1 /*
2 * Copyright (c) 1997, 2025, 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/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "klass.inline.hpp"
55 #include "logging/logMessage.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/allocation.inline.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/metadataFactory.hpp"
60 #include "memory/metaspaceClosure.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/fieldStreams.inline.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/instanceClassLoaderKlass.hpp"
67 #include "oops/instanceKlass.inline.hpp"
68 #include "oops/instanceMirrorKlass.hpp"
69 #include "oops/instanceOop.hpp"
70 #include "oops/instanceStackChunkKlass.hpp"
71 #include "oops/klass.inline.hpp"
72 #include "oops/markWord.hpp"
73 #include "oops/method.hpp"
74 #include "oops/oop.inline.hpp"
75 #include "oops/recordComponent.hpp"
76 #include "oops/symbol.hpp"
77 #include "oops/inlineKlass.hpp"
78 #include "oops/refArrayKlass.hpp"
79 #include "prims/jvmtiExport.hpp"
80 #include "prims/jvmtiRedefineClasses.hpp"
81 #include "prims/jvmtiThreadState.hpp"
82 #include "prims/methodComparator.hpp"
83 #include "runtime/arguments.hpp"
84 #include "runtime/deoptimization.hpp"
85 #include "runtime/atomic.hpp"
86 #include "runtime/fieldDescriptor.inline.hpp"
87 #include "runtime/handles.inline.hpp"
88 #include "runtime/javaCalls.hpp"
89 #include "runtime/javaThread.inline.hpp"
90 #include "runtime/mutexLocker.hpp"
91 #include "runtime/orderAccess.hpp"
92 #include "runtime/os.inline.hpp"
93 #include "runtime/reflection.hpp"
94 #include "runtime/synchronizer.hpp"
95 #include "runtime/threads.hpp"
96 #include "services/classLoadingService.hpp"
97 #include "services/finalizerService.hpp"
98 #include "services/threadService.hpp"
99 #include "utilities/dtrace.hpp"
100 #include "utilities/events.hpp"
101 #include "utilities/macros.hpp"
102 #include "utilities/nativeStackPrinter.hpp"
103 #include "utilities/stringUtils.hpp"
104 #ifdef COMPILER1
105 #include "c1/c1_Compiler.hpp"
106 #endif
107 #if INCLUDE_JFR
108 #include "jfr/jfrEvents.hpp"
109 #endif
110
111 #ifdef DTRACE_ENABLED
112
113
114 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
115 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
116 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
117 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
118 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
119 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
120 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
121 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
122 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
123 { \
124 char* data = nullptr; \
125 int len = 0; \
126 Symbol* clss_name = name(); \
127 if (clss_name != nullptr) { \
128 data = (char*)clss_name->bytes(); \
129 len = clss_name->utf8_length(); \
130 } \
131 HOTSPOT_CLASS_INITIALIZATION_##type( \
132 data, len, (void*)class_loader(), thread_type); \
133 }
134
135 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
136 { \
137 char* data = nullptr; \
138 int len = 0; \
139 Symbol* clss_name = name(); \
140 if (clss_name != nullptr) { \
141 data = (char*)clss_name->bytes(); \
142 len = clss_name->utf8_length(); \
143 } \
144 HOTSPOT_CLASS_INITIALIZATION_##type( \
145 data, len, (void*)class_loader(), thread_type, wait); \
146 }
147
148 #else // ndef DTRACE_ENABLED
149
150 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
151 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
152
153 #endif // ndef DTRACE_ENABLED
154
155 void InlineLayoutInfo::metaspace_pointers_do(MetaspaceClosure* it) {
156 log_trace(cds)("Iter(InlineFieldInfo): %p", this);
157 it->push(&_klass);
158 }
159
160 bool InstanceKlass::_finalization_enabled = true;
161
162 static inline bool is_class_loader(const Symbol* class_name,
163 const ClassFileParser& parser) {
164 assert(class_name != nullptr, "invariant");
165
166 if (class_name == vmSymbols::java_lang_ClassLoader()) {
167 return true;
168 }
169
170 if (vmClasses::ClassLoader_klass_loaded()) {
171 const Klass* const super_klass = parser.super_klass();
172 if (super_klass != nullptr) {
173 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
174 return true;
175 }
176 }
177 }
178 return false;
179 }
180
181 bool InstanceKlass::field_is_null_free_inline_type(int index) const {
182 return field(index).field_flags().is_null_free_inline_type();
183 }
184
185 bool InstanceKlass::is_class_in_loadable_descriptors_attribute(Symbol* name) const {
186 if (_loadable_descriptors == nullptr) return false;
187 for (int i = 0; i < _loadable_descriptors->length(); i++) {
188 Symbol* class_name = _constants->symbol_at(_loadable_descriptors->at(i));
189 if (class_name == name) return true;
190 }
191 return false;
192 }
193
194 static inline bool is_stack_chunk_class(const Symbol* class_name,
195 const ClassLoaderData* loader_data) {
196 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
197 loader_data->is_the_null_class_loader_data());
198 }
199
200 // private: called to verify that k is a static member of this nest.
201 // We know that k is an instance class in the same package and hence the
202 // same classloader.
203 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
204 assert(!is_hidden(), "unexpected hidden class");
205 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
206 if (log_is_enabled(Trace, class, nestmates)) {
207 ResourceMark rm(current);
208 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
209 k->external_name(), this->external_name());
210 }
211 return false;
212 }
213
214 if (log_is_enabled(Trace, class, nestmates)) {
215 ResourceMark rm(current);
216 log_trace(class, nestmates)("Checking nest membership of %s in %s",
217 k->external_name(), this->external_name());
218 }
219
220 // Check for the named class in _nest_members.
221 // We don't resolve, or load, any classes.
222 for (int i = 0; i < _nest_members->length(); i++) {
223 int cp_index = _nest_members->at(i);
224 Symbol* name = _constants->klass_name_at(cp_index);
225 if (name == k->name()) {
226 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
227 return true;
228 }
229 }
230 log_trace(class, nestmates)("- class is NOT a nest member!");
231 return false;
232 }
233
234 // Called to verify that k is a permitted subclass of this class.
235 // The incoming stringStream is used to format the messages for error logging and for the caller
236 // to use for exception throwing.
237 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
238 Thread* current = Thread::current();
239 assert(k != nullptr, "sanity check");
240 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
241 "unexpected empty _permitted_subclasses array");
242
243 if (log_is_enabled(Trace, class, sealed)) {
244 ResourceMark rm(current);
245 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
246 k->external_name(), this->external_name());
247 }
248
249 // Check that the class and its super are in the same module.
250 if (k->module() != this->module()) {
251 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
252 "and sealed class %s is in module '%s' with loader %s",
253 k->external_name(),
254 k->module()->name_as_C_string(),
255 k->module()->loader_data()->loader_name_and_id(),
256 this->external_name(),
257 this->module()->name_as_C_string(),
258 this->module()->loader_data()->loader_name_and_id());
259 log_trace(class, sealed)(" - %s", ss.as_string());
260 return false;
261 }
262
263 if (!k->is_public() && !is_same_class_package(k)) {
264 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
265 "and sealed class %s is in package '%s' with classloader %s",
266 k->external_name(),
267 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
268 k->module()->loader_data()->loader_name_and_id(),
269 this->external_name(),
270 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
271 this->module()->loader_data()->loader_name_and_id());
272 log_trace(class, sealed)(" - %s", ss.as_string());
273 return false;
274 }
275
276 for (int i = 0; i < _permitted_subclasses->length(); i++) {
277 int cp_index = _permitted_subclasses->at(i);
278 Symbol* name = _constants->klass_name_at(cp_index);
279 if (name == k->name()) {
280 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
281 return true;
282 }
283 }
284
285 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
286 k->external_name(), this->external_name());
287 log_trace(class, sealed)(" - %s", ss.as_string());
288 return false;
289 }
290
291 // Return nest-host class, resolving, validating and saving it if needed.
292 // In cases where this is called from a thread that cannot do classloading
293 // (such as a native JIT thread) then we simply return null, which in turn
294 // causes the access check to return false. Such code will retry the access
295 // from a more suitable environment later. Otherwise the _nest_host is always
296 // set once this method returns.
297 // Any errors from nest-host resolution must be preserved so they can be queried
298 // from higher-level access checking code, and reported as part of access checking
299 // exceptions.
300 // VirtualMachineErrors are propagated with a null return.
301 // Under any conditions where the _nest_host can be set to non-null the resulting
302 // value of it and, if applicable, the nest host resolution/validation error,
303 // are idempotent.
304 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
305 InstanceKlass* nest_host_k = _nest_host;
306 if (nest_host_k != nullptr) {
307 return nest_host_k;
308 }
309
310 ResourceMark rm(THREAD);
311
312 // need to resolve and save our nest-host class.
313 if (_nest_host_index != 0) { // we have a real nest_host
314 // Before trying to resolve check if we're in a suitable context
315 bool can_resolve = THREAD->can_call_java();
316 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
317 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
318 this->external_name());
319 return nullptr; // sentinel to say "try again from a different context"
320 }
321
322 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
323 this->external_name(),
324 _constants->klass_name_at(_nest_host_index)->as_C_string());
325
326 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
327 if (HAS_PENDING_EXCEPTION) {
328 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
329 return nullptr; // propagate VMEs
330 }
331 stringStream ss;
332 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
333 ss.print("Nest host resolution of %s with host %s failed: ",
334 this->external_name(), target_host_class);
335 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
336 const char* msg = ss.as_string(true /* on C-heap */);
337 constantPoolHandle cph(THREAD, constants());
338 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
339 CLEAR_PENDING_EXCEPTION;
340
341 log_trace(class, nestmates)("%s", msg);
342 } else {
343 // A valid nest-host is an instance class in the current package that lists this
344 // class as a nest member. If any of these conditions are not met the class is
345 // its own nest-host.
346 const char* error = nullptr;
347
348 // JVMS 5.4.4 indicates package check comes first
349 if (is_same_class_package(k)) {
350 // Now check actual membership. We can't be a member if our "host" is
351 // not an instance class.
352 if (k->is_instance_klass()) {
353 nest_host_k = InstanceKlass::cast(k);
354 bool is_member = nest_host_k->has_nest_member(THREAD, this);
355 if (is_member) {
356 _nest_host = nest_host_k; // save resolved nest-host value
357
358 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
359 this->external_name(), k->external_name());
360 return nest_host_k;
361 } else {
362 error = "current type is not listed as a nest member";
363 }
364 } else {
365 error = "host is not an instance class";
366 }
367 } else {
368 error = "types are in different packages";
369 }
370
371 // something went wrong, so record what and log it
372 {
373 stringStream ss;
374 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
375 this->external_name(),
376 this->class_loader_data()->loader_name_and_id(),
377 k->external_name(),
378 k->class_loader_data()->loader_name_and_id(),
379 error);
380 const char* msg = ss.as_string(true /* on C-heap */);
381 constantPoolHandle cph(THREAD, constants());
382 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
383 log_trace(class, nestmates)("%s", msg);
384 }
385 }
386 } else {
387 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
388 this->external_name());
389 }
390
391 // Either not in an explicit nest, or else an error occurred, so
392 // the nest-host is set to `this`. Any thread that sees this assignment
393 // will also see any setting of nest_host_error(), if applicable.
394 return (_nest_host = this);
395 }
396
397 // Dynamic nest member support: set this class's nest host to the given class.
398 // This occurs as part of the class definition, as soon as the instanceKlass
399 // has been created and doesn't require further resolution. The code:
400 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
401 // results in:
402 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
403 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
404 // We also know the "host" is a valid nest-host in the same package so we can
405 // assert some of those facts.
406 void InstanceKlass::set_nest_host(InstanceKlass* host) {
407 assert(is_hidden(), "must be a hidden class");
408 assert(host != nullptr, "null nest host specified");
409 assert(_nest_host == nullptr, "current class has resolved nest-host");
410 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
411 nest_host_error());
412 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
413 (host->_nest_host == host), "proposed host is not a valid nest-host");
414 // Can't assert this as package is not set yet:
415 // assert(is_same_class_package(host), "proposed host is in wrong package");
416
417 if (log_is_enabled(Trace, class, nestmates)) {
418 ResourceMark rm;
419 const char* msg = "";
420 // a hidden class does not expect a statically defined nest-host
421 if (_nest_host_index > 0) {
422 msg = "(the NestHost attribute in the current class is ignored)";
423 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
424 msg = "(the NestMembers attribute in the current class is ignored)";
425 }
426 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
427 this->external_name(),
428 host->external_name(),
429 msg);
430 }
431 // set dynamic nest host
432 _nest_host = host;
433 // Record dependency to keep nest host from being unloaded before this class.
434 ClassLoaderData* this_key = class_loader_data();
435 assert(this_key != nullptr, "sanity");
436 this_key->record_dependency(host);
437 }
438
439 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
440 // or we are k's nest_host - all of which is covered by comparing the two
441 // resolved_nest_hosts.
442 // Any exceptions (i.e. VMEs) are propagated.
443 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
444
445 assert(this != k, "this should be handled by higher-level code");
446
447 // Per JVMS 5.4.4 we first resolve and validate the current class, then
448 // the target class k.
449
450 InstanceKlass* cur_host = nest_host(CHECK_false);
451 if (cur_host == nullptr) {
452 return false;
453 }
454
455 Klass* k_nest_host = k->nest_host(CHECK_false);
456 if (k_nest_host == nullptr) {
457 return false;
458 }
459
460 bool access = (cur_host == k_nest_host);
461
462 ResourceMark rm(THREAD);
463 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
464 this->external_name(),
465 access ? "" : "NOT ",
466 k->external_name());
467 return access;
468 }
469
470 const char* InstanceKlass::nest_host_error() {
471 if (_nest_host_index == 0) {
472 return nullptr;
473 } else {
474 constantPoolHandle cph(Thread::current(), constants());
475 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
476 }
477 }
478
479 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
480 bool use_class_space, TRAPS) throw() {
481 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
482 }
483
484 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
485 const int size = InstanceKlass::size(parser.vtable_size(),
486 parser.itable_size(),
487 nonstatic_oop_map_size(parser.total_oop_map_count()),
488 parser.is_interface(),
489 parser.is_inline_type());
490
491 const Symbol* const class_name = parser.class_name();
492 assert(class_name != nullptr, "invariant");
493 ClassLoaderData* loader_data = parser.loader_data();
494 assert(loader_data != nullptr, "invariant");
495
496 InstanceKlass* ik;
497 const bool use_class_space = parser.klass_needs_narrow_id();
498
499 // Allocation
500 if (parser.is_instance_ref_klass()) {
501 // java.lang.ref.Reference
502 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
503 } else if (class_name == vmSymbols::java_lang_Class()) {
504 // mirror - java.lang.Class
505 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
506 } else if (is_stack_chunk_class(class_name, loader_data)) {
507 // stack chunk
508 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
509 } else if (is_class_loader(class_name, parser)) {
510 // class loader - java.lang.ClassLoader
511 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
512 } else if (parser.is_inline_type()) {
513 // inline type
514 ik = new (loader_data, size, use_class_space, THREAD) InlineKlass(parser);
515 } else {
516 // normal
517 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
518 }
519
520 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
521 assert(CompressedKlassPointers::is_encodable(ik),
522 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
523 }
524
525 // Check for pending exception before adding to the loader data and incrementing
526 // class count. Can get OOM here.
527 if (HAS_PENDING_EXCEPTION) {
528 return nullptr;
529 }
530
531 #ifdef ASSERT
532 ik->bounds_check((address) ik->start_of_vtable(), false, size);
533 ik->bounds_check((address) ik->start_of_itable(), false, size);
534 ik->bounds_check((address) ik->end_of_itable(), true, size);
535 ik->bounds_check((address) ik->end_of_nonstatic_oop_maps(), true, size);
536 #endif //ASSERT
537 return ik;
538 }
539
540 #ifndef PRODUCT
541 bool InstanceKlass::bounds_check(address addr, bool edge_ok, intptr_t size_in_bytes) const {
542 const char* bad = nullptr;
543 address end = nullptr;
544 if (addr < (address)this) {
545 bad = "before";
546 } else if (addr == (address)this) {
547 if (edge_ok) return true;
548 bad = "just before";
549 } else if (addr == (end = (address)this + sizeof(intptr_t) * (size_in_bytes < 0 ? size() : size_in_bytes))) {
550 if (edge_ok) return true;
551 bad = "just after";
552 } else if (addr > end) {
553 bad = "after";
554 } else {
555 return true;
556 }
557 tty->print_cr("%s object bounds: " INTPTR_FORMAT " [" INTPTR_FORMAT ".." INTPTR_FORMAT "]",
558 bad, (intptr_t)addr, (intptr_t)this, (intptr_t)end);
559 Verbose = WizardMode = true; this->print(); //@@
560 return false;
561 }
562 #endif //PRODUCT
563
564 // copy method ordering from resource area to Metaspace
565 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
566 if (m != nullptr) {
567 // allocate a new array and copy contents (memcpy?)
568 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
569 for (int i = 0; i < m->length(); i++) {
570 _method_ordering->at_put(i, m->at(i));
571 }
572 } else {
573 _method_ordering = Universe::the_empty_int_array();
574 }
575 }
576
577 // create a new array of vtable_indices for default methods
578 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
579 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
580 assert(default_vtable_indices() == nullptr, "only create once");
581 set_default_vtable_indices(vtable_indices);
582 return vtable_indices;
583 }
584
585
586 InstanceKlass::InstanceKlass() {
587 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
588 }
589
590 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, markWord prototype_header, ReferenceType reference_type) :
591 Klass(kind, prototype_header),
592 _nest_members(nullptr),
593 _nest_host(nullptr),
594 _permitted_subclasses(nullptr),
595 _record_components(nullptr),
596 _static_field_size(parser.static_field_size()),
597 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
598 _itable_len(parser.itable_size()),
599 _nest_host_index(0),
600 _init_state(allocated),
601 _reference_type(reference_type),
602 _init_thread(nullptr),
603 _inline_layout_info_array(nullptr),
604 _loadable_descriptors(nullptr),
605 _adr_inlineklass_fixed_block(nullptr)
606 {
607 set_vtable_length(parser.vtable_size());
608 set_access_flags(parser.access_flags());
609 if (parser.is_hidden()) set_is_hidden();
610 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
611 false));
612 if (parser.has_inline_fields()) {
613 set_has_inline_type_fields();
614 }
615
616 assert(nullptr == _methods, "underlying memory not zeroed?");
617 assert(is_instance_klass(), "is layout incorrect?");
618 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
619 }
620
621 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
622 Array<Method*>* methods) {
623 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
624 !methods->is_shared()) {
625 for (int i = 0; i < methods->length(); i++) {
626 Method* method = methods->at(i);
627 if (method == nullptr) continue; // maybe null if error processing
628 // Only want to delete methods that are not executing for RedefineClasses.
629 // The previous version will point to them so they're not totally dangling
630 assert (!method->on_stack(), "shouldn't be called with methods on stack");
631 MetadataFactory::free_metadata(loader_data, method);
632 }
633 MetadataFactory::free_array<Method*>(loader_data, methods);
634 }
635 }
636
637 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
638 const Klass* super_klass,
639 Array<InstanceKlass*>* local_interfaces,
640 Array<InstanceKlass*>* transitive_interfaces) {
641 // Only deallocate transitive interfaces if not empty, same as super class
642 // or same as local interfaces. See code in parseClassFile.
643 Array<InstanceKlass*>* ti = transitive_interfaces;
644 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
645 // check that the interfaces don't come from super class
646 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
647 InstanceKlass::cast(super_klass)->transitive_interfaces();
648 if (ti != sti && ti != nullptr && !ti->is_shared()) {
649 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
650 }
651 }
652
653 // local interfaces can be empty
654 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
655 local_interfaces != nullptr && !local_interfaces->is_shared()) {
656 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
657 }
658 }
659
660 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
661 Array<RecordComponent*>* record_components) {
662 if (record_components != nullptr && !record_components->is_shared()) {
663 for (int i = 0; i < record_components->length(); i++) {
664 RecordComponent* record_component = record_components->at(i);
665 MetadataFactory::free_metadata(loader_data, record_component);
666 }
667 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
668 }
669 }
670
671 // This function deallocates the metadata and C heap pointers that the
672 // InstanceKlass points to.
673 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
674 // Orphan the mirror first, CMS thinks it's still live.
675 if (java_mirror() != nullptr) {
676 java_lang_Class::set_klass(java_mirror(), nullptr);
677 }
678
679 // Also remove mirror from handles
680 loader_data->remove_handle(_java_mirror);
681
682 // Need to take this class off the class loader data list.
683 loader_data->remove_class(this);
684
685 // The array_klass for this class is created later, after error handling.
686 // For class redefinition, we keep the original class so this scratch class
687 // doesn't have an array class. Either way, assert that there is nothing
688 // to deallocate.
689 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
690
691 // Release C heap allocated data that this points to, which includes
692 // reference counting symbol names.
693 // Can't release the constant pool or MethodData C heap data here because the constant
694 // pool can be deallocated separately from the InstanceKlass for default methods and
695 // redefine classes. MethodData can also be released separately.
696 release_C_heap_structures(/* release_sub_metadata */ false);
697
698 deallocate_methods(loader_data, methods());
699 set_methods(nullptr);
700
701 deallocate_record_components(loader_data, record_components());
702 set_record_components(nullptr);
703
704 if (method_ordering() != nullptr &&
705 method_ordering() != Universe::the_empty_int_array() &&
706 !method_ordering()->is_shared()) {
707 MetadataFactory::free_array<int>(loader_data, method_ordering());
708 }
709 set_method_ordering(nullptr);
710
711 // default methods can be empty
712 if (default_methods() != nullptr &&
713 default_methods() != Universe::the_empty_method_array() &&
714 !default_methods()->is_shared()) {
715 MetadataFactory::free_array<Method*>(loader_data, default_methods());
716 }
717 // Do NOT deallocate the default methods, they are owned by superinterfaces.
718 set_default_methods(nullptr);
719
720 // default methods vtable indices can be empty
721 if (default_vtable_indices() != nullptr &&
722 !default_vtable_indices()->is_shared()) {
723 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
724 }
725 set_default_vtable_indices(nullptr);
726
727
728 // This array is in Klass, but remove it with the InstanceKlass since
729 // this place would be the only caller and it can share memory with transitive
730 // interfaces.
731 if (secondary_supers() != nullptr &&
732 secondary_supers() != Universe::the_empty_klass_array() &&
733 // see comments in compute_secondary_supers about the following cast
734 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
735 !secondary_supers()->is_shared()) {
736 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
737 }
738 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
739
740 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
741 set_transitive_interfaces(nullptr);
742 set_local_interfaces(nullptr);
743
744 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
745 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
746 }
747 set_fieldinfo_stream(nullptr);
748
749 if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->is_shared()) {
750 MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
751 }
752 set_fieldinfo_search_table(nullptr);
753
754 if (fields_status() != nullptr && !fields_status()->is_shared()) {
755 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
756 }
757 set_fields_status(nullptr);
758
759 if (inline_layout_info_array() != nullptr) {
760 MetadataFactory::free_array<InlineLayoutInfo>(loader_data, inline_layout_info_array());
761 }
762 set_inline_layout_info_array(nullptr);
763
764 // If a method from a redefined class is using this constant pool, don't
765 // delete it, yet. The new class's previous version will point to this.
766 if (constants() != nullptr) {
767 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
768 if (!constants()->is_shared()) {
769 MetadataFactory::free_metadata(loader_data, constants());
770 }
771 // Delete any cached resolution errors for the constant pool
772 SystemDictionary::delete_resolution_error(constants());
773
774 set_constants(nullptr);
775 }
776
777 if (inner_classes() != nullptr &&
778 inner_classes() != Universe::the_empty_short_array() &&
779 !inner_classes()->is_shared()) {
780 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
781 }
782 set_inner_classes(nullptr);
783
784 if (nest_members() != nullptr &&
785 nest_members() != Universe::the_empty_short_array() &&
786 !nest_members()->is_shared()) {
787 MetadataFactory::free_array<jushort>(loader_data, nest_members());
788 }
789 set_nest_members(nullptr);
790
791 if (permitted_subclasses() != nullptr &&
792 permitted_subclasses() != Universe::the_empty_short_array() &&
793 !permitted_subclasses()->is_shared()) {
794 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
795 }
796 set_permitted_subclasses(nullptr);
797
798 if (loadable_descriptors() != nullptr &&
799 loadable_descriptors() != Universe::the_empty_short_array() &&
800 !loadable_descriptors()->is_shared()) {
801 MetadataFactory::free_array<jushort>(loader_data, loadable_descriptors());
802 }
803 set_loadable_descriptors(nullptr);
804
805 // We should deallocate the Annotations instance if it's not in shared spaces.
806 if (annotations() != nullptr && !annotations()->is_shared()) {
807 MetadataFactory::free_metadata(loader_data, annotations());
808 }
809 set_annotations(nullptr);
810
811 SystemDictionaryShared::handle_class_unloading(this);
812
813 #if INCLUDE_CDS_JAVA_HEAP
814 if (CDSConfig::is_dumping_heap()) {
815 HeapShared::remove_scratch_objects(this);
816 }
817 #endif
818 }
819
820 bool InstanceKlass::is_record() const {
821 return _record_components != nullptr &&
822 is_final() &&
823 java_super() == vmClasses::Record_klass();
824 }
825
826 bool InstanceKlass::is_sealed() const {
827 return _permitted_subclasses != nullptr &&
828 _permitted_subclasses != Universe::the_empty_short_array();
829 }
830
831 // JLS 8.9: An enum class is either implicitly final and derives
832 // from java.lang.Enum, or else is implicitly sealed to its
833 // anonymous subclasses. This query detects both kinds.
834 // It does not validate the finality or
835 // sealing conditions: it merely checks for a super of Enum.
836 // This is sufficient for recognizing well-formed enums.
837 bool InstanceKlass::is_enum_subclass() const {
838 InstanceKlass* s = java_super();
839 return (s == vmClasses::Enum_klass() ||
840 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
841 }
842
843 bool InstanceKlass::should_be_initialized() const {
844 return !is_initialized();
845 }
846
847 klassItable InstanceKlass::itable() const {
848 return klassItable(const_cast<InstanceKlass*>(this));
849 }
850
851 // JVMTI spec thinks there are signers and protection domain in the
852 // instanceKlass. These accessors pretend these fields are there.
853 // The hprof specification also thinks these fields are in InstanceKlass.
854 oop InstanceKlass::protection_domain() const {
855 // return the protection_domain from the mirror
856 return java_lang_Class::protection_domain(java_mirror());
857 }
858
859 objArrayOop InstanceKlass::signers() const {
860 // return the signers from the mirror
861 return java_lang_Class::signers(java_mirror());
862 }
863
864 oop InstanceKlass::init_lock() const {
865 // return the init lock from the mirror
866 oop lock = java_lang_Class::init_lock(java_mirror());
867 // Prevent reordering with any access of initialization state
868 OrderAccess::loadload();
869 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
870 "only fully initialized state can have a null lock");
871 return lock;
872 }
873
874 // Set the initialization lock to null so the object can be GC'ed. Any racing
875 // threads to get this lock will see a null lock and will not lock.
876 // That's okay because they all check for initialized state after getting
877 // the lock and return.
878 void InstanceKlass::fence_and_clear_init_lock() {
879 // make sure previous stores are all done, notably the init_state.
880 OrderAccess::storestore();
881 java_lang_Class::clear_init_lock(java_mirror());
882 assert(!is_not_initialized(), "class must be initialized now");
883 }
884
885
886 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
887 // process. The step comments refers to the procedure described in that section.
888 // Note: implementation moved to static method to expose the this pointer.
889 void InstanceKlass::initialize(TRAPS) {
890 if (this->should_be_initialized()) {
891 initialize_impl(CHECK);
892 // Note: at this point the class may be initialized
893 // OR it may be in the state of being initialized
894 // in case of recursive initialization!
895 } else {
896 assert(is_initialized(), "sanity check");
897 }
898 }
899
900 #ifdef ASSERT
901 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
902 assert(has_aot_initialized_mirror(), "must be");
903
904 InstanceKlass* s = java_super();
905 if (s != nullptr) {
906 DEBUG_ONLY(ResourceMark rm);
907 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
908 s->external_name(), external_name());
909 s->assert_no_clinit_will_run_for_aot_initialized_class();
910 }
911
912 Array<InstanceKlass*>* interfaces = local_interfaces();
913 int len = interfaces->length();
914 for (int i = 0; i < len; i++) {
915 InstanceKlass* intf = interfaces->at(i);
916 if (!intf->is_initialized()) {
917 ResourceMark rm;
918 // Note: an interface needs to be marked as is_initialized() only if
919 // - it has a <clinit>
920 // - it has declared a default method.
921 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
922 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
923 intf->external_name(), external_name());
924 }
925 }
926 }
927 #endif
928
929 #if INCLUDE_CDS
930 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
931 assert(has_aot_initialized_mirror(), "must be");
932 assert(CDSConfig::is_loading_heap(), "must be");
933 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
934 assert_no_clinit_will_run_for_aot_initialized_class();
935
936 if (is_initialized()) {
937 return;
938 }
939
940 if (is_runtime_setup_required()) {
941 // Need to take the slow path, which will call the runtimeSetup() function instead
942 // of <clinit>
943 initialize(CHECK);
944 return;
945 }
946 if (log_is_enabled(Info, aot, init)) {
947 ResourceMark rm;
948 log_info(aot, init)("%s (aot-inited)", external_name());
949 }
950
951 link_class(CHECK);
952
953 #ifdef ASSERT
954 {
955 Handle h_init_lock(THREAD, init_lock());
956 ObjectLocker ol(h_init_lock, THREAD);
957 assert(!is_initialized(), "sanity");
958 assert(!is_being_initialized(), "sanity");
959 assert(!is_in_error_state(), "sanity");
960 }
961 #endif
962
963 set_init_thread(THREAD);
964 set_initialization_state_and_notify(fully_initialized, CHECK);
965 }
966 #endif
967
968 bool InstanceKlass::verify_code(TRAPS) {
969 // 1) Verify the bytecodes
970 return Verifier::verify(this, should_verify_class(), THREAD);
971 }
972
973 void InstanceKlass::link_class(TRAPS) {
974 assert(is_loaded(), "must be loaded");
975 if (!is_linked()) {
976 link_class_impl(CHECK);
977 }
978 }
979
980 // Called to verify that a class can link during initialization, without
981 // throwing a VerifyError.
982 bool InstanceKlass::link_class_or_fail(TRAPS) {
983 assert(is_loaded(), "must be loaded");
984 if (!is_linked()) {
985 link_class_impl(CHECK_false);
986 }
987 return is_linked();
988 }
989
990 bool InstanceKlass::link_class_impl(TRAPS) {
991 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
992 // This is for CDS static dump only -- we use the in_error_state to indicate that
993 // the class has failed verification. Throwing the NoClassDefFoundError here is just
994 // a convenient way to stop repeat attempts to verify the same (bad) class.
995 //
996 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
997 // if we are executing Java code. This is not a problem for CDS dumping phase since
998 // it doesn't execute any Java code.
999 ResourceMark rm(THREAD);
1000 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1001 Exceptions::fthrow(THREAD_AND_LOCATION,
1002 vmSymbols::java_lang_NoClassDefFoundError(),
1003 "Class %s, or one of its supertypes, failed class initialization",
1004 external_name());
1005 return false;
1006 }
1007 // return if already verified
1008 if (is_linked()) {
1009 return true;
1010 }
1011
1012 // Timing
1013 // timer handles recursion
1014 JavaThread* jt = THREAD;
1015
1016 // link super class before linking this class
1017 Klass* super_klass = super();
1018 if (super_klass != nullptr) {
1019 if (super_klass->is_interface()) { // check if super class is an interface
1020 ResourceMark rm(THREAD);
1021 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1022 Exceptions::fthrow(
1023 THREAD_AND_LOCATION,
1024 vmSymbols::java_lang_IncompatibleClassChangeError(),
1025 "class %s has interface %s as super class",
1026 external_name(),
1027 super_klass->external_name()
1028 );
1029 return false;
1030 }
1031
1032 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
1033 ik_super->link_class_impl(CHECK_false);
1034 }
1035
1036 // link all interfaces implemented by this class before linking this class
1037 Array<InstanceKlass*>* interfaces = local_interfaces();
1038 int num_interfaces = interfaces->length();
1039 for (int index = 0; index < num_interfaces; index++) {
1040 InstanceKlass* interk = interfaces->at(index);
1041 interk->link_class_impl(CHECK_false);
1042 }
1043
1044
1045 // If a class declares a method that uses an inline class as an argument
1046 // type or return inline type, this inline class must be loaded during the
1047 // linking of this class because size and properties of the inline class
1048 // must be known in order to be able to perform inline type optimizations.
1049 // The implementation below is an approximation of this rule, the code
1050 // iterates over all methods of the current class (including overridden
1051 // methods), not only the methods declared by this class. This
1052 // approximation makes the code simpler, and doesn't change the semantic
1053 // because classes declaring methods overridden by the current class are
1054 // linked (and have performed their own pre-loading) before the linking
1055 // of the current class.
1056
1057
1058 // Note:
1059 // Inline class types are loaded during
1060 // the loading phase (see ClassFileParser::post_process_parsed_stream()).
1061 // Inline class types used as element types for array creation
1062 // are not pre-loaded. Their loading is triggered by either anewarray
1063 // or multianewarray bytecodes.
1064
1065 // Could it be possible to do the following processing only if the
1066 // class uses inline types?
1067 if (EnableValhalla) {
1068 ResourceMark rm(THREAD);
1069 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1070 if (fs.is_null_free_inline_type() && fs.access_flags().is_static()) {
1071 assert(fs.access_flags().is_strict(), "null-free fields must be strict");
1072 Symbol* sig = fs.signature();
1073 TempNewSymbol s = Signature::strip_envelope(sig);
1074 if (s != name()) {
1075 log_info(class, preload)("Preloading of class %s during linking of class %s. Cause: a null-free static field is declared with this type", s->as_C_string(), name()->as_C_string());
1076 Klass* klass = SystemDictionary::resolve_or_fail(s,
1077 Handle(THREAD, class_loader()), true,
1078 CHECK_false);
1079 if (HAS_PENDING_EXCEPTION) {
1080 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) failed: %s",
1081 s->as_C_string(), name()->as_C_string(), PENDING_EXCEPTION->klass()->name()->as_C_string());
1082 return false; // Exception is still pending
1083 }
1084 log_info(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) succeeded",
1085 s->as_C_string(), name()->as_C_string());
1086 assert(klass != nullptr, "Sanity check");
1087 if (klass->is_abstract()) {
1088 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1089 err_msg("Class %s expects class %s to be concrete value class, but it is an abstract class",
1090 name()->as_C_string(),
1091 InstanceKlass::cast(klass)->external_name()), false);
1092 }
1093 if (!klass->is_inline_klass()) {
1094 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1095 err_msg("class %s expects class %s to be a value class but it is an identity class",
1096 name()->as_C_string(), klass->external_name()), false);
1097 }
1098 InlineKlass* vk = InlineKlass::cast(klass);
1099 // the inline_type_field_klasses_array might have been loaded with CDS, so update only if not already set and check consistency
1100 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1101 if (li->klass() == nullptr) {
1102 li->set_klass(InlineKlass::cast(vk));
1103 li->set_kind(LayoutKind::REFERENCE);
1104 }
1105 assert(get_inline_type_field_klass(fs.index()) == vk, "Must match");
1106 } else {
1107 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1108 if (li->klass() == nullptr) {
1109 li->set_klass(InlineKlass::cast(this));
1110 li->set_kind(LayoutKind::REFERENCE);
1111 }
1112 assert(get_inline_type_field_klass(fs.index()) == this, "Must match");
1113 }
1114 }
1115 }
1116
1117 // Aggressively preloading all classes from the LoadableDescriptors attribute
1118 if (loadable_descriptors() != nullptr && PreloadClasses) {
1119 HandleMark hm(THREAD);
1120 for (int i = 0; i < loadable_descriptors()->length(); i++) {
1121 Symbol* sig = constants()->symbol_at(loadable_descriptors()->at(i));
1122 if (!Signature::has_envelope(sig)) continue;
1123 TempNewSymbol class_name = Signature::strip_envelope(sig);
1124 if (class_name == name()) continue;
1125 log_info(class, preload)("Preloading of class %s during linking of class %s because of the class is listed in the LoadableDescriptors attribute", sig->as_C_string(), name()->as_C_string());
1126 oop loader = class_loader();
1127 Klass* klass = SystemDictionary::resolve_or_null(class_name,
1128 Handle(THREAD, loader), THREAD);
1129 if (HAS_PENDING_EXCEPTION) {
1130 CLEAR_PENDING_EXCEPTION;
1131 }
1132 if (klass != nullptr) {
1133 log_info(class, preload)("Preloading of class %s during linking of class %s (cause: LoadableDescriptors attribute) succeeded", class_name->as_C_string(), name()->as_C_string());
1134 if (!klass->is_inline_klass()) {
1135 // Non value class are allowed by the current spec, but it could be an indication of an issue so let's log a warning
1136 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: LoadableDescriptors attribute) but loaded class is not a value class", class_name->as_C_string(), name()->as_C_string());
1137 }
1138 } else {
1139 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: LoadableDescriptors attribute) failed", class_name->as_C_string(), name()->as_C_string());
1140 }
1141 }
1142 }
1143 }
1144
1145 // in case the class is linked in the process of linking its superclasses
1146 if (is_linked()) {
1147 return true;
1148 }
1149
1150 // trace only the link time for this klass that includes
1151 // the verification time
1152 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
1153 ClassLoader::perf_class_link_selftime(),
1154 ClassLoader::perf_classes_linked(),
1155 jt->get_thread_stat()->perf_recursion_counts_addr(),
1156 jt->get_thread_stat()->perf_timers_addr(),
1157 PerfClassTraceTime::CLASS_LINK);
1158
1159 // verification & rewriting
1160 {
1161 HandleMark hm(THREAD);
1162 Handle h_init_lock(THREAD, init_lock());
1163 ObjectLocker ol(h_init_lock, jt);
1164 // rewritten will have been set if loader constraint error found
1165 // on an earlier link attempt
1166 // don't verify or rewrite if already rewritten
1167 //
1168
1169 if (!is_linked()) {
1170 if (!is_rewritten()) {
1171 if (is_shared()) {
1172 assert(!verified_at_dump_time(), "must be");
1173 }
1174 {
1175 bool verify_ok = verify_code(THREAD);
1176 if (!verify_ok) {
1177 return false;
1178 }
1179 }
1180
1181 // Just in case a side-effect of verify linked this class already
1182 // (which can sometimes happen since the verifier loads classes
1183 // using custom class loaders, which are free to initialize things)
1184 if (is_linked()) {
1185 return true;
1186 }
1187
1188 // also sets rewritten
1189 rewrite_class(CHECK_false);
1190 } else if (is_shared()) {
1191 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1192 }
1193
1194 // relocate jsrs and link methods after they are all rewritten
1195 link_methods(CHECK_false);
1196
1197 // Initialize the vtable and interface table after
1198 // methods have been rewritten since rewrite may
1199 // fabricate new Method*s.
1200 // also does loader constraint checking
1201 //
1202 // initialize_vtable and initialize_itable need to be rerun
1203 // for a shared class if
1204 // 1) the class is loaded by custom class loader or
1205 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1206 // 3) the class was not verified during dump time
1207 bool need_init_table = true;
1208 if (is_shared() && verified_at_dump_time() &&
1209 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1210 need_init_table = false;
1211 }
1212 if (need_init_table) {
1213 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1214 itable().initialize_itable_and_check_constraints(CHECK_false);
1215 }
1216 #ifdef ASSERT
1217 vtable().verify(tty, true);
1218 // In case itable verification is ever added.
1219 // itable().verify(tty, true);
1220 #endif
1221 if (Universe::is_fully_initialized()) {
1222 DeoptimizationScope deopt_scope;
1223 {
1224 // Now mark all code that assumes the class is not linked.
1225 // Set state under the Compile_lock also.
1226 MutexLocker ml(THREAD, Compile_lock);
1227
1228 set_init_state(linked);
1229 CodeCache::mark_dependents_on(&deopt_scope, this);
1230 }
1231 // Perform the deopt handshake outside Compile_lock.
1232 deopt_scope.deoptimize_marked();
1233 } else {
1234 set_init_state(linked);
1235 }
1236 if (JvmtiExport::should_post_class_prepare()) {
1237 JvmtiExport::post_class_prepare(THREAD, this);
1238 }
1239 }
1240 }
1241 return true;
1242 }
1243
1244 // Rewrite the byte codes of all of the methods of a class.
1245 // The rewriter must be called exactly once. Rewriting must happen after
1246 // verification but before the first method of the class is executed.
1247 void InstanceKlass::rewrite_class(TRAPS) {
1248 assert(is_loaded(), "must be loaded");
1249 if (is_rewritten()) {
1250 assert(is_shared(), "rewriting an unshared class?");
1251 return;
1252 }
1253 Rewriter::rewrite(this, CHECK);
1254 set_rewritten();
1255 }
1256
1257 // Now relocate and link method entry points after class is rewritten.
1258 // This is outside is_rewritten flag. In case of an exception, it can be
1259 // executed more than once.
1260 void InstanceKlass::link_methods(TRAPS) {
1261 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1262
1263 int len = methods()->length();
1264 for (int i = len-1; i >= 0; i--) {
1265 methodHandle m(THREAD, methods()->at(i));
1266
1267 // Set up method entry points for compiler and interpreter .
1268 m->link_method(m, CHECK);
1269 }
1270 }
1271
1272 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1273 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1274 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1275 for (int i = 0; i < local_interfaces()->length(); ++i) {
1276 InstanceKlass* ik = local_interfaces()->at(i);
1277
1278 // Initialization is depth first search ie. we start with top of the inheritance tree
1279 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1280 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1281 if (ik->has_nonstatic_concrete_methods()) {
1282 ik->initialize_super_interfaces(CHECK);
1283 }
1284
1285 // Only initialize() interfaces that "declare" concrete methods.
1286 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1287 ik->initialize(CHECK);
1288 }
1289 }
1290 }
1291
1292 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1293 static InitializationErrorTable* _initialization_error_table;
1294
1295 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1296 // Create the same exception with a message indicating the thread name,
1297 // and the StackTraceElements.
1298 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1299 ResourceMark rm(current);
1300 if (init_error.is_null()) {
1301 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1302
1303 // We failed to create the new exception, most likely due to either out-of-memory or
1304 // a stackoverflow error. If the original exception was either of those then we save
1305 // the shared, pre-allocated, stackless, instance of that exception.
1306 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1307 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1308 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1309 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1310 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1311 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1312 } else {
1313 return;
1314 }
1315 }
1316
1317 MutexLocker ml(current, ClassInitError_lock);
1318 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1319 bool created;
1320 if (_initialization_error_table == nullptr) {
1321 _initialization_error_table = new (mtClass) InitializationErrorTable();
1322 }
1323 _initialization_error_table->put_if_absent(this, elem, &created);
1324 assert(created, "Initialization is single threaded");
1325 log_trace(class, init)("Initialization error added for class %s", external_name());
1326 }
1327
1328 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1329 MutexLocker ml(current, ClassInitError_lock);
1330 if (_initialization_error_table == nullptr) {
1331 return nullptr;
1332 }
1333 OopHandle* h = _initialization_error_table->get(this);
1334 return (h != nullptr) ? h->resolve() : nullptr;
1335 }
1336
1337 // Need to remove entries for unloaded classes.
1338 void InstanceKlass::clean_initialization_error_table() {
1339 struct InitErrorTableCleaner {
1340 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1341 if (!ik->is_loader_alive()) {
1342 h.release(Universe::vm_global());
1343 return true;
1344 } else {
1345 return false;
1346 }
1347 }
1348 };
1349
1350 assert_locked_or_safepoint(ClassInitError_lock);
1351 InitErrorTableCleaner cleaner;
1352 if (_initialization_error_table != nullptr) {
1353 _initialization_error_table->unlink(&cleaner);
1354 }
1355 }
1356
1357 void InstanceKlass::initialize_impl(TRAPS) {
1358 HandleMark hm(THREAD);
1359
1360 // Make sure klass is linked (verified) before initialization
1361 // A class could already be verified, since it has been reflected upon.
1362 link_class(CHECK);
1363
1364 DTRACE_CLASSINIT_PROBE(required, -1);
1365
1366 bool wait = false;
1367
1368 JavaThread* jt = THREAD;
1369
1370 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1371
1372 // refer to the JVM book page 47 for description of steps
1373 // Step 1
1374 {
1375 Handle h_init_lock(THREAD, init_lock());
1376 ObjectLocker ol(h_init_lock, jt);
1377
1378 // Step 2
1379 // If we were to use wait() instead of waitInterruptibly() then
1380 // we might end up throwing IE from link/symbol resolution sites
1381 // that aren't expected to throw. This would wreak havoc. See 6320309.
1382 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1383 if (debug_logging_enabled) {
1384 ResourceMark rm(jt);
1385 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1386 jt->name(), external_name(), init_thread_name());
1387 }
1388 wait = true;
1389 jt->set_class_to_be_initialized(this);
1390 ol.wait_uninterruptibly(jt);
1391 jt->set_class_to_be_initialized(nullptr);
1392 }
1393
1394 // Step 3
1395 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1396 if (debug_logging_enabled) {
1397 ResourceMark rm(jt);
1398 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1399 jt->name(), external_name());
1400 }
1401 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1402 return;
1403 }
1404
1405 // Step 4
1406 if (is_initialized()) {
1407 if (debug_logging_enabled) {
1408 ResourceMark rm(jt);
1409 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1410 jt->name(), external_name());
1411 }
1412 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1413 return;
1414 }
1415
1416 // Step 5
1417 if (is_in_error_state()) {
1418 if (debug_logging_enabled) {
1419 ResourceMark rm(jt);
1420 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1421 jt->name(), external_name());
1422 }
1423
1424 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1425 ResourceMark rm(THREAD);
1426 Handle cause(THREAD, get_initialization_error(THREAD));
1427
1428 stringStream ss;
1429 ss.print("Could not initialize class %s", external_name());
1430 if (cause.is_null()) {
1431 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1432 } else {
1433 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1434 ss.as_string(), cause);
1435 }
1436 } else {
1437
1438 // Step 6
1439 set_init_state(being_initialized);
1440 set_init_thread(jt);
1441 if (debug_logging_enabled) {
1442 ResourceMark rm(jt);
1443 log_debug(class, init)("Thread \"%s\" is initializing %s",
1444 jt->name(), external_name());
1445 }
1446 }
1447 }
1448
1449 // Pre-allocating an all-zero value to be used to reset nullable flat storages
1450 if (is_inline_klass()) {
1451 InlineKlass* vk = InlineKlass::cast(this);
1452 if (vk->has_nullable_atomic_layout()) {
1453 oop val = vk->allocate_instance(THREAD);
1454 if (HAS_PENDING_EXCEPTION) {
1455 Handle e(THREAD, PENDING_EXCEPTION);
1456 CLEAR_PENDING_EXCEPTION;
1457 {
1458 EXCEPTION_MARK;
1459 add_initialization_error(THREAD, e);
1460 // Locks object, set state, and notify all waiting threads
1461 set_initialization_state_and_notify(initialization_error, THREAD);
1462 CLEAR_PENDING_EXCEPTION;
1463 }
1464 THROW_OOP(e());
1465 }
1466 vk->set_null_reset_value(val);
1467 }
1468 }
1469
1470 // Step 7
1471 // Next, if C is a class rather than an interface, initialize it's super class and super
1472 // interfaces.
1473 if (!is_interface()) {
1474 Klass* super_klass = super();
1475 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1476 super_klass->initialize(THREAD);
1477 }
1478 // If C implements any interface that declares a non-static, concrete method,
1479 // the initialization of C triggers initialization of its super interfaces.
1480 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1481 // having a superinterface that declares, non-static, concrete methods
1482 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1483 initialize_super_interfaces(THREAD);
1484 }
1485
1486 // If any exceptions, complete abruptly, throwing the same exception as above.
1487 if (HAS_PENDING_EXCEPTION) {
1488 Handle e(THREAD, PENDING_EXCEPTION);
1489 CLEAR_PENDING_EXCEPTION;
1490 {
1491 EXCEPTION_MARK;
1492 add_initialization_error(THREAD, e);
1493 // Locks object, set state, and notify all waiting threads
1494 set_initialization_state_and_notify(initialization_error, THREAD);
1495 CLEAR_PENDING_EXCEPTION;
1496 }
1497 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1498 THROW_OOP(e());
1499 }
1500 }
1501
1502 // Step 8
1503 {
1504 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1505 if (class_initializer() != nullptr) {
1506 // Timer includes any side effects of class initialization (resolution,
1507 // etc), but not recursive entry into call_class_initializer().
1508 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1509 ClassLoader::perf_class_init_selftime(),
1510 ClassLoader::perf_classes_inited(),
1511 jt->get_thread_stat()->perf_recursion_counts_addr(),
1512 jt->get_thread_stat()->perf_timers_addr(),
1513 PerfClassTraceTime::CLASS_CLINIT);
1514 call_class_initializer(THREAD);
1515 } else {
1516 // The elapsed time is so small it's not worth counting.
1517 if (UsePerfData) {
1518 ClassLoader::perf_classes_inited()->inc();
1519 }
1520 call_class_initializer(THREAD);
1521 }
1522
1523 if (has_strict_static_fields() && !HAS_PENDING_EXCEPTION) {
1524 // Step 9 also verifies that strict static fields have been initialized.
1525 // Status bits were set in ClassFileParser::post_process_parsed_stream.
1526 // After <clinit>, bits must all be clear, or else we must throw an error.
1527 // This is an extremely fast check, so we won't bother with a timer.
1528 assert(fields_status() != nullptr, "");
1529 Symbol* bad_strict_static = nullptr;
1530 for (int index = 0; index < fields_status()->length(); index++) {
1531 // Very fast loop over single byte array looking for a set bit.
1532 if (fields_status()->adr_at(index)->is_strict_static_unset()) {
1533 // This strict static field has not been set by the class initializer.
1534 // Note that in the common no-error case, we read no field metadata.
1535 // We only unpack it when we need to report an error.
1536 FieldInfo fi = field(index);
1537 bad_strict_static = fi.name(constants());
1538 if (debug_logging_enabled) {
1539 ResourceMark rm(jt);
1540 const char* msg = format_strict_static_message(bad_strict_static);
1541 log_debug(class, init)("%s", msg);
1542 } else {
1543 // If we are not logging, do not bother to look for a second offense.
1544 break;
1545 }
1546 }
1547 }
1548 if (bad_strict_static != nullptr) {
1549 throw_strict_static_exception(bad_strict_static, "is unset after initialization of", THREAD);
1550 }
1551 }
1552 }
1553
1554 // Step 9
1555 if (!HAS_PENDING_EXCEPTION) {
1556 set_initialization_state_and_notify(fully_initialized, CHECK);
1557 DEBUG_ONLY(vtable().verify(tty, true);)
1558 CompilationPolicy::replay_training_at_init(this, THREAD);
1559 }
1560 else {
1561 // Step 10 and 11
1562 Handle e(THREAD, PENDING_EXCEPTION);
1563 CLEAR_PENDING_EXCEPTION;
1564 // JVMTI has already reported the pending exception
1565 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1566 JvmtiExport::clear_detected_exception(jt);
1567 {
1568 EXCEPTION_MARK;
1569 add_initialization_error(THREAD, e);
1570 set_initialization_state_and_notify(initialization_error, THREAD);
1571 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1572 // JVMTI has already reported the pending exception
1573 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1574 JvmtiExport::clear_detected_exception(jt);
1575 }
1576 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1577 if (e->is_a(vmClasses::Error_klass())) {
1578 THROW_OOP(e());
1579 } else {
1580 JavaCallArguments args(e);
1581 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1582 vmSymbols::throwable_void_signature(),
1583 &args);
1584 }
1585 }
1586 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1587 }
1588
1589
1590 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1591 Handle h_init_lock(THREAD, init_lock());
1592 if (h_init_lock() != nullptr) {
1593 ObjectLocker ol(h_init_lock, THREAD);
1594 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1595 set_init_state(state);
1596 fence_and_clear_init_lock();
1597 ol.notify_all(CHECK);
1598 } else {
1599 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1600 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1601 set_init_state(state);
1602 }
1603 }
1604
1605 void InstanceKlass::notify_strict_static_access(int field_index, bool is_writing, TRAPS) {
1606 guarantee(field_index >= 0 && field_index < fields_status()->length(), "valid field index");
1607 DEBUG_ONLY(FieldInfo debugfi = field(field_index));
1608 assert(debugfi.access_flags().is_strict(), "");
1609 assert(debugfi.access_flags().is_static(), "");
1610 FieldStatus& fs = *fields_status()->adr_at(field_index);
1611 LogTarget(Trace, class, init) lt;
1612 if (lt.is_enabled()) {
1613 ResourceMark rm(THREAD);
1614 LogStream ls(lt);
1615 FieldInfo fi = field(field_index);
1616 ls.print("notify %s %s %s%s ",
1617 external_name(), is_writing? "Write" : "Read",
1618 fs.is_strict_static_unset() ? "Unset" : "(set)",
1619 fs.is_strict_static_unread() ? "+Unread" : "");
1620 fi.print(&ls, constants());
1621 }
1622 if (fs.is_strict_static_unset()) {
1623 assert(fs.is_strict_static_unread(), "ClassFileParser resp.");
1624 // If it is not set, there are only two reasonable things we can do here:
1625 // - mark it set if this is putstatic
1626 // - throw an error (Read-Before-Write) if this is getstatic
1627
1628 // The unset state is (or should be) transient, and observable only in one
1629 // thread during the execution of <clinit>. Something is wrong here as this
1630 // should not be possible
1631 guarantee(is_reentrant_initialization(THREAD), "unscoped access to strict static");
1632 if (is_writing) {
1633 // clear the "unset" bit, since the field is actually going to be written
1634 fs.update_strict_static_unset(false);
1635 } else {
1636 // throw an IllegalStateException, since we are reading before writing
1637 // see also InstanceKlass::initialize_impl, Step 8 (at end)
1638 Symbol* bad_strict_static = field(field_index).name(constants());
1639 throw_strict_static_exception(bad_strict_static, "is unset before first read in", CHECK);
1640 }
1641 } else {
1642 // Ensure no write after read for final strict statics
1643 FieldInfo fi = field(field_index);
1644 bool is_final = fi.access_flags().is_final();
1645 if (is_final) {
1646 // no final write after read, so observing a constant freezes it, as if <clinit> ended early
1647 // (maybe we could trust the constant a little earlier, before <clinit> ends)
1648 if (is_writing && !fs.is_strict_static_unread()) {
1649 Symbol* bad_strict_static = fi.name(constants());
1650 throw_strict_static_exception(bad_strict_static, "is set after read (as final) in", CHECK);
1651 } else if (!is_writing && fs.is_strict_static_unread()) {
1652 fs.update_strict_static_unread(false);
1653 }
1654 }
1655 }
1656 }
1657
1658 void InstanceKlass::throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS) {
1659 ResourceMark rm(THREAD);
1660 const char* msg = format_strict_static_message(field_name, when);
1661 THROW_MSG(vmSymbols::java_lang_IllegalStateException(), msg);
1662 }
1663
1664 const char* InstanceKlass::format_strict_static_message(Symbol* field_name, const char* when) {
1665 stringStream ss;
1666 ss.print("Strict static \"%s\" %s %s",
1667 field_name->as_C_string(),
1668 when == nullptr ? "is unset in" : when,
1669 external_name());
1670 return ss.as_string();
1671 }
1672
1673 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1674 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1675 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1676 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1677
1678 DeoptimizationScope deopt_scope;
1679 {
1680 MutexLocker ml(current, Compile_lock);
1681
1682 set_init_state(InstanceKlass::loaded);
1683 // make sure init_state store is already done.
1684 // The compiler reads the hierarchy outside of the Compile_lock.
1685 // Access ordering is used to add to hierarchy.
1686
1687 // Link into hierarchy.
1688 append_to_sibling_list(); // add to superklass/sibling list
1689 process_interfaces(); // handle all "implements" declarations
1690
1691 // Now mark all code that depended on old class hierarchy.
1692 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1693 if (Universe::is_fully_initialized()) {
1694 CodeCache::mark_dependents_on(&deopt_scope, this);
1695 }
1696 }
1697 // Perform the deopt handshake outside Compile_lock.
1698 deopt_scope.deoptimize_marked();
1699 }
1700
1701
1702 InstanceKlass* InstanceKlass::implementor() const {
1703 InstanceKlass* volatile* ik = adr_implementor();
1704 if (ik == nullptr) {
1705 return nullptr;
1706 } else {
1707 // This load races with inserts, and therefore needs acquire.
1708 InstanceKlass* ikls = Atomic::load_acquire(ik);
1709 if (ikls != nullptr && !ikls->is_loader_alive()) {
1710 return nullptr; // don't return unloaded class
1711 } else {
1712 return ikls;
1713 }
1714 }
1715 }
1716
1717
1718 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1719 assert_locked_or_safepoint(Compile_lock);
1720 assert(is_interface(), "not interface");
1721 InstanceKlass* volatile* addr = adr_implementor();
1722 assert(addr != nullptr, "null addr");
1723 if (addr != nullptr) {
1724 Atomic::release_store(addr, ik);
1725 }
1726 }
1727
1728 int InstanceKlass::nof_implementors() const {
1729 InstanceKlass* ik = implementor();
1730 if (ik == nullptr) {
1731 return 0;
1732 } else if (ik != this) {
1733 return 1;
1734 } else {
1735 return 2;
1736 }
1737 }
1738
1739 // The embedded _implementor field can only record one implementor.
1740 // When there are more than one implementors, the _implementor field
1741 // is set to the interface Klass* itself. Following are the possible
1742 // values for the _implementor field:
1743 // null - no implementor
1744 // implementor Klass* - one implementor
1745 // self - more than one implementor
1746 //
1747 // The _implementor field only exists for interfaces.
1748 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1749 if (Universe::is_fully_initialized()) {
1750 assert_lock_strong(Compile_lock);
1751 }
1752 assert(is_interface(), "not interface");
1753 // Filter out my subinterfaces.
1754 // (Note: Interfaces are never on the subklass list.)
1755 if (ik->is_interface()) return;
1756
1757 // Filter out subclasses whose supers already implement me.
1758 // (Note: CHA must walk subclasses of direct implementors
1759 // in order to locate indirect implementors.)
1760 InstanceKlass* super_ik = ik->java_super();
1761 if (super_ik != nullptr && super_ik->implements_interface(this))
1762 // We only need to check one immediate superclass, since the
1763 // implements_interface query looks at transitive_interfaces.
1764 // Any supers of the super have the same (or fewer) transitive_interfaces.
1765 return;
1766
1767 InstanceKlass* iklass = implementor();
1768 if (iklass == nullptr) {
1769 set_implementor(ik);
1770 } else if (iklass != this && iklass != ik) {
1771 // There is already an implementor. Use itself as an indicator of
1772 // more than one implementors.
1773 set_implementor(this);
1774 }
1775
1776 // The implementor also implements the transitive_interfaces
1777 for (int index = 0; index < local_interfaces()->length(); index++) {
1778 local_interfaces()->at(index)->add_implementor(ik);
1779 }
1780 }
1781
1782 void InstanceKlass::init_implementor() {
1783 if (is_interface()) {
1784 set_implementor(nullptr);
1785 }
1786 }
1787
1788
1789 void InstanceKlass::process_interfaces() {
1790 // link this class into the implementors list of every interface it implements
1791 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1792 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1793 InstanceKlass* interf = local_interfaces()->at(i);
1794 assert(interf->is_interface(), "expected interface");
1795 interf->add_implementor(this);
1796 }
1797 }
1798
1799 bool InstanceKlass::can_be_primary_super_slow() const {
1800 if (is_interface())
1801 return false;
1802 else
1803 return Klass::can_be_primary_super_slow();
1804 }
1805
1806 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1807 Array<InstanceKlass*>* transitive_interfaces) {
1808 // The secondaries are the implemented interfaces.
1809 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1810 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1811 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1812 int num_secondaries = num_extra_slots + interfaces->length();
1813 if (num_secondaries == 0) {
1814 // Must share this for correct bootstrapping!
1815 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1816 return nullptr;
1817 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1818 // We will reuse the transitive interfaces list if we're certain
1819 // it's in hash order.
1820 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1821 set_secondary_supers(interfaces, bitmap);
1822 return nullptr;
1823 }
1824 // Copy transitive interfaces to a temporary growable array to be constructed
1825 // into the secondary super list with extra slots.
1826 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1827 for (int i = 0; i < interfaces->length(); i++) {
1828 secondaries->push(interfaces->at(i));
1829 }
1830 return secondaries;
1831 }
1832
1833 bool InstanceKlass::implements_interface(Klass* k) const {
1834 if (this == k) return true;
1835 assert(k->is_interface(), "should be an interface class");
1836 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1837 if (transitive_interfaces()->at(i) == k) {
1838 return true;
1839 }
1840 }
1841 return false;
1842 }
1843
1844 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1845 // Verify direct super interface
1846 if (this == k) return true;
1847 assert(k->is_interface(), "should be an interface class");
1848 for (int i = 0; i < local_interfaces()->length(); i++) {
1849 if (local_interfaces()->at(i) == k) {
1850 return true;
1851 }
1852 }
1853 return false;
1854 }
1855
1856 objArrayOop InstanceKlass::allocate_objArray(int length, ArrayKlass::ArrayProperties props, TRAPS) {
1857 ArrayKlass* ak = array_klass(CHECK_NULL);
1858 return ObjArrayKlass::cast(ak)->allocate_instance(length, props, CHECK_NULL);
1859 }
1860
1861 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1862 if (TraceFinalizerRegistration) {
1863 tty->print("Registered ");
1864 i->print_value_on(tty);
1865 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1866 }
1867 instanceHandle h_i(THREAD, i);
1868 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1869 JavaValue result(T_VOID);
1870 JavaCallArguments args(h_i);
1871 methodHandle mh(THREAD, Universe::finalizer_register_method());
1872 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1873 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1874 return h_i();
1875 }
1876
1877 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1878 assert(!is_abstract() && !is_interface(), "Should not create this object");
1879 size_t size = size_helper(); // Query before forming handle.
1880 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1881 }
1882
1883 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1884 Klass* k = java_lang_Class::as_Klass(java_class);
1885 if (k == nullptr) {
1886 ResourceMark rm(THREAD);
1887 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1888 }
1889 InstanceKlass* ik = cast(k);
1890 ik->check_valid_for_instantiation(false, CHECK_NULL);
1891 ik->initialize(CHECK_NULL);
1892 return ik->allocate_instance(THREAD);
1893 }
1894
1895 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1896 return instanceHandle(THREAD, allocate_instance(THREAD));
1897 }
1898
1899 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1900 if (is_interface() || is_abstract()) {
1901 ResourceMark rm(THREAD);
1902 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1903 : vmSymbols::java_lang_InstantiationException(), external_name());
1904 }
1905 if (this == vmClasses::Class_klass()) {
1906 ResourceMark rm(THREAD);
1907 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1908 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1909 }
1910 }
1911
1912 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1913 // Need load-acquire for lock-free read
1914 if (array_klasses_acquire() == nullptr) {
1915
1916 // Recursively lock array allocation
1917 RecursiveLocker rl(MultiArray_lock, THREAD);
1918
1919 // Check if another thread created the array klass while we were waiting for the lock.
1920 if (array_klasses() == nullptr) {
1921 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1922 // use 'release' to pair with lock-free load
1923 release_set_array_klasses(k);
1924 }
1925 }
1926
1927 // array_klasses() will always be set at this point
1928 ArrayKlass* ak = array_klasses();
1929 assert(ak != nullptr, "should be set");
1930 return ak->array_klass(n, THREAD);
1931 }
1932
1933 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1934 // Need load-acquire for lock-free read
1935 ArrayKlass* ak = array_klasses_acquire();
1936 if (ak == nullptr) {
1937 return nullptr;
1938 } else {
1939 return ak->array_klass_or_null(n);
1940 }
1941 }
1942
1943 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1944 return array_klass(1, THREAD);
1945 }
1946
1947 ArrayKlass* InstanceKlass::array_klass_or_null() {
1948 return array_klass_or_null(1);
1949 }
1950
1951 static int call_class_initializer_counter = 0; // for debugging
1952
1953 Method* InstanceKlass::class_initializer() const {
1954 Method* clinit = find_method(
1955 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1956 if (clinit != nullptr && clinit->is_class_initializer()) {
1957 return clinit;
1958 }
1959 return nullptr;
1960 }
1961
1962 void InstanceKlass::call_class_initializer(TRAPS) {
1963 if (ReplayCompiles &&
1964 (ReplaySuppressInitializers == 1 ||
1965 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1966 // Hide the existence of the initializer for the purpose of replaying the compile
1967 return;
1968 }
1969
1970 #if INCLUDE_CDS
1971 // This is needed to ensure the consistency of the archived heap objects.
1972 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1973 AOTClassInitializer::call_runtime_setup(THREAD, this);
1974 return;
1975 } else if (has_archived_enum_objs()) {
1976 assert(is_shared(), "must be");
1977 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1978 if (initialized) {
1979 return;
1980 }
1981 }
1982 #endif
1983
1984 methodHandle h_method(THREAD, class_initializer());
1985 assert(!is_initialized(), "we cannot initialize twice");
1986 LogTarget(Info, class, init) lt;
1987 if (lt.is_enabled()) {
1988 ResourceMark rm(THREAD);
1989 LogStream ls(lt);
1990 ls.print("%d Initializing ", call_class_initializer_counter++);
1991 name()->print_value_on(&ls);
1992 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1993 h_method() == nullptr ? "(no method)" : "", p2i(this),
1994 THREAD->name());
1995 }
1996 if (h_method() != nullptr) {
1997 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1998 JavaCallArguments args; // No arguments
1999 JavaValue result(T_VOID);
2000 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
2001 }
2002 }
2003
2004 // If a class that implements this interface is initialized, is the JVM required
2005 // to first execute a <clinit> method declared in this interface,
2006 // or (if also_check_supers==true) any of the super types of this interface?
2007 //
2008 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
2009 // an interface, then let SC be its superclass and let SI1, ..., SIn
2010 // be all superinterfaces of C (whether direct or indirect) that
2011 // declare at least one non-abstract, non-static method.
2012 //
2013 // So when an interface is initialized, it does not look at its
2014 // supers. But a proper class will ensure that all of its supers have
2015 // run their <clinit> methods, except that it disregards interfaces
2016 // that lack a non-static concrete method (i.e., a default method).
2017 // Therefore, you should probably call this method only when the
2018 // current class is a super of some proper class, not an interface.
2019 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
2020 assert(is_interface(), "must be");
2021
2022 if (!has_nonstatic_concrete_methods()) {
2023 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
2024 return false;
2025 }
2026
2027 // JVMS 5.5. Initialization
2028 // ...If C is an interface that declares a non-abstract,
2029 // non-static method, the initialization of a class that
2030 // implements C directly or indirectly.
2031 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
2032 return true;
2033 }
2034 if (also_check_supers) {
2035 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2036 for (int i = 0; i < all_ifs->length(); ++i) {
2037 InstanceKlass* super_intf = all_ifs->at(i);
2038 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
2039 return true;
2040 }
2041 }
2042 }
2043 return false;
2044 }
2045
2046 void InstanceKlass::mask_for(const methodHandle& method, int bci,
2047 InterpreterOopMap* entry_for) {
2048 // Lazily create the _oop_map_cache at first request.
2049 // Load_acquire is needed to safely get instance published with CAS by another thread.
2050 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
2051 if (oop_map_cache == nullptr) {
2052 // Try to install new instance atomically.
2053 oop_map_cache = new OopMapCache();
2054 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
2055 if (other != nullptr) {
2056 // Someone else managed to install before us, ditch local copy and use the existing one.
2057 delete oop_map_cache;
2058 oop_map_cache = other;
2059 }
2060 }
2061 // _oop_map_cache is constant after init; lookup below does its own locking.
2062 oop_map_cache->lookup(method, bci, entry_for);
2063 }
2064
2065
2066 FieldInfo InstanceKlass::field(int index) const {
2067 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2068 if (fs.index() == index) {
2069 return fs.to_FieldInfo();
2070 }
2071 }
2072 fatal("Field not found");
2073 return FieldInfo();
2074 }
2075
2076 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2077 JavaFieldStream fs(this);
2078 if (fs.lookup(name, sig)) {
2079 assert(fs.name() == name, "name must match");
2080 assert(fs.signature() == sig, "signature must match");
2081 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2082 return true;
2083 }
2084 return false;
2085 }
2086
2087
2088 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2089 const int n = local_interfaces()->length();
2090 for (int i = 0; i < n; i++) {
2091 Klass* intf1 = local_interfaces()->at(i);
2092 assert(intf1->is_interface(), "just checking type");
2093 // search for field in current interface
2094 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
2095 assert(fd->is_static(), "interface field must be static");
2096 return intf1;
2097 }
2098 // search for field in direct superinterfaces
2099 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
2100 if (intf2 != nullptr) return intf2;
2101 }
2102 // otherwise field lookup fails
2103 return nullptr;
2104 }
2105
2106
2107 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2108 // search order according to newest JVM spec (5.4.3.2, p.167).
2109 // 1) search for field in current klass
2110 if (find_local_field(name, sig, fd)) {
2111 return const_cast<InstanceKlass*>(this);
2112 }
2113 // 2) search for field recursively in direct superinterfaces
2114 { Klass* intf = find_interface_field(name, sig, fd);
2115 if (intf != nullptr) return intf;
2116 }
2117 // 3) apply field lookup recursively if superclass exists
2118 { Klass* supr = super();
2119 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
2120 }
2121 // 4) otherwise field lookup fails
2122 return nullptr;
2123 }
2124
2125
2126 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
2127 // search order according to newest JVM spec (5.4.3.2, p.167).
2128 // 1) search for field in current klass
2129 if (find_local_field(name, sig, fd)) {
2130 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
2131 }
2132 // 2) search for field recursively in direct superinterfaces
2133 if (is_static) {
2134 Klass* intf = find_interface_field(name, sig, fd);
2135 if (intf != nullptr) return intf;
2136 }
2137 // 3) apply field lookup recursively if superclass exists
2138 { Klass* supr = super();
2139 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
2140 }
2141 // 4) otherwise field lookup fails
2142 return nullptr;
2143 }
2144
2145 bool InstanceKlass::contains_field_offset(int offset) {
2146 if (this->is_inline_klass()) {
2147 InlineKlass* vk = InlineKlass::cast(this);
2148 return offset >= vk->payload_offset() && offset < (vk->payload_offset() + vk->payload_size_in_bytes());
2149 } else {
2150 fieldDescriptor fd;
2151 return find_field_from_offset(offset, false, &fd);
2152 }
2153 }
2154
2155 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2156 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2157 if (fs.offset() == offset) {
2158 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2159 if (fd->is_static() == is_static) return true;
2160 }
2161 }
2162 return false;
2163 }
2164
2165
2166 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2167 Klass* klass = const_cast<InstanceKlass*>(this);
2168 while (klass != nullptr) {
2169 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
2170 return true;
2171 }
2172 klass = klass->super();
2173 }
2174 return false;
2175 }
2176
2177
2178 void InstanceKlass::methods_do(void f(Method* method)) {
2179 // Methods aren't stable until they are loaded. This can be read outside
2180 // a lock through the ClassLoaderData for profiling
2181 // Redefined scratch classes are on the list and need to be cleaned
2182 if (!is_loaded() && !is_scratch_class()) {
2183 return;
2184 }
2185
2186 int len = methods()->length();
2187 for (int index = 0; index < len; index++) {
2188 Method* m = methods()->at(index);
2189 assert(m->is_method(), "must be method");
2190 f(m);
2191 }
2192 }
2193
2194
2195 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
2196 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2197 if (fs.access_flags().is_static()) {
2198 fieldDescriptor& fd = fs.field_descriptor();
2199 cl->do_field(&fd);
2200 }
2201 }
2202 }
2203
2204
2205 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
2206 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2207 if (fs.access_flags().is_static()) {
2208 fieldDescriptor& fd = fs.field_descriptor();
2209 f(&fd, mirror, CHECK);
2210 }
2211 }
2212 }
2213
2214 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
2215 InstanceKlass* super = superklass();
2216 if (super != nullptr) {
2217 super->do_nonstatic_fields(cl);
2218 }
2219 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2220 fieldDescriptor& fd = fs.field_descriptor();
2221 if (!fd.is_static()) {
2222 cl->do_field(&fd);
2223 }
2224 }
2225 }
2226
2227 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
2228 return a->offset() - b->offset();
2229 }
2230
2231 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
2232 InstanceKlass* super = superklass();
2233 if (super != nullptr) {
2234 super->print_nonstatic_fields(cl);
2235 }
2236 ResourceMark rm;
2237 // In DebugInfo nonstatic fields are sorted by offset.
2238 GrowableArray<FieldInfo> fields_sorted;
2239 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2240 if (!fs.access_flags().is_static()) {
2241 fields_sorted.push(fs.to_FieldInfo());
2242 }
2243 }
2244 int length = fields_sorted.length();
2245 if (length > 0) {
2246 fields_sorted.sort(compare_fields_by_offset);
2247 fieldDescriptor fd;
2248 for (int i = 0; i < length; i++) {
2249 fd.reinitialize(this, fields_sorted.at(i));
2250 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
2251 cl->do_field(&fd);
2252 }
2253 }
2254 }
2255
2256 #ifdef ASSERT
2257 static int linear_search(const Array<Method*>* methods,
2258 const Symbol* name,
2259 const Symbol* signature) {
2260 const int len = methods->length();
2261 for (int index = 0; index < len; index++) {
2262 const Method* const m = methods->at(index);
2263 assert(m->is_method(), "must be method");
2264 if (m->signature() == signature && m->name() == name) {
2265 return index;
2266 }
2267 }
2268 return -1;
2269 }
2270 #endif
2271
2272 bool InstanceKlass::_disable_method_binary_search = false;
2273
2274 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2275 int len = methods->length();
2276 int l = 0;
2277 int h = len - 1;
2278 while (l <= h) {
2279 Method* m = methods->at(l);
2280 if (m->name() == name) {
2281 return l;
2282 }
2283 l++;
2284 }
2285 return -1;
2286 }
2287
2288 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2289 if (_disable_method_binary_search) {
2290 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2291 // At the final stage of dynamic dumping, the methods array may not be sorted
2292 // by ascending addresses of their names, so we can't use binary search anymore.
2293 // However, methods with the same name are still laid out consecutively inside the
2294 // methods array, so let's look for the first one that matches.
2295 return linear_search(methods, name);
2296 }
2297
2298 int len = methods->length();
2299 int l = 0;
2300 int h = len - 1;
2301
2302 // methods are sorted by ascending addresses of their names, so do binary search
2303 while (l <= h) {
2304 int mid = (l + h) >> 1;
2305 Method* m = methods->at(mid);
2306 assert(m->is_method(), "must be method");
2307 int res = m->name()->fast_compare(name);
2308 if (res == 0) {
2309 return mid;
2310 } else if (res < 0) {
2311 l = mid + 1;
2312 } else {
2313 h = mid - 1;
2314 }
2315 }
2316 return -1;
2317 }
2318
2319 // find_method looks up the name/signature in the local methods array
2320 Method* InstanceKlass::find_method(const Symbol* name,
2321 const Symbol* signature) const {
2322 return find_method_impl(name, signature,
2323 OverpassLookupMode::find,
2324 StaticLookupMode::find,
2325 PrivateLookupMode::find);
2326 }
2327
2328 Method* InstanceKlass::find_method_impl(const Symbol* name,
2329 const Symbol* signature,
2330 OverpassLookupMode overpass_mode,
2331 StaticLookupMode static_mode,
2332 PrivateLookupMode private_mode) const {
2333 return InstanceKlass::find_method_impl(methods(),
2334 name,
2335 signature,
2336 overpass_mode,
2337 static_mode,
2338 private_mode);
2339 }
2340
2341 // find_instance_method looks up the name/signature in the local methods array
2342 // and skips over static methods
2343 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2344 const Symbol* name,
2345 const Symbol* signature,
2346 PrivateLookupMode private_mode) {
2347 Method* const meth = InstanceKlass::find_method_impl(methods,
2348 name,
2349 signature,
2350 OverpassLookupMode::find,
2351 StaticLookupMode::skip,
2352 private_mode);
2353 assert(((meth == nullptr) || !meth->is_static()),
2354 "find_instance_method should have skipped statics");
2355 return meth;
2356 }
2357
2358 // find_instance_method looks up the name/signature in the local methods array
2359 // and skips over static methods
2360 Method* InstanceKlass::find_instance_method(const Symbol* name,
2361 const Symbol* signature,
2362 PrivateLookupMode private_mode) const {
2363 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2364 }
2365
2366 // Find looks up the name/signature in the local methods array
2367 // and filters on the overpass, static and private flags
2368 // This returns the first one found
2369 // note that the local methods array can have up to one overpass, one static
2370 // and one instance (private or not) with the same name/signature
2371 Method* InstanceKlass::find_local_method(const Symbol* name,
2372 const Symbol* signature,
2373 OverpassLookupMode overpass_mode,
2374 StaticLookupMode static_mode,
2375 PrivateLookupMode private_mode) const {
2376 return InstanceKlass::find_method_impl(methods(),
2377 name,
2378 signature,
2379 overpass_mode,
2380 static_mode,
2381 private_mode);
2382 }
2383
2384 // Find looks up the name/signature in the local methods array
2385 // and filters on the overpass, static and private flags
2386 // This returns the first one found
2387 // note that the local methods array can have up to one overpass, one static
2388 // and one instance (private or not) with the same name/signature
2389 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2390 const Symbol* name,
2391 const Symbol* signature,
2392 OverpassLookupMode overpass_mode,
2393 StaticLookupMode static_mode,
2394 PrivateLookupMode private_mode) {
2395 return InstanceKlass::find_method_impl(methods,
2396 name,
2397 signature,
2398 overpass_mode,
2399 static_mode,
2400 private_mode);
2401 }
2402
2403 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2404 const Symbol* name,
2405 const Symbol* signature) {
2406 return InstanceKlass::find_method_impl(methods,
2407 name,
2408 signature,
2409 OverpassLookupMode::find,
2410 StaticLookupMode::find,
2411 PrivateLookupMode::find);
2412 }
2413
2414 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2415 const Symbol* name,
2416 const Symbol* signature,
2417 OverpassLookupMode overpass_mode,
2418 StaticLookupMode static_mode,
2419 PrivateLookupMode private_mode) {
2420 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2421 return hit >= 0 ? methods->at(hit): nullptr;
2422 }
2423
2424 // true if method matches signature and conforms to skipping_X conditions.
2425 static bool method_matches(const Method* m,
2426 const Symbol* signature,
2427 bool skipping_overpass,
2428 bool skipping_static,
2429 bool skipping_private) {
2430 return ((m->signature() == signature) &&
2431 (!skipping_overpass || !m->is_overpass()) &&
2432 (!skipping_static || !m->is_static()) &&
2433 (!skipping_private || !m->is_private()));
2434 }
2435
2436 // Used directly for default_methods to find the index into the
2437 // default_vtable_indices, and indirectly by find_method
2438 // find_method_index looks in the local methods array to return the index
2439 // of the matching name/signature. If, overpass methods are being ignored,
2440 // the search continues to find a potential non-overpass match. This capability
2441 // is important during method resolution to prefer a static method, for example,
2442 // over an overpass method.
2443 // There is the possibility in any _method's array to have the same name/signature
2444 // for a static method, an overpass method and a local instance method
2445 // To correctly catch a given method, the search criteria may need
2446 // to explicitly skip the other two. For local instance methods, it
2447 // is often necessary to skip private methods
2448 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2449 const Symbol* name,
2450 const Symbol* signature,
2451 OverpassLookupMode overpass_mode,
2452 StaticLookupMode static_mode,
2453 PrivateLookupMode private_mode) {
2454 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2455 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2456 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2457 const int hit = quick_search(methods, name);
2458 if (hit != -1) {
2459 const Method* const m = methods->at(hit);
2460
2461 // Do linear search to find matching signature. First, quick check
2462 // for common case, ignoring overpasses if requested.
2463 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2464 return hit;
2465 }
2466
2467 // search downwards through overloaded methods
2468 int i;
2469 for (i = hit - 1; i >= 0; --i) {
2470 const Method* const m = methods->at(i);
2471 assert(m->is_method(), "must be method");
2472 if (m->name() != name) {
2473 break;
2474 }
2475 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2476 return i;
2477 }
2478 }
2479 // search upwards
2480 for (i = hit + 1; i < methods->length(); ++i) {
2481 const Method* const m = methods->at(i);
2482 assert(m->is_method(), "must be method");
2483 if (m->name() != name) {
2484 break;
2485 }
2486 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2487 return i;
2488 }
2489 }
2490 // not found
2491 #ifdef ASSERT
2492 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2493 linear_search(methods, name, signature);
2494 assert(-1 == index, "binary search should have found entry %d", index);
2495 #endif
2496 }
2497 return -1;
2498 }
2499
2500 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2501 return find_method_by_name(methods(), name, end);
2502 }
2503
2504 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2505 const Symbol* name,
2506 int* end_ptr) {
2507 assert(end_ptr != nullptr, "just checking");
2508 int start = quick_search(methods, name);
2509 int end = start + 1;
2510 if (start != -1) {
2511 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2512 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2513 *end_ptr = end;
2514 return start;
2515 }
2516 return -1;
2517 }
2518
2519 // uncached_lookup_method searches both the local class methods array and all
2520 // superclasses methods arrays, skipping any overpass methods in superclasses,
2521 // and possibly skipping private methods.
2522 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2523 const Symbol* signature,
2524 OverpassLookupMode overpass_mode,
2525 PrivateLookupMode private_mode) const {
2526 OverpassLookupMode overpass_local_mode = overpass_mode;
2527 const Klass* klass = this;
2528 while (klass != nullptr) {
2529 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2530 signature,
2531 overpass_local_mode,
2532 StaticLookupMode::find,
2533 private_mode);
2534 if (method != nullptr) {
2535 return method;
2536 }
2537 if (name == vmSymbols::object_initializer_name()) {
2538 break; // <init> is never inherited
2539 }
2540 klass = klass->super();
2541 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2542 }
2543 return nullptr;
2544 }
2545
2546 #ifdef ASSERT
2547 // search through class hierarchy and return true if this class or
2548 // one of the superclasses was redefined
2549 bool InstanceKlass::has_redefined_this_or_super() const {
2550 const Klass* klass = this;
2551 while (klass != nullptr) {
2552 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2553 return true;
2554 }
2555 klass = klass->super();
2556 }
2557 return false;
2558 }
2559 #endif
2560
2561 // lookup a method in the default methods list then in all transitive interfaces
2562 // Do NOT return private or static methods
2563 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2564 Symbol* signature) const {
2565 Method* m = nullptr;
2566 if (default_methods() != nullptr) {
2567 m = find_method(default_methods(), name, signature);
2568 }
2569 // Look up interfaces
2570 if (m == nullptr) {
2571 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2572 }
2573 return m;
2574 }
2575
2576 // lookup a method in all the interfaces that this class implements
2577 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2578 // They should only be found in the initial InterfaceMethodRef
2579 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2580 Symbol* signature,
2581 DefaultsLookupMode defaults_mode) const {
2582 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2583 int num_ifs = all_ifs->length();
2584 InstanceKlass *ik = nullptr;
2585 for (int i = 0; i < num_ifs; i++) {
2586 ik = all_ifs->at(i);
2587 Method* m = ik->lookup_method(name, signature);
2588 if (m != nullptr && m->is_public() && !m->is_static() &&
2589 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2590 return m;
2591 }
2592 }
2593 return nullptr;
2594 }
2595
2596 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2597 :_st(st), _verbose(verbose) {
2598 ResourceMark rm;
2599 _st->print("%-18s ", "KlassAddr");
2600 _st->print("%-4s ", "Size");
2601 _st->print("%-20s ", "State");
2602 _st->print("%-7s ", "Flags");
2603 _st->print("%-5s ", "ClassName");
2604 _st->cr();
2605 }
2606
2607 void PrintClassClosure::do_klass(Klass* k) {
2608 ResourceMark rm;
2609 // klass pointer
2610 _st->print(PTR_FORMAT " ", p2i(k));
2611 // klass size
2612 _st->print("%4d ", k->size());
2613 // initialization state
2614 if (k->is_instance_klass()) {
2615 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2616 } else {
2617 _st->print("%-20s ","");
2618 }
2619 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2620 char buf[10];
2621 int i = 0;
2622 if (k->has_finalizer()) buf[i++] = 'F';
2623 if (k->is_instance_klass()) {
2624 InstanceKlass* ik = InstanceKlass::cast(k);
2625 if (ik->has_final_method()) buf[i++] = 'f';
2626 if (ik->is_rewritten()) buf[i++] = 'W';
2627 if (ik->is_contended()) buf[i++] = 'C';
2628 if (ik->has_been_redefined()) buf[i++] = 'R';
2629 if (ik->is_shared()) buf[i++] = 'S';
2630 }
2631 buf[i++] = '\0';
2632 _st->print("%-7s ", buf);
2633 // klass name
2634 _st->print("%-5s ", k->external_name());
2635 // end
2636 _st->cr();
2637 if (_verbose) {
2638 k->print_on(_st);
2639 }
2640 }
2641
2642 /* jni_id_for for jfieldIds only */
2643 JNIid* InstanceKlass::jni_id_for(int offset) {
2644 MutexLocker ml(JfieldIdCreation_lock);
2645 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2646 if (probe == nullptr) {
2647 // Allocate new static field identifier
2648 probe = new JNIid(this, offset, jni_ids());
2649 set_jni_ids(probe);
2650 }
2651 return probe;
2652 }
2653
2654 u2 InstanceKlass::enclosing_method_data(int offset) const {
2655 const Array<jushort>* const inner_class_list = inner_classes();
2656 if (inner_class_list == nullptr) {
2657 return 0;
2658 }
2659 const int length = inner_class_list->length();
2660 if (length % inner_class_next_offset == 0) {
2661 return 0;
2662 }
2663 const int index = length - enclosing_method_attribute_size;
2664 assert(offset < enclosing_method_attribute_size, "invalid offset");
2665 return inner_class_list->at(index + offset);
2666 }
2667
2668 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2669 u2 method_index) {
2670 Array<jushort>* inner_class_list = inner_classes();
2671 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2672 int length = inner_class_list->length();
2673 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2674 int index = length - enclosing_method_attribute_size;
2675 inner_class_list->at_put(
2676 index + enclosing_method_class_index_offset, class_index);
2677 inner_class_list->at_put(
2678 index + enclosing_method_method_index_offset, method_index);
2679 }
2680 }
2681
2682 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2683 if (method->is_old() && !method->is_obsolete()) {
2684 // If the method passed in is old (but not obsolete), use the current version.
2685 method = method_with_idnum((int)idnum);
2686 assert(method != nullptr, "old and but not obsolete, so should exist");
2687 }
2688 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2689 Atomic::release_store(&jmeths[idnum + 1], new_id);
2690 return new_id;
2691 }
2692
2693 // Allocate the jmethodID cache.
2694 static jmethodID* create_jmethod_id_cache(size_t size) {
2695 jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2696 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2697 // cache size is stored in element[0], other elements offset by one
2698 jmeths[0] = (jmethodID)size;
2699 return jmeths;
2700 }
2701
2702 // When reading outside a lock, use this.
2703 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2704 return Atomic::load_acquire(&_methods_jmethod_ids);
2705 }
2706
2707 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2708 Atomic::release_store(&_methods_jmethod_ids, jmeths);
2709 }
2710
2711 // Lookup or create a jmethodID.
2712 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2713 int idnum = method->method_idnum();
2714 jmethodID* jmeths = methods_jmethod_ids_acquire();
2715
2716 // We use a double-check locking idiom here because this cache is
2717 // performance sensitive. In the normal system, this cache only
2718 // transitions from null to non-null which is safe because we use
2719 // release_set_methods_jmethod_ids() to advertise the new cache.
2720 // A partially constructed cache should never be seen by a racing
2721 // thread. We also use release_store() to save a new jmethodID
2722 // in the cache so a partially constructed jmethodID should never be
2723 // seen either. Cache reads of existing jmethodIDs proceed without a
2724 // lock, but cache writes of a new jmethodID requires uniqueness and
2725 // creation of the cache itself requires no leaks so a lock is
2726 // acquired in those two cases.
2727 //
2728 // If the RedefineClasses() API has been used, then this cache grows
2729 // in the redefinition safepoint.
2730
2731 if (jmeths == nullptr) {
2732 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2733 jmeths = _methods_jmethod_ids;
2734 // Still null?
2735 if (jmeths == nullptr) {
2736 size_t size = idnum_allocated_count();
2737 assert(size > (size_t)idnum, "should already have space");
2738 jmeths = create_jmethod_id_cache(size);
2739 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2740
2741 // publish jmeths
2742 release_set_methods_jmethod_ids(jmeths);
2743 return new_id;
2744 }
2745 }
2746
2747 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2748 if (id == nullptr) {
2749 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2750 id = jmeths[idnum + 1];
2751 // Still null?
2752 if (id == nullptr) {
2753 return update_jmethod_id(jmeths, method, idnum);
2754 }
2755 }
2756 return id;
2757 }
2758
2759 void InstanceKlass::update_methods_jmethod_cache() {
2760 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2761 jmethodID* cache = _methods_jmethod_ids;
2762 if (cache != nullptr) {
2763 size_t size = idnum_allocated_count();
2764 size_t old_size = (size_t)cache[0];
2765 if (old_size < size + 1) {
2766 // Allocate a larger one and copy entries to the new one.
2767 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2768 jmethodID* new_cache = create_jmethod_id_cache(size);
2769
2770 for (int i = 1; i <= (int)old_size; i++) {
2771 new_cache[i] = cache[i];
2772 }
2773 _methods_jmethod_ids = new_cache;
2774 FREE_C_HEAP_ARRAY(jmethodID, cache);
2775 }
2776 }
2777 }
2778
2779 // Make a jmethodID for all methods in this class. This makes getting all method
2780 // ids much, much faster with classes with more than 8
2781 // methods, and has a *substantial* effect on performance with jvmti
2782 // code that loads all jmethodIDs for all classes.
2783 void InstanceKlass::make_methods_jmethod_ids() {
2784 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2785 jmethodID* jmeths = _methods_jmethod_ids;
2786 if (jmeths == nullptr) {
2787 jmeths = create_jmethod_id_cache(idnum_allocated_count());
2788 release_set_methods_jmethod_ids(jmeths);
2789 }
2790
2791 int length = methods()->length();
2792 for (int index = 0; index < length; index++) {
2793 Method* m = methods()->at(index);
2794 int idnum = m->method_idnum();
2795 assert(!m->is_old(), "should not have old methods or I'm confused");
2796 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2797 if (!m->is_overpass() && // skip overpasses
2798 id == nullptr) {
2799 id = Method::make_jmethod_id(class_loader_data(), m);
2800 Atomic::release_store(&jmeths[idnum + 1], id);
2801 }
2802 }
2803 }
2804
2805 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2806 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2807 int idnum = method->method_idnum();
2808 jmethodID* jmeths = methods_jmethod_ids_acquire();
2809 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2810 }
2811
2812 inline DependencyContext InstanceKlass::dependencies() {
2813 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2814 return dep_context;
2815 }
2816
2817 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2818 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2819 }
2820
2821 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2822 assert_lock_strong(CodeCache_lock);
2823 dependencies().add_dependent_nmethod(nm);
2824 }
2825
2826 void InstanceKlass::clean_dependency_context() {
2827 dependencies().clean_unloading_dependents();
2828 }
2829
2830 #ifndef PRODUCT
2831 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2832 dependencies().print_dependent_nmethods(verbose);
2833 }
2834
2835 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2836 return dependencies().is_dependent_nmethod(nm);
2837 }
2838 #endif //PRODUCT
2839
2840 void InstanceKlass::clean_weak_instanceklass_links() {
2841 clean_implementors_list();
2842 clean_method_data();
2843 }
2844
2845 void InstanceKlass::clean_implementors_list() {
2846 assert(is_loader_alive(), "this klass should be live");
2847 if (is_interface()) {
2848 assert (ClassUnloading, "only called for ClassUnloading");
2849 for (;;) {
2850 // Use load_acquire due to competing with inserts
2851 InstanceKlass* volatile* iklass = adr_implementor();
2852 assert(iklass != nullptr, "Klass must not be null");
2853 InstanceKlass* impl = Atomic::load_acquire(iklass);
2854 if (impl != nullptr && !impl->is_loader_alive()) {
2855 // null this field, might be an unloaded instance klass or null
2856 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2857 // Successfully unlinking implementor.
2858 if (log_is_enabled(Trace, class, unload)) {
2859 ResourceMark rm;
2860 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2861 }
2862 return;
2863 }
2864 } else {
2865 return;
2866 }
2867 }
2868 }
2869 }
2870
2871 void InstanceKlass::clean_method_data() {
2872 for (int m = 0; m < methods()->length(); m++) {
2873 MethodData* mdo = methods()->at(m)->method_data();
2874 if (mdo != nullptr) {
2875 mdo->clean_method_data(/*always_clean*/false);
2876 }
2877 }
2878 }
2879
2880 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2881 Klass::metaspace_pointers_do(it);
2882
2883 if (log_is_enabled(Trace, aot)) {
2884 ResourceMark rm;
2885 log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2886 }
2887
2888 it->push(&_annotations);
2889 it->push((Klass**)&_array_klasses);
2890 if (!is_rewritten()) {
2891 it->push(&_constants, MetaspaceClosure::_writable);
2892 } else {
2893 it->push(&_constants);
2894 }
2895 it->push(&_inner_classes);
2896 #if INCLUDE_JVMTI
2897 it->push(&_previous_versions);
2898 #endif
2899 #if INCLUDE_CDS
2900 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2901 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2902 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2903 // The length check on the _methods is necessary because classes which don't have any
2904 // methods share the Universe::_the_empty_method_array which is in the RO region.
2905 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2906 // To handle jsr bytecode, new Method* maybe stored into _methods
2907 it->push(&_methods, MetaspaceClosure::_writable);
2908 } else {
2909 #endif
2910 it->push(&_methods);
2911 #if INCLUDE_CDS
2912 }
2913 #endif
2914 it->push(&_default_methods);
2915 it->push(&_local_interfaces);
2916 it->push(&_transitive_interfaces);
2917 it->push(&_method_ordering);
2918 if (!is_rewritten()) {
2919 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2920 } else {
2921 it->push(&_default_vtable_indices);
2922 }
2923
2924 it->push(&_fieldinfo_stream);
2925 it->push(&_fieldinfo_search_table);
2926 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2927 it->push(&_fields_status, MetaspaceClosure::_writable);
2928
2929 if (itable_length() > 0) {
2930 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2931 int method_table_offset_in_words = ioe->offset()/wordSize;
2932 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2933
2934 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2935 / itableOffsetEntry::size();
2936
2937 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2938 if (ioe->interface_klass() != nullptr) {
2939 it->push(ioe->interface_klass_addr());
2940 itableMethodEntry* ime = ioe->first_method_entry(this);
2941 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2942 for (int index = 0; index < n; index ++) {
2943 it->push(ime[index].method_addr());
2944 }
2945 }
2946 }
2947 }
2948
2949 it->push(&_nest_host);
2950 it->push(&_nest_members);
2951 it->push(&_permitted_subclasses);
2952 it->push(&_loadable_descriptors);
2953 it->push(&_record_components);
2954 it->push(&_inline_layout_info_array, MetaspaceClosure::_writable);
2955 }
2956
2957 #if INCLUDE_CDS
2958 void InstanceKlass::remove_unshareable_info() {
2959
2960 if (is_linked()) {
2961 assert(can_be_verified_at_dumptime(), "must be");
2962 // Remember this so we can avoid walking the hierarchy at runtime.
2963 set_verified_at_dump_time();
2964 }
2965
2966 _misc_flags.set_has_init_deps_processed(false);
2967
2968 Klass::remove_unshareable_info();
2969
2970 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2971 // Classes are attempted to link during dumping and may fail,
2972 // but these classes are still in the dictionary and class list in CLD.
2973 // If the class has failed verification, there is nothing else to remove.
2974 return;
2975 }
2976
2977 // Reset to the 'allocated' state to prevent any premature accessing to
2978 // a shared class at runtime while the class is still being loaded and
2979 // restored. A class' init_state is set to 'loaded' at runtime when it's
2980 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2981 _init_state = allocated;
2982
2983 { // Otherwise this needs to take out the Compile_lock.
2984 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2985 init_implementor();
2986 }
2987
2988 // Call remove_unshareable_info() on other objects that belong to this class, except
2989 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2990 // ArchiveBuilder::make_klasses_shareable(),
2991
2992 for (int i = 0; i < methods()->length(); i++) {
2993 Method* m = methods()->at(i);
2994 m->remove_unshareable_info();
2995 }
2996
2997 // do array classes also.
2998 if (array_klasses() != nullptr) {
2999 array_klasses()->remove_unshareable_info();
3000 }
3001
3002 // These are not allocated from metaspace. They are safe to set to nullptr.
3003 _source_debug_extension = nullptr;
3004 _dep_context = nullptr;
3005 _osr_nmethods_head = nullptr;
3006 #if INCLUDE_JVMTI
3007 _breakpoints = nullptr;
3008 _previous_versions = nullptr;
3009 _cached_class_file = nullptr;
3010 _jvmti_cached_class_field_map = nullptr;
3011 #endif
3012
3013 _init_thread = nullptr;
3014 _methods_jmethod_ids = nullptr;
3015 _jni_ids = nullptr;
3016 _oop_map_cache = nullptr;
3017 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
3018 // keep _nest_host
3019 } else {
3020 // clear _nest_host to ensure re-load at runtime
3021 _nest_host = nullptr;
3022 }
3023 init_shared_package_entry();
3024 _dep_context_last_cleaned = 0;
3025 DEBUG_ONLY(_shared_class_load_count = 0);
3026
3027 remove_unshareable_flags();
3028
3029 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
3030 }
3031
3032 void InstanceKlass::remove_unshareable_flags() {
3033 // clear all the flags/stats that shouldn't be in the archived version
3034 assert(!is_scratch_class(), "must be");
3035 assert(!has_been_redefined(), "must be");
3036 #if INCLUDE_JVMTI
3037 set_is_being_redefined(false);
3038 #endif
3039 set_has_resolved_methods(false);
3040 }
3041
3042 void InstanceKlass::remove_java_mirror() {
3043 Klass::remove_java_mirror();
3044
3045 // do array classes also.
3046 if (array_klasses() != nullptr) {
3047 array_klasses()->remove_java_mirror();
3048 }
3049 }
3050
3051 void InstanceKlass::init_shared_package_entry() {
3052 assert(CDSConfig::is_dumping_archive(), "must be");
3053 #if !INCLUDE_CDS_JAVA_HEAP
3054 _package_entry = nullptr;
3055 #else
3056 if (CDSConfig::is_dumping_full_module_graph()) {
3057 if (defined_by_other_loaders()) {
3058 _package_entry = nullptr;
3059 } else {
3060 _package_entry = PackageEntry::get_archived_entry(_package_entry);
3061 }
3062 } else if (CDSConfig::is_dumping_dynamic_archive() &&
3063 CDSConfig::is_using_full_module_graph() &&
3064 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
3065 // _package_entry is an archived package in the base archive. Leave it as is.
3066 } else {
3067 _package_entry = nullptr;
3068 }
3069 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
3070 #endif
3071 }
3072
3073 void InstanceKlass::compute_has_loops_flag_for_methods() {
3074 Array<Method*>* methods = this->methods();
3075 for (int index = 0; index < methods->length(); ++index) {
3076 Method* m = methods->at(index);
3077 if (!m->is_overpass()) { // work around JDK-8305771
3078 m->compute_has_loops_flag();
3079 }
3080 }
3081 }
3082
3083 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
3084 PackageEntry* pkg_entry, TRAPS) {
3085 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
3086 // before the InstanceKlass is added to the SystemDictionary. Make
3087 // sure the current state is <loaded.
3088 assert(!is_loaded(), "invalid init state");
3089 assert(!shared_loading_failed(), "Must not try to load failed class again");
3090 set_package(loader_data, pkg_entry, CHECK);
3091 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
3092
3093 if (is_inline_klass()) {
3094 InlineKlass::cast(this)->initialize_calling_convention(CHECK);
3095 }
3096
3097 Array<Method*>* methods = this->methods();
3098 int num_methods = methods->length();
3099 for (int index = 0; index < num_methods; ++index) {
3100 methods->at(index)->restore_unshareable_info(CHECK);
3101 }
3102 #if INCLUDE_JVMTI
3103 if (JvmtiExport::has_redefined_a_class()) {
3104 // Reinitialize vtable because RedefineClasses may have changed some
3105 // entries in this vtable for super classes so the CDS vtable might
3106 // point to old or obsolete entries. RedefineClasses doesn't fix up
3107 // vtables in the shared system dictionary, only the main one.
3108 // It also redefines the itable too so fix that too.
3109 // First fix any default methods that point to a super class that may
3110 // have been redefined.
3111 bool trace_name_printed = false;
3112 adjust_default_methods(&trace_name_printed);
3113 if (verified_at_dump_time()) {
3114 // Initialize vtable and itable for classes which can be verified at dump time.
3115 // Unlinked classes such as old classes with major version < 50 cannot be verified
3116 // at dump time.
3117 vtable().initialize_vtable();
3118 itable().initialize_itable();
3119 }
3120 }
3121 #endif // INCLUDE_JVMTI
3122
3123 // restore constant pool resolved references
3124 constants()->restore_unshareable_info(CHECK);
3125
3126 if (array_klasses() != nullptr) {
3127 // To get a consistent list of classes we need MultiArray_lock to ensure
3128 // array classes aren't observed while they are being restored.
3129 RecursiveLocker rl(MultiArray_lock, THREAD);
3130 assert(this == ObjArrayKlass::cast(array_klasses())->bottom_klass(), "sanity");
3131 // Array classes have null protection domain.
3132 // --> see ArrayKlass::complete_create_array_klass()
3133 if (class_loader_data() == nullptr) {
3134 ResourceMark rm(THREAD);
3135 log_debug(cds)(" loader_data %s ", loader_data == nullptr ? "nullptr" : "non null");
3136 log_debug(cds)(" this %s array_klasses %s ", this->name()->as_C_string(), array_klasses()->name()->as_C_string());
3137 }
3138 assert(!array_klasses()->is_refined_objArray_klass(), "must be non-refined objarrayklass");
3139 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
3140 }
3141
3142 // Initialize @ValueBased class annotation if not already set in the archived klass.
3143 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
3144 set_is_value_based();
3145 }
3146
3147 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
3148 }
3149
3150 // Check if a class or any of its supertypes has a version older than 50.
3151 // CDS will not perform verification of old classes during dump time because
3152 // without changing the old verifier, the verification constraint cannot be
3153 // retrieved during dump time.
3154 // Verification of archived old classes will be performed during run time.
3155 bool InstanceKlass::can_be_verified_at_dumptime() const {
3156 if (MetaspaceShared::is_in_shared_metaspace(this)) {
3157 // This is a class that was dumped into the base archive, so we know
3158 // it was verified at dump time.
3159 return true;
3160 }
3161 if (major_version() < 50 /*JAVA_6_VERSION*/) {
3162 return false;
3163 }
3164 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
3165 return false;
3166 }
3167 Array<InstanceKlass*>* interfaces = local_interfaces();
3168 int len = interfaces->length();
3169 for (int i = 0; i < len; i++) {
3170 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
3171 return false;
3172 }
3173 }
3174 return true;
3175 }
3176
3177 #endif // INCLUDE_CDS
3178
3179 #if INCLUDE_JVMTI
3180 static void clear_all_breakpoints(Method* m) {
3181 m->clear_all_breakpoints();
3182 }
3183 #endif
3184
3185 void InstanceKlass::unload_class(InstanceKlass* ik) {
3186
3187 if (ik->is_scratch_class()) {
3188 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
3189 return;
3190 }
3191 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
3192
3193 // Release dependencies.
3194 ik->dependencies().remove_all_dependents();
3195
3196 // notify the debugger
3197 if (JvmtiExport::should_post_class_unload()) {
3198 JvmtiExport::post_class_unload(ik);
3199 }
3200
3201 // notify ClassLoadingService of class unload
3202 ClassLoadingService::notify_class_unloaded(ik);
3203
3204 SystemDictionaryShared::handle_class_unloading(ik);
3205
3206 if (log_is_enabled(Info, class, unload)) {
3207 ResourceMark rm;
3208 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
3209 }
3210
3211 Events::log_class_unloading(Thread::current(), ik);
3212
3213 #if INCLUDE_JFR
3214 assert(ik != nullptr, "invariant");
3215 EventClassUnload event;
3216 event.set_unloadedClass(ik);
3217 event.set_definingClassLoader(ik->class_loader_data());
3218 event.commit();
3219 #endif
3220 }
3221
3222 static void method_release_C_heap_structures(Method* m) {
3223 m->release_C_heap_structures();
3224 }
3225
3226 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
3227 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
3228 // Clean up C heap
3229 Klass::release_C_heap_structures();
3230
3231 // Deallocate and call destructors for MDO mutexes
3232 if (release_sub_metadata) {
3233 methods_do(method_release_C_heap_structures);
3234 }
3235
3236 // Deallocate oop map cache
3237 if (_oop_map_cache != nullptr) {
3238 delete _oop_map_cache;
3239 _oop_map_cache = nullptr;
3240 }
3241
3242 // Deallocate JNI identifiers for jfieldIDs
3243 JNIid::deallocate(jni_ids());
3244 set_jni_ids(nullptr);
3245
3246 jmethodID* jmeths = _methods_jmethod_ids;
3247 if (jmeths != nullptr) {
3248 release_set_methods_jmethod_ids(nullptr);
3249 FreeHeap(jmeths);
3250 }
3251
3252 assert(_dep_context == nullptr,
3253 "dependencies should already be cleaned");
3254
3255 #if INCLUDE_JVMTI
3256 // Deallocate breakpoint records
3257 if (breakpoints() != nullptr) {
3258 methods_do(clear_all_breakpoints);
3259 assert(breakpoints() == nullptr, "should have cleared breakpoints");
3260 }
3261
3262 // deallocate the cached class file
3263 if (_cached_class_file != nullptr) {
3264 os::free(_cached_class_file);
3265 _cached_class_file = nullptr;
3266 }
3267 #endif
3268
3269 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
3270
3271 if (release_sub_metadata) {
3272 constants()->release_C_heap_structures();
3273 }
3274 }
3275
3276 // The constant pool is on stack if any of the methods are executing or
3277 // referenced by handles.
3278 bool InstanceKlass::on_stack() const {
3279 return _constants->on_stack();
3280 }
3281
3282 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
3283 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
3284 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3285
3286 // minor and major version numbers of class file
3287 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
3288 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3289 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
3290 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3291
3292 bool InstanceKlass::supports_inline_types() const {
3293 return major_version() >= Verifier::VALUE_TYPES_MAJOR_VERSION && minor_version() == Verifier::JAVA_PREVIEW_MINOR_VERSION;
3294 }
3295
3296 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
3297 for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3298 if (ik->constants()->version() == version) {
3299 return ik;
3300 }
3301 }
3302 return nullptr;
3303 }
3304
3305 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3306 if (array == nullptr) {
3307 _source_debug_extension = nullptr;
3308 } else {
3309 // Adding one to the attribute length in order to store a null terminator
3310 // character could cause an overflow because the attribute length is
3311 // already coded with an u4 in the classfile, but in practice, it's
3312 // unlikely to happen.
3313 assert((length+1) > length, "Overflow checking");
3314 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3315 for (int i = 0; i < length; i++) {
3316 sde[i] = array[i];
3317 }
3318 sde[length] = '\0';
3319 _source_debug_extension = sde;
3320 }
3321 }
3322
3323 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3324 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3325 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3326
3327 const char* InstanceKlass::signature_name() const {
3328 return signature_name_of_carrier(JVM_SIGNATURE_CLASS);
3329 }
3330
3331 const char* InstanceKlass::signature_name_of_carrier(char c) const {
3332 // Get the internal name as a c string
3333 const char* src = (const char*) (name()->as_C_string());
3334 const int src_length = (int)strlen(src);
3335
3336 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3337
3338 // Add L or Q as type indicator
3339 int dest_index = 0;
3340 dest[dest_index++] = c;
3341
3342 // Add the actual class name
3343 for (int src_index = 0; src_index < src_length; ) {
3344 dest[dest_index++] = src[src_index++];
3345 }
3346
3347 if (is_hidden()) { // Replace the last '+' with a '.'.
3348 for (int index = (int)src_length; index > 0; index--) {
3349 if (dest[index] == '+') {
3350 dest[index] = JVM_SIGNATURE_DOT;
3351 break;
3352 }
3353 }
3354 }
3355
3356 // Add the semicolon and the null
3357 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3358 dest[dest_index] = '\0';
3359 return dest;
3360 }
3361
3362 ModuleEntry* InstanceKlass::module() const {
3363 if (is_hidden() &&
3364 in_unnamed_package() &&
3365 class_loader_data()->has_class_mirror_holder()) {
3366 // For a non-strong hidden class defined to an unnamed package,
3367 // its (class held) CLD will not have an unnamed module created for it.
3368 // Two choices to find the correct ModuleEntry:
3369 // 1. If hidden class is within a nest, use nest host's module
3370 // 2. Find the unnamed module off from the class loader
3371 // For now option #2 is used since a nest host is not set until
3372 // after the instance class is created in jvm_lookup_define_class().
3373 if (class_loader_data()->is_boot_class_loader_data()) {
3374 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3375 } else {
3376 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3377 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3378 return java_lang_Module::module_entry(module);
3379 }
3380 }
3381
3382 // Class is in a named package
3383 if (!in_unnamed_package()) {
3384 return _package_entry->module();
3385 }
3386
3387 // Class is in an unnamed package, return its loader's unnamed module
3388 return class_loader_data()->unnamed_module();
3389 }
3390
3391 bool InstanceKlass::in_javabase_module() const {
3392 return module()->name() == vmSymbols::java_base();
3393 }
3394
3395 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3396
3397 // ensure java/ packages only loaded by boot or platform builtin loaders
3398 // not needed for shared class since CDS does not archive prohibited classes.
3399 if (!is_shared()) {
3400 check_prohibited_package(name(), loader_data, CHECK);
3401 }
3402
3403 if (is_shared() && _package_entry != nullptr) {
3404 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3405 // we can use the saved package
3406 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3407 return;
3408 } else {
3409 _package_entry = nullptr;
3410 }
3411 }
3412
3413 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3414 // it returns, so we need to decrement it when the current function exits.
3415 TempNewSymbol from_class_name =
3416 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3417
3418 Symbol* pkg_name;
3419 if (pkg_entry != nullptr) {
3420 pkg_name = pkg_entry->name();
3421 } else {
3422 pkg_name = from_class_name;
3423 }
3424
3425 if (pkg_name != nullptr && loader_data != nullptr) {
3426
3427 // Find in class loader's package entry table.
3428 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3429
3430 // If the package name is not found in the loader's package
3431 // entry table, it is an indication that the package has not
3432 // been defined. Consider it defined within the unnamed module.
3433 if (_package_entry == nullptr) {
3434
3435 if (!ModuleEntryTable::javabase_defined()) {
3436 // Before java.base is defined during bootstrapping, define all packages in
3437 // the java.base module. If a non-java.base package is erroneously placed
3438 // in the java.base module it will be caught later when java.base
3439 // is defined by ModuleEntryTable::verify_javabase_packages check.
3440 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3441 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3442 } else {
3443 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3444 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3445 }
3446
3447 // A package should have been successfully created
3448 DEBUG_ONLY(ResourceMark rm(THREAD));
3449 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3450 name()->as_C_string(), loader_data->loader_name_and_id());
3451 }
3452
3453 if (log_is_enabled(Debug, module)) {
3454 ResourceMark rm(THREAD);
3455 ModuleEntry* m = _package_entry->module();
3456 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3457 external_name(),
3458 pkg_name->as_C_string(),
3459 loader_data->loader_name_and_id(),
3460 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3461 }
3462 } else {
3463 ResourceMark rm(THREAD);
3464 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3465 external_name(),
3466 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3467 UNNAMED_MODULE);
3468 }
3469 }
3470
3471 // Function set_classpath_index ensures that for a non-null _package_entry
3472 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3473 // It then sets the classpath_index in the package entry record.
3474 //
3475 // The classpath_index field is used to find the entry on the boot loader class
3476 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3477 // in an unnamed module. It is also used to indicate (for all packages whose
3478 // classes are loaded by the boot loader) that at least one of the package's
3479 // classes has been loaded.
3480 void InstanceKlass::set_classpath_index(s2 path_index) {
3481 if (_package_entry != nullptr) {
3482 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3483 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3484 assert(path_index != -1, "Unexpected classpath_index");
3485 _package_entry->set_classpath_index(path_index);
3486 }
3487 }
3488
3489 // different versions of is_same_class_package
3490
3491 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3492 oop classloader1 = this->class_loader();
3493 PackageEntry* classpkg1 = this->package();
3494 if (class2->is_objArray_klass()) {
3495 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3496 }
3497
3498 oop classloader2;
3499 PackageEntry* classpkg2;
3500 if (class2->is_instance_klass()) {
3501 classloader2 = class2->class_loader();
3502 classpkg2 = class2->package();
3503 } else {
3504 assert(class2->is_typeArray_klass(), "should be type array");
3505 classloader2 = nullptr;
3506 classpkg2 = nullptr;
3507 }
3508
3509 // Same package is determined by comparing class loader
3510 // and package entries. Both must be the same. This rule
3511 // applies even to classes that are defined in the unnamed
3512 // package, they still must have the same class loader.
3513 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3514 return true;
3515 }
3516
3517 return false;
3518 }
3519
3520 // return true if this class and other_class are in the same package. Classloader
3521 // and classname information is enough to determine a class's package
3522 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3523 const Symbol* other_class_name) const {
3524 if (class_loader() != other_class_loader) {
3525 return false;
3526 }
3527 if (name()->fast_compare(other_class_name) == 0) {
3528 return true;
3529 }
3530
3531 {
3532 ResourceMark rm;
3533
3534 bool bad_class_name = false;
3535 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3536 if (bad_class_name) {
3537 return false;
3538 }
3539 // Check that package_from_class_name() returns null, not "", if there is no package.
3540 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3541
3542 const Symbol* const this_package_name =
3543 this->package() != nullptr ? this->package()->name() : nullptr;
3544
3545 if (this_package_name == nullptr || other_pkg == nullptr) {
3546 // One of the two doesn't have a package. Only return true if the other
3547 // one also doesn't have a package.
3548 return this_package_name == other_pkg;
3549 }
3550
3551 // Check if package is identical
3552 return this_package_name->fast_compare(other_pkg) == 0;
3553 }
3554 }
3555
3556 static bool is_prohibited_package_slow(Symbol* class_name) {
3557 // Caller has ResourceMark
3558 int length;
3559 jchar* unicode = class_name->as_unicode(length);
3560 return (length >= 5 &&
3561 unicode[0] == 'j' &&
3562 unicode[1] == 'a' &&
3563 unicode[2] == 'v' &&
3564 unicode[3] == 'a' &&
3565 unicode[4] == '/');
3566 }
3567
3568 // Only boot and platform class loaders can define classes in "java/" packages.
3569 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3570 ClassLoaderData* loader_data,
3571 TRAPS) {
3572 if (!loader_data->is_boot_class_loader_data() &&
3573 !loader_data->is_platform_class_loader_data() &&
3574 class_name != nullptr && class_name->utf8_length() >= 5) {
3575 ResourceMark rm(THREAD);
3576 bool prohibited;
3577 const u1* base = class_name->base();
3578 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3579 prohibited = is_prohibited_package_slow(class_name);
3580 } else {
3581 char* name = class_name->as_C_string();
3582 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3583 }
3584 if (prohibited) {
3585 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3586 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3587 char* name = pkg_name->as_C_string();
3588 const char* class_loader_name = loader_data->loader_name_and_id();
3589 StringUtils::replace_no_expand(name, "/", ".");
3590 const char* msg_text1 = "Class loader (instance of): ";
3591 const char* msg_text2 = " tried to load prohibited package name: ";
3592 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3593 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3594 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3595 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3596 }
3597 }
3598 return;
3599 }
3600
3601 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3602 constantPoolHandle i_cp(THREAD, constants());
3603 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3604 int ioff = iter.inner_class_info_index();
3605 if (ioff != 0) {
3606 // Check to see if the name matches the class we're looking for
3607 // before attempting to find the class.
3608 if (i_cp->klass_name_at_matches(this, ioff)) {
3609 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3610 if (this == inner_klass) {
3611 *ooff = iter.outer_class_info_index();
3612 *noff = iter.inner_name_index();
3613 return true;
3614 }
3615 }
3616 }
3617 }
3618 return false;
3619 }
3620
3621 void InstanceKlass::check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS) {
3622 assert(type->is_instance_klass(), "Sanity check");
3623 if (type->is_identity_class()) {
3624 ResourceMark rm(THREAD);
3625 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3626 err_msg("Class %s expects class %s to be a value class, but it is an identity class",
3627 container_klass_name->as_C_string(),
3628 type->external_name()));
3629 }
3630
3631 if (type->is_abstract()) {
3632 ResourceMark rm(THREAD);
3633 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3634 err_msg("Class %s expects class %s to be concrete value type, but it is an abstract class",
3635 container_klass_name->as_C_string(),
3636 type->external_name()));
3637 }
3638 }
3639
3640 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3641 InstanceKlass* outer_klass = nullptr;
3642 *inner_is_member = false;
3643 int ooff = 0, noff = 0;
3644 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3645 if (has_inner_classes_attr) {
3646 constantPoolHandle i_cp(THREAD, constants());
3647 if (ooff != 0) {
3648 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3649 if (!ok->is_instance_klass()) {
3650 // If the outer class is not an instance klass then it cannot have
3651 // declared any inner classes.
3652 ResourceMark rm(THREAD);
3653 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3654 Exceptions::fthrow(
3655 THREAD_AND_LOCATION,
3656 vmSymbols::java_lang_IncompatibleClassChangeError(),
3657 "%s and %s disagree on InnerClasses attribute",
3658 ok->external_name(),
3659 external_name());
3660 return nullptr;
3661 }
3662 outer_klass = InstanceKlass::cast(ok);
3663 *inner_is_member = true;
3664 }
3665 if (nullptr == outer_klass) {
3666 // It may be a local class; try for that.
3667 int encl_method_class_idx = enclosing_method_class_index();
3668 if (encl_method_class_idx != 0) {
3669 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3670 outer_klass = InstanceKlass::cast(ok);
3671 *inner_is_member = false;
3672 }
3673 }
3674 }
3675
3676 // If no inner class attribute found for this class.
3677 if (nullptr == outer_klass) return nullptr;
3678
3679 // Throws an exception if outer klass has not declared k as an inner klass
3680 // We need evidence that each klass knows about the other, or else
3681 // the system could allow a spoof of an inner class to gain access rights.
3682 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3683 return outer_klass;
3684 }
3685
3686 u2 InstanceKlass::compute_modifier_flags() const {
3687 u2 access = access_flags().as_unsigned_short();
3688
3689 // But check if it happens to be member class.
3690 InnerClassesIterator iter(this);
3691 for (; !iter.done(); iter.next()) {
3692 int ioff = iter.inner_class_info_index();
3693 // Inner class attribute can be zero, skip it.
3694 // Strange but true: JVM spec. allows null inner class refs.
3695 if (ioff == 0) continue;
3696
3697 // only look at classes that are already loaded
3698 // since we are looking for the flags for our self.
3699 Symbol* inner_name = constants()->klass_name_at(ioff);
3700 if (name() == inner_name) {
3701 // This is really a member class.
3702 access = iter.inner_access_flags();
3703 break;
3704 }
3705 }
3706 return access;
3707 }
3708
3709 jint InstanceKlass::jvmti_class_status() const {
3710 jint result = 0;
3711
3712 if (is_linked()) {
3713 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3714 }
3715
3716 if (is_initialized()) {
3717 assert(is_linked(), "Class status is not consistent");
3718 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3719 }
3720 if (is_in_error_state()) {
3721 result |= JVMTI_CLASS_STATUS_ERROR;
3722 }
3723 return result;
3724 }
3725
3726 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3727 bool implements_interface; // initialized by method_at_itable_or_null
3728 Method* m = method_at_itable_or_null(holder, index,
3729 implements_interface); // out parameter
3730 if (m != nullptr) {
3731 assert(implements_interface, "sanity");
3732 return m;
3733 } else if (implements_interface) {
3734 // Throw AbstractMethodError since corresponding itable slot is empty.
3735 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3736 } else {
3737 // If the interface isn't implemented by the receiver class,
3738 // the VM should throw IncompatibleClassChangeError.
3739 ResourceMark rm(THREAD);
3740 stringStream ss;
3741 bool same_module = (module() == holder->module());
3742 ss.print("Receiver class %s does not implement "
3743 "the interface %s defining the method to be called "
3744 "(%s%s%s)",
3745 external_name(), holder->external_name(),
3746 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3747 (same_module) ? "" : "; ",
3748 (same_module) ? "" : holder->class_in_module_of_loader());
3749 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3750 }
3751 }
3752
3753 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3754 klassItable itable(this);
3755 for (int i = 0; i < itable.size_offset_table(); i++) {
3756 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3757 if (offset_entry->interface_klass() == holder) {
3758 implements_interface = true;
3759 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3760 Method* m = ime[index].method();
3761 return m;
3762 }
3763 }
3764 implements_interface = false;
3765 return nullptr; // offset entry not found
3766 }
3767
3768 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3769 assert(is_linked(), "required");
3770 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3771 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3772
3773 int vtable_index = Method::invalid_vtable_index;
3774 Symbol* name = intf_method->name();
3775 Symbol* signature = intf_method->signature();
3776
3777 // First check in default method array
3778 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3779 int index = find_method_index(default_methods(),
3780 name, signature,
3781 Klass::OverpassLookupMode::find,
3782 Klass::StaticLookupMode::find,
3783 Klass::PrivateLookupMode::find);
3784 if (index >= 0) {
3785 vtable_index = default_vtable_indices()->at(index);
3786 }
3787 }
3788 if (vtable_index == Method::invalid_vtable_index) {
3789 // get vtable_index for miranda methods
3790 klassVtable vt = vtable();
3791 vtable_index = vt.index_of_miranda(name, signature);
3792 }
3793 return vtable_index;
3794 }
3795
3796 #if INCLUDE_JVMTI
3797 // update default_methods for redefineclasses for methods that are
3798 // not yet in the vtable due to concurrent subclass define and superinterface
3799 // redefinition
3800 // Note: those in the vtable, should have been updated via adjust_method_entries
3801 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3802 // search the default_methods for uses of either obsolete or EMCP methods
3803 if (default_methods() != nullptr) {
3804 for (int index = 0; index < default_methods()->length(); index ++) {
3805 Method* old_method = default_methods()->at(index);
3806 if (old_method == nullptr || !old_method->is_old()) {
3807 continue; // skip uninteresting entries
3808 }
3809 assert(!old_method->is_deleted(), "default methods may not be deleted");
3810 Method* new_method = old_method->get_new_method();
3811 default_methods()->at_put(index, new_method);
3812
3813 if (log_is_enabled(Info, redefine, class, update)) {
3814 ResourceMark rm;
3815 if (!(*trace_name_printed)) {
3816 log_info(redefine, class, update)
3817 ("adjust: klassname=%s default methods from name=%s",
3818 external_name(), old_method->method_holder()->external_name());
3819 *trace_name_printed = true;
3820 }
3821 log_debug(redefine, class, update, vtables)
3822 ("default method update: %s(%s) ",
3823 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3824 }
3825 }
3826 }
3827 }
3828 #endif // INCLUDE_JVMTI
3829
3830 // On-stack replacement stuff
3831 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3832 assert_lock_strong(NMethodState_lock);
3833 #ifndef PRODUCT
3834 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3835 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3836 "redundant OSR recompilation detected. memory leak in CodeCache!");
3837 #endif
3838 // only one compilation can be active
3839 assert(n->is_osr_method(), "wrong kind of nmethod");
3840 n->set_osr_link(osr_nmethods_head());
3841 set_osr_nmethods_head(n);
3842 // Raise the highest osr level if necessary
3843 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3844
3845 // Get rid of the osr methods for the same bci that have lower levels.
3846 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3847 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3848 if (inv != nullptr && inv->is_in_use()) {
3849 inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3850 }
3851 }
3852 }
3853
3854 // Remove osr nmethod from the list. Return true if found and removed.
3855 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3856 // This is a short non-blocking critical region, so the no safepoint check is ok.
3857 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3858 assert(n->is_osr_method(), "wrong kind of nmethod");
3859 nmethod* last = nullptr;
3860 nmethod* cur = osr_nmethods_head();
3861 int max_level = CompLevel_none; // Find the max comp level excluding n
3862 Method* m = n->method();
3863 // Search for match
3864 bool found = false;
3865 while(cur != nullptr && cur != n) {
3866 if (m == cur->method()) {
3867 // Find max level before n
3868 max_level = MAX2(max_level, cur->comp_level());
3869 }
3870 last = cur;
3871 cur = cur->osr_link();
3872 }
3873 nmethod* next = nullptr;
3874 if (cur == n) {
3875 found = true;
3876 next = cur->osr_link();
3877 if (last == nullptr) {
3878 // Remove first element
3879 set_osr_nmethods_head(next);
3880 } else {
3881 last->set_osr_link(next);
3882 }
3883 }
3884 n->set_osr_link(nullptr);
3885 cur = next;
3886 while (cur != nullptr) {
3887 // Find max level after n
3888 if (m == cur->method()) {
3889 max_level = MAX2(max_level, cur->comp_level());
3890 }
3891 cur = cur->osr_link();
3892 }
3893 m->set_highest_osr_comp_level(max_level);
3894 return found;
3895 }
3896
3897 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3898 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3899 nmethod* osr = osr_nmethods_head();
3900 int found = 0;
3901 while (osr != nullptr) {
3902 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3903 if (osr->method() == m) {
3904 deopt_scope->mark(osr);
3905 found++;
3906 }
3907 osr = osr->osr_link();
3908 }
3909 return found;
3910 }
3911
3912 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3913 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3914 nmethod* osr = osr_nmethods_head();
3915 nmethod* best = nullptr;
3916 while (osr != nullptr) {
3917 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3918 // There can be a time when a c1 osr method exists but we are waiting
3919 // for a c2 version. When c2 completes its osr nmethod we will trash
3920 // the c1 version and only be able to find the c2 version. However
3921 // while we overflow in the c1 code at back branches we don't want to
3922 // try and switch to the same code as we are already running
3923
3924 if (osr->method() == m &&
3925 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3926 if (match_level) {
3927 if (osr->comp_level() == comp_level) {
3928 // Found a match - return it.
3929 return osr;
3930 }
3931 } else {
3932 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3933 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3934 // Found the best possible - return it.
3935 return osr;
3936 }
3937 best = osr;
3938 }
3939 }
3940 }
3941 osr = osr->osr_link();
3942 }
3943
3944 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3945 if (best != nullptr && best->comp_level() >= comp_level) {
3946 return best;
3947 }
3948 return nullptr;
3949 }
3950
3951 // -----------------------------------------------------------------------------------------------------
3952 // Printing
3953
3954 #define BULLET " - "
3955
3956 static const char* state_names[] = {
3957 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3958 };
3959
3960 static void print_vtable(address self, intptr_t* start, int len, outputStream* st) {
3961 ResourceMark rm;
3962 int* forward_refs = NEW_RESOURCE_ARRAY(int, len);
3963 for (int i = 0; i < len; i++) forward_refs[i] = 0;
3964 for (int i = 0; i < len; i++) {
3965 intptr_t e = start[i];
3966 st->print("%d : " INTPTR_FORMAT, i, e);
3967 if (forward_refs[i] != 0) {
3968 int from = forward_refs[i];
3969 int off = (int) start[from];
3970 st->print(" (offset %d <= [%d])", off, from);
3971 }
3972 if (MetaspaceObj::is_valid((Metadata*)e)) {
3973 st->print(" ");
3974 ((Metadata*)e)->print_value_on(st);
3975 } else if (self != nullptr && e > 0 && e < 0x10000) {
3976 address location = self + e;
3977 int index = (int)((intptr_t*)location - start);
3978 st->print(" (offset %d => [%d])", (int)e, index);
3979 if (index >= 0 && index < len)
3980 forward_refs[index] = i;
3981 }
3982 st->cr();
3983 }
3984 }
3985
3986 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3987 return print_vtable(nullptr, reinterpret_cast<intptr_t*>(start), len, st);
3988 }
3989
3990 template<typename T>
3991 static void print_array_on(outputStream* st, Array<T>* array) {
3992 if (array == nullptr) { st->print_cr("nullptr"); return; }
3993 array->print_value_on(st); st->cr();
3994 if (Verbose || WizardMode) {
3995 for (int i = 0; i < array->length(); i++) {
3996 st->print("%d : ", i); array->at(i)->print_value_on(st); st->cr();
3997 }
3998 }
3999 }
4000
4001 static void print_array_on(outputStream* st, Array<int>* array) {
4002 if (array == nullptr) { st->print_cr("nullptr"); return; }
4003 array->print_value_on(st); st->cr();
4004 if (Verbose || WizardMode) {
4005 for (int i = 0; i < array->length(); i++) {
4006 st->print("%d : %d", i, array->at(i)); st->cr();
4007 }
4008 }
4009 }
4010
4011 const char* InstanceKlass::init_state_name() const {
4012 return state_names[init_state()];
4013 }
4014
4015 void InstanceKlass::print_on(outputStream* st) const {
4016 assert(is_klass(), "must be klass");
4017 Klass::print_on(st);
4018
4019 st->print(BULLET"instance size: %d", size_helper()); st->cr();
4020 st->print(BULLET"klass size: %d", size()); st->cr();
4021 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
4022 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
4023 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
4024 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
4025 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
4026 st->print(BULLET"sub: ");
4027 Klass* sub = subklass();
4028 int n;
4029 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
4030 if (n < MaxSubklassPrintSize) {
4031 sub->print_value_on(st);
4032 st->print(" ");
4033 }
4034 }
4035 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
4036 st->cr();
4037
4038 if (is_interface()) {
4039 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
4040 if (nof_implementors() == 1) {
4041 st->print_cr(BULLET"implementor: ");
4042 st->print(" ");
4043 implementor()->print_value_on(st);
4044 st->cr();
4045 }
4046 }
4047
4048 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
4049 st->print(BULLET"methods: "); print_array_on(st, methods());
4050 st->print(BULLET"method ordering: "); print_array_on(st, method_ordering());
4051 if (default_methods() != nullptr) {
4052 st->print(BULLET"default_methods: "); print_array_on(st, default_methods());
4053 }
4054 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
4055 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
4056 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
4057
4058 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
4059
4060 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
4061 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
4062
4063 if (secondary_supers() != nullptr) {
4064 if (Verbose) {
4065 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
4066 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
4067 for (int i = 0; i < _secondary_supers->length(); i++) {
4068 ResourceMark rm; // for external_name()
4069 Klass* secondary_super = _secondary_supers->at(i);
4070 st->print(BULLET"%2d:", i);
4071 if (is_hashed) {
4072 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
4073 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
4074 st->print(" dist:%02d:", distance);
4075 }
4076 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
4077 }
4078 }
4079 }
4080 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
4081
4082 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
4083 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
4084 if (source_debug_extension() != nullptr) {
4085 st->print(BULLET"source debug extension: ");
4086 st->print("%s", source_debug_extension());
4087 st->cr();
4088 }
4089 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
4090 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
4091 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
4092 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
4093 {
4094 bool have_pv = false;
4095 // previous versions are linked together through the InstanceKlass
4096 for (InstanceKlass* pv_node = previous_versions();
4097 pv_node != nullptr;
4098 pv_node = pv_node->previous_versions()) {
4099 if (!have_pv)
4100 st->print(BULLET"previous version: ");
4101 have_pv = true;
4102 pv_node->constants()->print_value_on(st);
4103 }
4104 if (have_pv) st->cr();
4105 }
4106
4107 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
4108 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
4109 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
4110 print_on_maybe_null(st, BULLET"record components: ", record_components());
4111 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
4112 st->print(BULLET"loadable descriptors: "); loadable_descriptors()->print_value_on(st); st->cr();
4113 if (java_mirror() != nullptr) {
4114 st->print(BULLET"java mirror: ");
4115 java_mirror()->print_value_on(st);
4116 st->cr();
4117 } else {
4118 st->print_cr(BULLET"java mirror: null");
4119 }
4120 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
4121 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
4122 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
4123 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(nullptr, start_of_itable(), itable_length(), st);
4124 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
4125
4126 FieldPrinter print_static_field(st);
4127 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
4128 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
4129 FieldPrinter print_nonstatic_field(st);
4130 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
4131 ik->print_nonstatic_fields(&print_nonstatic_field);
4132
4133 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
4134 OopMapBlock* map = start_of_nonstatic_oop_maps();
4135 OopMapBlock* end_map = map + nonstatic_oop_map_count();
4136 while (map < end_map) {
4137 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
4138 map++;
4139 }
4140 st->cr();
4141
4142 if (fieldinfo_search_table() != nullptr) {
4143 st->print_cr(BULLET"---- field info search table:");
4144 FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
4145 }
4146 }
4147
4148 void InstanceKlass::print_value_on(outputStream* st) const {
4149 assert(is_klass(), "must be klass");
4150 if (Verbose || WizardMode) access_flags().print_on(st);
4151 name()->print_value_on(st);
4152 }
4153
4154 void FieldPrinter::do_field(fieldDescriptor* fd) {
4155 for (int i = 0; i < _indent; i++) _st->print(" ");
4156 _st->print(BULLET);
4157 if (_obj == nullptr) {
4158 fd->print_on(_st, _base_offset);
4159 _st->cr();
4160 } else {
4161 fd->print_on_for(_st, _obj, _indent, _base_offset);
4162 if (!fd->field_flags().is_flat()) _st->cr();
4163 }
4164 }
4165
4166
4167 void InstanceKlass::oop_print_on(oop obj, outputStream* st, int indent, int base_offset) {
4168 Klass::oop_print_on(obj, st);
4169
4170 if (this == vmClasses::String_klass()) {
4171 typeArrayOop value = java_lang_String::value(obj);
4172 juint length = java_lang_String::length(obj);
4173 if (value != nullptr &&
4174 value->is_typeArray() &&
4175 length <= (juint) value->length()) {
4176 st->print(BULLET"string: ");
4177 java_lang_String::print(obj, st);
4178 st->cr();
4179 }
4180 }
4181
4182 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
4183 FieldPrinter print_field(st, obj, indent, base_offset);
4184 print_nonstatic_fields(&print_field);
4185
4186 if (this == vmClasses::Class_klass()) {
4187 st->print(BULLET"signature: ");
4188 java_lang_Class::print_signature(obj, st);
4189 st->cr();
4190 Klass* real_klass = java_lang_Class::as_Klass(obj);
4191 if (real_klass != nullptr && real_klass->is_instance_klass()) {
4192 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
4193 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
4194 }
4195 } else if (this == vmClasses::MethodType_klass()) {
4196 st->print(BULLET"signature: ");
4197 java_lang_invoke_MethodType::print_signature(obj, st);
4198 st->cr();
4199 }
4200 }
4201
4202 #ifndef PRODUCT
4203
4204 bool InstanceKlass::verify_itable_index(int i) {
4205 int method_count = klassItable::method_count_for_interface(this);
4206 assert(i >= 0 && i < method_count, "index out of bounds");
4207 return true;
4208 }
4209
4210 #endif //PRODUCT
4211
4212 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
4213 st->print("a ");
4214 name()->print_value_on(st);
4215 obj->print_address_on(st);
4216 if (this == vmClasses::String_klass()
4217 && java_lang_String::value(obj) != nullptr) {
4218 ResourceMark rm;
4219 int len = java_lang_String::length(obj);
4220 int plen = (len < 24 ? len : 12);
4221 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
4222 st->print(" = \"%s\"", str);
4223 if (len > plen)
4224 st->print("...[%d]", len);
4225 } else if (this == vmClasses::Class_klass()) {
4226 Klass* k = java_lang_Class::as_Klass(obj);
4227 st->print(" = ");
4228 if (k != nullptr) {
4229 k->print_value_on(st);
4230 } else {
4231 const char* tname = type2name(java_lang_Class::primitive_type(obj));
4232 st->print("%s", tname ? tname : "type?");
4233 }
4234 } else if (this == vmClasses::MethodType_klass()) {
4235 st->print(" = ");
4236 java_lang_invoke_MethodType::print_signature(obj, st);
4237 } else if (java_lang_boxing_object::is_instance(obj)) {
4238 st->print(" = ");
4239 java_lang_boxing_object::print(obj, st);
4240 } else if (this == vmClasses::LambdaForm_klass()) {
4241 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
4242 if (vmentry != nullptr) {
4243 st->print(" => ");
4244 vmentry->print_value_on(st);
4245 }
4246 } else if (this == vmClasses::MemberName_klass()) {
4247 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
4248 if (vmtarget != nullptr) {
4249 st->print(" = ");
4250 vmtarget->print_value_on(st);
4251 } else {
4252 oop clazz = java_lang_invoke_MemberName::clazz(obj);
4253 oop name = java_lang_invoke_MemberName::name(obj);
4254 if (clazz != nullptr) {
4255 clazz->print_value_on(st);
4256 } else {
4257 st->print("null");
4258 }
4259 st->print(".");
4260 if (name != nullptr) {
4261 name->print_value_on(st);
4262 } else {
4263 st->print("null");
4264 }
4265 }
4266 }
4267 }
4268
4269 const char* InstanceKlass::internal_name() const {
4270 return external_name();
4271 }
4272
4273 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
4274 const ModuleEntry* module_entry,
4275 const ClassFileStream* cfs) const {
4276
4277 if (ClassListWriter::is_enabled()) {
4278 ClassListWriter::write(this, cfs);
4279 }
4280
4281 print_class_load_helper(loader_data, module_entry, cfs);
4282 print_class_load_cause_logging();
4283 }
4284
4285 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
4286 const ModuleEntry* module_entry,
4287 const ClassFileStream* cfs) const {
4288
4289 if (!log_is_enabled(Info, class, load)) {
4290 return;
4291 }
4292
4293 ResourceMark rm;
4294 LogMessage(class, load) msg;
4295 stringStream info_stream;
4296
4297 // Name and class hierarchy info
4298 info_stream.print("%s", external_name());
4299
4300 // Source
4301 if (cfs != nullptr) {
4302 if (cfs->source() != nullptr) {
4303 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
4304 if (module_name != nullptr) {
4305 // When the boot loader created the stream, it didn't know the module name
4306 // yet. Let's format it now.
4307 if (cfs->from_boot_loader_modules_image()) {
4308 info_stream.print(" source: jrt:/%s", module_name);
4309 } else {
4310 info_stream.print(" source: %s", cfs->source());
4311 }
4312 } else {
4313 info_stream.print(" source: %s", cfs->source());
4314 }
4315 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
4316 Thread* current = Thread::current();
4317 Klass* caller = current->is_Java_thread() ?
4318 JavaThread::cast(current)->security_get_caller_class(1):
4319 nullptr;
4320 // caller can be null, for example, during a JVMTI VM_Init hook
4321 if (caller != nullptr) {
4322 info_stream.print(" source: instance of %s", caller->external_name());
4323 } else {
4324 // source is unknown
4325 }
4326 } else {
4327 oop class_loader = loader_data->class_loader();
4328 info_stream.print(" source: %s", class_loader->klass()->external_name());
4329 }
4330 } else {
4331 assert(this->is_shared(), "must be");
4332 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
4333 info_stream.print(" source: shared objects file (top)");
4334 } else {
4335 info_stream.print(" source: shared objects file");
4336 }
4337 }
4338
4339 msg.info("%s", info_stream.as_string());
4340
4341 if (log_is_enabled(Debug, class, load)) {
4342 stringStream debug_stream;
4343
4344 // Class hierarchy info
4345 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4346 p2i(this), p2i(superklass()));
4347
4348 // Interfaces
4349 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4350 debug_stream.print(" interfaces:");
4351 int length = local_interfaces()->length();
4352 for (int i = 0; i < length; i++) {
4353 debug_stream.print(" " PTR_FORMAT,
4354 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
4355 }
4356 }
4357
4358 // Class loader
4359 debug_stream.print(" loader: [");
4360 loader_data->print_value_on(&debug_stream);
4361 debug_stream.print("]");
4362
4363 // Classfile checksum
4364 if (cfs) {
4365 debug_stream.print(" bytes: %d checksum: %08x",
4366 cfs->length(),
4367 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4368 cfs->length()));
4369 }
4370
4371 msg.debug("%s", debug_stream.as_string());
4372 }
4373 }
4374
4375 void InstanceKlass::print_class_load_cause_logging() const {
4376 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4377 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4378 JavaThread* current = JavaThread::current();
4379 ResourceMark rm(current);
4380 const char* name = external_name();
4381
4382 if (LogClassLoadingCauseFor == nullptr ||
4383 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4384 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4385 return;
4386 }
4387
4388 // Log Java stack first
4389 {
4390 LogMessage(class, load, cause) msg;
4391 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4392
4393 info_stream.print_cr("Java stack when loading %s:", name);
4394 current->print_stack_on(&info_stream);
4395 }
4396
4397 // Log native stack second
4398 if (log_cause_native) {
4399 // Log to string first so that lines can be indented
4400 stringStream stack_stream;
4401 char buf[O_BUFLEN];
4402 address lastpc = nullptr;
4403 NativeStackPrinter nsp(current);
4404 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4405 true /* print_source_info */, -1 /* max stack */);
4406
4407 LogMessage(class, load, cause, native) msg;
4408 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4409 info_stream.print_cr("Native stack when loading %s:", name);
4410
4411 // Print each native stack line to the log
4412 int size = (int) stack_stream.size();
4413 char* stack = stack_stream.as_string();
4414 char* stack_end = stack + size;
4415 char* line_start = stack;
4416 for (char* p = stack; p < stack_end; p++) {
4417 if (*p == '\n') {
4418 *p = '\0';
4419 info_stream.print_cr("\t%s", line_start);
4420 line_start = p + 1;
4421 }
4422 }
4423 if (line_start < stack_end) {
4424 info_stream.print_cr("\t%s", line_start);
4425 }
4426 }
4427 }
4428 }
4429
4430 // Verification
4431
4432 class VerifyFieldClosure: public BasicOopIterateClosure {
4433 protected:
4434 template <class T> void do_oop_work(T* p) {
4435 oop obj = RawAccess<>::oop_load(p);
4436 if (!oopDesc::is_oop_or_null(obj)) {
4437 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4438 Universe::print_on(tty);
4439 guarantee(false, "boom");
4440 }
4441 }
4442 public:
4443 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4444 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4445 };
4446
4447 void InstanceKlass::verify_on(outputStream* st) {
4448 #ifndef PRODUCT
4449 // Avoid redundant verifies, this really should be in product.
4450 if (_verify_count == Universe::verify_count()) return;
4451 _verify_count = Universe::verify_count();
4452 #endif
4453
4454 // Verify Klass
4455 Klass::verify_on(st);
4456
4457 // Verify that klass is present in ClassLoaderData
4458 guarantee(class_loader_data()->contains_klass(this),
4459 "this class isn't found in class loader data");
4460
4461 // Verify vtables
4462 if (is_linked()) {
4463 // $$$ This used to be done only for m/s collections. Doing it
4464 // always seemed a valid generalization. (DLD -- 6/00)
4465 vtable().verify(st);
4466 }
4467
4468 // Verify first subklass
4469 if (subklass() != nullptr) {
4470 guarantee(subklass()->is_klass(), "should be klass");
4471 }
4472
4473 // Verify siblings
4474 Klass* super = this->super();
4475 Klass* sib = next_sibling();
4476 if (sib != nullptr) {
4477 if (sib == this) {
4478 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4479 }
4480
4481 guarantee(sib->is_klass(), "should be klass");
4482 guarantee(sib->super() == super, "siblings should have same superklass");
4483 }
4484
4485 // Verify local interfaces
4486 if (local_interfaces()) {
4487 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4488 for (int j = 0; j < local_interfaces->length(); j++) {
4489 InstanceKlass* e = local_interfaces->at(j);
4490 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4491 }
4492 }
4493
4494 // Verify transitive interfaces
4495 if (transitive_interfaces() != nullptr) {
4496 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4497 for (int j = 0; j < transitive_interfaces->length(); j++) {
4498 InstanceKlass* e = transitive_interfaces->at(j);
4499 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4500 }
4501 }
4502
4503 // Verify methods
4504 if (methods() != nullptr) {
4505 Array<Method*>* methods = this->methods();
4506 for (int j = 0; j < methods->length(); j++) {
4507 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4508 }
4509 for (int j = 0; j < methods->length() - 1; j++) {
4510 Method* m1 = methods->at(j);
4511 Method* m2 = methods->at(j + 1);
4512 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4513 }
4514 }
4515
4516 // Verify method ordering
4517 if (method_ordering() != nullptr) {
4518 Array<int>* method_ordering = this->method_ordering();
4519 int length = method_ordering->length();
4520 if (JvmtiExport::can_maintain_original_method_order() ||
4521 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4522 guarantee(length == methods()->length(), "invalid method ordering length");
4523 jlong sum = 0;
4524 for (int j = 0; j < length; j++) {
4525 int original_index = method_ordering->at(j);
4526 guarantee(original_index >= 0, "invalid method ordering index");
4527 guarantee(original_index < length, "invalid method ordering index");
4528 sum += original_index;
4529 }
4530 // Verify sum of indices 0,1,...,length-1
4531 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4532 } else {
4533 guarantee(length == 0, "invalid method ordering length");
4534 }
4535 }
4536
4537 // Verify default methods
4538 if (default_methods() != nullptr) {
4539 Array<Method*>* methods = this->default_methods();
4540 for (int j = 0; j < methods->length(); j++) {
4541 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4542 }
4543 for (int j = 0; j < methods->length() - 1; j++) {
4544 Method* m1 = methods->at(j);
4545 Method* m2 = methods->at(j + 1);
4546 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4547 }
4548 }
4549
4550 // Verify JNI static field identifiers
4551 if (jni_ids() != nullptr) {
4552 jni_ids()->verify(this);
4553 }
4554
4555 // Verify other fields
4556 if (constants() != nullptr) {
4557 guarantee(constants()->is_constantPool(), "should be constant pool");
4558 }
4559 }
4560
4561 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4562 Klass::oop_verify_on(obj, st);
4563 VerifyFieldClosure blk;
4564 obj->oop_iterate(&blk);
4565 }
4566
4567
4568 // JNIid class for jfieldIDs only
4569 // Note to reviewers:
4570 // These JNI functions are just moved over to column 1 and not changed
4571 // in the compressed oops workspace.
4572 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4573 _holder = holder;
4574 _offset = offset;
4575 _next = next;
4576 DEBUG_ONLY(_is_static_field_id = false;)
4577 }
4578
4579
4580 JNIid* JNIid::find(int offset) {
4581 JNIid* current = this;
4582 while (current != nullptr) {
4583 if (current->offset() == offset) return current;
4584 current = current->next();
4585 }
4586 return nullptr;
4587 }
4588
4589 void JNIid::deallocate(JNIid* current) {
4590 while (current != nullptr) {
4591 JNIid* next = current->next();
4592 delete current;
4593 current = next;
4594 }
4595 }
4596
4597
4598 void JNIid::verify(Klass* holder) {
4599 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4600 int end_field_offset;
4601 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4602
4603 JNIid* current = this;
4604 while (current != nullptr) {
4605 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4606 #ifdef ASSERT
4607 int o = current->offset();
4608 if (current->is_static_field_id()) {
4609 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4610 }
4611 #endif
4612 current = current->next();
4613 }
4614 }
4615
4616 void InstanceKlass::set_init_state(ClassState state) {
4617 #ifdef ASSERT
4618 bool good_state = is_shared() ? (_init_state <= state)
4619 : (_init_state < state);
4620 assert(good_state || state == allocated, "illegal state transition");
4621 #endif
4622 assert(_init_thread == nullptr, "should be cleared before state change");
4623 Atomic::release_store(&_init_state, state);
4624 }
4625
4626 #if INCLUDE_JVMTI
4627
4628 // RedefineClasses() support for previous versions
4629
4630 // Globally, there is at least one previous version of a class to walk
4631 // during class unloading, which is saved because old methods in the class
4632 // are still running. Otherwise the previous version list is cleaned up.
4633 bool InstanceKlass::_should_clean_previous_versions = false;
4634
4635 // Returns true if there are previous versions of a class for class
4636 // unloading only. Also resets the flag to false. purge_previous_version
4637 // will set the flag to true if there are any left, i.e., if there's any
4638 // work to do for next time. This is to avoid the expensive code cache
4639 // walk in CLDG::clean_deallocate_lists().
4640 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4641 bool ret = _should_clean_previous_versions;
4642 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4643 ret ? "true" : "false");
4644 _should_clean_previous_versions = false;
4645 return ret;
4646 }
4647
4648 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4649 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4650 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4651 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4652 Array<Method*>* method_refs = klass->methods();
4653 for (int k = 0; k < method_refs->length(); k++) {
4654 Method* method = method_refs->at(k);
4655 // Only need to clear obsolete methods.
4656 if (method != nullptr && method->is_obsolete()) {
4657 method->clear_jmethod_id();
4658 }
4659 }
4660 }
4661
4662 // Purge previous versions before adding new previous versions of the class and
4663 // during class unloading.
4664 void InstanceKlass::purge_previous_version_list() {
4665 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4666 assert(has_been_redefined(), "Should only be called for main class");
4667
4668 // Quick exit.
4669 if (previous_versions() == nullptr) {
4670 return;
4671 }
4672
4673 // This klass has previous versions so see what we can cleanup
4674 // while it is safe to do so.
4675
4676 int deleted_count = 0; // leave debugging breadcrumbs
4677 int live_count = 0;
4678 ClassLoaderData* loader_data = class_loader_data();
4679 assert(loader_data != nullptr, "should never be null");
4680
4681 ResourceMark rm;
4682 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4683
4684 // previous versions are linked together through the InstanceKlass
4685 InstanceKlass* pv_node = previous_versions();
4686 InstanceKlass* last = this;
4687 int version = 0;
4688
4689 // check the previous versions list
4690 for (; pv_node != nullptr; ) {
4691
4692 ConstantPool* pvcp = pv_node->constants();
4693 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4694
4695 if (!pvcp->on_stack()) {
4696 // If the constant pool isn't on stack, none of the methods
4697 // are executing. Unlink this previous_version.
4698 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4699 // so will be deallocated during the next phase of class unloading.
4700 log_trace(redefine, class, iklass, purge)
4701 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4702 // Unlink from previous version list.
4703 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4704 InstanceKlass* next = pv_node->previous_versions();
4705 clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4706 pv_node->link_previous_versions(nullptr); // point next to null
4707 last->link_previous_versions(next);
4708 // Delete this node directly. Nothing is referring to it and we don't
4709 // want it to increase the counter for metadata to delete in CLDG.
4710 MetadataFactory::free_metadata(loader_data, pv_node);
4711 pv_node = next;
4712 deleted_count++;
4713 version++;
4714 continue;
4715 } else {
4716 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4717 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4718 live_count++;
4719 if (pvcp->is_shared()) {
4720 // Shared previous versions can never be removed so no cleaning is needed.
4721 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4722 } else {
4723 // Previous version alive, set that clean is needed for next time.
4724 _should_clean_previous_versions = true;
4725 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4726 }
4727 }
4728
4729 // next previous version
4730 last = pv_node;
4731 pv_node = pv_node->previous_versions();
4732 version++;
4733 }
4734 log_trace(redefine, class, iklass, purge)
4735 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4736 }
4737
4738 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4739 int emcp_method_count) {
4740 int obsolete_method_count = old_methods->length() - emcp_method_count;
4741
4742 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4743 _previous_versions != nullptr) {
4744 // We have a mix of obsolete and EMCP methods so we have to
4745 // clear out any matching EMCP method entries the hard way.
4746 int local_count = 0;
4747 for (int i = 0; i < old_methods->length(); i++) {
4748 Method* old_method = old_methods->at(i);
4749 if (old_method->is_obsolete()) {
4750 // only obsolete methods are interesting
4751 Symbol* m_name = old_method->name();
4752 Symbol* m_signature = old_method->signature();
4753
4754 // previous versions are linked together through the InstanceKlass
4755 int j = 0;
4756 for (InstanceKlass* prev_version = _previous_versions;
4757 prev_version != nullptr;
4758 prev_version = prev_version->previous_versions(), j++) {
4759
4760 Array<Method*>* method_refs = prev_version->methods();
4761 for (int k = 0; k < method_refs->length(); k++) {
4762 Method* method = method_refs->at(k);
4763
4764 if (!method->is_obsolete() &&
4765 method->name() == m_name &&
4766 method->signature() == m_signature) {
4767 // The current RedefineClasses() call has made all EMCP
4768 // versions of this method obsolete so mark it as obsolete
4769 log_trace(redefine, class, iklass, add)
4770 ("%s(%s): flush obsolete method @%d in version @%d",
4771 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4772
4773 method->set_is_obsolete();
4774 break;
4775 }
4776 }
4777
4778 // The previous loop may not find a matching EMCP method, but
4779 // that doesn't mean that we can optimize and not go any
4780 // further back in the PreviousVersion generations. The EMCP
4781 // method for this generation could have already been made obsolete,
4782 // but there still may be an older EMCP method that has not
4783 // been made obsolete.
4784 }
4785
4786 if (++local_count >= obsolete_method_count) {
4787 // no more obsolete methods so bail out now
4788 break;
4789 }
4790 }
4791 }
4792 }
4793 }
4794
4795 // Save the scratch_class as the previous version if any of the methods are running.
4796 // The previous_versions are used to set breakpoints in EMCP methods and they are
4797 // also used to clean MethodData links to redefined methods that are no longer running.
4798 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4799 int emcp_method_count) {
4800 assert(Thread::current()->is_VM_thread(),
4801 "only VMThread can add previous versions");
4802
4803 ResourceMark rm;
4804 log_trace(redefine, class, iklass, add)
4805 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4806
4807 // Clean out old previous versions for this class
4808 purge_previous_version_list();
4809
4810 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4811 // a previous redefinition may be made obsolete by this redefinition.
4812 Array<Method*>* old_methods = scratch_class->methods();
4813 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4814
4815 // If the constant pool for this previous version of the class
4816 // is not marked as being on the stack, then none of the methods
4817 // in this previous version of the class are on the stack so
4818 // we don't need to add this as a previous version.
4819 ConstantPool* cp_ref = scratch_class->constants();
4820 if (!cp_ref->on_stack()) {
4821 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4822 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4823 return;
4824 }
4825
4826 // Add previous version if any methods are still running or if this is
4827 // a shared class which should never be removed.
4828 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4829 scratch_class->link_previous_versions(previous_versions());
4830 link_previous_versions(scratch_class);
4831 if (cp_ref->is_shared()) {
4832 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4833 } else {
4834 // We only set clean_previous_versions flag for processing during class
4835 // unloading for non-shared classes.
4836 _should_clean_previous_versions = true;
4837 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4838 }
4839 } // end add_previous_version()
4840
4841 #endif // INCLUDE_JVMTI
4842
4843 Method* InstanceKlass::method_with_idnum(int idnum) const {
4844 Method* m = nullptr;
4845 if (idnum < methods()->length()) {
4846 m = methods()->at(idnum);
4847 }
4848 if (m == nullptr || m->method_idnum() != idnum) {
4849 for (int index = 0; index < methods()->length(); ++index) {
4850 m = methods()->at(index);
4851 if (m->method_idnum() == idnum) {
4852 return m;
4853 }
4854 }
4855 // None found, return null for the caller to handle.
4856 return nullptr;
4857 }
4858 return m;
4859 }
4860
4861
4862 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4863 if (idnum >= methods()->length()) {
4864 return nullptr;
4865 }
4866 Method* m = methods()->at(idnum);
4867 if (m != nullptr && m->orig_method_idnum() == idnum) {
4868 return m;
4869 }
4870 // Obsolete method idnum does not match the original idnum
4871 for (int index = 0; index < methods()->length(); ++index) {
4872 m = methods()->at(index);
4873 if (m->orig_method_idnum() == idnum) {
4874 return m;
4875 }
4876 }
4877 // None found, return null for the caller to handle.
4878 return nullptr;
4879 }
4880
4881
4882 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4883 const InstanceKlass* holder = get_klass_version(version);
4884 if (holder == nullptr) {
4885 return nullptr; // The version of klass is gone, no method is found
4886 }
4887 return holder->method_with_orig_idnum(idnum);
4888 }
4889
4890 #if INCLUDE_JVMTI
4891 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4892 return _cached_class_file;
4893 }
4894
4895 jint InstanceKlass::get_cached_class_file_len() {
4896 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4897 }
4898
4899 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4900 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4901 }
4902 #endif
4903
4904 // Make a step iterating over the class hierarchy under the root class.
4905 // Skips subclasses if requested.
4906 void ClassHierarchyIterator::next() {
4907 assert(_current != nullptr, "required");
4908 if (_visit_subclasses && _current->subklass() != nullptr) {
4909 _current = _current->subklass();
4910 return; // visit next subclass
4911 }
4912 _visit_subclasses = true; // reset
4913 while (_current->next_sibling() == nullptr && _current != _root) {
4914 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4915 }
4916 if (_current == _root) {
4917 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4918 _current = nullptr;
4919 return;
4920 }
4921 _current = _current->next_sibling();
4922 return; // visit next sibling subclass
4923 }