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/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
47 void Klass::set_java_mirror(Handle m) {
48 assert(!m.is_null(), "New mirror should never be null.");
49 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
50 _java_mirror = class_loader_data()->add_handle(m);
51 }
52
53 oop Klass::java_mirror() const {
54 return _java_mirror.resolve();
55 }
56
57 bool Klass::is_cloneable() const {
58 return _access_flags.is_cloneable_fast() ||
59 is_subtype_of(SystemDictionary::Cloneable_klass());
60 }
61
62 void Klass::set_is_cloneable() {
63 if (name() != vmSymbols::java_lang_invoke_MemberName()) {
64 _access_flags.set_is_cloneable_fast();
65 } else {
66 assert(is_final(), "no subclasses allowed");
67 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
68 }
69 }
70
71 void Klass::set_name(Symbol* n) {
72 _name = n;
73 if (_name != NULL) _name->increment_refcount();
74 }
75
76 bool Klass::is_subclass_of(const Klass* k) const {
77 // Run up the super chain and check
78 if (this == k) return true;
79
80 Klass* t = const_cast<Klass*>(this)->super();
81
82 while (t != NULL) {
83 if (t == k) return true;
84 t = t->super();
85 }
86 return false;
87 }
88
89 bool Klass::search_secondary_supers(Klass* k) const {
90 // Put some extra logic here out-of-line, before the search proper.
91 // This cuts down the size of the inline method.
92
93 // This is necessary, since I am never in my own secondary_super list.
94 if (this == k)
95 return true;
96 // Scan the array-of-objects for a match
97 int cnt = secondary_supers()->length();
98 for (int i = 0; i < cnt; i++) {
99 if (secondary_supers()->at(i) == k) {
100 ((Klass*)this)->set_secondary_super_cache(k);
101 return true;
102 }
103 }
104 return false;
105 }
106
107 // Return self, except for abstract classes with exactly 1
108 // implementor. Then return the 1 concrete implementation.
109 Klass *Klass::up_cast_abstract() {
110 Klass *r = this;
111 while( r->is_abstract() ) { // Receiver is abstract?
112 Klass *s = r->subklass(); // Check for exactly 1 subklass
113 if( !s || s->next_sibling() ) // Oops; wrong count; give up
114 return this; // Return 'this' as a no-progress flag
115 r = s; // Loop till find concrete class
116 }
117 return r; // Return the 1 concrete class
118 }
119
120 // Find LCA in class hierarchy
121 Klass *Klass::LCA( Klass *k2 ) {
122 Klass *k1 = this;
123 while( 1 ) {
124 if( k1->is_subtype_of(k2) ) return k2;
125 if( k2->is_subtype_of(k1) ) return k1;
126 k1 = k1->super();
127 k2 = k2->super();
128 }
129 }
130
131
132 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
133 ResourceMark rm(THREAD);
134 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
135 : vmSymbols::java_lang_InstantiationException(), external_name());
136 }
137
138
139 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
140 THROW(vmSymbols::java_lang_ArrayStoreException());
141 }
142
143
144 void Klass::initialize(TRAPS) {
145 ShouldNotReachHere();
146 }
147
148 bool Klass::compute_is_subtype_of(Klass* k) {
149 assert(k->is_klass(), "argument must be a class");
150 return is_subclass_of(k);
151 }
152
153 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
154 #ifdef ASSERT
155 tty->print_cr("Error: find_field called on a klass oop."
156 " Likely error: reflection method does not correctly"
157 " wrap return value in a mirror object.");
158 #endif
159 ShouldNotReachHere();
160 return NULL;
161 }
162
163 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
164 #ifdef ASSERT
165 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
166 " Likely error: reflection method does not correctly"
167 " wrap return value in a mirror object.");
168 #endif
169 ShouldNotReachHere();
170 return NULL;
171 }
172
173 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
174 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
175 }
176
177 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
178 // which zeros out memory - calloc equivalent.
179 // The constructor is also used from CppVtableCloner,
180 // which doesn't zero out the memory before calling the constructor.
181 // Need to set the _java_mirror field explicitly to not hit an assert that the field
182 // should be NULL before setting it.
183 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
184 _shared_class_path_index(-1),
185 _java_mirror(NULL) {
186 CDS_ONLY(_shared_class_flags = 0;)
187 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
188 _primary_supers[0] = this;
189 set_super_check_offset(in_bytes(primary_supers_offset()));
190 }
191
192 jint Klass::array_layout_helper(BasicType etype) {
193 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
194 // Note that T_ARRAY is not allowed here.
195 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
196 int esize = type2aelembytes(etype);
197 bool isobj = (etype == T_OBJECT);
198 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
199 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
200
201 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
202 assert(layout_helper_is_array(lh), "correct kind");
203 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
204 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
205 assert(layout_helper_header_size(lh) == hsize, "correct decode");
206 assert(layout_helper_element_type(lh) == etype, "correct decode");
207 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
208
209 return lh;
210 }
211
212 bool Klass::can_be_primary_super_slow() const {
213 if (super() == NULL)
214 return true;
215 else if (super()->super_depth() >= primary_super_limit()-1)
216 return false;
217 else
218 return true;
219 }
220
221 void Klass::initialize_supers(Klass* k, TRAPS) {
222 if (FastSuperclassLimit == 0) {
223 // None of the other machinery matters.
224 set_super(k);
225 return;
226 }
227 if (k == NULL) {
228 set_super(NULL);
229 _primary_supers[0] = this;
230 assert(super_depth() == 0, "Object must already be initialized properly");
231 } else if (k != super() || k == SystemDictionary::Object_klass()) {
232 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
233 "initialize this only once to a non-trivial value");
234 set_super(k);
235 Klass* sup = k;
236 int sup_depth = sup->super_depth();
237 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
238 if (!can_be_primary_super_slow())
239 my_depth = primary_super_limit();
240 for (juint i = 0; i < my_depth; i++) {
241 _primary_supers[i] = sup->_primary_supers[i];
242 }
243 Klass* *super_check_cell;
244 if (my_depth < primary_super_limit()) {
245 _primary_supers[my_depth] = this;
246 super_check_cell = &_primary_supers[my_depth];
247 } else {
248 // Overflow of the primary_supers array forces me to be secondary.
249 super_check_cell = &_secondary_super_cache;
250 }
251 set_super_check_offset((address)super_check_cell - (address) this);
252
253 #ifdef ASSERT
254 {
255 juint j = super_depth();
256 assert(j == my_depth, "computed accessor gets right answer");
257 Klass* t = this;
258 while (!t->can_be_primary_super()) {
259 t = t->super();
260 j = t->super_depth();
261 }
262 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
263 assert(primary_super_of_depth(j1) == NULL, "super list padding");
264 }
265 while (t != NULL) {
266 assert(primary_super_of_depth(j) == t, "super list initialization");
267 t = t->super();
268 --j;
269 }
270 assert(j == (juint)-1, "correct depth count");
271 }
272 #endif
273 }
274
275 if (secondary_supers() == NULL) {
276
277 // Now compute the list of secondary supertypes.
278 // Secondaries can occasionally be on the super chain,
279 // if the inline "_primary_supers" array overflows.
280 int extras = 0;
281 Klass* p;
282 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
283 ++extras;
284 }
285
286 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
287
288 // Compute the "real" non-extra secondaries.
289 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
290 if (secondaries == NULL) {
291 // secondary_supers set by compute_secondary_supers
292 return;
293 }
294
295 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
296
297 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
298 int i; // Scan for overflow primaries being duplicates of 2nd'arys
299
300 // This happens frequently for very deeply nested arrays: the
301 // primary superclass chain overflows into the secondary. The
302 // secondary list contains the element_klass's secondaries with
303 // an extra array dimension added. If the element_klass's
304 // secondary list already contains some primary overflows, they
305 // (with the extra level of array-ness) will collide with the
306 // normal primary superclass overflows.
307 for( i = 0; i < secondaries->length(); i++ ) {
308 if( secondaries->at(i) == p )
309 break;
310 }
311 if( i < secondaries->length() )
312 continue; // It's a dup, don't put it in
313 primaries->push(p);
314 }
315 // Combine the two arrays into a metadata object to pack the array.
316 // The primaries are added in the reverse order, then the secondaries.
317 int new_length = primaries->length() + secondaries->length();
318 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
319 class_loader_data(), new_length, CHECK);
320 int fill_p = primaries->length();
321 for (int j = 0; j < fill_p; j++) {
322 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
323 }
324 for( int j = 0; j < secondaries->length(); j++ ) {
325 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
326 }
327
328 #ifdef ASSERT
329 // We must not copy any NULL placeholders left over from bootstrap.
330 for (int j = 0; j < s2->length(); j++) {
331 assert(s2->at(j) != NULL, "correct bootstrapping order");
332 }
333 #endif
334
335 set_secondary_supers(s2);
336 }
337 }
338
339 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
340 assert(num_extra_slots == 0, "override for complex klasses");
341 set_secondary_supers(Universe::the_empty_klass_array());
342 return NULL;
343 }
344
345
346 InstanceKlass* Klass::superklass() const {
347 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
348 return _super == NULL ? NULL : InstanceKlass::cast(_super);
349 }
350
351 void Klass::set_subklass(Klass* s) {
352 assert(s != this, "sanity check");
353 _subklass = s;
354 }
355
356 void Klass::set_next_sibling(Klass* s) {
357 assert(s != this, "sanity check");
358 _next_sibling = s;
359 }
360
361 void Klass::append_to_sibling_list() {
362 debug_only(verify();)
363 // add ourselves to superklass' subklass list
364 InstanceKlass* super = superklass();
365 if (super == NULL) return; // special case: class Object
366 assert((!super->is_interface() // interfaces cannot be supers
367 && (super->superklass() == NULL || !is_interface())),
368 "an interface can only be a subklass of Object");
369 Klass* prev_first_subklass = super->subklass();
370 if (prev_first_subklass != NULL) {
371 // set our sibling to be the superklass' previous first subklass
372 set_next_sibling(prev_first_subklass);
373 }
374 // make ourselves the superklass' first subklass
375 super->set_subklass(this);
376 debug_only(verify();)
377 }
378
379 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
380 #ifdef ASSERT
381 // The class is alive iff the class loader is alive.
382 oop loader = class_loader();
383 bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
384 #endif // ASSERT
385
386 // The class is alive if it's mirror is alive (which should be marked if the
387 // loader is alive) unless it's an anoymous class.
388 bool mirror_alive = is_alive->do_object_b(java_mirror());
389 assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
390 " but not the other way around with anonymous classes");
391 return mirror_alive;
392 }
393
394 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
395 if (!ClassUnloading) {
396 return;
397 }
398
399 Klass* root = SystemDictionary::Object_klass();
400 Stack<Klass*, mtGC> stack;
401
402 stack.push(root);
403 while (!stack.is_empty()) {
404 Klass* current = stack.pop();
405
406 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
407
408 // Find and set the first alive subklass
409 Klass* sub = current->subklass();
410 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
411 #ifndef PRODUCT
412 if (log_is_enabled(Trace, class, unload)) {
413 ResourceMark rm;
414 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
415 }
416 #endif
417 sub = sub->next_sibling();
418 }
419 current->set_subklass(sub);
420 if (sub != NULL) {
421 stack.push(sub);
422 }
423
424 // Find and set the first alive sibling
425 Klass* sibling = current->next_sibling();
426 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
427 if (log_is_enabled(Trace, class, unload)) {
428 ResourceMark rm;
429 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
430 }
431 sibling = sibling->next_sibling();
432 }
433 current->set_next_sibling(sibling);
434 if (sibling != NULL) {
435 stack.push(sibling);
436 }
437
438 // Clean the implementors list and method data.
439 if (clean_alive_klasses && current->is_instance_klass()) {
440 InstanceKlass* ik = InstanceKlass::cast(current);
441 ik->clean_weak_instanceklass_links(is_alive);
442
443 // JVMTI RedefineClasses creates previous versions that are not in
444 // the class hierarchy, so process them here.
445 while ((ik = ik->previous_versions()) != NULL) {
446 ik->clean_weak_instanceklass_links(is_alive);
447 }
448 }
449 }
450 }
451
452 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
453 if (log_is_enabled(Trace, cds)) {
454 ResourceMark rm;
455 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
456 }
457
458 it->push(&_name);
459 it->push(&_secondary_super_cache);
460 it->push(&_secondary_supers);
461 for (int i = 0; i < _primary_super_limit; i++) {
462 it->push(&_primary_supers[i]);
463 }
464 it->push(&_super);
465 it->push(&_subklass);
466 it->push(&_next_sibling);
467 it->push(&_next_link);
468
469 vtableEntry* vt = start_of_vtable();
470 for (int i=0; i<vtable_length(); i++) {
471 it->push(vt[i].method_addr());
472 }
473 }
474
475 void Klass::remove_unshareable_info() {
476 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
477 TRACE_REMOVE_ID(this);
478 if (log_is_enabled(Trace, cds, unshareable)) {
479 ResourceMark rm;
480 log_trace(cds, unshareable)("remove: %s", external_name());
481 }
482
483 set_subklass(NULL);
484 set_next_sibling(NULL);
485 set_next_link(NULL);
486
487 // Null out class_loader_data because we don't share that yet.
488 set_class_loader_data(NULL);
489 set_is_shared();
490 }
491
492 void Klass::remove_java_mirror() {
493 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
494 if (log_is_enabled(Trace, cds, unshareable)) {
495 ResourceMark rm;
496 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
497 }
498 // Just null out the mirror. The class_loader_data() no longer exists.
499 _java_mirror = NULL;
500 }
501
502 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
503 assert(is_klass(), "ensure C++ vtable is restored");
504 assert(is_shared(), "must be set");
505 TRACE_RESTORE_ID(this);
506 if (log_is_enabled(Trace, cds, unshareable)) {
507 ResourceMark rm;
508 log_trace(cds, unshareable)("restore: %s", external_name());
509 }
510
511 // If an exception happened during CDS restore, some of these fields may already be
512 // set. We leave the class on the CLD list, even if incomplete so that we don't
513 // modify the CLD list outside a safepoint.
514 if (class_loader_data() == NULL) {
515 // Restore class_loader_data to the null class loader data
516 set_class_loader_data(loader_data);
517
518 // Add to null class loader list first before creating the mirror
519 // (same order as class file parsing)
520 loader_data->add_class(this);
521 }
522
523 Handle loader(THREAD, loader_data->class_loader());
524 ModuleEntry* module_entry = NULL;
525 Klass* k = this;
526 if (k->is_objArray_klass()) {
527 k = ObjArrayKlass::cast(k)->bottom_klass();
528 }
529 // Obtain klass' module.
530 if (k->is_instance_klass()) {
531 InstanceKlass* ik = (InstanceKlass*) k;
532 module_entry = ik->module();
533 } else {
534 module_entry = ModuleEntryTable::javabase_moduleEntry();
535 }
536 // Obtain java.lang.Module, if available
537 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
538
539 if (this->has_raw_archived_mirror()) {
540 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
541 if (MetaspaceShared::open_archive_heap_region_mapped()) {
542 oop m = archived_java_mirror();
543 log_debug(cds, mirror)("Archived mirror is: " PTR_FORMAT, p2i(m));
544 if (m != NULL) {
545 // mirror is archived, restore
546 assert(oopDesc::is_archive_object(m), "must be archived mirror object");
547 Handle m_h(THREAD, m);
548 java_lang_Class::restore_archived_mirror(this, m_h, loader, module_handle, protection_domain, CHECK);
549 return;
550 }
551 }
552
553 // No archived mirror data
554 _java_mirror = NULL;
555 this->clear_has_raw_archived_mirror();
556 }
557
558 // Only recreate it if not present. A previous attempt to restore may have
559 // gotten an OOM later but keep the mirror if it was created.
560 if (java_mirror() == NULL) {
561 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
562 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
563 }
564 }
565
566 #if INCLUDE_CDS_JAVA_HEAP
567 // Used at CDS dump time to access the archived mirror. No GC barrier.
568 oop Klass::archived_java_mirror_raw() {
569 assert(DumpSharedSpaces, "called only during runtime");
570 assert(has_raw_archived_mirror(), "must have raw archived mirror");
571 return oopDesc::decode_heap_oop(_archived_mirror);
572 }
573
574 // Used at CDS runtime to get the archived mirror from shared class. Uses GC barrier.
575 oop Klass::archived_java_mirror() {
576 assert(UseSharedSpaces, "UseSharedSpaces expected.");
577 assert(has_raw_archived_mirror(), "must have raw archived mirror");
578 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_mirror);
579 }
580
581 // No GC barrier
582 void Klass::set_archived_java_mirror_raw(oop m) {
583 assert(DumpSharedSpaces, "called only during runtime");
584 _archived_mirror = oopDesc::encode_heap_oop(m);
585 }
586 #endif // INCLUDE_CDS_JAVA_HEAP
587
588 Klass* Klass::array_klass_or_null(int rank) {
589 EXCEPTION_MARK;
590 // No exception can be thrown by array_klass_impl when called with or_null == true.
591 // (In anycase, the execption mark will fail if it do so)
592 return array_klass_impl(true, rank, THREAD);
593 }
594
595
596 Klass* Klass::array_klass_or_null() {
597 EXCEPTION_MARK;
598 // No exception can be thrown by array_klass_impl when called with or_null == true.
599 // (In anycase, the execption mark will fail if it do so)
600 return array_klass_impl(true, THREAD);
601 }
602
603
604 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
605 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
606 return NULL;
607 }
608
609
610 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
611 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
612 return NULL;
613 }
614
615 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
616
617 // In product mode, this function doesn't have virtual function calls so
618 // there might be some performance advantage to handling InstanceKlass here.
619 const char* Klass::external_name() const {
620 if (is_instance_klass()) {
621 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
622 if (ik->is_anonymous()) {
623 char addr_buf[20];
624 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
625 size_t addr_len = strlen(addr_buf);
626 size_t name_len = name()->utf8_length();
627 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
628 name()->as_klass_external_name(result, (int) name_len + 1);
629 assert(strlen(result) == name_len, "");
630 strcpy(result + name_len, addr_buf);
631 assert(strlen(result) == name_len + addr_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 // 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 }