1 /*
2 * Copyright (c) 1997, 2020, 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 "precompiled.hpp"
26 #include "jvm.h"
27 #include "aot/aotLoader.hpp"
28 #include "classfile/classFileParser.hpp"
29 #include "classfile/classFileStream.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/classLoaderData.inline.hpp"
32 #include "classfile/classLoaderDataGraph.inline.hpp"
33 #include "classfile/classLoaderExt.hpp"
34 #include "classfile/dictionary.hpp"
35 #include "classfile/javaClasses.inline.hpp"
36 #include "classfile/klassFactory.hpp"
37 #include "classfile/loaderConstraints.hpp"
38 #include "classfile/packageEntry.hpp"
39 #include "classfile/placeholders.hpp"
40 #include "classfile/protectionDomainCache.hpp"
41 #include "classfile/resolutionErrors.hpp"
42 #include "classfile/stringTable.hpp"
43 #include "classfile/symbolTable.hpp"
44 #include "classfile/systemDictionary.hpp"
45 #include "classfile/vmSymbols.hpp"
46 #include "code/codeCache.hpp"
47 #include "compiler/compileBroker.hpp"
48 #include "gc/shared/gcTraceTime.inline.hpp"
49 #include "gc/shared/oopStorage.inline.hpp"
50 #include "gc/shared/oopStorageSet.hpp"
51 #include "interpreter/bytecodeStream.hpp"
52 #include "interpreter/interpreter.hpp"
53 #include "jfr/jfrEvents.hpp"
54 #include "logging/log.hpp"
55 #include "logging/logStream.hpp"
56 #include "memory/filemap.hpp"
57 #include "memory/heapShared.hpp"
58 #include "memory/metaspaceClosure.hpp"
59 #include "memory/oopFactory.hpp"
60 #include "memory/resourceArea.hpp"
61 #include "memory/universe.hpp"
62 #include "oops/access.inline.hpp"
63 #include "oops/instanceKlass.hpp"
64 #include "oops/instanceRefKlass.hpp"
65 #include "oops/klass.inline.hpp"
66 #include "oops/method.inline.hpp"
67 #include "oops/methodData.hpp"
68 #include "oops/objArrayKlass.hpp"
69 #include "oops/objArrayOop.inline.hpp"
70 #include "oops/oop.inline.hpp"
71 #include "oops/symbol.hpp"
72 #include "oops/typeArrayKlass.hpp"
73 #include "prims/jvmtiExport.hpp"
74 #include "prims/methodHandles.hpp"
75 #include "runtime/arguments.hpp"
76 #include "runtime/biasedLocking.hpp"
77 #include "runtime/handles.inline.hpp"
78 #include "runtime/java.hpp"
79 #include "runtime/javaCalls.hpp"
80 #include "runtime/mutexLocker.hpp"
81 #include "runtime/sharedRuntime.hpp"
82 #include "runtime/signature.hpp"
83 #include "services/classLoadingService.hpp"
84 #include "services/diagnosticCommand.hpp"
85 #include "services/threadService.hpp"
86 #include "utilities/macros.hpp"
87 #if INCLUDE_CDS
88 #include "classfile/systemDictionaryShared.hpp"
89 #endif
90 #if INCLUDE_JFR
91 #include "jfr/jfr.hpp"
92 #endif
93
94 PlaceholderTable* SystemDictionary::_placeholders = NULL;
95 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
96 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
97 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
98 ProtectionDomainCacheTable* SystemDictionary::_pd_cache_table = NULL;
99
100 oop SystemDictionary::_system_loader_lock_obj = NULL;
101
102 InstanceKlass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
103 = { NULL /*, NULL...*/ };
104
105 InstanceKlass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
106
107 oop SystemDictionary::_java_system_loader = NULL;
108 oop SystemDictionary::_java_platform_loader = NULL;
109
110 // Default ProtectionDomainCacheSize value
111
112 const int defaultProtectionDomainCacheSize = 1009;
113
114 // ----------------------------------------------------------------------------
115 // Java-level SystemLoader and PlatformLoader
116
117 oop SystemDictionary::java_system_loader() {
118 return _java_system_loader;
119 }
120
121 oop SystemDictionary::java_platform_loader() {
122 return _java_platform_loader;
123 }
124
125 void SystemDictionary::compute_java_loaders(TRAPS) {
126 JavaValue result(T_OBJECT);
127 InstanceKlass* class_loader_klass = SystemDictionary::ClassLoader_klass();
128 JavaCalls::call_static(&result,
129 class_loader_klass,
130 vmSymbols::getSystemClassLoader_name(),
131 vmSymbols::void_classloader_signature(),
132 CHECK);
133
134 _java_system_loader = (oop)result.get_jobject();
135
136 JavaCalls::call_static(&result,
137 class_loader_klass,
138 vmSymbols::getPlatformClassLoader_name(),
139 vmSymbols::void_classloader_signature(),
140 CHECK);
141
142 _java_platform_loader = (oop)result.get_jobject();
143 }
144
145 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader) {
146 if (class_loader.is_null()) return ClassLoaderData::the_null_class_loader_data();
147 return ClassLoaderDataGraph::find_or_create(class_loader);
148 }
149
150 // ----------------------------------------------------------------------------
151 // Parallel class loading check
152
153 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
154 if (class_loader.is_null()) return true;
155 if (AlwaysLockClassLoader) return false;
156 return java_lang_ClassLoader::parallelCapable(class_loader());
157 }
158 // ----------------------------------------------------------------------------
159 // ParallelDefineClass flag does not apply to bootclass loader
160 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
161 if (class_loader.is_null()) return false;
162 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
163 return true;
164 }
165 return false;
166 }
167
168 // Returns true if the passed class loader is the builtin application class loader
169 // or a custom system class loader. A customer system class loader can be
170 // specified via -Djava.system.class.loader.
171 bool SystemDictionary::is_system_class_loader(oop class_loader) {
172 if (class_loader == NULL) {
173 return false;
174 }
175 return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass() ||
176 class_loader == _java_system_loader);
177 }
178
179 // Returns true if the passed class loader is the platform class loader.
180 bool SystemDictionary::is_platform_class_loader(oop class_loader) {
181 if (class_loader == NULL) {
182 return false;
183 }
184 return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass());
185 }
186
187 // ----------------------------------------------------------------------------
188 // Resolving of classes
189
190 // Forwards to resolve_or_null
191
192 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
193 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
194 if (HAS_PENDING_EXCEPTION || klass == NULL) {
195 // can return a null klass
196 klass = handle_resolution_exception(class_name, throw_error, klass, THREAD);
197 }
198 return klass;
199 }
200
201 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name,
202 bool throw_error,
203 Klass* klass, TRAPS) {
204 if (HAS_PENDING_EXCEPTION) {
205 // If we have a pending exception we forward it to the caller, unless throw_error is true,
206 // in which case we have to check whether the pending exception is a ClassNotFoundException,
207 // and if so convert it to a NoClassDefFoundError
208 // And chain the original ClassNotFoundException
209 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
210 ResourceMark rm(THREAD);
211 assert(klass == NULL, "Should not have result with exception pending");
212 Handle e(THREAD, PENDING_EXCEPTION);
213 CLEAR_PENDING_EXCEPTION;
214 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
215 } else {
216 return NULL;
217 }
218 }
219 // Class not found, throw appropriate error or exception depending on value of throw_error
220 if (klass == NULL) {
221 ResourceMark rm(THREAD);
222 if (throw_error) {
223 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
224 } else {
225 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
226 }
227 }
228 return klass;
229 }
230
231
232 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
233 bool throw_error, TRAPS)
234 {
235 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
236 }
237
238
239 // Forwards to resolve_array_class_or_null or resolve_instance_class_or_null
240
241 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
242 if (Signature::is_array(class_name)) {
243 return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD);
244 } else {
245 return resolve_instance_class_or_null_helper(class_name, class_loader, protection_domain, THREAD);
246 }
247 }
248
249 // name may be in the form of "java/lang/Object" or "Ljava/lang/Object;"
250 InstanceKlass* SystemDictionary::resolve_instance_class_or_null_helper(Symbol* class_name,
251 Handle class_loader,
252 Handle protection_domain,
253 TRAPS) {
254 assert(class_name != NULL && !Signature::is_array(class_name), "must be");
255 if (Signature::has_envelope(class_name)) {
256 ResourceMark rm(THREAD);
257 // Ignore wrapping L and ;.
258 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
259 class_name->utf8_length() - 2);
260 return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD);
261 } else {
262 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD);
263 }
264 }
265
266 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
267 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
268 }
269
270 // Forwards to resolve_instance_class_or_null
271
272 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
273 Handle class_loader,
274 Handle protection_domain,
275 TRAPS) {
276 assert(Signature::is_array(class_name), "must be array");
277 ResourceMark rm(THREAD);
278 SignatureStream ss(class_name, false);
279 int ndims = ss.skip_array_prefix(); // skip all '['s
280 Klass* k = NULL;
281 BasicType t = ss.type();
282 if (ss.has_envelope()) {
283 Symbol* obj_class = ss.as_symbol();
284 k = SystemDictionary::resolve_instance_class_or_null(obj_class,
285 class_loader,
286 protection_domain,
287 CHECK_NULL);
288 if (k != NULL) {
289 k = k->array_klass(ndims, CHECK_NULL);
290 }
291 } else {
292 k = Universe::typeArrayKlassObj(t);
293 k = TypeArrayKlass::cast(k)->array_klass(ndims, CHECK_NULL);
294 }
295 return k;
296 }
297
298
299 // Must be called for any super-class or super-interface resolution
300 // during class definition to allow class circularity checking
301 // super-interface callers:
302 // parse_interfaces - for defineClass & jvmtiRedefineClasses
303 // super-class callers:
304 // ClassFileParser - for defineClass & jvmtiRedefineClasses
305 // load_shared_class - while loading a class from shared archive
306 // resolve_instance_class_or_null:
307 // via: handle_parallel_super_load
308 // when resolving a class that has an existing placeholder with
309 // a saved superclass [i.e. a defineClass is currently in progress]
310 // if another thread is trying to resolve the class, it must do
311 // super-class checks on its own thread to catch class circularity
312 // This last call is critical in class circularity checking for cases
313 // where classloading is delegated to different threads and the
314 // classloader lock is released.
315 // Take the case: Base->Super->Base
316 // 1. If thread T1 tries to do a defineClass of class Base
317 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
318 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
319 // so it tries to load Super
320 // 3. If we load the class internally, or user classloader uses same thread
321 // loadClassFromxxx or defineClass via parseClassFile Super ...
322 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
323 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
324 // 3.4 calls resolve_super_or_fail Base
325 // 3.5 finds T1,Base -> throws class circularity
326 //OR 4. If T2 tries to resolve Super via defineClass Super ...
327 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
328 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
329 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
330 // 4.4 finds T2, Super -> throws class circularity
331 // Must be called, even if superclass is null, since this is
332 // where the placeholder entry is created which claims this
333 // thread is loading this class/classloader.
334 // Be careful when modifying this code: once you have run
335 // placeholders()->find_and_add(PlaceholderTable::LOAD_SUPER),
336 // you need to find_and_remove it before returning.
337 // So be careful to not exit with a CHECK_ macro betweeen these calls.
338 InstanceKlass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
339 Symbol* super_name,
340 Handle class_loader,
341 Handle protection_domain,
342 bool is_superclass,
343 TRAPS) {
344 assert(!Signature::is_array(super_name), "invalid super class name");
345 #if INCLUDE_CDS
346 if (DumpSharedSpaces) {
347 // Special processing for handling UNREGISTERED shared classes.
348 InstanceKlass* k = SystemDictionaryShared::dump_time_resolve_super_or_fail(child_name,
349 super_name, class_loader, protection_domain, is_superclass, CHECK_NULL);
350 if (k) {
351 return k;
352 }
353 }
354 #endif // INCLUDE_CDS
355
356 // Double-check, if child class is already loaded, just return super-class,interface
357 // Don't add a placedholder if already loaded, i.e. already in appropriate class loader
358 // dictionary.
359 // Make sure there's a placeholder for the *child* before resolving.
360 // Used as a claim that this thread is currently loading superclass/classloader
361 // Used here for ClassCircularity checks and also for heap verification
362 // (every InstanceKlass needs to be in its class loader dictionary or have a placeholder).
363 // Must check ClassCircularity before checking if super class is already loaded.
364 //
365 // We might not already have a placeholder if this child_name was
366 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
367 // the name of the class might not be known until the stream is actually
368 // parsed.
369 // Bugs 4643874, 4715493
370
371 ClassLoaderData* loader_data = class_loader_data(class_loader);
372 Dictionary* dictionary = loader_data->dictionary();
373 unsigned int d_hash = dictionary->compute_hash(child_name);
374 unsigned int p_hash = placeholders()->compute_hash(child_name);
375 int p_index = placeholders()->hash_to_index(p_hash);
376 // can't throw error holding a lock
377 bool child_already_loaded = false;
378 bool throw_circularity_error = false;
379 {
380 MutexLocker mu(THREAD, SystemDictionary_lock);
381 InstanceKlass* childk = find_class(d_hash, child_name, dictionary);
382 InstanceKlass* quicksuperk;
383 // to support // loading: if child done loading, just return superclass
384 // if super_name, & class_loader don't match:
385 // if initial define, SD update will give LinkageError
386 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
387 // so we don't throw an exception here.
388 // see: nsk redefclass014 & java.lang.instrument Instrument032
389 if ((childk != NULL ) && (is_superclass) &&
390 ((quicksuperk = childk->java_super()) != NULL) &&
391 ((quicksuperk->name() == super_name) &&
392 (quicksuperk->class_loader() == class_loader()))) {
393 return quicksuperk;
394 } else {
395 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
396 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
397 throw_circularity_error = true;
398 }
399 }
400 if (!throw_circularity_error) {
401 // Be careful not to exit resolve_super
402 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, super_name, THREAD);
403 }
404 }
405 if (throw_circularity_error) {
406 ResourceMark rm(THREAD);
407 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
408 }
409
410 // java.lang.Object should have been found above
411 assert(super_name != NULL, "null super class for resolving");
412 // Resolve the super class or interface, check results on return
413 InstanceKlass* superk =
414 SystemDictionary::resolve_instance_class_or_null_helper(super_name,
415 class_loader,
416 protection_domain,
417 THREAD);
418
419 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
420 // It is no longer necessary to keep the placeholder table alive until update_dictionary
421 // or error. GC used to walk the placeholder table as strong roots.
422 // The instanceKlass is kept alive because the class loader is on the stack,
423 // which keeps the loader_data alive, as well as all instanceKlasses in
424 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
425 {
426 MutexLocker mu(THREAD, SystemDictionary_lock);
427 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
428 SystemDictionary_lock->notify_all();
429 }
430 if (HAS_PENDING_EXCEPTION || superk == NULL) {
431 // can null superk
432 Klass* k = handle_resolution_exception(super_name, true, superk, THREAD);
433 assert(k == NULL || k == superk, "must be");
434 if (k == NULL) {
435 superk = NULL;
436 }
437 }
438
439 return superk;
440 }
441
442 void SystemDictionary::validate_protection_domain(InstanceKlass* klass,
443 Handle class_loader,
444 Handle protection_domain,
445 TRAPS) {
446 // Now we have to call back to java to check if the initating class has access
447 JavaValue result(T_VOID);
448 LogTarget(Debug, protectiondomain) lt;
449 if (lt.is_enabled()) {
450 ResourceMark rm(THREAD);
451 // Print out trace information
452 LogStream ls(lt);
453 ls.print_cr("Checking package access");
454 if (class_loader() != NULL) {
455 ls.print("class loader: ");
456 class_loader()->print_value_on(&ls);
457 } else {
458 ls.print_cr("class loader: NULL");
459 }
460 if (protection_domain() != NULL) {
461 ls.print(" protection domain: ");
462 protection_domain()->print_value_on(&ls);
463 } else {
464 ls.print_cr(" protection domain: NULL");
465 }
466 ls.print(" loading: "); klass->print_value_on(&ls);
467 ls.cr();
468 }
469
470 // This handle and the class_loader handle passed in keeps this class from
471 // being unloaded through several GC points.
472 // The class_loader handle passed in is the initiating loader.
473 Handle mirror(THREAD, klass->java_mirror());
474
475 InstanceKlass* system_loader = SystemDictionary::ClassLoader_klass();
476 JavaCalls::call_special(&result,
477 class_loader,
478 system_loader,
479 vmSymbols::checkPackageAccess_name(),
480 vmSymbols::class_protectiondomain_signature(),
481 mirror,
482 protection_domain,
483 THREAD);
484
485 if (HAS_PENDING_EXCEPTION) {
486 log_debug(protectiondomain)("DENIED !!!!!!!!!!!!!!!!!!!!!");
487 } else {
488 log_debug(protectiondomain)("granted");
489 }
490
491 if (HAS_PENDING_EXCEPTION) return;
492
493 // If no exception has been thrown, we have validated the protection domain
494 // Insert the protection domain of the initiating class into the set.
495 {
496 ClassLoaderData* loader_data = class_loader_data(class_loader);
497 Dictionary* dictionary = loader_data->dictionary();
498
499 Symbol* kn = klass->name();
500 unsigned int d_hash = dictionary->compute_hash(kn);
501
502 MutexLocker mu(THREAD, SystemDictionary_lock);
503 int d_index = dictionary->hash_to_index(d_hash);
504 dictionary->add_protection_domain(d_index, d_hash, klass,
505 protection_domain, THREAD);
506 }
507 }
508
509 // We only get here if this thread finds that another thread
510 // has already claimed the placeholder token for the current operation,
511 // but that other thread either never owned or gave up the
512 // object lock
513 // Waits on SystemDictionary_lock to indicate placeholder table updated
514 // On return, caller must recheck placeholder table state
515 //
516 // We only get here if
517 // 1) custom classLoader, i.e. not bootstrap classloader
518 // 2) custom classLoader has broken the class loader objectLock
519 // so another thread got here in parallel
520 //
521 // lockObject must be held.
522 // Complicated dance due to lock ordering:
523 // Must first release the classloader object lock to
524 // allow initial definer to complete the class definition
525 // and to avoid deadlock
526 // Reclaim classloader lock object with same original recursion count
527 // Must release SystemDictionary_lock after notify, since
528 // class loader lock must be claimed before SystemDictionary_lock
529 // to prevent deadlocks
530 //
531 // The notify allows applications that did an untimed wait() on
532 // the classloader object lock to not hang.
533 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
534 assert_lock_strong(SystemDictionary_lock);
535
536 bool calledholdinglock
537 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
538 assert(calledholdinglock,"must hold lock for notify");
539 assert((lockObject() != _system_loader_lock_obj && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
540 ObjectSynchronizer::notifyall(lockObject, THREAD);
541 intx recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
542 SystemDictionary_lock->wait();
543 SystemDictionary_lock->unlock();
544 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
545 SystemDictionary_lock->lock();
546 }
547
548 // If the class in is in the placeholder table, class loading is in progress
549 // For cases where the application changes threads to load classes, it
550 // is critical to ClassCircularity detection that we try loading
551 // the superclass on the same thread internally, so we do parallel
552 // super class loading here.
553 // This also is critical in cases where the original thread gets stalled
554 // even in non-circularity situations.
555 // Note: must call resolve_super_or_fail even if null super -
556 // to force placeholder entry creation for this class for circularity detection
557 // Caller must check for pending exception
558 // Returns non-null Klass* if other thread has completed load
559 // and we are done,
560 // If return null Klass* and no pending exception, the caller must load the class
561 InstanceKlass* SystemDictionary::handle_parallel_super_load(
562 Symbol* name, Symbol* superclassname, Handle class_loader,
563 Handle protection_domain, Handle lockObject, TRAPS) {
564
565 ClassLoaderData* loader_data = class_loader_data(class_loader);
566 Dictionary* dictionary = loader_data->dictionary();
567 unsigned int d_hash = dictionary->compute_hash(name);
568 unsigned int p_hash = placeholders()->compute_hash(name);
569 int p_index = placeholders()->hash_to_index(p_hash);
570
571 // superk is not used, resolve_super called for circularity check only
572 // This code is reached in two situations. One if this thread
573 // is loading the same class twice (e.g. ClassCircularity, or
574 // java.lang.instrument).
575 // The second is if another thread started the resolve_super first
576 // and has not yet finished.
577 // In both cases the original caller will clean up the placeholder
578 // entry on error.
579 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
580 superclassname,
581 class_loader,
582 protection_domain,
583 true,
584 CHECK_NULL);
585
586 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
587 // Serial class loaders and bootstrap classloader do wait for superclass loads
588 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
589 MutexLocker mu(THREAD, SystemDictionary_lock);
590 // Check if classloading completed while we were loading superclass or waiting
591 return find_class(d_hash, name, dictionary);
592 }
593
594 // must loop to both handle other placeholder updates
595 // and spurious notifications
596 bool super_load_in_progress = true;
597 PlaceholderEntry* placeholder;
598 while (super_load_in_progress) {
599 MutexLocker mu(THREAD, SystemDictionary_lock);
600 // Check if classloading completed while we were loading superclass or waiting
601 InstanceKlass* check = find_class(d_hash, name, dictionary);
602 if (check != NULL) {
603 // Klass is already loaded, so just return it
604 return check;
605 } else {
606 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
607 if (placeholder && placeholder->super_load_in_progress() ){
608 // We only get here if the application has released the
609 // classloader lock when another thread was in the middle of loading a
610 // superclass/superinterface for this class, and now
611 // this thread is also trying to load this class.
612 // To minimize surprises, the first thread that started to
613 // load a class should be the one to complete the loading
614 // with the classfile it initially expected.
615 // This logic has the current thread wait once it has done
616 // all the superclass/superinterface loading it can, until
617 // the original thread completes the class loading or fails
618 // If it completes we will use the resulting InstanceKlass
619 // which we will find below in the systemDictionary.
620 // We also get here for parallel bootstrap classloader
621 if (class_loader.is_null()) {
622 SystemDictionary_lock->wait();
623 } else {
624 double_lock_wait(lockObject, THREAD);
625 }
626 } else {
627 // If not in SD and not in PH, other thread's load must have failed
628 super_load_in_progress = false;
629 }
630 }
631 }
632 return NULL;
633 }
634
635 static void post_class_load_event(EventClassLoad* event, const InstanceKlass* k, const ClassLoaderData* init_cld) {
636 assert(event != NULL, "invariant");
637 assert(k != NULL, "invariant");
638 assert(event->should_commit(), "invariant");
639 event->set_loadedClass(k);
640 event->set_definingClassLoader(k->class_loader_data());
641 event->set_initiatingClassLoader(init_cld);
642 event->commit();
643 }
644
645
646 // Be careful when modifying this code: once you have run
647 // placeholders()->find_and_add(PlaceholderTable::LOAD_INSTANCE),
648 // you need to find_and_remove it before returning.
649 // So be careful to not exit with a CHECK_ macro betweeen these calls.
650 //
651 // name must be in the form of "java/lang/Object" -- cannot be "Ljava/lang/Object;"
652 InstanceKlass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
653 Handle class_loader,
654 Handle protection_domain,
655 TRAPS) {
656 assert(name != NULL && !Signature::is_array(name) &&
657 !Signature::has_envelope(name), "invalid class name");
658
659 EventClassLoad class_load_start_event;
660
661 HandleMark hm(THREAD);
662
663 // Fix for 4474172; see evaluation for more details
664 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
665 ClassLoaderData* loader_data = register_loader(class_loader);
666 Dictionary* dictionary = loader_data->dictionary();
667 unsigned int d_hash = dictionary->compute_hash(name);
668
669 // Do lookup to see if class already exist and the protection domain
670 // has the right access
671 // This call uses find which checks protection domain already matches
672 // All subsequent calls use find_class, and set has_loaded_class so that
673 // before we return a result we call out to java to check for valid protection domain
674 // to allow returning the Klass* and add it to the pd_set if it is valid
675 {
676 InstanceKlass* probe = dictionary->find(d_hash, name, protection_domain);
677 if (probe != NULL) return probe;
678 }
679
680 // Non-bootstrap class loaders will call out to class loader and
681 // define via jvm/jni_DefineClass which will acquire the
682 // class loader object lock to protect against multiple threads
683 // defining the class in parallel by accident.
684 // This lock must be acquired here so the waiter will find
685 // any successful result in the SystemDictionary and not attempt
686 // the define.
687 // ParallelCapable Classloaders and the bootstrap classloader
688 // do not acquire lock here.
689 bool DoObjectLock = true;
690 if (is_parallelCapable(class_loader)) {
691 DoObjectLock = false;
692 }
693
694 unsigned int p_hash = placeholders()->compute_hash(name);
695 int p_index = placeholders()->hash_to_index(p_hash);
696
697 // Class is not in SystemDictionary so we have to do loading.
698 // Make sure we are synchronized on the class loader before we proceed
699 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
700 check_loader_lock_contention(lockObject, THREAD);
701 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
702
703 // Check again (after locking) if class already exist in SystemDictionary
704 bool class_has_been_loaded = false;
705 bool super_load_in_progress = false;
706 bool havesupername = false;
707 InstanceKlass* k = NULL;
708 PlaceholderEntry* placeholder;
709 Symbol* superclassname = NULL;
710
711 assert(THREAD->can_call_java(),
712 "can not load classes with compiler thread: class=%s, classloader=%s",
713 name->as_C_string(),
714 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string());
715 {
716 MutexLocker mu(THREAD, SystemDictionary_lock);
717 InstanceKlass* check = find_class(d_hash, name, dictionary);
718 if (check != NULL) {
719 // InstanceKlass is already loaded, so just return it
720 class_has_been_loaded = true;
721 k = check;
722 } else {
723 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
724 if (placeholder && placeholder->super_load_in_progress()) {
725 super_load_in_progress = true;
726 if (placeholder->havesupername() == true) {
727 superclassname = placeholder->supername();
728 havesupername = true;
729 }
730 }
731 }
732 }
733
734 // If the class is in the placeholder table, class loading is in progress
735 if (super_load_in_progress && havesupername==true) {
736 k = handle_parallel_super_load(name,
737 superclassname,
738 class_loader,
739 protection_domain,
740 lockObject, THREAD);
741 if (HAS_PENDING_EXCEPTION) {
742 return NULL;
743 }
744 if (k != NULL) {
745 class_has_been_loaded = true;
746 }
747 }
748
749 bool throw_circularity_error = false;
750 if (!class_has_been_loaded) {
751 bool load_instance_added = false;
752
753 // add placeholder entry to record loading instance class
754 // Five cases:
755 // All cases need to prevent modifying bootclasssearchpath
756 // in parallel with a classload of same classname
757 // Redefineclasses uses existence of the placeholder for the duration
758 // of the class load to prevent concurrent redefinition of not completely
759 // defined classes.
760 // case 1. traditional classloaders that rely on the classloader object lock
761 // - no other need for LOAD_INSTANCE
762 // case 2. traditional classloaders that break the classloader object lock
763 // as a deadlock workaround. Detection of this case requires that
764 // this check is done while holding the classloader object lock,
765 // and that lock is still held when calling classloader's loadClass.
766 // For these classloaders, we ensure that the first requestor
767 // completes the load and other requestors wait for completion.
768 // case 3. Bootstrap classloader - don't own objectLocker
769 // This classloader supports parallelism at the classloader level,
770 // but only allows a single load of a class/classloader pair.
771 // No performance benefit and no deadlock issues.
772 // case 4. parallelCapable user level classloaders - without objectLocker
773 // Allow parallel classloading of a class/classloader pair
774
775 {
776 MutexLocker mu(THREAD, SystemDictionary_lock);
777 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
778 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
779 if (oldprobe) {
780 // only need check_seen_thread once, not on each loop
781 // 6341374 java/lang/Instrument with -Xcomp
782 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
783 throw_circularity_error = true;
784 } else {
785 // case 1: traditional: should never see load_in_progress.
786 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
787
788 // case 3: bootstrap classloader: prevent futile classloading,
789 // wait on first requestor
790 if (class_loader.is_null()) {
791 SystemDictionary_lock->wait();
792 } else {
793 // case 2: traditional with broken classloader lock. wait on first
794 // requestor.
795 double_lock_wait(lockObject, THREAD);
796 }
797 // Check if classloading completed while we were waiting
798 InstanceKlass* check = find_class(d_hash, name, dictionary);
799 if (check != NULL) {
800 // Klass is already loaded, so just return it
801 k = check;
802 class_has_been_loaded = true;
803 }
804 // check if other thread failed to load and cleaned up
805 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
806 }
807 }
808 }
809 }
810 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
811 // case 4: parallelCapable: allow competing threads to try
812 // LOAD_INSTANCE in parallel
813
814 if (!throw_circularity_error && !class_has_been_loaded) {
815 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
816 load_instance_added = true;
817 // For class loaders that do not acquire the classloader object lock,
818 // if they did not catch another thread holding LOAD_INSTANCE,
819 // need a check analogous to the acquire ObjectLocker/find_class
820 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
821 // one final check if the load has already completed
822 // class loaders holding the ObjectLock shouldn't find the class here
823 InstanceKlass* check = find_class(d_hash, name, dictionary);
824 if (check != NULL) {
825 // Klass is already loaded, so return it after checking/adding protection domain
826 k = check;
827 class_has_been_loaded = true;
828 }
829 }
830 }
831
832 // must throw error outside of owning lock
833 if (throw_circularity_error) {
834 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
835 ResourceMark rm(THREAD);
836 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
837 }
838
839 if (!class_has_been_loaded) {
840
841 // Do actual loading
842 k = load_instance_class(name, class_loader, THREAD);
843
844 // If everything was OK (no exceptions, no null return value), and
845 // class_loader is NOT the defining loader, do a little more bookkeeping.
846 if (!HAS_PENDING_EXCEPTION && k != NULL &&
847 k->class_loader() != class_loader()) {
848
849 check_constraints(d_hash, k, class_loader, false, THREAD);
850
851 // Need to check for a PENDING_EXCEPTION again; check_constraints
852 // can throw but we may have to remove entry from the placeholder table below.
853 if (!HAS_PENDING_EXCEPTION) {
854 // Record dependency for non-parent delegation.
855 // This recording keeps the defining class loader of the klass (k) found
856 // from being unloaded while the initiating class loader is loaded
857 // even if the reference to the defining class loader is dropped
858 // before references to the initiating class loader.
859 loader_data->record_dependency(k);
860
861 { // Grabbing the Compile_lock prevents systemDictionary updates
862 // during compilations.
863 MutexLocker mu(THREAD, Compile_lock);
864 update_dictionary(d_hash, p_index, p_hash,
865 k, class_loader, THREAD);
866 }
867
868 if (JvmtiExport::should_post_class_load()) {
869 Thread *thread = THREAD;
870 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
871 JvmtiExport::post_class_load((JavaThread *) thread, k);
872 }
873 }
874 }
875 } // load_instance_class
876
877 if (load_instance_added == true) {
878 // clean up placeholder entries for LOAD_INSTANCE success or error
879 // This brackets the SystemDictionary updates for both defining
880 // and initiating loaders
881 MutexLocker mu(THREAD, SystemDictionary_lock);
882 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
883 SystemDictionary_lock->notify_all();
884 }
885 }
886
887 if (HAS_PENDING_EXCEPTION || k == NULL) {
888 return NULL;
889 }
890 if (class_load_start_event.should_commit()) {
891 post_class_load_event(&class_load_start_event, k, loader_data);
892 }
893 #ifdef ASSERT
894 {
895 ClassLoaderData* loader_data = k->class_loader_data();
896 MutexLocker mu(THREAD, SystemDictionary_lock);
897 InstanceKlass* kk = find_class(name, loader_data);
898 assert(kk == k, "should be present in dictionary");
899 }
900 #endif
901
902 // return if the protection domain in NULL
903 if (protection_domain() == NULL) return k;
904
905 // Check the protection domain has the right access
906 if (dictionary->is_valid_protection_domain(d_hash, name,
907 protection_domain)) {
908 return k;
909 }
910
911 // Verify protection domain. If it fails an exception is thrown
912 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
913
914 return k;
915 }
916
917
918 // This routine does not lock the system dictionary.
919 //
920 // Since readers don't hold a lock, we must make sure that system
921 // dictionary entries are only removed at a safepoint (when only one
922 // thread is running), and are added to in a safe way (all links must
923 // be updated in an MT-safe manner).
924 //
925 // Callers should be aware that an entry could be added just after
926 // _dictionary->bucket(index) is read here, so the caller will not see
927 // the new entry.
928
929 Klass* SystemDictionary::find(Symbol* class_name,
930 Handle class_loader,
931 Handle protection_domain,
932 TRAPS) {
933
934 // The result of this call should be consistent with the result
935 // of the call to resolve_instance_class_or_null().
936 // See evaluation 6790209 and 4474172 for more details.
937 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
938 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
939
940 if (loader_data == NULL) {
941 // If the ClassLoaderData has not been setup,
942 // then the class loader has no entries in the dictionary.
943 return NULL;
944 }
945
946 Dictionary* dictionary = loader_data->dictionary();
947 unsigned int d_hash = dictionary->compute_hash(class_name);
948 return dictionary->find(d_hash, class_name,
949 protection_domain);
950 }
951
952
953 // Look for a loaded instance or array klass by name. Do not do any loading.
954 // return NULL in case of error.
955 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
956 Handle class_loader,
957 Handle protection_domain,
958 TRAPS) {
959 Klass* k = NULL;
960 assert(class_name != NULL, "class name must be non NULL");
961
962 if (Signature::is_array(class_name)) {
963 // The name refers to an array. Parse the name.
964 // dimension and object_key in FieldArrayInfo are assigned as a
965 // side-effect of this call
966 SignatureStream ss(class_name, false);
967 int ndims = ss.skip_array_prefix(); // skip all '['s
968 BasicType t = ss.type();
969 if (t != T_OBJECT) {
970 k = Universe::typeArrayKlassObj(t);
971 } else {
972 k = SystemDictionary::find(ss.as_symbol(), class_loader, protection_domain, THREAD);
973 }
974 if (k != NULL) {
975 k = k->array_klass_or_null(ndims);
976 }
977 } else {
978 k = find(class_name, class_loader, protection_domain, THREAD);
979 }
980 return k;
981 }
982
983 // Note: this method is much like resolve_from_stream, but
984 // does not publish the classes via the SystemDictionary.
985 // Handles unsafe_DefineAnonymousClass and redefineclasses
986 // RedefinedClasses do not add to the class hierarchy
987 InstanceKlass* SystemDictionary::parse_stream(Symbol* class_name,
988 Handle class_loader,
989 Handle protection_domain,
990 ClassFileStream* st,
991 const InstanceKlass* unsafe_anonymous_host,
992 GrowableArray<Handle>* cp_patches,
993 TRAPS) {
994
995 EventClassLoad class_load_start_event;
996
997 ClassLoaderData* loader_data;
998 if (unsafe_anonymous_host != NULL) {
999 // Create a new CLD for an unsafe anonymous class, that uses the same class loader
1000 // as the unsafe_anonymous_host
1001 guarantee(unsafe_anonymous_host->class_loader() == class_loader(), "should be the same");
1002 loader_data = ClassLoaderData::unsafe_anonymous_class_loader_data(class_loader);
1003 } else {
1004 loader_data = ClassLoaderData::class_loader_data(class_loader());
1005 }
1006
1007 assert(st != NULL, "invariant");
1008 assert(st->need_verify(), "invariant");
1009
1010 // Parse stream and create a klass.
1011 // Note that we do this even though this klass might
1012 // already be present in the SystemDictionary, otherwise we would not
1013 // throw potential ClassFormatErrors.
1014
1015 InstanceKlass* k = KlassFactory::create_from_stream(st,
1016 class_name,
1017 loader_data,
1018 protection_domain,
1019 unsafe_anonymous_host,
1020 cp_patches,
1021 CHECK_NULL);
1022
1023 if (unsafe_anonymous_host != NULL && k != NULL) {
1024 // Unsafe anonymous classes must update ClassLoaderData holder (was unsafe_anonymous_host loader)
1025 // so that they can be unloaded when the mirror is no longer referenced.
1026 k->class_loader_data()->initialize_holder(Handle(THREAD, k->java_mirror()));
1027
1028 {
1029 MutexLocker mu_r(THREAD, Compile_lock);
1030
1031 // Add to class hierarchy, initialize vtables, and do possible
1032 // deoptimizations.
1033 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1034 // But, do not add to dictionary.
1035 }
1036
1037 // Rewrite and patch constant pool here.
1038 k->link_class(CHECK_NULL);
1039 if (cp_patches != NULL) {
1040 k->constants()->patch_resolved_references(cp_patches);
1041 }
1042
1043 // If it's anonymous, initialize it now, since nobody else will.
1044 k->eager_initialize(CHECK_NULL);
1045
1046 // notify jvmti
1047 if (JvmtiExport::should_post_class_load()) {
1048 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1049 JvmtiExport::post_class_load((JavaThread *) THREAD, k);
1050 }
1051 if (class_load_start_event.should_commit()) {
1052 post_class_load_event(&class_load_start_event, k, loader_data);
1053 }
1054 }
1055 assert(unsafe_anonymous_host != NULL || NULL == cp_patches,
1056 "cp_patches only found with unsafe_anonymous_host");
1057
1058 return k;
1059 }
1060
1061 // Add a klass to the system from a stream (called by jni_DefineClass and
1062 // JVM_DefineClass).
1063 // Note: class_name can be NULL. In that case we do not know the name of
1064 // the class until we have parsed the stream.
1065
1066 InstanceKlass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1067 Handle class_loader,
1068 Handle protection_domain,
1069 ClassFileStream* st,
1070 TRAPS) {
1071
1072 HandleMark hm(THREAD);
1073
1074 // Classloaders that support parallelism, e.g. bootstrap classloader,
1075 // do not acquire lock here
1076 bool DoObjectLock = true;
1077 if (is_parallelCapable(class_loader)) {
1078 DoObjectLock = false;
1079 }
1080
1081 ClassLoaderData* loader_data = register_loader(class_loader);
1082
1083 // Make sure we are synchronized on the class loader before we proceed
1084 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1085 check_loader_lock_contention(lockObject, THREAD);
1086 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1087
1088 assert(st != NULL, "invariant");
1089
1090 // Parse the stream and create a klass.
1091 // Note that we do this even though this klass might
1092 // already be present in the SystemDictionary, otherwise we would not
1093 // throw potential ClassFormatErrors.
1094 InstanceKlass* k = NULL;
1095
1096 #if INCLUDE_CDS
1097 if (!DumpSharedSpaces) {
1098 k = SystemDictionaryShared::lookup_from_stream(class_name,
1099 class_loader,
1100 protection_domain,
1101 st,
1102 CHECK_NULL);
1103 }
1104 #endif
1105
1106 if (k == NULL) {
1107 if (st->buffer() == NULL) {
1108 return NULL;
1109 }
1110 k = KlassFactory::create_from_stream(st,
1111 class_name,
1112 loader_data,
1113 protection_domain,
1114 NULL, // unsafe_anonymous_host
1115 NULL, // cp_patches
1116 CHECK_NULL);
1117 }
1118
1119 assert(k != NULL, "no klass created");
1120 Symbol* h_name = k->name();
1121 assert(class_name == NULL || class_name == h_name, "name mismatch");
1122
1123 // Add class just loaded
1124 // If a class loader supports parallel classloading handle parallel define requests
1125 // find_or_define_instance_class may return a different InstanceKlass
1126 if (is_parallelCapable(class_loader)) {
1127 InstanceKlass* defined_k = find_or_define_instance_class(h_name, class_loader, k, THREAD);
1128 if (!HAS_PENDING_EXCEPTION && defined_k != k) {
1129 // If a parallel capable class loader already defined this class, register 'k' for cleanup.
1130 assert(defined_k != NULL, "Should have a klass if there's no exception");
1131 loader_data->add_to_deallocate_list(k);
1132 k = defined_k;
1133 }
1134 } else {
1135 define_instance_class(k, THREAD);
1136 }
1137
1138 // If defining the class throws an exception register 'k' for cleanup.
1139 if (HAS_PENDING_EXCEPTION) {
1140 assert(k != NULL, "Must have an instance klass here!");
1141 loader_data->add_to_deallocate_list(k);
1142 return NULL;
1143 }
1144
1145 // Make sure we have an entry in the SystemDictionary on success
1146 debug_only( {
1147 MutexLocker mu(THREAD, SystemDictionary_lock);
1148
1149 Klass* check = find_class(h_name, k->class_loader_data());
1150 assert(check == k, "should be present in the dictionary");
1151 } );
1152
1153 return k;
1154 }
1155
1156 #if INCLUDE_CDS
1157 // Load a class for boot loader from the shared spaces. This also
1158 // forces the super class and all interfaces to be loaded.
1159 InstanceKlass* SystemDictionary::load_shared_boot_class(Symbol* class_name,
1160 PackageEntry* pkg_entry,
1161 TRAPS) {
1162 InstanceKlass* ik = SystemDictionaryShared::find_builtin_class(class_name);
1163 if (ik != NULL && ik->is_shared_boot_class()) {
1164 return load_shared_class(ik, Handle(), Handle(), NULL, pkg_entry, THREAD);
1165 }
1166 return NULL;
1167 }
1168
1169 // Check if a shared class can be loaded by the specific classloader:
1170 //
1171 // NULL classloader:
1172 // - Module class from "modules" jimage. ModuleEntry must be defined in the classloader.
1173 // - Class from -Xbootclasspath/a. The class has no defined PackageEntry, or must
1174 // be defined in an unnamed module.
1175 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
1176 InstanceKlass* ik,
1177 PackageEntry* pkg_entry,
1178 Handle class_loader, TRAPS) {
1179 assert(!ModuleEntryTable::javabase_moduleEntry()->is_patched(),
1180 "Cannot use sharing if java.base is patched");
1181 ResourceMark rm(THREAD);
1182 int path_index = ik->shared_classpath_index();
1183 ClassLoaderData* loader_data = class_loader_data(class_loader);
1184 if (path_index < 0) {
1185 // path_index < 0 indicates that the class is intended for a custom loader
1186 // and should not be loaded by boot/platform/app loaders
1187 if (loader_data->is_builtin_class_loader_data()) {
1188 return false;
1189 } else {
1190 return true;
1191 }
1192 }
1193 SharedClassPathEntry* ent =
1194 (SharedClassPathEntry*)FileMapInfo::shared_path(path_index);
1195 if (!Universe::is_module_initialized()) {
1196 assert(ent != NULL && ent->is_modules_image(),
1197 "Loading non-bootstrap classes before the module system is initialized");
1198 assert(class_loader.is_null(), "sanity");
1199 return true;
1200 }
1201 // Get the pkg_entry from the classloader
1202 ModuleEntry* mod_entry = NULL;
1203 TempNewSymbol pkg_name = pkg_entry != NULL ? pkg_entry->name() :
1204 ClassLoader::package_from_class_name(class_name);
1205 if (pkg_name != NULL) {
1206 if (loader_data != NULL) {
1207 if (pkg_entry != NULL) {
1208 mod_entry = pkg_entry->module();
1209 // If the archived class is from a module that has been patched at runtime,
1210 // the class cannot be loaded from the archive.
1211 if (mod_entry != NULL && mod_entry->is_patched()) {
1212 return false;
1213 }
1214 }
1215 }
1216 }
1217
1218 if (class_loader.is_null()) {
1219 assert(ent != NULL, "Shared class for NULL classloader must have valid SharedClassPathEntry");
1220 // The NULL classloader can load archived class originated from the
1221 // "modules" jimage and the -Xbootclasspath/a. For class from the
1222 // "modules" jimage, the PackageEntry/ModuleEntry must be defined
1223 // by the NULL classloader.
1224 if (mod_entry != NULL) {
1225 // PackageEntry/ModuleEntry is found in the classloader. Check if the
1226 // ModuleEntry's location agrees with the archived class' origination.
1227 if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
1228 return true; // Module class from the "module" jimage
1229 }
1230 }
1231
1232 // If the archived class is not from the "module" jimage, the class can be
1233 // loaded by the NULL classloader if
1234 //
1235 // 1. the class is from the unamed package
1236 // 2. or, the class is not from a module defined in the NULL classloader
1237 // 3. or, the class is from an unamed module
1238 if (!ent->is_modules_image() && ik->is_shared_boot_class()) {
1239 // the class is from the -Xbootclasspath/a
1240 if (pkg_name == NULL ||
1241 pkg_entry == NULL ||
1242 pkg_entry->in_unnamed_module()) {
1243 assert(mod_entry == NULL ||
1244 mod_entry == loader_data->unnamed_module(),
1245 "the unnamed module is not defined in the classloader");
1246 return true;
1247 }
1248 }
1249 return false;
1250 } else {
1251 bool res = SystemDictionaryShared::is_shared_class_visible_for_classloader(
1252 ik, class_loader, pkg_name, pkg_entry, mod_entry, CHECK_(false));
1253 return res;
1254 }
1255 }
1256
1257 bool SystemDictionary::check_shared_class_super_type(InstanceKlass* child, InstanceKlass* super_type,
1258 Handle class_loader, Handle protection_domain,
1259 bool is_superclass, TRAPS) {
1260 assert(super_type->is_shared(), "must be");
1261
1262 Klass *found = resolve_super_or_fail(child->name(), super_type->name(),
1263 class_loader, protection_domain, is_superclass, CHECK_0);
1264 if (found == super_type) {
1265 return true;
1266 } else {
1267 // The dynamically resolved super type is not the same as the one we used during dump time,
1268 // so we cannot use the child class.
1269 return false;
1270 }
1271 }
1272
1273 bool SystemDictionary::check_shared_class_super_types(InstanceKlass* ik, Handle class_loader,
1274 Handle protection_domain, TRAPS) {
1275 // Check the superclass and interfaces. They must be the same
1276 // as in dump time, because the layout of <ik> depends on
1277 // the specific layout of ik->super() and ik->local_interfaces().
1278 //
1279 // If unexpected superclass or interfaces are found, we cannot
1280 // load <ik> from the shared archive.
1281
1282 if (ik->super() != NULL &&
1283 !check_shared_class_super_type(ik, InstanceKlass::cast(ik->super()),
1284 class_loader, protection_domain, true, THREAD)) {
1285 return false;
1286 }
1287
1288 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
1289 int num_interfaces = interfaces->length();
1290 for (int index = 0; index < num_interfaces; index++) {
1291 if (!check_shared_class_super_type(ik, interfaces->at(index), class_loader, protection_domain, false, THREAD)) {
1292 return false;
1293 }
1294 }
1295
1296 return true;
1297 }
1298
1299 InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
1300 Handle class_loader,
1301 Handle protection_domain,
1302 const ClassFileStream *cfs,
1303 PackageEntry* pkg_entry,
1304 TRAPS) {
1305 assert(ik != NULL, "sanity");
1306 assert(!ik->is_unshareable_info_restored(), "shared class can be loaded only once");
1307 Symbol* class_name = ik->name();
1308
1309 bool visible = is_shared_class_visible(
1310 class_name, ik, pkg_entry, class_loader, CHECK_NULL);
1311 if (!visible) {
1312 return NULL;
1313 }
1314
1315 if (!check_shared_class_super_types(ik, class_loader, protection_domain, THREAD)) {
1316 return NULL;
1317 }
1318
1319 InstanceKlass* new_ik = KlassFactory::check_shared_class_file_load_hook(
1320 ik, class_name, class_loader, protection_domain, cfs, CHECK_NULL);
1321 if (new_ik != NULL) {
1322 // The class is changed by CFLH. Return the new class. The shared class is
1323 // not used.
1324 return new_ik;
1325 }
1326
1327 // Adjust methods to recover missing data. They need addresses for
1328 // interpreter entry points and their default native method address
1329 // must be reset.
1330
1331 // Updating methods must be done under a lock so multiple
1332 // threads don't update these in parallel
1333 //
1334 // Shared classes are all currently loaded by either the bootstrap or
1335 // internal parallel class loaders, so this will never cause a deadlock
1336 // on a custom class loader lock.
1337
1338 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1339 {
1340 HandleMark hm(THREAD);
1341 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1342 check_loader_lock_contention(lockObject, THREAD);
1343 ObjectLocker ol(lockObject, THREAD, true);
1344 // prohibited package check assumes all classes loaded from archive call
1345 // restore_unshareable_info which calls ik->set_package()
1346 ik->restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK_NULL);
1347 }
1348
1349 load_shared_class_misc(ik, loader_data, CHECK_NULL);
1350 return ik;
1351 }
1352
1353 void SystemDictionary::load_shared_class_misc(InstanceKlass* ik, ClassLoaderData* loader_data, TRAPS) {
1354 ik->print_class_load_logging(loader_data, NULL, NULL);
1355
1356 // For boot loader, ensure that GetSystemPackage knows that a class in this
1357 // package was loaded.
1358 if (loader_data->is_the_null_class_loader_data()) {
1359 int path_index = ik->shared_classpath_index();
1360 ClassLoader::add_package(ik, path_index, THREAD);
1361 }
1362
1363 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1364 // Only dump the classes that can be stored into CDS archive
1365 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1366 ResourceMark rm(THREAD);
1367 classlist_file->print_cr("%s", ik->name()->as_C_string());
1368 classlist_file->flush();
1369 }
1370 }
1371
1372 // notify a class loaded from shared object
1373 ClassLoadingService::notify_class_loaded(ik, true /* shared class */);
1374
1375 ik->set_has_passed_fingerprint_check(false);
1376 if (UseAOT && ik->supers_have_passed_fingerprint_checks()) {
1377 uint64_t aot_fp = AOTLoader::get_saved_fingerprint(ik);
1378 uint64_t cds_fp = ik->get_stored_fingerprint();
1379 if (aot_fp != 0 && aot_fp == cds_fp) {
1380 // This class matches with a class saved in an AOT library
1381 ik->set_has_passed_fingerprint_check(true);
1382 } else {
1383 if (log_is_enabled(Info, class, fingerprint)) {
1384 ResourceMark rm(THREAD);
1385 log_info(class, fingerprint)("%s : expected = " PTR64_FORMAT " actual = " PTR64_FORMAT, ik->external_name(), aot_fp, cds_fp);
1386 }
1387 }
1388 }
1389 }
1390
1391 void SystemDictionary::quick_resolve(InstanceKlass* klass, ClassLoaderData* loader_data, Handle domain, TRAPS) {
1392 assert(!Universe::is_fully_initialized(), "We can make short cuts only during VM initialization");
1393 assert(klass->is_shared(), "Must be shared class");
1394 if (klass->class_loader_data() != NULL) {
1395 return;
1396 }
1397
1398 // add super and interfaces first
1399 Klass* super = klass->super();
1400 if (super != NULL && super->class_loader_data() == NULL) {
1401 assert(super->is_instance_klass(), "Super should be instance klass");
1402 quick_resolve(InstanceKlass::cast(super), loader_data, domain, CHECK);
1403 }
1404
1405 Array<InstanceKlass*>* ifs = klass->local_interfaces();
1406 for (int i = 0; i < ifs->length(); i++) {
1407 InstanceKlass* ik = ifs->at(i);
1408 if (ik->class_loader_data() == NULL) {
1409 quick_resolve(ik, loader_data, domain, CHECK);
1410 }
1411 }
1412
1413 klass->restore_unshareable_info(loader_data, domain, NULL, THREAD);
1414 load_shared_class_misc(klass, loader_data, CHECK);
1415 Dictionary* dictionary = loader_data->dictionary();
1416 unsigned int hash = dictionary->compute_hash(klass->name());
1417 dictionary->add_klass(hash, klass->name(), klass);
1418 add_to_hierarchy(klass, CHECK);
1419 assert(klass->is_loaded(), "Must be in at least loaded state");
1420 }
1421 #endif // INCLUDE_CDS
1422
1423 InstanceKlass* SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1424
1425 if (class_loader.is_null()) {
1426 ResourceMark rm(THREAD);
1427 PackageEntry* pkg_entry = NULL;
1428 bool search_only_bootloader_append = false;
1429 ClassLoaderData *loader_data = class_loader_data(class_loader);
1430
1431 // Find the package in the boot loader's package entry table.
1432 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
1433 if (pkg_name != NULL) {
1434 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1435 }
1436
1437 // Prior to attempting to load the class, enforce the boot loader's
1438 // visibility boundaries.
1439 if (!Universe::is_module_initialized()) {
1440 // During bootstrapping, prior to module initialization, any
1441 // class attempting to be loaded must be checked against the
1442 // java.base packages in the boot loader's PackageEntryTable.
1443 // No class outside of java.base is allowed to be loaded during
1444 // this bootstrapping window.
1445 if (pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1446 // Class is either in the unnamed package or in
1447 // a named package within the unnamed module. Either
1448 // case is outside of java.base, do not attempt to
1449 // load the class post java.base definition. If
1450 // java.base has not been defined, let the class load
1451 // and its package will be checked later by
1452 // ModuleEntryTable::verify_javabase_packages.
1453 if (ModuleEntryTable::javabase_defined()) {
1454 return NULL;
1455 }
1456 } else {
1457 // Check that the class' package is defined within java.base.
1458 ModuleEntry* mod_entry = pkg_entry->module();
1459 Symbol* mod_entry_name = mod_entry->name();
1460 if (mod_entry_name->fast_compare(vmSymbols::java_base()) != 0) {
1461 return NULL;
1462 }
1463 }
1464 } else {
1465 // After the module system has been initialized, check if the class'
1466 // package is in a module defined to the boot loader.
1467 if (pkg_name == NULL || pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1468 // Class is either in the unnamed package, in a named package
1469 // within a module not defined to the boot loader or in a
1470 // a named package within the unnamed module. In all cases,
1471 // limit visibility to search for the class only in the boot
1472 // loader's append path.
1473 if (!ClassLoader::has_bootclasspath_append()) {
1474 // If there is no bootclasspath append entry, no need to continue
1475 // searching.
1476 return NULL;
1477 }
1478 search_only_bootloader_append = true;
1479 }
1480 }
1481
1482 // Prior to bootstrapping's module initialization, never load a class outside
1483 // of the boot loader's module path
1484 assert(Universe::is_module_initialized() ||
1485 !search_only_bootloader_append,
1486 "Attempt to load a class outside of boot loader's module path");
1487
1488 // Search for classes in the CDS archive.
1489 InstanceKlass* k = NULL;
1490 {
1491 #if INCLUDE_CDS
1492 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1493 k = load_shared_boot_class(class_name, pkg_entry, THREAD);
1494 #endif
1495 }
1496
1497 if (k == NULL) {
1498 // Use VM class loader
1499 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1500 k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_NULL);
1501 }
1502
1503 // find_or_define_instance_class may return a different InstanceKlass
1504 if (k != NULL) {
1505 InstanceKlass* defined_k =
1506 find_or_define_instance_class(class_name, class_loader, k, THREAD);
1507 if (!HAS_PENDING_EXCEPTION && defined_k != k) {
1508 // If a parallel capable class loader already defined this class, register 'k' for cleanup.
1509 assert(defined_k != NULL, "Should have a klass if there's no exception");
1510 loader_data->add_to_deallocate_list(k);
1511 k = defined_k;
1512 } else if (HAS_PENDING_EXCEPTION) {
1513 loader_data->add_to_deallocate_list(k);
1514 return NULL;
1515 }
1516 }
1517 return k;
1518 } else {
1519 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1520 ResourceMark rm(THREAD);
1521
1522 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1523 JavaThread* jt = (JavaThread*) THREAD;
1524
1525 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1526 ClassLoader::perf_app_classload_selftime(),
1527 ClassLoader::perf_app_classload_count(),
1528 jt->get_thread_stat()->perf_recursion_counts_addr(),
1529 jt->get_thread_stat()->perf_timers_addr(),
1530 PerfClassTraceTime::CLASS_LOAD);
1531
1532 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_NULL);
1533 // Translate to external class name format, i.e., convert '/' chars to '.'
1534 Handle string = java_lang_String::externalize_classname(s, CHECK_NULL);
1535
1536 JavaValue result(T_OBJECT);
1537
1538 InstanceKlass* spec_klass = SystemDictionary::ClassLoader_klass();
1539
1540 // Call public unsynchronized loadClass(String) directly for all class loaders.
1541 // For parallelCapable class loaders, JDK >=7, loadClass(String, boolean) will
1542 // acquire a class-name based lock rather than the class loader object lock.
1543 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean).
1544 JavaCalls::call_virtual(&result,
1545 class_loader,
1546 spec_klass,
1547 vmSymbols::loadClass_name(),
1548 vmSymbols::string_class_signature(),
1549 string,
1550 CHECK_NULL);
1551
1552 assert(result.get_type() == T_OBJECT, "just checking");
1553 oop obj = (oop) result.get_jobject();
1554
1555 // Primitive classes return null since forName() can not be
1556 // used to obtain any of the Class objects representing primitives or void
1557 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1558 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(obj));
1559 // For user defined Java class loaders, check that the name returned is
1560 // the same as that requested. This check is done for the bootstrap
1561 // loader when parsing the class file.
1562 if (class_name == k->name()) {
1563 return k;
1564 }
1565 }
1566 // Class is not found or has the wrong name, return NULL
1567 return NULL;
1568 }
1569 }
1570
1571 static void post_class_define_event(InstanceKlass* k, const ClassLoaderData* def_cld) {
1572 EventClassDefine event;
1573 if (event.should_commit()) {
1574 event.set_definedClass(k);
1575 event.set_definingClassLoader(def_cld);
1576 event.commit();
1577 }
1578 }
1579
1580 void SystemDictionary::define_instance_class(InstanceKlass* k, TRAPS) {
1581
1582 HandleMark hm(THREAD);
1583 ClassLoaderData* loader_data = k->class_loader_data();
1584 Handle class_loader_h(THREAD, loader_data->class_loader());
1585
1586 // for bootstrap and other parallel classloaders don't acquire lock,
1587 // use placeholder token
1588 // If a parallelCapable class loader calls define_instance_class instead of
1589 // find_or_define_instance_class to get here, we have a timing
1590 // hole with systemDictionary updates and check_constraints
1591 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1592 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1593 compute_loader_lock_object(class_loader_h, THREAD)),
1594 "define called without lock");
1595 }
1596
1597 // Check class-loading constraints. Throw exception if violation is detected.
1598 // Grabs and releases SystemDictionary_lock
1599 // The check_constraints/find_class call and update_dictionary sequence
1600 // must be "atomic" for a specific class/classloader pair so we never
1601 // define two different instanceKlasses for that class/classloader pair.
1602 // Existing classloaders will call define_instance_class with the
1603 // classloader lock held
1604 // Parallel classloaders will call find_or_define_instance_class
1605 // which will require a token to perform the define class
1606 Symbol* name_h = k->name();
1607 Dictionary* dictionary = loader_data->dictionary();
1608 unsigned int d_hash = dictionary->compute_hash(name_h);
1609 check_constraints(d_hash, k, class_loader_h, true, CHECK);
1610
1611 // Register class just loaded with class loader (placed in ArrayList)
1612 // Note we do this before updating the dictionary, as this can
1613 // fail with an OutOfMemoryError (if it does, we will *not* put this
1614 // class in the dictionary and will not update the class hierarchy).
1615 // JVMTI FollowReferences needs to find the classes this way.
1616 if (k->class_loader() != NULL) {
1617 methodHandle m(THREAD, Universe::loader_addClass_method());
1618 JavaValue result(T_VOID);
1619 JavaCallArguments args(class_loader_h);
1620 args.push_oop(Handle(THREAD, k->java_mirror()));
1621 JavaCalls::call(&result, m, &args, CHECK);
1622 }
1623
1624 // Add the new class. We need recompile lock during update of CHA.
1625 {
1626 unsigned int p_hash = placeholders()->compute_hash(name_h);
1627 int p_index = placeholders()->hash_to_index(p_hash);
1628
1629 MutexLocker mu_r(THREAD, Compile_lock);
1630
1631 // Add to class hierarchy, initialize vtables, and do possible
1632 // deoptimizations.
1633 add_to_hierarchy(k, CHECK); // No exception, but can block
1634
1635 // Add to systemDictionary - so other classes can see it.
1636 // Grabs and releases SystemDictionary_lock
1637 update_dictionary(d_hash, p_index, p_hash,
1638 k, class_loader_h, THREAD);
1639 }
1640 k->eager_initialize(THREAD);
1641
1642 // notify jvmti
1643 if (JvmtiExport::should_post_class_load()) {
1644 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1645 JvmtiExport::post_class_load((JavaThread *) THREAD, k);
1646
1647 }
1648 post_class_define_event(k, loader_data);
1649 }
1650
1651 // Support parallel classloading
1652 // All parallel class loaders, including bootstrap classloader
1653 // lock a placeholder entry for this class/class_loader pair
1654 // to allow parallel defines of different classes for this class loader
1655 // With AllowParallelDefine flag==true, in case they do not synchronize around
1656 // FindLoadedClass/DefineClass, calls, we check for parallel
1657 // loading for them, wait if a defineClass is in progress
1658 // and return the initial requestor's results
1659 // This flag does not apply to the bootstrap classloader.
1660 // With AllowParallelDefine flag==false, call through to define_instance_class
1661 // which will throw LinkageError: duplicate class definition.
1662 // False is the requested default.
1663 // For better performance, the class loaders should synchronize
1664 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1665 // potentially waste time reading and parsing the bytestream.
1666 // Note: VM callers should ensure consistency of k/class_name,class_loader
1667 // Be careful when modifying this code: once you have run
1668 // placeholders()->find_and_add(PlaceholderTable::DEFINE_CLASS),
1669 // you need to find_and_remove it before returning.
1670 // So be careful to not exit with a CHECK_ macro betweeen these calls.
1671 InstanceKlass* SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader,
1672 InstanceKlass* k, TRAPS) {
1673
1674 Symbol* name_h = k->name(); // passed in class_name may be null
1675 ClassLoaderData* loader_data = class_loader_data(class_loader);
1676 Dictionary* dictionary = loader_data->dictionary();
1677
1678 unsigned int d_hash = dictionary->compute_hash(name_h);
1679
1680 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1681 unsigned int p_hash = placeholders()->compute_hash(name_h);
1682 int p_index = placeholders()->hash_to_index(p_hash);
1683 PlaceholderEntry* probe;
1684
1685 {
1686 MutexLocker mu(THREAD, SystemDictionary_lock);
1687 // First check if class already defined
1688 if (is_parallelDefine(class_loader)) {
1689 InstanceKlass* check = find_class(d_hash, name_h, dictionary);
1690 if (check != NULL) {
1691 return check;
1692 }
1693 }
1694
1695 // Acquire define token for this class/classloader
1696 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1697 // Wait if another thread defining in parallel
1698 // All threads wait - even those that will throw duplicate class: otherwise
1699 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1700 // if other thread has not finished updating dictionary
1701 while (probe->definer() != NULL) {
1702 SystemDictionary_lock->wait();
1703 }
1704 // Only special cases allow parallel defines and can use other thread's results
1705 // Other cases fall through, and may run into duplicate defines
1706 // caught by finding an entry in the SystemDictionary
1707 if (is_parallelDefine(class_loader) && (probe->instance_klass() != NULL)) {
1708 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1709 SystemDictionary_lock->notify_all();
1710 #ifdef ASSERT
1711 InstanceKlass* check = find_class(d_hash, name_h, dictionary);
1712 assert(check != NULL, "definer missed recording success");
1713 #endif
1714 return probe->instance_klass();
1715 } else {
1716 // This thread will define the class (even if earlier thread tried and had an error)
1717 probe->set_definer(THREAD);
1718 }
1719 }
1720
1721 define_instance_class(k, THREAD);
1722
1723 Handle linkage_exception = Handle(); // null handle
1724
1725 // definer must notify any waiting threads
1726 {
1727 MutexLocker mu(THREAD, SystemDictionary_lock);
1728 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1729 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1730 if (probe != NULL) {
1731 if (HAS_PENDING_EXCEPTION) {
1732 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1733 CLEAR_PENDING_EXCEPTION;
1734 } else {
1735 probe->set_instance_klass(k);
1736 }
1737 probe->set_definer(NULL);
1738 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1739 SystemDictionary_lock->notify_all();
1740 }
1741 }
1742
1743 // Can't throw exception while holding lock due to rank ordering
1744 if (linkage_exception() != NULL) {
1745 THROW_OOP_(linkage_exception(), NULL); // throws exception and returns
1746 }
1747
1748 return k;
1749 }
1750
1751 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1752 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1753 if (class_loader.is_null()) {
1754 return Handle(THREAD, _system_loader_lock_obj);
1755 } else {
1756 return class_loader;
1757 }
1758 }
1759
1760 // This method is added to check how often we have to wait to grab loader
1761 // lock. The results are being recorded in the performance counters defined in
1762 // ClassLoader::_sync_systemLoaderLockContentionRate and
1763 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1764 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1765 if (!UsePerfData) {
1766 return;
1767 }
1768
1769 assert(!loader_lock.is_null(), "NULL lock object");
1770
1771 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1772 == ObjectSynchronizer::owner_other) {
1773 // contention will likely happen, so increment the corresponding
1774 // contention counter.
1775 if (loader_lock() == _system_loader_lock_obj) {
1776 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1777 } else {
1778 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1779 }
1780 }
1781 }
1782
1783 // ----------------------------------------------------------------------------
1784 // Lookup
1785
1786 InstanceKlass* SystemDictionary::find_class(unsigned int hash,
1787 Symbol* class_name,
1788 Dictionary* dictionary) {
1789 assert_locked_or_safepoint(SystemDictionary_lock);
1790 int index = dictionary->hash_to_index(hash);
1791 return dictionary->find_class(index, hash, class_name);
1792 }
1793
1794
1795 // Basic find on classes in the midst of being loaded
1796 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1797 ClassLoaderData* loader_data) {
1798 assert_locked_or_safepoint(SystemDictionary_lock);
1799 unsigned int p_hash = placeholders()->compute_hash(class_name);
1800 int p_index = placeholders()->hash_to_index(p_hash);
1801 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1802 }
1803
1804
1805 // Used for assertions and verification only
1806 // Precalculating the hash and index is an optimization because there are many lookups
1807 // before adding the class.
1808 InstanceKlass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1809 assert_locked_or_safepoint(SystemDictionary_lock);
1810 #ifndef ASSERT
1811 guarantee(VerifyBeforeGC ||
1812 VerifyDuringGC ||
1813 VerifyBeforeExit ||
1814 VerifyDuringStartup ||
1815 VerifyAfterGC, "too expensive");
1816 #endif
1817
1818 Dictionary* dictionary = loader_data->dictionary();
1819 unsigned int d_hash = dictionary->compute_hash(class_name);
1820 return find_class(d_hash, class_name, dictionary);
1821 }
1822
1823
1824 // ----------------------------------------------------------------------------
1825 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1826 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1827 // before a new class is used.
1828
1829 void SystemDictionary::add_to_hierarchy(InstanceKlass* k, TRAPS) {
1830 assert(k != NULL, "just checking");
1831 if (Universe::is_fully_initialized()) {
1832 assert_locked_or_safepoint(Compile_lock);
1833 }
1834
1835 k->set_init_state(InstanceKlass::loaded);
1836 // make sure init_state store is already done.
1837 // The compiler reads the hierarchy outside of the Compile_lock.
1838 // Access ordering is used to add to hierarchy.
1839
1840 // Link into hierachy.
1841 k->append_to_sibling_list(); // add to superklass/sibling list
1842 k->process_interfaces(THREAD); // handle all "implements" declarations
1843
1844 // Now flush all code that depended on old class hierarchy.
1845 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1846 if (Universe::is_fully_initialized()) {
1847 CodeCache::flush_dependents_on(k);
1848 }
1849 }
1850
1851 // ----------------------------------------------------------------------------
1852 // GC support
1853
1854 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1855 // Note: anonymous classes are not in the SD.
1856 bool SystemDictionary::do_unloading(GCTimer* gc_timer) {
1857
1858 bool unloading_occurred;
1859 bool is_concurrent = !SafepointSynchronize::is_at_safepoint();
1860 {
1861 GCTraceTime(Debug, gc, phases) t("ClassLoaderData", gc_timer);
1862 assert_locked_or_safepoint(ClassLoaderDataGraph_lock); // caller locks.
1863 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1864 unloading_occurred = ClassLoaderDataGraph::do_unloading();
1865 if (unloading_occurred) {
1866 MutexLocker ml2(is_concurrent ? Module_lock : NULL);
1867 JFR_ONLY(Jfr::on_unloading_classes();)
1868
1869 MutexLocker ml1(is_concurrent ? SystemDictionary_lock : NULL);
1870 ClassLoaderDataGraph::clean_module_and_package_info();
1871 constraints()->purge_loader_constraints();
1872 resolution_errors()->purge_resolution_errors();
1873 }
1874 }
1875
1876 GCTraceTime(Debug, gc, phases) t("Trigger cleanups", gc_timer);
1877
1878 if (unloading_occurred) {
1879 SymbolTable::trigger_cleanup();
1880
1881 // Oops referenced by the protection domain cache table may get unreachable independently
1882 // of the class loader (eg. cached protection domain oops). So we need to
1883 // explicitly unlink them here.
1884 // All protection domain oops are linked to the caller class, so if nothing
1885 // unloads, this is not needed.
1886 _pd_cache_table->trigger_cleanup();
1887 }
1888
1889 return unloading_occurred;
1890 }
1891
1892 void SystemDictionary::oops_do(OopClosure* f, bool include_handles) {
1893 f->do_oop(&_java_system_loader);
1894 f->do_oop(&_java_platform_loader);
1895 f->do_oop(&_system_loader_lock_obj);
1896 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1897
1898 // Visit extra methods
1899 invoke_method_table()->oops_do(f);
1900
1901 if (include_handles) {
1902 OopStorageSet::vm_global()->oops_do(f);
1903 }
1904 }
1905
1906 // CDS: scan and relocate all classes referenced by _well_known_klasses[].
1907 void SystemDictionary::well_known_klasses_do(MetaspaceClosure* it) {
1908 for (int id = FIRST_WKID; id < WKID_LIMIT; id++) {
1909 it->push(well_known_klass_addr((WKID)id));
1910 }
1911 }
1912
1913 void SystemDictionary::methods_do(void f(Method*)) {
1914 // Walk methods in loaded classes
1915 MutexLocker ml(ClassLoaderDataGraph_lock);
1916 ClassLoaderDataGraph::methods_do(f);
1917 // Walk method handle intrinsics
1918 invoke_method_table()->methods_do(f);
1919 }
1920
1921 // ----------------------------------------------------------------------------
1922 // Initialization
1923
1924 void SystemDictionary::initialize(TRAPS) {
1925 // Allocate arrays
1926 _placeholders = new PlaceholderTable(_placeholder_table_size);
1927 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1928 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1929 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
1930 _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
1931
1932 // Allocate private object used as system class loader lock
1933 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
1934 // Initialize basic classes
1935 resolve_well_known_classes(CHECK);
1936 }
1937
1938 // Compact table of directions on the initialization of klasses:
1939 static const short wk_init_info[] = {
1940 #define WK_KLASS_INIT_INFO(name, symbol) \
1941 ((short)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol)),
1942
1943 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1944 #undef WK_KLASS_INIT_INFO
1945 0
1946 };
1947
1948 #ifdef ASSERT
1949 bool SystemDictionary::is_well_known_klass(Symbol* class_name) {
1950 int sid;
1951 for (int i = 0; (sid = wk_init_info[i]) != 0; i++) {
1952 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1953 if (class_name == symbol) {
1954 return true;
1955 }
1956 }
1957 return false;
1958 }
1959 #endif
1960
1961 bool SystemDictionary::resolve_wk_klass(WKID id, TRAPS) {
1962 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1963 int sid = wk_init_info[id - FIRST_WKID];
1964 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1965 InstanceKlass** klassp = &_well_known_klasses[id];
1966
1967 #if INCLUDE_CDS
1968 if (UseSharedSpaces && !JvmtiExport::should_post_class_prepare()) {
1969 InstanceKlass* k = *klassp;
1970 assert(k->is_shared_boot_class(), "must be");
1971
1972 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1973 quick_resolve(k, loader_data, Handle(), CHECK_false);
1974 return true;
1975 }
1976 #endif // INCLUDE_CDS
1977
1978 if (!is_wk_klass_loaded(*klassp)) {
1979 Klass* k = resolve_or_fail(symbol, true, CHECK_false);
1980 (*klassp) = InstanceKlass::cast(k);
1981 }
1982 return ((*klassp) != NULL);
1983 }
1984
1985 void SystemDictionary::resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1986 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1987 for (int id = (int)start_id; id < (int)limit_id; id++) {
1988 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1989 resolve_wk_klass((WKID)id, CHECK);
1990 }
1991
1992 // move the starting value forward to the limit:
1993 start_id = limit_id;
1994 }
1995
1996 void SystemDictionary::resolve_well_known_classes(TRAPS) {
1997 assert(!Object_klass_loaded(), "well-known classes should only be initialized once");
1998
1999 // Create the ModuleEntry for java.base. This call needs to be done here,
2000 // after vmSymbols::initialize() is called but before any classes are pre-loaded.
2001 ClassLoader::classLoader_init2(CHECK);
2002
2003 // Preload commonly used klasses
2004 WKID scan = FIRST_WKID;
2005 // first do Object, then String, Class
2006 #if INCLUDE_CDS
2007 if (UseSharedSpaces) {
2008 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
2009
2010 // It's unsafe to access the archived heap regions before they
2011 // are fixed up, so we must do the fixup as early as possible
2012 // before the archived java objects are accessed by functions
2013 // such as java_lang_Class::restore_archived_mirror and
2014 // ConstantPool::restore_unshareable_info (restores the archived
2015 // resolved_references array object).
2016 //
2017 // HeapShared::fixup_mapped_heap_regions() fills the empty
2018 // spaces in the archived heap regions and may use
2019 // SystemDictionary::Object_klass(), so we can do this only after
2020 // Object_klass is resolved. See the above resolve_wk_klasses_through()
2021 // call. No mirror objects are accessed/restored in the above call.
2022 // Mirrors are restored after java.lang.Class is loaded.
2023 HeapShared::fixup_mapped_heap_regions();
2024
2025 // Initialize the constant pool for the Object_class
2026 assert(Object_klass()->is_shared(), "must be");
2027 Object_klass()->constants()->restore_unshareable_info(CHECK);
2028 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2029 } else
2030 #endif
2031 {
2032 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2033 }
2034
2035 assert(WK_KLASS(Object_klass) != NULL, "well-known classes should now be initialized");
2036
2037 java_lang_Object::register_natives(CHECK);
2038
2039 // Calculate offsets for String and Class classes since they are loaded and
2040 // can be used after this point.
2041 java_lang_String::compute_offsets();
2042 java_lang_Class::compute_offsets();
2043
2044 // Fixup mirrors for classes loaded before java.lang.Class.
2045 Universe::initialize_basic_type_mirrors(CHECK);
2046 Universe::fixup_mirrors(CHECK);
2047
2048 // do a bunch more:
2049 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
2050
2051 // Preload ref klasses and set reference types
2052 WK_KLASS(Reference_klass)->set_reference_type(REF_OTHER);
2053 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
2054
2055 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
2056 WK_KLASS(SoftReference_klass)->set_reference_type(REF_SOFT);
2057 WK_KLASS(WeakReference_klass)->set_reference_type(REF_WEAK);
2058 WK_KLASS(FinalReference_klass)->set_reference_type(REF_FINAL);
2059 WK_KLASS(PhantomReference_klass)->set_reference_type(REF_PHANTOM);
2060
2061 // JSR 292 classes
2062 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
2063 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
2064 resolve_wk_klasses_until(jsr292_group_start, scan, CHECK);
2065 resolve_wk_klasses_through(jsr292_group_end, scan, CHECK);
2066 WKID last = WKID_LIMIT;
2067 resolve_wk_klasses_until(last, scan, CHECK);
2068
2069 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
2070 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
2071 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
2072 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
2073 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
2074 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
2075 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
2076 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
2077 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
2078 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
2079
2080 #ifdef ASSERT
2081 if (UseSharedSpaces) {
2082 JVMTI_ONLY(assert(JvmtiExport::is_early_phase(),
2083 "All well known classes must be resolved in JVMTI early phase"));
2084 for (int i = FIRST_WKID; i < last; i++) {
2085 InstanceKlass* k = _well_known_klasses[i];
2086 assert(k->is_shared(), "must not be replaced by JVMTI class file load hook");
2087 }
2088 }
2089 #endif
2090 }
2091
2092 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
2093 // If so, returns the basic type it holds. If not, returns T_OBJECT.
2094 BasicType SystemDictionary::box_klass_type(Klass* k) {
2095 assert(k != NULL, "");
2096 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
2097 if (_box_klasses[i] == k)
2098 return (BasicType)i;
2099 }
2100 return T_OBJECT;
2101 }
2102
2103 // Constraints on class loaders. The details of the algorithm can be
2104 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
2105 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
2106 // that the dictionary needs to maintain a set of contraints that
2107 // must be satisfied by all classes in the dictionary.
2108 // if defining is true, then LinkageError if already in dictionary
2109 // if initiating loader, then ok if InstanceKlass matches existing entry
2110
2111 void SystemDictionary::check_constraints(unsigned int d_hash,
2112 InstanceKlass* k,
2113 Handle class_loader,
2114 bool defining,
2115 TRAPS) {
2116 ResourceMark rm(THREAD);
2117 stringStream ss;
2118 bool throwException = false;
2119
2120 {
2121 Symbol *name = k->name();
2122 ClassLoaderData *loader_data = class_loader_data(class_loader);
2123
2124 MutexLocker mu(THREAD, SystemDictionary_lock);
2125
2126 InstanceKlass* check = find_class(d_hash, name, loader_data->dictionary());
2127 if (check != NULL) {
2128 // If different InstanceKlass - duplicate class definition,
2129 // else - ok, class loaded by a different thread in parallel.
2130 // We should only have found it if it was done loading and ok to use.
2131 // The dictionary only holds instance classes, placeholders
2132 // also hold array classes.
2133
2134 assert(check->is_instance_klass(), "noninstance in systemdictionary");
2135 if ((defining == true) || (k != check)) {
2136 throwException = true;
2137 ss.print("loader %s", loader_data->loader_name_and_id());
2138 ss.print(" attempted duplicate %s definition for %s. (%s)",
2139 k->external_kind(), k->external_name(), k->class_in_module_of_loader(false, true));
2140 } else {
2141 return;
2142 }
2143 }
2144
2145 #ifdef ASSERT
2146 Symbol* ph_check = find_placeholder(name, loader_data);
2147 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2148 #endif
2149
2150 if (throwException == false) {
2151 if (constraints()->check_or_update(k, class_loader, name) == false) {
2152 throwException = true;
2153 ss.print("loader constraint violation: loader %s", loader_data->loader_name_and_id());
2154 ss.print(" wants to load %s %s.",
2155 k->external_kind(), k->external_name());
2156 Klass *existing_klass = constraints()->find_constrained_klass(name, class_loader);
2157 if (existing_klass != NULL && existing_klass->class_loader() != class_loader()) {
2158 ss.print(" A different %s with the same name was previously loaded by %s. (%s)",
2159 existing_klass->external_kind(),
2160 existing_klass->class_loader_data()->loader_name_and_id(),
2161 existing_klass->class_in_module_of_loader(false, true));
2162 } else {
2163 ss.print(" (%s)", k->class_in_module_of_loader(false, true));
2164 }
2165 }
2166 }
2167 }
2168
2169 // Throw error now if needed (cannot throw while holding
2170 // SystemDictionary_lock because of rank ordering)
2171 if (throwException == true) {
2172 THROW_MSG(vmSymbols::java_lang_LinkageError(), ss.as_string());
2173 }
2174 }
2175
2176 // Update class loader data dictionary - done after check_constraint and add_to_hierachy
2177 // have been called.
2178 void SystemDictionary::update_dictionary(unsigned int d_hash,
2179 int p_index, unsigned int p_hash,
2180 InstanceKlass* k,
2181 Handle class_loader,
2182 TRAPS) {
2183 // Compile_lock prevents systemDictionary updates during compilations
2184 assert_locked_or_safepoint(Compile_lock);
2185 Symbol* name = k->name();
2186 ClassLoaderData *loader_data = class_loader_data(class_loader);
2187
2188 {
2189 MutexLocker mu1(THREAD, SystemDictionary_lock);
2190
2191 // Make a new dictionary entry.
2192 Dictionary* dictionary = loader_data->dictionary();
2193 InstanceKlass* sd_check = find_class(d_hash, name, dictionary);
2194 if (sd_check == NULL) {
2195 dictionary->add_klass(d_hash, name, k);
2196 }
2197 #ifdef ASSERT
2198 sd_check = find_class(d_hash, name, dictionary);
2199 assert (sd_check != NULL, "should have entry in dictionary");
2200 // Note: there may be a placeholder entry: for circularity testing
2201 // or for parallel defines
2202 #endif
2203 SystemDictionary_lock->notify_all();
2204 }
2205 }
2206
2207
2208 // Try to find a class name using the loader constraints. The
2209 // loader constraints might know about a class that isn't fully loaded
2210 // yet and these will be ignored.
2211 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2212 Symbol* class_name, Handle class_loader, TRAPS) {
2213
2214 // First see if it has been loaded directly.
2215 // Force the protection domain to be null. (This removes protection checks.)
2216 Handle no_protection_domain;
2217 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2218 no_protection_domain, CHECK_NULL);
2219 if (klass != NULL)
2220 return klass;
2221
2222 // Now look to see if it has been loaded elsewhere, and is subject to
2223 // a loader constraint that would require this loader to return the
2224 // klass that is already loaded.
2225 if (Signature::is_array(class_name)) {
2226 // For array classes, their Klass*s are not kept in the
2227 // constraint table. The element Klass*s are.
2228 SignatureStream ss(class_name, false);
2229 int ndims = ss.skip_array_prefix(); // skip all '['s
2230 BasicType t = ss.type();
2231 if (t != T_OBJECT) {
2232 klass = Universe::typeArrayKlassObj(t);
2233 } else {
2234 MutexLocker mu(THREAD, SystemDictionary_lock);
2235 klass = constraints()->find_constrained_klass(ss.as_symbol(), class_loader);
2236 }
2237 // If element class already loaded, allocate array klass
2238 if (klass != NULL) {
2239 klass = klass->array_klass_or_null(ndims);
2240 }
2241 } else {
2242 MutexLocker mu(THREAD, SystemDictionary_lock);
2243 // Non-array classes are easy: simply check the constraint table.
2244 klass = constraints()->find_constrained_klass(class_name, class_loader);
2245 }
2246
2247 return klass;
2248 }
2249
2250
2251 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2252 Handle class_loader1,
2253 Handle class_loader2,
2254 Thread* THREAD) {
2255 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2256 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2257
2258 Symbol* constraint_name = NULL;
2259
2260 if (!Signature::is_array(class_name)) {
2261 constraint_name = class_name;
2262 } else {
2263 // For array classes, their Klass*s are not kept in the
2264 // constraint table. The element classes are.
2265 SignatureStream ss(class_name, false);
2266 ss.skip_array_prefix(); // skip all '['s
2267 if (!ss.has_envelope()) {
2268 return true; // primitive types always pass
2269 }
2270 constraint_name = ss.as_symbol();
2271 // Increment refcount to keep constraint_name alive after
2272 // SignatureStream is destructed. It will be decremented below
2273 // before returning.
2274 constraint_name->increment_refcount();
2275 }
2276
2277 Dictionary* dictionary1 = loader_data1->dictionary();
2278 unsigned int d_hash1 = dictionary1->compute_hash(constraint_name);
2279
2280 Dictionary* dictionary2 = loader_data2->dictionary();
2281 unsigned int d_hash2 = dictionary2->compute_hash(constraint_name);
2282
2283 {
2284 MutexLocker mu_s(THREAD, SystemDictionary_lock);
2285 InstanceKlass* klass1 = find_class(d_hash1, constraint_name, dictionary1);
2286 InstanceKlass* klass2 = find_class(d_hash2, constraint_name, dictionary2);
2287 bool result = constraints()->add_entry(constraint_name, klass1, class_loader1,
2288 klass2, class_loader2);
2289 if (Signature::is_array(class_name)) {
2290 constraint_name->decrement_refcount();
2291 }
2292 return result;
2293 }
2294 }
2295
2296 // Add entry to resolution error table to record the error when the first
2297 // attempt to resolve a reference to a class has failed.
2298 void SystemDictionary::add_resolution_error(const constantPoolHandle& pool, int which,
2299 Symbol* error, Symbol* message) {
2300 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2301 int index = resolution_errors()->hash_to_index(hash);
2302 {
2303 MutexLocker ml(Thread::current(), SystemDictionary_lock);
2304 resolution_errors()->add_entry(index, hash, pool, which, error, message);
2305 }
2306 }
2307
2308 // Delete a resolution error for RedefineClasses for a constant pool is going away
2309 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2310 resolution_errors()->delete_entry(pool);
2311 }
2312
2313 // Lookup resolution error table. Returns error if found, otherwise NULL.
2314 Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool, int which,
2315 Symbol** message) {
2316 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2317 int index = resolution_errors()->hash_to_index(hash);
2318 {
2319 MutexLocker ml(Thread::current(), SystemDictionary_lock);
2320 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2321 if (entry != NULL) {
2322 *message = entry->message();
2323 return entry->error();
2324 } else {
2325 return NULL;
2326 }
2327 }
2328 }
2329
2330
2331 // Signature constraints ensure that callers and callees agree about
2332 // the meaning of type names in their signatures. This routine is the
2333 // intake for constraints. It collects them from several places:
2334 //
2335 // * LinkResolver::resolve_method (if check_access is true) requires
2336 // that the resolving class (the caller) and the defining class of
2337 // the resolved method (the callee) agree on each type in the
2338 // method's signature.
2339 //
2340 // * LinkResolver::resolve_interface_method performs exactly the same
2341 // checks.
2342 //
2343 // * LinkResolver::resolve_field requires that the constant pool
2344 // attempting to link to a field agree with the field's defining
2345 // class about the type of the field signature.
2346 //
2347 // * klassVtable::initialize_vtable requires that, when a class
2348 // overrides a vtable entry allocated by a superclass, that the
2349 // overriding method (i.e., the callee) agree with the superclass
2350 // on each type in the method's signature.
2351 //
2352 // * klassItable::initialize_itable requires that, when a class fills
2353 // in its itables, for each non-abstract method installed in an
2354 // itable, the method (i.e., the callee) agree with the interface
2355 // on each type in the method's signature.
2356 //
2357 // All those methods have a boolean (check_access, checkconstraints)
2358 // which turns off the checks. This is used from specialized contexts
2359 // such as bootstrapping, dumping, and debugging.
2360 //
2361 // No direct constraint is placed between the class and its
2362 // supertypes. Constraints are only placed along linked relations
2363 // between callers and callees. When a method overrides or implements
2364 // an abstract method in a supertype (superclass or interface), the
2365 // constraints are placed as if the supertype were the caller to the
2366 // overriding method. (This works well, since callers to the
2367 // supertype have already established agreement between themselves and
2368 // the supertype.) As a result of all this, a class can disagree with
2369 // its supertype about the meaning of a type name, as long as that
2370 // class neither calls a relevant method of the supertype, nor is
2371 // called (perhaps via an override) from the supertype.
2372 //
2373 //
2374 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2375 //
2376 // Make sure all class components (including arrays) in the given
2377 // signature will be resolved to the same class in both loaders.
2378 // Returns the name of the type that failed a loader constraint check, or
2379 // NULL if no constraint failed. No exception except OOME is thrown.
2380 // Arrays are not added to the loader constraint table, their elements are.
2381 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2382 Handle loader1, Handle loader2,
2383 bool is_method, TRAPS) {
2384 // Nothing to do if loaders are the same.
2385 if (loader1() == loader2()) {
2386 return NULL;
2387 }
2388
2389 for (SignatureStream ss(signature, is_method); !ss.is_done(); ss.next()) {
2390 if (ss.is_reference()) {
2391 Symbol* sig = ss.as_symbol();
2392 // Note: In the future, if template-like types can take
2393 // arguments, we will want to recognize them and dig out class
2394 // names hiding inside the argument lists.
2395 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2396 return sig;
2397 }
2398 }
2399 }
2400 return NULL;
2401 }
2402
2403
2404 Method* SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2405 Symbol* signature,
2406 TRAPS) {
2407 methodHandle empty;
2408 assert(MethodHandles::is_signature_polymorphic(iid) &&
2409 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2410 iid != vmIntrinsics::_invokeGeneric,
2411 "must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid));
2412
2413 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2414 int index = invoke_method_table()->hash_to_index(hash);
2415 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2416 methodHandle m;
2417 if (spe == NULL || spe->method() == NULL) {
2418 spe = NULL;
2419 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2420 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_NULL);
2421 if (!Arguments::is_interpreter_only()) {
2422 // Generate a compiled form of the MH intrinsic.
2423 AdapterHandlerLibrary::create_native_wrapper(m);
2424 // Check if have the compiled code.
2425 if (!m->has_compiled_code()) {
2426 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(),
2427 "Out of space in CodeCache for method handle intrinsic");
2428 }
2429 }
2430 // Now grab the lock. We might have to throw away the new method,
2431 // if a racing thread has managed to install one at the same time.
2432 {
2433 MutexLocker ml(THREAD, SystemDictionary_lock);
2434 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2435 if (spe == NULL)
2436 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2437 if (spe->method() == NULL)
2438 spe->set_method(m());
2439 }
2440 }
2441
2442 assert(spe != NULL && spe->method() != NULL, "");
2443 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2444 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2445 "MH intrinsic invariant");
2446 return spe->method();
2447 }
2448
2449 // Helper for unpacking the return value from linkMethod and linkCallSite.
2450 static Method* unpack_method_and_appendix(Handle mname,
2451 Klass* accessing_klass,
2452 objArrayHandle appendix_box,
2453 Handle* appendix_result,
2454 TRAPS) {
2455 if (mname.not_null()) {
2456 Method* m = java_lang_invoke_MemberName::vmtarget(mname());
2457 if (m != NULL) {
2458 oop appendix = appendix_box->obj_at(0);
2459 if (TraceMethodHandles) {
2460 #ifndef PRODUCT
2461 ttyLocker ttyl;
2462 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2463 m->print();
2464 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2465 tty->cr();
2466 #endif //PRODUCT
2467 }
2468 (*appendix_result) = Handle(THREAD, appendix);
2469 // the target is stored in the cpCache and if a reference to this
2470 // MemberName is dropped we need a way to make sure the
2471 // class_loader containing this method is kept alive.
2472 methodHandle mh(THREAD, m); // record_dependency can safepoint.
2473 ClassLoaderData* this_key = accessing_klass->class_loader_data();
2474 this_key->record_dependency(m->method_holder());
2475 return mh();
2476 }
2477 }
2478 THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives");
2479 }
2480
2481 Method* SystemDictionary::find_method_handle_invoker(Klass* klass,
2482 Symbol* name,
2483 Symbol* signature,
2484 Klass* accessing_klass,
2485 Handle *appendix_result,
2486 TRAPS) {
2487 assert(THREAD->can_call_java() ,"");
2488 Handle method_type =
2489 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_NULL);
2490
2491 int ref_kind = JVM_REF_invokeVirtual;
2492 oop name_oop = StringTable::intern(name, CHECK_NULL);
2493 Handle name_str (THREAD, name_oop);
2494 objArrayHandle appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK_NULL);
2495 assert(appendix_box->obj_at(0) == NULL, "");
2496
2497 // This should not happen. JDK code should take care of that.
2498 if (accessing_klass == NULL || method_type.is_null()) {
2499 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "bad invokehandle");
2500 }
2501
2502 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2503 JavaCallArguments args;
2504 args.push_oop(Handle(THREAD, accessing_klass->java_mirror()));
2505 args.push_int(ref_kind);
2506 args.push_oop(Handle(THREAD, klass->java_mirror()));
2507 args.push_oop(name_str);
2508 args.push_oop(method_type);
2509 args.push_oop(appendix_box);
2510 JavaValue result(T_OBJECT);
2511 JavaCalls::call_static(&result,
2512 SystemDictionary::MethodHandleNatives_klass(),
2513 vmSymbols::linkMethod_name(),
2514 vmSymbols::linkMethod_signature(),
2515 &args, CHECK_NULL);
2516 Handle mname(THREAD, (oop) result.get_jobject());
2517 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2518 }
2519
2520 // Decide if we can globally cache a lookup of this class, to be returned to any client that asks.
2521 // We must ensure that all class loaders everywhere will reach this class, for any client.
2522 // This is a safe bet for public classes in java.lang, such as Object and String.
2523 // We also include public classes in java.lang.invoke, because they appear frequently in system-level method types.
2524 // Out of an abundance of caution, we do not include any other classes, not even for packages like java.util.
2525 static bool is_always_visible_class(oop mirror) {
2526 Klass* klass = java_lang_Class::as_Klass(mirror);
2527 if (klass->is_objArray_klass()) {
2528 klass = ObjArrayKlass::cast(klass)->bottom_klass(); // check element type
2529 }
2530 if (klass->is_typeArray_klass()) {
2531 return true; // primitive array
2532 }
2533 assert(klass->is_instance_klass(), "%s", klass->external_name());
2534 return klass->is_public() &&
2535 (InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::Object_klass()) || // java.lang
2536 InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::MethodHandle_klass())); // java.lang.invoke
2537 }
2538
2539 // Find or construct the Java mirror (java.lang.Class instance) for
2540 // the given field type signature, as interpreted relative to the
2541 // given class loader. Handles primitives, void, references, arrays,
2542 // and all other reflectable types, except method types.
2543 // N.B. Code in reflection should use this entry point.
2544 Handle SystemDictionary::find_java_mirror_for_type(Symbol* signature,
2545 Klass* accessing_klass,
2546 Handle class_loader,
2547 Handle protection_domain,
2548 SignatureStream::FailureMode failure_mode,
2549 TRAPS) {
2550 assert(accessing_klass == NULL || (class_loader.is_null() && protection_domain.is_null()),
2551 "one or the other, or perhaps neither");
2552
2553 // What we have here must be a valid field descriptor,
2554 // and all valid field descriptors are supported.
2555 // Produce the same java.lang.Class that reflection reports.
2556 if (accessing_klass != NULL) {
2557 class_loader = Handle(THREAD, accessing_klass->class_loader());
2558 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2559 }
2560 ResolvingSignatureStream ss(signature, class_loader, protection_domain, false);
2561 oop mirror_oop = ss.as_java_mirror(failure_mode, CHECK_NH);
2562 if (mirror_oop == NULL) {
2563 return Handle(); // report failure this way
2564 }
2565 Handle mirror(THREAD, mirror_oop);
2566
2567 if (accessing_klass != NULL) {
2568 // Check accessibility, emulating ConstantPool::verify_constant_pool_resolve.
2569 Klass* sel_klass = java_lang_Class::as_Klass(mirror());
2570 if (sel_klass != NULL) {
2571 bool fold_type_to_class = true;
2572 LinkResolver::check_klass_accessability(accessing_klass, sel_klass,
2573 fold_type_to_class, CHECK_NH);
2574 }
2575 }
2576 return mirror;
2577 }
2578
2579
2580 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2581 // signature, as interpreted relative to the given class loader.
2582 // Because of class loader constraints, all method handle usage must be
2583 // consistent with this loader.
2584 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2585 Klass* accessing_klass,
2586 TRAPS) {
2587 Handle empty;
2588 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2589 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2590 int index = invoke_method_table()->hash_to_index(hash);
2591 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2592 if (spe != NULL && spe->method_type() != NULL) {
2593 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2594 return Handle(THREAD, spe->method_type());
2595 } else if (!THREAD->can_call_java()) {
2596 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2597 return Handle(); // do not attempt from within compiler, unless it was cached
2598 }
2599
2600 Handle class_loader, protection_domain;
2601 if (accessing_klass != NULL) {
2602 class_loader = Handle(THREAD, accessing_klass->class_loader());
2603 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2604 }
2605 bool can_be_cached = true;
2606 int npts = ArgumentCount(signature).size();
2607 objArrayHandle pts = oopFactory::new_objArray_handle(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2608 int arg = 0;
2609 Handle rt; // the return type from the signature
2610 ResourceMark rm(THREAD);
2611 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2612 oop mirror = NULL;
2613 if (can_be_cached) {
2614 // Use neutral class loader to lookup candidate classes to be placed in the cache.
2615 mirror = ss.as_java_mirror(Handle(), Handle(),
2616 SignatureStream::ReturnNull, CHECK_(empty));
2617 if (mirror == NULL || (ss.is_reference() && !is_always_visible_class(mirror))) {
2618 // Fall back to accessing_klass context.
2619 can_be_cached = false;
2620 }
2621 }
2622 if (!can_be_cached) {
2623 // Resolve, throwing a real error if it doesn't work.
2624 mirror = ss.as_java_mirror(class_loader, protection_domain,
2625 SignatureStream::NCDFError, CHECK_(empty));
2626 }
2627 assert(mirror != NULL, "%s", ss.as_symbol()->as_C_string());
2628 if (ss.at_return_type())
2629 rt = Handle(THREAD, mirror);
2630 else
2631 pts->obj_at_put(arg++, mirror);
2632
2633 // Check accessibility.
2634 if (!java_lang_Class::is_primitive(mirror) && accessing_klass != NULL) {
2635 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2636 mirror = NULL; // safety
2637 // Emulate ConstantPool::verify_constant_pool_resolve.
2638 bool fold_type_to_class = true;
2639 LinkResolver::check_klass_accessability(accessing_klass, sel_klass,
2640 fold_type_to_class, CHECK_(empty));
2641 }
2642 }
2643 assert(arg == npts, "");
2644
2645 // call java.lang.invoke.MethodHandleNatives::findMethodHandleType(Class rt, Class[] pts) -> MethodType
2646 JavaCallArguments args(Handle(THREAD, rt()));
2647 args.push_oop(pts);
2648 JavaValue result(T_OBJECT);
2649 JavaCalls::call_static(&result,
2650 SystemDictionary::MethodHandleNatives_klass(),
2651 vmSymbols::findMethodHandleType_name(),
2652 vmSymbols::findMethodHandleType_signature(),
2653 &args, CHECK_(empty));
2654 Handle method_type(THREAD, (oop) result.get_jobject());
2655
2656 if (can_be_cached) {
2657 // We can cache this MethodType inside the JVM.
2658 MutexLocker ml(THREAD, SystemDictionary_lock);
2659 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2660 if (spe == NULL)
2661 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2662 if (spe->method_type() == NULL) {
2663 spe->set_method_type(method_type());
2664 }
2665 }
2666
2667 // report back to the caller with the MethodType
2668 return method_type;
2669 }
2670
2671 Handle SystemDictionary::find_field_handle_type(Symbol* signature,
2672 Klass* accessing_klass,
2673 TRAPS) {
2674 Handle empty;
2675 ResourceMark rm(THREAD);
2676 SignatureStream ss(signature, /*is_method=*/ false);
2677 if (!ss.is_done()) {
2678 Handle class_loader, protection_domain;
2679 if (accessing_klass != NULL) {
2680 class_loader = Handle(THREAD, accessing_klass->class_loader());
2681 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2682 }
2683 oop mirror = ss.as_java_mirror(class_loader, protection_domain, SignatureStream::NCDFError, CHECK_(empty));
2684 ss.next();
2685 if (ss.is_done()) {
2686 return Handle(THREAD, mirror);
2687 }
2688 }
2689 return empty;
2690 }
2691
2692 // Ask Java code to find or construct a method handle constant.
2693 Handle SystemDictionary::link_method_handle_constant(Klass* caller,
2694 int ref_kind, //e.g., JVM_REF_invokeVirtual
2695 Klass* callee,
2696 Symbol* name,
2697 Symbol* signature,
2698 TRAPS) {
2699 Handle empty;
2700 if (caller == NULL) {
2701 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2702 }
2703 Handle name_str = java_lang_String::create_from_symbol(name, CHECK_(empty));
2704 Handle signature_str = java_lang_String::create_from_symbol(signature, CHECK_(empty));
2705
2706 // Put symbolic info from the MH constant into freshly created MemberName and resolve it.
2707 Handle mname = MemberName_klass()->allocate_instance_handle(CHECK_(empty));
2708 java_lang_invoke_MemberName::set_clazz(mname(), callee->java_mirror());
2709 java_lang_invoke_MemberName::set_name (mname(), name_str());
2710 java_lang_invoke_MemberName::set_type (mname(), signature_str());
2711 java_lang_invoke_MemberName::set_flags(mname(), MethodHandles::ref_kind_to_flags(ref_kind));
2712
2713 if (ref_kind == JVM_REF_invokeVirtual &&
2714 MethodHandles::is_signature_polymorphic_public_name(callee, name)) {
2715 // Skip resolution for public signature polymorphic methods such as
2716 // j.l.i.MethodHandle.invoke()/invokeExact() and those on VarHandle
2717 // They require appendix argument which MemberName resolution doesn't handle.
2718 // There's special logic on JDK side to handle them
2719 // (see MethodHandles.linkMethodHandleConstant() and MethodHandles.findVirtualForMH()).
2720 } else {
2721 MethodHandles::resolve_MemberName(mname, caller, /*speculative_resolve*/false, CHECK_(empty));
2722 }
2723
2724 // After method/field resolution succeeded, it's safe to resolve MH signature as well.
2725 Handle type = MethodHandles::resolve_MemberName_type(mname, caller, CHECK_(empty));
2726
2727 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2728 JavaCallArguments args;
2729 args.push_oop(Handle(THREAD, caller->java_mirror())); // the referring class
2730 args.push_int(ref_kind);
2731 args.push_oop(Handle(THREAD, callee->java_mirror())); // the target class
2732 args.push_oop(name_str);
2733 args.push_oop(type);
2734 JavaValue result(T_OBJECT);
2735 JavaCalls::call_static(&result,
2736 SystemDictionary::MethodHandleNatives_klass(),
2737 vmSymbols::linkMethodHandleConstant_name(),
2738 vmSymbols::linkMethodHandleConstant_signature(),
2739 &args, CHECK_(empty));
2740 return Handle(THREAD, (oop) result.get_jobject());
2741 }
2742
2743 // Ask Java to run a bootstrap method, in order to create a dynamic call site
2744 // while linking an invokedynamic op, or compute a constant for Dynamic_info CP entry
2745 // with linkage results being stored back into the bootstrap specifier.
2746 void SystemDictionary::invoke_bootstrap_method(BootstrapInfo& bootstrap_specifier, TRAPS) {
2747 // Resolve the bootstrap specifier, its name, type, and static arguments
2748 bootstrap_specifier.resolve_bsm(CHECK);
2749
2750 // This should not happen. JDK code should take care of that.
2751 if (bootstrap_specifier.caller() == NULL || bootstrap_specifier.type_arg().is_null()) {
2752 THROW_MSG(vmSymbols::java_lang_InternalError(), "Invalid bootstrap method invocation with no caller or type argument");
2753 }
2754
2755 bool is_indy = bootstrap_specifier.is_method_call();
2756 objArrayHandle appendix_box;
2757 if (is_indy) {
2758 // Some method calls may require an appendix argument. Arrange to receive it.
2759 appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK);
2760 assert(appendix_box->obj_at(0) == NULL, "");
2761 }
2762
2763 // call condy: java.lang.invoke.MethodHandleNatives::linkDynamicConstant(caller, condy_index, bsm, type, info)
2764 // indy: java.lang.invoke.MethodHandleNatives::linkCallSite(caller, indy_index, bsm, name, mtype, info, &appendix)
2765 JavaCallArguments args;
2766 args.push_oop(Handle(THREAD, bootstrap_specifier.caller_mirror()));
2767 args.push_int(bootstrap_specifier.bss_index());
2768 args.push_oop(bootstrap_specifier.bsm());
2769 args.push_oop(bootstrap_specifier.name_arg());
2770 args.push_oop(bootstrap_specifier.type_arg());
2771 args.push_oop(bootstrap_specifier.arg_values());
2772 if (is_indy) {
2773 args.push_oop(appendix_box);
2774 }
2775 JavaValue result(T_OBJECT);
2776 JavaCalls::call_static(&result,
2777 SystemDictionary::MethodHandleNatives_klass(),
2778 is_indy ? vmSymbols::linkCallSite_name() : vmSymbols::linkDynamicConstant_name(),
2779 is_indy ? vmSymbols::linkCallSite_signature() : vmSymbols::linkDynamicConstant_signature(),
2780 &args, CHECK);
2781
2782 Handle value(THREAD, (oop) result.get_jobject());
2783 if (is_indy) {
2784 Handle appendix;
2785 Method* method = unpack_method_and_appendix(value,
2786 bootstrap_specifier.caller(),
2787 appendix_box,
2788 &appendix, CHECK);
2789 methodHandle mh(THREAD, method);
2790 bootstrap_specifier.set_resolved_method(mh, appendix);
2791 } else {
2792 bootstrap_specifier.set_resolved_value(value);
2793 }
2794
2795 // sanity check
2796 assert(bootstrap_specifier.is_resolved() ||
2797 (bootstrap_specifier.is_method_call() &&
2798 bootstrap_specifier.resolved_method().not_null()), "bootstrap method call failed");
2799 }
2800
2801 // Protection domain cache table handling
2802
2803 ProtectionDomainCacheEntry* SystemDictionary::cache_get(Handle protection_domain) {
2804 return _pd_cache_table->get(protection_domain);
2805 }
2806
2807 // ----------------------------------------------------------------------------
2808
2809 void SystemDictionary::print_on(outputStream *st) {
2810 CDS_ONLY(SystemDictionaryShared::print_on(st));
2811 GCMutexLocker mu(SystemDictionary_lock);
2812
2813 ClassLoaderDataGraph::print_dictionary(st);
2814
2815 // Placeholders
2816 placeholders()->print_on(st);
2817 st->cr();
2818
2819 // loader constraints - print under SD_lock
2820 constraints()->print_on(st);
2821 st->cr();
2822
2823 _pd_cache_table->print_on(st);
2824 st->cr();
2825 }
2826
2827 void SystemDictionary::print() { print_on(tty); }
2828
2829 void SystemDictionary::verify() {
2830 guarantee(constraints() != NULL,
2831 "Verify of loader constraints failed");
2832 guarantee(placeholders()->number_of_entries() >= 0,
2833 "Verify of placeholders failed");
2834
2835 GCMutexLocker mu(SystemDictionary_lock);
2836
2837 // Verify dictionary
2838 ClassLoaderDataGraph::verify_dictionary();
2839
2840 placeholders()->verify();
2841
2842 // Verify constraint table
2843 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2844 constraints()->verify(placeholders());
2845
2846 _pd_cache_table->verify();
2847 }
2848
2849 void SystemDictionary::dump(outputStream *st, bool verbose) {
2850 assert_locked_or_safepoint(SystemDictionary_lock);
2851 if (verbose) {
2852 print_on(st);
2853 } else {
2854 CDS_ONLY(SystemDictionaryShared::print_table_statistics(st));
2855 ClassLoaderDataGraph::print_table_statistics(st);
2856 placeholders()->print_table_statistics(st, "Placeholder Table");
2857 constraints()->print_table_statistics(st, "LoaderConstraints Table");
2858 pd_cache_table()->print_table_statistics(st, "ProtectionDomainCache Table");
2859 }
2860 }
2861
2862 TableStatistics SystemDictionary::placeholders_statistics() {
2863 MutexLocker ml(SystemDictionary_lock);
2864 return placeholders()->statistics_calculate();
2865 }
2866
2867 TableStatistics SystemDictionary::loader_constraints_statistics() {
2868 MutexLocker ml(SystemDictionary_lock);
2869 return constraints()->statistics_calculate();
2870 }
2871
2872 TableStatistics SystemDictionary::protection_domain_cache_statistics() {
2873 MutexLocker ml(SystemDictionary_lock);
2874 return pd_cache_table()->statistics_calculate();
2875 }
2876
2877 // Utility for dumping dictionaries.
2878 SystemDictionaryDCmd::SystemDictionaryDCmd(outputStream* output, bool heap) :
2879 DCmdWithParser(output, heap),
2880 _verbose("-verbose", "Dump the content of each dictionary entry for all class loaders",
2881 "BOOLEAN", false, "false") {
2882 _dcmdparser.add_dcmd_option(&_verbose);
2883 }
2884
2885 void SystemDictionaryDCmd::execute(DCmdSource source, TRAPS) {
2886 VM_DumpHashtable dumper(output(), VM_DumpHashtable::DumpSysDict,
2887 _verbose.value());
2888 VMThread::execute(&dumper);
2889 }
2890
2891 int SystemDictionaryDCmd::num_arguments() {
2892 ResourceMark rm;
2893 SystemDictionaryDCmd* dcmd = new SystemDictionaryDCmd(NULL, false);
2894 if (dcmd != NULL) {
2895 DCmdMark mark(dcmd);
2896 return dcmd->_dcmdparser.num_arguments();
2897 } else {
2898 return 0;
2899 }
2900 }