1 /*
2 * Copyright (c) 1997, 2017, 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 "aot/aotLoader.hpp"
27 #include "classfile/classFileParser.hpp"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/classLoaderData.inline.hpp"
31 #include "classfile/classLoaderExt.hpp"
32 #include "classfile/dictionary.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/klassFactory.hpp"
35 #include "classfile/loaderConstraints.hpp"
36 #include "classfile/packageEntry.hpp"
37 #include "classfile/placeholders.hpp"
38 #include "classfile/resolutionErrors.hpp"
39 #include "classfile/stringTable.hpp"
40 #include "classfile/systemDictionary.hpp"
41 #include "classfile/vmSymbols.hpp"
42 #include "code/codeCache.hpp"
43 #include "compiler/compileBroker.hpp"
44 #include "gc/shared/gcLocker.hpp"
45 #include "gc/shared/gcTraceTime.inline.hpp"
46 #include "interpreter/bytecodeStream.hpp"
47 #include "interpreter/interpreter.hpp"
48 #include "logging/log.hpp"
49 #include "memory/filemap.hpp"
50 #include "memory/oopFactory.hpp"
51 #include "memory/resourceArea.hpp"
52 #include "oops/instanceKlass.hpp"
53 #include "oops/instanceRefKlass.hpp"
54 #include "oops/klass.inline.hpp"
55 #include "oops/methodData.hpp"
56 #include "oops/objArrayKlass.hpp"
57 #include "oops/objArrayOop.inline.hpp"
58 #include "oops/oop.inline.hpp"
59 #include "oops/symbol.hpp"
60 #include "oops/typeArrayKlass.hpp"
61 #include "prims/jvmtiEnvBase.hpp"
62 #include "prims/resolvedMethodTable.hpp"
63 #include "prims/methodHandles.hpp"
64 #include "runtime/arguments.hpp"
65 #include "runtime/biasedLocking.hpp"
66 #include "runtime/fieldType.hpp"
67 #include "runtime/handles.inline.hpp"
68 #include "runtime/java.hpp"
69 #include "runtime/javaCalls.hpp"
70 #include "runtime/mutexLocker.hpp"
71 #include "runtime/orderAccess.inline.hpp"
72 #include "runtime/signature.hpp"
73 #include "services/classLoadingService.hpp"
74 #include "services/threadService.hpp"
75 #include "trace/traceMacros.hpp"
76 #include "utilities/macros.hpp"
77 #include "utilities/ticks.hpp"
78 #if INCLUDE_CDS
79 #include "classfile/sharedClassUtil.hpp"
80 #include "classfile/systemDictionaryShared.hpp"
81 #endif
82 #if INCLUDE_JVMCI
83 #include "jvmci/jvmciRuntime.hpp"
84 #endif
85 #if INCLUDE_TRACE
86 #include "trace/tracing.hpp"
87 #endif
88
89 Dictionary* SystemDictionary::_dictionary = NULL;
90 PlaceholderTable* SystemDictionary::_placeholders = NULL;
91 Dictionary* SystemDictionary::_shared_dictionary = NULL;
92 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
93 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
94 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
95
96
97 int SystemDictionary::_number_of_modifications = 0;
98 int SystemDictionary::_sdgeneration = 0;
99 const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
100 20201,40423,99991};
101
102 oop SystemDictionary::_system_loader_lock_obj = NULL;
103
104 InstanceKlass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
105 = { NULL /*, NULL...*/ };
106
107 InstanceKlass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
108
109 oop SystemDictionary::_java_system_loader = NULL;
110
111 bool SystemDictionary::_has_loadClassInternal = false;
112 bool SystemDictionary::_has_checkPackageAccess = false;
113
114 // lazily initialized klass variables
115 InstanceKlass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
116
117
118 // ----------------------------------------------------------------------------
119 // Java-level SystemLoader
120
121 oop SystemDictionary::java_system_loader() {
122 return _java_system_loader;
123 }
124
125 void SystemDictionary::compute_java_system_loader(TRAPS) {
126 Klass* system_klass = WK_KLASS(ClassLoader_klass);
127 JavaValue result(T_OBJECT);
128 JavaCalls::call_static(&result,
129 WK_KLASS(ClassLoader_klass),
130 vmSymbols::getSystemClassLoader_name(),
131 vmSymbols::void_classloader_signature(),
132 CHECK);
133
134 _java_system_loader = (oop)result.get_jobject();
135
136 CDS_ONLY(SystemDictionaryShared::initialize(CHECK);)
137 }
138
139
140 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
141 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
142 return ClassLoaderDataGraph::find_or_create(class_loader, THREAD);
143 }
144
145 // ----------------------------------------------------------------------------
146 // Parallel class loading check
147
148 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
149 if (UnsyncloadClass || class_loader.is_null()) return true;
150 if (AlwaysLockClassLoader) return false;
151 return java_lang_ClassLoader::parallelCapable(class_loader());
152 }
153 // ----------------------------------------------------------------------------
154 // ParallelDefineClass flag does not apply to bootclass loader
155 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
156 if (class_loader.is_null()) return false;
157 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
158 return true;
159 }
160 return false;
161 }
162
163 // Returns true if the passed class loader is the builtin application class loader
164 // or a custom system class loader. A customer system class loader can be
165 // specified via -Djava.system.class.loader.
166 bool SystemDictionary::is_system_class_loader(oop class_loader) {
167 if (class_loader == NULL) {
168 return false;
169 }
170 return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass() ||
171 class_loader == _java_system_loader);
172 }
173
174 // Returns true if the passed class loader is the platform class loader.
175 bool SystemDictionary::is_platform_class_loader(oop class_loader) {
176 if (class_loader == NULL) {
177 return false;
178 }
179 return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass());
180 }
181
182 // ----------------------------------------------------------------------------
183 // Resolving of classes
184
185 // Forwards to resolve_or_null
186
187 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
188 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
189 if (HAS_PENDING_EXCEPTION || klass == NULL) {
190 // can return a null klass
191 klass = handle_resolution_exception(class_name, throw_error, klass, THREAD);
192 }
193 return klass;
194 }
195
196 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name,
197 bool throw_error,
198 Klass* klass, TRAPS) {
199 if (HAS_PENDING_EXCEPTION) {
200 // If we have a pending exception we forward it to the caller, unless throw_error is true,
201 // in which case we have to check whether the pending exception is a ClassNotFoundException,
202 // and if so convert it to a NoClassDefFoundError
203 // And chain the original ClassNotFoundException
204 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
205 ResourceMark rm(THREAD);
206 assert(klass == NULL, "Should not have result with exception pending");
207 Handle e(THREAD, PENDING_EXCEPTION);
208 CLEAR_PENDING_EXCEPTION;
209 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
210 } else {
211 return NULL;
212 }
213 }
214 // Class not found, throw appropriate error or exception depending on value of throw_error
215 if (klass == NULL) {
216 ResourceMark rm(THREAD);
217 if (throw_error) {
218 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
219 } else {
220 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
221 }
222 }
223 return klass;
224 }
225
226
227 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
228 bool throw_error, TRAPS)
229 {
230 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
231 }
232
233
234 // Forwards to resolve_instance_class_or_null
235
236 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
237 assert(THREAD->can_call_java(),
238 "can not load classes with compiler thread: class=%s, classloader=%s",
239 class_name->as_C_string(),
240 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string());
241 if (FieldType::is_array(class_name)) {
242 return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD);
243 } else if (FieldType::is_obj(class_name)) {
244 ResourceMark rm(THREAD);
245 // Ignore wrapping L and ;.
246 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
247 class_name->utf8_length() - 2, CHECK_NULL);
248 return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD);
249 } else {
250 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD);
251 }
252 }
253
254 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
255 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
256 }
257
258 // Forwards to resolve_instance_class_or_null
259
260 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
261 Handle class_loader,
262 Handle protection_domain,
263 TRAPS) {
264 assert(FieldType::is_array(class_name), "must be array");
265 Klass* k = NULL;
266 FieldArrayInfo fd;
267 // dimension and object_key in FieldArrayInfo are assigned as a side-effect
268 // of this call
269 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
270 if (t == T_OBJECT) {
271 // naked oop "k" is OK here -- we assign back into it
272 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
273 class_loader,
274 protection_domain,
275 CHECK_NULL);
276 if (k != NULL) {
277 k = k->array_klass(fd.dimension(), CHECK_NULL);
278 }
279 } else {
280 k = Universe::typeArrayKlassObj(t);
281 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
282 }
283 return k;
284 }
285
286
287 // Must be called for any super-class or super-interface resolution
288 // during class definition to allow class circularity checking
289 // super-interface callers:
290 // parse_interfaces - for defineClass & jvmtiRedefineClasses
291 // super-class callers:
292 // ClassFileParser - for defineClass & jvmtiRedefineClasses
293 // load_shared_class - while loading a class from shared archive
294 // resolve_instance_class_or_null:
295 // via: handle_parallel_super_load
296 // when resolving a class that has an existing placeholder with
297 // a saved superclass [i.e. a defineClass is currently in progress]
298 // if another thread is trying to resolve the class, it must do
299 // super-class checks on its own thread to catch class circularity
300 // This last call is critical in class circularity checking for cases
301 // where classloading is delegated to different threads and the
302 // classloader lock is released.
303 // Take the case: Base->Super->Base
304 // 1. If thread T1 tries to do a defineClass of class Base
305 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
306 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
307 // so it tries to load Super
308 // 3. If we load the class internally, or user classloader uses same thread
309 // loadClassFromxxx or defineClass via parseClassFile Super ...
310 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
311 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
312 // 3.4 calls resolve_super_or_fail Base
313 // 3.5 finds T1,Base -> throws class circularity
314 //OR 4. If T2 tries to resolve Super via defineClass Super ...
315 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
316 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
317 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
318 // 4.4 finds T2, Super -> throws class circularity
319 // Must be called, even if superclass is null, since this is
320 // where the placeholder entry is created which claims this
321 // thread is loading this class/classloader.
322 // Be careful when modifying this code: once you have run
323 // placeholders()->find_and_add(PlaceholderTable::LOAD_SUPER),
324 // you need to find_and_remove it before returning.
325 // So be careful to not exit with a CHECK_ macro betweeen these calls.
326 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
327 Symbol* class_name,
328 Handle class_loader,
329 Handle protection_domain,
330 bool is_superclass,
331 TRAPS) {
332 #if INCLUDE_CDS
333 if (DumpSharedSpaces) {
334 // Special processing for CDS dump time.
335 Klass* k = SystemDictionaryShared::dump_time_resolve_super_or_fail(child_name,
336 class_name, class_loader, protection_domain, is_superclass, CHECK_NULL);
337 if (k) {
338 return k;
339 }
340 }
341 #endif // INCLUDE_CDS
342
343 // Double-check, if child class is already loaded, just return super-class,interface
344 // Don't add a placedholder if already loaded, i.e. already in system dictionary
345 // Make sure there's a placeholder for the *child* before resolving.
346 // Used as a claim that this thread is currently loading superclass/classloader
347 // Used here for ClassCircularity checks and also for heap verification
348 // (every InstanceKlass in the heap needs to be in the system dictionary
349 // or have a placeholder).
350 // Must check ClassCircularity before checking if super class is already loaded
351 //
352 // We might not already have a placeholder if this child_name was
353 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
354 // the name of the class might not be known until the stream is actually
355 // parsed.
356 // Bugs 4643874, 4715493
357 // compute_hash can have a safepoint
358
359 ClassLoaderData* loader_data = class_loader_data(class_loader);
360 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
361 int d_index = dictionary()->hash_to_index(d_hash);
362 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
363 int p_index = placeholders()->hash_to_index(p_hash);
364 // can't throw error holding a lock
365 bool child_already_loaded = false;
366 bool throw_circularity_error = false;
367 {
368 MutexLocker mu(SystemDictionary_lock, THREAD);
369 Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
370 Klass* quicksuperk;
371 // to support // loading: if child done loading, just return superclass
372 // if class_name, & class_loader don't match:
373 // if initial define, SD update will give LinkageError
374 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
375 // so we don't throw an exception here.
376 // see: nsk redefclass014 & java.lang.instrument Instrument032
377 if ((childk != NULL ) && (is_superclass) &&
378 ((quicksuperk = childk->super()) != NULL) &&
379
380 ((quicksuperk->name() == class_name) &&
381 (quicksuperk->class_loader() == class_loader()))) {
382 return quicksuperk;
383 } else {
384 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
385 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
386 throw_circularity_error = true;
387 }
388 }
389 if (!throw_circularity_error) {
390 // Be careful not to exit resolve_super
391 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
392 }
393 }
394 if (throw_circularity_error) {
395 ResourceMark rm(THREAD);
396 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
397 }
398
399 // java.lang.Object should have been found above
400 assert(class_name != NULL, "null super class for resolving");
401 // Resolve the super class or interface, check results on return
402 Klass* superk = SystemDictionary::resolve_or_null(class_name,
403 class_loader,
404 protection_domain,
405 THREAD);
406
407 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
408 // It is no longer necessary to keep the placeholder table alive until update_dictionary
409 // or error. GC used to walk the placeholder table as strong roots.
410 // The instanceKlass is kept alive because the class loader is on the stack,
411 // which keeps the loader_data alive, as well as all instanceKlasses in
412 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
413 {
414 MutexLocker mu(SystemDictionary_lock, THREAD);
415 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
416 SystemDictionary_lock->notify_all();
417 }
418 if (HAS_PENDING_EXCEPTION || superk == NULL) {
419 // can null superk
420 superk = handle_resolution_exception(class_name, true, superk, THREAD);
421 }
422
423 return superk;
424 }
425
426 void SystemDictionary::validate_protection_domain(InstanceKlass* klass,
427 Handle class_loader,
428 Handle protection_domain,
429 TRAPS) {
430 if(!has_checkPackageAccess()) return;
431
432 // Now we have to call back to java to check if the initating class has access
433 JavaValue result(T_VOID);
434 if (log_is_enabled(Debug, protectiondomain)) {
435 ResourceMark rm;
436 // Print out trace information
437 outputStream* log = Log(protectiondomain)::debug_stream();
438 log->print_cr("Checking package access");
439 log->print("class loader: "); class_loader()->print_value_on(log);
440 log->print(" protection domain: "); protection_domain()->print_value_on(log);
441 log->print(" loading: "); klass->print_value_on(log);
442 log->cr();
443 }
444
445 InstanceKlass* system_loader = SystemDictionary::ClassLoader_klass();
446 JavaCalls::call_special(&result,
447 class_loader,
448 system_loader,
449 vmSymbols::checkPackageAccess_name(),
450 vmSymbols::class_protectiondomain_signature(),
451 Handle(THREAD, klass->java_mirror()),
452 protection_domain,
453 THREAD);
454
455 if (HAS_PENDING_EXCEPTION) {
456 log_debug(protectiondomain)("DENIED !!!!!!!!!!!!!!!!!!!!!");
457 } else {
458 log_debug(protectiondomain)("granted");
459 }
460
461 if (HAS_PENDING_EXCEPTION) return;
462
463 // If no exception has been thrown, we have validated the protection domain
464 // Insert the protection domain of the initiating class into the set.
465 {
466 // We recalculate the entry here -- we've called out to java since
467 // the last time it was calculated.
468 ClassLoaderData* loader_data = class_loader_data(class_loader);
469
470 Symbol* kn = klass->name();
471 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
472 int d_index = dictionary()->hash_to_index(d_hash);
473
474 MutexLocker mu(SystemDictionary_lock, THREAD);
475 {
476 // Note that we have an entry, and entries can be deleted only during GC,
477 // so we cannot allow GC to occur while we're holding this entry.
478
479 // We're using a NoSafepointVerifier to catch any place where we
480 // might potentially do a GC at all.
481 // Dictionary::do_unloading() asserts that classes in SD are only
482 // unloaded at a safepoint. Anonymous classes are not in SD.
483 NoSafepointVerifier nosafepoint;
484 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
485 protection_domain, THREAD);
486 }
487 }
488 }
489
490 // We only get here if this thread finds that another thread
491 // has already claimed the placeholder token for the current operation,
492 // but that other thread either never owned or gave up the
493 // object lock
494 // Waits on SystemDictionary_lock to indicate placeholder table updated
495 // On return, caller must recheck placeholder table state
496 //
497 // We only get here if
498 // 1) custom classLoader, i.e. not bootstrap classloader
499 // 2) UnsyncloadClass not set
500 // 3) custom classLoader has broken the class loader objectLock
501 // so another thread got here in parallel
502 //
503 // lockObject must be held.
504 // Complicated dance due to lock ordering:
505 // Must first release the classloader object lock to
506 // allow initial definer to complete the class definition
507 // and to avoid deadlock
508 // Reclaim classloader lock object with same original recursion count
509 // Must release SystemDictionary_lock after notify, since
510 // class loader lock must be claimed before SystemDictionary_lock
511 // to prevent deadlocks
512 //
513 // The notify allows applications that did an untimed wait() on
514 // the classloader object lock to not hang.
515 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
516 assert_lock_strong(SystemDictionary_lock);
517
518 bool calledholdinglock
519 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
520 assert(calledholdinglock,"must hold lock for notify");
521 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
522 ObjectSynchronizer::notifyall(lockObject, THREAD);
523 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
524 SystemDictionary_lock->wait();
525 SystemDictionary_lock->unlock();
526 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
527 SystemDictionary_lock->lock();
528 }
529
530 // If the class in is in the placeholder table, class loading is in progress
531 // For cases where the application changes threads to load classes, it
532 // is critical to ClassCircularity detection that we try loading
533 // the superclass on the same thread internally, so we do parallel
534 // super class loading here.
535 // This also is critical in cases where the original thread gets stalled
536 // even in non-circularity situations.
537 // Note: must call resolve_super_or_fail even if null super -
538 // to force placeholder entry creation for this class for circularity detection
539 // Caller must check for pending exception
540 // Returns non-null Klass* if other thread has completed load
541 // and we are done,
542 // If return null Klass* and no pending exception, the caller must load the class
543 InstanceKlass* SystemDictionary::handle_parallel_super_load(
544 Symbol* name, Symbol* superclassname, Handle class_loader,
545 Handle protection_domain, Handle lockObject, TRAPS) {
546
547 ClassLoaderData* loader_data = class_loader_data(class_loader);
548 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
549 int d_index = dictionary()->hash_to_index(d_hash);
550 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
551 int p_index = placeholders()->hash_to_index(p_hash);
552
553 // superk is not used, resolve_super called for circularity check only
554 // This code is reached in two situations. One if this thread
555 // is loading the same class twice (e.g. ClassCircularity, or
556 // java.lang.instrument).
557 // The second is if another thread started the resolve_super first
558 // and has not yet finished.
559 // In both cases the original caller will clean up the placeholder
560 // entry on error.
561 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
562 superclassname,
563 class_loader,
564 protection_domain,
565 true,
566 CHECK_NULL);
567
568 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
569 // Serial class loaders and bootstrap classloader do wait for superclass loads
570 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
571 MutexLocker mu(SystemDictionary_lock, THREAD);
572 // Check if classloading completed while we were loading superclass or waiting
573 return find_class(d_index, d_hash, name, loader_data);
574 }
575
576 // must loop to both handle other placeholder updates
577 // and spurious notifications
578 bool super_load_in_progress = true;
579 PlaceholderEntry* placeholder;
580 while (super_load_in_progress) {
581 MutexLocker mu(SystemDictionary_lock, THREAD);
582 // Check if classloading completed while we were loading superclass or waiting
583 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
584 if (check != NULL) {
585 // Klass is already loaded, so just return it
586 return check;
587 } else {
588 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
589 if (placeholder && placeholder->super_load_in_progress() ){
590 // Before UnsyncloadClass:
591 // We only get here if the application has released the
592 // classloader lock when another thread was in the middle of loading a
593 // superclass/superinterface for this class, and now
594 // this thread is also trying to load this class.
595 // To minimize surprises, the first thread that started to
596 // load a class should be the one to complete the loading
597 // with the classfile it initially expected.
598 // This logic has the current thread wait once it has done
599 // all the superclass/superinterface loading it can, until
600 // the original thread completes the class loading or fails
601 // If it completes we will use the resulting InstanceKlass
602 // which we will find below in the systemDictionary.
603 // We also get here for parallel bootstrap classloader
604 if (class_loader.is_null()) {
605 SystemDictionary_lock->wait();
606 } else {
607 double_lock_wait(lockObject, THREAD);
608 }
609 } else {
610 // If not in SD and not in PH, other thread's load must have failed
611 super_load_in_progress = false;
612 }
613 }
614 }
615 return NULL;
616 }
617
618 static void post_class_load_event(const Ticks& start_time,
619 InstanceKlass* k,
620 const ClassLoaderData* init_cld) {
621 #if INCLUDE_TRACE
622 EventClassLoad event(UNTIMED);
623 if (event.should_commit()) {
624 event.set_starttime(start_time);
625 event.set_loadedClass(k);
626 event.set_definingClassLoader(k->class_loader_data());
627 event.set_initiatingClassLoader(init_cld);
628 event.commit();
629 }
630 #endif // INCLUDE_TRACE
631 }
632
633 static void class_define_event(InstanceKlass* k,
634 const ClassLoaderData* def_cld) {
635 #if INCLUDE_TRACE
636 EventClassDefine event;
637 if (event.should_commit()) {
638 event.set_definedClass(k);
639 event.set_definingClassLoader(def_cld);
640 event.commit();
641 }
642 #endif // INCLUDE_TRACE
643 }
644
645 // Be careful when modifying this code: once you have run
646 // placeholders()->find_and_add(PlaceholderTable::LOAD_INSTANCE),
647 // you need to find_and_remove it before returning.
648 // So be careful to not exit with a CHECK_ macro betweeen these calls.
649 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
650 Handle class_loader,
651 Handle protection_domain,
652 TRAPS) {
653 assert(name != NULL && !FieldType::is_array(name) &&
654 !FieldType::is_obj(name), "invalid class name");
655
656 Ticks class_load_start_time = Ticks::now();
657
658 HandleMark hm(THREAD);
659
660 // Fix for 4474172; see evaluation for more details
661 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
662 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
663
664 // Do lookup to see if class already exist and the protection domain
665 // has the right access
666 // This call uses find which checks protection domain already matches
667 // All subsequent calls use find_class, and set has_loaded_class so that
668 // before we return a result we call out to java to check for valid protection domain
669 // to allow returning the Klass* and add it to the pd_set if it is valid
670 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
671 int d_index = dictionary()->hash_to_index(d_hash);
672 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
673 protection_domain, THREAD);
674 if (probe != NULL) return probe;
675
676
677 // Non-bootstrap class loaders will call out to class loader and
678 // define via jvm/jni_DefineClass which will acquire the
679 // class loader object lock to protect against multiple threads
680 // defining the class in parallel by accident.
681 // This lock must be acquired here so the waiter will find
682 // any successful result in the SystemDictionary and not attempt
683 // the define
684 // ParallelCapable Classloaders and the bootstrap classloader,
685 // or all classloaders with UnsyncloadClass do not acquire lock here
686 bool DoObjectLock = true;
687 if (is_parallelCapable(class_loader)) {
688 DoObjectLock = false;
689 }
690
691 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
692 int p_index = placeholders()->hash_to_index(p_hash);
693
694 // Class is not in SystemDictionary so we have to do loading.
695 // Make sure we are synchronized on the class loader before we proceed
696 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
697 check_loader_lock_contention(lockObject, THREAD);
698 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
699
700 // Check again (after locking) if class already exist in SystemDictionary
701 bool class_has_been_loaded = false;
702 bool super_load_in_progress = false;
703 bool havesupername = false;
704 InstanceKlass* k = NULL;
705 PlaceholderEntry* placeholder;
706 Symbol* superclassname = NULL;
707
708 {
709 MutexLocker mu(SystemDictionary_lock, THREAD);
710 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
711 if (check != NULL) {
712 // Klass is already loaded, so just return it
713 class_has_been_loaded = true;
714 k = check;
715 } else {
716 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
717 if (placeholder && placeholder->super_load_in_progress()) {
718 super_load_in_progress = true;
719 if (placeholder->havesupername() == true) {
720 superclassname = placeholder->supername();
721 havesupername = true;
722 }
723 }
724 }
725 }
726
727 // If the class is in the placeholder table, class loading is in progress
728 if (super_load_in_progress && havesupername==true) {
729 k = handle_parallel_super_load(name,
730 superclassname,
731 class_loader,
732 protection_domain,
733 lockObject, THREAD);
734 if (HAS_PENDING_EXCEPTION) {
735 return NULL;
736 }
737 if (k != NULL) {
738 class_has_been_loaded = true;
739 }
740 }
741
742 bool throw_circularity_error = false;
743 if (!class_has_been_loaded) {
744 bool load_instance_added = false;
745
746 // add placeholder entry to record loading instance class
747 // Five cases:
748 // All cases need to prevent modifying bootclasssearchpath
749 // in parallel with a classload of same classname
750 // Redefineclasses uses existence of the placeholder for the duration
751 // of the class load to prevent concurrent redefinition of not completely
752 // defined classes.
753 // case 1. traditional classloaders that rely on the classloader object lock
754 // - no other need for LOAD_INSTANCE
755 // case 2. traditional classloaders that break the classloader object lock
756 // as a deadlock workaround. Detection of this case requires that
757 // this check is done while holding the classloader object lock,
758 // and that lock is still held when calling classloader's loadClass.
759 // For these classloaders, we ensure that the first requestor
760 // completes the load and other requestors wait for completion.
761 // case 3. UnsyncloadClass - don't use objectLocker
762 // With this flag, we allow parallel classloading of a
763 // class/classloader pair
764 // case4. Bootstrap classloader - don't own objectLocker
765 // This classloader supports parallelism at the classloader level,
766 // but only allows a single load of a class/classloader pair.
767 // No performance benefit and no deadlock issues.
768 // case 5. parallelCapable user level classloaders - without objectLocker
769 // Allow parallel classloading of a class/classloader pair
770
771 {
772 MutexLocker mu(SystemDictionary_lock, THREAD);
773 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
774 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
775 if (oldprobe) {
776 // only need check_seen_thread once, not on each loop
777 // 6341374 java/lang/Instrument with -Xcomp
778 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
779 throw_circularity_error = true;
780 } else {
781 // case 1: traditional: should never see load_in_progress.
782 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
783
784 // case 4: bootstrap classloader: prevent futile classloading,
785 // wait on first requestor
786 if (class_loader.is_null()) {
787 SystemDictionary_lock->wait();
788 } else {
789 // case 2: traditional with broken classloader lock. wait on first
790 // requestor.
791 double_lock_wait(lockObject, THREAD);
792 }
793 // Check if classloading completed while we were waiting
794 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
795 if (check != NULL) {
796 // Klass is already loaded, so just return it
797 k = check;
798 class_has_been_loaded = true;
799 }
800 // check if other thread failed to load and cleaned up
801 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
802 }
803 }
804 }
805 }
806 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
807 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
808 // LOAD_INSTANCE in parallel
809
810 if (!throw_circularity_error && !class_has_been_loaded) {
811 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
812 load_instance_added = true;
813 // For class loaders that do not acquire the classloader object lock,
814 // if they did not catch another thread holding LOAD_INSTANCE,
815 // need a check analogous to the acquire ObjectLocker/find_class
816 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
817 // one final check if the load has already completed
818 // class loaders holding the ObjectLock shouldn't find the class here
819 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
820 if (check != NULL) {
821 // Klass is already loaded, so return it after checking/adding protection domain
822 k = check;
823 class_has_been_loaded = true;
824 }
825 }
826 }
827
828 // must throw error outside of owning lock
829 if (throw_circularity_error) {
830 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
831 ResourceMark rm(THREAD);
832 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
833 }
834
835 if (!class_has_been_loaded) {
836
837 // Do actual loading
838 k = load_instance_class(name, class_loader, THREAD);
839
840 // For UnsyncloadClass only
841 // If they got a linkageError, check if a parallel class load succeeded.
842 // If it did, then for bytecode resolution the specification requires
843 // that we return the same result we did for the other thread, i.e. the
844 // successfully loaded InstanceKlass
845 // Should not get here for classloaders that support parallelism
846 // with the new cleaner mechanism, even with AllowParallelDefineClass
847 // Bootstrap goes through here to allow for an extra guarantee check
848 if (UnsyncloadClass || (class_loader.is_null())) {
849 if (k == NULL && HAS_PENDING_EXCEPTION
850 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
851 MutexLocker mu(SystemDictionary_lock, THREAD);
852 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
853 if (check != NULL) {
854 // Klass is already loaded, so just use it
855 k = check;
856 CLEAR_PENDING_EXCEPTION;
857 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
858 }
859 }
860 }
861
862 // If everything was OK (no exceptions, no null return value), and
863 // class_loader is NOT the defining loader, do a little more bookkeeping.
864 if (!HAS_PENDING_EXCEPTION && k != NULL &&
865 k->class_loader() != class_loader()) {
866
867 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
868
869 // Need to check for a PENDING_EXCEPTION again; check_constraints
870 // can throw and doesn't use the CHECK macro.
871 if (!HAS_PENDING_EXCEPTION) {
872 { // Grabbing the Compile_lock prevents systemDictionary updates
873 // during compilations.
874 MutexLocker mu(Compile_lock, THREAD);
875 update_dictionary(d_index, d_hash, p_index, p_hash,
876 k, class_loader, THREAD);
877 }
878
879 if (JvmtiExport::should_post_class_load()) {
880 Thread *thread = THREAD;
881 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
882 JvmtiExport::post_class_load((JavaThread *) thread, k);
883 }
884 }
885 }
886 } // load_instance_class loop
887
888 if (load_instance_added == true) {
889 // clean up placeholder entries for LOAD_INSTANCE success or error
890 // This brackets the SystemDictionary updates for both defining
891 // and initiating loaders
892 MutexLocker mu(SystemDictionary_lock, THREAD);
893 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
894 SystemDictionary_lock->notify_all();
895 }
896 }
897
898 if (HAS_PENDING_EXCEPTION || k == NULL) {
899 return NULL;
900 }
901
902 post_class_load_event(class_load_start_time, k, loader_data);
903
904 #ifdef ASSERT
905 {
906 ClassLoaderData* loader_data = k->class_loader_data();
907 MutexLocker mu(SystemDictionary_lock, THREAD);
908 Klass* kk = find_class(name, loader_data);
909 assert(kk == k, "should be present in dictionary");
910 }
911 #endif
912
913 // return if the protection domain in NULL
914 if (protection_domain() == NULL) return k;
915
916 // Check the protection domain has the right access
917 {
918 MutexLocker mu(SystemDictionary_lock, THREAD);
919 // Note that we have an entry, and entries can be deleted only during GC,
920 // so we cannot allow GC to occur while we're holding this entry.
921 // We're using a NoSafepointVerifier to catch any place where we
922 // might potentially do a GC at all.
923 // Dictionary::do_unloading() asserts that classes in SD are only
924 // unloaded at a safepoint. Anonymous classes are not in SD.
925 NoSafepointVerifier nosafepoint;
926 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
927 loader_data,
928 protection_domain)) {
929 return k;
930 }
931 }
932
933 // Verify protection domain. If it fails an exception is thrown
934 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
935
936 return k;
937 }
938
939
940 // This routine does not lock the system dictionary.
941 //
942 // Since readers don't hold a lock, we must make sure that system
943 // dictionary entries are only removed at a safepoint (when only one
944 // thread is running), and are added to in a safe way (all links must
945 // be updated in an MT-safe manner).
946 //
947 // Callers should be aware that an entry could be added just after
948 // _dictionary->bucket(index) is read here, so the caller will not see
949 // the new entry.
950
951 Klass* SystemDictionary::find(Symbol* class_name,
952 Handle class_loader,
953 Handle protection_domain,
954 TRAPS) {
955
956 // The result of this call should be consistent with the result
957 // of the call to resolve_instance_class_or_null().
958 // See evaluation 6790209 and 4474172 for more details.
959 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
960 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
961
962 if (loader_data == NULL) {
963 // If the ClassLoaderData has not been setup,
964 // then the class loader has no entries in the dictionary.
965 return NULL;
966 }
967
968 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
969 int d_index = dictionary()->hash_to_index(d_hash);
970
971 {
972 // Note that we have an entry, and entries can be deleted only during GC,
973 // so we cannot allow GC to occur while we're holding this entry.
974 // We're using a NoSafepointVerifier to catch any place where we
975 // might potentially do a GC at all.
976 // Dictionary::do_unloading() asserts that classes in SD are only
977 // unloaded at a safepoint. Anonymous classes are not in SD.
978 NoSafepointVerifier nosafepoint;
979 return dictionary()->find(d_index, d_hash, class_name, loader_data,
980 protection_domain, THREAD);
981 }
982 }
983
984
985 // Look for a loaded instance or array klass by name. Do not do any loading.
986 // return NULL in case of error.
987 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
988 Handle class_loader,
989 Handle protection_domain,
990 TRAPS) {
991 Klass* k = NULL;
992 assert(class_name != NULL, "class name must be non NULL");
993
994 if (FieldType::is_array(class_name)) {
995 // The name refers to an array. Parse the name.
996 // dimension and object_key in FieldArrayInfo are assigned as a
997 // side-effect of this call
998 FieldArrayInfo fd;
999 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
1000 if (t != T_OBJECT) {
1001 k = Universe::typeArrayKlassObj(t);
1002 } else {
1003 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
1004 }
1005 if (k != NULL) {
1006 k = k->array_klass_or_null(fd.dimension());
1007 }
1008 } else {
1009 k = find(class_name, class_loader, protection_domain, THREAD);
1010 }
1011 return k;
1012 }
1013
1014 // Note: this method is much like resolve_from_stream, but
1015 // does not publish the classes via the SystemDictionary.
1016 // Handles unsafe_DefineAnonymousClass and redefineclasses
1017 // RedefinedClasses do not add to the class hierarchy
1018 InstanceKlass* SystemDictionary::parse_stream(Symbol* class_name,
1019 Handle class_loader,
1020 Handle protection_domain,
1021 ClassFileStream* st,
1022 const InstanceKlass* host_klass,
1023 GrowableArray<Handle>* cp_patches,
1024 TRAPS) {
1025
1026 Ticks class_load_start_time = Ticks::now();
1027
1028 ClassLoaderData* loader_data;
1029 if (host_klass != NULL) {
1030 // Create a new CLD for anonymous class, that uses the same class loader
1031 // as the host_klass
1032 guarantee(host_klass->class_loader() == class_loader(), "should be the same");
1033 guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping");
1034 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
1035 loader_data->record_dependency(host_klass, CHECK_NULL);
1036 } else {
1037 loader_data = ClassLoaderData::class_loader_data(class_loader());
1038 }
1039
1040 assert(st != NULL, "invariant");
1041 assert(st->need_verify(), "invariant");
1042
1043 // Parse stream and create a klass.
1044 // Note that we do this even though this klass might
1045 // already be present in the SystemDictionary, otherwise we would not
1046 // throw potential ClassFormatErrors.
1047
1048 InstanceKlass* k = KlassFactory::create_from_stream(st,
1049 class_name,
1050 loader_data,
1051 protection_domain,
1052 host_klass,
1053 cp_patches,
1054 CHECK_NULL);
1055
1056 if (host_klass != NULL && k != NULL) {
1057 // If it's anonymous, initialize it now, since nobody else will.
1058
1059 {
1060 MutexLocker mu_r(Compile_lock, THREAD);
1061
1062 // Add to class hierarchy, initialize vtables, and do possible
1063 // deoptimizations.
1064 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1065
1066 // But, do not add to system dictionary.
1067
1068 // compiled code dependencies need to be validated anyway
1069 notice_modification();
1070 }
1071
1072 // Rewrite and patch constant pool here.
1073 k->link_class(CHECK_NULL);
1074 if (cp_patches != NULL) {
1075 k->constants()->patch_resolved_references(cp_patches);
1076 }
1077 k->eager_initialize(CHECK_NULL);
1078
1079 // notify jvmti
1080 if (JvmtiExport::should_post_class_load()) {
1081 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1082 JvmtiExport::post_class_load((JavaThread *) THREAD, k);
1083 }
1084
1085 post_class_load_event(class_load_start_time, k, loader_data);
1086 }
1087 assert(host_klass != NULL || NULL == cp_patches,
1088 "cp_patches only found with host_klass");
1089
1090 return k;
1091 }
1092
1093 // Add a klass to the system from a stream (called by jni_DefineClass and
1094 // JVM_DefineClass).
1095 // Note: class_name can be NULL. In that case we do not know the name of
1096 // the class until we have parsed the stream.
1097
1098 InstanceKlass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1099 Handle class_loader,
1100 Handle protection_domain,
1101 ClassFileStream* st,
1102 TRAPS) {
1103
1104 HandleMark hm(THREAD);
1105
1106 // Classloaders that support parallelism, e.g. bootstrap classloader,
1107 // or all classloaders with UnsyncloadClass do not acquire lock here
1108 bool DoObjectLock = true;
1109 if (is_parallelCapable(class_loader)) {
1110 DoObjectLock = false;
1111 }
1112
1113 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
1114
1115 // Make sure we are synchronized on the class loader before we proceed
1116 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1117 check_loader_lock_contention(lockObject, THREAD);
1118 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1119
1120 assert(st != NULL, "invariant");
1121
1122 // Parse the stream and create a klass.
1123 // Note that we do this even though this klass might
1124 // already be present in the SystemDictionary, otherwise we would not
1125 // throw potential ClassFormatErrors.
1126 InstanceKlass* k = NULL;
1127
1128 #if INCLUDE_CDS
1129 k = SystemDictionaryShared::lookup_from_stream(class_name,
1130 class_loader,
1131 protection_domain,
1132 st,
1133 CHECK_NULL);
1134 #endif
1135
1136 if (k == NULL) {
1137 if (st->buffer() == NULL) {
1138 return NULL;
1139 }
1140 k = KlassFactory::create_from_stream(st,
1141 class_name,
1142 loader_data,
1143 protection_domain,
1144 NULL, // host_klass
1145 NULL, // cp_patches
1146 CHECK_NULL);
1147 }
1148
1149 assert(k != NULL, "no klass created");
1150 Symbol* h_name = k->name();
1151 assert(class_name == NULL || class_name == h_name, "name mismatch");
1152
1153 // Add class just loaded
1154 // If a class loader supports parallel classloading handle parallel define requests
1155 // find_or_define_instance_class may return a different InstanceKlass
1156 if (is_parallelCapable(class_loader)) {
1157 InstanceKlass* defined_k = find_or_define_instance_class(h_name, class_loader, k, THREAD);
1158 if (!HAS_PENDING_EXCEPTION && defined_k != k) {
1159 // If a parallel capable class loader already defined this class, register 'k' for cleanup.
1160 assert(defined_k != NULL, "Should have a klass if there's no exception");
1161 loader_data->add_to_deallocate_list(k);
1162 k = defined_k;
1163 }
1164 } else {
1165 define_instance_class(k, THREAD);
1166 }
1167
1168 // If defining the class throws an exception register 'k' for cleanup.
1169 if (HAS_PENDING_EXCEPTION) {
1170 assert(k != NULL, "Must have an instance klass here!");
1171 loader_data->add_to_deallocate_list(k);
1172 return NULL;
1173 }
1174
1175 // Make sure we have an entry in the SystemDictionary on success
1176 debug_only( {
1177 MutexLocker mu(SystemDictionary_lock, THREAD);
1178
1179 Klass* check = find_class(h_name, k->class_loader_data());
1180 assert(check == k, "should be present in the dictionary");
1181 } );
1182
1183 return k;
1184 }
1185
1186 #if INCLUDE_CDS
1187 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
1188 int number_of_entries) {
1189 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
1190 "bad shared dictionary size.");
1191 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1192 }
1193
1194
1195 // If there is a shared dictionary, then find the entry for the
1196 // given shared system class, if any.
1197
1198 InstanceKlass* SystemDictionary::find_shared_class(Symbol* class_name) {
1199 if (shared_dictionary() != NULL) {
1200 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
1201 int d_index = shared_dictionary()->hash_to_index(d_hash);
1202
1203 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1204 } else {
1205 return NULL;
1206 }
1207 }
1208
1209
1210 // Load a class from the shared spaces (found through the shared system
1211 // dictionary). Force the superclass and all interfaces to be loaded.
1212 // Update the class definition to include sibling classes and no
1213 // subclasses (yet). [Classes in the shared space are not part of the
1214 // object hierarchy until loaded.]
1215
1216 InstanceKlass* SystemDictionary::load_shared_class(
1217 Symbol* class_name, Handle class_loader, TRAPS) {
1218 InstanceKlass* ik = find_shared_class(class_name);
1219 // Make sure we only return the boot class for the NULL classloader.
1220 if (ik != NULL &&
1221 ik->is_shared_boot_class() && class_loader.is_null()) {
1222 Handle protection_domain;
1223 return load_shared_class(ik, class_loader, protection_domain, THREAD);
1224 }
1225 return NULL;
1226 }
1227
1228 // Check if a shared class can be loaded by the specific classloader:
1229 //
1230 // NULL classloader:
1231 // - Module class from "modules" jimage. ModuleEntry must be defined in the classloader.
1232 // - Class from -Xbootclasspath/a. The class has no defined PackageEntry, or must
1233 // be defined in an unnamed module.
1234 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
1235 InstanceKlass* ik,
1236 Handle class_loader, TRAPS) {
1237 assert(!ModuleEntryTable::javabase_moduleEntry()->is_patched(),
1238 "Cannot use sharing if java.base is patched");
1239 ResourceMark rm;
1240 int path_index = ik->shared_classpath_index();
1241 SharedClassPathEntry* ent =
1242 (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
1243 if (!Universe::is_module_initialized()) {
1244 assert(ent != NULL && ent->is_jrt(),
1245 "Loading non-bootstrap classes before the module system is initialized");
1246 assert(class_loader.is_null(), "sanity");
1247 return true;
1248 }
1249 // Get the pkg_entry from the classloader
1250 TempNewSymbol pkg_name = NULL;
1251 PackageEntry* pkg_entry = NULL;
1252 ModuleEntry* mod_entry = NULL;
1253 const char* pkg_string = NULL;
1254 ClassLoaderData* loader_data = class_loader_data(class_loader);
1255 pkg_name = InstanceKlass::package_from_name(class_name, CHECK_false);
1256 if (pkg_name != NULL) {
1257 pkg_string = pkg_name->as_C_string();
1258 if (loader_data != NULL) {
1259 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1260 }
1261 if (pkg_entry != NULL) {
1262 mod_entry = pkg_entry->module();
1263 }
1264 }
1265
1266 // If the archived class is from a module that has been patched at runtime,
1267 // the class cannot be loaded from the archive.
1268 if (mod_entry != NULL && mod_entry->is_patched()) {
1269 return false;
1270 }
1271
1272 if (class_loader.is_null()) {
1273 assert(ent != NULL, "Shared class for NULL classloader must have valid SharedClassPathEntry");
1274 // The NULL classloader can load archived class originated from the
1275 // "modules" jimage and the -Xbootclasspath/a. For class from the
1276 // "modules" jimage, the PackageEntry/ModuleEntry must be defined
1277 // by the NULL classloader.
1278 if (mod_entry != NULL) {
1279 // PackageEntry/ModuleEntry is found in the classloader. Check if the
1280 // ModuleEntry's location agrees with the archived class' origination.
1281 if (ent->is_jrt() && mod_entry->location()->starts_with("jrt:")) {
1282 return true; // Module class from the "module" jimage
1283 }
1284 }
1285
1286 // If the archived class is not from the "module" jimage, the class can be
1287 // loaded by the NULL classloader if
1288 //
1289 // 1. the class is from the unamed package
1290 // 2. or, the class is not from a module defined in the NULL classloader
1291 // 3. or, the class is from an unamed module
1292 if (!ent->is_jrt() && ik->is_shared_boot_class()) {
1293 // the class is from the -Xbootclasspath/a
1294 if (pkg_string == NULL ||
1295 pkg_entry == NULL ||
1296 pkg_entry->in_unnamed_module()) {
1297 assert(mod_entry == NULL ||
1298 mod_entry == loader_data->unnamed_module(),
1299 "the unnamed module is not defined in the classloader");
1300 return true;
1301 }
1302 }
1303 return false;
1304 } else {
1305 bool res = SystemDictionaryShared::is_shared_class_visible_for_classloader(
1306 ik, class_loader, pkg_string, pkg_name,
1307 pkg_entry, mod_entry, CHECK_(false));
1308 return res;
1309 }
1310 }
1311
1312 InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
1313 Handle class_loader,
1314 Handle protection_domain, TRAPS) {
1315
1316 if (ik != NULL) {
1317 Symbol* class_name = ik->name();
1318
1319 bool visible = is_shared_class_visible(
1320 class_name, ik, class_loader, CHECK_NULL);
1321 if (!visible) {
1322 return NULL;
1323 }
1324
1325 // Resolve the superclass and interfaces. They must be the same
1326 // as in dump time, because the layout of <ik> depends on
1327 // the specific layout of ik->super() and ik->local_interfaces().
1328 //
1329 // If unexpected superclass or interfaces are found, we cannot
1330 // load <ik> from the shared archive.
1331
1332 if (ik->super() != NULL) {
1333 Symbol* cn = ik->super()->name();
1334 Klass *s = resolve_super_or_fail(class_name, cn,
1335 class_loader, protection_domain, true, CHECK_NULL);
1336 if (s != ik->super()) {
1337 // The dynamically resolved super class is not the same as the one we used during dump time,
1338 // so we cannot use ik.
1339 return NULL;
1340 } else {
1341 assert(s->is_shared(), "must be");
1342 }
1343 }
1344
1345 Array<Klass*>* interfaces = ik->local_interfaces();
1346 int num_interfaces = interfaces->length();
1347 for (int index = 0; index < num_interfaces; index++) {
1348 Klass* k = interfaces->at(index);
1349 Symbol* name = k->name();
1350 Klass* i = resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_NULL);
1351 if (k != i) {
1352 // The dynamically resolved interface class is not the same as the one we used during dump time,
1353 // so we cannot use ik.
1354 return NULL;
1355 } else {
1356 assert(i->is_shared(), "must be");
1357 }
1358 }
1359
1360 InstanceKlass* new_ik = KlassFactory::check_shared_class_file_load_hook(
1361 ik, class_name, class_loader, protection_domain, CHECK_NULL);
1362 if (new_ik != NULL) {
1363 // The class is changed by CFLH. Return the new class. The shared class is
1364 // not used.
1365 return new_ik;
1366 }
1367
1368 // Adjust methods to recover missing data. They need addresses for
1369 // interpreter entry points and their default native method address
1370 // must be reset.
1371
1372 // Updating methods must be done under a lock so multiple
1373 // threads don't update these in parallel
1374 //
1375 // Shared classes are all currently loaded by either the bootstrap or
1376 // internal parallel class loaders, so this will never cause a deadlock
1377 // on a custom class loader lock.
1378
1379 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1380 {
1381 HandleMark hm(THREAD);
1382 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1383 check_loader_lock_contention(lockObject, THREAD);
1384 ObjectLocker ol(lockObject, THREAD, true);
1385 // prohibited package check assumes all classes loaded from archive call
1386 // restore_unshareable_info which calls ik->set_package()
1387 ik->restore_unshareable_info(loader_data, protection_domain, CHECK_NULL);
1388 }
1389
1390 ik->print_class_load_logging(loader_data, NULL, NULL);
1391
1392 // For boot loader, ensure that GetSystemPackage knows that a class in this
1393 // package was loaded.
1394 if (class_loader.is_null()) {
1395 int path_index = ik->shared_classpath_index();
1396 ResourceMark rm;
1397 ClassLoader::add_package(ik->name()->as_C_string(), path_index, THREAD);
1398 }
1399
1400 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1401 // Only dump the classes that can be stored into CDS archive
1402 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1403 ResourceMark rm(THREAD);
1404 classlist_file->print_cr("%s", ik->name()->as_C_string());
1405 classlist_file->flush();
1406 }
1407 }
1408
1409 // notify a class loaded from shared object
1410 ClassLoadingService::notify_class_loaded(ik, true /* shared class */);
1411 }
1412
1413 ik->set_has_passed_fingerprint_check(false);
1414 if (UseAOT && ik->supers_have_passed_fingerprint_checks()) {
1415 uint64_t aot_fp = AOTLoader::get_saved_fingerprint(ik);
1416 uint64_t cds_fp = ik->get_stored_fingerprint();
1417 if (aot_fp != 0 && aot_fp == cds_fp) {
1418 // This class matches with a class saved in an AOT library
1419 ik->set_has_passed_fingerprint_check(true);
1420 } else {
1421 ResourceMark rm;
1422 log_info(class, fingerprint)("%s : expected = " PTR64_FORMAT " actual = " PTR64_FORMAT, ik->external_name(), aot_fp, cds_fp);
1423 }
1424 }
1425 return ik;
1426 }
1427 #endif // INCLUDE_CDS
1428
1429 InstanceKlass* SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1430
1431 if (class_loader.is_null()) {
1432 ResourceMark rm;
1433 PackageEntry* pkg_entry = NULL;
1434 bool search_only_bootloader_append = false;
1435 ClassLoaderData *loader_data = class_loader_data(class_loader);
1436
1437 // Find the package in the boot loader's package entry table.
1438 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK_NULL);
1439 if (pkg_name != NULL) {
1440 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1441 }
1442
1443 // Prior to attempting to load the class, enforce the boot loader's
1444 // visibility boundaries.
1445 if (!Universe::is_module_initialized()) {
1446 // During bootstrapping, prior to module initialization, any
1447 // class attempting to be loaded must be checked against the
1448 // java.base packages in the boot loader's PackageEntryTable.
1449 // No class outside of java.base is allowed to be loaded during
1450 // this bootstrapping window.
1451 if (!DumpSharedSpaces) {
1452 if (pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1453 // Class is either in the unnamed package or in
1454 // a named package within the unnamed module. Either
1455 // case is outside of java.base, do not attempt to
1456 // load the class post java.base definition. If
1457 // java.base has not been defined, let the class load
1458 // and its package will be checked later by
1459 // ModuleEntryTable::verify_javabase_packages.
1460 if (ModuleEntryTable::javabase_defined()) {
1461 return NULL;
1462 }
1463 } else {
1464 // Check that the class' package is defined within java.base.
1465 ModuleEntry* mod_entry = pkg_entry->module();
1466 Symbol* mod_entry_name = mod_entry->name();
1467 if (mod_entry_name->fast_compare(vmSymbols::java_base()) != 0) {
1468 return NULL;
1469 }
1470 }
1471 }
1472 } else {
1473 assert(!DumpSharedSpaces, "Archive dumped after module system initialization");
1474 // After the module system has been initialized, check if the class'
1475 // package is in a module defined to the boot loader.
1476 if (pkg_name == NULL || pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1477 // Class is either in the unnamed package, in a named package
1478 // within a module not defined to the boot loader or in a
1479 // a named package within the unnamed module. In all cases,
1480 // limit visibility to search for the class only in the boot
1481 // loader's append path.
1482 search_only_bootloader_append = true;
1483 }
1484 }
1485
1486 // Prior to bootstrapping's module initialization, never load a class outside
1487 // of the boot loader's module path
1488 assert(Universe::is_module_initialized() || DumpSharedSpaces ||
1489 !search_only_bootloader_append,
1490 "Attempt to load a class outside of boot loader's module path");
1491
1492 // Search the shared system dictionary for classes preloaded into the
1493 // shared spaces.
1494 InstanceKlass* k = NULL;
1495 {
1496 #if INCLUDE_CDS
1497 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1498 k = load_shared_class(class_name, class_loader, THREAD);
1499 #endif
1500 }
1501
1502 if (k == NULL) {
1503 // Use VM class loader
1504 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1505 k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_NULL);
1506 }
1507
1508 // find_or_define_instance_class may return a different InstanceKlass
1509 if (k != NULL) {
1510 InstanceKlass* defined_k =
1511 find_or_define_instance_class(class_name, class_loader, k, THREAD);
1512 if (!HAS_PENDING_EXCEPTION && defined_k != k) {
1513 // If a parallel capable class loader already defined this class, register 'k' for cleanup.
1514 assert(defined_k != NULL, "Should have a klass if there's no exception");
1515 loader_data->add_to_deallocate_list(k);
1516 k = defined_k;
1517 } else if (HAS_PENDING_EXCEPTION) {
1518 loader_data->add_to_deallocate_list(k);
1519 return NULL;
1520 }
1521 }
1522 return k;
1523 } else {
1524 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1525 ResourceMark rm(THREAD);
1526
1527 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1528 JavaThread* jt = (JavaThread*) THREAD;
1529
1530 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1531 ClassLoader::perf_app_classload_selftime(),
1532 ClassLoader::perf_app_classload_count(),
1533 jt->get_thread_stat()->perf_recursion_counts_addr(),
1534 jt->get_thread_stat()->perf_timers_addr(),
1535 PerfClassTraceTime::CLASS_LOAD);
1536
1537 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_NULL);
1538 // Translate to external class name format, i.e., convert '/' chars to '.'
1539 Handle string = java_lang_String::externalize_classname(s, CHECK_NULL);
1540
1541 JavaValue result(T_OBJECT);
1542
1543 InstanceKlass* spec_klass = SystemDictionary::ClassLoader_klass();
1544
1545 // Call public unsynchronized loadClass(String) directly for all class loaders
1546 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
1547 // acquire a class-name based lock rather than the class loader object lock.
1548 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
1549 // so the call to loadClassInternal() was not required.
1550 //
1551 // UnsyncloadClass flag means both call loadClass(String) and do
1552 // not acquire the class loader lock even for class loaders that are
1553 // not parallelCapable. This was a risky transitional
1554 // flag for diagnostic purposes only. It is risky to call
1555 // custom class loaders without synchronization.
1556 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1557 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
1558 // Do NOT assume this will be supported in future releases.
1559 //
1560 // Added MustCallLoadClassInternal in case we discover in the field
1561 // a customer that counts on this call
1562 if (MustCallLoadClassInternal && has_loadClassInternal()) {
1563 JavaCalls::call_special(&result,
1564 class_loader,
1565 spec_klass,
1566 vmSymbols::loadClassInternal_name(),
1567 vmSymbols::string_class_signature(),
1568 string,
1569 CHECK_NULL);
1570 } else {
1571 JavaCalls::call_virtual(&result,
1572 class_loader,
1573 spec_klass,
1574 vmSymbols::loadClass_name(),
1575 vmSymbols::string_class_signature(),
1576 string,
1577 CHECK_NULL);
1578 }
1579
1580 assert(result.get_type() == T_OBJECT, "just checking");
1581 oop obj = (oop) result.get_jobject();
1582
1583 // Primitive classes return null since forName() can not be
1584 // used to obtain any of the Class objects representing primitives or void
1585 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1586 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(obj));
1587 // For user defined Java class loaders, check that the name returned is
1588 // the same as that requested. This check is done for the bootstrap
1589 // loader when parsing the class file.
1590 if (class_name == k->name()) {
1591 return k;
1592 }
1593 }
1594 // Class is not found or has the wrong name, return NULL
1595 return NULL;
1596 }
1597 }
1598
1599 void SystemDictionary::define_instance_class(InstanceKlass* k, TRAPS) {
1600
1601 HandleMark hm(THREAD);
1602 ClassLoaderData* loader_data = k->class_loader_data();
1603 Handle class_loader_h(THREAD, loader_data->class_loader());
1604
1605 // for bootstrap and other parallel classloaders don't acquire lock,
1606 // use placeholder token
1607 // If a parallelCapable class loader calls define_instance_class instead of
1608 // find_or_define_instance_class to get here, we have a timing
1609 // hole with systemDictionary updates and check_constraints
1610 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1611 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1612 compute_loader_lock_object(class_loader_h, THREAD)),
1613 "define called without lock");
1614 }
1615
1616 // Check class-loading constraints. Throw exception if violation is detected.
1617 // Grabs and releases SystemDictionary_lock
1618 // The check_constraints/find_class call and update_dictionary sequence
1619 // must be "atomic" for a specific class/classloader pair so we never
1620 // define two different instanceKlasses for that class/classloader pair.
1621 // Existing classloaders will call define_instance_class with the
1622 // classloader lock held
1623 // Parallel classloaders will call find_or_define_instance_class
1624 // which will require a token to perform the define class
1625 Symbol* name_h = k->name();
1626 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1627 int d_index = dictionary()->hash_to_index(d_hash);
1628 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1629
1630 // Register class just loaded with class loader (placed in Vector)
1631 // Note we do this before updating the dictionary, as this can
1632 // fail with an OutOfMemoryError (if it does, we will *not* put this
1633 // class in the dictionary and will not update the class hierarchy).
1634 // JVMTI FollowReferences needs to find the classes this way.
1635 if (k->class_loader() != NULL) {
1636 methodHandle m(THREAD, Universe::loader_addClass_method());
1637 JavaValue result(T_VOID);
1638 JavaCallArguments args(class_loader_h);
1639 args.push_oop(Handle(THREAD, k->java_mirror()));
1640 JavaCalls::call(&result, m, &args, CHECK);
1641 }
1642
1643 // Add the new class. We need recompile lock during update of CHA.
1644 {
1645 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1646 int p_index = placeholders()->hash_to_index(p_hash);
1647
1648 MutexLocker mu_r(Compile_lock, THREAD);
1649
1650 // Add to class hierarchy, initialize vtables, and do possible
1651 // deoptimizations.
1652 add_to_hierarchy(k, CHECK); // No exception, but can block
1653
1654 // Add to systemDictionary - so other classes can see it.
1655 // Grabs and releases SystemDictionary_lock
1656 update_dictionary(d_index, d_hash, p_index, p_hash,
1657 k, class_loader_h, THREAD);
1658 }
1659 k->eager_initialize(THREAD);
1660
1661 // notify jvmti
1662 if (JvmtiExport::should_post_class_load()) {
1663 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1664 JvmtiExport::post_class_load((JavaThread *) THREAD, k);
1665
1666 }
1667 class_define_event(k, loader_data);
1668 }
1669
1670 // Support parallel classloading
1671 // All parallel class loaders, including bootstrap classloader
1672 // lock a placeholder entry for this class/class_loader pair
1673 // to allow parallel defines of different classes for this class loader
1674 // With AllowParallelDefine flag==true, in case they do not synchronize around
1675 // FindLoadedClass/DefineClass, calls, we check for parallel
1676 // loading for them, wait if a defineClass is in progress
1677 // and return the initial requestor's results
1678 // This flag does not apply to the bootstrap classloader.
1679 // With AllowParallelDefine flag==false, call through to define_instance_class
1680 // which will throw LinkageError: duplicate class definition.
1681 // False is the requested default.
1682 // For better performance, the class loaders should synchronize
1683 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1684 // potentially waste time reading and parsing the bytestream.
1685 // Note: VM callers should ensure consistency of k/class_name,class_loader
1686 // Be careful when modifying this code: once you have run
1687 // placeholders()->find_and_add(PlaceholderTable::DEFINE_CLASS),
1688 // you need to find_and_remove it before returning.
1689 // So be careful to not exit with a CHECK_ macro betweeen these calls.
1690 InstanceKlass* SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader,
1691 InstanceKlass* k, TRAPS) {
1692
1693 Symbol* name_h = k->name(); // passed in class_name may be null
1694 ClassLoaderData* loader_data = class_loader_data(class_loader);
1695
1696 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1697 int d_index = dictionary()->hash_to_index(d_hash);
1698
1699 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1700 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1701 int p_index = placeholders()->hash_to_index(p_hash);
1702 PlaceholderEntry* probe;
1703
1704 {
1705 MutexLocker mu(SystemDictionary_lock, THREAD);
1706 // First check if class already defined
1707 if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
1708 InstanceKlass* check = find_class(d_index, d_hash, name_h, loader_data);
1709 if (check != NULL) {
1710 return check;
1711 }
1712 }
1713
1714 // Acquire define token for this class/classloader
1715 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1716 // Wait if another thread defining in parallel
1717 // All threads wait - even those that will throw duplicate class: otherwise
1718 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1719 // if other thread has not finished updating dictionary
1720 while (probe->definer() != NULL) {
1721 SystemDictionary_lock->wait();
1722 }
1723 // Only special cases allow parallel defines and can use other thread's results
1724 // Other cases fall through, and may run into duplicate defines
1725 // caught by finding an entry in the SystemDictionary
1726 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
1727 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1728 SystemDictionary_lock->notify_all();
1729 #ifdef ASSERT
1730 InstanceKlass* check = find_class(d_index, d_hash, name_h, loader_data);
1731 assert(check != NULL, "definer missed recording success");
1732 #endif
1733 return probe->instance_klass();
1734 } else {
1735 // This thread will define the class (even if earlier thread tried and had an error)
1736 probe->set_definer(THREAD);
1737 }
1738 }
1739
1740 define_instance_class(k, THREAD);
1741
1742 Handle linkage_exception = Handle(); // null handle
1743
1744 // definer must notify any waiting threads
1745 {
1746 MutexLocker mu(SystemDictionary_lock, THREAD);
1747 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1748 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1749 if (probe != NULL) {
1750 if (HAS_PENDING_EXCEPTION) {
1751 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1752 CLEAR_PENDING_EXCEPTION;
1753 } else {
1754 probe->set_instance_klass(k);
1755 }
1756 probe->set_definer(NULL);
1757 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1758 SystemDictionary_lock->notify_all();
1759 }
1760 }
1761
1762 // Can't throw exception while holding lock due to rank ordering
1763 if (linkage_exception() != NULL) {
1764 THROW_OOP_(linkage_exception(), NULL); // throws exception and returns
1765 }
1766
1767 return k;
1768 }
1769 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1770 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1771 if (class_loader.is_null()) {
1772 return Handle(THREAD, _system_loader_lock_obj);
1773 } else {
1774 return class_loader;
1775 }
1776 }
1777
1778 // This method is added to check how often we have to wait to grab loader
1779 // lock. The results are being recorded in the performance counters defined in
1780 // ClassLoader::_sync_systemLoaderLockContentionRate and
1781 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1782 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1783 if (!UsePerfData) {
1784 return;
1785 }
1786
1787 assert(!loader_lock.is_null(), "NULL lock object");
1788
1789 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1790 == ObjectSynchronizer::owner_other) {
1791 // contention will likely happen, so increment the corresponding
1792 // contention counter.
1793 if (loader_lock() == _system_loader_lock_obj) {
1794 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1795 } else {
1796 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1797 }
1798 }
1799 }
1800
1801 // ----------------------------------------------------------------------------
1802 // Lookup
1803
1804 InstanceKlass* SystemDictionary::find_class(int index, unsigned int hash,
1805 Symbol* class_name,
1806 ClassLoaderData* loader_data) {
1807 assert_locked_or_safepoint(SystemDictionary_lock);
1808 assert (index == dictionary()->index_for(class_name, loader_data),
1809 "incorrect index?");
1810
1811 return dictionary()->find_class(index, hash, class_name, loader_data);
1812 }
1813
1814
1815 // Basic find on classes in the midst of being loaded
1816 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1817 ClassLoaderData* loader_data) {
1818 assert_locked_or_safepoint(SystemDictionary_lock);
1819 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
1820 int p_index = placeholders()->hash_to_index(p_hash);
1821 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1822 }
1823
1824
1825 // Used for assertions and verification only
1826 InstanceKlass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1827 #ifndef ASSERT
1828 guarantee(VerifyBeforeGC ||
1829 VerifyDuringGC ||
1830 VerifyBeforeExit ||
1831 VerifyDuringStartup ||
1832 VerifyAfterGC, "too expensive");
1833 #endif
1834 assert_locked_or_safepoint(SystemDictionary_lock);
1835
1836 // First look in the loaded class array
1837 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
1838 int d_index = dictionary()->hash_to_index(d_hash);
1839 return find_class(d_index, d_hash, class_name, loader_data);
1840 }
1841
1842
1843 // Get the next class in the dictionary.
1844 Klass* SystemDictionary::try_get_next_class() {
1845 return dictionary()->try_get_next_class();
1846 }
1847
1848
1849 // ----------------------------------------------------------------------------
1850 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1851 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1852 // before a new class is used.
1853
1854 void SystemDictionary::add_to_hierarchy(InstanceKlass* k, TRAPS) {
1855 assert(k != NULL, "just checking");
1856 assert_locked_or_safepoint(Compile_lock);
1857
1858 // Link into hierachy. Make sure the vtables are initialized before linking into
1859 k->append_to_sibling_list(); // add to superklass/sibling list
1860 k->process_interfaces(THREAD); // handle all "implements" declarations
1861 k->set_init_state(InstanceKlass::loaded);
1862 // Now flush all code that depended on old class hierarchy.
1863 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1864 // Also, first reinitialize vtable because it may have gotten out of synch
1865 // while the new class wasn't connected to the class hierarchy.
1866 CodeCache::flush_dependents_on(k);
1867 }
1868
1869 // ----------------------------------------------------------------------------
1870 // GC support
1871
1872 // Following roots during mark-sweep is separated in two phases.
1873 //
1874 // The first phase follows preloaded classes and all other system
1875 // classes, since these will never get unloaded anyway.
1876 //
1877 // The second phase removes (unloads) unreachable classes from the
1878 // system dictionary and follows the remaining classes' contents.
1879
1880 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1881 roots_oops_do(blk, NULL);
1882 }
1883
1884 // Calculate a "good" systemdictionary size based
1885 // on predicted or current loaded classes count
1886 int SystemDictionary::calculate_systemdictionary_size(int classcount) {
1887 int newsize = _old_default_sdsize;
1888 if ((classcount > 0) && !DumpSharedSpaces) {
1889 int desiredsize = classcount/_average_depth_goal;
1890 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
1891 newsize = _primelist[++_sdgeneration]) {
1892 if (desiredsize <= newsize) {
1893 break;
1894 }
1895 }
1896 }
1897 return newsize;
1898 }
1899
1900 #ifdef ASSERT
1901 class VerifySDReachableAndLiveClosure : public OopClosure {
1902 private:
1903 BoolObjectClosure* _is_alive;
1904
1905 template <class T> void do_oop_work(T* p) {
1906 oop obj = oopDesc::load_decode_heap_oop(p);
1907 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
1908 }
1909
1910 public:
1911 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
1912
1913 virtual void do_oop(oop* p) { do_oop_work(p); }
1914 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1915 };
1916 #endif
1917
1918 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1919 // Note: anonymous classes are not in the SD.
1920 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive,
1921 GCTimer* gc_timer,
1922 bool do_cleaning) {
1923
1924
1925 bool unloading_occurred;
1926 {
1927 GCTraceTime(Debug, gc, phases) t("ClassLoaderData", gc_timer);
1928
1929 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1930 unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive,
1931 do_cleaning);
1932 }
1933
1934 if (unloading_occurred) {
1935 GCTraceTime(Debug, gc, phases) t("Dictionary", gc_timer);
1936 dictionary()->do_unloading();
1937 constraints()->purge_loader_constraints();
1938 resolution_errors()->purge_resolution_errors();
1939 }
1940
1941 {
1942 GCTraceTime(Debug, gc, phases) t("ProtectionDomainCacheTable", gc_timer);
1943 // Oops referenced by the system dictionary may get unreachable independently
1944 // of the class loader (eg. cached protection domain oops). So we need to
1945 // explicitly unlink them here instead of in Dictionary::do_unloading.
1946 dictionary()->unlink(is_alive);
1947 #ifdef ASSERT
1948 VerifySDReachableAndLiveClosure cl(is_alive);
1949 dictionary()->oops_do(&cl);
1950 #endif
1951 }
1952
1953 if (do_cleaning) {
1954 GCTraceTime(Debug, gc, phases) t("ResolvedMethodTable", gc_timer);
1955 ResolvedMethodTable::unlink(is_alive);
1956 }
1957
1958 return unloading_occurred;
1959 }
1960
1961 void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
1962 strong->do_oop(&_java_system_loader);
1963 strong->do_oop(&_system_loader_lock_obj);
1964 CDS_ONLY(SystemDictionaryShared::roots_oops_do(strong);)
1965
1966 // Adjust dictionary
1967 dictionary()->roots_oops_do(strong, weak);
1968
1969 // Visit extra methods
1970 invoke_method_table()->oops_do(strong);
1971
1972 if (weak != NULL) {
1973 ResolvedMethodTable::oops_do(weak);
1974 }
1975 }
1976
1977 void SystemDictionary::oops_do(OopClosure* f) {
1978 f->do_oop(&_java_system_loader);
1979 f->do_oop(&_system_loader_lock_obj);
1980 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1981
1982 // Adjust dictionary
1983 dictionary()->oops_do(f);
1984
1985 // Visit extra methods
1986 invoke_method_table()->oops_do(f);
1987
1988 ResolvedMethodTable::oops_do(f);
1989 }
1990
1991 // Just the classes from defining class loaders
1992 // Don't iterate over placeholders
1993 void SystemDictionary::classes_do(void f(Klass*)) {
1994 dictionary()->classes_do(f);
1995 }
1996
1997 // Added for initialize_itable_for_klass
1998 // Just the classes from defining class loaders
1999 // Don't iterate over placeholders
2000 void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
2001 dictionary()->classes_do(f, CHECK);
2002 }
2003
2004 // All classes, and their class loaders
2005 // Don't iterate over placeholders
2006 void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
2007 dictionary()->classes_do(f);
2008 }
2009
2010 void SystemDictionary::methods_do(void f(Method*)) {
2011 // Walk methods in loaded classes
2012 ClassLoaderDataGraph::methods_do(f);
2013 // Walk method handle intrinsics
2014 invoke_method_table()->methods_do(f);
2015 }
2016
2017 void SystemDictionary::remove_classes_in_error_state() {
2018 dictionary()->remove_classes_in_error_state();
2019 }
2020
2021 // ----------------------------------------------------------------------------
2022 // Lazily load klasses
2023
2024 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
2025 // if multiple threads calling this function, only one thread will load
2026 // the class. The other threads will find the loaded version once the
2027 // class is loaded.
2028 Klass* aos = _abstract_ownable_synchronizer_klass;
2029 if (aos == NULL) {
2030 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
2031 // Force a fence to prevent any read before the write completes
2032 OrderAccess::fence();
2033 _abstract_ownable_synchronizer_klass = InstanceKlass::cast(k);
2034 }
2035 }
2036
2037 // ----------------------------------------------------------------------------
2038 // Initialization
2039
2040 void SystemDictionary::initialize(TRAPS) {
2041 // Allocate arrays
2042 assert(dictionary() == NULL,
2043 "SystemDictionary should only be initialized once");
2044 _sdgeneration = 0;
2045 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
2046 _placeholders = new PlaceholderTable(_nof_buckets);
2047 _number_of_modifications = 0;
2048 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
2049 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
2050 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
2051
2052 // Allocate private object used as system class loader lock
2053 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
2054 // Initialize basic classes
2055 initialize_preloaded_classes(CHECK);
2056 }
2057
2058 // Compact table of directions on the initialization of klasses:
2059 static const short wk_init_info[] = {
2060 #define WK_KLASS_INIT_INFO(name, symbol, option) \
2061 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
2062 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
2063 | (int)SystemDictionary::option ),
2064 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
2065 #undef WK_KLASS_INIT_INFO
2066 0
2067 };
2068
2069 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
2070 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
2071 int info = wk_init_info[id - FIRST_WKID];
2072 int sid = (info >> CEIL_LG_OPTION_LIMIT);
2073 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
2074 InstanceKlass** klassp = &_well_known_klasses[id];
2075
2076 bool must_load;
2077 #if INCLUDE_JVMCI
2078 if (EnableJVMCI) {
2079 // If JVMCI is enabled we require its classes to be found.
2080 must_load = (init_opt < SystemDictionary::Opt) || (init_opt == SystemDictionary::Jvmci);
2081 } else
2082 #endif
2083 {
2084 must_load = (init_opt < SystemDictionary::Opt);
2085 }
2086
2087 if ((*klassp) == NULL) {
2088 Klass* k;
2089 if (must_load) {
2090 k = resolve_or_fail(symbol, true, CHECK_0); // load required class
2091 } else {
2092 k = resolve_or_null(symbol, CHECK_0); // load optional klass
2093 }
2094 (*klassp) = (k == NULL) ? NULL : InstanceKlass::cast(k);
2095 }
2096 return ((*klassp) != NULL);
2097 }
2098
2099 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
2100 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
2101 for (int id = (int)start_id; id < (int)limit_id; id++) {
2102 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
2103 int info = wk_init_info[id - FIRST_WKID];
2104 int sid = (info >> CEIL_LG_OPTION_LIMIT);
2105 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
2106
2107 initialize_wk_klass((WKID)id, opt, CHECK);
2108 }
2109
2110 // move the starting value forward to the limit:
2111 start_id = limit_id;
2112 }
2113
2114 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
2115 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
2116
2117 // Create the ModuleEntry for java.base. This call needs to be done here,
2118 // after vmSymbols::initialize() is called but before any classes are pre-loaded.
2119 ClassLoader::classLoader_init2(CHECK);
2120
2121 // Preload commonly used klasses
2122 WKID scan = FIRST_WKID;
2123 // first do Object, then String, Class
2124 if (UseSharedSpaces) {
2125 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
2126 // Initialize the constant pool for the Object_class
2127 Object_klass()->constants()->restore_unshareable_info(CHECK);
2128 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2129 } else {
2130 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2131 }
2132
2133 // Calculate offsets for String and Class classes since they are loaded and
2134 // can be used after this point.
2135 java_lang_String::compute_offsets();
2136 java_lang_Class::compute_offsets();
2137
2138 // Fixup mirrors for classes loaded before java.lang.Class.
2139 // These calls iterate over the objects currently in the perm gen
2140 // so calling them at this point is matters (not before when there
2141 // are fewer objects and not later after there are more objects
2142 // in the perm gen.
2143 Universe::initialize_basic_type_mirrors(CHECK);
2144 Universe::fixup_mirrors(CHECK);
2145
2146 // do a bunch more:
2147 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
2148
2149 // Preload ref klasses and set reference types
2150 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
2151 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
2152
2153 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
2154 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
2155 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
2156 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
2157 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
2158
2159 // JSR 292 classes
2160 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
2161 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
2162 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
2163 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
2164 initialize_wk_klasses_until(NOT_JVMCI(WKID_LIMIT) JVMCI_ONLY(FIRST_JVMCI_WKID), scan, CHECK);
2165
2166 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
2167 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
2168 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
2169 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
2170 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
2171 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
2172 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
2173 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
2174 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
2175 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
2176
2177 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
2178 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
2179 _has_loadClassInternal = (method != NULL);
2180 }
2181 { // Compute whether we should use checkPackageAccess or NOT
2182 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
2183 _has_checkPackageAccess = (method != NULL);
2184 }
2185 }
2186
2187 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
2188 // If so, returns the basic type it holds. If not, returns T_OBJECT.
2189 BasicType SystemDictionary::box_klass_type(Klass* k) {
2190 assert(k != NULL, "");
2191 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
2192 if (_box_klasses[i] == k)
2193 return (BasicType)i;
2194 }
2195 return T_OBJECT;
2196 }
2197
2198 // Constraints on class loaders. The details of the algorithm can be
2199 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
2200 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
2201 // that the system dictionary needs to maintain a set of contraints that
2202 // must be satisfied by all classes in the dictionary.
2203 // if defining is true, then LinkageError if already in systemDictionary
2204 // if initiating loader, then ok if InstanceKlass matches existing entry
2205
2206 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
2207 InstanceKlass* k,
2208 Handle class_loader, bool defining,
2209 TRAPS) {
2210 const char *linkage_error1 = NULL;
2211 const char *linkage_error2 = NULL;
2212 {
2213 Symbol* name = k->name();
2214 ClassLoaderData *loader_data = class_loader_data(class_loader);
2215
2216 MutexLocker mu(SystemDictionary_lock, THREAD);
2217
2218 InstanceKlass* check = find_class(d_index, d_hash, name, loader_data);
2219 if (check != NULL) {
2220 // if different InstanceKlass - duplicate class definition,
2221 // else - ok, class loaded by a different thread in parallel,
2222 // we should only have found it if it was done loading and ok to use
2223 // system dictionary only holds instance classes, placeholders
2224 // also holds array classes
2225
2226 assert(check->is_instance_klass(), "noninstance in systemdictionary");
2227 if ((defining == true) || (k != check)) {
2228 linkage_error1 = "loader (instance of ";
2229 linkage_error2 = "): attempted duplicate class definition for name: \"";
2230 } else {
2231 return;
2232 }
2233 }
2234
2235 #ifdef ASSERT
2236 Symbol* ph_check = find_placeholder(name, loader_data);
2237 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2238 #endif
2239
2240 if (linkage_error1 == NULL) {
2241 if (constraints()->check_or_update(k, class_loader, name) == false) {
2242 linkage_error1 = "loader constraint violation: loader (instance of ";
2243 linkage_error2 = ") previously initiated loading for a different type with name \"";
2244 }
2245 }
2246 }
2247
2248 // Throw error now if needed (cannot throw while holding
2249 // SystemDictionary_lock because of rank ordering)
2250
2251 if (linkage_error1) {
2252 ResourceMark rm(THREAD);
2253 const char* class_loader_name = loader_name(class_loader());
2254 char* type_name = k->name()->as_C_string();
2255 size_t buflen = strlen(linkage_error1) + strlen(class_loader_name) +
2256 strlen(linkage_error2) + strlen(type_name) + 2; // +2 for '"' and null byte.
2257 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
2258 jio_snprintf(buf, buflen, "%s%s%s%s\"", linkage_error1, class_loader_name, linkage_error2, type_name);
2259 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
2260 }
2261 }
2262
2263
2264 // Update system dictionary - done after check_constraint and add_to_hierachy
2265 // have been called.
2266 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
2267 int p_index, unsigned int p_hash,
2268 InstanceKlass* k,
2269 Handle class_loader,
2270 TRAPS) {
2271 // Compile_lock prevents systemDictionary updates during compilations
2272 assert_locked_or_safepoint(Compile_lock);
2273 Symbol* name = k->name();
2274 ClassLoaderData *loader_data = class_loader_data(class_loader);
2275
2276 {
2277 MutexLocker mu1(SystemDictionary_lock, THREAD);
2278
2279 // See whether biased locking is enabled and if so set it for this
2280 // klass.
2281 // Note that this must be done past the last potential blocking
2282 // point / safepoint. We enable biased locking lazily using a
2283 // VM_Operation to iterate the SystemDictionary and installing the
2284 // biasable mark word into each InstanceKlass's prototype header.
2285 // To avoid race conditions where we accidentally miss enabling the
2286 // optimization for one class in the process of being added to the
2287 // dictionary, we must not safepoint after the test of
2288 // BiasedLocking::enabled().
2289 if (UseBiasedLocking && BiasedLocking::enabled()) {
2290 // Set biased locking bit for all loaded classes; it will be
2291 // cleared if revocation occurs too often for this type
2292 // NOTE that we must only do this when the class is initally
2293 // defined, not each time it is referenced from a new class loader
2294 if (k->class_loader() == class_loader()) {
2295 k->set_prototype_header(markOopDesc::biased_locking_prototype());
2296 }
2297 }
2298
2299 // Make a new system dictionary entry.
2300 InstanceKlass* sd_check = find_class(d_index, d_hash, name, loader_data);
2301 if (sd_check == NULL) {
2302 dictionary()->add_klass(name, loader_data, k);
2303 notice_modification();
2304 }
2305 #ifdef ASSERT
2306 sd_check = find_class(d_index, d_hash, name, loader_data);
2307 assert (sd_check != NULL, "should have entry in system dictionary");
2308 // Note: there may be a placeholder entry: for circularity testing
2309 // or for parallel defines
2310 #endif
2311 SystemDictionary_lock->notify_all();
2312 }
2313 }
2314
2315
2316 // Try to find a class name using the loader constraints. The
2317 // loader constraints might know about a class that isn't fully loaded
2318 // yet and these will be ignored.
2319 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2320 Symbol* class_name, Handle class_loader, TRAPS) {
2321
2322 // First see if it has been loaded directly.
2323 // Force the protection domain to be null. (This removes protection checks.)
2324 Handle no_protection_domain;
2325 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2326 no_protection_domain, CHECK_NULL);
2327 if (klass != NULL)
2328 return klass;
2329
2330 // Now look to see if it has been loaded elsewhere, and is subject to
2331 // a loader constraint that would require this loader to return the
2332 // klass that is already loaded.
2333 if (FieldType::is_array(class_name)) {
2334 // For array classes, their Klass*s are not kept in the
2335 // constraint table. The element Klass*s are.
2336 FieldArrayInfo fd;
2337 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
2338 if (t != T_OBJECT) {
2339 klass = Universe::typeArrayKlassObj(t);
2340 } else {
2341 MutexLocker mu(SystemDictionary_lock, THREAD);
2342 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
2343 }
2344 // If element class already loaded, allocate array klass
2345 if (klass != NULL) {
2346 klass = klass->array_klass_or_null(fd.dimension());
2347 }
2348 } else {
2349 MutexLocker mu(SystemDictionary_lock, THREAD);
2350 // Non-array classes are easy: simply check the constraint table.
2351 klass = constraints()->find_constrained_klass(class_name, class_loader);
2352 }
2353
2354 return klass;
2355 }
2356
2357
2358 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2359 Handle class_loader1,
2360 Handle class_loader2,
2361 Thread* THREAD) {
2362 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2363 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2364
2365 Symbol* constraint_name = NULL;
2366 if (!FieldType::is_array(class_name)) {
2367 constraint_name = class_name;
2368 } else {
2369 // For array classes, their Klass*s are not kept in the
2370 // constraint table. The element classes are.
2371 FieldArrayInfo fd;
2372 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
2373 // primitive types always pass
2374 if (t != T_OBJECT) {
2375 return true;
2376 } else {
2377 constraint_name = fd.object_key();
2378 }
2379 }
2380 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
2381 int d_index1 = dictionary()->hash_to_index(d_hash1);
2382
2383 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
2384 int d_index2 = dictionary()->hash_to_index(d_hash2);
2385 {
2386 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2387
2388 // Better never do a GC while we're holding these oops
2389 NoSafepointVerifier nosafepoint;
2390
2391 InstanceKlass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
2392 InstanceKlass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
2393 return constraints()->add_entry(constraint_name, klass1, class_loader1,
2394 klass2, class_loader2);
2395 }
2396 }
2397
2398 // Add entry to resolution error table to record the error when the first
2399 // attempt to resolve a reference to a class has failed.
2400 void SystemDictionary::add_resolution_error(const constantPoolHandle& pool, int which,
2401 Symbol* error, Symbol* message) {
2402 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2403 int index = resolution_errors()->hash_to_index(hash);
2404 {
2405 MutexLocker ml(SystemDictionary_lock, Thread::current());
2406 resolution_errors()->add_entry(index, hash, pool, which, error, message);
2407 }
2408 }
2409
2410 // Delete a resolution error for RedefineClasses for a constant pool is going away
2411 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2412 resolution_errors()->delete_entry(pool);
2413 }
2414
2415 // Lookup resolution error table. Returns error if found, otherwise NULL.
2416 Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool, int which,
2417 Symbol** message) {
2418 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2419 int index = resolution_errors()->hash_to_index(hash);
2420 {
2421 MutexLocker ml(SystemDictionary_lock, Thread::current());
2422 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2423 if (entry != NULL) {
2424 *message = entry->message();
2425 return entry->error();
2426 } else {
2427 return NULL;
2428 }
2429 }
2430 }
2431
2432
2433 // Signature constraints ensure that callers and callees agree about
2434 // the meaning of type names in their signatures. This routine is the
2435 // intake for constraints. It collects them from several places:
2436 //
2437 // * LinkResolver::resolve_method (if check_access is true) requires
2438 // that the resolving class (the caller) and the defining class of
2439 // the resolved method (the callee) agree on each type in the
2440 // method's signature.
2441 //
2442 // * LinkResolver::resolve_interface_method performs exactly the same
2443 // checks.
2444 //
2445 // * LinkResolver::resolve_field requires that the constant pool
2446 // attempting to link to a field agree with the field's defining
2447 // class about the type of the field signature.
2448 //
2449 // * klassVtable::initialize_vtable requires that, when a class
2450 // overrides a vtable entry allocated by a superclass, that the
2451 // overriding method (i.e., the callee) agree with the superclass
2452 // on each type in the method's signature.
2453 //
2454 // * klassItable::initialize_itable requires that, when a class fills
2455 // in its itables, for each non-abstract method installed in an
2456 // itable, the method (i.e., the callee) agree with the interface
2457 // on each type in the method's signature.
2458 //
2459 // All those methods have a boolean (check_access, checkconstraints)
2460 // which turns off the checks. This is used from specialized contexts
2461 // such as bootstrapping, dumping, and debugging.
2462 //
2463 // No direct constraint is placed between the class and its
2464 // supertypes. Constraints are only placed along linked relations
2465 // between callers and callees. When a method overrides or implements
2466 // an abstract method in a supertype (superclass or interface), the
2467 // constraints are placed as if the supertype were the caller to the
2468 // overriding method. (This works well, since callers to the
2469 // supertype have already established agreement between themselves and
2470 // the supertype.) As a result of all this, a class can disagree with
2471 // its supertype about the meaning of a type name, as long as that
2472 // class neither calls a relevant method of the supertype, nor is
2473 // called (perhaps via an override) from the supertype.
2474 //
2475 //
2476 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2477 //
2478 // Make sure all class components (including arrays) in the given
2479 // signature will be resolved to the same class in both loaders.
2480 // Returns the name of the type that failed a loader constraint check, or
2481 // NULL if no constraint failed. No exception except OOME is thrown.
2482 // Arrays are not added to the loader constraint table, their elements are.
2483 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2484 Handle loader1, Handle loader2,
2485 bool is_method, TRAPS) {
2486 // Nothing to do if loaders are the same.
2487 if (loader1() == loader2()) {
2488 return NULL;
2489 }
2490
2491 SignatureStream sig_strm(signature, is_method);
2492 while (!sig_strm.is_done()) {
2493 if (sig_strm.is_object()) {
2494 Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
2495 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2496 return sig;
2497 }
2498 }
2499 sig_strm.next();
2500 }
2501 return NULL;
2502 }
2503
2504
2505 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2506 Symbol* signature,
2507 TRAPS) {
2508 methodHandle empty;
2509 assert(MethodHandles::is_signature_polymorphic(iid) &&
2510 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2511 iid != vmIntrinsics::_invokeGeneric,
2512 "must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid));
2513
2514 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2515 int index = invoke_method_table()->hash_to_index(hash);
2516 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2517 methodHandle m;
2518 if (spe == NULL || spe->method() == NULL) {
2519 spe = NULL;
2520 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2521 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
2522 if (!Arguments::is_interpreter_only()) {
2523 // Generate a compiled form of the MH intrinsic.
2524 AdapterHandlerLibrary::create_native_wrapper(m);
2525 // Check if have the compiled code.
2526 if (!m->has_compiled_code()) {
2527 THROW_MSG_(vmSymbols::java_lang_VirtualMachineError(),
2528 "Out of space in CodeCache for method handle intrinsic", empty);
2529 }
2530 }
2531 // Now grab the lock. We might have to throw away the new method,
2532 // if a racing thread has managed to install one at the same time.
2533 {
2534 MutexLocker ml(SystemDictionary_lock, THREAD);
2535 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2536 if (spe == NULL)
2537 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2538 if (spe->method() == NULL)
2539 spe->set_method(m());
2540 }
2541 }
2542
2543 assert(spe != NULL && spe->method() != NULL, "");
2544 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2545 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2546 "MH intrinsic invariant");
2547 return spe->method();
2548 }
2549
2550 // Helper for unpacking the return value from linkMethod and linkCallSite.
2551 static methodHandle unpack_method_and_appendix(Handle mname,
2552 Klass* accessing_klass,
2553 objArrayHandle appendix_box,
2554 Handle* appendix_result,
2555 TRAPS) {
2556 methodHandle empty;
2557 if (mname.not_null()) {
2558 Method* m = java_lang_invoke_MemberName::vmtarget(mname());
2559 if (m != NULL) {
2560 oop appendix = appendix_box->obj_at(0);
2561 if (TraceMethodHandles) {
2562 #ifndef PRODUCT
2563 ttyLocker ttyl;
2564 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2565 m->print();
2566 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2567 tty->cr();
2568 #endif //PRODUCT
2569 }
2570 (*appendix_result) = Handle(THREAD, appendix);
2571 // the target is stored in the cpCache and if a reference to this
2572 // MethodName is dropped we need a way to make sure the
2573 // class_loader containing this method is kept alive.
2574 // FIXME: the appendix might also preserve this dependency.
2575 ClassLoaderData* this_key = accessing_klass->class_loader_data();
2576 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
2577 return methodHandle(THREAD, m);
2578 }
2579 }
2580 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
2581 return empty;
2582 }
2583
2584 methodHandle SystemDictionary::find_method_handle_invoker(Klass* klass,
2585 Symbol* name,
2586 Symbol* signature,
2587 Klass* accessing_klass,
2588 Handle *appendix_result,
2589 Handle *method_type_result,
2590 TRAPS) {
2591 methodHandle empty;
2592 assert(THREAD->can_call_java() ,"");
2593 Handle method_type =
2594 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
2595
2596 int ref_kind = JVM_REF_invokeVirtual;
2597 oop name_oop = StringTable::intern(name, CHECK_(empty));
2598 Handle name_str (THREAD, name_oop);
2599 objArrayHandle appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2600 assert(appendix_box->obj_at(0) == NULL, "");
2601
2602 // This should not happen. JDK code should take care of that.
2603 if (accessing_klass == NULL || method_type.is_null()) {
2604 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
2605 }
2606
2607 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2608 JavaCallArguments args;
2609 args.push_oop(Handle(THREAD, accessing_klass->java_mirror()));
2610 args.push_int(ref_kind);
2611 args.push_oop(Handle(THREAD, klass->java_mirror()));
2612 args.push_oop(name_str);
2613 args.push_oop(method_type);
2614 args.push_oop(appendix_box);
2615 JavaValue result(T_OBJECT);
2616 JavaCalls::call_static(&result,
2617 SystemDictionary::MethodHandleNatives_klass(),
2618 vmSymbols::linkMethod_name(),
2619 vmSymbols::linkMethod_signature(),
2620 &args, CHECK_(empty));
2621 Handle mname(THREAD, (oop) result.get_jobject());
2622 (*method_type_result) = method_type;
2623 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2624 }
2625
2626 // Decide if we can globally cache a lookup of this class, to be returned to any client that asks.
2627 // We must ensure that all class loaders everywhere will reach this class, for any client.
2628 // This is a safe bet for public classes in java.lang, such as Object and String.
2629 // We also include public classes in java.lang.invoke, because they appear frequently in system-level method types.
2630 // Out of an abundance of caution, we do not include any other classes, not even for packages like java.util.
2631 static bool is_always_visible_class(oop mirror) {
2632 Klass* klass = java_lang_Class::as_Klass(mirror);
2633 if (klass->is_objArray_klass()) {
2634 klass = ObjArrayKlass::cast(klass)->bottom_klass(); // check element type
2635 }
2636 if (klass->is_typeArray_klass()) {
2637 return true; // primitive array
2638 }
2639 assert(klass->is_instance_klass(), "%s", klass->external_name());
2640 return klass->is_public() &&
2641 (InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::Object_klass()) || // java.lang
2642 InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::MethodHandle_klass())); // java.lang.invoke
2643 }
2644
2645 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2646 // signature, as interpreted relative to the given class loader.
2647 // Because of class loader constraints, all method handle usage must be
2648 // consistent with this loader.
2649 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2650 Klass* accessing_klass,
2651 TRAPS) {
2652 Handle empty;
2653 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2654 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2655 int index = invoke_method_table()->hash_to_index(hash);
2656 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2657 if (spe != NULL && spe->method_type() != NULL) {
2658 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2659 return Handle(THREAD, spe->method_type());
2660 } else if (!THREAD->can_call_java()) {
2661 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2662 return Handle(); // do not attempt from within compiler, unless it was cached
2663 }
2664
2665 Handle class_loader, protection_domain;
2666 if (accessing_klass != NULL) {
2667 class_loader = Handle(THREAD, accessing_klass->class_loader());
2668 protection_domain = Handle(THREAD, accessing_klass->protection_domain());
2669 }
2670 bool can_be_cached = true;
2671 int npts = ArgumentCount(signature).size();
2672 objArrayHandle pts = oopFactory::new_objArray_handle(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2673 int arg = 0;
2674 Handle rt; // the return type from the signature
2675 ResourceMark rm(THREAD);
2676 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2677 oop mirror = NULL;
2678 if (can_be_cached) {
2679 // Use neutral class loader to lookup candidate classes to be placed in the cache.
2680 mirror = ss.as_java_mirror(Handle(), Handle(),
2681 SignatureStream::ReturnNull, CHECK_(empty));
2682 if (mirror == NULL || (ss.is_object() && !is_always_visible_class(mirror))) {
2683 // Fall back to accessing_klass context.
2684 can_be_cached = false;
2685 }
2686 }
2687 if (!can_be_cached) {
2688 // Resolve, throwing a real error if it doesn't work.
2689 mirror = ss.as_java_mirror(class_loader, protection_domain,
2690 SignatureStream::NCDFError, CHECK_(empty));
2691 }
2692 assert(!oopDesc::is_null(mirror), "%s", ss.as_symbol(THREAD)->as_C_string());
2693 if (ss.at_return_type())
2694 rt = Handle(THREAD, mirror);
2695 else
2696 pts->obj_at_put(arg++, mirror);
2697
2698 // Check accessibility.
2699 if (ss.is_object() && accessing_klass != NULL) {
2700 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2701 mirror = NULL; // safety
2702 // Emulate ConstantPool::verify_constant_pool_resolve.
2703 if (sel_klass->is_objArray_klass())
2704 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
2705 if (sel_klass->is_instance_klass()) {
2706 LinkResolver::check_klass_accessability(accessing_klass, sel_klass, CHECK_(empty));
2707 }
2708 }
2709 }
2710 assert(arg == npts, "");
2711
2712 // call java.lang.invoke.MethodHandleNatives::findMethodHandleType(Class rt, Class[] pts) -> MethodType
2713 JavaCallArguments args(Handle(THREAD, rt()));
2714 args.push_oop(pts);
2715 JavaValue result(T_OBJECT);
2716 JavaCalls::call_static(&result,
2717 SystemDictionary::MethodHandleNatives_klass(),
2718 vmSymbols::findMethodHandleType_name(),
2719 vmSymbols::findMethodHandleType_signature(),
2720 &args, CHECK_(empty));
2721 Handle method_type(THREAD, (oop) result.get_jobject());
2722
2723 if (can_be_cached) {
2724 // We can cache this MethodType inside the JVM.
2725 MutexLocker ml(SystemDictionary_lock, THREAD);
2726 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2727 if (spe == NULL)
2728 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2729 if (spe->method_type() == NULL) {
2730 spe->set_method_type(method_type());
2731 }
2732 }
2733
2734 // report back to the caller with the MethodType
2735 return method_type;
2736 }
2737
2738 // Ask Java code to find or construct a method handle constant.
2739 Handle SystemDictionary::link_method_handle_constant(Klass* caller,
2740 int ref_kind, //e.g., JVM_REF_invokeVirtual
2741 Klass* callee,
2742 Symbol* name_sym,
2743 Symbol* signature,
2744 TRAPS) {
2745 Handle empty;
2746 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
2747 Handle type;
2748 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
2749 type = find_method_handle_type(signature, caller, CHECK_(empty));
2750 } else if (caller == NULL) {
2751 // This should not happen. JDK code should take care of that.
2752 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2753 } else {
2754 ResourceMark rm(THREAD);
2755 SignatureStream ss(signature, false);
2756 if (!ss.is_done()) {
2757 oop mirror = ss.as_java_mirror(Handle(THREAD, caller->class_loader()),
2758 Handle(THREAD, caller->protection_domain()),
2759 SignatureStream::NCDFError, CHECK_(empty));
2760 type = Handle(THREAD, mirror);
2761 ss.next();
2762 if (!ss.is_done()) type = Handle(); // error!
2763 }
2764 }
2765 if (type.is_null()) {
2766 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
2767 }
2768
2769 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2770 JavaCallArguments args;
2771 args.push_oop(Handle(THREAD, caller->java_mirror())); // the referring class
2772 args.push_int(ref_kind);
2773 args.push_oop(Handle(THREAD, callee->java_mirror())); // the target class
2774 args.push_oop(name);
2775 args.push_oop(type);
2776 JavaValue result(T_OBJECT);
2777 JavaCalls::call_static(&result,
2778 SystemDictionary::MethodHandleNatives_klass(),
2779 vmSymbols::linkMethodHandleConstant_name(),
2780 vmSymbols::linkMethodHandleConstant_signature(),
2781 &args, CHECK_(empty));
2782 return Handle(THREAD, (oop) result.get_jobject());
2783 }
2784
2785 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given
2786 // name and signature, as interpreted relative to the given class loader.
2787 methodHandle SystemDictionary::find_dynamic_call_site_invoker(Klass* caller,
2788 Handle bootstrap_specifier,
2789 Symbol* name,
2790 Symbol* type,
2791 Handle *appendix_result,
2792 Handle *method_type_result,
2793 TRAPS) {
2794 methodHandle empty;
2795 Handle bsm, info;
2796 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
2797 bsm = bootstrap_specifier;
2798 } else {
2799 assert(bootstrap_specifier->is_objArray(), "");
2800 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
2801 int len = args->length();
2802 assert(len >= 1, "");
2803 bsm = Handle(THREAD, args->obj_at(0));
2804 if (len > 1) {
2805 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
2806 for (int i = 1; i < len; i++)
2807 args1->obj_at_put(i-1, args->obj_at(i));
2808 info = Handle(THREAD, args1);
2809 }
2810 }
2811 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
2812 "caller must supply a valid BSM");
2813
2814 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
2815 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
2816
2817 // This should not happen. JDK code should take care of that.
2818 if (caller == NULL || method_type.is_null()) {
2819 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
2820 }
2821
2822 objArrayHandle appendix_box = oopFactory::new_objArray_handle(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2823 assert(appendix_box->obj_at(0) == NULL, "");
2824
2825 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
2826 JavaCallArguments args;
2827 args.push_oop(Handle(THREAD, caller->java_mirror()));
2828 args.push_oop(bsm);
2829 args.push_oop(method_name);
2830 args.push_oop(method_type);
2831 args.push_oop(info);
2832 args.push_oop(appendix_box);
2833 JavaValue result(T_OBJECT);
2834 JavaCalls::call_static(&result,
2835 SystemDictionary::MethodHandleNatives_klass(),
2836 vmSymbols::linkCallSite_name(),
2837 vmSymbols::linkCallSite_signature(),
2838 &args, CHECK_(empty));
2839 Handle mname(THREAD, (oop) result.get_jobject());
2840 (*method_type_result) = method_type;
2841 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
2842 }
2843
2844 // Since the identity hash code for symbols changes when the symbols are
2845 // moved from the regular perm gen (hash in the mark word) to the shared
2846 // spaces (hash is the address), the classes loaded into the dictionary
2847 // may be in the wrong buckets.
2848
2849 void SystemDictionary::reorder_dictionary() {
2850 dictionary()->reorder_dictionary();
2851 }
2852
2853
2854 void SystemDictionary::copy_buckets(char** top, char* end) {
2855 dictionary()->copy_buckets(top, end);
2856 }
2857
2858
2859 void SystemDictionary::copy_table(char** top, char* end) {
2860 dictionary()->copy_table(top, end);
2861 }
2862
2863 int SystemDictionary::number_of_classes() {
2864 return dictionary()->number_of_entries();
2865 }
2866
2867
2868 // ----------------------------------------------------------------------------
2869 void SystemDictionary::print_shared(bool details) {
2870 shared_dictionary()->print(details);
2871 }
2872
2873 void SystemDictionary::print(bool details) {
2874 dictionary()->print(details);
2875
2876 // Placeholders
2877 GCMutexLocker mu(SystemDictionary_lock);
2878 placeholders()->print();
2879
2880 // loader constraints - print under SD_lock
2881 constraints()->print();
2882 }
2883
2884
2885 void SystemDictionary::verify() {
2886 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2887 guarantee(constraints() != NULL,
2888 "Verify of loader constraints failed");
2889 guarantee(dictionary()->number_of_entries() >= 0 &&
2890 placeholders()->number_of_entries() >= 0,
2891 "Verify of system dictionary failed");
2892
2893 // Verify dictionary
2894 dictionary()->verify();
2895
2896 GCMutexLocker mu(SystemDictionary_lock);
2897 placeholders()->verify();
2898
2899 // Verify constraint table
2900 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2901 constraints()->verify(dictionary(), placeholders());
2902 }
2903
2904 // caller needs ResourceMark
2905 const char* SystemDictionary::loader_name(const oop loader) {
2906 return ((loader) == NULL ? "<bootloader>" :
2907 InstanceKlass::cast((loader)->klass())->name()->as_C_string());
2908 }
2909
2910 // caller needs ResourceMark
2911 const char* SystemDictionary::loader_name(const ClassLoaderData* loader_data) {
2912 return (loader_data->class_loader() == NULL ? "<bootloader>" :
2913 SystemDictionary::loader_name(loader_data->class_loader()));
2914 }