1 /*
2 * Copyright (c) 2003, 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.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/sharedClassUtil.hpp"
28 #include "classfile/dictionary.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/systemDictionaryShared.hpp"
31 #include "memory/iterator.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/orderAccess.inline.hpp"
35 #include "utilities/hashtable.inline.hpp"
36
37 DictionaryEntry* Dictionary::_current_class_entry = NULL;
38 int Dictionary::_current_class_index = 0;
39
40 size_t Dictionary::entry_size() {
41 if (DumpSharedSpaces) {
42 return SystemDictionaryShared::dictionary_entry_size();
43 } else {
44 return sizeof(DictionaryEntry);
45 }
46 }
47
48 Dictionary::Dictionary(int table_size)
49 : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size()) {
50 _current_class_index = 0;
51 _current_class_entry = NULL;
52 _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
53 };
54
55
56 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
57 int number_of_entries)
58 : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
59 _current_class_index = 0;
60 _current_class_entry = NULL;
61 _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
62 };
63
64 ProtectionDomainCacheEntry* Dictionary::cache_get(Handle protection_domain) {
65 return _pd_cache_table->get(protection_domain);
66 }
67
68 DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
69 ClassLoaderData* loader_data) {
70 DictionaryEntry* entry = (DictionaryEntry*)Hashtable<Klass*, mtClass>::new_entry(hash, klass);
71 entry->set_loader_data(loader_data);
72 entry->set_pd_set(NULL);
73 assert(klass->is_instance_klass(), "Must be");
74 if (DumpSharedSpaces) {
75 SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
76 }
77 return entry;
78 }
79
80
81 void Dictionary::free_entry(DictionaryEntry* entry) {
82 // avoid recursion when deleting linked list
83 while (entry->pd_set() != NULL) {
84 ProtectionDomainEntry* to_delete = entry->pd_set();
85 entry->set_pd_set(to_delete->next());
86 delete to_delete;
87 }
88 Hashtable<Klass*, mtClass>::free_entry(entry);
89 }
90
91
92 bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
93 #ifdef ASSERT
94 if (protection_domain == klass()->protection_domain()) {
95 // Ensure this doesn't show up in the pd_set (invariant)
96 bool in_pd_set = false;
97 for (ProtectionDomainEntry* current = _pd_set;
98 current != NULL;
99 current = current->next()) {
100 if (current->protection_domain() == protection_domain) {
101 in_pd_set = true;
102 break;
103 }
104 }
105 if (in_pd_set) {
106 assert(false, "A klass's protection domain should not show up "
107 "in its sys. dict. PD set");
108 }
109 }
110 #endif /* ASSERT */
111
112 if (protection_domain == klass()->protection_domain()) {
113 // Succeeds trivially
114 return true;
115 }
116
117 for (ProtectionDomainEntry* current = _pd_set;
118 current != NULL;
119 current = current->next()) {
120 if (current->protection_domain() == protection_domain) return true;
121 }
122 return false;
123 }
124
125
126 void DictionaryEntry::add_protection_domain(Dictionary* dict, Handle protection_domain) {
127 assert_locked_or_safepoint(SystemDictionary_lock);
128 if (!contains_protection_domain(protection_domain())) {
129 ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
130 ProtectionDomainEntry* new_head =
131 new ProtectionDomainEntry(entry, _pd_set);
132 // Warning: Preserve store ordering. The SystemDictionary is read
133 // without locks. The new ProtectionDomainEntry must be
134 // complete before other threads can be allowed to see it
135 // via a store to _pd_set.
136 OrderAccess::release_store_ptr(&_pd_set, new_head);
137 }
138 if (log_is_enabled(Trace, protectiondomain)) {
139 ResourceMark rm;
140 outputStream* log = Log(protectiondomain)::trace_stream();
141 print_count(log);
142 }
143 }
144
145
146 void Dictionary::do_unloading() {
147 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
148
149 // Remove unloadable entries and classes from system dictionary
150 // The placeholder array has been handled in always_strong_oops_do.
151 DictionaryEntry* probe = NULL;
152 for (int index = 0; index < table_size(); index++) {
153 for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
154 probe = *p;
155 Klass* e = probe->klass();
156 ClassLoaderData* loader_data = probe->loader_data();
157
158 InstanceKlass* ik = InstanceKlass::cast(e);
159
160 // Non-unloadable classes were handled in always_strong_oops_do
161 if (!is_strongly_reachable(loader_data, e)) {
162 // Entry was not visited in phase1 (negated test from phase1)
163 assert(!loader_data->is_the_null_class_loader_data(), "unloading entry with null class loader");
164 ClassLoaderData* k_def_class_loader_data = ik->class_loader_data();
165
166 // Do we need to delete this system dictionary entry?
167 bool purge_entry = false;
168
169 // Do we need to delete this system dictionary entry?
170 if (loader_data->is_unloading()) {
171 // If the loader is not live this entry should always be
172 // removed (will never be looked up again).
173 purge_entry = true;
174 } else {
175 // The loader in this entry is alive. If the klass is dead,
176 // (determined by checking the defining class loader)
177 // the loader must be an initiating loader (rather than the
178 // defining loader). Remove this entry.
179 if (k_def_class_loader_data->is_unloading()) {
180 // If we get here, the class_loader_data must not be the defining
181 // loader, it must be an initiating one.
182 assert(k_def_class_loader_data != loader_data,
183 "cannot have live defining loader and unreachable klass");
184 // Loader is live, but class and its defining loader are dead.
185 // Remove the entry. The class is going away.
186 purge_entry = true;
187 }
188 }
189
190 if (purge_entry) {
191 *p = probe->next();
192 if (probe == _current_class_entry) {
193 _current_class_entry = NULL;
194 }
195 free_entry(probe);
196 continue;
197 }
198 }
199 p = probe->next_addr();
200 }
201 }
202 }
203
204 void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
205 // Skip the strong roots probe marking if the closures are the same.
206 if (strong == weak) {
207 oops_do(strong);
208 return;
209 }
210
211 for (int index = 0; index < table_size(); index++) {
212 for (DictionaryEntry *probe = bucket(index);
213 probe != NULL;
214 probe = probe->next()) {
215 Klass* e = probe->klass();
216 ClassLoaderData* loader_data = probe->loader_data();
217 if (is_strongly_reachable(loader_data, e)) {
218 probe->set_strongly_reachable();
219 }
220 }
221 }
222 _pd_cache_table->roots_oops_do(strong, weak);
223 }
224
225 void Dictionary::remove_classes_in_error_state() {
226 assert(DumpSharedSpaces, "supported only when dumping");
227 DictionaryEntry* probe = NULL;
228 for (int index = 0; index < table_size(); index++) {
229 for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
230 probe = *p;
231 InstanceKlass* ik = InstanceKlass::cast(probe->klass());
232 if (ik->is_in_error_state()) { // purge this entry
233 *p = probe->next();
234 if (probe == _current_class_entry) {
235 _current_class_entry = NULL;
236 }
237 free_entry(probe);
238 ResourceMark rm;
239 tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
240 continue;
241 }
242
243 p = probe->next_addr();
244 }
245 }
246 }
247
248 void Dictionary::always_strong_oops_do(OopClosure* blk) {
249 // Follow all system classes and temporary placeholders in dictionary; only
250 // protection domain oops contain references into the heap. In a first
251 // pass over the system dictionary determine which need to be treated as
252 // strongly reachable and mark them as such.
253 for (int index = 0; index < table_size(); index++) {
254 for (DictionaryEntry *probe = bucket(index);
255 probe != NULL;
256 probe = probe->next()) {
257 Klass* e = probe->klass();
258 ClassLoaderData* loader_data = probe->loader_data();
259 if (is_strongly_reachable(loader_data, e)) {
260 probe->set_strongly_reachable();
261 }
262 }
263 }
264 // Then iterate over the protection domain cache to apply the closure on the
265 // previously marked ones.
266 _pd_cache_table->always_strong_oops_do(blk);
267 }
268
269
270 void Dictionary::always_strong_classes_do(KlassClosure* closure) {
271 // Follow all system classes and temporary placeholders in dictionary
272 for (int index = 0; index < table_size(); index++) {
273 for (DictionaryEntry* probe = bucket(index);
274 probe != NULL;
275 probe = probe->next()) {
276 Klass* e = probe->klass();
277 ClassLoaderData* loader_data = probe->loader_data();
278 if (is_strongly_reachable(loader_data, e)) {
279 closure->do_klass(e);
280 }
281 }
282 }
283 }
284
285
286 // Just the classes from defining class loaders
287 void Dictionary::classes_do(void f(Klass*)) {
288 for (int index = 0; index < table_size(); index++) {
289 for (DictionaryEntry* probe = bucket(index);
290 probe != NULL;
291 probe = probe->next()) {
292 Klass* k = probe->klass();
293 if (probe->loader_data() == k->class_loader_data()) {
294 f(k);
295 }
296 }
297 }
298 }
299
300 // Added for initialize_itable_for_klass to handle exceptions
301 // Just the classes from defining class loaders
302 void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
303 for (int index = 0; index < table_size(); index++) {
304 for (DictionaryEntry* probe = bucket(index);
305 probe != NULL;
306 probe = probe->next()) {
307 Klass* k = probe->klass();
308 if (probe->loader_data() == k->class_loader_data()) {
309 f(k, CHECK);
310 }
311 }
312 }
313 }
314
315 // All classes, and their class loaders
316 // Don't iterate over placeholders
317 void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
318 for (int index = 0; index < table_size(); index++) {
319 for (DictionaryEntry* probe = bucket(index);
320 probe != NULL;
321 probe = probe->next()) {
322 Klass* k = probe->klass();
323 f(k, probe->loader_data());
324 }
325 }
326 }
327
328 void Dictionary::oops_do(OopClosure* f) {
329 // Only the protection domain oops contain references into the heap. Iterate
330 // over all of them.
331 _pd_cache_table->oops_do(f);
332 }
333
334 void Dictionary::unlink(BoolObjectClosure* is_alive) {
335 // Only the protection domain cache table may contain references to the heap
336 // that need to be unlinked.
337 _pd_cache_table->unlink(is_alive);
338 }
339
340 Klass* Dictionary::try_get_next_class() {
341 while (true) {
342 if (_current_class_entry != NULL) {
343 Klass* k = _current_class_entry->klass();
344 _current_class_entry = _current_class_entry->next();
345 return k;
346 }
347 _current_class_index = (_current_class_index + 1) % table_size();
348 _current_class_entry = bucket(_current_class_index);
349 }
350 // never reached
351 }
352
353 // Add a loaded class to the system dictionary.
354 // Readers of the SystemDictionary aren't always locked, so _buckets
355 // is volatile. The store of the next field in the constructor is
356 // also cast to volatile; we do this to ensure store order is maintained
357 // by the compilers.
358
359 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
360 KlassHandle obj) {
361 assert_locked_or_safepoint(SystemDictionary_lock);
362 assert(obj() != NULL, "adding NULL obj");
363 assert(obj()->name() == class_name, "sanity check on name");
364 assert(loader_data != NULL, "Must be non-NULL");
365
366 unsigned int hash = compute_hash(class_name, loader_data);
367 int index = hash_to_index(hash);
368 DictionaryEntry* entry = new_entry(hash, obj(), loader_data);
369 add_entry(index, entry);
370 }
371
372
373 // This routine does not lock the system dictionary.
374 //
375 // Since readers don't hold a lock, we must make sure that system
376 // dictionary entries are only removed at a safepoint (when only one
377 // thread is running), and are added to in a safe way (all links must
378 // be updated in an MT-safe manner).
379 //
380 // Callers should be aware that an entry could be added just after
381 // _buckets[index] is read here, so the caller will not see the new entry.
382 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
383 Symbol* class_name,
384 ClassLoaderData* loader_data) {
385 DEBUG_ONLY(_lookup_count++);
386 for (DictionaryEntry* entry = bucket(index);
387 entry != NULL;
388 entry = entry->next()) {
389 if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
390 DEBUG_ONLY(bucket_count_hit(index));
391 return entry;
392 }
393 DEBUG_ONLY(_lookup_length++);
394 }
395 return NULL;
396 }
397
398
399 Klass* Dictionary::find(int index, unsigned int hash, Symbol* name,
400 ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
401 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
402 if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
403 return entry->klass();
404 } else {
405 return NULL;
406 }
407 }
408
409
410 Klass* Dictionary::find_class(int index, unsigned int hash,
411 Symbol* name, ClassLoaderData* loader_data) {
412 assert_locked_or_safepoint(SystemDictionary_lock);
413 assert (index == index_for(name, loader_data), "incorrect index?");
414
415 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
416 return (entry != NULL) ? entry->klass() : (Klass*)NULL;
417 }
418
419
420 // Variant of find_class for shared classes. No locking required, as
421 // that table is static.
422
423 Klass* Dictionary::find_shared_class(int index, unsigned int hash,
424 Symbol* name) {
425 assert (index == index_for(name, NULL), "incorrect index?");
426
427 DictionaryEntry* entry = get_entry(index, hash, name, NULL);
428 return (entry != NULL) ? entry->klass() : (Klass*)NULL;
429 }
430
431
432 void Dictionary::add_protection_domain(int index, unsigned int hash,
433 instanceKlassHandle klass,
434 ClassLoaderData* loader_data, Handle protection_domain,
435 TRAPS) {
436 Symbol* klass_name = klass->name();
437 DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);
438
439 assert(entry != NULL,"entry must be present, we just created it");
440 assert(protection_domain() != NULL,
441 "real protection domain should be present");
442
443 entry->add_protection_domain(this, protection_domain);
444
445 assert(entry->contains_protection_domain(protection_domain()),
446 "now protection domain should be present");
447 }
448
449
450 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
451 Symbol* name,
452 ClassLoaderData* loader_data,
453 Handle protection_domain) {
454 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
455 return entry->is_valid_protection_domain(protection_domain);
456 }
457
458
459 void Dictionary::reorder_dictionary() {
460
461 // Copy all the dictionary entries into a single master list.
462
463 DictionaryEntry* master_list = NULL;
464 for (int i = 0; i < table_size(); ++i) {
465 DictionaryEntry* p = bucket(i);
466 while (p != NULL) {
467 DictionaryEntry* tmp;
468 tmp = p->next();
469 p->set_next(master_list);
470 master_list = p;
471 p = tmp;
472 }
473 set_entry(i, NULL);
474 }
475
476 // Add the dictionary entries back to the list in the correct buckets.
477 while (master_list != NULL) {
478 DictionaryEntry* p = master_list;
479 master_list = master_list->next();
480 p->set_next(NULL);
481 Symbol* class_name = p->klass()->name();
482 // Since the null class loader data isn't copied to the CDS archive,
483 // compute the hash with NULL for loader data.
484 unsigned int hash = compute_hash(class_name, NULL);
485 int index = hash_to_index(hash);
486 p->set_hash(hash);
487 p->set_loader_data(NULL); // loader_data isn't copied to CDS
488 p->set_next(bucket(index));
489 set_entry(index, p);
490 }
491 }
492
493
494 unsigned int ProtectionDomainCacheTable::compute_hash(Handle protection_domain) {
495 // Identity hash can safepoint, so keep protection domain in a Handle.
496 return (unsigned int)(protection_domain->identity_hash());
497 }
498
499 int ProtectionDomainCacheTable::index_for(Handle protection_domain) {
500 return hash_to_index(compute_hash(protection_domain));
501 }
502
503 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
504 : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
505 {
506 }
507
508 void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
509 assert(SafepointSynchronize::is_at_safepoint(), "must be");
510 for (int i = 0; i < table_size(); ++i) {
511 ProtectionDomainCacheEntry** p = bucket_addr(i);
512 ProtectionDomainCacheEntry* entry = bucket(i);
513 while (entry != NULL) {
514 if (is_alive->do_object_b(entry->literal())) {
515 p = entry->next_addr();
516 } else {
517 *p = entry->next();
518 free_entry(entry);
519 }
520 entry = *p;
521 }
522 }
523 }
524
525 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
526 for (int index = 0; index < table_size(); index++) {
527 for (ProtectionDomainCacheEntry* probe = bucket(index);
528 probe != NULL;
529 probe = probe->next()) {
530 probe->oops_do(f);
531 }
532 }
533 }
534
535 void ProtectionDomainCacheTable::roots_oops_do(OopClosure* strong, OopClosure* weak) {
536 for (int index = 0; index < table_size(); index++) {
537 for (ProtectionDomainCacheEntry* probe = bucket(index);
538 probe != NULL;
539 probe = probe->next()) {
540 if (probe->is_strongly_reachable()) {
541 probe->reset_strongly_reachable();
542 probe->oops_do(strong);
543 } else {
544 if (weak != NULL) {
545 probe->oops_do(weak);
546 }
547 }
548 }
549 }
550 }
551
552 uint ProtectionDomainCacheTable::bucket_size() {
553 return sizeof(ProtectionDomainCacheEntry);
554 }
555
556 #ifndef PRODUCT
557 void ProtectionDomainCacheTable::print() {
558 tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
559 table_size(), number_of_entries());
560 for (int index = 0; index < table_size(); index++) {
561 for (ProtectionDomainCacheEntry* probe = bucket(index);
562 probe != NULL;
563 probe = probe->next()) {
564 probe->print();
565 }
566 }
567 }
568
569 void ProtectionDomainCacheEntry::print() {
570 tty->print_cr("entry " PTR_FORMAT " value " PTR_FORMAT " strongly_reachable %d next " PTR_FORMAT,
571 p2i(this), p2i(literal()), _strongly_reachable, p2i(next()));
572 }
573 #endif
574
575 void ProtectionDomainCacheTable::verify() {
576 int element_count = 0;
577 for (int index = 0; index < table_size(); index++) {
578 for (ProtectionDomainCacheEntry* probe = bucket(index);
579 probe != NULL;
580 probe = probe->next()) {
581 probe->verify();
582 element_count++;
583 }
584 }
585 guarantee(number_of_entries() == element_count,
586 "Verify of protection domain cache table failed");
587 DEBUG_ONLY(verify_lookup_length((double)number_of_entries() / table_size(), "Domain Cache Table"));
588 }
589
590 void ProtectionDomainCacheEntry::verify() {
591 guarantee(literal()->is_oop(), "must be an oop");
592 }
593
594 void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
595 // the caller marked the protection domain cache entries that we need to apply
596 // the closure on. Only process them.
597 for (int index = 0; index < table_size(); index++) {
598 for (ProtectionDomainCacheEntry* probe = bucket(index);
599 probe != NULL;
600 probe = probe->next()) {
601 if (probe->is_strongly_reachable()) {
602 probe->reset_strongly_reachable();
603 probe->oops_do(f);
604 }
605 }
606 }
607 }
608
609 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(Handle protection_domain) {
610 unsigned int hash = compute_hash(protection_domain);
611 int index = hash_to_index(hash);
612
613 ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
614 if (entry == NULL) {
615 entry = add_entry(index, hash, protection_domain);
616 }
617 return entry;
618 }
619
620 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, Handle protection_domain) {
621 for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
622 if (e->protection_domain() == protection_domain()) {
623 return e;
624 }
625 }
626
627 return NULL;
628 }
629
630 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, Handle protection_domain) {
631 assert_locked_or_safepoint(SystemDictionary_lock);
632 assert(index == index_for(protection_domain), "incorrect index?");
633 assert(find_entry(index, protection_domain) == NULL, "no double entry");
634
635 ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
636 Hashtable<oop, mtClass>::add_entry(index, p);
637 return p;
638 }
639
640 void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
641 unsigned int hash = compute_hash(Handle(Thread::current(), to_delete->protection_domain()));
642 int index = hash_to_index(hash);
643
644 ProtectionDomainCacheEntry** p = bucket_addr(index);
645 ProtectionDomainCacheEntry* entry = bucket(index);
646 while (true) {
647 assert(entry != NULL, "sanity");
648
649 if (entry == to_delete) {
650 *p = entry->next();
651 Hashtable<oop, mtClass>::free_entry(entry);
652 break;
653 } else {
654 p = entry->next_addr();
655 entry = *p;
656 }
657 }
658 }
659
660 SymbolPropertyTable::SymbolPropertyTable(int table_size)
661 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
662 {
663 }
664 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
665 int number_of_entries)
666 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
667 {
668 }
669
670
671 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
672 Symbol* sym,
673 intptr_t sym_mode) {
674 assert(index == index_for(sym, sym_mode), "incorrect index?");
675 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
676 if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
677 return p;
678 }
679 }
680 return NULL;
681 }
682
683
684 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
685 Symbol* sym, intptr_t sym_mode) {
686 assert_locked_or_safepoint(SystemDictionary_lock);
687 assert(index == index_for(sym, sym_mode), "incorrect index?");
688 assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
689
690 SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
691 Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
692 return p;
693 }
694
695 void SymbolPropertyTable::oops_do(OopClosure* f) {
696 for (int index = 0; index < table_size(); index++) {
697 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
698 if (p->method_type() != NULL) {
699 f->do_oop(p->method_type_addr());
700 }
701 }
702 }
703 }
704
705 void SymbolPropertyTable::methods_do(void f(Method*)) {
706 for (int index = 0; index < table_size(); index++) {
707 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
708 Method* prop = p->method();
709 if (prop != NULL) {
710 f((Method*)prop);
711 }
712 }
713 }
714 }
715
716
717 // ----------------------------------------------------------------------------
718
719 void Dictionary::print(bool details) {
720 ResourceMark rm;
721
722 if (details) {
723 tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
724 table_size(), number_of_entries());
725 tty->print_cr("^ indicates that initiating loader is different from "
726 "defining loader");
727 }
728
729 for (int index = 0; index < table_size(); index++) {
730 for (DictionaryEntry* probe = bucket(index);
731 probe != NULL;
732 probe = probe->next()) {
733 Klass* e = probe->klass();
734 ClassLoaderData* loader_data = probe->loader_data();
735 bool is_defining_class =
736 (loader_data == e->class_loader_data());
737 if (details) {
738 tty->print("%4d: ", index);
739 }
740 tty->print("%s%s", ((!details) || is_defining_class) ? " " : "^",
741 e->external_name());
742
743 if (details) {
744 tty->print(", loader ");
745 if (loader_data != NULL) {
746 loader_data->print_value();
747 } else {
748 tty->print("NULL");
749 }
750 }
751 tty->cr();
752 }
753 }
754
755 if (details) {
756 tty->cr();
757 _pd_cache_table->print();
758 }
759 tty->cr();
760 }
761
762 #ifdef ASSERT
763 void Dictionary::printPerformanceInfoDetails() {
764 if (log_is_enabled(Info, hashtables)) {
765 ResourceMark rm;
766
767 log_info(hashtables)(" ");
768 log_info(hashtables)("Java system dictionary (table_size=%d, classes=%d)",
769 table_size(), number_of_entries());
770 log_info(hashtables)("1st number: the bucket index");
771 log_info(hashtables)("2nd number: the hit percentage for this bucket");
772 log_info(hashtables)("3rd number: the entry's index within this bucket");
773 log_info(hashtables)("4th number: the hash index of this entry");
774 log_info(hashtables)(" ");
775
776 // find top buckets with highest lookup count
777 #define TOP_COUNT 16
778 int topItemsIndicies[TOP_COUNT];
779 for (int i = 0; i < TOP_COUNT; i++) {
780 topItemsIndicies[i] = i;
781 }
782 double total = 0.0;
783 for (int i = 0; i < table_size(); i++) {
784 // find the total count number, so later on we can
785 // express bucket lookup count as a percentage of all lookups
786 unsigned value = bucket_hits(i);
787 total += value;
788
789 // find the top entry with min value
790 int min_index = 0;
791 unsigned min_value = bucket_hits(topItemsIndicies[min_index]);
792 for (int j = 1; j < TOP_COUNT; j++) {
793 unsigned top_value = bucket_hits(topItemsIndicies[j]);
794 if (top_value < min_value) {
795 min_value = top_value;
796 min_index = j;
797 }
798 }
799 // if the bucket loookup value is bigger than the top buckets min
800 // move that bucket index into the top list
801 if (value > min_value) {
802 topItemsIndicies[min_index] = i;
803 }
804 }
805
806 for (int index = 0; index < table_size(); index++) {
807 double percentage = 100.0 * (double)bucket_hits(index)/total;
808 int chain = 0;
809 for (DictionaryEntry* probe = bucket(index);
810 probe != NULL;
811 probe = probe->next()) {
812 Klass* e = probe->klass();
813 ClassLoaderData* loader_data = probe->loader_data();
814 bool is_defining_class =
815 (loader_data == e->class_loader_data());
816 log_info(hashtables)("%4d: %5.2f%%: %3d: %10u: %s, loader %s",
817 index, percentage, chain, probe->hash(), e->external_name(),
818 (loader_data != NULL) ? loader_data->loader_name() : "NULL");
819
820 chain++;
821 }
822 if (chain == 0) {
823 log_info(hashtables)("%4d:", index+1);
824 }
825 }
826 log_info(hashtables)(" ");
827
828 // print out the TOP_COUNT of buckets with highest lookup count (unsorted)
829 log_info(hashtables)("Top %d buckets:", TOP_COUNT);
830 for (int i = 0; i < TOP_COUNT; i++) {
831 log_info(hashtables)("%4d: hits %5.2f%%",
832 topItemsIndicies[i],
833 100.0*(double)bucket_hits(topItemsIndicies[i])/total);
834 }
835 }
836 }
837 #endif // ASSERT
838
839 void Dictionary::verify() {
840 guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
841
842 int element_count = 0;
843 for (int index = 0; index < table_size(); index++) {
844 for (DictionaryEntry* probe = bucket(index);
845 probe != NULL;
846 probe = probe->next()) {
847 Klass* e = probe->klass();
848 ClassLoaderData* loader_data = probe->loader_data();
849 guarantee(e->is_instance_klass(),
850 "Verify of system dictionary failed");
851 // class loader must be present; a null class loader is the
852 // boostrap loader
853 guarantee(loader_data != NULL || DumpSharedSpaces ||
854 loader_data->class_loader() == NULL ||
855 loader_data->class_loader()->is_instance(),
856 "checking type of class_loader");
857 e->verify();
858 probe->verify_protection_domain_set();
859 element_count++;
860 }
861 }
862 guarantee(number_of_entries() == element_count,
863 "Verify of system dictionary failed");
864 #ifdef ASSERT
865 if (!verify_lookup_length((double)number_of_entries() / table_size(), "System Dictionary")) {
866 this->printPerformanceInfoDetails();
867 }
868 #endif // ASSERT
869
870 _pd_cache_table->verify();
871 }
872