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, OverpassLookupMode overpass_mode) const {
170 #ifdef ASSERT
171 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
172 " Likely error: reflection method does not correctly"
173 " wrap return value in a mirror object.");
174 #endif
175 ShouldNotReachHere();
176 return NULL;
177 }
178
179 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
180 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
181 }
182
183 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
184 // which zeros out memory - calloc equivalent.
185 // The constructor is also used from CppVtableCloner,
186 // which doesn't zero out the memory before calling the constructor.
187 // Need to set the _java_mirror field explicitly to not hit an assert that the field
188 // should be NULL before setting it.
189 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
190 _shared_class_path_index(-1),
191 _java_mirror(NULL) {
192 CDS_ONLY(_shared_class_flags = 0;)
193 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
194 _primary_supers[0] = this;
195 set_super_check_offset(in_bytes(primary_supers_offset()));
196 }
197
198 jint Klass::array_layout_helper(BasicType etype) {
199 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
200 // Note that T_ARRAY is not allowed here.
201 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
202 int esize = type2aelembytes(etype);
203 bool isobj = (etype == T_OBJECT);
204 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
205 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
206
207 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
208 assert(layout_helper_is_array(lh), "correct kind");
209 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
210 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
211 assert(layout_helper_header_size(lh) == hsize, "correct decode");
212 assert(layout_helper_element_type(lh) == etype, "correct decode");
213 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
214
215 return lh;
216 }
217
218 bool Klass::can_be_primary_super_slow() const {
219 if (super() == NULL)
220 return true;
221 else if (super()->super_depth() >= primary_super_limit()-1)
222 return false;
223 else
224 return true;
225 }
226
227 void Klass::initialize_supers(Klass* k, Array<Klass*>* transitive_interfaces, TRAPS) {
228 if (FastSuperclassLimit == 0) {
229 // None of the other machinery matters.
230 set_super(k);
231 return;
232 }
233 if (k == NULL) {
234 set_super(NULL);
235 _primary_supers[0] = this;
236 assert(super_depth() == 0, "Object must already be initialized properly");
237 } else if (k != super() || k == SystemDictionary::Object_klass()) {
238 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
239 "initialize this only once to a non-trivial value");
240 set_super(k);
241 Klass* sup = k;
242 int sup_depth = sup->super_depth();
243 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
244 if (!can_be_primary_super_slow())
245 my_depth = primary_super_limit();
246 for (juint i = 0; i < my_depth; i++) {
247 _primary_supers[i] = sup->_primary_supers[i];
248 }
249 Klass* *super_check_cell;
250 if (my_depth < primary_super_limit()) {
251 _primary_supers[my_depth] = this;
252 super_check_cell = &_primary_supers[my_depth];
253 } else {
254 // Overflow of the primary_supers array forces me to be secondary.
255 super_check_cell = &_secondary_super_cache;
256 }
257 set_super_check_offset((address)super_check_cell - (address) this);
258
259 #ifdef ASSERT
260 {
261 juint j = super_depth();
262 assert(j == my_depth, "computed accessor gets right answer");
263 Klass* t = this;
264 while (!t->can_be_primary_super()) {
265 t = t->super();
266 j = t->super_depth();
267 }
268 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
269 assert(primary_super_of_depth(j1) == NULL, "super list padding");
270 }
271 while (t != NULL) {
272 assert(primary_super_of_depth(j) == t, "super list initialization");
273 t = t->super();
274 --j;
275 }
276 assert(j == (juint)-1, "correct depth count");
277 }
278 #endif
279 }
280
281 if (secondary_supers() == NULL) {
282
283 // Now compute the list of secondary supertypes.
284 // Secondaries can occasionally be on the super chain,
285 // if the inline "_primary_supers" array overflows.
286 int extras = 0;
287 Klass* p;
288 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
289 ++extras;
290 }
291
292 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
293
294 // Compute the "real" non-extra secondaries.
295 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
296 if (secondaries == NULL) {
297 // secondary_supers set by compute_secondary_supers
298 return;
299 }
300
301 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
302
303 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
304 int i; // Scan for overflow primaries being duplicates of 2nd'arys
305
306 // This happens frequently for very deeply nested arrays: the
307 // primary superclass chain overflows into the secondary. The
308 // secondary list contains the element_klass's secondaries with
309 // an extra array dimension added. If the element_klass's
310 // secondary list already contains some primary overflows, they
311 // (with the extra level of array-ness) will collide with the
312 // normal primary superclass overflows.
313 for( i = 0; i < secondaries->length(); i++ ) {
314 if( secondaries->at(i) == p )
315 break;
316 }
317 if( i < secondaries->length() )
318 continue; // It's a dup, don't put it in
319 primaries->push(p);
320 }
321 // Combine the two arrays into a metadata object to pack the array.
322 // The primaries are added in the reverse order, then the secondaries.
323 int new_length = primaries->length() + secondaries->length();
324 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
325 class_loader_data(), new_length, CHECK);
326 int fill_p = primaries->length();
327 for (int j = 0; j < fill_p; j++) {
328 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
329 }
330 for( int j = 0; j < secondaries->length(); j++ ) {
331 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
332 }
333
334 #ifdef ASSERT
335 // We must not copy any NULL placeholders left over from bootstrap.
336 for (int j = 0; j < s2->length(); j++) {
337 assert(s2->at(j) != NULL, "correct bootstrapping order");
338 }
339 #endif
340
341 set_secondary_supers(s2);
342 }
343 }
344
345 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
346 Array<Klass*>* transitive_interfaces) {
347 assert(num_extra_slots == 0, "override for complex klasses");
348 assert(transitive_interfaces == NULL, "sanity");
349 set_secondary_supers(Universe::the_empty_klass_array());
350 return NULL;
351 }
352
353
354 InstanceKlass* Klass::superklass() const {
355 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
356 return _super == NULL ? NULL : InstanceKlass::cast(_super);
357 }
358
359 void Klass::set_subklass(Klass* s) {
360 assert(s != this, "sanity check");
361 _subklass = s;
362 }
363
364 void Klass::set_next_sibling(Klass* s) {
365 assert(s != this, "sanity check");
366 _next_sibling = s;
367 }
368
369 void Klass::append_to_sibling_list() {
370 debug_only(verify();)
371 // add ourselves to superklass' subklass list
372 InstanceKlass* super = superklass();
373 if (super == NULL) return; // special case: class Object
374 assert((!super->is_interface() // interfaces cannot be supers
375 && (super->superklass() == NULL || !is_interface())),
376 "an interface can only be a subklass of Object");
377 Klass* prev_first_subklass = super->subklass();
378 if (prev_first_subklass != NULL) {
379 // set our sibling to be the superklass' previous first subklass
380 set_next_sibling(prev_first_subklass);
381 }
382 // make ourselves the superklass' first subklass
383 super->set_subklass(this);
384 debug_only(verify();)
385 }
386
387 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
388 if (!ClassUnloading || !unloading_occurred) {
389 return;
390 }
391
392 Klass* root = SystemDictionary::Object_klass();
393 Stack<Klass*, mtGC> stack;
394
395 stack.push(root);
396 while (!stack.is_empty()) {
397 Klass* current = stack.pop();
398
399 assert(current->is_loader_alive(), "just checking, this should be live");
400
401 // Find and set the first alive subklass
402 Klass* sub = current->subklass();
403 while (sub != NULL && !sub->is_loader_alive()) {
404 #ifndef PRODUCT
405 if (log_is_enabled(Trace, class, unload)) {
406 ResourceMark rm;
407 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
408 }
409 #endif
410 sub = sub->next_sibling();
411 }
412 current->set_subklass(sub);
413 if (sub != NULL) {
414 stack.push(sub);
415 }
416
417 // Find and set the first alive sibling
418 Klass* sibling = current->next_sibling();
419 while (sibling != NULL && !sibling->is_loader_alive()) {
420 if (log_is_enabled(Trace, class, unload)) {
421 ResourceMark rm;
422 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
423 }
424 sibling = sibling->next_sibling();
425 }
426 current->set_next_sibling(sibling);
427 if (sibling != NULL) {
428 stack.push(sibling);
429 }
430
431 // Clean the implementors list and method data.
432 if (clean_alive_klasses && current->is_instance_klass()) {
433 InstanceKlass* ik = InstanceKlass::cast(current);
434 ik->clean_weak_instanceklass_links();
435
436 // JVMTI RedefineClasses creates previous versions that are not in
437 // the class hierarchy, so process them here.
438 while ((ik = ik->previous_versions()) != NULL) {
439 ik->clean_weak_instanceklass_links();
440 }
441 }
442 }
443 }
444
445 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
446 if (log_is_enabled(Trace, cds)) {
447 ResourceMark rm;
448 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
449 }
450
451 it->push(&_name);
452 it->push(&_secondary_super_cache);
453 it->push(&_secondary_supers);
454 for (int i = 0; i < _primary_super_limit; i++) {
455 it->push(&_primary_supers[i]);
456 }
457 it->push(&_super);
458 it->push(&_subklass);
459 it->push(&_next_sibling);
460 it->push(&_next_link);
461
462 vtableEntry* vt = start_of_vtable();
463 for (int i=0; i<vtable_length(); i++) {
464 it->push(vt[i].method_addr());
465 }
466 }
467
468 void Klass::remove_unshareable_info() {
469 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
470 TRACE_REMOVE_ID(this);
471 if (log_is_enabled(Trace, cds, unshareable)) {
472 ResourceMark rm;
473 log_trace(cds, unshareable)("remove: %s", external_name());
474 }
475
476 set_subklass(NULL);
477 set_next_sibling(NULL);
478 set_next_link(NULL);
479
480 // Null out class_loader_data because we don't share that yet.
481 set_class_loader_data(NULL);
482 set_is_shared();
483 }
484
485 void Klass::remove_java_mirror() {
486 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
487 if (log_is_enabled(Trace, cds, unshareable)) {
488 ResourceMark rm;
489 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
490 }
491 // Just null out the mirror. The class_loader_data() no longer exists.
492 _java_mirror = NULL;
493 }
494
495 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
496 assert(is_klass(), "ensure C++ vtable is restored");
497 assert(is_shared(), "must be set");
498 TRACE_RESTORE_ID(this);
499 if (log_is_enabled(Trace, cds, unshareable)) {
500 ResourceMark rm;
501 log_trace(cds, unshareable)("restore: %s", external_name());
502 }
503
504 // If an exception happened during CDS restore, some of these fields may already be
505 // set. We leave the class on the CLD list, even if incomplete so that we don't
506 // modify the CLD list outside a safepoint.
507 if (class_loader_data() == NULL) {
508 // Restore class_loader_data to the null class loader data
509 set_class_loader_data(loader_data);
510
511 // Add to null class loader list first before creating the mirror
512 // (same order as class file parsing)
513 loader_data->add_class(this);
514 }
515
516 Handle loader(THREAD, loader_data->class_loader());
517 ModuleEntry* module_entry = NULL;
518 Klass* k = this;
519 if (k->is_objArray_klass()) {
520 k = ObjArrayKlass::cast(k)->bottom_klass();
521 }
522 // Obtain klass' module.
523 if (k->is_instance_klass()) {
524 InstanceKlass* ik = (InstanceKlass*) k;
525 module_entry = ik->module();
526 } else {
527 module_entry = ModuleEntryTable::javabase_moduleEntry();
528 }
529 // Obtain java.lang.Module, if available
530 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
531
532 if (this->has_raw_archived_mirror()) {
533 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
534 if (MetaspaceShared::open_archive_heap_region_mapped()) {
535 oop m = archived_java_mirror();
536 log_debug(cds, mirror)("Archived mirror is: " PTR_FORMAT, p2i(m));
537 if (m != NULL) {
538 // mirror is archived, restore
539 assert(MetaspaceShared::is_archive_object(m), "must be archived mirror object");
540 Handle m_h(THREAD, m);
541 java_lang_Class::restore_archived_mirror(this, m_h, loader, module_handle, protection_domain, CHECK);
542 return;
543 }
544 }
545
546 // No archived mirror data
547 _java_mirror = NULL;
548 this->clear_has_raw_archived_mirror();
549 }
550
551 // Only recreate it if not present. A previous attempt to restore may have
552 // gotten an OOM later but keep the mirror if it was created.
553 if (java_mirror() == NULL) {
554 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
555 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
556 }
557 }
558
559 #if INCLUDE_CDS_JAVA_HEAP
560 // Used at CDS dump time to access the archived mirror. No GC barrier.
561 oop Klass::archived_java_mirror_raw() {
562 assert(DumpSharedSpaces, "called only during runtime");
563 assert(has_raw_archived_mirror(), "must have raw archived mirror");
564 return CompressedOops::decode(_archived_mirror);
565 }
566
567 // Used at CDS runtime to get the archived mirror from shared class. Uses GC barrier.
568 oop Klass::archived_java_mirror() {
569 assert(UseSharedSpaces, "UseSharedSpaces expected.");
570 assert(has_raw_archived_mirror(), "must have raw archived mirror");
571 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_mirror);
572 }
573
574 // No GC barrier
575 void Klass::set_archived_java_mirror_raw(oop m) {
576 assert(DumpSharedSpaces, "called only during runtime");
577 _archived_mirror = CompressedOops::encode(m);
578 }
579 #endif // INCLUDE_CDS_JAVA_HEAP
580
581 Klass* Klass::array_klass_or_null(int rank) {
582 EXCEPTION_MARK;
583 // No exception can be thrown by array_klass_impl when called with or_null == true.
584 // (In anycase, the execption mark will fail if it do so)
585 return array_klass_impl(true, rank, THREAD);
586 }
587
588
589 Klass* Klass::array_klass_or_null() {
590 EXCEPTION_MARK;
591 // No exception can be thrown by array_klass_impl when called with or_null == true.
592 // (In anycase, the execption mark will fail if it do so)
593 return array_klass_impl(true, THREAD);
594 }
595
596
597 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
598 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
599 return NULL;
600 }
601
602
603 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
604 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
605 return NULL;
606 }
607
608 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
609
610 // In product mode, this function doesn't have virtual function calls so
611 // there might be some performance advantage to handling InstanceKlass here.
612 const char* Klass::external_name() const {
613 if (is_instance_klass()) {
614 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
615 if (ik->is_anonymous()) {
616 char addr_buf[20];
617 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
618 size_t addr_len = strlen(addr_buf);
619 size_t name_len = name()->utf8_length();
620 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
621 name()->as_klass_external_name(result, (int) name_len + 1);
622 assert(strlen(result) == name_len, "");
623 strcpy(result + name_len, addr_buf);
624 assert(strlen(result) == name_len + addr_len, "");
625 return result;
626 }
627 }
628 if (name() == NULL) return "<unknown>";
629 return name()->as_klass_external_name();
630 }
631
632 const char* Klass::signature_name() const {
633 if (name() == NULL) return "<unknown>";
634 return name()->as_C_string();
635 }
636
637 const char* Klass::external_kind() const {
638 if (is_interface()) return "interface";
639 if (is_abstract()) return "abstract class";
640 return "class";
641 }
642
643 // Unless overridden, modifier_flags is 0.
644 jint Klass::compute_modifier_flags(TRAPS) const {
645 return 0;
646 }
647
648 int Klass::atomic_incr_biased_lock_revocation_count() {
649 return (int) Atomic::add(1, &_biased_lock_revocation_count);
650 }
651
652 // Unless overridden, jvmti_class_status has no flags set.
653 jint Klass::jvmti_class_status() const {
654 return 0;
655 }
656
657
658 // Printing
659
660 void Klass::print_on(outputStream* st) const {
661 ResourceMark rm;
662 // print title
663 st->print("%s", internal_name());
664 print_address_on(st);
665 st->cr();
666 }
667
668 void Klass::oop_print_on(oop obj, outputStream* st) {
669 ResourceMark rm;
670 // print title
671 st->print_cr("%s ", internal_name());
672 obj->print_address_on(st);
673
674 if (WizardMode) {
675 // print header
676 obj->mark()->print_on(st);
677 }
678
679 // print class
680 st->print(" - klass: ");
681 obj->klass()->print_value_on(st);
682 st->cr();
683 }
684
685 void Klass::oop_print_value_on(oop obj, outputStream* st) {
686 // print title
687 ResourceMark rm; // Cannot print in debug mode without this
688 st->print("%s", internal_name());
689 obj->print_address_on(st);
690 }
691
692 #if INCLUDE_SERVICES
693 // Size Statistics
694 void Klass::collect_statistics(KlassSizeStats *sz) const {
695 sz->_klass_bytes = sz->count(this);
696 sz->_mirror_bytes = sz->count(java_mirror());
697 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
698
699 sz->_ro_bytes += sz->_secondary_supers_bytes;
700 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
701 }
702 #endif // INCLUDE_SERVICES
703
704 // Verification
705
706 void Klass::verify_on(outputStream* st) {
707
708 // This can be expensive, but it is worth checking that this klass is actually
709 // in the CLD graph but not in production.
710 assert(Metaspace::contains((address)this), "Should be");
711
712 guarantee(this->is_klass(),"should be klass");
713
714 if (super() != NULL) {
715 guarantee(super()->is_klass(), "should be klass");
716 }
717 if (secondary_super_cache() != NULL) {
718 Klass* ko = secondary_super_cache();
719 guarantee(ko->is_klass(), "should be klass");
720 }
721 for ( uint i = 0; i < primary_super_limit(); i++ ) {
722 Klass* ko = _primary_supers[i];
723 if (ko != NULL) {
724 guarantee(ko->is_klass(), "should be klass");
725 }
726 }
727
728 if (java_mirror() != NULL) {
729 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
730 }
731 }
732
733 void Klass::oop_verify_on(oop obj, outputStream* st) {
734 guarantee(oopDesc::is_oop(obj), "should be oop");
735 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
736 }
737
738 klassVtable Klass::vtable() const {
739 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
740 }
741
742 vtableEntry* Klass::start_of_vtable() const {
743 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
744 }
745
746 Method* Klass::method_at_vtable(int index) {
747 #ifndef PRODUCT
748 assert(index >= 0, "valid vtable index");
749 if (DebugVtables) {
750 verify_vtable_index(index);
751 }
752 #endif
753 return start_of_vtable()[index].method();
754 }
755
756 ByteSize Klass::vtable_start_offset() {
757 return in_ByteSize(InstanceKlass::header_size() * wordSize);
758 }
759
760 #ifndef PRODUCT
761
762 bool Klass::verify_vtable_index(int i) {
763 int limit = vtable_length()/vtableEntry::size();
764 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
765 return true;
766 }
767
768 bool Klass::verify_itable_index(int i) {
769 assert(is_instance_klass(), "");
770 int method_count = klassItable::method_count_for_interface(this);
771 assert(i >= 0 && i < method_count, "index out of bounds");
772 return true;
773 }
774
775 #endif // PRODUCT
776
777 // The caller of class_loader_and_module_name() (or one of its callers)
778 // must use a ResourceMark in order to correctly free the result.
779 const char* Klass::class_loader_and_module_name() const {
780 const char* delim = "/";
781 size_t delim_len = strlen(delim);
782
783 const char* fqn = external_name();
784 // Length of message to return; always include FQN
785 size_t msglen = strlen(fqn) + 1;
786
787 bool has_cl_name = false;
788 bool has_mod_name = false;
789 bool has_version = false;
790
791 // Use class loader name, if exists and not builtin
792 const char* class_loader_name = "";
793 ClassLoaderData* cld = class_loader_data();
794 assert(cld != NULL, "class_loader_data should not be NULL");
795 if (!cld->is_builtin_class_loader_data()) {
796 // If not builtin, look for name
797 oop loader = class_loader();
798 if (loader != NULL) {
799 oop class_loader_name_oop = java_lang_ClassLoader::name(loader);
800 if (class_loader_name_oop != NULL) {
801 class_loader_name = java_lang_String::as_utf8_string(class_loader_name_oop);
802 if (class_loader_name != NULL && class_loader_name[0] != '\0') {
803 has_cl_name = true;
804 msglen += strlen(class_loader_name) + delim_len;
805 }
806 }
807 }
808 }
809
810 const char* module_name = "";
811 const char* version = "";
812 const Klass* bottom_klass = is_objArray_klass() ?
813 ObjArrayKlass::cast(this)->bottom_klass() : this;
814 if (bottom_klass->is_instance_klass()) {
815 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
816 // Use module name, if exists
817 if (module->is_named()) {
818 has_mod_name = true;
819 module_name = module->name()->as_C_string();
820 msglen += strlen(module_name);
821 // Use version if exists and is not a jdk module
822 if (module->is_non_jdk_module() && module->version() != NULL) {
823 has_version = true;
824 version = module->version()->as_C_string();
825 msglen += strlen("@") + strlen(version);
826 }
827 }
828 } else {
829 // klass is an array of primitives, so its module is java.base
830 module_name = JAVA_BASE_NAME;
831 }
832
833 if (has_cl_name || has_mod_name) {
834 msglen += delim_len;
835 }
836
837 char* message = NEW_RESOURCE_ARRAY_RETURN_NULL(char, msglen);
838
839 // Just return the FQN if error in allocating string
840 if (message == NULL) {
841 return fqn;
842 }
843
844 jio_snprintf(message, msglen, "%s%s%s%s%s%s%s",
845 class_loader_name,
846 (has_cl_name) ? delim : "",
847 (has_mod_name) ? module_name : "",
848 (has_version) ? "@" : "",
849 (has_version) ? version : "",
850 (has_cl_name || has_mod_name) ? delim : "",
851 fqn);
852 return message;
853 }