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/compressedOops.inline.hpp"
39 #include "oops/instanceKlass.hpp"
40 #include "oops/klass.inline.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/atomic.hpp"
43 #include "runtime/handles.inline.hpp"
44 #include "runtime/orderAccess.inline.hpp"
45 #include "trace/traceMacros.hpp"
46 #include "utilities/macros.hpp"
47 #include "utilities/stack.inline.hpp"
48
49 void Klass::set_java_mirror(Handle m) {
50 assert(!m.is_null(), "New mirror should never be null.");
51 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
52 _java_mirror = class_loader_data()->add_handle(m);
53 }
54
55 oop Klass::java_mirror() const {
56 return _java_mirror.resolve();
57 }
58
59 bool Klass::is_cloneable() const {
60 return _access_flags.is_cloneable_fast() ||
61 is_subtype_of(SystemDictionary::Cloneable_klass());
62 }
63
64 void Klass::set_is_cloneable() {
65 if (name() != vmSymbols::java_lang_invoke_MemberName()) {
66 _access_flags.set_is_cloneable_fast();
67 } else {
68 assert(is_final(), "no subclasses allowed");
69 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
70 }
71 }
72
73 void Klass::set_name(Symbol* n) {
74 _name = n;
75 if (_name != NULL) _name->increment_refcount();
76 }
77
78 bool Klass::is_subclass_of(const Klass* k) const {
79 // Run up the super chain and check
80 if (this == k) return true;
81
82 Klass* t = const_cast<Klass*>(this)->super();
83
84 while (t != NULL) {
85 if (t == k) return true;
86 t = t->super();
87 }
88 return false;
89 }
90
91 bool Klass::search_secondary_supers(Klass* k) const {
92 // Put some extra logic here out-of-line, before the search proper.
93 // This cuts down the size of the inline method.
94
95 // This is necessary, since I am never in my own secondary_super list.
96 if (this == k)
97 return true;
98 // Scan the array-of-objects for a match
99 int cnt = secondary_supers()->length();
100 for (int i = 0; i < cnt; i++) {
101 if (secondary_supers()->at(i) == k) {
102 ((Klass*)this)->set_secondary_super_cache(k);
103 return true;
104 }
105 }
106 return false;
107 }
108
109 // Return self, except for abstract classes with exactly 1
110 // implementor. Then return the 1 concrete implementation.
111 Klass *Klass::up_cast_abstract() {
112 Klass *r = this;
113 while( r->is_abstract() ) { // Receiver is abstract?
114 Klass *s = r->subklass(); // Check for exactly 1 subklass
115 if( !s || s->next_sibling() ) // Oops; wrong count; give up
116 return this; // Return 'this' as a no-progress flag
117 r = s; // Loop till find concrete class
118 }
119 return r; // Return the 1 concrete class
120 }
121
122 // Find LCA in class hierarchy
123 Klass *Klass::LCA( Klass *k2 ) {
124 Klass *k1 = this;
125 while( 1 ) {
126 if( k1->is_subtype_of(k2) ) return k2;
127 if( k2->is_subtype_of(k1) ) return k1;
128 k1 = k1->super();
129 k2 = k2->super();
130 }
131 }
132
133
134 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
135 ResourceMark rm(THREAD);
136 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
137 : vmSymbols::java_lang_InstantiationException(), external_name());
138 }
139
140
141 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
142 THROW(vmSymbols::java_lang_ArrayStoreException());
143 }
144
145
146 void Klass::initialize(TRAPS) {
147 ShouldNotReachHere();
148 }
149
150 bool Klass::compute_is_subtype_of(Klass* k) {
151 assert(k->is_klass(), "argument must be a class");
152 return is_subclass_of(k);
153 }
154
155 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
156 #ifdef ASSERT
157 tty->print_cr("Error: find_field called on a klass oop."
158 " Likely error: reflection method does not correctly"
159 " wrap return value in a mirror object.");
160 #endif
161 ShouldNotReachHere();
162 return NULL;
163 }
164
165 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
166 #ifdef ASSERT
167 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
168 " Likely error: reflection method does not correctly"
169 " wrap return value in a mirror object.");
170 #endif
171 ShouldNotReachHere();
172 return NULL;
173 }
174
175 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
176 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
177 }
178
179 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
180 // which zeros out memory - calloc equivalent.
181 // The constructor is also used from CppVtableCloner,
182 // which doesn't zero out the memory before calling the constructor.
183 // Need to set the _java_mirror field explicitly to not hit an assert that the field
184 // should be NULL before setting it.
185 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
186 _shared_class_path_index(-1),
187 _java_mirror(NULL) {
188 CDS_ONLY(_shared_class_flags = 0;)
189 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
190 _primary_supers[0] = this;
191 set_super_check_offset(in_bytes(primary_supers_offset()));
192 }
193
194 jint Klass::array_layout_helper(BasicType etype) {
195 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
196 // Note that T_ARRAY is not allowed here.
197 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
198 int esize = type2aelembytes(etype);
199 bool isobj = (etype == T_OBJECT);
200 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
201 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
202
203 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
204 assert(layout_helper_is_array(lh), "correct kind");
205 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
206 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
207 assert(layout_helper_header_size(lh) == hsize, "correct decode");
208 assert(layout_helper_element_type(lh) == etype, "correct decode");
209 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
210
211 return lh;
212 }
213
214 bool Klass::can_be_primary_super_slow() const {
215 if (super() == NULL)
216 return true;
217 else if (super()->super_depth() >= primary_super_limit()-1)
218 return false;
219 else
220 return true;
221 }
222
223 void Klass::initialize_supers(Klass* k, TRAPS) {
224 if (FastSuperclassLimit == 0) {
225 // None of the other machinery matters.
226 set_super(k);
227 return;
228 }
229 if (k == NULL) {
230 set_super(NULL);
231 _primary_supers[0] = this;
232 assert(super_depth() == 0, "Object must already be initialized properly");
233 } else if (k != super() || k == SystemDictionary::Object_klass()) {
234 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
235 "initialize this only once to a non-trivial value");
236 set_super(k);
237 Klass* sup = k;
238 int sup_depth = sup->super_depth();
239 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
240 if (!can_be_primary_super_slow())
241 my_depth = primary_super_limit();
242 for (juint i = 0; i < my_depth; i++) {
243 _primary_supers[i] = sup->_primary_supers[i];
244 }
245 Klass* *super_check_cell;
246 if (my_depth < primary_super_limit()) {
247 _primary_supers[my_depth] = this;
248 super_check_cell = &_primary_supers[my_depth];
249 } else {
250 // Overflow of the primary_supers array forces me to be secondary.
251 super_check_cell = &_secondary_super_cache;
252 }
253 set_super_check_offset((address)super_check_cell - (address) this);
254
255 #ifdef ASSERT
256 {
257 juint j = super_depth();
258 assert(j == my_depth, "computed accessor gets right answer");
259 Klass* t = this;
260 while (!t->can_be_primary_super()) {
261 t = t->super();
262 j = t->super_depth();
263 }
264 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
265 assert(primary_super_of_depth(j1) == NULL, "super list padding");
266 }
267 while (t != NULL) {
268 assert(primary_super_of_depth(j) == t, "super list initialization");
269 t = t->super();
270 --j;
271 }
272 assert(j == (juint)-1, "correct depth count");
273 }
274 #endif
275 }
276
277 if (secondary_supers() == NULL) {
278
279 // Now compute the list of secondary supertypes.
280 // Secondaries can occasionally be on the super chain,
281 // if the inline "_primary_supers" array overflows.
282 int extras = 0;
283 Klass* p;
284 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
285 ++extras;
286 }
287
288 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
289
290 // Compute the "real" non-extra secondaries.
291 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
292 if (secondaries == NULL) {
293 // secondary_supers set by compute_secondary_supers
294 return;
295 }
296
297 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
298
299 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
300 int i; // Scan for overflow primaries being duplicates of 2nd'arys
301
302 // This happens frequently for very deeply nested arrays: the
303 // primary superclass chain overflows into the secondary. The
304 // secondary list contains the element_klass's secondaries with
305 // an extra array dimension added. If the element_klass's
306 // secondary list already contains some primary overflows, they
307 // (with the extra level of array-ness) will collide with the
308 // normal primary superclass overflows.
309 for( i = 0; i < secondaries->length(); i++ ) {
310 if( secondaries->at(i) == p )
311 break;
312 }
313 if( i < secondaries->length() )
314 continue; // It's a dup, don't put it in
315 primaries->push(p);
316 }
317 // Combine the two arrays into a metadata object to pack the array.
318 // The primaries are added in the reverse order, then the secondaries.
319 int new_length = primaries->length() + secondaries->length();
320 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
321 class_loader_data(), new_length, CHECK);
322 int fill_p = primaries->length();
323 for (int j = 0; j < fill_p; j++) {
324 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
325 }
326 for( int j = 0; j < secondaries->length(); j++ ) {
327 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
328 }
329
330 #ifdef ASSERT
331 // We must not copy any NULL placeholders left over from bootstrap.
332 for (int j = 0; j < s2->length(); j++) {
333 assert(s2->at(j) != NULL, "correct bootstrapping order");
334 }
335 #endif
336
337 set_secondary_supers(s2);
338 }
339 }
340
341 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
342 assert(num_extra_slots == 0, "override for complex klasses");
343 set_secondary_supers(Universe::the_empty_klass_array());
344 return NULL;
345 }
346
347
348 InstanceKlass* Klass::superklass() const {
349 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
350 return _super == NULL ? NULL : InstanceKlass::cast(_super);
351 }
352
353 void Klass::set_subklass(Klass* s) {
354 assert(s != this, "sanity check");
355 _subklass = s;
356 }
357
358 void Klass::set_next_sibling(Klass* s) {
359 assert(s != this, "sanity check");
360 _next_sibling = s;
361 }
362
363 void Klass::append_to_sibling_list() {
364 debug_only(verify();)
365 // add ourselves to superklass' subklass list
366 InstanceKlass* super = superklass();
367 if (super == NULL) return; // special case: class Object
368 assert((!super->is_interface() // interfaces cannot be supers
369 && (super->superklass() == NULL || !is_interface())),
370 "an interface can only be a subklass of Object");
371 Klass* prev_first_subklass = super->subklass();
372 if (prev_first_subklass != NULL) {
373 // set our sibling to be the superklass' previous first subklass
374 set_next_sibling(prev_first_subklass);
375 }
376 // make ourselves the superklass' first subklass
377 super->set_subklass(this);
378 debug_only(verify();)
379 }
380
381 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
382 #ifdef ASSERT
383 // The class is alive iff the class loader is alive.
384 oop loader = class_loader();
385 bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
386 #endif // ASSERT
387
388 // The class is alive if it's mirror is alive (which should be marked if the
389 // loader is alive) unless it's an anoymous class.
390 bool mirror_alive = is_alive->do_object_b(java_mirror());
391 assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
392 " but not the other way around with anonymous classes");
393 return mirror_alive;
394 }
395
396 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
397 if (!ClassUnloading) {
398 return;
399 }
400
401 Klass* root = SystemDictionary::Object_klass();
402 Stack<Klass*, mtGC> stack;
403
404 stack.push(root);
405 while (!stack.is_empty()) {
406 Klass* current = stack.pop();
407
408 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
409
410 // Find and set the first alive subklass
411 Klass* sub = current->subklass();
412 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
413 #ifndef PRODUCT
414 if (log_is_enabled(Trace, class, unload)) {
415 ResourceMark rm;
416 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
417 }
418 #endif
419 sub = sub->next_sibling();
420 }
421 current->set_subklass(sub);
422 if (sub != NULL) {
423 stack.push(sub);
424 }
425
426 // Find and set the first alive sibling
427 Klass* sibling = current->next_sibling();
428 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
429 if (log_is_enabled(Trace, class, unload)) {
430 ResourceMark rm;
431 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
432 }
433 sibling = sibling->next_sibling();
434 }
435 current->set_next_sibling(sibling);
436 if (sibling != NULL) {
437 stack.push(sibling);
438 }
439
440 // Clean the implementors list and method data.
441 if (clean_alive_klasses && current->is_instance_klass()) {
442 InstanceKlass* ik = InstanceKlass::cast(current);
443 ik->clean_weak_instanceklass_links(is_alive);
444
445 // JVMTI RedefineClasses creates previous versions that are not in
446 // the class hierarchy, so process them here.
447 while ((ik = ik->previous_versions()) != NULL) {
448 ik->clean_weak_instanceklass_links(is_alive);
449 }
450 }
451 }
452 }
453
454 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
455 if (log_is_enabled(Trace, cds)) {
456 ResourceMark rm;
457 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
458 }
459
460 it->push(&_name);
461 it->push(&_secondary_super_cache);
462 it->push(&_secondary_supers);
463 for (int i = 0; i < _primary_super_limit; i++) {
464 it->push(&_primary_supers[i]);
465 }
466 it->push(&_super);
467 it->push(&_subklass);
468 it->push(&_next_sibling);
469 it->push(&_next_link);
470
471 vtableEntry* vt = start_of_vtable();
472 for (int i=0; i<vtable_length(); i++) {
473 it->push(vt[i].method_addr());
474 }
475 }
476
477 void Klass::remove_unshareable_info() {
478 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
479 TRACE_REMOVE_ID(this);
480 if (log_is_enabled(Trace, cds, unshareable)) {
481 ResourceMark rm;
482 log_trace(cds, unshareable)("remove: %s", external_name());
483 }
484
485 set_subklass(NULL);
486 set_next_sibling(NULL);
487 set_next_link(NULL);
488
489 // Null out class_loader_data because we don't share that yet.
490 set_class_loader_data(NULL);
491 set_is_shared();
492 }
493
494 void Klass::remove_java_mirror() {
495 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
496 if (log_is_enabled(Trace, cds, unshareable)) {
497 ResourceMark rm;
498 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
499 }
500 // Just null out the mirror. The class_loader_data() no longer exists.
501 _java_mirror = NULL;
502 }
503
504 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
505 assert(is_klass(), "ensure C++ vtable is restored");
506 assert(is_shared(), "must be set");
507 TRACE_RESTORE_ID(this);
508 if (log_is_enabled(Trace, cds, unshareable)) {
509 ResourceMark rm;
510 log_trace(cds, unshareable)("restore: %s", external_name());
511 }
512
513 // If an exception happened during CDS restore, some of these fields may already be
514 // set. We leave the class on the CLD list, even if incomplete so that we don't
515 // modify the CLD list outside a safepoint.
516 if (class_loader_data() == NULL) {
517 // Restore class_loader_data to the null class loader data
518 set_class_loader_data(loader_data);
519
520 // Add to null class loader list first before creating the mirror
521 // (same order as class file parsing)
522 loader_data->add_class(this);
523 }
524
525 Handle loader(THREAD, loader_data->class_loader());
526 ModuleEntry* module_entry = NULL;
527 Klass* k = this;
528 if (k->is_objArray_klass()) {
529 k = ObjArrayKlass::cast(k)->bottom_klass();
530 }
531 // Obtain klass' module.
532 if (k->is_instance_klass()) {
533 InstanceKlass* ik = (InstanceKlass*) k;
534 module_entry = ik->module();
535 } else {
536 module_entry = ModuleEntryTable::javabase_moduleEntry();
537 }
538 // Obtain java.lang.Module, if available
539 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
540
541 if (this->has_raw_archived_mirror()) {
542 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
543 if (MetaspaceShared::open_archive_heap_region_mapped()) {
544 oop m = archived_java_mirror();
545 log_debug(cds, mirror)("Archived mirror is: " PTR_FORMAT, p2i(m));
546 if (m != NULL) {
547 // mirror is archived, restore
548 assert(oopDesc::is_archive_object(m), "must be archived mirror object");
549 Handle m_h(THREAD, m);
550 java_lang_Class::restore_archived_mirror(this, m_h, loader, module_handle, protection_domain, CHECK);
551 return;
552 }
553 }
554
555 // No archived mirror data
556 _java_mirror = NULL;
557 this->clear_has_raw_archived_mirror();
558 }
559
560 // Only recreate it if not present. A previous attempt to restore may have
561 // gotten an OOM later but keep the mirror if it was created.
562 if (java_mirror() == NULL) {
563 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
564 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
565 }
566 }
567
568 #if INCLUDE_CDS_JAVA_HEAP
569 // Used at CDS dump time to access the archived mirror. No GC barrier.
570 oop Klass::archived_java_mirror_raw() {
571 assert(DumpSharedSpaces, "called only during runtime");
572 assert(has_raw_archived_mirror(), "must have raw archived mirror");
573 return CompressedOops::decode(_archived_mirror);
574 }
575
576 // Used at CDS runtime to get the archived mirror from shared class. Uses GC barrier.
577 oop Klass::archived_java_mirror() {
578 assert(UseSharedSpaces, "UseSharedSpaces expected.");
579 assert(has_raw_archived_mirror(), "must have raw archived mirror");
580 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_mirror);
581 }
582
583 // No GC barrier
584 void Klass::set_archived_java_mirror_raw(oop m) {
585 assert(DumpSharedSpaces, "called only during runtime");
586 _archived_mirror = CompressedOops::encode(m);
587 }
588 #endif // INCLUDE_CDS_JAVA_HEAP
589
590 Klass* Klass::array_klass_or_null(int rank) {
591 EXCEPTION_MARK;
592 // No exception can be thrown by array_klass_impl when called with or_null == true.
593 // (In anycase, the execption mark will fail if it do so)
594 return array_klass_impl(true, rank, THREAD);
595 }
596
597
598 Klass* Klass::array_klass_or_null() {
599 EXCEPTION_MARK;
600 // No exception can be thrown by array_klass_impl when called with or_null == true.
601 // (In anycase, the execption mark will fail if it do so)
602 return array_klass_impl(true, THREAD);
603 }
604
605
606 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
607 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
608 return NULL;
609 }
610
611
612 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
613 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
614 return NULL;
615 }
616
617 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
618
619 // In product mode, this function doesn't have virtual function calls so
620 // there might be some performance advantage to handling InstanceKlass here.
621 const char* Klass::external_name() const {
622 if (is_instance_klass()) {
623 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
624 if (ik->is_anonymous()) {
625 char addr_buf[20];
626 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
627 size_t addr_len = strlen(addr_buf);
628 size_t name_len = name()->utf8_length();
629 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
630 name()->as_klass_external_name(result, (int) name_len + 1);
631 assert(strlen(result) == name_len, "");
632 strcpy(result + name_len, addr_buf);
633 assert(strlen(result) == name_len + addr_len, "");
634 return result;
635 }
636 }
637 if (name() == NULL) return "<unknown>";
638 return name()->as_klass_external_name();
639 }
640
641 const char* Klass::signature_name() const {
642 if (name() == NULL) return "<unknown>";
643 return name()->as_C_string();
644 }
645
646 const char* Klass::external_kind() const {
647 if (is_interface()) return "interface";
648 if (is_abstract()) return "abstract class";
649 return "class";
650 }
651
652 // Unless overridden, modifier_flags is 0.
653 jint Klass::compute_modifier_flags(TRAPS) const {
654 return 0;
655 }
656
657 int Klass::atomic_incr_biased_lock_revocation_count() {
658 return (int) Atomic::add(1, &_biased_lock_revocation_count);
659 }
660
661 // Unless overridden, jvmti_class_status has no flags set.
662 jint Klass::jvmti_class_status() const {
663 return 0;
664 }
665
666
667 // Printing
668
669 void Klass::print_on(outputStream* st) const {
670 ResourceMark rm;
671 // print title
672 st->print("%s", internal_name());
673 print_address_on(st);
674 st->cr();
675 }
676
677 void Klass::oop_print_on(oop obj, outputStream* st) {
678 ResourceMark rm;
679 // print title
680 st->print_cr("%s ", internal_name());
681 obj->print_address_on(st);
682
683 if (WizardMode) {
684 // print header
685 obj->mark()->print_on(st);
686 }
687
688 // print class
689 st->print(" - klass: ");
690 obj->klass()->print_value_on(st);
691 st->cr();
692 }
693
694 void Klass::oop_print_value_on(oop obj, outputStream* st) {
695 // print title
696 ResourceMark rm; // Cannot print in debug mode without this
697 st->print("%s", internal_name());
698 obj->print_address_on(st);
699 }
700
701 #if INCLUDE_SERVICES
702 // Size Statistics
703 void Klass::collect_statistics(KlassSizeStats *sz) const {
704 sz->_klass_bytes = sz->count(this);
705 sz->_mirror_bytes = sz->count(java_mirror());
706 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
707
708 sz->_ro_bytes += sz->_secondary_supers_bytes;
709 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
710 }
711 #endif // INCLUDE_SERVICES
712
713 // Verification
714
715 void Klass::verify_on(outputStream* st) {
716
717 // This can be expensive, but it is worth checking that this klass is actually
718 // in the CLD graph but not in production.
719 assert(Metaspace::contains((address)this), "Should be");
720
721 guarantee(this->is_klass(),"should be klass");
722
723 if (super() != NULL) {
724 guarantee(super()->is_klass(), "should be klass");
725 }
726 if (secondary_super_cache() != NULL) {
727 Klass* ko = secondary_super_cache();
728 guarantee(ko->is_klass(), "should be klass");
729 }
730 for ( uint i = 0; i < primary_super_limit(); i++ ) {
731 Klass* ko = _primary_supers[i];
732 if (ko != NULL) {
733 guarantee(ko->is_klass(), "should be klass");
734 }
735 }
736
737 if (java_mirror() != NULL) {
738 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
739 }
740 }
741
742 void Klass::oop_verify_on(oop obj, outputStream* st) {
743 guarantee(oopDesc::is_oop(obj), "should be oop");
744 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
745 }
746
747 klassVtable Klass::vtable() const {
748 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
749 }
750
751 vtableEntry* Klass::start_of_vtable() const {
752 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
753 }
754
755 Method* Klass::method_at_vtable(int index) {
756 #ifndef PRODUCT
757 assert(index >= 0, "valid vtable index");
758 if (DebugVtables) {
759 verify_vtable_index(index);
760 }
761 #endif
762 return start_of_vtable()[index].method();
763 }
764
765 ByteSize Klass::vtable_start_offset() {
766 return in_ByteSize(InstanceKlass::header_size() * wordSize);
767 }
768
769 #ifndef PRODUCT
770
771 bool Klass::verify_vtable_index(int i) {
772 int limit = vtable_length()/vtableEntry::size();
773 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
774 return true;
775 }
776
777 bool Klass::verify_itable_index(int i) {
778 assert(is_instance_klass(), "");
779 int method_count = klassItable::method_count_for_interface(this);
780 assert(i >= 0 && i < method_count, "index out of bounds");
781 return true;
782 }
783
784 #endif // PRODUCT
785
786 // The caller of class_loader_and_module_name() (or one of its callers)
787 // must use a ResourceMark in order to correctly free the result.
788 const char* Klass::class_loader_and_module_name() const {
789 const char* delim = "/";
790 size_t delim_len = strlen(delim);
791
792 const char* fqn = external_name();
793 // Length of message to return; always include FQN
794 size_t msglen = strlen(fqn) + 1;
795
796 bool has_cl_name = false;
797 bool has_mod_name = false;
798 bool has_version = false;
799
800 // Use class loader name, if exists and not builtin
801 const char* class_loader_name = "";
802 ClassLoaderData* cld = class_loader_data();
803 assert(cld != NULL, "class_loader_data should not be NULL");
804 if (!cld->is_builtin_class_loader_data()) {
805 // If not builtin, look for name
806 oop loader = class_loader();
807 if (loader != NULL) {
808 oop class_loader_name_oop = java_lang_ClassLoader::name(loader);
809 if (class_loader_name_oop != NULL) {
810 class_loader_name = java_lang_String::as_utf8_string(class_loader_name_oop);
811 if (class_loader_name != NULL && class_loader_name[0] != '\0') {
812 has_cl_name = true;
813 msglen += strlen(class_loader_name) + delim_len;
814 }
815 }
816 }
817 }
818
819 const char* module_name = "";
820 const char* version = "";
821 const Klass* bottom_klass = is_objArray_klass() ?
822 ObjArrayKlass::cast(this)->bottom_klass() : this;
823 if (bottom_klass->is_instance_klass()) {
824 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
825 // Use module name, if exists
826 if (module->is_named()) {
827 has_mod_name = true;
828 module_name = module->name()->as_C_string();
829 msglen += strlen(module_name);
830 // Use version if exists and is not a jdk module
831 if (module->is_non_jdk_module() && module->version() != NULL) {
832 has_version = true;
833 version = module->version()->as_C_string();
834 msglen += strlen("@") + strlen(version);
835 }
836 }
837 } else {
838 // klass is an array of primitives, so its module is java.base
839 module_name = JAVA_BASE_NAME;
840 }
841
842 if (has_cl_name || has_mod_name) {
843 msglen += delim_len;
844 }
845
846 char* message = NEW_RESOURCE_ARRAY_RETURN_NULL(char, msglen);
847
848 // Just return the FQN if error in allocating string
849 if (message == NULL) {
850 return fqn;
851 }
852
853 jio_snprintf(message, msglen, "%s%s%s%s%s%s%s",
854 class_loader_name,
855 (has_cl_name) ? delim : "",
856 (has_mod_name) ? module_name : "",
857 (has_version) ? "@" : "",
858 (has_version) ? version : "",
859 (has_cl_name || has_mod_name) ? delim : "",
860 fqn);
861 return message;
862 }