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