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