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rev 6909 : 8065361: Fixup headers and definitions for INCLUDE_TRACE
Reviewed-by: sla, stefank
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--- old/hotspot/src/share/vm/classfile/systemDictionary.cpp
+++ new/hotspot/src/share/vm/classfile/systemDictionary.cpp
1 1 /*
2 2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 20 * or visit www.oracle.com if you need additional information or have any
21 21 * questions.
22 22 *
23 23 */
24 24
25 25 #include "precompiled.hpp"
26 26 #include "classfile/classLoaderData.inline.hpp"
27 27 #include "classfile/dictionary.hpp"
28 28 #include "classfile/javaClasses.hpp"
29 29 #include "classfile/loaderConstraints.hpp"
30 30 #include "classfile/placeholders.hpp"
31 31 #include "classfile/resolutionErrors.hpp"
32 32 #include "classfile/systemDictionary.hpp"
33 33 #if INCLUDE_CDS
34 34 #include "classfile/sharedClassUtil.hpp"
35 35 #include "classfile/systemDictionaryShared.hpp"
36 36 #endif
37 37 #include "classfile/vmSymbols.hpp"
38 38 #include "compiler/compileBroker.hpp"
39 39 #include "interpreter/bytecodeStream.hpp"
40 40 #include "interpreter/interpreter.hpp"
41 41 #include "memory/filemap.hpp"
42 42 #include "memory/gcLocker.hpp"
43 43 #include "memory/oopFactory.hpp"
44 44 #include "oops/instanceKlass.hpp"
45 45 #include "oops/instanceRefKlass.hpp"
46 46 #include "oops/klass.inline.hpp"
47 47 #include "oops/methodData.hpp"
48 48 #include "oops/objArrayKlass.hpp"
49 49 #include "oops/oop.inline.hpp"
50 50 #include "oops/oop.inline2.hpp"
51 51 #include "oops/typeArrayKlass.hpp"
52 52 #include "prims/jvmtiEnvBase.hpp"
53 53 #include "prims/methodHandles.hpp"
54 54 #include "runtime/arguments.hpp"
55 55 #include "runtime/biasedLocking.hpp"
56 56 #include "runtime/fieldType.hpp"
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57 57 #include "runtime/handles.inline.hpp"
58 58 #include "runtime/java.hpp"
59 59 #include "runtime/javaCalls.hpp"
60 60 #include "runtime/mutexLocker.hpp"
61 61 #include "runtime/orderAccess.inline.hpp"
62 62 #include "runtime/signature.hpp"
63 63 #include "services/classLoadingService.hpp"
64 64 #include "services/threadService.hpp"
65 65 #include "utilities/macros.hpp"
66 66 #include "utilities/ticks.hpp"
67 -
68 67 #if INCLUDE_TRACE
69 - #include "trace/tracing.hpp"
68 +#include "trace/tracing.hpp"
70 69 #endif
71 70
72 71 Dictionary* SystemDictionary::_dictionary = NULL;
73 72 PlaceholderTable* SystemDictionary::_placeholders = NULL;
74 73 Dictionary* SystemDictionary::_shared_dictionary = NULL;
75 74 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
76 75 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
77 76 SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
78 77
79 78
80 79 int SystemDictionary::_number_of_modifications = 0;
81 80 int SystemDictionary::_sdgeneration = 0;
82 81 const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
83 82 20201,40423,99991};
84 83
85 84 oop SystemDictionary::_system_loader_lock_obj = NULL;
86 85
87 86 Klass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
88 87 = { NULL /*, NULL...*/ };
89 88
90 89 Klass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
91 90
92 91 oop SystemDictionary::_java_system_loader = NULL;
93 92
94 93 bool SystemDictionary::_has_loadClassInternal = false;
95 94 bool SystemDictionary::_has_checkPackageAccess = false;
96 95
97 96 // lazily initialized klass variables
98 97 Klass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
99 98
100 99
101 100 // ----------------------------------------------------------------------------
102 101 // Java-level SystemLoader
103 102
104 103 oop SystemDictionary::java_system_loader() {
105 104 return _java_system_loader;
106 105 }
107 106
108 107 void SystemDictionary::compute_java_system_loader(TRAPS) {
109 108 KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass));
110 109 JavaValue result(T_OBJECT);
111 110 JavaCalls::call_static(&result,
112 111 KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)),
113 112 vmSymbols::getSystemClassLoader_name(),
114 113 vmSymbols::void_classloader_signature(),
115 114 CHECK);
116 115
117 116 _java_system_loader = (oop)result.get_jobject();
118 117
119 118 CDS_ONLY(SystemDictionaryShared::initialize(CHECK);)
120 119 }
121 120
122 121
123 122 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
124 123 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
125 124 return ClassLoaderDataGraph::find_or_create(class_loader, CHECK_NULL);
126 125 }
127 126
128 127 // ----------------------------------------------------------------------------
129 128 // debugging
130 129
131 130 #ifdef ASSERT
132 131
133 132 // return true if class_name contains no '.' (internal format is '/')
134 133 bool SystemDictionary::is_internal_format(Symbol* class_name) {
135 134 if (class_name != NULL) {
136 135 ResourceMark rm;
137 136 char* name = class_name->as_C_string();
138 137 return strchr(name, '.') == NULL;
139 138 } else {
140 139 return true;
141 140 }
142 141 }
143 142
144 143 #endif
145 144
146 145 // ----------------------------------------------------------------------------
147 146 // Parallel class loading check
148 147
149 148 bool SystemDictionary::is_parallelCapable(Handle class_loader) {
150 149 if (UnsyncloadClass || class_loader.is_null()) return true;
151 150 if (AlwaysLockClassLoader) return false;
152 151 return java_lang_ClassLoader::parallelCapable(class_loader());
153 152 }
154 153 // ----------------------------------------------------------------------------
155 154 // ParallelDefineClass flag does not apply to bootclass loader
156 155 bool SystemDictionary::is_parallelDefine(Handle class_loader) {
157 156 if (class_loader.is_null()) return false;
158 157 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
159 158 return true;
160 159 }
161 160 return false;
162 161 }
163 162
164 163 /**
165 164 * Returns true if the passed class loader is the extension class loader.
166 165 */
167 166 bool SystemDictionary::is_ext_class_loader(Handle class_loader) {
168 167 if (class_loader.is_null()) {
169 168 return false;
170 169 }
171 170 return (class_loader->klass()->name() == vmSymbols::sun_misc_Launcher_ExtClassLoader());
172 171 }
173 172
174 173 // ----------------------------------------------------------------------------
175 174 // Resolving of classes
176 175
177 176 // Forwards to resolve_or_null
178 177
179 178 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
180 179 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
181 180 if (HAS_PENDING_EXCEPTION || klass == NULL) {
182 181 KlassHandle k_h(THREAD, klass);
183 182 // can return a null klass
184 183 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
185 184 }
186 185 return klass;
187 186 }
188 187
189 188 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) {
190 189 if (HAS_PENDING_EXCEPTION) {
191 190 // If we have a pending exception we forward it to the caller, unless throw_error is true,
192 191 // in which case we have to check whether the pending exception is a ClassNotFoundException,
193 192 // and if so convert it to a NoClassDefFoundError
194 193 // And chain the original ClassNotFoundException
195 194 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
196 195 ResourceMark rm(THREAD);
197 196 assert(klass_h() == NULL, "Should not have result with exception pending");
198 197 Handle e(THREAD, PENDING_EXCEPTION);
199 198 CLEAR_PENDING_EXCEPTION;
200 199 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
201 200 } else {
202 201 return NULL;
203 202 }
204 203 }
205 204 // Class not found, throw appropriate error or exception depending on value of throw_error
206 205 if (klass_h() == NULL) {
207 206 ResourceMark rm(THREAD);
208 207 if (throw_error) {
209 208 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
210 209 } else {
211 210 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
212 211 }
213 212 }
214 213 return (Klass*)klass_h();
215 214 }
216 215
217 216
218 217 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
219 218 bool throw_error, TRAPS)
220 219 {
221 220 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
222 221 }
223 222
224 223
225 224 // Forwards to resolve_instance_class_or_null
226 225
227 226 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
228 227 assert(!THREAD->is_Compiler_thread(),
229 228 err_msg("can not load classes with compiler thread: class=%s, classloader=%s",
230 229 class_name->as_C_string(),
231 230 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string()));
232 231 if (FieldType::is_array(class_name)) {
233 232 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
234 233 } else if (FieldType::is_obj(class_name)) {
235 234 ResourceMark rm(THREAD);
236 235 // Ignore wrapping L and ;.
237 236 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
238 237 class_name->utf8_length() - 2, CHECK_NULL);
239 238 return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL);
240 239 } else {
241 240 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
242 241 }
243 242 }
244 243
245 244 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
246 245 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
247 246 }
248 247
249 248 // Forwards to resolve_instance_class_or_null
250 249
251 250 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
252 251 Handle class_loader,
253 252 Handle protection_domain,
254 253 TRAPS) {
255 254 assert(FieldType::is_array(class_name), "must be array");
256 255 Klass* k = NULL;
257 256 FieldArrayInfo fd;
258 257 // dimension and object_key in FieldArrayInfo are assigned as a side-effect
259 258 // of this call
260 259 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
261 260 if (t == T_OBJECT) {
262 261 // naked oop "k" is OK here -- we assign back into it
263 262 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
264 263 class_loader,
265 264 protection_domain,
266 265 CHECK_NULL);
267 266 if (k != NULL) {
268 267 k = k->array_klass(fd.dimension(), CHECK_NULL);
269 268 }
270 269 } else {
271 270 k = Universe::typeArrayKlassObj(t);
272 271 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
273 272 }
274 273 return k;
275 274 }
276 275
277 276
278 277 // Must be called for any super-class or super-interface resolution
279 278 // during class definition to allow class circularity checking
280 279 // super-interface callers:
281 280 // parse_interfaces - for defineClass & jvmtiRedefineClasses
282 281 // super-class callers:
283 282 // ClassFileParser - for defineClass & jvmtiRedefineClasses
284 283 // load_shared_class - while loading a class from shared archive
285 284 // resolve_instance_class_or_null:
286 285 // via: handle_parallel_super_load
287 286 // when resolving a class that has an existing placeholder with
288 287 // a saved superclass [i.e. a defineClass is currently in progress]
289 288 // if another thread is trying to resolve the class, it must do
290 289 // super-class checks on its own thread to catch class circularity
291 290 // This last call is critical in class circularity checking for cases
292 291 // where classloading is delegated to different threads and the
293 292 // classloader lock is released.
294 293 // Take the case: Base->Super->Base
295 294 // 1. If thread T1 tries to do a defineClass of class Base
296 295 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
297 296 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
298 297 // so it tries to load Super
299 298 // 3. If we load the class internally, or user classloader uses same thread
300 299 // loadClassFromxxx or defineClass via parseClassFile Super ...
301 300 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
302 301 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
303 302 // 3.4 calls resolve_super_or_fail Base
304 303 // 3.5 finds T1,Base -> throws class circularity
305 304 //OR 4. If T2 tries to resolve Super via defineClass Super ...
306 305 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
307 306 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
308 307 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
309 308 // 4.4 finds T2, Super -> throws class circularity
310 309 // Must be called, even if superclass is null, since this is
311 310 // where the placeholder entry is created which claims this
312 311 // thread is loading this class/classloader.
313 312 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
314 313 Symbol* class_name,
315 314 Handle class_loader,
316 315 Handle protection_domain,
317 316 bool is_superclass,
318 317 TRAPS) {
319 318 // Double-check, if child class is already loaded, just return super-class,interface
320 319 // Don't add a placedholder if already loaded, i.e. already in system dictionary
321 320 // Make sure there's a placeholder for the *child* before resolving.
322 321 // Used as a claim that this thread is currently loading superclass/classloader
323 322 // Used here for ClassCircularity checks and also for heap verification
324 323 // (every InstanceKlass in the heap needs to be in the system dictionary
325 324 // or have a placeholder).
326 325 // Must check ClassCircularity before checking if super class is already loaded
327 326 //
328 327 // We might not already have a placeholder if this child_name was
329 328 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
330 329 // the name of the class might not be known until the stream is actually
331 330 // parsed.
332 331 // Bugs 4643874, 4715493
333 332 // compute_hash can have a safepoint
334 333
335 334 ClassLoaderData* loader_data = class_loader_data(class_loader);
336 335 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
337 336 int d_index = dictionary()->hash_to_index(d_hash);
338 337 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
339 338 int p_index = placeholders()->hash_to_index(p_hash);
340 339 // can't throw error holding a lock
341 340 bool child_already_loaded = false;
342 341 bool throw_circularity_error = false;
343 342 {
344 343 MutexLocker mu(SystemDictionary_lock, THREAD);
345 344 Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
346 345 Klass* quicksuperk;
347 346 // to support // loading: if child done loading, just return superclass
348 347 // if class_name, & class_loader don't match:
349 348 // if initial define, SD update will give LinkageError
350 349 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
351 350 // so we don't throw an exception here.
352 351 // see: nsk redefclass014 & java.lang.instrument Instrument032
353 352 if ((childk != NULL ) && (is_superclass) &&
354 353 ((quicksuperk = InstanceKlass::cast(childk)->super()) != NULL) &&
355 354
356 355 ((quicksuperk->name() == class_name) &&
357 356 (quicksuperk->class_loader() == class_loader()))) {
358 357 return quicksuperk;
359 358 } else {
360 359 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
361 360 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
362 361 throw_circularity_error = true;
363 362 }
364 363 }
365 364 if (!throw_circularity_error) {
366 365 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
367 366 }
368 367 }
369 368 if (throw_circularity_error) {
370 369 ResourceMark rm(THREAD);
371 370 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
372 371 }
373 372
374 373 // java.lang.Object should have been found above
375 374 assert(class_name != NULL, "null super class for resolving");
376 375 // Resolve the super class or interface, check results on return
377 376 Klass* superk = SystemDictionary::resolve_or_null(class_name,
378 377 class_loader,
379 378 protection_domain,
380 379 THREAD);
381 380
382 381 KlassHandle superk_h(THREAD, superk);
383 382
384 383 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up
385 384 // It is no longer necessary to keep the placeholder table alive until update_dictionary
386 385 // or error. GC used to walk the placeholder table as strong roots.
387 386 // The instanceKlass is kept alive because the class loader is on the stack,
388 387 // which keeps the loader_data alive, as well as all instanceKlasses in
389 388 // the loader_data. parseClassFile adds the instanceKlass to loader_data.
390 389 {
391 390 MutexLocker mu(SystemDictionary_lock, THREAD);
392 391 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
393 392 SystemDictionary_lock->notify_all();
394 393 }
395 394 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
396 395 // can null superk
397 396 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD));
398 397 }
399 398
400 399 return superk_h();
401 400 }
402 401
403 402 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
404 403 Handle class_loader,
405 404 Handle protection_domain,
406 405 TRAPS) {
407 406 if(!has_checkPackageAccess()) return;
408 407
409 408 // Now we have to call back to java to check if the initating class has access
410 409 JavaValue result(T_VOID);
411 410 if (TraceProtectionDomainVerification) {
412 411 // Print out trace information
413 412 tty->print_cr("Checking package access");
414 413 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr();
415 414 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr();
416 415 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr();
417 416 }
418 417
419 418 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass());
420 419 JavaCalls::call_special(&result,
421 420 class_loader,
422 421 system_loader,
423 422 vmSymbols::checkPackageAccess_name(),
424 423 vmSymbols::class_protectiondomain_signature(),
425 424 Handle(THREAD, klass->java_mirror()),
426 425 protection_domain,
427 426 THREAD);
428 427
429 428 if (TraceProtectionDomainVerification) {
430 429 if (HAS_PENDING_EXCEPTION) {
431 430 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!");
432 431 } else {
433 432 tty->print_cr(" -> granted");
434 433 }
435 434 tty->cr();
436 435 }
437 436
438 437 if (HAS_PENDING_EXCEPTION) return;
439 438
440 439 // If no exception has been thrown, we have validated the protection domain
441 440 // Insert the protection domain of the initiating class into the set.
442 441 {
443 442 // We recalculate the entry here -- we've called out to java since
444 443 // the last time it was calculated.
445 444 ClassLoaderData* loader_data = class_loader_data(class_loader);
446 445
447 446 Symbol* kn = klass->name();
448 447 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
449 448 int d_index = dictionary()->hash_to_index(d_hash);
450 449
451 450 MutexLocker mu(SystemDictionary_lock, THREAD);
452 451 {
453 452 // Note that we have an entry, and entries can be deleted only during GC,
454 453 // so we cannot allow GC to occur while we're holding this entry.
455 454
456 455 // We're using a No_Safepoint_Verifier to catch any place where we
457 456 // might potentially do a GC at all.
458 457 // Dictionary::do_unloading() asserts that classes in SD are only
459 458 // unloaded at a safepoint. Anonymous classes are not in SD.
460 459 No_Safepoint_Verifier nosafepoint;
461 460 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
462 461 protection_domain, THREAD);
463 462 }
464 463 }
465 464 }
466 465
467 466 // We only get here if this thread finds that another thread
468 467 // has already claimed the placeholder token for the current operation,
469 468 // but that other thread either never owned or gave up the
470 469 // object lock
471 470 // Waits on SystemDictionary_lock to indicate placeholder table updated
472 471 // On return, caller must recheck placeholder table state
473 472 //
474 473 // We only get here if
475 474 // 1) custom classLoader, i.e. not bootstrap classloader
476 475 // 2) UnsyncloadClass not set
477 476 // 3) custom classLoader has broken the class loader objectLock
478 477 // so another thread got here in parallel
479 478 //
480 479 // lockObject must be held.
481 480 // Complicated dance due to lock ordering:
482 481 // Must first release the classloader object lock to
483 482 // allow initial definer to complete the class definition
484 483 // and to avoid deadlock
485 484 // Reclaim classloader lock object with same original recursion count
486 485 // Must release SystemDictionary_lock after notify, since
487 486 // class loader lock must be claimed before SystemDictionary_lock
488 487 // to prevent deadlocks
489 488 //
490 489 // The notify allows applications that did an untimed wait() on
491 490 // the classloader object lock to not hang.
492 491 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
493 492 assert_lock_strong(SystemDictionary_lock);
494 493
495 494 bool calledholdinglock
496 495 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
497 496 assert(calledholdinglock,"must hold lock for notify");
498 497 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
499 498 ObjectSynchronizer::notifyall(lockObject, THREAD);
500 499 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
501 500 SystemDictionary_lock->wait();
502 501 SystemDictionary_lock->unlock();
503 502 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
504 503 SystemDictionary_lock->lock();
505 504 }
506 505
507 506 // If the class in is in the placeholder table, class loading is in progress
508 507 // For cases where the application changes threads to load classes, it
509 508 // is critical to ClassCircularity detection that we try loading
510 509 // the superclass on the same thread internally, so we do parallel
511 510 // super class loading here.
512 511 // This also is critical in cases where the original thread gets stalled
513 512 // even in non-circularity situations.
514 513 // Note: must call resolve_super_or_fail even if null super -
515 514 // to force placeholder entry creation for this class for circularity detection
516 515 // Caller must check for pending exception
517 516 // Returns non-null Klass* if other thread has completed load
518 517 // and we are done,
519 518 // If return null Klass* and no pending exception, the caller must load the class
520 519 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
521 520 Symbol* name, Symbol* superclassname, Handle class_loader,
522 521 Handle protection_domain, Handle lockObject, TRAPS) {
523 522
524 523 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
525 524 ClassLoaderData* loader_data = class_loader_data(class_loader);
526 525 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
527 526 int d_index = dictionary()->hash_to_index(d_hash);
528 527 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
529 528 int p_index = placeholders()->hash_to_index(p_hash);
530 529
531 530 // superk is not used, resolve_super called for circularity check only
532 531 // This code is reached in two situations. One if this thread
533 532 // is loading the same class twice (e.g. ClassCircularity, or
534 533 // java.lang.instrument).
535 534 // The second is if another thread started the resolve_super first
536 535 // and has not yet finished.
537 536 // In both cases the original caller will clean up the placeholder
538 537 // entry on error.
539 538 Klass* superk = SystemDictionary::resolve_super_or_fail(name,
540 539 superclassname,
541 540 class_loader,
542 541 protection_domain,
543 542 true,
544 543 CHECK_(nh));
545 544
546 545 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete
547 546 // Serial class loaders and bootstrap classloader do wait for superclass loads
548 547 if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
549 548 MutexLocker mu(SystemDictionary_lock, THREAD);
550 549 // Check if classloading completed while we were loading superclass or waiting
551 550 Klass* check = find_class(d_index, d_hash, name, loader_data);
552 551 if (check != NULL) {
553 552 // Klass is already loaded, so just return it
554 553 return(instanceKlassHandle(THREAD, check));
555 554 } else {
556 555 return nh;
557 556 }
558 557 }
559 558
560 559 // must loop to both handle other placeholder updates
561 560 // and spurious notifications
562 561 bool super_load_in_progress = true;
563 562 PlaceholderEntry* placeholder;
564 563 while (super_load_in_progress) {
565 564 MutexLocker mu(SystemDictionary_lock, THREAD);
566 565 // Check if classloading completed while we were loading superclass or waiting
567 566 Klass* check = find_class(d_index, d_hash, name, loader_data);
568 567 if (check != NULL) {
569 568 // Klass is already loaded, so just return it
570 569 return(instanceKlassHandle(THREAD, check));
571 570 } else {
572 571 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
573 572 if (placeholder && placeholder->super_load_in_progress() ){
574 573 // Before UnsyncloadClass:
575 574 // We only get here if the application has released the
576 575 // classloader lock when another thread was in the middle of loading a
577 576 // superclass/superinterface for this class, and now
578 577 // this thread is also trying to load this class.
579 578 // To minimize surprises, the first thread that started to
580 579 // load a class should be the one to complete the loading
581 580 // with the classfile it initially expected.
582 581 // This logic has the current thread wait once it has done
583 582 // all the superclass/superinterface loading it can, until
584 583 // the original thread completes the class loading or fails
585 584 // If it completes we will use the resulting InstanceKlass
586 585 // which we will find below in the systemDictionary.
587 586 // We also get here for parallel bootstrap classloader
588 587 if (class_loader.is_null()) {
589 588 SystemDictionary_lock->wait();
590 589 } else {
591 590 double_lock_wait(lockObject, THREAD);
592 591 }
593 592 } else {
594 593 // If not in SD and not in PH, other thread's load must have failed
595 594 super_load_in_progress = false;
596 595 }
597 596 }
598 597 }
599 598 return (nh);
600 599 }
601 600
602 601
603 602 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
604 603 Handle class_loader,
605 604 Handle protection_domain,
606 605 TRAPS) {
607 606 assert(name != NULL && !FieldType::is_array(name) &&
608 607 !FieldType::is_obj(name), "invalid class name");
609 608
610 609 Ticks class_load_start_time = Ticks::now();
611 610
612 611 // UseNewReflection
613 612 // Fix for 4474172; see evaluation for more details
614 613 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
615 614 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
616 615
617 616 // Do lookup to see if class already exist and the protection domain
618 617 // has the right access
619 618 // This call uses find which checks protection domain already matches
620 619 // All subsequent calls use find_class, and set has_loaded_class so that
621 620 // before we return a result we call out to java to check for valid protection domain
622 621 // to allow returning the Klass* and add it to the pd_set if it is valid
623 622 unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
624 623 int d_index = dictionary()->hash_to_index(d_hash);
625 624 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
626 625 protection_domain, THREAD);
627 626 if (probe != NULL) return probe;
628 627
629 628
630 629 // Non-bootstrap class loaders will call out to class loader and
631 630 // define via jvm/jni_DefineClass which will acquire the
632 631 // class loader object lock to protect against multiple threads
633 632 // defining the class in parallel by accident.
634 633 // This lock must be acquired here so the waiter will find
635 634 // any successful result in the SystemDictionary and not attempt
636 635 // the define
637 636 // ParallelCapable Classloaders and the bootstrap classloader,
638 637 // or all classloaders with UnsyncloadClass do not acquire lock here
639 638 bool DoObjectLock = true;
640 639 if (is_parallelCapable(class_loader)) {
641 640 DoObjectLock = false;
642 641 }
643 642
644 643 unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
645 644 int p_index = placeholders()->hash_to_index(p_hash);
646 645
647 646 // Class is not in SystemDictionary so we have to do loading.
648 647 // Make sure we are synchronized on the class loader before we proceed
649 648 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
650 649 check_loader_lock_contention(lockObject, THREAD);
651 650 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
652 651
653 652 // Check again (after locking) if class already exist in SystemDictionary
654 653 bool class_has_been_loaded = false;
655 654 bool super_load_in_progress = false;
656 655 bool havesupername = false;
657 656 instanceKlassHandle k;
658 657 PlaceholderEntry* placeholder;
659 658 Symbol* superclassname = NULL;
660 659
661 660 {
662 661 MutexLocker mu(SystemDictionary_lock, THREAD);
663 662 Klass* check = find_class(d_index, d_hash, name, loader_data);
664 663 if (check != NULL) {
665 664 // Klass is already loaded, so just return it
666 665 class_has_been_loaded = true;
667 666 k = instanceKlassHandle(THREAD, check);
668 667 } else {
669 668 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
670 669 if (placeholder && placeholder->super_load_in_progress()) {
671 670 super_load_in_progress = true;
672 671 if (placeholder->havesupername() == true) {
673 672 superclassname = placeholder->supername();
674 673 havesupername = true;
675 674 }
676 675 }
677 676 }
678 677 }
679 678
680 679 // If the class is in the placeholder table, class loading is in progress
681 680 if (super_load_in_progress && havesupername==true) {
682 681 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
683 682 class_loader, protection_domain, lockObject, THREAD);
684 683 if (HAS_PENDING_EXCEPTION) {
685 684 return NULL;
686 685 }
687 686 if (!k.is_null()) {
688 687 class_has_been_loaded = true;
689 688 }
690 689 }
691 690
692 691 bool throw_circularity_error = false;
693 692 if (!class_has_been_loaded) {
694 693 bool load_instance_added = false;
695 694
696 695 // add placeholder entry to record loading instance class
697 696 // Five cases:
698 697 // All cases need to prevent modifying bootclasssearchpath
699 698 // in parallel with a classload of same classname
700 699 // Redefineclasses uses existence of the placeholder for the duration
701 700 // of the class load to prevent concurrent redefinition of not completely
702 701 // defined classes.
703 702 // case 1. traditional classloaders that rely on the classloader object lock
704 703 // - no other need for LOAD_INSTANCE
705 704 // case 2. traditional classloaders that break the classloader object lock
706 705 // as a deadlock workaround. Detection of this case requires that
707 706 // this check is done while holding the classloader object lock,
708 707 // and that lock is still held when calling classloader's loadClass.
709 708 // For these classloaders, we ensure that the first requestor
710 709 // completes the load and other requestors wait for completion.
711 710 // case 3. UnsyncloadClass - don't use objectLocker
712 711 // With this flag, we allow parallel classloading of a
713 712 // class/classloader pair
714 713 // case4. Bootstrap classloader - don't own objectLocker
715 714 // This classloader supports parallelism at the classloader level,
716 715 // but only allows a single load of a class/classloader pair.
717 716 // No performance benefit and no deadlock issues.
718 717 // case 5. parallelCapable user level classloaders - without objectLocker
719 718 // Allow parallel classloading of a class/classloader pair
720 719
721 720 {
722 721 MutexLocker mu(SystemDictionary_lock, THREAD);
723 722 if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
724 723 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
725 724 if (oldprobe) {
726 725 // only need check_seen_thread once, not on each loop
727 726 // 6341374 java/lang/Instrument with -Xcomp
728 727 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
729 728 throw_circularity_error = true;
730 729 } else {
731 730 // case 1: traditional: should never see load_in_progress.
732 731 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
733 732
734 733 // case 4: bootstrap classloader: prevent futile classloading,
735 734 // wait on first requestor
736 735 if (class_loader.is_null()) {
737 736 SystemDictionary_lock->wait();
738 737 } else {
739 738 // case 2: traditional with broken classloader lock. wait on first
740 739 // requestor.
741 740 double_lock_wait(lockObject, THREAD);
742 741 }
743 742 // Check if classloading completed while we were waiting
744 743 Klass* check = find_class(d_index, d_hash, name, loader_data);
745 744 if (check != NULL) {
746 745 // Klass is already loaded, so just return it
747 746 k = instanceKlassHandle(THREAD, check);
748 747 class_has_been_loaded = true;
749 748 }
750 749 // check if other thread failed to load and cleaned up
751 750 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
752 751 }
753 752 }
754 753 }
755 754 }
756 755 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock
757 756 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
758 757 // LOAD_INSTANCE in parallel
759 758
760 759 if (!throw_circularity_error && !class_has_been_loaded) {
761 760 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
762 761 load_instance_added = true;
763 762 // For class loaders that do not acquire the classloader object lock,
764 763 // if they did not catch another thread holding LOAD_INSTANCE,
765 764 // need a check analogous to the acquire ObjectLocker/find_class
766 765 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
767 766 // one final check if the load has already completed
768 767 // class loaders holding the ObjectLock shouldn't find the class here
769 768 Klass* check = find_class(d_index, d_hash, name, loader_data);
770 769 if (check != NULL) {
771 770 // Klass is already loaded, so return it after checking/adding protection domain
772 771 k = instanceKlassHandle(THREAD, check);
773 772 class_has_been_loaded = true;
774 773 }
775 774 }
776 775 }
777 776
778 777 // must throw error outside of owning lock
779 778 if (throw_circularity_error) {
780 779 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
781 780 ResourceMark rm(THREAD);
782 781 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
783 782 }
784 783
785 784 if (!class_has_been_loaded) {
786 785
787 786 // Do actual loading
788 787 k = load_instance_class(name, class_loader, THREAD);
789 788
790 789 // For UnsyncloadClass only
791 790 // If they got a linkageError, check if a parallel class load succeeded.
792 791 // If it did, then for bytecode resolution the specification requires
793 792 // that we return the same result we did for the other thread, i.e. the
794 793 // successfully loaded InstanceKlass
795 794 // Should not get here for classloaders that support parallelism
796 795 // with the new cleaner mechanism, even with AllowParallelDefineClass
797 796 // Bootstrap goes through here to allow for an extra guarantee check
798 797 if (UnsyncloadClass || (class_loader.is_null())) {
799 798 if (k.is_null() && HAS_PENDING_EXCEPTION
800 799 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
801 800 MutexLocker mu(SystemDictionary_lock, THREAD);
802 801 Klass* check = find_class(d_index, d_hash, name, loader_data);
803 802 if (check != NULL) {
804 803 // Klass is already loaded, so just use it
805 804 k = instanceKlassHandle(THREAD, check);
806 805 CLEAR_PENDING_EXCEPTION;
807 806 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
808 807 }
809 808 }
810 809 }
811 810
812 811 // If everything was OK (no exceptions, no null return value), and
813 812 // class_loader is NOT the defining loader, do a little more bookkeeping.
814 813 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
815 814 k->class_loader() != class_loader()) {
816 815
817 816 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
818 817
819 818 // Need to check for a PENDING_EXCEPTION again; check_constraints
820 819 // can throw and doesn't use the CHECK macro.
821 820 if (!HAS_PENDING_EXCEPTION) {
822 821 { // Grabbing the Compile_lock prevents systemDictionary updates
823 822 // during compilations.
824 823 MutexLocker mu(Compile_lock, THREAD);
825 824 update_dictionary(d_index, d_hash, p_index, p_hash,
826 825 k, class_loader, THREAD);
827 826 }
828 827
829 828 if (JvmtiExport::should_post_class_load()) {
830 829 Thread *thread = THREAD;
831 830 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
832 831 JvmtiExport::post_class_load((JavaThread *) thread, k());
833 832 }
834 833 }
835 834 }
836 835 } // load_instance_class loop
837 836
838 837 if (load_instance_added == true) {
839 838 // clean up placeholder entries for LOAD_INSTANCE success or error
840 839 // This brackets the SystemDictionary updates for both defining
841 840 // and initiating loaders
842 841 MutexLocker mu(SystemDictionary_lock, THREAD);
843 842 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
844 843 SystemDictionary_lock->notify_all();
845 844 }
846 845 }
847 846
848 847 if (HAS_PENDING_EXCEPTION || k.is_null()) {
849 848 return NULL;
850 849 }
851 850
852 851 post_class_load_event(class_load_start_time, k, class_loader);
853 852
854 853 #ifdef ASSERT
855 854 {
856 855 ClassLoaderData* loader_data = k->class_loader_data();
857 856 MutexLocker mu(SystemDictionary_lock, THREAD);
858 857 Klass* kk = find_class(name, loader_data);
859 858 assert(kk == k(), "should be present in dictionary");
860 859 }
861 860 #endif
862 861
863 862 // return if the protection domain in NULL
864 863 if (protection_domain() == NULL) return k();
865 864
866 865 // Check the protection domain has the right access
867 866 {
868 867 MutexLocker mu(SystemDictionary_lock, THREAD);
869 868 // Note that we have an entry, and entries can be deleted only during GC,
870 869 // so we cannot allow GC to occur while we're holding this entry.
871 870 // We're using a No_Safepoint_Verifier to catch any place where we
872 871 // might potentially do a GC at all.
873 872 // Dictionary::do_unloading() asserts that classes in SD are only
874 873 // unloaded at a safepoint. Anonymous classes are not in SD.
875 874 No_Safepoint_Verifier nosafepoint;
876 875 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
877 876 loader_data,
878 877 protection_domain)) {
879 878 return k();
880 879 }
881 880 }
882 881
883 882 // Verify protection domain. If it fails an exception is thrown
884 883 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
885 884
886 885 return k();
887 886 }
888 887
889 888
890 889 // This routine does not lock the system dictionary.
891 890 //
892 891 // Since readers don't hold a lock, we must make sure that system
893 892 // dictionary entries are only removed at a safepoint (when only one
894 893 // thread is running), and are added to in a safe way (all links must
895 894 // be updated in an MT-safe manner).
896 895 //
897 896 // Callers should be aware that an entry could be added just after
898 897 // _dictionary->bucket(index) is read here, so the caller will not see
899 898 // the new entry.
900 899
901 900 Klass* SystemDictionary::find(Symbol* class_name,
902 901 Handle class_loader,
903 902 Handle protection_domain,
904 903 TRAPS) {
905 904
906 905 // UseNewReflection
907 906 // The result of this call should be consistent with the result
908 907 // of the call to resolve_instance_class_or_null().
909 908 // See evaluation 6790209 and 4474172 for more details.
910 909 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
911 910 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
912 911
913 912 if (loader_data == NULL) {
914 913 // If the ClassLoaderData has not been setup,
915 914 // then the class loader has no entries in the dictionary.
916 915 return NULL;
917 916 }
918 917
919 918 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
920 919 int d_index = dictionary()->hash_to_index(d_hash);
921 920
922 921 {
923 922 // Note that we have an entry, and entries can be deleted only during GC,
924 923 // so we cannot allow GC to occur while we're holding this entry.
925 924 // We're using a No_Safepoint_Verifier to catch any place where we
926 925 // might potentially do a GC at all.
927 926 // Dictionary::do_unloading() asserts that classes in SD are only
928 927 // unloaded at a safepoint. Anonymous classes are not in SD.
929 928 No_Safepoint_Verifier nosafepoint;
930 929 return dictionary()->find(d_index, d_hash, class_name, loader_data,
931 930 protection_domain, THREAD);
932 931 }
933 932 }
934 933
935 934
936 935 // Look for a loaded instance or array klass by name. Do not do any loading.
937 936 // return NULL in case of error.
938 937 Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
939 938 Handle class_loader,
940 939 Handle protection_domain,
941 940 TRAPS) {
942 941 Klass* k = NULL;
943 942 assert(class_name != NULL, "class name must be non NULL");
944 943
945 944 if (FieldType::is_array(class_name)) {
946 945 // The name refers to an array. Parse the name.
947 946 // dimension and object_key in FieldArrayInfo are assigned as a
948 947 // side-effect of this call
949 948 FieldArrayInfo fd;
950 949 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
951 950 if (t != T_OBJECT) {
952 951 k = Universe::typeArrayKlassObj(t);
953 952 } else {
954 953 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
955 954 }
956 955 if (k != NULL) {
957 956 k = k->array_klass_or_null(fd.dimension());
958 957 }
959 958 } else {
960 959 k = find(class_name, class_loader, protection_domain, THREAD);
961 960 }
962 961 return k;
963 962 }
964 963
965 964 // Note: this method is much like resolve_from_stream, but
966 965 // updates no supplemental data structures.
967 966 // TODO consolidate the two methods with a helper routine?
968 967 Klass* SystemDictionary::parse_stream(Symbol* class_name,
969 968 Handle class_loader,
970 969 Handle protection_domain,
971 970 ClassFileStream* st,
972 971 KlassHandle host_klass,
973 972 GrowableArray<Handle>* cp_patches,
974 973 TRAPS) {
975 974 TempNewSymbol parsed_name = NULL;
976 975
977 976 Ticks class_load_start_time = Ticks::now();
978 977
979 978 ClassLoaderData* loader_data;
980 979 if (host_klass.not_null()) {
981 980 // Create a new CLD for anonymous class, that uses the same class loader
982 981 // as the host_klass
983 982 assert(EnableInvokeDynamic, "");
984 983 guarantee(host_klass->class_loader() == class_loader(), "should be the same");
985 984 guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping");
986 985 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
987 986 loader_data->record_dependency(host_klass(), CHECK_NULL);
988 987 } else {
989 988 loader_data = ClassLoaderData::class_loader_data(class_loader());
990 989 }
991 990
992 991 // Parse the stream. Note that we do this even though this klass might
993 992 // already be present in the SystemDictionary, otherwise we would not
994 993 // throw potential ClassFormatErrors.
995 994 //
996 995 // Note: "name" is updated.
997 996
998 997 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
999 998 loader_data,
1000 999 protection_domain,
1001 1000 host_klass,
1002 1001 cp_patches,
1003 1002 parsed_name,
1004 1003 true,
1005 1004 THREAD);
1006 1005
1007 1006
1008 1007 if (host_klass.not_null() && k.not_null()) {
1009 1008 assert(EnableInvokeDynamic, "");
1010 1009 // If it's anonymous, initialize it now, since nobody else will.
1011 1010
1012 1011 {
1013 1012 MutexLocker mu_r(Compile_lock, THREAD);
1014 1013
1015 1014 // Add to class hierarchy, initialize vtables, and do possible
1016 1015 // deoptimizations.
1017 1016 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
1018 1017
1019 1018 // But, do not add to system dictionary.
1020 1019
1021 1020 // compiled code dependencies need to be validated anyway
1022 1021 notice_modification();
1023 1022 }
1024 1023
1025 1024 // Rewrite and patch constant pool here.
1026 1025 k->link_class(CHECK_NULL);
1027 1026 if (cp_patches != NULL) {
1028 1027 k->constants()->patch_resolved_references(cp_patches);
1029 1028 }
1030 1029 k->eager_initialize(CHECK_NULL);
1031 1030
1032 1031 // notify jvmti
1033 1032 if (JvmtiExport::should_post_class_load()) {
1034 1033 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1035 1034 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1036 1035 }
1037 1036
1038 1037 post_class_load_event(class_load_start_time, k, class_loader);
1039 1038 }
1040 1039 assert(host_klass.not_null() || cp_patches == NULL,
1041 1040 "cp_patches only found with host_klass");
1042 1041
1043 1042 return k();
1044 1043 }
1045 1044
1046 1045 // Add a klass to the system from a stream (called by jni_DefineClass and
1047 1046 // JVM_DefineClass).
1048 1047 // Note: class_name can be NULL. In that case we do not know the name of
1049 1048 // the class until we have parsed the stream.
1050 1049
1051 1050 Klass* SystemDictionary::resolve_from_stream(Symbol* class_name,
1052 1051 Handle class_loader,
1053 1052 Handle protection_domain,
1054 1053 ClassFileStream* st,
1055 1054 bool verify,
1056 1055 TRAPS) {
1057 1056
1058 1057 // Classloaders that support parallelism, e.g. bootstrap classloader,
1059 1058 // or all classloaders with UnsyncloadClass do not acquire lock here
1060 1059 bool DoObjectLock = true;
1061 1060 if (is_parallelCapable(class_loader)) {
1062 1061 DoObjectLock = false;
1063 1062 }
1064 1063
1065 1064 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
1066 1065
1067 1066 // Make sure we are synchronized on the class loader before we proceed
1068 1067 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1069 1068 check_loader_lock_contention(lockObject, THREAD);
1070 1069 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
1071 1070
1072 1071 TempNewSymbol parsed_name = NULL;
1073 1072
1074 1073 // Parse the stream. Note that we do this even though this klass might
1075 1074 // already be present in the SystemDictionary, otherwise we would not
1076 1075 // throw potential ClassFormatErrors.
1077 1076 //
1078 1077 // Note: "name" is updated.
1079 1078
1080 1079 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
1081 1080 loader_data,
1082 1081 protection_domain,
1083 1082 parsed_name,
1084 1083 verify,
1085 1084 THREAD);
1086 1085
1087 1086 const char* pkg = "java/";
1088 1087 if (!HAS_PENDING_EXCEPTION &&
1089 1088 !class_loader.is_null() &&
1090 1089 parsed_name != NULL &&
1091 1090 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
1092 1091 // It is illegal to define classes in the "java." package from
1093 1092 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
1094 1093 ResourceMark rm(THREAD);
1095 1094 char* name = parsed_name->as_C_string();
1096 1095 char* index = strrchr(name, '/');
1097 1096 *index = '\0'; // chop to just the package name
1098 1097 while ((index = strchr(name, '/')) != NULL) {
1099 1098 *index = '.'; // replace '/' with '.' in package name
1100 1099 }
1101 1100 const char* fmt = "Prohibited package name: %s";
1102 1101 size_t len = strlen(fmt) + strlen(name);
1103 1102 char* message = NEW_RESOURCE_ARRAY(char, len);
1104 1103 jio_snprintf(message, len, fmt, name);
1105 1104 Exceptions::_throw_msg(THREAD_AND_LOCATION,
1106 1105 vmSymbols::java_lang_SecurityException(), message);
1107 1106 }
1108 1107
1109 1108 if (!HAS_PENDING_EXCEPTION) {
1110 1109 assert(parsed_name != NULL, "Sanity");
1111 1110 assert(class_name == NULL || class_name == parsed_name, "name mismatch");
1112 1111 // Verification prevents us from creating names with dots in them, this
1113 1112 // asserts that that's the case.
1114 1113 assert(is_internal_format(parsed_name),
1115 1114 "external class name format used internally");
1116 1115
1117 1116 // Add class just loaded
1118 1117 // If a class loader supports parallel classloading handle parallel define requests
1119 1118 // find_or_define_instance_class may return a different InstanceKlass
1120 1119 if (is_parallelCapable(class_loader)) {
1121 1120 k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
1122 1121 } else {
1123 1122 define_instance_class(k, THREAD);
1124 1123 }
1125 1124 }
1126 1125
1127 1126 // Make sure we have an entry in the SystemDictionary on success
1128 1127 debug_only( {
1129 1128 if (!HAS_PENDING_EXCEPTION) {
1130 1129 assert(parsed_name != NULL, "parsed_name is still null?");
1131 1130 Symbol* h_name = k->name();
1132 1131 ClassLoaderData *defining_loader_data = k->class_loader_data();
1133 1132
1134 1133 MutexLocker mu(SystemDictionary_lock, THREAD);
1135 1134
1136 1135 Klass* check = find_class(parsed_name, loader_data);
1137 1136 assert(check == k(), "should be present in the dictionary");
1138 1137
1139 1138 Klass* check2 = find_class(h_name, defining_loader_data);
1140 1139 assert(check == check2, "name inconsistancy in SystemDictionary");
1141 1140 }
1142 1141 } );
1143 1142
1144 1143 return k();
1145 1144 }
1146 1145
1147 1146 #if INCLUDE_CDS
1148 1147 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
1149 1148 int number_of_entries) {
1150 1149 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
1151 1150 "bad shared dictionary size.");
1152 1151 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
1153 1152 }
1154 1153
1155 1154
1156 1155 // If there is a shared dictionary, then find the entry for the
1157 1156 // given shared system class, if any.
1158 1157
1159 1158 Klass* SystemDictionary::find_shared_class(Symbol* class_name) {
1160 1159 if (shared_dictionary() != NULL) {
1161 1160 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
1162 1161 int d_index = shared_dictionary()->hash_to_index(d_hash);
1163 1162
1164 1163 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
1165 1164 } else {
1166 1165 return NULL;
1167 1166 }
1168 1167 }
1169 1168
1170 1169
1171 1170 // Load a class from the shared spaces (found through the shared system
1172 1171 // dictionary). Force the superclass and all interfaces to be loaded.
1173 1172 // Update the class definition to include sibling classes and no
1174 1173 // subclasses (yet). [Classes in the shared space are not part of the
1175 1174 // object hierarchy until loaded.]
1176 1175
1177 1176 instanceKlassHandle SystemDictionary::load_shared_class(
1178 1177 Symbol* class_name, Handle class_loader, TRAPS) {
1179 1178 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
1180 1179 // Make sure we only return the boot class for the NULL classloader.
1181 1180 if (ik.not_null() &&
1182 1181 SharedClassUtil::is_shared_boot_class(ik()) && class_loader.is_null()) {
1183 1182 Handle protection_domain;
1184 1183 return load_shared_class(ik, class_loader, protection_domain, THREAD);
1185 1184 }
1186 1185 return instanceKlassHandle();
1187 1186 }
1188 1187
1189 1188 instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
1190 1189 Handle class_loader,
1191 1190 Handle protection_domain, TRAPS) {
1192 1191 if (ik.not_null()) {
1193 1192 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1194 1193 Symbol* class_name = ik->name();
1195 1194
1196 1195 // Found the class, now load the superclass and interfaces. If they
1197 1196 // are shared, add them to the main system dictionary and reset
1198 1197 // their hierarchy references (supers, subs, and interfaces).
1199 1198
1200 1199 if (ik->super() != NULL) {
1201 1200 Symbol* cn = ik->super()->name();
1202 1201 resolve_super_or_fail(class_name, cn,
1203 1202 class_loader, protection_domain, true, CHECK_(nh));
1204 1203 }
1205 1204
1206 1205 Array<Klass*>* interfaces = ik->local_interfaces();
1207 1206 int num_interfaces = interfaces->length();
1208 1207 for (int index = 0; index < num_interfaces; index++) {
1209 1208 Klass* k = interfaces->at(index);
1210 1209
1211 1210 // Note: can not use InstanceKlass::cast here because
1212 1211 // interfaces' InstanceKlass's C++ vtbls haven't been
1213 1212 // reinitialized yet (they will be once the interface classes
1214 1213 // are loaded)
1215 1214 Symbol* name = k->name();
1216 1215 resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
1217 1216 }
1218 1217
1219 1218 // Adjust methods to recover missing data. They need addresses for
1220 1219 // interpreter entry points and their default native method address
1221 1220 // must be reset.
1222 1221
1223 1222 // Updating methods must be done under a lock so multiple
1224 1223 // threads don't update these in parallel
1225 1224 //
1226 1225 // Shared classes are all currently loaded by either the bootstrap or
1227 1226 // internal parallel class loaders, so this will never cause a deadlock
1228 1227 // on a custom class loader lock.
1229 1228
1230 1229 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1231 1230 {
1232 1231 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
1233 1232 check_loader_lock_contention(lockObject, THREAD);
1234 1233 ObjectLocker ol(lockObject, THREAD, true);
1235 1234 ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh));
1236 1235 }
1237 1236
1238 1237 if (TraceClassLoading) {
1239 1238 ResourceMark rm;
1240 1239 tty->print("[Loaded %s", ik->external_name());
1241 1240 tty->print(" from shared objects file");
1242 1241 if (class_loader.not_null()) {
1243 1242 tty->print(" by %s", loader_data->loader_name());
1244 1243 }
1245 1244 tty->print_cr("]");
1246 1245 }
1247 1246
1248 1247 if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
1249 1248 // Only dump the classes that can be stored into CDS archive
1250 1249 if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
1251 1250 ResourceMark rm(THREAD);
1252 1251 classlist_file->print_cr("%s", ik->name()->as_C_string());
1253 1252 classlist_file->flush();
1254 1253 }
1255 1254 }
1256 1255
1257 1256 // notify a class loaded from shared object
1258 1257 ClassLoadingService::notify_class_loaded(InstanceKlass::cast(ik()),
1259 1258 true /* shared class */);
1260 1259 }
1261 1260 return ik;
1262 1261 }
1263 1262 #endif // INCLUDE_CDS
1264 1263
1265 1264 instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
1266 1265 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1267 1266 if (class_loader.is_null()) {
1268 1267
1269 1268 // Search the shared system dictionary for classes preloaded into the
1270 1269 // shared spaces.
1271 1270 instanceKlassHandle k;
1272 1271 {
1273 1272 #if INCLUDE_CDS
1274 1273 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
1275 1274 k = load_shared_class(class_name, class_loader, THREAD);
1276 1275 #endif
1277 1276 }
1278 1277
1279 1278 if (k.is_null()) {
1280 1279 // Use VM class loader
1281 1280 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
1282 1281 k = ClassLoader::load_classfile(class_name, CHECK_(nh));
1283 1282 }
1284 1283
1285 1284 // find_or_define_instance_class may return a different InstanceKlass
1286 1285 if (!k.is_null()) {
1287 1286 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
1288 1287 }
1289 1288 return k;
1290 1289 } else {
1291 1290 // Use user specified class loader to load class. Call loadClass operation on class_loader.
1292 1291 ResourceMark rm(THREAD);
1293 1292
1294 1293 assert(THREAD->is_Java_thread(), "must be a JavaThread");
1295 1294 JavaThread* jt = (JavaThread*) THREAD;
1296 1295
1297 1296 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
1298 1297 ClassLoader::perf_app_classload_selftime(),
1299 1298 ClassLoader::perf_app_classload_count(),
1300 1299 jt->get_thread_stat()->perf_recursion_counts_addr(),
1301 1300 jt->get_thread_stat()->perf_timers_addr(),
1302 1301 PerfClassTraceTime::CLASS_LOAD);
1303 1302
1304 1303 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
1305 1304 // Translate to external class name format, i.e., convert '/' chars to '.'
1306 1305 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
1307 1306
1308 1307 JavaValue result(T_OBJECT);
1309 1308
1310 1309 KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass());
1311 1310
1312 1311 // Call public unsynchronized loadClass(String) directly for all class loaders
1313 1312 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
1314 1313 // acquire a class-name based lock rather than the class loader object lock.
1315 1314 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
1316 1315 // so the call to loadClassInternal() was not required.
1317 1316 //
1318 1317 // UnsyncloadClass flag means both call loadClass(String) and do
1319 1318 // not acquire the class loader lock even for class loaders that are
1320 1319 // not parallelCapable. This was a risky transitional
1321 1320 // flag for diagnostic purposes only. It is risky to call
1322 1321 // custom class loaders without synchronization.
1323 1322 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
1324 1323 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
1325 1324 // Do NOT assume this will be supported in future releases.
1326 1325 //
1327 1326 // Added MustCallLoadClassInternal in case we discover in the field
1328 1327 // a customer that counts on this call
1329 1328 if (MustCallLoadClassInternal && has_loadClassInternal()) {
1330 1329 JavaCalls::call_special(&result,
1331 1330 class_loader,
1332 1331 spec_klass,
1333 1332 vmSymbols::loadClassInternal_name(),
1334 1333 vmSymbols::string_class_signature(),
1335 1334 string,
1336 1335 CHECK_(nh));
1337 1336 } else {
1338 1337 JavaCalls::call_virtual(&result,
1339 1338 class_loader,
1340 1339 spec_klass,
1341 1340 vmSymbols::loadClass_name(),
1342 1341 vmSymbols::string_class_signature(),
1343 1342 string,
1344 1343 CHECK_(nh));
1345 1344 }
1346 1345
1347 1346 assert(result.get_type() == T_OBJECT, "just checking");
1348 1347 oop obj = (oop) result.get_jobject();
1349 1348
1350 1349 // Primitive classes return null since forName() can not be
1351 1350 // used to obtain any of the Class objects representing primitives or void
1352 1351 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
1353 1352 instanceKlassHandle k =
1354 1353 instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj));
1355 1354 // For user defined Java class loaders, check that the name returned is
1356 1355 // the same as that requested. This check is done for the bootstrap
1357 1356 // loader when parsing the class file.
1358 1357 if (class_name == k->name()) {
1359 1358 return k;
1360 1359 }
1361 1360 }
1362 1361 // Class is not found or has the wrong name, return NULL
1363 1362 return nh;
1364 1363 }
1365 1364 }
1366 1365
1367 1366 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
1368 1367
1369 1368 ClassLoaderData* loader_data = k->class_loader_data();
1370 1369 Handle class_loader_h(THREAD, loader_data->class_loader());
1371 1370
1372 1371 for (uintx it = 0; it < GCExpandToAllocateDelayMillis; it++){}
1373 1372
1374 1373 // for bootstrap and other parallel classloaders don't acquire lock,
1375 1374 // use placeholder token
1376 1375 // If a parallelCapable class loader calls define_instance_class instead of
1377 1376 // find_or_define_instance_class to get here, we have a timing
1378 1377 // hole with systemDictionary updates and check_constraints
1379 1378 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
1380 1379 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
1381 1380 compute_loader_lock_object(class_loader_h, THREAD)),
1382 1381 "define called without lock");
1383 1382 }
1384 1383
1385 1384 // Check class-loading constraints. Throw exception if violation is detected.
1386 1385 // Grabs and releases SystemDictionary_lock
1387 1386 // The check_constraints/find_class call and update_dictionary sequence
1388 1387 // must be "atomic" for a specific class/classloader pair so we never
1389 1388 // define two different instanceKlasses for that class/classloader pair.
1390 1389 // Existing classloaders will call define_instance_class with the
1391 1390 // classloader lock held
1392 1391 // Parallel classloaders will call find_or_define_instance_class
1393 1392 // which will require a token to perform the define class
1394 1393 Symbol* name_h = k->name();
1395 1394 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1396 1395 int d_index = dictionary()->hash_to_index(d_hash);
1397 1396 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
1398 1397
1399 1398 // Register class just loaded with class loader (placed in Vector)
1400 1399 // Note we do this before updating the dictionary, as this can
1401 1400 // fail with an OutOfMemoryError (if it does, we will *not* put this
1402 1401 // class in the dictionary and will not update the class hierarchy).
1403 1402 // JVMTI FollowReferences needs to find the classes this way.
1404 1403 if (k->class_loader() != NULL) {
1405 1404 methodHandle m(THREAD, Universe::loader_addClass_method());
1406 1405 JavaValue result(T_VOID);
1407 1406 JavaCallArguments args(class_loader_h);
1408 1407 args.push_oop(Handle(THREAD, k->java_mirror()));
1409 1408 JavaCalls::call(&result, m, &args, CHECK);
1410 1409 }
1411 1410
1412 1411 // Add the new class. We need recompile lock during update of CHA.
1413 1412 {
1414 1413 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1415 1414 int p_index = placeholders()->hash_to_index(p_hash);
1416 1415
1417 1416 MutexLocker mu_r(Compile_lock, THREAD);
1418 1417
1419 1418 // Add to class hierarchy, initialize vtables, and do possible
1420 1419 // deoptimizations.
1421 1420 add_to_hierarchy(k, CHECK); // No exception, but can block
1422 1421
1423 1422 // Add to systemDictionary - so other classes can see it.
1424 1423 // Grabs and releases SystemDictionary_lock
1425 1424 update_dictionary(d_index, d_hash, p_index, p_hash,
1426 1425 k, class_loader_h, THREAD);
1427 1426 }
1428 1427 k->eager_initialize(THREAD);
1429 1428
1430 1429 // notify jvmti
1431 1430 if (JvmtiExport::should_post_class_load()) {
1432 1431 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
1433 1432 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
1434 1433
1435 1434 }
1436 1435
1437 1436 }
1438 1437
1439 1438 // Support parallel classloading
1440 1439 // All parallel class loaders, including bootstrap classloader
1441 1440 // lock a placeholder entry for this class/class_loader pair
1442 1441 // to allow parallel defines of different classes for this class loader
1443 1442 // With AllowParallelDefine flag==true, in case they do not synchronize around
1444 1443 // FindLoadedClass/DefineClass, calls, we check for parallel
1445 1444 // loading for them, wait if a defineClass is in progress
1446 1445 // and return the initial requestor's results
1447 1446 // This flag does not apply to the bootstrap classloader.
1448 1447 // With AllowParallelDefine flag==false, call through to define_instance_class
1449 1448 // which will throw LinkageError: duplicate class definition.
1450 1449 // False is the requested default.
1451 1450 // For better performance, the class loaders should synchronize
1452 1451 // findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
1453 1452 // potentially waste time reading and parsing the bytestream.
1454 1453 // Note: VM callers should ensure consistency of k/class_name,class_loader
1455 1454 instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
1456 1455
1457 1456 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
1458 1457 Symbol* name_h = k->name(); // passed in class_name may be null
1459 1458 ClassLoaderData* loader_data = class_loader_data(class_loader);
1460 1459
1461 1460 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
1462 1461 int d_index = dictionary()->hash_to_index(d_hash);
1463 1462
1464 1463 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
1465 1464 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
1466 1465 int p_index = placeholders()->hash_to_index(p_hash);
1467 1466 PlaceholderEntry* probe;
1468 1467
1469 1468 {
1470 1469 MutexLocker mu(SystemDictionary_lock, THREAD);
1471 1470 // First check if class already defined
1472 1471 if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
1473 1472 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1474 1473 if (check != NULL) {
1475 1474 return(instanceKlassHandle(THREAD, check));
1476 1475 }
1477 1476 }
1478 1477
1479 1478 // Acquire define token for this class/classloader
1480 1479 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
1481 1480 // Wait if another thread defining in parallel
1482 1481 // All threads wait - even those that will throw duplicate class: otherwise
1483 1482 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails
1484 1483 // if other thread has not finished updating dictionary
1485 1484 while (probe->definer() != NULL) {
1486 1485 SystemDictionary_lock->wait();
1487 1486 }
1488 1487 // Only special cases allow parallel defines and can use other thread's results
1489 1488 // Other cases fall through, and may run into duplicate defines
1490 1489 // caught by finding an entry in the SystemDictionary
1491 1490 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
1492 1491 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1493 1492 SystemDictionary_lock->notify_all();
1494 1493 #ifdef ASSERT
1495 1494 Klass* check = find_class(d_index, d_hash, name_h, loader_data);
1496 1495 assert(check != NULL, "definer missed recording success");
1497 1496 #endif
1498 1497 return(instanceKlassHandle(THREAD, probe->instance_klass()));
1499 1498 } else {
1500 1499 // This thread will define the class (even if earlier thread tried and had an error)
1501 1500 probe->set_definer(THREAD);
1502 1501 }
1503 1502 }
1504 1503
1505 1504 define_instance_class(k, THREAD);
1506 1505
1507 1506 Handle linkage_exception = Handle(); // null handle
1508 1507
1509 1508 // definer must notify any waiting threads
1510 1509 {
1511 1510 MutexLocker mu(SystemDictionary_lock, THREAD);
1512 1511 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
1513 1512 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
1514 1513 if (probe != NULL) {
1515 1514 if (HAS_PENDING_EXCEPTION) {
1516 1515 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
1517 1516 CLEAR_PENDING_EXCEPTION;
1518 1517 } else {
1519 1518 probe->set_instance_klass(k());
1520 1519 }
1521 1520 probe->set_definer(NULL);
1522 1521 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
1523 1522 SystemDictionary_lock->notify_all();
1524 1523 }
1525 1524 }
1526 1525
1527 1526 // Can't throw exception while holding lock due to rank ordering
1528 1527 if (linkage_exception() != NULL) {
1529 1528 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
1530 1529 }
1531 1530
1532 1531 return k;
1533 1532 }
1534 1533 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
1535 1534 // If class_loader is NULL we synchronize on _system_loader_lock_obj
1536 1535 if (class_loader.is_null()) {
1537 1536 return Handle(THREAD, _system_loader_lock_obj);
1538 1537 } else {
1539 1538 return class_loader;
1540 1539 }
1541 1540 }
1542 1541
1543 1542 // This method is added to check how often we have to wait to grab loader
1544 1543 // lock. The results are being recorded in the performance counters defined in
1545 1544 // ClassLoader::_sync_systemLoaderLockContentionRate and
1546 1545 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
1547 1546 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
1548 1547 if (!UsePerfData) {
1549 1548 return;
1550 1549 }
1551 1550
1552 1551 assert(!loader_lock.is_null(), "NULL lock object");
1553 1552
1554 1553 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
1555 1554 == ObjectSynchronizer::owner_other) {
1556 1555 // contention will likely happen, so increment the corresponding
1557 1556 // contention counter.
1558 1557 if (loader_lock() == _system_loader_lock_obj) {
1559 1558 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
1560 1559 } else {
1561 1560 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
1562 1561 }
1563 1562 }
1564 1563 }
1565 1564
1566 1565 // ----------------------------------------------------------------------------
1567 1566 // Lookup
1568 1567
1569 1568 Klass* SystemDictionary::find_class(int index, unsigned int hash,
1570 1569 Symbol* class_name,
1571 1570 ClassLoaderData* loader_data) {
1572 1571 assert_locked_or_safepoint(SystemDictionary_lock);
1573 1572 assert (index == dictionary()->index_for(class_name, loader_data),
1574 1573 "incorrect index?");
1575 1574
1576 1575 Klass* k = dictionary()->find_class(index, hash, class_name, loader_data);
1577 1576 return k;
1578 1577 }
1579 1578
1580 1579
1581 1580 // Basic find on classes in the midst of being loaded
1582 1581 Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
1583 1582 ClassLoaderData* loader_data) {
1584 1583 assert_locked_or_safepoint(SystemDictionary_lock);
1585 1584 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
1586 1585 int p_index = placeholders()->hash_to_index(p_hash);
1587 1586 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
1588 1587 }
1589 1588
1590 1589
1591 1590 // Used for assertions and verification only
1592 1591 Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
1593 1592 #ifndef ASSERT
1594 1593 guarantee(VerifyBeforeGC ||
1595 1594 VerifyDuringGC ||
1596 1595 VerifyBeforeExit ||
1597 1596 VerifyDuringStartup ||
1598 1597 VerifyAfterGC, "too expensive");
1599 1598 #endif
1600 1599 assert_locked_or_safepoint(SystemDictionary_lock);
1601 1600
1602 1601 // First look in the loaded class array
1603 1602 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
1604 1603 int d_index = dictionary()->hash_to_index(d_hash);
1605 1604 return find_class(d_index, d_hash, class_name, loader_data);
1606 1605 }
1607 1606
1608 1607
1609 1608 // Get the next class in the diictionary.
1610 1609 Klass* SystemDictionary::try_get_next_class() {
1611 1610 return dictionary()->try_get_next_class();
1612 1611 }
1613 1612
1614 1613
1615 1614 // ----------------------------------------------------------------------------
1616 1615 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
1617 1616 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
1618 1617 // before a new class is used.
1619 1618
1620 1619 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
1621 1620 assert(k.not_null(), "just checking");
1622 1621 assert_locked_or_safepoint(Compile_lock);
1623 1622
1624 1623 // Link into hierachy. Make sure the vtables are initialized before linking into
1625 1624 k->append_to_sibling_list(); // add to superklass/sibling list
1626 1625 k->process_interfaces(THREAD); // handle all "implements" declarations
1627 1626 k->set_init_state(InstanceKlass::loaded);
1628 1627 // Now flush all code that depended on old class hierarchy.
1629 1628 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1630 1629 // Also, first reinitialize vtable because it may have gotten out of synch
1631 1630 // while the new class wasn't connected to the class hierarchy.
1632 1631 Universe::flush_dependents_on(k);
1633 1632 }
1634 1633
1635 1634 // ----------------------------------------------------------------------------
1636 1635 // GC support
1637 1636
1638 1637 // Following roots during mark-sweep is separated in two phases.
1639 1638 //
1640 1639 // The first phase follows preloaded classes and all other system
1641 1640 // classes, since these will never get unloaded anyway.
1642 1641 //
1643 1642 // The second phase removes (unloads) unreachable classes from the
1644 1643 // system dictionary and follows the remaining classes' contents.
1645 1644
1646 1645 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
1647 1646 roots_oops_do(blk, NULL);
1648 1647 }
1649 1648
1650 1649 void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
1651 1650 // Follow all system classes and temporary placeholders in dictionary
1652 1651 dictionary()->always_strong_classes_do(closure);
1653 1652
1654 1653 // Placeholders. These represent classes we're actively loading.
1655 1654 placeholders()->classes_do(closure);
1656 1655 }
1657 1656
1658 1657 // Calculate a "good" systemdictionary size based
1659 1658 // on predicted or current loaded classes count
1660 1659 int SystemDictionary::calculate_systemdictionary_size(int classcount) {
1661 1660 int newsize = _old_default_sdsize;
1662 1661 if ((classcount > 0) && !DumpSharedSpaces) {
1663 1662 int desiredsize = classcount/_average_depth_goal;
1664 1663 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
1665 1664 newsize = _primelist[++_sdgeneration]) {
1666 1665 if (desiredsize <= newsize) {
1667 1666 break;
1668 1667 }
1669 1668 }
1670 1669 }
1671 1670 return newsize;
1672 1671 }
1673 1672
1674 1673 #ifdef ASSERT
1675 1674 class VerifySDReachableAndLiveClosure : public OopClosure {
1676 1675 private:
1677 1676 BoolObjectClosure* _is_alive;
1678 1677
1679 1678 template <class T> void do_oop_work(T* p) {
1680 1679 oop obj = oopDesc::load_decode_heap_oop(p);
1681 1680 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
1682 1681 }
1683 1682
1684 1683 public:
1685 1684 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
1686 1685
1687 1686 virtual void do_oop(oop* p) { do_oop_work(p); }
1688 1687 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1689 1688 };
1690 1689 #endif
1691 1690
1692 1691 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
1693 1692 // Note: anonymous classes are not in the SD.
1694 1693 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive, bool clean_alive) {
1695 1694 // First, mark for unload all ClassLoaderData referencing a dead class loader.
1696 1695 bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive, clean_alive);
1697 1696 if (unloading_occurred) {
1698 1697 dictionary()->do_unloading();
1699 1698 constraints()->purge_loader_constraints();
1700 1699 resolution_errors()->purge_resolution_errors();
1701 1700 }
1702 1701 // Oops referenced by the system dictionary may get unreachable independently
1703 1702 // of the class loader (eg. cached protection domain oops). So we need to
1704 1703 // explicitly unlink them here instead of in Dictionary::do_unloading.
1705 1704 dictionary()->unlink(is_alive);
1706 1705 #ifdef ASSERT
1707 1706 VerifySDReachableAndLiveClosure cl(is_alive);
1708 1707 dictionary()->oops_do(&cl);
1709 1708 #endif
1710 1709 return unloading_occurred;
1711 1710 }
1712 1711
1713 1712 void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
1714 1713 strong->do_oop(&_java_system_loader);
1715 1714 strong->do_oop(&_system_loader_lock_obj);
1716 1715 CDS_ONLY(SystemDictionaryShared::roots_oops_do(strong);)
1717 1716
1718 1717 // Adjust dictionary
1719 1718 dictionary()->roots_oops_do(strong, weak);
1720 1719
1721 1720 // Visit extra methods
1722 1721 invoke_method_table()->oops_do(strong);
1723 1722 }
1724 1723
1725 1724 void SystemDictionary::oops_do(OopClosure* f) {
1726 1725 f->do_oop(&_java_system_loader);
1727 1726 f->do_oop(&_system_loader_lock_obj);
1728 1727 CDS_ONLY(SystemDictionaryShared::oops_do(f);)
1729 1728
1730 1729 // Adjust dictionary
1731 1730 dictionary()->oops_do(f);
1732 1731
1733 1732 // Visit extra methods
1734 1733 invoke_method_table()->oops_do(f);
1735 1734 }
1736 1735
1737 1736 // Extended Class redefinition support.
1738 1737 // If one of these classes is replaced, we need to replace it in these places.
1739 1738 // KlassClosure::do_klass should take the address of a class but we can
1740 1739 // change that later.
1741 1740 void SystemDictionary::preloaded_classes_do(KlassClosure* f) {
1742 1741 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
1743 1742 f->do_klass(_well_known_klasses[k]);
1744 1743 }
1745 1744
1746 1745 {
1747 1746 for (int i = 0; i < T_VOID+1; i++) {
1748 1747 if (_box_klasses[i] != NULL) {
1749 1748 assert(i >= T_BOOLEAN, "checking");
1750 1749 f->do_klass(_box_klasses[i]);
1751 1750 }
1752 1751 }
1753 1752 }
1754 1753
1755 1754 FilteredFieldsMap::classes_do(f);
1756 1755 }
1757 1756
1758 1757 void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) {
1759 1758 f->do_klass(_abstract_ownable_synchronizer_klass);
1760 1759 }
1761 1760
1762 1761 // Just the classes from defining class loaders
1763 1762 // Don't iterate over placeholders
1764 1763 void SystemDictionary::classes_do(void f(Klass*)) {
1765 1764 dictionary()->classes_do(f);
1766 1765 }
1767 1766
1768 1767 // Added for initialize_itable_for_klass
1769 1768 // Just the classes from defining class loaders
1770 1769 // Don't iterate over placeholders
1771 1770 void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
1772 1771 dictionary()->classes_do(f, CHECK);
1773 1772 }
1774 1773
1775 1774 // All classes, and their class loaders
1776 1775 // Don't iterate over placeholders
1777 1776 void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
1778 1777 dictionary()->classes_do(f);
1779 1778 }
1780 1779
1781 1780 void SystemDictionary::placeholders_do(void f(Symbol*)) {
1782 1781 placeholders()->entries_do(f);
1783 1782 }
1784 1783
1785 1784 void SystemDictionary::methods_do(void f(Method*)) {
1786 1785 dictionary()->methods_do(f);
1787 1786 invoke_method_table()->methods_do(f);
1788 1787 }
1789 1788
1790 1789 void SystemDictionary::remove_classes_in_error_state() {
1791 1790 dictionary()->remove_classes_in_error_state();
1792 1791 }
1793 1792
1794 1793 // ----------------------------------------------------------------------------
1795 1794 // Lazily load klasses
1796 1795
1797 1796 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
1798 1797 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later");
1799 1798
1800 1799 // if multiple threads calling this function, only one thread will load
1801 1800 // the class. The other threads will find the loaded version once the
1802 1801 // class is loaded.
1803 1802 Klass* aos = _abstract_ownable_synchronizer_klass;
1804 1803 if (aos == NULL) {
1805 1804 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
1806 1805 // Force a fence to prevent any read before the write completes
1807 1806 OrderAccess::fence();
1808 1807 _abstract_ownable_synchronizer_klass = k;
1809 1808 }
1810 1809 }
1811 1810
1812 1811 // ----------------------------------------------------------------------------
1813 1812 // Initialization
1814 1813
1815 1814 void SystemDictionary::initialize(TRAPS) {
1816 1815 // Allocate arrays
1817 1816 assert(dictionary() == NULL,
1818 1817 "SystemDictionary should only be initialized once");
1819 1818 _sdgeneration = 0;
1820 1819 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
1821 1820 _placeholders = new PlaceholderTable(_nof_buckets);
1822 1821 _number_of_modifications = 0;
1823 1822 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
1824 1823 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
1825 1824 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
1826 1825
1827 1826 // Allocate private object used as system class loader lock
1828 1827 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
1829 1828 // Initialize basic classes
1830 1829 initialize_preloaded_classes(CHECK);
1831 1830 }
1832 1831
1833 1832 // Compact table of directions on the initialization of klasses:
1834 1833 static const short wk_init_info[] = {
1835 1834 #define WK_KLASS_INIT_INFO(name, symbol, option) \
1836 1835 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
1837 1836 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \
1838 1837 | (int)SystemDictionary::option ),
1839 1838 WK_KLASSES_DO(WK_KLASS_INIT_INFO)
1840 1839 #undef WK_KLASS_INIT_INFO
1841 1840 0
1842 1841 };
1843 1842
1844 1843 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
1845 1844 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1846 1845 int info = wk_init_info[id - FIRST_WKID];
1847 1846 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1848 1847 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
1849 1848 Klass** klassp = &_well_known_klasses[id];
1850 1849 bool must_load = (init_opt < SystemDictionary::Opt);
1851 1850 if ((*klassp) == NULL) {
1852 1851 if (must_load) {
1853 1852 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class
1854 1853 } else {
1855 1854 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass
1856 1855 }
1857 1856 }
1858 1857 return ((*klassp) != NULL);
1859 1858 }
1860 1859
1861 1860 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
1862 1861 assert((int)start_id <= (int)limit_id, "IDs are out of order!");
1863 1862 for (int id = (int)start_id; id < (int)limit_id; id++) {
1864 1863 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
1865 1864 int info = wk_init_info[id - FIRST_WKID];
1866 1865 int sid = (info >> CEIL_LG_OPTION_LIMIT);
1867 1866 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
1868 1867
1869 1868 initialize_wk_klass((WKID)id, opt, CHECK);
1870 1869 }
1871 1870
1872 1871 // move the starting value forward to the limit:
1873 1872 start_id = limit_id;
1874 1873 }
1875 1874
1876 1875 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
1877 1876 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
1878 1877 // Preload commonly used klasses
1879 1878 WKID scan = FIRST_WKID;
1880 1879 // first do Object, then String, Class
1881 1880 if (UseSharedSpaces) {
1882 1881 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
1883 1882 // Initialize the constant pool for the Object_class
1884 1883 InstanceKlass* ik = InstanceKlass::cast(Object_klass());
1885 1884 ik->constants()->restore_unshareable_info(CHECK);
1886 1885 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1887 1886 } else {
1888 1887 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
1889 1888 }
1890 1889
1891 1890 // Calculate offsets for String and Class classes since they are loaded and
1892 1891 // can be used after this point.
1893 1892 java_lang_String::compute_offsets();
1894 1893 java_lang_Class::compute_offsets();
1895 1894
1896 1895 // Fixup mirrors for classes loaded before java.lang.Class.
1897 1896 // These calls iterate over the objects currently in the perm gen
1898 1897 // so calling them at this point is matters (not before when there
1899 1898 // are fewer objects and not later after there are more objects
1900 1899 // in the perm gen.
1901 1900 Universe::initialize_basic_type_mirrors(CHECK);
1902 1901 Universe::fixup_mirrors(CHECK);
1903 1902
1904 1903 // do a bunch more:
1905 1904 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
1906 1905
1907 1906 // Preload ref klasses and set reference types
1908 1907 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
1909 1908 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
1910 1909
1911 1910 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
1912 1911 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
1913 1912 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
1914 1913 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
1915 1914 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
1916 1915
1917 1916 // JSR 292 classes
1918 1917 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
1919 1918 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
1920 1919 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
1921 1920 if (EnableInvokeDynamic) {
1922 1921 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
1923 1922 } else {
1924 1923 // Skip the JSR 292 classes, if not enabled.
1925 1924 scan = WKID(jsr292_group_end + 1);
1926 1925 }
1927 1926
1928 1927 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK);
1929 1928
1930 1929 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
1931 1930 _box_klasses[T_CHAR] = WK_KLASS(Character_klass);
1932 1931 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
1933 1932 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
1934 1933 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
1935 1934 _box_klasses[T_SHORT] = WK_KLASS(Short_klass);
1936 1935 _box_klasses[T_INT] = WK_KLASS(Integer_klass);
1937 1936 _box_klasses[T_LONG] = WK_KLASS(Long_klass);
1938 1937 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
1939 1938 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
1940 1939
1941 1940 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
1942 1941 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
1943 1942 _has_loadClassInternal = (method != NULL);
1944 1943 }
1945 1944 { // Compute whether we should use checkPackageAccess or NOT
1946 1945 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
1947 1946 _has_checkPackageAccess = (method != NULL);
1948 1947 }
1949 1948 }
1950 1949
1951 1950 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
1952 1951 // If so, returns the basic type it holds. If not, returns T_OBJECT.
1953 1952 BasicType SystemDictionary::box_klass_type(Klass* k) {
1954 1953 assert(k != NULL, "");
1955 1954 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
1956 1955 if (_box_klasses[i] == k)
1957 1956 return (BasicType)i;
1958 1957 }
1959 1958 return T_OBJECT;
1960 1959 }
1961 1960
1962 1961 // Constraints on class loaders. The details of the algorithm can be
1963 1962 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
1964 1963 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
1965 1964 // that the system dictionary needs to maintain a set of contraints that
1966 1965 // must be satisfied by all classes in the dictionary.
1967 1966 // if defining is true, then LinkageError if already in systemDictionary
1968 1967 // if initiating loader, then ok if InstanceKlass matches existing entry
1969 1968
1970 1969 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
1971 1970 instanceKlassHandle k,
1972 1971 Handle class_loader, bool defining,
1973 1972 TRAPS) {
1974 1973 const char *linkage_error = NULL;
1975 1974 {
1976 1975 Symbol* name = k->name();
1977 1976 ClassLoaderData *loader_data = class_loader_data(class_loader);
1978 1977
1979 1978 MutexLocker mu(SystemDictionary_lock, THREAD);
1980 1979
1981 1980 Klass* check = find_class(d_index, d_hash, name, loader_data);
1982 1981 if (check != (Klass*)NULL) {
1983 1982 // if different InstanceKlass - duplicate class definition,
1984 1983 // else - ok, class loaded by a different thread in parallel,
1985 1984 // we should only have found it if it was done loading and ok to use
1986 1985 // system dictionary only holds instance classes, placeholders
1987 1986 // also holds array classes
1988 1987
1989 1988 assert(check->oop_is_instance(), "noninstance in systemdictionary");
1990 1989 if ((defining == true) || (k() != check)) {
1991 1990 linkage_error = "loader (instance of %s): attempted duplicate class "
1992 1991 "definition for name: \"%s\"";
1993 1992 } else {
1994 1993 return;
1995 1994 }
1996 1995 }
1997 1996
1998 1997 #ifdef ASSERT
1999 1998 Symbol* ph_check = find_placeholder(name, loader_data);
2000 1999 assert(ph_check == NULL || ph_check == name, "invalid symbol");
2001 2000 #endif
2002 2001
2003 2002 if (linkage_error == NULL) {
2004 2003 if (constraints()->check_or_update(k, class_loader, name) == false) {
2005 2004 linkage_error = "loader constraint violation: loader (instance of %s)"
2006 2005 " previously initiated loading for a different type with name \"%s\"";
2007 2006 }
2008 2007 }
2009 2008 }
2010 2009
2011 2010 // Throw error now if needed (cannot throw while holding
2012 2011 // SystemDictionary_lock because of rank ordering)
2013 2012
2014 2013 if (linkage_error) {
2015 2014 ResourceMark rm(THREAD);
2016 2015 const char* class_loader_name = loader_name(class_loader());
2017 2016 char* type_name = k->name()->as_C_string();
2018 2017 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) +
2019 2018 strlen(type_name);
2020 2019 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
2021 2020 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name);
2022 2021 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
2023 2022 }
2024 2023 }
2025 2024
2026 2025
2027 2026 // Update system dictionary - done after check_constraint and add_to_hierachy
2028 2027 // have been called.
2029 2028 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
2030 2029 int p_index, unsigned int p_hash,
2031 2030 instanceKlassHandle k,
2032 2031 Handle class_loader,
2033 2032 TRAPS) {
2034 2033 // Compile_lock prevents systemDictionary updates during compilations
2035 2034 assert_locked_or_safepoint(Compile_lock);
2036 2035 Symbol* name = k->name();
2037 2036 ClassLoaderData *loader_data = class_loader_data(class_loader);
2038 2037
2039 2038 {
2040 2039 MutexLocker mu1(SystemDictionary_lock, THREAD);
2041 2040
2042 2041 // See whether biased locking is enabled and if so set it for this
2043 2042 // klass.
2044 2043 // Note that this must be done past the last potential blocking
2045 2044 // point / safepoint. We enable biased locking lazily using a
2046 2045 // VM_Operation to iterate the SystemDictionary and installing the
2047 2046 // biasable mark word into each InstanceKlass's prototype header.
2048 2047 // To avoid race conditions where we accidentally miss enabling the
2049 2048 // optimization for one class in the process of being added to the
2050 2049 // dictionary, we must not safepoint after the test of
2051 2050 // BiasedLocking::enabled().
2052 2051 if (UseBiasedLocking && BiasedLocking::enabled()) {
2053 2052 // Set biased locking bit for all loaded classes; it will be
2054 2053 // cleared if revocation occurs too often for this type
2055 2054 // NOTE that we must only do this when the class is initally
2056 2055 // defined, not each time it is referenced from a new class loader
2057 2056 if (k->class_loader() == class_loader()) {
2058 2057 k->set_prototype_header(markOopDesc::biased_locking_prototype());
2059 2058 }
2060 2059 }
2061 2060
2062 2061 // Make a new system dictionary entry.
2063 2062 Klass* sd_check = find_class(d_index, d_hash, name, loader_data);
2064 2063 if (sd_check == NULL) {
2065 2064 dictionary()->add_klass(name, loader_data, k);
2066 2065 notice_modification();
2067 2066 }
2068 2067 #ifdef ASSERT
2069 2068 sd_check = find_class(d_index, d_hash, name, loader_data);
2070 2069 assert (sd_check != NULL, "should have entry in system dictionary");
2071 2070 // Note: there may be a placeholder entry: for circularity testing
2072 2071 // or for parallel defines
2073 2072 #endif
2074 2073 SystemDictionary_lock->notify_all();
2075 2074 }
2076 2075 }
2077 2076
2078 2077
2079 2078 // Try to find a class name using the loader constraints. The
2080 2079 // loader constraints might know about a class that isn't fully loaded
2081 2080 // yet and these will be ignored.
2082 2081 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
2083 2082 Symbol* class_name, Handle class_loader, TRAPS) {
2084 2083
2085 2084 // First see if it has been loaded directly.
2086 2085 // Force the protection domain to be null. (This removes protection checks.)
2087 2086 Handle no_protection_domain;
2088 2087 Klass* klass = find_instance_or_array_klass(class_name, class_loader,
2089 2088 no_protection_domain, CHECK_NULL);
2090 2089 if (klass != NULL)
2091 2090 return klass;
2092 2091
2093 2092 // Now look to see if it has been loaded elsewhere, and is subject to
2094 2093 // a loader constraint that would require this loader to return the
2095 2094 // klass that is already loaded.
2096 2095 if (FieldType::is_array(class_name)) {
2097 2096 // For array classes, their Klass*s are not kept in the
2098 2097 // constraint table. The element Klass*s are.
2099 2098 FieldArrayInfo fd;
2100 2099 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
2101 2100 if (t != T_OBJECT) {
2102 2101 klass = Universe::typeArrayKlassObj(t);
2103 2102 } else {
2104 2103 MutexLocker mu(SystemDictionary_lock, THREAD);
2105 2104 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
2106 2105 }
2107 2106 // If element class already loaded, allocate array klass
2108 2107 if (klass != NULL) {
2109 2108 klass = klass->array_klass_or_null(fd.dimension());
2110 2109 }
2111 2110 } else {
2112 2111 MutexLocker mu(SystemDictionary_lock, THREAD);
2113 2112 // Non-array classes are easy: simply check the constraint table.
2114 2113 klass = constraints()->find_constrained_klass(class_name, class_loader);
2115 2114 }
2116 2115
2117 2116 return klass;
2118 2117 }
2119 2118
2120 2119
2121 2120 bool SystemDictionary::add_loader_constraint(Symbol* class_name,
2122 2121 Handle class_loader1,
2123 2122 Handle class_loader2,
2124 2123 Thread* THREAD) {
2125 2124 ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
2126 2125 ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
2127 2126
2128 2127 Symbol* constraint_name = NULL;
2129 2128 if (!FieldType::is_array(class_name)) {
2130 2129 constraint_name = class_name;
2131 2130 } else {
2132 2131 // For array classes, their Klass*s are not kept in the
2133 2132 // constraint table. The element classes are.
2134 2133 FieldArrayInfo fd;
2135 2134 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
2136 2135 // primitive types always pass
2137 2136 if (t != T_OBJECT) {
2138 2137 return true;
2139 2138 } else {
2140 2139 constraint_name = fd.object_key();
2141 2140 }
2142 2141 }
2143 2142 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
2144 2143 int d_index1 = dictionary()->hash_to_index(d_hash1);
2145 2144
2146 2145 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
2147 2146 int d_index2 = dictionary()->hash_to_index(d_hash2);
2148 2147 {
2149 2148 MutexLocker mu_s(SystemDictionary_lock, THREAD);
2150 2149
2151 2150 // Better never do a GC while we're holding these oops
2152 2151 No_Safepoint_Verifier nosafepoint;
2153 2152
2154 2153 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
2155 2154 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
2156 2155 return constraints()->add_entry(constraint_name, klass1, class_loader1,
2157 2156 klass2, class_loader2);
2158 2157 }
2159 2158 }
2160 2159
2161 2160 // Add entry to resolution error table to record the error when the first
2162 2161 // attempt to resolve a reference to a class has failed.
2163 2162 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, Symbol* error) {
2164 2163 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2165 2164 int index = resolution_errors()->hash_to_index(hash);
2166 2165 {
2167 2166 MutexLocker ml(SystemDictionary_lock, Thread::current());
2168 2167 resolution_errors()->add_entry(index, hash, pool, which, error);
2169 2168 }
2170 2169 }
2171 2170
2172 2171 // Delete a resolution error for RedefineClasses for a constant pool is going away
2173 2172 void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
2174 2173 resolution_errors()->delete_entry(pool);
2175 2174 }
2176 2175
2177 2176 // Lookup resolution error table. Returns error if found, otherwise NULL.
2178 2177 Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) {
2179 2178 unsigned int hash = resolution_errors()->compute_hash(pool, which);
2180 2179 int index = resolution_errors()->hash_to_index(hash);
2181 2180 {
2182 2181 MutexLocker ml(SystemDictionary_lock, Thread::current());
2183 2182 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
2184 2183 return (entry != NULL) ? entry->error() : (Symbol*)NULL;
2185 2184 }
2186 2185 }
2187 2186
2188 2187
2189 2188 // Signature constraints ensure that callers and callees agree about
2190 2189 // the meaning of type names in their signatures. This routine is the
2191 2190 // intake for constraints. It collects them from several places:
2192 2191 //
2193 2192 // * LinkResolver::resolve_method (if check_access is true) requires
2194 2193 // that the resolving class (the caller) and the defining class of
2195 2194 // the resolved method (the callee) agree on each type in the
2196 2195 // method's signature.
2197 2196 //
2198 2197 // * LinkResolver::resolve_interface_method performs exactly the same
2199 2198 // checks.
2200 2199 //
2201 2200 // * LinkResolver::resolve_field requires that the constant pool
2202 2201 // attempting to link to a field agree with the field's defining
2203 2202 // class about the type of the field signature.
2204 2203 //
2205 2204 // * klassVtable::initialize_vtable requires that, when a class
2206 2205 // overrides a vtable entry allocated by a superclass, that the
2207 2206 // overriding method (i.e., the callee) agree with the superclass
2208 2207 // on each type in the method's signature.
2209 2208 //
2210 2209 // * klassItable::initialize_itable requires that, when a class fills
2211 2210 // in its itables, for each non-abstract method installed in an
2212 2211 // itable, the method (i.e., the callee) agree with the interface
2213 2212 // on each type in the method's signature.
2214 2213 //
2215 2214 // All those methods have a boolean (check_access, checkconstraints)
2216 2215 // which turns off the checks. This is used from specialized contexts
2217 2216 // such as bootstrapping, dumping, and debugging.
2218 2217 //
2219 2218 // No direct constraint is placed between the class and its
2220 2219 // supertypes. Constraints are only placed along linked relations
2221 2220 // between callers and callees. When a method overrides or implements
2222 2221 // an abstract method in a supertype (superclass or interface), the
2223 2222 // constraints are placed as if the supertype were the caller to the
2224 2223 // overriding method. (This works well, since callers to the
2225 2224 // supertype have already established agreement between themselves and
2226 2225 // the supertype.) As a result of all this, a class can disagree with
2227 2226 // its supertype about the meaning of a type name, as long as that
2228 2227 // class neither calls a relevant method of the supertype, nor is
2229 2228 // called (perhaps via an override) from the supertype.
2230 2229 //
2231 2230 //
2232 2231 // SystemDictionary::check_signature_loaders(sig, l1, l2)
2233 2232 //
2234 2233 // Make sure all class components (including arrays) in the given
2235 2234 // signature will be resolved to the same class in both loaders.
2236 2235 // Returns the name of the type that failed a loader constraint check, or
2237 2236 // NULL if no constraint failed. No exception except OOME is thrown.
2238 2237 // Arrays are not added to the loader constraint table, their elements are.
2239 2238 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
2240 2239 Handle loader1, Handle loader2,
2241 2240 bool is_method, TRAPS) {
2242 2241 // Nothing to do if loaders are the same.
2243 2242 if (loader1() == loader2()) {
2244 2243 return NULL;
2245 2244 }
2246 2245
2247 2246 SignatureStream sig_strm(signature, is_method);
2248 2247 while (!sig_strm.is_done()) {
2249 2248 if (sig_strm.is_object()) {
2250 2249 Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
2251 2250 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
2252 2251 return sig;
2253 2252 }
2254 2253 }
2255 2254 sig_strm.next();
2256 2255 }
2257 2256 return NULL;
2258 2257 }
2259 2258
2260 2259
2261 2260 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
2262 2261 Symbol* signature,
2263 2262 TRAPS) {
2264 2263 methodHandle empty;
2265 2264 assert(EnableInvokeDynamic, "");
2266 2265 assert(MethodHandles::is_signature_polymorphic(iid) &&
2267 2266 MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
2268 2267 iid != vmIntrinsics::_invokeGeneric,
2269 2268 err_msg("must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid)));
2270 2269
2271 2270 unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
2272 2271 int index = invoke_method_table()->hash_to_index(hash);
2273 2272 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2274 2273 methodHandle m;
2275 2274 if (spe == NULL || spe->method() == NULL) {
2276 2275 spe = NULL;
2277 2276 // Must create lots of stuff here, but outside of the SystemDictionary lock.
2278 2277 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
2279 2278 if (!Arguments::is_interpreter_only()) {
2280 2279 // Generate a compiled form of the MH intrinsic.
2281 2280 AdapterHandlerLibrary::create_native_wrapper(m);
2282 2281 // Check if have the compiled code.
2283 2282 if (!m->has_compiled_code()) {
2284 2283 THROW_MSG_(vmSymbols::java_lang_VirtualMachineError(),
2285 2284 "out of space in CodeCache for method handle intrinsic", empty);
2286 2285 }
2287 2286 }
2288 2287 // Now grab the lock. We might have to throw away the new method,
2289 2288 // if a racing thread has managed to install one at the same time.
2290 2289 {
2291 2290 MutexLocker ml(SystemDictionary_lock, THREAD);
2292 2291 spe = invoke_method_table()->find_entry(index, hash, signature, iid);
2293 2292 if (spe == NULL)
2294 2293 spe = invoke_method_table()->add_entry(index, hash, signature, iid);
2295 2294 if (spe->method() == NULL)
2296 2295 spe->set_method(m());
2297 2296 }
2298 2297 }
2299 2298
2300 2299 assert(spe != NULL && spe->method() != NULL, "");
2301 2300 assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
2302 2301 spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
2303 2302 "MH intrinsic invariant");
2304 2303 return spe->method();
2305 2304 }
2306 2305
2307 2306 // Helper for unpacking the return value from linkMethod and linkCallSite.
2308 2307 static methodHandle unpack_method_and_appendix(Handle mname,
2309 2308 KlassHandle accessing_klass,
2310 2309 objArrayHandle appendix_box,
2311 2310 Handle* appendix_result,
2312 2311 TRAPS) {
2313 2312 methodHandle empty;
2314 2313 if (mname.not_null()) {
2315 2314 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
2316 2315 if (vmtarget != NULL && vmtarget->is_method()) {
2317 2316 Method* m = (Method*)vmtarget;
2318 2317 oop appendix = appendix_box->obj_at(0);
2319 2318 if (TraceMethodHandles) {
2320 2319 #ifndef PRODUCT
2321 2320 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
2322 2321 m->print();
2323 2322 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
2324 2323 tty->cr();
2325 2324 #endif //PRODUCT
2326 2325 }
2327 2326 (*appendix_result) = Handle(THREAD, appendix);
2328 2327 // the target is stored in the cpCache and if a reference to this
2329 2328 // MethodName is dropped we need a way to make sure the
2330 2329 // class_loader containing this method is kept alive.
2331 2330 // FIXME: the appendix might also preserve this dependency.
2332 2331 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data();
2333 2332 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
2334 2333 return methodHandle(THREAD, m);
2335 2334 }
2336 2335 }
2337 2336 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
2338 2337 return empty;
2339 2338 }
2340 2339
2341 2340 methodHandle SystemDictionary::find_method_handle_invoker(Symbol* name,
2342 2341 Symbol* signature,
2343 2342 KlassHandle accessing_klass,
2344 2343 Handle *appendix_result,
2345 2344 Handle *method_type_result,
2346 2345 TRAPS) {
2347 2346 methodHandle empty;
2348 2347 assert(EnableInvokeDynamic, "");
2349 2348 assert(!THREAD->is_Compiler_thread(), "");
2350 2349 Handle method_type =
2351 2350 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
2352 2351 if (false) { // FIXME: Decide if the Java upcall should resolve signatures.
2353 2352 method_type = java_lang_String::create_from_symbol(signature, CHECK_(empty));
2354 2353 }
2355 2354
2356 2355 KlassHandle mh_klass = SystemDictionary::MethodHandle_klass();
2357 2356 int ref_kind = JVM_REF_invokeVirtual;
2358 2357 Handle name_str = StringTable::intern(name, CHECK_(empty));
2359 2358 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2360 2359 assert(appendix_box->obj_at(0) == NULL, "");
2361 2360
2362 2361 // This should not happen. JDK code should take care of that.
2363 2362 if (accessing_klass.is_null() || method_type.is_null()) {
2364 2363 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
2365 2364 }
2366 2365
2367 2366 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
2368 2367 JavaCallArguments args;
2369 2368 args.push_oop(accessing_klass()->java_mirror());
2370 2369 args.push_int(ref_kind);
2371 2370 args.push_oop(mh_klass()->java_mirror());
2372 2371 args.push_oop(name_str());
2373 2372 args.push_oop(method_type());
2374 2373 args.push_oop(appendix_box());
2375 2374 JavaValue result(T_OBJECT);
2376 2375 JavaCalls::call_static(&result,
2377 2376 SystemDictionary::MethodHandleNatives_klass(),
2378 2377 vmSymbols::linkMethod_name(),
2379 2378 vmSymbols::linkMethod_signature(),
2380 2379 &args, CHECK_(empty));
2381 2380 Handle mname(THREAD, (oop) result.get_jobject());
2382 2381 (*method_type_result) = method_type;
2383 2382 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
2384 2383 }
2385 2384
2386 2385
2387 2386 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given
2388 2387 // signature, as interpreted relative to the given class loader.
2389 2388 // Because of class loader constraints, all method handle usage must be
2390 2389 // consistent with this loader.
2391 2390 Handle SystemDictionary::find_method_handle_type(Symbol* signature,
2392 2391 KlassHandle accessing_klass,
2393 2392 TRAPS) {
2394 2393 Handle empty;
2395 2394 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
2396 2395 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
2397 2396 int index = invoke_method_table()->hash_to_index(hash);
2398 2397 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2399 2398 if (spe != NULL && spe->method_type() != NULL) {
2400 2399 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
2401 2400 return Handle(THREAD, spe->method_type());
2402 2401 } else if (THREAD->is_Compiler_thread()) {
2403 2402 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
2404 2403 return Handle(); // do not attempt from within compiler, unless it was cached
2405 2404 }
2406 2405
2407 2406 Handle class_loader, protection_domain;
2408 2407 bool is_on_bcp = true; // keep this true as long as we can materialize from the boot classloader
2409 2408 int npts = ArgumentCount(signature).size();
2410 2409 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty));
2411 2410 int arg = 0;
2412 2411 Handle rt; // the return type from the signature
2413 2412 ResourceMark rm(THREAD);
2414 2413 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
2415 2414 oop mirror = NULL;
2416 2415 if (is_on_bcp) {
2417 2416 // Note: class_loader & protection_domain are both null at this point.
2418 2417 mirror = ss.as_java_mirror(class_loader, protection_domain,
2419 2418 SignatureStream::ReturnNull, CHECK_(empty));
2420 2419 if (mirror == NULL) {
2421 2420 // fall back from BCP to accessing_klass
2422 2421 if (accessing_klass.not_null()) {
2423 2422 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader());
2424 2423 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain());
2425 2424 }
2426 2425 is_on_bcp = false;
2427 2426 }
2428 2427 }
2429 2428 if (!is_on_bcp) {
2430 2429 // Resolve, throwing a real error if it doesn't work.
2431 2430 mirror = ss.as_java_mirror(class_loader, protection_domain,
2432 2431 SignatureStream::NCDFError, CHECK_(empty));
2433 2432 }
2434 2433 if (ss.at_return_type())
2435 2434 rt = Handle(THREAD, mirror);
2436 2435 else
2437 2436 pts->obj_at_put(arg++, mirror);
2438 2437
2439 2438 // Check accessibility.
2440 2439 if (ss.is_object() && accessing_klass.not_null()) {
2441 2440 Klass* sel_klass = java_lang_Class::as_Klass(mirror);
2442 2441 mirror = NULL; // safety
2443 2442 // Emulate ConstantPool::verify_constant_pool_resolve.
2444 2443 if (sel_klass->oop_is_objArray())
2445 2444 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
2446 2445 if (sel_klass->oop_is_instance()) {
2447 2446 KlassHandle sel_kh(THREAD, sel_klass);
2448 2447 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty));
2449 2448 }
2450 2449 }
2451 2450 }
2452 2451 assert(arg == npts, "");
2453 2452
2454 2453 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType
2455 2454 JavaCallArguments args(Handle(THREAD, rt()));
2456 2455 args.push_oop(pts());
2457 2456 JavaValue result(T_OBJECT);
2458 2457 JavaCalls::call_static(&result,
2459 2458 SystemDictionary::MethodHandleNatives_klass(),
2460 2459 vmSymbols::findMethodHandleType_name(),
2461 2460 vmSymbols::findMethodHandleType_signature(),
2462 2461 &args, CHECK_(empty));
2463 2462 Handle method_type(THREAD, (oop) result.get_jobject());
2464 2463
2465 2464 if (is_on_bcp) {
2466 2465 // We can cache this MethodType inside the JVM.
2467 2466 MutexLocker ml(SystemDictionary_lock, THREAD);
2468 2467 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
2469 2468 if (spe == NULL)
2470 2469 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
2471 2470 if (spe->method_type() == NULL) {
2472 2471 spe->set_method_type(method_type());
2473 2472 }
2474 2473 }
2475 2474
2476 2475 // report back to the caller with the MethodType
2477 2476 return method_type;
2478 2477 }
2479 2478
2480 2479 // Ask Java code to find or construct a method handle constant.
2481 2480 Handle SystemDictionary::link_method_handle_constant(KlassHandle caller,
2482 2481 int ref_kind, //e.g., JVM_REF_invokeVirtual
2483 2482 KlassHandle callee,
2484 2483 Symbol* name_sym,
2485 2484 Symbol* signature,
2486 2485 TRAPS) {
2487 2486 Handle empty;
2488 2487 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
2489 2488 Handle type;
2490 2489 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
2491 2490 type = find_method_handle_type(signature, caller, CHECK_(empty));
2492 2491 } else if (caller.is_null()) {
2493 2492 // This should not happen. JDK code should take care of that.
2494 2493 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
2495 2494 } else {
2496 2495 ResourceMark rm(THREAD);
2497 2496 SignatureStream ss(signature, false);
2498 2497 if (!ss.is_done()) {
2499 2498 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(),
2500 2499 SignatureStream::NCDFError, CHECK_(empty));
2501 2500 type = Handle(THREAD, mirror);
2502 2501 ss.next();
2503 2502 if (!ss.is_done()) type = Handle(); // error!
2504 2503 }
2505 2504 }
2506 2505 if (type.is_null()) {
2507 2506 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
2508 2507 }
2509 2508
2510 2509 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
2511 2510 JavaCallArguments args;
2512 2511 args.push_oop(caller->java_mirror()); // the referring class
2513 2512 args.push_int(ref_kind);
2514 2513 args.push_oop(callee->java_mirror()); // the target class
2515 2514 args.push_oop(name());
2516 2515 args.push_oop(type());
2517 2516 JavaValue result(T_OBJECT);
2518 2517 JavaCalls::call_static(&result,
2519 2518 SystemDictionary::MethodHandleNatives_klass(),
2520 2519 vmSymbols::linkMethodHandleConstant_name(),
2521 2520 vmSymbols::linkMethodHandleConstant_signature(),
2522 2521 &args, CHECK_(empty));
2523 2522 return Handle(THREAD, (oop) result.get_jobject());
2524 2523 }
2525 2524
2526 2525 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given
2527 2526 // name and signature, as interpreted relative to the given class loader.
2528 2527 methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller,
2529 2528 Handle bootstrap_specifier,
2530 2529 Symbol* name,
2531 2530 Symbol* type,
2532 2531 Handle *appendix_result,
2533 2532 Handle *method_type_result,
2534 2533 TRAPS) {
2535 2534 methodHandle empty;
2536 2535 Handle bsm, info;
2537 2536 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
2538 2537 bsm = bootstrap_specifier;
2539 2538 } else {
2540 2539 assert(bootstrap_specifier->is_objArray(), "");
2541 2540 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
2542 2541 int len = args->length();
2543 2542 assert(len >= 1, "");
2544 2543 bsm = Handle(THREAD, args->obj_at(0));
2545 2544 if (len > 1) {
2546 2545 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
2547 2546 for (int i = 1; i < len; i++)
2548 2547 args1->obj_at_put(i-1, args->obj_at(i));
2549 2548 info = Handle(THREAD, args1);
2550 2549 }
2551 2550 }
2552 2551 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
2553 2552 "caller must supply a valid BSM");
2554 2553
2555 2554 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
2556 2555 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
2557 2556
2558 2557 // This should not happen. JDK code should take care of that.
2559 2558 if (caller.is_null() || method_type.is_null()) {
2560 2559 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
2561 2560 }
2562 2561
2563 2562 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
2564 2563 assert(appendix_box->obj_at(0) == NULL, "");
2565 2564
2566 2565 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
2567 2566 JavaCallArguments args;
2568 2567 args.push_oop(caller->java_mirror());
2569 2568 args.push_oop(bsm());
2570 2569 args.push_oop(method_name());
2571 2570 args.push_oop(method_type());
2572 2571 args.push_oop(info());
2573 2572 args.push_oop(appendix_box);
2574 2573 JavaValue result(T_OBJECT);
2575 2574 JavaCalls::call_static(&result,
2576 2575 SystemDictionary::MethodHandleNatives_klass(),
2577 2576 vmSymbols::linkCallSite_name(),
2578 2577 vmSymbols::linkCallSite_signature(),
2579 2578 &args, CHECK_(empty));
2580 2579 Handle mname(THREAD, (oop) result.get_jobject());
2581 2580 (*method_type_result) = method_type;
2582 2581 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
2583 2582 }
2584 2583
2585 2584 // Since the identity hash code for symbols changes when the symbols are
2586 2585 // moved from the regular perm gen (hash in the mark word) to the shared
2587 2586 // spaces (hash is the address), the classes loaded into the dictionary
2588 2587 // may be in the wrong buckets.
2589 2588
2590 2589 void SystemDictionary::reorder_dictionary() {
2591 2590 dictionary()->reorder_dictionary();
2592 2591 }
2593 2592
2594 2593
2595 2594 void SystemDictionary::copy_buckets(char** top, char* end) {
2596 2595 dictionary()->copy_buckets(top, end);
2597 2596 }
2598 2597
2599 2598
2600 2599 void SystemDictionary::copy_table(char** top, char* end) {
2601 2600 dictionary()->copy_table(top, end);
2602 2601 }
2603 2602
2604 2603
2605 2604 void SystemDictionary::reverse() {
2606 2605 dictionary()->reverse();
2607 2606 }
2608 2607
2609 2608 int SystemDictionary::number_of_classes() {
2610 2609 return dictionary()->number_of_entries();
2611 2610 }
2612 2611
2613 2612
2614 2613 // ----------------------------------------------------------------------------
2615 2614 void SystemDictionary::print_shared(bool details) {
2616 2615 shared_dictionary()->print(details);
2617 2616 }
2618 2617
2619 2618 void SystemDictionary::print(bool details) {
2620 2619 dictionary()->print(details);
2621 2620
2622 2621 // Placeholders
2623 2622 GCMutexLocker mu(SystemDictionary_lock);
2624 2623 placeholders()->print();
2625 2624
2626 2625 // loader constraints - print under SD_lock
2627 2626 constraints()->print();
2628 2627 }
2629 2628
2630 2629
2631 2630 void SystemDictionary::verify() {
2632 2631 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
2633 2632 guarantee(constraints() != NULL,
2634 2633 "Verify of loader constraints failed");
2635 2634 guarantee(dictionary()->number_of_entries() >= 0 &&
2636 2635 placeholders()->number_of_entries() >= 0,
2637 2636 "Verify of system dictionary failed");
2638 2637
2639 2638 // Verify dictionary
2640 2639 dictionary()->verify();
2641 2640
2642 2641 GCMutexLocker mu(SystemDictionary_lock);
2643 2642 placeholders()->verify();
2644 2643
2645 2644 // Verify constraint table
2646 2645 guarantee(constraints() != NULL, "Verify of loader constraints failed");
2647 2646 constraints()->verify(dictionary(), placeholders());
2648 2647 }
2649 2648
2650 2649 // utility function for class load event
2651 2650 void SystemDictionary::post_class_load_event(const Ticks& start_time,
2652 2651 instanceKlassHandle k,
2653 2652 Handle initiating_loader) {
2654 2653 #if INCLUDE_TRACE
2655 2654 EventClassLoad event(UNTIMED);
2656 2655 if (event.should_commit()) {
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2657 2656 event.set_starttime(start_time);
2658 2657 event.set_loadedClass(k());
2659 2658 oop defining_class_loader = k->class_loader();
2660 2659 event.set_definingClassLoader(defining_class_loader != NULL ?
2661 2660 defining_class_loader->klass() : (Klass*)NULL);
2662 2661 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader();
2663 2662 event.set_initiatingClassLoader(class_loader != NULL ?
2664 2663 class_loader->klass() : (Klass*)NULL);
2665 2664 event.commit();
2666 2665 }
2667 -#endif /* INCLUDE_TRACE */
2666 +#endif // INCLUDE_TRACE
2668 2667 }
2669 2668
2670 2669 #ifndef PRODUCT
2671 2670
2672 2671 // statistics code
2673 2672 class ClassStatistics: AllStatic {
2674 2673 private:
2675 2674 static int nclasses; // number of classes
2676 2675 static int nmethods; // number of methods
2677 2676 static int nmethoddata; // number of methodData
2678 2677 static int class_size; // size of class objects in words
2679 2678 static int method_size; // size of method objects in words
2680 2679 static int debug_size; // size of debug info in methods
2681 2680 static int methoddata_size; // size of methodData objects in words
2682 2681
2683 2682 static void do_class(Klass* k) {
2684 2683 nclasses++;
2685 2684 class_size += k->size();
2686 2685 if (k->oop_is_instance()) {
2687 2686 InstanceKlass* ik = (InstanceKlass*)k;
2688 2687 class_size += ik->methods()->size();
2689 2688 class_size += ik->constants()->size();
2690 2689 class_size += ik->local_interfaces()->size();
2691 2690 class_size += ik->transitive_interfaces()->size();
2692 2691 // We do not have to count implementors, since we only store one!
2693 2692 // SSS: How should these be accounted now that they have moved?
2694 2693 // class_size += ik->fields()->length();
2695 2694 }
2696 2695 }
2697 2696
2698 2697 static void do_method(Method* m) {
2699 2698 nmethods++;
2700 2699 method_size += m->size();
2701 2700 // class loader uses same objArray for empty vectors, so don't count these
2702 2701 if (m->has_stackmap_table()) {
2703 2702 method_size += m->stackmap_data()->size();
2704 2703 }
2705 2704
2706 2705 MethodData* mdo = m->method_data();
2707 2706 if (mdo != NULL) {
2708 2707 nmethoddata++;
2709 2708 methoddata_size += mdo->size();
2710 2709 }
2711 2710 }
2712 2711
2713 2712 public:
2714 2713 static void print() {
2715 2714 SystemDictionary::classes_do(do_class);
2716 2715 SystemDictionary::methods_do(do_method);
2717 2716 tty->print_cr("Class statistics:");
2718 2717 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize);
2719 2718 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods,
2720 2719 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize);
2721 2720 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize);
2722 2721 }
2723 2722 };
2724 2723
2725 2724
2726 2725 int ClassStatistics::nclasses = 0;
2727 2726 int ClassStatistics::nmethods = 0;
2728 2727 int ClassStatistics::nmethoddata = 0;
2729 2728 int ClassStatistics::class_size = 0;
2730 2729 int ClassStatistics::method_size = 0;
2731 2730 int ClassStatistics::debug_size = 0;
2732 2731 int ClassStatistics::methoddata_size = 0;
2733 2732
2734 2733 void SystemDictionary::print_class_statistics() {
2735 2734 ResourceMark rm;
2736 2735 ClassStatistics::print();
2737 2736 }
2738 2737
2739 2738
2740 2739 class MethodStatistics: AllStatic {
2741 2740 public:
2742 2741 enum {
2743 2742 max_parameter_size = 10
2744 2743 };
2745 2744 private:
2746 2745
2747 2746 static int _number_of_methods;
2748 2747 static int _number_of_final_methods;
2749 2748 static int _number_of_static_methods;
2750 2749 static int _number_of_native_methods;
2751 2750 static int _number_of_synchronized_methods;
2752 2751 static int _number_of_profiled_methods;
2753 2752 static int _number_of_bytecodes;
2754 2753 static int _parameter_size_profile[max_parameter_size];
2755 2754 static int _bytecodes_profile[Bytecodes::number_of_java_codes];
2756 2755
2757 2756 static void initialize() {
2758 2757 _number_of_methods = 0;
2759 2758 _number_of_final_methods = 0;
2760 2759 _number_of_static_methods = 0;
2761 2760 _number_of_native_methods = 0;
2762 2761 _number_of_synchronized_methods = 0;
2763 2762 _number_of_profiled_methods = 0;
2764 2763 _number_of_bytecodes = 0;
2765 2764 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0;
2766 2765 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0;
2767 2766 };
2768 2767
2769 2768 static void do_method(Method* m) {
2770 2769 _number_of_methods++;
2771 2770 // collect flag info
2772 2771 if (m->is_final() ) _number_of_final_methods++;
2773 2772 if (m->is_static() ) _number_of_static_methods++;
2774 2773 if (m->is_native() ) _number_of_native_methods++;
2775 2774 if (m->is_synchronized()) _number_of_synchronized_methods++;
2776 2775 if (m->method_data() != NULL) _number_of_profiled_methods++;
2777 2776 // collect parameter size info (add one for receiver, if any)
2778 2777 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++;
2779 2778 // collect bytecodes info
2780 2779 {
2781 2780 Thread *thread = Thread::current();
2782 2781 HandleMark hm(thread);
2783 2782 BytecodeStream s(methodHandle(thread, m));
2784 2783 Bytecodes::Code c;
2785 2784 while ((c = s.next()) >= 0) {
2786 2785 _number_of_bytecodes++;
2787 2786 _bytecodes_profile[c]++;
2788 2787 }
2789 2788 }
2790 2789 }
2791 2790
2792 2791 public:
2793 2792 static void print() {
2794 2793 initialize();
2795 2794 SystemDictionary::methods_do(do_method);
2796 2795 // generate output
2797 2796 tty->cr();
2798 2797 tty->print_cr("Method statistics (static):");
2799 2798 // flag distribution
2800 2799 tty->cr();
2801 2800 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods);
2802 2801 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods);
2803 2802 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods);
2804 2803 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods);
2805 2804 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods);
2806 2805 // parameter size profile
2807 2806 tty->cr();
2808 2807 { int tot = 0;
2809 2808 int avg = 0;
2810 2809 for (int i = 0; i < max_parameter_size; i++) {
2811 2810 int n = _parameter_size_profile[i];
2812 2811 tot += n;
2813 2812 avg += n*i;
2814 2813 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods);
2815 2814 }
2816 2815 assert(tot == _number_of_methods, "should be the same");
2817 2816 tty->print_cr(" %6d methods 100.0%%", _number_of_methods);
2818 2817 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods);
2819 2818 }
2820 2819 // bytecodes profile
2821 2820 tty->cr();
2822 2821 { int tot = 0;
2823 2822 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) {
2824 2823 if (Bytecodes::is_defined(i)) {
2825 2824 Bytecodes::Code c = Bytecodes::cast(i);
2826 2825 int n = _bytecodes_profile[c];
2827 2826 tot += n;
2828 2827 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c));
2829 2828 }
2830 2829 }
2831 2830 assert(tot == _number_of_bytecodes, "should be the same");
2832 2831 tty->print_cr("%9d 100.000%%", _number_of_bytecodes);
2833 2832 }
2834 2833 tty->cr();
2835 2834 }
2836 2835 };
2837 2836
2838 2837 int MethodStatistics::_number_of_methods;
2839 2838 int MethodStatistics::_number_of_final_methods;
2840 2839 int MethodStatistics::_number_of_static_methods;
2841 2840 int MethodStatistics::_number_of_native_methods;
2842 2841 int MethodStatistics::_number_of_synchronized_methods;
2843 2842 int MethodStatistics::_number_of_profiled_methods;
2844 2843 int MethodStatistics::_number_of_bytecodes;
2845 2844 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size];
2846 2845 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes];
2847 2846
2848 2847
2849 2848 void SystemDictionary::print_method_statistics() {
2850 2849 MethodStatistics::print();
2851 2850 }
2852 2851
2853 2852 #endif // PRODUCT
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