1 /*
2 * Copyright (c) 1997, 2026, 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 "cds/aotClassInitializer.hpp"
26 #include "cds/aotLinkedClassBulkLoader.hpp"
27 #include "cds/aotMetaspace.hpp"
28 #include "cds/archiveUtils.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/cdsEnumKlass.hpp"
31 #include "cds/classListWriter.hpp"
32 #include "cds/heapShared.hpp"
33 #include "classfile/classFileParser.hpp"
34 #include "classfile/classFileStream.hpp"
35 #include "classfile/classLoader.hpp"
36 #include "classfile/classLoaderData.inline.hpp"
37 #include "classfile/javaClasses.hpp"
38 #include "classfile/moduleEntry.hpp"
39 #include "classfile/systemDictionary.hpp"
40 #include "classfile/systemDictionaryShared.hpp"
41 #include "classfile/verifier.hpp"
42 #include "classfile/vmClasses.hpp"
43 #include "classfile/vmSymbols.hpp"
44 #include "code/codeCache.hpp"
45 #include "code/dependencyContext.hpp"
46 #include "compiler/compilationPolicy.hpp"
47 #include "compiler/compileBroker.hpp"
48 #include "gc/shared/collectedHeap.inline.hpp"
49 #include "interpreter/bytecodeStream.hpp"
50 #include "interpreter/oopMapCache.hpp"
51 #include "interpreter/rewriter.hpp"
52 #include "jvm.h"
53 #include "jvmtifiles/jvmti.h"
54 #include "klass.inline.hpp"
55 #include "logging/log.hpp"
56 #include "logging/logMessage.hpp"
57 #include "logging/logStream.hpp"
58 #include "memory/allocation.inline.hpp"
59 #include "memory/iterator.inline.hpp"
60 #include "memory/metadataFactory.hpp"
61 #include "memory/metaspaceClosure.hpp"
62 #include "memory/oopFactory.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/fieldStreams.inline.hpp"
67 #include "oops/inlineKlass.hpp"
68 #include "oops/instanceClassLoaderKlass.hpp"
69 #include "oops/instanceKlass.inline.hpp"
70 #include "oops/instanceMirrorKlass.hpp"
71 #include "oops/instanceOop.hpp"
72 #include "oops/instanceStackChunkKlass.hpp"
73 #include "oops/klass.inline.hpp"
74 #include "oops/layoutKind.hpp"
75 #include "oops/markWord.hpp"
76 #include "oops/method.hpp"
77 #include "oops/oop.inline.hpp"
78 #include "oops/recordComponent.hpp"
79 #include "oops/refArrayKlass.hpp"
80 #include "oops/symbol.hpp"
81 #include "prims/jvmtiExport.hpp"
82 #include "prims/jvmtiRedefineClasses.hpp"
83 #include "prims/jvmtiThreadState.hpp"
84 #include "prims/methodComparator.hpp"
85 #include "runtime/arguments.hpp"
86 #include "runtime/atomicAccess.hpp"
87 #include "runtime/deoptimization.hpp"
88 #include "runtime/fieldDescriptor.inline.hpp"
89 #include "runtime/handles.inline.hpp"
90 #include "runtime/javaCalls.hpp"
91 #include "runtime/javaThread.inline.hpp"
92 #include "runtime/mutexLocker.hpp"
93 #include "runtime/orderAccess.hpp"
94 #include "runtime/os.inline.hpp"
95 #include "runtime/reflection.hpp"
96 #include "runtime/synchronizer.hpp"
97 #include "runtime/threads.hpp"
98 #include "services/classLoadingService.hpp"
99 #include "services/finalizerService.hpp"
100 #include "services/threadService.hpp"
101 #include "utilities/dtrace.hpp"
102 #include "utilities/events.hpp"
103 #include "utilities/macros.hpp"
104 #include "utilities/nativeStackPrinter.hpp"
105 #include "utilities/ostream.hpp"
106 #include "utilities/stringUtils.hpp"
107 #ifdef COMPILER1
108 #include "c1/c1_Compiler.hpp"
109 #endif
110 #if INCLUDE_JFR
111 #include "jfr/jfrEvents.hpp"
112 #endif
113
114 #ifdef DTRACE_ENABLED
115
116
117 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
118 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
119 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
120 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
121 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
122 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
123 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
124 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
125 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
126 { \
127 char* data = nullptr; \
128 int len = 0; \
129 Symbol* clss_name = name(); \
130 if (clss_name != nullptr) { \
131 data = (char*)clss_name->bytes(); \
132 len = clss_name->utf8_length(); \
133 } \
134 HOTSPOT_CLASS_INITIALIZATION_##type( \
135 data, len, (void*)class_loader(), thread_type); \
136 }
137
138 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
139 { \
140 char* data = nullptr; \
141 int len = 0; \
142 Symbol* clss_name = name(); \
143 if (clss_name != nullptr) { \
144 data = (char*)clss_name->bytes(); \
145 len = clss_name->utf8_length(); \
146 } \
147 HOTSPOT_CLASS_INITIALIZATION_##type( \
148 data, len, (void*)class_loader(), thread_type, wait); \
149 }
150
151 #else // ndef DTRACE_ENABLED
152
153 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
154 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
155
156 #endif // ndef DTRACE_ENABLED
157
158 void InlineLayoutInfo::metaspace_pointers_do(MetaspaceClosure* it) {
159 log_trace(cds)("Iter(InlineFieldInfo): %p", this);
160 it->push(&_klass);
161 }
162
163 void InlineLayoutInfo::print() const {
164 print_on(tty);
165 }
166
167 void InlineLayoutInfo::print_on(outputStream* st) const {
168 st->print_cr("_klass: " PTR_FORMAT, p2i(_klass));
169 if (_klass != nullptr) {
170 StreamIndentor si(st);
171 _klass->print_on(st);
172 st->cr();
173 }
174
175 st->print("_layout: ");
176 LayoutKindHelper::print_on(_kind, st);
177 st->cr();
178
179 st->print("_null_marker_offset: %d", _null_marker_offset);
180 }
181
182 // A value class is considered naturally atomic if its layout,
183 // once all fields flattening have been applied, contains a single primitive
184 // or oop field. Because primitive types and oops are already handled
185 // atomically by the JVM, it means that there's no need to take
186 // special precautions when reading or writing this value to guarantee
187 // cross-fields invariants. Nullability has to be taken into consideration,
188 // as the null-marker has to be considered as a pseudo-field which must
189 // be kept consistent with the payload. The only kind of value class
190 // that can be considered naturally atomic when nullable is the empty
191 // value classes because the dummy field is re-used as a null-marker.
192 bool InstanceKlass::is_naturally_atomic(bool null_free) const {
193 assert(!is_identity_class(), "Doesn't make sense for an identity class");
194 if (null_free) {
195 // No extra null-marker, just check the layout of the fields
196 return _misc_flags.is_naturally_atomic();
197 } else {
198 // Requires a null-marker, can't have any other fields
199 return InlineKlass::cast(this)->is_empty_inline_type();
200 }
201 }
202
203 bool InstanceKlass::_finalization_enabled = true;
204 static int call_class_initializer_counter = 0; // for debugging
205
206 static inline bool is_class_loader(const Symbol* class_name,
207 const ClassFileParser& parser) {
208 assert(class_name != nullptr, "invariant");
209
210 if (class_name == vmSymbols::java_lang_ClassLoader()) {
211 return true;
212 }
213
214 if (vmClasses::ClassLoader_klass_is_loaded()) {
215 const Klass* const super_klass = parser.super_klass();
216 if (super_klass != nullptr) {
217 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
218 return true;
219 }
220 }
221 }
222 return false;
223 }
224
225 bool InstanceKlass::field_is_null_free_inline_type(int index) const {
226 return field(index).field_flags().is_null_free_inline_type();
227 }
228
229 bool InstanceKlass::is_class_in_loadable_descriptors_attribute(Symbol* name) const {
230 if (_loadable_descriptors == nullptr) return false;
231 for (int i = 0; i < _loadable_descriptors->length(); i++) {
232 Symbol* class_name = _constants->symbol_at(_loadable_descriptors->at(i));
233 if (class_name == name) return true;
234 }
235 return false;
236 }
237
238 static inline bool is_stack_chunk_class(const Symbol* class_name,
239 const ClassLoaderData* loader_data) {
240 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
241 loader_data->is_the_null_class_loader_data());
242 }
243
244 // private: called to verify that k is a static member of this nest.
245 // We know that k is an instance class in the same package and hence the
246 // same classloader.
247 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
248 assert(!is_hidden(), "unexpected hidden class");
249 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
250 if (log_is_enabled(Trace, class, nestmates)) {
251 ResourceMark rm(current);
252 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
253 k->external_name(), this->external_name());
254 }
255 return false;
256 }
257
258 if (log_is_enabled(Trace, class, nestmates)) {
259 ResourceMark rm(current);
260 log_trace(class, nestmates)("Checking nest membership of %s in %s",
261 k->external_name(), this->external_name());
262 }
263
264 // Check for the named class in _nest_members.
265 // We don't resolve, or load, any classes.
266 for (int i = 0; i < _nest_members->length(); i++) {
267 int cp_index = _nest_members->at(i);
268 Symbol* name = _constants->klass_name_at(cp_index);
269 if (name == k->name()) {
270 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
271 return true;
272 }
273 }
274 log_trace(class, nestmates)("- class is NOT a nest member!");
275 return false;
276 }
277
278 // Called to verify that k is a permitted subclass of this class.
279 // The incoming stringStream is used to format the messages for error logging and for the caller
280 // to use for exception throwing.
281 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
282 Thread* current = Thread::current();
283 assert(k != nullptr, "sanity check");
284 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
285 "unexpected empty _permitted_subclasses array");
286
287 if (log_is_enabled(Trace, class, sealed)) {
288 ResourceMark rm(current);
289 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
290 k->external_name(), this->external_name());
291 }
292
293 // Check that the class and its super are in the same module.
294 if (k->module() != this->module()) {
295 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
296 "and sealed class %s is in module '%s' with loader %s",
297 k->external_name(),
298 k->module()->name_as_C_string(),
299 k->module()->loader_data()->loader_name_and_id(),
300 this->external_name(),
301 this->module()->name_as_C_string(),
302 this->module()->loader_data()->loader_name_and_id());
303 log_trace(class, sealed)(" - %s", ss.as_string());
304 return false;
305 }
306
307 if (!k->is_public() && !is_same_class_package(k)) {
308 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
309 "and sealed class %s is in package '%s' with classloader %s",
310 k->external_name(),
311 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
312 k->module()->loader_data()->loader_name_and_id(),
313 this->external_name(),
314 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
315 this->module()->loader_data()->loader_name_and_id());
316 log_trace(class, sealed)(" - %s", ss.as_string());
317 return false;
318 }
319
320 for (int i = 0; i < _permitted_subclasses->length(); i++) {
321 int cp_index = _permitted_subclasses->at(i);
322 Symbol* name = _constants->klass_name_at(cp_index);
323 if (name == k->name()) {
324 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
325 return true;
326 }
327 }
328
329 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
330 k->external_name(), this->external_name());
331 log_trace(class, sealed)(" - %s", ss.as_string());
332 return false;
333 }
334
335 // Return nest-host class, resolving, validating and saving it if needed.
336 // In cases where this is called from a thread that cannot do classloading
337 // (such as a native JIT thread) then we simply return null, which in turn
338 // causes the access check to return false. Such code will retry the access
339 // from a more suitable environment later. Otherwise the _nest_host is always
340 // set once this method returns.
341 // Any errors from nest-host resolution must be preserved so they can be queried
342 // from higher-level access checking code, and reported as part of access checking
343 // exceptions.
344 // VirtualMachineErrors are propagated with a null return.
345 // Under any conditions where the _nest_host can be set to non-null the resulting
346 // value of it and, if applicable, the nest host resolution/validation error,
347 // are idempotent.
348 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
349 InstanceKlass* nest_host_k = _nest_host;
350 if (nest_host_k != nullptr) {
351 return nest_host_k;
352 }
353
354 ResourceMark rm(THREAD);
355
356 // need to resolve and save our nest-host class.
357 if (_nest_host_index != 0) { // we have a real nest_host
358 // Before trying to resolve check if we're in a suitable context
359 bool can_resolve = THREAD->can_call_java();
360 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
361 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
362 this->external_name());
363 return nullptr; // sentinel to say "try again from a different context"
364 }
365
366 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
367 this->external_name(),
368 _constants->klass_name_at(_nest_host_index)->as_C_string());
369
370 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
371 if (HAS_PENDING_EXCEPTION) {
372 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
373 return nullptr; // propagate VMEs
374 }
375 stringStream ss;
376 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
377 ss.print("Nest host resolution of %s with host %s failed: ",
378 this->external_name(), target_host_class);
379 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
380 constantPoolHandle cph(THREAD, constants());
381 SystemDictionary::add_nest_host_error(cph, _nest_host_index, ss);
382 CLEAR_PENDING_EXCEPTION;
383
384 log_trace(class, nestmates)("%s", ss.base());
385 } else {
386 // A valid nest-host is an instance class in the current package that lists this
387 // class as a nest member. If any of these conditions are not met the class is
388 // its own nest-host.
389 const char* error = nullptr;
390
391 // JVMS 5.4.4 indicates package check comes first
392 if (is_same_class_package(k)) {
393 // Now check actual membership. We can't be a member if our "host" is
394 // not an instance class.
395 if (k->is_instance_klass()) {
396 nest_host_k = InstanceKlass::cast(k);
397 bool is_member = nest_host_k->has_nest_member(THREAD, this);
398 if (is_member) {
399 _nest_host = nest_host_k; // save resolved nest-host value
400
401 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
402 this->external_name(), k->external_name());
403 return nest_host_k;
404 } else {
405 error = "current type is not listed as a nest member";
406 }
407 } else {
408 error = "host is not an instance class";
409 }
410 } else {
411 error = "types are in different packages";
412 }
413
414 // something went wrong, so record what and log it
415 {
416 stringStream ss;
417 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
418 this->external_name(),
419 this->class_loader_data()->loader_name_and_id(),
420 k->external_name(),
421 k->class_loader_data()->loader_name_and_id(),
422 error);
423 constantPoolHandle cph(THREAD, constants());
424 SystemDictionary::add_nest_host_error(cph, _nest_host_index, ss);
425 log_trace(class, nestmates)("%s", ss.base());
426 }
427 }
428 } else {
429 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
430 this->external_name());
431 }
432
433 // Either not in an explicit nest, or else an error occurred, so
434 // the nest-host is set to `this`. Any thread that sees this assignment
435 // will also see any setting of nest_host_error(), if applicable.
436 return (_nest_host = this);
437 }
438
439 // Dynamic nest member support: set this class's nest host to the given class.
440 // This occurs as part of the class definition, as soon as the instanceKlass
441 // has been created and doesn't require further resolution. The code:
442 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
443 // results in:
444 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
445 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
446 // We also know the "host" is a valid nest-host in the same package so we can
447 // assert some of those facts.
448 void InstanceKlass::set_nest_host(InstanceKlass* host) {
449 assert(is_hidden(), "must be a hidden class");
450 assert(host != nullptr, "null nest host specified");
451 assert(_nest_host == nullptr, "current class has resolved nest-host");
452 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
453 nest_host_error());
454 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
455 (host->_nest_host == host), "proposed host is not a valid nest-host");
456 // Can't assert this as package is not set yet:
457 // assert(is_same_class_package(host), "proposed host is in wrong package");
458
459 if (log_is_enabled(Trace, class, nestmates)) {
460 ResourceMark rm;
461 const char* msg = "";
462 // a hidden class does not expect a statically defined nest-host
463 if (_nest_host_index > 0) {
464 msg = "(the NestHost attribute in the current class is ignored)";
465 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
466 msg = "(the NestMembers attribute in the current class is ignored)";
467 }
468 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
469 this->external_name(),
470 host->external_name(),
471 msg);
472 }
473 // set dynamic nest host
474 _nest_host = host;
475 // Record dependency to keep nest host from being unloaded before this class.
476 ClassLoaderData* this_key = class_loader_data();
477 assert(this_key != nullptr, "sanity");
478 this_key->record_dependency(host);
479 }
480
481 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
482 // or we are k's nest_host - all of which is covered by comparing the two
483 // resolved_nest_hosts.
484 // Any exceptions (i.e. VMEs) are propagated.
485 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
486
487 assert(this != k, "this should be handled by higher-level code");
488
489 // Per JVMS 5.4.4 we first resolve and validate the current class, then
490 // the target class k.
491
492 InstanceKlass* cur_host = nest_host(CHECK_false);
493 if (cur_host == nullptr) {
494 return false;
495 }
496
497 Klass* k_nest_host = k->nest_host(CHECK_false);
498 if (k_nest_host == nullptr) {
499 return false;
500 }
501
502 bool access = (cur_host == k_nest_host);
503
504 ResourceMark rm(THREAD);
505 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
506 this->external_name(),
507 access ? "" : "NOT ",
508 k->external_name());
509 return access;
510 }
511
512 const char* InstanceKlass::nest_host_error() {
513 if (_nest_host_index == 0) {
514 return nullptr;
515 } else {
516 constantPoolHandle cph(Thread::current(), constants());
517 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
518 }
519 }
520
521 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
522 const int size = InstanceKlass::size(parser.vtable_size(),
523 parser.itable_size(),
524 nonstatic_oop_map_size(parser.total_oop_map_count()),
525 parser.is_interface(),
526 parser.is_inline_type());
527
528 const Symbol* const class_name = parser.class_name();
529 assert(class_name != nullptr, "invariant");
530 ClassLoaderData* loader_data = parser.loader_data();
531 assert(loader_data != nullptr, "invariant");
532
533 InstanceKlass* ik;
534
535 // Allocation
536 if (parser.is_instance_ref_klass()) {
537 // java.lang.ref.Reference
538 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
539 } else if (class_name == vmSymbols::java_lang_Class()) {
540 // mirror - java.lang.Class
541 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
542 } else if (is_stack_chunk_class(class_name, loader_data)) {
543 // stack chunk
544 ik = new (loader_data, size, THREAD) InstanceStackChunkKlass(parser);
545 } else if (is_class_loader(class_name, parser)) {
546 // class loader - java.lang.ClassLoader
547 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
548 } else if (parser.is_inline_type()) {
549 // inline type
550 ik = new (loader_data, size, THREAD) InlineKlass(parser);
551 } else {
552 // normal
553 ik = new (loader_data, size, THREAD) InstanceKlass(parser);
554 }
555
556 assert(ik == nullptr || CompressedKlassPointers::is_encodable(ik),
557 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
558
559 // Check for pending exception before adding to the loader data and incrementing
560 // class count. Can get OOM here.
561 if (HAS_PENDING_EXCEPTION) {
562 return nullptr;
563 }
564
565 return ik;
566 }
567
568 // copy method ordering from resource area to Metaspace
569 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
570 if (m != nullptr) {
571 // allocate a new array and copy contents (memcpy?)
572 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
573 for (int i = 0; i < m->length(); i++) {
574 _method_ordering->at_put(i, m->at(i));
575 }
576 } else {
577 _method_ordering = Universe::the_empty_int_array();
578 }
579 }
580
581 // create a new array of vtable_indices for default methods
582 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
583 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
584 assert(default_vtable_indices() == nullptr, "only create once");
585 set_default_vtable_indices(vtable_indices);
586 return vtable_indices;
587 }
588
589
590 InstanceKlass::InstanceKlass() {
591 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
592 }
593
594 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, markWord prototype_header, ReferenceType reference_type) :
595 Klass(kind, prototype_header),
596 _nest_members(nullptr),
597 _nest_host(nullptr),
598 _permitted_subclasses(nullptr),
599 _record_components(nullptr),
600 _static_field_size(parser.static_field_size()),
601 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
602 _itable_len(parser.itable_size()),
603 _nest_host_index(0),
604 _init_state(allocated),
605 _reference_type(reference_type),
606 _acmp_maps_offset(0),
607 _init_thread(nullptr),
608 _inline_layout_info_array(nullptr),
609 _loadable_descriptors(nullptr),
610 _acmp_maps_array(nullptr),
611 _adr_inline_klass_members(nullptr)
612 {
613 set_vtable_length(parser.vtable_size());
614 set_access_flags(parser.access_flags());
615 if (parser.is_hidden()) set_is_hidden();
616 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
617 false));
618 if (parser.has_inlined_fields()) {
619 set_has_inlined_fields();
620 }
621
622 assert(nullptr == _methods, "underlying memory not zeroed?");
623 assert(is_instance_klass(), "is layout incorrect?");
624 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
625 }
626
627 void InstanceKlass::set_is_cloneable() {
628 if (name() == vmSymbols::java_lang_invoke_MemberName()) {
629 assert(is_final(), "no subclasses allowed");
630 // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
631 } else if (reference_type() != REF_NONE) {
632 // Reference cloning should not be intrinsified and always happen in JVM_Clone.
633 } else {
634 set_is_cloneable_fast();
635 }
636 }
637
638 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
639 Array<Method*>* methods) {
640 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
641 !methods->in_aot_cache()) {
642 for (int i = 0; i < methods->length(); i++) {
643 Method* method = methods->at(i);
644 if (method == nullptr) continue; // maybe null if error processing
645 // Only want to delete methods that are not executing for RedefineClasses.
646 // The previous version will point to them so they're not totally dangling
647 assert (!method->on_stack(), "shouldn't be called with methods on stack");
648 MetadataFactory::free_metadata(loader_data, method);
649 }
650 MetadataFactory::free_array<Method*>(loader_data, methods);
651 }
652 }
653
654 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
655 const InstanceKlass* super_klass,
656 Array<InstanceKlass*>* local_interfaces,
657 Array<InstanceKlass*>* transitive_interfaces) {
658 // Only deallocate transitive interfaces if not empty, same as super class
659 // or same as local interfaces. See code in parseClassFile.
660 Array<InstanceKlass*>* ti = transitive_interfaces;
661 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
662 // check that the interfaces don't come from super class
663 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
664 super_klass->transitive_interfaces();
665 if (ti != sti && ti != nullptr && !ti->in_aot_cache()) {
666 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
667 }
668 }
669
670 // local interfaces can be empty
671 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
672 local_interfaces != nullptr && !local_interfaces->in_aot_cache()) {
673 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
674 }
675 }
676
677 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
678 Array<RecordComponent*>* record_components) {
679 if (record_components != nullptr && !record_components->in_aot_cache()) {
680 for (int i = 0; i < record_components->length(); i++) {
681 RecordComponent* record_component = record_components->at(i);
682 MetadataFactory::free_metadata(loader_data, record_component);
683 }
684 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
685 }
686 }
687
688 // This function deallocates the metadata and C heap pointers that the
689 // InstanceKlass points to.
690 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
691 // Orphan the mirror first, CMS thinks it's still live.
692 if (java_mirror() != nullptr) {
693 java_lang_Class::set_klass(java_mirror(), nullptr);
694 }
695
696 // Also remove mirror from handles
697 loader_data->remove_handle(_java_mirror);
698
699 // Need to take this class off the class loader data list.
700 loader_data->remove_class(this);
701
702 // The array_klass for this class is created later, after error handling.
703 // For class redefinition, we keep the original class so this scratch class
704 // doesn't have an array class. Either way, assert that there is nothing
705 // to deallocate.
706 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
707
708 // Release C heap allocated data that this points to, which includes
709 // reference counting symbol names.
710 // Can't release the constant pool or MethodData C heap data here because the constant
711 // pool can be deallocated separately from the InstanceKlass for default methods and
712 // redefine classes. MethodData can also be released separately.
713 release_C_heap_structures(/* release_sub_metadata */ false);
714
715 deallocate_methods(loader_data, methods());
716 set_methods(nullptr);
717
718 deallocate_record_components(loader_data, record_components());
719 set_record_components(nullptr);
720
721 if (method_ordering() != nullptr &&
722 method_ordering() != Universe::the_empty_int_array() &&
723 !method_ordering()->in_aot_cache()) {
724 MetadataFactory::free_array<int>(loader_data, method_ordering());
725 }
726 set_method_ordering(nullptr);
727
728 // default methods can be empty
729 if (default_methods() != nullptr &&
730 default_methods() != Universe::the_empty_method_array() &&
731 !default_methods()->in_aot_cache()) {
732 MetadataFactory::free_array<Method*>(loader_data, default_methods());
733 }
734 // Do NOT deallocate the default methods, they are owned by superinterfaces.
735 set_default_methods(nullptr);
736
737 // default methods vtable indices can be empty
738 if (default_vtable_indices() != nullptr &&
739 !default_vtable_indices()->in_aot_cache()) {
740 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
741 }
742 set_default_vtable_indices(nullptr);
743
744
745 // This array is in Klass, but remove it with the InstanceKlass since
746 // this place would be the only caller and it can share memory with transitive
747 // interfaces.
748 if (secondary_supers() != nullptr &&
749 secondary_supers() != Universe::the_empty_klass_array() &&
750 // see comments in compute_secondary_supers about the following cast
751 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
752 !secondary_supers()->in_aot_cache()) {
753 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
754 }
755 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
756
757 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
758 set_transitive_interfaces(nullptr);
759 set_local_interfaces(nullptr);
760
761 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->in_aot_cache()) {
762 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
763 }
764 set_fieldinfo_stream(nullptr);
765
766 if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->in_aot_cache()) {
767 MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
768 }
769 set_fieldinfo_search_table(nullptr);
770
771 if (fields_status() != nullptr && !fields_status()->in_aot_cache()) {
772 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
773 }
774 set_fields_status(nullptr);
775
776 if (inline_layout_info_array() != nullptr) {
777 MetadataFactory::free_array<InlineLayoutInfo>(loader_data, inline_layout_info_array());
778 }
779 set_inline_layout_info_array(nullptr);
780
781 // If a method from a redefined class is using this constant pool, don't
782 // delete it, yet. The new class's previous version will point to this.
783 if (constants() != nullptr) {
784 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
785 if (!constants()->in_aot_cache()) {
786 HeapShared::remove_scratch_resolved_references(constants());
787 MetadataFactory::free_metadata(loader_data, constants());
788 }
789 // Delete any cached resolution errors for the constant pool
790 SystemDictionary::delete_resolution_error(constants());
791
792 set_constants(nullptr);
793 }
794
795 if (inner_classes() != nullptr &&
796 inner_classes() != Universe::the_empty_short_array() &&
797 !inner_classes()->in_aot_cache()) {
798 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
799 }
800 set_inner_classes(nullptr);
801
802 if (nest_members() != nullptr &&
803 nest_members() != Universe::the_empty_short_array() &&
804 !nest_members()->in_aot_cache()) {
805 MetadataFactory::free_array<jushort>(loader_data, nest_members());
806 }
807 set_nest_members(nullptr);
808
809 if (permitted_subclasses() != nullptr &&
810 permitted_subclasses() != Universe::the_empty_short_array() &&
811 !permitted_subclasses()->in_aot_cache()) {
812 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
813 }
814 set_permitted_subclasses(nullptr);
815
816 if (loadable_descriptors() != nullptr &&
817 loadable_descriptors() != Universe::the_empty_short_array() &&
818 !loadable_descriptors()->in_aot_cache()) {
819 MetadataFactory::free_array<jushort>(loader_data, loadable_descriptors());
820 }
821 set_loadable_descriptors(nullptr);
822
823 if (acmp_maps_array() != nullptr) {
824 MetadataFactory::free_array<int>(loader_data, acmp_maps_array());
825 }
826 set_acmp_maps_array(nullptr);
827
828 // We should deallocate the Annotations instance if it's not in shared spaces.
829 if (annotations() != nullptr && !annotations()->in_aot_cache()) {
830 MetadataFactory::free_metadata(loader_data, annotations());
831 }
832 set_annotations(nullptr);
833
834 SystemDictionaryShared::handle_class_unloading(this);
835
836 #if INCLUDE_CDS_JAVA_HEAP
837 if (CDSConfig::is_dumping_heap()) {
838 HeapShared::remove_scratch_objects(this);
839 }
840 #endif
841 }
842
843 bool InstanceKlass::is_record() const {
844 return _record_components != nullptr &&
845 is_final() &&
846 super() == vmClasses::Record_klass();
847 }
848
849 bool InstanceKlass::is_sealed() const {
850 return _permitted_subclasses != nullptr &&
851 _permitted_subclasses != Universe::the_empty_short_array();
852 }
853
854 // JLS 8.9: An enum class is either implicitly final and derives
855 // from java.lang.Enum, or else is implicitly sealed to its
856 // anonymous subclasses. This query detects both kinds.
857 // It does not validate the finality or
858 // sealing conditions: it merely checks for a super of Enum.
859 // This is sufficient for recognizing well-formed enums.
860 bool InstanceKlass::is_enum_subclass() const {
861 InstanceKlass* s = super();
862 return (s == vmClasses::Enum_klass() ||
863 (s != nullptr && s->super() == vmClasses::Enum_klass()));
864 }
865
866 bool InstanceKlass::should_be_initialized() const {
867 return !is_initialized();
868 }
869
870 // Static size helper
871 int InstanceKlass::size(int vtable_length,
872 int itable_length,
873 int nonstatic_oop_map_size,
874 bool is_interface,
875 bool is_inline_type) {
876 return align_metadata_size(header_size() +
877 vtable_length +
878 itable_length +
879 nonstatic_oop_map_size +
880 (is_interface ? (int)sizeof(Klass*) / wordSize : 0) +
881 (is_inline_type ? (int)sizeof(InlineKlass::Members) / wordSize : 0));
882 }
883
884 int InstanceKlass::size() const {
885 return size(vtable_length(),
886 itable_length(),
887 nonstatic_oop_map_size(),
888 is_interface(),
889 is_inline_klass());
890 }
891
892 klassItable InstanceKlass::itable() const {
893 return klassItable(const_cast<InstanceKlass*>(this));
894 }
895
896 // JVMTI spec thinks there are signers and protection domain in the
897 // instanceKlass. These accessors pretend these fields are there.
898 // The hprof specification also thinks these fields are in InstanceKlass.
899 oop InstanceKlass::protection_domain() const {
900 // return the protection_domain from the mirror
901 return java_lang_Class::protection_domain(java_mirror());
902 }
903
904 objArrayOop InstanceKlass::signers() const {
905 // return the signers from the mirror
906 return java_lang_Class::signers(java_mirror());
907 }
908
909 oop InstanceKlass::init_lock() const {
910 // return the init lock from the mirror
911 oop lock = java_lang_Class::init_lock(java_mirror());
912 // Prevent reordering with any access of initialization state
913 OrderAccess::loadload();
914 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
915 "only fully initialized state can have a null lock");
916 return lock;
917 }
918
919 // Set the initialization lock to null so the object can be GC'ed. Any racing
920 // threads to get this lock will see a null lock and will not lock.
921 // That's okay because they all check for initialized state after getting
922 // the lock and return. For preempted vthreads we keep the oop protected
923 // in the ObjectMonitor (see ObjectMonitor::set_object_strong()).
924 void InstanceKlass::fence_and_clear_init_lock() {
925 // make sure previous stores are all done, notably the init_state.
926 OrderAccess::storestore();
927 java_lang_Class::clear_init_lock(java_mirror());
928 assert(!is_not_initialized(), "class must be initialized now");
929 }
930
931 class PreemptableInitCall {
932 JavaThread* _thread;
933 bool _previous;
934 DEBUG_ONLY(InstanceKlass* _previous_klass;)
935 public:
936 PreemptableInitCall(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
937 _previous = thread->at_preemptable_init();
938 _thread->set_at_preemptable_init(true);
939 DEBUG_ONLY(_previous_klass = _thread->preempt_init_klass();)
940 DEBUG_ONLY(_thread->set_preempt_init_klass(ik));
941 }
942 ~PreemptableInitCall() {
943 _thread->set_at_preemptable_init(_previous);
944 DEBUG_ONLY(_thread->set_preempt_init_klass(_previous_klass));
945 }
946 };
947
948 void InstanceKlass::initialize_preemptable(TRAPS) {
949 if (this->should_be_initialized()) {
950 PreemptableInitCall pic(THREAD, this);
951 initialize_impl(THREAD);
952 } else {
953 assert(is_initialized(), "sanity check");
954 }
955 }
956
957 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
958 // process. The step comments refers to the procedure described in that section.
959 // Note: implementation moved to static method to expose the this pointer.
960 void InstanceKlass::initialize(TRAPS) {
961 if (this->should_be_initialized()) {
962 initialize_impl(CHECK);
963 // Note: at this point the class may be initialized
964 // OR it may be in the state of being initialized
965 // in case of recursive initialization!
966 } else {
967 assert(is_initialized(), "sanity check");
968 }
969 }
970
971 #ifdef ASSERT
972 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
973 assert(has_aot_initialized_mirror(), "must be");
974
975 InstanceKlass* s = super();
976 if (s != nullptr) {
977 DEBUG_ONLY(ResourceMark rm);
978 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
979 s->external_name(), external_name());
980 s->assert_no_clinit_will_run_for_aot_initialized_class();
981 }
982
983 Array<InstanceKlass*>* interfaces = local_interfaces();
984 int len = interfaces->length();
985 for (int i = 0; i < len; i++) {
986 InstanceKlass* intf = interfaces->at(i);
987 if (!intf->is_initialized()) {
988 ResourceMark rm;
989 // Note: an interface needs to be marked as is_initialized() only if
990 // - it has a <clinit>
991 // - it has declared a default method.
992 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
993 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
994 intf->external_name(), external_name());
995 }
996 }
997 }
998 #endif
999
1000 #if INCLUDE_CDS
1001 // early_init -- we are moving this class into the fully_initialized state before the
1002 // JVM is able to execute any bytecodes. See AOTLinkedClassBulkLoader::is_initializing_classes_early().
1003 void InstanceKlass::initialize_with_aot_initialized_mirror(bool early_init, TRAPS) {
1004 assert(has_aot_initialized_mirror(), "must be");
1005 assert(CDSConfig::is_loading_heap(), "must be");
1006 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
1007 assert_no_clinit_will_run_for_aot_initialized_class();
1008
1009 if (is_initialized()) {
1010 return;
1011 }
1012
1013 if (log_is_enabled(Info, aot, init)) {
1014 ResourceMark rm;
1015 log_info(aot, init)("%s (aot-inited%s)", external_name(), early_init ? ", early" : "");
1016 }
1017
1018 if (is_runtime_setup_required()) {
1019 assert(!early_init, "must not call");
1020 // Need to take the slow path, which will call the runtimeSetup() function instead
1021 // of <clinit>
1022 initialize(CHECK);
1023 return;
1024 }
1025
1026 LogTarget(Info, class, init) lt;
1027 if (lt.is_enabled()) {
1028 ResourceMark rm(THREAD);
1029 LogStream ls(lt);
1030 ls.print("%d Initializing ", call_class_initializer_counter++);
1031 name()->print_value_on(&ls);
1032 ls.print_cr("(aot-inited) (" PTR_FORMAT ") by thread \"%s\"",
1033 p2i(this), THREAD->name());
1034 }
1035
1036 if (early_init) {
1037 precond(AOTLinkedClassBulkLoader::is_initializing_classes_early());
1038 precond(is_linked());
1039 precond(init_thread() == nullptr);
1040 set_init_state(fully_initialized);
1041 fence_and_clear_init_lock();
1042 return;
1043 }
1044
1045 link_class(CHECK);
1046
1047 #ifdef ASSERT
1048 {
1049 Handle h_init_lock(THREAD, init_lock());
1050 ObjectLocker ol(h_init_lock, THREAD);
1051 assert(!is_initialized(), "sanity");
1052 assert(!is_being_initialized(), "sanity");
1053 assert(!is_in_error_state(), "sanity");
1054 }
1055 #endif
1056
1057 set_init_thread(THREAD);
1058 set_initialization_state_and_notify(fully_initialized, CHECK);
1059 }
1060 #endif
1061
1062 bool InstanceKlass::verify_code(TRAPS) {
1063 // 1) Verify the bytecodes
1064 return Verifier::verify(this, should_verify_class(), THREAD);
1065 }
1066
1067 static void load_classes_from_loadable_descriptors_attribute(InstanceKlass *ik, TRAPS) {
1068 if (ik->loadable_descriptors() != Universe::the_empty_short_array() && PreloadClasses) {
1069 ResourceMark rm(THREAD);
1070 HandleMark hm(THREAD);
1071 for (int i = 0; i < ik->loadable_descriptors()->length(); i++) {
1072 Symbol* sig = ik->constants()->symbol_at(ik->loadable_descriptors()->at(i));
1073 if (!Signature::has_envelope(sig)) continue;
1074 TempNewSymbol class_name = Signature::strip_envelope(sig);
1075 if (class_name == ik->name()) continue;
1076 log_info(class, preload)("Preloading of class %s during linking of class %s "
1077 "because of the class is listed in the LoadableDescriptors attribute",
1078 sig->as_C_string(), ik->name()->as_C_string());
1079 oop loader = ik->class_loader();
1080 Klass* klass = SystemDictionary::resolve_or_null(class_name,
1081 Handle(THREAD, loader), THREAD);
1082 if (HAS_PENDING_EXCEPTION) {
1083 CLEAR_PENDING_EXCEPTION;
1084 }
1085 if (klass != nullptr) {
1086 log_info(class, preload)("Preloading of class %s during linking of class %s "
1087 "(cause: LoadableDescriptors attribute) succeeded",
1088 class_name->as_C_string(), ik->name()->as_C_string());
1089 if (!klass->is_inline_klass()) {
1090 // Non value classes are allowed by the current spec, but it could be an indication
1091 // of an issue so let's log a warning
1092 log_info(class, preload)("Preloading of class %s during linking of class %s "
1093 "(cause: LoadableDescriptors attribute) but loaded class is not a value class",
1094 class_name->as_C_string(), ik->name()->as_C_string());
1095 }
1096 } else {
1097 log_info(class, preload)("Preloading of class %s during linking of class %s "
1098 "(cause: LoadableDescriptors attribute) failed",
1099 class_name->as_C_string(), ik->name()->as_C_string());
1100 }
1101 }
1102 }
1103 }
1104
1105 void InstanceKlass::link_class(TRAPS) {
1106 assert(is_loaded(), "must be loaded");
1107 if (!is_linked()) {
1108 link_class_impl(CHECK);
1109 }
1110 }
1111
1112 // Called to verify that a class can link during initialization, without
1113 // throwing a VerifyError.
1114 bool InstanceKlass::link_class_or_fail(TRAPS) {
1115 assert(is_loaded(), "must be loaded");
1116 if (!is_linked()) {
1117 link_class_impl(CHECK_false);
1118 }
1119 return is_linked();
1120 }
1121
1122 bool InstanceKlass::link_class_impl(TRAPS) {
1123 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
1124 // This is for CDS static dump only -- we use the in_error_state to indicate that
1125 // the class has failed verification. Throwing the NoClassDefFoundError here is just
1126 // a convenient way to stop repeat attempts to verify the same (bad) class.
1127 //
1128 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
1129 // if we are executing Java code. This is not a problem for CDS dumping phase since
1130 // it doesn't execute any Java code.
1131 ResourceMark rm(THREAD);
1132 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1133 Exceptions::fthrow(THREAD_AND_LOCATION,
1134 vmSymbols::java_lang_NoClassDefFoundError(),
1135 "Class %s, or one of its supertypes, failed class initialization",
1136 external_name());
1137 return false;
1138 }
1139 // return if already verified
1140 if (is_linked()) {
1141 return true;
1142 }
1143
1144 // Timing
1145 // timer handles recursion
1146 JavaThread* jt = THREAD;
1147
1148 // link super class before linking this class
1149 InstanceKlass* super_klass = super();
1150 if (super_klass != nullptr) {
1151 if (super_klass->is_interface()) { // check if super class is an interface
1152 ResourceMark rm(THREAD);
1153 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1154 Exceptions::fthrow(
1155 THREAD_AND_LOCATION,
1156 vmSymbols::java_lang_IncompatibleClassChangeError(),
1157 "class %s has interface %s as super class",
1158 external_name(),
1159 super_klass->external_name()
1160 );
1161 return false;
1162 }
1163
1164 super_klass->link_class_impl(CHECK_false);
1165 }
1166
1167 // link all interfaces implemented by this class before linking this class
1168 Array<InstanceKlass*>* interfaces = local_interfaces();
1169 int num_interfaces = interfaces->length();
1170 for (int index = 0; index < num_interfaces; index++) {
1171 InstanceKlass* interk = interfaces->at(index);
1172 interk->link_class_impl(CHECK_false);
1173 }
1174
1175 if (Arguments::is_valhalla_enabled()) {
1176 // Aggressively preloading all classes from the LoadableDescriptors attribute
1177 // so inline classes can be scalarized in the calling conventions computed below
1178 load_classes_from_loadable_descriptors_attribute(this, THREAD);
1179 assert(!HAS_PENDING_EXCEPTION, "Shouldn't have pending exceptions from call above");
1180 }
1181
1182 // in case the class is linked in the process of linking its superclasses
1183 if (is_linked()) {
1184 return true;
1185 }
1186
1187 // trace only the link time for this klass that includes
1188 // the verification time
1189 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
1190 ClassLoader::perf_class_link_selftime(),
1191 ClassLoader::perf_classes_linked(),
1192 jt->get_thread_stat()->perf_recursion_counts_addr(),
1193 jt->get_thread_stat()->perf_timers_addr(),
1194 PerfClassTraceTime::CLASS_LINK);
1195
1196 // verification & rewriting
1197 {
1198 HandleMark hm(THREAD);
1199 Handle h_init_lock(THREAD, init_lock());
1200 ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE_false);
1201 // Don't allow preemption if we link/initialize classes below,
1202 // since that would release this monitor while we are in the
1203 // middle of linking this class.
1204 NoPreemptMark npm(THREAD);
1205
1206 // rewritten will have been set if loader constraint error found
1207 // on an earlier link attempt
1208 // don't verify or rewrite if already rewritten
1209 //
1210
1211 if (!is_linked()) {
1212 if (!is_rewritten()) {
1213 if (in_aot_cache()) {
1214 assert(!verified_at_dump_time(), "must be");
1215 }
1216 {
1217 bool verify_ok = verify_code(THREAD);
1218 if (!verify_ok) {
1219 return false;
1220 }
1221 }
1222
1223 // Just in case a side-effect of verify linked this class already
1224 // (which can sometimes happen since the verifier loads classes
1225 // using custom class loaders, which are free to initialize things)
1226 if (is_linked()) {
1227 return true;
1228 }
1229
1230 // also sets rewritten
1231 rewrite_class(CHECK_false);
1232 } else if (in_aot_cache()) {
1233 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1234 }
1235
1236 // relocate jsrs and link methods after they are all rewritten
1237 link_methods(CHECK_false);
1238
1239 // Initialize the vtable and interface table after
1240 // methods have been rewritten since rewrite may
1241 // fabricate new Method*s.
1242 // also does loader constraint checking
1243 //
1244 // initialize_vtable and initialize_itable need to be rerun
1245 // for a shared class if
1246 // 1) the class is loaded by custom class loader or
1247 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1248 // 3) the class was not verified during dump time
1249 bool need_init_table = true;
1250 if (in_aot_cache() && verified_at_dump_time() &&
1251 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1252 need_init_table = false;
1253 }
1254 if (need_init_table) {
1255 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1256 itable().initialize_itable_and_check_constraints(CHECK_false);
1257 }
1258 #ifdef ASSERT
1259 vtable().verify(tty, true);
1260 // In case itable verification is ever added.
1261 // itable().verify(tty, true);
1262 #endif
1263 if (Universe::is_fully_initialized()) {
1264 DeoptimizationScope deopt_scope;
1265 {
1266 // Now mark all code that assumes the class is not linked.
1267 // Set state under the Compile_lock also.
1268 MutexLocker ml(THREAD, Compile_lock);
1269
1270 set_init_state(linked);
1271 CodeCache::mark_dependents_on(&deopt_scope, this);
1272 }
1273 // Perform the deopt handshake outside Compile_lock.
1274 deopt_scope.deoptimize_marked();
1275 } else {
1276 set_init_state(linked);
1277 }
1278 if (JvmtiExport::should_post_class_prepare()) {
1279 JvmtiExport::post_class_prepare(THREAD, this);
1280 }
1281 }
1282 }
1283
1284 if (log_is_enabled(Info, class, link)) {
1285 ResourceMark rm(THREAD);
1286 log_info(class, link)("Linked class %s", external_name());
1287 }
1288
1289 return true;
1290 }
1291
1292 // Rewrite the byte codes of all of the methods of a class.
1293 // The rewriter must be called exactly once. Rewriting must happen after
1294 // verification but before the first method of the class is executed.
1295 void InstanceKlass::rewrite_class(TRAPS) {
1296 assert(is_loaded(), "must be loaded");
1297 if (is_rewritten()) {
1298 assert(in_aot_cache(), "rewriting an unshared class?");
1299 return;
1300 }
1301 Rewriter::rewrite(this, CHECK);
1302 set_rewritten();
1303 }
1304
1305 // Now relocate and link method entry points after class is rewritten.
1306 // This is outside is_rewritten flag. In case of an exception, it can be
1307 // executed more than once.
1308 void InstanceKlass::link_methods(TRAPS) {
1309 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1310
1311 int len = methods()->length();
1312 for (int i = len-1; i >= 0; i--) {
1313 methodHandle m(THREAD, methods()->at(i));
1314
1315 // Set up method entry points for compiler and interpreter .
1316 m->link_method(m, CHECK);
1317 }
1318 }
1319
1320 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1321 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1322 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1323 for (int i = 0; i < local_interfaces()->length(); ++i) {
1324 InstanceKlass* ik = local_interfaces()->at(i);
1325
1326 // Initialization is depth first search ie. we start with top of the inheritance tree
1327 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1328 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1329 if (ik->has_nonstatic_concrete_methods()) {
1330 ik->initialize_super_interfaces(CHECK);
1331 }
1332
1333 // Only initialize() interfaces that "declare" concrete methods.
1334 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1335 ik->initialize(CHECK);
1336 }
1337 }
1338 }
1339
1340 using InitializationErrorTable = HashTable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1341 static InitializationErrorTable* _initialization_error_table;
1342
1343 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1344 // Create the same exception with a message indicating the thread name,
1345 // and the StackTraceElements.
1346 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1347 ResourceMark rm(current);
1348 if (init_error.is_null()) {
1349 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1350
1351 // We failed to create the new exception, most likely due to either out-of-memory or
1352 // a stackoverflow error. If the original exception was either of those then we save
1353 // the shared, pre-allocated, stackless, instance of that exception.
1354 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1355 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1356 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1357 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1358 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1359 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1360 } else {
1361 return;
1362 }
1363 }
1364
1365 MutexLocker ml(current, ClassInitError_lock);
1366 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1367 bool created;
1368 if (_initialization_error_table == nullptr) {
1369 _initialization_error_table = new (mtClass) InitializationErrorTable();
1370 }
1371 _initialization_error_table->put_if_absent(this, elem, &created);
1372 assert(created, "Initialization is single threaded");
1373 log_trace(class, init)("Initialization error added for class %s", external_name());
1374 }
1375
1376 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1377 MutexLocker ml(current, ClassInitError_lock);
1378 if (_initialization_error_table == nullptr) {
1379 return nullptr;
1380 }
1381 OopHandle* h = _initialization_error_table->get(this);
1382 return (h != nullptr) ? h->resolve() : nullptr;
1383 }
1384
1385 // Need to remove entries for unloaded classes.
1386 void InstanceKlass::clean_initialization_error_table() {
1387 struct InitErrorTableCleaner {
1388 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1389 if (!ik->is_loader_alive()) {
1390 h.release(Universe::vm_global());
1391 return true;
1392 } else {
1393 return false;
1394 }
1395 }
1396 };
1397
1398 assert_locked_or_safepoint(ClassInitError_lock);
1399 InitErrorTableCleaner cleaner;
1400 if (_initialization_error_table != nullptr) {
1401 _initialization_error_table->unlink(&cleaner);
1402 }
1403 }
1404
1405 class ThreadWaitingForClassInit : public StackObj {
1406 JavaThread* _thread;
1407 public:
1408 ThreadWaitingForClassInit(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1409 _thread->set_class_to_be_initialized(ik);
1410 }
1411 ~ThreadWaitingForClassInit() {
1412 _thread->set_class_to_be_initialized(nullptr);
1413 }
1414 };
1415
1416 void InstanceKlass::initialize_impl(TRAPS) {
1417 HandleMark hm(THREAD);
1418
1419 // Make sure klass is linked (verified) before initialization
1420 // A class could already be verified, since it has been reflected upon.
1421 link_class(CHECK);
1422
1423 DTRACE_CLASSINIT_PROBE(required, -1);
1424
1425 bool wait = false;
1426
1427 JavaThread* jt = THREAD;
1428
1429 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1430
1431 // refer to the JVM book page 47 for description of steps
1432 // Step 1
1433 {
1434 Handle h_init_lock(THREAD, init_lock());
1435 ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE);
1436
1437 // Step 2
1438 // If we were to use wait() instead of waitInterruptibly() then
1439 // we might end up throwing IE from link/symbol resolution sites
1440 // that aren't expected to throw. This would wreak havoc. See 6320309.
1441 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1442 if (debug_logging_enabled) {
1443 ResourceMark rm(jt);
1444 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1445 jt->name(), external_name(), init_thread_name());
1446 }
1447 wait = true;
1448 ThreadWaitingForClassInit twcl(THREAD, this);
1449 ol.wait_uninterruptibly(CHECK_PREEMPTABLE);
1450 }
1451
1452 // Step 3
1453 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1454 if (debug_logging_enabled) {
1455 ResourceMark rm(jt);
1456 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1457 jt->name(), external_name());
1458 }
1459 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1460 return;
1461 }
1462
1463 // Step 4
1464 if (is_initialized()) {
1465 if (debug_logging_enabled) {
1466 ResourceMark rm(jt);
1467 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1468 jt->name(), external_name());
1469 }
1470 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1471 return;
1472 }
1473
1474 // Step 5
1475 if (is_in_error_state()) {
1476 if (debug_logging_enabled) {
1477 ResourceMark rm(jt);
1478 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1479 jt->name(), external_name());
1480 }
1481
1482 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1483 ResourceMark rm(THREAD);
1484 Handle cause(THREAD, get_initialization_error(THREAD));
1485
1486 stringStream ss;
1487 ss.print("Could not initialize class %s", external_name());
1488 if (cause.is_null()) {
1489 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1490 } else {
1491 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1492 ss.as_string(), cause);
1493 }
1494 } else {
1495
1496 // Step 6
1497 set_init_state(being_initialized);
1498 set_init_thread(jt);
1499 if (debug_logging_enabled) {
1500 ResourceMark rm(jt);
1501 log_debug(class, init)("Thread \"%s\" is initializing %s",
1502 jt->name(), external_name());
1503 }
1504 }
1505 }
1506
1507 // Block preemption once we are the initializer thread. Unmounting now
1508 // would complicate the reentrant case (identity is platform thread).
1509 NoPreemptMark npm(THREAD);
1510
1511 // Pre-allocating an all-zero value to be used to reset nullable flat storages
1512 if (is_inline_klass()) {
1513 InlineKlass* vk = InlineKlass::cast(this);
1514 if (vk->supports_nullable_layouts()) {
1515 oop val = vk->allocate_instance(THREAD);
1516 if (HAS_PENDING_EXCEPTION) {
1517 Handle e(THREAD, PENDING_EXCEPTION);
1518 CLEAR_PENDING_EXCEPTION;
1519 {
1520 EXCEPTION_MARK;
1521 add_initialization_error(THREAD, e);
1522 // Locks object, set state, and notify all waiting threads
1523 set_initialization_state_and_notify(initialization_error, THREAD);
1524 CLEAR_PENDING_EXCEPTION;
1525 }
1526 THROW_OOP(e());
1527 }
1528 vk->set_null_reset_value(val);
1529 }
1530 }
1531
1532 // Step 7
1533 // Next, if C is a class rather than an interface, initialize it's super class and super
1534 // interfaces.
1535 if (!is_interface()) {
1536 Klass* super_klass = super();
1537 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1538 super_klass->initialize(THREAD);
1539 }
1540 // If C implements any interface that declares a non-static, concrete method,
1541 // the initialization of C triggers initialization of its super interfaces.
1542 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1543 // having a superinterface that declares, non-static, concrete methods
1544 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1545 initialize_super_interfaces(THREAD);
1546 }
1547
1548 // If any exceptions, complete abruptly, throwing the same exception as above.
1549 if (HAS_PENDING_EXCEPTION) {
1550 Handle e(THREAD, PENDING_EXCEPTION);
1551 CLEAR_PENDING_EXCEPTION;
1552 {
1553 EXCEPTION_MARK;
1554 add_initialization_error(THREAD, e);
1555 // Locks object, set state, and notify all waiting threads
1556 set_initialization_state_and_notify(initialization_error, THREAD);
1557 CLEAR_PENDING_EXCEPTION;
1558 }
1559 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1560 THROW_OOP(e());
1561 }
1562 }
1563
1564
1565 // Step 8
1566 {
1567 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1568 if (class_initializer() != nullptr) {
1569 // Timer includes any side effects of class initialization (resolution,
1570 // etc), but not recursive entry into call_class_initializer().
1571 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1572 ClassLoader::perf_class_init_selftime(),
1573 ClassLoader::perf_classes_inited(),
1574 jt->get_thread_stat()->perf_recursion_counts_addr(),
1575 jt->get_thread_stat()->perf_timers_addr(),
1576 PerfClassTraceTime::CLASS_CLINIT);
1577 call_class_initializer(THREAD);
1578 } else {
1579 // The elapsed time is so small it's not worth counting.
1580 if (UsePerfData) {
1581 ClassLoader::perf_classes_inited()->inc();
1582 }
1583 call_class_initializer(THREAD);
1584 }
1585
1586 if (has_strict_static_fields() && !HAS_PENDING_EXCEPTION) {
1587 // Step 9 also verifies that strict static fields have been initialized.
1588 // Status bits were set in ClassFileParser::post_process_parsed_stream.
1589 // After <clinit>, bits must all be clear, or else we must throw an error.
1590 // This is an extremely fast check, so we won't bother with a timer.
1591 assert(fields_status() != nullptr, "");
1592 Symbol* bad_strict_static = nullptr;
1593 for (int index = 0; index < fields_status()->length(); index++) {
1594 // Very fast loop over single byte array looking for a set bit.
1595 if (fields_status()->adr_at(index)->is_strict_static_unset()) {
1596 // This strict static field has not been set by the class initializer.
1597 // Note that in the common no-error case, we read no field metadata.
1598 // We only unpack it when we need to report an error.
1599 FieldInfo fi = field(index);
1600 bad_strict_static = fi.name(constants());
1601 if (debug_logging_enabled) {
1602 ResourceMark rm(jt);
1603 const char* msg = format_strict_static_message(bad_strict_static);
1604 log_debug(class, init)("%s", msg);
1605 } else {
1606 // If we are not logging, do not bother to look for a second offense.
1607 break;
1608 }
1609 }
1610 }
1611 if (bad_strict_static != nullptr) {
1612 throw_strict_static_exception(bad_strict_static, "is unset after initialization of", THREAD);
1613 }
1614 }
1615 }
1616
1617 // Step 9
1618 if (!HAS_PENDING_EXCEPTION) {
1619 set_initialization_state_and_notify(fully_initialized, CHECK);
1620 DEBUG_ONLY(vtable().verify(tty, true);)
1621 CompilationPolicy::replay_training_at_init(this, THREAD);
1622 }
1623 else {
1624 // Step 10 and 11
1625 Handle e(THREAD, PENDING_EXCEPTION);
1626 CLEAR_PENDING_EXCEPTION;
1627 // JVMTI has already reported the pending exception
1628 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1629 JvmtiExport::clear_detected_exception(jt);
1630 {
1631 EXCEPTION_MARK;
1632 add_initialization_error(THREAD, e);
1633 set_initialization_state_and_notify(initialization_error, THREAD);
1634 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1635 // JVMTI has already reported the pending exception
1636 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1637 JvmtiExport::clear_detected_exception(jt);
1638 }
1639 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1640 if (e->is_a(vmClasses::Error_klass())) {
1641 THROW_OOP(e());
1642 } else {
1643 JavaCallArguments args(e);
1644 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1645 vmSymbols::throwable_void_signature(),
1646 &args);
1647 }
1648 }
1649 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1650 }
1651
1652
1653 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1654 Handle h_init_lock(THREAD, init_lock());
1655 if (h_init_lock() != nullptr) {
1656 ObjectLocker ol(h_init_lock, THREAD);
1657 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1658 set_init_state(state);
1659 fence_and_clear_init_lock();
1660 ol.notify_all(CHECK);
1661 } else {
1662 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1663 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1664 set_init_state(state);
1665 }
1666 }
1667
1668 void InstanceKlass::notify_strict_static_access(int field_index, bool is_writing, TRAPS) {
1669 guarantee(field_index >= 0 && field_index < fields_status()->length(), "valid field index");
1670 DEBUG_ONLY(FieldInfo debugfi = field(field_index));
1671 assert(debugfi.access_flags().is_strict(), "");
1672 assert(debugfi.access_flags().is_static(), "");
1673 FieldStatus& fs = *fields_status()->adr_at(field_index);
1674 LogTarget(Trace, class, init) lt;
1675 if (lt.is_enabled()) {
1676 ResourceMark rm(THREAD);
1677 LogStream ls(lt);
1678 FieldInfo fi = field(field_index);
1679 ls.print("notify %s %s %s%s ",
1680 external_name(), is_writing? "Write" : "Read",
1681 fs.is_strict_static_unset() ? "Unset" : "(set)",
1682 fs.is_strict_static_unread() ? "+Unread" : "");
1683 fi.print(&ls, constants());
1684 }
1685 if (fs.is_strict_static_unset()) {
1686 assert(fs.is_strict_static_unread(), "ClassFileParser resp.");
1687 // If it is not set, there are only two reasonable things we can do here:
1688 // - mark it set if this is putstatic
1689 // - throw an error (Read-Before-Write) if this is getstatic
1690
1691 // The unset state is (or should be) transient, and observable only in one
1692 // thread during the execution of <clinit>. Something is wrong here as this
1693 // should not be possible
1694 guarantee(is_reentrant_initialization(THREAD), "unscoped access to strict static");
1695 if (is_writing) {
1696 // clear the "unset" bit, since the field is actually going to be written
1697 fs.update_strict_static_unset(false);
1698 } else {
1699 // throw an IllegalStateException, since we are reading before writing
1700 // see also InstanceKlass::initialize_impl, Step 8 (at end)
1701 Symbol* bad_strict_static = field(field_index).name(constants());
1702 throw_strict_static_exception(bad_strict_static, "is unset before first read in", CHECK);
1703 }
1704 } else {
1705 // Ensure no write after read for final strict statics
1706 FieldInfo fi = field(field_index);
1707 bool is_final = fi.access_flags().is_final();
1708 if (is_final) {
1709 // no final write after read, so observing a constant freezes it, as if <clinit> ended early
1710 // (maybe we could trust the constant a little earlier, before <clinit> ends)
1711 if (is_writing && !fs.is_strict_static_unread()) {
1712 Symbol* bad_strict_static = fi.name(constants());
1713 throw_strict_static_exception(bad_strict_static, "is set after read (as final) in", CHECK);
1714 } else if (!is_writing && fs.is_strict_static_unread()) {
1715 fs.update_strict_static_unread(false);
1716 }
1717 }
1718 }
1719 }
1720
1721 void InstanceKlass::throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS) {
1722 ResourceMark rm(THREAD);
1723 const char* msg = format_strict_static_message(field_name, when);
1724 THROW_MSG(vmSymbols::java_lang_IllegalStateException(), msg);
1725 }
1726
1727 const char* InstanceKlass::format_strict_static_message(Symbol* field_name, const char* when) {
1728 stringStream ss;
1729 ss.print("Strict static \"%s\" %s %s",
1730 field_name->as_C_string(),
1731 when == nullptr ? "is unset in" : when,
1732 external_name());
1733 return ss.as_string();
1734 }
1735
1736 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1737 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1738 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1739 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1740
1741 DeoptimizationScope deopt_scope;
1742 {
1743 MutexLocker ml(current, Compile_lock);
1744
1745 set_init_state(InstanceKlass::loaded);
1746 // make sure init_state store is already done.
1747 // The compiler reads the hierarchy outside of the Compile_lock.
1748 // Access ordering is used to add to hierarchy.
1749
1750 // Link into hierarchy.
1751 append_to_sibling_list(); // add to superklass/sibling list
1752 process_interfaces(); // handle all "implements" declarations
1753
1754 // Now mark all code that depended on old class hierarchy.
1755 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1756 if (Universe::is_fully_initialized()) {
1757 CodeCache::mark_dependents_on(&deopt_scope, this);
1758 }
1759 }
1760 // Perform the deopt handshake outside Compile_lock.
1761 deopt_scope.deoptimize_marked();
1762 }
1763
1764
1765 InstanceKlass* InstanceKlass::implementor() const {
1766 InstanceKlass* volatile* ik = adr_implementor();
1767 if (ik == nullptr) {
1768 return nullptr;
1769 } else {
1770 // This load races with inserts, and therefore needs acquire.
1771 InstanceKlass* ikls = AtomicAccess::load_acquire(ik);
1772 if (ikls != nullptr && !ikls->is_loader_alive()) {
1773 return nullptr; // don't return unloaded class
1774 } else {
1775 return ikls;
1776 }
1777 }
1778 }
1779
1780
1781 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1782 assert_locked_or_safepoint(Compile_lock);
1783 assert(is_interface(), "not interface");
1784 InstanceKlass* volatile* addr = adr_implementor();
1785 assert(addr != nullptr, "null addr");
1786 if (addr != nullptr) {
1787 AtomicAccess::release_store(addr, ik);
1788 }
1789 }
1790
1791 int InstanceKlass::nof_implementors() const {
1792 InstanceKlass* ik = implementor();
1793 if (ik == nullptr) {
1794 return 0;
1795 } else if (ik != this) {
1796 return 1;
1797 } else {
1798 return 2;
1799 }
1800 }
1801
1802 // The embedded _implementor field can only record one implementor.
1803 // When there are more than one implementors, the _implementor field
1804 // is set to the interface Klass* itself. Following are the possible
1805 // values for the _implementor field:
1806 // null - no implementor
1807 // implementor Klass* - one implementor
1808 // self - more than one implementor
1809 //
1810 // The _implementor field only exists for interfaces.
1811 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1812 if (Universe::is_fully_initialized()) {
1813 assert_lock_strong(Compile_lock);
1814 }
1815 assert(is_interface(), "not interface");
1816 // Filter out my subinterfaces.
1817 // (Note: Interfaces are never on the subklass list.)
1818 if (ik->is_interface()) return;
1819
1820 // Filter out subclasses whose supers already implement me.
1821 // (Note: CHA must walk subclasses of direct implementors
1822 // in order to locate indirect implementors.)
1823 InstanceKlass* super_ik = ik->super();
1824 if (super_ik != nullptr && super_ik->implements_interface(this))
1825 // We only need to check one immediate superclass, since the
1826 // implements_interface query looks at transitive_interfaces.
1827 // Any supers of the super have the same (or fewer) transitive_interfaces.
1828 return;
1829
1830 InstanceKlass* iklass = implementor();
1831 if (iklass == nullptr) {
1832 set_implementor(ik);
1833 } else if (iklass != this && iklass != ik) {
1834 // There is already an implementor. Use itself as an indicator of
1835 // more than one implementors.
1836 set_implementor(this);
1837 }
1838
1839 // The implementor also implements the transitive_interfaces
1840 for (int index = 0; index < local_interfaces()->length(); index++) {
1841 local_interfaces()->at(index)->add_implementor(ik);
1842 }
1843 }
1844
1845 void InstanceKlass::init_implementor() {
1846 if (is_interface()) {
1847 set_implementor(nullptr);
1848 }
1849 }
1850
1851
1852 void InstanceKlass::process_interfaces() {
1853 // link this class into the implementors list of every interface it implements
1854 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1855 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1856 InstanceKlass* interf = local_interfaces()->at(i);
1857 assert(interf->is_interface(), "expected interface");
1858 interf->add_implementor(this);
1859 }
1860 }
1861
1862 bool InstanceKlass::can_be_primary_super_slow() const {
1863 if (is_interface())
1864 return false;
1865 else
1866 return Klass::can_be_primary_super_slow();
1867 }
1868
1869 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1870 Array<InstanceKlass*>* transitive_interfaces) {
1871 // The secondaries are the implemented interfaces.
1872 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1873 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1874 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1875 int num_secondaries = num_extra_slots + interfaces->length();
1876 if (num_secondaries == 0) {
1877 // Must share this for correct bootstrapping!
1878 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1879 return nullptr;
1880 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1881 // We will reuse the transitive interfaces list if we're certain
1882 // it's in hash order.
1883 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1884 set_secondary_supers(interfaces, bitmap);
1885 return nullptr;
1886 }
1887 // Copy transitive interfaces to a temporary growable array to be constructed
1888 // into the secondary super list with extra slots.
1889 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1890 for (int i = 0; i < interfaces->length(); i++) {
1891 secondaries->push(interfaces->at(i));
1892 }
1893 return secondaries;
1894 }
1895
1896 bool InstanceKlass::implements_interface(Klass* k) const {
1897 if (this == k) return true;
1898 assert(k->is_interface(), "should be an interface class");
1899 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1900 if (transitive_interfaces()->at(i) == k) {
1901 return true;
1902 }
1903 }
1904 return false;
1905 }
1906
1907 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1908 // Verify direct super interface
1909 if (this == k) return true;
1910 assert(k->is_interface(), "should be an interface class");
1911 for (int i = 0; i < local_interfaces()->length(); i++) {
1912 if (local_interfaces()->at(i) == k) {
1913 return true;
1914 }
1915 }
1916 return false;
1917 }
1918
1919 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1920 if (TraceFinalizerRegistration) {
1921 tty->print("Registered ");
1922 i->print_value_on(tty);
1923 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1924 }
1925 instanceHandle h_i(THREAD, i);
1926 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1927 JavaValue result(T_VOID);
1928 JavaCallArguments args(h_i);
1929 methodHandle mh(THREAD, Universe::finalizer_register_method());
1930 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1931 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1932 return h_i();
1933 }
1934
1935 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1936 assert(!is_abstract() && !is_interface(), "Should not create this object");
1937 size_t size = size_helper(); // Query before forming handle.
1938 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1939 }
1940
1941 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1942 Klass* k = java_lang_Class::as_Klass(java_class);
1943 if (k == nullptr) {
1944 ResourceMark rm(THREAD);
1945 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1946 }
1947 InstanceKlass* ik = cast(k);
1948 ik->check_valid_for_instantiation(false, CHECK_NULL);
1949 ik->initialize(CHECK_NULL);
1950 return ik->allocate_instance(THREAD);
1951 }
1952
1953 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1954 return instanceHandle(THREAD, allocate_instance(THREAD));
1955 }
1956
1957 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1958 if (is_interface() || is_abstract()) {
1959 ResourceMark rm(THREAD);
1960 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1961 : vmSymbols::java_lang_InstantiationException(), external_name());
1962 }
1963 if (this == vmClasses::Class_klass()) {
1964 ResourceMark rm(THREAD);
1965 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1966 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1967 }
1968 }
1969
1970 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1971 // Need load-acquire for lock-free read
1972 if (array_klasses_acquire() == nullptr) {
1973
1974 // Recursively lock array allocation
1975 RecursiveLocker rl(MultiArray_lock, THREAD);
1976
1977 // Check if another thread created the array klass while we were waiting for the lock.
1978 if (array_klasses() == nullptr) {
1979 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1980 // use 'release' to pair with lock-free load
1981 release_set_array_klasses(k);
1982 }
1983 }
1984
1985 // array_klasses() will always be set at this point
1986 ObjArrayKlass* ak = array_klasses();
1987 assert(ak != nullptr, "should be set");
1988 return ak->array_klass(n, THREAD);
1989 }
1990
1991 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1992 // Need load-acquire for lock-free read
1993 ObjArrayKlass* oak = array_klasses_acquire();
1994 if (oak == nullptr) {
1995 return nullptr;
1996 } else {
1997 return oak->array_klass_or_null(n);
1998 }
1999 }
2000
2001 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
2002 return array_klass(1, THREAD);
2003 }
2004
2005 ArrayKlass* InstanceKlass::array_klass_or_null() {
2006 return array_klass_or_null(1);
2007 }
2008
2009 Method* InstanceKlass::class_initializer() const {
2010 Method* clinit = find_method(
2011 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
2012 if (clinit != nullptr && clinit->is_class_initializer()) {
2013 return clinit;
2014 }
2015 return nullptr;
2016 }
2017
2018 void InstanceKlass::call_class_initializer(TRAPS) {
2019 if (ReplayCompiles &&
2020 (ReplaySuppressInitializers == 1 ||
2021 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
2022 // Hide the existence of the initializer for the purpose of replaying the compile
2023 return;
2024 }
2025
2026 #if INCLUDE_CDS
2027 // This is needed to ensure the consistency of the archived heap objects.
2028 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
2029 AOTClassInitializer::call_runtime_setup(THREAD, this);
2030 return;
2031 } else if (has_archived_enum_objs()) {
2032 assert(in_aot_cache(), "must be");
2033 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
2034 if (initialized) {
2035 return;
2036 }
2037 }
2038 #endif
2039
2040 methodHandle h_method(THREAD, class_initializer());
2041 assert(!is_initialized(), "we cannot initialize twice");
2042 LogTarget(Info, class, init) lt;
2043 if (lt.is_enabled()) {
2044 ResourceMark rm(THREAD);
2045 LogStream ls(lt);
2046 ls.print("%d Initializing ", call_class_initializer_counter++);
2047 name()->print_value_on(&ls);
2048 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
2049 h_method() == nullptr ? "(no method)" : "", p2i(this),
2050 THREAD->name());
2051 }
2052 if (h_method() != nullptr) {
2053 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
2054 JavaCallArguments args; // No arguments
2055 JavaValue result(T_VOID);
2056 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
2057 }
2058 }
2059
2060 // If a class that implements this interface is initialized, is the JVM required
2061 // to first execute a <clinit> method declared in this interface,
2062 // or (if also_check_supers==true) any of the super types of this interface?
2063 //
2064 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
2065 // an interface, then let SC be its superclass and let SI1, ..., SIn
2066 // be all superinterfaces of C (whether direct or indirect) that
2067 // declare at least one non-abstract, non-static method.
2068 //
2069 // So when an interface is initialized, it does not look at its
2070 // supers. But a proper class will ensure that all of its supers have
2071 // run their <clinit> methods, except that it disregards interfaces
2072 // that lack a non-static concrete method (i.e., a default method).
2073 // Therefore, you should probably call this method only when the
2074 // current class is a super of some proper class, not an interface.
2075 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
2076 assert(is_interface(), "must be");
2077
2078 if (!has_nonstatic_concrete_methods()) {
2079 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
2080 return false;
2081 }
2082
2083 // JVMS 5.5. Initialization
2084 // ...If C is an interface that declares a non-abstract,
2085 // non-static method, the initialization of a class that
2086 // implements C directly or indirectly.
2087 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
2088 return true;
2089 }
2090 if (also_check_supers) {
2091 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2092 for (int i = 0; i < all_ifs->length(); ++i) {
2093 InstanceKlass* super_intf = all_ifs->at(i);
2094 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
2095 return true;
2096 }
2097 }
2098 }
2099 return false;
2100 }
2101
2102 void InstanceKlass::mask_for(const methodHandle& method, int bci,
2103 InterpreterOopMap* entry_for) {
2104 // Lazily create the _oop_map_cache at first request.
2105 // Load_acquire is needed to safely get instance published with CAS by another thread.
2106 OopMapCache* oop_map_cache = AtomicAccess::load_acquire(&_oop_map_cache);
2107 if (oop_map_cache == nullptr) {
2108 // Try to install new instance atomically.
2109 oop_map_cache = new OopMapCache();
2110 OopMapCache* other = AtomicAccess::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
2111 if (other != nullptr) {
2112 // Someone else managed to install before us, ditch local copy and use the existing one.
2113 delete oop_map_cache;
2114 oop_map_cache = other;
2115 }
2116 }
2117 // _oop_map_cache is constant after init; lookup below does its own locking.
2118 oop_map_cache->lookup(method, bci, entry_for);
2119 }
2120
2121
2122 FieldInfo InstanceKlass::field(int index) const {
2123 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2124 if (fs.index() == index) {
2125 return fs.to_FieldInfo();
2126 }
2127 }
2128 fatal("Field not found");
2129 return FieldInfo();
2130 }
2131
2132 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2133 JavaFieldStream fs(this);
2134 if (fs.lookup(name, sig)) {
2135 assert(fs.name() == name, "name must match");
2136 assert(fs.signature() == sig, "signature must match");
2137 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2138 return true;
2139 }
2140 return false;
2141 }
2142
2143
2144 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2145 const int n = local_interfaces()->length();
2146 for (int i = 0; i < n; i++) {
2147 InstanceKlass* intf1 = local_interfaces()->at(i);
2148 assert(intf1->is_interface(), "just checking type");
2149 // search for field in current interface
2150 if (intf1->find_local_field(name, sig, fd)) {
2151 assert(fd->is_static(), "interface field must be static");
2152 return intf1;
2153 }
2154 // search for field in direct superinterfaces
2155 Klass* intf2 = intf1->find_interface_field(name, sig, fd);
2156 if (intf2 != nullptr) return intf2;
2157 }
2158 // otherwise field lookup fails
2159 return nullptr;
2160 }
2161
2162
2163 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2164 // search order according to newest JVM spec (5.4.3.2, p.167).
2165 // 1) search for field in current klass
2166 if (find_local_field(name, sig, fd)) {
2167 return const_cast<InstanceKlass*>(this);
2168 }
2169 // 2) search for field recursively in direct superinterfaces
2170 { Klass* intf = find_interface_field(name, sig, fd);
2171 if (intf != nullptr) return intf;
2172 }
2173 // 3) apply field lookup recursively if superclass exists
2174 { InstanceKlass* supr = super();
2175 if (supr != nullptr) return supr->find_field(name, sig, fd);
2176 }
2177 // 4) otherwise field lookup fails
2178 return nullptr;
2179 }
2180
2181
2182 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
2183 // search order according to newest JVM spec (5.4.3.2, p.167).
2184 // 1) search for field in current klass
2185 if (find_local_field(name, sig, fd)) {
2186 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
2187 }
2188 // 2) search for field recursively in direct superinterfaces
2189 if (is_static) {
2190 Klass* intf = find_interface_field(name, sig, fd);
2191 if (intf != nullptr) return intf;
2192 }
2193 // 3) apply field lookup recursively if superclass exists
2194 { InstanceKlass* supr = super();
2195 if (supr != nullptr) return supr->find_field(name, sig, is_static, fd);
2196 }
2197 // 4) otherwise field lookup fails
2198 return nullptr;
2199 }
2200
2201 bool InstanceKlass::contains_field_offset(int offset) {
2202 if (this->is_inline_klass()) {
2203 InlineKlass* vk = InlineKlass::cast(this);
2204 return offset >= vk->payload_offset() && offset < (vk->payload_offset() + vk->payload_size_in_bytes());
2205 } else {
2206 fieldDescriptor fd;
2207 return find_field_from_offset(offset, false, &fd);
2208 }
2209 }
2210
2211 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2212 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2213 if (fs.offset() == offset) {
2214 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2215 if (fd->is_static() == is_static) return true;
2216 }
2217 }
2218 return false;
2219 }
2220
2221
2222 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2223 const InstanceKlass* klass = this;
2224 while (klass != nullptr) {
2225 if (klass->find_local_field_from_offset(offset, is_static, fd)) {
2226 return true;
2227 }
2228 klass = klass->super();
2229 }
2230 return false;
2231 }
2232
2233 bool InstanceKlass::find_local_flat_field_containing_offset(int offset, fieldDescriptor* fd) const {
2234 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2235 if (!fs.is_flat()) {
2236 continue;
2237 }
2238
2239 if (fs.offset() > offset) {
2240 continue;
2241 }
2242
2243 const int offset_in_flat_field = offset - fs.offset();
2244 const InlineLayoutInfo layout_info = inline_layout_info(fs.index());
2245 const int field_size = layout_info.klass()->layout_size_in_bytes(layout_info.kind());
2246
2247 assert(LayoutKindHelper::is_flat(layout_info.kind()), "Must be flat");
2248
2249 if (offset_in_flat_field < field_size) {
2250 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2251 assert(!fd->is_static(), "Static fields are not flattened");
2252
2253 return true;
2254 }
2255 }
2256
2257 return false;
2258 }
2259
2260 bool InstanceKlass::find_flat_field_containing_offset(int offset, fieldDescriptor* fd) const {
2261 const InstanceKlass* klass = this;
2262 while (klass != nullptr) {
2263 if (klass->find_local_flat_field_containing_offset(offset, fd)) {
2264 return true;
2265 }
2266
2267 klass = klass->super();
2268 }
2269
2270 return false;
2271 }
2272
2273 void InstanceKlass::methods_do(void f(Method* method)) {
2274 // Methods aren't stable until they are loaded. This can be read outside
2275 // a lock through the ClassLoaderData for profiling
2276 // Redefined scratch classes are on the list and need to be cleaned
2277 if (!is_loaded() && !is_scratch_class()) {
2278 return;
2279 }
2280
2281 int len = methods()->length();
2282 for (int index = 0; index < len; index++) {
2283 Method* m = methods()->at(index);
2284 assert(m->is_method(), "must be method");
2285 f(m);
2286 }
2287 }
2288
2289
2290 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
2291 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2292 if (fs.access_flags().is_static()) {
2293 fieldDescriptor& fd = fs.field_descriptor();
2294 cl->do_field(&fd);
2295 }
2296 }
2297 }
2298
2299
2300 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
2301 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2302 if (fs.access_flags().is_static()) {
2303 fieldDescriptor& fd = fs.field_descriptor();
2304 f(&fd, mirror, CHECK);
2305 }
2306 }
2307 }
2308
2309 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
2310 InstanceKlass* super = this->super();
2311 if (super != nullptr) {
2312 super->do_nonstatic_fields(cl);
2313 }
2314 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2315 fieldDescriptor& fd = fs.field_descriptor();
2316 if (!fd.is_static()) {
2317 cl->do_field(&fd);
2318 }
2319 }
2320 }
2321
2322 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
2323 return a->offset() - b->offset();
2324 }
2325
2326 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
2327 InstanceKlass* super = this->super();
2328 if (super != nullptr) {
2329 super->print_nonstatic_fields(cl);
2330 }
2331 ResourceMark rm;
2332 // In DebugInfo nonstatic fields are sorted by offset.
2333 GrowableArray<FieldInfo> fields_sorted;
2334 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2335 if (!fs.access_flags().is_static()) {
2336 fields_sorted.push(fs.to_FieldInfo());
2337 }
2338 }
2339 int length = fields_sorted.length();
2340 if (length > 0) {
2341 fields_sorted.sort(compare_fields_by_offset);
2342 fieldDescriptor fd;
2343 for (int i = 0; i < length; i++) {
2344 fd.reinitialize(this, fields_sorted.at(i));
2345 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
2346 cl->do_field(&fd);
2347 }
2348 }
2349 }
2350
2351 #ifdef ASSERT
2352 static int linear_search(const Array<Method*>* methods,
2353 const Symbol* name,
2354 const Symbol* signature) {
2355 const int len = methods->length();
2356 for (int index = 0; index < len; index++) {
2357 const Method* const m = methods->at(index);
2358 assert(m->is_method(), "must be method");
2359 if (m->signature() == signature && m->name() == name) {
2360 return index;
2361 }
2362 }
2363 return -1;
2364 }
2365 #endif
2366
2367 bool InstanceKlass::_disable_method_binary_search = false;
2368
2369 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2370 int len = methods->length();
2371 int l = 0;
2372 int h = len - 1;
2373 while (l <= h) {
2374 Method* m = methods->at(l);
2375 if (m->name() == name) {
2376 return l;
2377 }
2378 l++;
2379 }
2380 return -1;
2381 }
2382
2383 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2384 if (_disable_method_binary_search) {
2385 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2386 // At the final stage of dynamic dumping, the methods array may not be sorted
2387 // by ascending addresses of their names, so we can't use binary search anymore.
2388 // However, methods with the same name are still laid out consecutively inside the
2389 // methods array, so let's look for the first one that matches.
2390 return linear_search(methods, name);
2391 }
2392
2393 int len = methods->length();
2394 int l = 0;
2395 int h = len - 1;
2396
2397 // methods are sorted by ascending addresses of their names, so do binary search
2398 while (l <= h) {
2399 int mid = (l + h) >> 1;
2400 Method* m = methods->at(mid);
2401 assert(m->is_method(), "must be method");
2402 int res = m->name()->fast_compare(name);
2403 if (res == 0) {
2404 return mid;
2405 } else if (res < 0) {
2406 l = mid + 1;
2407 } else {
2408 h = mid - 1;
2409 }
2410 }
2411 return -1;
2412 }
2413
2414 // find_method looks up the name/signature in the local methods array
2415 Method* InstanceKlass::find_method(const Symbol* name,
2416 const Symbol* signature) const {
2417 return find_method_impl(name, signature,
2418 OverpassLookupMode::find,
2419 StaticLookupMode::find,
2420 PrivateLookupMode::find);
2421 }
2422
2423 Method* InstanceKlass::find_method_impl(const Symbol* name,
2424 const Symbol* signature,
2425 OverpassLookupMode overpass_mode,
2426 StaticLookupMode static_mode,
2427 PrivateLookupMode private_mode) const {
2428 return InstanceKlass::find_method_impl(methods(),
2429 name,
2430 signature,
2431 overpass_mode,
2432 static_mode,
2433 private_mode);
2434 }
2435
2436 // find_instance_method looks up the name/signature in the local methods array
2437 // and skips over static methods
2438 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2439 const Symbol* name,
2440 const Symbol* signature,
2441 PrivateLookupMode private_mode) {
2442 Method* const meth = InstanceKlass::find_method_impl(methods,
2443 name,
2444 signature,
2445 OverpassLookupMode::find,
2446 StaticLookupMode::skip,
2447 private_mode);
2448 assert(((meth == nullptr) || !meth->is_static()),
2449 "find_instance_method should have skipped statics");
2450 return meth;
2451 }
2452
2453 // find_instance_method looks up the name/signature in the local methods array
2454 // and skips over static methods
2455 Method* InstanceKlass::find_instance_method(const Symbol* name,
2456 const Symbol* signature,
2457 PrivateLookupMode private_mode) const {
2458 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2459 }
2460
2461 // Find looks up the name/signature in the local methods array
2462 // and filters on the overpass, static and private flags
2463 // This returns the first one found
2464 // note that the local methods array can have up to one overpass, one static
2465 // and one instance (private or not) with the same name/signature
2466 Method* InstanceKlass::find_local_method(const Symbol* name,
2467 const Symbol* signature,
2468 OverpassLookupMode overpass_mode,
2469 StaticLookupMode static_mode,
2470 PrivateLookupMode private_mode) const {
2471 return InstanceKlass::find_method_impl(methods(),
2472 name,
2473 signature,
2474 overpass_mode,
2475 static_mode,
2476 private_mode);
2477 }
2478
2479 // Find looks up the name/signature in the local methods array
2480 // and filters on the overpass, static and private flags
2481 // This returns the first one found
2482 // note that the local methods array can have up to one overpass, one static
2483 // and one instance (private or not) with the same name/signature
2484 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2485 const Symbol* name,
2486 const Symbol* signature,
2487 OverpassLookupMode overpass_mode,
2488 StaticLookupMode static_mode,
2489 PrivateLookupMode private_mode) {
2490 return InstanceKlass::find_method_impl(methods,
2491 name,
2492 signature,
2493 overpass_mode,
2494 static_mode,
2495 private_mode);
2496 }
2497
2498 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2499 const Symbol* name,
2500 const Symbol* signature) {
2501 return InstanceKlass::find_method_impl(methods,
2502 name,
2503 signature,
2504 OverpassLookupMode::find,
2505 StaticLookupMode::find,
2506 PrivateLookupMode::find);
2507 }
2508
2509 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2510 const Symbol* name,
2511 const Symbol* signature,
2512 OverpassLookupMode overpass_mode,
2513 StaticLookupMode static_mode,
2514 PrivateLookupMode private_mode) {
2515 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2516 return hit >= 0 ? methods->at(hit): nullptr;
2517 }
2518
2519 // true if method matches signature and conforms to skipping_X conditions.
2520 static bool method_matches(const Method* m,
2521 const Symbol* signature,
2522 bool skipping_overpass,
2523 bool skipping_static,
2524 bool skipping_private) {
2525 return ((m->signature() == signature) &&
2526 (!skipping_overpass || !m->is_overpass()) &&
2527 (!skipping_static || !m->is_static()) &&
2528 (!skipping_private || !m->is_private()));
2529 }
2530
2531 // Used directly for default_methods to find the index into the
2532 // default_vtable_indices, and indirectly by find_method
2533 // find_method_index looks in the local methods array to return the index
2534 // of the matching name/signature. If, overpass methods are being ignored,
2535 // the search continues to find a potential non-overpass match. This capability
2536 // is important during method resolution to prefer a static method, for example,
2537 // over an overpass method.
2538 // There is the possibility in any _method's array to have the same name/signature
2539 // for a static method, an overpass method and a local instance method
2540 // To correctly catch a given method, the search criteria may need
2541 // to explicitly skip the other two. For local instance methods, it
2542 // is often necessary to skip private methods
2543 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2544 const Symbol* name,
2545 const Symbol* signature,
2546 OverpassLookupMode overpass_mode,
2547 StaticLookupMode static_mode,
2548 PrivateLookupMode private_mode) {
2549 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2550 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2551 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2552 const int hit = quick_search(methods, name);
2553 if (hit != -1) {
2554 const Method* const m = methods->at(hit);
2555
2556 // Do linear search to find matching signature. First, quick check
2557 // for common case, ignoring overpasses if requested.
2558 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2559 return hit;
2560 }
2561
2562 // search downwards through overloaded methods
2563 int i;
2564 for (i = hit - 1; i >= 0; --i) {
2565 const Method* const m = methods->at(i);
2566 assert(m->is_method(), "must be method");
2567 if (m->name() != name) {
2568 break;
2569 }
2570 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2571 return i;
2572 }
2573 }
2574 // search upwards
2575 for (i = hit + 1; i < methods->length(); ++i) {
2576 const Method* const m = methods->at(i);
2577 assert(m->is_method(), "must be method");
2578 if (m->name() != name) {
2579 break;
2580 }
2581 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2582 return i;
2583 }
2584 }
2585 // not found
2586 #ifdef ASSERT
2587 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2588 linear_search(methods, name, signature);
2589 assert(-1 == index, "binary search should have found entry %d", index);
2590 #endif
2591 }
2592 return -1;
2593 }
2594
2595 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2596 return find_method_by_name(methods(), name, end);
2597 }
2598
2599 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2600 const Symbol* name,
2601 int* end_ptr) {
2602 assert(end_ptr != nullptr, "just checking");
2603 int start = quick_search(methods, name);
2604 int end = start + 1;
2605 if (start != -1) {
2606 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2607 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2608 *end_ptr = end;
2609 return start;
2610 }
2611 return -1;
2612 }
2613
2614 // uncached_lookup_method searches both the local class methods array and all
2615 // superclasses methods arrays, skipping any overpass methods in superclasses,
2616 // and possibly skipping private methods.
2617 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2618 const Symbol* signature,
2619 OverpassLookupMode overpass_mode,
2620 PrivateLookupMode private_mode) const {
2621 OverpassLookupMode overpass_local_mode = overpass_mode;
2622 const InstanceKlass* klass = this;
2623 while (klass != nullptr) {
2624 Method* const method = klass->find_method_impl(name,
2625 signature,
2626 overpass_local_mode,
2627 StaticLookupMode::find,
2628 private_mode);
2629 if (method != nullptr) {
2630 return method;
2631 }
2632 if (name == vmSymbols::object_initializer_name()) {
2633 break; // <init> is never inherited
2634 }
2635 klass = klass->super();
2636 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2637 }
2638 return nullptr;
2639 }
2640
2641 #ifdef ASSERT
2642 // search through class hierarchy and return true if this class or
2643 // one of the superclasses was redefined
2644 bool InstanceKlass::has_redefined_this_or_super() const {
2645 const InstanceKlass* klass = this;
2646 while (klass != nullptr) {
2647 if (klass->has_been_redefined()) {
2648 return true;
2649 }
2650 klass = klass->super();
2651 }
2652 return false;
2653 }
2654 #endif
2655
2656 // lookup a method in the default methods list then in all transitive interfaces
2657 // Do NOT return private or static methods
2658 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2659 Symbol* signature) const {
2660 Method* m = nullptr;
2661 if (default_methods() != nullptr) {
2662 m = find_method(default_methods(), name, signature);
2663 }
2664 // Look up interfaces
2665 if (m == nullptr) {
2666 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2667 }
2668 return m;
2669 }
2670
2671 // lookup a method in all the interfaces that this class implements
2672 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2673 // They should only be found in the initial InterfaceMethodRef
2674 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2675 Symbol* signature,
2676 DefaultsLookupMode defaults_mode) const {
2677 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2678 int num_ifs = all_ifs->length();
2679 InstanceKlass *ik = nullptr;
2680 for (int i = 0; i < num_ifs; i++) {
2681 ik = all_ifs->at(i);
2682 Method* m = ik->lookup_method(name, signature);
2683 if (m != nullptr && m->is_public() && !m->is_static() &&
2684 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2685 return m;
2686 }
2687 }
2688 return nullptr;
2689 }
2690
2691 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2692 :_st(st), _verbose(verbose) {
2693 ResourceMark rm;
2694 _st->print("%-18s ", "KlassAddr");
2695 _st->print("%-4s ", "Size");
2696 _st->print("%-20s ", "State");
2697 _st->print("%-7s ", "Flags");
2698 _st->print("%-5s ", "ClassName");
2699 _st->cr();
2700 }
2701
2702 void PrintClassClosure::do_klass(Klass* k) {
2703 ResourceMark rm;
2704 // klass pointer
2705 _st->print(PTR_FORMAT " ", p2i(k));
2706 // klass size
2707 _st->print("%4d ", k->size());
2708 // initialization state
2709 if (k->is_instance_klass()) {
2710 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2711 } else {
2712 _st->print("%-20s ","");
2713 }
2714 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2715 char buf[10];
2716 int i = 0;
2717 if (k->has_finalizer()) buf[i++] = 'F';
2718 if (k->is_instance_klass()) {
2719 InstanceKlass* ik = InstanceKlass::cast(k);
2720 if (ik->has_final_method()) buf[i++] = 'f';
2721 if (ik->is_rewritten()) buf[i++] = 'W';
2722 if (ik->is_contended()) buf[i++] = 'C';
2723 if (ik->has_been_redefined()) buf[i++] = 'R';
2724 if (ik->in_aot_cache()) buf[i++] = 'S';
2725 }
2726 buf[i++] = '\0';
2727 _st->print("%-7s ", buf);
2728 // klass name
2729 _st->print("%-5s ", k->external_name());
2730 // end
2731 _st->cr();
2732 if (_verbose) {
2733 k->print_on(_st);
2734 }
2735 }
2736
2737 /* jni_id_for for jfieldIds only */
2738 JNIid* InstanceKlass::jni_id_for(int offset) {
2739 MutexLocker ml(JfieldIdCreation_lock);
2740 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2741 if (probe == nullptr) {
2742 // Allocate new static field identifier
2743 probe = new JNIid(this, offset, jni_ids());
2744 set_jni_ids(probe);
2745 }
2746 return probe;
2747 }
2748
2749 u2 InstanceKlass::enclosing_method_data(int offset) const {
2750 const Array<jushort>* const inner_class_list = inner_classes();
2751 if (inner_class_list == nullptr) {
2752 return 0;
2753 }
2754 const int length = inner_class_list->length();
2755 if (length % inner_class_next_offset == 0) {
2756 return 0;
2757 }
2758 const int index = length - enclosing_method_attribute_size;
2759 assert(offset < enclosing_method_attribute_size, "invalid offset");
2760 return inner_class_list->at(index + offset);
2761 }
2762
2763 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2764 u2 method_index) {
2765 Array<jushort>* inner_class_list = inner_classes();
2766 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2767 int length = inner_class_list->length();
2768 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2769 int index = length - enclosing_method_attribute_size;
2770 inner_class_list->at_put(
2771 index + enclosing_method_class_index_offset, class_index);
2772 inner_class_list->at_put(
2773 index + enclosing_method_method_index_offset, method_index);
2774 }
2775 }
2776
2777 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2778 if (method->is_old() && !method->is_obsolete()) {
2779 // If the method passed in is old (but not obsolete), use the current version.
2780 method = method_with_idnum((int)idnum);
2781 assert(method != nullptr, "old and but not obsolete, so should exist");
2782 }
2783 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2784 AtomicAccess::release_store(&jmeths[idnum + 1], new_id);
2785 return new_id;
2786 }
2787
2788 // Allocate the jmethodID cache.
2789 static jmethodID* create_jmethod_id_cache(size_t size) {
2790 jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2791 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2792 // cache size is stored in element[0], other elements offset by one
2793 jmeths[0] = (jmethodID)size;
2794 return jmeths;
2795 }
2796
2797 // When reading outside a lock, use this.
2798 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2799 return AtomicAccess::load_acquire(&_methods_jmethod_ids);
2800 }
2801
2802 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2803 AtomicAccess::release_store(&_methods_jmethod_ids, jmeths);
2804 }
2805
2806 // Lookup or create a jmethodID.
2807 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2808 int idnum = method->method_idnum();
2809 jmethodID* jmeths = methods_jmethod_ids_acquire();
2810
2811 // We use a double-check locking idiom here because this cache is
2812 // performance sensitive. In the normal system, this cache only
2813 // transitions from null to non-null which is safe because we use
2814 // release_set_methods_jmethod_ids() to advertise the new cache.
2815 // A partially constructed cache should never be seen by a racing
2816 // thread. We also use release_store() to save a new jmethodID
2817 // in the cache so a partially constructed jmethodID should never be
2818 // seen either. Cache reads of existing jmethodIDs proceed without a
2819 // lock, but cache writes of a new jmethodID requires uniqueness and
2820 // creation of the cache itself requires no leaks so a lock is
2821 // acquired in those two cases.
2822 //
2823 // If the RedefineClasses() API has been used, then this cache grows
2824 // in the redefinition safepoint.
2825
2826 if (jmeths == nullptr) {
2827 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2828 jmeths = _methods_jmethod_ids;
2829 // Still null?
2830 if (jmeths == nullptr) {
2831 size_t size = idnum_allocated_count();
2832 assert(size > (size_t)idnum, "should already have space");
2833 jmeths = create_jmethod_id_cache(size);
2834 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2835
2836 // publish jmeths
2837 release_set_methods_jmethod_ids(jmeths);
2838 return new_id;
2839 }
2840 }
2841
2842 jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2843 if (id == nullptr) {
2844 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2845 id = jmeths[idnum + 1];
2846 // Still null?
2847 if (id == nullptr) {
2848 return update_jmethod_id(jmeths, method, idnum);
2849 }
2850 }
2851 return id;
2852 }
2853
2854 void InstanceKlass::update_methods_jmethod_cache() {
2855 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2856 jmethodID* cache = _methods_jmethod_ids;
2857 if (cache != nullptr) {
2858 size_t size = idnum_allocated_count();
2859 size_t old_size = (size_t)cache[0];
2860 if (old_size < size + 1) {
2861 // Allocate a larger one and copy entries to the new one.
2862 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2863 jmethodID* new_cache = create_jmethod_id_cache(size);
2864
2865 for (int i = 1; i <= (int)old_size; i++) {
2866 new_cache[i] = cache[i];
2867 }
2868 _methods_jmethod_ids = new_cache;
2869 FREE_C_HEAP_ARRAY(cache);
2870 }
2871 }
2872 }
2873
2874 // Make a jmethodID for all methods in this class. This makes getting all method
2875 // ids much, much faster with classes with more than 8
2876 // methods, and has a *substantial* effect on performance with jvmti
2877 // code that loads all jmethodIDs for all classes.
2878 void InstanceKlass::make_methods_jmethod_ids() {
2879 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2880 jmethodID* jmeths = _methods_jmethod_ids;
2881 if (jmeths == nullptr) {
2882 jmeths = create_jmethod_id_cache(idnum_allocated_count());
2883 release_set_methods_jmethod_ids(jmeths);
2884 }
2885
2886 int length = methods()->length();
2887 for (int index = 0; index < length; index++) {
2888 Method* m = methods()->at(index);
2889 int idnum = m->method_idnum();
2890 assert(!m->is_old(), "should not have old methods or I'm confused");
2891 jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2892 if (!m->is_overpass() && // skip overpasses
2893 id == nullptr) {
2894 id = Method::make_jmethod_id(class_loader_data(), m);
2895 AtomicAccess::release_store(&jmeths[idnum + 1], id);
2896 }
2897 }
2898 }
2899
2900 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2901 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2902 int idnum = method->method_idnum();
2903 jmethodID* jmeths = methods_jmethod_ids_acquire();
2904 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2905 }
2906
2907 inline DependencyContext InstanceKlass::dependencies() {
2908 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2909 return dep_context;
2910 }
2911
2912 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2913 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2914 }
2915
2916 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2917 assert_lock_strong(CodeCache_lock);
2918 dependencies().add_dependent_nmethod(nm);
2919 }
2920
2921 void InstanceKlass::clean_dependency_context() {
2922 dependencies().clean_unloading_dependents();
2923 }
2924
2925 #ifndef PRODUCT
2926 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2927 dependencies().print_dependent_nmethods(verbose);
2928 }
2929
2930 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2931 return dependencies().is_dependent_nmethod(nm);
2932 }
2933 #endif //PRODUCT
2934
2935 void InstanceKlass::clean_weak_instanceklass_links() {
2936 clean_implementors_list();
2937 clean_method_data();
2938 }
2939
2940 void InstanceKlass::clean_implementors_list() {
2941 assert(is_loader_alive(), "this klass should be live");
2942 if (is_interface()) {
2943 assert (ClassUnloading, "only called for ClassUnloading");
2944 for (;;) {
2945 // Use load_acquire due to competing with inserts
2946 InstanceKlass* volatile* iklass = adr_implementor();
2947 assert(iklass != nullptr, "Klass must not be null");
2948 InstanceKlass* impl = AtomicAccess::load_acquire(iklass);
2949 if (impl != nullptr && !impl->is_loader_alive()) {
2950 // null this field, might be an unloaded instance klass or null
2951 if (AtomicAccess::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2952 // Successfully unlinking implementor.
2953 if (log_is_enabled(Trace, class, unload)) {
2954 ResourceMark rm;
2955 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2956 }
2957 return;
2958 }
2959 } else {
2960 return;
2961 }
2962 }
2963 }
2964 }
2965
2966 void InstanceKlass::clean_method_data() {
2967 for (int m = 0; m < methods()->length(); m++) {
2968 MethodData* mdo = methods()->at(m)->method_data();
2969 if (mdo != nullptr) {
2970 mdo->clean_method_data(/*always_clean*/false);
2971 }
2972 }
2973 }
2974
2975 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2976 Klass::metaspace_pointers_do(it);
2977
2978 if (log_is_enabled(Trace, aot)) {
2979 ResourceMark rm;
2980 log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2981 }
2982
2983 it->push(&_annotations);
2984 it->push((Klass**)&_array_klasses);
2985 if (!is_rewritten()) {
2986 it->push(&_constants, MetaspaceClosure::_writable);
2987 } else {
2988 it->push(&_constants);
2989 }
2990 it->push(&_inner_classes);
2991 #if INCLUDE_JVMTI
2992 it->push(&_previous_versions);
2993 #endif
2994 #if INCLUDE_CDS
2995 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2996 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2997 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2998 // The length check on the _methods is necessary because classes which don't have any
2999 // methods share the Universe::_the_empty_method_array which is in the RO region.
3000 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
3001 // To handle jsr bytecode, new Method* maybe stored into _methods
3002 it->push(&_methods, MetaspaceClosure::_writable);
3003 } else {
3004 #endif
3005 it->push(&_methods);
3006 #if INCLUDE_CDS
3007 }
3008 #endif
3009 it->push(&_default_methods);
3010 it->push(&_local_interfaces);
3011 it->push(&_transitive_interfaces);
3012 it->push(&_method_ordering);
3013 if (!is_rewritten()) {
3014 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
3015 } else {
3016 it->push(&_default_vtable_indices);
3017 }
3018
3019 it->push(&_fieldinfo_stream);
3020 it->push(&_fieldinfo_search_table);
3021 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
3022 it->push(&_fields_status, MetaspaceClosure::_writable);
3023
3024 if (itable_length() > 0) {
3025 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
3026 int method_table_offset_in_words = ioe->offset()/wordSize;
3027 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
3028
3029 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
3030 / itableOffsetEntry::size();
3031
3032 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
3033 if (ioe->interface_klass() != nullptr) {
3034 it->push(ioe->interface_klass_addr());
3035 itableMethodEntry* ime = ioe->first_method_entry(this);
3036 int n = klassItable::method_count_for_interface(ioe->interface_klass());
3037 for (int index = 0; index < n; index ++) {
3038 it->push(ime[index].method_addr());
3039 }
3040 }
3041 }
3042 }
3043
3044 it->push(&_nest_host);
3045 it->push(&_nest_members);
3046 it->push(&_permitted_subclasses);
3047 it->push(&_loadable_descriptors);
3048 it->push(&_acmp_maps_array, MetaspaceClosure::_writable);
3049 it->push(&_record_components);
3050 it->push(&_inline_layout_info_array, MetaspaceClosure::_writable);
3051
3052 if (CDSConfig::is_dumping_full_module_graph() && !defined_by_other_loaders()) {
3053 it->push(&_package_entry);
3054 }
3055 }
3056
3057 #if INCLUDE_CDS
3058 void InstanceKlass::remove_unshareable_info() {
3059
3060 if (is_linked()) {
3061 assert(can_be_verified_at_dumptime(), "must be");
3062 // Remember this so we can avoid walking the hierarchy at runtime.
3063 set_verified_at_dump_time();
3064 }
3065
3066 _misc_flags.set_has_init_deps_processed(false);
3067
3068 Klass::remove_unshareable_info();
3069
3070 if (SystemDictionaryShared::has_class_failed_verification(this)) {
3071 // Classes are attempted to link during dumping and may fail,
3072 // but these classes are still in the dictionary and class list in CLD.
3073 // If the class has failed verification, there is nothing else to remove.
3074 return;
3075 }
3076
3077 // Reset to the 'allocated' state to prevent any premature accessing to
3078 // a shared class at runtime while the class is still being loaded and
3079 // restored. A class' init_state is set to 'loaded' at runtime when it's
3080 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
3081 _init_state = allocated;
3082
3083 { // Otherwise this needs to take out the Compile_lock.
3084 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3085 init_implementor();
3086 }
3087
3088 // Call remove_unshareable_info() on other objects that belong to this class, except
3089 // for constants()->remove_unshareable_info(), which is called in a separate pass in
3090 // ArchiveBuilder::make_klasses_shareable(),
3091
3092 for (int i = 0; i < methods()->length(); i++) {
3093 Method* m = methods()->at(i);
3094 m->remove_unshareable_info();
3095 }
3096
3097 // do array classes also.
3098 if (array_klasses() != nullptr) {
3099 array_klasses()->remove_unshareable_info();
3100 }
3101
3102 // These are not allocated from metaspace. They are safe to set to nullptr.
3103 _source_debug_extension = nullptr;
3104 _dep_context = nullptr;
3105 _osr_nmethods_head = nullptr;
3106 #if INCLUDE_JVMTI
3107 _breakpoints = nullptr;
3108 _previous_versions = nullptr;
3109 _cached_class_file = nullptr;
3110 _jvmti_cached_class_field_map = nullptr;
3111 #endif
3112
3113 _init_thread = nullptr;
3114 _methods_jmethod_ids = nullptr;
3115 _jni_ids = nullptr;
3116 _oop_map_cache = nullptr;
3117 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
3118 // keep _nest_host
3119 } else {
3120 // clear _nest_host to ensure re-load at runtime
3121 _nest_host = nullptr;
3122 }
3123 init_shared_package_entry();
3124 _dep_context_last_cleaned = 0;
3125 DEBUG_ONLY(_shared_class_load_count = 0);
3126
3127 remove_unshareable_flags();
3128
3129 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
3130 }
3131
3132 void InstanceKlass::remove_unshareable_flags() {
3133 // clear all the flags/stats that shouldn't be in the archived version
3134 assert(!is_scratch_class(), "must be");
3135 assert(!has_been_redefined(), "must be");
3136 #if INCLUDE_JVMTI
3137 set_is_being_redefined(false);
3138 #endif
3139 set_has_resolved_methods(false);
3140 }
3141
3142 void InstanceKlass::remove_java_mirror() {
3143 Klass::remove_java_mirror();
3144
3145 // do array classes also.
3146 if (array_klasses() != nullptr) {
3147 array_klasses()->remove_java_mirror();
3148 }
3149 }
3150
3151 void InstanceKlass::init_shared_package_entry() {
3152 assert(CDSConfig::is_dumping_archive(), "must be");
3153 if (!CDSConfig::is_dumping_full_module_graph() || defined_by_other_loaders()) {
3154 _package_entry = nullptr;
3155 }
3156 }
3157
3158 void InstanceKlass::compute_has_loops_flag_for_methods() {
3159 Array<Method*>* methods = this->methods();
3160 for (int index = 0; index < methods->length(); ++index) {
3161 Method* m = methods->at(index);
3162 if (!m->is_overpass()) { // work around JDK-8305771
3163 m->compute_has_loops_flag();
3164 }
3165 }
3166 }
3167
3168 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
3169 PackageEntry* pkg_entry, TRAPS) {
3170 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
3171 // before the InstanceKlass is added to the SystemDictionary. Make
3172 // sure the current state is <loaded.
3173 assert(!is_loaded(), "invalid init state");
3174 assert(!shared_loading_failed(), "Must not try to load failed class again");
3175 set_package(loader_data, pkg_entry, CHECK);
3176 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
3177
3178 if (is_inline_klass()) {
3179 InlineKlass::cast(this)->initialize_calling_convention(CHECK);
3180 }
3181
3182 Array<Method*>* methods = this->methods();
3183 int num_methods = methods->length();
3184 for (int index = 0; index < num_methods; ++index) {
3185 methods->at(index)->restore_unshareable_info(CHECK);
3186 }
3187 #if INCLUDE_JVMTI
3188 if (JvmtiExport::has_redefined_a_class()) {
3189 // Reinitialize vtable because RedefineClasses may have changed some
3190 // entries in this vtable for super classes so the CDS vtable might
3191 // point to old or obsolete entries. RedefineClasses doesn't fix up
3192 // vtables in the shared system dictionary, only the main one.
3193 // It also redefines the itable too so fix that too.
3194 // First fix any default methods that point to a super class that may
3195 // have been redefined.
3196 bool trace_name_printed = false;
3197 adjust_default_methods(&trace_name_printed);
3198 if (verified_at_dump_time()) {
3199 // Initialize vtable and itable for classes which can be verified at dump time.
3200 // Unlinked classes such as old classes with major version < 50 cannot be verified
3201 // at dump time.
3202 vtable().initialize_vtable();
3203 itable().initialize_itable();
3204 }
3205 }
3206 #endif // INCLUDE_JVMTI
3207
3208 // restore constant pool resolved references
3209 constants()->restore_unshareable_info(CHECK);
3210
3211 // Restore acmp_maps java array from the version stored in metadata.
3212 // if it cannot be found in the archive
3213 if (Arguments::is_valhalla_enabled() && has_acmp_maps_offset() && java_mirror()->obj_field(_acmp_maps_offset) == nullptr) {
3214 int acmp_maps_size = _acmp_maps_array->length();
3215 typeArrayOop map = oopFactory::new_intArray(acmp_maps_size, CHECK);
3216 typeArrayHandle map_h(THREAD, map);
3217 for (int i = 0; i < acmp_maps_size; i++) {
3218 map_h->int_at_put(i, _acmp_maps_array->at(i));
3219 }
3220 java_mirror()->obj_field_put(_acmp_maps_offset, map_h());
3221 }
3222
3223 if (array_klasses() != nullptr) {
3224 // To get a consistent list of classes we need MultiArray_lock to ensure
3225 // array classes aren't observed while they are being restored.
3226 RecursiveLocker rl(MultiArray_lock, THREAD);
3227 assert(this == ObjArrayKlass::cast(array_klasses())->bottom_klass(), "sanity");
3228 // Array classes have null protection domain.
3229 // --> see ArrayKlass::complete_create_array_klass()
3230 if (class_loader_data() == nullptr) {
3231 ResourceMark rm(THREAD);
3232 log_debug(cds)(" loader_data %s ", loader_data == nullptr ? "nullptr" : "non null");
3233 log_debug(cds)(" this %s array_klasses %s ", this->name()->as_C_string(), array_klasses()->name()->as_C_string());
3234 }
3235 assert(!array_klasses()->is_refined_objArray_klass(), "must be non-refined objarrayklass");
3236 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
3237 }
3238
3239 // Initialize @ValueBased class annotation if not already set in the archived klass.
3240 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
3241 set_is_value_based();
3242 }
3243
3244 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
3245 }
3246
3247 bool InstanceKlass::can_be_verified_at_dumptime() const {
3248 if (CDSConfig::is_dumping_dynamic_archive() && AOTMetaspace::in_aot_cache(this)) {
3249 // This is a class that was dumped into the base archive, so we know
3250 // it was verified at dump time.
3251 return true;
3252 }
3253
3254 if (CDSConfig::is_preserving_verification_constraints()) {
3255 return true;
3256 }
3257
3258 if (CDSConfig::is_old_class_for_verifier(this)) {
3259 // The old verifier does not save verification constraints, so at run time
3260 // SystemDictionaryShared::check_verification_constraints() will not work for this class.
3261 return false;
3262 }
3263 if (super() != nullptr && !super()->can_be_verified_at_dumptime()) {
3264 return false;
3265 }
3266 Array<InstanceKlass*>* interfaces = local_interfaces();
3267 int len = interfaces->length();
3268 for (int i = 0; i < len; i++) {
3269 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
3270 return false;
3271 }
3272 }
3273 return true;
3274 }
3275
3276 #endif // INCLUDE_CDS
3277
3278 #if INCLUDE_JVMTI
3279 static void clear_all_breakpoints(Method* m) {
3280 m->clear_all_breakpoints();
3281 }
3282 #endif
3283
3284 void InstanceKlass::unload_class(InstanceKlass* ik) {
3285
3286 if (ik->is_scratch_class()) {
3287 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
3288 return;
3289 }
3290 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
3291
3292 // Release dependencies.
3293 ik->dependencies().remove_all_dependents();
3294
3295 // notify the debugger
3296 if (JvmtiExport::should_post_class_unload()) {
3297 JvmtiExport::post_class_unload(ik);
3298 }
3299
3300 // notify ClassLoadingService of class unload
3301 ClassLoadingService::notify_class_unloaded(ik);
3302
3303 SystemDictionaryShared::handle_class_unloading(ik);
3304
3305 if (log_is_enabled(Info, class, unload)) {
3306 ResourceMark rm;
3307 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
3308 }
3309
3310 Events::log_class_unloading(Thread::current(), ik);
3311
3312 #if INCLUDE_JFR
3313 assert(ik != nullptr, "invariant");
3314 EventClassUnload event;
3315 event.set_unloadedClass(ik);
3316 event.set_definingClassLoader(ik->class_loader_data());
3317 event.commit();
3318 #endif
3319 }
3320
3321 static void method_release_C_heap_structures(Method* m) {
3322 m->release_C_heap_structures();
3323 }
3324
3325 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
3326 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
3327 // Clean up C heap
3328 Klass::release_C_heap_structures();
3329
3330 // Deallocate and call destructors for MDO mutexes
3331 if (release_sub_metadata) {
3332 methods_do(method_release_C_heap_structures);
3333 }
3334
3335 // Deallocate oop map cache
3336 if (_oop_map_cache != nullptr) {
3337 delete _oop_map_cache;
3338 _oop_map_cache = nullptr;
3339 }
3340
3341 // Deallocate JNI identifiers for jfieldIDs
3342 JNIid::deallocate(jni_ids());
3343 set_jni_ids(nullptr);
3344
3345 jmethodID* jmeths = _methods_jmethod_ids;
3346 if (jmeths != nullptr) {
3347 release_set_methods_jmethod_ids(nullptr);
3348 FreeHeap(jmeths);
3349 }
3350
3351 assert(_dep_context == nullptr,
3352 "dependencies should already be cleaned");
3353
3354 #if INCLUDE_JVMTI
3355 // Deallocate breakpoint records
3356 if (breakpoints() != nullptr) {
3357 methods_do(clear_all_breakpoints);
3358 assert(breakpoints() == nullptr, "should have cleared breakpoints");
3359 }
3360
3361 // deallocate the cached class file
3362 if (_cached_class_file != nullptr) {
3363 os::free(_cached_class_file);
3364 _cached_class_file = nullptr;
3365 }
3366 #endif
3367
3368 FREE_C_HEAP_ARRAY(_source_debug_extension);
3369
3370 if (release_sub_metadata) {
3371 constants()->release_C_heap_structures();
3372 }
3373 }
3374
3375 // The constant pool is on stack if any of the methods are executing or
3376 // referenced by handles.
3377 bool InstanceKlass::on_stack() const {
3378 return _constants->on_stack();
3379 }
3380
3381 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
3382 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
3383 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3384
3385 // minor and major version numbers of class file
3386 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
3387 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3388 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
3389 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3390
3391 bool InstanceKlass::supports_inline_types() const {
3392 return major_version() >= Verifier::VALUE_TYPES_MAJOR_VERSION && minor_version() == Verifier::JAVA_PREVIEW_MINOR_VERSION;
3393 }
3394
3395 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
3396 for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3397 if (ik->constants()->version() == version) {
3398 return ik;
3399 }
3400 }
3401 return nullptr;
3402 }
3403
3404 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3405 if (array == nullptr) {
3406 _source_debug_extension = nullptr;
3407 } else {
3408 // Adding one to the attribute length in order to store a null terminator
3409 // character could cause an overflow because the attribute length is
3410 // already coded with an u4 in the classfile, but in practice, it's
3411 // unlikely to happen.
3412 assert((length+1) > length, "Overflow checking");
3413 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3414 for (int i = 0; i < length; i++) {
3415 sde[i] = array[i];
3416 }
3417 sde[length] = '\0';
3418 _source_debug_extension = sde;
3419 }
3420 }
3421
3422 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3423 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3424 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3425
3426 const char* InstanceKlass::signature_name() const {
3427 // Get the internal name as a c string
3428 const char* src = (const char*) (name()->as_C_string());
3429 const int src_length = (int)strlen(src);
3430
3431 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3432
3433 // Add L as type indicator
3434 int dest_index = 0;
3435 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3436
3437 // Add the actual class name
3438 for (int src_index = 0; src_index < src_length; ) {
3439 dest[dest_index++] = src[src_index++];
3440 }
3441
3442 if (is_hidden()) { // Replace the last '+' with a '.'.
3443 for (int index = (int)src_length; index > 0; index--) {
3444 if (dest[index] == '+') {
3445 dest[index] = JVM_SIGNATURE_DOT;
3446 break;
3447 }
3448 }
3449 }
3450
3451 // Add the semicolon and the null
3452 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3453 dest[dest_index] = '\0';
3454 return dest;
3455 }
3456
3457 ModuleEntry* InstanceKlass::module() const {
3458 if (is_hidden() &&
3459 in_unnamed_package() &&
3460 class_loader_data()->has_class_mirror_holder()) {
3461 // For a non-strong hidden class defined to an unnamed package,
3462 // its (class held) CLD will not have an unnamed module created for it.
3463 // Two choices to find the correct ModuleEntry:
3464 // 1. If hidden class is within a nest, use nest host's module
3465 // 2. Find the unnamed module off from the class loader
3466 // For now option #2 is used since a nest host is not set until
3467 // after the instance class is created in jvm_lookup_define_class().
3468 if (class_loader_data()->is_boot_class_loader_data()) {
3469 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3470 } else {
3471 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3472 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3473 return java_lang_Module::module_entry(module);
3474 }
3475 }
3476
3477 // Class is in a named package
3478 if (!in_unnamed_package()) {
3479 return _package_entry->module();
3480 }
3481
3482 // Class is in an unnamed package, return its loader's unnamed module
3483 return class_loader_data()->unnamed_module();
3484 }
3485
3486 bool InstanceKlass::in_javabase_module() const {
3487 return module()->name() == vmSymbols::java_base();
3488 }
3489
3490 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3491
3492 // ensure java/ packages only loaded by boot or platform builtin loaders
3493 // not needed for shared class since CDS does not archive prohibited classes.
3494 if (!in_aot_cache()) {
3495 check_prohibited_package(name(), loader_data, CHECK);
3496 }
3497
3498 if (in_aot_cache() && _package_entry != nullptr) {
3499 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3500 // we can use the saved package
3501 assert(AOTMetaspace::in_aot_cache(_package_entry), "must be");
3502 return;
3503 } else {
3504 _package_entry = nullptr;
3505 }
3506 }
3507
3508 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3509 // it returns, so we need to decrement it when the current function exits.
3510 TempNewSymbol from_class_name =
3511 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3512
3513 Symbol* pkg_name;
3514 if (pkg_entry != nullptr) {
3515 pkg_name = pkg_entry->name();
3516 } else {
3517 pkg_name = from_class_name;
3518 }
3519
3520 if (pkg_name != nullptr && loader_data != nullptr) {
3521
3522 // Find in class loader's package entry table.
3523 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3524
3525 // If the package name is not found in the loader's package
3526 // entry table, it is an indication that the package has not
3527 // been defined. Consider it defined within the unnamed module.
3528 if (_package_entry == nullptr) {
3529
3530 if (!ModuleEntryTable::javabase_defined()) {
3531 // Before java.base is defined during bootstrapping, define all packages in
3532 // the java.base module. If a non-java.base package is erroneously placed
3533 // in the java.base module it will be caught later when java.base
3534 // is defined by ModuleEntryTable::verify_javabase_packages check.
3535 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3536 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3537 } else {
3538 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3539 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3540 }
3541
3542 // A package should have been successfully created
3543 DEBUG_ONLY(ResourceMark rm(THREAD));
3544 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3545 name()->as_C_string(), loader_data->loader_name_and_id());
3546 }
3547
3548 if (log_is_enabled(Debug, module)) {
3549 ResourceMark rm(THREAD);
3550 ModuleEntry* m = _package_entry->module();
3551 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3552 external_name(),
3553 pkg_name->as_C_string(),
3554 loader_data->loader_name_and_id(),
3555 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3556 }
3557 } else {
3558 ResourceMark rm(THREAD);
3559 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3560 external_name(),
3561 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3562 UNNAMED_MODULE);
3563 }
3564 }
3565
3566 // Function set_classpath_index ensures that for a non-null _package_entry
3567 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3568 // It then sets the classpath_index in the package entry record.
3569 //
3570 // The classpath_index field is used to find the entry on the boot loader class
3571 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3572 // in an unnamed module. It is also used to indicate (for all packages whose
3573 // classes are loaded by the boot loader) that at least one of the package's
3574 // classes has been loaded.
3575 void InstanceKlass::set_classpath_index(s2 path_index) {
3576 if (_package_entry != nullptr) {
3577 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3578 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3579 assert(path_index != -1, "Unexpected classpath_index");
3580 _package_entry->set_classpath_index(path_index);
3581 }
3582 }
3583
3584 // different versions of is_same_class_package
3585
3586 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3587 oop classloader1 = this->class_loader();
3588 PackageEntry* classpkg1 = this->package();
3589 if (class2->is_objArray_klass()) {
3590 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3591 }
3592
3593 oop classloader2;
3594 PackageEntry* classpkg2;
3595 if (class2->is_instance_klass()) {
3596 classloader2 = class2->class_loader();
3597 classpkg2 = class2->package();
3598 } else {
3599 assert(class2->is_typeArray_klass(), "should be type array");
3600 classloader2 = nullptr;
3601 classpkg2 = nullptr;
3602 }
3603
3604 // Same package is determined by comparing class loader
3605 // and package entries. Both must be the same. This rule
3606 // applies even to classes that are defined in the unnamed
3607 // package, they still must have the same class loader.
3608 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3609 return true;
3610 }
3611
3612 return false;
3613 }
3614
3615 // return true if this class and other_class are in the same package. Classloader
3616 // and classname information is enough to determine a class's package
3617 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3618 const Symbol* other_class_name) const {
3619 if (class_loader() != other_class_loader) {
3620 return false;
3621 }
3622 if (name()->fast_compare(other_class_name) == 0) {
3623 return true;
3624 }
3625
3626 {
3627 ResourceMark rm;
3628
3629 bool bad_class_name = false;
3630 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3631 if (bad_class_name) {
3632 return false;
3633 }
3634 // Check that package_from_class_name() returns null, not "", if there is no package.
3635 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3636
3637 const Symbol* const this_package_name =
3638 this->package() != nullptr ? this->package()->name() : nullptr;
3639
3640 if (this_package_name == nullptr || other_pkg == nullptr) {
3641 // One of the two doesn't have a package. Only return true if the other
3642 // one also doesn't have a package.
3643 return this_package_name == other_pkg;
3644 }
3645
3646 // Check if package is identical
3647 return this_package_name->fast_compare(other_pkg) == 0;
3648 }
3649 }
3650
3651 static bool is_prohibited_package_slow(Symbol* class_name) {
3652 // Caller has ResourceMark
3653 int length;
3654 jchar* unicode = class_name->as_unicode(length);
3655 return (length >= 5 &&
3656 unicode[0] == 'j' &&
3657 unicode[1] == 'a' &&
3658 unicode[2] == 'v' &&
3659 unicode[3] == 'a' &&
3660 unicode[4] == '/');
3661 }
3662
3663 // Only boot and platform class loaders can define classes in "java/" packages.
3664 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3665 ClassLoaderData* loader_data,
3666 TRAPS) {
3667 if (!loader_data->is_boot_class_loader_data() &&
3668 !loader_data->is_platform_class_loader_data() &&
3669 class_name != nullptr && class_name->utf8_length() >= 5) {
3670 ResourceMark rm(THREAD);
3671 bool prohibited;
3672 const u1* base = class_name->base();
3673 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3674 prohibited = is_prohibited_package_slow(class_name);
3675 } else {
3676 char* name = class_name->as_C_string();
3677 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3678 }
3679 if (prohibited) {
3680 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3681 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3682 char* name = pkg_name->as_C_string();
3683 const char* class_loader_name = loader_data->loader_name_and_id();
3684 StringUtils::replace_no_expand(name, "/", ".");
3685 const char* msg_text1 = "Class loader (instance of): ";
3686 const char* msg_text2 = " tried to load prohibited package name: ";
3687 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3688 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3689 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3690 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3691 }
3692 }
3693 return;
3694 }
3695
3696 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3697 constantPoolHandle i_cp(THREAD, constants());
3698 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3699 int ioff = iter.inner_class_info_index();
3700 if (ioff != 0) {
3701 // Check to see if the name matches the class we're looking for
3702 // before attempting to find the class.
3703 if (i_cp->klass_name_at_matches(this, ioff)) {
3704 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3705 if (this == inner_klass) {
3706 *ooff = iter.outer_class_info_index();
3707 *noff = iter.inner_name_index();
3708 return true;
3709 }
3710 }
3711 }
3712 }
3713 return false;
3714 }
3715
3716 void InstanceKlass::check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS) {
3717 assert(type->is_instance_klass(), "Sanity check");
3718 if (type->is_identity_class()) {
3719 ResourceMark rm(THREAD);
3720 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3721 err_msg("Class %s expects class %s to be a value class, but it is an identity class",
3722 container_klass_name->as_C_string(),
3723 type->external_name()));
3724 }
3725
3726 if (type->is_abstract()) {
3727 ResourceMark rm(THREAD);
3728 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3729 err_msg("Class %s expects class %s to be concrete value type, but it is an abstract class",
3730 container_klass_name->as_C_string(),
3731 type->external_name()));
3732 }
3733 }
3734
3735 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3736 InstanceKlass* outer_klass = nullptr;
3737 *inner_is_member = false;
3738 int ooff = 0, noff = 0;
3739 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3740 if (has_inner_classes_attr) {
3741 constantPoolHandle i_cp(THREAD, constants());
3742 if (ooff != 0) {
3743 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3744 if (!ok->is_instance_klass()) {
3745 // If the outer class is not an instance klass then it cannot have
3746 // declared any inner classes.
3747 ResourceMark rm(THREAD);
3748 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3749 Exceptions::fthrow(
3750 THREAD_AND_LOCATION,
3751 vmSymbols::java_lang_IncompatibleClassChangeError(),
3752 "%s and %s disagree on InnerClasses attribute",
3753 ok->external_name(),
3754 external_name());
3755 return nullptr;
3756 }
3757 outer_klass = InstanceKlass::cast(ok);
3758 *inner_is_member = true;
3759 }
3760 if (nullptr == outer_klass) {
3761 // It may be a local class; try for that.
3762 int encl_method_class_idx = enclosing_method_class_index();
3763 if (encl_method_class_idx != 0) {
3764 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3765 outer_klass = InstanceKlass::cast(ok);
3766 *inner_is_member = false;
3767 }
3768 }
3769 }
3770
3771 // If no inner class attribute found for this class.
3772 if (nullptr == outer_klass) return nullptr;
3773
3774 // Throws an exception if outer klass has not declared k as an inner klass
3775 // We need evidence that each klass knows about the other, or else
3776 // the system could allow a spoof of an inner class to gain access rights.
3777 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3778 return outer_klass;
3779 }
3780
3781 u2 InstanceKlass::compute_modifier_flags() const {
3782 u2 access = access_flags().as_unsigned_short();
3783
3784 // But check if it happens to be member class.
3785 InnerClassesIterator iter(this);
3786 for (; !iter.done(); iter.next()) {
3787 int ioff = iter.inner_class_info_index();
3788 // Inner class attribute can be zero, skip it.
3789 // Strange but true: JVM spec. allows null inner class refs.
3790 if (ioff == 0) continue;
3791
3792 // only look at classes that are already loaded
3793 // since we are looking for the flags for our self.
3794 Symbol* inner_name = constants()->klass_name_at(ioff);
3795 if (name() == inner_name) {
3796 // This is really a member class.
3797 access = iter.inner_access_flags();
3798 break;
3799 }
3800 }
3801 if (!Arguments::is_valhalla_enabled()) {
3802 // Remember to strip ACC_SUPER bit without Valhalla
3803 access &= (~JVM_ACC_SUPER);
3804 }
3805 return access;
3806 }
3807
3808 jint InstanceKlass::jvmti_class_status() const {
3809 jint result = 0;
3810
3811 if (is_linked()) {
3812 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3813 }
3814
3815 if (is_initialized()) {
3816 assert(is_linked(), "Class status is not consistent");
3817 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3818 }
3819 if (is_in_error_state()) {
3820 result |= JVMTI_CLASS_STATUS_ERROR;
3821 }
3822 return result;
3823 }
3824
3825 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3826 bool implements_interface; // initialized by method_at_itable_or_null
3827 Method* m = method_at_itable_or_null(holder, index,
3828 implements_interface); // out parameter
3829 if (m != nullptr) {
3830 assert(implements_interface, "sanity");
3831 return m;
3832 } else if (implements_interface) {
3833 // Throw AbstractMethodError since corresponding itable slot is empty.
3834 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3835 } else {
3836 // If the interface isn't implemented by the receiver class,
3837 // the VM should throw IncompatibleClassChangeError.
3838 ResourceMark rm(THREAD);
3839 stringStream ss;
3840 bool same_module = (module() == holder->module());
3841 ss.print("Receiver class %s does not implement "
3842 "the interface %s defining the method to be called "
3843 "(%s%s%s)",
3844 external_name(), holder->external_name(),
3845 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3846 (same_module) ? "" : "; ",
3847 (same_module) ? "" : holder->class_in_module_of_loader());
3848 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3849 }
3850 }
3851
3852 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3853 klassItable itable(this);
3854 for (int i = 0; i < itable.size_offset_table(); i++) {
3855 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3856 if (offset_entry->interface_klass() == holder) {
3857 implements_interface = true;
3858 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3859 Method* m = ime[index].method();
3860 return m;
3861 }
3862 }
3863 implements_interface = false;
3864 return nullptr; // offset entry not found
3865 }
3866
3867 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3868 assert(is_linked(), "required");
3869 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3870 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3871
3872 int vtable_index = Method::invalid_vtable_index;
3873 Symbol* name = intf_method->name();
3874 Symbol* signature = intf_method->signature();
3875
3876 // First check in default method array
3877 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3878 int index = find_method_index(default_methods(),
3879 name, signature,
3880 Klass::OverpassLookupMode::find,
3881 Klass::StaticLookupMode::find,
3882 Klass::PrivateLookupMode::find);
3883 if (index >= 0) {
3884 vtable_index = default_vtable_indices()->at(index);
3885 }
3886 }
3887 if (vtable_index == Method::invalid_vtable_index) {
3888 // get vtable_index for miranda methods
3889 klassVtable vt = vtable();
3890 vtable_index = vt.index_of_miranda(name, signature);
3891 }
3892 return vtable_index;
3893 }
3894
3895 #if INCLUDE_JVMTI
3896 // update default_methods for redefineclasses for methods that are
3897 // not yet in the vtable due to concurrent subclass define and superinterface
3898 // redefinition
3899 // Note: those in the vtable, should have been updated via adjust_method_entries
3900 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3901 // search the default_methods for uses of either obsolete or EMCP methods
3902 if (default_methods() != nullptr) {
3903 for (int index = 0; index < default_methods()->length(); index ++) {
3904 Method* old_method = default_methods()->at(index);
3905 if (old_method == nullptr || !old_method->is_old()) {
3906 continue; // skip uninteresting entries
3907 }
3908 assert(!old_method->is_deleted(), "default methods may not be deleted");
3909 Method* new_method = old_method->get_new_method();
3910 default_methods()->at_put(index, new_method);
3911
3912 if (log_is_enabled(Info, redefine, class, update)) {
3913 ResourceMark rm;
3914 if (!(*trace_name_printed)) {
3915 log_info(redefine, class, update)
3916 ("adjust: klassname=%s default methods from name=%s",
3917 external_name(), old_method->method_holder()->external_name());
3918 *trace_name_printed = true;
3919 }
3920 log_debug(redefine, class, update, vtables)
3921 ("default method update: %s(%s) ",
3922 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3923 }
3924 }
3925 }
3926 }
3927 #endif // INCLUDE_JVMTI
3928
3929 // On-stack replacement stuff
3930 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3931 assert_lock_strong(NMethodState_lock);
3932 #ifndef PRODUCT
3933 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3934 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3935 "redundant OSR recompilation detected. memory leak in CodeCache!");
3936 #endif
3937 // only one compilation can be active
3938 assert(n->is_osr_method(), "wrong kind of nmethod");
3939 n->set_osr_link(osr_nmethods_head());
3940 set_osr_nmethods_head(n);
3941 // Raise the highest osr level if necessary
3942 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3943
3944 // Get rid of the osr methods for the same bci that have lower levels.
3945 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3946 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3947 if (inv != nullptr && inv->is_in_use()) {
3948 inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3949 }
3950 }
3951 }
3952
3953 // Remove osr nmethod from the list. Return true if found and removed.
3954 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3955 // This is a short non-blocking critical region, so the no safepoint check is ok.
3956 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3957 assert(n->is_osr_method(), "wrong kind of nmethod");
3958 nmethod* last = nullptr;
3959 nmethod* cur = osr_nmethods_head();
3960 int max_level = CompLevel_none; // Find the max comp level excluding n
3961 Method* m = n->method();
3962 // Search for match
3963 bool found = false;
3964 while(cur != nullptr && cur != n) {
3965 if (m == cur->method()) {
3966 // Find max level before n
3967 max_level = MAX2(max_level, cur->comp_level());
3968 }
3969 last = cur;
3970 cur = cur->osr_link();
3971 }
3972 nmethod* next = nullptr;
3973 if (cur == n) {
3974 found = true;
3975 next = cur->osr_link();
3976 if (last == nullptr) {
3977 // Remove first element
3978 set_osr_nmethods_head(next);
3979 } else {
3980 last->set_osr_link(next);
3981 }
3982 }
3983 n->set_osr_link(nullptr);
3984 cur = next;
3985 while (cur != nullptr) {
3986 // Find max level after n
3987 if (m == cur->method()) {
3988 max_level = MAX2(max_level, cur->comp_level());
3989 }
3990 cur = cur->osr_link();
3991 }
3992 m->set_highest_osr_comp_level(max_level);
3993 return found;
3994 }
3995
3996 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3997 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3998 nmethod* osr = osr_nmethods_head();
3999 int found = 0;
4000 while (osr != nullptr) {
4001 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
4002 if (osr->method() == m) {
4003 deopt_scope->mark(osr);
4004 found++;
4005 }
4006 osr = osr->osr_link();
4007 }
4008 return found;
4009 }
4010
4011 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
4012 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
4013 nmethod* osr = osr_nmethods_head();
4014 nmethod* best = nullptr;
4015 while (osr != nullptr) {
4016 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
4017 // There can be a time when a c1 osr method exists but we are waiting
4018 // for a c2 version. When c2 completes its osr nmethod we will trash
4019 // the c1 version and only be able to find the c2 version. However
4020 // while we overflow in the c1 code at back branches we don't want to
4021 // try and switch to the same code as we are already running
4022
4023 if (osr->method() == m &&
4024 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
4025 if (match_level) {
4026 if (osr->comp_level() == comp_level) {
4027 // Found a match - return it.
4028 return osr;
4029 }
4030 } else {
4031 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
4032 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
4033 // Found the best possible - return it.
4034 return osr;
4035 }
4036 best = osr;
4037 }
4038 }
4039 }
4040 osr = osr->osr_link();
4041 }
4042
4043 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
4044 if (best != nullptr && best->comp_level() >= comp_level) {
4045 return best;
4046 }
4047 return nullptr;
4048 }
4049
4050 // -----------------------------------------------------------------------------------------------------
4051 // Printing
4052
4053 #define BULLET " - "
4054
4055 static const char* state_names[] = {
4056 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
4057 };
4058
4059 static void print_vtable(intptr_t* start, int len, outputStream* st) {
4060 for (int i = 0; i < len; i++) {
4061 intptr_t e = start[i];
4062 st->print("%d : " INTPTR_FORMAT, i, e);
4063 if (MetaspaceObj::is_valid((Metadata*)e)) {
4064 st->print(" ");
4065 ((Metadata*)e)->print_value_on(st);
4066 }
4067 st->cr();
4068 }
4069 }
4070
4071 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
4072 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
4073 }
4074
4075 const char* InstanceKlass::init_state_name() const {
4076 return state_names[init_state()];
4077 }
4078
4079 void InstanceKlass::print_class_flags(outputStream* st) const {
4080 AccessFlags flags(compute_modifier_flags());
4081 if (flags.is_public ()) st->print("public ");
4082 if (flags.is_private ()) st->print("private ");
4083 if (flags.is_protected ()) st->print("protected ");
4084 if (flags.is_static ()) st->print("static ");
4085 if (flags.is_final ()) st->print("final ");
4086 if (flags.is_interface ()) st->print("interface ");
4087 if (flags.is_abstract ()) st->print("abstract ");
4088 if (flags.is_annotation()) st->print("annotation ");
4089 if (flags.is_enum ()) st->print("enum ");
4090 if (flags.is_synthetic ()) st->print("synthetic ");
4091 if (Arguments::is_valhalla_enabled()) {
4092 if (flags.is_identity_class()) st->print("identity ");
4093 if (!flags.is_identity_class()) st->print("value " );
4094 }
4095 }
4096
4097 void InstanceKlass::print_on(outputStream* st) const {
4098 assert(is_klass(), "must be klass");
4099 Klass::print_on(st);
4100
4101 st->print(BULLET"instance size: %d", size_helper()); st->cr();
4102 st->print(BULLET"klass size: %d", size()); st->cr();
4103 st->print(BULLET"access: "); print_class_flags(st); st->cr();
4104 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
4105 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
4106 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
4107 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
4108 st->print(BULLET"sub: ");
4109 Klass* sub = subklass();
4110 int n;
4111 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
4112 if (n < MaxSubklassPrintSize) {
4113 sub->print_value_on(st);
4114 st->print(" ");
4115 }
4116 }
4117 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
4118 st->cr();
4119
4120 if (is_interface()) {
4121 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
4122 if (nof_implementors() == 1) {
4123 st->print_cr(BULLET"implementor: ");
4124 st->print(" ");
4125 implementor()->print_value_on(st);
4126 st->cr();
4127 }
4128 }
4129
4130 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
4131 st->print(BULLET"methods: ");
4132 print_array_on(st, methods(), [](outputStream* ost, Method* method) {
4133 method->print_value_on(ost);
4134 });
4135 st->print(BULLET"method ordering: ");
4136 print_array_on(st, method_ordering(), [](outputStream* ost, int i) {
4137 ost->print("%d", i);
4138 });
4139 if (default_methods() != nullptr) {
4140 st->print(BULLET"default_methods: ");
4141 print_array_on(st, default_methods(), [](outputStream* ost, Method* method) {
4142 method->print_value_on(ost);
4143 });
4144 }
4145 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
4146 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
4147 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
4148
4149 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
4150
4151 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
4152 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
4153
4154 if (secondary_supers() != nullptr) {
4155 if (Verbose) {
4156 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
4157 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
4158 for (int i = 0; i < _secondary_supers->length(); i++) {
4159 ResourceMark rm; // for external_name()
4160 Klass* secondary_super = _secondary_supers->at(i);
4161 st->print(BULLET"%2d:", i);
4162 if (is_hashed) {
4163 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
4164 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
4165 st->print(" dist:%02d:", distance);
4166 }
4167 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
4168 }
4169 }
4170 }
4171 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
4172
4173 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
4174 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
4175 if (source_debug_extension() != nullptr) {
4176 st->print(BULLET"source debug extension: ");
4177 st->print("%s", source_debug_extension());
4178 st->cr();
4179 }
4180 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
4181 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
4182 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
4183 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
4184 {
4185 bool have_pv = false;
4186 // previous versions are linked together through the InstanceKlass
4187 for (InstanceKlass* pv_node = previous_versions();
4188 pv_node != nullptr;
4189 pv_node = pv_node->previous_versions()) {
4190 if (!have_pv)
4191 st->print(BULLET"previous version: ");
4192 have_pv = true;
4193 pv_node->constants()->print_value_on(st);
4194 }
4195 if (have_pv) st->cr();
4196 }
4197
4198 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
4199 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
4200 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
4201 print_on_maybe_null(st, BULLET"record components: ", record_components());
4202 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
4203 st->print(BULLET"loadable descriptors: "); loadable_descriptors()->print_value_on(st); st->cr();
4204 if (java_mirror() != nullptr) {
4205 st->print(BULLET"java mirror: ");
4206 java_mirror()->print_value_on(st);
4207 st->cr();
4208 } else {
4209 st->print_cr(BULLET"java mirror: null");
4210 }
4211 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
4212 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
4213 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
4214 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
4215
4216 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
4217 // There is no oop so static and nonstatic printing can use the same printer.
4218 FieldPrinter field_printer(st);
4219 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
4220 ik->do_local_static_fields(&field_printer);
4221 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
4222 ik->print_nonstatic_fields(&field_printer);
4223
4224 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
4225 OopMapBlock* map = start_of_nonstatic_oop_maps();
4226 OopMapBlock* end_map = map + nonstatic_oop_map_count();
4227 while (map < end_map) {
4228 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
4229 map++;
4230 }
4231 st->cr();
4232
4233 if (fieldinfo_search_table() != nullptr) {
4234 st->print_cr(BULLET"---- field info search table:");
4235 FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
4236 }
4237 }
4238
4239 void InstanceKlass::print_value_on(outputStream* st) const {
4240 assert(is_klass(), "must be klass");
4241 if (Verbose || WizardMode) print_class_flags(st);
4242 name()->print_value_on(st);
4243 }
4244
4245 void FieldPrinter::do_field(fieldDescriptor* fd) {
4246 for (int i = 0; i < _indent; i++) _st->print(" ");
4247 _st->print(BULLET);
4248 // Handles the cases of static fields or instance fields but no oop is given.
4249 if (_obj == nullptr) {
4250 fd->print_on(_st, _base_offset);
4251 _st->cr();
4252 } else {
4253 fd->print_on_for(_st, _obj, _indent, _base_offset);
4254 if (!fd->field_flags().is_flat()) _st->cr();
4255 }
4256 }
4257
4258
4259 void InstanceKlass::oop_print_on(oop obj, outputStream* st, int indent, int base_offset) {
4260 Klass::oop_print_on(obj, st);
4261
4262 if (this == vmClasses::String_klass()) {
4263 typeArrayOop value = java_lang_String::value(obj);
4264 juint length = java_lang_String::length(obj);
4265 if (value != nullptr &&
4266 value->is_typeArray() &&
4267 length <= (juint) value->length()) {
4268 st->print(BULLET"string: ");
4269 java_lang_String::print(obj, st);
4270 st->cr();
4271 }
4272 }
4273
4274 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
4275 FieldPrinter print_field(st, obj, indent, base_offset);
4276 print_nonstatic_fields(&print_field);
4277
4278 if (this == vmClasses::Class_klass()) {
4279 st->print(BULLET"signature: ");
4280 java_lang_Class::print_signature(obj, st);
4281 st->cr();
4282 Klass* real_klass = java_lang_Class::as_Klass(obj);
4283 if (real_klass != nullptr && real_klass->is_instance_klass()) {
4284 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
4285 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
4286 }
4287 } else if (this == vmClasses::MethodType_klass()) {
4288 st->print(BULLET"signature: ");
4289 java_lang_invoke_MethodType::print_signature(obj, st);
4290 st->cr();
4291 }
4292 }
4293
4294 #ifndef PRODUCT
4295
4296 bool InstanceKlass::verify_itable_index(int i) {
4297 int method_count = klassItable::method_count_for_interface(this);
4298 assert(i >= 0 && i < method_count, "index out of bounds");
4299 return true;
4300 }
4301
4302 #endif //PRODUCT
4303
4304 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
4305 st->print("a ");
4306 name()->print_value_on(st);
4307 obj->print_address_on(st);
4308 if (this == vmClasses::String_klass()
4309 && java_lang_String::value(obj) != nullptr) {
4310 ResourceMark rm;
4311 int len = java_lang_String::length(obj);
4312 int plen = (len < 24 ? len : 12);
4313 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
4314 st->print(" = \"%s\"", str);
4315 if (len > plen)
4316 st->print("...[%d]", len);
4317 } else if (this == vmClasses::Class_klass()) {
4318 Klass* k = java_lang_Class::as_Klass(obj);
4319 st->print(" = ");
4320 if (k != nullptr) {
4321 k->print_value_on(st);
4322 } else {
4323 const char* tname = type2name(java_lang_Class::primitive_type(obj));
4324 st->print("%s", tname ? tname : "type?");
4325 }
4326 } else if (this == vmClasses::MethodType_klass()) {
4327 st->print(" = ");
4328 java_lang_invoke_MethodType::print_signature(obj, st);
4329 } else if (java_lang_boxing_object::is_instance(obj)) {
4330 st->print(" = ");
4331 java_lang_boxing_object::print(obj, st);
4332 } else if (this == vmClasses::LambdaForm_klass()) {
4333 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
4334 if (vmentry != nullptr) {
4335 st->print(" => ");
4336 vmentry->print_value_on(st);
4337 }
4338 } else if (this == vmClasses::MemberName_klass()) {
4339 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
4340 if (vmtarget != nullptr) {
4341 st->print(" = ");
4342 vmtarget->print_value_on(st);
4343 } else {
4344 oop clazz = java_lang_invoke_MemberName::clazz(obj);
4345 oop name = java_lang_invoke_MemberName::name(obj);
4346 if (clazz != nullptr) {
4347 clazz->print_value_on(st);
4348 } else {
4349 st->print("null");
4350 }
4351 st->print(".");
4352 if (name != nullptr) {
4353 name->print_value_on(st);
4354 } else {
4355 st->print("null");
4356 }
4357 }
4358 }
4359 }
4360
4361 const char* InstanceKlass::internal_name() const {
4362 return external_name();
4363 }
4364
4365 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
4366 const ModuleEntry* module_entry,
4367 const ClassFileStream* cfs) const {
4368
4369 if (ClassListWriter::is_enabled()) {
4370 ClassListWriter::write(this, cfs);
4371 }
4372
4373 print_class_load_helper(loader_data, module_entry, cfs);
4374 print_class_load_cause_logging();
4375 }
4376
4377 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
4378 const ModuleEntry* module_entry,
4379 const ClassFileStream* cfs) const {
4380
4381 if (!log_is_enabled(Info, class, load)) {
4382 return;
4383 }
4384
4385 ResourceMark rm;
4386 LogMessage(class, load) msg;
4387 stringStream info_stream;
4388
4389 // Name and class hierarchy info
4390 info_stream.print("%s", external_name());
4391
4392 // Source
4393 if (cfs != nullptr) {
4394 if (cfs->source() != nullptr) {
4395 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
4396 if (module_name != nullptr) {
4397 // When the boot loader created the stream, it didn't know the module name
4398 // yet. Let's format it now.
4399 if (cfs->from_boot_loader_modules_image()) {
4400 info_stream.print(" source: jrt:/%s", module_name);
4401 } else {
4402 info_stream.print(" source: %s", cfs->source());
4403 }
4404 } else {
4405 info_stream.print(" source: %s", cfs->source());
4406 }
4407 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
4408 Thread* current = Thread::current();
4409 Klass* caller = current->is_Java_thread() ?
4410 JavaThread::cast(current)->security_get_caller_class(1):
4411 nullptr;
4412 // caller can be null, for example, during a JVMTI VM_Init hook
4413 if (caller != nullptr) {
4414 info_stream.print(" source: instance of %s", caller->external_name());
4415 } else {
4416 // source is unknown
4417 }
4418 } else {
4419 oop class_loader = loader_data->class_loader();
4420 info_stream.print(" source: %s", class_loader->klass()->external_name());
4421 }
4422 } else {
4423 assert(this->in_aot_cache(), "must be");
4424 if (AOTMetaspace::in_aot_cache_dynamic_region((void*)this)) {
4425 info_stream.print(" source: shared objects file (top)");
4426 } else {
4427 info_stream.print(" source: shared objects file");
4428 }
4429 }
4430
4431 msg.info("%s", info_stream.as_string());
4432
4433 if (log_is_enabled(Debug, class, load)) {
4434 stringStream debug_stream;
4435
4436 // Class hierarchy info
4437 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4438 p2i(this), p2i(super()));
4439
4440 // Interfaces
4441 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4442 debug_stream.print(" interfaces:");
4443 int length = local_interfaces()->length();
4444 for (int i = 0; i < length; i++) {
4445 debug_stream.print(" " PTR_FORMAT,
4446 p2i(local_interfaces()->at(i)));
4447 }
4448 }
4449
4450 // Class loader
4451 debug_stream.print(" loader: [");
4452 loader_data->print_value_on(&debug_stream);
4453 debug_stream.print("]");
4454
4455 // Classfile checksum
4456 if (cfs) {
4457 debug_stream.print(" bytes: %d checksum: %08x",
4458 cfs->length(),
4459 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4460 cfs->length()));
4461 }
4462
4463 msg.debug("%s", debug_stream.as_string());
4464 }
4465 }
4466
4467 void InstanceKlass::print_class_load_cause_logging() const {
4468 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4469 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4470 JavaThread* current = JavaThread::current();
4471 ResourceMark rm(current);
4472 const char* name = external_name();
4473
4474 if (LogClassLoadingCauseFor == nullptr ||
4475 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4476 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4477 return;
4478 }
4479
4480 // Log Java stack first
4481 {
4482 LogMessage(class, load, cause) msg;
4483 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4484
4485 info_stream.print_cr("Java stack when loading %s:", name);
4486 current->print_stack_on(&info_stream);
4487 }
4488
4489 // Log native stack second
4490 if (log_cause_native) {
4491 // Log to string first so that lines can be indented
4492 stringStream stack_stream;
4493 char buf[O_BUFLEN];
4494 address lastpc = nullptr;
4495 NativeStackPrinter nsp(current);
4496 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4497 true /* print_source_info */, -1 /* max stack */);
4498
4499 LogMessage(class, load, cause, native) msg;
4500 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4501 info_stream.print_cr("Native stack when loading %s:", name);
4502
4503 // Print each native stack line to the log
4504 int size = (int) stack_stream.size();
4505 char* stack = stack_stream.as_string();
4506 char* stack_end = stack + size;
4507 char* line_start = stack;
4508 for (char* p = stack; p < stack_end; p++) {
4509 if (*p == '\n') {
4510 *p = '\0';
4511 info_stream.print_cr("\t%s", line_start);
4512 line_start = p + 1;
4513 }
4514 }
4515 if (line_start < stack_end) {
4516 info_stream.print_cr("\t%s", line_start);
4517 }
4518 }
4519 }
4520 }
4521
4522 // Verification
4523
4524 class VerifyFieldClosure: public BasicOopIterateClosure {
4525 protected:
4526 template <class T> void do_oop_work(T* p) {
4527 oop obj = RawAccess<>::oop_load(p);
4528 if (!oopDesc::is_oop_or_null(obj)) {
4529 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4530 Universe::print_on(tty);
4531 guarantee(false, "boom");
4532 }
4533 }
4534 public:
4535 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4536 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4537 };
4538
4539 void InstanceKlass::verify_on(outputStream* st) {
4540 #ifndef PRODUCT
4541 // Avoid redundant verifies, this really should be in product.
4542 if (_verify_count == Universe::verify_count()) return;
4543 _verify_count = Universe::verify_count();
4544 #endif
4545
4546 // Verify Klass
4547 Klass::verify_on(st);
4548
4549 // Verify that klass is present in ClassLoaderData
4550 guarantee(class_loader_data()->contains_klass(this),
4551 "this class isn't found in class loader data");
4552
4553 // Verify vtables
4554 if (is_linked()) {
4555 // $$$ This used to be done only for m/s collections. Doing it
4556 // always seemed a valid generalization. (DLD -- 6/00)
4557 vtable().verify(st);
4558 }
4559
4560 // Verify first subklass
4561 if (subklass() != nullptr) {
4562 guarantee(subklass()->is_klass(), "should be klass");
4563 }
4564
4565 // Verify siblings
4566 Klass* super = this->super();
4567 Klass* sib = next_sibling();
4568 if (sib != nullptr) {
4569 if (sib == this) {
4570 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4571 }
4572
4573 guarantee(sib->is_klass(), "should be klass");
4574 guarantee(sib->super() == super, "siblings should have same superklass");
4575 }
4576
4577 // Verify local interfaces
4578 if (local_interfaces()) {
4579 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4580 for (int j = 0; j < local_interfaces->length(); j++) {
4581 InstanceKlass* e = local_interfaces->at(j);
4582 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4583 }
4584 }
4585
4586 // Verify transitive interfaces
4587 if (transitive_interfaces() != nullptr) {
4588 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4589 for (int j = 0; j < transitive_interfaces->length(); j++) {
4590 InstanceKlass* e = transitive_interfaces->at(j);
4591 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4592 }
4593 }
4594
4595 // Verify methods
4596 if (methods() != nullptr) {
4597 Array<Method*>* methods = this->methods();
4598 for (int j = 0; j < methods->length(); j++) {
4599 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4600 }
4601 for (int j = 0; j < methods->length() - 1; j++) {
4602 Method* m1 = methods->at(j);
4603 Method* m2 = methods->at(j + 1);
4604 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4605 }
4606 }
4607
4608 // Verify method ordering
4609 if (method_ordering() != nullptr) {
4610 Array<int>* method_ordering = this->method_ordering();
4611 int length = method_ordering->length();
4612 if (JvmtiExport::can_maintain_original_method_order() ||
4613 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4614 guarantee(length == methods()->length(), "invalid method ordering length");
4615 jlong sum = 0;
4616 for (int j = 0; j < length; j++) {
4617 int original_index = method_ordering->at(j);
4618 guarantee(original_index >= 0, "invalid method ordering index");
4619 guarantee(original_index < length, "invalid method ordering index");
4620 sum += original_index;
4621 }
4622 // Verify sum of indices 0,1,...,length-1
4623 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4624 } else {
4625 guarantee(length == 0, "invalid method ordering length");
4626 }
4627 }
4628
4629 // Verify default methods
4630 if (default_methods() != nullptr) {
4631 Array<Method*>* methods = this->default_methods();
4632 for (int j = 0; j < methods->length(); j++) {
4633 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4634 }
4635 for (int j = 0; j < methods->length() - 1; j++) {
4636 Method* m1 = methods->at(j);
4637 Method* m2 = methods->at(j + 1);
4638 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4639 }
4640 }
4641
4642 // Verify JNI static field identifiers
4643 if (jni_ids() != nullptr) {
4644 jni_ids()->verify(this);
4645 }
4646
4647 // Verify other fields
4648 if (constants() != nullptr) {
4649 guarantee(constants()->is_constantPool(), "should be constant pool");
4650 }
4651 }
4652
4653 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4654 Klass::oop_verify_on(obj, st);
4655 VerifyFieldClosure blk;
4656 obj->oop_iterate(&blk);
4657 }
4658
4659 // JNIid class for jfieldIDs only
4660 // Note to reviewers:
4661 // These JNI functions are just moved over to column 1 and not changed
4662 // in the compressed oops workspace.
4663 JNIid::JNIid(InstanceKlass* holder, int offset, JNIid* next) {
4664 _holder = holder;
4665 _offset = offset;
4666 _next = next;
4667 DEBUG_ONLY(_is_static_field_id = false;)
4668 }
4669
4670 JNIid* JNIid::find(int offset) {
4671 JNIid* current = this;
4672 while (current != nullptr) {
4673 if (current->offset() == offset) return current;
4674 current = current->next();
4675 }
4676 return nullptr;
4677 }
4678
4679 void JNIid::deallocate(JNIid* current) {
4680 while (current != nullptr) {
4681 JNIid* next = current->next();
4682 delete current;
4683 current = next;
4684 }
4685 }
4686
4687 void JNIid::verify(InstanceKlass* holder) {
4688 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4689 int end_field_offset;
4690 end_field_offset = first_field_offset + (holder->static_field_size() * wordSize);
4691
4692 JNIid* current = this;
4693 while (current != nullptr) {
4694 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4695 #ifdef ASSERT
4696 int o = current->offset();
4697 if (current->is_static_field_id()) {
4698 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4699 }
4700 #endif
4701 current = current->next();
4702 }
4703 }
4704
4705 void InstanceKlass::set_init_state(ClassState state) {
4706 #ifdef ASSERT
4707 bool good_state = in_aot_cache() ? (_init_state <= state)
4708 : (_init_state < state);
4709 assert(good_state || state == allocated, "illegal state transition");
4710 #endif
4711 assert(_init_thread == nullptr, "should be cleared before state change");
4712 AtomicAccess::release_store(&_init_state, state);
4713 }
4714
4715 #if INCLUDE_JVMTI
4716
4717 // RedefineClasses() support for previous versions
4718
4719 // Globally, there is at least one previous version of a class to walk
4720 // during class unloading, which is saved because old methods in the class
4721 // are still running. Otherwise the previous version list is cleaned up.
4722 bool InstanceKlass::_should_clean_previous_versions = false;
4723
4724 // Returns true if there are previous versions of a class for class
4725 // unloading only. Also resets the flag to false. purge_previous_version
4726 // will set the flag to true if there are any left, i.e., if there's any
4727 // work to do for next time. This is to avoid the expensive code cache
4728 // walk in CLDG::clean_deallocate_lists().
4729 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4730 bool ret = _should_clean_previous_versions;
4731 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4732 ret ? "true" : "false");
4733 _should_clean_previous_versions = false;
4734 return ret;
4735 }
4736
4737 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4738 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4739 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4740 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4741 Array<Method*>* method_refs = klass->methods();
4742 for (int k = 0; k < method_refs->length(); k++) {
4743 Method* method = method_refs->at(k);
4744 // Only need to clear obsolete methods.
4745 if (method != nullptr && method->is_obsolete()) {
4746 method->clear_jmethod_id();
4747 }
4748 }
4749 }
4750
4751 // Purge previous versions before adding new previous versions of the class and
4752 // during class unloading.
4753 void InstanceKlass::purge_previous_version_list() {
4754 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4755 assert(has_been_redefined(), "Should only be called for main class");
4756
4757 // Quick exit.
4758 if (previous_versions() == nullptr) {
4759 return;
4760 }
4761
4762 // This klass has previous versions so see what we can cleanup
4763 // while it is safe to do so.
4764
4765 int deleted_count = 0; // leave debugging breadcrumbs
4766 int live_count = 0;
4767 ClassLoaderData* loader_data = class_loader_data();
4768 assert(loader_data != nullptr, "should never be null");
4769
4770 ResourceMark rm;
4771 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4772
4773 // previous versions are linked together through the InstanceKlass
4774 InstanceKlass* pv_node = previous_versions();
4775 InstanceKlass* last = this;
4776 int version = 0;
4777
4778 // check the previous versions list
4779 for (; pv_node != nullptr; ) {
4780
4781 ConstantPool* pvcp = pv_node->constants();
4782 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4783
4784 if (!pvcp->on_stack()) {
4785 // If the constant pool isn't on stack, none of the methods
4786 // are executing. Unlink this previous_version.
4787 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4788 // so will be deallocated during the next phase of class unloading.
4789 log_trace(redefine, class, iklass, purge)
4790 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4791 // Unlink from previous version list.
4792 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4793 InstanceKlass* next = pv_node->previous_versions();
4794 clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4795 pv_node->link_previous_versions(nullptr); // point next to null
4796 last->link_previous_versions(next);
4797 // Delete this node directly. Nothing is referring to it and we don't
4798 // want it to increase the counter for metadata to delete in CLDG.
4799 MetadataFactory::free_metadata(loader_data, pv_node);
4800 pv_node = next;
4801 deleted_count++;
4802 version++;
4803 continue;
4804 } else {
4805 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4806 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4807 live_count++;
4808 if (pvcp->in_aot_cache()) {
4809 // Shared previous versions can never be removed so no cleaning is needed.
4810 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4811 } else {
4812 // Previous version alive, set that clean is needed for next time.
4813 _should_clean_previous_versions = true;
4814 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4815 }
4816 }
4817
4818 // next previous version
4819 last = pv_node;
4820 pv_node = pv_node->previous_versions();
4821 version++;
4822 }
4823 log_trace(redefine, class, iklass, purge)
4824 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4825 }
4826
4827 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4828 int emcp_method_count) {
4829 int obsolete_method_count = old_methods->length() - emcp_method_count;
4830
4831 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4832 _previous_versions != nullptr) {
4833 // We have a mix of obsolete and EMCP methods so we have to
4834 // clear out any matching EMCP method entries the hard way.
4835 int local_count = 0;
4836 for (int i = 0; i < old_methods->length(); i++) {
4837 Method* old_method = old_methods->at(i);
4838 if (old_method->is_obsolete()) {
4839 // only obsolete methods are interesting
4840 Symbol* m_name = old_method->name();
4841 Symbol* m_signature = old_method->signature();
4842
4843 // previous versions are linked together through the InstanceKlass
4844 int j = 0;
4845 for (InstanceKlass* prev_version = _previous_versions;
4846 prev_version != nullptr;
4847 prev_version = prev_version->previous_versions(), j++) {
4848
4849 Array<Method*>* method_refs = prev_version->methods();
4850 for (int k = 0; k < method_refs->length(); k++) {
4851 Method* method = method_refs->at(k);
4852
4853 if (!method->is_obsolete() &&
4854 method->name() == m_name &&
4855 method->signature() == m_signature) {
4856 // The current RedefineClasses() call has made all EMCP
4857 // versions of this method obsolete so mark it as obsolete
4858 log_trace(redefine, class, iklass, add)
4859 ("%s(%s): flush obsolete method @%d in version @%d",
4860 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4861
4862 method->set_is_obsolete();
4863 break;
4864 }
4865 }
4866
4867 // The previous loop may not find a matching EMCP method, but
4868 // that doesn't mean that we can optimize and not go any
4869 // further back in the PreviousVersion generations. The EMCP
4870 // method for this generation could have already been made obsolete,
4871 // but there still may be an older EMCP method that has not
4872 // been made obsolete.
4873 }
4874
4875 if (++local_count >= obsolete_method_count) {
4876 // no more obsolete methods so bail out now
4877 break;
4878 }
4879 }
4880 }
4881 }
4882 }
4883
4884 // Save the scratch_class as the previous version if any of the methods are running.
4885 // The previous_versions are used to set breakpoints in EMCP methods and they are
4886 // also used to clean MethodData links to redefined methods that are no longer running.
4887 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4888 int emcp_method_count) {
4889 assert(Thread::current()->is_VM_thread(),
4890 "only VMThread can add previous versions");
4891
4892 ResourceMark rm;
4893 log_trace(redefine, class, iklass, add)
4894 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4895
4896 // Clean out old previous versions for this class
4897 purge_previous_version_list();
4898
4899 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4900 // a previous redefinition may be made obsolete by this redefinition.
4901 Array<Method*>* old_methods = scratch_class->methods();
4902 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4903
4904 // If the constant pool for this previous version of the class
4905 // is not marked as being on the stack, then none of the methods
4906 // in this previous version of the class are on the stack so
4907 // we don't need to add this as a previous version.
4908 ConstantPool* cp_ref = scratch_class->constants();
4909 if (!cp_ref->on_stack()) {
4910 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4911 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4912 return;
4913 }
4914
4915 // Add previous version if any methods are still running or if this is
4916 // a shared class which should never be removed.
4917 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4918 scratch_class->link_previous_versions(previous_versions());
4919 link_previous_versions(scratch_class);
4920 if (cp_ref->in_aot_cache()) {
4921 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4922 } else {
4923 // We only set clean_previous_versions flag for processing during class
4924 // unloading for non-shared classes.
4925 _should_clean_previous_versions = true;
4926 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4927 }
4928 } // end add_previous_version()
4929
4930 #endif // INCLUDE_JVMTI
4931
4932 Method* InstanceKlass::method_with_idnum(int idnum) const {
4933 Method* m = nullptr;
4934 if (idnum < methods()->length()) {
4935 m = methods()->at(idnum);
4936 }
4937 if (m == nullptr || m->method_idnum() != idnum) {
4938 for (int index = 0; index < methods()->length(); ++index) {
4939 m = methods()->at(index);
4940 if (m->method_idnum() == idnum) {
4941 return m;
4942 }
4943 }
4944 // None found, return null for the caller to handle.
4945 return nullptr;
4946 }
4947 return m;
4948 }
4949
4950
4951 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4952 if (idnum >= methods()->length()) {
4953 return nullptr;
4954 }
4955 Method* m = methods()->at(idnum);
4956 if (m != nullptr && m->orig_method_idnum() == idnum) {
4957 return m;
4958 }
4959 // Obsolete method idnum does not match the original idnum
4960 for (int index = 0; index < methods()->length(); ++index) {
4961 m = methods()->at(index);
4962 if (m->orig_method_idnum() == idnum) {
4963 return m;
4964 }
4965 }
4966 // None found, return null for the caller to handle.
4967 return nullptr;
4968 }
4969
4970
4971 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4972 const InstanceKlass* holder = get_klass_version(version);
4973 if (holder == nullptr) {
4974 return nullptr; // The version of klass is gone, no method is found
4975 }
4976 return holder->method_with_orig_idnum(idnum);
4977 }
4978
4979 #if INCLUDE_JVMTI
4980 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4981 return _cached_class_file;
4982 }
4983
4984 jint InstanceKlass::get_cached_class_file_len() {
4985 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4986 }
4987
4988 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4989 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4990 }
4991 #endif
4992
4993 // Make a step iterating over the class hierarchy under the root class.
4994 // Skips subclasses if requested.
4995 void ClassHierarchyIterator::next() {
4996 assert(_current != nullptr, "required");
4997 if (_visit_subclasses && _current->subklass() != nullptr) {
4998 _current = _current->subklass();
4999 return; // visit next subclass
5000 }
5001 _visit_subclasses = true; // reset
5002 while (_current->next_sibling() == nullptr && _current != _root) {
5003 _current = _current->java_super(); // backtrack; no more sibling subclasses left
5004 }
5005 if (_current == _root) {
5006 // Iteration is over (back at root after backtracking). Invalidate the iterator.
5007 _current = nullptr;
5008 return;
5009 }
5010 _current = _current->next_sibling();
5011 return; // visit next sibling subclass
5012 }