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