1 /*
2 * Copyright (c) 1997, 2014, 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/classLoaderData.inline.hpp"
27 #include "classfile/dictionary.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "classfile/loaderConstraints.hpp"
30 #include "classfile/placeholders.hpp"
31 #include "classfile/resolutionErrors.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #if INCLUDE_CDS
34 #include "classfile/sharedClassUtil.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #endif
37 #include "classfile/vmSymbols.hpp"
38 #include "compiler/compileBroker.hpp"
39 #include "interpreter/bytecodeStream.hpp"
40 #include "interpreter/interpreter.hpp"
41 #include "memory/filemap.hpp"
42 #include "memory/gcLocker.hpp"
43 #include "memory/oopFactory.hpp"
44 #include "oops/instanceKlass.hpp"
45 #include "oops/instanceRefKlass.hpp"
46 #include "oops/klass.inline.hpp"
47 #include "oops/methodData.hpp"
48 #include "oops/objArrayKlass.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "oops/oop.inline2.hpp"
51 #include "oops/typeArrayKlass.hpp"
52 #include "prims/jvmtiEnvBase.hpp"
53 #include "prims/methodHandles.hpp"
54 #include "runtime/arguments.hpp"
55 #include "runtime/biasedLocking.hpp"
56 #include "runtime/fieldType.hpp"
57 #include "runtime/handles.inline.hpp"
58 #include "runtime/java.hpp"
59 #include "runtime/javaCalls.hpp"
60 #include "runtime/mutexLocker.hpp"
61 #include "runtime/orderAccess.inline.hpp"
62 #include "runtime/signature.hpp"
63 #include "services/classLoadingService.hpp"
64 #include "services/threadService.hpp"
65 #include "utilities/macros.hpp"
66 #include "utilities/ticks.hpp"
67
68 #if INCLUDE_TRACE
69 #include "trace/tracing.hpp"
70 #endif
71
72 Dictionary* SystemDictionary::_dictionary = NULL;
73 PlaceholderTable* SystemDictionary::_placeholders = NULL;
74 Dictionary* SystemDictionary::_shared_dictionary = NULL;
75 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
76 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
77 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
78
79
80 int SystemDictionary::_number_of_modifications = 0;
81 int SystemDictionary::_sdgeneration = 0;
82 const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
83 20201,40423,99991};
84
85 oop SystemDictionary::_system_loader_lock_obj = NULL;
86
87 Klass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
88 = { NULL /*, NULL...*/ };
89
90 Klass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
91
92 oop SystemDictionary::_java_system_loader = NULL;
93
94 bool SystemDictionary::_has_loadClassInternal = false;
95 bool SystemDictionary::_has_checkPackageAccess = false;
96
97 // lazily initialized klass variables
98 Klass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
99
100
101 // ----------------------------------------------------------------------------
102 // Java-level SystemLoader
103
104 oop SystemDictionary::java_system_loader() {
105 return _java_system_loader;
106 }
107
108 void SystemDictionary::compute_java_system_loader(TRAPS) {
109 KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass));
110 JavaValue result(T_OBJECT);
111 JavaCalls::call_static(&result,
112 KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)),
113 vmSymbols::getSystemClassLoader_name(),
114 vmSymbols::void_classloader_signature(),
115 CHECK);
116
117 _java_system_loader = (oop)result.get_jobject();
118
119 CDS_ONLY(SystemDictionaryShared::initialize(CHECK);)
120 }
121
122
123 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
124 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
125 return ClassLoaderDataGraph::find_or_create(class_loader, CHECK_NULL);
126 }
127
128 // ----------------------------------------------------------------------------
129 // debugging
130
131 #ifdef ASSERT
132
133 // return true if class_name contains no '.' (internal format is '/')
134 bool SystemDictionary::is_internal_format(Symbol* class_name) {
135 if (class_name != NULL) {
136 ResourceMark rm;
137 char* name = class_name->as_C_string();
138 return strchr(name, '.') == NULL;
139 } else {
140 return true;
141 }
142 }
143
144 #endif
145
146 // ----------------------------------------------------------------------------
147 // Parallel class loading check
148
149 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
150 if (UnsyncloadClass || class_loader.is_null()) return true;
151 if (AlwaysLockClassLoader) return false;
152 return java_lang_ClassLoader::parallelCapable(class_loader());
153 }
154 // ----------------------------------------------------------------------------
155 // ParallelDefineClass flag does not apply to bootclass loader
156 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
157 if (class_loader.is_null()) return false;
158 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
159 return true;
160 }
161 return false;
162 }
163
164 /**
165 * Returns true if the passed class loader is the extension class loader.
166 */
167 bool SystemDictionary::is_ext_class_loader(Handle class_loader) {
168 if (class_loader.is_null()) {
169 return false;
170 }
171 return (class_loader->klass()->name() == vmSymbols::sun_misc_Launcher_ExtClassLoader());
172 }
173
174 // ----------------------------------------------------------------------------
175 // Resolving of classes
176
177 // Forwards to resolve_or_null
178
179 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
180 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
181 if (HAS_PENDING_EXCEPTION || klass == NULL) {
182 KlassHandle k_h(THREAD, klass);
183 // can return a null klass
184 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
185 }
186 return klass;
187 }
188
189 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) {
190 if (HAS_PENDING_EXCEPTION) {
191 // If we have a pending exception we forward it to the caller, unless throw_error is true,
192 // in which case we have to check whether the pending exception is a ClassNotFoundException,
193 // and if so convert it to a NoClassDefFoundError
194 // And chain the original ClassNotFoundException
195 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
196 ResourceMark rm(THREAD);
197 assert(klass_h() == NULL, "Should not have result with exception pending");
198 Handle e(THREAD, PENDING_EXCEPTION);
199 CLEAR_PENDING_EXCEPTION;
200 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
201 } else {
202 return NULL;
203 }
204 }
205 // Class not found, throw appropriate error or exception depending on value of throw_error
206 if (klass_h() == NULL) {
207 ResourceMark rm(THREAD);
208 if (throw_error) {
209 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
210 } else {
211 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
212 }
213 }
214 return (Klass*)klass_h();
215 }
216
217
218 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
219 bool throw_error, TRAPS)
220 {
221 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
222 }
223
224
225 // Forwards to resolve_instance_class_or_null
226
227 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
228 assert(!THREAD->is_Compiler_thread(),
229 err_msg("can not load classes with compiler thread: class=%s, classloader=%s",
230 class_name->as_C_string(),
231 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string()));
232 if (FieldType::is_array(class_name)) {
233 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
234 } else if (FieldType::is_obj(class_name)) {
235 ResourceMark rm(THREAD);
236 // Ignore wrapping L and ;.
237 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
238 class_name->utf8_length() - 2, CHECK_NULL);
239 return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL);
240 } else {
241 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
242 }
243 }
244
245 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
246 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
247 }
248
249 // Forwards to resolve_instance_class_or_null
250
251 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
252 Handle class_loader,
253 Handle protection_domain,
254 TRAPS) {
255 assert(FieldType::is_array(class_name), "must be array");
256 Klass* k = NULL;
257 FieldArrayInfo fd;
258 // dimension and object_key in FieldArrayInfo are assigned as a side-effect
259 // of this call
260 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
261 if (t == T_OBJECT) {
262 // naked oop "k" is OK here -- we assign back into it
263 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
264 class_loader,
265 protection_domain,
266 CHECK_NULL);
267 if (k != NULL) {
268 k = k->array_klass(fd.dimension(), CHECK_NULL);
269 }
270 } else {
271 k = Universe::typeArrayKlassObj(t);
272 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
273 }
274 return k;
275 }
276
277
278 // Must be called for any super-class or super-interface resolution
279 // during class definition to allow class circularity checking
280 // super-interface callers:
281 // parse_interfaces - for defineClass & jvmtiRedefineClasses
282 // super-class callers:
283 // ClassFileParser - for defineClass & jvmtiRedefineClasses
284 // load_shared_class - while loading a class from shared archive
285 // resolve_instance_class_or_null:
286 // via: handle_parallel_super_load
287 // when resolving a class that has an existing placeholder with
288 // a saved superclass [i.e. a defineClass is currently in progress]
289 // if another thread is trying to resolve the class, it must do
290 // super-class checks on its own thread to catch class circularity
291 // This last call is critical in class circularity checking for cases
292 // where classloading is delegated to different threads and the
293 // classloader lock is released.
294 // Take the case: Base->Super->Base
295 // 1. If thread T1 tries to do a defineClass of class Base
296 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
297 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
298 // so it tries to load Super
299 // 3. If we load the class internally, or user classloader uses same thread
300 // loadClassFromxxx or defineClass via parseClassFile Super ...
301 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
302 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
303 // 3.4 calls resolve_super_or_fail Base
304 // 3.5 finds T1,Base -> throws class circularity
305 //OR 4. If T2 tries to resolve Super via defineClass Super ...
306 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
307 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
308 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
309 // 4.4 finds T2, Super -> throws class circularity
310 // Must be called, even if superclass is null, since this is
311 // where the placeholder entry is created which claims this
312 // thread is loading this class/classloader.
313 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
314 Symbol* class_name,
315 Handle class_loader,
316 Handle protection_domain,
317 bool is_superclass,
318 TRAPS) {
319 // Double-check, if child class is already loaded, just return super-class,interface
320 // Don't add a placedholder if already loaded, i.e. already in system dictionary
321 // Make sure there's a placeholder for the *child* before resolving.
322 // Used as a claim that this thread is currently loading superclass/classloader
323 // Used here for ClassCircularity checks and also for heap verification
324 // (every InstanceKlass in the heap needs to be in the system dictionary
325 // or have a placeholder).
326 // Must check ClassCircularity before checking if super class is already loaded
327 //
328 // We might not already have a placeholder if this child_name was
329 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
330 // the name of the class might not be known until the stream is actually
331 // parsed.
332 // Bugs 4643874, 4715493
333 // compute_hash can have a safepoint
334
335 ClassLoaderData* loader_data = class_loader_data(class_loader);
336 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
337 int d_index = dictionary()->hash_to_index(d_hash);
338 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
339 int p_index = placeholders()->hash_to_index(p_hash);
340 // can't throw error holding a lock
341 bool child_already_loaded = false;
342 bool throw_circularity_error = false;
343 {
344 MutexLocker mu(SystemDictionary_lock, THREAD);
345 Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
346 Klass* quicksuperk;
347 // to support // loading: if child done loading, just return superclass
348 // if class_name, & class_loader don't match:
349 // if initial define, SD update will give LinkageError
350 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
351 // so we don't throw an exception here.
352 // see: nsk redefclass014 & java.lang.instrument Instrument032
353 if ((childk != NULL ) && (is_superclass) &&
354 ((quicksuperk = InstanceKlass::cast(childk)->super()) != NULL) &&
355
356 ((quicksuperk->name() == class_name) &&
357 (quicksuperk->class_loader() == class_loader()))) {
358 return quicksuperk;
359 } else {
360 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
361 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
362 throw_circularity_error = true;
363 }
364 }
365 if (!throw_circularity_error) {
366 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
367 }
368 }
369 if (throw_circularity_error) {
370 ResourceMark rm(THREAD);
371 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
372 }
373
374 // java.lang.Object should have been found above
375 assert(class_name != NULL, "null super class for resolving");
376 // Resolve the super class or interface, check results on return
377 Klass* superk = SystemDictionary::resolve_or_null(class_name,
378 class_loader,
379 protection_domain,
380 THREAD);
381
382 KlassHandle superk_h(THREAD, superk);
383
384 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
385 // It is no longer necessary to keep the placeholder table alive until update_dictionary
386 // or error. GC used to walk the placeholder table as strong roots.
387 // The instanceKlass is kept alive because the class loader is on the stack,
388 // which keeps the loader_data alive, as well as all instanceKlasses in
389 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
390 {
391 MutexLocker mu(SystemDictionary_lock, THREAD);
392 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
393 SystemDictionary_lock->notify_all();
394 }
395 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
396 // can null superk
397 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD));
398 }
399
400 return superk_h();
401 }
402
403 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
404 Handle class_loader,
405 Handle protection_domain,
406 TRAPS) {
407 if(!has_checkPackageAccess()) return;
408
409 // Now we have to call back to java to check if the initating class has access
410 JavaValue result(T_VOID);
411 if (TraceProtectionDomainVerification) {
412 // Print out trace information
413 tty->print_cr("Checking package access");
414 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr();
415 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr();
416 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr();
417 }
418
419 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass());
420 JavaCalls::call_special(&result,
421 class_loader,
422 system_loader,
423 vmSymbols::checkPackageAccess_name(),
424 vmSymbols::class_protectiondomain_signature(),
425 Handle(THREAD, klass->java_mirror()),
426 protection_domain,
427 THREAD);
428
429 if (TraceProtectionDomainVerification) {
430 if (HAS_PENDING_EXCEPTION) {
431 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!");
432 } else {
433 tty->print_cr(" -> granted");
434 }
435 tty->cr();
436 }
437
438 if (HAS_PENDING_EXCEPTION) return;
439
440 // If no exception has been thrown, we have validated the protection domain
441 // Insert the protection domain of the initiating class into the set.
442 {
443 // We recalculate the entry here -- we've called out to java since
444 // the last time it was calculated.
445 ClassLoaderData* loader_data = class_loader_data(class_loader);
446
447 Symbol* kn = klass->name();
448 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
449 int d_index = dictionary()->hash_to_index(d_hash);
450
451 MutexLocker mu(SystemDictionary_lock, THREAD);
452 {
453 // Note that we have an entry, and entries can be deleted only during GC,
454 // so we cannot allow GC to occur while we're holding this entry.
455
456 // We're using a No_Safepoint_Verifier to catch any place where we
457 // might potentially do a GC at all.
458 // Dictionary::do_unloading() asserts that classes in SD are only
459 // unloaded at a safepoint. Anonymous classes are not in SD.
460 No_Safepoint_Verifier nosafepoint;
461 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
462 protection_domain, THREAD);
463 }
464 }
465 }
466
467 // We only get here if this thread finds that another thread
468 // has already claimed the placeholder token for the current operation,
469 // but that other thread either never owned or gave up the
470 // object lock
471 // Waits on SystemDictionary_lock to indicate placeholder table updated
472 // On return, caller must recheck placeholder table state
473 //
474 // We only get here if
475 // 1) custom classLoader, i.e. not bootstrap classloader
476 // 2) UnsyncloadClass not set
477 // 3) custom classLoader has broken the class loader objectLock
478 // so another thread got here in parallel
479 //
480 // lockObject must be held.
481 // Complicated dance due to lock ordering:
482 // Must first release the classloader object lock to
483 // allow initial definer to complete the class definition
484 // and to avoid deadlock
485 // Reclaim classloader lock object with same original recursion count
486 // Must release SystemDictionary_lock after notify, since
487 // class loader lock must be claimed before SystemDictionary_lock
488 // to prevent deadlocks
489 //
490 // The notify allows applications that did an untimed wait() on
491 // the classloader object lock to not hang.
492 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
493 assert_lock_strong(SystemDictionary_lock);
494
495 bool calledholdinglock
496 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
497 assert(calledholdinglock,"must hold lock for notify");
498 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
499 ObjectSynchronizer::notifyall(lockObject, THREAD);
500 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
501 SystemDictionary_lock->wait();
502 SystemDictionary_lock->unlock();
503 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
504 SystemDictionary_lock->lock();
505 }
506
507 // If the class in is in the placeholder table, class loading is in progress
508 // For cases where the application changes threads to load classes, it
509 // is critical to ClassCircularity detection that we try loading
510 // the superclass on the same thread internally, so we do parallel
511 // super class loading here.
512 // This also is critical in cases where the original thread gets stalled
513 // even in non-circularity situations.
514 // Note: must call resolve_super_or_fail even if null super -
515 // to force placeholder entry creation for this class for circularity detection
516 // Caller must check for pending exception
517 // Returns non-null Klass* if other thread has completed load
518 // and we are done,
519 // If return null Klass* and no pending exception, the caller must load the class
520 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
521 Symbol* name, Symbol* superclassname, Handle class_loader,
522 Handle protection_domain, Handle lockObject, TRAPS) {
523
524 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
525 ClassLoaderData* loader_data = class_loader_data(class_loader);
526 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
527 int d_index = dictionary()->hash_to_index(d_hash);
528 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
529 int p_index = placeholders()->hash_to_index(p_hash);
530
531 // superk is not used, resolve_super called for circularity check only
532 // This code is reached in two situations. One if this thread
533 // is loading the same class twice (e.g. ClassCircularity, or
534 // java.lang.instrument).
535 // The second is if another thread started the resolve_super first
536 // and has not yet finished.
537 // In both cases the original caller will clean up the placeholder
538 // entry on error.
539 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
540 superclassname,
541 class_loader,
542 protection_domain,
543 true,
544 CHECK_(nh));
545
546 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
547 // Serial class loaders and bootstrap classloader do wait for superclass loads
548 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
549 MutexLocker mu(SystemDictionary_lock, THREAD);
550 // Check if classloading completed while we were loading superclass or waiting
551 Klass* check = find_class(d_index, d_hash, name, loader_data);
552 if (check != NULL) {
553 // Klass is already loaded, so just return it
554 return(instanceKlassHandle(THREAD, check));
555 } else {
556 return nh;
557 }
558 }
559
560 // must loop to both handle other placeholder updates
561 // and spurious notifications
562 bool super_load_in_progress = true;
563 PlaceholderEntry* placeholder;
564 while (super_load_in_progress) {
565 MutexLocker mu(SystemDictionary_lock, THREAD);
566 // Check if classloading completed while we were loading superclass or waiting
567 Klass* check = find_class(d_index, d_hash, name, loader_data);
568 if (check != NULL) {
569 // Klass is already loaded, so just return it
570 return(instanceKlassHandle(THREAD, check));
571 } else {
572 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
573 if (placeholder && placeholder->super_load_in_progress() ){
574 // Before UnsyncloadClass:
575 // We only get here if the application has released the
576 // classloader lock when another thread was in the middle of loading a
577 // superclass/superinterface for this class, and now
578 // this thread is also trying to load this class.
579 // To minimize surprises, the first thread that started to
580 // load a class should be the one to complete the loading
581 // with the classfile it initially expected.
582 // This logic has the current thread wait once it has done
583 // all the superclass/superinterface loading it can, until
584 // the original thread completes the class loading or fails
585 // If it completes we will use the resulting InstanceKlass
586 // which we will find below in the systemDictionary.
587 // We also get here for parallel bootstrap classloader
588 if (class_loader.is_null()) {
589 SystemDictionary_lock->wait();
590 } else {
591 double_lock_wait(lockObject, THREAD);
592 }
593 } else {
594 // If not in SD and not in PH, other thread's load must have failed
595 super_load_in_progress = false;
596 }
597 }
598 }
599 return (nh);
600 }
601
602
603 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
604 Handle class_loader,
605 Handle protection_domain,
606 TRAPS) {
607 assert(name != NULL && !FieldType::is_array(name) &&
608 !FieldType::is_obj(name), "invalid class name");
609
610 Ticks class_load_start_time = Ticks::now();
611
612 // UseNewReflection
613 // Fix for 4474172; see evaluation for more details
614 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
615 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
616
617 // Do lookup to see if class already exist and the protection domain
618 // has the right access
619 // This call uses find which checks protection domain already matches
620 // All subsequent calls use find_class, and set has_loaded_class so that
621 // before we return a result we call out to java to check for valid protection domain
622 // to allow returning the Klass* and add it to the pd_set if it is valid
623 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
624 int d_index = dictionary()->hash_to_index(d_hash);
625 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
626 protection_domain, THREAD);
627 if (probe != NULL) return probe;
628
629
630 // Non-bootstrap class loaders will call out to class loader and
631 // define via jvm/jni_DefineClass which will acquire the
632 // class loader object lock to protect against multiple threads
633 // defining the class in parallel by accident.
634 // This lock must be acquired here so the waiter will find
635 // any successful result in the SystemDictionary and not attempt
636 // the define
637 // ParallelCapable Classloaders and the bootstrap classloader,
638 // or all classloaders with UnsyncloadClass do not acquire lock here
639 bool DoObjectLock = true;
640 if (is_parallelCapable(class_loader)) {
641 DoObjectLock = false;
642 }
643
644 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
645 int p_index = placeholders()->hash_to_index(p_hash);
646
647 // Class is not in SystemDictionary so we have to do loading.
648 // Make sure we are synchronized on the class loader before we proceed
649 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
650 check_loader_lock_contention(lockObject, THREAD);
651 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
652
653 // Check again (after locking) if class already exist in SystemDictionary
654 bool class_has_been_loaded = false;
655 bool super_load_in_progress = false;
656 bool havesupername = false;
657 instanceKlassHandle k;
658 PlaceholderEntry* placeholder;
659 Symbol* superclassname = NULL;
660
661 {
662 MutexLocker mu(SystemDictionary_lock, THREAD);
663 Klass* check = find_class(d_index, d_hash, name, loader_data);
664 if (check != NULL) {
665 // Klass is already loaded, so just return it
666 class_has_been_loaded = true;
667 k = instanceKlassHandle(THREAD, check);
668 } else {
669 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
670 if (placeholder && placeholder->super_load_in_progress()) {
671 super_load_in_progress = true;
672 if (placeholder->havesupername() == true) {
673 superclassname = placeholder->supername();
674 havesupername = true;
675 }
676 }
677 }
678 }
679
680 // If the class is in the placeholder table, class loading is in progress
681 if (super_load_in_progress && havesupername==true) {
682 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
683 class_loader, protection_domain, lockObject, THREAD);
684 if (HAS_PENDING_EXCEPTION) {
685 return NULL;
686 }
687 if (!k.is_null()) {
688 class_has_been_loaded = true;
689 }
690 }
691
692 bool throw_circularity_error = false;
693 if (!class_has_been_loaded) {
694 bool load_instance_added = false;
695
696 // add placeholder entry to record loading instance class
697 // Five cases:
698 // All cases need to prevent modifying bootclasssearchpath
699 // in parallel with a classload of same classname
700 // Redefineclasses uses existence of the placeholder for the duration
701 // of the class load to prevent concurrent redefinition of not completely
702 // defined classes.
703 // case 1. traditional classloaders that rely on the classloader object lock
704 // - no other need for LOAD_INSTANCE
705 // case 2. traditional classloaders that break the classloader object lock
706 // as a deadlock workaround. Detection of this case requires that
707 // this check is done while holding the classloader object lock,
708 // and that lock is still held when calling classloader's loadClass.
709 // For these classloaders, we ensure that the first requestor
710 // completes the load and other requestors wait for completion.
711 // case 3. UnsyncloadClass - don't use objectLocker
712 // With this flag, we allow parallel classloading of a
713 // class/classloader pair
714 // case4. Bootstrap classloader - don't own objectLocker
715 // This classloader supports parallelism at the classloader level,
716 // but only allows a single load of a class/classloader pair.
717 // No performance benefit and no deadlock issues.
718 // case 5. parallelCapable user level classloaders - without objectLocker
719 // Allow parallel classloading of a class/classloader pair
720
721 {
722 MutexLocker mu(SystemDictionary_lock, THREAD);
723 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
724 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
725 if (oldprobe) {
726 // only need check_seen_thread once, not on each loop
727 // 6341374 java/lang/Instrument with -Xcomp
728 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
729 throw_circularity_error = true;
730 } else {
731 // case 1: traditional: should never see load_in_progress.
732 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
733
734 // case 4: bootstrap classloader: prevent futile classloading,
735 // wait on first requestor
736 if (class_loader.is_null()) {
737 SystemDictionary_lock->wait();
738 } else {
739 // case 2: traditional with broken classloader lock. wait on first
740 // requestor.
741 double_lock_wait(lockObject, THREAD);
742 }
743 // Check if classloading completed while we were waiting
744 Klass* check = find_class(d_index, d_hash, name, loader_data);
745 if (check != NULL) {
746 // Klass is already loaded, so just return it
747 k = instanceKlassHandle(THREAD, check);
748 class_has_been_loaded = true;
749 }
750 // check if other thread failed to load and cleaned up
751 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
752 }
753 }
754 }
755 }
756 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
757 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
758 // LOAD_INSTANCE in parallel
759
760 if (!throw_circularity_error && !class_has_been_loaded) {
761 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
762 load_instance_added = true;
763 // For class loaders that do not acquire the classloader object lock,
764 // if they did not catch another thread holding LOAD_INSTANCE,
765 // need a check analogous to the acquire ObjectLocker/find_class
766 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
767 // one final check if the load has already completed
768 // class loaders holding the ObjectLock shouldn't find the class here
769 Klass* check = find_class(d_index, d_hash, name, loader_data);
770 if (check != NULL) {
771 // Klass is already loaded, so return it after checking/adding protection domain
772 k = instanceKlassHandle(THREAD, check);
773 class_has_been_loaded = true;
774 }
775 }
776 }
777
778 // must throw error outside of owning lock
779 if (throw_circularity_error) {
780 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
781 ResourceMark rm(THREAD);
782 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
783 }
784
785 if (!class_has_been_loaded) {
786
787 // Do actual loading
788 k = load_instance_class(name, class_loader, THREAD);
789
790 // For UnsyncloadClass only
791 // If they got a linkageError, check if a parallel class load succeeded.
792 // If it did, then for bytecode resolution the specification requires
793 // that we return the same result we did for the other thread, i.e. the
794 // successfully loaded InstanceKlass
795 // Should not get here for classloaders that support parallelism
796 // with the new cleaner mechanism, even with AllowParallelDefineClass
797 // Bootstrap goes through here to allow for an extra guarantee check
798 if (UnsyncloadClass || (class_loader.is_null())) {
799 if (k.is_null() && HAS_PENDING_EXCEPTION
800 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
801 MutexLocker mu(SystemDictionary_lock, THREAD);
802 Klass* check = find_class(d_index, d_hash, name, loader_data);
803 if (check != NULL) {
804 // Klass is already loaded, so just use it
805 k = instanceKlassHandle(THREAD, check);
806 CLEAR_PENDING_EXCEPTION;
807 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
808 }
809 }
810 }
811
812 // If everything was OK (no exceptions, no null return value), and
813 // class_loader is NOT the defining loader, do a little more bookkeeping.
814 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
815 k->class_loader() != class_loader()) {
816
817 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
818
819 // Need to check for a PENDING_EXCEPTION again; check_constraints
820 // can throw and doesn't use the CHECK macro.
821 if (!HAS_PENDING_EXCEPTION) {
822 { // Grabbing the Compile_lock prevents systemDictionary updates
823 // during compilations.
824 MutexLocker mu(Compile_lock, THREAD);
825 update_dictionary(d_index, d_hash, p_index, p_hash,
826 k, class_loader, THREAD);
827 }
828
829 if (JvmtiExport::should_post_class_load()) {
830 Thread *thread = THREAD;
831 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
832 JvmtiExport::post_class_load((JavaThread *) thread, k());
833 }
834 }
835 }
836 } // load_instance_class loop
837
838 if (load_instance_added == true) {
839 // clean up placeholder entries for LOAD_INSTANCE success or error
840 // This brackets the SystemDictionary updates for both defining
841 // and initiating loaders
842 MutexLocker mu(SystemDictionary_lock, THREAD);
843 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
844 SystemDictionary_lock->notify_all();
845 }
846 }
847
848 if (HAS_PENDING_EXCEPTION || k.is_null()) {
849 return NULL;
850 }
851
852 post_class_load_event(class_load_start_time, k, class_loader);
853
854 #ifdef ASSERT
855 {
856 ClassLoaderData* loader_data = k->class_loader_data();
857 MutexLocker mu(SystemDictionary_lock, THREAD);
858 Klass* kk = find_class(name, loader_data);
859 assert(kk == k(), "should be present in dictionary");
860 }
861 #endif
862
863 // return if the protection domain in NULL
864 if (protection_domain() == NULL) return k();
865
866 // Check the protection domain has the right access
867 {
868 MutexLocker mu(SystemDictionary_lock, THREAD);
869 // Note that we have an entry, and entries can be deleted only during GC,
870 // so we cannot allow GC to occur while we're holding this entry.
871 // We're using a No_Safepoint_Verifier to catch any place where we
872 // might potentially do a GC at all.
873 // Dictionary::do_unloading() asserts that classes in SD are only
874 // unloaded at a safepoint. Anonymous classes are not in SD.
875 No_Safepoint_Verifier nosafepoint;
876 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
877 loader_data,
878 protection_domain)) {
879 return k();
880 }
881 }
882
883 // Verify protection domain. If it fails an exception is thrown
884 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
885
886 return k();
887 }
888
889
890 // This routine does not lock the system dictionary.
891 //
892 // Since readers don't hold a lock, we must make sure that system
893 // dictionary entries are only removed at a safepoint (when only one
894 // thread is running), and are added to in a safe way (all links must
895 // be updated in an MT-safe manner).
896 //
897 // Callers should be aware that an entry could be added just after
898 // _dictionary->bucket(index) is read here, so the caller will not see
899 // the new entry.
900
901 Klass* SystemDictionary::find(Symbol* class_name,
902 Handle class_loader,
903 Handle protection_domain,
904 TRAPS) {
905
906 // UseNewReflection
907 // The result of this call should be consistent with the result
908 // of the call to resolve_instance_class_or_null().
909 // See evaluation 6790209 and 4474172 for more details.
910 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
911 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
912
913 if (loader_data == NULL) {
914 // If the ClassLoaderData has not been setup,
915 // then the class loader has no entries in the dictionary.
916 return NULL;
917 }
918
919 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
920 int d_index = dictionary()->hash_to_index(d_hash);
921
922 {
923 // Note that we have an entry, and entries can be deleted only during GC,
924 // so we cannot allow GC to occur while we're holding this entry.
925 // We're using a No_Safepoint_Verifier to catch any place where we
926 // might potentially do a GC at all.
927 // Dictionary::do_unloading() asserts that classes in SD are only
928 // unloaded at a safepoint. Anonymous classes are not in SD.
929 No_Safepoint_Verifier nosafepoint;
930 return dictionary()->find(d_index, d_hash, class_name, loader_data,
931 protection_domain, THREAD);
932 }
933 }
934
935
936 // Look for a loaded instance or array klass by name. Do not do any loading.
937 // return NULL in case of error.
938 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
939 Handle class_loader,
940 Handle protection_domain,
941 TRAPS) {
942 Klass* k = NULL;
943 assert(class_name != NULL, "class name must be non NULL");
944
945 if (FieldType::is_array(class_name)) {
946 // The name refers to an array. Parse the name.
947 // dimension and object_key in FieldArrayInfo are assigned as a
948 // side-effect of this call
949 FieldArrayInfo fd;
950 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
951 if (t != T_OBJECT) {
952 k = Universe::typeArrayKlassObj(t);
953 } else {
954 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
955 }
956 if (k != NULL) {
957 k = k->array_klass_or_null(fd.dimension());
958 }
959 } else {
960 k = find(class_name, class_loader, protection_domain, THREAD);
961 }
962 return k;
963 }
964
965 // Note: this method is much like resolve_from_stream, but
966 // updates no supplemental data structures.
967 // TODO consolidate the two methods with a helper routine?
968 Klass* SystemDictionary::parse_stream(Symbol* class_name,
969 Handle class_loader,
970 Handle protection_domain,
971 ClassFileStream* st,
972 KlassHandle host_klass,
973 GrowableArray<Handle>* cp_patches,
974 TRAPS) {
975 TempNewSymbol parsed_name = NULL;
976
977 Ticks class_load_start_time = Ticks::now();
978
979 ClassLoaderData* loader_data;
980 if (host_klass.not_null()) {
981 // Create a new CLD for anonymous class, that uses the same class loader
982 // as the host_klass
983 assert(EnableInvokeDynamic, "");
984 guarantee(host_klass->class_loader() == class_loader(), "should be the same");
985 guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping");
986 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
987 loader_data->record_dependency(host_klass(), CHECK_NULL);
988 } else {
989 loader_data = ClassLoaderData::class_loader_data(class_loader());
990 }
991
992 // Parse the stream. Note that we do this even though this klass might
993 // already be present in the SystemDictionary, otherwise we would not
994 // throw potential ClassFormatErrors.
995 //
996 // Note: "name" is updated.
997
998 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
999 loader_data,
1000 protection_domain,
1001 host_klass,
1002 cp_patches,
1003 parsed_name,
1004 true,
1005 THREAD);
1006
1007
1008 if (host_klass.not_null() && k.not_null()) {
1009 assert(EnableInvokeDynamic, "");
1010 // If it's anonymous, initialize it now, since nobody else will.
1011
1012 {
1013 MutexLocker mu_r(Compile_lock, THREAD);
1014
1015 // Add to class hierarchy, initialize vtables, and do possible
1016 // deoptimizations.
1017 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1018
1019 // But, do not add to system dictionary.
1020
1021 // compiled code dependencies need to be validated anyway
1022 notice_modification();
1023 }
1024
1025 // Rewrite and patch constant pool here.
1026 k->link_class(CHECK_NULL);
1027 if (cp_patches != NULL) {
1028 k->constants()->patch_resolved_references(cp_patches);
1029 }
1030 k->eager_initialize(CHECK_NULL);
1031
1032 // notify jvmti
1033 if (JvmtiExport::should_post_class_load()) {
1034 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1035 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1036 }
1037
1038 post_class_load_event(class_load_start_time, k, class_loader);
1039 }
1040 assert(host_klass.not_null() || cp_patches == NULL,
1041 "cp_patches only found with host_klass");
1042
1043 return k();
1044 }
1045
1046 // Add a klass to the system from a stream (called by jni_DefineClass and
1047 // JVM_DefineClass).
1048 // Note: class_name can be NULL. In that case we do not know the name of
1049 // the class until we have parsed the stream.
1050
1051 Klass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1052 Handle class_loader,
1053 Handle protection_domain,
1054 ClassFileStream* st,
1055 bool verify,
1056 TRAPS) {
1057
1058 // Classloaders that support parallelism, e.g. bootstrap classloader,
1059 // or all classloaders with UnsyncloadClass do not acquire lock here
1060 bool DoObjectLock = true;
1061 if (is_parallelCapable(class_loader)) {
1062 DoObjectLock = false;
1063 }
1064
1065 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
1066
1067 // Make sure we are synchronized on the class loader before we proceed
1068 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1069 check_loader_lock_contention(lockObject, THREAD);
1070 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1071
1072 TempNewSymbol parsed_name = NULL;
1073
1074 // Parse the stream. Note that we do this even though this klass might
1075 // already be present in the SystemDictionary, otherwise we would not
1076 // throw potential ClassFormatErrors.
1077 //
1078 // Note: "name" is updated.
1079
1080 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
1081 loader_data,
1082 protection_domain,
1083 parsed_name,
1084 verify,
1085 THREAD);
1086
1087 const char* pkg = "java/";
1088 if (!HAS_PENDING_EXCEPTION &&
1089 !class_loader.is_null() &&
1090 parsed_name != NULL &&
1091 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
1092 // It is illegal to define classes in the "java." package from
1093 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
1094 ResourceMark rm(THREAD);
1095 char* name = parsed_name->as_C_string();
1096 char* index = strrchr(name, '/');
1097 *index = '\0'; // chop to just the package name
1098 while ((index = strchr(name, '/')) != NULL) {
1099 *index = '.'; // replace '/' with '.' in package name
1100 }
1101 const char* fmt = "Prohibited package name: %s";
1102 size_t len = strlen(fmt) + strlen(name);
1103 char* message = NEW_RESOURCE_ARRAY(char, len);
1104 jio_snprintf(message, len, fmt, name);
1105 Exceptions::_throw_msg(THREAD_AND_LOCATION,
1106 vmSymbols::java_lang_SecurityException(), message);
1107 }
1108
1109 if (!HAS_PENDING_EXCEPTION) {
1110 assert(parsed_name != NULL, "Sanity");
1111 assert(class_name == NULL || class_name == parsed_name, "name mismatch");
1112 // Verification prevents us from creating names with dots in them, this
1113 // asserts that that's the case.
1114 assert(is_internal_format(parsed_name),
1115 "external class name format used internally");
1116
1117 // Add class just loaded
1118 // If a class loader supports parallel classloading handle parallel define requests
1119 // find_or_define_instance_class may return a different InstanceKlass
1120 if (is_parallelCapable(class_loader)) {
1121 k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
1122 } else {
1123 define_instance_class(k, THREAD);
1124 }
1125 }
1126
1127 // Make sure we have an entry in the SystemDictionary on success
1128 debug_only( {
1129 if (!HAS_PENDING_EXCEPTION) {
1130 assert(parsed_name != NULL, "parsed_name is still null?");
1131 Symbol* h_name = k->name();
1132 ClassLoaderData *defining_loader_data = k->class_loader_data();
1133
1134 MutexLocker mu(SystemDictionary_lock, THREAD);
1135
1136 Klass* check = find_class(parsed_name, loader_data);
1137 assert(check == k(), "should be present in the dictionary");
1138
1139 Klass* check2 = find_class(h_name, defining_loader_data);
1140 assert(check == check2, "name inconsistancy in SystemDictionary");
1141 }
1142 } );
1143
1144 return k();
1145 }
1146
1147 #if INCLUDE_CDS
1148 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
1149 int number_of_entries) {
1150 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
1151 "bad shared dictionary size.");
1152 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1153 }
1154
1155
1156 // If there is a shared dictionary, then find the entry for the
1157 // given shared system class, if any.
1158
1159 Klass* SystemDictionary::find_shared_class(Symbol* class_name) {
1160 if (shared_dictionary() != NULL) {
1161 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
1162 int d_index = shared_dictionary()->hash_to_index(d_hash);
1163
1164 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1165 } else {
1166 return NULL;
1167 }
1168 }
1169
1170
1171 // Load a class from the shared spaces (found through the shared system
1172 // dictionary). Force the superclass and all interfaces to be loaded.
1173 // Update the class definition to include sibling classes and no
1174 // subclasses (yet). [Classes in the shared space are not part of the
1175 // object hierarchy until loaded.]
1176
1177 instanceKlassHandle SystemDictionary::load_shared_class(
1178 Symbol* class_name, Handle class_loader, TRAPS) {
1179 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
1180 // Make sure we only return the boot class for the NULL classloader.
1181 if (ik.not_null() &&
1182 SharedClassUtil::is_shared_boot_class(ik()) && class_loader.is_null()) {
1183 Handle protection_domain;
1184 return load_shared_class(ik, class_loader, protection_domain, THREAD);
1185 }
1186 return instanceKlassHandle();
1187 }
1188
1189 instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
1190 Handle class_loader,
1191 Handle protection_domain, TRAPS) {
1192 if (ik.not_null()) {
1193 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1194 Symbol* class_name = ik->name();
1195
1196 // Found the class, now load the superclass and interfaces. If they
1197 // are shared, add them to the main system dictionary and reset
1198 // their hierarchy references (supers, subs, and interfaces).
1199
1200 if (ik->super() != NULL) {
1201 Symbol* cn = ik->super()->name();
1202 resolve_super_or_fail(class_name, cn,
1203 class_loader, protection_domain, true, CHECK_(nh));
1204 }
1205
1206 Array<Klass*>* interfaces = ik->local_interfaces();
1207 int num_interfaces = interfaces->length();
1208 for (int index = 0; index < num_interfaces; index++) {
1209 Klass* k = interfaces->at(index);
1210
1211 // Note: can not use InstanceKlass::cast here because
1212 // interfaces' InstanceKlass's C++ vtbls haven't been
1213 // reinitialized yet (they will be once the interface classes
1214 // are loaded)
1215 Symbol* name = k->name();
1216 resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
1217 }
1218
1219 // Adjust methods to recover missing data. They need addresses for
1220 // interpreter entry points and their default native method address
1221 // must be reset.
1222
1223 // Updating methods must be done under a lock so multiple
1224 // threads don't update these in parallel
1225 //
1226 // Shared classes are all currently loaded by either the bootstrap or
1227 // internal parallel class loaders, so this will never cause a deadlock
1228 // on a custom class loader lock.
1229
1230 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1231 {
1232 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1233 check_loader_lock_contention(lockObject, THREAD);
1234 ObjectLocker ol(lockObject, THREAD, true);
1235 ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh));
1236 }
1237
1238 if (TraceClassLoading) {
1239 ResourceMark rm;
1240 tty->print("[Loaded %s", ik->external_name());
1241 tty->print(" from shared objects file");
1242 if (class_loader.not_null()) {
1243 tty->print(" by %s", loader_data->loader_name());
1244 }
1245 tty->print_cr("]");
1246 }
1247
1248 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1249 // Only dump the classes that can be stored into CDS archive
1250 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1251 ResourceMark rm(THREAD);
1252 classlist_file->print_cr("%s", ik->name()->as_C_string());
1253 classlist_file->flush();
1254 }
1255 }
1256
1257 // notify a class loaded from shared object
1258 ClassLoadingService::notify_class_loaded(InstanceKlass::cast(ik()),
1259 true /* shared class */);
1260 }
1261 return ik;
1262 }
1263 #endif // INCLUDE_CDS
1264
1265 instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1266 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1267 if (class_loader.is_null()) {
1268
1269 // Search the shared system dictionary for classes preloaded into the
1270 // shared spaces.
1271 instanceKlassHandle k;
1272 {
1273 #if INCLUDE_CDS
1274 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1275 k = load_shared_class(class_name, class_loader, THREAD);
1276 #endif
1277 }
1278
1279 if (k.is_null()) {
1280 // Use VM class loader
1281 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1282 k = ClassLoader::load_classfile(class_name, CHECK_(nh));
1283 }
1284
1285 // find_or_define_instance_class may return a different InstanceKlass
1286 if (!k.is_null()) {
1287 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
1288 }
1289 return k;
1290 } else {
1291 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1292 ResourceMark rm(THREAD);
1293
1294 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1295 JavaThread* jt = (JavaThread*) THREAD;
1296
1297 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1298 ClassLoader::perf_app_classload_selftime(),
1299 ClassLoader::perf_app_classload_count(),
1300 jt->get_thread_stat()->perf_recursion_counts_addr(),
1301 jt->get_thread_stat()->perf_timers_addr(),
1302 PerfClassTraceTime::CLASS_LOAD);
1303
1304 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
1305 // Translate to external class name format, i.e., convert '/' chars to '.'
1306 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
1307
1308 JavaValue result(T_OBJECT);
1309
1310 KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass());
1311
1312 // Call public unsynchronized loadClass(String) directly for all class loaders
1313 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
1314 // acquire a class-name based lock rather than the class loader object lock.
1315 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
1316 // so the call to loadClassInternal() was not required.
1317 //
1318 // UnsyncloadClass flag means both call loadClass(String) and do
1319 // not acquire the class loader lock even for class loaders that are
1320 // not parallelCapable. This was a risky transitional
1321 // flag for diagnostic purposes only. It is risky to call
1322 // custom class loaders without synchronization.
1323 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1324 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
1325 // Do NOT assume this will be supported in future releases.
1326 //
1327 // Added MustCallLoadClassInternal in case we discover in the field
1328 // a customer that counts on this call
1329 if (MustCallLoadClassInternal && has_loadClassInternal()) {
1330 JavaCalls::call_special(&result,
1331 class_loader,
1332 spec_klass,
1333 vmSymbols::loadClassInternal_name(),
1334 vmSymbols::string_class_signature(),
1335 string,
1336 CHECK_(nh));
1337 } else {
1338 JavaCalls::call_virtual(&result,
1339 class_loader,
1340 spec_klass,
1341 vmSymbols::loadClass_name(),
1342 vmSymbols::string_class_signature(),
1343 string,
1344 CHECK_(nh));
1345 }
1346
1347 assert(result.get_type() == T_OBJECT, "just checking");
1348 oop obj = (oop) result.get_jobject();
1349
1350 // Primitive classes return null since forName() can not be
1351 // used to obtain any of the Class objects representing primitives or void
1352 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1353 instanceKlassHandle k =
1354 instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj));
1355 // For user defined Java class loaders, check that the name returned is
1356 // the same as that requested. This check is done for the bootstrap
1357 // loader when parsing the class file.
1358 if (class_name == k->name()) {
1359 return k;
1360 }
1361 }
1362 // Class is not found or has the wrong name, return NULL
1363 return nh;
1364 }
1365 }
1366
1367 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
1368
1369 ClassLoaderData* loader_data = k->class_loader_data();
1370 Handle class_loader_h(THREAD, loader_data->class_loader());
1371
1372 for (uintx it = 0; it < GCExpandToAllocateDelayMillis; it++){}
1373
1374 // for bootstrap and other parallel classloaders don't acquire lock,
1375 // use placeholder token
1376 // If a parallelCapable class loader calls define_instance_class instead of
1377 // find_or_define_instance_class to get here, we have a timing
1378 // hole with systemDictionary updates and check_constraints
1379 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1380 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1381 compute_loader_lock_object(class_loader_h, THREAD)),
1382 "define called without lock");
1383 }
1384
1385 // Check class-loading constraints. Throw exception if violation is detected.
1386 // Grabs and releases SystemDictionary_lock
1387 // The check_constraints/find_class call and update_dictionary sequence
1388 // must be "atomic" for a specific class/classloader pair so we never
1389 // define two different instanceKlasses for that class/classloader pair.
1390 // Existing classloaders will call define_instance_class with the
1391 // classloader lock held
1392 // Parallel classloaders will call find_or_define_instance_class
1393 // which will require a token to perform the define class
1394 Symbol* name_h = k->name();
1395 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1396 int d_index = dictionary()->hash_to_index(d_hash);
1397 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1398
1399 // Register class just loaded with class loader (placed in Vector)
1400 // Note we do this before updating the dictionary, as this can
1401 // fail with an OutOfMemoryError (if it does, we will *not* put this
1402 // class in the dictionary and will not update the class hierarchy).
1403 // JVMTI FollowReferences needs to find the classes this way.
1404 if (k->class_loader() != NULL) {
1405 methodHandle m(THREAD, Universe::loader_addClass_method());
1406 JavaValue result(T_VOID);
1407 JavaCallArguments args(class_loader_h);
1408 args.push_oop(Handle(THREAD, k->java_mirror()));
1409 JavaCalls::call(&result, m, &args, CHECK);
1410 }
1411
1412 // Add the new class. We need recompile lock during update of CHA.
1413 {
1414 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1415 int p_index = placeholders()->hash_to_index(p_hash);
1416
1417 MutexLocker mu_r(Compile_lock, THREAD);
1418
1419 // Add to class hierarchy, initialize vtables, and do possible
1420 // deoptimizations.
1421 add_to_hierarchy(k, CHECK); // No exception, but can block
1422
1423 // Add to systemDictionary - so other classes can see it.
1424 // Grabs and releases SystemDictionary_lock
1425 update_dictionary(d_index, d_hash, p_index, p_hash,
1426 k, class_loader_h, THREAD);
1427 }
1428 k->eager_initialize(THREAD);
1429
1430 // notify jvmti
1431 if (JvmtiExport::should_post_class_load()) {
1432 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1433 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1434
1435 }
1436
1437 }
1438
1439 // Support parallel classloading
1440 // All parallel class loaders, including bootstrap classloader
1441 // lock a placeholder entry for this class/class_loader pair
1442 // to allow parallel defines of different classes for this class loader
1443 // With AllowParallelDefine flag==true, in case they do not synchronize around
1444 // FindLoadedClass/DefineClass, calls, we check for parallel
1445 // loading for them, wait if a defineClass is in progress
1446 // and return the initial requestor's results
1447 // This flag does not apply to the bootstrap classloader.
1448 // With AllowParallelDefine flag==false, call through to define_instance_class
1449 // which will throw LinkageError: duplicate class definition.
1450 // False is the requested default.
1451 // For better performance, the class loaders should synchronize
1452 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1453 // potentially waste time reading and parsing the bytestream.
1454 // Note: VM callers should ensure consistency of k/class_name,class_loader
1455 instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
1456
1457 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1458 Symbol* name_h = k->name(); // passed in class_name may be null
1459 ClassLoaderData* loader_data = class_loader_data(class_loader);
1460
1461 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1462 int d_index = dictionary()->hash_to_index(d_hash);
1463
1464 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1465 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1466 int p_index = placeholders()->hash_to_index(p_hash);
1467 PlaceholderEntry* probe;
1468
1469 {
1470 MutexLocker mu(SystemDictionary_lock, THREAD);
1471 // First check if class already defined
1472 if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
1473 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1474 if (check != NULL) {
1475 return(instanceKlassHandle(THREAD, check));
1476 }
1477 }
1478
1479 // Acquire define token for this class/classloader
1480 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1481 // Wait if another thread defining in parallel
1482 // All threads wait - even those that will throw duplicate class: otherwise
1483 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1484 // if other thread has not finished updating dictionary
1485 while (probe->definer() != NULL) {
1486 SystemDictionary_lock->wait();
1487 }
1488 // Only special cases allow parallel defines and can use other thread's results
1489 // Other cases fall through, and may run into duplicate defines
1490 // caught by finding an entry in the SystemDictionary
1491 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
1492 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1493 SystemDictionary_lock->notify_all();
1494 #ifdef ASSERT
1495 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1496 assert(check != NULL, "definer missed recording success");
1497 #endif
1498 return(instanceKlassHandle(THREAD, probe->instance_klass()));
1499 } else {
1500 // This thread will define the class (even if earlier thread tried and had an error)
1501 probe->set_definer(THREAD);
1502 }
1503 }
1504
1505 define_instance_class(k, THREAD);
1506
1507 Handle linkage_exception = Handle(); // null handle
1508
1509 // definer must notify any waiting threads
1510 {
1511 MutexLocker mu(SystemDictionary_lock, THREAD);
1512 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1513 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1514 if (probe != NULL) {
1515 if (HAS_PENDING_EXCEPTION) {
1516 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1517 CLEAR_PENDING_EXCEPTION;
1518 } else {
1519 probe->set_instance_klass(k());
1520 }
1521 probe->set_definer(NULL);
1522 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1523 SystemDictionary_lock->notify_all();
1524 }
1525 }
1526
1527 // Can't throw exception while holding lock due to rank ordering
1528 if (linkage_exception() != NULL) {
1529 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
1530 }
1531
1532 return k;
1533 }
1534 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1535 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1536 if (class_loader.is_null()) {
1537 return Handle(THREAD, _system_loader_lock_obj);
1538 } else {
1539 return class_loader;
1540 }
1541 }
1542
1543 // This method is added to check how often we have to wait to grab loader
1544 // lock. The results are being recorded in the performance counters defined in
1545 // ClassLoader::_sync_systemLoaderLockContentionRate and
1546 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1547 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1548 if (!UsePerfData) {
1549 return;
1550 }
1551
1552 assert(!loader_lock.is_null(), "NULL lock object");
1553
1554 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1555 == ObjectSynchronizer::owner_other) {
1556 // contention will likely happen, so increment the corresponding
1557 // contention counter.
1558 if (loader_lock() == _system_loader_lock_obj) {
1559 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1560 } else {
1561 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1562 }
1563 }
1564 }
1565
1566 // ----------------------------------------------------------------------------
1567 // Lookup
1568
1569 Klass* SystemDictionary::find_class(int index, unsigned int hash,
1570 Symbol* class_name,
1571 ClassLoaderData* loader_data) {
1572 assert_locked_or_safepoint(SystemDictionary_lock);
1573 assert (index == dictionary()->index_for(class_name, loader_data),
1574 "incorrect index?");
1575
1576 Klass* k = dictionary()->find_class(index, hash, class_name, loader_data);
1577 return k;
1578 }
1579
1580
1581 // Basic find on classes in the midst of being loaded
1582 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1583 ClassLoaderData* loader_data) {
1584 assert_locked_or_safepoint(SystemDictionary_lock);
1585 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
1586 int p_index = placeholders()->hash_to_index(p_hash);
1587 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1588 }
1589
1590
1591 // Used for assertions and verification only
1592 Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1593 #ifndef ASSERT
1594 guarantee(VerifyBeforeGC ||
1595 VerifyDuringGC ||
1596 VerifyBeforeExit ||
1597 VerifyDuringStartup ||
1598 VerifyAfterGC, "too expensive");
1599 #endif
1600 assert_locked_or_safepoint(SystemDictionary_lock);
1601
1602 // First look in the loaded class array
1603 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
1604 int d_index = dictionary()->hash_to_index(d_hash);
1605 return find_class(d_index, d_hash, class_name, loader_data);
1606 }
1607
1608
1609 // Get the next class in the diictionary.
1610 Klass* SystemDictionary::try_get_next_class() {
1611 return dictionary()->try_get_next_class();
1612 }
1613
1614
1615 // ----------------------------------------------------------------------------
1616 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1617 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1618 // before a new class is used.
1619
1620 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
1621 assert(k.not_null(), "just checking");
1622 assert_locked_or_safepoint(Compile_lock);
1623
1624 // Link into hierachy. Make sure the vtables are initialized before linking into
1625 k->append_to_sibling_list(); // add to superklass/sibling list
1626 k->process_interfaces(THREAD); // handle all "implements" declarations
1627 k->set_init_state(InstanceKlass::loaded);
1628 // Now flush all code that depended on old class hierarchy.
1629 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1630 // Also, first reinitialize vtable because it may have gotten out of synch
1631 // while the new class wasn't connected to the class hierarchy.
1632 Universe::flush_dependents_on(k);
1633 }
1634
1635 // ----------------------------------------------------------------------------
1636 // GC support
1637
1638 // Following roots during mark-sweep is separated in two phases.
1639 //
1640 // The first phase follows preloaded classes and all other system
1641 // classes, since these will never get unloaded anyway.
1642 //
1643 // The second phase removes (unloads) unreachable classes from the
1644 // system dictionary and follows the remaining classes' contents.
1645
1646 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1647 roots_oops_do(blk, NULL);
1648 }
1649
1650 void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
1651 // Follow all system classes and temporary placeholders in dictionary
1652 dictionary()->always_strong_classes_do(closure);
1653
1654 // Placeholders. These represent classes we're actively loading.
1655 placeholders()->classes_do(closure);
1656 }
1657
1658 // Calculate a "good" systemdictionary size based
1659 // on predicted or current loaded classes count
1660 int SystemDictionary::calculate_systemdictionary_size(int classcount) {
1661 int newsize = _old_default_sdsize;
1662 if ((classcount > 0) && !DumpSharedSpaces) {
1663 int desiredsize = classcount/_average_depth_goal;
1664 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
1665 newsize = _primelist[++_sdgeneration]) {
1666 if (desiredsize <= newsize) {
1667 break;
1668 }
1669 }
1670 }
1671 return newsize;
1672 }
1673
1674 #ifdef ASSERT
1675 class VerifySDReachableAndLiveClosure : public OopClosure {
1676 private:
1677 BoolObjectClosure* _is_alive;
1678
1679 template <class T> void do_oop_work(T* p) {
1680 oop obj = oopDesc::load_decode_heap_oop(p);
1681 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
1682 }
1683
1684 public:
1685 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
1686
1687 virtual void do_oop(oop* p) { do_oop_work(p); }
1688 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1689 };
1690 #endif
1691
1692 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1693 // Note: anonymous classes are not in the SD.
1694 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
1695 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1696 bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive);
1697 if (unloading_occurred) {
1698 dictionary()->do_unloading();
1699 constraints()->purge_loader_constraints();
1700 resolution_errors()->purge_resolution_errors();
1701 }
1702 // Oops referenced by the system dictionary may get unreachable independently
1703 // of the class loader (eg. cached protection domain oops). So we need to
1704 // explicitly unlink them here instead of in Dictionary::do_unloading.
1705 dictionary()->unlink(is_alive);
1706 #ifdef ASSERT
1707 VerifySDReachableAndLiveClosure cl(is_alive);
1708 dictionary()->oops_do(&cl);
1709 #endif
1710 return unloading_occurred;
1711 }
1712
1713 void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
1714 strong->do_oop(&_java_system_loader);
1715 strong->do_oop(&_system_loader_lock_obj);
1716 CDS_ONLY(SystemDictionaryShared::roots_oops_do(strong);)
1717
1718 // Adjust dictionary
1719 dictionary()->roots_oops_do(strong, weak);
1720
1721 // Visit extra methods
1722 invoke_method_table()->oops_do(strong);
1723 }
1724
1725 void SystemDictionary::oops_do(OopClosure* f) {
1726 f->do_oop(&_java_system_loader);
1727 f->do_oop(&_system_loader_lock_obj);
1728 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1729
1730 // Adjust dictionary
1731 dictionary()->oops_do(f);
1732
1733 // Visit extra methods
1734 invoke_method_table()->oops_do(f);
1735 }
1736
1737 // Extended Class redefinition support.
1738 // If one of these classes is replaced, we need to replace it in these places.
1739 // KlassClosure::do_klass should take the address of a class but we can
1740 // change that later.
1741 void SystemDictionary::preloaded_classes_do(KlassClosure* f) {
1742 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
1743 f->do_klass(_well_known_klasses[k]);
1744 }
1745
1746 {
1747 for (int i = 0; i < T_VOID+1; i++) {
1748 if (_box_klasses[i] != NULL) {
1749 assert(i >= T_BOOLEAN, "checking");
1750 f->do_klass(_box_klasses[i]);
1751 }
1752 }
1753 }
1754
1755 FilteredFieldsMap::classes_do(f);
1756 }
1757
1758 void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) {
1759 f->do_klass(_abstract_ownable_synchronizer_klass);
1760 }
1761
1762 // Just the classes from defining class loaders
1763 // Don't iterate over placeholders
1764 void SystemDictionary::classes_do(void f(Klass*)) {
1765 dictionary()->classes_do(f);
1766 }
1767
1768 // Added for initialize_itable_for_klass
1769 // Just the classes from defining class loaders
1770 // Don't iterate over placeholders
1771 void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
1772 dictionary()->classes_do(f, CHECK);
1773 }
1774
1775 // All classes, and their class loaders
1776 // Don't iterate over placeholders
1777 void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
1778 dictionary()->classes_do(f);
1779 }
1780
1781 void SystemDictionary::placeholders_do(void f(Symbol*)) {
1782 placeholders()->entries_do(f);
1783 }
1784
1785 void SystemDictionary::methods_do(void f(Method*)) {
1786 dictionary()->methods_do(f);
1787 invoke_method_table()->methods_do(f);
1788 }
1789
1790 void SystemDictionary::remove_classes_in_error_state() {
1791 dictionary()->remove_classes_in_error_state();
1792 }
1793
1794 // ----------------------------------------------------------------------------
1795 // Lazily load klasses
1796
1797 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
1798 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later");
1799
1800 // if multiple threads calling this function, only one thread will load
1801 // the class. The other threads will find the loaded version once the
1802 // class is loaded.
1803 Klass* aos = _abstract_ownable_synchronizer_klass;
1804 if (aos == NULL) {
1805 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
1806 // Force a fence to prevent any read before the write completes
1807 OrderAccess::fence();
1808 _abstract_ownable_synchronizer_klass = k;
1809 }
1810 }
1811
1812 // ----------------------------------------------------------------------------
1813 // Initialization
1814
1815 void SystemDictionary::initialize(TRAPS) {
1816 // Allocate arrays
1817 assert(dictionary() == NULL,
1818 "SystemDictionary should only be initialized once");
1819 _sdgeneration = 0;
1820 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
1821 _placeholders = new PlaceholderTable(_nof_buckets);
1822 _number_of_modifications = 0;
1823 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1824 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1825 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
1826
1827 // Allocate private object used as system class loader lock
1828 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
1829 // Initialize basic classes
1830 initialize_preloaded_classes(CHECK);
1831 }
1832
1833 // Compact table of directions on the initialization of klasses:
1834 static const short wk_init_info[] = {
1835 #define WK_KLASS_INIT_INFO(name, symbol, option) \
1836 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
1837 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
1838 | (int)SystemDictionary::option ),
1839 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1840 #undef WK_KLASS_INIT_INFO
1841 0
1842 };
1843
1844 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
1845 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1846 int info = wk_init_info[id - FIRST_WKID];
1847 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1848 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1849 Klass** klassp = &_well_known_klasses[id];
1850 bool must_load = (init_opt < SystemDictionary::Opt);
1851 if ((*klassp) == NULL) {
1852 if (must_load) {
1853 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class
1854 } else {
1855 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass
1856 }
1857 }
1858 return ((*klassp) != NULL);
1859 }
1860
1861 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1862 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1863 for (int id = (int)start_id; id < (int)limit_id; id++) {
1864 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1865 int info = wk_init_info[id - FIRST_WKID];
1866 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1867 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
1868
1869 initialize_wk_klass((WKID)id, opt, CHECK);
1870 }
1871
1872 // move the starting value forward to the limit:
1873 start_id = limit_id;
1874 }
1875
1876 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
1877 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
1878 // Preload commonly used klasses
1879 WKID scan = FIRST_WKID;
1880 // first do Object, then String, Class
1881 if (UseSharedSpaces) {
1882 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
1883 // Initialize the constant pool for the Object_class
1884 InstanceKlass* ik = InstanceKlass::cast(Object_klass());
1885 ik->constants()->restore_unshareable_info(CHECK);
1886 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1887 } else {
1888 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1889 }
1890
1891 // Calculate offsets for String and Class classes since they are loaded and
1892 // can be used after this point.
1893 java_lang_String::compute_offsets();
1894 java_lang_Class::compute_offsets();
1895
1896 // Fixup mirrors for classes loaded before java.lang.Class.
1897 // These calls iterate over the objects currently in the perm gen
1898 // so calling them at this point is matters (not before when there
1899 // are fewer objects and not later after there are more objects
1900 // in the perm gen.
1901 Universe::initialize_basic_type_mirrors(CHECK);
1902 Universe::fixup_mirrors(CHECK);
1903
1904 // do a bunch more:
1905 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
1906
1907 // Preload ref klasses and set reference types
1908 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
1909 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
1910
1911 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
1912 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
1913 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
1914 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
1915 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
1916
1917 // JSR 292 classes
1918 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
1919 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
1920 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
1921 if (EnableInvokeDynamic) {
1922 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
1923 } else {
1924 // Skip the JSR 292 classes, if not enabled.
1925 scan = WKID(jsr292_group_end + 1);
1926 }
1927
1928 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK);
1929
1930 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
1931 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
1932 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
1933 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
1934 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
1935 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
1936 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
1937 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
1938 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
1939 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
1940
1941 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
1942 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
1943 _has_loadClassInternal = (method != NULL);
1944 }
1945 { // Compute whether we should use checkPackageAccess or NOT
1946 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
1947 _has_checkPackageAccess = (method != NULL);
1948 }
1949 }
1950
1951 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
1952 // If so, returns the basic type it holds. If not, returns T_OBJECT.
1953 BasicType SystemDictionary::box_klass_type(Klass* k) {
1954 assert(k != NULL, "");
1955 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
1956 if (_box_klasses[i] == k)
1957 return (BasicType)i;
1958 }
1959 return T_OBJECT;
1960 }
1961
1962 // Constraints on class loaders. The details of the algorithm can be
1963 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
1964 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
1965 // that the system dictionary needs to maintain a set of contraints that
1966 // must be satisfied by all classes in the dictionary.
1967 // if defining is true, then LinkageError if already in systemDictionary
1968 // if initiating loader, then ok if InstanceKlass matches existing entry
1969
1970 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
1971 instanceKlassHandle k,
1972 Handle class_loader, bool defining,
1973 TRAPS) {
1974 const char *linkage_error = NULL;
1975 {
1976 Symbol* name = k->name();
1977 ClassLoaderData *loader_data = class_loader_data(class_loader);
1978
1979 MutexLocker mu(SystemDictionary_lock, THREAD);
1980
1981 Klass* check = find_class(d_index, d_hash, name, loader_data);
1982 if (check != (Klass*)NULL) {
1983 // if different InstanceKlass - duplicate class definition,
1984 // else - ok, class loaded by a different thread in parallel,
1985 // we should only have found it if it was done loading and ok to use
1986 // system dictionary only holds instance classes, placeholders
1987 // also holds array classes
1988
1989 assert(check->oop_is_instance(), "noninstance in systemdictionary");
1990 if ((defining == true) || (k() != check)) {
1991 linkage_error = "loader (instance of %s): attempted duplicate class "
1992 "definition for name: \"%s\"";
1993 } else {
1994 return;
1995 }
1996 }
1997
1998 #ifdef ASSERT
1999 Symbol* ph_check = find_placeholder(name, loader_data);
2000 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2001 #endif
2002
2003 if (linkage_error == NULL) {
2004 if (constraints()->check_or_update(k, class_loader, name) == false) {
2005 linkage_error = "loader constraint violation: loader (instance of %s)"
2006 " previously initiated loading for a different type with name \"%s\"";
2007 }
2008 }
2009 }
2010
2011 // Throw error now if needed (cannot throw while holding
2012 // SystemDictionary_lock because of rank ordering)
2013
2014 if (linkage_error) {
2015 ResourceMark rm(THREAD);
2016 const char* class_loader_name = loader_name(class_loader());
2017 char* type_name = k->name()->as_C_string();
2018 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) +
2019 strlen(type_name);
2020 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
2021 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name);
2022 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
2023 }
2024 }
2025
2026
2027 // Update system dictionary - done after check_constraint and add_to_hierachy
2028 // have been called.
2029 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
2030 int p_index, unsigned int p_hash,
2031 instanceKlassHandle k,
2032 Handle class_loader,
2033 TRAPS) {
2034 // Compile_lock prevents systemDictionary updates during compilations
2035 assert_locked_or_safepoint(Compile_lock);
2036 Symbol* name = k->name();
2037 ClassLoaderData *loader_data = class_loader_data(class_loader);
2038
2039 {
2040 MutexLocker mu1(SystemDictionary_lock, THREAD);
2041
2042 // See whether biased locking is enabled and if so set it for this
2043 // klass.
2044 // Note that this must be done past the last potential blocking
2045 // point / safepoint. We enable biased locking lazily using a
2046 // VM_Operation to iterate the SystemDictionary and installing the
2047 // biasable mark word into each InstanceKlass's prototype header.
2048 // To avoid race conditions where we accidentally miss enabling the
2049 // optimization for one class in the process of being added to the
2050 // dictionary, we must not safepoint after the test of
2051 // BiasedLocking::enabled().
2052 if (UseBiasedLocking && BiasedLocking::enabled()) {
2053 // Set biased locking bit for all loaded classes; it will be
2054 // cleared if revocation occurs too often for this type
2055 // NOTE that we must only do this when the class is initally
2056 // defined, not each time it is referenced from a new class loader
2057 if (k->class_loader() == class_loader()) {
2058 k->set_prototype_header(markOopDesc::biased_locking_prototype());
2059 }
2060 }
2061
2062 // Make a new system dictionary entry.
2063 Klass* sd_check = find_class(d_index, d_hash, name, loader_data);
2064 if (sd_check == NULL) {
2065 dictionary()->add_klass(name, loader_data, k);
2066 notice_modification();
2067 }
2068 #ifdef ASSERT
2069 sd_check = find_class(d_index, d_hash, name, loader_data);
2070 assert (sd_check != NULL, "should have entry in system dictionary");
2071 // Note: there may be a placeholder entry: for circularity testing
2072 // or for parallel defines
2073 #endif
2074 SystemDictionary_lock->notify_all();
2075 }
2076 }
2077
2078
2079 // Try to find a class name using the loader constraints. The
2080 // loader constraints might know about a class that isn't fully loaded
2081 // yet and these will be ignored.
2082 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2083 Symbol* class_name, Handle class_loader, TRAPS) {
2084
2085 // First see if it has been loaded directly.
2086 // Force the protection domain to be null. (This removes protection checks.)
2087 Handle no_protection_domain;
2088 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2089 no_protection_domain, CHECK_NULL);
2090 if (klass != NULL)
2091 return klass;
2092
2093 // Now look to see if it has been loaded elsewhere, and is subject to
2094 // a loader constraint that would require this loader to return the
2095 // klass that is already loaded.
2096 if (FieldType::is_array(class_name)) {
2097 // For array classes, their Klass*s are not kept in the
2098 // constraint table. The element Klass*s are.
2099 FieldArrayInfo fd;
2100 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
2101 if (t != T_OBJECT) {
2102 klass = Universe::typeArrayKlassObj(t);
2103 } else {
2104 MutexLocker mu(SystemDictionary_lock, THREAD);
2105 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
2106 }
2107 // If element class already loaded, allocate array klass
2108 if (klass != NULL) {
2109 klass = klass->array_klass_or_null(fd.dimension());
2110 }
2111 } else {
2112 MutexLocker mu(SystemDictionary_lock, THREAD);
2113 // Non-array classes are easy: simply check the constraint table.
2114 klass = constraints()->find_constrained_klass(class_name, class_loader);
2115 }
2116
2117 return klass;
2118 }
2119
2120
2121 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2122 Handle class_loader1,
2123 Handle class_loader2,
2124 Thread* THREAD) {
2125 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2126 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2127
2128 Symbol* constraint_name = NULL;
2129 if (!FieldType::is_array(class_name)) {
2130 constraint_name = class_name;
2131 } else {
2132 // For array classes, their Klass*s are not kept in the
2133 // constraint table. The element classes are.
2134 FieldArrayInfo fd;
2135 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
2136 // primitive types always pass
2137 if (t != T_OBJECT) {
2138 return true;
2139 } else {
2140 constraint_name = fd.object_key();
2141 }
2142 }
2143 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
2144 int d_index1 = dictionary()->hash_to_index(d_hash1);
2145
2146 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
2147 int d_index2 = dictionary()->hash_to_index(d_hash2);
2148 {
2149 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2150
2151 // Better never do a GC while we're holding these oops
2152 No_Safepoint_Verifier nosafepoint;
2153
2154 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
2155 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
2156 return constraints()->add_entry(constraint_name, klass1, class_loader1,
2157 klass2, class_loader2);
2158 }
2159 }
2160
2161 // Add entry to resolution error table to record the error when the first
2162 // attempt to resolve a reference to a class has failed.
2163 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, Symbol* error) {
2164 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2165 int index = resolution_errors()->hash_to_index(hash);
2166 {
2167 MutexLocker ml(SystemDictionary_lock, Thread::current());
2168 resolution_errors()->add_entry(index, hash, pool, which, error);
2169 }
2170 }
2171
2172 // Delete a resolution error for RedefineClasses for a constant pool is going away
2173 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2174 resolution_errors()->delete_entry(pool);
2175 }
2176
2177 // Lookup resolution error table. Returns error if found, otherwise NULL.
2178 Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) {
2179 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2180 int index = resolution_errors()->hash_to_index(hash);
2181 {
2182 MutexLocker ml(SystemDictionary_lock, Thread::current());
2183 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2184 return (entry != NULL) ? entry->error() : (Symbol*)NULL;
2185 }
2186 }
2187
2188
2189 // Signature constraints ensure that callers and callees agree about
2190 // the meaning of type names in their signatures. This routine is the
2191 // intake for constraints. It collects them from several places:
2192 //
2193 // * LinkResolver::resolve_method (if check_access is true) requires
2194 // that the resolving class (the caller) and the defining class of
2195 // the resolved method (the callee) agree on each type in the
2196 // method's signature.
2197 //
2198 // * LinkResolver::resolve_interface_method performs exactly the same
2199 // checks.
2200 //
2201 // * LinkResolver::resolve_field requires that the constant pool
2202 // attempting to link to a field agree with the field's defining
2203 // class about the type of the field signature.
2204 //
2205 // * klassVtable::initialize_vtable requires that, when a class
2206 // overrides a vtable entry allocated by a superclass, that the
2207 // overriding method (i.e., the callee) agree with the superclass
2208 // on each type in the method's signature.
2209 //
2210 // * klassItable::initialize_itable requires that, when a class fills
2211 // in its itables, for each non-abstract method installed in an
2212 // itable, the method (i.e., the callee) agree with the interface
2213 // on each type in the method's signature.
2214 //
2215 // All those methods have a boolean (check_access, checkconstraints)
2216 // which turns off the checks. This is used from specialized contexts
2217 // such as bootstrapping, dumping, and debugging.
2218 //
2219 // No direct constraint is placed between the class and its
2220 // supertypes. Constraints are only placed along linked relations
2221 // between callers and callees. When a method overrides or implements
2222 // an abstract method in a supertype (superclass or interface), the
2223 // constraints are placed as if the supertype were the caller to the
2224 // overriding method. (This works well, since callers to the
2225 // supertype have already established agreement between themselves and
2226 // the supertype.) As a result of all this, a class can disagree with
2227 // its supertype about the meaning of a type name, as long as that
2228 // class neither calls a relevant method of the supertype, nor is
2229 // called (perhaps via an override) from the supertype.
2230 //
2231 //
2232 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2233 //
2234 // Make sure all class components (including arrays) in the given
2235 // signature will be resolved to the same class in both loaders.
2236 // Returns the name of the type that failed a loader constraint check, or
2237 // NULL if no constraint failed. No exception except OOME is thrown.
2238 // Arrays are not added to the loader constraint table, their elements are.
2239 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2240 Handle loader1, Handle loader2,
2241 bool is_method, TRAPS) {
2242 // Nothing to do if loaders are the same.
2243 if (loader1() == loader2()) {
2244 return NULL;
2245 }
2246
2247 SignatureStream sig_strm(signature, is_method);
2248 while (!sig_strm.is_done()) {
2249 if (sig_strm.is_object()) {
2250 Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
2251 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2252 return sig;
2253 }
2254 }
2255 sig_strm.next();
2256 }
2257 return NULL;
2258 }
2259
2260
2261 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2262 Symbol* signature,
2263 TRAPS) {
2264 methodHandle empty;
2265 assert(EnableInvokeDynamic, "");
2266 assert(MethodHandles::is_signature_polymorphic(iid) &&
2267 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2268 iid != vmIntrinsics::_invokeGeneric,
2269 err_msg("must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid)));
2270
2271 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2272 int index = invoke_method_table()->hash_to_index(hash);
2273 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2274 methodHandle m;
2275 if (spe == NULL || spe->method() == NULL) {
2276 spe = NULL;
2277 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2278 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
2279 if (!Arguments::is_interpreter_only()) {
2280 // Generate a compiled form of the MH intrinsic.
2281 AdapterHandlerLibrary::create_native_wrapper(m);
2282 // Check if have the compiled code.
2283 if (!m->has_compiled_code()) {
2284 THROW_MSG_(vmSymbols::java_lang_VirtualMachineError(),
2285 "out of space in CodeCache for method handle intrinsic", empty);
2286 }
2287 }
2288 // Now grab the lock. We might have to throw away the new method,
2289 // if a racing thread has managed to install one at the same time.
2290 {
2291 MutexLocker ml(SystemDictionary_lock, THREAD);
2292 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2293 if (spe == NULL)
2294 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2295 if (spe->method() == NULL)
2296 spe->set_method(m());
2297 }
2298 }
2299
2300 assert(spe != NULL && spe->method() != NULL, "");
2301 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2302 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2303 "MH intrinsic invariant");
2304 return spe->method();
2305 }
2306
2307 // Helper for unpacking the return value from linkMethod and linkCallSite.
2308 static methodHandle unpack_method_and_appendix(Handle mname,
2309 KlassHandle accessing_klass,
2310 objArrayHandle appendix_box,
2311 Handle* appendix_result,
2312 TRAPS) {
2313 methodHandle empty;
2314 if (mname.not_null()) {
2315 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
2316 if (vmtarget != NULL && vmtarget->is_method()) {
2317 Method* m = (Method*)vmtarget;
2318 oop appendix = appendix_box->obj_at(0);
2319 if (TraceMethodHandles) {
2320 #ifndef PRODUCT
2321 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2322 m->print();
2323 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2324 tty->cr();
2325 #endif //PRODUCT
2326 }
2327 (*appendix_result) = Handle(THREAD, appendix);
2328 // the target is stored in the cpCache and if a reference to this
2329 // MethodName is dropped we need a way to make sure the
2330 // class_loader containing this method is kept alive.
2331 // FIXME: the appendix might also preserve this dependency.
2332 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data();
2333 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
2334 return methodHandle(THREAD, m);
2335 }
2336 }
2337 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
2338 return empty;
2339 }
2340
2341 methodHandle SystemDictionary::find_method_handle_invoker(Symbol* name,
2342 Symbol* signature,
2343 KlassHandle accessing_klass,
2344 Handle *appendix_result,
2345 Handle *method_type_result,
2346 TRAPS) {
2347 methodHandle empty;
2348 assert(EnableInvokeDynamic, "");
2349 assert(!THREAD->is_Compiler_thread(), "");
2350 Handle method_type =
2351 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
2352 if (false) { // FIXME: Decide if the Java upcall should resolve signatures.
2353 method_type = java_lang_String::create_from_symbol(signature, CHECK_(empty));
2354 }
2355
2356 KlassHandle mh_klass = SystemDictionary::MethodHandle_klass();
2357 int ref_kind = JVM_REF_invokeVirtual;
2358 Handle name_str = StringTable::intern(name, CHECK_(empty));
2359 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2360 assert(appendix_box->obj_at(0) == NULL, "");
2361
2362 // This should not happen. JDK code should take care of that.
2363 if (accessing_klass.is_null() || method_type.is_null()) {
2364 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
2365 }
2366
2367 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2368 JavaCallArguments args;
2369 args.push_oop(accessing_klass()->java_mirror());
2370 args.push_int(ref_kind);
2371 args.push_oop(mh_klass()->java_mirror());
2372 args.push_oop(name_str());
2373 args.push_oop(method_type());
2374 args.push_oop(appendix_box());
2375 JavaValue result(T_OBJECT);
2376 JavaCalls::call_static(&result,
2377 SystemDictionary::MethodHandleNatives_klass(),
2378 vmSymbols::linkMethod_name(),
2379 vmSymbols::linkMethod_signature(),
2380 &args, CHECK_(empty));
2381 Handle mname(THREAD, (oop) result.get_jobject());
2382 (*method_type_result) = method_type;
2383 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2384 }
2385
2386
2387 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2388 // signature, as interpreted relative to the given class loader.
2389 // Because of class loader constraints, all method handle usage must be
2390 // consistent with this loader.
2391 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2392 KlassHandle accessing_klass,
2393 TRAPS) {
2394 Handle empty;
2395 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2396 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2397 int index = invoke_method_table()->hash_to_index(hash);
2398 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2399 if (spe != NULL && spe->method_type() != NULL) {
2400 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2401 return Handle(THREAD, spe->method_type());
2402 } else if (THREAD->is_Compiler_thread()) {
2403 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2404 return Handle(); // do not attempt from within compiler, unless it was cached
2405 }
2406
2407 Handle class_loader, protection_domain;
2408 bool is_on_bcp = true; // keep this true as long as we can materialize from the boot classloader
2409 int npts = ArgumentCount(signature).size();
2410 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2411 int arg = 0;
2412 Handle rt; // the return type from the signature
2413 ResourceMark rm(THREAD);
2414 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2415 oop mirror = NULL;
2416 if (is_on_bcp) {
2417 // Note: class_loader & protection_domain are both null at this point.
2418 mirror = ss.as_java_mirror(class_loader, protection_domain,
2419 SignatureStream::ReturnNull, CHECK_(empty));
2420 if (mirror == NULL) {
2421 // fall back from BCP to accessing_klass
2422 if (accessing_klass.not_null()) {
2423 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader());
2424 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain());
2425 }
2426 is_on_bcp = false;
2427 }
2428 }
2429 if (!is_on_bcp) {
2430 // Resolve, throwing a real error if it doesn't work.
2431 mirror = ss.as_java_mirror(class_loader, protection_domain,
2432 SignatureStream::NCDFError, CHECK_(empty));
2433 }
2434 if (ss.at_return_type())
2435 rt = Handle(THREAD, mirror);
2436 else
2437 pts->obj_at_put(arg++, mirror);
2438
2439 // Check accessibility.
2440 if (ss.is_object() && accessing_klass.not_null()) {
2441 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2442 mirror = NULL; // safety
2443 // Emulate ConstantPool::verify_constant_pool_resolve.
2444 if (sel_klass->oop_is_objArray())
2445 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
2446 if (sel_klass->oop_is_instance()) {
2447 KlassHandle sel_kh(THREAD, sel_klass);
2448 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty));
2449 }
2450 }
2451 }
2452 assert(arg == npts, "");
2453
2454 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType
2455 JavaCallArguments args(Handle(THREAD, rt()));
2456 args.push_oop(pts());
2457 JavaValue result(T_OBJECT);
2458 JavaCalls::call_static(&result,
2459 SystemDictionary::MethodHandleNatives_klass(),
2460 vmSymbols::findMethodHandleType_name(),
2461 vmSymbols::findMethodHandleType_signature(),
2462 &args, CHECK_(empty));
2463 Handle method_type(THREAD, (oop) result.get_jobject());
2464
2465 if (is_on_bcp) {
2466 // We can cache this MethodType inside the JVM.
2467 MutexLocker ml(SystemDictionary_lock, THREAD);
2468 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2469 if (spe == NULL)
2470 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2471 if (spe->method_type() == NULL) {
2472 spe->set_method_type(method_type());
2473 }
2474 }
2475
2476 // report back to the caller with the MethodType
2477 return method_type;
2478 }
2479
2480 // Ask Java code to find or construct a method handle constant.
2481 Handle SystemDictionary::link_method_handle_constant(KlassHandle caller,
2482 int ref_kind, //e.g., JVM_REF_invokeVirtual
2483 KlassHandle callee,
2484 Symbol* name_sym,
2485 Symbol* signature,
2486 TRAPS) {
2487 Handle empty;
2488 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
2489 Handle type;
2490 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
2491 type = find_method_handle_type(signature, caller, CHECK_(empty));
2492 } else if (caller.is_null()) {
2493 // This should not happen. JDK code should take care of that.
2494 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2495 } else {
2496 ResourceMark rm(THREAD);
2497 SignatureStream ss(signature, false);
2498 if (!ss.is_done()) {
2499 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(),
2500 SignatureStream::NCDFError, CHECK_(empty));
2501 type = Handle(THREAD, mirror);
2502 ss.next();
2503 if (!ss.is_done()) type = Handle(); // error!
2504 }
2505 }
2506 if (type.is_null()) {
2507 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
2508 }
2509
2510 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2511 JavaCallArguments args;
2512 args.push_oop(caller->java_mirror()); // the referring class
2513 args.push_int(ref_kind);
2514 args.push_oop(callee->java_mirror()); // the target class
2515 args.push_oop(name());
2516 args.push_oop(type());
2517 JavaValue result(T_OBJECT);
2518 JavaCalls::call_static(&result,
2519 SystemDictionary::MethodHandleNatives_klass(),
2520 vmSymbols::linkMethodHandleConstant_name(),
2521 vmSymbols::linkMethodHandleConstant_signature(),
2522 &args, CHECK_(empty));
2523 return Handle(THREAD, (oop) result.get_jobject());
2524 }
2525
2526 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given
2527 // name and signature, as interpreted relative to the given class loader.
2528 methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller,
2529 Handle bootstrap_specifier,
2530 Symbol* name,
2531 Symbol* type,
2532 Handle *appendix_result,
2533 Handle *method_type_result,
2534 TRAPS) {
2535 methodHandle empty;
2536 Handle bsm, info;
2537 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
2538 bsm = bootstrap_specifier;
2539 } else {
2540 assert(bootstrap_specifier->is_objArray(), "");
2541 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
2542 int len = args->length();
2543 assert(len >= 1, "");
2544 bsm = Handle(THREAD, args->obj_at(0));
2545 if (len > 1) {
2546 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
2547 for (int i = 1; i < len; i++)
2548 args1->obj_at_put(i-1, args->obj_at(i));
2549 info = Handle(THREAD, args1);
2550 }
2551 }
2552 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
2553 "caller must supply a valid BSM");
2554
2555 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
2556 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
2557
2558 // This should not happen. JDK code should take care of that.
2559 if (caller.is_null() || method_type.is_null()) {
2560 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
2561 }
2562
2563 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2564 assert(appendix_box->obj_at(0) == NULL, "");
2565
2566 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
2567 JavaCallArguments args;
2568 args.push_oop(caller->java_mirror());
2569 args.push_oop(bsm());
2570 args.push_oop(method_name());
2571 args.push_oop(method_type());
2572 args.push_oop(info());
2573 args.push_oop(appendix_box);
2574 JavaValue result(T_OBJECT);
2575 JavaCalls::call_static(&result,
2576 SystemDictionary::MethodHandleNatives_klass(),
2577 vmSymbols::linkCallSite_name(),
2578 vmSymbols::linkCallSite_signature(),
2579 &args, CHECK_(empty));
2580 Handle mname(THREAD, (oop) result.get_jobject());
2581 (*method_type_result) = method_type;
2582 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
2583 }
2584
2585 // Since the identity hash code for symbols changes when the symbols are
2586 // moved from the regular perm gen (hash in the mark word) to the shared
2587 // spaces (hash is the address), the classes loaded into the dictionary
2588 // may be in the wrong buckets.
2589
2590 void SystemDictionary::reorder_dictionary() {
2591 dictionary()->reorder_dictionary();
2592 }
2593
2594
2595 void SystemDictionary::copy_buckets(char** top, char* end) {
2596 dictionary()->copy_buckets(top, end);
2597 }
2598
2599
2600 void SystemDictionary::copy_table(char** top, char* end) {
2601 dictionary()->copy_table(top, end);
2602 }
2603
2604
2605 void SystemDictionary::reverse() {
2606 dictionary()->reverse();
2607 }
2608
2609 int SystemDictionary::number_of_classes() {
2610 return dictionary()->number_of_entries();
2611 }
2612
2613
2614 // ----------------------------------------------------------------------------
2615 void SystemDictionary::print_shared(bool details) {
2616 shared_dictionary()->print(details);
2617 }
2618
2619 void SystemDictionary::print(bool details) {
2620 dictionary()->print(details);
2621
2622 // Placeholders
2623 GCMutexLocker mu(SystemDictionary_lock);
2624 placeholders()->print();
2625
2626 // loader constraints - print under SD_lock
2627 constraints()->print();
2628 }
2629
2630
2631 void SystemDictionary::verify() {
2632 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2633 guarantee(constraints() != NULL,
2634 "Verify of loader constraints failed");
2635 guarantee(dictionary()->number_of_entries() >= 0 &&
2636 placeholders()->number_of_entries() >= 0,
2637 "Verify of system dictionary failed");
2638
2639 // Verify dictionary
2640 dictionary()->verify();
2641
2642 GCMutexLocker mu(SystemDictionary_lock);
2643 placeholders()->verify();
2644
2645 // Verify constraint table
2646 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2647 constraints()->verify(dictionary(), placeholders());
2648 }
2649
2650 // utility function for class load event
2651 void SystemDictionary::post_class_load_event(const Ticks& start_time,
2652 instanceKlassHandle k,
2653 Handle initiating_loader) {
2654 #if INCLUDE_TRACE
2655 EventClassLoad event(UNTIMED);
2656 if (event.should_commit()) {
2657 event.set_starttime(start_time);
2658 event.set_loadedClass(k());
2659 oop defining_class_loader = k->class_loader();
2660 event.set_definingClassLoader(defining_class_loader != NULL ?
2661 defining_class_loader->klass() : (Klass*)NULL);
2662 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader();
2663 event.set_initiatingClassLoader(class_loader != NULL ?
2664 class_loader->klass() : (Klass*)NULL);
2665 event.commit();
2666 }
2667 #endif /* INCLUDE_TRACE */
2668 }
2669
2670 #ifndef PRODUCT
2671
2672 // statistics code
2673 class ClassStatistics: AllStatic {
2674 private:
2675 static int nclasses; // number of classes
2676 static int nmethods; // number of methods
2677 static int nmethoddata; // number of methodData
2678 static int class_size; // size of class objects in words
2679 static int method_size; // size of method objects in words
2680 static int debug_size; // size of debug info in methods
2681 static int methoddata_size; // size of methodData objects in words
2682
2683 static void do_class(Klass* k) {
2684 nclasses++;
2685 class_size += k->size();
2686 if (k->oop_is_instance()) {
2687 InstanceKlass* ik = (InstanceKlass*)k;
2688 class_size += ik->methods()->size();
2689 class_size += ik->constants()->size();
2690 class_size += ik->local_interfaces()->size();
2691 class_size += ik->transitive_interfaces()->size();
2692 // We do not have to count implementors, since we only store one!
2693 // SSS: How should these be accounted now that they have moved?
2694 // class_size += ik->fields()->length();
2695 }
2696 }
2697
2698 static void do_method(Method* m) {
2699 nmethods++;
2700 method_size += m->size();
2701 // class loader uses same objArray for empty vectors, so don't count these
2702 if (m->has_stackmap_table()) {
2703 method_size += m->stackmap_data()->size();
2704 }
2705
2706 MethodData* mdo = m->method_data();
2707 if (mdo != NULL) {
2708 nmethoddata++;
2709 methoddata_size += mdo->size();
2710 }
2711 }
2712
2713 public:
2714 static void print() {
2715 SystemDictionary::classes_do(do_class);
2716 SystemDictionary::methods_do(do_method);
2717 tty->print_cr("Class statistics:");
2718 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize);
2719 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods,
2720 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize);
2721 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize);
2722 }
2723 };
2724
2725
2726 int ClassStatistics::nclasses = 0;
2727 int ClassStatistics::nmethods = 0;
2728 int ClassStatistics::nmethoddata = 0;
2729 int ClassStatistics::class_size = 0;
2730 int ClassStatistics::method_size = 0;
2731 int ClassStatistics::debug_size = 0;
2732 int ClassStatistics::methoddata_size = 0;
2733
2734 void SystemDictionary::print_class_statistics() {
2735 ResourceMark rm;
2736 ClassStatistics::print();
2737 }
2738
2739
2740 class MethodStatistics: AllStatic {
2741 public:
2742 enum {
2743 max_parameter_size = 10
2744 };
2745 private:
2746
2747 static int _number_of_methods;
2748 static int _number_of_final_methods;
2749 static int _number_of_static_methods;
2750 static int _number_of_native_methods;
2751 static int _number_of_synchronized_methods;
2752 static int _number_of_profiled_methods;
2753 static int _number_of_bytecodes;
2754 static int _parameter_size_profile[max_parameter_size];
2755 static int _bytecodes_profile[Bytecodes::number_of_java_codes];
2756
2757 static void initialize() {
2758 _number_of_methods = 0;
2759 _number_of_final_methods = 0;
2760 _number_of_static_methods = 0;
2761 _number_of_native_methods = 0;
2762 _number_of_synchronized_methods = 0;
2763 _number_of_profiled_methods = 0;
2764 _number_of_bytecodes = 0;
2765 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0;
2766 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0;
2767 };
2768
2769 static void do_method(Method* m) {
2770 _number_of_methods++;
2771 // collect flag info
2772 if (m->is_final() ) _number_of_final_methods++;
2773 if (m->is_static() ) _number_of_static_methods++;
2774 if (m->is_native() ) _number_of_native_methods++;
2775 if (m->is_synchronized()) _number_of_synchronized_methods++;
2776 if (m->method_data() != NULL) _number_of_profiled_methods++;
2777 // collect parameter size info (add one for receiver, if any)
2778 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++;
2779 // collect bytecodes info
2780 {
2781 Thread *thread = Thread::current();
2782 HandleMark hm(thread);
2783 BytecodeStream s(methodHandle(thread, m));
2784 Bytecodes::Code c;
2785 while ((c = s.next()) >= 0) {
2786 _number_of_bytecodes++;
2787 _bytecodes_profile[c]++;
2788 }
2789 }
2790 }
2791
2792 public:
2793 static void print() {
2794 initialize();
2795 SystemDictionary::methods_do(do_method);
2796 // generate output
2797 tty->cr();
2798 tty->print_cr("Method statistics (static):");
2799 // flag distribution
2800 tty->cr();
2801 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods);
2802 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods);
2803 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods);
2804 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods);
2805 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods);
2806 // parameter size profile
2807 tty->cr();
2808 { int tot = 0;
2809 int avg = 0;
2810 for (int i = 0; i < max_parameter_size; i++) {
2811 int n = _parameter_size_profile[i];
2812 tot += n;
2813 avg += n*i;
2814 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods);
2815 }
2816 assert(tot == _number_of_methods, "should be the same");
2817 tty->print_cr(" %6d methods 100.0%%", _number_of_methods);
2818 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods);
2819 }
2820 // bytecodes profile
2821 tty->cr();
2822 { int tot = 0;
2823 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) {
2824 if (Bytecodes::is_defined(i)) {
2825 Bytecodes::Code c = Bytecodes::cast(i);
2826 int n = _bytecodes_profile[c];
2827 tot += n;
2828 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c));
2829 }
2830 }
2831 assert(tot == _number_of_bytecodes, "should be the same");
2832 tty->print_cr("%9d 100.000%%", _number_of_bytecodes);
2833 }
2834 tty->cr();
2835 }
2836 };
2837
2838 int MethodStatistics::_number_of_methods;
2839 int MethodStatistics::_number_of_final_methods;
2840 int MethodStatistics::_number_of_static_methods;
2841 int MethodStatistics::_number_of_native_methods;
2842 int MethodStatistics::_number_of_synchronized_methods;
2843 int MethodStatistics::_number_of_profiled_methods;
2844 int MethodStatistics::_number_of_bytecodes;
2845 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size];
2846 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes];
2847
2848
2849 void SystemDictionary::print_method_statistics() {
2850 MethodStatistics::print();
2851 }
2852
2853 #endif // PRODUCT