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/stringTable.hpp" 33 #include "classfile/systemDictionary.hpp" 34 #if INCLUDE_CDS 35 #include "classfile/sharedClassUtil.hpp" 36 #include "classfile/systemDictionaryShared.hpp" 37 #endif 38 #include "classfile/vmSymbols.hpp" 39 #include "compiler/compileBroker.hpp" 40 #include "interpreter/bytecodeStream.hpp" 41 #include "interpreter/interpreter.hpp" 42 #include "memory/filemap.hpp" 43 #include "memory/gcLocker.hpp" 44 #include "memory/oopFactory.hpp" 45 #include "oops/instanceKlass.hpp" 46 #include "oops/instanceRefKlass.hpp" 47 #include "oops/klass.inline.hpp" 48 #include "oops/methodData.hpp" 49 #include "oops/objArrayKlass.hpp" 50 #include "oops/oop.inline.hpp" 51 #include "oops/oop.inline2.hpp" 52 #include "oops/typeArrayKlass.hpp" 53 #include "prims/jvmtiEnvBase.hpp" 54 #include "prims/methodHandles.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, throw_error, k_h, THREAD); 185 } 186 return klass; 187 } 188 189 Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, 190 bool throw_error, 191 KlassHandle klass_h, TRAPS) { 192 if (HAS_PENDING_EXCEPTION) { 193 // If we have a pending exception we forward it to the caller, unless throw_error is true, 194 // in which case we have to check whether the pending exception is a ClassNotFoundException, 195 // and if so convert it to a NoClassDefFoundError 196 // And chain the original ClassNotFoundException 197 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) { 198 ResourceMark rm(THREAD); 199 assert(klass_h() == NULL, "Should not have result with exception pending"); 200 Handle e(THREAD, PENDING_EXCEPTION); 201 CLEAR_PENDING_EXCEPTION; 202 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e); 203 } else { 204 return NULL; 205 } 206 } 207 // Class not found, throw appropriate error or exception depending on value of throw_error 208 if (klass_h() == NULL) { 209 ResourceMark rm(THREAD); 210 if (throw_error) { 211 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string()); 212 } else { 213 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string()); 214 } 215 } 216 return (Klass*)klass_h(); 217 } 218 219 220 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, 221 bool throw_error, TRAPS) 222 { 223 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD); 224 } 225 226 227 // Forwards to resolve_instance_class_or_null 228 229 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) { 230 assert(!THREAD->is_Compiler_thread(), 231 err_msg("can not load classes with compiler thread: class=%s, classloader=%s", 232 class_name->as_C_string(), 233 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string())); 234 if (FieldType::is_array(class_name)) { 235 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL); 236 } else if (FieldType::is_obj(class_name)) { 237 ResourceMark rm(THREAD); 238 // Ignore wrapping L and ;. 239 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1, 240 class_name->utf8_length() - 2, CHECK_NULL); 241 return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL); 242 } else { 243 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL); 244 } 245 } 246 247 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) { 248 return resolve_or_null(class_name, Handle(), Handle(), THREAD); 249 } 250 251 // Forwards to resolve_instance_class_or_null 252 253 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name, 254 Handle class_loader, 255 Handle protection_domain, 256 TRAPS) { 257 assert(FieldType::is_array(class_name), "must be array"); 258 Klass* k = NULL; 259 FieldArrayInfo fd; 260 // dimension and object_key in FieldArrayInfo are assigned as a side-effect 261 // of this call 262 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL); 263 if (t == T_OBJECT) { 264 // naked oop "k" is OK here -- we assign back into it 265 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(), 266 class_loader, 267 protection_domain, 268 CHECK_NULL); 269 if (k != NULL) { 270 k = k->array_klass(fd.dimension(), CHECK_NULL); 271 } 272 } else { 273 k = Universe::typeArrayKlassObj(t); 274 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL); 275 } 276 return k; 277 } 278 279 280 // Must be called for any super-class or super-interface resolution 281 // during class definition to allow class circularity checking 282 // super-interface callers: 283 // parse_interfaces - for defineClass & jvmtiRedefineClasses 284 // super-class callers: 285 // ClassFileParser - for defineClass & jvmtiRedefineClasses 286 // load_shared_class - while loading a class from shared archive 287 // resolve_instance_class_or_null: 288 // via: handle_parallel_super_load 289 // when resolving a class that has an existing placeholder with 290 // a saved superclass [i.e. a defineClass is currently in progress] 291 // if another thread is trying to resolve the class, it must do 292 // super-class checks on its own thread to catch class circularity 293 // This last call is critical in class circularity checking for cases 294 // where classloading is delegated to different threads and the 295 // classloader lock is released. 296 // Take the case: Base->Super->Base 297 // 1. If thread T1 tries to do a defineClass of class Base 298 // resolve_super_or_fail creates placeholder: T1, Base (super Super) 299 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super 300 // so it tries to load Super 301 // 3. If we load the class internally, or user classloader uses same thread 302 // loadClassFromxxx or defineClass via parseClassFile Super ... 303 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base) 304 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base 305 // 3.4 calls resolve_super_or_fail Base 306 // 3.5 finds T1,Base -> throws class circularity 307 //OR 4. If T2 tries to resolve Super via defineClass Super ... 308 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base) 309 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super) 310 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2 311 // 4.4 finds T2, Super -> throws class circularity 312 // Must be called, even if superclass is null, since this is 313 // where the placeholder entry is created which claims this 314 // thread is loading this class/classloader. 315 Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name, 316 Symbol* class_name, 317 Handle class_loader, 318 Handle protection_domain, 319 bool is_superclass, 320 TRAPS) { 321 // Double-check, if child class is already loaded, just return super-class,interface 322 // Don't add a placedholder if already loaded, i.e. already in system dictionary 323 // Make sure there's a placeholder for the *child* before resolving. 324 // Used as a claim that this thread is currently loading superclass/classloader 325 // Used here for ClassCircularity checks and also for heap verification 326 // (every InstanceKlass in the heap needs to be in the system dictionary 327 // or have a placeholder). 328 // Must check ClassCircularity before checking if super class is already loaded 329 // 330 // We might not already have a placeholder if this child_name was 331 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass); 332 // the name of the class might not be known until the stream is actually 333 // parsed. 334 // Bugs 4643874, 4715493 335 // compute_hash can have a safepoint 336 337 ClassLoaderData* loader_data = class_loader_data(class_loader); 338 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data); 339 int d_index = dictionary()->hash_to_index(d_hash); 340 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data); 341 int p_index = placeholders()->hash_to_index(p_hash); 342 // can't throw error holding a lock 343 bool child_already_loaded = false; 344 bool throw_circularity_error = false; 345 { 346 MutexLocker mu(SystemDictionary_lock, THREAD); 347 Klass* childk = find_class(d_index, d_hash, child_name, loader_data); 348 Klass* quicksuperk; 349 // to support // loading: if child done loading, just return superclass 350 // if class_name, & class_loader don't match: 351 // if initial define, SD update will give LinkageError 352 // if redefine: compare_class_versions will give HIERARCHY_CHANGED 353 // so we don't throw an exception here. 354 // see: nsk redefclass014 & java.lang.instrument Instrument032 355 if ((childk != NULL ) && (is_superclass) && 356 ((quicksuperk = InstanceKlass::cast(childk)->super()) != NULL) && 357 358 ((quicksuperk->name() == class_name) && 359 (quicksuperk->class_loader() == class_loader()))) { 360 return quicksuperk; 361 } else { 362 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data); 363 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) { 364 throw_circularity_error = true; 365 } 366 } 367 if (!throw_circularity_error) { 368 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD); 369 } 370 } 371 if (throw_circularity_error) { 372 ResourceMark rm(THREAD); 373 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string()); 374 } 375 376 // java.lang.Object should have been found above 377 assert(class_name != NULL, "null super class for resolving"); 378 // Resolve the super class or interface, check results on return 379 Klass* superk = SystemDictionary::resolve_or_null(class_name, 380 class_loader, 381 protection_domain, 382 THREAD); 383 384 KlassHandle superk_h(THREAD, superk); 385 386 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up 387 // It is no longer necessary to keep the placeholder table alive until update_dictionary 388 // or error. GC used to walk the placeholder table as strong roots. 389 // The instanceKlass is kept alive because the class loader is on the stack, 390 // which keeps the loader_data alive, as well as all instanceKlasses in 391 // the loader_data. parseClassFile adds the instanceKlass to loader_data. 392 { 393 MutexLocker mu(SystemDictionary_lock, THREAD); 394 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD); 395 SystemDictionary_lock->notify_all(); 396 } 397 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) { 398 // can null superk 399 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, true, superk_h, THREAD)); 400 } 401 402 return superk_h(); 403 } 404 405 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass, 406 Handle class_loader, 407 Handle protection_domain, 408 TRAPS) { 409 if(!has_checkPackageAccess()) return; 410 411 // Now we have to call back to java to check if the initating class has access 412 JavaValue result(T_VOID); 413 if (TraceProtectionDomainVerification) { 414 // Print out trace information 415 tty->print_cr("Checking package access"); 416 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr(); 417 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr(); 418 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr(); 419 } 420 421 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass()); 422 JavaCalls::call_special(&result, 423 class_loader, 424 system_loader, 425 vmSymbols::checkPackageAccess_name(), 426 vmSymbols::class_protectiondomain_signature(), 427 Handle(THREAD, klass->java_mirror()), 428 protection_domain, 429 THREAD); 430 431 if (TraceProtectionDomainVerification) { 432 if (HAS_PENDING_EXCEPTION) { 433 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!"); 434 } else { 435 tty->print_cr(" -> granted"); 436 } 437 tty->cr(); 438 } 439 440 if (HAS_PENDING_EXCEPTION) return; 441 442 // If no exception has been thrown, we have validated the protection domain 443 // Insert the protection domain of the initiating class into the set. 444 { 445 // We recalculate the entry here -- we've called out to java since 446 // the last time it was calculated. 447 ClassLoaderData* loader_data = class_loader_data(class_loader); 448 449 Symbol* kn = klass->name(); 450 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data); 451 int d_index = dictionary()->hash_to_index(d_hash); 452 453 MutexLocker mu(SystemDictionary_lock, THREAD); 454 { 455 // Note that we have an entry, and entries can be deleted only during GC, 456 // so we cannot allow GC to occur while we're holding this entry. 457 458 // We're using a No_Safepoint_Verifier to catch any place where we 459 // might potentially do a GC at all. 460 // Dictionary::do_unloading() asserts that classes in SD are only 461 // unloaded at a safepoint. Anonymous classes are not in SD. 462 No_Safepoint_Verifier nosafepoint; 463 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data, 464 protection_domain, THREAD); 465 } 466 } 467 } 468 469 // We only get here if this thread finds that another thread 470 // has already claimed the placeholder token for the current operation, 471 // but that other thread either never owned or gave up the 472 // object lock 473 // Waits on SystemDictionary_lock to indicate placeholder table updated 474 // On return, caller must recheck placeholder table state 475 // 476 // We only get here if 477 // 1) custom classLoader, i.e. not bootstrap classloader 478 // 2) UnsyncloadClass not set 479 // 3) custom classLoader has broken the class loader objectLock 480 // so another thread got here in parallel 481 // 482 // lockObject must be held. 483 // Complicated dance due to lock ordering: 484 // Must first release the classloader object lock to 485 // allow initial definer to complete the class definition 486 // and to avoid deadlock 487 // Reclaim classloader lock object with same original recursion count 488 // Must release SystemDictionary_lock after notify, since 489 // class loader lock must be claimed before SystemDictionary_lock 490 // to prevent deadlocks 491 // 492 // The notify allows applications that did an untimed wait() on 493 // the classloader object lock to not hang. 494 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) { 495 assert_lock_strong(SystemDictionary_lock); 496 497 bool calledholdinglock 498 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject); 499 assert(calledholdinglock,"must hold lock for notify"); 500 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait"); 501 ObjectSynchronizer::notifyall(lockObject, THREAD); 502 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD); 503 SystemDictionary_lock->wait(); 504 SystemDictionary_lock->unlock(); 505 ObjectSynchronizer::reenter(lockObject, recursions, THREAD); 506 SystemDictionary_lock->lock(); 507 } 508 509 // If the class in is in the placeholder table, class loading is in progress 510 // For cases where the application changes threads to load classes, it 511 // is critical to ClassCircularity detection that we try loading 512 // the superclass on the same thread internally, so we do parallel 513 // super class loading here. 514 // This also is critical in cases where the original thread gets stalled 515 // even in non-circularity situations. 516 // Note: must call resolve_super_or_fail even if null super - 517 // to force placeholder entry creation for this class for circularity detection 518 // Caller must check for pending exception 519 // Returns non-null Klass* if other thread has completed load 520 // and we are done, 521 // If return null Klass* and no pending exception, the caller must load the class 522 instanceKlassHandle SystemDictionary::handle_parallel_super_load( 523 Symbol* name, Symbol* superclassname, Handle class_loader, 524 Handle protection_domain, Handle lockObject, TRAPS) { 525 526 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 527 ClassLoaderData* loader_data = class_loader_data(class_loader); 528 unsigned int d_hash = dictionary()->compute_hash(name, loader_data); 529 int d_index = dictionary()->hash_to_index(d_hash); 530 unsigned int p_hash = placeholders()->compute_hash(name, loader_data); 531 int p_index = placeholders()->hash_to_index(p_hash); 532 533 // superk is not used, resolve_super called for circularity check only 534 // This code is reached in two situations. One if this thread 535 // is loading the same class twice (e.g. ClassCircularity, or 536 // java.lang.instrument). 537 // The second is if another thread started the resolve_super first 538 // and has not yet finished. 539 // In both cases the original caller will clean up the placeholder 540 // entry on error. 541 Klass* superk = SystemDictionary::resolve_super_or_fail(name, 542 superclassname, 543 class_loader, 544 protection_domain, 545 true, 546 CHECK_(nh)); 547 548 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete 549 // Serial class loaders and bootstrap classloader do wait for superclass loads 550 if (!class_loader.is_null() && is_parallelCapable(class_loader)) { 551 MutexLocker mu(SystemDictionary_lock, THREAD); 552 // Check if classloading completed while we were loading superclass or waiting 553 Klass* check = find_class(d_index, d_hash, name, loader_data); 554 if (check != NULL) { 555 // Klass is already loaded, so just return it 556 return(instanceKlassHandle(THREAD, check)); 557 } else { 558 return nh; 559 } 560 } 561 562 // must loop to both handle other placeholder updates 563 // and spurious notifications 564 bool super_load_in_progress = true; 565 PlaceholderEntry* placeholder; 566 while (super_load_in_progress) { 567 MutexLocker mu(SystemDictionary_lock, THREAD); 568 // Check if classloading completed while we were loading superclass or waiting 569 Klass* check = find_class(d_index, d_hash, name, loader_data); 570 if (check != NULL) { 571 // Klass is already loaded, so just return it 572 return(instanceKlassHandle(THREAD, check)); 573 } else { 574 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data); 575 if (placeholder && placeholder->super_load_in_progress() ){ 576 // Before UnsyncloadClass: 577 // We only get here if the application has released the 578 // classloader lock when another thread was in the middle of loading a 579 // superclass/superinterface for this class, and now 580 // this thread is also trying to load this class. 581 // To minimize surprises, the first thread that started to 582 // load a class should be the one to complete the loading 583 // with the classfile it initially expected. 584 // This logic has the current thread wait once it has done 585 // all the superclass/superinterface loading it can, until 586 // the original thread completes the class loading or fails 587 // If it completes we will use the resulting InstanceKlass 588 // which we will find below in the systemDictionary. 589 // We also get here for parallel bootstrap classloader 590 if (class_loader.is_null()) { 591 SystemDictionary_lock->wait(); 592 } else { 593 double_lock_wait(lockObject, THREAD); 594 } 595 } else { 596 // If not in SD and not in PH, other thread's load must have failed 597 super_load_in_progress = false; 598 } 599 } 600 } 601 return (nh); 602 } 603 604 605 Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name, 606 Handle class_loader, 607 Handle protection_domain, 608 TRAPS) { 609 assert(name != NULL && !FieldType::is_array(name) && 610 !FieldType::is_obj(name), "invalid class name"); 611 612 Ticks class_load_start_time = Ticks::now(); 613 614 // Fix for 4474172; see evaluation for more details 615 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader())); 616 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL); 617 618 // Do lookup to see if class already exist and the protection domain 619 // has the right access 620 // This call uses find which checks protection domain already matches 621 // All subsequent calls use find_class, and set has_loaded_class so that 622 // before we return a result we call out to java to check for valid protection domain 623 // to allow returning the Klass* and add it to the pd_set if it is valid 624 unsigned int d_hash = dictionary()->compute_hash(name, loader_data); 625 int d_index = dictionary()->hash_to_index(d_hash); 626 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data, 627 protection_domain, THREAD); 628 if (probe != NULL) return probe; 629 630 631 // Non-bootstrap class loaders will call out to class loader and 632 // define via jvm/jni_DefineClass which will acquire the 633 // class loader object lock to protect against multiple threads 634 // defining the class in parallel by accident. 635 // This lock must be acquired here so the waiter will find 636 // any successful result in the SystemDictionary and not attempt 637 // the define 638 // ParallelCapable Classloaders and the bootstrap classloader, 639 // or all classloaders with UnsyncloadClass do not acquire lock here 640 bool DoObjectLock = true; 641 if (is_parallelCapable(class_loader)) { 642 DoObjectLock = false; 643 } 644 645 unsigned int p_hash = placeholders()->compute_hash(name, loader_data); 646 int p_index = placeholders()->hash_to_index(p_hash); 647 648 // Class is not in SystemDictionary so we have to do loading. 649 // Make sure we are synchronized on the class loader before we proceed 650 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 651 check_loader_lock_contention(lockObject, THREAD); 652 ObjectLocker ol(lockObject, THREAD, DoObjectLock); 653 654 // Check again (after locking) if class already exist in SystemDictionary 655 bool class_has_been_loaded = false; 656 bool super_load_in_progress = false; 657 bool havesupername = false; 658 instanceKlassHandle k; 659 PlaceholderEntry* placeholder; 660 Symbol* superclassname = NULL; 661 662 { 663 MutexLocker mu(SystemDictionary_lock, THREAD); 664 Klass* check = find_class(d_index, d_hash, name, loader_data); 665 if (check != NULL) { 666 // Klass is already loaded, so just return it 667 class_has_been_loaded = true; 668 k = instanceKlassHandle(THREAD, check); 669 } else { 670 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data); 671 if (placeholder && placeholder->super_load_in_progress()) { 672 super_load_in_progress = true; 673 if (placeholder->havesupername() == true) { 674 superclassname = placeholder->supername(); 675 havesupername = true; 676 } 677 } 678 } 679 } 680 681 // If the class is in the placeholder table, class loading is in progress 682 if (super_load_in_progress && havesupername==true) { 683 k = SystemDictionary::handle_parallel_super_load(name, superclassname, 684 class_loader, protection_domain, lockObject, THREAD); 685 if (HAS_PENDING_EXCEPTION) { 686 return NULL; 687 } 688 if (!k.is_null()) { 689 class_has_been_loaded = true; 690 } 691 } 692 693 bool throw_circularity_error = false; 694 if (!class_has_been_loaded) { 695 bool load_instance_added = false; 696 697 // add placeholder entry to record loading instance class 698 // Five cases: 699 // All cases need to prevent modifying bootclasssearchpath 700 // in parallel with a classload of same classname 701 // Redefineclasses uses existence of the placeholder for the duration 702 // of the class load to prevent concurrent redefinition of not completely 703 // defined classes. 704 // case 1. traditional classloaders that rely on the classloader object lock 705 // - no other need for LOAD_INSTANCE 706 // case 2. traditional classloaders that break the classloader object lock 707 // as a deadlock workaround. Detection of this case requires that 708 // this check is done while holding the classloader object lock, 709 // and that lock is still held when calling classloader's loadClass. 710 // For these classloaders, we ensure that the first requestor 711 // completes the load and other requestors wait for completion. 712 // case 3. UnsyncloadClass - don't use objectLocker 713 // With this flag, we allow parallel classloading of a 714 // class/classloader pair 715 // case4. Bootstrap classloader - don't own objectLocker 716 // This classloader supports parallelism at the classloader level, 717 // but only allows a single load of a class/classloader pair. 718 // No performance benefit and no deadlock issues. 719 // case 5. parallelCapable user level classloaders - without objectLocker 720 // Allow parallel classloading of a class/classloader pair 721 722 { 723 MutexLocker mu(SystemDictionary_lock, THREAD); 724 if (class_loader.is_null() || !is_parallelCapable(class_loader)) { 725 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data); 726 if (oldprobe) { 727 // only need check_seen_thread once, not on each loop 728 // 6341374 java/lang/Instrument with -Xcomp 729 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) { 730 throw_circularity_error = true; 731 } else { 732 // case 1: traditional: should never see load_in_progress. 733 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) { 734 735 // case 4: bootstrap classloader: prevent futile classloading, 736 // wait on first requestor 737 if (class_loader.is_null()) { 738 SystemDictionary_lock->wait(); 739 } else { 740 // case 2: traditional with broken classloader lock. wait on first 741 // requestor. 742 double_lock_wait(lockObject, THREAD); 743 } 744 // Check if classloading completed while we were waiting 745 Klass* check = find_class(d_index, d_hash, name, loader_data); 746 if (check != NULL) { 747 // Klass is already loaded, so just return it 748 k = instanceKlassHandle(THREAD, check); 749 class_has_been_loaded = true; 750 } 751 // check if other thread failed to load and cleaned up 752 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data); 753 } 754 } 755 } 756 } 757 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock 758 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try 759 // LOAD_INSTANCE in parallel 760 761 if (!throw_circularity_error && !class_has_been_loaded) { 762 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD); 763 load_instance_added = true; 764 // For class loaders that do not acquire the classloader object lock, 765 // if they did not catch another thread holding LOAD_INSTANCE, 766 // need a check analogous to the acquire ObjectLocker/find_class 767 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL 768 // one final check if the load has already completed 769 // class loaders holding the ObjectLock shouldn't find the class here 770 Klass* check = find_class(d_index, d_hash, name, loader_data); 771 if (check != NULL) { 772 // Klass is already loaded, so return it after checking/adding protection domain 773 k = instanceKlassHandle(THREAD, check); 774 class_has_been_loaded = true; 775 } 776 } 777 } 778 779 // must throw error outside of owning lock 780 if (throw_circularity_error) { 781 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup"); 782 ResourceMark rm(THREAD); 783 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string()); 784 } 785 786 if (!class_has_been_loaded) { 787 788 // Do actual loading 789 k = load_instance_class(name, class_loader, THREAD); 790 791 // For UnsyncloadClass only 792 // If they got a linkageError, check if a parallel class load succeeded. 793 // If it did, then for bytecode resolution the specification requires 794 // that we return the same result we did for the other thread, i.e. the 795 // successfully loaded InstanceKlass 796 // Should not get here for classloaders that support parallelism 797 // with the new cleaner mechanism, even with AllowParallelDefineClass 798 // Bootstrap goes through here to allow for an extra guarantee check 799 if (UnsyncloadClass || (class_loader.is_null())) { 800 if (k.is_null() && HAS_PENDING_EXCEPTION 801 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) { 802 MutexLocker mu(SystemDictionary_lock, THREAD); 803 Klass* check = find_class(d_index, d_hash, name, loader_data); 804 if (check != NULL) { 805 // Klass is already loaded, so just use it 806 k = instanceKlassHandle(THREAD, check); 807 CLEAR_PENDING_EXCEPTION; 808 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?"); 809 } 810 } 811 } 812 813 // If everything was OK (no exceptions, no null return value), and 814 // class_loader is NOT the defining loader, do a little more bookkeeping. 815 if (!HAS_PENDING_EXCEPTION && !k.is_null() && 816 k->class_loader() != class_loader()) { 817 818 check_constraints(d_index, d_hash, k, class_loader, false, THREAD); 819 820 // Need to check for a PENDING_EXCEPTION again; check_constraints 821 // can throw and doesn't use the CHECK macro. 822 if (!HAS_PENDING_EXCEPTION) { 823 { // Grabbing the Compile_lock prevents systemDictionary updates 824 // during compilations. 825 MutexLocker mu(Compile_lock, THREAD); 826 update_dictionary(d_index, d_hash, p_index, p_hash, 827 k, class_loader, THREAD); 828 } 829 830 if (JvmtiExport::should_post_class_load()) { 831 Thread *thread = THREAD; 832 assert(thread->is_Java_thread(), "thread->is_Java_thread()"); 833 JvmtiExport::post_class_load((JavaThread *) thread, k()); 834 } 835 } 836 } 837 } // load_instance_class loop 838 839 if (load_instance_added == true) { 840 // clean up placeholder entries for LOAD_INSTANCE success or error 841 // This brackets the SystemDictionary updates for both defining 842 // and initiating loaders 843 MutexLocker mu(SystemDictionary_lock, THREAD); 844 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD); 845 SystemDictionary_lock->notify_all(); 846 } 847 } 848 849 if (HAS_PENDING_EXCEPTION || k.is_null()) { 850 return NULL; 851 } 852 853 post_class_load_event(class_load_start_time, k, class_loader); 854 855 #ifdef ASSERT 856 { 857 ClassLoaderData* loader_data = k->class_loader_data(); 858 MutexLocker mu(SystemDictionary_lock, THREAD); 859 Klass* kk = find_class(name, loader_data); 860 assert(kk == k(), "should be present in dictionary"); 861 } 862 #endif 863 864 // return if the protection domain in NULL 865 if (protection_domain() == NULL) return k(); 866 867 // Check the protection domain has the right access 868 { 869 MutexLocker mu(SystemDictionary_lock, THREAD); 870 // Note that we have an entry, and entries can be deleted only during GC, 871 // so we cannot allow GC to occur while we're holding this entry. 872 // We're using a No_Safepoint_Verifier to catch any place where we 873 // might potentially do a GC at all. 874 // Dictionary::do_unloading() asserts that classes in SD are only 875 // unloaded at a safepoint. Anonymous classes are not in SD. 876 No_Safepoint_Verifier nosafepoint; 877 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name, 878 loader_data, 879 protection_domain)) { 880 return k(); 881 } 882 } 883 884 // Verify protection domain. If it fails an exception is thrown 885 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL); 886 887 return k(); 888 } 889 890 891 // This routine does not lock the system dictionary. 892 // 893 // Since readers don't hold a lock, we must make sure that system 894 // dictionary entries are only removed at a safepoint (when only one 895 // thread is running), and are added to in a safe way (all links must 896 // be updated in an MT-safe manner). 897 // 898 // Callers should be aware that an entry could be added just after 899 // _dictionary->bucket(index) is read here, so the caller will not see 900 // the new entry. 901 902 Klass* SystemDictionary::find(Symbol* class_name, 903 Handle class_loader, 904 Handle protection_domain, 905 TRAPS) { 906 907 // 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 guarantee(host_klass->class_loader() == class_loader(), "should be the same"); 984 guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping"); 985 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL); 986 loader_data->record_dependency(host_klass(), CHECK_NULL); 987 } else { 988 loader_data = ClassLoaderData::class_loader_data(class_loader()); 989 } 990 991 // Parse the stream. Note that we do this even though this klass might 992 // already be present in the SystemDictionary, otherwise we would not 993 // throw potential ClassFormatErrors. 994 // 995 // Note: "name" is updated. 996 997 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name, 998 loader_data, 999 protection_domain, 1000 host_klass, 1001 cp_patches, 1002 parsed_name, 1003 true, 1004 THREAD); 1005 1006 1007 if (host_klass.not_null() && k.not_null()) { 1008 // If it's anonymous, initialize it now, since nobody else will. 1009 1010 { 1011 MutexLocker mu_r(Compile_lock, THREAD); 1012 1013 // Add to class hierarchy, initialize vtables, and do possible 1014 // deoptimizations. 1015 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block 1016 1017 // But, do not add to system dictionary. 1018 1019 // compiled code dependencies need to be validated anyway 1020 notice_modification(); 1021 } 1022 1023 // Rewrite and patch constant pool here. 1024 k->link_class(CHECK_NULL); 1025 if (cp_patches != NULL) { 1026 k->constants()->patch_resolved_references(cp_patches); 1027 } 1028 k->eager_initialize(CHECK_NULL); 1029 1030 // notify jvmti 1031 if (JvmtiExport::should_post_class_load()) { 1032 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()"); 1033 JvmtiExport::post_class_load((JavaThread *) THREAD, k()); 1034 } 1035 1036 post_class_load_event(class_load_start_time, k, class_loader); 1037 } 1038 assert(host_klass.not_null() || cp_patches == NULL, 1039 "cp_patches only found with host_klass"); 1040 1041 return k(); 1042 } 1043 1044 // Add a klass to the system from a stream (called by jni_DefineClass and 1045 // JVM_DefineClass). 1046 // Note: class_name can be NULL. In that case we do not know the name of 1047 // the class until we have parsed the stream. 1048 1049 Klass* SystemDictionary::resolve_from_stream(Symbol* class_name, 1050 Handle class_loader, 1051 Handle protection_domain, 1052 ClassFileStream* st, 1053 bool verify, 1054 TRAPS) { 1055 1056 // Classloaders that support parallelism, e.g. bootstrap classloader, 1057 // or all classloaders with UnsyncloadClass do not acquire lock here 1058 bool DoObjectLock = true; 1059 if (is_parallelCapable(class_loader)) { 1060 DoObjectLock = false; 1061 } 1062 1063 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL); 1064 1065 // Make sure we are synchronized on the class loader before we proceed 1066 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 1067 check_loader_lock_contention(lockObject, THREAD); 1068 ObjectLocker ol(lockObject, THREAD, DoObjectLock); 1069 1070 TempNewSymbol parsed_name = NULL; 1071 1072 // Parse the stream. Note that we do this even though this klass might 1073 // already be present in the SystemDictionary, otherwise we would not 1074 // throw potential ClassFormatErrors. 1075 // 1076 // Note: "name" is updated. 1077 1078 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name, 1079 loader_data, 1080 protection_domain, 1081 parsed_name, 1082 verify, 1083 THREAD); 1084 1085 const char* pkg = "java/"; 1086 if (!HAS_PENDING_EXCEPTION && 1087 !class_loader.is_null() && 1088 parsed_name != NULL && 1089 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) { 1090 // It is illegal to define classes in the "java." package from 1091 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader 1092 ResourceMark rm(THREAD); 1093 char* name = parsed_name->as_C_string(); 1094 char* index = strrchr(name, '/'); 1095 *index = '\0'; // chop to just the package name 1096 while ((index = strchr(name, '/')) != NULL) { 1097 *index = '.'; // replace '/' with '.' in package name 1098 } 1099 const char* fmt = "Prohibited package name: %s"; 1100 size_t len = strlen(fmt) + strlen(name); 1101 char* message = NEW_RESOURCE_ARRAY(char, len); 1102 jio_snprintf(message, len, fmt, name); 1103 Exceptions::_throw_msg(THREAD_AND_LOCATION, 1104 vmSymbols::java_lang_SecurityException(), message); 1105 } 1106 1107 if (!HAS_PENDING_EXCEPTION) { 1108 assert(parsed_name != NULL, "Sanity"); 1109 assert(class_name == NULL || class_name == parsed_name, "name mismatch"); 1110 // Verification prevents us from creating names with dots in them, this 1111 // asserts that that's the case. 1112 assert(is_internal_format(parsed_name), 1113 "external class name format used internally"); 1114 1115 // Add class just loaded 1116 // If a class loader supports parallel classloading handle parallel define requests 1117 // find_or_define_instance_class may return a different InstanceKlass 1118 if (is_parallelCapable(class_loader)) { 1119 k = find_or_define_instance_class(class_name, class_loader, k, THREAD); 1120 } else { 1121 define_instance_class(k, THREAD); 1122 } 1123 } 1124 1125 // Make sure we have an entry in the SystemDictionary on success 1126 debug_only( { 1127 if (!HAS_PENDING_EXCEPTION) { 1128 assert(parsed_name != NULL, "parsed_name is still null?"); 1129 Symbol* h_name = k->name(); 1130 ClassLoaderData *defining_loader_data = k->class_loader_data(); 1131 1132 MutexLocker mu(SystemDictionary_lock, THREAD); 1133 1134 Klass* check = find_class(parsed_name, loader_data); 1135 assert(check == k(), "should be present in the dictionary"); 1136 1137 Klass* check2 = find_class(h_name, defining_loader_data); 1138 assert(check == check2, "name inconsistancy in SystemDictionary"); 1139 } 1140 } ); 1141 1142 return k(); 1143 } 1144 1145 #if INCLUDE_CDS 1146 void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 1147 int number_of_entries) { 1148 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>), 1149 "bad shared dictionary size."); 1150 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries); 1151 } 1152 1153 1154 // If there is a shared dictionary, then find the entry for the 1155 // given shared system class, if any. 1156 1157 Klass* SystemDictionary::find_shared_class(Symbol* class_name) { 1158 if (shared_dictionary() != NULL) { 1159 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL); 1160 int d_index = shared_dictionary()->hash_to_index(d_hash); 1161 1162 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name); 1163 } else { 1164 return NULL; 1165 } 1166 } 1167 1168 1169 // Load a class from the shared spaces (found through the shared system 1170 // dictionary). Force the superclass and all interfaces to be loaded. 1171 // Update the class definition to include sibling classes and no 1172 // subclasses (yet). [Classes in the shared space are not part of the 1173 // object hierarchy until loaded.] 1174 1175 instanceKlassHandle SystemDictionary::load_shared_class( 1176 Symbol* class_name, Handle class_loader, TRAPS) { 1177 instanceKlassHandle ik (THREAD, find_shared_class(class_name)); 1178 // Make sure we only return the boot class for the NULL classloader. 1179 if (ik.not_null() && 1180 SharedClassUtil::is_shared_boot_class(ik()) && class_loader.is_null()) { 1181 Handle protection_domain; 1182 return load_shared_class(ik, class_loader, protection_domain, THREAD); 1183 } 1184 return instanceKlassHandle(); 1185 } 1186 1187 instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik, 1188 Handle class_loader, 1189 Handle protection_domain, TRAPS) { 1190 if (ik.not_null()) { 1191 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 1192 Symbol* class_name = ik->name(); 1193 1194 // Found the class, now load the superclass and interfaces. If they 1195 // are shared, add them to the main system dictionary and reset 1196 // their hierarchy references (supers, subs, and interfaces). 1197 1198 if (ik->super() != NULL) { 1199 Symbol* cn = ik->super()->name(); 1200 resolve_super_or_fail(class_name, cn, 1201 class_loader, protection_domain, true, CHECK_(nh)); 1202 } 1203 1204 Array<Klass*>* interfaces = ik->local_interfaces(); 1205 int num_interfaces = interfaces->length(); 1206 for (int index = 0; index < num_interfaces; index++) { 1207 Klass* k = interfaces->at(index); 1208 1209 // Note: can not use InstanceKlass::cast here because 1210 // interfaces' InstanceKlass's C++ vtbls haven't been 1211 // reinitialized yet (they will be once the interface classes 1212 // are loaded) 1213 Symbol* name = k->name(); 1214 resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh)); 1215 } 1216 1217 // Adjust methods to recover missing data. They need addresses for 1218 // interpreter entry points and their default native method address 1219 // must be reset. 1220 1221 // Updating methods must be done under a lock so multiple 1222 // threads don't update these in parallel 1223 // 1224 // Shared classes are all currently loaded by either the bootstrap or 1225 // internal parallel class loaders, so this will never cause a deadlock 1226 // on a custom class loader lock. 1227 1228 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader()); 1229 { 1230 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 1231 check_loader_lock_contention(lockObject, THREAD); 1232 ObjectLocker ol(lockObject, THREAD, true); 1233 ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh)); 1234 } 1235 1236 if (TraceClassLoading) { 1237 ResourceMark rm; 1238 tty->print("[Loaded %s", ik->external_name()); 1239 tty->print(" from shared objects file"); 1240 if (class_loader.not_null()) { 1241 tty->print(" by %s", loader_data->loader_name()); 1242 } 1243 tty->print_cr("]"); 1244 } 1245 1246 #if INCLUDE_CDS 1247 if (DumpLoadedClassList != NULL && classlist_file->is_open()) { 1248 // Only dump the classes that can be stored into CDS archive 1249 if (SystemDictionaryShared::is_sharing_possible(loader_data)) { 1250 ResourceMark rm(THREAD); 1251 classlist_file->print_cr("%s", ik->name()->as_C_string()); 1252 classlist_file->flush(); 1253 } 1254 } 1255 #endif 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 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 // if multiple threads calling this function, only one thread will load 1799 // the class. The other threads will find the loaded version once the 1800 // class is loaded. 1801 Klass* aos = _abstract_ownable_synchronizer_klass; 1802 if (aos == NULL) { 1803 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK); 1804 // Force a fence to prevent any read before the write completes 1805 OrderAccess::fence(); 1806 _abstract_ownable_synchronizer_klass = k; 1807 } 1808 } 1809 1810 // ---------------------------------------------------------------------------- 1811 // Initialization 1812 1813 void SystemDictionary::initialize(TRAPS) { 1814 // Allocate arrays 1815 assert(dictionary() == NULL, 1816 "SystemDictionary should only be initialized once"); 1817 _sdgeneration = 0; 1818 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount)); 1819 _placeholders = new PlaceholderTable(_nof_buckets); 1820 _number_of_modifications = 0; 1821 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size); 1822 _resolution_errors = new ResolutionErrorTable(_resolution_error_size); 1823 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size); 1824 1825 // Allocate private object used as system class loader lock 1826 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK); 1827 // Initialize basic classes 1828 initialize_preloaded_classes(CHECK); 1829 } 1830 1831 // Compact table of directions on the initialization of klasses: 1832 static const short wk_init_info[] = { 1833 #define WK_KLASS_INIT_INFO(name, symbol, option) \ 1834 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \ 1835 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \ 1836 | (int)SystemDictionary::option ), 1837 WK_KLASSES_DO(WK_KLASS_INIT_INFO) 1838 #undef WK_KLASS_INIT_INFO 1839 0 1840 }; 1841 1842 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) { 1843 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 1844 int info = wk_init_info[id - FIRST_WKID]; 1845 int sid = (info >> CEIL_LG_OPTION_LIMIT); 1846 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid); 1847 Klass** klassp = &_well_known_klasses[id]; 1848 bool must_load = (init_opt < SystemDictionary::Opt); 1849 if ((*klassp) == NULL) { 1850 if (must_load) { 1851 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class 1852 } else { 1853 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass 1854 } 1855 } 1856 return ((*klassp) != NULL); 1857 } 1858 1859 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) { 1860 assert((int)start_id <= (int)limit_id, "IDs are out of order!"); 1861 for (int id = (int)start_id; id < (int)limit_id; id++) { 1862 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 1863 int info = wk_init_info[id - FIRST_WKID]; 1864 int sid = (info >> CEIL_LG_OPTION_LIMIT); 1865 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT)); 1866 1867 initialize_wk_klass((WKID)id, opt, CHECK); 1868 } 1869 1870 // move the starting value forward to the limit: 1871 start_id = limit_id; 1872 } 1873 1874 void SystemDictionary::initialize_preloaded_classes(TRAPS) { 1875 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once"); 1876 // Preload commonly used klasses 1877 WKID scan = FIRST_WKID; 1878 // first do Object, then String, Class 1879 if (UseSharedSpaces) { 1880 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK); 1881 // Initialize the constant pool for the Object_class 1882 InstanceKlass* ik = InstanceKlass::cast(Object_klass()); 1883 ik->constants()->restore_unshareable_info(CHECK); 1884 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK); 1885 } else { 1886 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK); 1887 } 1888 1889 // Calculate offsets for String and Class classes since they are loaded and 1890 // can be used after this point. 1891 java_lang_String::compute_offsets(); 1892 java_lang_Class::compute_offsets(); 1893 1894 // Fixup mirrors for classes loaded before java.lang.Class. 1895 // These calls iterate over the objects currently in the perm gen 1896 // so calling them at this point is matters (not before when there 1897 // are fewer objects and not later after there are more objects 1898 // in the perm gen. 1899 Universe::initialize_basic_type_mirrors(CHECK); 1900 Universe::fixup_mirrors(CHECK); 1901 1902 // do a bunch more: 1903 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK); 1904 1905 // Preload ref klasses and set reference types 1906 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER); 1907 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass)); 1908 1909 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK); 1910 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT); 1911 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK); 1912 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL); 1913 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM); 1914 1915 // JSR 292 classes 1916 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass); 1917 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass); 1918 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK); 1919 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK); 1920 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK); 1921 1922 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass); 1923 _box_klasses[T_CHAR] = WK_KLASS(Character_klass); 1924 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass); 1925 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass); 1926 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass); 1927 _box_klasses[T_SHORT] = WK_KLASS(Short_klass); 1928 _box_klasses[T_INT] = WK_KLASS(Integer_klass); 1929 _box_klasses[T_LONG] = WK_KLASS(Long_klass); 1930 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass); 1931 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass); 1932 1933 { // Compute whether we should use loadClass or loadClassInternal when loading classes. 1934 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature()); 1935 _has_loadClassInternal = (method != NULL); 1936 } 1937 { // Compute whether we should use checkPackageAccess or NOT 1938 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature()); 1939 _has_checkPackageAccess = (method != NULL); 1940 } 1941 } 1942 1943 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer). 1944 // If so, returns the basic type it holds. If not, returns T_OBJECT. 1945 BasicType SystemDictionary::box_klass_type(Klass* k) { 1946 assert(k != NULL, ""); 1947 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 1948 if (_box_klasses[i] == k) 1949 return (BasicType)i; 1950 } 1951 return T_OBJECT; 1952 } 1953 1954 // Constraints on class loaders. The details of the algorithm can be 1955 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java 1956 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is 1957 // that the system dictionary needs to maintain a set of contraints that 1958 // must be satisfied by all classes in the dictionary. 1959 // if defining is true, then LinkageError if already in systemDictionary 1960 // if initiating loader, then ok if InstanceKlass matches existing entry 1961 1962 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash, 1963 instanceKlassHandle k, 1964 Handle class_loader, bool defining, 1965 TRAPS) { 1966 const char *linkage_error = NULL; 1967 { 1968 Symbol* name = k->name(); 1969 ClassLoaderData *loader_data = class_loader_data(class_loader); 1970 1971 MutexLocker mu(SystemDictionary_lock, THREAD); 1972 1973 Klass* check = find_class(d_index, d_hash, name, loader_data); 1974 if (check != (Klass*)NULL) { 1975 // if different InstanceKlass - duplicate class definition, 1976 // else - ok, class loaded by a different thread in parallel, 1977 // we should only have found it if it was done loading and ok to use 1978 // system dictionary only holds instance classes, placeholders 1979 // also holds array classes 1980 1981 assert(check->oop_is_instance(), "noninstance in systemdictionary"); 1982 if ((defining == true) || (k() != check)) { 1983 linkage_error = "loader (instance of %s): attempted duplicate class " 1984 "definition for name: \"%s\""; 1985 } else { 1986 return; 1987 } 1988 } 1989 1990 #ifdef ASSERT 1991 Symbol* ph_check = find_placeholder(name, loader_data); 1992 assert(ph_check == NULL || ph_check == name, "invalid symbol"); 1993 #endif 1994 1995 if (linkage_error == NULL) { 1996 if (constraints()->check_or_update(k, class_loader, name) == false) { 1997 linkage_error = "loader constraint violation: loader (instance of %s)" 1998 " previously initiated loading for a different type with name \"%s\""; 1999 } 2000 } 2001 } 2002 2003 // Throw error now if needed (cannot throw while holding 2004 // SystemDictionary_lock because of rank ordering) 2005 2006 if (linkage_error) { 2007 ResourceMark rm(THREAD); 2008 const char* class_loader_name = loader_name(class_loader()); 2009 char* type_name = k->name()->as_C_string(); 2010 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) + 2011 strlen(type_name); 2012 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen); 2013 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name); 2014 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf); 2015 } 2016 } 2017 2018 2019 // Update system dictionary - done after check_constraint and add_to_hierachy 2020 // have been called. 2021 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash, 2022 int p_index, unsigned int p_hash, 2023 instanceKlassHandle k, 2024 Handle class_loader, 2025 TRAPS) { 2026 // Compile_lock prevents systemDictionary updates during compilations 2027 assert_locked_or_safepoint(Compile_lock); 2028 Symbol* name = k->name(); 2029 ClassLoaderData *loader_data = class_loader_data(class_loader); 2030 2031 { 2032 MutexLocker mu1(SystemDictionary_lock, THREAD); 2033 2034 // See whether biased locking is enabled and if so set it for this 2035 // klass. 2036 // Note that this must be done past the last potential blocking 2037 // point / safepoint. We enable biased locking lazily using a 2038 // VM_Operation to iterate the SystemDictionary and installing the 2039 // biasable mark word into each InstanceKlass's prototype header. 2040 // To avoid race conditions where we accidentally miss enabling the 2041 // optimization for one class in the process of being added to the 2042 // dictionary, we must not safepoint after the test of 2043 // BiasedLocking::enabled(). 2044 if (UseBiasedLocking && BiasedLocking::enabled()) { 2045 // Set biased locking bit for all loaded classes; it will be 2046 // cleared if revocation occurs too often for this type 2047 // NOTE that we must only do this when the class is initally 2048 // defined, not each time it is referenced from a new class loader 2049 if (k->class_loader() == class_loader()) { 2050 k->set_prototype_header(markOopDesc::biased_locking_prototype()); 2051 } 2052 } 2053 2054 // Make a new system dictionary entry. 2055 Klass* sd_check = find_class(d_index, d_hash, name, loader_data); 2056 if (sd_check == NULL) { 2057 dictionary()->add_klass(name, loader_data, k); 2058 notice_modification(); 2059 } 2060 #ifdef ASSERT 2061 sd_check = find_class(d_index, d_hash, name, loader_data); 2062 assert (sd_check != NULL, "should have entry in system dictionary"); 2063 // Note: there may be a placeholder entry: for circularity testing 2064 // or for parallel defines 2065 #endif 2066 SystemDictionary_lock->notify_all(); 2067 } 2068 } 2069 2070 2071 // Try to find a class name using the loader constraints. The 2072 // loader constraints might know about a class that isn't fully loaded 2073 // yet and these will be ignored. 2074 Klass* SystemDictionary::find_constrained_instance_or_array_klass( 2075 Symbol* class_name, Handle class_loader, TRAPS) { 2076 2077 // First see if it has been loaded directly. 2078 // Force the protection domain to be null. (This removes protection checks.) 2079 Handle no_protection_domain; 2080 Klass* klass = find_instance_or_array_klass(class_name, class_loader, 2081 no_protection_domain, CHECK_NULL); 2082 if (klass != NULL) 2083 return klass; 2084 2085 // Now look to see if it has been loaded elsewhere, and is subject to 2086 // a loader constraint that would require this loader to return the 2087 // klass that is already loaded. 2088 if (FieldType::is_array(class_name)) { 2089 // For array classes, their Klass*s are not kept in the 2090 // constraint table. The element Klass*s are. 2091 FieldArrayInfo fd; 2092 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL)); 2093 if (t != T_OBJECT) { 2094 klass = Universe::typeArrayKlassObj(t); 2095 } else { 2096 MutexLocker mu(SystemDictionary_lock, THREAD); 2097 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader); 2098 } 2099 // If element class already loaded, allocate array klass 2100 if (klass != NULL) { 2101 klass = klass->array_klass_or_null(fd.dimension()); 2102 } 2103 } else { 2104 MutexLocker mu(SystemDictionary_lock, THREAD); 2105 // Non-array classes are easy: simply check the constraint table. 2106 klass = constraints()->find_constrained_klass(class_name, class_loader); 2107 } 2108 2109 return klass; 2110 } 2111 2112 2113 bool SystemDictionary::add_loader_constraint(Symbol* class_name, 2114 Handle class_loader1, 2115 Handle class_loader2, 2116 Thread* THREAD) { 2117 ClassLoaderData* loader_data1 = class_loader_data(class_loader1); 2118 ClassLoaderData* loader_data2 = class_loader_data(class_loader2); 2119 2120 Symbol* constraint_name = NULL; 2121 if (!FieldType::is_array(class_name)) { 2122 constraint_name = class_name; 2123 } else { 2124 // For array classes, their Klass*s are not kept in the 2125 // constraint table. The element classes are. 2126 FieldArrayInfo fd; 2127 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false)); 2128 // primitive types always pass 2129 if (t != T_OBJECT) { 2130 return true; 2131 } else { 2132 constraint_name = fd.object_key(); 2133 } 2134 } 2135 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1); 2136 int d_index1 = dictionary()->hash_to_index(d_hash1); 2137 2138 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2); 2139 int d_index2 = dictionary()->hash_to_index(d_hash2); 2140 { 2141 MutexLocker mu_s(SystemDictionary_lock, THREAD); 2142 2143 // Better never do a GC while we're holding these oops 2144 No_Safepoint_Verifier nosafepoint; 2145 2146 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1); 2147 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2); 2148 return constraints()->add_entry(constraint_name, klass1, class_loader1, 2149 klass2, class_loader2); 2150 } 2151 } 2152 2153 // Add entry to resolution error table to record the error when the first 2154 // attempt to resolve a reference to a class has failed. 2155 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, 2156 Symbol* error, Symbol* message) { 2157 unsigned int hash = resolution_errors()->compute_hash(pool, which); 2158 int index = resolution_errors()->hash_to_index(hash); 2159 { 2160 MutexLocker ml(SystemDictionary_lock, Thread::current()); 2161 resolution_errors()->add_entry(index, hash, pool, which, error, message); 2162 } 2163 } 2164 2165 // Delete a resolution error for RedefineClasses for a constant pool is going away 2166 void SystemDictionary::delete_resolution_error(ConstantPool* pool) { 2167 resolution_errors()->delete_entry(pool); 2168 } 2169 2170 // Lookup resolution error table. Returns error if found, otherwise NULL. 2171 Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int which, 2172 Symbol** message) { 2173 unsigned int hash = resolution_errors()->compute_hash(pool, which); 2174 int index = resolution_errors()->hash_to_index(hash); 2175 { 2176 MutexLocker ml(SystemDictionary_lock, Thread::current()); 2177 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which); 2178 if (entry != NULL) { 2179 *message = entry->message(); 2180 return entry->error(); 2181 } else { 2182 return NULL; 2183 } 2184 } 2185 } 2186 2187 2188 // Signature constraints ensure that callers and callees agree about 2189 // the meaning of type names in their signatures. This routine is the 2190 // intake for constraints. It collects them from several places: 2191 // 2192 // * LinkResolver::resolve_method (if check_access is true) requires 2193 // that the resolving class (the caller) and the defining class of 2194 // the resolved method (the callee) agree on each type in the 2195 // method's signature. 2196 // 2197 // * LinkResolver::resolve_interface_method performs exactly the same 2198 // checks. 2199 // 2200 // * LinkResolver::resolve_field requires that the constant pool 2201 // attempting to link to a field agree with the field's defining 2202 // class about the type of the field signature. 2203 // 2204 // * klassVtable::initialize_vtable requires that, when a class 2205 // overrides a vtable entry allocated by a superclass, that the 2206 // overriding method (i.e., the callee) agree with the superclass 2207 // on each type in the method's signature. 2208 // 2209 // * klassItable::initialize_itable requires that, when a class fills 2210 // in its itables, for each non-abstract method installed in an 2211 // itable, the method (i.e., the callee) agree with the interface 2212 // on each type in the method's signature. 2213 // 2214 // All those methods have a boolean (check_access, checkconstraints) 2215 // which turns off the checks. This is used from specialized contexts 2216 // such as bootstrapping, dumping, and debugging. 2217 // 2218 // No direct constraint is placed between the class and its 2219 // supertypes. Constraints are only placed along linked relations 2220 // between callers and callees. When a method overrides or implements 2221 // an abstract method in a supertype (superclass or interface), the 2222 // constraints are placed as if the supertype were the caller to the 2223 // overriding method. (This works well, since callers to the 2224 // supertype have already established agreement between themselves and 2225 // the supertype.) As a result of all this, a class can disagree with 2226 // its supertype about the meaning of a type name, as long as that 2227 // class neither calls a relevant method of the supertype, nor is 2228 // called (perhaps via an override) from the supertype. 2229 // 2230 // 2231 // SystemDictionary::check_signature_loaders(sig, l1, l2) 2232 // 2233 // Make sure all class components (including arrays) in the given 2234 // signature will be resolved to the same class in both loaders. 2235 // Returns the name of the type that failed a loader constraint check, or 2236 // NULL if no constraint failed. No exception except OOME is thrown. 2237 // Arrays are not added to the loader constraint table, their elements are. 2238 Symbol* SystemDictionary::check_signature_loaders(Symbol* signature, 2239 Handle loader1, Handle loader2, 2240 bool is_method, TRAPS) { 2241 // Nothing to do if loaders are the same. 2242 if (loader1() == loader2()) { 2243 return NULL; 2244 } 2245 2246 SignatureStream sig_strm(signature, is_method); 2247 while (!sig_strm.is_done()) { 2248 if (sig_strm.is_object()) { 2249 Symbol* sig = sig_strm.as_symbol(CHECK_NULL); 2250 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) { 2251 return sig; 2252 } 2253 } 2254 sig_strm.next(); 2255 } 2256 return NULL; 2257 } 2258 2259 2260 methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid, 2261 Symbol* signature, 2262 TRAPS) { 2263 methodHandle empty; 2264 assert(MethodHandles::is_signature_polymorphic(iid) && 2265 MethodHandles::is_signature_polymorphic_intrinsic(iid) && 2266 iid != vmIntrinsics::_invokeGeneric, 2267 err_msg("must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid))); 2268 2269 unsigned int hash = invoke_method_table()->compute_hash(signature, iid); 2270 int index = invoke_method_table()->hash_to_index(hash); 2271 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid); 2272 methodHandle m; 2273 if (spe == NULL || spe->method() == NULL) { 2274 spe = NULL; 2275 // Must create lots of stuff here, but outside of the SystemDictionary lock. 2276 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty)); 2277 CompileBroker::compile_method(m, InvocationEntryBci, CompLevel_highest_tier, 2278 methodHandle(), CompileThreshold, "MH", CHECK_(empty)); 2279 2280 // Now grab the lock. We might have to throw away the new method, 2281 // if a racing thread has managed to install one at the same time. 2282 { 2283 MutexLocker ml(SystemDictionary_lock, THREAD); 2284 spe = invoke_method_table()->find_entry(index, hash, signature, iid); 2285 if (spe == NULL) 2286 spe = invoke_method_table()->add_entry(index, hash, signature, iid); 2287 if (spe->method() == NULL) 2288 spe->set_method(m()); 2289 } 2290 } 2291 2292 assert(spe != NULL && spe->method() != NULL, ""); 2293 return spe->method(); 2294 } 2295 2296 // Helper for unpacking the return value from linkMethod and linkCallSite. 2297 static methodHandle unpack_method_and_appendix(Handle mname, 2298 KlassHandle accessing_klass, 2299 objArrayHandle appendix_box, 2300 Handle* appendix_result, 2301 TRAPS) { 2302 methodHandle empty; 2303 if (mname.not_null()) { 2304 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname()); 2305 if (vmtarget != NULL && vmtarget->is_method()) { 2306 Method* m = (Method*)vmtarget; 2307 oop appendix = appendix_box->obj_at(0); 2308 if (TraceMethodHandles) { 2309 #ifndef PRODUCT 2310 tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m)); 2311 m->print(); 2312 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); } 2313 tty->cr(); 2314 #endif //PRODUCT 2315 } 2316 (*appendix_result) = Handle(THREAD, appendix); 2317 // the target is stored in the cpCache and if a reference to this 2318 // MethodName is dropped we need a way to make sure the 2319 // class_loader containing this method is kept alive. 2320 // FIXME: the appendix might also preserve this dependency. 2321 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data(); 2322 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM 2323 return methodHandle(THREAD, m); 2324 } 2325 } 2326 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty); 2327 return empty; 2328 } 2329 2330 methodHandle SystemDictionary::find_method_handle_invoker(Symbol* name, 2331 Symbol* signature, 2332 KlassHandle accessing_klass, 2333 Handle *appendix_result, 2334 Handle *method_type_result, 2335 TRAPS) { 2336 methodHandle empty; 2337 assert(!THREAD->is_Compiler_thread(), ""); 2338 Handle method_type = 2339 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty)); 2340 if (false) { // FIXME: Decide if the Java upcall should resolve signatures. 2341 method_type = java_lang_String::create_from_symbol(signature, CHECK_(empty)); 2342 } 2343 2344 KlassHandle mh_klass = SystemDictionary::MethodHandle_klass(); 2345 int ref_kind = JVM_REF_invokeVirtual; 2346 Handle name_str = StringTable::intern(name, CHECK_(empty)); 2347 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty)); 2348 assert(appendix_box->obj_at(0) == NULL, ""); 2349 2350 // This should not happen. JDK code should take care of that. 2351 if (accessing_klass.is_null() || method_type.is_null()) { 2352 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty); 2353 } 2354 2355 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName 2356 JavaCallArguments args; 2357 args.push_oop(accessing_klass()->java_mirror()); 2358 args.push_int(ref_kind); 2359 args.push_oop(mh_klass()->java_mirror()); 2360 args.push_oop(name_str()); 2361 args.push_oop(method_type()); 2362 args.push_oop(appendix_box()); 2363 JavaValue result(T_OBJECT); 2364 JavaCalls::call_static(&result, 2365 SystemDictionary::MethodHandleNatives_klass(), 2366 vmSymbols::linkMethod_name(), 2367 vmSymbols::linkMethod_signature(), 2368 &args, CHECK_(empty)); 2369 Handle mname(THREAD, (oop) result.get_jobject()); 2370 (*method_type_result) = method_type; 2371 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD); 2372 } 2373 2374 2375 // Ask Java code to find or construct a java.lang.invoke.MethodType for the given 2376 // signature, as interpreted relative to the given class loader. 2377 // Because of class loader constraints, all method handle usage must be 2378 // consistent with this loader. 2379 Handle SystemDictionary::find_method_handle_type(Symbol* signature, 2380 KlassHandle accessing_klass, 2381 TRAPS) { 2382 Handle empty; 2383 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics 2384 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid); 2385 int index = invoke_method_table()->hash_to_index(hash); 2386 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid); 2387 if (spe != NULL && spe->method_type() != NULL) { 2388 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), ""); 2389 return Handle(THREAD, spe->method_type()); 2390 } else if (THREAD->is_Compiler_thread()) { 2391 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME 2392 return Handle(); // do not attempt from within compiler, unless it was cached 2393 } 2394 2395 Handle class_loader, protection_domain; 2396 bool is_on_bcp = true; // keep this true as long as we can materialize from the boot classloader 2397 int npts = ArgumentCount(signature).size(); 2398 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty)); 2399 int arg = 0; 2400 Handle rt; // the return type from the signature 2401 ResourceMark rm(THREAD); 2402 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) { 2403 oop mirror = NULL; 2404 if (is_on_bcp) { 2405 // Note: class_loader & protection_domain are both null at this point. 2406 mirror = ss.as_java_mirror(class_loader, protection_domain, 2407 SignatureStream::ReturnNull, CHECK_(empty)); 2408 if (mirror == NULL) { 2409 // fall back from BCP to accessing_klass 2410 if (accessing_klass.not_null()) { 2411 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader()); 2412 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain()); 2413 } 2414 is_on_bcp = false; 2415 } 2416 } 2417 if (!is_on_bcp) { 2418 // Resolve, throwing a real error if it doesn't work. 2419 mirror = ss.as_java_mirror(class_loader, protection_domain, 2420 SignatureStream::NCDFError, CHECK_(empty)); 2421 } 2422 if (ss.at_return_type()) 2423 rt = Handle(THREAD, mirror); 2424 else 2425 pts->obj_at_put(arg++, mirror); 2426 2427 // Check accessibility. 2428 if (ss.is_object() && accessing_klass.not_null()) { 2429 Klass* sel_klass = java_lang_Class::as_Klass(mirror); 2430 mirror = NULL; // safety 2431 // Emulate ConstantPool::verify_constant_pool_resolve. 2432 if (sel_klass->oop_is_objArray()) 2433 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass(); 2434 if (sel_klass->oop_is_instance()) { 2435 KlassHandle sel_kh(THREAD, sel_klass); 2436 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty)); 2437 } 2438 } 2439 } 2440 assert(arg == npts, ""); 2441 2442 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType 2443 JavaCallArguments args(Handle(THREAD, rt())); 2444 args.push_oop(pts()); 2445 JavaValue result(T_OBJECT); 2446 JavaCalls::call_static(&result, 2447 SystemDictionary::MethodHandleNatives_klass(), 2448 vmSymbols::findMethodHandleType_name(), 2449 vmSymbols::findMethodHandleType_signature(), 2450 &args, CHECK_(empty)); 2451 Handle method_type(THREAD, (oop) result.get_jobject()); 2452 2453 if (is_on_bcp) { 2454 // We can cache this MethodType inside the JVM. 2455 MutexLocker ml(SystemDictionary_lock, THREAD); 2456 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid); 2457 if (spe == NULL) 2458 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid); 2459 if (spe->method_type() == NULL) { 2460 spe->set_method_type(method_type()); 2461 } 2462 } 2463 2464 // report back to the caller with the MethodType 2465 return method_type; 2466 } 2467 2468 // Ask Java code to find or construct a method handle constant. 2469 Handle SystemDictionary::link_method_handle_constant(KlassHandle caller, 2470 int ref_kind, //e.g., JVM_REF_invokeVirtual 2471 KlassHandle callee, 2472 Symbol* name_sym, 2473 Symbol* signature, 2474 TRAPS) { 2475 Handle empty; 2476 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty)); 2477 Handle type; 2478 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') { 2479 type = find_method_handle_type(signature, caller, CHECK_(empty)); 2480 } else if (caller.is_null()) { 2481 // This should not happen. JDK code should take care of that. 2482 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty); 2483 } else { 2484 ResourceMark rm(THREAD); 2485 SignatureStream ss(signature, false); 2486 if (!ss.is_done()) { 2487 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(), 2488 SignatureStream::NCDFError, CHECK_(empty)); 2489 type = Handle(THREAD, mirror); 2490 ss.next(); 2491 if (!ss.is_done()) type = Handle(); // error! 2492 } 2493 } 2494 if (type.is_null()) { 2495 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty); 2496 } 2497 2498 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle 2499 JavaCallArguments args; 2500 args.push_oop(caller->java_mirror()); // the referring class 2501 args.push_int(ref_kind); 2502 args.push_oop(callee->java_mirror()); // the target class 2503 args.push_oop(name()); 2504 args.push_oop(type()); 2505 JavaValue result(T_OBJECT); 2506 JavaCalls::call_static(&result, 2507 SystemDictionary::MethodHandleNatives_klass(), 2508 vmSymbols::linkMethodHandleConstant_name(), 2509 vmSymbols::linkMethodHandleConstant_signature(), 2510 &args, CHECK_(empty)); 2511 return Handle(THREAD, (oop) result.get_jobject()); 2512 } 2513 2514 // Ask Java code to find or construct a java.lang.invoke.CallSite for the given 2515 // name and signature, as interpreted relative to the given class loader. 2516 methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller, 2517 Handle bootstrap_specifier, 2518 Symbol* name, 2519 Symbol* type, 2520 Handle *appendix_result, 2521 Handle *method_type_result, 2522 TRAPS) { 2523 methodHandle empty; 2524 Handle bsm, info; 2525 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) { 2526 bsm = bootstrap_specifier; 2527 } else { 2528 assert(bootstrap_specifier->is_objArray(), ""); 2529 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier()); 2530 int len = args->length(); 2531 assert(len >= 1, ""); 2532 bsm = Handle(THREAD, args->obj_at(0)); 2533 if (len > 1) { 2534 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty)); 2535 for (int i = 1; i < len; i++) 2536 args1->obj_at_put(i-1, args->obj_at(i)); 2537 info = Handle(THREAD, args1); 2538 } 2539 } 2540 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()), 2541 "caller must supply a valid BSM"); 2542 2543 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty)); 2544 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty)); 2545 2546 // This should not happen. JDK code should take care of that. 2547 if (caller.is_null() || method_type.is_null()) { 2548 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty); 2549 } 2550 2551 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty)); 2552 assert(appendix_box->obj_at(0) == NULL, ""); 2553 2554 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix) 2555 JavaCallArguments args; 2556 args.push_oop(caller->java_mirror()); 2557 args.push_oop(bsm()); 2558 args.push_oop(method_name()); 2559 args.push_oop(method_type()); 2560 args.push_oop(info()); 2561 args.push_oop(appendix_box); 2562 JavaValue result(T_OBJECT); 2563 JavaCalls::call_static(&result, 2564 SystemDictionary::MethodHandleNatives_klass(), 2565 vmSymbols::linkCallSite_name(), 2566 vmSymbols::linkCallSite_signature(), 2567 &args, CHECK_(empty)); 2568 Handle mname(THREAD, (oop) result.get_jobject()); 2569 (*method_type_result) = method_type; 2570 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD); 2571 } 2572 2573 // Since the identity hash code for symbols changes when the symbols are 2574 // moved from the regular perm gen (hash in the mark word) to the shared 2575 // spaces (hash is the address), the classes loaded into the dictionary 2576 // may be in the wrong buckets. 2577 2578 void SystemDictionary::reorder_dictionary() { 2579 dictionary()->reorder_dictionary(); 2580 } 2581 2582 2583 void SystemDictionary::copy_buckets(char** top, char* end) { 2584 dictionary()->copy_buckets(top, end); 2585 } 2586 2587 2588 void SystemDictionary::copy_table(char** top, char* end) { 2589 dictionary()->copy_table(top, end); 2590 } 2591 2592 2593 void SystemDictionary::reverse() { 2594 dictionary()->reverse(); 2595 } 2596 2597 int SystemDictionary::number_of_classes() { 2598 return dictionary()->number_of_entries(); 2599 } 2600 2601 2602 // ---------------------------------------------------------------------------- 2603 void SystemDictionary::print_shared(bool details) { 2604 shared_dictionary()->print(details); 2605 } 2606 2607 void SystemDictionary::print(bool details) { 2608 dictionary()->print(details); 2609 2610 // Placeholders 2611 GCMutexLocker mu(SystemDictionary_lock); 2612 placeholders()->print(); 2613 2614 // loader constraints - print under SD_lock 2615 constraints()->print(); 2616 } 2617 2618 2619 void SystemDictionary::verify() { 2620 guarantee(dictionary() != NULL, "Verify of system dictionary failed"); 2621 guarantee(constraints() != NULL, 2622 "Verify of loader constraints failed"); 2623 guarantee(dictionary()->number_of_entries() >= 0 && 2624 placeholders()->number_of_entries() >= 0, 2625 "Verify of system dictionary failed"); 2626 2627 // Verify dictionary 2628 dictionary()->verify(); 2629 2630 GCMutexLocker mu(SystemDictionary_lock); 2631 placeholders()->verify(); 2632 2633 // Verify constraint table 2634 guarantee(constraints() != NULL, "Verify of loader constraints failed"); 2635 constraints()->verify(dictionary(), placeholders()); 2636 } 2637 2638 // utility function for class load event 2639 void SystemDictionary::post_class_load_event(const Ticks& start_time, 2640 instanceKlassHandle k, 2641 Handle initiating_loader) { 2642 #if INCLUDE_TRACE 2643 EventClassLoad event(UNTIMED); 2644 if (event.should_commit()) { 2645 event.set_starttime(start_time); 2646 event.set_loadedClass(k()); 2647 oop defining_class_loader = k->class_loader(); 2648 event.set_definingClassLoader(defining_class_loader != NULL ? 2649 defining_class_loader->klass() : (Klass*)NULL); 2650 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader(); 2651 event.set_initiatingClassLoader(class_loader != NULL ? 2652 class_loader->klass() : (Klass*)NULL); 2653 event.commit(); 2654 } 2655 #endif /* INCLUDE_TRACE */ 2656 } 2657 2658 #ifndef PRODUCT 2659 2660 // statistics code 2661 class ClassStatistics: AllStatic { 2662 private: 2663 static int nclasses; // number of classes 2664 static int nmethods; // number of methods 2665 static int nmethoddata; // number of methodData 2666 static int class_size; // size of class objects in words 2667 static int method_size; // size of method objects in words 2668 static int debug_size; // size of debug info in methods 2669 static int methoddata_size; // size of methodData objects in words 2670 2671 static void do_class(Klass* k) { 2672 nclasses++; 2673 class_size += k->size(); 2674 if (k->oop_is_instance()) { 2675 InstanceKlass* ik = (InstanceKlass*)k; 2676 class_size += ik->methods()->size(); 2677 class_size += ik->constants()->size(); 2678 class_size += ik->local_interfaces()->size(); 2679 class_size += ik->transitive_interfaces()->size(); 2680 // We do not have to count implementors, since we only store one! 2681 // SSS: How should these be accounted now that they have moved? 2682 // class_size += ik->fields()->length(); 2683 } 2684 } 2685 2686 static void do_method(Method* m) { 2687 nmethods++; 2688 method_size += m->size(); 2689 // class loader uses same objArray for empty vectors, so don't count these 2690 if (m->has_stackmap_table()) { 2691 method_size += m->stackmap_data()->size(); 2692 } 2693 2694 MethodData* mdo = m->method_data(); 2695 if (mdo != NULL) { 2696 nmethoddata++; 2697 methoddata_size += mdo->size(); 2698 } 2699 } 2700 2701 public: 2702 static void print() { 2703 SystemDictionary::classes_do(do_class); 2704 SystemDictionary::methods_do(do_method); 2705 tty->print_cr("Class statistics:"); 2706 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize); 2707 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods, 2708 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize); 2709 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize); 2710 } 2711 }; 2712 2713 2714 int ClassStatistics::nclasses = 0; 2715 int ClassStatistics::nmethods = 0; 2716 int ClassStatistics::nmethoddata = 0; 2717 int ClassStatistics::class_size = 0; 2718 int ClassStatistics::method_size = 0; 2719 int ClassStatistics::debug_size = 0; 2720 int ClassStatistics::methoddata_size = 0; 2721 2722 void SystemDictionary::print_class_statistics() { 2723 ResourceMark rm; 2724 ClassStatistics::print(); 2725 } 2726 2727 2728 class MethodStatistics: AllStatic { 2729 public: 2730 enum { 2731 max_parameter_size = 10 2732 }; 2733 private: 2734 2735 static int _number_of_methods; 2736 static int _number_of_final_methods; 2737 static int _number_of_static_methods; 2738 static int _number_of_native_methods; 2739 static int _number_of_synchronized_methods; 2740 static int _number_of_profiled_methods; 2741 static int _number_of_bytecodes; 2742 static int _parameter_size_profile[max_parameter_size]; 2743 static int _bytecodes_profile[Bytecodes::number_of_java_codes]; 2744 2745 static void initialize() { 2746 _number_of_methods = 0; 2747 _number_of_final_methods = 0; 2748 _number_of_static_methods = 0; 2749 _number_of_native_methods = 0; 2750 _number_of_synchronized_methods = 0; 2751 _number_of_profiled_methods = 0; 2752 _number_of_bytecodes = 0; 2753 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0; 2754 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0; 2755 }; 2756 2757 static void do_method(Method* m) { 2758 _number_of_methods++; 2759 // collect flag info 2760 if (m->is_final() ) _number_of_final_methods++; 2761 if (m->is_static() ) _number_of_static_methods++; 2762 if (m->is_native() ) _number_of_native_methods++; 2763 if (m->is_synchronized()) _number_of_synchronized_methods++; 2764 if (m->method_data() != NULL) _number_of_profiled_methods++; 2765 // collect parameter size info (add one for receiver, if any) 2766 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++; 2767 // collect bytecodes info 2768 { 2769 Thread *thread = Thread::current(); 2770 HandleMark hm(thread); 2771 BytecodeStream s(methodHandle(thread, m)); 2772 Bytecodes::Code c; 2773 while ((c = s.next()) >= 0) { 2774 _number_of_bytecodes++; 2775 _bytecodes_profile[c]++; 2776 } 2777 } 2778 } 2779 2780 public: 2781 static void print() { 2782 initialize(); 2783 SystemDictionary::methods_do(do_method); 2784 // generate output 2785 tty->cr(); 2786 tty->print_cr("Method statistics (static):"); 2787 // flag distribution 2788 tty->cr(); 2789 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods); 2790 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods); 2791 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods); 2792 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods); 2793 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods); 2794 // parameter size profile 2795 tty->cr(); 2796 { int tot = 0; 2797 int avg = 0; 2798 for (int i = 0; i < max_parameter_size; i++) { 2799 int n = _parameter_size_profile[i]; 2800 tot += n; 2801 avg += n*i; 2802 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods); 2803 } 2804 assert(tot == _number_of_methods, "should be the same"); 2805 tty->print_cr(" %6d methods 100.0%%", _number_of_methods); 2806 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods); 2807 } 2808 // bytecodes profile 2809 tty->cr(); 2810 { int tot = 0; 2811 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) { 2812 if (Bytecodes::is_defined(i)) { 2813 Bytecodes::Code c = Bytecodes::cast(i); 2814 int n = _bytecodes_profile[c]; 2815 tot += n; 2816 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c)); 2817 } 2818 } 2819 assert(tot == _number_of_bytecodes, "should be the same"); 2820 tty->print_cr("%9d 100.000%%", _number_of_bytecodes); 2821 } 2822 tty->cr(); 2823 } 2824 }; 2825 2826 int MethodStatistics::_number_of_methods; 2827 int MethodStatistics::_number_of_final_methods; 2828 int MethodStatistics::_number_of_static_methods; 2829 int MethodStatistics::_number_of_native_methods; 2830 int MethodStatistics::_number_of_synchronized_methods; 2831 int MethodStatistics::_number_of_profiled_methods; 2832 int MethodStatistics::_number_of_bytecodes; 2833 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size]; 2834 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes]; 2835 2836 2837 void SystemDictionary::print_method_statistics() { 2838 MethodStatistics::print(); 2839 } 2840 2841 #endif // PRODUCT