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