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 ResourceMark rm(THREAD);
146 assert(s != NULL, "Throw NPE!");
147 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
148 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
149 }
150
151
152 void Klass::initialize(TRAPS) {
153 ShouldNotReachHere();
154 }
155
156 bool Klass::compute_is_subtype_of(Klass* k) {
157 assert(k->is_klass(), "argument must be a class");
158 return is_subclass_of(k);
159 }
160
161 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
162 #ifdef ASSERT
163 tty->print_cr("Error: find_field called on a klass oop."
164 " Likely error: reflection method does not correctly"
165 " wrap return value in a mirror object.");
166 #endif
167 ShouldNotReachHere();
168 return NULL;
169 }
170
171 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
172 #ifdef ASSERT
173 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
174 " Likely error: reflection method does not correctly"
175 " wrap return value in a mirror object.");
176 #endif
177 ShouldNotReachHere();
178 return NULL;
179 }
180
181 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
182 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
183 }
184
185 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
186 // which zeros out memory - calloc equivalent.
187 // The constructor is also used from CppVtableCloner,
188 // which doesn't zero out the memory before calling the constructor.
189 // Need to set the _java_mirror field explicitly to not hit an assert that the field
190 // should be NULL before setting it.
191 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
192 _shared_class_path_index(-1),
193 _java_mirror(NULL) {
194 CDS_ONLY(_shared_class_flags = 0;)
195 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
196 _primary_supers[0] = this;
197 set_super_check_offset(in_bytes(primary_supers_offset()));
198 }
199
200 jint Klass::array_layout_helper(BasicType etype) {
201 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
202 // Note that T_ARRAY is not allowed here.
203 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
204 int esize = type2aelembytes(etype);
205 bool isobj = (etype == T_OBJECT);
206 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
207 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
208
209 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
210 assert(layout_helper_is_array(lh), "correct kind");
211 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
212 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
213 assert(layout_helper_header_size(lh) == hsize, "correct decode");
214 assert(layout_helper_element_type(lh) == etype, "correct decode");
215 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
216
217 return lh;
218 }
219
220 bool Klass::can_be_primary_super_slow() const {
221 if (super() == NULL)
222 return true;
223 else if (super()->super_depth() >= primary_super_limit()-1)
224 return false;
225 else
226 return true;
227 }
228
229 void Klass::initialize_supers(Klass* k, Array<Klass*>* transitive_interfaces, TRAPS) {
230 if (FastSuperclassLimit == 0) {
231 // None of the other machinery matters.
232 set_super(k);
233 return;
234 }
235 if (k == NULL) {
236 set_super(NULL);
237 _primary_supers[0] = this;
238 assert(super_depth() == 0, "Object must already be initialized properly");
239 } else if (k != super() || k == SystemDictionary::Object_klass()) {
240 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
241 "initialize this only once to a non-trivial value");
242 set_super(k);
243 Klass* sup = k;
244 int sup_depth = sup->super_depth();
245 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
246 if (!can_be_primary_super_slow())
247 my_depth = primary_super_limit();
248 for (juint i = 0; i < my_depth; i++) {
249 _primary_supers[i] = sup->_primary_supers[i];
250 }
251 Klass* *super_check_cell;
252 if (my_depth < primary_super_limit()) {
253 _primary_supers[my_depth] = this;
254 super_check_cell = &_primary_supers[my_depth];
255 } else {
256 // Overflow of the primary_supers array forces me to be secondary.
257 super_check_cell = &_secondary_super_cache;
258 }
259 set_super_check_offset((address)super_check_cell - (address) this);
260
261 #ifdef ASSERT
262 {
263 juint j = super_depth();
264 assert(j == my_depth, "computed accessor gets right answer");
265 Klass* t = this;
266 while (!t->can_be_primary_super()) {
267 t = t->super();
268 j = t->super_depth();
269 }
270 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
271 assert(primary_super_of_depth(j1) == NULL, "super list padding");
272 }
273 while (t != NULL) {
274 assert(primary_super_of_depth(j) == t, "super list initialization");
275 t = t->super();
276 --j;
277 }
278 assert(j == (juint)-1, "correct depth count");
279 }
280 #endif
281 }
282
283 if (secondary_supers() == NULL) {
284
285 // Now compute the list of secondary supertypes.
286 // Secondaries can occasionally be on the super chain,
287 // if the inline "_primary_supers" array overflows.
288 int extras = 0;
289 Klass* p;
290 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
291 ++extras;
292 }
293
294 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
295
296 // Compute the "real" non-extra secondaries.
297 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
298 if (secondaries == NULL) {
299 // secondary_supers set by compute_secondary_supers
300 return;
301 }
302
303 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
304
305 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
306 int i; // Scan for overflow primaries being duplicates of 2nd'arys
307
308 // This happens frequently for very deeply nested arrays: the
309 // primary superclass chain overflows into the secondary. The
310 // secondary list contains the element_klass's secondaries with
311 // an extra array dimension added. If the element_klass's
312 // secondary list already contains some primary overflows, they
313 // (with the extra level of array-ness) will collide with the
314 // normal primary superclass overflows.
315 for( i = 0; i < secondaries->length(); i++ ) {
316 if( secondaries->at(i) == p )
317 break;
318 }
319 if( i < secondaries->length() )
320 continue; // It's a dup, don't put it in
321 primaries->push(p);
322 }
323 // Combine the two arrays into a metadata object to pack the array.
324 // The primaries are added in the reverse order, then the secondaries.
325 int new_length = primaries->length() + secondaries->length();
326 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
327 class_loader_data(), new_length, CHECK);
328 int fill_p = primaries->length();
329 for (int j = 0; j < fill_p; j++) {
330 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
331 }
332 for( int j = 0; j < secondaries->length(); j++ ) {
333 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
334 }
335
336 #ifdef ASSERT
337 // We must not copy any NULL placeholders left over from bootstrap.
338 for (int j = 0; j < s2->length(); j++) {
339 assert(s2->at(j) != NULL, "correct bootstrapping order");
340 }
341 #endif
342
343 set_secondary_supers(s2);
344 }
345 }
346
347 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
348 Array<Klass*>* transitive_interfaces) {
349 assert(num_extra_slots == 0, "override for complex klasses");
350 assert(transitive_interfaces == NULL, "sanity");
351 set_secondary_supers(Universe::the_empty_klass_array());
352 return NULL;
353 }
354
355
356 InstanceKlass* Klass::superklass() const {
357 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
358 return _super == NULL ? NULL : InstanceKlass::cast(_super);
359 }
360
361 void Klass::set_subklass(Klass* s) {
362 assert(s != this, "sanity check");
363 _subklass = s;
364 }
365
366 void Klass::set_next_sibling(Klass* s) {
367 assert(s != this, "sanity check");
368 _next_sibling = s;
369 }
370
371 void Klass::append_to_sibling_list() {
372 debug_only(verify();)
373 // add ourselves to superklass' subklass list
374 InstanceKlass* super = superklass();
375 if (super == NULL) return; // special case: class Object
376 assert((!super->is_interface() // interfaces cannot be supers
377 && (super->superklass() == NULL || !is_interface())),
378 "an interface can only be a subklass of Object");
379 Klass* prev_first_subklass = super->subklass();
380 if (prev_first_subklass != NULL) {
381 // set our sibling to be the superklass' previous first subklass
382 set_next_sibling(prev_first_subklass);
383 }
384 // make ourselves the superklass' first subklass
385 super->set_subklass(this);
386 debug_only(verify();)
387 }
388
389 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
390 if (!ClassUnloading || !unloading_occurred) {
391 return;
392 }
393
394 Klass* root = SystemDictionary::Object_klass();
395 Stack<Klass*, mtGC> stack;
396
397 stack.push(root);
398 while (!stack.is_empty()) {
399 Klass* current = stack.pop();
400
401 assert(current->is_loader_alive(), "just checking, this should be live");
402
403 // Find and set the first alive subklass
404 Klass* sub = current->subklass();
405 while (sub != NULL && !sub->is_loader_alive()) {
406 #ifndef PRODUCT
407 if (log_is_enabled(Trace, class, unload)) {
408 ResourceMark rm;
409 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
410 }
411 #endif
412 sub = sub->next_sibling();
413 }
414 current->set_subklass(sub);
415 if (sub != NULL) {
416 stack.push(sub);
417 }
418
419 // Find and set the first alive sibling
420 Klass* sibling = current->next_sibling();
421 while (sibling != NULL && !sibling->is_loader_alive()) {
422 if (log_is_enabled(Trace, class, unload)) {
423 ResourceMark rm;
424 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
425 }
426 sibling = sibling->next_sibling();
427 }
428 current->set_next_sibling(sibling);
429 if (sibling != NULL) {
430 stack.push(sibling);
431 }
432
433 // Clean the implementors list and method data.
434 if (clean_alive_klasses && current->is_instance_klass()) {
435 InstanceKlass* ik = InstanceKlass::cast(current);
436 ik->clean_weak_instanceklass_links();
437
438 // JVMTI RedefineClasses creates previous versions that are not in
439 // the class hierarchy, so process them here.
440 while ((ik = ik->previous_versions()) != NULL) {
441 ik->clean_weak_instanceklass_links();
442 }
443 }
444 }
445 }
446
447 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
448 if (log_is_enabled(Trace, cds)) {
449 ResourceMark rm;
450 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
451 }
452
453 it->push(&_name);
454 it->push(&_secondary_super_cache);
455 it->push(&_secondary_supers);
456 for (int i = 0; i < _primary_super_limit; i++) {
457 it->push(&_primary_supers[i]);
458 }
459 it->push(&_super);
460 it->push(&_subklass);
461 it->push(&_next_sibling);
462 it->push(&_next_link);
463
464 vtableEntry* vt = start_of_vtable();
465 for (int i=0; i<vtable_length(); i++) {
466 it->push(vt[i].method_addr());
467 }
468 }
469
470 void Klass::remove_unshareable_info() {
471 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
472 JFR_ONLY(REMOVE_ID(this);)
473 if (log_is_enabled(Trace, cds, unshareable)) {
474 ResourceMark rm;
475 log_trace(cds, unshareable)("remove: %s", external_name());
476 }
477
478 set_subklass(NULL);
479 set_next_sibling(NULL);
480 set_next_link(NULL);
481
482 // Null out class_loader_data because we don't share that yet.
483 set_class_loader_data(NULL);
484 set_is_shared();
485 }
486
487 void Klass::remove_java_mirror() {
488 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
489 if (log_is_enabled(Trace, cds, unshareable)) {
490 ResourceMark rm;
491 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
492 }
493 // Just null out the mirror. The class_loader_data() no longer exists.
494 _java_mirror = NULL;
495 }
496
497 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
498 assert(is_klass(), "ensure C++ vtable is restored");
499 assert(is_shared(), "must be set");
500 JFR_ONLY(RESTORE_ID(this);)
501 if (log_is_enabled(Trace, cds, unshareable)) {
502 ResourceMark rm;
503 log_trace(cds, unshareable)("restore: %s", external_name());
504 }
505
506 // If an exception happened during CDS restore, some of these fields may already be
507 // set. We leave the class on the CLD list, even if incomplete so that we don't
508 // modify the CLD list outside a safepoint.
509 if (class_loader_data() == NULL) {
510 // Restore class_loader_data to the null class loader data
511 set_class_loader_data(loader_data);
512
513 // Add to null class loader list first before creating the mirror
514 // (same order as class file parsing)
515 loader_data->add_class(this);
516 }
517
518 Handle loader(THREAD, loader_data->class_loader());
519 ModuleEntry* module_entry = NULL;
520 Klass* k = this;
521 if (k->is_objArray_klass()) {
522 k = ObjArrayKlass::cast(k)->bottom_klass();
523 }
524 // Obtain klass' module.
525 if (k->is_instance_klass()) {
526 InstanceKlass* ik = (InstanceKlass*) k;
527 module_entry = ik->module();
528 } else {
529 module_entry = ModuleEntryTable::javabase_moduleEntry();
530 }
531 // Obtain java.lang.Module, if available
532 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
533
534 if (this->has_raw_archived_mirror()) {
535 ResourceMark rm;
536 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
537 if (MetaspaceShared::open_archive_heap_region_mapped()) {
538 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
539 protection_domain,
540 CHECK);
541 if (present) {
542 return;
543 }
544 }
545
546 // No archived mirror data
547 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
548 _java_mirror = NULL;
549 this->clear_has_raw_archived_mirror();
550 }
551
552 // Only recreate it if not present. A previous attempt to restore may have
553 // gotten an OOM later but keep the mirror if it was created.
554 if (java_mirror() == NULL) {
555 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
556 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
557 }
558 }
559
560 #if INCLUDE_CDS_JAVA_HEAP
561 // Used at CDS dump time to access the archived mirror. No GC barrier.
562 oop Klass::archived_java_mirror_raw() {
563 assert(has_raw_archived_mirror(), "must have raw archived mirror");
564 return CompressedOops::decode(_archived_mirror);
565 }
566
567 // No GC barrier
568 void Klass::set_archived_java_mirror_raw(oop m) {
569 assert(DumpSharedSpaces, "called only during runtime");
570 _archived_mirror = CompressedOops::encode(m);
571 }
572 #endif // INCLUDE_CDS_JAVA_HEAP
573
574 Klass* Klass::array_klass_or_null(int rank) {
575 EXCEPTION_MARK;
576 // No exception can be thrown by array_klass_impl when called with or_null == true.
577 // (In anycase, the execption mark will fail if it do so)
578 return array_klass_impl(true, rank, THREAD);
579 }
580
581
582 Klass* Klass::array_klass_or_null() {
583 EXCEPTION_MARK;
584 // No exception can be thrown by array_klass_impl when called with or_null == true.
585 // (In anycase, the execption mark will fail if it do so)
586 return array_klass_impl(true, THREAD);
587 }
588
589
590 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
591 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
592 return NULL;
593 }
594
595
596 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
597 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
598 return NULL;
599 }
600
601 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
602
603 // In product mode, this function doesn't have virtual function calls so
604 // there might be some performance advantage to handling InstanceKlass here.
605 const char* Klass::external_name() const {
606 if (is_instance_klass()) {
607 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
608 if (ik->is_anonymous()) {
609 char addr_buf[20];
610 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
611 size_t addr_len = strlen(addr_buf);
612 size_t name_len = name()->utf8_length();
613 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
614 name()->as_klass_external_name(result, (int) name_len + 1);
615 assert(strlen(result) == name_len, "");
616 strcpy(result + name_len, addr_buf);
617 assert(strlen(result) == name_len + addr_len, "");
618 return result;
619 }
620 }
621 if (name() == NULL) return "<unknown>";
622 return name()->as_klass_external_name();
623 }
624
625 const char* Klass::signature_name() const {
626 if (name() == NULL) return "<unknown>";
627 return name()->as_C_string();
628 }
629
630 const char* Klass::external_kind() const {
631 if (is_interface()) return "interface";
632 if (is_abstract()) return "abstract class";
633 return "class";
634 }
635
636 // Unless overridden, modifier_flags is 0.
637 jint Klass::compute_modifier_flags(TRAPS) const {
638 return 0;
639 }
640
641 int Klass::atomic_incr_biased_lock_revocation_count() {
642 return (int) Atomic::add(1, &_biased_lock_revocation_count);
643 }
644
645 // Unless overridden, jvmti_class_status has no flags set.
646 jint Klass::jvmti_class_status() const {
647 return 0;
648 }
649
650
651 // Printing
652
653 void Klass::print_on(outputStream* st) const {
654 ResourceMark rm;
655 // print title
656 st->print("%s", internal_name());
657 print_address_on(st);
658 st->cr();
659 }
660
661 void Klass::oop_print_on(oop obj, outputStream* st) {
662 ResourceMark rm;
663 // print title
664 st->print_cr("%s ", internal_name());
665 obj->print_address_on(st);
666
667 if (WizardMode) {
668 // print header
669 obj->mark()->print_on(st);
670 }
671
672 // print class
673 st->print(" - klass: ");
674 obj->klass()->print_value_on(st);
675 st->cr();
676 }
677
678 void Klass::oop_print_value_on(oop obj, outputStream* st) {
679 // print title
680 ResourceMark rm; // Cannot print in debug mode without this
681 st->print("%s", internal_name());
682 obj->print_address_on(st);
683 }
684
685 #if INCLUDE_SERVICES
686 // Size Statistics
687 void Klass::collect_statistics(KlassSizeStats *sz) const {
688 sz->_klass_bytes = sz->count(this);
689 sz->_mirror_bytes = sz->count(java_mirror());
690 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
691
692 sz->_ro_bytes += sz->_secondary_supers_bytes;
693 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
694 }
695 #endif // INCLUDE_SERVICES
696
697 // Verification
698
699 void Klass::verify_on(outputStream* st) {
700
701 // This can be expensive, but it is worth checking that this klass is actually
702 // in the CLD graph but not in production.
703 assert(Metaspace::contains((address)this), "Should be");
704
705 guarantee(this->is_klass(),"should be klass");
706
707 if (super() != NULL) {
708 guarantee(super()->is_klass(), "should be klass");
709 }
710 if (secondary_super_cache() != NULL) {
711 Klass* ko = secondary_super_cache();
712 guarantee(ko->is_klass(), "should be klass");
713 }
714 for ( uint i = 0; i < primary_super_limit(); i++ ) {
715 Klass* ko = _primary_supers[i];
716 if (ko != NULL) {
717 guarantee(ko->is_klass(), "should be klass");
718 }
719 }
720
721 if (java_mirror() != NULL) {
722 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
723 }
724 }
725
726 void Klass::oop_verify_on(oop obj, outputStream* st) {
727 guarantee(oopDesc::is_oop(obj), "should be oop");
728 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
729 }
730
731 klassVtable Klass::vtable() const {
732 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
733 }
734
735 vtableEntry* Klass::start_of_vtable() const {
736 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
737 }
738
739 Method* Klass::method_at_vtable(int index) {
740 #ifndef PRODUCT
741 assert(index >= 0, "valid vtable index");
742 if (DebugVtables) {
743 verify_vtable_index(index);
744 }
745 #endif
746 return start_of_vtable()[index].method();
747 }
748
749 ByteSize Klass::vtable_start_offset() {
750 return in_ByteSize(InstanceKlass::header_size() * wordSize);
751 }
752
753 #ifndef PRODUCT
754
755 bool Klass::verify_vtable_index(int i) {
756 int limit = vtable_length()/vtableEntry::size();
757 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
758 return true;
759 }
760
761 bool Klass::verify_itable_index(int i) {
762 assert(is_instance_klass(), "");
763 int method_count = klassItable::method_count_for_interface(this);
764 assert(i >= 0 && i < method_count, "index out of bounds");
765 return true;
766 }
767
768 #endif // PRODUCT
769
770 // Caller needs ResourceMark
771 // joint_in_module_of_loader provides an optimization if 2 classes are in
772 // the same module to succinctly print out relevant information about their
773 // module name and class loader's name_and_id for error messages.
774 // Format:
775 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
776 // are in module <module-name>[@<version>]
777 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
778 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
779 assert(module() == class2->module(), "classes do not have the same module");
780 const char* class1_name = external_name();
781 size_t len = strlen(class1_name) + 1;
782
783 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
784 len += strlen(class2_description);
785
786 len += strlen(" and ");
787
788 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
789
790 // Just return the FQN if error when allocating string
791 if (joint_description == NULL) {
792 return class1_name;
793 }
794
795 jio_snprintf(joint_description, len, "%s and %s",
796 class1_name,
797 class2_description);
798
799 return joint_description;
800 }
801
802 // Caller needs ResourceMark
803 // class_in_module_of_loader provides a standard way to include
804 // relevant information about a class, such as its module name as
805 // well as its class loader's name_and_id, in error messages and logging.
806 // Format:
807 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
808 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
809 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
810 // 1. fully qualified external name of class
811 const char* klass_name = external_name();
812 size_t len = strlen(klass_name) + 1;
813
814 // 2. module name + @version
815 const char* module_name = "";
816 const char* version = "";
817 bool has_version = false;
818 bool module_is_named = false;
819 const char* module_name_phrase = "";
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 if (module->is_named()) {
825 module_is_named = true;
826 module_name_phrase = "module ";
827 module_name = module->name()->as_C_string();
828 len += strlen(module_name);
829 // Use version if exists and is not a jdk module
830 if (module->should_show_version()) {
831 has_version = true;
832 version = module->version()->as_C_string();
833 // Include stlen(version) + 1 for the "@"
834 len += strlen(version) + 1;
835 }
836 } else {
837 module_name = UNNAMED_MODULE;
838 len += UNNAMED_MODULE_LEN;
839 }
840 } else {
841 // klass is an array of primitives, module is java.base
842 module_is_named = true;
843 module_name_phrase = "module ";
844 module_name = JAVA_BASE_NAME;
845 len += JAVA_BASE_NAME_LEN;
846 }
847
848 // 3. class loader's name_and_id
849 ClassLoaderData* cld = class_loader_data();
850 assert(cld != NULL, "class_loader_data should not be null");
851 const char* loader_name_and_id = cld->loader_name_and_id();
852 len += strlen(loader_name_and_id);
853
854 // 4. include parent loader information
855 const char* parent_loader_phrase = "";
856 const char* parent_loader_name_and_id = "";
857 if (include_parent_loader &&
858 !cld->is_builtin_class_loader_data()) {
859 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
860 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data(parent_loader);
861 assert(parent_cld != NULL, "parent's class loader data should not be null");
862 parent_loader_name_and_id = parent_cld->loader_name_and_id();
863 parent_loader_phrase = ", parent loader ";
864 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
865 }
866
867 // Start to construct final full class description string
868 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
869 len += strlen(module_name_phrase) + strlen(" of loader ");
870
871 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
872
873 // Just return the FQN if error when allocating string
874 if (class_description == NULL) {
875 return klass_name;
876 }
877
878 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
879 klass_name,
880 (use_are) ? "are" : "is",
881 module_name_phrase,
882 module_name,
883 (has_version) ? "@" : "",
884 (has_version) ? version : "",
885 loader_name_and_id,
886 parent_loader_phrase,
887 parent_loader_name_and_id);
888
889 return class_description;
890 }