1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotClassInitializer.hpp"
26 #include "cds/archiveUtils.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/cdsEnumKlass.hpp"
29 #include "cds/classListWriter.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classFileParser.hpp"
33 #include "classfile/classFileStream.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/classLoaderData.inline.hpp"
36 #include "classfile/javaClasses.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/verifier.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "code/codeCache.hpp"
44 #include "code/dependencyContext.hpp"
45 #include "compiler/compilationPolicy.hpp"
46 #include "compiler/compileBroker.hpp"
47 #include "gc/shared/collectedHeap.inline.hpp"
48 #include "interpreter/bytecodeStream.hpp"
49 #include "interpreter/oopMapCache.hpp"
50 #include "interpreter/rewriter.hpp"
51 #include "jvm.h"
52 #include "jvmtifiles/jvmti.h"
53 #include "logging/log.hpp"
54 #include "klass.inline.hpp"
55 #include "logging/logMessage.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/allocation.inline.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/metadataFactory.hpp"
60 #include "memory/metaspaceClosure.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/fieldStreams.inline.hpp"
65 #include "oops/constantPool.hpp"
66 #include "oops/instanceClassLoaderKlass.hpp"
67 #include "oops/instanceKlass.inline.hpp"
68 #include "oops/instanceMirrorKlass.hpp"
69 #include "oops/instanceOop.hpp"
70 #include "oops/instanceStackChunkKlass.hpp"
71 #include "oops/klass.inline.hpp"
72 #include "oops/method.hpp"
73 #include "oops/oop.inline.hpp"
74 #include "oops/recordComponent.hpp"
75 #include "oops/symbol.hpp"
76 #include "prims/jvmtiExport.hpp"
77 #include "prims/jvmtiRedefineClasses.hpp"
78 #include "prims/jvmtiThreadState.hpp"
79 #include "prims/methodComparator.hpp"
80 #include "runtime/arguments.hpp"
81 #include "runtime/deoptimization.hpp"
82 #include "runtime/atomic.hpp"
83 #include "runtime/fieldDescriptor.inline.hpp"
84 #include "runtime/handles.inline.hpp"
85 #include "runtime/javaCalls.hpp"
86 #include "runtime/javaThread.inline.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/orderAccess.hpp"
89 #include "runtime/os.inline.hpp"
90 #include "runtime/reflection.hpp"
91 #include "runtime/synchronizer.hpp"
92 #include "runtime/threads.hpp"
93 #include "services/classLoadingService.hpp"
94 #include "services/finalizerService.hpp"
95 #include "services/threadService.hpp"
96 #include "utilities/dtrace.hpp"
97 #include "utilities/events.hpp"
98 #include "utilities/macros.hpp"
99 #include "utilities/nativeStackPrinter.hpp"
100 #include "utilities/stringUtils.hpp"
101 #ifdef COMPILER1
102 #include "c1/c1_Compiler.hpp"
103 #endif
104 #if INCLUDE_JFR
105 #include "jfr/jfrEvents.hpp"
106 #endif
107
108 #ifdef DTRACE_ENABLED
109
110
111 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
112 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
113 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
114 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
115 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
116 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
117 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
118 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
119 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
120 { \
121 char* data = nullptr; \
122 int len = 0; \
123 Symbol* clss_name = name(); \
124 if (clss_name != nullptr) { \
125 data = (char*)clss_name->bytes(); \
126 len = clss_name->utf8_length(); \
127 } \
128 HOTSPOT_CLASS_INITIALIZATION_##type( \
129 data, len, (void*)class_loader(), thread_type); \
130 }
131
132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
133 { \
134 char* data = nullptr; \
135 int len = 0; \
136 Symbol* clss_name = name(); \
137 if (clss_name != nullptr) { \
138 data = (char*)clss_name->bytes(); \
139 len = clss_name->utf8_length(); \
140 } \
141 HOTSPOT_CLASS_INITIALIZATION_##type( \
142 data, len, (void*)class_loader(), thread_type, wait); \
143 }
144
145 #else // ndef DTRACE_ENABLED
146
147 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
148 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
149
150 #endif // ndef DTRACE_ENABLED
151
152 bool InstanceKlass::_finalization_enabled = true;
153
154 static inline bool is_class_loader(const Symbol* class_name,
155 const ClassFileParser& parser) {
156 assert(class_name != nullptr, "invariant");
157
158 if (class_name == vmSymbols::java_lang_ClassLoader()) {
159 return true;
160 }
161
162 if (vmClasses::ClassLoader_klass_loaded()) {
163 const Klass* const super_klass = parser.super_klass();
164 if (super_klass != nullptr) {
165 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
166 return true;
167 }
168 }
169 }
170 return false;
171 }
172
173 static inline bool is_stack_chunk_class(const Symbol* class_name,
174 const ClassLoaderData* loader_data) {
175 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
176 loader_data->is_the_null_class_loader_data());
177 }
178
179 // private: called to verify that k is a static member of this nest.
180 // We know that k is an instance class in the same package and hence the
181 // same classloader.
182 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
183 assert(!is_hidden(), "unexpected hidden class");
184 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
185 if (log_is_enabled(Trace, class, nestmates)) {
186 ResourceMark rm(current);
187 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
188 k->external_name(), this->external_name());
189 }
190 return false;
191 }
192
193 if (log_is_enabled(Trace, class, nestmates)) {
194 ResourceMark rm(current);
195 log_trace(class, nestmates)("Checking nest membership of %s in %s",
196 k->external_name(), this->external_name());
197 }
198
199 // Check for the named class in _nest_members.
200 // We don't resolve, or load, any classes.
201 for (int i = 0; i < _nest_members->length(); i++) {
202 int cp_index = _nest_members->at(i);
203 Symbol* name = _constants->klass_name_at(cp_index);
204 if (name == k->name()) {
205 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
206 return true;
207 }
208 }
209 log_trace(class, nestmates)("- class is NOT a nest member!");
210 return false;
211 }
212
213 // Called to verify that k is a permitted subclass of this class.
214 // The incoming stringStream is used to format the messages for error logging and for the caller
215 // to use for exception throwing.
216 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
217 Thread* current = Thread::current();
218 assert(k != nullptr, "sanity check");
219 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
220 "unexpected empty _permitted_subclasses array");
221
222 if (log_is_enabled(Trace, class, sealed)) {
223 ResourceMark rm(current);
224 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
225 k->external_name(), this->external_name());
226 }
227
228 // Check that the class and its super are in the same module.
229 if (k->module() != this->module()) {
230 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
231 "and sealed class %s is in module '%s' with loader %s",
232 k->external_name(),
233 k->module()->name_as_C_string(),
234 k->module()->loader_data()->loader_name_and_id(),
235 this->external_name(),
236 this->module()->name_as_C_string(),
237 this->module()->loader_data()->loader_name_and_id());
238 log_trace(class, sealed)(" - %s", ss.as_string());
239 return false;
240 }
241
242 if (!k->is_public() && !is_same_class_package(k)) {
243 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
244 "and sealed class %s is in package '%s' with classloader %s",
245 k->external_name(),
246 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
247 k->module()->loader_data()->loader_name_and_id(),
248 this->external_name(),
249 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
250 this->module()->loader_data()->loader_name_and_id());
251 log_trace(class, sealed)(" - %s", ss.as_string());
252 return false;
253 }
254
255 for (int i = 0; i < _permitted_subclasses->length(); i++) {
256 int cp_index = _permitted_subclasses->at(i);
257 Symbol* name = _constants->klass_name_at(cp_index);
258 if (name == k->name()) {
259 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
260 return true;
261 }
262 }
263
264 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
265 k->external_name(), this->external_name());
266 log_trace(class, sealed)(" - %s", ss.as_string());
267 return false;
268 }
269
270 // Return nest-host class, resolving, validating and saving it if needed.
271 // In cases where this is called from a thread that cannot do classloading
272 // (such as a native JIT thread) then we simply return null, which in turn
273 // causes the access check to return false. Such code will retry the access
274 // from a more suitable environment later. Otherwise the _nest_host is always
275 // set once this method returns.
276 // Any errors from nest-host resolution must be preserved so they can be queried
277 // from higher-level access checking code, and reported as part of access checking
278 // exceptions.
279 // VirtualMachineErrors are propagated with a null return.
280 // Under any conditions where the _nest_host can be set to non-null the resulting
281 // value of it and, if applicable, the nest host resolution/validation error,
282 // are idempotent.
283 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
284 InstanceKlass* nest_host_k = _nest_host;
285 if (nest_host_k != nullptr) {
286 return nest_host_k;
287 }
288
289 ResourceMark rm(THREAD);
290
291 // need to resolve and save our nest-host class.
292 if (_nest_host_index != 0) { // we have a real nest_host
293 // Before trying to resolve check if we're in a suitable context
294 bool can_resolve = THREAD->can_call_java();
295 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
296 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
297 this->external_name());
298 return nullptr; // sentinel to say "try again from a different context"
299 }
300
301 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
302 this->external_name(),
303 _constants->klass_name_at(_nest_host_index)->as_C_string());
304
305 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
306 if (HAS_PENDING_EXCEPTION) {
307 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
308 return nullptr; // propagate VMEs
309 }
310 stringStream ss;
311 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
312 ss.print("Nest host resolution of %s with host %s failed: ",
313 this->external_name(), target_host_class);
314 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
315 const char* msg = ss.as_string(true /* on C-heap */);
316 constantPoolHandle cph(THREAD, constants());
317 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
318 CLEAR_PENDING_EXCEPTION;
319
320 log_trace(class, nestmates)("%s", msg);
321 } else {
322 // A valid nest-host is an instance class in the current package that lists this
323 // class as a nest member. If any of these conditions are not met the class is
324 // its own nest-host.
325 const char* error = nullptr;
326
327 // JVMS 5.4.4 indicates package check comes first
328 if (is_same_class_package(k)) {
329 // Now check actual membership. We can't be a member if our "host" is
330 // not an instance class.
331 if (k->is_instance_klass()) {
332 nest_host_k = InstanceKlass::cast(k);
333 bool is_member = nest_host_k->has_nest_member(THREAD, this);
334 if (is_member) {
335 _nest_host = nest_host_k; // save resolved nest-host value
336
337 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
338 this->external_name(), k->external_name());
339 return nest_host_k;
340 } else {
341 error = "current type is not listed as a nest member";
342 }
343 } else {
344 error = "host is not an instance class";
345 }
346 } else {
347 error = "types are in different packages";
348 }
349
350 // something went wrong, so record what and log it
351 {
352 stringStream ss;
353 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
354 this->external_name(),
355 this->class_loader_data()->loader_name_and_id(),
356 k->external_name(),
357 k->class_loader_data()->loader_name_and_id(),
358 error);
359 const char* msg = ss.as_string(true /* on C-heap */);
360 constantPoolHandle cph(THREAD, constants());
361 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
362 log_trace(class, nestmates)("%s", msg);
363 }
364 }
365 } else {
366 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
367 this->external_name());
368 }
369
370 // Either not in an explicit nest, or else an error occurred, so
371 // the nest-host is set to `this`. Any thread that sees this assignment
372 // will also see any setting of nest_host_error(), if applicable.
373 return (_nest_host = this);
374 }
375
376 // Dynamic nest member support: set this class's nest host to the given class.
377 // This occurs as part of the class definition, as soon as the instanceKlass
378 // has been created and doesn't require further resolution. The code:
379 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
380 // results in:
381 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
382 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
383 // We also know the "host" is a valid nest-host in the same package so we can
384 // assert some of those facts.
385 void InstanceKlass::set_nest_host(InstanceKlass* host) {
386 assert(is_hidden(), "must be a hidden class");
387 assert(host != nullptr, "null nest host specified");
388 assert(_nest_host == nullptr, "current class has resolved nest-host");
389 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
390 nest_host_error());
391 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
392 (host->_nest_host == host), "proposed host is not a valid nest-host");
393 // Can't assert this as package is not set yet:
394 // assert(is_same_class_package(host), "proposed host is in wrong package");
395
396 if (log_is_enabled(Trace, class, nestmates)) {
397 ResourceMark rm;
398 const char* msg = "";
399 // a hidden class does not expect a statically defined nest-host
400 if (_nest_host_index > 0) {
401 msg = "(the NestHost attribute in the current class is ignored)";
402 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
403 msg = "(the NestMembers attribute in the current class is ignored)";
404 }
405 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
406 this->external_name(),
407 host->external_name(),
408 msg);
409 }
410 // set dynamic nest host
411 _nest_host = host;
412 // Record dependency to keep nest host from being unloaded before this class.
413 ClassLoaderData* this_key = class_loader_data();
414 assert(this_key != nullptr, "sanity");
415 this_key->record_dependency(host);
416 }
417
418 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
419 // or we are k's nest_host - all of which is covered by comparing the two
420 // resolved_nest_hosts.
421 // Any exceptions (i.e. VMEs) are propagated.
422 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
423
424 assert(this != k, "this should be handled by higher-level code");
425
426 // Per JVMS 5.4.4 we first resolve and validate the current class, then
427 // the target class k.
428
429 InstanceKlass* cur_host = nest_host(CHECK_false);
430 if (cur_host == nullptr) {
431 return false;
432 }
433
434 Klass* k_nest_host = k->nest_host(CHECK_false);
435 if (k_nest_host == nullptr) {
436 return false;
437 }
438
439 bool access = (cur_host == k_nest_host);
440
441 ResourceMark rm(THREAD);
442 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
443 this->external_name(),
444 access ? "" : "NOT ",
445 k->external_name());
446 return access;
447 }
448
449 const char* InstanceKlass::nest_host_error() {
450 if (_nest_host_index == 0) {
451 return nullptr;
452 } else {
453 constantPoolHandle cph(Thread::current(), constants());
454 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
455 }
456 }
457
458 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
459 bool use_class_space, TRAPS) throw() {
460 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
461 }
462
463 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
464 const int size = InstanceKlass::size(parser.vtable_size(),
465 parser.itable_size(),
466 nonstatic_oop_map_size(parser.total_oop_map_count()),
467 parser.is_interface());
468
469 const Symbol* const class_name = parser.class_name();
470 assert(class_name != nullptr, "invariant");
471 ClassLoaderData* loader_data = parser.loader_data();
472 assert(loader_data != nullptr, "invariant");
473
474 InstanceKlass* ik;
475 const bool use_class_space = parser.klass_needs_narrow_id();
476
477 // Allocation
478 if (parser.is_instance_ref_klass()) {
479 // java.lang.ref.Reference
480 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
481 } else if (class_name == vmSymbols::java_lang_Class()) {
482 // mirror - java.lang.Class
483 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
484 } else if (is_stack_chunk_class(class_name, loader_data)) {
485 // stack chunk
486 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
487 } else if (is_class_loader(class_name, parser)) {
488 // class loader - java.lang.ClassLoader
489 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
490 } else {
491 // normal
492 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
493 }
494
495 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
496 assert(CompressedKlassPointers::is_encodable(ik),
497 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
498 }
499
500 // Check for pending exception before adding to the loader data and incrementing
501 // class count. Can get OOM here.
502 if (HAS_PENDING_EXCEPTION) {
503 return nullptr;
504 }
505
506 return ik;
507 }
508
509
510 // copy method ordering from resource area to Metaspace
511 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
512 if (m != nullptr) {
513 // allocate a new array and copy contents (memcpy?)
514 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
515 for (int i = 0; i < m->length(); i++) {
516 _method_ordering->at_put(i, m->at(i));
517 }
518 } else {
519 _method_ordering = Universe::the_empty_int_array();
520 }
521 }
522
523 // create a new array of vtable_indices for default methods
524 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
525 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
526 assert(default_vtable_indices() == nullptr, "only create once");
527 set_default_vtable_indices(vtable_indices);
528 return vtable_indices;
529 }
530
531
532 InstanceKlass::InstanceKlass() {
533 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
534 }
535
536 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
537 Klass(kind),
538 _nest_members(nullptr),
539 _nest_host(nullptr),
540 _permitted_subclasses(nullptr),
541 _record_components(nullptr),
542 _static_field_size(parser.static_field_size()),
543 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
544 _itable_len(parser.itable_size()),
545 _nest_host_index(0),
546 _init_state(allocated),
547 _reference_type(reference_type),
548 _init_thread(nullptr)
549 {
550 set_vtable_length(parser.vtable_size());
551 set_access_flags(parser.access_flags());
552 if (parser.is_hidden()) set_is_hidden();
553 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
554 false));
555
556 assert(nullptr == _methods, "underlying memory not zeroed?");
557 assert(is_instance_klass(), "is layout incorrect?");
558 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
559 }
560
561 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
562 Array<Method*>* methods) {
563 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
564 !methods->is_shared()) {
565 for (int i = 0; i < methods->length(); i++) {
566 Method* method = methods->at(i);
567 if (method == nullptr) continue; // maybe null if error processing
568 // Only want to delete methods that are not executing for RedefineClasses.
569 // The previous version will point to them so they're not totally dangling
570 assert (!method->on_stack(), "shouldn't be called with methods on stack");
571 MetadataFactory::free_metadata(loader_data, method);
572 }
573 MetadataFactory::free_array<Method*>(loader_data, methods);
574 }
575 }
576
577 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
578 const Klass* super_klass,
579 Array<InstanceKlass*>* local_interfaces,
580 Array<InstanceKlass*>* transitive_interfaces) {
581 // Only deallocate transitive interfaces if not empty, same as super class
582 // or same as local interfaces. See code in parseClassFile.
583 Array<InstanceKlass*>* ti = transitive_interfaces;
584 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
585 // check that the interfaces don't come from super class
586 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
587 InstanceKlass::cast(super_klass)->transitive_interfaces();
588 if (ti != sti && ti != nullptr && !ti->is_shared()) {
589 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
590 }
591 }
592
593 // local interfaces can be empty
594 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
595 local_interfaces != nullptr && !local_interfaces->is_shared()) {
596 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
597 }
598 }
599
600 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
601 Array<RecordComponent*>* record_components) {
602 if (record_components != nullptr && !record_components->is_shared()) {
603 for (int i = 0; i < record_components->length(); i++) {
604 RecordComponent* record_component = record_components->at(i);
605 MetadataFactory::free_metadata(loader_data, record_component);
606 }
607 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
608 }
609 }
610
611 // This function deallocates the metadata and C heap pointers that the
612 // InstanceKlass points to.
613 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
614 // Orphan the mirror first, CMS thinks it's still live.
615 if (java_mirror() != nullptr) {
616 java_lang_Class::set_klass(java_mirror(), nullptr);
617 }
618
619 // Also remove mirror from handles
620 loader_data->remove_handle(_java_mirror);
621
622 // Need to take this class off the class loader data list.
623 loader_data->remove_class(this);
624
625 // The array_klass for this class is created later, after error handling.
626 // For class redefinition, we keep the original class so this scratch class
627 // doesn't have an array class. Either way, assert that there is nothing
628 // to deallocate.
629 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
630
631 // Release C heap allocated data that this points to, which includes
632 // reference counting symbol names.
633 // Can't release the constant pool or MethodData C heap data here because the constant
634 // pool can be deallocated separately from the InstanceKlass for default methods and
635 // redefine classes. MethodData can also be released separately.
636 release_C_heap_structures(/* release_sub_metadata */ false);
637
638 deallocate_methods(loader_data, methods());
639 set_methods(nullptr);
640
641 deallocate_record_components(loader_data, record_components());
642 set_record_components(nullptr);
643
644 if (method_ordering() != nullptr &&
645 method_ordering() != Universe::the_empty_int_array() &&
646 !method_ordering()->is_shared()) {
647 MetadataFactory::free_array<int>(loader_data, method_ordering());
648 }
649 set_method_ordering(nullptr);
650
651 // default methods can be empty
652 if (default_methods() != nullptr &&
653 default_methods() != Universe::the_empty_method_array() &&
654 !default_methods()->is_shared()) {
655 MetadataFactory::free_array<Method*>(loader_data, default_methods());
656 }
657 // Do NOT deallocate the default methods, they are owned by superinterfaces.
658 set_default_methods(nullptr);
659
660 // default methods vtable indices can be empty
661 if (default_vtable_indices() != nullptr &&
662 !default_vtable_indices()->is_shared()) {
663 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
664 }
665 set_default_vtable_indices(nullptr);
666
667
668 // This array is in Klass, but remove it with the InstanceKlass since
669 // this place would be the only caller and it can share memory with transitive
670 // interfaces.
671 if (secondary_supers() != nullptr &&
672 secondary_supers() != Universe::the_empty_klass_array() &&
673 // see comments in compute_secondary_supers about the following cast
674 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
675 !secondary_supers()->is_shared()) {
676 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
677 }
678 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
679
680 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
681 set_transitive_interfaces(nullptr);
682 set_local_interfaces(nullptr);
683
684 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
685 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
686 }
687 set_fieldinfo_stream(nullptr);
688
689 if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->is_shared()) {
690 MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
691 }
692 set_fieldinfo_search_table(nullptr);
693
694 if (fields_status() != nullptr && !fields_status()->is_shared()) {
695 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
696 }
697 set_fields_status(nullptr);
698
699 // If a method from a redefined class is using this constant pool, don't
700 // delete it, yet. The new class's previous version will point to this.
701 if (constants() != nullptr) {
702 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
703 if (!constants()->is_shared()) {
704 MetadataFactory::free_metadata(loader_data, constants());
705 }
706 // Delete any cached resolution errors for the constant pool
707 SystemDictionary::delete_resolution_error(constants());
708
709 set_constants(nullptr);
710 }
711
712 if (inner_classes() != nullptr &&
713 inner_classes() != Universe::the_empty_short_array() &&
714 !inner_classes()->is_shared()) {
715 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
716 }
717 set_inner_classes(nullptr);
718
719 if (nest_members() != nullptr &&
720 nest_members() != Universe::the_empty_short_array() &&
721 !nest_members()->is_shared()) {
722 MetadataFactory::free_array<jushort>(loader_data, nest_members());
723 }
724 set_nest_members(nullptr);
725
726 if (permitted_subclasses() != nullptr &&
727 permitted_subclasses() != Universe::the_empty_short_array() &&
728 !permitted_subclasses()->is_shared()) {
729 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
730 }
731 set_permitted_subclasses(nullptr);
732
733 // We should deallocate the Annotations instance if it's not in shared spaces.
734 if (annotations() != nullptr && !annotations()->is_shared()) {
735 MetadataFactory::free_metadata(loader_data, annotations());
736 }
737 set_annotations(nullptr);
738
739 SystemDictionaryShared::handle_class_unloading(this);
740
741 #if INCLUDE_CDS_JAVA_HEAP
742 if (CDSConfig::is_dumping_heap()) {
743 HeapShared::remove_scratch_objects(this);
744 }
745 #endif
746 }
747
748 bool InstanceKlass::is_record() const {
749 return _record_components != nullptr &&
750 is_final() &&
751 java_super() == vmClasses::Record_klass();
752 }
753
754 bool InstanceKlass::is_sealed() const {
755 return _permitted_subclasses != nullptr &&
756 _permitted_subclasses != Universe::the_empty_short_array();
757 }
758
759 // JLS 8.9: An enum class is either implicitly final and derives
760 // from java.lang.Enum, or else is implicitly sealed to its
761 // anonymous subclasses. This query detects both kinds.
762 // It does not validate the finality or
763 // sealing conditions: it merely checks for a super of Enum.
764 // This is sufficient for recognizing well-formed enums.
765 bool InstanceKlass::is_enum_subclass() const {
766 InstanceKlass* s = java_super();
767 return (s == vmClasses::Enum_klass() ||
768 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
769 }
770
771 bool InstanceKlass::should_be_initialized() const {
772 return !is_initialized();
773 }
774
775 klassItable InstanceKlass::itable() const {
776 return klassItable(const_cast<InstanceKlass*>(this));
777 }
778
779 // JVMTI spec thinks there are signers and protection domain in the
780 // instanceKlass. These accessors pretend these fields are there.
781 // The hprof specification also thinks these fields are in InstanceKlass.
782 oop InstanceKlass::protection_domain() const {
783 // return the protection_domain from the mirror
784 return java_lang_Class::protection_domain(java_mirror());
785 }
786
787 objArrayOop InstanceKlass::signers() const {
788 // return the signers from the mirror
789 return java_lang_Class::signers(java_mirror());
790 }
791
792 oop InstanceKlass::init_lock() const {
793 // return the init lock from the mirror
794 oop lock = java_lang_Class::init_lock(java_mirror());
795 // Prevent reordering with any access of initialization state
796 OrderAccess::loadload();
797 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
798 "only fully initialized state can have a null lock");
799 return lock;
800 }
801
802 void InstanceKlass::initialize_preemptable(TRAPS) {
803 if (this->should_be_initialized()) {
804 PREEMPT_ON_INIT_SUPPORTED_ONLY(PreemptableInitCall pic(THREAD, this);)
805 initialize_impl(THREAD);
806 } else {
807 assert(is_initialized(), "sanity check");
808 }
809 }
810
811 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
812 // process. The step comments refers to the procedure described in that section.
813 // Note: implementation moved to static method to expose the this pointer.
814 void InstanceKlass::initialize(TRAPS) {
815 if (this->should_be_initialized()) {
816 initialize_impl(CHECK);
817 // Note: at this point the class may be initialized
818 // OR it may be in the state of being initialized
819 // in case of recursive initialization!
820 } else {
821 assert(is_initialized(), "sanity check");
822 }
823 }
824
825 #ifdef ASSERT
826 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
827 assert(has_aot_initialized_mirror(), "must be");
828
829 InstanceKlass* s = java_super();
830 if (s != nullptr) {
831 DEBUG_ONLY(ResourceMark rm);
832 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
833 s->external_name(), external_name());
834 s->assert_no_clinit_will_run_for_aot_initialized_class();
835 }
836
837 Array<InstanceKlass*>* interfaces = local_interfaces();
838 int len = interfaces->length();
839 for (int i = 0; i < len; i++) {
840 InstanceKlass* intf = interfaces->at(i);
841 if (!intf->is_initialized()) {
842 ResourceMark rm;
843 // Note: an interface needs to be marked as is_initialized() only if
844 // - it has a <clinit>
845 // - it has declared a default method.
846 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
847 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
848 intf->external_name(), external_name());
849 }
850 }
851 }
852 #endif
853
854 #if INCLUDE_CDS
855 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
856 assert(has_aot_initialized_mirror(), "must be");
857 assert(CDSConfig::is_loading_heap(), "must be");
858 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
859 assert_no_clinit_will_run_for_aot_initialized_class();
860
861 if (is_initialized()) {
862 return;
863 }
864
865 if (is_runtime_setup_required()) {
866 // Need to take the slow path, which will call the runtimeSetup() function instead
867 // of <clinit>
868 initialize(CHECK);
869 return;
870 }
871 if (log_is_enabled(Info, aot, init)) {
872 ResourceMark rm;
873 log_info(aot, init)("%s (aot-inited)", external_name());
874 }
875
876 link_class(CHECK);
877
878 #ifdef ASSERT
879 {
880 Handle h_init_lock(THREAD, init_lock());
881 ObjectLocker ol(h_init_lock, THREAD);
882 assert(!is_initialized(), "sanity");
883 assert(!is_being_initialized(), "sanity");
884 assert(!is_in_error_state(), "sanity");
885 }
886 #endif
887
888 set_init_thread(THREAD);
889 set_initialization_state_and_notify(fully_initialized, CHECK);
890 }
891 #endif
892
893 bool InstanceKlass::verify_code(TRAPS) {
894 // 1) Verify the bytecodes
895 return Verifier::verify(this, should_verify_class(), THREAD);
896 }
897
898 void InstanceKlass::link_class(TRAPS) {
899 assert(is_loaded(), "must be loaded");
900 if (!is_linked()) {
901 link_class_impl(CHECK);
902 }
903 }
904
905 // Called to verify that a class can link during initialization, without
906 // throwing a VerifyError.
907 bool InstanceKlass::link_class_or_fail(TRAPS) {
908 assert(is_loaded(), "must be loaded");
909 if (!is_linked()) {
910 link_class_impl(CHECK_false);
911 }
912 return is_linked();
913 }
914
915 bool InstanceKlass::link_class_impl(TRAPS) {
916 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
917 // This is for CDS static dump only -- we use the in_error_state to indicate that
918 // the class has failed verification. Throwing the NoClassDefFoundError here is just
919 // a convenient way to stop repeat attempts to verify the same (bad) class.
920 //
921 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
922 // if we are executing Java code. This is not a problem for CDS dumping phase since
923 // it doesn't execute any Java code.
924 ResourceMark rm(THREAD);
925 // Names are all known to be < 64k so we know this formatted message is not excessively large.
926 Exceptions::fthrow(THREAD_AND_LOCATION,
927 vmSymbols::java_lang_NoClassDefFoundError(),
928 "Class %s, or one of its supertypes, failed class initialization",
929 external_name());
930 return false;
931 }
932 // return if already verified
933 if (is_linked()) {
934 return true;
935 }
936
937 // Timing
938 // timer handles recursion
939 JavaThread* jt = THREAD;
940
941 // link super class before linking this class
942 Klass* super_klass = super();
943 if (super_klass != nullptr) {
944 if (super_klass->is_interface()) { // check if super class is an interface
945 ResourceMark rm(THREAD);
946 // Names are all known to be < 64k so we know this formatted message is not excessively large.
947 Exceptions::fthrow(
948 THREAD_AND_LOCATION,
949 vmSymbols::java_lang_IncompatibleClassChangeError(),
950 "class %s has interface %s as super class",
951 external_name(),
952 super_klass->external_name()
953 );
954 return false;
955 }
956
957 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
958 ik_super->link_class_impl(CHECK_false);
959 }
960
961 // link all interfaces implemented by this class before linking this class
962 Array<InstanceKlass*>* interfaces = local_interfaces();
963 int num_interfaces = interfaces->length();
964 for (int index = 0; index < num_interfaces; index++) {
965 InstanceKlass* interk = interfaces->at(index);
966 interk->link_class_impl(CHECK_false);
967 }
968
969 // in case the class is linked in the process of linking its superclasses
970 if (is_linked()) {
971 return true;
972 }
973
974 // trace only the link time for this klass that includes
975 // the verification time
976 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
977 ClassLoader::perf_class_link_selftime(),
978 ClassLoader::perf_classes_linked(),
979 jt->get_thread_stat()->perf_recursion_counts_addr(),
980 jt->get_thread_stat()->perf_timers_addr(),
981 PerfClassTraceTime::CLASS_LINK);
982
983 // verification & rewriting
984 {
985 HandleMark hm(THREAD);
986 Handle h_init_lock(THREAD, init_lock());
987 ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE_false);
988 // Don't preempt once we own the monitor as that would complicate
989 // redoing the VM call (we don't expect to own this monitor).
990 NoPreemptMark npm(THREAD);
991
992 // rewritten will have been set if loader constraint error found
993 // on an earlier link attempt
994 // don't verify or rewrite if already rewritten
995 //
996
997 if (!is_linked()) {
998 if (!is_rewritten()) {
999 if (is_shared()) {
1000 assert(!verified_at_dump_time(), "must be");
1001 }
1002 {
1003 bool verify_ok = verify_code(THREAD);
1004 if (!verify_ok) {
1005 return false;
1006 }
1007 }
1008
1009 // Just in case a side-effect of verify linked this class already
1010 // (which can sometimes happen since the verifier loads classes
1011 // using custom class loaders, which are free to initialize things)
1012 if (is_linked()) {
1013 return true;
1014 }
1015
1016 // also sets rewritten
1017 rewrite_class(CHECK_false);
1018 } else if (is_shared()) {
1019 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1020 }
1021
1022 // relocate jsrs and link methods after they are all rewritten
1023 link_methods(CHECK_false);
1024
1025 // Initialize the vtable and interface table after
1026 // methods have been rewritten since rewrite may
1027 // fabricate new Method*s.
1028 // also does loader constraint checking
1029 //
1030 // initialize_vtable and initialize_itable need to be rerun
1031 // for a shared class if
1032 // 1) the class is loaded by custom class loader or
1033 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1034 // 3) the class was not verified during dump time
1035 bool need_init_table = true;
1036 if (is_shared() && verified_at_dump_time() &&
1037 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1038 need_init_table = false;
1039 }
1040 if (need_init_table) {
1041 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1042 itable().initialize_itable_and_check_constraints(CHECK_false);
1043 }
1044 #ifdef ASSERT
1045 vtable().verify(tty, true);
1046 // In case itable verification is ever added.
1047 // itable().verify(tty, true);
1048 #endif
1049 if (Universe::is_fully_initialized()) {
1050 DeoptimizationScope deopt_scope;
1051 {
1052 // Now mark all code that assumes the class is not linked.
1053 // Set state under the Compile_lock also.
1054 MutexLocker ml(THREAD, Compile_lock);
1055
1056 set_init_state(linked);
1057 CodeCache::mark_dependents_on(&deopt_scope, this);
1058 }
1059 // Perform the deopt handshake outside Compile_lock.
1060 deopt_scope.deoptimize_marked();
1061 } else {
1062 set_init_state(linked);
1063 }
1064 if (JvmtiExport::should_post_class_prepare()) {
1065 JvmtiExport::post_class_prepare(THREAD, this);
1066 }
1067 }
1068 }
1069 return true;
1070 }
1071
1072 // Rewrite the byte codes of all of the methods of a class.
1073 // The rewriter must be called exactly once. Rewriting must happen after
1074 // verification but before the first method of the class is executed.
1075 void InstanceKlass::rewrite_class(TRAPS) {
1076 assert(is_loaded(), "must be loaded");
1077 if (is_rewritten()) {
1078 assert(is_shared(), "rewriting an unshared class?");
1079 return;
1080 }
1081 Rewriter::rewrite(this, CHECK);
1082 set_rewritten();
1083 }
1084
1085 // Now relocate and link method entry points after class is rewritten.
1086 // This is outside is_rewritten flag. In case of an exception, it can be
1087 // executed more than once.
1088 void InstanceKlass::link_methods(TRAPS) {
1089 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1090
1091 int len = methods()->length();
1092 for (int i = len-1; i >= 0; i--) {
1093 methodHandle m(THREAD, methods()->at(i));
1094
1095 // Set up method entry points for compiler and interpreter .
1096 m->link_method(m, CHECK);
1097 }
1098 }
1099
1100 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1101 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1102 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1103 for (int i = 0; i < local_interfaces()->length(); ++i) {
1104 InstanceKlass* ik = local_interfaces()->at(i);
1105
1106 // Initialization is depth first search ie. we start with top of the inheritance tree
1107 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1108 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1109 if (ik->has_nonstatic_concrete_methods()) {
1110 ik->initialize_super_interfaces(CHECK);
1111 }
1112
1113 // Only initialize() interfaces that "declare" concrete methods.
1114 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1115 ik->initialize(CHECK);
1116 }
1117 }
1118 }
1119
1120 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1121 static InitializationErrorTable* _initialization_error_table;
1122
1123 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1124 // Create the same exception with a message indicating the thread name,
1125 // and the StackTraceElements.
1126 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1127 ResourceMark rm(current);
1128 if (init_error.is_null()) {
1129 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1130
1131 // We failed to create the new exception, most likely due to either out-of-memory or
1132 // a stackoverflow error. If the original exception was either of those then we save
1133 // the shared, pre-allocated, stackless, instance of that exception.
1134 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1135 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1136 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1137 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1138 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1139 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1140 } else {
1141 return;
1142 }
1143 }
1144
1145 MutexLocker ml(current, ClassInitError_lock);
1146 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1147 bool created;
1148 if (_initialization_error_table == nullptr) {
1149 _initialization_error_table = new (mtClass) InitializationErrorTable();
1150 }
1151 _initialization_error_table->put_if_absent(this, elem, &created);
1152 assert(created, "Initialization is single threaded");
1153 log_trace(class, init)("Initialization error added for class %s", external_name());
1154 }
1155
1156 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1157 MutexLocker ml(current, ClassInitError_lock);
1158 if (_initialization_error_table == nullptr) {
1159 return nullptr;
1160 }
1161 OopHandle* h = _initialization_error_table->get(this);
1162 return (h != nullptr) ? h->resolve() : nullptr;
1163 }
1164
1165 // Need to remove entries for unloaded classes.
1166 void InstanceKlass::clean_initialization_error_table() {
1167 struct InitErrorTableCleaner {
1168 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1169 if (!ik->is_loader_alive()) {
1170 h.release(Universe::vm_global());
1171 return true;
1172 } else {
1173 return false;
1174 }
1175 }
1176 };
1177
1178 assert_locked_or_safepoint(ClassInitError_lock);
1179 InitErrorTableCleaner cleaner;
1180 if (_initialization_error_table != nullptr) {
1181 _initialization_error_table->unlink(&cleaner);
1182 }
1183 }
1184
1185 void InstanceKlass::initialize_impl(TRAPS) {
1186 HandleMark hm(THREAD);
1187
1188 // Make sure klass is linked (verified) before initialization
1189 // A class could already be verified, since it has been reflected upon.
1190 link_class(CHECK);
1191
1192 DTRACE_CLASSINIT_PROBE(required, -1);
1193
1194 bool wait = false;
1195
1196 JavaThread* jt = THREAD;
1197
1198 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1199
1200 // refer to the JVM book page 47 for description of steps
1201 // Step 1
1202 {
1203 Handle h_init_lock(THREAD, init_lock());
1204 ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE);
1205
1206 // Step 2
1207 // If we were to use wait() instead of waitInterruptibly() then
1208 // we might end up throwing IE from link/symbol resolution sites
1209 // that aren't expected to throw. This would wreak havoc. See 6320309.
1210 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1211 if (debug_logging_enabled) {
1212 ResourceMark rm(jt);
1213 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1214 jt->name(), external_name(), init_thread_name());
1215 }
1216 wait = true;
1217 jt->set_class_to_be_initialized(this);
1218 ol.wait_uninterruptibly(CHECK_PREEMPTABLE);
1219 jt->set_class_to_be_initialized(nullptr);
1220 }
1221
1222 // Step 3
1223 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1224 if (debug_logging_enabled) {
1225 ResourceMark rm(jt);
1226 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1227 jt->name(), external_name());
1228 }
1229 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1230 return;
1231 }
1232
1233 // Step 4
1234 if (is_initialized()) {
1235 if (debug_logging_enabled) {
1236 ResourceMark rm(jt);
1237 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1238 jt->name(), external_name());
1239 }
1240 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1241 return;
1242 }
1243
1244 // Step 5
1245 if (is_in_error_state()) {
1246 if (debug_logging_enabled) {
1247 ResourceMark rm(jt);
1248 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1249 jt->name(), external_name());
1250 }
1251
1252 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1253 ResourceMark rm(THREAD);
1254 Handle cause(THREAD, get_initialization_error(THREAD));
1255
1256 stringStream ss;
1257 ss.print("Could not initialize class %s", external_name());
1258 if (cause.is_null()) {
1259 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1260 } else {
1261 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1262 ss.as_string(), cause);
1263 }
1264 } else {
1265
1266 // Step 6
1267 set_init_state(being_initialized);
1268 set_init_thread(jt);
1269 if (debug_logging_enabled) {
1270 ResourceMark rm(jt);
1271 log_debug(class, init)("Thread \"%s\" is initializing %s",
1272 jt->name(), external_name());
1273 }
1274 }
1275 }
1276
1277 // Block preemption once we are the initializer thread.
1278 // Unmounting now would complicate the reentrant case.
1279 NoPreemptMark npm(THREAD);
1280
1281 // Step 7
1282 // Next, if C is a class rather than an interface, initialize it's super class and super
1283 // interfaces.
1284 if (!is_interface()) {
1285 Klass* super_klass = super();
1286 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1287 super_klass->initialize(THREAD);
1288 }
1289 // If C implements any interface that declares a non-static, concrete method,
1290 // the initialization of C triggers initialization of its super interfaces.
1291 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1292 // having a superinterface that declares, non-static, concrete methods
1293 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1294 initialize_super_interfaces(THREAD);
1295 }
1296
1297 // If any exceptions, complete abruptly, throwing the same exception as above.
1298 if (HAS_PENDING_EXCEPTION) {
1299 Handle e(THREAD, PENDING_EXCEPTION);
1300 CLEAR_PENDING_EXCEPTION;
1301 {
1302 EXCEPTION_MARK;
1303 add_initialization_error(THREAD, e);
1304 // Locks object, set state, and notify all waiting threads
1305 set_initialization_state_and_notify(initialization_error, THREAD);
1306 CLEAR_PENDING_EXCEPTION;
1307 }
1308 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1309 THROW_OOP(e());
1310 }
1311 }
1312
1313
1314 // Step 8
1315 {
1316 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1317 if (class_initializer() != nullptr) {
1318 // Timer includes any side effects of class initialization (resolution,
1319 // etc), but not recursive entry into call_class_initializer().
1320 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1321 ClassLoader::perf_class_init_selftime(),
1322 ClassLoader::perf_classes_inited(),
1323 jt->get_thread_stat()->perf_recursion_counts_addr(),
1324 jt->get_thread_stat()->perf_timers_addr(),
1325 PerfClassTraceTime::CLASS_CLINIT);
1326 call_class_initializer(THREAD);
1327 } else {
1328 // The elapsed time is so small it's not worth counting.
1329 if (UsePerfData) {
1330 ClassLoader::perf_classes_inited()->inc();
1331 }
1332 call_class_initializer(THREAD);
1333 }
1334 }
1335
1336 // Step 9
1337 if (!HAS_PENDING_EXCEPTION) {
1338 set_initialization_state_and_notify(fully_initialized, CHECK);
1339 DEBUG_ONLY(vtable().verify(tty, true);)
1340 CompilationPolicy::replay_training_at_init(this, THREAD);
1341 }
1342 else {
1343 // Step 10 and 11
1344 Handle e(THREAD, PENDING_EXCEPTION);
1345 CLEAR_PENDING_EXCEPTION;
1346 // JVMTI has already reported the pending exception
1347 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1348 JvmtiExport::clear_detected_exception(jt);
1349 {
1350 EXCEPTION_MARK;
1351 add_initialization_error(THREAD, e);
1352 set_initialization_state_and_notify(initialization_error, THREAD);
1353 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1354 // JVMTI has already reported the pending exception
1355 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1356 JvmtiExport::clear_detected_exception(jt);
1357 }
1358 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1359 if (e->is_a(vmClasses::Error_klass())) {
1360 THROW_OOP(e());
1361 } else {
1362 JavaCallArguments args(e);
1363 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1364 vmSymbols::throwable_void_signature(),
1365 &args);
1366 }
1367 }
1368 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1369 }
1370
1371
1372 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1373 Handle h_init_lock(THREAD, init_lock());
1374 if (h_init_lock() != nullptr) {
1375 ObjectLocker ol(h_init_lock, THREAD);
1376 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1377 set_init_state(state);
1378 ol.notify_all(CHECK);
1379 } else {
1380 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1381 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1382 set_init_state(state);
1383 }
1384 }
1385
1386 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1387 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1388 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1389 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1390
1391 DeoptimizationScope deopt_scope;
1392 {
1393 MutexLocker ml(current, Compile_lock);
1394
1395 set_init_state(InstanceKlass::loaded);
1396 // make sure init_state store is already done.
1397 // The compiler reads the hierarchy outside of the Compile_lock.
1398 // Access ordering is used to add to hierarchy.
1399
1400 // Link into hierarchy.
1401 append_to_sibling_list(); // add to superklass/sibling list
1402 process_interfaces(); // handle all "implements" declarations
1403
1404 // Now mark all code that depended on old class hierarchy.
1405 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1406 if (Universe::is_fully_initialized()) {
1407 CodeCache::mark_dependents_on(&deopt_scope, this);
1408 }
1409 }
1410 // Perform the deopt handshake outside Compile_lock.
1411 deopt_scope.deoptimize_marked();
1412 }
1413
1414
1415 InstanceKlass* InstanceKlass::implementor() const {
1416 InstanceKlass* volatile* ik = adr_implementor();
1417 if (ik == nullptr) {
1418 return nullptr;
1419 } else {
1420 // This load races with inserts, and therefore needs acquire.
1421 InstanceKlass* ikls = Atomic::load_acquire(ik);
1422 if (ikls != nullptr && !ikls->is_loader_alive()) {
1423 return nullptr; // don't return unloaded class
1424 } else {
1425 return ikls;
1426 }
1427 }
1428 }
1429
1430
1431 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1432 assert_locked_or_safepoint(Compile_lock);
1433 assert(is_interface(), "not interface");
1434 InstanceKlass* volatile* addr = adr_implementor();
1435 assert(addr != nullptr, "null addr");
1436 if (addr != nullptr) {
1437 Atomic::release_store(addr, ik);
1438 }
1439 }
1440
1441 int InstanceKlass::nof_implementors() const {
1442 InstanceKlass* ik = implementor();
1443 if (ik == nullptr) {
1444 return 0;
1445 } else if (ik != this) {
1446 return 1;
1447 } else {
1448 return 2;
1449 }
1450 }
1451
1452 // The embedded _implementor field can only record one implementor.
1453 // When there are more than one implementors, the _implementor field
1454 // is set to the interface Klass* itself. Following are the possible
1455 // values for the _implementor field:
1456 // null - no implementor
1457 // implementor Klass* - one implementor
1458 // self - more than one implementor
1459 //
1460 // The _implementor field only exists for interfaces.
1461 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1462 if (Universe::is_fully_initialized()) {
1463 assert_lock_strong(Compile_lock);
1464 }
1465 assert(is_interface(), "not interface");
1466 // Filter out my subinterfaces.
1467 // (Note: Interfaces are never on the subklass list.)
1468 if (ik->is_interface()) return;
1469
1470 // Filter out subclasses whose supers already implement me.
1471 // (Note: CHA must walk subclasses of direct implementors
1472 // in order to locate indirect implementors.)
1473 InstanceKlass* super_ik = ik->java_super();
1474 if (super_ik != nullptr && super_ik->implements_interface(this))
1475 // We only need to check one immediate superclass, since the
1476 // implements_interface query looks at transitive_interfaces.
1477 // Any supers of the super have the same (or fewer) transitive_interfaces.
1478 return;
1479
1480 InstanceKlass* iklass = implementor();
1481 if (iklass == nullptr) {
1482 set_implementor(ik);
1483 } else if (iklass != this && iklass != ik) {
1484 // There is already an implementor. Use itself as an indicator of
1485 // more than one implementors.
1486 set_implementor(this);
1487 }
1488
1489 // The implementor also implements the transitive_interfaces
1490 for (int index = 0; index < local_interfaces()->length(); index++) {
1491 local_interfaces()->at(index)->add_implementor(ik);
1492 }
1493 }
1494
1495 void InstanceKlass::init_implementor() {
1496 if (is_interface()) {
1497 set_implementor(nullptr);
1498 }
1499 }
1500
1501
1502 void InstanceKlass::process_interfaces() {
1503 // link this class into the implementors list of every interface it implements
1504 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1505 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1506 InstanceKlass* interf = local_interfaces()->at(i);
1507 assert(interf->is_interface(), "expected interface");
1508 interf->add_implementor(this);
1509 }
1510 }
1511
1512 bool InstanceKlass::can_be_primary_super_slow() const {
1513 if (is_interface())
1514 return false;
1515 else
1516 return Klass::can_be_primary_super_slow();
1517 }
1518
1519 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1520 Array<InstanceKlass*>* transitive_interfaces) {
1521 // The secondaries are the implemented interfaces.
1522 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1523 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1524 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1525 int num_secondaries = num_extra_slots + interfaces->length();
1526 if (num_secondaries == 0) {
1527 // Must share this for correct bootstrapping!
1528 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1529 return nullptr;
1530 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1531 // We will reuse the transitive interfaces list if we're certain
1532 // it's in hash order.
1533 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1534 set_secondary_supers(interfaces, bitmap);
1535 return nullptr;
1536 }
1537 // Copy transitive interfaces to a temporary growable array to be constructed
1538 // into the secondary super list with extra slots.
1539 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1540 for (int i = 0; i < interfaces->length(); i++) {
1541 secondaries->push(interfaces->at(i));
1542 }
1543 return secondaries;
1544 }
1545
1546 bool InstanceKlass::implements_interface(Klass* k) const {
1547 if (this == k) return true;
1548 assert(k->is_interface(), "should be an interface class");
1549 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1550 if (transitive_interfaces()->at(i) == k) {
1551 return true;
1552 }
1553 }
1554 return false;
1555 }
1556
1557 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1558 // Verify direct super interface
1559 if (this == k) return true;
1560 assert(k->is_interface(), "should be an interface class");
1561 for (int i = 0; i < local_interfaces()->length(); i++) {
1562 if (local_interfaces()->at(i) == k) {
1563 return true;
1564 }
1565 }
1566 return false;
1567 }
1568
1569 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1570 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1571 size_t size = objArrayOopDesc::object_size(length);
1572 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1573 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1574 /* do_zero */ true, CHECK_NULL);
1575 return o;
1576 }
1577
1578 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1579 if (TraceFinalizerRegistration) {
1580 tty->print("Registered ");
1581 i->print_value_on(tty);
1582 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1583 }
1584 instanceHandle h_i(THREAD, i);
1585 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1586 JavaValue result(T_VOID);
1587 JavaCallArguments args(h_i);
1588 methodHandle mh(THREAD, Universe::finalizer_register_method());
1589 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1590 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1591 return h_i();
1592 }
1593
1594 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1595 assert(!is_abstract() && !is_interface(), "Should not create this object");
1596 size_t size = size_helper(); // Query before forming handle.
1597 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1598 }
1599
1600 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1601 Klass* k = java_lang_Class::as_Klass(java_class);
1602 if (k == nullptr) {
1603 ResourceMark rm(THREAD);
1604 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1605 }
1606 InstanceKlass* ik = cast(k);
1607 ik->check_valid_for_instantiation(false, CHECK_NULL);
1608 ik->initialize(CHECK_NULL);
1609 return ik->allocate_instance(THREAD);
1610 }
1611
1612 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1613 return instanceHandle(THREAD, allocate_instance(THREAD));
1614 }
1615
1616 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1617 if (is_interface() || is_abstract()) {
1618 ResourceMark rm(THREAD);
1619 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1620 : vmSymbols::java_lang_InstantiationException(), external_name());
1621 }
1622 if (this == vmClasses::Class_klass()) {
1623 ResourceMark rm(THREAD);
1624 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1625 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1626 }
1627 }
1628
1629 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1630 // Need load-acquire for lock-free read
1631 if (array_klasses_acquire() == nullptr) {
1632
1633 // Recursively lock array allocation
1634 RecursiveLocker rl(MultiArray_lock, THREAD);
1635
1636 // Check if another thread created the array klass while we were waiting for the lock.
1637 if (array_klasses() == nullptr) {
1638 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1639 // use 'release' to pair with lock-free load
1640 release_set_array_klasses(k);
1641 }
1642 }
1643
1644 // array_klasses() will always be set at this point
1645 ObjArrayKlass* ak = array_klasses();
1646 assert(ak != nullptr, "should be set");
1647 return ak->array_klass(n, THREAD);
1648 }
1649
1650 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1651 // Need load-acquire for lock-free read
1652 ObjArrayKlass* oak = array_klasses_acquire();
1653 if (oak == nullptr) {
1654 return nullptr;
1655 } else {
1656 return oak->array_klass_or_null(n);
1657 }
1658 }
1659
1660 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1661 return array_klass(1, THREAD);
1662 }
1663
1664 ArrayKlass* InstanceKlass::array_klass_or_null() {
1665 return array_klass_or_null(1);
1666 }
1667
1668 static int call_class_initializer_counter = 0; // for debugging
1669
1670 Method* InstanceKlass::class_initializer() const {
1671 Method* clinit = find_method(
1672 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1673 if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1674 return clinit;
1675 }
1676 return nullptr;
1677 }
1678
1679 void InstanceKlass::call_class_initializer(TRAPS) {
1680 if (ReplayCompiles &&
1681 (ReplaySuppressInitializers == 1 ||
1682 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1683 // Hide the existence of the initializer for the purpose of replaying the compile
1684 return;
1685 }
1686
1687 #if INCLUDE_CDS
1688 // This is needed to ensure the consistency of the archived heap objects.
1689 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1690 AOTClassInitializer::call_runtime_setup(THREAD, this);
1691 return;
1692 } else if (has_archived_enum_objs()) {
1693 assert(is_shared(), "must be");
1694 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1695 if (initialized) {
1696 return;
1697 }
1698 }
1699 #endif
1700
1701 methodHandle h_method(THREAD, class_initializer());
1702 assert(!is_initialized(), "we cannot initialize twice");
1703 LogTarget(Info, class, init) lt;
1704 if (lt.is_enabled()) {
1705 ResourceMark rm(THREAD);
1706 LogStream ls(lt);
1707 ls.print("%d Initializing ", call_class_initializer_counter++);
1708 name()->print_value_on(&ls);
1709 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1710 h_method() == nullptr ? "(no method)" : "", p2i(this),
1711 THREAD->name());
1712 }
1713 if (h_method() != nullptr) {
1714 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1715 JavaCallArguments args; // No arguments
1716 JavaValue result(T_VOID);
1717 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1718 }
1719 }
1720
1721 // If a class that implements this interface is initialized, is the JVM required
1722 // to first execute a <clinit> method declared in this interface,
1723 // or (if also_check_supers==true) any of the super types of this interface?
1724 //
1725 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1726 // an interface, then let SC be its superclass and let SI1, ..., SIn
1727 // be all superinterfaces of C (whether direct or indirect) that
1728 // declare at least one non-abstract, non-static method.
1729 //
1730 // So when an interface is initialized, it does not look at its
1731 // supers. But a proper class will ensure that all of its supers have
1732 // run their <clinit> methods, except that it disregards interfaces
1733 // that lack a non-static concrete method (i.e., a default method).
1734 // Therefore, you should probably call this method only when the
1735 // current class is a super of some proper class, not an interface.
1736 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1737 assert(is_interface(), "must be");
1738
1739 if (!has_nonstatic_concrete_methods()) {
1740 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1741 return false;
1742 }
1743
1744 // JVMS 5.5. Initialization
1745 // ...If C is an interface that declares a non-abstract,
1746 // non-static method, the initialization of a class that
1747 // implements C directly or indirectly.
1748 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1749 return true;
1750 }
1751 if (also_check_supers) {
1752 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1753 for (int i = 0; i < all_ifs->length(); ++i) {
1754 InstanceKlass* super_intf = all_ifs->at(i);
1755 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1756 return true;
1757 }
1758 }
1759 }
1760 return false;
1761 }
1762
1763 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1764 InterpreterOopMap* entry_for) {
1765 // Lazily create the _oop_map_cache at first request.
1766 // Load_acquire is needed to safely get instance published with CAS by another thread.
1767 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1768 if (oop_map_cache == nullptr) {
1769 // Try to install new instance atomically.
1770 oop_map_cache = new OopMapCache();
1771 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1772 if (other != nullptr) {
1773 // Someone else managed to install before us, ditch local copy and use the existing one.
1774 delete oop_map_cache;
1775 oop_map_cache = other;
1776 }
1777 }
1778 // _oop_map_cache is constant after init; lookup below does its own locking.
1779 oop_map_cache->lookup(method, bci, entry_for);
1780 }
1781
1782 bool InstanceKlass::contains_field_offset(int offset) {
1783 fieldDescriptor fd;
1784 return find_field_from_offset(offset, false, &fd);
1785 }
1786
1787 FieldInfo InstanceKlass::field(int index) const {
1788 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1789 if (fs.index() == index) {
1790 return fs.to_FieldInfo();
1791 }
1792 }
1793 fatal("Field not found");
1794 return FieldInfo();
1795 }
1796
1797 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1798 JavaFieldStream fs(this);
1799 if (fs.lookup(name, sig)) {
1800 assert(fs.name() == name, "name must match");
1801 assert(fs.signature() == sig, "signature must match");
1802 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1803 return true;
1804 }
1805 return false;
1806 }
1807
1808
1809 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1810 const int n = local_interfaces()->length();
1811 for (int i = 0; i < n; i++) {
1812 Klass* intf1 = local_interfaces()->at(i);
1813 assert(intf1->is_interface(), "just checking type");
1814 // search for field in current interface
1815 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1816 assert(fd->is_static(), "interface field must be static");
1817 return intf1;
1818 }
1819 // search for field in direct superinterfaces
1820 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1821 if (intf2 != nullptr) return intf2;
1822 }
1823 // otherwise field lookup fails
1824 return nullptr;
1825 }
1826
1827
1828 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1829 // search order according to newest JVM spec (5.4.3.2, p.167).
1830 // 1) search for field in current klass
1831 if (find_local_field(name, sig, fd)) {
1832 return const_cast<InstanceKlass*>(this);
1833 }
1834 // 2) search for field recursively in direct superinterfaces
1835 { Klass* intf = find_interface_field(name, sig, fd);
1836 if (intf != nullptr) return intf;
1837 }
1838 // 3) apply field lookup recursively if superclass exists
1839 { Klass* supr = super();
1840 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1841 }
1842 // 4) otherwise field lookup fails
1843 return nullptr;
1844 }
1845
1846
1847 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1848 // search order according to newest JVM spec (5.4.3.2, p.167).
1849 // 1) search for field in current klass
1850 if (find_local_field(name, sig, fd)) {
1851 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1852 }
1853 // 2) search for field recursively in direct superinterfaces
1854 if (is_static) {
1855 Klass* intf = find_interface_field(name, sig, fd);
1856 if (intf != nullptr) return intf;
1857 }
1858 // 3) apply field lookup recursively if superclass exists
1859 { Klass* supr = super();
1860 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1861 }
1862 // 4) otherwise field lookup fails
1863 return nullptr;
1864 }
1865
1866
1867 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1868 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1869 if (fs.offset() == offset) {
1870 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1871 if (fd->is_static() == is_static) return true;
1872 }
1873 }
1874 return false;
1875 }
1876
1877
1878 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1879 Klass* klass = const_cast<InstanceKlass*>(this);
1880 while (klass != nullptr) {
1881 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1882 return true;
1883 }
1884 klass = klass->super();
1885 }
1886 return false;
1887 }
1888
1889
1890 void InstanceKlass::methods_do(void f(Method* method)) {
1891 // Methods aren't stable until they are loaded. This can be read outside
1892 // a lock through the ClassLoaderData for profiling
1893 // Redefined scratch classes are on the list and need to be cleaned
1894 if (!is_loaded() && !is_scratch_class()) {
1895 return;
1896 }
1897
1898 int len = methods()->length();
1899 for (int index = 0; index < len; index++) {
1900 Method* m = methods()->at(index);
1901 assert(m->is_method(), "must be method");
1902 f(m);
1903 }
1904 }
1905
1906
1907 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1908 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1909 if (fs.access_flags().is_static()) {
1910 fieldDescriptor& fd = fs.field_descriptor();
1911 cl->do_field(&fd);
1912 }
1913 }
1914 }
1915
1916
1917 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1918 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1919 if (fs.access_flags().is_static()) {
1920 fieldDescriptor& fd = fs.field_descriptor();
1921 f(&fd, mirror, CHECK);
1922 }
1923 }
1924 }
1925
1926 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1927 InstanceKlass* super = superklass();
1928 if (super != nullptr) {
1929 super->do_nonstatic_fields(cl);
1930 }
1931 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1932 fieldDescriptor& fd = fs.field_descriptor();
1933 if (!fd.is_static()) {
1934 cl->do_field(&fd);
1935 }
1936 }
1937 }
1938
1939 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1940 return a->offset() - b->offset();
1941 }
1942
1943 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1944 InstanceKlass* super = superklass();
1945 if (super != nullptr) {
1946 super->print_nonstatic_fields(cl);
1947 }
1948 ResourceMark rm;
1949 // In DebugInfo nonstatic fields are sorted by offset.
1950 GrowableArray<FieldInfo> fields_sorted;
1951 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1952 if (!fs.access_flags().is_static()) {
1953 fields_sorted.push(fs.to_FieldInfo());
1954 }
1955 }
1956 int length = fields_sorted.length();
1957 if (length > 0) {
1958 fields_sorted.sort(compare_fields_by_offset);
1959 fieldDescriptor fd;
1960 for (int i = 0; i < length; i++) {
1961 fd.reinitialize(this, fields_sorted.at(i));
1962 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1963 cl->do_field(&fd);
1964 }
1965 }
1966 }
1967
1968 #ifdef ASSERT
1969 static int linear_search(const Array<Method*>* methods,
1970 const Symbol* name,
1971 const Symbol* signature) {
1972 const int len = methods->length();
1973 for (int index = 0; index < len; index++) {
1974 const Method* const m = methods->at(index);
1975 assert(m->is_method(), "must be method");
1976 if (m->signature() == signature && m->name() == name) {
1977 return index;
1978 }
1979 }
1980 return -1;
1981 }
1982 #endif
1983
1984 bool InstanceKlass::_disable_method_binary_search = false;
1985
1986 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1987 int len = methods->length();
1988 int l = 0;
1989 int h = len - 1;
1990 while (l <= h) {
1991 Method* m = methods->at(l);
1992 if (m->name() == name) {
1993 return l;
1994 }
1995 l++;
1996 }
1997 return -1;
1998 }
1999
2000 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2001 if (_disable_method_binary_search) {
2002 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2003 // At the final stage of dynamic dumping, the methods array may not be sorted
2004 // by ascending addresses of their names, so we can't use binary search anymore.
2005 // However, methods with the same name are still laid out consecutively inside the
2006 // methods array, so let's look for the first one that matches.
2007 return linear_search(methods, name);
2008 }
2009
2010 int len = methods->length();
2011 int l = 0;
2012 int h = len - 1;
2013
2014 // methods are sorted by ascending addresses of their names, so do binary search
2015 while (l <= h) {
2016 int mid = (l + h) >> 1;
2017 Method* m = methods->at(mid);
2018 assert(m->is_method(), "must be method");
2019 int res = m->name()->fast_compare(name);
2020 if (res == 0) {
2021 return mid;
2022 } else if (res < 0) {
2023 l = mid + 1;
2024 } else {
2025 h = mid - 1;
2026 }
2027 }
2028 return -1;
2029 }
2030
2031 // find_method looks up the name/signature in the local methods array
2032 Method* InstanceKlass::find_method(const Symbol* name,
2033 const Symbol* signature) const {
2034 return find_method_impl(name, signature,
2035 OverpassLookupMode::find,
2036 StaticLookupMode::find,
2037 PrivateLookupMode::find);
2038 }
2039
2040 Method* InstanceKlass::find_method_impl(const Symbol* name,
2041 const Symbol* signature,
2042 OverpassLookupMode overpass_mode,
2043 StaticLookupMode static_mode,
2044 PrivateLookupMode private_mode) const {
2045 return InstanceKlass::find_method_impl(methods(),
2046 name,
2047 signature,
2048 overpass_mode,
2049 static_mode,
2050 private_mode);
2051 }
2052
2053 // find_instance_method looks up the name/signature in the local methods array
2054 // and skips over static methods
2055 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2056 const Symbol* name,
2057 const Symbol* signature,
2058 PrivateLookupMode private_mode) {
2059 Method* const meth = InstanceKlass::find_method_impl(methods,
2060 name,
2061 signature,
2062 OverpassLookupMode::find,
2063 StaticLookupMode::skip,
2064 private_mode);
2065 assert(((meth == nullptr) || !meth->is_static()),
2066 "find_instance_method should have skipped statics");
2067 return meth;
2068 }
2069
2070 // find_instance_method looks up the name/signature in the local methods array
2071 // and skips over static methods
2072 Method* InstanceKlass::find_instance_method(const Symbol* name,
2073 const Symbol* signature,
2074 PrivateLookupMode private_mode) const {
2075 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2076 }
2077
2078 // Find looks up the name/signature in the local methods array
2079 // and filters on the overpass, static and private flags
2080 // This returns the first one found
2081 // note that the local methods array can have up to one overpass, one static
2082 // and one instance (private or not) with the same name/signature
2083 Method* InstanceKlass::find_local_method(const Symbol* name,
2084 const Symbol* signature,
2085 OverpassLookupMode overpass_mode,
2086 StaticLookupMode static_mode,
2087 PrivateLookupMode private_mode) const {
2088 return InstanceKlass::find_method_impl(methods(),
2089 name,
2090 signature,
2091 overpass_mode,
2092 static_mode,
2093 private_mode);
2094 }
2095
2096 // Find looks up the name/signature in the local methods array
2097 // and filters on the overpass, static and private flags
2098 // This returns the first one found
2099 // note that the local methods array can have up to one overpass, one static
2100 // and one instance (private or not) with the same name/signature
2101 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2102 const Symbol* name,
2103 const Symbol* signature,
2104 OverpassLookupMode overpass_mode,
2105 StaticLookupMode static_mode,
2106 PrivateLookupMode private_mode) {
2107 return InstanceKlass::find_method_impl(methods,
2108 name,
2109 signature,
2110 overpass_mode,
2111 static_mode,
2112 private_mode);
2113 }
2114
2115 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2116 const Symbol* name,
2117 const Symbol* signature) {
2118 return InstanceKlass::find_method_impl(methods,
2119 name,
2120 signature,
2121 OverpassLookupMode::find,
2122 StaticLookupMode::find,
2123 PrivateLookupMode::find);
2124 }
2125
2126 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2127 const Symbol* name,
2128 const Symbol* signature,
2129 OverpassLookupMode overpass_mode,
2130 StaticLookupMode static_mode,
2131 PrivateLookupMode private_mode) {
2132 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2133 return hit >= 0 ? methods->at(hit): nullptr;
2134 }
2135
2136 // true if method matches signature and conforms to skipping_X conditions.
2137 static bool method_matches(const Method* m,
2138 const Symbol* signature,
2139 bool skipping_overpass,
2140 bool skipping_static,
2141 bool skipping_private) {
2142 return ((m->signature() == signature) &&
2143 (!skipping_overpass || !m->is_overpass()) &&
2144 (!skipping_static || !m->is_static()) &&
2145 (!skipping_private || !m->is_private()));
2146 }
2147
2148 // Used directly for default_methods to find the index into the
2149 // default_vtable_indices, and indirectly by find_method
2150 // find_method_index looks in the local methods array to return the index
2151 // of the matching name/signature. If, overpass methods are being ignored,
2152 // the search continues to find a potential non-overpass match. This capability
2153 // is important during method resolution to prefer a static method, for example,
2154 // over an overpass method.
2155 // There is the possibility in any _method's array to have the same name/signature
2156 // for a static method, an overpass method and a local instance method
2157 // To correctly catch a given method, the search criteria may need
2158 // to explicitly skip the other two. For local instance methods, it
2159 // is often necessary to skip private methods
2160 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2161 const Symbol* name,
2162 const Symbol* signature,
2163 OverpassLookupMode overpass_mode,
2164 StaticLookupMode static_mode,
2165 PrivateLookupMode private_mode) {
2166 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2167 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2168 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2169 const int hit = quick_search(methods, name);
2170 if (hit != -1) {
2171 const Method* const m = methods->at(hit);
2172
2173 // Do linear search to find matching signature. First, quick check
2174 // for common case, ignoring overpasses if requested.
2175 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2176 return hit;
2177 }
2178
2179 // search downwards through overloaded methods
2180 int i;
2181 for (i = hit - 1; i >= 0; --i) {
2182 const Method* const m = methods->at(i);
2183 assert(m->is_method(), "must be method");
2184 if (m->name() != name) {
2185 break;
2186 }
2187 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2188 return i;
2189 }
2190 }
2191 // search upwards
2192 for (i = hit + 1; i < methods->length(); ++i) {
2193 const Method* const m = methods->at(i);
2194 assert(m->is_method(), "must be method");
2195 if (m->name() != name) {
2196 break;
2197 }
2198 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2199 return i;
2200 }
2201 }
2202 // not found
2203 #ifdef ASSERT
2204 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2205 linear_search(methods, name, signature);
2206 assert(-1 == index, "binary search should have found entry %d", index);
2207 #endif
2208 }
2209 return -1;
2210 }
2211
2212 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2213 return find_method_by_name(methods(), name, end);
2214 }
2215
2216 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2217 const Symbol* name,
2218 int* end_ptr) {
2219 assert(end_ptr != nullptr, "just checking");
2220 int start = quick_search(methods, name);
2221 int end = start + 1;
2222 if (start != -1) {
2223 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2224 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2225 *end_ptr = end;
2226 return start;
2227 }
2228 return -1;
2229 }
2230
2231 // uncached_lookup_method searches both the local class methods array and all
2232 // superclasses methods arrays, skipping any overpass methods in superclasses,
2233 // and possibly skipping private methods.
2234 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2235 const Symbol* signature,
2236 OverpassLookupMode overpass_mode,
2237 PrivateLookupMode private_mode) const {
2238 OverpassLookupMode overpass_local_mode = overpass_mode;
2239 const Klass* klass = this;
2240 while (klass != nullptr) {
2241 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2242 signature,
2243 overpass_local_mode,
2244 StaticLookupMode::find,
2245 private_mode);
2246 if (method != nullptr) {
2247 return method;
2248 }
2249 klass = klass->super();
2250 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2251 }
2252 return nullptr;
2253 }
2254
2255 #ifdef ASSERT
2256 // search through class hierarchy and return true if this class or
2257 // one of the superclasses was redefined
2258 bool InstanceKlass::has_redefined_this_or_super() const {
2259 const Klass* klass = this;
2260 while (klass != nullptr) {
2261 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2262 return true;
2263 }
2264 klass = klass->super();
2265 }
2266 return false;
2267 }
2268 #endif
2269
2270 // lookup a method in the default methods list then in all transitive interfaces
2271 // Do NOT return private or static methods
2272 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2273 Symbol* signature) const {
2274 Method* m = nullptr;
2275 if (default_methods() != nullptr) {
2276 m = find_method(default_methods(), name, signature);
2277 }
2278 // Look up interfaces
2279 if (m == nullptr) {
2280 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2281 }
2282 return m;
2283 }
2284
2285 // lookup a method in all the interfaces that this class implements
2286 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2287 // They should only be found in the initial InterfaceMethodRef
2288 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2289 Symbol* signature,
2290 DefaultsLookupMode defaults_mode) const {
2291 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2292 int num_ifs = all_ifs->length();
2293 InstanceKlass *ik = nullptr;
2294 for (int i = 0; i < num_ifs; i++) {
2295 ik = all_ifs->at(i);
2296 Method* m = ik->lookup_method(name, signature);
2297 if (m != nullptr && m->is_public() && !m->is_static() &&
2298 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2299 return m;
2300 }
2301 }
2302 return nullptr;
2303 }
2304
2305 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2306 :_st(st), _verbose(verbose) {
2307 ResourceMark rm;
2308 _st->print("%-18s ", "KlassAddr");
2309 _st->print("%-4s ", "Size");
2310 _st->print("%-20s ", "State");
2311 _st->print("%-7s ", "Flags");
2312 _st->print("%-5s ", "ClassName");
2313 _st->cr();
2314 }
2315
2316 void PrintClassClosure::do_klass(Klass* k) {
2317 ResourceMark rm;
2318 // klass pointer
2319 _st->print(PTR_FORMAT " ", p2i(k));
2320 // klass size
2321 _st->print("%4d ", k->size());
2322 // initialization state
2323 if (k->is_instance_klass()) {
2324 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2325 } else {
2326 _st->print("%-20s ","");
2327 }
2328 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2329 char buf[10];
2330 int i = 0;
2331 if (k->has_finalizer()) buf[i++] = 'F';
2332 if (k->is_instance_klass()) {
2333 InstanceKlass* ik = InstanceKlass::cast(k);
2334 if (ik->has_final_method()) buf[i++] = 'f';
2335 if (ik->is_rewritten()) buf[i++] = 'W';
2336 if (ik->is_contended()) buf[i++] = 'C';
2337 if (ik->has_been_redefined()) buf[i++] = 'R';
2338 if (ik->is_shared()) buf[i++] = 'S';
2339 }
2340 buf[i++] = '\0';
2341 _st->print("%-7s ", buf);
2342 // klass name
2343 _st->print("%-5s ", k->external_name());
2344 // end
2345 _st->cr();
2346 if (_verbose) {
2347 k->print_on(_st);
2348 }
2349 }
2350
2351 /* jni_id_for for jfieldIds only */
2352 JNIid* InstanceKlass::jni_id_for(int offset) {
2353 MutexLocker ml(JfieldIdCreation_lock);
2354 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2355 if (probe == nullptr) {
2356 // Allocate new static field identifier
2357 probe = new JNIid(this, offset, jni_ids());
2358 set_jni_ids(probe);
2359 }
2360 return probe;
2361 }
2362
2363 u2 InstanceKlass::enclosing_method_data(int offset) const {
2364 const Array<jushort>* const inner_class_list = inner_classes();
2365 if (inner_class_list == nullptr) {
2366 return 0;
2367 }
2368 const int length = inner_class_list->length();
2369 if (length % inner_class_next_offset == 0) {
2370 return 0;
2371 }
2372 const int index = length - enclosing_method_attribute_size;
2373 assert(offset < enclosing_method_attribute_size, "invalid offset");
2374 return inner_class_list->at(index + offset);
2375 }
2376
2377 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2378 u2 method_index) {
2379 Array<jushort>* inner_class_list = inner_classes();
2380 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2381 int length = inner_class_list->length();
2382 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2383 int index = length - enclosing_method_attribute_size;
2384 inner_class_list->at_put(
2385 index + enclosing_method_class_index_offset, class_index);
2386 inner_class_list->at_put(
2387 index + enclosing_method_method_index_offset, method_index);
2388 }
2389 }
2390
2391 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2392 if (method->is_old() && !method->is_obsolete()) {
2393 // If the method passed in is old (but not obsolete), use the current version.
2394 method = method_with_idnum((int)idnum);
2395 assert(method != nullptr, "old and but not obsolete, so should exist");
2396 }
2397 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2398 Atomic::release_store(&jmeths[idnum + 1], new_id);
2399 return new_id;
2400 }
2401
2402 // Allocate the jmethodID cache.
2403 static jmethodID* create_jmethod_id_cache(size_t size) {
2404 jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2405 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2406 // cache size is stored in element[0], other elements offset by one
2407 jmeths[0] = (jmethodID)size;
2408 return jmeths;
2409 }
2410
2411 // When reading outside a lock, use this.
2412 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2413 return Atomic::load_acquire(&_methods_jmethod_ids);
2414 }
2415
2416 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2417 Atomic::release_store(&_methods_jmethod_ids, jmeths);
2418 }
2419
2420 // Lookup or create a jmethodID.
2421 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2422 int idnum = method->method_idnum();
2423 jmethodID* jmeths = methods_jmethod_ids_acquire();
2424
2425 // We use a double-check locking idiom here because this cache is
2426 // performance sensitive. In the normal system, this cache only
2427 // transitions from null to non-null which is safe because we use
2428 // release_set_methods_jmethod_ids() to advertise the new cache.
2429 // A partially constructed cache should never be seen by a racing
2430 // thread. We also use release_store() to save a new jmethodID
2431 // in the cache so a partially constructed jmethodID should never be
2432 // seen either. Cache reads of existing jmethodIDs proceed without a
2433 // lock, but cache writes of a new jmethodID requires uniqueness and
2434 // creation of the cache itself requires no leaks so a lock is
2435 // acquired in those two cases.
2436 //
2437 // If the RedefineClasses() API has been used, then this cache grows
2438 // in the redefinition safepoint.
2439
2440 if (jmeths == nullptr) {
2441 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2442 jmeths = _methods_jmethod_ids;
2443 // Still null?
2444 if (jmeths == nullptr) {
2445 size_t size = idnum_allocated_count();
2446 assert(size > (size_t)idnum, "should already have space");
2447 jmeths = create_jmethod_id_cache(size);
2448 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2449
2450 // publish jmeths
2451 release_set_methods_jmethod_ids(jmeths);
2452 return new_id;
2453 }
2454 }
2455
2456 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2457 if (id == nullptr) {
2458 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2459 id = jmeths[idnum + 1];
2460 // Still null?
2461 if (id == nullptr) {
2462 return update_jmethod_id(jmeths, method, idnum);
2463 }
2464 }
2465 return id;
2466 }
2467
2468 void InstanceKlass::update_methods_jmethod_cache() {
2469 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2470 jmethodID* cache = _methods_jmethod_ids;
2471 if (cache != nullptr) {
2472 size_t size = idnum_allocated_count();
2473 size_t old_size = (size_t)cache[0];
2474 if (old_size < size + 1) {
2475 // Allocate a larger one and copy entries to the new one.
2476 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2477 jmethodID* new_cache = create_jmethod_id_cache(size);
2478
2479 for (int i = 1; i <= (int)old_size; i++) {
2480 new_cache[i] = cache[i];
2481 }
2482 _methods_jmethod_ids = new_cache;
2483 FREE_C_HEAP_ARRAY(jmethodID, cache);
2484 }
2485 }
2486 }
2487
2488 // Make a jmethodID for all methods in this class. This makes getting all method
2489 // ids much, much faster with classes with more than 8
2490 // methods, and has a *substantial* effect on performance with jvmti
2491 // code that loads all jmethodIDs for all classes.
2492 void InstanceKlass::make_methods_jmethod_ids() {
2493 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2494 jmethodID* jmeths = _methods_jmethod_ids;
2495 if (jmeths == nullptr) {
2496 jmeths = create_jmethod_id_cache(idnum_allocated_count());
2497 release_set_methods_jmethod_ids(jmeths);
2498 }
2499
2500 int length = methods()->length();
2501 for (int index = 0; index < length; index++) {
2502 Method* m = methods()->at(index);
2503 int idnum = m->method_idnum();
2504 assert(!m->is_old(), "should not have old methods or I'm confused");
2505 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2506 if (!m->is_overpass() && // skip overpasses
2507 id == nullptr) {
2508 id = Method::make_jmethod_id(class_loader_data(), m);
2509 Atomic::release_store(&jmeths[idnum + 1], id);
2510 }
2511 }
2512 }
2513
2514 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2515 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2516 int idnum = method->method_idnum();
2517 jmethodID* jmeths = methods_jmethod_ids_acquire();
2518 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2519 }
2520
2521 inline DependencyContext InstanceKlass::dependencies() {
2522 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2523 return dep_context;
2524 }
2525
2526 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2527 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2528 }
2529
2530 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2531 assert_lock_strong(CodeCache_lock);
2532 dependencies().add_dependent_nmethod(nm);
2533 }
2534
2535 void InstanceKlass::clean_dependency_context() {
2536 dependencies().clean_unloading_dependents();
2537 }
2538
2539 #ifndef PRODUCT
2540 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2541 dependencies().print_dependent_nmethods(verbose);
2542 }
2543
2544 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2545 return dependencies().is_dependent_nmethod(nm);
2546 }
2547 #endif //PRODUCT
2548
2549 void InstanceKlass::clean_weak_instanceklass_links() {
2550 clean_implementors_list();
2551 clean_method_data();
2552 }
2553
2554 void InstanceKlass::clean_implementors_list() {
2555 assert(is_loader_alive(), "this klass should be live");
2556 if (is_interface()) {
2557 assert (ClassUnloading, "only called for ClassUnloading");
2558 for (;;) {
2559 // Use load_acquire due to competing with inserts
2560 InstanceKlass* volatile* iklass = adr_implementor();
2561 assert(iklass != nullptr, "Klass must not be null");
2562 InstanceKlass* impl = Atomic::load_acquire(iklass);
2563 if (impl != nullptr && !impl->is_loader_alive()) {
2564 // null this field, might be an unloaded instance klass or null
2565 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2566 // Successfully unlinking implementor.
2567 if (log_is_enabled(Trace, class, unload)) {
2568 ResourceMark rm;
2569 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2570 }
2571 return;
2572 }
2573 } else {
2574 return;
2575 }
2576 }
2577 }
2578 }
2579
2580 void InstanceKlass::clean_method_data() {
2581 for (int m = 0; m < methods()->length(); m++) {
2582 MethodData* mdo = methods()->at(m)->method_data();
2583 if (mdo != nullptr) {
2584 mdo->clean_method_data(/*always_clean*/false);
2585 }
2586 }
2587 }
2588
2589 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2590 Klass::metaspace_pointers_do(it);
2591
2592 if (log_is_enabled(Trace, aot)) {
2593 ResourceMark rm;
2594 log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2595 }
2596
2597 it->push(&_annotations);
2598 it->push((Klass**)&_array_klasses);
2599 if (!is_rewritten()) {
2600 it->push(&_constants, MetaspaceClosure::_writable);
2601 } else {
2602 it->push(&_constants);
2603 }
2604 it->push(&_inner_classes);
2605 #if INCLUDE_JVMTI
2606 it->push(&_previous_versions);
2607 #endif
2608 #if INCLUDE_CDS
2609 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2610 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2611 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2612 // The length check on the _methods is necessary because classes which don't have any
2613 // methods share the Universe::_the_empty_method_array which is in the RO region.
2614 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2615 // To handle jsr bytecode, new Method* maybe stored into _methods
2616 it->push(&_methods, MetaspaceClosure::_writable);
2617 } else {
2618 #endif
2619 it->push(&_methods);
2620 #if INCLUDE_CDS
2621 }
2622 #endif
2623 it->push(&_default_methods);
2624 it->push(&_local_interfaces);
2625 it->push(&_transitive_interfaces);
2626 it->push(&_method_ordering);
2627 if (!is_rewritten()) {
2628 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2629 } else {
2630 it->push(&_default_vtable_indices);
2631 }
2632
2633 it->push(&_fieldinfo_stream);
2634 it->push(&_fieldinfo_search_table);
2635 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2636 it->push(&_fields_status, MetaspaceClosure::_writable);
2637
2638 if (itable_length() > 0) {
2639 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2640 int method_table_offset_in_words = ioe->offset()/wordSize;
2641 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2642
2643 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2644 / itableOffsetEntry::size();
2645
2646 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2647 if (ioe->interface_klass() != nullptr) {
2648 it->push(ioe->interface_klass_addr());
2649 itableMethodEntry* ime = ioe->first_method_entry(this);
2650 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2651 for (int index = 0; index < n; index ++) {
2652 it->push(ime[index].method_addr());
2653 }
2654 }
2655 }
2656 }
2657
2658 it->push(&_nest_host);
2659 it->push(&_nest_members);
2660 it->push(&_permitted_subclasses);
2661 it->push(&_record_components);
2662 }
2663
2664 #if INCLUDE_CDS
2665 void InstanceKlass::remove_unshareable_info() {
2666
2667 if (is_linked()) {
2668 assert(can_be_verified_at_dumptime(), "must be");
2669 // Remember this so we can avoid walking the hierarchy at runtime.
2670 set_verified_at_dump_time();
2671 }
2672
2673 _misc_flags.set_has_init_deps_processed(false);
2674
2675 Klass::remove_unshareable_info();
2676
2677 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2678 // Classes are attempted to link during dumping and may fail,
2679 // but these classes are still in the dictionary and class list in CLD.
2680 // If the class has failed verification, there is nothing else to remove.
2681 return;
2682 }
2683
2684 // Reset to the 'allocated' state to prevent any premature accessing to
2685 // a shared class at runtime while the class is still being loaded and
2686 // restored. A class' init_state is set to 'loaded' at runtime when it's
2687 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2688 _init_state = allocated;
2689
2690 { // Otherwise this needs to take out the Compile_lock.
2691 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2692 init_implementor();
2693 }
2694
2695 // Call remove_unshareable_info() on other objects that belong to this class, except
2696 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2697 // ArchiveBuilder::make_klasses_shareable(),
2698
2699 for (int i = 0; i < methods()->length(); i++) {
2700 Method* m = methods()->at(i);
2701 m->remove_unshareable_info();
2702 }
2703
2704 // do array classes also.
2705 if (array_klasses() != nullptr) {
2706 array_klasses()->remove_unshareable_info();
2707 }
2708
2709 // These are not allocated from metaspace. They are safe to set to null.
2710 _source_debug_extension = nullptr;
2711 _dep_context = nullptr;
2712 _osr_nmethods_head = nullptr;
2713 #if INCLUDE_JVMTI
2714 _breakpoints = nullptr;
2715 _previous_versions = nullptr;
2716 _cached_class_file = nullptr;
2717 _jvmti_cached_class_field_map = nullptr;
2718 #endif
2719
2720 _init_thread = nullptr;
2721 _methods_jmethod_ids = nullptr;
2722 _jni_ids = nullptr;
2723 _oop_map_cache = nullptr;
2724 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2725 // keep _nest_host
2726 } else {
2727 // clear _nest_host to ensure re-load at runtime
2728 _nest_host = nullptr;
2729 }
2730 init_shared_package_entry();
2731 _dep_context_last_cleaned = 0;
2732 DEBUG_ONLY(_shared_class_load_count = 0);
2733
2734 remove_unshareable_flags();
2735
2736 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2737 }
2738
2739 void InstanceKlass::remove_unshareable_flags() {
2740 // clear all the flags/stats that shouldn't be in the archived version
2741 assert(!is_scratch_class(), "must be");
2742 assert(!has_been_redefined(), "must be");
2743 #if INCLUDE_JVMTI
2744 set_is_being_redefined(false);
2745 #endif
2746 set_has_resolved_methods(false);
2747 }
2748
2749 void InstanceKlass::remove_java_mirror() {
2750 Klass::remove_java_mirror();
2751
2752 // do array classes also.
2753 if (array_klasses() != nullptr) {
2754 array_klasses()->remove_java_mirror();
2755 }
2756 }
2757
2758 void InstanceKlass::init_shared_package_entry() {
2759 assert(CDSConfig::is_dumping_archive(), "must be");
2760 #if !INCLUDE_CDS_JAVA_HEAP
2761 _package_entry = nullptr;
2762 #else
2763 if (CDSConfig::is_dumping_full_module_graph()) {
2764 if (defined_by_other_loaders()) {
2765 _package_entry = nullptr;
2766 } else {
2767 _package_entry = PackageEntry::get_archived_entry(_package_entry);
2768 }
2769 } else if (CDSConfig::is_dumping_dynamic_archive() &&
2770 CDSConfig::is_using_full_module_graph() &&
2771 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
2772 // _package_entry is an archived package in the base archive. Leave it as is.
2773 } else {
2774 _package_entry = nullptr;
2775 }
2776 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2777 #endif
2778 }
2779
2780 void InstanceKlass::compute_has_loops_flag_for_methods() {
2781 Array<Method*>* methods = this->methods();
2782 for (int index = 0; index < methods->length(); ++index) {
2783 Method* m = methods->at(index);
2784 if (!m->is_overpass()) { // work around JDK-8305771
2785 m->compute_has_loops_flag();
2786 }
2787 }
2788 }
2789
2790 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2791 PackageEntry* pkg_entry, TRAPS) {
2792 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2793 // before the InstanceKlass is added to the SystemDictionary. Make
2794 // sure the current state is <loaded.
2795 assert(!is_loaded(), "invalid init state");
2796 assert(!shared_loading_failed(), "Must not try to load failed class again");
2797 set_package(loader_data, pkg_entry, CHECK);
2798 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2799
2800 Array<Method*>* methods = this->methods();
2801 int num_methods = methods->length();
2802 for (int index = 0; index < num_methods; ++index) {
2803 methods->at(index)->restore_unshareable_info(CHECK);
2804 }
2805 #if INCLUDE_JVMTI
2806 if (JvmtiExport::has_redefined_a_class()) {
2807 // Reinitialize vtable because RedefineClasses may have changed some
2808 // entries in this vtable for super classes so the CDS vtable might
2809 // point to old or obsolete entries. RedefineClasses doesn't fix up
2810 // vtables in the shared system dictionary, only the main one.
2811 // It also redefines the itable too so fix that too.
2812 // First fix any default methods that point to a super class that may
2813 // have been redefined.
2814 bool trace_name_printed = false;
2815 adjust_default_methods(&trace_name_printed);
2816 if (verified_at_dump_time()) {
2817 // Initialize vtable and itable for classes which can be verified at dump time.
2818 // Unlinked classes such as old classes with major version < 50 cannot be verified
2819 // at dump time.
2820 vtable().initialize_vtable();
2821 itable().initialize_itable();
2822 }
2823 }
2824 #endif // INCLUDE_JVMTI
2825
2826 // restore constant pool resolved references
2827 constants()->restore_unshareable_info(CHECK);
2828
2829 if (array_klasses() != nullptr) {
2830 // To get a consistent list of classes we need MultiArray_lock to ensure
2831 // array classes aren't observed while they are being restored.
2832 RecursiveLocker rl(MultiArray_lock, THREAD);
2833 assert(this == array_klasses()->bottom_klass(), "sanity");
2834 // Array classes have null protection domain.
2835 // --> see ArrayKlass::complete_create_array_klass()
2836 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2837 }
2838
2839 // Initialize @ValueBased class annotation if not already set in the archived klass.
2840 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2841 set_is_value_based();
2842 }
2843
2844 DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2845 }
2846
2847 // Check if a class or any of its supertypes has a version older than 50.
2848 // CDS will not perform verification of old classes during dump time because
2849 // without changing the old verifier, the verification constraint cannot be
2850 // retrieved during dump time.
2851 // Verification of archived old classes will be performed during run time.
2852 bool InstanceKlass::can_be_verified_at_dumptime() const {
2853 if (MetaspaceShared::is_in_shared_metaspace(this)) {
2854 // This is a class that was dumped into the base archive, so we know
2855 // it was verified at dump time.
2856 return true;
2857 }
2858 if (major_version() < 50 /*JAVA_6_VERSION*/) {
2859 return false;
2860 }
2861 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
2862 return false;
2863 }
2864 Array<InstanceKlass*>* interfaces = local_interfaces();
2865 int len = interfaces->length();
2866 for (int i = 0; i < len; i++) {
2867 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2868 return false;
2869 }
2870 }
2871 return true;
2872 }
2873
2874 #endif // INCLUDE_CDS
2875
2876 #if INCLUDE_JVMTI
2877 static void clear_all_breakpoints(Method* m) {
2878 m->clear_all_breakpoints();
2879 }
2880 #endif
2881
2882 void InstanceKlass::unload_class(InstanceKlass* ik) {
2883
2884 if (ik->is_scratch_class()) {
2885 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2886 return;
2887 }
2888 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2889
2890 // Release dependencies.
2891 ik->dependencies().remove_all_dependents();
2892
2893 // notify the debugger
2894 if (JvmtiExport::should_post_class_unload()) {
2895 JvmtiExport::post_class_unload(ik);
2896 }
2897
2898 // notify ClassLoadingService of class unload
2899 ClassLoadingService::notify_class_unloaded(ik);
2900
2901 SystemDictionaryShared::handle_class_unloading(ik);
2902
2903 if (log_is_enabled(Info, class, unload)) {
2904 ResourceMark rm;
2905 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2906 }
2907
2908 Events::log_class_unloading(Thread::current(), ik);
2909
2910 #if INCLUDE_JFR
2911 assert(ik != nullptr, "invariant");
2912 EventClassUnload event;
2913 event.set_unloadedClass(ik);
2914 event.set_definingClassLoader(ik->class_loader_data());
2915 event.commit();
2916 #endif
2917 }
2918
2919 static void method_release_C_heap_structures(Method* m) {
2920 m->release_C_heap_structures();
2921 }
2922
2923 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2924 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2925 // Clean up C heap
2926 Klass::release_C_heap_structures();
2927
2928 // Deallocate and call destructors for MDO mutexes
2929 if (release_sub_metadata) {
2930 methods_do(method_release_C_heap_structures);
2931 }
2932
2933 // Deallocate oop map cache
2934 if (_oop_map_cache != nullptr) {
2935 delete _oop_map_cache;
2936 _oop_map_cache = nullptr;
2937 }
2938
2939 // Deallocate JNI identifiers for jfieldIDs
2940 JNIid::deallocate(jni_ids());
2941 set_jni_ids(nullptr);
2942
2943 jmethodID* jmeths = _methods_jmethod_ids;
2944 if (jmeths != nullptr) {
2945 release_set_methods_jmethod_ids(nullptr);
2946 FreeHeap(jmeths);
2947 }
2948
2949 assert(_dep_context == nullptr,
2950 "dependencies should already be cleaned");
2951
2952 #if INCLUDE_JVMTI
2953 // Deallocate breakpoint records
2954 if (breakpoints() != nullptr) {
2955 methods_do(clear_all_breakpoints);
2956 assert(breakpoints() == nullptr, "should have cleared breakpoints");
2957 }
2958
2959 // deallocate the cached class file
2960 if (_cached_class_file != nullptr) {
2961 os::free(_cached_class_file);
2962 _cached_class_file = nullptr;
2963 }
2964 #endif
2965
2966 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2967
2968 if (release_sub_metadata) {
2969 constants()->release_C_heap_structures();
2970 }
2971 }
2972
2973 // The constant pool is on stack if any of the methods are executing or
2974 // referenced by handles.
2975 bool InstanceKlass::on_stack() const {
2976 return _constants->on_stack();
2977 }
2978
2979 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
2980 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
2981 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2982
2983 // minor and major version numbers of class file
2984 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
2985 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2986 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
2987 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2988
2989 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
2990 for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2991 if (ik->constants()->version() == version) {
2992 return ik;
2993 }
2994 }
2995 return nullptr;
2996 }
2997
2998 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2999 if (array == nullptr) {
3000 _source_debug_extension = nullptr;
3001 } else {
3002 // Adding one to the attribute length in order to store a null terminator
3003 // character could cause an overflow because the attribute length is
3004 // already coded with an u4 in the classfile, but in practice, it's
3005 // unlikely to happen.
3006 assert((length+1) > length, "Overflow checking");
3007 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3008 for (int i = 0; i < length; i++) {
3009 sde[i] = array[i];
3010 }
3011 sde[length] = '\0';
3012 _source_debug_extension = sde;
3013 }
3014 }
3015
3016 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3017 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3018 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3019
3020 const char* InstanceKlass::signature_name() const {
3021
3022 // Get the internal name as a c string
3023 const char* src = (const char*) (name()->as_C_string());
3024 const int src_length = (int)strlen(src);
3025
3026 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3027
3028 // Add L as type indicator
3029 int dest_index = 0;
3030 dest[dest_index++] = JVM_SIGNATURE_CLASS;
3031
3032 // Add the actual class name
3033 for (int src_index = 0; src_index < src_length; ) {
3034 dest[dest_index++] = src[src_index++];
3035 }
3036
3037 if (is_hidden()) { // Replace the last '+' with a '.'.
3038 for (int index = (int)src_length; index > 0; index--) {
3039 if (dest[index] == '+') {
3040 dest[index] = JVM_SIGNATURE_DOT;
3041 break;
3042 }
3043 }
3044 }
3045
3046 // Add the semicolon and the null
3047 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3048 dest[dest_index] = '\0';
3049 return dest;
3050 }
3051
3052 ModuleEntry* InstanceKlass::module() const {
3053 if (is_hidden() &&
3054 in_unnamed_package() &&
3055 class_loader_data()->has_class_mirror_holder()) {
3056 // For a non-strong hidden class defined to an unnamed package,
3057 // its (class held) CLD will not have an unnamed module created for it.
3058 // Two choices to find the correct ModuleEntry:
3059 // 1. If hidden class is within a nest, use nest host's module
3060 // 2. Find the unnamed module off from the class loader
3061 // For now option #2 is used since a nest host is not set until
3062 // after the instance class is created in jvm_lookup_define_class().
3063 if (class_loader_data()->is_boot_class_loader_data()) {
3064 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3065 } else {
3066 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3067 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3068 return java_lang_Module::module_entry(module);
3069 }
3070 }
3071
3072 // Class is in a named package
3073 if (!in_unnamed_package()) {
3074 return _package_entry->module();
3075 }
3076
3077 // Class is in an unnamed package, return its loader's unnamed module
3078 return class_loader_data()->unnamed_module();
3079 }
3080
3081 bool InstanceKlass::in_javabase_module() const {
3082 return module()->name() == vmSymbols::java_base();
3083 }
3084
3085 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3086
3087 // ensure java/ packages only loaded by boot or platform builtin loaders
3088 // not needed for shared class since CDS does not archive prohibited classes.
3089 if (!is_shared()) {
3090 check_prohibited_package(name(), loader_data, CHECK);
3091 }
3092
3093 if (is_shared() && _package_entry != nullptr) {
3094 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3095 // we can use the saved package
3096 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3097 return;
3098 } else {
3099 _package_entry = nullptr;
3100 }
3101 }
3102
3103 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3104 // it returns, so we need to decrement it when the current function exits.
3105 TempNewSymbol from_class_name =
3106 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3107
3108 Symbol* pkg_name;
3109 if (pkg_entry != nullptr) {
3110 pkg_name = pkg_entry->name();
3111 } else {
3112 pkg_name = from_class_name;
3113 }
3114
3115 if (pkg_name != nullptr && loader_data != nullptr) {
3116
3117 // Find in class loader's package entry table.
3118 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3119
3120 // If the package name is not found in the loader's package
3121 // entry table, it is an indication that the package has not
3122 // been defined. Consider it defined within the unnamed module.
3123 if (_package_entry == nullptr) {
3124
3125 if (!ModuleEntryTable::javabase_defined()) {
3126 // Before java.base is defined during bootstrapping, define all packages in
3127 // the java.base module. If a non-java.base package is erroneously placed
3128 // in the java.base module it will be caught later when java.base
3129 // is defined by ModuleEntryTable::verify_javabase_packages check.
3130 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3131 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3132 } else {
3133 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3134 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3135 }
3136
3137 // A package should have been successfully created
3138 DEBUG_ONLY(ResourceMark rm(THREAD));
3139 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3140 name()->as_C_string(), loader_data->loader_name_and_id());
3141 }
3142
3143 if (log_is_enabled(Debug, module)) {
3144 ResourceMark rm(THREAD);
3145 ModuleEntry* m = _package_entry->module();
3146 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3147 external_name(),
3148 pkg_name->as_C_string(),
3149 loader_data->loader_name_and_id(),
3150 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3151 }
3152 } else {
3153 ResourceMark rm(THREAD);
3154 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3155 external_name(),
3156 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3157 UNNAMED_MODULE);
3158 }
3159 }
3160
3161 // Function set_classpath_index ensures that for a non-null _package_entry
3162 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3163 // It then sets the classpath_index in the package entry record.
3164 //
3165 // The classpath_index field is used to find the entry on the boot loader class
3166 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3167 // in an unnamed module. It is also used to indicate (for all packages whose
3168 // classes are loaded by the boot loader) that at least one of the package's
3169 // classes has been loaded.
3170 void InstanceKlass::set_classpath_index(s2 path_index) {
3171 if (_package_entry != nullptr) {
3172 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3173 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3174 assert(path_index != -1, "Unexpected classpath_index");
3175 _package_entry->set_classpath_index(path_index);
3176 }
3177 }
3178
3179 // different versions of is_same_class_package
3180
3181 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3182 oop classloader1 = this->class_loader();
3183 PackageEntry* classpkg1 = this->package();
3184 if (class2->is_objArray_klass()) {
3185 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3186 }
3187
3188 oop classloader2;
3189 PackageEntry* classpkg2;
3190 if (class2->is_instance_klass()) {
3191 classloader2 = class2->class_loader();
3192 classpkg2 = class2->package();
3193 } else {
3194 assert(class2->is_typeArray_klass(), "should be type array");
3195 classloader2 = nullptr;
3196 classpkg2 = nullptr;
3197 }
3198
3199 // Same package is determined by comparing class loader
3200 // and package entries. Both must be the same. This rule
3201 // applies even to classes that are defined in the unnamed
3202 // package, they still must have the same class loader.
3203 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3204 return true;
3205 }
3206
3207 return false;
3208 }
3209
3210 // return true if this class and other_class are in the same package. Classloader
3211 // and classname information is enough to determine a class's package
3212 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3213 const Symbol* other_class_name) const {
3214 if (class_loader() != other_class_loader) {
3215 return false;
3216 }
3217 if (name()->fast_compare(other_class_name) == 0) {
3218 return true;
3219 }
3220
3221 {
3222 ResourceMark rm;
3223
3224 bool bad_class_name = false;
3225 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3226 if (bad_class_name) {
3227 return false;
3228 }
3229 // Check that package_from_class_name() returns null, not "", if there is no package.
3230 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3231
3232 const Symbol* const this_package_name =
3233 this->package() != nullptr ? this->package()->name() : nullptr;
3234
3235 if (this_package_name == nullptr || other_pkg == nullptr) {
3236 // One of the two doesn't have a package. Only return true if the other
3237 // one also doesn't have a package.
3238 return this_package_name == other_pkg;
3239 }
3240
3241 // Check if package is identical
3242 return this_package_name->fast_compare(other_pkg) == 0;
3243 }
3244 }
3245
3246 static bool is_prohibited_package_slow(Symbol* class_name) {
3247 // Caller has ResourceMark
3248 int length;
3249 jchar* unicode = class_name->as_unicode(length);
3250 return (length >= 5 &&
3251 unicode[0] == 'j' &&
3252 unicode[1] == 'a' &&
3253 unicode[2] == 'v' &&
3254 unicode[3] == 'a' &&
3255 unicode[4] == '/');
3256 }
3257
3258 // Only boot and platform class loaders can define classes in "java/" packages.
3259 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3260 ClassLoaderData* loader_data,
3261 TRAPS) {
3262 if (!loader_data->is_boot_class_loader_data() &&
3263 !loader_data->is_platform_class_loader_data() &&
3264 class_name != nullptr && class_name->utf8_length() >= 5) {
3265 ResourceMark rm(THREAD);
3266 bool prohibited;
3267 const u1* base = class_name->base();
3268 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3269 prohibited = is_prohibited_package_slow(class_name);
3270 } else {
3271 char* name = class_name->as_C_string();
3272 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3273 }
3274 if (prohibited) {
3275 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3276 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3277 char* name = pkg_name->as_C_string();
3278 const char* class_loader_name = loader_data->loader_name_and_id();
3279 StringUtils::replace_no_expand(name, "/", ".");
3280 const char* msg_text1 = "Class loader (instance of): ";
3281 const char* msg_text2 = " tried to load prohibited package name: ";
3282 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3283 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3284 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3285 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3286 }
3287 }
3288 return;
3289 }
3290
3291 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3292 constantPoolHandle i_cp(THREAD, constants());
3293 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3294 int ioff = iter.inner_class_info_index();
3295 if (ioff != 0) {
3296 // Check to see if the name matches the class we're looking for
3297 // before attempting to find the class.
3298 if (i_cp->klass_name_at_matches(this, ioff)) {
3299 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3300 if (this == inner_klass) {
3301 *ooff = iter.outer_class_info_index();
3302 *noff = iter.inner_name_index();
3303 return true;
3304 }
3305 }
3306 }
3307 }
3308 return false;
3309 }
3310
3311 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3312 InstanceKlass* outer_klass = nullptr;
3313 *inner_is_member = false;
3314 int ooff = 0, noff = 0;
3315 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3316 if (has_inner_classes_attr) {
3317 constantPoolHandle i_cp(THREAD, constants());
3318 if (ooff != 0) {
3319 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3320 if (!ok->is_instance_klass()) {
3321 // If the outer class is not an instance klass then it cannot have
3322 // declared any inner classes.
3323 ResourceMark rm(THREAD);
3324 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3325 Exceptions::fthrow(
3326 THREAD_AND_LOCATION,
3327 vmSymbols::java_lang_IncompatibleClassChangeError(),
3328 "%s and %s disagree on InnerClasses attribute",
3329 ok->external_name(),
3330 external_name());
3331 return nullptr;
3332 }
3333 outer_klass = InstanceKlass::cast(ok);
3334 *inner_is_member = true;
3335 }
3336 if (nullptr == outer_klass) {
3337 // It may be a local class; try for that.
3338 int encl_method_class_idx = enclosing_method_class_index();
3339 if (encl_method_class_idx != 0) {
3340 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3341 outer_klass = InstanceKlass::cast(ok);
3342 *inner_is_member = false;
3343 }
3344 }
3345 }
3346
3347 // If no inner class attribute found for this class.
3348 if (nullptr == outer_klass) return nullptr;
3349
3350 // Throws an exception if outer klass has not declared k as an inner klass
3351 // We need evidence that each klass knows about the other, or else
3352 // the system could allow a spoof of an inner class to gain access rights.
3353 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3354 return outer_klass;
3355 }
3356
3357 u2 InstanceKlass::compute_modifier_flags() const {
3358 u2 access = access_flags().as_unsigned_short();
3359
3360 // But check if it happens to be member class.
3361 InnerClassesIterator iter(this);
3362 for (; !iter.done(); iter.next()) {
3363 int ioff = iter.inner_class_info_index();
3364 // Inner class attribute can be zero, skip it.
3365 // Strange but true: JVM spec. allows null inner class refs.
3366 if (ioff == 0) continue;
3367
3368 // only look at classes that are already loaded
3369 // since we are looking for the flags for our self.
3370 Symbol* inner_name = constants()->klass_name_at(ioff);
3371 if (name() == inner_name) {
3372 // This is really a member class.
3373 access = iter.inner_access_flags();
3374 break;
3375 }
3376 }
3377 // Remember to strip ACC_SUPER bit
3378 return (access & (~JVM_ACC_SUPER));
3379 }
3380
3381 jint InstanceKlass::jvmti_class_status() const {
3382 jint result = 0;
3383
3384 if (is_linked()) {
3385 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3386 }
3387
3388 if (is_initialized()) {
3389 assert(is_linked(), "Class status is not consistent");
3390 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3391 }
3392 if (is_in_error_state()) {
3393 result |= JVMTI_CLASS_STATUS_ERROR;
3394 }
3395 return result;
3396 }
3397
3398 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3399 bool implements_interface; // initialized by method_at_itable_or_null
3400 Method* m = method_at_itable_or_null(holder, index,
3401 implements_interface); // out parameter
3402 if (m != nullptr) {
3403 assert(implements_interface, "sanity");
3404 return m;
3405 } else if (implements_interface) {
3406 // Throw AbstractMethodError since corresponding itable slot is empty.
3407 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3408 } else {
3409 // If the interface isn't implemented by the receiver class,
3410 // the VM should throw IncompatibleClassChangeError.
3411 ResourceMark rm(THREAD);
3412 stringStream ss;
3413 bool same_module = (module() == holder->module());
3414 ss.print("Receiver class %s does not implement "
3415 "the interface %s defining the method to be called "
3416 "(%s%s%s)",
3417 external_name(), holder->external_name(),
3418 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3419 (same_module) ? "" : "; ",
3420 (same_module) ? "" : holder->class_in_module_of_loader());
3421 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3422 }
3423 }
3424
3425 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3426 klassItable itable(this);
3427 for (int i = 0; i < itable.size_offset_table(); i++) {
3428 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3429 if (offset_entry->interface_klass() == holder) {
3430 implements_interface = true;
3431 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3432 Method* m = ime[index].method();
3433 return m;
3434 }
3435 }
3436 implements_interface = false;
3437 return nullptr; // offset entry not found
3438 }
3439
3440 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3441 assert(is_linked(), "required");
3442 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3443 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3444
3445 int vtable_index = Method::invalid_vtable_index;
3446 Symbol* name = intf_method->name();
3447 Symbol* signature = intf_method->signature();
3448
3449 // First check in default method array
3450 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3451 int index = find_method_index(default_methods(),
3452 name, signature,
3453 Klass::OverpassLookupMode::find,
3454 Klass::StaticLookupMode::find,
3455 Klass::PrivateLookupMode::find);
3456 if (index >= 0) {
3457 vtable_index = default_vtable_indices()->at(index);
3458 }
3459 }
3460 if (vtable_index == Method::invalid_vtable_index) {
3461 // get vtable_index for miranda methods
3462 klassVtable vt = vtable();
3463 vtable_index = vt.index_of_miranda(name, signature);
3464 }
3465 return vtable_index;
3466 }
3467
3468 #if INCLUDE_JVMTI
3469 // update default_methods for redefineclasses for methods that are
3470 // not yet in the vtable due to concurrent subclass define and superinterface
3471 // redefinition
3472 // Note: those in the vtable, should have been updated via adjust_method_entries
3473 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3474 // search the default_methods for uses of either obsolete or EMCP methods
3475 if (default_methods() != nullptr) {
3476 for (int index = 0; index < default_methods()->length(); index ++) {
3477 Method* old_method = default_methods()->at(index);
3478 if (old_method == nullptr || !old_method->is_old()) {
3479 continue; // skip uninteresting entries
3480 }
3481 assert(!old_method->is_deleted(), "default methods may not be deleted");
3482 Method* new_method = old_method->get_new_method();
3483 default_methods()->at_put(index, new_method);
3484
3485 if (log_is_enabled(Info, redefine, class, update)) {
3486 ResourceMark rm;
3487 if (!(*trace_name_printed)) {
3488 log_info(redefine, class, update)
3489 ("adjust: klassname=%s default methods from name=%s",
3490 external_name(), old_method->method_holder()->external_name());
3491 *trace_name_printed = true;
3492 }
3493 log_debug(redefine, class, update, vtables)
3494 ("default method update: %s(%s) ",
3495 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3496 }
3497 }
3498 }
3499 }
3500 #endif // INCLUDE_JVMTI
3501
3502 // On-stack replacement stuff
3503 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3504 assert_lock_strong(NMethodState_lock);
3505 #ifndef PRODUCT
3506 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3507 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3508 "redundant OSR recompilation detected. memory leak in CodeCache!");
3509 #endif
3510 // only one compilation can be active
3511 assert(n->is_osr_method(), "wrong kind of nmethod");
3512 n->set_osr_link(osr_nmethods_head());
3513 set_osr_nmethods_head(n);
3514 // Raise the highest osr level if necessary
3515 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3516
3517 // Get rid of the osr methods for the same bci that have lower levels.
3518 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3519 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3520 if (inv != nullptr && inv->is_in_use()) {
3521 inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3522 }
3523 }
3524 }
3525
3526 // Remove osr nmethod from the list. Return true if found and removed.
3527 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3528 // This is a short non-blocking critical region, so the no safepoint check is ok.
3529 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3530 assert(n->is_osr_method(), "wrong kind of nmethod");
3531 nmethod* last = nullptr;
3532 nmethod* cur = osr_nmethods_head();
3533 int max_level = CompLevel_none; // Find the max comp level excluding n
3534 Method* m = n->method();
3535 // Search for match
3536 bool found = false;
3537 while(cur != nullptr && cur != n) {
3538 if (m == cur->method()) {
3539 // Find max level before n
3540 max_level = MAX2(max_level, cur->comp_level());
3541 }
3542 last = cur;
3543 cur = cur->osr_link();
3544 }
3545 nmethod* next = nullptr;
3546 if (cur == n) {
3547 found = true;
3548 next = cur->osr_link();
3549 if (last == nullptr) {
3550 // Remove first element
3551 set_osr_nmethods_head(next);
3552 } else {
3553 last->set_osr_link(next);
3554 }
3555 }
3556 n->set_osr_link(nullptr);
3557 cur = next;
3558 while (cur != nullptr) {
3559 // Find max level after n
3560 if (m == cur->method()) {
3561 max_level = MAX2(max_level, cur->comp_level());
3562 }
3563 cur = cur->osr_link();
3564 }
3565 m->set_highest_osr_comp_level(max_level);
3566 return found;
3567 }
3568
3569 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3570 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3571 nmethod* osr = osr_nmethods_head();
3572 int found = 0;
3573 while (osr != nullptr) {
3574 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3575 if (osr->method() == m) {
3576 deopt_scope->mark(osr);
3577 found++;
3578 }
3579 osr = osr->osr_link();
3580 }
3581 return found;
3582 }
3583
3584 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3585 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3586 nmethod* osr = osr_nmethods_head();
3587 nmethod* best = nullptr;
3588 while (osr != nullptr) {
3589 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3590 // There can be a time when a c1 osr method exists but we are waiting
3591 // for a c2 version. When c2 completes its osr nmethod we will trash
3592 // the c1 version and only be able to find the c2 version. However
3593 // while we overflow in the c1 code at back branches we don't want to
3594 // try and switch to the same code as we are already running
3595
3596 if (osr->method() == m &&
3597 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3598 if (match_level) {
3599 if (osr->comp_level() == comp_level) {
3600 // Found a match - return it.
3601 return osr;
3602 }
3603 } else {
3604 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3605 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3606 // Found the best possible - return it.
3607 return osr;
3608 }
3609 best = osr;
3610 }
3611 }
3612 }
3613 osr = osr->osr_link();
3614 }
3615
3616 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3617 if (best != nullptr && best->comp_level() >= comp_level) {
3618 return best;
3619 }
3620 return nullptr;
3621 }
3622
3623 // -----------------------------------------------------------------------------------------------------
3624 // Printing
3625
3626 #define BULLET " - "
3627
3628 static const char* state_names[] = {
3629 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3630 };
3631
3632 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3633 for (int i = 0; i < len; i++) {
3634 intptr_t e = start[i];
3635 st->print("%d : " INTPTR_FORMAT, i, e);
3636 if (MetaspaceObj::is_valid((Metadata*)e)) {
3637 st->print(" ");
3638 ((Metadata*)e)->print_value_on(st);
3639 }
3640 st->cr();
3641 }
3642 }
3643
3644 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3645 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3646 }
3647
3648 const char* InstanceKlass::init_state_name() const {
3649 return state_names[init_state()];
3650 }
3651
3652 void InstanceKlass::print_on(outputStream* st) const {
3653 assert(is_klass(), "must be klass");
3654 Klass::print_on(st);
3655
3656 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3657 st->print(BULLET"klass size: %d", size()); st->cr();
3658 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3659 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3660 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3661 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3662 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3663 st->print(BULLET"sub: ");
3664 Klass* sub = subklass();
3665 int n;
3666 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3667 if (n < MaxSubklassPrintSize) {
3668 sub->print_value_on(st);
3669 st->print(" ");
3670 }
3671 }
3672 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3673 st->cr();
3674
3675 if (is_interface()) {
3676 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3677 if (nof_implementors() == 1) {
3678 st->print_cr(BULLET"implementor: ");
3679 st->print(" ");
3680 implementor()->print_value_on(st);
3681 st->cr();
3682 }
3683 }
3684
3685 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3686 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3687 if (Verbose || WizardMode) {
3688 Array<Method*>* method_array = methods();
3689 for (int i = 0; i < method_array->length(); i++) {
3690 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3691 }
3692 }
3693 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3694 if (default_methods() != nullptr) {
3695 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3696 if (Verbose) {
3697 Array<Method*>* method_array = default_methods();
3698 for (int i = 0; i < method_array->length(); i++) {
3699 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3700 }
3701 }
3702 }
3703 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
3704 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3705 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3706
3707 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3708
3709 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
3710 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3711
3712 if (secondary_supers() != nullptr) {
3713 if (Verbose) {
3714 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3715 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3716 for (int i = 0; i < _secondary_supers->length(); i++) {
3717 ResourceMark rm; // for external_name()
3718 Klass* secondary_super = _secondary_supers->at(i);
3719 st->print(BULLET"%2d:", i);
3720 if (is_hashed) {
3721 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3722 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3723 st->print(" dist:%02d:", distance);
3724 }
3725 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3726 }
3727 }
3728 }
3729 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3730
3731 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
3732 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
3733 if (source_debug_extension() != nullptr) {
3734 st->print(BULLET"source debug extension: ");
3735 st->print("%s", source_debug_extension());
3736 st->cr();
3737 }
3738 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
3739 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
3740 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
3741 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
3742 {
3743 bool have_pv = false;
3744 // previous versions are linked together through the InstanceKlass
3745 for (InstanceKlass* pv_node = previous_versions();
3746 pv_node != nullptr;
3747 pv_node = pv_node->previous_versions()) {
3748 if (!have_pv)
3749 st->print(BULLET"previous version: ");
3750 have_pv = true;
3751 pv_node->constants()->print_value_on(st);
3752 }
3753 if (have_pv) st->cr();
3754 }
3755
3756 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3757 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3758 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3759 print_on_maybe_null(st, BULLET"record components: ", record_components());
3760 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
3761 if (java_mirror() != nullptr) {
3762 st->print(BULLET"java mirror: ");
3763 java_mirror()->print_value_on(st);
3764 st->cr();
3765 } else {
3766 st->print_cr(BULLET"java mirror: null");
3767 }
3768 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3769 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3770 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3771 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3772 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3773
3774 FieldPrinter print_static_field(st);
3775 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3776 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3777 FieldPrinter print_nonstatic_field(st);
3778 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3779 ik->print_nonstatic_fields(&print_nonstatic_field);
3780
3781 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3782 OopMapBlock* map = start_of_nonstatic_oop_maps();
3783 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3784 while (map < end_map) {
3785 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3786 map++;
3787 }
3788 st->cr();
3789
3790 if (fieldinfo_search_table() != nullptr) {
3791 st->print_cr(BULLET"---- field info search table:");
3792 FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
3793 }
3794 }
3795
3796 void InstanceKlass::print_value_on(outputStream* st) const {
3797 assert(is_klass(), "must be klass");
3798 if (Verbose || WizardMode) access_flags().print_on(st);
3799 name()->print_value_on(st);
3800 }
3801
3802 void FieldPrinter::do_field(fieldDescriptor* fd) {
3803 _st->print(BULLET);
3804 if (_obj == nullptr) {
3805 fd->print_on(_st);
3806 _st->cr();
3807 } else {
3808 fd->print_on_for(_st, _obj);
3809 _st->cr();
3810 }
3811 }
3812
3813
3814 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3815 Klass::oop_print_on(obj, st);
3816
3817 if (this == vmClasses::String_klass()) {
3818 typeArrayOop value = java_lang_String::value(obj);
3819 juint length = java_lang_String::length(obj);
3820 if (value != nullptr &&
3821 value->is_typeArray() &&
3822 length <= (juint) value->length()) {
3823 st->print(BULLET"string: ");
3824 java_lang_String::print(obj, st);
3825 st->cr();
3826 }
3827 }
3828
3829 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3830 FieldPrinter print_field(st, obj);
3831 print_nonstatic_fields(&print_field);
3832
3833 if (this == vmClasses::Class_klass()) {
3834 st->print(BULLET"signature: ");
3835 java_lang_Class::print_signature(obj, st);
3836 st->cr();
3837 Klass* real_klass = java_lang_Class::as_Klass(obj);
3838 if (real_klass != nullptr && real_klass->is_instance_klass()) {
3839 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3840 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3841 }
3842 } else if (this == vmClasses::MethodType_klass()) {
3843 st->print(BULLET"signature: ");
3844 java_lang_invoke_MethodType::print_signature(obj, st);
3845 st->cr();
3846 }
3847 }
3848
3849 #ifndef PRODUCT
3850
3851 bool InstanceKlass::verify_itable_index(int i) {
3852 int method_count = klassItable::method_count_for_interface(this);
3853 assert(i >= 0 && i < method_count, "index out of bounds");
3854 return true;
3855 }
3856
3857 #endif //PRODUCT
3858
3859 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3860 st->print("a ");
3861 name()->print_value_on(st);
3862 obj->print_address_on(st);
3863 if (this == vmClasses::String_klass()
3864 && java_lang_String::value(obj) != nullptr) {
3865 ResourceMark rm;
3866 int len = java_lang_String::length(obj);
3867 int plen = (len < 24 ? len : 12);
3868 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3869 st->print(" = \"%s\"", str);
3870 if (len > plen)
3871 st->print("...[%d]", len);
3872 } else if (this == vmClasses::Class_klass()) {
3873 Klass* k = java_lang_Class::as_Klass(obj);
3874 st->print(" = ");
3875 if (k != nullptr) {
3876 k->print_value_on(st);
3877 } else {
3878 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3879 st->print("%s", tname ? tname : "type?");
3880 }
3881 } else if (this == vmClasses::MethodType_klass()) {
3882 st->print(" = ");
3883 java_lang_invoke_MethodType::print_signature(obj, st);
3884 } else if (java_lang_boxing_object::is_instance(obj)) {
3885 st->print(" = ");
3886 java_lang_boxing_object::print(obj, st);
3887 } else if (this == vmClasses::LambdaForm_klass()) {
3888 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3889 if (vmentry != nullptr) {
3890 st->print(" => ");
3891 vmentry->print_value_on(st);
3892 }
3893 } else if (this == vmClasses::MemberName_klass()) {
3894 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3895 if (vmtarget != nullptr) {
3896 st->print(" = ");
3897 vmtarget->print_value_on(st);
3898 } else {
3899 oop clazz = java_lang_invoke_MemberName::clazz(obj);
3900 oop name = java_lang_invoke_MemberName::name(obj);
3901 if (clazz != nullptr) {
3902 clazz->print_value_on(st);
3903 } else {
3904 st->print("null");
3905 }
3906 st->print(".");
3907 if (name != nullptr) {
3908 name->print_value_on(st);
3909 } else {
3910 st->print("null");
3911 }
3912 }
3913 }
3914 }
3915
3916 const char* InstanceKlass::internal_name() const {
3917 return external_name();
3918 }
3919
3920 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3921 const ModuleEntry* module_entry,
3922 const ClassFileStream* cfs) const {
3923
3924 if (ClassListWriter::is_enabled()) {
3925 ClassListWriter::write(this, cfs);
3926 }
3927
3928 print_class_load_helper(loader_data, module_entry, cfs);
3929 print_class_load_cause_logging();
3930 }
3931
3932 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3933 const ModuleEntry* module_entry,
3934 const ClassFileStream* cfs) const {
3935
3936 if (!log_is_enabled(Info, class, load)) {
3937 return;
3938 }
3939
3940 ResourceMark rm;
3941 LogMessage(class, load) msg;
3942 stringStream info_stream;
3943
3944 // Name and class hierarchy info
3945 info_stream.print("%s", external_name());
3946
3947 // Source
3948 if (cfs != nullptr) {
3949 if (cfs->source() != nullptr) {
3950 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3951 if (module_name != nullptr) {
3952 // When the boot loader created the stream, it didn't know the module name
3953 // yet. Let's format it now.
3954 if (cfs->from_boot_loader_modules_image()) {
3955 info_stream.print(" source: jrt:/%s", module_name);
3956 } else {
3957 info_stream.print(" source: %s", cfs->source());
3958 }
3959 } else {
3960 info_stream.print(" source: %s", cfs->source());
3961 }
3962 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3963 Thread* current = Thread::current();
3964 Klass* caller = current->is_Java_thread() ?
3965 JavaThread::cast(current)->security_get_caller_class(1):
3966 nullptr;
3967 // caller can be null, for example, during a JVMTI VM_Init hook
3968 if (caller != nullptr) {
3969 info_stream.print(" source: instance of %s", caller->external_name());
3970 } else {
3971 // source is unknown
3972 }
3973 } else {
3974 oop class_loader = loader_data->class_loader();
3975 info_stream.print(" source: %s", class_loader->klass()->external_name());
3976 }
3977 } else {
3978 assert(this->is_shared(), "must be");
3979 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3980 info_stream.print(" source: shared objects file (top)");
3981 } else {
3982 info_stream.print(" source: shared objects file");
3983 }
3984 }
3985
3986 msg.info("%s", info_stream.as_string());
3987
3988 if (log_is_enabled(Debug, class, load)) {
3989 stringStream debug_stream;
3990
3991 // Class hierarchy info
3992 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3993 p2i(this), p2i(superklass()));
3994
3995 // Interfaces
3996 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3997 debug_stream.print(" interfaces:");
3998 int length = local_interfaces()->length();
3999 for (int i = 0; i < length; i++) {
4000 debug_stream.print(" " PTR_FORMAT,
4001 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
4002 }
4003 }
4004
4005 // Class loader
4006 debug_stream.print(" loader: [");
4007 loader_data->print_value_on(&debug_stream);
4008 debug_stream.print("]");
4009
4010 // Classfile checksum
4011 if (cfs) {
4012 debug_stream.print(" bytes: %d checksum: %08x",
4013 cfs->length(),
4014 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4015 cfs->length()));
4016 }
4017
4018 msg.debug("%s", debug_stream.as_string());
4019 }
4020 }
4021
4022 void InstanceKlass::print_class_load_cause_logging() const {
4023 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4024 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4025 JavaThread* current = JavaThread::current();
4026 ResourceMark rm(current);
4027 const char* name = external_name();
4028
4029 if (LogClassLoadingCauseFor == nullptr ||
4030 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4031 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4032 return;
4033 }
4034
4035 // Log Java stack first
4036 {
4037 LogMessage(class, load, cause) msg;
4038 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4039
4040 info_stream.print_cr("Java stack when loading %s:", name);
4041 current->print_stack_on(&info_stream);
4042 }
4043
4044 // Log native stack second
4045 if (log_cause_native) {
4046 // Log to string first so that lines can be indented
4047 stringStream stack_stream;
4048 char buf[O_BUFLEN];
4049 address lastpc = nullptr;
4050 NativeStackPrinter nsp(current);
4051 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4052 true /* print_source_info */, -1 /* max stack */);
4053
4054 LogMessage(class, load, cause, native) msg;
4055 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4056 info_stream.print_cr("Native stack when loading %s:", name);
4057
4058 // Print each native stack line to the log
4059 int size = (int) stack_stream.size();
4060 char* stack = stack_stream.as_string();
4061 char* stack_end = stack + size;
4062 char* line_start = stack;
4063 for (char* p = stack; p < stack_end; p++) {
4064 if (*p == '\n') {
4065 *p = '\0';
4066 info_stream.print_cr("\t%s", line_start);
4067 line_start = p + 1;
4068 }
4069 }
4070 if (line_start < stack_end) {
4071 info_stream.print_cr("\t%s", line_start);
4072 }
4073 }
4074 }
4075 }
4076
4077 // Verification
4078
4079 class VerifyFieldClosure: public BasicOopIterateClosure {
4080 protected:
4081 template <class T> void do_oop_work(T* p) {
4082 oop obj = RawAccess<>::oop_load(p);
4083 if (!oopDesc::is_oop_or_null(obj)) {
4084 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4085 Universe::print_on(tty);
4086 guarantee(false, "boom");
4087 }
4088 }
4089 public:
4090 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4091 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4092 };
4093
4094 void InstanceKlass::verify_on(outputStream* st) {
4095 #ifndef PRODUCT
4096 // Avoid redundant verifies, this really should be in product.
4097 if (_verify_count == Universe::verify_count()) return;
4098 _verify_count = Universe::verify_count();
4099 #endif
4100
4101 // Verify Klass
4102 Klass::verify_on(st);
4103
4104 // Verify that klass is present in ClassLoaderData
4105 guarantee(class_loader_data()->contains_klass(this),
4106 "this class isn't found in class loader data");
4107
4108 // Verify vtables
4109 if (is_linked()) {
4110 // $$$ This used to be done only for m/s collections. Doing it
4111 // always seemed a valid generalization. (DLD -- 6/00)
4112 vtable().verify(st);
4113 }
4114
4115 // Verify first subklass
4116 if (subklass() != nullptr) {
4117 guarantee(subklass()->is_klass(), "should be klass");
4118 }
4119
4120 // Verify siblings
4121 Klass* super = this->super();
4122 Klass* sib = next_sibling();
4123 if (sib != nullptr) {
4124 if (sib == this) {
4125 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4126 }
4127
4128 guarantee(sib->is_klass(), "should be klass");
4129 guarantee(sib->super() == super, "siblings should have same superklass");
4130 }
4131
4132 // Verify local interfaces
4133 if (local_interfaces()) {
4134 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4135 for (int j = 0; j < local_interfaces->length(); j++) {
4136 InstanceKlass* e = local_interfaces->at(j);
4137 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4138 }
4139 }
4140
4141 // Verify transitive interfaces
4142 if (transitive_interfaces() != nullptr) {
4143 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4144 for (int j = 0; j < transitive_interfaces->length(); j++) {
4145 InstanceKlass* e = transitive_interfaces->at(j);
4146 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4147 }
4148 }
4149
4150 // Verify methods
4151 if (methods() != nullptr) {
4152 Array<Method*>* methods = this->methods();
4153 for (int j = 0; j < methods->length(); j++) {
4154 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4155 }
4156 for (int j = 0; j < methods->length() - 1; j++) {
4157 Method* m1 = methods->at(j);
4158 Method* m2 = methods->at(j + 1);
4159 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4160 }
4161 }
4162
4163 // Verify method ordering
4164 if (method_ordering() != nullptr) {
4165 Array<int>* method_ordering = this->method_ordering();
4166 int length = method_ordering->length();
4167 if (JvmtiExport::can_maintain_original_method_order() ||
4168 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4169 guarantee(length == methods()->length(), "invalid method ordering length");
4170 jlong sum = 0;
4171 for (int j = 0; j < length; j++) {
4172 int original_index = method_ordering->at(j);
4173 guarantee(original_index >= 0, "invalid method ordering index");
4174 guarantee(original_index < length, "invalid method ordering index");
4175 sum += original_index;
4176 }
4177 // Verify sum of indices 0,1,...,length-1
4178 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4179 } else {
4180 guarantee(length == 0, "invalid method ordering length");
4181 }
4182 }
4183
4184 // Verify default methods
4185 if (default_methods() != nullptr) {
4186 Array<Method*>* methods = this->default_methods();
4187 for (int j = 0; j < methods->length(); j++) {
4188 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4189 }
4190 for (int j = 0; j < methods->length() - 1; j++) {
4191 Method* m1 = methods->at(j);
4192 Method* m2 = methods->at(j + 1);
4193 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4194 }
4195 }
4196
4197 // Verify JNI static field identifiers
4198 if (jni_ids() != nullptr) {
4199 jni_ids()->verify(this);
4200 }
4201
4202 // Verify other fields
4203 if (constants() != nullptr) {
4204 guarantee(constants()->is_constantPool(), "should be constant pool");
4205 }
4206 }
4207
4208 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4209 Klass::oop_verify_on(obj, st);
4210 VerifyFieldClosure blk;
4211 obj->oop_iterate(&blk);
4212 }
4213
4214
4215 // JNIid class for jfieldIDs only
4216 // Note to reviewers:
4217 // These JNI functions are just moved over to column 1 and not changed
4218 // in the compressed oops workspace.
4219 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4220 _holder = holder;
4221 _offset = offset;
4222 _next = next;
4223 DEBUG_ONLY(_is_static_field_id = false;)
4224 }
4225
4226
4227 JNIid* JNIid::find(int offset) {
4228 JNIid* current = this;
4229 while (current != nullptr) {
4230 if (current->offset() == offset) return current;
4231 current = current->next();
4232 }
4233 return nullptr;
4234 }
4235
4236 void JNIid::deallocate(JNIid* current) {
4237 while (current != nullptr) {
4238 JNIid* next = current->next();
4239 delete current;
4240 current = next;
4241 }
4242 }
4243
4244
4245 void JNIid::verify(Klass* holder) {
4246 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4247 int end_field_offset;
4248 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4249
4250 JNIid* current = this;
4251 while (current != nullptr) {
4252 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4253 #ifdef ASSERT
4254 int o = current->offset();
4255 if (current->is_static_field_id()) {
4256 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4257 }
4258 #endif
4259 current = current->next();
4260 }
4261 }
4262
4263 void InstanceKlass::set_init_state(ClassState state) {
4264 #ifdef ASSERT
4265 bool good_state = is_shared() ? (_init_state <= state)
4266 : (_init_state < state);
4267 assert(good_state || state == allocated, "illegal state transition");
4268 #endif
4269 assert(_init_thread == nullptr, "should be cleared before state change");
4270 Atomic::release_store(&_init_state, state);
4271 }
4272
4273 #if INCLUDE_JVMTI
4274
4275 // RedefineClasses() support for previous versions
4276
4277 // Globally, there is at least one previous version of a class to walk
4278 // during class unloading, which is saved because old methods in the class
4279 // are still running. Otherwise the previous version list is cleaned up.
4280 bool InstanceKlass::_should_clean_previous_versions = false;
4281
4282 // Returns true if there are previous versions of a class for class
4283 // unloading only. Also resets the flag to false. purge_previous_version
4284 // will set the flag to true if there are any left, i.e., if there's any
4285 // work to do for next time. This is to avoid the expensive code cache
4286 // walk in CLDG::clean_deallocate_lists().
4287 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4288 bool ret = _should_clean_previous_versions;
4289 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4290 ret ? "true" : "false");
4291 _should_clean_previous_versions = false;
4292 return ret;
4293 }
4294
4295 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4296 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4297 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4298 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4299 Array<Method*>* method_refs = klass->methods();
4300 for (int k = 0; k < method_refs->length(); k++) {
4301 Method* method = method_refs->at(k);
4302 // Only need to clear obsolete methods.
4303 if (method != nullptr && method->is_obsolete()) {
4304 method->clear_jmethod_id();
4305 }
4306 }
4307 }
4308
4309 // Purge previous versions before adding new previous versions of the class and
4310 // during class unloading.
4311 void InstanceKlass::purge_previous_version_list() {
4312 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4313 assert(has_been_redefined(), "Should only be called for main class");
4314
4315 // Quick exit.
4316 if (previous_versions() == nullptr) {
4317 return;
4318 }
4319
4320 // This klass has previous versions so see what we can cleanup
4321 // while it is safe to do so.
4322
4323 int deleted_count = 0; // leave debugging breadcrumbs
4324 int live_count = 0;
4325 ClassLoaderData* loader_data = class_loader_data();
4326 assert(loader_data != nullptr, "should never be null");
4327
4328 ResourceMark rm;
4329 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4330
4331 // previous versions are linked together through the InstanceKlass
4332 InstanceKlass* pv_node = previous_versions();
4333 InstanceKlass* last = this;
4334 int version = 0;
4335
4336 // check the previous versions list
4337 for (; pv_node != nullptr; ) {
4338
4339 ConstantPool* pvcp = pv_node->constants();
4340 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4341
4342 if (!pvcp->on_stack()) {
4343 // If the constant pool isn't on stack, none of the methods
4344 // are executing. Unlink this previous_version.
4345 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4346 // so will be deallocated during the next phase of class unloading.
4347 log_trace(redefine, class, iklass, purge)
4348 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4349 // Unlink from previous version list.
4350 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4351 InstanceKlass* next = pv_node->previous_versions();
4352 clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4353 pv_node->link_previous_versions(nullptr); // point next to null
4354 last->link_previous_versions(next);
4355 // Delete this node directly. Nothing is referring to it and we don't
4356 // want it to increase the counter for metadata to delete in CLDG.
4357 MetadataFactory::free_metadata(loader_data, pv_node);
4358 pv_node = next;
4359 deleted_count++;
4360 version++;
4361 continue;
4362 } else {
4363 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4364 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4365 live_count++;
4366 if (pvcp->is_shared()) {
4367 // Shared previous versions can never be removed so no cleaning is needed.
4368 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4369 } else {
4370 // Previous version alive, set that clean is needed for next time.
4371 _should_clean_previous_versions = true;
4372 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4373 }
4374 }
4375
4376 // next previous version
4377 last = pv_node;
4378 pv_node = pv_node->previous_versions();
4379 version++;
4380 }
4381 log_trace(redefine, class, iklass, purge)
4382 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4383 }
4384
4385 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4386 int emcp_method_count) {
4387 int obsolete_method_count = old_methods->length() - emcp_method_count;
4388
4389 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4390 _previous_versions != nullptr) {
4391 // We have a mix of obsolete and EMCP methods so we have to
4392 // clear out any matching EMCP method entries the hard way.
4393 int local_count = 0;
4394 for (int i = 0; i < old_methods->length(); i++) {
4395 Method* old_method = old_methods->at(i);
4396 if (old_method->is_obsolete()) {
4397 // only obsolete methods are interesting
4398 Symbol* m_name = old_method->name();
4399 Symbol* m_signature = old_method->signature();
4400
4401 // previous versions are linked together through the InstanceKlass
4402 int j = 0;
4403 for (InstanceKlass* prev_version = _previous_versions;
4404 prev_version != nullptr;
4405 prev_version = prev_version->previous_versions(), j++) {
4406
4407 Array<Method*>* method_refs = prev_version->methods();
4408 for (int k = 0; k < method_refs->length(); k++) {
4409 Method* method = method_refs->at(k);
4410
4411 if (!method->is_obsolete() &&
4412 method->name() == m_name &&
4413 method->signature() == m_signature) {
4414 // The current RedefineClasses() call has made all EMCP
4415 // versions of this method obsolete so mark it as obsolete
4416 log_trace(redefine, class, iklass, add)
4417 ("%s(%s): flush obsolete method @%d in version @%d",
4418 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4419
4420 method->set_is_obsolete();
4421 break;
4422 }
4423 }
4424
4425 // The previous loop may not find a matching EMCP method, but
4426 // that doesn't mean that we can optimize and not go any
4427 // further back in the PreviousVersion generations. The EMCP
4428 // method for this generation could have already been made obsolete,
4429 // but there still may be an older EMCP method that has not
4430 // been made obsolete.
4431 }
4432
4433 if (++local_count >= obsolete_method_count) {
4434 // no more obsolete methods so bail out now
4435 break;
4436 }
4437 }
4438 }
4439 }
4440 }
4441
4442 // Save the scratch_class as the previous version if any of the methods are running.
4443 // The previous_versions are used to set breakpoints in EMCP methods and they are
4444 // also used to clean MethodData links to redefined methods that are no longer running.
4445 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4446 int emcp_method_count) {
4447 assert(Thread::current()->is_VM_thread(),
4448 "only VMThread can add previous versions");
4449
4450 ResourceMark rm;
4451 log_trace(redefine, class, iklass, add)
4452 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4453
4454 // Clean out old previous versions for this class
4455 purge_previous_version_list();
4456
4457 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4458 // a previous redefinition may be made obsolete by this redefinition.
4459 Array<Method*>* old_methods = scratch_class->methods();
4460 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4461
4462 // If the constant pool for this previous version of the class
4463 // is not marked as being on the stack, then none of the methods
4464 // in this previous version of the class are on the stack so
4465 // we don't need to add this as a previous version.
4466 ConstantPool* cp_ref = scratch_class->constants();
4467 if (!cp_ref->on_stack()) {
4468 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4469 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4470 return;
4471 }
4472
4473 // Add previous version if any methods are still running or if this is
4474 // a shared class which should never be removed.
4475 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4476 scratch_class->link_previous_versions(previous_versions());
4477 link_previous_versions(scratch_class);
4478 if (cp_ref->is_shared()) {
4479 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4480 } else {
4481 // We only set clean_previous_versions flag for processing during class
4482 // unloading for non-shared classes.
4483 _should_clean_previous_versions = true;
4484 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4485 }
4486 } // end add_previous_version()
4487
4488 #endif // INCLUDE_JVMTI
4489
4490 Method* InstanceKlass::method_with_idnum(int idnum) const {
4491 Method* m = nullptr;
4492 if (idnum < methods()->length()) {
4493 m = methods()->at(idnum);
4494 }
4495 if (m == nullptr || m->method_idnum() != idnum) {
4496 for (int index = 0; index < methods()->length(); ++index) {
4497 m = methods()->at(index);
4498 if (m->method_idnum() == idnum) {
4499 return m;
4500 }
4501 }
4502 // None found, return null for the caller to handle.
4503 return nullptr;
4504 }
4505 return m;
4506 }
4507
4508
4509 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4510 if (idnum >= methods()->length()) {
4511 return nullptr;
4512 }
4513 Method* m = methods()->at(idnum);
4514 if (m != nullptr && m->orig_method_idnum() == idnum) {
4515 return m;
4516 }
4517 // Obsolete method idnum does not match the original idnum
4518 for (int index = 0; index < methods()->length(); ++index) {
4519 m = methods()->at(index);
4520 if (m->orig_method_idnum() == idnum) {
4521 return m;
4522 }
4523 }
4524 // None found, return null for the caller to handle.
4525 return nullptr;
4526 }
4527
4528
4529 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4530 const InstanceKlass* holder = get_klass_version(version);
4531 if (holder == nullptr) {
4532 return nullptr; // The version of klass is gone, no method is found
4533 }
4534 return holder->method_with_orig_idnum(idnum);
4535 }
4536
4537 #if INCLUDE_JVMTI
4538 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4539 return _cached_class_file;
4540 }
4541
4542 jint InstanceKlass::get_cached_class_file_len() {
4543 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4544 }
4545
4546 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4547 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4548 }
4549 #endif
4550
4551 // Make a step iterating over the class hierarchy under the root class.
4552 // Skips subclasses if requested.
4553 void ClassHierarchyIterator::next() {
4554 assert(_current != nullptr, "required");
4555 if (_visit_subclasses && _current->subklass() != nullptr) {
4556 _current = _current->subklass();
4557 return; // visit next subclass
4558 }
4559 _visit_subclasses = true; // reset
4560 while (_current->next_sibling() == nullptr && _current != _root) {
4561 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4562 }
4563 if (_current == _root) {
4564 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4565 _current = nullptr;
4566 return;
4567 }
4568 _current = _current->next_sibling();
4569 return; // visit next sibling subclass
4570 }