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