1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "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 "logging/logMessage.hpp"
55 #include "logging/logStream.hpp"
56 #include "memory/allocation.inline.hpp"
57 #include "memory/iterator.inline.hpp"
58 #include "memory/metadataFactory.hpp"
59 #include "memory/metaspaceClosure.hpp"
60 #include "memory/oopFactory.hpp"
61 #include "memory/resourceArea.hpp"
62 #include "memory/universe.hpp"
63 #include "oops/fieldStreams.inline.hpp"
64 #include "oops/constantPool.hpp"
65 #include "oops/instanceClassLoaderKlass.hpp"
66 #include "oops/instanceKlass.inline.hpp"
67 #include "oops/instanceMirrorKlass.hpp"
68 #include "oops/instanceOop.hpp"
69 #include "oops/instanceStackChunkKlass.hpp"
70 #include "oops/klass.inline.hpp"
71 #include "oops/method.hpp"
72 #include "oops/oop.inline.hpp"
73 #include "oops/recordComponent.hpp"
74 #include "oops/symbol.hpp"
75 #include "prims/jvmtiExport.hpp"
76 #include "prims/jvmtiRedefineClasses.hpp"
77 #include "prims/jvmtiThreadState.hpp"
78 #include "prims/methodComparator.hpp"
79 #include "runtime/arguments.hpp"
80 #include "runtime/deoptimization.hpp"
81 #include "runtime/atomic.hpp"
82 #include "runtime/fieldDescriptor.inline.hpp"
83 #include "runtime/handles.inline.hpp"
84 #include "runtime/javaCalls.hpp"
85 #include "runtime/javaThread.inline.hpp"
86 #include "runtime/mutexLocker.hpp"
87 #include "runtime/orderAccess.hpp"
88 #include "runtime/os.inline.hpp"
89 #include "runtime/reflection.hpp"
90 #include "runtime/synchronizer.hpp"
91 #include "runtime/threads.hpp"
92 #include "services/classLoadingService.hpp"
93 #include "services/finalizerService.hpp"
94 #include "services/threadService.hpp"
95 #include "utilities/dtrace.hpp"
96 #include "utilities/events.hpp"
97 #include "utilities/macros.hpp"
98 #include "utilities/stringUtils.hpp"
99 #include "utilities/pair.hpp"
100 #ifdef COMPILER1
101 #include "c1/c1_Compiler.hpp"
102 #endif
103 #if INCLUDE_JFR
104 #include "jfr/jfrEvents.hpp"
105 #endif
106
107 #ifdef DTRACE_ENABLED
108
109
110 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
111 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
112 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
113 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
114 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
115 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
116 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
117 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
118 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
119 { \
120 char* data = nullptr; \
121 int len = 0; \
122 Symbol* clss_name = name(); \
123 if (clss_name != nullptr) { \
124 data = (char*)clss_name->bytes(); \
125 len = clss_name->utf8_length(); \
126 } \
127 HOTSPOT_CLASS_INITIALIZATION_##type( \
128 data, len, (void*)class_loader(), thread_type); \
129 }
130
131 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
132 { \
133 char* data = nullptr; \
134 int len = 0; \
135 Symbol* clss_name = name(); \
136 if (clss_name != nullptr) { \
137 data = (char*)clss_name->bytes(); \
138 len = clss_name->utf8_length(); \
139 } \
140 HOTSPOT_CLASS_INITIALIZATION_##type( \
141 data, len, (void*)class_loader(), thread_type, wait); \
142 }
143
144 #else // ndef DTRACE_ENABLED
145
146 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
147 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
148
149 #endif // ndef DTRACE_ENABLED
150
151 bool InstanceKlass::_finalization_enabled = true;
152
153 static inline bool is_class_loader(const Symbol* class_name,
154 const ClassFileParser& parser) {
155 assert(class_name != nullptr, "invariant");
156
157 if (class_name == vmSymbols::java_lang_ClassLoader()) {
158 return true;
159 }
160
161 if (vmClasses::ClassLoader_klass_loaded()) {
162 const Klass* const super_klass = parser.super_klass();
163 if (super_klass != nullptr) {
164 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
165 return true;
166 }
167 }
168 }
169 return false;
170 }
171
172 static inline bool is_stack_chunk_class(const Symbol* class_name,
173 const ClassLoaderData* loader_data) {
174 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
175 loader_data->is_the_null_class_loader_data());
176 }
177
178 // private: called to verify that k is a static member of this nest.
179 // We know that k is an instance class in the same package and hence the
180 // same classloader.
181 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
182 assert(!is_hidden(), "unexpected hidden class");
183 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
184 if (log_is_enabled(Trace, class, nestmates)) {
185 ResourceMark rm(current);
186 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
187 k->external_name(), this->external_name());
188 }
189 return false;
190 }
191
192 if (log_is_enabled(Trace, class, nestmates)) {
193 ResourceMark rm(current);
194 log_trace(class, nestmates)("Checking nest membership of %s in %s",
195 k->external_name(), this->external_name());
196 }
197
198 // Check for the named class in _nest_members.
199 // We don't resolve, or load, any classes.
200 for (int i = 0; i < _nest_members->length(); i++) {
201 int cp_index = _nest_members->at(i);
202 Symbol* name = _constants->klass_name_at(cp_index);
203 if (name == k->name()) {
204 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
205 return true;
206 }
207 }
208 log_trace(class, nestmates)("- class is NOT a nest member!");
209 return false;
210 }
211
212 // Called to verify that k is a permitted subclass of this class
213 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k) const {
214 Thread* current = Thread::current();
215 assert(k != nullptr, "sanity check");
216 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
217 "unexpected empty _permitted_subclasses array");
218
219 if (log_is_enabled(Trace, class, sealed)) {
220 ResourceMark rm(current);
221 log_trace(class, sealed)("Checking for permitted subclass of %s in %s",
222 k->external_name(), this->external_name());
223 }
224
225 // Check that the class and its super are in the same module.
226 if (k->module() != this->module()) {
227 ResourceMark rm(current);
228 log_trace(class, sealed)("Check failed for same module of permitted subclass %s and sealed class %s",
229 k->external_name(), this->external_name());
230 return false;
231 }
232
233 if (!k->is_public() && !is_same_class_package(k)) {
234 ResourceMark rm(current);
235 log_trace(class, sealed)("Check failed, subclass %s not public and not in the same package as sealed class %s",
236 k->external_name(), this->external_name());
237 return false;
238 }
239
240 for (int i = 0; i < _permitted_subclasses->length(); i++) {
241 int cp_index = _permitted_subclasses->at(i);
242 Symbol* name = _constants->klass_name_at(cp_index);
243 if (name == k->name()) {
244 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
245 return true;
246 }
247 }
248 log_trace(class, sealed)("- class is NOT a permitted subclass!");
249 return false;
250 }
251
252 // Return nest-host class, resolving, validating and saving it if needed.
253 // In cases where this is called from a thread that cannot do classloading
254 // (such as a native JIT thread) then we simply return null, which in turn
255 // causes the access check to return false. Such code will retry the access
256 // from a more suitable environment later. Otherwise the _nest_host is always
257 // set once this method returns.
258 // Any errors from nest-host resolution must be preserved so they can be queried
259 // from higher-level access checking code, and reported as part of access checking
260 // exceptions.
261 // VirtualMachineErrors are propagated with a null return.
262 // Under any conditions where the _nest_host can be set to non-null the resulting
263 // value of it and, if applicable, the nest host resolution/validation error,
264 // are idempotent.
265 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
266 InstanceKlass* nest_host_k = _nest_host;
267 if (nest_host_k != nullptr) {
268 return nest_host_k;
269 }
270
271 ResourceMark rm(THREAD);
272
273 // need to resolve and save our nest-host class.
274 if (_nest_host_index != 0) { // we have a real nest_host
275 // Before trying to resolve check if we're in a suitable context
276 bool can_resolve = THREAD->can_call_java();
277 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
278 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
279 this->external_name());
280 return nullptr; // sentinel to say "try again from a different context"
281 }
282
283 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
284 this->external_name(),
285 _constants->klass_name_at(_nest_host_index)->as_C_string());
286
287 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
288 if (HAS_PENDING_EXCEPTION) {
289 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
290 return nullptr; // propagate VMEs
291 }
292 stringStream ss;
293 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
294 ss.print("Nest host resolution of %s with host %s failed: ",
295 this->external_name(), target_host_class);
296 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
297 const char* msg = ss.as_string(true /* on C-heap */);
298 constantPoolHandle cph(THREAD, constants());
299 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
300 CLEAR_PENDING_EXCEPTION;
301
302 log_trace(class, nestmates)("%s", msg);
303 } else {
304 // A valid nest-host is an instance class in the current package that lists this
305 // class as a nest member. If any of these conditions are not met the class is
306 // its own nest-host.
307 const char* error = nullptr;
308
309 // JVMS 5.4.4 indicates package check comes first
310 if (is_same_class_package(k)) {
311 // Now check actual membership. We can't be a member if our "host" is
312 // not an instance class.
313 if (k->is_instance_klass()) {
314 nest_host_k = InstanceKlass::cast(k);
315 bool is_member = nest_host_k->has_nest_member(THREAD, this);
316 if (is_member) {
317 _nest_host = nest_host_k; // save resolved nest-host value
318
319 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
320 this->external_name(), k->external_name());
321 return nest_host_k;
322 } else {
323 error = "current type is not listed as a nest member";
324 }
325 } else {
326 error = "host is not an instance class";
327 }
328 } else {
329 error = "types are in different packages";
330 }
331
332 // something went wrong, so record what and log it
333 {
334 stringStream ss;
335 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
336 this->external_name(),
337 this->class_loader_data()->loader_name_and_id(),
338 k->external_name(),
339 k->class_loader_data()->loader_name_and_id(),
340 error);
341 const char* msg = ss.as_string(true /* on C-heap */);
342 constantPoolHandle cph(THREAD, constants());
343 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
344 log_trace(class, nestmates)("%s", msg);
345 }
346 }
347 } else {
348 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
349 this->external_name());
350 }
351
352 // Either not in an explicit nest, or else an error occurred, so
353 // the nest-host is set to `this`. Any thread that sees this assignment
354 // will also see any setting of nest_host_error(), if applicable.
355 return (_nest_host = this);
356 }
357
358 // Dynamic nest member support: set this class's nest host to the given class.
359 // This occurs as part of the class definition, as soon as the instanceKlass
360 // has been created and doesn't require further resolution. The code:
361 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
362 // results in:
363 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
364 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
365 // We also know the "host" is a valid nest-host in the same package so we can
366 // assert some of those facts.
367 void InstanceKlass::set_nest_host(InstanceKlass* host) {
368 assert(is_hidden(), "must be a hidden class");
369 assert(host != nullptr, "null nest host specified");
370 assert(_nest_host == nullptr, "current class has resolved nest-host");
371 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
372 nest_host_error());
373 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
374 (host->_nest_host == host), "proposed host is not a valid nest-host");
375 // Can't assert this as package is not set yet:
376 // assert(is_same_class_package(host), "proposed host is in wrong package");
377
378 if (log_is_enabled(Trace, class, nestmates)) {
379 ResourceMark rm;
380 const char* msg = "";
381 // a hidden class does not expect a statically defined nest-host
382 if (_nest_host_index > 0) {
383 msg = "(the NestHost attribute in the current class is ignored)";
384 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
385 msg = "(the NestMembers attribute in the current class is ignored)";
386 }
387 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
388 this->external_name(),
389 host->external_name(),
390 msg);
391 }
392 // set dynamic nest host
393 _nest_host = host;
394 // Record dependency to keep nest host from being unloaded before this class.
395 ClassLoaderData* this_key = class_loader_data();
396 assert(this_key != nullptr, "sanity");
397 this_key->record_dependency(host);
398 }
399
400 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
401 // or we are k's nest_host - all of which is covered by comparing the two
402 // resolved_nest_hosts.
403 // Any exceptions (i.e. VMEs) are propagated.
404 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
405
406 assert(this != k, "this should be handled by higher-level code");
407
408 // Per JVMS 5.4.4 we first resolve and validate the current class, then
409 // the target class k.
410
411 InstanceKlass* cur_host = nest_host(CHECK_false);
412 if (cur_host == nullptr) {
413 return false;
414 }
415
416 Klass* k_nest_host = k->nest_host(CHECK_false);
417 if (k_nest_host == nullptr) {
418 return false;
419 }
420
421 bool access = (cur_host == k_nest_host);
422
423 ResourceMark rm(THREAD);
424 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
425 this->external_name(),
426 access ? "" : "NOT ",
427 k->external_name());
428 return access;
429 }
430
431 const char* InstanceKlass::nest_host_error() {
432 if (_nest_host_index == 0) {
433 return nullptr;
434 } else {
435 constantPoolHandle cph(Thread::current(), constants());
436 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
437 }
438 }
439
440 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
441 const int size = InstanceKlass::size(parser.vtable_size(),
442 parser.itable_size(),
443 nonstatic_oop_map_size(parser.total_oop_map_count()),
444 parser.is_interface());
445
446 const Symbol* const class_name = parser.class_name();
447 assert(class_name != nullptr, "invariant");
448 ClassLoaderData* loader_data = parser.loader_data();
449 assert(loader_data != nullptr, "invariant");
450
451 InstanceKlass* ik;
452
453 // Allocation
454 if (parser.is_instance_ref_klass()) {
455 // java.lang.ref.Reference
456 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
457 } else if (class_name == vmSymbols::java_lang_Class()) {
458 // mirror - java.lang.Class
459 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
460 } else if (is_stack_chunk_class(class_name, loader_data)) {
461 // stack chunk
462 ik = new (loader_data, size, THREAD) InstanceStackChunkKlass(parser);
463 } else if (is_class_loader(class_name, parser)) {
464 // class loader - java.lang.ClassLoader
465 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
466 } else {
467 // normal
468 ik = new (loader_data, size, THREAD) InstanceKlass(parser);
469 }
470
471 // Check for pending exception before adding to the loader data and incrementing
472 // class count. Can get OOM here.
473 if (HAS_PENDING_EXCEPTION) {
474 return nullptr;
475 }
476
477 return ik;
478 }
479
480
481 // copy method ordering from resource area to Metaspace
482 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
483 if (m != nullptr) {
484 // allocate a new array and copy contents (memcpy?)
485 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
486 for (int i = 0; i < m->length(); i++) {
487 _method_ordering->at_put(i, m->at(i));
488 }
489 } else {
490 _method_ordering = Universe::the_empty_int_array();
491 }
492 }
493
494 // create a new array of vtable_indices for default methods
495 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
496 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
497 assert(default_vtable_indices() == nullptr, "only create once");
498 set_default_vtable_indices(vtable_indices);
499 return vtable_indices;
500 }
501
502
503 InstanceKlass::InstanceKlass() {
504 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
505 }
506
507 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
508 Klass(kind),
509 _nest_members(nullptr),
510 _nest_host(nullptr),
511 _permitted_subclasses(nullptr),
512 _record_components(nullptr),
513 _static_field_size(parser.static_field_size()),
514 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
515 _itable_len(parser.itable_size()),
516 _nest_host_index(0),
517 _init_state(allocated),
518 _reference_type(reference_type),
519 _init_thread(nullptr)
520 {
521 set_vtable_length(parser.vtable_size());
522 set_access_flags(parser.access_flags());
523 if (parser.is_hidden()) set_is_hidden();
524 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
525 false));
526
527 assert(nullptr == _methods, "underlying memory not zeroed?");
528 assert(is_instance_klass(), "is layout incorrect?");
529 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
530 }
531
532 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
533 Array<Method*>* methods) {
534 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
535 !methods->is_shared()) {
536 for (int i = 0; i < methods->length(); i++) {
537 Method* method = methods->at(i);
538 if (method == nullptr) continue; // maybe null if error processing
539 // Only want to delete methods that are not executing for RedefineClasses.
540 // The previous version will point to them so they're not totally dangling
541 assert (!method->on_stack(), "shouldn't be called with methods on stack");
542 MetadataFactory::free_metadata(loader_data, method);
543 }
544 MetadataFactory::free_array<Method*>(loader_data, methods);
545 }
546 }
547
548 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
549 const Klass* super_klass,
550 Array<InstanceKlass*>* local_interfaces,
551 Array<InstanceKlass*>* transitive_interfaces) {
552 // Only deallocate transitive interfaces if not empty, same as super class
553 // or same as local interfaces. See code in parseClassFile.
554 Array<InstanceKlass*>* ti = transitive_interfaces;
555 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
556 // check that the interfaces don't come from super class
557 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
558 InstanceKlass::cast(super_klass)->transitive_interfaces();
559 if (ti != sti && ti != nullptr && !ti->is_shared()) {
560 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
561 }
562 }
563
564 // local interfaces can be empty
565 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
566 local_interfaces != nullptr && !local_interfaces->is_shared()) {
567 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
568 }
569 }
570
571 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
572 Array<RecordComponent*>* record_components) {
573 if (record_components != nullptr && !record_components->is_shared()) {
574 for (int i = 0; i < record_components->length(); i++) {
575 RecordComponent* record_component = record_components->at(i);
576 MetadataFactory::free_metadata(loader_data, record_component);
577 }
578 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
579 }
580 }
581
582 // This function deallocates the metadata and C heap pointers that the
583 // InstanceKlass points to.
584 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
585 // Orphan the mirror first, CMS thinks it's still live.
586 if (java_mirror() != nullptr) {
587 java_lang_Class::set_klass(java_mirror(), nullptr);
588 }
589
590 // Also remove mirror from handles
591 loader_data->remove_handle(_java_mirror);
592
593 // Need to take this class off the class loader data list.
594 loader_data->remove_class(this);
595
596 // The array_klass for this class is created later, after error handling.
597 // For class redefinition, we keep the original class so this scratch class
598 // doesn't have an array class. Either way, assert that there is nothing
599 // to deallocate.
600 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
601
602 // Release C heap allocated data that this points to, which includes
603 // reference counting symbol names.
604 // Can't release the constant pool or MethodData C heap data here because the constant
605 // pool can be deallocated separately from the InstanceKlass for default methods and
606 // redefine classes. MethodData can also be released separately.
607 release_C_heap_structures(/* release_sub_metadata */ false);
608
609 deallocate_methods(loader_data, methods());
610 set_methods(nullptr);
611
612 deallocate_record_components(loader_data, record_components());
613 set_record_components(nullptr);
614
615 if (method_ordering() != nullptr &&
616 method_ordering() != Universe::the_empty_int_array() &&
617 !method_ordering()->is_shared()) {
618 MetadataFactory::free_array<int>(loader_data, method_ordering());
619 }
620 set_method_ordering(nullptr);
621
622 // default methods can be empty
623 if (default_methods() != nullptr &&
624 default_methods() != Universe::the_empty_method_array() &&
625 !default_methods()->is_shared()) {
626 MetadataFactory::free_array<Method*>(loader_data, default_methods());
627 }
628 // Do NOT deallocate the default methods, they are owned by superinterfaces.
629 set_default_methods(nullptr);
630
631 // default methods vtable indices can be empty
632 if (default_vtable_indices() != nullptr &&
633 !default_vtable_indices()->is_shared()) {
634 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
635 }
636 set_default_vtable_indices(nullptr);
637
638
639 // This array is in Klass, but remove it with the InstanceKlass since
640 // this place would be the only caller and it can share memory with transitive
641 // interfaces.
642 if (secondary_supers() != nullptr &&
643 secondary_supers() != Universe::the_empty_klass_array() &&
644 // see comments in compute_secondary_supers about the following cast
645 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
646 !secondary_supers()->is_shared()) {
647 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
648 }
649 set_secondary_supers(nullptr);
650
651 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
652 set_transitive_interfaces(nullptr);
653 set_local_interfaces(nullptr);
654
655 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
656 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
657 }
658 set_fieldinfo_stream(nullptr);
659
660 if (fields_status() != nullptr && !fields_status()->is_shared()) {
661 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
662 }
663 set_fields_status(nullptr);
664
665 // If a method from a redefined class is using this constant pool, don't
666 // delete it, yet. The new class's previous version will point to this.
667 if (constants() != nullptr) {
668 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
669 if (!constants()->is_shared()) {
670 MetadataFactory::free_metadata(loader_data, constants());
671 }
672 // Delete any cached resolution errors for the constant pool
673 SystemDictionary::delete_resolution_error(constants());
674
675 set_constants(nullptr);
676 }
677
678 if (inner_classes() != nullptr &&
679 inner_classes() != Universe::the_empty_short_array() &&
680 !inner_classes()->is_shared()) {
681 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
682 }
683 set_inner_classes(nullptr);
684
685 if (nest_members() != nullptr &&
686 nest_members() != Universe::the_empty_short_array() &&
687 !nest_members()->is_shared()) {
688 MetadataFactory::free_array<jushort>(loader_data, nest_members());
689 }
690 set_nest_members(nullptr);
691
692 if (permitted_subclasses() != nullptr &&
693 permitted_subclasses() != Universe::the_empty_short_array() &&
694 !permitted_subclasses()->is_shared()) {
695 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
696 }
697 set_permitted_subclasses(nullptr);
698
699 // We should deallocate the Annotations instance if it's not in shared spaces.
700 if (annotations() != nullptr && !annotations()->is_shared()) {
701 MetadataFactory::free_metadata(loader_data, annotations());
702 }
703 set_annotations(nullptr);
704
705 SystemDictionaryShared::handle_class_unloading(this);
706
707 #if INCLUDE_CDS_JAVA_HEAP
708 if (CDSConfig::is_dumping_heap()) {
709 HeapShared::remove_scratch_objects(this);
710 }
711 #endif
712 }
713
714 bool InstanceKlass::is_record() const {
715 return _record_components != nullptr &&
716 is_final() &&
717 java_super() == vmClasses::Record_klass();
718 }
719
720 bool InstanceKlass::is_sealed() const {
721 return _permitted_subclasses != nullptr &&
722 _permitted_subclasses != Universe::the_empty_short_array();
723 }
724
725 bool InstanceKlass::should_be_initialized() const {
726 return !is_initialized();
727 }
728
729 klassItable InstanceKlass::itable() const {
730 return klassItable(const_cast<InstanceKlass*>(this));
731 }
732
733 // JVMTI spec thinks there are signers and protection domain in the
734 // instanceKlass. These accessors pretend these fields are there.
735 // The hprof specification also thinks these fields are in InstanceKlass.
736 oop InstanceKlass::protection_domain() const {
737 // return the protection_domain from the mirror
738 return java_lang_Class::protection_domain(java_mirror());
739 }
740
741 objArrayOop InstanceKlass::signers() const {
742 // return the signers from the mirror
743 return java_lang_Class::signers(java_mirror());
744 }
745
746 oop InstanceKlass::init_lock() const {
747 // return the init lock from the mirror
748 oop lock = java_lang_Class::init_lock(java_mirror());
749 // Prevent reordering with any access of initialization state
750 OrderAccess::loadload();
751 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
752 "only fully initialized state can have a null lock");
753 return lock;
754 }
755
756 // Set the initialization lock to null so the object can be GC'ed. Any racing
757 // threads to get this lock will see a null lock and will not lock.
758 // That's okay because they all check for initialized state after getting
759 // the lock and return.
760 void InstanceKlass::fence_and_clear_init_lock() {
761 // make sure previous stores are all done, notably the init_state.
762 OrderAccess::storestore();
763 java_lang_Class::clear_init_lock(java_mirror());
764 assert(!is_not_initialized(), "class must be initialized now");
765 }
766
767
768 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
769 // process. The step comments refers to the procedure described in that section.
770 // Note: implementation moved to static method to expose the this pointer.
771 void InstanceKlass::initialize(TRAPS) {
772 if (this->should_be_initialized()) {
773 initialize_impl(CHECK);
774 // Note: at this point the class may be initialized
775 // OR it may be in the state of being initialized
776 // in case of recursive initialization!
777 } else {
778 assert(is_initialized(), "sanity check");
779 }
780 }
781
782
783 bool InstanceKlass::verify_code(TRAPS) {
784 // 1) Verify the bytecodes
785 return Verifier::verify(this, should_verify_class(), THREAD);
786 }
787
788 void InstanceKlass::link_class(TRAPS) {
789 assert(is_loaded(), "must be loaded");
790 if (!is_linked()) {
791 link_class_impl(CHECK);
792 }
793 }
794
795 // Called to verify that a class can link during initialization, without
796 // throwing a VerifyError.
797 bool InstanceKlass::link_class_or_fail(TRAPS) {
798 assert(is_loaded(), "must be loaded");
799 if (!is_linked()) {
800 link_class_impl(CHECK_false);
801 }
802 return is_linked();
803 }
804
805 bool InstanceKlass::link_class_impl(TRAPS) {
806 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
807 // This is for CDS static dump only -- we use the in_error_state to indicate that
808 // the class has failed verification. Throwing the NoClassDefFoundError here is just
809 // a convenient way to stop repeat attempts to verify the same (bad) class.
810 //
811 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
812 // if we are executing Java code. This is not a problem for CDS dumping phase since
813 // it doesn't execute any Java code.
814 ResourceMark rm(THREAD);
815 Exceptions::fthrow(THREAD_AND_LOCATION,
816 vmSymbols::java_lang_NoClassDefFoundError(),
817 "Class %s, or one of its supertypes, failed class initialization",
818 external_name());
819 return false;
820 }
821 // return if already verified
822 if (is_linked()) {
823 return true;
824 }
825
826 // Timing
827 // timer handles recursion
828 JavaThread* jt = THREAD;
829
830 // link super class before linking this class
831 Klass* super_klass = super();
832 if (super_klass != nullptr) {
833 if (super_klass->is_interface()) { // check if super class is an interface
834 ResourceMark rm(THREAD);
835 Exceptions::fthrow(
836 THREAD_AND_LOCATION,
837 vmSymbols::java_lang_IncompatibleClassChangeError(),
838 "class %s has interface %s as super class",
839 external_name(),
840 super_klass->external_name()
841 );
842 return false;
843 }
844
845 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
846 ik_super->link_class_impl(CHECK_false);
847 }
848
849 // link all interfaces implemented by this class before linking this class
850 Array<InstanceKlass*>* interfaces = local_interfaces();
851 int num_interfaces = interfaces->length();
852 for (int index = 0; index < num_interfaces; index++) {
853 InstanceKlass* interk = interfaces->at(index);
854 interk->link_class_impl(CHECK_false);
855 }
856
857 // in case the class is linked in the process of linking its superclasses
858 if (is_linked()) {
859 return true;
860 }
861
862 // trace only the link time for this klass that includes
863 // the verification time
864 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
865 ClassLoader::perf_class_link_selftime(),
866 ClassLoader::perf_classes_linked(),
867 jt->get_thread_stat()->perf_recursion_counts_addr(),
868 jt->get_thread_stat()->perf_timers_addr(),
869 PerfClassTraceTime::CLASS_LINK);
870
871 // verification & rewriting
872 {
873 HandleMark hm(THREAD);
874 Handle h_init_lock(THREAD, init_lock());
875 ObjectLocker ol(h_init_lock, jt);
876 // rewritten will have been set if loader constraint error found
877 // on an earlier link attempt
878 // don't verify or rewrite if already rewritten
879 //
880
881 if (!is_linked()) {
882 if (!is_rewritten()) {
883 if (is_shared()) {
884 assert(!verified_at_dump_time(), "must be");
885 }
886 {
887 bool verify_ok = verify_code(THREAD);
888 if (!verify_ok) {
889 return false;
890 }
891 }
892
893 // Just in case a side-effect of verify linked this class already
894 // (which can sometimes happen since the verifier loads classes
895 // using custom class loaders, which are free to initialize things)
896 if (is_linked()) {
897 return true;
898 }
899
900 // also sets rewritten
901 rewrite_class(CHECK_false);
902 } else if (is_shared()) {
903 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
904 }
905
906 // relocate jsrs and link methods after they are all rewritten
907 link_methods(CHECK_false);
908
909 // Initialize the vtable and interface table after
910 // methods have been rewritten since rewrite may
911 // fabricate new Method*s.
912 // also does loader constraint checking
913 //
914 // initialize_vtable and initialize_itable need to be rerun
915 // for a shared class if
916 // 1) the class is loaded by custom class loader or
917 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
918 // 3) the class was not verified during dump time
919 bool need_init_table = true;
920 if (is_shared() && verified_at_dump_time() &&
921 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
922 need_init_table = false;
923 }
924 if (need_init_table) {
925 vtable().initialize_vtable_and_check_constraints(CHECK_false);
926 itable().initialize_itable_and_check_constraints(CHECK_false);
927 }
928 #ifdef ASSERT
929 vtable().verify(tty, true);
930 // In case itable verification is ever added.
931 // itable().verify(tty, true);
932 #endif
933 if (Universe::is_fully_initialized()) {
934 DeoptimizationScope deopt_scope;
935 {
936 // Now mark all code that assumes the class is not linked.
937 // Set state under the Compile_lock also.
938 MutexLocker ml(THREAD, Compile_lock);
939
940 set_init_state(linked);
941 CodeCache::mark_dependents_on(&deopt_scope, this);
942 }
943 // Perform the deopt handshake outside Compile_lock.
944 deopt_scope.deoptimize_marked();
945 } else {
946 set_init_state(linked);
947 }
948 if (JvmtiExport::should_post_class_prepare()) {
949 JvmtiExport::post_class_prepare(THREAD, this);
950 }
951 }
952 }
953 return true;
954 }
955
956 // Rewrite the byte codes of all of the methods of a class.
957 // The rewriter must be called exactly once. Rewriting must happen after
958 // verification but before the first method of the class is executed.
959 void InstanceKlass::rewrite_class(TRAPS) {
960 assert(is_loaded(), "must be loaded");
961 if (is_rewritten()) {
962 assert(is_shared(), "rewriting an unshared class?");
963 return;
964 }
965 Rewriter::rewrite(this, CHECK);
966 set_rewritten();
967 }
968
969 // Now relocate and link method entry points after class is rewritten.
970 // This is outside is_rewritten flag. In case of an exception, it can be
971 // executed more than once.
972 void InstanceKlass::link_methods(TRAPS) {
973 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
974
975 int len = methods()->length();
976 for (int i = len-1; i >= 0; i--) {
977 methodHandle m(THREAD, methods()->at(i));
978
979 // Set up method entry points for compiler and interpreter .
980 m->link_method(m, CHECK);
981 }
982 }
983
984 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
985 void InstanceKlass::initialize_super_interfaces(TRAPS) {
986 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
987 for (int i = 0; i < local_interfaces()->length(); ++i) {
988 InstanceKlass* ik = local_interfaces()->at(i);
989
990 // Initialization is depth first search ie. we start with top of the inheritance tree
991 // has_nonstatic_concrete_methods drives searching superinterfaces since it
992 // means has_nonstatic_concrete_methods in its superinterface hierarchy
993 if (ik->has_nonstatic_concrete_methods()) {
994 ik->initialize_super_interfaces(CHECK);
995 }
996
997 // Only initialize() interfaces that "declare" concrete methods.
998 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
999 ik->initialize(CHECK);
1000 }
1001 }
1002 }
1003
1004 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1005 static InitializationErrorTable* _initialization_error_table;
1006
1007 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1008 // Create the same exception with a message indicating the thread name,
1009 // and the StackTraceElements.
1010 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1011 ResourceMark rm(current);
1012 if (init_error.is_null()) {
1013 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1014
1015 // We failed to create the new exception, most likely due to either out-of-memory or
1016 // a stackoverflow error. If the original exception was either of those then we save
1017 // the shared, pre-allocated, stackless, instance of that exception.
1018 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1019 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1020 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1021 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1022 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1023 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1024 } else {
1025 return;
1026 }
1027 }
1028
1029 MutexLocker ml(current, ClassInitError_lock);
1030 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1031 bool created;
1032 if (_initialization_error_table == nullptr) {
1033 _initialization_error_table = new (mtClass) InitializationErrorTable();
1034 }
1035 _initialization_error_table->put_if_absent(this, elem, &created);
1036 assert(created, "Initialization is single threaded");
1037 log_trace(class, init)("Initialization error added for class %s", external_name());
1038 }
1039
1040 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1041 MutexLocker ml(current, ClassInitError_lock);
1042 if (_initialization_error_table == nullptr) {
1043 return nullptr;
1044 }
1045 OopHandle* h = _initialization_error_table->get(this);
1046 return (h != nullptr) ? h->resolve() : nullptr;
1047 }
1048
1049 // Need to remove entries for unloaded classes.
1050 void InstanceKlass::clean_initialization_error_table() {
1051 struct InitErrorTableCleaner {
1052 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1053 if (!ik->is_loader_alive()) {
1054 h.release(Universe::vm_global());
1055 return true;
1056 } else {
1057 return false;
1058 }
1059 }
1060 };
1061
1062 assert_locked_or_safepoint(ClassInitError_lock);
1063 InitErrorTableCleaner cleaner;
1064 if (_initialization_error_table != nullptr) {
1065 _initialization_error_table->unlink(&cleaner);
1066 }
1067 }
1068
1069 void InstanceKlass::initialize_impl(TRAPS) {
1070 HandleMark hm(THREAD);
1071
1072 // Make sure klass is linked (verified) before initialization
1073 // A class could already be verified, since it has been reflected upon.
1074 link_class(CHECK);
1075
1076 DTRACE_CLASSINIT_PROBE(required, -1);
1077
1078 bool wait = false;
1079
1080 JavaThread* jt = THREAD;
1081
1082 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1083
1084 // refer to the JVM book page 47 for description of steps
1085 // Step 1
1086 {
1087 Handle h_init_lock(THREAD, init_lock());
1088 ObjectLocker ol(h_init_lock, jt);
1089
1090 // Step 2
1091 // If we were to use wait() instead of waitInterruptibly() then
1092 // we might end up throwing IE from link/symbol resolution sites
1093 // that aren't expected to throw. This would wreak havoc. See 6320309.
1094 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1095 if (debug_logging_enabled) {
1096 ResourceMark rm(jt);
1097 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1098 jt->name(), external_name(), init_thread_name());
1099 }
1100 wait = true;
1101 jt->set_class_to_be_initialized(this);
1102 ol.wait_uninterruptibly(jt);
1103 jt->set_class_to_be_initialized(nullptr);
1104 }
1105
1106 // Step 3
1107 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1108 if (debug_logging_enabled) {
1109 ResourceMark rm(jt);
1110 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1111 jt->name(), external_name());
1112 }
1113 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1114 return;
1115 }
1116
1117 // Step 4
1118 if (is_initialized()) {
1119 if (debug_logging_enabled) {
1120 ResourceMark rm(jt);
1121 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1122 jt->name(), external_name());
1123 }
1124 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1125 return;
1126 }
1127
1128 // Step 5
1129 if (is_in_error_state()) {
1130 if (debug_logging_enabled) {
1131 ResourceMark rm(jt);
1132 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1133 jt->name(), external_name());
1134 }
1135
1136 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1137 ResourceMark rm(THREAD);
1138 Handle cause(THREAD, get_initialization_error(THREAD));
1139
1140 stringStream ss;
1141 ss.print("Could not initialize class %s", external_name());
1142 if (cause.is_null()) {
1143 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1144 } else {
1145 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1146 ss.as_string(), cause);
1147 }
1148 } else {
1149
1150 // Step 6
1151 set_init_state(being_initialized);
1152 set_init_thread(jt);
1153 if (debug_logging_enabled) {
1154 ResourceMark rm(jt);
1155 log_debug(class, init)("Thread \"%s\" is initializing %s",
1156 jt->name(), external_name());
1157 }
1158 }
1159 }
1160
1161 // Step 7
1162 // Next, if C is a class rather than an interface, initialize it's super class and super
1163 // interfaces.
1164 if (!is_interface()) {
1165 Klass* super_klass = super();
1166 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1167 super_klass->initialize(THREAD);
1168 }
1169 // If C implements any interface that declares a non-static, concrete method,
1170 // the initialization of C triggers initialization of its super interfaces.
1171 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1172 // having a superinterface that declares, non-static, concrete methods
1173 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1174 initialize_super_interfaces(THREAD);
1175 }
1176
1177 // If any exceptions, complete abruptly, throwing the same exception as above.
1178 if (HAS_PENDING_EXCEPTION) {
1179 Handle e(THREAD, PENDING_EXCEPTION);
1180 CLEAR_PENDING_EXCEPTION;
1181 {
1182 EXCEPTION_MARK;
1183 add_initialization_error(THREAD, e);
1184 // Locks object, set state, and notify all waiting threads
1185 set_initialization_state_and_notify(initialization_error, THREAD);
1186 CLEAR_PENDING_EXCEPTION;
1187 }
1188 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1189 THROW_OOP(e());
1190 }
1191 }
1192
1193
1194 // Step 8
1195 {
1196 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1197 if (class_initializer() != nullptr) {
1198 // Timer includes any side effects of class initialization (resolution,
1199 // etc), but not recursive entry into call_class_initializer().
1200 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1201 ClassLoader::perf_class_init_selftime(),
1202 ClassLoader::perf_classes_inited(),
1203 jt->get_thread_stat()->perf_recursion_counts_addr(),
1204 jt->get_thread_stat()->perf_timers_addr(),
1205 PerfClassTraceTime::CLASS_CLINIT);
1206 call_class_initializer(THREAD);
1207 } else {
1208 // The elapsed time is so small it's not worth counting.
1209 if (UsePerfData) {
1210 ClassLoader::perf_classes_inited()->inc();
1211 }
1212 call_class_initializer(THREAD);
1213 }
1214 }
1215
1216 // Step 9
1217 if (!HAS_PENDING_EXCEPTION) {
1218 set_initialization_state_and_notify(fully_initialized, CHECK);
1219 debug_only(vtable().verify(tty, true);)
1220 }
1221 else {
1222 // Step 10 and 11
1223 Handle e(THREAD, PENDING_EXCEPTION);
1224 CLEAR_PENDING_EXCEPTION;
1225 // JVMTI has already reported the pending exception
1226 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1227 JvmtiExport::clear_detected_exception(jt);
1228 {
1229 EXCEPTION_MARK;
1230 add_initialization_error(THREAD, e);
1231 set_initialization_state_and_notify(initialization_error, THREAD);
1232 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1233 // JVMTI has already reported the pending exception
1234 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1235 JvmtiExport::clear_detected_exception(jt);
1236 }
1237 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1238 if (e->is_a(vmClasses::Error_klass())) {
1239 THROW_OOP(e());
1240 } else {
1241 JavaCallArguments args(e);
1242 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1243 vmSymbols::throwable_void_signature(),
1244 &args);
1245 }
1246 }
1247 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1248 }
1249
1250
1251 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1252 Handle h_init_lock(THREAD, init_lock());
1253 if (h_init_lock() != nullptr) {
1254 ObjectLocker ol(h_init_lock, THREAD);
1255 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1256 set_init_state(state);
1257 fence_and_clear_init_lock();
1258 ol.notify_all(CHECK);
1259 } else {
1260 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1261 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1262 set_init_state(state);
1263 }
1264 }
1265
1266 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1267 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1268 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1269 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1270
1271 DeoptimizationScope deopt_scope;
1272 {
1273 MutexLocker ml(current, Compile_lock);
1274
1275 set_init_state(InstanceKlass::loaded);
1276 // make sure init_state store is already done.
1277 // The compiler reads the hierarchy outside of the Compile_lock.
1278 // Access ordering is used to add to hierarchy.
1279
1280 // Link into hierarchy.
1281 append_to_sibling_list(); // add to superklass/sibling list
1282 process_interfaces(); // handle all "implements" declarations
1283
1284 // Now mark all code that depended on old class hierarchy.
1285 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1286 if (Universe::is_fully_initialized()) {
1287 CodeCache::mark_dependents_on(&deopt_scope, this);
1288 }
1289 }
1290 // Perform the deopt handshake outside Compile_lock.
1291 deopt_scope.deoptimize_marked();
1292 }
1293
1294
1295 InstanceKlass* InstanceKlass::implementor() const {
1296 InstanceKlass* volatile* ik = adr_implementor();
1297 if (ik == nullptr) {
1298 return nullptr;
1299 } else {
1300 // This load races with inserts, and therefore needs acquire.
1301 InstanceKlass* ikls = Atomic::load_acquire(ik);
1302 if (ikls != nullptr && !ikls->is_loader_alive()) {
1303 return nullptr; // don't return unloaded class
1304 } else {
1305 return ikls;
1306 }
1307 }
1308 }
1309
1310
1311 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1312 assert_locked_or_safepoint(Compile_lock);
1313 assert(is_interface(), "not interface");
1314 InstanceKlass* volatile* addr = adr_implementor();
1315 assert(addr != nullptr, "null addr");
1316 if (addr != nullptr) {
1317 Atomic::release_store(addr, ik);
1318 }
1319 }
1320
1321 int InstanceKlass::nof_implementors() const {
1322 InstanceKlass* ik = implementor();
1323 if (ik == nullptr) {
1324 return 0;
1325 } else if (ik != this) {
1326 return 1;
1327 } else {
1328 return 2;
1329 }
1330 }
1331
1332 // The embedded _implementor field can only record one implementor.
1333 // When there are more than one implementors, the _implementor field
1334 // is set to the interface Klass* itself. Following are the possible
1335 // values for the _implementor field:
1336 // null - no implementor
1337 // implementor Klass* - one implementor
1338 // self - more than one implementor
1339 //
1340 // The _implementor field only exists for interfaces.
1341 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1342 if (Universe::is_fully_initialized()) {
1343 assert_lock_strong(Compile_lock);
1344 }
1345 assert(is_interface(), "not interface");
1346 // Filter out my subinterfaces.
1347 // (Note: Interfaces are never on the subklass list.)
1348 if (ik->is_interface()) return;
1349
1350 // Filter out subclasses whose supers already implement me.
1351 // (Note: CHA must walk subclasses of direct implementors
1352 // in order to locate indirect implementors.)
1353 InstanceKlass* super_ik = ik->java_super();
1354 if (super_ik != nullptr && super_ik->implements_interface(this))
1355 // We only need to check one immediate superclass, since the
1356 // implements_interface query looks at transitive_interfaces.
1357 // Any supers of the super have the same (or fewer) transitive_interfaces.
1358 return;
1359
1360 InstanceKlass* iklass = implementor();
1361 if (iklass == nullptr) {
1362 set_implementor(ik);
1363 } else if (iklass != this && iklass != ik) {
1364 // There is already an implementor. Use itself as an indicator of
1365 // more than one implementors.
1366 set_implementor(this);
1367 }
1368
1369 // The implementor also implements the transitive_interfaces
1370 for (int index = 0; index < local_interfaces()->length(); index++) {
1371 local_interfaces()->at(index)->add_implementor(ik);
1372 }
1373 }
1374
1375 void InstanceKlass::init_implementor() {
1376 if (is_interface()) {
1377 set_implementor(nullptr);
1378 }
1379 }
1380
1381
1382 void InstanceKlass::process_interfaces() {
1383 // link this class into the implementors list of every interface it implements
1384 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1385 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1386 InstanceKlass* interf = local_interfaces()->at(i);
1387 assert(interf->is_interface(), "expected interface");
1388 interf->add_implementor(this);
1389 }
1390 }
1391
1392 bool InstanceKlass::can_be_primary_super_slow() const {
1393 if (is_interface())
1394 return false;
1395 else
1396 return Klass::can_be_primary_super_slow();
1397 }
1398
1399 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1400 Array<InstanceKlass*>* transitive_interfaces) {
1401 // The secondaries are the implemented interfaces.
1402 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1403 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1404 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1405 int num_secondaries = num_extra_slots + interfaces->length();
1406 if (num_secondaries == 0) {
1407 // Must share this for correct bootstrapping!
1408 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1409 return nullptr;
1410 } else if (num_extra_slots == 0) {
1411 // The secondary super list is exactly the same as the transitive interfaces, so
1412 // let's use it instead of making a copy.
1413 // Redefine classes has to be careful not to delete this!
1414 if (!UseSecondarySupersTable) {
1415 set_secondary_supers(interfaces);
1416 return nullptr;
1417 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1418 // We will reuse the transitive interfaces list if we're certain
1419 // it's in hash order.
1420 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1421 set_secondary_supers(interfaces, bitmap);
1422 return nullptr;
1423 }
1424 // ... fall through if that didn't work.
1425 }
1426 // Copy transitive interfaces to a temporary growable array to be constructed
1427 // into the secondary super list with extra slots.
1428 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1429 for (int i = 0; i < interfaces->length(); i++) {
1430 secondaries->push(interfaces->at(i));
1431 }
1432 return secondaries;
1433 }
1434
1435 bool InstanceKlass::implements_interface(Klass* k) const {
1436 if (this == k) return true;
1437 assert(k->is_interface(), "should be an interface class");
1438 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1439 if (transitive_interfaces()->at(i) == k) {
1440 return true;
1441 }
1442 }
1443 return false;
1444 }
1445
1446 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1447 // Verify direct super interface
1448 if (this == k) return true;
1449 assert(k->is_interface(), "should be an interface class");
1450 for (int i = 0; i < local_interfaces()->length(); i++) {
1451 if (local_interfaces()->at(i) == k) {
1452 return true;
1453 }
1454 }
1455 return false;
1456 }
1457
1458 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1459 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1460 size_t size = objArrayOopDesc::object_size(length);
1461 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1462 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1463 /* do_zero */ true, CHECK_NULL);
1464 return o;
1465 }
1466
1467 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1468 if (TraceFinalizerRegistration) {
1469 tty->print("Registered ");
1470 i->print_value_on(tty);
1471 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1472 }
1473 instanceHandle h_i(THREAD, i);
1474 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1475 JavaValue result(T_VOID);
1476 JavaCallArguments args(h_i);
1477 methodHandle mh(THREAD, Universe::finalizer_register_method());
1478 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1479 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1480 return h_i();
1481 }
1482
1483 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1484 assert(!is_abstract() && !is_interface(), "Should not create this object");
1485 size_t size = size_helper(); // Query before forming handle.
1486 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1487 }
1488
1489 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1490 Klass* k = java_lang_Class::as_Klass(java_class);
1491 if (k == nullptr) {
1492 ResourceMark rm(THREAD);
1493 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1494 }
1495 InstanceKlass* ik = cast(k);
1496 ik->check_valid_for_instantiation(false, CHECK_NULL);
1497 ik->initialize(CHECK_NULL);
1498 return ik->allocate_instance(THREAD);
1499 }
1500
1501 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1502 return instanceHandle(THREAD, allocate_instance(THREAD));
1503 }
1504
1505 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1506 if (is_interface() || is_abstract()) {
1507 ResourceMark rm(THREAD);
1508 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1509 : vmSymbols::java_lang_InstantiationException(), external_name());
1510 }
1511 if (this == vmClasses::Class_klass()) {
1512 ResourceMark rm(THREAD);
1513 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1514 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1515 }
1516 }
1517
1518 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1519 // Need load-acquire for lock-free read
1520 if (array_klasses_acquire() == nullptr) {
1521
1522 // Recursively lock array allocation
1523 RecursiveLocker rl(MultiArray_lock, THREAD);
1524
1525 // Check if another thread created the array klass while we were waiting for the lock.
1526 if (array_klasses() == nullptr) {
1527 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1528 // use 'release' to pair with lock-free load
1529 release_set_array_klasses(k);
1530 }
1531 }
1532
1533 // array_klasses() will always be set at this point
1534 ObjArrayKlass* ak = array_klasses();
1535 assert(ak != nullptr, "should be set");
1536 return ak->array_klass(n, THREAD);
1537 }
1538
1539 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1540 // Need load-acquire for lock-free read
1541 ObjArrayKlass* oak = array_klasses_acquire();
1542 if (oak == nullptr) {
1543 return nullptr;
1544 } else {
1545 return oak->array_klass_or_null(n);
1546 }
1547 }
1548
1549 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1550 return array_klass(1, THREAD);
1551 }
1552
1553 ArrayKlass* InstanceKlass::array_klass_or_null() {
1554 return array_klass_or_null(1);
1555 }
1556
1557 static int call_class_initializer_counter = 0; // for debugging
1558
1559 Method* InstanceKlass::class_initializer() const {
1560 Method* clinit = find_method(
1561 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1562 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1563 return clinit;
1564 }
1565 return nullptr;
1566 }
1567
1568 void InstanceKlass::call_class_initializer(TRAPS) {
1569 if (ReplayCompiles &&
1570 (ReplaySuppressInitializers == 1 ||
1571 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1572 // Hide the existence of the initializer for the purpose of replaying the compile
1573 return;
1574 }
1575
1576 #if INCLUDE_CDS
1577 // This is needed to ensure the consistency of the archived heap objects.
1578 if (has_archived_enum_objs()) {
1579 assert(is_shared(), "must be");
1580 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1581 if (initialized) {
1582 return;
1583 }
1584 }
1585 #endif
1586
1587 methodHandle h_method(THREAD, class_initializer());
1588 assert(!is_initialized(), "we cannot initialize twice");
1589 LogTarget(Info, class, init) lt;
1590 if (lt.is_enabled()) {
1591 ResourceMark rm(THREAD);
1592 LogStream ls(lt);
1593 ls.print("%d Initializing ", call_class_initializer_counter++);
1594 name()->print_value_on(&ls);
1595 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1596 h_method() == nullptr ? "(no method)" : "", p2i(this),
1597 THREAD->name());
1598 }
1599 if (h_method() != nullptr) {
1600 JavaCallArguments args; // No arguments
1601 JavaValue result(T_VOID);
1602 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1603 }
1604 }
1605
1606
1607 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1608 InterpreterOopMap* entry_for) {
1609 // Lazily create the _oop_map_cache at first request.
1610 // Load_acquire is needed to safely get instance published with CAS by another thread.
1611 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1612 if (oop_map_cache == nullptr) {
1613 // Try to install new instance atomically.
1614 oop_map_cache = new OopMapCache();
1615 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1616 if (other != nullptr) {
1617 // Someone else managed to install before us, ditch local copy and use the existing one.
1618 delete oop_map_cache;
1619 oop_map_cache = other;
1620 }
1621 }
1622 // _oop_map_cache is constant after init; lookup below does its own locking.
1623 oop_map_cache->lookup(method, bci, entry_for);
1624 }
1625
1626 bool InstanceKlass::contains_field_offset(int offset) {
1627 fieldDescriptor fd;
1628 return find_field_from_offset(offset, false, &fd);
1629 }
1630
1631 FieldInfo InstanceKlass::field(int index) const {
1632 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1633 if (fs.index() == index) {
1634 return fs.to_FieldInfo();
1635 }
1636 }
1637 fatal("Field not found");
1638 return FieldInfo();
1639 }
1640
1641 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1642 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1643 Symbol* f_name = fs.name();
1644 Symbol* f_sig = fs.signature();
1645 if (f_name == name && f_sig == sig) {
1646 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1647 return true;
1648 }
1649 }
1650 return false;
1651 }
1652
1653
1654 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1655 const int n = local_interfaces()->length();
1656 for (int i = 0; i < n; i++) {
1657 Klass* intf1 = local_interfaces()->at(i);
1658 assert(intf1->is_interface(), "just checking type");
1659 // search for field in current interface
1660 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1661 assert(fd->is_static(), "interface field must be static");
1662 return intf1;
1663 }
1664 // search for field in direct superinterfaces
1665 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1666 if (intf2 != nullptr) return intf2;
1667 }
1668 // otherwise field lookup fails
1669 return nullptr;
1670 }
1671
1672
1673 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1674 // search order according to newest JVM spec (5.4.3.2, p.167).
1675 // 1) search for field in current klass
1676 if (find_local_field(name, sig, fd)) {
1677 return const_cast<InstanceKlass*>(this);
1678 }
1679 // 2) search for field recursively in direct superinterfaces
1680 { Klass* intf = find_interface_field(name, sig, fd);
1681 if (intf != nullptr) return intf;
1682 }
1683 // 3) apply field lookup recursively if superclass exists
1684 { Klass* supr = super();
1685 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1686 }
1687 // 4) otherwise field lookup fails
1688 return nullptr;
1689 }
1690
1691
1692 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1693 // search order according to newest JVM spec (5.4.3.2, p.167).
1694 // 1) search for field in current klass
1695 if (find_local_field(name, sig, fd)) {
1696 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1697 }
1698 // 2) search for field recursively in direct superinterfaces
1699 if (is_static) {
1700 Klass* intf = find_interface_field(name, sig, fd);
1701 if (intf != nullptr) return intf;
1702 }
1703 // 3) apply field lookup recursively if superclass exists
1704 { Klass* supr = super();
1705 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1706 }
1707 // 4) otherwise field lookup fails
1708 return nullptr;
1709 }
1710
1711
1712 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1713 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1714 if (fs.offset() == offset) {
1715 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1716 if (fd->is_static() == is_static) return true;
1717 }
1718 }
1719 return false;
1720 }
1721
1722
1723 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1724 Klass* klass = const_cast<InstanceKlass*>(this);
1725 while (klass != nullptr) {
1726 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1727 return true;
1728 }
1729 klass = klass->super();
1730 }
1731 return false;
1732 }
1733
1734
1735 void InstanceKlass::methods_do(void f(Method* method)) {
1736 // Methods aren't stable until they are loaded. This can be read outside
1737 // a lock through the ClassLoaderData for profiling
1738 // Redefined scratch classes are on the list and need to be cleaned
1739 if (!is_loaded() && !is_scratch_class()) {
1740 return;
1741 }
1742
1743 int len = methods()->length();
1744 for (int index = 0; index < len; index++) {
1745 Method* m = methods()->at(index);
1746 assert(m->is_method(), "must be method");
1747 f(m);
1748 }
1749 }
1750
1751
1752 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1753 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1754 if (fs.access_flags().is_static()) {
1755 fieldDescriptor& fd = fs.field_descriptor();
1756 cl->do_field(&fd);
1757 }
1758 }
1759 }
1760
1761
1762 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1763 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1764 if (fs.access_flags().is_static()) {
1765 fieldDescriptor& fd = fs.field_descriptor();
1766 f(&fd, mirror, CHECK);
1767 }
1768 }
1769 }
1770
1771 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1772 InstanceKlass* super = superklass();
1773 if (super != nullptr) {
1774 super->do_nonstatic_fields(cl);
1775 }
1776 fieldDescriptor fd;
1777 int length = java_fields_count();
1778 for (int i = 0; i < length; i += 1) {
1779 fd.reinitialize(this, i);
1780 if (!fd.is_static()) {
1781 cl->do_field(&fd);
1782 }
1783 }
1784 }
1785
1786 // first in Pair is offset, second is index.
1787 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1788 return a->first - b->first;
1789 }
1790
1791 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1792 InstanceKlass* super = superklass();
1793 if (super != nullptr) {
1794 super->print_nonstatic_fields(cl);
1795 }
1796 ResourceMark rm;
1797 fieldDescriptor fd;
1798 // In DebugInfo nonstatic fields are sorted by offset.
1799 GrowableArray<Pair<int,int> > fields_sorted;
1800 int i = 0;
1801 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1802 if (!fs.access_flags().is_static()) {
1803 fd = fs.field_descriptor();
1804 Pair<int,int> f(fs.offset(), fs.index());
1805 fields_sorted.push(f);
1806 i++;
1807 }
1808 }
1809 if (i > 0) {
1810 int length = i;
1811 assert(length == fields_sorted.length(), "duh");
1812 fields_sorted.sort(compare_fields_by_offset);
1813 for (int i = 0; i < length; i++) {
1814 fd.reinitialize(this, fields_sorted.at(i).second);
1815 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1816 cl->do_field(&fd);
1817 }
1818 }
1819 }
1820
1821 #ifdef ASSERT
1822 static int linear_search(const Array<Method*>* methods,
1823 const Symbol* name,
1824 const Symbol* signature) {
1825 const int len = methods->length();
1826 for (int index = 0; index < len; index++) {
1827 const Method* const m = methods->at(index);
1828 assert(m->is_method(), "must be method");
1829 if (m->signature() == signature && m->name() == name) {
1830 return index;
1831 }
1832 }
1833 return -1;
1834 }
1835 #endif
1836
1837 bool InstanceKlass::_disable_method_binary_search = false;
1838
1839 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1840 int len = methods->length();
1841 int l = 0;
1842 int h = len - 1;
1843 while (l <= h) {
1844 Method* m = methods->at(l);
1845 if (m->name() == name) {
1846 return l;
1847 }
1848 l++;
1849 }
1850 return -1;
1851 }
1852
1853 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1854 if (_disable_method_binary_search) {
1855 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1856 // At the final stage of dynamic dumping, the methods array may not be sorted
1857 // by ascending addresses of their names, so we can't use binary search anymore.
1858 // However, methods with the same name are still laid out consecutively inside the
1859 // methods array, so let's look for the first one that matches.
1860 return linear_search(methods, name);
1861 }
1862
1863 int len = methods->length();
1864 int l = 0;
1865 int h = len - 1;
1866
1867 // methods are sorted by ascending addresses of their names, so do binary search
1868 while (l <= h) {
1869 int mid = (l + h) >> 1;
1870 Method* m = methods->at(mid);
1871 assert(m->is_method(), "must be method");
1872 int res = m->name()->fast_compare(name);
1873 if (res == 0) {
1874 return mid;
1875 } else if (res < 0) {
1876 l = mid + 1;
1877 } else {
1878 h = mid - 1;
1879 }
1880 }
1881 return -1;
1882 }
1883
1884 // find_method looks up the name/signature in the local methods array
1885 Method* InstanceKlass::find_method(const Symbol* name,
1886 const Symbol* signature) const {
1887 return find_method_impl(name, signature,
1888 OverpassLookupMode::find,
1889 StaticLookupMode::find,
1890 PrivateLookupMode::find);
1891 }
1892
1893 Method* InstanceKlass::find_method_impl(const Symbol* name,
1894 const Symbol* signature,
1895 OverpassLookupMode overpass_mode,
1896 StaticLookupMode static_mode,
1897 PrivateLookupMode private_mode) const {
1898 return InstanceKlass::find_method_impl(methods(),
1899 name,
1900 signature,
1901 overpass_mode,
1902 static_mode,
1903 private_mode);
1904 }
1905
1906 // find_instance_method looks up the name/signature in the local methods array
1907 // and skips over static methods
1908 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1909 const Symbol* name,
1910 const Symbol* signature,
1911 PrivateLookupMode private_mode) {
1912 Method* const meth = InstanceKlass::find_method_impl(methods,
1913 name,
1914 signature,
1915 OverpassLookupMode::find,
1916 StaticLookupMode::skip,
1917 private_mode);
1918 assert(((meth == nullptr) || !meth->is_static()),
1919 "find_instance_method should have skipped statics");
1920 return meth;
1921 }
1922
1923 // find_instance_method looks up the name/signature in the local methods array
1924 // and skips over static methods
1925 Method* InstanceKlass::find_instance_method(const Symbol* name,
1926 const Symbol* signature,
1927 PrivateLookupMode private_mode) const {
1928 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1929 }
1930
1931 // Find looks up the name/signature in the local methods array
1932 // and filters on the overpass, static and private flags
1933 // This returns the first one found
1934 // note that the local methods array can have up to one overpass, one static
1935 // and one instance (private or not) with the same name/signature
1936 Method* InstanceKlass::find_local_method(const Symbol* name,
1937 const Symbol* signature,
1938 OverpassLookupMode overpass_mode,
1939 StaticLookupMode static_mode,
1940 PrivateLookupMode private_mode) const {
1941 return InstanceKlass::find_method_impl(methods(),
1942 name,
1943 signature,
1944 overpass_mode,
1945 static_mode,
1946 private_mode);
1947 }
1948
1949 // Find looks up the name/signature in the local methods array
1950 // and filters on the overpass, static and private flags
1951 // This returns the first one found
1952 // note that the local methods array can have up to one overpass, one static
1953 // and one instance (private or not) with the same name/signature
1954 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1955 const Symbol* name,
1956 const Symbol* signature,
1957 OverpassLookupMode overpass_mode,
1958 StaticLookupMode static_mode,
1959 PrivateLookupMode private_mode) {
1960 return InstanceKlass::find_method_impl(methods,
1961 name,
1962 signature,
1963 overpass_mode,
1964 static_mode,
1965 private_mode);
1966 }
1967
1968 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1969 const Symbol* name,
1970 const Symbol* signature) {
1971 return InstanceKlass::find_method_impl(methods,
1972 name,
1973 signature,
1974 OverpassLookupMode::find,
1975 StaticLookupMode::find,
1976 PrivateLookupMode::find);
1977 }
1978
1979 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1980 const Symbol* name,
1981 const Symbol* signature,
1982 OverpassLookupMode overpass_mode,
1983 StaticLookupMode static_mode,
1984 PrivateLookupMode private_mode) {
1985 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1986 return hit >= 0 ? methods->at(hit): nullptr;
1987 }
1988
1989 // true if method matches signature and conforms to skipping_X conditions.
1990 static bool method_matches(const Method* m,
1991 const Symbol* signature,
1992 bool skipping_overpass,
1993 bool skipping_static,
1994 bool skipping_private) {
1995 return ((m->signature() == signature) &&
1996 (!skipping_overpass || !m->is_overpass()) &&
1997 (!skipping_static || !m->is_static()) &&
1998 (!skipping_private || !m->is_private()));
1999 }
2000
2001 // Used directly for default_methods to find the index into the
2002 // default_vtable_indices, and indirectly by find_method
2003 // find_method_index looks in the local methods array to return the index
2004 // of the matching name/signature. If, overpass methods are being ignored,
2005 // the search continues to find a potential non-overpass match. This capability
2006 // is important during method resolution to prefer a static method, for example,
2007 // over an overpass method.
2008 // There is the possibility in any _method's array to have the same name/signature
2009 // for a static method, an overpass method and a local instance method
2010 // To correctly catch a given method, the search criteria may need
2011 // to explicitly skip the other two. For local instance methods, it
2012 // is often necessary to skip private methods
2013 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2014 const Symbol* name,
2015 const Symbol* signature,
2016 OverpassLookupMode overpass_mode,
2017 StaticLookupMode static_mode,
2018 PrivateLookupMode private_mode) {
2019 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2020 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2021 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2022 const int hit = quick_search(methods, name);
2023 if (hit != -1) {
2024 const Method* const m = methods->at(hit);
2025
2026 // Do linear search to find matching signature. First, quick check
2027 // for common case, ignoring overpasses if requested.
2028 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2029 return hit;
2030 }
2031
2032 // search downwards through overloaded methods
2033 int i;
2034 for (i = hit - 1; i >= 0; --i) {
2035 const Method* const m = methods->at(i);
2036 assert(m->is_method(), "must be method");
2037 if (m->name() != name) {
2038 break;
2039 }
2040 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2041 return i;
2042 }
2043 }
2044 // search upwards
2045 for (i = hit + 1; i < methods->length(); ++i) {
2046 const Method* const m = methods->at(i);
2047 assert(m->is_method(), "must be method");
2048 if (m->name() != name) {
2049 break;
2050 }
2051 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2052 return i;
2053 }
2054 }
2055 // not found
2056 #ifdef ASSERT
2057 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2058 linear_search(methods, name, signature);
2059 assert(-1 == index, "binary search should have found entry %d", index);
2060 #endif
2061 }
2062 return -1;
2063 }
2064
2065 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2066 return find_method_by_name(methods(), name, end);
2067 }
2068
2069 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2070 const Symbol* name,
2071 int* end_ptr) {
2072 assert(end_ptr != nullptr, "just checking");
2073 int start = quick_search(methods, name);
2074 int end = start + 1;
2075 if (start != -1) {
2076 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2077 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2078 *end_ptr = end;
2079 return start;
2080 }
2081 return -1;
2082 }
2083
2084 // uncached_lookup_method searches both the local class methods array and all
2085 // superclasses methods arrays, skipping any overpass methods in superclasses,
2086 // and possibly skipping private methods.
2087 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2088 const Symbol* signature,
2089 OverpassLookupMode overpass_mode,
2090 PrivateLookupMode private_mode) const {
2091 OverpassLookupMode overpass_local_mode = overpass_mode;
2092 const Klass* klass = this;
2093 while (klass != nullptr) {
2094 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2095 signature,
2096 overpass_local_mode,
2097 StaticLookupMode::find,
2098 private_mode);
2099 if (method != nullptr) {
2100 return method;
2101 }
2102 klass = klass->super();
2103 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2104 }
2105 return nullptr;
2106 }
2107
2108 #ifdef ASSERT
2109 // search through class hierarchy and return true if this class or
2110 // one of the superclasses was redefined
2111 bool InstanceKlass::has_redefined_this_or_super() const {
2112 const Klass* klass = this;
2113 while (klass != nullptr) {
2114 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2115 return true;
2116 }
2117 klass = klass->super();
2118 }
2119 return false;
2120 }
2121 #endif
2122
2123 // lookup a method in the default methods list then in all transitive interfaces
2124 // Do NOT return private or static methods
2125 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2126 Symbol* signature) const {
2127 Method* m = nullptr;
2128 if (default_methods() != nullptr) {
2129 m = find_method(default_methods(), name, signature);
2130 }
2131 // Look up interfaces
2132 if (m == nullptr) {
2133 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2134 }
2135 return m;
2136 }
2137
2138 // lookup a method in all the interfaces that this class implements
2139 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2140 // They should only be found in the initial InterfaceMethodRef
2141 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2142 Symbol* signature,
2143 DefaultsLookupMode defaults_mode) const {
2144 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2145 int num_ifs = all_ifs->length();
2146 InstanceKlass *ik = nullptr;
2147 for (int i = 0; i < num_ifs; i++) {
2148 ik = all_ifs->at(i);
2149 Method* m = ik->lookup_method(name, signature);
2150 if (m != nullptr && m->is_public() && !m->is_static() &&
2151 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2152 return m;
2153 }
2154 }
2155 return nullptr;
2156 }
2157
2158 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2159 :_st(st), _verbose(verbose) {
2160 ResourceMark rm;
2161 _st->print("%-18s ", "KlassAddr");
2162 _st->print("%-4s ", "Size");
2163 _st->print("%-20s ", "State");
2164 _st->print("%-7s ", "Flags");
2165 _st->print("%-5s ", "ClassName");
2166 _st->cr();
2167 }
2168
2169 void PrintClassClosure::do_klass(Klass* k) {
2170 ResourceMark rm;
2171 // klass pointer
2172 _st->print(PTR_FORMAT " ", p2i(k));
2173 // klass size
2174 _st->print("%4d ", k->size());
2175 // initialization state
2176 if (k->is_instance_klass()) {
2177 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2178 } else {
2179 _st->print("%-20s ","");
2180 }
2181 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2182 char buf[10];
2183 int i = 0;
2184 if (k->has_finalizer()) buf[i++] = 'F';
2185 if (k->is_instance_klass()) {
2186 InstanceKlass* ik = InstanceKlass::cast(k);
2187 if (ik->has_final_method()) buf[i++] = 'f';
2188 if (ik->is_rewritten()) buf[i++] = 'W';
2189 if (ik->is_contended()) buf[i++] = 'C';
2190 if (ik->has_been_redefined()) buf[i++] = 'R';
2191 if (ik->is_shared()) buf[i++] = 'S';
2192 }
2193 buf[i++] = '\0';
2194 _st->print("%-7s ", buf);
2195 // klass name
2196 _st->print("%-5s ", k->external_name());
2197 // end
2198 _st->cr();
2199 if (_verbose) {
2200 k->print_on(_st);
2201 }
2202 }
2203
2204 /* jni_id_for for jfieldIds only */
2205 JNIid* InstanceKlass::jni_id_for(int offset) {
2206 MutexLocker ml(JfieldIdCreation_lock);
2207 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2208 if (probe == nullptr) {
2209 // Allocate new static field identifier
2210 probe = new JNIid(this, offset, jni_ids());
2211 set_jni_ids(probe);
2212 }
2213 return probe;
2214 }
2215
2216 u2 InstanceKlass::enclosing_method_data(int offset) const {
2217 const Array<jushort>* const inner_class_list = inner_classes();
2218 if (inner_class_list == nullptr) {
2219 return 0;
2220 }
2221 const int length = inner_class_list->length();
2222 if (length % inner_class_next_offset == 0) {
2223 return 0;
2224 }
2225 const int index = length - enclosing_method_attribute_size;
2226 assert(offset < enclosing_method_attribute_size, "invalid offset");
2227 return inner_class_list->at(index + offset);
2228 }
2229
2230 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2231 u2 method_index) {
2232 Array<jushort>* inner_class_list = inner_classes();
2233 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2234 int length = inner_class_list->length();
2235 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2236 int index = length - enclosing_method_attribute_size;
2237 inner_class_list->at_put(
2238 index + enclosing_method_class_index_offset, class_index);
2239 inner_class_list->at_put(
2240 index + enclosing_method_method_index_offset, method_index);
2241 }
2242 }
2243
2244 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2245 if (method->is_old() && !method->is_obsolete()) {
2246 // If the method passed in is old (but not obsolete), use the current version.
2247 method = method_with_idnum((int)idnum);
2248 assert(method != nullptr, "old and but not obsolete, so should exist");
2249 }
2250 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2251 Atomic::release_store(&jmeths[idnum + 1], new_id);
2252 return new_id;
2253 }
2254
2255 // Lookup or create a jmethodID.
2256 // This code is called by the VMThread and JavaThreads so the
2257 // locking has to be done very carefully to avoid deadlocks
2258 // and/or other cache consistency problems.
2259 //
2260 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2261 Method* method = method_h();
2262 int idnum = method->method_idnum();
2263 jmethodID* jmeths = methods_jmethod_ids_acquire();
2264
2265 // We use a double-check locking idiom here because this cache is
2266 // performance sensitive. In the normal system, this cache only
2267 // transitions from null to non-null which is safe because we use
2268 // release_set_methods_jmethod_ids() to advertise the new cache.
2269 // A partially constructed cache should never be seen by a racing
2270 // thread. We also use release_store() to save a new jmethodID
2271 // in the cache so a partially constructed jmethodID should never be
2272 // seen either. Cache reads of existing jmethodIDs proceed without a
2273 // lock, but cache writes of a new jmethodID requires uniqueness and
2274 // creation of the cache itself requires no leaks so a lock is
2275 // acquired in those two cases.
2276 //
2277 // If the RedefineClasses() API has been used, then this cache grows
2278 // in the redefinition safepoint.
2279
2280 if (jmeths == nullptr) {
2281 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2282 jmeths = methods_jmethod_ids_acquire();
2283 // Still null?
2284 if (jmeths == nullptr) {
2285 size_t size = idnum_allocated_count();
2286 assert(size > (size_t)idnum, "should already have space");
2287 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2288 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2289 // cache size is stored in element[0], other elements offset by one
2290 jmeths[0] = (jmethodID)size;
2291 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2292
2293 // publish jmeths
2294 release_set_methods_jmethod_ids(jmeths);
2295 return new_id;
2296 }
2297 }
2298
2299 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2300 if (id == nullptr) {
2301 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2302 id = jmeths[idnum + 1];
2303 // Still null?
2304 if (id == nullptr) {
2305 return update_jmethod_id(jmeths, method, idnum);
2306 }
2307 }
2308 return id;
2309 }
2310
2311 void InstanceKlass::update_methods_jmethod_cache() {
2312 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2313 jmethodID* cache = _methods_jmethod_ids;
2314 if (cache != nullptr) {
2315 size_t size = idnum_allocated_count();
2316 size_t old_size = (size_t)cache[0];
2317 if (old_size < size + 1) {
2318 // Allocate a larger one and copy entries to the new one.
2319 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2320 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2321 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2322 // The cache size is stored in element[0]; the other elements are offset by one.
2323 new_cache[0] = (jmethodID)size;
2324
2325 for (int i = 1; i <= (int)old_size; i++) {
2326 new_cache[i] = cache[i];
2327 }
2328 _methods_jmethod_ids = new_cache;
2329 FREE_C_HEAP_ARRAY(jmethodID, cache);
2330 }
2331 }
2332 }
2333
2334 // Figure out how many jmethodIDs haven't been allocated, and make
2335 // sure space for them is pre-allocated. This makes getting all
2336 // method ids much, much faster with classes with more than 8
2337 // methods, and has a *substantial* effect on performance with jvmti
2338 // code that loads all jmethodIDs for all classes.
2339 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2340 int new_jmeths = 0;
2341 int length = methods()->length();
2342 for (int index = start_offset; index < length; index++) {
2343 Method* m = methods()->at(index);
2344 jmethodID id = m->find_jmethod_id_or_null();
2345 if (id == nullptr) {
2346 new_jmeths++;
2347 }
2348 }
2349 if (new_jmeths != 0) {
2350 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2351 }
2352 }
2353
2354 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2355 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2356 int idnum = method->method_idnum();
2357 jmethodID* jmeths = methods_jmethod_ids_acquire();
2358 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2359 }
2360
2361 inline DependencyContext InstanceKlass::dependencies() {
2362 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2363 return dep_context;
2364 }
2365
2366 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2367 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2368 }
2369
2370 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2371 dependencies().add_dependent_nmethod(nm);
2372 }
2373
2374 void InstanceKlass::clean_dependency_context() {
2375 dependencies().clean_unloading_dependents();
2376 }
2377
2378 #ifndef PRODUCT
2379 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2380 dependencies().print_dependent_nmethods(verbose);
2381 }
2382
2383 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2384 return dependencies().is_dependent_nmethod(nm);
2385 }
2386 #endif //PRODUCT
2387
2388 void InstanceKlass::clean_weak_instanceklass_links() {
2389 clean_implementors_list();
2390 clean_method_data();
2391 }
2392
2393 void InstanceKlass::clean_implementors_list() {
2394 assert(is_loader_alive(), "this klass should be live");
2395 if (is_interface()) {
2396 assert (ClassUnloading, "only called for ClassUnloading");
2397 for (;;) {
2398 // Use load_acquire due to competing with inserts
2399 InstanceKlass* volatile* iklass = adr_implementor();
2400 assert(iklass != nullptr, "Klass must not be null");
2401 InstanceKlass* impl = Atomic::load_acquire(iklass);
2402 if (impl != nullptr && !impl->is_loader_alive()) {
2403 // null this field, might be an unloaded instance klass or null
2404 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2405 // Successfully unlinking implementor.
2406 if (log_is_enabled(Trace, class, unload)) {
2407 ResourceMark rm;
2408 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2409 }
2410 return;
2411 }
2412 } else {
2413 return;
2414 }
2415 }
2416 }
2417 }
2418
2419 void InstanceKlass::clean_method_data() {
2420 for (int m = 0; m < methods()->length(); m++) {
2421 MethodData* mdo = methods()->at(m)->method_data();
2422 if (mdo != nullptr) {
2423 mdo->clean_method_data(/*always_clean*/false);
2424 }
2425 }
2426 }
2427
2428 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2429 Klass::metaspace_pointers_do(it);
2430
2431 if (log_is_enabled(Trace, cds)) {
2432 ResourceMark rm;
2433 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2434 }
2435
2436 it->push(&_annotations);
2437 it->push((Klass**)&_array_klasses);
2438 if (!is_rewritten()) {
2439 it->push(&_constants, MetaspaceClosure::_writable);
2440 } else {
2441 it->push(&_constants);
2442 }
2443 it->push(&_inner_classes);
2444 #if INCLUDE_JVMTI
2445 it->push(&_previous_versions);
2446 #endif
2447 #if INCLUDE_CDS
2448 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2449 // be rewritten during runtime (see Rewriter::rewrite_jsrs()). So setting the _methods to
2450 // be writable. The length check on the _methods is necessary because classes which
2451 // don't have any methods share the Universe::_the_empty_method_array which is in the RO region.
2452 if (_methods != nullptr && _methods->length() > 0 &&
2453 !can_be_verified_at_dumptime() && methods_contain_jsr_bytecode()) {
2454 // To handle jsr bytecode, new Method* maybe stored into _methods
2455 it->push(&_methods, MetaspaceClosure::_writable);
2456 } else {
2457 #endif
2458 it->push(&_methods);
2459 #if INCLUDE_CDS
2460 }
2461 #endif
2462 it->push(&_default_methods);
2463 it->push(&_local_interfaces);
2464 it->push(&_transitive_interfaces);
2465 it->push(&_method_ordering);
2466 if (!is_rewritten()) {
2467 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2468 } else {
2469 it->push(&_default_vtable_indices);
2470 }
2471
2472 it->push(&_fieldinfo_stream);
2473 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2474 it->push(&_fields_status, MetaspaceClosure::_writable);
2475
2476 if (itable_length() > 0) {
2477 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2478 int method_table_offset_in_words = ioe->offset()/wordSize;
2479 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2480
2481 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2482 / itableOffsetEntry::size();
2483
2484 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2485 if (ioe->interface_klass() != nullptr) {
2486 it->push(ioe->interface_klass_addr());
2487 itableMethodEntry* ime = ioe->first_method_entry(this);
2488 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2489 for (int index = 0; index < n; index ++) {
2490 it->push(ime[index].method_addr());
2491 }
2492 }
2493 }
2494 }
2495
2496 it->push(&_nest_members);
2497 it->push(&_permitted_subclasses);
2498 it->push(&_record_components);
2499 }
2500
2501 #if INCLUDE_CDS
2502 void InstanceKlass::remove_unshareable_info() {
2503
2504 if (is_linked()) {
2505 assert(can_be_verified_at_dumptime(), "must be");
2506 // Remember this so we can avoid walking the hierarchy at runtime.
2507 set_verified_at_dump_time();
2508 }
2509
2510 Klass::remove_unshareable_info();
2511
2512 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2513 // Classes are attempted to link during dumping and may fail,
2514 // but these classes are still in the dictionary and class list in CLD.
2515 // If the class has failed verification, there is nothing else to remove.
2516 return;
2517 }
2518
2519 // Reset to the 'allocated' state to prevent any premature accessing to
2520 // a shared class at runtime while the class is still being loaded and
2521 // restored. A class' init_state is set to 'loaded' at runtime when it's
2522 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2523 _init_state = allocated;
2524
2525 { // Otherwise this needs to take out the Compile_lock.
2526 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2527 init_implementor();
2528 }
2529
2530 // Call remove_unshareable_info() on other objects that belong to this class, except
2531 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2532 // ArchiveBuilder::make_klasses_shareable(),
2533
2534 for (int i = 0; i < methods()->length(); i++) {
2535 Method* m = methods()->at(i);
2536 m->remove_unshareable_info();
2537 }
2538
2539 // do array classes also.
2540 if (array_klasses() != nullptr) {
2541 array_klasses()->remove_unshareable_info();
2542 }
2543
2544 // These are not allocated from metaspace. They are safe to set to null.
2545 _source_debug_extension = nullptr;
2546 _dep_context = nullptr;
2547 _osr_nmethods_head = nullptr;
2548 #if INCLUDE_JVMTI
2549 _breakpoints = nullptr;
2550 _previous_versions = nullptr;
2551 _cached_class_file = nullptr;
2552 _jvmti_cached_class_field_map = nullptr;
2553 #endif
2554
2555 _init_thread = nullptr;
2556 _methods_jmethod_ids = nullptr;
2557 _jni_ids = nullptr;
2558 _oop_map_cache = nullptr;
2559 // clear _nest_host to ensure re-load at runtime
2560 _nest_host = nullptr;
2561 init_shared_package_entry();
2562 _dep_context_last_cleaned = 0;
2563
2564 remove_unshareable_flags();
2565 }
2566
2567 void InstanceKlass::remove_unshareable_flags() {
2568 // clear all the flags/stats that shouldn't be in the archived version
2569 assert(!is_scratch_class(), "must be");
2570 assert(!has_been_redefined(), "must be");
2571 #if INCLUDE_JVMTI
2572 set_is_being_redefined(false);
2573 #endif
2574 set_has_resolved_methods(false);
2575 }
2576
2577 void InstanceKlass::remove_java_mirror() {
2578 Klass::remove_java_mirror();
2579
2580 // do array classes also.
2581 if (array_klasses() != nullptr) {
2582 array_klasses()->remove_java_mirror();
2583 }
2584 }
2585
2586 void InstanceKlass::init_shared_package_entry() {
2587 assert(CDSConfig::is_dumping_archive(), "must be");
2588 #if !INCLUDE_CDS_JAVA_HEAP
2589 _package_entry = nullptr;
2590 #else
2591 if (CDSConfig::is_dumping_full_module_graph()) {
2592 if (is_shared_unregistered_class()) {
2593 _package_entry = nullptr;
2594 } else {
2595 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2596 }
2597 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2598 CDSConfig::is_using_full_module_graph() &&
2599 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2600 // _package_entry is an archived package in the base archive. Leave it as is.
2601 } else {
2602 _package_entry = nullptr;
2603 }
2604 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2605 #endif
2606 }
2607
2608 void InstanceKlass::compute_has_loops_flag_for_methods() {
2609 Array<Method*>* methods = this->methods();
2610 for (int index = 0; index < methods->length(); ++index) {
2611 Method* m = methods->at(index);
2612 if (!m->is_overpass()) { // work around JDK-8305771
2613 m->compute_has_loops_flag();
2614 }
2615 }
2616 }
2617
2618 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2619 PackageEntry* pkg_entry, TRAPS) {
2620 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2621 // before the InstanceKlass is added to the SystemDictionary. Make
2622 // sure the current state is <loaded.
2623 assert(!is_loaded(), "invalid init state");
2624 assert(!shared_loading_failed(), "Must not try to load failed class again");
2625 set_package(loader_data, pkg_entry, CHECK);
2626 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2627
2628 Array<Method*>* methods = this->methods();
2629 int num_methods = methods->length();
2630 for (int index = 0; index < num_methods; ++index) {
2631 methods->at(index)->restore_unshareable_info(CHECK);
2632 }
2633 #if INCLUDE_JVMTI
2634 if (JvmtiExport::has_redefined_a_class()) {
2635 // Reinitialize vtable because RedefineClasses may have changed some
2636 // entries in this vtable for super classes so the CDS vtable might
2637 // point to old or obsolete entries. RedefineClasses doesn't fix up
2638 // vtables in the shared system dictionary, only the main one.
2639 // It also redefines the itable too so fix that too.
2640 // First fix any default methods that point to a super class that may
2641 // have been redefined.
2642 bool trace_name_printed = false;
2643 adjust_default_methods(&trace_name_printed);
2644 vtable().initialize_vtable();
2645 itable().initialize_itable();
2646 }
2647 #endif
2648
2649 // restore constant pool resolved references
2650 constants()->restore_unshareable_info(CHECK);
2651
2652 if (array_klasses() != nullptr) {
2653 // To get a consistent list of classes we need MultiArray_lock to ensure
2654 // array classes aren't observed while they are being restored.
2655 RecursiveLocker rl(MultiArray_lock, THREAD);
2656 assert(this == array_klasses()->bottom_klass(), "sanity");
2657 // Array classes have null protection domain.
2658 // --> see ArrayKlass::complete_create_array_klass()
2659 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2660 }
2661
2662 // Initialize @ValueBased class annotation
2663 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation()) {
2664 set_is_value_based();
2665 }
2666 }
2667
2668 // Check if a class or any of its supertypes has a version older than 50.
2669 // CDS will not perform verification of old classes during dump time because
2670 // without changing the old verifier, the verification constraint cannot be
2671 // retrieved during dump time.
2672 // Verification of archived old classes will be performed during run time.
2673 bool InstanceKlass::can_be_verified_at_dumptime() const {
2674 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2675 // This is a class that was dumped into the base archive, so we know
2676 // it was verified at dump time.
2677 return true;
2678 }
2679 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2680 return false;
2681 }
2682 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2683 return false;
2684 }
2685 Array<InstanceKlass*>* interfaces = local_interfaces();
2686 int len = interfaces->length();
2687 for (int i = 0; i < len; i++) {
2688 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2689 return false;
2690 }
2691 }
2692 return true;
2693 }
2694
2695 bool InstanceKlass::methods_contain_jsr_bytecode() const {
2696 Thread* thread = Thread::current();
2697 for (int i = 0; i < _methods->length(); i++) {
2698 methodHandle m(thread, _methods->at(i));
2699 BytecodeStream bcs(m);
2700 while (!bcs.is_last_bytecode()) {
2701 Bytecodes::Code opcode = bcs.next();
2702 if (opcode == Bytecodes::_jsr || opcode == Bytecodes::_jsr_w) {
2703 return true;
2704 }
2705 }
2706 }
2707 return false;
2708 }
2709 #endif // INCLUDE_CDS
2710
2711 #if INCLUDE_JVMTI
2712 static void clear_all_breakpoints(Method* m) {
2713 m->clear_all_breakpoints();
2714 }
2715 #endif
2716
2717 void InstanceKlass::unload_class(InstanceKlass* ik) {
2718 // Release dependencies.
2719 ik->dependencies().remove_all_dependents();
2720
2721 // notify the debugger
2722 if (JvmtiExport::should_post_class_unload()) {
2723 JvmtiExport::post_class_unload(ik);
2724 }
2725
2726 // notify ClassLoadingService of class unload
2727 ClassLoadingService::notify_class_unloaded(ik);
2728
2729 SystemDictionaryShared::handle_class_unloading(ik);
2730
2731 if (log_is_enabled(Info, class, unload)) {
2732 ResourceMark rm;
2733 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2734 }
2735
2736 Events::log_class_unloading(Thread::current(), ik);
2737
2738 #if INCLUDE_JFR
2739 assert(ik != nullptr, "invariant");
2740 EventClassUnload event;
2741 event.set_unloadedClass(ik);
2742 event.set_definingClassLoader(ik->class_loader_data());
2743 event.commit();
2744 #endif
2745 }
2746
2747 static void method_release_C_heap_structures(Method* m) {
2748 m->release_C_heap_structures();
2749 }
2750
2751 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2752 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2753 // Clean up C heap
2754 Klass::release_C_heap_structures();
2755
2756 // Deallocate and call destructors for MDO mutexes
2757 if (release_sub_metadata) {
2758 methods_do(method_release_C_heap_structures);
2759 }
2760
2761 // Deallocate oop map cache
2762 if (_oop_map_cache != nullptr) {
2763 delete _oop_map_cache;
2764 _oop_map_cache = nullptr;
2765 }
2766
2767 // Deallocate JNI identifiers for jfieldIDs
2768 JNIid::deallocate(jni_ids());
2769 set_jni_ids(nullptr);
2770
2771 jmethodID* jmeths = methods_jmethod_ids_acquire();
2772 if (jmeths != nullptr) {
2773 release_set_methods_jmethod_ids(nullptr);
2774 FreeHeap(jmeths);
2775 }
2776
2777 assert(_dep_context == nullptr,
2778 "dependencies should already be cleaned");
2779
2780 #if INCLUDE_JVMTI
2781 // Deallocate breakpoint records
2782 if (breakpoints() != 0x0) {
2783 methods_do(clear_all_breakpoints);
2784 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2785 }
2786
2787 // deallocate the cached class file
2788 if (_cached_class_file != nullptr) {
2789 os::free(_cached_class_file);
2790 _cached_class_file = nullptr;
2791 }
2792 #endif
2793
2794 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2795
2796 if (release_sub_metadata) {
2797 constants()->release_C_heap_structures();
2798 }
2799 }
2800
2801 // The constant pool is on stack if any of the methods are executing or
2802 // referenced by handles.
2803 bool InstanceKlass::on_stack() const {
2804 return _constants->on_stack();
2805 }
2806
2807 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2808 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2809 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2810
2811 // minor and major version numbers of class file
2812 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2813 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2814 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2815 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2816
2817 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2818 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2819 if (ik->constants()->version() == version) {
2820 return ik;
2821 }
2822 }
2823 return nullptr;
2824 }
2825
2826 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2827 if (array == nullptr) {
2828 _source_debug_extension = nullptr;
2829 } else {
2830 // Adding one to the attribute length in order to store a null terminator
2831 // character could cause an overflow because the attribute length is
2832 // already coded with an u4 in the classfile, but in practice, it's
2833 // unlikely to happen.
2834 assert((length+1) > length, "Overflow checking");
2835 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2836 for (int i = 0; i < length; i++) {
2837 sde[i] = array[i];
2838 }
2839 sde[length] = '\0';
2840 _source_debug_extension = sde;
2841 }
2842 }
2843
2844 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
2845 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
2846 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
2847
2848 const char* InstanceKlass::signature_name() const {
2849
2850 // Get the internal name as a c string
2851 const char* src = (const char*) (name()->as_C_string());
2852 const int src_length = (int)strlen(src);
2853
2854 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2855
2856 // Add L as type indicator
2857 int dest_index = 0;
2858 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2859
2860 // Add the actual class name
2861 for (int src_index = 0; src_index < src_length; ) {
2862 dest[dest_index++] = src[src_index++];
2863 }
2864
2865 if (is_hidden()) { // Replace the last '+' with a '.'.
2866 for (int index = (int)src_length; index > 0; index--) {
2867 if (dest[index] == '+') {
2868 dest[index] = JVM_SIGNATURE_DOT;
2869 break;
2870 }
2871 }
2872 }
2873
2874 // Add the semicolon and the null
2875 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2876 dest[dest_index] = '\0';
2877 return dest;
2878 }
2879
2880 ModuleEntry* InstanceKlass::module() const {
2881 if (is_hidden() &&
2882 in_unnamed_package() &&
2883 class_loader_data()->has_class_mirror_holder()) {
2884 // For a non-strong hidden class defined to an unnamed package,
2885 // its (class held) CLD will not have an unnamed module created for it.
2886 // Two choices to find the correct ModuleEntry:
2887 // 1. If hidden class is within a nest, use nest host's module
2888 // 2. Find the unnamed module off from the class loader
2889 // For now option #2 is used since a nest host is not set until
2890 // after the instance class is created in jvm_lookup_define_class().
2891 if (class_loader_data()->is_boot_class_loader_data()) {
2892 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2893 } else {
2894 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2895 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2896 return java_lang_Module::module_entry(module);
2897 }
2898 }
2899
2900 // Class is in a named package
2901 if (!in_unnamed_package()) {
2902 return _package_entry->module();
2903 }
2904
2905 // Class is in an unnamed package, return its loader's unnamed module
2906 return class_loader_data()->unnamed_module();
2907 }
2908
2909 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
2910
2911 // ensure java/ packages only loaded by boot or platform builtin loaders
2912 // not needed for shared class since CDS does not archive prohibited classes.
2913 if (!is_shared()) {
2914 check_prohibited_package(name(), loader_data, CHECK);
2915 }
2916
2917 if (is_shared() && _package_entry != nullptr) {
2918 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
2919 // we can use the saved package
2920 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
2921 return;
2922 } else {
2923 _package_entry = nullptr;
2924 }
2925 }
2926
2927 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
2928 // it returns, so we need to decrement it when the current function exits.
2929 TempNewSymbol from_class_name =
2930 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
2931
2932 Symbol* pkg_name;
2933 if (pkg_entry != nullptr) {
2934 pkg_name = pkg_entry->name();
2935 } else {
2936 pkg_name = from_class_name;
2937 }
2938
2939 if (pkg_name != nullptr && loader_data != nullptr) {
2940
2941 // Find in class loader's package entry table.
2942 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
2943
2944 // If the package name is not found in the loader's package
2945 // entry table, it is an indication that the package has not
2946 // been defined. Consider it defined within the unnamed module.
2947 if (_package_entry == nullptr) {
2948
2949 if (!ModuleEntryTable::javabase_defined()) {
2950 // Before java.base is defined during bootstrapping, define all packages in
2951 // the java.base module. If a non-java.base package is erroneously placed
2952 // in the java.base module it will be caught later when java.base
2953 // is defined by ModuleEntryTable::verify_javabase_packages check.
2954 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
2955 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2956 } else {
2957 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
2958 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
2959 }
2960
2961 // A package should have been successfully created
2962 DEBUG_ONLY(ResourceMark rm(THREAD));
2963 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
2964 name()->as_C_string(), loader_data->loader_name_and_id());
2965 }
2966
2967 if (log_is_enabled(Debug, module)) {
2968 ResourceMark rm(THREAD);
2969 ModuleEntry* m = _package_entry->module();
2970 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2971 external_name(),
2972 pkg_name->as_C_string(),
2973 loader_data->loader_name_and_id(),
2974 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2975 }
2976 } else {
2977 ResourceMark rm(THREAD);
2978 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2979 external_name(),
2980 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
2981 UNNAMED_MODULE);
2982 }
2983 }
2984
2985 // Function set_classpath_index ensures that for a non-null _package_entry
2986 // of the InstanceKlass, the entry is in the boot loader's package entry table.
2987 // It then sets the classpath_index in the package entry record.
2988 //
2989 // The classpath_index field is used to find the entry on the boot loader class
2990 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
2991 // in an unnamed module. It is also used to indicate (for all packages whose
2992 // classes are loaded by the boot loader) that at least one of the package's
2993 // classes has been loaded.
2994 void InstanceKlass::set_classpath_index(s2 path_index) {
2995 if (_package_entry != nullptr) {
2996 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
2997 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
2998 assert(path_index != -1, "Unexpected classpath_index");
2999 _package_entry->set_classpath_index(path_index);
3000 }
3001 }
3002
3003 // different versions of is_same_class_package
3004
3005 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3006 oop classloader1 = this->class_loader();
3007 PackageEntry* classpkg1 = this->package();
3008 if (class2->is_objArray_klass()) {
3009 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3010 }
3011
3012 oop classloader2;
3013 PackageEntry* classpkg2;
3014 if (class2->is_instance_klass()) {
3015 classloader2 = class2->class_loader();
3016 classpkg2 = class2->package();
3017 } else {
3018 assert(class2->is_typeArray_klass(), "should be type array");
3019 classloader2 = nullptr;
3020 classpkg2 = nullptr;
3021 }
3022
3023 // Same package is determined by comparing class loader
3024 // and package entries. Both must be the same. This rule
3025 // applies even to classes that are defined in the unnamed
3026 // package, they still must have the same class loader.
3027 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3028 return true;
3029 }
3030
3031 return false;
3032 }
3033
3034 // return true if this class and other_class are in the same package. Classloader
3035 // and classname information is enough to determine a class's package
3036 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3037 const Symbol* other_class_name) const {
3038 if (class_loader() != other_class_loader) {
3039 return false;
3040 }
3041 if (name()->fast_compare(other_class_name) == 0) {
3042 return true;
3043 }
3044
3045 {
3046 ResourceMark rm;
3047
3048 bool bad_class_name = false;
3049 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3050 if (bad_class_name) {
3051 return false;
3052 }
3053 // Check that package_from_class_name() returns null, not "", if there is no package.
3054 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3055
3056 const Symbol* const this_package_name =
3057 this->package() != nullptr ? this->package()->name() : nullptr;
3058
3059 if (this_package_name == nullptr || other_pkg == nullptr) {
3060 // One of the two doesn't have a package. Only return true if the other
3061 // one also doesn't have a package.
3062 return this_package_name == other_pkg;
3063 }
3064
3065 // Check if package is identical
3066 return this_package_name->fast_compare(other_pkg) == 0;
3067 }
3068 }
3069
3070 static bool is_prohibited_package_slow(Symbol* class_name) {
3071 // Caller has ResourceMark
3072 int length;
3073 jchar* unicode = class_name->as_unicode(length);
3074 return (length >= 5 &&
3075 unicode[0] == 'j' &&
3076 unicode[1] == 'a' &&
3077 unicode[2] == 'v' &&
3078 unicode[3] == 'a' &&
3079 unicode[4] == '/');
3080 }
3081
3082 // Only boot and platform class loaders can define classes in "java/" packages.
3083 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3084 ClassLoaderData* loader_data,
3085 TRAPS) {
3086 if (!loader_data->is_boot_class_loader_data() &&
3087 !loader_data->is_platform_class_loader_data() &&
3088 class_name != nullptr && class_name->utf8_length() >= 5) {
3089 ResourceMark rm(THREAD);
3090 bool prohibited;
3091 const u1* base = class_name->base();
3092 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3093 prohibited = is_prohibited_package_slow(class_name);
3094 } else {
3095 char* name = class_name->as_C_string();
3096 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3097 }
3098 if (prohibited) {
3099 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3100 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3101 char* name = pkg_name->as_C_string();
3102 const char* class_loader_name = loader_data->loader_name_and_id();
3103 StringUtils::replace_no_expand(name, "/", ".");
3104 const char* msg_text1 = "Class loader (instance of): ";
3105 const char* msg_text2 = " tried to load prohibited package name: ";
3106 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3107 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3108 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3109 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3110 }
3111 }
3112 return;
3113 }
3114
3115 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3116 constantPoolHandle i_cp(THREAD, constants());
3117 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3118 int ioff = iter.inner_class_info_index();
3119 if (ioff != 0) {
3120 // Check to see if the name matches the class we're looking for
3121 // before attempting to find the class.
3122 if (i_cp->klass_name_at_matches(this, ioff)) {
3123 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3124 if (this == inner_klass) {
3125 *ooff = iter.outer_class_info_index();
3126 *noff = iter.inner_name_index();
3127 return true;
3128 }
3129 }
3130 }
3131 }
3132 return false;
3133 }
3134
3135 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3136 InstanceKlass* outer_klass = nullptr;
3137 *inner_is_member = false;
3138 int ooff = 0, noff = 0;
3139 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3140 if (has_inner_classes_attr) {
3141 constantPoolHandle i_cp(THREAD, constants());
3142 if (ooff != 0) {
3143 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3144 if (!ok->is_instance_klass()) {
3145 // If the outer class is not an instance klass then it cannot have
3146 // declared any inner classes.
3147 ResourceMark rm(THREAD);
3148 Exceptions::fthrow(
3149 THREAD_AND_LOCATION,
3150 vmSymbols::java_lang_IncompatibleClassChangeError(),
3151 "%s and %s disagree on InnerClasses attribute",
3152 ok->external_name(),
3153 external_name());
3154 return nullptr;
3155 }
3156 outer_klass = InstanceKlass::cast(ok);
3157 *inner_is_member = true;
3158 }
3159 if (nullptr == outer_klass) {
3160 // It may be a local class; try for that.
3161 int encl_method_class_idx = enclosing_method_class_index();
3162 if (encl_method_class_idx != 0) {
3163 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3164 outer_klass = InstanceKlass::cast(ok);
3165 *inner_is_member = false;
3166 }
3167 }
3168 }
3169
3170 // If no inner class attribute found for this class.
3171 if (nullptr == outer_klass) return nullptr;
3172
3173 // Throws an exception if outer klass has not declared k as an inner klass
3174 // We need evidence that each klass knows about the other, or else
3175 // the system could allow a spoof of an inner class to gain access rights.
3176 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3177 return outer_klass;
3178 }
3179
3180 jint InstanceKlass::compute_modifier_flags() const {
3181 jint access = access_flags().as_int();
3182
3183 // But check if it happens to be member class.
3184 InnerClassesIterator iter(this);
3185 for (; !iter.done(); iter.next()) {
3186 int ioff = iter.inner_class_info_index();
3187 // Inner class attribute can be zero, skip it.
3188 // Strange but true: JVM spec. allows null inner class refs.
3189 if (ioff == 0) continue;
3190
3191 // only look at classes that are already loaded
3192 // since we are looking for the flags for our self.
3193 Symbol* inner_name = constants()->klass_name_at(ioff);
3194 if (name() == inner_name) {
3195 // This is really a member class.
3196 access = iter.inner_access_flags();
3197 break;
3198 }
3199 }
3200 // Remember to strip ACC_SUPER bit
3201 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3202 }
3203
3204 jint InstanceKlass::jvmti_class_status() const {
3205 jint result = 0;
3206
3207 if (is_linked()) {
3208 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3209 }
3210
3211 if (is_initialized()) {
3212 assert(is_linked(), "Class status is not consistent");
3213 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3214 }
3215 if (is_in_error_state()) {
3216 result |= JVMTI_CLASS_STATUS_ERROR;
3217 }
3218 return result;
3219 }
3220
3221 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3222 bool implements_interface; // initialized by method_at_itable_or_null
3223 Method* m = method_at_itable_or_null(holder, index,
3224 implements_interface); // out parameter
3225 if (m != nullptr) {
3226 assert(implements_interface, "sanity");
3227 return m;
3228 } else if (implements_interface) {
3229 // Throw AbstractMethodError since corresponding itable slot is empty.
3230 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3231 } else {
3232 // If the interface isn't implemented by the receiver class,
3233 // the VM should throw IncompatibleClassChangeError.
3234 ResourceMark rm(THREAD);
3235 stringStream ss;
3236 bool same_module = (module() == holder->module());
3237 ss.print("Receiver class %s does not implement "
3238 "the interface %s defining the method to be called "
3239 "(%s%s%s)",
3240 external_name(), holder->external_name(),
3241 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3242 (same_module) ? "" : "; ",
3243 (same_module) ? "" : holder->class_in_module_of_loader());
3244 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3245 }
3246 }
3247
3248 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3249 klassItable itable(this);
3250 for (int i = 0; i < itable.size_offset_table(); i++) {
3251 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3252 if (offset_entry->interface_klass() == holder) {
3253 implements_interface = true;
3254 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3255 Method* m = ime[index].method();
3256 return m;
3257 }
3258 }
3259 implements_interface = false;
3260 return nullptr; // offset entry not found
3261 }
3262
3263 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3264 assert(is_linked(), "required");
3265 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3266 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3267
3268 int vtable_index = Method::invalid_vtable_index;
3269 Symbol* name = intf_method->name();
3270 Symbol* signature = intf_method->signature();
3271
3272 // First check in default method array
3273 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3274 int index = find_method_index(default_methods(),
3275 name, signature,
3276 Klass::OverpassLookupMode::find,
3277 Klass::StaticLookupMode::find,
3278 Klass::PrivateLookupMode::find);
3279 if (index >= 0) {
3280 vtable_index = default_vtable_indices()->at(index);
3281 }
3282 }
3283 if (vtable_index == Method::invalid_vtable_index) {
3284 // get vtable_index for miranda methods
3285 klassVtable vt = vtable();
3286 vtable_index = vt.index_of_miranda(name, signature);
3287 }
3288 return vtable_index;
3289 }
3290
3291 #if INCLUDE_JVMTI
3292 // update default_methods for redefineclasses for methods that are
3293 // not yet in the vtable due to concurrent subclass define and superinterface
3294 // redefinition
3295 // Note: those in the vtable, should have been updated via adjust_method_entries
3296 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3297 // search the default_methods for uses of either obsolete or EMCP methods
3298 if (default_methods() != nullptr) {
3299 for (int index = 0; index < default_methods()->length(); index ++) {
3300 Method* old_method = default_methods()->at(index);
3301 if (old_method == nullptr || !old_method->is_old()) {
3302 continue; // skip uninteresting entries
3303 }
3304 assert(!old_method->is_deleted(), "default methods may not be deleted");
3305 Method* new_method = old_method->get_new_method();
3306 default_methods()->at_put(index, new_method);
3307
3308 if (log_is_enabled(Info, redefine, class, update)) {
3309 ResourceMark rm;
3310 if (!(*trace_name_printed)) {
3311 log_info(redefine, class, update)
3312 ("adjust: klassname=%s default methods from name=%s",
3313 external_name(), old_method->method_holder()->external_name());
3314 *trace_name_printed = true;
3315 }
3316 log_debug(redefine, class, update, vtables)
3317 ("default method update: %s(%s) ",
3318 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3319 }
3320 }
3321 }
3322 }
3323 #endif // INCLUDE_JVMTI
3324
3325 // On-stack replacement stuff
3326 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3327 assert_lock_strong(NMethodState_lock);
3328 #ifndef PRODUCT
3329 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3330 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3331 "redundant OSR recompilation detected. memory leak in CodeCache!");
3332 #endif
3333 // only one compilation can be active
3334 assert(n->is_osr_method(), "wrong kind of nmethod");
3335 n->set_osr_link(osr_nmethods_head());
3336 set_osr_nmethods_head(n);
3337 // Raise the highest osr level if necessary
3338 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3339
3340 // Get rid of the osr methods for the same bci that have lower levels.
3341 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3342 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3343 if (inv != nullptr && inv->is_in_use()) {
3344 inv->make_not_entrant();
3345 }
3346 }
3347 }
3348
3349 // Remove osr nmethod from the list. Return true if found and removed.
3350 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3351 // This is a short non-blocking critical region, so the no safepoint check is ok.
3352 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3353 assert(n->is_osr_method(), "wrong kind of nmethod");
3354 nmethod* last = nullptr;
3355 nmethod* cur = osr_nmethods_head();
3356 int max_level = CompLevel_none; // Find the max comp level excluding n
3357 Method* m = n->method();
3358 // Search for match
3359 bool found = false;
3360 while(cur != nullptr && cur != n) {
3361 if (m == cur->method()) {
3362 // Find max level before n
3363 max_level = MAX2(max_level, cur->comp_level());
3364 }
3365 last = cur;
3366 cur = cur->osr_link();
3367 }
3368 nmethod* next = nullptr;
3369 if (cur == n) {
3370 found = true;
3371 next = cur->osr_link();
3372 if (last == nullptr) {
3373 // Remove first element
3374 set_osr_nmethods_head(next);
3375 } else {
3376 last->set_osr_link(next);
3377 }
3378 }
3379 n->set_osr_link(nullptr);
3380 cur = next;
3381 while (cur != nullptr) {
3382 // Find max level after n
3383 if (m == cur->method()) {
3384 max_level = MAX2(max_level, cur->comp_level());
3385 }
3386 cur = cur->osr_link();
3387 }
3388 m->set_highest_osr_comp_level(max_level);
3389 return found;
3390 }
3391
3392 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3393 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3394 nmethod* osr = osr_nmethods_head();
3395 int found = 0;
3396 while (osr != nullptr) {
3397 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3398 if (osr->method() == m) {
3399 deopt_scope->mark(osr);
3400 found++;
3401 }
3402 osr = osr->osr_link();
3403 }
3404 return found;
3405 }
3406
3407 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3408 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3409 nmethod* osr = osr_nmethods_head();
3410 nmethod* best = nullptr;
3411 while (osr != nullptr) {
3412 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3413 // There can be a time when a c1 osr method exists but we are waiting
3414 // for a c2 version. When c2 completes its osr nmethod we will trash
3415 // the c1 version and only be able to find the c2 version. However
3416 // while we overflow in the c1 code at back branches we don't want to
3417 // try and switch to the same code as we are already running
3418
3419 if (osr->method() == m &&
3420 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3421 if (match_level) {
3422 if (osr->comp_level() == comp_level) {
3423 // Found a match - return it.
3424 return osr;
3425 }
3426 } else {
3427 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3428 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3429 // Found the best possible - return it.
3430 return osr;
3431 }
3432 best = osr;
3433 }
3434 }
3435 }
3436 osr = osr->osr_link();
3437 }
3438
3439 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3440 if (best != nullptr && best->comp_level() >= comp_level) {
3441 return best;
3442 }
3443 return nullptr;
3444 }
3445
3446 // -----------------------------------------------------------------------------------------------------
3447 // Printing
3448
3449 #define BULLET " - "
3450
3451 static const char* state_names[] = {
3452 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3453 };
3454
3455 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3456 for (int i = 0; i < len; i++) {
3457 intptr_t e = start[i];
3458 st->print("%d : " INTPTR_FORMAT, i, e);
3459 if (MetaspaceObj::is_valid((Metadata*)e)) {
3460 st->print(" ");
3461 ((Metadata*)e)->print_value_on(st);
3462 }
3463 st->cr();
3464 }
3465 }
3466
3467 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3468 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3469 }
3470
3471 const char* InstanceKlass::init_state_name() const {
3472 return state_names[init_state()];
3473 }
3474
3475 void InstanceKlass::print_on(outputStream* st) const {
3476 assert(is_klass(), "must be klass");
3477 Klass::print_on(st);
3478
3479 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3480 st->print(BULLET"klass size: %d", size()); st->cr();
3481 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3482 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3483 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3484 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3485 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3486 st->print(BULLET"sub: ");
3487 Klass* sub = subklass();
3488 int n;
3489 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3490 if (n < MaxSubklassPrintSize) {
3491 sub->print_value_on(st);
3492 st->print(" ");
3493 }
3494 }
3495 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3496 st->cr();
3497
3498 if (is_interface()) {
3499 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3500 if (nof_implementors() == 1) {
3501 st->print_cr(BULLET"implementor: ");
3502 st->print(" ");
3503 implementor()->print_value_on(st);
3504 st->cr();
3505 }
3506 }
3507
3508 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3509 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3510 if (Verbose || WizardMode) {
3511 Array<Method*>* method_array = methods();
3512 for (int i = 0; i < method_array->length(); i++) {
3513 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3514 }
3515 }
3516 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3517 if (default_methods() != nullptr) {
3518 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3519 if (Verbose) {
3520 Array<Method*>* method_array = default_methods();
3521 for (int i = 0; i < method_array->length(); i++) {
3522 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3523 }
3524 }
3525 }
3526 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3527 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3528 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3529
3530 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3531 if (UseSecondarySupersTable) {
3532 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3533 st->print(BULLET"bitmap: " UINTX_FORMAT_X_0, _bitmap); st->cr();
3534 }
3535 if (secondary_supers() != nullptr) {
3536 if (Verbose) {
3537 bool is_hashed = UseSecondarySupersTable && (_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3538 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3539 for (int i = 0; i < _secondary_supers->length(); i++) {
3540 ResourceMark rm; // for external_name()
3541 Klass* secondary_super = _secondary_supers->at(i);
3542 st->print(BULLET"%2d:", i);
3543 if (is_hashed) {
3544 int home_slot = compute_home_slot(secondary_super, _bitmap);
3545 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3546 st->print(" dist:%02d:", distance);
3547 }
3548 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3549 }
3550 }
3551 }
3552 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3553
3554 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3555 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3556 if (source_debug_extension() != nullptr) {
3557 st->print(BULLET"source debug extension: ");
3558 st->print("%s", source_debug_extension());
3559 st->cr();
3560 }
3561 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3562 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3563 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3564 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3565 {
3566 bool have_pv = false;
3567 // previous versions are linked together through the InstanceKlass
3568 for (InstanceKlass* pv_node = previous_versions();
3569 pv_node != nullptr;
3570 pv_node = pv_node->previous_versions()) {
3571 if (!have_pv)
3572 st->print(BULLET"previous version: ");
3573 have_pv = true;
3574 pv_node->constants()->print_value_on(st);
3575 }
3576 if (have_pv) st->cr();
3577 }
3578
3579 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3580 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3581 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3582 print_on_maybe_null(st, BULLET"record components: ", record_components());
3583 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3584 if (java_mirror() != nullptr) {
3585 st->print(BULLET"java mirror: ");
3586 java_mirror()->print_value_on(st);
3587 st->cr();
3588 } else {
3589 st->print_cr(BULLET"java mirror: null");
3590 }
3591 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3592 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3593 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3594 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3595 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3596
3597 FieldPrinter print_static_field(st);
3598 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3599 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3600 FieldPrinter print_nonstatic_field(st);
3601 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3602 ik->print_nonstatic_fields(&print_nonstatic_field);
3603
3604 st->print(BULLET"non-static oop maps: ");
3605 OopMapBlock* map = start_of_nonstatic_oop_maps();
3606 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3607 while (map < end_map) {
3608 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3609 map++;
3610 }
3611 st->cr();
3612 }
3613
3614 void InstanceKlass::print_value_on(outputStream* st) const {
3615 assert(is_klass(), "must be klass");
3616 if (Verbose || WizardMode) access_flags().print_on(st);
3617 name()->print_value_on(st);
3618 }
3619
3620 void FieldPrinter::do_field(fieldDescriptor* fd) {
3621 _st->print(BULLET);
3622 if (_obj == nullptr) {
3623 fd->print_on(_st);
3624 _st->cr();
3625 } else {
3626 fd->print_on_for(_st, _obj);
3627 _st->cr();
3628 }
3629 }
3630
3631
3632 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3633 Klass::oop_print_on(obj, st);
3634
3635 if (this == vmClasses::String_klass()) {
3636 typeArrayOop value = java_lang_String::value(obj);
3637 juint length = java_lang_String::length(obj);
3638 if (value != nullptr &&
3639 value->is_typeArray() &&
3640 length <= (juint) value->length()) {
3641 st->print(BULLET"string: ");
3642 java_lang_String::print(obj, st);
3643 st->cr();
3644 }
3645 }
3646
3647 st->print_cr(BULLET"---- fields (total size " SIZE_FORMAT " words):", oop_size(obj));
3648 FieldPrinter print_field(st, obj);
3649 print_nonstatic_fields(&print_field);
3650
3651 if (this == vmClasses::Class_klass()) {
3652 st->print(BULLET"signature: ");
3653 java_lang_Class::print_signature(obj, st);
3654 st->cr();
3655 Klass* real_klass = java_lang_Class::as_Klass(obj);
3656 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3657 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3658 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3659 }
3660 } else if (this == vmClasses::MethodType_klass()) {
3661 st->print(BULLET"signature: ");
3662 java_lang_invoke_MethodType::print_signature(obj, st);
3663 st->cr();
3664 }
3665 }
3666
3667 #ifndef PRODUCT
3668
3669 bool InstanceKlass::verify_itable_index(int i) {
3670 int method_count = klassItable::method_count_for_interface(this);
3671 assert(i >= 0 && i < method_count, "index out of bounds");
3672 return true;
3673 }
3674
3675 #endif //PRODUCT
3676
3677 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3678 st->print("a ");
3679 name()->print_value_on(st);
3680 obj->print_address_on(st);
3681 if (this == vmClasses::String_klass()
3682 && java_lang_String::value(obj) != nullptr) {
3683 ResourceMark rm;
3684 int len = java_lang_String::length(obj);
3685 int plen = (len < 24 ? len : 12);
3686 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3687 st->print(" = \"%s\"", str);
3688 if (len > plen)
3689 st->print("...[%d]", len);
3690 } else if (this == vmClasses::Class_klass()) {
3691 Klass* k = java_lang_Class::as_Klass(obj);
3692 st->print(" = ");
3693 if (k != nullptr) {
3694 k->print_value_on(st);
3695 } else {
3696 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3697 st->print("%s", tname ? tname : "type?");
3698 }
3699 } else if (this == vmClasses::MethodType_klass()) {
3700 st->print(" = ");
3701 java_lang_invoke_MethodType::print_signature(obj, st);
3702 } else if (java_lang_boxing_object::is_instance(obj)) {
3703 st->print(" = ");
3704 java_lang_boxing_object::print(obj, st);
3705 } else if (this == vmClasses::LambdaForm_klass()) {
3706 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3707 if (vmentry != nullptr) {
3708 st->print(" => ");
3709 vmentry->print_value_on(st);
3710 }
3711 } else if (this == vmClasses::MemberName_klass()) {
3712 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3713 if (vmtarget != nullptr) {
3714 st->print(" = ");
3715 vmtarget->print_value_on(st);
3716 } else {
3717 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3718 oop name = java_lang_invoke_MemberName::name(obj);
3719 if (clazz != nullptr) {
3720 clazz->print_value_on(st);
3721 } else {
3722 st->print("null");
3723 }
3724 st->print(".");
3725 if (name != nullptr) {
3726 name->print_value_on(st);
3727 } else {
3728 st->print("null");
3729 }
3730 }
3731 }
3732 }
3733
3734 const char* InstanceKlass::internal_name() const {
3735 return external_name();
3736 }
3737
3738 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3739 const ModuleEntry* module_entry,
3740 const ClassFileStream* cfs) const {
3741
3742 if (ClassListWriter::is_enabled()) {
3743 ClassListWriter::write(this, cfs);
3744 }
3745
3746 print_class_load_helper(loader_data, module_entry, cfs);
3747 print_class_load_cause_logging();
3748 }
3749
3750 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3751 const ModuleEntry* module_entry,
3752 const ClassFileStream* cfs) const {
3753
3754 if (!log_is_enabled(Info, class, load)) {
3755 return;
3756 }
3757
3758 ResourceMark rm;
3759 LogMessage(class, load) msg;
3760 stringStream info_stream;
3761
3762 // Name and class hierarchy info
3763 info_stream.print("%s", external_name());
3764
3765 // Source
3766 if (cfs != nullptr) {
3767 if (cfs->source() != nullptr) {
3768 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3769 if (module_name != nullptr) {
3770 // When the boot loader created the stream, it didn't know the module name
3771 // yet. Let's format it now.
3772 if (cfs->from_boot_loader_modules_image()) {
3773 info_stream.print(" source: jrt:/%s", module_name);
3774 } else {
3775 info_stream.print(" source: %s", cfs->source());
3776 }
3777 } else {
3778 info_stream.print(" source: %s", cfs->source());
3779 }
3780 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3781 Thread* current = Thread::current();
3782 Klass* caller = current->is_Java_thread() ?
3783 JavaThread::cast(current)->security_get_caller_class(1):
3784 nullptr;
3785 // caller can be null, for example, during a JVMTI VM_Init hook
3786 if (caller != nullptr) {
3787 info_stream.print(" source: instance of %s", caller->external_name());
3788 } else {
3789 // source is unknown
3790 }
3791 } else {
3792 oop class_loader = loader_data->class_loader();
3793 info_stream.print(" source: %s", class_loader->klass()->external_name());
3794 }
3795 } else {
3796 assert(this->is_shared(), "must be");
3797 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3798 info_stream.print(" source: shared objects file (top)");
3799 } else {
3800 info_stream.print(" source: shared objects file");
3801 }
3802 }
3803
3804 msg.info("%s", info_stream.as_string());
3805
3806 if (log_is_enabled(Debug, class, load)) {
3807 stringStream debug_stream;
3808
3809 // Class hierarchy info
3810 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3811 p2i(this), p2i(superklass()));
3812
3813 // Interfaces
3814 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3815 debug_stream.print(" interfaces:");
3816 int length = local_interfaces()->length();
3817 for (int i = 0; i < length; i++) {
3818 debug_stream.print(" " PTR_FORMAT,
3819 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3820 }
3821 }
3822
3823 // Class loader
3824 debug_stream.print(" loader: [");
3825 loader_data->print_value_on(&debug_stream);
3826 debug_stream.print("]");
3827
3828 // Classfile checksum
3829 if (cfs) {
3830 debug_stream.print(" bytes: %d checksum: %08x",
3831 cfs->length(),
3832 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3833 cfs->length()));
3834 }
3835
3836 msg.debug("%s", debug_stream.as_string());
3837 }
3838 }
3839
3840 void InstanceKlass::print_class_load_cause_logging() const {
3841 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
3842 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
3843 JavaThread* current = JavaThread::current();
3844 ResourceMark rm(current);
3845 const char* name = external_name();
3846
3847 if (LogClassLoadingCauseFor == nullptr ||
3848 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
3849 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
3850 return;
3851 }
3852
3853 // Log Java stack first
3854 {
3855 LogMessage(class, load, cause) msg;
3856 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3857
3858 info_stream.print_cr("Java stack when loading %s:", name);
3859 current->print_stack_on(&info_stream);
3860 }
3861
3862 // Log native stack second
3863 if (log_cause_native) {
3864 // Log to string first so that lines can be indented
3865 stringStream stack_stream;
3866 char buf[O_BUFLEN];
3867 address lastpc = nullptr;
3868 if (os::platform_print_native_stack(&stack_stream, nullptr, buf, O_BUFLEN, lastpc)) {
3869 // We have printed the native stack in platform-specific code,
3870 // so nothing else to do in this case.
3871 } else {
3872 frame f = os::current_frame();
3873 VMError::print_native_stack(&stack_stream, f, current, true /*print_source_info */,
3874 -1 /* max stack_stream */, buf, O_BUFLEN);
3875 }
3876
3877 LogMessage(class, load, cause, native) msg;
3878 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3879 info_stream.print_cr("Native stack when loading %s:", name);
3880
3881 // Print each native stack line to the log
3882 int size = (int) stack_stream.size();
3883 char* stack = stack_stream.as_string();
3884 char* stack_end = stack + size;
3885 char* line_start = stack;
3886 for (char* p = stack; p < stack_end; p++) {
3887 if (*p == '\n') {
3888 *p = '\0';
3889 info_stream.print_cr("\t%s", line_start);
3890 line_start = p + 1;
3891 }
3892 }
3893 if (line_start < stack_end) {
3894 info_stream.print_cr("\t%s", line_start);
3895 }
3896 }
3897 }
3898 }
3899
3900 // Verification
3901
3902 class VerifyFieldClosure: public BasicOopIterateClosure {
3903 protected:
3904 template <class T> void do_oop_work(T* p) {
3905 oop obj = RawAccess<>::oop_load(p);
3906 if (!oopDesc::is_oop_or_null(obj)) {
3907 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3908 Universe::print_on(tty);
3909 guarantee(false, "boom");
3910 }
3911 }
3912 public:
3913 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3914 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3915 };
3916
3917 void InstanceKlass::verify_on(outputStream* st) {
3918 #ifndef PRODUCT
3919 // Avoid redundant verifies, this really should be in product.
3920 if (_verify_count == Universe::verify_count()) return;
3921 _verify_count = Universe::verify_count();
3922 #endif
3923
3924 // Verify Klass
3925 Klass::verify_on(st);
3926
3927 // Verify that klass is present in ClassLoaderData
3928 guarantee(class_loader_data()->contains_klass(this),
3929 "this class isn't found in class loader data");
3930
3931 // Verify vtables
3932 if (is_linked()) {
3933 // $$$ This used to be done only for m/s collections. Doing it
3934 // always seemed a valid generalization. (DLD -- 6/00)
3935 vtable().verify(st);
3936 }
3937
3938 // Verify first subklass
3939 if (subklass() != nullptr) {
3940 guarantee(subklass()->is_klass(), "should be klass");
3941 }
3942
3943 // Verify siblings
3944 Klass* super = this->super();
3945 Klass* sib = next_sibling();
3946 if (sib != nullptr) {
3947 if (sib == this) {
3948 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3949 }
3950
3951 guarantee(sib->is_klass(), "should be klass");
3952 guarantee(sib->super() == super, "siblings should have same superklass");
3953 }
3954
3955 // Verify local interfaces
3956 if (local_interfaces()) {
3957 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3958 for (int j = 0; j < local_interfaces->length(); j++) {
3959 InstanceKlass* e = local_interfaces->at(j);
3960 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3961 }
3962 }
3963
3964 // Verify transitive interfaces
3965 if (transitive_interfaces() != nullptr) {
3966 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3967 for (int j = 0; j < transitive_interfaces->length(); j++) {
3968 InstanceKlass* e = transitive_interfaces->at(j);
3969 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3970 }
3971 }
3972
3973 // Verify methods
3974 if (methods() != nullptr) {
3975 Array<Method*>* methods = this->methods();
3976 for (int j = 0; j < methods->length(); j++) {
3977 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3978 }
3979 for (int j = 0; j < methods->length() - 1; j++) {
3980 Method* m1 = methods->at(j);
3981 Method* m2 = methods->at(j + 1);
3982 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3983 }
3984 }
3985
3986 // Verify method ordering
3987 if (method_ordering() != nullptr) {
3988 Array<int>* method_ordering = this->method_ordering();
3989 int length = method_ordering->length();
3990 if (JvmtiExport::can_maintain_original_method_order() ||
3991 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
3992 guarantee(length == methods()->length(), "invalid method ordering length");
3993 jlong sum = 0;
3994 for (int j = 0; j < length; j++) {
3995 int original_index = method_ordering->at(j);
3996 guarantee(original_index >= 0, "invalid method ordering index");
3997 guarantee(original_index < length, "invalid method ordering index");
3998 sum += original_index;
3999 }
4000 // Verify sum of indices 0,1,...,length-1
4001 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4002 } else {
4003 guarantee(length == 0, "invalid method ordering length");
4004 }
4005 }
4006
4007 // Verify default methods
4008 if (default_methods() != nullptr) {
4009 Array<Method*>* methods = this->default_methods();
4010 for (int j = 0; j < methods->length(); j++) {
4011 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4012 }
4013 for (int j = 0; j < methods->length() - 1; j++) {
4014 Method* m1 = methods->at(j);
4015 Method* m2 = methods->at(j + 1);
4016 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4017 }
4018 }
4019
4020 // Verify JNI static field identifiers
4021 if (jni_ids() != nullptr) {
4022 jni_ids()->verify(this);
4023 }
4024
4025 // Verify other fields
4026 if (constants() != nullptr) {
4027 guarantee(constants()->is_constantPool(), "should be constant pool");
4028 }
4029 }
4030
4031 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4032 Klass::oop_verify_on(obj, st);
4033 VerifyFieldClosure blk;
4034 obj->oop_iterate(&blk);
4035 }
4036
4037
4038 // JNIid class for jfieldIDs only
4039 // Note to reviewers:
4040 // These JNI functions are just moved over to column 1 and not changed
4041 // in the compressed oops workspace.
4042 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4043 _holder = holder;
4044 _offset = offset;
4045 _next = next;
4046 debug_only(_is_static_field_id = false;)
4047 }
4048
4049
4050 JNIid* JNIid::find(int offset) {
4051 JNIid* current = this;
4052 while (current != nullptr) {
4053 if (current->offset() == offset) return current;
4054 current = current->next();
4055 }
4056 return nullptr;
4057 }
4058
4059 void JNIid::deallocate(JNIid* current) {
4060 while (current != nullptr) {
4061 JNIid* next = current->next();
4062 delete current;
4063 current = next;
4064 }
4065 }
4066
4067
4068 void JNIid::verify(Klass* holder) {
4069 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4070 int end_field_offset;
4071 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4072
4073 JNIid* current = this;
4074 while (current != nullptr) {
4075 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4076 #ifdef ASSERT
4077 int o = current->offset();
4078 if (current->is_static_field_id()) {
4079 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4080 }
4081 #endif
4082 current = current->next();
4083 }
4084 }
4085
4086 void InstanceKlass::set_init_state(ClassState state) {
4087 #ifdef ASSERT
4088 bool good_state = is_shared() ? (_init_state <= state)
4089 : (_init_state < state);
4090 assert(good_state || state == allocated, "illegal state transition");
4091 #endif
4092 assert(_init_thread == nullptr, "should be cleared before state change");
4093 _init_state = state;
4094 }
4095
4096 #if INCLUDE_JVMTI
4097
4098 // RedefineClasses() support for previous versions
4099
4100 // Globally, there is at least one previous version of a class to walk
4101 // during class unloading, which is saved because old methods in the class
4102 // are still running. Otherwise the previous version list is cleaned up.
4103 bool InstanceKlass::_should_clean_previous_versions = false;
4104
4105 // Returns true if there are previous versions of a class for class
4106 // unloading only. Also resets the flag to false. purge_previous_version
4107 // will set the flag to true if there are any left, i.e., if there's any
4108 // work to do for next time. This is to avoid the expensive code cache
4109 // walk in CLDG::clean_deallocate_lists().
4110 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4111 bool ret = _should_clean_previous_versions;
4112 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4113 ret ? "true" : "false");
4114 _should_clean_previous_versions = false;
4115 return ret;
4116 }
4117
4118 // This nulls out jmethodIDs for all methods in 'klass'
4119 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4120 // during class unloading.
4121 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4122 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4123 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4124 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4125 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4126 Array<Method*>* method_refs = klass->methods();
4127 for (int k = 0; k < method_refs->length(); k++) {
4128 Method* method = method_refs->at(k);
4129 if (method != nullptr && method->is_obsolete()) {
4130 method->clear_jmethod_id();
4131 }
4132 }
4133 }
4134
4135 // Purge previous versions before adding new previous versions of the class and
4136 // during class unloading.
4137 void InstanceKlass::purge_previous_version_list() {
4138 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4139 assert(has_been_redefined(), "Should only be called for main class");
4140
4141 // Quick exit.
4142 if (previous_versions() == nullptr) {
4143 return;
4144 }
4145
4146 // This klass has previous versions so see what we can cleanup
4147 // while it is safe to do so.
4148
4149 int deleted_count = 0; // leave debugging breadcrumbs
4150 int live_count = 0;
4151 ClassLoaderData* loader_data = class_loader_data();
4152 assert(loader_data != nullptr, "should never be null");
4153
4154 ResourceMark rm;
4155 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4156
4157 // previous versions are linked together through the InstanceKlass
4158 InstanceKlass* pv_node = previous_versions();
4159 InstanceKlass* last = this;
4160 int version = 0;
4161
4162 // check the previous versions list
4163 for (; pv_node != nullptr; ) {
4164
4165 ConstantPool* pvcp = pv_node->constants();
4166 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4167
4168 if (!pvcp->on_stack()) {
4169 // If the constant pool isn't on stack, none of the methods
4170 // are executing. Unlink this previous_version.
4171 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4172 // so will be deallocated during the next phase of class unloading.
4173 log_trace(redefine, class, iklass, purge)
4174 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4175 // Unlink from previous version list.
4176 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4177 InstanceKlass* next = pv_node->previous_versions();
4178 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4179 pv_node->link_previous_versions(nullptr); // point next to null
4180 last->link_previous_versions(next);
4181 // Delete this node directly. Nothing is referring to it and we don't
4182 // want it to increase the counter for metadata to delete in CLDG.
4183 MetadataFactory::free_metadata(loader_data, pv_node);
4184 pv_node = next;
4185 deleted_count++;
4186 version++;
4187 continue;
4188 } else {
4189 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4190 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4191 live_count++;
4192 if (pvcp->is_shared()) {
4193 // Shared previous versions can never be removed so no cleaning is needed.
4194 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4195 } else {
4196 // Previous version alive, set that clean is needed for next time.
4197 _should_clean_previous_versions = true;
4198 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4199 }
4200 }
4201
4202 // next previous version
4203 last = pv_node;
4204 pv_node = pv_node->previous_versions();
4205 version++;
4206 }
4207 log_trace(redefine, class, iklass, purge)
4208 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4209 }
4210
4211 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4212 int emcp_method_count) {
4213 int obsolete_method_count = old_methods->length() - emcp_method_count;
4214
4215 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4216 _previous_versions != nullptr) {
4217 // We have a mix of obsolete and EMCP methods so we have to
4218 // clear out any matching EMCP method entries the hard way.
4219 int local_count = 0;
4220 for (int i = 0; i < old_methods->length(); i++) {
4221 Method* old_method = old_methods->at(i);
4222 if (old_method->is_obsolete()) {
4223 // only obsolete methods are interesting
4224 Symbol* m_name = old_method->name();
4225 Symbol* m_signature = old_method->signature();
4226
4227 // previous versions are linked together through the InstanceKlass
4228 int j = 0;
4229 for (InstanceKlass* prev_version = _previous_versions;
4230 prev_version != nullptr;
4231 prev_version = prev_version->previous_versions(), j++) {
4232
4233 Array<Method*>* method_refs = prev_version->methods();
4234 for (int k = 0; k < method_refs->length(); k++) {
4235 Method* method = method_refs->at(k);
4236
4237 if (!method->is_obsolete() &&
4238 method->name() == m_name &&
4239 method->signature() == m_signature) {
4240 // The current RedefineClasses() call has made all EMCP
4241 // versions of this method obsolete so mark it as obsolete
4242 log_trace(redefine, class, iklass, add)
4243 ("%s(%s): flush obsolete method @%d in version @%d",
4244 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4245
4246 method->set_is_obsolete();
4247 break;
4248 }
4249 }
4250
4251 // The previous loop may not find a matching EMCP method, but
4252 // that doesn't mean that we can optimize and not go any
4253 // further back in the PreviousVersion generations. The EMCP
4254 // method for this generation could have already been made obsolete,
4255 // but there still may be an older EMCP method that has not
4256 // been made obsolete.
4257 }
4258
4259 if (++local_count >= obsolete_method_count) {
4260 // no more obsolete methods so bail out now
4261 break;
4262 }
4263 }
4264 }
4265 }
4266 }
4267
4268 // Save the scratch_class as the previous version if any of the methods are running.
4269 // The previous_versions are used to set breakpoints in EMCP methods and they are
4270 // also used to clean MethodData links to redefined methods that are no longer running.
4271 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4272 int emcp_method_count) {
4273 assert(Thread::current()->is_VM_thread(),
4274 "only VMThread can add previous versions");
4275
4276 ResourceMark rm;
4277 log_trace(redefine, class, iklass, add)
4278 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4279
4280 // Clean out old previous versions for this class
4281 purge_previous_version_list();
4282
4283 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4284 // a previous redefinition may be made obsolete by this redefinition.
4285 Array<Method*>* old_methods = scratch_class->methods();
4286 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4287
4288 // If the constant pool for this previous version of the class
4289 // is not marked as being on the stack, then none of the methods
4290 // in this previous version of the class are on the stack so
4291 // we don't need to add this as a previous version.
4292 ConstantPool* cp_ref = scratch_class->constants();
4293 if (!cp_ref->on_stack()) {
4294 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4295 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4296 return;
4297 }
4298
4299 // Add previous version if any methods are still running or if this is
4300 // a shared class which should never be removed.
4301 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4302 scratch_class->link_previous_versions(previous_versions());
4303 link_previous_versions(scratch_class);
4304 if (cp_ref->is_shared()) {
4305 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4306 } else {
4307 // We only set clean_previous_versions flag for processing during class
4308 // unloading for non-shared classes.
4309 _should_clean_previous_versions = true;
4310 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4311 }
4312 } // end add_previous_version()
4313
4314 #endif // INCLUDE_JVMTI
4315
4316 Method* InstanceKlass::method_with_idnum(int idnum) {
4317 Method* m = nullptr;
4318 if (idnum < methods()->length()) {
4319 m = methods()->at(idnum);
4320 }
4321 if (m == nullptr || m->method_idnum() != idnum) {
4322 for (int index = 0; index < methods()->length(); ++index) {
4323 m = methods()->at(index);
4324 if (m->method_idnum() == idnum) {
4325 return m;
4326 }
4327 }
4328 // None found, return null for the caller to handle.
4329 return nullptr;
4330 }
4331 return m;
4332 }
4333
4334
4335 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4336 if (idnum >= methods()->length()) {
4337 return nullptr;
4338 }
4339 Method* m = methods()->at(idnum);
4340 if (m != nullptr && m->orig_method_idnum() == idnum) {
4341 return m;
4342 }
4343 // Obsolete method idnum does not match the original idnum
4344 for (int index = 0; index < methods()->length(); ++index) {
4345 m = methods()->at(index);
4346 if (m->orig_method_idnum() == idnum) {
4347 return m;
4348 }
4349 }
4350 // None found, return null for the caller to handle.
4351 return nullptr;
4352 }
4353
4354
4355 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4356 InstanceKlass* holder = get_klass_version(version);
4357 if (holder == nullptr) {
4358 return nullptr; // The version of klass is gone, no method is found
4359 }
4360 Method* method = holder->method_with_orig_idnum(idnum);
4361 return method;
4362 }
4363
4364 #if INCLUDE_JVMTI
4365 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4366 return _cached_class_file;
4367 }
4368
4369 jint InstanceKlass::get_cached_class_file_len() {
4370 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4371 }
4372
4373 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4374 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4375 }
4376 #endif
4377
4378 // Make a step iterating over the class hierarchy under the root class.
4379 // Skips subclasses if requested.
4380 void ClassHierarchyIterator::next() {
4381 assert(_current != nullptr, "required");
4382 if (_visit_subclasses && _current->subklass() != nullptr) {
4383 _current = _current->subklass();
4384 return; // visit next subclass
4385 }
4386 _visit_subclasses = true; // reset
4387 while (_current->next_sibling() == nullptr && _current != _root) {
4388 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4389 }
4390 if (_current == _root) {
4391 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4392 _current = nullptr;
4393 return;
4394 }
4395 _current = _current->next_sibling();
4396 return; // visit next sibling subclass
4397 }