1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotClassInitializer.hpp"
26 #include "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "klass.inline.hpp"
55 #include "logging/logMessage.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/allocation.inline.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/metadataFactory.hpp"
60 #include "memory/metaspaceClosure.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/fieldStreams.inline.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/instanceClassLoaderKlass.hpp"
67 #include "oops/instanceKlass.inline.hpp"
68 #include "oops/instanceMirrorKlass.hpp"
69 #include "oops/instanceOop.hpp"
70 #include "oops/instanceStackChunkKlass.hpp"
71 #include "oops/klass.inline.hpp"
72 #include "oops/method.hpp"
73 #include "oops/oop.inline.hpp"
74 #include "oops/recordComponent.hpp"
75 #include "oops/symbol.hpp"
76 #include "prims/jvmtiExport.hpp"
77 #include "prims/jvmtiRedefineClasses.hpp"
78 #include "prims/jvmtiThreadState.hpp"
79 #include "prims/methodComparator.hpp"
80 #include "runtime/arguments.hpp"
81 #include "runtime/deoptimization.hpp"
82 #include "runtime/atomic.hpp"
83 #include "runtime/fieldDescriptor.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/javaCalls.hpp"
86 #include "runtime/javaThread.inline.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/orderAccess.hpp"
89 #include "runtime/os.inline.hpp"
90 #include "runtime/reflection.hpp"
91 #include "runtime/synchronizer.hpp"
92 #include "runtime/threads.hpp"
93 #include "services/classLoadingService.hpp"
94 #include "services/finalizerService.hpp"
95 #include "services/threadService.hpp"
96 #include "utilities/dtrace.hpp"
97 #include "utilities/events.hpp"
98 #include "utilities/macros.hpp"
99 #include "utilities/nativeStackPrinter.hpp"
100 #include "utilities/pair.hpp"
101 #include "utilities/stringUtils.hpp"
102 #ifdef COMPILER1
103 #include "c1/c1_Compiler.hpp"
104 #endif
105 #if INCLUDE_JFR
106 #include "jfr/jfrEvents.hpp"
107 #endif
108
109 #ifdef DTRACE_ENABLED
110
111
112 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
113 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
114 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
115 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
116 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
117 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
118 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
119 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
120 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
121 { \
122 char* data = nullptr; \
123 int len = 0; \
124 Symbol* clss_name = name(); \
125 if (clss_name != nullptr) { \
126 data = (char*)clss_name->bytes(); \
127 len = clss_name->utf8_length(); \
128 } \
129 HOTSPOT_CLASS_INITIALIZATION_##type( \
130 data, len, (void*)class_loader(), thread_type); \
131 }
132
133 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
134 { \
135 char* data = nullptr; \
136 int len = 0; \
137 Symbol* clss_name = name(); \
138 if (clss_name != nullptr) { \
139 data = (char*)clss_name->bytes(); \
140 len = clss_name->utf8_length(); \
141 } \
142 HOTSPOT_CLASS_INITIALIZATION_##type( \
143 data, len, (void*)class_loader(), thread_type, wait); \
144 }
145
146 #else // ndef DTRACE_ENABLED
147
148 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
149 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
150
151 #endif // ndef DTRACE_ENABLED
152
153 bool InstanceKlass::_finalization_enabled = true;
154
155 static inline bool is_class_loader(const Symbol* class_name,
156 const ClassFileParser& parser) {
157 assert(class_name != nullptr, "invariant");
158
159 if (class_name == vmSymbols::java_lang_ClassLoader()) {
160 return true;
161 }
162
163 if (vmClasses::ClassLoader_klass_loaded()) {
164 const Klass* const super_klass = parser.super_klass();
165 if (super_klass != nullptr) {
166 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
167 return true;
168 }
169 }
170 }
171 return false;
172 }
173
174 static inline bool is_stack_chunk_class(const Symbol* class_name,
175 const ClassLoaderData* loader_data) {
176 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
177 loader_data->is_the_null_class_loader_data());
178 }
179
180 // private: called to verify that k is a static member of this nest.
181 // We know that k is an instance class in the same package and hence the
182 // same classloader.
183 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
184 assert(!is_hidden(), "unexpected hidden class");
185 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
186 if (log_is_enabled(Trace, class, nestmates)) {
187 ResourceMark rm(current);
188 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
189 k->external_name(), this->external_name());
190 }
191 return false;
192 }
193
194 if (log_is_enabled(Trace, class, nestmates)) {
195 ResourceMark rm(current);
196 log_trace(class, nestmates)("Checking nest membership of %s in %s",
197 k->external_name(), this->external_name());
198 }
199
200 // Check for the named class in _nest_members.
201 // We don't resolve, or load, any classes.
202 for (int i = 0; i < _nest_members->length(); i++) {
203 int cp_index = _nest_members->at(i);
204 Symbol* name = _constants->klass_name_at(cp_index);
205 if (name == k->name()) {
206 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
207 return true;
208 }
209 }
210 log_trace(class, nestmates)("- class is NOT a nest member!");
211 return false;
212 }
213
214 // Called to verify that k is a permitted subclass of this class.
215 // The incoming stringStream is used to format the messages for error logging and for the caller
216 // to use for exception throwing.
217 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
218 Thread* current = Thread::current();
219 assert(k != nullptr, "sanity check");
220 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
221 "unexpected empty _permitted_subclasses array");
222
223 if (log_is_enabled(Trace, class, sealed)) {
224 ResourceMark rm(current);
225 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
226 k->external_name(), this->external_name());
227 }
228
229 // Check that the class and its super are in the same module.
230 if (k->module() != this->module()) {
231 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
232 "and sealed class %s is in module '%s' with loader %s",
233 k->external_name(),
234 k->module()->name_as_C_string(),
235 k->module()->loader_data()->loader_name_and_id(),
236 this->external_name(),
237 this->module()->name_as_C_string(),
238 this->module()->loader_data()->loader_name_and_id());
239 log_trace(class, sealed)(" - %s", ss.as_string());
240 return false;
241 }
242
243 if (!k->is_public() && !is_same_class_package(k)) {
244 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
245 "and sealed class %s is in package '%s' with classloader %s",
246 k->external_name(),
247 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
248 k->module()->loader_data()->loader_name_and_id(),
249 this->external_name(),
250 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
251 this->module()->loader_data()->loader_name_and_id());
252 log_trace(class, sealed)(" - %s", ss.as_string());
253 return false;
254 }
255
256 for (int i = 0; i < _permitted_subclasses->length(); i++) {
257 int cp_index = _permitted_subclasses->at(i);
258 Symbol* name = _constants->klass_name_at(cp_index);
259 if (name == k->name()) {
260 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
261 return true;
262 }
263 }
264
265 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
266 k->external_name(), this->external_name());
267 log_trace(class, sealed)(" - %s", ss.as_string());
268 return false;
269 }
270
271 // Return nest-host class, resolving, validating and saving it if needed.
272 // In cases where this is called from a thread that cannot do classloading
273 // (such as a native JIT thread) then we simply return null, which in turn
274 // causes the access check to return false. Such code will retry the access
275 // from a more suitable environment later. Otherwise the _nest_host is always
276 // set once this method returns.
277 // Any errors from nest-host resolution must be preserved so they can be queried
278 // from higher-level access checking code, and reported as part of access checking
279 // exceptions.
280 // VirtualMachineErrors are propagated with a null return.
281 // Under any conditions where the _nest_host can be set to non-null the resulting
282 // value of it and, if applicable, the nest host resolution/validation error,
283 // are idempotent.
284 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
285 InstanceKlass* nest_host_k = _nest_host;
286 if (nest_host_k != nullptr) {
287 return nest_host_k;
288 }
289
290 ResourceMark rm(THREAD);
291
292 // need to resolve and save our nest-host class.
293 if (_nest_host_index != 0) { // we have a real nest_host
294 // Before trying to resolve check if we're in a suitable context
295 bool can_resolve = THREAD->can_call_java();
296 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
297 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
298 this->external_name());
299 return nullptr; // sentinel to say "try again from a different context"
300 }
301
302 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
303 this->external_name(),
304 _constants->klass_name_at(_nest_host_index)->as_C_string());
305
306 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
307 if (HAS_PENDING_EXCEPTION) {
308 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
309 return nullptr; // propagate VMEs
310 }
311 stringStream ss;
312 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
313 ss.print("Nest host resolution of %s with host %s failed: ",
314 this->external_name(), target_host_class);
315 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
316 const char* msg = ss.as_string(true /* on C-heap */);
317 constantPoolHandle cph(THREAD, constants());
318 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
319 CLEAR_PENDING_EXCEPTION;
320
321 log_trace(class, nestmates)("%s", msg);
322 } else {
323 // A valid nest-host is an instance class in the current package that lists this
324 // class as a nest member. If any of these conditions are not met the class is
325 // its own nest-host.
326 const char* error = nullptr;
327
328 // JVMS 5.4.4 indicates package check comes first
329 if (is_same_class_package(k)) {
330 // Now check actual membership. We can't be a member if our "host" is
331 // not an instance class.
332 if (k->is_instance_klass()) {
333 nest_host_k = InstanceKlass::cast(k);
334 bool is_member = nest_host_k->has_nest_member(THREAD, this);
335 if (is_member) {
336 _nest_host = nest_host_k; // save resolved nest-host value
337
338 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
339 this->external_name(), k->external_name());
340 return nest_host_k;
341 } else {
342 error = "current type is not listed as a nest member";
343 }
344 } else {
345 error = "host is not an instance class";
346 }
347 } else {
348 error = "types are in different packages";
349 }
350
351 // something went wrong, so record what and log it
352 {
353 stringStream ss;
354 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
355 this->external_name(),
356 this->class_loader_data()->loader_name_and_id(),
357 k->external_name(),
358 k->class_loader_data()->loader_name_and_id(),
359 error);
360 const char* msg = ss.as_string(true /* on C-heap */);
361 constantPoolHandle cph(THREAD, constants());
362 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
363 log_trace(class, nestmates)("%s", msg);
364 }
365 }
366 } else {
367 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
368 this->external_name());
369 }
370
371 // Either not in an explicit nest, or else an error occurred, so
372 // the nest-host is set to `this`. Any thread that sees this assignment
373 // will also see any setting of nest_host_error(), if applicable.
374 return (_nest_host = this);
375 }
376
377 // Dynamic nest member support: set this class's nest host to the given class.
378 // This occurs as part of the class definition, as soon as the instanceKlass
379 // has been created and doesn't require further resolution. The code:
380 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
381 // results in:
382 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
383 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
384 // We also know the "host" is a valid nest-host in the same package so we can
385 // assert some of those facts.
386 void InstanceKlass::set_nest_host(InstanceKlass* host) {
387 assert(is_hidden(), "must be a hidden class");
388 assert(host != nullptr, "null nest host specified");
389 assert(_nest_host == nullptr, "current class has resolved nest-host");
390 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
391 nest_host_error());
392 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
393 (host->_nest_host == host), "proposed host is not a valid nest-host");
394 // Can't assert this as package is not set yet:
395 // assert(is_same_class_package(host), "proposed host is in wrong package");
396
397 if (log_is_enabled(Trace, class, nestmates)) {
398 ResourceMark rm;
399 const char* msg = "";
400 // a hidden class does not expect a statically defined nest-host
401 if (_nest_host_index > 0) {
402 msg = "(the NestHost attribute in the current class is ignored)";
403 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
404 msg = "(the NestMembers attribute in the current class is ignored)";
405 }
406 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
407 this->external_name(),
408 host->external_name(),
409 msg);
410 }
411 // set dynamic nest host
412 _nest_host = host;
413 // Record dependency to keep nest host from being unloaded before this class.
414 ClassLoaderData* this_key = class_loader_data();
415 assert(this_key != nullptr, "sanity");
416 this_key->record_dependency(host);
417 }
418
419 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
420 // or we are k's nest_host - all of which is covered by comparing the two
421 // resolved_nest_hosts.
422 // Any exceptions (i.e. VMEs) are propagated.
423 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
424
425 assert(this != k, "this should be handled by higher-level code");
426
427 // Per JVMS 5.4.4 we first resolve and validate the current class, then
428 // the target class k.
429
430 InstanceKlass* cur_host = nest_host(CHECK_false);
431 if (cur_host == nullptr) {
432 return false;
433 }
434
435 Klass* k_nest_host = k->nest_host(CHECK_false);
436 if (k_nest_host == nullptr) {
437 return false;
438 }
439
440 bool access = (cur_host == k_nest_host);
441
442 ResourceMark rm(THREAD);
443 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
444 this->external_name(),
445 access ? "" : "NOT ",
446 k->external_name());
447 return access;
448 }
449
450 const char* InstanceKlass::nest_host_error() {
451 if (_nest_host_index == 0) {
452 return nullptr;
453 } else {
454 constantPoolHandle cph(Thread::current(), constants());
455 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
456 }
457 }
458
459 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
460 bool use_class_space, TRAPS) throw() {
461 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
462 }
463
464 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
465 const int size = InstanceKlass::size(parser.vtable_size(),
466 parser.itable_size(),
467 nonstatic_oop_map_size(parser.total_oop_map_count()),
468 parser.is_interface());
469
470 const Symbol* const class_name = parser.class_name();
471 assert(class_name != nullptr, "invariant");
472 ClassLoaderData* loader_data = parser.loader_data();
473 assert(loader_data != nullptr, "invariant");
474
475 InstanceKlass* ik;
476 const bool use_class_space = parser.klass_needs_narrow_id();
477
478 // Allocation
479 if (parser.is_instance_ref_klass()) {
480 // java.lang.ref.Reference
481 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
482 } else if (class_name == vmSymbols::java_lang_Class()) {
483 // mirror - java.lang.Class
484 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
485 } else if (is_stack_chunk_class(class_name, loader_data)) {
486 // stack chunk
487 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
488 } else if (is_class_loader(class_name, parser)) {
489 // class loader - java.lang.ClassLoader
490 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
491 } else {
492 // normal
493 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
494 }
495
496 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
497 assert(CompressedKlassPointers::is_encodable(ik),
498 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
499 }
500
501 // Check for pending exception before adding to the loader data and incrementing
502 // class count. Can get OOM here.
503 if (HAS_PENDING_EXCEPTION) {
504 return nullptr;
505 }
506
507 return ik;
508 }
509
510
511 // copy method ordering from resource area to Metaspace
512 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
513 if (m != nullptr) {
514 // allocate a new array and copy contents (memcpy?)
515 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
516 for (int i = 0; i < m->length(); i++) {
517 _method_ordering->at_put(i, m->at(i));
518 }
519 } else {
520 _method_ordering = Universe::the_empty_int_array();
521 }
522 }
523
524 // create a new array of vtable_indices for default methods
525 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
526 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
527 assert(default_vtable_indices() == nullptr, "only create once");
528 set_default_vtable_indices(vtable_indices);
529 return vtable_indices;
530 }
531
532
533 InstanceKlass::InstanceKlass() {
534 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
535 }
536
537 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
538 Klass(kind),
539 _nest_members(nullptr),
540 _nest_host(nullptr),
541 _permitted_subclasses(nullptr),
542 _record_components(nullptr),
543 _static_field_size(parser.static_field_size()),
544 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
545 _itable_len(parser.itable_size()),
546 _nest_host_index(0),
547 _init_state(allocated),
548 _reference_type(reference_type),
549 _init_thread(nullptr),
550 _hash_offset(parser.hash_offset())
551 {
552 set_vtable_length(parser.vtable_size());
553 set_access_flags(parser.access_flags());
554 if (parser.is_hidden()) set_is_hidden();
555 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
556 false));
557
558 assert(nullptr == _methods, "underlying memory not zeroed?");
559 assert(is_instance_klass(), "is layout incorrect?");
560 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
561 }
562
563 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
564 Array<Method*>* methods) {
565 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
566 !methods->is_shared()) {
567 for (int i = 0; i < methods->length(); i++) {
568 Method* method = methods->at(i);
569 if (method == nullptr) continue; // maybe null if error processing
570 // Only want to delete methods that are not executing for RedefineClasses.
571 // The previous version will point to them so they're not totally dangling
572 assert (!method->on_stack(), "shouldn't be called with methods on stack");
573 MetadataFactory::free_metadata(loader_data, method);
574 }
575 MetadataFactory::free_array<Method*>(loader_data, methods);
576 }
577 }
578
579 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
580 const Klass* super_klass,
581 Array<InstanceKlass*>* local_interfaces,
582 Array<InstanceKlass*>* transitive_interfaces) {
583 // Only deallocate transitive interfaces if not empty, same as super class
584 // or same as local interfaces. See code in parseClassFile.
585 Array<InstanceKlass*>* ti = transitive_interfaces;
586 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
587 // check that the interfaces don't come from super class
588 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
589 InstanceKlass::cast(super_klass)->transitive_interfaces();
590 if (ti != sti && ti != nullptr && !ti->is_shared()) {
591 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
592 }
593 }
594
595 // local interfaces can be empty
596 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
597 local_interfaces != nullptr && !local_interfaces->is_shared()) {
598 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
599 }
600 }
601
602 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
603 Array<RecordComponent*>* record_components) {
604 if (record_components != nullptr && !record_components->is_shared()) {
605 for (int i = 0; i < record_components->length(); i++) {
606 RecordComponent* record_component = record_components->at(i);
607 MetadataFactory::free_metadata(loader_data, record_component);
608 }
609 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
610 }
611 }
612
613 // This function deallocates the metadata and C heap pointers that the
614 // InstanceKlass points to.
615 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
616 // Orphan the mirror first, CMS thinks it's still live.
617 if (java_mirror() != nullptr) {
618 java_lang_Class::set_klass(java_mirror(), nullptr);
619 }
620
621 // Also remove mirror from handles
622 loader_data->remove_handle(_java_mirror);
623
624 // Need to take this class off the class loader data list.
625 loader_data->remove_class(this);
626
627 // The array_klass for this class is created later, after error handling.
628 // For class redefinition, we keep the original class so this scratch class
629 // doesn't have an array class. Either way, assert that there is nothing
630 // to deallocate.
631 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
632
633 // Release C heap allocated data that this points to, which includes
634 // reference counting symbol names.
635 // Can't release the constant pool or MethodData C heap data here because the constant
636 // pool can be deallocated separately from the InstanceKlass for default methods and
637 // redefine classes. MethodData can also be released separately.
638 release_C_heap_structures(/* release_sub_metadata */ false);
639
640 deallocate_methods(loader_data, methods());
641 set_methods(nullptr);
642
643 deallocate_record_components(loader_data, record_components());
644 set_record_components(nullptr);
645
646 if (method_ordering() != nullptr &&
647 method_ordering() != Universe::the_empty_int_array() &&
648 !method_ordering()->is_shared()) {
649 MetadataFactory::free_array<int>(loader_data, method_ordering());
650 }
651 set_method_ordering(nullptr);
652
653 // default methods can be empty
654 if (default_methods() != nullptr &&
655 default_methods() != Universe::the_empty_method_array() &&
656 !default_methods()->is_shared()) {
657 MetadataFactory::free_array<Method*>(loader_data, default_methods());
658 }
659 // Do NOT deallocate the default methods, they are owned by superinterfaces.
660 set_default_methods(nullptr);
661
662 // default methods vtable indices can be empty
663 if (default_vtable_indices() != nullptr &&
664 !default_vtable_indices()->is_shared()) {
665 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
666 }
667 set_default_vtable_indices(nullptr);
668
669
670 // This array is in Klass, but remove it with the InstanceKlass since
671 // this place would be the only caller and it can share memory with transitive
672 // interfaces.
673 if (secondary_supers() != nullptr &&
674 secondary_supers() != Universe::the_empty_klass_array() &&
675 // see comments in compute_secondary_supers about the following cast
676 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
677 !secondary_supers()->is_shared()) {
678 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
679 }
680 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
681
682 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
683 set_transitive_interfaces(nullptr);
684 set_local_interfaces(nullptr);
685
686 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
687 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
688 }
689 set_fieldinfo_stream(nullptr);
690
691 if (fields_status() != nullptr && !fields_status()->is_shared()) {
692 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
693 }
694 set_fields_status(nullptr);
695
696 // If a method from a redefined class is using this constant pool, don't
697 // delete it, yet. The new class's previous version will point to this.
698 if (constants() != nullptr) {
699 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
700 if (!constants()->is_shared()) {
701 MetadataFactory::free_metadata(loader_data, constants());
702 }
703 // Delete any cached resolution errors for the constant pool
704 SystemDictionary::delete_resolution_error(constants());
705
706 set_constants(nullptr);
707 }
708
709 if (inner_classes() != nullptr &&
710 inner_classes() != Universe::the_empty_short_array() &&
711 !inner_classes()->is_shared()) {
712 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
713 }
714 set_inner_classes(nullptr);
715
716 if (nest_members() != nullptr &&
717 nest_members() != Universe::the_empty_short_array() &&
718 !nest_members()->is_shared()) {
719 MetadataFactory::free_array<jushort>(loader_data, nest_members());
720 }
721 set_nest_members(nullptr);
722
723 if (permitted_subclasses() != nullptr &&
724 permitted_subclasses() != Universe::the_empty_short_array() &&
725 !permitted_subclasses()->is_shared()) {
726 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
727 }
728 set_permitted_subclasses(nullptr);
729
730 // We should deallocate the Annotations instance if it's not in shared spaces.
731 if (annotations() != nullptr && !annotations()->is_shared()) {
732 MetadataFactory::free_metadata(loader_data, annotations());
733 }
734 set_annotations(nullptr);
735
736 SystemDictionaryShared::handle_class_unloading(this);
737
738 #if INCLUDE_CDS_JAVA_HEAP
739 if (CDSConfig::is_dumping_heap()) {
740 HeapShared::remove_scratch_objects(this);
741 }
742 #endif
743 }
744
745 bool InstanceKlass::is_record() const {
746 return _record_components != nullptr &&
747 is_final() &&
748 java_super() == vmClasses::Record_klass();
749 }
750
751 bool InstanceKlass::is_sealed() const {
752 return _permitted_subclasses != nullptr &&
753 _permitted_subclasses != Universe::the_empty_short_array();
754 }
755
756 // JLS 8.9: An enum class is either implicitly final and derives
757 // from java.lang.Enum, or else is implicitly sealed to its
758 // anonymous subclasses. This query detects both kinds.
759 // It does not validate the finality or
760 // sealing conditions: it merely checks for a super of Enum.
761 // This is sufficient for recognizing well-formed enums.
762 bool InstanceKlass::is_enum_subclass() const {
763 InstanceKlass* s = java_super();
764 return (s == vmClasses::Enum_klass() ||
765 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
766 }
767
768 bool InstanceKlass::should_be_initialized() const {
769 return !is_initialized();
770 }
771
772 klassItable InstanceKlass::itable() const {
773 return klassItable(const_cast<InstanceKlass*>(this));
774 }
775
776 // JVMTI spec thinks there are signers and protection domain in the
777 // instanceKlass. These accessors pretend these fields are there.
778 // The hprof specification also thinks these fields are in InstanceKlass.
779 oop InstanceKlass::protection_domain() const {
780 // return the protection_domain from the mirror
781 return java_lang_Class::protection_domain(java_mirror());
782 }
783
784 objArrayOop InstanceKlass::signers() const {
785 // return the signers from the mirror
786 return java_lang_Class::signers(java_mirror());
787 }
788
789 oop InstanceKlass::init_lock() const {
790 // return the init lock from the mirror
791 oop lock = java_lang_Class::init_lock(java_mirror());
792 // Prevent reordering with any access of initialization state
793 OrderAccess::loadload();
794 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
795 "only fully initialized state can have a null lock");
796 return lock;
797 }
798
799 // Set the initialization lock to null so the object can be GC'ed. Any racing
800 // threads to get this lock will see a null lock and will not lock.
801 // That's okay because they all check for initialized state after getting
802 // the lock and return.
803 void InstanceKlass::fence_and_clear_init_lock() {
804 // make sure previous stores are all done, notably the init_state.
805 OrderAccess::storestore();
806 java_lang_Class::clear_init_lock(java_mirror());
807 assert(!is_not_initialized(), "class must be initialized now");
808 }
809
810
811 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
812 // process. The step comments refers to the procedure described in that section.
813 // Note: implementation moved to static method to expose the this pointer.
814 void InstanceKlass::initialize(TRAPS) {
815 if (this->should_be_initialized()) {
816 initialize_impl(CHECK);
817 // Note: at this point the class may be initialized
818 // OR it may be in the state of being initialized
819 // in case of recursive initialization!
820 } else {
821 assert(is_initialized(), "sanity check");
822 }
823 }
824
825 #ifdef ASSERT
826 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
827 assert(has_aot_initialized_mirror(), "must be");
828
829 InstanceKlass* s = java_super();
830 if (s != nullptr) {
831 DEBUG_ONLY(ResourceMark rm);
832 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
833 s->external_name(), external_name());
834 s->assert_no_clinit_will_run_for_aot_initialized_class();
835 }
836
837 Array<InstanceKlass*>* interfaces = local_interfaces();
838 int len = interfaces->length();
839 for (int i = 0; i < len; i++) {
840 InstanceKlass* intf = interfaces->at(i);
841 if (!intf->is_initialized()) {
842 ResourceMark rm;
843 // Note: an interface needs to be marked as is_initialized() only if
844 // - it has a <clinit>
845 // - it has declared a default method.
846 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
847 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
848 intf->external_name(), external_name());
849 }
850 }
851 }
852 #endif
853
854 #if INCLUDE_CDS
855 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
856 assert(has_aot_initialized_mirror(), "must be");
857 assert(CDSConfig::is_loading_heap(), "must be");
858 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
859 assert_no_clinit_will_run_for_aot_initialized_class();
860
861 if (is_initialized()) {
862 return;
863 }
864
865 if (log_is_enabled(Info, cds, init)) {
866 ResourceMark rm;
867 log_info(cds, init)("%s (aot-inited)", external_name());
868 }
869
870 link_class(CHECK);
871
872 #ifdef ASSERT
873 {
874 Handle h_init_lock(THREAD, init_lock());
875 ObjectLocker ol(h_init_lock, THREAD);
876 assert(!is_initialized(), "sanity");
877 assert(!is_being_initialized(), "sanity");
878 assert(!is_in_error_state(), "sanity");
879 }
880 #endif
881
882 set_init_thread(THREAD);
883 AOTClassInitializer::call_runtime_setup(THREAD, this);
884 set_initialization_state_and_notify(fully_initialized, CHECK);
885 }
886 #endif
887
888 bool InstanceKlass::verify_code(TRAPS) {
889 // 1) Verify the bytecodes
890 return Verifier::verify(this, should_verify_class(), THREAD);
891 }
892
893 void InstanceKlass::link_class(TRAPS) {
894 assert(is_loaded(), "must be loaded");
895 if (!is_linked()) {
896 link_class_impl(CHECK);
897 }
898 }
899
900 // Called to verify that a class can link during initialization, without
901 // throwing a VerifyError.
902 bool InstanceKlass::link_class_or_fail(TRAPS) {
903 assert(is_loaded(), "must be loaded");
904 if (!is_linked()) {
905 link_class_impl(CHECK_false);
906 }
907 return is_linked();
908 }
909
910 bool InstanceKlass::link_class_impl(TRAPS) {
911 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
912 // This is for CDS static dump only -- we use the in_error_state to indicate that
913 // the class has failed verification. Throwing the NoClassDefFoundError here is just
914 // a convenient way to stop repeat attempts to verify the same (bad) class.
915 //
916 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
917 // if we are executing Java code. This is not a problem for CDS dumping phase since
918 // it doesn't execute any Java code.
919 ResourceMark rm(THREAD);
920 // Names are all known to be < 64k so we know this formatted message is not excessively large.
921 Exceptions::fthrow(THREAD_AND_LOCATION,
922 vmSymbols::java_lang_NoClassDefFoundError(),
923 "Class %s, or one of its supertypes, failed class initialization",
924 external_name());
925 return false;
926 }
927 // return if already verified
928 if (is_linked()) {
929 return true;
930 }
931
932 // Timing
933 // timer handles recursion
934 JavaThread* jt = THREAD;
935
936 // link super class before linking this class
937 Klass* super_klass = super();
938 if (super_klass != nullptr) {
939 if (super_klass->is_interface()) { // check if super class is an interface
940 ResourceMark rm(THREAD);
941 // Names are all known to be < 64k so we know this formatted message is not excessively large.
942 Exceptions::fthrow(
943 THREAD_AND_LOCATION,
944 vmSymbols::java_lang_IncompatibleClassChangeError(),
945 "class %s has interface %s as super class",
946 external_name(),
947 super_klass->external_name()
948 );
949 return false;
950 }
951
952 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
953 ik_super->link_class_impl(CHECK_false);
954 }
955
956 // link all interfaces implemented by this class before linking this class
957 Array<InstanceKlass*>* interfaces = local_interfaces();
958 int num_interfaces = interfaces->length();
959 for (int index = 0; index < num_interfaces; index++) {
960 InstanceKlass* interk = interfaces->at(index);
961 interk->link_class_impl(CHECK_false);
962 }
963
964 // in case the class is linked in the process of linking its superclasses
965 if (is_linked()) {
966 return true;
967 }
968
969 // trace only the link time for this klass that includes
970 // the verification time
971 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
972 ClassLoader::perf_class_link_selftime(),
973 ClassLoader::perf_classes_linked(),
974 jt->get_thread_stat()->perf_recursion_counts_addr(),
975 jt->get_thread_stat()->perf_timers_addr(),
976 PerfClassTraceTime::CLASS_LINK);
977
978 // verification & rewriting
979 {
980 HandleMark hm(THREAD);
981 Handle h_init_lock(THREAD, init_lock());
982 ObjectLocker ol(h_init_lock, jt);
983 // rewritten will have been set if loader constraint error found
984 // on an earlier link attempt
985 // don't verify or rewrite if already rewritten
986 //
987
988 if (!is_linked()) {
989 if (!is_rewritten()) {
990 if (is_shared()) {
991 assert(!verified_at_dump_time(), "must be");
992 }
993 {
994 bool verify_ok = verify_code(THREAD);
995 if (!verify_ok) {
996 return false;
997 }
998 }
999
1000 // Just in case a side-effect of verify linked this class already
1001 // (which can sometimes happen since the verifier loads classes
1002 // using custom class loaders, which are free to initialize things)
1003 if (is_linked()) {
1004 return true;
1005 }
1006
1007 // also sets rewritten
1008 rewrite_class(CHECK_false);
1009 } else if (is_shared()) {
1010 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1011 }
1012
1013 // relocate jsrs and link methods after they are all rewritten
1014 link_methods(CHECK_false);
1015
1016 // Initialize the vtable and interface table after
1017 // methods have been rewritten since rewrite may
1018 // fabricate new Method*s.
1019 // also does loader constraint checking
1020 //
1021 // initialize_vtable and initialize_itable need to be rerun
1022 // for a shared class if
1023 // 1) the class is loaded by custom class loader or
1024 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1025 // 3) the class was not verified during dump time
1026 bool need_init_table = true;
1027 if (is_shared() && verified_at_dump_time() &&
1028 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1029 need_init_table = false;
1030 }
1031 if (need_init_table) {
1032 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1033 itable().initialize_itable_and_check_constraints(CHECK_false);
1034 }
1035 #ifdef ASSERT
1036 vtable().verify(tty, true);
1037 // In case itable verification is ever added.
1038 // itable().verify(tty, true);
1039 #endif
1040 if (Universe::is_fully_initialized()) {
1041 DeoptimizationScope deopt_scope;
1042 {
1043 // Now mark all code that assumes the class is not linked.
1044 // Set state under the Compile_lock also.
1045 MutexLocker ml(THREAD, Compile_lock);
1046
1047 set_init_state(linked);
1048 CodeCache::mark_dependents_on(&deopt_scope, this);
1049 }
1050 // Perform the deopt handshake outside Compile_lock.
1051 deopt_scope.deoptimize_marked();
1052 } else {
1053 set_init_state(linked);
1054 }
1055 if (JvmtiExport::should_post_class_prepare()) {
1056 JvmtiExport::post_class_prepare(THREAD, this);
1057 }
1058 }
1059 }
1060 return true;
1061 }
1062
1063 // Rewrite the byte codes of all of the methods of a class.
1064 // The rewriter must be called exactly once. Rewriting must happen after
1065 // verification but before the first method of the class is executed.
1066 void InstanceKlass::rewrite_class(TRAPS) {
1067 assert(is_loaded(), "must be loaded");
1068 if (is_rewritten()) {
1069 assert(is_shared(), "rewriting an unshared class?");
1070 return;
1071 }
1072 Rewriter::rewrite(this, CHECK);
1073 set_rewritten();
1074 }
1075
1076 // Now relocate and link method entry points after class is rewritten.
1077 // This is outside is_rewritten flag. In case of an exception, it can be
1078 // executed more than once.
1079 void InstanceKlass::link_methods(TRAPS) {
1080 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1081
1082 int len = methods()->length();
1083 for (int i = len-1; i >= 0; i--) {
1084 methodHandle m(THREAD, methods()->at(i));
1085
1086 // Set up method entry points for compiler and interpreter .
1087 m->link_method(m, CHECK);
1088 }
1089 }
1090
1091 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1092 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1093 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1094 for (int i = 0; i < local_interfaces()->length(); ++i) {
1095 InstanceKlass* ik = local_interfaces()->at(i);
1096
1097 // Initialization is depth first search ie. we start with top of the inheritance tree
1098 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1099 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1100 if (ik->has_nonstatic_concrete_methods()) {
1101 ik->initialize_super_interfaces(CHECK);
1102 }
1103
1104 // Only initialize() interfaces that "declare" concrete methods.
1105 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1106 ik->initialize(CHECK);
1107 }
1108 }
1109 }
1110
1111 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1112 static InitializationErrorTable* _initialization_error_table;
1113
1114 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1115 // Create the same exception with a message indicating the thread name,
1116 // and the StackTraceElements.
1117 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1118 ResourceMark rm(current);
1119 if (init_error.is_null()) {
1120 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1121
1122 // We failed to create the new exception, most likely due to either out-of-memory or
1123 // a stackoverflow error. If the original exception was either of those then we save
1124 // the shared, pre-allocated, stackless, instance of that exception.
1125 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1126 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1127 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1128 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1129 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1130 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1131 } else {
1132 return;
1133 }
1134 }
1135
1136 MutexLocker ml(current, ClassInitError_lock);
1137 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1138 bool created;
1139 if (_initialization_error_table == nullptr) {
1140 _initialization_error_table = new (mtClass) InitializationErrorTable();
1141 }
1142 _initialization_error_table->put_if_absent(this, elem, &created);
1143 assert(created, "Initialization is single threaded");
1144 log_trace(class, init)("Initialization error added for class %s", external_name());
1145 }
1146
1147 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1148 MutexLocker ml(current, ClassInitError_lock);
1149 if (_initialization_error_table == nullptr) {
1150 return nullptr;
1151 }
1152 OopHandle* h = _initialization_error_table->get(this);
1153 return (h != nullptr) ? h->resolve() : nullptr;
1154 }
1155
1156 // Need to remove entries for unloaded classes.
1157 void InstanceKlass::clean_initialization_error_table() {
1158 struct InitErrorTableCleaner {
1159 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1160 if (!ik->is_loader_alive()) {
1161 h.release(Universe::vm_global());
1162 return true;
1163 } else {
1164 return false;
1165 }
1166 }
1167 };
1168
1169 assert_locked_or_safepoint(ClassInitError_lock);
1170 InitErrorTableCleaner cleaner;
1171 if (_initialization_error_table != nullptr) {
1172 _initialization_error_table->unlink(&cleaner);
1173 }
1174 }
1175
1176 void InstanceKlass::initialize_impl(TRAPS) {
1177 HandleMark hm(THREAD);
1178
1179 // Make sure klass is linked (verified) before initialization
1180 // A class could already be verified, since it has been reflected upon.
1181 link_class(CHECK);
1182
1183 DTRACE_CLASSINIT_PROBE(required, -1);
1184
1185 bool wait = false;
1186
1187 JavaThread* jt = THREAD;
1188
1189 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1190
1191 // refer to the JVM book page 47 for description of steps
1192 // Step 1
1193 {
1194 Handle h_init_lock(THREAD, init_lock());
1195 ObjectLocker ol(h_init_lock, jt);
1196
1197 // Step 2
1198 // If we were to use wait() instead of waitInterruptibly() then
1199 // we might end up throwing IE from link/symbol resolution sites
1200 // that aren't expected to throw. This would wreak havoc. See 6320309.
1201 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1202 if (debug_logging_enabled) {
1203 ResourceMark rm(jt);
1204 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1205 jt->name(), external_name(), init_thread_name());
1206 }
1207 wait = true;
1208 jt->set_class_to_be_initialized(this);
1209 ol.wait_uninterruptibly(jt);
1210 jt->set_class_to_be_initialized(nullptr);
1211 }
1212
1213 // Step 3
1214 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1215 if (debug_logging_enabled) {
1216 ResourceMark rm(jt);
1217 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1218 jt->name(), external_name());
1219 }
1220 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1221 return;
1222 }
1223
1224 // Step 4
1225 if (is_initialized()) {
1226 if (debug_logging_enabled) {
1227 ResourceMark rm(jt);
1228 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1229 jt->name(), external_name());
1230 }
1231 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1232 return;
1233 }
1234
1235 // Step 5
1236 if (is_in_error_state()) {
1237 if (debug_logging_enabled) {
1238 ResourceMark rm(jt);
1239 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1240 jt->name(), external_name());
1241 }
1242
1243 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1244 ResourceMark rm(THREAD);
1245 Handle cause(THREAD, get_initialization_error(THREAD));
1246
1247 stringStream ss;
1248 ss.print("Could not initialize class %s", external_name());
1249 if (cause.is_null()) {
1250 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1251 } else {
1252 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1253 ss.as_string(), cause);
1254 }
1255 } else {
1256
1257 // Step 6
1258 set_init_state(being_initialized);
1259 set_init_thread(jt);
1260 if (debug_logging_enabled) {
1261 ResourceMark rm(jt);
1262 log_debug(class, init)("Thread \"%s\" is initializing %s",
1263 jt->name(), external_name());
1264 }
1265 }
1266 }
1267
1268 // Step 7
1269 // Next, if C is a class rather than an interface, initialize it's super class and super
1270 // interfaces.
1271 if (!is_interface()) {
1272 Klass* super_klass = super();
1273 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1274 super_klass->initialize(THREAD);
1275 }
1276 // If C implements any interface that declares a non-static, concrete method,
1277 // the initialization of C triggers initialization of its super interfaces.
1278 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1279 // having a superinterface that declares, non-static, concrete methods
1280 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1281 initialize_super_interfaces(THREAD);
1282 }
1283
1284 // If any exceptions, complete abruptly, throwing the same exception as above.
1285 if (HAS_PENDING_EXCEPTION) {
1286 Handle e(THREAD, PENDING_EXCEPTION);
1287 CLEAR_PENDING_EXCEPTION;
1288 {
1289 EXCEPTION_MARK;
1290 add_initialization_error(THREAD, e);
1291 // Locks object, set state, and notify all waiting threads
1292 set_initialization_state_and_notify(initialization_error, THREAD);
1293 CLEAR_PENDING_EXCEPTION;
1294 }
1295 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1296 THROW_OOP(e());
1297 }
1298 }
1299
1300
1301 // Step 8
1302 {
1303 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1304 if (class_initializer() != nullptr) {
1305 // Timer includes any side effects of class initialization (resolution,
1306 // etc), but not recursive entry into call_class_initializer().
1307 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1308 ClassLoader::perf_class_init_selftime(),
1309 ClassLoader::perf_classes_inited(),
1310 jt->get_thread_stat()->perf_recursion_counts_addr(),
1311 jt->get_thread_stat()->perf_timers_addr(),
1312 PerfClassTraceTime::CLASS_CLINIT);
1313 call_class_initializer(THREAD);
1314 } else {
1315 // The elapsed time is so small it's not worth counting.
1316 if (UsePerfData) {
1317 ClassLoader::perf_classes_inited()->inc();
1318 }
1319 call_class_initializer(THREAD);
1320 }
1321 }
1322
1323 // Step 9
1324 if (!HAS_PENDING_EXCEPTION) {
1325 set_initialization_state_and_notify(fully_initialized, CHECK);
1326 debug_only(vtable().verify(tty, true);)
1327 }
1328 else {
1329 // Step 10 and 11
1330 Handle e(THREAD, PENDING_EXCEPTION);
1331 CLEAR_PENDING_EXCEPTION;
1332 // JVMTI has already reported the pending exception
1333 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1334 JvmtiExport::clear_detected_exception(jt);
1335 {
1336 EXCEPTION_MARK;
1337 add_initialization_error(THREAD, e);
1338 set_initialization_state_and_notify(initialization_error, THREAD);
1339 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1340 // JVMTI has already reported the pending exception
1341 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1342 JvmtiExport::clear_detected_exception(jt);
1343 }
1344 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1345 if (e->is_a(vmClasses::Error_klass())) {
1346 THROW_OOP(e());
1347 } else {
1348 JavaCallArguments args(e);
1349 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1350 vmSymbols::throwable_void_signature(),
1351 &args);
1352 }
1353 }
1354 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1355 }
1356
1357
1358 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1359 Handle h_init_lock(THREAD, init_lock());
1360 if (h_init_lock() != nullptr) {
1361 ObjectLocker ol(h_init_lock, THREAD);
1362 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1363 set_init_state(state);
1364 fence_and_clear_init_lock();
1365 ol.notify_all(CHECK);
1366 } else {
1367 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1368 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1369 set_init_state(state);
1370 }
1371 }
1372
1373 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1374 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1375 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1376 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1377
1378 DeoptimizationScope deopt_scope;
1379 {
1380 MutexLocker ml(current, Compile_lock);
1381
1382 set_init_state(InstanceKlass::loaded);
1383 // make sure init_state store is already done.
1384 // The compiler reads the hierarchy outside of the Compile_lock.
1385 // Access ordering is used to add to hierarchy.
1386
1387 // Link into hierarchy.
1388 append_to_sibling_list(); // add to superklass/sibling list
1389 process_interfaces(); // handle all "implements" declarations
1390
1391 // Now mark all code that depended on old class hierarchy.
1392 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1393 if (Universe::is_fully_initialized()) {
1394 CodeCache::mark_dependents_on(&deopt_scope, this);
1395 }
1396 }
1397 // Perform the deopt handshake outside Compile_lock.
1398 deopt_scope.deoptimize_marked();
1399 }
1400
1401
1402 InstanceKlass* InstanceKlass::implementor() const {
1403 InstanceKlass* volatile* ik = adr_implementor();
1404 if (ik == nullptr) {
1405 return nullptr;
1406 } else {
1407 // This load races with inserts, and therefore needs acquire.
1408 InstanceKlass* ikls = Atomic::load_acquire(ik);
1409 if (ikls != nullptr && !ikls->is_loader_alive()) {
1410 return nullptr; // don't return unloaded class
1411 } else {
1412 return ikls;
1413 }
1414 }
1415 }
1416
1417
1418 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1419 assert_locked_or_safepoint(Compile_lock);
1420 assert(is_interface(), "not interface");
1421 InstanceKlass* volatile* addr = adr_implementor();
1422 assert(addr != nullptr, "null addr");
1423 if (addr != nullptr) {
1424 Atomic::release_store(addr, ik);
1425 }
1426 }
1427
1428 int InstanceKlass::nof_implementors() const {
1429 InstanceKlass* ik = implementor();
1430 if (ik == nullptr) {
1431 return 0;
1432 } else if (ik != this) {
1433 return 1;
1434 } else {
1435 return 2;
1436 }
1437 }
1438
1439 // The embedded _implementor field can only record one implementor.
1440 // When there are more than one implementors, the _implementor field
1441 // is set to the interface Klass* itself. Following are the possible
1442 // values for the _implementor field:
1443 // null - no implementor
1444 // implementor Klass* - one implementor
1445 // self - more than one implementor
1446 //
1447 // The _implementor field only exists for interfaces.
1448 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1449 if (Universe::is_fully_initialized()) {
1450 assert_lock_strong(Compile_lock);
1451 }
1452 assert(is_interface(), "not interface");
1453 // Filter out my subinterfaces.
1454 // (Note: Interfaces are never on the subklass list.)
1455 if (ik->is_interface()) return;
1456
1457 // Filter out subclasses whose supers already implement me.
1458 // (Note: CHA must walk subclasses of direct implementors
1459 // in order to locate indirect implementors.)
1460 InstanceKlass* super_ik = ik->java_super();
1461 if (super_ik != nullptr && super_ik->implements_interface(this))
1462 // We only need to check one immediate superclass, since the
1463 // implements_interface query looks at transitive_interfaces.
1464 // Any supers of the super have the same (or fewer) transitive_interfaces.
1465 return;
1466
1467 InstanceKlass* iklass = implementor();
1468 if (iklass == nullptr) {
1469 set_implementor(ik);
1470 } else if (iklass != this && iklass != ik) {
1471 // There is already an implementor. Use itself as an indicator of
1472 // more than one implementors.
1473 set_implementor(this);
1474 }
1475
1476 // The implementor also implements the transitive_interfaces
1477 for (int index = 0; index < local_interfaces()->length(); index++) {
1478 local_interfaces()->at(index)->add_implementor(ik);
1479 }
1480 }
1481
1482 void InstanceKlass::init_implementor() {
1483 if (is_interface()) {
1484 set_implementor(nullptr);
1485 }
1486 }
1487
1488
1489 void InstanceKlass::process_interfaces() {
1490 // link this class into the implementors list of every interface it implements
1491 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1492 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1493 InstanceKlass* interf = local_interfaces()->at(i);
1494 assert(interf->is_interface(), "expected interface");
1495 interf->add_implementor(this);
1496 }
1497 }
1498
1499 bool InstanceKlass::can_be_primary_super_slow() const {
1500 if (is_interface())
1501 return false;
1502 else
1503 return Klass::can_be_primary_super_slow();
1504 }
1505
1506 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1507 Array<InstanceKlass*>* transitive_interfaces) {
1508 // The secondaries are the implemented interfaces.
1509 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1510 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1511 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1512 int num_secondaries = num_extra_slots + interfaces->length();
1513 if (num_secondaries == 0) {
1514 // Must share this for correct bootstrapping!
1515 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1516 return nullptr;
1517 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1518 // We will reuse the transitive interfaces list if we're certain
1519 // it's in hash order.
1520 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1521 set_secondary_supers(interfaces, bitmap);
1522 return nullptr;
1523 }
1524 // Copy transitive interfaces to a temporary growable array to be constructed
1525 // into the secondary super list with extra slots.
1526 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1527 for (int i = 0; i < interfaces->length(); i++) {
1528 secondaries->push(interfaces->at(i));
1529 }
1530 return secondaries;
1531 }
1532
1533 bool InstanceKlass::implements_interface(Klass* k) const {
1534 if (this == k) return true;
1535 assert(k->is_interface(), "should be an interface class");
1536 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1537 if (transitive_interfaces()->at(i) == k) {
1538 return true;
1539 }
1540 }
1541 return false;
1542 }
1543
1544 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1545 // Verify direct super interface
1546 if (this == k) return true;
1547 assert(k->is_interface(), "should be an interface class");
1548 for (int i = 0; i < local_interfaces()->length(); i++) {
1549 if (local_interfaces()->at(i) == k) {
1550 return true;
1551 }
1552 }
1553 return false;
1554 }
1555
1556 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1557 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1558 size_t size = objArrayOopDesc::object_size(length);
1559 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1560 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1561 /* do_zero */ true, CHECK_NULL);
1562 return o;
1563 }
1564
1565 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1566 if (TraceFinalizerRegistration) {
1567 tty->print("Registered ");
1568 i->print_value_on(tty);
1569 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1570 }
1571 instanceHandle h_i(THREAD, i);
1572 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1573 JavaValue result(T_VOID);
1574 JavaCallArguments args(h_i);
1575 methodHandle mh(THREAD, Universe::finalizer_register_method());
1576 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1577 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1578 return h_i();
1579 }
1580
1581 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1582 assert(!is_abstract() && !is_interface(), "Should not create this object");
1583 size_t size = size_helper(); // Query before forming handle.
1584 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1585 }
1586
1587 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1588 Klass* k = java_lang_Class::as_Klass(java_class);
1589 if (k == nullptr) {
1590 ResourceMark rm(THREAD);
1591 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1592 }
1593 InstanceKlass* ik = cast(k);
1594 ik->check_valid_for_instantiation(false, CHECK_NULL);
1595 ik->initialize(CHECK_NULL);
1596 return ik->allocate_instance(THREAD);
1597 }
1598
1599 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1600 return instanceHandle(THREAD, allocate_instance(THREAD));
1601 }
1602
1603 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1604 if (is_interface() || is_abstract()) {
1605 ResourceMark rm(THREAD);
1606 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1607 : vmSymbols::java_lang_InstantiationException(), external_name());
1608 }
1609 if (this == vmClasses::Class_klass()) {
1610 ResourceMark rm(THREAD);
1611 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1612 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1613 }
1614 }
1615
1616 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1617 // Need load-acquire for lock-free read
1618 if (array_klasses_acquire() == nullptr) {
1619
1620 // Recursively lock array allocation
1621 RecursiveLocker rl(MultiArray_lock, THREAD);
1622
1623 // Check if another thread created the array klass while we were waiting for the lock.
1624 if (array_klasses() == nullptr) {
1625 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1626 // use 'release' to pair with lock-free load
1627 release_set_array_klasses(k);
1628 }
1629 }
1630
1631 // array_klasses() will always be set at this point
1632 ObjArrayKlass* ak = array_klasses();
1633 assert(ak != nullptr, "should be set");
1634 return ak->array_klass(n, THREAD);
1635 }
1636
1637 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1638 // Need load-acquire for lock-free read
1639 ObjArrayKlass* oak = array_klasses_acquire();
1640 if (oak == nullptr) {
1641 return nullptr;
1642 } else {
1643 return oak->array_klass_or_null(n);
1644 }
1645 }
1646
1647 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1648 return array_klass(1, THREAD);
1649 }
1650
1651 ArrayKlass* InstanceKlass::array_klass_or_null() {
1652 return array_klass_or_null(1);
1653 }
1654
1655 static int call_class_initializer_counter = 0; // for debugging
1656
1657 Method* InstanceKlass::class_initializer() const {
1658 Method* clinit = find_method(
1659 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1660 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1661 return clinit;
1662 }
1663 return nullptr;
1664 }
1665
1666 void InstanceKlass::call_class_initializer(TRAPS) {
1667 if (ReplayCompiles &&
1668 (ReplaySuppressInitializers == 1 ||
1669 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1670 // Hide the existence of the initializer for the purpose of replaying the compile
1671 return;
1672 }
1673
1674 #if INCLUDE_CDS
1675 // This is needed to ensure the consistency of the archived heap objects.
1676 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1677 AOTClassInitializer::call_runtime_setup(THREAD, this);
1678 return;
1679 } else if (has_archived_enum_objs()) {
1680 assert(is_shared(), "must be");
1681 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1682 if (initialized) {
1683 return;
1684 }
1685 }
1686 #endif
1687
1688 methodHandle h_method(THREAD, class_initializer());
1689 assert(!is_initialized(), "we cannot initialize twice");
1690 LogTarget(Info, class, init) lt;
1691 if (lt.is_enabled()) {
1692 ResourceMark rm(THREAD);
1693 LogStream ls(lt);
1694 ls.print("%d Initializing ", call_class_initializer_counter++);
1695 name()->print_value_on(&ls);
1696 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1697 h_method() == nullptr ? "(no method)" : "", p2i(this),
1698 THREAD->name());
1699 }
1700 if (h_method() != nullptr) {
1701 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1702 JavaCallArguments args; // No arguments
1703 JavaValue result(T_VOID);
1704 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1705 }
1706 }
1707
1708 // If a class that implements this interface is initialized, is the JVM required
1709 // to first execute a <clinit> method declared in this interface,
1710 // or (if also_check_supers==true) any of the super types of this interface?
1711 //
1712 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1713 // an interface, then let SC be its superclass and let SI1, ..., SIn
1714 // be all superinterfaces of C (whether direct or indirect) that
1715 // declare at least one non-abstract, non-static method.
1716 //
1717 // So when an interface is initialized, it does not look at its
1718 // supers. But a proper class will ensure that all of its supers have
1719 // run their <clinit> methods, except that it disregards interfaces
1720 // that lack a non-static concrete method (i.e., a default method).
1721 // Therefore, you should probably call this method only when the
1722 // current class is a super of some proper class, not an interface.
1723 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1724 assert(is_interface(), "must be");
1725
1726 if (!has_nonstatic_concrete_methods()) {
1727 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1728 return false;
1729 }
1730
1731 // JVMS 5.5. Initialization
1732 // ...If C is an interface that declares a non-abstract,
1733 // non-static method, the initialization of a class that
1734 // implements C directly or indirectly.
1735 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1736 return true;
1737 }
1738 if (also_check_supers) {
1739 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1740 for (int i = 0; i < all_ifs->length(); ++i) {
1741 InstanceKlass* super_intf = all_ifs->at(i);
1742 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1743 return true;
1744 }
1745 }
1746 }
1747 return false;
1748 }
1749
1750 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1751 InterpreterOopMap* entry_for) {
1752 // Lazily create the _oop_map_cache at first request.
1753 // Load_acquire is needed to safely get instance published with CAS by another thread.
1754 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1755 if (oop_map_cache == nullptr) {
1756 // Try to install new instance atomically.
1757 oop_map_cache = new OopMapCache();
1758 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1759 if (other != nullptr) {
1760 // Someone else managed to install before us, ditch local copy and use the existing one.
1761 delete oop_map_cache;
1762 oop_map_cache = other;
1763 }
1764 }
1765 // _oop_map_cache is constant after init; lookup below does its own locking.
1766 oop_map_cache->lookup(method, bci, entry_for);
1767 }
1768
1769 bool InstanceKlass::contains_field_offset(int offset) {
1770 fieldDescriptor fd;
1771 return find_field_from_offset(offset, false, &fd);
1772 }
1773
1774 FieldInfo InstanceKlass::field(int index) const {
1775 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1776 if (fs.index() == index) {
1777 return fs.to_FieldInfo();
1778 }
1779 }
1780 fatal("Field not found");
1781 return FieldInfo();
1782 }
1783
1784 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1785 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1786 Symbol* f_name = fs.name();
1787 Symbol* f_sig = fs.signature();
1788 if (f_name == name && f_sig == sig) {
1789 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1790 return true;
1791 }
1792 }
1793 return false;
1794 }
1795
1796
1797 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1798 const int n = local_interfaces()->length();
1799 for (int i = 0; i < n; i++) {
1800 Klass* intf1 = local_interfaces()->at(i);
1801 assert(intf1->is_interface(), "just checking type");
1802 // search for field in current interface
1803 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1804 assert(fd->is_static(), "interface field must be static");
1805 return intf1;
1806 }
1807 // search for field in direct superinterfaces
1808 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1809 if (intf2 != nullptr) return intf2;
1810 }
1811 // otherwise field lookup fails
1812 return nullptr;
1813 }
1814
1815
1816 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1817 // search order according to newest JVM spec (5.4.3.2, p.167).
1818 // 1) search for field in current klass
1819 if (find_local_field(name, sig, fd)) {
1820 return const_cast<InstanceKlass*>(this);
1821 }
1822 // 2) search for field recursively in direct superinterfaces
1823 { Klass* intf = find_interface_field(name, sig, fd);
1824 if (intf != nullptr) return intf;
1825 }
1826 // 3) apply field lookup recursively if superclass exists
1827 { Klass* supr = super();
1828 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1829 }
1830 // 4) otherwise field lookup fails
1831 return nullptr;
1832 }
1833
1834
1835 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1836 // search order according to newest JVM spec (5.4.3.2, p.167).
1837 // 1) search for field in current klass
1838 if (find_local_field(name, sig, fd)) {
1839 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1840 }
1841 // 2) search for field recursively in direct superinterfaces
1842 if (is_static) {
1843 Klass* intf = find_interface_field(name, sig, fd);
1844 if (intf != nullptr) return intf;
1845 }
1846 // 3) apply field lookup recursively if superclass exists
1847 { Klass* supr = super();
1848 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1849 }
1850 // 4) otherwise field lookup fails
1851 return nullptr;
1852 }
1853
1854
1855 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1856 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1857 if (fs.offset() == offset) {
1858 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1859 if (fd->is_static() == is_static) return true;
1860 }
1861 }
1862 return false;
1863 }
1864
1865
1866 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1867 Klass* klass = const_cast<InstanceKlass*>(this);
1868 while (klass != nullptr) {
1869 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1870 return true;
1871 }
1872 klass = klass->super();
1873 }
1874 return false;
1875 }
1876
1877
1878 void InstanceKlass::methods_do(void f(Method* method)) {
1879 // Methods aren't stable until they are loaded. This can be read outside
1880 // a lock through the ClassLoaderData for profiling
1881 // Redefined scratch classes are on the list and need to be cleaned
1882 if (!is_loaded() && !is_scratch_class()) {
1883 return;
1884 }
1885
1886 int len = methods()->length();
1887 for (int index = 0; index < len; index++) {
1888 Method* m = methods()->at(index);
1889 assert(m->is_method(), "must be method");
1890 f(m);
1891 }
1892 }
1893
1894
1895 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1896 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1897 if (fs.access_flags().is_static()) {
1898 fieldDescriptor& fd = fs.field_descriptor();
1899 cl->do_field(&fd);
1900 }
1901 }
1902 }
1903
1904
1905 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1906 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1907 if (fs.access_flags().is_static()) {
1908 fieldDescriptor& fd = fs.field_descriptor();
1909 f(&fd, mirror, CHECK);
1910 }
1911 }
1912 }
1913
1914 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1915 InstanceKlass* super = superklass();
1916 if (super != nullptr) {
1917 super->do_nonstatic_fields(cl);
1918 }
1919 fieldDescriptor fd;
1920 int length = java_fields_count();
1921 for (int i = 0; i < length; i += 1) {
1922 fd.reinitialize(this, i);
1923 if (!fd.is_static()) {
1924 cl->do_field(&fd);
1925 }
1926 }
1927 }
1928
1929 // first in Pair is offset, second is index.
1930 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1931 return a->first - b->first;
1932 }
1933
1934 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1935 InstanceKlass* super = superklass();
1936 if (super != nullptr) {
1937 super->print_nonstatic_fields(cl);
1938 }
1939 ResourceMark rm;
1940 fieldDescriptor fd;
1941 // In DebugInfo nonstatic fields are sorted by offset.
1942 GrowableArray<Pair<int,int> > fields_sorted;
1943 int i = 0;
1944 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1945 if (!fs.access_flags().is_static()) {
1946 fd = fs.field_descriptor();
1947 Pair<int,int> f(fs.offset(), fs.index());
1948 fields_sorted.push(f);
1949 i++;
1950 }
1951 }
1952 if (i > 0) {
1953 int length = i;
1954 assert(length == fields_sorted.length(), "duh");
1955 fields_sorted.sort(compare_fields_by_offset);
1956 for (int i = 0; i < length; i++) {
1957 fd.reinitialize(this, fields_sorted.at(i).second);
1958 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1959 cl->do_field(&fd);
1960 }
1961 }
1962 }
1963
1964 #ifdef ASSERT
1965 static int linear_search(const Array<Method*>* methods,
1966 const Symbol* name,
1967 const Symbol* signature) {
1968 const int len = methods->length();
1969 for (int index = 0; index < len; index++) {
1970 const Method* const m = methods->at(index);
1971 assert(m->is_method(), "must be method");
1972 if (m->signature() == signature && m->name() == name) {
1973 return index;
1974 }
1975 }
1976 return -1;
1977 }
1978 #endif
1979
1980 bool InstanceKlass::_disable_method_binary_search = false;
1981
1982 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1983 int len = methods->length();
1984 int l = 0;
1985 int h = len - 1;
1986 while (l <= h) {
1987 Method* m = methods->at(l);
1988 if (m->name() == name) {
1989 return l;
1990 }
1991 l++;
1992 }
1993 return -1;
1994 }
1995
1996 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1997 if (_disable_method_binary_search) {
1998 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1999 // At the final stage of dynamic dumping, the methods array may not be sorted
2000 // by ascending addresses of their names, so we can't use binary search anymore.
2001 // However, methods with the same name are still laid out consecutively inside the
2002 // methods array, so let's look for the first one that matches.
2003 return linear_search(methods, name);
2004 }
2005
2006 int len = methods->length();
2007 int l = 0;
2008 int h = len - 1;
2009
2010 // methods are sorted by ascending addresses of their names, so do binary search
2011 while (l <= h) {
2012 int mid = (l + h) >> 1;
2013 Method* m = methods->at(mid);
2014 assert(m->is_method(), "must be method");
2015 int res = m->name()->fast_compare(name);
2016 if (res == 0) {
2017 return mid;
2018 } else if (res < 0) {
2019 l = mid + 1;
2020 } else {
2021 h = mid - 1;
2022 }
2023 }
2024 return -1;
2025 }
2026
2027 // find_method looks up the name/signature in the local methods array
2028 Method* InstanceKlass::find_method(const Symbol* name,
2029 const Symbol* signature) const {
2030 return find_method_impl(name, signature,
2031 OverpassLookupMode::find,
2032 StaticLookupMode::find,
2033 PrivateLookupMode::find);
2034 }
2035
2036 Method* InstanceKlass::find_method_impl(const Symbol* name,
2037 const Symbol* signature,
2038 OverpassLookupMode overpass_mode,
2039 StaticLookupMode static_mode,
2040 PrivateLookupMode private_mode) const {
2041 return InstanceKlass::find_method_impl(methods(),
2042 name,
2043 signature,
2044 overpass_mode,
2045 static_mode,
2046 private_mode);
2047 }
2048
2049 // find_instance_method looks up the name/signature in the local methods array
2050 // and skips over static methods
2051 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2052 const Symbol* name,
2053 const Symbol* signature,
2054 PrivateLookupMode private_mode) {
2055 Method* const meth = InstanceKlass::find_method_impl(methods,
2056 name,
2057 signature,
2058 OverpassLookupMode::find,
2059 StaticLookupMode::skip,
2060 private_mode);
2061 assert(((meth == nullptr) || !meth->is_static()),
2062 "find_instance_method should have skipped statics");
2063 return meth;
2064 }
2065
2066 // find_instance_method looks up the name/signature in the local methods array
2067 // and skips over static methods
2068 Method* InstanceKlass::find_instance_method(const Symbol* name,
2069 const Symbol* signature,
2070 PrivateLookupMode private_mode) const {
2071 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2072 }
2073
2074 // Find looks up the name/signature in the local methods array
2075 // and filters on the overpass, static and private flags
2076 // This returns the first one found
2077 // note that the local methods array can have up to one overpass, one static
2078 // and one instance (private or not) with the same name/signature
2079 Method* InstanceKlass::find_local_method(const Symbol* name,
2080 const Symbol* signature,
2081 OverpassLookupMode overpass_mode,
2082 StaticLookupMode static_mode,
2083 PrivateLookupMode private_mode) const {
2084 return InstanceKlass::find_method_impl(methods(),
2085 name,
2086 signature,
2087 overpass_mode,
2088 static_mode,
2089 private_mode);
2090 }
2091
2092 // Find looks up the name/signature in the local methods array
2093 // and filters on the overpass, static and private flags
2094 // This returns the first one found
2095 // note that the local methods array can have up to one overpass, one static
2096 // and one instance (private or not) with the same name/signature
2097 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2098 const Symbol* name,
2099 const Symbol* signature,
2100 OverpassLookupMode overpass_mode,
2101 StaticLookupMode static_mode,
2102 PrivateLookupMode private_mode) {
2103 return InstanceKlass::find_method_impl(methods,
2104 name,
2105 signature,
2106 overpass_mode,
2107 static_mode,
2108 private_mode);
2109 }
2110
2111 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2112 const Symbol* name,
2113 const Symbol* signature) {
2114 return InstanceKlass::find_method_impl(methods,
2115 name,
2116 signature,
2117 OverpassLookupMode::find,
2118 StaticLookupMode::find,
2119 PrivateLookupMode::find);
2120 }
2121
2122 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2123 const Symbol* name,
2124 const Symbol* signature,
2125 OverpassLookupMode overpass_mode,
2126 StaticLookupMode static_mode,
2127 PrivateLookupMode private_mode) {
2128 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2129 return hit >= 0 ? methods->at(hit): nullptr;
2130 }
2131
2132 // true if method matches signature and conforms to skipping_X conditions.
2133 static bool method_matches(const Method* m,
2134 const Symbol* signature,
2135 bool skipping_overpass,
2136 bool skipping_static,
2137 bool skipping_private) {
2138 return ((m->signature() == signature) &&
2139 (!skipping_overpass || !m->is_overpass()) &&
2140 (!skipping_static || !m->is_static()) &&
2141 (!skipping_private || !m->is_private()));
2142 }
2143
2144 // Used directly for default_methods to find the index into the
2145 // default_vtable_indices, and indirectly by find_method
2146 // find_method_index looks in the local methods array to return the index
2147 // of the matching name/signature. If, overpass methods are being ignored,
2148 // the search continues to find a potential non-overpass match. This capability
2149 // is important during method resolution to prefer a static method, for example,
2150 // over an overpass method.
2151 // There is the possibility in any _method's array to have the same name/signature
2152 // for a static method, an overpass method and a local instance method
2153 // To correctly catch a given method, the search criteria may need
2154 // to explicitly skip the other two. For local instance methods, it
2155 // is often necessary to skip private methods
2156 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2157 const Symbol* name,
2158 const Symbol* signature,
2159 OverpassLookupMode overpass_mode,
2160 StaticLookupMode static_mode,
2161 PrivateLookupMode private_mode) {
2162 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2163 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2164 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2165 const int hit = quick_search(methods, name);
2166 if (hit != -1) {
2167 const Method* const m = methods->at(hit);
2168
2169 // Do linear search to find matching signature. First, quick check
2170 // for common case, ignoring overpasses if requested.
2171 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2172 return hit;
2173 }
2174
2175 // search downwards through overloaded methods
2176 int i;
2177 for (i = hit - 1; i >= 0; --i) {
2178 const Method* const m = methods->at(i);
2179 assert(m->is_method(), "must be method");
2180 if (m->name() != name) {
2181 break;
2182 }
2183 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2184 return i;
2185 }
2186 }
2187 // search upwards
2188 for (i = hit + 1; i < methods->length(); ++i) {
2189 const Method* const m = methods->at(i);
2190 assert(m->is_method(), "must be method");
2191 if (m->name() != name) {
2192 break;
2193 }
2194 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2195 return i;
2196 }
2197 }
2198 // not found
2199 #ifdef ASSERT
2200 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2201 linear_search(methods, name, signature);
2202 assert(-1 == index, "binary search should have found entry %d", index);
2203 #endif
2204 }
2205 return -1;
2206 }
2207
2208 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2209 return find_method_by_name(methods(), name, end);
2210 }
2211
2212 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2213 const Symbol* name,
2214 int* end_ptr) {
2215 assert(end_ptr != nullptr, "just checking");
2216 int start = quick_search(methods, name);
2217 int end = start + 1;
2218 if (start != -1) {
2219 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2220 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2221 *end_ptr = end;
2222 return start;
2223 }
2224 return -1;
2225 }
2226
2227 // uncached_lookup_method searches both the local class methods array and all
2228 // superclasses methods arrays, skipping any overpass methods in superclasses,
2229 // and possibly skipping private methods.
2230 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2231 const Symbol* signature,
2232 OverpassLookupMode overpass_mode,
2233 PrivateLookupMode private_mode) const {
2234 OverpassLookupMode overpass_local_mode = overpass_mode;
2235 const Klass* klass = this;
2236 while (klass != nullptr) {
2237 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2238 signature,
2239 overpass_local_mode,
2240 StaticLookupMode::find,
2241 private_mode);
2242 if (method != nullptr) {
2243 return method;
2244 }
2245 klass = klass->super();
2246 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2247 }
2248 return nullptr;
2249 }
2250
2251 #ifdef ASSERT
2252 // search through class hierarchy and return true if this class or
2253 // one of the superclasses was redefined
2254 bool InstanceKlass::has_redefined_this_or_super() const {
2255 const Klass* klass = this;
2256 while (klass != nullptr) {
2257 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2258 return true;
2259 }
2260 klass = klass->super();
2261 }
2262 return false;
2263 }
2264 #endif
2265
2266 // lookup a method in the default methods list then in all transitive interfaces
2267 // Do NOT return private or static methods
2268 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2269 Symbol* signature) const {
2270 Method* m = nullptr;
2271 if (default_methods() != nullptr) {
2272 m = find_method(default_methods(), name, signature);
2273 }
2274 // Look up interfaces
2275 if (m == nullptr) {
2276 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2277 }
2278 return m;
2279 }
2280
2281 // lookup a method in all the interfaces that this class implements
2282 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2283 // They should only be found in the initial InterfaceMethodRef
2284 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2285 Symbol* signature,
2286 DefaultsLookupMode defaults_mode) const {
2287 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2288 int num_ifs = all_ifs->length();
2289 InstanceKlass *ik = nullptr;
2290 for (int i = 0; i < num_ifs; i++) {
2291 ik = all_ifs->at(i);
2292 Method* m = ik->lookup_method(name, signature);
2293 if (m != nullptr && m->is_public() && !m->is_static() &&
2294 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2295 return m;
2296 }
2297 }
2298 return nullptr;
2299 }
2300
2301 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2302 :_st(st), _verbose(verbose) {
2303 ResourceMark rm;
2304 _st->print("%-18s ", "KlassAddr");
2305 _st->print("%-4s ", "Size");
2306 _st->print("%-20s ", "State");
2307 _st->print("%-7s ", "Flags");
2308 _st->print("%-5s ", "ClassName");
2309 _st->cr();
2310 }
2311
2312 void PrintClassClosure::do_klass(Klass* k) {
2313 ResourceMark rm;
2314 // klass pointer
2315 _st->print(PTR_FORMAT " ", p2i(k));
2316 // klass size
2317 _st->print("%4d ", k->size());
2318 // initialization state
2319 if (k->is_instance_klass()) {
2320 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2321 } else {
2322 _st->print("%-20s ","");
2323 }
2324 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2325 char buf[10];
2326 int i = 0;
2327 if (k->has_finalizer()) buf[i++] = 'F';
2328 if (k->is_instance_klass()) {
2329 InstanceKlass* ik = InstanceKlass::cast(k);
2330 if (ik->has_final_method()) buf[i++] = 'f';
2331 if (ik->is_rewritten()) buf[i++] = 'W';
2332 if (ik->is_contended()) buf[i++] = 'C';
2333 if (ik->has_been_redefined()) buf[i++] = 'R';
2334 if (ik->is_shared()) buf[i++] = 'S';
2335 }
2336 buf[i++] = '\0';
2337 _st->print("%-7s ", buf);
2338 // klass name
2339 _st->print("%-5s ", k->external_name());
2340 // end
2341 _st->cr();
2342 if (_verbose) {
2343 k->print_on(_st);
2344 }
2345 }
2346
2347 /* jni_id_for for jfieldIds only */
2348 JNIid* InstanceKlass::jni_id_for(int offset) {
2349 MutexLocker ml(JfieldIdCreation_lock);
2350 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2351 if (probe == nullptr) {
2352 // Allocate new static field identifier
2353 probe = new JNIid(this, offset, jni_ids());
2354 set_jni_ids(probe);
2355 }
2356 return probe;
2357 }
2358
2359 u2 InstanceKlass::enclosing_method_data(int offset) const {
2360 const Array<jushort>* const inner_class_list = inner_classes();
2361 if (inner_class_list == nullptr) {
2362 return 0;
2363 }
2364 const int length = inner_class_list->length();
2365 if (length % inner_class_next_offset == 0) {
2366 return 0;
2367 }
2368 const int index = length - enclosing_method_attribute_size;
2369 assert(offset < enclosing_method_attribute_size, "invalid offset");
2370 return inner_class_list->at(index + offset);
2371 }
2372
2373 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2374 u2 method_index) {
2375 Array<jushort>* inner_class_list = inner_classes();
2376 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2377 int length = inner_class_list->length();
2378 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2379 int index = length - enclosing_method_attribute_size;
2380 inner_class_list->at_put(
2381 index + enclosing_method_class_index_offset, class_index);
2382 inner_class_list->at_put(
2383 index + enclosing_method_method_index_offset, method_index);
2384 }
2385 }
2386
2387 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2388 if (method->is_old() && !method->is_obsolete()) {
2389 // If the method passed in is old (but not obsolete), use the current version.
2390 method = method_with_idnum((int)idnum);
2391 assert(method != nullptr, "old and but not obsolete, so should exist");
2392 }
2393 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2394 Atomic::release_store(&jmeths[idnum + 1], new_id);
2395 return new_id;
2396 }
2397
2398 // Lookup or create a jmethodID.
2399 // This code is called by the VMThread and JavaThreads so the
2400 // locking has to be done very carefully to avoid deadlocks
2401 // and/or other cache consistency problems.
2402 //
2403 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2404 Method* method = method_h();
2405 int idnum = method->method_idnum();
2406 jmethodID* jmeths = methods_jmethod_ids_acquire();
2407
2408 // We use a double-check locking idiom here because this cache is
2409 // performance sensitive. In the normal system, this cache only
2410 // transitions from null to non-null which is safe because we use
2411 // release_set_methods_jmethod_ids() to advertise the new cache.
2412 // A partially constructed cache should never be seen by a racing
2413 // thread. We also use release_store() to save a new jmethodID
2414 // in the cache so a partially constructed jmethodID should never be
2415 // seen either. Cache reads of existing jmethodIDs proceed without a
2416 // lock, but cache writes of a new jmethodID requires uniqueness and
2417 // creation of the cache itself requires no leaks so a lock is
2418 // acquired in those two cases.
2419 //
2420 // If the RedefineClasses() API has been used, then this cache grows
2421 // in the redefinition safepoint.
2422
2423 if (jmeths == nullptr) {
2424 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2425 jmeths = methods_jmethod_ids_acquire();
2426 // Still null?
2427 if (jmeths == nullptr) {
2428 size_t size = idnum_allocated_count();
2429 assert(size > (size_t)idnum, "should already have space");
2430 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2431 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2432 // cache size is stored in element[0], other elements offset by one
2433 jmeths[0] = (jmethodID)size;
2434 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2435
2436 // publish jmeths
2437 release_set_methods_jmethod_ids(jmeths);
2438 return new_id;
2439 }
2440 }
2441
2442 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2443 if (id == nullptr) {
2444 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2445 id = jmeths[idnum + 1];
2446 // Still null?
2447 if (id == nullptr) {
2448 return update_jmethod_id(jmeths, method, idnum);
2449 }
2450 }
2451 return id;
2452 }
2453
2454 void InstanceKlass::update_methods_jmethod_cache() {
2455 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2456 jmethodID* cache = _methods_jmethod_ids;
2457 if (cache != nullptr) {
2458 size_t size = idnum_allocated_count();
2459 size_t old_size = (size_t)cache[0];
2460 if (old_size < size + 1) {
2461 // Allocate a larger one and copy entries to the new one.
2462 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2463 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2464 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2465 // The cache size is stored in element[0]; the other elements are offset by one.
2466 new_cache[0] = (jmethodID)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 // Figure out how many jmethodIDs haven't been allocated, and make
2478 // sure space for them is pre-allocated. This makes getting all
2479 // method ids much, much faster with classes with more than 8
2480 // methods, and has a *substantial* effect on performance with jvmti
2481 // code that loads all jmethodIDs for all classes.
2482 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2483 int new_jmeths = 0;
2484 int length = methods()->length();
2485 for (int index = start_offset; index < length; index++) {
2486 Method* m = methods()->at(index);
2487 jmethodID id = m->find_jmethod_id_or_null();
2488 if (id == nullptr) {
2489 new_jmeths++;
2490 }
2491 }
2492 if (new_jmeths != 0) {
2493 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2494 }
2495 }
2496
2497 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2498 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2499 int idnum = method->method_idnum();
2500 jmethodID* jmeths = methods_jmethod_ids_acquire();
2501 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2502 }
2503
2504 inline DependencyContext InstanceKlass::dependencies() {
2505 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2506 return dep_context;
2507 }
2508
2509 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2510 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2511 }
2512
2513 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2514 dependencies().add_dependent_nmethod(nm);
2515 }
2516
2517 void InstanceKlass::clean_dependency_context() {
2518 dependencies().clean_unloading_dependents();
2519 }
2520
2521 #ifndef PRODUCT
2522 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2523 dependencies().print_dependent_nmethods(verbose);
2524 }
2525
2526 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2527 return dependencies().is_dependent_nmethod(nm);
2528 }
2529 #endif //PRODUCT
2530
2531 void InstanceKlass::clean_weak_instanceklass_links() {
2532 clean_implementors_list();
2533 clean_method_data();
2534 }
2535
2536 void InstanceKlass::clean_implementors_list() {
2537 assert(is_loader_alive(), "this klass should be live");
2538 if (is_interface()) {
2539 assert (ClassUnloading, "only called for ClassUnloading");
2540 for (;;) {
2541 // Use load_acquire due to competing with inserts
2542 InstanceKlass* volatile* iklass = adr_implementor();
2543 assert(iklass != nullptr, "Klass must not be null");
2544 InstanceKlass* impl = Atomic::load_acquire(iklass);
2545 if (impl != nullptr && !impl->is_loader_alive()) {
2546 // null this field, might be an unloaded instance klass or null
2547 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2548 // Successfully unlinking implementor.
2549 if (log_is_enabled(Trace, class, unload)) {
2550 ResourceMark rm;
2551 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2552 }
2553 return;
2554 }
2555 } else {
2556 return;
2557 }
2558 }
2559 }
2560 }
2561
2562 void InstanceKlass::clean_method_data() {
2563 for (int m = 0; m < methods()->length(); m++) {
2564 MethodData* mdo = methods()->at(m)->method_data();
2565 if (mdo != nullptr) {
2566 mdo->clean_method_data(/*always_clean*/false);
2567 }
2568 }
2569 }
2570
2571 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2572 Klass::metaspace_pointers_do(it);
2573
2574 if (log_is_enabled(Trace, cds)) {
2575 ResourceMark rm;
2576 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2577 }
2578
2579 it->push(&_annotations);
2580 it->push((Klass**)&_array_klasses);
2581 if (!is_rewritten()) {
2582 it->push(&_constants, MetaspaceClosure::_writable);
2583 } else {
2584 it->push(&_constants);
2585 }
2586 it->push(&_inner_classes);
2587 #if INCLUDE_JVMTI
2588 it->push(&_previous_versions);
2589 #endif
2590 #if INCLUDE_CDS
2591 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2592 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2593 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2594 // The length check on the _methods is necessary because classes which don't have any
2595 // methods share the Universe::_the_empty_method_array which is in the RO region.
2596 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2597 // To handle jsr bytecode, new Method* maybe stored into _methods
2598 it->push(&_methods, MetaspaceClosure::_writable);
2599 } else {
2600 #endif
2601 it->push(&_methods);
2602 #if INCLUDE_CDS
2603 }
2604 #endif
2605 it->push(&_default_methods);
2606 it->push(&_local_interfaces);
2607 it->push(&_transitive_interfaces);
2608 it->push(&_method_ordering);
2609 if (!is_rewritten()) {
2610 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2611 } else {
2612 it->push(&_default_vtable_indices);
2613 }
2614
2615 it->push(&_fieldinfo_stream);
2616 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2617 it->push(&_fields_status, MetaspaceClosure::_writable);
2618
2619 if (itable_length() > 0) {
2620 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2621 int method_table_offset_in_words = ioe->offset()/wordSize;
2622 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2623
2624 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2625 / itableOffsetEntry::size();
2626
2627 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2628 if (ioe->interface_klass() != nullptr) {
2629 it->push(ioe->interface_klass_addr());
2630 itableMethodEntry* ime = ioe->first_method_entry(this);
2631 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2632 for (int index = 0; index < n; index ++) {
2633 it->push(ime[index].method_addr());
2634 }
2635 }
2636 }
2637 }
2638
2639 it->push(&_nest_host);
2640 it->push(&_nest_members);
2641 it->push(&_permitted_subclasses);
2642 it->push(&_record_components);
2643 }
2644
2645 #if INCLUDE_CDS
2646 void InstanceKlass::remove_unshareable_info() {
2647
2648 if (is_linked()) {
2649 assert(can_be_verified_at_dumptime(), "must be");
2650 // Remember this so we can avoid walking the hierarchy at runtime.
2651 set_verified_at_dump_time();
2652 }
2653
2654 Klass::remove_unshareable_info();
2655
2656 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2657 // Classes are attempted to link during dumping and may fail,
2658 // but these classes are still in the dictionary and class list in CLD.
2659 // If the class has failed verification, there is nothing else to remove.
2660 return;
2661 }
2662
2663 // Reset to the 'allocated' state to prevent any premature accessing to
2664 // a shared class at runtime while the class is still being loaded and
2665 // restored. A class' init_state is set to 'loaded' at runtime when it's
2666 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2667 _init_state = allocated;
2668
2669 { // Otherwise this needs to take out the Compile_lock.
2670 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2671 init_implementor();
2672 }
2673
2674 // Call remove_unshareable_info() on other objects that belong to this class, except
2675 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2676 // ArchiveBuilder::make_klasses_shareable(),
2677
2678 for (int i = 0; i < methods()->length(); i++) {
2679 Method* m = methods()->at(i);
2680 m->remove_unshareable_info();
2681 }
2682
2683 // do array classes also.
2684 if (array_klasses() != nullptr) {
2685 array_klasses()->remove_unshareable_info();
2686 }
2687
2688 // These are not allocated from metaspace. They are safe to set to null.
2689 _source_debug_extension = nullptr;
2690 _dep_context = nullptr;
2691 _osr_nmethods_head = nullptr;
2692 #if INCLUDE_JVMTI
2693 _breakpoints = nullptr;
2694 _previous_versions = nullptr;
2695 _cached_class_file = nullptr;
2696 _jvmti_cached_class_field_map = nullptr;
2697 #endif
2698
2699 _init_thread = nullptr;
2700 _methods_jmethod_ids = nullptr;
2701 _jni_ids = nullptr;
2702 _oop_map_cache = nullptr;
2703 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2704 // keep _nest_host
2705 } else {
2706 // clear _nest_host to ensure re-load at runtime
2707 _nest_host = nullptr;
2708 }
2709 init_shared_package_entry();
2710 _dep_context_last_cleaned = 0;
2711 DEBUG_ONLY(_shared_class_load_count = 0);
2712
2713 remove_unshareable_flags();
2714 }
2715
2716 void InstanceKlass::remove_unshareable_flags() {
2717 // clear all the flags/stats that shouldn't be in the archived version
2718 assert(!is_scratch_class(), "must be");
2719 assert(!has_been_redefined(), "must be");
2720 #if INCLUDE_JVMTI
2721 set_is_being_redefined(false);
2722 #endif
2723 set_has_resolved_methods(false);
2724 }
2725
2726 void InstanceKlass::remove_java_mirror() {
2727 Klass::remove_java_mirror();
2728
2729 // do array classes also.
2730 if (array_klasses() != nullptr) {
2731 array_klasses()->remove_java_mirror();
2732 }
2733 }
2734
2735 void InstanceKlass::init_shared_package_entry() {
2736 assert(CDSConfig::is_dumping_archive(), "must be");
2737 #if !INCLUDE_CDS_JAVA_HEAP
2738 _package_entry = nullptr;
2739 #else
2740 if (CDSConfig::is_dumping_full_module_graph()) {
2741 if (is_shared_unregistered_class()) {
2742 _package_entry = nullptr;
2743 } else {
2744 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2745 }
2746 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2747 CDSConfig::is_using_full_module_graph() &&
2748 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2749 // _package_entry is an archived package in the base archive. Leave it as is.
2750 } else {
2751 _package_entry = nullptr;
2752 }
2753 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2754 #endif
2755 }
2756
2757 void InstanceKlass::compute_has_loops_flag_for_methods() {
2758 Array<Method*>* methods = this->methods();
2759 for (int index = 0; index < methods->length(); ++index) {
2760 Method* m = methods->at(index);
2761 if (!m->is_overpass()) { // work around JDK-8305771
2762 m->compute_has_loops_flag();
2763 }
2764 }
2765 }
2766
2767 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2768 PackageEntry* pkg_entry, TRAPS) {
2769 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2770 // before the InstanceKlass is added to the SystemDictionary. Make
2771 // sure the current state is <loaded.
2772 assert(!is_loaded(), "invalid init state");
2773 assert(!shared_loading_failed(), "Must not try to load failed class again");
2774 set_package(loader_data, pkg_entry, CHECK);
2775 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2776
2777 Array<Method*>* methods = this->methods();
2778 int num_methods = methods->length();
2779 for (int index = 0; index < num_methods; ++index) {
2780 methods->at(index)->restore_unshareable_info(CHECK);
2781 }
2782 #if INCLUDE_JVMTI
2783 if (JvmtiExport::has_redefined_a_class()) {
2784 // Reinitialize vtable because RedefineClasses may have changed some
2785 // entries in this vtable for super classes so the CDS vtable might
2786 // point to old or obsolete entries. RedefineClasses doesn't fix up
2787 // vtables in the shared system dictionary, only the main one.
2788 // It also redefines the itable too so fix that too.
2789 // First fix any default methods that point to a super class that may
2790 // have been redefined.
2791 bool trace_name_printed = false;
2792 adjust_default_methods(&trace_name_printed);
2793 if (verified_at_dump_time()) {
2794 // Initialize vtable and itable for classes which can be verified at dump time.
2795 // Unlinked classes such as old classes with major version < 50 cannot be verified
2796 // at dump time.
2797 vtable().initialize_vtable();
2798 itable().initialize_itable();
2799 }
2800 }
2801 #endif // INCLUDE_JVMTI
2802
2803 // restore constant pool resolved references
2804 constants()->restore_unshareable_info(CHECK);
2805
2806 if (array_klasses() != nullptr) {
2807 // To get a consistent list of classes we need MultiArray_lock to ensure
2808 // array classes aren't observed while they are being restored.
2809 RecursiveLocker rl(MultiArray_lock, THREAD);
2810 assert(this == array_klasses()->bottom_klass(), "sanity");
2811 // Array classes have null protection domain.
2812 // --> see ArrayKlass::complete_create_array_klass()
2813 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2814 }
2815
2816 // Initialize @ValueBased class annotation if not already set in the archived klass.
2817 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2818 set_is_value_based();
2819 }
2820 }
2821
2822 // Check if a class or any of its supertypes has a version older than 50.
2823 // CDS will not perform verification of old classes during dump time because
2824 // without changing the old verifier, the verification constraint cannot be
2825 // retrieved during dump time.
2826 // Verification of archived old classes will be performed during run time.
2827 bool InstanceKlass::can_be_verified_at_dumptime() const {
2828 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2829 // This is a class that was dumped into the base archive, so we know
2830 // it was verified at dump time.
2831 return true;
2832 }
2833 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2834 return false;
2835 }
2836 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2837 return false;
2838 }
2839 Array<InstanceKlass*>* interfaces = local_interfaces();
2840 int len = interfaces->length();
2841 for (int i = 0; i < len; i++) {
2842 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2843 return false;
2844 }
2845 }
2846 return true;
2847 }
2848
2849 int InstanceKlass::shared_class_loader_type() const {
2850 if (is_shared_boot_class()) {
2851 return ClassLoader::BOOT_LOADER;
2852 } else if (is_shared_platform_class()) {
2853 return ClassLoader::PLATFORM_LOADER;
2854 } else if (is_shared_app_class()) {
2855 return ClassLoader::APP_LOADER;
2856 } else {
2857 return ClassLoader::OTHER;
2858 }
2859 }
2860 #endif // INCLUDE_CDS
2861
2862 #if INCLUDE_JVMTI
2863 static void clear_all_breakpoints(Method* m) {
2864 m->clear_all_breakpoints();
2865 }
2866 #endif
2867
2868 void InstanceKlass::unload_class(InstanceKlass* ik) {
2869
2870 if (ik->is_scratch_class()) {
2871 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2872 return;
2873 }
2874 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2875
2876 // Release dependencies.
2877 ik->dependencies().remove_all_dependents();
2878
2879 // notify the debugger
2880 if (JvmtiExport::should_post_class_unload()) {
2881 JvmtiExport::post_class_unload(ik);
2882 }
2883
2884 // notify ClassLoadingService of class unload
2885 ClassLoadingService::notify_class_unloaded(ik);
2886
2887 SystemDictionaryShared::handle_class_unloading(ik);
2888
2889 if (log_is_enabled(Info, class, unload)) {
2890 ResourceMark rm;
2891 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2892 }
2893
2894 Events::log_class_unloading(Thread::current(), ik);
2895
2896 #if INCLUDE_JFR
2897 assert(ik != nullptr, "invariant");
2898 EventClassUnload event;
2899 event.set_unloadedClass(ik);
2900 event.set_definingClassLoader(ik->class_loader_data());
2901 event.commit();
2902 #endif
2903 }
2904
2905 static void method_release_C_heap_structures(Method* m) {
2906 m->release_C_heap_structures();
2907 }
2908
2909 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2910 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2911 // Clean up C heap
2912 Klass::release_C_heap_structures();
2913
2914 // Deallocate and call destructors for MDO mutexes
2915 if (release_sub_metadata) {
2916 methods_do(method_release_C_heap_structures);
2917 }
2918
2919 // Deallocate oop map cache
2920 if (_oop_map_cache != nullptr) {
2921 delete _oop_map_cache;
2922 _oop_map_cache = nullptr;
2923 }
2924
2925 // Deallocate JNI identifiers for jfieldIDs
2926 JNIid::deallocate(jni_ids());
2927 set_jni_ids(nullptr);
2928
2929 jmethodID* jmeths = methods_jmethod_ids_acquire();
2930 if (jmeths != nullptr) {
2931 release_set_methods_jmethod_ids(nullptr);
2932 FreeHeap(jmeths);
2933 }
2934
2935 assert(_dep_context == nullptr,
2936 "dependencies should already be cleaned");
2937
2938 #if INCLUDE_JVMTI
2939 // Deallocate breakpoint records
2940 if (breakpoints() != nullptr) {
2941 methods_do(clear_all_breakpoints);
2942 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2943 }
2944
2945 // deallocate the cached class file
2946 if (_cached_class_file != nullptr) {
2947 os::free(_cached_class_file);
2948 _cached_class_file = nullptr;
2949 }
2950 #endif
2951
2952 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2953
2954 if (release_sub_metadata) {
2955 constants()->release_C_heap_structures();
2956 }
2957 }
2958
2959 // The constant pool is on stack if any of the methods are executing or
2960 // referenced by handles.
2961 bool InstanceKlass::on_stack() const {
2962 return _constants->on_stack();
2963 }
2964
2965 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2966 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2967 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2968
2969 // minor and major version numbers of class file
2970 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2971 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2972 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2973 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2974
2975 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2976 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2977 if (ik->constants()->version() == version) {
2978 return ik;
2979 }
2980 }
2981 return nullptr;
2982 }
2983
2984 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2985 if (array == nullptr) {
2986 _source_debug_extension = nullptr;
2987 } else {
2988 // Adding one to the attribute length in order to store a null terminator
2989 // character could cause an overflow because the attribute length is
2990 // already coded with an u4 in the classfile, but in practice, it's
2991 // unlikely to happen.
2992 assert((length+1) > length, "Overflow checking");
2993 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2994 for (int i = 0; i < length; i++) {
2995 sde[i] = array[i];
2996 }
2997 sde[length] = '\0';
2998 _source_debug_extension = sde;
2999 }
3000 }
3001
3002 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3003 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3004 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3005
3006 const char* InstanceKlass::signature_name() const {
3007
3008 // Get the internal name as a c string
3009 const char* src = (const char*) (name()->as_C_string());
3010 const int src_length = (int)strlen(src);
3011
3012 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3013
3014 // Add L as type indicator
3015 int dest_index = 0;
3016 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3017
3018 // Add the actual class name
3019 for (int src_index = 0; src_index < src_length; ) {
3020 dest[dest_index++] = src[src_index++];
3021 }
3022
3023 if (is_hidden()) { // Replace the last '+' with a '.'.
3024 for (int index = (int)src_length; index > 0; index--) {
3025 if (dest[index] == '+') {
3026 dest[index] = JVM_SIGNATURE_DOT;
3027 break;
3028 }
3029 }
3030 }
3031
3032 // Add the semicolon and the null
3033 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3034 dest[dest_index] = '\0';
3035 return dest;
3036 }
3037
3038 ModuleEntry* InstanceKlass::module() const {
3039 if (is_hidden() &&
3040 in_unnamed_package() &&
3041 class_loader_data()->has_class_mirror_holder()) {
3042 // For a non-strong hidden class defined to an unnamed package,
3043 // its (class held) CLD will not have an unnamed module created for it.
3044 // Two choices to find the correct ModuleEntry:
3045 // 1. If hidden class is within a nest, use nest host's module
3046 // 2. Find the unnamed module off from the class loader
3047 // For now option #2 is used since a nest host is not set until
3048 // after the instance class is created in jvm_lookup_define_class().
3049 if (class_loader_data()->is_boot_class_loader_data()) {
3050 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3051 } else {
3052 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3053 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3054 return java_lang_Module::module_entry(module);
3055 }
3056 }
3057
3058 // Class is in a named package
3059 if (!in_unnamed_package()) {
3060 return _package_entry->module();
3061 }
3062
3063 // Class is in an unnamed package, return its loader's unnamed module
3064 return class_loader_data()->unnamed_module();
3065 }
3066
3067 bool InstanceKlass::in_javabase_module() const {
3068 return module()->name() == vmSymbols::java_base();
3069 }
3070
3071 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3072
3073 // ensure java/ packages only loaded by boot or platform builtin loaders
3074 // not needed for shared class since CDS does not archive prohibited classes.
3075 if (!is_shared()) {
3076 check_prohibited_package(name(), loader_data, CHECK);
3077 }
3078
3079 if (is_shared() && _package_entry != nullptr) {
3080 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3081 // we can use the saved package
3082 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3083 return;
3084 } else {
3085 _package_entry = nullptr;
3086 }
3087 }
3088
3089 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3090 // it returns, so we need to decrement it when the current function exits.
3091 TempNewSymbol from_class_name =
3092 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3093
3094 Symbol* pkg_name;
3095 if (pkg_entry != nullptr) {
3096 pkg_name = pkg_entry->name();
3097 } else {
3098 pkg_name = from_class_name;
3099 }
3100
3101 if (pkg_name != nullptr && loader_data != nullptr) {
3102
3103 // Find in class loader's package entry table.
3104 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3105
3106 // If the package name is not found in the loader's package
3107 // entry table, it is an indication that the package has not
3108 // been defined. Consider it defined within the unnamed module.
3109 if (_package_entry == nullptr) {
3110
3111 if (!ModuleEntryTable::javabase_defined()) {
3112 // Before java.base is defined during bootstrapping, define all packages in
3113 // the java.base module. If a non-java.base package is erroneously placed
3114 // in the java.base module it will be caught later when java.base
3115 // is defined by ModuleEntryTable::verify_javabase_packages check.
3116 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3117 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3118 } else {
3119 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3120 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3121 }
3122
3123 // A package should have been successfully created
3124 DEBUG_ONLY(ResourceMark rm(THREAD));
3125 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3126 name()->as_C_string(), loader_data->loader_name_and_id());
3127 }
3128
3129 if (log_is_enabled(Debug, module)) {
3130 ResourceMark rm(THREAD);
3131 ModuleEntry* m = _package_entry->module();
3132 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3133 external_name(),
3134 pkg_name->as_C_string(),
3135 loader_data->loader_name_and_id(),
3136 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3137 }
3138 } else {
3139 ResourceMark rm(THREAD);
3140 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3141 external_name(),
3142 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3143 UNNAMED_MODULE);
3144 }
3145 }
3146
3147 // Function set_classpath_index ensures that for a non-null _package_entry
3148 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3149 // It then sets the classpath_index in the package entry record.
3150 //
3151 // The classpath_index field is used to find the entry on the boot loader class
3152 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3153 // in an unnamed module. It is also used to indicate (for all packages whose
3154 // classes are loaded by the boot loader) that at least one of the package's
3155 // classes has been loaded.
3156 void InstanceKlass::set_classpath_index(s2 path_index) {
3157 if (_package_entry != nullptr) {
3158 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3159 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3160 assert(path_index != -1, "Unexpected classpath_index");
3161 _package_entry->set_classpath_index(path_index);
3162 }
3163 }
3164
3165 // different versions of is_same_class_package
3166
3167 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3168 oop classloader1 = this->class_loader();
3169 PackageEntry* classpkg1 = this->package();
3170 if (class2->is_objArray_klass()) {
3171 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3172 }
3173
3174 oop classloader2;
3175 PackageEntry* classpkg2;
3176 if (class2->is_instance_klass()) {
3177 classloader2 = class2->class_loader();
3178 classpkg2 = class2->package();
3179 } else {
3180 assert(class2->is_typeArray_klass(), "should be type array");
3181 classloader2 = nullptr;
3182 classpkg2 = nullptr;
3183 }
3184
3185 // Same package is determined by comparing class loader
3186 // and package entries. Both must be the same. This rule
3187 // applies even to classes that are defined in the unnamed
3188 // package, they still must have the same class loader.
3189 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3190 return true;
3191 }
3192
3193 return false;
3194 }
3195
3196 // return true if this class and other_class are in the same package. Classloader
3197 // and classname information is enough to determine a class's package
3198 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3199 const Symbol* other_class_name) const {
3200 if (class_loader() != other_class_loader) {
3201 return false;
3202 }
3203 if (name()->fast_compare(other_class_name) == 0) {
3204 return true;
3205 }
3206
3207 {
3208 ResourceMark rm;
3209
3210 bool bad_class_name = false;
3211 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3212 if (bad_class_name) {
3213 return false;
3214 }
3215 // Check that package_from_class_name() returns null, not "", if there is no package.
3216 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3217
3218 const Symbol* const this_package_name =
3219 this->package() != nullptr ? this->package()->name() : nullptr;
3220
3221 if (this_package_name == nullptr || other_pkg == nullptr) {
3222 // One of the two doesn't have a package. Only return true if the other
3223 // one also doesn't have a package.
3224 return this_package_name == other_pkg;
3225 }
3226
3227 // Check if package is identical
3228 return this_package_name->fast_compare(other_pkg) == 0;
3229 }
3230 }
3231
3232 static bool is_prohibited_package_slow(Symbol* class_name) {
3233 // Caller has ResourceMark
3234 int length;
3235 jchar* unicode = class_name->as_unicode(length);
3236 return (length >= 5 &&
3237 unicode[0] == 'j' &&
3238 unicode[1] == 'a' &&
3239 unicode[2] == 'v' &&
3240 unicode[3] == 'a' &&
3241 unicode[4] == '/');
3242 }
3243
3244 // Only boot and platform class loaders can define classes in "java/" packages.
3245 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3246 ClassLoaderData* loader_data,
3247 TRAPS) {
3248 if (!loader_data->is_boot_class_loader_data() &&
3249 !loader_data->is_platform_class_loader_data() &&
3250 class_name != nullptr && class_name->utf8_length() >= 5) {
3251 ResourceMark rm(THREAD);
3252 bool prohibited;
3253 const u1* base = class_name->base();
3254 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3255 prohibited = is_prohibited_package_slow(class_name);
3256 } else {
3257 char* name = class_name->as_C_string();
3258 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3259 }
3260 if (prohibited) {
3261 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3262 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3263 char* name = pkg_name->as_C_string();
3264 const char* class_loader_name = loader_data->loader_name_and_id();
3265 StringUtils::replace_no_expand(name, "/", ".");
3266 const char* msg_text1 = "Class loader (instance of): ";
3267 const char* msg_text2 = " tried to load prohibited package name: ";
3268 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3269 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3270 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3271 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3272 }
3273 }
3274 return;
3275 }
3276
3277 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3278 constantPoolHandle i_cp(THREAD, constants());
3279 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3280 int ioff = iter.inner_class_info_index();
3281 if (ioff != 0) {
3282 // Check to see if the name matches the class we're looking for
3283 // before attempting to find the class.
3284 if (i_cp->klass_name_at_matches(this, ioff)) {
3285 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3286 if (this == inner_klass) {
3287 *ooff = iter.outer_class_info_index();
3288 *noff = iter.inner_name_index();
3289 return true;
3290 }
3291 }
3292 }
3293 }
3294 return false;
3295 }
3296
3297 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3298 InstanceKlass* outer_klass = nullptr;
3299 *inner_is_member = false;
3300 int ooff = 0, noff = 0;
3301 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3302 if (has_inner_classes_attr) {
3303 constantPoolHandle i_cp(THREAD, constants());
3304 if (ooff != 0) {
3305 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3306 if (!ok->is_instance_klass()) {
3307 // If the outer class is not an instance klass then it cannot have
3308 // declared any inner classes.
3309 ResourceMark rm(THREAD);
3310 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3311 Exceptions::fthrow(
3312 THREAD_AND_LOCATION,
3313 vmSymbols::java_lang_IncompatibleClassChangeError(),
3314 "%s and %s disagree on InnerClasses attribute",
3315 ok->external_name(),
3316 external_name());
3317 return nullptr;
3318 }
3319 outer_klass = InstanceKlass::cast(ok);
3320 *inner_is_member = true;
3321 }
3322 if (nullptr == outer_klass) {
3323 // It may be a local class; try for that.
3324 int encl_method_class_idx = enclosing_method_class_index();
3325 if (encl_method_class_idx != 0) {
3326 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3327 outer_klass = InstanceKlass::cast(ok);
3328 *inner_is_member = false;
3329 }
3330 }
3331 }
3332
3333 // If no inner class attribute found for this class.
3334 if (nullptr == outer_klass) return nullptr;
3335
3336 // Throws an exception if outer klass has not declared k as an inner klass
3337 // We need evidence that each klass knows about the other, or else
3338 // the system could allow a spoof of an inner class to gain access rights.
3339 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3340 return outer_klass;
3341 }
3342
3343 u2 InstanceKlass::compute_modifier_flags() const {
3344 u2 access = access_flags().as_unsigned_short();
3345
3346 // But check if it happens to be member class.
3347 InnerClassesIterator iter(this);
3348 for (; !iter.done(); iter.next()) {
3349 int ioff = iter.inner_class_info_index();
3350 // Inner class attribute can be zero, skip it.
3351 // Strange but true: JVM spec. allows null inner class refs.
3352 if (ioff == 0) continue;
3353
3354 // only look at classes that are already loaded
3355 // since we are looking for the flags for our self.
3356 Symbol* inner_name = constants()->klass_name_at(ioff);
3357 if (name() == inner_name) {
3358 // This is really a member class.
3359 access = iter.inner_access_flags();
3360 break;
3361 }
3362 }
3363 // Remember to strip ACC_SUPER bit
3364 return (access & (~JVM_ACC_SUPER));
3365 }
3366
3367 jint InstanceKlass::jvmti_class_status() const {
3368 jint result = 0;
3369
3370 if (is_linked()) {
3371 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3372 }
3373
3374 if (is_initialized()) {
3375 assert(is_linked(), "Class status is not consistent");
3376 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3377 }
3378 if (is_in_error_state()) {
3379 result |= JVMTI_CLASS_STATUS_ERROR;
3380 }
3381 return result;
3382 }
3383
3384 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3385 bool implements_interface; // initialized by method_at_itable_or_null
3386 Method* m = method_at_itable_or_null(holder, index,
3387 implements_interface); // out parameter
3388 if (m != nullptr) {
3389 assert(implements_interface, "sanity");
3390 return m;
3391 } else if (implements_interface) {
3392 // Throw AbstractMethodError since corresponding itable slot is empty.
3393 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3394 } else {
3395 // If the interface isn't implemented by the receiver class,
3396 // the VM should throw IncompatibleClassChangeError.
3397 ResourceMark rm(THREAD);
3398 stringStream ss;
3399 bool same_module = (module() == holder->module());
3400 ss.print("Receiver class %s does not implement "
3401 "the interface %s defining the method to be called "
3402 "(%s%s%s)",
3403 external_name(), holder->external_name(),
3404 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3405 (same_module) ? "" : "; ",
3406 (same_module) ? "" : holder->class_in_module_of_loader());
3407 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3408 }
3409 }
3410
3411 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3412 klassItable itable(this);
3413 for (int i = 0; i < itable.size_offset_table(); i++) {
3414 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3415 if (offset_entry->interface_klass() == holder) {
3416 implements_interface = true;
3417 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3418 Method* m = ime[index].method();
3419 return m;
3420 }
3421 }
3422 implements_interface = false;
3423 return nullptr; // offset entry not found
3424 }
3425
3426 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3427 assert(is_linked(), "required");
3428 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3429 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3430
3431 int vtable_index = Method::invalid_vtable_index;
3432 Symbol* name = intf_method->name();
3433 Symbol* signature = intf_method->signature();
3434
3435 // First check in default method array
3436 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3437 int index = find_method_index(default_methods(),
3438 name, signature,
3439 Klass::OverpassLookupMode::find,
3440 Klass::StaticLookupMode::find,
3441 Klass::PrivateLookupMode::find);
3442 if (index >= 0) {
3443 vtable_index = default_vtable_indices()->at(index);
3444 }
3445 }
3446 if (vtable_index == Method::invalid_vtable_index) {
3447 // get vtable_index for miranda methods
3448 klassVtable vt = vtable();
3449 vtable_index = vt.index_of_miranda(name, signature);
3450 }
3451 return vtable_index;
3452 }
3453
3454 #if INCLUDE_JVMTI
3455 // update default_methods for redefineclasses for methods that are
3456 // not yet in the vtable due to concurrent subclass define and superinterface
3457 // redefinition
3458 // Note: those in the vtable, should have been updated via adjust_method_entries
3459 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3460 // search the default_methods for uses of either obsolete or EMCP methods
3461 if (default_methods() != nullptr) {
3462 for (int index = 0; index < default_methods()->length(); index ++) {
3463 Method* old_method = default_methods()->at(index);
3464 if (old_method == nullptr || !old_method->is_old()) {
3465 continue; // skip uninteresting entries
3466 }
3467 assert(!old_method->is_deleted(), "default methods may not be deleted");
3468 Method* new_method = old_method->get_new_method();
3469 default_methods()->at_put(index, new_method);
3470
3471 if (log_is_enabled(Info, redefine, class, update)) {
3472 ResourceMark rm;
3473 if (!(*trace_name_printed)) {
3474 log_info(redefine, class, update)
3475 ("adjust: klassname=%s default methods from name=%s",
3476 external_name(), old_method->method_holder()->external_name());
3477 *trace_name_printed = true;
3478 }
3479 log_debug(redefine, class, update, vtables)
3480 ("default method update: %s(%s) ",
3481 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3482 }
3483 }
3484 }
3485 }
3486 #endif // INCLUDE_JVMTI
3487
3488 // On-stack replacement stuff
3489 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3490 assert_lock_strong(NMethodState_lock);
3491 #ifndef PRODUCT
3492 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3493 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3494 "redundant OSR recompilation detected. memory leak in CodeCache!");
3495 #endif
3496 // only one compilation can be active
3497 assert(n->is_osr_method(), "wrong kind of nmethod");
3498 n->set_osr_link(osr_nmethods_head());
3499 set_osr_nmethods_head(n);
3500 // Raise the highest osr level if necessary
3501 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3502
3503 // Get rid of the osr methods for the same bci that have lower levels.
3504 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3505 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3506 if (inv != nullptr && inv->is_in_use()) {
3507 inv->make_not_entrant("OSR invalidation of lower levels");
3508 }
3509 }
3510 }
3511
3512 // Remove osr nmethod from the list. Return true if found and removed.
3513 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3514 // This is a short non-blocking critical region, so the no safepoint check is ok.
3515 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3516 assert(n->is_osr_method(), "wrong kind of nmethod");
3517 nmethod* last = nullptr;
3518 nmethod* cur = osr_nmethods_head();
3519 int max_level = CompLevel_none; // Find the max comp level excluding n
3520 Method* m = n->method();
3521 // Search for match
3522 bool found = false;
3523 while(cur != nullptr && cur != n) {
3524 if (m == cur->method()) {
3525 // Find max level before n
3526 max_level = MAX2(max_level, cur->comp_level());
3527 }
3528 last = cur;
3529 cur = cur->osr_link();
3530 }
3531 nmethod* next = nullptr;
3532 if (cur == n) {
3533 found = true;
3534 next = cur->osr_link();
3535 if (last == nullptr) {
3536 // Remove first element
3537 set_osr_nmethods_head(next);
3538 } else {
3539 last->set_osr_link(next);
3540 }
3541 }
3542 n->set_osr_link(nullptr);
3543 cur = next;
3544 while (cur != nullptr) {
3545 // Find max level after n
3546 if (m == cur->method()) {
3547 max_level = MAX2(max_level, cur->comp_level());
3548 }
3549 cur = cur->osr_link();
3550 }
3551 m->set_highest_osr_comp_level(max_level);
3552 return found;
3553 }
3554
3555 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3556 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3557 nmethod* osr = osr_nmethods_head();
3558 int found = 0;
3559 while (osr != nullptr) {
3560 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3561 if (osr->method() == m) {
3562 deopt_scope->mark(osr);
3563 found++;
3564 }
3565 osr = osr->osr_link();
3566 }
3567 return found;
3568 }
3569
3570 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3571 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3572 nmethod* osr = osr_nmethods_head();
3573 nmethod* best = nullptr;
3574 while (osr != nullptr) {
3575 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3576 // There can be a time when a c1 osr method exists but we are waiting
3577 // for a c2 version. When c2 completes its osr nmethod we will trash
3578 // the c1 version and only be able to find the c2 version. However
3579 // while we overflow in the c1 code at back branches we don't want to
3580 // try and switch to the same code as we are already running
3581
3582 if (osr->method() == m &&
3583 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3584 if (match_level) {
3585 if (osr->comp_level() == comp_level) {
3586 // Found a match - return it.
3587 return osr;
3588 }
3589 } else {
3590 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3591 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3592 // Found the best possible - return it.
3593 return osr;
3594 }
3595 best = osr;
3596 }
3597 }
3598 }
3599 osr = osr->osr_link();
3600 }
3601
3602 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3603 if (best != nullptr && best->comp_level() >= comp_level) {
3604 return best;
3605 }
3606 return nullptr;
3607 }
3608
3609 // -----------------------------------------------------------------------------------------------------
3610 // Printing
3611
3612 #define BULLET " - "
3613
3614 static const char* state_names[] = {
3615 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3616 };
3617
3618 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3619 for (int i = 0; i < len; i++) {
3620 intptr_t e = start[i];
3621 st->print("%d : " INTPTR_FORMAT, i, e);
3622 if (MetaspaceObj::is_valid((Metadata*)e)) {
3623 st->print(" ");
3624 ((Metadata*)e)->print_value_on(st);
3625 }
3626 st->cr();
3627 }
3628 }
3629
3630 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3631 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3632 }
3633
3634 const char* InstanceKlass::init_state_name() const {
3635 return state_names[init_state()];
3636 }
3637
3638 void InstanceKlass::print_on(outputStream* st) const {
3639 assert(is_klass(), "must be klass");
3640 Klass::print_on(st);
3641
3642 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3643 st->print(BULLET"klass size: %d", size()); st->cr();
3644 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3645 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3646 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3647 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3648 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3649 st->print(BULLET"sub: ");
3650 Klass* sub = subklass();
3651 int n;
3652 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3653 if (n < MaxSubklassPrintSize) {
3654 sub->print_value_on(st);
3655 st->print(" ");
3656 }
3657 }
3658 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3659 st->cr();
3660
3661 if (is_interface()) {
3662 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3663 if (nof_implementors() == 1) {
3664 st->print_cr(BULLET"implementor: ");
3665 st->print(" ");
3666 implementor()->print_value_on(st);
3667 st->cr();
3668 }
3669 }
3670
3671 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3672 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3673 if (Verbose || WizardMode) {
3674 Array<Method*>* method_array = methods();
3675 for (int i = 0; i < method_array->length(); i++) {
3676 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3677 }
3678 }
3679 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3680 if (default_methods() != nullptr) {
3681 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3682 if (Verbose) {
3683 Array<Method*>* method_array = default_methods();
3684 for (int i = 0; i < method_array->length(); i++) {
3685 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3686 }
3687 }
3688 }
3689 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3690 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3691 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3692
3693 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3694
3695 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3696 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3697
3698 if (secondary_supers() != nullptr) {
3699 if (Verbose) {
3700 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3701 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3702 for (int i = 0; i < _secondary_supers->length(); i++) {
3703 ResourceMark rm; // for external_name()
3704 Klass* secondary_super = _secondary_supers->at(i);
3705 st->print(BULLET"%2d:", i);
3706 if (is_hashed) {
3707 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3708 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3709 st->print(" dist:%02d:", distance);
3710 }
3711 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3712 }
3713 }
3714 }
3715 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3716
3717 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3718 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3719 if (source_debug_extension() != nullptr) {
3720 st->print(BULLET"source debug extension: ");
3721 st->print("%s", source_debug_extension());
3722 st->cr();
3723 }
3724 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3725 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3726 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3727 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3728 {
3729 bool have_pv = false;
3730 // previous versions are linked together through the InstanceKlass
3731 for (InstanceKlass* pv_node = previous_versions();
3732 pv_node != nullptr;
3733 pv_node = pv_node->previous_versions()) {
3734 if (!have_pv)
3735 st->print(BULLET"previous version: ");
3736 have_pv = true;
3737 pv_node->constants()->print_value_on(st);
3738 }
3739 if (have_pv) st->cr();
3740 }
3741
3742 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3743 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3744 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3745 print_on_maybe_null(st, BULLET"record components: ", record_components());
3746 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3747 if (java_mirror() != nullptr) {
3748 st->print(BULLET"java mirror: ");
3749 java_mirror()->print_value_on(st);
3750 st->cr();
3751 } else {
3752 st->print_cr(BULLET"java mirror: null");
3753 }
3754 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3755 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3756 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3757 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3758 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3759
3760 FieldPrinter print_static_field(st);
3761 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3762 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3763 FieldPrinter print_nonstatic_field(st);
3764 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3765 ik->print_nonstatic_fields(&print_nonstatic_field);
3766
3767 st->print(BULLET"non-static oop maps: ");
3768 OopMapBlock* map = start_of_nonstatic_oop_maps();
3769 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3770 while (map < end_map) {
3771 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3772 map++;
3773 }
3774 st->cr();
3775 }
3776
3777 void InstanceKlass::print_value_on(outputStream* st) const {
3778 assert(is_klass(), "must be klass");
3779 if (Verbose || WizardMode) access_flags().print_on(st);
3780 name()->print_value_on(st);
3781 }
3782
3783 void FieldPrinter::do_field(fieldDescriptor* fd) {
3784 _st->print(BULLET);
3785 if (_obj == nullptr) {
3786 fd->print_on(_st);
3787 _st->cr();
3788 } else {
3789 fd->print_on_for(_st, _obj);
3790 _st->cr();
3791 }
3792 }
3793
3794
3795 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3796 Klass::oop_print_on(obj, st);
3797
3798 if (this == vmClasses::String_klass()) {
3799 typeArrayOop value = java_lang_String::value(obj);
3800 juint length = java_lang_String::length(obj);
3801 if (value != nullptr &&
3802 value->is_typeArray() &&
3803 length <= (juint) value->length()) {
3804 st->print(BULLET"string: ");
3805 java_lang_String::print(obj, st);
3806 st->cr();
3807 }
3808 }
3809
3810 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj, obj->mark()));
3811 FieldPrinter print_field(st, obj);
3812 print_nonstatic_fields(&print_field);
3813
3814 if (this == vmClasses::Class_klass()) {
3815 st->print(BULLET"signature: ");
3816 java_lang_Class::print_signature(obj, st);
3817 st->cr();
3818 Klass* real_klass = java_lang_Class::as_Klass(obj);
3819 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3820 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3821 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3822 }
3823 } else if (this == vmClasses::MethodType_klass()) {
3824 st->print(BULLET"signature: ");
3825 java_lang_invoke_MethodType::print_signature(obj, st);
3826 st->cr();
3827 }
3828 }
3829
3830 #ifndef PRODUCT
3831
3832 bool InstanceKlass::verify_itable_index(int i) {
3833 int method_count = klassItable::method_count_for_interface(this);
3834 assert(i >= 0 && i < method_count, "index out of bounds");
3835 return true;
3836 }
3837
3838 #endif //PRODUCT
3839
3840 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3841 st->print("a ");
3842 name()->print_value_on(st);
3843 obj->print_address_on(st);
3844 if (this == vmClasses::String_klass()
3845 && java_lang_String::value(obj) != nullptr) {
3846 ResourceMark rm;
3847 int len = java_lang_String::length(obj);
3848 int plen = (len < 24 ? len : 12);
3849 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3850 st->print(" = \"%s\"", str);
3851 if (len > plen)
3852 st->print("...[%d]", len);
3853 } else if (this == vmClasses::Class_klass()) {
3854 Klass* k = java_lang_Class::as_Klass(obj);
3855 st->print(" = ");
3856 if (k != nullptr) {
3857 k->print_value_on(st);
3858 } else {
3859 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3860 st->print("%s", tname ? tname : "type?");
3861 }
3862 } else if (this == vmClasses::MethodType_klass()) {
3863 st->print(" = ");
3864 java_lang_invoke_MethodType::print_signature(obj, st);
3865 } else if (java_lang_boxing_object::is_instance(obj)) {
3866 st->print(" = ");
3867 java_lang_boxing_object::print(obj, st);
3868 } else if (this == vmClasses::LambdaForm_klass()) {
3869 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3870 if (vmentry != nullptr) {
3871 st->print(" => ");
3872 vmentry->print_value_on(st);
3873 }
3874 } else if (this == vmClasses::MemberName_klass()) {
3875 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3876 if (vmtarget != nullptr) {
3877 st->print(" = ");
3878 vmtarget->print_value_on(st);
3879 } else {
3880 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3881 oop name = java_lang_invoke_MemberName::name(obj);
3882 if (clazz != nullptr) {
3883 clazz->print_value_on(st);
3884 } else {
3885 st->print("null");
3886 }
3887 st->print(".");
3888 if (name != nullptr) {
3889 name->print_value_on(st);
3890 } else {
3891 st->print("null");
3892 }
3893 }
3894 }
3895 }
3896
3897 const char* InstanceKlass::internal_name() const {
3898 return external_name();
3899 }
3900
3901 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3902 const ModuleEntry* module_entry,
3903 const ClassFileStream* cfs) const {
3904
3905 if (ClassListWriter::is_enabled()) {
3906 ClassListWriter::write(this, cfs);
3907 }
3908
3909 print_class_load_helper(loader_data, module_entry, cfs);
3910 print_class_load_cause_logging();
3911 }
3912
3913 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3914 const ModuleEntry* module_entry,
3915 const ClassFileStream* cfs) const {
3916
3917 if (!log_is_enabled(Info, class, load)) {
3918 return;
3919 }
3920
3921 ResourceMark rm;
3922 LogMessage(class, load) msg;
3923 stringStream info_stream;
3924
3925 // Name and class hierarchy info
3926 info_stream.print("%s", external_name());
3927
3928 // Source
3929 if (cfs != nullptr) {
3930 if (cfs->source() != nullptr) {
3931 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3932 if (module_name != nullptr) {
3933 // When the boot loader created the stream, it didn't know the module name
3934 // yet. Let's format it now.
3935 if (cfs->from_boot_loader_modules_image()) {
3936 info_stream.print(" source: jrt:/%s", module_name);
3937 } else {
3938 info_stream.print(" source: %s", cfs->source());
3939 }
3940 } else {
3941 info_stream.print(" source: %s", cfs->source());
3942 }
3943 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3944 Thread* current = Thread::current();
3945 Klass* caller = current->is_Java_thread() ?
3946 JavaThread::cast(current)->security_get_caller_class(1):
3947 nullptr;
3948 // caller can be null, for example, during a JVMTI VM_Init hook
3949 if (caller != nullptr) {
3950 info_stream.print(" source: instance of %s", caller->external_name());
3951 } else {
3952 // source is unknown
3953 }
3954 } else {
3955 oop class_loader = loader_data->class_loader();
3956 info_stream.print(" source: %s", class_loader->klass()->external_name());
3957 }
3958 } else {
3959 assert(this->is_shared(), "must be");
3960 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3961 info_stream.print(" source: shared objects file (top)");
3962 } else {
3963 info_stream.print(" source: shared objects file");
3964 }
3965 }
3966
3967 msg.info("%s", info_stream.as_string());
3968
3969 if (log_is_enabled(Debug, class, load)) {
3970 stringStream debug_stream;
3971
3972 // Class hierarchy info
3973 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3974 p2i(this), p2i(superklass()));
3975
3976 // Interfaces
3977 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3978 debug_stream.print(" interfaces:");
3979 int length = local_interfaces()->length();
3980 for (int i = 0; i < length; i++) {
3981 debug_stream.print(" " PTR_FORMAT,
3982 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3983 }
3984 }
3985
3986 // Class loader
3987 debug_stream.print(" loader: [");
3988 loader_data->print_value_on(&debug_stream);
3989 debug_stream.print("]");
3990
3991 // Classfile checksum
3992 if (cfs) {
3993 debug_stream.print(" bytes: %d checksum: %08x",
3994 cfs->length(),
3995 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3996 cfs->length()));
3997 }
3998
3999 msg.debug("%s", debug_stream.as_string());
4000 }
4001 }
4002
4003 void InstanceKlass::print_class_load_cause_logging() const {
4004 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4005 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4006 JavaThread* current = JavaThread::current();
4007 ResourceMark rm(current);
4008 const char* name = external_name();
4009
4010 if (LogClassLoadingCauseFor == nullptr ||
4011 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4012 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4013 return;
4014 }
4015
4016 // Log Java stack first
4017 {
4018 LogMessage(class, load, cause) msg;
4019 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4020
4021 info_stream.print_cr("Java stack when loading %s:", name);
4022 current->print_stack_on(&info_stream);
4023 }
4024
4025 // Log native stack second
4026 if (log_cause_native) {
4027 // Log to string first so that lines can be indented
4028 stringStream stack_stream;
4029 char buf[O_BUFLEN];
4030 address lastpc = nullptr;
4031 NativeStackPrinter nsp(current);
4032 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4033 true /* print_source_info */, -1 /* max stack */);
4034
4035 LogMessage(class, load, cause, native) msg;
4036 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4037 info_stream.print_cr("Native stack when loading %s:", name);
4038
4039 // Print each native stack line to the log
4040 int size = (int) stack_stream.size();
4041 char* stack = stack_stream.as_string();
4042 char* stack_end = stack + size;
4043 char* line_start = stack;
4044 for (char* p = stack; p < stack_end; p++) {
4045 if (*p == '\n') {
4046 *p = '\0';
4047 info_stream.print_cr("\t%s", line_start);
4048 line_start = p + 1;
4049 }
4050 }
4051 if (line_start < stack_end) {
4052 info_stream.print_cr("\t%s", line_start);
4053 }
4054 }
4055 }
4056 }
4057
4058 // Verification
4059
4060 class VerifyFieldClosure: public BasicOopIterateClosure {
4061 protected:
4062 template <class T> void do_oop_work(T* p) {
4063 oop obj = RawAccess<>::oop_load(p);
4064 if (!oopDesc::is_oop_or_null(obj)) {
4065 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4066 Universe::print_on(tty);
4067 guarantee(false, "boom");
4068 }
4069 }
4070 public:
4071 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4072 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4073 };
4074
4075 void InstanceKlass::verify_on(outputStream* st) {
4076 #ifndef PRODUCT
4077 // Avoid redundant verifies, this really should be in product.
4078 if (_verify_count == Universe::verify_count()) return;
4079 _verify_count = Universe::verify_count();
4080 #endif
4081
4082 // Verify Klass
4083 Klass::verify_on(st);
4084
4085 // Verify that klass is present in ClassLoaderData
4086 guarantee(class_loader_data()->contains_klass(this),
4087 "this class isn't found in class loader data");
4088
4089 // Verify vtables
4090 if (is_linked()) {
4091 // $$$ This used to be done only for m/s collections. Doing it
4092 // always seemed a valid generalization. (DLD -- 6/00)
4093 vtable().verify(st);
4094 }
4095
4096 // Verify first subklass
4097 if (subklass() != nullptr) {
4098 guarantee(subklass()->is_klass(), "should be klass");
4099 }
4100
4101 // Verify siblings
4102 Klass* super = this->super();
4103 Klass* sib = next_sibling();
4104 if (sib != nullptr) {
4105 if (sib == this) {
4106 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4107 }
4108
4109 guarantee(sib->is_klass(), "should be klass");
4110 guarantee(sib->super() == super, "siblings should have same superklass");
4111 }
4112
4113 // Verify local interfaces
4114 if (local_interfaces()) {
4115 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4116 for (int j = 0; j < local_interfaces->length(); j++) {
4117 InstanceKlass* e = local_interfaces->at(j);
4118 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4119 }
4120 }
4121
4122 // Verify transitive interfaces
4123 if (transitive_interfaces() != nullptr) {
4124 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4125 for (int j = 0; j < transitive_interfaces->length(); j++) {
4126 InstanceKlass* e = transitive_interfaces->at(j);
4127 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4128 }
4129 }
4130
4131 // Verify methods
4132 if (methods() != nullptr) {
4133 Array<Method*>* methods = this->methods();
4134 for (int j = 0; j < methods->length(); j++) {
4135 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4136 }
4137 for (int j = 0; j < methods->length() - 1; j++) {
4138 Method* m1 = methods->at(j);
4139 Method* m2 = methods->at(j + 1);
4140 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4141 }
4142 }
4143
4144 // Verify method ordering
4145 if (method_ordering() != nullptr) {
4146 Array<int>* method_ordering = this->method_ordering();
4147 int length = method_ordering->length();
4148 if (JvmtiExport::can_maintain_original_method_order() ||
4149 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4150 guarantee(length == methods()->length(), "invalid method ordering length");
4151 jlong sum = 0;
4152 for (int j = 0; j < length; j++) {
4153 int original_index = method_ordering->at(j);
4154 guarantee(original_index >= 0, "invalid method ordering index");
4155 guarantee(original_index < length, "invalid method ordering index");
4156 sum += original_index;
4157 }
4158 // Verify sum of indices 0,1,...,length-1
4159 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4160 } else {
4161 guarantee(length == 0, "invalid method ordering length");
4162 }
4163 }
4164
4165 // Verify default methods
4166 if (default_methods() != nullptr) {
4167 Array<Method*>* methods = this->default_methods();
4168 for (int j = 0; j < methods->length(); j++) {
4169 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4170 }
4171 for (int j = 0; j < methods->length() - 1; j++) {
4172 Method* m1 = methods->at(j);
4173 Method* m2 = methods->at(j + 1);
4174 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4175 }
4176 }
4177
4178 // Verify JNI static field identifiers
4179 if (jni_ids() != nullptr) {
4180 jni_ids()->verify(this);
4181 }
4182
4183 // Verify other fields
4184 if (constants() != nullptr) {
4185 guarantee(constants()->is_constantPool(), "should be constant pool");
4186 }
4187 }
4188
4189 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4190 Klass::oop_verify_on(obj, st);
4191 VerifyFieldClosure blk;
4192 obj->oop_iterate(&blk);
4193 }
4194
4195
4196 // JNIid class for jfieldIDs only
4197 // Note to reviewers:
4198 // These JNI functions are just moved over to column 1 and not changed
4199 // in the compressed oops workspace.
4200 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4201 _holder = holder;
4202 _offset = offset;
4203 _next = next;
4204 debug_only(_is_static_field_id = false;)
4205 }
4206
4207
4208 JNIid* JNIid::find(int offset) {
4209 JNIid* current = this;
4210 while (current != nullptr) {
4211 if (current->offset() == offset) return current;
4212 current = current->next();
4213 }
4214 return nullptr;
4215 }
4216
4217 void JNIid::deallocate(JNIid* current) {
4218 while (current != nullptr) {
4219 JNIid* next = current->next();
4220 delete current;
4221 current = next;
4222 }
4223 }
4224
4225
4226 void JNIid::verify(Klass* holder) {
4227 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4228 int end_field_offset;
4229 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4230
4231 JNIid* current = this;
4232 while (current != nullptr) {
4233 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4234 #ifdef ASSERT
4235 int o = current->offset();
4236 if (current->is_static_field_id()) {
4237 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4238 }
4239 #endif
4240 current = current->next();
4241 }
4242 }
4243
4244 void InstanceKlass::set_init_state(ClassState state) {
4245 #ifdef ASSERT
4246 bool good_state = is_shared() ? (_init_state <= state)
4247 : (_init_state < state);
4248 assert(good_state || state == allocated, "illegal state transition");
4249 #endif
4250 assert(_init_thread == nullptr, "should be cleared before state change");
4251 Atomic::release_store(&_init_state, state);
4252 }
4253
4254 #if INCLUDE_JVMTI
4255
4256 // RedefineClasses() support for previous versions
4257
4258 // Globally, there is at least one previous version of a class to walk
4259 // during class unloading, which is saved because old methods in the class
4260 // are still running. Otherwise the previous version list is cleaned up.
4261 bool InstanceKlass::_should_clean_previous_versions = false;
4262
4263 // Returns true if there are previous versions of a class for class
4264 // unloading only. Also resets the flag to false. purge_previous_version
4265 // will set the flag to true if there are any left, i.e., if there's any
4266 // work to do for next time. This is to avoid the expensive code cache
4267 // walk in CLDG::clean_deallocate_lists().
4268 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4269 bool ret = _should_clean_previous_versions;
4270 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4271 ret ? "true" : "false");
4272 _should_clean_previous_versions = false;
4273 return ret;
4274 }
4275
4276 // This nulls out jmethodIDs for all methods in 'klass'
4277 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4278 // during class unloading.
4279 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4280 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4281 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4282 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4283 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4284 Array<Method*>* method_refs = klass->methods();
4285 for (int k = 0; k < method_refs->length(); k++) {
4286 Method* method = method_refs->at(k);
4287 if (method != nullptr && method->is_obsolete()) {
4288 method->clear_jmethod_id();
4289 }
4290 }
4291 }
4292
4293 // Purge previous versions before adding new previous versions of the class and
4294 // during class unloading.
4295 void InstanceKlass::purge_previous_version_list() {
4296 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4297 assert(has_been_redefined(), "Should only be called for main class");
4298
4299 // Quick exit.
4300 if (previous_versions() == nullptr) {
4301 return;
4302 }
4303
4304 // This klass has previous versions so see what we can cleanup
4305 // while it is safe to do so.
4306
4307 int deleted_count = 0; // leave debugging breadcrumbs
4308 int live_count = 0;
4309 ClassLoaderData* loader_data = class_loader_data();
4310 assert(loader_data != nullptr, "should never be null");
4311
4312 ResourceMark rm;
4313 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4314
4315 // previous versions are linked together through the InstanceKlass
4316 InstanceKlass* pv_node = previous_versions();
4317 InstanceKlass* last = this;
4318 int version = 0;
4319
4320 // check the previous versions list
4321 for (; pv_node != nullptr; ) {
4322
4323 ConstantPool* pvcp = pv_node->constants();
4324 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4325
4326 if (!pvcp->on_stack()) {
4327 // If the constant pool isn't on stack, none of the methods
4328 // are executing. Unlink this previous_version.
4329 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4330 // so will be deallocated during the next phase of class unloading.
4331 log_trace(redefine, class, iklass, purge)
4332 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4333 // Unlink from previous version list.
4334 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4335 InstanceKlass* next = pv_node->previous_versions();
4336 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4337 pv_node->link_previous_versions(nullptr); // point next to null
4338 last->link_previous_versions(next);
4339 // Delete this node directly. Nothing is referring to it and we don't
4340 // want it to increase the counter for metadata to delete in CLDG.
4341 MetadataFactory::free_metadata(loader_data, pv_node);
4342 pv_node = next;
4343 deleted_count++;
4344 version++;
4345 continue;
4346 } else {
4347 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4348 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4349 live_count++;
4350 if (pvcp->is_shared()) {
4351 // Shared previous versions can never be removed so no cleaning is needed.
4352 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4353 } else {
4354 // Previous version alive, set that clean is needed for next time.
4355 _should_clean_previous_versions = true;
4356 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4357 }
4358 }
4359
4360 // next previous version
4361 last = pv_node;
4362 pv_node = pv_node->previous_versions();
4363 version++;
4364 }
4365 log_trace(redefine, class, iklass, purge)
4366 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4367 }
4368
4369 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4370 int emcp_method_count) {
4371 int obsolete_method_count = old_methods->length() - emcp_method_count;
4372
4373 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4374 _previous_versions != nullptr) {
4375 // We have a mix of obsolete and EMCP methods so we have to
4376 // clear out any matching EMCP method entries the hard way.
4377 int local_count = 0;
4378 for (int i = 0; i < old_methods->length(); i++) {
4379 Method* old_method = old_methods->at(i);
4380 if (old_method->is_obsolete()) {
4381 // only obsolete methods are interesting
4382 Symbol* m_name = old_method->name();
4383 Symbol* m_signature = old_method->signature();
4384
4385 // previous versions are linked together through the InstanceKlass
4386 int j = 0;
4387 for (InstanceKlass* prev_version = _previous_versions;
4388 prev_version != nullptr;
4389 prev_version = prev_version->previous_versions(), j++) {
4390
4391 Array<Method*>* method_refs = prev_version->methods();
4392 for (int k = 0; k < method_refs->length(); k++) {
4393 Method* method = method_refs->at(k);
4394
4395 if (!method->is_obsolete() &&
4396 method->name() == m_name &&
4397 method->signature() == m_signature) {
4398 // The current RedefineClasses() call has made all EMCP
4399 // versions of this method obsolete so mark it as obsolete
4400 log_trace(redefine, class, iklass, add)
4401 ("%s(%s): flush obsolete method @%d in version @%d",
4402 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4403
4404 method->set_is_obsolete();
4405 break;
4406 }
4407 }
4408
4409 // The previous loop may not find a matching EMCP method, but
4410 // that doesn't mean that we can optimize and not go any
4411 // further back in the PreviousVersion generations. The EMCP
4412 // method for this generation could have already been made obsolete,
4413 // but there still may be an older EMCP method that has not
4414 // been made obsolete.
4415 }
4416
4417 if (++local_count >= obsolete_method_count) {
4418 // no more obsolete methods so bail out now
4419 break;
4420 }
4421 }
4422 }
4423 }
4424 }
4425
4426 // Save the scratch_class as the previous version if any of the methods are running.
4427 // The previous_versions are used to set breakpoints in EMCP methods and they are
4428 // also used to clean MethodData links to redefined methods that are no longer running.
4429 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4430 int emcp_method_count) {
4431 assert(Thread::current()->is_VM_thread(),
4432 "only VMThread can add previous versions");
4433
4434 ResourceMark rm;
4435 log_trace(redefine, class, iklass, add)
4436 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4437
4438 // Clean out old previous versions for this class
4439 purge_previous_version_list();
4440
4441 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4442 // a previous redefinition may be made obsolete by this redefinition.
4443 Array<Method*>* old_methods = scratch_class->methods();
4444 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4445
4446 // If the constant pool for this previous version of the class
4447 // is not marked as being on the stack, then none of the methods
4448 // in this previous version of the class are on the stack so
4449 // we don't need to add this as a previous version.
4450 ConstantPool* cp_ref = scratch_class->constants();
4451 if (!cp_ref->on_stack()) {
4452 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4453 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4454 return;
4455 }
4456
4457 // Add previous version if any methods are still running or if this is
4458 // a shared class which should never be removed.
4459 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4460 scratch_class->link_previous_versions(previous_versions());
4461 link_previous_versions(scratch_class);
4462 if (cp_ref->is_shared()) {
4463 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4464 } else {
4465 // We only set clean_previous_versions flag for processing during class
4466 // unloading for non-shared classes.
4467 _should_clean_previous_versions = true;
4468 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4469 }
4470 } // end add_previous_version()
4471
4472 #endif // INCLUDE_JVMTI
4473
4474 Method* InstanceKlass::method_with_idnum(int idnum) {
4475 Method* m = nullptr;
4476 if (idnum < methods()->length()) {
4477 m = methods()->at(idnum);
4478 }
4479 if (m == nullptr || m->method_idnum() != idnum) {
4480 for (int index = 0; index < methods()->length(); ++index) {
4481 m = methods()->at(index);
4482 if (m->method_idnum() == idnum) {
4483 return m;
4484 }
4485 }
4486 // None found, return null for the caller to handle.
4487 return nullptr;
4488 }
4489 return m;
4490 }
4491
4492
4493 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4494 if (idnum >= methods()->length()) {
4495 return nullptr;
4496 }
4497 Method* m = methods()->at(idnum);
4498 if (m != nullptr && m->orig_method_idnum() == idnum) {
4499 return m;
4500 }
4501 // Obsolete method idnum does not match the original idnum
4502 for (int index = 0; index < methods()->length(); ++index) {
4503 m = methods()->at(index);
4504 if (m->orig_method_idnum() == idnum) {
4505 return m;
4506 }
4507 }
4508 // None found, return null for the caller to handle.
4509 return nullptr;
4510 }
4511
4512
4513 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4514 InstanceKlass* holder = get_klass_version(version);
4515 if (holder == nullptr) {
4516 return nullptr; // The version of klass is gone, no method is found
4517 }
4518 Method* method = holder->method_with_orig_idnum(idnum);
4519 return method;
4520 }
4521
4522 #if INCLUDE_JVMTI
4523 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4524 return _cached_class_file;
4525 }
4526
4527 jint InstanceKlass::get_cached_class_file_len() {
4528 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4529 }
4530
4531 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4532 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4533 }
4534 #endif
4535
4536 // Make a step iterating over the class hierarchy under the root class.
4537 // Skips subclasses if requested.
4538 void ClassHierarchyIterator::next() {
4539 assert(_current != nullptr, "required");
4540 if (_visit_subclasses && _current->subklass() != nullptr) {
4541 _current = _current->subklass();
4542 return; // visit next subclass
4543 }
4544 _visit_subclasses = true; // reset
4545 while (_current->next_sibling() == nullptr && _current != _root) {
4546 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4547 }
4548 if (_current == _root) {
4549 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4550 _current = nullptr;
4551 return;
4552 }
4553 _current = _current->next_sibling();
4554 return; // visit next sibling subclass
4555 }