1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/dictionary.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "logging/log.hpp"
32 #include "memory/heapInspection.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "memory/oopFactory.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/atomic.hpp"
42 #include "runtime/orderAccess.inline.hpp"
43 #include "trace/traceMacros.hpp"
44 #include "utilities/macros.hpp"
45 #include "utilities/stack.inline.hpp"
46
47 void Klass::set_java_mirror(Handle m) {
48 assert(!m.is_null(), "New mirror should never be null.");
49 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
50 _java_mirror = class_loader_data()->add_handle(m);
51 }
52
53 oop Klass::java_mirror() const {
54 return _java_mirror.resolve();
55 }
56
57 bool Klass::is_cloneable() const {
58 return _access_flags.is_cloneable_fast() ||
59 is_subtype_of(SystemDictionary::Cloneable_klass());
60 }
61
62 void Klass::set_is_cloneable() {
63 if (name() != vmSymbols::java_lang_invoke_MemberName()) {
64 _access_flags.set_is_cloneable_fast();
65 } else {
66 assert(is_final(), "no subclasses allowed");
67 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
68 }
69 }
70
71 void Klass::set_name(Symbol* n) {
72 _name = n;
73 if (_name != NULL) _name->increment_refcount();
74 }
75
76 bool Klass::is_subclass_of(const Klass* k) const {
77 // Run up the super chain and check
78 if (this == k) return true;
79
80 Klass* t = const_cast<Klass*>(this)->super();
81
82 while (t != NULL) {
83 if (t == k) return true;
84 t = t->super();
85 }
86 return false;
87 }
88
89 bool Klass::search_secondary_supers(Klass* k) const {
90 // Put some extra logic here out-of-line, before the search proper.
91 // This cuts down the size of the inline method.
92
93 // This is necessary, since I am never in my own secondary_super list.
94 if (this == k)
95 return true;
96 // Scan the array-of-objects for a match
97 int cnt = secondary_supers()->length();
98 for (int i = 0; i < cnt; i++) {
99 if (secondary_supers()->at(i) == k) {
100 ((Klass*)this)->set_secondary_super_cache(k);
101 return true;
102 }
103 }
104 return false;
105 }
106
107 // Return self, except for abstract classes with exactly 1
108 // implementor. Then return the 1 concrete implementation.
109 Klass *Klass::up_cast_abstract() {
110 Klass *r = this;
111 while( r->is_abstract() ) { // Receiver is abstract?
112 Klass *s = r->subklass(); // Check for exactly 1 subklass
113 if( !s || s->next_sibling() ) // Oops; wrong count; give up
114 return this; // Return 'this' as a no-progress flag
115 r = s; // Loop till find concrete class
116 }
117 return r; // Return the 1 concrete class
118 }
119
120 // Find LCA in class hierarchy
121 Klass *Klass::LCA( Klass *k2 ) {
122 Klass *k1 = this;
123 while( 1 ) {
124 if( k1->is_subtype_of(k2) ) return k2;
125 if( k2->is_subtype_of(k1) ) return k1;
126 k1 = k1->super();
127 k2 = k2->super();
128 }
129 }
130
131
132 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
133 ResourceMark rm(THREAD);
134 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
135 : vmSymbols::java_lang_InstantiationException(), external_name());
136 }
137
138
139 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
140 THROW(vmSymbols::java_lang_ArrayStoreException());
141 }
142
143
144 void Klass::initialize(TRAPS) {
145 ShouldNotReachHere();
146 }
147
148 bool Klass::compute_is_subtype_of(Klass* k) {
149 assert(k->is_klass(), "argument must be a class");
150 return is_subclass_of(k);
151 }
152
153 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
154 #ifdef ASSERT
155 tty->print_cr("Error: find_field called on a klass oop."
156 " Likely error: reflection method does not correctly"
157 " wrap return value in a mirror object.");
158 #endif
159 ShouldNotReachHere();
160 return NULL;
161 }
162
163 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
164 #ifdef ASSERT
165 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
166 " Likely error: reflection method does not correctly"
167 " wrap return value in a mirror object.");
168 #endif
169 ShouldNotReachHere();
170 return NULL;
171 }
172
173 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, bool is_value, TRAPS) throw () {
174 // Pad size in case need adjust to even/odd klass ptr
175 uintptr_t addr = (uintptr_t) Metaspace::allocate(loader_data, word_size + (1 << LogKlassAlignment), MetaspaceObj::ClassType, THREAD);
176 // values are odd, otherwise make even (and vice versa)
177 if (is_value ^ (((addr & KlassPtrValueTypeMask) >> LogKlassAlignmentInBytes) != 0)) {
178 addr += (1 << LogKlassAlignmentInBytes);
179 }
180 assert(is_aligned(addr, (1 << LogKlassAlignmentInBytes)), "Klass base alignment incorrect");
181 assert( is_value || ((addr & KlassPtrValueTypeMask) == 0), "Klass even alignment incorrect");
182 assert(!is_value || ((addr & KlassPtrValueTypeMask) != 0), "Klass odd alignment incorrect");
183 return (void*) addr;
184 }
185
186 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
187 // which zeros out memory - calloc equivalent.
188 // The constructor is also used from CppVtableCloner,
189 // which doesn't zero out the memory before calling the constructor.
190 // Need to set the _java_mirror field explicitly to not hit an assert that the field
191 // should be NULL before setting it.
192 Klass::Klass() : _prototype_header(markOopDesc::prototype()),
193 _shared_class_path_index(-1),
194 _java_mirror(NULL) {
195
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, 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);
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 assert(num_extra_slots == 0, "override for complex klasses");
349 set_secondary_supers(Universe::the_empty_klass_array());
350 return NULL;
351 }
352
353
354 InstanceKlass* Klass::superklass() const {
355 assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
356 return _super == NULL ? NULL : InstanceKlass::cast(_super);
357 }
358
359 void Klass::set_subklass(Klass* s) {
360 assert(s != this, "sanity check");
361 _subklass = s;
362 }
363
364 void Klass::set_next_sibling(Klass* s) {
365 assert(s != this, "sanity check");
366 _next_sibling = s;
367 }
368
369 void Klass::append_to_sibling_list() {
370 debug_only(verify();)
371 // add ourselves to superklass' subklass list
372 InstanceKlass* super = superklass();
373 if (super == NULL) return; // special case: class Object
374 assert((!super->is_interface() // interfaces cannot be supers
375 && (super->superklass() == NULL || !is_interface())),
376 "an interface can only be a subklass of Object");
377 Klass* prev_first_subklass = super->subklass();
378 if (prev_first_subklass != NULL) {
379 // set our sibling to be the superklass' previous first subklass
380 set_next_sibling(prev_first_subklass);
381 }
382 // make ourselves the superklass' first subklass
383 super->set_subklass(this);
384 debug_only(verify();)
385 }
386
387 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
388 #ifdef ASSERT
389 // The class is alive iff the class loader is alive.
390 oop loader = class_loader();
391 bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
392 #endif // ASSERT
393
394 // The class is alive if it's mirror is alive (which should be marked if the
395 // loader is alive) unless it's an anoymous class.
396 bool mirror_alive = is_alive->do_object_b(java_mirror());
397 assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
398 " but not the other way around with anonymous classes");
399 return mirror_alive;
400 }
401
402 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
403 if (!ClassUnloading) {
404 return;
405 }
406
407 Klass* root = SystemDictionary::Object_klass();
408 Stack<Klass*, mtGC> stack;
409
410 stack.push(root);
411 while (!stack.is_empty()) {
412 Klass* current = stack.pop();
413
414 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
415
416 // Find and set the first alive subklass
417 Klass* sub = current->subklass();
418 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
419 #ifndef PRODUCT
420 if (log_is_enabled(Trace, class, unload)) {
421 ResourceMark rm;
422 log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
423 }
424 #endif
425 sub = sub->next_sibling();
426 }
427 current->set_subklass(sub);
428 if (sub != NULL) {
429 stack.push(sub);
430 }
431
432 // Find and set the first alive sibling
433 Klass* sibling = current->next_sibling();
434 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
435 if (log_is_enabled(Trace, class, unload)) {
436 ResourceMark rm;
437 log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
438 }
439 sibling = sibling->next_sibling();
440 }
441 current->set_next_sibling(sibling);
442 if (sibling != NULL) {
443 stack.push(sibling);
444 }
445
446 // Clean the implementors list and method data.
447 if (clean_alive_klasses && current->is_instance_klass()) {
448 InstanceKlass* ik = InstanceKlass::cast(current);
449 ik->clean_weak_instanceklass_links(is_alive);
450
451 // JVMTI RedefineClasses creates previous versions that are not in
452 // the class hierarchy, so process them here.
453 while ((ik = ik->previous_versions()) != NULL) {
454 ik->clean_weak_instanceklass_links(is_alive);
455 }
456 }
457 }
458 }
459
460 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
461 if (log_is_enabled(Trace, cds)) {
462 ResourceMark rm;
463 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
464 }
465
466 it->push(&_name);
467 it->push(&_secondary_super_cache);
468 it->push(&_secondary_supers);
469 for (int i = 0; i < _primary_super_limit; i++) {
470 it->push(&_primary_supers[i]);
471 }
472 it->push(&_super);
473 it->push(&_subklass);
474 it->push(&_next_sibling);
475 it->push(&_next_link);
476
477 vtableEntry* vt = start_of_vtable();
478 for (int i=0; i<vtable_length(); i++) {
479 it->push(vt[i].method_addr());
480 }
481 }
482
483 void Klass::remove_unshareable_info() {
484 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
485 TRACE_REMOVE_ID(this);
486 if (log_is_enabled(Trace, cds, unshareable)) {
487 ResourceMark rm;
488 log_trace(cds, unshareable)("remove: %s", external_name());
489 }
490
491 set_subklass(NULL);
492 set_next_sibling(NULL);
493 set_next_link(NULL);
494
495 // Null out class_loader_data because we don't share that yet.
496 set_class_loader_data(NULL);
497 set_is_shared();
498 }
499
500 void Klass::remove_java_mirror() {
501 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
502 if (log_is_enabled(Trace, cds, unshareable)) {
503 ResourceMark rm;
504 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
505 }
506 // Just null out the mirror. The class_loader_data() no longer exists.
507 _java_mirror = NULL;
508 }
509
510 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
511 assert(is_klass(), "ensure C++ vtable is restored");
512 assert(is_shared(), "must be set");
513 TRACE_RESTORE_ID(this);
514 if (log_is_enabled(Trace, cds, unshareable)) {
515 ResourceMark rm;
516 log_trace(cds, unshareable)("restore: %s", external_name());
517 }
518
519 // If an exception happened during CDS restore, some of these fields may already be
520 // set. We leave the class on the CLD list, even if incomplete so that we don't
521 // modify the CLD list outside a safepoint.
522 if (class_loader_data() == NULL) {
523 // Restore class_loader_data to the null class loader data
524 set_class_loader_data(loader_data);
525
526 // Add to null class loader list first before creating the mirror
527 // (same order as class file parsing)
528 loader_data->add_class(this);
529 }
530
531 // Recreate the class mirror.
532 // Only recreate it if not present. A previous attempt to restore may have
533 // gotten an OOM later but keep the mirror if it was created.
534 if (java_mirror() == NULL) {
535 Handle loader(THREAD, loader_data->class_loader());
536 ModuleEntry* module_entry = NULL;
537 Klass* k = this;
538 if (k->is_objArray_klass()) {
539 k = ObjArrayKlass::cast(k)->bottom_klass();
540 }
541 // Obtain klass' module.
542 if (k->is_instance_klass()) {
543 InstanceKlass* ik = (InstanceKlass*) k;
544 module_entry = ik->module();
545 } else {
546 module_entry = ModuleEntryTable::javabase_moduleEntry();
547 }
548 // Obtain java.lang.Module, if available
549 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
550 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
551 }
552 }
553
554 Klass* Klass::array_klass_or_null(int rank) {
555 EXCEPTION_MARK;
556 // No exception can be thrown by array_klass_impl when called with or_null == true.
557 // (In anycase, the execption mark will fail if it do so)
558 return array_klass_impl(true, rank, THREAD);
559 }
560
561
562 Klass* Klass::array_klass_or_null() {
563 EXCEPTION_MARK;
564 // No exception can be thrown by array_klass_impl when called with or_null == true.
565 // (In anycase, the execption mark will fail if it do so)
566 return array_klass_impl(true, THREAD);
567 }
568
569
570 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
571 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
572 return NULL;
573 }
574
575
576 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
577 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
578 return NULL;
579 }
580
581 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
582
583 // In product mode, this function doesn't have virtual function calls so
584 // there might be some performance advantage to handling InstanceKlass here.
585 const char* Klass::external_name() const {
586 if (is_instance_klass()) {
587 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
588 if (ik->is_anonymous()) {
589 char addr_buf[20];
590 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
591 size_t addr_len = strlen(addr_buf);
592 size_t name_len = name()->utf8_length();
593 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
594 name()->as_klass_external_name(result, (int) name_len + 1);
595 assert(strlen(result) == name_len, "");
596 strcpy(result + name_len, addr_buf);
597 assert(strlen(result) == name_len + addr_len, "");
598 return result;
599 }
600 }
601 if (name() == NULL) return "<unknown>";
602 return name()->as_klass_external_name();
603 }
604
605
606 const char* Klass::signature_name() const {
607 if (name() == NULL) return "<unknown>";
608 return name()->as_C_string();
609 }
610
611 // Unless overridden, modifier_flags is 0.
612 jint Klass::compute_modifier_flags(TRAPS) const {
613 return 0;
614 }
615
616 int Klass::atomic_incr_biased_lock_revocation_count() {
617 return (int) Atomic::add(1, &_biased_lock_revocation_count);
618 }
619
620 // Unless overridden, jvmti_class_status has no flags set.
621 jint Klass::jvmti_class_status() const {
622 return 0;
623 }
624
625
626 // Printing
627
628 void Klass::print_on(outputStream* st) const {
629 ResourceMark rm;
630 // print title
631 st->print("%s", internal_name());
632 print_address_on(st);
633 st->cr();
634 }
635
636 void Klass::oop_print_on(oop obj, outputStream* st) {
637 ResourceMark rm;
638 // print title
639 st->print_cr("%s ", internal_name());
640 obj->print_address_on(st);
641
642 if (WizardMode) {
643 // print header
644 obj->mark()->print_on(st);
645 }
646
647 // print class
648 st->print(" - klass: ");
649 obj->klass()->print_value_on(st);
650 st->cr();
651 }
652
653 void Klass::oop_print_value_on(oop obj, outputStream* st) {
654 // print title
655 ResourceMark rm; // Cannot print in debug mode without this
656 st->print("%s", internal_name());
657 obj->print_address_on(st);
658 }
659
660 #if INCLUDE_SERVICES
661 // Size Statistics
662 void Klass::collect_statistics(KlassSizeStats *sz) const {
663 sz->_klass_bytes = sz->count(this);
664 sz->_mirror_bytes = sz->count(java_mirror());
665 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
666
667 sz->_ro_bytes += sz->_secondary_supers_bytes;
668 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
669 }
670 #endif // INCLUDE_SERVICES
671
672 // Verification
673
674 void Klass::verify_on(outputStream* st) {
675
676 // This can be expensive, but it is worth checking that this klass is actually
677 // in the CLD graph but not in production.
678 assert(Metaspace::contains((address)this), "Should be");
679
680 guarantee(this->is_klass(),"should be klass");
681
682 if (super() != NULL) {
683 guarantee(super()->is_klass(), "should be klass");
684 }
685 if (secondary_super_cache() != NULL) {
686 Klass* ko = secondary_super_cache();
687 guarantee(ko->is_klass(), "should be klass");
688 }
689 for ( uint i = 0; i < primary_super_limit(); i++ ) {
690 Klass* ko = _primary_supers[i];
691 if (ko != NULL) {
692 guarantee(ko->is_klass(), "should be klass");
693 }
694 }
695
696 if (java_mirror() != NULL) {
697 guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
698 }
699 }
700
701 void Klass::oop_verify_on(oop obj, outputStream* st) {
702 guarantee(oopDesc::is_oop(obj), "should be oop");
703 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
704 }
705
706 klassVtable Klass::vtable() const {
707 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
708 }
709
710 vtableEntry* Klass::start_of_vtable() const {
711 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
712 }
713
714 Method* Klass::method_at_vtable(int index) {
715 #ifndef PRODUCT
716 assert(index >= 0, "valid vtable index");
717 if (DebugVtables) {
718 verify_vtable_index(index);
719 }
720 #endif
721 return start_of_vtable()[index].method();
722 }
723
724 ByteSize Klass::vtable_start_offset() {
725 return in_ByteSize(InstanceKlass::header_size() * wordSize);
726 }
727
728 #ifndef PRODUCT
729
730 bool Klass::verify_vtable_index(int i) {
731 int limit = vtable_length()/vtableEntry::size();
732 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
733 return true;
734 }
735
736 bool Klass::verify_itable_index(int i) {
737 assert(is_instance_klass(), "");
738 int method_count = klassItable::method_count_for_interface(this);
739 assert(i >= 0 && i < method_count, "index out of bounds");
740 return true;
741 }
742
743 #endif // PRODUCT
744
745 // The caller of class_loader_and_module_name() (or one of its callers)
746 // must use a ResourceMark in order to correctly free the result.
747 const char* Klass::class_loader_and_module_name() const {
748 const char* delim = "/";
749 size_t delim_len = strlen(delim);
750
751 const char* fqn = external_name();
752 // Length of message to return; always include FQN
753 size_t msglen = strlen(fqn) + 1;
754
755 bool has_cl_name = false;
756 bool has_mod_name = false;
757 bool has_version = false;
758
759 // Use class loader name, if exists and not builtin
760 const char* class_loader_name = "";
761 ClassLoaderData* cld = class_loader_data();
762 assert(cld != NULL, "class_loader_data should not be NULL");
763 if (!cld->is_builtin_class_loader_data()) {
764 // If not builtin, look for name
765 oop loader = class_loader();
766 if (loader != NULL) {
767 oop class_loader_name_oop = java_lang_ClassLoader::name(loader);
768 if (class_loader_name_oop != NULL) {
769 class_loader_name = java_lang_String::as_utf8_string(class_loader_name_oop);
770 if (class_loader_name != NULL && class_loader_name[0] != '\0') {
771 has_cl_name = true;
772 msglen += strlen(class_loader_name) + delim_len;
773 }
774 }
775 }
776 }
777
778 const char* module_name = "";
779 const char* version = "";
780 const Klass* bottom_klass = is_objArray_klass() ?
781 ObjArrayKlass::cast(this)->bottom_klass() : this;
782 if (bottom_klass->is_instance_klass()) {
783 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
784 // Use module name, if exists
785 if (module->is_named()) {
786 has_mod_name = true;
787 module_name = module->name()->as_C_string();
788 msglen += strlen(module_name);
789 // Use version if exists and is not a jdk module
790 if (module->is_non_jdk_module() && module->version() != NULL) {
791 has_version = true;
792 version = module->version()->as_C_string();
793 msglen += strlen("@") + strlen(version);
794 }
795 }
796 } else {
797 // klass is an array of primitives, so its module is java.base
798 module_name = JAVA_BASE_NAME;
799 }
800
801 if (has_cl_name || has_mod_name) {
802 msglen += delim_len;
803 }
804
805 char* message = NEW_RESOURCE_ARRAY_RETURN_NULL(char, msglen);
806
807 // Just return the FQN if error in allocating string
808 if (message == NULL) {
809 return fqn;
810 }
811
812 jio_snprintf(message, msglen, "%s%s%s%s%s%s%s",
813 class_loader_name,
814 (has_cl_name) ? delim : "",
815 (has_mod_name) ? module_name : "",
816 (has_version) ? "@" : "",
817 (has_version) ? version : "",
818 (has_cl_name || has_mod_name) ? delim : "",
819 fqn);
820 return message;
821 }