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