rev 58452 : imported patch pkg_name_from_class
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() == 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 TRAPS) {
1161 InstanceKlass* ik = SystemDictionaryShared::find_builtin_class(class_name);
1162 if (ik != NULL && ik->is_shared_boot_class()) {
1163 return load_shared_class(ik, Handle(), Handle(), NULL, THREAD);
1164 }
1165 return NULL;
1166 }
1167
1168 // Check if a shared class can be loaded by the specific classloader:
1169 //
1170 // NULL classloader:
1171 // - Module class from "modules" jimage. ModuleEntry must be defined in the classloader.
1172 // - Class from -Xbootclasspath/a. The class has no defined PackageEntry, or must
1173 // be defined in an unnamed module.
1174 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
1175 InstanceKlass* ik,
1176 Handle class_loader, TRAPS) {
1177 assert(!ModuleEntryTable::javabase_moduleEntry()->is_patched(),
1178 "Cannot use sharing if java.base is patched");
1179 ResourceMark rm(THREAD);
1180 int path_index = ik->shared_classpath_index();
1181 ClassLoaderData* loader_data = class_loader_data(class_loader);
1182 if (path_index < 0) {
1183 // path_index < 0 indicates that the class is intended for a custom loader
1184 // and should not be loaded by boot/platform/app loaders
1185 if (loader_data->is_builtin_class_loader_data()) {
1186 return false;
1187 } else {
1188 return true;
1189 }
1190 }
1191 SharedClassPathEntry* ent =
1192 (SharedClassPathEntry*)FileMapInfo::shared_path(path_index);
1193 if (!Universe::is_module_initialized()) {
1194 assert(ent != NULL && ent->is_modules_image(),
1195 "Loading non-bootstrap classes before the module system is initialized");
1196 assert(class_loader.is_null(), "sanity");
1197 return true;
1198 }
1199 // Get the pkg_entry from the classloader
1200 TempNewSymbol pkg_name = NULL;
1201 PackageEntry* pkg_entry = NULL;
1202 ModuleEntry* mod_entry = NULL;
1203 pkg_name = InstanceKlass::package_from_name(class_name, CHECK_false);
1204 if (pkg_name != NULL) {
1205 if (loader_data != NULL) {
1206 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1207 }
1208 if (pkg_entry != NULL) {
1209 mod_entry = pkg_entry->module();
1210 }
1211 }
1212
1213 // If the archived class is from a module that has been patched at runtime,
1214 // the class cannot be loaded from the archive.
1215 if (mod_entry != NULL && mod_entry->is_patched()) {
1216 return false;
1217 }
1218
1219 if (class_loader.is_null()) {
1220 assert(ent != NULL, "Shared class for NULL classloader must have valid SharedClassPathEntry");
1221 // The NULL classloader can load archived class originated from the
1222 // "modules" jimage and the -Xbootclasspath/a. For class from the
1223 // "modules" jimage, the PackageEntry/ModuleEntry must be defined
1224 // by the NULL classloader.
1225 if (mod_entry != NULL) {
1226 // PackageEntry/ModuleEntry is found in the classloader. Check if the
1227 // ModuleEntry's location agrees with the archived class' origination.
1228 if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
1229 return true; // Module class from the "module" jimage
1230 }
1231 }
1232
1233 // If the archived class is not from the "module" jimage, the class can be
1234 // loaded by the NULL classloader if
1235 //
1236 // 1. the class is from the unamed package
1237 // 2. or, the class is not from a module defined in the NULL classloader
1238 // 3. or, the class is from an unamed module
1239 if (!ent->is_modules_image() && ik->is_shared_boot_class()) {
1240 // the class is from the -Xbootclasspath/a
1241 if (pkg_name == NULL ||
1242 pkg_entry == NULL ||
1243 pkg_entry->in_unnamed_module()) {
1244 assert(mod_entry == NULL ||
1245 mod_entry == loader_data->unnamed_module(),
1246 "the unnamed module is not defined in the classloader");
1247 return true;
1248 }
1249 }
1250 return false;
1251 } else {
1252 bool res = SystemDictionaryShared::is_shared_class_visible_for_classloader(
1253 ik, class_loader, pkg_name, pkg_entry, mod_entry, CHECK_(false));
1254 return res;
1255 }
1256 }
1257
1258 bool SystemDictionary::check_shared_class_super_type(InstanceKlass* child, InstanceKlass* super_type,
1259 Handle class_loader, Handle protection_domain,
1260 bool is_superclass, TRAPS) {
1261 assert(super_type->is_shared(), "must be");
1262
1263 Klass *found = resolve_super_or_fail(child->name(), super_type->name(),
1264 class_loader, protection_domain, is_superclass, CHECK_0);
1265 if (found == super_type) {
1266 return true;
1267 } else {
1268 // The dynamically resolved super type is not the same as the one we used during dump time,
1269 // so we cannot use the child class.
1270 return false;
1271 }
1272 }
1273
1274 bool SystemDictionary::check_shared_class_super_types(InstanceKlass* ik, Handle class_loader,
1275 Handle protection_domain, TRAPS) {
1276 // Check the superclass and interfaces. They must be the same
1277 // as in dump time, because the layout of <ik> depends on
1278 // the specific layout of ik->super() and ik->local_interfaces().
1279 //
1280 // If unexpected superclass or interfaces are found, we cannot
1281 // load <ik> from the shared archive.
1282
1283 if (ik->super() != NULL &&
1284 !check_shared_class_super_type(ik, InstanceKlass::cast(ik->super()),
1285 class_loader, protection_domain, true, THREAD)) {
1286 return false;
1287 }
1288
1289 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
1290 int num_interfaces = interfaces->length();
1291 for (int index = 0; index < num_interfaces; index++) {
1292 if (!check_shared_class_super_type(ik, interfaces->at(index), class_loader, protection_domain, false, THREAD)) {
1293 return false;
1294 }
1295 }
1296
1297 return true;
1298 }
1299
1300 InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
1301 Handle class_loader,
1302 Handle protection_domain,
1303 const ClassFileStream *cfs,
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, 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, 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 ResourceMark rm(THREAD);
1361 ClassLoader::add_package(ik->name()->as_C_string(), path_index, THREAD);
1362 }
1363
1364 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1365 // Only dump the classes that can be stored into CDS archive
1366 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1367 ResourceMark rm(THREAD);
1368 classlist_file->print_cr("%s", ik->name()->as_C_string());
1369 classlist_file->flush();
1370 }
1371 }
1372
1373 // notify a class loaded from shared object
1374 ClassLoadingService::notify_class_loaded(ik, true /* shared class */);
1375
1376 ik->set_has_passed_fingerprint_check(false);
1377 if (UseAOT && ik->supers_have_passed_fingerprint_checks()) {
1378 uint64_t aot_fp = AOTLoader::get_saved_fingerprint(ik);
1379 uint64_t cds_fp = ik->get_stored_fingerprint();
1380 if (aot_fp != 0 && aot_fp == cds_fp) {
1381 // This class matches with a class saved in an AOT library
1382 ik->set_has_passed_fingerprint_check(true);
1383 } else {
1384 if (log_is_enabled(Info, class, fingerprint)) {
1385 ResourceMark rm(THREAD);
1386 log_info(class, fingerprint)("%s : expected = " PTR64_FORMAT " actual = " PTR64_FORMAT, ik->external_name(), aot_fp, cds_fp);
1387 }
1388 }
1389 }
1390 }
1391
1392 void SystemDictionary::quick_resolve(InstanceKlass* klass, ClassLoaderData* loader_data, Handle domain, TRAPS) {
1393 assert(!Universe::is_fully_initialized(), "We can make short cuts only during VM initialization");
1394 assert(klass->is_shared(), "Must be shared class");
1395 if (klass->class_loader_data() != NULL) {
1396 return;
1397 }
1398
1399 // add super and interfaces first
1400 Klass* super = klass->super();
1401 if (super != NULL && super->class_loader_data() == NULL) {
1402 assert(super->is_instance_klass(), "Super should be instance klass");
1403 quick_resolve(InstanceKlass::cast(super), loader_data, domain, CHECK);
1404 }
1405
1406 Array<InstanceKlass*>* ifs = klass->local_interfaces();
1407 for (int i = 0; i < ifs->length(); i++) {
1408 InstanceKlass* ik = ifs->at(i);
1409 if (ik->class_loader_data() == NULL) {
1410 quick_resolve(ik, loader_data, domain, CHECK);
1411 }
1412 }
1413
1414 klass->restore_unshareable_info(loader_data, domain, THREAD);
1415 load_shared_class_misc(klass, loader_data, CHECK);
1416 Dictionary* dictionary = loader_data->dictionary();
1417 unsigned int hash = dictionary->compute_hash(klass->name());
1418 dictionary->add_klass(hash, klass->name(), klass);
1419 add_to_hierarchy(klass, CHECK);
1420 assert(klass->is_loaded(), "Must be in at least loaded state");
1421 }
1422 #endif // INCLUDE_CDS
1423
1424 InstanceKlass* SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1425
1426 if (class_loader.is_null()) {
1427 ResourceMark rm(THREAD);
1428 PackageEntry* pkg_entry = NULL;
1429 bool search_only_bootloader_append = false;
1430 ClassLoaderData *loader_data = class_loader_data(class_loader);
1431
1432 // Find the package in the boot loader's package entry table.
1433 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK_NULL);
1434 if (pkg_name != NULL) {
1435 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1436 }
1437
1438 // Prior to attempting to load the class, enforce the boot loader's
1439 // visibility boundaries.
1440 if (!Universe::is_module_initialized()) {
1441 // During bootstrapping, prior to module initialization, any
1442 // class attempting to be loaded must be checked against the
1443 // java.base packages in the boot loader's PackageEntryTable.
1444 // No class outside of java.base is allowed to be loaded during
1445 // this bootstrapping window.
1446 if (pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1447 // Class is either in the unnamed package or in
1448 // a named package within the unnamed module. Either
1449 // case is outside of java.base, do not attempt to
1450 // load the class post java.base definition. If
1451 // java.base has not been defined, let the class load
1452 // and its package will be checked later by
1453 // ModuleEntryTable::verify_javabase_packages.
1454 if (ModuleEntryTable::javabase_defined()) {
1455 return NULL;
1456 }
1457 } else {
1458 // Check that the class' package is defined within java.base.
1459 ModuleEntry* mod_entry = pkg_entry->module();
1460 Symbol* mod_entry_name = mod_entry->name();
1461 if (mod_entry_name->fast_compare(vmSymbols::java_base()) != 0) {
1462 return NULL;
1463 }
1464 }
1465 } else {
1466 // After the module system has been initialized, check if the class'
1467 // package is in a module defined to the boot loader.
1468 if (pkg_name == NULL || pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1469 // Class is either in the unnamed package, in a named package
1470 // within a module not defined to the boot loader or in a
1471 // a named package within the unnamed module. In all cases,
1472 // limit visibility to search for the class only in the boot
1473 // loader's append path.
1474 if (!ClassLoader::has_bootclasspath_append()) {
1475 // If there is no bootclasspath append entry, no need to continue
1476 // searching.
1477 return NULL;
1478 }
1479 search_only_bootloader_append = true;
1480 }
1481 }
1482
1483 // Prior to bootstrapping's module initialization, never load a class outside
1484 // of the boot loader's module path
1485 assert(Universe::is_module_initialized() ||
1486 !search_only_bootloader_append,
1487 "Attempt to load a class outside of boot loader's module path");
1488
1489 // Search for classes in the CDS archive.
1490 InstanceKlass* k = NULL;
1491 {
1492 #if INCLUDE_CDS
1493 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1494 k = load_shared_boot_class(class_name, THREAD);
1495 #endif
1496 }
1497
1498 if (k == NULL) {
1499 // Use VM class loader
1500 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1501 k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_NULL);
1502 }
1503
1504 // find_or_define_instance_class may return a different InstanceKlass
1505 if (k != NULL) {
1506 InstanceKlass* defined_k =
1507 find_or_define_instance_class(class_name, class_loader, k, THREAD);
1508 if (!HAS_PENDING_EXCEPTION && defined_k != k) {
1509 // If a parallel capable class loader already defined this class, register 'k' for cleanup.
1510 assert(defined_k != NULL, "Should have a klass if there's no exception");
1511 loader_data->add_to_deallocate_list(k);
1512 k = defined_k;
1513 } else if (HAS_PENDING_EXCEPTION) {
1514 loader_data->add_to_deallocate_list(k);
1515 return NULL;
1516 }
1517 }
1518 return k;
1519 } else {
1520 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1521 ResourceMark rm(THREAD);
1522
1523 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1524 JavaThread* jt = (JavaThread*) THREAD;
1525
1526 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1527 ClassLoader::perf_app_classload_selftime(),
1528 ClassLoader::perf_app_classload_count(),
1529 jt->get_thread_stat()->perf_recursion_counts_addr(),
1530 jt->get_thread_stat()->perf_timers_addr(),
1531 PerfClassTraceTime::CLASS_LOAD);
1532
1533 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_NULL);
1534 // Translate to external class name format, i.e., convert '/' chars to '.'
1535 Handle string = java_lang_String::externalize_classname(s, CHECK_NULL);
1536
1537 JavaValue result(T_OBJECT);
1538
1539 InstanceKlass* spec_klass = SystemDictionary::ClassLoader_klass();
1540
1541 // Call public unsynchronized loadClass(String) directly for all class loaders.
1542 // For parallelCapable class loaders, JDK >=7, loadClass(String, boolean) will
1543 // acquire a class-name based lock rather than the class loader object lock.
1544 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean).
1545 JavaCalls::call_virtual(&result,
1546 class_loader,
1547 spec_klass,
1548 vmSymbols::loadClass_name(),
1549 vmSymbols::string_class_signature(),
1550 string,
1551 CHECK_NULL);
1552
1553 assert(result.get_type() == T_OBJECT, "just checking");
1554 oop obj = (oop) result.get_jobject();
1555
1556 // Primitive classes return null since forName() can not be
1557 // used to obtain any of the Class objects representing primitives or void
1558 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1559 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(obj));
1560 // For user defined Java class loaders, check that the name returned is
1561 // the same as that requested. This check is done for the bootstrap
1562 // loader when parsing the class file.
1563 if (class_name == k->name()) {
1564 return k;
1565 }
1566 }
1567 // Class is not found or has the wrong name, return NULL
1568 return NULL;
1569 }
1570 }
1571
1572 static void post_class_define_event(InstanceKlass* k, const ClassLoaderData* def_cld) {
1573 EventClassDefine event;
1574 if (event.should_commit()) {
1575 event.set_definedClass(k);
1576 event.set_definingClassLoader(def_cld);
1577 event.commit();
1578 }
1579 }
1580
1581 void SystemDictionary::define_instance_class(InstanceKlass* k, TRAPS) {
1582
1583 HandleMark hm(THREAD);
1584 ClassLoaderData* loader_data = k->class_loader_data();
1585 Handle class_loader_h(THREAD, loader_data->class_loader());
1586
1587 // for bootstrap and other parallel classloaders don't acquire lock,
1588 // use placeholder token
1589 // If a parallelCapable class loader calls define_instance_class instead of
1590 // find_or_define_instance_class to get here, we have a timing
1591 // hole with systemDictionary updates and check_constraints
1592 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1593 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1594 compute_loader_lock_object(class_loader_h, THREAD)),
1595 "define called without lock");
1596 }
1597
1598 // Check class-loading constraints. Throw exception if violation is detected.
1599 // Grabs and releases SystemDictionary_lock
1600 // The check_constraints/find_class call and update_dictionary sequence
1601 // must be "atomic" for a specific class/classloader pair so we never
1602 // define two different instanceKlasses for that class/classloader pair.
1603 // Existing classloaders will call define_instance_class with the
1604 // classloader lock held
1605 // Parallel classloaders will call find_or_define_instance_class
1606 // which will require a token to perform the define class
1607 Symbol* name_h = k->name();
1608 Dictionary* dictionary = loader_data->dictionary();
1609 unsigned int d_hash = dictionary->compute_hash(name_h);
1610 check_constraints(d_hash, k, class_loader_h, true, CHECK);
1611
1612 // Register class just loaded with class loader (placed in ArrayList)
1613 // Note we do this before updating the dictionary, as this can
1614 // fail with an OutOfMemoryError (if it does, we will *not* put this
1615 // class in the dictionary and will not update the class hierarchy).
1616 // JVMTI FollowReferences needs to find the classes this way.
1617 if (k->class_loader() != NULL) {
1618 methodHandle m(THREAD, Universe::loader_addClass_method());
1619 JavaValue result(T_VOID);
1620 JavaCallArguments args(class_loader_h);
1621 args.push_oop(Handle(THREAD, k->java_mirror()));
1622 JavaCalls::call(&result, m, &args, CHECK);
1623 }
1624
1625 // Add the new class. We need recompile lock during update of CHA.
1626 {
1627 unsigned int p_hash = placeholders()->compute_hash(name_h);
1628 int p_index = placeholders()->hash_to_index(p_hash);
1629
1630 MutexLocker mu_r(THREAD, Compile_lock);
1631
1632 // Add to class hierarchy, initialize vtables, and do possible
1633 // deoptimizations.
1634 add_to_hierarchy(k, CHECK); // No exception, but can block
1635
1636 // Add to systemDictionary - so other classes can see it.
1637 // Grabs and releases SystemDictionary_lock
1638 update_dictionary(d_hash, p_index, p_hash,
1639 k, class_loader_h, THREAD);
1640 }
1641 k->eager_initialize(THREAD);
1642
1643 // notify jvmti
1644 if (JvmtiExport::should_post_class_load()) {
1645 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1646 JvmtiExport::post_class_load((JavaThread *) THREAD, k);
1647
1648 }
1649 post_class_define_event(k, loader_data);
1650 }
1651
1652 // Support parallel classloading
1653 // All parallel class loaders, including bootstrap classloader
1654 // lock a placeholder entry for this class/class_loader pair
1655 // to allow parallel defines of different classes for this class loader
1656 // With AllowParallelDefine flag==true, in case they do not synchronize around
1657 // FindLoadedClass/DefineClass, calls, we check for parallel
1658 // loading for them, wait if a defineClass is in progress
1659 // and return the initial requestor's results
1660 // This flag does not apply to the bootstrap classloader.
1661 // With AllowParallelDefine flag==false, call through to define_instance_class
1662 // which will throw LinkageError: duplicate class definition.
1663 // False is the requested default.
1664 // For better performance, the class loaders should synchronize
1665 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1666 // potentially waste time reading and parsing the bytestream.
1667 // Note: VM callers should ensure consistency of k/class_name,class_loader
1668 // Be careful when modifying this code: once you have run
1669 // placeholders()->find_and_add(PlaceholderTable::DEFINE_CLASS),
1670 // you need to find_and_remove it before returning.
1671 // So be careful to not exit with a CHECK_ macro betweeen these calls.
1672 InstanceKlass* SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader,
1673 InstanceKlass* k, TRAPS) {
1674
1675 Symbol* name_h = k->name(); // passed in class_name may be null
1676 ClassLoaderData* loader_data = class_loader_data(class_loader);
1677 Dictionary* dictionary = loader_data->dictionary();
1678
1679 unsigned int d_hash = dictionary->compute_hash(name_h);
1680
1681 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1682 unsigned int p_hash = placeholders()->compute_hash(name_h);
1683 int p_index = placeholders()->hash_to_index(p_hash);
1684 PlaceholderEntry* probe;
1685
1686 {
1687 MutexLocker mu(THREAD, SystemDictionary_lock);
1688 // First check if class already defined
1689 if (is_parallelDefine(class_loader)) {
1690 InstanceKlass* check = find_class(d_hash, name_h, dictionary);
1691 if (check != NULL) {
1692 return check;
1693 }
1694 }
1695
1696 // Acquire define token for this class/classloader
1697 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1698 // Wait if another thread defining in parallel
1699 // All threads wait - even those that will throw duplicate class: otherwise
1700 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1701 // if other thread has not finished updating dictionary
1702 while (probe->definer() != NULL) {
1703 SystemDictionary_lock->wait();
1704 }
1705 // Only special cases allow parallel defines and can use other thread's results
1706 // Other cases fall through, and may run into duplicate defines
1707 // caught by finding an entry in the SystemDictionary
1708 if (is_parallelDefine(class_loader) && (probe->instance_klass() != NULL)) {
1709 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1710 SystemDictionary_lock->notify_all();
1711 #ifdef ASSERT
1712 InstanceKlass* check = find_class(d_hash, name_h, dictionary);
1713 assert(check != NULL, "definer missed recording success");
1714 #endif
1715 return probe->instance_klass();
1716 } else {
1717 // This thread will define the class (even if earlier thread tried and had an error)
1718 probe->set_definer(THREAD);
1719 }
1720 }
1721
1722 define_instance_class(k, THREAD);
1723
1724 Handle linkage_exception = Handle(); // null handle
1725
1726 // definer must notify any waiting threads
1727 {
1728 MutexLocker mu(THREAD, SystemDictionary_lock);
1729 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1730 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1731 if (probe != NULL) {
1732 if (HAS_PENDING_EXCEPTION) {
1733 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1734 CLEAR_PENDING_EXCEPTION;
1735 } else {
1736 probe->set_instance_klass(k);
1737 }
1738 probe->set_definer(NULL);
1739 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1740 SystemDictionary_lock->notify_all();
1741 }
1742 }
1743
1744 // Can't throw exception while holding lock due to rank ordering
1745 if (linkage_exception() != NULL) {
1746 THROW_OOP_(linkage_exception(), NULL); // throws exception and returns
1747 }
1748
1749 return k;
1750 }
1751
1752 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1753 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1754 if (class_loader.is_null()) {
1755 return Handle(THREAD, _system_loader_lock_obj);
1756 } else {
1757 return class_loader;
1758 }
1759 }
1760
1761 // This method is added to check how often we have to wait to grab loader
1762 // lock. The results are being recorded in the performance counters defined in
1763 // ClassLoader::_sync_systemLoaderLockContentionRate and
1764 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1765 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1766 if (!UsePerfData) {
1767 return;
1768 }
1769
1770 assert(!loader_lock.is_null(), "NULL lock object");
1771
1772 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1773 == ObjectSynchronizer::owner_other) {
1774 // contention will likely happen, so increment the corresponding
1775 // contention counter.
1776 if (loader_lock() == _system_loader_lock_obj) {
1777 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1778 } else {
1779 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1780 }
1781 }
1782 }
1783
1784 // ----------------------------------------------------------------------------
1785 // Lookup
1786
1787 InstanceKlass* SystemDictionary::find_class(unsigned int hash,
1788 Symbol* class_name,
1789 Dictionary* dictionary) {
1790 assert_locked_or_safepoint(SystemDictionary_lock);
1791 int index = dictionary->hash_to_index(hash);
1792 return dictionary->find_class(index, hash, class_name);
1793 }
1794
1795
1796 // Basic find on classes in the midst of being loaded
1797 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1798 ClassLoaderData* loader_data) {
1799 assert_locked_or_safepoint(SystemDictionary_lock);
1800 unsigned int p_hash = placeholders()->compute_hash(class_name);
1801 int p_index = placeholders()->hash_to_index(p_hash);
1802 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1803 }
1804
1805
1806 // Used for assertions and verification only
1807 // Precalculating the hash and index is an optimization because there are many lookups
1808 // before adding the class.
1809 InstanceKlass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1810 assert_locked_or_safepoint(SystemDictionary_lock);
1811 #ifndef ASSERT
1812 guarantee(VerifyBeforeGC ||
1813 VerifyDuringGC ||
1814 VerifyBeforeExit ||
1815 VerifyDuringStartup ||
1816 VerifyAfterGC, "too expensive");
1817 #endif
1818
1819 Dictionary* dictionary = loader_data->dictionary();
1820 unsigned int d_hash = dictionary->compute_hash(class_name);
1821 return find_class(d_hash, class_name, dictionary);
1822 }
1823
1824
1825 // ----------------------------------------------------------------------------
1826 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1827 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1828 // before a new class is used.
1829
1830 void SystemDictionary::add_to_hierarchy(InstanceKlass* k, TRAPS) {
1831 assert(k != NULL, "just checking");
1832 if (Universe::is_fully_initialized()) {
1833 assert_locked_or_safepoint(Compile_lock);
1834 }
1835
1836 k->set_init_state(InstanceKlass::loaded);
1837 // make sure init_state store is already done.
1838 // The compiler reads the hierarchy outside of the Compile_lock.
1839 // Access ordering is used to add to hierarchy.
1840
1841 // Link into hierachy.
1842 k->append_to_sibling_list(); // add to superklass/sibling list
1843 k->process_interfaces(THREAD); // handle all "implements" declarations
1844
1845 // Now flush all code that depended on old class hierarchy.
1846 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1847 if (Universe::is_fully_initialized()) {
1848 CodeCache::flush_dependents_on(k);
1849 }
1850 }
1851
1852 // ----------------------------------------------------------------------------
1853 // GC support
1854
1855 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1856 // Note: anonymous classes are not in the SD.
1857 bool SystemDictionary::do_unloading(GCTimer* gc_timer) {
1858
1859 bool unloading_occurred;
1860 bool is_concurrent = !SafepointSynchronize::is_at_safepoint();
1861 {
1862 GCTraceTime(Debug, gc, phases) t("ClassLoaderData", gc_timer);
1863 assert_locked_or_safepoint(ClassLoaderDataGraph_lock); // caller locks.
1864 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1865 unloading_occurred = ClassLoaderDataGraph::do_unloading();
1866 if (unloading_occurred) {
1867 MutexLocker ml2(is_concurrent ? Module_lock : NULL);
1868 JFR_ONLY(Jfr::on_unloading_classes();)
1869
1870 MutexLocker ml1(is_concurrent ? SystemDictionary_lock : NULL);
1871 ClassLoaderDataGraph::clean_module_and_package_info();
1872 constraints()->purge_loader_constraints();
1873 resolution_errors()->purge_resolution_errors();
1874 }
1875 }
1876
1877 GCTraceTime(Debug, gc, phases) t("Trigger cleanups", gc_timer);
1878
1879 if (unloading_occurred) {
1880 SymbolTable::trigger_cleanup();
1881
1882 // Oops referenced by the protection domain cache table may get unreachable independently
1883 // of the class loader (eg. cached protection domain oops). So we need to
1884 // explicitly unlink them here.
1885 // All protection domain oops are linked to the caller class, so if nothing
1886 // unloads, this is not needed.
1887 _pd_cache_table->trigger_cleanup();
1888 }
1889
1890 return unloading_occurred;
1891 }
1892
1893 void SystemDictionary::oops_do(OopClosure* f, bool include_handles) {
1894 f->do_oop(&_java_system_loader);
1895 f->do_oop(&_java_platform_loader);
1896 f->do_oop(&_system_loader_lock_obj);
1897 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1898
1899 // Visit extra methods
1900 invoke_method_table()->oops_do(f);
1901
1902 if (include_handles) {
1903 OopStorageSet::vm_global()->oops_do(f);
1904 }
1905 }
1906
1907 // CDS: scan and relocate all classes referenced by _well_known_klasses[].
1908 void SystemDictionary::well_known_klasses_do(MetaspaceClosure* it) {
1909 for (int id = FIRST_WKID; id < WKID_LIMIT; id++) {
1910 it->push(well_known_klass_addr((WKID)id));
1911 }
1912 }
1913
1914 void SystemDictionary::methods_do(void f(Method*)) {
1915 // Walk methods in loaded classes
1916 MutexLocker ml(ClassLoaderDataGraph_lock);
1917 ClassLoaderDataGraph::methods_do(f);
1918 // Walk method handle intrinsics
1919 invoke_method_table()->methods_do(f);
1920 }
1921
1922 // ----------------------------------------------------------------------------
1923 // Initialization
1924
1925 void SystemDictionary::initialize(TRAPS) {
1926 // Allocate arrays
1927 _placeholders = new PlaceholderTable(_placeholder_table_size);
1928 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1929 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1930 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
1931 _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
1932
1933 // Allocate private object used as system class loader lock
1934 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
1935 // Initialize basic classes
1936 resolve_well_known_classes(CHECK);
1937 }
1938
1939 // Compact table of directions on the initialization of klasses:
1940 static const short wk_init_info[] = {
1941 #define WK_KLASS_INIT_INFO(name, symbol) \
1942 ((short)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol)),
1943
1944 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1945 #undef WK_KLASS_INIT_INFO
1946 0
1947 };
1948
1949 #ifdef ASSERT
1950 bool SystemDictionary::is_well_known_klass(Symbol* class_name) {
1951 int sid;
1952 for (int i = 0; (sid = wk_init_info[i]) != 0; i++) {
1953 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1954 if (class_name == symbol) {
1955 return true;
1956 }
1957 }
1958 return false;
1959 }
1960 #endif
1961
1962 bool SystemDictionary::resolve_wk_klass(WKID id, TRAPS) {
1963 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1964 int sid = wk_init_info[id - FIRST_WKID];
1965 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1966 InstanceKlass** klassp = &_well_known_klasses[id];
1967
1968 #if INCLUDE_CDS
1969 if (UseSharedSpaces && !JvmtiExport::should_post_class_prepare()) {
1970 InstanceKlass* k = *klassp;
1971 assert(k->is_shared_boot_class(), "must be");
1972
1973 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1974 quick_resolve(k, loader_data, Handle(), CHECK_false);
1975 return true;
1976 }
1977 #endif // INCLUDE_CDS
1978
1979 if (!is_wk_klass_loaded(*klassp)) {
1980 Klass* k = resolve_or_fail(symbol, true, CHECK_false);
1981 (*klassp) = InstanceKlass::cast(k);
1982 }
1983 return ((*klassp) != NULL);
1984 }
1985
1986 void SystemDictionary::resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1987 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1988 for (int id = (int)start_id; id < (int)limit_id; id++) {
1989 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1990 resolve_wk_klass((WKID)id, CHECK);
1991 }
1992
1993 // move the starting value forward to the limit:
1994 start_id = limit_id;
1995 }
1996
1997 void SystemDictionary::resolve_well_known_classes(TRAPS) {
1998 assert(!Object_klass_loaded(), "well-known classes should only be initialized once");
1999
2000 // Create the ModuleEntry for java.base. This call needs to be done here,
2001 // after vmSymbols::initialize() is called but before any classes are pre-loaded.
2002 ClassLoader::classLoader_init2(CHECK);
2003
2004 // Preload commonly used klasses
2005 WKID scan = FIRST_WKID;
2006 // first do Object, then String, Class
2007 #if INCLUDE_CDS
2008 if (UseSharedSpaces) {
2009 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
2010
2011 // It's unsafe to access the archived heap regions before they
2012 // are fixed up, so we must do the fixup as early as possible
2013 // before the archived java objects are accessed by functions
2014 // such as java_lang_Class::restore_archived_mirror and
2015 // ConstantPool::restore_unshareable_info (restores the archived
2016 // resolved_references array object).
2017 //
2018 // HeapShared::fixup_mapped_heap_regions() fills the empty
2019 // spaces in the archived heap regions and may use
2020 // SystemDictionary::Object_klass(), so we can do this only after
2021 // Object_klass is resolved. See the above resolve_wk_klasses_through()
2022 // call. No mirror objects are accessed/restored in the above call.
2023 // Mirrors are restored after java.lang.Class is loaded.
2024 HeapShared::fixup_mapped_heap_regions();
2025
2026 // Initialize the constant pool for the Object_class
2027 assert(Object_klass()->is_shared(), "must be");
2028 Object_klass()->constants()->restore_unshareable_info(CHECK);
2029 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2030 } else
2031 #endif
2032 {
2033 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2034 }
2035
2036 assert(WK_KLASS(Object_klass) != NULL, "well-known classes should now be initialized");
2037
2038 java_lang_Object::register_natives(CHECK);
2039
2040 // Calculate offsets for String and Class classes since they are loaded and
2041 // can be used after this point.
2042 java_lang_String::compute_offsets();
2043 java_lang_Class::compute_offsets();
2044
2045 // Fixup mirrors for classes loaded before java.lang.Class.
2046 Universe::initialize_basic_type_mirrors(CHECK);
2047 Universe::fixup_mirrors(CHECK);
2048
2049 // do a bunch more:
2050 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
2051
2052 // Preload ref klasses and set reference types
2053 WK_KLASS(Reference_klass)->set_reference_type(REF_OTHER);
2054 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
2055
2056 resolve_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
2057 WK_KLASS(SoftReference_klass)->set_reference_type(REF_SOFT);
2058 WK_KLASS(WeakReference_klass)->set_reference_type(REF_WEAK);
2059 WK_KLASS(FinalReference_klass)->set_reference_type(REF_FINAL);
2060 WK_KLASS(PhantomReference_klass)->set_reference_type(REF_PHANTOM);
2061
2062 // JSR 292 classes
2063 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
2064 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
2065 resolve_wk_klasses_until(jsr292_group_start, scan, CHECK);
2066 resolve_wk_klasses_through(jsr292_group_end, scan, CHECK);
2067 WKID last = WKID_LIMIT;
2068 resolve_wk_klasses_until(last, scan, CHECK);
2069
2070 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
2071 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
2072 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
2073 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
2074 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
2075 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
2076 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
2077 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
2078 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
2079 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
2080
2081 #ifdef ASSERT
2082 if (UseSharedSpaces) {
2083 JVMTI_ONLY(assert(JvmtiExport::is_early_phase(),
2084 "All well known classes must be resolved in JVMTI early phase"));
2085 for (int i = FIRST_WKID; i < last; i++) {
2086 InstanceKlass* k = _well_known_klasses[i];
2087 assert(k->is_shared(), "must not be replaced by JVMTI class file load hook");
2088 }
2089 }
2090 #endif
2091 }
2092
2093 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
2094 // If so, returns the basic type it holds. If not, returns T_OBJECT.
2095 BasicType SystemDictionary::box_klass_type(Klass* k) {
2096 assert(k != NULL, "");
2097 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
2098 if (_box_klasses[i] == k)
2099 return (BasicType)i;
2100 }
2101 return T_OBJECT;
2102 }
2103
2104 // Constraints on class loaders. The details of the algorithm can be
2105 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
2106 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
2107 // that the dictionary needs to maintain a set of contraints that
2108 // must be satisfied by all classes in the dictionary.
2109 // if defining is true, then LinkageError if already in dictionary
2110 // if initiating loader, then ok if InstanceKlass matches existing entry
2111
2112 void SystemDictionary::check_constraints(unsigned int d_hash,
2113 InstanceKlass* k,
2114 Handle class_loader,
2115 bool defining,
2116 TRAPS) {
2117 ResourceMark rm(THREAD);
2118 stringStream ss;
2119 bool throwException = false;
2120
2121 {
2122 Symbol *name = k->name();
2123 ClassLoaderData *loader_data = class_loader_data(class_loader);
2124
2125 MutexLocker mu(THREAD, SystemDictionary_lock);
2126
2127 InstanceKlass* check = find_class(d_hash, name, loader_data->dictionary());
2128 if (check != NULL) {
2129 // If different InstanceKlass - duplicate class definition,
2130 // else - ok, class loaded by a different thread in parallel.
2131 // We should only have found it if it was done loading and ok to use.
2132 // The dictionary only holds instance classes, placeholders
2133 // also hold array classes.
2134
2135 assert(check->is_instance_klass(), "noninstance in systemdictionary");
2136 if ((defining == true) || (k != check)) {
2137 throwException = true;
2138 ss.print("loader %s", loader_data->loader_name_and_id());
2139 ss.print(" attempted duplicate %s definition for %s. (%s)",
2140 k->external_kind(), k->external_name(), k->class_in_module_of_loader(false, true));
2141 } else {
2142 return;
2143 }
2144 }
2145
2146 #ifdef ASSERT
2147 Symbol* ph_check = find_placeholder(name, loader_data);
2148 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2149 #endif
2150
2151 if (throwException == false) {
2152 if (constraints()->check_or_update(k, class_loader, name) == false) {
2153 throwException = true;
2154 ss.print("loader constraint violation: loader %s", loader_data->loader_name_and_id());
2155 ss.print(" wants to load %s %s.",
2156 k->external_kind(), k->external_name());
2157 Klass *existing_klass = constraints()->find_constrained_klass(name, class_loader);
2158 if (existing_klass != NULL && existing_klass->class_loader() != class_loader()) {
2159 ss.print(" A different %s with the same name was previously loaded by %s. (%s)",
2160 existing_klass->external_kind(),
2161 existing_klass->class_loader_data()->loader_name_and_id(),
2162 existing_klass->class_in_module_of_loader(false, true));
2163 } else {
2164 ss.print(" (%s)", k->class_in_module_of_loader(false, true));
2165 }
2166 }
2167 }
2168 }
2169
2170 // Throw error now if needed (cannot throw while holding
2171 // SystemDictionary_lock because of rank ordering)
2172 if (throwException == true) {
2173 THROW_MSG(vmSymbols::java_lang_LinkageError(), ss.as_string());
2174 }
2175 }
2176
2177 // Update class loader data dictionary - done after check_constraint and add_to_hierachy
2178 // have been called.
2179 void SystemDictionary::update_dictionary(unsigned int d_hash,
2180 int p_index, unsigned int p_hash,
2181 InstanceKlass* k,
2182 Handle class_loader,
2183 TRAPS) {
2184 // Compile_lock prevents systemDictionary updates during compilations
2185 assert_locked_or_safepoint(Compile_lock);
2186 Symbol* name = k->name();
2187 ClassLoaderData *loader_data = class_loader_data(class_loader);
2188
2189 {
2190 MutexLocker mu1(THREAD, SystemDictionary_lock);
2191
2192 // Make a new dictionary entry.
2193 Dictionary* dictionary = loader_data->dictionary();
2194 InstanceKlass* sd_check = find_class(d_hash, name, dictionary);
2195 if (sd_check == NULL) {
2196 dictionary->add_klass(d_hash, name, k);
2197 }
2198 #ifdef ASSERT
2199 sd_check = find_class(d_hash, name, dictionary);
2200 assert (sd_check != NULL, "should have entry in dictionary");
2201 // Note: there may be a placeholder entry: for circularity testing
2202 // or for parallel defines
2203 #endif
2204 SystemDictionary_lock->notify_all();
2205 }
2206 }
2207
2208
2209 // Try to find a class name using the loader constraints. The
2210 // loader constraints might know about a class that isn't fully loaded
2211 // yet and these will be ignored.
2212 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2213 Symbol* class_name, Handle class_loader, TRAPS) {
2214
2215 // First see if it has been loaded directly.
2216 // Force the protection domain to be null. (This removes protection checks.)
2217 Handle no_protection_domain;
2218 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2219 no_protection_domain, CHECK_NULL);
2220 if (klass != NULL)
2221 return klass;
2222
2223 // Now look to see if it has been loaded elsewhere, and is subject to
2224 // a loader constraint that would require this loader to return the
2225 // klass that is already loaded.
2226 if (Signature::is_array(class_name)) {
2227 // For array classes, their Klass*s are not kept in the
2228 // constraint table. The element Klass*s are.
2229 SignatureStream ss(class_name, false);
2230 int ndims = ss.skip_array_prefix(); // skip all '['s
2231 BasicType t = ss.type();
2232 if (t != T_OBJECT) {
2233 klass = Universe::typeArrayKlassObj(t);
2234 } else {
2235 MutexLocker mu(THREAD, SystemDictionary_lock);
2236 klass = constraints()->find_constrained_klass(ss.as_symbol(), class_loader);
2237 }
2238 // If element class already loaded, allocate array klass
2239 if (klass != NULL) {
2240 klass = klass->array_klass_or_null(ndims);
2241 }
2242 } else {
2243 MutexLocker mu(THREAD, SystemDictionary_lock);
2244 // Non-array classes are easy: simply check the constraint table.
2245 klass = constraints()->find_constrained_klass(class_name, class_loader);
2246 }
2247
2248 return klass;
2249 }
2250
2251
2252 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2253 Handle class_loader1,
2254 Handle class_loader2,
2255 Thread* THREAD) {
2256 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2257 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2258
2259 Symbol* constraint_name = NULL;
2260
2261 if (!Signature::is_array(class_name)) {
2262 constraint_name = class_name;
2263 } else {
2264 // For array classes, their Klass*s are not kept in the
2265 // constraint table. The element classes are.
2266 SignatureStream ss(class_name, false);
2267 ss.skip_array_prefix(); // skip all '['s
2268 if (!ss.has_envelope()) {
2269 return true; // primitive types always pass
2270 }
2271 constraint_name = ss.as_symbol();
2272 // Increment refcount to keep constraint_name alive after
2273 // SignatureStream is destructed. It will be decremented below
2274 // before returning.
2275 constraint_name->increment_refcount();
2276 }
2277
2278 Dictionary* dictionary1 = loader_data1->dictionary();
2279 unsigned int d_hash1 = dictionary1->compute_hash(constraint_name);
2280
2281 Dictionary* dictionary2 = loader_data2->dictionary();
2282 unsigned int d_hash2 = dictionary2->compute_hash(constraint_name);
2283
2284 {
2285 MutexLocker mu_s(THREAD, SystemDictionary_lock);
2286 InstanceKlass* klass1 = find_class(d_hash1, constraint_name, dictionary1);
2287 InstanceKlass* klass2 = find_class(d_hash2, constraint_name, dictionary2);
2288 bool result = constraints()->add_entry(constraint_name, klass1, class_loader1,
2289 klass2, class_loader2);
2290 if (Signature::is_array(class_name)) {
2291 constraint_name->decrement_refcount();
2292 }
2293 return result;
2294 }
2295 }
2296
2297 // Add entry to resolution error table to record the error when the first
2298 // attempt to resolve a reference to a class has failed.
2299 void SystemDictionary::add_resolution_error(const constantPoolHandle& pool, int which,
2300 Symbol* error, Symbol* message) {
2301 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2302 int index = resolution_errors()->hash_to_index(hash);
2303 {
2304 MutexLocker ml(Thread::current(), SystemDictionary_lock);
2305 resolution_errors()->add_entry(index, hash, pool, which, error, message);
2306 }
2307 }
2308
2309 // Delete a resolution error for RedefineClasses for a constant pool is going away
2310 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2311 resolution_errors()->delete_entry(pool);
2312 }
2313
2314 // Lookup resolution error table. Returns error if found, otherwise NULL.
2315 Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool, int which,
2316 Symbol** message) {
2317 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2318 int index = resolution_errors()->hash_to_index(hash);
2319 {
2320 MutexLocker ml(Thread::current(), SystemDictionary_lock);
2321 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2322 if (entry != NULL) {
2323 *message = entry->message();
2324 return entry->error();
2325 } else {
2326 return NULL;
2327 }
2328 }
2329 }
2330
2331
2332 // Signature constraints ensure that callers and callees agree about
2333 // the meaning of type names in their signatures. This routine is the
2334 // intake for constraints. It collects them from several places:
2335 //
2336 // * LinkResolver::resolve_method (if check_access is true) requires
2337 // that the resolving class (the caller) and the defining class of
2338 // the resolved method (the callee) agree on each type in the
2339 // method's signature.
2340 //
2341 // * LinkResolver::resolve_interface_method performs exactly the same
2342 // checks.
2343 //
2344 // * LinkResolver::resolve_field requires that the constant pool
2345 // attempting to link to a field agree with the field's defining
2346 // class about the type of the field signature.
2347 //
2348 // * klassVtable::initialize_vtable requires that, when a class
2349 // overrides a vtable entry allocated by a superclass, that the
2350 // overriding method (i.e., the callee) agree with the superclass
2351 // on each type in the method's signature.
2352 //
2353 // * klassItable::initialize_itable requires that, when a class fills
2354 // in its itables, for each non-abstract method installed in an
2355 // itable, the method (i.e., the callee) agree with the interface
2356 // on each type in the method's signature.
2357 //
2358 // All those methods have a boolean (check_access, checkconstraints)
2359 // which turns off the checks. This is used from specialized contexts
2360 // such as bootstrapping, dumping, and debugging.
2361 //
2362 // No direct constraint is placed between the class and its
2363 // supertypes. Constraints are only placed along linked relations
2364 // between callers and callees. When a method overrides or implements
2365 // an abstract method in a supertype (superclass or interface), the
2366 // constraints are placed as if the supertype were the caller to the
2367 // overriding method. (This works well, since callers to the
2368 // supertype have already established agreement between themselves and
2369 // the supertype.) As a result of all this, a class can disagree with
2370 // its supertype about the meaning of a type name, as long as that
2371 // class neither calls a relevant method of the supertype, nor is
2372 // called (perhaps via an override) from the supertype.
2373 //
2374 //
2375 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2376 //
2377 // Make sure all class components (including arrays) in the given
2378 // signature will be resolved to the same class in both loaders.
2379 // Returns the name of the type that failed a loader constraint check, or
2380 // NULL if no constraint failed. No exception except OOME is thrown.
2381 // Arrays are not added to the loader constraint table, their elements are.
2382 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2383 Handle loader1, Handle loader2,
2384 bool is_method, TRAPS) {
2385 // Nothing to do if loaders are the same.
2386 if (loader1() == loader2()) {
2387 return NULL;
2388 }
2389
2390 for (SignatureStream ss(signature, is_method); !ss.is_done(); ss.next()) {
2391 if (ss.is_reference()) {
2392 Symbol* sig = ss.as_symbol();
2393 // Note: In the future, if template-like types can take
2394 // arguments, we will want to recognize them and dig out class
2395 // names hiding inside the argument lists.
2396 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2397 return sig;
2398 }
2399 }
2400 }
2401 return NULL;
2402 }
2403
2404
2405 Method* SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2406 Symbol* signature,
2407 TRAPS) {
2408 methodHandle empty;
2409 assert(MethodHandles::is_signature_polymorphic(iid) &&
2410 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2411 iid != vmIntrinsics::_invokeGeneric,
2412 "must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid));
2413
2414 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2415 int index = invoke_method_table()->hash_to_index(hash);
2416 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2417 methodHandle m;
2418 if (spe == NULL || spe->method() == NULL) {
2419 spe = NULL;
2420 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2421 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_NULL);
2422 if (!Arguments::is_interpreter_only()) {
2423 // Generate a compiled form of the MH intrinsic.
2424 AdapterHandlerLibrary::create_native_wrapper(m);
2425 // Check if have the compiled code.
2426 if (!m->has_compiled_code()) {
2427 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(),
2428 "Out of space in CodeCache for method handle intrinsic");
2429 }
2430 }
2431 // Now grab the lock. We might have to throw away the new method,
2432 // if a racing thread has managed to install one at the same time.
2433 {
2434 MutexLocker ml(THREAD, SystemDictionary_lock);
2435 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2436 if (spe == NULL)
2437 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2438 if (spe->method() == NULL)
2439 spe->set_method(m());
2440 }
2441 }
2442
2443 assert(spe != NULL && spe->method() != NULL, "");
2444 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2445 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2446 "MH intrinsic invariant");
2447 return spe->method();
2448 }
2449
2450 // Helper for unpacking the return value from linkMethod and linkCallSite.
2451 static Method* unpack_method_and_appendix(Handle mname,
2452 Klass* accessing_klass,
2453 objArrayHandle appendix_box,
2454 Handle* appendix_result,
2455 TRAPS) {
2456 if (mname.not_null()) {
2457 Method* m = java_lang_invoke_MemberName::vmtarget(mname());
2458 if (m != NULL) {
2459 oop appendix = appendix_box->obj_at(0);
2460 if (TraceMethodHandles) {
2461 #ifndef PRODUCT
2462 ttyLocker ttyl;
2463 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2464 m->print();
2465 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2466 tty->cr();
2467 #endif //PRODUCT
2468 }
2469 (*appendix_result) = Handle(THREAD, appendix);
2470 // the target is stored in the cpCache and if a reference to this
2471 // MemberName is dropped we need a way to make sure the
2472 // class_loader containing this method is kept alive.
2473 methodHandle mh(THREAD, m); // record_dependency can safepoint.
2474 ClassLoaderData* this_key = accessing_klass->class_loader_data();
2475 this_key->record_dependency(m->method_holder());
2476 return mh();
2477 }
2478 }
2479 THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives");
2480 }
2481
2482 Method* SystemDictionary::find_method_handle_invoker(Klass* klass,
2483 Symbol* name,
2484 Symbol* signature,
2485 Klass* accessing_klass,
2486 Handle *appendix_result,
2487 TRAPS) {
2488 assert(THREAD->can_call_java() ,"");
2489 Handle method_type =
2490 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_NULL);
2491
2492 int ref_kind = JVM_REF_invokeVirtual;
2493 oop name_oop = StringTable::intern(name, CHECK_NULL);
2494 Handle name_str (THREAD, name_oop);
2495 objArrayHandle appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK_NULL);
2496 assert(appendix_box->obj_at(0) == NULL, "");
2497
2498 // This should not happen. JDK code should take care of that.
2499 if (accessing_klass == NULL || method_type.is_null()) {
2500 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "bad invokehandle");
2501 }
2502
2503 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2504 JavaCallArguments args;
2505 args.push_oop(Handle(THREAD, accessing_klass->java_mirror()));
2506 args.push_int(ref_kind);
2507 args.push_oop(Handle(THREAD, klass->java_mirror()));
2508 args.push_oop(name_str);
2509 args.push_oop(method_type);
2510 args.push_oop(appendix_box);
2511 JavaValue result(T_OBJECT);
2512 JavaCalls::call_static(&result,
2513 SystemDictionary::MethodHandleNatives_klass(),
2514 vmSymbols::linkMethod_name(),
2515 vmSymbols::linkMethod_signature(),
2516 &args, CHECK_NULL);
2517 Handle mname(THREAD, (oop) result.get_jobject());
2518 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2519 }
2520
2521 // Decide if we can globally cache a lookup of this class, to be returned to any client that asks.
2522 // We must ensure that all class loaders everywhere will reach this class, for any client.
2523 // This is a safe bet for public classes in java.lang, such as Object and String.
2524 // We also include public classes in java.lang.invoke, because they appear frequently in system-level method types.
2525 // Out of an abundance of caution, we do not include any other classes, not even for packages like java.util.
2526 static bool is_always_visible_class(oop mirror) {
2527 Klass* klass = java_lang_Class::as_Klass(mirror);
2528 if (klass->is_objArray_klass()) {
2529 klass = ObjArrayKlass::cast(klass)->bottom_klass(); // check element type
2530 }
2531 if (klass->is_typeArray_klass()) {
2532 return true; // primitive array
2533 }
2534 assert(klass->is_instance_klass(), "%s", klass->external_name());
2535 return klass->is_public() &&
2536 (InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::Object_klass()) || // java.lang
2537 InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::MethodHandle_klass())); // java.lang.invoke
2538 }
2539
2540 // Find or construct the Java mirror (java.lang.Class instance) for
2541 // the given field type signature, as interpreted relative to the
2542 // given class loader. Handles primitives, void, references, arrays,
2543 // and all other reflectable types, except method types.
2544 // N.B. Code in reflection should use this entry point.
2545 Handle SystemDictionary::find_java_mirror_for_type(Symbol* signature,
2546 Klass* accessing_klass,
2547 Handle class_loader,
2548 Handle protection_domain,
2549 SignatureStream::FailureMode failure_mode,
2550 TRAPS) {
2551 assert(accessing_klass == NULL || (class_loader.is_null() && protection_domain.is_null()),
2552 "one or the other, or perhaps neither");
2553
2554 // What we have here must be a valid field descriptor,
2555 // and all valid field descriptors are supported.
2556 // Produce the same java.lang.Class that reflection reports.
2557 if (accessing_klass != NULL) {
2558 class_loader = Handle(THREAD, accessing_klass->class_loader());
2559 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2560 }
2561 ResolvingSignatureStream ss(signature, class_loader, protection_domain, false);
2562 oop mirror_oop = ss.as_java_mirror(failure_mode, CHECK_NH);
2563 if (mirror_oop == NULL) {
2564 return Handle(); // report failure this way
2565 }
2566 Handle mirror(THREAD, mirror_oop);
2567
2568 if (accessing_klass != NULL) {
2569 // Check accessibility, emulating ConstantPool::verify_constant_pool_resolve.
2570 Klass* sel_klass = java_lang_Class::as_Klass(mirror());
2571 if (sel_klass != NULL) {
2572 bool fold_type_to_class = true;
2573 LinkResolver::check_klass_accessability(accessing_klass, sel_klass,
2574 fold_type_to_class, CHECK_NH);
2575 }
2576 }
2577 return mirror;
2578 }
2579
2580
2581 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2582 // signature, as interpreted relative to the given class loader.
2583 // Because of class loader constraints, all method handle usage must be
2584 // consistent with this loader.
2585 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2586 Klass* accessing_klass,
2587 TRAPS) {
2588 Handle empty;
2589 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2590 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2591 int index = invoke_method_table()->hash_to_index(hash);
2592 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2593 if (spe != NULL && spe->method_type() != NULL) {
2594 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2595 return Handle(THREAD, spe->method_type());
2596 } else if (!THREAD->can_call_java()) {
2597 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2598 return Handle(); // do not attempt from within compiler, unless it was cached
2599 }
2600
2601 Handle class_loader, protection_domain;
2602 if (accessing_klass != NULL) {
2603 class_loader = Handle(THREAD, accessing_klass->class_loader());
2604 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2605 }
2606 bool can_be_cached = true;
2607 int npts = ArgumentCount(signature).size();
2608 objArrayHandle pts = oopFactory::new_objArray_handle(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2609 int arg = 0;
2610 Handle rt; // the return type from the signature
2611 ResourceMark rm(THREAD);
2612 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2613 oop mirror = NULL;
2614 if (can_be_cached) {
2615 // Use neutral class loader to lookup candidate classes to be placed in the cache.
2616 mirror = ss.as_java_mirror(Handle(), Handle(),
2617 SignatureStream::ReturnNull, CHECK_(empty));
2618 if (mirror == NULL || (ss.is_reference() && !is_always_visible_class(mirror))) {
2619 // Fall back to accessing_klass context.
2620 can_be_cached = false;
2621 }
2622 }
2623 if (!can_be_cached) {
2624 // Resolve, throwing a real error if it doesn't work.
2625 mirror = ss.as_java_mirror(class_loader, protection_domain,
2626 SignatureStream::NCDFError, CHECK_(empty));
2627 }
2628 assert(mirror != NULL, "%s", ss.as_symbol()->as_C_string());
2629 if (ss.at_return_type())
2630 rt = Handle(THREAD, mirror);
2631 else
2632 pts->obj_at_put(arg++, mirror);
2633
2634 // Check accessibility.
2635 if (!java_lang_Class::is_primitive(mirror) && accessing_klass != NULL) {
2636 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2637 mirror = NULL; // safety
2638 // Emulate ConstantPool::verify_constant_pool_resolve.
2639 bool fold_type_to_class = true;
2640 LinkResolver::check_klass_accessability(accessing_klass, sel_klass,
2641 fold_type_to_class, CHECK_(empty));
2642 }
2643 }
2644 assert(arg == npts, "");
2645
2646 // call java.lang.invoke.MethodHandleNatives::findMethodHandleType(Class rt, Class[] pts) -> MethodType
2647 JavaCallArguments args(Handle(THREAD, rt()));
2648 args.push_oop(pts);
2649 JavaValue result(T_OBJECT);
2650 JavaCalls::call_static(&result,
2651 SystemDictionary::MethodHandleNatives_klass(),
2652 vmSymbols::findMethodHandleType_name(),
2653 vmSymbols::findMethodHandleType_signature(),
2654 &args, CHECK_(empty));
2655 Handle method_type(THREAD, (oop) result.get_jobject());
2656
2657 if (can_be_cached) {
2658 // We can cache this MethodType inside the JVM.
2659 MutexLocker ml(THREAD, SystemDictionary_lock);
2660 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2661 if (spe == NULL)
2662 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2663 if (spe->method_type() == NULL) {
2664 spe->set_method_type(method_type());
2665 }
2666 }
2667
2668 // report back to the caller with the MethodType
2669 return method_type;
2670 }
2671
2672 Handle SystemDictionary::find_field_handle_type(Symbol* signature,
2673 Klass* accessing_klass,
2674 TRAPS) {
2675 Handle empty;
2676 ResourceMark rm(THREAD);
2677 SignatureStream ss(signature, /*is_method=*/ false);
2678 if (!ss.is_done()) {
2679 Handle class_loader, protection_domain;
2680 if (accessing_klass != NULL) {
2681 class_loader = Handle(THREAD, accessing_klass->class_loader());
2682 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2683 }
2684 oop mirror = ss.as_java_mirror(class_loader, protection_domain, SignatureStream::NCDFError, CHECK_(empty));
2685 ss.next();
2686 if (ss.is_done()) {
2687 return Handle(THREAD, mirror);
2688 }
2689 }
2690 return empty;
2691 }
2692
2693 // Ask Java code to find or construct a method handle constant.
2694 Handle SystemDictionary::link_method_handle_constant(Klass* caller,
2695 int ref_kind, //e.g., JVM_REF_invokeVirtual
2696 Klass* callee,
2697 Symbol* name,
2698 Symbol* signature,
2699 TRAPS) {
2700 Handle empty;
2701 if (caller == NULL) {
2702 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2703 }
2704 Handle name_str = java_lang_String::create_from_symbol(name, CHECK_(empty));
2705 Handle signature_str = java_lang_String::create_from_symbol(signature, CHECK_(empty));
2706
2707 // Put symbolic info from the MH constant into freshly created MemberName and resolve it.
2708 Handle mname = MemberName_klass()->allocate_instance_handle(CHECK_(empty));
2709 java_lang_invoke_MemberName::set_clazz(mname(), callee->java_mirror());
2710 java_lang_invoke_MemberName::set_name (mname(), name_str());
2711 java_lang_invoke_MemberName::set_type (mname(), signature_str());
2712 java_lang_invoke_MemberName::set_flags(mname(), MethodHandles::ref_kind_to_flags(ref_kind));
2713
2714 if (ref_kind == JVM_REF_invokeVirtual &&
2715 MethodHandles::is_signature_polymorphic_public_name(callee, name)) {
2716 // Skip resolution for public signature polymorphic methods such as
2717 // j.l.i.MethodHandle.invoke()/invokeExact() and those on VarHandle
2718 // They require appendix argument which MemberName resolution doesn't handle.
2719 // There's special logic on JDK side to handle them
2720 // (see MethodHandles.linkMethodHandleConstant() and MethodHandles.findVirtualForMH()).
2721 } else {
2722 MethodHandles::resolve_MemberName(mname, caller, /*speculative_resolve*/false, CHECK_(empty));
2723 }
2724
2725 // After method/field resolution succeeded, it's safe to resolve MH signature as well.
2726 Handle type = MethodHandles::resolve_MemberName_type(mname, caller, CHECK_(empty));
2727
2728 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2729 JavaCallArguments args;
2730 args.push_oop(Handle(THREAD, caller->java_mirror())); // the referring class
2731 args.push_int(ref_kind);
2732 args.push_oop(Handle(THREAD, callee->java_mirror())); // the target class
2733 args.push_oop(name_str);
2734 args.push_oop(type);
2735 JavaValue result(T_OBJECT);
2736 JavaCalls::call_static(&result,
2737 SystemDictionary::MethodHandleNatives_klass(),
2738 vmSymbols::linkMethodHandleConstant_name(),
2739 vmSymbols::linkMethodHandleConstant_signature(),
2740 &args, CHECK_(empty));
2741 return Handle(THREAD, (oop) result.get_jobject());
2742 }
2743
2744 // Ask Java to run a bootstrap method, in order to create a dynamic call site
2745 // while linking an invokedynamic op, or compute a constant for Dynamic_info CP entry
2746 // with linkage results being stored back into the bootstrap specifier.
2747 void SystemDictionary::invoke_bootstrap_method(BootstrapInfo& bootstrap_specifier, TRAPS) {
2748 // Resolve the bootstrap specifier, its name, type, and static arguments
2749 bootstrap_specifier.resolve_bsm(CHECK);
2750
2751 // This should not happen. JDK code should take care of that.
2752 if (bootstrap_specifier.caller() == NULL || bootstrap_specifier.type_arg().is_null()) {
2753 THROW_MSG(vmSymbols::java_lang_InternalError(), "Invalid bootstrap method invocation with no caller or type argument");
2754 }
2755
2756 bool is_indy = bootstrap_specifier.is_method_call();
2757 objArrayHandle appendix_box;
2758 if (is_indy) {
2759 // Some method calls may require an appendix argument. Arrange to receive it.
2760 appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK);
2761 assert(appendix_box->obj_at(0) == NULL, "");
2762 }
2763
2764 // call condy: java.lang.invoke.MethodHandleNatives::linkDynamicConstant(caller, condy_index, bsm, type, info)
2765 // indy: java.lang.invoke.MethodHandleNatives::linkCallSite(caller, indy_index, bsm, name, mtype, info, &appendix)
2766 JavaCallArguments args;
2767 args.push_oop(Handle(THREAD, bootstrap_specifier.caller_mirror()));
2768 args.push_int(bootstrap_specifier.bss_index());
2769 args.push_oop(bootstrap_specifier.bsm());
2770 args.push_oop(bootstrap_specifier.name_arg());
2771 args.push_oop(bootstrap_specifier.type_arg());
2772 args.push_oop(bootstrap_specifier.arg_values());
2773 if (is_indy) {
2774 args.push_oop(appendix_box);
2775 }
2776 JavaValue result(T_OBJECT);
2777 JavaCalls::call_static(&result,
2778 SystemDictionary::MethodHandleNatives_klass(),
2779 is_indy ? vmSymbols::linkCallSite_name() : vmSymbols::linkDynamicConstant_name(),
2780 is_indy ? vmSymbols::linkCallSite_signature() : vmSymbols::linkDynamicConstant_signature(),
2781 &args, CHECK);
2782
2783 Handle value(THREAD, (oop) result.get_jobject());
2784 if (is_indy) {
2785 Handle appendix;
2786 Method* method = unpack_method_and_appendix(value,
2787 bootstrap_specifier.caller(),
2788 appendix_box,
2789 &appendix, CHECK);
2790 methodHandle mh(THREAD, method);
2791 bootstrap_specifier.set_resolved_method(mh, appendix);
2792 } else {
2793 bootstrap_specifier.set_resolved_value(value);
2794 }
2795
2796 // sanity check
2797 assert(bootstrap_specifier.is_resolved() ||
2798 (bootstrap_specifier.is_method_call() &&
2799 bootstrap_specifier.resolved_method().not_null()), "bootstrap method call failed");
2800 }
2801
2802 // Protection domain cache table handling
2803
2804 ProtectionDomainCacheEntry* SystemDictionary::cache_get(Handle protection_domain) {
2805 return _pd_cache_table->get(protection_domain);
2806 }
2807
2808 // ----------------------------------------------------------------------------
2809
2810 void SystemDictionary::print_on(outputStream *st) {
2811 CDS_ONLY(SystemDictionaryShared::print_on(st));
2812 GCMutexLocker mu(SystemDictionary_lock);
2813
2814 ClassLoaderDataGraph::print_dictionary(st);
2815
2816 // Placeholders
2817 placeholders()->print_on(st);
2818 st->cr();
2819
2820 // loader constraints - print under SD_lock
2821 constraints()->print_on(st);
2822 st->cr();
2823
2824 _pd_cache_table->print_on(st);
2825 st->cr();
2826 }
2827
2828 void SystemDictionary::print() { print_on(tty); }
2829
2830 void SystemDictionary::verify() {
2831 guarantee(constraints() != NULL,
2832 "Verify of loader constraints failed");
2833 guarantee(placeholders()->number_of_entries() >= 0,
2834 "Verify of placeholders failed");
2835
2836 GCMutexLocker mu(SystemDictionary_lock);
2837
2838 // Verify dictionary
2839 ClassLoaderDataGraph::verify_dictionary();
2840
2841 placeholders()->verify();
2842
2843 // Verify constraint table
2844 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2845 constraints()->verify(placeholders());
2846
2847 _pd_cache_table->verify();
2848 }
2849
2850 void SystemDictionary::dump(outputStream *st, bool verbose) {
2851 assert_locked_or_safepoint(SystemDictionary_lock);
2852 if (verbose) {
2853 print_on(st);
2854 } else {
2855 CDS_ONLY(SystemDictionaryShared::print_table_statistics(st));
2856 ClassLoaderDataGraph::print_table_statistics(st);
2857 placeholders()->print_table_statistics(st, "Placeholder Table");
2858 constraints()->print_table_statistics(st, "LoaderConstraints Table");
2859 pd_cache_table()->print_table_statistics(st, "ProtectionDomainCache Table");
2860 }
2861 }
2862
2863 TableStatistics SystemDictionary::placeholders_statistics() {
2864 MutexLocker ml(SystemDictionary_lock);
2865 return placeholders()->statistics_calculate();
2866 }
2867
2868 TableStatistics SystemDictionary::loader_constraints_statistics() {
2869 MutexLocker ml(SystemDictionary_lock);
2870 return constraints()->statistics_calculate();
2871 }
2872
2873 TableStatistics SystemDictionary::protection_domain_cache_statistics() {
2874 MutexLocker ml(SystemDictionary_lock);
2875 return pd_cache_table()->statistics_calculate();
2876 }
2877
2878 // Utility for dumping dictionaries.
2879 SystemDictionaryDCmd::SystemDictionaryDCmd(outputStream* output, bool heap) :
2880 DCmdWithParser(output, heap),
2881 _verbose("-verbose", "Dump the content of each dictionary entry for all class loaders",
2882 "BOOLEAN", false, "false") {
2883 _dcmdparser.add_dcmd_option(&_verbose);
2884 }
2885
2886 void SystemDictionaryDCmd::execute(DCmdSource source, TRAPS) {
2887 VM_DumpHashtable dumper(output(), VM_DumpHashtable::DumpSysDict,
2888 _verbose.value());
2889 VMThread::execute(&dumper);
2890 }
2891
2892 int SystemDictionaryDCmd::num_arguments() {
2893 ResourceMark rm;
2894 SystemDictionaryDCmd* dcmd = new SystemDictionaryDCmd(NULL, false);
2895 if (dcmd != NULL) {
2896 DCmdMark mark(dcmd);
2897 return dcmd->_dcmdparser.num_arguments();
2898 } else {
2899 return 0;
2900 }
2901 }
--- EOF ---