Mon, 07 Jul 2014 10:12:40 +0200
8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com
1 /*
2 * Copyright (c) 1997, 2014, 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 */
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/dictionary.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc_implementation/shared/markSweep.inline.hpp"
31 #include "gc_interface/collectedHeap.inline.hpp"
32 #include "memory/heapInspection.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/oopFactory.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "oops/instanceKlass.hpp"
37 #include "oops/klass.inline.hpp"
38 #include "oops/oop.inline2.hpp"
39 #include "runtime/atomic.inline.hpp"
40 #include "runtime/orderAccess.inline.hpp"
41 #include "trace/traceMacros.hpp"
42 #include "utilities/stack.hpp"
43 #include "utilities/macros.hpp"
44 #if INCLUDE_ALL_GCS
45 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
46 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
47 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
48 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
49 #endif // INCLUDE_ALL_GCS
51 void Klass::set_name(Symbol* n) {
52 _name = n;
53 if (_name != NULL) _name->increment_refcount();
54 }
56 bool Klass::is_subclass_of(const Klass* k) const {
57 // Run up the super chain and check
58 if (this == k) return true;
60 Klass* t = const_cast<Klass*>(this)->super();
62 while (t != NULL) {
63 if (t == k) return true;
64 t = t->super();
65 }
66 return false;
67 }
69 bool Klass::search_secondary_supers(Klass* k) const {
70 // Put some extra logic here out-of-line, before the search proper.
71 // This cuts down the size of the inline method.
73 // This is necessary, since I am never in my own secondary_super list.
74 if (this == k)
75 return true;
76 // Scan the array-of-objects for a match
77 int cnt = secondary_supers()->length();
78 for (int i = 0; i < cnt; i++) {
79 if (secondary_supers()->at(i) == k) {
80 ((Klass*)this)->set_secondary_super_cache(k);
81 return true;
82 }
83 }
84 return false;
85 }
87 // Return self, except for abstract classes with exactly 1
88 // implementor. Then return the 1 concrete implementation.
89 Klass *Klass::up_cast_abstract() {
90 Klass *r = this;
91 while( r->is_abstract() ) { // Receiver is abstract?
92 Klass *s = r->subklass(); // Check for exactly 1 subklass
93 if( !s || s->next_sibling() ) // Oops; wrong count; give up
94 return this; // Return 'this' as a no-progress flag
95 r = s; // Loop till find concrete class
96 }
97 return r; // Return the 1 concrete class
98 }
100 // Find LCA in class hierarchy
101 Klass *Klass::LCA( Klass *k2 ) {
102 Klass *k1 = this;
103 while( 1 ) {
104 if( k1->is_subtype_of(k2) ) return k2;
105 if( k2->is_subtype_of(k1) ) return k1;
106 k1 = k1->super();
107 k2 = k2->super();
108 }
109 }
112 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
113 ResourceMark rm(THREAD);
114 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
115 : vmSymbols::java_lang_InstantiationException(), external_name());
116 }
119 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
120 THROW(vmSymbols::java_lang_ArrayStoreException());
121 }
124 void Klass::initialize(TRAPS) {
125 ShouldNotReachHere();
126 }
128 bool Klass::compute_is_subtype_of(Klass* k) {
129 assert(k->is_klass(), "argument must be a class");
130 return is_subclass_of(k);
131 }
134 Method* Klass::uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const {
135 #ifdef ASSERT
136 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
137 " Likely error: reflection method does not correctly"
138 " wrap return value in a mirror object.");
139 #endif
140 ShouldNotReachHere();
141 return NULL;
142 }
144 void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
145 return Metaspace::allocate(loader_data, word_size, /*read_only*/false,
146 MetaspaceObj::ClassType, CHECK_NULL);
147 }
149 Klass::Klass() {
150 Klass* k = this;
152 // Preinitialize supertype information.
153 // A later call to initialize_supers() may update these settings:
154 set_super(NULL);
155 for (juint i = 0; i < Klass::primary_super_limit(); i++) {
156 _primary_supers[i] = NULL;
157 }
158 set_secondary_supers(NULL);
159 set_secondary_super_cache(NULL);
160 _primary_supers[0] = k;
161 set_super_check_offset(in_bytes(primary_supers_offset()));
163 // The constructor is used from init_self_patching_vtbl_list,
164 // which doesn't zero out the memory before calling the constructor.
165 // Need to set the field explicitly to not hit an assert that the field
166 // should be NULL before setting it.
167 _java_mirror = NULL;
169 set_modifier_flags(0);
170 set_layout_helper(Klass::_lh_neutral_value);
171 set_name(NULL);
172 AccessFlags af;
173 af.set_flags(0);
174 set_access_flags(af);
175 set_subklass(NULL);
176 set_next_sibling(NULL);
177 set_next_link(NULL);
178 TRACE_INIT_ID(this);
180 set_prototype_header(markOopDesc::prototype());
181 set_biased_lock_revocation_count(0);
182 set_last_biased_lock_bulk_revocation_time(0);
184 // The klass doesn't have any references at this point.
185 clear_modified_oops();
186 clear_accumulated_modified_oops();
187 }
189 jint Klass::array_layout_helper(BasicType etype) {
190 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
191 // Note that T_ARRAY is not allowed here.
192 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
193 int esize = type2aelembytes(etype);
194 bool isobj = (etype == T_OBJECT);
195 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
196 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
198 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
199 assert(layout_helper_is_array(lh), "correct kind");
200 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
201 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
202 assert(layout_helper_header_size(lh) == hsize, "correct decode");
203 assert(layout_helper_element_type(lh) == etype, "correct decode");
204 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
206 return lh;
207 }
209 bool Klass::can_be_primary_super_slow() const {
210 if (super() == NULL)
211 return true;
212 else if (super()->super_depth() >= primary_super_limit()-1)
213 return false;
214 else
215 return true;
216 }
218 void Klass::initialize_supers(Klass* k, TRAPS) {
219 if (FastSuperclassLimit == 0) {
220 // None of the other machinery matters.
221 set_super(k);
222 return;
223 }
224 if (k == NULL) {
225 set_super(NULL);
226 _primary_supers[0] = this;
227 assert(super_depth() == 0, "Object must already be initialized properly");
228 } else if (k != super() || k == SystemDictionary::Object_klass()) {
229 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
230 "initialize this only once to a non-trivial value");
231 set_super(k);
232 Klass* sup = k;
233 int sup_depth = sup->super_depth();
234 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
235 if (!can_be_primary_super_slow())
236 my_depth = primary_super_limit();
237 for (juint i = 0; i < my_depth; i++) {
238 _primary_supers[i] = sup->_primary_supers[i];
239 }
240 Klass* *super_check_cell;
241 if (my_depth < primary_super_limit()) {
242 _primary_supers[my_depth] = this;
243 super_check_cell = &_primary_supers[my_depth];
244 } else {
245 // Overflow of the primary_supers array forces me to be secondary.
246 super_check_cell = &_secondary_super_cache;
247 }
248 set_super_check_offset((address)super_check_cell - (address) this);
250 #ifdef ASSERT
251 {
252 juint j = super_depth();
253 assert(j == my_depth, "computed accessor gets right answer");
254 Klass* t = this;
255 while (!t->can_be_primary_super()) {
256 t = t->super();
257 j = t->super_depth();
258 }
259 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
260 assert(primary_super_of_depth(j1) == NULL, "super list padding");
261 }
262 while (t != NULL) {
263 assert(primary_super_of_depth(j) == t, "super list initialization");
264 t = t->super();
265 --j;
266 }
267 assert(j == (juint)-1, "correct depth count");
268 }
269 #endif
270 }
272 if (secondary_supers() == NULL) {
273 KlassHandle this_kh (THREAD, this);
275 // Now compute the list of secondary supertypes.
276 // Secondaries can occasionally be on the super chain,
277 // if the inline "_primary_supers" array overflows.
278 int extras = 0;
279 Klass* p;
280 for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
281 ++extras;
282 }
284 ResourceMark rm(THREAD); // need to reclaim GrowableArrays allocated below
286 // Compute the "real" non-extra secondaries.
287 GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
288 if (secondaries == NULL) {
289 // secondary_supers set by compute_secondary_supers
290 return;
291 }
293 GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
295 for (p = this_kh->super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
296 int i; // Scan for overflow primaries being duplicates of 2nd'arys
298 // This happens frequently for very deeply nested arrays: the
299 // primary superclass chain overflows into the secondary. The
300 // secondary list contains the element_klass's secondaries with
301 // an extra array dimension added. If the element_klass's
302 // secondary list already contains some primary overflows, they
303 // (with the extra level of array-ness) will collide with the
304 // normal primary superclass overflows.
305 for( i = 0; i < secondaries->length(); i++ ) {
306 if( secondaries->at(i) == p )
307 break;
308 }
309 if( i < secondaries->length() )
310 continue; // It's a dup, don't put it in
311 primaries->push(p);
312 }
313 // Combine the two arrays into a metadata object to pack the array.
314 // The primaries are added in the reverse order, then the secondaries.
315 int new_length = primaries->length() + secondaries->length();
316 Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
317 class_loader_data(), new_length, CHECK);
318 int fill_p = primaries->length();
319 for (int j = 0; j < fill_p; j++) {
320 s2->at_put(j, primaries->pop()); // add primaries in reverse order.
321 }
322 for( int j = 0; j < secondaries->length(); j++ ) {
323 s2->at_put(j+fill_p, secondaries->at(j)); // add secondaries on the end.
324 }
326 #ifdef ASSERT
327 // We must not copy any NULL placeholders left over from bootstrap.
328 for (int j = 0; j < s2->length(); j++) {
329 assert(s2->at(j) != NULL, "correct bootstrapping order");
330 }
331 #endif
333 this_kh->set_secondary_supers(s2);
334 }
335 }
337 GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
338 assert(num_extra_slots == 0, "override for complex klasses");
339 set_secondary_supers(Universe::the_empty_klass_array());
340 return NULL;
341 }
344 Klass* Klass::subklass() const {
345 return _subklass == NULL ? NULL : _subklass;
346 }
348 InstanceKlass* Klass::superklass() const {
349 assert(super() == NULL || super()->oop_is_instance(), "must be instance klass");
350 return _super == NULL ? NULL : InstanceKlass::cast(_super);
351 }
353 Klass* Klass::next_sibling() const {
354 return _next_sibling == NULL ? NULL : _next_sibling;
355 }
357 void Klass::set_subklass(Klass* s) {
358 assert(s != this, "sanity check");
359 _subklass = s;
360 }
362 void Klass::set_next_sibling(Klass* s) {
363 assert(s != this, "sanity check");
364 _next_sibling = s;
365 }
367 void Klass::append_to_sibling_list() {
368 debug_only(verify();)
369 // add ourselves to superklass' subklass list
370 InstanceKlass* super = superklass();
371 if (super == NULL) return; // special case: class Object
372 assert((!super->is_interface() // interfaces cannot be supers
373 && (super->superklass() == NULL || !is_interface())),
374 "an interface can only be a subklass of Object");
375 Klass* prev_first_subklass = super->subklass_oop();
376 if (prev_first_subklass != NULL) {
377 // set our sibling to be the superklass' previous first subklass
378 set_next_sibling(prev_first_subklass);
379 }
380 // make ourselves the superklass' first subklass
381 super->set_subklass(this);
382 debug_only(verify();)
383 }
385 bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
386 #ifdef ASSERT
387 // The class is alive iff the class loader is alive.
388 oop loader = class_loader();
389 bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
390 #endif // ASSERT
392 // The class is alive if it's mirror is alive (which should be marked if the
393 // loader is alive) unless it's an anoymous class.
394 bool mirror_alive = is_alive->do_object_b(java_mirror());
395 assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
396 " but not the other way around with anonymous classes");
397 return mirror_alive;
398 }
400 void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
401 if (!ClassUnloading) {
402 return;
403 }
405 Klass* root = SystemDictionary::Object_klass();
406 Stack<Klass*, mtGC> stack;
408 stack.push(root);
409 while (!stack.is_empty()) {
410 Klass* current = stack.pop();
412 assert(current->is_loader_alive(is_alive), "just checking, this should be live");
414 // Find and set the first alive subklass
415 Klass* sub = current->subklass_oop();
416 while (sub != NULL && !sub->is_loader_alive(is_alive)) {
417 #ifndef PRODUCT
418 if (TraceClassUnloading && WizardMode) {
419 ResourceMark rm;
420 tty->print_cr("[Unlinking class (subclass) %s]", sub->external_name());
421 }
422 #endif
423 sub = sub->next_sibling_oop();
424 }
425 current->set_subklass(sub);
426 if (sub != NULL) {
427 stack.push(sub);
428 }
430 // Find and set the first alive sibling
431 Klass* sibling = current->next_sibling_oop();
432 while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
433 if (TraceClassUnloading && WizardMode) {
434 ResourceMark rm;
435 tty->print_cr("[Unlinking class (sibling) %s]", sibling->external_name());
436 }
437 sibling = sibling->next_sibling_oop();
438 }
439 current->set_next_sibling(sibling);
440 if (sibling != NULL) {
441 stack.push(sibling);
442 }
444 // Clean the implementors list and method data.
445 if (clean_alive_klasses && current->oop_is_instance()) {
446 InstanceKlass* ik = InstanceKlass::cast(current);
447 ik->clean_implementors_list(is_alive);
448 ik->clean_method_data(is_alive);
449 }
450 }
451 }
453 void Klass::klass_update_barrier_set(oop v) {
454 record_modified_oops();
455 }
457 // This barrier is used by G1 to remember the old oop values, so
458 // that we don't forget any objects that were live at the snapshot at
459 // the beginning. This function is only used when we write oops into Klasses.
460 void Klass::klass_update_barrier_set_pre(oop* p, oop v) {
461 #if INCLUDE_ALL_GCS
462 if (UseG1GC) {
463 oop obj = *p;
464 if (obj != NULL) {
465 G1SATBCardTableModRefBS::enqueue(obj);
466 }
467 }
468 #endif
469 }
471 void Klass::klass_oop_store(oop* p, oop v) {
472 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
473 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
475 // do the store
476 if (always_do_update_barrier) {
477 klass_oop_store((volatile oop*)p, v);
478 } else {
479 klass_update_barrier_set_pre(p, v);
480 *p = v;
481 klass_update_barrier_set(v);
482 }
483 }
485 void Klass::klass_oop_store(volatile oop* p, oop v) {
486 assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
487 assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
489 klass_update_barrier_set_pre((oop*)p, v); // Cast away volatile.
490 OrderAccess::release_store_ptr(p, v);
491 klass_update_barrier_set(v);
492 }
494 void Klass::oops_do(OopClosure* cl) {
495 cl->do_oop(&_java_mirror);
496 }
498 void Klass::remove_unshareable_info() {
499 assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
501 set_subklass(NULL);
502 set_next_sibling(NULL);
503 // Clear the java mirror
504 set_java_mirror(NULL);
505 set_next_link(NULL);
507 // Null out class_loader_data because we don't share that yet.
508 set_class_loader_data(NULL);
509 }
511 void Klass::restore_unshareable_info(TRAPS) {
512 TRACE_INIT_ID(this);
513 // If an exception happened during CDS restore, some of these fields may already be
514 // set. We leave the class on the CLD list, even if incomplete so that we don't
515 // modify the CLD list outside a safepoint.
516 if (class_loader_data() == NULL) {
517 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
518 // Restore class_loader_data to the null class loader data
519 set_class_loader_data(loader_data);
521 // Add to null class loader list first before creating the mirror
522 // (same order as class file parsing)
523 loader_data->add_class(this);
524 }
526 // Recreate the class mirror. The protection_domain is always null for
527 // boot loader, for now.
528 // Only recreate it if not present. A previous attempt to restore may have
529 // gotten an OOM later but keep the mirror if it was created.
530 if (java_mirror() == NULL) {
531 java_lang_Class::create_mirror(this, Handle(NULL), CHECK);
532 }
533 }
535 Klass* Klass::array_klass_or_null(int rank) {
536 EXCEPTION_MARK;
537 // No exception can be thrown by array_klass_impl when called with or_null == true.
538 // (In anycase, the execption mark will fail if it do so)
539 return array_klass_impl(true, rank, THREAD);
540 }
543 Klass* Klass::array_klass_or_null() {
544 EXCEPTION_MARK;
545 // No exception can be thrown by array_klass_impl when called with or_null == true.
546 // (In anycase, the execption mark will fail if it do so)
547 return array_klass_impl(true, THREAD);
548 }
551 Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
552 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
553 return NULL;
554 }
557 Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
558 fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
559 return NULL;
560 }
562 oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
564 const char* Klass::external_name() const {
565 if (oop_is_instance()) {
566 InstanceKlass* ik = (InstanceKlass*) this;
567 if (ik->is_anonymous()) {
568 assert(EnableInvokeDynamic, "");
569 intptr_t hash = 0;
570 if (ik->java_mirror() != NULL) {
571 // java_mirror might not be created yet, return 0 as hash.
572 hash = ik->java_mirror()->identity_hash();
573 }
574 char hash_buf[40];
575 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
576 size_t hash_len = strlen(hash_buf);
578 size_t result_len = name()->utf8_length();
579 char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
580 name()->as_klass_external_name(result, (int) result_len + 1);
581 assert(strlen(result) == result_len, "");
582 strcpy(result + result_len, hash_buf);
583 assert(strlen(result) == result_len + hash_len, "");
584 return result;
585 }
586 }
587 if (name() == NULL) return "<unknown>";
588 return name()->as_klass_external_name();
589 }
592 const char* Klass::signature_name() const {
593 if (name() == NULL) return "<unknown>";
594 return name()->as_C_string();
595 }
597 // Unless overridden, modifier_flags is 0.
598 jint Klass::compute_modifier_flags(TRAPS) const {
599 return 0;
600 }
602 int Klass::atomic_incr_biased_lock_revocation_count() {
603 return (int) Atomic::add(1, &_biased_lock_revocation_count);
604 }
606 // Unless overridden, jvmti_class_status has no flags set.
607 jint Klass::jvmti_class_status() const {
608 return 0;
609 }
612 // Printing
614 void Klass::print_on(outputStream* st) const {
615 ResourceMark rm;
616 // print title
617 st->print("%s", internal_name());
618 print_address_on(st);
619 st->cr();
620 }
622 void Klass::oop_print_on(oop obj, outputStream* st) {
623 ResourceMark rm;
624 // print title
625 st->print_cr("%s ", internal_name());
626 obj->print_address_on(st);
628 if (WizardMode) {
629 // print header
630 obj->mark()->print_on(st);
631 }
633 // print class
634 st->print(" - klass: ");
635 obj->klass()->print_value_on(st);
636 st->cr();
637 }
639 void Klass::oop_print_value_on(oop obj, outputStream* st) {
640 // print title
641 ResourceMark rm; // Cannot print in debug mode without this
642 st->print("%s", internal_name());
643 obj->print_address_on(st);
644 }
646 #if INCLUDE_SERVICES
647 // Size Statistics
648 void Klass::collect_statistics(KlassSizeStats *sz) const {
649 sz->_klass_bytes = sz->count(this);
650 sz->_mirror_bytes = sz->count(java_mirror());
651 sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
653 sz->_ro_bytes += sz->_secondary_supers_bytes;
654 sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
655 }
656 #endif // INCLUDE_SERVICES
658 // Verification
660 void Klass::verify_on(outputStream* st) {
662 // This can be expensive, but it is worth checking that this klass is actually
663 // in the CLD graph but not in production.
664 assert(Metaspace::contains((address)this), "Should be");
666 guarantee(this->is_klass(),"should be klass");
668 if (super() != NULL) {
669 guarantee(super()->is_klass(), "should be klass");
670 }
671 if (secondary_super_cache() != NULL) {
672 Klass* ko = secondary_super_cache();
673 guarantee(ko->is_klass(), "should be klass");
674 }
675 for ( uint i = 0; i < primary_super_limit(); i++ ) {
676 Klass* ko = _primary_supers[i];
677 if (ko != NULL) {
678 guarantee(ko->is_klass(), "should be klass");
679 }
680 }
682 if (java_mirror() != NULL) {
683 guarantee(java_mirror()->is_oop(), "should be instance");
684 }
685 }
687 void Klass::oop_verify_on(oop obj, outputStream* st) {
688 guarantee(obj->is_oop(), "should be oop");
689 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
690 }
692 #ifndef PRODUCT
694 bool Klass::verify_vtable_index(int i) {
695 if (oop_is_instance()) {
696 int limit = ((InstanceKlass*)this)->vtable_length()/vtableEntry::size();
697 assert(i >= 0 && i < limit, err_msg("index %d out of bounds %d", i, limit));
698 } else {
699 assert(oop_is_array(), "Must be");
700 int limit = ((ArrayKlass*)this)->vtable_length()/vtableEntry::size();
701 assert(i >= 0 && i < limit, err_msg("index %d out of bounds %d", i, limit));
702 }
703 return true;
704 }
706 bool Klass::verify_itable_index(int i) {
707 assert(oop_is_instance(), "");
708 int method_count = klassItable::method_count_for_interface(this);
709 assert(i >= 0 && i < method_count, "index out of bounds");
710 return true;
711 }
713 #endif
715 /////////////// Unit tests ///////////////
717 #ifndef PRODUCT
719 class TestKlass {
720 public:
721 static void test_oop_is_instanceClassLoader() {
722 assert(SystemDictionary::ClassLoader_klass()->oop_is_instanceClassLoader(), "assert");
723 assert(!SystemDictionary::String_klass()->oop_is_instanceClassLoader(), "assert");
724 }
725 };
727 void TestKlass_test() {
728 TestKlass::test_oop_is_instanceClassLoader();
729 }
731 #endif