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