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