1 /*
2 * Copyright (c) 1997, 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/dictionary.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "logging/log.hpp"
32 #include "memory/heapInspection.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "memory/oopFactory.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/atomic.hpp"
42 #include "runtime/orderAccess.inline.hpp"
43 #include "trace/traceMacros.hpp"
44 #include "utilities/macros.hpp"
45 #include "utilities/stack.inline.hpp"
46 #if INCLUDE_ALL_GCS
47 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
48 #endif // INCLUDE_ALL_GCS
49
50 bool Klass::is_cloneable() const {
51 return _access_flags.is_cloneable_fast() ||
52 is_subtype_of(SystemDictionary::Cloneable_klass());
53 }
54
55 void Klass::set_is_cloneable() {
56 if (name() != vmSymbols::java_lang_invoke_MemberName()) {
57 _access_flags.set_is_cloneable_fast();
58 } else {
59 assert(is_final(), "no subclasses allowed");
60 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
61 }
62 }
63
64 void Klass::set_name(Symbol* n) {
65 _name = n;
66 if (_name != NULL) _name->increment_refcount();
67 }
68
69 bool Klass::is_subclass_of(const Klass* k) const {
70 // Run up the super chain and check
71 if (this == k) return true;
72
73 Klass* t = const_cast<Klass*>(this)->super();
74
75 while (t != NULL) {
76 if (t == k) return true;
77 t = t->super();
78 }
79 return false;
80 }
81
82 bool Klass::search_secondary_supers(Klass* k) const {
83 // Put some extra logic here out-of-line, before the search proper.
84 // This cuts down the size of the inline method.
85
86 // This is necessary, since I am never in my own secondary_super list.
87 if (this == k)
88 return true;
89 // Scan the array-of-objects for a match
90 int cnt = secondary_supers()->length();
91 for (int i = 0; i < cnt; i++) {
92 if (secondary_supers()->at(i) == k) {
93 ((Klass*)this)->set_secondary_super_cache(k);
94 return true;
95 }
96 }
97 return false;
98 }
99
100 // Return self, except for abstract classes with exactly 1
101 // implementor. Then return the 1 concrete implementation.
102 Klass *Klass::up_cast_abstract() {
103 Klass *r = this;
104 while( r->is_abstract() ) { // Receiver is abstract?
105 Klass *s = r->subklass(); // Check for exactly 1 subklass
106 if( !s || s->next_sibling() ) // Oops; wrong count; give up
107 return this; // Return 'this' as a no-progress flag
108 r = s; // Loop till find concrete class
109 }
110 return r; // Return the 1 concrete class
111 }
112
113 // Find LCA in class hierarchy
114 Klass *Klass::LCA( Klass *k2 ) {
115 Klass *k1 = this;
116 while( 1 ) {
117 if( k1->is_subtype_of(k2) ) return k2;
118 if( k2->is_subtype_of(k1) ) return k1;
119 k1 = k1->super();
120 k2 = k2->super();
121 }
122 }
123
124
125 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
126 ResourceMark rm(THREAD);
127 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
128 : vmSymbols::java_lang_InstantiationException(), external_name());
129 }
130
131
132 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
133 THROW(vmSymbols::java_lang_ArrayStoreException());
134 }
135
136
137 void Klass::initialize(TRAPS) {
138 ShouldNotReachHere();
139 }
140
141 bool Klass::compute_is_subtype_of(Klass* k) {
142 assert(k->is_klass(), "argument must be a class");
143 return is_subclass_of(k);
144 }
145
146 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
147 #ifdef ASSERT
148 tty->print_cr("Error: find_field called on a klass oop."
149 " Likely error: reflection method does not correctly"
150 " wrap return value in a mirror object.");
151 #endif
152 ShouldNotReachHere();
153 return NULL;
154 }
155
156 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
157 #ifdef ASSERT
158 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
159 " Likely error: reflection method does not correctly"
160 " wrap return value in a mirror object.");
161 #endif
162 ShouldNotReachHere();
163 return NULL;
164 }
165
166 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
167 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
168 }
169
170 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
171 // which zeros out memory - calloc equivalent.
172 // The constructor is also used from CppVtableCloner,
173 // which doesn't zero out the memory before calling the constructor.
174 // Need to set the _java_mirror field explicitly to not hit an assert that the field
175 // should be NULL before setting it.
176 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
177 _shared_class_path_index(-1),
178 _java_mirror(NULL) {
179
180 _primary_supers[0] = this;
181 set_super_check_offset(in_bytes(primary_supers_offset()));
182 }
183
184 jint Klass::array_layout_helper(BasicType etype) {
185 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
186 // Note that T_ARRAY is not allowed here.
187 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
188 int esize = type2aelembytes(etype);
189 bool isobj = (etype == T_OBJECT);
190 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
191 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
192
193 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
194 assert(layout_helper_is_array(lh), "correct kind");
195 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
196 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
197 assert(layout_helper_header_size(lh) == hsize, "correct decode");
198 assert(layout_helper_element_type(lh) == etype, "correct decode");
199 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
200
201 return lh;
202 }
203
204 bool Klass::can_be_primary_super_slow() const {
205 if (super() == NULL)
206 return true;
207 else if (super()->super_depth() >= primary_super_limit()-1)
208 return false;
209 else
210 return true;
211 }
212
213 void Klass::initialize_supers(Klass* k, TRAPS) {
214 if (FastSuperclassLimit == 0) {
215 // None of the other machinery matters.
216 set_super(k);
217 return;
218 }
219 if (k == NULL) {
220 set_super(NULL);
221 _primary_supers[0] = this;
222 assert(super_depth() == 0, "Object must already be initialized properly");
223 } else if (k != super() || k == SystemDictionary::Object_klass()) {
224 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
225 "initialize this only once to a non-trivial value");
226 set_super(k);
227 Klass* sup = k;
228 int sup_depth = sup->super_depth();
229 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
230 if (!can_be_primary_super_slow())
231 my_depth = primary_super_limit();
232 for (juint i = 0; i < my_depth; i++) {
233 _primary_supers[i] = sup->_primary_supers[i];
234 }
235 Klass* *super_check_cell;
236 if (my_depth < primary_super_limit()) {
237 _primary_supers[my_depth] = this;
238 super_check_cell = &_primary_supers[my_depth];
239 } else {
240 // Overflow of the primary_supers array forces me to be secondary.
241 super_check_cell = &_secondary_super_cache;
242 }
243 set_super_check_offset((address)super_check_cell - (address) this);
244
245 #ifdef ASSERT
246 {
247 juint j = super_depth();
248 assert(j == my_depth, "computed accessor gets right answer");
249 Klass* t = this;
250 while (!t->can_be_primary_super()) {
251 t = t->super();
252 j = t->super_depth();
253 }
254 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
255 assert(primary_super_of_depth(j1) == NULL, "super list padding");
256 }
257 while (t != NULL) {
258 assert(primary_super_of_depth(j) == t, "super list initialization");
259 t = t->super();
260 --j;
261 }
262 assert(j == (juint)-1, "correct depth count");
263 }
264 #endif
265 }
266
267 if (secondary_supers() == NULL) {
268
269 // Now compute the list of secondary supertypes.
270 // Secondaries can occasionally be on the super chain,
271 // if the inline "_primary_supers" array overflows.
272 int extras = 0;
273 Klass* p;
274 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
275 ++extras;
276 }
277
278 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
279
280 // Compute the "real" non-extra secondaries.
281 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
282 if (secondaries == NULL) {
283 // secondary_supers set by compute_secondary_supers
284 return;
285 }
286
287 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
288
289 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
290 int i; // Scan for overflow primaries being duplicates of 2nd'arys
291
292 // This happens frequently for very deeply nested arrays: the
293 // primary superclass chain overflows into the secondary. The
294 // secondary list contains the element_klass's secondaries with
295 // an extra array dimension added. If the element_klass's
296 // secondary list already contains some primary overflows, they
297 // (with the extra level of array-ness) will collide with the
298 // normal primary superclass overflows.
299 for( i = 0; i < secondaries->length(); i++ ) {
300 if( secondaries->at(i) == p )
301 break;
302 }
303 if( i < secondaries->length() )
304 continue; // It's a dup, don't put it in
305 primaries->push(p);
306 }
307 // Combine the two arrays into a metadata object to pack the array.
308 // The primaries are added in the reverse order, then the secondaries.
309 int new_length = primaries->length() + secondaries->length();
310 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
311 class_loader_data(), new_length, CHECK);
312 int fill_p = primaries->length();
313 for (int j = 0; j < fill_p; j++) {
314 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
315 }
316 for( int j = 0; j < secondaries->length(); j++ ) {
317 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
318 }
319
320 #ifdef ASSERT
321 // We must not copy any NULL placeholders left over from bootstrap.
322 for (int j = 0; j < s2->length(); j++) {
323 assert(s2->at(j) != NULL, "correct bootstrapping order");
324 }
325 #endif
326
327 set_secondary_supers(s2);
328 }
329 }
330
331 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
332 assert(num_extra_slots == 0, "override for complex klasses");
333 set_secondary_supers(Universe::the_empty_klass_array());
334 return NULL;
335 }
336
337
338 InstanceKlass* Klass::superklass() const {
339 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
340 return _super == NULL ? NULL : InstanceKlass::cast(_super);
341 }
342
343 void Klass::set_subklass(Klass* s) {
344 assert(s != this, "sanity check");
345 _subklass = s;
346 }
347
348 void Klass::set_next_sibling(Klass* s) {
349 assert(s != this, "sanity check");
350 _next_sibling = s;
351 }
352
353 void Klass::append_to_sibling_list() {
354 debug_only(verify();)
355 // add ourselves to superklass' subklass list
356 InstanceKlass* super = superklass();
357 if (super == NULL) return; // special case: class Object
358 assert((!super->is_interface() // interfaces cannot be supers
359 && (super->superklass() == NULL || !is_interface())),
360 "an interface can only be a subklass of Object");
361 Klass* prev_first_subklass = super->subklass();
362 if (prev_first_subklass != NULL) {
363 // set our sibling to be the superklass' previous first subklass
364 set_next_sibling(prev_first_subklass);
365 }
366 // make ourselves the superklass' first subklass
367 super->set_subklass(this);
368 debug_only(verify();)
369 }
370
371 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
372 #ifdef ASSERT
373 // The class is alive iff the class loader is alive.
374 oop loader = class_loader();
375 bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
376 #endif // ASSERT
377
378 // The class is alive if it's mirror is alive (which should be marked if the
379 // loader is alive) unless it's an anoymous class.
380 bool mirror_alive = is_alive->do_object_b(java_mirror());
381 assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
382 " but not the other way around with anonymous classes");
383 return mirror_alive;
384 }
385
386 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
387 if (!ClassUnloading) {
388 return;
389 }
390
391 Klass* root = SystemDictionary::Object_klass();
392 Stack<Klass*, mtGC> stack;
393
394 stack.push(root);
395 while (!stack.is_empty()) {
396 Klass* current = stack.pop();
397
398 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
399
400 // Find and set the first alive subklass
401 Klass* sub = current->subklass();
402 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
403 #ifndef PRODUCT
404 if (log_is_enabled(Trace, class, unload)) {
405 ResourceMark rm;
406 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
407 }
408 #endif
409 sub = sub->next_sibling();
410 }
411 current->set_subklass(sub);
412 if (sub != NULL) {
413 stack.push(sub);
414 }
415
416 // Find and set the first alive sibling
417 Klass* sibling = current->next_sibling();
418 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
419 if (log_is_enabled(Trace, class, unload)) {
420 ResourceMark rm;
421 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
422 }
423 sibling = sibling->next_sibling();
424 }
425 current->set_next_sibling(sibling);
426 if (sibling != NULL) {
427 stack.push(sibling);
428 }
429
430 // Clean the implementors list and method data.
431 if (clean_alive_klasses && current->is_instance_klass()) {
432 InstanceKlass* ik = InstanceKlass::cast(current);
433 ik->clean_weak_instanceklass_links(is_alive);
434
435 // JVMTI RedefineClasses creates previous versions that are not in
436 // the class hierarchy, so process them here.
437 while ((ik = ik->previous_versions()) != NULL) {
438 ik->clean_weak_instanceklass_links(is_alive);
439 }
440 }
441 }
442 }
443
444 void Klass::klass_update_barrier_set(oop v) {
445 record_modified_oops();
446 }
447
448 // This barrier is used by G1 to remember the old oop values, so
449 // that we don't forget any objects that were live at the snapshot at
450 // the beginning. This function is only used when we write oops into Klasses.
451 void Klass::klass_update_barrier_set_pre(oop* p, oop v) {
452 #if INCLUDE_ALL_GCS
453 if (UseG1GC) {
454 oop obj = *p;
455 if (obj != NULL) {
456 G1SATBCardTableModRefBS::enqueue(obj);
457 }
458 }
459 #endif
460 }
461
462 void Klass::klass_oop_store(oop* p, oop v) {
463 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
464 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
465
466 // do the store
467 if (always_do_update_barrier) {
468 klass_oop_store((volatile oop*)p, v);
469 } else {
470 klass_update_barrier_set_pre(p, v);
471 *p = v;
472 klass_update_barrier_set(v);
473 }
474 }
475
476 void Klass::klass_oop_store(volatile oop* p, oop v) {
477 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
478 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
479
480 klass_update_barrier_set_pre((oop*)p, v); // Cast away volatile.
481 OrderAccess::release_store_ptr(p, v);
482 klass_update_barrier_set(v);
483 }
484
485 void Klass::oops_do(OopClosure* cl) {
486 cl->do_oop(&_java_mirror);
487 }
488
489 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
490 if (log_is_enabled(Trace, cds)) {
491 ResourceMark rm;
492 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
493 }
494
495 it->push(&_name);
496 it->push(&_secondary_super_cache);
497 it->push(&_secondary_supers);
498 for (int i = 0; i < _primary_super_limit; i++) {
499 it->push(&_primary_supers[i]);
500 }
501 it->push(&_super);
502 it->push(&_subklass);
503 it->push(&_next_sibling);
504 it->push(&_next_link);
505
506 vtableEntry* vt = start_of_vtable();
507 for (int i=0; i<vtable_length(); i++) {
508 it->push(vt[i].method_addr());
509 }
510 }
511
512 void Klass::remove_unshareable_info() {
513 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
514 TRACE_REMOVE_ID(this);
515 if (log_is_enabled(Trace, cds, unshareable)) {
516 ResourceMark rm;
517 log_trace(cds, unshareable)("remove: %s", external_name());
518 }
519
520 set_subklass(NULL);
521 set_next_sibling(NULL);
522 set_next_link(NULL);
523
524 // Null out class_loader_data because we don't share that yet.
525 set_class_loader_data(NULL);
526 set_is_shared();
527 }
528
529 void Klass::remove_java_mirror() {
530 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
531 if (log_is_enabled(Trace, cds, unshareable)) {
532 ResourceMark rm;
533 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
534 }
535 set_java_mirror(NULL);
536 }
537
538 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
539 assert(is_klass(), "ensure C++ vtable is restored");
540 assert(is_shared(), "must be set");
541 TRACE_RESTORE_ID(this);
542 if (log_is_enabled(Trace, cds, unshareable)) {
543 ResourceMark rm;
544 log_trace(cds, unshareable)("restore: %s", external_name());
545 }
546
547 // If an exception happened during CDS restore, some of these fields may already be
548 // set. We leave the class on the CLD list, even if incomplete so that we don't
549 // modify the CLD list outside a safepoint.
550 if (class_loader_data() == NULL) {
551 // Restore class_loader_data to the null class loader data
552 set_class_loader_data(loader_data);
553
554 // Add to null class loader list first before creating the mirror
555 // (same order as class file parsing)
556 loader_data->add_class(this);
557 }
558
559 // Recreate the class mirror.
560 // Only recreate it if not present. A previous attempt to restore may have
561 // gotten an OOM later but keep the mirror if it was created.
562 if (java_mirror() == NULL) {
563 Handle loader(THREAD, loader_data->class_loader());
564 ModuleEntry* module_entry = NULL;
565 Klass* k = this;
566 if (k->is_objArray_klass()) {
567 k = ObjArrayKlass::cast(k)->bottom_klass();
568 }
569 // Obtain klass' module.
570 if (k->is_instance_klass()) {
571 InstanceKlass* ik = (InstanceKlass*) k;
572 module_entry = ik->module();
573 } else {
574 module_entry = ModuleEntryTable::javabase_moduleEntry();
575 }
576 // Obtain java.lang.Module, if available
577 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
578 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
579 }
580 }
581
582 Klass* Klass::array_klass_or_null(int rank) {
583 EXCEPTION_MARK;
584 // No exception can be thrown by array_klass_impl when called with or_null == true.
585 // (In anycase, the execption mark will fail if it do so)
586 return array_klass_impl(true, rank, THREAD);
587 }
588
589
590 Klass* Klass::array_klass_or_null() {
591 EXCEPTION_MARK;
592 // No exception can be thrown by array_klass_impl when called with or_null == true.
593 // (In anycase, the execption mark will fail if it do so)
594 return array_klass_impl(true, THREAD);
595 }
596
597
598 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
599 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
600 return NULL;
601 }
602
603
604 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
605 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
606 return NULL;
607 }
608
609 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
610
611 // In product mode, this function doesn't have virtual function calls so
612 // there might be some performance advantage to handling InstanceKlass here.
613 const char* Klass::external_name() const {
614 if (is_instance_klass()) {
615 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
616 if (ik->is_anonymous()) {
617 intptr_t hash = 0;
618 if (ik->java_mirror() != NULL) {
619 // java_mirror might not be created yet, return 0 as hash.
620 hash = ik->java_mirror()->identity_hash();
621 }
622 char hash_buf[40];
623 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
624 size_t hash_len = strlen(hash_buf);
625
626 size_t result_len = name()->utf8_length();
627 char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
628 name()->as_klass_external_name(result, (int) result_len + 1);
629 assert(strlen(result) == result_len, "");
630 strcpy(result + result_len, hash_buf);
631 assert(strlen(result) == result_len + hash_len, "");
632 return result;
633 }
634 }
635 if (name() == NULL) return "<unknown>";
636 return name()->as_klass_external_name();
637 }
638
639
640 const char* Klass::signature_name() const {
641 if (name() == NULL) return "<unknown>";
642 return name()->as_C_string();
643 }
644
645 // Unless overridden, modifier_flags is 0.
646 jint Klass::compute_modifier_flags(TRAPS) const {
647 return 0;
648 }
649
650 int Klass::atomic_incr_biased_lock_revocation_count() {
651 return (int) Atomic::add(1, &_biased_lock_revocation_count);
652 }
653
654 // Unless overridden, jvmti_class_status has no flags set.
655 jint Klass::jvmti_class_status() const {
656 return 0;
657 }
658
659
660 // Printing
661
662 void Klass::print_on(outputStream* st) const {
663 ResourceMark rm;
664 // print title
665 st->print("%s", internal_name());
666 print_address_on(st);
667 st->cr();
668 }
669
670 void Klass::oop_print_on(oop obj, outputStream* st) {
671 ResourceMark rm;
672 // print title
673 st->print_cr("%s ", internal_name());
674 obj->print_address_on(st);
675
676 if (WizardMode) {
677 // print header
678 obj->mark()->print_on(st);
679 }
680
681 // print class
682 st->print(" - klass: ");
683 obj->klass()->print_value_on(st);
684 st->cr();
685 }
686
687 void Klass::oop_print_value_on(oop obj, outputStream* st) {
688 // print title
689 ResourceMark rm; // Cannot print in debug mode without this
690 st->print("%s", internal_name());
691 obj->print_address_on(st);
692 }
693
694 #if INCLUDE_SERVICES
695 // Size Statistics
696 void Klass::collect_statistics(KlassSizeStats *sz) const {
697 sz->_klass_bytes = sz->count(this);
698 sz->_mirror_bytes = sz->count(java_mirror());
699 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
700
701 sz->_ro_bytes += sz->_secondary_supers_bytes;
702 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
703 }
704 #endif // INCLUDE_SERVICES
705
706 // Verification
707
708 void Klass::verify_on(outputStream* st) {
709
710 // This can be expensive, but it is worth checking that this klass is actually
711 // in the CLD graph but not in production.
712 assert(Metaspace::contains((address)this), "Should be");
713
714 guarantee(this->is_klass(),"should be klass");
715
716 if (super() != NULL) {
717 guarantee(super()->is_klass(), "should be klass");
718 }
719 if (secondary_super_cache() != NULL) {
720 Klass* ko = secondary_super_cache();
721 guarantee(ko->is_klass(), "should be klass");
722 }
723 for ( uint i = 0; i < primary_super_limit(); i++ ) {
724 Klass* ko = _primary_supers[i];
725 if (ko != NULL) {
726 guarantee(ko->is_klass(), "should be klass");
727 }
728 }
729
730 if (java_mirror() != NULL) {
731 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
732 }
733 }
734
735 void Klass::oop_verify_on(oop obj, outputStream* st) {
736 guarantee(oopDesc::is_oop(obj), "should be oop");
737 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
738 }
739
740 klassVtable Klass::vtable() const {
741 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
742 }
743
744 vtableEntry* Klass::start_of_vtable() const {
745 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
746 }
747
748 Method* Klass::method_at_vtable(int index) {
749 #ifndef PRODUCT
750 assert(index >= 0, "valid vtable index");
751 if (DebugVtables) {
752 verify_vtable_index(index);
753 }
754 #endif
755 return start_of_vtable()[index].method();
756 }
757
758 ByteSize Klass::vtable_start_offset() {
759 return in_ByteSize(InstanceKlass::header_size() * wordSize);
760 }
761
762 #ifndef PRODUCT
763
764 bool Klass::verify_vtable_index(int i) {
765 int limit = vtable_length()/vtableEntry::size();
766 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
767 return true;
768 }
769
770 bool Klass::verify_itable_index(int i) {
771 assert(is_instance_klass(), "");
772 int method_count = klassItable::method_count_for_interface(this);
773 assert(i >= 0 && i < method_count, "index out of bounds");
774 return true;
775 }
776
777 #endif