1 /*
2 * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_systemDictionary.cpp.incl"
27
28
29 Dictionary* SystemDictionary::_dictionary = NULL;
30 PlaceholderTable* SystemDictionary::_placeholders = NULL;
31 Dictionary* SystemDictionary::_shared_dictionary = NULL;
32 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
33 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
34
35
36 int SystemDictionary::_number_of_modifications = 0;
37
38 oop SystemDictionary::_system_loader_lock_obj = NULL;
39
40 klassOop SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
41 = { NULL /*, NULL...*/ };
42
43 klassOop SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
44
45 oop SystemDictionary::_java_system_loader = NULL;
46
47 bool SystemDictionary::_has_loadClassInternal = false;
48 bool SystemDictionary::_has_checkPackageAccess = false;
49
50 // lazily initialized klass variables
51 volatile klassOop SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
52
53
54 // ----------------------------------------------------------------------------
55 // Java-level SystemLoader
56
57 oop SystemDictionary::java_system_loader() {
58 return _java_system_loader;
59 }
60
61 void SystemDictionary::compute_java_system_loader(TRAPS) {
62 KlassHandle system_klass(THREAD, WK_KLASS(classloader_klass));
63 JavaValue result(T_OBJECT);
64 JavaCalls::call_static(&result,
65 KlassHandle(THREAD, WK_KLASS(classloader_klass)),
66 vmSymbolHandles::getSystemClassLoader_name(),
67 vmSymbolHandles::void_classloader_signature(),
68 CHECK);
69
70 _java_system_loader = (oop)result.get_jobject();
71 }
72
73
74 // ----------------------------------------------------------------------------
75 // debugging
76
77 #ifdef ASSERT
78
79 // return true if class_name contains no '.' (internal format is '/')
80 bool SystemDictionary::is_internal_format(symbolHandle class_name) {
81 if (class_name.not_null()) {
82 ResourceMark rm;
83 char* name = class_name->as_C_string();
84 return strchr(name, '.') == NULL;
85 } else {
86 return true;
87 }
88 }
89
90 #endif
91
92 // ----------------------------------------------------------------------------
93 // Resolving of classes
94
95 // Forwards to resolve_or_null
96
97 klassOop SystemDictionary::resolve_or_fail(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
98 klassOop klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
99 if (HAS_PENDING_EXCEPTION || klass == NULL) {
100 KlassHandle k_h(THREAD, klass);
101 // can return a null klass
102 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
103 }
104 return klass;
105 }
106
107 klassOop SystemDictionary::handle_resolution_exception(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) {
108 if (HAS_PENDING_EXCEPTION) {
109 // If we have a pending exception we forward it to the caller, unless throw_error is true,
110 // in which case we have to check whether the pending exception is a ClassNotFoundException,
111 // and if so convert it to a NoClassDefFoundError
112 // And chain the original ClassNotFoundException
113 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::classNotFoundException_klass())) {
114 ResourceMark rm(THREAD);
115 assert(klass_h() == NULL, "Should not have result with exception pending");
116 Handle e(THREAD, PENDING_EXCEPTION);
117 CLEAR_PENDING_EXCEPTION;
118 THROW_MSG_CAUSE_0(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
119 } else {
120 return NULL;
121 }
122 }
123 // Class not found, throw appropriate error or exception depending on value of throw_error
124 if (klass_h() == NULL) {
125 ResourceMark rm(THREAD);
126 if (throw_error) {
127 THROW_MSG_0(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
128 } else {
129 THROW_MSG_0(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
130 }
131 }
132 return (klassOop)klass_h();
133 }
134
135
136 klassOop SystemDictionary::resolve_or_fail(symbolHandle class_name,
137 bool throw_error, TRAPS)
138 {
139 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
140 }
141
142
143 // Forwards to resolve_instance_class_or_null
144
145 klassOop SystemDictionary::resolve_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS) {
146 assert(!THREAD->is_Compiler_thread(), "Can not load classes with the Compiler thread");
147 if (FieldType::is_array(class_name())) {
148 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
149 } else {
150 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
151 }
152 }
153
154 klassOop SystemDictionary::resolve_or_null(symbolHandle class_name, TRAPS) {
155 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
156 }
157
158 // Forwards to resolve_instance_class_or_null
159
160 klassOop SystemDictionary::resolve_array_class_or_null(symbolHandle class_name,
161 Handle class_loader,
162 Handle protection_domain,
163 TRAPS) {
164 assert(FieldType::is_array(class_name()), "must be array");
165 jint dimension;
166 symbolOop object_key;
167 klassOop k = NULL;
168 // dimension and object_key are assigned as a side-effect of this call
169 BasicType t = FieldType::get_array_info(class_name(),
170 &dimension,
171 &object_key,
172 CHECK_NULL);
173
174 if (t == T_OBJECT) {
175 symbolHandle h_key(THREAD, object_key);
176 // naked oop "k" is OK here -- we assign back into it
177 k = SystemDictionary::resolve_instance_class_or_null(h_key,
178 class_loader,
179 protection_domain,
180 CHECK_NULL);
181 if (k != NULL) {
182 k = Klass::cast(k)->array_klass(dimension, CHECK_NULL);
183 }
184 } else {
185 k = Universe::typeArrayKlassObj(t);
186 k = typeArrayKlass::cast(k)->array_klass(dimension, CHECK_NULL);
187 }
188 return k;
189 }
190
191
192 // Must be called for any super-class or super-interface resolution
193 // during class definition to allow class circularity checking
194 // super-interface callers:
195 // parse_interfaces - for defineClass & jvmtiRedefineClasses
196 // super-class callers:
197 // ClassFileParser - for defineClass & jvmtiRedefineClasses
198 // load_shared_class - while loading a class from shared archive
199 // resolve_instance_class_or_fail:
200 // when resolving a class that has an existing placeholder with
201 // a saved superclass [i.e. a defineClass is currently in progress]
202 // if another thread is trying to resolve the class, it must do
203 // super-class checks on its own thread to catch class circularity
204 // This last call is critical in class circularity checking for cases
205 // where classloading is delegated to different threads and the
206 // classloader lock is released.
207 // Take the case: Base->Super->Base
208 // 1. If thread T1 tries to do a defineClass of class Base
209 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
210 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
211 // so it tries to load Super
212 // 3. If we load the class internally, or user classloader uses same thread
213 // loadClassFromxxx or defineClass via parseClassFile Super ...
214 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
215 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
216 // 3.4 calls resolve_super_or_fail Base
217 // 3.5 finds T1,Base -> throws class circularity
218 //OR 4. If T2 tries to resolve Super via defineClass Super ...
219 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
220 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
221 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
222 // 4.4 finds T2, Super -> throws class circularity
223 // Must be called, even if superclass is null, since this is
224 // where the placeholder entry is created which claims this
225 // thread is loading this class/classloader.
226 klassOop SystemDictionary::resolve_super_or_fail(symbolHandle child_name,
227 symbolHandle class_name,
228 Handle class_loader,
229 Handle protection_domain,
230 bool is_superclass,
231 TRAPS) {
232
233 // Try to get one of the well-known klasses.
234 // They are trusted, and do not participate in circularities.
235 if (LinkWellKnownClasses) {
236 klassOop k = find_well_known_klass(class_name());
237 if (k != NULL) {
238 return k;
239 }
240 }
241
242 // Double-check, if child class is already loaded, just return super-class,interface
243 // Don't add a placedholder if already loaded, i.e. already in system dictionary
244 // Make sure there's a placeholder for the *child* before resolving.
245 // Used as a claim that this thread is currently loading superclass/classloader
246 // Used here for ClassCircularity checks and also for heap verification
247 // (every instanceKlass in the heap needs to be in the system dictionary
248 // or have a placeholder).
249 // Must check ClassCircularity before checking if super class is already loaded
250 //
251 // We might not already have a placeholder if this child_name was
252 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
253 // the name of the class might not be known until the stream is actually
254 // parsed.
255 // Bugs 4643874, 4715493
256 // compute_hash can have a safepoint
257
258 unsigned int d_hash = dictionary()->compute_hash(child_name, class_loader);
259 int d_index = dictionary()->hash_to_index(d_hash);
260 unsigned int p_hash = placeholders()->compute_hash(child_name, class_loader);
261 int p_index = placeholders()->hash_to_index(p_hash);
262 // can't throw error holding a lock
263 bool child_already_loaded = false;
264 bool throw_circularity_error = false;
265 {
266 MutexLocker mu(SystemDictionary_lock, THREAD);
267 klassOop childk = find_class(d_index, d_hash, child_name, class_loader);
268 klassOop quicksuperk;
269 // to support // loading: if child done loading, just return superclass
270 // if class_name, & class_loader don't match:
271 // if initial define, SD update will give LinkageError
272 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
273 // so we don't throw an exception here.
274 // see: nsk redefclass014 & java.lang.instrument Instrument032
275 if ((childk != NULL ) && (is_superclass) &&
276 ((quicksuperk = instanceKlass::cast(childk)->super()) != NULL) &&
277
278 ((Klass::cast(quicksuperk)->name() == class_name()) &&
279 (Klass::cast(quicksuperk)->class_loader() == class_loader()))) {
280 return quicksuperk;
281 } else {
282 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, class_loader);
283 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
284 throw_circularity_error = true;
285 }
286
287 // add placeholder entry even if error - callers will remove on error
288 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, class_loader, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
289 if (throw_circularity_error) {
290 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER);
291 }
292 }
293 }
294 if (throw_circularity_error) {
295 ResourceMark rm(THREAD);
296 THROW_MSG_0(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
297 }
298
299 // java.lang.Object should have been found above
300 assert(class_name() != NULL, "null super class for resolving");
301 // Resolve the super class or interface, check results on return
302 klassOop superk = NULL;
303 superk = SystemDictionary::resolve_or_null(class_name,
304 class_loader,
305 protection_domain,
306 THREAD);
307
308 KlassHandle superk_h(THREAD, superk);
309
310 // Note: clean up of placeholders currently in callers of
311 // resolve_super_or_fail - either at update_dictionary time
312 // or on error
313 {
314 MutexLocker mu(SystemDictionary_lock, THREAD);
315 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, class_loader);
316 if (probe != NULL) {
317 probe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER);
318 }
319 }
320 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
321 // can null superk
322 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD));
323 }
324
325 return superk_h();
326 }
327
328
329 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
330 Handle class_loader,
331 Handle protection_domain,
332 TRAPS) {
333 if(!has_checkPackageAccess()) return;
334
335 // Now we have to call back to java to check if the initating class has access
336 JavaValue result(T_VOID);
337 if (TraceProtectionDomainVerification) {
338 // Print out trace information
339 tty->print_cr("Checking package access");
340 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr();
341 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr();
342 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr();
343 }
344
345 assert(class_loader() != NULL, "should not have non-null protection domain for null classloader");
346
347 KlassHandle system_loader(THREAD, SystemDictionary::classloader_klass());
348 JavaCalls::call_special(&result,
349 class_loader,
350 system_loader,
351 vmSymbolHandles::checkPackageAccess_name(),
352 vmSymbolHandles::class_protectiondomain_signature(),
353 Handle(THREAD, klass->java_mirror()),
354 protection_domain,
355 THREAD);
356
357 if (TraceProtectionDomainVerification) {
358 if (HAS_PENDING_EXCEPTION) {
359 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!");
360 } else {
361 tty->print_cr(" -> granted");
362 }
363 tty->cr();
364 }
365
366 if (HAS_PENDING_EXCEPTION) return;
367
368 // If no exception has been thrown, we have validated the protection domain
369 // Insert the protection domain of the initiating class into the set.
370 {
371 // We recalculate the entry here -- we've called out to java since
372 // the last time it was calculated.
373 symbolHandle kn(THREAD, klass->name());
374 unsigned int d_hash = dictionary()->compute_hash(kn, class_loader);
375 int d_index = dictionary()->hash_to_index(d_hash);
376
377 MutexLocker mu(SystemDictionary_lock, THREAD);
378 {
379 // Note that we have an entry, and entries can be deleted only during GC,
380 // so we cannot allow GC to occur while we're holding this entry.
381
382 // We're using a No_Safepoint_Verifier to catch any place where we
383 // might potentially do a GC at all.
384 // SystemDictionary::do_unloading() asserts that classes are only
385 // unloaded at a safepoint.
386 No_Safepoint_Verifier nosafepoint;
387 dictionary()->add_protection_domain(d_index, d_hash, klass, class_loader,
388 protection_domain, THREAD);
389 }
390 }
391 }
392
393 // We only get here if this thread finds that another thread
394 // has already claimed the placeholder token for the current operation,
395 // but that other thread either never owned or gave up the
396 // object lock
397 // Waits on SystemDictionary_lock to indicate placeholder table updated
398 // On return, caller must recheck placeholder table state
399 //
400 // We only get here if
401 // 1) custom classLoader, i.e. not bootstrap classloader
402 // 2) UnsyncloadClass not set
403 // 3) custom classLoader has broken the class loader objectLock
404 // so another thread got here in parallel
405 //
406 // lockObject must be held.
407 // Complicated dance due to lock ordering:
408 // Must first release the classloader object lock to
409 // allow initial definer to complete the class definition
410 // and to avoid deadlock
411 // Reclaim classloader lock object with same original recursion count
412 // Must release SystemDictionary_lock after notify, since
413 // class loader lock must be claimed before SystemDictionary_lock
414 // to prevent deadlocks
415 //
416 // The notify allows applications that did an untimed wait() on
417 // the classloader object lock to not hang.
418 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
419 assert_lock_strong(SystemDictionary_lock);
420
421 bool calledholdinglock
422 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
423 assert(calledholdinglock,"must hold lock for notify");
424 assert(!UnsyncloadClass, "unexpected double_lock_wait");
425 ObjectSynchronizer::notifyall(lockObject, THREAD);
426 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
427 SystemDictionary_lock->wait();
428 SystemDictionary_lock->unlock();
429 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
430 SystemDictionary_lock->lock();
431 }
432
433 // If the class in is in the placeholder table, class loading is in progress
434 // For cases where the application changes threads to load classes, it
435 // is critical to ClassCircularity detection that we try loading
436 // the superclass on the same thread internally, so we do parallel
437 // super class loading here.
438 // This also is critical in cases where the original thread gets stalled
439 // even in non-circularity situations.
440 // Note: only one thread can define the class, but multiple can resolve
441 // Note: must call resolve_super_or_fail even if null super -
442 // to force placeholder entry creation for this class
443 // Caller must check for pending exception
444 // Returns non-null klassOop if other thread has completed load
445 // and we are done,
446 // If return null klassOop and no pending exception, the caller must load the class
447 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
448 symbolHandle name, symbolHandle superclassname, Handle class_loader,
449 Handle protection_domain, Handle lockObject, TRAPS) {
450
451 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
452 unsigned int d_hash = dictionary()->compute_hash(name, class_loader);
453 int d_index = dictionary()->hash_to_index(d_hash);
454 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
455 int p_index = placeholders()->hash_to_index(p_hash);
456
457 // superk is not used, resolve_super called for circularity check only
458 // This code is reached in two situations. One if this thread
459 // is loading the same class twice (e.g. ClassCircularity, or
460 // java.lang.instrument).
461 // The second is if another thread started the resolve_super first
462 // and has not yet finished.
463 // In both cases the original caller will clean up the placeholder
464 // entry on error.
465 klassOop superk = SystemDictionary::resolve_super_or_fail(name,
466 superclassname,
467 class_loader,
468 protection_domain,
469 true,
470 CHECK_(nh));
471 // We don't redefine the class, so we just need to clean up if there
472 // was not an error (don't want to modify any system dictionary
473 // data structures).
474 {
475 MutexLocker mu(SystemDictionary_lock, THREAD);
476 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
477 SystemDictionary_lock->notify_all();
478 }
479
480 // UnsyncloadClass does NOT wait for parallel superclass loads to complete
481 // Bootstrap classloader does wait for parallel superclass loads
482 if (UnsyncloadClass) {
483 MutexLocker mu(SystemDictionary_lock, THREAD);
484 // Check if classloading completed while we were loading superclass or waiting
485 klassOop check = find_class(d_index, d_hash, name, class_loader);
486 if (check != NULL) {
487 // Klass is already loaded, so just return it
488 return(instanceKlassHandle(THREAD, check));
489 } else {
490 return nh;
491 }
492 }
493
494 // must loop to both handle other placeholder updates
495 // and spurious notifications
496 bool super_load_in_progress = true;
497 PlaceholderEntry* placeholder;
498 while (super_load_in_progress) {
499 MutexLocker mu(SystemDictionary_lock, THREAD);
500 // Check if classloading completed while we were loading superclass or waiting
501 klassOop check = find_class(d_index, d_hash, name, class_loader);
502 if (check != NULL) {
503 // Klass is already loaded, so just return it
504 return(instanceKlassHandle(THREAD, check));
505 } else {
506 placeholder = placeholders()->get_entry(p_index, p_hash, name, class_loader);
507 if (placeholder && placeholder->super_load_in_progress() ){
508 // Before UnsyncloadClass:
509 // We only get here if the application has released the
510 // classloader lock when another thread was in the middle of loading a
511 // superclass/superinterface for this class, and now
512 // this thread is also trying to load this class.
513 // To minimize surprises, the first thread that started to
514 // load a class should be the one to complete the loading
515 // with the classfile it initially expected.
516 // This logic has the current thread wait once it has done
517 // all the superclass/superinterface loading it can, until
518 // the original thread completes the class loading or fails
519 // If it completes we will use the resulting instanceKlass
520 // which we will find below in the systemDictionary.
521 // We also get here for parallel bootstrap classloader
522 if (class_loader.is_null()) {
523 SystemDictionary_lock->wait();
524 } else {
525 double_lock_wait(lockObject, THREAD);
526 }
527 } else {
528 // If not in SD and not in PH, other thread's load must have failed
529 super_load_in_progress = false;
530 }
531 }
532 }
533 return (nh);
534 }
535
536
537 klassOop SystemDictionary::resolve_instance_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS) {
538 assert(class_name.not_null() && !FieldType::is_array(class_name()), "invalid class name");
539 // First check to see if we should remove wrapping L and ;
540 symbolHandle name;
541 if (FieldType::is_obj(class_name())) {
542 ResourceMark rm(THREAD);
543 // Ignore wrapping L and ;.
544 name = oopFactory::new_symbol_handle(class_name()->as_C_string() + 1, class_name()->utf8_length() - 2, CHECK_NULL);
545 } else {
546 name = class_name;
547 }
548
549 // UseNewReflection
550 // Fix for 4474172; see evaluation for more details
551 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
552
553 // Do lookup to see if class already exist and the protection domain
554 // has the right access
555 unsigned int d_hash = dictionary()->compute_hash(name, class_loader);
556 int d_index = dictionary()->hash_to_index(d_hash);
557 klassOop probe = dictionary()->find(d_index, d_hash, name, class_loader,
558 protection_domain, THREAD);
559 if (probe != NULL) return probe;
560
561
562 // Non-bootstrap class loaders will call out to class loader and
563 // define via jvm/jni_DefineClass which will acquire the
564 // class loader object lock to protect against multiple threads
565 // defining the class in parallel by accident.
566 // This lock must be acquired here so the waiter will find
567 // any successful result in the SystemDictionary and not attempt
568 // the define
569 // Classloaders that support parallelism, e.g. bootstrap classloader,
570 // or all classloaders with UnsyncloadClass do not acquire lock here
571 bool DoObjectLock = true;
572 if (UnsyncloadClass || (class_loader.is_null())) {
573 DoObjectLock = false;
574 }
575
576 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
577 int p_index = placeholders()->hash_to_index(p_hash);
578
579 // Class is not in SystemDictionary so we have to do loading.
580 // Make sure we are synchronized on the class loader before we proceed
581 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
582 check_loader_lock_contention(lockObject, THREAD);
583 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
584
585 // Check again (after locking) if class already exist in SystemDictionary
586 bool class_has_been_loaded = false;
587 bool super_load_in_progress = false;
588 bool havesupername = false;
589 instanceKlassHandle k;
590 PlaceholderEntry* placeholder;
591 symbolHandle superclassname;
592
593 {
594 MutexLocker mu(SystemDictionary_lock, THREAD);
595 klassOop check = find_class(d_index, d_hash, name, class_loader);
596 if (check != NULL) {
597 // Klass is already loaded, so just return it
598 class_has_been_loaded = true;
599 k = instanceKlassHandle(THREAD, check);
600 } else {
601 placeholder = placeholders()->get_entry(p_index, p_hash, name, class_loader);
602 if (placeholder && placeholder->super_load_in_progress()) {
603 super_load_in_progress = true;
604 if (placeholder->havesupername() == true) {
605 superclassname = symbolHandle(THREAD, placeholder->supername());
606 havesupername = true;
607 }
608 }
609 }
610 }
611
612 // If the class in is in the placeholder table, class loading is in progress
613 if (super_load_in_progress && havesupername==true) {
614 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
615 class_loader, protection_domain, lockObject, THREAD);
616 if (HAS_PENDING_EXCEPTION) {
617 return NULL;
618 }
619 if (!k.is_null()) {
620 class_has_been_loaded = true;
621 }
622 }
623
624 if (!class_has_been_loaded) {
625
626 // add placeholder entry to record loading instance class
627 // Five cases:
628 // All cases need to prevent modifying bootclasssearchpath
629 // in parallel with a classload of same classname
630 // case 1. traditional classloaders that rely on the classloader object lock
631 // - no other need for LOAD_INSTANCE
632 // case 2. traditional classloaders that break the classloader object lock
633 // as a deadlock workaround. Detection of this case requires that
634 // this check is done while holding the classloader object lock,
635 // and that lock is still held when calling classloader's loadClass.
636 // For these classloaders, we ensure that the first requestor
637 // completes the load and other requestors wait for completion.
638 // case 3. UnsyncloadClass - don't use objectLocker
639 // With this flag, we allow parallel classloading of a
640 // class/classloader pair
641 // case4. Bootstrap classloader - don't own objectLocker
642 // This classloader supports parallelism at the classloader level,
643 // but only allows a single load of a class/classloader pair.
644 // No performance benefit and no deadlock issues.
645 // case 5. Future: parallel user level classloaders - without objectLocker
646 symbolHandle nullsymbolHandle;
647 bool throw_circularity_error = false;
648 {
649 MutexLocker mu(SystemDictionary_lock, THREAD);
650 if (!UnsyncloadClass) {
651 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
652 if (oldprobe) {
653 // only need check_seen_thread once, not on each loop
654 // 6341374 java/lang/Instrument with -Xcomp
655 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
656 throw_circularity_error = true;
657 } else {
658 // case 1: traditional: should never see load_in_progress.
659 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
660
661 // case 4: bootstrap classloader: prevent futile classloading,
662 // wait on first requestor
663 if (class_loader.is_null()) {
664 SystemDictionary_lock->wait();
665 } else {
666 // case 2: traditional with broken classloader lock. wait on first
667 // requestor.
668 double_lock_wait(lockObject, THREAD);
669 }
670 // Check if classloading completed while we were waiting
671 klassOop check = find_class(d_index, d_hash, name, class_loader);
672 if (check != NULL) {
673 // Klass is already loaded, so just return it
674 k = instanceKlassHandle(THREAD, check);
675 class_has_been_loaded = true;
676 }
677 // check if other thread failed to load and cleaned up
678 oldprobe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
679 }
680 }
681 }
682 }
683 // All cases: add LOAD_INSTANCE
684 // case 3: UnsyncloadClass: allow competing threads to try
685 // LOAD_INSTANCE in parallel
686 // add placeholder entry even if error - callers will remove on error
687 if (!class_has_been_loaded) {
688 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, class_loader, PlaceholderTable::LOAD_INSTANCE, nullsymbolHandle, THREAD);
689 if (throw_circularity_error) {
690 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
691 }
692 // For class loaders that do not acquire the classloader object lock,
693 // if they did not catch another thread holding LOAD_INSTANCE,
694 // need a check analogous to the acquire ObjectLocker/find_class
695 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
696 // one final check if the load has already completed
697 klassOop check = find_class(d_index, d_hash, name, class_loader);
698 if (check != NULL) {
699 // Klass is already loaded, so just return it
700 k = instanceKlassHandle(THREAD, check);
701 class_has_been_loaded = true;
702 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
703 }
704 }
705 }
706 // must throw error outside of owning lock
707 if (throw_circularity_error) {
708 ResourceMark rm(THREAD);
709 THROW_MSG_0(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
710 }
711
712 if (!class_has_been_loaded) {
713
714 // Do actual loading
715 k = load_instance_class(name, class_loader, THREAD);
716
717 // In custom class loaders, the usual findClass calls
718 // findLoadedClass, which directly searches the SystemDictionary, then
719 // defineClass. If these are not atomic with respect to other threads,
720 // the findLoadedClass can fail, but the defineClass can get a
721 // LinkageError:: duplicate class definition.
722 // If they got a linkageError, check if a parallel class load succeeded.
723 // If it did, then for bytecode resolution the specification requires
724 // that we return the same result we did for the other thread, i.e. the
725 // successfully loaded instanceKlass
726 // Note: Class can not be unloaded as long as any classloader refs exist
727 // Should not get here for classloaders that support parallelism
728 // with the new cleaner mechanism, e.g. bootstrap classloader
729 if (UnsyncloadClass || (class_loader.is_null())) {
730 if (k.is_null() && HAS_PENDING_EXCEPTION
731 && PENDING_EXCEPTION->is_a(SystemDictionary::linkageError_klass())) {
732 MutexLocker mu(SystemDictionary_lock, THREAD);
733 klassOop check = find_class(d_index, d_hash, name, class_loader);
734 if (check != NULL) {
735 // Klass is already loaded, so just use it
736 k = instanceKlassHandle(THREAD, check);
737 CLEAR_PENDING_EXCEPTION;
738 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
739 }
740 }
741 }
742
743 // clean up placeholder entries for success or error
744 // This cleans up LOAD_INSTANCE entries
745 // It also cleans up LOAD_SUPER entries on errors from
746 // calling load_instance_class
747 {
748 MutexLocker mu(SystemDictionary_lock, THREAD);
749 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
750 if (probe != NULL) {
751 probe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
752 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
753 SystemDictionary_lock->notify_all();
754 }
755 }
756
757 // If everything was OK (no exceptions, no null return value), and
758 // class_loader is NOT the defining loader, do a little more bookkeeping.
759 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
760 k->class_loader() != class_loader()) {
761
762 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
763
764 // Need to check for a PENDING_EXCEPTION again; check_constraints
765 // can throw and doesn't use the CHECK macro.
766 if (!HAS_PENDING_EXCEPTION) {
767 { // Grabbing the Compile_lock prevents systemDictionary updates
768 // during compilations.
769 MutexLocker mu(Compile_lock, THREAD);
770 update_dictionary(d_index, d_hash, p_index, p_hash,
771 k, class_loader, THREAD);
772 }
773 if (JvmtiExport::should_post_class_load()) {
774 Thread *thread = THREAD;
775 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
776 JvmtiExport::post_class_load((JavaThread *) thread, k());
777 }
778 }
779 }
780 if (HAS_PENDING_EXCEPTION || k.is_null()) {
781 // On error, clean up placeholders
782 {
783 MutexLocker mu(SystemDictionary_lock, THREAD);
784 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
785 SystemDictionary_lock->notify_all();
786 }
787 return NULL;
788 }
789 }
790 }
791
792 #ifdef ASSERT
793 {
794 Handle loader (THREAD, k->class_loader());
795 MutexLocker mu(SystemDictionary_lock, THREAD);
796 oop kk = find_class_or_placeholder(name, loader);
797 assert(kk == k(), "should be present in dictionary");
798 }
799 #endif
800
801 // return if the protection domain in NULL
802 if (protection_domain() == NULL) return k();
803
804 // Check the protection domain has the right access
805 {
806 MutexLocker mu(SystemDictionary_lock, THREAD);
807 // Note that we have an entry, and entries can be deleted only during GC,
808 // so we cannot allow GC to occur while we're holding this entry.
809 // We're using a No_Safepoint_Verifier to catch any place where we
810 // might potentially do a GC at all.
811 // SystemDictionary::do_unloading() asserts that classes are only
812 // unloaded at a safepoint.
813 No_Safepoint_Verifier nosafepoint;
814 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
815 class_loader,
816 protection_domain)) {
817 return k();
818 }
819 }
820
821 // Verify protection domain. If it fails an exception is thrown
822 validate_protection_domain(k, class_loader, protection_domain, CHECK_(klassOop(NULL)));
823
824 return k();
825 }
826
827
828 // This routine does not lock the system dictionary.
829 //
830 // Since readers don't hold a lock, we must make sure that system
831 // dictionary entries are only removed at a safepoint (when only one
832 // thread is running), and are added to in a safe way (all links must
833 // be updated in an MT-safe manner).
834 //
835 // Callers should be aware that an entry could be added just after
836 // _dictionary->bucket(index) is read here, so the caller will not see
837 // the new entry.
838
839 klassOop SystemDictionary::find(symbolHandle class_name,
840 Handle class_loader,
841 Handle protection_domain,
842 TRAPS) {
843
844 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
845 int d_index = dictionary()->hash_to_index(d_hash);
846
847 {
848 // Note that we have an entry, and entries can be deleted only during GC,
849 // so we cannot allow GC to occur while we're holding this entry.
850 // We're using a No_Safepoint_Verifier to catch any place where we
851 // might potentially do a GC at all.
852 // SystemDictionary::do_unloading() asserts that classes are only
853 // unloaded at a safepoint.
854 No_Safepoint_Verifier nosafepoint;
855 return dictionary()->find(d_index, d_hash, class_name, class_loader,
856 protection_domain, THREAD);
857 }
858 }
859
860
861 // Look for a loaded instance or array klass by name. Do not do any loading.
862 // return NULL in case of error.
863 klassOop SystemDictionary::find_instance_or_array_klass(symbolHandle class_name,
864 Handle class_loader,
865 Handle protection_domain,
866 TRAPS) {
867 klassOop k = NULL;
868 assert(class_name() != NULL, "class name must be non NULL");
869
870 // Try to get one of the well-known klasses.
871 if (LinkWellKnownClasses) {
872 k = find_well_known_klass(class_name());
873 if (k != NULL) {
874 return k;
875 }
876 }
877
878 if (FieldType::is_array(class_name())) {
879 // The name refers to an array. Parse the name.
880 jint dimension;
881 symbolOop object_key;
882
883 // dimension and object_key are assigned as a side-effect of this call
884 BasicType t = FieldType::get_array_info(class_name(), &dimension,
885 &object_key, CHECK_(NULL));
886 if (t != T_OBJECT) {
887 k = Universe::typeArrayKlassObj(t);
888 } else {
889 symbolHandle h_key(THREAD, object_key);
890 k = SystemDictionary::find(h_key, class_loader, protection_domain, THREAD);
891 }
892 if (k != NULL) {
893 k = Klass::cast(k)->array_klass_or_null(dimension);
894 }
895 } else {
896 k = find(class_name, class_loader, protection_domain, THREAD);
897 }
898 return k;
899 }
900
901 // Quick range check for names of well-known classes:
902 static symbolOop wk_klass_name_limits[2] = {NULL, NULL};
903
904 #ifndef PRODUCT
905 static int find_wkk_calls, find_wkk_probes, find_wkk_wins;
906 // counts for "hello world": 3983, 1616, 1075
907 // => 60% hit after limit guard, 25% total win rate
908 #endif
909
910 klassOop SystemDictionary::find_well_known_klass(symbolOop class_name) {
911 // A bounds-check on class_name will quickly get a negative result.
912 NOT_PRODUCT(find_wkk_calls++);
913 if (class_name >= wk_klass_name_limits[0] &&
914 class_name <= wk_klass_name_limits[1]) {
915 NOT_PRODUCT(find_wkk_probes++);
916 vmSymbols::SID sid = vmSymbols::find_sid(class_name);
917 if (sid != vmSymbols::NO_SID) {
918 klassOop k = NULL;
919 switch (sid) {
920 #define WK_KLASS_CASE(name, symbol, ignore_option) \
921 case vmSymbols::VM_SYMBOL_ENUM_NAME(symbol): \
922 k = WK_KLASS(name); break;
923 WK_KLASSES_DO(WK_KLASS_CASE)
924 #undef WK_KLASS_CASE
925 }
926 NOT_PRODUCT(if (k != NULL) find_wkk_wins++);
927 return k;
928 }
929 }
930 return NULL;
931 }
932
933 // Note: this method is much like resolve_from_stream, but
934 // updates no supplemental data structures.
935 // TODO consolidate the two methods with a helper routine?
936 klassOop SystemDictionary::parse_stream(symbolHandle class_name,
937 Handle class_loader,
938 Handle protection_domain,
939 ClassFileStream* st,
940 TRAPS) {
941 symbolHandle parsed_name;
942
943 // Parse the stream. Note that we do this even though this klass might
944 // already be present in the SystemDictionary, otherwise we would not
945 // throw potential ClassFormatErrors.
946 //
947 // Note: "name" is updated.
948 // Further note: a placeholder will be added for this class when
949 // super classes are loaded (resolve_super_or_fail). We expect this
950 // to be called for all classes but java.lang.Object; and we preload
951 // java.lang.Object through resolve_or_fail, not this path.
952
953 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
954 class_loader,
955 protection_domain,
956 parsed_name,
957 THREAD);
958
959
960 // We don't redefine the class, so we just need to clean up whether there
961 // was an error or not (don't want to modify any system dictionary
962 // data structures).
963 // Parsed name could be null if we threw an error before we got far
964 // enough along to parse it -- in that case, there is nothing to clean up.
965 if (!parsed_name.is_null()) {
966 unsigned int p_hash = placeholders()->compute_hash(parsed_name,
967 class_loader);
968 int p_index = placeholders()->hash_to_index(p_hash);
969 {
970 MutexLocker mu(SystemDictionary_lock, THREAD);
971 placeholders()->find_and_remove(p_index, p_hash, parsed_name, class_loader, THREAD);
972 SystemDictionary_lock->notify_all();
973 }
974 }
975
976 return k();
977 }
978
979 // Add a klass to the system from a stream (called by jni_DefineClass and
980 // JVM_DefineClass).
981 // Note: class_name can be NULL. In that case we do not know the name of
982 // the class until we have parsed the stream.
983
984 klassOop SystemDictionary::resolve_from_stream(symbolHandle class_name,
985 Handle class_loader,
986 Handle protection_domain,
987 ClassFileStream* st,
988 TRAPS) {
989
990 // Make sure we are synchronized on the class loader before we initiate
991 // loading.
992 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
993 check_loader_lock_contention(lockObject, THREAD);
994 ObjectLocker ol(lockObject, THREAD);
995
996 symbolHandle parsed_name;
997
998 // Parse the stream. Note that we do this even though this klass might
999 // already be present in the SystemDictionary, otherwise we would not
1000 // throw potential ClassFormatErrors.
1001 //
1002 // Note: "name" is updated.
1003 // Further note: a placeholder will be added for this class when
1004 // super classes are loaded (resolve_super_or_fail). We expect this
1005 // to be called for all classes but java.lang.Object; and we preload
1006 // java.lang.Object through resolve_or_fail, not this path.
1007
1008 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
1009 class_loader,
1010 protection_domain,
1011 parsed_name,
1012 THREAD);
1013
1014 const char* pkg = "java/";
1015 if (!HAS_PENDING_EXCEPTION &&
1016 !class_loader.is_null() &&
1017 !parsed_name.is_null() &&
1018 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
1019 // It is illegal to define classes in the "java." package from
1020 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
1021 ResourceMark rm(THREAD);
1022 char* name = parsed_name->as_C_string();
1023 char* index = strrchr(name, '/');
1024 *index = '\0'; // chop to just the package name
1025 while ((index = strchr(name, '/')) != NULL) {
1026 *index = '.'; // replace '/' with '.' in package name
1027 }
1028 const char* fmt = "Prohibited package name: %s";
1029 size_t len = strlen(fmt) + strlen(name);
1030 char* message = NEW_RESOURCE_ARRAY(char, len);
1031 jio_snprintf(message, len, fmt, name);
1032 Exceptions::_throw_msg(THREAD_AND_LOCATION,
1033 vmSymbols::java_lang_SecurityException(), message);
1034 }
1035
1036 if (!HAS_PENDING_EXCEPTION) {
1037 assert(!parsed_name.is_null(), "Sanity");
1038 assert(class_name.is_null() || class_name() == parsed_name(),
1039 "name mismatch");
1040 // Verification prevents us from creating names with dots in them, this
1041 // asserts that that's the case.
1042 assert(is_internal_format(parsed_name),
1043 "external class name format used internally");
1044
1045 // Add class just loaded
1046 define_instance_class(k, THREAD);
1047 }
1048
1049 // If parsing the class file or define_instance_class failed, we
1050 // need to remove the placeholder added on our behalf. But we
1051 // must make sure parsed_name is valid first (it won't be if we had
1052 // a format error before the class was parsed far enough to
1053 // find the name).
1054 if (HAS_PENDING_EXCEPTION && !parsed_name.is_null()) {
1055 unsigned int p_hash = placeholders()->compute_hash(parsed_name,
1056 class_loader);
1057 int p_index = placeholders()->hash_to_index(p_hash);
1058 {
1059 MutexLocker mu(SystemDictionary_lock, THREAD);
1060 placeholders()->find_and_remove(p_index, p_hash, parsed_name, class_loader, THREAD);
1061 SystemDictionary_lock->notify_all();
1062 }
1063 return NULL;
1064 }
1065
1066 // Make sure that we didn't leave a place holder in the
1067 // SystemDictionary; this is only done on success
1068 debug_only( {
1069 if (!HAS_PENDING_EXCEPTION) {
1070 assert(!parsed_name.is_null(), "parsed_name is still null?");
1071 symbolHandle h_name (THREAD, k->name());
1072 Handle h_loader (THREAD, k->class_loader());
1073
1074 MutexLocker mu(SystemDictionary_lock, THREAD);
1075
1076 oop check = find_class_or_placeholder(parsed_name, class_loader);
1077 assert(check == k(), "should be present in the dictionary");
1078
1079 oop check2 = find_class_or_placeholder(h_name, h_loader);
1080 assert(check == check2, "name inconsistancy in SystemDictionary");
1081 }
1082 } );
1083
1084 return k();
1085 }
1086
1087
1088 void SystemDictionary::set_shared_dictionary(HashtableBucket* t, int length,
1089 int number_of_entries) {
1090 assert(length == _nof_buckets * sizeof(HashtableBucket),
1091 "bad shared dictionary size.");
1092 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1093 }
1094
1095
1096 // If there is a shared dictionary, then find the entry for the
1097 // given shared system class, if any.
1098
1099 klassOop SystemDictionary::find_shared_class(symbolHandle class_name) {
1100 if (shared_dictionary() != NULL) {
1101 unsigned int d_hash = dictionary()->compute_hash(class_name, Handle());
1102 int d_index = dictionary()->hash_to_index(d_hash);
1103 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1104 } else {
1105 return NULL;
1106 }
1107 }
1108
1109
1110 // Load a class from the shared spaces (found through the shared system
1111 // dictionary). Force the superclass and all interfaces to be loaded.
1112 // Update the class definition to include sibling classes and no
1113 // subclasses (yet). [Classes in the shared space are not part of the
1114 // object hierarchy until loaded.]
1115
1116 instanceKlassHandle SystemDictionary::load_shared_class(
1117 symbolHandle class_name, Handle class_loader, TRAPS) {
1118 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
1119 return load_shared_class(ik, class_loader, THREAD);
1120 }
1121
1122 // Note well! Changes to this method may affect oop access order
1123 // in the shared archive. Please take care to not make changes that
1124 // adversely affect cold start time by changing the oop access order
1125 // that is specified in dump.cpp MarkAndMoveOrderedReadOnly and
1126 // MarkAndMoveOrderedReadWrite closures.
1127 instanceKlassHandle SystemDictionary::load_shared_class(
1128 instanceKlassHandle ik, Handle class_loader, TRAPS) {
1129 assert(class_loader.is_null(), "non-null classloader for shared class?");
1130 if (ik.not_null()) {
1131 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1132 symbolHandle class_name(THREAD, ik->name());
1133
1134 // Found the class, now load the superclass and interfaces. If they
1135 // are shared, add them to the main system dictionary and reset
1136 // their hierarchy references (supers, subs, and interfaces).
1137
1138 if (ik->super() != NULL) {
1139 symbolHandle cn(THREAD, ik->super()->klass_part()->name());
1140 resolve_super_or_fail(class_name, cn,
1141 class_loader, Handle(), true, CHECK_(nh));
1142 }
1143
1144 objArrayHandle interfaces (THREAD, ik->local_interfaces());
1145 int num_interfaces = interfaces->length();
1146 for (int index = 0; index < num_interfaces; index++) {
1147 klassOop k = klassOop(interfaces->obj_at(index));
1148
1149 // Note: can not use instanceKlass::cast here because
1150 // interfaces' instanceKlass's C++ vtbls haven't been
1151 // reinitialized yet (they will be once the interface classes
1152 // are loaded)
1153 symbolHandle name (THREAD, k->klass_part()->name());
1154 resolve_super_or_fail(class_name, name, class_loader, Handle(), false, CHECK_(nh));
1155 }
1156
1157 // Adjust methods to recover missing data. They need addresses for
1158 // interpreter entry points and their default native method address
1159 // must be reset.
1160
1161 // Updating methods must be done under a lock so multiple
1162 // threads don't update these in parallel
1163 // Shared classes are all currently loaded by the bootstrap
1164 // classloader, so this will never cause a deadlock on
1165 // a custom class loader lock.
1166
1167 {
1168 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1169 check_loader_lock_contention(lockObject, THREAD);
1170 ObjectLocker ol(lockObject, THREAD, true);
1171
1172 objArrayHandle methods (THREAD, ik->methods());
1173 int num_methods = methods->length();
1174 for (int index2 = 0; index2 < num_methods; ++index2) {
1175 methodHandle m(THREAD, methodOop(methods->obj_at(index2)));
1176 m()->link_method(m, CHECK_(nh));
1177 }
1178 }
1179
1180 if (TraceClassLoading) {
1181 ResourceMark rm;
1182 tty->print("[Loaded %s", ik->external_name());
1183 tty->print(" from shared objects file");
1184 tty->print_cr("]");
1185 }
1186 // notify a class loaded from shared object
1187 ClassLoadingService::notify_class_loaded(instanceKlass::cast(ik()),
1188 true /* shared class */);
1189 }
1190 return ik;
1191 }
1192
1193 #ifdef KERNEL
1194 // Some classes on the bootstrap class path haven't been installed on the
1195 // system yet. Call the DownloadManager method to make them appear in the
1196 // bootstrap class path and try again to load the named class.
1197 // Note that with delegation class loaders all classes in another loader will
1198 // first try to call this so it'd better be fast!!
1199 static instanceKlassHandle download_and_retry_class_load(
1200 symbolHandle class_name,
1201 TRAPS) {
1202
1203 klassOop dlm = SystemDictionary::sun_jkernel_DownloadManager_klass();
1204 instanceKlassHandle nk;
1205
1206 // If download manager class isn't loaded just return.
1207 if (dlm == NULL) return nk;
1208
1209 { HandleMark hm(THREAD);
1210 ResourceMark rm(THREAD);
1211 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nk));
1212 Handle class_string = java_lang_String::externalize_classname(s, CHECK_(nk));
1213
1214 // return value
1215 JavaValue result(T_OBJECT);
1216
1217 // Call the DownloadManager. We assume that it has a lock because
1218 // multiple classes could be not found and downloaded at the same time.
1219 // class sun.misc.DownloadManager;
1220 // public static String getBootClassPathEntryForClass(String className);
1221 JavaCalls::call_static(&result,
1222 KlassHandle(THREAD, dlm),
1223 vmSymbolHandles::getBootClassPathEntryForClass_name(),
1224 vmSymbolHandles::string_string_signature(),
1225 class_string,
1226 CHECK_(nk));
1227
1228 // Get result.string and add to bootclasspath
1229 assert(result.get_type() == T_OBJECT, "just checking");
1230 oop obj = (oop) result.get_jobject();
1231 if (obj == NULL) { return nk; }
1232
1233 Handle h_obj(THREAD, obj);
1234 char* new_class_name = java_lang_String::as_platform_dependent_str(h_obj,
1235 CHECK_(nk));
1236
1237 // lock the loader
1238 // we use this lock because JVMTI does.
1239 Handle loader_lock(THREAD, SystemDictionary::system_loader_lock());
1240
1241 ObjectLocker ol(loader_lock, THREAD);
1242 // add the file to the bootclasspath
1243 ClassLoader::update_class_path_entry_list(new_class_name, true);
1244 } // end HandleMark
1245
1246 if (TraceClassLoading) {
1247 ClassLoader::print_bootclasspath();
1248 }
1249 return ClassLoader::load_classfile(class_name, CHECK_(nk));
1250 }
1251 #endif // KERNEL
1252
1253
1254 instanceKlassHandle SystemDictionary::load_instance_class(symbolHandle class_name, Handle class_loader, TRAPS) {
1255 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1256 if (class_loader.is_null()) {
1257 // Search the shared system dictionary for classes preloaded into the
1258 // shared spaces.
1259 instanceKlassHandle k;
1260 k = load_shared_class(class_name, class_loader, THREAD);
1261
1262 if (k.is_null()) {
1263 // Use VM class loader
1264 k = ClassLoader::load_classfile(class_name, CHECK_(nh));
1265 }
1266
1267 #ifdef KERNEL
1268 // If the VM class loader has failed to load the class, call the
1269 // DownloadManager class to make it magically appear on the classpath
1270 // and try again. This is only configured with the Kernel VM.
1271 if (k.is_null()) {
1272 k = download_and_retry_class_load(class_name, CHECK_(nh));
1273 }
1274 #endif // KERNEL
1275
1276 // find_or_define_instance_class may return a different k
1277 if (!k.is_null()) {
1278 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
1279 }
1280 return k;
1281 } else {
1282 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1283 ResourceMark rm(THREAD);
1284
1285 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
1286 // Translate to external class name format, i.e., convert '/' chars to '.'
1287 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
1288
1289 JavaValue result(T_OBJECT);
1290
1291 KlassHandle spec_klass (THREAD, SystemDictionary::classloader_klass());
1292
1293 // UnsyncloadClass option means don't synchronize loadClass() calls.
1294 // loadClassInternal() is synchronized and public loadClass(String) is not.
1295 // This flag is for diagnostic purposes only. It is risky to call
1296 // custom class loaders without synchronization.
1297 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1298 // findClass, this flag risks unexpected timing bugs in the field.
1299 // Do NOT assume this will be supported in future releases.
1300 if (!UnsyncloadClass && has_loadClassInternal()) {
1301 JavaCalls::call_special(&result,
1302 class_loader,
1303 spec_klass,
1304 vmSymbolHandles::loadClassInternal_name(),
1305 vmSymbolHandles::string_class_signature(),
1306 string,
1307 CHECK_(nh));
1308 } else {
1309 JavaCalls::call_virtual(&result,
1310 class_loader,
1311 spec_klass,
1312 vmSymbolHandles::loadClass_name(),
1313 vmSymbolHandles::string_class_signature(),
1314 string,
1315 CHECK_(nh));
1316 }
1317
1318 assert(result.get_type() == T_OBJECT, "just checking");
1319 oop obj = (oop) result.get_jobject();
1320
1321 // Primitive classes return null since forName() can not be
1322 // used to obtain any of the Class objects representing primitives or void
1323 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1324 instanceKlassHandle k =
1325 instanceKlassHandle(THREAD, java_lang_Class::as_klassOop(obj));
1326 // For user defined Java class loaders, check that the name returned is
1327 // the same as that requested. This check is done for the bootstrap
1328 // loader when parsing the class file.
1329 if (class_name() == k->name()) {
1330 return k;
1331 }
1332 }
1333 // Class is not found or has the wrong name, return NULL
1334 return nh;
1335 }
1336 }
1337
1338 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
1339
1340 Handle class_loader_h(THREAD, k->class_loader());
1341
1342 // for bootstrap classloader don't acquire lock
1343 if (!class_loader_h.is_null()) {
1344 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1345 compute_loader_lock_object(class_loader_h, THREAD)),
1346 "define called without lock");
1347 }
1348
1349
1350 // Check class-loading constraints. Throw exception if violation is detected.
1351 // Grabs and releases SystemDictionary_lock
1352 // The check_constraints/find_class call and update_dictionary sequence
1353 // must be "atomic" for a specific class/classloader pair so we never
1354 // define two different instanceKlasses for that class/classloader pair.
1355 // Existing classloaders will call define_instance_class with the
1356 // classloader lock held
1357 // Parallel classloaders will call find_or_define_instance_class
1358 // which will require a token to perform the define class
1359 symbolHandle name_h(THREAD, k->name());
1360 unsigned int d_hash = dictionary()->compute_hash(name_h, class_loader_h);
1361 int d_index = dictionary()->hash_to_index(d_hash);
1362 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1363
1364 // Register class just loaded with class loader (placed in Vector)
1365 // Note we do this before updating the dictionary, as this can
1366 // fail with an OutOfMemoryError (if it does, we will *not* put this
1367 // class in the dictionary and will not update the class hierarchy).
1368 if (k->class_loader() != NULL) {
1369 methodHandle m(THREAD, Universe::loader_addClass_method());
1370 JavaValue result(T_VOID);
1371 JavaCallArguments args(class_loader_h);
1372 args.push_oop(Handle(THREAD, k->java_mirror()));
1373 JavaCalls::call(&result, m, &args, CHECK);
1374 }
1375
1376 // Add the new class. We need recompile lock during update of CHA.
1377 {
1378 unsigned int p_hash = placeholders()->compute_hash(name_h, class_loader_h);
1379 int p_index = placeholders()->hash_to_index(p_hash);
1380
1381 MutexLocker mu_r(Compile_lock, THREAD);
1382
1383 // Add to class hierarchy, initialize vtables, and do possible
1384 // deoptimizations.
1385 add_to_hierarchy(k, CHECK); // No exception, but can block
1386
1387 // Add to systemDictionary - so other classes can see it.
1388 // Grabs and releases SystemDictionary_lock
1389 update_dictionary(d_index, d_hash, p_index, p_hash,
1390 k, class_loader_h, THREAD);
1391 }
1392 k->eager_initialize(THREAD);
1393
1394 // notify jvmti
1395 if (JvmtiExport::should_post_class_load()) {
1396 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1397 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1398
1399 }
1400 }
1401
1402 // Support parallel classloading
1403 // Initial implementation for bootstrap classloader
1404 // For future:
1405 // For custom class loaders that support parallel classloading,
1406 // in case they do not synchronize around
1407 // FindLoadedClass/DefineClass calls, we check for parallel
1408 // loading for them, wait if a defineClass is in progress
1409 // and return the initial requestor's results
1410 // For better performance, the class loaders should synchronize
1411 // findClass(), i.e. FindLoadedClass/DefineClass or they
1412 // potentially waste time reading and parsing the bytestream.
1413 // Note: VM callers should ensure consistency of k/class_name,class_loader
1414 instanceKlassHandle SystemDictionary::find_or_define_instance_class(symbolHandle class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
1415
1416 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1417
1418 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
1419 int d_index = dictionary()->hash_to_index(d_hash);
1420
1421 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1422 unsigned int p_hash = placeholders()->compute_hash(class_name, class_loader);
1423 int p_index = placeholders()->hash_to_index(p_hash);
1424 PlaceholderEntry* probe;
1425
1426 {
1427 MutexLocker mu(SystemDictionary_lock, THREAD);
1428 // First check if class already defined
1429 klassOop check = find_class(d_index, d_hash, class_name, class_loader);
1430 if (check != NULL) {
1431 return(instanceKlassHandle(THREAD, check));
1432 }
1433
1434 // Acquire define token for this class/classloader
1435 symbolHandle nullsymbolHandle;
1436 probe = placeholders()->find_and_add(p_index, p_hash, class_name, class_loader, PlaceholderTable::DEFINE_CLASS, nullsymbolHandle, THREAD);
1437 // Check if another thread defining in parallel
1438 if (probe->definer() == NULL) {
1439 // Thread will define the class
1440 probe->set_definer(THREAD);
1441 } else {
1442 // Wait for defining thread to finish and return results
1443 while (probe->definer() != NULL) {
1444 SystemDictionary_lock->wait();
1445 }
1446 if (probe->instanceKlass() != NULL) {
1447 probe->remove_seen_thread(THREAD, PlaceholderTable::DEFINE_CLASS);
1448 return(instanceKlassHandle(THREAD, probe->instanceKlass()));
1449 } else {
1450 // If definer had an error, try again as any new thread would
1451 probe->set_definer(THREAD);
1452 #ifdef ASSERT
1453 klassOop check = find_class(d_index, d_hash, class_name, class_loader);
1454 assert(check == NULL, "definer missed recording success");
1455 #endif
1456 }
1457 }
1458 }
1459
1460 define_instance_class(k, THREAD);
1461
1462 Handle linkage_exception = Handle(); // null handle
1463
1464 // definer must notify any waiting threads
1465 {
1466 MutexLocker mu(SystemDictionary_lock, THREAD);
1467 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, class_name, class_loader);
1468 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1469 if (probe != NULL) {
1470 if (HAS_PENDING_EXCEPTION) {
1471 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1472 CLEAR_PENDING_EXCEPTION;
1473 } else {
1474 probe->set_instanceKlass(k());
1475 }
1476 probe->set_definer(NULL);
1477 probe->remove_seen_thread(THREAD, PlaceholderTable::DEFINE_CLASS);
1478 SystemDictionary_lock->notify_all();
1479 }
1480 }
1481
1482 // Can't throw exception while holding lock due to rank ordering
1483 if (linkage_exception() != NULL) {
1484 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
1485 }
1486
1487 return k;
1488 }
1489
1490 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1491 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1492 if (class_loader.is_null()) {
1493 return Handle(THREAD, _system_loader_lock_obj);
1494 } else {
1495 return class_loader;
1496 }
1497 }
1498
1499 // This method is added to check how often we have to wait to grab loader
1500 // lock. The results are being recorded in the performance counters defined in
1501 // ClassLoader::_sync_systemLoaderLockContentionRate and
1502 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1503 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1504 if (!UsePerfData) {
1505 return;
1506 }
1507
1508 assert(!loader_lock.is_null(), "NULL lock object");
1509
1510 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1511 == ObjectSynchronizer::owner_other) {
1512 // contention will likely happen, so increment the corresponding
1513 // contention counter.
1514 if (loader_lock() == _system_loader_lock_obj) {
1515 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1516 } else {
1517 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1518 }
1519 }
1520 }
1521
1522 // ----------------------------------------------------------------------------
1523 // Lookup
1524
1525 klassOop SystemDictionary::find_class(int index, unsigned int hash,
1526 symbolHandle class_name,
1527 Handle class_loader) {
1528 assert_locked_or_safepoint(SystemDictionary_lock);
1529 assert (index == dictionary()->index_for(class_name, class_loader),
1530 "incorrect index?");
1531
1532 klassOop k = dictionary()->find_class(index, hash, class_name, class_loader);
1533 return k;
1534 }
1535
1536
1537 // Basic find on classes in the midst of being loaded
1538 symbolOop SystemDictionary::find_placeholder(int index, unsigned int hash,
1539 symbolHandle class_name,
1540 Handle class_loader) {
1541 assert_locked_or_safepoint(SystemDictionary_lock);
1542
1543 return placeholders()->find_entry(index, hash, class_name, class_loader);
1544 }
1545
1546
1547 // Used for assertions and verification only
1548 oop SystemDictionary::find_class_or_placeholder(symbolHandle class_name,
1549 Handle class_loader) {
1550 #ifndef ASSERT
1551 guarantee(VerifyBeforeGC ||
1552 VerifyDuringGC ||
1553 VerifyBeforeExit ||
1554 VerifyAfterGC, "too expensive");
1555 #endif
1556 assert_locked_or_safepoint(SystemDictionary_lock);
1557 symbolOop class_name_ = class_name();
1558 oop class_loader_ = class_loader();
1559
1560 // First look in the loaded class array
1561 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
1562 int d_index = dictionary()->hash_to_index(d_hash);
1563 oop lookup = find_class(d_index, d_hash, class_name, class_loader);
1564
1565 if (lookup == NULL) {
1566 // Next try the placeholders
1567 unsigned int p_hash = placeholders()->compute_hash(class_name,class_loader);
1568 int p_index = placeholders()->hash_to_index(p_hash);
1569 lookup = find_placeholder(p_index, p_hash, class_name, class_loader);
1570 }
1571
1572 return lookup;
1573 }
1574
1575
1576 // Get the next class in the diictionary.
1577 klassOop SystemDictionary::try_get_next_class() {
1578 return dictionary()->try_get_next_class();
1579 }
1580
1581
1582 // ----------------------------------------------------------------------------
1583 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1584 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1585 // before a new class is used.
1586
1587 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
1588 assert(k.not_null(), "just checking");
1589 // Link into hierachy. Make sure the vtables are initialized before linking into
1590 k->append_to_sibling_list(); // add to superklass/sibling list
1591 k->process_interfaces(THREAD); // handle all "implements" declarations
1592 k->set_init_state(instanceKlass::loaded);
1593 // Now flush all code that depended on old class hierarchy.
1594 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1595 // Also, first reinitialize vtable because it may have gotten out of synch
1596 // while the new class wasn't connected to the class hierarchy.
1597 Universe::flush_dependents_on(k);
1598 }
1599
1600
1601 // ----------------------------------------------------------------------------
1602 // GC support
1603
1604 // Following roots during mark-sweep is separated in two phases.
1605 //
1606 // The first phase follows preloaded classes and all other system
1607 // classes, since these will never get unloaded anyway.
1608 //
1609 // The second phase removes (unloads) unreachable classes from the
1610 // system dictionary and follows the remaining classes' contents.
1611
1612 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1613 // Follow preloaded classes/mirrors and system loader object
1614 blk->do_oop(&_java_system_loader);
1615 preloaded_oops_do(blk);
1616 always_strong_classes_do(blk);
1617 }
1618
1619
1620 void SystemDictionary::always_strong_classes_do(OopClosure* blk) {
1621 // Follow all system classes and temporary placeholders in dictionary
1622 dictionary()->always_strong_classes_do(blk);
1623
1624 // Placeholders. These are *always* strong roots, as they
1625 // represent classes we're actively loading.
1626 placeholders_do(blk);
1627
1628 // Loader constraints. We must keep the symbolOop used in the name alive.
1629 constraints()->always_strong_classes_do(blk);
1630
1631 // Resolution errors keep the symbolOop for the error alive
1632 resolution_errors()->always_strong_classes_do(blk);
1633 }
1634
1635
1636 void SystemDictionary::placeholders_do(OopClosure* blk) {
1637 placeholders()->oops_do(blk);
1638 }
1639
1640
1641 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
1642 bool result = dictionary()->do_unloading(is_alive);
1643 constraints()->purge_loader_constraints(is_alive);
1644 resolution_errors()->purge_resolution_errors(is_alive);
1645 return result;
1646 }
1647
1648
1649 // The mirrors are scanned by shared_oops_do() which is
1650 // not called by oops_do(). In order to process oops in
1651 // a necessary order, shared_oops_do() is call by
1652 // Universe::oops_do().
1653 void SystemDictionary::oops_do(OopClosure* f) {
1654 // Adjust preloaded classes and system loader object
1655 f->do_oop(&_java_system_loader);
1656 preloaded_oops_do(f);
1657
1658 lazily_loaded_oops_do(f);
1659
1660 // Adjust dictionary
1661 dictionary()->oops_do(f);
1662
1663 // Partially loaded classes
1664 placeholders()->oops_do(f);
1665
1666 // Adjust constraint table
1667 constraints()->oops_do(f);
1668
1669 // Adjust resolution error table
1670 resolution_errors()->oops_do(f);
1671 }
1672
1673
1674 void SystemDictionary::preloaded_oops_do(OopClosure* f) {
1675 f->do_oop((oop*) &wk_klass_name_limits[0]);
1676 f->do_oop((oop*) &wk_klass_name_limits[1]);
1677
1678 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
1679 f->do_oop((oop*) &_well_known_klasses[k]);
1680 }
1681
1682 {
1683 for (int i = 0; i < T_VOID+1; i++) {
1684 if (_box_klasses[i] != NULL) {
1685 assert(i >= T_BOOLEAN, "checking");
1686 f->do_oop((oop*) &_box_klasses[i]);
1687 }
1688 }
1689 }
1690
1691 // The basic type mirrors would have already been processed in
1692 // Universe::oops_do(), via a call to shared_oops_do(), so should
1693 // not be processed again.
1694
1695 f->do_oop((oop*) &_system_loader_lock_obj);
1696 FilteredFieldsMap::klasses_oops_do(f);
1697 }
1698
1699 void SystemDictionary::lazily_loaded_oops_do(OopClosure* f) {
1700 f->do_oop((oop*) &_abstract_ownable_synchronizer_klass);
1701 }
1702
1703 // Just the classes from defining class loaders
1704 // Don't iterate over placeholders
1705 void SystemDictionary::classes_do(void f(klassOop)) {
1706 dictionary()->classes_do(f);
1707 }
1708
1709 // Added for initialize_itable_for_klass
1710 // Just the classes from defining class loaders
1711 // Don't iterate over placeholders
1712 void SystemDictionary::classes_do(void f(klassOop, TRAPS), TRAPS) {
1713 dictionary()->classes_do(f, CHECK);
1714 }
1715
1716 // All classes, and their class loaders
1717 // Don't iterate over placeholders
1718 void SystemDictionary::classes_do(void f(klassOop, oop)) {
1719 dictionary()->classes_do(f);
1720 }
1721
1722 // All classes, and their class loaders
1723 // (added for helpers that use HandleMarks and ResourceMarks)
1724 // Don't iterate over placeholders
1725 void SystemDictionary::classes_do(void f(klassOop, oop, TRAPS), TRAPS) {
1726 dictionary()->classes_do(f, CHECK);
1727 }
1728
1729 void SystemDictionary::placeholders_do(void f(symbolOop, oop)) {
1730 placeholders()->entries_do(f);
1731 }
1732
1733 void SystemDictionary::methods_do(void f(methodOop)) {
1734 dictionary()->methods_do(f);
1735 }
1736
1737 // ----------------------------------------------------------------------------
1738 // Lazily load klasses
1739
1740 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
1741 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later");
1742
1743 // if multiple threads calling this function, only one thread will load
1744 // the class. The other threads will find the loaded version once the
1745 // class is loaded.
1746 klassOop aos = _abstract_ownable_synchronizer_klass;
1747 if (aos == NULL) {
1748 klassOop k = resolve_or_fail(vmSymbolHandles::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
1749 // Force a fence to prevent any read before the write completes
1750 OrderAccess::fence();
1751 _abstract_ownable_synchronizer_klass = k;
1752 }
1753 }
1754
1755 // ----------------------------------------------------------------------------
1756 // Initialization
1757
1758 void SystemDictionary::initialize(TRAPS) {
1759 // Allocate arrays
1760 assert(dictionary() == NULL,
1761 "SystemDictionary should only be initialized once");
1762 _dictionary = new Dictionary(_nof_buckets);
1763 _placeholders = new PlaceholderTable(_nof_buckets);
1764 _number_of_modifications = 0;
1765 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1766 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1767
1768 // Allocate private object used as system class loader lock
1769 _system_loader_lock_obj = oopFactory::new_system_objArray(0, CHECK);
1770 // Initialize basic classes
1771 initialize_preloaded_classes(CHECK);
1772 }
1773
1774 // Compact table of directions on the initialization of klasses:
1775 static const short wk_init_info[] = {
1776 #define WK_KLASS_INIT_INFO(name, symbol, option) \
1777 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
1778 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
1779 | (int)SystemDictionary::option ),
1780 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1781 #undef WK_KLASS_INIT_INFO
1782 0
1783 };
1784
1785 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
1786 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1787 int info = wk_init_info[id - FIRST_WKID];
1788 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1789 symbolHandle symbol = vmSymbolHandles::symbol_handle_at((vmSymbols::SID)sid);
1790 klassOop* klassp = &_well_known_klasses[id];
1791 bool must_load = (init_opt < SystemDictionary::Opt);
1792 bool try_load = true;
1793 if (init_opt == SystemDictionary::Opt_Kernel) {
1794 #ifndef KERNEL
1795 try_load = false;
1796 #endif //KERNEL
1797 }
1798 if ((*klassp) == NULL && try_load) {
1799 if (must_load) {
1800 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class
1801 } else {
1802 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass
1803 }
1804 }
1805 return ((*klassp) != NULL);
1806 }
1807
1808 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1809 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1810 for (int id = (int)start_id; id < (int)limit_id; id++) {
1811 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1812 int info = wk_init_info[id - FIRST_WKID];
1813 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1814 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
1815
1816 initialize_wk_klass((WKID)id, opt, CHECK);
1817
1818 // Update limits, so find_well_known_klass can be very fast:
1819 symbolOop s = vmSymbols::symbol_at((vmSymbols::SID)sid);
1820 if (wk_klass_name_limits[1] == NULL) {
1821 wk_klass_name_limits[0] = wk_klass_name_limits[1] = s;
1822 } else if (wk_klass_name_limits[1] < s) {
1823 wk_klass_name_limits[1] = s;
1824 } else if (wk_klass_name_limits[0] > s) {
1825 wk_klass_name_limits[0] = s;
1826 }
1827 }
1828 }
1829
1830
1831 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
1832 assert(WK_KLASS(object_klass) == NULL, "preloaded classes should only be initialized once");
1833 // Preload commonly used klasses
1834 WKID scan = FIRST_WKID;
1835 // first do Object, String, Class
1836 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(class_klass), scan, CHECK);
1837
1838 debug_only(instanceKlass::verify_class_klass_nonstatic_oop_maps(WK_KLASS(class_klass)));
1839
1840 // Fixup mirrors for classes loaded before java.lang.Class.
1841 // These calls iterate over the objects currently in the perm gen
1842 // so calling them at this point is matters (not before when there
1843 // are fewer objects and not later after there are more objects
1844 // in the perm gen.
1845 Universe::initialize_basic_type_mirrors(CHECK);
1846 Universe::fixup_mirrors(CHECK);
1847
1848 // do a bunch more:
1849 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(reference_klass), scan, CHECK);
1850
1851 // Preload ref klasses and set reference types
1852 instanceKlass::cast(WK_KLASS(reference_klass))->set_reference_type(REF_OTHER);
1853 instanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(reference_klass));
1854
1855 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(phantom_reference_klass), scan, CHECK);
1856 instanceKlass::cast(WK_KLASS(soft_reference_klass))->set_reference_type(REF_SOFT);
1857 instanceKlass::cast(WK_KLASS(weak_reference_klass))->set_reference_type(REF_WEAK);
1858 instanceKlass::cast(WK_KLASS(final_reference_klass))->set_reference_type(REF_FINAL);
1859 instanceKlass::cast(WK_KLASS(phantom_reference_klass))->set_reference_type(REF_PHANTOM);
1860
1861 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK);
1862
1863 _box_klasses[T_BOOLEAN] = WK_KLASS(boolean_klass);
1864 _box_klasses[T_CHAR] = WK_KLASS(char_klass);
1865 _box_klasses[T_FLOAT] = WK_KLASS(float_klass);
1866 _box_klasses[T_DOUBLE] = WK_KLASS(double_klass);
1867 _box_klasses[T_BYTE] = WK_KLASS(byte_klass);
1868 _box_klasses[T_SHORT] = WK_KLASS(short_klass);
1869 _box_klasses[T_INT] = WK_KLASS(int_klass);
1870 _box_klasses[T_LONG] = WK_KLASS(long_klass);
1871 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
1872 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
1873
1874 #ifdef KERNEL
1875 if (sun_jkernel_DownloadManager_klass() == NULL) {
1876 warning("Cannot find sun/jkernel/DownloadManager");
1877 }
1878 #endif // KERNEL
1879 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
1880 methodOop method = instanceKlass::cast(classloader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
1881 _has_loadClassInternal = (method != NULL);
1882 }
1883
1884 { // Compute whether we should use checkPackageAccess or NOT
1885 methodOop method = instanceKlass::cast(classloader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
1886 _has_checkPackageAccess = (method != NULL);
1887 }
1888 }
1889
1890 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
1891 // If so, returns the basic type it holds. If not, returns T_OBJECT.
1892 BasicType SystemDictionary::box_klass_type(klassOop k) {
1893 assert(k != NULL, "");
1894 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
1895 if (_box_klasses[i] == k)
1896 return (BasicType)i;
1897 }
1898 return T_OBJECT;
1899 }
1900
1901 // Constraints on class loaders. The details of the algorithm can be
1902 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
1903 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
1904 // that the system dictionary needs to maintain a set of contraints that
1905 // must be satisfied by all classes in the dictionary.
1906 // if defining is true, then LinkageError if already in systemDictionary
1907 // if initiating loader, then ok if instanceKlass matches existing entry
1908
1909 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
1910 instanceKlassHandle k,
1911 Handle class_loader, bool defining,
1912 TRAPS) {
1913 const char *linkage_error = NULL;
1914 {
1915 symbolHandle name (THREAD, k->name());
1916 MutexLocker mu(SystemDictionary_lock, THREAD);
1917
1918 klassOop check = find_class(d_index, d_hash, name, class_loader);
1919 if (check != (klassOop)NULL) {
1920 // if different instanceKlass - duplicate class definition,
1921 // else - ok, class loaded by a different thread in parallel,
1922 // we should only have found it if it was done loading and ok to use
1923 // system dictionary only holds instance classes, placeholders
1924 // also holds array classes
1925
1926 assert(check->klass_part()->oop_is_instance(), "noninstance in systemdictionary");
1927 if ((defining == true) || (k() != check)) {
1928 linkage_error = "loader (instance of %s): attempted duplicate class "
1929 "definition for name: \"%s\"";
1930 } else {
1931 return;
1932 }
1933 }
1934
1935 #ifdef ASSERT
1936 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
1937 int p_index = placeholders()->hash_to_index(p_hash);
1938 symbolOop ph_check = find_placeholder(p_index, p_hash, name, class_loader);
1939 assert(ph_check == NULL || ph_check == name(), "invalid symbol");
1940 #endif
1941
1942 if (linkage_error == NULL) {
1943 if (constraints()->check_or_update(k, class_loader, name) == false) {
1944 linkage_error = "loader constraint violation: loader (instance of %s)"
1945 " previously initiated loading for a different type with name \"%s\"";
1946 }
1947 }
1948 }
1949
1950 // Throw error now if needed (cannot throw while holding
1951 // SystemDictionary_lock because of rank ordering)
1952
1953 if (linkage_error) {
1954 ResourceMark rm(THREAD);
1955 const char* class_loader_name = loader_name(class_loader());
1956 char* type_name = k->name()->as_C_string();
1957 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) +
1958 strlen(type_name);
1959 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
1960 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name);
1961 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
1962 }
1963 }
1964
1965
1966 // Update system dictionary - done after check_constraint and add_to_hierachy
1967 // have been called.
1968 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
1969 int p_index, unsigned int p_hash,
1970 instanceKlassHandle k,
1971 Handle class_loader,
1972 TRAPS) {
1973 // Compile_lock prevents systemDictionary updates during compilations
1974 assert_locked_or_safepoint(Compile_lock);
1975 symbolHandle name (THREAD, k->name());
1976
1977 {
1978 MutexLocker mu1(SystemDictionary_lock, THREAD);
1979
1980 // See whether biased locking is enabled and if so set it for this
1981 // klass.
1982 // Note that this must be done past the last potential blocking
1983 // point / safepoint. We enable biased locking lazily using a
1984 // VM_Operation to iterate the SystemDictionary and installing the
1985 // biasable mark word into each instanceKlass's prototype header.
1986 // To avoid race conditions where we accidentally miss enabling the
1987 // optimization for one class in the process of being added to the
1988 // dictionary, we must not safepoint after the test of
1989 // BiasedLocking::enabled().
1990 if (UseBiasedLocking && BiasedLocking::enabled()) {
1991 // Set biased locking bit for all loaded classes; it will be
1992 // cleared if revocation occurs too often for this type
1993 // NOTE that we must only do this when the class is initally
1994 // defined, not each time it is referenced from a new class loader
1995 if (k->class_loader() == class_loader()) {
1996 k->set_prototype_header(markOopDesc::biased_locking_prototype());
1997 }
1998 }
1999
2000 // Check for a placeholder. If there, remove it and make a
2001 // new system dictionary entry.
2002 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
2003 klassOop sd_check = find_class(d_index, d_hash, name, class_loader);
2004 if (sd_check == NULL) {
2005 dictionary()->add_klass(name, class_loader, k);
2006 notice_modification();
2007 }
2008 #ifdef ASSERT
2009 sd_check = find_class(d_index, d_hash, name, class_loader);
2010 assert (sd_check != NULL, "should have entry in system dictionary");
2011 // Changed to allow PH to remain to complete class circularity checking
2012 // while only one thread can define a class at one time, multiple
2013 // classes can resolve the superclass for a class at one time,
2014 // and the placeholder is used to track that
2015 // symbolOop ph_check = find_placeholder(p_index, p_hash, name, class_loader);
2016 // assert (ph_check == NULL, "should not have a placeholder entry");
2017 #endif
2018 SystemDictionary_lock->notify_all();
2019 }
2020 }
2021
2022
2023 klassOop SystemDictionary::find_constrained_instance_or_array_klass(
2024 symbolHandle class_name, Handle class_loader, TRAPS) {
2025
2026 // First see if it has been loaded directly.
2027 // Force the protection domain to be null. (This removes protection checks.)
2028 Handle no_protection_domain;
2029 klassOop klass = find_instance_or_array_klass(class_name, class_loader,
2030 no_protection_domain, CHECK_NULL);
2031 if (klass != NULL)
2032 return klass;
2033
2034 // Now look to see if it has been loaded elsewhere, and is subject to
2035 // a loader constraint that would require this loader to return the
2036 // klass that is already loaded.
2037 if (FieldType::is_array(class_name())) {
2038 // Array classes are hard because their klassOops are not kept in the
2039 // constraint table. The array klass may be constrained, but the elem class
2040 // may not be.
2041 jint dimension;
2042 symbolOop object_key;
2043 BasicType t = FieldType::get_array_info(class_name(), &dimension,
2044 &object_key, CHECK_(NULL));
2045 if (t != T_OBJECT) {
2046 klass = Universe::typeArrayKlassObj(t);
2047 } else {
2048 symbolHandle elem_name(THREAD, object_key);
2049 MutexLocker mu(SystemDictionary_lock, THREAD);
2050 klass = constraints()->find_constrained_elem_klass(class_name, elem_name, class_loader, THREAD);
2051 }
2052 if (klass != NULL) {
2053 klass = Klass::cast(klass)->array_klass_or_null(dimension);
2054 }
2055 } else {
2056 MutexLocker mu(SystemDictionary_lock, THREAD);
2057 // Non-array classes are easy: simply check the constraint table.
2058 klass = constraints()->find_constrained_klass(class_name, class_loader);
2059 }
2060
2061 return klass;
2062 }
2063
2064
2065 bool SystemDictionary::add_loader_constraint(symbolHandle class_name,
2066 Handle class_loader1,
2067 Handle class_loader2,
2068 Thread* THREAD) {
2069 unsigned int d_hash1 = dictionary()->compute_hash(class_name, class_loader1);
2070 int d_index1 = dictionary()->hash_to_index(d_hash1);
2071
2072 unsigned int d_hash2 = dictionary()->compute_hash(class_name, class_loader2);
2073 int d_index2 = dictionary()->hash_to_index(d_hash2);
2074
2075 {
2076 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2077
2078 // Better never do a GC while we're holding these oops
2079 No_Safepoint_Verifier nosafepoint;
2080
2081 klassOop klass1 = find_class(d_index1, d_hash1, class_name, class_loader1);
2082 klassOop klass2 = find_class(d_index2, d_hash2, class_name, class_loader2);
2083 return constraints()->add_entry(class_name, klass1, class_loader1,
2084 klass2, class_loader2);
2085 }
2086 }
2087
2088 // Add entry to resolution error table to record the error when the first
2089 // attempt to resolve a reference to a class has failed.
2090 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, symbolHandle error) {
2091 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2092 int index = resolution_errors()->hash_to_index(hash);
2093 {
2094 MutexLocker ml(SystemDictionary_lock, Thread::current());
2095 resolution_errors()->add_entry(index, hash, pool, which, error);
2096 }
2097 }
2098
2099 // Lookup resolution error table. Returns error if found, otherwise NULL.
2100 symbolOop SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) {
2101 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2102 int index = resolution_errors()->hash_to_index(hash);
2103 {
2104 MutexLocker ml(SystemDictionary_lock, Thread::current());
2105 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2106 return (entry != NULL) ? entry->error() : (symbolOop)NULL;
2107 }
2108 }
2109
2110
2111 // Make sure all class components (including arrays) in the given
2112 // signature will be resolved to the same class in both loaders.
2113 // Returns the name of the type that failed a loader constraint check, or
2114 // NULL if no constraint failed. The returned C string needs cleaning up
2115 // with a ResourceMark in the caller
2116 char* SystemDictionary::check_signature_loaders(symbolHandle signature,
2117 Handle loader1, Handle loader2,
2118 bool is_method, TRAPS) {
2119 // Nothing to do if loaders are the same.
2120 if (loader1() == loader2()) {
2121 return NULL;
2122 }
2123
2124 SignatureStream sig_strm(signature, is_method);
2125 while (!sig_strm.is_done()) {
2126 if (sig_strm.is_object()) {
2127 symbolOop s = sig_strm.as_symbol(CHECK_NULL);
2128 symbolHandle sig (THREAD, s);
2129 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2130 return sig()->as_C_string();
2131 }
2132 }
2133 sig_strm.next();
2134 }
2135 return NULL;
2136 }
2137
2138
2139 // Since the identity hash code for symbols changes when the symbols are
2140 // moved from the regular perm gen (hash in the mark word) to the shared
2141 // spaces (hash is the address), the classes loaded into the dictionary
2142 // may be in the wrong buckets.
2143
2144 void SystemDictionary::reorder_dictionary() {
2145 dictionary()->reorder_dictionary();
2146 }
2147
2148
2149 void SystemDictionary::copy_buckets(char** top, char* end) {
2150 dictionary()->copy_buckets(top, end);
2151 }
2152
2153
2154 void SystemDictionary::copy_table(char** top, char* end) {
2155 dictionary()->copy_table(top, end);
2156 }
2157
2158
2159 void SystemDictionary::reverse() {
2160 dictionary()->reverse();
2161 }
2162
2163 int SystemDictionary::number_of_classes() {
2164 return dictionary()->number_of_entries();
2165 }
2166
2167
2168 // ----------------------------------------------------------------------------
2169 #ifndef PRODUCT
2170
2171 void SystemDictionary::print() {
2172 dictionary()->print();
2173
2174 // Placeholders
2175 GCMutexLocker mu(SystemDictionary_lock);
2176 placeholders()->print();
2177
2178 // loader constraints - print under SD_lock
2179 constraints()->print();
2180 }
2181
2182 #endif
2183
2184 void SystemDictionary::verify() {
2185 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2186 guarantee(constraints() != NULL,
2187 "Verify of loader constraints failed");
2188 guarantee(dictionary()->number_of_entries() >= 0 &&
2189 placeholders()->number_of_entries() >= 0,
2190 "Verify of system dictionary failed");
2191
2192 // Verify dictionary
2193 dictionary()->verify();
2194
2195 GCMutexLocker mu(SystemDictionary_lock);
2196 placeholders()->verify();
2197
2198 // Verify constraint table
2199 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2200 constraints()->verify(dictionary());
2201 }
2202
2203
2204 void SystemDictionary::verify_obj_klass_present(Handle obj,
2205 symbolHandle class_name,
2206 Handle class_loader) {
2207 GCMutexLocker mu(SystemDictionary_lock);
2208 oop probe = find_class_or_placeholder(class_name, class_loader);
2209 if (probe == NULL) {
2210 probe = SystemDictionary::find_shared_class(class_name);
2211 }
2212 guarantee(probe != NULL &&
2213 (!probe->is_klass() || probe == obj()),
2214 "Loaded klasses should be in SystemDictionary");
2215 }
2216
2217 #ifndef PRODUCT
2218
2219 // statistics code
2220 class ClassStatistics: AllStatic {
2221 private:
2222 static int nclasses; // number of classes
2223 static int nmethods; // number of methods
2224 static int nmethoddata; // number of methodData
2225 static int class_size; // size of class objects in words
2226 static int method_size; // size of method objects in words
2227 static int debug_size; // size of debug info in methods
2228 static int methoddata_size; // size of methodData objects in words
2229
2230 static void do_class(klassOop k) {
2231 nclasses++;
2232 class_size += k->size();
2233 if (k->klass_part()->oop_is_instance()) {
2234 instanceKlass* ik = (instanceKlass*)k->klass_part();
2235 class_size += ik->methods()->size();
2236 class_size += ik->constants()->size();
2237 class_size += ik->local_interfaces()->size();
2238 class_size += ik->transitive_interfaces()->size();
2239 // We do not have to count implementors, since we only store one!
2240 class_size += ik->fields()->size();
2241 }
2242 }
2243
2244 static void do_method(methodOop m) {
2245 nmethods++;
2246 method_size += m->size();
2247 // class loader uses same objArray for empty vectors, so don't count these
2248 if (m->exception_table()->length() != 0) method_size += m->exception_table()->size();
2249 if (m->has_stackmap_table()) {
2250 method_size += m->stackmap_data()->size();
2251 }
2252
2253 methodDataOop mdo = m->method_data();
2254 if (mdo != NULL) {
2255 nmethoddata++;
2256 methoddata_size += mdo->size();
2257 }
2258 }
2259
2260 public:
2261 static void print() {
2262 SystemDictionary::classes_do(do_class);
2263 SystemDictionary::methods_do(do_method);
2264 tty->print_cr("Class statistics:");
2265 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize);
2266 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods,
2267 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize);
2268 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize);
2269 }
2270 };
2271
2272
2273 int ClassStatistics::nclasses = 0;
2274 int ClassStatistics::nmethods = 0;
2275 int ClassStatistics::nmethoddata = 0;
2276 int ClassStatistics::class_size = 0;
2277 int ClassStatistics::method_size = 0;
2278 int ClassStatistics::debug_size = 0;
2279 int ClassStatistics::methoddata_size = 0;
2280
2281 void SystemDictionary::print_class_statistics() {
2282 ResourceMark rm;
2283 ClassStatistics::print();
2284 }
2285
2286
2287 class MethodStatistics: AllStatic {
2288 public:
2289 enum {
2290 max_parameter_size = 10
2291 };
2292 private:
2293
2294 static int _number_of_methods;
2295 static int _number_of_final_methods;
2296 static int _number_of_static_methods;
2297 static int _number_of_native_methods;
2298 static int _number_of_synchronized_methods;
2299 static int _number_of_profiled_methods;
2300 static int _number_of_bytecodes;
2301 static int _parameter_size_profile[max_parameter_size];
2302 static int _bytecodes_profile[Bytecodes::number_of_java_codes];
2303
2304 static void initialize() {
2305 _number_of_methods = 0;
2306 _number_of_final_methods = 0;
2307 _number_of_static_methods = 0;
2308 _number_of_native_methods = 0;
2309 _number_of_synchronized_methods = 0;
2310 _number_of_profiled_methods = 0;
2311 _number_of_bytecodes = 0;
2312 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0;
2313 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0;
2314 };
2315
2316 static void do_method(methodOop m) {
2317 _number_of_methods++;
2318 // collect flag info
2319 if (m->is_final() ) _number_of_final_methods++;
2320 if (m->is_static() ) _number_of_static_methods++;
2321 if (m->is_native() ) _number_of_native_methods++;
2322 if (m->is_synchronized()) _number_of_synchronized_methods++;
2323 if (m->method_data() != NULL) _number_of_profiled_methods++;
2324 // collect parameter size info (add one for receiver, if any)
2325 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++;
2326 // collect bytecodes info
2327 {
2328 Thread *thread = Thread::current();
2329 HandleMark hm(thread);
2330 BytecodeStream s(methodHandle(thread, m));
2331 Bytecodes::Code c;
2332 while ((c = s.next()) >= 0) {
2333 _number_of_bytecodes++;
2334 _bytecodes_profile[c]++;
2335 }
2336 }
2337 }
2338
2339 public:
2340 static void print() {
2341 initialize();
2342 SystemDictionary::methods_do(do_method);
2343 // generate output
2344 tty->cr();
2345 tty->print_cr("Method statistics (static):");
2346 // flag distribution
2347 tty->cr();
2348 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods);
2349 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods);
2350 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods);
2351 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods);
2352 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods);
2353 // parameter size profile
2354 tty->cr();
2355 { int tot = 0;
2356 int avg = 0;
2357 for (int i = 0; i < max_parameter_size; i++) {
2358 int n = _parameter_size_profile[i];
2359 tot += n;
2360 avg += n*i;
2361 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods);
2362 }
2363 assert(tot == _number_of_methods, "should be the same");
2364 tty->print_cr(" %6d methods 100.0%%", _number_of_methods);
2365 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods);
2366 }
2367 // bytecodes profile
2368 tty->cr();
2369 { int tot = 0;
2370 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) {
2371 if (Bytecodes::is_defined(i)) {
2372 Bytecodes::Code c = Bytecodes::cast(i);
2373 int n = _bytecodes_profile[c];
2374 tot += n;
2375 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c));
2376 }
2377 }
2378 assert(tot == _number_of_bytecodes, "should be the same");
2379 tty->print_cr("%9d 100.000%%", _number_of_bytecodes);
2380 }
2381 tty->cr();
2382 }
2383 };
2384
2385 int MethodStatistics::_number_of_methods;
2386 int MethodStatistics::_number_of_final_methods;
2387 int MethodStatistics::_number_of_static_methods;
2388 int MethodStatistics::_number_of_native_methods;
2389 int MethodStatistics::_number_of_synchronized_methods;
2390 int MethodStatistics::_number_of_profiled_methods;
2391 int MethodStatistics::_number_of_bytecodes;
2392 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size];
2393 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes];
2394
2395
2396 void SystemDictionary::print_method_statistics() {
2397 MethodStatistics::print();
2398 }
2399
2400 #endif // PRODUCT