1 /*
2 * Copyright (c) 1997, 2016, 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 "classfile/classFileParser.hpp"
27 #include "classfile/classFileStream.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/classLoaderData.inline.hpp"
30 #include "classfile/classLoaderExt.hpp"
31 #include "classfile/dictionary.hpp"
32 #include "classfile/javaClasses.inline.hpp"
33 #include "classfile/klassFactory.hpp"
34 #include "classfile/loaderConstraints.hpp"
35 #include "classfile/packageEntry.hpp"
36 #include "classfile/placeholders.hpp"
37 #include "classfile/resolutionErrors.hpp"
38 #include "classfile/stringTable.hpp"
39 #include "classfile/systemDictionary.hpp"
40 #include "classfile/vmSymbols.hpp"
41 #include "code/codeCache.hpp"
42 #include "compiler/compileBroker.hpp"
43 #include "gc/shared/gcLocker.hpp"
44 #include "interpreter/bytecodeStream.hpp"
45 #include "interpreter/interpreter.hpp"
46 #include "memory/filemap.hpp"
47 #include "memory/oopFactory.hpp"
48 #include "memory/resourceArea.hpp"
49 #include "oops/instanceKlass.hpp"
50 #include "oops/instanceRefKlass.hpp"
51 #include "oops/klass.inline.hpp"
52 #include "oops/methodData.hpp"
53 #include "oops/objArrayKlass.hpp"
54 #include "oops/objArrayOop.inline.hpp"
55 #include "oops/oop.inline.hpp"
56 #include "oops/symbol.hpp"
57 #include "oops/typeArrayKlass.hpp"
58 #include "prims/jvmtiEnvBase.hpp"
59 #include "prims/methodHandles.hpp"
60 #include "runtime/arguments.hpp"
61 #include "runtime/biasedLocking.hpp"
62 #include "runtime/fieldType.hpp"
63 #include "runtime/handles.inline.hpp"
64 #include "runtime/java.hpp"
65 #include "runtime/javaCalls.hpp"
66 #include "runtime/mutexLocker.hpp"
67 #include "runtime/orderAccess.inline.hpp"
68 #include "runtime/signature.hpp"
69 #include "services/classLoadingService.hpp"
70 #include "services/threadService.hpp"
71 #include "trace/traceMacros.hpp"
72 #include "utilities/macros.hpp"
73 #include "utilities/ticks.hpp"
74 #if INCLUDE_CDS
75 #include "classfile/sharedClassUtil.hpp"
76 #include "classfile/systemDictionaryShared.hpp"
77 #endif
78 #if INCLUDE_JVMCI
79 #include "jvmci/jvmciRuntime.hpp"
80 #endif
81 #if INCLUDE_TRACE
82 #include "trace/tracing.hpp"
83 #endif
84
85 Dictionary* SystemDictionary::_dictionary = NULL;
86 PlaceholderTable* SystemDictionary::_placeholders = NULL;
87 Dictionary* SystemDictionary::_shared_dictionary = NULL;
88 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
89 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
90 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
91
92
93 int SystemDictionary::_number_of_modifications = 0;
94 int SystemDictionary::_sdgeneration = 0;
95 const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
96 20201,40423,99991};
97
98 oop SystemDictionary::_system_loader_lock_obj = NULL;
99
100 InstanceKlass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
101 = { NULL /*, NULL...*/ };
102
103 InstanceKlass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
104
105 oop SystemDictionary::_java_system_loader = NULL;
106
107 bool SystemDictionary::_has_loadClassInternal = false;
108 bool SystemDictionary::_has_checkPackageAccess = false;
109
110 // lazily initialized klass variables
111 InstanceKlass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
112
113
114 // ----------------------------------------------------------------------------
115 // Java-level SystemLoader
116
117 oop SystemDictionary::java_system_loader() {
118 return _java_system_loader;
119 }
120
121 void SystemDictionary::compute_java_system_loader(TRAPS) {
122 KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass));
123 JavaValue result(T_OBJECT);
124 JavaCalls::call_static(&result,
125 KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)),
126 vmSymbols::getSystemClassLoader_name(),
127 vmSymbols::void_classloader_signature(),
128 CHECK);
129
130 _java_system_loader = (oop)result.get_jobject();
131
132 CDS_ONLY(SystemDictionaryShared::initialize(CHECK);)
133 }
134
135
136 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
137 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
138 return ClassLoaderDataGraph::find_or_create(class_loader, THREAD);
139 }
140
141 // ----------------------------------------------------------------------------
142 // debugging
143
144 #ifdef ASSERT
145
146 // return true if class_name contains no '.' (internal format is '/')
147 bool SystemDictionary::is_internal_format(Symbol* class_name) {
148 if (class_name != NULL) {
149 ResourceMark rm;
150 char* name = class_name->as_C_string();
151 return strchr(name, '.') == NULL;
152 } else {
153 return true;
154 }
155 }
156
157 #endif
158
159 // ----------------------------------------------------------------------------
160 // Parallel class loading check
161
162 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
163 if (UnsyncloadClass || class_loader.is_null()) return true;
164 if (AlwaysLockClassLoader) return false;
165 return java_lang_ClassLoader::parallelCapable(class_loader());
166 }
167 // ----------------------------------------------------------------------------
168 // ParallelDefineClass flag does not apply to bootclass loader
169 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
170 if (class_loader.is_null()) return false;
171 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
172 return true;
173 }
174 return false;
175 }
176
177 /**
178 * Returns true if the passed class loader is the platform class loader.
179 */
180 bool SystemDictionary::is_platform_class_loader(Handle class_loader) {
181 if (class_loader.is_null()) {
182 return false;
183 }
184 return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass());
185 }
186
187 // ----------------------------------------------------------------------------
188 // Resolving of classes
189
190 // Forwards to resolve_or_null
191
192 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
193 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
194 if (HAS_PENDING_EXCEPTION || klass == NULL) {
195 KlassHandle k_h(THREAD, klass);
196 // can return a null klass
197 klass = handle_resolution_exception(class_name, throw_error, k_h, THREAD);
198 }
199 return klass;
200 }
201
202 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name,
203 bool throw_error,
204 KlassHandle klass_h, TRAPS) {
205 if (HAS_PENDING_EXCEPTION) {
206 // If we have a pending exception we forward it to the caller, unless throw_error is true,
207 // in which case we have to check whether the pending exception is a ClassNotFoundException,
208 // and if so convert it to a NoClassDefFoundError
209 // And chain the original ClassNotFoundException
210 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
211 ResourceMark rm(THREAD);
212 assert(klass_h() == NULL, "Should not have result with exception pending");
213 Handle e(THREAD, PENDING_EXCEPTION);
214 CLEAR_PENDING_EXCEPTION;
215 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
216 } else {
217 return NULL;
218 }
219 }
220 // Class not found, throw appropriate error or exception depending on value of throw_error
221 if (klass_h() == NULL) {
222 ResourceMark rm(THREAD);
223 if (throw_error) {
224 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
225 } else {
226 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
227 }
228 }
229 return (Klass*)klass_h();
230 }
231
232
233 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
234 bool throw_error, TRAPS)
235 {
236 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
237 }
238
239
240 // Forwards to resolve_instance_class_or_null
241
242 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
243 assert(THREAD->can_call_java(),
244 "can not load classes with compiler thread: class=%s, classloader=%s",
245 class_name->as_C_string(),
246 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string());
247 if (FieldType::is_array(class_name)) {
248 return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD);
249 } else if (FieldType::is_obj(class_name)) {
250 ResourceMark rm(THREAD);
251 // Ignore wrapping L and ;.
252 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
253 class_name->utf8_length() - 2, CHECK_NULL);
254 return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD);
255 } else {
256 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD);
257 }
258 }
259
260 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
261 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
262 }
263
264 // Forwards to resolve_instance_class_or_null
265
266 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
267 Handle class_loader,
268 Handle protection_domain,
269 TRAPS) {
270 assert(FieldType::is_array(class_name), "must be array");
271 Klass* k = NULL;
272 FieldArrayInfo fd;
273 // dimension and object_key in FieldArrayInfo are assigned as a side-effect
274 // of this call
275 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
276 if (t == T_OBJECT) {
277 // naked oop "k" is OK here -- we assign back into it
278 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
279 class_loader,
280 protection_domain,
281 CHECK_NULL);
282 if (k != NULL) {
283 k = k->array_klass(fd.dimension(), CHECK_NULL);
284 }
285 } else {
286 k = Universe::typeArrayKlassObj(t);
287 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
288 }
289 return k;
290 }
291
292
293 // Must be called for any super-class or super-interface resolution
294 // during class definition to allow class circularity checking
295 // super-interface callers:
296 // parse_interfaces - for defineClass & jvmtiRedefineClasses
297 // super-class callers:
298 // ClassFileParser - for defineClass & jvmtiRedefineClasses
299 // load_shared_class - while loading a class from shared archive
300 // resolve_instance_class_or_null:
301 // via: handle_parallel_super_load
302 // when resolving a class that has an existing placeholder with
303 // a saved superclass [i.e. a defineClass is currently in progress]
304 // if another thread is trying to resolve the class, it must do
305 // super-class checks on its own thread to catch class circularity
306 // This last call is critical in class circularity checking for cases
307 // where classloading is delegated to different threads and the
308 // classloader lock is released.
309 // Take the case: Base->Super->Base
310 // 1. If thread T1 tries to do a defineClass of class Base
311 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
312 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
313 // so it tries to load Super
314 // 3. If we load the class internally, or user classloader uses same thread
315 // loadClassFromxxx or defineClass via parseClassFile Super ...
316 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
317 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
318 // 3.4 calls resolve_super_or_fail Base
319 // 3.5 finds T1,Base -> throws class circularity
320 //OR 4. If T2 tries to resolve Super via defineClass Super ...
321 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
322 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
323 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
324 // 4.4 finds T2, Super -> throws class circularity
325 // Must be called, even if superclass is null, since this is
326 // where the placeholder entry is created which claims this
327 // thread is loading this class/classloader.
328 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
329 Symbol* class_name,
330 Handle class_loader,
331 Handle protection_domain,
332 bool is_superclass,
333 TRAPS) {
334 #if INCLUDE_CDS
335 if (DumpSharedSpaces) {
336 // Special processing for CDS dump time.
337 Klass* k = SystemDictionaryShared::dump_time_resolve_super_or_fail(child_name,
338 class_name, class_loader, protection_domain, is_superclass, CHECK_NULL);
339 if (k) {
340 return k;
341 }
342 }
343 #endif // INCLUDE_CDS
344
345 // Double-check, if child class is already loaded, just return super-class,interface
346 // Don't add a placedholder if already loaded, i.e. already in system dictionary
347 // Make sure there's a placeholder for the *child* before resolving.
348 // Used as a claim that this thread is currently loading superclass/classloader
349 // Used here for ClassCircularity checks and also for heap verification
350 // (every InstanceKlass in the heap needs to be in the system dictionary
351 // or have a placeholder).
352 // Must check ClassCircularity before checking if super class is already loaded
353 //
354 // We might not already have a placeholder if this child_name was
355 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
356 // the name of the class might not be known until the stream is actually
357 // parsed.
358 // Bugs 4643874, 4715493
359 // compute_hash can have a safepoint
360
361 ClassLoaderData* loader_data = class_loader_data(class_loader);
362 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
363 int d_index = dictionary()->hash_to_index(d_hash);
364 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
365 int p_index = placeholders()->hash_to_index(p_hash);
366 // can't throw error holding a lock
367 bool child_already_loaded = false;
368 bool throw_circularity_error = false;
369 {
370 MutexLocker mu(SystemDictionary_lock, THREAD);
371 Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
372 Klass* quicksuperk;
373 // to support // loading: if child done loading, just return superclass
374 // if class_name, & class_loader don't match:
375 // if initial define, SD update will give LinkageError
376 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
377 // so we don't throw an exception here.
378 // see: nsk redefclass014 & java.lang.instrument Instrument032
379 if ((childk != NULL ) && (is_superclass) &&
380 ((quicksuperk = childk->super()) != NULL) &&
381
382 ((quicksuperk->name() == class_name) &&
383 (quicksuperk->class_loader() == class_loader()))) {
384 return quicksuperk;
385 } else {
386 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
387 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
388 throw_circularity_error = true;
389 }
390 }
391 if (!throw_circularity_error) {
392 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
393 }
394 }
395 if (throw_circularity_error) {
396 ResourceMark rm(THREAD);
397 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
398 }
399
400 // java.lang.Object should have been found above
401 assert(class_name != NULL, "null super class for resolving");
402 // Resolve the super class or interface, check results on return
403 Klass* superk = SystemDictionary::resolve_or_null(class_name,
404 class_loader,
405 protection_domain,
406 THREAD);
407
408 KlassHandle superk_h(THREAD, superk);
409
410 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
411 // It is no longer necessary to keep the placeholder table alive until update_dictionary
412 // or error. GC used to walk the placeholder table as strong roots.
413 // The instanceKlass is kept alive because the class loader is on the stack,
414 // which keeps the loader_data alive, as well as all instanceKlasses in
415 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
416 {
417 MutexLocker mu(SystemDictionary_lock, THREAD);
418 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
419 SystemDictionary_lock->notify_all();
420 }
421 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
422 // can null superk
423 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, true, superk_h, THREAD));
424 }
425
426 return superk_h();
427 }
428
429 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
430 Handle class_loader,
431 Handle protection_domain,
432 TRAPS) {
433 if(!has_checkPackageAccess()) return;
434
435 // Now we have to call back to java to check if the initating class has access
436 JavaValue result(T_VOID);
437 if (log_is_enabled(Debug, protectiondomain)) {
438 ResourceMark rm;
439 // Print out trace information
440 outputStream* log = Log(protectiondomain)::debug_stream();
441 log->print_cr("Checking package access");
442 log->print("class loader: "); class_loader()->print_value_on(log);
443 log->print(" protection domain: "); protection_domain()->print_value_on(log);
444 log->print(" loading: "); klass()->print_value_on(log);
445 log->cr();
446 }
447
448 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass());
449 JavaCalls::call_special(&result,
450 class_loader,
451 system_loader,
452 vmSymbols::checkPackageAccess_name(),
453 vmSymbols::class_protectiondomain_signature(),
454 Handle(THREAD, klass->java_mirror()),
455 protection_domain,
456 THREAD);
457
458 if (HAS_PENDING_EXCEPTION) {
459 log_debug(protectiondomain)("DENIED !!!!!!!!!!!!!!!!!!!!!");
460 } else {
461 log_debug(protectiondomain)("granted");
462 }
463
464 if (HAS_PENDING_EXCEPTION) return;
465
466 // If no exception has been thrown, we have validated the protection domain
467 // Insert the protection domain of the initiating class into the set.
468 {
469 // We recalculate the entry here -- we've called out to java since
470 // the last time it was calculated.
471 ClassLoaderData* loader_data = class_loader_data(class_loader);
472
473 Symbol* kn = klass->name();
474 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
475 int d_index = dictionary()->hash_to_index(d_hash);
476
477 MutexLocker mu(SystemDictionary_lock, THREAD);
478 {
479 // Note that we have an entry, and entries can be deleted only during GC,
480 // so we cannot allow GC to occur while we're holding this entry.
481
482 // We're using a NoSafepointVerifier to catch any place where we
483 // might potentially do a GC at all.
484 // Dictionary::do_unloading() asserts that classes in SD are only
485 // unloaded at a safepoint. Anonymous classes are not in SD.
486 NoSafepointVerifier nosafepoint;
487 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
488 protection_domain, THREAD);
489 }
490 }
491 }
492
493 // We only get here if this thread finds that another thread
494 // has already claimed the placeholder token for the current operation,
495 // but that other thread either never owned or gave up the
496 // object lock
497 // Waits on SystemDictionary_lock to indicate placeholder table updated
498 // On return, caller must recheck placeholder table state
499 //
500 // We only get here if
501 // 1) custom classLoader, i.e. not bootstrap classloader
502 // 2) UnsyncloadClass not set
503 // 3) custom classLoader has broken the class loader objectLock
504 // so another thread got here in parallel
505 //
506 // lockObject must be held.
507 // Complicated dance due to lock ordering:
508 // Must first release the classloader object lock to
509 // allow initial definer to complete the class definition
510 // and to avoid deadlock
511 // Reclaim classloader lock object with same original recursion count
512 // Must release SystemDictionary_lock after notify, since
513 // class loader lock must be claimed before SystemDictionary_lock
514 // to prevent deadlocks
515 //
516 // The notify allows applications that did an untimed wait() on
517 // the classloader object lock to not hang.
518 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
519 assert_lock_strong(SystemDictionary_lock);
520
521 bool calledholdinglock
522 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
523 assert(calledholdinglock,"must hold lock for notify");
524 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
525 ObjectSynchronizer::notifyall(lockObject, THREAD);
526 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
527 SystemDictionary_lock->wait();
528 SystemDictionary_lock->unlock();
529 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
530 SystemDictionary_lock->lock();
531 }
532
533 // If the class in is in the placeholder table, class loading is in progress
534 // For cases where the application changes threads to load classes, it
535 // is critical to ClassCircularity detection that we try loading
536 // the superclass on the same thread internally, so we do parallel
537 // super class loading here.
538 // This also is critical in cases where the original thread gets stalled
539 // even in non-circularity situations.
540 // Note: must call resolve_super_or_fail even if null super -
541 // to force placeholder entry creation for this class for circularity detection
542 // Caller must check for pending exception
543 // Returns non-null Klass* if other thread has completed load
544 // and we are done,
545 // If return null Klass* and no pending exception, the caller must load the class
546 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
547 Symbol* name, Symbol* superclassname, Handle class_loader,
548 Handle protection_domain, Handle lockObject, TRAPS) {
549
550 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
551 ClassLoaderData* loader_data = class_loader_data(class_loader);
552 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
553 int d_index = dictionary()->hash_to_index(d_hash);
554 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
555 int p_index = placeholders()->hash_to_index(p_hash);
556
557 // superk is not used, resolve_super called for circularity check only
558 // This code is reached in two situations. One if this thread
559 // is loading the same class twice (e.g. ClassCircularity, or
560 // java.lang.instrument).
561 // The second is if another thread started the resolve_super first
562 // and has not yet finished.
563 // In both cases the original caller will clean up the placeholder
564 // entry on error.
565 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
566 superclassname,
567 class_loader,
568 protection_domain,
569 true,
570 CHECK_(nh));
571
572 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
573 // Serial class loaders and bootstrap classloader do wait for superclass loads
574 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
575 MutexLocker mu(SystemDictionary_lock, THREAD);
576 // Check if classloading completed while we were loading superclass or waiting
577 Klass* check = find_class(d_index, d_hash, name, loader_data);
578 if (check != NULL) {
579 // Klass is already loaded, so just return it
580 return(instanceKlassHandle(THREAD, check));
581 } else {
582 return nh;
583 }
584 }
585
586 // must loop to both handle other placeholder updates
587 // and spurious notifications
588 bool super_load_in_progress = true;
589 PlaceholderEntry* placeholder;
590 while (super_load_in_progress) {
591 MutexLocker mu(SystemDictionary_lock, THREAD);
592 // Check if classloading completed while we were loading superclass or waiting
593 Klass* check = find_class(d_index, d_hash, name, loader_data);
594 if (check != NULL) {
595 // Klass is already loaded, so just return it
596 return(instanceKlassHandle(THREAD, check));
597 } else {
598 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
599 if (placeholder && placeholder->super_load_in_progress() ){
600 // Before UnsyncloadClass:
601 // We only get here if the application has released the
602 // classloader lock when another thread was in the middle of loading a
603 // superclass/superinterface for this class, and now
604 // this thread is also trying to load this class.
605 // To minimize surprises, the first thread that started to
606 // load a class should be the one to complete the loading
607 // with the classfile it initially expected.
608 // This logic has the current thread wait once it has done
609 // all the superclass/superinterface loading it can, until
610 // the original thread completes the class loading or fails
611 // If it completes we will use the resulting InstanceKlass
612 // which we will find below in the systemDictionary.
613 // We also get here for parallel bootstrap classloader
614 if (class_loader.is_null()) {
615 SystemDictionary_lock->wait();
616 } else {
617 double_lock_wait(lockObject, THREAD);
618 }
619 } else {
620 // If not in SD and not in PH, other thread's load must have failed
621 super_load_in_progress = false;
622 }
623 }
624 }
625 return (nh);
626 }
627
628 // utility function for class load event
629 static void post_class_load_event(const Ticks& start_time,
630 instanceKlassHandle k,
631 Handle initiating_loader) {
632 #if INCLUDE_TRACE
633 EventClassLoad event(UNTIMED);
634 if (event.should_commit()) {
635 event.set_starttime(start_time);
636 event.set_loadedClass(k());
637 oop defining_class_loader = k->class_loader();
638 event.set_definingClassLoader(defining_class_loader != NULL ?
639 defining_class_loader->klass() : (Klass*)NULL);
640 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader();
641 event.set_initiatingClassLoader(class_loader != NULL ?
642 class_loader->klass() : (Klass*)NULL);
643 event.commit();
644 }
645 #endif // INCLUDE_TRACE
646 }
647
648 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
649 Handle class_loader,
650 Handle protection_domain,
651 TRAPS) {
652 assert(name != NULL && !FieldType::is_array(name) &&
653 !FieldType::is_obj(name), "invalid class name");
654
655 Ticks class_load_start_time = Ticks::now();
656
657 // Fix for 4474172; see evaluation for more details
658 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
659 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
660
661 // Do lookup to see if class already exist and the protection domain
662 // has the right access
663 // This call uses find which checks protection domain already matches
664 // All subsequent calls use find_class, and set has_loaded_class so that
665 // before we return a result we call out to java to check for valid protection domain
666 // to allow returning the Klass* and add it to the pd_set if it is valid
667 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
668 int d_index = dictionary()->hash_to_index(d_hash);
669 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
670 protection_domain, THREAD);
671 if (probe != NULL) return probe;
672
673
674 // Non-bootstrap class loaders will call out to class loader and
675 // define via jvm/jni_DefineClass which will acquire the
676 // class loader object lock to protect against multiple threads
677 // defining the class in parallel by accident.
678 // This lock must be acquired here so the waiter will find
679 // any successful result in the SystemDictionary and not attempt
680 // the define
681 // ParallelCapable Classloaders and the bootstrap classloader,
682 // or all classloaders with UnsyncloadClass do not acquire lock here
683 bool DoObjectLock = true;
684 if (is_parallelCapable(class_loader)) {
685 DoObjectLock = false;
686 }
687
688 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
689 int p_index = placeholders()->hash_to_index(p_hash);
690
691 // Class is not in SystemDictionary so we have to do loading.
692 // Make sure we are synchronized on the class loader before we proceed
693 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
694 check_loader_lock_contention(lockObject, THREAD);
695 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
696
697 // Check again (after locking) if class already exist in SystemDictionary
698 bool class_has_been_loaded = false;
699 bool super_load_in_progress = false;
700 bool havesupername = false;
701 instanceKlassHandle k;
702 PlaceholderEntry* placeholder;
703 Symbol* superclassname = NULL;
704
705 {
706 MutexLocker mu(SystemDictionary_lock, THREAD);
707 Klass* check = find_class(d_index, d_hash, name, loader_data);
708 if (check != NULL) {
709 // Klass is already loaded, so just return it
710 class_has_been_loaded = true;
711 k = instanceKlassHandle(THREAD, check);
712 } else {
713 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
714 if (placeholder && placeholder->super_load_in_progress()) {
715 super_load_in_progress = true;
716 if (placeholder->havesupername() == true) {
717 superclassname = placeholder->supername();
718 havesupername = true;
719 }
720 }
721 }
722 }
723
724 // If the class is in the placeholder table, class loading is in progress
725 if (super_load_in_progress && havesupername==true) {
726 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
727 class_loader, protection_domain, lockObject, THREAD);
728 if (HAS_PENDING_EXCEPTION) {
729 return NULL;
730 }
731 if (!k.is_null()) {
732 class_has_been_loaded = true;
733 }
734 }
735
736 bool throw_circularity_error = false;
737 if (!class_has_been_loaded) {
738 bool load_instance_added = false;
739
740 // add placeholder entry to record loading instance class
741 // Five cases:
742 // All cases need to prevent modifying bootclasssearchpath
743 // in parallel with a classload of same classname
744 // Redefineclasses uses existence of the placeholder for the duration
745 // of the class load to prevent concurrent redefinition of not completely
746 // defined classes.
747 // case 1. traditional classloaders that rely on the classloader object lock
748 // - no other need for LOAD_INSTANCE
749 // case 2. traditional classloaders that break the classloader object lock
750 // as a deadlock workaround. Detection of this case requires that
751 // this check is done while holding the classloader object lock,
752 // and that lock is still held when calling classloader's loadClass.
753 // For these classloaders, we ensure that the first requestor
754 // completes the load and other requestors wait for completion.
755 // case 3. UnsyncloadClass - don't use objectLocker
756 // With this flag, we allow parallel classloading of a
757 // class/classloader pair
758 // case4. Bootstrap classloader - don't own objectLocker
759 // This classloader supports parallelism at the classloader level,
760 // but only allows a single load of a class/classloader pair.
761 // No performance benefit and no deadlock issues.
762 // case 5. parallelCapable user level classloaders - without objectLocker
763 // Allow parallel classloading of a class/classloader pair
764
765 {
766 MutexLocker mu(SystemDictionary_lock, THREAD);
767 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
768 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
769 if (oldprobe) {
770 // only need check_seen_thread once, not on each loop
771 // 6341374 java/lang/Instrument with -Xcomp
772 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
773 throw_circularity_error = true;
774 } else {
775 // case 1: traditional: should never see load_in_progress.
776 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
777
778 // case 4: bootstrap classloader: prevent futile classloading,
779 // wait on first requestor
780 if (class_loader.is_null()) {
781 SystemDictionary_lock->wait();
782 } else {
783 // case 2: traditional with broken classloader lock. wait on first
784 // requestor.
785 double_lock_wait(lockObject, THREAD);
786 }
787 // Check if classloading completed while we were waiting
788 Klass* check = find_class(d_index, d_hash, name, loader_data);
789 if (check != NULL) {
790 // Klass is already loaded, so just return it
791 k = instanceKlassHandle(THREAD, check);
792 class_has_been_loaded = true;
793 }
794 // check if other thread failed to load and cleaned up
795 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
796 }
797 }
798 }
799 }
800 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
801 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
802 // LOAD_INSTANCE in parallel
803
804 if (!throw_circularity_error && !class_has_been_loaded) {
805 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
806 load_instance_added = true;
807 // For class loaders that do not acquire the classloader object lock,
808 // if they did not catch another thread holding LOAD_INSTANCE,
809 // need a check analogous to the acquire ObjectLocker/find_class
810 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
811 // one final check if the load has already completed
812 // class loaders holding the ObjectLock shouldn't find the class here
813 Klass* check = find_class(d_index, d_hash, name, loader_data);
814 if (check != NULL) {
815 // Klass is already loaded, so return it after checking/adding protection domain
816 k = instanceKlassHandle(THREAD, check);
817 class_has_been_loaded = true;
818 }
819 }
820 }
821
822 // must throw error outside of owning lock
823 if (throw_circularity_error) {
824 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
825 ResourceMark rm(THREAD);
826 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
827 }
828
829 if (!class_has_been_loaded) {
830
831 // Do actual loading
832 k = load_instance_class(name, class_loader, THREAD);
833
834 // For UnsyncloadClass only
835 // If they got a linkageError, check if a parallel class load succeeded.
836 // If it did, then for bytecode resolution the specification requires
837 // that we return the same result we did for the other thread, i.e. the
838 // successfully loaded InstanceKlass
839 // Should not get here for classloaders that support parallelism
840 // with the new cleaner mechanism, even with AllowParallelDefineClass
841 // Bootstrap goes through here to allow for an extra guarantee check
842 if (UnsyncloadClass || (class_loader.is_null())) {
843 if (k.is_null() && HAS_PENDING_EXCEPTION
844 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
845 MutexLocker mu(SystemDictionary_lock, THREAD);
846 Klass* check = find_class(d_index, d_hash, name, loader_data);
847 if (check != NULL) {
848 // Klass is already loaded, so just use it
849 k = instanceKlassHandle(THREAD, check);
850 CLEAR_PENDING_EXCEPTION;
851 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
852 }
853 }
854 }
855
856 // If everything was OK (no exceptions, no null return value), and
857 // class_loader is NOT the defining loader, do a little more bookkeeping.
858 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
859 k->class_loader() != class_loader()) {
860
861 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
862
863 // Need to check for a PENDING_EXCEPTION again; check_constraints
864 // can throw and doesn't use the CHECK macro.
865 if (!HAS_PENDING_EXCEPTION) {
866 { // Grabbing the Compile_lock prevents systemDictionary updates
867 // during compilations.
868 MutexLocker mu(Compile_lock, THREAD);
869 update_dictionary(d_index, d_hash, p_index, p_hash,
870 k, class_loader, THREAD);
871 }
872
873 if (JvmtiExport::should_post_class_load()) {
874 Thread *thread = THREAD;
875 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
876 JvmtiExport::post_class_load((JavaThread *) thread, k());
877 }
878 }
879 }
880 } // load_instance_class loop
881
882 if (load_instance_added == true) {
883 // clean up placeholder entries for LOAD_INSTANCE success or error
884 // This brackets the SystemDictionary updates for both defining
885 // and initiating loaders
886 MutexLocker mu(SystemDictionary_lock, THREAD);
887 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
888 SystemDictionary_lock->notify_all();
889 }
890 }
891
892 if (HAS_PENDING_EXCEPTION || k.is_null()) {
893 return NULL;
894 }
895
896 post_class_load_event(class_load_start_time, k, class_loader);
897
898 #ifdef ASSERT
899 {
900 ClassLoaderData* loader_data = k->class_loader_data();
901 MutexLocker mu(SystemDictionary_lock, THREAD);
902 Klass* kk = find_class(name, loader_data);
903 assert(kk == k(), "should be present in dictionary");
904 }
905 #endif
906
907 // return if the protection domain in NULL
908 if (protection_domain() == NULL) return k();
909
910 // Check the protection domain has the right access
911 {
912 MutexLocker mu(SystemDictionary_lock, THREAD);
913 // Note that we have an entry, and entries can be deleted only during GC,
914 // so we cannot allow GC to occur while we're holding this entry.
915 // We're using a NoSafepointVerifier to catch any place where we
916 // might potentially do a GC at all.
917 // Dictionary::do_unloading() asserts that classes in SD are only
918 // unloaded at a safepoint. Anonymous classes are not in SD.
919 NoSafepointVerifier nosafepoint;
920 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
921 loader_data,
922 protection_domain)) {
923 return k();
924 }
925 }
926
927 // Verify protection domain. If it fails an exception is thrown
928 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
929
930 return k();
931 }
932
933
934 // This routine does not lock the system dictionary.
935 //
936 // Since readers don't hold a lock, we must make sure that system
937 // dictionary entries are only removed at a safepoint (when only one
938 // thread is running), and are added to in a safe way (all links must
939 // be updated in an MT-safe manner).
940 //
941 // Callers should be aware that an entry could be added just after
942 // _dictionary->bucket(index) is read here, so the caller will not see
943 // the new entry.
944
945 Klass* SystemDictionary::find(Symbol* class_name,
946 Handle class_loader,
947 Handle protection_domain,
948 TRAPS) {
949
950 // The result of this call should be consistent with the result
951 // of the call to resolve_instance_class_or_null().
952 // See evaluation 6790209 and 4474172 for more details.
953 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
954 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
955
956 if (loader_data == NULL) {
957 // If the ClassLoaderData has not been setup,
958 // then the class loader has no entries in the dictionary.
959 return NULL;
960 }
961
962 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
963 int d_index = dictionary()->hash_to_index(d_hash);
964
965 {
966 // Note that we have an entry, and entries can be deleted only during GC,
967 // so we cannot allow GC to occur while we're holding this entry.
968 // We're using a NoSafepointVerifier to catch any place where we
969 // might potentially do a GC at all.
970 // Dictionary::do_unloading() asserts that classes in SD are only
971 // unloaded at a safepoint. Anonymous classes are not in SD.
972 NoSafepointVerifier nosafepoint;
973 return dictionary()->find(d_index, d_hash, class_name, loader_data,
974 protection_domain, THREAD);
975 }
976 }
977
978
979 // Look for a loaded instance or array klass by name. Do not do any loading.
980 // return NULL in case of error.
981 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
982 Handle class_loader,
983 Handle protection_domain,
984 TRAPS) {
985 Klass* k = NULL;
986 assert(class_name != NULL, "class name must be non NULL");
987
988 if (FieldType::is_array(class_name)) {
989 // The name refers to an array. Parse the name.
990 // dimension and object_key in FieldArrayInfo are assigned as a
991 // side-effect of this call
992 FieldArrayInfo fd;
993 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
994 if (t != T_OBJECT) {
995 k = Universe::typeArrayKlassObj(t);
996 } else {
997 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
998 }
999 if (k != NULL) {
1000 k = k->array_klass_or_null(fd.dimension());
1001 }
1002 } else {
1003 k = find(class_name, class_loader, protection_domain, THREAD);
1004 }
1005 return k;
1006 }
1007
1008 // Note: this method is much like resolve_from_stream, but
1009 // updates no supplemental data structures.
1010 // TODO consolidate the two methods with a helper routine?
1011 Klass* SystemDictionary::parse_stream(Symbol* class_name,
1012 Handle class_loader,
1013 Handle protection_domain,
1014 ClassFileStream* st,
1015 const Klass* host_klass,
1016 GrowableArray<Handle>* cp_patches,
1017 TRAPS) {
1018
1019 Ticks class_load_start_time = Ticks::now();
1020
1021 ClassLoaderData* loader_data;
1022 if (host_klass != NULL) {
1023 // Create a new CLD for anonymous class, that uses the same class loader
1024 // as the host_klass
1025 guarantee(host_klass->class_loader() == class_loader(), "should be the same");
1026 guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping");
1027 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
1028 loader_data->record_dependency(host_klass, CHECK_NULL);
1029 } else {
1030 loader_data = ClassLoaderData::class_loader_data(class_loader());
1031 }
1032
1033 assert(st != NULL, "invariant");
1034 assert(st->need_verify(), "invariant");
1035
1036 // Parse stream and create a klass.
1037 // Note that we do this even though this klass might
1038 // already be present in the SystemDictionary, otherwise we would not
1039 // throw potential ClassFormatErrors.
1040
1041 instanceKlassHandle k = KlassFactory::create_from_stream(st,
1042 class_name,
1043 loader_data,
1044 protection_domain,
1045 host_klass,
1046 cp_patches,
1047 NULL, // parsed_name
1048 THREAD);
1049
1050 if (host_klass != NULL && k.not_null()) {
1051 // If it's anonymous, initialize it now, since nobody else will.
1052
1053 {
1054 MutexLocker mu_r(Compile_lock, THREAD);
1055
1056 // Add to class hierarchy, initialize vtables, and do possible
1057 // deoptimizations.
1058 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1059
1060 // But, do not add to system dictionary.
1061
1062 // compiled code dependencies need to be validated anyway
1063 notice_modification();
1064 }
1065
1066 // Rewrite and patch constant pool here.
1067 k->link_class(CHECK_NULL);
1068 if (cp_patches != NULL) {
1069 k->constants()->patch_resolved_references(cp_patches);
1070 }
1071 k->eager_initialize(CHECK_NULL);
1072
1073 // notify jvmti
1074 if (JvmtiExport::should_post_class_load()) {
1075 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1076 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1077 }
1078
1079 post_class_load_event(class_load_start_time, k, class_loader);
1080 }
1081 assert(host_klass != NULL || NULL == cp_patches,
1082 "cp_patches only found with host_klass");
1083
1084 return k();
1085 }
1086
1087 // Add a klass to the system from a stream (called by jni_DefineClass and
1088 // JVM_DefineClass).
1089 // Note: class_name can be NULL. In that case we do not know the name of
1090 // the class until we have parsed the stream.
1091
1092 Klass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1093 Handle class_loader,
1094 Handle protection_domain,
1095 ClassFileStream* st,
1096 TRAPS) {
1097
1098 // Classloaders that support parallelism, e.g. bootstrap classloader,
1099 // or all classloaders with UnsyncloadClass do not acquire lock here
1100 bool DoObjectLock = true;
1101 if (is_parallelCapable(class_loader)) {
1102 DoObjectLock = false;
1103 }
1104
1105 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
1106
1107 // Make sure we are synchronized on the class loader before we proceed
1108 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1109 check_loader_lock_contention(lockObject, THREAD);
1110 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1111
1112 assert(st != NULL, "invariant");
1113
1114 // Parse the stream and create a klass.
1115 // Note that we do this even though this klass might
1116 // already be present in the SystemDictionary, otherwise we would not
1117 // throw potential ClassFormatErrors.
1118 //
1119 // Note: "parsed_name" is updated.
1120 TempNewSymbol parsed_name = NULL;
1121
1122 instanceKlassHandle k;
1123
1124 #if INCLUDE_CDS
1125 k = SystemDictionaryShared::lookup_from_stream(class_name,
1126 class_loader,
1127 protection_domain,
1128 st,
1129 CHECK_NULL);
1130 #endif
1131
1132 if (k.not_null()) {
1133 parsed_name = k->name();
1134 } else {
1135 if (st->buffer() == NULL) {
1136 return NULL;
1137 }
1138 k = KlassFactory::create_from_stream(st,
1139 class_name,
1140 loader_data,
1141 protection_domain,
1142 NULL, // host_klass
1143 NULL, // cp_patches
1144 &parsed_name,
1145 THREAD);
1146 }
1147
1148 const char* pkg = "java/";
1149 if (!HAS_PENDING_EXCEPTION &&
1150 !class_loader.is_null() &&
1151 !SystemDictionary::is_platform_class_loader(class_loader) &&
1152 parsed_name != NULL &&
1153 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
1154 // It is illegal to define classes in the "java." package from
1155 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
1156 ResourceMark rm(THREAD);
1157 char* name = parsed_name->as_C_string();
1158 char* index = strrchr(name, '/');
1159 *index = '\0'; // chop to just the package name
1160 while ((index = strchr(name, '/')) != NULL) {
1161 *index = '.'; // replace '/' with '.' in package name
1162 }
1163 const char* fmt = "Prohibited package name: %s";
1164 size_t len = strlen(fmt) + strlen(name);
1165 char* message = NEW_RESOURCE_ARRAY(char, len);
1166 jio_snprintf(message, len, fmt, name);
1167 Exceptions::_throw_msg(THREAD_AND_LOCATION,
1168 vmSymbols::java_lang_SecurityException(), message);
1169 }
1170
1171 if (!HAS_PENDING_EXCEPTION) {
1172 assert(parsed_name != NULL, "Sanity");
1173 assert(class_name == NULL || class_name == parsed_name, "name mismatch");
1174 // Verification prevents us from creating names with dots in them, this
1175 // asserts that that's the case.
1176 assert(is_internal_format(parsed_name),
1177 "external class name format used internally");
1178
1179 // Add class just loaded
1180 // If a class loader supports parallel classloading handle parallel define requests
1181 // find_or_define_instance_class may return a different InstanceKlass
1182 if (is_parallelCapable(class_loader)) {
1183 k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
1184 } else {
1185 define_instance_class(k, THREAD);
1186 }
1187 }
1188
1189 // Make sure we have an entry in the SystemDictionary on success
1190 debug_only( {
1191 if (!HAS_PENDING_EXCEPTION) {
1192 assert(parsed_name != NULL, "parsed_name is still null?");
1193 Symbol* h_name = k->name();
1194 ClassLoaderData *defining_loader_data = k->class_loader_data();
1195
1196 MutexLocker mu(SystemDictionary_lock, THREAD);
1197
1198 Klass* check = find_class(parsed_name, loader_data);
1199 assert(check == k(), "should be present in the dictionary");
1200
1201 Klass* check2 = find_class(h_name, defining_loader_data);
1202 assert(check == check2, "name inconsistancy in SystemDictionary");
1203 }
1204 } );
1205
1206 return k();
1207 }
1208
1209 #if INCLUDE_CDS
1210 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
1211 int number_of_entries) {
1212 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
1213 "bad shared dictionary size.");
1214 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1215 }
1216
1217
1218 // If there is a shared dictionary, then find the entry for the
1219 // given shared system class, if any.
1220
1221 Klass* SystemDictionary::find_shared_class(Symbol* class_name) {
1222 if (shared_dictionary() != NULL) {
1223 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
1224 int d_index = shared_dictionary()->hash_to_index(d_hash);
1225
1226 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1227 } else {
1228 return NULL;
1229 }
1230 }
1231
1232
1233 // Load a class from the shared spaces (found through the shared system
1234 // dictionary). Force the superclass and all interfaces to be loaded.
1235 // Update the class definition to include sibling classes and no
1236 // subclasses (yet). [Classes in the shared space are not part of the
1237 // object hierarchy until loaded.]
1238
1239 instanceKlassHandle SystemDictionary::load_shared_class(
1240 Symbol* class_name, Handle class_loader, TRAPS) {
1241 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
1242 // Make sure we only return the boot class for the NULL classloader.
1243 if (ik.not_null() &&
1244 ik->is_shared_boot_class() && class_loader.is_null()) {
1245 Handle protection_domain;
1246 return load_shared_class(ik, class_loader, protection_domain, THREAD);
1247 }
1248 return instanceKlassHandle();
1249 }
1250
1251 // Check if a shared class can be loaded by the specific classloader:
1252 //
1253 // NULL classloader:
1254 // - Module class from "modules" jimage. ModuleEntry must be defined in the classloader.
1255 // - Class from -Xbootclasspath/a. The class has no defined PackageEntry, or must
1256 // be defined in an unnamed module.
1257 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
1258 instanceKlassHandle ik,
1259 Handle class_loader, TRAPS) {
1260 int path_index = ik->shared_classpath_index();
1261 SharedClassPathEntry* ent =
1262 (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
1263 if (!Universe::is_module_initialized()) {
1264 assert(ent->is_jrt(),
1265 "Loading non-bootstrap classes before the module system is initialized");
1266 assert(class_loader.is_null(), "sanity");
1267 return true;
1268 }
1269 // Get the pkg_entry from the classloader
1270 TempNewSymbol pkg_name = NULL;
1271 PackageEntry* pkg_entry = NULL;
1272 ModuleEntry* mod_entry = NULL;
1273 int length = 0;
1274 ClassLoaderData* loader_data = class_loader_data(class_loader);
1275 const jbyte* pkg_string = InstanceKlass::package_from_name(class_name, length);
1276 if (pkg_string != NULL) {
1277 pkg_name = SymbolTable::new_symbol((const char*)pkg_string,
1278 length, CHECK_(false));
1279 if (loader_data != NULL) {
1280 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1281 }
1282 if (pkg_entry != NULL) {
1283 mod_entry = pkg_entry->module();
1284 }
1285 }
1286
1287 if (class_loader.is_null()) {
1288 // The NULL classloader can load archived class originated from the
1289 // "modules" jimage and the -Xbootclasspath/a. For class from the
1290 // "modules" jimage, the PackageEntry/ModuleEntry must be defined
1291 // by the NULL classloader.
1292 if (mod_entry != NULL) {
1293 // PackageEntry/ModuleEntry is found in the classloader. Check if the
1294 // ModuleEntry's location agrees with the archived class' origination.
1295 if (ent->is_jrt() && mod_entry->location()->starts_with("jrt:")) {
1296 return true; // Module class from the "module" jimage
1297 }
1298 }
1299
1300 // If the archived class is not from the "module" jimage, the class can be
1301 // loaded by the NULL classloader if
1302 //
1303 // 1. the class is from the unamed package
1304 // 2. or, the class is not from a module defined in the NULL classloader
1305 // 3. or, the class is from an unamed module
1306 if (!ent->is_jrt() && ik->is_shared_boot_class()) {
1307 // the class is from the -Xbootclasspath/a
1308 if (pkg_string == NULL ||
1309 pkg_entry == NULL ||
1310 pkg_entry->in_unnamed_module()) {
1311 assert(mod_entry == NULL ||
1312 mod_entry == loader_data->modules()->unnamed_module(),
1313 "the unnamed module is not defined in the classloader");
1314 return true;
1315 }
1316 }
1317 return false;
1318 } else {
1319 bool res = SystemDictionaryShared::is_shared_class_visible_for_classloader(
1320 ik, class_loader, pkg_string, pkg_name,
1321 pkg_entry, mod_entry, CHECK_(false));
1322 return res;
1323 }
1324 }
1325
1326 instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
1327 Handle class_loader,
1328 Handle protection_domain, TRAPS) {
1329 if (ik.not_null()) {
1330 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1331 Symbol* class_name = ik->name();
1332
1333 bool visible = is_shared_class_visible(
1334 class_name, ik, class_loader, CHECK_(nh));
1335 if (!visible) {
1336 return nh;
1337 }
1338
1339 // Found the class, now load the superclass and interfaces. If they
1340 // are shared, add them to the main system dictionary and reset
1341 // their hierarchy references (supers, subs, and interfaces).
1342
1343 if (ik->super() != NULL) {
1344 Symbol* cn = ik->super()->name();
1345 Klass *s = resolve_super_or_fail(class_name, cn,
1346 class_loader, protection_domain, true, CHECK_(nh));
1347 if (s != ik->super()) {
1348 // The dynamically resolved super class is not the same as the one we used during dump time,
1349 // so we cannot use ik.
1350 return nh;
1351 }
1352 }
1353
1354 Array<Klass*>* interfaces = ik->local_interfaces();
1355 int num_interfaces = interfaces->length();
1356 for (int index = 0; index < num_interfaces; index++) {
1357 Klass* k = interfaces->at(index);
1358
1359 // Note: can not use InstanceKlass::cast here because
1360 // interfaces' InstanceKlass's C++ vtbls haven't been
1361 // reinitialized yet (they will be once the interface classes
1362 // are loaded)
1363 Symbol* name = k->name();
1364 Klass* i = resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
1365 if (k != i) {
1366 // The dynamically resolved interface class is not the same as the one we used during dump time,
1367 // so we cannot use ik.
1368 return nh;
1369 }
1370 }
1371
1372 // Adjust methods to recover missing data. They need addresses for
1373 // interpreter entry points and their default native method address
1374 // must be reset.
1375
1376 // Updating methods must be done under a lock so multiple
1377 // threads don't update these in parallel
1378 //
1379 // Shared classes are all currently loaded by either the bootstrap or
1380 // internal parallel class loaders, so this will never cause a deadlock
1381 // on a custom class loader lock.
1382
1383 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1384 {
1385 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1386 check_loader_lock_contention(lockObject, THREAD);
1387 ObjectLocker ol(lockObject, THREAD, true);
1388 ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh));
1389 }
1390
1391 if (log_is_enabled(Info, classload)) {
1392 ik()->print_loading_log(LogLevel::Info, loader_data, NULL, NULL);
1393 }
1394 // No 'else' here as logging levels are not mutually exclusive
1395
1396 if (log_is_enabled(Debug, classload)) {
1397 ik()->print_loading_log(LogLevel::Debug, loader_data, NULL, NULL);
1398 }
1399
1400 // For boot loader, ensure that GetSystemPackage knows that a class in this
1401 // package was loaded.
1402 if (class_loader.is_null()) {
1403 int path_index = ik->shared_classpath_index();
1404 ResourceMark rm;
1405 ClassLoader::add_package(ik->name()->as_C_string(), path_index, THREAD);
1406 }
1407
1408 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1409 // Only dump the classes that can be stored into CDS archive
1410 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1411 ResourceMark rm(THREAD);
1412 classlist_file->print_cr("%s", ik->name()->as_C_string());
1413 classlist_file->flush();
1414 }
1415 }
1416
1417 // notify a class loaded from shared object
1418 ClassLoadingService::notify_class_loaded(ik(), true /* shared class */);
1419 }
1420 return ik;
1421 }
1422 #endif // INCLUDE_CDS
1423
1424 instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1425 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1426
1427 if (class_loader.is_null()) {
1428 int length = 0;
1429 PackageEntry* pkg_entry = NULL;
1430 bool search_only_bootloader_append = false;
1431 ClassLoaderData *loader_data = class_loader_data(class_loader);
1432
1433 // Find the package in the boot loader's package entry table.
1434 const jbyte* pkg_string = InstanceKlass::package_from_name(class_name, length);
1435 if (pkg_string != NULL) {
1436 TempNewSymbol pkg_name = SymbolTable::new_symbol((const char*)pkg_string, length, CHECK_(nh));
1437 pkg_entry = loader_data->packages()->lookup_only(pkg_name);
1438 }
1439
1440 // Prior to attempting to load the class, enforce the boot loader's
1441 // visibility boundaries.
1442 if (!Universe::is_module_initialized()) {
1443 // During bootstrapping, prior to module initialization, any
1444 // class attempting to be loaded must be checked against the
1445 // java.base packages in the boot loader's PackageEntryTable.
1446 // No class outside of java.base is allowed to be loaded during
1447 // this bootstrapping window.
1448 if (!DumpSharedSpaces) {
1449 if (pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1450 // Class is either in the unnamed package or in
1451 // a named package within the unnamed module. Either
1452 // case is outside of java.base, do not attempt to
1453 // load the class post java.base definition. If
1454 // java.base has not been defined, let the class load
1455 // and its package will be checked later by
1456 // ModuleEntryTable::verify_javabase_packages.
1457 if (ModuleEntryTable::javabase_defined()) {
1458 return nh;
1459 }
1460 } else {
1461 // Check that the class' package is defined within java.base.
1462 ModuleEntry* mod_entry = pkg_entry->module();
1463 Symbol* mod_entry_name = mod_entry->name();
1464 if (mod_entry_name->fast_compare(vmSymbols::java_base()) != 0) {
1465 return nh;
1466 }
1467 }
1468 }
1469 } else {
1470 assert(!DumpSharedSpaces, "Archive dumped after module system initialization");
1471 // After the module system has been initialized, check if the class'
1472 // package is in a module defined to the boot loader.
1473 if (pkg_string == NULL || pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
1474 // Class is either in the unnamed package, in a named package
1475 // within a module not defined to the boot loader or in a
1476 // a named package within the unnamed module. In all cases,
1477 // limit visibility to search for the class only in the boot
1478 // loader's append path.
1479 search_only_bootloader_append = true;
1480 }
1481 }
1482
1483 // Prior to bootstrapping's module initialization, never load a class outside
1484 // of the boot loader's module path
1485 assert(Universe::is_module_initialized() || DumpSharedSpaces ||
1486 !search_only_bootloader_append,
1487 "Attempt to load a class outside of boot loader's module path");
1488
1489 // Search the shared system dictionary for classes preloaded into the
1490 // shared spaces.
1491 instanceKlassHandle k;
1492 {
1493 #if INCLUDE_CDS
1494 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1495 k = load_shared_class(class_name, class_loader, THREAD);
1496 #endif
1497 }
1498
1499 if (k.is_null()) {
1500 // Use VM class loader
1501 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1502 k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_(nh));
1503 }
1504
1505 // find_or_define_instance_class may return a different InstanceKlass
1506 if (!k.is_null()) {
1507 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
1508 }
1509 return k;
1510 } else {
1511 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1512 ResourceMark rm(THREAD);
1513
1514 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1515 JavaThread* jt = (JavaThread*) THREAD;
1516
1517 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1518 ClassLoader::perf_app_classload_selftime(),
1519 ClassLoader::perf_app_classload_count(),
1520 jt->get_thread_stat()->perf_recursion_counts_addr(),
1521 jt->get_thread_stat()->perf_timers_addr(),
1522 PerfClassTraceTime::CLASS_LOAD);
1523
1524 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
1525 // Translate to external class name format, i.e., convert '/' chars to '.'
1526 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
1527
1528 JavaValue result(T_OBJECT);
1529
1530 KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass());
1531
1532 // Call public unsynchronized loadClass(String) directly for all class loaders
1533 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
1534 // acquire a class-name based lock rather than the class loader object lock.
1535 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
1536 // so the call to loadClassInternal() was not required.
1537 //
1538 // UnsyncloadClass flag means both call loadClass(String) and do
1539 // not acquire the class loader lock even for class loaders that are
1540 // not parallelCapable. This was a risky transitional
1541 // flag for diagnostic purposes only. It is risky to call
1542 // custom class loaders without synchronization.
1543 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1544 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
1545 // Do NOT assume this will be supported in future releases.
1546 //
1547 // Added MustCallLoadClassInternal in case we discover in the field
1548 // a customer that counts on this call
1549 if (MustCallLoadClassInternal && has_loadClassInternal()) {
1550 JavaCalls::call_special(&result,
1551 class_loader,
1552 spec_klass,
1553 vmSymbols::loadClassInternal_name(),
1554 vmSymbols::string_class_signature(),
1555 string,
1556 CHECK_(nh));
1557 } else {
1558 JavaCalls::call_virtual(&result,
1559 class_loader,
1560 spec_klass,
1561 vmSymbols::loadClass_name(),
1562 vmSymbols::string_class_signature(),
1563 string,
1564 CHECK_(nh));
1565 }
1566
1567 assert(result.get_type() == T_OBJECT, "just checking");
1568 oop obj = (oop) result.get_jobject();
1569
1570 // Primitive classes return null since forName() can not be
1571 // used to obtain any of the Class objects representing primitives or void
1572 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1573 instanceKlassHandle k =
1574 instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj));
1575 // For user defined Java class loaders, check that the name returned is
1576 // the same as that requested. This check is done for the bootstrap
1577 // loader when parsing the class file.
1578 if (class_name == k->name()) {
1579 return k;
1580 }
1581 }
1582 // Class is not found or has the wrong name, return NULL
1583 return nh;
1584 }
1585 }
1586
1587 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
1588
1589 ClassLoaderData* loader_data = k->class_loader_data();
1590 Handle class_loader_h(THREAD, loader_data->class_loader());
1591
1592 // for bootstrap and other parallel classloaders don't acquire lock,
1593 // use placeholder token
1594 // If a parallelCapable class loader calls define_instance_class instead of
1595 // find_or_define_instance_class to get here, we have a timing
1596 // hole with systemDictionary updates and check_constraints
1597 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1598 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1599 compute_loader_lock_object(class_loader_h, THREAD)),
1600 "define called without lock");
1601 }
1602
1603 // Check class-loading constraints. Throw exception if violation is detected.
1604 // Grabs and releases SystemDictionary_lock
1605 // The check_constraints/find_class call and update_dictionary sequence
1606 // must be "atomic" for a specific class/classloader pair so we never
1607 // define two different instanceKlasses for that class/classloader pair.
1608 // Existing classloaders will call define_instance_class with the
1609 // classloader lock held
1610 // Parallel classloaders will call find_or_define_instance_class
1611 // which will require a token to perform the define class
1612 Symbol* name_h = k->name();
1613 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1614 int d_index = dictionary()->hash_to_index(d_hash);
1615 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1616
1617 // Register class just loaded with class loader (placed in Vector)
1618 // Note we do this before updating the dictionary, as this can
1619 // fail with an OutOfMemoryError (if it does, we will *not* put this
1620 // class in the dictionary and will not update the class hierarchy).
1621 // JVMTI FollowReferences needs to find the classes this way.
1622 if (k->class_loader() != NULL) {
1623 methodHandle m(THREAD, Universe::loader_addClass_method());
1624 JavaValue result(T_VOID);
1625 JavaCallArguments args(class_loader_h);
1626 args.push_oop(Handle(THREAD, k->java_mirror()));
1627 JavaCalls::call(&result, m, &args, CHECK);
1628 }
1629
1630 // Add the new class. We need recompile lock during update of CHA.
1631 {
1632 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1633 int p_index = placeholders()->hash_to_index(p_hash);
1634
1635 MutexLocker mu_r(Compile_lock, THREAD);
1636
1637 // Add to class hierarchy, initialize vtables, and do possible
1638 // deoptimizations.
1639 add_to_hierarchy(k, CHECK); // No exception, but can block
1640
1641 // Add to systemDictionary - so other classes can see it.
1642 // Grabs and releases SystemDictionary_lock
1643 update_dictionary(d_index, d_hash, p_index, p_hash,
1644 k, class_loader_h, THREAD);
1645 }
1646 k->eager_initialize(THREAD);
1647
1648 // notify jvmti
1649 if (JvmtiExport::should_post_class_load()) {
1650 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1651 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1652
1653 }
1654
1655 TRACE_KLASS_DEFINITION(k, THREAD);
1656
1657 }
1658
1659 // Support parallel classloading
1660 // All parallel class loaders, including bootstrap classloader
1661 // lock a placeholder entry for this class/class_loader pair
1662 // to allow parallel defines of different classes for this class loader
1663 // With AllowParallelDefine flag==true, in case they do not synchronize around
1664 // FindLoadedClass/DefineClass, calls, we check for parallel
1665 // loading for them, wait if a defineClass is in progress
1666 // and return the initial requestor's results
1667 // This flag does not apply to the bootstrap classloader.
1668 // With AllowParallelDefine flag==false, call through to define_instance_class
1669 // which will throw LinkageError: duplicate class definition.
1670 // False is the requested default.
1671 // For better performance, the class loaders should synchronize
1672 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1673 // potentially waste time reading and parsing the bytestream.
1674 // Note: VM callers should ensure consistency of k/class_name,class_loader
1675 instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
1676
1677 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1678 Symbol* name_h = k->name(); // passed in class_name may be null
1679 ClassLoaderData* loader_data = class_loader_data(class_loader);
1680
1681 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1682 int d_index = dictionary()->hash_to_index(d_hash);
1683
1684 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1685 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1686 int p_index = placeholders()->hash_to_index(p_hash);
1687 PlaceholderEntry* probe;
1688
1689 {
1690 MutexLocker mu(SystemDictionary_lock, THREAD);
1691 // First check if class already defined
1692 if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
1693 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1694 if (check != NULL) {
1695 return(instanceKlassHandle(THREAD, check));
1696 }
1697 }
1698
1699 // Acquire define token for this class/classloader
1700 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1701 // Wait if another thread defining in parallel
1702 // All threads wait - even those that will throw duplicate class: otherwise
1703 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1704 // if other thread has not finished updating dictionary
1705 while (probe->definer() != NULL) {
1706 SystemDictionary_lock->wait();
1707 }
1708 // Only special cases allow parallel defines and can use other thread's results
1709 // Other cases fall through, and may run into duplicate defines
1710 // caught by finding an entry in the SystemDictionary
1711 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
1712 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1713 SystemDictionary_lock->notify_all();
1714 #ifdef ASSERT
1715 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1716 assert(check != NULL, "definer missed recording success");
1717 #endif
1718 return(instanceKlassHandle(THREAD, probe->instance_klass()));
1719 } else {
1720 // This thread will define the class (even if earlier thread tried and had an error)
1721 probe->set_definer(THREAD);
1722 }
1723 }
1724
1725 define_instance_class(k, THREAD);
1726
1727 Handle linkage_exception = Handle(); // null handle
1728
1729 // definer must notify any waiting threads
1730 {
1731 MutexLocker mu(SystemDictionary_lock, THREAD);
1732 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1733 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1734 if (probe != NULL) {
1735 if (HAS_PENDING_EXCEPTION) {
1736 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1737 CLEAR_PENDING_EXCEPTION;
1738 } else {
1739 probe->set_instance_klass(k());
1740 }
1741 probe->set_definer(NULL);
1742 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1743 SystemDictionary_lock->notify_all();
1744 }
1745 }
1746
1747 // Can't throw exception while holding lock due to rank ordering
1748 if (linkage_exception() != NULL) {
1749 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
1750 }
1751
1752 return k;
1753 }
1754 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1755 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1756 if (class_loader.is_null()) {
1757 return Handle(THREAD, _system_loader_lock_obj);
1758 } else {
1759 return class_loader;
1760 }
1761 }
1762
1763 // This method is added to check how often we have to wait to grab loader
1764 // lock. The results are being recorded in the performance counters defined in
1765 // ClassLoader::_sync_systemLoaderLockContentionRate and
1766 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1767 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1768 if (!UsePerfData) {
1769 return;
1770 }
1771
1772 assert(!loader_lock.is_null(), "NULL lock object");
1773
1774 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1775 == ObjectSynchronizer::owner_other) {
1776 // contention will likely happen, so increment the corresponding
1777 // contention counter.
1778 if (loader_lock() == _system_loader_lock_obj) {
1779 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1780 } else {
1781 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1782 }
1783 }
1784 }
1785
1786 // ----------------------------------------------------------------------------
1787 // Lookup
1788
1789 Klass* SystemDictionary::find_class(int index, unsigned int hash,
1790 Symbol* class_name,
1791 ClassLoaderData* loader_data) {
1792 assert_locked_or_safepoint(SystemDictionary_lock);
1793 assert (index == dictionary()->index_for(class_name, loader_data),
1794 "incorrect index?");
1795
1796 Klass* k = dictionary()->find_class(index, hash, class_name, loader_data);
1797 return k;
1798 }
1799
1800
1801 // Basic find on classes in the midst of being loaded
1802 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1803 ClassLoaderData* loader_data) {
1804 assert_locked_or_safepoint(SystemDictionary_lock);
1805 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
1806 int p_index = placeholders()->hash_to_index(p_hash);
1807 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1808 }
1809
1810
1811 // Used for assertions and verification only
1812 Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1813 #ifndef ASSERT
1814 guarantee(VerifyBeforeGC ||
1815 VerifyDuringGC ||
1816 VerifyBeforeExit ||
1817 VerifyDuringStartup ||
1818 VerifyAfterGC, "too expensive");
1819 #endif
1820 assert_locked_or_safepoint(SystemDictionary_lock);
1821
1822 // First look in the loaded class array
1823 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
1824 int d_index = dictionary()->hash_to_index(d_hash);
1825 return find_class(d_index, d_hash, class_name, loader_data);
1826 }
1827
1828
1829 // Get the next class in the dictionary.
1830 Klass* SystemDictionary::try_get_next_class() {
1831 return dictionary()->try_get_next_class();
1832 }
1833
1834
1835 // ----------------------------------------------------------------------------
1836 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1837 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1838 // before a new class is used.
1839
1840 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
1841 assert(k.not_null(), "just checking");
1842 assert_locked_or_safepoint(Compile_lock);
1843
1844 // Link into hierachy. Make sure the vtables are initialized before linking into
1845 k->append_to_sibling_list(); // add to superklass/sibling list
1846 k->process_interfaces(THREAD); // handle all "implements" declarations
1847 k->set_init_state(InstanceKlass::loaded);
1848 // Now flush all code that depended on old class hierarchy.
1849 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1850 // Also, first reinitialize vtable because it may have gotten out of synch
1851 // while the new class wasn't connected to the class hierarchy.
1852 CodeCache::flush_dependents_on(k);
1853 }
1854
1855 // ----------------------------------------------------------------------------
1856 // GC support
1857
1858 // Following roots during mark-sweep is separated in two phases.
1859 //
1860 // The first phase follows preloaded classes and all other system
1861 // classes, since these will never get unloaded anyway.
1862 //
1863 // The second phase removes (unloads) unreachable classes from the
1864 // system dictionary and follows the remaining classes' contents.
1865
1866 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1867 roots_oops_do(blk, NULL);
1868 }
1869
1870 void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
1871 // Follow all system classes and temporary placeholders in dictionary
1872 dictionary()->always_strong_classes_do(closure);
1873
1874 // Placeholders. These represent classes we're actively loading.
1875 placeholders()->classes_do(closure);
1876 }
1877
1878 // Calculate a "good" systemdictionary size based
1879 // on predicted or current loaded classes count
1880 int SystemDictionary::calculate_systemdictionary_size(int classcount) {
1881 int newsize = _old_default_sdsize;
1882 if ((classcount > 0) && !DumpSharedSpaces) {
1883 int desiredsize = classcount/_average_depth_goal;
1884 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
1885 newsize = _primelist[++_sdgeneration]) {
1886 if (desiredsize <= newsize) {
1887 break;
1888 }
1889 }
1890 }
1891 return newsize;
1892 }
1893
1894 #ifdef ASSERT
1895 class VerifySDReachableAndLiveClosure : public OopClosure {
1896 private:
1897 BoolObjectClosure* _is_alive;
1898
1899 template <class T> void do_oop_work(T* p) {
1900 oop obj = oopDesc::load_decode_heap_oop(p);
1901 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
1902 }
1903
1904 public:
1905 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
1906
1907 virtual void do_oop(oop* p) { do_oop_work(p); }
1908 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1909 };
1910 #endif
1911
1912 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1913 // Note: anonymous classes are not in the SD.
1914 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive,
1915 bool clean_previous_versions) {
1916 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1917 bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive,
1918 clean_previous_versions);
1919 if (unloading_occurred) {
1920 dictionary()->do_unloading();
1921 constraints()->purge_loader_constraints();
1922 resolution_errors()->purge_resolution_errors();
1923 }
1924 // Oops referenced by the system dictionary may get unreachable independently
1925 // of the class loader (eg. cached protection domain oops). So we need to
1926 // explicitly unlink them here instead of in Dictionary::do_unloading.
1927 dictionary()->unlink(is_alive);
1928 #ifdef ASSERT
1929 VerifySDReachableAndLiveClosure cl(is_alive);
1930 dictionary()->oops_do(&cl);
1931 #endif
1932 return unloading_occurred;
1933 }
1934
1935 void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
1936 strong->do_oop(&_java_system_loader);
1937 strong->do_oop(&_system_loader_lock_obj);
1938 CDS_ONLY(SystemDictionaryShared::roots_oops_do(strong);)
1939
1940 // Adjust dictionary
1941 dictionary()->roots_oops_do(strong, weak);
1942
1943 // Visit extra methods
1944 invoke_method_table()->oops_do(strong);
1945 }
1946
1947 void SystemDictionary::oops_do(OopClosure* f) {
1948 f->do_oop(&_java_system_loader);
1949 f->do_oop(&_system_loader_lock_obj);
1950 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1951
1952 // Adjust dictionary
1953 dictionary()->oops_do(f);
1954
1955 // Visit extra methods
1956 invoke_method_table()->oops_do(f);
1957 }
1958
1959 // Extended Class redefinition support.
1960 // If one of these classes is replaced, we need to replace it in these places.
1961 // KlassClosure::do_klass should take the address of a class but we can
1962 // change that later.
1963 void SystemDictionary::preloaded_classes_do(KlassClosure* f) {
1964 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
1965 f->do_klass(_well_known_klasses[k]);
1966 }
1967
1968 {
1969 for (int i = 0; i < T_VOID+1; i++) {
1970 if (_box_klasses[i] != NULL) {
1971 assert(i >= T_BOOLEAN, "checking");
1972 f->do_klass(_box_klasses[i]);
1973 }
1974 }
1975 }
1976
1977 FilteredFieldsMap::classes_do(f);
1978 }
1979
1980 void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) {
1981 f->do_klass(_abstract_ownable_synchronizer_klass);
1982 }
1983
1984 // Just the classes from defining class loaders
1985 // Don't iterate over placeholders
1986 void SystemDictionary::classes_do(void f(Klass*)) {
1987 dictionary()->classes_do(f);
1988 }
1989
1990 // Added for initialize_itable_for_klass
1991 // Just the classes from defining class loaders
1992 // Don't iterate over placeholders
1993 void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
1994 dictionary()->classes_do(f, CHECK);
1995 }
1996
1997 // All classes, and their class loaders
1998 // Don't iterate over placeholders
1999 void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
2000 dictionary()->classes_do(f);
2001 }
2002
2003 void SystemDictionary::placeholders_do(void f(Symbol*)) {
2004 placeholders()->entries_do(f);
2005 }
2006
2007 void SystemDictionary::methods_do(void f(Method*)) {
2008 dictionary()->methods_do(f);
2009 invoke_method_table()->methods_do(f);
2010 }
2011
2012 void SystemDictionary::remove_classes_in_error_state() {
2013 dictionary()->remove_classes_in_error_state();
2014 }
2015
2016 // ----------------------------------------------------------------------------
2017 // Lazily load klasses
2018
2019 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
2020 // if multiple threads calling this function, only one thread will load
2021 // the class. The other threads will find the loaded version once the
2022 // class is loaded.
2023 Klass* aos = _abstract_ownable_synchronizer_klass;
2024 if (aos == NULL) {
2025 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
2026 // Force a fence to prevent any read before the write completes
2027 OrderAccess::fence();
2028 _abstract_ownable_synchronizer_klass = InstanceKlass::cast(k);
2029 }
2030 }
2031
2032 // ----------------------------------------------------------------------------
2033 // Initialization
2034
2035 void SystemDictionary::initialize(TRAPS) {
2036 // Allocate arrays
2037 assert(dictionary() == NULL,
2038 "SystemDictionary should only be initialized once");
2039 _sdgeneration = 0;
2040 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
2041 _placeholders = new PlaceholderTable(_nof_buckets);
2042 _number_of_modifications = 0;
2043 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
2044 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
2045 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
2046
2047 // Allocate private object used as system class loader lock
2048 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
2049 // Initialize basic classes
2050 initialize_preloaded_classes(CHECK);
2051 }
2052
2053 // Compact table of directions on the initialization of klasses:
2054 static const short wk_init_info[] = {
2055 #define WK_KLASS_INIT_INFO(name, symbol, option) \
2056 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
2057 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
2058 | (int)SystemDictionary::option ),
2059 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
2060 #undef WK_KLASS_INIT_INFO
2061 0
2062 };
2063
2064 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
2065 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
2066 int info = wk_init_info[id - FIRST_WKID];
2067 int sid = (info >> CEIL_LG_OPTION_LIMIT);
2068 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
2069 InstanceKlass** klassp = &_well_known_klasses[id];
2070
2071 bool must_load;
2072 #if INCLUDE_JVMCI
2073 if (EnableJVMCI) {
2074 // If JVMCI is enabled we require its classes to be found.
2075 must_load = (init_opt < SystemDictionary::Opt) || (init_opt == SystemDictionary::Jvmci);
2076 } else
2077 #endif
2078 {
2079 must_load = (init_opt < SystemDictionary::Opt);
2080 }
2081
2082 if ((*klassp) == NULL) {
2083 Klass* k;
2084 if (must_load) {
2085 k = resolve_or_fail(symbol, true, CHECK_0); // load required class
2086 } else {
2087 k = resolve_or_null(symbol, CHECK_0); // load optional klass
2088 }
2089 (*klassp) = (k == NULL) ? NULL : InstanceKlass::cast(k);
2090 }
2091 return ((*klassp) != NULL);
2092 }
2093
2094 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
2095 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
2096 for (int id = (int)start_id; id < (int)limit_id; id++) {
2097 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
2098 int info = wk_init_info[id - FIRST_WKID];
2099 int sid = (info >> CEIL_LG_OPTION_LIMIT);
2100 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
2101
2102 initialize_wk_klass((WKID)id, opt, CHECK);
2103 }
2104
2105 // move the starting value forward to the limit:
2106 start_id = limit_id;
2107 }
2108
2109 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
2110 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
2111
2112 // Create the ModuleEntry for java.base. This call needs to be done here,
2113 // after vmSymbols::initialize() is called but before any classes are pre-loaded.
2114 ClassLoader::create_javabase();
2115
2116 // Preload commonly used klasses
2117 WKID scan = FIRST_WKID;
2118 // first do Object, then String, Class
2119 if (UseSharedSpaces) {
2120 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
2121 // Initialize the constant pool for the Object_class
2122 InstanceKlass* ik = InstanceKlass::cast(Object_klass());
2123 ik->constants()->restore_unshareable_info(CHECK);
2124 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2125 } else {
2126 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
2127 }
2128
2129 // Calculate offsets for String and Class classes since they are loaded and
2130 // can be used after this point.
2131 java_lang_String::compute_offsets();
2132 java_lang_Class::compute_offsets();
2133
2134 // Fixup mirrors for classes loaded before java.lang.Class.
2135 // These calls iterate over the objects currently in the perm gen
2136 // so calling them at this point is matters (not before when there
2137 // are fewer objects and not later after there are more objects
2138 // in the perm gen.
2139 Universe::initialize_basic_type_mirrors(CHECK);
2140 Universe::fixup_mirrors(CHECK);
2141
2142 // do a bunch more:
2143 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
2144
2145 // Preload ref klasses and set reference types
2146 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
2147 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
2148
2149 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
2150 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
2151 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
2152 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
2153 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
2154
2155 // JSR 292 classes
2156 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
2157 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
2158 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
2159 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
2160 initialize_wk_klasses_until(NOT_JVMCI(WKID_LIMIT) JVMCI_ONLY(FIRST_JVMCI_WKID), scan, CHECK);
2161
2162 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
2163 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
2164 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
2165 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
2166 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
2167 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
2168 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
2169 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
2170 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
2171 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
2172
2173 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
2174 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
2175 _has_loadClassInternal = (method != NULL);
2176 }
2177 { // Compute whether we should use checkPackageAccess or NOT
2178 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
2179 _has_checkPackageAccess = (method != NULL);
2180 }
2181 }
2182
2183 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
2184 // If so, returns the basic type it holds. If not, returns T_OBJECT.
2185 BasicType SystemDictionary::box_klass_type(Klass* k) {
2186 assert(k != NULL, "");
2187 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
2188 if (_box_klasses[i] == k)
2189 return (BasicType)i;
2190 }
2191 return T_OBJECT;
2192 }
2193
2194 // Constraints on class loaders. The details of the algorithm can be
2195 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
2196 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
2197 // that the system dictionary needs to maintain a set of contraints that
2198 // must be satisfied by all classes in the dictionary.
2199 // if defining is true, then LinkageError if already in systemDictionary
2200 // if initiating loader, then ok if InstanceKlass matches existing entry
2201
2202 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
2203 instanceKlassHandle k,
2204 Handle class_loader, bool defining,
2205 TRAPS) {
2206 const char *linkage_error1 = NULL;
2207 const char *linkage_error2 = NULL;
2208 {
2209 Symbol* name = k->name();
2210 ClassLoaderData *loader_data = class_loader_data(class_loader);
2211
2212 MutexLocker mu(SystemDictionary_lock, THREAD);
2213
2214 Klass* check = find_class(d_index, d_hash, name, loader_data);
2215 if (check != (Klass*)NULL) {
2216 // if different InstanceKlass - duplicate class definition,
2217 // else - ok, class loaded by a different thread in parallel,
2218 // we should only have found it if it was done loading and ok to use
2219 // system dictionary only holds instance classes, placeholders
2220 // also holds array classes
2221
2222 assert(check->is_instance_klass(), "noninstance in systemdictionary");
2223 if ((defining == true) || (k() != check)) {
2224 linkage_error1 = "loader (instance of ";
2225 linkage_error2 = "): attempted duplicate class definition for name: \"";
2226 } else {
2227 return;
2228 }
2229 }
2230
2231 #ifdef ASSERT
2232 Symbol* ph_check = find_placeholder(name, loader_data);
2233 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2234 #endif
2235
2236 if (linkage_error1 == NULL) {
2237 if (constraints()->check_or_update(k, class_loader, name) == false) {
2238 linkage_error1 = "loader constraint violation: loader (instance of ";
2239 linkage_error2 = ") previously initiated loading for a different type with name \"";
2240 }
2241 }
2242 }
2243
2244 // Throw error now if needed (cannot throw while holding
2245 // SystemDictionary_lock because of rank ordering)
2246
2247 if (linkage_error1) {
2248 ResourceMark rm(THREAD);
2249 const char* class_loader_name = loader_name(class_loader());
2250 char* type_name = k->name()->as_C_string();
2251 size_t buflen = strlen(linkage_error1) + strlen(class_loader_name) +
2252 strlen(linkage_error2) + strlen(type_name) + 2; // +2 for '"' and null byte.
2253 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
2254 jio_snprintf(buf, buflen, "%s%s%s%s\"", linkage_error1, class_loader_name, linkage_error2, type_name);
2255 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
2256 }
2257 }
2258
2259
2260 // Update system dictionary - done after check_constraint and add_to_hierachy
2261 // have been called.
2262 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
2263 int p_index, unsigned int p_hash,
2264 instanceKlassHandle k,
2265 Handle class_loader,
2266 TRAPS) {
2267 // Compile_lock prevents systemDictionary updates during compilations
2268 assert_locked_or_safepoint(Compile_lock);
2269 Symbol* name = k->name();
2270 ClassLoaderData *loader_data = class_loader_data(class_loader);
2271
2272 {
2273 MutexLocker mu1(SystemDictionary_lock, THREAD);
2274
2275 // See whether biased locking is enabled and if so set it for this
2276 // klass.
2277 // Note that this must be done past the last potential blocking
2278 // point / safepoint. We enable biased locking lazily using a
2279 // VM_Operation to iterate the SystemDictionary and installing the
2280 // biasable mark word into each InstanceKlass's prototype header.
2281 // To avoid race conditions where we accidentally miss enabling the
2282 // optimization for one class in the process of being added to the
2283 // dictionary, we must not safepoint after the test of
2284 // BiasedLocking::enabled().
2285 if (UseBiasedLocking && BiasedLocking::enabled()) {
2286 // Set biased locking bit for all loaded classes; it will be
2287 // cleared if revocation occurs too often for this type
2288 // NOTE that we must only do this when the class is initally
2289 // defined, not each time it is referenced from a new class loader
2290 if (k->class_loader() == class_loader()) {
2291 k->set_prototype_header(markOopDesc::biased_locking_prototype());
2292 }
2293 }
2294
2295 // Make a new system dictionary entry.
2296 Klass* sd_check = find_class(d_index, d_hash, name, loader_data);
2297 if (sd_check == NULL) {
2298 dictionary()->add_klass(name, loader_data, k);
2299 notice_modification();
2300 }
2301 #ifdef ASSERT
2302 sd_check = find_class(d_index, d_hash, name, loader_data);
2303 assert (sd_check != NULL, "should have entry in system dictionary");
2304 // Note: there may be a placeholder entry: for circularity testing
2305 // or for parallel defines
2306 #endif
2307 SystemDictionary_lock->notify_all();
2308 }
2309 }
2310
2311
2312 // Try to find a class name using the loader constraints. The
2313 // loader constraints might know about a class that isn't fully loaded
2314 // yet and these will be ignored.
2315 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2316 Symbol* class_name, Handle class_loader, TRAPS) {
2317
2318 // First see if it has been loaded directly.
2319 // Force the protection domain to be null. (This removes protection checks.)
2320 Handle no_protection_domain;
2321 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2322 no_protection_domain, CHECK_NULL);
2323 if (klass != NULL)
2324 return klass;
2325
2326 // Now look to see if it has been loaded elsewhere, and is subject to
2327 // a loader constraint that would require this loader to return the
2328 // klass that is already loaded.
2329 if (FieldType::is_array(class_name)) {
2330 // For array classes, their Klass*s are not kept in the
2331 // constraint table. The element Klass*s are.
2332 FieldArrayInfo fd;
2333 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
2334 if (t != T_OBJECT) {
2335 klass = Universe::typeArrayKlassObj(t);
2336 } else {
2337 MutexLocker mu(SystemDictionary_lock, THREAD);
2338 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
2339 }
2340 // If element class already loaded, allocate array klass
2341 if (klass != NULL) {
2342 klass = klass->array_klass_or_null(fd.dimension());
2343 }
2344 } else {
2345 MutexLocker mu(SystemDictionary_lock, THREAD);
2346 // Non-array classes are easy: simply check the constraint table.
2347 klass = constraints()->find_constrained_klass(class_name, class_loader);
2348 }
2349
2350 return klass;
2351 }
2352
2353
2354 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2355 Handle class_loader1,
2356 Handle class_loader2,
2357 Thread* THREAD) {
2358 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2359 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2360
2361 Symbol* constraint_name = NULL;
2362 if (!FieldType::is_array(class_name)) {
2363 constraint_name = class_name;
2364 } else {
2365 // For array classes, their Klass*s are not kept in the
2366 // constraint table. The element classes are.
2367 FieldArrayInfo fd;
2368 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
2369 // primitive types always pass
2370 if (t != T_OBJECT) {
2371 return true;
2372 } else {
2373 constraint_name = fd.object_key();
2374 }
2375 }
2376 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
2377 int d_index1 = dictionary()->hash_to_index(d_hash1);
2378
2379 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
2380 int d_index2 = dictionary()->hash_to_index(d_hash2);
2381 {
2382 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2383
2384 // Better never do a GC while we're holding these oops
2385 NoSafepointVerifier nosafepoint;
2386
2387 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
2388 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
2389 return constraints()->add_entry(constraint_name, klass1, class_loader1,
2390 klass2, class_loader2);
2391 }
2392 }
2393
2394 // Add entry to resolution error table to record the error when the first
2395 // attempt to resolve a reference to a class has failed.
2396 void SystemDictionary::add_resolution_error(const constantPoolHandle& pool, int which,
2397 Symbol* error, Symbol* message) {
2398 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2399 int index = resolution_errors()->hash_to_index(hash);
2400 {
2401 MutexLocker ml(SystemDictionary_lock, Thread::current());
2402 resolution_errors()->add_entry(index, hash, pool, which, error, message);
2403 }
2404 }
2405
2406 // Delete a resolution error for RedefineClasses for a constant pool is going away
2407 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2408 resolution_errors()->delete_entry(pool);
2409 }
2410
2411 // Lookup resolution error table. Returns error if found, otherwise NULL.
2412 Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool, int which,
2413 Symbol** message) {
2414 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2415 int index = resolution_errors()->hash_to_index(hash);
2416 {
2417 MutexLocker ml(SystemDictionary_lock, Thread::current());
2418 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2419 if (entry != NULL) {
2420 *message = entry->message();
2421 return entry->error();
2422 } else {
2423 return NULL;
2424 }
2425 }
2426 }
2427
2428
2429 // Signature constraints ensure that callers and callees agree about
2430 // the meaning of type names in their signatures. This routine is the
2431 // intake for constraints. It collects them from several places:
2432 //
2433 // * LinkResolver::resolve_method (if check_access is true) requires
2434 // that the resolving class (the caller) and the defining class of
2435 // the resolved method (the callee) agree on each type in the
2436 // method's signature.
2437 //
2438 // * LinkResolver::resolve_interface_method performs exactly the same
2439 // checks.
2440 //
2441 // * LinkResolver::resolve_field requires that the constant pool
2442 // attempting to link to a field agree with the field's defining
2443 // class about the type of the field signature.
2444 //
2445 // * klassVtable::initialize_vtable requires that, when a class
2446 // overrides a vtable entry allocated by a superclass, that the
2447 // overriding method (i.e., the callee) agree with the superclass
2448 // on each type in the method's signature.
2449 //
2450 // * klassItable::initialize_itable requires that, when a class fills
2451 // in its itables, for each non-abstract method installed in an
2452 // itable, the method (i.e., the callee) agree with the interface
2453 // on each type in the method's signature.
2454 //
2455 // All those methods have a boolean (check_access, checkconstraints)
2456 // which turns off the checks. This is used from specialized contexts
2457 // such as bootstrapping, dumping, and debugging.
2458 //
2459 // No direct constraint is placed between the class and its
2460 // supertypes. Constraints are only placed along linked relations
2461 // between callers and callees. When a method overrides or implements
2462 // an abstract method in a supertype (superclass or interface), the
2463 // constraints are placed as if the supertype were the caller to the
2464 // overriding method. (This works well, since callers to the
2465 // supertype have already established agreement between themselves and
2466 // the supertype.) As a result of all this, a class can disagree with
2467 // its supertype about the meaning of a type name, as long as that
2468 // class neither calls a relevant method of the supertype, nor is
2469 // called (perhaps via an override) from the supertype.
2470 //
2471 //
2472 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2473 //
2474 // Make sure all class components (including arrays) in the given
2475 // signature will be resolved to the same class in both loaders.
2476 // Returns the name of the type that failed a loader constraint check, or
2477 // NULL if no constraint failed. No exception except OOME is thrown.
2478 // Arrays are not added to the loader constraint table, their elements are.
2479 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2480 Handle loader1, Handle loader2,
2481 bool is_method, TRAPS) {
2482 // Nothing to do if loaders are the same.
2483 if (loader1() == loader2()) {
2484 return NULL;
2485 }
2486
2487 SignatureStream sig_strm(signature, is_method);
2488 while (!sig_strm.is_done()) {
2489 if (sig_strm.is_object()) {
2490 Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
2491 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2492 return sig;
2493 }
2494 }
2495 sig_strm.next();
2496 }
2497 return NULL;
2498 }
2499
2500
2501 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2502 Symbol* signature,
2503 TRAPS) {
2504 methodHandle empty;
2505 assert(MethodHandles::is_signature_polymorphic(iid) &&
2506 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2507 iid != vmIntrinsics::_invokeGeneric,
2508 "must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid));
2509
2510 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2511 int index = invoke_method_table()->hash_to_index(hash);
2512 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2513 methodHandle m;
2514 if (spe == NULL || spe->method() == NULL) {
2515 spe = NULL;
2516 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2517 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
2518 if (!Arguments::is_interpreter_only()) {
2519 // Generate a compiled form of the MH intrinsic.
2520 AdapterHandlerLibrary::create_native_wrapper(m);
2521 // Check if have the compiled code.
2522 if (!m->has_compiled_code()) {
2523 THROW_MSG_(vmSymbols::java_lang_VirtualMachineError(),
2524 "Out of space in CodeCache for method handle intrinsic", empty);
2525 }
2526 }
2527 // Now grab the lock. We might have to throw away the new method,
2528 // if a racing thread has managed to install one at the same time.
2529 {
2530 MutexLocker ml(SystemDictionary_lock, THREAD);
2531 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2532 if (spe == NULL)
2533 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2534 if (spe->method() == NULL)
2535 spe->set_method(m());
2536 }
2537 }
2538
2539 assert(spe != NULL && spe->method() != NULL, "");
2540 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2541 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2542 "MH intrinsic invariant");
2543 return spe->method();
2544 }
2545
2546 // Helper for unpacking the return value from linkMethod and linkCallSite.
2547 static methodHandle unpack_method_and_appendix(Handle mname,
2548 KlassHandle accessing_klass,
2549 objArrayHandle appendix_box,
2550 Handle* appendix_result,
2551 TRAPS) {
2552 methodHandle empty;
2553 if (mname.not_null()) {
2554 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
2555 if (vmtarget != NULL && vmtarget->is_method()) {
2556 Method* m = (Method*)vmtarget;
2557 oop appendix = appendix_box->obj_at(0);
2558 if (TraceMethodHandles) {
2559 #ifndef PRODUCT
2560 ttyLocker ttyl;
2561 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2562 m->print();
2563 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2564 tty->cr();
2565 #endif //PRODUCT
2566 }
2567 (*appendix_result) = Handle(THREAD, appendix);
2568 // the target is stored in the cpCache and if a reference to this
2569 // MethodName is dropped we need a way to make sure the
2570 // class_loader containing this method is kept alive.
2571 // FIXME: the appendix might also preserve this dependency.
2572 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data();
2573 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
2574 return methodHandle(THREAD, m);
2575 }
2576 }
2577 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
2578 return empty;
2579 }
2580
2581 methodHandle SystemDictionary::find_method_handle_invoker(KlassHandle klass,
2582 Symbol* name,
2583 Symbol* signature,
2584 KlassHandle accessing_klass,
2585 Handle *appendix_result,
2586 Handle *method_type_result,
2587 TRAPS) {
2588 methodHandle empty;
2589 assert(THREAD->can_call_java() ,"");
2590 Handle method_type =
2591 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
2592
2593 int ref_kind = JVM_REF_invokeVirtual;
2594 Handle name_str = StringTable::intern(name, CHECK_(empty));
2595 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2596 assert(appendix_box->obj_at(0) == NULL, "");
2597
2598 // This should not happen. JDK code should take care of that.
2599 if (accessing_klass.is_null() || method_type.is_null()) {
2600 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
2601 }
2602
2603 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2604 JavaCallArguments args;
2605 args.push_oop(accessing_klass()->java_mirror());
2606 args.push_int(ref_kind);
2607 args.push_oop(klass()->java_mirror());
2608 args.push_oop(name_str());
2609 args.push_oop(method_type());
2610 args.push_oop(appendix_box());
2611 JavaValue result(T_OBJECT);
2612 JavaCalls::call_static(&result,
2613 SystemDictionary::MethodHandleNatives_klass(),
2614 vmSymbols::linkMethod_name(),
2615 vmSymbols::linkMethod_signature(),
2616 &args, CHECK_(empty));
2617 Handle mname(THREAD, (oop) result.get_jobject());
2618 (*method_type_result) = method_type;
2619 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2620 }
2621
2622 // Decide if we can globally cache a lookup of this class, to be returned to any client that asks.
2623 // We must ensure that all class loaders everywhere will reach this class, for any client.
2624 // This is a safe bet for public classes in java.lang, such as Object and String.
2625 // We also include public classes in java.lang.invoke, because they appear frequently in system-level method types.
2626 // Out of an abundance of caution, we do not include any other classes, not even for packages like java.util.
2627 static bool is_always_visible_class(oop mirror) {
2628 Klass* klass = java_lang_Class::as_Klass(mirror);
2629 if (klass->is_objArray_klass()) {
2630 klass = ObjArrayKlass::cast(klass)->bottom_klass(); // check element type
2631 }
2632 if (klass->is_typeArray_klass()) {
2633 return true; // primitive array
2634 }
2635 assert(klass->is_instance_klass(), "%s", klass->external_name());
2636 return klass->is_public() &&
2637 (InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::Object_klass()) || // java.lang
2638 InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::MethodHandle_klass())); // java.lang.invoke
2639 }
2640
2641 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2642 // signature, as interpreted relative to the given class loader.
2643 // Because of class loader constraints, all method handle usage must be
2644 // consistent with this loader.
2645 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2646 KlassHandle accessing_klass,
2647 TRAPS) {
2648 Handle empty;
2649 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2650 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2651 int index = invoke_method_table()->hash_to_index(hash);
2652 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2653 if (spe != NULL && spe->method_type() != NULL) {
2654 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2655 return Handle(THREAD, spe->method_type());
2656 } else if (!THREAD->can_call_java()) {
2657 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2658 return Handle(); // do not attempt from within compiler, unless it was cached
2659 }
2660
2661 Handle class_loader, protection_domain;
2662 if (accessing_klass.not_null()) {
2663 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader());
2664 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain());
2665 }
2666 bool can_be_cached = true;
2667 int npts = ArgumentCount(signature).size();
2668 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2669 int arg = 0;
2670 Handle rt; // the return type from the signature
2671 ResourceMark rm(THREAD);
2672 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2673 oop mirror = NULL;
2674 if (can_be_cached) {
2675 // Use neutral class loader to lookup candidate classes to be placed in the cache.
2676 mirror = ss.as_java_mirror(Handle(), Handle(),
2677 SignatureStream::ReturnNull, CHECK_(empty));
2678 if (mirror == NULL || (ss.is_object() && !is_always_visible_class(mirror))) {
2679 // Fall back to accessing_klass context.
2680 can_be_cached = false;
2681 }
2682 }
2683 if (!can_be_cached) {
2684 // Resolve, throwing a real error if it doesn't work.
2685 mirror = ss.as_java_mirror(class_loader, protection_domain,
2686 SignatureStream::NCDFError, CHECK_(empty));
2687 }
2688 assert(!oopDesc::is_null(mirror), "%s", ss.as_symbol(THREAD)->as_C_string());
2689 if (ss.at_return_type())
2690 rt = Handle(THREAD, mirror);
2691 else
2692 pts->obj_at_put(arg++, mirror);
2693
2694 // Check accessibility.
2695 if (ss.is_object() && accessing_klass.not_null()) {
2696 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2697 mirror = NULL; // safety
2698 // Emulate ConstantPool::verify_constant_pool_resolve.
2699 if (sel_klass->is_objArray_klass())
2700 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
2701 if (sel_klass->is_instance_klass()) {
2702 KlassHandle sel_kh(THREAD, sel_klass);
2703 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty));
2704 }
2705 }
2706 }
2707 assert(arg == npts, "");
2708
2709 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType
2710 JavaCallArguments args(Handle(THREAD, rt()));
2711 args.push_oop(pts());
2712 JavaValue result(T_OBJECT);
2713 JavaCalls::call_static(&result,
2714 SystemDictionary::MethodHandleNatives_klass(),
2715 vmSymbols::findMethodHandleType_name(),
2716 vmSymbols::findMethodHandleType_signature(),
2717 &args, CHECK_(empty));
2718 Handle method_type(THREAD, (oop) result.get_jobject());
2719
2720 if (can_be_cached) {
2721 // We can cache this MethodType inside the JVM.
2722 MutexLocker ml(SystemDictionary_lock, THREAD);
2723 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2724 if (spe == NULL)
2725 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2726 if (spe->method_type() == NULL) {
2727 spe->set_method_type(method_type());
2728 }
2729 }
2730
2731 // report back to the caller with the MethodType
2732 return method_type;
2733 }
2734
2735 // Ask Java code to find or construct a method handle constant.
2736 Handle SystemDictionary::link_method_handle_constant(KlassHandle caller,
2737 int ref_kind, //e.g., JVM_REF_invokeVirtual
2738 KlassHandle callee,
2739 Symbol* name_sym,
2740 Symbol* signature,
2741 TRAPS) {
2742 Handle empty;
2743 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
2744 Handle type;
2745 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
2746 type = find_method_handle_type(signature, caller, CHECK_(empty));
2747 } else if (caller.is_null()) {
2748 // This should not happen. JDK code should take care of that.
2749 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2750 } else {
2751 ResourceMark rm(THREAD);
2752 SignatureStream ss(signature, false);
2753 if (!ss.is_done()) {
2754 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(),
2755 SignatureStream::NCDFError, CHECK_(empty));
2756 type = Handle(THREAD, mirror);
2757 ss.next();
2758 if (!ss.is_done()) type = Handle(); // error!
2759 }
2760 }
2761 if (type.is_null()) {
2762 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
2763 }
2764
2765 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2766 JavaCallArguments args;
2767 args.push_oop(caller->java_mirror()); // the referring class
2768 args.push_int(ref_kind);
2769 args.push_oop(callee->java_mirror()); // the target class
2770 args.push_oop(name());
2771 args.push_oop(type());
2772 JavaValue result(T_OBJECT);
2773 JavaCalls::call_static(&result,
2774 SystemDictionary::MethodHandleNatives_klass(),
2775 vmSymbols::linkMethodHandleConstant_name(),
2776 vmSymbols::linkMethodHandleConstant_signature(),
2777 &args, CHECK_(empty));
2778 return Handle(THREAD, (oop) result.get_jobject());
2779 }
2780
2781 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given
2782 // name and signature, as interpreted relative to the given class loader.
2783 methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller,
2784 Handle bootstrap_specifier,
2785 Symbol* name,
2786 Symbol* type,
2787 Handle *appendix_result,
2788 Handle *method_type_result,
2789 TRAPS) {
2790 methodHandle empty;
2791 Handle bsm, info;
2792 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
2793 bsm = bootstrap_specifier;
2794 } else {
2795 assert(bootstrap_specifier->is_objArray(), "");
2796 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
2797 int len = args->length();
2798 assert(len >= 1, "");
2799 bsm = Handle(THREAD, args->obj_at(0));
2800 if (len > 1) {
2801 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
2802 for (int i = 1; i < len; i++)
2803 args1->obj_at_put(i-1, args->obj_at(i));
2804 info = Handle(THREAD, args1);
2805 }
2806 }
2807 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
2808 "caller must supply a valid BSM");
2809
2810 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
2811 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
2812
2813 // This should not happen. JDK code should take care of that.
2814 if (caller.is_null() || method_type.is_null()) {
2815 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
2816 }
2817
2818 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2819 assert(appendix_box->obj_at(0) == NULL, "");
2820
2821 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
2822 JavaCallArguments args;
2823 args.push_oop(caller->java_mirror());
2824 args.push_oop(bsm());
2825 args.push_oop(method_name());
2826 args.push_oop(method_type());
2827 args.push_oop(info());
2828 args.push_oop(appendix_box);
2829 JavaValue result(T_OBJECT);
2830 JavaCalls::call_static(&result,
2831 SystemDictionary::MethodHandleNatives_klass(),
2832 vmSymbols::linkCallSite_name(),
2833 vmSymbols::linkCallSite_signature(),
2834 &args, CHECK_(empty));
2835 Handle mname(THREAD, (oop) result.get_jobject());
2836 (*method_type_result) = method_type;
2837 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
2838 }
2839
2840 // Since the identity hash code for symbols changes when the symbols are
2841 // moved from the regular perm gen (hash in the mark word) to the shared
2842 // spaces (hash is the address), the classes loaded into the dictionary
2843 // may be in the wrong buckets.
2844
2845 void SystemDictionary::reorder_dictionary() {
2846 dictionary()->reorder_dictionary();
2847 }
2848
2849
2850 void SystemDictionary::copy_buckets(char** top, char* end) {
2851 dictionary()->copy_buckets(top, end);
2852 }
2853
2854
2855 void SystemDictionary::copy_table(char** top, char* end) {
2856 dictionary()->copy_table(top, end);
2857 }
2858
2859
2860 void SystemDictionary::reverse() {
2861 dictionary()->reverse();
2862 }
2863
2864 int SystemDictionary::number_of_classes() {
2865 return dictionary()->number_of_entries();
2866 }
2867
2868
2869 // ----------------------------------------------------------------------------
2870 void SystemDictionary::print_shared(bool details) {
2871 shared_dictionary()->print(details);
2872 }
2873
2874 void SystemDictionary::print(bool details) {
2875 dictionary()->print(details);
2876
2877 // Placeholders
2878 GCMutexLocker mu(SystemDictionary_lock);
2879 placeholders()->print();
2880
2881 // loader constraints - print under SD_lock
2882 constraints()->print();
2883 }
2884
2885
2886 void SystemDictionary::verify() {
2887 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2888 guarantee(constraints() != NULL,
2889 "Verify of loader constraints failed");
2890 guarantee(dictionary()->number_of_entries() >= 0 &&
2891 placeholders()->number_of_entries() >= 0,
2892 "Verify of system dictionary failed");
2893
2894 // Verify dictionary
2895 dictionary()->verify();
2896
2897 GCMutexLocker mu(SystemDictionary_lock);
2898 placeholders()->verify();
2899
2900 // Verify constraint table
2901 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2902 constraints()->verify(dictionary(), placeholders());
2903 }
2904
2905 // caller needs ResourceMark
2906 const char* SystemDictionary::loader_name(const oop loader) {
2907 return ((loader) == NULL ? "<bootloader>" :
2908 InstanceKlass::cast((loader)->klass())->name()->as_C_string());
2909 }
2910
2911 // caller needs ResourceMark
2912 const char* SystemDictionary::loader_name(const ClassLoaderData* loader_data) {
2913 return (loader_data->class_loader() == NULL ? "<bootloader>" :
2914 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string());
2915 }