1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "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/stringUtils.hpp"
100 #include "utilities/pair.hpp"
101 #ifdef COMPILER1
102 #include "c1/c1_Compiler.hpp"
103 #endif
104 #if INCLUDE_JFR
105 #include "jfr/jfrEvents.hpp"
106 #endif
107
108 #ifdef DTRACE_ENABLED
109
110
111 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
112 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
113 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
114 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
115 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
116 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
117 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
118 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
119 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
120 { \
121 char* data = nullptr; \
122 int len = 0; \
123 Symbol* clss_name = name(); \
124 if (clss_name != nullptr) { \
125 data = (char*)clss_name->bytes(); \
126 len = clss_name->utf8_length(); \
127 } \
128 HOTSPOT_CLASS_INITIALIZATION_##type( \
129 data, len, (void*)class_loader(), thread_type); \
130 }
131
132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
133 { \
134 char* data = nullptr; \
135 int len = 0; \
136 Symbol* clss_name = name(); \
137 if (clss_name != nullptr) { \
138 data = (char*)clss_name->bytes(); \
139 len = clss_name->utf8_length(); \
140 } \
141 HOTSPOT_CLASS_INITIALIZATION_##type( \
142 data, len, (void*)class_loader(), thread_type, wait); \
143 }
144
145 #else // ndef DTRACE_ENABLED
146
147 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
148 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
149
150 #endif // ndef DTRACE_ENABLED
151
152 bool InstanceKlass::_finalization_enabled = true;
153
154 static inline bool is_class_loader(const Symbol* class_name,
155 const ClassFileParser& parser) {
156 assert(class_name != nullptr, "invariant");
157
158 if (class_name == vmSymbols::java_lang_ClassLoader()) {
159 return true;
160 }
161
162 if (vmClasses::ClassLoader_klass_loaded()) {
163 const Klass* const super_klass = parser.super_klass();
164 if (super_klass != nullptr) {
165 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
166 return true;
167 }
168 }
169 }
170 return false;
171 }
172
173 static inline bool is_stack_chunk_class(const Symbol* class_name,
174 const ClassLoaderData* loader_data) {
175 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
176 loader_data->is_the_null_class_loader_data());
177 }
178
179 // private: called to verify that k is a static member of this nest.
180 // We know that k is an instance class in the same package and hence the
181 // same classloader.
182 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
183 assert(!is_hidden(), "unexpected hidden class");
184 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
185 if (log_is_enabled(Trace, class, nestmates)) {
186 ResourceMark rm(current);
187 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
188 k->external_name(), this->external_name());
189 }
190 return false;
191 }
192
193 if (log_is_enabled(Trace, class, nestmates)) {
194 ResourceMark rm(current);
195 log_trace(class, nestmates)("Checking nest membership of %s in %s",
196 k->external_name(), this->external_name());
197 }
198
199 // Check for the named class in _nest_members.
200 // We don't resolve, or load, any classes.
201 for (int i = 0; i < _nest_members->length(); i++) {
202 int cp_index = _nest_members->at(i);
203 Symbol* name = _constants->klass_name_at(cp_index);
204 if (name == k->name()) {
205 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
206 return true;
207 }
208 }
209 log_trace(class, nestmates)("- class is NOT a nest member!");
210 return false;
211 }
212
213 // Called to verify that k is a permitted subclass of this class
214 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k) const {
215 Thread* current = Thread::current();
216 assert(k != nullptr, "sanity check");
217 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
218 "unexpected empty _permitted_subclasses array");
219
220 if (log_is_enabled(Trace, class, sealed)) {
221 ResourceMark rm(current);
222 log_trace(class, sealed)("Checking for permitted subclass of %s in %s",
223 k->external_name(), this->external_name());
224 }
225
226 // Check that the class and its super are in the same module.
227 if (k->module() != this->module()) {
228 ResourceMark rm(current);
229 log_trace(class, sealed)("Check failed for same module of permitted subclass %s and sealed class %s",
230 k->external_name(), this->external_name());
231 return false;
232 }
233
234 if (!k->is_public() && !is_same_class_package(k)) {
235 ResourceMark rm(current);
236 log_trace(class, sealed)("Check failed, subclass %s not public and not in the same package as sealed class %s",
237 k->external_name(), this->external_name());
238 return false;
239 }
240
241 for (int i = 0; i < _permitted_subclasses->length(); i++) {
242 int cp_index = _permitted_subclasses->at(i);
243 Symbol* name = _constants->klass_name_at(cp_index);
244 if (name == k->name()) {
245 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
246 return true;
247 }
248 }
249 log_trace(class, sealed)("- class is NOT a permitted subclass!");
250 return false;
251 }
252
253 // Return nest-host class, resolving, validating and saving it if needed.
254 // In cases where this is called from a thread that cannot do classloading
255 // (such as a native JIT thread) then we simply return null, which in turn
256 // causes the access check to return false. Such code will retry the access
257 // from a more suitable environment later. Otherwise the _nest_host is always
258 // set once this method returns.
259 // Any errors from nest-host resolution must be preserved so they can be queried
260 // from higher-level access checking code, and reported as part of access checking
261 // exceptions.
262 // VirtualMachineErrors are propagated with a null return.
263 // Under any conditions where the _nest_host can be set to non-null the resulting
264 // value of it and, if applicable, the nest host resolution/validation error,
265 // are idempotent.
266 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
267 InstanceKlass* nest_host_k = _nest_host;
268 if (nest_host_k != nullptr) {
269 return nest_host_k;
270 }
271
272 ResourceMark rm(THREAD);
273
274 // need to resolve and save our nest-host class.
275 if (_nest_host_index != 0) { // we have a real nest_host
276 // Before trying to resolve check if we're in a suitable context
277 bool can_resolve = THREAD->can_call_java();
278 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
279 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
280 this->external_name());
281 return nullptr; // sentinel to say "try again from a different context"
282 }
283
284 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
285 this->external_name(),
286 _constants->klass_name_at(_nest_host_index)->as_C_string());
287
288 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
289 if (HAS_PENDING_EXCEPTION) {
290 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
291 return nullptr; // propagate VMEs
292 }
293 stringStream ss;
294 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
295 ss.print("Nest host resolution of %s with host %s failed: ",
296 this->external_name(), target_host_class);
297 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
298 const char* msg = ss.as_string(true /* on C-heap */);
299 constantPoolHandle cph(THREAD, constants());
300 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
301 CLEAR_PENDING_EXCEPTION;
302
303 log_trace(class, nestmates)("%s", msg);
304 } else {
305 // A valid nest-host is an instance class in the current package that lists this
306 // class as a nest member. If any of these conditions are not met the class is
307 // its own nest-host.
308 const char* error = nullptr;
309
310 // JVMS 5.4.4 indicates package check comes first
311 if (is_same_class_package(k)) {
312 // Now check actual membership. We can't be a member if our "host" is
313 // not an instance class.
314 if (k->is_instance_klass()) {
315 nest_host_k = InstanceKlass::cast(k);
316 bool is_member = nest_host_k->has_nest_member(THREAD, this);
317 if (is_member) {
318 _nest_host = nest_host_k; // save resolved nest-host value
319
320 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
321 this->external_name(), k->external_name());
322 return nest_host_k;
323 } else {
324 error = "current type is not listed as a nest member";
325 }
326 } else {
327 error = "host is not an instance class";
328 }
329 } else {
330 error = "types are in different packages";
331 }
332
333 // something went wrong, so record what and log it
334 {
335 stringStream ss;
336 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
337 this->external_name(),
338 this->class_loader_data()->loader_name_and_id(),
339 k->external_name(),
340 k->class_loader_data()->loader_name_and_id(),
341 error);
342 const char* msg = ss.as_string(true /* on C-heap */);
343 constantPoolHandle cph(THREAD, constants());
344 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
345 log_trace(class, nestmates)("%s", msg);
346 }
347 }
348 } else {
349 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
350 this->external_name());
351 }
352
353 // Either not in an explicit nest, or else an error occurred, so
354 // the nest-host is set to `this`. Any thread that sees this assignment
355 // will also see any setting of nest_host_error(), if applicable.
356 return (_nest_host = this);
357 }
358
359 // Dynamic nest member support: set this class's nest host to the given class.
360 // This occurs as part of the class definition, as soon as the instanceKlass
361 // has been created and doesn't require further resolution. The code:
362 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
363 // results in:
364 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
365 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
366 // We also know the "host" is a valid nest-host in the same package so we can
367 // assert some of those facts.
368 void InstanceKlass::set_nest_host(InstanceKlass* host) {
369 assert(is_hidden(), "must be a hidden class");
370 assert(host != nullptr, "null nest host specified");
371 assert(_nest_host == nullptr, "current class has resolved nest-host");
372 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
373 nest_host_error());
374 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
375 (host->_nest_host == host), "proposed host is not a valid nest-host");
376 // Can't assert this as package is not set yet:
377 // assert(is_same_class_package(host), "proposed host is in wrong package");
378
379 if (log_is_enabled(Trace, class, nestmates)) {
380 ResourceMark rm;
381 const char* msg = "";
382 // a hidden class does not expect a statically defined nest-host
383 if (_nest_host_index > 0) {
384 msg = "(the NestHost attribute in the current class is ignored)";
385 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
386 msg = "(the NestMembers attribute in the current class is ignored)";
387 }
388 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
389 this->external_name(),
390 host->external_name(),
391 msg);
392 }
393 // set dynamic nest host
394 _nest_host = host;
395 // Record dependency to keep nest host from being unloaded before this class.
396 ClassLoaderData* this_key = class_loader_data();
397 assert(this_key != nullptr, "sanity");
398 this_key->record_dependency(host);
399 }
400
401 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
402 // or we are k's nest_host - all of which is covered by comparing the two
403 // resolved_nest_hosts.
404 // Any exceptions (i.e. VMEs) are propagated.
405 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
406
407 assert(this != k, "this should be handled by higher-level code");
408
409 // Per JVMS 5.4.4 we first resolve and validate the current class, then
410 // the target class k.
411
412 InstanceKlass* cur_host = nest_host(CHECK_false);
413 if (cur_host == nullptr) {
414 return false;
415 }
416
417 Klass* k_nest_host = k->nest_host(CHECK_false);
418 if (k_nest_host == nullptr) {
419 return false;
420 }
421
422 bool access = (cur_host == k_nest_host);
423
424 ResourceMark rm(THREAD);
425 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
426 this->external_name(),
427 access ? "" : "NOT ",
428 k->external_name());
429 return access;
430 }
431
432 const char* InstanceKlass::nest_host_error() {
433 if (_nest_host_index == 0) {
434 return nullptr;
435 } else {
436 constantPoolHandle cph(Thread::current(), constants());
437 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
438 }
439 }
440
441 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
442 bool use_class_space, TRAPS) throw() {
443 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
444 }
445
446 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
447 const int size = InstanceKlass::size(parser.vtable_size(),
448 parser.itable_size(),
449 nonstatic_oop_map_size(parser.total_oop_map_count()),
450 parser.is_interface());
451
452 const Symbol* const class_name = parser.class_name();
453 assert(class_name != nullptr, "invariant");
454 ClassLoaderData* loader_data = parser.loader_data();
455 assert(loader_data != nullptr, "invariant");
456
457 InstanceKlass* ik;
458 const bool use_class_space = !parser.is_interface() && !parser.is_abstract();
459
460 // Allocation
461 if (parser.is_instance_ref_klass()) {
462 // java.lang.ref.Reference
463 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
464 } else if (class_name == vmSymbols::java_lang_Class()) {
465 // mirror - java.lang.Class
466 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
467 } else if (is_stack_chunk_class(class_name, loader_data)) {
468 // stack chunk
469 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
470 } else if (is_class_loader(class_name, parser)) {
471 // class loader - java.lang.ClassLoader
472 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
473 } else {
474 // normal
475 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
476 }
477
478 // Check for pending exception before adding to the loader data and incrementing
479 // class count. Can get OOM here.
480 if (HAS_PENDING_EXCEPTION) {
481 return nullptr;
482 }
483
484 return ik;
485 }
486
487
488 // copy method ordering from resource area to Metaspace
489 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
490 if (m != nullptr) {
491 // allocate a new array and copy contents (memcpy?)
492 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
493 for (int i = 0; i < m->length(); i++) {
494 _method_ordering->at_put(i, m->at(i));
495 }
496 } else {
497 _method_ordering = Universe::the_empty_int_array();
498 }
499 }
500
501 // create a new array of vtable_indices for default methods
502 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
503 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
504 assert(default_vtable_indices() == nullptr, "only create once");
505 set_default_vtable_indices(vtable_indices);
506 return vtable_indices;
507 }
508
509
510 InstanceKlass::InstanceKlass() {
511 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
512 }
513
514 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
515 Klass(kind),
516 _nest_members(nullptr),
517 _nest_host(nullptr),
518 _permitted_subclasses(nullptr),
519 _record_components(nullptr),
520 _static_field_size(parser.static_field_size()),
521 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
522 _itable_len(parser.itable_size()),
523 _nest_host_index(0),
524 _init_state(allocated),
525 _reference_type(reference_type),
526 _init_thread(nullptr)
527 {
528 set_vtable_length(parser.vtable_size());
529 set_access_flags(parser.access_flags());
530 if (parser.is_hidden()) set_is_hidden();
531 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
532 false));
533
534 assert(nullptr == _methods, "underlying memory not zeroed?");
535 assert(is_instance_klass(), "is layout incorrect?");
536 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
537 }
538
539 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
540 Array<Method*>* methods) {
541 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
542 !methods->is_shared()) {
543 for (int i = 0; i < methods->length(); i++) {
544 Method* method = methods->at(i);
545 if (method == nullptr) continue; // maybe null if error processing
546 // Only want to delete methods that are not executing for RedefineClasses.
547 // The previous version will point to them so they're not totally dangling
548 assert (!method->on_stack(), "shouldn't be called with methods on stack");
549 MetadataFactory::free_metadata(loader_data, method);
550 }
551 MetadataFactory::free_array<Method*>(loader_data, methods);
552 }
553 }
554
555 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
556 const Klass* super_klass,
557 Array<InstanceKlass*>* local_interfaces,
558 Array<InstanceKlass*>* transitive_interfaces) {
559 // Only deallocate transitive interfaces if not empty, same as super class
560 // or same as local interfaces. See code in parseClassFile.
561 Array<InstanceKlass*>* ti = transitive_interfaces;
562 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
563 // check that the interfaces don't come from super class
564 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
565 InstanceKlass::cast(super_klass)->transitive_interfaces();
566 if (ti != sti && ti != nullptr && !ti->is_shared()) {
567 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
568 }
569 }
570
571 // local interfaces can be empty
572 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
573 local_interfaces != nullptr && !local_interfaces->is_shared()) {
574 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
575 }
576 }
577
578 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
579 Array<RecordComponent*>* record_components) {
580 if (record_components != nullptr && !record_components->is_shared()) {
581 for (int i = 0; i < record_components->length(); i++) {
582 RecordComponent* record_component = record_components->at(i);
583 MetadataFactory::free_metadata(loader_data, record_component);
584 }
585 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
586 }
587 }
588
589 // This function deallocates the metadata and C heap pointers that the
590 // InstanceKlass points to.
591 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
592 // Orphan the mirror first, CMS thinks it's still live.
593 if (java_mirror() != nullptr) {
594 java_lang_Class::set_klass(java_mirror(), nullptr);
595 }
596
597 // Also remove mirror from handles
598 loader_data->remove_handle(_java_mirror);
599
600 // Need to take this class off the class loader data list.
601 loader_data->remove_class(this);
602
603 // The array_klass for this class is created later, after error handling.
604 // For class redefinition, we keep the original class so this scratch class
605 // doesn't have an array class. Either way, assert that there is nothing
606 // to deallocate.
607 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
608
609 // Release C heap allocated data that this points to, which includes
610 // reference counting symbol names.
611 // Can't release the constant pool or MethodData C heap data here because the constant
612 // pool can be deallocated separately from the InstanceKlass for default methods and
613 // redefine classes. MethodData can also be released separately.
614 release_C_heap_structures(/* release_sub_metadata */ false);
615
616 deallocate_methods(loader_data, methods());
617 set_methods(nullptr);
618
619 deallocate_record_components(loader_data, record_components());
620 set_record_components(nullptr);
621
622 if (method_ordering() != nullptr &&
623 method_ordering() != Universe::the_empty_int_array() &&
624 !method_ordering()->is_shared()) {
625 MetadataFactory::free_array<int>(loader_data, method_ordering());
626 }
627 set_method_ordering(nullptr);
628
629 // default methods can be empty
630 if (default_methods() != nullptr &&
631 default_methods() != Universe::the_empty_method_array() &&
632 !default_methods()->is_shared()) {
633 MetadataFactory::free_array<Method*>(loader_data, default_methods());
634 }
635 // Do NOT deallocate the default methods, they are owned by superinterfaces.
636 set_default_methods(nullptr);
637
638 // default methods vtable indices can be empty
639 if (default_vtable_indices() != nullptr &&
640 !default_vtable_indices()->is_shared()) {
641 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
642 }
643 set_default_vtable_indices(nullptr);
644
645
646 // This array is in Klass, but remove it with the InstanceKlass since
647 // this place would be the only caller and it can share memory with transitive
648 // interfaces.
649 if (secondary_supers() != nullptr &&
650 secondary_supers() != Universe::the_empty_klass_array() &&
651 // see comments in compute_secondary_supers about the following cast
652 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
653 !secondary_supers()->is_shared()) {
654 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
655 }
656 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
657
658 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
659 set_transitive_interfaces(nullptr);
660 set_local_interfaces(nullptr);
661
662 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
663 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
664 }
665 set_fieldinfo_stream(nullptr);
666
667 if (fields_status() != nullptr && !fields_status()->is_shared()) {
668 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
669 }
670 set_fields_status(nullptr);
671
672 // If a method from a redefined class is using this constant pool, don't
673 // delete it, yet. The new class's previous version will point to this.
674 if (constants() != nullptr) {
675 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
676 if (!constants()->is_shared()) {
677 MetadataFactory::free_metadata(loader_data, constants());
678 }
679 // Delete any cached resolution errors for the constant pool
680 SystemDictionary::delete_resolution_error(constants());
681
682 set_constants(nullptr);
683 }
684
685 if (inner_classes() != nullptr &&
686 inner_classes() != Universe::the_empty_short_array() &&
687 !inner_classes()->is_shared()) {
688 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
689 }
690 set_inner_classes(nullptr);
691
692 if (nest_members() != nullptr &&
693 nest_members() != Universe::the_empty_short_array() &&
694 !nest_members()->is_shared()) {
695 MetadataFactory::free_array<jushort>(loader_data, nest_members());
696 }
697 set_nest_members(nullptr);
698
699 if (permitted_subclasses() != nullptr &&
700 permitted_subclasses() != Universe::the_empty_short_array() &&
701 !permitted_subclasses()->is_shared()) {
702 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
703 }
704 set_permitted_subclasses(nullptr);
705
706 // We should deallocate the Annotations instance if it's not in shared spaces.
707 if (annotations() != nullptr && !annotations()->is_shared()) {
708 MetadataFactory::free_metadata(loader_data, annotations());
709 }
710 set_annotations(nullptr);
711
712 SystemDictionaryShared::handle_class_unloading(this);
713
714 #if INCLUDE_CDS_JAVA_HEAP
715 if (CDSConfig::is_dumping_heap()) {
716 HeapShared::remove_scratch_objects(this);
717 }
718 #endif
719 }
720
721 bool InstanceKlass::is_record() const {
722 return _record_components != nullptr &&
723 is_final() &&
724 java_super() == vmClasses::Record_klass();
725 }
726
727 bool InstanceKlass::is_sealed() const {
728 return _permitted_subclasses != nullptr &&
729 _permitted_subclasses != Universe::the_empty_short_array();
730 }
731
732 bool InstanceKlass::should_be_initialized() const {
733 return !is_initialized();
734 }
735
736 klassItable InstanceKlass::itable() const {
737 return klassItable(const_cast<InstanceKlass*>(this));
738 }
739
740 // JVMTI spec thinks there are signers and protection domain in the
741 // instanceKlass. These accessors pretend these fields are there.
742 // The hprof specification also thinks these fields are in InstanceKlass.
743 oop InstanceKlass::protection_domain() const {
744 // return the protection_domain from the mirror
745 return java_lang_Class::protection_domain(java_mirror());
746 }
747
748 objArrayOop InstanceKlass::signers() const {
749 // return the signers from the mirror
750 return java_lang_Class::signers(java_mirror());
751 }
752
753 oop InstanceKlass::init_lock() const {
754 // return the init lock from the mirror
755 oop lock = java_lang_Class::init_lock(java_mirror());
756 // Prevent reordering with any access of initialization state
757 OrderAccess::loadload();
758 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
759 "only fully initialized state can have a null lock");
760 return lock;
761 }
762
763 // Set the initialization lock to null so the object can be GC'ed. Any racing
764 // threads to get this lock will see a null lock and will not lock.
765 // That's okay because they all check for initialized state after getting
766 // the lock and return.
767 void InstanceKlass::fence_and_clear_init_lock() {
768 // make sure previous stores are all done, notably the init_state.
769 OrderAccess::storestore();
770 java_lang_Class::clear_init_lock(java_mirror());
771 assert(!is_not_initialized(), "class must be initialized now");
772 }
773
774
775 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
776 // process. The step comments refers to the procedure described in that section.
777 // Note: implementation moved to static method to expose the this pointer.
778 void InstanceKlass::initialize(TRAPS) {
779 if (this->should_be_initialized()) {
780 initialize_impl(CHECK);
781 // Note: at this point the class may be initialized
782 // OR it may be in the state of being initialized
783 // in case of recursive initialization!
784 } else {
785 assert(is_initialized(), "sanity check");
786 }
787 }
788
789
790 bool InstanceKlass::verify_code(TRAPS) {
791 // 1) Verify the bytecodes
792 return Verifier::verify(this, should_verify_class(), THREAD);
793 }
794
795 void InstanceKlass::link_class(TRAPS) {
796 assert(is_loaded(), "must be loaded");
797 if (!is_linked()) {
798 link_class_impl(CHECK);
799 }
800 }
801
802 // Called to verify that a class can link during initialization, without
803 // throwing a VerifyError.
804 bool InstanceKlass::link_class_or_fail(TRAPS) {
805 assert(is_loaded(), "must be loaded");
806 if (!is_linked()) {
807 link_class_impl(CHECK_false);
808 }
809 return is_linked();
810 }
811
812 bool InstanceKlass::link_class_impl(TRAPS) {
813 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
814 // This is for CDS static dump only -- we use the in_error_state to indicate that
815 // the class has failed verification. Throwing the NoClassDefFoundError here is just
816 // a convenient way to stop repeat attempts to verify the same (bad) class.
817 //
818 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
819 // if we are executing Java code. This is not a problem for CDS dumping phase since
820 // it doesn't execute any Java code.
821 ResourceMark rm(THREAD);
822 Exceptions::fthrow(THREAD_AND_LOCATION,
823 vmSymbols::java_lang_NoClassDefFoundError(),
824 "Class %s, or one of its supertypes, failed class initialization",
825 external_name());
826 return false;
827 }
828 // return if already verified
829 if (is_linked()) {
830 return true;
831 }
832
833 // Timing
834 // timer handles recursion
835 JavaThread* jt = THREAD;
836
837 // link super class before linking this class
838 Klass* super_klass = super();
839 if (super_klass != nullptr) {
840 if (super_klass->is_interface()) { // check if super class is an interface
841 ResourceMark rm(THREAD);
842 Exceptions::fthrow(
843 THREAD_AND_LOCATION,
844 vmSymbols::java_lang_IncompatibleClassChangeError(),
845 "class %s has interface %s as super class",
846 external_name(),
847 super_klass->external_name()
848 );
849 return false;
850 }
851
852 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
853 ik_super->link_class_impl(CHECK_false);
854 }
855
856 // link all interfaces implemented by this class before linking this class
857 Array<InstanceKlass*>* interfaces = local_interfaces();
858 int num_interfaces = interfaces->length();
859 for (int index = 0; index < num_interfaces; index++) {
860 InstanceKlass* interk = interfaces->at(index);
861 interk->link_class_impl(CHECK_false);
862 }
863
864 // in case the class is linked in the process of linking its superclasses
865 if (is_linked()) {
866 return true;
867 }
868
869 // trace only the link time for this klass that includes
870 // the verification time
871 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
872 ClassLoader::perf_class_link_selftime(),
873 ClassLoader::perf_classes_linked(),
874 jt->get_thread_stat()->perf_recursion_counts_addr(),
875 jt->get_thread_stat()->perf_timers_addr(),
876 PerfClassTraceTime::CLASS_LINK);
877
878 // verification & rewriting
879 {
880 HandleMark hm(THREAD);
881 Handle h_init_lock(THREAD, init_lock());
882 ObjectLocker ol(h_init_lock, jt);
883 // rewritten will have been set if loader constraint error found
884 // on an earlier link attempt
885 // don't verify or rewrite if already rewritten
886 //
887
888 if (!is_linked()) {
889 if (!is_rewritten()) {
890 if (is_shared()) {
891 assert(!verified_at_dump_time(), "must be");
892 }
893 {
894 bool verify_ok = verify_code(THREAD);
895 if (!verify_ok) {
896 return false;
897 }
898 }
899
900 // Just in case a side-effect of verify linked this class already
901 // (which can sometimes happen since the verifier loads classes
902 // using custom class loaders, which are free to initialize things)
903 if (is_linked()) {
904 return true;
905 }
906
907 // also sets rewritten
908 rewrite_class(CHECK_false);
909 } else if (is_shared()) {
910 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
911 }
912
913 // relocate jsrs and link methods after they are all rewritten
914 link_methods(CHECK_false);
915
916 // Initialize the vtable and interface table after
917 // methods have been rewritten since rewrite may
918 // fabricate new Method*s.
919 // also does loader constraint checking
920 //
921 // initialize_vtable and initialize_itable need to be rerun
922 // for a shared class if
923 // 1) the class is loaded by custom class loader or
924 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
925 // 3) the class was not verified during dump time
926 bool need_init_table = true;
927 if (is_shared() && verified_at_dump_time() &&
928 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
929 need_init_table = false;
930 }
931 if (need_init_table) {
932 vtable().initialize_vtable_and_check_constraints(CHECK_false);
933 itable().initialize_itable_and_check_constraints(CHECK_false);
934 }
935 #ifdef ASSERT
936 vtable().verify(tty, true);
937 // In case itable verification is ever added.
938 // itable().verify(tty, true);
939 #endif
940 if (Universe::is_fully_initialized()) {
941 DeoptimizationScope deopt_scope;
942 {
943 // Now mark all code that assumes the class is not linked.
944 // Set state under the Compile_lock also.
945 MutexLocker ml(THREAD, Compile_lock);
946
947 set_init_state(linked);
948 CodeCache::mark_dependents_on(&deopt_scope, this);
949 }
950 // Perform the deopt handshake outside Compile_lock.
951 deopt_scope.deoptimize_marked();
952 } else {
953 set_init_state(linked);
954 }
955 if (JvmtiExport::should_post_class_prepare()) {
956 JvmtiExport::post_class_prepare(THREAD, this);
957 }
958 }
959 }
960 return true;
961 }
962
963 // Rewrite the byte codes of all of the methods of a class.
964 // The rewriter must be called exactly once. Rewriting must happen after
965 // verification but before the first method of the class is executed.
966 void InstanceKlass::rewrite_class(TRAPS) {
967 assert(is_loaded(), "must be loaded");
968 if (is_rewritten()) {
969 assert(is_shared(), "rewriting an unshared class?");
970 return;
971 }
972 Rewriter::rewrite(this, CHECK);
973 set_rewritten();
974 }
975
976 // Now relocate and link method entry points after class is rewritten.
977 // This is outside is_rewritten flag. In case of an exception, it can be
978 // executed more than once.
979 void InstanceKlass::link_methods(TRAPS) {
980 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
981
982 int len = methods()->length();
983 for (int i = len-1; i >= 0; i--) {
984 methodHandle m(THREAD, methods()->at(i));
985
986 // Set up method entry points for compiler and interpreter .
987 m->link_method(m, CHECK);
988 }
989 }
990
991 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
992 void InstanceKlass::initialize_super_interfaces(TRAPS) {
993 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
994 for (int i = 0; i < local_interfaces()->length(); ++i) {
995 InstanceKlass* ik = local_interfaces()->at(i);
996
997 // Initialization is depth first search ie. we start with top of the inheritance tree
998 // has_nonstatic_concrete_methods drives searching superinterfaces since it
999 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1000 if (ik->has_nonstatic_concrete_methods()) {
1001 ik->initialize_super_interfaces(CHECK);
1002 }
1003
1004 // Only initialize() interfaces that "declare" concrete methods.
1005 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1006 ik->initialize(CHECK);
1007 }
1008 }
1009 }
1010
1011 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1012 static InitializationErrorTable* _initialization_error_table;
1013
1014 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1015 // Create the same exception with a message indicating the thread name,
1016 // and the StackTraceElements.
1017 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1018 ResourceMark rm(current);
1019 if (init_error.is_null()) {
1020 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1021
1022 // We failed to create the new exception, most likely due to either out-of-memory or
1023 // a stackoverflow error. If the original exception was either of those then we save
1024 // the shared, pre-allocated, stackless, instance of that exception.
1025 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1026 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1027 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1028 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1029 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1030 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1031 } else {
1032 return;
1033 }
1034 }
1035
1036 MutexLocker ml(current, ClassInitError_lock);
1037 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1038 bool created;
1039 if (_initialization_error_table == nullptr) {
1040 _initialization_error_table = new (mtClass) InitializationErrorTable();
1041 }
1042 _initialization_error_table->put_if_absent(this, elem, &created);
1043 assert(created, "Initialization is single threaded");
1044 log_trace(class, init)("Initialization error added for class %s", external_name());
1045 }
1046
1047 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1048 MutexLocker ml(current, ClassInitError_lock);
1049 if (_initialization_error_table == nullptr) {
1050 return nullptr;
1051 }
1052 OopHandle* h = _initialization_error_table->get(this);
1053 return (h != nullptr) ? h->resolve() : nullptr;
1054 }
1055
1056 // Need to remove entries for unloaded classes.
1057 void InstanceKlass::clean_initialization_error_table() {
1058 struct InitErrorTableCleaner {
1059 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1060 if (!ik->is_loader_alive()) {
1061 h.release(Universe::vm_global());
1062 return true;
1063 } else {
1064 return false;
1065 }
1066 }
1067 };
1068
1069 assert_locked_or_safepoint(ClassInitError_lock);
1070 InitErrorTableCleaner cleaner;
1071 if (_initialization_error_table != nullptr) {
1072 _initialization_error_table->unlink(&cleaner);
1073 }
1074 }
1075
1076 void InstanceKlass::initialize_impl(TRAPS) {
1077 HandleMark hm(THREAD);
1078
1079 // Make sure klass is linked (verified) before initialization
1080 // A class could already be verified, since it has been reflected upon.
1081 link_class(CHECK);
1082
1083 DTRACE_CLASSINIT_PROBE(required, -1);
1084
1085 bool wait = false;
1086
1087 JavaThread* jt = THREAD;
1088
1089 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1090
1091 // refer to the JVM book page 47 for description of steps
1092 // Step 1
1093 {
1094 Handle h_init_lock(THREAD, init_lock());
1095 ObjectLocker ol(h_init_lock, jt);
1096
1097 // Step 2
1098 // If we were to use wait() instead of waitInterruptibly() then
1099 // we might end up throwing IE from link/symbol resolution sites
1100 // that aren't expected to throw. This would wreak havoc. See 6320309.
1101 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1102 if (debug_logging_enabled) {
1103 ResourceMark rm(jt);
1104 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1105 jt->name(), external_name(), init_thread_name());
1106 }
1107 wait = true;
1108 jt->set_class_to_be_initialized(this);
1109 ol.wait_uninterruptibly(jt);
1110 jt->set_class_to_be_initialized(nullptr);
1111 }
1112
1113 // Step 3
1114 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1115 if (debug_logging_enabled) {
1116 ResourceMark rm(jt);
1117 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1118 jt->name(), external_name());
1119 }
1120 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1121 return;
1122 }
1123
1124 // Step 4
1125 if (is_initialized()) {
1126 if (debug_logging_enabled) {
1127 ResourceMark rm(jt);
1128 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1129 jt->name(), external_name());
1130 }
1131 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1132 return;
1133 }
1134
1135 // Step 5
1136 if (is_in_error_state()) {
1137 if (debug_logging_enabled) {
1138 ResourceMark rm(jt);
1139 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1140 jt->name(), external_name());
1141 }
1142
1143 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1144 ResourceMark rm(THREAD);
1145 Handle cause(THREAD, get_initialization_error(THREAD));
1146
1147 stringStream ss;
1148 ss.print("Could not initialize class %s", external_name());
1149 if (cause.is_null()) {
1150 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1151 } else {
1152 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1153 ss.as_string(), cause);
1154 }
1155 } else {
1156
1157 // Step 6
1158 set_init_state(being_initialized);
1159 set_init_thread(jt);
1160 if (debug_logging_enabled) {
1161 ResourceMark rm(jt);
1162 log_debug(class, init)("Thread \"%s\" is initializing %s",
1163 jt->name(), external_name());
1164 }
1165 }
1166 }
1167
1168 // Step 7
1169 // Next, if C is a class rather than an interface, initialize it's super class and super
1170 // interfaces.
1171 if (!is_interface()) {
1172 Klass* super_klass = super();
1173 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1174 super_klass->initialize(THREAD);
1175 }
1176 // If C implements any interface that declares a non-static, concrete method,
1177 // the initialization of C triggers initialization of its super interfaces.
1178 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1179 // having a superinterface that declares, non-static, concrete methods
1180 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1181 initialize_super_interfaces(THREAD);
1182 }
1183
1184 // If any exceptions, complete abruptly, throwing the same exception as above.
1185 if (HAS_PENDING_EXCEPTION) {
1186 Handle e(THREAD, PENDING_EXCEPTION);
1187 CLEAR_PENDING_EXCEPTION;
1188 {
1189 EXCEPTION_MARK;
1190 add_initialization_error(THREAD, e);
1191 // Locks object, set state, and notify all waiting threads
1192 set_initialization_state_and_notify(initialization_error, THREAD);
1193 CLEAR_PENDING_EXCEPTION;
1194 }
1195 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1196 THROW_OOP(e());
1197 }
1198 }
1199
1200
1201 // Step 8
1202 {
1203 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1204 if (class_initializer() != nullptr) {
1205 // Timer includes any side effects of class initialization (resolution,
1206 // etc), but not recursive entry into call_class_initializer().
1207 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1208 ClassLoader::perf_class_init_selftime(),
1209 ClassLoader::perf_classes_inited(),
1210 jt->get_thread_stat()->perf_recursion_counts_addr(),
1211 jt->get_thread_stat()->perf_timers_addr(),
1212 PerfClassTraceTime::CLASS_CLINIT);
1213 call_class_initializer(THREAD);
1214 } else {
1215 // The elapsed time is so small it's not worth counting.
1216 if (UsePerfData) {
1217 ClassLoader::perf_classes_inited()->inc();
1218 }
1219 call_class_initializer(THREAD);
1220 }
1221 }
1222
1223 // Step 9
1224 if (!HAS_PENDING_EXCEPTION) {
1225 set_initialization_state_and_notify(fully_initialized, CHECK);
1226 debug_only(vtable().verify(tty, true);)
1227 }
1228 else {
1229 // Step 10 and 11
1230 Handle e(THREAD, PENDING_EXCEPTION);
1231 CLEAR_PENDING_EXCEPTION;
1232 // JVMTI has already reported the pending exception
1233 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1234 JvmtiExport::clear_detected_exception(jt);
1235 {
1236 EXCEPTION_MARK;
1237 add_initialization_error(THREAD, e);
1238 set_initialization_state_and_notify(initialization_error, THREAD);
1239 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1240 // JVMTI has already reported the pending exception
1241 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1242 JvmtiExport::clear_detected_exception(jt);
1243 }
1244 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1245 if (e->is_a(vmClasses::Error_klass())) {
1246 THROW_OOP(e());
1247 } else {
1248 JavaCallArguments args(e);
1249 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1250 vmSymbols::throwable_void_signature(),
1251 &args);
1252 }
1253 }
1254 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1255 }
1256
1257
1258 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1259 Handle h_init_lock(THREAD, init_lock());
1260 if (h_init_lock() != nullptr) {
1261 ObjectLocker ol(h_init_lock, THREAD);
1262 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1263 set_init_state(state);
1264 fence_and_clear_init_lock();
1265 ol.notify_all(CHECK);
1266 } else {
1267 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1268 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1269 set_init_state(state);
1270 }
1271 }
1272
1273 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1274 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1275 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1276 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1277
1278 DeoptimizationScope deopt_scope;
1279 {
1280 MutexLocker ml(current, Compile_lock);
1281
1282 set_init_state(InstanceKlass::loaded);
1283 // make sure init_state store is already done.
1284 // The compiler reads the hierarchy outside of the Compile_lock.
1285 // Access ordering is used to add to hierarchy.
1286
1287 // Link into hierarchy.
1288 append_to_sibling_list(); // add to superklass/sibling list
1289 process_interfaces(); // handle all "implements" declarations
1290
1291 // Now mark all code that depended on old class hierarchy.
1292 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1293 if (Universe::is_fully_initialized()) {
1294 CodeCache::mark_dependents_on(&deopt_scope, this);
1295 }
1296 }
1297 // Perform the deopt handshake outside Compile_lock.
1298 deopt_scope.deoptimize_marked();
1299 }
1300
1301
1302 InstanceKlass* InstanceKlass::implementor() const {
1303 InstanceKlass* volatile* ik = adr_implementor();
1304 if (ik == nullptr) {
1305 return nullptr;
1306 } else {
1307 // This load races with inserts, and therefore needs acquire.
1308 InstanceKlass* ikls = Atomic::load_acquire(ik);
1309 if (ikls != nullptr && !ikls->is_loader_alive()) {
1310 return nullptr; // don't return unloaded class
1311 } else {
1312 return ikls;
1313 }
1314 }
1315 }
1316
1317
1318 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1319 assert_locked_or_safepoint(Compile_lock);
1320 assert(is_interface(), "not interface");
1321 InstanceKlass* volatile* addr = adr_implementor();
1322 assert(addr != nullptr, "null addr");
1323 if (addr != nullptr) {
1324 Atomic::release_store(addr, ik);
1325 }
1326 }
1327
1328 int InstanceKlass::nof_implementors() const {
1329 InstanceKlass* ik = implementor();
1330 if (ik == nullptr) {
1331 return 0;
1332 } else if (ik != this) {
1333 return 1;
1334 } else {
1335 return 2;
1336 }
1337 }
1338
1339 // The embedded _implementor field can only record one implementor.
1340 // When there are more than one implementors, the _implementor field
1341 // is set to the interface Klass* itself. Following are the possible
1342 // values for the _implementor field:
1343 // null - no implementor
1344 // implementor Klass* - one implementor
1345 // self - more than one implementor
1346 //
1347 // The _implementor field only exists for interfaces.
1348 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1349 if (Universe::is_fully_initialized()) {
1350 assert_lock_strong(Compile_lock);
1351 }
1352 assert(is_interface(), "not interface");
1353 // Filter out my subinterfaces.
1354 // (Note: Interfaces are never on the subklass list.)
1355 if (ik->is_interface()) return;
1356
1357 // Filter out subclasses whose supers already implement me.
1358 // (Note: CHA must walk subclasses of direct implementors
1359 // in order to locate indirect implementors.)
1360 InstanceKlass* super_ik = ik->java_super();
1361 if (super_ik != nullptr && super_ik->implements_interface(this))
1362 // We only need to check one immediate superclass, since the
1363 // implements_interface query looks at transitive_interfaces.
1364 // Any supers of the super have the same (or fewer) transitive_interfaces.
1365 return;
1366
1367 InstanceKlass* iklass = implementor();
1368 if (iklass == nullptr) {
1369 set_implementor(ik);
1370 } else if (iklass != this && iklass != ik) {
1371 // There is already an implementor. Use itself as an indicator of
1372 // more than one implementors.
1373 set_implementor(this);
1374 }
1375
1376 // The implementor also implements the transitive_interfaces
1377 for (int index = 0; index < local_interfaces()->length(); index++) {
1378 local_interfaces()->at(index)->add_implementor(ik);
1379 }
1380 }
1381
1382 void InstanceKlass::init_implementor() {
1383 if (is_interface()) {
1384 set_implementor(nullptr);
1385 }
1386 }
1387
1388
1389 void InstanceKlass::process_interfaces() {
1390 // link this class into the implementors list of every interface it implements
1391 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1392 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1393 InstanceKlass* interf = local_interfaces()->at(i);
1394 assert(interf->is_interface(), "expected interface");
1395 interf->add_implementor(this);
1396 }
1397 }
1398
1399 bool InstanceKlass::can_be_primary_super_slow() const {
1400 if (is_interface())
1401 return false;
1402 else
1403 return Klass::can_be_primary_super_slow();
1404 }
1405
1406 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1407 Array<InstanceKlass*>* transitive_interfaces) {
1408 // The secondaries are the implemented interfaces.
1409 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1410 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1411 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1412 int num_secondaries = num_extra_slots + interfaces->length();
1413 if (num_secondaries == 0) {
1414 // Must share this for correct bootstrapping!
1415 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1416 return nullptr;
1417 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1418 // We will reuse the transitive interfaces list if we're certain
1419 // it's in hash order.
1420 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1421 set_secondary_supers(interfaces, bitmap);
1422 return nullptr;
1423 }
1424 // Copy transitive interfaces to a temporary growable array to be constructed
1425 // into the secondary super list with extra slots.
1426 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1427 for (int i = 0; i < interfaces->length(); i++) {
1428 secondaries->push(interfaces->at(i));
1429 }
1430 return secondaries;
1431 }
1432
1433 bool InstanceKlass::implements_interface(Klass* k) const {
1434 if (this == k) return true;
1435 assert(k->is_interface(), "should be an interface class");
1436 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1437 if (transitive_interfaces()->at(i) == k) {
1438 return true;
1439 }
1440 }
1441 return false;
1442 }
1443
1444 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1445 // Verify direct super interface
1446 if (this == k) return true;
1447 assert(k->is_interface(), "should be an interface class");
1448 for (int i = 0; i < local_interfaces()->length(); i++) {
1449 if (local_interfaces()->at(i) == k) {
1450 return true;
1451 }
1452 }
1453 return false;
1454 }
1455
1456 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1457 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1458 size_t size = objArrayOopDesc::object_size(length);
1459 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1460 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1461 /* do_zero */ true, CHECK_NULL);
1462 return o;
1463 }
1464
1465 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1466 if (TraceFinalizerRegistration) {
1467 tty->print("Registered ");
1468 i->print_value_on(tty);
1469 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1470 }
1471 instanceHandle h_i(THREAD, i);
1472 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1473 JavaValue result(T_VOID);
1474 JavaCallArguments args(h_i);
1475 methodHandle mh(THREAD, Universe::finalizer_register_method());
1476 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1477 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1478 return h_i();
1479 }
1480
1481 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1482 assert(!is_abstract() && !is_interface(), "Should not create this object");
1483 size_t size = size_helper(); // Query before forming handle.
1484 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1485 }
1486
1487 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1488 Klass* k = java_lang_Class::as_Klass(java_class);
1489 if (k == nullptr) {
1490 ResourceMark rm(THREAD);
1491 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1492 }
1493 InstanceKlass* ik = cast(k);
1494 ik->check_valid_for_instantiation(false, CHECK_NULL);
1495 ik->initialize(CHECK_NULL);
1496 return ik->allocate_instance(THREAD);
1497 }
1498
1499 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1500 return instanceHandle(THREAD, allocate_instance(THREAD));
1501 }
1502
1503 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1504 if (is_interface() || is_abstract()) {
1505 ResourceMark rm(THREAD);
1506 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1507 : vmSymbols::java_lang_InstantiationException(), external_name());
1508 }
1509 if (this == vmClasses::Class_klass()) {
1510 ResourceMark rm(THREAD);
1511 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1512 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1513 }
1514 }
1515
1516 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1517 // Need load-acquire for lock-free read
1518 if (array_klasses_acquire() == nullptr) {
1519
1520 // Recursively lock array allocation
1521 RecursiveLocker rl(MultiArray_lock, THREAD);
1522
1523 // Check if another thread created the array klass while we were waiting for the lock.
1524 if (array_klasses() == nullptr) {
1525 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1526 // use 'release' to pair with lock-free load
1527 release_set_array_klasses(k);
1528 }
1529 }
1530
1531 // array_klasses() will always be set at this point
1532 ObjArrayKlass* ak = array_klasses();
1533 assert(ak != nullptr, "should be set");
1534 return ak->array_klass(n, THREAD);
1535 }
1536
1537 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1538 // Need load-acquire for lock-free read
1539 ObjArrayKlass* oak = array_klasses_acquire();
1540 if (oak == nullptr) {
1541 return nullptr;
1542 } else {
1543 return oak->array_klass_or_null(n);
1544 }
1545 }
1546
1547 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1548 return array_klass(1, THREAD);
1549 }
1550
1551 ArrayKlass* InstanceKlass::array_klass_or_null() {
1552 return array_klass_or_null(1);
1553 }
1554
1555 static int call_class_initializer_counter = 0; // for debugging
1556
1557 Method* InstanceKlass::class_initializer() const {
1558 Method* clinit = find_method(
1559 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1560 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1561 return clinit;
1562 }
1563 return nullptr;
1564 }
1565
1566 void InstanceKlass::call_class_initializer(TRAPS) {
1567 if (ReplayCompiles &&
1568 (ReplaySuppressInitializers == 1 ||
1569 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1570 // Hide the existence of the initializer for the purpose of replaying the compile
1571 return;
1572 }
1573
1574 #if INCLUDE_CDS
1575 // This is needed to ensure the consistency of the archived heap objects.
1576 if (has_archived_enum_objs()) {
1577 assert(is_shared(), "must be");
1578 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1579 if (initialized) {
1580 return;
1581 }
1582 }
1583 #endif
1584
1585 methodHandle h_method(THREAD, class_initializer());
1586 assert(!is_initialized(), "we cannot initialize twice");
1587 LogTarget(Info, class, init) lt;
1588 if (lt.is_enabled()) {
1589 ResourceMark rm(THREAD);
1590 LogStream ls(lt);
1591 ls.print("%d Initializing ", call_class_initializer_counter++);
1592 name()->print_value_on(&ls);
1593 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1594 h_method() == nullptr ? "(no method)" : "", p2i(this),
1595 THREAD->name());
1596 }
1597 if (h_method() != nullptr) {
1598 JavaCallArguments args; // No arguments
1599 JavaValue result(T_VOID);
1600 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1601 }
1602 }
1603
1604
1605 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1606 InterpreterOopMap* entry_for) {
1607 // Lazily create the _oop_map_cache at first request.
1608 // Load_acquire is needed to safely get instance published with CAS by another thread.
1609 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1610 if (oop_map_cache == nullptr) {
1611 // Try to install new instance atomically.
1612 oop_map_cache = new OopMapCache();
1613 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1614 if (other != nullptr) {
1615 // Someone else managed to install before us, ditch local copy and use the existing one.
1616 delete oop_map_cache;
1617 oop_map_cache = other;
1618 }
1619 }
1620 // _oop_map_cache is constant after init; lookup below does its own locking.
1621 oop_map_cache->lookup(method, bci, entry_for);
1622 }
1623
1624 bool InstanceKlass::contains_field_offset(int offset) {
1625 fieldDescriptor fd;
1626 return find_field_from_offset(offset, false, &fd);
1627 }
1628
1629 FieldInfo InstanceKlass::field(int index) const {
1630 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1631 if (fs.index() == index) {
1632 return fs.to_FieldInfo();
1633 }
1634 }
1635 fatal("Field not found");
1636 return FieldInfo();
1637 }
1638
1639 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1640 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1641 Symbol* f_name = fs.name();
1642 Symbol* f_sig = fs.signature();
1643 if (f_name == name && f_sig == sig) {
1644 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1645 return true;
1646 }
1647 }
1648 return false;
1649 }
1650
1651
1652 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1653 const int n = local_interfaces()->length();
1654 for (int i = 0; i < n; i++) {
1655 Klass* intf1 = local_interfaces()->at(i);
1656 assert(intf1->is_interface(), "just checking type");
1657 // search for field in current interface
1658 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1659 assert(fd->is_static(), "interface field must be static");
1660 return intf1;
1661 }
1662 // search for field in direct superinterfaces
1663 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1664 if (intf2 != nullptr) return intf2;
1665 }
1666 // otherwise field lookup fails
1667 return nullptr;
1668 }
1669
1670
1671 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1672 // search order according to newest JVM spec (5.4.3.2, p.167).
1673 // 1) search for field in current klass
1674 if (find_local_field(name, sig, fd)) {
1675 return const_cast<InstanceKlass*>(this);
1676 }
1677 // 2) search for field recursively in direct superinterfaces
1678 { Klass* intf = find_interface_field(name, sig, fd);
1679 if (intf != nullptr) return intf;
1680 }
1681 // 3) apply field lookup recursively if superclass exists
1682 { Klass* supr = super();
1683 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1684 }
1685 // 4) otherwise field lookup fails
1686 return nullptr;
1687 }
1688
1689
1690 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1691 // search order according to newest JVM spec (5.4.3.2, p.167).
1692 // 1) search for field in current klass
1693 if (find_local_field(name, sig, fd)) {
1694 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1695 }
1696 // 2) search for field recursively in direct superinterfaces
1697 if (is_static) {
1698 Klass* intf = find_interface_field(name, sig, fd);
1699 if (intf != nullptr) return intf;
1700 }
1701 // 3) apply field lookup recursively if superclass exists
1702 { Klass* supr = super();
1703 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1704 }
1705 // 4) otherwise field lookup fails
1706 return nullptr;
1707 }
1708
1709
1710 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1711 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1712 if (fs.offset() == offset) {
1713 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1714 if (fd->is_static() == is_static) return true;
1715 }
1716 }
1717 return false;
1718 }
1719
1720
1721 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1722 Klass* klass = const_cast<InstanceKlass*>(this);
1723 while (klass != nullptr) {
1724 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1725 return true;
1726 }
1727 klass = klass->super();
1728 }
1729 return false;
1730 }
1731
1732
1733 void InstanceKlass::methods_do(void f(Method* method)) {
1734 // Methods aren't stable until they are loaded. This can be read outside
1735 // a lock through the ClassLoaderData for profiling
1736 // Redefined scratch classes are on the list and need to be cleaned
1737 if (!is_loaded() && !is_scratch_class()) {
1738 return;
1739 }
1740
1741 int len = methods()->length();
1742 for (int index = 0; index < len; index++) {
1743 Method* m = methods()->at(index);
1744 assert(m->is_method(), "must be method");
1745 f(m);
1746 }
1747 }
1748
1749
1750 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1751 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1752 if (fs.access_flags().is_static()) {
1753 fieldDescriptor& fd = fs.field_descriptor();
1754 cl->do_field(&fd);
1755 }
1756 }
1757 }
1758
1759
1760 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1761 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1762 if (fs.access_flags().is_static()) {
1763 fieldDescriptor& fd = fs.field_descriptor();
1764 f(&fd, mirror, CHECK);
1765 }
1766 }
1767 }
1768
1769 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1770 InstanceKlass* super = superklass();
1771 if (super != nullptr) {
1772 super->do_nonstatic_fields(cl);
1773 }
1774 fieldDescriptor fd;
1775 int length = java_fields_count();
1776 for (int i = 0; i < length; i += 1) {
1777 fd.reinitialize(this, i);
1778 if (!fd.is_static()) {
1779 cl->do_field(&fd);
1780 }
1781 }
1782 }
1783
1784 // first in Pair is offset, second is index.
1785 static int compare_fields_by_offset(Pair<int,int>* a, Pair<int,int>* b) {
1786 return a->first - b->first;
1787 }
1788
1789 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1790 InstanceKlass* super = superklass();
1791 if (super != nullptr) {
1792 super->print_nonstatic_fields(cl);
1793 }
1794 ResourceMark rm;
1795 fieldDescriptor fd;
1796 // In DebugInfo nonstatic fields are sorted by offset.
1797 GrowableArray<Pair<int,int> > fields_sorted;
1798 int i = 0;
1799 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1800 if (!fs.access_flags().is_static()) {
1801 fd = fs.field_descriptor();
1802 Pair<int,int> f(fs.offset(), fs.index());
1803 fields_sorted.push(f);
1804 i++;
1805 }
1806 }
1807 if (i > 0) {
1808 int length = i;
1809 assert(length == fields_sorted.length(), "duh");
1810 fields_sorted.sort(compare_fields_by_offset);
1811 for (int i = 0; i < length; i++) {
1812 fd.reinitialize(this, fields_sorted.at(i).second);
1813 assert(!fd.is_static() && fd.offset() == fields_sorted.at(i).first, "only nonstatic fields");
1814 cl->do_field(&fd);
1815 }
1816 }
1817 }
1818
1819 #ifdef ASSERT
1820 static int linear_search(const Array<Method*>* methods,
1821 const Symbol* name,
1822 const Symbol* signature) {
1823 const int len = methods->length();
1824 for (int index = 0; index < len; index++) {
1825 const Method* const m = methods->at(index);
1826 assert(m->is_method(), "must be method");
1827 if (m->signature() == signature && m->name() == name) {
1828 return index;
1829 }
1830 }
1831 return -1;
1832 }
1833 #endif
1834
1835 bool InstanceKlass::_disable_method_binary_search = false;
1836
1837 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1838 int len = methods->length();
1839 int l = 0;
1840 int h = len - 1;
1841 while (l <= h) {
1842 Method* m = methods->at(l);
1843 if (m->name() == name) {
1844 return l;
1845 }
1846 l++;
1847 }
1848 return -1;
1849 }
1850
1851 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1852 if (_disable_method_binary_search) {
1853 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1854 // At the final stage of dynamic dumping, the methods array may not be sorted
1855 // by ascending addresses of their names, so we can't use binary search anymore.
1856 // However, methods with the same name are still laid out consecutively inside the
1857 // methods array, so let's look for the first one that matches.
1858 return linear_search(methods, name);
1859 }
1860
1861 int len = methods->length();
1862 int l = 0;
1863 int h = len - 1;
1864
1865 // methods are sorted by ascending addresses of their names, so do binary search
1866 while (l <= h) {
1867 int mid = (l + h) >> 1;
1868 Method* m = methods->at(mid);
1869 assert(m->is_method(), "must be method");
1870 int res = m->name()->fast_compare(name);
1871 if (res == 0) {
1872 return mid;
1873 } else if (res < 0) {
1874 l = mid + 1;
1875 } else {
1876 h = mid - 1;
1877 }
1878 }
1879 return -1;
1880 }
1881
1882 // find_method looks up the name/signature in the local methods array
1883 Method* InstanceKlass::find_method(const Symbol* name,
1884 const Symbol* signature) const {
1885 return find_method_impl(name, signature,
1886 OverpassLookupMode::find,
1887 StaticLookupMode::find,
1888 PrivateLookupMode::find);
1889 }
1890
1891 Method* InstanceKlass::find_method_impl(const Symbol* name,
1892 const Symbol* signature,
1893 OverpassLookupMode overpass_mode,
1894 StaticLookupMode static_mode,
1895 PrivateLookupMode private_mode) const {
1896 return InstanceKlass::find_method_impl(methods(),
1897 name,
1898 signature,
1899 overpass_mode,
1900 static_mode,
1901 private_mode);
1902 }
1903
1904 // find_instance_method looks up the name/signature in the local methods array
1905 // and skips over static methods
1906 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1907 const Symbol* name,
1908 const Symbol* signature,
1909 PrivateLookupMode private_mode) {
1910 Method* const meth = InstanceKlass::find_method_impl(methods,
1911 name,
1912 signature,
1913 OverpassLookupMode::find,
1914 StaticLookupMode::skip,
1915 private_mode);
1916 assert(((meth == nullptr) || !meth->is_static()),
1917 "find_instance_method should have skipped statics");
1918 return meth;
1919 }
1920
1921 // find_instance_method looks up the name/signature in the local methods array
1922 // and skips over static methods
1923 Method* InstanceKlass::find_instance_method(const Symbol* name,
1924 const Symbol* signature,
1925 PrivateLookupMode private_mode) const {
1926 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1927 }
1928
1929 // Find looks up the name/signature in the local methods array
1930 // and filters on the overpass, static and private flags
1931 // This returns the first one found
1932 // note that the local methods array can have up to one overpass, one static
1933 // and one instance (private or not) with the same name/signature
1934 Method* InstanceKlass::find_local_method(const Symbol* name,
1935 const Symbol* signature,
1936 OverpassLookupMode overpass_mode,
1937 StaticLookupMode static_mode,
1938 PrivateLookupMode private_mode) const {
1939 return InstanceKlass::find_method_impl(methods(),
1940 name,
1941 signature,
1942 overpass_mode,
1943 static_mode,
1944 private_mode);
1945 }
1946
1947 // Find looks up the name/signature in the local methods array
1948 // and filters on the overpass, static and private flags
1949 // This returns the first one found
1950 // note that the local methods array can have up to one overpass, one static
1951 // and one instance (private or not) with the same name/signature
1952 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1953 const Symbol* name,
1954 const Symbol* signature,
1955 OverpassLookupMode overpass_mode,
1956 StaticLookupMode static_mode,
1957 PrivateLookupMode private_mode) {
1958 return InstanceKlass::find_method_impl(methods,
1959 name,
1960 signature,
1961 overpass_mode,
1962 static_mode,
1963 private_mode);
1964 }
1965
1966 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1967 const Symbol* name,
1968 const Symbol* signature) {
1969 return InstanceKlass::find_method_impl(methods,
1970 name,
1971 signature,
1972 OverpassLookupMode::find,
1973 StaticLookupMode::find,
1974 PrivateLookupMode::find);
1975 }
1976
1977 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1978 const Symbol* name,
1979 const Symbol* signature,
1980 OverpassLookupMode overpass_mode,
1981 StaticLookupMode static_mode,
1982 PrivateLookupMode private_mode) {
1983 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1984 return hit >= 0 ? methods->at(hit): nullptr;
1985 }
1986
1987 // true if method matches signature and conforms to skipping_X conditions.
1988 static bool method_matches(const Method* m,
1989 const Symbol* signature,
1990 bool skipping_overpass,
1991 bool skipping_static,
1992 bool skipping_private) {
1993 return ((m->signature() == signature) &&
1994 (!skipping_overpass || !m->is_overpass()) &&
1995 (!skipping_static || !m->is_static()) &&
1996 (!skipping_private || !m->is_private()));
1997 }
1998
1999 // Used directly for default_methods to find the index into the
2000 // default_vtable_indices, and indirectly by find_method
2001 // find_method_index looks in the local methods array to return the index
2002 // of the matching name/signature. If, overpass methods are being ignored,
2003 // the search continues to find a potential non-overpass match. This capability
2004 // is important during method resolution to prefer a static method, for example,
2005 // over an overpass method.
2006 // There is the possibility in any _method's array to have the same name/signature
2007 // for a static method, an overpass method and a local instance method
2008 // To correctly catch a given method, the search criteria may need
2009 // to explicitly skip the other two. For local instance methods, it
2010 // is often necessary to skip private methods
2011 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2012 const Symbol* name,
2013 const Symbol* signature,
2014 OverpassLookupMode overpass_mode,
2015 StaticLookupMode static_mode,
2016 PrivateLookupMode private_mode) {
2017 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2018 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2019 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2020 const int hit = quick_search(methods, name);
2021 if (hit != -1) {
2022 const Method* const m = methods->at(hit);
2023
2024 // Do linear search to find matching signature. First, quick check
2025 // for common case, ignoring overpasses if requested.
2026 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2027 return hit;
2028 }
2029
2030 // search downwards through overloaded methods
2031 int i;
2032 for (i = hit - 1; i >= 0; --i) {
2033 const Method* const m = methods->at(i);
2034 assert(m->is_method(), "must be method");
2035 if (m->name() != name) {
2036 break;
2037 }
2038 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2039 return i;
2040 }
2041 }
2042 // search upwards
2043 for (i = hit + 1; i < methods->length(); ++i) {
2044 const Method* const m = methods->at(i);
2045 assert(m->is_method(), "must be method");
2046 if (m->name() != name) {
2047 break;
2048 }
2049 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2050 return i;
2051 }
2052 }
2053 // not found
2054 #ifdef ASSERT
2055 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2056 linear_search(methods, name, signature);
2057 assert(-1 == index, "binary search should have found entry %d", index);
2058 #endif
2059 }
2060 return -1;
2061 }
2062
2063 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2064 return find_method_by_name(methods(), name, end);
2065 }
2066
2067 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2068 const Symbol* name,
2069 int* end_ptr) {
2070 assert(end_ptr != nullptr, "just checking");
2071 int start = quick_search(methods, name);
2072 int end = start + 1;
2073 if (start != -1) {
2074 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2075 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2076 *end_ptr = end;
2077 return start;
2078 }
2079 return -1;
2080 }
2081
2082 // uncached_lookup_method searches both the local class methods array and all
2083 // superclasses methods arrays, skipping any overpass methods in superclasses,
2084 // and possibly skipping private methods.
2085 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2086 const Symbol* signature,
2087 OverpassLookupMode overpass_mode,
2088 PrivateLookupMode private_mode) const {
2089 OverpassLookupMode overpass_local_mode = overpass_mode;
2090 const Klass* klass = this;
2091 while (klass != nullptr) {
2092 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2093 signature,
2094 overpass_local_mode,
2095 StaticLookupMode::find,
2096 private_mode);
2097 if (method != nullptr) {
2098 return method;
2099 }
2100 klass = klass->super();
2101 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2102 }
2103 return nullptr;
2104 }
2105
2106 #ifdef ASSERT
2107 // search through class hierarchy and return true if this class or
2108 // one of the superclasses was redefined
2109 bool InstanceKlass::has_redefined_this_or_super() const {
2110 const Klass* klass = this;
2111 while (klass != nullptr) {
2112 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2113 return true;
2114 }
2115 klass = klass->super();
2116 }
2117 return false;
2118 }
2119 #endif
2120
2121 // lookup a method in the default methods list then in all transitive interfaces
2122 // Do NOT return private or static methods
2123 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2124 Symbol* signature) const {
2125 Method* m = nullptr;
2126 if (default_methods() != nullptr) {
2127 m = find_method(default_methods(), name, signature);
2128 }
2129 // Look up interfaces
2130 if (m == nullptr) {
2131 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2132 }
2133 return m;
2134 }
2135
2136 // lookup a method in all the interfaces that this class implements
2137 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2138 // They should only be found in the initial InterfaceMethodRef
2139 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2140 Symbol* signature,
2141 DefaultsLookupMode defaults_mode) const {
2142 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2143 int num_ifs = all_ifs->length();
2144 InstanceKlass *ik = nullptr;
2145 for (int i = 0; i < num_ifs; i++) {
2146 ik = all_ifs->at(i);
2147 Method* m = ik->lookup_method(name, signature);
2148 if (m != nullptr && m->is_public() && !m->is_static() &&
2149 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2150 return m;
2151 }
2152 }
2153 return nullptr;
2154 }
2155
2156 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2157 :_st(st), _verbose(verbose) {
2158 ResourceMark rm;
2159 _st->print("%-18s ", "KlassAddr");
2160 _st->print("%-4s ", "Size");
2161 _st->print("%-20s ", "State");
2162 _st->print("%-7s ", "Flags");
2163 _st->print("%-5s ", "ClassName");
2164 _st->cr();
2165 }
2166
2167 void PrintClassClosure::do_klass(Klass* k) {
2168 ResourceMark rm;
2169 // klass pointer
2170 _st->print(PTR_FORMAT " ", p2i(k));
2171 // klass size
2172 _st->print("%4d ", k->size());
2173 // initialization state
2174 if (k->is_instance_klass()) {
2175 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2176 } else {
2177 _st->print("%-20s ","");
2178 }
2179 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2180 char buf[10];
2181 int i = 0;
2182 if (k->has_finalizer()) buf[i++] = 'F';
2183 if (k->is_instance_klass()) {
2184 InstanceKlass* ik = InstanceKlass::cast(k);
2185 if (ik->has_final_method()) buf[i++] = 'f';
2186 if (ik->is_rewritten()) buf[i++] = 'W';
2187 if (ik->is_contended()) buf[i++] = 'C';
2188 if (ik->has_been_redefined()) buf[i++] = 'R';
2189 if (ik->is_shared()) buf[i++] = 'S';
2190 }
2191 buf[i++] = '\0';
2192 _st->print("%-7s ", buf);
2193 // klass name
2194 _st->print("%-5s ", k->external_name());
2195 // end
2196 _st->cr();
2197 if (_verbose) {
2198 k->print_on(_st);
2199 }
2200 }
2201
2202 /* jni_id_for for jfieldIds only */
2203 JNIid* InstanceKlass::jni_id_for(int offset) {
2204 MutexLocker ml(JfieldIdCreation_lock);
2205 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2206 if (probe == nullptr) {
2207 // Allocate new static field identifier
2208 probe = new JNIid(this, offset, jni_ids());
2209 set_jni_ids(probe);
2210 }
2211 return probe;
2212 }
2213
2214 u2 InstanceKlass::enclosing_method_data(int offset) const {
2215 const Array<jushort>* const inner_class_list = inner_classes();
2216 if (inner_class_list == nullptr) {
2217 return 0;
2218 }
2219 const int length = inner_class_list->length();
2220 if (length % inner_class_next_offset == 0) {
2221 return 0;
2222 }
2223 const int index = length - enclosing_method_attribute_size;
2224 assert(offset < enclosing_method_attribute_size, "invalid offset");
2225 return inner_class_list->at(index + offset);
2226 }
2227
2228 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2229 u2 method_index) {
2230 Array<jushort>* inner_class_list = inner_classes();
2231 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2232 int length = inner_class_list->length();
2233 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2234 int index = length - enclosing_method_attribute_size;
2235 inner_class_list->at_put(
2236 index + enclosing_method_class_index_offset, class_index);
2237 inner_class_list->at_put(
2238 index + enclosing_method_method_index_offset, method_index);
2239 }
2240 }
2241
2242 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2243 if (method->is_old() && !method->is_obsolete()) {
2244 // If the method passed in is old (but not obsolete), use the current version.
2245 method = method_with_idnum((int)idnum);
2246 assert(method != nullptr, "old and but not obsolete, so should exist");
2247 }
2248 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2249 Atomic::release_store(&jmeths[idnum + 1], new_id);
2250 return new_id;
2251 }
2252
2253 // Lookup or create a jmethodID.
2254 // This code is called by the VMThread and JavaThreads so the
2255 // locking has to be done very carefully to avoid deadlocks
2256 // and/or other cache consistency problems.
2257 //
2258 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2259 Method* method = method_h();
2260 int idnum = method->method_idnum();
2261 jmethodID* jmeths = methods_jmethod_ids_acquire();
2262
2263 // We use a double-check locking idiom here because this cache is
2264 // performance sensitive. In the normal system, this cache only
2265 // transitions from null to non-null which is safe because we use
2266 // release_set_methods_jmethod_ids() to advertise the new cache.
2267 // A partially constructed cache should never be seen by a racing
2268 // thread. We also use release_store() to save a new jmethodID
2269 // in the cache so a partially constructed jmethodID should never be
2270 // seen either. Cache reads of existing jmethodIDs proceed without a
2271 // lock, but cache writes of a new jmethodID requires uniqueness and
2272 // creation of the cache itself requires no leaks so a lock is
2273 // acquired in those two cases.
2274 //
2275 // If the RedefineClasses() API has been used, then this cache grows
2276 // in the redefinition safepoint.
2277
2278 if (jmeths == nullptr) {
2279 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2280 jmeths = methods_jmethod_ids_acquire();
2281 // Still null?
2282 if (jmeths == nullptr) {
2283 size_t size = idnum_allocated_count();
2284 assert(size > (size_t)idnum, "should already have space");
2285 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2286 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2287 // cache size is stored in element[0], other elements offset by one
2288 jmeths[0] = (jmethodID)size;
2289 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2290
2291 // publish jmeths
2292 release_set_methods_jmethod_ids(jmeths);
2293 return new_id;
2294 }
2295 }
2296
2297 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2298 if (id == nullptr) {
2299 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2300 id = jmeths[idnum + 1];
2301 // Still null?
2302 if (id == nullptr) {
2303 return update_jmethod_id(jmeths, method, idnum);
2304 }
2305 }
2306 return id;
2307 }
2308
2309 void InstanceKlass::update_methods_jmethod_cache() {
2310 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2311 jmethodID* cache = _methods_jmethod_ids;
2312 if (cache != nullptr) {
2313 size_t size = idnum_allocated_count();
2314 size_t old_size = (size_t)cache[0];
2315 if (old_size < size + 1) {
2316 // Allocate a larger one and copy entries to the new one.
2317 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2318 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2319 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2320 // The cache size is stored in element[0]; the other elements are offset by one.
2321 new_cache[0] = (jmethodID)size;
2322
2323 for (int i = 1; i <= (int)old_size; i++) {
2324 new_cache[i] = cache[i];
2325 }
2326 _methods_jmethod_ids = new_cache;
2327 FREE_C_HEAP_ARRAY(jmethodID, cache);
2328 }
2329 }
2330 }
2331
2332 // Figure out how many jmethodIDs haven't been allocated, and make
2333 // sure space for them is pre-allocated. This makes getting all
2334 // method ids much, much faster with classes with more than 8
2335 // methods, and has a *substantial* effect on performance with jvmti
2336 // code that loads all jmethodIDs for all classes.
2337 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2338 int new_jmeths = 0;
2339 int length = methods()->length();
2340 for (int index = start_offset; index < length; index++) {
2341 Method* m = methods()->at(index);
2342 jmethodID id = m->find_jmethod_id_or_null();
2343 if (id == nullptr) {
2344 new_jmeths++;
2345 }
2346 }
2347 if (new_jmeths != 0) {
2348 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2349 }
2350 }
2351
2352 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2353 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2354 int idnum = method->method_idnum();
2355 jmethodID* jmeths = methods_jmethod_ids_acquire();
2356 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2357 }
2358
2359 inline DependencyContext InstanceKlass::dependencies() {
2360 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2361 return dep_context;
2362 }
2363
2364 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2365 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2366 }
2367
2368 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2369 dependencies().add_dependent_nmethod(nm);
2370 }
2371
2372 void InstanceKlass::clean_dependency_context() {
2373 dependencies().clean_unloading_dependents();
2374 }
2375
2376 #ifndef PRODUCT
2377 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2378 dependencies().print_dependent_nmethods(verbose);
2379 }
2380
2381 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2382 return dependencies().is_dependent_nmethod(nm);
2383 }
2384 #endif //PRODUCT
2385
2386 void InstanceKlass::clean_weak_instanceklass_links() {
2387 clean_implementors_list();
2388 clean_method_data();
2389 }
2390
2391 void InstanceKlass::clean_implementors_list() {
2392 assert(is_loader_alive(), "this klass should be live");
2393 if (is_interface()) {
2394 assert (ClassUnloading, "only called for ClassUnloading");
2395 for (;;) {
2396 // Use load_acquire due to competing with inserts
2397 InstanceKlass* volatile* iklass = adr_implementor();
2398 assert(iklass != nullptr, "Klass must not be null");
2399 InstanceKlass* impl = Atomic::load_acquire(iklass);
2400 if (impl != nullptr && !impl->is_loader_alive()) {
2401 // null this field, might be an unloaded instance klass or null
2402 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2403 // Successfully unlinking implementor.
2404 if (log_is_enabled(Trace, class, unload)) {
2405 ResourceMark rm;
2406 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2407 }
2408 return;
2409 }
2410 } else {
2411 return;
2412 }
2413 }
2414 }
2415 }
2416
2417 void InstanceKlass::clean_method_data() {
2418 for (int m = 0; m < methods()->length(); m++) {
2419 MethodData* mdo = methods()->at(m)->method_data();
2420 if (mdo != nullptr) {
2421 mdo->clean_method_data(/*always_clean*/false);
2422 }
2423 }
2424 }
2425
2426 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2427 Klass::metaspace_pointers_do(it);
2428
2429 if (log_is_enabled(Trace, cds)) {
2430 ResourceMark rm;
2431 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2432 }
2433
2434 it->push(&_annotations);
2435 it->push((Klass**)&_array_klasses);
2436 if (!is_rewritten()) {
2437 it->push(&_constants, MetaspaceClosure::_writable);
2438 } else {
2439 it->push(&_constants);
2440 }
2441 it->push(&_inner_classes);
2442 #if INCLUDE_JVMTI
2443 it->push(&_previous_versions);
2444 #endif
2445 #if INCLUDE_CDS
2446 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2447 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2448 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2449 // The length check on the _methods is necessary because classes which don't have any
2450 // methods share the Universe::_the_empty_method_array which is in the RO region.
2451 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2452 // To handle jsr bytecode, new Method* maybe stored into _methods
2453 it->push(&_methods, MetaspaceClosure::_writable);
2454 } else {
2455 #endif
2456 it->push(&_methods);
2457 #if INCLUDE_CDS
2458 }
2459 #endif
2460 it->push(&_default_methods);
2461 it->push(&_local_interfaces);
2462 it->push(&_transitive_interfaces);
2463 it->push(&_method_ordering);
2464 if (!is_rewritten()) {
2465 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2466 } else {
2467 it->push(&_default_vtable_indices);
2468 }
2469
2470 it->push(&_fieldinfo_stream);
2471 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2472 it->push(&_fields_status, MetaspaceClosure::_writable);
2473
2474 if (itable_length() > 0) {
2475 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2476 int method_table_offset_in_words = ioe->offset()/wordSize;
2477 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2478
2479 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2480 / itableOffsetEntry::size();
2481
2482 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2483 if (ioe->interface_klass() != nullptr) {
2484 it->push(ioe->interface_klass_addr());
2485 itableMethodEntry* ime = ioe->first_method_entry(this);
2486 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2487 for (int index = 0; index < n; index ++) {
2488 it->push(ime[index].method_addr());
2489 }
2490 }
2491 }
2492 }
2493
2494 it->push(&_nest_members);
2495 it->push(&_permitted_subclasses);
2496 it->push(&_record_components);
2497 }
2498
2499 #if INCLUDE_CDS
2500 void InstanceKlass::remove_unshareable_info() {
2501
2502 if (is_linked()) {
2503 assert(can_be_verified_at_dumptime(), "must be");
2504 // Remember this so we can avoid walking the hierarchy at runtime.
2505 set_verified_at_dump_time();
2506 }
2507
2508 Klass::remove_unshareable_info();
2509
2510 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2511 // Classes are attempted to link during dumping and may fail,
2512 // but these classes are still in the dictionary and class list in CLD.
2513 // If the class has failed verification, there is nothing else to remove.
2514 return;
2515 }
2516
2517 // Reset to the 'allocated' state to prevent any premature accessing to
2518 // a shared class at runtime while the class is still being loaded and
2519 // restored. A class' init_state is set to 'loaded' at runtime when it's
2520 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2521 _init_state = allocated;
2522
2523 { // Otherwise this needs to take out the Compile_lock.
2524 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2525 init_implementor();
2526 }
2527
2528 // Call remove_unshareable_info() on other objects that belong to this class, except
2529 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2530 // ArchiveBuilder::make_klasses_shareable(),
2531
2532 for (int i = 0; i < methods()->length(); i++) {
2533 Method* m = methods()->at(i);
2534 m->remove_unshareable_info();
2535 }
2536
2537 // do array classes also.
2538 if (array_klasses() != nullptr) {
2539 array_klasses()->remove_unshareable_info();
2540 }
2541
2542 // These are not allocated from metaspace. They are safe to set to null.
2543 _source_debug_extension = nullptr;
2544 _dep_context = nullptr;
2545 _osr_nmethods_head = nullptr;
2546 #if INCLUDE_JVMTI
2547 _breakpoints = nullptr;
2548 _previous_versions = nullptr;
2549 _cached_class_file = nullptr;
2550 _jvmti_cached_class_field_map = nullptr;
2551 #endif
2552
2553 _init_thread = nullptr;
2554 _methods_jmethod_ids = nullptr;
2555 _jni_ids = nullptr;
2556 _oop_map_cache = nullptr;
2557 // clear _nest_host to ensure re-load at runtime
2558 _nest_host = nullptr;
2559 init_shared_package_entry();
2560 _dep_context_last_cleaned = 0;
2561
2562 remove_unshareable_flags();
2563 }
2564
2565 void InstanceKlass::remove_unshareable_flags() {
2566 // clear all the flags/stats that shouldn't be in the archived version
2567 assert(!is_scratch_class(), "must be");
2568 assert(!has_been_redefined(), "must be");
2569 #if INCLUDE_JVMTI
2570 set_is_being_redefined(false);
2571 #endif
2572 set_has_resolved_methods(false);
2573 }
2574
2575 void InstanceKlass::remove_java_mirror() {
2576 Klass::remove_java_mirror();
2577
2578 // do array classes also.
2579 if (array_klasses() != nullptr) {
2580 array_klasses()->remove_java_mirror();
2581 }
2582 }
2583
2584 void InstanceKlass::init_shared_package_entry() {
2585 assert(CDSConfig::is_dumping_archive(), "must be");
2586 #if !INCLUDE_CDS_JAVA_HEAP
2587 _package_entry = nullptr;
2588 #else
2589 if (CDSConfig::is_dumping_full_module_graph()) {
2590 if (is_shared_unregistered_class()) {
2591 _package_entry = nullptr;
2592 } else {
2593 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2594 }
2595 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2596 CDSConfig::is_using_full_module_graph() &&
2597 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2598 // _package_entry is an archived package in the base archive. Leave it as is.
2599 } else {
2600 _package_entry = nullptr;
2601 }
2602 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2603 #endif
2604 }
2605
2606 void InstanceKlass::compute_has_loops_flag_for_methods() {
2607 Array<Method*>* methods = this->methods();
2608 for (int index = 0; index < methods->length(); ++index) {
2609 Method* m = methods->at(index);
2610 if (!m->is_overpass()) { // work around JDK-8305771
2611 m->compute_has_loops_flag();
2612 }
2613 }
2614 }
2615
2616 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2617 PackageEntry* pkg_entry, TRAPS) {
2618 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2619 // before the InstanceKlass is added to the SystemDictionary. Make
2620 // sure the current state is <loaded.
2621 assert(!is_loaded(), "invalid init state");
2622 assert(!shared_loading_failed(), "Must not try to load failed class again");
2623 set_package(loader_data, pkg_entry, CHECK);
2624 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2625
2626 Array<Method*>* methods = this->methods();
2627 int num_methods = methods->length();
2628 for (int index = 0; index < num_methods; ++index) {
2629 methods->at(index)->restore_unshareable_info(CHECK);
2630 }
2631 #if INCLUDE_JVMTI
2632 if (JvmtiExport::has_redefined_a_class()) {
2633 // Reinitialize vtable because RedefineClasses may have changed some
2634 // entries in this vtable for super classes so the CDS vtable might
2635 // point to old or obsolete entries. RedefineClasses doesn't fix up
2636 // vtables in the shared system dictionary, only the main one.
2637 // It also redefines the itable too so fix that too.
2638 // First fix any default methods that point to a super class that may
2639 // have been redefined.
2640 bool trace_name_printed = false;
2641 adjust_default_methods(&trace_name_printed);
2642 vtable().initialize_vtable();
2643 itable().initialize_itable();
2644 }
2645 #endif
2646
2647 // restore constant pool resolved references
2648 constants()->restore_unshareable_info(CHECK);
2649
2650 if (array_klasses() != nullptr) {
2651 // To get a consistent list of classes we need MultiArray_lock to ensure
2652 // array classes aren't observed while they are being restored.
2653 RecursiveLocker rl(MultiArray_lock, THREAD);
2654 assert(this == array_klasses()->bottom_klass(), "sanity");
2655 // Array classes have null protection domain.
2656 // --> see ArrayKlass::complete_create_array_klass()
2657 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2658 }
2659
2660 // Initialize @ValueBased class annotation if not already set in the archived klass.
2661 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2662 set_is_value_based();
2663 }
2664 }
2665
2666 // Check if a class or any of its supertypes has a version older than 50.
2667 // CDS will not perform verification of old classes during dump time because
2668 // without changing the old verifier, the verification constraint cannot be
2669 // retrieved during dump time.
2670 // Verification of archived old classes will be performed during run time.
2671 bool InstanceKlass::can_be_verified_at_dumptime() const {
2672 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2673 // This is a class that was dumped into the base archive, so we know
2674 // it was verified at dump time.
2675 return true;
2676 }
2677 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2678 return false;
2679 }
2680 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2681 return false;
2682 }
2683 Array<InstanceKlass*>* interfaces = local_interfaces();
2684 int len = interfaces->length();
2685 for (int i = 0; i < len; i++) {
2686 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2687 return false;
2688 }
2689 }
2690 return true;
2691 }
2692 #endif // INCLUDE_CDS
2693
2694 #if INCLUDE_JVMTI
2695 static void clear_all_breakpoints(Method* m) {
2696 m->clear_all_breakpoints();
2697 }
2698 #endif
2699
2700 void InstanceKlass::unload_class(InstanceKlass* ik) {
2701
2702 if (ik->is_scratch_class()) {
2703 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2704 return;
2705 }
2706 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2707
2708 // Release dependencies.
2709 ik->dependencies().remove_all_dependents();
2710
2711 // notify the debugger
2712 if (JvmtiExport::should_post_class_unload()) {
2713 JvmtiExport::post_class_unload(ik);
2714 }
2715
2716 // notify ClassLoadingService of class unload
2717 ClassLoadingService::notify_class_unloaded(ik);
2718
2719 SystemDictionaryShared::handle_class_unloading(ik);
2720
2721 if (log_is_enabled(Info, class, unload)) {
2722 ResourceMark rm;
2723 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2724 }
2725
2726 Events::log_class_unloading(Thread::current(), ik);
2727
2728 #if INCLUDE_JFR
2729 assert(ik != nullptr, "invariant");
2730 EventClassUnload event;
2731 event.set_unloadedClass(ik);
2732 event.set_definingClassLoader(ik->class_loader_data());
2733 event.commit();
2734 #endif
2735 }
2736
2737 static void method_release_C_heap_structures(Method* m) {
2738 m->release_C_heap_structures();
2739 }
2740
2741 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2742 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2743 // Clean up C heap
2744 Klass::release_C_heap_structures();
2745
2746 // Deallocate and call destructors for MDO mutexes
2747 if (release_sub_metadata) {
2748 methods_do(method_release_C_heap_structures);
2749 }
2750
2751 // Deallocate oop map cache
2752 if (_oop_map_cache != nullptr) {
2753 delete _oop_map_cache;
2754 _oop_map_cache = nullptr;
2755 }
2756
2757 // Deallocate JNI identifiers for jfieldIDs
2758 JNIid::deallocate(jni_ids());
2759 set_jni_ids(nullptr);
2760
2761 jmethodID* jmeths = methods_jmethod_ids_acquire();
2762 if (jmeths != nullptr) {
2763 release_set_methods_jmethod_ids(nullptr);
2764 FreeHeap(jmeths);
2765 }
2766
2767 assert(_dep_context == nullptr,
2768 "dependencies should already be cleaned");
2769
2770 #if INCLUDE_JVMTI
2771 // Deallocate breakpoint records
2772 if (breakpoints() != nullptr) {
2773 methods_do(clear_all_breakpoints);
2774 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2775 }
2776
2777 // deallocate the cached class file
2778 if (_cached_class_file != nullptr) {
2779 os::free(_cached_class_file);
2780 _cached_class_file = nullptr;
2781 }
2782 #endif
2783
2784 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2785
2786 if (release_sub_metadata) {
2787 constants()->release_C_heap_structures();
2788 }
2789 }
2790
2791 // The constant pool is on stack if any of the methods are executing or
2792 // referenced by handles.
2793 bool InstanceKlass::on_stack() const {
2794 return _constants->on_stack();
2795 }
2796
2797 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2798 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2799 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2800
2801 // minor and major version numbers of class file
2802 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2803 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2804 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2805 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2806
2807 InstanceKlass* InstanceKlass::get_klass_version(int version) {
2808 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2809 if (ik->constants()->version() == version) {
2810 return ik;
2811 }
2812 }
2813 return nullptr;
2814 }
2815
2816 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2817 if (array == nullptr) {
2818 _source_debug_extension = nullptr;
2819 } else {
2820 // Adding one to the attribute length in order to store a null terminator
2821 // character could cause an overflow because the attribute length is
2822 // already coded with an u4 in the classfile, but in practice, it's
2823 // unlikely to happen.
2824 assert((length+1) > length, "Overflow checking");
2825 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2826 for (int i = 0; i < length; i++) {
2827 sde[i] = array[i];
2828 }
2829 sde[length] = '\0';
2830 _source_debug_extension = sde;
2831 }
2832 }
2833
2834 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
2835 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
2836 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
2837
2838 const char* InstanceKlass::signature_name() const {
2839
2840 // Get the internal name as a c string
2841 const char* src = (const char*) (name()->as_C_string());
2842 const int src_length = (int)strlen(src);
2843
2844 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
2845
2846 // Add L as type indicator
2847 int dest_index = 0;
2848 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2849
2850 // Add the actual class name
2851 for (int src_index = 0; src_index < src_length; ) {
2852 dest[dest_index++] = src[src_index++];
2853 }
2854
2855 if (is_hidden()) { // Replace the last '+' with a '.'.
2856 for (int index = (int)src_length; index > 0; index--) {
2857 if (dest[index] == '+') {
2858 dest[index] = JVM_SIGNATURE_DOT;
2859 break;
2860 }
2861 }
2862 }
2863
2864 // Add the semicolon and the null
2865 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2866 dest[dest_index] = '\0';
2867 return dest;
2868 }
2869
2870 ModuleEntry* InstanceKlass::module() const {
2871 if (is_hidden() &&
2872 in_unnamed_package() &&
2873 class_loader_data()->has_class_mirror_holder()) {
2874 // For a non-strong hidden class defined to an unnamed package,
2875 // its (class held) CLD will not have an unnamed module created for it.
2876 // Two choices to find the correct ModuleEntry:
2877 // 1. If hidden class is within a nest, use nest host's module
2878 // 2. Find the unnamed module off from the class loader
2879 // For now option #2 is used since a nest host is not set until
2880 // after the instance class is created in jvm_lookup_define_class().
2881 if (class_loader_data()->is_boot_class_loader_data()) {
2882 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2883 } else {
2884 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2885 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2886 return java_lang_Module::module_entry(module);
2887 }
2888 }
2889
2890 // Class is in a named package
2891 if (!in_unnamed_package()) {
2892 return _package_entry->module();
2893 }
2894
2895 // Class is in an unnamed package, return its loader's unnamed module
2896 return class_loader_data()->unnamed_module();
2897 }
2898
2899 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
2900
2901 // ensure java/ packages only loaded by boot or platform builtin loaders
2902 // not needed for shared class since CDS does not archive prohibited classes.
2903 if (!is_shared()) {
2904 check_prohibited_package(name(), loader_data, CHECK);
2905 }
2906
2907 if (is_shared() && _package_entry != nullptr) {
2908 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
2909 // we can use the saved package
2910 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
2911 return;
2912 } else {
2913 _package_entry = nullptr;
2914 }
2915 }
2916
2917 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
2918 // it returns, so we need to decrement it when the current function exits.
2919 TempNewSymbol from_class_name =
2920 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
2921
2922 Symbol* pkg_name;
2923 if (pkg_entry != nullptr) {
2924 pkg_name = pkg_entry->name();
2925 } else {
2926 pkg_name = from_class_name;
2927 }
2928
2929 if (pkg_name != nullptr && loader_data != nullptr) {
2930
2931 // Find in class loader's package entry table.
2932 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
2933
2934 // If the package name is not found in the loader's package
2935 // entry table, it is an indication that the package has not
2936 // been defined. Consider it defined within the unnamed module.
2937 if (_package_entry == nullptr) {
2938
2939 if (!ModuleEntryTable::javabase_defined()) {
2940 // Before java.base is defined during bootstrapping, define all packages in
2941 // the java.base module. If a non-java.base package is erroneously placed
2942 // in the java.base module it will be caught later when java.base
2943 // is defined by ModuleEntryTable::verify_javabase_packages check.
2944 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
2945 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2946 } else {
2947 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
2948 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
2949 }
2950
2951 // A package should have been successfully created
2952 DEBUG_ONLY(ResourceMark rm(THREAD));
2953 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
2954 name()->as_C_string(), loader_data->loader_name_and_id());
2955 }
2956
2957 if (log_is_enabled(Debug, module)) {
2958 ResourceMark rm(THREAD);
2959 ModuleEntry* m = _package_entry->module();
2960 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2961 external_name(),
2962 pkg_name->as_C_string(),
2963 loader_data->loader_name_and_id(),
2964 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2965 }
2966 } else {
2967 ResourceMark rm(THREAD);
2968 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2969 external_name(),
2970 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
2971 UNNAMED_MODULE);
2972 }
2973 }
2974
2975 // Function set_classpath_index ensures that for a non-null _package_entry
2976 // of the InstanceKlass, the entry is in the boot loader's package entry table.
2977 // It then sets the classpath_index in the package entry record.
2978 //
2979 // The classpath_index field is used to find the entry on the boot loader class
2980 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
2981 // in an unnamed module. It is also used to indicate (for all packages whose
2982 // classes are loaded by the boot loader) that at least one of the package's
2983 // classes has been loaded.
2984 void InstanceKlass::set_classpath_index(s2 path_index) {
2985 if (_package_entry != nullptr) {
2986 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
2987 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
2988 assert(path_index != -1, "Unexpected classpath_index");
2989 _package_entry->set_classpath_index(path_index);
2990 }
2991 }
2992
2993 // different versions of is_same_class_package
2994
2995 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2996 oop classloader1 = this->class_loader();
2997 PackageEntry* classpkg1 = this->package();
2998 if (class2->is_objArray_klass()) {
2999 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3000 }
3001
3002 oop classloader2;
3003 PackageEntry* classpkg2;
3004 if (class2->is_instance_klass()) {
3005 classloader2 = class2->class_loader();
3006 classpkg2 = class2->package();
3007 } else {
3008 assert(class2->is_typeArray_klass(), "should be type array");
3009 classloader2 = nullptr;
3010 classpkg2 = nullptr;
3011 }
3012
3013 // Same package is determined by comparing class loader
3014 // and package entries. Both must be the same. This rule
3015 // applies even to classes that are defined in the unnamed
3016 // package, they still must have the same class loader.
3017 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3018 return true;
3019 }
3020
3021 return false;
3022 }
3023
3024 // return true if this class and other_class are in the same package. Classloader
3025 // and classname information is enough to determine a class's package
3026 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3027 const Symbol* other_class_name) const {
3028 if (class_loader() != other_class_loader) {
3029 return false;
3030 }
3031 if (name()->fast_compare(other_class_name) == 0) {
3032 return true;
3033 }
3034
3035 {
3036 ResourceMark rm;
3037
3038 bool bad_class_name = false;
3039 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3040 if (bad_class_name) {
3041 return false;
3042 }
3043 // Check that package_from_class_name() returns null, not "", if there is no package.
3044 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3045
3046 const Symbol* const this_package_name =
3047 this->package() != nullptr ? this->package()->name() : nullptr;
3048
3049 if (this_package_name == nullptr || other_pkg == nullptr) {
3050 // One of the two doesn't have a package. Only return true if the other
3051 // one also doesn't have a package.
3052 return this_package_name == other_pkg;
3053 }
3054
3055 // Check if package is identical
3056 return this_package_name->fast_compare(other_pkg) == 0;
3057 }
3058 }
3059
3060 static bool is_prohibited_package_slow(Symbol* class_name) {
3061 // Caller has ResourceMark
3062 int length;
3063 jchar* unicode = class_name->as_unicode(length);
3064 return (length >= 5 &&
3065 unicode[0] == 'j' &&
3066 unicode[1] == 'a' &&
3067 unicode[2] == 'v' &&
3068 unicode[3] == 'a' &&
3069 unicode[4] == '/');
3070 }
3071
3072 // Only boot and platform class loaders can define classes in "java/" packages.
3073 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3074 ClassLoaderData* loader_data,
3075 TRAPS) {
3076 if (!loader_data->is_boot_class_loader_data() &&
3077 !loader_data->is_platform_class_loader_data() &&
3078 class_name != nullptr && class_name->utf8_length() >= 5) {
3079 ResourceMark rm(THREAD);
3080 bool prohibited;
3081 const u1* base = class_name->base();
3082 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3083 prohibited = is_prohibited_package_slow(class_name);
3084 } else {
3085 char* name = class_name->as_C_string();
3086 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3087 }
3088 if (prohibited) {
3089 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3090 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3091 char* name = pkg_name->as_C_string();
3092 const char* class_loader_name = loader_data->loader_name_and_id();
3093 StringUtils::replace_no_expand(name, "/", ".");
3094 const char* msg_text1 = "Class loader (instance of): ";
3095 const char* msg_text2 = " tried to load prohibited package name: ";
3096 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3097 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3098 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3099 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3100 }
3101 }
3102 return;
3103 }
3104
3105 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3106 constantPoolHandle i_cp(THREAD, constants());
3107 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3108 int ioff = iter.inner_class_info_index();
3109 if (ioff != 0) {
3110 // Check to see if the name matches the class we're looking for
3111 // before attempting to find the class.
3112 if (i_cp->klass_name_at_matches(this, ioff)) {
3113 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3114 if (this == inner_klass) {
3115 *ooff = iter.outer_class_info_index();
3116 *noff = iter.inner_name_index();
3117 return true;
3118 }
3119 }
3120 }
3121 }
3122 return false;
3123 }
3124
3125 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3126 InstanceKlass* outer_klass = nullptr;
3127 *inner_is_member = false;
3128 int ooff = 0, noff = 0;
3129 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3130 if (has_inner_classes_attr) {
3131 constantPoolHandle i_cp(THREAD, constants());
3132 if (ooff != 0) {
3133 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3134 if (!ok->is_instance_klass()) {
3135 // If the outer class is not an instance klass then it cannot have
3136 // declared any inner classes.
3137 ResourceMark rm(THREAD);
3138 Exceptions::fthrow(
3139 THREAD_AND_LOCATION,
3140 vmSymbols::java_lang_IncompatibleClassChangeError(),
3141 "%s and %s disagree on InnerClasses attribute",
3142 ok->external_name(),
3143 external_name());
3144 return nullptr;
3145 }
3146 outer_klass = InstanceKlass::cast(ok);
3147 *inner_is_member = true;
3148 }
3149 if (nullptr == outer_klass) {
3150 // It may be a local class; try for that.
3151 int encl_method_class_idx = enclosing_method_class_index();
3152 if (encl_method_class_idx != 0) {
3153 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3154 outer_klass = InstanceKlass::cast(ok);
3155 *inner_is_member = false;
3156 }
3157 }
3158 }
3159
3160 // If no inner class attribute found for this class.
3161 if (nullptr == outer_klass) return nullptr;
3162
3163 // Throws an exception if outer klass has not declared k as an inner klass
3164 // We need evidence that each klass knows about the other, or else
3165 // the system could allow a spoof of an inner class to gain access rights.
3166 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3167 return outer_klass;
3168 }
3169
3170 jint InstanceKlass::compute_modifier_flags() const {
3171 jint access = access_flags().as_int();
3172
3173 // But check if it happens to be member class.
3174 InnerClassesIterator iter(this);
3175 for (; !iter.done(); iter.next()) {
3176 int ioff = iter.inner_class_info_index();
3177 // Inner class attribute can be zero, skip it.
3178 // Strange but true: JVM spec. allows null inner class refs.
3179 if (ioff == 0) continue;
3180
3181 // only look at classes that are already loaded
3182 // since we are looking for the flags for our self.
3183 Symbol* inner_name = constants()->klass_name_at(ioff);
3184 if (name() == inner_name) {
3185 // This is really a member class.
3186 access = iter.inner_access_flags();
3187 break;
3188 }
3189 }
3190 // Remember to strip ACC_SUPER bit
3191 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
3192 }
3193
3194 jint InstanceKlass::jvmti_class_status() const {
3195 jint result = 0;
3196
3197 if (is_linked()) {
3198 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3199 }
3200
3201 if (is_initialized()) {
3202 assert(is_linked(), "Class status is not consistent");
3203 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3204 }
3205 if (is_in_error_state()) {
3206 result |= JVMTI_CLASS_STATUS_ERROR;
3207 }
3208 return result;
3209 }
3210
3211 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3212 bool implements_interface; // initialized by method_at_itable_or_null
3213 Method* m = method_at_itable_or_null(holder, index,
3214 implements_interface); // out parameter
3215 if (m != nullptr) {
3216 assert(implements_interface, "sanity");
3217 return m;
3218 } else if (implements_interface) {
3219 // Throw AbstractMethodError since corresponding itable slot is empty.
3220 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3221 } else {
3222 // If the interface isn't implemented by the receiver class,
3223 // the VM should throw IncompatibleClassChangeError.
3224 ResourceMark rm(THREAD);
3225 stringStream ss;
3226 bool same_module = (module() == holder->module());
3227 ss.print("Receiver class %s does not implement "
3228 "the interface %s defining the method to be called "
3229 "(%s%s%s)",
3230 external_name(), holder->external_name(),
3231 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3232 (same_module) ? "" : "; ",
3233 (same_module) ? "" : holder->class_in_module_of_loader());
3234 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3235 }
3236 }
3237
3238 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3239 klassItable itable(this);
3240 for (int i = 0; i < itable.size_offset_table(); i++) {
3241 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3242 if (offset_entry->interface_klass() == holder) {
3243 implements_interface = true;
3244 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3245 Method* m = ime[index].method();
3246 return m;
3247 }
3248 }
3249 implements_interface = false;
3250 return nullptr; // offset entry not found
3251 }
3252
3253 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3254 assert(is_linked(), "required");
3255 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3256 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3257
3258 int vtable_index = Method::invalid_vtable_index;
3259 Symbol* name = intf_method->name();
3260 Symbol* signature = intf_method->signature();
3261
3262 // First check in default method array
3263 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3264 int index = find_method_index(default_methods(),
3265 name, signature,
3266 Klass::OverpassLookupMode::find,
3267 Klass::StaticLookupMode::find,
3268 Klass::PrivateLookupMode::find);
3269 if (index >= 0) {
3270 vtable_index = default_vtable_indices()->at(index);
3271 }
3272 }
3273 if (vtable_index == Method::invalid_vtable_index) {
3274 // get vtable_index for miranda methods
3275 klassVtable vt = vtable();
3276 vtable_index = vt.index_of_miranda(name, signature);
3277 }
3278 return vtable_index;
3279 }
3280
3281 #if INCLUDE_JVMTI
3282 // update default_methods for redefineclasses for methods that are
3283 // not yet in the vtable due to concurrent subclass define and superinterface
3284 // redefinition
3285 // Note: those in the vtable, should have been updated via adjust_method_entries
3286 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3287 // search the default_methods for uses of either obsolete or EMCP methods
3288 if (default_methods() != nullptr) {
3289 for (int index = 0; index < default_methods()->length(); index ++) {
3290 Method* old_method = default_methods()->at(index);
3291 if (old_method == nullptr || !old_method->is_old()) {
3292 continue; // skip uninteresting entries
3293 }
3294 assert(!old_method->is_deleted(), "default methods may not be deleted");
3295 Method* new_method = old_method->get_new_method();
3296 default_methods()->at_put(index, new_method);
3297
3298 if (log_is_enabled(Info, redefine, class, update)) {
3299 ResourceMark rm;
3300 if (!(*trace_name_printed)) {
3301 log_info(redefine, class, update)
3302 ("adjust: klassname=%s default methods from name=%s",
3303 external_name(), old_method->method_holder()->external_name());
3304 *trace_name_printed = true;
3305 }
3306 log_debug(redefine, class, update, vtables)
3307 ("default method update: %s(%s) ",
3308 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3309 }
3310 }
3311 }
3312 }
3313 #endif // INCLUDE_JVMTI
3314
3315 // On-stack replacement stuff
3316 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3317 assert_lock_strong(NMethodState_lock);
3318 #ifndef PRODUCT
3319 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3320 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3321 "redundant OSR recompilation detected. memory leak in CodeCache!");
3322 #endif
3323 // only one compilation can be active
3324 assert(n->is_osr_method(), "wrong kind of nmethod");
3325 n->set_osr_link(osr_nmethods_head());
3326 set_osr_nmethods_head(n);
3327 // Raise the highest osr level if necessary
3328 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3329
3330 // Get rid of the osr methods for the same bci that have lower levels.
3331 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3332 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3333 if (inv != nullptr && inv->is_in_use()) {
3334 inv->make_not_entrant();
3335 }
3336 }
3337 }
3338
3339 // Remove osr nmethod from the list. Return true if found and removed.
3340 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3341 // This is a short non-blocking critical region, so the no safepoint check is ok.
3342 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3343 assert(n->is_osr_method(), "wrong kind of nmethod");
3344 nmethod* last = nullptr;
3345 nmethod* cur = osr_nmethods_head();
3346 int max_level = CompLevel_none; // Find the max comp level excluding n
3347 Method* m = n->method();
3348 // Search for match
3349 bool found = false;
3350 while(cur != nullptr && cur != n) {
3351 if (m == cur->method()) {
3352 // Find max level before n
3353 max_level = MAX2(max_level, cur->comp_level());
3354 }
3355 last = cur;
3356 cur = cur->osr_link();
3357 }
3358 nmethod* next = nullptr;
3359 if (cur == n) {
3360 found = true;
3361 next = cur->osr_link();
3362 if (last == nullptr) {
3363 // Remove first element
3364 set_osr_nmethods_head(next);
3365 } else {
3366 last->set_osr_link(next);
3367 }
3368 }
3369 n->set_osr_link(nullptr);
3370 cur = next;
3371 while (cur != nullptr) {
3372 // Find max level after n
3373 if (m == cur->method()) {
3374 max_level = MAX2(max_level, cur->comp_level());
3375 }
3376 cur = cur->osr_link();
3377 }
3378 m->set_highest_osr_comp_level(max_level);
3379 return found;
3380 }
3381
3382 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3383 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3384 nmethod* osr = osr_nmethods_head();
3385 int found = 0;
3386 while (osr != nullptr) {
3387 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3388 if (osr->method() == m) {
3389 deopt_scope->mark(osr);
3390 found++;
3391 }
3392 osr = osr->osr_link();
3393 }
3394 return found;
3395 }
3396
3397 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3398 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3399 nmethod* osr = osr_nmethods_head();
3400 nmethod* best = nullptr;
3401 while (osr != nullptr) {
3402 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3403 // There can be a time when a c1 osr method exists but we are waiting
3404 // for a c2 version. When c2 completes its osr nmethod we will trash
3405 // the c1 version and only be able to find the c2 version. However
3406 // while we overflow in the c1 code at back branches we don't want to
3407 // try and switch to the same code as we are already running
3408
3409 if (osr->method() == m &&
3410 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3411 if (match_level) {
3412 if (osr->comp_level() == comp_level) {
3413 // Found a match - return it.
3414 return osr;
3415 }
3416 } else {
3417 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3418 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3419 // Found the best possible - return it.
3420 return osr;
3421 }
3422 best = osr;
3423 }
3424 }
3425 }
3426 osr = osr->osr_link();
3427 }
3428
3429 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3430 if (best != nullptr && best->comp_level() >= comp_level) {
3431 return best;
3432 }
3433 return nullptr;
3434 }
3435
3436 // -----------------------------------------------------------------------------------------------------
3437 // Printing
3438
3439 #define BULLET " - "
3440
3441 static const char* state_names[] = {
3442 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3443 };
3444
3445 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3446 for (int i = 0; i < len; i++) {
3447 intptr_t e = start[i];
3448 st->print("%d : " INTPTR_FORMAT, i, e);
3449 if (MetaspaceObj::is_valid((Metadata*)e)) {
3450 st->print(" ");
3451 ((Metadata*)e)->print_value_on(st);
3452 }
3453 st->cr();
3454 }
3455 }
3456
3457 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3458 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3459 }
3460
3461 const char* InstanceKlass::init_state_name() const {
3462 return state_names[init_state()];
3463 }
3464
3465 void InstanceKlass::print_on(outputStream* st) const {
3466 assert(is_klass(), "must be klass");
3467 Klass::print_on(st);
3468
3469 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3470 st->print(BULLET"klass size: %d", size()); st->cr();
3471 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3472 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3473 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3474 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3475 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3476 st->print(BULLET"sub: ");
3477 Klass* sub = subklass();
3478 int n;
3479 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3480 if (n < MaxSubklassPrintSize) {
3481 sub->print_value_on(st);
3482 st->print(" ");
3483 }
3484 }
3485 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3486 st->cr();
3487
3488 if (is_interface()) {
3489 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3490 if (nof_implementors() == 1) {
3491 st->print_cr(BULLET"implementor: ");
3492 st->print(" ");
3493 implementor()->print_value_on(st);
3494 st->cr();
3495 }
3496 }
3497
3498 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3499 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3500 if (Verbose || WizardMode) {
3501 Array<Method*>* method_array = methods();
3502 for (int i = 0; i < method_array->length(); i++) {
3503 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3504 }
3505 }
3506 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3507 if (default_methods() != nullptr) {
3508 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3509 if (Verbose) {
3510 Array<Method*>* method_array = default_methods();
3511 for (int i = 0; i < method_array->length(); i++) {
3512 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3513 }
3514 }
3515 }
3516 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3517 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3518 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3519
3520 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3521
3522 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3523 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3524
3525 if (secondary_supers() != nullptr) {
3526 if (Verbose) {
3527 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3528 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3529 for (int i = 0; i < _secondary_supers->length(); i++) {
3530 ResourceMark rm; // for external_name()
3531 Klass* secondary_super = _secondary_supers->at(i);
3532 st->print(BULLET"%2d:", i);
3533 if (is_hashed) {
3534 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3535 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3536 st->print(" dist:%02d:", distance);
3537 }
3538 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3539 }
3540 }
3541 }
3542 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3543
3544 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3545 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3546 if (source_debug_extension() != nullptr) {
3547 st->print(BULLET"source debug extension: ");
3548 st->print("%s", source_debug_extension());
3549 st->cr();
3550 }
3551 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3552 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3553 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3554 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3555 {
3556 bool have_pv = false;
3557 // previous versions are linked together through the InstanceKlass
3558 for (InstanceKlass* pv_node = previous_versions();
3559 pv_node != nullptr;
3560 pv_node = pv_node->previous_versions()) {
3561 if (!have_pv)
3562 st->print(BULLET"previous version: ");
3563 have_pv = true;
3564 pv_node->constants()->print_value_on(st);
3565 }
3566 if (have_pv) st->cr();
3567 }
3568
3569 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3570 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3571 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3572 print_on_maybe_null(st, BULLET"record components: ", record_components());
3573 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3574 if (java_mirror() != nullptr) {
3575 st->print(BULLET"java mirror: ");
3576 java_mirror()->print_value_on(st);
3577 st->cr();
3578 } else {
3579 st->print_cr(BULLET"java mirror: null");
3580 }
3581 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3582 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3583 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3584 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3585 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3586
3587 FieldPrinter print_static_field(st);
3588 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3589 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3590 FieldPrinter print_nonstatic_field(st);
3591 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3592 ik->print_nonstatic_fields(&print_nonstatic_field);
3593
3594 st->print(BULLET"non-static oop maps: ");
3595 OopMapBlock* map = start_of_nonstatic_oop_maps();
3596 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3597 while (map < end_map) {
3598 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3599 map++;
3600 }
3601 st->cr();
3602 }
3603
3604 void InstanceKlass::print_value_on(outputStream* st) const {
3605 assert(is_klass(), "must be klass");
3606 if (Verbose || WizardMode) access_flags().print_on(st);
3607 name()->print_value_on(st);
3608 }
3609
3610 void FieldPrinter::do_field(fieldDescriptor* fd) {
3611 _st->print(BULLET);
3612 if (_obj == nullptr) {
3613 fd->print_on(_st);
3614 _st->cr();
3615 } else {
3616 fd->print_on_for(_st, _obj);
3617 _st->cr();
3618 }
3619 }
3620
3621
3622 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3623 Klass::oop_print_on(obj, st);
3624
3625 if (this == vmClasses::String_klass()) {
3626 typeArrayOop value = java_lang_String::value(obj);
3627 juint length = java_lang_String::length(obj);
3628 if (value != nullptr &&
3629 value->is_typeArray() &&
3630 length <= (juint) value->length()) {
3631 st->print(BULLET"string: ");
3632 java_lang_String::print(obj, st);
3633 st->cr();
3634 }
3635 }
3636
3637 st->print_cr(BULLET"---- fields (total size " SIZE_FORMAT " words):", oop_size(obj));
3638 FieldPrinter print_field(st, obj);
3639 print_nonstatic_fields(&print_field);
3640
3641 if (this == vmClasses::Class_klass()) {
3642 st->print(BULLET"signature: ");
3643 java_lang_Class::print_signature(obj, st);
3644 st->cr();
3645 Klass* real_klass = java_lang_Class::as_Klass(obj);
3646 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3647 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3648 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3649 }
3650 } else if (this == vmClasses::MethodType_klass()) {
3651 st->print(BULLET"signature: ");
3652 java_lang_invoke_MethodType::print_signature(obj, st);
3653 st->cr();
3654 }
3655 }
3656
3657 #ifndef PRODUCT
3658
3659 bool InstanceKlass::verify_itable_index(int i) {
3660 int method_count = klassItable::method_count_for_interface(this);
3661 assert(i >= 0 && i < method_count, "index out of bounds");
3662 return true;
3663 }
3664
3665 #endif //PRODUCT
3666
3667 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3668 st->print("a ");
3669 name()->print_value_on(st);
3670 obj->print_address_on(st);
3671 if (this == vmClasses::String_klass()
3672 && java_lang_String::value(obj) != nullptr) {
3673 ResourceMark rm;
3674 int len = java_lang_String::length(obj);
3675 int plen = (len < 24 ? len : 12);
3676 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3677 st->print(" = \"%s\"", str);
3678 if (len > plen)
3679 st->print("...[%d]", len);
3680 } else if (this == vmClasses::Class_klass()) {
3681 Klass* k = java_lang_Class::as_Klass(obj);
3682 st->print(" = ");
3683 if (k != nullptr) {
3684 k->print_value_on(st);
3685 } else {
3686 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3687 st->print("%s", tname ? tname : "type?");
3688 }
3689 } else if (this == vmClasses::MethodType_klass()) {
3690 st->print(" = ");
3691 java_lang_invoke_MethodType::print_signature(obj, st);
3692 } else if (java_lang_boxing_object::is_instance(obj)) {
3693 st->print(" = ");
3694 java_lang_boxing_object::print(obj, st);
3695 } else if (this == vmClasses::LambdaForm_klass()) {
3696 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3697 if (vmentry != nullptr) {
3698 st->print(" => ");
3699 vmentry->print_value_on(st);
3700 }
3701 } else if (this == vmClasses::MemberName_klass()) {
3702 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3703 if (vmtarget != nullptr) {
3704 st->print(" = ");
3705 vmtarget->print_value_on(st);
3706 } else {
3707 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3708 oop name = java_lang_invoke_MemberName::name(obj);
3709 if (clazz != nullptr) {
3710 clazz->print_value_on(st);
3711 } else {
3712 st->print("null");
3713 }
3714 st->print(".");
3715 if (name != nullptr) {
3716 name->print_value_on(st);
3717 } else {
3718 st->print("null");
3719 }
3720 }
3721 }
3722 }
3723
3724 const char* InstanceKlass::internal_name() const {
3725 return external_name();
3726 }
3727
3728 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3729 const ModuleEntry* module_entry,
3730 const ClassFileStream* cfs) const {
3731
3732 if (ClassListWriter::is_enabled()) {
3733 ClassListWriter::write(this, cfs);
3734 }
3735
3736 print_class_load_helper(loader_data, module_entry, cfs);
3737 print_class_load_cause_logging();
3738 }
3739
3740 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3741 const ModuleEntry* module_entry,
3742 const ClassFileStream* cfs) const {
3743
3744 if (!log_is_enabled(Info, class, load)) {
3745 return;
3746 }
3747
3748 ResourceMark rm;
3749 LogMessage(class, load) msg;
3750 stringStream info_stream;
3751
3752 // Name and class hierarchy info
3753 info_stream.print("%s", external_name());
3754
3755 // Source
3756 if (cfs != nullptr) {
3757 if (cfs->source() != nullptr) {
3758 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3759 if (module_name != nullptr) {
3760 // When the boot loader created the stream, it didn't know the module name
3761 // yet. Let's format it now.
3762 if (cfs->from_boot_loader_modules_image()) {
3763 info_stream.print(" source: jrt:/%s", module_name);
3764 } else {
3765 info_stream.print(" source: %s", cfs->source());
3766 }
3767 } else {
3768 info_stream.print(" source: %s", cfs->source());
3769 }
3770 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3771 Thread* current = Thread::current();
3772 Klass* caller = current->is_Java_thread() ?
3773 JavaThread::cast(current)->security_get_caller_class(1):
3774 nullptr;
3775 // caller can be null, for example, during a JVMTI VM_Init hook
3776 if (caller != nullptr) {
3777 info_stream.print(" source: instance of %s", caller->external_name());
3778 } else {
3779 // source is unknown
3780 }
3781 } else {
3782 oop class_loader = loader_data->class_loader();
3783 info_stream.print(" source: %s", class_loader->klass()->external_name());
3784 }
3785 } else {
3786 assert(this->is_shared(), "must be");
3787 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3788 info_stream.print(" source: shared objects file (top)");
3789 } else {
3790 info_stream.print(" source: shared objects file");
3791 }
3792 }
3793
3794 msg.info("%s", info_stream.as_string());
3795
3796 if (log_is_enabled(Debug, class, load)) {
3797 stringStream debug_stream;
3798
3799 // Class hierarchy info
3800 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3801 p2i(this), p2i(superklass()));
3802
3803 // Interfaces
3804 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3805 debug_stream.print(" interfaces:");
3806 int length = local_interfaces()->length();
3807 for (int i = 0; i < length; i++) {
3808 debug_stream.print(" " PTR_FORMAT,
3809 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3810 }
3811 }
3812
3813 // Class loader
3814 debug_stream.print(" loader: [");
3815 loader_data->print_value_on(&debug_stream);
3816 debug_stream.print("]");
3817
3818 // Classfile checksum
3819 if (cfs) {
3820 debug_stream.print(" bytes: %d checksum: %08x",
3821 cfs->length(),
3822 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3823 cfs->length()));
3824 }
3825
3826 msg.debug("%s", debug_stream.as_string());
3827 }
3828 }
3829
3830 void InstanceKlass::print_class_load_cause_logging() const {
3831 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
3832 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
3833 JavaThread* current = JavaThread::current();
3834 ResourceMark rm(current);
3835 const char* name = external_name();
3836
3837 if (LogClassLoadingCauseFor == nullptr ||
3838 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
3839 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
3840 return;
3841 }
3842
3843 // Log Java stack first
3844 {
3845 LogMessage(class, load, cause) msg;
3846 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3847
3848 info_stream.print_cr("Java stack when loading %s:", name);
3849 current->print_stack_on(&info_stream);
3850 }
3851
3852 // Log native stack second
3853 if (log_cause_native) {
3854 // Log to string first so that lines can be indented
3855 stringStream stack_stream;
3856 char buf[O_BUFLEN];
3857 address lastpc = nullptr;
3858 if (os::platform_print_native_stack(&stack_stream, nullptr, buf, O_BUFLEN, lastpc)) {
3859 // We have printed the native stack in platform-specific code,
3860 // so nothing else to do in this case.
3861 } else {
3862 frame f = os::current_frame();
3863 VMError::print_native_stack(&stack_stream, f, current, true /*print_source_info */,
3864 -1 /* max stack_stream */, buf, O_BUFLEN);
3865 }
3866
3867 LogMessage(class, load, cause, native) msg;
3868 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
3869 info_stream.print_cr("Native stack when loading %s:", name);
3870
3871 // Print each native stack line to the log
3872 int size = (int) stack_stream.size();
3873 char* stack = stack_stream.as_string();
3874 char* stack_end = stack + size;
3875 char* line_start = stack;
3876 for (char* p = stack; p < stack_end; p++) {
3877 if (*p == '\n') {
3878 *p = '\0';
3879 info_stream.print_cr("\t%s", line_start);
3880 line_start = p + 1;
3881 }
3882 }
3883 if (line_start < stack_end) {
3884 info_stream.print_cr("\t%s", line_start);
3885 }
3886 }
3887 }
3888 }
3889
3890 // Verification
3891
3892 class VerifyFieldClosure: public BasicOopIterateClosure {
3893 protected:
3894 template <class T> void do_oop_work(T* p) {
3895 oop obj = RawAccess<>::oop_load(p);
3896 if (!oopDesc::is_oop_or_null(obj)) {
3897 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3898 Universe::print_on(tty);
3899 guarantee(false, "boom");
3900 }
3901 }
3902 public:
3903 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3904 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3905 };
3906
3907 void InstanceKlass::verify_on(outputStream* st) {
3908 #ifndef PRODUCT
3909 // Avoid redundant verifies, this really should be in product.
3910 if (_verify_count == Universe::verify_count()) return;
3911 _verify_count = Universe::verify_count();
3912 #endif
3913
3914 // Verify Klass
3915 Klass::verify_on(st);
3916
3917 // Verify that klass is present in ClassLoaderData
3918 guarantee(class_loader_data()->contains_klass(this),
3919 "this class isn't found in class loader data");
3920
3921 // Verify vtables
3922 if (is_linked()) {
3923 // $$$ This used to be done only for m/s collections. Doing it
3924 // always seemed a valid generalization. (DLD -- 6/00)
3925 vtable().verify(st);
3926 }
3927
3928 // Verify first subklass
3929 if (subklass() != nullptr) {
3930 guarantee(subklass()->is_klass(), "should be klass");
3931 }
3932
3933 // Verify siblings
3934 Klass* super = this->super();
3935 Klass* sib = next_sibling();
3936 if (sib != nullptr) {
3937 if (sib == this) {
3938 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3939 }
3940
3941 guarantee(sib->is_klass(), "should be klass");
3942 guarantee(sib->super() == super, "siblings should have same superklass");
3943 }
3944
3945 // Verify local interfaces
3946 if (local_interfaces()) {
3947 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3948 for (int j = 0; j < local_interfaces->length(); j++) {
3949 InstanceKlass* e = local_interfaces->at(j);
3950 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3951 }
3952 }
3953
3954 // Verify transitive interfaces
3955 if (transitive_interfaces() != nullptr) {
3956 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3957 for (int j = 0; j < transitive_interfaces->length(); j++) {
3958 InstanceKlass* e = transitive_interfaces->at(j);
3959 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3960 }
3961 }
3962
3963 // Verify methods
3964 if (methods() != nullptr) {
3965 Array<Method*>* methods = this->methods();
3966 for (int j = 0; j < methods->length(); j++) {
3967 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3968 }
3969 for (int j = 0; j < methods->length() - 1; j++) {
3970 Method* m1 = methods->at(j);
3971 Method* m2 = methods->at(j + 1);
3972 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3973 }
3974 }
3975
3976 // Verify method ordering
3977 if (method_ordering() != nullptr) {
3978 Array<int>* method_ordering = this->method_ordering();
3979 int length = method_ordering->length();
3980 if (JvmtiExport::can_maintain_original_method_order() ||
3981 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
3982 guarantee(length == methods()->length(), "invalid method ordering length");
3983 jlong sum = 0;
3984 for (int j = 0; j < length; j++) {
3985 int original_index = method_ordering->at(j);
3986 guarantee(original_index >= 0, "invalid method ordering index");
3987 guarantee(original_index < length, "invalid method ordering index");
3988 sum += original_index;
3989 }
3990 // Verify sum of indices 0,1,...,length-1
3991 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3992 } else {
3993 guarantee(length == 0, "invalid method ordering length");
3994 }
3995 }
3996
3997 // Verify default methods
3998 if (default_methods() != nullptr) {
3999 Array<Method*>* methods = this->default_methods();
4000 for (int j = 0; j < methods->length(); j++) {
4001 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4002 }
4003 for (int j = 0; j < methods->length() - 1; j++) {
4004 Method* m1 = methods->at(j);
4005 Method* m2 = methods->at(j + 1);
4006 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4007 }
4008 }
4009
4010 // Verify JNI static field identifiers
4011 if (jni_ids() != nullptr) {
4012 jni_ids()->verify(this);
4013 }
4014
4015 // Verify other fields
4016 if (constants() != nullptr) {
4017 guarantee(constants()->is_constantPool(), "should be constant pool");
4018 }
4019 }
4020
4021 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4022 Klass::oop_verify_on(obj, st);
4023 VerifyFieldClosure blk;
4024 obj->oop_iterate(&blk);
4025 }
4026
4027
4028 // JNIid class for jfieldIDs only
4029 // Note to reviewers:
4030 // These JNI functions are just moved over to column 1 and not changed
4031 // in the compressed oops workspace.
4032 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4033 _holder = holder;
4034 _offset = offset;
4035 _next = next;
4036 debug_only(_is_static_field_id = false;)
4037 }
4038
4039
4040 JNIid* JNIid::find(int offset) {
4041 JNIid* current = this;
4042 while (current != nullptr) {
4043 if (current->offset() == offset) return current;
4044 current = current->next();
4045 }
4046 return nullptr;
4047 }
4048
4049 void JNIid::deallocate(JNIid* current) {
4050 while (current != nullptr) {
4051 JNIid* next = current->next();
4052 delete current;
4053 current = next;
4054 }
4055 }
4056
4057
4058 void JNIid::verify(Klass* holder) {
4059 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4060 int end_field_offset;
4061 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4062
4063 JNIid* current = this;
4064 while (current != nullptr) {
4065 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4066 #ifdef ASSERT
4067 int o = current->offset();
4068 if (current->is_static_field_id()) {
4069 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4070 }
4071 #endif
4072 current = current->next();
4073 }
4074 }
4075
4076 void InstanceKlass::set_init_state(ClassState state) {
4077 #ifdef ASSERT
4078 bool good_state = is_shared() ? (_init_state <= state)
4079 : (_init_state < state);
4080 assert(good_state || state == allocated, "illegal state transition");
4081 #endif
4082 assert(_init_thread == nullptr, "should be cleared before state change");
4083 Atomic::release_store(&_init_state, state);
4084 }
4085
4086 #if INCLUDE_JVMTI
4087
4088 // RedefineClasses() support for previous versions
4089
4090 // Globally, there is at least one previous version of a class to walk
4091 // during class unloading, which is saved because old methods in the class
4092 // are still running. Otherwise the previous version list is cleaned up.
4093 bool InstanceKlass::_should_clean_previous_versions = false;
4094
4095 // Returns true if there are previous versions of a class for class
4096 // unloading only. Also resets the flag to false. purge_previous_version
4097 // will set the flag to true if there are any left, i.e., if there's any
4098 // work to do for next time. This is to avoid the expensive code cache
4099 // walk in CLDG::clean_deallocate_lists().
4100 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4101 bool ret = _should_clean_previous_versions;
4102 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4103 ret ? "true" : "false");
4104 _should_clean_previous_versions = false;
4105 return ret;
4106 }
4107
4108 // This nulls out jmethodIDs for all methods in 'klass'
4109 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4110 // during class unloading.
4111 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4112 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4113 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4114 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4115 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4116 Array<Method*>* method_refs = klass->methods();
4117 for (int k = 0; k < method_refs->length(); k++) {
4118 Method* method = method_refs->at(k);
4119 if (method != nullptr && method->is_obsolete()) {
4120 method->clear_jmethod_id();
4121 }
4122 }
4123 }
4124
4125 // Purge previous versions before adding new previous versions of the class and
4126 // during class unloading.
4127 void InstanceKlass::purge_previous_version_list() {
4128 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4129 assert(has_been_redefined(), "Should only be called for main class");
4130
4131 // Quick exit.
4132 if (previous_versions() == nullptr) {
4133 return;
4134 }
4135
4136 // This klass has previous versions so see what we can cleanup
4137 // while it is safe to do so.
4138
4139 int deleted_count = 0; // leave debugging breadcrumbs
4140 int live_count = 0;
4141 ClassLoaderData* loader_data = class_loader_data();
4142 assert(loader_data != nullptr, "should never be null");
4143
4144 ResourceMark rm;
4145 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4146
4147 // previous versions are linked together through the InstanceKlass
4148 InstanceKlass* pv_node = previous_versions();
4149 InstanceKlass* last = this;
4150 int version = 0;
4151
4152 // check the previous versions list
4153 for (; pv_node != nullptr; ) {
4154
4155 ConstantPool* pvcp = pv_node->constants();
4156 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4157
4158 if (!pvcp->on_stack()) {
4159 // If the constant pool isn't on stack, none of the methods
4160 // are executing. Unlink this previous_version.
4161 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4162 // so will be deallocated during the next phase of class unloading.
4163 log_trace(redefine, class, iklass, purge)
4164 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4165 // Unlink from previous version list.
4166 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4167 InstanceKlass* next = pv_node->previous_versions();
4168 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4169 pv_node->link_previous_versions(nullptr); // point next to null
4170 last->link_previous_versions(next);
4171 // Delete this node directly. Nothing is referring to it and we don't
4172 // want it to increase the counter for metadata to delete in CLDG.
4173 MetadataFactory::free_metadata(loader_data, pv_node);
4174 pv_node = next;
4175 deleted_count++;
4176 version++;
4177 continue;
4178 } else {
4179 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4180 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4181 live_count++;
4182 if (pvcp->is_shared()) {
4183 // Shared previous versions can never be removed so no cleaning is needed.
4184 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4185 } else {
4186 // Previous version alive, set that clean is needed for next time.
4187 _should_clean_previous_versions = true;
4188 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4189 }
4190 }
4191
4192 // next previous version
4193 last = pv_node;
4194 pv_node = pv_node->previous_versions();
4195 version++;
4196 }
4197 log_trace(redefine, class, iklass, purge)
4198 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4199 }
4200
4201 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4202 int emcp_method_count) {
4203 int obsolete_method_count = old_methods->length() - emcp_method_count;
4204
4205 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4206 _previous_versions != nullptr) {
4207 // We have a mix of obsolete and EMCP methods so we have to
4208 // clear out any matching EMCP method entries the hard way.
4209 int local_count = 0;
4210 for (int i = 0; i < old_methods->length(); i++) {
4211 Method* old_method = old_methods->at(i);
4212 if (old_method->is_obsolete()) {
4213 // only obsolete methods are interesting
4214 Symbol* m_name = old_method->name();
4215 Symbol* m_signature = old_method->signature();
4216
4217 // previous versions are linked together through the InstanceKlass
4218 int j = 0;
4219 for (InstanceKlass* prev_version = _previous_versions;
4220 prev_version != nullptr;
4221 prev_version = prev_version->previous_versions(), j++) {
4222
4223 Array<Method*>* method_refs = prev_version->methods();
4224 for (int k = 0; k < method_refs->length(); k++) {
4225 Method* method = method_refs->at(k);
4226
4227 if (!method->is_obsolete() &&
4228 method->name() == m_name &&
4229 method->signature() == m_signature) {
4230 // The current RedefineClasses() call has made all EMCP
4231 // versions of this method obsolete so mark it as obsolete
4232 log_trace(redefine, class, iklass, add)
4233 ("%s(%s): flush obsolete method @%d in version @%d",
4234 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4235
4236 method->set_is_obsolete();
4237 break;
4238 }
4239 }
4240
4241 // The previous loop may not find a matching EMCP method, but
4242 // that doesn't mean that we can optimize and not go any
4243 // further back in the PreviousVersion generations. The EMCP
4244 // method for this generation could have already been made obsolete,
4245 // but there still may be an older EMCP method that has not
4246 // been made obsolete.
4247 }
4248
4249 if (++local_count >= obsolete_method_count) {
4250 // no more obsolete methods so bail out now
4251 break;
4252 }
4253 }
4254 }
4255 }
4256 }
4257
4258 // Save the scratch_class as the previous version if any of the methods are running.
4259 // The previous_versions are used to set breakpoints in EMCP methods and they are
4260 // also used to clean MethodData links to redefined methods that are no longer running.
4261 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4262 int emcp_method_count) {
4263 assert(Thread::current()->is_VM_thread(),
4264 "only VMThread can add previous versions");
4265
4266 ResourceMark rm;
4267 log_trace(redefine, class, iklass, add)
4268 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4269
4270 // Clean out old previous versions for this class
4271 purge_previous_version_list();
4272
4273 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4274 // a previous redefinition may be made obsolete by this redefinition.
4275 Array<Method*>* old_methods = scratch_class->methods();
4276 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4277
4278 // If the constant pool for this previous version of the class
4279 // is not marked as being on the stack, then none of the methods
4280 // in this previous version of the class are on the stack so
4281 // we don't need to add this as a previous version.
4282 ConstantPool* cp_ref = scratch_class->constants();
4283 if (!cp_ref->on_stack()) {
4284 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4285 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4286 return;
4287 }
4288
4289 // Add previous version if any methods are still running or if this is
4290 // a shared class which should never be removed.
4291 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4292 scratch_class->link_previous_versions(previous_versions());
4293 link_previous_versions(scratch_class);
4294 if (cp_ref->is_shared()) {
4295 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4296 } else {
4297 // We only set clean_previous_versions flag for processing during class
4298 // unloading for non-shared classes.
4299 _should_clean_previous_versions = true;
4300 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4301 }
4302 } // end add_previous_version()
4303
4304 #endif // INCLUDE_JVMTI
4305
4306 Method* InstanceKlass::method_with_idnum(int idnum) {
4307 Method* m = nullptr;
4308 if (idnum < methods()->length()) {
4309 m = methods()->at(idnum);
4310 }
4311 if (m == nullptr || m->method_idnum() != idnum) {
4312 for (int index = 0; index < methods()->length(); ++index) {
4313 m = methods()->at(index);
4314 if (m->method_idnum() == idnum) {
4315 return m;
4316 }
4317 }
4318 // None found, return null for the caller to handle.
4319 return nullptr;
4320 }
4321 return m;
4322 }
4323
4324
4325 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4326 if (idnum >= methods()->length()) {
4327 return nullptr;
4328 }
4329 Method* m = methods()->at(idnum);
4330 if (m != nullptr && m->orig_method_idnum() == idnum) {
4331 return m;
4332 }
4333 // Obsolete method idnum does not match the original idnum
4334 for (int index = 0; index < methods()->length(); ++index) {
4335 m = methods()->at(index);
4336 if (m->orig_method_idnum() == idnum) {
4337 return m;
4338 }
4339 }
4340 // None found, return null for the caller to handle.
4341 return nullptr;
4342 }
4343
4344
4345 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4346 InstanceKlass* holder = get_klass_version(version);
4347 if (holder == nullptr) {
4348 return nullptr; // The version of klass is gone, no method is found
4349 }
4350 Method* method = holder->method_with_orig_idnum(idnum);
4351 return method;
4352 }
4353
4354 #if INCLUDE_JVMTI
4355 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4356 return _cached_class_file;
4357 }
4358
4359 jint InstanceKlass::get_cached_class_file_len() {
4360 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4361 }
4362
4363 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4364 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4365 }
4366 #endif
4367
4368 // Make a step iterating over the class hierarchy under the root class.
4369 // Skips subclasses if requested.
4370 void ClassHierarchyIterator::next() {
4371 assert(_current != nullptr, "required");
4372 if (_visit_subclasses && _current->subklass() != nullptr) {
4373 _current = _current->subklass();
4374 return; // visit next subclass
4375 }
4376 _visit_subclasses = true; // reset
4377 while (_current->next_sibling() == nullptr && _current != _root) {
4378 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4379 }
4380 if (_current == _root) {
4381 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4382 _current = nullptr;
4383 return;
4384 }
4385 _current = _current->next_sibling();
4386 return; // visit next sibling subclass
4387 }