1 /*
2 * Copyright (c) 1997, 2018, 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/dictionary.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "logging/log.hpp"
33 #include "memory/heapInspection.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "memory/metaspaceClosure.hpp"
36 #include "memory/metaspaceShared.hpp"
37 #include "memory/oopFactory.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/compressedOops.inline.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/oopHandle.inline.hpp"
44 #include "runtime/atomic.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/orderAccess.hpp"
47 #include "utilities/macros.hpp"
48 #include "utilities/stack.inline.hpp"
49
50 void Klass::set_java_mirror(Handle m) {
51 assert(!m.is_null(), "New mirror should never be null.");
52 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
53 _java_mirror = class_loader_data()->add_handle(m);
54 }
55
56 oop Klass::java_mirror() const {
57 return _java_mirror.resolve();
58 }
59
60 bool Klass::is_cloneable() const {
61 return _access_flags.is_cloneable_fast() ||
62 is_subtype_of(SystemDictionary::Cloneable_klass());
63 }
64
65 void Klass::set_is_cloneable() {
66 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
67 assert(is_final(), "no subclasses allowed");
68 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
69 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
70 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
71 } else {
72 _access_flags.set_is_cloneable_fast();
73 }
74 }
75
76 void Klass::set_name(Symbol* n) {
77 _name = n;
78 if (_name != NULL) _name->increment_refcount();
79 }
80
81 bool Klass::is_subclass_of(const Klass* k) const {
82 // Run up the super chain and check
83 if (this == k) return true;
84
85 Klass* t = const_cast<Klass*>(this)->super();
86
87 while (t != NULL) {
88 if (t == k) return true;
89 t = t->super();
90 }
91 return false;
92 }
93
94 bool Klass::search_secondary_supers(Klass* k) const {
95 // Put some extra logic here out-of-line, before the search proper.
96 // This cuts down the size of the inline method.
97
98 // This is necessary, since I am never in my own secondary_super list.
99 if (this == k)
100 return true;
101 // Scan the array-of-objects for a match
102 int cnt = secondary_supers()->length();
103 for (int i = 0; i < cnt; i++) {
104 if (secondary_supers()->at(i) == k) {
105 ((Klass*)this)->set_secondary_super_cache(k);
106 return true;
107 }
108 }
109 return false;
110 }
111
112 // Return self, except for abstract classes with exactly 1
113 // implementor. Then return the 1 concrete implementation.
114 Klass *Klass::up_cast_abstract() {
115 Klass *r = this;
116 while( r->is_abstract() ) { // Receiver is abstract?
117 Klass *s = r->subklass(); // Check for exactly 1 subklass
118 if( !s || s->next_sibling() ) // Oops; wrong count; give up
119 return this; // Return 'this' as a no-progress flag
120 r = s; // Loop till find concrete class
121 }
122 return r; // Return the 1 concrete class
123 }
124
125 // Find LCA in class hierarchy
126 Klass *Klass::LCA( Klass *k2 ) {
127 Klass *k1 = this;
128 while( 1 ) {
129 if( k1->is_subtype_of(k2) ) return k2;
130 if( k2->is_subtype_of(k1) ) return k1;
131 k1 = k1->super();
132 k2 = k2->super();
133 }
134 }
135
136
137 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
138 ResourceMark rm(THREAD);
139 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
140 : vmSymbols::java_lang_InstantiationException(), external_name());
141 }
142
143
144 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
145 ResourceMark rm(THREAD);
146 assert(s != NULL, "Throw NPE!");
147 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
148 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
149 }
150
151
152 void Klass::initialize(TRAPS) {
153 ShouldNotReachHere();
154 }
155
156 bool Klass::compute_is_subtype_of(Klass* k) {
157 assert(k->is_klass(), "argument must be a class");
158 return is_subclass_of(k);
159 }
160
161 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
162 #ifdef ASSERT
163 tty->print_cr("Error: find_field called on a klass oop."
164 " Likely error: reflection method does not correctly"
165 " wrap return value in a mirror object.");
166 #endif
167 ShouldNotReachHere();
168 return NULL;
169 }
170
171 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
172 #ifdef ASSERT
173 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
174 " Likely error: reflection method does not correctly"
175 " wrap return value in a mirror object.");
176 #endif
177 ShouldNotReachHere();
178 return NULL;
179 }
180
181 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
182 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
183 }
184
185 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
186 // which zeros out memory - calloc equivalent.
187 // The constructor is also used from CppVtableCloner,
188 // which doesn't zero out the memory before calling the constructor.
189 // Need to set the _java_mirror field explicitly to not hit an assert that the field
190 // should be NULL before setting it.
191 Klass::Klass(int id) : _id(id),
192 _prototype_header(markOopDesc::prototype()),
193 _shared_class_path_index(-1),
194 _java_mirror(NULL) {
195 CDS_ONLY(_shared_class_flags = 0;)
196 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
197 _primary_supers[0] = this;
198 set_super_check_offset(in_bytes(primary_supers_offset()));
199 }
200
201 jint Klass::array_layout_helper(BasicType etype) {
202 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
203 // Note that T_ARRAY is not allowed here.
204 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
205 int esize = type2aelembytes(etype);
206 bool isobj = (etype == T_OBJECT);
207 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
208 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
209
210 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
211 assert(layout_helper_is_array(lh), "correct kind");
212 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
213 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
214 assert(layout_helper_header_size(lh) == hsize, "correct decode");
215 assert(layout_helper_element_type(lh) == etype, "correct decode");
216 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
217
218 return lh;
219 }
220
221 bool Klass::can_be_primary_super_slow() const {
222 if (super() == NULL)
223 return true;
224 else if (super()->super_depth() >= primary_super_limit()-1)
225 return false;
226 else
227 return true;
228 }
229
230 void Klass::initialize_supers(Klass* k, Array<Klass*>* transitive_interfaces, TRAPS) {
231 if (FastSuperclassLimit == 0) {
232 // None of the other machinery matters.
233 set_super(k);
234 return;
235 }
236 if (k == NULL) {
237 set_super(NULL);
238 _primary_supers[0] = this;
239 assert(super_depth() == 0, "Object must already be initialized properly");
240 } else if (k != super() || k == SystemDictionary::Object_klass()) {
241 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
242 "initialize this only once to a non-trivial value");
243 set_super(k);
244 Klass* sup = k;
245 int sup_depth = sup->super_depth();
246 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
247 if (!can_be_primary_super_slow())
248 my_depth = primary_super_limit();
249 for (juint i = 0; i < my_depth; i++) {
250 _primary_supers[i] = sup->_primary_supers[i];
251 }
252 Klass* *super_check_cell;
253 if (my_depth < primary_super_limit()) {
254 _primary_supers[my_depth] = this;
255 super_check_cell = &_primary_supers[my_depth];
256 } else {
257 // Overflow of the primary_supers array forces me to be secondary.
258 super_check_cell = &_secondary_super_cache;
259 }
260 set_super_check_offset((address)super_check_cell - (address) this);
261
262 #ifdef ASSERT
263 {
264 juint j = super_depth();
265 assert(j == my_depth, "computed accessor gets right answer");
266 Klass* t = this;
267 while (!t->can_be_primary_super()) {
268 t = t->super();
269 j = t->super_depth();
270 }
271 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
272 assert(primary_super_of_depth(j1) == NULL, "super list padding");
273 }
274 while (t != NULL) {
275 assert(primary_super_of_depth(j) == t, "super list initialization");
276 t = t->super();
277 --j;
278 }
279 assert(j == (juint)-1, "correct depth count");
280 }
281 #endif
282 }
283
284 if (secondary_supers() == NULL) {
285
286 // Now compute the list of secondary supertypes.
287 // Secondaries can occasionally be on the super chain,
288 // if the inline "_primary_supers" array overflows.
289 int extras = 0;
290 Klass* p;
291 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
292 ++extras;
293 }
294
295 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
296
297 // Compute the "real" non-extra secondaries.
298 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
299 if (secondaries == NULL) {
300 // secondary_supers set by compute_secondary_supers
301 return;
302 }
303
304 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
305
306 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
307 int i; // Scan for overflow primaries being duplicates of 2nd'arys
308
309 // This happens frequently for very deeply nested arrays: the
310 // primary superclass chain overflows into the secondary. The
311 // secondary list contains the element_klass's secondaries with
312 // an extra array dimension added. If the element_klass's
313 // secondary list already contains some primary overflows, they
314 // (with the extra level of array-ness) will collide with the
315 // normal primary superclass overflows.
316 for( i = 0; i < secondaries->length(); i++ ) {
317 if( secondaries->at(i) == p )
318 break;
319 }
320 if( i < secondaries->length() )
321 continue; // It's a dup, don't put it in
322 primaries->push(p);
323 }
324 // Combine the two arrays into a metadata object to pack the array.
325 // The primaries are added in the reverse order, then the secondaries.
326 int new_length = primaries->length() + secondaries->length();
327 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
328 class_loader_data(), new_length, CHECK);
329 int fill_p = primaries->length();
330 for (int j = 0; j < fill_p; j++) {
331 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
332 }
333 for( int j = 0; j < secondaries->length(); j++ ) {
334 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
335 }
336
337 #ifdef ASSERT
338 // We must not copy any NULL placeholders left over from bootstrap.
339 for (int j = 0; j < s2->length(); j++) {
340 assert(s2->at(j) != NULL, "correct bootstrapping order");
341 }
342 #endif
343
344 set_secondary_supers(s2);
345 }
346 }
347
348 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
349 Array<Klass*>* transitive_interfaces) {
350 assert(num_extra_slots == 0, "override for complex klasses");
351 assert(transitive_interfaces == NULL, "sanity");
352 set_secondary_supers(Universe::the_empty_klass_array());
353 return NULL;
354 }
355
356
357 InstanceKlass* Klass::superklass() const {
358 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
359 return _super == NULL ? NULL : InstanceKlass::cast(_super);
360 }
361
362 void Klass::set_subklass(Klass* s) {
363 assert(s != this, "sanity check");
364 _subklass = s;
365 }
366
367 void Klass::set_next_sibling(Klass* s) {
368 assert(s != this, "sanity check");
369 _next_sibling = s;
370 }
371
372 void Klass::append_to_sibling_list() {
373 debug_only(verify();)
374 // add ourselves to superklass' subklass list
375 InstanceKlass* super = superklass();
376 if (super == NULL) return; // special case: class Object
377 assert((!super->is_interface() // interfaces cannot be supers
378 && (super->superklass() == NULL || !is_interface())),
379 "an interface can only be a subklass of Object");
380 Klass* prev_first_subklass = super->subklass();
381 if (prev_first_subklass != NULL) {
382 // set our sibling to be the superklass' previous first subklass
383 set_next_sibling(prev_first_subklass);
384 }
385 // make ourselves the superklass' first subklass
386 super->set_subklass(this);
387 debug_only(verify();)
388 }
389
390 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
391 if (!ClassUnloading || !unloading_occurred) {
392 return;
393 }
394
395 Klass* root = SystemDictionary::Object_klass();
396 Stack<Klass*, mtGC> stack;
397
398 stack.push(root);
399 while (!stack.is_empty()) {
400 Klass* current = stack.pop();
401
402 assert(current->is_loader_alive(), "just checking, this should be live");
403
404 // Find and set the first alive subklass
405 Klass* sub = current->subklass();
406 while (sub != NULL && !sub->is_loader_alive()) {
407 #ifndef PRODUCT
408 if (log_is_enabled(Trace, class, unload)) {
409 ResourceMark rm;
410 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
411 }
412 #endif
413 sub = sub->next_sibling();
414 }
415 current->set_subklass(sub);
416 if (sub != NULL) {
417 stack.push(sub);
418 }
419
420 // Find and set the first alive sibling
421 Klass* sibling = current->next_sibling();
422 while (sibling != NULL && !sibling->is_loader_alive()) {
423 if (log_is_enabled(Trace, class, unload)) {
424 ResourceMark rm;
425 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
426 }
427 sibling = sibling->next_sibling();
428 }
429 current->set_next_sibling(sibling);
430 if (sibling != NULL) {
431 stack.push(sibling);
432 }
433
434 // Clean the implementors list and method data.
435 if (clean_alive_klasses && current->is_instance_klass()) {
436 InstanceKlass* ik = InstanceKlass::cast(current);
437 ik->clean_weak_instanceklass_links();
438
439 // JVMTI RedefineClasses creates previous versions that are not in
440 // the class hierarchy, so process them here.
441 while ((ik = ik->previous_versions()) != NULL) {
442 ik->clean_weak_instanceklass_links();
443 }
444 }
445 }
446 }
447
448 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
449 if (log_is_enabled(Trace, cds)) {
450 ResourceMark rm;
451 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
452 }
453
454 it->push(&_name);
455 it->push(&_secondary_super_cache);
456 it->push(&_secondary_supers);
457 for (int i = 0; i < _primary_super_limit; i++) {
458 it->push(&_primary_supers[i]);
459 }
460 it->push(&_super);
461 it->push(&_subklass);
462 it->push(&_next_sibling);
463 it->push(&_next_link);
464
465 vtableEntry* vt = start_of_vtable();
466 for (int i=0; i<vtable_length(); i++) {
467 it->push(vt[i].method_addr());
468 }
469 }
470
471 void Klass::remove_unshareable_info() {
472 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
473 JFR_ONLY(REMOVE_ID(this);)
474 if (log_is_enabled(Trace, cds, unshareable)) {
475 ResourceMark rm;
476 log_trace(cds, unshareable)("remove: %s", external_name());
477 }
478
479 set_subklass(NULL);
480 set_next_sibling(NULL);
481 set_next_link(NULL);
482
483 // Null out class_loader_data because we don't share that yet.
484 set_class_loader_data(NULL);
485 set_is_shared();
486 }
487
488 void Klass::remove_java_mirror() {
489 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
490 if (log_is_enabled(Trace, cds, unshareable)) {
491 ResourceMark rm;
492 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
493 }
494 // Just null out the mirror. The class_loader_data() no longer exists.
495 _java_mirror = NULL;
496 }
497
498 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
499 assert(is_klass(), "ensure C++ vtable is restored");
500 assert(is_shared(), "must be set");
501 JFR_ONLY(RESTORE_ID(this);)
502 if (log_is_enabled(Trace, cds, unshareable)) {
503 ResourceMark rm;
504 log_trace(cds, unshareable)("restore: %s", external_name());
505 }
506
507 // If an exception happened during CDS restore, some of these fields may already be
508 // set. We leave the class on the CLD list, even if incomplete so that we don't
509 // modify the CLD list outside a safepoint.
510 if (class_loader_data() == NULL) {
511 // Restore class_loader_data to the null class loader data
512 set_class_loader_data(loader_data);
513
514 // Add to null class loader list first before creating the mirror
515 // (same order as class file parsing)
516 loader_data->add_class(this);
517 }
518
519 Handle loader(THREAD, loader_data->class_loader());
520 ModuleEntry* module_entry = NULL;
521 Klass* k = this;
522 if (k->is_objArray_klass()) {
523 k = ObjArrayKlass::cast(k)->bottom_klass();
524 }
525 // Obtain klass' module.
526 if (k->is_instance_klass()) {
527 InstanceKlass* ik = (InstanceKlass*) k;
528 module_entry = ik->module();
529 } else {
530 module_entry = ModuleEntryTable::javabase_moduleEntry();
531 }
532 // Obtain java.lang.Module, if available
533 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
534
535 if (this->has_raw_archived_mirror()) {
536 ResourceMark rm;
537 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
538 if (MetaspaceShared::open_archive_heap_region_mapped()) {
539 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
540 protection_domain,
541 CHECK);
542 if (present) {
543 return;
544 }
545 }
546
547 // No archived mirror data
548 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
549 _java_mirror = NULL;
550 this->clear_has_raw_archived_mirror();
551 }
552
553 // Only recreate it if not present. A previous attempt to restore may have
554 // gotten an OOM later but keep the mirror if it was created.
555 if (java_mirror() == NULL) {
556 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
557 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
558 }
559 }
560
561 #if INCLUDE_CDS_JAVA_HEAP
562 // Used at CDS dump time to access the archived mirror. No GC barrier.
563 oop Klass::archived_java_mirror_raw() {
564 assert(has_raw_archived_mirror(), "must have raw archived mirror");
565 return CompressedOops::decode(_archived_mirror);
566 }
567
568 // No GC barrier
569 void Klass::set_archived_java_mirror_raw(oop m) {
570 assert(DumpSharedSpaces, "called only during runtime");
571 _archived_mirror = CompressedOops::encode(m);
572 }
573 #endif // INCLUDE_CDS_JAVA_HEAP
574
575 Klass* Klass::array_klass_or_null(int rank) {
576 EXCEPTION_MARK;
577 // No exception can be thrown by array_klass_impl when called with or_null == true.
578 // (In anycase, the execption mark will fail if it do so)
579 return array_klass_impl(true, rank, THREAD);
580 }
581
582
583 Klass* Klass::array_klass_or_null() {
584 EXCEPTION_MARK;
585 // No exception can be thrown by array_klass_impl when called with or_null == true.
586 // (In anycase, the execption mark will fail if it do so)
587 return array_klass_impl(true, THREAD);
588 }
589
590
591 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
592 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
593 return NULL;
594 }
595
596
597 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
598 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
599 return NULL;
600 }
601
602 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
603
604 // In product mode, this function doesn't have virtual function calls so
605 // there might be some performance advantage to handling InstanceKlass here.
606 const char* Klass::external_name() const {
607 if (is_instance_klass()) {
608 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
609 if (ik->is_anonymous()) {
610 char addr_buf[20];
611 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
612 size_t addr_len = strlen(addr_buf);
613 size_t name_len = name()->utf8_length();
614 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
615 name()->as_klass_external_name(result, (int) name_len + 1);
616 assert(strlen(result) == name_len, "");
617 strcpy(result + name_len, addr_buf);
618 assert(strlen(result) == name_len + addr_len, "");
619 return result;
620 }
621 }
622 if (name() == NULL) return "<unknown>";
623 return name()->as_klass_external_name();
624 }
625
626 const char* Klass::signature_name() const {
627 if (name() == NULL) return "<unknown>";
628 return name()->as_C_string();
629 }
630
631 const char* Klass::external_kind() const {
632 if (is_interface()) return "interface";
633 if (is_abstract()) return "abstract class";
634 return "class";
635 }
636
637 // Unless overridden, modifier_flags is 0.
638 jint Klass::compute_modifier_flags(TRAPS) const {
639 return 0;
640 }
641
642 int Klass::atomic_incr_biased_lock_revocation_count() {
643 return (int) Atomic::add(1, &_biased_lock_revocation_count);
644 }
645
646 // Unless overridden, jvmti_class_status has no flags set.
647 jint Klass::jvmti_class_status() const {
648 return 0;
649 }
650
651
652 // Printing
653
654 void Klass::print_on(outputStream* st) const {
655 ResourceMark rm;
656 // print title
657 st->print("%s", internal_name());
658 print_address_on(st);
659 st->cr();
660 }
661
662 void Klass::oop_print_on(oop obj, outputStream* st) {
663 ResourceMark rm;
664 // print title
665 st->print_cr("%s ", internal_name());
666 obj->print_address_on(st);
667
668 if (WizardMode) {
669 // print header
670 obj->mark()->print_on(st);
671 }
672
673 // print class
674 st->print(" - klass: ");
675 obj->klass()->print_value_on(st);
676 st->cr();
677 }
678
679 void Klass::oop_print_value_on(oop obj, outputStream* st) {
680 // print title
681 ResourceMark rm; // Cannot print in debug mode without this
682 st->print("%s", internal_name());
683 obj->print_address_on(st);
684 }
685
686 #if INCLUDE_SERVICES
687 // Size Statistics
688 void Klass::collect_statistics(KlassSizeStats *sz) const {
689 sz->_klass_bytes = sz->count(this);
690 sz->_mirror_bytes = sz->count(java_mirror());
691 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
692
693 sz->_ro_bytes += sz->_secondary_supers_bytes;
694 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
695 }
696 #endif // INCLUDE_SERVICES
697
698 // Verification
699
700 void Klass::verify_on(outputStream* st) {
701
702 // This can be expensive, but it is worth checking that this klass is actually
703 // in the CLD graph but not in production.
704 assert(Metaspace::contains((address)this), "Should be");
705
706 guarantee(this->is_klass(),"should be klass");
707
708 if (super() != NULL) {
709 guarantee(super()->is_klass(), "should be klass");
710 }
711 if (secondary_super_cache() != NULL) {
712 Klass* ko = secondary_super_cache();
713 guarantee(ko->is_klass(), "should be klass");
714 }
715 for ( uint i = 0; i < primary_super_limit(); i++ ) {
716 Klass* ko = _primary_supers[i];
717 if (ko != NULL) {
718 guarantee(ko->is_klass(), "should be klass");
719 }
720 }
721
722 if (java_mirror() != NULL) {
723 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
724 }
725 }
726
727 void Klass::oop_verify_on(oop obj, outputStream* st) {
728 guarantee(oopDesc::is_oop(obj), "should be oop");
729 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
730 }
731
732 klassVtable Klass::vtable() const {
733 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
734 }
735
736 vtableEntry* Klass::start_of_vtable() const {
737 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
738 }
739
740 Method* Klass::method_at_vtable(int index) {
741 #ifndef PRODUCT
742 assert(index >= 0, "valid vtable index");
743 if (DebugVtables) {
744 verify_vtable_index(index);
745 }
746 #endif
747 return start_of_vtable()[index].method();
748 }
749
750 ByteSize Klass::vtable_start_offset() {
751 return in_ByteSize(InstanceKlass::header_size() * wordSize);
752 }
753
754 #ifndef PRODUCT
755
756 bool Klass::verify_vtable_index(int i) {
757 int limit = vtable_length()/vtableEntry::size();
758 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
759 return true;
760 }
761
762 bool Klass::verify_itable_index(int i) {
763 assert(is_instance_klass(), "");
764 int method_count = klassItable::method_count_for_interface(this);
765 assert(i >= 0 && i < method_count, "index out of bounds");
766 return true;
767 }
768
769 #endif // PRODUCT
770
771 // The caller of class_loader_and_module_name() (or one of its callers)
772 // must use a ResourceMark in order to correctly free the result.
773 const char* Klass::class_loader_and_module_name() const {
774 const char* delim = "/";
775 size_t delim_len = strlen(delim);
776
777 const char* fqn = external_name();
778 // Length of message to return; always include FQN
779 size_t msglen = strlen(fqn) + 1;
780
781 bool has_cl_name = false;
782 bool has_mod_name = false;
783 bool has_version = false;
784
785 // Use class loader name, if exists and not builtin
786 const char* class_loader_name = "";
787 ClassLoaderData* cld = class_loader_data();
788 assert(cld != NULL, "class_loader_data should not be NULL");
789 if (!cld->is_builtin_class_loader_data()) {
790 // If not builtin, look for name
791 oop loader = class_loader();
792 if (loader != NULL) {
793 oop class_loader_name_oop = java_lang_ClassLoader::name(loader);
794 if (class_loader_name_oop != NULL) {
795 class_loader_name = java_lang_String::as_utf8_string(class_loader_name_oop);
796 if (class_loader_name != NULL && class_loader_name[0] != '\0') {
797 has_cl_name = true;
798 msglen += strlen(class_loader_name) + delim_len;
799 }
800 }
801 }
802 }
803
804 const char* module_name = "";
805 const char* version = "";
806 const Klass* bottom_klass = is_objArray_klass() ?
807 ObjArrayKlass::cast(this)->bottom_klass() : this;
808 if (bottom_klass->is_instance_klass()) {
809 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
810 // Use module name, if exists
811 if (module->is_named()) {
812 has_mod_name = true;
813 module_name = module->name()->as_C_string();
814 msglen += strlen(module_name);
815 // Use version if exists and is not a jdk module
816 if (module->should_show_version()) {
817 has_version = true;
818 version = module->version()->as_C_string();
819 msglen += strlen(version) + 1; // +1 for "@"
820 }
821 }
822 } else {
823 // klass is an array of primitives, so its module is java.base
824 module_name = JAVA_BASE_NAME;
825 }
826
827 if (has_cl_name || has_mod_name) {
828 msglen += delim_len;
829 }
830
831 char* message = NEW_RESOURCE_ARRAY_RETURN_NULL(char, msglen);
832
833 // Just return the FQN if error in allocating string
834 if (message == NULL) {
835 return fqn;
836 }
837
838 jio_snprintf(message, msglen, "%s%s%s%s%s%s%s",
839 class_loader_name,
840 (has_cl_name) ? delim : "",
841 (has_mod_name) ? module_name : "",
842 (has_version) ? "@" : "",
843 (has_version) ? version : "",
844 (has_cl_name || has_mod_name) ? delim : "",
845 fqn);
846 return message;
847 }