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 #include "precompiled.hpp"
26 #include "code/codeCache.hpp"
27 #include "code/nmethod.hpp"
28 #include "gc/g1/g1CodeCacheRemSet.hpp"
29 #include "gc/g1/heapRegion.hpp"
30 #include "memory/heap.hpp"
31 #include "memory/iterator.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "utilities/hashtable.inline.hpp"
34 #include "utilities/stack.inline.hpp"
35
36 class CodeRootSetTable : public Hashtable<nmethod*, mtGC> {
37 friend class G1CodeRootSetTest;
38 typedef HashtableEntry<nmethod*, mtGC> Entry;
39
40 static CodeRootSetTable* volatile _purge_list;
41
42 CodeRootSetTable* _purge_next;
43
44 unsigned int compute_hash(nmethod* nm) {
45 uintptr_t hash = (uintptr_t)nm;
46 return hash ^ (hash >> 7); // code heap blocks are 128byte aligned
47 }
48
49 void remove_entry(Entry* e, Entry* previous);
50 Entry* new_entry(nmethod* nm);
51
52 public:
53 CodeRootSetTable(int size) : Hashtable<nmethod*, mtGC>(size, sizeof(Entry)), _purge_next(NULL) {}
54 ~CodeRootSetTable();
55
56 // Needs to be protected locks
57 bool add(nmethod* nm);
58 bool remove(nmethod* nm);
59
60 // Can be called without locking
61 bool contains(nmethod* nm);
62
63 int entry_size() const { return BasicHashtable<mtGC>::entry_size(); }
64
65 void copy_to(CodeRootSetTable* new_table);
66 void nmethods_do(CodeBlobClosure* blk);
67
68 template<typename CB>
69 int remove_if(CB& should_remove);
70
71 static void purge_list_append(CodeRootSetTable* tbl);
72 static void purge();
73
74 static size_t static_mem_size() {
75 return sizeof(_purge_list);
76 }
77
78 size_t mem_size();
79 };
80
81 CodeRootSetTable* volatile CodeRootSetTable::_purge_list = NULL;
82
83 size_t CodeRootSetTable::mem_size() {
84 return sizeof(CodeRootSetTable) + (entry_size() * number_of_entries()) + (sizeof(HashtableBucket<mtGC>) * table_size());
85 }
86
87 CodeRootSetTable::Entry* CodeRootSetTable::new_entry(nmethod* nm) {
88 unsigned int hash = compute_hash(nm);
89 Entry* entry = (Entry*) new_entry_free_list();
90 if (entry == NULL) {
91 entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC);
92 }
93 entry->set_next(NULL);
94 entry->set_hash(hash);
95 entry->set_literal(nm);
96 return entry;
97 }
98
99 void CodeRootSetTable::remove_entry(Entry* e, Entry* previous) {
100 int index = hash_to_index(e->hash());
101 assert((e == bucket(index)) == (previous == NULL), "if e is the first entry then previous should be null");
102
103 if (previous == NULL) {
104 set_entry(index, e->next());
105 } else {
106 previous->set_next(e->next());
107 }
108 free_entry(e);
109 }
110
111 CodeRootSetTable::~CodeRootSetTable() {
112 for (int index = 0; index < table_size(); ++index) {
113 for (Entry* e = bucket(index); e != NULL; ) {
114 Entry* to_remove = e;
115 // read next before freeing.
116 e = e->next();
117 unlink_entry(to_remove);
118 FREE_C_HEAP_ARRAY(char, to_remove);
119 }
120 }
121 assert(number_of_entries() == 0, "should have removed all entries");
122 free_buckets();
123 for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) {
124 FREE_C_HEAP_ARRAY(char, e);
125 }
126 }
127
128 bool CodeRootSetTable::add(nmethod* nm) {
129 if (!contains(nm)) {
130 Entry* e = new_entry(nm);
131 int index = hash_to_index(e->hash());
132 add_entry(index, e);
133 return true;
134 }
135 return false;
136 }
137
138 bool CodeRootSetTable::contains(nmethod* nm) {
139 int index = hash_to_index(compute_hash(nm));
140 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
141 if (e->literal() == nm) {
142 return true;
143 }
144 }
145 return false;
146 }
147
148 bool CodeRootSetTable::remove(nmethod* nm) {
149 int index = hash_to_index(compute_hash(nm));
150 Entry* previous = NULL;
151 for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) {
152 if (e->literal() == nm) {
153 remove_entry(e, previous);
154 return true;
155 }
156 }
157 return false;
158 }
159
160 void CodeRootSetTable::copy_to(CodeRootSetTable* new_table) {
161 for (int index = 0; index < table_size(); ++index) {
162 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
163 new_table->add(e->literal());
164 }
165 }
166 new_table->copy_freelist(this);
167 }
168
169 void CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) {
170 for (int index = 0; index < table_size(); ++index) {
171 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
172 blk->do_code_blob(e->literal());
173 }
174 }
175 }
176
177 template<typename CB>
178 int CodeRootSetTable::remove_if(CB& should_remove) {
179 int num_removed = 0;
180 for (int index = 0; index < table_size(); ++index) {
181 Entry* previous = NULL;
182 Entry* e = bucket(index);
183 while (e != NULL) {
184 Entry* next = e->next();
185 if (should_remove(e->literal())) {
186 remove_entry(e, previous);
187 ++num_removed;
188 } else {
189 previous = e;
190 }
191 e = next;
192 }
193 }
194 return num_removed;
195 }
196
197 G1CodeRootSet::~G1CodeRootSet() {
198 delete _table;
199 }
200
201 CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
202 return (CodeRootSetTable*) OrderAccess::load_ptr_acquire(&_table);
203 }
204
205 void G1CodeRootSet::allocate_small_table() {
206 CodeRootSetTable* temp = new CodeRootSetTable(SmallSize);
207
208 OrderAccess::release_store_ptr(&_table, temp);
209 }
210
211 void CodeRootSetTable::purge_list_append(CodeRootSetTable* table) {
212 for (;;) {
213 table->_purge_next = _purge_list;
214 CodeRootSetTable* old = (CodeRootSetTable*) Atomic::cmpxchg_ptr(table, &_purge_list, table->_purge_next);
215 if (old == table->_purge_next) {
216 break;
217 }
218 }
219 }
220
221 void CodeRootSetTable::purge() {
222 CodeRootSetTable* table = _purge_list;
223 _purge_list = NULL;
224 while (table != NULL) {
225 CodeRootSetTable* to_purge = table;
226 table = table->_purge_next;
227 delete to_purge;
228 }
229 }
230
231 void G1CodeRootSet::move_to_large() {
232 CodeRootSetTable* temp = new CodeRootSetTable(LargeSize);
233
234 _table->copy_to(temp);
235
236 CodeRootSetTable::purge_list_append(_table);
237
238 OrderAccess::release_store_ptr(&_table, temp);
239 }
240
241 void G1CodeRootSet::purge() {
242 CodeRootSetTable::purge();
243 }
244
245 size_t G1CodeRootSet::static_mem_size() {
246 return CodeRootSetTable::static_mem_size();
247 }
248
249 void G1CodeRootSet::add(nmethod* method) {
250 bool added = false;
251 if (is_empty()) {
252 allocate_small_table();
253 }
254 added = _table->add(method);
255 if (added) {
256 if (_length == Threshold) {
257 move_to_large();
258 }
259 ++_length;
260 }
261 assert(_length == (size_t)_table->number_of_entries(), "sizes should match");
262 }
263
264 bool G1CodeRootSet::remove(nmethod* method) {
265 bool removed = false;
266 if (_table != NULL) {
267 removed = _table->remove(method);
268 }
269 if (removed) {
270 _length--;
271 if (_length == 0) {
272 clear();
273 }
274 }
275 assert((_length == 0 && _table == NULL) ||
276 (_length == (size_t)_table->number_of_entries()), "sizes should match");
277 return removed;
278 }
279
280 bool G1CodeRootSet::contains(nmethod* method) {
281 CodeRootSetTable* table = load_acquire_table(); // contains() may be called outside of lock, so ensure mem sync.
282 if (table != NULL) {
283 return table->contains(method);
284 }
285 return false;
286 }
287
288 void G1CodeRootSet::clear() {
289 delete _table;
290 _table = NULL;
291 _length = 0;
292 }
293
294 size_t G1CodeRootSet::mem_size() {
295 return sizeof(*this) + (_table != NULL ? _table->mem_size() : 0);
296 }
297
298 void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
299 if (_table != NULL) {
300 _table->nmethods_do(blk);
301 }
331 CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {}
332
333 bool operator() (nmethod* nm) {
334 _detector._points_into = false;
335 _blobs.do_code_blob(nm);
336 return !_detector._points_into;
337 }
338 };
339
340 void G1CodeRootSet::clean(HeapRegion* owner) {
341 CleanCallback should_clean(owner);
342 if (_table != NULL) {
343 int removed = _table->remove_if(should_clean);
344 assert((size_t)removed <= _length, "impossible");
345 _length -= removed;
346 }
347 if (_length == 0) {
348 clear();
349 }
350 }
351
352 #ifndef PRODUCT
353
354 class G1CodeRootSetTest {
355 public:
356 static void test() {
357 {
358 G1CodeRootSet set1;
359 assert(set1.is_empty(), "Code root set must be initially empty but is not.");
360
361 assert(G1CodeRootSet::static_mem_size() == sizeof(void*),
362 "The code root set's static memory usage is incorrect, " SIZE_FORMAT " bytes", G1CodeRootSet::static_mem_size());
363
364 set1.add((nmethod*)1);
365 assert(set1.length() == 1, "Added exactly one element, but set contains "
366 SIZE_FORMAT " elements", set1.length());
367
368 const size_t num_to_add = (size_t)G1CodeRootSet::Threshold + 1;
369
370 for (size_t i = 1; i <= num_to_add; i++) {
371 set1.add((nmethod*)1);
372 }
373 assert(set1.length() == 1,
374 "Duplicate detection should not have increased the set size but "
375 "is " SIZE_FORMAT, set1.length());
376
377 for (size_t i = 2; i <= num_to_add; i++) {
378 set1.add((nmethod*)(uintptr_t)(i));
379 }
380 assert(set1.length() == num_to_add,
381 "After adding in total " SIZE_FORMAT " distinct code roots, they "
382 "need to be in the set, but there are only " SIZE_FORMAT,
383 num_to_add, set1.length());
384
385 assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable");
386
387 size_t num_popped = 0;
388 for (size_t i = 1; i <= num_to_add; i++) {
389 bool removed = set1.remove((nmethod*)i);
390 if (removed) {
391 num_popped += 1;
392 } else {
393 break;
394 }
395 }
396 assert(num_popped == num_to_add,
397 "Managed to pop " SIZE_FORMAT " code roots, but only " SIZE_FORMAT " "
398 "were added", num_popped, num_to_add);
399 assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable");
400
401 G1CodeRootSet::purge();
402
403 assert(CodeRootSetTable::_purge_list == NULL, "should have purged old small tables");
404
405 }
406
407 }
408 };
409
410 void TestCodeCacheRemSet_test() {
411 G1CodeRootSetTest::test();
412 }
413
414 #endif
|
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 #include "precompiled.hpp"
26 #include "code/codeCache.hpp"
27 #include "code/nmethod.hpp"
28 #include "gc/g1/g1CodeRootSetTable.hpp"
29 #include "gc/g1/g1CodeCacheRemSet.hpp"
30 #include "gc/g1/heapRegion.hpp"
31 #include "memory/heap.hpp"
32 #include "memory/iterator.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "utilities/hashtable.inline.hpp"
35 #include "utilities/stack.inline.hpp"
36
37 G1CodeRootSetTable* volatile G1CodeRootSetTable::_purge_list = NULL;
38
39 size_t G1CodeRootSetTable::mem_size() {
40 return sizeof(G1CodeRootSetTable) + (entry_size() * number_of_entries()) + (sizeof(HashtableBucket<mtGC>) * table_size());
41 }
42
43 G1CodeRootSetTable::Entry* G1CodeRootSetTable::new_entry(nmethod* nm) {
44 unsigned int hash = compute_hash(nm);
45 Entry* entry = (Entry*) new_entry_free_list();
46 if (entry == NULL) {
47 entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC);
48 }
49 entry->set_next(NULL);
50 entry->set_hash(hash);
51 entry->set_literal(nm);
52 return entry;
53 }
54
55 void G1CodeRootSetTable::remove_entry(Entry* e, Entry* previous) {
56 int index = hash_to_index(e->hash());
57 assert((e == bucket(index)) == (previous == NULL), "if e is the first entry then previous should be null");
58
59 if (previous == NULL) {
60 set_entry(index, e->next());
61 } else {
62 previous->set_next(e->next());
63 }
64 free_entry(e);
65 }
66
67 G1CodeRootSetTable::~G1CodeRootSetTable() {
68 for (int index = 0; index < table_size(); ++index) {
69 for (Entry* e = bucket(index); e != NULL; ) {
70 Entry* to_remove = e;
71 // read next before freeing.
72 e = e->next();
73 unlink_entry(to_remove);
74 FREE_C_HEAP_ARRAY(char, to_remove);
75 }
76 }
77 assert(number_of_entries() == 0, "should have removed all entries");
78 free_buckets();
79 for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) {
80 FREE_C_HEAP_ARRAY(char, e);
81 }
82 }
83
84 bool G1CodeRootSetTable::add(nmethod* nm) {
85 if (!contains(nm)) {
86 Entry* e = new_entry(nm);
87 int index = hash_to_index(e->hash());
88 add_entry(index, e);
89 return true;
90 }
91 return false;
92 }
93
94 bool G1CodeRootSetTable::contains(nmethod* nm) {
95 int index = hash_to_index(compute_hash(nm));
96 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
97 if (e->literal() == nm) {
98 return true;
99 }
100 }
101 return false;
102 }
103
104 bool G1CodeRootSetTable::remove(nmethod* nm) {
105 int index = hash_to_index(compute_hash(nm));
106 Entry* previous = NULL;
107 for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) {
108 if (e->literal() == nm) {
109 remove_entry(e, previous);
110 return true;
111 }
112 }
113 return false;
114 }
115
116 void G1CodeRootSetTable::copy_to(G1CodeRootSetTable* new_table) {
117 for (int index = 0; index < table_size(); ++index) {
118 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
119 new_table->add(e->literal());
120 }
121 }
122 new_table->copy_freelist(this);
123 }
124
125 void G1CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) {
126 for (int index = 0; index < table_size(); ++index) {
127 for (Entry* e = bucket(index); e != NULL; e = e->next()) {
128 blk->do_code_blob(e->literal());
129 }
130 }
131 }
132
133 template<typename CB>
134 int G1CodeRootSetTable::remove_if(CB& should_remove) {
135 int num_removed = 0;
136 for (int index = 0; index < table_size(); ++index) {
137 Entry* previous = NULL;
138 Entry* e = bucket(index);
139 while (e != NULL) {
140 Entry* next = e->next();
141 if (should_remove(e->literal())) {
142 remove_entry(e, previous);
143 ++num_removed;
144 } else {
145 previous = e;
146 }
147 e = next;
148 }
149 }
150 return num_removed;
151 }
152
153 G1CodeRootSet::~G1CodeRootSet() {
154 delete _table;
155 }
156
157 G1CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
158 return (G1CodeRootSetTable*) OrderAccess::load_ptr_acquire(&_table);
159 }
160
161 void G1CodeRootSet::allocate_small_table() {
162 G1CodeRootSetTable* temp = new G1CodeRootSetTable(SmallSize);
163
164 OrderAccess::release_store_ptr(&_table, temp);
165 }
166
167 void G1CodeRootSetTable::purge_list_append(G1CodeRootSetTable* table) {
168 for (;;) {
169 table->_purge_next = _purge_list;
170 G1CodeRootSetTable* old = (G1CodeRootSetTable*) Atomic::cmpxchg_ptr(table, &_purge_list, table->_purge_next);
171 if (old == table->_purge_next) {
172 break;
173 }
174 }
175 }
176
177 void G1CodeRootSetTable::purge() {
178 G1CodeRootSetTable* table = _purge_list;
179 _purge_list = NULL;
180 while (table != NULL) {
181 G1CodeRootSetTable* to_purge = table;
182 table = table->_purge_next;
183 delete to_purge;
184 }
185 }
186
187 void G1CodeRootSet::move_to_large() {
188 G1CodeRootSetTable* temp = new G1CodeRootSetTable(LargeSize);
189
190 _table->copy_to(temp);
191
192 G1CodeRootSetTable::purge_list_append(_table);
193
194 OrderAccess::release_store_ptr(&_table, temp);
195 }
196
197 void G1CodeRootSet::purge() {
198 G1CodeRootSetTable::purge();
199 }
200
201 size_t G1CodeRootSet::static_mem_size() {
202 return G1CodeRootSetTable::static_mem_size();
203 }
204
205 void G1CodeRootSet::add(nmethod* method) {
206 bool added = false;
207 if (is_empty()) {
208 allocate_small_table();
209 }
210 added = _table->add(method);
211 if (added) {
212 if (_length == Threshold) {
213 move_to_large();
214 }
215 ++_length;
216 }
217 assert(_length == (size_t)_table->number_of_entries(), "sizes should match");
218 }
219
220 bool G1CodeRootSet::remove(nmethod* method) {
221 bool removed = false;
222 if (_table != NULL) {
223 removed = _table->remove(method);
224 }
225 if (removed) {
226 _length--;
227 if (_length == 0) {
228 clear();
229 }
230 }
231 assert((_length == 0 && _table == NULL) ||
232 (_length == (size_t)_table->number_of_entries()), "sizes should match");
233 return removed;
234 }
235
236 bool G1CodeRootSet::contains(nmethod* method) {
237 G1CodeRootSetTable* table = load_acquire_table(); // contains() may be called outside of lock, so ensure mem sync.
238 if (table != NULL) {
239 return table->contains(method);
240 }
241 return false;
242 }
243
244 void G1CodeRootSet::clear() {
245 delete _table;
246 _table = NULL;
247 _length = 0;
248 }
249
250 size_t G1CodeRootSet::mem_size() {
251 return sizeof(*this) + (_table != NULL ? _table->mem_size() : 0);
252 }
253
254 void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
255 if (_table != NULL) {
256 _table->nmethods_do(blk);
257 }
287 CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {}
288
289 bool operator() (nmethod* nm) {
290 _detector._points_into = false;
291 _blobs.do_code_blob(nm);
292 return !_detector._points_into;
293 }
294 };
295
296 void G1CodeRootSet::clean(HeapRegion* owner) {
297 CleanCallback should_clean(owner);
298 if (_table != NULL) {
299 int removed = _table->remove_if(should_clean);
300 assert((size_t)removed <= _length, "impossible");
301 _length -= removed;
302 }
303 if (_length == 0) {
304 clear();
305 }
306 }
|