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/markWord.hpp"
73 #include "oops/method.hpp"
74 #include "oops/oop.inline.hpp"
75 #include "oops/recordComponent.hpp"
76 #include "oops/symbol.hpp"
77 #include "oops/inlineKlass.hpp"
78 #include "prims/jvmtiExport.hpp"
79 #include "prims/jvmtiRedefineClasses.hpp"
80 #include "prims/jvmtiThreadState.hpp"
81 #include "prims/methodComparator.hpp"
82 #include "runtime/arguments.hpp"
83 #include "runtime/deoptimization.hpp"
84 #include "runtime/atomic.hpp"
85 #include "runtime/fieldDescriptor.inline.hpp"
86 #include "runtime/handles.inline.hpp"
87 #include "runtime/javaCalls.hpp"
88 #include "runtime/javaThread.inline.hpp"
89 #include "runtime/mutexLocker.hpp"
90 #include "runtime/orderAccess.hpp"
91 #include "runtime/os.inline.hpp"
92 #include "runtime/reflection.hpp"
93 #include "runtime/synchronizer.hpp"
94 #include "runtime/threads.hpp"
95 #include "services/classLoadingService.hpp"
96 #include "services/finalizerService.hpp"
97 #include "services/threadService.hpp"
98 #include "utilities/dtrace.hpp"
99 #include "utilities/events.hpp"
100 #include "utilities/macros.hpp"
101 #include "utilities/nativeStackPrinter.hpp"
102 #include "utilities/stringUtils.hpp"
103 #ifdef COMPILER1
104 #include "c1/c1_Compiler.hpp"
105 #endif
106 #if INCLUDE_JFR
107 #include "jfr/jfrEvents.hpp"
108 #endif
109
110 #ifdef DTRACE_ENABLED
111
112
113 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
114 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
115 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
116 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
117 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
118 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
119 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
120 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
121 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
122 { \
123 char* data = nullptr; \
124 int len = 0; \
125 Symbol* clss_name = name(); \
126 if (clss_name != nullptr) { \
127 data = (char*)clss_name->bytes(); \
128 len = clss_name->utf8_length(); \
129 } \
130 HOTSPOT_CLASS_INITIALIZATION_##type( \
131 data, len, (void*)class_loader(), thread_type); \
132 }
133
134 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
135 { \
136 char* data = nullptr; \
137 int len = 0; \
138 Symbol* clss_name = name(); \
139 if (clss_name != nullptr) { \
140 data = (char*)clss_name->bytes(); \
141 len = clss_name->utf8_length(); \
142 } \
143 HOTSPOT_CLASS_INITIALIZATION_##type( \
144 data, len, (void*)class_loader(), thread_type, wait); \
145 }
146
147 #else // ndef DTRACE_ENABLED
148
149 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
150 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
151
152 #endif // ndef DTRACE_ENABLED
153
154 void InlineLayoutInfo::metaspace_pointers_do(MetaspaceClosure* it) {
155 log_trace(cds)("Iter(InlineFieldInfo): %p", this);
156 it->push(&_klass);
157 }
158
159 bool InstanceKlass::_finalization_enabled = true;
160
161 static inline bool is_class_loader(const Symbol* class_name,
162 const ClassFileParser& parser) {
163 assert(class_name != nullptr, "invariant");
164
165 if (class_name == vmSymbols::java_lang_ClassLoader()) {
166 return true;
167 }
168
169 if (vmClasses::ClassLoader_klass_loaded()) {
170 const Klass* const super_klass = parser.super_klass();
171 if (super_klass != nullptr) {
172 if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
173 return true;
174 }
175 }
176 }
177 return false;
178 }
179
180 bool InstanceKlass::field_is_null_free_inline_type(int index) const {
181 return field(index).field_flags().is_null_free_inline_type();
182 }
183
184 bool InstanceKlass::is_class_in_loadable_descriptors_attribute(Symbol* name) const {
185 if (_loadable_descriptors == nullptr) return false;
186 for (int i = 0; i < _loadable_descriptors->length(); i++) {
187 Symbol* class_name = _constants->symbol_at(_loadable_descriptors->at(i));
188 if (class_name == name) return true;
189 }
190 return false;
191 }
192
193 static inline bool is_stack_chunk_class(const Symbol* class_name,
194 const ClassLoaderData* loader_data) {
195 return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
196 loader_data->is_the_null_class_loader_data());
197 }
198
199 // private: called to verify that k is a static member of this nest.
200 // We know that k is an instance class in the same package and hence the
201 // same classloader.
202 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
203 assert(!is_hidden(), "unexpected hidden class");
204 if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
205 if (log_is_enabled(Trace, class, nestmates)) {
206 ResourceMark rm(current);
207 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
208 k->external_name(), this->external_name());
209 }
210 return false;
211 }
212
213 if (log_is_enabled(Trace, class, nestmates)) {
214 ResourceMark rm(current);
215 log_trace(class, nestmates)("Checking nest membership of %s in %s",
216 k->external_name(), this->external_name());
217 }
218
219 // Check for the named class in _nest_members.
220 // We don't resolve, or load, any classes.
221 for (int i = 0; i < _nest_members->length(); i++) {
222 int cp_index = _nest_members->at(i);
223 Symbol* name = _constants->klass_name_at(cp_index);
224 if (name == k->name()) {
225 log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
226 return true;
227 }
228 }
229 log_trace(class, nestmates)("- class is NOT a nest member!");
230 return false;
231 }
232
233 // Called to verify that k is a permitted subclass of this class.
234 // The incoming stringStream is used to format the messages for error logging and for the caller
235 // to use for exception throwing.
236 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
237 Thread* current = Thread::current();
238 assert(k != nullptr, "sanity check");
239 assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
240 "unexpected empty _permitted_subclasses array");
241
242 if (log_is_enabled(Trace, class, sealed)) {
243 ResourceMark rm(current);
244 log_trace(class, sealed)("Checking for permitted subclass %s in %s",
245 k->external_name(), this->external_name());
246 }
247
248 // Check that the class and its super are in the same module.
249 if (k->module() != this->module()) {
250 ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
251 "and sealed class %s is in module '%s' with loader %s",
252 k->external_name(),
253 k->module()->name_as_C_string(),
254 k->module()->loader_data()->loader_name_and_id(),
255 this->external_name(),
256 this->module()->name_as_C_string(),
257 this->module()->loader_data()->loader_name_and_id());
258 log_trace(class, sealed)(" - %s", ss.as_string());
259 return false;
260 }
261
262 if (!k->is_public() && !is_same_class_package(k)) {
263 ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
264 "and sealed class %s is in package '%s' with classloader %s",
265 k->external_name(),
266 k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
267 k->module()->loader_data()->loader_name_and_id(),
268 this->external_name(),
269 this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
270 this->module()->loader_data()->loader_name_and_id());
271 log_trace(class, sealed)(" - %s", ss.as_string());
272 return false;
273 }
274
275 for (int i = 0; i < _permitted_subclasses->length(); i++) {
276 int cp_index = _permitted_subclasses->at(i);
277 Symbol* name = _constants->klass_name_at(cp_index);
278 if (name == k->name()) {
279 log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
280 return true;
281 }
282 }
283
284 ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
285 k->external_name(), this->external_name());
286 log_trace(class, sealed)(" - %s", ss.as_string());
287 return false;
288 }
289
290 // Return nest-host class, resolving, validating and saving it if needed.
291 // In cases where this is called from a thread that cannot do classloading
292 // (such as a native JIT thread) then we simply return null, which in turn
293 // causes the access check to return false. Such code will retry the access
294 // from a more suitable environment later. Otherwise the _nest_host is always
295 // set once this method returns.
296 // Any errors from nest-host resolution must be preserved so they can be queried
297 // from higher-level access checking code, and reported as part of access checking
298 // exceptions.
299 // VirtualMachineErrors are propagated with a null return.
300 // Under any conditions where the _nest_host can be set to non-null the resulting
301 // value of it and, if applicable, the nest host resolution/validation error,
302 // are idempotent.
303 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
304 InstanceKlass* nest_host_k = _nest_host;
305 if (nest_host_k != nullptr) {
306 return nest_host_k;
307 }
308
309 ResourceMark rm(THREAD);
310
311 // need to resolve and save our nest-host class.
312 if (_nest_host_index != 0) { // we have a real nest_host
313 // Before trying to resolve check if we're in a suitable context
314 bool can_resolve = THREAD->can_call_java();
315 if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
316 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
317 this->external_name());
318 return nullptr; // sentinel to say "try again from a different context"
319 }
320
321 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
322 this->external_name(),
323 _constants->klass_name_at(_nest_host_index)->as_C_string());
324
325 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
326 if (HAS_PENDING_EXCEPTION) {
327 if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
328 return nullptr; // propagate VMEs
329 }
330 stringStream ss;
331 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
332 ss.print("Nest host resolution of %s with host %s failed: ",
333 this->external_name(), target_host_class);
334 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
335 const char* msg = ss.as_string(true /* on C-heap */);
336 constantPoolHandle cph(THREAD, constants());
337 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
338 CLEAR_PENDING_EXCEPTION;
339
340 log_trace(class, nestmates)("%s", msg);
341 } else {
342 // A valid nest-host is an instance class in the current package that lists this
343 // class as a nest member. If any of these conditions are not met the class is
344 // its own nest-host.
345 const char* error = nullptr;
346
347 // JVMS 5.4.4 indicates package check comes first
348 if (is_same_class_package(k)) {
349 // Now check actual membership. We can't be a member if our "host" is
350 // not an instance class.
351 if (k->is_instance_klass()) {
352 nest_host_k = InstanceKlass::cast(k);
353 bool is_member = nest_host_k->has_nest_member(THREAD, this);
354 if (is_member) {
355 _nest_host = nest_host_k; // save resolved nest-host value
356
357 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
358 this->external_name(), k->external_name());
359 return nest_host_k;
360 } else {
361 error = "current type is not listed as a nest member";
362 }
363 } else {
364 error = "host is not an instance class";
365 }
366 } else {
367 error = "types are in different packages";
368 }
369
370 // something went wrong, so record what and log it
371 {
372 stringStream ss;
373 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
374 this->external_name(),
375 this->class_loader_data()->loader_name_and_id(),
376 k->external_name(),
377 k->class_loader_data()->loader_name_and_id(),
378 error);
379 const char* msg = ss.as_string(true /* on C-heap */);
380 constantPoolHandle cph(THREAD, constants());
381 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
382 log_trace(class, nestmates)("%s", msg);
383 }
384 }
385 } else {
386 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
387 this->external_name());
388 }
389
390 // Either not in an explicit nest, or else an error occurred, so
391 // the nest-host is set to `this`. Any thread that sees this assignment
392 // will also see any setting of nest_host_error(), if applicable.
393 return (_nest_host = this);
394 }
395
396 // Dynamic nest member support: set this class's nest host to the given class.
397 // This occurs as part of the class definition, as soon as the instanceKlass
398 // has been created and doesn't require further resolution. The code:
399 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
400 // results in:
401 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
402 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
403 // We also know the "host" is a valid nest-host in the same package so we can
404 // assert some of those facts.
405 void InstanceKlass::set_nest_host(InstanceKlass* host) {
406 assert(is_hidden(), "must be a hidden class");
407 assert(host != nullptr, "null nest host specified");
408 assert(_nest_host == nullptr, "current class has resolved nest-host");
409 assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
410 nest_host_error());
411 assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
412 (host->_nest_host == host), "proposed host is not a valid nest-host");
413 // Can't assert this as package is not set yet:
414 // assert(is_same_class_package(host), "proposed host is in wrong package");
415
416 if (log_is_enabled(Trace, class, nestmates)) {
417 ResourceMark rm;
418 const char* msg = "";
419 // a hidden class does not expect a statically defined nest-host
420 if (_nest_host_index > 0) {
421 msg = "(the NestHost attribute in the current class is ignored)";
422 } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
423 msg = "(the NestMembers attribute in the current class is ignored)";
424 }
425 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
426 this->external_name(),
427 host->external_name(),
428 msg);
429 }
430 // set dynamic nest host
431 _nest_host = host;
432 // Record dependency to keep nest host from being unloaded before this class.
433 ClassLoaderData* this_key = class_loader_data();
434 assert(this_key != nullptr, "sanity");
435 this_key->record_dependency(host);
436 }
437
438 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
439 // or we are k's nest_host - all of which is covered by comparing the two
440 // resolved_nest_hosts.
441 // Any exceptions (i.e. VMEs) are propagated.
442 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
443
444 assert(this != k, "this should be handled by higher-level code");
445
446 // Per JVMS 5.4.4 we first resolve and validate the current class, then
447 // the target class k.
448
449 InstanceKlass* cur_host = nest_host(CHECK_false);
450 if (cur_host == nullptr) {
451 return false;
452 }
453
454 Klass* k_nest_host = k->nest_host(CHECK_false);
455 if (k_nest_host == nullptr) {
456 return false;
457 }
458
459 bool access = (cur_host == k_nest_host);
460
461 ResourceMark rm(THREAD);
462 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
463 this->external_name(),
464 access ? "" : "NOT ",
465 k->external_name());
466 return access;
467 }
468
469 const char* InstanceKlass::nest_host_error() {
470 if (_nest_host_index == 0) {
471 return nullptr;
472 } else {
473 constantPoolHandle cph(Thread::current(), constants());
474 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
475 }
476 }
477
478 void* InstanceKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size,
479 bool use_class_space, TRAPS) throw() {
480 return Metaspace::allocate(loader_data, word_size, ClassType, use_class_space, THREAD);
481 }
482
483 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
484 const int size = InstanceKlass::size(parser.vtable_size(),
485 parser.itable_size(),
486 nonstatic_oop_map_size(parser.total_oop_map_count()),
487 parser.is_interface(),
488 parser.is_inline_type());
489
490 const Symbol* const class_name = parser.class_name();
491 assert(class_name != nullptr, "invariant");
492 ClassLoaderData* loader_data = parser.loader_data();
493 assert(loader_data != nullptr, "invariant");
494
495 InstanceKlass* ik;
496 const bool use_class_space = parser.klass_needs_narrow_id();
497
498 // Allocation
499 if (parser.is_instance_ref_klass()) {
500 // java.lang.ref.Reference
501 ik = new (loader_data, size, use_class_space, THREAD) InstanceRefKlass(parser);
502 } else if (class_name == vmSymbols::java_lang_Class()) {
503 // mirror - java.lang.Class
504 ik = new (loader_data, size, use_class_space, THREAD) InstanceMirrorKlass(parser);
505 } else if (is_stack_chunk_class(class_name, loader_data)) {
506 // stack chunk
507 ik = new (loader_data, size, use_class_space, THREAD) InstanceStackChunkKlass(parser);
508 } else if (is_class_loader(class_name, parser)) {
509 // class loader - java.lang.ClassLoader
510 ik = new (loader_data, size, use_class_space, THREAD) InstanceClassLoaderKlass(parser);
511 } else if (parser.is_inline_type()) {
512 // inline type
513 ik = new (loader_data, size, use_class_space, THREAD) InlineKlass(parser);
514 } else {
515 // normal
516 ik = new (loader_data, size, use_class_space, THREAD) InstanceKlass(parser);
517 }
518
519 if (ik != nullptr && UseCompressedClassPointers && use_class_space) {
520 assert(CompressedKlassPointers::is_encodable(ik),
521 "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
522 }
523
524 // Check for pending exception before adding to the loader data and incrementing
525 // class count. Can get OOM here.
526 if (HAS_PENDING_EXCEPTION) {
527 return nullptr;
528 }
529
530 #ifdef ASSERT
531 ik->bounds_check((address) ik->start_of_vtable(), false, size);
532 ik->bounds_check((address) ik->start_of_itable(), false, size);
533 ik->bounds_check((address) ik->end_of_itable(), true, size);
534 ik->bounds_check((address) ik->end_of_nonstatic_oop_maps(), true, size);
535 #endif //ASSERT
536 return ik;
537 }
538
539 #ifndef PRODUCT
540 bool InstanceKlass::bounds_check(address addr, bool edge_ok, intptr_t size_in_bytes) const {
541 const char* bad = nullptr;
542 address end = nullptr;
543 if (addr < (address)this) {
544 bad = "before";
545 } else if (addr == (address)this) {
546 if (edge_ok) return true;
547 bad = "just before";
548 } else if (addr == (end = (address)this + sizeof(intptr_t) * (size_in_bytes < 0 ? size() : size_in_bytes))) {
549 if (edge_ok) return true;
550 bad = "just after";
551 } else if (addr > end) {
552 bad = "after";
553 } else {
554 return true;
555 }
556 tty->print_cr("%s object bounds: " INTPTR_FORMAT " [" INTPTR_FORMAT ".." INTPTR_FORMAT "]",
557 bad, (intptr_t)addr, (intptr_t)this, (intptr_t)end);
558 Verbose = WizardMode = true; this->print(); //@@
559 return false;
560 }
561 #endif //PRODUCT
562
563 // copy method ordering from resource area to Metaspace
564 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
565 if (m != nullptr) {
566 // allocate a new array and copy contents (memcpy?)
567 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
568 for (int i = 0; i < m->length(); i++) {
569 _method_ordering->at_put(i, m->at(i));
570 }
571 } else {
572 _method_ordering = Universe::the_empty_int_array();
573 }
574 }
575
576 // create a new array of vtable_indices for default methods
577 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
578 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
579 assert(default_vtable_indices() == nullptr, "only create once");
580 set_default_vtable_indices(vtable_indices);
581 return vtable_indices;
582 }
583
584
585 InstanceKlass::InstanceKlass() {
586 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
587 }
588
589 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, markWord prototype_header, ReferenceType reference_type) :
590 Klass(kind, prototype_header),
591 _nest_members(nullptr),
592 _nest_host(nullptr),
593 _permitted_subclasses(nullptr),
594 _record_components(nullptr),
595 _static_field_size(parser.static_field_size()),
596 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
597 _itable_len(parser.itable_size()),
598 _nest_host_index(0),
599 _init_state(allocated),
600 _reference_type(reference_type),
601 _init_thread(nullptr),
602 _inline_layout_info_array(nullptr),
603 _loadable_descriptors(nullptr),
604 _adr_inlineklass_fixed_block(nullptr)
605 {
606 set_vtable_length(parser.vtable_size());
607 set_access_flags(parser.access_flags());
608 if (parser.is_hidden()) set_is_hidden();
609 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
610 false));
611 if (parser.has_inline_fields()) {
612 set_has_inline_type_fields();
613 }
614
615 assert(nullptr == _methods, "underlying memory not zeroed?");
616 assert(is_instance_klass(), "is layout incorrect?");
617 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
618 }
619
620 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
621 Array<Method*>* methods) {
622 if (methods != nullptr && methods != Universe::the_empty_method_array() &&
623 !methods->is_shared()) {
624 for (int i = 0; i < methods->length(); i++) {
625 Method* method = methods->at(i);
626 if (method == nullptr) continue; // maybe null if error processing
627 // Only want to delete methods that are not executing for RedefineClasses.
628 // The previous version will point to them so they're not totally dangling
629 assert (!method->on_stack(), "shouldn't be called with methods on stack");
630 MetadataFactory::free_metadata(loader_data, method);
631 }
632 MetadataFactory::free_array<Method*>(loader_data, methods);
633 }
634 }
635
636 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
637 const Klass* super_klass,
638 Array<InstanceKlass*>* local_interfaces,
639 Array<InstanceKlass*>* transitive_interfaces) {
640 // Only deallocate transitive interfaces if not empty, same as super class
641 // or same as local interfaces. See code in parseClassFile.
642 Array<InstanceKlass*>* ti = transitive_interfaces;
643 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
644 // check that the interfaces don't come from super class
645 Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
646 InstanceKlass::cast(super_klass)->transitive_interfaces();
647 if (ti != sti && ti != nullptr && !ti->is_shared()) {
648 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
649 }
650 }
651
652 // local interfaces can be empty
653 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
654 local_interfaces != nullptr && !local_interfaces->is_shared()) {
655 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
656 }
657 }
658
659 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
660 Array<RecordComponent*>* record_components) {
661 if (record_components != nullptr && !record_components->is_shared()) {
662 for (int i = 0; i < record_components->length(); i++) {
663 RecordComponent* record_component = record_components->at(i);
664 MetadataFactory::free_metadata(loader_data, record_component);
665 }
666 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
667 }
668 }
669
670 // This function deallocates the metadata and C heap pointers that the
671 // InstanceKlass points to.
672 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
673 // Orphan the mirror first, CMS thinks it's still live.
674 if (java_mirror() != nullptr) {
675 java_lang_Class::set_klass(java_mirror(), nullptr);
676 }
677
678 // Also remove mirror from handles
679 loader_data->remove_handle(_java_mirror);
680
681 // Need to take this class off the class loader data list.
682 loader_data->remove_class(this);
683
684 // The array_klass for this class is created later, after error handling.
685 // For class redefinition, we keep the original class so this scratch class
686 // doesn't have an array class. Either way, assert that there is nothing
687 // to deallocate.
688 assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
689
690 // Release C heap allocated data that this points to, which includes
691 // reference counting symbol names.
692 // Can't release the constant pool or MethodData C heap data here because the constant
693 // pool can be deallocated separately from the InstanceKlass for default methods and
694 // redefine classes. MethodData can also be released separately.
695 release_C_heap_structures(/* release_sub_metadata */ false);
696
697 deallocate_methods(loader_data, methods());
698 set_methods(nullptr);
699
700 deallocate_record_components(loader_data, record_components());
701 set_record_components(nullptr);
702
703 if (method_ordering() != nullptr &&
704 method_ordering() != Universe::the_empty_int_array() &&
705 !method_ordering()->is_shared()) {
706 MetadataFactory::free_array<int>(loader_data, method_ordering());
707 }
708 set_method_ordering(nullptr);
709
710 // default methods can be empty
711 if (default_methods() != nullptr &&
712 default_methods() != Universe::the_empty_method_array() &&
713 !default_methods()->is_shared()) {
714 MetadataFactory::free_array<Method*>(loader_data, default_methods());
715 }
716 // Do NOT deallocate the default methods, they are owned by superinterfaces.
717 set_default_methods(nullptr);
718
719 // default methods vtable indices can be empty
720 if (default_vtable_indices() != nullptr &&
721 !default_vtable_indices()->is_shared()) {
722 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
723 }
724 set_default_vtable_indices(nullptr);
725
726
727 // This array is in Klass, but remove it with the InstanceKlass since
728 // this place would be the only caller and it can share memory with transitive
729 // interfaces.
730 if (secondary_supers() != nullptr &&
731 secondary_supers() != Universe::the_empty_klass_array() &&
732 // see comments in compute_secondary_supers about the following cast
733 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
734 !secondary_supers()->is_shared()) {
735 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
736 }
737 set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
738
739 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
740 set_transitive_interfaces(nullptr);
741 set_local_interfaces(nullptr);
742
743 if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->is_shared()) {
744 MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
745 }
746 set_fieldinfo_stream(nullptr);
747
748 if (fields_status() != nullptr && !fields_status()->is_shared()) {
749 MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
750 }
751 set_fields_status(nullptr);
752
753 if (inline_layout_info_array() != nullptr) {
754 MetadataFactory::free_array<InlineLayoutInfo>(loader_data, inline_layout_info_array());
755 }
756 set_inline_layout_info_array(nullptr);
757
758 // If a method from a redefined class is using this constant pool, don't
759 // delete it, yet. The new class's previous version will point to this.
760 if (constants() != nullptr) {
761 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
762 if (!constants()->is_shared()) {
763 MetadataFactory::free_metadata(loader_data, constants());
764 }
765 // Delete any cached resolution errors for the constant pool
766 SystemDictionary::delete_resolution_error(constants());
767
768 set_constants(nullptr);
769 }
770
771 if (inner_classes() != nullptr &&
772 inner_classes() != Universe::the_empty_short_array() &&
773 !inner_classes()->is_shared()) {
774 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
775 }
776 set_inner_classes(nullptr);
777
778 if (nest_members() != nullptr &&
779 nest_members() != Universe::the_empty_short_array() &&
780 !nest_members()->is_shared()) {
781 MetadataFactory::free_array<jushort>(loader_data, nest_members());
782 }
783 set_nest_members(nullptr);
784
785 if (permitted_subclasses() != nullptr &&
786 permitted_subclasses() != Universe::the_empty_short_array() &&
787 !permitted_subclasses()->is_shared()) {
788 MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
789 }
790 set_permitted_subclasses(nullptr);
791
792 if (loadable_descriptors() != nullptr &&
793 loadable_descriptors() != Universe::the_empty_short_array() &&
794 !loadable_descriptors()->is_shared()) {
795 MetadataFactory::free_array<jushort>(loader_data, loadable_descriptors());
796 }
797 set_loadable_descriptors(nullptr);
798
799 // We should deallocate the Annotations instance if it's not in shared spaces.
800 if (annotations() != nullptr && !annotations()->is_shared()) {
801 MetadataFactory::free_metadata(loader_data, annotations());
802 }
803 set_annotations(nullptr);
804
805 SystemDictionaryShared::handle_class_unloading(this);
806
807 #if INCLUDE_CDS_JAVA_HEAP
808 if (CDSConfig::is_dumping_heap()) {
809 HeapShared::remove_scratch_objects(this);
810 }
811 #endif
812 }
813
814 bool InstanceKlass::is_record() const {
815 return _record_components != nullptr &&
816 is_final() &&
817 java_super() == vmClasses::Record_klass();
818 }
819
820 bool InstanceKlass::is_sealed() const {
821 return _permitted_subclasses != nullptr &&
822 _permitted_subclasses != Universe::the_empty_short_array();
823 }
824
825 // JLS 8.9: An enum class is either implicitly final and derives
826 // from java.lang.Enum, or else is implicitly sealed to its
827 // anonymous subclasses. This query detects both kinds.
828 // It does not validate the finality or
829 // sealing conditions: it merely checks for a super of Enum.
830 // This is sufficient for recognizing well-formed enums.
831 bool InstanceKlass::is_enum_subclass() const {
832 InstanceKlass* s = java_super();
833 return (s == vmClasses::Enum_klass() ||
834 (s != nullptr && s->java_super() == vmClasses::Enum_klass()));
835 }
836
837 bool InstanceKlass::should_be_initialized() const {
838 return !is_initialized();
839 }
840
841 klassItable InstanceKlass::itable() const {
842 return klassItable(const_cast<InstanceKlass*>(this));
843 }
844
845 // JVMTI spec thinks there are signers and protection domain in the
846 // instanceKlass. These accessors pretend these fields are there.
847 // The hprof specification also thinks these fields are in InstanceKlass.
848 oop InstanceKlass::protection_domain() const {
849 // return the protection_domain from the mirror
850 return java_lang_Class::protection_domain(java_mirror());
851 }
852
853 objArrayOop InstanceKlass::signers() const {
854 // return the signers from the mirror
855 return java_lang_Class::signers(java_mirror());
856 }
857
858 oop InstanceKlass::init_lock() const {
859 // return the init lock from the mirror
860 oop lock = java_lang_Class::init_lock(java_mirror());
861 // Prevent reordering with any access of initialization state
862 OrderAccess::loadload();
863 assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
864 "only fully initialized state can have a null lock");
865 return lock;
866 }
867
868 // Set the initialization lock to null so the object can be GC'ed. Any racing
869 // threads to get this lock will see a null lock and will not lock.
870 // That's okay because they all check for initialized state after getting
871 // the lock and return.
872 void InstanceKlass::fence_and_clear_init_lock() {
873 // make sure previous stores are all done, notably the init_state.
874 OrderAccess::storestore();
875 java_lang_Class::clear_init_lock(java_mirror());
876 assert(!is_not_initialized(), "class must be initialized now");
877 }
878
879
880 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
881 // process. The step comments refers to the procedure described in that section.
882 // Note: implementation moved to static method to expose the this pointer.
883 void InstanceKlass::initialize(TRAPS) {
884 if (this->should_be_initialized()) {
885 initialize_impl(CHECK);
886 // Note: at this point the class may be initialized
887 // OR it may be in the state of being initialized
888 // in case of recursive initialization!
889 } else {
890 assert(is_initialized(), "sanity check");
891 }
892 }
893
894 #ifdef ASSERT
895 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
896 assert(has_aot_initialized_mirror(), "must be");
897
898 InstanceKlass* s = java_super();
899 if (s != nullptr) {
900 DEBUG_ONLY(ResourceMark rm);
901 assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
902 s->external_name(), external_name());
903 s->assert_no_clinit_will_run_for_aot_initialized_class();
904 }
905
906 Array<InstanceKlass*>* interfaces = local_interfaces();
907 int len = interfaces->length();
908 for (int i = 0; i < len; i++) {
909 InstanceKlass* intf = interfaces->at(i);
910 if (!intf->is_initialized()) {
911 ResourceMark rm;
912 // Note: an interface needs to be marked as is_initialized() only if
913 // - it has a <clinit>
914 // - it has declared a default method.
915 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
916 "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
917 intf->external_name(), external_name());
918 }
919 }
920 }
921 #endif
922
923 #if INCLUDE_CDS
924 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
925 assert(has_aot_initialized_mirror(), "must be");
926 assert(CDSConfig::is_loading_heap(), "must be");
927 assert(CDSConfig::is_using_aot_linked_classes(), "must be");
928 assert_no_clinit_will_run_for_aot_initialized_class();
929
930 if (is_initialized()) {
931 return;
932 }
933
934 if (log_is_enabled(Info, cds, init)) {
935 ResourceMark rm;
936 log_info(cds, init)("%s (aot-inited)", external_name());
937 }
938
939 link_class(CHECK);
940
941 #ifdef ASSERT
942 {
943 Handle h_init_lock(THREAD, init_lock());
944 ObjectLocker ol(h_init_lock, THREAD);
945 assert(!is_initialized(), "sanity");
946 assert(!is_being_initialized(), "sanity");
947 assert(!is_in_error_state(), "sanity");
948 }
949 #endif
950
951 set_init_thread(THREAD);
952 AOTClassInitializer::call_runtime_setup(THREAD, this);
953 set_initialization_state_and_notify(fully_initialized, CHECK);
954 }
955 #endif
956
957 bool InstanceKlass::verify_code(TRAPS) {
958 // 1) Verify the bytecodes
959 return Verifier::verify(this, should_verify_class(), THREAD);
960 }
961
962 void InstanceKlass::link_class(TRAPS) {
963 assert(is_loaded(), "must be loaded");
964 if (!is_linked()) {
965 link_class_impl(CHECK);
966 }
967 }
968
969 // Called to verify that a class can link during initialization, without
970 // throwing a VerifyError.
971 bool InstanceKlass::link_class_or_fail(TRAPS) {
972 assert(is_loaded(), "must be loaded");
973 if (!is_linked()) {
974 link_class_impl(CHECK_false);
975 }
976 return is_linked();
977 }
978
979 bool InstanceKlass::link_class_impl(TRAPS) {
980 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
981 // This is for CDS static dump only -- we use the in_error_state to indicate that
982 // the class has failed verification. Throwing the NoClassDefFoundError here is just
983 // a convenient way to stop repeat attempts to verify the same (bad) class.
984 //
985 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
986 // if we are executing Java code. This is not a problem for CDS dumping phase since
987 // it doesn't execute any Java code.
988 ResourceMark rm(THREAD);
989 // Names are all known to be < 64k so we know this formatted message is not excessively large.
990 Exceptions::fthrow(THREAD_AND_LOCATION,
991 vmSymbols::java_lang_NoClassDefFoundError(),
992 "Class %s, or one of its supertypes, failed class initialization",
993 external_name());
994 return false;
995 }
996 // return if already verified
997 if (is_linked()) {
998 return true;
999 }
1000
1001 // Timing
1002 // timer handles recursion
1003 JavaThread* jt = THREAD;
1004
1005 // link super class before linking this class
1006 Klass* super_klass = super();
1007 if (super_klass != nullptr) {
1008 if (super_klass->is_interface()) { // check if super class is an interface
1009 ResourceMark rm(THREAD);
1010 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1011 Exceptions::fthrow(
1012 THREAD_AND_LOCATION,
1013 vmSymbols::java_lang_IncompatibleClassChangeError(),
1014 "class %s has interface %s as super class",
1015 external_name(),
1016 super_klass->external_name()
1017 );
1018 return false;
1019 }
1020
1021 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
1022 ik_super->link_class_impl(CHECK_false);
1023 }
1024
1025 // link all interfaces implemented by this class before linking this class
1026 Array<InstanceKlass*>* interfaces = local_interfaces();
1027 int num_interfaces = interfaces->length();
1028 for (int index = 0; index < num_interfaces; index++) {
1029 InstanceKlass* interk = interfaces->at(index);
1030 interk->link_class_impl(CHECK_false);
1031 }
1032
1033
1034 // If a class declares a method that uses an inline class as an argument
1035 // type or return inline type, this inline class must be loaded during the
1036 // linking of this class because size and properties of the inline class
1037 // must be known in order to be able to perform inline type optimizations.
1038 // The implementation below is an approximation of this rule, the code
1039 // iterates over all methods of the current class (including overridden
1040 // methods), not only the methods declared by this class. This
1041 // approximation makes the code simpler, and doesn't change the semantic
1042 // because classes declaring methods overridden by the current class are
1043 // linked (and have performed their own pre-loading) before the linking
1044 // of the current class.
1045
1046
1047 // Note:
1048 // Inline class types are loaded during
1049 // the loading phase (see ClassFileParser::post_process_parsed_stream()).
1050 // Inline class types used as element types for array creation
1051 // are not pre-loaded. Their loading is triggered by either anewarray
1052 // or multianewarray bytecodes.
1053
1054 // Could it be possible to do the following processing only if the
1055 // class uses inline types?
1056 if (EnableValhalla) {
1057 ResourceMark rm(THREAD);
1058 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1059 if (fs.is_null_free_inline_type() && fs.access_flags().is_static()) {
1060 assert(fs.access_flags().is_strict(), "null-free fields must be strict");
1061 Symbol* sig = fs.signature();
1062 TempNewSymbol s = Signature::strip_envelope(sig);
1063 if (s != name()) {
1064 log_info(class, preload)("Preloading class %s during linking of class %s. Cause: a null-free static field is declared with this type", s->as_C_string(), name()->as_C_string());
1065 Klass* klass = SystemDictionary::resolve_or_fail(s,
1066 Handle(THREAD, class_loader()), true,
1067 CHECK_false);
1068 if (HAS_PENDING_EXCEPTION) {
1069 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) failed: %s",
1070 s->as_C_string(), name()->as_C_string(), PENDING_EXCEPTION->klass()->name()->as_C_string());
1071 return false; // Exception is still pending
1072 }
1073 log_info(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) succeeded",
1074 s->as_C_string(), name()->as_C_string());
1075 assert(klass != nullptr, "Sanity check");
1076 if (klass->is_abstract()) {
1077 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1078 err_msg("Class %s expects class %s to be concrete value class, but it is an abstract class",
1079 name()->as_C_string(),
1080 InstanceKlass::cast(klass)->external_name()), false);
1081 }
1082 if (!klass->is_inline_klass()) {
1083 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1084 err_msg("class %s expects class %s to be a value class but it is an identity class",
1085 name()->as_C_string(), klass->external_name()), false);
1086 }
1087 InlineKlass* vk = InlineKlass::cast(klass);
1088 // the inline_type_field_klasses_array might have been loaded with CDS, so update only if not already set and check consistency
1089 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1090 if (li->klass() == nullptr) {
1091 li->set_klass(InlineKlass::cast(vk));
1092 li->set_kind(LayoutKind::REFERENCE);
1093 }
1094 assert(get_inline_type_field_klass(fs.index()) == vk, "Must match");
1095 } else {
1096 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1097 if (li->klass() == nullptr) {
1098 li->set_klass(InlineKlass::cast(this));
1099 li->set_kind(LayoutKind::REFERENCE);
1100 }
1101 assert(get_inline_type_field_klass(fs.index()) == this, "Must match");
1102 }
1103 }
1104 }
1105
1106 // Aggressively preloading all classes from the LoadableDescriptors attribute
1107 if (loadable_descriptors() != nullptr) {
1108 HandleMark hm(THREAD);
1109 for (int i = 0; i < loadable_descriptors()->length(); i++) {
1110 Symbol* sig = constants()->symbol_at(loadable_descriptors()->at(i));
1111 if (!Signature::has_envelope(sig)) continue;
1112 TempNewSymbol class_name = Signature::strip_envelope(sig);
1113 if (class_name == name()) continue;
1114 log_info(class, preload)("Preloading class %s during linking of class %s because of the class is listed in the LoadableDescriptors attribute", sig->as_C_string(), name()->as_C_string());
1115 oop loader = class_loader();
1116 Klass* klass = SystemDictionary::resolve_or_null(class_name,
1117 Handle(THREAD, loader), THREAD);
1118 if (HAS_PENDING_EXCEPTION) {
1119 CLEAR_PENDING_EXCEPTION;
1120 }
1121 if (klass != nullptr) {
1122 log_info(class, preload)("Preloading of class %s during linking of class %s (cause: LoadableDescriptors attribute) succeeded", class_name->as_C_string(), name()->as_C_string());
1123 if (!klass->is_inline_klass()) {
1124 // Non value class are allowed by the current spec, but it could be an indication of an issue so let's log a warning
1125 log_warning(class, preload)("Preloading class %s during linking of class %s (cause: LoadableDescriptors attribute) but loaded class is not a value class", class_name->as_C_string(), name()->as_C_string());
1126 }
1127 } else {
1128 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: LoadableDescriptors attribute) failed", class_name->as_C_string(), name()->as_C_string());
1129 }
1130 }
1131 }
1132 }
1133
1134 // in case the class is linked in the process of linking its superclasses
1135 if (is_linked()) {
1136 return true;
1137 }
1138
1139 // trace only the link time for this klass that includes
1140 // the verification time
1141 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
1142 ClassLoader::perf_class_link_selftime(),
1143 ClassLoader::perf_classes_linked(),
1144 jt->get_thread_stat()->perf_recursion_counts_addr(),
1145 jt->get_thread_stat()->perf_timers_addr(),
1146 PerfClassTraceTime::CLASS_LINK);
1147
1148 // verification & rewriting
1149 {
1150 HandleMark hm(THREAD);
1151 Handle h_init_lock(THREAD, init_lock());
1152 ObjectLocker ol(h_init_lock, jt);
1153 // rewritten will have been set if loader constraint error found
1154 // on an earlier link attempt
1155 // don't verify or rewrite if already rewritten
1156 //
1157
1158 if (!is_linked()) {
1159 if (!is_rewritten()) {
1160 if (is_shared()) {
1161 assert(!verified_at_dump_time(), "must be");
1162 }
1163 {
1164 bool verify_ok = verify_code(THREAD);
1165 if (!verify_ok) {
1166 return false;
1167 }
1168 }
1169
1170 // Just in case a side-effect of verify linked this class already
1171 // (which can sometimes happen since the verifier loads classes
1172 // using custom class loaders, which are free to initialize things)
1173 if (is_linked()) {
1174 return true;
1175 }
1176
1177 // also sets rewritten
1178 rewrite_class(CHECK_false);
1179 } else if (is_shared()) {
1180 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1181 }
1182
1183 // relocate jsrs and link methods after they are all rewritten
1184 link_methods(CHECK_false);
1185
1186 // Initialize the vtable and interface table after
1187 // methods have been rewritten since rewrite may
1188 // fabricate new Method*s.
1189 // also does loader constraint checking
1190 //
1191 // initialize_vtable and initialize_itable need to be rerun
1192 // for a shared class if
1193 // 1) the class is loaded by custom class loader or
1194 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1195 // 3) the class was not verified during dump time
1196 bool need_init_table = true;
1197 if (is_shared() && verified_at_dump_time() &&
1198 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1199 need_init_table = false;
1200 }
1201 if (need_init_table) {
1202 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1203 itable().initialize_itable_and_check_constraints(CHECK_false);
1204 }
1205 #ifdef ASSERT
1206 vtable().verify(tty, true);
1207 // In case itable verification is ever added.
1208 // itable().verify(tty, true);
1209 #endif
1210 if (Universe::is_fully_initialized()) {
1211 DeoptimizationScope deopt_scope;
1212 {
1213 // Now mark all code that assumes the class is not linked.
1214 // Set state under the Compile_lock also.
1215 MutexLocker ml(THREAD, Compile_lock);
1216
1217 set_init_state(linked);
1218 CodeCache::mark_dependents_on(&deopt_scope, this);
1219 }
1220 // Perform the deopt handshake outside Compile_lock.
1221 deopt_scope.deoptimize_marked();
1222 } else {
1223 set_init_state(linked);
1224 }
1225 if (JvmtiExport::should_post_class_prepare()) {
1226 JvmtiExport::post_class_prepare(THREAD, this);
1227 }
1228 }
1229 }
1230 return true;
1231 }
1232
1233 // Rewrite the byte codes of all of the methods of a class.
1234 // The rewriter must be called exactly once. Rewriting must happen after
1235 // verification but before the first method of the class is executed.
1236 void InstanceKlass::rewrite_class(TRAPS) {
1237 assert(is_loaded(), "must be loaded");
1238 if (is_rewritten()) {
1239 assert(is_shared(), "rewriting an unshared class?");
1240 return;
1241 }
1242 Rewriter::rewrite(this, CHECK);
1243 set_rewritten();
1244 }
1245
1246 // Now relocate and link method entry points after class is rewritten.
1247 // This is outside is_rewritten flag. In case of an exception, it can be
1248 // executed more than once.
1249 void InstanceKlass::link_methods(TRAPS) {
1250 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1251
1252 int len = methods()->length();
1253 for (int i = len-1; i >= 0; i--) {
1254 methodHandle m(THREAD, methods()->at(i));
1255
1256 // Set up method entry points for compiler and interpreter .
1257 m->link_method(m, CHECK);
1258 }
1259 }
1260
1261 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1262 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1263 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1264 for (int i = 0; i < local_interfaces()->length(); ++i) {
1265 InstanceKlass* ik = local_interfaces()->at(i);
1266
1267 // Initialization is depth first search ie. we start with top of the inheritance tree
1268 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1269 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1270 if (ik->has_nonstatic_concrete_methods()) {
1271 ik->initialize_super_interfaces(CHECK);
1272 }
1273
1274 // Only initialize() interfaces that "declare" concrete methods.
1275 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1276 ik->initialize(CHECK);
1277 }
1278 }
1279 }
1280
1281 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1282 static InitializationErrorTable* _initialization_error_table;
1283
1284 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1285 // Create the same exception with a message indicating the thread name,
1286 // and the StackTraceElements.
1287 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1288 ResourceMark rm(current);
1289 if (init_error.is_null()) {
1290 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1291
1292 // We failed to create the new exception, most likely due to either out-of-memory or
1293 // a stackoverflow error. If the original exception was either of those then we save
1294 // the shared, pre-allocated, stackless, instance of that exception.
1295 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1296 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1297 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1298 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1299 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1300 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1301 } else {
1302 return;
1303 }
1304 }
1305
1306 MutexLocker ml(current, ClassInitError_lock);
1307 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1308 bool created;
1309 if (_initialization_error_table == nullptr) {
1310 _initialization_error_table = new (mtClass) InitializationErrorTable();
1311 }
1312 _initialization_error_table->put_if_absent(this, elem, &created);
1313 assert(created, "Initialization is single threaded");
1314 log_trace(class, init)("Initialization error added for class %s", external_name());
1315 }
1316
1317 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1318 MutexLocker ml(current, ClassInitError_lock);
1319 if (_initialization_error_table == nullptr) {
1320 return nullptr;
1321 }
1322 OopHandle* h = _initialization_error_table->get(this);
1323 return (h != nullptr) ? h->resolve() : nullptr;
1324 }
1325
1326 // Need to remove entries for unloaded classes.
1327 void InstanceKlass::clean_initialization_error_table() {
1328 struct InitErrorTableCleaner {
1329 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1330 if (!ik->is_loader_alive()) {
1331 h.release(Universe::vm_global());
1332 return true;
1333 } else {
1334 return false;
1335 }
1336 }
1337 };
1338
1339 assert_locked_or_safepoint(ClassInitError_lock);
1340 InitErrorTableCleaner cleaner;
1341 if (_initialization_error_table != nullptr) {
1342 _initialization_error_table->unlink(&cleaner);
1343 }
1344 }
1345
1346 void InstanceKlass::initialize_impl(TRAPS) {
1347 HandleMark hm(THREAD);
1348
1349 // Make sure klass is linked (verified) before initialization
1350 // A class could already be verified, since it has been reflected upon.
1351 link_class(CHECK);
1352
1353 DTRACE_CLASSINIT_PROBE(required, -1);
1354
1355 bool wait = false;
1356
1357 JavaThread* jt = THREAD;
1358
1359 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1360
1361 // refer to the JVM book page 47 for description of steps
1362 // Step 1
1363 {
1364 Handle h_init_lock(THREAD, init_lock());
1365 ObjectLocker ol(h_init_lock, jt);
1366
1367 // Step 2
1368 // If we were to use wait() instead of waitInterruptibly() then
1369 // we might end up throwing IE from link/symbol resolution sites
1370 // that aren't expected to throw. This would wreak havoc. See 6320309.
1371 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1372 if (debug_logging_enabled) {
1373 ResourceMark rm(jt);
1374 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1375 jt->name(), external_name(), init_thread_name());
1376 }
1377 wait = true;
1378 jt->set_class_to_be_initialized(this);
1379 ol.wait_uninterruptibly(jt);
1380 jt->set_class_to_be_initialized(nullptr);
1381 }
1382
1383 // Step 3
1384 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1385 if (debug_logging_enabled) {
1386 ResourceMark rm(jt);
1387 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1388 jt->name(), external_name());
1389 }
1390 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1391 return;
1392 }
1393
1394 // Step 4
1395 if (is_initialized()) {
1396 if (debug_logging_enabled) {
1397 ResourceMark rm(jt);
1398 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1399 jt->name(), external_name());
1400 }
1401 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1402 return;
1403 }
1404
1405 // Step 5
1406 if (is_in_error_state()) {
1407 if (debug_logging_enabled) {
1408 ResourceMark rm(jt);
1409 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1410 jt->name(), external_name());
1411 }
1412
1413 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1414 ResourceMark rm(THREAD);
1415 Handle cause(THREAD, get_initialization_error(THREAD));
1416
1417 stringStream ss;
1418 ss.print("Could not initialize class %s", external_name());
1419 if (cause.is_null()) {
1420 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1421 } else {
1422 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1423 ss.as_string(), cause);
1424 }
1425 } else {
1426
1427 // Step 6
1428 set_init_state(being_initialized);
1429 set_init_thread(jt);
1430 if (debug_logging_enabled) {
1431 ResourceMark rm(jt);
1432 log_debug(class, init)("Thread \"%s\" is initializing %s",
1433 jt->name(), external_name());
1434 }
1435 }
1436 }
1437
1438 // Pre-allocating an all-zero value to be used to reset nullable flat storages
1439 if (is_inline_klass()) {
1440 InlineKlass* vk = InlineKlass::cast(this);
1441 if (vk->has_nullable_atomic_layout()) {
1442 oop val = vk->allocate_instance(THREAD);
1443 if (HAS_PENDING_EXCEPTION) {
1444 Handle e(THREAD, PENDING_EXCEPTION);
1445 CLEAR_PENDING_EXCEPTION;
1446 {
1447 EXCEPTION_MARK;
1448 add_initialization_error(THREAD, e);
1449 // Locks object, set state, and notify all waiting threads
1450 set_initialization_state_and_notify(initialization_error, THREAD);
1451 CLEAR_PENDING_EXCEPTION;
1452 }
1453 THROW_OOP(e());
1454 }
1455 vk->set_null_reset_value(val);
1456 }
1457 }
1458
1459 // Step 7
1460 // Next, if C is a class rather than an interface, initialize it's super class and super
1461 // interfaces.
1462 if (!is_interface()) {
1463 Klass* super_klass = super();
1464 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1465 super_klass->initialize(THREAD);
1466 }
1467 // If C implements any interface that declares a non-static, concrete method,
1468 // the initialization of C triggers initialization of its super interfaces.
1469 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1470 // having a superinterface that declares, non-static, concrete methods
1471 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1472 initialize_super_interfaces(THREAD);
1473 }
1474
1475 // If any exceptions, complete abruptly, throwing the same exception as above.
1476 if (HAS_PENDING_EXCEPTION) {
1477 Handle e(THREAD, PENDING_EXCEPTION);
1478 CLEAR_PENDING_EXCEPTION;
1479 {
1480 EXCEPTION_MARK;
1481 add_initialization_error(THREAD, e);
1482 // Locks object, set state, and notify all waiting threads
1483 set_initialization_state_and_notify(initialization_error, THREAD);
1484 CLEAR_PENDING_EXCEPTION;
1485 }
1486 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1487 THROW_OOP(e());
1488 }
1489 }
1490
1491 // Step 8
1492 {
1493 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1494 if (class_initializer() != nullptr) {
1495 // Timer includes any side effects of class initialization (resolution,
1496 // etc), but not recursive entry into call_class_initializer().
1497 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1498 ClassLoader::perf_class_init_selftime(),
1499 ClassLoader::perf_classes_inited(),
1500 jt->get_thread_stat()->perf_recursion_counts_addr(),
1501 jt->get_thread_stat()->perf_timers_addr(),
1502 PerfClassTraceTime::CLASS_CLINIT);
1503 call_class_initializer(THREAD);
1504 } else {
1505 // The elapsed time is so small it's not worth counting.
1506 if (UsePerfData) {
1507 ClassLoader::perf_classes_inited()->inc();
1508 }
1509 call_class_initializer(THREAD);
1510 }
1511
1512 if (has_strict_static_fields() && !HAS_PENDING_EXCEPTION) {
1513 // Step 9 also verifies that strict static fields have been initialized.
1514 // Status bits were set in ClassFileParser::post_process_parsed_stream.
1515 // After <clinit>, bits must all be clear, or else we must throw an error.
1516 // This is an extremely fast check, so we won't bother with a timer.
1517 assert(fields_status() != nullptr, "");
1518 Symbol* bad_strict_static = nullptr;
1519 for (int index = 0; index < fields_status()->length(); index++) {
1520 // Very fast loop over single byte array looking for a set bit.
1521 if (fields_status()->adr_at(index)->is_strict_static_unset()) {
1522 // This strict static field has not been set by the class initializer.
1523 // Note that in the common no-error case, we read no field metadata.
1524 // We only unpack it when we need to report an error.
1525 FieldInfo fi = field(index);
1526 bad_strict_static = fi.name(constants());
1527 if (debug_logging_enabled) {
1528 ResourceMark rm(jt);
1529 const char* msg = format_strict_static_message(bad_strict_static);
1530 log_debug(class, init)("%s", msg);
1531 } else {
1532 // If we are not logging, do not bother to look for a second offense.
1533 break;
1534 }
1535 }
1536 }
1537 if (bad_strict_static != nullptr) {
1538 throw_strict_static_exception(bad_strict_static, "is unset after initialization of", THREAD);
1539 }
1540 }
1541 }
1542
1543 // Step 9
1544 if (!HAS_PENDING_EXCEPTION) {
1545 set_initialization_state_and_notify(fully_initialized, CHECK);
1546 debug_only(vtable().verify(tty, true);)
1547 }
1548 else {
1549 // Step 10 and 11
1550 Handle e(THREAD, PENDING_EXCEPTION);
1551 CLEAR_PENDING_EXCEPTION;
1552 // JVMTI has already reported the pending exception
1553 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1554 JvmtiExport::clear_detected_exception(jt);
1555 {
1556 EXCEPTION_MARK;
1557 add_initialization_error(THREAD, e);
1558 set_initialization_state_and_notify(initialization_error, THREAD);
1559 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1560 // JVMTI has already reported the pending exception
1561 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1562 JvmtiExport::clear_detected_exception(jt);
1563 }
1564 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1565 if (e->is_a(vmClasses::Error_klass())) {
1566 THROW_OOP(e());
1567 } else {
1568 JavaCallArguments args(e);
1569 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1570 vmSymbols::throwable_void_signature(),
1571 &args);
1572 }
1573 }
1574 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1575 }
1576
1577
1578 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1579 Handle h_init_lock(THREAD, init_lock());
1580 if (h_init_lock() != nullptr) {
1581 ObjectLocker ol(h_init_lock, THREAD);
1582 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1583 set_init_state(state);
1584 fence_and_clear_init_lock();
1585 ol.notify_all(CHECK);
1586 } else {
1587 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1588 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1589 set_init_state(state);
1590 }
1591 }
1592
1593 void InstanceKlass::notify_strict_static_access(int field_index, bool is_writing, TRAPS) {
1594 guarantee(field_index >= 0 && field_index < fields_status()->length(), "valid field index");
1595 DEBUG_ONLY(FieldInfo debugfi = field(field_index));
1596 assert(debugfi.access_flags().is_strict(), "");
1597 assert(debugfi.access_flags().is_static(), "");
1598 FieldStatus& fs = *fields_status()->adr_at(field_index);
1599 LogTarget(Trace, class, init) lt;
1600 if (lt.is_enabled()) {
1601 ResourceMark rm(THREAD);
1602 LogStream ls(lt);
1603 FieldInfo fi = field(field_index);
1604 ls.print("notify %s %s %s%s ",
1605 external_name(), is_writing? "Write" : "Read",
1606 fs.is_strict_static_unset() ? "Unset" : "(set)",
1607 fs.is_strict_static_unread() ? "+Unread" : "");
1608 fi.print(&ls, constants());
1609 }
1610 if (fs.is_strict_static_unset()) {
1611 assert(fs.is_strict_static_unread(), "ClassFileParser resp.");
1612 // If it is not set, there are only two reasonable things we can do here:
1613 // - mark it set if this is putstatic
1614 // - throw an error (Read-Before-Write) if this is getstatic
1615
1616 // The unset state is (or should be) transient, and observable only in one
1617 // thread during the execution of <clinit>. Something is wrong here as this
1618 // should not be possible
1619 guarantee(is_reentrant_initialization(THREAD), "unscoped access to strict static");
1620 if (is_writing) {
1621 // clear the "unset" bit, since the field is actually going to be written
1622 fs.update_strict_static_unset(false);
1623 } else {
1624 // throw an IllegalStateException, since we are reading before writing
1625 // see also InstanceKlass::initialize_impl, Step 8 (at end)
1626 Symbol* bad_strict_static = field(field_index).name(constants());
1627 throw_strict_static_exception(bad_strict_static, "is unset before first read in", CHECK);
1628 }
1629 } else {
1630 // Ensure no write after read for final strict statics
1631 FieldInfo fi = field(field_index);
1632 bool is_final = fi.access_flags().is_final();
1633 if (is_final) {
1634 // no final write after read, so observing a constant freezes it, as if <clinit> ended early
1635 // (maybe we could trust the constant a little earlier, before <clinit> ends)
1636 if (is_writing && !fs.is_strict_static_unread()) {
1637 Symbol* bad_strict_static = fi.name(constants());
1638 throw_strict_static_exception(bad_strict_static, "is set after read (as final) in", CHECK);
1639 } else if (!is_writing && fs.is_strict_static_unread()) {
1640 fs.update_strict_static_unread(false);
1641 }
1642 }
1643 }
1644 }
1645
1646 void InstanceKlass::throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS) {
1647 ResourceMark rm(THREAD);
1648 const char* msg = format_strict_static_message(field_name, when);
1649 THROW_MSG(vmSymbols::java_lang_IllegalStateException(), msg);
1650 }
1651
1652 const char* InstanceKlass::format_strict_static_message(Symbol* field_name, const char* when) {
1653 stringStream ss;
1654 ss.print("Strict static \"%s\" %s %s",
1655 field_name->as_C_string(),
1656 when == nullptr ? "is unset in" : when,
1657 external_name());
1658 return ss.as_string();
1659 }
1660
1661 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1662 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1663 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1664 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1665
1666 DeoptimizationScope deopt_scope;
1667 {
1668 MutexLocker ml(current, Compile_lock);
1669
1670 set_init_state(InstanceKlass::loaded);
1671 // make sure init_state store is already done.
1672 // The compiler reads the hierarchy outside of the Compile_lock.
1673 // Access ordering is used to add to hierarchy.
1674
1675 // Link into hierarchy.
1676 append_to_sibling_list(); // add to superklass/sibling list
1677 process_interfaces(); // handle all "implements" declarations
1678
1679 // Now mark all code that depended on old class hierarchy.
1680 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1681 if (Universe::is_fully_initialized()) {
1682 CodeCache::mark_dependents_on(&deopt_scope, this);
1683 }
1684 }
1685 // Perform the deopt handshake outside Compile_lock.
1686 deopt_scope.deoptimize_marked();
1687 }
1688
1689
1690 InstanceKlass* InstanceKlass::implementor() const {
1691 InstanceKlass* volatile* ik = adr_implementor();
1692 if (ik == nullptr) {
1693 return nullptr;
1694 } else {
1695 // This load races with inserts, and therefore needs acquire.
1696 InstanceKlass* ikls = Atomic::load_acquire(ik);
1697 if (ikls != nullptr && !ikls->is_loader_alive()) {
1698 return nullptr; // don't return unloaded class
1699 } else {
1700 return ikls;
1701 }
1702 }
1703 }
1704
1705
1706 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1707 assert_locked_or_safepoint(Compile_lock);
1708 assert(is_interface(), "not interface");
1709 InstanceKlass* volatile* addr = adr_implementor();
1710 assert(addr != nullptr, "null addr");
1711 if (addr != nullptr) {
1712 Atomic::release_store(addr, ik);
1713 }
1714 }
1715
1716 int InstanceKlass::nof_implementors() const {
1717 InstanceKlass* ik = implementor();
1718 if (ik == nullptr) {
1719 return 0;
1720 } else if (ik != this) {
1721 return 1;
1722 } else {
1723 return 2;
1724 }
1725 }
1726
1727 // The embedded _implementor field can only record one implementor.
1728 // When there are more than one implementors, the _implementor field
1729 // is set to the interface Klass* itself. Following are the possible
1730 // values for the _implementor field:
1731 // null - no implementor
1732 // implementor Klass* - one implementor
1733 // self - more than one implementor
1734 //
1735 // The _implementor field only exists for interfaces.
1736 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1737 if (Universe::is_fully_initialized()) {
1738 assert_lock_strong(Compile_lock);
1739 }
1740 assert(is_interface(), "not interface");
1741 // Filter out my subinterfaces.
1742 // (Note: Interfaces are never on the subklass list.)
1743 if (ik->is_interface()) return;
1744
1745 // Filter out subclasses whose supers already implement me.
1746 // (Note: CHA must walk subclasses of direct implementors
1747 // in order to locate indirect implementors.)
1748 InstanceKlass* super_ik = ik->java_super();
1749 if (super_ik != nullptr && super_ik->implements_interface(this))
1750 // We only need to check one immediate superclass, since the
1751 // implements_interface query looks at transitive_interfaces.
1752 // Any supers of the super have the same (or fewer) transitive_interfaces.
1753 return;
1754
1755 InstanceKlass* iklass = implementor();
1756 if (iklass == nullptr) {
1757 set_implementor(ik);
1758 } else if (iklass != this && iklass != ik) {
1759 // There is already an implementor. Use itself as an indicator of
1760 // more than one implementors.
1761 set_implementor(this);
1762 }
1763
1764 // The implementor also implements the transitive_interfaces
1765 for (int index = 0; index < local_interfaces()->length(); index++) {
1766 local_interfaces()->at(index)->add_implementor(ik);
1767 }
1768 }
1769
1770 void InstanceKlass::init_implementor() {
1771 if (is_interface()) {
1772 set_implementor(nullptr);
1773 }
1774 }
1775
1776
1777 void InstanceKlass::process_interfaces() {
1778 // link this class into the implementors list of every interface it implements
1779 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1780 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1781 InstanceKlass* interf = local_interfaces()->at(i);
1782 assert(interf->is_interface(), "expected interface");
1783 interf->add_implementor(this);
1784 }
1785 }
1786
1787 bool InstanceKlass::can_be_primary_super_slow() const {
1788 if (is_interface())
1789 return false;
1790 else
1791 return Klass::can_be_primary_super_slow();
1792 }
1793
1794 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1795 Array<InstanceKlass*>* transitive_interfaces) {
1796 // The secondaries are the implemented interfaces.
1797 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1798 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1799 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1800 int num_secondaries = num_extra_slots + interfaces->length();
1801 if (num_secondaries == 0) {
1802 // Must share this for correct bootstrapping!
1803 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1804 return nullptr;
1805 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1806 // We will reuse the transitive interfaces list if we're certain
1807 // it's in hash order.
1808 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1809 set_secondary_supers(interfaces, bitmap);
1810 return nullptr;
1811 }
1812 // Copy transitive interfaces to a temporary growable array to be constructed
1813 // into the secondary super list with extra slots.
1814 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1815 for (int i = 0; i < interfaces->length(); i++) {
1816 secondaries->push(interfaces->at(i));
1817 }
1818 return secondaries;
1819 }
1820
1821 bool InstanceKlass::implements_interface(Klass* k) const {
1822 if (this == k) return true;
1823 assert(k->is_interface(), "should be an interface class");
1824 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1825 if (transitive_interfaces()->at(i) == k) {
1826 return true;
1827 }
1828 }
1829 return false;
1830 }
1831
1832 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1833 // Verify direct super interface
1834 if (this == k) return true;
1835 assert(k->is_interface(), "should be an interface class");
1836 for (int i = 0; i < local_interfaces()->length(); i++) {
1837 if (local_interfaces()->at(i) == k) {
1838 return true;
1839 }
1840 }
1841 return false;
1842 }
1843
1844 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1845 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1846 size_t size = objArrayOopDesc::object_size(length);
1847 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1848 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1849 /* do_zero */ true, CHECK_NULL);
1850 return o;
1851 }
1852
1853 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1854 if (TraceFinalizerRegistration) {
1855 tty->print("Registered ");
1856 i->print_value_on(tty);
1857 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1858 }
1859 instanceHandle h_i(THREAD, i);
1860 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1861 JavaValue result(T_VOID);
1862 JavaCallArguments args(h_i);
1863 methodHandle mh(THREAD, Universe::finalizer_register_method());
1864 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1865 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1866 return h_i();
1867 }
1868
1869 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1870 assert(!is_abstract() && !is_interface(), "Should not create this object");
1871 size_t size = size_helper(); // Query before forming handle.
1872 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1873 }
1874
1875 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1876 Klass* k = java_lang_Class::as_Klass(java_class);
1877 if (k == nullptr) {
1878 ResourceMark rm(THREAD);
1879 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1880 }
1881 InstanceKlass* ik = cast(k);
1882 ik->check_valid_for_instantiation(false, CHECK_NULL);
1883 ik->initialize(CHECK_NULL);
1884 return ik->allocate_instance(THREAD);
1885 }
1886
1887 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1888 return instanceHandle(THREAD, allocate_instance(THREAD));
1889 }
1890
1891 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1892 if (is_interface() || is_abstract()) {
1893 ResourceMark rm(THREAD);
1894 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1895 : vmSymbols::java_lang_InstantiationException(), external_name());
1896 }
1897 if (this == vmClasses::Class_klass()) {
1898 ResourceMark rm(THREAD);
1899 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1900 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1901 }
1902 }
1903
1904 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1905 // Need load-acquire for lock-free read
1906 if (array_klasses_acquire() == nullptr) {
1907
1908 // Recursively lock array allocation
1909 RecursiveLocker rl(MultiArray_lock, THREAD);
1910
1911 // Check if another thread created the array klass while we were waiting for the lock.
1912 if (array_klasses() == nullptr) {
1913 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, false, CHECK_NULL);
1914 // use 'release' to pair with lock-free load
1915 release_set_array_klasses(k);
1916 }
1917 }
1918
1919 // array_klasses() will always be set at this point
1920 ArrayKlass* ak = array_klasses();
1921 assert(ak != nullptr, "should be set");
1922 return ak->array_klass(n, THREAD);
1923 }
1924
1925 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1926 // Need load-acquire for lock-free read
1927 ArrayKlass* ak = array_klasses_acquire();
1928 if (ak == nullptr) {
1929 return nullptr;
1930 } else {
1931 return ak->array_klass_or_null(n);
1932 }
1933 }
1934
1935 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1936 return array_klass(1, THREAD);
1937 }
1938
1939 ArrayKlass* InstanceKlass::array_klass_or_null() {
1940 return array_klass_or_null(1);
1941 }
1942
1943 static int call_class_initializer_counter = 0; // for debugging
1944
1945 Method* InstanceKlass::class_initializer() const {
1946 Method* clinit = find_method(
1947 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1948 if (clinit != nullptr && clinit->is_class_initializer()) {
1949 return clinit;
1950 }
1951 return nullptr;
1952 }
1953
1954 void InstanceKlass::call_class_initializer(TRAPS) {
1955 if (ReplayCompiles &&
1956 (ReplaySuppressInitializers == 1 ||
1957 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1958 // Hide the existence of the initializer for the purpose of replaying the compile
1959 return;
1960 }
1961
1962 #if INCLUDE_CDS
1963 // This is needed to ensure the consistency of the archived heap objects.
1964 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1965 AOTClassInitializer::call_runtime_setup(THREAD, this);
1966 return;
1967 } else if (has_archived_enum_objs()) {
1968 assert(is_shared(), "must be");
1969 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1970 if (initialized) {
1971 return;
1972 }
1973 }
1974 #endif
1975
1976 methodHandle h_method(THREAD, class_initializer());
1977 assert(!is_initialized(), "we cannot initialize twice");
1978 LogTarget(Info, class, init) lt;
1979 if (lt.is_enabled()) {
1980 ResourceMark rm(THREAD);
1981 LogStream ls(lt);
1982 ls.print("%d Initializing ", call_class_initializer_counter++);
1983 name()->print_value_on(&ls);
1984 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1985 h_method() == nullptr ? "(no method)" : "", p2i(this),
1986 THREAD->name());
1987 }
1988 if (h_method() != nullptr) {
1989 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1990 JavaCallArguments args; // No arguments
1991 JavaValue result(T_VOID);
1992 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1993 }
1994 }
1995
1996 // If a class that implements this interface is initialized, is the JVM required
1997 // to first execute a <clinit> method declared in this interface,
1998 // or (if also_check_supers==true) any of the super types of this interface?
1999 //
2000 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
2001 // an interface, then let SC be its superclass and let SI1, ..., SIn
2002 // be all superinterfaces of C (whether direct or indirect) that
2003 // declare at least one non-abstract, non-static method.
2004 //
2005 // So when an interface is initialized, it does not look at its
2006 // supers. But a proper class will ensure that all of its supers have
2007 // run their <clinit> methods, except that it disregards interfaces
2008 // that lack a non-static concrete method (i.e., a default method).
2009 // Therefore, you should probably call this method only when the
2010 // current class is a super of some proper class, not an interface.
2011 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
2012 assert(is_interface(), "must be");
2013
2014 if (!has_nonstatic_concrete_methods()) {
2015 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
2016 return false;
2017 }
2018
2019 // JVMS 5.5. Initialization
2020 // ...If C is an interface that declares a non-abstract,
2021 // non-static method, the initialization of a class that
2022 // implements C directly or indirectly.
2023 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
2024 return true;
2025 }
2026 if (also_check_supers) {
2027 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2028 for (int i = 0; i < all_ifs->length(); ++i) {
2029 InstanceKlass* super_intf = all_ifs->at(i);
2030 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
2031 return true;
2032 }
2033 }
2034 }
2035 return false;
2036 }
2037
2038 void InstanceKlass::mask_for(const methodHandle& method, int bci,
2039 InterpreterOopMap* entry_for) {
2040 // Lazily create the _oop_map_cache at first request.
2041 // Load_acquire is needed to safely get instance published with CAS by another thread.
2042 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
2043 if (oop_map_cache == nullptr) {
2044 // Try to install new instance atomically.
2045 oop_map_cache = new OopMapCache();
2046 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
2047 if (other != nullptr) {
2048 // Someone else managed to install before us, ditch local copy and use the existing one.
2049 delete oop_map_cache;
2050 oop_map_cache = other;
2051 }
2052 }
2053 // _oop_map_cache is constant after init; lookup below does its own locking.
2054 oop_map_cache->lookup(method, bci, entry_for);
2055 }
2056
2057
2058 FieldInfo InstanceKlass::field(int index) const {
2059 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2060 if (fs.index() == index) {
2061 return fs.to_FieldInfo();
2062 }
2063 }
2064 fatal("Field not found");
2065 return FieldInfo();
2066 }
2067
2068 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2069 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2070 Symbol* f_name = fs.name();
2071 Symbol* f_sig = fs.signature();
2072 if (f_name == name && f_sig == sig) {
2073 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2074 return true;
2075 }
2076 }
2077 return false;
2078 }
2079
2080
2081 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2082 const int n = local_interfaces()->length();
2083 for (int i = 0; i < n; i++) {
2084 Klass* intf1 = local_interfaces()->at(i);
2085 assert(intf1->is_interface(), "just checking type");
2086 // search for field in current interface
2087 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
2088 assert(fd->is_static(), "interface field must be static");
2089 return intf1;
2090 }
2091 // search for field in direct superinterfaces
2092 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
2093 if (intf2 != nullptr) return intf2;
2094 }
2095 // otherwise field lookup fails
2096 return nullptr;
2097 }
2098
2099
2100 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2101 // search order according to newest JVM spec (5.4.3.2, p.167).
2102 // 1) search for field in current klass
2103 if (find_local_field(name, sig, fd)) {
2104 return const_cast<InstanceKlass*>(this);
2105 }
2106 // 2) search for field recursively in direct superinterfaces
2107 { Klass* intf = find_interface_field(name, sig, fd);
2108 if (intf != nullptr) return intf;
2109 }
2110 // 3) apply field lookup recursively if superclass exists
2111 { Klass* supr = super();
2112 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
2113 }
2114 // 4) otherwise field lookup fails
2115 return nullptr;
2116 }
2117
2118
2119 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
2120 // search order according to newest JVM spec (5.4.3.2, p.167).
2121 // 1) search for field in current klass
2122 if (find_local_field(name, sig, fd)) {
2123 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
2124 }
2125 // 2) search for field recursively in direct superinterfaces
2126 if (is_static) {
2127 Klass* intf = find_interface_field(name, sig, fd);
2128 if (intf != nullptr) return intf;
2129 }
2130 // 3) apply field lookup recursively if superclass exists
2131 { Klass* supr = super();
2132 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
2133 }
2134 // 4) otherwise field lookup fails
2135 return nullptr;
2136 }
2137
2138 bool InstanceKlass::contains_field_offset(int offset) {
2139 if (this->is_inline_klass()) {
2140 InlineKlass* vk = InlineKlass::cast(this);
2141 return offset >= vk->payload_offset() && offset < (vk->payload_offset() + vk->payload_size_in_bytes());
2142 } else {
2143 fieldDescriptor fd;
2144 return find_field_from_offset(offset, false, &fd);
2145 }
2146 }
2147
2148 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2149 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2150 if (fs.offset() == offset) {
2151 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2152 if (fd->is_static() == is_static) return true;
2153 }
2154 }
2155 return false;
2156 }
2157
2158
2159 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2160 Klass* klass = const_cast<InstanceKlass*>(this);
2161 while (klass != nullptr) {
2162 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
2163 return true;
2164 }
2165 klass = klass->super();
2166 }
2167 return false;
2168 }
2169
2170
2171 void InstanceKlass::methods_do(void f(Method* method)) {
2172 // Methods aren't stable until they are loaded. This can be read outside
2173 // a lock through the ClassLoaderData for profiling
2174 // Redefined scratch classes are on the list and need to be cleaned
2175 if (!is_loaded() && !is_scratch_class()) {
2176 return;
2177 }
2178
2179 int len = methods()->length();
2180 for (int index = 0; index < len; index++) {
2181 Method* m = methods()->at(index);
2182 assert(m->is_method(), "must be method");
2183 f(m);
2184 }
2185 }
2186
2187
2188 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
2189 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2190 if (fs.access_flags().is_static()) {
2191 fieldDescriptor& fd = fs.field_descriptor();
2192 cl->do_field(&fd);
2193 }
2194 }
2195 }
2196
2197
2198 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
2199 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2200 if (fs.access_flags().is_static()) {
2201 fieldDescriptor& fd = fs.field_descriptor();
2202 f(&fd, mirror, CHECK);
2203 }
2204 }
2205 }
2206
2207 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
2208 InstanceKlass* super = superklass();
2209 if (super != nullptr) {
2210 super->do_nonstatic_fields(cl);
2211 }
2212 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2213 fieldDescriptor& fd = fs.field_descriptor();
2214 if (!fd.is_static()) {
2215 cl->do_field(&fd);
2216 }
2217 }
2218 }
2219
2220 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
2221 return a->offset() - b->offset();
2222 }
2223
2224 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
2225 InstanceKlass* super = superklass();
2226 if (super != nullptr) {
2227 super->print_nonstatic_fields(cl);
2228 }
2229 ResourceMark rm;
2230 // In DebugInfo nonstatic fields are sorted by offset.
2231 GrowableArray<FieldInfo> fields_sorted;
2232 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2233 if (!fs.access_flags().is_static()) {
2234 fields_sorted.push(fs.to_FieldInfo());
2235 }
2236 }
2237 int length = fields_sorted.length();
2238 if (length > 0) {
2239 fields_sorted.sort(compare_fields_by_offset);
2240 fieldDescriptor fd;
2241 for (int i = 0; i < length; i++) {
2242 fd.reinitialize(this, fields_sorted.at(i));
2243 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
2244 cl->do_field(&fd);
2245 }
2246 }
2247 }
2248
2249 #ifdef ASSERT
2250 static int linear_search(const Array<Method*>* methods,
2251 const Symbol* name,
2252 const Symbol* signature) {
2253 const int len = methods->length();
2254 for (int index = 0; index < len; index++) {
2255 const Method* const m = methods->at(index);
2256 assert(m->is_method(), "must be method");
2257 if (m->signature() == signature && m->name() == name) {
2258 return index;
2259 }
2260 }
2261 return -1;
2262 }
2263 #endif
2264
2265 bool InstanceKlass::_disable_method_binary_search = false;
2266
2267 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2268 int len = methods->length();
2269 int l = 0;
2270 int h = len - 1;
2271 while (l <= h) {
2272 Method* m = methods->at(l);
2273 if (m->name() == name) {
2274 return l;
2275 }
2276 l++;
2277 }
2278 return -1;
2279 }
2280
2281 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2282 if (_disable_method_binary_search) {
2283 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2284 // At the final stage of dynamic dumping, the methods array may not be sorted
2285 // by ascending addresses of their names, so we can't use binary search anymore.
2286 // However, methods with the same name are still laid out consecutively inside the
2287 // methods array, so let's look for the first one that matches.
2288 return linear_search(methods, name);
2289 }
2290
2291 int len = methods->length();
2292 int l = 0;
2293 int h = len - 1;
2294
2295 // methods are sorted by ascending addresses of their names, so do binary search
2296 while (l <= h) {
2297 int mid = (l + h) >> 1;
2298 Method* m = methods->at(mid);
2299 assert(m->is_method(), "must be method");
2300 int res = m->name()->fast_compare(name);
2301 if (res == 0) {
2302 return mid;
2303 } else if (res < 0) {
2304 l = mid + 1;
2305 } else {
2306 h = mid - 1;
2307 }
2308 }
2309 return -1;
2310 }
2311
2312 // find_method looks up the name/signature in the local methods array
2313 Method* InstanceKlass::find_method(const Symbol* name,
2314 const Symbol* signature) const {
2315 return find_method_impl(name, signature,
2316 OverpassLookupMode::find,
2317 StaticLookupMode::find,
2318 PrivateLookupMode::find);
2319 }
2320
2321 Method* InstanceKlass::find_method_impl(const Symbol* name,
2322 const Symbol* signature,
2323 OverpassLookupMode overpass_mode,
2324 StaticLookupMode static_mode,
2325 PrivateLookupMode private_mode) const {
2326 return InstanceKlass::find_method_impl(methods(),
2327 name,
2328 signature,
2329 overpass_mode,
2330 static_mode,
2331 private_mode);
2332 }
2333
2334 // find_instance_method looks up the name/signature in the local methods array
2335 // and skips over static methods
2336 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2337 const Symbol* name,
2338 const Symbol* signature,
2339 PrivateLookupMode private_mode) {
2340 Method* const meth = InstanceKlass::find_method_impl(methods,
2341 name,
2342 signature,
2343 OverpassLookupMode::find,
2344 StaticLookupMode::skip,
2345 private_mode);
2346 assert(((meth == nullptr) || !meth->is_static()),
2347 "find_instance_method should have skipped statics");
2348 return meth;
2349 }
2350
2351 // find_instance_method looks up the name/signature in the local methods array
2352 // and skips over static methods
2353 Method* InstanceKlass::find_instance_method(const Symbol* name,
2354 const Symbol* signature,
2355 PrivateLookupMode private_mode) const {
2356 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2357 }
2358
2359 // Find looks up the name/signature in the local methods array
2360 // and filters on the overpass, static and private flags
2361 // This returns the first one found
2362 // note that the local methods array can have up to one overpass, one static
2363 // and one instance (private or not) with the same name/signature
2364 Method* InstanceKlass::find_local_method(const Symbol* name,
2365 const Symbol* signature,
2366 OverpassLookupMode overpass_mode,
2367 StaticLookupMode static_mode,
2368 PrivateLookupMode private_mode) const {
2369 return InstanceKlass::find_method_impl(methods(),
2370 name,
2371 signature,
2372 overpass_mode,
2373 static_mode,
2374 private_mode);
2375 }
2376
2377 // Find looks up the name/signature in the local methods array
2378 // and filters on the overpass, static and private flags
2379 // This returns the first one found
2380 // note that the local methods array can have up to one overpass, one static
2381 // and one instance (private or not) with the same name/signature
2382 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2383 const Symbol* name,
2384 const Symbol* signature,
2385 OverpassLookupMode overpass_mode,
2386 StaticLookupMode static_mode,
2387 PrivateLookupMode private_mode) {
2388 return InstanceKlass::find_method_impl(methods,
2389 name,
2390 signature,
2391 overpass_mode,
2392 static_mode,
2393 private_mode);
2394 }
2395
2396 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2397 const Symbol* name,
2398 const Symbol* signature) {
2399 return InstanceKlass::find_method_impl(methods,
2400 name,
2401 signature,
2402 OverpassLookupMode::find,
2403 StaticLookupMode::find,
2404 PrivateLookupMode::find);
2405 }
2406
2407 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2408 const Symbol* name,
2409 const Symbol* signature,
2410 OverpassLookupMode overpass_mode,
2411 StaticLookupMode static_mode,
2412 PrivateLookupMode private_mode) {
2413 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2414 return hit >= 0 ? methods->at(hit): nullptr;
2415 }
2416
2417 // true if method matches signature and conforms to skipping_X conditions.
2418 static bool method_matches(const Method* m,
2419 const Symbol* signature,
2420 bool skipping_overpass,
2421 bool skipping_static,
2422 bool skipping_private) {
2423 return ((m->signature() == signature) &&
2424 (!skipping_overpass || !m->is_overpass()) &&
2425 (!skipping_static || !m->is_static()) &&
2426 (!skipping_private || !m->is_private()));
2427 }
2428
2429 // Used directly for default_methods to find the index into the
2430 // default_vtable_indices, and indirectly by find_method
2431 // find_method_index looks in the local methods array to return the index
2432 // of the matching name/signature. If, overpass methods are being ignored,
2433 // the search continues to find a potential non-overpass match. This capability
2434 // is important during method resolution to prefer a static method, for example,
2435 // over an overpass method.
2436 // There is the possibility in any _method's array to have the same name/signature
2437 // for a static method, an overpass method and a local instance method
2438 // To correctly catch a given method, the search criteria may need
2439 // to explicitly skip the other two. For local instance methods, it
2440 // is often necessary to skip private methods
2441 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2442 const Symbol* name,
2443 const Symbol* signature,
2444 OverpassLookupMode overpass_mode,
2445 StaticLookupMode static_mode,
2446 PrivateLookupMode private_mode) {
2447 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2448 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2449 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2450 const int hit = quick_search(methods, name);
2451 if (hit != -1) {
2452 const Method* const m = methods->at(hit);
2453
2454 // Do linear search to find matching signature. First, quick check
2455 // for common case, ignoring overpasses if requested.
2456 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2457 return hit;
2458 }
2459
2460 // search downwards through overloaded methods
2461 int i;
2462 for (i = hit - 1; i >= 0; --i) {
2463 const Method* const m = methods->at(i);
2464 assert(m->is_method(), "must be method");
2465 if (m->name() != name) {
2466 break;
2467 }
2468 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2469 return i;
2470 }
2471 }
2472 // search upwards
2473 for (i = hit + 1; i < methods->length(); ++i) {
2474 const Method* const m = methods->at(i);
2475 assert(m->is_method(), "must be method");
2476 if (m->name() != name) {
2477 break;
2478 }
2479 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2480 return i;
2481 }
2482 }
2483 // not found
2484 #ifdef ASSERT
2485 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2486 linear_search(methods, name, signature);
2487 assert(-1 == index, "binary search should have found entry %d", index);
2488 #endif
2489 }
2490 return -1;
2491 }
2492
2493 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2494 return find_method_by_name(methods(), name, end);
2495 }
2496
2497 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2498 const Symbol* name,
2499 int* end_ptr) {
2500 assert(end_ptr != nullptr, "just checking");
2501 int start = quick_search(methods, name);
2502 int end = start + 1;
2503 if (start != -1) {
2504 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2505 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2506 *end_ptr = end;
2507 return start;
2508 }
2509 return -1;
2510 }
2511
2512 // uncached_lookup_method searches both the local class methods array and all
2513 // superclasses methods arrays, skipping any overpass methods in superclasses,
2514 // and possibly skipping private methods.
2515 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2516 const Symbol* signature,
2517 OverpassLookupMode overpass_mode,
2518 PrivateLookupMode private_mode) const {
2519 OverpassLookupMode overpass_local_mode = overpass_mode;
2520 const Klass* klass = this;
2521 while (klass != nullptr) {
2522 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2523 signature,
2524 overpass_local_mode,
2525 StaticLookupMode::find,
2526 private_mode);
2527 if (method != nullptr) {
2528 return method;
2529 }
2530 if (name == vmSymbols::object_initializer_name()) {
2531 break; // <init> is never inherited
2532 }
2533 klass = klass->super();
2534 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2535 }
2536 return nullptr;
2537 }
2538
2539 #ifdef ASSERT
2540 // search through class hierarchy and return true if this class or
2541 // one of the superclasses was redefined
2542 bool InstanceKlass::has_redefined_this_or_super() const {
2543 const Klass* klass = this;
2544 while (klass != nullptr) {
2545 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2546 return true;
2547 }
2548 klass = klass->super();
2549 }
2550 return false;
2551 }
2552 #endif
2553
2554 // lookup a method in the default methods list then in all transitive interfaces
2555 // Do NOT return private or static methods
2556 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2557 Symbol* signature) const {
2558 Method* m = nullptr;
2559 if (default_methods() != nullptr) {
2560 m = find_method(default_methods(), name, signature);
2561 }
2562 // Look up interfaces
2563 if (m == nullptr) {
2564 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2565 }
2566 return m;
2567 }
2568
2569 // lookup a method in all the interfaces that this class implements
2570 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2571 // They should only be found in the initial InterfaceMethodRef
2572 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2573 Symbol* signature,
2574 DefaultsLookupMode defaults_mode) const {
2575 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2576 int num_ifs = all_ifs->length();
2577 InstanceKlass *ik = nullptr;
2578 for (int i = 0; i < num_ifs; i++) {
2579 ik = all_ifs->at(i);
2580 Method* m = ik->lookup_method(name, signature);
2581 if (m != nullptr && m->is_public() && !m->is_static() &&
2582 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2583 return m;
2584 }
2585 }
2586 return nullptr;
2587 }
2588
2589 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2590 :_st(st), _verbose(verbose) {
2591 ResourceMark rm;
2592 _st->print("%-18s ", "KlassAddr");
2593 _st->print("%-4s ", "Size");
2594 _st->print("%-20s ", "State");
2595 _st->print("%-7s ", "Flags");
2596 _st->print("%-5s ", "ClassName");
2597 _st->cr();
2598 }
2599
2600 void PrintClassClosure::do_klass(Klass* k) {
2601 ResourceMark rm;
2602 // klass pointer
2603 _st->print(PTR_FORMAT " ", p2i(k));
2604 // klass size
2605 _st->print("%4d ", k->size());
2606 // initialization state
2607 if (k->is_instance_klass()) {
2608 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2609 } else {
2610 _st->print("%-20s ","");
2611 }
2612 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2613 char buf[10];
2614 int i = 0;
2615 if (k->has_finalizer()) buf[i++] = 'F';
2616 if (k->is_instance_klass()) {
2617 InstanceKlass* ik = InstanceKlass::cast(k);
2618 if (ik->has_final_method()) buf[i++] = 'f';
2619 if (ik->is_rewritten()) buf[i++] = 'W';
2620 if (ik->is_contended()) buf[i++] = 'C';
2621 if (ik->has_been_redefined()) buf[i++] = 'R';
2622 if (ik->is_shared()) buf[i++] = 'S';
2623 }
2624 buf[i++] = '\0';
2625 _st->print("%-7s ", buf);
2626 // klass name
2627 _st->print("%-5s ", k->external_name());
2628 // end
2629 _st->cr();
2630 if (_verbose) {
2631 k->print_on(_st);
2632 }
2633 }
2634
2635 /* jni_id_for for jfieldIds only */
2636 JNIid* InstanceKlass::jni_id_for(int offset) {
2637 MutexLocker ml(JfieldIdCreation_lock);
2638 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2639 if (probe == nullptr) {
2640 // Allocate new static field identifier
2641 probe = new JNIid(this, offset, jni_ids());
2642 set_jni_ids(probe);
2643 }
2644 return probe;
2645 }
2646
2647 u2 InstanceKlass::enclosing_method_data(int offset) const {
2648 const Array<jushort>* const inner_class_list = inner_classes();
2649 if (inner_class_list == nullptr) {
2650 return 0;
2651 }
2652 const int length = inner_class_list->length();
2653 if (length % inner_class_next_offset == 0) {
2654 return 0;
2655 }
2656 const int index = length - enclosing_method_attribute_size;
2657 assert(offset < enclosing_method_attribute_size, "invalid offset");
2658 return inner_class_list->at(index + offset);
2659 }
2660
2661 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2662 u2 method_index) {
2663 Array<jushort>* inner_class_list = inner_classes();
2664 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2665 int length = inner_class_list->length();
2666 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2667 int index = length - enclosing_method_attribute_size;
2668 inner_class_list->at_put(
2669 index + enclosing_method_class_index_offset, class_index);
2670 inner_class_list->at_put(
2671 index + enclosing_method_method_index_offset, method_index);
2672 }
2673 }
2674
2675 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2676 if (method->is_old() && !method->is_obsolete()) {
2677 // If the method passed in is old (but not obsolete), use the current version.
2678 method = method_with_idnum((int)idnum);
2679 assert(method != nullptr, "old and but not obsolete, so should exist");
2680 }
2681 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2682 Atomic::release_store(&jmeths[idnum + 1], new_id);
2683 return new_id;
2684 }
2685
2686 // Lookup or create a jmethodID.
2687 // This code is called by the VMThread and JavaThreads so the
2688 // locking has to be done very carefully to avoid deadlocks
2689 // and/or other cache consistency problems.
2690 //
2691 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2692 Method* method = method_h();
2693 int idnum = method->method_idnum();
2694 jmethodID* jmeths = methods_jmethod_ids_acquire();
2695
2696 // We use a double-check locking idiom here because this cache is
2697 // performance sensitive. In the normal system, this cache only
2698 // transitions from null to non-null which is safe because we use
2699 // release_set_methods_jmethod_ids() to advertise the new cache.
2700 // A partially constructed cache should never be seen by a racing
2701 // thread. We also use release_store() to save a new jmethodID
2702 // in the cache so a partially constructed jmethodID should never be
2703 // seen either. Cache reads of existing jmethodIDs proceed without a
2704 // lock, but cache writes of a new jmethodID requires uniqueness and
2705 // creation of the cache itself requires no leaks so a lock is
2706 // acquired in those two cases.
2707 //
2708 // If the RedefineClasses() API has been used, then this cache grows
2709 // in the redefinition safepoint.
2710
2711 if (jmeths == nullptr) {
2712 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2713 jmeths = methods_jmethod_ids_acquire();
2714 // Still null?
2715 if (jmeths == nullptr) {
2716 size_t size = idnum_allocated_count();
2717 assert(size > (size_t)idnum, "should already have space");
2718 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2719 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2720 // cache size is stored in element[0], other elements offset by one
2721 jmeths[0] = (jmethodID)size;
2722 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2723
2724 // publish jmeths
2725 release_set_methods_jmethod_ids(jmeths);
2726 return new_id;
2727 }
2728 }
2729
2730 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2731 if (id == nullptr) {
2732 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2733 id = jmeths[idnum + 1];
2734 // Still null?
2735 if (id == nullptr) {
2736 return update_jmethod_id(jmeths, method, idnum);
2737 }
2738 }
2739 return id;
2740 }
2741
2742 void InstanceKlass::update_methods_jmethod_cache() {
2743 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2744 jmethodID* cache = _methods_jmethod_ids;
2745 if (cache != nullptr) {
2746 size_t size = idnum_allocated_count();
2747 size_t old_size = (size_t)cache[0];
2748 if (old_size < size + 1) {
2749 // Allocate a larger one and copy entries to the new one.
2750 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2751 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2752 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2753 // The cache size is stored in element[0]; the other elements are offset by one.
2754 new_cache[0] = (jmethodID)size;
2755
2756 for (int i = 1; i <= (int)old_size; i++) {
2757 new_cache[i] = cache[i];
2758 }
2759 _methods_jmethod_ids = new_cache;
2760 FREE_C_HEAP_ARRAY(jmethodID, cache);
2761 }
2762 }
2763 }
2764
2765 // Figure out how many jmethodIDs haven't been allocated, and make
2766 // sure space for them is pre-allocated. This makes getting all
2767 // method ids much, much faster with classes with more than 8
2768 // methods, and has a *substantial* effect on performance with jvmti
2769 // code that loads all jmethodIDs for all classes.
2770 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2771 int new_jmeths = 0;
2772 int length = methods()->length();
2773 for (int index = start_offset; index < length; index++) {
2774 Method* m = methods()->at(index);
2775 jmethodID id = m->find_jmethod_id_or_null();
2776 if (id == nullptr) {
2777 new_jmeths++;
2778 }
2779 }
2780 if (new_jmeths != 0) {
2781 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2782 }
2783 }
2784
2785 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2786 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2787 int idnum = method->method_idnum();
2788 jmethodID* jmeths = methods_jmethod_ids_acquire();
2789 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2790 }
2791
2792 inline DependencyContext InstanceKlass::dependencies() {
2793 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2794 return dep_context;
2795 }
2796
2797 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2798 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2799 }
2800
2801 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2802 dependencies().add_dependent_nmethod(nm);
2803 }
2804
2805 void InstanceKlass::clean_dependency_context() {
2806 dependencies().clean_unloading_dependents();
2807 }
2808
2809 #ifndef PRODUCT
2810 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2811 dependencies().print_dependent_nmethods(verbose);
2812 }
2813
2814 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2815 return dependencies().is_dependent_nmethod(nm);
2816 }
2817 #endif //PRODUCT
2818
2819 void InstanceKlass::clean_weak_instanceklass_links() {
2820 clean_implementors_list();
2821 clean_method_data();
2822 }
2823
2824 void InstanceKlass::clean_implementors_list() {
2825 assert(is_loader_alive(), "this klass should be live");
2826 if (is_interface()) {
2827 assert (ClassUnloading, "only called for ClassUnloading");
2828 for (;;) {
2829 // Use load_acquire due to competing with inserts
2830 InstanceKlass* volatile* iklass = adr_implementor();
2831 assert(iklass != nullptr, "Klass must not be null");
2832 InstanceKlass* impl = Atomic::load_acquire(iklass);
2833 if (impl != nullptr && !impl->is_loader_alive()) {
2834 // null this field, might be an unloaded instance klass or null
2835 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2836 // Successfully unlinking implementor.
2837 if (log_is_enabled(Trace, class, unload)) {
2838 ResourceMark rm;
2839 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2840 }
2841 return;
2842 }
2843 } else {
2844 return;
2845 }
2846 }
2847 }
2848 }
2849
2850 void InstanceKlass::clean_method_data() {
2851 for (int m = 0; m < methods()->length(); m++) {
2852 MethodData* mdo = methods()->at(m)->method_data();
2853 if (mdo != nullptr) {
2854 mdo->clean_method_data(/*always_clean*/false);
2855 }
2856 }
2857 }
2858
2859 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2860 Klass::metaspace_pointers_do(it);
2861
2862 if (log_is_enabled(Trace, cds)) {
2863 ResourceMark rm;
2864 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2865 }
2866
2867 it->push(&_annotations);
2868 it->push((Klass**)&_array_klasses);
2869 if (!is_rewritten()) {
2870 it->push(&_constants, MetaspaceClosure::_writable);
2871 } else {
2872 it->push(&_constants);
2873 }
2874 it->push(&_inner_classes);
2875 #if INCLUDE_JVMTI
2876 it->push(&_previous_versions);
2877 #endif
2878 #if INCLUDE_CDS
2879 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2880 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2881 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2882 // The length check on the _methods is necessary because classes which don't have any
2883 // methods share the Universe::_the_empty_method_array which is in the RO region.
2884 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2885 // To handle jsr bytecode, new Method* maybe stored into _methods
2886 it->push(&_methods, MetaspaceClosure::_writable);
2887 } else {
2888 #endif
2889 it->push(&_methods);
2890 #if INCLUDE_CDS
2891 }
2892 #endif
2893 it->push(&_default_methods);
2894 it->push(&_local_interfaces);
2895 it->push(&_transitive_interfaces);
2896 it->push(&_method_ordering);
2897 if (!is_rewritten()) {
2898 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2899 } else {
2900 it->push(&_default_vtable_indices);
2901 }
2902
2903 it->push(&_fieldinfo_stream);
2904 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2905 it->push(&_fields_status, MetaspaceClosure::_writable);
2906
2907 if (itable_length() > 0) {
2908 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2909 int method_table_offset_in_words = ioe->offset()/wordSize;
2910 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2911
2912 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2913 / itableOffsetEntry::size();
2914
2915 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2916 if (ioe->interface_klass() != nullptr) {
2917 it->push(ioe->interface_klass_addr());
2918 itableMethodEntry* ime = ioe->first_method_entry(this);
2919 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2920 for (int index = 0; index < n; index ++) {
2921 it->push(ime[index].method_addr());
2922 }
2923 }
2924 }
2925 }
2926
2927 it->push(&_nest_host);
2928 it->push(&_nest_members);
2929 it->push(&_permitted_subclasses);
2930 it->push(&_loadable_descriptors);
2931 it->push(&_record_components);
2932 it->push(&_inline_layout_info_array, MetaspaceClosure::_writable);
2933 }
2934
2935 #if INCLUDE_CDS
2936 void InstanceKlass::remove_unshareable_info() {
2937
2938 if (is_linked()) {
2939 assert(can_be_verified_at_dumptime(), "must be");
2940 // Remember this so we can avoid walking the hierarchy at runtime.
2941 set_verified_at_dump_time();
2942 }
2943
2944 Klass::remove_unshareable_info();
2945
2946 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2947 // Classes are attempted to link during dumping and may fail,
2948 // but these classes are still in the dictionary and class list in CLD.
2949 // If the class has failed verification, there is nothing else to remove.
2950 return;
2951 }
2952
2953 // Reset to the 'allocated' state to prevent any premature accessing to
2954 // a shared class at runtime while the class is still being loaded and
2955 // restored. A class' init_state is set to 'loaded' at runtime when it's
2956 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2957 _init_state = allocated;
2958
2959 { // Otherwise this needs to take out the Compile_lock.
2960 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2961 init_implementor();
2962 }
2963
2964 // Call remove_unshareable_info() on other objects that belong to this class, except
2965 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2966 // ArchiveBuilder::make_klasses_shareable(),
2967
2968 for (int i = 0; i < methods()->length(); i++) {
2969 Method* m = methods()->at(i);
2970 m->remove_unshareable_info();
2971 }
2972
2973 // do array classes also.
2974 if (array_klasses() != nullptr) {
2975 array_klasses()->remove_unshareable_info();
2976 }
2977
2978 // These are not allocated from metaspace. They are safe to set to nullptr.
2979 _source_debug_extension = nullptr;
2980 _dep_context = nullptr;
2981 _osr_nmethods_head = nullptr;
2982 #if INCLUDE_JVMTI
2983 _breakpoints = nullptr;
2984 _previous_versions = nullptr;
2985 _cached_class_file = nullptr;
2986 _jvmti_cached_class_field_map = nullptr;
2987 #endif
2988
2989 _init_thread = nullptr;
2990 _methods_jmethod_ids = nullptr;
2991 _jni_ids = nullptr;
2992 _oop_map_cache = nullptr;
2993 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2994 // keep _nest_host
2995 } else {
2996 // clear _nest_host to ensure re-load at runtime
2997 _nest_host = nullptr;
2998 }
2999 init_shared_package_entry();
3000 _dep_context_last_cleaned = 0;
3001 DEBUG_ONLY(_shared_class_load_count = 0);
3002
3003 remove_unshareable_flags();
3004 }
3005
3006 void InstanceKlass::remove_unshareable_flags() {
3007 // clear all the flags/stats that shouldn't be in the archived version
3008 assert(!is_scratch_class(), "must be");
3009 assert(!has_been_redefined(), "must be");
3010 #if INCLUDE_JVMTI
3011 set_is_being_redefined(false);
3012 #endif
3013 set_has_resolved_methods(false);
3014 }
3015
3016 void InstanceKlass::remove_java_mirror() {
3017 Klass::remove_java_mirror();
3018
3019 // do array classes also.
3020 if (array_klasses() != nullptr) {
3021 array_klasses()->remove_java_mirror();
3022 }
3023 }
3024
3025 void InstanceKlass::init_shared_package_entry() {
3026 assert(CDSConfig::is_dumping_archive(), "must be");
3027 #if !INCLUDE_CDS_JAVA_HEAP
3028 _package_entry = nullptr;
3029 #else
3030 if (CDSConfig::is_dumping_full_module_graph()) {
3031 if (is_shared_unregistered_class()) {
3032 _package_entry = nullptr;
3033 } else {
3034 _package_entry = PackageEntry::get_archived_entry(_package_entry);
3035 }
3036 } else if (CDSConfig::is_dumping_dynamic_archive() &&
3037 CDSConfig::is_using_full_module_graph() &&
3038 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
3039 // _package_entry is an archived package in the base archive. Leave it as is.
3040 } else {
3041 _package_entry = nullptr;
3042 }
3043 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
3044 #endif
3045 }
3046
3047 void InstanceKlass::compute_has_loops_flag_for_methods() {
3048 Array<Method*>* methods = this->methods();
3049 for (int index = 0; index < methods->length(); ++index) {
3050 Method* m = methods->at(index);
3051 if (!m->is_overpass()) { // work around JDK-8305771
3052 m->compute_has_loops_flag();
3053 }
3054 }
3055 }
3056
3057 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
3058 PackageEntry* pkg_entry, TRAPS) {
3059 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
3060 // before the InstanceKlass is added to the SystemDictionary. Make
3061 // sure the current state is <loaded.
3062 assert(!is_loaded(), "invalid init state");
3063 assert(!shared_loading_failed(), "Must not try to load failed class again");
3064 set_package(loader_data, pkg_entry, CHECK);
3065 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
3066
3067 if (is_inline_klass()) {
3068 InlineKlass::cast(this)->initialize_calling_convention(CHECK);
3069 }
3070
3071 Array<Method*>* methods = this->methods();
3072 int num_methods = methods->length();
3073 for (int index = 0; index < num_methods; ++index) {
3074 methods->at(index)->restore_unshareable_info(CHECK);
3075 }
3076 #if INCLUDE_JVMTI
3077 if (JvmtiExport::has_redefined_a_class()) {
3078 // Reinitialize vtable because RedefineClasses may have changed some
3079 // entries in this vtable for super classes so the CDS vtable might
3080 // point to old or obsolete entries. RedefineClasses doesn't fix up
3081 // vtables in the shared system dictionary, only the main one.
3082 // It also redefines the itable too so fix that too.
3083 // First fix any default methods that point to a super class that may
3084 // have been redefined.
3085 bool trace_name_printed = false;
3086 adjust_default_methods(&trace_name_printed);
3087 if (verified_at_dump_time()) {
3088 // Initialize vtable and itable for classes which can be verified at dump time.
3089 // Unlinked classes such as old classes with major version < 50 cannot be verified
3090 // at dump time.
3091 vtable().initialize_vtable();
3092 itable().initialize_itable();
3093 }
3094 }
3095 #endif // INCLUDE_JVMTI
3096
3097 // restore constant pool resolved references
3098 constants()->restore_unshareable_info(CHECK);
3099
3100 if (array_klasses() != nullptr) {
3101 // To get a consistent list of classes we need MultiArray_lock to ensure
3102 // array classes aren't observed while they are being restored.
3103 RecursiveLocker rl(MultiArray_lock, THREAD);
3104 assert(this == ObjArrayKlass::cast(array_klasses())->bottom_klass(), "sanity");
3105 // Array classes have null protection domain.
3106 // --> see ArrayKlass::complete_create_array_klass()
3107 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
3108 }
3109
3110 // Initialize @ValueBased class annotation if not already set in the archived klass.
3111 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
3112 set_is_value_based();
3113 }
3114 }
3115
3116 // Check if a class or any of its supertypes has a version older than 50.
3117 // CDS will not perform verification of old classes during dump time because
3118 // without changing the old verifier, the verification constraint cannot be
3119 // retrieved during dump time.
3120 // Verification of archived old classes will be performed during run time.
3121 bool InstanceKlass::can_be_verified_at_dumptime() const {
3122 if (MetaspaceShared::is_in_shared_metaspace(this)) {
3123 // This is a class that was dumped into the base archive, so we know
3124 // it was verified at dump time.
3125 return true;
3126 }
3127 if (major_version() < 50 /*JAVA_6_VERSION*/) {
3128 return false;
3129 }
3130 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
3131 return false;
3132 }
3133 Array<InstanceKlass*>* interfaces = local_interfaces();
3134 int len = interfaces->length();
3135 for (int i = 0; i < len; i++) {
3136 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
3137 return false;
3138 }
3139 }
3140 return true;
3141 }
3142
3143 int InstanceKlass::shared_class_loader_type() const {
3144 if (is_shared_boot_class()) {
3145 return ClassLoader::BOOT_LOADER;
3146 } else if (is_shared_platform_class()) {
3147 return ClassLoader::PLATFORM_LOADER;
3148 } else if (is_shared_app_class()) {
3149 return ClassLoader::APP_LOADER;
3150 } else {
3151 return ClassLoader::OTHER;
3152 }
3153 }
3154 #endif // INCLUDE_CDS
3155
3156 #if INCLUDE_JVMTI
3157 static void clear_all_breakpoints(Method* m) {
3158 m->clear_all_breakpoints();
3159 }
3160 #endif
3161
3162 void InstanceKlass::unload_class(InstanceKlass* ik) {
3163
3164 if (ik->is_scratch_class()) {
3165 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
3166 return;
3167 }
3168 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
3169
3170 // Release dependencies.
3171 ik->dependencies().remove_all_dependents();
3172
3173 // notify the debugger
3174 if (JvmtiExport::should_post_class_unload()) {
3175 JvmtiExport::post_class_unload(ik);
3176 }
3177
3178 // notify ClassLoadingService of class unload
3179 ClassLoadingService::notify_class_unloaded(ik);
3180
3181 SystemDictionaryShared::handle_class_unloading(ik);
3182
3183 if (log_is_enabled(Info, class, unload)) {
3184 ResourceMark rm;
3185 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
3186 }
3187
3188 Events::log_class_unloading(Thread::current(), ik);
3189
3190 #if INCLUDE_JFR
3191 assert(ik != nullptr, "invariant");
3192 EventClassUnload event;
3193 event.set_unloadedClass(ik);
3194 event.set_definingClassLoader(ik->class_loader_data());
3195 event.commit();
3196 #endif
3197 }
3198
3199 static void method_release_C_heap_structures(Method* m) {
3200 m->release_C_heap_structures();
3201 }
3202
3203 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
3204 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
3205 // Clean up C heap
3206 Klass::release_C_heap_structures();
3207
3208 // Deallocate and call destructors for MDO mutexes
3209 if (release_sub_metadata) {
3210 methods_do(method_release_C_heap_structures);
3211 }
3212
3213 // Deallocate oop map cache
3214 if (_oop_map_cache != nullptr) {
3215 delete _oop_map_cache;
3216 _oop_map_cache = nullptr;
3217 }
3218
3219 // Deallocate JNI identifiers for jfieldIDs
3220 JNIid::deallocate(jni_ids());
3221 set_jni_ids(nullptr);
3222
3223 jmethodID* jmeths = methods_jmethod_ids_acquire();
3224 if (jmeths != nullptr) {
3225 release_set_methods_jmethod_ids(nullptr);
3226 FreeHeap(jmeths);
3227 }
3228
3229 assert(_dep_context == nullptr,
3230 "dependencies should already be cleaned");
3231
3232 #if INCLUDE_JVMTI
3233 // Deallocate breakpoint records
3234 if (breakpoints() != nullptr) {
3235 methods_do(clear_all_breakpoints);
3236 assert(breakpoints() == nullptr, "should have cleared breakpoints");
3237 }
3238
3239 // deallocate the cached class file
3240 if (_cached_class_file != nullptr) {
3241 os::free(_cached_class_file);
3242 _cached_class_file = nullptr;
3243 }
3244 #endif
3245
3246 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
3247
3248 if (release_sub_metadata) {
3249 constants()->release_C_heap_structures();
3250 }
3251 }
3252
3253 // The constant pool is on stack if any of the methods are executing or
3254 // referenced by handles.
3255 bool InstanceKlass::on_stack() const {
3256 return _constants->on_stack();
3257 }
3258
3259 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
3260 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
3261 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3262
3263 // minor and major version numbers of class file
3264 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
3265 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3266 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
3267 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3268
3269 InstanceKlass* InstanceKlass::get_klass_version(int version) {
3270 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3271 if (ik->constants()->version() == version) {
3272 return ik;
3273 }
3274 }
3275 return nullptr;
3276 }
3277
3278 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3279 if (array == nullptr) {
3280 _source_debug_extension = nullptr;
3281 } else {
3282 // Adding one to the attribute length in order to store a null terminator
3283 // character could cause an overflow because the attribute length is
3284 // already coded with an u4 in the classfile, but in practice, it's
3285 // unlikely to happen.
3286 assert((length+1) > length, "Overflow checking");
3287 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3288 for (int i = 0; i < length; i++) {
3289 sde[i] = array[i];
3290 }
3291 sde[length] = '\0';
3292 _source_debug_extension = sde;
3293 }
3294 }
3295
3296 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3297 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3298 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3299
3300 const char* InstanceKlass::signature_name() const {
3301 return signature_name_of_carrier(JVM_SIGNATURE_CLASS);
3302 }
3303
3304 const char* InstanceKlass::signature_name_of_carrier(char c) const {
3305 // Get the internal name as a c string
3306 const char* src = (const char*) (name()->as_C_string());
3307 const int src_length = (int)strlen(src);
3308
3309 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3310
3311 // Add L or Q as type indicator
3312 int dest_index = 0;
3313 dest[dest_index++] = c;
3314
3315 // Add the actual class name
3316 for (int src_index = 0; src_index < src_length; ) {
3317 dest[dest_index++] = src[src_index++];
3318 }
3319
3320 if (is_hidden()) { // Replace the last '+' with a '.'.
3321 for (int index = (int)src_length; index > 0; index--) {
3322 if (dest[index] == '+') {
3323 dest[index] = JVM_SIGNATURE_DOT;
3324 break;
3325 }
3326 }
3327 }
3328
3329 // Add the semicolon and the null
3330 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3331 dest[dest_index] = '\0';
3332 return dest;
3333 }
3334
3335 ModuleEntry* InstanceKlass::module() const {
3336 if (is_hidden() &&
3337 in_unnamed_package() &&
3338 class_loader_data()->has_class_mirror_holder()) {
3339 // For a non-strong hidden class defined to an unnamed package,
3340 // its (class held) CLD will not have an unnamed module created for it.
3341 // Two choices to find the correct ModuleEntry:
3342 // 1. If hidden class is within a nest, use nest host's module
3343 // 2. Find the unnamed module off from the class loader
3344 // For now option #2 is used since a nest host is not set until
3345 // after the instance class is created in jvm_lookup_define_class().
3346 if (class_loader_data()->is_boot_class_loader_data()) {
3347 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3348 } else {
3349 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3350 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3351 return java_lang_Module::module_entry(module);
3352 }
3353 }
3354
3355 // Class is in a named package
3356 if (!in_unnamed_package()) {
3357 return _package_entry->module();
3358 }
3359
3360 // Class is in an unnamed package, return its loader's unnamed module
3361 return class_loader_data()->unnamed_module();
3362 }
3363
3364 bool InstanceKlass::in_javabase_module() const {
3365 return module()->name() == vmSymbols::java_base();
3366 }
3367
3368 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3369
3370 // ensure java/ packages only loaded by boot or platform builtin loaders
3371 // not needed for shared class since CDS does not archive prohibited classes.
3372 if (!is_shared()) {
3373 check_prohibited_package(name(), loader_data, CHECK);
3374 }
3375
3376 if (is_shared() && _package_entry != nullptr) {
3377 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3378 // we can use the saved package
3379 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3380 return;
3381 } else {
3382 _package_entry = nullptr;
3383 }
3384 }
3385
3386 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3387 // it returns, so we need to decrement it when the current function exits.
3388 TempNewSymbol from_class_name =
3389 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3390
3391 Symbol* pkg_name;
3392 if (pkg_entry != nullptr) {
3393 pkg_name = pkg_entry->name();
3394 } else {
3395 pkg_name = from_class_name;
3396 }
3397
3398 if (pkg_name != nullptr && loader_data != nullptr) {
3399
3400 // Find in class loader's package entry table.
3401 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3402
3403 // If the package name is not found in the loader's package
3404 // entry table, it is an indication that the package has not
3405 // been defined. Consider it defined within the unnamed module.
3406 if (_package_entry == nullptr) {
3407
3408 if (!ModuleEntryTable::javabase_defined()) {
3409 // Before java.base is defined during bootstrapping, define all packages in
3410 // the java.base module. If a non-java.base package is erroneously placed
3411 // in the java.base module it will be caught later when java.base
3412 // is defined by ModuleEntryTable::verify_javabase_packages check.
3413 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3414 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3415 } else {
3416 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3417 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3418 }
3419
3420 // A package should have been successfully created
3421 DEBUG_ONLY(ResourceMark rm(THREAD));
3422 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3423 name()->as_C_string(), loader_data->loader_name_and_id());
3424 }
3425
3426 if (log_is_enabled(Debug, module)) {
3427 ResourceMark rm(THREAD);
3428 ModuleEntry* m = _package_entry->module();
3429 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3430 external_name(),
3431 pkg_name->as_C_string(),
3432 loader_data->loader_name_and_id(),
3433 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3434 }
3435 } else {
3436 ResourceMark rm(THREAD);
3437 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3438 external_name(),
3439 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3440 UNNAMED_MODULE);
3441 }
3442 }
3443
3444 // Function set_classpath_index ensures that for a non-null _package_entry
3445 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3446 // It then sets the classpath_index in the package entry record.
3447 //
3448 // The classpath_index field is used to find the entry on the boot loader class
3449 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3450 // in an unnamed module. It is also used to indicate (for all packages whose
3451 // classes are loaded by the boot loader) that at least one of the package's
3452 // classes has been loaded.
3453 void InstanceKlass::set_classpath_index(s2 path_index) {
3454 if (_package_entry != nullptr) {
3455 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3456 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3457 assert(path_index != -1, "Unexpected classpath_index");
3458 _package_entry->set_classpath_index(path_index);
3459 }
3460 }
3461
3462 // different versions of is_same_class_package
3463
3464 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3465 oop classloader1 = this->class_loader();
3466 PackageEntry* classpkg1 = this->package();
3467 if (class2->is_objArray_klass()) {
3468 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3469 }
3470
3471 oop classloader2;
3472 PackageEntry* classpkg2;
3473 if (class2->is_instance_klass()) {
3474 classloader2 = class2->class_loader();
3475 classpkg2 = class2->package();
3476 } else {
3477 assert(class2->is_typeArray_klass(), "should be type array");
3478 classloader2 = nullptr;
3479 classpkg2 = nullptr;
3480 }
3481
3482 // Same package is determined by comparing class loader
3483 // and package entries. Both must be the same. This rule
3484 // applies even to classes that are defined in the unnamed
3485 // package, they still must have the same class loader.
3486 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3487 return true;
3488 }
3489
3490 return false;
3491 }
3492
3493 // return true if this class and other_class are in the same package. Classloader
3494 // and classname information is enough to determine a class's package
3495 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3496 const Symbol* other_class_name) const {
3497 if (class_loader() != other_class_loader) {
3498 return false;
3499 }
3500 if (name()->fast_compare(other_class_name) == 0) {
3501 return true;
3502 }
3503
3504 {
3505 ResourceMark rm;
3506
3507 bool bad_class_name = false;
3508 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3509 if (bad_class_name) {
3510 return false;
3511 }
3512 // Check that package_from_class_name() returns null, not "", if there is no package.
3513 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3514
3515 const Symbol* const this_package_name =
3516 this->package() != nullptr ? this->package()->name() : nullptr;
3517
3518 if (this_package_name == nullptr || other_pkg == nullptr) {
3519 // One of the two doesn't have a package. Only return true if the other
3520 // one also doesn't have a package.
3521 return this_package_name == other_pkg;
3522 }
3523
3524 // Check if package is identical
3525 return this_package_name->fast_compare(other_pkg) == 0;
3526 }
3527 }
3528
3529 static bool is_prohibited_package_slow(Symbol* class_name) {
3530 // Caller has ResourceMark
3531 int length;
3532 jchar* unicode = class_name->as_unicode(length);
3533 return (length >= 5 &&
3534 unicode[0] == 'j' &&
3535 unicode[1] == 'a' &&
3536 unicode[2] == 'v' &&
3537 unicode[3] == 'a' &&
3538 unicode[4] == '/');
3539 }
3540
3541 // Only boot and platform class loaders can define classes in "java/" packages.
3542 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3543 ClassLoaderData* loader_data,
3544 TRAPS) {
3545 if (!loader_data->is_boot_class_loader_data() &&
3546 !loader_data->is_platform_class_loader_data() &&
3547 class_name != nullptr && class_name->utf8_length() >= 5) {
3548 ResourceMark rm(THREAD);
3549 bool prohibited;
3550 const u1* base = class_name->base();
3551 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3552 prohibited = is_prohibited_package_slow(class_name);
3553 } else {
3554 char* name = class_name->as_C_string();
3555 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3556 }
3557 if (prohibited) {
3558 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3559 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3560 char* name = pkg_name->as_C_string();
3561 const char* class_loader_name = loader_data->loader_name_and_id();
3562 StringUtils::replace_no_expand(name, "/", ".");
3563 const char* msg_text1 = "Class loader (instance of): ";
3564 const char* msg_text2 = " tried to load prohibited package name: ";
3565 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3566 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3567 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3568 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3569 }
3570 }
3571 return;
3572 }
3573
3574 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3575 constantPoolHandle i_cp(THREAD, constants());
3576 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3577 int ioff = iter.inner_class_info_index();
3578 if (ioff != 0) {
3579 // Check to see if the name matches the class we're looking for
3580 // before attempting to find the class.
3581 if (i_cp->klass_name_at_matches(this, ioff)) {
3582 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3583 if (this == inner_klass) {
3584 *ooff = iter.outer_class_info_index();
3585 *noff = iter.inner_name_index();
3586 return true;
3587 }
3588 }
3589 }
3590 }
3591 return false;
3592 }
3593
3594 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3595 InstanceKlass* outer_klass = nullptr;
3596 *inner_is_member = false;
3597 int ooff = 0, noff = 0;
3598 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3599 if (has_inner_classes_attr) {
3600 constantPoolHandle i_cp(THREAD, constants());
3601 if (ooff != 0) {
3602 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3603 if (!ok->is_instance_klass()) {
3604 // If the outer class is not an instance klass then it cannot have
3605 // declared any inner classes.
3606 ResourceMark rm(THREAD);
3607 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3608 Exceptions::fthrow(
3609 THREAD_AND_LOCATION,
3610 vmSymbols::java_lang_IncompatibleClassChangeError(),
3611 "%s and %s disagree on InnerClasses attribute",
3612 ok->external_name(),
3613 external_name());
3614 return nullptr;
3615 }
3616 outer_klass = InstanceKlass::cast(ok);
3617 *inner_is_member = true;
3618 }
3619 if (nullptr == outer_klass) {
3620 // It may be a local class; try for that.
3621 int encl_method_class_idx = enclosing_method_class_index();
3622 if (encl_method_class_idx != 0) {
3623 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3624 outer_klass = InstanceKlass::cast(ok);
3625 *inner_is_member = false;
3626 }
3627 }
3628 }
3629
3630 // If no inner class attribute found for this class.
3631 if (nullptr == outer_klass) return nullptr;
3632
3633 // Throws an exception if outer klass has not declared k as an inner klass
3634 // We need evidence that each klass knows about the other, or else
3635 // the system could allow a spoof of an inner class to gain access rights.
3636 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3637 return outer_klass;
3638 }
3639
3640 u2 InstanceKlass::compute_modifier_flags() const {
3641 u2 access = access_flags().as_unsigned_short();
3642
3643 // But check if it happens to be member class.
3644 InnerClassesIterator iter(this);
3645 for (; !iter.done(); iter.next()) {
3646 int ioff = iter.inner_class_info_index();
3647 // Inner class attribute can be zero, skip it.
3648 // Strange but true: JVM spec. allows null inner class refs.
3649 if (ioff == 0) continue;
3650
3651 // only look at classes that are already loaded
3652 // since we are looking for the flags for our self.
3653 Symbol* inner_name = constants()->klass_name_at(ioff);
3654 if (name() == inner_name) {
3655 // This is really a member class.
3656 access = iter.inner_access_flags();
3657 break;
3658 }
3659 }
3660 return access;
3661 }
3662
3663 jint InstanceKlass::jvmti_class_status() const {
3664 jint result = 0;
3665
3666 if (is_linked()) {
3667 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3668 }
3669
3670 if (is_initialized()) {
3671 assert(is_linked(), "Class status is not consistent");
3672 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3673 }
3674 if (is_in_error_state()) {
3675 result |= JVMTI_CLASS_STATUS_ERROR;
3676 }
3677 return result;
3678 }
3679
3680 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3681 bool implements_interface; // initialized by method_at_itable_or_null
3682 Method* m = method_at_itable_or_null(holder, index,
3683 implements_interface); // out parameter
3684 if (m != nullptr) {
3685 assert(implements_interface, "sanity");
3686 return m;
3687 } else if (implements_interface) {
3688 // Throw AbstractMethodError since corresponding itable slot is empty.
3689 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3690 } else {
3691 // If the interface isn't implemented by the receiver class,
3692 // the VM should throw IncompatibleClassChangeError.
3693 ResourceMark rm(THREAD);
3694 stringStream ss;
3695 bool same_module = (module() == holder->module());
3696 ss.print("Receiver class %s does not implement "
3697 "the interface %s defining the method to be called "
3698 "(%s%s%s)",
3699 external_name(), holder->external_name(),
3700 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3701 (same_module) ? "" : "; ",
3702 (same_module) ? "" : holder->class_in_module_of_loader());
3703 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3704 }
3705 }
3706
3707 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3708 klassItable itable(this);
3709 for (int i = 0; i < itable.size_offset_table(); i++) {
3710 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3711 if (offset_entry->interface_klass() == holder) {
3712 implements_interface = true;
3713 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3714 Method* m = ime[index].method();
3715 return m;
3716 }
3717 }
3718 implements_interface = false;
3719 return nullptr; // offset entry not found
3720 }
3721
3722 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3723 assert(is_linked(), "required");
3724 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3725 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3726
3727 int vtable_index = Method::invalid_vtable_index;
3728 Symbol* name = intf_method->name();
3729 Symbol* signature = intf_method->signature();
3730
3731 // First check in default method array
3732 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3733 int index = find_method_index(default_methods(),
3734 name, signature,
3735 Klass::OverpassLookupMode::find,
3736 Klass::StaticLookupMode::find,
3737 Klass::PrivateLookupMode::find);
3738 if (index >= 0) {
3739 vtable_index = default_vtable_indices()->at(index);
3740 }
3741 }
3742 if (vtable_index == Method::invalid_vtable_index) {
3743 // get vtable_index for miranda methods
3744 klassVtable vt = vtable();
3745 vtable_index = vt.index_of_miranda(name, signature);
3746 }
3747 return vtable_index;
3748 }
3749
3750 #if INCLUDE_JVMTI
3751 // update default_methods for redefineclasses for methods that are
3752 // not yet in the vtable due to concurrent subclass define and superinterface
3753 // redefinition
3754 // Note: those in the vtable, should have been updated via adjust_method_entries
3755 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3756 // search the default_methods for uses of either obsolete or EMCP methods
3757 if (default_methods() != nullptr) {
3758 for (int index = 0; index < default_methods()->length(); index ++) {
3759 Method* old_method = default_methods()->at(index);
3760 if (old_method == nullptr || !old_method->is_old()) {
3761 continue; // skip uninteresting entries
3762 }
3763 assert(!old_method->is_deleted(), "default methods may not be deleted");
3764 Method* new_method = old_method->get_new_method();
3765 default_methods()->at_put(index, new_method);
3766
3767 if (log_is_enabled(Info, redefine, class, update)) {
3768 ResourceMark rm;
3769 if (!(*trace_name_printed)) {
3770 log_info(redefine, class, update)
3771 ("adjust: klassname=%s default methods from name=%s",
3772 external_name(), old_method->method_holder()->external_name());
3773 *trace_name_printed = true;
3774 }
3775 log_debug(redefine, class, update, vtables)
3776 ("default method update: %s(%s) ",
3777 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3778 }
3779 }
3780 }
3781 }
3782 #endif // INCLUDE_JVMTI
3783
3784 // On-stack replacement stuff
3785 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3786 assert_lock_strong(NMethodState_lock);
3787 #ifndef PRODUCT
3788 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3789 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3790 "redundant OSR recompilation detected. memory leak in CodeCache!");
3791 #endif
3792 // only one compilation can be active
3793 assert(n->is_osr_method(), "wrong kind of nmethod");
3794 n->set_osr_link(osr_nmethods_head());
3795 set_osr_nmethods_head(n);
3796 // Raise the highest osr level if necessary
3797 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3798
3799 // Get rid of the osr methods for the same bci that have lower levels.
3800 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3801 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3802 if (inv != nullptr && inv->is_in_use()) {
3803 inv->make_not_entrant("OSR invalidation of lower levels");
3804 }
3805 }
3806 }
3807
3808 // Remove osr nmethod from the list. Return true if found and removed.
3809 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3810 // This is a short non-blocking critical region, so the no safepoint check is ok.
3811 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3812 assert(n->is_osr_method(), "wrong kind of nmethod");
3813 nmethod* last = nullptr;
3814 nmethod* cur = osr_nmethods_head();
3815 int max_level = CompLevel_none; // Find the max comp level excluding n
3816 Method* m = n->method();
3817 // Search for match
3818 bool found = false;
3819 while(cur != nullptr && cur != n) {
3820 if (m == cur->method()) {
3821 // Find max level before n
3822 max_level = MAX2(max_level, cur->comp_level());
3823 }
3824 last = cur;
3825 cur = cur->osr_link();
3826 }
3827 nmethod* next = nullptr;
3828 if (cur == n) {
3829 found = true;
3830 next = cur->osr_link();
3831 if (last == nullptr) {
3832 // Remove first element
3833 set_osr_nmethods_head(next);
3834 } else {
3835 last->set_osr_link(next);
3836 }
3837 }
3838 n->set_osr_link(nullptr);
3839 cur = next;
3840 while (cur != nullptr) {
3841 // Find max level after n
3842 if (m == cur->method()) {
3843 max_level = MAX2(max_level, cur->comp_level());
3844 }
3845 cur = cur->osr_link();
3846 }
3847 m->set_highest_osr_comp_level(max_level);
3848 return found;
3849 }
3850
3851 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3852 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3853 nmethod* osr = osr_nmethods_head();
3854 int found = 0;
3855 while (osr != nullptr) {
3856 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3857 if (osr->method() == m) {
3858 deopt_scope->mark(osr);
3859 found++;
3860 }
3861 osr = osr->osr_link();
3862 }
3863 return found;
3864 }
3865
3866 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3867 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3868 nmethod* osr = osr_nmethods_head();
3869 nmethod* best = nullptr;
3870 while (osr != nullptr) {
3871 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3872 // There can be a time when a c1 osr method exists but we are waiting
3873 // for a c2 version. When c2 completes its osr nmethod we will trash
3874 // the c1 version and only be able to find the c2 version. However
3875 // while we overflow in the c1 code at back branches we don't want to
3876 // try and switch to the same code as we are already running
3877
3878 if (osr->method() == m &&
3879 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3880 if (match_level) {
3881 if (osr->comp_level() == comp_level) {
3882 // Found a match - return it.
3883 return osr;
3884 }
3885 } else {
3886 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3887 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3888 // Found the best possible - return it.
3889 return osr;
3890 }
3891 best = osr;
3892 }
3893 }
3894 }
3895 osr = osr->osr_link();
3896 }
3897
3898 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3899 if (best != nullptr && best->comp_level() >= comp_level) {
3900 return best;
3901 }
3902 return nullptr;
3903 }
3904
3905 // -----------------------------------------------------------------------------------------------------
3906 // Printing
3907
3908 #define BULLET " - "
3909
3910 static const char* state_names[] = {
3911 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3912 };
3913
3914 static void print_vtable(address self, intptr_t* start, int len, outputStream* st) {
3915 ResourceMark rm;
3916 int* forward_refs = NEW_RESOURCE_ARRAY(int, len);
3917 for (int i = 0; i < len; i++) forward_refs[i] = 0;
3918 for (int i = 0; i < len; i++) {
3919 intptr_t e = start[i];
3920 st->print("%d : " INTPTR_FORMAT, i, e);
3921 if (forward_refs[i] != 0) {
3922 int from = forward_refs[i];
3923 int off = (int) start[from];
3924 st->print(" (offset %d <= [%d])", off, from);
3925 }
3926 if (MetaspaceObj::is_valid((Metadata*)e)) {
3927 st->print(" ");
3928 ((Metadata*)e)->print_value_on(st);
3929 } else if (self != nullptr && e > 0 && e < 0x10000) {
3930 address location = self + e;
3931 int index = (int)((intptr_t*)location - start);
3932 st->print(" (offset %d => [%d])", (int)e, index);
3933 if (index >= 0 && index < len)
3934 forward_refs[index] = i;
3935 }
3936 st->cr();
3937 }
3938 }
3939
3940 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3941 return print_vtable(nullptr, reinterpret_cast<intptr_t*>(start), len, st);
3942 }
3943
3944 template<typename T>
3945 static void print_array_on(outputStream* st, Array<T>* array) {
3946 if (array == nullptr) { st->print_cr("nullptr"); return; }
3947 array->print_value_on(st); st->cr();
3948 if (Verbose || WizardMode) {
3949 for (int i = 0; i < array->length(); i++) {
3950 st->print("%d : ", i); array->at(i)->print_value_on(st); st->cr();
3951 }
3952 }
3953 }
3954
3955 static void print_array_on(outputStream* st, Array<int>* array) {
3956 if (array == nullptr) { st->print_cr("nullptr"); return; }
3957 array->print_value_on(st); st->cr();
3958 if (Verbose || WizardMode) {
3959 for (int i = 0; i < array->length(); i++) {
3960 st->print("%d : %d", i, array->at(i)); st->cr();
3961 }
3962 }
3963 }
3964
3965 const char* InstanceKlass::init_state_name() const {
3966 return state_names[init_state()];
3967 }
3968
3969 void InstanceKlass::print_on(outputStream* st) const {
3970 assert(is_klass(), "must be klass");
3971 Klass::print_on(st);
3972
3973 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3974 st->print(BULLET"klass size: %d", size()); st->cr();
3975 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3976 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3977 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3978 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3979 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3980 st->print(BULLET"sub: ");
3981 Klass* sub = subklass();
3982 int n;
3983 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3984 if (n < MaxSubklassPrintSize) {
3985 sub->print_value_on(st);
3986 st->print(" ");
3987 }
3988 }
3989 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3990 st->cr();
3991
3992 if (is_interface()) {
3993 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3994 if (nof_implementors() == 1) {
3995 st->print_cr(BULLET"implementor: ");
3996 st->print(" ");
3997 implementor()->print_value_on(st);
3998 st->cr();
3999 }
4000 }
4001
4002 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
4003 st->print(BULLET"methods: "); print_array_on(st, methods());
4004 st->print(BULLET"method ordering: "); print_array_on(st, method_ordering());
4005 if (default_methods() != nullptr) {
4006 st->print(BULLET"default_methods: "); print_array_on(st, default_methods());
4007 }
4008 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
4009 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
4010 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
4011
4012 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
4013
4014 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
4015 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
4016
4017 if (secondary_supers() != nullptr) {
4018 if (Verbose) {
4019 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
4020 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
4021 for (int i = 0; i < _secondary_supers->length(); i++) {
4022 ResourceMark rm; // for external_name()
4023 Klass* secondary_super = _secondary_supers->at(i);
4024 st->print(BULLET"%2d:", i);
4025 if (is_hashed) {
4026 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
4027 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
4028 st->print(" dist:%02d:", distance);
4029 }
4030 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
4031 }
4032 }
4033 }
4034 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
4035
4036 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
4037 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
4038 if (source_debug_extension() != nullptr) {
4039 st->print(BULLET"source debug extension: ");
4040 st->print("%s", source_debug_extension());
4041 st->cr();
4042 }
4043 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
4044 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
4045 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
4046 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
4047 {
4048 bool have_pv = false;
4049 // previous versions are linked together through the InstanceKlass
4050 for (InstanceKlass* pv_node = previous_versions();
4051 pv_node != nullptr;
4052 pv_node = pv_node->previous_versions()) {
4053 if (!have_pv)
4054 st->print(BULLET"previous version: ");
4055 have_pv = true;
4056 pv_node->constants()->print_value_on(st);
4057 }
4058 if (have_pv) st->cr();
4059 }
4060
4061 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
4062 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
4063 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
4064 print_on_maybe_null(st, BULLET"record components: ", record_components());
4065 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
4066 st->print(BULLET"loadable descriptors: "); loadable_descriptors()->print_value_on(st); st->cr();
4067 if (java_mirror() != nullptr) {
4068 st->print(BULLET"java mirror: ");
4069 java_mirror()->print_value_on(st);
4070 st->cr();
4071 } else {
4072 st->print_cr(BULLET"java mirror: null");
4073 }
4074 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
4075 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
4076 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
4077 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(nullptr, start_of_itable(), itable_length(), st);
4078 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
4079
4080 FieldPrinter print_static_field(st);
4081 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
4082 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
4083 FieldPrinter print_nonstatic_field(st);
4084 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
4085 ik->print_nonstatic_fields(&print_nonstatic_field);
4086
4087 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
4088 OopMapBlock* map = start_of_nonstatic_oop_maps();
4089 OopMapBlock* end_map = map + nonstatic_oop_map_count();
4090 while (map < end_map) {
4091 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
4092 map++;
4093 }
4094 st->cr();
4095 }
4096
4097 void InstanceKlass::print_value_on(outputStream* st) const {
4098 assert(is_klass(), "must be klass");
4099 if (Verbose || WizardMode) access_flags().print_on(st);
4100 name()->print_value_on(st);
4101 }
4102
4103 void FieldPrinter::do_field(fieldDescriptor* fd) {
4104 for (int i = 0; i < _indent; i++) _st->print(" ");
4105 _st->print(BULLET);
4106 if (_obj == nullptr) {
4107 fd->print_on(_st, _base_offset);
4108 _st->cr();
4109 } else {
4110 fd->print_on_for(_st, _obj, _indent, _base_offset);
4111 if (!fd->field_flags().is_flat()) _st->cr();
4112 }
4113 }
4114
4115
4116 void InstanceKlass::oop_print_on(oop obj, outputStream* st, int indent, int base_offset) {
4117 Klass::oop_print_on(obj, st);
4118
4119 if (this == vmClasses::String_klass()) {
4120 typeArrayOop value = java_lang_String::value(obj);
4121 juint length = java_lang_String::length(obj);
4122 if (value != nullptr &&
4123 value->is_typeArray() &&
4124 length <= (juint) value->length()) {
4125 st->print(BULLET"string: ");
4126 java_lang_String::print(obj, st);
4127 st->cr();
4128 }
4129 }
4130
4131 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
4132 FieldPrinter print_field(st, obj, indent, base_offset);
4133 print_nonstatic_fields(&print_field);
4134
4135 if (this == vmClasses::Class_klass()) {
4136 st->print(BULLET"signature: ");
4137 java_lang_Class::print_signature(obj, st);
4138 st->cr();
4139 Klass* real_klass = java_lang_Class::as_Klass(obj);
4140 if (real_klass != nullptr && real_klass->is_instance_klass()) {
4141 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
4142 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
4143 }
4144 } else if (this == vmClasses::MethodType_klass()) {
4145 st->print(BULLET"signature: ");
4146 java_lang_invoke_MethodType::print_signature(obj, st);
4147 st->cr();
4148 }
4149 }
4150
4151 #ifndef PRODUCT
4152
4153 bool InstanceKlass::verify_itable_index(int i) {
4154 int method_count = klassItable::method_count_for_interface(this);
4155 assert(i >= 0 && i < method_count, "index out of bounds");
4156 return true;
4157 }
4158
4159 #endif //PRODUCT
4160
4161 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
4162 st->print("a ");
4163 name()->print_value_on(st);
4164 obj->print_address_on(st);
4165 if (this == vmClasses::String_klass()
4166 && java_lang_String::value(obj) != nullptr) {
4167 ResourceMark rm;
4168 int len = java_lang_String::length(obj);
4169 int plen = (len < 24 ? len : 12);
4170 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
4171 st->print(" = \"%s\"", str);
4172 if (len > plen)
4173 st->print("...[%d]", len);
4174 } else if (this == vmClasses::Class_klass()) {
4175 Klass* k = java_lang_Class::as_Klass(obj);
4176 st->print(" = ");
4177 if (k != nullptr) {
4178 k->print_value_on(st);
4179 } else {
4180 const char* tname = type2name(java_lang_Class::primitive_type(obj));
4181 st->print("%s", tname ? tname : "type?");
4182 }
4183 } else if (this == vmClasses::MethodType_klass()) {
4184 st->print(" = ");
4185 java_lang_invoke_MethodType::print_signature(obj, st);
4186 } else if (java_lang_boxing_object::is_instance(obj)) {
4187 st->print(" = ");
4188 java_lang_boxing_object::print(obj, st);
4189 } else if (this == vmClasses::LambdaForm_klass()) {
4190 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
4191 if (vmentry != nullptr) {
4192 st->print(" => ");
4193 vmentry->print_value_on(st);
4194 }
4195 } else if (this == vmClasses::MemberName_klass()) {
4196 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
4197 if (vmtarget != nullptr) {
4198 st->print(" = ");
4199 vmtarget->print_value_on(st);
4200 } else {
4201 oop clazz = java_lang_invoke_MemberName::clazz(obj);
4202 oop name = java_lang_invoke_MemberName::name(obj);
4203 if (clazz != nullptr) {
4204 clazz->print_value_on(st);
4205 } else {
4206 st->print("null");
4207 }
4208 st->print(".");
4209 if (name != nullptr) {
4210 name->print_value_on(st);
4211 } else {
4212 st->print("null");
4213 }
4214 }
4215 }
4216 }
4217
4218 const char* InstanceKlass::internal_name() const {
4219 return external_name();
4220 }
4221
4222 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
4223 const ModuleEntry* module_entry,
4224 const ClassFileStream* cfs) const {
4225
4226 if (ClassListWriter::is_enabled()) {
4227 ClassListWriter::write(this, cfs);
4228 }
4229
4230 print_class_load_helper(loader_data, module_entry, cfs);
4231 print_class_load_cause_logging();
4232 }
4233
4234 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
4235 const ModuleEntry* module_entry,
4236 const ClassFileStream* cfs) const {
4237
4238 if (!log_is_enabled(Info, class, load)) {
4239 return;
4240 }
4241
4242 ResourceMark rm;
4243 LogMessage(class, load) msg;
4244 stringStream info_stream;
4245
4246 // Name and class hierarchy info
4247 info_stream.print("%s", external_name());
4248
4249 // Source
4250 if (cfs != nullptr) {
4251 if (cfs->source() != nullptr) {
4252 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
4253 if (module_name != nullptr) {
4254 // When the boot loader created the stream, it didn't know the module name
4255 // yet. Let's format it now.
4256 if (cfs->from_boot_loader_modules_image()) {
4257 info_stream.print(" source: jrt:/%s", module_name);
4258 } else {
4259 info_stream.print(" source: %s", cfs->source());
4260 }
4261 } else {
4262 info_stream.print(" source: %s", cfs->source());
4263 }
4264 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
4265 Thread* current = Thread::current();
4266 Klass* caller = current->is_Java_thread() ?
4267 JavaThread::cast(current)->security_get_caller_class(1):
4268 nullptr;
4269 // caller can be null, for example, during a JVMTI VM_Init hook
4270 if (caller != nullptr) {
4271 info_stream.print(" source: instance of %s", caller->external_name());
4272 } else {
4273 // source is unknown
4274 }
4275 } else {
4276 oop class_loader = loader_data->class_loader();
4277 info_stream.print(" source: %s", class_loader->klass()->external_name());
4278 }
4279 } else {
4280 assert(this->is_shared(), "must be");
4281 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
4282 info_stream.print(" source: shared objects file (top)");
4283 } else {
4284 info_stream.print(" source: shared objects file");
4285 }
4286 }
4287
4288 msg.info("%s", info_stream.as_string());
4289
4290 if (log_is_enabled(Debug, class, load)) {
4291 stringStream debug_stream;
4292
4293 // Class hierarchy info
4294 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4295 p2i(this), p2i(superklass()));
4296
4297 // Interfaces
4298 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4299 debug_stream.print(" interfaces:");
4300 int length = local_interfaces()->length();
4301 for (int i = 0; i < length; i++) {
4302 debug_stream.print(" " PTR_FORMAT,
4303 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
4304 }
4305 }
4306
4307 // Class loader
4308 debug_stream.print(" loader: [");
4309 loader_data->print_value_on(&debug_stream);
4310 debug_stream.print("]");
4311
4312 // Classfile checksum
4313 if (cfs) {
4314 debug_stream.print(" bytes: %d checksum: %08x",
4315 cfs->length(),
4316 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4317 cfs->length()));
4318 }
4319
4320 msg.debug("%s", debug_stream.as_string());
4321 }
4322 }
4323
4324 void InstanceKlass::print_class_load_cause_logging() const {
4325 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4326 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4327 JavaThread* current = JavaThread::current();
4328 ResourceMark rm(current);
4329 const char* name = external_name();
4330
4331 if (LogClassLoadingCauseFor == nullptr ||
4332 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4333 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4334 return;
4335 }
4336
4337 // Log Java stack first
4338 {
4339 LogMessage(class, load, cause) msg;
4340 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4341
4342 info_stream.print_cr("Java stack when loading %s:", name);
4343 current->print_stack_on(&info_stream);
4344 }
4345
4346 // Log native stack second
4347 if (log_cause_native) {
4348 // Log to string first so that lines can be indented
4349 stringStream stack_stream;
4350 char buf[O_BUFLEN];
4351 address lastpc = nullptr;
4352 NativeStackPrinter nsp(current);
4353 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4354 true /* print_source_info */, -1 /* max stack */);
4355
4356 LogMessage(class, load, cause, native) msg;
4357 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4358 info_stream.print_cr("Native stack when loading %s:", name);
4359
4360 // Print each native stack line to the log
4361 int size = (int) stack_stream.size();
4362 char* stack = stack_stream.as_string();
4363 char* stack_end = stack + size;
4364 char* line_start = stack;
4365 for (char* p = stack; p < stack_end; p++) {
4366 if (*p == '\n') {
4367 *p = '\0';
4368 info_stream.print_cr("\t%s", line_start);
4369 line_start = p + 1;
4370 }
4371 }
4372 if (line_start < stack_end) {
4373 info_stream.print_cr("\t%s", line_start);
4374 }
4375 }
4376 }
4377 }
4378
4379 // Verification
4380
4381 class VerifyFieldClosure: public BasicOopIterateClosure {
4382 protected:
4383 template <class T> void do_oop_work(T* p) {
4384 oop obj = RawAccess<>::oop_load(p);
4385 if (!oopDesc::is_oop_or_null(obj)) {
4386 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4387 Universe::print_on(tty);
4388 guarantee(false, "boom");
4389 }
4390 }
4391 public:
4392 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4393 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4394 };
4395
4396 void InstanceKlass::verify_on(outputStream* st) {
4397 #ifndef PRODUCT
4398 // Avoid redundant verifies, this really should be in product.
4399 if (_verify_count == Universe::verify_count()) return;
4400 _verify_count = Universe::verify_count();
4401 #endif
4402
4403 // Verify Klass
4404 Klass::verify_on(st);
4405
4406 // Verify that klass is present in ClassLoaderData
4407 guarantee(class_loader_data()->contains_klass(this),
4408 "this class isn't found in class loader data");
4409
4410 // Verify vtables
4411 if (is_linked()) {
4412 // $$$ This used to be done only for m/s collections. Doing it
4413 // always seemed a valid generalization. (DLD -- 6/00)
4414 vtable().verify(st);
4415 }
4416
4417 // Verify first subklass
4418 if (subklass() != nullptr) {
4419 guarantee(subklass()->is_klass(), "should be klass");
4420 }
4421
4422 // Verify siblings
4423 Klass* super = this->super();
4424 Klass* sib = next_sibling();
4425 if (sib != nullptr) {
4426 if (sib == this) {
4427 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4428 }
4429
4430 guarantee(sib->is_klass(), "should be klass");
4431 guarantee(sib->super() == super, "siblings should have same superklass");
4432 }
4433
4434 // Verify local interfaces
4435 if (local_interfaces()) {
4436 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4437 for (int j = 0; j < local_interfaces->length(); j++) {
4438 InstanceKlass* e = local_interfaces->at(j);
4439 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4440 }
4441 }
4442
4443 // Verify transitive interfaces
4444 if (transitive_interfaces() != nullptr) {
4445 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4446 for (int j = 0; j < transitive_interfaces->length(); j++) {
4447 InstanceKlass* e = transitive_interfaces->at(j);
4448 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4449 }
4450 }
4451
4452 // Verify methods
4453 if (methods() != nullptr) {
4454 Array<Method*>* methods = this->methods();
4455 for (int j = 0; j < methods->length(); j++) {
4456 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4457 }
4458 for (int j = 0; j < methods->length() - 1; j++) {
4459 Method* m1 = methods->at(j);
4460 Method* m2 = methods->at(j + 1);
4461 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4462 }
4463 }
4464
4465 // Verify method ordering
4466 if (method_ordering() != nullptr) {
4467 Array<int>* method_ordering = this->method_ordering();
4468 int length = method_ordering->length();
4469 if (JvmtiExport::can_maintain_original_method_order() ||
4470 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4471 guarantee(length == methods()->length(), "invalid method ordering length");
4472 jlong sum = 0;
4473 for (int j = 0; j < length; j++) {
4474 int original_index = method_ordering->at(j);
4475 guarantee(original_index >= 0, "invalid method ordering index");
4476 guarantee(original_index < length, "invalid method ordering index");
4477 sum += original_index;
4478 }
4479 // Verify sum of indices 0,1,...,length-1
4480 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4481 } else {
4482 guarantee(length == 0, "invalid method ordering length");
4483 }
4484 }
4485
4486 // Verify default methods
4487 if (default_methods() != nullptr) {
4488 Array<Method*>* methods = this->default_methods();
4489 for (int j = 0; j < methods->length(); j++) {
4490 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4491 }
4492 for (int j = 0; j < methods->length() - 1; j++) {
4493 Method* m1 = methods->at(j);
4494 Method* m2 = methods->at(j + 1);
4495 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4496 }
4497 }
4498
4499 // Verify JNI static field identifiers
4500 if (jni_ids() != nullptr) {
4501 jni_ids()->verify(this);
4502 }
4503
4504 // Verify other fields
4505 if (constants() != nullptr) {
4506 guarantee(constants()->is_constantPool(), "should be constant pool");
4507 }
4508 }
4509
4510 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4511 Klass::oop_verify_on(obj, st);
4512 VerifyFieldClosure blk;
4513 obj->oop_iterate(&blk);
4514 }
4515
4516
4517 // JNIid class for jfieldIDs only
4518 // Note to reviewers:
4519 // These JNI functions are just moved over to column 1 and not changed
4520 // in the compressed oops workspace.
4521 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4522 _holder = holder;
4523 _offset = offset;
4524 _next = next;
4525 debug_only(_is_static_field_id = false;)
4526 }
4527
4528
4529 JNIid* JNIid::find(int offset) {
4530 JNIid* current = this;
4531 while (current != nullptr) {
4532 if (current->offset() == offset) return current;
4533 current = current->next();
4534 }
4535 return nullptr;
4536 }
4537
4538 void JNIid::deallocate(JNIid* current) {
4539 while (current != nullptr) {
4540 JNIid* next = current->next();
4541 delete current;
4542 current = next;
4543 }
4544 }
4545
4546
4547 void JNIid::verify(Klass* holder) {
4548 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4549 int end_field_offset;
4550 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4551
4552 JNIid* current = this;
4553 while (current != nullptr) {
4554 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4555 #ifdef ASSERT
4556 int o = current->offset();
4557 if (current->is_static_field_id()) {
4558 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4559 }
4560 #endif
4561 current = current->next();
4562 }
4563 }
4564
4565 void InstanceKlass::set_init_state(ClassState state) {
4566 #ifdef ASSERT
4567 bool good_state = is_shared() ? (_init_state <= state)
4568 : (_init_state < state);
4569 assert(good_state || state == allocated, "illegal state transition");
4570 #endif
4571 assert(_init_thread == nullptr, "should be cleared before state change");
4572 Atomic::release_store(&_init_state, state);
4573 }
4574
4575 #if INCLUDE_JVMTI
4576
4577 // RedefineClasses() support for previous versions
4578
4579 // Globally, there is at least one previous version of a class to walk
4580 // during class unloading, which is saved because old methods in the class
4581 // are still running. Otherwise the previous version list is cleaned up.
4582 bool InstanceKlass::_should_clean_previous_versions = false;
4583
4584 // Returns true if there are previous versions of a class for class
4585 // unloading only. Also resets the flag to false. purge_previous_version
4586 // will set the flag to true if there are any left, i.e., if there's any
4587 // work to do for next time. This is to avoid the expensive code cache
4588 // walk in CLDG::clean_deallocate_lists().
4589 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4590 bool ret = _should_clean_previous_versions;
4591 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4592 ret ? "true" : "false");
4593 _should_clean_previous_versions = false;
4594 return ret;
4595 }
4596
4597 // This nulls out jmethodIDs for all methods in 'klass'
4598 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4599 // during class unloading.
4600 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4601 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4602 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4603 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4604 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4605 Array<Method*>* method_refs = klass->methods();
4606 for (int k = 0; k < method_refs->length(); k++) {
4607 Method* method = method_refs->at(k);
4608 if (method != nullptr && method->is_obsolete()) {
4609 method->clear_jmethod_id();
4610 }
4611 }
4612 }
4613
4614 // Purge previous versions before adding new previous versions of the class and
4615 // during class unloading.
4616 void InstanceKlass::purge_previous_version_list() {
4617 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4618 assert(has_been_redefined(), "Should only be called for main class");
4619
4620 // Quick exit.
4621 if (previous_versions() == nullptr) {
4622 return;
4623 }
4624
4625 // This klass has previous versions so see what we can cleanup
4626 // while it is safe to do so.
4627
4628 int deleted_count = 0; // leave debugging breadcrumbs
4629 int live_count = 0;
4630 ClassLoaderData* loader_data = class_loader_data();
4631 assert(loader_data != nullptr, "should never be null");
4632
4633 ResourceMark rm;
4634 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4635
4636 // previous versions are linked together through the InstanceKlass
4637 InstanceKlass* pv_node = previous_versions();
4638 InstanceKlass* last = this;
4639 int version = 0;
4640
4641 // check the previous versions list
4642 for (; pv_node != nullptr; ) {
4643
4644 ConstantPool* pvcp = pv_node->constants();
4645 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4646
4647 if (!pvcp->on_stack()) {
4648 // If the constant pool isn't on stack, none of the methods
4649 // are executing. Unlink this previous_version.
4650 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4651 // so will be deallocated during the next phase of class unloading.
4652 log_trace(redefine, class, iklass, purge)
4653 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4654 // Unlink from previous version list.
4655 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4656 InstanceKlass* next = pv_node->previous_versions();
4657 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4658 pv_node->link_previous_versions(nullptr); // point next to null
4659 last->link_previous_versions(next);
4660 // Delete this node directly. Nothing is referring to it and we don't
4661 // want it to increase the counter for metadata to delete in CLDG.
4662 MetadataFactory::free_metadata(loader_data, pv_node);
4663 pv_node = next;
4664 deleted_count++;
4665 version++;
4666 continue;
4667 } else {
4668 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4669 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4670 live_count++;
4671 if (pvcp->is_shared()) {
4672 // Shared previous versions can never be removed so no cleaning is needed.
4673 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4674 } else {
4675 // Previous version alive, set that clean is needed for next time.
4676 _should_clean_previous_versions = true;
4677 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4678 }
4679 }
4680
4681 // next previous version
4682 last = pv_node;
4683 pv_node = pv_node->previous_versions();
4684 version++;
4685 }
4686 log_trace(redefine, class, iklass, purge)
4687 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4688 }
4689
4690 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4691 int emcp_method_count) {
4692 int obsolete_method_count = old_methods->length() - emcp_method_count;
4693
4694 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4695 _previous_versions != nullptr) {
4696 // We have a mix of obsolete and EMCP methods so we have to
4697 // clear out any matching EMCP method entries the hard way.
4698 int local_count = 0;
4699 for (int i = 0; i < old_methods->length(); i++) {
4700 Method* old_method = old_methods->at(i);
4701 if (old_method->is_obsolete()) {
4702 // only obsolete methods are interesting
4703 Symbol* m_name = old_method->name();
4704 Symbol* m_signature = old_method->signature();
4705
4706 // previous versions are linked together through the InstanceKlass
4707 int j = 0;
4708 for (InstanceKlass* prev_version = _previous_versions;
4709 prev_version != nullptr;
4710 prev_version = prev_version->previous_versions(), j++) {
4711
4712 Array<Method*>* method_refs = prev_version->methods();
4713 for (int k = 0; k < method_refs->length(); k++) {
4714 Method* method = method_refs->at(k);
4715
4716 if (!method->is_obsolete() &&
4717 method->name() == m_name &&
4718 method->signature() == m_signature) {
4719 // The current RedefineClasses() call has made all EMCP
4720 // versions of this method obsolete so mark it as obsolete
4721 log_trace(redefine, class, iklass, add)
4722 ("%s(%s): flush obsolete method @%d in version @%d",
4723 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4724
4725 method->set_is_obsolete();
4726 break;
4727 }
4728 }
4729
4730 // The previous loop may not find a matching EMCP method, but
4731 // that doesn't mean that we can optimize and not go any
4732 // further back in the PreviousVersion generations. The EMCP
4733 // method for this generation could have already been made obsolete,
4734 // but there still may be an older EMCP method that has not
4735 // been made obsolete.
4736 }
4737
4738 if (++local_count >= obsolete_method_count) {
4739 // no more obsolete methods so bail out now
4740 break;
4741 }
4742 }
4743 }
4744 }
4745 }
4746
4747 // Save the scratch_class as the previous version if any of the methods are running.
4748 // The previous_versions are used to set breakpoints in EMCP methods and they are
4749 // also used to clean MethodData links to redefined methods that are no longer running.
4750 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4751 int emcp_method_count) {
4752 assert(Thread::current()->is_VM_thread(),
4753 "only VMThread can add previous versions");
4754
4755 ResourceMark rm;
4756 log_trace(redefine, class, iklass, add)
4757 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4758
4759 // Clean out old previous versions for this class
4760 purge_previous_version_list();
4761
4762 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4763 // a previous redefinition may be made obsolete by this redefinition.
4764 Array<Method*>* old_methods = scratch_class->methods();
4765 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4766
4767 // If the constant pool for this previous version of the class
4768 // is not marked as being on the stack, then none of the methods
4769 // in this previous version of the class are on the stack so
4770 // we don't need to add this as a previous version.
4771 ConstantPool* cp_ref = scratch_class->constants();
4772 if (!cp_ref->on_stack()) {
4773 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4774 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4775 return;
4776 }
4777
4778 // Add previous version if any methods are still running or if this is
4779 // a shared class which should never be removed.
4780 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4781 scratch_class->link_previous_versions(previous_versions());
4782 link_previous_versions(scratch_class);
4783 if (cp_ref->is_shared()) {
4784 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4785 } else {
4786 // We only set clean_previous_versions flag for processing during class
4787 // unloading for non-shared classes.
4788 _should_clean_previous_versions = true;
4789 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4790 }
4791 } // end add_previous_version()
4792
4793 #endif // INCLUDE_JVMTI
4794
4795 Method* InstanceKlass::method_with_idnum(int idnum) {
4796 Method* m = nullptr;
4797 if (idnum < methods()->length()) {
4798 m = methods()->at(idnum);
4799 }
4800 if (m == nullptr || m->method_idnum() != idnum) {
4801 for (int index = 0; index < methods()->length(); ++index) {
4802 m = methods()->at(index);
4803 if (m->method_idnum() == idnum) {
4804 return m;
4805 }
4806 }
4807 // None found, return null for the caller to handle.
4808 return nullptr;
4809 }
4810 return m;
4811 }
4812
4813
4814 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4815 if (idnum >= methods()->length()) {
4816 return nullptr;
4817 }
4818 Method* m = methods()->at(idnum);
4819 if (m != nullptr && m->orig_method_idnum() == idnum) {
4820 return m;
4821 }
4822 // Obsolete method idnum does not match the original idnum
4823 for (int index = 0; index < methods()->length(); ++index) {
4824 m = methods()->at(index);
4825 if (m->orig_method_idnum() == idnum) {
4826 return m;
4827 }
4828 }
4829 // None found, return null for the caller to handle.
4830 return nullptr;
4831 }
4832
4833
4834 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4835 InstanceKlass* holder = get_klass_version(version);
4836 if (holder == nullptr) {
4837 return nullptr; // The version of klass is gone, no method is found
4838 }
4839 Method* method = holder->method_with_orig_idnum(idnum);
4840 return method;
4841 }
4842
4843 #if INCLUDE_JVMTI
4844 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4845 return _cached_class_file;
4846 }
4847
4848 jint InstanceKlass::get_cached_class_file_len() {
4849 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4850 }
4851
4852 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4853 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4854 }
4855 #endif
4856
4857 // Make a step iterating over the class hierarchy under the root class.
4858 // Skips subclasses if requested.
4859 void ClassHierarchyIterator::next() {
4860 assert(_current != nullptr, "required");
4861 if (_visit_subclasses && _current->subklass() != nullptr) {
4862 _current = _current->subklass();
4863 return; // visit next subclass
4864 }
4865 _visit_subclasses = true; // reset
4866 while (_current->next_sibling() == nullptr && _current != _root) {
4867 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4868 }
4869 if (_current == _root) {
4870 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4871 _current = nullptr;
4872 return;
4873 }
4874 _current = _current->next_sibling();
4875 return; // visit next sibling subclass
4876 }