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<InstanceKlass*, 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<InstanceKlass*, 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, InstanceKlass* klass,
69 ClassLoaderData* loader_data) {
70 DictionaryEntry* entry = (DictionaryEntry*)Hashtable<InstanceKlass*, 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<InstanceKlass*, 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::methods_do(void f(Method*)) {
335 for (int index = 0; index < table_size(); index++) {
336 for (DictionaryEntry* probe = bucket(index);
337 probe != NULL;
338 probe = probe->next()) {
339 Klass* k = probe->klass();
340 if (probe->loader_data() == k->class_loader_data()) {
341 // only take klass is we have the entry with the defining class loader
342 InstanceKlass::cast(k)->methods_do(f);
343 }
344 }
345 }
346 }
347
348 void Dictionary::unlink(BoolObjectClosure* is_alive) {
349 // Only the protection domain cache table may contain references to the heap
350 // that need to be unlinked.
351 _pd_cache_table->unlink(is_alive);
352 }
353
354 InstanceKlass* Dictionary::try_get_next_class() {
355 while (true) {
356 if (_current_class_entry != NULL) {
357 InstanceKlass* k = _current_class_entry->klass();
358 _current_class_entry = _current_class_entry->next();
359 return k;
360 }
361 _current_class_index = (_current_class_index + 1) % table_size();
362 _current_class_entry = bucket(_current_class_index);
363 }
364 // never reached
365 }
366
367 // Add a loaded class to the system dictionary.
368 // Readers of the SystemDictionary aren't always locked, so _buckets
369 // is volatile. The store of the next field in the constructor is
370 // also cast to volatile; we do this to ensure store order is maintained
371 // by the compilers.
372
373 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
374 InstanceKlass* obj) {
375 assert_locked_or_safepoint(SystemDictionary_lock);
376 assert(obj != NULL, "adding NULL obj");
377 assert(obj->name() == class_name, "sanity check on name");
378 assert(loader_data != NULL, "Must be non-NULL");
379
380 unsigned int hash = compute_hash(class_name, loader_data);
381 int index = hash_to_index(hash);
382 DictionaryEntry* entry = new_entry(hash, obj, loader_data);
383 add_entry(index, entry);
384 }
385
386
387 // This routine does not lock the system dictionary.
388 //
389 // Since readers don't hold a lock, we must make sure that system
390 // dictionary entries are only removed at a safepoint (when only one
391 // thread is running), and are added to in a safe way (all links must
392 // be updated in an MT-safe manner).
393 //
394 // Callers should be aware that an entry could be added just after
395 // _buckets[index] is read here, so the caller will not see the new entry.
396 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
397 Symbol* class_name,
398 ClassLoaderData* loader_data) {
399 DEBUG_ONLY(_lookup_count++);
400 for (DictionaryEntry* entry = bucket(index);
401 entry != NULL;
402 entry = entry->next()) {
403 if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
404 DEBUG_ONLY(bucket_count_hit(index));
405 return entry;
406 }
407 DEBUG_ONLY(_lookup_length++);
408 }
409 return NULL;
410 }
411
412
413 InstanceKlass* Dictionary::find(int index, unsigned int hash, Symbol* name,
414 ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
415 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
416 if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
417 return entry->klass();
418 } else {
419 return NULL;
420 }
421 }
422
423
424 InstanceKlass* Dictionary::find_class(int index, unsigned int hash,
425 Symbol* name, ClassLoaderData* loader_data) {
426 assert_locked_or_safepoint(SystemDictionary_lock);
427 assert (index == index_for(name, loader_data), "incorrect index?");
428
429 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
430 return (entry != NULL) ? entry->klass() : NULL;
431 }
432
433
434 // Variant of find_class for shared classes. No locking required, as
435 // that table is static.
436
437 InstanceKlass* Dictionary::find_shared_class(int index, unsigned int hash,
438 Symbol* name) {
439 assert (index == index_for(name, NULL), "incorrect index?");
440
441 DictionaryEntry* entry = get_entry(index, hash, name, NULL);
442 return (entry != NULL) ? entry->klass() : NULL;
443 }
444
445
446 void Dictionary::add_protection_domain(int index, unsigned int hash,
447 InstanceKlass* klass,
448 ClassLoaderData* loader_data, Handle protection_domain,
449 TRAPS) {
450 Symbol* klass_name = klass->name();
451 DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);
452
453 assert(entry != NULL,"entry must be present, we just created it");
454 assert(protection_domain() != NULL,
455 "real protection domain should be present");
456
457 entry->add_protection_domain(this, protection_domain);
458
459 assert(entry->contains_protection_domain(protection_domain()),
460 "now protection domain should be present");
461 }
462
463
464 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
465 Symbol* name,
466 ClassLoaderData* loader_data,
467 Handle protection_domain) {
468 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
469 return entry->is_valid_protection_domain(protection_domain);
470 }
471
472
473 void Dictionary::reorder_dictionary() {
474
475 // Copy all the dictionary entries into a single master list.
476
477 DictionaryEntry* master_list = NULL;
478 for (int i = 0; i < table_size(); ++i) {
479 DictionaryEntry* p = bucket(i);
480 while (p != NULL) {
481 DictionaryEntry* tmp;
482 tmp = p->next();
483 p->set_next(master_list);
484 master_list = p;
485 p = tmp;
486 }
487 set_entry(i, NULL);
488 }
489
490 // Add the dictionary entries back to the list in the correct buckets.
491 while (master_list != NULL) {
492 DictionaryEntry* p = master_list;
493 master_list = master_list->next();
494 p->set_next(NULL);
495 Symbol* class_name = p->klass()->name();
496 // Since the null class loader data isn't copied to the CDS archive,
497 // compute the hash with NULL for loader data.
498 unsigned int hash = compute_hash(class_name, NULL);
499 int index = hash_to_index(hash);
500 p->set_hash(hash);
501 p->set_loader_data(NULL); // loader_data isn't copied to CDS
502 p->set_next(bucket(index));
503 set_entry(index, p);
504 }
505 }
506
507
508 unsigned int ProtectionDomainCacheTable::compute_hash(Handle protection_domain) {
509 // Identity hash can safepoint, so keep protection domain in a Handle.
510 return (unsigned int)(protection_domain->identity_hash());
511 }
512
513 int ProtectionDomainCacheTable::index_for(Handle protection_domain) {
514 return hash_to_index(compute_hash(protection_domain));
515 }
516
517 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
518 : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
519 {
520 }
521
522 void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
523 assert(SafepointSynchronize::is_at_safepoint(), "must be");
524 for (int i = 0; i < table_size(); ++i) {
525 ProtectionDomainCacheEntry** p = bucket_addr(i);
526 ProtectionDomainCacheEntry* entry = bucket(i);
527 while (entry != NULL) {
528 if (is_alive->do_object_b(entry->literal())) {
529 p = entry->next_addr();
530 } else {
531 *p = entry->next();
532 free_entry(entry);
533 }
534 entry = *p;
535 }
536 }
537 }
538
539 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
540 for (int index = 0; index < table_size(); index++) {
541 for (ProtectionDomainCacheEntry* probe = bucket(index);
542 probe != NULL;
543 probe = probe->next()) {
544 probe->oops_do(f);
545 }
546 }
547 }
548
549 void ProtectionDomainCacheTable::roots_oops_do(OopClosure* strong, OopClosure* weak) {
550 for (int index = 0; index < table_size(); index++) {
551 for (ProtectionDomainCacheEntry* probe = bucket(index);
552 probe != NULL;
553 probe = probe->next()) {
554 if (probe->is_strongly_reachable()) {
555 probe->reset_strongly_reachable();
556 probe->oops_do(strong);
557 } else {
558 if (weak != NULL) {
559 probe->oops_do(weak);
560 }
561 }
562 }
563 }
564 }
565
566 uint ProtectionDomainCacheTable::bucket_size() {
567 return sizeof(ProtectionDomainCacheEntry);
568 }
569
570 #ifndef PRODUCT
571 void ProtectionDomainCacheTable::print() {
572 tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
573 table_size(), number_of_entries());
574 for (int index = 0; index < table_size(); index++) {
575 for (ProtectionDomainCacheEntry* probe = bucket(index);
576 probe != NULL;
577 probe = probe->next()) {
578 probe->print();
579 }
580 }
581 }
582
583 void ProtectionDomainCacheEntry::print() {
584 tty->print_cr("entry " PTR_FORMAT " value " PTR_FORMAT " strongly_reachable %d next " PTR_FORMAT,
585 p2i(this), p2i(literal()), _strongly_reachable, p2i(next()));
586 }
587 #endif
588
589 void ProtectionDomainCacheTable::verify() {
590 int element_count = 0;
591 for (int index = 0; index < table_size(); index++) {
592 for (ProtectionDomainCacheEntry* probe = bucket(index);
593 probe != NULL;
594 probe = probe->next()) {
595 probe->verify();
596 element_count++;
597 }
598 }
599 guarantee(number_of_entries() == element_count,
600 "Verify of protection domain cache table failed");
601 DEBUG_ONLY(verify_lookup_length((double)number_of_entries() / table_size(), "Domain Cache Table"));
602 }
603
604 void ProtectionDomainCacheEntry::verify() {
605 guarantee(literal()->is_oop(), "must be an oop");
606 }
607
608 void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
609 // the caller marked the protection domain cache entries that we need to apply
610 // the closure on. Only process them.
611 for (int index = 0; index < table_size(); index++) {
612 for (ProtectionDomainCacheEntry* probe = bucket(index);
613 probe != NULL;
614 probe = probe->next()) {
615 if (probe->is_strongly_reachable()) {
616 probe->reset_strongly_reachable();
617 probe->oops_do(f);
618 }
619 }
620 }
621 }
622
623 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(Handle protection_domain) {
624 unsigned int hash = compute_hash(protection_domain);
625 int index = hash_to_index(hash);
626
627 ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
628 if (entry == NULL) {
629 entry = add_entry(index, hash, protection_domain);
630 }
631 return entry;
632 }
633
634 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, Handle protection_domain) {
635 for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
636 if (e->protection_domain() == protection_domain()) {
637 return e;
638 }
639 }
640
641 return NULL;
642 }
643
644 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, Handle protection_domain) {
645 assert_locked_or_safepoint(SystemDictionary_lock);
646 assert(index == index_for(protection_domain), "incorrect index?");
647 assert(find_entry(index, protection_domain) == NULL, "no double entry");
648
649 ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
650 Hashtable<oop, mtClass>::add_entry(index, p);
651 return p;
652 }
653
654 void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
655 unsigned int hash = compute_hash(Handle(Thread::current(), to_delete->protection_domain()));
656 int index = hash_to_index(hash);
657
658 ProtectionDomainCacheEntry** p = bucket_addr(index);
659 ProtectionDomainCacheEntry* entry = bucket(index);
660 while (true) {
661 assert(entry != NULL, "sanity");
662
663 if (entry == to_delete) {
664 *p = entry->next();
665 Hashtable<oop, mtClass>::free_entry(entry);
666 break;
667 } else {
668 p = entry->next_addr();
669 entry = *p;
670 }
671 }
672 }
673
674 SymbolPropertyTable::SymbolPropertyTable(int table_size)
675 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
676 {
677 }
678 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
679 int number_of_entries)
680 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
681 {
682 }
683
684
685 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
686 Symbol* sym,
687 intptr_t sym_mode) {
688 assert(index == index_for(sym, sym_mode), "incorrect index?");
689 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
690 if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
691 return p;
692 }
693 }
694 return NULL;
695 }
696
697
698 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
699 Symbol* sym, intptr_t sym_mode) {
700 assert_locked_or_safepoint(SystemDictionary_lock);
701 assert(index == index_for(sym, sym_mode), "incorrect index?");
702 assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
703
704 SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
705 Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
706 return p;
707 }
708
709 void SymbolPropertyTable::oops_do(OopClosure* f) {
710 for (int index = 0; index < table_size(); index++) {
711 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
712 if (p->method_type() != NULL) {
713 f->do_oop(p->method_type_addr());
714 }
715 }
716 }
717 }
718
719 void SymbolPropertyTable::methods_do(void f(Method*)) {
720 for (int index = 0; index < table_size(); index++) {
721 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
722 Method* prop = p->method();
723 if (prop != NULL) {
724 f((Method*)prop);
725 }
726 }
727 }
728 }
729
730
731 // ----------------------------------------------------------------------------
732
733 void Dictionary::print(bool details) {
734 ResourceMark rm;
735
736 if (details) {
737 tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
738 table_size(), number_of_entries());
739 tty->print_cr("^ indicates that initiating loader is different from "
740 "defining loader");
741 }
742
743 for (int index = 0; index < table_size(); index++) {
744 for (DictionaryEntry* probe = bucket(index);
745 probe != NULL;
746 probe = probe->next()) {
747 Klass* e = probe->klass();
748 ClassLoaderData* loader_data = probe->loader_data();
749 bool is_defining_class =
750 (loader_data == e->class_loader_data());
751 if (details) {
752 tty->print("%4d: ", index);
753 }
754 tty->print("%s%s", ((!details) || is_defining_class) ? " " : "^",
755 e->external_name());
756
757 if (details) {
758 tty->print(", loader ");
759 if (loader_data != NULL) {
760 loader_data->print_value();
761 } else {
762 tty->print("NULL");
763 }
764 }
765 tty->cr();
766 }
767 }
768
769 if (details) {
770 tty->cr();
771 _pd_cache_table->print();
772 }
773 tty->cr();
774 }
775
776 #ifdef ASSERT
777 void Dictionary::printPerformanceInfoDetails() {
778 if (log_is_enabled(Info, hashtables)) {
779 ResourceMark rm;
780
781 log_info(hashtables)(" ");
782 log_info(hashtables)("Java system dictionary (table_size=%d, classes=%d)",
783 table_size(), number_of_entries());
784 log_info(hashtables)("1st number: the bucket index");
785 log_info(hashtables)("2nd number: the hit percentage for this bucket");
786 log_info(hashtables)("3rd number: the entry's index within this bucket");
787 log_info(hashtables)("4th number: the hash index of this entry");
788 log_info(hashtables)(" ");
789
790 // find top buckets with highest lookup count
791 #define TOP_COUNT 16
792 int topItemsIndicies[TOP_COUNT];
793 for (int i = 0; i < TOP_COUNT; i++) {
794 topItemsIndicies[i] = i;
795 }
796 double total = 0.0;
797 for (int i = 0; i < table_size(); i++) {
798 // find the total count number, so later on we can
799 // express bucket lookup count as a percentage of all lookups
800 unsigned value = bucket_hits(i);
801 total += value;
802
803 // find the top entry with min value
804 int min_index = 0;
805 unsigned min_value = bucket_hits(topItemsIndicies[min_index]);
806 for (int j = 1; j < TOP_COUNT; j++) {
807 unsigned top_value = bucket_hits(topItemsIndicies[j]);
808 if (top_value < min_value) {
809 min_value = top_value;
810 min_index = j;
811 }
812 }
813 // if the bucket loookup value is bigger than the top buckets min
814 // move that bucket index into the top list
815 if (value > min_value) {
816 topItemsIndicies[min_index] = i;
817 }
818 }
819
820 for (int index = 0; index < table_size(); index++) {
821 double percentage = 100.0 * (double)bucket_hits(index)/total;
822 int chain = 0;
823 for (DictionaryEntry* probe = bucket(index);
824 probe != NULL;
825 probe = probe->next()) {
826 Klass* e = probe->klass();
827 ClassLoaderData* loader_data = probe->loader_data();
828 bool is_defining_class =
829 (loader_data == e->class_loader_data());
830 log_info(hashtables)("%4d: %5.2f%%: %3d: %10u: %s, loader %s",
831 index, percentage, chain, probe->hash(), e->external_name(),
832 (loader_data != NULL) ? loader_data->loader_name() : "NULL");
833
834 chain++;
835 }
836 if (chain == 0) {
837 log_info(hashtables)("%4d:", index+1);
838 }
839 }
840 log_info(hashtables)(" ");
841
842 // print out the TOP_COUNT of buckets with highest lookup count (unsorted)
843 log_info(hashtables)("Top %d buckets:", TOP_COUNT);
844 for (int i = 0; i < TOP_COUNT; i++) {
845 log_info(hashtables)("%4d: hits %5.2f%%",
846 topItemsIndicies[i],
847 100.0*(double)bucket_hits(topItemsIndicies[i])/total);
848 }
849 }
850 }
851 #endif // ASSERT
852
853 void Dictionary::verify() {
854 guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
855
856 int element_count = 0;
857 for (int index = 0; index < table_size(); index++) {
858 for (DictionaryEntry* probe = bucket(index);
859 probe != NULL;
860 probe = probe->next()) {
861 Klass* e = probe->klass();
862 ClassLoaderData* loader_data = probe->loader_data();
863 guarantee(e->is_instance_klass(),
864 "Verify of system dictionary failed");
865 // class loader must be present; a null class loader is the
866 // boostrap loader
867 guarantee(loader_data != NULL || DumpSharedSpaces ||
868 loader_data->class_loader() == NULL ||
869 loader_data->class_loader()->is_instance(),
870 "checking type of class_loader");
871 e->verify();
872 probe->verify_protection_domain_set();
873 element_count++;
874 }
875 }
876 guarantee(number_of_entries() == element_count,
877 "Verify of system dictionary failed");
878 #ifdef ASSERT
879 if (!verify_lookup_length((double)number_of_entries() / table_size(), "System Dictionary")) {
880 this->printPerformanceInfoDetails();
881 }
882 #endif // ASSERT
883
884 _pd_cache_table->verify();
885 }
886