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