Mon, 17 Mar 2014 10:17:55 -0400
8035119: Fix exceptions to bytecode verification
Summary: Prevent ctor calls to super() and this() from avoidable code (try blocks, if stmts, etc.)
Reviewed-by: coleenp, acorn, mschoene
1 /*
2 * Copyright (c) 1997, 2013, 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.
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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
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23 */
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/dictionary.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "classfile/loaderConstraints.hpp"
30 #include "classfile/placeholders.hpp"
31 #include "classfile/resolutionErrors.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/vmSymbols.hpp"
34 #include "compiler/compileBroker.hpp"
35 #include "interpreter/bytecodeStream.hpp"
36 #include "interpreter/interpreter.hpp"
37 #include "memory/gcLocker.hpp"
38 #include "memory/oopFactory.hpp"
39 #include "oops/instanceKlass.hpp"
40 #include "oops/instanceRefKlass.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "oops/methodData.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "oops/oop.inline2.hpp"
46 #include "oops/typeArrayKlass.hpp"
47 #include "prims/jvmtiEnvBase.hpp"
48 #include "prims/methodHandles.hpp"
49 #include "runtime/biasedLocking.hpp"
50 #include "runtime/fieldType.hpp"
51 #include "runtime/handles.inline.hpp"
52 #include "runtime/java.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/mutexLocker.hpp"
55 #include "runtime/signature.hpp"
56 #include "services/classLoadingService.hpp"
57 #include "services/threadService.hpp"
58 #include "utilities/macros.hpp"
59 #include "utilities/ticks.hpp"
61 #if INCLUDE_TRACE
62 #include "trace/tracing.hpp"
63 #endif
65 Dictionary* SystemDictionary::_dictionary = NULL;
66 PlaceholderTable* SystemDictionary::_placeholders = NULL;
67 Dictionary* SystemDictionary::_shared_dictionary = NULL;
68 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
69 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
70 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
73 int SystemDictionary::_number_of_modifications = 0;
74 int SystemDictionary::_sdgeneration = 0;
75 const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
76 20201,40423,99991};
78 oop SystemDictionary::_system_loader_lock_obj = NULL;
80 Klass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
81 = { NULL /*, NULL...*/ };
83 Klass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
85 oop SystemDictionary::_java_system_loader = NULL;
87 bool SystemDictionary::_has_loadClassInternal = false;
88 bool SystemDictionary::_has_checkPackageAccess = false;
90 // lazily initialized klass variables
91 Klass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
94 // ----------------------------------------------------------------------------
95 // Java-level SystemLoader
97 oop SystemDictionary::java_system_loader() {
98 return _java_system_loader;
99 }
101 void SystemDictionary::compute_java_system_loader(TRAPS) {
102 KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass));
103 JavaValue result(T_OBJECT);
104 JavaCalls::call_static(&result,
105 KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)),
106 vmSymbols::getSystemClassLoader_name(),
107 vmSymbols::void_classloader_signature(),
108 CHECK);
110 _java_system_loader = (oop)result.get_jobject();
111 }
114 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
115 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
116 return ClassLoaderDataGraph::find_or_create(class_loader, CHECK_NULL);
117 }
119 // ----------------------------------------------------------------------------
120 // debugging
122 #ifdef ASSERT
124 // return true if class_name contains no '.' (internal format is '/')
125 bool SystemDictionary::is_internal_format(Symbol* class_name) {
126 if (class_name != NULL) {
127 ResourceMark rm;
128 char* name = class_name->as_C_string();
129 return strchr(name, '.') == NULL;
130 } else {
131 return true;
132 }
133 }
135 #endif
137 // ----------------------------------------------------------------------------
138 // Parallel class loading check
140 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
141 if (UnsyncloadClass || class_loader.is_null()) return true;
142 if (AlwaysLockClassLoader) return false;
143 return java_lang_ClassLoader::parallelCapable(class_loader());
144 }
145 // ----------------------------------------------------------------------------
146 // ParallelDefineClass flag does not apply to bootclass loader
147 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
148 if (class_loader.is_null()) return false;
149 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
150 return true;
151 }
152 return false;
153 }
155 /**
156 * Returns true if the passed class loader is the extension class loader.
157 */
158 bool SystemDictionary::is_ext_class_loader(Handle class_loader) {
159 if (class_loader.is_null()) {
160 return false;
161 }
162 return (class_loader->klass()->name() == vmSymbols::sun_misc_Launcher_ExtClassLoader());
163 }
165 // ----------------------------------------------------------------------------
166 // Resolving of classes
168 // Forwards to resolve_or_null
170 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
171 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
172 if (HAS_PENDING_EXCEPTION || klass == NULL) {
173 KlassHandle k_h(THREAD, klass);
174 // can return a null klass
175 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
176 }
177 return klass;
178 }
180 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) {
181 if (HAS_PENDING_EXCEPTION) {
182 // If we have a pending exception we forward it to the caller, unless throw_error is true,
183 // in which case we have to check whether the pending exception is a ClassNotFoundException,
184 // and if so convert it to a NoClassDefFoundError
185 // And chain the original ClassNotFoundException
186 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
187 ResourceMark rm(THREAD);
188 assert(klass_h() == NULL, "Should not have result with exception pending");
189 Handle e(THREAD, PENDING_EXCEPTION);
190 CLEAR_PENDING_EXCEPTION;
191 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
192 } else {
193 return NULL;
194 }
195 }
196 // Class not found, throw appropriate error or exception depending on value of throw_error
197 if (klass_h() == NULL) {
198 ResourceMark rm(THREAD);
199 if (throw_error) {
200 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
201 } else {
202 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
203 }
204 }
205 return (Klass*)klass_h();
206 }
209 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
210 bool throw_error, TRAPS)
211 {
212 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
213 }
216 // Forwards to resolve_instance_class_or_null
218 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
219 assert(!THREAD->is_Compiler_thread(),
220 err_msg("can not load classes with compiler thread: class=%s, classloader=%s",
221 class_name->as_C_string(),
222 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string()));
223 if (FieldType::is_array(class_name)) {
224 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
225 } else if (FieldType::is_obj(class_name)) {
226 ResourceMark rm(THREAD);
227 // Ignore wrapping L and ;.
228 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
229 class_name->utf8_length() - 2, CHECK_NULL);
230 return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL);
231 } else {
232 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
233 }
234 }
236 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
237 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
238 }
240 // Forwards to resolve_instance_class_or_null
242 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
243 Handle class_loader,
244 Handle protection_domain,
245 TRAPS) {
246 assert(FieldType::is_array(class_name), "must be array");
247 Klass* k = NULL;
248 FieldArrayInfo fd;
249 // dimension and object_key in FieldArrayInfo are assigned as a side-effect
250 // of this call
251 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
252 if (t == T_OBJECT) {
253 // naked oop "k" is OK here -- we assign back into it
254 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
255 class_loader,
256 protection_domain,
257 CHECK_NULL);
258 if (k != NULL) {
259 k = k->array_klass(fd.dimension(), CHECK_NULL);
260 }
261 } else {
262 k = Universe::typeArrayKlassObj(t);
263 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
264 }
265 return k;
266 }
269 // Must be called for any super-class or super-interface resolution
270 // during class definition to allow class circularity checking
271 // super-interface callers:
272 // parse_interfaces - for defineClass & jvmtiRedefineClasses
273 // super-class callers:
274 // ClassFileParser - for defineClass & jvmtiRedefineClasses
275 // load_shared_class - while loading a class from shared archive
276 // resolve_instance_class_or_null:
277 // via: handle_parallel_super_load
278 // when resolving a class that has an existing placeholder with
279 // a saved superclass [i.e. a defineClass is currently in progress]
280 // if another thread is trying to resolve the class, it must do
281 // super-class checks on its own thread to catch class circularity
282 // This last call is critical in class circularity checking for cases
283 // where classloading is delegated to different threads and the
284 // classloader lock is released.
285 // Take the case: Base->Super->Base
286 // 1. If thread T1 tries to do a defineClass of class Base
287 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
288 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
289 // so it tries to load Super
290 // 3. If we load the class internally, or user classloader uses same thread
291 // loadClassFromxxx or defineClass via parseClassFile Super ...
292 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
293 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
294 // 3.4 calls resolve_super_or_fail Base
295 // 3.5 finds T1,Base -> throws class circularity
296 //OR 4. If T2 tries to resolve Super via defineClass Super ...
297 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
298 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
299 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
300 // 4.4 finds T2, Super -> throws class circularity
301 // Must be called, even if superclass is null, since this is
302 // where the placeholder entry is created which claims this
303 // thread is loading this class/classloader.
304 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
305 Symbol* class_name,
306 Handle class_loader,
307 Handle protection_domain,
308 bool is_superclass,
309 TRAPS) {
310 // Double-check, if child class is already loaded, just return super-class,interface
311 // Don't add a placedholder if already loaded, i.e. already in system dictionary
312 // Make sure there's a placeholder for the *child* before resolving.
313 // Used as a claim that this thread is currently loading superclass/classloader
314 // Used here for ClassCircularity checks and also for heap verification
315 // (every InstanceKlass in the heap needs to be in the system dictionary
316 // or have a placeholder).
317 // Must check ClassCircularity before checking if super class is already loaded
318 //
319 // We might not already have a placeholder if this child_name was
320 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
321 // the name of the class might not be known until the stream is actually
322 // parsed.
323 // Bugs 4643874, 4715493
324 // compute_hash can have a safepoint
326 ClassLoaderData* loader_data = class_loader_data(class_loader);
327 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
328 int d_index = dictionary()->hash_to_index(d_hash);
329 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
330 int p_index = placeholders()->hash_to_index(p_hash);
331 // can't throw error holding a lock
332 bool child_already_loaded = false;
333 bool throw_circularity_error = false;
334 {
335 MutexLocker mu(SystemDictionary_lock, THREAD);
336 Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
337 Klass* quicksuperk;
338 // to support // loading: if child done loading, just return superclass
339 // if class_name, & class_loader don't match:
340 // if initial define, SD update will give LinkageError
341 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
342 // so we don't throw an exception here.
343 // see: nsk redefclass014 & java.lang.instrument Instrument032
344 if ((childk != NULL ) && (is_superclass) &&
345 ((quicksuperk = InstanceKlass::cast(childk)->super()) != NULL) &&
347 ((quicksuperk->name() == class_name) &&
348 (quicksuperk->class_loader() == class_loader()))) {
349 return quicksuperk;
350 } else {
351 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
352 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
353 throw_circularity_error = true;
354 }
355 }
356 if (!throw_circularity_error) {
357 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
358 }
359 }
360 if (throw_circularity_error) {
361 ResourceMark rm(THREAD);
362 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
363 }
365 // java.lang.Object should have been found above
366 assert(class_name != NULL, "null super class for resolving");
367 // Resolve the super class or interface, check results on return
368 Klass* superk = SystemDictionary::resolve_or_null(class_name,
369 class_loader,
370 protection_domain,
371 THREAD);
373 KlassHandle superk_h(THREAD, superk);
375 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
376 // It is no longer necessary to keep the placeholder table alive until update_dictionary
377 // or error. GC used to walk the placeholder table as strong roots.
378 // The instanceKlass is kept alive because the class loader is on the stack,
379 // which keeps the loader_data alive, as well as all instanceKlasses in
380 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
381 {
382 MutexLocker mu(SystemDictionary_lock, THREAD);
383 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
384 SystemDictionary_lock->notify_all();
385 }
386 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
387 // can null superk
388 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD));
389 }
391 return superk_h();
392 }
394 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
395 Handle class_loader,
396 Handle protection_domain,
397 TRAPS) {
398 if(!has_checkPackageAccess()) return;
400 // Now we have to call back to java to check if the initating class has access
401 JavaValue result(T_VOID);
402 if (TraceProtectionDomainVerification) {
403 // Print out trace information
404 tty->print_cr("Checking package access");
405 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr();
406 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr();
407 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr();
408 }
410 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass());
411 JavaCalls::call_special(&result,
412 class_loader,
413 system_loader,
414 vmSymbols::checkPackageAccess_name(),
415 vmSymbols::class_protectiondomain_signature(),
416 Handle(THREAD, klass->java_mirror()),
417 protection_domain,
418 THREAD);
420 if (TraceProtectionDomainVerification) {
421 if (HAS_PENDING_EXCEPTION) {
422 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!");
423 } else {
424 tty->print_cr(" -> granted");
425 }
426 tty->cr();
427 }
429 if (HAS_PENDING_EXCEPTION) return;
431 // If no exception has been thrown, we have validated the protection domain
432 // Insert the protection domain of the initiating class into the set.
433 {
434 // We recalculate the entry here -- we've called out to java since
435 // the last time it was calculated.
436 ClassLoaderData* loader_data = class_loader_data(class_loader);
438 Symbol* kn = klass->name();
439 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
440 int d_index = dictionary()->hash_to_index(d_hash);
442 MutexLocker mu(SystemDictionary_lock, THREAD);
443 {
444 // Note that we have an entry, and entries can be deleted only during GC,
445 // so we cannot allow GC to occur while we're holding this entry.
447 // We're using a No_Safepoint_Verifier to catch any place where we
448 // might potentially do a GC at all.
449 // Dictionary::do_unloading() asserts that classes in SD are only
450 // unloaded at a safepoint. Anonymous classes are not in SD.
451 No_Safepoint_Verifier nosafepoint;
452 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
453 protection_domain, THREAD);
454 }
455 }
456 }
458 // We only get here if this thread finds that another thread
459 // has already claimed the placeholder token for the current operation,
460 // but that other thread either never owned or gave up the
461 // object lock
462 // Waits on SystemDictionary_lock to indicate placeholder table updated
463 // On return, caller must recheck placeholder table state
464 //
465 // We only get here if
466 // 1) custom classLoader, i.e. not bootstrap classloader
467 // 2) UnsyncloadClass not set
468 // 3) custom classLoader has broken the class loader objectLock
469 // so another thread got here in parallel
470 //
471 // lockObject must be held.
472 // Complicated dance due to lock ordering:
473 // Must first release the classloader object lock to
474 // allow initial definer to complete the class definition
475 // and to avoid deadlock
476 // Reclaim classloader lock object with same original recursion count
477 // Must release SystemDictionary_lock after notify, since
478 // class loader lock must be claimed before SystemDictionary_lock
479 // to prevent deadlocks
480 //
481 // The notify allows applications that did an untimed wait() on
482 // the classloader object lock to not hang.
483 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
484 assert_lock_strong(SystemDictionary_lock);
486 bool calledholdinglock
487 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
488 assert(calledholdinglock,"must hold lock for notify");
489 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
490 ObjectSynchronizer::notifyall(lockObject, THREAD);
491 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
492 SystemDictionary_lock->wait();
493 SystemDictionary_lock->unlock();
494 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
495 SystemDictionary_lock->lock();
496 }
498 // If the class in is in the placeholder table, class loading is in progress
499 // For cases where the application changes threads to load classes, it
500 // is critical to ClassCircularity detection that we try loading
501 // the superclass on the same thread internally, so we do parallel
502 // super class loading here.
503 // This also is critical in cases where the original thread gets stalled
504 // even in non-circularity situations.
505 // Note: must call resolve_super_or_fail even if null super -
506 // to force placeholder entry creation for this class for circularity detection
507 // Caller must check for pending exception
508 // Returns non-null Klass* if other thread has completed load
509 // and we are done,
510 // If return null Klass* and no pending exception, the caller must load the class
511 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
512 Symbol* name, Symbol* superclassname, Handle class_loader,
513 Handle protection_domain, Handle lockObject, TRAPS) {
515 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
516 ClassLoaderData* loader_data = class_loader_data(class_loader);
517 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
518 int d_index = dictionary()->hash_to_index(d_hash);
519 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
520 int p_index = placeholders()->hash_to_index(p_hash);
522 // superk is not used, resolve_super called for circularity check only
523 // This code is reached in two situations. One if this thread
524 // is loading the same class twice (e.g. ClassCircularity, or
525 // java.lang.instrument).
526 // The second is if another thread started the resolve_super first
527 // and has not yet finished.
528 // In both cases the original caller will clean up the placeholder
529 // entry on error.
530 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
531 superclassname,
532 class_loader,
533 protection_domain,
534 true,
535 CHECK_(nh));
537 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
538 // Serial class loaders and bootstrap classloader do wait for superclass loads
539 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
540 MutexLocker mu(SystemDictionary_lock, THREAD);
541 // Check if classloading completed while we were loading superclass or waiting
542 Klass* check = find_class(d_index, d_hash, name, loader_data);
543 if (check != NULL) {
544 // Klass is already loaded, so just return it
545 return(instanceKlassHandle(THREAD, check));
546 } else {
547 return nh;
548 }
549 }
551 // must loop to both handle other placeholder updates
552 // and spurious notifications
553 bool super_load_in_progress = true;
554 PlaceholderEntry* placeholder;
555 while (super_load_in_progress) {
556 MutexLocker mu(SystemDictionary_lock, THREAD);
557 // Check if classloading completed while we were loading superclass or waiting
558 Klass* check = find_class(d_index, d_hash, name, loader_data);
559 if (check != NULL) {
560 // Klass is already loaded, so just return it
561 return(instanceKlassHandle(THREAD, check));
562 } else {
563 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
564 if (placeholder && placeholder->super_load_in_progress() ){
565 // Before UnsyncloadClass:
566 // We only get here if the application has released the
567 // classloader lock when another thread was in the middle of loading a
568 // superclass/superinterface for this class, and now
569 // this thread is also trying to load this class.
570 // To minimize surprises, the first thread that started to
571 // load a class should be the one to complete the loading
572 // with the classfile it initially expected.
573 // This logic has the current thread wait once it has done
574 // all the superclass/superinterface loading it can, until
575 // the original thread completes the class loading or fails
576 // If it completes we will use the resulting InstanceKlass
577 // which we will find below in the systemDictionary.
578 // We also get here for parallel bootstrap classloader
579 if (class_loader.is_null()) {
580 SystemDictionary_lock->wait();
581 } else {
582 double_lock_wait(lockObject, THREAD);
583 }
584 } else {
585 // If not in SD and not in PH, other thread's load must have failed
586 super_load_in_progress = false;
587 }
588 }
589 }
590 return (nh);
591 }
594 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
595 Handle class_loader,
596 Handle protection_domain,
597 TRAPS) {
598 assert(name != NULL && !FieldType::is_array(name) &&
599 !FieldType::is_obj(name), "invalid class name");
601 Ticks class_load_start_time = Ticks::now();
603 // UseNewReflection
604 // Fix for 4474172; see evaluation for more details
605 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
606 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
608 // Do lookup to see if class already exist and the protection domain
609 // has the right access
610 // This call uses find which checks protection domain already matches
611 // All subsequent calls use find_class, and set has_loaded_class so that
612 // before we return a result we call out to java to check for valid protection domain
613 // to allow returning the Klass* and add it to the pd_set if it is valid
614 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
615 int d_index = dictionary()->hash_to_index(d_hash);
616 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
617 protection_domain, THREAD);
618 if (probe != NULL) return probe;
621 // Non-bootstrap class loaders will call out to class loader and
622 // define via jvm/jni_DefineClass which will acquire the
623 // class loader object lock to protect against multiple threads
624 // defining the class in parallel by accident.
625 // This lock must be acquired here so the waiter will find
626 // any successful result in the SystemDictionary and not attempt
627 // the define
628 // ParallelCapable Classloaders and the bootstrap classloader,
629 // or all classloaders with UnsyncloadClass do not acquire lock here
630 bool DoObjectLock = true;
631 if (is_parallelCapable(class_loader)) {
632 DoObjectLock = false;
633 }
635 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
636 int p_index = placeholders()->hash_to_index(p_hash);
638 // Class is not in SystemDictionary so we have to do loading.
639 // Make sure we are synchronized on the class loader before we proceed
640 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
641 check_loader_lock_contention(lockObject, THREAD);
642 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
644 // Check again (after locking) if class already exist in SystemDictionary
645 bool class_has_been_loaded = false;
646 bool super_load_in_progress = false;
647 bool havesupername = false;
648 instanceKlassHandle k;
649 PlaceholderEntry* placeholder;
650 Symbol* superclassname = NULL;
652 {
653 MutexLocker mu(SystemDictionary_lock, THREAD);
654 Klass* check = find_class(d_index, d_hash, name, loader_data);
655 if (check != NULL) {
656 // Klass is already loaded, so just return it
657 class_has_been_loaded = true;
658 k = instanceKlassHandle(THREAD, check);
659 } else {
660 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
661 if (placeholder && placeholder->super_load_in_progress()) {
662 super_load_in_progress = true;
663 if (placeholder->havesupername() == true) {
664 superclassname = placeholder->supername();
665 havesupername = true;
666 }
667 }
668 }
669 }
671 // If the class is in the placeholder table, class loading is in progress
672 if (super_load_in_progress && havesupername==true) {
673 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
674 class_loader, protection_domain, lockObject, THREAD);
675 if (HAS_PENDING_EXCEPTION) {
676 return NULL;
677 }
678 if (!k.is_null()) {
679 class_has_been_loaded = true;
680 }
681 }
683 bool throw_circularity_error = false;
684 if (!class_has_been_loaded) {
685 bool load_instance_added = false;
687 // add placeholder entry to record loading instance class
688 // Five cases:
689 // All cases need to prevent modifying bootclasssearchpath
690 // in parallel with a classload of same classname
691 // Redefineclasses uses existence of the placeholder for the duration
692 // of the class load to prevent concurrent redefinition of not completely
693 // defined classes.
694 // case 1. traditional classloaders that rely on the classloader object lock
695 // - no other need for LOAD_INSTANCE
696 // case 2. traditional classloaders that break the classloader object lock
697 // as a deadlock workaround. Detection of this case requires that
698 // this check is done while holding the classloader object lock,
699 // and that lock is still held when calling classloader's loadClass.
700 // For these classloaders, we ensure that the first requestor
701 // completes the load and other requestors wait for completion.
702 // case 3. UnsyncloadClass - don't use objectLocker
703 // With this flag, we allow parallel classloading of a
704 // class/classloader pair
705 // case4. Bootstrap classloader - don't own objectLocker
706 // This classloader supports parallelism at the classloader level,
707 // but only allows a single load of a class/classloader pair.
708 // No performance benefit and no deadlock issues.
709 // case 5. parallelCapable user level classloaders - without objectLocker
710 // Allow parallel classloading of a class/classloader pair
712 {
713 MutexLocker mu(SystemDictionary_lock, THREAD);
714 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
715 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
716 if (oldprobe) {
717 // only need check_seen_thread once, not on each loop
718 // 6341374 java/lang/Instrument with -Xcomp
719 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
720 throw_circularity_error = true;
721 } else {
722 // case 1: traditional: should never see load_in_progress.
723 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
725 // case 4: bootstrap classloader: prevent futile classloading,
726 // wait on first requestor
727 if (class_loader.is_null()) {
728 SystemDictionary_lock->wait();
729 } else {
730 // case 2: traditional with broken classloader lock. wait on first
731 // requestor.
732 double_lock_wait(lockObject, THREAD);
733 }
734 // Check if classloading completed while we were waiting
735 Klass* check = find_class(d_index, d_hash, name, loader_data);
736 if (check != NULL) {
737 // Klass is already loaded, so just return it
738 k = instanceKlassHandle(THREAD, check);
739 class_has_been_loaded = true;
740 }
741 // check if other thread failed to load and cleaned up
742 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
743 }
744 }
745 }
746 }
747 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
748 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
749 // LOAD_INSTANCE in parallel
751 if (!throw_circularity_error && !class_has_been_loaded) {
752 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
753 load_instance_added = true;
754 // For class loaders that do not acquire the classloader object lock,
755 // if they did not catch another thread holding LOAD_INSTANCE,
756 // need a check analogous to the acquire ObjectLocker/find_class
757 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
758 // one final check if the load has already completed
759 // class loaders holding the ObjectLock shouldn't find the class here
760 Klass* check = find_class(d_index, d_hash, name, loader_data);
761 if (check != NULL) {
762 // Klass is already loaded, so return it after checking/adding protection domain
763 k = instanceKlassHandle(THREAD, check);
764 class_has_been_loaded = true;
765 }
766 }
767 }
769 // must throw error outside of owning lock
770 if (throw_circularity_error) {
771 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
772 ResourceMark rm(THREAD);
773 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
774 }
776 if (!class_has_been_loaded) {
778 // Do actual loading
779 k = load_instance_class(name, class_loader, THREAD);
781 // For UnsyncloadClass only
782 // If they got a linkageError, check if a parallel class load succeeded.
783 // If it did, then for bytecode resolution the specification requires
784 // that we return the same result we did for the other thread, i.e. the
785 // successfully loaded InstanceKlass
786 // Should not get here for classloaders that support parallelism
787 // with the new cleaner mechanism, even with AllowParallelDefineClass
788 // Bootstrap goes through here to allow for an extra guarantee check
789 if (UnsyncloadClass || (class_loader.is_null())) {
790 if (k.is_null() && HAS_PENDING_EXCEPTION
791 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
792 MutexLocker mu(SystemDictionary_lock, THREAD);
793 Klass* check = find_class(d_index, d_hash, name, loader_data);
794 if (check != NULL) {
795 // Klass is already loaded, so just use it
796 k = instanceKlassHandle(THREAD, check);
797 CLEAR_PENDING_EXCEPTION;
798 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
799 }
800 }
801 }
803 // If everything was OK (no exceptions, no null return value), and
804 // class_loader is NOT the defining loader, do a little more bookkeeping.
805 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
806 k->class_loader() != class_loader()) {
808 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
810 // Need to check for a PENDING_EXCEPTION again; check_constraints
811 // can throw and doesn't use the CHECK macro.
812 if (!HAS_PENDING_EXCEPTION) {
813 { // Grabbing the Compile_lock prevents systemDictionary updates
814 // during compilations.
815 MutexLocker mu(Compile_lock, THREAD);
816 update_dictionary(d_index, d_hash, p_index, p_hash,
817 k, class_loader, THREAD);
818 }
820 if (JvmtiExport::should_post_class_load()) {
821 Thread *thread = THREAD;
822 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
823 JvmtiExport::post_class_load((JavaThread *) thread, k());
824 }
825 }
826 }
827 } // load_instance_class loop
829 if (HAS_PENDING_EXCEPTION) {
830 // An exception, such as OOM could have happened at various places inside
831 // load_instance_class. We might have partially initialized a shared class
832 // and need to clean it up.
833 if (class_loader.is_null()) {
834 // In some cases k may be null. Let's find the shared class again.
835 instanceKlassHandle ik(THREAD, find_shared_class(name));
836 if (ik.not_null()) {
837 if (ik->class_loader_data() == NULL) {
838 // We didn't go as far as Klass::restore_unshareable_info(),
839 // so nothing to clean up.
840 } else {
841 Klass *kk;
842 {
843 MutexLocker mu(SystemDictionary_lock, THREAD);
844 kk = find_class(d_index, d_hash, name, ik->class_loader_data());
845 }
846 if (kk != NULL) {
847 // No clean up is needed if the shared class has been entered
848 // into system dictionary, as load_shared_class() won't be called
849 // again.
850 } else {
851 // This must be done outside of the SystemDictionary_lock to
852 // avoid deadlock.
853 //
854 // Note that Klass::restore_unshareable_info (called via
855 // load_instance_class above) is also called outside
856 // of SystemDictionary_lock. Other threads are blocked from
857 // loading this class because they are waiting on the
858 // SystemDictionary_lock until this thread removes
859 // the placeholder below.
860 //
861 // This need to be re-thought when parallel-capable non-boot
862 // classloaders are supported by CDS (today they're not).
863 clean_up_shared_class(ik, class_loader, THREAD);
864 }
865 }
866 }
867 }
868 }
870 if (load_instance_added == true) {
871 // clean up placeholder entries for LOAD_INSTANCE success or error
872 // This brackets the SystemDictionary updates for both defining
873 // and initiating loaders
874 MutexLocker mu(SystemDictionary_lock, THREAD);
875 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
876 SystemDictionary_lock->notify_all();
877 }
878 }
880 if (HAS_PENDING_EXCEPTION || k.is_null()) {
881 return NULL;
882 }
884 post_class_load_event(class_load_start_time, k, class_loader);
886 #ifdef ASSERT
887 {
888 ClassLoaderData* loader_data = k->class_loader_data();
889 MutexLocker mu(SystemDictionary_lock, THREAD);
890 Klass* kk = find_class(name, loader_data);
891 assert(kk == k(), "should be present in dictionary");
892 }
893 #endif
895 // return if the protection domain in NULL
896 if (protection_domain() == NULL) return k();
898 // Check the protection domain has the right access
899 {
900 MutexLocker mu(SystemDictionary_lock, THREAD);
901 // Note that we have an entry, and entries can be deleted only during GC,
902 // so we cannot allow GC to occur while we're holding this entry.
903 // We're using a No_Safepoint_Verifier to catch any place where we
904 // might potentially do a GC at all.
905 // Dictionary::do_unloading() asserts that classes in SD are only
906 // unloaded at a safepoint. Anonymous classes are not in SD.
907 No_Safepoint_Verifier nosafepoint;
908 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
909 loader_data,
910 protection_domain)) {
911 return k();
912 }
913 }
915 // Verify protection domain. If it fails an exception is thrown
916 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
918 return k();
919 }
922 // This routine does not lock the system dictionary.
923 //
924 // Since readers don't hold a lock, we must make sure that system
925 // dictionary entries are only removed at a safepoint (when only one
926 // thread is running), and are added to in a safe way (all links must
927 // be updated in an MT-safe manner).
928 //
929 // Callers should be aware that an entry could be added just after
930 // _dictionary->bucket(index) is read here, so the caller will not see
931 // the new entry.
933 Klass* SystemDictionary::find(Symbol* class_name,
934 Handle class_loader,
935 Handle protection_domain,
936 TRAPS) {
938 // UseNewReflection
939 // The result of this call should be consistent with the result
940 // of the call to resolve_instance_class_or_null().
941 // See evaluation 6790209 and 4474172 for more details.
942 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
943 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
945 if (loader_data == NULL) {
946 // If the ClassLoaderData has not been setup,
947 // then the class loader has no entries in the dictionary.
948 return NULL;
949 }
951 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
952 int d_index = dictionary()->hash_to_index(d_hash);
954 {
955 // Note that we have an entry, and entries can be deleted only during GC,
956 // so we cannot allow GC to occur while we're holding this entry.
957 // We're using a No_Safepoint_Verifier to catch any place where we
958 // might potentially do a GC at all.
959 // Dictionary::do_unloading() asserts that classes in SD are only
960 // unloaded at a safepoint. Anonymous classes are not in SD.
961 No_Safepoint_Verifier nosafepoint;
962 return dictionary()->find(d_index, d_hash, class_name, loader_data,
963 protection_domain, THREAD);
964 }
965 }
968 // Look for a loaded instance or array klass by name. Do not do any loading.
969 // return NULL in case of error.
970 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
971 Handle class_loader,
972 Handle protection_domain,
973 TRAPS) {
974 Klass* k = NULL;
975 assert(class_name != NULL, "class name must be non NULL");
977 if (FieldType::is_array(class_name)) {
978 // The name refers to an array. Parse the name.
979 // dimension and object_key in FieldArrayInfo are assigned as a
980 // side-effect of this call
981 FieldArrayInfo fd;
982 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
983 if (t != T_OBJECT) {
984 k = Universe::typeArrayKlassObj(t);
985 } else {
986 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
987 }
988 if (k != NULL) {
989 k = k->array_klass_or_null(fd.dimension());
990 }
991 } else {
992 k = find(class_name, class_loader, protection_domain, THREAD);
993 }
994 return k;
995 }
997 // Note: this method is much like resolve_from_stream, but
998 // updates no supplemental data structures.
999 // TODO consolidate the two methods with a helper routine?
1000 Klass* SystemDictionary::parse_stream(Symbol* class_name,
1001 Handle class_loader,
1002 Handle protection_domain,
1003 ClassFileStream* st,
1004 KlassHandle host_klass,
1005 GrowableArray<Handle>* cp_patches,
1006 TRAPS) {
1007 TempNewSymbol parsed_name = NULL;
1009 Ticks class_load_start_time = Ticks::now();
1011 ClassLoaderData* loader_data;
1012 if (host_klass.not_null()) {
1013 // Create a new CLD for anonymous class, that uses the same class loader
1014 // as the host_klass
1015 assert(EnableInvokeDynamic, "");
1016 guarantee(host_klass->class_loader() == class_loader(), "should be the same");
1017 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
1018 loader_data->record_dependency(host_klass(), CHECK_NULL);
1019 } else {
1020 loader_data = ClassLoaderData::class_loader_data(class_loader());
1021 }
1023 // Parse the stream. Note that we do this even though this klass might
1024 // already be present in the SystemDictionary, otherwise we would not
1025 // throw potential ClassFormatErrors.
1026 //
1027 // Note: "name" is updated.
1029 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
1030 loader_data,
1031 protection_domain,
1032 host_klass,
1033 cp_patches,
1034 parsed_name,
1035 true,
1036 THREAD);
1039 if (host_klass.not_null() && k.not_null()) {
1040 assert(EnableInvokeDynamic, "");
1041 k->set_host_klass(host_klass());
1042 // If it's anonymous, initialize it now, since nobody else will.
1044 {
1045 MutexLocker mu_r(Compile_lock, THREAD);
1047 // Add to class hierarchy, initialize vtables, and do possible
1048 // deoptimizations.
1049 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1051 // But, do not add to system dictionary.
1053 // compiled code dependencies need to be validated anyway
1054 notice_modification();
1055 }
1057 // Rewrite and patch constant pool here.
1058 k->link_class(CHECK_NULL);
1059 if (cp_patches != NULL) {
1060 k->constants()->patch_resolved_references(cp_patches);
1061 }
1062 k->eager_initialize(CHECK_NULL);
1064 // notify jvmti
1065 if (JvmtiExport::should_post_class_load()) {
1066 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1067 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1068 }
1070 post_class_load_event(class_load_start_time, k, class_loader);
1071 }
1072 assert(host_klass.not_null() || cp_patches == NULL,
1073 "cp_patches only found with host_klass");
1075 return k();
1076 }
1078 // Add a klass to the system from a stream (called by jni_DefineClass and
1079 // JVM_DefineClass).
1080 // Note: class_name can be NULL. In that case we do not know the name of
1081 // the class until we have parsed the stream.
1083 Klass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1084 Handle class_loader,
1085 Handle protection_domain,
1086 ClassFileStream* st,
1087 bool verify,
1088 TRAPS) {
1090 // Classloaders that support parallelism, e.g. bootstrap classloader,
1091 // or all classloaders with UnsyncloadClass do not acquire lock here
1092 bool DoObjectLock = true;
1093 if (is_parallelCapable(class_loader)) {
1094 DoObjectLock = false;
1095 }
1097 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
1099 // Make sure we are synchronized on the class loader before we proceed
1100 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1101 check_loader_lock_contention(lockObject, THREAD);
1102 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1104 TempNewSymbol parsed_name = NULL;
1106 // Parse the stream. Note that we do this even though this klass might
1107 // already be present in the SystemDictionary, otherwise we would not
1108 // throw potential ClassFormatErrors.
1109 //
1110 // Note: "name" is updated.
1112 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
1113 loader_data,
1114 protection_domain,
1115 parsed_name,
1116 verify,
1117 THREAD);
1119 const char* pkg = "java/";
1120 if (!HAS_PENDING_EXCEPTION &&
1121 !class_loader.is_null() &&
1122 parsed_name != NULL &&
1123 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
1124 // It is illegal to define classes in the "java." package from
1125 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
1126 ResourceMark rm(THREAD);
1127 char* name = parsed_name->as_C_string();
1128 char* index = strrchr(name, '/');
1129 *index = '\0'; // chop to just the package name
1130 while ((index = strchr(name, '/')) != NULL) {
1131 *index = '.'; // replace '/' with '.' in package name
1132 }
1133 const char* fmt = "Prohibited package name: %s";
1134 size_t len = strlen(fmt) + strlen(name);
1135 char* message = NEW_RESOURCE_ARRAY(char, len);
1136 jio_snprintf(message, len, fmt, name);
1137 Exceptions::_throw_msg(THREAD_AND_LOCATION,
1138 vmSymbols::java_lang_SecurityException(), message);
1139 }
1141 if (!HAS_PENDING_EXCEPTION) {
1142 assert(parsed_name != NULL, "Sanity");
1143 assert(class_name == NULL || class_name == parsed_name, "name mismatch");
1144 // Verification prevents us from creating names with dots in them, this
1145 // asserts that that's the case.
1146 assert(is_internal_format(parsed_name),
1147 "external class name format used internally");
1149 // Add class just loaded
1150 // If a class loader supports parallel classloading handle parallel define requests
1151 // find_or_define_instance_class may return a different InstanceKlass
1152 if (is_parallelCapable(class_loader)) {
1153 k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
1154 } else {
1155 define_instance_class(k, THREAD);
1156 }
1157 }
1159 // Make sure we have an entry in the SystemDictionary on success
1160 debug_only( {
1161 if (!HAS_PENDING_EXCEPTION) {
1162 assert(parsed_name != NULL, "parsed_name is still null?");
1163 Symbol* h_name = k->name();
1164 ClassLoaderData *defining_loader_data = k->class_loader_data();
1166 MutexLocker mu(SystemDictionary_lock, THREAD);
1168 Klass* check = find_class(parsed_name, loader_data);
1169 assert(check == k(), "should be present in the dictionary");
1171 Klass* check2 = find_class(h_name, defining_loader_data);
1172 assert(check == check2, "name inconsistancy in SystemDictionary");
1173 }
1174 } );
1176 return k();
1177 }
1180 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
1181 int number_of_entries) {
1182 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
1183 "bad shared dictionary size.");
1184 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1185 }
1188 // If there is a shared dictionary, then find the entry for the
1189 // given shared system class, if any.
1191 Klass* SystemDictionary::find_shared_class(Symbol* class_name) {
1192 if (shared_dictionary() != NULL) {
1193 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
1194 int d_index = shared_dictionary()->hash_to_index(d_hash);
1196 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1197 } else {
1198 return NULL;
1199 }
1200 }
1203 // Load a class from the shared spaces (found through the shared system
1204 // dictionary). Force the superclass and all interfaces to be loaded.
1205 // Update the class definition to include sibling classes and no
1206 // subclasses (yet). [Classes in the shared space are not part of the
1207 // object hierarchy until loaded.]
1209 instanceKlassHandle SystemDictionary::load_shared_class(
1210 Symbol* class_name, Handle class_loader, TRAPS) {
1211 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
1212 return load_shared_class(ik, class_loader, THREAD);
1213 }
1215 instanceKlassHandle SystemDictionary::load_shared_class(
1216 instanceKlassHandle ik, Handle class_loader, TRAPS) {
1217 assert(class_loader.is_null(), "non-null classloader for shared class?");
1218 if (ik.not_null()) {
1219 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1220 Symbol* class_name = ik->name();
1222 // Found the class, now load the superclass and interfaces. If they
1223 // are shared, add them to the main system dictionary and reset
1224 // their hierarchy references (supers, subs, and interfaces).
1226 if (ik->super() != NULL) {
1227 Symbol* cn = ik->super()->name();
1228 resolve_super_or_fail(class_name, cn,
1229 class_loader, Handle(), true, CHECK_(nh));
1230 }
1232 Array<Klass*>* interfaces = ik->local_interfaces();
1233 int num_interfaces = interfaces->length();
1234 for (int index = 0; index < num_interfaces; index++) {
1235 Klass* k = interfaces->at(index);
1237 // Note: can not use InstanceKlass::cast here because
1238 // interfaces' InstanceKlass's C++ vtbls haven't been
1239 // reinitialized yet (they will be once the interface classes
1240 // are loaded)
1241 Symbol* name = k->name();
1242 resolve_super_or_fail(class_name, name, class_loader, Handle(), false, CHECK_(nh));
1243 }
1245 // Adjust methods to recover missing data. They need addresses for
1246 // interpreter entry points and their default native method address
1247 // must be reset.
1249 // Updating methods must be done under a lock so multiple
1250 // threads don't update these in parallel
1251 // Shared classes are all currently loaded by the bootstrap
1252 // classloader, so this will never cause a deadlock on
1253 // a custom class loader lock.
1255 {
1256 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1257 check_loader_lock_contention(lockObject, THREAD);
1258 ObjectLocker ol(lockObject, THREAD, true);
1259 ik->restore_unshareable_info(CHECK_(nh));
1260 }
1262 if (TraceClassLoading) {
1263 ResourceMark rm;
1264 tty->print("[Loaded %s", ik->external_name());
1265 tty->print(" from shared objects file");
1266 tty->print_cr("]");
1267 }
1268 // notify a class loaded from shared object
1269 ClassLoadingService::notify_class_loaded(InstanceKlass::cast(ik()),
1270 true /* shared class */);
1271 }
1272 return ik;
1273 }
1275 void SystemDictionary::clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS) {
1276 // Updating methods must be done under a lock so multiple
1277 // threads don't update these in parallel
1278 // Shared classes are all currently loaded by the bootstrap
1279 // classloader, so this will never cause a deadlock on
1280 // a custom class loader lock.
1281 {
1282 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1283 check_loader_lock_contention(lockObject, THREAD);
1284 ObjectLocker ol(lockObject, THREAD, true);
1285 ik->remove_unshareable_info();
1286 }
1287 }
1289 instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1290 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1291 if (class_loader.is_null()) {
1293 // Search the shared system dictionary for classes preloaded into the
1294 // shared spaces.
1295 instanceKlassHandle k;
1296 {
1297 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1298 k = load_shared_class(class_name, class_loader, THREAD);
1299 }
1301 if (k.is_null()) {
1302 // Use VM class loader
1303 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1304 k = ClassLoader::load_classfile(class_name, CHECK_(nh));
1305 }
1307 // find_or_define_instance_class may return a different InstanceKlass
1308 if (!k.is_null()) {
1309 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
1310 }
1311 return k;
1312 } else {
1313 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1314 ResourceMark rm(THREAD);
1316 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1317 JavaThread* jt = (JavaThread*) THREAD;
1319 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1320 ClassLoader::perf_app_classload_selftime(),
1321 ClassLoader::perf_app_classload_count(),
1322 jt->get_thread_stat()->perf_recursion_counts_addr(),
1323 jt->get_thread_stat()->perf_timers_addr(),
1324 PerfClassTraceTime::CLASS_LOAD);
1326 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
1327 // Translate to external class name format, i.e., convert '/' chars to '.'
1328 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
1330 JavaValue result(T_OBJECT);
1332 KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass());
1334 // Call public unsynchronized loadClass(String) directly for all class loaders
1335 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
1336 // acquire a class-name based lock rather than the class loader object lock.
1337 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
1338 // so the call to loadClassInternal() was not required.
1339 //
1340 // UnsyncloadClass flag means both call loadClass(String) and do
1341 // not acquire the class loader lock even for class loaders that are
1342 // not parallelCapable. This was a risky transitional
1343 // flag for diagnostic purposes only. It is risky to call
1344 // custom class loaders without synchronization.
1345 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1346 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
1347 // Do NOT assume this will be supported in future releases.
1348 //
1349 // Added MustCallLoadClassInternal in case we discover in the field
1350 // a customer that counts on this call
1351 if (MustCallLoadClassInternal && has_loadClassInternal()) {
1352 JavaCalls::call_special(&result,
1353 class_loader,
1354 spec_klass,
1355 vmSymbols::loadClassInternal_name(),
1356 vmSymbols::string_class_signature(),
1357 string,
1358 CHECK_(nh));
1359 } else {
1360 JavaCalls::call_virtual(&result,
1361 class_loader,
1362 spec_klass,
1363 vmSymbols::loadClass_name(),
1364 vmSymbols::string_class_signature(),
1365 string,
1366 CHECK_(nh));
1367 }
1369 assert(result.get_type() == T_OBJECT, "just checking");
1370 oop obj = (oop) result.get_jobject();
1372 // Primitive classes return null since forName() can not be
1373 // used to obtain any of the Class objects representing primitives or void
1374 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1375 instanceKlassHandle k =
1376 instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj));
1377 // For user defined Java class loaders, check that the name returned is
1378 // the same as that requested. This check is done for the bootstrap
1379 // loader when parsing the class file.
1380 if (class_name == k->name()) {
1381 return k;
1382 }
1383 }
1384 // Class is not found or has the wrong name, return NULL
1385 return nh;
1386 }
1387 }
1389 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
1391 ClassLoaderData* loader_data = k->class_loader_data();
1392 Handle class_loader_h(THREAD, loader_data->class_loader());
1394 for (uintx it = 0; it < GCExpandToAllocateDelayMillis; it++){}
1396 // for bootstrap and other parallel classloaders don't acquire lock,
1397 // use placeholder token
1398 // If a parallelCapable class loader calls define_instance_class instead of
1399 // find_or_define_instance_class to get here, we have a timing
1400 // hole with systemDictionary updates and check_constraints
1401 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1402 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1403 compute_loader_lock_object(class_loader_h, THREAD)),
1404 "define called without lock");
1405 }
1407 // Check class-loading constraints. Throw exception if violation is detected.
1408 // Grabs and releases SystemDictionary_lock
1409 // The check_constraints/find_class call and update_dictionary sequence
1410 // must be "atomic" for a specific class/classloader pair so we never
1411 // define two different instanceKlasses for that class/classloader pair.
1412 // Existing classloaders will call define_instance_class with the
1413 // classloader lock held
1414 // Parallel classloaders will call find_or_define_instance_class
1415 // which will require a token to perform the define class
1416 Symbol* name_h = k->name();
1417 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1418 int d_index = dictionary()->hash_to_index(d_hash);
1419 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1421 // Register class just loaded with class loader (placed in Vector)
1422 // Note we do this before updating the dictionary, as this can
1423 // fail with an OutOfMemoryError (if it does, we will *not* put this
1424 // class in the dictionary and will not update the class hierarchy).
1425 // JVMTI FollowReferences needs to find the classes this way.
1426 if (k->class_loader() != NULL) {
1427 methodHandle m(THREAD, Universe::loader_addClass_method());
1428 JavaValue result(T_VOID);
1429 JavaCallArguments args(class_loader_h);
1430 args.push_oop(Handle(THREAD, k->java_mirror()));
1431 JavaCalls::call(&result, m, &args, CHECK);
1432 }
1434 // Add the new class. We need recompile lock during update of CHA.
1435 {
1436 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1437 int p_index = placeholders()->hash_to_index(p_hash);
1439 MutexLocker mu_r(Compile_lock, THREAD);
1441 // Add to class hierarchy, initialize vtables, and do possible
1442 // deoptimizations.
1443 add_to_hierarchy(k, CHECK); // No exception, but can block
1445 // Add to systemDictionary - so other classes can see it.
1446 // Grabs and releases SystemDictionary_lock
1447 update_dictionary(d_index, d_hash, p_index, p_hash,
1448 k, class_loader_h, THREAD);
1449 }
1450 k->eager_initialize(THREAD);
1452 // notify jvmti
1453 if (JvmtiExport::should_post_class_load()) {
1454 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1455 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1457 }
1459 }
1461 // Support parallel classloading
1462 // All parallel class loaders, including bootstrap classloader
1463 // lock a placeholder entry for this class/class_loader pair
1464 // to allow parallel defines of different classes for this class loader
1465 // With AllowParallelDefine flag==true, in case they do not synchronize around
1466 // FindLoadedClass/DefineClass, calls, we check for parallel
1467 // loading for them, wait if a defineClass is in progress
1468 // and return the initial requestor's results
1469 // This flag does not apply to the bootstrap classloader.
1470 // With AllowParallelDefine flag==false, call through to define_instance_class
1471 // which will throw LinkageError: duplicate class definition.
1472 // False is the requested default.
1473 // For better performance, the class loaders should synchronize
1474 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1475 // potentially waste time reading and parsing the bytestream.
1476 // Note: VM callers should ensure consistency of k/class_name,class_loader
1477 instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
1479 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1480 Symbol* name_h = k->name(); // passed in class_name may be null
1481 ClassLoaderData* loader_data = class_loader_data(class_loader);
1483 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1484 int d_index = dictionary()->hash_to_index(d_hash);
1486 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1487 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1488 int p_index = placeholders()->hash_to_index(p_hash);
1489 PlaceholderEntry* probe;
1491 {
1492 MutexLocker mu(SystemDictionary_lock, THREAD);
1493 // First check if class already defined
1494 if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
1495 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1496 if (check != NULL) {
1497 return(instanceKlassHandle(THREAD, check));
1498 }
1499 }
1501 // Acquire define token for this class/classloader
1502 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1503 // Wait if another thread defining in parallel
1504 // All threads wait - even those that will throw duplicate class: otherwise
1505 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1506 // if other thread has not finished updating dictionary
1507 while (probe->definer() != NULL) {
1508 SystemDictionary_lock->wait();
1509 }
1510 // Only special cases allow parallel defines and can use other thread's results
1511 // Other cases fall through, and may run into duplicate defines
1512 // caught by finding an entry in the SystemDictionary
1513 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
1514 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1515 SystemDictionary_lock->notify_all();
1516 #ifdef ASSERT
1517 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1518 assert(check != NULL, "definer missed recording success");
1519 #endif
1520 return(instanceKlassHandle(THREAD, probe->instance_klass()));
1521 } else {
1522 // This thread will define the class (even if earlier thread tried and had an error)
1523 probe->set_definer(THREAD);
1524 }
1525 }
1527 define_instance_class(k, THREAD);
1529 Handle linkage_exception = Handle(); // null handle
1531 // definer must notify any waiting threads
1532 {
1533 MutexLocker mu(SystemDictionary_lock, THREAD);
1534 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1535 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1536 if (probe != NULL) {
1537 if (HAS_PENDING_EXCEPTION) {
1538 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1539 CLEAR_PENDING_EXCEPTION;
1540 } else {
1541 probe->set_instance_klass(k());
1542 }
1543 probe->set_definer(NULL);
1544 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1545 SystemDictionary_lock->notify_all();
1546 }
1547 }
1549 // Can't throw exception while holding lock due to rank ordering
1550 if (linkage_exception() != NULL) {
1551 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
1552 }
1554 return k;
1555 }
1556 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1557 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1558 if (class_loader.is_null()) {
1559 return Handle(THREAD, _system_loader_lock_obj);
1560 } else {
1561 return class_loader;
1562 }
1563 }
1565 // This method is added to check how often we have to wait to grab loader
1566 // lock. The results are being recorded in the performance counters defined in
1567 // ClassLoader::_sync_systemLoaderLockContentionRate and
1568 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1569 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1570 if (!UsePerfData) {
1571 return;
1572 }
1574 assert(!loader_lock.is_null(), "NULL lock object");
1576 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1577 == ObjectSynchronizer::owner_other) {
1578 // contention will likely happen, so increment the corresponding
1579 // contention counter.
1580 if (loader_lock() == _system_loader_lock_obj) {
1581 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1582 } else {
1583 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1584 }
1585 }
1586 }
1588 // ----------------------------------------------------------------------------
1589 // Lookup
1591 Klass* SystemDictionary::find_class(int index, unsigned int hash,
1592 Symbol* class_name,
1593 ClassLoaderData* loader_data) {
1594 assert_locked_or_safepoint(SystemDictionary_lock);
1595 assert (index == dictionary()->index_for(class_name, loader_data),
1596 "incorrect index?");
1598 Klass* k = dictionary()->find_class(index, hash, class_name, loader_data);
1599 return k;
1600 }
1603 // Basic find on classes in the midst of being loaded
1604 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1605 ClassLoaderData* loader_data) {
1606 assert_locked_or_safepoint(SystemDictionary_lock);
1607 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
1608 int p_index = placeholders()->hash_to_index(p_hash);
1609 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1610 }
1613 // Used for assertions and verification only
1614 Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1615 #ifndef ASSERT
1616 guarantee(VerifyBeforeGC ||
1617 VerifyDuringGC ||
1618 VerifyBeforeExit ||
1619 VerifyDuringStartup ||
1620 VerifyAfterGC, "too expensive");
1621 #endif
1622 assert_locked_or_safepoint(SystemDictionary_lock);
1624 // First look in the loaded class array
1625 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
1626 int d_index = dictionary()->hash_to_index(d_hash);
1627 return find_class(d_index, d_hash, class_name, loader_data);
1628 }
1631 // Get the next class in the diictionary.
1632 Klass* SystemDictionary::try_get_next_class() {
1633 return dictionary()->try_get_next_class();
1634 }
1637 // ----------------------------------------------------------------------------
1638 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1639 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1640 // before a new class is used.
1642 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
1643 assert(k.not_null(), "just checking");
1644 assert_locked_or_safepoint(Compile_lock);
1646 // Link into hierachy. Make sure the vtables are initialized before linking into
1647 k->append_to_sibling_list(); // add to superklass/sibling list
1648 k->process_interfaces(THREAD); // handle all "implements" declarations
1649 k->set_init_state(InstanceKlass::loaded);
1650 // Now flush all code that depended on old class hierarchy.
1651 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1652 // Also, first reinitialize vtable because it may have gotten out of synch
1653 // while the new class wasn't connected to the class hierarchy.
1654 Universe::flush_dependents_on(k);
1655 }
1658 // ----------------------------------------------------------------------------
1659 // GC support
1661 // Following roots during mark-sweep is separated in two phases.
1662 //
1663 // The first phase follows preloaded classes and all other system
1664 // classes, since these will never get unloaded anyway.
1665 //
1666 // The second phase removes (unloads) unreachable classes from the
1667 // system dictionary and follows the remaining classes' contents.
1669 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1670 blk->do_oop(&_java_system_loader);
1671 blk->do_oop(&_system_loader_lock_obj);
1673 dictionary()->always_strong_oops_do(blk);
1675 // Visit extra methods
1676 invoke_method_table()->oops_do(blk);
1677 }
1679 void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
1680 // Follow all system classes and temporary placeholders in dictionary
1681 dictionary()->always_strong_classes_do(closure);
1683 // Placeholders. These represent classes we're actively loading.
1684 placeholders()->classes_do(closure);
1685 }
1687 // Calculate a "good" systemdictionary size based
1688 // on predicted or current loaded classes count
1689 int SystemDictionary::calculate_systemdictionary_size(int classcount) {
1690 int newsize = _old_default_sdsize;
1691 if ((classcount > 0) && !DumpSharedSpaces) {
1692 int desiredsize = classcount/_average_depth_goal;
1693 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
1694 newsize = _primelist[++_sdgeneration]) {
1695 if (desiredsize <= newsize) {
1696 break;
1697 }
1698 }
1699 }
1700 return newsize;
1701 }
1703 #ifdef ASSERT
1704 class VerifySDReachableAndLiveClosure : public OopClosure {
1705 private:
1706 BoolObjectClosure* _is_alive;
1708 template <class T> void do_oop_work(T* p) {
1709 oop obj = oopDesc::load_decode_heap_oop(p);
1710 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
1711 }
1713 public:
1714 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
1716 virtual void do_oop(oop* p) { do_oop_work(p); }
1717 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1718 };
1719 #endif
1721 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1722 // Note: anonymous classes are not in the SD.
1723 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
1724 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1725 bool has_dead_loaders = ClassLoaderDataGraph::do_unloading(is_alive);
1726 bool unloading_occurred = false;
1727 if (has_dead_loaders) {
1728 unloading_occurred = dictionary()->do_unloading();
1729 constraints()->purge_loader_constraints();
1730 resolution_errors()->purge_resolution_errors();
1731 }
1732 // Oops referenced by the system dictionary may get unreachable independently
1733 // of the class loader (eg. cached protection domain oops). So we need to
1734 // explicitly unlink them here instead of in Dictionary::do_unloading.
1735 dictionary()->unlink(is_alive);
1736 #ifdef ASSERT
1737 VerifySDReachableAndLiveClosure cl(is_alive);
1738 dictionary()->oops_do(&cl);
1739 #endif
1740 return unloading_occurred;
1741 }
1743 void SystemDictionary::oops_do(OopClosure* f) {
1744 f->do_oop(&_java_system_loader);
1745 f->do_oop(&_system_loader_lock_obj);
1747 // Adjust dictionary
1748 dictionary()->oops_do(f);
1750 // Visit extra methods
1751 invoke_method_table()->oops_do(f);
1752 }
1754 // Extended Class redefinition support.
1755 // If one of these classes is replaced, we need to replace it in these places.
1756 // KlassClosure::do_klass should take the address of a class but we can
1757 // change that later.
1758 void SystemDictionary::preloaded_classes_do(KlassClosure* f) {
1759 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
1760 f->do_klass(_well_known_klasses[k]);
1761 }
1763 {
1764 for (int i = 0; i < T_VOID+1; i++) {
1765 if (_box_klasses[i] != NULL) {
1766 assert(i >= T_BOOLEAN, "checking");
1767 f->do_klass(_box_klasses[i]);
1768 }
1769 }
1770 }
1772 FilteredFieldsMap::classes_do(f);
1773 }
1775 void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) {
1776 f->do_klass(_abstract_ownable_synchronizer_klass);
1777 }
1779 // Just the classes from defining class loaders
1780 // Don't iterate over placeholders
1781 void SystemDictionary::classes_do(void f(Klass*)) {
1782 dictionary()->classes_do(f);
1783 }
1785 // Added for initialize_itable_for_klass
1786 // Just the classes from defining class loaders
1787 // Don't iterate over placeholders
1788 void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
1789 dictionary()->classes_do(f, CHECK);
1790 }
1792 // All classes, and their class loaders
1793 // Don't iterate over placeholders
1794 void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
1795 dictionary()->classes_do(f);
1796 }
1798 void SystemDictionary::placeholders_do(void f(Symbol*)) {
1799 placeholders()->entries_do(f);
1800 }
1802 void SystemDictionary::methods_do(void f(Method*)) {
1803 dictionary()->methods_do(f);
1804 invoke_method_table()->methods_do(f);
1805 }
1807 // ----------------------------------------------------------------------------
1808 // Lazily load klasses
1810 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
1811 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later");
1813 // if multiple threads calling this function, only one thread will load
1814 // the class. The other threads will find the loaded version once the
1815 // class is loaded.
1816 Klass* aos = _abstract_ownable_synchronizer_klass;
1817 if (aos == NULL) {
1818 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
1819 // Force a fence to prevent any read before the write completes
1820 OrderAccess::fence();
1821 _abstract_ownable_synchronizer_klass = k;
1822 }
1823 }
1825 // ----------------------------------------------------------------------------
1826 // Initialization
1828 void SystemDictionary::initialize(TRAPS) {
1829 // Allocate arrays
1830 assert(dictionary() == NULL,
1831 "SystemDictionary should only be initialized once");
1832 _sdgeneration = 0;
1833 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
1834 _placeholders = new PlaceholderTable(_nof_buckets);
1835 _number_of_modifications = 0;
1836 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1837 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1838 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
1840 // Allocate private object used as system class loader lock
1841 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
1842 // Initialize basic classes
1843 initialize_preloaded_classes(CHECK);
1844 }
1846 // Compact table of directions on the initialization of klasses:
1847 static const short wk_init_info[] = {
1848 #define WK_KLASS_INIT_INFO(name, symbol, option) \
1849 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
1850 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
1851 | (int)SystemDictionary::option ),
1852 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1853 #undef WK_KLASS_INIT_INFO
1854 0
1855 };
1857 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
1858 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1859 int info = wk_init_info[id - FIRST_WKID];
1860 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1861 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1862 Klass** klassp = &_well_known_klasses[id];
1863 bool must_load = (init_opt < SystemDictionary::Opt);
1864 if ((*klassp) == NULL) {
1865 if (must_load) {
1866 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class
1867 } else {
1868 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass
1869 }
1870 }
1871 return ((*klassp) != NULL);
1872 }
1874 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1875 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1876 for (int id = (int)start_id; id < (int)limit_id; id++) {
1877 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1878 int info = wk_init_info[id - FIRST_WKID];
1879 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1880 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
1882 initialize_wk_klass((WKID)id, opt, CHECK);
1883 }
1885 // move the starting value forward to the limit:
1886 start_id = limit_id;
1887 }
1889 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
1890 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
1891 // Preload commonly used klasses
1892 WKID scan = FIRST_WKID;
1893 // first do Object, then String, Class
1894 if (UseSharedSpaces) {
1895 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
1896 // Initialize the constant pool for the Object_class
1897 InstanceKlass* ik = InstanceKlass::cast(Object_klass());
1898 ik->constants()->restore_unshareable_info(CHECK);
1899 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1900 } else {
1901 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1902 }
1904 // Calculate offsets for String and Class classes since they are loaded and
1905 // can be used after this point.
1906 java_lang_String::compute_offsets();
1907 java_lang_Class::compute_offsets();
1909 // Fixup mirrors for classes loaded before java.lang.Class.
1910 // These calls iterate over the objects currently in the perm gen
1911 // so calling them at this point is matters (not before when there
1912 // are fewer objects and not later after there are more objects
1913 // in the perm gen.
1914 Universe::initialize_basic_type_mirrors(CHECK);
1915 Universe::fixup_mirrors(CHECK);
1917 // do a bunch more:
1918 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
1920 // Preload ref klasses and set reference types
1921 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
1922 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
1924 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
1925 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
1926 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
1927 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
1928 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
1930 // JSR 292 classes
1931 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
1932 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
1933 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
1934 if (EnableInvokeDynamic) {
1935 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
1936 } else {
1937 // Skip the JSR 292 classes, if not enabled.
1938 scan = WKID(jsr292_group_end + 1);
1939 }
1941 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK);
1943 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
1944 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
1945 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
1946 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
1947 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
1948 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
1949 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
1950 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
1951 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
1952 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
1954 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
1955 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
1956 _has_loadClassInternal = (method != NULL);
1957 }
1958 { // Compute whether we should use checkPackageAccess or NOT
1959 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
1960 _has_checkPackageAccess = (method != NULL);
1961 }
1962 }
1964 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
1965 // If so, returns the basic type it holds. If not, returns T_OBJECT.
1966 BasicType SystemDictionary::box_klass_type(Klass* k) {
1967 assert(k != NULL, "");
1968 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
1969 if (_box_klasses[i] == k)
1970 return (BasicType)i;
1971 }
1972 return T_OBJECT;
1973 }
1975 // Constraints on class loaders. The details of the algorithm can be
1976 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
1977 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
1978 // that the system dictionary needs to maintain a set of contraints that
1979 // must be satisfied by all classes in the dictionary.
1980 // if defining is true, then LinkageError if already in systemDictionary
1981 // if initiating loader, then ok if InstanceKlass matches existing entry
1983 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
1984 instanceKlassHandle k,
1985 Handle class_loader, bool defining,
1986 TRAPS) {
1987 const char *linkage_error = NULL;
1988 {
1989 Symbol* name = k->name();
1990 ClassLoaderData *loader_data = class_loader_data(class_loader);
1992 MutexLocker mu(SystemDictionary_lock, THREAD);
1994 Klass* check = find_class(d_index, d_hash, name, loader_data);
1995 if (check != (Klass*)NULL) {
1996 // if different InstanceKlass - duplicate class definition,
1997 // else - ok, class loaded by a different thread in parallel,
1998 // we should only have found it if it was done loading and ok to use
1999 // system dictionary only holds instance classes, placeholders
2000 // also holds array classes
2002 assert(check->oop_is_instance(), "noninstance in systemdictionary");
2003 if ((defining == true) || (k() != check)) {
2004 linkage_error = "loader (instance of %s): attempted duplicate class "
2005 "definition for name: \"%s\"";
2006 } else {
2007 return;
2008 }
2009 }
2011 #ifdef ASSERT
2012 Symbol* ph_check = find_placeholder(name, loader_data);
2013 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2014 #endif
2016 if (linkage_error == NULL) {
2017 if (constraints()->check_or_update(k, class_loader, name) == false) {
2018 linkage_error = "loader constraint violation: loader (instance of %s)"
2019 " previously initiated loading for a different type with name \"%s\"";
2020 }
2021 }
2022 }
2024 // Throw error now if needed (cannot throw while holding
2025 // SystemDictionary_lock because of rank ordering)
2027 if (linkage_error) {
2028 ResourceMark rm(THREAD);
2029 const char* class_loader_name = loader_name(class_loader());
2030 char* type_name = k->name()->as_C_string();
2031 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) +
2032 strlen(type_name);
2033 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
2034 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name);
2035 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
2036 }
2037 }
2040 // Update system dictionary - done after check_constraint and add_to_hierachy
2041 // have been called.
2042 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
2043 int p_index, unsigned int p_hash,
2044 instanceKlassHandle k,
2045 Handle class_loader,
2046 TRAPS) {
2047 // Compile_lock prevents systemDictionary updates during compilations
2048 assert_locked_or_safepoint(Compile_lock);
2049 Symbol* name = k->name();
2050 ClassLoaderData *loader_data = class_loader_data(class_loader);
2052 {
2053 MutexLocker mu1(SystemDictionary_lock, THREAD);
2055 // See whether biased locking is enabled and if so set it for this
2056 // klass.
2057 // Note that this must be done past the last potential blocking
2058 // point / safepoint. We enable biased locking lazily using a
2059 // VM_Operation to iterate the SystemDictionary and installing the
2060 // biasable mark word into each InstanceKlass's prototype header.
2061 // To avoid race conditions where we accidentally miss enabling the
2062 // optimization for one class in the process of being added to the
2063 // dictionary, we must not safepoint after the test of
2064 // BiasedLocking::enabled().
2065 if (UseBiasedLocking && BiasedLocking::enabled()) {
2066 // Set biased locking bit for all loaded classes; it will be
2067 // cleared if revocation occurs too often for this type
2068 // NOTE that we must only do this when the class is initally
2069 // defined, not each time it is referenced from a new class loader
2070 if (k->class_loader() == class_loader()) {
2071 k->set_prototype_header(markOopDesc::biased_locking_prototype());
2072 }
2073 }
2075 // Make a new system dictionary entry.
2076 Klass* sd_check = find_class(d_index, d_hash, name, loader_data);
2077 if (sd_check == NULL) {
2078 dictionary()->add_klass(name, loader_data, k);
2079 notice_modification();
2080 }
2081 #ifdef ASSERT
2082 sd_check = find_class(d_index, d_hash, name, loader_data);
2083 assert (sd_check != NULL, "should have entry in system dictionary");
2084 // Note: there may be a placeholder entry: for circularity testing
2085 // or for parallel defines
2086 #endif
2087 SystemDictionary_lock->notify_all();
2088 }
2089 }
2092 // Try to find a class name using the loader constraints. The
2093 // loader constraints might know about a class that isn't fully loaded
2094 // yet and these will be ignored.
2095 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2096 Symbol* class_name, Handle class_loader, TRAPS) {
2098 // First see if it has been loaded directly.
2099 // Force the protection domain to be null. (This removes protection checks.)
2100 Handle no_protection_domain;
2101 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2102 no_protection_domain, CHECK_NULL);
2103 if (klass != NULL)
2104 return klass;
2106 // Now look to see if it has been loaded elsewhere, and is subject to
2107 // a loader constraint that would require this loader to return the
2108 // klass that is already loaded.
2109 if (FieldType::is_array(class_name)) {
2110 // For array classes, their Klass*s are not kept in the
2111 // constraint table. The element Klass*s are.
2112 FieldArrayInfo fd;
2113 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
2114 if (t != T_OBJECT) {
2115 klass = Universe::typeArrayKlassObj(t);
2116 } else {
2117 MutexLocker mu(SystemDictionary_lock, THREAD);
2118 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
2119 }
2120 // If element class already loaded, allocate array klass
2121 if (klass != NULL) {
2122 klass = klass->array_klass_or_null(fd.dimension());
2123 }
2124 } else {
2125 MutexLocker mu(SystemDictionary_lock, THREAD);
2126 // Non-array classes are easy: simply check the constraint table.
2127 klass = constraints()->find_constrained_klass(class_name, class_loader);
2128 }
2130 return klass;
2131 }
2134 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2135 Handle class_loader1,
2136 Handle class_loader2,
2137 Thread* THREAD) {
2138 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2139 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2141 Symbol* constraint_name = NULL;
2142 if (!FieldType::is_array(class_name)) {
2143 constraint_name = class_name;
2144 } else {
2145 // For array classes, their Klass*s are not kept in the
2146 // constraint table. The element classes are.
2147 FieldArrayInfo fd;
2148 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
2149 // primitive types always pass
2150 if (t != T_OBJECT) {
2151 return true;
2152 } else {
2153 constraint_name = fd.object_key();
2154 }
2155 }
2156 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
2157 int d_index1 = dictionary()->hash_to_index(d_hash1);
2159 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
2160 int d_index2 = dictionary()->hash_to_index(d_hash2);
2161 {
2162 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2164 // Better never do a GC while we're holding these oops
2165 No_Safepoint_Verifier nosafepoint;
2167 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
2168 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
2169 return constraints()->add_entry(constraint_name, klass1, class_loader1,
2170 klass2, class_loader2);
2171 }
2172 }
2174 // Add entry to resolution error table to record the error when the first
2175 // attempt to resolve a reference to a class has failed.
2176 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, Symbol* error) {
2177 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2178 int index = resolution_errors()->hash_to_index(hash);
2179 {
2180 MutexLocker ml(SystemDictionary_lock, Thread::current());
2181 resolution_errors()->add_entry(index, hash, pool, which, error);
2182 }
2183 }
2185 // Delete a resolution error for RedefineClasses for a constant pool is going away
2186 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2187 resolution_errors()->delete_entry(pool);
2188 }
2190 // Lookup resolution error table. Returns error if found, otherwise NULL.
2191 Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) {
2192 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2193 int index = resolution_errors()->hash_to_index(hash);
2194 {
2195 MutexLocker ml(SystemDictionary_lock, Thread::current());
2196 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2197 return (entry != NULL) ? entry->error() : (Symbol*)NULL;
2198 }
2199 }
2202 // Signature constraints ensure that callers and callees agree about
2203 // the meaning of type names in their signatures. This routine is the
2204 // intake for constraints. It collects them from several places:
2205 //
2206 // * LinkResolver::resolve_method (if check_access is true) requires
2207 // that the resolving class (the caller) and the defining class of
2208 // the resolved method (the callee) agree on each type in the
2209 // method's signature.
2210 //
2211 // * LinkResolver::resolve_interface_method performs exactly the same
2212 // checks.
2213 //
2214 // * LinkResolver::resolve_field requires that the constant pool
2215 // attempting to link to a field agree with the field's defining
2216 // class about the type of the field signature.
2217 //
2218 // * klassVtable::initialize_vtable requires that, when a class
2219 // overrides a vtable entry allocated by a superclass, that the
2220 // overriding method (i.e., the callee) agree with the superclass
2221 // on each type in the method's signature.
2222 //
2223 // * klassItable::initialize_itable requires that, when a class fills
2224 // in its itables, for each non-abstract method installed in an
2225 // itable, the method (i.e., the callee) agree with the interface
2226 // on each type in the method's signature.
2227 //
2228 // All those methods have a boolean (check_access, checkconstraints)
2229 // which turns off the checks. This is used from specialized contexts
2230 // such as bootstrapping, dumping, and debugging.
2231 //
2232 // No direct constraint is placed between the class and its
2233 // supertypes. Constraints are only placed along linked relations
2234 // between callers and callees. When a method overrides or implements
2235 // an abstract method in a supertype (superclass or interface), the
2236 // constraints are placed as if the supertype were the caller to the
2237 // overriding method. (This works well, since callers to the
2238 // supertype have already established agreement between themselves and
2239 // the supertype.) As a result of all this, a class can disagree with
2240 // its supertype about the meaning of a type name, as long as that
2241 // class neither calls a relevant method of the supertype, nor is
2242 // called (perhaps via an override) from the supertype.
2243 //
2244 //
2245 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2246 //
2247 // Make sure all class components (including arrays) in the given
2248 // signature will be resolved to the same class in both loaders.
2249 // Returns the name of the type that failed a loader constraint check, or
2250 // NULL if no constraint failed. No exception except OOME is thrown.
2251 // Arrays are not added to the loader constraint table, their elements are.
2252 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2253 Handle loader1, Handle loader2,
2254 bool is_method, TRAPS) {
2255 // Nothing to do if loaders are the same.
2256 if (loader1() == loader2()) {
2257 return NULL;
2258 }
2260 SignatureStream sig_strm(signature, is_method);
2261 while (!sig_strm.is_done()) {
2262 if (sig_strm.is_object()) {
2263 Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
2264 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2265 return sig;
2266 }
2267 }
2268 sig_strm.next();
2269 }
2270 return NULL;
2271 }
2274 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2275 Symbol* signature,
2276 TRAPS) {
2277 methodHandle empty;
2278 assert(EnableInvokeDynamic, "");
2279 assert(MethodHandles::is_signature_polymorphic(iid) &&
2280 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2281 iid != vmIntrinsics::_invokeGeneric,
2282 err_msg("must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid)));
2284 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2285 int index = invoke_method_table()->hash_to_index(hash);
2286 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2287 methodHandle m;
2288 if (spe == NULL || spe->method() == NULL) {
2289 spe = NULL;
2290 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2291 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
2292 CompileBroker::compile_method(m, InvocationEntryBci, CompLevel_highest_tier,
2293 methodHandle(), CompileThreshold, "MH", CHECK_(empty));
2295 // Now grab the lock. We might have to throw away the new method,
2296 // if a racing thread has managed to install one at the same time.
2297 {
2298 MutexLocker ml(SystemDictionary_lock, THREAD);
2299 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2300 if (spe == NULL)
2301 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2302 if (spe->method() == NULL)
2303 spe->set_method(m());
2304 }
2305 }
2307 assert(spe != NULL && spe->method() != NULL, "");
2308 return spe->method();
2309 }
2311 // Helper for unpacking the return value from linkMethod and linkCallSite.
2312 static methodHandle unpack_method_and_appendix(Handle mname,
2313 KlassHandle accessing_klass,
2314 objArrayHandle appendix_box,
2315 Handle* appendix_result,
2316 TRAPS) {
2317 methodHandle empty;
2318 if (mname.not_null()) {
2319 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
2320 if (vmtarget != NULL && vmtarget->is_method()) {
2321 Method* m = (Method*)vmtarget;
2322 oop appendix = appendix_box->obj_at(0);
2323 if (TraceMethodHandles) {
2324 #ifndef PRODUCT
2325 tty->print("Linked method="INTPTR_FORMAT": ", m);
2326 m->print();
2327 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2328 tty->cr();
2329 #endif //PRODUCT
2330 }
2331 (*appendix_result) = Handle(THREAD, appendix);
2332 // the target is stored in the cpCache and if a reference to this
2333 // MethodName is dropped we need a way to make sure the
2334 // class_loader containing this method is kept alive.
2335 // FIXME: the appendix might also preserve this dependency.
2336 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data();
2337 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
2338 return methodHandle(THREAD, m);
2339 }
2340 }
2341 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
2342 return empty;
2343 }
2345 methodHandle SystemDictionary::find_method_handle_invoker(Symbol* name,
2346 Symbol* signature,
2347 KlassHandle accessing_klass,
2348 Handle *appendix_result,
2349 Handle *method_type_result,
2350 TRAPS) {
2351 methodHandle empty;
2352 assert(EnableInvokeDynamic, "");
2353 assert(!THREAD->is_Compiler_thread(), "");
2354 Handle method_type =
2355 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
2356 if (false) { // FIXME: Decide if the Java upcall should resolve signatures.
2357 method_type = java_lang_String::create_from_symbol(signature, CHECK_(empty));
2358 }
2360 KlassHandle mh_klass = SystemDictionary::MethodHandle_klass();
2361 int ref_kind = JVM_REF_invokeVirtual;
2362 Handle name_str = StringTable::intern(name, CHECK_(empty));
2363 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2364 assert(appendix_box->obj_at(0) == NULL, "");
2366 // This should not happen. JDK code should take care of that.
2367 if (accessing_klass.is_null() || method_type.is_null()) {
2368 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
2369 }
2371 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2372 JavaCallArguments args;
2373 args.push_oop(accessing_klass()->java_mirror());
2374 args.push_int(ref_kind);
2375 args.push_oop(mh_klass()->java_mirror());
2376 args.push_oop(name_str());
2377 args.push_oop(method_type());
2378 args.push_oop(appendix_box());
2379 JavaValue result(T_OBJECT);
2380 JavaCalls::call_static(&result,
2381 SystemDictionary::MethodHandleNatives_klass(),
2382 vmSymbols::linkMethod_name(),
2383 vmSymbols::linkMethod_signature(),
2384 &args, CHECK_(empty));
2385 Handle mname(THREAD, (oop) result.get_jobject());
2386 (*method_type_result) = method_type;
2387 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2388 }
2391 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2392 // signature, as interpreted relative to the given class loader.
2393 // Because of class loader constraints, all method handle usage must be
2394 // consistent with this loader.
2395 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2396 KlassHandle accessing_klass,
2397 TRAPS) {
2398 Handle empty;
2399 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2400 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2401 int index = invoke_method_table()->hash_to_index(hash);
2402 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2403 if (spe != NULL && spe->method_type() != NULL) {
2404 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2405 return Handle(THREAD, spe->method_type());
2406 } else if (THREAD->is_Compiler_thread()) {
2407 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2408 return Handle(); // do not attempt from within compiler, unless it was cached
2409 }
2411 Handle class_loader, protection_domain;
2412 bool is_on_bcp = true; // keep this true as long as we can materialize from the boot classloader
2413 int npts = ArgumentCount(signature).size();
2414 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2415 int arg = 0;
2416 Handle rt; // the return type from the signature
2417 ResourceMark rm(THREAD);
2418 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2419 oop mirror = NULL;
2420 if (is_on_bcp) {
2421 // Note: class_loader & protection_domain are both null at this point.
2422 mirror = ss.as_java_mirror(class_loader, protection_domain,
2423 SignatureStream::ReturnNull, CHECK_(empty));
2424 if (mirror == NULL) {
2425 // fall back from BCP to accessing_klass
2426 if (accessing_klass.not_null()) {
2427 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader());
2428 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain());
2429 }
2430 is_on_bcp = false;
2431 }
2432 }
2433 if (!is_on_bcp) {
2434 // Resolve, throwing a real error if it doesn't work.
2435 mirror = ss.as_java_mirror(class_loader, protection_domain,
2436 SignatureStream::NCDFError, CHECK_(empty));
2437 }
2438 if (ss.at_return_type())
2439 rt = Handle(THREAD, mirror);
2440 else
2441 pts->obj_at_put(arg++, mirror);
2443 // Check accessibility.
2444 if (ss.is_object() && accessing_klass.not_null()) {
2445 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2446 mirror = NULL; // safety
2447 // Emulate ConstantPool::verify_constant_pool_resolve.
2448 if (sel_klass->oop_is_objArray())
2449 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
2450 if (sel_klass->oop_is_instance()) {
2451 KlassHandle sel_kh(THREAD, sel_klass);
2452 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty));
2453 }
2454 }
2455 }
2456 assert(arg == npts, "");
2458 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType
2459 JavaCallArguments args(Handle(THREAD, rt()));
2460 args.push_oop(pts());
2461 JavaValue result(T_OBJECT);
2462 JavaCalls::call_static(&result,
2463 SystemDictionary::MethodHandleNatives_klass(),
2464 vmSymbols::findMethodHandleType_name(),
2465 vmSymbols::findMethodHandleType_signature(),
2466 &args, CHECK_(empty));
2467 Handle method_type(THREAD, (oop) result.get_jobject());
2469 if (is_on_bcp) {
2470 // We can cache this MethodType inside the JVM.
2471 MutexLocker ml(SystemDictionary_lock, THREAD);
2472 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2473 if (spe == NULL)
2474 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2475 if (spe->method_type() == NULL) {
2476 spe->set_method_type(method_type());
2477 }
2478 }
2480 // report back to the caller with the MethodType
2481 return method_type;
2482 }
2484 // Ask Java code to find or construct a method handle constant.
2485 Handle SystemDictionary::link_method_handle_constant(KlassHandle caller,
2486 int ref_kind, //e.g., JVM_REF_invokeVirtual
2487 KlassHandle callee,
2488 Symbol* name_sym,
2489 Symbol* signature,
2490 TRAPS) {
2491 Handle empty;
2492 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
2493 Handle type;
2494 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
2495 type = find_method_handle_type(signature, caller, CHECK_(empty));
2496 } else if (caller.is_null()) {
2497 // This should not happen. JDK code should take care of that.
2498 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2499 } else {
2500 ResourceMark rm(THREAD);
2501 SignatureStream ss(signature, false);
2502 if (!ss.is_done()) {
2503 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(),
2504 SignatureStream::NCDFError, CHECK_(empty));
2505 type = Handle(THREAD, mirror);
2506 ss.next();
2507 if (!ss.is_done()) type = Handle(); // error!
2508 }
2509 }
2510 if (type.is_null()) {
2511 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
2512 }
2514 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2515 JavaCallArguments args;
2516 args.push_oop(caller->java_mirror()); // the referring class
2517 args.push_int(ref_kind);
2518 args.push_oop(callee->java_mirror()); // the target class
2519 args.push_oop(name());
2520 args.push_oop(type());
2521 JavaValue result(T_OBJECT);
2522 JavaCalls::call_static(&result,
2523 SystemDictionary::MethodHandleNatives_klass(),
2524 vmSymbols::linkMethodHandleConstant_name(),
2525 vmSymbols::linkMethodHandleConstant_signature(),
2526 &args, CHECK_(empty));
2527 return Handle(THREAD, (oop) result.get_jobject());
2528 }
2530 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given
2531 // name and signature, as interpreted relative to the given class loader.
2532 methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller,
2533 Handle bootstrap_specifier,
2534 Symbol* name,
2535 Symbol* type,
2536 Handle *appendix_result,
2537 Handle *method_type_result,
2538 TRAPS) {
2539 methodHandle empty;
2540 Handle bsm, info;
2541 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
2542 bsm = bootstrap_specifier;
2543 } else {
2544 assert(bootstrap_specifier->is_objArray(), "");
2545 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
2546 int len = args->length();
2547 assert(len >= 1, "");
2548 bsm = Handle(THREAD, args->obj_at(0));
2549 if (len > 1) {
2550 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
2551 for (int i = 1; i < len; i++)
2552 args1->obj_at_put(i-1, args->obj_at(i));
2553 info = Handle(THREAD, args1);
2554 }
2555 }
2556 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
2557 "caller must supply a valid BSM");
2559 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
2560 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
2562 // This should not happen. JDK code should take care of that.
2563 if (caller.is_null() || method_type.is_null()) {
2564 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
2565 }
2567 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2568 assert(appendix_box->obj_at(0) == NULL, "");
2570 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
2571 JavaCallArguments args;
2572 args.push_oop(caller->java_mirror());
2573 args.push_oop(bsm());
2574 args.push_oop(method_name());
2575 args.push_oop(method_type());
2576 args.push_oop(info());
2577 args.push_oop(appendix_box);
2578 JavaValue result(T_OBJECT);
2579 JavaCalls::call_static(&result,
2580 SystemDictionary::MethodHandleNatives_klass(),
2581 vmSymbols::linkCallSite_name(),
2582 vmSymbols::linkCallSite_signature(),
2583 &args, CHECK_(empty));
2584 Handle mname(THREAD, (oop) result.get_jobject());
2585 (*method_type_result) = method_type;
2586 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
2587 }
2589 // Since the identity hash code for symbols changes when the symbols are
2590 // moved from the regular perm gen (hash in the mark word) to the shared
2591 // spaces (hash is the address), the classes loaded into the dictionary
2592 // may be in the wrong buckets.
2594 void SystemDictionary::reorder_dictionary() {
2595 dictionary()->reorder_dictionary();
2596 }
2599 void SystemDictionary::copy_buckets(char** top, char* end) {
2600 dictionary()->copy_buckets(top, end);
2601 }
2604 void SystemDictionary::copy_table(char** top, char* end) {
2605 dictionary()->copy_table(top, end);
2606 }
2609 void SystemDictionary::reverse() {
2610 dictionary()->reverse();
2611 }
2613 int SystemDictionary::number_of_classes() {
2614 return dictionary()->number_of_entries();
2615 }
2618 // ----------------------------------------------------------------------------
2619 #ifndef PRODUCT
2621 void SystemDictionary::print() {
2622 dictionary()->print();
2624 // Placeholders
2625 GCMutexLocker mu(SystemDictionary_lock);
2626 placeholders()->print();
2628 // loader constraints - print under SD_lock
2629 constraints()->print();
2630 }
2632 #endif
2634 void SystemDictionary::verify() {
2635 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2636 guarantee(constraints() != NULL,
2637 "Verify of loader constraints failed");
2638 guarantee(dictionary()->number_of_entries() >= 0 &&
2639 placeholders()->number_of_entries() >= 0,
2640 "Verify of system dictionary failed");
2642 // Verify dictionary
2643 dictionary()->verify();
2645 GCMutexLocker mu(SystemDictionary_lock);
2646 placeholders()->verify();
2648 // Verify constraint table
2649 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2650 constraints()->verify(dictionary(), placeholders());
2651 }
2654 void SystemDictionary::verify_obj_klass_present(Symbol* class_name,
2655 ClassLoaderData* loader_data) {
2656 GCMutexLocker mu(SystemDictionary_lock);
2657 Symbol* name;
2659 Klass* probe = find_class(class_name, loader_data);
2660 if (probe == NULL) {
2661 probe = SystemDictionary::find_shared_class(class_name);
2662 if (probe == NULL) {
2663 name = find_placeholder(class_name, loader_data);
2664 }
2665 }
2666 guarantee(probe != NULL || name != NULL,
2667 "Loaded klasses should be in SystemDictionary");
2668 }
2670 // utility function for class load event
2671 void SystemDictionary::post_class_load_event(const Ticks& start_time,
2672 instanceKlassHandle k,
2673 Handle initiating_loader) {
2674 #if INCLUDE_TRACE
2675 EventClassLoad event(UNTIMED);
2676 if (event.should_commit()) {
2677 event.set_starttime(start_time);
2678 event.set_loadedClass(k());
2679 oop defining_class_loader = k->class_loader();
2680 event.set_definingClassLoader(defining_class_loader != NULL ?
2681 defining_class_loader->klass() : (Klass*)NULL);
2682 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader();
2683 event.set_initiatingClassLoader(class_loader != NULL ?
2684 class_loader->klass() : (Klass*)NULL);
2685 event.commit();
2686 }
2687 #endif /* INCLUDE_TRACE */
2688 }
2690 #ifndef PRODUCT
2692 // statistics code
2693 class ClassStatistics: AllStatic {
2694 private:
2695 static int nclasses; // number of classes
2696 static int nmethods; // number of methods
2697 static int nmethoddata; // number of methodData
2698 static int class_size; // size of class objects in words
2699 static int method_size; // size of method objects in words
2700 static int debug_size; // size of debug info in methods
2701 static int methoddata_size; // size of methodData objects in words
2703 static void do_class(Klass* k) {
2704 nclasses++;
2705 class_size += k->size();
2706 if (k->oop_is_instance()) {
2707 InstanceKlass* ik = (InstanceKlass*)k;
2708 class_size += ik->methods()->size();
2709 class_size += ik->constants()->size();
2710 class_size += ik->local_interfaces()->size();
2711 class_size += ik->transitive_interfaces()->size();
2712 // We do not have to count implementors, since we only store one!
2713 // SSS: How should these be accounted now that they have moved?
2714 // class_size += ik->fields()->length();
2715 }
2716 }
2718 static void do_method(Method* m) {
2719 nmethods++;
2720 method_size += m->size();
2721 // class loader uses same objArray for empty vectors, so don't count these
2722 if (m->has_stackmap_table()) {
2723 method_size += m->stackmap_data()->size();
2724 }
2726 MethodData* mdo = m->method_data();
2727 if (mdo != NULL) {
2728 nmethoddata++;
2729 methoddata_size += mdo->size();
2730 }
2731 }
2733 public:
2734 static void print() {
2735 SystemDictionary::classes_do(do_class);
2736 SystemDictionary::methods_do(do_method);
2737 tty->print_cr("Class statistics:");
2738 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize);
2739 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods,
2740 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize);
2741 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize);
2742 }
2743 };
2746 int ClassStatistics::nclasses = 0;
2747 int ClassStatistics::nmethods = 0;
2748 int ClassStatistics::nmethoddata = 0;
2749 int ClassStatistics::class_size = 0;
2750 int ClassStatistics::method_size = 0;
2751 int ClassStatistics::debug_size = 0;
2752 int ClassStatistics::methoddata_size = 0;
2754 void SystemDictionary::print_class_statistics() {
2755 ResourceMark rm;
2756 ClassStatistics::print();
2757 }
2760 class MethodStatistics: AllStatic {
2761 public:
2762 enum {
2763 max_parameter_size = 10
2764 };
2765 private:
2767 static int _number_of_methods;
2768 static int _number_of_final_methods;
2769 static int _number_of_static_methods;
2770 static int _number_of_native_methods;
2771 static int _number_of_synchronized_methods;
2772 static int _number_of_profiled_methods;
2773 static int _number_of_bytecodes;
2774 static int _parameter_size_profile[max_parameter_size];
2775 static int _bytecodes_profile[Bytecodes::number_of_java_codes];
2777 static void initialize() {
2778 _number_of_methods = 0;
2779 _number_of_final_methods = 0;
2780 _number_of_static_methods = 0;
2781 _number_of_native_methods = 0;
2782 _number_of_synchronized_methods = 0;
2783 _number_of_profiled_methods = 0;
2784 _number_of_bytecodes = 0;
2785 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0;
2786 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0;
2787 };
2789 static void do_method(Method* m) {
2790 _number_of_methods++;
2791 // collect flag info
2792 if (m->is_final() ) _number_of_final_methods++;
2793 if (m->is_static() ) _number_of_static_methods++;
2794 if (m->is_native() ) _number_of_native_methods++;
2795 if (m->is_synchronized()) _number_of_synchronized_methods++;
2796 if (m->method_data() != NULL) _number_of_profiled_methods++;
2797 // collect parameter size info (add one for receiver, if any)
2798 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++;
2799 // collect bytecodes info
2800 {
2801 Thread *thread = Thread::current();
2802 HandleMark hm(thread);
2803 BytecodeStream s(methodHandle(thread, m));
2804 Bytecodes::Code c;
2805 while ((c = s.next()) >= 0) {
2806 _number_of_bytecodes++;
2807 _bytecodes_profile[c]++;
2808 }
2809 }
2810 }
2812 public:
2813 static void print() {
2814 initialize();
2815 SystemDictionary::methods_do(do_method);
2816 // generate output
2817 tty->cr();
2818 tty->print_cr("Method statistics (static):");
2819 // flag distribution
2820 tty->cr();
2821 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods);
2822 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods);
2823 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods);
2824 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods);
2825 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods);
2826 // parameter size profile
2827 tty->cr();
2828 { int tot = 0;
2829 int avg = 0;
2830 for (int i = 0; i < max_parameter_size; i++) {
2831 int n = _parameter_size_profile[i];
2832 tot += n;
2833 avg += n*i;
2834 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods);
2835 }
2836 assert(tot == _number_of_methods, "should be the same");
2837 tty->print_cr(" %6d methods 100.0%%", _number_of_methods);
2838 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods);
2839 }
2840 // bytecodes profile
2841 tty->cr();
2842 { int tot = 0;
2843 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) {
2844 if (Bytecodes::is_defined(i)) {
2845 Bytecodes::Code c = Bytecodes::cast(i);
2846 int n = _bytecodes_profile[c];
2847 tot += n;
2848 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c));
2849 }
2850 }
2851 assert(tot == _number_of_bytecodes, "should be the same");
2852 tty->print_cr("%9d 100.000%%", _number_of_bytecodes);
2853 }
2854 tty->cr();
2855 }
2856 };
2858 int MethodStatistics::_number_of_methods;
2859 int MethodStatistics::_number_of_final_methods;
2860 int MethodStatistics::_number_of_static_methods;
2861 int MethodStatistics::_number_of_native_methods;
2862 int MethodStatistics::_number_of_synchronized_methods;
2863 int MethodStatistics::_number_of_profiled_methods;
2864 int MethodStatistics::_number_of_bytecodes;
2865 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size];
2866 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes];
2869 void SystemDictionary::print_method_statistics() {
2870 MethodStatistics::print();
2871 }
2873 #endif // PRODUCT