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.inline.hpp"
47 #include "trace/traceMacros.hpp"
48 #include "utilities/macros.hpp"
49 #include "utilities/stack.inline.hpp"
50
51 void Klass::set_java_mirror(Handle m) {
52 assert(!m.is_null(), "New mirror should never be null.");
53 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
54 _java_mirror = class_loader_data()->add_handle(m);
55 }
56
57 oop Klass::java_mirror() const {
58 return _java_mirror.resolve();
59 }
60
61 bool Klass::is_cloneable() const {
62 return _access_flags.is_cloneable_fast() ||
63 is_subtype_of(SystemDictionary::Cloneable_klass());
64 }
65
66 void Klass::set_is_cloneable() {
67 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
68 assert(is_final(), "no subclasses allowed");
69 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
70 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
71 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
72 } else {
73 _access_flags.set_is_cloneable_fast();
74 }
75 }
76
77 void Klass::set_name(Symbol* n) {
78 _name = n;
79 if (_name != NULL) _name->increment_refcount();
80 }
81
82 bool Klass::is_subclass_of(const Klass* k) const {
83 // Run up the super chain and check
84 if (this == k) return true;
85
86 Klass* t = const_cast<Klass*>(this)->super();
87
88 while (t != NULL) {
89 if (t == k) return true;
90 t = t->super();
91 }
92 return false;
93 }
94
95 bool Klass::search_secondary_supers(Klass* k) const {
96 // Put some extra logic here out-of-line, before the search proper.
97 // This cuts down the size of the inline method.
98
99 // This is necessary, since I am never in my own secondary_super list.
100 if (this == k)
101 return true;
102 // Scan the array-of-objects for a match
103 int cnt = secondary_supers()->length();
104 for (int i = 0; i < cnt; i++) {
105 if (secondary_supers()->at(i) == k) {
106 ((Klass*)this)->set_secondary_super_cache(k);
107 return true;
108 }
109 }
110 return false;
111 }
112
113 // Return self, except for abstract classes with exactly 1
114 // implementor. Then return the 1 concrete implementation.
115 Klass *Klass::up_cast_abstract() {
116 Klass *r = this;
117 while( r->is_abstract() ) { // Receiver is abstract?
118 Klass *s = r->subklass(); // Check for exactly 1 subklass
119 if( !s || s->next_sibling() ) // Oops; wrong count; give up
120 return this; // Return 'this' as a no-progress flag
121 r = s; // Loop till find concrete class
122 }
123 return r; // Return the 1 concrete class
124 }
125
126 // Find LCA in class hierarchy
127 Klass *Klass::LCA( Klass *k2 ) {
128 Klass *k1 = this;
129 while( 1 ) {
130 if( k1->is_subtype_of(k2) ) return k2;
131 if( k2->is_subtype_of(k1) ) return k1;
132 k1 = k1->super();
133 k2 = k2->super();
134 }
135 }
136
137
138 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
139 ResourceMark rm(THREAD);
140 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
141 : vmSymbols::java_lang_InstantiationException(), external_name());
142 }
143
144
145 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
146 THROW(vmSymbols::java_lang_ArrayStoreException());
147 }
148
149
150 void Klass::initialize(TRAPS) {
151 ShouldNotReachHere();
152 }
153
154 bool Klass::compute_is_subtype_of(Klass* k) {
155 assert(k->is_klass(), "argument must be a class");
156 return is_subclass_of(k);
157 }
158
159 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
160 #ifdef ASSERT
161 tty->print_cr("Error: find_field called on a klass oop."
162 " Likely error: reflection method does not correctly"
163 " wrap return value in a mirror object.");
164 #endif
165 ShouldNotReachHere();
166 return NULL;
167 }
168
169 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
170 OverpassLookupMode overpass_mode,
171 PrivateLookupMode private_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() : _prototype_header(markOopDesc::prototype()),
192 _shared_class_path_index(-1),
193 _java_mirror(NULL) {
194 CDS_ONLY(_shared_class_flags = 0;)
195 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
196 _primary_supers[0] = this;
197 set_super_check_offset(in_bytes(primary_supers_offset()));
198 }
199
200 jint Klass::array_layout_helper(BasicType etype) {
201 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
202 // Note that T_ARRAY is not allowed here.
203 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
204 int esize = type2aelembytes(etype);
205 bool isobj = (etype == T_OBJECT);
206 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
207 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
208
209 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
210 assert(layout_helper_is_array(lh), "correct kind");
211 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
212 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
213 assert(layout_helper_header_size(lh) == hsize, "correct decode");
214 assert(layout_helper_element_type(lh) == etype, "correct decode");
215 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
216
217 return lh;
218 }
219
220 bool Klass::can_be_primary_super_slow() const {
221 if (super() == NULL)
222 return true;
223 else if (super()->super_depth() >= primary_super_limit()-1)
224 return false;
225 else
226 return true;
227 }
228
229 void Klass::initialize_supers(Klass* k, Array<Klass*>* transitive_interfaces, TRAPS) {
230 if (FastSuperclassLimit == 0) {
231 // None of the other machinery matters.
232 set_super(k);
233 return;
234 }
235 if (k == NULL) {
236 set_super(NULL);
237 _primary_supers[0] = this;
238 assert(super_depth() == 0, "Object must already be initialized properly");
239 } else if (k != super() || k == SystemDictionary::Object_klass()) {
240 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
241 "initialize this only once to a non-trivial value");
242 set_super(k);
243 Klass* sup = k;
244 int sup_depth = sup->super_depth();
245 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
246 if (!can_be_primary_super_slow())
247 my_depth = primary_super_limit();
248 for (juint i = 0; i < my_depth; i++) {
249 _primary_supers[i] = sup->_primary_supers[i];
250 }
251 Klass* *super_check_cell;
252 if (my_depth < primary_super_limit()) {
253 _primary_supers[my_depth] = this;
254 super_check_cell = &_primary_supers[my_depth];
255 } else {
256 // Overflow of the primary_supers array forces me to be secondary.
257 super_check_cell = &_secondary_super_cache;
258 }
259 set_super_check_offset((address)super_check_cell - (address) this);
260
261 #ifdef ASSERT
262 {
263 juint j = super_depth();
264 assert(j == my_depth, "computed accessor gets right answer");
265 Klass* t = this;
266 while (!t->can_be_primary_super()) {
267 t = t->super();
268 j = t->super_depth();
269 }
270 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
271 assert(primary_super_of_depth(j1) == NULL, "super list padding");
272 }
273 while (t != NULL) {
274 assert(primary_super_of_depth(j) == t, "super list initialization");
275 t = t->super();
276 --j;
277 }
278 assert(j == (juint)-1, "correct depth count");
279 }
280 #endif
281 }
282
283 if (secondary_supers() == NULL) {
284
285 // Now compute the list of secondary supertypes.
286 // Secondaries can occasionally be on the super chain,
287 // if the inline "_primary_supers" array overflows.
288 int extras = 0;
289 Klass* p;
290 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
291 ++extras;
292 }
293
294 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
295
296 // Compute the "real" non-extra secondaries.
297 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
298 if (secondaries == NULL) {
299 // secondary_supers set by compute_secondary_supers
300 return;
301 }
302
303 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
304
305 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
306 int i; // Scan for overflow primaries being duplicates of 2nd'arys
307
308 // This happens frequently for very deeply nested arrays: the
309 // primary superclass chain overflows into the secondary. The
310 // secondary list contains the element_klass's secondaries with
311 // an extra array dimension added. If the element_klass's
312 // secondary list already contains some primary overflows, they
313 // (with the extra level of array-ness) will collide with the
314 // normal primary superclass overflows.
315 for( i = 0; i < secondaries->length(); i++ ) {
316 if( secondaries->at(i) == p )
317 break;
318 }
319 if( i < secondaries->length() )
320 continue; // It's a dup, don't put it in
321 primaries->push(p);
322 }
323 // Combine the two arrays into a metadata object to pack the array.
324 // The primaries are added in the reverse order, then the secondaries.
325 int new_length = primaries->length() + secondaries->length();
326 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
327 class_loader_data(), new_length, CHECK);
328 int fill_p = primaries->length();
329 for (int j = 0; j < fill_p; j++) {
330 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
331 }
332 for( int j = 0; j < secondaries->length(); j++ ) {
333 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
334 }
335
336 #ifdef ASSERT
337 // We must not copy any NULL placeholders left over from bootstrap.
338 for (int j = 0; j < s2->length(); j++) {
339 assert(s2->at(j) != NULL, "correct bootstrapping order");
340 }
341 #endif
342
343 set_secondary_supers(s2);
344 }
345 }
346
347 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
348 Array<Klass*>* transitive_interfaces) {
349 assert(num_extra_slots == 0, "override for complex klasses");
350 assert(transitive_interfaces == NULL, "sanity");
351 set_secondary_supers(Universe::the_empty_klass_array());
352 return NULL;
353 }
354
355
356 InstanceKlass* Klass::superklass() const {
357 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
358 return _super == NULL ? NULL : InstanceKlass::cast(_super);
359 }
360
361 void Klass::set_subklass(Klass* s) {
362 assert(s != this, "sanity check");
363 _subklass = s;
364 }
365
366 void Klass::set_next_sibling(Klass* s) {
367 assert(s != this, "sanity check");
368 _next_sibling = s;
369 }
370
371 void Klass::append_to_sibling_list() {
372 debug_only(verify();)
373 // add ourselves to superklass' subklass list
374 InstanceKlass* super = superklass();
375 if (super == NULL) return; // special case: class Object
376 assert((!super->is_interface() // interfaces cannot be supers
377 && (super->superklass() == NULL || !is_interface())),
378 "an interface can only be a subklass of Object");
379 Klass* prev_first_subklass = super->subklass();
380 if (prev_first_subklass != NULL) {
381 // set our sibling to be the superklass' previous first subklass
382 set_next_sibling(prev_first_subklass);
383 }
384 // make ourselves the superklass' first subklass
385 super->set_subklass(this);
386 debug_only(verify();)
387 }
388
389 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
390 if (!ClassUnloading || !unloading_occurred) {
391 return;
392 }
393
394 Klass* root = SystemDictionary::Object_klass();
395 Stack<Klass*, mtGC> stack;
396
397 stack.push(root);
398 while (!stack.is_empty()) {
399 Klass* current = stack.pop();
400
401 assert(current->is_loader_alive(), "just checking, this should be live");
402
403 // Find and set the first alive subklass
404 Klass* sub = current->subklass();
405 while (sub != NULL && !sub->is_loader_alive()) {
406 #ifndef PRODUCT
407 if (log_is_enabled(Trace, class, unload)) {
408 ResourceMark rm;
409 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
410 }
411 #endif
412 sub = sub->next_sibling();
413 }
414 current->set_subklass(sub);
415 if (sub != NULL) {
416 stack.push(sub);
417 }
418
419 // Find and set the first alive sibling
420 Klass* sibling = current->next_sibling();
421 while (sibling != NULL && !sibling->is_loader_alive()) {
422 if (log_is_enabled(Trace, class, unload)) {
423 ResourceMark rm;
424 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
425 }
426 sibling = sibling->next_sibling();
427 }
428 current->set_next_sibling(sibling);
429 if (sibling != NULL) {
430 stack.push(sibling);
431 }
432
433 // Clean the implementors list and method data.
434 if (clean_alive_klasses && current->is_instance_klass()) {
435 InstanceKlass* ik = InstanceKlass::cast(current);
436 ik->clean_weak_instanceklass_links();
437
438 // JVMTI RedefineClasses creates previous versions that are not in
439 // the class hierarchy, so process them here.
440 while ((ik = ik->previous_versions()) != NULL) {
441 ik->clean_weak_instanceklass_links();
442 }
443 }
444 }
445 }
446
447 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
448 if (log_is_enabled(Trace, cds)) {
449 ResourceMark rm;
450 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
451 }
452
453 it->push(&_name);
454 it->push(&_secondary_super_cache);
455 it->push(&_secondary_supers);
456 for (int i = 0; i < _primary_super_limit; i++) {
457 it->push(&_primary_supers[i]);
458 }
459 it->push(&_super);
460 it->push(&_subklass);
461 it->push(&_next_sibling);
462 it->push(&_next_link);
463
464 vtableEntry* vt = start_of_vtable();
465 for (int i=0; i<vtable_length(); i++) {
466 it->push(vt[i].method_addr());
467 }
468 }
469
470 void Klass::remove_unshareable_info() {
471 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
472 TRACE_REMOVE_ID(this);
473 if (log_is_enabled(Trace, cds, unshareable)) {
474 ResourceMark rm;
475 log_trace(cds, unshareable)("remove: %s", external_name());
476 }
477
478 set_subklass(NULL);
479 set_next_sibling(NULL);
480 set_next_link(NULL);
481
482 // Null out class_loader_data because we don't share that yet.
483 set_class_loader_data(NULL);
484 set_is_shared();
485 }
486
487 void Klass::remove_java_mirror() {
488 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
489 if (log_is_enabled(Trace, cds, unshareable)) {
490 ResourceMark rm;
491 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
492 }
493 // Just null out the mirror. The class_loader_data() no longer exists.
494 _java_mirror = NULL;
495 }
496
497 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
498 assert(is_klass(), "ensure C++ vtable is restored");
499 assert(is_shared(), "must be set");
500 TRACE_RESTORE_ID(this);
501 if (log_is_enabled(Trace, cds, unshareable)) {
502 ResourceMark rm;
503 log_trace(cds, unshareable)("restore: %s", external_name());
504 }
505
506 // If an exception happened during CDS restore, some of these fields may already be
507 // set. We leave the class on the CLD list, even if incomplete so that we don't
508 // modify the CLD list outside a safepoint.
509 if (class_loader_data() == NULL) {
510 // Restore class_loader_data to the null class loader data
511 set_class_loader_data(loader_data);
512
513 // Add to null class loader list first before creating the mirror
514 // (same order as class file parsing)
515 loader_data->add_class(this);
516 }
517
518 Handle loader(THREAD, loader_data->class_loader());
519 ModuleEntry* module_entry = NULL;
520 Klass* k = this;
521 if (k->is_objArray_klass()) {
522 k = ObjArrayKlass::cast(k)->bottom_klass();
523 }
524 // Obtain klass' module.
525 if (k->is_instance_klass()) {
526 InstanceKlass* ik = (InstanceKlass*) k;
527 module_entry = ik->module();
528 } else {
529 module_entry = ModuleEntryTable::javabase_moduleEntry();
530 }
531 // Obtain java.lang.Module, if available
532 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
533
534 if (this->has_raw_archived_mirror()) {
535 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
536 if (MetaspaceShared::open_archive_heap_region_mapped()) {
537 oop m = archived_java_mirror();
538 log_debug(cds, mirror)("Archived mirror is: " PTR_FORMAT, p2i(m));
539 if (m != NULL) {
540 // mirror is archived, restore
541 assert(MetaspaceShared::is_archive_object(m), "must be archived mirror object");
542 Handle m_h(THREAD, m);
543 java_lang_Class::restore_archived_mirror(this, m_h, loader, module_handle, protection_domain, CHECK);
544 return;
545 }
546 }
547
548 // No archived mirror data
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(DumpSharedSpaces, "called only during runtime");
565 assert(has_raw_archived_mirror(), "must have raw archived mirror");
566 return CompressedOops::decode(_archived_mirror);
567 }
568
569 // Used at CDS runtime to get the archived mirror from shared class. Uses GC barrier.
570 oop Klass::archived_java_mirror() {
571 assert(UseSharedSpaces, "UseSharedSpaces expected.");
572 assert(has_raw_archived_mirror(), "must have raw archived mirror");
573 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_mirror);
574 }
575
576 // No GC barrier
577 void Klass::set_archived_java_mirror_raw(oop m) {
578 assert(DumpSharedSpaces, "called only during runtime");
579 _archived_mirror = CompressedOops::encode(m);
580 }
581 #endif // INCLUDE_CDS_JAVA_HEAP
582
583 Klass* Klass::array_klass_or_null(int rank) {
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, rank, THREAD);
588 }
589
590
591 Klass* Klass::array_klass_or_null() {
592 EXCEPTION_MARK;
593 // No exception can be thrown by array_klass_impl when called with or_null == true.
594 // (In anycase, the execption mark will fail if it do so)
595 return array_klass_impl(true, THREAD);
596 }
597
598
599 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
600 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
601 return NULL;
602 }
603
604
605 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
606 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
607 return NULL;
608 }
609
610 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
611
612 // In product mode, this function doesn't have virtual function calls so
613 // there might be some performance advantage to handling InstanceKlass here.
614 const char* Klass::external_name() const {
615 if (is_instance_klass()) {
616 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
617 if (ik->is_anonymous()) {
618 char addr_buf[20];
619 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
620 size_t addr_len = strlen(addr_buf);
621 size_t name_len = name()->utf8_length();
622 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
623 name()->as_klass_external_name(result, (int) name_len + 1);
624 assert(strlen(result) == name_len, "");
625 strcpy(result + name_len, addr_buf);
626 assert(strlen(result) == name_len + addr_len, "");
627 return result;
628 }
629 }
630 if (name() == NULL) return "<unknown>";
631 return name()->as_klass_external_name();
632 }
633
634 const char* Klass::signature_name() const {
635 if (name() == NULL) return "<unknown>";
636 return name()->as_C_string();
637 }
638
639 const char* Klass::external_kind() const {
640 if (is_interface()) return "interface";
641 if (is_abstract()) return "abstract class";
642 return "class";
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 // PRODUCT
778
779 // The caller of class_loader_and_module_name() (or one of its callers)
780 // must use a ResourceMark in order to correctly free the result.
781 const char* Klass::class_loader_and_module_name() const {
782 const char* delim = "/";
783 size_t delim_len = strlen(delim);
784
785 const char* fqn = external_name();
786 // Length of message to return; always include FQN
787 size_t msglen = strlen(fqn) + 1;
788
789 bool has_cl_name = false;
790 bool has_mod_name = false;
791 bool has_version = false;
792
793 // Use class loader name, if exists and not builtin
794 const char* class_loader_name = "";
795 ClassLoaderData* cld = class_loader_data();
796 assert(cld != NULL, "class_loader_data should not be NULL");
797 if (!cld->is_builtin_class_loader_data()) {
798 // If not builtin, look for name
799 oop loader = class_loader();
800 if (loader != NULL) {
801 oop class_loader_name_oop = java_lang_ClassLoader::name(loader);
802 if (class_loader_name_oop != NULL) {
803 class_loader_name = java_lang_String::as_utf8_string(class_loader_name_oop);
804 if (class_loader_name != NULL && class_loader_name[0] != '\0') {
805 has_cl_name = true;
806 msglen += strlen(class_loader_name) + delim_len;
807 }
808 }
809 }
810 }
811
812 const char* module_name = "";
813 const char* version = "";
814 const Klass* bottom_klass = is_objArray_klass() ?
815 ObjArrayKlass::cast(this)->bottom_klass() : this;
816 if (bottom_klass->is_instance_klass()) {
817 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
818 // Use module name, if exists
819 if (module->is_named()) {
820 has_mod_name = true;
821 module_name = module->name()->as_C_string();
822 msglen += strlen(module_name);
823 // Use version if exists and is not a jdk module
824 if (module->is_non_jdk_module() && module->version() != NULL) {
825 has_version = true;
826 version = module->version()->as_C_string();
827 msglen += strlen("@") + strlen(version);
828 }
829 }
830 } else {
831 // klass is an array of primitives, so its module is java.base
832 module_name = JAVA_BASE_NAME;
833 }
834
835 if (has_cl_name || has_mod_name) {
836 msglen += delim_len;
837 }
838
839 char* message = NEW_RESOURCE_ARRAY_RETURN_NULL(char, msglen);
840
841 // Just return the FQN if error in allocating string
842 if (message == NULL) {
843 return fqn;
844 }
845
846 jio_snprintf(message, msglen, "%s%s%s%s%s%s%s",
847 class_loader_name,
848 (has_cl_name) ? delim : "",
849 (has_mod_name) ? module_name : "",
850 (has_version) ? "@" : "",
851 (has_version) ? version : "",
852 (has_cl_name || has_mod_name) ? delim : "",
853 fqn);
854 return message;
855 }