1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotClassInitializer.hpp"
26 #include "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "klass.inline.hpp"
55 #include "logging/logMessage.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/allocation.inline.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/metadataFactory.hpp"
60 #include "memory/metaspaceClosure.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/fieldStreams.inline.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/instanceClassLoaderKlass.hpp"
67 #include "oops/instanceKlass.inline.hpp"
68 #include "oops/instanceMirrorKlass.hpp"
69 #include "oops/instanceOop.hpp"
70 #include "oops/instanceStackChunkKlass.hpp"
71 #include "oops/klass.inline.hpp"
72 #include "oops/method.hpp"
73 #include "oops/oop.inline.hpp"
74 #include "oops/recordComponent.hpp"
75 #include "oops/symbol.hpp"
76 #include "prims/jvmtiExport.hpp"
77 #include "prims/jvmtiRedefineClasses.hpp"
78 #include "prims/jvmtiThreadState.hpp"
79 #include "prims/methodComparator.hpp"
80 #include "runtime/arguments.hpp"
81 #include "runtime/deoptimization.hpp"
82 #include "runtime/atomic.hpp"
83 #include "runtime/fieldDescriptor.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/javaCalls.hpp"
86 #include "runtime/javaThread.inline.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/orderAccess.hpp"
89 #include "runtime/os.inline.hpp"
90 #include "runtime/reflection.hpp"
91 #include "runtime/synchronizer.hpp"
92 #include "runtime/threads.hpp"
93 #include "services/classLoadingService.hpp"
94 #include "services/finalizerService.hpp"
95 #include "services/threadService.hpp"
96 #include "utilities/dtrace.hpp"
97 #include "utilities/events.hpp"
98 #include "utilities/macros.hpp"
99 #include "utilities/nativeStackPrinter.hpp"
100 #include "utilities/pair.hpp"
101 #include "utilities/stringUtils.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 // The incoming stringStream is used to format the messages for error logging and for the caller
216 // to use for exception throwing.
217 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
218 Thread* current = Thread::current();
219 assert(k != nullptr, "sanity check");
220 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
221 "unexpected empty _permitted_subclasses array");
222
223 if (log_is_enabled(Trace, class, sealed)) {
224 ResourceMark rm(current);
225 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
226 k->external_name(), this->external_name());
227 }
228
229 // Check that the class and its super are in the same module.
230 if (k->module() != this->module()) {
231 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
232 "and sealed class %s is in module '%s' with loader %s",
233 k->external_name(),
234 k->module()->name_as_C_string(),
235 k->module()->loader_data()->loader_name_and_id(),
236 this->external_name(),
237 this->module()->name_as_C_string(),
238 this->module()->loader_data()->loader_name_and_id());
239 log_trace(class, sealed)(" - %s", ss.as_string());
240 return false;
241 }
242
243 if (!k->is_public() && !is_same_class_package(k)) {
244 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
245 "and sealed class %s is in package '%s' with classloader %s",
246 k->external_name(),
247 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
248 k->module()->loader_data()->loader_name_and_id(),
249 this->external_name(),
250 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
251 this->module()->loader_data()->loader_name_and_id());
252 log_trace(class, sealed)(" - %s", ss.as_string());
253 return false;
254 }
255
256 for (int i = 0; i < _permitted_subclasses->length(); i++) {
257 int cp_index = _permitted_subclasses->at(i);
258 Symbol* name = _constants->klass_name_at(cp_index);
259 if (name == k->name()) {
260 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
261 return true;
262 }
263 }
264
265 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
266 k->external_name(), this->external_name());
267 log_trace(class, sealed)(" - %s", ss.as_string());
268 return false;
269 }
270
271 // Return nest-host class, resolving, validating and saving it if needed.
272 // In cases where this is called from a thread that cannot do classloading
273 // (such as a native JIT thread) then we simply return null, which in turn
274 // causes the access check to return false. Such code will retry the access
275 // from a more suitable environment later. Otherwise the _nest_host is always
276 // set once this method returns.
277 // Any errors from nest-host resolution must be preserved so they can be queried
278 // from higher-level access checking code, and reported as part of access checking
279 // exceptions.
280 // VirtualMachineErrors are propagated with a null return.
281 // Under any conditions where the _nest_host can be set to non-null the resulting
282 // value of it and, if applicable, the nest host resolution/validation error,
283 // are idempotent.
284 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
285 InstanceKlass* nest_host_k = _nest_host;
286 if (nest_host_k != nullptr) {
287 return nest_host_k;
288 }
289
290 ResourceMark rm(THREAD);
291
292 // need to resolve and save our nest-host class.
293 if (_nest_host_index != 0) { // we have a real nest_host
294 // Before trying to resolve check if we're in a suitable context
295 bool can_resolve = THREAD->can_call_java();
296 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
297 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
298 this->external_name());
299 return nullptr; // sentinel to say "try again from a different context"
300 }
301
302 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
303 this->external_name(),
304 _constants->klass_name_at(_nest_host_index)->as_C_string());
305
306 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
307 if (HAS_PENDING_EXCEPTION) {
308 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
309 return nullptr; // propagate VMEs
310 }
311 stringStream ss;
312 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
313 ss.print("Nest host resolution of %s with host %s failed: ",
314 this->external_name(), target_host_class);
315 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
316 const char* msg = ss.as_string(true /* on C-heap */);
317 constantPoolHandle cph(THREAD, constants());
318 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
319 CLEAR_PENDING_EXCEPTION;
320
321 log_trace(class, nestmates)("%s", msg);
322 } else {
323 // A valid nest-host is an instance class in the current package that lists this
324 // class as a nest member. If any of these conditions are not met the class is
325 // its own nest-host.
326 const char* error = nullptr;
327
328 // JVMS 5.4.4 indicates package check comes first
329 if (is_same_class_package(k)) {
330 // Now check actual membership. We can't be a member if our "host" is
331 // not an instance class.
332 if (k->is_instance_klass()) {
333 nest_host_k = InstanceKlass::cast(k);
334 bool is_member = nest_host_k->has_nest_member(THREAD, this);
335 if (is_member) {
336 _nest_host = nest_host_k; // save resolved nest-host value
337
338 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
339 this->external_name(), k->external_name());
340 return nest_host_k;
341 } else {
342 error = "current type is not listed as a nest member";
343 }
344 } else {
345 error = "host is not an instance class";
346 }
347 } else {
348 error = "types are in different packages";
349 }
350
351 // something went wrong, so record what and log it
352 {
353 stringStream ss;
354 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
355 this->external_name(),
356 this->class_loader_data()->loader_name_and_id(),
357 k->external_name(),
358 k->class_loader_data()->loader_name_and_id(),
359 error);
360 const char* msg = ss.as_string(true /* on C-heap */);
361 constantPoolHandle cph(THREAD, constants());
362 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
363 log_trace(class, nestmates)("%s", msg);
364 }
365 }
366 } else {
367 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
368 this->external_name());
369 }
370
371 // Either not in an explicit nest, or else an error occurred, so
372 // the nest-host is set to `this`. Any thread that sees this assignment
373 // will also see any setting of nest_host_error(), if applicable.
374 return (_nest_host = this);
375 }
376
377 // Dynamic nest member support: set this class's nest host to the given class.
378 // This occurs as part of the class definition, as soon as the instanceKlass
379 // has been created and doesn't require further resolution. The code:
380 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
381 // results in:
382 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
383 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
384 // We also know the "host" is a valid nest-host in the same package so we can
385 // assert some of those facts.
386 void InstanceKlass::set_nest_host(InstanceKlass* host) {
387 assert(is_hidden(), "must be a hidden class");
388 assert(host != nullptr, "null nest host specified");
389 assert(_nest_host == nullptr, "current class has resolved nest-host");
390 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
391 nest_host_error());
392 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
393 (host->_nest_host == host), "proposed host is not a valid nest-host");
394 // Can't assert this as package is not set yet:
395 // assert(is_same_class_package(host), "proposed host is in wrong package");
396
397 if (log_is_enabled(Trace, class, nestmates)) {
398 ResourceMark rm;
399 const char* msg = "";
400 // a hidden class does not expect a statically defined nest-host
401 if (_nest_host_index > 0) {
402 msg = "(the NestHost attribute in the current class is ignored)";
403 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
404 msg = "(the NestMembers attribute in the current class is ignored)";
405 }
406 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
407 this->external_name(),
408 host->external_name(),
409 msg);
410 }
411 // set dynamic nest host
412 _nest_host = host;
413 // Record dependency to keep nest host from being unloaded before this class.
414 ClassLoaderData* this_key = class_loader_data();
415 assert(this_key != nullptr, "sanity");
416 this_key->record_dependency(host);
417 }
418
419 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
420 // or we are k's nest_host - all of which is covered by comparing the two
421 // resolved_nest_hosts.
422 // Any exceptions (i.e. VMEs) are propagated.
423 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
424
425 assert(this != k, "this should be handled by higher-level code");
426
427 // Per JVMS 5.4.4 we first resolve and validate the current class, then
428 // the target class k.
429
430 InstanceKlass* cur_host = nest_host(CHECK_false);
431 if (cur_host == nullptr) {
432 return false;
433 }
434
435 Klass* k_nest_host = k->nest_host(CHECK_false);
436 if (k_nest_host == nullptr) {
437 return false;
438 }
439
440 bool access = (cur_host == k_nest_host);
441
442 ResourceMark rm(THREAD);
443 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
444 this->external_name(),
445 access ? "" : "NOT ",
446 k->external_name());
447 return access;
448 }
449
450 const char* InstanceKlass::nest_host_error() {
451 if (_nest_host_index == 0) {
452 return nullptr;
453 } else {
454 constantPoolHandle cph(Thread::current(), constants());
455 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
456 }
457 }
458
459 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
460 bool use_class_space, TRAPS) throw() {
461 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
462 }
463
464 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
465 const int size = InstanceKlass::size(parser.vtable_size(),
466 parser.itable_size(),
467 nonstatic_oop_map_size(parser.total_oop_map_count()),
468 parser.is_interface());
469
470 const Symbol* const class_name = parser.class_name();
471 assert(class_name != nullptr, "invariant");
472 ClassLoaderData* loader_data = parser.loader_data();
473 assert(loader_data != nullptr, "invariant");
474
475 InstanceKlass* ik;
476 const bool use_class_space = parser.klass_needs_narrow_id();
477
478 // Allocation
479 if (parser.is_instance_ref_klass()) {
480 // java.lang.ref.Reference
481 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
482 } else if (class_name == vmSymbols::java_lang_Class()) {
483 // mirror - java.lang.Class
484 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
485 } else if (is_stack_chunk_class(class_name, loader_data)) {
486 // stack chunk
487 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
488 } else if (is_class_loader(class_name, parser)) {
489 // class loader - java.lang.ClassLoader
490 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
491 } else {
492 // normal
493 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
494 }
495
496 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
497 assert(CompressedKlassPointers::is_encodable(ik),
498 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
499 }
500
501 // Check for pending exception before adding to the loader data and incrementing
502 // class count. Can get OOM here.
503 if (HAS_PENDING_EXCEPTION) {
504 return nullptr;
505 }
506
507 return ik;
508 }
509
510
511 // copy method ordering from resource area to Metaspace
512 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
513 if (m != nullptr) {
514 // allocate a new array and copy contents (memcpy?)
515 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
516 for (int i = 0; i < m->length(); i++) {
517 _method_ordering->at_put(i, m->at(i));
518 }
519 } else {
520 _method_ordering = Universe::the_empty_int_array();
521 }
522 }
523
524 // create a new array of vtable_indices for default methods
525 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
526 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
527 assert(default_vtable_indices() == nullptr, "only create once");
528 set_default_vtable_indices(vtable_indices);
529 return vtable_indices;
530 }
531
532
533 InstanceKlass::InstanceKlass() {
534 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
535 }
536
537 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
538 Klass(kind),
539 _nest_members(nullptr),
540 _nest_host(nullptr),
541 _permitted_subclasses(nullptr),
542 _record_components(nullptr),
543 _static_field_size(parser.static_field_size()),
544 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
545 _itable_len(parser.itable_size()),
546 _nest_host_index(0),
547 _init_state(allocated),
548 _reference_type(reference_type),
549 _init_thread(nullptr)
550 {
551 set_vtable_length(parser.vtable_size());
552 set_access_flags(parser.access_flags());
553 if (parser.is_hidden()) set_is_hidden();
554 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
555 false));
556
557 assert(nullptr == _methods, "underlying memory not zeroed?");
558 assert(is_instance_klass(), "is layout incorrect?");
559 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
560 }
561
562 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
563 Array<Method*>* methods) {
564 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
565 !methods->is_shared()) {
566 for (int i = 0; i < methods->length(); i++) {
567 Method* method = methods->at(i);
568 if (method == nullptr) continue; // maybe null if error processing
569 // Only want to delete methods that are not executing for RedefineClasses.
570 // The previous version will point to them so they're not totally dangling
571 assert (!method->on_stack(), "shouldn't be called with methods on stack");
572 MetadataFactory::free_metadata(loader_data, method);
573 }
574 MetadataFactory::free_array<Method*>(loader_data, methods);
575 }
576 }
577
578 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
579 const Klass* super_klass,
580 Array<InstanceKlass*>* local_interfaces,
581 Array<InstanceKlass*>* transitive_interfaces) {
582 // Only deallocate transitive interfaces if not empty, same as super class
583 // or same as local interfaces. See code in parseClassFile.
584 Array<InstanceKlass*>* ti = transitive_interfaces;
585 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
586 // check that the interfaces don't come from super class
587 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
588 InstanceKlass::cast(super_klass)->transitive_interfaces();
589 if (ti != sti && ti != nullptr && !ti->is_shared()) {
590 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
591 }
592 }
593
594 // local interfaces can be empty
595 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
596 local_interfaces != nullptr && !local_interfaces->is_shared()) {
597 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
598 }
599 }
600
601 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
602 Array<RecordComponent*>* record_components) {
603 if (record_components != nullptr && !record_components->is_shared()) {
604 for (int i = 0; i < record_components->length(); i++) {
605 RecordComponent* record_component = record_components->at(i);
606 MetadataFactory::free_metadata(loader_data, record_component);
607 }
608 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
609 }
610 }
611
612 // This function deallocates the metadata and C heap pointers that the
613 // InstanceKlass points to.
614 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
615 // Orphan the mirror first, CMS thinks it's still live.
616 if (java_mirror() != nullptr) {
617 java_lang_Class::set_klass(java_mirror(), nullptr);
618 }
619
620 // Also remove mirror from handles
621 loader_data->remove_handle(_java_mirror);
622
623 // Need to take this class off the class loader data list.
624 loader_data->remove_class(this);
625
626 // The array_klass for this class is created later, after error handling.
627 // For class redefinition, we keep the original class so this scratch class
628 // doesn't have an array class. Either way, assert that there is nothing
629 // to deallocate.
630 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
631
632 // Release C heap allocated data that this points to, which includes
633 // reference counting symbol names.
634 // Can't release the constant pool or MethodData C heap data here because the constant
635 // pool can be deallocated separately from the InstanceKlass for default methods and
636 // redefine classes. MethodData can also be released separately.
637 release_C_heap_structures(/* release_sub_metadata */ false);
638
639 deallocate_methods(loader_data, methods());
640 set_methods(nullptr);
641
642 deallocate_record_components(loader_data, record_components());
643 set_record_components(nullptr);
644
645 if (method_ordering() != nullptr &&
646 method_ordering() != Universe::the_empty_int_array() &&
647 !method_ordering()->is_shared()) {
648 MetadataFactory::free_array<int>(loader_data, method_ordering());
649 }
650 set_method_ordering(nullptr);
651
652 // default methods can be empty
653 if (default_methods() != nullptr &&
654 default_methods() != Universe::the_empty_method_array() &&
655 !default_methods()->is_shared()) {
656 MetadataFactory::free_array<Method*>(loader_data, default_methods());
657 }
658 // Do NOT deallocate the default methods, they are owned by superinterfaces.
659 set_default_methods(nullptr);
660
661 // default methods vtable indices can be empty
662 if (default_vtable_indices() != nullptr &&
663 !default_vtable_indices()->is_shared()) {
664 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
665 }
666 set_default_vtable_indices(nullptr);
667
668
669 // This array is in Klass, but remove it with the InstanceKlass since
670 // this place would be the only caller and it can share memory with transitive
671 // interfaces.
672 if (secondary_supers() != nullptr &&
673 secondary_supers() != Universe::the_empty_klass_array() &&
674 // see comments in compute_secondary_supers about the following cast
675 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
676 !secondary_supers()->is_shared()) {
677 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
678 }
679 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
680
681 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
682 set_transitive_interfaces(nullptr);
683 set_local_interfaces(nullptr);
684
685 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
686 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
687 }
688 set_fieldinfo_stream(nullptr);
689
690 if (fields_status() != nullptr && !fields_status()->is_shared()) {
691 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
692 }
693 set_fields_status(nullptr);
694
695 // If a method from a redefined class is using this constant pool, don't
696 // delete it, yet. The new class's previous version will point to this.
697 if (constants() != nullptr) {
698 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
699 if (!constants()->is_shared()) {
700 MetadataFactory::free_metadata(loader_data, constants());
701 }
702 // Delete any cached resolution errors for the constant pool
703 SystemDictionary::delete_resolution_error(constants());
704
705 set_constants(nullptr);
706 }
707
708 if (inner_classes() != nullptr &&
709 inner_classes() != Universe::the_empty_short_array() &&
710 !inner_classes()->is_shared()) {
711 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
712 }
713 set_inner_classes(nullptr);
714
715 if (nest_members() != nullptr &&
716 nest_members() != Universe::the_empty_short_array() &&
717 !nest_members()->is_shared()) {
718 MetadataFactory::free_array<jushort>(loader_data, nest_members());
719 }
720 set_nest_members(nullptr);
721
722 if (permitted_subclasses() != nullptr &&
723 permitted_subclasses() != Universe::the_empty_short_array() &&
724 !permitted_subclasses()->is_shared()) {
725 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
726 }
727 set_permitted_subclasses(nullptr);
728
729 // We should deallocate the Annotations instance if it's not in shared spaces.
730 if (annotations() != nullptr && !annotations()->is_shared()) {
731 MetadataFactory::free_metadata(loader_data, annotations());
732 }
733 set_annotations(nullptr);
734
735 SystemDictionaryShared::handle_class_unloading(this);
736
737 #if INCLUDE_CDS_JAVA_HEAP
738 if (CDSConfig::is_dumping_heap()) {
739 HeapShared::remove_scratch_objects(this);
740 }
741 #endif
742 }
743
744 bool InstanceKlass::is_record() const {
745 return _record_components != nullptr &&
746 is_final() &&
747 java_super() == vmClasses::Record_klass();
748 }
749
750 bool InstanceKlass::is_sealed() const {
751 return _permitted_subclasses != nullptr &&
752 _permitted_subclasses != Universe::the_empty_short_array();
753 }
754
755 // JLS 8.9: An enum class is either implicitly final and derives
756 // from java.lang.Enum, or else is implicitly sealed to its
757 // anonymous subclasses. This query detects both kinds.
758 // It does not validate the finality or
759 // sealing conditions: it merely checks for a super of Enum.
760 // This is sufficient for recognizing well-formed enums.
761 bool InstanceKlass::is_enum_subclass() const {
762 InstanceKlass* s = java_super();
763 return (s == vmClasses::Enum_klass() ||
764 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
765 }
766
767 bool InstanceKlass::should_be_initialized() const {
768 return !is_initialized();
769 }
770
771 klassItable InstanceKlass::itable() const {
772 return klassItable(const_cast<InstanceKlass*>(this));
773 }
774
775 // JVMTI spec thinks there are signers and protection domain in the
776 // instanceKlass. These accessors pretend these fields are there.
777 // The hprof specification also thinks these fields are in InstanceKlass.
778 oop InstanceKlass::protection_domain() const {
779 // return the protection_domain from the mirror
780 return java_lang_Class::protection_domain(java_mirror());
781 }
782
783 objArrayOop InstanceKlass::signers() const {
784 // return the signers from the mirror
785 return java_lang_Class::signers(java_mirror());
786 }
787
788 oop InstanceKlass::init_lock() const {
789 // return the init lock from the mirror
790 oop lock = java_lang_Class::init_lock(java_mirror());
791 // Prevent reordering with any access of initialization state
792 OrderAccess::loadload();
793 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
794 "only fully initialized state can have a null lock");
795 return lock;
796 }
797
798 // Set the initialization lock to null so the object can be GC'ed. Any racing
799 // threads to get this lock will see a null lock and will not lock.
800 // That's okay because they all check for initialized state after getting
801 // the lock and return.
802 void InstanceKlass::fence_and_clear_init_lock() {
803 // make sure previous stores are all done, notably the init_state.
804 OrderAccess::storestore();
805 java_lang_Class::clear_init_lock(java_mirror());
806 assert(!is_not_initialized(), "class must be initialized now");
807 }
808
809
810 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
811 // process. The step comments refers to the procedure described in that section.
812 // Note: implementation moved to static method to expose the this pointer.
813 void InstanceKlass::initialize(TRAPS) {
814 if (this->should_be_initialized()) {
815 initialize_impl(CHECK);
816 // Note: at this point the class may be initialized
817 // OR it may be in the state of being initialized
818 // in case of recursive initialization!
819 } else {
820 assert(is_initialized(), "sanity check");
821 }
822 }
823
824 #ifdef ASSERT
825 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
826 assert(has_aot_initialized_mirror(), "must be");
827
828 InstanceKlass* s = java_super();
829 if (s != nullptr) {
830 DEBUG_ONLY(ResourceMark rm);
831 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
832 s->external_name(), external_name());
833 s->assert_no_clinit_will_run_for_aot_initialized_class();
834 }
835
836 Array<InstanceKlass*>* interfaces = local_interfaces();
837 int len = interfaces->length();
838 for (int i = 0; i < len; i++) {
839 InstanceKlass* intf = interfaces->at(i);
840 if (!intf->is_initialized()) {
841 ResourceMark rm;
842 // Note: an interface needs to be marked as is_initialized() only if
843 // - it has a <clinit>
844 // - it has declared a default method.
845 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
846 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
847 intf->external_name(), external_name());
848 }
849 }
850 }
851 #endif
852
853 #if INCLUDE_CDS
854 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
855 assert(has_aot_initialized_mirror(), "must be");
856 assert(CDSConfig::is_loading_heap(), "must be");
857 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
858 assert_no_clinit_will_run_for_aot_initialized_class();
859
860 if (is_initialized()) {
861 return;
862 }
863
864 if (log_is_enabled(Info, cds, init)) {
865 ResourceMark rm;
866 log_info(cds, init)("%s (aot-inited)", external_name());
867 }
868
869 link_class(CHECK);
870
871 #ifdef ASSERT
872 {
873 Handle h_init_lock(THREAD, init_lock());
874 ObjectLocker ol(h_init_lock, THREAD);
875 assert(!is_initialized(), "sanity");
876 assert(!is_being_initialized(), "sanity");
877 assert(!is_in_error_state(), "sanity");
878 }
879 #endif
880
881 set_init_thread(THREAD);
882 AOTClassInitializer::call_runtime_setup(THREAD, this);
883 set_initialization_state_and_notify(fully_initialized, CHECK);
884 }
885 #endif
886
887 bool InstanceKlass::verify_code(TRAPS) {
888 // 1) Verify the bytecodes
889 return Verifier::verify(this, should_verify_class(), THREAD);
890 }
891
892 void InstanceKlass::link_class(TRAPS) {
893 assert(is_loaded(), "must be loaded");
894 if (!is_linked()) {
895 link_class_impl(CHECK);
896 }
897 }
898
899 // Called to verify that a class can link during initialization, without
900 // throwing a VerifyError.
901 bool InstanceKlass::link_class_or_fail(TRAPS) {
902 assert(is_loaded(), "must be loaded");
903 if (!is_linked()) {
904 link_class_impl(CHECK_false);
905 }
906 return is_linked();
907 }
908
909 bool InstanceKlass::link_class_impl(TRAPS) {
910 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
911 // This is for CDS static dump only -- we use the in_error_state to indicate that
912 // the class has failed verification. Throwing the NoClassDefFoundError here is just
913 // a convenient way to stop repeat attempts to verify the same (bad) class.
914 //
915 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
916 // if we are executing Java code. This is not a problem for CDS dumping phase since
917 // it doesn't execute any Java code.
918 ResourceMark rm(THREAD);
919 // Names are all known to be < 64k so we know this formatted message is not excessively large.
920 Exceptions::fthrow(THREAD_AND_LOCATION,
921 vmSymbols::java_lang_NoClassDefFoundError(),
922 "Class %s, or one of its supertypes, failed class initialization",
923 external_name());
924 return false;
925 }
926 // return if already verified
927 if (is_linked()) {
928 return true;
929 }
930
931 // Timing
932 // timer handles recursion
933 JavaThread* jt = THREAD;
934
935 // link super class before linking this class
936 Klass* super_klass = super();
937 if (super_klass != nullptr) {
938 if (super_klass->is_interface()) { // check if super class is an interface
939 ResourceMark rm(THREAD);
940 // Names are all known to be < 64k so we know this formatted message is not excessively large.
941 Exceptions::fthrow(
942 THREAD_AND_LOCATION,
943 vmSymbols::java_lang_IncompatibleClassChangeError(),
944 "class %s has interface %s as super class",
945 external_name(),
946 super_klass->external_name()
947 );
948 return false;
949 }
950
951 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
952 ik_super->link_class_impl(CHECK_false);
953 }
954
955 // link all interfaces implemented by this class before linking this class
956 Array<InstanceKlass*>* interfaces = local_interfaces();
957 int num_interfaces = interfaces->length();
958 for (int index = 0; index < num_interfaces; index++) {
959 InstanceKlass* interk = interfaces->at(index);
960 interk->link_class_impl(CHECK_false);
961 }
962
963 // in case the class is linked in the process of linking its superclasses
964 if (is_linked()) {
965 return true;
966 }
967
968 // trace only the link time for this klass that includes
969 // the verification time
970 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
971 ClassLoader::perf_class_link_selftime(),
972 ClassLoader::perf_classes_linked(),
973 jt->get_thread_stat()->perf_recursion_counts_addr(),
974 jt->get_thread_stat()->perf_timers_addr(),
975 PerfClassTraceTime::CLASS_LINK);
976
977 // verification & rewriting
978 {
979 HandleMark hm(THREAD);
980 Handle h_init_lock(THREAD, init_lock());
981 ObjectLocker ol(h_init_lock, jt);
982 // rewritten will have been set if loader constraint error found
983 // on an earlier link attempt
984 // don't verify or rewrite if already rewritten
985 //
986
987 if (!is_linked()) {
988 if (!is_rewritten()) {
989 if (is_shared()) {
990 assert(!verified_at_dump_time(), "must be");
991 }
992 {
993 bool verify_ok = verify_code(THREAD);
994 if (!verify_ok) {
995 return false;
996 }
997 }
998
999 // Just in case a side-effect of verify linked this class already
1000 // (which can sometimes happen since the verifier loads classes
1001 // using custom class loaders, which are free to initialize things)
1002 if (is_linked()) {
1003 return true;
1004 }
1005
1006 // also sets rewritten
1007 rewrite_class(CHECK_false);
1008 } else if (is_shared()) {
1009 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1010 }
1011
1012 // relocate jsrs and link methods after they are all rewritten
1013 link_methods(CHECK_false);
1014
1015 // Initialize the vtable and interface table after
1016 // methods have been rewritten since rewrite may
1017 // fabricate new Method*s.
1018 // also does loader constraint checking
1019 //
1020 // initialize_vtable and initialize_itable need to be rerun
1021 // for a shared class if
1022 // 1) the class is loaded by custom class loader or
1023 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1024 // 3) the class was not verified during dump time
1025 bool need_init_table = true;
1026 if (is_shared() && verified_at_dump_time() &&
1027 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1028 need_init_table = false;
1029 }
1030 if (need_init_table) {
1031 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1032 itable().initialize_itable_and_check_constraints(CHECK_false);
1033 }
1034 #ifdef ASSERT
1035 vtable().verify(tty, true);
1036 // In case itable verification is ever added.
1037 // itable().verify(tty, true);
1038 #endif
1039 if (Universe::is_fully_initialized()) {
1040 DeoptimizationScope deopt_scope;
1041 {
1042 // Now mark all code that assumes the class is not linked.
1043 // Set state under the Compile_lock also.
1044 MutexLocker ml(THREAD, Compile_lock);
1045
1046 set_init_state(linked);
1047 CodeCache::mark_dependents_on(&deopt_scope, this);
1048 }
1049 // Perform the deopt handshake outside Compile_lock.
1050 deopt_scope.deoptimize_marked();
1051 } else {
1052 set_init_state(linked);
1053 }
1054 if (JvmtiExport::should_post_class_prepare()) {
1055 JvmtiExport::post_class_prepare(THREAD, this);
1056 }
1057 }
1058 }
1059 return true;
1060 }
1061
1062 // Rewrite the byte codes of all of the methods of a class.
1063 // The rewriter must be called exactly once. Rewriting must happen after
1064 // verification but before the first method of the class is executed.
1065 void InstanceKlass::rewrite_class(TRAPS) {
1066 assert(is_loaded(), "must be loaded");
1067 if (is_rewritten()) {
1068 assert(is_shared(), "rewriting an unshared class?");
1069 return;
1070 }
1071 Rewriter::rewrite(this, CHECK);
1072 set_rewritten();
1073 }
1074
1075 // Now relocate and link method entry points after class is rewritten.
1076 // This is outside is_rewritten flag. In case of an exception, it can be
1077 // executed more than once.
1078 void InstanceKlass::link_methods(TRAPS) {
1079 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1080
1081 int len = methods()->length();
1082 for (int i = len-1; i >= 0; i--) {
1083 methodHandle m(THREAD, methods()->at(i));
1084
1085 // Set up method entry points for compiler and interpreter .
1086 m->link_method(m, CHECK);
1087 }
1088 }
1089
1090 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1091 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1092 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1093 for (int i = 0; i < local_interfaces()->length(); ++i) {
1094 InstanceKlass* ik = local_interfaces()->at(i);
1095
1096 // Initialization is depth first search ie. we start with top of the inheritance tree
1097 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1098 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1099 if (ik->has_nonstatic_concrete_methods()) {
1100 ik->initialize_super_interfaces(CHECK);
1101 }
1102
1103 // Only initialize() interfaces that "declare" concrete methods.
1104 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1105 ik->initialize(CHECK);
1106 }
1107 }
1108 }
1109
1110 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1111 static InitializationErrorTable* _initialization_error_table;
1112
1113 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1114 // Create the same exception with a message indicating the thread name,
1115 // and the StackTraceElements.
1116 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1117 ResourceMark rm(current);
1118 if (init_error.is_null()) {
1119 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1120
1121 // We failed to create the new exception, most likely due to either out-of-memory or
1122 // a stackoverflow error. If the original exception was either of those then we save
1123 // the shared, pre-allocated, stackless, instance of that exception.
1124 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1125 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1126 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1127 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1128 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1129 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1130 } else {
1131 return;
1132 }
1133 }
1134
1135 MutexLocker ml(current, ClassInitError_lock);
1136 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1137 bool created;
1138 if (_initialization_error_table == nullptr) {
1139 _initialization_error_table = new (mtClass) InitializationErrorTable();
1140 }
1141 _initialization_error_table->put_if_absent(this, elem, &created);
1142 assert(created, "Initialization is single threaded");
1143 log_trace(class, init)("Initialization error added for class %s", external_name());
1144 }
1145
1146 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1147 MutexLocker ml(current, ClassInitError_lock);
1148 if (_initialization_error_table == nullptr) {
1149 return nullptr;
1150 }
1151 OopHandle* h = _initialization_error_table->get(this);
1152 return (h != nullptr) ? h->resolve() : nullptr;
1153 }
1154
1155 // Need to remove entries for unloaded classes.
1156 void InstanceKlass::clean_initialization_error_table() {
1157 struct InitErrorTableCleaner {
1158 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1159 if (!ik->is_loader_alive()) {
1160 h.release(Universe::vm_global());
1161 return true;
1162 } else {
1163 return false;
1164 }
1165 }
1166 };
1167
1168 assert_locked_or_safepoint(ClassInitError_lock);
1169 InitErrorTableCleaner cleaner;
1170 if (_initialization_error_table != nullptr) {
1171 _initialization_error_table->unlink(&cleaner);
1172 }
1173 }
1174
1175 void InstanceKlass::initialize_impl(TRAPS) {
1176 HandleMark hm(THREAD);
1177
1178 // Make sure klass is linked (verified) before initialization
1179 // A class could already be verified, since it has been reflected upon.
1180 link_class(CHECK);
1181
1182 DTRACE_CLASSINIT_PROBE(required, -1);
1183
1184 bool wait = false;
1185
1186 JavaThread* jt = THREAD;
1187
1188 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1189
1190 // refer to the JVM book page 47 for description of steps
1191 // Step 1
1192 {
1193 Handle h_init_lock(THREAD, init_lock());
1194 ObjectLocker ol(h_init_lock, jt);
1195
1196 // Step 2
1197 // If we were to use wait() instead of waitInterruptibly() then
1198 // we might end up throwing IE from link/symbol resolution sites
1199 // that aren't expected to throw. This would wreak havoc. See 6320309.
1200 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1201 if (debug_logging_enabled) {
1202 ResourceMark rm(jt);
1203 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1204 jt->name(), external_name(), init_thread_name());
1205 }
1206 wait = true;
1207 jt->set_class_to_be_initialized(this);
1208 ol.wait_uninterruptibly(jt);
1209 jt->set_class_to_be_initialized(nullptr);
1210 }
1211
1212 // Step 3
1213 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1214 if (debug_logging_enabled) {
1215 ResourceMark rm(jt);
1216 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1217 jt->name(), external_name());
1218 }
1219 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1220 return;
1221 }
1222
1223 // Step 4
1224 if (is_initialized()) {
1225 if (debug_logging_enabled) {
1226 ResourceMark rm(jt);
1227 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1228 jt->name(), external_name());
1229 }
1230 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1231 return;
1232 }
1233
1234 // Step 5
1235 if (is_in_error_state()) {
1236 if (debug_logging_enabled) {
1237 ResourceMark rm(jt);
1238 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1239 jt->name(), external_name());
1240 }
1241
1242 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1243 ResourceMark rm(THREAD);
1244 Handle cause(THREAD, get_initialization_error(THREAD));
1245
1246 stringStream ss;
1247 ss.print("Could not initialize class %s", external_name());
1248 if (cause.is_null()) {
1249 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1250 } else {
1251 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1252 ss.as_string(), cause);
1253 }
1254 } else {
1255
1256 // Step 6
1257 set_init_state(being_initialized);
1258 set_init_thread(jt);
1259 if (debug_logging_enabled) {
1260 ResourceMark rm(jt);
1261 log_debug(class, init)("Thread \"%s\" is initializing %s",
1262 jt->name(), external_name());
1263 }
1264 }
1265 }
1266
1267 // Step 7
1268 // Next, if C is a class rather than an interface, initialize it's super class and super
1269 // interfaces.
1270 if (!is_interface()) {
1271 Klass* super_klass = super();
1272 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1273 super_klass->initialize(THREAD);
1274 }
1275 // If C implements any interface that declares a non-static, concrete method,
1276 // the initialization of C triggers initialization of its super interfaces.
1277 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1278 // having a superinterface that declares, non-static, concrete methods
1279 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1280 initialize_super_interfaces(THREAD);
1281 }
1282
1283 // If any exceptions, complete abruptly, throwing the same exception as above.
1284 if (HAS_PENDING_EXCEPTION) {
1285 Handle e(THREAD, PENDING_EXCEPTION);
1286 CLEAR_PENDING_EXCEPTION;
1287 {
1288 EXCEPTION_MARK;
1289 add_initialization_error(THREAD, e);
1290 // Locks object, set state, and notify all waiting threads
1291 set_initialization_state_and_notify(initialization_error, THREAD);
1292 CLEAR_PENDING_EXCEPTION;
1293 }
1294 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1295 THROW_OOP(e());
1296 }
1297 }
1298
1299
1300 // Step 8
1301 {
1302 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1303 if (class_initializer() != nullptr) {
1304 // Timer includes any side effects of class initialization (resolution,
1305 // etc), but not recursive entry into call_class_initializer().
1306 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1307 ClassLoader::perf_class_init_selftime(),
1308 ClassLoader::perf_classes_inited(),
1309 jt->get_thread_stat()->perf_recursion_counts_addr(),
1310 jt->get_thread_stat()->perf_timers_addr(),
1311 PerfClassTraceTime::CLASS_CLINIT);
1312 call_class_initializer(THREAD);
1313 } else {
1314 // The elapsed time is so small it's not worth counting.
1315 if (UsePerfData) {
1316 ClassLoader::perf_classes_inited()->inc();
1317 }
1318 call_class_initializer(THREAD);
1319 }
1320 }
1321
1322 // Step 9
1323 if (!HAS_PENDING_EXCEPTION) {
1324 set_initialization_state_and_notify(fully_initialized, CHECK);
1325 debug_only(vtable().verify(tty, true);)
1326 }
1327 else {
1328 // Step 10 and 11
1329 Handle e(THREAD, PENDING_EXCEPTION);
1330 CLEAR_PENDING_EXCEPTION;
1331 // JVMTI has already reported the pending exception
1332 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1333 JvmtiExport::clear_detected_exception(jt);
1334 {
1335 EXCEPTION_MARK;
1336 add_initialization_error(THREAD, e);
1337 set_initialization_state_and_notify(initialization_error, THREAD);
1338 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1339 // JVMTI has already reported the pending exception
1340 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1341 JvmtiExport::clear_detected_exception(jt);
1342 }
1343 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1344 if (e->is_a(vmClasses::Error_klass())) {
1345 THROW_OOP(e());
1346 } else {
1347 JavaCallArguments args(e);
1348 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1349 vmSymbols::throwable_void_signature(),
1350 &args);
1351 }
1352 }
1353 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1354 }
1355
1356
1357 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1358 Handle h_init_lock(THREAD, init_lock());
1359 if (h_init_lock() != nullptr) {
1360 ObjectLocker ol(h_init_lock, THREAD);
1361 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1362 set_init_state(state);
1363 fence_and_clear_init_lock();
1364 ol.notify_all(CHECK);
1365 } else {
1366 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1367 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1368 set_init_state(state);
1369 }
1370 }
1371
1372 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1373 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1374 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1375 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1376
1377 DeoptimizationScope deopt_scope;
1378 {
1379 MutexLocker ml(current, Compile_lock);
1380
1381 set_init_state(InstanceKlass::loaded);
1382 // make sure init_state store is already done.
1383 // The compiler reads the hierarchy outside of the Compile_lock.
1384 // Access ordering is used to add to hierarchy.
1385
1386 // Link into hierarchy.
1387 append_to_sibling_list(); // add to superklass/sibling list
1388 process_interfaces(); // handle all "implements" declarations
1389
1390 // Now mark all code that depended on old class hierarchy.
1391 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1392 if (Universe::is_fully_initialized()) {
1393 CodeCache::mark_dependents_on(&deopt_scope, this);
1394 }
1395 }
1396 // Perform the deopt handshake outside Compile_lock.
1397 deopt_scope.deoptimize_marked();
1398 }
1399
1400
1401 InstanceKlass* InstanceKlass::implementor() const {
1402 InstanceKlass* volatile* ik = adr_implementor();
1403 if (ik == nullptr) {
1404 return nullptr;
1405 } else {
1406 // This load races with inserts, and therefore needs acquire.
1407 InstanceKlass* ikls = Atomic::load_acquire(ik);
1408 if (ikls != nullptr && !ikls->is_loader_alive()) {
1409 return nullptr; // don't return unloaded class
1410 } else {
1411 return ikls;
1412 }
1413 }
1414 }
1415
1416
1417 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1418 assert_locked_or_safepoint(Compile_lock);
1419 assert(is_interface(), "not interface");
1420 InstanceKlass* volatile* addr = adr_implementor();
1421 assert(addr != nullptr, "null addr");
1422 if (addr != nullptr) {
1423 Atomic::release_store(addr, ik);
1424 }
1425 }
1426
1427 int InstanceKlass::nof_implementors() const {
1428 InstanceKlass* ik = implementor();
1429 if (ik == nullptr) {
1430 return 0;
1431 } else if (ik != this) {
1432 return 1;
1433 } else {
1434 return 2;
1435 }
1436 }
1437
1438 // The embedded _implementor field can only record one implementor.
1439 // When there are more than one implementors, the _implementor field
1440 // is set to the interface Klass* itself. Following are the possible
1441 // values for the _implementor field:
1442 // null - no implementor
1443 // implementor Klass* - one implementor
1444 // self - more than one implementor
1445 //
1446 // The _implementor field only exists for interfaces.
1447 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1448 if (Universe::is_fully_initialized()) {
1449 assert_lock_strong(Compile_lock);
1450 }
1451 assert(is_interface(), "not interface");
1452 // Filter out my subinterfaces.
1453 // (Note: Interfaces are never on the subklass list.)
1454 if (ik->is_interface()) return;
1455
1456 // Filter out subclasses whose supers already implement me.
1457 // (Note: CHA must walk subclasses of direct implementors
1458 // in order to locate indirect implementors.)
1459 InstanceKlass* super_ik = ik->java_super();
1460 if (super_ik != nullptr && super_ik->implements_interface(this))
1461 // We only need to check one immediate superclass, since the
1462 // implements_interface query looks at transitive_interfaces.
1463 // Any supers of the super have the same (or fewer) transitive_interfaces.
1464 return;
1465
1466 InstanceKlass* iklass = implementor();
1467 if (iklass == nullptr) {
1468 set_implementor(ik);
1469 } else if (iklass != this && iklass != ik) {
1470 // There is already an implementor. Use itself as an indicator of
1471 // more than one implementors.
1472 set_implementor(this);
1473 }
1474
1475 // The implementor also implements the transitive_interfaces
1476 for (int index = 0; index < local_interfaces()->length(); index++) {
1477 local_interfaces()->at(index)->add_implementor(ik);
1478 }
1479 }
1480
1481 void InstanceKlass::init_implementor() {
1482 if (is_interface()) {
1483 set_implementor(nullptr);
1484 }
1485 }
1486
1487
1488 void InstanceKlass::process_interfaces() {
1489 // link this class into the implementors list of every interface it implements
1490 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1491 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1492 InstanceKlass* interf = local_interfaces()->at(i);
1493 assert(interf->is_interface(), "expected interface");
1494 interf->add_implementor(this);
1495 }
1496 }
1497
1498 bool InstanceKlass::can_be_primary_super_slow() const {
1499 if (is_interface())
1500 return false;
1501 else
1502 return Klass::can_be_primary_super_slow();
1503 }
1504
1505 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1506 Array<InstanceKlass*>* transitive_interfaces) {
1507 // The secondaries are the implemented interfaces.
1508 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1509 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1510 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1511 int num_secondaries = num_extra_slots + interfaces->length();
1512 if (num_secondaries == 0) {
1513 // Must share this for correct bootstrapping!
1514 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1515 return nullptr;
1516 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1517 // We will reuse the transitive interfaces list if we're certain
1518 // it's in hash order.
1519 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1520 set_secondary_supers(interfaces, bitmap);
1521 return nullptr;
1522 }
1523 // Copy transitive interfaces to a temporary growable array to be constructed
1524 // into the secondary super list with extra slots.
1525 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1526 for (int i = 0; i < interfaces->length(); i++) {
1527 secondaries->push(interfaces->at(i));
1528 }
1529 return secondaries;
1530 }
1531
1532 bool InstanceKlass::implements_interface(Klass* k) const {
1533 if (this == k) return true;
1534 assert(k->is_interface(), "should be an interface class");
1535 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1536 if (transitive_interfaces()->at(i) == k) {
1537 return true;
1538 }
1539 }
1540 return false;
1541 }
1542
1543 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1544 // Verify direct super interface
1545 if (this == k) return true;
1546 assert(k->is_interface(), "should be an interface class");
1547 for (int i = 0; i < local_interfaces()->length(); i++) {
1548 if (local_interfaces()->at(i) == k) {
1549 return true;
1550 }
1551 }
1552 return false;
1553 }
1554
1555 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1556 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1557 size_t size = objArrayOopDesc::object_size(length);
1558 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1559 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1560 /* do_zero */ true, CHECK_NULL);
1561 return o;
1562 }
1563
1564 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1565 if (TraceFinalizerRegistration) {
1566 tty->print("Registered ");
1567 i->print_value_on(tty);
1568 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1569 }
1570 instanceHandle h_i(THREAD, i);
1571 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1572 JavaValue result(T_VOID);
1573 JavaCallArguments args(h_i);
1574 methodHandle mh(THREAD, Universe::finalizer_register_method());
1575 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1576 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1577 return h_i();
1578 }
1579
1580 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1581 assert(!is_abstract() && !is_interface(), "Should not create this object");
1582 size_t size = size_helper(); // Query before forming handle.
1583 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1584 }
1585
1586 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1587 Klass* k = java_lang_Class::as_Klass(java_class);
1588 if (k == nullptr) {
1589 ResourceMark rm(THREAD);
1590 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1591 }
1592 InstanceKlass* ik = cast(k);
1593 ik->check_valid_for_instantiation(false, CHECK_NULL);
1594 ik->initialize(CHECK_NULL);
1595 return ik->allocate_instance(THREAD);
1596 }
1597
1598 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1599 return instanceHandle(THREAD, allocate_instance(THREAD));
1600 }
1601
1602 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1603 if (is_interface() || is_abstract()) {
1604 ResourceMark rm(THREAD);
1605 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1606 : vmSymbols::java_lang_InstantiationException(), external_name());
1607 }
1608 if (this == vmClasses::Class_klass()) {
1609 ResourceMark rm(THREAD);
1610 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1611 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1612 }
1613 }
1614
1615 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1616 // Need load-acquire for lock-free read
1617 if (array_klasses_acquire() == nullptr) {
1618
1619 // Recursively lock array allocation
1620 RecursiveLocker rl(MultiArray_lock, THREAD);
1621
1622 // Check if another thread created the array klass while we were waiting for the lock.
1623 if (array_klasses() == nullptr) {
1624 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1625 // use 'release' to pair with lock-free load
1626 release_set_array_klasses(k);
1627 }
1628 }
1629
1630 // array_klasses() will always be set at this point
1631 ObjArrayKlass* ak = array_klasses();
1632 assert(ak != nullptr, "should be set");
1633 return ak->array_klass(n, THREAD);
1634 }
1635
1636 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1637 // Need load-acquire for lock-free read
1638 ObjArrayKlass* oak = array_klasses_acquire();
1639 if (oak == nullptr) {
1640 return nullptr;
1641 } else {
1642 return oak->array_klass_or_null(n);
1643 }
1644 }
1645
1646 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1647 return array_klass(1, THREAD);
1648 }
1649
1650 ArrayKlass* InstanceKlass::array_klass_or_null() {
1651 return array_klass_or_null(1);
1652 }
1653
1654 static int call_class_initializer_counter = 0; // for debugging
1655
1656 Method* InstanceKlass::class_initializer() const {
1657 Method* clinit = find_method(
1658 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1659 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1660 return clinit;
1661 }
1662 return nullptr;
1663 }
1664
1665 void InstanceKlass::call_class_initializer(TRAPS) {
1666 if (ReplayCompiles &&
1667 (ReplaySuppressInitializers == 1 ||
1668 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1669 // Hide the existence of the initializer for the purpose of replaying the compile
1670 return;
1671 }
1672
1673 #if INCLUDE_CDS
1674 // This is needed to ensure the consistency of the archived heap objects.
1675 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1676 AOTClassInitializer::call_runtime_setup(THREAD, this);
1677 return;
1678 } else if (has_archived_enum_objs()) {
1679 assert(is_shared(), "must be");
1680 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1681 if (initialized) {
1682 return;
1683 }
1684 }
1685 #endif
1686
1687 methodHandle h_method(THREAD, class_initializer());
1688 assert(!is_initialized(), "we cannot initialize twice");
1689 LogTarget(Info, class, init) lt;
1690 if (lt.is_enabled()) {
1691 ResourceMark rm(THREAD);
1692 LogStream ls(lt);
1693 ls.print("%d Initializing ", call_class_initializer_counter++);
1694 name()->print_value_on(&ls);
1695 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1696 h_method() == nullptr ? "(no method)" : "", p2i(this),
1697 THREAD->name());
1698 }
1699 if (h_method() != nullptr) {
1700 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1701 JavaCallArguments args; // No arguments
1702 JavaValue result(T_VOID);
1703 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1704 }
1705 }
1706
1707 // If a class that implements this interface is initialized, is the JVM required
1708 // to first execute a <clinit> method declared in this interface,
1709 // or (if also_check_supers==true) any of the super types of this interface?
1710 //
1711 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1712 // an interface, then let SC be its superclass and let SI1, ..., SIn
1713 // be all superinterfaces of C (whether direct or indirect) that
1714 // declare at least one non-abstract, non-static method.
1715 //
1716 // So when an interface is initialized, it does not look at its
1717 // supers. But a proper class will ensure that all of its supers have
1718 // run their <clinit> methods, except that it disregards interfaces
1719 // that lack a non-static concrete method (i.e., a default method).
1720 // Therefore, you should probably call this method only when the
1721 // current class is a super of some proper class, not an interface.
1722 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1723 assert(is_interface(), "must be");
1724
1725 if (!has_nonstatic_concrete_methods()) {
1726 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1727 return false;
1728 }
1729
1730 // JVMS 5.5. Initialization
1731 // ...If C is an interface that declares a non-abstract,
1732 // non-static method, the initialization of a class that
1733 // implements C directly or indirectly.
1734 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1735 return true;
1736 }
1737 if (also_check_supers) {
1738 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1739 for (int i = 0; i < all_ifs->length(); ++i) {
1740 InstanceKlass* super_intf = all_ifs->at(i);
1741 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1742 return true;
1743 }
1744 }
1745 }
1746 return false;
1747 }
1748
1749 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1750 InterpreterOopMap* entry_for) {
1751 // Lazily create the _oop_map_cache at first request.
1752 // Load_acquire is needed to safely get instance published with CAS by another thread.
1753 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1754 if (oop_map_cache == nullptr) {
1755 // Try to install new instance atomically.
1756 oop_map_cache = new OopMapCache();
1757 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1758 if (other != nullptr) {
1759 // Someone else managed to install before us, ditch local copy and use the existing one.
1760 delete oop_map_cache;
1761 oop_map_cache = other;
1762 }
1763 }
1764 // _oop_map_cache is constant after init; lookup below does its own locking.
1765 oop_map_cache->lookup(method, bci, entry_for);
1766 }
1767
1768 bool InstanceKlass::contains_field_offset(int offset) {
1769 fieldDescriptor fd;
1770 return find_field_from_offset(offset, false, &fd);
1771 }
1772
1773 FieldInfo InstanceKlass::field(int index) const {
1774 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1775 if (fs.index() == index) {
1776 return fs.to_FieldInfo();
1777 }
1778 }
1779 fatal("Field not found");
1780 return FieldInfo();
1781 }
1782
1783 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1784 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1785 Symbol* f_name = fs.name();
1786 Symbol* f_sig = fs.signature();
1787 if (f_name == name && f_sig == sig) {
1788 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1789 return true;
1790 }
1791 }
1792 return false;
1793 }
1794
1795
1796 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1797 const int n = local_interfaces()->length();
1798 for (int i = 0; i < n; i++) {
1799 Klass* intf1 = local_interfaces()->at(i);
1800 assert(intf1->is_interface(), "just checking type");
1801 // search for field in current interface
1802 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1803 assert(fd->is_static(), "interface field must be static");
1804 return intf1;
1805 }
1806 // search for field in direct superinterfaces
1807 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1808 if (intf2 != nullptr) return intf2;
1809 }
1810 // otherwise field lookup fails
1811 return nullptr;
1812 }
1813
1814
1815 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1816 // search order according to newest JVM spec (5.4.3.2, p.167).
1817 // 1) search for field in current klass
1818 if (find_local_field(name, sig, fd)) {
1819 return const_cast<InstanceKlass*>(this);
1820 }
1821 // 2) search for field recursively in direct superinterfaces
1822 { Klass* intf = find_interface_field(name, sig, fd);
1823 if (intf != nullptr) return intf;
1824 }
1825 // 3) apply field lookup recursively if superclass exists
1826 { Klass* supr = super();
1827 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1828 }
1829 // 4) otherwise field lookup fails
1830 return nullptr;
1831 }
1832
1833
1834 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1835 // search order according to newest JVM spec (5.4.3.2, p.167).
1836 // 1) search for field in current klass
1837 if (find_local_field(name, sig, fd)) {
1838 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1839 }
1840 // 2) search for field recursively in direct superinterfaces
1841 if (is_static) {
1842 Klass* intf = find_interface_field(name, sig, fd);
1843 if (intf != nullptr) return intf;
1844 }
1845 // 3) apply field lookup recursively if superclass exists
1846 { Klass* supr = super();
1847 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1848 }
1849 // 4) otherwise field lookup fails
1850 return nullptr;
1851 }
1852
1853
1854 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1855 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1856 if (fs.offset() == offset) {
1857 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1858 if (fd->is_static() == is_static) return true;
1859 }
1860 }
1861 return false;
1862 }
1863
1864
1865 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1866 Klass* klass = const_cast<InstanceKlass*>(this);
1867 while (klass != nullptr) {
1868 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1869 return true;
1870 }
1871 klass = klass->super();
1872 }
1873 return false;
1874 }
1875
1876
1877 void InstanceKlass::methods_do(void f(Method* method)) {
1878 // Methods aren't stable until they are loaded. This can be read outside
1879 // a lock through the ClassLoaderData for profiling
1880 // Redefined scratch classes are on the list and need to be cleaned
1881 if (!is_loaded() && !is_scratch_class()) {
1882 return;
1883 }
1884
1885 int len = methods()->length();
1886 for (int index = 0; index < len; index++) {
1887 Method* m = methods()->at(index);
1888 assert(m->is_method(), "must be method");
1889 f(m);
1890 }
1891 }
1892
1893
1894 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1895 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1896 if (fs.access_flags().is_static()) {
1897 fieldDescriptor& fd = fs.field_descriptor();
1898 cl->do_field(&fd);
1899 }
1900 }
1901 }
1902
1903
1904 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1905 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1906 if (fs.access_flags().is_static()) {
1907 fieldDescriptor& fd = fs.field_descriptor();
1908 f(&fd, mirror, CHECK);
1909 }
1910 }
1911 }
1912
1913 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1914 InstanceKlass* super = superklass();
1915 if (super != nullptr) {
1916 super->do_nonstatic_fields(cl);
1917 }
1918 fieldDescriptor fd;
1919 int length = java_fields_count();
1920 for (int i = 0; i < length; i += 1) {
1921 fd.reinitialize(this, i);
1922 if (!fd.is_static()) {
1923 cl->do_field(&fd);
1924 }
1925 }
1926 }
1927
1928 // first in Pair is offset, second is index.
1929 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1930 return a->first - b->first;
1931 }
1932
1933 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1934 InstanceKlass* super = superklass();
1935 if (super != nullptr) {
1936 super->print_nonstatic_fields(cl);
1937 }
1938 ResourceMark rm;
1939 fieldDescriptor fd;
1940 // In DebugInfo nonstatic fields are sorted by offset.
1941 GrowableArray<Pair<int,int> > fields_sorted;
1942 int i = 0;
1943 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1944 if (!fs.access_flags().is_static()) {
1945 fd = fs.field_descriptor();
1946 Pair<int,int> f(fs.offset(), fs.index());
1947 fields_sorted.push(f);
1948 i++;
1949 }
1950 }
1951 if (i > 0) {
1952 int length = i;
1953 assert(length == fields_sorted.length(), "duh");
1954 fields_sorted.sort(compare_fields_by_offset);
1955 for (int i = 0; i < length; i++) {
1956 fd.reinitialize(this, fields_sorted.at(i).second);
1957 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1958 cl->do_field(&fd);
1959 }
1960 }
1961 }
1962
1963 #ifdef ASSERT
1964 static int linear_search(const Array<Method*>* methods,
1965 const Symbol* name,
1966 const Symbol* signature) {
1967 const int len = methods->length();
1968 for (int index = 0; index < len; index++) {
1969 const Method* const m = methods->at(index);
1970 assert(m->is_method(), "must be method");
1971 if (m->signature() == signature && m->name() == name) {
1972 return index;
1973 }
1974 }
1975 return -1;
1976 }
1977 #endif
1978
1979 bool InstanceKlass::_disable_method_binary_search = false;
1980
1981 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1982 int len = methods->length();
1983 int l = 0;
1984 int h = len - 1;
1985 while (l <= h) {
1986 Method* m = methods->at(l);
1987 if (m->name() == name) {
1988 return l;
1989 }
1990 l++;
1991 }
1992 return -1;
1993 }
1994
1995 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1996 if (_disable_method_binary_search) {
1997 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1998 // At the final stage of dynamic dumping, the methods array may not be sorted
1999 // by ascending addresses of their names, so we can't use binary search anymore.
2000 // However, methods with the same name are still laid out consecutively inside the
2001 // methods array, so let's look for the first one that matches.
2002 return linear_search(methods, name);
2003 }
2004
2005 int len = methods->length();
2006 int l = 0;
2007 int h = len - 1;
2008
2009 // methods are sorted by ascending addresses of their names, so do binary search
2010 while (l <= h) {
2011 int mid = (l + h) >> 1;
2012 Method* m = methods->at(mid);
2013 assert(m->is_method(), "must be method");
2014 int res = m->name()->fast_compare(name);
2015 if (res == 0) {
2016 return mid;
2017 } else if (res < 0) {
2018 l = mid + 1;
2019 } else {
2020 h = mid - 1;
2021 }
2022 }
2023 return -1;
2024 }
2025
2026 // find_method looks up the name/signature in the local methods array
2027 Method* InstanceKlass::find_method(const Symbol* name,
2028 const Symbol* signature) const {
2029 return find_method_impl(name, signature,
2030 OverpassLookupMode::find,
2031 StaticLookupMode::find,
2032 PrivateLookupMode::find);
2033 }
2034
2035 Method* InstanceKlass::find_method_impl(const Symbol* name,
2036 const Symbol* signature,
2037 OverpassLookupMode overpass_mode,
2038 StaticLookupMode static_mode,
2039 PrivateLookupMode private_mode) const {
2040 return InstanceKlass::find_method_impl(methods(),
2041 name,
2042 signature,
2043 overpass_mode,
2044 static_mode,
2045 private_mode);
2046 }
2047
2048 // find_instance_method looks up the name/signature in the local methods array
2049 // and skips over static methods
2050 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2051 const Symbol* name,
2052 const Symbol* signature,
2053 PrivateLookupMode private_mode) {
2054 Method* const meth = InstanceKlass::find_method_impl(methods,
2055 name,
2056 signature,
2057 OverpassLookupMode::find,
2058 StaticLookupMode::skip,
2059 private_mode);
2060 assert(((meth == nullptr) || !meth->is_static()),
2061 "find_instance_method should have skipped statics");
2062 return meth;
2063 }
2064
2065 // find_instance_method looks up the name/signature in the local methods array
2066 // and skips over static methods
2067 Method* InstanceKlass::find_instance_method(const Symbol* name,
2068 const Symbol* signature,
2069 PrivateLookupMode private_mode) const {
2070 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2071 }
2072
2073 // Find looks up the name/signature in the local methods array
2074 // and filters on the overpass, static and private flags
2075 // This returns the first one found
2076 // note that the local methods array can have up to one overpass, one static
2077 // and one instance (private or not) with the same name/signature
2078 Method* InstanceKlass::find_local_method(const Symbol* name,
2079 const Symbol* signature,
2080 OverpassLookupMode overpass_mode,
2081 StaticLookupMode static_mode,
2082 PrivateLookupMode private_mode) const {
2083 return InstanceKlass::find_method_impl(methods(),
2084 name,
2085 signature,
2086 overpass_mode,
2087 static_mode,
2088 private_mode);
2089 }
2090
2091 // Find looks up the name/signature in the local methods array
2092 // and filters on the overpass, static and private flags
2093 // This returns the first one found
2094 // note that the local methods array can have up to one overpass, one static
2095 // and one instance (private or not) with the same name/signature
2096 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2097 const Symbol* name,
2098 const Symbol* signature,
2099 OverpassLookupMode overpass_mode,
2100 StaticLookupMode static_mode,
2101 PrivateLookupMode private_mode) {
2102 return InstanceKlass::find_method_impl(methods,
2103 name,
2104 signature,
2105 overpass_mode,
2106 static_mode,
2107 private_mode);
2108 }
2109
2110 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2111 const Symbol* name,
2112 const Symbol* signature) {
2113 return InstanceKlass::find_method_impl(methods,
2114 name,
2115 signature,
2116 OverpassLookupMode::find,
2117 StaticLookupMode::find,
2118 PrivateLookupMode::find);
2119 }
2120
2121 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2122 const Symbol* name,
2123 const Symbol* signature,
2124 OverpassLookupMode overpass_mode,
2125 StaticLookupMode static_mode,
2126 PrivateLookupMode private_mode) {
2127 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2128 return hit >= 0 ? methods->at(hit): nullptr;
2129 }
2130
2131 // true if method matches signature and conforms to skipping_X conditions.
2132 static bool method_matches(const Method* m,
2133 const Symbol* signature,
2134 bool skipping_overpass,
2135 bool skipping_static,
2136 bool skipping_private) {
2137 return ((m->signature() == signature) &&
2138 (!skipping_overpass || !m->is_overpass()) &&
2139 (!skipping_static || !m->is_static()) &&
2140 (!skipping_private || !m->is_private()));
2141 }
2142
2143 // Used directly for default_methods to find the index into the
2144 // default_vtable_indices, and indirectly by find_method
2145 // find_method_index looks in the local methods array to return the index
2146 // of the matching name/signature. If, overpass methods are being ignored,
2147 // the search continues to find a potential non-overpass match. This capability
2148 // is important during method resolution to prefer a static method, for example,
2149 // over an overpass method.
2150 // There is the possibility in any _method's array to have the same name/signature
2151 // for a static method, an overpass method and a local instance method
2152 // To correctly catch a given method, the search criteria may need
2153 // to explicitly skip the other two. For local instance methods, it
2154 // is often necessary to skip private methods
2155 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2156 const Symbol* name,
2157 const Symbol* signature,
2158 OverpassLookupMode overpass_mode,
2159 StaticLookupMode static_mode,
2160 PrivateLookupMode private_mode) {
2161 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2162 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2163 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2164 const int hit = quick_search(methods, name);
2165 if (hit != -1) {
2166 const Method* const m = methods->at(hit);
2167
2168 // Do linear search to find matching signature. First, quick check
2169 // for common case, ignoring overpasses if requested.
2170 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2171 return hit;
2172 }
2173
2174 // search downwards through overloaded methods
2175 int i;
2176 for (i = hit - 1; i >= 0; --i) {
2177 const Method* const m = methods->at(i);
2178 assert(m->is_method(), "must be method");
2179 if (m->name() != name) {
2180 break;
2181 }
2182 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2183 return i;
2184 }
2185 }
2186 // search upwards
2187 for (i = hit + 1; i < methods->length(); ++i) {
2188 const Method* const m = methods->at(i);
2189 assert(m->is_method(), "must be method");
2190 if (m->name() != name) {
2191 break;
2192 }
2193 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2194 return i;
2195 }
2196 }
2197 // not found
2198 #ifdef ASSERT
2199 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2200 linear_search(methods, name, signature);
2201 assert(-1 == index, "binary search should have found entry %d", index);
2202 #endif
2203 }
2204 return -1;
2205 }
2206
2207 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2208 return find_method_by_name(methods(), name, end);
2209 }
2210
2211 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2212 const Symbol* name,
2213 int* end_ptr) {
2214 assert(end_ptr != nullptr, "just checking");
2215 int start = quick_search(methods, name);
2216 int end = start + 1;
2217 if (start != -1) {
2218 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2219 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2220 *end_ptr = end;
2221 return start;
2222 }
2223 return -1;
2224 }
2225
2226 // uncached_lookup_method searches both the local class methods array and all
2227 // superclasses methods arrays, skipping any overpass methods in superclasses,
2228 // and possibly skipping private methods.
2229 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2230 const Symbol* signature,
2231 OverpassLookupMode overpass_mode,
2232 PrivateLookupMode private_mode) const {
2233 OverpassLookupMode overpass_local_mode = overpass_mode;
2234 const Klass* klass = this;
2235 while (klass != nullptr) {
2236 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2237 signature,
2238 overpass_local_mode,
2239 StaticLookupMode::find,
2240 private_mode);
2241 if (method != nullptr) {
2242 return method;
2243 }
2244 klass = klass->super();
2245 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2246 }
2247 return nullptr;
2248 }
2249
2250 #ifdef ASSERT
2251 // search through class hierarchy and return true if this class or
2252 // one of the superclasses was redefined
2253 bool InstanceKlass::has_redefined_this_or_super() const {
2254 const Klass* klass = this;
2255 while (klass != nullptr) {
2256 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2257 return true;
2258 }
2259 klass = klass->super();
2260 }
2261 return false;
2262 }
2263 #endif
2264
2265 // lookup a method in the default methods list then in all transitive interfaces
2266 // Do NOT return private or static methods
2267 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2268 Symbol* signature) const {
2269 Method* m = nullptr;
2270 if (default_methods() != nullptr) {
2271 m = find_method(default_methods(), name, signature);
2272 }
2273 // Look up interfaces
2274 if (m == nullptr) {
2275 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2276 }
2277 return m;
2278 }
2279
2280 // lookup a method in all the interfaces that this class implements
2281 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2282 // They should only be found in the initial InterfaceMethodRef
2283 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2284 Symbol* signature,
2285 DefaultsLookupMode defaults_mode) const {
2286 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2287 int num_ifs = all_ifs->length();
2288 InstanceKlass *ik = nullptr;
2289 for (int i = 0; i < num_ifs; i++) {
2290 ik = all_ifs->at(i);
2291 Method* m = ik->lookup_method(name, signature);
2292 if (m != nullptr && m->is_public() && !m->is_static() &&
2293 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2294 return m;
2295 }
2296 }
2297 return nullptr;
2298 }
2299
2300 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2301 :_st(st), _verbose(verbose) {
2302 ResourceMark rm;
2303 _st->print("%-18s ", "KlassAddr");
2304 _st->print("%-4s ", "Size");
2305 _st->print("%-20s ", "State");
2306 _st->print("%-7s ", "Flags");
2307 _st->print("%-5s ", "ClassName");
2308 _st->cr();
2309 }
2310
2311 void PrintClassClosure::do_klass(Klass* k) {
2312 ResourceMark rm;
2313 // klass pointer
2314 _st->print(PTR_FORMAT " ", p2i(k));
2315 // klass size
2316 _st->print("%4d ", k->size());
2317 // initialization state
2318 if (k->is_instance_klass()) {
2319 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2320 } else {
2321 _st->print("%-20s ","");
2322 }
2323 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2324 char buf[10];
2325 int i = 0;
2326 if (k->has_finalizer()) buf[i++] = 'F';
2327 if (k->is_instance_klass()) {
2328 InstanceKlass* ik = InstanceKlass::cast(k);
2329 if (ik->has_final_method()) buf[i++] = 'f';
2330 if (ik->is_rewritten()) buf[i++] = 'W';
2331 if (ik->is_contended()) buf[i++] = 'C';
2332 if (ik->has_been_redefined()) buf[i++] = 'R';
2333 if (ik->is_shared()) buf[i++] = 'S';
2334 }
2335 buf[i++] = '\0';
2336 _st->print("%-7s ", buf);
2337 // klass name
2338 _st->print("%-5s ", k->external_name());
2339 // end
2340 _st->cr();
2341 if (_verbose) {
2342 k->print_on(_st);
2343 }
2344 }
2345
2346 /* jni_id_for for jfieldIds only */
2347 JNIid* InstanceKlass::jni_id_for(int offset) {
2348 MutexLocker ml(JfieldIdCreation_lock);
2349 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2350 if (probe == nullptr) {
2351 // Allocate new static field identifier
2352 probe = new JNIid(this, offset, jni_ids());
2353 set_jni_ids(probe);
2354 }
2355 return probe;
2356 }
2357
2358 u2 InstanceKlass::enclosing_method_data(int offset) const {
2359 const Array<jushort>* const inner_class_list = inner_classes();
2360 if (inner_class_list == nullptr) {
2361 return 0;
2362 }
2363 const int length = inner_class_list->length();
2364 if (length % inner_class_next_offset == 0) {
2365 return 0;
2366 }
2367 const int index = length - enclosing_method_attribute_size;
2368 assert(offset < enclosing_method_attribute_size, "invalid offset");
2369 return inner_class_list->at(index + offset);
2370 }
2371
2372 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2373 u2 method_index) {
2374 Array<jushort>* inner_class_list = inner_classes();
2375 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2376 int length = inner_class_list->length();
2377 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2378 int index = length - enclosing_method_attribute_size;
2379 inner_class_list->at_put(
2380 index + enclosing_method_class_index_offset, class_index);
2381 inner_class_list->at_put(
2382 index + enclosing_method_method_index_offset, method_index);
2383 }
2384 }
2385
2386 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2387 if (method->is_old() && !method->is_obsolete()) {
2388 // If the method passed in is old (but not obsolete), use the current version.
2389 method = method_with_idnum((int)idnum);
2390 assert(method != nullptr, "old and but not obsolete, so should exist");
2391 }
2392 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2393 Atomic::release_store(&jmeths[idnum + 1], new_id);
2394 return new_id;
2395 }
2396
2397 // Lookup or create a jmethodID.
2398 // This code is called by the VMThread and JavaThreads so the
2399 // locking has to be done very carefully to avoid deadlocks
2400 // and/or other cache consistency problems.
2401 //
2402 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2403 Method* method = method_h();
2404 int idnum = method->method_idnum();
2405 jmethodID* jmeths = methods_jmethod_ids_acquire();
2406
2407 // We use a double-check locking idiom here because this cache is
2408 // performance sensitive. In the normal system, this cache only
2409 // transitions from null to non-null which is safe because we use
2410 // release_set_methods_jmethod_ids() to advertise the new cache.
2411 // A partially constructed cache should never be seen by a racing
2412 // thread. We also use release_store() to save a new jmethodID
2413 // in the cache so a partially constructed jmethodID should never be
2414 // seen either. Cache reads of existing jmethodIDs proceed without a
2415 // lock, but cache writes of a new jmethodID requires uniqueness and
2416 // creation of the cache itself requires no leaks so a lock is
2417 // acquired in those two cases.
2418 //
2419 // If the RedefineClasses() API has been used, then this cache grows
2420 // in the redefinition safepoint.
2421
2422 if (jmeths == nullptr) {
2423 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2424 jmeths = methods_jmethod_ids_acquire();
2425 // Still null?
2426 if (jmeths == nullptr) {
2427 size_t size = idnum_allocated_count();
2428 assert(size > (size_t)idnum, "should already have space");
2429 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2430 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2431 // cache size is stored in element[0], other elements offset by one
2432 jmeths[0] = (jmethodID)size;
2433 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2434
2435 // publish jmeths
2436 release_set_methods_jmethod_ids(jmeths);
2437 return new_id;
2438 }
2439 }
2440
2441 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2442 if (id == nullptr) {
2443 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2444 id = jmeths[idnum + 1];
2445 // Still null?
2446 if (id == nullptr) {
2447 return update_jmethod_id(jmeths, method, idnum);
2448 }
2449 }
2450 return id;
2451 }
2452
2453 void InstanceKlass::update_methods_jmethod_cache() {
2454 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2455 jmethodID* cache = _methods_jmethod_ids;
2456 if (cache != nullptr) {
2457 size_t size = idnum_allocated_count();
2458 size_t old_size = (size_t)cache[0];
2459 if (old_size < size + 1) {
2460 // Allocate a larger one and copy entries to the new one.
2461 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2462 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2463 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2464 // The cache size is stored in element[0]; the other elements are offset by one.
2465 new_cache[0] = (jmethodID)size;
2466
2467 for (int i = 1; i <= (int)old_size; i++) {
2468 new_cache[i] = cache[i];
2469 }
2470 _methods_jmethod_ids = new_cache;
2471 FREE_C_HEAP_ARRAY(jmethodID, cache);
2472 }
2473 }
2474 }
2475
2476 // Figure out how many jmethodIDs haven't been allocated, and make
2477 // sure space for them is pre-allocated. This makes getting all
2478 // method ids much, much faster with classes with more than 8
2479 // methods, and has a *substantial* effect on performance with jvmti
2480 // code that loads all jmethodIDs for all classes.
2481 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2482 int new_jmeths = 0;
2483 int length = methods()->length();
2484 for (int index = start_offset; index < length; index++) {
2485 Method* m = methods()->at(index);
2486 jmethodID id = m->find_jmethod_id_or_null();
2487 if (id == nullptr) {
2488 new_jmeths++;
2489 }
2490 }
2491 if (new_jmeths != 0) {
2492 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2493 }
2494 }
2495
2496 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2497 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2498 int idnum = method->method_idnum();
2499 jmethodID* jmeths = methods_jmethod_ids_acquire();
2500 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2501 }
2502
2503 inline DependencyContext InstanceKlass::dependencies() {
2504 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2505 return dep_context;
2506 }
2507
2508 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2509 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2510 }
2511
2512 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2513 dependencies().add_dependent_nmethod(nm);
2514 }
2515
2516 void InstanceKlass::clean_dependency_context() {
2517 dependencies().clean_unloading_dependents();
2518 }
2519
2520 #ifndef PRODUCT
2521 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2522 dependencies().print_dependent_nmethods(verbose);
2523 }
2524
2525 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2526 return dependencies().is_dependent_nmethod(nm);
2527 }
2528 #endif //PRODUCT
2529
2530 void InstanceKlass::clean_weak_instanceklass_links() {
2531 clean_implementors_list();
2532 clean_method_data();
2533 }
2534
2535 void InstanceKlass::clean_implementors_list() {
2536 assert(is_loader_alive(), "this klass should be live");
2537 if (is_interface()) {
2538 assert (ClassUnloading, "only called for ClassUnloading");
2539 for (;;) {
2540 // Use load_acquire due to competing with inserts
2541 InstanceKlass* volatile* iklass = adr_implementor();
2542 assert(iklass != nullptr, "Klass must not be null");
2543 InstanceKlass* impl = Atomic::load_acquire(iklass);
2544 if (impl != nullptr && !impl->is_loader_alive()) {
2545 // null this field, might be an unloaded instance klass or null
2546 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2547 // Successfully unlinking implementor.
2548 if (log_is_enabled(Trace, class, unload)) {
2549 ResourceMark rm;
2550 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2551 }
2552 return;
2553 }
2554 } else {
2555 return;
2556 }
2557 }
2558 }
2559 }
2560
2561 void InstanceKlass::clean_method_data() {
2562 for (int m = 0; m < methods()->length(); m++) {
2563 MethodData* mdo = methods()->at(m)->method_data();
2564 if (mdo != nullptr) {
2565 mdo->clean_method_data(/*always_clean*/false);
2566 }
2567 }
2568 }
2569
2570 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2571 Klass::metaspace_pointers_do(it);
2572
2573 if (log_is_enabled(Trace, cds)) {
2574 ResourceMark rm;
2575 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2576 }
2577
2578 it->push(&_annotations);
2579 it->push((Klass**)&_array_klasses);
2580 if (!is_rewritten()) {
2581 it->push(&_constants, MetaspaceClosure::_writable);
2582 } else {
2583 it->push(&_constants);
2584 }
2585 it->push(&_inner_classes);
2586 #if INCLUDE_JVMTI
2587 it->push(&_previous_versions);
2588 #endif
2589 #if INCLUDE_CDS
2590 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2591 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2592 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2593 // The length check on the _methods is necessary because classes which don't have any
2594 // methods share the Universe::_the_empty_method_array which is in the RO region.
2595 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2596 // To handle jsr bytecode, new Method* maybe stored into _methods
2597 it->push(&_methods, MetaspaceClosure::_writable);
2598 } else {
2599 #endif
2600 it->push(&_methods);
2601 #if INCLUDE_CDS
2602 }
2603 #endif
2604 it->push(&_default_methods);
2605 it->push(&_local_interfaces);
2606 it->push(&_transitive_interfaces);
2607 it->push(&_method_ordering);
2608 if (!is_rewritten()) {
2609 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2610 } else {
2611 it->push(&_default_vtable_indices);
2612 }
2613
2614 it->push(&_fieldinfo_stream);
2615 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2616 it->push(&_fields_status, MetaspaceClosure::_writable);
2617
2618 if (itable_length() > 0) {
2619 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2620 int method_table_offset_in_words = ioe->offset()/wordSize;
2621 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2622
2623 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2624 / itableOffsetEntry::size();
2625
2626 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2627 if (ioe->interface_klass() != nullptr) {
2628 it->push(ioe->interface_klass_addr());
2629 itableMethodEntry* ime = ioe->first_method_entry(this);
2630 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2631 for (int index = 0; index < n; index ++) {
2632 it->push(ime[index].method_addr());
2633 }
2634 }
2635 }
2636 }
2637
2638 it->push(&_nest_host);
2639 it->push(&_nest_members);
2640 it->push(&_permitted_subclasses);
2641 it->push(&_record_components);
2642 }
2643
2644 #if INCLUDE_CDS
2645 void InstanceKlass::remove_unshareable_info() {
2646
2647 if (is_linked()) {
2648 assert(can_be_verified_at_dumptime(), "must be");
2649 // Remember this so we can avoid walking the hierarchy at runtime.
2650 set_verified_at_dump_time();
2651 }
2652
2653 Klass::remove_unshareable_info();
2654
2655 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2656 // Classes are attempted to link during dumping and may fail,
2657 // but these classes are still in the dictionary and class list in CLD.
2658 // If the class has failed verification, there is nothing else to remove.
2659 return;
2660 }
2661
2662 // Reset to the 'allocated' state to prevent any premature accessing to
2663 // a shared class at runtime while the class is still being loaded and
2664 // restored. A class' init_state is set to 'loaded' at runtime when it's
2665 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2666 _init_state = allocated;
2667
2668 { // Otherwise this needs to take out the Compile_lock.
2669 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2670 init_implementor();
2671 }
2672
2673 // Call remove_unshareable_info() on other objects that belong to this class, except
2674 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2675 // ArchiveBuilder::make_klasses_shareable(),
2676
2677 for (int i = 0; i < methods()->length(); i++) {
2678 Method* m = methods()->at(i);
2679 m->remove_unshareable_info();
2680 }
2681
2682 // do array classes also.
2683 if (array_klasses() != nullptr) {
2684 array_klasses()->remove_unshareable_info();
2685 }
2686
2687 // These are not allocated from metaspace. They are safe to set to null.
2688 _source_debug_extension = nullptr;
2689 _dep_context = nullptr;
2690 _osr_nmethods_head = nullptr;
2691 #if INCLUDE_JVMTI
2692 _breakpoints = nullptr;
2693 _previous_versions = nullptr;
2694 _cached_class_file = nullptr;
2695 _jvmti_cached_class_field_map = nullptr;
2696 #endif
2697
2698 _init_thread = nullptr;
2699 _methods_jmethod_ids = nullptr;
2700 _jni_ids = nullptr;
2701 _oop_map_cache = nullptr;
2702 if (CDSConfig::is_dumping_invokedynamic() && HeapShared::is_lambda_proxy_klass(this)) {
2703 // keep _nest_host
2704 } else {
2705 // clear _nest_host to ensure re-load at runtime
2706 _nest_host = nullptr;
2707 }
2708 init_shared_package_entry();
2709 _dep_context_last_cleaned = 0;
2710
2711 remove_unshareable_flags();
2712 }
2713
2714 void InstanceKlass::remove_unshareable_flags() {
2715 // clear all the flags/stats that shouldn't be in the archived version
2716 assert(!is_scratch_class(), "must be");
2717 assert(!has_been_redefined(), "must be");
2718 #if INCLUDE_JVMTI
2719 set_is_being_redefined(false);
2720 #endif
2721 set_has_resolved_methods(false);
2722 }
2723
2724 void InstanceKlass::remove_java_mirror() {
2725 Klass::remove_java_mirror();
2726
2727 // do array classes also.
2728 if (array_klasses() != nullptr) {
2729 array_klasses()->remove_java_mirror();
2730 }
2731 }
2732
2733 void InstanceKlass::init_shared_package_entry() {
2734 assert(CDSConfig::is_dumping_archive(), "must be");
2735 #if !INCLUDE_CDS_JAVA_HEAP
2736 _package_entry = nullptr;
2737 #else
2738 if (CDSConfig::is_dumping_full_module_graph()) {
2739 if (is_shared_unregistered_class()) {
2740 _package_entry = nullptr;
2741 } else {
2742 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2743 }
2744 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2745 CDSConfig::is_using_full_module_graph() &&
2746 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2747 // _package_entry is an archived package in the base archive. Leave it as is.
2748 } else {
2749 _package_entry = nullptr;
2750 }
2751 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2752 #endif
2753 }
2754
2755 void InstanceKlass::compute_has_loops_flag_for_methods() {
2756 Array<Method*>* methods = this->methods();
2757 for (int index = 0; index < methods->length(); ++index) {
2758 Method* m = methods->at(index);
2759 if (!m->is_overpass()) { // work around JDK-8305771
2760 m->compute_has_loops_flag();
2761 }
2762 }
2763 }
2764
2765 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2766 PackageEntry* pkg_entry, TRAPS) {
2767 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2768 // before the InstanceKlass is added to the SystemDictionary. Make
2769 // sure the current state is <loaded.
2770 assert(!is_loaded(), "invalid init state");
2771 assert(!shared_loading_failed(), "Must not try to load failed class again");
2772 set_package(loader_data, pkg_entry, CHECK);
2773 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2774
2775 Array<Method*>* methods = this->methods();
2776 int num_methods = methods->length();
2777 for (int index = 0; index < num_methods; ++index) {
2778 methods->at(index)->restore_unshareable_info(CHECK);
2779 }
2780 #if INCLUDE_JVMTI
2781 if (JvmtiExport::has_redefined_a_class()) {
2782 // Reinitialize vtable because RedefineClasses may have changed some
2783 // entries in this vtable for super classes so the CDS vtable might
2784 // point to old or obsolete entries. RedefineClasses doesn't fix up
2785 // vtables in the shared system dictionary, only the main one.
2786 // It also redefines the itable too so fix that too.
2787 // First fix any default methods that point to a super class that may
2788 // have been redefined.
2789 bool trace_name_printed = false;
2790 adjust_default_methods(&trace_name_printed);
2791 if (verified_at_dump_time()) {
2792 // Initialize vtable and itable for classes which can be verified at dump time.
2793 // Unlinked classes such as old classes with major version < 50 cannot be verified
2794 // at dump time.
2795 vtable().initialize_vtable();
2796 itable().initialize_itable();
2797 }
2798 }
2799 #endif // INCLUDE_JVMTI
2800
2801 // restore constant pool resolved references
2802 constants()->restore_unshareable_info(CHECK);
2803
2804 if (array_klasses() != nullptr) {
2805 // To get a consistent list of classes we need MultiArray_lock to ensure
2806 // array classes aren't observed while they are being restored.
2807 RecursiveLocker rl(MultiArray_lock, THREAD);
2808 assert(this == array_klasses()->bottom_klass(), "sanity");
2809 // Array classes have null protection domain.
2810 // --> see ArrayKlass::complete_create_array_klass()
2811 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2812 }
2813
2814 // Initialize @ValueBased class annotation if not already set in the archived klass.
2815 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2816 set_is_value_based();
2817 }
2818 }
2819
2820 // Check if a class or any of its supertypes has a version older than 50.
2821 // CDS will not perform verification of old classes during dump time because
2822 // without changing the old verifier, the verification constraint cannot be
2823 // retrieved during dump time.
2824 // Verification of archived old classes will be performed during run time.
2825 bool InstanceKlass::can_be_verified_at_dumptime() const {
2826 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2827 // This is a class that was dumped into the base archive, so we know
2828 // it was verified at dump time.
2829 return true;
2830 }
2831 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2832 return false;
2833 }
2834 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2835 return false;
2836 }
2837 Array<InstanceKlass*>* interfaces = local_interfaces();
2838 int len = interfaces->length();
2839 for (int i = 0; i < len; i++) {
2840 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2841 return false;
2842 }
2843 }
2844 return true;
2845 }
2846
2847 int InstanceKlass::shared_class_loader_type() const {
2848 if (is_shared_boot_class()) {
2849 return ClassLoader::BOOT_LOADER;
2850 } else if (is_shared_platform_class()) {
2851 return ClassLoader::PLATFORM_LOADER;
2852 } else if (is_shared_app_class()) {
2853 return ClassLoader::APP_LOADER;
2854 } else {
2855 return ClassLoader::OTHER;
2856 }
2857 }
2858 #endif // INCLUDE_CDS
2859
2860 #if INCLUDE_JVMTI
2861 static void clear_all_breakpoints(Method* m) {
2862 m->clear_all_breakpoints();
2863 }
2864 #endif
2865
2866 void InstanceKlass::unload_class(InstanceKlass* ik) {
2867
2868 if (ik->is_scratch_class()) {
2869 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2870 return;
2871 }
2872 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2873
2874 // Release dependencies.
2875 ik->dependencies().remove_all_dependents();
2876
2877 // notify the debugger
2878 if (JvmtiExport::should_post_class_unload()) {
2879 JvmtiExport::post_class_unload(ik);
2880 }
2881
2882 // notify ClassLoadingService of class unload
2883 ClassLoadingService::notify_class_unloaded(ik);
2884
2885 SystemDictionaryShared::handle_class_unloading(ik);
2886
2887 if (log_is_enabled(Info, class, unload)) {
2888 ResourceMark rm;
2889 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2890 }
2891
2892 Events::log_class_unloading(Thread::current(), ik);
2893
2894 #if INCLUDE_JFR
2895 assert(ik != nullptr, "invariant");
2896 EventClassUnload event;
2897 event.set_unloadedClass(ik);
2898 event.set_definingClassLoader(ik->class_loader_data());
2899 event.commit();
2900 #endif
2901 }
2902
2903 static void method_release_C_heap_structures(Method* m) {
2904 m->release_C_heap_structures();
2905 }
2906
2907 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2908 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2909 // Clean up C heap
2910 Klass::release_C_heap_structures();
2911
2912 // Deallocate and call destructors for MDO mutexes
2913 if (release_sub_metadata) {
2914 methods_do(method_release_C_heap_structures);
2915 }
2916
2917 // Deallocate oop map cache
2918 if (_oop_map_cache != nullptr) {
2919 delete _oop_map_cache;
2920 _oop_map_cache = nullptr;
2921 }
2922
2923 // Deallocate JNI identifiers for jfieldIDs
2924 JNIid::deallocate(jni_ids());
2925 set_jni_ids(nullptr);
2926
2927 jmethodID* jmeths = methods_jmethod_ids_acquire();
2928 if (jmeths != nullptr) {
2929 release_set_methods_jmethod_ids(nullptr);
2930 FreeHeap(jmeths);
2931 }
2932
2933 assert(_dep_context == nullptr,
2934 "dependencies should already be cleaned");
2935
2936 #if INCLUDE_JVMTI
2937 // Deallocate breakpoint records
2938 if (breakpoints() != nullptr) {
2939 methods_do(clear_all_breakpoints);
2940 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2941 }
2942
2943 // deallocate the cached class file
2944 if (_cached_class_file != nullptr) {
2945 os::free(_cached_class_file);
2946 _cached_class_file = nullptr;
2947 }
2948 #endif
2949
2950 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2951
2952 if (release_sub_metadata) {
2953 constants()->release_C_heap_structures();
2954 }
2955 }
2956
2957 // The constant pool is on stack if any of the methods are executing or
2958 // referenced by handles.
2959 bool InstanceKlass::on_stack() const {
2960 return _constants->on_stack();
2961 }
2962
2963 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2964 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2965 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2966
2967 // minor and major version numbers of class file
2968 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2969 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2970 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2971 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2972
2973 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2974 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2975 if (ik->constants()->version() == version) {
2976 return ik;
2977 }
2978 }
2979 return nullptr;
2980 }
2981
2982 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2983 if (array == nullptr) {
2984 _source_debug_extension = nullptr;
2985 } else {
2986 // Adding one to the attribute length in order to store a null terminator
2987 // character could cause an overflow because the attribute length is
2988 // already coded with an u4 in the classfile, but in practice, it's
2989 // unlikely to happen.
2990 assert((length+1) > length, "Overflow checking");
2991 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2992 for (int i = 0; i < length; i++) {
2993 sde[i] = array[i];
2994 }
2995 sde[length] = '\0';
2996 _source_debug_extension = sde;
2997 }
2998 }
2999
3000 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3001 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3002 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3003
3004 const char* InstanceKlass::signature_name() const {
3005
3006 // Get the internal name as a c string
3007 const char* src = (const char*) (name()->as_C_string());
3008 const int src_length = (int)strlen(src);
3009
3010 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3011
3012 // Add L as type indicator
3013 int dest_index = 0;
3014 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3015
3016 // Add the actual class name
3017 for (int src_index = 0; src_index < src_length; ) {
3018 dest[dest_index++] = src[src_index++];
3019 }
3020
3021 if (is_hidden()) { // Replace the last '+' with a '.'.
3022 for (int index = (int)src_length; index > 0; index--) {
3023 if (dest[index] == '+') {
3024 dest[index] = JVM_SIGNATURE_DOT;
3025 break;
3026 }
3027 }
3028 }
3029
3030 // Add the semicolon and the null
3031 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3032 dest[dest_index] = '\0';
3033 return dest;
3034 }
3035
3036 ModuleEntry* InstanceKlass::module() const {
3037 if (is_hidden() &&
3038 in_unnamed_package() &&
3039 class_loader_data()->has_class_mirror_holder()) {
3040 // For a non-strong hidden class defined to an unnamed package,
3041 // its (class held) CLD will not have an unnamed module created for it.
3042 // Two choices to find the correct ModuleEntry:
3043 // 1. If hidden class is within a nest, use nest host's module
3044 // 2. Find the unnamed module off from the class loader
3045 // For now option #2 is used since a nest host is not set until
3046 // after the instance class is created in jvm_lookup_define_class().
3047 if (class_loader_data()->is_boot_class_loader_data()) {
3048 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3049 } else {
3050 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3051 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3052 return java_lang_Module::module_entry(module);
3053 }
3054 }
3055
3056 // Class is in a named package
3057 if (!in_unnamed_package()) {
3058 return _package_entry->module();
3059 }
3060
3061 // Class is in an unnamed package, return its loader's unnamed module
3062 return class_loader_data()->unnamed_module();
3063 }
3064
3065 bool InstanceKlass::in_javabase_module() const {
3066 return module()->name() == vmSymbols::java_base();
3067 }
3068
3069 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3070
3071 // ensure java/ packages only loaded by boot or platform builtin loaders
3072 // not needed for shared class since CDS does not archive prohibited classes.
3073 if (!is_shared()) {
3074 check_prohibited_package(name(), loader_data, CHECK);
3075 }
3076
3077 if (is_shared() && _package_entry != nullptr) {
3078 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3079 // we can use the saved package
3080 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3081 return;
3082 } else {
3083 _package_entry = nullptr;
3084 }
3085 }
3086
3087 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3088 // it returns, so we need to decrement it when the current function exits.
3089 TempNewSymbol from_class_name =
3090 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3091
3092 Symbol* pkg_name;
3093 if (pkg_entry != nullptr) {
3094 pkg_name = pkg_entry->name();
3095 } else {
3096 pkg_name = from_class_name;
3097 }
3098
3099 if (pkg_name != nullptr && loader_data != nullptr) {
3100
3101 // Find in class loader's package entry table.
3102 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3103
3104 // If the package name is not found in the loader's package
3105 // entry table, it is an indication that the package has not
3106 // been defined. Consider it defined within the unnamed module.
3107 if (_package_entry == nullptr) {
3108
3109 if (!ModuleEntryTable::javabase_defined()) {
3110 // Before java.base is defined during bootstrapping, define all packages in
3111 // the java.base module. If a non-java.base package is erroneously placed
3112 // in the java.base module it will be caught later when java.base
3113 // is defined by ModuleEntryTable::verify_javabase_packages check.
3114 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3115 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3116 } else {
3117 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3118 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3119 }
3120
3121 // A package should have been successfully created
3122 DEBUG_ONLY(ResourceMark rm(THREAD));
3123 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3124 name()->as_C_string(), loader_data->loader_name_and_id());
3125 }
3126
3127 if (log_is_enabled(Debug, module)) {
3128 ResourceMark rm(THREAD);
3129 ModuleEntry* m = _package_entry->module();
3130 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3131 external_name(),
3132 pkg_name->as_C_string(),
3133 loader_data->loader_name_and_id(),
3134 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3135 }
3136 } else {
3137 ResourceMark rm(THREAD);
3138 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3139 external_name(),
3140 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3141 UNNAMED_MODULE);
3142 }
3143 }
3144
3145 // Function set_classpath_index ensures that for a non-null _package_entry
3146 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3147 // It then sets the classpath_index in the package entry record.
3148 //
3149 // The classpath_index field is used to find the entry on the boot loader class
3150 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3151 // in an unnamed module. It is also used to indicate (for all packages whose
3152 // classes are loaded by the boot loader) that at least one of the package's
3153 // classes has been loaded.
3154 void InstanceKlass::set_classpath_index(s2 path_index) {
3155 if (_package_entry != nullptr) {
3156 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3157 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3158 assert(path_index != -1, "Unexpected classpath_index");
3159 _package_entry->set_classpath_index(path_index);
3160 }
3161 }
3162
3163 // different versions of is_same_class_package
3164
3165 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3166 oop classloader1 = this->class_loader();
3167 PackageEntry* classpkg1 = this->package();
3168 if (class2->is_objArray_klass()) {
3169 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3170 }
3171
3172 oop classloader2;
3173 PackageEntry* classpkg2;
3174 if (class2->is_instance_klass()) {
3175 classloader2 = class2->class_loader();
3176 classpkg2 = class2->package();
3177 } else {
3178 assert(class2->is_typeArray_klass(), "should be type array");
3179 classloader2 = nullptr;
3180 classpkg2 = nullptr;
3181 }
3182
3183 // Same package is determined by comparing class loader
3184 // and package entries. Both must be the same. This rule
3185 // applies even to classes that are defined in the unnamed
3186 // package, they still must have the same class loader.
3187 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3188 return true;
3189 }
3190
3191 return false;
3192 }
3193
3194 // return true if this class and other_class are in the same package. Classloader
3195 // and classname information is enough to determine a class's package
3196 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3197 const Symbol* other_class_name) const {
3198 if (class_loader() != other_class_loader) {
3199 return false;
3200 }
3201 if (name()->fast_compare(other_class_name) == 0) {
3202 return true;
3203 }
3204
3205 {
3206 ResourceMark rm;
3207
3208 bool bad_class_name = false;
3209 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3210 if (bad_class_name) {
3211 return false;
3212 }
3213 // Check that package_from_class_name() returns null, not "", if there is no package.
3214 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3215
3216 const Symbol* const this_package_name =
3217 this->package() != nullptr ? this->package()->name() : nullptr;
3218
3219 if (this_package_name == nullptr || other_pkg == nullptr) {
3220 // One of the two doesn't have a package. Only return true if the other
3221 // one also doesn't have a package.
3222 return this_package_name == other_pkg;
3223 }
3224
3225 // Check if package is identical
3226 return this_package_name->fast_compare(other_pkg) == 0;
3227 }
3228 }
3229
3230 static bool is_prohibited_package_slow(Symbol* class_name) {
3231 // Caller has ResourceMark
3232 int length;
3233 jchar* unicode = class_name->as_unicode(length);
3234 return (length >= 5 &&
3235 unicode[0] == 'j' &&
3236 unicode[1] == 'a' &&
3237 unicode[2] == 'v' &&
3238 unicode[3] == 'a' &&
3239 unicode[4] == '/');
3240 }
3241
3242 // Only boot and platform class loaders can define classes in "java/" packages.
3243 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3244 ClassLoaderData* loader_data,
3245 TRAPS) {
3246 if (!loader_data->is_boot_class_loader_data() &&
3247 !loader_data->is_platform_class_loader_data() &&
3248 class_name != nullptr && class_name->utf8_length() >= 5) {
3249 ResourceMark rm(THREAD);
3250 bool prohibited;
3251 const u1* base = class_name->base();
3252 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3253 prohibited = is_prohibited_package_slow(class_name);
3254 } else {
3255 char* name = class_name->as_C_string();
3256 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3257 }
3258 if (prohibited) {
3259 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3260 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3261 char* name = pkg_name->as_C_string();
3262 const char* class_loader_name = loader_data->loader_name_and_id();
3263 StringUtils::replace_no_expand(name, "/", ".");
3264 const char* msg_text1 = "Class loader (instance of): ";
3265 const char* msg_text2 = " tried to load prohibited package name: ";
3266 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3267 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3268 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3269 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3270 }
3271 }
3272 return;
3273 }
3274
3275 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3276 constantPoolHandle i_cp(THREAD, constants());
3277 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3278 int ioff = iter.inner_class_info_index();
3279 if (ioff != 0) {
3280 // Check to see if the name matches the class we're looking for
3281 // before attempting to find the class.
3282 if (i_cp->klass_name_at_matches(this, ioff)) {
3283 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3284 if (this == inner_klass) {
3285 *ooff = iter.outer_class_info_index();
3286 *noff = iter.inner_name_index();
3287 return true;
3288 }
3289 }
3290 }
3291 }
3292 return false;
3293 }
3294
3295 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3296 InstanceKlass* outer_klass = nullptr;
3297 *inner_is_member = false;
3298 int ooff = 0, noff = 0;
3299 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3300 if (has_inner_classes_attr) {
3301 constantPoolHandle i_cp(THREAD, constants());
3302 if (ooff != 0) {
3303 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3304 if (!ok->is_instance_klass()) {
3305 // If the outer class is not an instance klass then it cannot have
3306 // declared any inner classes.
3307 ResourceMark rm(THREAD);
3308 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3309 Exceptions::fthrow(
3310 THREAD_AND_LOCATION,
3311 vmSymbols::java_lang_IncompatibleClassChangeError(),
3312 "%s and %s disagree on InnerClasses attribute",
3313 ok->external_name(),
3314 external_name());
3315 return nullptr;
3316 }
3317 outer_klass = InstanceKlass::cast(ok);
3318 *inner_is_member = true;
3319 }
3320 if (nullptr == outer_klass) {
3321 // It may be a local class; try for that.
3322 int encl_method_class_idx = enclosing_method_class_index();
3323 if (encl_method_class_idx != 0) {
3324 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3325 outer_klass = InstanceKlass::cast(ok);
3326 *inner_is_member = false;
3327 }
3328 }
3329 }
3330
3331 // If no inner class attribute found for this class.
3332 if (nullptr == outer_klass) return nullptr;
3333
3334 // Throws an exception if outer klass has not declared k as an inner klass
3335 // We need evidence that each klass knows about the other, or else
3336 // the system could allow a spoof of an inner class to gain access rights.
3337 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3338 return outer_klass;
3339 }
3340
3341 u2 InstanceKlass::compute_modifier_flags() const {
3342 u2 access = access_flags().as_unsigned_short();
3343
3344 // But check if it happens to be member class.
3345 InnerClassesIterator iter(this);
3346 for (; !iter.done(); iter.next()) {
3347 int ioff = iter.inner_class_info_index();
3348 // Inner class attribute can be zero, skip it.
3349 // Strange but true: JVM spec. allows null inner class refs.
3350 if (ioff == 0) continue;
3351
3352 // only look at classes that are already loaded
3353 // since we are looking for the flags for our self.
3354 Symbol* inner_name = constants()->klass_name_at(ioff);
3355 if (name() == inner_name) {
3356 // This is really a member class.
3357 access = iter.inner_access_flags();
3358 break;
3359 }
3360 }
3361 // Remember to strip ACC_SUPER bit
3362 return (access & (~JVM_ACC_SUPER));
3363 }
3364
3365 jint InstanceKlass::jvmti_class_status() const {
3366 jint result = 0;
3367
3368 if (is_linked()) {
3369 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3370 }
3371
3372 if (is_initialized()) {
3373 assert(is_linked(), "Class status is not consistent");
3374 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3375 }
3376 if (is_in_error_state()) {
3377 result |= JVMTI_CLASS_STATUS_ERROR;
3378 }
3379 return result;
3380 }
3381
3382 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3383 bool implements_interface; // initialized by method_at_itable_or_null
3384 Method* m = method_at_itable_or_null(holder, index,
3385 implements_interface); // out parameter
3386 if (m != nullptr) {
3387 assert(implements_interface, "sanity");
3388 return m;
3389 } else if (implements_interface) {
3390 // Throw AbstractMethodError since corresponding itable slot is empty.
3391 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3392 } else {
3393 // If the interface isn't implemented by the receiver class,
3394 // the VM should throw IncompatibleClassChangeError.
3395 ResourceMark rm(THREAD);
3396 stringStream ss;
3397 bool same_module = (module() == holder->module());
3398 ss.print("Receiver class %s does not implement "
3399 "the interface %s defining the method to be called "
3400 "(%s%s%s)",
3401 external_name(), holder->external_name(),
3402 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3403 (same_module) ? "" : "; ",
3404 (same_module) ? "" : holder->class_in_module_of_loader());
3405 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3406 }
3407 }
3408
3409 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3410 klassItable itable(this);
3411 for (int i = 0; i < itable.size_offset_table(); i++) {
3412 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3413 if (offset_entry->interface_klass() == holder) {
3414 implements_interface = true;
3415 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3416 Method* m = ime[index].method();
3417 return m;
3418 }
3419 }
3420 implements_interface = false;
3421 return nullptr; // offset entry not found
3422 }
3423
3424 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3425 assert(is_linked(), "required");
3426 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3427 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3428
3429 int vtable_index = Method::invalid_vtable_index;
3430 Symbol* name = intf_method->name();
3431 Symbol* signature = intf_method->signature();
3432
3433 // First check in default method array
3434 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3435 int index = find_method_index(default_methods(),
3436 name, signature,
3437 Klass::OverpassLookupMode::find,
3438 Klass::StaticLookupMode::find,
3439 Klass::PrivateLookupMode::find);
3440 if (index >= 0) {
3441 vtable_index = default_vtable_indices()->at(index);
3442 }
3443 }
3444 if (vtable_index == Method::invalid_vtable_index) {
3445 // get vtable_index for miranda methods
3446 klassVtable vt = vtable();
3447 vtable_index = vt.index_of_miranda(name, signature);
3448 }
3449 return vtable_index;
3450 }
3451
3452 #if INCLUDE_JVMTI
3453 // update default_methods for redefineclasses for methods that are
3454 // not yet in the vtable due to concurrent subclass define and superinterface
3455 // redefinition
3456 // Note: those in the vtable, should have been updated via adjust_method_entries
3457 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3458 // search the default_methods for uses of either obsolete or EMCP methods
3459 if (default_methods() != nullptr) {
3460 for (int index = 0; index < default_methods()->length(); index ++) {
3461 Method* old_method = default_methods()->at(index);
3462 if (old_method == nullptr || !old_method->is_old()) {
3463 continue; // skip uninteresting entries
3464 }
3465 assert(!old_method->is_deleted(), "default methods may not be deleted");
3466 Method* new_method = old_method->get_new_method();
3467 default_methods()->at_put(index, new_method);
3468
3469 if (log_is_enabled(Info, redefine, class, update)) {
3470 ResourceMark rm;
3471 if (!(*trace_name_printed)) {
3472 log_info(redefine, class, update)
3473 ("adjust: klassname=%s default methods from name=%s",
3474 external_name(), old_method->method_holder()->external_name());
3475 *trace_name_printed = true;
3476 }
3477 log_debug(redefine, class, update, vtables)
3478 ("default method update: %s(%s) ",
3479 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3480 }
3481 }
3482 }
3483 }
3484 #endif // INCLUDE_JVMTI
3485
3486 // On-stack replacement stuff
3487 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3488 assert_lock_strong(NMethodState_lock);
3489 #ifndef PRODUCT
3490 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3491 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3492 "redundant OSR recompilation detected. memory leak in CodeCache!");
3493 #endif
3494 // only one compilation can be active
3495 assert(n->is_osr_method(), "wrong kind of nmethod");
3496 n->set_osr_link(osr_nmethods_head());
3497 set_osr_nmethods_head(n);
3498 // Raise the highest osr level if necessary
3499 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3500
3501 // Get rid of the osr methods for the same bci that have lower levels.
3502 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3503 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3504 if (inv != nullptr && inv->is_in_use()) {
3505 inv->make_not_entrant();
3506 }
3507 }
3508 }
3509
3510 // Remove osr nmethod from the list. Return true if found and removed.
3511 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3512 // This is a short non-blocking critical region, so the no safepoint check is ok.
3513 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3514 assert(n->is_osr_method(), "wrong kind of nmethod");
3515 nmethod* last = nullptr;
3516 nmethod* cur = osr_nmethods_head();
3517 int max_level = CompLevel_none; // Find the max comp level excluding n
3518 Method* m = n->method();
3519 // Search for match
3520 bool found = false;
3521 while(cur != nullptr && cur != n) {
3522 if (m == cur->method()) {
3523 // Find max level before n
3524 max_level = MAX2(max_level, cur->comp_level());
3525 }
3526 last = cur;
3527 cur = cur->osr_link();
3528 }
3529 nmethod* next = nullptr;
3530 if (cur == n) {
3531 found = true;
3532 next = cur->osr_link();
3533 if (last == nullptr) {
3534 // Remove first element
3535 set_osr_nmethods_head(next);
3536 } else {
3537 last->set_osr_link(next);
3538 }
3539 }
3540 n->set_osr_link(nullptr);
3541 cur = next;
3542 while (cur != nullptr) {
3543 // Find max level after n
3544 if (m == cur->method()) {
3545 max_level = MAX2(max_level, cur->comp_level());
3546 }
3547 cur = cur->osr_link();
3548 }
3549 m->set_highest_osr_comp_level(max_level);
3550 return found;
3551 }
3552
3553 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3554 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3555 nmethod* osr = osr_nmethods_head();
3556 int found = 0;
3557 while (osr != nullptr) {
3558 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3559 if (osr->method() == m) {
3560 deopt_scope->mark(osr);
3561 found++;
3562 }
3563 osr = osr->osr_link();
3564 }
3565 return found;
3566 }
3567
3568 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3569 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3570 nmethod* osr = osr_nmethods_head();
3571 nmethod* best = nullptr;
3572 while (osr != nullptr) {
3573 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3574 // There can be a time when a c1 osr method exists but we are waiting
3575 // for a c2 version. When c2 completes its osr nmethod we will trash
3576 // the c1 version and only be able to find the c2 version. However
3577 // while we overflow in the c1 code at back branches we don't want to
3578 // try and switch to the same code as we are already running
3579
3580 if (osr->method() == m &&
3581 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3582 if (match_level) {
3583 if (osr->comp_level() == comp_level) {
3584 // Found a match - return it.
3585 return osr;
3586 }
3587 } else {
3588 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3589 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3590 // Found the best possible - return it.
3591 return osr;
3592 }
3593 best = osr;
3594 }
3595 }
3596 }
3597 osr = osr->osr_link();
3598 }
3599
3600 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3601 if (best != nullptr && best->comp_level() >= comp_level) {
3602 return best;
3603 }
3604 return nullptr;
3605 }
3606
3607 // -----------------------------------------------------------------------------------------------------
3608 // Printing
3609
3610 #define BULLET " - "
3611
3612 static const char* state_names[] = {
3613 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3614 };
3615
3616 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3617 for (int i = 0; i < len; i++) {
3618 intptr_t e = start[i];
3619 st->print("%d : " INTPTR_FORMAT, i, e);
3620 if (MetaspaceObj::is_valid((Metadata*)e)) {
3621 st->print(" ");
3622 ((Metadata*)e)->print_value_on(st);
3623 }
3624 st->cr();
3625 }
3626 }
3627
3628 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3629 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3630 }
3631
3632 const char* InstanceKlass::init_state_name() const {
3633 return state_names[init_state()];
3634 }
3635
3636 void InstanceKlass::print_on(outputStream* st) const {
3637 assert(is_klass(), "must be klass");
3638 Klass::print_on(st);
3639
3640 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3641 st->print(BULLET"klass size: %d", size()); st->cr();
3642 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3643 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3644 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3645 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3646 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3647 st->print(BULLET"sub: ");
3648 Klass* sub = subklass();
3649 int n;
3650 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3651 if (n < MaxSubklassPrintSize) {
3652 sub->print_value_on(st);
3653 st->print(" ");
3654 }
3655 }
3656 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3657 st->cr();
3658
3659 if (is_interface()) {
3660 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3661 if (nof_implementors() == 1) {
3662 st->print_cr(BULLET"implementor: ");
3663 st->print(" ");
3664 implementor()->print_value_on(st);
3665 st->cr();
3666 }
3667 }
3668
3669 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3670 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3671 if (Verbose || WizardMode) {
3672 Array<Method*>* method_array = methods();
3673 for (int i = 0; i < method_array->length(); i++) {
3674 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3675 }
3676 }
3677 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3678 if (default_methods() != nullptr) {
3679 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3680 if (Verbose) {
3681 Array<Method*>* method_array = default_methods();
3682 for (int i = 0; i < method_array->length(); i++) {
3683 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3684 }
3685 }
3686 }
3687 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3688 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3689 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3690
3691 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3692
3693 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3694 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3695
3696 if (secondary_supers() != nullptr) {
3697 if (Verbose) {
3698 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3699 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3700 for (int i = 0; i < _secondary_supers->length(); i++) {
3701 ResourceMark rm; // for external_name()
3702 Klass* secondary_super = _secondary_supers->at(i);
3703 st->print(BULLET"%2d:", i);
3704 if (is_hashed) {
3705 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3706 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3707 st->print(" dist:%02d:", distance);
3708 }
3709 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3710 }
3711 }
3712 }
3713 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3714
3715 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3716 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3717 if (source_debug_extension() != nullptr) {
3718 st->print(BULLET"source debug extension: ");
3719 st->print("%s", source_debug_extension());
3720 st->cr();
3721 }
3722 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3723 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3724 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3725 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3726 {
3727 bool have_pv = false;
3728 // previous versions are linked together through the InstanceKlass
3729 for (InstanceKlass* pv_node = previous_versions();
3730 pv_node != nullptr;
3731 pv_node = pv_node->previous_versions()) {
3732 if (!have_pv)
3733 st->print(BULLET"previous version: ");
3734 have_pv = true;
3735 pv_node->constants()->print_value_on(st);
3736 }
3737 if (have_pv) st->cr();
3738 }
3739
3740 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3741 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3742 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3743 print_on_maybe_null(st, BULLET"record components: ", record_components());
3744 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3745 if (java_mirror() != nullptr) {
3746 st->print(BULLET"java mirror: ");
3747 java_mirror()->print_value_on(st);
3748 st->cr();
3749 } else {
3750 st->print_cr(BULLET"java mirror: null");
3751 }
3752 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3753 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3754 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3755 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3756 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3757
3758 FieldPrinter print_static_field(st);
3759 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3760 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3761 FieldPrinter print_nonstatic_field(st);
3762 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3763 ik->print_nonstatic_fields(&print_nonstatic_field);
3764
3765 st->print(BULLET"non-static oop maps: ");
3766 OopMapBlock* map = start_of_nonstatic_oop_maps();
3767 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3768 while (map < end_map) {
3769 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3770 map++;
3771 }
3772 st->cr();
3773 }
3774
3775 void InstanceKlass::print_value_on(outputStream* st) const {
3776 assert(is_klass(), "must be klass");
3777 if (Verbose || WizardMode) access_flags().print_on(st);
3778 name()->print_value_on(st);
3779 }
3780
3781 void FieldPrinter::do_field(fieldDescriptor* fd) {
3782 _st->print(BULLET);
3783 if (_obj == nullptr) {
3784 fd->print_on(_st);
3785 _st->cr();
3786 } else {
3787 fd->print_on_for(_st, _obj);
3788 _st->cr();
3789 }
3790 }
3791
3792
3793 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3794 Klass::oop_print_on(obj, st);
3795
3796 if (this == vmClasses::String_klass()) {
3797 typeArrayOop value = java_lang_String::value(obj);
3798 juint length = java_lang_String::length(obj);
3799 if (value != nullptr &&
3800 value->is_typeArray() &&
3801 length <= (juint) value->length()) {
3802 st->print(BULLET"string: ");
3803 java_lang_String::print(obj, st);
3804 st->cr();
3805 }
3806 }
3807
3808 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3809 FieldPrinter print_field(st, obj);
3810 print_nonstatic_fields(&print_field);
3811
3812 if (this == vmClasses::Class_klass()) {
3813 st->print(BULLET"signature: ");
3814 java_lang_Class::print_signature(obj, st);
3815 st->cr();
3816 Klass* real_klass = java_lang_Class::as_Klass(obj);
3817 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3818 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3819 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3820 }
3821 } else if (this == vmClasses::MethodType_klass()) {
3822 st->print(BULLET"signature: ");
3823 java_lang_invoke_MethodType::print_signature(obj, st);
3824 st->cr();
3825 }
3826 }
3827
3828 #ifndef PRODUCT
3829
3830 bool InstanceKlass::verify_itable_index(int i) {
3831 int method_count = klassItable::method_count_for_interface(this);
3832 assert(i >= 0 && i < method_count, "index out of bounds");
3833 return true;
3834 }
3835
3836 #endif //PRODUCT
3837
3838 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3839 st->print("a ");
3840 name()->print_value_on(st);
3841 obj->print_address_on(st);
3842 if (this == vmClasses::String_klass()
3843 && java_lang_String::value(obj) != nullptr) {
3844 ResourceMark rm;
3845 int len = java_lang_String::length(obj);
3846 int plen = (len < 24 ? len : 12);
3847 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3848 st->print(" = \"%s\"", str);
3849 if (len > plen)
3850 st->print("...[%d]", len);
3851 } else if (this == vmClasses::Class_klass()) {
3852 Klass* k = java_lang_Class::as_Klass(obj);
3853 st->print(" = ");
3854 if (k != nullptr) {
3855 k->print_value_on(st);
3856 } else {
3857 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3858 st->print("%s", tname ? tname : "type?");
3859 }
3860 } else if (this == vmClasses::MethodType_klass()) {
3861 st->print(" = ");
3862 java_lang_invoke_MethodType::print_signature(obj, st);
3863 } else if (java_lang_boxing_object::is_instance(obj)) {
3864 st->print(" = ");
3865 java_lang_boxing_object::print(obj, st);
3866 } else if (this == vmClasses::LambdaForm_klass()) {
3867 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3868 if (vmentry != nullptr) {
3869 st->print(" => ");
3870 vmentry->print_value_on(st);
3871 }
3872 } else if (this == vmClasses::MemberName_klass()) {
3873 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3874 if (vmtarget != nullptr) {
3875 st->print(" = ");
3876 vmtarget->print_value_on(st);
3877 } else {
3878 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3879 oop name = java_lang_invoke_MemberName::name(obj);
3880 if (clazz != nullptr) {
3881 clazz->print_value_on(st);
3882 } else {
3883 st->print("null");
3884 }
3885 st->print(".");
3886 if (name != nullptr) {
3887 name->print_value_on(st);
3888 } else {
3889 st->print("null");
3890 }
3891 }
3892 }
3893 }
3894
3895 const char* InstanceKlass::internal_name() const {
3896 return external_name();
3897 }
3898
3899 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3900 const ModuleEntry* module_entry,
3901 const ClassFileStream* cfs) const {
3902
3903 if (ClassListWriter::is_enabled()) {
3904 ClassListWriter::write(this, cfs);
3905 }
3906
3907 print_class_load_helper(loader_data, module_entry, cfs);
3908 print_class_load_cause_logging();
3909 }
3910
3911 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3912 const ModuleEntry* module_entry,
3913 const ClassFileStream* cfs) const {
3914
3915 if (!log_is_enabled(Info, class, load)) {
3916 return;
3917 }
3918
3919 ResourceMark rm;
3920 LogMessage(class, load) msg;
3921 stringStream info_stream;
3922
3923 // Name and class hierarchy info
3924 info_stream.print("%s", external_name());
3925
3926 // Source
3927 if (cfs != nullptr) {
3928 if (cfs->source() != nullptr) {
3929 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3930 if (module_name != nullptr) {
3931 // When the boot loader created the stream, it didn't know the module name
3932 // yet. Let's format it now.
3933 if (cfs->from_boot_loader_modules_image()) {
3934 info_stream.print(" source: jrt:/%s", module_name);
3935 } else {
3936 info_stream.print(" source: %s", cfs->source());
3937 }
3938 } else {
3939 info_stream.print(" source: %s", cfs->source());
3940 }
3941 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3942 Thread* current = Thread::current();
3943 Klass* caller = current->is_Java_thread() ?
3944 JavaThread::cast(current)->security_get_caller_class(1):
3945 nullptr;
3946 // caller can be null, for example, during a JVMTI VM_Init hook
3947 if (caller != nullptr) {
3948 info_stream.print(" source: instance of %s", caller->external_name());
3949 } else {
3950 // source is unknown
3951 }
3952 } else {
3953 oop class_loader = loader_data->class_loader();
3954 info_stream.print(" source: %s", class_loader->klass()->external_name());
3955 }
3956 } else {
3957 assert(this->is_shared(), "must be");
3958 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3959 info_stream.print(" source: shared objects file (top)");
3960 } else {
3961 info_stream.print(" source: shared objects file");
3962 }
3963 }
3964
3965 msg.info("%s", info_stream.as_string());
3966
3967 if (log_is_enabled(Debug, class, load)) {
3968 stringStream debug_stream;
3969
3970 // Class hierarchy info
3971 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3972 p2i(this), p2i(superklass()));
3973
3974 // Interfaces
3975 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3976 debug_stream.print(" interfaces:");
3977 int length = local_interfaces()->length();
3978 for (int i = 0; i < length; i++) {
3979 debug_stream.print(" " PTR_FORMAT,
3980 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3981 }
3982 }
3983
3984 // Class loader
3985 debug_stream.print(" loader: [");
3986 loader_data->print_value_on(&debug_stream);
3987 debug_stream.print("]");
3988
3989 // Classfile checksum
3990 if (cfs) {
3991 debug_stream.print(" bytes: %d checksum: %08x",
3992 cfs->length(),
3993 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3994 cfs->length()));
3995 }
3996
3997 msg.debug("%s", debug_stream.as_string());
3998 }
3999 }
4000
4001 void InstanceKlass::print_class_load_cause_logging() const {
4002 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4003 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4004 JavaThread* current = JavaThread::current();
4005 ResourceMark rm(current);
4006 const char* name = external_name();
4007
4008 if (LogClassLoadingCauseFor == nullptr ||
4009 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4010 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4011 return;
4012 }
4013
4014 // Log Java stack first
4015 {
4016 LogMessage(class, load, cause) msg;
4017 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4018
4019 info_stream.print_cr("Java stack when loading %s:", name);
4020 current->print_stack_on(&info_stream);
4021 }
4022
4023 // Log native stack second
4024 if (log_cause_native) {
4025 // Log to string first so that lines can be indented
4026 stringStream stack_stream;
4027 char buf[O_BUFLEN];
4028 address lastpc = nullptr;
4029 NativeStackPrinter nsp(current);
4030 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4031 true /* print_source_info */, -1 /* max stack */);
4032
4033 LogMessage(class, load, cause, native) msg;
4034 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4035 info_stream.print_cr("Native stack when loading %s:", name);
4036
4037 // Print each native stack line to the log
4038 int size = (int) stack_stream.size();
4039 char* stack = stack_stream.as_string();
4040 char* stack_end = stack + size;
4041 char* line_start = stack;
4042 for (char* p = stack; p < stack_end; p++) {
4043 if (*p == '\n') {
4044 *p = '\0';
4045 info_stream.print_cr("\t%s", line_start);
4046 line_start = p + 1;
4047 }
4048 }
4049 if (line_start < stack_end) {
4050 info_stream.print_cr("\t%s", line_start);
4051 }
4052 }
4053 }
4054 }
4055
4056 // Verification
4057
4058 class VerifyFieldClosure: public BasicOopIterateClosure {
4059 protected:
4060 template <class T> void do_oop_work(T* p) {
4061 oop obj = RawAccess<>::oop_load(p);
4062 if (!oopDesc::is_oop_or_null(obj)) {
4063 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4064 Universe::print_on(tty);
4065 guarantee(false, "boom");
4066 }
4067 }
4068 public:
4069 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4070 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4071 };
4072
4073 void InstanceKlass::verify_on(outputStream* st) {
4074 #ifndef PRODUCT
4075 // Avoid redundant verifies, this really should be in product.
4076 if (_verify_count == Universe::verify_count()) return;
4077 _verify_count = Universe::verify_count();
4078 #endif
4079
4080 // Verify Klass
4081 Klass::verify_on(st);
4082
4083 // Verify that klass is present in ClassLoaderData
4084 guarantee(class_loader_data()->contains_klass(this),
4085 "this class isn't found in class loader data");
4086
4087 // Verify vtables
4088 if (is_linked()) {
4089 // $$$ This used to be done only for m/s collections. Doing it
4090 // always seemed a valid generalization. (DLD -- 6/00)
4091 vtable().verify(st);
4092 }
4093
4094 // Verify first subklass
4095 if (subklass() != nullptr) {
4096 guarantee(subklass()->is_klass(), "should be klass");
4097 }
4098
4099 // Verify siblings
4100 Klass* super = this->super();
4101 Klass* sib = next_sibling();
4102 if (sib != nullptr) {
4103 if (sib == this) {
4104 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4105 }
4106
4107 guarantee(sib->is_klass(), "should be klass");
4108 guarantee(sib->super() == super, "siblings should have same superklass");
4109 }
4110
4111 // Verify local interfaces
4112 if (local_interfaces()) {
4113 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4114 for (int j = 0; j < local_interfaces->length(); j++) {
4115 InstanceKlass* e = local_interfaces->at(j);
4116 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4117 }
4118 }
4119
4120 // Verify transitive interfaces
4121 if (transitive_interfaces() != nullptr) {
4122 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4123 for (int j = 0; j < transitive_interfaces->length(); j++) {
4124 InstanceKlass* e = transitive_interfaces->at(j);
4125 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4126 }
4127 }
4128
4129 // Verify methods
4130 if (methods() != nullptr) {
4131 Array<Method*>* methods = this->methods();
4132 for (int j = 0; j < methods->length(); j++) {
4133 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4134 }
4135 for (int j = 0; j < methods->length() - 1; j++) {
4136 Method* m1 = methods->at(j);
4137 Method* m2 = methods->at(j + 1);
4138 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4139 }
4140 }
4141
4142 // Verify method ordering
4143 if (method_ordering() != nullptr) {
4144 Array<int>* method_ordering = this->method_ordering();
4145 int length = method_ordering->length();
4146 if (JvmtiExport::can_maintain_original_method_order() ||
4147 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4148 guarantee(length == methods()->length(), "invalid method ordering length");
4149 jlong sum = 0;
4150 for (int j = 0; j < length; j++) {
4151 int original_index = method_ordering->at(j);
4152 guarantee(original_index >= 0, "invalid method ordering index");
4153 guarantee(original_index < length, "invalid method ordering index");
4154 sum += original_index;
4155 }
4156 // Verify sum of indices 0,1,...,length-1
4157 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4158 } else {
4159 guarantee(length == 0, "invalid method ordering length");
4160 }
4161 }
4162
4163 // Verify default methods
4164 if (default_methods() != nullptr) {
4165 Array<Method*>* methods = this->default_methods();
4166 for (int j = 0; j < methods->length(); j++) {
4167 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4168 }
4169 for (int j = 0; j < methods->length() - 1; j++) {
4170 Method* m1 = methods->at(j);
4171 Method* m2 = methods->at(j + 1);
4172 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4173 }
4174 }
4175
4176 // Verify JNI static field identifiers
4177 if (jni_ids() != nullptr) {
4178 jni_ids()->verify(this);
4179 }
4180
4181 // Verify other fields
4182 if (constants() != nullptr) {
4183 guarantee(constants()->is_constantPool(), "should be constant pool");
4184 }
4185 }
4186
4187 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4188 Klass::oop_verify_on(obj, st);
4189 VerifyFieldClosure blk;
4190 obj->oop_iterate(&blk);
4191 }
4192
4193
4194 // JNIid class for jfieldIDs only
4195 // Note to reviewers:
4196 // These JNI functions are just moved over to column 1 and not changed
4197 // in the compressed oops workspace.
4198 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4199 _holder = holder;
4200 _offset = offset;
4201 _next = next;
4202 debug_only(_is_static_field_id = false;)
4203 }
4204
4205
4206 JNIid* JNIid::find(int offset) {
4207 JNIid* current = this;
4208 while (current != nullptr) {
4209 if (current->offset() == offset) return current;
4210 current = current->next();
4211 }
4212 return nullptr;
4213 }
4214
4215 void JNIid::deallocate(JNIid* current) {
4216 while (current != nullptr) {
4217 JNIid* next = current->next();
4218 delete current;
4219 current = next;
4220 }
4221 }
4222
4223
4224 void JNIid::verify(Klass* holder) {
4225 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4226 int end_field_offset;
4227 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4228
4229 JNIid* current = this;
4230 while (current != nullptr) {
4231 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4232 #ifdef ASSERT
4233 int o = current->offset();
4234 if (current->is_static_field_id()) {
4235 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4236 }
4237 #endif
4238 current = current->next();
4239 }
4240 }
4241
4242 void InstanceKlass::set_init_state(ClassState state) {
4243 #ifdef ASSERT
4244 bool good_state = is_shared() ? (_init_state <= state)
4245 : (_init_state < state);
4246 assert(good_state || state == allocated, "illegal state transition");
4247 #endif
4248 assert(_init_thread == nullptr, "should be cleared before state change");
4249 Atomic::release_store(&_init_state, state);
4250 }
4251
4252 #if INCLUDE_JVMTI
4253
4254 // RedefineClasses() support for previous versions
4255
4256 // Globally, there is at least one previous version of a class to walk
4257 // during class unloading, which is saved because old methods in the class
4258 // are still running. Otherwise the previous version list is cleaned up.
4259 bool InstanceKlass::_should_clean_previous_versions = false;
4260
4261 // Returns true if there are previous versions of a class for class
4262 // unloading only. Also resets the flag to false. purge_previous_version
4263 // will set the flag to true if there are any left, i.e., if there's any
4264 // work to do for next time. This is to avoid the expensive code cache
4265 // walk in CLDG::clean_deallocate_lists().
4266 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4267 bool ret = _should_clean_previous_versions;
4268 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4269 ret ? "true" : "false");
4270 _should_clean_previous_versions = false;
4271 return ret;
4272 }
4273
4274 // This nulls out jmethodIDs for all methods in 'klass'
4275 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4276 // during class unloading.
4277 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4278 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4279 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4280 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4281 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4282 Array<Method*>* method_refs = klass->methods();
4283 for (int k = 0; k < method_refs->length(); k++) {
4284 Method* method = method_refs->at(k);
4285 if (method != nullptr && method->is_obsolete()) {
4286 method->clear_jmethod_id();
4287 }
4288 }
4289 }
4290
4291 // Purge previous versions before adding new previous versions of the class and
4292 // during class unloading.
4293 void InstanceKlass::purge_previous_version_list() {
4294 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4295 assert(has_been_redefined(), "Should only be called for main class");
4296
4297 // Quick exit.
4298 if (previous_versions() == nullptr) {
4299 return;
4300 }
4301
4302 // This klass has previous versions so see what we can cleanup
4303 // while it is safe to do so.
4304
4305 int deleted_count = 0; // leave debugging breadcrumbs
4306 int live_count = 0;
4307 ClassLoaderData* loader_data = class_loader_data();
4308 assert(loader_data != nullptr, "should never be null");
4309
4310 ResourceMark rm;
4311 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4312
4313 // previous versions are linked together through the InstanceKlass
4314 InstanceKlass* pv_node = previous_versions();
4315 InstanceKlass* last = this;
4316 int version = 0;
4317
4318 // check the previous versions list
4319 for (; pv_node != nullptr; ) {
4320
4321 ConstantPool* pvcp = pv_node->constants();
4322 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4323
4324 if (!pvcp->on_stack()) {
4325 // If the constant pool isn't on stack, none of the methods
4326 // are executing. Unlink this previous_version.
4327 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4328 // so will be deallocated during the next phase of class unloading.
4329 log_trace(redefine, class, iklass, purge)
4330 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4331 // Unlink from previous version list.
4332 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4333 InstanceKlass* next = pv_node->previous_versions();
4334 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4335 pv_node->link_previous_versions(nullptr); // point next to null
4336 last->link_previous_versions(next);
4337 // Delete this node directly. Nothing is referring to it and we don't
4338 // want it to increase the counter for metadata to delete in CLDG.
4339 MetadataFactory::free_metadata(loader_data, pv_node);
4340 pv_node = next;
4341 deleted_count++;
4342 version++;
4343 continue;
4344 } else {
4345 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4346 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4347 live_count++;
4348 if (pvcp->is_shared()) {
4349 // Shared previous versions can never be removed so no cleaning is needed.
4350 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4351 } else {
4352 // Previous version alive, set that clean is needed for next time.
4353 _should_clean_previous_versions = true;
4354 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4355 }
4356 }
4357
4358 // next previous version
4359 last = pv_node;
4360 pv_node = pv_node->previous_versions();
4361 version++;
4362 }
4363 log_trace(redefine, class, iklass, purge)
4364 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4365 }
4366
4367 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4368 int emcp_method_count) {
4369 int obsolete_method_count = old_methods->length() - emcp_method_count;
4370
4371 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4372 _previous_versions != nullptr) {
4373 // We have a mix of obsolete and EMCP methods so we have to
4374 // clear out any matching EMCP method entries the hard way.
4375 int local_count = 0;
4376 for (int i = 0; i < old_methods->length(); i++) {
4377 Method* old_method = old_methods->at(i);
4378 if (old_method->is_obsolete()) {
4379 // only obsolete methods are interesting
4380 Symbol* m_name = old_method->name();
4381 Symbol* m_signature = old_method->signature();
4382
4383 // previous versions are linked together through the InstanceKlass
4384 int j = 0;
4385 for (InstanceKlass* prev_version = _previous_versions;
4386 prev_version != nullptr;
4387 prev_version = prev_version->previous_versions(), j++) {
4388
4389 Array<Method*>* method_refs = prev_version->methods();
4390 for (int k = 0; k < method_refs->length(); k++) {
4391 Method* method = method_refs->at(k);
4392
4393 if (!method->is_obsolete() &&
4394 method->name() == m_name &&
4395 method->signature() == m_signature) {
4396 // The current RedefineClasses() call has made all EMCP
4397 // versions of this method obsolete so mark it as obsolete
4398 log_trace(redefine, class, iklass, add)
4399 ("%s(%s): flush obsolete method @%d in version @%d",
4400 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4401
4402 method->set_is_obsolete();
4403 break;
4404 }
4405 }
4406
4407 // The previous loop may not find a matching EMCP method, but
4408 // that doesn't mean that we can optimize and not go any
4409 // further back in the PreviousVersion generations. The EMCP
4410 // method for this generation could have already been made obsolete,
4411 // but there still may be an older EMCP method that has not
4412 // been made obsolete.
4413 }
4414
4415 if (++local_count >= obsolete_method_count) {
4416 // no more obsolete methods so bail out now
4417 break;
4418 }
4419 }
4420 }
4421 }
4422 }
4423
4424 // Save the scratch_class as the previous version if any of the methods are running.
4425 // The previous_versions are used to set breakpoints in EMCP methods and they are
4426 // also used to clean MethodData links to redefined methods that are no longer running.
4427 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4428 int emcp_method_count) {
4429 assert(Thread::current()->is_VM_thread(),
4430 "only VMThread can add previous versions");
4431
4432 ResourceMark rm;
4433 log_trace(redefine, class, iklass, add)
4434 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4435
4436 // Clean out old previous versions for this class
4437 purge_previous_version_list();
4438
4439 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4440 // a previous redefinition may be made obsolete by this redefinition.
4441 Array<Method*>* old_methods = scratch_class->methods();
4442 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4443
4444 // If the constant pool for this previous version of the class
4445 // is not marked as being on the stack, then none of the methods
4446 // in this previous version of the class are on the stack so
4447 // we don't need to add this as a previous version.
4448 ConstantPool* cp_ref = scratch_class->constants();
4449 if (!cp_ref->on_stack()) {
4450 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4451 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4452 return;
4453 }
4454
4455 // Add previous version if any methods are still running or if this is
4456 // a shared class which should never be removed.
4457 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4458 scratch_class->link_previous_versions(previous_versions());
4459 link_previous_versions(scratch_class);
4460 if (cp_ref->is_shared()) {
4461 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4462 } else {
4463 // We only set clean_previous_versions flag for processing during class
4464 // unloading for non-shared classes.
4465 _should_clean_previous_versions = true;
4466 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4467 }
4468 } // end add_previous_version()
4469
4470 #endif // INCLUDE_JVMTI
4471
4472 Method* InstanceKlass::method_with_idnum(int idnum) {
4473 Method* m = nullptr;
4474 if (idnum < methods()->length()) {
4475 m = methods()->at(idnum);
4476 }
4477 if (m == nullptr || m->method_idnum() != idnum) {
4478 for (int index = 0; index < methods()->length(); ++index) {
4479 m = methods()->at(index);
4480 if (m->method_idnum() == idnum) {
4481 return m;
4482 }
4483 }
4484 // None found, return null for the caller to handle.
4485 return nullptr;
4486 }
4487 return m;
4488 }
4489
4490
4491 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4492 if (idnum >= methods()->length()) {
4493 return nullptr;
4494 }
4495 Method* m = methods()->at(idnum);
4496 if (m != nullptr && m->orig_method_idnum() == idnum) {
4497 return m;
4498 }
4499 // Obsolete method idnum does not match the original idnum
4500 for (int index = 0; index < methods()->length(); ++index) {
4501 m = methods()->at(index);
4502 if (m->orig_method_idnum() == idnum) {
4503 return m;
4504 }
4505 }
4506 // None found, return null for the caller to handle.
4507 return nullptr;
4508 }
4509
4510
4511 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4512 InstanceKlass* holder = get_klass_version(version);
4513 if (holder == nullptr) {
4514 return nullptr; // The version of klass is gone, no method is found
4515 }
4516 Method* method = holder->method_with_orig_idnum(idnum);
4517 return method;
4518 }
4519
4520 #if INCLUDE_JVMTI
4521 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4522 return _cached_class_file;
4523 }
4524
4525 jint InstanceKlass::get_cached_class_file_len() {
4526 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4527 }
4528
4529 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4530 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4531 }
4532 #endif
4533
4534 // Make a step iterating over the class hierarchy under the root class.
4535 // Skips subclasses if requested.
4536 void ClassHierarchyIterator::next() {
4537 assert(_current != nullptr, "required");
4538 if (_visit_subclasses && _current->subklass() != nullptr) {
4539 _current = _current->subklass();
4540 return; // visit next subclass
4541 }
4542 _visit_subclasses = true; // reset
4543 while (_current->next_sibling() == nullptr && _current != _root) {
4544 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4545 }
4546 if (_current == _root) {
4547 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4548 _current = nullptr;
4549 return;
4550 }
4551 _current = _current->next_sibling();
4552 return; // visit next sibling subclass
4553 }