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