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 (is_runtime_setup_required()) {
935 // Need to take the slow path, which will call the runtimeSetup() function instead
936 // of <clinit>
937 initialize(CHECK);
938 return;
939 }
940 if (log_is_enabled(Info, aot, init)) {
941 ResourceMark rm;
942 log_info(aot, init)("%s (aot-inited)", external_name());
943 }
944
945 link_class(CHECK);
946
947 #ifdef ASSERT
948 {
949 Handle h_init_lock(THREAD, init_lock());
950 ObjectLocker ol(h_init_lock, THREAD);
951 assert(!is_initialized(), "sanity");
952 assert(!is_being_initialized(), "sanity");
953 assert(!is_in_error_state(), "sanity");
954 }
955 #endif
956
957 set_init_thread(THREAD);
958 set_initialization_state_and_notify(fully_initialized, CHECK);
959 }
960 #endif
961
962 bool InstanceKlass::verify_code(TRAPS) {
963 // 1) Verify the bytecodes
964 return Verifier::verify(this, should_verify_class(), THREAD);
965 }
966
967 void InstanceKlass::link_class(TRAPS) {
968 assert(is_loaded(), "must be loaded");
969 if (!is_linked()) {
970 link_class_impl(CHECK);
971 }
972 }
973
974 // Called to verify that a class can link during initialization, without
975 // throwing a VerifyError.
976 bool InstanceKlass::link_class_or_fail(TRAPS) {
977 assert(is_loaded(), "must be loaded");
978 if (!is_linked()) {
979 link_class_impl(CHECK_false);
980 }
981 return is_linked();
982 }
983
984 bool InstanceKlass::link_class_impl(TRAPS) {
985 if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
986 // This is for CDS static dump only -- we use the in_error_state to indicate that
987 // the class has failed verification. Throwing the NoClassDefFoundError here is just
988 // a convenient way to stop repeat attempts to verify the same (bad) class.
989 //
990 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
991 // if we are executing Java code. This is not a problem for CDS dumping phase since
992 // it doesn't execute any Java code.
993 ResourceMark rm(THREAD);
994 // Names are all known to be < 64k so we know this formatted message is not excessively large.
995 Exceptions::fthrow(THREAD_AND_LOCATION,
996 vmSymbols::java_lang_NoClassDefFoundError(),
997 "Class %s, or one of its supertypes, failed class initialization",
998 external_name());
999 return false;
1000 }
1001 // return if already verified
1002 if (is_linked()) {
1003 return true;
1004 }
1005
1006 // Timing
1007 // timer handles recursion
1008 JavaThread* jt = THREAD;
1009
1010 // link super class before linking this class
1011 Klass* super_klass = super();
1012 if (super_klass != nullptr) {
1013 if (super_klass->is_interface()) { // check if super class is an interface
1014 ResourceMark rm(THREAD);
1015 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1016 Exceptions::fthrow(
1017 THREAD_AND_LOCATION,
1018 vmSymbols::java_lang_IncompatibleClassChangeError(),
1019 "class %s has interface %s as super class",
1020 external_name(),
1021 super_klass->external_name()
1022 );
1023 return false;
1024 }
1025
1026 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
1027 ik_super->link_class_impl(CHECK_false);
1028 }
1029
1030 // link all interfaces implemented by this class before linking this class
1031 Array<InstanceKlass*>* interfaces = local_interfaces();
1032 int num_interfaces = interfaces->length();
1033 for (int index = 0; index < num_interfaces; index++) {
1034 InstanceKlass* interk = interfaces->at(index);
1035 interk->link_class_impl(CHECK_false);
1036 }
1037
1038
1039 // If a class declares a method that uses an inline class as an argument
1040 // type or return inline type, this inline class must be loaded during the
1041 // linking of this class because size and properties of the inline class
1042 // must be known in order to be able to perform inline type optimizations.
1043 // The implementation below is an approximation of this rule, the code
1044 // iterates over all methods of the current class (including overridden
1045 // methods), not only the methods declared by this class. This
1046 // approximation makes the code simpler, and doesn't change the semantic
1047 // because classes declaring methods overridden by the current class are
1048 // linked (and have performed their own pre-loading) before the linking
1049 // of the current class.
1050
1051
1052 // Note:
1053 // Inline class types are loaded during
1054 // the loading phase (see ClassFileParser::post_process_parsed_stream()).
1055 // Inline class types used as element types for array creation
1056 // are not pre-loaded. Their loading is triggered by either anewarray
1057 // or multianewarray bytecodes.
1058
1059 // Could it be possible to do the following processing only if the
1060 // class uses inline types?
1061 if (EnableValhalla) {
1062 ResourceMark rm(THREAD);
1063 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1064 if (fs.is_null_free_inline_type() && fs.access_flags().is_static()) {
1065 assert(fs.access_flags().is_strict(), "null-free fields must be strict");
1066 Symbol* sig = fs.signature();
1067 TempNewSymbol s = Signature::strip_envelope(sig);
1068 if (s != name()) {
1069 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());
1070 Klass* klass = SystemDictionary::resolve_or_fail(s,
1071 Handle(THREAD, class_loader()), true,
1072 CHECK_false);
1073 if (HAS_PENDING_EXCEPTION) {
1074 log_warning(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) failed: %s",
1075 s->as_C_string(), name()->as_C_string(), PENDING_EXCEPTION->klass()->name()->as_C_string());
1076 return false; // Exception is still pending
1077 }
1078 log_info(class, preload)("Preloading of class %s during linking of class %s (cause: null-free static field) succeeded",
1079 s->as_C_string(), name()->as_C_string());
1080 assert(klass != nullptr, "Sanity check");
1081 if (klass->is_abstract()) {
1082 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1083 err_msg("Class %s expects class %s to be concrete value class, but it is an abstract class",
1084 name()->as_C_string(),
1085 InstanceKlass::cast(klass)->external_name()), false);
1086 }
1087 if (!klass->is_inline_klass()) {
1088 THROW_MSG_(vmSymbols::java_lang_IncompatibleClassChangeError(),
1089 err_msg("class %s expects class %s to be a value class but it is an identity class",
1090 name()->as_C_string(), klass->external_name()), false);
1091 }
1092 InlineKlass* vk = InlineKlass::cast(klass);
1093 // the inline_type_field_klasses_array might have been loaded with CDS, so update only if not already set and check consistency
1094 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1095 if (li->klass() == nullptr) {
1096 li->set_klass(InlineKlass::cast(vk));
1097 li->set_kind(LayoutKind::REFERENCE);
1098 }
1099 assert(get_inline_type_field_klass(fs.index()) == vk, "Must match");
1100 } else {
1101 InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
1102 if (li->klass() == nullptr) {
1103 li->set_klass(InlineKlass::cast(this));
1104 li->set_kind(LayoutKind::REFERENCE);
1105 }
1106 assert(get_inline_type_field_klass(fs.index()) == this, "Must match");
1107 }
1108 }
1109 }
1110
1111 // Aggressively preloading all classes from the LoadableDescriptors attribute
1112 if (loadable_descriptors() != nullptr) {
1113 HandleMark hm(THREAD);
1114 for (int i = 0; i < loadable_descriptors()->length(); i++) {
1115 Symbol* sig = constants()->symbol_at(loadable_descriptors()->at(i));
1116 if (!Signature::has_envelope(sig)) continue;
1117 TempNewSymbol class_name = Signature::strip_envelope(sig);
1118 if (class_name == name()) continue;
1119 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());
1120 oop loader = class_loader();
1121 Klass* klass = SystemDictionary::resolve_or_null(class_name,
1122 Handle(THREAD, loader), THREAD);
1123 if (HAS_PENDING_EXCEPTION) {
1124 CLEAR_PENDING_EXCEPTION;
1125 }
1126 if (klass != nullptr) {
1127 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());
1128 if (!klass->is_inline_klass()) {
1129 // Non value class are allowed by the current spec, but it could be an indication of an issue so let's log a warning
1130 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());
1131 }
1132 } else {
1133 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());
1134 }
1135 }
1136 }
1137 }
1138
1139 // in case the class is linked in the process of linking its superclasses
1140 if (is_linked()) {
1141 return true;
1142 }
1143
1144 // trace only the link time for this klass that includes
1145 // the verification time
1146 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
1147 ClassLoader::perf_class_link_selftime(),
1148 ClassLoader::perf_classes_linked(),
1149 jt->get_thread_stat()->perf_recursion_counts_addr(),
1150 jt->get_thread_stat()->perf_timers_addr(),
1151 PerfClassTraceTime::CLASS_LINK);
1152
1153 // verification & rewriting
1154 {
1155 HandleMark hm(THREAD);
1156 Handle h_init_lock(THREAD, init_lock());
1157 ObjectLocker ol(h_init_lock, jt);
1158 // rewritten will have been set if loader constraint error found
1159 // on an earlier link attempt
1160 // don't verify or rewrite if already rewritten
1161 //
1162
1163 if (!is_linked()) {
1164 if (!is_rewritten()) {
1165 if (is_shared()) {
1166 assert(!verified_at_dump_time(), "must be");
1167 }
1168 {
1169 bool verify_ok = verify_code(THREAD);
1170 if (!verify_ok) {
1171 return false;
1172 }
1173 }
1174
1175 // Just in case a side-effect of verify linked this class already
1176 // (which can sometimes happen since the verifier loads classes
1177 // using custom class loaders, which are free to initialize things)
1178 if (is_linked()) {
1179 return true;
1180 }
1181
1182 // also sets rewritten
1183 rewrite_class(CHECK_false);
1184 } else if (is_shared()) {
1185 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1186 }
1187
1188 // relocate jsrs and link methods after they are all rewritten
1189 link_methods(CHECK_false);
1190
1191 // Initialize the vtable and interface table after
1192 // methods have been rewritten since rewrite may
1193 // fabricate new Method*s.
1194 // also does loader constraint checking
1195 //
1196 // initialize_vtable and initialize_itable need to be rerun
1197 // for a shared class if
1198 // 1) the class is loaded by custom class loader or
1199 // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1200 // 3) the class was not verified during dump time
1201 bool need_init_table = true;
1202 if (is_shared() && verified_at_dump_time() &&
1203 SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1204 need_init_table = false;
1205 }
1206 if (need_init_table) {
1207 vtable().initialize_vtable_and_check_constraints(CHECK_false);
1208 itable().initialize_itable_and_check_constraints(CHECK_false);
1209 }
1210 #ifdef ASSERT
1211 vtable().verify(tty, true);
1212 // In case itable verification is ever added.
1213 // itable().verify(tty, true);
1214 #endif
1215 if (Universe::is_fully_initialized()) {
1216 DeoptimizationScope deopt_scope;
1217 {
1218 // Now mark all code that assumes the class is not linked.
1219 // Set state under the Compile_lock also.
1220 MutexLocker ml(THREAD, Compile_lock);
1221
1222 set_init_state(linked);
1223 CodeCache::mark_dependents_on(&deopt_scope, this);
1224 }
1225 // Perform the deopt handshake outside Compile_lock.
1226 deopt_scope.deoptimize_marked();
1227 } else {
1228 set_init_state(linked);
1229 }
1230 if (JvmtiExport::should_post_class_prepare()) {
1231 JvmtiExport::post_class_prepare(THREAD, this);
1232 }
1233 }
1234 }
1235 return true;
1236 }
1237
1238 // Rewrite the byte codes of all of the methods of a class.
1239 // The rewriter must be called exactly once. Rewriting must happen after
1240 // verification but before the first method of the class is executed.
1241 void InstanceKlass::rewrite_class(TRAPS) {
1242 assert(is_loaded(), "must be loaded");
1243 if (is_rewritten()) {
1244 assert(is_shared(), "rewriting an unshared class?");
1245 return;
1246 }
1247 Rewriter::rewrite(this, CHECK);
1248 set_rewritten();
1249 }
1250
1251 // Now relocate and link method entry points after class is rewritten.
1252 // This is outside is_rewritten flag. In case of an exception, it can be
1253 // executed more than once.
1254 void InstanceKlass::link_methods(TRAPS) {
1255 PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1256
1257 int len = methods()->length();
1258 for (int i = len-1; i >= 0; i--) {
1259 methodHandle m(THREAD, methods()->at(i));
1260
1261 // Set up method entry points for compiler and interpreter .
1262 m->link_method(m, CHECK);
1263 }
1264 }
1265
1266 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1267 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1268 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1269 for (int i = 0; i < local_interfaces()->length(); ++i) {
1270 InstanceKlass* ik = local_interfaces()->at(i);
1271
1272 // Initialization is depth first search ie. we start with top of the inheritance tree
1273 // has_nonstatic_concrete_methods drives searching superinterfaces since it
1274 // means has_nonstatic_concrete_methods in its superinterface hierarchy
1275 if (ik->has_nonstatic_concrete_methods()) {
1276 ik->initialize_super_interfaces(CHECK);
1277 }
1278
1279 // Only initialize() interfaces that "declare" concrete methods.
1280 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1281 ik->initialize(CHECK);
1282 }
1283 }
1284 }
1285
1286 using InitializationErrorTable = ResourceHashtable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1287 static InitializationErrorTable* _initialization_error_table;
1288
1289 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1290 // Create the same exception with a message indicating the thread name,
1291 // and the StackTraceElements.
1292 Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1293 ResourceMark rm(current);
1294 if (init_error.is_null()) {
1295 log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1296
1297 // We failed to create the new exception, most likely due to either out-of-memory or
1298 // a stackoverflow error. If the original exception was either of those then we save
1299 // the shared, pre-allocated, stackless, instance of that exception.
1300 if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1301 log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1302 init_error = Handle(current, Universe::class_init_stack_overflow_error());
1303 } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1304 log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1305 init_error = Handle(current, Universe::class_init_out_of_memory_error());
1306 } else {
1307 return;
1308 }
1309 }
1310
1311 MutexLocker ml(current, ClassInitError_lock);
1312 OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1313 bool created;
1314 if (_initialization_error_table == nullptr) {
1315 _initialization_error_table = new (mtClass) InitializationErrorTable();
1316 }
1317 _initialization_error_table->put_if_absent(this, elem, &created);
1318 assert(created, "Initialization is single threaded");
1319 log_trace(class, init)("Initialization error added for class %s", external_name());
1320 }
1321
1322 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1323 MutexLocker ml(current, ClassInitError_lock);
1324 if (_initialization_error_table == nullptr) {
1325 return nullptr;
1326 }
1327 OopHandle* h = _initialization_error_table->get(this);
1328 return (h != nullptr) ? h->resolve() : nullptr;
1329 }
1330
1331 // Need to remove entries for unloaded classes.
1332 void InstanceKlass::clean_initialization_error_table() {
1333 struct InitErrorTableCleaner {
1334 bool do_entry(const InstanceKlass* ik, OopHandle h) {
1335 if (!ik->is_loader_alive()) {
1336 h.release(Universe::vm_global());
1337 return true;
1338 } else {
1339 return false;
1340 }
1341 }
1342 };
1343
1344 assert_locked_or_safepoint(ClassInitError_lock);
1345 InitErrorTableCleaner cleaner;
1346 if (_initialization_error_table != nullptr) {
1347 _initialization_error_table->unlink(&cleaner);
1348 }
1349 }
1350
1351 void InstanceKlass::initialize_impl(TRAPS) {
1352 HandleMark hm(THREAD);
1353
1354 // Make sure klass is linked (verified) before initialization
1355 // A class could already be verified, since it has been reflected upon.
1356 link_class(CHECK);
1357
1358 DTRACE_CLASSINIT_PROBE(required, -1);
1359
1360 bool wait = false;
1361
1362 JavaThread* jt = THREAD;
1363
1364 bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1365
1366 // refer to the JVM book page 47 for description of steps
1367 // Step 1
1368 {
1369 Handle h_init_lock(THREAD, init_lock());
1370 ObjectLocker ol(h_init_lock, jt);
1371
1372 // Step 2
1373 // If we were to use wait() instead of waitInterruptibly() then
1374 // we might end up throwing IE from link/symbol resolution sites
1375 // that aren't expected to throw. This would wreak havoc. See 6320309.
1376 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1377 if (debug_logging_enabled) {
1378 ResourceMark rm(jt);
1379 log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1380 jt->name(), external_name(), init_thread_name());
1381 }
1382 wait = true;
1383 jt->set_class_to_be_initialized(this);
1384 ol.wait_uninterruptibly(jt);
1385 jt->set_class_to_be_initialized(nullptr);
1386 }
1387
1388 // Step 3
1389 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1390 if (debug_logging_enabled) {
1391 ResourceMark rm(jt);
1392 log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1393 jt->name(), external_name());
1394 }
1395 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1396 return;
1397 }
1398
1399 // Step 4
1400 if (is_initialized()) {
1401 if (debug_logging_enabled) {
1402 ResourceMark rm(jt);
1403 log_debug(class, init)("Thread \"%s\" found %s already initialized",
1404 jt->name(), external_name());
1405 }
1406 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1407 return;
1408 }
1409
1410 // Step 5
1411 if (is_in_error_state()) {
1412 if (debug_logging_enabled) {
1413 ResourceMark rm(jt);
1414 log_debug(class, init)("Thread \"%s\" found %s is in error state",
1415 jt->name(), external_name());
1416 }
1417
1418 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1419 ResourceMark rm(THREAD);
1420 Handle cause(THREAD, get_initialization_error(THREAD));
1421
1422 stringStream ss;
1423 ss.print("Could not initialize class %s", external_name());
1424 if (cause.is_null()) {
1425 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1426 } else {
1427 THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1428 ss.as_string(), cause);
1429 }
1430 } else {
1431
1432 // Step 6
1433 set_init_state(being_initialized);
1434 set_init_thread(jt);
1435 if (debug_logging_enabled) {
1436 ResourceMark rm(jt);
1437 log_debug(class, init)("Thread \"%s\" is initializing %s",
1438 jt->name(), external_name());
1439 }
1440 }
1441 }
1442
1443 // Pre-allocating an all-zero value to be used to reset nullable flat storages
1444 if (is_inline_klass()) {
1445 InlineKlass* vk = InlineKlass::cast(this);
1446 if (vk->has_nullable_atomic_layout()) {
1447 oop val = vk->allocate_instance(THREAD);
1448 if (HAS_PENDING_EXCEPTION) {
1449 Handle e(THREAD, PENDING_EXCEPTION);
1450 CLEAR_PENDING_EXCEPTION;
1451 {
1452 EXCEPTION_MARK;
1453 add_initialization_error(THREAD, e);
1454 // Locks object, set state, and notify all waiting threads
1455 set_initialization_state_and_notify(initialization_error, THREAD);
1456 CLEAR_PENDING_EXCEPTION;
1457 }
1458 THROW_OOP(e());
1459 }
1460 vk->set_null_reset_value(val);
1461 }
1462 }
1463
1464 // Step 7
1465 // Next, if C is a class rather than an interface, initialize it's super class and super
1466 // interfaces.
1467 if (!is_interface()) {
1468 Klass* super_klass = super();
1469 if (super_klass != nullptr && super_klass->should_be_initialized()) {
1470 super_klass->initialize(THREAD);
1471 }
1472 // If C implements any interface that declares a non-static, concrete method,
1473 // the initialization of C triggers initialization of its super interfaces.
1474 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1475 // having a superinterface that declares, non-static, concrete methods
1476 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1477 initialize_super_interfaces(THREAD);
1478 }
1479
1480 // If any exceptions, complete abruptly, throwing the same exception as above.
1481 if (HAS_PENDING_EXCEPTION) {
1482 Handle e(THREAD, PENDING_EXCEPTION);
1483 CLEAR_PENDING_EXCEPTION;
1484 {
1485 EXCEPTION_MARK;
1486 add_initialization_error(THREAD, e);
1487 // Locks object, set state, and notify all waiting threads
1488 set_initialization_state_and_notify(initialization_error, THREAD);
1489 CLEAR_PENDING_EXCEPTION;
1490 }
1491 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1492 THROW_OOP(e());
1493 }
1494 }
1495
1496 // Step 8
1497 {
1498 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1499 if (class_initializer() != nullptr) {
1500 // Timer includes any side effects of class initialization (resolution,
1501 // etc), but not recursive entry into call_class_initializer().
1502 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1503 ClassLoader::perf_class_init_selftime(),
1504 ClassLoader::perf_classes_inited(),
1505 jt->get_thread_stat()->perf_recursion_counts_addr(),
1506 jt->get_thread_stat()->perf_timers_addr(),
1507 PerfClassTraceTime::CLASS_CLINIT);
1508 call_class_initializer(THREAD);
1509 } else {
1510 // The elapsed time is so small it's not worth counting.
1511 if (UsePerfData) {
1512 ClassLoader::perf_classes_inited()->inc();
1513 }
1514 call_class_initializer(THREAD);
1515 }
1516
1517 if (has_strict_static_fields() && !HAS_PENDING_EXCEPTION) {
1518 // Step 9 also verifies that strict static fields have been initialized.
1519 // Status bits were set in ClassFileParser::post_process_parsed_stream.
1520 // After <clinit>, bits must all be clear, or else we must throw an error.
1521 // This is an extremely fast check, so we won't bother with a timer.
1522 assert(fields_status() != nullptr, "");
1523 Symbol* bad_strict_static = nullptr;
1524 for (int index = 0; index < fields_status()->length(); index++) {
1525 // Very fast loop over single byte array looking for a set bit.
1526 if (fields_status()->adr_at(index)->is_strict_static_unset()) {
1527 // This strict static field has not been set by the class initializer.
1528 // Note that in the common no-error case, we read no field metadata.
1529 // We only unpack it when we need to report an error.
1530 FieldInfo fi = field(index);
1531 bad_strict_static = fi.name(constants());
1532 if (debug_logging_enabled) {
1533 ResourceMark rm(jt);
1534 const char* msg = format_strict_static_message(bad_strict_static);
1535 log_debug(class, init)("%s", msg);
1536 } else {
1537 // If we are not logging, do not bother to look for a second offense.
1538 break;
1539 }
1540 }
1541 }
1542 if (bad_strict_static != nullptr) {
1543 throw_strict_static_exception(bad_strict_static, "is unset after initialization of", THREAD);
1544 }
1545 }
1546 }
1547
1548 // Step 9
1549 if (!HAS_PENDING_EXCEPTION) {
1550 set_initialization_state_and_notify(fully_initialized, CHECK);
1551 DEBUG_ONLY(vtable().verify(tty, true);)
1552 }
1553 else {
1554 // Step 10 and 11
1555 Handle e(THREAD, PENDING_EXCEPTION);
1556 CLEAR_PENDING_EXCEPTION;
1557 // JVMTI has already reported the pending exception
1558 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1559 JvmtiExport::clear_detected_exception(jt);
1560 {
1561 EXCEPTION_MARK;
1562 add_initialization_error(THREAD, e);
1563 set_initialization_state_and_notify(initialization_error, THREAD);
1564 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1565 // JVMTI has already reported the pending exception
1566 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1567 JvmtiExport::clear_detected_exception(jt);
1568 }
1569 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1570 if (e->is_a(vmClasses::Error_klass())) {
1571 THROW_OOP(e());
1572 } else {
1573 JavaCallArguments args(e);
1574 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1575 vmSymbols::throwable_void_signature(),
1576 &args);
1577 }
1578 }
1579 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1580 }
1581
1582
1583 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1584 Handle h_init_lock(THREAD, init_lock());
1585 if (h_init_lock() != nullptr) {
1586 ObjectLocker ol(h_init_lock, THREAD);
1587 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1588 set_init_state(state);
1589 fence_and_clear_init_lock();
1590 ol.notify_all(CHECK);
1591 } else {
1592 assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1593 set_init_thread(nullptr); // reset _init_thread before changing _init_state
1594 set_init_state(state);
1595 }
1596 }
1597
1598 void InstanceKlass::notify_strict_static_access(int field_index, bool is_writing, TRAPS) {
1599 guarantee(field_index >= 0 && field_index < fields_status()->length(), "valid field index");
1600 DEBUG_ONLY(FieldInfo debugfi = field(field_index));
1601 assert(debugfi.access_flags().is_strict(), "");
1602 assert(debugfi.access_flags().is_static(), "");
1603 FieldStatus& fs = *fields_status()->adr_at(field_index);
1604 LogTarget(Trace, class, init) lt;
1605 if (lt.is_enabled()) {
1606 ResourceMark rm(THREAD);
1607 LogStream ls(lt);
1608 FieldInfo fi = field(field_index);
1609 ls.print("notify %s %s %s%s ",
1610 external_name(), is_writing? "Write" : "Read",
1611 fs.is_strict_static_unset() ? "Unset" : "(set)",
1612 fs.is_strict_static_unread() ? "+Unread" : "");
1613 fi.print(&ls, constants());
1614 }
1615 if (fs.is_strict_static_unset()) {
1616 assert(fs.is_strict_static_unread(), "ClassFileParser resp.");
1617 // If it is not set, there are only two reasonable things we can do here:
1618 // - mark it set if this is putstatic
1619 // - throw an error (Read-Before-Write) if this is getstatic
1620
1621 // The unset state is (or should be) transient, and observable only in one
1622 // thread during the execution of <clinit>. Something is wrong here as this
1623 // should not be possible
1624 guarantee(is_reentrant_initialization(THREAD), "unscoped access to strict static");
1625 if (is_writing) {
1626 // clear the "unset" bit, since the field is actually going to be written
1627 fs.update_strict_static_unset(false);
1628 } else {
1629 // throw an IllegalStateException, since we are reading before writing
1630 // see also InstanceKlass::initialize_impl, Step 8 (at end)
1631 Symbol* bad_strict_static = field(field_index).name(constants());
1632 throw_strict_static_exception(bad_strict_static, "is unset before first read in", CHECK);
1633 }
1634 } else {
1635 // Ensure no write after read for final strict statics
1636 FieldInfo fi = field(field_index);
1637 bool is_final = fi.access_flags().is_final();
1638 if (is_final) {
1639 // no final write after read, so observing a constant freezes it, as if <clinit> ended early
1640 // (maybe we could trust the constant a little earlier, before <clinit> ends)
1641 if (is_writing && !fs.is_strict_static_unread()) {
1642 Symbol* bad_strict_static = fi.name(constants());
1643 throw_strict_static_exception(bad_strict_static, "is set after read (as final) in", CHECK);
1644 } else if (!is_writing && fs.is_strict_static_unread()) {
1645 fs.update_strict_static_unread(false);
1646 }
1647 }
1648 }
1649 }
1650
1651 void InstanceKlass::throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS) {
1652 ResourceMark rm(THREAD);
1653 const char* msg = format_strict_static_message(field_name, when);
1654 THROW_MSG(vmSymbols::java_lang_IllegalStateException(), msg);
1655 }
1656
1657 const char* InstanceKlass::format_strict_static_message(Symbol* field_name, const char* when) {
1658 stringStream ss;
1659 ss.print("Strict static \"%s\" %s %s",
1660 field_name->as_C_string(),
1661 when == nullptr ? "is unset in" : when,
1662 external_name());
1663 return ss.as_string();
1664 }
1665
1666 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1667 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1668 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1669 assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1670
1671 DeoptimizationScope deopt_scope;
1672 {
1673 MutexLocker ml(current, Compile_lock);
1674
1675 set_init_state(InstanceKlass::loaded);
1676 // make sure init_state store is already done.
1677 // The compiler reads the hierarchy outside of the Compile_lock.
1678 // Access ordering is used to add to hierarchy.
1679
1680 // Link into hierarchy.
1681 append_to_sibling_list(); // add to superklass/sibling list
1682 process_interfaces(); // handle all "implements" declarations
1683
1684 // Now mark all code that depended on old class hierarchy.
1685 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1686 if (Universe::is_fully_initialized()) {
1687 CodeCache::mark_dependents_on(&deopt_scope, this);
1688 }
1689 }
1690 // Perform the deopt handshake outside Compile_lock.
1691 deopt_scope.deoptimize_marked();
1692 }
1693
1694
1695 InstanceKlass* InstanceKlass::implementor() const {
1696 InstanceKlass* volatile* ik = adr_implementor();
1697 if (ik == nullptr) {
1698 return nullptr;
1699 } else {
1700 // This load races with inserts, and therefore needs acquire.
1701 InstanceKlass* ikls = Atomic::load_acquire(ik);
1702 if (ikls != nullptr && !ikls->is_loader_alive()) {
1703 return nullptr; // don't return unloaded class
1704 } else {
1705 return ikls;
1706 }
1707 }
1708 }
1709
1710
1711 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1712 assert_locked_or_safepoint(Compile_lock);
1713 assert(is_interface(), "not interface");
1714 InstanceKlass* volatile* addr = adr_implementor();
1715 assert(addr != nullptr, "null addr");
1716 if (addr != nullptr) {
1717 Atomic::release_store(addr, ik);
1718 }
1719 }
1720
1721 int InstanceKlass::nof_implementors() const {
1722 InstanceKlass* ik = implementor();
1723 if (ik == nullptr) {
1724 return 0;
1725 } else if (ik != this) {
1726 return 1;
1727 } else {
1728 return 2;
1729 }
1730 }
1731
1732 // The embedded _implementor field can only record one implementor.
1733 // When there are more than one implementors, the _implementor field
1734 // is set to the interface Klass* itself. Following are the possible
1735 // values for the _implementor field:
1736 // null - no implementor
1737 // implementor Klass* - one implementor
1738 // self - more than one implementor
1739 //
1740 // The _implementor field only exists for interfaces.
1741 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1742 if (Universe::is_fully_initialized()) {
1743 assert_lock_strong(Compile_lock);
1744 }
1745 assert(is_interface(), "not interface");
1746 // Filter out my subinterfaces.
1747 // (Note: Interfaces are never on the subklass list.)
1748 if (ik->is_interface()) return;
1749
1750 // Filter out subclasses whose supers already implement me.
1751 // (Note: CHA must walk subclasses of direct implementors
1752 // in order to locate indirect implementors.)
1753 InstanceKlass* super_ik = ik->java_super();
1754 if (super_ik != nullptr && super_ik->implements_interface(this))
1755 // We only need to check one immediate superclass, since the
1756 // implements_interface query looks at transitive_interfaces.
1757 // Any supers of the super have the same (or fewer) transitive_interfaces.
1758 return;
1759
1760 InstanceKlass* iklass = implementor();
1761 if (iklass == nullptr) {
1762 set_implementor(ik);
1763 } else if (iklass != this && iklass != ik) {
1764 // There is already an implementor. Use itself as an indicator of
1765 // more than one implementors.
1766 set_implementor(this);
1767 }
1768
1769 // The implementor also implements the transitive_interfaces
1770 for (int index = 0; index < local_interfaces()->length(); index++) {
1771 local_interfaces()->at(index)->add_implementor(ik);
1772 }
1773 }
1774
1775 void InstanceKlass::init_implementor() {
1776 if (is_interface()) {
1777 set_implementor(nullptr);
1778 }
1779 }
1780
1781
1782 void InstanceKlass::process_interfaces() {
1783 // link this class into the implementors list of every interface it implements
1784 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1785 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1786 InstanceKlass* interf = local_interfaces()->at(i);
1787 assert(interf->is_interface(), "expected interface");
1788 interf->add_implementor(this);
1789 }
1790 }
1791
1792 bool InstanceKlass::can_be_primary_super_slow() const {
1793 if (is_interface())
1794 return false;
1795 else
1796 return Klass::can_be_primary_super_slow();
1797 }
1798
1799 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1800 Array<InstanceKlass*>* transitive_interfaces) {
1801 // The secondaries are the implemented interfaces.
1802 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1803 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1804 Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1805 int num_secondaries = num_extra_slots + interfaces->length();
1806 if (num_secondaries == 0) {
1807 // Must share this for correct bootstrapping!
1808 set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1809 return nullptr;
1810 } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1811 // We will reuse the transitive interfaces list if we're certain
1812 // it's in hash order.
1813 uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1814 set_secondary_supers(interfaces, bitmap);
1815 return nullptr;
1816 }
1817 // Copy transitive interfaces to a temporary growable array to be constructed
1818 // into the secondary super list with extra slots.
1819 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1820 for (int i = 0; i < interfaces->length(); i++) {
1821 secondaries->push(interfaces->at(i));
1822 }
1823 return secondaries;
1824 }
1825
1826 bool InstanceKlass::implements_interface(Klass* k) const {
1827 if (this == k) return true;
1828 assert(k->is_interface(), "should be an interface class");
1829 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1830 if (transitive_interfaces()->at(i) == k) {
1831 return true;
1832 }
1833 }
1834 return false;
1835 }
1836
1837 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1838 // Verify direct super interface
1839 if (this == k) return true;
1840 assert(k->is_interface(), "should be an interface class");
1841 for (int i = 0; i < local_interfaces()->length(); i++) {
1842 if (local_interfaces()->at(i) == k) {
1843 return true;
1844 }
1845 }
1846 return false;
1847 }
1848
1849 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1850 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1851 size_t size = objArrayOopDesc::object_size(length);
1852 ArrayKlass* ak = array_klass(n, CHECK_NULL);
1853 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1854 /* do_zero */ true, CHECK_NULL);
1855 return o;
1856 }
1857
1858 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1859 if (TraceFinalizerRegistration) {
1860 tty->print("Registered ");
1861 i->print_value_on(tty);
1862 tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1863 }
1864 instanceHandle h_i(THREAD, i);
1865 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1866 JavaValue result(T_VOID);
1867 JavaCallArguments args(h_i);
1868 methodHandle mh(THREAD, Universe::finalizer_register_method());
1869 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1870 MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1871 return h_i();
1872 }
1873
1874 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1875 assert(!is_abstract() && !is_interface(), "Should not create this object");
1876 size_t size = size_helper(); // Query before forming handle.
1877 return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1878 }
1879
1880 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1881 Klass* k = java_lang_Class::as_Klass(java_class);
1882 if (k == nullptr) {
1883 ResourceMark rm(THREAD);
1884 THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1885 }
1886 InstanceKlass* ik = cast(k);
1887 ik->check_valid_for_instantiation(false, CHECK_NULL);
1888 ik->initialize(CHECK_NULL);
1889 return ik->allocate_instance(THREAD);
1890 }
1891
1892 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1893 return instanceHandle(THREAD, allocate_instance(THREAD));
1894 }
1895
1896 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1897 if (is_interface() || is_abstract()) {
1898 ResourceMark rm(THREAD);
1899 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1900 : vmSymbols::java_lang_InstantiationException(), external_name());
1901 }
1902 if (this == vmClasses::Class_klass()) {
1903 ResourceMark rm(THREAD);
1904 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1905 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1906 }
1907 }
1908
1909 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1910 // Need load-acquire for lock-free read
1911 if (array_klasses_acquire() == nullptr) {
1912
1913 // Recursively lock array allocation
1914 RecursiveLocker rl(MultiArray_lock, THREAD);
1915
1916 // Check if another thread created the array klass while we were waiting for the lock.
1917 if (array_klasses() == nullptr) {
1918 ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, false, CHECK_NULL);
1919 // use 'release' to pair with lock-free load
1920 release_set_array_klasses(k);
1921 }
1922 }
1923
1924 // array_klasses() will always be set at this point
1925 ArrayKlass* ak = array_klasses();
1926 assert(ak != nullptr, "should be set");
1927 return ak->array_klass(n, THREAD);
1928 }
1929
1930 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1931 // Need load-acquire for lock-free read
1932 ArrayKlass* ak = array_klasses_acquire();
1933 if (ak == nullptr) {
1934 return nullptr;
1935 } else {
1936 return ak->array_klass_or_null(n);
1937 }
1938 }
1939
1940 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1941 return array_klass(1, THREAD);
1942 }
1943
1944 ArrayKlass* InstanceKlass::array_klass_or_null() {
1945 return array_klass_or_null(1);
1946 }
1947
1948 static int call_class_initializer_counter = 0; // for debugging
1949
1950 Method* InstanceKlass::class_initializer() const {
1951 Method* clinit = find_method(
1952 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1953 if (clinit != nullptr && clinit->is_class_initializer()) {
1954 return clinit;
1955 }
1956 return nullptr;
1957 }
1958
1959 void InstanceKlass::call_class_initializer(TRAPS) {
1960 if (ReplayCompiles &&
1961 (ReplaySuppressInitializers == 1 ||
1962 (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1963 // Hide the existence of the initializer for the purpose of replaying the compile
1964 return;
1965 }
1966
1967 #if INCLUDE_CDS
1968 // This is needed to ensure the consistency of the archived heap objects.
1969 if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1970 AOTClassInitializer::call_runtime_setup(THREAD, this);
1971 return;
1972 } else if (has_archived_enum_objs()) {
1973 assert(is_shared(), "must be");
1974 bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1975 if (initialized) {
1976 return;
1977 }
1978 }
1979 #endif
1980
1981 methodHandle h_method(THREAD, class_initializer());
1982 assert(!is_initialized(), "we cannot initialize twice");
1983 LogTarget(Info, class, init) lt;
1984 if (lt.is_enabled()) {
1985 ResourceMark rm(THREAD);
1986 LogStream ls(lt);
1987 ls.print("%d Initializing ", call_class_initializer_counter++);
1988 name()->print_value_on(&ls);
1989 ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1990 h_method() == nullptr ? "(no method)" : "", p2i(this),
1991 THREAD->name());
1992 }
1993 if (h_method() != nullptr) {
1994 ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1995 JavaCallArguments args; // No arguments
1996 JavaValue result(T_VOID);
1997 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1998 }
1999 }
2000
2001 // If a class that implements this interface is initialized, is the JVM required
2002 // to first execute a <clinit> method declared in this interface,
2003 // or (if also_check_supers==true) any of the super types of this interface?
2004 //
2005 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
2006 // an interface, then let SC be its superclass and let SI1, ..., SIn
2007 // be all superinterfaces of C (whether direct or indirect) that
2008 // declare at least one non-abstract, non-static method.
2009 //
2010 // So when an interface is initialized, it does not look at its
2011 // supers. But a proper class will ensure that all of its supers have
2012 // run their <clinit> methods, except that it disregards interfaces
2013 // that lack a non-static concrete method (i.e., a default method).
2014 // Therefore, you should probably call this method only when the
2015 // current class is a super of some proper class, not an interface.
2016 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
2017 assert(is_interface(), "must be");
2018
2019 if (!has_nonstatic_concrete_methods()) {
2020 // quick check: no nonstatic concrete methods are declared by this or any super interfaces
2021 return false;
2022 }
2023
2024 // JVMS 5.5. Initialization
2025 // ...If C is an interface that declares a non-abstract,
2026 // non-static method, the initialization of a class that
2027 // implements C directly or indirectly.
2028 if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
2029 return true;
2030 }
2031 if (also_check_supers) {
2032 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2033 for (int i = 0; i < all_ifs->length(); ++i) {
2034 InstanceKlass* super_intf = all_ifs->at(i);
2035 if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
2036 return true;
2037 }
2038 }
2039 }
2040 return false;
2041 }
2042
2043 void InstanceKlass::mask_for(const methodHandle& method, int bci,
2044 InterpreterOopMap* entry_for) {
2045 // Lazily create the _oop_map_cache at first request.
2046 // Load_acquire is needed to safely get instance published with CAS by another thread.
2047 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
2048 if (oop_map_cache == nullptr) {
2049 // Try to install new instance atomically.
2050 oop_map_cache = new OopMapCache();
2051 OopMapCache* other = Atomic::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
2052 if (other != nullptr) {
2053 // Someone else managed to install before us, ditch local copy and use the existing one.
2054 delete oop_map_cache;
2055 oop_map_cache = other;
2056 }
2057 }
2058 // _oop_map_cache is constant after init; lookup below does its own locking.
2059 oop_map_cache->lookup(method, bci, entry_for);
2060 }
2061
2062
2063 FieldInfo InstanceKlass::field(int index) const {
2064 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2065 if (fs.index() == index) {
2066 return fs.to_FieldInfo();
2067 }
2068 }
2069 fatal("Field not found");
2070 return FieldInfo();
2071 }
2072
2073 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2074 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2075 Symbol* f_name = fs.name();
2076 Symbol* f_sig = fs.signature();
2077 if (f_name == name && f_sig == sig) {
2078 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2079 return true;
2080 }
2081 }
2082 return false;
2083 }
2084
2085
2086 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2087 const int n = local_interfaces()->length();
2088 for (int i = 0; i < n; i++) {
2089 Klass* intf1 = local_interfaces()->at(i);
2090 assert(intf1->is_interface(), "just checking type");
2091 // search for field in current interface
2092 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
2093 assert(fd->is_static(), "interface field must be static");
2094 return intf1;
2095 }
2096 // search for field in direct superinterfaces
2097 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
2098 if (intf2 != nullptr) return intf2;
2099 }
2100 // otherwise field lookup fails
2101 return nullptr;
2102 }
2103
2104
2105 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
2106 // search order according to newest JVM spec (5.4.3.2, p.167).
2107 // 1) search for field in current klass
2108 if (find_local_field(name, sig, fd)) {
2109 return const_cast<InstanceKlass*>(this);
2110 }
2111 // 2) search for field recursively in direct superinterfaces
2112 { Klass* intf = find_interface_field(name, sig, fd);
2113 if (intf != nullptr) return intf;
2114 }
2115 // 3) apply field lookup recursively if superclass exists
2116 { Klass* supr = super();
2117 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
2118 }
2119 // 4) otherwise field lookup fails
2120 return nullptr;
2121 }
2122
2123
2124 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
2125 // search order according to newest JVM spec (5.4.3.2, p.167).
2126 // 1) search for field in current klass
2127 if (find_local_field(name, sig, fd)) {
2128 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
2129 }
2130 // 2) search for field recursively in direct superinterfaces
2131 if (is_static) {
2132 Klass* intf = find_interface_field(name, sig, fd);
2133 if (intf != nullptr) return intf;
2134 }
2135 // 3) apply field lookup recursively if superclass exists
2136 { Klass* supr = super();
2137 if (supr != nullptr) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
2138 }
2139 // 4) otherwise field lookup fails
2140 return nullptr;
2141 }
2142
2143 bool InstanceKlass::contains_field_offset(int offset) {
2144 if (this->is_inline_klass()) {
2145 InlineKlass* vk = InlineKlass::cast(this);
2146 return offset >= vk->payload_offset() && offset < (vk->payload_offset() + vk->payload_size_in_bytes());
2147 } else {
2148 fieldDescriptor fd;
2149 return find_field_from_offset(offset, false, &fd);
2150 }
2151 }
2152
2153 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2154 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2155 if (fs.offset() == offset) {
2156 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
2157 if (fd->is_static() == is_static) return true;
2158 }
2159 }
2160 return false;
2161 }
2162
2163
2164 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
2165 Klass* klass = const_cast<InstanceKlass*>(this);
2166 while (klass != nullptr) {
2167 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
2168 return true;
2169 }
2170 klass = klass->super();
2171 }
2172 return false;
2173 }
2174
2175
2176 void InstanceKlass::methods_do(void f(Method* method)) {
2177 // Methods aren't stable until they are loaded. This can be read outside
2178 // a lock through the ClassLoaderData for profiling
2179 // Redefined scratch classes are on the list and need to be cleaned
2180 if (!is_loaded() && !is_scratch_class()) {
2181 return;
2182 }
2183
2184 int len = methods()->length();
2185 for (int index = 0; index < len; index++) {
2186 Method* m = methods()->at(index);
2187 assert(m->is_method(), "must be method");
2188 f(m);
2189 }
2190 }
2191
2192
2193 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
2194 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2195 if (fs.access_flags().is_static()) {
2196 fieldDescriptor& fd = fs.field_descriptor();
2197 cl->do_field(&fd);
2198 }
2199 }
2200 }
2201
2202
2203 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
2204 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2205 if (fs.access_flags().is_static()) {
2206 fieldDescriptor& fd = fs.field_descriptor();
2207 f(&fd, mirror, CHECK);
2208 }
2209 }
2210 }
2211
2212 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
2213 InstanceKlass* super = superklass();
2214 if (super != nullptr) {
2215 super->do_nonstatic_fields(cl);
2216 }
2217 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
2218 fieldDescriptor& fd = fs.field_descriptor();
2219 if (!fd.is_static()) {
2220 cl->do_field(&fd);
2221 }
2222 }
2223 }
2224
2225 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
2226 return a->offset() - b->offset();
2227 }
2228
2229 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
2230 InstanceKlass* super = superklass();
2231 if (super != nullptr) {
2232 super->print_nonstatic_fields(cl);
2233 }
2234 ResourceMark rm;
2235 // In DebugInfo nonstatic fields are sorted by offset.
2236 GrowableArray<FieldInfo> fields_sorted;
2237 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
2238 if (!fs.access_flags().is_static()) {
2239 fields_sorted.push(fs.to_FieldInfo());
2240 }
2241 }
2242 int length = fields_sorted.length();
2243 if (length > 0) {
2244 fields_sorted.sort(compare_fields_by_offset);
2245 fieldDescriptor fd;
2246 for (int i = 0; i < length; i++) {
2247 fd.reinitialize(this, fields_sorted.at(i));
2248 assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
2249 cl->do_field(&fd);
2250 }
2251 }
2252 }
2253
2254 #ifdef ASSERT
2255 static int linear_search(const Array<Method*>* methods,
2256 const Symbol* name,
2257 const Symbol* signature) {
2258 const int len = methods->length();
2259 for (int index = 0; index < len; index++) {
2260 const Method* const m = methods->at(index);
2261 assert(m->is_method(), "must be method");
2262 if (m->signature() == signature && m->name() == name) {
2263 return index;
2264 }
2265 }
2266 return -1;
2267 }
2268 #endif
2269
2270 bool InstanceKlass::_disable_method_binary_search = false;
2271
2272 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2273 int len = methods->length();
2274 int l = 0;
2275 int h = len - 1;
2276 while (l <= h) {
2277 Method* m = methods->at(l);
2278 if (m->name() == name) {
2279 return l;
2280 }
2281 l++;
2282 }
2283 return -1;
2284 }
2285
2286 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2287 if (_disable_method_binary_search) {
2288 assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2289 // At the final stage of dynamic dumping, the methods array may not be sorted
2290 // by ascending addresses of their names, so we can't use binary search anymore.
2291 // However, methods with the same name are still laid out consecutively inside the
2292 // methods array, so let's look for the first one that matches.
2293 return linear_search(methods, name);
2294 }
2295
2296 int len = methods->length();
2297 int l = 0;
2298 int h = len - 1;
2299
2300 // methods are sorted by ascending addresses of their names, so do binary search
2301 while (l <= h) {
2302 int mid = (l + h) >> 1;
2303 Method* m = methods->at(mid);
2304 assert(m->is_method(), "must be method");
2305 int res = m->name()->fast_compare(name);
2306 if (res == 0) {
2307 return mid;
2308 } else if (res < 0) {
2309 l = mid + 1;
2310 } else {
2311 h = mid - 1;
2312 }
2313 }
2314 return -1;
2315 }
2316
2317 // find_method looks up the name/signature in the local methods array
2318 Method* InstanceKlass::find_method(const Symbol* name,
2319 const Symbol* signature) const {
2320 return find_method_impl(name, signature,
2321 OverpassLookupMode::find,
2322 StaticLookupMode::find,
2323 PrivateLookupMode::find);
2324 }
2325
2326 Method* InstanceKlass::find_method_impl(const Symbol* name,
2327 const Symbol* signature,
2328 OverpassLookupMode overpass_mode,
2329 StaticLookupMode static_mode,
2330 PrivateLookupMode private_mode) const {
2331 return InstanceKlass::find_method_impl(methods(),
2332 name,
2333 signature,
2334 overpass_mode,
2335 static_mode,
2336 private_mode);
2337 }
2338
2339 // find_instance_method looks up the name/signature in the local methods array
2340 // and skips over static methods
2341 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2342 const Symbol* name,
2343 const Symbol* signature,
2344 PrivateLookupMode private_mode) {
2345 Method* const meth = InstanceKlass::find_method_impl(methods,
2346 name,
2347 signature,
2348 OverpassLookupMode::find,
2349 StaticLookupMode::skip,
2350 private_mode);
2351 assert(((meth == nullptr) || !meth->is_static()),
2352 "find_instance_method should have skipped statics");
2353 return meth;
2354 }
2355
2356 // find_instance_method looks up the name/signature in the local methods array
2357 // and skips over static methods
2358 Method* InstanceKlass::find_instance_method(const Symbol* name,
2359 const Symbol* signature,
2360 PrivateLookupMode private_mode) const {
2361 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2362 }
2363
2364 // Find looks up the name/signature in the local methods array
2365 // and filters on the overpass, static and private flags
2366 // This returns the first one found
2367 // note that the local methods array can have up to one overpass, one static
2368 // and one instance (private or not) with the same name/signature
2369 Method* InstanceKlass::find_local_method(const Symbol* name,
2370 const Symbol* signature,
2371 OverpassLookupMode overpass_mode,
2372 StaticLookupMode static_mode,
2373 PrivateLookupMode private_mode) const {
2374 return InstanceKlass::find_method_impl(methods(),
2375 name,
2376 signature,
2377 overpass_mode,
2378 static_mode,
2379 private_mode);
2380 }
2381
2382 // Find looks up the name/signature in the local methods array
2383 // and filters on the overpass, static and private flags
2384 // This returns the first one found
2385 // note that the local methods array can have up to one overpass, one static
2386 // and one instance (private or not) with the same name/signature
2387 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2388 const Symbol* name,
2389 const Symbol* signature,
2390 OverpassLookupMode overpass_mode,
2391 StaticLookupMode static_mode,
2392 PrivateLookupMode private_mode) {
2393 return InstanceKlass::find_method_impl(methods,
2394 name,
2395 signature,
2396 overpass_mode,
2397 static_mode,
2398 private_mode);
2399 }
2400
2401 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2402 const Symbol* name,
2403 const Symbol* signature) {
2404 return InstanceKlass::find_method_impl(methods,
2405 name,
2406 signature,
2407 OverpassLookupMode::find,
2408 StaticLookupMode::find,
2409 PrivateLookupMode::find);
2410 }
2411
2412 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2413 const Symbol* name,
2414 const Symbol* signature,
2415 OverpassLookupMode overpass_mode,
2416 StaticLookupMode static_mode,
2417 PrivateLookupMode private_mode) {
2418 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2419 return hit >= 0 ? methods->at(hit): nullptr;
2420 }
2421
2422 // true if method matches signature and conforms to skipping_X conditions.
2423 static bool method_matches(const Method* m,
2424 const Symbol* signature,
2425 bool skipping_overpass,
2426 bool skipping_static,
2427 bool skipping_private) {
2428 return ((m->signature() == signature) &&
2429 (!skipping_overpass || !m->is_overpass()) &&
2430 (!skipping_static || !m->is_static()) &&
2431 (!skipping_private || !m->is_private()));
2432 }
2433
2434 // Used directly for default_methods to find the index into the
2435 // default_vtable_indices, and indirectly by find_method
2436 // find_method_index looks in the local methods array to return the index
2437 // of the matching name/signature. If, overpass methods are being ignored,
2438 // the search continues to find a potential non-overpass match. This capability
2439 // is important during method resolution to prefer a static method, for example,
2440 // over an overpass method.
2441 // There is the possibility in any _method's array to have the same name/signature
2442 // for a static method, an overpass method and a local instance method
2443 // To correctly catch a given method, the search criteria may need
2444 // to explicitly skip the other two. For local instance methods, it
2445 // is often necessary to skip private methods
2446 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2447 const Symbol* name,
2448 const Symbol* signature,
2449 OverpassLookupMode overpass_mode,
2450 StaticLookupMode static_mode,
2451 PrivateLookupMode private_mode) {
2452 const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2453 const bool skipping_static = (static_mode == StaticLookupMode::skip);
2454 const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2455 const int hit = quick_search(methods, name);
2456 if (hit != -1) {
2457 const Method* const m = methods->at(hit);
2458
2459 // Do linear search to find matching signature. First, quick check
2460 // for common case, ignoring overpasses if requested.
2461 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2462 return hit;
2463 }
2464
2465 // search downwards through overloaded methods
2466 int i;
2467 for (i = hit - 1; i >= 0; --i) {
2468 const Method* const m = methods->at(i);
2469 assert(m->is_method(), "must be method");
2470 if (m->name() != name) {
2471 break;
2472 }
2473 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2474 return i;
2475 }
2476 }
2477 // search upwards
2478 for (i = hit + 1; i < methods->length(); ++i) {
2479 const Method* const m = methods->at(i);
2480 assert(m->is_method(), "must be method");
2481 if (m->name() != name) {
2482 break;
2483 }
2484 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2485 return i;
2486 }
2487 }
2488 // not found
2489 #ifdef ASSERT
2490 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2491 linear_search(methods, name, signature);
2492 assert(-1 == index, "binary search should have found entry %d", index);
2493 #endif
2494 }
2495 return -1;
2496 }
2497
2498 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2499 return find_method_by_name(methods(), name, end);
2500 }
2501
2502 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2503 const Symbol* name,
2504 int* end_ptr) {
2505 assert(end_ptr != nullptr, "just checking");
2506 int start = quick_search(methods, name);
2507 int end = start + 1;
2508 if (start != -1) {
2509 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2510 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2511 *end_ptr = end;
2512 return start;
2513 }
2514 return -1;
2515 }
2516
2517 // uncached_lookup_method searches both the local class methods array and all
2518 // superclasses methods arrays, skipping any overpass methods in superclasses,
2519 // and possibly skipping private methods.
2520 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2521 const Symbol* signature,
2522 OverpassLookupMode overpass_mode,
2523 PrivateLookupMode private_mode) const {
2524 OverpassLookupMode overpass_local_mode = overpass_mode;
2525 const Klass* klass = this;
2526 while (klass != nullptr) {
2527 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
2528 signature,
2529 overpass_local_mode,
2530 StaticLookupMode::find,
2531 private_mode);
2532 if (method != nullptr) {
2533 return method;
2534 }
2535 if (name == vmSymbols::object_initializer_name()) {
2536 break; // <init> is never inherited
2537 }
2538 klass = klass->super();
2539 overpass_local_mode = OverpassLookupMode::skip; // Always ignore overpass methods in superclasses
2540 }
2541 return nullptr;
2542 }
2543
2544 #ifdef ASSERT
2545 // search through class hierarchy and return true if this class or
2546 // one of the superclasses was redefined
2547 bool InstanceKlass::has_redefined_this_or_super() const {
2548 const Klass* klass = this;
2549 while (klass != nullptr) {
2550 if (InstanceKlass::cast(klass)->has_been_redefined()) {
2551 return true;
2552 }
2553 klass = klass->super();
2554 }
2555 return false;
2556 }
2557 #endif
2558
2559 // lookup a method in the default methods list then in all transitive interfaces
2560 // Do NOT return private or static methods
2561 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2562 Symbol* signature) const {
2563 Method* m = nullptr;
2564 if (default_methods() != nullptr) {
2565 m = find_method(default_methods(), name, signature);
2566 }
2567 // Look up interfaces
2568 if (m == nullptr) {
2569 m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2570 }
2571 return m;
2572 }
2573
2574 // lookup a method in all the interfaces that this class implements
2575 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2576 // They should only be found in the initial InterfaceMethodRef
2577 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2578 Symbol* signature,
2579 DefaultsLookupMode defaults_mode) const {
2580 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2581 int num_ifs = all_ifs->length();
2582 InstanceKlass *ik = nullptr;
2583 for (int i = 0; i < num_ifs; i++) {
2584 ik = all_ifs->at(i);
2585 Method* m = ik->lookup_method(name, signature);
2586 if (m != nullptr && m->is_public() && !m->is_static() &&
2587 ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2588 return m;
2589 }
2590 }
2591 return nullptr;
2592 }
2593
2594 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2595 :_st(st), _verbose(verbose) {
2596 ResourceMark rm;
2597 _st->print("%-18s ", "KlassAddr");
2598 _st->print("%-4s ", "Size");
2599 _st->print("%-20s ", "State");
2600 _st->print("%-7s ", "Flags");
2601 _st->print("%-5s ", "ClassName");
2602 _st->cr();
2603 }
2604
2605 void PrintClassClosure::do_klass(Klass* k) {
2606 ResourceMark rm;
2607 // klass pointer
2608 _st->print(PTR_FORMAT " ", p2i(k));
2609 // klass size
2610 _st->print("%4d ", k->size());
2611 // initialization state
2612 if (k->is_instance_klass()) {
2613 _st->print("%-20s ",InstanceKlass::cast(k)->init_state_name());
2614 } else {
2615 _st->print("%-20s ","");
2616 }
2617 // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2618 char buf[10];
2619 int i = 0;
2620 if (k->has_finalizer()) buf[i++] = 'F';
2621 if (k->is_instance_klass()) {
2622 InstanceKlass* ik = InstanceKlass::cast(k);
2623 if (ik->has_final_method()) buf[i++] = 'f';
2624 if (ik->is_rewritten()) buf[i++] = 'W';
2625 if (ik->is_contended()) buf[i++] = 'C';
2626 if (ik->has_been_redefined()) buf[i++] = 'R';
2627 if (ik->is_shared()) buf[i++] = 'S';
2628 }
2629 buf[i++] = '\0';
2630 _st->print("%-7s ", buf);
2631 // klass name
2632 _st->print("%-5s ", k->external_name());
2633 // end
2634 _st->cr();
2635 if (_verbose) {
2636 k->print_on(_st);
2637 }
2638 }
2639
2640 /* jni_id_for for jfieldIds only */
2641 JNIid* InstanceKlass::jni_id_for(int offset) {
2642 MutexLocker ml(JfieldIdCreation_lock);
2643 JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2644 if (probe == nullptr) {
2645 // Allocate new static field identifier
2646 probe = new JNIid(this, offset, jni_ids());
2647 set_jni_ids(probe);
2648 }
2649 return probe;
2650 }
2651
2652 u2 InstanceKlass::enclosing_method_data(int offset) const {
2653 const Array<jushort>* const inner_class_list = inner_classes();
2654 if (inner_class_list == nullptr) {
2655 return 0;
2656 }
2657 const int length = inner_class_list->length();
2658 if (length % inner_class_next_offset == 0) {
2659 return 0;
2660 }
2661 const int index = length - enclosing_method_attribute_size;
2662 assert(offset < enclosing_method_attribute_size, "invalid offset");
2663 return inner_class_list->at(index + offset);
2664 }
2665
2666 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2667 u2 method_index) {
2668 Array<jushort>* inner_class_list = inner_classes();
2669 assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2670 int length = inner_class_list->length();
2671 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2672 int index = length - enclosing_method_attribute_size;
2673 inner_class_list->at_put(
2674 index + enclosing_method_class_index_offset, class_index);
2675 inner_class_list->at_put(
2676 index + enclosing_method_method_index_offset, method_index);
2677 }
2678 }
2679
2680 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2681 if (method->is_old() && !method->is_obsolete()) {
2682 // If the method passed in is old (but not obsolete), use the current version.
2683 method = method_with_idnum((int)idnum);
2684 assert(method != nullptr, "old and but not obsolete, so should exist");
2685 }
2686 jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2687 Atomic::release_store(&jmeths[idnum + 1], new_id);
2688 return new_id;
2689 }
2690
2691 // Lookup or create a jmethodID.
2692 // This code is called by the VMThread and JavaThreads so the
2693 // locking has to be done very carefully to avoid deadlocks
2694 // and/or other cache consistency problems.
2695 //
2696 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2697 Method* method = method_h();
2698 int idnum = method->method_idnum();
2699 jmethodID* jmeths = methods_jmethod_ids_acquire();
2700
2701 // We use a double-check locking idiom here because this cache is
2702 // performance sensitive. In the normal system, this cache only
2703 // transitions from null to non-null which is safe because we use
2704 // release_set_methods_jmethod_ids() to advertise the new cache.
2705 // A partially constructed cache should never be seen by a racing
2706 // thread. We also use release_store() to save a new jmethodID
2707 // in the cache so a partially constructed jmethodID should never be
2708 // seen either. Cache reads of existing jmethodIDs proceed without a
2709 // lock, but cache writes of a new jmethodID requires uniqueness and
2710 // creation of the cache itself requires no leaks so a lock is
2711 // acquired in those two cases.
2712 //
2713 // If the RedefineClasses() API has been used, then this cache grows
2714 // in the redefinition safepoint.
2715
2716 if (jmeths == nullptr) {
2717 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2718 jmeths = methods_jmethod_ids_acquire();
2719 // Still null?
2720 if (jmeths == nullptr) {
2721 size_t size = idnum_allocated_count();
2722 assert(size > (size_t)idnum, "should already have space");
2723 jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2724 memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2725 // cache size is stored in element[0], other elements offset by one
2726 jmeths[0] = (jmethodID)size;
2727 jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2728
2729 // publish jmeths
2730 release_set_methods_jmethod_ids(jmeths);
2731 return new_id;
2732 }
2733 }
2734
2735 jmethodID id = Atomic::load_acquire(&jmeths[idnum + 1]);
2736 if (id == nullptr) {
2737 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2738 id = jmeths[idnum + 1];
2739 // Still null?
2740 if (id == nullptr) {
2741 return update_jmethod_id(jmeths, method, idnum);
2742 }
2743 }
2744 return id;
2745 }
2746
2747 void InstanceKlass::update_methods_jmethod_cache() {
2748 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2749 jmethodID* cache = _methods_jmethod_ids;
2750 if (cache != nullptr) {
2751 size_t size = idnum_allocated_count();
2752 size_t old_size = (size_t)cache[0];
2753 if (old_size < size + 1) {
2754 // Allocate a larger one and copy entries to the new one.
2755 // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2756 jmethodID* new_cache = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2757 memset(new_cache, 0, (size + 1) * sizeof(jmethodID));
2758 // The cache size is stored in element[0]; the other elements are offset by one.
2759 new_cache[0] = (jmethodID)size;
2760
2761 for (int i = 1; i <= (int)old_size; i++) {
2762 new_cache[i] = cache[i];
2763 }
2764 _methods_jmethod_ids = new_cache;
2765 FREE_C_HEAP_ARRAY(jmethodID, cache);
2766 }
2767 }
2768 }
2769
2770 // Figure out how many jmethodIDs haven't been allocated, and make
2771 // sure space for them is pre-allocated. This makes getting all
2772 // method ids much, much faster with classes with more than 8
2773 // methods, and has a *substantial* effect on performance with jvmti
2774 // code that loads all jmethodIDs for all classes.
2775 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2776 int new_jmeths = 0;
2777 int length = methods()->length();
2778 for (int index = start_offset; index < length; index++) {
2779 Method* m = methods()->at(index);
2780 jmethodID id = m->find_jmethod_id_or_null();
2781 if (id == nullptr) {
2782 new_jmeths++;
2783 }
2784 }
2785 if (new_jmeths != 0) {
2786 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2787 }
2788 }
2789
2790 // Lookup a jmethodID, null if not found. Do no blocking, no allocations, no handles
2791 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2792 int idnum = method->method_idnum();
2793 jmethodID* jmeths = methods_jmethod_ids_acquire();
2794 return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2795 }
2796
2797 inline DependencyContext InstanceKlass::dependencies() {
2798 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2799 return dep_context;
2800 }
2801
2802 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2803 dependencies().mark_dependent_nmethods(deopt_scope, changes);
2804 }
2805
2806 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2807 assert_lock_strong(CodeCache_lock);
2808 dependencies().add_dependent_nmethod(nm);
2809 }
2810
2811 void InstanceKlass::clean_dependency_context() {
2812 dependencies().clean_unloading_dependents();
2813 }
2814
2815 #ifndef PRODUCT
2816 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2817 dependencies().print_dependent_nmethods(verbose);
2818 }
2819
2820 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2821 return dependencies().is_dependent_nmethod(nm);
2822 }
2823 #endif //PRODUCT
2824
2825 void InstanceKlass::clean_weak_instanceklass_links() {
2826 clean_implementors_list();
2827 clean_method_data();
2828 }
2829
2830 void InstanceKlass::clean_implementors_list() {
2831 assert(is_loader_alive(), "this klass should be live");
2832 if (is_interface()) {
2833 assert (ClassUnloading, "only called for ClassUnloading");
2834 for (;;) {
2835 // Use load_acquire due to competing with inserts
2836 InstanceKlass* volatile* iklass = adr_implementor();
2837 assert(iklass != nullptr, "Klass must not be null");
2838 InstanceKlass* impl = Atomic::load_acquire(iklass);
2839 if (impl != nullptr && !impl->is_loader_alive()) {
2840 // null this field, might be an unloaded instance klass or null
2841 if (Atomic::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2842 // Successfully unlinking implementor.
2843 if (log_is_enabled(Trace, class, unload)) {
2844 ResourceMark rm;
2845 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2846 }
2847 return;
2848 }
2849 } else {
2850 return;
2851 }
2852 }
2853 }
2854 }
2855
2856 void InstanceKlass::clean_method_data() {
2857 for (int m = 0; m < methods()->length(); m++) {
2858 MethodData* mdo = methods()->at(m)->method_data();
2859 if (mdo != nullptr) {
2860 mdo->clean_method_data(/*always_clean*/false);
2861 }
2862 }
2863 }
2864
2865 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2866 Klass::metaspace_pointers_do(it);
2867
2868 if (log_is_enabled(Trace, aot)) {
2869 ResourceMark rm;
2870 log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2871 }
2872
2873 it->push(&_annotations);
2874 it->push((Klass**)&_array_klasses);
2875 if (!is_rewritten()) {
2876 it->push(&_constants, MetaspaceClosure::_writable);
2877 } else {
2878 it->push(&_constants);
2879 }
2880 it->push(&_inner_classes);
2881 #if INCLUDE_JVMTI
2882 it->push(&_previous_versions);
2883 #endif
2884 #if INCLUDE_CDS
2885 // For "old" classes with methods containing the jsr bytecode, the _methods array will
2886 // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2887 // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2888 // The length check on the _methods is necessary because classes which don't have any
2889 // methods share the Universe::_the_empty_method_array which is in the RO region.
2890 if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2891 // To handle jsr bytecode, new Method* maybe stored into _methods
2892 it->push(&_methods, MetaspaceClosure::_writable);
2893 } else {
2894 #endif
2895 it->push(&_methods);
2896 #if INCLUDE_CDS
2897 }
2898 #endif
2899 it->push(&_default_methods);
2900 it->push(&_local_interfaces);
2901 it->push(&_transitive_interfaces);
2902 it->push(&_method_ordering);
2903 if (!is_rewritten()) {
2904 it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2905 } else {
2906 it->push(&_default_vtable_indices);
2907 }
2908
2909 it->push(&_fieldinfo_stream);
2910 // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2911 it->push(&_fields_status, MetaspaceClosure::_writable);
2912
2913 if (itable_length() > 0) {
2914 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2915 int method_table_offset_in_words = ioe->offset()/wordSize;
2916 int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2917
2918 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2919 / itableOffsetEntry::size();
2920
2921 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2922 if (ioe->interface_klass() != nullptr) {
2923 it->push(ioe->interface_klass_addr());
2924 itableMethodEntry* ime = ioe->first_method_entry(this);
2925 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2926 for (int index = 0; index < n; index ++) {
2927 it->push(ime[index].method_addr());
2928 }
2929 }
2930 }
2931 }
2932
2933 it->push(&_nest_host);
2934 it->push(&_nest_members);
2935 it->push(&_permitted_subclasses);
2936 it->push(&_loadable_descriptors);
2937 it->push(&_record_components);
2938 it->push(&_inline_layout_info_array, MetaspaceClosure::_writable);
2939 }
2940
2941 #if INCLUDE_CDS
2942 void InstanceKlass::remove_unshareable_info() {
2943
2944 if (is_linked()) {
2945 assert(can_be_verified_at_dumptime(), "must be");
2946 // Remember this so we can avoid walking the hierarchy at runtime.
2947 set_verified_at_dump_time();
2948 }
2949
2950 Klass::remove_unshareable_info();
2951
2952 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2953 // Classes are attempted to link during dumping and may fail,
2954 // but these classes are still in the dictionary and class list in CLD.
2955 // If the class has failed verification, there is nothing else to remove.
2956 return;
2957 }
2958
2959 // Reset to the 'allocated' state to prevent any premature accessing to
2960 // a shared class at runtime while the class is still being loaded and
2961 // restored. A class' init_state is set to 'loaded' at runtime when it's
2962 // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2963 _init_state = allocated;
2964
2965 { // Otherwise this needs to take out the Compile_lock.
2966 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2967 init_implementor();
2968 }
2969
2970 // Call remove_unshareable_info() on other objects that belong to this class, except
2971 // for constants()->remove_unshareable_info(), which is called in a separate pass in
2972 // ArchiveBuilder::make_klasses_shareable(),
2973
2974 for (int i = 0; i < methods()->length(); i++) {
2975 Method* m = methods()->at(i);
2976 m->remove_unshareable_info();
2977 }
2978
2979 // do array classes also.
2980 if (array_klasses() != nullptr) {
2981 array_klasses()->remove_unshareable_info();
2982 }
2983
2984 // These are not allocated from metaspace. They are safe to set to nullptr.
2985 _source_debug_extension = nullptr;
2986 _dep_context = nullptr;
2987 _osr_nmethods_head = nullptr;
2988 #if INCLUDE_JVMTI
2989 _breakpoints = nullptr;
2990 _previous_versions = nullptr;
2991 _cached_class_file = nullptr;
2992 _jvmti_cached_class_field_map = nullptr;
2993 #endif
2994
2995 _init_thread = nullptr;
2996 _methods_jmethod_ids = nullptr;
2997 _jni_ids = nullptr;
2998 _oop_map_cache = nullptr;
2999 if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
3000 // keep _nest_host
3001 } else {
3002 // clear _nest_host to ensure re-load at runtime
3003 _nest_host = nullptr;
3004 }
3005 init_shared_package_entry();
3006 _dep_context_last_cleaned = 0;
3007 DEBUG_ONLY(_shared_class_load_count = 0);
3008
3009 remove_unshareable_flags();
3010 }
3011
3012 void InstanceKlass::remove_unshareable_flags() {
3013 // clear all the flags/stats that shouldn't be in the archived version
3014 assert(!is_scratch_class(), "must be");
3015 assert(!has_been_redefined(), "must be");
3016 #if INCLUDE_JVMTI
3017 set_is_being_redefined(false);
3018 #endif
3019 set_has_resolved_methods(false);
3020 }
3021
3022 void InstanceKlass::remove_java_mirror() {
3023 Klass::remove_java_mirror();
3024
3025 // do array classes also.
3026 if (array_klasses() != nullptr) {
3027 array_klasses()->remove_java_mirror();
3028 }
3029 }
3030
3031 void InstanceKlass::init_shared_package_entry() {
3032 assert(CDSConfig::is_dumping_archive(), "must be");
3033 #if !INCLUDE_CDS_JAVA_HEAP
3034 _package_entry = nullptr;
3035 #else
3036 if (CDSConfig::is_dumping_full_module_graph()) {
3037 if (defined_by_other_loaders()) {
3038 _package_entry = nullptr;
3039 } else {
3040 _package_entry = PackageEntry::get_archived_entry(_package_entry);
3041 }
3042 } else if (CDSConfig::is_dumping_dynamic_archive() &&
3043 CDSConfig::is_using_full_module_graph() &&
3044 MetaspaceShared::is_in_shared_metaspace(_package_entry)) {
3045 // _package_entry is an archived package in the base archive. Leave it as is.
3046 } else {
3047 _package_entry = nullptr;
3048 }
3049 ArchivePtrMarker::mark_pointer((address**)&_package_entry);
3050 #endif
3051 }
3052
3053 void InstanceKlass::compute_has_loops_flag_for_methods() {
3054 Array<Method*>* methods = this->methods();
3055 for (int index = 0; index < methods->length(); ++index) {
3056 Method* m = methods->at(index);
3057 if (!m->is_overpass()) { // work around JDK-8305771
3058 m->compute_has_loops_flag();
3059 }
3060 }
3061 }
3062
3063 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
3064 PackageEntry* pkg_entry, TRAPS) {
3065 // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
3066 // before the InstanceKlass is added to the SystemDictionary. Make
3067 // sure the current state is <loaded.
3068 assert(!is_loaded(), "invalid init state");
3069 assert(!shared_loading_failed(), "Must not try to load failed class again");
3070 set_package(loader_data, pkg_entry, CHECK);
3071 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
3072
3073 if (is_inline_klass()) {
3074 InlineKlass::cast(this)->initialize_calling_convention(CHECK);
3075 }
3076
3077 Array<Method*>* methods = this->methods();
3078 int num_methods = methods->length();
3079 for (int index = 0; index < num_methods; ++index) {
3080 methods->at(index)->restore_unshareable_info(CHECK);
3081 }
3082 #if INCLUDE_JVMTI
3083 if (JvmtiExport::has_redefined_a_class()) {
3084 // Reinitialize vtable because RedefineClasses may have changed some
3085 // entries in this vtable for super classes so the CDS vtable might
3086 // point to old or obsolete entries. RedefineClasses doesn't fix up
3087 // vtables in the shared system dictionary, only the main one.
3088 // It also redefines the itable too so fix that too.
3089 // First fix any default methods that point to a super class that may
3090 // have been redefined.
3091 bool trace_name_printed = false;
3092 adjust_default_methods(&trace_name_printed);
3093 if (verified_at_dump_time()) {
3094 // Initialize vtable and itable for classes which can be verified at dump time.
3095 // Unlinked classes such as old classes with major version < 50 cannot be verified
3096 // at dump time.
3097 vtable().initialize_vtable();
3098 itable().initialize_itable();
3099 }
3100 }
3101 #endif // INCLUDE_JVMTI
3102
3103 // restore constant pool resolved references
3104 constants()->restore_unshareable_info(CHECK);
3105
3106 if (array_klasses() != nullptr) {
3107 // To get a consistent list of classes we need MultiArray_lock to ensure
3108 // array classes aren't observed while they are being restored.
3109 RecursiveLocker rl(MultiArray_lock, THREAD);
3110 assert(this == ObjArrayKlass::cast(array_klasses())->bottom_klass(), "sanity");
3111 // Array classes have null protection domain.
3112 // --> see ArrayKlass::complete_create_array_klass()
3113 array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
3114 }
3115
3116 // Initialize @ValueBased class annotation if not already set in the archived klass.
3117 if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
3118 set_is_value_based();
3119 }
3120 }
3121
3122 // Check if a class or any of its supertypes has a version older than 50.
3123 // CDS will not perform verification of old classes during dump time because
3124 // without changing the old verifier, the verification constraint cannot be
3125 // retrieved during dump time.
3126 // Verification of archived old classes will be performed during run time.
3127 bool InstanceKlass::can_be_verified_at_dumptime() const {
3128 if (MetaspaceShared::is_in_shared_metaspace(this)) {
3129 // This is a class that was dumped into the base archive, so we know
3130 // it was verified at dump time.
3131 return true;
3132 }
3133 if (major_version() < 50 /*JAVA_6_VERSION*/) {
3134 return false;
3135 }
3136 if (java_super() != nullptr && !java_super()->can_be_verified_at_dumptime()) {
3137 return false;
3138 }
3139 Array<InstanceKlass*>* interfaces = local_interfaces();
3140 int len = interfaces->length();
3141 for (int i = 0; i < len; i++) {
3142 if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
3143 return false;
3144 }
3145 }
3146 return true;
3147 }
3148
3149 #endif // INCLUDE_CDS
3150
3151 #if INCLUDE_JVMTI
3152 static void clear_all_breakpoints(Method* m) {
3153 m->clear_all_breakpoints();
3154 }
3155 #endif
3156
3157 void InstanceKlass::unload_class(InstanceKlass* ik) {
3158
3159 if (ik->is_scratch_class()) {
3160 assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
3161 return;
3162 }
3163 assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
3164
3165 // Release dependencies.
3166 ik->dependencies().remove_all_dependents();
3167
3168 // notify the debugger
3169 if (JvmtiExport::should_post_class_unload()) {
3170 JvmtiExport::post_class_unload(ik);
3171 }
3172
3173 // notify ClassLoadingService of class unload
3174 ClassLoadingService::notify_class_unloaded(ik);
3175
3176 SystemDictionaryShared::handle_class_unloading(ik);
3177
3178 if (log_is_enabled(Info, class, unload)) {
3179 ResourceMark rm;
3180 log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
3181 }
3182
3183 Events::log_class_unloading(Thread::current(), ik);
3184
3185 #if INCLUDE_JFR
3186 assert(ik != nullptr, "invariant");
3187 EventClassUnload event;
3188 event.set_unloadedClass(ik);
3189 event.set_definingClassLoader(ik->class_loader_data());
3190 event.commit();
3191 #endif
3192 }
3193
3194 static void method_release_C_heap_structures(Method* m) {
3195 m->release_C_heap_structures();
3196 }
3197
3198 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
3199 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
3200 // Clean up C heap
3201 Klass::release_C_heap_structures();
3202
3203 // Deallocate and call destructors for MDO mutexes
3204 if (release_sub_metadata) {
3205 methods_do(method_release_C_heap_structures);
3206 }
3207
3208 // Deallocate oop map cache
3209 if (_oop_map_cache != nullptr) {
3210 delete _oop_map_cache;
3211 _oop_map_cache = nullptr;
3212 }
3213
3214 // Deallocate JNI identifiers for jfieldIDs
3215 JNIid::deallocate(jni_ids());
3216 set_jni_ids(nullptr);
3217
3218 jmethodID* jmeths = methods_jmethod_ids_acquire();
3219 if (jmeths != nullptr) {
3220 release_set_methods_jmethod_ids(nullptr);
3221 FreeHeap(jmeths);
3222 }
3223
3224 assert(_dep_context == nullptr,
3225 "dependencies should already be cleaned");
3226
3227 #if INCLUDE_JVMTI
3228 // Deallocate breakpoint records
3229 if (breakpoints() != nullptr) {
3230 methods_do(clear_all_breakpoints);
3231 assert(breakpoints() == nullptr, "should have cleared breakpoints");
3232 }
3233
3234 // deallocate the cached class file
3235 if (_cached_class_file != nullptr) {
3236 os::free(_cached_class_file);
3237 _cached_class_file = nullptr;
3238 }
3239 #endif
3240
3241 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
3242
3243 if (release_sub_metadata) {
3244 constants()->release_C_heap_structures();
3245 }
3246 }
3247
3248 // The constant pool is on stack if any of the methods are executing or
3249 // referenced by handles.
3250 bool InstanceKlass::on_stack() const {
3251 return _constants->on_stack();
3252 }
3253
3254 Symbol* InstanceKlass::source_file_name() const { return _constants->source_file_name(); }
3255 u2 InstanceKlass::source_file_name_index() const { return _constants->source_file_name_index(); }
3256 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3257
3258 // minor and major version numbers of class file
3259 u2 InstanceKlass::minor_version() const { return _constants->minor_version(); }
3260 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3261 u2 InstanceKlass::major_version() const { return _constants->major_version(); }
3262 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3263
3264 InstanceKlass* InstanceKlass::get_klass_version(int version) {
3265 for (InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3266 if (ik->constants()->version() == version) {
3267 return ik;
3268 }
3269 }
3270 return nullptr;
3271 }
3272
3273 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3274 if (array == nullptr) {
3275 _source_debug_extension = nullptr;
3276 } else {
3277 // Adding one to the attribute length in order to store a null terminator
3278 // character could cause an overflow because the attribute length is
3279 // already coded with an u4 in the classfile, but in practice, it's
3280 // unlikely to happen.
3281 assert((length+1) > length, "Overflow checking");
3282 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3283 for (int i = 0; i < length; i++) {
3284 sde[i] = array[i];
3285 }
3286 sde[length] = '\0';
3287 _source_debug_extension = sde;
3288 }
3289 }
3290
3291 Symbol* InstanceKlass::generic_signature() const { return _constants->generic_signature(); }
3292 u2 InstanceKlass::generic_signature_index() const { return _constants->generic_signature_index(); }
3293 void InstanceKlass::set_generic_signature_index(u2 sig_index) { _constants->set_generic_signature_index(sig_index); }
3294
3295 const char* InstanceKlass::signature_name() const {
3296 return signature_name_of_carrier(JVM_SIGNATURE_CLASS);
3297 }
3298
3299 const char* InstanceKlass::signature_name_of_carrier(char c) const {
3300 // Get the internal name as a c string
3301 const char* src = (const char*) (name()->as_C_string());
3302 const int src_length = (int)strlen(src);
3303
3304 char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3305
3306 // Add L or Q as type indicator
3307 int dest_index = 0;
3308 dest[dest_index++] = c;
3309
3310 // Add the actual class name
3311 for (int src_index = 0; src_index < src_length; ) {
3312 dest[dest_index++] = src[src_index++];
3313 }
3314
3315 if (is_hidden()) { // Replace the last '+' with a '.'.
3316 for (int index = (int)src_length; index > 0; index--) {
3317 if (dest[index] == '+') {
3318 dest[index] = JVM_SIGNATURE_DOT;
3319 break;
3320 }
3321 }
3322 }
3323
3324 // Add the semicolon and the null
3325 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3326 dest[dest_index] = '\0';
3327 return dest;
3328 }
3329
3330 ModuleEntry* InstanceKlass::module() const {
3331 if (is_hidden() &&
3332 in_unnamed_package() &&
3333 class_loader_data()->has_class_mirror_holder()) {
3334 // For a non-strong hidden class defined to an unnamed package,
3335 // its (class held) CLD will not have an unnamed module created for it.
3336 // Two choices to find the correct ModuleEntry:
3337 // 1. If hidden class is within a nest, use nest host's module
3338 // 2. Find the unnamed module off from the class loader
3339 // For now option #2 is used since a nest host is not set until
3340 // after the instance class is created in jvm_lookup_define_class().
3341 if (class_loader_data()->is_boot_class_loader_data()) {
3342 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3343 } else {
3344 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3345 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3346 return java_lang_Module::module_entry(module);
3347 }
3348 }
3349
3350 // Class is in a named package
3351 if (!in_unnamed_package()) {
3352 return _package_entry->module();
3353 }
3354
3355 // Class is in an unnamed package, return its loader's unnamed module
3356 return class_loader_data()->unnamed_module();
3357 }
3358
3359 bool InstanceKlass::in_javabase_module() const {
3360 return module()->name() == vmSymbols::java_base();
3361 }
3362
3363 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3364
3365 // ensure java/ packages only loaded by boot or platform builtin loaders
3366 // not needed for shared class since CDS does not archive prohibited classes.
3367 if (!is_shared()) {
3368 check_prohibited_package(name(), loader_data, CHECK);
3369 }
3370
3371 if (is_shared() && _package_entry != nullptr) {
3372 if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3373 // we can use the saved package
3374 assert(MetaspaceShared::is_in_shared_metaspace(_package_entry), "must be");
3375 return;
3376 } else {
3377 _package_entry = nullptr;
3378 }
3379 }
3380
3381 // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3382 // it returns, so we need to decrement it when the current function exits.
3383 TempNewSymbol from_class_name =
3384 (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3385
3386 Symbol* pkg_name;
3387 if (pkg_entry != nullptr) {
3388 pkg_name = pkg_entry->name();
3389 } else {
3390 pkg_name = from_class_name;
3391 }
3392
3393 if (pkg_name != nullptr && loader_data != nullptr) {
3394
3395 // Find in class loader's package entry table.
3396 _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3397
3398 // If the package name is not found in the loader's package
3399 // entry table, it is an indication that the package has not
3400 // been defined. Consider it defined within the unnamed module.
3401 if (_package_entry == nullptr) {
3402
3403 if (!ModuleEntryTable::javabase_defined()) {
3404 // Before java.base is defined during bootstrapping, define all packages in
3405 // the java.base module. If a non-java.base package is erroneously placed
3406 // in the java.base module it will be caught later when java.base
3407 // is defined by ModuleEntryTable::verify_javabase_packages check.
3408 assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3409 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3410 } else {
3411 assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3412 _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3413 }
3414
3415 // A package should have been successfully created
3416 DEBUG_ONLY(ResourceMark rm(THREAD));
3417 assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3418 name()->as_C_string(), loader_data->loader_name_and_id());
3419 }
3420
3421 if (log_is_enabled(Debug, module)) {
3422 ResourceMark rm(THREAD);
3423 ModuleEntry* m = _package_entry->module();
3424 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3425 external_name(),
3426 pkg_name->as_C_string(),
3427 loader_data->loader_name_and_id(),
3428 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3429 }
3430 } else {
3431 ResourceMark rm(THREAD);
3432 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3433 external_name(),
3434 (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3435 UNNAMED_MODULE);
3436 }
3437 }
3438
3439 // Function set_classpath_index ensures that for a non-null _package_entry
3440 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3441 // It then sets the classpath_index in the package entry record.
3442 //
3443 // The classpath_index field is used to find the entry on the boot loader class
3444 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3445 // in an unnamed module. It is also used to indicate (for all packages whose
3446 // classes are loaded by the boot loader) that at least one of the package's
3447 // classes has been loaded.
3448 void InstanceKlass::set_classpath_index(s2 path_index) {
3449 if (_package_entry != nullptr) {
3450 DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3451 assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3452 assert(path_index != -1, "Unexpected classpath_index");
3453 _package_entry->set_classpath_index(path_index);
3454 }
3455 }
3456
3457 // different versions of is_same_class_package
3458
3459 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3460 oop classloader1 = this->class_loader();
3461 PackageEntry* classpkg1 = this->package();
3462 if (class2->is_objArray_klass()) {
3463 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3464 }
3465
3466 oop classloader2;
3467 PackageEntry* classpkg2;
3468 if (class2->is_instance_klass()) {
3469 classloader2 = class2->class_loader();
3470 classpkg2 = class2->package();
3471 } else {
3472 assert(class2->is_typeArray_klass(), "should be type array");
3473 classloader2 = nullptr;
3474 classpkg2 = nullptr;
3475 }
3476
3477 // Same package is determined by comparing class loader
3478 // and package entries. Both must be the same. This rule
3479 // applies even to classes that are defined in the unnamed
3480 // package, they still must have the same class loader.
3481 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3482 return true;
3483 }
3484
3485 return false;
3486 }
3487
3488 // return true if this class and other_class are in the same package. Classloader
3489 // and classname information is enough to determine a class's package
3490 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3491 const Symbol* other_class_name) const {
3492 if (class_loader() != other_class_loader) {
3493 return false;
3494 }
3495 if (name()->fast_compare(other_class_name) == 0) {
3496 return true;
3497 }
3498
3499 {
3500 ResourceMark rm;
3501
3502 bool bad_class_name = false;
3503 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3504 if (bad_class_name) {
3505 return false;
3506 }
3507 // Check that package_from_class_name() returns null, not "", if there is no package.
3508 assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3509
3510 const Symbol* const this_package_name =
3511 this->package() != nullptr ? this->package()->name() : nullptr;
3512
3513 if (this_package_name == nullptr || other_pkg == nullptr) {
3514 // One of the two doesn't have a package. Only return true if the other
3515 // one also doesn't have a package.
3516 return this_package_name == other_pkg;
3517 }
3518
3519 // Check if package is identical
3520 return this_package_name->fast_compare(other_pkg) == 0;
3521 }
3522 }
3523
3524 static bool is_prohibited_package_slow(Symbol* class_name) {
3525 // Caller has ResourceMark
3526 int length;
3527 jchar* unicode = class_name->as_unicode(length);
3528 return (length >= 5 &&
3529 unicode[0] == 'j' &&
3530 unicode[1] == 'a' &&
3531 unicode[2] == 'v' &&
3532 unicode[3] == 'a' &&
3533 unicode[4] == '/');
3534 }
3535
3536 // Only boot and platform class loaders can define classes in "java/" packages.
3537 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3538 ClassLoaderData* loader_data,
3539 TRAPS) {
3540 if (!loader_data->is_boot_class_loader_data() &&
3541 !loader_data->is_platform_class_loader_data() &&
3542 class_name != nullptr && class_name->utf8_length() >= 5) {
3543 ResourceMark rm(THREAD);
3544 bool prohibited;
3545 const u1* base = class_name->base();
3546 if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3547 prohibited = is_prohibited_package_slow(class_name);
3548 } else {
3549 char* name = class_name->as_C_string();
3550 prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3551 }
3552 if (prohibited) {
3553 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3554 assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3555 char* name = pkg_name->as_C_string();
3556 const char* class_loader_name = loader_data->loader_name_and_id();
3557 StringUtils::replace_no_expand(name, "/", ".");
3558 const char* msg_text1 = "Class loader (instance of): ";
3559 const char* msg_text2 = " tried to load prohibited package name: ";
3560 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3561 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3562 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3563 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3564 }
3565 }
3566 return;
3567 }
3568
3569 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3570 constantPoolHandle i_cp(THREAD, constants());
3571 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3572 int ioff = iter.inner_class_info_index();
3573 if (ioff != 0) {
3574 // Check to see if the name matches the class we're looking for
3575 // before attempting to find the class.
3576 if (i_cp->klass_name_at_matches(this, ioff)) {
3577 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3578 if (this == inner_klass) {
3579 *ooff = iter.outer_class_info_index();
3580 *noff = iter.inner_name_index();
3581 return true;
3582 }
3583 }
3584 }
3585 }
3586 return false;
3587 }
3588
3589 void InstanceKlass::check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS) {
3590 assert(type->is_instance_klass(), "Sanity check");
3591 if (type->is_identity_class()) {
3592 ResourceMark rm(THREAD);
3593 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3594 err_msg("Class %s expects class %s to be a value class, but it is an identity class",
3595 container_klass_name->as_C_string(),
3596 type->external_name()));
3597 }
3598
3599 if (type->is_abstract()) {
3600 ResourceMark rm(THREAD);
3601 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
3602 err_msg("Class %s expects class %s to be concrete value type, but it is an abstract class",
3603 container_klass_name->as_C_string(),
3604 type->external_name()));
3605 }
3606 }
3607
3608 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3609 InstanceKlass* outer_klass = nullptr;
3610 *inner_is_member = false;
3611 int ooff = 0, noff = 0;
3612 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3613 if (has_inner_classes_attr) {
3614 constantPoolHandle i_cp(THREAD, constants());
3615 if (ooff != 0) {
3616 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3617 if (!ok->is_instance_klass()) {
3618 // If the outer class is not an instance klass then it cannot have
3619 // declared any inner classes.
3620 ResourceMark rm(THREAD);
3621 // Names are all known to be < 64k so we know this formatted message is not excessively large.
3622 Exceptions::fthrow(
3623 THREAD_AND_LOCATION,
3624 vmSymbols::java_lang_IncompatibleClassChangeError(),
3625 "%s and %s disagree on InnerClasses attribute",
3626 ok->external_name(),
3627 external_name());
3628 return nullptr;
3629 }
3630 outer_klass = InstanceKlass::cast(ok);
3631 *inner_is_member = true;
3632 }
3633 if (nullptr == outer_klass) {
3634 // It may be a local class; try for that.
3635 int encl_method_class_idx = enclosing_method_class_index();
3636 if (encl_method_class_idx != 0) {
3637 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3638 outer_klass = InstanceKlass::cast(ok);
3639 *inner_is_member = false;
3640 }
3641 }
3642 }
3643
3644 // If no inner class attribute found for this class.
3645 if (nullptr == outer_klass) return nullptr;
3646
3647 // Throws an exception if outer klass has not declared k as an inner klass
3648 // We need evidence that each klass knows about the other, or else
3649 // the system could allow a spoof of an inner class to gain access rights.
3650 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3651 return outer_klass;
3652 }
3653
3654 u2 InstanceKlass::compute_modifier_flags() const {
3655 u2 access = access_flags().as_unsigned_short();
3656
3657 // But check if it happens to be member class.
3658 InnerClassesIterator iter(this);
3659 for (; !iter.done(); iter.next()) {
3660 int ioff = iter.inner_class_info_index();
3661 // Inner class attribute can be zero, skip it.
3662 // Strange but true: JVM spec. allows null inner class refs.
3663 if (ioff == 0) continue;
3664
3665 // only look at classes that are already loaded
3666 // since we are looking for the flags for our self.
3667 Symbol* inner_name = constants()->klass_name_at(ioff);
3668 if (name() == inner_name) {
3669 // This is really a member class.
3670 access = iter.inner_access_flags();
3671 break;
3672 }
3673 }
3674 return access;
3675 }
3676
3677 jint InstanceKlass::jvmti_class_status() const {
3678 jint result = 0;
3679
3680 if (is_linked()) {
3681 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3682 }
3683
3684 if (is_initialized()) {
3685 assert(is_linked(), "Class status is not consistent");
3686 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3687 }
3688 if (is_in_error_state()) {
3689 result |= JVMTI_CLASS_STATUS_ERROR;
3690 }
3691 return result;
3692 }
3693
3694 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3695 bool implements_interface; // initialized by method_at_itable_or_null
3696 Method* m = method_at_itable_or_null(holder, index,
3697 implements_interface); // out parameter
3698 if (m != nullptr) {
3699 assert(implements_interface, "sanity");
3700 return m;
3701 } else if (implements_interface) {
3702 // Throw AbstractMethodError since corresponding itable slot is empty.
3703 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3704 } else {
3705 // If the interface isn't implemented by the receiver class,
3706 // the VM should throw IncompatibleClassChangeError.
3707 ResourceMark rm(THREAD);
3708 stringStream ss;
3709 bool same_module = (module() == holder->module());
3710 ss.print("Receiver class %s does not implement "
3711 "the interface %s defining the method to be called "
3712 "(%s%s%s)",
3713 external_name(), holder->external_name(),
3714 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3715 (same_module) ? "" : "; ",
3716 (same_module) ? "" : holder->class_in_module_of_loader());
3717 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3718 }
3719 }
3720
3721 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3722 klassItable itable(this);
3723 for (int i = 0; i < itable.size_offset_table(); i++) {
3724 itableOffsetEntry* offset_entry = itable.offset_entry(i);
3725 if (offset_entry->interface_klass() == holder) {
3726 implements_interface = true;
3727 itableMethodEntry* ime = offset_entry->first_method_entry(this);
3728 Method* m = ime[index].method();
3729 return m;
3730 }
3731 }
3732 implements_interface = false;
3733 return nullptr; // offset entry not found
3734 }
3735
3736 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3737 assert(is_linked(), "required");
3738 assert(intf_method->method_holder()->is_interface(), "not an interface method");
3739 assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3740
3741 int vtable_index = Method::invalid_vtable_index;
3742 Symbol* name = intf_method->name();
3743 Symbol* signature = intf_method->signature();
3744
3745 // First check in default method array
3746 if (!intf_method->is_abstract() && default_methods() != nullptr) {
3747 int index = find_method_index(default_methods(),
3748 name, signature,
3749 Klass::OverpassLookupMode::find,
3750 Klass::StaticLookupMode::find,
3751 Klass::PrivateLookupMode::find);
3752 if (index >= 0) {
3753 vtable_index = default_vtable_indices()->at(index);
3754 }
3755 }
3756 if (vtable_index == Method::invalid_vtable_index) {
3757 // get vtable_index for miranda methods
3758 klassVtable vt = vtable();
3759 vtable_index = vt.index_of_miranda(name, signature);
3760 }
3761 return vtable_index;
3762 }
3763
3764 #if INCLUDE_JVMTI
3765 // update default_methods for redefineclasses for methods that are
3766 // not yet in the vtable due to concurrent subclass define and superinterface
3767 // redefinition
3768 // Note: those in the vtable, should have been updated via adjust_method_entries
3769 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3770 // search the default_methods for uses of either obsolete or EMCP methods
3771 if (default_methods() != nullptr) {
3772 for (int index = 0; index < default_methods()->length(); index ++) {
3773 Method* old_method = default_methods()->at(index);
3774 if (old_method == nullptr || !old_method->is_old()) {
3775 continue; // skip uninteresting entries
3776 }
3777 assert(!old_method->is_deleted(), "default methods may not be deleted");
3778 Method* new_method = old_method->get_new_method();
3779 default_methods()->at_put(index, new_method);
3780
3781 if (log_is_enabled(Info, redefine, class, update)) {
3782 ResourceMark rm;
3783 if (!(*trace_name_printed)) {
3784 log_info(redefine, class, update)
3785 ("adjust: klassname=%s default methods from name=%s",
3786 external_name(), old_method->method_holder()->external_name());
3787 *trace_name_printed = true;
3788 }
3789 log_debug(redefine, class, update, vtables)
3790 ("default method update: %s(%s) ",
3791 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3792 }
3793 }
3794 }
3795 }
3796 #endif // INCLUDE_JVMTI
3797
3798 // On-stack replacement stuff
3799 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3800 assert_lock_strong(NMethodState_lock);
3801 #ifndef PRODUCT
3802 nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3803 assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3804 "redundant OSR recompilation detected. memory leak in CodeCache!");
3805 #endif
3806 // only one compilation can be active
3807 assert(n->is_osr_method(), "wrong kind of nmethod");
3808 n->set_osr_link(osr_nmethods_head());
3809 set_osr_nmethods_head(n);
3810 // Raise the highest osr level if necessary
3811 n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3812
3813 // Get rid of the osr methods for the same bci that have lower levels.
3814 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3815 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3816 if (inv != nullptr && inv->is_in_use()) {
3817 inv->make_not_entrant("OSR invalidation of lower levels");
3818 }
3819 }
3820 }
3821
3822 // Remove osr nmethod from the list. Return true if found and removed.
3823 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3824 // This is a short non-blocking critical region, so the no safepoint check is ok.
3825 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3826 assert(n->is_osr_method(), "wrong kind of nmethod");
3827 nmethod* last = nullptr;
3828 nmethod* cur = osr_nmethods_head();
3829 int max_level = CompLevel_none; // Find the max comp level excluding n
3830 Method* m = n->method();
3831 // Search for match
3832 bool found = false;
3833 while(cur != nullptr && cur != n) {
3834 if (m == cur->method()) {
3835 // Find max level before n
3836 max_level = MAX2(max_level, cur->comp_level());
3837 }
3838 last = cur;
3839 cur = cur->osr_link();
3840 }
3841 nmethod* next = nullptr;
3842 if (cur == n) {
3843 found = true;
3844 next = cur->osr_link();
3845 if (last == nullptr) {
3846 // Remove first element
3847 set_osr_nmethods_head(next);
3848 } else {
3849 last->set_osr_link(next);
3850 }
3851 }
3852 n->set_osr_link(nullptr);
3853 cur = next;
3854 while (cur != nullptr) {
3855 // Find max level after n
3856 if (m == cur->method()) {
3857 max_level = MAX2(max_level, cur->comp_level());
3858 }
3859 cur = cur->osr_link();
3860 }
3861 m->set_highest_osr_comp_level(max_level);
3862 return found;
3863 }
3864
3865 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3866 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3867 nmethod* osr = osr_nmethods_head();
3868 int found = 0;
3869 while (osr != nullptr) {
3870 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3871 if (osr->method() == m) {
3872 deopt_scope->mark(osr);
3873 found++;
3874 }
3875 osr = osr->osr_link();
3876 }
3877 return found;
3878 }
3879
3880 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3881 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3882 nmethod* osr = osr_nmethods_head();
3883 nmethod* best = nullptr;
3884 while (osr != nullptr) {
3885 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3886 // There can be a time when a c1 osr method exists but we are waiting
3887 // for a c2 version. When c2 completes its osr nmethod we will trash
3888 // the c1 version and only be able to find the c2 version. However
3889 // while we overflow in the c1 code at back branches we don't want to
3890 // try and switch to the same code as we are already running
3891
3892 if (osr->method() == m &&
3893 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3894 if (match_level) {
3895 if (osr->comp_level() == comp_level) {
3896 // Found a match - return it.
3897 return osr;
3898 }
3899 } else {
3900 if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3901 if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3902 // Found the best possible - return it.
3903 return osr;
3904 }
3905 best = osr;
3906 }
3907 }
3908 }
3909 osr = osr->osr_link();
3910 }
3911
3912 assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3913 if (best != nullptr && best->comp_level() >= comp_level) {
3914 return best;
3915 }
3916 return nullptr;
3917 }
3918
3919 // -----------------------------------------------------------------------------------------------------
3920 // Printing
3921
3922 #define BULLET " - "
3923
3924 static const char* state_names[] = {
3925 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3926 };
3927
3928 static void print_vtable(address self, intptr_t* start, int len, outputStream* st) {
3929 ResourceMark rm;
3930 int* forward_refs = NEW_RESOURCE_ARRAY(int, len);
3931 for (int i = 0; i < len; i++) forward_refs[i] = 0;
3932 for (int i = 0; i < len; i++) {
3933 intptr_t e = start[i];
3934 st->print("%d : " INTPTR_FORMAT, i, e);
3935 if (forward_refs[i] != 0) {
3936 int from = forward_refs[i];
3937 int off = (int) start[from];
3938 st->print(" (offset %d <= [%d])", off, from);
3939 }
3940 if (MetaspaceObj::is_valid((Metadata*)e)) {
3941 st->print(" ");
3942 ((Metadata*)e)->print_value_on(st);
3943 } else if (self != nullptr && e > 0 && e < 0x10000) {
3944 address location = self + e;
3945 int index = (int)((intptr_t*)location - start);
3946 st->print(" (offset %d => [%d])", (int)e, index);
3947 if (index >= 0 && index < len)
3948 forward_refs[index] = i;
3949 }
3950 st->cr();
3951 }
3952 }
3953
3954 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3955 return print_vtable(nullptr, reinterpret_cast<intptr_t*>(start), len, st);
3956 }
3957
3958 template<typename T>
3959 static void print_array_on(outputStream* st, Array<T>* array) {
3960 if (array == nullptr) { st->print_cr("nullptr"); return; }
3961 array->print_value_on(st); st->cr();
3962 if (Verbose || WizardMode) {
3963 for (int i = 0; i < array->length(); i++) {
3964 st->print("%d : ", i); array->at(i)->print_value_on(st); st->cr();
3965 }
3966 }
3967 }
3968
3969 static void print_array_on(outputStream* st, Array<int>* array) {
3970 if (array == nullptr) { st->print_cr("nullptr"); return; }
3971 array->print_value_on(st); st->cr();
3972 if (Verbose || WizardMode) {
3973 for (int i = 0; i < array->length(); i++) {
3974 st->print("%d : %d", i, array->at(i)); st->cr();
3975 }
3976 }
3977 }
3978
3979 const char* InstanceKlass::init_state_name() const {
3980 return state_names[init_state()];
3981 }
3982
3983 void InstanceKlass::print_on(outputStream* st) const {
3984 assert(is_klass(), "must be klass");
3985 Klass::print_on(st);
3986
3987 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3988 st->print(BULLET"klass size: %d", size()); st->cr();
3989 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3990 st->print(BULLET"flags: "); _misc_flags.print_on(st); st->cr();
3991 st->print(BULLET"state: "); st->print_cr("%s", init_state_name());
3992 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3993 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3994 st->print(BULLET"sub: ");
3995 Klass* sub = subklass();
3996 int n;
3997 for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3998 if (n < MaxSubklassPrintSize) {
3999 sub->print_value_on(st);
4000 st->print(" ");
4001 }
4002 }
4003 if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
4004 st->cr();
4005
4006 if (is_interface()) {
4007 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
4008 if (nof_implementors() == 1) {
4009 st->print_cr(BULLET"implementor: ");
4010 st->print(" ");
4011 implementor()->print_value_on(st);
4012 st->cr();
4013 }
4014 }
4015
4016 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
4017 st->print(BULLET"methods: "); print_array_on(st, methods());
4018 st->print(BULLET"method ordering: "); print_array_on(st, method_ordering());
4019 if (default_methods() != nullptr) {
4020 st->print(BULLET"default_methods: "); print_array_on(st, default_methods());
4021 }
4022 print_on_maybe_null(st, BULLET"default vtable indices: ", default_vtable_indices());
4023 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
4024 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
4025
4026 st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
4027
4028 st->print(BULLET"hash_slot: %d", hash_slot()); st->cr();
4029 st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
4030
4031 if (secondary_supers() != nullptr) {
4032 if (Verbose) {
4033 bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
4034 st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
4035 for (int i = 0; i < _secondary_supers->length(); i++) {
4036 ResourceMark rm; // for external_name()
4037 Klass* secondary_super = _secondary_supers->at(i);
4038 st->print(BULLET"%2d:", i);
4039 if (is_hashed) {
4040 int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
4041 int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
4042 st->print(" dist:%02d:", distance);
4043 }
4044 st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
4045 }
4046 }
4047 }
4048 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
4049
4050 print_on_maybe_null(st, BULLET"class loader data: ", class_loader_data());
4051 print_on_maybe_null(st, BULLET"source file: ", source_file_name());
4052 if (source_debug_extension() != nullptr) {
4053 st->print(BULLET"source debug extension: ");
4054 st->print("%s", source_debug_extension());
4055 st->cr();
4056 }
4057 print_on_maybe_null(st, BULLET"class annotations: ", class_annotations());
4058 print_on_maybe_null(st, BULLET"class type annotations: ", class_type_annotations());
4059 print_on_maybe_null(st, BULLET"field annotations: ", fields_annotations());
4060 print_on_maybe_null(st, BULLET"field type annotations: ", fields_type_annotations());
4061 {
4062 bool have_pv = false;
4063 // previous versions are linked together through the InstanceKlass
4064 for (InstanceKlass* pv_node = previous_versions();
4065 pv_node != nullptr;
4066 pv_node = pv_node->previous_versions()) {
4067 if (!have_pv)
4068 st->print(BULLET"previous version: ");
4069 have_pv = true;
4070 pv_node->constants()->print_value_on(st);
4071 }
4072 if (have_pv) st->cr();
4073 }
4074
4075 print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
4076 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
4077 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
4078 print_on_maybe_null(st, BULLET"record components: ", record_components());
4079 st->print(BULLET"permitted subclasses: "); permitted_subclasses()->print_value_on(st); st->cr();
4080 st->print(BULLET"loadable descriptors: "); loadable_descriptors()->print_value_on(st); st->cr();
4081 if (java_mirror() != nullptr) {
4082 st->print(BULLET"java mirror: ");
4083 java_mirror()->print_value_on(st);
4084 st->cr();
4085 } else {
4086 st->print_cr(BULLET"java mirror: null");
4087 }
4088 st->print(BULLET"vtable length %d (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
4089 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
4090 st->print(BULLET"itable length %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
4091 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(nullptr, start_of_itable(), itable_length(), st);
4092 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
4093
4094 FieldPrinter print_static_field(st);
4095 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
4096 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
4097 FieldPrinter print_nonstatic_field(st);
4098 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
4099 ik->print_nonstatic_fields(&print_nonstatic_field);
4100
4101 st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
4102 OopMapBlock* map = start_of_nonstatic_oop_maps();
4103 OopMapBlock* end_map = map + nonstatic_oop_map_count();
4104 while (map < end_map) {
4105 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
4106 map++;
4107 }
4108 st->cr();
4109 }
4110
4111 void InstanceKlass::print_value_on(outputStream* st) const {
4112 assert(is_klass(), "must be klass");
4113 if (Verbose || WizardMode) access_flags().print_on(st);
4114 name()->print_value_on(st);
4115 }
4116
4117 void FieldPrinter::do_field(fieldDescriptor* fd) {
4118 for (int i = 0; i < _indent; i++) _st->print(" ");
4119 _st->print(BULLET);
4120 if (_obj == nullptr) {
4121 fd->print_on(_st, _base_offset);
4122 _st->cr();
4123 } else {
4124 fd->print_on_for(_st, _obj, _indent, _base_offset);
4125 if (!fd->field_flags().is_flat()) _st->cr();
4126 }
4127 }
4128
4129
4130 void InstanceKlass::oop_print_on(oop obj, outputStream* st, int indent, int base_offset) {
4131 Klass::oop_print_on(obj, st);
4132
4133 if (this == vmClasses::String_klass()) {
4134 typeArrayOop value = java_lang_String::value(obj);
4135 juint length = java_lang_String::length(obj);
4136 if (value != nullptr &&
4137 value->is_typeArray() &&
4138 length <= (juint) value->length()) {
4139 st->print(BULLET"string: ");
4140 java_lang_String::print(obj, st);
4141 st->cr();
4142 }
4143 }
4144
4145 st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
4146 FieldPrinter print_field(st, obj, indent, base_offset);
4147 print_nonstatic_fields(&print_field);
4148
4149 if (this == vmClasses::Class_klass()) {
4150 st->print(BULLET"signature: ");
4151 java_lang_Class::print_signature(obj, st);
4152 st->cr();
4153 Klass* real_klass = java_lang_Class::as_Klass(obj);
4154 if (real_klass != nullptr && real_klass->is_instance_klass()) {
4155 st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
4156 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
4157 }
4158 } else if (this == vmClasses::MethodType_klass()) {
4159 st->print(BULLET"signature: ");
4160 java_lang_invoke_MethodType::print_signature(obj, st);
4161 st->cr();
4162 }
4163 }
4164
4165 #ifndef PRODUCT
4166
4167 bool InstanceKlass::verify_itable_index(int i) {
4168 int method_count = klassItable::method_count_for_interface(this);
4169 assert(i >= 0 && i < method_count, "index out of bounds");
4170 return true;
4171 }
4172
4173 #endif //PRODUCT
4174
4175 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
4176 st->print("a ");
4177 name()->print_value_on(st);
4178 obj->print_address_on(st);
4179 if (this == vmClasses::String_klass()
4180 && java_lang_String::value(obj) != nullptr) {
4181 ResourceMark rm;
4182 int len = java_lang_String::length(obj);
4183 int plen = (len < 24 ? len : 12);
4184 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
4185 st->print(" = \"%s\"", str);
4186 if (len > plen)
4187 st->print("...[%d]", len);
4188 } else if (this == vmClasses::Class_klass()) {
4189 Klass* k = java_lang_Class::as_Klass(obj);
4190 st->print(" = ");
4191 if (k != nullptr) {
4192 k->print_value_on(st);
4193 } else {
4194 const char* tname = type2name(java_lang_Class::primitive_type(obj));
4195 st->print("%s", tname ? tname : "type?");
4196 }
4197 } else if (this == vmClasses::MethodType_klass()) {
4198 st->print(" = ");
4199 java_lang_invoke_MethodType::print_signature(obj, st);
4200 } else if (java_lang_boxing_object::is_instance(obj)) {
4201 st->print(" = ");
4202 java_lang_boxing_object::print(obj, st);
4203 } else if (this == vmClasses::LambdaForm_klass()) {
4204 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
4205 if (vmentry != nullptr) {
4206 st->print(" => ");
4207 vmentry->print_value_on(st);
4208 }
4209 } else if (this == vmClasses::MemberName_klass()) {
4210 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
4211 if (vmtarget != nullptr) {
4212 st->print(" = ");
4213 vmtarget->print_value_on(st);
4214 } else {
4215 oop clazz = java_lang_invoke_MemberName::clazz(obj);
4216 oop name = java_lang_invoke_MemberName::name(obj);
4217 if (clazz != nullptr) {
4218 clazz->print_value_on(st);
4219 } else {
4220 st->print("null");
4221 }
4222 st->print(".");
4223 if (name != nullptr) {
4224 name->print_value_on(st);
4225 } else {
4226 st->print("null");
4227 }
4228 }
4229 }
4230 }
4231
4232 const char* InstanceKlass::internal_name() const {
4233 return external_name();
4234 }
4235
4236 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
4237 const ModuleEntry* module_entry,
4238 const ClassFileStream* cfs) const {
4239
4240 if (ClassListWriter::is_enabled()) {
4241 ClassListWriter::write(this, cfs);
4242 }
4243
4244 print_class_load_helper(loader_data, module_entry, cfs);
4245 print_class_load_cause_logging();
4246 }
4247
4248 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
4249 const ModuleEntry* module_entry,
4250 const ClassFileStream* cfs) const {
4251
4252 if (!log_is_enabled(Info, class, load)) {
4253 return;
4254 }
4255
4256 ResourceMark rm;
4257 LogMessage(class, load) msg;
4258 stringStream info_stream;
4259
4260 // Name and class hierarchy info
4261 info_stream.print("%s", external_name());
4262
4263 // Source
4264 if (cfs != nullptr) {
4265 if (cfs->source() != nullptr) {
4266 const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
4267 if (module_name != nullptr) {
4268 // When the boot loader created the stream, it didn't know the module name
4269 // yet. Let's format it now.
4270 if (cfs->from_boot_loader_modules_image()) {
4271 info_stream.print(" source: jrt:/%s", module_name);
4272 } else {
4273 info_stream.print(" source: %s", cfs->source());
4274 }
4275 } else {
4276 info_stream.print(" source: %s", cfs->source());
4277 }
4278 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
4279 Thread* current = Thread::current();
4280 Klass* caller = current->is_Java_thread() ?
4281 JavaThread::cast(current)->security_get_caller_class(1):
4282 nullptr;
4283 // caller can be null, for example, during a JVMTI VM_Init hook
4284 if (caller != nullptr) {
4285 info_stream.print(" source: instance of %s", caller->external_name());
4286 } else {
4287 // source is unknown
4288 }
4289 } else {
4290 oop class_loader = loader_data->class_loader();
4291 info_stream.print(" source: %s", class_loader->klass()->external_name());
4292 }
4293 } else {
4294 assert(this->is_shared(), "must be");
4295 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
4296 info_stream.print(" source: shared objects file (top)");
4297 } else {
4298 info_stream.print(" source: shared objects file");
4299 }
4300 }
4301
4302 msg.info("%s", info_stream.as_string());
4303
4304 if (log_is_enabled(Debug, class, load)) {
4305 stringStream debug_stream;
4306
4307 // Class hierarchy info
4308 debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4309 p2i(this), p2i(superklass()));
4310
4311 // Interfaces
4312 if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4313 debug_stream.print(" interfaces:");
4314 int length = local_interfaces()->length();
4315 for (int i = 0; i < length; i++) {
4316 debug_stream.print(" " PTR_FORMAT,
4317 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
4318 }
4319 }
4320
4321 // Class loader
4322 debug_stream.print(" loader: [");
4323 loader_data->print_value_on(&debug_stream);
4324 debug_stream.print("]");
4325
4326 // Classfile checksum
4327 if (cfs) {
4328 debug_stream.print(" bytes: %d checksum: %08x",
4329 cfs->length(),
4330 ClassLoader::crc32(0, (const char*)cfs->buffer(),
4331 cfs->length()));
4332 }
4333
4334 msg.debug("%s", debug_stream.as_string());
4335 }
4336 }
4337
4338 void InstanceKlass::print_class_load_cause_logging() const {
4339 bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4340 if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4341 JavaThread* current = JavaThread::current();
4342 ResourceMark rm(current);
4343 const char* name = external_name();
4344
4345 if (LogClassLoadingCauseFor == nullptr ||
4346 (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4347 strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4348 return;
4349 }
4350
4351 // Log Java stack first
4352 {
4353 LogMessage(class, load, cause) msg;
4354 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4355
4356 info_stream.print_cr("Java stack when loading %s:", name);
4357 current->print_stack_on(&info_stream);
4358 }
4359
4360 // Log native stack second
4361 if (log_cause_native) {
4362 // Log to string first so that lines can be indented
4363 stringStream stack_stream;
4364 char buf[O_BUFLEN];
4365 address lastpc = nullptr;
4366 NativeStackPrinter nsp(current);
4367 nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4368 true /* print_source_info */, -1 /* max stack */);
4369
4370 LogMessage(class, load, cause, native) msg;
4371 NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4372 info_stream.print_cr("Native stack when loading %s:", name);
4373
4374 // Print each native stack line to the log
4375 int size = (int) stack_stream.size();
4376 char* stack = stack_stream.as_string();
4377 char* stack_end = stack + size;
4378 char* line_start = stack;
4379 for (char* p = stack; p < stack_end; p++) {
4380 if (*p == '\n') {
4381 *p = '\0';
4382 info_stream.print_cr("\t%s", line_start);
4383 line_start = p + 1;
4384 }
4385 }
4386 if (line_start < stack_end) {
4387 info_stream.print_cr("\t%s", line_start);
4388 }
4389 }
4390 }
4391 }
4392
4393 // Verification
4394
4395 class VerifyFieldClosure: public BasicOopIterateClosure {
4396 protected:
4397 template <class T> void do_oop_work(T* p) {
4398 oop obj = RawAccess<>::oop_load(p);
4399 if (!oopDesc::is_oop_or_null(obj)) {
4400 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4401 Universe::print_on(tty);
4402 guarantee(false, "boom");
4403 }
4404 }
4405 public:
4406 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
4407 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4408 };
4409
4410 void InstanceKlass::verify_on(outputStream* st) {
4411 #ifndef PRODUCT
4412 // Avoid redundant verifies, this really should be in product.
4413 if (_verify_count == Universe::verify_count()) return;
4414 _verify_count = Universe::verify_count();
4415 #endif
4416
4417 // Verify Klass
4418 Klass::verify_on(st);
4419
4420 // Verify that klass is present in ClassLoaderData
4421 guarantee(class_loader_data()->contains_klass(this),
4422 "this class isn't found in class loader data");
4423
4424 // Verify vtables
4425 if (is_linked()) {
4426 // $$$ This used to be done only for m/s collections. Doing it
4427 // always seemed a valid generalization. (DLD -- 6/00)
4428 vtable().verify(st);
4429 }
4430
4431 // Verify first subklass
4432 if (subklass() != nullptr) {
4433 guarantee(subklass()->is_klass(), "should be klass");
4434 }
4435
4436 // Verify siblings
4437 Klass* super = this->super();
4438 Klass* sib = next_sibling();
4439 if (sib != nullptr) {
4440 if (sib == this) {
4441 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4442 }
4443
4444 guarantee(sib->is_klass(), "should be klass");
4445 guarantee(sib->super() == super, "siblings should have same superklass");
4446 }
4447
4448 // Verify local interfaces
4449 if (local_interfaces()) {
4450 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4451 for (int j = 0; j < local_interfaces->length(); j++) {
4452 InstanceKlass* e = local_interfaces->at(j);
4453 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4454 }
4455 }
4456
4457 // Verify transitive interfaces
4458 if (transitive_interfaces() != nullptr) {
4459 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4460 for (int j = 0; j < transitive_interfaces->length(); j++) {
4461 InstanceKlass* e = transitive_interfaces->at(j);
4462 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4463 }
4464 }
4465
4466 // Verify methods
4467 if (methods() != nullptr) {
4468 Array<Method*>* methods = this->methods();
4469 for (int j = 0; j < methods->length(); j++) {
4470 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4471 }
4472 for (int j = 0; j < methods->length() - 1; j++) {
4473 Method* m1 = methods->at(j);
4474 Method* m2 = methods->at(j + 1);
4475 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4476 }
4477 }
4478
4479 // Verify method ordering
4480 if (method_ordering() != nullptr) {
4481 Array<int>* method_ordering = this->method_ordering();
4482 int length = method_ordering->length();
4483 if (JvmtiExport::can_maintain_original_method_order() ||
4484 ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4485 guarantee(length == methods()->length(), "invalid method ordering length");
4486 jlong sum = 0;
4487 for (int j = 0; j < length; j++) {
4488 int original_index = method_ordering->at(j);
4489 guarantee(original_index >= 0, "invalid method ordering index");
4490 guarantee(original_index < length, "invalid method ordering index");
4491 sum += original_index;
4492 }
4493 // Verify sum of indices 0,1,...,length-1
4494 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4495 } else {
4496 guarantee(length == 0, "invalid method ordering length");
4497 }
4498 }
4499
4500 // Verify default methods
4501 if (default_methods() != nullptr) {
4502 Array<Method*>* methods = this->default_methods();
4503 for (int j = 0; j < methods->length(); j++) {
4504 guarantee(methods->at(j)->is_method(), "non-method in methods array");
4505 }
4506 for (int j = 0; j < methods->length() - 1; j++) {
4507 Method* m1 = methods->at(j);
4508 Method* m2 = methods->at(j + 1);
4509 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4510 }
4511 }
4512
4513 // Verify JNI static field identifiers
4514 if (jni_ids() != nullptr) {
4515 jni_ids()->verify(this);
4516 }
4517
4518 // Verify other fields
4519 if (constants() != nullptr) {
4520 guarantee(constants()->is_constantPool(), "should be constant pool");
4521 }
4522 }
4523
4524 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4525 Klass::oop_verify_on(obj, st);
4526 VerifyFieldClosure blk;
4527 obj->oop_iterate(&blk);
4528 }
4529
4530
4531 // JNIid class for jfieldIDs only
4532 // Note to reviewers:
4533 // These JNI functions are just moved over to column 1 and not changed
4534 // in the compressed oops workspace.
4535 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
4536 _holder = holder;
4537 _offset = offset;
4538 _next = next;
4539 DEBUG_ONLY(_is_static_field_id = false;)
4540 }
4541
4542
4543 JNIid* JNIid::find(int offset) {
4544 JNIid* current = this;
4545 while (current != nullptr) {
4546 if (current->offset() == offset) return current;
4547 current = current->next();
4548 }
4549 return nullptr;
4550 }
4551
4552 void JNIid::deallocate(JNIid* current) {
4553 while (current != nullptr) {
4554 JNIid* next = current->next();
4555 delete current;
4556 current = next;
4557 }
4558 }
4559
4560
4561 void JNIid::verify(Klass* holder) {
4562 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
4563 int end_field_offset;
4564 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
4565
4566 JNIid* current = this;
4567 while (current != nullptr) {
4568 guarantee(current->holder() == holder, "Invalid klass in JNIid");
4569 #ifdef ASSERT
4570 int o = current->offset();
4571 if (current->is_static_field_id()) {
4572 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
4573 }
4574 #endif
4575 current = current->next();
4576 }
4577 }
4578
4579 void InstanceKlass::set_init_state(ClassState state) {
4580 #ifdef ASSERT
4581 bool good_state = is_shared() ? (_init_state <= state)
4582 : (_init_state < state);
4583 assert(good_state || state == allocated, "illegal state transition");
4584 #endif
4585 assert(_init_thread == nullptr, "should be cleared before state change");
4586 Atomic::release_store(&_init_state, state);
4587 }
4588
4589 #if INCLUDE_JVMTI
4590
4591 // RedefineClasses() support for previous versions
4592
4593 // Globally, there is at least one previous version of a class to walk
4594 // during class unloading, which is saved because old methods in the class
4595 // are still running. Otherwise the previous version list is cleaned up.
4596 bool InstanceKlass::_should_clean_previous_versions = false;
4597
4598 // Returns true if there are previous versions of a class for class
4599 // unloading only. Also resets the flag to false. purge_previous_version
4600 // will set the flag to true if there are any left, i.e., if there's any
4601 // work to do for next time. This is to avoid the expensive code cache
4602 // walk in CLDG::clean_deallocate_lists().
4603 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4604 bool ret = _should_clean_previous_versions;
4605 log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4606 ret ? "true" : "false");
4607 _should_clean_previous_versions = false;
4608 return ret;
4609 }
4610
4611 // This nulls out jmethodIDs for all methods in 'klass'
4612 // It needs to be called explicitly for all previous versions of a class because these may not be cleaned up
4613 // during class unloading.
4614 // We can not use the jmethodID cache associated with klass directly because the 'previous' versions
4615 // do not have the jmethodID cache filled in. Instead, we need to lookup jmethodID for each method and this
4616 // is expensive - O(n) for one jmethodID lookup. For all contained methods it is O(n^2).
4617 // The reason for expensive jmethodID lookup for each method is that there is no direct link between method and jmethodID.
4618 void InstanceKlass::clear_jmethod_ids(InstanceKlass* klass) {
4619 Array<Method*>* method_refs = klass->methods();
4620 for (int k = 0; k < method_refs->length(); k++) {
4621 Method* method = method_refs->at(k);
4622 if (method != nullptr && method->is_obsolete()) {
4623 method->clear_jmethod_id();
4624 }
4625 }
4626 }
4627
4628 // Purge previous versions before adding new previous versions of the class and
4629 // during class unloading.
4630 void InstanceKlass::purge_previous_version_list() {
4631 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4632 assert(has_been_redefined(), "Should only be called for main class");
4633
4634 // Quick exit.
4635 if (previous_versions() == nullptr) {
4636 return;
4637 }
4638
4639 // This klass has previous versions so see what we can cleanup
4640 // while it is safe to do so.
4641
4642 int deleted_count = 0; // leave debugging breadcrumbs
4643 int live_count = 0;
4644 ClassLoaderData* loader_data = class_loader_data();
4645 assert(loader_data != nullptr, "should never be null");
4646
4647 ResourceMark rm;
4648 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4649
4650 // previous versions are linked together through the InstanceKlass
4651 InstanceKlass* pv_node = previous_versions();
4652 InstanceKlass* last = this;
4653 int version = 0;
4654
4655 // check the previous versions list
4656 for (; pv_node != nullptr; ) {
4657
4658 ConstantPool* pvcp = pv_node->constants();
4659 assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4660
4661 if (!pvcp->on_stack()) {
4662 // If the constant pool isn't on stack, none of the methods
4663 // are executing. Unlink this previous_version.
4664 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4665 // so will be deallocated during the next phase of class unloading.
4666 log_trace(redefine, class, iklass, purge)
4667 ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4668 // Unlink from previous version list.
4669 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4670 InstanceKlass* next = pv_node->previous_versions();
4671 clear_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4672 pv_node->link_previous_versions(nullptr); // point next to null
4673 last->link_previous_versions(next);
4674 // Delete this node directly. Nothing is referring to it and we don't
4675 // want it to increase the counter for metadata to delete in CLDG.
4676 MetadataFactory::free_metadata(loader_data, pv_node);
4677 pv_node = next;
4678 deleted_count++;
4679 version++;
4680 continue;
4681 } else {
4682 assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4683 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4684 live_count++;
4685 if (pvcp->is_shared()) {
4686 // Shared previous versions can never be removed so no cleaning is needed.
4687 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4688 } else {
4689 // Previous version alive, set that clean is needed for next time.
4690 _should_clean_previous_versions = true;
4691 log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4692 }
4693 }
4694
4695 // next previous version
4696 last = pv_node;
4697 pv_node = pv_node->previous_versions();
4698 version++;
4699 }
4700 log_trace(redefine, class, iklass, purge)
4701 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4702 }
4703
4704 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4705 int emcp_method_count) {
4706 int obsolete_method_count = old_methods->length() - emcp_method_count;
4707
4708 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4709 _previous_versions != nullptr) {
4710 // We have a mix of obsolete and EMCP methods so we have to
4711 // clear out any matching EMCP method entries the hard way.
4712 int local_count = 0;
4713 for (int i = 0; i < old_methods->length(); i++) {
4714 Method* old_method = old_methods->at(i);
4715 if (old_method->is_obsolete()) {
4716 // only obsolete methods are interesting
4717 Symbol* m_name = old_method->name();
4718 Symbol* m_signature = old_method->signature();
4719
4720 // previous versions are linked together through the InstanceKlass
4721 int j = 0;
4722 for (InstanceKlass* prev_version = _previous_versions;
4723 prev_version != nullptr;
4724 prev_version = prev_version->previous_versions(), j++) {
4725
4726 Array<Method*>* method_refs = prev_version->methods();
4727 for (int k = 0; k < method_refs->length(); k++) {
4728 Method* method = method_refs->at(k);
4729
4730 if (!method->is_obsolete() &&
4731 method->name() == m_name &&
4732 method->signature() == m_signature) {
4733 // The current RedefineClasses() call has made all EMCP
4734 // versions of this method obsolete so mark it as obsolete
4735 log_trace(redefine, class, iklass, add)
4736 ("%s(%s): flush obsolete method @%d in version @%d",
4737 m_name->as_C_string(), m_signature->as_C_string(), k, j);
4738
4739 method->set_is_obsolete();
4740 break;
4741 }
4742 }
4743
4744 // The previous loop may not find a matching EMCP method, but
4745 // that doesn't mean that we can optimize and not go any
4746 // further back in the PreviousVersion generations. The EMCP
4747 // method for this generation could have already been made obsolete,
4748 // but there still may be an older EMCP method that has not
4749 // been made obsolete.
4750 }
4751
4752 if (++local_count >= obsolete_method_count) {
4753 // no more obsolete methods so bail out now
4754 break;
4755 }
4756 }
4757 }
4758 }
4759 }
4760
4761 // Save the scratch_class as the previous version if any of the methods are running.
4762 // The previous_versions are used to set breakpoints in EMCP methods and they are
4763 // also used to clean MethodData links to redefined methods that are no longer running.
4764 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4765 int emcp_method_count) {
4766 assert(Thread::current()->is_VM_thread(),
4767 "only VMThread can add previous versions");
4768
4769 ResourceMark rm;
4770 log_trace(redefine, class, iklass, add)
4771 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4772
4773 // Clean out old previous versions for this class
4774 purge_previous_version_list();
4775
4776 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
4777 // a previous redefinition may be made obsolete by this redefinition.
4778 Array<Method*>* old_methods = scratch_class->methods();
4779 mark_newly_obsolete_methods(old_methods, emcp_method_count);
4780
4781 // If the constant pool for this previous version of the class
4782 // is not marked as being on the stack, then none of the methods
4783 // in this previous version of the class are on the stack so
4784 // we don't need to add this as a previous version.
4785 ConstantPool* cp_ref = scratch_class->constants();
4786 if (!cp_ref->on_stack()) {
4787 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4788 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4789 return;
4790 }
4791
4792 // Add previous version if any methods are still running or if this is
4793 // a shared class which should never be removed.
4794 assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4795 scratch_class->link_previous_versions(previous_versions());
4796 link_previous_versions(scratch_class);
4797 if (cp_ref->is_shared()) {
4798 log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4799 } else {
4800 // We only set clean_previous_versions flag for processing during class
4801 // unloading for non-shared classes.
4802 _should_clean_previous_versions = true;
4803 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4804 }
4805 } // end add_previous_version()
4806
4807 #endif // INCLUDE_JVMTI
4808
4809 Method* InstanceKlass::method_with_idnum(int idnum) {
4810 Method* m = nullptr;
4811 if (idnum < methods()->length()) {
4812 m = methods()->at(idnum);
4813 }
4814 if (m == nullptr || m->method_idnum() != idnum) {
4815 for (int index = 0; index < methods()->length(); ++index) {
4816 m = methods()->at(index);
4817 if (m->method_idnum() == idnum) {
4818 return m;
4819 }
4820 }
4821 // None found, return null for the caller to handle.
4822 return nullptr;
4823 }
4824 return m;
4825 }
4826
4827
4828 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4829 if (idnum >= methods()->length()) {
4830 return nullptr;
4831 }
4832 Method* m = methods()->at(idnum);
4833 if (m != nullptr && m->orig_method_idnum() == idnum) {
4834 return m;
4835 }
4836 // Obsolete method idnum does not match the original idnum
4837 for (int index = 0; index < methods()->length(); ++index) {
4838 m = methods()->at(index);
4839 if (m->orig_method_idnum() == idnum) {
4840 return m;
4841 }
4842 }
4843 // None found, return null for the caller to handle.
4844 return nullptr;
4845 }
4846
4847
4848 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4849 InstanceKlass* holder = get_klass_version(version);
4850 if (holder == nullptr) {
4851 return nullptr; // The version of klass is gone, no method is found
4852 }
4853 Method* method = holder->method_with_orig_idnum(idnum);
4854 return method;
4855 }
4856
4857 #if INCLUDE_JVMTI
4858 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4859 return _cached_class_file;
4860 }
4861
4862 jint InstanceKlass::get_cached_class_file_len() {
4863 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4864 }
4865
4866 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4867 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4868 }
4869 #endif
4870
4871 // Make a step iterating over the class hierarchy under the root class.
4872 // Skips subclasses if requested.
4873 void ClassHierarchyIterator::next() {
4874 assert(_current != nullptr, "required");
4875 if (_visit_subclasses && _current->subklass() != nullptr) {
4876 _current = _current->subklass();
4877 return; // visit next subclass
4878 }
4879 _visit_subclasses = true; // reset
4880 while (_current->next_sibling() == nullptr && _current != _root) {
4881 _current = _current->superklass(); // backtrack; no more sibling subclasses left
4882 }
4883 if (_current == _root) {
4884 // Iteration is over (back at root after backtracking). Invalidate the iterator.
4885 _current = nullptr;
4886 return;
4887 }
4888 _current = _current->next_sibling();
4889 return; // visit next sibling subclass
4890 }