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