect");
1012 if (tl->head() != NULL) {
1013 tl->head_as_TreeChunk()->verify_tree_chunk_list();
1014 }
1015 verify_tree_helper(tl->left());
1016 verify_tree_helper(tl->right());
1017 }
1018
1019 template <class Chunk_t, class FreeList_t>
1020 void BinaryTreeDictionary<Chunk_t, FreeList_t>::verify() const {
1021 verify_tree();
1022 guarantee(total_size() == total_size_in_tree(root()), "Total Size inconsistency");
1023 }
1024
1025 template <class Chunk_t, class FreeList_t>
1026 size_t BinaryTreeDictionary<Chunk_t, FreeList_t>::total_chunk_size(debug_only(const Mutex* lock)) const {
1027 debug_only(
1028 if (lock != NULL && lock->owned_by_self()) {
1029 assert(total_size_in_tree(root()) == total_size(),
1030 "_total_size inconsistency");
1031 }
1032 )
1033 return total_size();
1034 }
1035
1036 #endif // SHARE_VM_MEMORY_BINARYTREEDICTIONARY_INLINE_HPP