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