Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/g1/sparsePRT.hpp @ 652:4aaa9f5e02a8
4766230: Hotspot vtable inconsistencies cause core dumps. 6579515. 6582242.
Reviewed-by: kamg, coleenp
author | acorn |
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date | Wed, 18 Mar 2009 17:20:57 -0400 |
parents | 7bb995fbd3c0 |
children | d44bdab1c03d |
rev | line source |
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342 | 1 /* |
579 | 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved. |
342 | 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 // Sparse remembered set for a heap region (the "owning" region). Maps | |
26 // indices of other regions to short sequences of cards in the other region | |
27 // that might contain pointers into the owner region. | |
28 | |
29 // These tables only expand while they are accessed in parallel -- | |
30 // deletions may be done in single-threaded code. This allows us to allow | |
31 // unsynchronized reads/iterations, as long as expansions caused by | |
32 // insertions only enqueue old versions for deletions, but do not delete | |
33 // old versions synchronously. | |
34 | |
35 | |
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36 class SparsePRTEntry: public CHeapObj { |
342 | 37 public: |
38 enum SomePublicConstants { | |
39 CardsPerEntry = (short)4, | |
40 NullEntry = (short)-1, | |
41 DeletedEntry = (short)-2 | |
42 }; | |
43 | |
44 private: | |
45 short _region_ind; | |
46 short _next_index; | |
47 short _cards[CardsPerEntry]; | |
48 | |
49 public: | |
50 | |
51 // Set the region_ind to the given value, and delete all cards. | |
52 inline void init(short region_ind); | |
53 | |
54 short r_ind() const { return _region_ind; } | |
55 bool valid_entry() const { return r_ind() >= 0; } | |
56 void set_r_ind(short rind) { _region_ind = rind; } | |
57 | |
58 short next_index() const { return _next_index; } | |
59 short* next_index_addr() { return &_next_index; } | |
60 void set_next_index(short ni) { _next_index = ni; } | |
61 | |
62 // Returns "true" iff the entry contains the given card index. | |
63 inline bool contains_card(short card_index) const; | |
64 | |
65 // Returns the number of non-NULL card entries. | |
66 inline int num_valid_cards() const; | |
67 | |
68 // Requires that the entry not contain the given card index. If there is | |
69 // space available, add the given card index to the entry and return | |
70 // "true"; otherwise, return "false" to indicate that the entry is full. | |
71 enum AddCardResult { | |
72 overflow, | |
73 found, | |
74 added | |
75 }; | |
76 inline AddCardResult add_card(short card_index); | |
77 | |
78 // Copy the current entry's cards into "cards". | |
79 inline void copy_cards(short* cards) const; | |
80 // Copy the current entry's cards into the "_card" array of "e." | |
81 inline void copy_cards(SparsePRTEntry* e) const; | |
82 | |
83 inline short card(int i) const { return _cards[i]; } | |
84 }; | |
85 | |
86 | |
87 class RSHashTable : public CHeapObj { | |
88 | |
89 friend class RSHashTableIter; | |
90 | |
91 enum SomePrivateConstants { | |
92 NullEntry = -1 | |
93 }; | |
94 | |
95 size_t _capacity; | |
96 size_t _capacity_mask; | |
97 size_t _occupied_entries; | |
98 size_t _occupied_cards; | |
99 | |
100 SparsePRTEntry* _entries; | |
101 short* _buckets; | |
102 short _free_region; | |
103 short _free_list; | |
104 | |
105 static RSHashTable* _head_deleted_list; | |
106 RSHashTable* _next_deleted; | |
107 RSHashTable* next_deleted() { return _next_deleted; } | |
108 void set_next_deleted(RSHashTable* rsht) { _next_deleted = rsht; } | |
109 bool _deleted; | |
110 void set_deleted(bool b) { _deleted = b; } | |
111 | |
112 // Requires that the caller hold a lock preventing parallel modifying | |
113 // operations, and that the the table be less than completely full. If | |
114 // an entry for "region_ind" is already in the table, finds it and | |
115 // returns its address; otherwise returns "NULL." | |
116 SparsePRTEntry* entry_for_region_ind(short region_ind) const; | |
117 | |
118 // Requires that the caller hold a lock preventing parallel modifying | |
119 // operations, and that the the table be less than completely full. If | |
120 // an entry for "region_ind" is already in the table, finds it and | |
121 // returns its address; otherwise allocates, initializes, inserts and | |
122 // returns a new entry for "region_ind". | |
123 SparsePRTEntry* entry_for_region_ind_create(short region_ind); | |
124 | |
125 // Returns the index of the next free entry in "_entries". | |
126 short alloc_entry(); | |
127 // Declares the entry "fi" to be free. (It must have already been | |
128 // deleted from any bucket lists. | |
129 void free_entry(short fi); | |
130 | |
131 public: | |
132 RSHashTable(size_t capacity); | |
133 ~RSHashTable(); | |
134 | |
135 // Attempts to ensure that the given card_index in the given region is in | |
136 // the sparse table. If successful (because the card was already | |
137 // present, or because it was successfullly added) returns "true". | |
138 // Otherwise, returns "false" to indicate that the addition would | |
139 // overflow the entry for the region. The caller must transfer these | |
140 // entries to a larger-capacity representation. | |
141 bool add_card(short region_id, short card_index); | |
142 | |
143 bool get_cards(short region_id, short* cards); | |
144 bool delete_entry(short region_id); | |
145 | |
146 bool contains_card(short region_id, short card_index) const; | |
147 | |
148 void add_entry(SparsePRTEntry* e); | |
149 | |
150 void clear(); | |
151 | |
152 size_t capacity() const { return _capacity; } | |
153 size_t capacity_mask() const { return _capacity_mask; } | |
154 size_t occupied_entries() const { return _occupied_entries; } | |
155 size_t occupied_cards() const { return _occupied_cards; } | |
156 size_t mem_size() const; | |
157 bool deleted() { return _deleted; } | |
158 | |
159 SparsePRTEntry* entry(int i) const { return &_entries[i]; } | |
160 | |
161 void print(); | |
162 | |
163 static void add_to_deleted_list(RSHashTable* rsht); | |
164 static RSHashTable* get_from_deleted_list(); | |
165 | |
166 | |
167 }; | |
168 | |
169 // ValueObj because will be embedded in HRRS iterator. | |
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apetrusenko
parents:
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170 class RSHashTableIter VALUE_OBJ_CLASS_SPEC { |
342 | 171 short _tbl_ind; |
172 short _bl_ind; | |
173 short _card_ind; | |
174 RSHashTable* _rsht; | |
175 size_t _heap_bot_card_ind; | |
176 | |
177 enum SomePrivateConstants { | |
178 CardsPerRegion = HeapRegion::GrainBytes >> CardTableModRefBS::card_shift | |
179 }; | |
180 | |
181 // If the bucket list pointed to by _bl_ind contains a card, sets | |
182 // _bl_ind to the index of that entry, and returns the card. | |
183 // Otherwise, returns SparseEntry::NullEnty. | |
184 short find_first_card_in_list(); | |
185 // Computes the proper card index for the card whose offset in the | |
186 // current region (as indicated by _bl_ind) is "ci". | |
187 // This is subject to errors when there is iteration concurrent with | |
188 // modification, but these errors should be benign. | |
189 size_t compute_card_ind(short ci); | |
190 | |
191 public: | |
192 RSHashTableIter(size_t heap_bot_card_ind) : | |
193 _tbl_ind(RSHashTable::NullEntry), | |
194 _bl_ind(RSHashTable::NullEntry), | |
195 _card_ind((SparsePRTEntry::CardsPerEntry-1)), | |
196 _rsht(NULL), | |
197 _heap_bot_card_ind(heap_bot_card_ind) | |
198 {} | |
199 | |
200 void init(RSHashTable* rsht) { | |
201 _rsht = rsht; | |
202 _tbl_ind = -1; // So that first increment gets to 0. | |
203 _bl_ind = RSHashTable::NullEntry; | |
204 _card_ind = (SparsePRTEntry::CardsPerEntry-1); | |
205 } | |
206 | |
207 bool has_next(size_t& card_index); | |
208 | |
209 }; | |
210 | |
211 // Concurrent accesss to a SparsePRT must be serialized by some external | |
212 // mutex. | |
213 | |
214 class SparsePRTIter; | |
215 | |
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216 class SparsePRT VALUE_OBJ_CLASS_SPEC { |
342 | 217 // Iterations are done on the _cur hash table, since they only need to |
218 // see entries visible at the start of a collection pause. | |
219 // All other operations are done using the _next hash table. | |
220 RSHashTable* _cur; | |
221 RSHashTable* _next; | |
222 | |
223 HeapRegion* _hr; | |
224 | |
225 enum SomeAdditionalPrivateConstants { | |
226 InitialCapacity = 16 | |
227 }; | |
228 | |
229 void expand(); | |
230 | |
231 bool _expanded; | |
232 | |
233 bool expanded() { return _expanded; } | |
234 void set_expanded(bool b) { _expanded = b; } | |
235 | |
236 SparsePRT* _next_expanded; | |
237 | |
238 SparsePRT* next_expanded() { return _next_expanded; } | |
239 void set_next_expanded(SparsePRT* nxt) { _next_expanded = nxt; } | |
240 | |
241 | |
242 static SparsePRT* _head_expanded_list; | |
243 | |
244 public: | |
245 SparsePRT(HeapRegion* hr); | |
246 | |
247 ~SparsePRT(); | |
248 | |
249 size_t occupied() const { return _next->occupied_cards(); } | |
250 size_t mem_size() const; | |
251 | |
252 // Attempts to ensure that the given card_index in the given region is in | |
253 // the sparse table. If successful (because the card was already | |
254 // present, or because it was successfullly added) returns "true". | |
255 // Otherwise, returns "false" to indicate that the addition would | |
256 // overflow the entry for the region. The caller must transfer these | |
257 // entries to a larger-capacity representation. | |
258 bool add_card(short region_id, short card_index); | |
259 | |
260 // If the table hold an entry for "region_ind", Copies its | |
261 // cards into "cards", which must be an array of length at least | |
262 // "CardsPerEntry", and returns "true"; otherwise, returns "false". | |
263 bool get_cards(short region_ind, short* cards); | |
264 | |
265 // If there is an entry for "region_ind", removes it and return "true"; | |
266 // otherwise returns "false." | |
267 bool delete_entry(short region_ind); | |
268 | |
269 // Clear the table, and reinitialize to initial capacity. | |
270 void clear(); | |
271 | |
272 // Ensure that "_cur" and "_next" point to the same table. | |
273 void cleanup(); | |
274 | |
275 // Clean up all tables on the expanded list. Called single threaded. | |
276 static void cleanup_all(); | |
617
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parents:
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277 RSHashTable* cur() const { return _cur; } |
342 | 278 |
279 | |
280 void init_iterator(SparsePRTIter* sprt_iter); | |
281 | |
282 static void add_to_expanded_list(SparsePRT* sprt); | |
283 static SparsePRT* get_from_expanded_list(); | |
284 | |
285 bool contains_card(short region_id, short card_index) const { | |
286 return _next->contains_card(region_id, card_index); | |
287 } | |
288 | |
289 #if 0 | |
290 void verify_is_cleared(); | |
291 void print(); | |
292 #endif | |
293 }; | |
294 | |
295 | |
296 class SparsePRTIter: public /* RSHashTable:: */RSHashTableIter { | |
297 public: | |
298 SparsePRTIter(size_t heap_bot_card_ind) : | |
299 /* RSHashTable:: */RSHashTableIter(heap_bot_card_ind) | |
300 {} | |
301 | |
302 void init(const SparsePRT* sprt) { | |
617
0db4adb6e914
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tonyp
parents:
549
diff
changeset
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303 RSHashTableIter::init(sprt->cur()); |
342 | 304 } |
305 bool has_next(size_t& card_index) { | |
306 return RSHashTableIter::has_next(card_index); | |
307 } | |
308 }; |