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/aotMetaspace.hpp"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/cdsEnumKlass.hpp"
30 #include "cds/classListWriter.hpp"
31 #include "cds/heapShared.hpp"
32 #include "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 "klass.inline.hpp"
54 #include "logging/log.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/constantPool.hpp"
65 #include "oops/fieldStreams.inline.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/atomicAccess.hpp"
82 #include "runtime/deoptimization.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/stringUtils.hpp"
101 #ifdef COMPILER1
102 #include "c1/c1_Compiler.hpp"
103 #endif
104 #if INCLUDE_JFR
105 #include "jfr/jfrEvents.hpp"
106 #endif
107
108 #ifdef DTRACE_ENABLED
109
110
111 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
112 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
113 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
114 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
115 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
116 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
117 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
118 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
119 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
120 { \
121 char* data = nullptr; \
122 int len = 0; \
123 Symbol* clss_name = name(); \
124 if (clss_name != nullptr) { \
125 data = (char*)clss_name->bytes(); \
126 len = clss_name->utf8_length(); \
127 } \
128 HOTSPOT_CLASS_INITIALIZATION_##type( \
129 data, len, (void*)class_loader(), thread_type); \
130 }
131
132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
133 { \
134 char* data = nullptr; \
135 int len = 0; \
136 Symbol* clss_name = name(); \
137 if (clss_name != nullptr) { \
138 data = (char*)clss_name->bytes(); \
139 len = clss_name->utf8_length(); \
140 } \
141 HOTSPOT_CLASS_INITIALIZATION_##type( \
142 data, len, (void*)class_loader(), thread_type, wait); \
143 }
144
145 #else // ndef DTRACE_ENABLED
146
147 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
148 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
149
150 #endif // ndef DTRACE_ENABLED
151
152 bool InstanceKlass::_finalization_enabled = true;
153
154 static inline bool is_class_loader(const Symbol* class_name,
155 const ClassFileParser& parser) {
156 assert(class_name != nullptr, "invariant");
157
158 if (class_name == vmSymbols::java_lang_ClassLoader()) {
159 return true;
160 }
161
162 if (vmClasses::ClassLoader_klass_loaded()) {
163 const Klass* const super_klass = parser.super_klass();
164 if (super_klass != nullptr) {
165 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
166 return true;
167 }
168 }
169 }
170 return false;
171 }
172
173 static inline bool is_stack_chunk_class(const Symbol* class_name,
174 const ClassLoaderData* loader_data) {
175 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
176 loader_data->is_the_null_class_loader_data());
177 }
178
179 // private: called to verify that k is a static member of this nest.
180 // We know that k is an instance class in the same package and hence the
181 // same classloader.
182 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
183 assert(!is_hidden(), "unexpected hidden class");
184 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
185 if (log_is_enabled(Trace, class, nestmates)) {
186 ResourceMark rm(current);
187 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
188 k->external_name(), this->external_name());
189 }
190 return false;
191 }
192
193 if (log_is_enabled(Trace, class, nestmates)) {
194 ResourceMark rm(current);
195 log_trace(class, nestmates)("Checking nest membership of %s in %s",
196 k->external_name(), this->external_name());
197 }
198
199 // Check for the named class in _nest_members.
200 // We don't resolve, or load, any classes.
201 for (int i = 0; i < _nest_members->length(); i++) {
202 int cp_index = _nest_members->at(i);
203 Symbol* name = _constants->klass_name_at(cp_index);
204 if (name == k->name()) {
205 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
206 return true;
207 }
208 }
209 log_trace(class, nestmates)("- class is NOT a nest member!");
210 return false;
211 }
212
213 // Called to verify that k is a permitted subclass of this class.
214 // The incoming stringStream is used to format the messages for error logging and for the caller
215 // to use for exception throwing.
216 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
217 Thread* current = Thread::current();
218 assert(k != nullptr, "sanity check");
219 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
220 "unexpected empty _permitted_subclasses array");
221
222 if (log_is_enabled(Trace, class, sealed)) {
223 ResourceMark rm(current);
224 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
225 k->external_name(), this->external_name());
226 }
227
228 // Check that the class and its super are in the same module.
229 if (k->module() != this->module()) {
230 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
231 "and sealed class %s is in module '%s' with loader %s",
232 k->external_name(),
233 k->module()->name_as_C_string(),
234 k->module()->loader_data()->loader_name_and_id(),
235 this->external_name(),
236 this->module()->name_as_C_string(),
237 this->module()->loader_data()->loader_name_and_id());
238 log_trace(class, sealed)(" - %s", ss.as_string());
239 return false;
240 }
241
242 if (!k->is_public() && !is_same_class_package(k)) {
243 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
244 "and sealed class %s is in package '%s' with classloader %s",
245 k->external_name(),
246 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
247 k->module()->loader_data()->loader_name_and_id(),
248 this->external_name(),
249 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
250 this->module()->loader_data()->loader_name_and_id());
251 log_trace(class, sealed)(" - %s", ss.as_string());
252 return false;
253 }
254
255 for (int i = 0; i < _permitted_subclasses->length(); i++) {
256 int cp_index = _permitted_subclasses->at(i);
257 Symbol* name = _constants->klass_name_at(cp_index);
258 if (name == k->name()) {
259 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
260 return true;
261 }
262 }
263
264 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
265 k->external_name(), this->external_name());
266 log_trace(class, sealed)(" - %s", ss.as_string());
267 return false;
268 }
269
270 // Return nest-host class, resolving, validating and saving it if needed.
271 // In cases where this is called from a thread that cannot do classloading
272 // (such as a native JIT thread) then we simply return null, which in turn
273 // causes the access check to return false. Such code will retry the access
274 // from a more suitable environment later. Otherwise the _nest_host is always
275 // set once this method returns.
276 // Any errors from nest-host resolution must be preserved so they can be queried
277 // from higher-level access checking code, and reported as part of access checking
278 // exceptions.
279 // VirtualMachineErrors are propagated with a null return.
280 // Under any conditions where the _nest_host can be set to non-null the resulting
281 // value of it and, if applicable, the nest host resolution/validation error,
282 // are idempotent.
283 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
284 InstanceKlass* nest_host_k = _nest_host;
285 if (nest_host_k != nullptr) {
286 return nest_host_k;
287 }
288
289 ResourceMark rm(THREAD);
290
291 // need to resolve and save our nest-host class.
292 if (_nest_host_index != 0) { // we have a real nest_host
293 // Before trying to resolve check if we're in a suitable context
294 bool can_resolve = THREAD->can_call_java();
295 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
296 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
297 this->external_name());
298 return nullptr; // sentinel to say "try again from a different context"
299 }
300
301 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
302 this->external_name(),
303 _constants->klass_name_at(_nest_host_index)->as_C_string());
304
305 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
306 if (HAS_PENDING_EXCEPTION) {
307 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
308 return nullptr; // propagate VMEs
309 }
310 stringStream ss;
311 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
312 ss.print("Nest host resolution of %s with host %s failed: ",
313 this->external_name(), target_host_class);
314 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
315 const char* msg = ss.as_string(true /* on C-heap */);
316 constantPoolHandle cph(THREAD, constants());
317 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
318 CLEAR_PENDING_EXCEPTION;
319
320 log_trace(class, nestmates)("%s", msg);
321 } else {
322 // A valid nest-host is an instance class in the current package that lists this
323 // class as a nest member. If any of these conditions are not met the class is
324 // its own nest-host.
325 const char* error = nullptr;
326
327 // JVMS 5.4.4 indicates package check comes first
328 if (is_same_class_package(k)) {
329 // Now check actual membership. We can't be a member if our "host" is
330 // not an instance class.
331 if (k->is_instance_klass()) {
332 nest_host_k = InstanceKlass::cast(k);
333 bool is_member = nest_host_k->has_nest_member(THREAD, this);
334 if (is_member) {
335 _nest_host = nest_host_k; // save resolved nest-host value
336
337 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
338 this->external_name(), k->external_name());
339 return nest_host_k;
340 } else {
341 error = "current type is not listed as a nest member";
342 }
343 } else {
344 error = "host is not an instance class";
345 }
346 } else {
347 error = "types are in different packages";
348 }
349
350 // something went wrong, so record what and log it
351 {
352 stringStream ss;
353 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
354 this->external_name(),
355 this->class_loader_data()->loader_name_and_id(),
356 k->external_name(),
357 k->class_loader_data()->loader_name_and_id(),
358 error);
359 const char* msg = ss.as_string(true /* on C-heap */);
360 constantPoolHandle cph(THREAD, constants());
361 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
362 log_trace(class, nestmates)("%s", msg);
363 }
364 }
365 } else {
366 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
367 this->external_name());
368 }
369
370 // Either not in an explicit nest, or else an error occurred, so
371 // the nest-host is set to `this`. Any thread that sees this assignment
372 // will also see any setting of nest_host_error(), if applicable.
373 return (_nest_host = this);
374 }
375
376 // Dynamic nest member support: set this class's nest host to the given class.
377 // This occurs as part of the class definition, as soon as the instanceKlass
378 // has been created and doesn't require further resolution. The code:
379 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
380 // results in:
381 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
382 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
383 // We also know the "host" is a valid nest-host in the same package so we can
384 // assert some of those facts.
385 void InstanceKlass::set_nest_host(InstanceKlass* host) {
386 assert(is_hidden(), "must be a hidden class");
387 assert(host != nullptr, "null nest host specified");
388 assert(_nest_host == nullptr, "current class has resolved nest-host");
389 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
390 nest_host_error());
391 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
392 (host->_nest_host == host), "proposed host is not a valid nest-host");
393 // Can't assert this as package is not set yet:
394 // assert(is_same_class_package(host), "proposed host is in wrong package");
395
396 if (log_is_enabled(Trace, class, nestmates)) {
397 ResourceMark rm;
398 const char* msg = "";
399 // a hidden class does not expect a statically defined nest-host
400 if (_nest_host_index > 0) {
401 msg = "(the NestHost attribute in the current class is ignored)";
402 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
403 msg = "(the NestMembers attribute in the current class is ignored)";
404 }
405 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
406 this->external_name(),
407 host->external_name(),
408 msg);
409 }
410 // set dynamic nest host
411 _nest_host = host;
412 // Record dependency to keep nest host from being unloaded before this class.
413 ClassLoaderData* this_key = class_loader_data();
414 assert(this_key != nullptr, "sanity");
415 this_key->record_dependency(host);
416 }
417
418 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
419 // or we are k's nest_host - all of which is covered by comparing the two
420 // resolved_nest_hosts.
421 // Any exceptions (i.e. VMEs) are propagated.
422 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
423
424 assert(this != k, "this should be handled by higher-level code");
425
426 // Per JVMS 5.4.4 we first resolve and validate the current class, then
427 // the target class k.
428
429 InstanceKlass* cur_host = nest_host(CHECK_false);
430 if (cur_host == nullptr) {
431 return false;
432 }
433
434 Klass* k_nest_host = k->nest_host(CHECK_false);
435 if (k_nest_host == nullptr) {
436 return false;
437 }
438
439 bool access = (cur_host == k_nest_host);
440
441 ResourceMark rm(THREAD);
442 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
443 this->external_name(),
444 access ? "" : "NOT ",
445 k->external_name());
446 return access;
447 }
448
449 const char* InstanceKlass::nest_host_error() {
450 if (_nest_host_index == 0) {
451 return nullptr;
452 } else {
453 constantPoolHandle cph(Thread::current(), constants());
454 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
455 }
456 }
457
458 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
459 const int size = InstanceKlass::size(parser.vtable_size(),
460 parser.itable_size(),
461 nonstatic_oop_map_size(parser.total_oop_map_count()),
462 parser.is_interface());
463
464 const Symbol* const class_name = parser.class_name();
465 assert(class_name != nullptr, "invariant");
466 ClassLoaderData* loader_data = parser.loader_data();
467 assert(loader_data != nullptr, "invariant");
468
469 InstanceKlass* ik;
470
471 // Allocation
472 if (parser.is_instance_ref_klass()) {
473 // java.lang.ref.Reference
474 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
475 } else if (class_name == vmSymbols::java_lang_Class()) {
476 // mirror - java.lang.Class
477 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
478 } else if (is_stack_chunk_class(class_name, loader_data)) {
479 // stack chunk
480 ik = new (loader_data, size, THREAD) InstanceStackChunkKlass(parser);
481 } else if (is_class_loader(class_name, parser)) {
482 // class loader - java.lang.ClassLoader
483 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
484 } else {
485 // normal
486 ik = new (loader_data, size, THREAD) InstanceKlass(parser);
487 }
488
489 if (ik != nullptr && UseCompressedClassPointers) {
490 assert(CompressedKlassPointers::is_encodable(ik),
491 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
492 }
493
494 // Check for pending exception before adding to the loader data and incrementing
495 // class count. Can get OOM here.
496 if (HAS_PENDING_EXCEPTION) {
497 return nullptr;
498 }
499
500 return ik;
501 }
502
503
504 // copy method ordering from resource area to Metaspace
505 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
506 if (m != nullptr) {
507 // allocate a new array and copy contents (memcpy?)
508 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
509 for (int i = 0; i < m->length(); i++) {
510 _method_ordering->at_put(i, m->at(i));
511 }
512 } else {
513 _method_ordering = Universe::the_empty_int_array();
514 }
515 }
516
517 // create a new array of vtable_indices for default methods
518 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
519 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
520 assert(default_vtable_indices() == nullptr, "only create once");
521 set_default_vtable_indices(vtable_indices);
522 return vtable_indices;
523 }
524
525
526 InstanceKlass::InstanceKlass() {
527 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
528 }
529
530 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
531 Klass(kind),
532 _nest_members(nullptr),
533 _nest_host(nullptr),
534 _permitted_subclasses(nullptr),
535 _record_components(nullptr),
536 _static_field_size(parser.static_field_size()),
537 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
538 _itable_len(parser.itable_size()),
539 _nest_host_index(0),
540 _init_state(allocated),
541 _reference_type(reference_type),
542 _init_thread(nullptr)
543 {
544 set_vtable_length(parser.vtable_size());
545 set_access_flags(parser.access_flags());
546 if (parser.is_hidden()) set_is_hidden();
547 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
548 false));
549
550 assert(nullptr == _methods, "underlying memory not zeroed?");
551 assert(is_instance_klass(), "is layout incorrect?");
552 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
553 }
554
555 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
556 Array<Method*>* methods) {
557 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
558 !methods->in_aot_cache()) {
559 for (int i = 0; i < methods->length(); i++) {
560 Method* method = methods->at(i);
561 if (method == nullptr) continue; // maybe null if error processing
562 // Only want to delete methods that are not executing for RedefineClasses.
563 // The previous version will point to them so they're not totally dangling
564 assert (!method->on_stack(), "shouldn't be called with methods on stack");
565 MetadataFactory::free_metadata(loader_data, method);
566 }
567 MetadataFactory::free_array<Method*>(loader_data, methods);
568 }
569 }
570
571 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
572 const InstanceKlass* super_klass,
573 Array<InstanceKlass*>* local_interfaces,
574 Array<InstanceKlass*>* transitive_interfaces) {
575 // Only deallocate transitive interfaces if not empty, same as super class
576 // or same as local interfaces. See code in parseClassFile.
577 Array<InstanceKlass*>* ti = transitive_interfaces;
578 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
579 // check that the interfaces don't come from super class
580 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
581 super_klass->transitive_interfaces();
582 if (ti != sti && ti != nullptr && !ti->in_aot_cache()) {
583 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
584 }
585 }
586
587 // local interfaces can be empty
588 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
589 local_interfaces != nullptr && !local_interfaces->in_aot_cache()) {
590 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
591 }
592 }
593
594 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
595 Array<RecordComponent*>* record_components) {
596 if (record_components != nullptr && !record_components->in_aot_cache()) {
597 for (int i = 0; i < record_components->length(); i++) {
598 RecordComponent* record_component = record_components->at(i);
599 MetadataFactory::free_metadata(loader_data, record_component);
600 }
601 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
602 }
603 }
604
605 // This function deallocates the metadata and C heap pointers that the
606 // InstanceKlass points to.
607 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
608 // Orphan the mirror first, CMS thinks it's still live.
609 if (java_mirror() != nullptr) {
610 java_lang_Class::set_klass(java_mirror(), nullptr);
611 }
612
613 // Also remove mirror from handles
614 loader_data->remove_handle(_java_mirror);
615
616 // Need to take this class off the class loader data list.
617 loader_data->remove_class(this);
618
619 // The array_klass for this class is created later, after error handling.
620 // For class redefinition, we keep the original class so this scratch class
621 // doesn't have an array class. Either way, assert that there is nothing
622 // to deallocate.
623 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
624
625 // Release C heap allocated data that this points to, which includes
626 // reference counting symbol names.
627 // Can't release the constant pool or MethodData C heap data here because the constant
628 // pool can be deallocated separately from the InstanceKlass for default methods and
629 // redefine classes. MethodData can also be released separately.
630 release_C_heap_structures(/* release_sub_metadata */ false);
631
632 deallocate_methods(loader_data, methods());
633 set_methods(nullptr);
634
635 deallocate_record_components(loader_data, record_components());
636 set_record_components(nullptr);
637
638 if (method_ordering() != nullptr &&
639 method_ordering() != Universe::the_empty_int_array() &&
640 !method_ordering()->in_aot_cache()) {
641 MetadataFactory::free_array<int>(loader_data, method_ordering());
642 }
643 set_method_ordering(nullptr);
644
645 // default methods can be empty
646 if (default_methods() != nullptr &&
647 default_methods() != Universe::the_empty_method_array() &&
648 !default_methods()->in_aot_cache()) {
649 MetadataFactory::free_array<Method*>(loader_data, default_methods());
650 }
651 // Do NOT deallocate the default methods, they are owned by superinterfaces.
652 set_default_methods(nullptr);
653
654 // default methods vtable indices can be empty
655 if (default_vtable_indices() != nullptr &&
656 !default_vtable_indices()->in_aot_cache()) {
657 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
658 }
659 set_default_vtable_indices(nullptr);
660
661
662 // This array is in Klass, but remove it with the InstanceKlass since
663 // this place would be the only caller and it can share memory with transitive
664 // interfaces.
665 if (secondary_supers() != nullptr &&
666 secondary_supers() != Universe::the_empty_klass_array() &&
667 // see comments in compute_secondary_supers about the following cast
668 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
669 !secondary_supers()->in_aot_cache()) {
670 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
671 }
672 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
673
674 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
675 set_transitive_interfaces(nullptr);
676 set_local_interfaces(nullptr);
677
678 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->in_aot_cache()) {
679 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
680 }
681 set_fieldinfo_stream(nullptr);
682
683 if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->in_aot_cache()) {
684 MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
685 }
686 set_fieldinfo_search_table(nullptr);
687
688 if (fields_status() != nullptr && !fields_status()->in_aot_cache()) {
689 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
690 }
691 set_fields_status(nullptr);
692
693 // If a method from a redefined class is using this constant pool, don't
694 // delete it, yet. The new class's previous version will point to this.
695 if (constants() != nullptr) {
696 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
697 if (!constants()->in_aot_cache()) {
698 MetadataFactory::free_metadata(loader_data, constants());
699 }
700 // Delete any cached resolution errors for the constant pool
701 SystemDictionary::delete_resolution_error(constants());
702
703 set_constants(nullptr);
704 }
705
706 if (inner_classes() != nullptr &&
707 inner_classes() != Universe::the_empty_short_array() &&
708 !inner_classes()->in_aot_cache()) {
709 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
710 }
711 set_inner_classes(nullptr);
712
713 if (nest_members() != nullptr &&
714 nest_members() != Universe::the_empty_short_array() &&
715 !nest_members()->in_aot_cache()) {
716 MetadataFactory::free_array<jushort>(loader_data, nest_members());
717 }
718 set_nest_members(nullptr);
719
720 if (permitted_subclasses() != nullptr &&
721 permitted_subclasses() != Universe::the_empty_short_array() &&
722 !permitted_subclasses()->in_aot_cache()) {
723 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
724 }
725 set_permitted_subclasses(nullptr);
726
727 // We should deallocate the Annotations instance if it's not in shared spaces.
728 if (annotations() != nullptr && !annotations()->in_aot_cache()) {
729 MetadataFactory::free_metadata(loader_data, annotations());
730 }
731 set_annotations(nullptr);
732
733 SystemDictionaryShared::handle_class_unloading(this);
734
735 #if INCLUDE_CDS_JAVA_HEAP
736 if (CDSConfig::is_dumping_heap()) {
737 HeapShared::remove_scratch_objects(this);
738 }
739 #endif
740 }
741
742 bool InstanceKlass::is_record() const {
743 return _record_components != nullptr &&
744 is_final() &&
745 super() == vmClasses::Record_klass();
746 }
747
748 bool InstanceKlass::is_sealed() const {
749 return _permitted_subclasses != nullptr &&
750 _permitted_subclasses != Universe::the_empty_short_array();
751 }
752
753 // JLS 8.9: An enum class is either implicitly final and derives
754 // from java.lang.Enum, or else is implicitly sealed to its
755 // anonymous subclasses. This query detects both kinds.
756 // It does not validate the finality or
757 // sealing conditions: it merely checks for a super of Enum.
758 // This is sufficient for recognizing well-formed enums.
759 bool InstanceKlass::is_enum_subclass() const {
760 InstanceKlass* s = super();
761 return (s == vmClasses::Enum_klass() ||
762 (s != nullptr && s->super() == vmClasses::Enum_klass()));
763 }
764
765 bool InstanceKlass::should_be_initialized() const {
766 return !is_initialized();
767 }
768
769 klassItable InstanceKlass::itable() const {
770 return klassItable(const_cast<InstanceKlass*>(this));
771 }
772
773 // JVMTI spec thinks there are signers and protection domain in the
774 // instanceKlass. These accessors pretend these fields are there.
775 // The hprof specification also thinks these fields are in InstanceKlass.
776 oop InstanceKlass::protection_domain() const {
777 // return the protection_domain from the mirror
778 return java_lang_Class::protection_domain(java_mirror());
779 }
780
781 objArrayOop InstanceKlass::signers() const {
782 // return the signers from the mirror
783 return java_lang_Class::signers(java_mirror());
784 }
785
786 oop InstanceKlass::init_lock() const {
787 // return the init lock from the mirror
788 oop lock = java_lang_Class::init_lock(java_mirror());
789 // Prevent reordering with any access of initialization state
790 OrderAccess::loadload();
791 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
792 "only fully initialized state can have a null lock");
793 return lock;
794 }
795
796 // Set the initialization lock to null so the object can be GC'ed. Any racing
797 // threads to get this lock will see a null lock and will not lock.
798 // That's okay because they all check for initialized state after getting
799 // the lock and return.
800 void InstanceKlass::fence_and_clear_init_lock() {
801 // make sure previous stores are all done, notably the init_state.
802 OrderAccess::storestore();
803 java_lang_Class::clear_init_lock(java_mirror());
804 assert(!is_not_initialized(), "class must be initialized now");
805 }
806
807
808 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
809 // process. The step comments refers to the procedure described in that section.
810 // Note: implementation moved to static method to expose the this pointer.
811 void InstanceKlass::initialize(TRAPS) {
812 if (this->should_be_initialized()) {
813 initialize_impl(CHECK);
814 // Note: at this point the class may be initialized
815 // OR it may be in the state of being initialized
816 // in case of recursive initialization!
817 } else {
818 assert(is_initialized(), "sanity check");
819 }
820 }
821
822 #ifdef ASSERT
823 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
824 assert(has_aot_initialized_mirror(), "must be");
825
826 InstanceKlass* s = super();
827 if (s != nullptr) {
828 DEBUG_ONLY(ResourceMark rm);
829 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
830 s->external_name(), external_name());
831 s->assert_no_clinit_will_run_for_aot_initialized_class();
832 }
833
834 Array<InstanceKlass*>* interfaces = local_interfaces();
835 int len = interfaces->length();
836 for (int i = 0; i < len; i++) {
837 InstanceKlass* intf = interfaces->at(i);
838 if (!intf->is_initialized()) {
839 ResourceMark rm;
840 // Note: an interface needs to be marked as is_initialized() only if
841 // - it has a <clinit>
842 // - it has declared a default method.
843 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
844 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
845 intf->external_name(), external_name());
846 }
847 }
848 }
849 #endif
850
851 #if INCLUDE_CDS
852 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
853 assert(has_aot_initialized_mirror(), "must be");
854 assert(CDSConfig::is_loading_heap(), "must be");
855 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
856 assert_no_clinit_will_run_for_aot_initialized_class();
857
858 if (is_initialized()) {
859 return;
860 }
861
862 if (is_runtime_setup_required()) {
863 // Need to take the slow path, which will call the runtimeSetup() function instead
864 // of <clinit>
865 initialize(CHECK);
866 return;
867 }
868 if (log_is_enabled(Info, aot, init)) {
869 ResourceMark rm;
870 log_info(aot, init)("%s (aot-inited)", external_name());
871 }
872
873 link_class(CHECK);
874
875 #ifdef ASSERT
876 {
877 Handle h_init_lock(THREAD, init_lock());
878 ObjectLocker ol(h_init_lock, THREAD);
879 assert(!is_initialized(), "sanity");
880 assert(!is_being_initialized(), "sanity");
881 assert(!is_in_error_state(), "sanity");
882 }
883 #endif
884
885 set_init_thread(THREAD);
886 set_initialization_state_and_notify(fully_initialized, CHECK);
887 }
888 #endif
889
890 bool InstanceKlass::verify_code(TRAPS) {
891 // 1) Verify the bytecodes
892 return Verifier::verify(this, should_verify_class(), THREAD);
893 }
894
895 void InstanceKlass::link_class(TRAPS) {
896 assert(is_loaded(), "must be loaded");
897 if (!is_linked()) {
898 link_class_impl(CHECK);
899 }
900 }
901
902 // Called to verify that a class can link during initialization, without
903 // throwing a VerifyError.
904 bool InstanceKlass::link_class_or_fail(TRAPS) {
905 assert(is_loaded(), "must be loaded");
906 if (!is_linked()) {
907 link_class_impl(CHECK_false);
908 }
909 return is_linked();
910 }
911
912 bool InstanceKlass::link_class_impl(TRAPS) {
913 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
914 // This is for CDS static dump only -- we use the in_error_state to indicate that
915 // the class has failed verification. Throwing the NoClassDefFoundError here is just
916 // a convenient way to stop repeat attempts to verify the same (bad) class.
917 //
918 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
919 // if we are executing Java code. This is not a problem for CDS dumping phase since
920 // it doesn't execute any Java code.
921 ResourceMark rm(THREAD);
922 // Names are all known to be < 64k so we know this formatted message is not excessively large.
923 Exceptions::fthrow(THREAD_AND_LOCATION,
924 vmSymbols::java_lang_NoClassDefFoundError(),
925 "Class %s, or one of its supertypes, failed class initialization",
926 external_name());
927 return false;
928 }
929 // return if already verified
930 if (is_linked()) {
931 return true;
932 }
933
934 // Timing
935 // timer handles recursion
936 JavaThread* jt = THREAD;
937
938 // link super class before linking this class
939 InstanceKlass* super_klass = super();
940 if (super_klass != nullptr) {
941 if (super_klass->is_interface()) { // check if super class is an interface
942 ResourceMark rm(THREAD);
943 // Names are all known to be < 64k so we know this formatted message is not excessively large.
944 Exceptions::fthrow(
945 THREAD_AND_LOCATION,
946 vmSymbols::java_lang_IncompatibleClassChangeError(),
947 "class %s has interface %s as super class",
948 external_name(),
949 super_klass->external_name()
950 );
951 return false;
952 }
953
954 super_klass->link_class_impl(CHECK_false);
955 }
956
957 // link all interfaces implemented by this class before linking this class
958 Array<InstanceKlass*>* interfaces = local_interfaces();
959 int num_interfaces = interfaces->length();
960 for (int index = 0; index < num_interfaces; index++) {
961 InstanceKlass* interk = interfaces->at(index);
962 interk->link_class_impl(CHECK_false);
963 }
964
965 // in case the class is linked in the process of linking its superclasses
966 if (is_linked()) {
967 return true;
968 }
969
970 // trace only the link time for this klass that includes
971 // the verification time
972 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
973 ClassLoader::perf_class_link_selftime(),
974 ClassLoader::perf_classes_linked(),
975 jt->get_thread_stat()->perf_recursion_counts_addr(),
976 jt->get_thread_stat()->perf_timers_addr(),
977 PerfClassTraceTime::CLASS_LINK);
978
979 // verification & rewriting
980 {
981 HandleMark hm(THREAD);
982 Handle h_init_lock(THREAD, init_lock());
983 ObjectLocker ol(h_init_lock, jt);
984 // rewritten will have been set if loader constraint error found
985 // on an earlier link attempt
986 // don't verify or rewrite if already rewritten
987 //
988
989 if (!is_linked()) {
990 if (!is_rewritten()) {
991 if (in_aot_cache()) {
992 assert(!verified_at_dump_time(), "must be");
993 }
994 {
995 bool verify_ok = verify_code(THREAD);
996 if (!verify_ok) {
997 return false;
998 }
999 }
1000
1001 // Just in case a side-effect of verify linked this class already
1002 // (which can sometimes happen since the verifier loads classes
1003 // using custom class loaders, which are free to initialize things)
1004 if (is_linked()) {
1005 return true;
1006 }
1007
1008 // also sets rewritten
1009 rewrite_class(CHECK_false);
1010 } else if (in_aot_cache()) {
1011 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1012 }
1013
1014 // relocate jsrs and link methods after they are all rewritten
1015 link_methods(CHECK_false);
1016
1017 // Initialize the vtable and interface table after
1018 // methods have been rewritten since rewrite may
1019 // fabricate new Method*s.
1020 // also does loader constraint checking
1021 //
1022 // initialize_vtable and initialize_itable need to be rerun
1023 // for a shared class if
1024 // 1) the class is loaded by custom class loader or
1025 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1026 // 3) the class was not verified during dump time
1027 bool need_init_table = true;
1028 if (in_aot_cache() && verified_at_dump_time() &&
1029 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1030 need_init_table = false;
1031 }
1032 if (need_init_table) {
1033 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1034 itable().initialize_itable_and_check_constraints(CHECK_false);
1035 }
1036 #ifdef ASSERT
1037 vtable().verify(tty, true);
1038 // In case itable verification is ever added.
1039 // itable().verify(tty, true);
1040 #endif
1041 if (Universe::is_fully_initialized()) {
1042 DeoptimizationScope deopt_scope;
1043 {
1044 // Now mark all code that assumes the class is not linked.
1045 // Set state under the Compile_lock also.
1046 MutexLocker ml(THREAD, Compile_lock);
1047
1048 set_init_state(linked);
1049 CodeCache::mark_dependents_on(&deopt_scope, this);
1050 }
1051 // Perform the deopt handshake outside Compile_lock.
1052 deopt_scope.deoptimize_marked();
1053 } else {
1054 set_init_state(linked);
1055 }
1056 if (JvmtiExport::should_post_class_prepare()) {
1057 JvmtiExport::post_class_prepare(THREAD, this);
1058 }
1059 }
1060 }
1061 return true;
1062 }
1063
1064 // Rewrite the byte codes of all of the methods of a class.
1065 // The rewriter must be called exactly once. Rewriting must happen after
1066 // verification but before the first method of the class is executed.
1067 void InstanceKlass::rewrite_class(TRAPS) {
1068 assert(is_loaded(), "must be loaded");
1069 if (is_rewritten()) {
1070 assert(in_aot_cache(), "rewriting an unshared class?");
1071 return;
1072 }
1073 Rewriter::rewrite(this, CHECK);
1074 set_rewritten();
1075 }
1076
1077 // Now relocate and link method entry points after class is rewritten.
1078 // This is outside is_rewritten flag. In case of an exception, it can be
1079 // executed more than once.
1080 void InstanceKlass::link_methods(TRAPS) {
1081 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1082
1083 int len = methods()->length();
1084 for (int i = len-1; i >= 0; i--) {
1085 methodHandle m(THREAD, methods()->at(i));
1086
1087 // Set up method entry points for compiler and interpreter .
1088 m->link_method(m, CHECK);
1089 }
1090 }
1091
1092 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1093 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1094 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1095 for (int i = 0; i < local_interfaces()->length(); ++i) {
1096 InstanceKlass* ik = local_interfaces()->at(i);
1097
1098 // Initialization is depth first search ie. we start with top of the inheritance tree
1099 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1100 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1101 if (ik->has_nonstatic_concrete_methods()) {
1102 ik->initialize_super_interfaces(CHECK);
1103 }
1104
1105 // Only initialize() interfaces that "declare" concrete methods.
1106 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1107 ik->initialize(CHECK);
1108 }
1109 }
1110 }
1111
1112 using InitializationErrorTable = HashTable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1113 static InitializationErrorTable* _initialization_error_table;
1114
1115 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1116 // Create the same exception with a message indicating the thread name,
1117 // and the StackTraceElements.
1118 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1119 ResourceMark rm(current);
1120 if (init_error.is_null()) {
1121 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1122
1123 // We failed to create the new exception, most likely due to either out-of-memory or
1124 // a stackoverflow error. If the original exception was either of those then we save
1125 // the shared, pre-allocated, stackless, instance of that exception.
1126 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1127 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1128 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1129 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1130 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1131 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1132 } else {
1133 return;
1134 }
1135 }
1136
1137 MutexLocker ml(current, ClassInitError_lock);
1138 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1139 bool created;
1140 if (_initialization_error_table == nullptr) {
1141 _initialization_error_table = new (mtClass) InitializationErrorTable();
1142 }
1143 _initialization_error_table->put_if_absent(this, elem, &created);
1144 assert(created, "Initialization is single threaded");
1145 log_trace(class, init)("Initialization error added for class %s", external_name());
1146 }
1147
1148 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1149 MutexLocker ml(current, ClassInitError_lock);
1150 if (_initialization_error_table == nullptr) {
1151 return nullptr;
1152 }
1153 OopHandle* h = _initialization_error_table->get(this);
1154 return (h != nullptr) ? h->resolve() : nullptr;
1155 }
1156
1157 // Need to remove entries for unloaded classes.
1158 void InstanceKlass::clean_initialization_error_table() {
1159 struct InitErrorTableCleaner {
1160 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1161 if (!ik->is_loader_alive()) {
1162 h.release(Universe::vm_global());
1163 return true;
1164 } else {
1165 return false;
1166 }
1167 }
1168 };
1169
1170 assert_locked_or_safepoint(ClassInitError_lock);
1171 InitErrorTableCleaner cleaner;
1172 if (_initialization_error_table != nullptr) {
1173 _initialization_error_table->unlink(&cleaner);
1174 }
1175 }
1176
1177 void InstanceKlass::initialize_impl(TRAPS) {
1178 HandleMark hm(THREAD);
1179
1180 // Make sure klass is linked (verified) before initialization
1181 // A class could already be verified, since it has been reflected upon.
1182 link_class(CHECK);
1183
1184 DTRACE_CLASSINIT_PROBE(required, -1);
1185
1186 bool wait = false;
1187
1188 JavaThread* jt = THREAD;
1189
1190 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1191
1192 // refer to the JVM book page 47 for description of steps
1193 // Step 1
1194 {
1195 Handle h_init_lock(THREAD, init_lock());
1196 ObjectLocker ol(h_init_lock, jt);
1197
1198 // Step 2
1199 // If we were to use wait() instead of waitInterruptibly() then
1200 // we might end up throwing IE from link/symbol resolution sites
1201 // that aren't expected to throw. This would wreak havoc. See 6320309.
1202 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1203 if (debug_logging_enabled) {
1204 ResourceMark rm(jt);
1205 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1206 jt->name(), external_name(), init_thread_name());
1207 }
1208 wait = true;
1209 jt->set_class_to_be_initialized(this);
1210 ol.wait_uninterruptibly(jt);
1211 jt->set_class_to_be_initialized(nullptr);
1212 }
1213
1214 // Step 3
1215 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1216 if (debug_logging_enabled) {
1217 ResourceMark rm(jt);
1218 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1219 jt->name(), external_name());
1220 }
1221 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1222 return;
1223 }
1224
1225 // Step 4
1226 if (is_initialized()) {
1227 if (debug_logging_enabled) {
1228 ResourceMark rm(jt);
1229 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1230 jt->name(), external_name());
1231 }
1232 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1233 return;
1234 }
1235
1236 // Step 5
1237 if (is_in_error_state()) {
1238 if (debug_logging_enabled) {
1239 ResourceMark rm(jt);
1240 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1241 jt->name(), external_name());
1242 }
1243
1244 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1245 ResourceMark rm(THREAD);
1246 Handle cause(THREAD, get_initialization_error(THREAD));
1247
1248 stringStream ss;
1249 ss.print("Could not initialize class %s", external_name());
1250 if (cause.is_null()) {
1251 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1252 } else {
1253 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1254 ss.as_string(), cause);
1255 }
1256 } else {
1257
1258 // Step 6
1259 set_init_state(being_initialized);
1260 set_init_thread(jt);
1261 if (debug_logging_enabled) {
1262 ResourceMark rm(jt);
1263 log_debug(class, init)("Thread \"%s\" is initializing %s",
1264 jt->name(), external_name());
1265 }
1266 }
1267 }
1268
1269 // Step 7
1270 // Next, if C is a class rather than an interface, initialize it's super class and super
1271 // interfaces.
1272 if (!is_interface()) {
1273 Klass* super_klass = super();
1274 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1275 super_klass->initialize(THREAD);
1276 }
1277 // If C implements any interface that declares a non-static, concrete method,
1278 // the initialization of C triggers initialization of its super interfaces.
1279 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1280 // having a superinterface that declares, non-static, concrete methods
1281 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1282 initialize_super_interfaces(THREAD);
1283 }
1284
1285 // If any exceptions, complete abruptly, throwing the same exception as above.
1286 if (HAS_PENDING_EXCEPTION) {
1287 Handle e(THREAD, PENDING_EXCEPTION);
1288 CLEAR_PENDING_EXCEPTION;
1289 {
1290 EXCEPTION_MARK;
1291 add_initialization_error(THREAD, e);
1292 // Locks object, set state, and notify all waiting threads
1293 set_initialization_state_and_notify(initialization_error, THREAD);
1294 CLEAR_PENDING_EXCEPTION;
1295 }
1296 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1297 THROW_OOP(e());
1298 }
1299 }
1300
1301
1302 // Step 8
1303 {
1304 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1305 if (class_initializer() != nullptr) {
1306 // Timer includes any side effects of class initialization (resolution,
1307 // etc), but not recursive entry into call_class_initializer().
1308 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1309 ClassLoader::perf_class_init_selftime(),
1310 ClassLoader::perf_classes_inited(),
1311 jt->get_thread_stat()->perf_recursion_counts_addr(),
1312 jt->get_thread_stat()->perf_timers_addr(),
1313 PerfClassTraceTime::CLASS_CLINIT);
1314 call_class_initializer(THREAD);
1315 } else {
1316 // The elapsed time is so small it's not worth counting.
1317 if (UsePerfData) {
1318 ClassLoader::perf_classes_inited()->inc();
1319 }
1320 call_class_initializer(THREAD);
1321 }
1322 }
1323
1324 // Step 9
1325 if (!HAS_PENDING_EXCEPTION) {
1326 set_initialization_state_and_notify(fully_initialized, CHECK);
1327 DEBUG_ONLY(vtable().verify(tty, true);)
1328 CompilationPolicy::replay_training_at_init(this, THREAD);
1329 }
1330 else {
1331 // Step 10 and 11
1332 Handle e(THREAD, PENDING_EXCEPTION);
1333 CLEAR_PENDING_EXCEPTION;
1334 // JVMTI has already reported the pending exception
1335 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1336 JvmtiExport::clear_detected_exception(jt);
1337 {
1338 EXCEPTION_MARK;
1339 add_initialization_error(THREAD, e);
1340 set_initialization_state_and_notify(initialization_error, THREAD);
1341 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1342 // JVMTI has already reported the pending exception
1343 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1344 JvmtiExport::clear_detected_exception(jt);
1345 }
1346 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1347 if (e->is_a(vmClasses::Error_klass())) {
1348 THROW_OOP(e());
1349 } else {
1350 JavaCallArguments args(e);
1351 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1352 vmSymbols::throwable_void_signature(),
1353 &args);
1354 }
1355 }
1356 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1357 }
1358
1359
1360 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1361 Handle h_init_lock(THREAD, init_lock());
1362 if (h_init_lock() != nullptr) {
1363 ObjectLocker ol(h_init_lock, THREAD);
1364 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1365 set_init_state(state);
1366 fence_and_clear_init_lock();
1367 ol.notify_all(CHECK);
1368 } else {
1369 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1370 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1371 set_init_state(state);
1372 }
1373 }
1374
1375 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1376 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1377 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1378 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1379
1380 DeoptimizationScope deopt_scope;
1381 {
1382 MutexLocker ml(current, Compile_lock);
1383
1384 set_init_state(InstanceKlass::loaded);
1385 // make sure init_state store is already done.
1386 // The compiler reads the hierarchy outside of the Compile_lock.
1387 // Access ordering is used to add to hierarchy.
1388
1389 // Link into hierarchy.
1390 append_to_sibling_list(); // add to superklass/sibling list
1391 process_interfaces(); // handle all "implements" declarations
1392
1393 // Now mark all code that depended on old class hierarchy.
1394 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1395 if (Universe::is_fully_initialized()) {
1396 CodeCache::mark_dependents_on(&deopt_scope, this);
1397 }
1398 }
1399 // Perform the deopt handshake outside Compile_lock.
1400 deopt_scope.deoptimize_marked();
1401 }
1402
1403
1404 InstanceKlass* InstanceKlass::implementor() const {
1405 InstanceKlass* volatile* ik = adr_implementor();
1406 if (ik == nullptr) {
1407 return nullptr;
1408 } else {
1409 // This load races with inserts, and therefore needs acquire.
1410 InstanceKlass* ikls = AtomicAccess::load_acquire(ik);
1411 if (ikls != nullptr && !ikls->is_loader_alive()) {
1412 return nullptr; // don't return unloaded class
1413 } else {
1414 return ikls;
1415 }
1416 }
1417 }
1418
1419
1420 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1421 assert_locked_or_safepoint(Compile_lock);
1422 assert(is_interface(), "not interface");
1423 InstanceKlass* volatile* addr = adr_implementor();
1424 assert(addr != nullptr, "null addr");
1425 if (addr != nullptr) {
1426 AtomicAccess::release_store(addr, ik);
1427 }
1428 }
1429
1430 int InstanceKlass::nof_implementors() const {
1431 InstanceKlass* ik = implementor();
1432 if (ik == nullptr) {
1433 return 0;
1434 } else if (ik != this) {
1435 return 1;
1436 } else {
1437 return 2;
1438 }
1439 }
1440
1441 // The embedded _implementor field can only record one implementor.
1442 // When there are more than one implementors, the _implementor field
1443 // is set to the interface Klass* itself. Following are the possible
1444 // values for the _implementor field:
1445 // null - no implementor
1446 // implementor Klass* - one implementor
1447 // self - more than one implementor
1448 //
1449 // The _implementor field only exists for interfaces.
1450 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1451 if (Universe::is_fully_initialized()) {
1452 assert_lock_strong(Compile_lock);
1453 }
1454 assert(is_interface(), "not interface");
1455 // Filter out my subinterfaces.
1456 // (Note: Interfaces are never on the subklass list.)
1457 if (ik->is_interface()) return;
1458
1459 // Filter out subclasses whose supers already implement me.
1460 // (Note: CHA must walk subclasses of direct implementors
1461 // in order to locate indirect implementors.)
1462 InstanceKlass* super_ik = ik->super();
1463 if (super_ik != nullptr && super_ik->implements_interface(this))
1464 // We only need to check one immediate superclass, since the
1465 // implements_interface query looks at transitive_interfaces.
1466 // Any supers of the super have the same (or fewer) transitive_interfaces.
1467 return;
1468
1469 InstanceKlass* iklass = implementor();
1470 if (iklass == nullptr) {
1471 set_implementor(ik);
1472 } else if (iklass != this && iklass != ik) {
1473 // There is already an implementor. Use itself as an indicator of
1474 // more than one implementors.
1475 set_implementor(this);
1476 }
1477
1478 // The implementor also implements the transitive_interfaces
1479 for (int index = 0; index < local_interfaces()->length(); index++) {
1480 local_interfaces()->at(index)->add_implementor(ik);
1481 }
1482 }
1483
1484 void InstanceKlass::init_implementor() {
1485 if (is_interface()) {
1486 set_implementor(nullptr);
1487 }
1488 }
1489
1490
1491 void InstanceKlass::process_interfaces() {
1492 // link this class into the implementors list of every interface it implements
1493 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1494 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1495 InstanceKlass* interf = local_interfaces()->at(i);
1496 assert(interf->is_interface(), "expected interface");
1497 interf->add_implementor(this);
1498 }
1499 }
1500
1501 bool InstanceKlass::can_be_primary_super_slow() const {
1502 if (is_interface())
1503 return false;
1504 else
1505 return Klass::can_be_primary_super_slow();
1506 }
1507
1508 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1509 Array<InstanceKlass*>* transitive_interfaces) {
1510 // The secondaries are the implemented interfaces.
1511 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1512 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1513 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1514 int num_secondaries = num_extra_slots + interfaces->length();
1515 if (num_secondaries == 0) {
1516 // Must share this for correct bootstrapping!
1517 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1518 return nullptr;
1519 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1520 // We will reuse the transitive interfaces list if we're certain
1521 // it's in hash order.
1522 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1523 set_secondary_supers(interfaces, bitmap);
1524 return nullptr;
1525 }
1526 // Copy transitive interfaces to a temporary growable array to be constructed
1527 // into the secondary super list with extra slots.
1528 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1529 for (int i = 0; i < interfaces->length(); i++) {
1530 secondaries->push(interfaces->at(i));
1531 }
1532 return secondaries;
1533 }
1534
1535 bool InstanceKlass::implements_interface(Klass* k) const {
1536 if (this == k) return true;
1537 assert(k->is_interface(), "should be an interface class");
1538 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1539 if (transitive_interfaces()->at(i) == k) {
1540 return true;
1541 }
1542 }
1543 return false;
1544 }
1545
1546 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1547 // Verify direct super interface
1548 if (this == k) return true;
1549 assert(k->is_interface(), "should be an interface class");
1550 for (int i = 0; i < local_interfaces()->length(); i++) {
1551 if (local_interfaces()->at(i) == k) {
1552 return true;
1553 }
1554 }
1555 return false;
1556 }
1557
1558 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1559 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1560 size_t size = objArrayOopDesc::object_size(length);
1561 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1562 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1563 /* do_zero */ true, CHECK_NULL);
1564 return o;
1565 }
1566
1567 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1568 if (TraceFinalizerRegistration) {
1569 tty->print("Registered ");
1570 i->print_value_on(tty);
1571 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1572 }
1573 instanceHandle h_i(THREAD, i);
1574 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1575 JavaValue result(T_VOID);
1576 JavaCallArguments args(h_i);
1577 methodHandle mh(THREAD, Universe::finalizer_register_method());
1578 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1579 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1580 return h_i();
1581 }
1582
1583 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1584 assert(!is_abstract() && !is_interface(), "Should not create this object");
1585 size_t size = size_helper(); // Query before forming handle.
1586 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1587 }
1588
1589 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1590 Klass* k = java_lang_Class::as_Klass(java_class);
1591 if (k == nullptr) {
1592 ResourceMark rm(THREAD);
1593 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1594 }
1595 InstanceKlass* ik = cast(k);
1596 ik->check_valid_for_instantiation(false, CHECK_NULL);
1597 ik->initialize(CHECK_NULL);
1598 return ik->allocate_instance(THREAD);
1599 }
1600
1601 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1602 return instanceHandle(THREAD, allocate_instance(THREAD));
1603 }
1604
1605 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1606 if (is_interface() || is_abstract()) {
1607 ResourceMark rm(THREAD);
1608 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1609 : vmSymbols::java_lang_InstantiationException(), external_name());
1610 }
1611 if (this == vmClasses::Class_klass()) {
1612 ResourceMark rm(THREAD);
1613 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1614 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1615 }
1616 }
1617
1618 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1619 // Need load-acquire for lock-free read
1620 if (array_klasses_acquire() == nullptr) {
1621
1622 // Recursively lock array allocation
1623 RecursiveLocker rl(MultiArray_lock, THREAD);
1624
1625 // Check if another thread created the array klass while we were waiting for the lock.
1626 if (array_klasses() == nullptr) {
1627 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1628 // use 'release' to pair with lock-free load
1629 release_set_array_klasses(k);
1630 }
1631 }
1632
1633 // array_klasses() will always be set at this point
1634 ObjArrayKlass* ak = array_klasses();
1635 assert(ak != nullptr, "should be set");
1636 return ak->array_klass(n, THREAD);
1637 }
1638
1639 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1640 // Need load-acquire for lock-free read
1641 ObjArrayKlass* oak = array_klasses_acquire();
1642 if (oak == nullptr) {
1643 return nullptr;
1644 } else {
1645 return oak->array_klass_or_null(n);
1646 }
1647 }
1648
1649 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1650 return array_klass(1, THREAD);
1651 }
1652
1653 ArrayKlass* InstanceKlass::array_klass_or_null() {
1654 return array_klass_or_null(1);
1655 }
1656
1657 static int call_class_initializer_counter = 0; // for debugging
1658
1659 Method* InstanceKlass::class_initializer() const {
1660 Method* clinit = find_method(
1661 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1662 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1663 return clinit;
1664 }
1665 return nullptr;
1666 }
1667
1668 void InstanceKlass::call_class_initializer(TRAPS) {
1669 if (ReplayCompiles &&
1670 (ReplaySuppressInitializers == 1 ||
1671 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1672 // Hide the existence of the initializer for the purpose of replaying the compile
1673 return;
1674 }
1675
1676 #if INCLUDE_CDS
1677 // This is needed to ensure the consistency of the archived heap objects.
1678 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1679 AOTClassInitializer::call_runtime_setup(THREAD, this);
1680 return;
1681 } else if (has_archived_enum_objs()) {
1682 assert(in_aot_cache(), "must be");
1683 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1684 if (initialized) {
1685 return;
1686 }
1687 }
1688 #endif
1689
1690 methodHandle h_method(THREAD, class_initializer());
1691 assert(!is_initialized(), "we cannot initialize twice");
1692 LogTarget(Info, class, init) lt;
1693 if (lt.is_enabled()) {
1694 ResourceMark rm(THREAD);
1695 LogStream ls(lt);
1696 ls.print("%d Initializing ", call_class_initializer_counter++);
1697 name()->print_value_on(&ls);
1698 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1699 h_method() == nullptr ? "(no method)" : "", p2i(this),
1700 THREAD->name());
1701 }
1702 if (h_method() != nullptr) {
1703 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1704 JavaCallArguments args; // No arguments
1705 JavaValue result(T_VOID);
1706 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1707 }
1708 }
1709
1710 // If a class that implements this interface is initialized, is the JVM required
1711 // to first execute a <clinit> method declared in this interface,
1712 // or (if also_check_supers==true) any of the super types of this interface?
1713 //
1714 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1715 // an interface, then let SC be its superclass and let SI1, ..., SIn
1716 // be all superinterfaces of C (whether direct or indirect) that
1717 // declare at least one non-abstract, non-static method.
1718 //
1719 // So when an interface is initialized, it does not look at its
1720 // supers. But a proper class will ensure that all of its supers have
1721 // run their <clinit> methods, except that it disregards interfaces
1722 // that lack a non-static concrete method (i.e., a default method).
1723 // Therefore, you should probably call this method only when the
1724 // current class is a super of some proper class, not an interface.
1725 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1726 assert(is_interface(), "must be");
1727
1728 if (!has_nonstatic_concrete_methods()) {
1729 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1730 return false;
1731 }
1732
1733 // JVMS 5.5. Initialization
1734 // ...If C is an interface that declares a non-abstract,
1735 // non-static method, the initialization of a class that
1736 // implements C directly or indirectly.
1737 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1738 return true;
1739 }
1740 if (also_check_supers) {
1741 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1742 for (int i = 0; i < all_ifs->length(); ++i) {
1743 InstanceKlass* super_intf = all_ifs->at(i);
1744 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1745 return true;
1746 }
1747 }
1748 }
1749 return false;
1750 }
1751
1752 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1753 InterpreterOopMap* entry_for) {
1754 // Lazily create the _oop_map_cache at first request.
1755 // Load_acquire is needed to safely get instance published with CAS by another thread.
1756 OopMapCache* oop_map_cache = AtomicAccess::load_acquire(&_oop_map_cache);
1757 if (oop_map_cache == nullptr) {
1758 // Try to install new instance atomically.
1759 oop_map_cache = new OopMapCache();
1760 OopMapCache* other = AtomicAccess::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1761 if (other != nullptr) {
1762 // Someone else managed to install before us, ditch local copy and use the existing one.
1763 delete oop_map_cache;
1764 oop_map_cache = other;
1765 }
1766 }
1767 // _oop_map_cache is constant after init; lookup below does its own locking.
1768 oop_map_cache->lookup(method, bci, entry_for);
1769 }
1770
1771 bool InstanceKlass::contains_field_offset(int offset) {
1772 fieldDescriptor fd;
1773 return find_field_from_offset(offset, false, &fd);
1774 }
1775
1776 FieldInfo InstanceKlass::field(int index) const {
1777 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1778 if (fs.index() == index) {
1779 return fs.to_FieldInfo();
1780 }
1781 }
1782 fatal("Field not found");
1783 return FieldInfo();
1784 }
1785
1786 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1787 JavaFieldStream fs(this);
1788 if (fs.lookup(name, sig)) {
1789 assert(fs.name() == name, "name must match");
1790 assert(fs.signature() == sig, "signature must match");
1791 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1792 return true;
1793 }
1794 return false;
1795 }
1796
1797
1798 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1799 const int n = local_interfaces()->length();
1800 for (int i = 0; i < n; i++) {
1801 InstanceKlass* intf1 = local_interfaces()->at(i);
1802 assert(intf1->is_interface(), "just checking type");
1803 // search for field in current interface
1804 if (intf1->find_local_field(name, sig, fd)) {
1805 assert(fd->is_static(), "interface field must be static");
1806 return intf1;
1807 }
1808 // search for field in direct superinterfaces
1809 Klass* intf2 = intf1->find_interface_field(name, sig, fd);
1810 if (intf2 != nullptr) return intf2;
1811 }
1812 // otherwise field lookup fails
1813 return nullptr;
1814 }
1815
1816
1817 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1818 // search order according to newest JVM spec (5.4.3.2, p.167).
1819 // 1) search for field in current klass
1820 if (find_local_field(name, sig, fd)) {
1821 return const_cast<InstanceKlass*>(this);
1822 }
1823 // 2) search for field recursively in direct superinterfaces
1824 { Klass* intf = find_interface_field(name, sig, fd);
1825 if (intf != nullptr) return intf;
1826 }
1827 // 3) apply field lookup recursively if superclass exists
1828 { InstanceKlass* supr = super();
1829 if (supr != nullptr) return supr->find_field(name, sig, fd);
1830 }
1831 // 4) otherwise field lookup fails
1832 return nullptr;
1833 }
1834
1835
1836 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1837 // search order according to newest JVM spec (5.4.3.2, p.167).
1838 // 1) search for field in current klass
1839 if (find_local_field(name, sig, fd)) {
1840 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1841 }
1842 // 2) search for field recursively in direct superinterfaces
1843 if (is_static) {
1844 Klass* intf = find_interface_field(name, sig, fd);
1845 if (intf != nullptr) return intf;
1846 }
1847 // 3) apply field lookup recursively if superclass exists
1848 { InstanceKlass* supr = super();
1849 if (supr != nullptr) return supr->find_field(name, sig, is_static, fd);
1850 }
1851 // 4) otherwise field lookup fails
1852 return nullptr;
1853 }
1854
1855
1856 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1857 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1858 if (fs.offset() == offset) {
1859 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1860 if (fd->is_static() == is_static) return true;
1861 }
1862 }
1863 return false;
1864 }
1865
1866
1867 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1868 const InstanceKlass* klass = this;
1869 while (klass != nullptr) {
1870 if (klass->find_local_field_from_offset(offset, is_static, fd)) {
1871 return true;
1872 }
1873 klass = klass->super();
1874 }
1875 return false;
1876 }
1877
1878
1879 void InstanceKlass::methods_do(void f(Method* method)) {
1880 // Methods aren't stable until they are loaded. This can be read outside
1881 // a lock through the ClassLoaderData for profiling
1882 // Redefined scratch classes are on the list and need to be cleaned
1883 if (!is_loaded() && !is_scratch_class()) {
1884 return;
1885 }
1886
1887 int len = methods()->length();
1888 for (int index = 0; index < len; index++) {
1889 Method* m = methods()->at(index);
1890 assert(m->is_method(), "must be method");
1891 f(m);
1892 }
1893 }
1894
1895
1896 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1897 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1898 if (fs.access_flags().is_static()) {
1899 fieldDescriptor& fd = fs.field_descriptor();
1900 cl->do_field(&fd);
1901 }
1902 }
1903 }
1904
1905
1906 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1907 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1908 if (fs.access_flags().is_static()) {
1909 fieldDescriptor& fd = fs.field_descriptor();
1910 f(&fd, mirror, CHECK);
1911 }
1912 }
1913 }
1914
1915 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1916 InstanceKlass* super = this->super();
1917 if (super != nullptr) {
1918 super->do_nonstatic_fields(cl);
1919 }
1920 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1921 fieldDescriptor& fd = fs.field_descriptor();
1922 if (!fd.is_static()) {
1923 cl->do_field(&fd);
1924 }
1925 }
1926 }
1927
1928 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1929 return a->offset() - b->offset();
1930 }
1931
1932 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1933 InstanceKlass* super = this->super();
1934 if (super != nullptr) {
1935 super->print_nonstatic_fields(cl);
1936 }
1937 ResourceMark rm;
1938 // In DebugInfo nonstatic fields are sorted by offset.
1939 GrowableArray<FieldInfo> fields_sorted;
1940 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1941 if (!fs.access_flags().is_static()) {
1942 fields_sorted.push(fs.to_FieldInfo());
1943 }
1944 }
1945 int length = fields_sorted.length();
1946 if (length > 0) {
1947 fields_sorted.sort(compare_fields_by_offset);
1948 fieldDescriptor fd;
1949 for (int i = 0; i < length; i++) {
1950 fd.reinitialize(this, fields_sorted.at(i));
1951 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1952 cl->do_field(&fd);
1953 }
1954 }
1955 }
1956
1957 #ifdef ASSERT
1958 static int linear_search(const Array<Method*>* methods,
1959 const Symbol* name,
1960 const Symbol* signature) {
1961 const int len = methods->length();
1962 for (int index = 0; index < len; index++) {
1963 const Method* const m = methods->at(index);
1964 assert(m->is_method(), "must be method");
1965 if (m->signature() == signature && m->name() == name) {
1966 return index;
1967 }
1968 }
1969 return -1;
1970 }
1971 #endif
1972
1973 bool InstanceKlass::_disable_method_binary_search = false;
1974
1975 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1976 int len = methods->length();
1977 int l = 0;
1978 int h = len - 1;
1979 while (l <= h) {
1980 Method* m = methods->at(l);
1981 if (m->name() == name) {
1982 return l;
1983 }
1984 l++;
1985 }
1986 return -1;
1987 }
1988
1989 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1990 if (_disable_method_binary_search) {
1991 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1992 // At the final stage of dynamic dumping, the methods array may not be sorted
1993 // by ascending addresses of their names, so we can't use binary search anymore.
1994 // However, methods with the same name are still laid out consecutively inside the
1995 // methods array, so let's look for the first one that matches.
1996 return linear_search(methods, name);
1997 }
1998
1999 int len = methods->length();
2000 int l = 0;
2001 int h = len - 1;
2002
2003 // methods are sorted by ascending addresses of their names, so do binary search
2004 while (l <= h) {
2005 int mid = (l + h) >> 1;
2006 Method* m = methods->at(mid);
2007 assert(m->is_method(), "must be method");
2008 int res = m->name()->fast_compare(name);
2009 if (res == 0) {
2010 return mid;
2011 } else if (res < 0) {
2012 l = mid + 1;
2013 } else {
2014 h = mid - 1;
2015 }
2016 }
2017 return -1;
2018 }
2019
2020 // find_method looks up the name/signature in the local methods array
2021 Method* InstanceKlass::find_method(const Symbol* name,
2022 const Symbol* signature) const {
2023 return find_method_impl(name, signature,
2024 OverpassLookupMode::find,
2025 StaticLookupMode::find,
2026 PrivateLookupMode::find);
2027 }
2028
2029 Method* InstanceKlass::find_method_impl(const Symbol* name,
2030 const Symbol* signature,
2031 OverpassLookupMode overpass_mode,
2032 StaticLookupMode static_mode,
2033 PrivateLookupMode private_mode) const {
2034 return InstanceKlass::find_method_impl(methods(),
2035 name,
2036 signature,
2037 overpass_mode,
2038 static_mode,
2039 private_mode);
2040 }
2041
2042 // find_instance_method looks up the name/signature in the local methods array
2043 // and skips over static methods
2044 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2045 const Symbol* name,
2046 const Symbol* signature,
2047 PrivateLookupMode private_mode) {
2048 Method* const meth = InstanceKlass::find_method_impl(methods,
2049 name,
2050 signature,
2051 OverpassLookupMode::find,
2052 StaticLookupMode::skip,
2053 private_mode);
2054 assert(((meth == nullptr) || !meth->is_static()),
2055 "find_instance_method should have skipped statics");
2056 return meth;
2057 }
2058
2059 // find_instance_method looks up the name/signature in the local methods array
2060 // and skips over static methods
2061 Method* InstanceKlass::find_instance_method(const Symbol* name,
2062 const Symbol* signature,
2063 PrivateLookupMode private_mode) const {
2064 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2065 }
2066
2067 // Find looks up the name/signature in the local methods array
2068 // and filters on the overpass, static and private flags
2069 // This returns the first one found
2070 // note that the local methods array can have up to one overpass, one static
2071 // and one instance (private or not) with the same name/signature
2072 Method* InstanceKlass::find_local_method(const Symbol* name,
2073 const Symbol* signature,
2074 OverpassLookupMode overpass_mode,
2075 StaticLookupMode static_mode,
2076 PrivateLookupMode private_mode) const {
2077 return InstanceKlass::find_method_impl(methods(),
2078 name,
2079 signature,
2080 overpass_mode,
2081 static_mode,
2082 private_mode);
2083 }
2084
2085 // Find looks up the name/signature in the local methods array
2086 // and filters on the overpass, static and private flags
2087 // This returns the first one found
2088 // note that the local methods array can have up to one overpass, one static
2089 // and one instance (private or not) with the same name/signature
2090 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2091 const Symbol* name,
2092 const Symbol* signature,
2093 OverpassLookupMode overpass_mode,
2094 StaticLookupMode static_mode,
2095 PrivateLookupMode private_mode) {
2096 return InstanceKlass::find_method_impl(methods,
2097 name,
2098 signature,
2099 overpass_mode,
2100 static_mode,
2101 private_mode);
2102 }
2103
2104 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2105 const Symbol* name,
2106 const Symbol* signature) {
2107 return InstanceKlass::find_method_impl(methods,
2108 name,
2109 signature,
2110 OverpassLookupMode::find,
2111 StaticLookupMode::find,
2112 PrivateLookupMode::find);
2113 }
2114
2115 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2116 const Symbol* name,
2117 const Symbol* signature,
2118 OverpassLookupMode overpass_mode,
2119 StaticLookupMode static_mode,
2120 PrivateLookupMode private_mode) {
2121 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2122 return hit >= 0 ? methods->at(hit): nullptr;
2123 }
2124
2125 // true if method matches signature and conforms to skipping_X conditions.
2126 static bool method_matches(const Method* m,
2127 const Symbol* signature,
2128 bool skipping_overpass,
2129 bool skipping_static,
2130 bool skipping_private) {
2131 return ((m->signature() == signature) &&
2132 (!skipping_overpass || !m->is_overpass()) &&
2133 (!skipping_static || !m->is_static()) &&
2134 (!skipping_private || !m->is_private()));
2135 }
2136
2137 // Used directly for default_methods to find the index into the
2138 // default_vtable_indices, and indirectly by find_method
2139 // find_method_index looks in the local methods array to return the index
2140 // of the matching name/signature. If, overpass methods are being ignored,
2141 // the search continues to find a potential non-overpass match. This capability
2142 // is important during method resolution to prefer a static method, for example,
2143 // over an overpass method.
2144 // There is the possibility in any _method's array to have the same name/signature
2145 // for a static method, an overpass method and a local instance method
2146 // To correctly catch a given method, the search criteria may need
2147 // to explicitly skip the other two. For local instance methods, it
2148 // is often necessary to skip private methods
2149 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2150 const Symbol* name,
2151 const Symbol* signature,
2152 OverpassLookupMode overpass_mode,
2153 StaticLookupMode static_mode,
2154 PrivateLookupMode private_mode) {
2155 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2156 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2157 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2158 const int hit = quick_search(methods, name);
2159 if (hit != -1) {
2160 const Method* const m = methods->at(hit);
2161
2162 // Do linear search to find matching signature. First, quick check
2163 // for common case, ignoring overpasses if requested.
2164 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2165 return hit;
2166 }
2167
2168 // search downwards through overloaded methods
2169 int i;
2170 for (i = hit - 1; i >= 0; --i) {
2171 const Method* const m = methods->at(i);
2172 assert(m->is_method(), "must be method");
2173 if (m->name() != name) {
2174 break;
2175 }
2176 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2177 return i;
2178 }
2179 }
2180 // search upwards
2181 for (i = hit + 1; i < methods->length(); ++i) {
2182 const Method* const m = methods->at(i);
2183 assert(m->is_method(), "must be method");
2184 if (m->name() != name) {
2185 break;
2186 }
2187 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2188 return i;
2189 }
2190 }
2191 // not found
2192 #ifdef ASSERT
2193 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2194 linear_search(methods, name, signature);
2195 assert(-1 == index, "binary search should have found entry %d", index);
2196 #endif
2197 }
2198 return -1;
2199 }
2200
2201 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2202 return find_method_by_name(methods(), name, end);
2203 }
2204
2205 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2206 const Symbol* name,
2207 int* end_ptr) {
2208 assert(end_ptr != nullptr, "just checking");
2209 int start = quick_search(methods, name);
2210 int end = start + 1;
2211 if (start != -1) {
2212 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2213 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2214 *end_ptr = end;
2215 return start;
2216 }
2217 return -1;
2218 }
2219
2220 // uncached_lookup_method searches both the local class methods array and all
2221 // superclasses methods arrays, skipping any overpass methods in superclasses,
2222 // and possibly skipping private methods.
2223 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2224 const Symbol* signature,
2225 OverpassLookupMode overpass_mode,
2226 PrivateLookupMode private_mode) const {
2227 OverpassLookupMode overpass_local_mode = overpass_mode;
2228 const InstanceKlass* klass = this;
2229 while (klass != nullptr) {
2230 Method* const method = klass->find_method_impl(name,
2231 signature,
2232 overpass_local_mode,
2233 StaticLookupMode::find,
2234 private_mode);
2235 if (method != nullptr) {
2236 return method;
2237 }
2238 klass = klass->super();
2239 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2240 }
2241 return nullptr;
2242 }
2243
2244 #ifdef ASSERT
2245 // search through class hierarchy and return true if this class or
2246 // one of the superclasses was redefined
2247 bool InstanceKlass::has_redefined_this_or_super() const {
2248 const InstanceKlass* klass = this;
2249 while (klass != nullptr) {
2250 if (klass->has_been_redefined()) {
2251 return true;
2252 }
2253 klass = klass->super();
2254 }
2255 return false;
2256 }
2257 #endif
2258
2259 // lookup a method in the default methods list then in all transitive interfaces
2260 // Do NOT return private or static methods
2261 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2262 Symbol* signature) const {
2263 Method* m = nullptr;
2264 if (default_methods() != nullptr) {
2265 m = find_method(default_methods(), name, signature);
2266 }
2267 // Look up interfaces
2268 if (m == nullptr) {
2269 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2270 }
2271 return m;
2272 }
2273
2274 // lookup a method in all the interfaces that this class implements
2275 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2276 // They should only be found in the initial InterfaceMethodRef
2277 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2278 Symbol* signature,
2279 DefaultsLookupMode defaults_mode) const {
2280 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2281 int num_ifs = all_ifs->length();
2282 InstanceKlass *ik = nullptr;
2283 for (int i = 0; i < num_ifs; i++) {
2284 ik = all_ifs->at(i);
2285 Method* m = ik->lookup_method(name, signature);
2286 if (m != nullptr && m->is_public() && !m->is_static() &&
2287 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2288 return m;
2289 }
2290 }
2291 return nullptr;
2292 }
2293
2294 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2295 :_st(st), _verbose(verbose) {
2296 ResourceMark rm;
2297 _st->print("%-18s ", "KlassAddr");
2298 _st->print("%-4s ", "Size");
2299 _st->print("%-20s ", "State");
2300 _st->print("%-7s ", "Flags");
2301 _st->print("%-5s ", "ClassName");
2302 _st->cr();
2303 }
2304
2305 void PrintClassClosure::do_klass(Klass* k) {
2306 ResourceMark rm;
2307 // klass pointer
2308 _st->print(PTR_FORMAT " ", p2i(k));
2309 // klass size
2310 _st->print("%4d ", k->size());
2311 // initialization state
2312 if (k->is_instance_klass()) {
2313 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2314 } else {
2315 _st->print("%-20s ","");
2316 }
2317 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2318 char buf[10];
2319 int i = 0;
2320 if (k->has_finalizer()) buf[i++] = 'F';
2321 if (k->is_instance_klass()) {
2322 InstanceKlass* ik = InstanceKlass::cast(k);
2323 if (ik->has_final_method()) buf[i++] = 'f';
2324 if (ik->is_rewritten()) buf[i++] = 'W';
2325 if (ik->is_contended()) buf[i++] = 'C';
2326 if (ik->has_been_redefined()) buf[i++] = 'R';
2327 if (ik->in_aot_cache()) buf[i++] = 'S';
2328 }
2329 buf[i++] = '\0';
2330 _st->print("%-7s ", buf);
2331 // klass name
2332 _st->print("%-5s ", k->external_name());
2333 // end
2334 _st->cr();
2335 if (_verbose) {
2336 k->print_on(_st);
2337 }
2338 }
2339
2340 /* jni_id_for for jfieldIds only */
2341 JNIid* InstanceKlass::jni_id_for(int offset) {
2342 MutexLocker ml(JfieldIdCreation_lock);
2343 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2344 if (probe == nullptr) {
2345 // Allocate new static field identifier
2346 probe = new JNIid(this, offset, jni_ids());
2347 set_jni_ids(probe);
2348 }
2349 return probe;
2350 }
2351
2352 u2 InstanceKlass::enclosing_method_data(int offset) const {
2353 const Array<jushort>* const inner_class_list = inner_classes();
2354 if (inner_class_list == nullptr) {
2355 return 0;
2356 }
2357 const int length = inner_class_list->length();
2358 if (length % inner_class_next_offset == 0) {
2359 return 0;
2360 }
2361 const int index = length - enclosing_method_attribute_size;
2362 assert(offset < enclosing_method_attribute_size, "invalid offset");
2363 return inner_class_list->at(index + offset);
2364 }
2365
2366 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2367 u2 method_index) {
2368 Array<jushort>* inner_class_list = inner_classes();
2369 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2370 int length = inner_class_list->length();
2371 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2372 int index = length - enclosing_method_attribute_size;
2373 inner_class_list->at_put(
2374 index + enclosing_method_class_index_offset, class_index);
2375 inner_class_list->at_put(
2376 index + enclosing_method_method_index_offset, method_index);
2377 }
2378 }
2379
2380 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2381 if (method->is_old() && !method->is_obsolete()) {
2382 // If the method passed in is old (but not obsolete), use the current version.
2383 method = method_with_idnum((int)idnum);
2384 assert(method != nullptr, "old and but not obsolete, so should exist");
2385 }
2386 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2387 AtomicAccess::release_store(&jmeths[idnum + 1], new_id);
2388 return new_id;
2389 }
2390
2391 // Allocate the jmethodID cache.
2392 static jmethodID* create_jmethod_id_cache(size_t size) {
2393 jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2394 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2395 // cache size is stored in element[0], other elements offset by one
2396 jmeths[0] = (jmethodID)size;
2397 return jmeths;
2398 }
2399
2400 // When reading outside a lock, use this.
2401 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2402 return AtomicAccess::load_acquire(&_methods_jmethod_ids);
2403 }
2404
2405 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2406 AtomicAccess::release_store(&_methods_jmethod_ids, jmeths);
2407 }
2408
2409 // Lookup or create a jmethodID.
2410 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2411 int idnum = method->method_idnum();
2412 jmethodID* jmeths = methods_jmethod_ids_acquire();
2413
2414 // We use a double-check locking idiom here because this cache is
2415 // performance sensitive. In the normal system, this cache only
2416 // transitions from null to non-null which is safe because we use
2417 // release_set_methods_jmethod_ids() to advertise the new cache.
2418 // A partially constructed cache should never be seen by a racing
2419 // thread. We also use release_store() to save a new jmethodID
2420 // in the cache so a partially constructed jmethodID should never be
2421 // seen either. Cache reads of existing jmethodIDs proceed without a
2422 // lock, but cache writes of a new jmethodID requires uniqueness and
2423 // creation of the cache itself requires no leaks so a lock is
2424 // acquired in those two cases.
2425 //
2426 // If the RedefineClasses() API has been used, then this cache grows
2427 // in the redefinition safepoint.
2428
2429 if (jmeths == nullptr) {
2430 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2431 jmeths = _methods_jmethod_ids;
2432 // Still null?
2433 if (jmeths == nullptr) {
2434 size_t size = idnum_allocated_count();
2435 assert(size > (size_t)idnum, "should already have space");
2436 jmeths = create_jmethod_id_cache(size);
2437 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2438
2439 // publish jmeths
2440 release_set_methods_jmethod_ids(jmeths);
2441 return new_id;
2442 }
2443 }
2444
2445 jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2446 if (id == nullptr) {
2447 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2448 id = jmeths[idnum + 1];
2449 // Still null?
2450 if (id == nullptr) {
2451 return update_jmethod_id(jmeths, method, idnum);
2452 }
2453 }
2454 return id;
2455 }
2456
2457 void InstanceKlass::update_methods_jmethod_cache() {
2458 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2459 jmethodID* cache = _methods_jmethod_ids;
2460 if (cache != nullptr) {
2461 size_t size = idnum_allocated_count();
2462 size_t old_size = (size_t)cache[0];
2463 if (old_size < size + 1) {
2464 // Allocate a larger one and copy entries to the new one.
2465 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2466 jmethodID* new_cache = create_jmethod_id_cache(size);
2467
2468 for (int i = 1; i <= (int)old_size; i++) {
2469 new_cache[i] = cache[i];
2470 }
2471 _methods_jmethod_ids = new_cache;
2472 FREE_C_HEAP_ARRAY(jmethodID, cache);
2473 }
2474 }
2475 }
2476
2477 // Make a jmethodID for all methods in this class. This makes getting all method
2478 // 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::make_methods_jmethod_ids() {
2482 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2483 jmethodID* jmeths = _methods_jmethod_ids;
2484 if (jmeths == nullptr) {
2485 jmeths = create_jmethod_id_cache(idnum_allocated_count());
2486 release_set_methods_jmethod_ids(jmeths);
2487 }
2488
2489 int length = methods()->length();
2490 for (int index = 0; index < length; index++) {
2491 Method* m = methods()->at(index);
2492 int idnum = m->method_idnum();
2493 assert(!m->is_old(), "should not have old methods or I'm confused");
2494 jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2495 if (!m->is_overpass() && // skip overpasses
2496 id == nullptr) {
2497 id = Method::make_jmethod_id(class_loader_data(), m);
2498 AtomicAccess::release_store(&jmeths[idnum + 1], id);
2499 }
2500 }
2501 }
2502
2503 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2504 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2505 int idnum = method->method_idnum();
2506 jmethodID* jmeths = methods_jmethod_ids_acquire();
2507 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2508 }
2509
2510 inline DependencyContext InstanceKlass::dependencies() {
2511 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2512 return dep_context;
2513 }
2514
2515 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2516 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2517 }
2518
2519 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2520 assert_lock_strong(CodeCache_lock);
2521 dependencies().add_dependent_nmethod(nm);
2522 }
2523
2524 void InstanceKlass::clean_dependency_context() {
2525 dependencies().clean_unloading_dependents();
2526 }
2527
2528 #ifndef PRODUCT
2529 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2530 dependencies().print_dependent_nmethods(verbose);
2531 }
2532
2533 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2534 return dependencies().is_dependent_nmethod(nm);
2535 }
2536 #endif //PRODUCT
2537
2538 void InstanceKlass::clean_weak_instanceklass_links() {
2539 clean_implementors_list();
2540 clean_method_data();
2541 }
2542
2543 void InstanceKlass::clean_implementors_list() {
2544 assert(is_loader_alive(), "this klass should be live");
2545 if (is_interface()) {
2546 assert (ClassUnloading, "only called for ClassUnloading");
2547 for (;;) {
2548 // Use load_acquire due to competing with inserts
2549 InstanceKlass* volatile* iklass = adr_implementor();
2550 assert(iklass != nullptr, "Klass must not be null");
2551 InstanceKlass* impl = AtomicAccess::load_acquire(iklass);
2552 if (impl != nullptr && !impl->is_loader_alive()) {
2553 // null this field, might be an unloaded instance klass or null
2554 if (AtomicAccess::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2555 // Successfully unlinking implementor.
2556 if (log_is_enabled(Trace, class, unload)) {
2557 ResourceMark rm;
2558 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2559 }
2560 return;
2561 }
2562 } else {
2563 return;
2564 }
2565 }
2566 }
2567 }
2568
2569 void InstanceKlass::clean_method_data() {
2570 for (int m = 0; m < methods()->length(); m++) {
2571 MethodData* mdo = methods()->at(m)->method_data();
2572 if (mdo != nullptr) {
2573 mdo->clean_method_data(/*always_clean*/false);
2574 }
2575 }
2576 }
2577
2578 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2579 Klass::metaspace_pointers_do(it);
2580
2581 if (log_is_enabled(Trace, aot)) {
2582 ResourceMark rm;
2583 log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2584 }
2585
2586 it->push(&_annotations);
2587 it->push((Klass**)&_array_klasses);
2588 if (!is_rewritten()) {
2589 it->push(&_constants, MetaspaceClosure::_writable);
2590 } else {
2591 it->push(&_constants);
2592 }
2593 it->push(&_inner_classes);
2594 #if INCLUDE_JVMTI
2595 it->push(&_previous_versions);
2596 #endif
2597 #if INCLUDE_CDS
2598 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2599 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2600 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2601 // The length check on the _methods is necessary because classes which don't have any
2602 // methods share the Universe::_the_empty_method_array which is in the RO region.
2603 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2604 // To handle jsr bytecode, new Method* maybe stored into _methods
2605 it->push(&_methods, MetaspaceClosure::_writable);
2606 } else {
2607 #endif
2608 it->push(&_methods);
2609 #if INCLUDE_CDS
2610 }
2611 #endif
2612 it->push(&_default_methods);
2613 it->push(&_local_interfaces);
2614 it->push(&_transitive_interfaces);
2615 it->push(&_method_ordering);
2616 if (!is_rewritten()) {
2617 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2618 } else {
2619 it->push(&_default_vtable_indices);
2620 }
2621
2622 it->push(&_fieldinfo_stream);
2623 it->push(&_fieldinfo_search_table);
2624 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2625 it->push(&_fields_status, MetaspaceClosure::_writable);
2626
2627 if (itable_length() > 0) {
2628 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2629 int method_table_offset_in_words = ioe->offset()/wordSize;
2630 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2631
2632 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2633 / itableOffsetEntry::size();
2634
2635 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2636 if (ioe->interface_klass() != nullptr) {
2637 it->push(ioe->interface_klass_addr());
2638 itableMethodEntry* ime = ioe->first_method_entry(this);
2639 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2640 for (int index = 0; index < n; index ++) {
2641 it->push(ime[index].method_addr());
2642 }
2643 }
2644 }
2645 }
2646
2647 it->push(&_nest_host);
2648 it->push(&_nest_members);
2649 it->push(&_permitted_subclasses);
2650 it->push(&_record_components);
2651 }
2652
2653 #if INCLUDE_CDS
2654 void InstanceKlass::remove_unshareable_info() {
2655
2656 if (is_linked()) {
2657 assert(can_be_verified_at_dumptime(), "must be");
2658 // Remember this so we can avoid walking the hierarchy at runtime.
2659 set_verified_at_dump_time();
2660 }
2661
2662 _misc_flags.set_has_init_deps_processed(false);
2663
2664 Klass::remove_unshareable_info();
2665
2666 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2667 // Classes are attempted to link during dumping and may fail,
2668 // but these classes are still in the dictionary and class list in CLD.
2669 // If the class has failed verification, there is nothing else to remove.
2670 return;
2671 }
2672
2673 // Reset to the 'allocated' state to prevent any premature accessing to
2674 // a shared class at runtime while the class is still being loaded and
2675 // restored. A class' init_state is set to 'loaded' at runtime when it's
2676 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2677 _init_state = allocated;
2678
2679 { // Otherwise this needs to take out the Compile_lock.
2680 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2681 init_implementor();
2682 }
2683
2684 // Call remove_unshareable_info() on other objects that belong to this class, except
2685 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2686 // ArchiveBuilder::make_klasses_shareable(),
2687
2688 for (int i = 0; i < methods()->length(); i++) {
2689 Method* m = methods()->at(i);
2690 m->remove_unshareable_info();
2691 }
2692
2693 // do array classes also.
2694 if (array_klasses() != nullptr) {
2695 array_klasses()->remove_unshareable_info();
2696 }
2697
2698 // These are not allocated from metaspace. They are safe to set to null.
2699 _source_debug_extension = nullptr;
2700 _dep_context = nullptr;
2701 _osr_nmethods_head = nullptr;
2702 #if INCLUDE_JVMTI
2703 _breakpoints = nullptr;
2704 _previous_versions = nullptr;
2705 _cached_class_file = nullptr;
2706 _jvmti_cached_class_field_map = nullptr;
2707 #endif
2708
2709 _init_thread = nullptr;
2710 _methods_jmethod_ids = nullptr;
2711 _jni_ids = nullptr;
2712 _oop_map_cache = nullptr;
2713 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2714 // keep _nest_host
2715 } else {
2716 // clear _nest_host to ensure re-load at runtime
2717 _nest_host = nullptr;
2718 }
2719 init_shared_package_entry();
2720 _dep_context_last_cleaned = 0;
2721 DEBUG_ONLY(_shared_class_load_count = 0);
2722
2723 remove_unshareable_flags();
2724
2725 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2726 }
2727
2728 void InstanceKlass::remove_unshareable_flags() {
2729 // clear all the flags/stats that shouldn't be in the archived version
2730 assert(!is_scratch_class(), "must be");
2731 assert(!has_been_redefined(), "must be");
2732 #if INCLUDE_JVMTI
2733 set_is_being_redefined(false);
2734 #endif
2735 set_has_resolved_methods(false);
2736 }
2737
2738 void InstanceKlass::remove_java_mirror() {
2739 Klass::remove_java_mirror();
2740
2741 // do array classes also.
2742 if (array_klasses() != nullptr) {
2743 array_klasses()->remove_java_mirror();
2744 }
2745 }
2746
2747 void InstanceKlass::init_shared_package_entry() {
2748 assert(CDSConfig::is_dumping_archive(), "must be");
2749 #if !INCLUDE_CDS_JAVA_HEAP
2750 _package_entry = nullptr;
2751 #else
2752 if (CDSConfig::is_dumping_full_module_graph()) {
2753 if (defined_by_other_loaders()) {
2754 _package_entry = nullptr;
2755 } else {
2756 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2757 }
2758 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2759 CDSConfig::is_using_full_module_graph() &&
2760 AOTMetaspace::in_aot_cache(_package_entry)) {
2761 // _package_entry is an archived package in the base archive. Leave it as is.
2762 } else {
2763 _package_entry = nullptr;
2764 }
2765 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2766 #endif
2767 }
2768
2769 void InstanceKlass::compute_has_loops_flag_for_methods() {
2770 Array<Method*>* methods = this->methods();
2771 for (int index = 0; index < methods->length(); ++index) {
2772 Method* m = methods->at(index);
2773 if (!m->is_overpass()) { // work around JDK-8305771
2774 m->compute_has_loops_flag();
2775 }
2776 }
2777 }
2778
2779 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2780 PackageEntry* pkg_entry, TRAPS) {
2781 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2782 // before the InstanceKlass is added to the SystemDictionary. Make
2783 // sure the current state is <loaded.
2784 assert(!is_loaded(), "invalid init state");
2785 assert(!shared_loading_failed(), "Must not try to load failed class again");
2786 set_package(loader_data, pkg_entry, CHECK);
2787 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2788
2789 Array<Method*>* methods = this->methods();
2790 int num_methods = methods->length();
2791 for (int index = 0; index < num_methods; ++index) {
2792 methods->at(index)->restore_unshareable_info(CHECK);
2793 }
2794 #if INCLUDE_JVMTI
2795 if (JvmtiExport::has_redefined_a_class()) {
2796 // Reinitialize vtable because RedefineClasses may have changed some
2797 // entries in this vtable for super classes so the CDS vtable might
2798 // point to old or obsolete entries. RedefineClasses doesn't fix up
2799 // vtables in the shared system dictionary, only the main one.
2800 // It also redefines the itable too so fix that too.
2801 // First fix any default methods that point to a super class that may
2802 // have been redefined.
2803 bool trace_name_printed = false;
2804 adjust_default_methods(&trace_name_printed);
2805 if (verified_at_dump_time()) {
2806 // Initialize vtable and itable for classes which can be verified at dump time.
2807 // Unlinked classes such as old classes with major version < 50 cannot be verified
2808 // at dump time.
2809 vtable().initialize_vtable();
2810 itable().initialize_itable();
2811 }
2812 }
2813 #endif // INCLUDE_JVMTI
2814
2815 // restore constant pool resolved references
2816 constants()->restore_unshareable_info(CHECK);
2817
2818 if (array_klasses() != nullptr) {
2819 // To get a consistent list of classes we need MultiArray_lock to ensure
2820 // array classes aren't observed while they are being restored.
2821 RecursiveLocker rl(MultiArray_lock, THREAD);
2822 assert(this == array_klasses()->bottom_klass(), "sanity");
2823 // Array classes have null protection domain.
2824 // --> see ArrayKlass::complete_create_array_klass()
2825 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2826 }
2827
2828 // Initialize @ValueBased class annotation if not already set in the archived klass.
2829 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2830 set_is_value_based();
2831 }
2832
2833 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2834 }
2835
2836 bool InstanceKlass::can_be_verified_at_dumptime() const {
2837 if (AOTMetaspace::in_aot_cache(this)) {
2838 // This is a class that was dumped into the base archive, so we know
2839 // it was verified at dump time.
2840 return true;
2841 }
2842
2843 if (CDSConfig::is_preserving_verification_constraints()) {
2844 return true;
2845 }
2846
2847 if (CDSConfig::is_old_class_for_verifier(this)) {
2848 // The old verifier does not save verification constraints, so at run time
2849 // SystemDictionaryShared::check_verification_constraints() will not work for this class.
2850 return false;
2851 }
2852 if (super() != nullptr && !super()->can_be_verified_at_dumptime()) {
2853 return false;
2854 }
2855 Array<InstanceKlass*>* interfaces = local_interfaces();
2856 int len = interfaces->length();
2857 for (int i = 0; i < len; i++) {
2858 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2859 return false;
2860 }
2861 }
2862 return true;
2863 }
2864
2865 #endif // INCLUDE_CDS
2866
2867 #if INCLUDE_JVMTI
2868 static void clear_all_breakpoints(Method* m) {
2869 m->clear_all_breakpoints();
2870 }
2871 #endif
2872
2873 void InstanceKlass::unload_class(InstanceKlass* ik) {
2874
2875 if (ik->is_scratch_class()) {
2876 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2877 return;
2878 }
2879 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2880
2881 // Release dependencies.
2882 ik->dependencies().remove_all_dependents();
2883
2884 // notify the debugger
2885 if (JvmtiExport::should_post_class_unload()) {
2886 JvmtiExport::post_class_unload(ik);
2887 }
2888
2889 // notify ClassLoadingService of class unload
2890 ClassLoadingService::notify_class_unloaded(ik);
2891
2892 SystemDictionaryShared::handle_class_unloading(ik);
2893
2894 if (log_is_enabled(Info, class, unload)) {
2895 ResourceMark rm;
2896 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2897 }
2898
2899 Events::log_class_unloading(Thread::current(), ik);
2900
2901 #if INCLUDE_JFR
2902 assert(ik != nullptr, "invariant");
2903 EventClassUnload event;
2904 event.set_unloadedClass(ik);
2905 event.set_definingClassLoader(ik->class_loader_data());
2906 event.commit();
2907 #endif
2908 }
2909
2910 static void method_release_C_heap_structures(Method* m) {
2911 m->release_C_heap_structures();
2912 }
2913
2914 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2915 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2916 // Clean up C heap
2917 Klass::release_C_heap_structures();
2918
2919 // Deallocate and call destructors for MDO mutexes
2920 if (release_sub_metadata) {
2921 methods_do(method_release_C_heap_structures);
2922 }
2923
2924 // Deallocate oop map cache
2925 if (_oop_map_cache != nullptr) {
2926 delete _oop_map_cache;
2927 _oop_map_cache = nullptr;
2928 }
2929
2930 // Deallocate JNI identifiers for jfieldIDs
2931 JNIid::deallocate(jni_ids());
2932 set_jni_ids(nullptr);
2933
2934 jmethodID* jmeths = _methods_jmethod_ids;
2935 if (jmeths != nullptr) {
2936 release_set_methods_jmethod_ids(nullptr);
2937 FreeHeap(jmeths);
2938 }
2939
2940 assert(_dep_context == nullptr,
2941 "dependencies should already be cleaned");
2942
2943 #if INCLUDE_JVMTI
2944 // Deallocate breakpoint records
2945 if (breakpoints() != nullptr) {
2946 methods_do(clear_all_breakpoints);
2947 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2948 }
2949
2950 // deallocate the cached class file
2951 if (_cached_class_file != nullptr) {
2952 os::free(_cached_class_file);
2953 _cached_class_file = nullptr;
2954 }
2955 #endif
2956
2957 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2958
2959 if (release_sub_metadata) {
2960 constants()->release_C_heap_structures();
2961 }
2962 }
2963
2964 // The constant pool is on stack if any of the methods are executing or
2965 // referenced by handles.
2966 bool InstanceKlass::on_stack() const {
2967 return _constants->on_stack();
2968 }
2969
2970 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2971 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2972 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2973
2974 // minor and major version numbers of class file
2975 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2976 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2977 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2978 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2979
2980 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
2981 for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2982 if (ik->constants()->version() == version) {
2983 return ik;
2984 }
2985 }
2986 return nullptr;
2987 }
2988
2989 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2990 if (array == nullptr) {
2991 _source_debug_extension = nullptr;
2992 } else {
2993 // Adding one to the attribute length in order to store a null terminator
2994 // character could cause an overflow because the attribute length is
2995 // already coded with an u4 in the classfile, but in practice, it's
2996 // unlikely to happen.
2997 assert((length+1) > length, "Overflow checking");
2998 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2999 for (int i = 0; i < length; i++) {
3000 sde[i] = array[i];
3001 }
3002 sde[length] = '\0';
3003 _source_debug_extension = sde;
3004 }
3005 }
3006
3007 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3008 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3009 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3010
3011 const char* InstanceKlass::signature_name() const {
3012
3013 // Get the internal name as a c string
3014 const char* src = (const char*) (name()->as_C_string());
3015 const int src_length = (int)strlen(src);
3016
3017 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3018
3019 // Add L as type indicator
3020 int dest_index = 0;
3021 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3022
3023 // Add the actual class name
3024 for (int src_index = 0; src_index < src_length; ) {
3025 dest[dest_index++] = src[src_index++];
3026 }
3027
3028 if (is_hidden()) { // Replace the last '+' with a '.'.
3029 for (int index = (int)src_length; index > 0; index--) {
3030 if (dest[index] == '+') {
3031 dest[index] = JVM_SIGNATURE_DOT;
3032 break;
3033 }
3034 }
3035 }
3036
3037 // Add the semicolon and the null
3038 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3039 dest[dest_index] = '\0';
3040 return dest;
3041 }
3042
3043 ModuleEntry* InstanceKlass::module() const {
3044 if (is_hidden() &&
3045 in_unnamed_package() &&
3046 class_loader_data()->has_class_mirror_holder()) {
3047 // For a non-strong hidden class defined to an unnamed package,
3048 // its (class held) CLD will not have an unnamed module created for it.
3049 // Two choices to find the correct ModuleEntry:
3050 // 1. If hidden class is within a nest, use nest host's module
3051 // 2. Find the unnamed module off from the class loader
3052 // For now option #2 is used since a nest host is not set until
3053 // after the instance class is created in jvm_lookup_define_class().
3054 if (class_loader_data()->is_boot_class_loader_data()) {
3055 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3056 } else {
3057 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3058 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3059 return java_lang_Module::module_entry(module);
3060 }
3061 }
3062
3063 // Class is in a named package
3064 if (!in_unnamed_package()) {
3065 return _package_entry->module();
3066 }
3067
3068 // Class is in an unnamed package, return its loader's unnamed module
3069 return class_loader_data()->unnamed_module();
3070 }
3071
3072 bool InstanceKlass::in_javabase_module() const {
3073 return module()->name() == vmSymbols::java_base();
3074 }
3075
3076 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3077
3078 // ensure java/ packages only loaded by boot or platform builtin loaders
3079 // not needed for shared class since CDS does not archive prohibited classes.
3080 if (!in_aot_cache()) {
3081 check_prohibited_package(name(), loader_data, CHECK);
3082 }
3083
3084 if (in_aot_cache() && _package_entry != nullptr) {
3085 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3086 // we can use the saved package
3087 assert(AOTMetaspace::in_aot_cache(_package_entry), "must be");
3088 return;
3089 } else {
3090 _package_entry = nullptr;
3091 }
3092 }
3093
3094 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3095 // it returns, so we need to decrement it when the current function exits.
3096 TempNewSymbol from_class_name =
3097 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3098
3099 Symbol* pkg_name;
3100 if (pkg_entry != nullptr) {
3101 pkg_name = pkg_entry->name();
3102 } else {
3103 pkg_name = from_class_name;
3104 }
3105
3106 if (pkg_name != nullptr && loader_data != nullptr) {
3107
3108 // Find in class loader's package entry table.
3109 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3110
3111 // If the package name is not found in the loader's package
3112 // entry table, it is an indication that the package has not
3113 // been defined. Consider it defined within the unnamed module.
3114 if (_package_entry == nullptr) {
3115
3116 if (!ModuleEntryTable::javabase_defined()) {
3117 // Before java.base is defined during bootstrapping, define all packages in
3118 // the java.base module. If a non-java.base package is erroneously placed
3119 // in the java.base module it will be caught later when java.base
3120 // is defined by ModuleEntryTable::verify_javabase_packages check.
3121 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3122 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3123 } else {
3124 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3125 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3126 }
3127
3128 // A package should have been successfully created
3129 DEBUG_ONLY(ResourceMark rm(THREAD));
3130 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3131 name()->as_C_string(), loader_data->loader_name_and_id());
3132 }
3133
3134 if (log_is_enabled(Debug, module)) {
3135 ResourceMark rm(THREAD);
3136 ModuleEntry* m = _package_entry->module();
3137 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3138 external_name(),
3139 pkg_name->as_C_string(),
3140 loader_data->loader_name_and_id(),
3141 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3142 }
3143 } else {
3144 ResourceMark rm(THREAD);
3145 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3146 external_name(),
3147 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3148 UNNAMED_MODULE);
3149 }
3150 }
3151
3152 // Function set_classpath_index ensures that for a non-null _package_entry
3153 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3154 // It then sets the classpath_index in the package entry record.
3155 //
3156 // The classpath_index field is used to find the entry on the boot loader class
3157 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3158 // in an unnamed module. It is also used to indicate (for all packages whose
3159 // classes are loaded by the boot loader) that at least one of the package's
3160 // classes has been loaded.
3161 void InstanceKlass::set_classpath_index(s2 path_index) {
3162 if (_package_entry != nullptr) {
3163 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3164 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3165 assert(path_index != -1, "Unexpected classpath_index");
3166 _package_entry->set_classpath_index(path_index);
3167 }
3168 }
3169
3170 // different versions of is_same_class_package
3171
3172 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3173 oop classloader1 = this->class_loader();
3174 PackageEntry* classpkg1 = this->package();
3175 if (class2->is_objArray_klass()) {
3176 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3177 }
3178
3179 oop classloader2;
3180 PackageEntry* classpkg2;
3181 if (class2->is_instance_klass()) {
3182 classloader2 = class2->class_loader();
3183 classpkg2 = class2->package();
3184 } else {
3185 assert(class2->is_typeArray_klass(), "should be type array");
3186 classloader2 = nullptr;
3187 classpkg2 = nullptr;
3188 }
3189
3190 // Same package is determined by comparing class loader
3191 // and package entries. Both must be the same. This rule
3192 // applies even to classes that are defined in the unnamed
3193 // package, they still must have the same class loader.
3194 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3195 return true;
3196 }
3197
3198 return false;
3199 }
3200
3201 // return true if this class and other_class are in the same package. Classloader
3202 // and classname information is enough to determine a class's package
3203 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3204 const Symbol* other_class_name) const {
3205 if (class_loader() != other_class_loader) {
3206 return false;
3207 }
3208 if (name()->fast_compare(other_class_name) == 0) {
3209 return true;
3210 }
3211
3212 {
3213 ResourceMark rm;
3214
3215 bool bad_class_name = false;
3216 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3217 if (bad_class_name) {
3218 return false;
3219 }
3220 // Check that package_from_class_name() returns null, not "", if there is no package.
3221 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3222
3223 const Symbol* const this_package_name =
3224 this->package() != nullptr ? this->package()->name() : nullptr;
3225
3226 if (this_package_name == nullptr || other_pkg == nullptr) {
3227 // One of the two doesn't have a package. Only return true if the other
3228 // one also doesn't have a package.
3229 return this_package_name == other_pkg;
3230 }
3231
3232 // Check if package is identical
3233 return this_package_name->fast_compare(other_pkg) == 0;
3234 }
3235 }
3236
3237 static bool is_prohibited_package_slow(Symbol* class_name) {
3238 // Caller has ResourceMark
3239 int length;
3240 jchar* unicode = class_name->as_unicode(length);
3241 return (length >= 5 &&
3242 unicode[0] == 'j' &&
3243 unicode[1] == 'a' &&
3244 unicode[2] == 'v' &&
3245 unicode[3] == 'a' &&
3246 unicode[4] == '/');
3247 }
3248
3249 // Only boot and platform class loaders can define classes in "java/" packages.
3250 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3251 ClassLoaderData* loader_data,
3252 TRAPS) {
3253 if (!loader_data->is_boot_class_loader_data() &&
3254 !loader_data->is_platform_class_loader_data() &&
3255 class_name != nullptr && class_name->utf8_length() >= 5) {
3256 ResourceMark rm(THREAD);
3257 bool prohibited;
3258 const u1* base = class_name->base();
3259 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3260 prohibited = is_prohibited_package_slow(class_name);
3261 } else {
3262 char* name = class_name->as_C_string();
3263 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3264 }
3265 if (prohibited) {
3266 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3267 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3268 char* name = pkg_name->as_C_string();
3269 const char* class_loader_name = loader_data->loader_name_and_id();
3270 StringUtils::replace_no_expand(name, "/", ".");
3271 const char* msg_text1 = "Class loader (instance of): ";
3272 const char* msg_text2 = " tried to load prohibited package name: ";
3273 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3274 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3275 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3276 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3277 }
3278 }
3279 return;
3280 }
3281
3282 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3283 constantPoolHandle i_cp(THREAD, constants());
3284 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3285 int ioff = iter.inner_class_info_index();
3286 if (ioff != 0) {
3287 // Check to see if the name matches the class we're looking for
3288 // before attempting to find the class.
3289 if (i_cp->klass_name_at_matches(this, ioff)) {
3290 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3291 if (this == inner_klass) {
3292 *ooff = iter.outer_class_info_index();
3293 *noff = iter.inner_name_index();
3294 return true;
3295 }
3296 }
3297 }
3298 }
3299 return false;
3300 }
3301
3302 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3303 InstanceKlass* outer_klass = nullptr;
3304 *inner_is_member = false;
3305 int ooff = 0, noff = 0;
3306 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3307 if (has_inner_classes_attr) {
3308 constantPoolHandle i_cp(THREAD, constants());
3309 if (ooff != 0) {
3310 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3311 if (!ok->is_instance_klass()) {
3312 // If the outer class is not an instance klass then it cannot have
3313 // declared any inner classes.
3314 ResourceMark rm(THREAD);
3315 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3316 Exceptions::fthrow(
3317 THREAD_AND_LOCATION,
3318 vmSymbols::java_lang_IncompatibleClassChangeError(),
3319 "%s and %s disagree on InnerClasses attribute",
3320 ok->external_name(),
3321 external_name());
3322 return nullptr;
3323 }
3324 outer_klass = InstanceKlass::cast(ok);
3325 *inner_is_member = true;
3326 }
3327 if (nullptr == outer_klass) {
3328 // It may be a local class; try for that.
3329 int encl_method_class_idx = enclosing_method_class_index();
3330 if (encl_method_class_idx != 0) {
3331 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3332 outer_klass = InstanceKlass::cast(ok);
3333 *inner_is_member = false;
3334 }
3335 }
3336 }
3337
3338 // If no inner class attribute found for this class.
3339 if (nullptr == outer_klass) return nullptr;
3340
3341 // Throws an exception if outer klass has not declared k as an inner klass
3342 // We need evidence that each klass knows about the other, or else
3343 // the system could allow a spoof of an inner class to gain access rights.
3344 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3345 return outer_klass;
3346 }
3347
3348 u2 InstanceKlass::compute_modifier_flags() const {
3349 u2 access = access_flags().as_unsigned_short();
3350
3351 // But check if it happens to be member class.
3352 InnerClassesIterator iter(this);
3353 for (; !iter.done(); iter.next()) {
3354 int ioff = iter.inner_class_info_index();
3355 // Inner class attribute can be zero, skip it.
3356 // Strange but true: JVM spec. allows null inner class refs.
3357 if (ioff == 0) continue;
3358
3359 // only look at classes that are already loaded
3360 // since we are looking for the flags for our self.
3361 Symbol* inner_name = constants()->klass_name_at(ioff);
3362 if (name() == inner_name) {
3363 // This is really a member class.
3364 access = iter.inner_access_flags();
3365 break;
3366 }
3367 }
3368 // Remember to strip ACC_SUPER bit
3369 return (access & (~JVM_ACC_SUPER));
3370 }
3371
3372 jint InstanceKlass::jvmti_class_status() const {
3373 jint result = 0;
3374
3375 if (is_linked()) {
3376 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3377 }
3378
3379 if (is_initialized()) {
3380 assert(is_linked(), "Class status is not consistent");
3381 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3382 }
3383 if (is_in_error_state()) {
3384 result |= JVMTI_CLASS_STATUS_ERROR;
3385 }
3386 return result;
3387 }
3388
3389 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3390 bool implements_interface; // initialized by method_at_itable_or_null
3391 Method* m = method_at_itable_or_null(holder, index,
3392 implements_interface); // out parameter
3393 if (m != nullptr) {
3394 assert(implements_interface, "sanity");
3395 return m;
3396 } else if (implements_interface) {
3397 // Throw AbstractMethodError since corresponding itable slot is empty.
3398 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3399 } else {
3400 // If the interface isn't implemented by the receiver class,
3401 // the VM should throw IncompatibleClassChangeError.
3402 ResourceMark rm(THREAD);
3403 stringStream ss;
3404 bool same_module = (module() == holder->module());
3405 ss.print("Receiver class %s does not implement "
3406 "the interface %s defining the method to be called "
3407 "(%s%s%s)",
3408 external_name(), holder->external_name(),
3409 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3410 (same_module) ? "" : "; ",
3411 (same_module) ? "" : holder->class_in_module_of_loader());
3412 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3413 }
3414 }
3415
3416 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3417 klassItable itable(this);
3418 for (int i = 0; i < itable.size_offset_table(); i++) {
3419 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3420 if (offset_entry->interface_klass() == holder) {
3421 implements_interface = true;
3422 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3423 Method* m = ime[index].method();
3424 return m;
3425 }
3426 }
3427 implements_interface = false;
3428 return nullptr; // offset entry not found
3429 }
3430
3431 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3432 assert(is_linked(), "required");
3433 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3434 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3435
3436 int vtable_index = Method::invalid_vtable_index;
3437 Symbol* name = intf_method->name();
3438 Symbol* signature = intf_method->signature();
3439
3440 // First check in default method array
3441 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3442 int index = find_method_index(default_methods(),
3443 name, signature,
3444 Klass::OverpassLookupMode::find,
3445 Klass::StaticLookupMode::find,
3446 Klass::PrivateLookupMode::find);
3447 if (index >= 0) {
3448 vtable_index = default_vtable_indices()->at(index);
3449 }
3450 }
3451 if (vtable_index == Method::invalid_vtable_index) {
3452 // get vtable_index for miranda methods
3453 klassVtable vt = vtable();
3454 vtable_index = vt.index_of_miranda(name, signature);
3455 }
3456 return vtable_index;
3457 }
3458
3459 #if INCLUDE_JVMTI
3460 // update default_methods for redefineclasses for methods that are
3461 // not yet in the vtable due to concurrent subclass define and superinterface
3462 // redefinition
3463 // Note: those in the vtable, should have been updated via adjust_method_entries
3464 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3465 // search the default_methods for uses of either obsolete or EMCP methods
3466 if (default_methods() != nullptr) {
3467 for (int index = 0; index < default_methods()->length(); index ++) {
3468 Method* old_method = default_methods()->at(index);
3469 if (old_method == nullptr || !old_method->is_old()) {
3470 continue; // skip uninteresting entries
3471 }
3472 assert(!old_method->is_deleted(), "default methods may not be deleted");
3473 Method* new_method = old_method->get_new_method();
3474 default_methods()->at_put(index, new_method);
3475
3476 if (log_is_enabled(Info, redefine, class, update)) {
3477 ResourceMark rm;
3478 if (!(*trace_name_printed)) {
3479 log_info(redefine, class, update)
3480 ("adjust: klassname=%s default methods from name=%s",
3481 external_name(), old_method->method_holder()->external_name());
3482 *trace_name_printed = true;
3483 }
3484 log_debug(redefine, class, update, vtables)
3485 ("default method update: %s(%s) ",
3486 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3487 }
3488 }
3489 }
3490 }
3491 #endif // INCLUDE_JVMTI
3492
3493 // On-stack replacement stuff
3494 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3495 assert_lock_strong(NMethodState_lock);
3496 #ifndef PRODUCT
3497 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3498 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3499 "redundant OSR recompilation detected. memory leak in CodeCache!");
3500 #endif
3501 // only one compilation can be active
3502 assert(n->is_osr_method(), "wrong kind of nmethod");
3503 n->set_osr_link(osr_nmethods_head());
3504 set_osr_nmethods_head(n);
3505 // Raise the highest osr level if necessary
3506 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3507
3508 // Get rid of the osr methods for the same bci that have lower levels.
3509 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3510 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3511 if (inv != nullptr && inv->is_in_use()) {
3512 inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3513 }
3514 }
3515 }
3516
3517 // Remove osr nmethod from the list. Return true if found and removed.
3518 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3519 // This is a short non-blocking critical region, so the no safepoint check is ok.
3520 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3521 assert(n->is_osr_method(), "wrong kind of nmethod");
3522 nmethod* last = nullptr;
3523 nmethod* cur = osr_nmethods_head();
3524 int max_level = CompLevel_none; // Find the max comp level excluding n
3525 Method* m = n->method();
3526 // Search for match
3527 bool found = false;
3528 while(cur != nullptr && cur != n) {
3529 if (m == cur->method()) {
3530 // Find max level before n
3531 max_level = MAX2(max_level, cur->comp_level());
3532 }
3533 last = cur;
3534 cur = cur->osr_link();
3535 }
3536 nmethod* next = nullptr;
3537 if (cur == n) {
3538 found = true;
3539 next = cur->osr_link();
3540 if (last == nullptr) {
3541 // Remove first element
3542 set_osr_nmethods_head(next);
3543 } else {
3544 last->set_osr_link(next);
3545 }
3546 }
3547 n->set_osr_link(nullptr);
3548 cur = next;
3549 while (cur != nullptr) {
3550 // Find max level after n
3551 if (m == cur->method()) {
3552 max_level = MAX2(max_level, cur->comp_level());
3553 }
3554 cur = cur->osr_link();
3555 }
3556 m->set_highest_osr_comp_level(max_level);
3557 return found;
3558 }
3559
3560 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3561 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3562 nmethod* osr = osr_nmethods_head();
3563 int found = 0;
3564 while (osr != nullptr) {
3565 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3566 if (osr->method() == m) {
3567 deopt_scope->mark(osr);
3568 found++;
3569 }
3570 osr = osr->osr_link();
3571 }
3572 return found;
3573 }
3574
3575 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3576 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3577 nmethod* osr = osr_nmethods_head();
3578 nmethod* best = nullptr;
3579 while (osr != nullptr) {
3580 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3581 // There can be a time when a c1 osr method exists but we are waiting
3582 // for a c2 version. When c2 completes its osr nmethod we will trash
3583 // the c1 version and only be able to find the c2 version. However
3584 // while we overflow in the c1 code at back branches we don't want to
3585 // try and switch to the same code as we are already running
3586
3587 if (osr->method() == m &&
3588 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3589 if (match_level) {
3590 if (osr->comp_level() == comp_level) {
3591 // Found a match - return it.
3592 return osr;
3593 }
3594 } else {
3595 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3596 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3597 // Found the best possible - return it.
3598 return osr;
3599 }
3600 best = osr;
3601 }
3602 }
3603 }
3604 osr = osr->osr_link();
3605 }
3606
3607 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3608 if (best != nullptr && best->comp_level() >= comp_level) {
3609 return best;
3610 }
3611 return nullptr;
3612 }
3613
3614 // -----------------------------------------------------------------------------------------------------
3615 // Printing
3616
3617 #define BULLET " - "
3618
3619 static const char* state_names[] = {
3620 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3621 };
3622
3623 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3624 for (int i = 0; i < len; i++) {
3625 intptr_t e = start[i];
3626 st->print("%d : " INTPTR_FORMAT, i, e);
3627 if (MetaspaceObj::is_valid((Metadata*)e)) {
3628 st->print(" ");
3629 ((Metadata*)e)->print_value_on(st);
3630 }
3631 st->cr();
3632 }
3633 }
3634
3635 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3636 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3637 }
3638
3639 const char* InstanceKlass::init_state_name() const {
3640 return state_names[init_state()];
3641 }
3642
3643 void InstanceKlass::print_on(outputStream* st) const {
3644 assert(is_klass(), "must be klass");
3645 Klass::print_on(st);
3646
3647 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3648 st->print(BULLET"klass size: %d", size()); st->cr();
3649 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3650 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3651 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3652 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3653 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3654 st->print(BULLET"sub: ");
3655 Klass* sub = subklass();
3656 int n;
3657 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3658 if (n < MaxSubklassPrintSize) {
3659 sub->print_value_on(st);
3660 st->print(" ");
3661 }
3662 }
3663 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3664 st->cr();
3665
3666 if (is_interface()) {
3667 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3668 if (nof_implementors() == 1) {
3669 st->print_cr(BULLET"implementor: ");
3670 st->print(" ");
3671 implementor()->print_value_on(st);
3672 st->cr();
3673 }
3674 }
3675
3676 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3677 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3678 if (Verbose || WizardMode) {
3679 Array<Method*>* method_array = methods();
3680 for (int i = 0; i < method_array->length(); i++) {
3681 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3682 }
3683 }
3684 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3685 if (default_methods() != nullptr) {
3686 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3687 if (Verbose) {
3688 Array<Method*>* method_array = default_methods();
3689 for (int i = 0; i < method_array->length(); i++) {
3690 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3691 }
3692 }
3693 }
3694 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3695 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3696 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3697
3698 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3699
3700 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3701 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3702
3703 if (secondary_supers() != nullptr) {
3704 if (Verbose) {
3705 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3706 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3707 for (int i = 0; i < _secondary_supers->length(); i++) {
3708 ResourceMark rm; // for external_name()
3709 Klass* secondary_super = _secondary_supers->at(i);
3710 st->print(BULLET"%2d:", i);
3711 if (is_hashed) {
3712 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3713 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3714 st->print(" dist:%02d:", distance);
3715 }
3716 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3717 }
3718 }
3719 }
3720 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3721
3722 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3723 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3724 if (source_debug_extension() != nullptr) {
3725 st->print(BULLET"source debug extension: ");
3726 st->print("%s", source_debug_extension());
3727 st->cr();
3728 }
3729 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3730 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3731 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3732 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3733 {
3734 bool have_pv = false;
3735 // previous versions are linked together through the InstanceKlass
3736 for (InstanceKlass* pv_node = previous_versions();
3737 pv_node != nullptr;
3738 pv_node = pv_node->previous_versions()) {
3739 if (!have_pv)
3740 st->print(BULLET"previous version: ");
3741 have_pv = true;
3742 pv_node->constants()->print_value_on(st);
3743 }
3744 if (have_pv) st->cr();
3745 }
3746
3747 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3748 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3749 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3750 print_on_maybe_null(st, BULLET"record components: ", record_components());
3751 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3752 if (java_mirror() != nullptr) {
3753 st->print(BULLET"java mirror: ");
3754 java_mirror()->print_value_on(st);
3755 st->cr();
3756 } else {
3757 st->print_cr(BULLET"java mirror: null");
3758 }
3759 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3760 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3761 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3762 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3763 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3764
3765 FieldPrinter print_static_field(st);
3766 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3767 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3768 FieldPrinter print_nonstatic_field(st);
3769 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3770 ik->print_nonstatic_fields(&print_nonstatic_field);
3771
3772 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3773 OopMapBlock* map = start_of_nonstatic_oop_maps();
3774 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3775 while (map < end_map) {
3776 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3777 map++;
3778 }
3779 st->cr();
3780
3781 if (fieldinfo_search_table() != nullptr) {
3782 st->print_cr(BULLET"---- field info search table:");
3783 FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
3784 }
3785 }
3786
3787 void InstanceKlass::print_value_on(outputStream* st) const {
3788 assert(is_klass(), "must be klass");
3789 if (Verbose || WizardMode) access_flags().print_on(st);
3790 name()->print_value_on(st);
3791 }
3792
3793 void FieldPrinter::do_field(fieldDescriptor* fd) {
3794 _st->print(BULLET);
3795 if (_obj == nullptr) {
3796 fd->print_on(_st);
3797 _st->cr();
3798 } else {
3799 fd->print_on_for(_st, _obj);
3800 _st->cr();
3801 }
3802 }
3803
3804
3805 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3806 Klass::oop_print_on(obj, st);
3807
3808 if (this == vmClasses::String_klass()) {
3809 typeArrayOop value = java_lang_String::value(obj);
3810 juint length = java_lang_String::length(obj);
3811 if (value != nullptr &&
3812 value->is_typeArray() &&
3813 length <= (juint) value->length()) {
3814 st->print(BULLET"string: ");
3815 java_lang_String::print(obj, st);
3816 st->cr();
3817 }
3818 }
3819
3820 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3821 FieldPrinter print_field(st, obj);
3822 print_nonstatic_fields(&print_field);
3823
3824 if (this == vmClasses::Class_klass()) {
3825 st->print(BULLET"signature: ");
3826 java_lang_Class::print_signature(obj, st);
3827 st->cr();
3828 Klass* real_klass = java_lang_Class::as_Klass(obj);
3829 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3830 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3831 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3832 }
3833 } else if (this == vmClasses::MethodType_klass()) {
3834 st->print(BULLET"signature: ");
3835 java_lang_invoke_MethodType::print_signature(obj, st);
3836 st->cr();
3837 }
3838 }
3839
3840 #ifndef PRODUCT
3841
3842 bool InstanceKlass::verify_itable_index(int i) {
3843 int method_count = klassItable::method_count_for_interface(this);
3844 assert(i >= 0 && i < method_count, "index out of bounds");
3845 return true;
3846 }
3847
3848 #endif //PRODUCT
3849
3850 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3851 st->print("a ");
3852 name()->print_value_on(st);
3853 obj->print_address_on(st);
3854 if (this == vmClasses::String_klass()
3855 && java_lang_String::value(obj) != nullptr) {
3856 ResourceMark rm;
3857 int len = java_lang_String::length(obj);
3858 int plen = (len < 24 ? len : 12);
3859 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3860 st->print(" = \"%s\"", str);
3861 if (len > plen)
3862 st->print("...[%d]", len);
3863 } else if (this == vmClasses::Class_klass()) {
3864 Klass* k = java_lang_Class::as_Klass(obj);
3865 st->print(" = ");
3866 if (k != nullptr) {
3867 k->print_value_on(st);
3868 } else {
3869 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3870 st->print("%s", tname ? tname : "type?");
3871 }
3872 } else if (this == vmClasses::MethodType_klass()) {
3873 st->print(" = ");
3874 java_lang_invoke_MethodType::print_signature(obj, st);
3875 } else if (java_lang_boxing_object::is_instance(obj)) {
3876 st->print(" = ");
3877 java_lang_boxing_object::print(obj, st);
3878 } else if (this == vmClasses::LambdaForm_klass()) {
3879 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3880 if (vmentry != nullptr) {
3881 st->print(" => ");
3882 vmentry->print_value_on(st);
3883 }
3884 } else if (this == vmClasses::MemberName_klass()) {
3885 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3886 if (vmtarget != nullptr) {
3887 st->print(" = ");
3888 vmtarget->print_value_on(st);
3889 } else {
3890 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3891 oop name = java_lang_invoke_MemberName::name(obj);
3892 if (clazz != nullptr) {
3893 clazz->print_value_on(st);
3894 } else {
3895 st->print("null");
3896 }
3897 st->print(".");
3898 if (name != nullptr) {
3899 name->print_value_on(st);
3900 } else {
3901 st->print("null");
3902 }
3903 }
3904 }
3905 }
3906
3907 const char* InstanceKlass::internal_name() const {
3908 return external_name();
3909 }
3910
3911 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3912 const ModuleEntry* module_entry,
3913 const ClassFileStream* cfs) const {
3914
3915 if (ClassListWriter::is_enabled()) {
3916 ClassListWriter::write(this, cfs);
3917 }
3918
3919 print_class_load_helper(loader_data, module_entry, cfs);
3920 print_class_load_cause_logging();
3921 }
3922
3923 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3924 const ModuleEntry* module_entry,
3925 const ClassFileStream* cfs) const {
3926
3927 if (!log_is_enabled(Info, class, load)) {
3928 return;
3929 }
3930
3931 ResourceMark rm;
3932 LogMessage(class, load) msg;
3933 stringStream info_stream;
3934
3935 // Name and class hierarchy info
3936 info_stream.print("%s", external_name());
3937
3938 // Source
3939 if (cfs != nullptr) {
3940 if (cfs->source() != nullptr) {
3941 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3942 if (module_name != nullptr) {
3943 // When the boot loader created the stream, it didn't know the module name
3944 // yet. Let's format it now.
3945 if (cfs->from_boot_loader_modules_image()) {
3946 info_stream.print(" source: jrt:/%s", module_name);
3947 } else {
3948 info_stream.print(" source: %s", cfs->source());
3949 }
3950 } else {
3951 info_stream.print(" source: %s", cfs->source());
3952 }
3953 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3954 Thread* current = Thread::current();
3955 Klass* caller = current->is_Java_thread() ?
3956 JavaThread::cast(current)->security_get_caller_class(1):
3957 nullptr;
3958 // caller can be null, for example, during a JVMTI VM_Init hook
3959 if (caller != nullptr) {
3960 info_stream.print(" source: instance of %s", caller->external_name());
3961 } else {
3962 // source is unknown
3963 }
3964 } else {
3965 oop class_loader = loader_data->class_loader();
3966 info_stream.print(" source: %s", class_loader->klass()->external_name());
3967 }
3968 } else {
3969 assert(this->in_aot_cache(), "must be");
3970 if (AOTMetaspace::in_aot_cache_dynamic_region((void*)this)) {
3971 info_stream.print(" source: shared objects file (top)");
3972 } else {
3973 info_stream.print(" source: shared objects file");
3974 }
3975 }
3976
3977 msg.info("%s", info_stream.as_string());
3978
3979 if (log_is_enabled(Debug, class, load)) {
3980 stringStream debug_stream;
3981
3982 // Class hierarchy info
3983 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3984 p2i(this), p2i(super()));
3985
3986 // Interfaces
3987 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3988 debug_stream.print(" interfaces:");
3989 int length = local_interfaces()->length();
3990 for (int i = 0; i < length; i++) {
3991 debug_stream.print(" " PTR_FORMAT,
3992 p2i(local_interfaces()->at(i)));
3993 }
3994 }
3995
3996 // Class loader
3997 debug_stream.print(" loader: [");
3998 loader_data->print_value_on(&debug_stream);
3999 debug_stream.print("]");
4000
4001 // Classfile checksum
4002 if (cfs) {
4003 debug_stream.print(" bytes: %d checksum: %08x",
4004 cfs->length(),
4005 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4006 cfs->length()));
4007 }
4008
4009 msg.debug("%s", debug_stream.as_string());
4010 }
4011 }
4012
4013 void InstanceKlass::print_class_load_cause_logging() const {
4014 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4015 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4016 JavaThread* current = JavaThread::current();
4017 ResourceMark rm(current);
4018 const char* name = external_name();
4019
4020 if (LogClassLoadingCauseFor == nullptr ||
4021 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4022 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4023 return;
4024 }
4025
4026 // Log Java stack first
4027 {
4028 LogMessage(class, load, cause) msg;
4029 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4030
4031 info_stream.print_cr("Java stack when loading %s:", name);
4032 current->print_stack_on(&info_stream);
4033 }
4034
4035 // Log native stack second
4036 if (log_cause_native) {
4037 // Log to string first so that lines can be indented
4038 stringStream stack_stream;
4039 char buf[O_BUFLEN];
4040 address lastpc = nullptr;
4041 NativeStackPrinter nsp(current);
4042 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4043 true /* print_source_info */, -1 /* max stack */);
4044
4045 LogMessage(class, load, cause, native) msg;
4046 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4047 info_stream.print_cr("Native stack when loading %s:", name);
4048
4049 // Print each native stack line to the log
4050 int size = (int) stack_stream.size();
4051 char* stack = stack_stream.as_string();
4052 char* stack_end = stack + size;
4053 char* line_start = stack;
4054 for (char* p = stack; p < stack_end; p++) {
4055 if (*p == '\n') {
4056 *p = '\0';
4057 info_stream.print_cr("\t%s", line_start);
4058 line_start = p + 1;
4059 }
4060 }
4061 if (line_start < stack_end) {
4062 info_stream.print_cr("\t%s", line_start);
4063 }
4064 }
4065 }
4066 }
4067
4068 // Verification
4069
4070 class VerifyFieldClosure: public BasicOopIterateClosure {
4071 protected:
4072 template <class T> void do_oop_work(T* p) {
4073 oop obj = RawAccess<>::oop_load(p);
4074 if (!oopDesc::is_oop_or_null(obj)) {
4075 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4076 Universe::print_on(tty);
4077 guarantee(false, "boom");
4078 }
4079 }
4080 public:
4081 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4082 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4083 };
4084
4085 void InstanceKlass::verify_on(outputStream* st) {
4086 #ifndef PRODUCT
4087 // Avoid redundant verifies, this really should be in product.
4088 if (_verify_count == Universe::verify_count()) return;
4089 _verify_count = Universe::verify_count();
4090 #endif
4091
4092 // Verify Klass
4093 Klass::verify_on(st);
4094
4095 // Verify that klass is present in ClassLoaderData
4096 guarantee(class_loader_data()->contains_klass(this),
4097 "this class isn't found in class loader data");
4098
4099 // Verify vtables
4100 if (is_linked()) {
4101 // $$$ This used to be done only for m/s collections. Doing it
4102 // always seemed a valid generalization. (DLD -- 6/00)
4103 vtable().verify(st);
4104 }
4105
4106 // Verify first subklass
4107 if (subklass() != nullptr) {
4108 guarantee(subklass()->is_klass(), "should be klass");
4109 }
4110
4111 // Verify siblings
4112 Klass* super = this->super();
4113 Klass* sib = next_sibling();
4114 if (sib != nullptr) {
4115 if (sib == this) {
4116 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4117 }
4118
4119 guarantee(sib->is_klass(), "should be klass");
4120 guarantee(sib->super() == super, "siblings should have same superklass");
4121 }
4122
4123 // Verify local interfaces
4124 if (local_interfaces()) {
4125 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4126 for (int j = 0; j < local_interfaces->length(); j++) {
4127 InstanceKlass* e = local_interfaces->at(j);
4128 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4129 }
4130 }
4131
4132 // Verify transitive interfaces
4133 if (transitive_interfaces() != nullptr) {
4134 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4135 for (int j = 0; j < transitive_interfaces->length(); j++) {
4136 InstanceKlass* e = transitive_interfaces->at(j);
4137 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4138 }
4139 }
4140
4141 // Verify methods
4142 if (methods() != nullptr) {
4143 Array<Method*>* methods = this->methods();
4144 for (int j = 0; j < methods->length(); j++) {
4145 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4146 }
4147 for (int j = 0; j < methods->length() - 1; j++) {
4148 Method* m1 = methods->at(j);
4149 Method* m2 = methods->at(j + 1);
4150 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4151 }
4152 }
4153
4154 // Verify method ordering
4155 if (method_ordering() != nullptr) {
4156 Array<int>* method_ordering = this->method_ordering();
4157 int length = method_ordering->length();
4158 if (JvmtiExport::can_maintain_original_method_order() ||
4159 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4160 guarantee(length == methods()->length(), "invalid method ordering length");
4161 jlong sum = 0;
4162 for (int j = 0; j < length; j++) {
4163 int original_index = method_ordering->at(j);
4164 guarantee(original_index >= 0, "invalid method ordering index");
4165 guarantee(original_index < length, "invalid method ordering index");
4166 sum += original_index;
4167 }
4168 // Verify sum of indices 0,1,...,length-1
4169 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4170 } else {
4171 guarantee(length == 0, "invalid method ordering length");
4172 }
4173 }
4174
4175 // Verify default methods
4176 if (default_methods() != nullptr) {
4177 Array<Method*>* methods = this->default_methods();
4178 for (int j = 0; j < methods->length(); j++) {
4179 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4180 }
4181 for (int j = 0; j < methods->length() - 1; j++) {
4182 Method* m1 = methods->at(j);
4183 Method* m2 = methods->at(j + 1);
4184 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4185 }
4186 }
4187
4188 // Verify JNI static field identifiers
4189 if (jni_ids() != nullptr) {
4190 jni_ids()->verify(this);
4191 }
4192
4193 // Verify other fields
4194 if (constants() != nullptr) {
4195 guarantee(constants()->is_constantPool(), "should be constant pool");
4196 }
4197 }
4198
4199 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4200 Klass::oop_verify_on(obj, st);
4201 VerifyFieldClosure blk;
4202 obj->oop_iterate(&blk);
4203 }
4204
4205 // JNIid class for jfieldIDs only
4206 // Note to reviewers:
4207 // These JNI functions are just moved over to column 1 and not changed
4208 // in the compressed oops workspace.
4209 JNIid::JNIid(InstanceKlass* holder, int offset, JNIid* next) {
4210 _holder = holder;
4211 _offset = offset;
4212 _next = next;
4213 DEBUG_ONLY(_is_static_field_id = false;)
4214 }
4215
4216 JNIid* JNIid::find(int offset) {
4217 JNIid* current = this;
4218 while (current != nullptr) {
4219 if (current->offset() == offset) return current;
4220 current = current->next();
4221 }
4222 return nullptr;
4223 }
4224
4225 void JNIid::deallocate(JNIid* current) {
4226 while (current != nullptr) {
4227 JNIid* next = current->next();
4228 delete current;
4229 current = next;
4230 }
4231 }
4232
4233 void JNIid::verify(InstanceKlass* holder) {
4234 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4235 int end_field_offset;
4236 end_field_offset = first_field_offset + (holder->static_field_size() * wordSize);
4237
4238 JNIid* current = this;
4239 while (current != nullptr) {
4240 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4241 #ifdef ASSERT
4242 int o = current->offset();
4243 if (current->is_static_field_id()) {
4244 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4245 }
4246 #endif
4247 current = current->next();
4248 }
4249 }
4250
4251 void InstanceKlass::set_init_state(ClassState state) {
4252 #ifdef ASSERT
4253 bool good_state = in_aot_cache() ? (_init_state <= state)
4254 : (_init_state < state);
4255 assert(good_state || state == allocated, "illegal state transition");
4256 #endif
4257 assert(_init_thread == nullptr, "should be cleared before state change");
4258 AtomicAccess::release_store(&_init_state, state);
4259 }
4260
4261 #if INCLUDE_JVMTI
4262
4263 // RedefineClasses() support for previous versions
4264
4265 // Globally, there is at least one previous version of a class to walk
4266 // during class unloading, which is saved because old methods in the class
4267 // are still running. Otherwise the previous version list is cleaned up.
4268 bool InstanceKlass::_should_clean_previous_versions = false;
4269
4270 // Returns true if there are previous versions of a class for class
4271 // unloading only. Also resets the flag to false. purge_previous_version
4272 // will set the flag to true if there are any left, i.e., if there's any
4273 // work to do for next time. This is to avoid the expensive code cache
4274 // walk in CLDG::clean_deallocate_lists().
4275 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4276 bool ret = _should_clean_previous_versions;
4277 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4278 ret ? "true" : "false");
4279 _should_clean_previous_versions = false;
4280 return ret;
4281 }
4282
4283 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4284 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4285 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4286 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4287 Array<Method*>* method_refs = klass->methods();
4288 for (int k = 0; k < method_refs->length(); k++) {
4289 Method* method = method_refs->at(k);
4290 // Only need to clear obsolete methods.
4291 if (method != nullptr && method->is_obsolete()) {
4292 method->clear_jmethod_id();
4293 }
4294 }
4295 }
4296
4297 // Purge previous versions before adding new previous versions of the class and
4298 // during class unloading.
4299 void InstanceKlass::purge_previous_version_list() {
4300 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4301 assert(has_been_redefined(), "Should only be called for main class");
4302
4303 // Quick exit.
4304 if (previous_versions() == nullptr) {
4305 return;
4306 }
4307
4308 // This klass has previous versions so see what we can cleanup
4309 // while it is safe to do so.
4310
4311 int deleted_count = 0; // leave debugging breadcrumbs
4312 int live_count = 0;
4313 ClassLoaderData* loader_data = class_loader_data();
4314 assert(loader_data != nullptr, "should never be null");
4315
4316 ResourceMark rm;
4317 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4318
4319 // previous versions are linked together through the InstanceKlass
4320 InstanceKlass* pv_node = previous_versions();
4321 InstanceKlass* last = this;
4322 int version = 0;
4323
4324 // check the previous versions list
4325 for (; pv_node != nullptr; ) {
4326
4327 ConstantPool* pvcp = pv_node->constants();
4328 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4329
4330 if (!pvcp->on_stack()) {
4331 // If the constant pool isn't on stack, none of the methods
4332 // are executing. Unlink this previous_version.
4333 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4334 // so will be deallocated during the next phase of class unloading.
4335 log_trace(redefine, class, iklass, purge)
4336 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4337 // Unlink from previous version list.
4338 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4339 InstanceKlass* next = pv_node->previous_versions();
4340 clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4341 pv_node->link_previous_versions(nullptr); // point next to null
4342 last->link_previous_versions(next);
4343 // Delete this node directly. Nothing is referring to it and we don't
4344 // want it to increase the counter for metadata to delete in CLDG.
4345 MetadataFactory::free_metadata(loader_data, pv_node);
4346 pv_node = next;
4347 deleted_count++;
4348 version++;
4349 continue;
4350 } else {
4351 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4352 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4353 live_count++;
4354 if (pvcp->in_aot_cache()) {
4355 // Shared previous versions can never be removed so no cleaning is needed.
4356 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4357 } else {
4358 // Previous version alive, set that clean is needed for next time.
4359 _should_clean_previous_versions = true;
4360 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4361 }
4362 }
4363
4364 // next previous version
4365 last = pv_node;
4366 pv_node = pv_node->previous_versions();
4367 version++;
4368 }
4369 log_trace(redefine, class, iklass, purge)
4370 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4371 }
4372
4373 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4374 int emcp_method_count) {
4375 int obsolete_method_count = old_methods->length() - emcp_method_count;
4376
4377 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4378 _previous_versions != nullptr) {
4379 // We have a mix of obsolete and EMCP methods so we have to
4380 // clear out any matching EMCP method entries the hard way.
4381 int local_count = 0;
4382 for (int i = 0; i < old_methods->length(); i++) {
4383 Method* old_method = old_methods->at(i);
4384 if (old_method->is_obsolete()) {
4385 // only obsolete methods are interesting
4386 Symbol* m_name = old_method->name();
4387 Symbol* m_signature = old_method->signature();
4388
4389 // previous versions are linked together through the InstanceKlass
4390 int j = 0;
4391 for (InstanceKlass* prev_version = _previous_versions;
4392 prev_version != nullptr;
4393 prev_version = prev_version->previous_versions(), j++) {
4394
4395 Array<Method*>* method_refs = prev_version->methods();
4396 for (int k = 0; k < method_refs->length(); k++) {
4397 Method* method = method_refs->at(k);
4398
4399 if (!method->is_obsolete() &&
4400 method->name() == m_name &&
4401 method->signature() == m_signature) {
4402 // The current RedefineClasses() call has made all EMCP
4403 // versions of this method obsolete so mark it as obsolete
4404 log_trace(redefine, class, iklass, add)
4405 ("%s(%s): flush obsolete method @%d in version @%d",
4406 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4407
4408 method->set_is_obsolete();
4409 break;
4410 }
4411 }
4412
4413 // The previous loop may not find a matching EMCP method, but
4414 // that doesn't mean that we can optimize and not go any
4415 // further back in the PreviousVersion generations. The EMCP
4416 // method for this generation could have already been made obsolete,
4417 // but there still may be an older EMCP method that has not
4418 // been made obsolete.
4419 }
4420
4421 if (++local_count >= obsolete_method_count) {
4422 // no more obsolete methods so bail out now
4423 break;
4424 }
4425 }
4426 }
4427 }
4428 }
4429
4430 // Save the scratch_class as the previous version if any of the methods are running.
4431 // The previous_versions are used to set breakpoints in EMCP methods and they are
4432 // also used to clean MethodData links to redefined methods that are no longer running.
4433 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4434 int emcp_method_count) {
4435 assert(Thread::current()->is_VM_thread(),
4436 "only VMThread can add previous versions");
4437
4438 ResourceMark rm;
4439 log_trace(redefine, class, iklass, add)
4440 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4441
4442 // Clean out old previous versions for this class
4443 purge_previous_version_list();
4444
4445 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4446 // a previous redefinition may be made obsolete by this redefinition.
4447 Array<Method*>* old_methods = scratch_class->methods();
4448 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4449
4450 // If the constant pool for this previous version of the class
4451 // is not marked as being on the stack, then none of the methods
4452 // in this previous version of the class are on the stack so
4453 // we don't need to add this as a previous version.
4454 ConstantPool* cp_ref = scratch_class->constants();
4455 if (!cp_ref->on_stack()) {
4456 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4457 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4458 return;
4459 }
4460
4461 // Add previous version if any methods are still running or if this is
4462 // a shared class which should never be removed.
4463 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4464 scratch_class->link_previous_versions(previous_versions());
4465 link_previous_versions(scratch_class);
4466 if (cp_ref->in_aot_cache()) {
4467 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4468 } else {
4469 // We only set clean_previous_versions flag for processing during class
4470 // unloading for non-shared classes.
4471 _should_clean_previous_versions = true;
4472 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4473 }
4474 } // end add_previous_version()
4475
4476 #endif // INCLUDE_JVMTI
4477
4478 Method* InstanceKlass::method_with_idnum(int idnum) const {
4479 Method* m = nullptr;
4480 if (idnum < methods()->length()) {
4481 m = methods()->at(idnum);
4482 }
4483 if (m == nullptr || m->method_idnum() != idnum) {
4484 for (int index = 0; index < methods()->length(); ++index) {
4485 m = methods()->at(index);
4486 if (m->method_idnum() == idnum) {
4487 return m;
4488 }
4489 }
4490 // None found, return null for the caller to handle.
4491 return nullptr;
4492 }
4493 return m;
4494 }
4495
4496
4497 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4498 if (idnum >= methods()->length()) {
4499 return nullptr;
4500 }
4501 Method* m = methods()->at(idnum);
4502 if (m != nullptr && m->orig_method_idnum() == idnum) {
4503 return m;
4504 }
4505 // Obsolete method idnum does not match the original idnum
4506 for (int index = 0; index < methods()->length(); ++index) {
4507 m = methods()->at(index);
4508 if (m->orig_method_idnum() == idnum) {
4509 return m;
4510 }
4511 }
4512 // None found, return null for the caller to handle.
4513 return nullptr;
4514 }
4515
4516
4517 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4518 const InstanceKlass* holder = get_klass_version(version);
4519 if (holder == nullptr) {
4520 return nullptr; // The version of klass is gone, no method is found
4521 }
4522 return holder->method_with_orig_idnum(idnum);
4523 }
4524
4525 #if INCLUDE_JVMTI
4526 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4527 return _cached_class_file;
4528 }
4529
4530 jint InstanceKlass::get_cached_class_file_len() {
4531 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4532 }
4533
4534 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4535 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4536 }
4537 #endif
4538
4539 // Make a step iterating over the class hierarchy under the root class.
4540 // Skips subclasses if requested.
4541 void ClassHierarchyIterator::next() {
4542 assert(_current != nullptr, "required");
4543 if (_visit_subclasses && _current->subklass() != nullptr) {
4544 _current = _current->subklass();
4545 return; // visit next subclass
4546 }
4547 _visit_subclasses = true; // reset
4548 while (_current->next_sibling() == nullptr && _current != _root) {
4549 _current = _current->java_super(); // backtrack; no more sibling subclasses left
4550 }
4551 if (_current == _root) {
4552 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4553 _current = nullptr;
4554 return;
4555 }
4556 _current = _current->next_sibling();
4557 return; // visit next sibling subclass
4558 }