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 ResourceMark rm;
181 tty->print_cr("loader data %s loads class %s in loader data %s",
182 loader_data->loader_name(),
183 ik->name()->as_C_string(), k_def_class_loader_data->loader_name());
184 ShouldNotReachHere(); // isn't there a dependency created? or k_loader_data is parent of loader_data??
185 // If we get here, the class_loader_data must not be the defining
186 // loader, it must be an initiating one.
187 assert(k_def_class_loader_data != loader_data,
188 "cannot have live defining loader and unreachable klass");
189 // Loader is live, but class and its defining loader are dead.
190 // Remove the entry. The class is going away.
191 purge_entry = true;
192 }
193 }
194
195 if (purge_entry) {
196 *p = probe->next();
197 if (probe == _current_class_entry) {
198 _current_class_entry = NULL;
199 }
200 free_entry(probe);
201 continue;
202 }
203 }
204 p = probe->next_addr();
205 }
206 }
207 }
208
209 void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
210 // Skip the strong roots probe marking if the closures are the same.
211 if (strong == weak) {
212 oops_do(strong);
213 return;
214 }
215
216 for (int index = 0; index < table_size(); index++) {
217 for (DictionaryEntry *probe = bucket(index);
218 probe != NULL;
219 probe = probe->next()) {
220 Klass* e = probe->klass();
221 ClassLoaderData* loader_data = probe->loader_data();
222 if (is_strongly_reachable(loader_data, e)) {
223 probe->set_strongly_reachable();
224 }
225 }
226 }
227 _pd_cache_table->roots_oops_do(strong, weak);
228 }
229
230 void Dictionary::remove_classes_in_error_state() {
231 assert(DumpSharedSpaces, "supported only when dumping");
232 DictionaryEntry* probe = NULL;
233 for (int index = 0; index < table_size(); index++) {
234 for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
235 probe = *p;
236 InstanceKlass* ik = InstanceKlass::cast(probe->klass());
237 if (ik->is_in_error_state()) { // purge this entry
238 *p = probe->next();
239 if (probe == _current_class_entry) {
240 _current_class_entry = NULL;
241 }
242 free_entry(probe);
243 ResourceMark rm;
244 tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
245 continue;
246 }
247
248 p = probe->next_addr();
249 }
250 }
251 }
252
253 void Dictionary::always_strong_oops_do(OopClosure* blk) {
254 // Follow all system classes and temporary placeholders in dictionary; only
255 // protection domain oops contain references into the heap. In a first
256 // pass over the system dictionary determine which need to be treated as
257 // strongly reachable and mark them as such.
258 for (int index = 0; index < table_size(); index++) {
259 for (DictionaryEntry *probe = bucket(index);
260 probe != NULL;
261 probe = probe->next()) {
262 Klass* e = probe->klass();
263 ClassLoaderData* loader_data = probe->loader_data();
264 if (is_strongly_reachable(loader_data, e)) {
265 probe->set_strongly_reachable();
266 }
267 }
268 }
269 // Then iterate over the protection domain cache to apply the closure on the
270 // previously marked ones.
271 _pd_cache_table->always_strong_oops_do(blk);
272 }
273
274 // Just the classes from defining class loaders
275 void Dictionary::classes_do(void f(Klass*)) {
276 for (int index = 0; index < table_size(); index++) {
277 for (DictionaryEntry* probe = bucket(index);
278 probe != NULL;
279 probe = probe->next()) {
280 Klass* k = probe->klass();
281 if (probe->loader_data() == k->class_loader_data()) {
282 f(k);
283 }
284 }
285 }
286 }
287
288 // Added for initialize_itable_for_klass to handle exceptions
289 // Just the classes from defining class loaders
290 void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
291 for (int index = 0; index < table_size(); index++) {
292 for (DictionaryEntry* probe = bucket(index);
293 probe != NULL;
294 probe = probe->next()) {
295 Klass* k = probe->klass();
296 if (probe->loader_data() == k->class_loader_data()) {
297 f(k, CHECK);
298 }
299 }
300 }
301 }
302
303 // All classes, and their class loaders
304 // Don't iterate over placeholders
305 void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
306 for (int index = 0; index < table_size(); index++) {
307 for (DictionaryEntry* probe = bucket(index);
308 probe != NULL;
309 probe = probe->next()) {
310 Klass* k = probe->klass();
311 f(k, probe->loader_data());
312 }
313 }
314 }
315
316 void Dictionary::oops_do(OopClosure* f) {
317 // Only the protection domain oops contain references into the heap. Iterate
318 // over all of them.
319 _pd_cache_table->oops_do(f);
320 }
321
322 void Dictionary::unlink(BoolObjectClosure* is_alive) {
323 // Only the protection domain cache table may contain references to the heap
324 // that need to be unlinked.
325 _pd_cache_table->unlink(is_alive);
326 }
327
328 InstanceKlass* Dictionary::try_get_next_class() {
329 while (true) {
330 if (_current_class_entry != NULL) {
331 InstanceKlass* k = _current_class_entry->klass();
332 _current_class_entry = _current_class_entry->next();
333 return k;
334 }
335 _current_class_index = (_current_class_index + 1) % table_size();
336 _current_class_entry = bucket(_current_class_index);
337 }
338 // never reached
339 }
340
341 // Add a loaded class to the system dictionary.
342 // Readers of the SystemDictionary aren't always locked, so _buckets
343 // is volatile. The store of the next field in the constructor is
344 // also cast to volatile; we do this to ensure store order is maintained
345 // by the compilers.
346
347 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
348 InstanceKlass* obj) {
349 assert_locked_or_safepoint(SystemDictionary_lock);
350 assert(obj != NULL, "adding NULL obj");
351 assert(obj->name() == class_name, "sanity check on name");
352 assert(loader_data != NULL, "Must be non-NULL");
353
354 unsigned int hash = compute_hash(class_name, loader_data);
355 int index = hash_to_index(hash);
356 DictionaryEntry* entry = new_entry(hash, obj, loader_data);
357 add_entry(index, entry);
358 }
359
360
361 // This routine does not lock the system dictionary.
362 //
363 // Since readers don't hold a lock, we must make sure that system
364 // dictionary entries are only removed at a safepoint (when only one
365 // thread is running), and are added to in a safe way (all links must
366 // be updated in an MT-safe manner).
367 //
368 // Callers should be aware that an entry could be added just after
369 // _buckets[index] is read here, so the caller will not see the new entry.
370 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
371 Symbol* class_name,
372 ClassLoaderData* loader_data) {
373 DEBUG_ONLY(_lookup_count++);
374 for (DictionaryEntry* entry = bucket(index);
375 entry != NULL;
376 entry = entry->next()) {
377 if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
378 DEBUG_ONLY(bucket_count_hit(index));
379 return entry;
380 }
381 DEBUG_ONLY(_lookup_length++);
382 }
383 return NULL;
384 }
385
386
387 InstanceKlass* Dictionary::find(int index, unsigned int hash, Symbol* name,
388 ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
389 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
390 if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
391 return entry->klass();
392 } else {
393 return NULL;
394 }
395 }
396
397
398 InstanceKlass* Dictionary::find_class(int index, unsigned int hash,
399 Symbol* name, ClassLoaderData* loader_data) {
400 assert_locked_or_safepoint(SystemDictionary_lock);
401 assert (index == index_for(name, loader_data), "incorrect index?");
402
403 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
404 return (entry != NULL) ? entry->klass() : NULL;
405 }
406
407
408 // Variant of find_class for shared classes. No locking required, as
409 // that table is static.
410
411 InstanceKlass* Dictionary::find_shared_class(int index, unsigned int hash,
412 Symbol* name) {
413 assert (index == index_for(name, NULL), "incorrect index?");
414
415 DictionaryEntry* entry = get_entry(index, hash, name, NULL);
416 return (entry != NULL) ? entry->klass() : NULL;
417 }
418
419
420 void Dictionary::add_protection_domain(int index, unsigned int hash,
421 InstanceKlass* klass,
422 ClassLoaderData* loader_data, Handle protection_domain,
423 TRAPS) {
424 Symbol* klass_name = klass->name();
425 DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);
426
427 assert(entry != NULL,"entry must be present, we just created it");
428 assert(protection_domain() != NULL,
429 "real protection domain should be present");
430
431 entry->add_protection_domain(this, protection_domain);
432
433 assert(entry->contains_protection_domain(protection_domain()),
434 "now protection domain should be present");
435 }
436
437
438 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
439 Symbol* name,
440 ClassLoaderData* loader_data,
441 Handle protection_domain) {
442 DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
443 return entry->is_valid_protection_domain(protection_domain);
444 }
445
446
447 void Dictionary::reorder_dictionary() {
448
449 // Copy all the dictionary entries into a single master list.
450
451 DictionaryEntry* master_list = NULL;
452 for (int i = 0; i < table_size(); ++i) {
453 DictionaryEntry* p = bucket(i);
454 while (p != NULL) {
455 DictionaryEntry* tmp;
456 tmp = p->next();
457 p->set_next(master_list);
458 master_list = p;
459 p = tmp;
460 }
461 set_entry(i, NULL);
462 }
463
464 // Add the dictionary entries back to the list in the correct buckets.
465 while (master_list != NULL) {
466 DictionaryEntry* p = master_list;
467 master_list = master_list->next();
468 p->set_next(NULL);
469 Symbol* class_name = p->klass()->name();
470 // Since the null class loader data isn't copied to the CDS archive,
471 // compute the hash with NULL for loader data.
472 unsigned int hash = compute_hash(class_name, NULL);
473 int index = hash_to_index(hash);
474 p->set_hash(hash);
475 p->set_loader_data(NULL); // loader_data isn't copied to CDS
476 p->set_next(bucket(index));
477 set_entry(index, p);
478 }
479 }
480
481
482 unsigned int ProtectionDomainCacheTable::compute_hash(Handle protection_domain) {
483 // Identity hash can safepoint, so keep protection domain in a Handle.
484 return (unsigned int)(protection_domain->identity_hash());
485 }
486
487 int ProtectionDomainCacheTable::index_for(Handle protection_domain) {
488 return hash_to_index(compute_hash(protection_domain));
489 }
490
491 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
492 : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
493 {
494 }
495
496 void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
497 assert(SafepointSynchronize::is_at_safepoint(), "must be");
498 for (int i = 0; i < table_size(); ++i) {
499 ProtectionDomainCacheEntry** p = bucket_addr(i);
500 ProtectionDomainCacheEntry* entry = bucket(i);
501 while (entry != NULL) {
502 if (is_alive->do_object_b(entry->literal())) {
503 p = entry->next_addr();
504 } else {
505 *p = entry->next();
506 free_entry(entry);
507 }
508 entry = *p;
509 }
510 }
511 }
512
513 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
514 for (int index = 0; index < table_size(); index++) {
515 for (ProtectionDomainCacheEntry* probe = bucket(index);
516 probe != NULL;
517 probe = probe->next()) {
518 probe->oops_do(f);
519 }
520 }
521 }
522
523 void ProtectionDomainCacheTable::roots_oops_do(OopClosure* strong, OopClosure* weak) {
524 for (int index = 0; index < table_size(); index++) {
525 for (ProtectionDomainCacheEntry* probe = bucket(index);
526 probe != NULL;
527 probe = probe->next()) {
528 if (probe->is_strongly_reachable()) {
529 probe->reset_strongly_reachable();
530 probe->oops_do(strong);
531 } else {
532 if (weak != NULL) {
533 probe->oops_do(weak);
534 }
535 }
536 }
537 }
538 }
539
540 uint ProtectionDomainCacheTable::bucket_size() {
541 return sizeof(ProtectionDomainCacheEntry);
542 }
543
544 #ifndef PRODUCT
545 void ProtectionDomainCacheTable::print() {
546 tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
547 table_size(), number_of_entries());
548 for (int index = 0; index < table_size(); index++) {
549 for (ProtectionDomainCacheEntry* probe = bucket(index);
550 probe != NULL;
551 probe = probe->next()) {
552 probe->print();
553 }
554 }
555 }
556
557 void ProtectionDomainCacheEntry::print() {
558 tty->print_cr("entry " PTR_FORMAT " value " PTR_FORMAT " strongly_reachable %d next " PTR_FORMAT,
559 p2i(this), p2i(literal()), _strongly_reachable, p2i(next()));
560 }
561 #endif
562
563 void ProtectionDomainCacheTable::verify() {
564 int element_count = 0;
565 for (int index = 0; index < table_size(); index++) {
566 for (ProtectionDomainCacheEntry* probe = bucket(index);
567 probe != NULL;
568 probe = probe->next()) {
569 probe->verify();
570 element_count++;
571 }
572 }
573 guarantee(number_of_entries() == element_count,
574 "Verify of protection domain cache table failed");
575 DEBUG_ONLY(verify_lookup_length((double)number_of_entries() / table_size(), "Domain Cache Table"));
576 }
577
578 void ProtectionDomainCacheEntry::verify() {
579 guarantee(literal()->is_oop(), "must be an oop");
580 }
581
582 void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
583 // the caller marked the protection domain cache entries that we need to apply
584 // the closure on. Only process them.
585 for (int index = 0; index < table_size(); index++) {
586 for (ProtectionDomainCacheEntry* probe = bucket(index);
587 probe != NULL;
588 probe = probe->next()) {
589 if (probe->is_strongly_reachable()) {
590 probe->reset_strongly_reachable();
591 probe->oops_do(f);
592 }
593 }
594 }
595 }
596
597 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(Handle protection_domain) {
598 unsigned int hash = compute_hash(protection_domain);
599 int index = hash_to_index(hash);
600
601 ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
602 if (entry == NULL) {
603 entry = add_entry(index, hash, protection_domain);
604 }
605 return entry;
606 }
607
608 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, Handle protection_domain) {
609 for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
610 if (e->protection_domain() == protection_domain()) {
611 return e;
612 }
613 }
614
615 return NULL;
616 }
617
618 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, Handle protection_domain) {
619 assert_locked_or_safepoint(SystemDictionary_lock);
620 assert(index == index_for(protection_domain), "incorrect index?");
621 assert(find_entry(index, protection_domain) == NULL, "no double entry");
622
623 ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
624 Hashtable<oop, mtClass>::add_entry(index, p);
625 return p;
626 }
627
628
629 SymbolPropertyTable::SymbolPropertyTable(int table_size)
630 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
631 {
632 }
633 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
634 int number_of_entries)
635 : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
636 {
637 }
638
639
640 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
641 Symbol* sym,
642 intptr_t sym_mode) {
643 assert(index == index_for(sym, sym_mode), "incorrect index?");
644 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
645 if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
646 return p;
647 }
648 }
649 return NULL;
650 }
651
652
653 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
654 Symbol* sym, intptr_t sym_mode) {
655 assert_locked_or_safepoint(SystemDictionary_lock);
656 assert(index == index_for(sym, sym_mode), "incorrect index?");
657 assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
658
659 SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
660 Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
661 return p;
662 }
663
664 void SymbolPropertyTable::oops_do(OopClosure* f) {
665 for (int index = 0; index < table_size(); index++) {
666 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
667 if (p->method_type() != NULL) {
668 f->do_oop(p->method_type_addr());
669 }
670 }
671 }
672 }
673
674 void SymbolPropertyTable::methods_do(void f(Method*)) {
675 for (int index = 0; index < table_size(); index++) {
676 for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
677 Method* prop = p->method();
678 if (prop != NULL) {
679 f((Method*)prop);
680 }
681 }
682 }
683 }
684
685
686 // ----------------------------------------------------------------------------
687
688 void Dictionary::print(bool details) {
689 ResourceMark rm;
690
691 if (details) {
692 tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
693 table_size(), number_of_entries());
694 tty->print_cr("^ indicates that initiating loader is different from "
695 "defining loader");
696 }
697
698 for (int index = 0; index < table_size(); index++) {
699 for (DictionaryEntry* probe = bucket(index);
700 probe != NULL;
701 probe = probe->next()) {
702 Klass* e = probe->klass();
703 ClassLoaderData* loader_data = probe->loader_data();
704 bool is_defining_class =
705 (loader_data == e->class_loader_data());
706 if (details) {
707 tty->print("%4d: ", index);
708 }
709 tty->print("%s%s", ((!details) || is_defining_class) ? " " : "^",
710 e->external_name());
711
712 if (details) {
713 tty->print(", loader ");
714 if (loader_data != NULL) {
715 loader_data->print_value();
716 } else {
717 tty->print("NULL");
718 }
719 }
720 tty->cr();
721 }
722 }
723
724 if (details) {
725 tty->cr();
726 _pd_cache_table->print();
727 }
728 tty->cr();
729 }
730
731 #ifdef ASSERT
732 void Dictionary::printPerformanceInfoDetails() {
733 if (log_is_enabled(Info, hashtables)) {
734 ResourceMark rm;
735
736 log_info(hashtables)(" ");
737 log_info(hashtables)("Java system dictionary (table_size=%d, classes=%d)",
738 table_size(), number_of_entries());
739 log_info(hashtables)("1st number: the bucket index");
740 log_info(hashtables)("2nd number: the hit percentage for this bucket");
741 log_info(hashtables)("3rd number: the entry's index within this bucket");
742 log_info(hashtables)("4th number: the hash index of this entry");
743 log_info(hashtables)(" ");
744
745 // find top buckets with highest lookup count
746 #define TOP_COUNT 16
747 int topItemsIndicies[TOP_COUNT];
748 for (int i = 0; i < TOP_COUNT; i++) {
749 topItemsIndicies[i] = i;
750 }
751 double total = 0.0;
752 for (int i = 0; i < table_size(); i++) {
753 // find the total count number, so later on we can
754 // express bucket lookup count as a percentage of all lookups
755 unsigned value = bucket_hits(i);
756 total += value;
757
758 // find the top entry with min value
759 int min_index = 0;
760 unsigned min_value = bucket_hits(topItemsIndicies[min_index]);
761 for (int j = 1; j < TOP_COUNT; j++) {
762 unsigned top_value = bucket_hits(topItemsIndicies[j]);
763 if (top_value < min_value) {
764 min_value = top_value;
765 min_index = j;
766 }
767 }
768 // if the bucket loookup value is bigger than the top buckets min
769 // move that bucket index into the top list
770 if (value > min_value) {
771 topItemsIndicies[min_index] = i;
772 }
773 }
774
775 for (int index = 0; index < table_size(); index++) {
776 double percentage = 100.0 * (double)bucket_hits(index)/total;
777 int chain = 0;
778 for (DictionaryEntry* probe = bucket(index);
779 probe != NULL;
780 probe = probe->next()) {
781 Klass* e = probe->klass();
782 ClassLoaderData* loader_data = probe->loader_data();
783 bool is_defining_class =
784 (loader_data == e->class_loader_data());
785 log_info(hashtables)("%4d: %5.2f%%: %3d: %10u: %s, loader %s",
786 index, percentage, chain, probe->hash(), e->external_name(),
787 (loader_data != NULL) ? loader_data->loader_name() : "NULL");
788
789 chain++;
790 }
791 if (chain == 0) {
792 log_info(hashtables)("%4d:", index+1);
793 }
794 }
795 log_info(hashtables)(" ");
796
797 // print out the TOP_COUNT of buckets with highest lookup count (unsorted)
798 log_info(hashtables)("Top %d buckets:", TOP_COUNT);
799 for (int i = 0; i < TOP_COUNT; i++) {
800 log_info(hashtables)("%4d: hits %5.2f%%",
801 topItemsIndicies[i],
802 100.0*(double)bucket_hits(topItemsIndicies[i])/total);
803 }
804 }
805 }
806 #endif // ASSERT
807
808 void Dictionary::verify() {
809 guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
810
811 int element_count = 0;
812 for (int index = 0; index < table_size(); index++) {
813 for (DictionaryEntry* probe = bucket(index);
814 probe != NULL;
815 probe = probe->next()) {
816 Klass* e = probe->klass();
817 ClassLoaderData* loader_data = probe->loader_data();
818 guarantee(e->is_instance_klass(),
819 "Verify of system dictionary failed");
820 // class loader must be present; a null class loader is the
821 // boostrap loader
822 guarantee(loader_data != NULL || DumpSharedSpaces ||
823 loader_data->class_loader() == NULL ||
824 loader_data->class_loader()->is_instance(),
825 "checking type of class_loader");
826 e->verify();
827 probe->verify_protection_domain_set();
828 element_count++;
829 }
830 }
831 guarantee(number_of_entries() == element_count,
832 "Verify of system dictionary failed");
833 #ifdef ASSERT
834 if (!verify_lookup_length((double)number_of_entries() / table_size(), "System Dictionary")) {
835 this->printPerformanceInfoDetails();
836 }
837 #endif // ASSERT
838
839 _pd_cache_table->verify();
840 }
841