1 /*
2 * Copyright (c) 1997, 2019, 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/classLoaderDataGraph.inline.hpp"
28 #include "classfile/dictionary.hpp"
29 #include "classfile/javaClasses.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "gc/shared/collectedHeap.inline.hpp"
33 #include "logging/log.hpp"
34 #include "memory/heapInspection.hpp"
35 #include "memory/heapShared.hpp"
36 #include "memory/metadataFactory.hpp"
37 #include "memory/metaspaceClosure.hpp"
38 #include "memory/metaspaceShared.hpp"
39 #include "memory/oopFactory.hpp"
40 #include "memory/resourceArea.hpp"
41 #include "oops/compressedOops.inline.hpp"
42 #include "oops/instanceKlass.hpp"
43 #include "oops/klass.inline.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "oops/oopHandle.inline.hpp"
46 #include "runtime/atomic.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/orderAccess.hpp"
49 #include "utilities/macros.hpp"
50 #include "utilities/stack.inline.hpp"
51
52 void Klass::set_java_mirror(Handle m) {
53 assert(!m.is_null(), "New mirror should never be null.");
54 assert(_java_mirror.resolve() == NULL, "should only be used to initialize mirror");
55 _java_mirror = class_loader_data()->add_handle(m);
56 }
57
58 oop Klass::java_mirror() const {
59 return _java_mirror.resolve();
60 }
61
62 oop Klass::java_mirror_no_keepalive() const {
63 return _java_mirror.peek();
64 }
65
66 bool Klass::is_cloneable() const {
67 return _access_flags.is_cloneable_fast() ||
68 is_subtype_of(SystemDictionary::Cloneable_klass());
69 }
70
71 void Klass::set_is_cloneable() {
72 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
73 assert(is_final(), "no subclasses allowed");
74 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
75 } else if (is_instance_klass() && InstanceKlass::cast(this)->reference_type() != REF_NONE) {
76 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
77 } else {
78 _access_flags.set_is_cloneable_fast();
79 }
80 }
81
82 void Klass::set_name(Symbol* n) {
83 _name = n;
84 if (_name != NULL) _name->increment_refcount();
85 }
86
87 bool Klass::is_subclass_of(const Klass* k) const {
88 // Run up the super chain and check
89 if (this == k) return true;
90
91 Klass* t = const_cast<Klass*>(this)->super();
92
93 while (t != NULL) {
94 if (t == k) return true;
95 t = t->super();
96 }
97 return false;
98 }
99
100 bool Klass::search_secondary_supers(Klass* k) const {
101 // Put some extra logic here out-of-line, before the search proper.
102 // This cuts down the size of the inline method.
103
104 // This is necessary, since I am never in my own secondary_super list.
105 if (this == k)
106 return true;
107 // Scan the array-of-objects for a match
108 int cnt = secondary_supers()->length();
109 for (int i = 0; i < cnt; i++) {
110 if (secondary_supers()->at(i) == k) {
111 ((Klass*)this)->set_secondary_super_cache(k);
112 return true;
113 }
114 }
115 return false;
116 }
117
118 // Return self, except for abstract classes with exactly 1
119 // implementor. Then return the 1 concrete implementation.
120 Klass *Klass::up_cast_abstract() {
121 Klass *r = this;
122 while( r->is_abstract() ) { // Receiver is abstract?
123 Klass *s = r->subklass(); // Check for exactly 1 subklass
124 if (s == NULL || s->next_sibling() != NULL) // Oops; wrong count; give up
125 return this; // Return 'this' as a no-progress flag
126 r = s; // Loop till find concrete class
127 }
128 return r; // Return the 1 concrete class
129 }
130
131 // Find LCA in class hierarchy
132 Klass *Klass::LCA( Klass *k2 ) {
133 Klass *k1 = this;
134 while( 1 ) {
135 if( k1->is_subtype_of(k2) ) return k2;
136 if( k2->is_subtype_of(k1) ) return k1;
137 k1 = k1->super();
138 k2 = k2->super();
139 }
140 }
141
142
143 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
144 ResourceMark rm(THREAD);
145 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
146 : vmSymbols::java_lang_InstantiationException(), external_name());
147 }
148
149
150 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
151 ResourceMark rm(THREAD);
152 assert(s != NULL, "Throw NPE!");
153 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(),
154 err_msg("arraycopy: source type %s is not an array", s->klass()->external_name()));
155 }
156
157
158 void Klass::initialize(TRAPS) {
159 ShouldNotReachHere();
160 }
161
162 Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
163 #ifdef ASSERT
164 tty->print_cr("Error: find_field called on a klass oop."
165 " Likely error: reflection method does not correctly"
166 " wrap return value in a mirror object.");
167 #endif
168 ShouldNotReachHere();
169 return NULL;
170 }
171
172 Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature,
173 OverpassLookupMode overpass_mode,
174 PrivateLookupMode private_mode) const {
175 #ifdef ASSERT
176 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
177 " Likely error: reflection method does not correctly"
178 " wrap return value in a mirror object.");
179 #endif
180 ShouldNotReachHere();
181 return NULL;
182 }
183
184 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
185 return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
186 }
187
188 // "Normal" instantiation is preceeded by a MetaspaceObj allocation
189 // which zeros out memory - calloc equivalent.
190 // The constructor is also used from CppVtableCloner,
191 // which doesn't zero out the memory before calling the constructor.
192 // Need to set the _java_mirror field explicitly to not hit an assert that the field
193 // should be NULL before setting it.
194 Klass::Klass(KlassID id) : _id(id),
195 _java_mirror(NULL),
196 _prototype_header(markOopDesc::prototype()),
197 _shared_class_path_index(-1) {
198 CDS_ONLY(_shared_class_flags = 0;)
199 CDS_JAVA_HEAP_ONLY(_archived_mirror = 0;)
200 _primary_supers[0] = this;
201 set_super_check_offset(in_bytes(primary_supers_offset()));
202 }
203
204 jint Klass::array_layout_helper(BasicType etype) {
205 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
206 // Note that T_ARRAY is not allowed here.
207 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
208 int esize = type2aelembytes(etype);
209 bool isobj = (etype == T_OBJECT);
210 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
211 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
212
213 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
214 assert(layout_helper_is_array(lh), "correct kind");
215 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
216 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
217 assert(layout_helper_header_size(lh) == hsize, "correct decode");
218 assert(layout_helper_element_type(lh) == etype, "correct decode");
219 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
220
221 return lh;
222 }
223
224 bool Klass::can_be_primary_super_slow() const {
225 if (super() == NULL)
226 return true;
227 else if (super()->super_depth() >= primary_super_limit()-1)
228 return false;
229 else
230 return true;
231 }
232
233 void Klass::initialize_supers(Klass* k, Array<InstanceKlass*>* transitive_interfaces, TRAPS) {
234 if (k == NULL) {
235 set_super(NULL);
236 _primary_supers[0] = this;
237 assert(super_depth() == 0, "Object must already be initialized properly");
238 } else if (k != super() || k == SystemDictionary::Object_klass()) {
239 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
240 "initialize this only once to a non-trivial value");
241 set_super(k);
242 Klass* sup = k;
243 int sup_depth = sup->super_depth();
244 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
245 if (!can_be_primary_super_slow())
246 my_depth = primary_super_limit();
247 for (juint i = 0; i < my_depth; i++) {
248 _primary_supers[i] = sup->_primary_supers[i];
249 }
250 Klass* *super_check_cell;
251 if (my_depth < primary_super_limit()) {
252 _primary_supers[my_depth] = this;
253 super_check_cell = &_primary_supers[my_depth];
254 } else {
255 // Overflow of the primary_supers array forces me to be secondary.
256 super_check_cell = &_secondary_super_cache;
257 }
258 set_super_check_offset((address)super_check_cell - (address) this);
259
260 #ifdef ASSERT
261 {
262 juint j = super_depth();
263 assert(j == my_depth, "computed accessor gets right answer");
264 Klass* t = this;
265 while (!t->can_be_primary_super()) {
266 t = t->super();
267 j = t->super_depth();
268 }
269 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
270 assert(primary_super_of_depth(j1) == NULL, "super list padding");
271 }
272 while (t != NULL) {
273 assert(primary_super_of_depth(j) == t, "super list initialization");
274 t = t->super();
275 --j;
276 }
277 assert(j == (juint)-1, "correct depth count");
278 }
279 #endif
280 }
281
282 if (secondary_supers() == NULL) {
283
284 // Now compute the list of secondary supertypes.
285 // Secondaries can occasionally be on the super chain,
286 // if the inline "_primary_supers" array overflows.
287 int extras = 0;
288 Klass* p;
289 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
290 ++extras;
291 }
292
293 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
294
295 // Compute the "real" non-extra secondaries.
296 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras, transitive_interfaces);
297 if (secondaries == NULL) {
298 // secondary_supers set by compute_secondary_supers
299 return;
300 }
301
302 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
303
304 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
305 int i; // Scan for overflow primaries being duplicates of 2nd'arys
306
307 // This happens frequently for very deeply nested arrays: the
308 // primary superclass chain overflows into the secondary. The
309 // secondary list contains the element_klass's secondaries with
310 // an extra array dimension added. If the element_klass's
311 // secondary list already contains some primary overflows, they
312 // (with the extra level of array-ness) will collide with the
313 // normal primary superclass overflows.
314 for( i = 0; i < secondaries->length(); i++ ) {
315 if( secondaries->at(i) == p )
316 break;
317 }
318 if( i < secondaries->length() )
319 continue; // It's a dup, don't put it in
320 primaries->push(p);
321 }
322 // Combine the two arrays into a metadata object to pack the array.
323 // The primaries are added in the reverse order, then the secondaries.
324 int new_length = primaries->length() + secondaries->length();
325 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
326 class_loader_data(), new_length, CHECK);
327 int fill_p = primaries->length();
328 for (int j = 0; j < fill_p; j++) {
329 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
330 }
331 for( int j = 0; j < secondaries->length(); j++ ) {
332 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
333 }
334
335 #ifdef ASSERT
336 // We must not copy any NULL placeholders left over from bootstrap.
337 for (int j = 0; j < s2->length(); j++) {
338 assert(s2->at(j) != NULL, "correct bootstrapping order");
339 }
340 #endif
341
342 set_secondary_supers(s2);
343 }
344 }
345
346 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots,
347 Array<InstanceKlass*>* transitive_interfaces) {
348 assert(num_extra_slots == 0, "override for complex klasses");
349 assert(transitive_interfaces == NULL, "sanity");
350 set_secondary_supers(Universe::the_empty_klass_array());
351 return NULL;
352 }
353
354
355 // superklass links
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 // subklass links. Used by the compiler (and vtable initialization)
362 // May be cleaned concurrently, so must use the Compile_lock.
363 // The log parameter is for clean_weak_klass_links to report unlinked classes.
364 Klass* Klass::subklass(bool log) const {
365 // Need load_acquire on the _subklass, because it races with inserts that
366 // publishes freshly initialized data.
367 for (Klass* chain = OrderAccess::load_acquire(&_subklass);
368 chain != NULL;
369 // Do not need load_acquire on _next_sibling, because inserts never
370 // create _next_sibling edges to dead data.
371 chain = Atomic::load(&chain->_next_sibling))
372 {
373 if (chain->is_loader_alive()) {
374 return chain;
375 } else if (log) {
376 if (log_is_enabled(Trace, class, unload)) {
377 ResourceMark rm;
378 log_trace(class, unload)("unlinking class (subclass): %s", chain->external_name());
379 }
380 }
381 }
382 return NULL;
383 }
384
385 Klass* Klass::next_sibling(bool log) const {
386 // Do not need load_acquire on _next_sibling, because inserts never
387 // create _next_sibling edges to dead data.
388 for (Klass* chain = Atomic::load(&_next_sibling);
389 chain != NULL;
390 chain = Atomic::load(&chain->_next_sibling)) {
391 // Only return alive klass, there may be stale klass
392 // in this chain if cleaned concurrently.
393 if (chain->is_loader_alive()) {
394 return chain;
395 } else if (log) {
396 if (log_is_enabled(Trace, class, unload)) {
397 ResourceMark rm;
398 log_trace(class, unload)("unlinking class (sibling): %s", chain->external_name());
399 }
400 }
401 }
402 return NULL;
403 }
404
405 void Klass::set_subklass(Klass* s) {
406 assert(s != this, "sanity check");
407 OrderAccess::release_store(&_subklass, s);
408 }
409
410 void Klass::set_next_sibling(Klass* s) {
411 assert(s != this, "sanity check");
412 // Does not need release semantics. If used by cleanup, it will link to
413 // already safely published data, and if used by inserts, will be published
414 // safely using cmpxchg.
415 Atomic::store(s, &_next_sibling);
416 }
417
418 void Klass::append_to_sibling_list() {
419 assert_locked_or_safepoint(Compile_lock);
420 debug_only(verify();)
421 // add ourselves to superklass' subklass list
422 InstanceKlass* super = superklass();
423 if (super == NULL) return; // special case: class Object
424 assert((!super->is_interface() // interfaces cannot be supers
425 && (super->superklass() == NULL || !is_interface())),
426 "an interface can only be a subklass of Object");
427
428 // Make sure there is no stale subklass head
429 super->clean_subklass();
430
431 for (;;) {
432 Klass* prev_first_subklass = OrderAccess::load_acquire(&_super->_subklass);
433 if (prev_first_subklass != NULL) {
434 // set our sibling to be the superklass' previous first subklass
435 assert(prev_first_subklass->is_loader_alive(), "May not attach not alive klasses");
436 set_next_sibling(prev_first_subklass);
437 }
438 // Note that the prev_first_subklass is always alive, meaning no sibling_next links
439 // are ever created to not alive klasses. This is an important invariant of the lock-free
440 // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
441 if (Atomic::cmpxchg(this, &super->_subklass, prev_first_subklass) == prev_first_subklass) {
442 return;
443 }
444 }
445 debug_only(verify();)
446 }
447
448 void Klass::clean_subklass() {
449 for (;;) {
450 // Need load_acquire, due to contending with concurrent inserts
451 Klass* subklass = OrderAccess::load_acquire(&_subklass);
452 if (subklass == NULL || subklass->is_loader_alive()) {
453 return;
454 }
455 // Try to fix _subklass until it points at something not dead.
456 Atomic::cmpxchg(subklass->next_sibling(), &_subklass, subklass);
457 }
458 }
459
460 void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
461 if (!ClassUnloading || !unloading_occurred) {
462 return;
463 }
464
465 Klass* root = SystemDictionary::Object_klass();
466 Stack<Klass*, mtGC> stack;
467
468 stack.push(root);
469 while (!stack.is_empty()) {
470 Klass* current = stack.pop();
471
472 assert(current->is_loader_alive(), "just checking, this should be live");
473
474 // Find and set the first alive subklass
475 Klass* sub = current->subklass(true);
476 current->clean_subklass();
477 if (sub != NULL) {
478 stack.push(sub);
479 }
480
481 // Find and set the first alive sibling
482 Klass* sibling = current->next_sibling(true);
483 current->set_next_sibling(sibling);
484 if (sibling != NULL) {
485 stack.push(sibling);
486 }
487
488 // Clean the implementors list and method data.
489 if (clean_alive_klasses && current->is_instance_klass()) {
490 InstanceKlass* ik = InstanceKlass::cast(current);
491 ik->clean_weak_instanceklass_links();
492
493 // JVMTI RedefineClasses creates previous versions that are not in
494 // the class hierarchy, so process them here.
495 while ((ik = ik->previous_versions()) != NULL) {
496 ik->clean_weak_instanceklass_links();
497 }
498 }
499 }
500 }
501
502 void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
503 if (log_is_enabled(Trace, cds)) {
504 ResourceMark rm;
505 log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
506 }
507
508 it->push(&_name);
509 it->push(&_secondary_super_cache);
510 it->push(&_secondary_supers);
511 for (int i = 0; i < _primary_super_limit; i++) {
512 it->push(&_primary_supers[i]);
513 }
514 it->push(&_super);
515 it->push((Klass**)&_subklass);
516 it->push((Klass**)&_next_sibling);
517 it->push(&_next_link);
518
519 vtableEntry* vt = start_of_vtable();
520 for (int i=0; i<vtable_length(); i++) {
521 it->push(vt[i].method_addr());
522 }
523 }
524
525 void Klass::remove_unshareable_info() {
526 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
527 JFR_ONLY(REMOVE_ID(this);)
528 if (log_is_enabled(Trace, cds, unshareable)) {
529 ResourceMark rm;
530 log_trace(cds, unshareable)("remove: %s", external_name());
531 }
532
533 set_subklass(NULL);
534 set_next_sibling(NULL);
535 set_next_link(NULL);
536
537 // Null out class_loader_data because we don't share that yet.
538 set_class_loader_data(NULL);
539 set_is_shared();
540 }
541
542 void Klass::remove_java_mirror() {
543 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
544 if (log_is_enabled(Trace, cds, unshareable)) {
545 ResourceMark rm;
546 log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
547 }
548 // Just null out the mirror. The class_loader_data() no longer exists.
549 _java_mirror = NULL;
550 }
551
552 void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
553 assert(is_klass(), "ensure C++ vtable is restored");
554 assert(is_shared(), "must be set");
555 JFR_ONLY(RESTORE_ID(this);)
556 if (log_is_enabled(Trace, cds, unshareable)) {
557 ResourceMark rm;
558 log_trace(cds, unshareable)("restore: %s", external_name());
559 }
560
561 // If an exception happened during CDS restore, some of these fields may already be
562 // set. We leave the class on the CLD list, even if incomplete so that we don't
563 // modify the CLD list outside a safepoint.
564 if (class_loader_data() == NULL) {
565 // Restore class_loader_data to the null class loader data
566 set_class_loader_data(loader_data);
567
568 // Add to null class loader list first before creating the mirror
569 // (same order as class file parsing)
570 loader_data->add_class(this);
571 }
572
573 Handle loader(THREAD, loader_data->class_loader());
574 ModuleEntry* module_entry = NULL;
575 Klass* k = this;
576 if (k->is_objArray_klass()) {
577 k = ObjArrayKlass::cast(k)->bottom_klass();
578 }
579 // Obtain klass' module.
580 if (k->is_instance_klass()) {
581 InstanceKlass* ik = (InstanceKlass*) k;
582 module_entry = ik->module();
583 } else {
584 module_entry = ModuleEntryTable::javabase_moduleEntry();
585 }
586 // Obtain java.lang.Module, if available
587 Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
588
589 if (this->has_raw_archived_mirror()) {
590 ResourceMark rm;
591 log_debug(cds, mirror)("%s has raw archived mirror", external_name());
592 if (HeapShared::open_archive_heap_region_mapped()) {
593 bool present = java_lang_Class::restore_archived_mirror(this, loader, module_handle,
594 protection_domain,
595 CHECK);
596 if (present) {
597 return;
598 }
599 }
600
601 // No archived mirror data
602 log_debug(cds, mirror)("No archived mirror data for %s", external_name());
603 _java_mirror = NULL;
604 this->clear_has_raw_archived_mirror();
605 }
606
607 // Only recreate it if not present. A previous attempt to restore may have
608 // gotten an OOM later but keep the mirror if it was created.
609 if (java_mirror() == NULL) {
610 log_trace(cds, mirror)("Recreate mirror for %s", external_name());
611 java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
612 }
613 }
614
615 #if INCLUDE_CDS_JAVA_HEAP
616 // Used at CDS dump time to access the archived mirror. No GC barrier.
617 oop Klass::archived_java_mirror_raw() {
618 assert(has_raw_archived_mirror(), "must have raw archived mirror");
619 return CompressedOops::decode(_archived_mirror);
620 }
621
622 narrowOop Klass::archived_java_mirror_raw_narrow() {
623 assert(has_raw_archived_mirror(), "must have raw archived mirror");
624 return _archived_mirror;
625 }
626
627 // No GC barrier
628 void Klass::set_archived_java_mirror_raw(oop m) {
629 assert(DumpSharedSpaces, "called only during runtime");
630 _archived_mirror = CompressedOops::encode(m);
631 }
632 #endif // INCLUDE_CDS_JAVA_HEAP
633
634 Klass* Klass::array_klass_or_null(ArrayStorageProperties storage_props, int rank) {
635 EXCEPTION_MARK;
636 // No exception can be thrown by array_klass_impl when called with or_null == true.
637 // (In anycase, the execption mark will fail if it do so)
638 return array_klass_impl(storage_props, true, rank, THREAD);
639 }
640
641
642 Klass* Klass::array_klass_or_null(ArrayStorageProperties storage_props) {
643 EXCEPTION_MARK;
644 // No exception can be thrown by array_klass_impl when called with or_null == true.
645 // (In anycase, the execption mark will fail if it do so)
646 return array_klass_impl(storage_props, true, THREAD);
647 }
648
649
650 Klass* Klass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS) {
651 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
652 return NULL;
653 }
654
655
656 Klass* Klass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS) {
657 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
658 return NULL;
659 }
660
661 void Klass::check_array_allocation_length(int length, int max_length, TRAPS) {
662 if (length > max_length) {
663 if (!THREAD->in_retryable_allocation()) {
664 report_java_out_of_memory("Requested array size exceeds VM limit");
665 JvmtiExport::post_array_size_exhausted();
666 THROW_OOP(Universe::out_of_memory_error_array_size());
667 } else {
668 THROW_OOP(Universe::out_of_memory_error_retry());
669 }
670 } else if (length < 0) {
671 THROW_MSG(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
672 }
673 }
674
675 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
676
677 // In product mode, this function doesn't have virtual function calls so
678 // there might be some performance advantage to handling InstanceKlass here.
679 const char* Klass::external_name() const {
680 if (is_instance_klass()) {
681 const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
682 if (ik->is_unsafe_anonymous()) {
683 char addr_buf[20];
684 jio_snprintf(addr_buf, 20, "/" INTPTR_FORMAT, p2i(ik));
685 size_t addr_len = strlen(addr_buf);
686 size_t name_len = name()->utf8_length();
687 char* result = NEW_RESOURCE_ARRAY(char, name_len + addr_len + 1);
688 name()->as_klass_external_name(result, (int) name_len + 1);
689 assert(strlen(result) == name_len, "");
690 strcpy(result + name_len, addr_buf);
691 assert(strlen(result) == name_len + addr_len, "");
692 return result;
693 }
694 }
695 if (name() == NULL) return "<unknown>";
696 return name()->as_klass_external_name();
697 }
698
699 const char* Klass::signature_name() const {
700 if (name() == NULL) return "<unknown>";
701 return name()->as_C_string();
702 }
703
704 const char* Klass::external_kind() const {
705 if (is_interface()) return "interface";
706 if (is_abstract()) return "abstract class";
707 return "class";
708 }
709
710 // Unless overridden, modifier_flags is 0.
711 jint Klass::compute_modifier_flags(TRAPS) const {
712 return 0;
713 }
714
715 int Klass::atomic_incr_biased_lock_revocation_count() {
716 return (int) Atomic::add(1, &_biased_lock_revocation_count);
717 }
718
719 // Unless overridden, jvmti_class_status has no flags set.
720 jint Klass::jvmti_class_status() const {
721 return 0;
722 }
723
724
725 // Printing
726
727 void Klass::print_on(outputStream* st) const {
728 ResourceMark rm;
729 // print title
730 st->print("%s", internal_name());
731 print_address_on(st);
732 st->cr();
733 }
734
735 void Klass::oop_print_on(oop obj, outputStream* st) {
736 ResourceMark rm;
737 // print title
738 st->print_cr("%s ", internal_name());
739 obj->print_address_on(st);
740
741 if (WizardMode) {
742 // print header
743 obj->mark()->print_on(st);
744 ArrayStorageProperties props = obj->array_storage_properties();
745 if (props.value() != 0) {
746 st->print(" - array storage properties: ");
747 if (props.is_flattened()) {
748 st->print(" flat");
749 }
750 if (props.is_null_free()) {
751 st->print(" non nullable");
752 }
753 }
754 }
755
756 // print class
757 st->print(" - klass: ");
758 obj->klass()->print_value_on(st);
759 st->cr();
760 }
761
762 void Klass::oop_print_value_on(oop obj, outputStream* st) {
763 // print title
764 ResourceMark rm; // Cannot print in debug mode without this
765 st->print("%s", internal_name());
766 obj->print_address_on(st);
767 }
768
769 #if INCLUDE_SERVICES
770 // Size Statistics
771 void Klass::collect_statistics(KlassSizeStats *sz) const {
772 sz->_klass_bytes = sz->count(this);
773 sz->_mirror_bytes = sz->count(java_mirror());
774 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
775
776 sz->_ro_bytes += sz->_secondary_supers_bytes;
777 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
778 }
779 #endif // INCLUDE_SERVICES
780
781 // Verification
782
783 void Klass::verify_on(outputStream* st) {
784
785 // This can be expensive, but it is worth checking that this klass is actually
786 // in the CLD graph but not in production.
787 assert(Metaspace::contains((address)this), "Should be");
788
789 guarantee(this->is_klass(),"should be klass");
790
791 if (super() != NULL) {
792 guarantee(super()->is_klass(), "should be klass");
793 }
794 if (secondary_super_cache() != NULL) {
795 Klass* ko = secondary_super_cache();
796 guarantee(ko->is_klass(), "should be klass");
797 }
798 for ( uint i = 0; i < primary_super_limit(); i++ ) {
799 Klass* ko = _primary_supers[i];
800 if (ko != NULL) {
801 guarantee(ko->is_klass(), "should be klass");
802 }
803 }
804
805 if (java_mirror_no_keepalive() != NULL) {
806 guarantee(oopDesc::is_oop(java_mirror_no_keepalive()), "should be instance");
807 }
808 }
809
810 void Klass::oop_verify_on(oop obj, outputStream* st) {
811 guarantee(oopDesc::is_oop(obj), "should be oop");
812 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
813 }
814
815 Klass* Klass::decode_klass_raw(narrowKlass narrow_klass) {
816 return (Klass*)(void*)( (uintptr_t)Universe::narrow_klass_base() +
817 ((uintptr_t)narrow_klass << Universe::narrow_klass_shift()));
818 }
819
820 bool Klass::is_valid(Klass* k) {
821 if (!is_aligned(k, sizeof(MetaWord))) return false;
822 if ((size_t)k < os::min_page_size()) return false;
823
824 if (!os::is_readable_range(k, k + 1)) return false;
825 if (!MetaspaceUtils::is_range_in_committed(k, k + 1)) return false;
826
827 if (!Symbol::is_valid(k->name())) return false;
828 return ClassLoaderDataGraph::is_valid(k->class_loader_data());
829 }
830
831 klassVtable Klass::vtable() const {
832 return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
833 }
834
835 vtableEntry* Klass::start_of_vtable() const {
836 return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
837 }
838
839 Method* Klass::method_at_vtable(int index) {
840 #ifndef PRODUCT
841 assert(index >= 0, "valid vtable index");
842 if (DebugVtables) {
843 verify_vtable_index(index);
844 }
845 #endif
846 return start_of_vtable()[index].method();
847 }
848
849 ByteSize Klass::vtable_start_offset() {
850 return in_ByteSize(InstanceKlass::header_size() * wordSize);
851 }
852
853 #ifndef PRODUCT
854
855 bool Klass::verify_vtable_index(int i) {
856 int limit = vtable_length()/vtableEntry::size();
857 assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
858 return true;
859 }
860
861 #endif // PRODUCT
862
863 // Caller needs ResourceMark
864 // joint_in_module_of_loader provides an optimization if 2 classes are in
865 // the same module to succinctly print out relevant information about their
866 // module name and class loader's name_and_id for error messages.
867 // Format:
868 // <fully-qualified-external-class-name1> and <fully-qualified-external-class-name2>
869 // are in module <module-name>[@<version>]
870 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
871 const char* Klass::joint_in_module_of_loader(const Klass* class2, bool include_parent_loader) const {
872 assert(module() == class2->module(), "classes do not have the same module");
873 const char* class1_name = external_name();
874 size_t len = strlen(class1_name) + 1;
875
876 const char* class2_description = class2->class_in_module_of_loader(true, include_parent_loader);
877 len += strlen(class2_description);
878
879 len += strlen(" and ");
880
881 char* joint_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
882
883 // Just return the FQN if error when allocating string
884 if (joint_description == NULL) {
885 return class1_name;
886 }
887
888 jio_snprintf(joint_description, len, "%s and %s",
889 class1_name,
890 class2_description);
891
892 return joint_description;
893 }
894
895 // Caller needs ResourceMark
896 // class_in_module_of_loader provides a standard way to include
897 // relevant information about a class, such as its module name as
898 // well as its class loader's name_and_id, in error messages and logging.
899 // Format:
900 // <fully-qualified-external-class-name> is in module <module-name>[@<version>]
901 // of loader <loader-name_and_id>[, parent loader <parent-loader-name_and_id>]
902 const char* Klass::class_in_module_of_loader(bool use_are, bool include_parent_loader) const {
903 // 1. fully qualified external name of class
904 const char* klass_name = external_name();
905 size_t len = strlen(klass_name) + 1;
906
907 // 2. module name + @version
908 const char* module_name = "";
909 const char* version = "";
910 bool has_version = false;
911 bool module_is_named = false;
912 const char* module_name_phrase = "";
913 const Klass* bottom_klass = is_objArray_klass() ?
914 ObjArrayKlass::cast(this)->bottom_klass() : this;
915 if (bottom_klass->is_instance_klass()) {
916 ModuleEntry* module = InstanceKlass::cast(bottom_klass)->module();
917 if (module->is_named()) {
918 module_is_named = true;
919 module_name_phrase = "module ";
920 module_name = module->name()->as_C_string();
921 len += strlen(module_name);
922 // Use version if exists and is not a jdk module
923 if (module->should_show_version()) {
924 has_version = true;
925 version = module->version()->as_C_string();
926 // Include stlen(version) + 1 for the "@"
927 len += strlen(version) + 1;
928 }
929 } else {
930 module_name = UNNAMED_MODULE;
931 len += UNNAMED_MODULE_LEN;
932 }
933 } else {
934 // klass is an array of primitives, module is java.base
935 module_is_named = true;
936 module_name_phrase = "module ";
937 module_name = JAVA_BASE_NAME;
938 len += JAVA_BASE_NAME_LEN;
939 }
940
941 // 3. class loader's name_and_id
942 ClassLoaderData* cld = class_loader_data();
943 assert(cld != NULL, "class_loader_data should not be null");
944 const char* loader_name_and_id = cld->loader_name_and_id();
945 len += strlen(loader_name_and_id);
946
947 // 4. include parent loader information
948 const char* parent_loader_phrase = "";
949 const char* parent_loader_name_and_id = "";
950 if (include_parent_loader &&
951 !cld->is_builtin_class_loader_data()) {
952 oop parent_loader = java_lang_ClassLoader::parent(class_loader());
953 ClassLoaderData *parent_cld = ClassLoaderData::class_loader_data_or_null(parent_loader);
954 // The parent loader's ClassLoaderData could be null if it is
955 // a delegating class loader that has never defined a class.
956 // In this case the loader's name must be obtained via the parent loader's oop.
957 if (parent_cld == NULL) {
958 oop cl_name_and_id = java_lang_ClassLoader::nameAndId(parent_loader);
959 if (cl_name_and_id != NULL) {
960 parent_loader_name_and_id = java_lang_String::as_utf8_string(cl_name_and_id);
961 }
962 } else {
963 parent_loader_name_and_id = parent_cld->loader_name_and_id();
964 }
965 parent_loader_phrase = ", parent loader ";
966 len += strlen(parent_loader_phrase) + strlen(parent_loader_name_and_id);
967 }
968
969 // Start to construct final full class description string
970 len += ((use_are) ? strlen(" are in ") : strlen(" is in "));
971 len += strlen(module_name_phrase) + strlen(" of loader ");
972
973 char* class_description = NEW_RESOURCE_ARRAY_RETURN_NULL(char, len);
974
975 // Just return the FQN if error when allocating string
976 if (class_description == NULL) {
977 return klass_name;
978 }
979
980 jio_snprintf(class_description, len, "%s %s in %s%s%s%s of loader %s%s%s",
981 klass_name,
982 (use_are) ? "are" : "is",
983 module_name_phrase,
984 module_name,
985 (has_version) ? "@" : "",
986 (has_version) ? version : "",
987 loader_name_and_id,
988 parent_loader_phrase,
989 parent_loader_name_and_id);
990
991 return class_description;
992 }