systemDictionary.cpp revision 5932:48314d596a04
1/* 2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#include "precompiled.hpp" 26#include "classfile/classLoaderData.inline.hpp" 27#include "classfile/dictionary.hpp" 28#include "classfile/javaClasses.hpp" 29#include "classfile/loaderConstraints.hpp" 30#include "classfile/placeholders.hpp" 31#include "classfile/resolutionErrors.hpp" 32#include "classfile/systemDictionary.hpp" 33#include "classfile/vmSymbols.hpp" 34#include "compiler/compileBroker.hpp" 35#include "interpreter/bytecodeStream.hpp" 36#include "interpreter/interpreter.hpp" 37#include "memory/gcLocker.hpp" 38#include "memory/oopFactory.hpp" 39#include "oops/instanceKlass.hpp" 40#include "oops/instanceRefKlass.hpp" 41#include "oops/klass.inline.hpp" 42#include "oops/methodData.hpp" 43#include "oops/objArrayKlass.hpp" 44#include "oops/oop.inline.hpp" 45#include "oops/oop.inline2.hpp" 46#include "oops/typeArrayKlass.hpp" 47#include "prims/jvmtiEnvBase.hpp" 48#include "prims/methodHandles.hpp" 49#include "runtime/biasedLocking.hpp" 50#include "runtime/fieldType.hpp" 51#include "runtime/handles.inline.hpp" 52#include "runtime/java.hpp" 53#include "runtime/javaCalls.hpp" 54#include "runtime/mutexLocker.hpp" 55#include "runtime/signature.hpp" 56#include "services/classLoadingService.hpp" 57#include "services/threadService.hpp" 58#include "utilities/macros.hpp" 59#include "utilities/ticks.hpp" 60 61#if INCLUDE_TRACE 62 #include "trace/tracing.hpp" 63#endif 64 65Dictionary* SystemDictionary::_dictionary = NULL; 66PlaceholderTable* SystemDictionary::_placeholders = NULL; 67Dictionary* SystemDictionary::_shared_dictionary = NULL; 68LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL; 69ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL; 70SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL; 71 72 73int SystemDictionary::_number_of_modifications = 0; 74int SystemDictionary::_sdgeneration = 0; 75const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103, 76 20201,40423,99991}; 77 78oop SystemDictionary::_system_loader_lock_obj = NULL; 79 80Klass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT] 81 = { NULL /*, NULL...*/ }; 82 83Klass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ }; 84 85oop SystemDictionary::_java_system_loader = NULL; 86 87bool SystemDictionary::_has_loadClassInternal = false; 88bool SystemDictionary::_has_checkPackageAccess = false; 89 90// lazily initialized klass variables 91Klass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL; 92 93 94// ---------------------------------------------------------------------------- 95// Java-level SystemLoader 96 97oop SystemDictionary::java_system_loader() { 98 return _java_system_loader; 99} 100 101void SystemDictionary::compute_java_system_loader(TRAPS) { 102 KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass)); 103 JavaValue result(T_OBJECT); 104 JavaCalls::call_static(&result, 105 KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)), 106 vmSymbols::getSystemClassLoader_name(), 107 vmSymbols::void_classloader_signature(), 108 CHECK); 109 110 _java_system_loader = (oop)result.get_jobject(); 111} 112 113 114ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) { 115 if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data(); 116 return ClassLoaderDataGraph::find_or_create(class_loader, CHECK_NULL); 117} 118 119// ---------------------------------------------------------------------------- 120// debugging 121 122#ifdef ASSERT 123 124// return true if class_name contains no '.' (internal format is '/') 125bool SystemDictionary::is_internal_format(Symbol* class_name) { 126 if (class_name != NULL) { 127 ResourceMark rm; 128 char* name = class_name->as_C_string(); 129 return strchr(name, '.') == NULL; 130 } else { 131 return true; 132 } 133} 134 135#endif 136 137// ---------------------------------------------------------------------------- 138// Parallel class loading check 139 140bool SystemDictionary::is_parallelCapable(Handle class_loader) { 141 if (UnsyncloadClass || class_loader.is_null()) return true; 142 if (AlwaysLockClassLoader) return false; 143 return java_lang_ClassLoader::parallelCapable(class_loader()); 144} 145// ---------------------------------------------------------------------------- 146// ParallelDefineClass flag does not apply to bootclass loader 147bool SystemDictionary::is_parallelDefine(Handle class_loader) { 148 if (class_loader.is_null()) return false; 149 if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) { 150 return true; 151 } 152 return false; 153} 154 155/** 156 * Returns true if the passed class loader is the extension class loader. 157 */ 158bool SystemDictionary::is_ext_class_loader(Handle class_loader) { 159 if (class_loader.is_null()) { 160 return false; 161 } 162 return (class_loader->klass()->name() == vmSymbols::sun_misc_Launcher_ExtClassLoader()); 163} 164 165// ---------------------------------------------------------------------------- 166// Resolving of classes 167 168// Forwards to resolve_or_null 169 170Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) { 171 Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD); 172 if (HAS_PENDING_EXCEPTION || klass == NULL) { 173 KlassHandle k_h(THREAD, klass); 174 // can return a null klass 175 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD); 176 } 177 return klass; 178} 179 180Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) { 181 if (HAS_PENDING_EXCEPTION) { 182 // If we have a pending exception we forward it to the caller, unless throw_error is true, 183 // in which case we have to check whether the pending exception is a ClassNotFoundException, 184 // and if so convert it to a NoClassDefFoundError 185 // And chain the original ClassNotFoundException 186 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) { 187 ResourceMark rm(THREAD); 188 assert(klass_h() == NULL, "Should not have result with exception pending"); 189 Handle e(THREAD, PENDING_EXCEPTION); 190 CLEAR_PENDING_EXCEPTION; 191 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e); 192 } else { 193 return NULL; 194 } 195 } 196 // Class not found, throw appropriate error or exception depending on value of throw_error 197 if (klass_h() == NULL) { 198 ResourceMark rm(THREAD); 199 if (throw_error) { 200 THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string()); 201 } else { 202 THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string()); 203 } 204 } 205 return (Klass*)klass_h(); 206} 207 208 209Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, 210 bool throw_error, TRAPS) 211{ 212 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD); 213} 214 215 216// Forwards to resolve_instance_class_or_null 217 218Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) { 219 assert(!THREAD->is_Compiler_thread(), 220 err_msg("can not load classes with compiler thread: class=%s, classloader=%s", 221 class_name->as_C_string(), 222 class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string())); 223 if (FieldType::is_array(class_name)) { 224 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL); 225 } else if (FieldType::is_obj(class_name)) { 226 ResourceMark rm(THREAD); 227 // Ignore wrapping L and ;. 228 TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1, 229 class_name->utf8_length() - 2, CHECK_NULL); 230 return resolve_instance_class_or_null(name, class_loader, protection_domain, CHECK_NULL); 231 } else { 232 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL); 233 } 234} 235 236Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) { 237 return resolve_or_null(class_name, Handle(), Handle(), THREAD); 238} 239 240// Forwards to resolve_instance_class_or_null 241 242Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name, 243 Handle class_loader, 244 Handle protection_domain, 245 TRAPS) { 246 assert(FieldType::is_array(class_name), "must be array"); 247 Klass* k = NULL; 248 FieldArrayInfo fd; 249 // dimension and object_key in FieldArrayInfo are assigned as a side-effect 250 // of this call 251 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL); 252 if (t == T_OBJECT) { 253 // naked oop "k" is OK here -- we assign back into it 254 k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(), 255 class_loader, 256 protection_domain, 257 CHECK_NULL); 258 if (k != NULL) { 259 k = k->array_klass(fd.dimension(), CHECK_NULL); 260 } 261 } else { 262 k = Universe::typeArrayKlassObj(t); 263 k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL); 264 } 265 return k; 266} 267 268 269// Must be called for any super-class or super-interface resolution 270// during class definition to allow class circularity checking 271// super-interface callers: 272// parse_interfaces - for defineClass & jvmtiRedefineClasses 273// super-class callers: 274// ClassFileParser - for defineClass & jvmtiRedefineClasses 275// load_shared_class - while loading a class from shared archive 276// resolve_instance_class_or_null: 277// via: handle_parallel_super_load 278// when resolving a class that has an existing placeholder with 279// a saved superclass [i.e. a defineClass is currently in progress] 280// if another thread is trying to resolve the class, it must do 281// super-class checks on its own thread to catch class circularity 282// This last call is critical in class circularity checking for cases 283// where classloading is delegated to different threads and the 284// classloader lock is released. 285// Take the case: Base->Super->Base 286// 1. If thread T1 tries to do a defineClass of class Base 287// resolve_super_or_fail creates placeholder: T1, Base (super Super) 288// 2. resolve_instance_class_or_null does not find SD or placeholder for Super 289// so it tries to load Super 290// 3. If we load the class internally, or user classloader uses same thread 291// loadClassFromxxx or defineClass via parseClassFile Super ... 292// 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base) 293// 3.3 resolve_instance_class_or_null Base, finds placeholder for Base 294// 3.4 calls resolve_super_or_fail Base 295// 3.5 finds T1,Base -> throws class circularity 296//OR 4. If T2 tries to resolve Super via defineClass Super ... 297// 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base) 298// 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super) 299// 4.3 calls resolve_super_or_fail Super in parallel on own thread T2 300// 4.4 finds T2, Super -> throws class circularity 301// Must be called, even if superclass is null, since this is 302// where the placeholder entry is created which claims this 303// thread is loading this class/classloader. 304Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name, 305 Symbol* class_name, 306 Handle class_loader, 307 Handle protection_domain, 308 bool is_superclass, 309 TRAPS) { 310 // Double-check, if child class is already loaded, just return super-class,interface 311 // Don't add a placedholder if already loaded, i.e. already in system dictionary 312 // Make sure there's a placeholder for the *child* before resolving. 313 // Used as a claim that this thread is currently loading superclass/classloader 314 // Used here for ClassCircularity checks and also for heap verification 315 // (every InstanceKlass in the heap needs to be in the system dictionary 316 // or have a placeholder). 317 // Must check ClassCircularity before checking if super class is already loaded 318 // 319 // We might not already have a placeholder if this child_name was 320 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass); 321 // the name of the class might not be known until the stream is actually 322 // parsed. 323 // Bugs 4643874, 4715493 324 // compute_hash can have a safepoint 325 326 ClassLoaderData* loader_data = class_loader_data(class_loader); 327 unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data); 328 int d_index = dictionary()->hash_to_index(d_hash); 329 unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data); 330 int p_index = placeholders()->hash_to_index(p_hash); 331 // can't throw error holding a lock 332 bool child_already_loaded = false; 333 bool throw_circularity_error = false; 334 { 335 MutexLocker mu(SystemDictionary_lock, THREAD); 336 Klass* childk = find_class(d_index, d_hash, child_name, loader_data); 337 Klass* quicksuperk; 338 // to support // loading: if child done loading, just return superclass 339 // if class_name, & class_loader don't match: 340 // if initial define, SD update will give LinkageError 341 // if redefine: compare_class_versions will give HIERARCHY_CHANGED 342 // so we don't throw an exception here. 343 // see: nsk redefclass014 & java.lang.instrument Instrument032 344 if ((childk != NULL ) && (is_superclass) && 345 ((quicksuperk = InstanceKlass::cast(childk)->super()) != NULL) && 346 347 ((quicksuperk->name() == class_name) && 348 (quicksuperk->class_loader() == class_loader()))) { 349 return quicksuperk; 350 } else { 351 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data); 352 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) { 353 throw_circularity_error = true; 354 } 355 } 356 if (!throw_circularity_error) { 357 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD); 358 } 359 } 360 if (throw_circularity_error) { 361 ResourceMark rm(THREAD); 362 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string()); 363 } 364 365// java.lang.Object should have been found above 366 assert(class_name != NULL, "null super class for resolving"); 367 // Resolve the super class or interface, check results on return 368 Klass* superk = SystemDictionary::resolve_or_null(class_name, 369 class_loader, 370 protection_domain, 371 THREAD); 372 373 KlassHandle superk_h(THREAD, superk); 374 375 // Clean up of placeholders moved so that each classloadAction registrar self-cleans up 376 // It is no longer necessary to keep the placeholder table alive until update_dictionary 377 // or error. GC used to walk the placeholder table as strong roots. 378 // The instanceKlass is kept alive because the class loader is on the stack, 379 // which keeps the loader_data alive, as well as all instanceKlasses in 380 // the loader_data. parseClassFile adds the instanceKlass to loader_data. 381 { 382 MutexLocker mu(SystemDictionary_lock, THREAD); 383 placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD); 384 SystemDictionary_lock->notify_all(); 385 } 386 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) { 387 // can null superk 388 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD)); 389 } 390 391 return superk_h(); 392} 393 394void SystemDictionary::validate_protection_domain(instanceKlassHandle klass, 395 Handle class_loader, 396 Handle protection_domain, 397 TRAPS) { 398 if(!has_checkPackageAccess()) return; 399 400 // Now we have to call back to java to check if the initating class has access 401 JavaValue result(T_VOID); 402 if (TraceProtectionDomainVerification) { 403 // Print out trace information 404 tty->print_cr("Checking package access"); 405 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr(); 406 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr(); 407 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr(); 408 } 409 410 KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass()); 411 JavaCalls::call_special(&result, 412 class_loader, 413 system_loader, 414 vmSymbols::checkPackageAccess_name(), 415 vmSymbols::class_protectiondomain_signature(), 416 Handle(THREAD, klass->java_mirror()), 417 protection_domain, 418 THREAD); 419 420 if (TraceProtectionDomainVerification) { 421 if (HAS_PENDING_EXCEPTION) { 422 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!"); 423 } else { 424 tty->print_cr(" -> granted"); 425 } 426 tty->cr(); 427 } 428 429 if (HAS_PENDING_EXCEPTION) return; 430 431 // If no exception has been thrown, we have validated the protection domain 432 // Insert the protection domain of the initiating class into the set. 433 { 434 // We recalculate the entry here -- we've called out to java since 435 // the last time it was calculated. 436 ClassLoaderData* loader_data = class_loader_data(class_loader); 437 438 Symbol* kn = klass->name(); 439 unsigned int d_hash = dictionary()->compute_hash(kn, loader_data); 440 int d_index = dictionary()->hash_to_index(d_hash); 441 442 MutexLocker mu(SystemDictionary_lock, THREAD); 443 { 444 // Note that we have an entry, and entries can be deleted only during GC, 445 // so we cannot allow GC to occur while we're holding this entry. 446 447 // We're using a No_Safepoint_Verifier to catch any place where we 448 // might potentially do a GC at all. 449 // Dictionary::do_unloading() asserts that classes in SD are only 450 // unloaded at a safepoint. Anonymous classes are not in SD. 451 No_Safepoint_Verifier nosafepoint; 452 dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data, 453 protection_domain, THREAD); 454 } 455 } 456} 457 458// We only get here if this thread finds that another thread 459// has already claimed the placeholder token for the current operation, 460// but that other thread either never owned or gave up the 461// object lock 462// Waits on SystemDictionary_lock to indicate placeholder table updated 463// On return, caller must recheck placeholder table state 464// 465// We only get here if 466// 1) custom classLoader, i.e. not bootstrap classloader 467// 2) UnsyncloadClass not set 468// 3) custom classLoader has broken the class loader objectLock 469// so another thread got here in parallel 470// 471// lockObject must be held. 472// Complicated dance due to lock ordering: 473// Must first release the classloader object lock to 474// allow initial definer to complete the class definition 475// and to avoid deadlock 476// Reclaim classloader lock object with same original recursion count 477// Must release SystemDictionary_lock after notify, since 478// class loader lock must be claimed before SystemDictionary_lock 479// to prevent deadlocks 480// 481// The notify allows applications that did an untimed wait() on 482// the classloader object lock to not hang. 483void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) { 484 assert_lock_strong(SystemDictionary_lock); 485 486 bool calledholdinglock 487 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject); 488 assert(calledholdinglock,"must hold lock for notify"); 489 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait"); 490 ObjectSynchronizer::notifyall(lockObject, THREAD); 491 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD); 492 SystemDictionary_lock->wait(); 493 SystemDictionary_lock->unlock(); 494 ObjectSynchronizer::reenter(lockObject, recursions, THREAD); 495 SystemDictionary_lock->lock(); 496} 497 498// If the class in is in the placeholder table, class loading is in progress 499// For cases where the application changes threads to load classes, it 500// is critical to ClassCircularity detection that we try loading 501// the superclass on the same thread internally, so we do parallel 502// super class loading here. 503// This also is critical in cases where the original thread gets stalled 504// even in non-circularity situations. 505// Note: must call resolve_super_or_fail even if null super - 506// to force placeholder entry creation for this class for circularity detection 507// Caller must check for pending exception 508// Returns non-null Klass* if other thread has completed load 509// and we are done, 510// If return null Klass* and no pending exception, the caller must load the class 511instanceKlassHandle SystemDictionary::handle_parallel_super_load( 512 Symbol* name, Symbol* superclassname, Handle class_loader, 513 Handle protection_domain, Handle lockObject, TRAPS) { 514 515 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 516 ClassLoaderData* loader_data = class_loader_data(class_loader); 517 unsigned int d_hash = dictionary()->compute_hash(name, loader_data); 518 int d_index = dictionary()->hash_to_index(d_hash); 519 unsigned int p_hash = placeholders()->compute_hash(name, loader_data); 520 int p_index = placeholders()->hash_to_index(p_hash); 521 522 // superk is not used, resolve_super called for circularity check only 523 // This code is reached in two situations. One if this thread 524 // is loading the same class twice (e.g. ClassCircularity, or 525 // java.lang.instrument). 526 // The second is if another thread started the resolve_super first 527 // and has not yet finished. 528 // In both cases the original caller will clean up the placeholder 529 // entry on error. 530 Klass* superk = SystemDictionary::resolve_super_or_fail(name, 531 superclassname, 532 class_loader, 533 protection_domain, 534 true, 535 CHECK_(nh)); 536 537 // parallelCapable class loaders do NOT wait for parallel superclass loads to complete 538 // Serial class loaders and bootstrap classloader do wait for superclass loads 539 if (!class_loader.is_null() && is_parallelCapable(class_loader)) { 540 MutexLocker mu(SystemDictionary_lock, THREAD); 541 // Check if classloading completed while we were loading superclass or waiting 542 Klass* check = find_class(d_index, d_hash, name, loader_data); 543 if (check != NULL) { 544 // Klass is already loaded, so just return it 545 return(instanceKlassHandle(THREAD, check)); 546 } else { 547 return nh; 548 } 549 } 550 551 // must loop to both handle other placeholder updates 552 // and spurious notifications 553 bool super_load_in_progress = true; 554 PlaceholderEntry* placeholder; 555 while (super_load_in_progress) { 556 MutexLocker mu(SystemDictionary_lock, THREAD); 557 // Check if classloading completed while we were loading superclass or waiting 558 Klass* check = find_class(d_index, d_hash, name, loader_data); 559 if (check != NULL) { 560 // Klass is already loaded, so just return it 561 return(instanceKlassHandle(THREAD, check)); 562 } else { 563 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data); 564 if (placeholder && placeholder->super_load_in_progress() ){ 565 // Before UnsyncloadClass: 566 // We only get here if the application has released the 567 // classloader lock when another thread was in the middle of loading a 568 // superclass/superinterface for this class, and now 569 // this thread is also trying to load this class. 570 // To minimize surprises, the first thread that started to 571 // load a class should be the one to complete the loading 572 // with the classfile it initially expected. 573 // This logic has the current thread wait once it has done 574 // all the superclass/superinterface loading it can, until 575 // the original thread completes the class loading or fails 576 // If it completes we will use the resulting InstanceKlass 577 // which we will find below in the systemDictionary. 578 // We also get here for parallel bootstrap classloader 579 if (class_loader.is_null()) { 580 SystemDictionary_lock->wait(); 581 } else { 582 double_lock_wait(lockObject, THREAD); 583 } 584 } else { 585 // If not in SD and not in PH, other thread's load must have failed 586 super_load_in_progress = false; 587 } 588 } 589 } 590 return (nh); 591} 592 593 594Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name, 595 Handle class_loader, 596 Handle protection_domain, 597 TRAPS) { 598 assert(name != NULL && !FieldType::is_array(name) && 599 !FieldType::is_obj(name), "invalid class name"); 600 601 Ticks class_load_start_time = Ticks::now(); 602 603 // UseNewReflection 604 // Fix for 4474172; see evaluation for more details 605 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader())); 606 ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL); 607 608 // Do lookup to see if class already exist and the protection domain 609 // has the right access 610 // This call uses find which checks protection domain already matches 611 // All subsequent calls use find_class, and set has_loaded_class so that 612 // before we return a result we call out to java to check for valid protection domain 613 // to allow returning the Klass* and add it to the pd_set if it is valid 614 unsigned int d_hash = dictionary()->compute_hash(name, loader_data); 615 int d_index = dictionary()->hash_to_index(d_hash); 616 Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data, 617 protection_domain, THREAD); 618 if (probe != NULL) return probe; 619 620 621 // Non-bootstrap class loaders will call out to class loader and 622 // define via jvm/jni_DefineClass which will acquire the 623 // class loader object lock to protect against multiple threads 624 // defining the class in parallel by accident. 625 // This lock must be acquired here so the waiter will find 626 // any successful result in the SystemDictionary and not attempt 627 // the define 628 // ParallelCapable Classloaders and the bootstrap classloader, 629 // or all classloaders with UnsyncloadClass do not acquire lock here 630 bool DoObjectLock = true; 631 if (is_parallelCapable(class_loader)) { 632 DoObjectLock = false; 633 } 634 635 unsigned int p_hash = placeholders()->compute_hash(name, loader_data); 636 int p_index = placeholders()->hash_to_index(p_hash); 637 638 // Class is not in SystemDictionary so we have to do loading. 639 // Make sure we are synchronized on the class loader before we proceed 640 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 641 check_loader_lock_contention(lockObject, THREAD); 642 ObjectLocker ol(lockObject, THREAD, DoObjectLock); 643 644 // Check again (after locking) if class already exist in SystemDictionary 645 bool class_has_been_loaded = false; 646 bool super_load_in_progress = false; 647 bool havesupername = false; 648 instanceKlassHandle k; 649 PlaceholderEntry* placeholder; 650 Symbol* superclassname = NULL; 651 652 { 653 MutexLocker mu(SystemDictionary_lock, THREAD); 654 Klass* check = find_class(d_index, d_hash, name, loader_data); 655 if (check != NULL) { 656 // Klass is already loaded, so just return it 657 class_has_been_loaded = true; 658 k = instanceKlassHandle(THREAD, check); 659 } else { 660 placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data); 661 if (placeholder && placeholder->super_load_in_progress()) { 662 super_load_in_progress = true; 663 if (placeholder->havesupername() == true) { 664 superclassname = placeholder->supername(); 665 havesupername = true; 666 } 667 } 668 } 669 } 670 671 // If the class is in the placeholder table, class loading is in progress 672 if (super_load_in_progress && havesupername==true) { 673 k = SystemDictionary::handle_parallel_super_load(name, superclassname, 674 class_loader, protection_domain, lockObject, THREAD); 675 if (HAS_PENDING_EXCEPTION) { 676 return NULL; 677 } 678 if (!k.is_null()) { 679 class_has_been_loaded = true; 680 } 681 } 682 683 bool throw_circularity_error = false; 684 if (!class_has_been_loaded) { 685 bool load_instance_added = false; 686 687 // add placeholder entry to record loading instance class 688 // Five cases: 689 // All cases need to prevent modifying bootclasssearchpath 690 // in parallel with a classload of same classname 691 // Redefineclasses uses existence of the placeholder for the duration 692 // of the class load to prevent concurrent redefinition of not completely 693 // defined classes. 694 // case 1. traditional classloaders that rely on the classloader object lock 695 // - no other need for LOAD_INSTANCE 696 // case 2. traditional classloaders that break the classloader object lock 697 // as a deadlock workaround. Detection of this case requires that 698 // this check is done while holding the classloader object lock, 699 // and that lock is still held when calling classloader's loadClass. 700 // For these classloaders, we ensure that the first requestor 701 // completes the load and other requestors wait for completion. 702 // case 3. UnsyncloadClass - don't use objectLocker 703 // With this flag, we allow parallel classloading of a 704 // class/classloader pair 705 // case4. Bootstrap classloader - don't own objectLocker 706 // This classloader supports parallelism at the classloader level, 707 // but only allows a single load of a class/classloader pair. 708 // No performance benefit and no deadlock issues. 709 // case 5. parallelCapable user level classloaders - without objectLocker 710 // Allow parallel classloading of a class/classloader pair 711 712 { 713 MutexLocker mu(SystemDictionary_lock, THREAD); 714 if (class_loader.is_null() || !is_parallelCapable(class_loader)) { 715 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data); 716 if (oldprobe) { 717 // only need check_seen_thread once, not on each loop 718 // 6341374 java/lang/Instrument with -Xcomp 719 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) { 720 throw_circularity_error = true; 721 } else { 722 // case 1: traditional: should never see load_in_progress. 723 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) { 724 725 // case 4: bootstrap classloader: prevent futile classloading, 726 // wait on first requestor 727 if (class_loader.is_null()) { 728 SystemDictionary_lock->wait(); 729 } else { 730 // case 2: traditional with broken classloader lock. wait on first 731 // requestor. 732 double_lock_wait(lockObject, THREAD); 733 } 734 // Check if classloading completed while we were waiting 735 Klass* check = find_class(d_index, d_hash, name, loader_data); 736 if (check != NULL) { 737 // Klass is already loaded, so just return it 738 k = instanceKlassHandle(THREAD, check); 739 class_has_been_loaded = true; 740 } 741 // check if other thread failed to load and cleaned up 742 oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data); 743 } 744 } 745 } 746 } 747 // All cases: add LOAD_INSTANCE holding SystemDictionary_lock 748 // case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try 749 // LOAD_INSTANCE in parallel 750 751 if (!throw_circularity_error && !class_has_been_loaded) { 752 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD); 753 load_instance_added = true; 754 // For class loaders that do not acquire the classloader object lock, 755 // if they did not catch another thread holding LOAD_INSTANCE, 756 // need a check analogous to the acquire ObjectLocker/find_class 757 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL 758 // one final check if the load has already completed 759 // class loaders holding the ObjectLock shouldn't find the class here 760 Klass* check = find_class(d_index, d_hash, name, loader_data); 761 if (check != NULL) { 762 // Klass is already loaded, so return it after checking/adding protection domain 763 k = instanceKlassHandle(THREAD, check); 764 class_has_been_loaded = true; 765 } 766 } 767 } 768 769 // must throw error outside of owning lock 770 if (throw_circularity_error) { 771 assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup"); 772 ResourceMark rm(THREAD); 773 THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string()); 774 } 775 776 if (!class_has_been_loaded) { 777 778 // Do actual loading 779 k = load_instance_class(name, class_loader, THREAD); 780 781 // For UnsyncloadClass only 782 // If they got a linkageError, check if a parallel class load succeeded. 783 // If it did, then for bytecode resolution the specification requires 784 // that we return the same result we did for the other thread, i.e. the 785 // successfully loaded InstanceKlass 786 // Should not get here for classloaders that support parallelism 787 // with the new cleaner mechanism, even with AllowParallelDefineClass 788 // Bootstrap goes through here to allow for an extra guarantee check 789 if (UnsyncloadClass || (class_loader.is_null())) { 790 if (k.is_null() && HAS_PENDING_EXCEPTION 791 && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) { 792 MutexLocker mu(SystemDictionary_lock, THREAD); 793 Klass* check = find_class(d_index, d_hash, name, loader_data); 794 if (check != NULL) { 795 // Klass is already loaded, so just use it 796 k = instanceKlassHandle(THREAD, check); 797 CLEAR_PENDING_EXCEPTION; 798 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?"); 799 } 800 } 801 } 802 803 // If everything was OK (no exceptions, no null return value), and 804 // class_loader is NOT the defining loader, do a little more bookkeeping. 805 if (!HAS_PENDING_EXCEPTION && !k.is_null() && 806 k->class_loader() != class_loader()) { 807 808 check_constraints(d_index, d_hash, k, class_loader, false, THREAD); 809 810 // Need to check for a PENDING_EXCEPTION again; check_constraints 811 // can throw and doesn't use the CHECK macro. 812 if (!HAS_PENDING_EXCEPTION) { 813 { // Grabbing the Compile_lock prevents systemDictionary updates 814 // during compilations. 815 MutexLocker mu(Compile_lock, THREAD); 816 update_dictionary(d_index, d_hash, p_index, p_hash, 817 k, class_loader, THREAD); 818 } 819 820 if (JvmtiExport::should_post_class_load()) { 821 Thread *thread = THREAD; 822 assert(thread->is_Java_thread(), "thread->is_Java_thread()"); 823 JvmtiExport::post_class_load((JavaThread *) thread, k()); 824 } 825 } 826 } 827 } // load_instance_class loop 828 829 if (HAS_PENDING_EXCEPTION) { 830 // An exception, such as OOM could have happened at various places inside 831 // load_instance_class. We might have partially initialized a shared class 832 // and need to clean it up. 833 if (class_loader.is_null()) { 834 // In some cases k may be null. Let's find the shared class again. 835 instanceKlassHandle ik(THREAD, find_shared_class(name)); 836 if (ik.not_null()) { 837 if (ik->class_loader_data() == NULL) { 838 // We didn't go as far as Klass::restore_unshareable_info(), 839 // so nothing to clean up. 840 } else { 841 Klass *kk; 842 { 843 MutexLocker mu(SystemDictionary_lock, THREAD); 844 kk = find_class(d_index, d_hash, name, ik->class_loader_data()); 845 } 846 if (kk != NULL) { 847 // No clean up is needed if the shared class has been entered 848 // into system dictionary, as load_shared_class() won't be called 849 // again. 850 } else { 851 // This must be done outside of the SystemDictionary_lock to 852 // avoid deadlock. 853 // 854 // Note that Klass::restore_unshareable_info (called via 855 // load_instance_class above) is also called outside 856 // of SystemDictionary_lock. Other threads are blocked from 857 // loading this class because they are waiting on the 858 // SystemDictionary_lock until this thread removes 859 // the placeholder below. 860 // 861 // This need to be re-thought when parallel-capable non-boot 862 // classloaders are supported by CDS (today they're not). 863 clean_up_shared_class(ik, class_loader, THREAD); 864 } 865 } 866 } 867 } 868 } 869 870 if (load_instance_added == true) { 871 // clean up placeholder entries for LOAD_INSTANCE success or error 872 // This brackets the SystemDictionary updates for both defining 873 // and initiating loaders 874 MutexLocker mu(SystemDictionary_lock, THREAD); 875 placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD); 876 SystemDictionary_lock->notify_all(); 877 } 878 } 879 880 if (HAS_PENDING_EXCEPTION || k.is_null()) { 881 return NULL; 882 } 883 884 post_class_load_event(class_load_start_time, k, class_loader); 885 886#ifdef ASSERT 887 { 888 ClassLoaderData* loader_data = k->class_loader_data(); 889 MutexLocker mu(SystemDictionary_lock, THREAD); 890 Klass* kk = find_class(name, loader_data); 891 assert(kk == k(), "should be present in dictionary"); 892 } 893#endif 894 895 // return if the protection domain in NULL 896 if (protection_domain() == NULL) return k(); 897 898 // Check the protection domain has the right access 899 { 900 MutexLocker mu(SystemDictionary_lock, THREAD); 901 // Note that we have an entry, and entries can be deleted only during GC, 902 // so we cannot allow GC to occur while we're holding this entry. 903 // We're using a No_Safepoint_Verifier to catch any place where we 904 // might potentially do a GC at all. 905 // Dictionary::do_unloading() asserts that classes in SD are only 906 // unloaded at a safepoint. Anonymous classes are not in SD. 907 No_Safepoint_Verifier nosafepoint; 908 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name, 909 loader_data, 910 protection_domain)) { 911 return k(); 912 } 913 } 914 915 // Verify protection domain. If it fails an exception is thrown 916 validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL); 917 918 return k(); 919} 920 921 922// This routine does not lock the system dictionary. 923// 924// Since readers don't hold a lock, we must make sure that system 925// dictionary entries are only removed at a safepoint (when only one 926// thread is running), and are added to in a safe way (all links must 927// be updated in an MT-safe manner). 928// 929// Callers should be aware that an entry could be added just after 930// _dictionary->bucket(index) is read here, so the caller will not see 931// the new entry. 932 933Klass* SystemDictionary::find(Symbol* class_name, 934 Handle class_loader, 935 Handle protection_domain, 936 TRAPS) { 937 938 // UseNewReflection 939 // The result of this call should be consistent with the result 940 // of the call to resolve_instance_class_or_null(). 941 // See evaluation 6790209 and 4474172 for more details. 942 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader())); 943 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader()); 944 945 if (loader_data == NULL) { 946 // If the ClassLoaderData has not been setup, 947 // then the class loader has no entries in the dictionary. 948 return NULL; 949 } 950 951 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data); 952 int d_index = dictionary()->hash_to_index(d_hash); 953 954 { 955 // Note that we have an entry, and entries can be deleted only during GC, 956 // so we cannot allow GC to occur while we're holding this entry. 957 // We're using a No_Safepoint_Verifier to catch any place where we 958 // might potentially do a GC at all. 959 // Dictionary::do_unloading() asserts that classes in SD are only 960 // unloaded at a safepoint. Anonymous classes are not in SD. 961 No_Safepoint_Verifier nosafepoint; 962 return dictionary()->find(d_index, d_hash, class_name, loader_data, 963 protection_domain, THREAD); 964 } 965} 966 967 968// Look for a loaded instance or array klass by name. Do not do any loading. 969// return NULL in case of error. 970Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name, 971 Handle class_loader, 972 Handle protection_domain, 973 TRAPS) { 974 Klass* k = NULL; 975 assert(class_name != NULL, "class name must be non NULL"); 976 977 if (FieldType::is_array(class_name)) { 978 // The name refers to an array. Parse the name. 979 // dimension and object_key in FieldArrayInfo are assigned as a 980 // side-effect of this call 981 FieldArrayInfo fd; 982 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL)); 983 if (t != T_OBJECT) { 984 k = Universe::typeArrayKlassObj(t); 985 } else { 986 k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD); 987 } 988 if (k != NULL) { 989 k = k->array_klass_or_null(fd.dimension()); 990 } 991 } else { 992 k = find(class_name, class_loader, protection_domain, THREAD); 993 } 994 return k; 995} 996 997// Note: this method is much like resolve_from_stream, but 998// updates no supplemental data structures. 999// TODO consolidate the two methods with a helper routine? 1000Klass* SystemDictionary::parse_stream(Symbol* class_name, 1001 Handle class_loader, 1002 Handle protection_domain, 1003 ClassFileStream* st, 1004 KlassHandle host_klass, 1005 GrowableArray<Handle>* cp_patches, 1006 TRAPS) { 1007 TempNewSymbol parsed_name = NULL; 1008 1009 Ticks class_load_start_time = Ticks::now(); 1010 1011 ClassLoaderData* loader_data; 1012 if (host_klass.not_null()) { 1013 // Create a new CLD for anonymous class, that uses the same class loader 1014 // as the host_klass 1015 assert(EnableInvokeDynamic, ""); 1016 guarantee(host_klass->class_loader() == class_loader(), "should be the same"); 1017 loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL); 1018 loader_data->record_dependency(host_klass(), CHECK_NULL); 1019 } else { 1020 loader_data = ClassLoaderData::class_loader_data(class_loader()); 1021 } 1022 1023 // Parse the stream. Note that we do this even though this klass might 1024 // already be present in the SystemDictionary, otherwise we would not 1025 // throw potential ClassFormatErrors. 1026 // 1027 // Note: "name" is updated. 1028 1029 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name, 1030 loader_data, 1031 protection_domain, 1032 host_klass, 1033 cp_patches, 1034 parsed_name, 1035 true, 1036 THREAD); 1037 1038 1039 if (host_klass.not_null() && k.not_null()) { 1040 assert(EnableInvokeDynamic, ""); 1041 k->set_host_klass(host_klass()); 1042 // If it's anonymous, initialize it now, since nobody else will. 1043 1044 { 1045 MutexLocker mu_r(Compile_lock, THREAD); 1046 1047 // Add to class hierarchy, initialize vtables, and do possible 1048 // deoptimizations. 1049 add_to_hierarchy(k, CHECK_NULL); // No exception, but can block 1050 1051 // But, do not add to system dictionary. 1052 1053 // compiled code dependencies need to be validated anyway 1054 notice_modification(); 1055 } 1056 1057 // Rewrite and patch constant pool here. 1058 k->link_class(CHECK_NULL); 1059 if (cp_patches != NULL) { 1060 k->constants()->patch_resolved_references(cp_patches); 1061 } 1062 k->eager_initialize(CHECK_NULL); 1063 1064 // notify jvmti 1065 if (JvmtiExport::should_post_class_load()) { 1066 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()"); 1067 JvmtiExport::post_class_load((JavaThread *) THREAD, k()); 1068 } 1069 1070 post_class_load_event(class_load_start_time, k, class_loader); 1071 } 1072 assert(host_klass.not_null() || cp_patches == NULL, 1073 "cp_patches only found with host_klass"); 1074 1075 return k(); 1076} 1077 1078// Add a klass to the system from a stream (called by jni_DefineClass and 1079// JVM_DefineClass). 1080// Note: class_name can be NULL. In that case we do not know the name of 1081// the class until we have parsed the stream. 1082 1083Klass* SystemDictionary::resolve_from_stream(Symbol* class_name, 1084 Handle class_loader, 1085 Handle protection_domain, 1086 ClassFileStream* st, 1087 bool verify, 1088 TRAPS) { 1089 1090 // Classloaders that support parallelism, e.g. bootstrap classloader, 1091 // or all classloaders with UnsyncloadClass do not acquire lock here 1092 bool DoObjectLock = true; 1093 if (is_parallelCapable(class_loader)) { 1094 DoObjectLock = false; 1095 } 1096 1097 ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL); 1098 1099 // Make sure we are synchronized on the class loader before we proceed 1100 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 1101 check_loader_lock_contention(lockObject, THREAD); 1102 ObjectLocker ol(lockObject, THREAD, DoObjectLock); 1103 1104 TempNewSymbol parsed_name = NULL; 1105 1106 // Parse the stream. Note that we do this even though this klass might 1107 // already be present in the SystemDictionary, otherwise we would not 1108 // throw potential ClassFormatErrors. 1109 // 1110 // Note: "name" is updated. 1111 1112 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name, 1113 loader_data, 1114 protection_domain, 1115 parsed_name, 1116 verify, 1117 THREAD); 1118 1119 const char* pkg = "java/"; 1120 if (!HAS_PENDING_EXCEPTION && 1121 !class_loader.is_null() && 1122 parsed_name != NULL && 1123 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) { 1124 // It is illegal to define classes in the "java." package from 1125 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader 1126 ResourceMark rm(THREAD); 1127 char* name = parsed_name->as_C_string(); 1128 char* index = strrchr(name, '/'); 1129 *index = '\0'; // chop to just the package name 1130 while ((index = strchr(name, '/')) != NULL) { 1131 *index = '.'; // replace '/' with '.' in package name 1132 } 1133 const char* fmt = "Prohibited package name: %s"; 1134 size_t len = strlen(fmt) + strlen(name); 1135 char* message = NEW_RESOURCE_ARRAY(char, len); 1136 jio_snprintf(message, len, fmt, name); 1137 Exceptions::_throw_msg(THREAD_AND_LOCATION, 1138 vmSymbols::java_lang_SecurityException(), message); 1139 } 1140 1141 if (!HAS_PENDING_EXCEPTION) { 1142 assert(parsed_name != NULL, "Sanity"); 1143 assert(class_name == NULL || class_name == parsed_name, "name mismatch"); 1144 // Verification prevents us from creating names with dots in them, this 1145 // asserts that that's the case. 1146 assert(is_internal_format(parsed_name), 1147 "external class name format used internally"); 1148 1149 // Add class just loaded 1150 // If a class loader supports parallel classloading handle parallel define requests 1151 // find_or_define_instance_class may return a different InstanceKlass 1152 if (is_parallelCapable(class_loader)) { 1153 k = find_or_define_instance_class(class_name, class_loader, k, THREAD); 1154 } else { 1155 define_instance_class(k, THREAD); 1156 } 1157 } 1158 1159 // Make sure we have an entry in the SystemDictionary on success 1160 debug_only( { 1161 if (!HAS_PENDING_EXCEPTION) { 1162 assert(parsed_name != NULL, "parsed_name is still null?"); 1163 Symbol* h_name = k->name(); 1164 ClassLoaderData *defining_loader_data = k->class_loader_data(); 1165 1166 MutexLocker mu(SystemDictionary_lock, THREAD); 1167 1168 Klass* check = find_class(parsed_name, loader_data); 1169 assert(check == k(), "should be present in the dictionary"); 1170 1171 Klass* check2 = find_class(h_name, defining_loader_data); 1172 assert(check == check2, "name inconsistancy in SystemDictionary"); 1173 } 1174 } ); 1175 1176 return k(); 1177} 1178 1179 1180void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 1181 int number_of_entries) { 1182 assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>), 1183 "bad shared dictionary size."); 1184 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries); 1185} 1186 1187 1188// If there is a shared dictionary, then find the entry for the 1189// given shared system class, if any. 1190 1191Klass* SystemDictionary::find_shared_class(Symbol* class_name) { 1192 if (shared_dictionary() != NULL) { 1193 unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL); 1194 int d_index = shared_dictionary()->hash_to_index(d_hash); 1195 1196 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name); 1197 } else { 1198 return NULL; 1199 } 1200} 1201 1202 1203// Load a class from the shared spaces (found through the shared system 1204// dictionary). Force the superclass and all interfaces to be loaded. 1205// Update the class definition to include sibling classes and no 1206// subclasses (yet). [Classes in the shared space are not part of the 1207// object hierarchy until loaded.] 1208 1209instanceKlassHandle SystemDictionary::load_shared_class( 1210 Symbol* class_name, Handle class_loader, TRAPS) { 1211 instanceKlassHandle ik (THREAD, find_shared_class(class_name)); 1212 return load_shared_class(ik, class_loader, THREAD); 1213} 1214 1215instanceKlassHandle SystemDictionary::load_shared_class( 1216 instanceKlassHandle ik, Handle class_loader, TRAPS) { 1217 assert(class_loader.is_null(), "non-null classloader for shared class?"); 1218 if (ik.not_null()) { 1219 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 1220 Symbol* class_name = ik->name(); 1221 1222 // Found the class, now load the superclass and interfaces. If they 1223 // are shared, add them to the main system dictionary and reset 1224 // their hierarchy references (supers, subs, and interfaces). 1225 1226 if (ik->super() != NULL) { 1227 Symbol* cn = ik->super()->name(); 1228 resolve_super_or_fail(class_name, cn, 1229 class_loader, Handle(), true, CHECK_(nh)); 1230 } 1231 1232 Array<Klass*>* interfaces = ik->local_interfaces(); 1233 int num_interfaces = interfaces->length(); 1234 for (int index = 0; index < num_interfaces; index++) { 1235 Klass* k = interfaces->at(index); 1236 1237 // Note: can not use InstanceKlass::cast here because 1238 // interfaces' InstanceKlass's C++ vtbls haven't been 1239 // reinitialized yet (they will be once the interface classes 1240 // are loaded) 1241 Symbol* name = k->name(); 1242 resolve_super_or_fail(class_name, name, class_loader, Handle(), false, CHECK_(nh)); 1243 } 1244 1245 // Adjust methods to recover missing data. They need addresses for 1246 // interpreter entry points and their default native method address 1247 // must be reset. 1248 1249 // Updating methods must be done under a lock so multiple 1250 // threads don't update these in parallel 1251 // Shared classes are all currently loaded by the bootstrap 1252 // classloader, so this will never cause a deadlock on 1253 // a custom class loader lock. 1254 1255 { 1256 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 1257 check_loader_lock_contention(lockObject, THREAD); 1258 ObjectLocker ol(lockObject, THREAD, true); 1259 ik->restore_unshareable_info(CHECK_(nh)); 1260 } 1261 1262 if (TraceClassLoading) { 1263 ResourceMark rm; 1264 tty->print("[Loaded %s", ik->external_name()); 1265 tty->print(" from shared objects file"); 1266 tty->print_cr("]"); 1267 } 1268 // notify a class loaded from shared object 1269 ClassLoadingService::notify_class_loaded(InstanceKlass::cast(ik()), 1270 true /* shared class */); 1271 } 1272 return ik; 1273} 1274 1275void SystemDictionary::clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS) { 1276 // Updating methods must be done under a lock so multiple 1277 // threads don't update these in parallel 1278 // Shared classes are all currently loaded by the bootstrap 1279 // classloader, so this will never cause a deadlock on 1280 // a custom class loader lock. 1281 { 1282 Handle lockObject = compute_loader_lock_object(class_loader, THREAD); 1283 check_loader_lock_contention(lockObject, THREAD); 1284 ObjectLocker ol(lockObject, THREAD, true); 1285 ik->remove_unshareable_info(); 1286 } 1287} 1288 1289instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) { 1290 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 1291 if (class_loader.is_null()) { 1292 1293 // Search the shared system dictionary for classes preloaded into the 1294 // shared spaces. 1295 instanceKlassHandle k; 1296 { 1297 PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time()); 1298 k = load_shared_class(class_name, class_loader, THREAD); 1299 } 1300 1301 if (k.is_null()) { 1302 // Use VM class loader 1303 PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time()); 1304 k = ClassLoader::load_classfile(class_name, CHECK_(nh)); 1305 } 1306 1307 // find_or_define_instance_class may return a different InstanceKlass 1308 if (!k.is_null()) { 1309 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh)); 1310 } 1311 return k; 1312 } else { 1313 // Use user specified class loader to load class. Call loadClass operation on class_loader. 1314 ResourceMark rm(THREAD); 1315 1316 assert(THREAD->is_Java_thread(), "must be a JavaThread"); 1317 JavaThread* jt = (JavaThread*) THREAD; 1318 1319 PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(), 1320 ClassLoader::perf_app_classload_selftime(), 1321 ClassLoader::perf_app_classload_count(), 1322 jt->get_thread_stat()->perf_recursion_counts_addr(), 1323 jt->get_thread_stat()->perf_timers_addr(), 1324 PerfClassTraceTime::CLASS_LOAD); 1325 1326 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh)); 1327 // Translate to external class name format, i.e., convert '/' chars to '.' 1328 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh)); 1329 1330 JavaValue result(T_OBJECT); 1331 1332 KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass()); 1333 1334 // Call public unsynchronized loadClass(String) directly for all class loaders 1335 // for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will 1336 // acquire a class-name based lock rather than the class loader object lock. 1337 // JDK < 7 already acquire the class loader lock in loadClass(String, boolean), 1338 // so the call to loadClassInternal() was not required. 1339 // 1340 // UnsyncloadClass flag means both call loadClass(String) and do 1341 // not acquire the class loader lock even for class loaders that are 1342 // not parallelCapable. This was a risky transitional 1343 // flag for diagnostic purposes only. It is risky to call 1344 // custom class loaders without synchronization. 1345 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of 1346 // findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field. 1347 // Do NOT assume this will be supported in future releases. 1348 // 1349 // Added MustCallLoadClassInternal in case we discover in the field 1350 // a customer that counts on this call 1351 if (MustCallLoadClassInternal && has_loadClassInternal()) { 1352 JavaCalls::call_special(&result, 1353 class_loader, 1354 spec_klass, 1355 vmSymbols::loadClassInternal_name(), 1356 vmSymbols::string_class_signature(), 1357 string, 1358 CHECK_(nh)); 1359 } else { 1360 JavaCalls::call_virtual(&result, 1361 class_loader, 1362 spec_klass, 1363 vmSymbols::loadClass_name(), 1364 vmSymbols::string_class_signature(), 1365 string, 1366 CHECK_(nh)); 1367 } 1368 1369 assert(result.get_type() == T_OBJECT, "just checking"); 1370 oop obj = (oop) result.get_jobject(); 1371 1372 // Primitive classes return null since forName() can not be 1373 // used to obtain any of the Class objects representing primitives or void 1374 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) { 1375 instanceKlassHandle k = 1376 instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj)); 1377 // For user defined Java class loaders, check that the name returned is 1378 // the same as that requested. This check is done for the bootstrap 1379 // loader when parsing the class file. 1380 if (class_name == k->name()) { 1381 return k; 1382 } 1383 } 1384 // Class is not found or has the wrong name, return NULL 1385 return nh; 1386 } 1387} 1388 1389void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) { 1390 1391 ClassLoaderData* loader_data = k->class_loader_data(); 1392 Handle class_loader_h(THREAD, loader_data->class_loader()); 1393 1394 for (uintx it = 0; it < GCExpandToAllocateDelayMillis; it++){} 1395 1396 // for bootstrap and other parallel classloaders don't acquire lock, 1397 // use placeholder token 1398 // If a parallelCapable class loader calls define_instance_class instead of 1399 // find_or_define_instance_class to get here, we have a timing 1400 // hole with systemDictionary updates and check_constraints 1401 if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) { 1402 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, 1403 compute_loader_lock_object(class_loader_h, THREAD)), 1404 "define called without lock"); 1405 } 1406 1407 // Check class-loading constraints. Throw exception if violation is detected. 1408 // Grabs and releases SystemDictionary_lock 1409 // The check_constraints/find_class call and update_dictionary sequence 1410 // must be "atomic" for a specific class/classloader pair so we never 1411 // define two different instanceKlasses for that class/classloader pair. 1412 // Existing classloaders will call define_instance_class with the 1413 // classloader lock held 1414 // Parallel classloaders will call find_or_define_instance_class 1415 // which will require a token to perform the define class 1416 Symbol* name_h = k->name(); 1417 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data); 1418 int d_index = dictionary()->hash_to_index(d_hash); 1419 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK); 1420 1421 // Register class just loaded with class loader (placed in Vector) 1422 // Note we do this before updating the dictionary, as this can 1423 // fail with an OutOfMemoryError (if it does, we will *not* put this 1424 // class in the dictionary and will not update the class hierarchy). 1425 // JVMTI FollowReferences needs to find the classes this way. 1426 if (k->class_loader() != NULL) { 1427 methodHandle m(THREAD, Universe::loader_addClass_method()); 1428 JavaValue result(T_VOID); 1429 JavaCallArguments args(class_loader_h); 1430 args.push_oop(Handle(THREAD, k->java_mirror())); 1431 JavaCalls::call(&result, m, &args, CHECK); 1432 } 1433 1434 // Add the new class. We need recompile lock during update of CHA. 1435 { 1436 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data); 1437 int p_index = placeholders()->hash_to_index(p_hash); 1438 1439 MutexLocker mu_r(Compile_lock, THREAD); 1440 1441 // Add to class hierarchy, initialize vtables, and do possible 1442 // deoptimizations. 1443 add_to_hierarchy(k, CHECK); // No exception, but can block 1444 1445 // Add to systemDictionary - so other classes can see it. 1446 // Grabs and releases SystemDictionary_lock 1447 update_dictionary(d_index, d_hash, p_index, p_hash, 1448 k, class_loader_h, THREAD); 1449 } 1450 k->eager_initialize(THREAD); 1451 1452 // notify jvmti 1453 if (JvmtiExport::should_post_class_load()) { 1454 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()"); 1455 JvmtiExport::post_class_load((JavaThread *) THREAD, k()); 1456 1457 } 1458 1459} 1460 1461// Support parallel classloading 1462// All parallel class loaders, including bootstrap classloader 1463// lock a placeholder entry for this class/class_loader pair 1464// to allow parallel defines of different classes for this class loader 1465// With AllowParallelDefine flag==true, in case they do not synchronize around 1466// FindLoadedClass/DefineClass, calls, we check for parallel 1467// loading for them, wait if a defineClass is in progress 1468// and return the initial requestor's results 1469// This flag does not apply to the bootstrap classloader. 1470// With AllowParallelDefine flag==false, call through to define_instance_class 1471// which will throw LinkageError: duplicate class definition. 1472// False is the requested default. 1473// For better performance, the class loaders should synchronize 1474// findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they 1475// potentially waste time reading and parsing the bytestream. 1476// Note: VM callers should ensure consistency of k/class_name,class_loader 1477instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) { 1478 1479 instanceKlassHandle nh = instanceKlassHandle(); // null Handle 1480 Symbol* name_h = k->name(); // passed in class_name may be null 1481 ClassLoaderData* loader_data = class_loader_data(class_loader); 1482 1483 unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data); 1484 int d_index = dictionary()->hash_to_index(d_hash); 1485 1486// Hold SD lock around find_class and placeholder creation for DEFINE_CLASS 1487 unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data); 1488 int p_index = placeholders()->hash_to_index(p_hash); 1489 PlaceholderEntry* probe; 1490 1491 { 1492 MutexLocker mu(SystemDictionary_lock, THREAD); 1493 // First check if class already defined 1494 if (UnsyncloadClass || (is_parallelDefine(class_loader))) { 1495 Klass* check = find_class(d_index, d_hash, name_h, loader_data); 1496 if (check != NULL) { 1497 return(instanceKlassHandle(THREAD, check)); 1498 } 1499 } 1500 1501 // Acquire define token for this class/classloader 1502 probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD); 1503 // Wait if another thread defining in parallel 1504 // All threads wait - even those that will throw duplicate class: otherwise 1505 // caller is surprised by LinkageError: duplicate, but findLoadedClass fails 1506 // if other thread has not finished updating dictionary 1507 while (probe->definer() != NULL) { 1508 SystemDictionary_lock->wait(); 1509 } 1510 // Only special cases allow parallel defines and can use other thread's results 1511 // Other cases fall through, and may run into duplicate defines 1512 // caught by finding an entry in the SystemDictionary 1513 if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) { 1514 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD); 1515 SystemDictionary_lock->notify_all(); 1516#ifdef ASSERT 1517 Klass* check = find_class(d_index, d_hash, name_h, loader_data); 1518 assert(check != NULL, "definer missed recording success"); 1519#endif 1520 return(instanceKlassHandle(THREAD, probe->instance_klass())); 1521 } else { 1522 // This thread will define the class (even if earlier thread tried and had an error) 1523 probe->set_definer(THREAD); 1524 } 1525 } 1526 1527 define_instance_class(k, THREAD); 1528 1529 Handle linkage_exception = Handle(); // null handle 1530 1531 // definer must notify any waiting threads 1532 { 1533 MutexLocker mu(SystemDictionary_lock, THREAD); 1534 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data); 1535 assert(probe != NULL, "DEFINE_CLASS placeholder lost?"); 1536 if (probe != NULL) { 1537 if (HAS_PENDING_EXCEPTION) { 1538 linkage_exception = Handle(THREAD,PENDING_EXCEPTION); 1539 CLEAR_PENDING_EXCEPTION; 1540 } else { 1541 probe->set_instance_klass(k()); 1542 } 1543 probe->set_definer(NULL); 1544 placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD); 1545 SystemDictionary_lock->notify_all(); 1546 } 1547 } 1548 1549 // Can't throw exception while holding lock due to rank ordering 1550 if (linkage_exception() != NULL) { 1551 THROW_OOP_(linkage_exception(), nh); // throws exception and returns 1552 } 1553 1554 return k; 1555} 1556Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) { 1557 // If class_loader is NULL we synchronize on _system_loader_lock_obj 1558 if (class_loader.is_null()) { 1559 return Handle(THREAD, _system_loader_lock_obj); 1560 } else { 1561 return class_loader; 1562 } 1563} 1564 1565// This method is added to check how often we have to wait to grab loader 1566// lock. The results are being recorded in the performance counters defined in 1567// ClassLoader::_sync_systemLoaderLockContentionRate and 1568// ClassLoader::_sync_nonSystemLoaderLockConteionRate. 1569void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) { 1570 if (!UsePerfData) { 1571 return; 1572 } 1573 1574 assert(!loader_lock.is_null(), "NULL lock object"); 1575 1576 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock) 1577 == ObjectSynchronizer::owner_other) { 1578 // contention will likely happen, so increment the corresponding 1579 // contention counter. 1580 if (loader_lock() == _system_loader_lock_obj) { 1581 ClassLoader::sync_systemLoaderLockContentionRate()->inc(); 1582 } else { 1583 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc(); 1584 } 1585 } 1586} 1587 1588// ---------------------------------------------------------------------------- 1589// Lookup 1590 1591Klass* SystemDictionary::find_class(int index, unsigned int hash, 1592 Symbol* class_name, 1593 ClassLoaderData* loader_data) { 1594 assert_locked_or_safepoint(SystemDictionary_lock); 1595 assert (index == dictionary()->index_for(class_name, loader_data), 1596 "incorrect index?"); 1597 1598 Klass* k = dictionary()->find_class(index, hash, class_name, loader_data); 1599 return k; 1600} 1601 1602 1603// Basic find on classes in the midst of being loaded 1604Symbol* SystemDictionary::find_placeholder(Symbol* class_name, 1605 ClassLoaderData* loader_data) { 1606 assert_locked_or_safepoint(SystemDictionary_lock); 1607 unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data); 1608 int p_index = placeholders()->hash_to_index(p_hash); 1609 return placeholders()->find_entry(p_index, p_hash, class_name, loader_data); 1610} 1611 1612 1613// Used for assertions and verification only 1614Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) { 1615 #ifndef ASSERT 1616 guarantee(VerifyBeforeGC || 1617 VerifyDuringGC || 1618 VerifyBeforeExit || 1619 VerifyDuringStartup || 1620 VerifyAfterGC, "too expensive"); 1621 #endif 1622 assert_locked_or_safepoint(SystemDictionary_lock); 1623 1624 // First look in the loaded class array 1625 unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data); 1626 int d_index = dictionary()->hash_to_index(d_hash); 1627 return find_class(d_index, d_hash, class_name, loader_data); 1628} 1629 1630 1631// Get the next class in the diictionary. 1632Klass* SystemDictionary::try_get_next_class() { 1633 return dictionary()->try_get_next_class(); 1634} 1635 1636 1637// ---------------------------------------------------------------------------- 1638// Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock 1639// is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in 1640// before a new class is used. 1641 1642void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) { 1643 assert(k.not_null(), "just checking"); 1644 assert_locked_or_safepoint(Compile_lock); 1645 1646 // Link into hierachy. Make sure the vtables are initialized before linking into 1647 k->append_to_sibling_list(); // add to superklass/sibling list 1648 k->process_interfaces(THREAD); // handle all "implements" declarations 1649 k->set_init_state(InstanceKlass::loaded); 1650 // Now flush all code that depended on old class hierarchy. 1651 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97) 1652 // Also, first reinitialize vtable because it may have gotten out of synch 1653 // while the new class wasn't connected to the class hierarchy. 1654 Universe::flush_dependents_on(k); 1655} 1656 1657 1658// ---------------------------------------------------------------------------- 1659// GC support 1660 1661// Following roots during mark-sweep is separated in two phases. 1662// 1663// The first phase follows preloaded classes and all other system 1664// classes, since these will never get unloaded anyway. 1665// 1666// The second phase removes (unloads) unreachable classes from the 1667// system dictionary and follows the remaining classes' contents. 1668 1669void SystemDictionary::always_strong_oops_do(OopClosure* blk) { 1670 blk->do_oop(&_java_system_loader); 1671 blk->do_oop(&_system_loader_lock_obj); 1672 1673 dictionary()->always_strong_oops_do(blk); 1674 1675 // Visit extra methods 1676 invoke_method_table()->oops_do(blk); 1677} 1678 1679void SystemDictionary::always_strong_classes_do(KlassClosure* closure) { 1680 // Follow all system classes and temporary placeholders in dictionary 1681 dictionary()->always_strong_classes_do(closure); 1682 1683 // Placeholders. These represent classes we're actively loading. 1684 placeholders()->classes_do(closure); 1685} 1686 1687// Calculate a "good" systemdictionary size based 1688// on predicted or current loaded classes count 1689int SystemDictionary::calculate_systemdictionary_size(int classcount) { 1690 int newsize = _old_default_sdsize; 1691 if ((classcount > 0) && !DumpSharedSpaces) { 1692 int desiredsize = classcount/_average_depth_goal; 1693 for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1; 1694 newsize = _primelist[++_sdgeneration]) { 1695 if (desiredsize <= newsize) { 1696 break; 1697 } 1698 } 1699 } 1700 return newsize; 1701} 1702 1703#ifdef ASSERT 1704class VerifySDReachableAndLiveClosure : public OopClosure { 1705private: 1706 BoolObjectClosure* _is_alive; 1707 1708 template <class T> void do_oop_work(T* p) { 1709 oop obj = oopDesc::load_decode_heap_oop(p); 1710 guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live"); 1711 } 1712 1713public: 1714 VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { } 1715 1716 virtual void do_oop(oop* p) { do_oop_work(p); } 1717 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 1718}; 1719#endif 1720 1721// Assumes classes in the SystemDictionary are only unloaded at a safepoint 1722// Note: anonymous classes are not in the SD. 1723bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) { 1724 // First, mark for unload all ClassLoaderData referencing a dead class loader. 1725 bool has_dead_loaders = ClassLoaderDataGraph::do_unloading(is_alive); 1726 bool unloading_occurred = false; 1727 if (has_dead_loaders) { 1728 unloading_occurred = dictionary()->do_unloading(); 1729 constraints()->purge_loader_constraints(); 1730 resolution_errors()->purge_resolution_errors(); 1731 } 1732 // Oops referenced by the system dictionary may get unreachable independently 1733 // of the class loader (eg. cached protection domain oops). So we need to 1734 // explicitly unlink them here instead of in Dictionary::do_unloading. 1735 dictionary()->unlink(is_alive); 1736#ifdef ASSERT 1737 VerifySDReachableAndLiveClosure cl(is_alive); 1738 dictionary()->oops_do(&cl); 1739#endif 1740 return unloading_occurred; 1741} 1742 1743void SystemDictionary::oops_do(OopClosure* f) { 1744 f->do_oop(&_java_system_loader); 1745 f->do_oop(&_system_loader_lock_obj); 1746 1747 // Adjust dictionary 1748 dictionary()->oops_do(f); 1749 1750 // Visit extra methods 1751 invoke_method_table()->oops_do(f); 1752} 1753 1754// Extended Class redefinition support. 1755// If one of these classes is replaced, we need to replace it in these places. 1756// KlassClosure::do_klass should take the address of a class but we can 1757// change that later. 1758void SystemDictionary::preloaded_classes_do(KlassClosure* f) { 1759 for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) { 1760 f->do_klass(_well_known_klasses[k]); 1761 } 1762 1763 { 1764 for (int i = 0; i < T_VOID+1; i++) { 1765 if (_box_klasses[i] != NULL) { 1766 assert(i >= T_BOOLEAN, "checking"); 1767 f->do_klass(_box_klasses[i]); 1768 } 1769 } 1770 } 1771 1772 FilteredFieldsMap::classes_do(f); 1773} 1774 1775void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) { 1776 f->do_klass(_abstract_ownable_synchronizer_klass); 1777} 1778 1779// Just the classes from defining class loaders 1780// Don't iterate over placeholders 1781void SystemDictionary::classes_do(void f(Klass*)) { 1782 dictionary()->classes_do(f); 1783} 1784 1785// Added for initialize_itable_for_klass 1786// Just the classes from defining class loaders 1787// Don't iterate over placeholders 1788void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) { 1789 dictionary()->classes_do(f, CHECK); 1790} 1791 1792// All classes, and their class loaders 1793// Don't iterate over placeholders 1794void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) { 1795 dictionary()->classes_do(f); 1796} 1797 1798void SystemDictionary::placeholders_do(void f(Symbol*)) { 1799 placeholders()->entries_do(f); 1800} 1801 1802void SystemDictionary::methods_do(void f(Method*)) { 1803 dictionary()->methods_do(f); 1804 invoke_method_table()->methods_do(f); 1805} 1806 1807// ---------------------------------------------------------------------------- 1808// Lazily load klasses 1809 1810void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) { 1811 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later"); 1812 1813 // if multiple threads calling this function, only one thread will load 1814 // the class. The other threads will find the loaded version once the 1815 // class is loaded. 1816 Klass* aos = _abstract_ownable_synchronizer_klass; 1817 if (aos == NULL) { 1818 Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK); 1819 // Force a fence to prevent any read before the write completes 1820 OrderAccess::fence(); 1821 _abstract_ownable_synchronizer_klass = k; 1822 } 1823} 1824 1825// ---------------------------------------------------------------------------- 1826// Initialization 1827 1828void SystemDictionary::initialize(TRAPS) { 1829 // Allocate arrays 1830 assert(dictionary() == NULL, 1831 "SystemDictionary should only be initialized once"); 1832 _sdgeneration = 0; 1833 _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount)); 1834 _placeholders = new PlaceholderTable(_nof_buckets); 1835 _number_of_modifications = 0; 1836 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size); 1837 _resolution_errors = new ResolutionErrorTable(_resolution_error_size); 1838 _invoke_method_table = new SymbolPropertyTable(_invoke_method_size); 1839 1840 // Allocate private object used as system class loader lock 1841 _system_loader_lock_obj = oopFactory::new_intArray(0, CHECK); 1842 // Initialize basic classes 1843 initialize_preloaded_classes(CHECK); 1844} 1845 1846// Compact table of directions on the initialization of klasses: 1847static const short wk_init_info[] = { 1848 #define WK_KLASS_INIT_INFO(name, symbol, option) \ 1849 ( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \ 1850 << SystemDictionary::CEIL_LG_OPTION_LIMIT) \ 1851 | (int)SystemDictionary::option ), 1852 WK_KLASSES_DO(WK_KLASS_INIT_INFO) 1853 #undef WK_KLASS_INIT_INFO 1854 0 1855}; 1856 1857bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) { 1858 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 1859 int info = wk_init_info[id - FIRST_WKID]; 1860 int sid = (info >> CEIL_LG_OPTION_LIMIT); 1861 Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid); 1862 Klass** klassp = &_well_known_klasses[id]; 1863 bool must_load = (init_opt < SystemDictionary::Opt); 1864 if ((*klassp) == NULL) { 1865 if (must_load) { 1866 (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class 1867 } else { 1868 (*klassp) = resolve_or_null(symbol, CHECK_0); // load optional klass 1869 } 1870 } 1871 return ((*klassp) != NULL); 1872} 1873 1874void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) { 1875 assert((int)start_id <= (int)limit_id, "IDs are out of order!"); 1876 for (int id = (int)start_id; id < (int)limit_id; id++) { 1877 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 1878 int info = wk_init_info[id - FIRST_WKID]; 1879 int sid = (info >> CEIL_LG_OPTION_LIMIT); 1880 int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT)); 1881 1882 initialize_wk_klass((WKID)id, opt, CHECK); 1883 } 1884 1885 // move the starting value forward to the limit: 1886 start_id = limit_id; 1887} 1888 1889void SystemDictionary::initialize_preloaded_classes(TRAPS) { 1890 assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once"); 1891 // Preload commonly used klasses 1892 WKID scan = FIRST_WKID; 1893 // first do Object, then String, Class 1894 if (UseSharedSpaces) { 1895 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK); 1896 // Initialize the constant pool for the Object_class 1897 InstanceKlass* ik = InstanceKlass::cast(Object_klass()); 1898 ik->constants()->restore_unshareable_info(CHECK); 1899 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK); 1900 } else { 1901 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK); 1902 } 1903 1904 // Calculate offsets for String and Class classes since they are loaded and 1905 // can be used after this point. 1906 java_lang_String::compute_offsets(); 1907 java_lang_Class::compute_offsets(); 1908 1909 // Fixup mirrors for classes loaded before java.lang.Class. 1910 // These calls iterate over the objects currently in the perm gen 1911 // so calling them at this point is matters (not before when there 1912 // are fewer objects and not later after there are more objects 1913 // in the perm gen. 1914 Universe::initialize_basic_type_mirrors(CHECK); 1915 Universe::fixup_mirrors(CHECK); 1916 1917 // do a bunch more: 1918 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK); 1919 1920 // Preload ref klasses and set reference types 1921 InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER); 1922 InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass)); 1923 1924 initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK); 1925 InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT); 1926 InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK); 1927 InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL); 1928 InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM); 1929 1930 // JSR 292 classes 1931 WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass); 1932 WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass); 1933 initialize_wk_klasses_until(jsr292_group_start, scan, CHECK); 1934 if (EnableInvokeDynamic) { 1935 initialize_wk_klasses_through(jsr292_group_end, scan, CHECK); 1936 } else { 1937 // Skip the JSR 292 classes, if not enabled. 1938 scan = WKID(jsr292_group_end + 1); 1939 } 1940 1941 initialize_wk_klasses_until(WKID_LIMIT, scan, CHECK); 1942 1943 _box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass); 1944 _box_klasses[T_CHAR] = WK_KLASS(Character_klass); 1945 _box_klasses[T_FLOAT] = WK_KLASS(Float_klass); 1946 _box_klasses[T_DOUBLE] = WK_KLASS(Double_klass); 1947 _box_klasses[T_BYTE] = WK_KLASS(Byte_klass); 1948 _box_klasses[T_SHORT] = WK_KLASS(Short_klass); 1949 _box_klasses[T_INT] = WK_KLASS(Integer_klass); 1950 _box_klasses[T_LONG] = WK_KLASS(Long_klass); 1951 //_box_klasses[T_OBJECT] = WK_KLASS(object_klass); 1952 //_box_klasses[T_ARRAY] = WK_KLASS(object_klass); 1953 1954 { // Compute whether we should use loadClass or loadClassInternal when loading classes. 1955 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature()); 1956 _has_loadClassInternal = (method != NULL); 1957 } 1958 { // Compute whether we should use checkPackageAccess or NOT 1959 Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature()); 1960 _has_checkPackageAccess = (method != NULL); 1961 } 1962} 1963 1964// Tells if a given klass is a box (wrapper class, such as java.lang.Integer). 1965// If so, returns the basic type it holds. If not, returns T_OBJECT. 1966BasicType SystemDictionary::box_klass_type(Klass* k) { 1967 assert(k != NULL, ""); 1968 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 1969 if (_box_klasses[i] == k) 1970 return (BasicType)i; 1971 } 1972 return T_OBJECT; 1973} 1974 1975// Constraints on class loaders. The details of the algorithm can be 1976// found in the OOPSLA'98 paper "Dynamic Class Loading in the Java 1977// Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is 1978// that the system dictionary needs to maintain a set of contraints that 1979// must be satisfied by all classes in the dictionary. 1980// if defining is true, then LinkageError if already in systemDictionary 1981// if initiating loader, then ok if InstanceKlass matches existing entry 1982 1983void SystemDictionary::check_constraints(int d_index, unsigned int d_hash, 1984 instanceKlassHandle k, 1985 Handle class_loader, bool defining, 1986 TRAPS) { 1987 const char *linkage_error = NULL; 1988 { 1989 Symbol* name = k->name(); 1990 ClassLoaderData *loader_data = class_loader_data(class_loader); 1991 1992 MutexLocker mu(SystemDictionary_lock, THREAD); 1993 1994 Klass* check = find_class(d_index, d_hash, name, loader_data); 1995 if (check != (Klass*)NULL) { 1996 // if different InstanceKlass - duplicate class definition, 1997 // else - ok, class loaded by a different thread in parallel, 1998 // we should only have found it if it was done loading and ok to use 1999 // system dictionary only holds instance classes, placeholders 2000 // also holds array classes 2001 2002 assert(check->oop_is_instance(), "noninstance in systemdictionary"); 2003 if ((defining == true) || (k() != check)) { 2004 linkage_error = "loader (instance of %s): attempted duplicate class " 2005 "definition for name: \"%s\""; 2006 } else { 2007 return; 2008 } 2009 } 2010 2011#ifdef ASSERT 2012 Symbol* ph_check = find_placeholder(name, loader_data); 2013 assert(ph_check == NULL || ph_check == name, "invalid symbol"); 2014#endif 2015 2016 if (linkage_error == NULL) { 2017 if (constraints()->check_or_update(k, class_loader, name) == false) { 2018 linkage_error = "loader constraint violation: loader (instance of %s)" 2019 " previously initiated loading for a different type with name \"%s\""; 2020 } 2021 } 2022 } 2023 2024 // Throw error now if needed (cannot throw while holding 2025 // SystemDictionary_lock because of rank ordering) 2026 2027 if (linkage_error) { 2028 ResourceMark rm(THREAD); 2029 const char* class_loader_name = loader_name(class_loader()); 2030 char* type_name = k->name()->as_C_string(); 2031 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) + 2032 strlen(type_name); 2033 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen); 2034 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name); 2035 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf); 2036 } 2037} 2038 2039 2040// Update system dictionary - done after check_constraint and add_to_hierachy 2041// have been called. 2042void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash, 2043 int p_index, unsigned int p_hash, 2044 instanceKlassHandle k, 2045 Handle class_loader, 2046 TRAPS) { 2047 // Compile_lock prevents systemDictionary updates during compilations 2048 assert_locked_or_safepoint(Compile_lock); 2049 Symbol* name = k->name(); 2050 ClassLoaderData *loader_data = class_loader_data(class_loader); 2051 2052 { 2053 MutexLocker mu1(SystemDictionary_lock, THREAD); 2054 2055 // See whether biased locking is enabled and if so set it for this 2056 // klass. 2057 // Note that this must be done past the last potential blocking 2058 // point / safepoint. We enable biased locking lazily using a 2059 // VM_Operation to iterate the SystemDictionary and installing the 2060 // biasable mark word into each InstanceKlass's prototype header. 2061 // To avoid race conditions where we accidentally miss enabling the 2062 // optimization for one class in the process of being added to the 2063 // dictionary, we must not safepoint after the test of 2064 // BiasedLocking::enabled(). 2065 if (UseBiasedLocking && BiasedLocking::enabled()) { 2066 // Set biased locking bit for all loaded classes; it will be 2067 // cleared if revocation occurs too often for this type 2068 // NOTE that we must only do this when the class is initally 2069 // defined, not each time it is referenced from a new class loader 2070 if (k->class_loader() == class_loader()) { 2071 k->set_prototype_header(markOopDesc::biased_locking_prototype()); 2072 } 2073 } 2074 2075 // Make a new system dictionary entry. 2076 Klass* sd_check = find_class(d_index, d_hash, name, loader_data); 2077 if (sd_check == NULL) { 2078 dictionary()->add_klass(name, loader_data, k); 2079 notice_modification(); 2080 } 2081#ifdef ASSERT 2082 sd_check = find_class(d_index, d_hash, name, loader_data); 2083 assert (sd_check != NULL, "should have entry in system dictionary"); 2084 // Note: there may be a placeholder entry: for circularity testing 2085 // or for parallel defines 2086#endif 2087 SystemDictionary_lock->notify_all(); 2088 } 2089} 2090 2091 2092// Try to find a class name using the loader constraints. The 2093// loader constraints might know about a class that isn't fully loaded 2094// yet and these will be ignored. 2095Klass* SystemDictionary::find_constrained_instance_or_array_klass( 2096 Symbol* class_name, Handle class_loader, TRAPS) { 2097 2098 // First see if it has been loaded directly. 2099 // Force the protection domain to be null. (This removes protection checks.) 2100 Handle no_protection_domain; 2101 Klass* klass = find_instance_or_array_klass(class_name, class_loader, 2102 no_protection_domain, CHECK_NULL); 2103 if (klass != NULL) 2104 return klass; 2105 2106 // Now look to see if it has been loaded elsewhere, and is subject to 2107 // a loader constraint that would require this loader to return the 2108 // klass that is already loaded. 2109 if (FieldType::is_array(class_name)) { 2110 // For array classes, their Klass*s are not kept in the 2111 // constraint table. The element Klass*s are. 2112 FieldArrayInfo fd; 2113 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL)); 2114 if (t != T_OBJECT) { 2115 klass = Universe::typeArrayKlassObj(t); 2116 } else { 2117 MutexLocker mu(SystemDictionary_lock, THREAD); 2118 klass = constraints()->find_constrained_klass(fd.object_key(), class_loader); 2119 } 2120 // If element class already loaded, allocate array klass 2121 if (klass != NULL) { 2122 klass = klass->array_klass_or_null(fd.dimension()); 2123 } 2124 } else { 2125 MutexLocker mu(SystemDictionary_lock, THREAD); 2126 // Non-array classes are easy: simply check the constraint table. 2127 klass = constraints()->find_constrained_klass(class_name, class_loader); 2128 } 2129 2130 return klass; 2131} 2132 2133 2134bool SystemDictionary::add_loader_constraint(Symbol* class_name, 2135 Handle class_loader1, 2136 Handle class_loader2, 2137 Thread* THREAD) { 2138 ClassLoaderData* loader_data1 = class_loader_data(class_loader1); 2139 ClassLoaderData* loader_data2 = class_loader_data(class_loader2); 2140 2141 Symbol* constraint_name = NULL; 2142 if (!FieldType::is_array(class_name)) { 2143 constraint_name = class_name; 2144 } else { 2145 // For array classes, their Klass*s are not kept in the 2146 // constraint table. The element classes are. 2147 FieldArrayInfo fd; 2148 BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false)); 2149 // primitive types always pass 2150 if (t != T_OBJECT) { 2151 return true; 2152 } else { 2153 constraint_name = fd.object_key(); 2154 } 2155 } 2156 unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1); 2157 int d_index1 = dictionary()->hash_to_index(d_hash1); 2158 2159 unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2); 2160 int d_index2 = dictionary()->hash_to_index(d_hash2); 2161 { 2162 MutexLocker mu_s(SystemDictionary_lock, THREAD); 2163 2164 // Better never do a GC while we're holding these oops 2165 No_Safepoint_Verifier nosafepoint; 2166 2167 Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1); 2168 Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2); 2169 return constraints()->add_entry(constraint_name, klass1, class_loader1, 2170 klass2, class_loader2); 2171 } 2172} 2173 2174// Add entry to resolution error table to record the error when the first 2175// attempt to resolve a reference to a class has failed. 2176void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, Symbol* error) { 2177 unsigned int hash = resolution_errors()->compute_hash(pool, which); 2178 int index = resolution_errors()->hash_to_index(hash); 2179 { 2180 MutexLocker ml(SystemDictionary_lock, Thread::current()); 2181 resolution_errors()->add_entry(index, hash, pool, which, error); 2182 } 2183} 2184 2185// Delete a resolution error for RedefineClasses for a constant pool is going away 2186void SystemDictionary::delete_resolution_error(ConstantPool* pool) { 2187 resolution_errors()->delete_entry(pool); 2188} 2189 2190// Lookup resolution error table. Returns error if found, otherwise NULL. 2191Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) { 2192 unsigned int hash = resolution_errors()->compute_hash(pool, which); 2193 int index = resolution_errors()->hash_to_index(hash); 2194 { 2195 MutexLocker ml(SystemDictionary_lock, Thread::current()); 2196 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which); 2197 return (entry != NULL) ? entry->error() : (Symbol*)NULL; 2198 } 2199} 2200 2201 2202// Signature constraints ensure that callers and callees agree about 2203// the meaning of type names in their signatures. This routine is the 2204// intake for constraints. It collects them from several places: 2205// 2206// * LinkResolver::resolve_method (if check_access is true) requires 2207// that the resolving class (the caller) and the defining class of 2208// the resolved method (the callee) agree on each type in the 2209// method's signature. 2210// 2211// * LinkResolver::resolve_interface_method performs exactly the same 2212// checks. 2213// 2214// * LinkResolver::resolve_field requires that the constant pool 2215// attempting to link to a field agree with the field's defining 2216// class about the type of the field signature. 2217// 2218// * klassVtable::initialize_vtable requires that, when a class 2219// overrides a vtable entry allocated by a superclass, that the 2220// overriding method (i.e., the callee) agree with the superclass 2221// on each type in the method's signature. 2222// 2223// * klassItable::initialize_itable requires that, when a class fills 2224// in its itables, for each non-abstract method installed in an 2225// itable, the method (i.e., the callee) agree with the interface 2226// on each type in the method's signature. 2227// 2228// All those methods have a boolean (check_access, checkconstraints) 2229// which turns off the checks. This is used from specialized contexts 2230// such as bootstrapping, dumping, and debugging. 2231// 2232// No direct constraint is placed between the class and its 2233// supertypes. Constraints are only placed along linked relations 2234// between callers and callees. When a method overrides or implements 2235// an abstract method in a supertype (superclass or interface), the 2236// constraints are placed as if the supertype were the caller to the 2237// overriding method. (This works well, since callers to the 2238// supertype have already established agreement between themselves and 2239// the supertype.) As a result of all this, a class can disagree with 2240// its supertype about the meaning of a type name, as long as that 2241// class neither calls a relevant method of the supertype, nor is 2242// called (perhaps via an override) from the supertype. 2243// 2244// 2245// SystemDictionary::check_signature_loaders(sig, l1, l2) 2246// 2247// Make sure all class components (including arrays) in the given 2248// signature will be resolved to the same class in both loaders. 2249// Returns the name of the type that failed a loader constraint check, or 2250// NULL if no constraint failed. No exception except OOME is thrown. 2251// Arrays are not added to the loader constraint table, their elements are. 2252Symbol* SystemDictionary::check_signature_loaders(Symbol* signature, 2253 Handle loader1, Handle loader2, 2254 bool is_method, TRAPS) { 2255 // Nothing to do if loaders are the same. 2256 if (loader1() == loader2()) { 2257 return NULL; 2258 } 2259 2260 SignatureStream sig_strm(signature, is_method); 2261 while (!sig_strm.is_done()) { 2262 if (sig_strm.is_object()) { 2263 Symbol* sig = sig_strm.as_symbol(CHECK_NULL); 2264 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) { 2265 return sig; 2266 } 2267 } 2268 sig_strm.next(); 2269 } 2270 return NULL; 2271} 2272 2273 2274methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid, 2275 Symbol* signature, 2276 TRAPS) { 2277 methodHandle empty; 2278 assert(EnableInvokeDynamic, ""); 2279 assert(MethodHandles::is_signature_polymorphic(iid) && 2280 MethodHandles::is_signature_polymorphic_intrinsic(iid) && 2281 iid != vmIntrinsics::_invokeGeneric, 2282 err_msg("must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid))); 2283 2284 unsigned int hash = invoke_method_table()->compute_hash(signature, iid); 2285 int index = invoke_method_table()->hash_to_index(hash); 2286 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid); 2287 methodHandle m; 2288 if (spe == NULL || spe->method() == NULL) { 2289 spe = NULL; 2290 // Must create lots of stuff here, but outside of the SystemDictionary lock. 2291 m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty)); 2292 CompileBroker::compile_method(m, InvocationEntryBci, CompLevel_highest_tier, 2293 methodHandle(), CompileThreshold, "MH", CHECK_(empty)); 2294 2295 // Now grab the lock. We might have to throw away the new method, 2296 // if a racing thread has managed to install one at the same time. 2297 { 2298 MutexLocker ml(SystemDictionary_lock, THREAD); 2299 spe = invoke_method_table()->find_entry(index, hash, signature, iid); 2300 if (spe == NULL) 2301 spe = invoke_method_table()->add_entry(index, hash, signature, iid); 2302 if (spe->method() == NULL) 2303 spe->set_method(m()); 2304 } 2305 } 2306 2307 assert(spe != NULL && spe->method() != NULL, ""); 2308 return spe->method(); 2309} 2310 2311// Helper for unpacking the return value from linkMethod and linkCallSite. 2312static methodHandle unpack_method_and_appendix(Handle mname, 2313 KlassHandle accessing_klass, 2314 objArrayHandle appendix_box, 2315 Handle* appendix_result, 2316 TRAPS) { 2317 methodHandle empty; 2318 if (mname.not_null()) { 2319 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname()); 2320 if (vmtarget != NULL && vmtarget->is_method()) { 2321 Method* m = (Method*)vmtarget; 2322 oop appendix = appendix_box->obj_at(0); 2323 if (TraceMethodHandles) { 2324 #ifndef PRODUCT 2325 tty->print("Linked method="INTPTR_FORMAT": ", m); 2326 m->print(); 2327 if (appendix != NULL) { tty->print("appendix = "); appendix->print(); } 2328 tty->cr(); 2329 #endif //PRODUCT 2330 } 2331 (*appendix_result) = Handle(THREAD, appendix); 2332 // the target is stored in the cpCache and if a reference to this 2333 // MethodName is dropped we need a way to make sure the 2334 // class_loader containing this method is kept alive. 2335 // FIXME: the appendix might also preserve this dependency. 2336 ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data(); 2337 this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM 2338 return methodHandle(THREAD, m); 2339 } 2340 } 2341 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty); 2342 return empty; 2343} 2344 2345methodHandle SystemDictionary::find_method_handle_invoker(Symbol* name, 2346 Symbol* signature, 2347 KlassHandle accessing_klass, 2348 Handle *appendix_result, 2349 Handle *method_type_result, 2350 TRAPS) { 2351 methodHandle empty; 2352 assert(EnableInvokeDynamic, ""); 2353 assert(!THREAD->is_Compiler_thread(), ""); 2354 Handle method_type = 2355 SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty)); 2356 if (false) { // FIXME: Decide if the Java upcall should resolve signatures. 2357 method_type = java_lang_String::create_from_symbol(signature, CHECK_(empty)); 2358 } 2359 2360 KlassHandle mh_klass = SystemDictionary::MethodHandle_klass(); 2361 int ref_kind = JVM_REF_invokeVirtual; 2362 Handle name_str = StringTable::intern(name, CHECK_(empty)); 2363 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty)); 2364 assert(appendix_box->obj_at(0) == NULL, ""); 2365 2366 // This should not happen. JDK code should take care of that. 2367 if (accessing_klass.is_null() || method_type.is_null()) { 2368 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty); 2369 } 2370 2371 // call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName 2372 JavaCallArguments args; 2373 args.push_oop(accessing_klass()->java_mirror()); 2374 args.push_int(ref_kind); 2375 args.push_oop(mh_klass()->java_mirror()); 2376 args.push_oop(name_str()); 2377 args.push_oop(method_type()); 2378 args.push_oop(appendix_box()); 2379 JavaValue result(T_OBJECT); 2380 JavaCalls::call_static(&result, 2381 SystemDictionary::MethodHandleNatives_klass(), 2382 vmSymbols::linkMethod_name(), 2383 vmSymbols::linkMethod_signature(), 2384 &args, CHECK_(empty)); 2385 Handle mname(THREAD, (oop) result.get_jobject()); 2386 (*method_type_result) = method_type; 2387 return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD); 2388} 2389 2390 2391// Ask Java code to find or construct a java.lang.invoke.MethodType for the given 2392// signature, as interpreted relative to the given class loader. 2393// Because of class loader constraints, all method handle usage must be 2394// consistent with this loader. 2395Handle SystemDictionary::find_method_handle_type(Symbol* signature, 2396 KlassHandle accessing_klass, 2397 TRAPS) { 2398 Handle empty; 2399 vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics 2400 unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid); 2401 int index = invoke_method_table()->hash_to_index(hash); 2402 SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid); 2403 if (spe != NULL && spe->method_type() != NULL) { 2404 assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), ""); 2405 return Handle(THREAD, spe->method_type()); 2406 } else if (THREAD->is_Compiler_thread()) { 2407 warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME 2408 return Handle(); // do not attempt from within compiler, unless it was cached 2409 } 2410 2411 Handle class_loader, protection_domain; 2412 bool is_on_bcp = true; // keep this true as long as we can materialize from the boot classloader 2413 int npts = ArgumentCount(signature).size(); 2414 objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty)); 2415 int arg = 0; 2416 Handle rt; // the return type from the signature 2417 ResourceMark rm(THREAD); 2418 for (SignatureStream ss(signature); !ss.is_done(); ss.next()) { 2419 oop mirror = NULL; 2420 if (is_on_bcp) { 2421 // Note: class_loader & protection_domain are both null at this point. 2422 mirror = ss.as_java_mirror(class_loader, protection_domain, 2423 SignatureStream::ReturnNull, CHECK_(empty)); 2424 if (mirror == NULL) { 2425 // fall back from BCP to accessing_klass 2426 if (accessing_klass.not_null()) { 2427 class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader()); 2428 protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain()); 2429 } 2430 is_on_bcp = false; 2431 } 2432 } 2433 if (!is_on_bcp) { 2434 // Resolve, throwing a real error if it doesn't work. 2435 mirror = ss.as_java_mirror(class_loader, protection_domain, 2436 SignatureStream::NCDFError, CHECK_(empty)); 2437 } 2438 if (ss.at_return_type()) 2439 rt = Handle(THREAD, mirror); 2440 else 2441 pts->obj_at_put(arg++, mirror); 2442 2443 // Check accessibility. 2444 if (ss.is_object() && accessing_klass.not_null()) { 2445 Klass* sel_klass = java_lang_Class::as_Klass(mirror); 2446 mirror = NULL; // safety 2447 // Emulate ConstantPool::verify_constant_pool_resolve. 2448 if (sel_klass->oop_is_objArray()) 2449 sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass(); 2450 if (sel_klass->oop_is_instance()) { 2451 KlassHandle sel_kh(THREAD, sel_klass); 2452 LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty)); 2453 } 2454 } 2455 } 2456 assert(arg == npts, ""); 2457 2458 // call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType 2459 JavaCallArguments args(Handle(THREAD, rt())); 2460 args.push_oop(pts()); 2461 JavaValue result(T_OBJECT); 2462 JavaCalls::call_static(&result, 2463 SystemDictionary::MethodHandleNatives_klass(), 2464 vmSymbols::findMethodHandleType_name(), 2465 vmSymbols::findMethodHandleType_signature(), 2466 &args, CHECK_(empty)); 2467 Handle method_type(THREAD, (oop) result.get_jobject()); 2468 2469 if (is_on_bcp) { 2470 // We can cache this MethodType inside the JVM. 2471 MutexLocker ml(SystemDictionary_lock, THREAD); 2472 spe = invoke_method_table()->find_entry(index, hash, signature, null_iid); 2473 if (spe == NULL) 2474 spe = invoke_method_table()->add_entry(index, hash, signature, null_iid); 2475 if (spe->method_type() == NULL) { 2476 spe->set_method_type(method_type()); 2477 } 2478 } 2479 2480 // report back to the caller with the MethodType 2481 return method_type; 2482} 2483 2484// Ask Java code to find or construct a method handle constant. 2485Handle SystemDictionary::link_method_handle_constant(KlassHandle caller, 2486 int ref_kind, //e.g., JVM_REF_invokeVirtual 2487 KlassHandle callee, 2488 Symbol* name_sym, 2489 Symbol* signature, 2490 TRAPS) { 2491 Handle empty; 2492 Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty)); 2493 Handle type; 2494 if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') { 2495 type = find_method_handle_type(signature, caller, CHECK_(empty)); 2496 } else if (caller.is_null()) { 2497 // This should not happen. JDK code should take care of that. 2498 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty); 2499 } else { 2500 ResourceMark rm(THREAD); 2501 SignatureStream ss(signature, false); 2502 if (!ss.is_done()) { 2503 oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(), 2504 SignatureStream::NCDFError, CHECK_(empty)); 2505 type = Handle(THREAD, mirror); 2506 ss.next(); 2507 if (!ss.is_done()) type = Handle(); // error! 2508 } 2509 } 2510 if (type.is_null()) { 2511 THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty); 2512 } 2513 2514 // call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle 2515 JavaCallArguments args; 2516 args.push_oop(caller->java_mirror()); // the referring class 2517 args.push_int(ref_kind); 2518 args.push_oop(callee->java_mirror()); // the target class 2519 args.push_oop(name()); 2520 args.push_oop(type()); 2521 JavaValue result(T_OBJECT); 2522 JavaCalls::call_static(&result, 2523 SystemDictionary::MethodHandleNatives_klass(), 2524 vmSymbols::linkMethodHandleConstant_name(), 2525 vmSymbols::linkMethodHandleConstant_signature(), 2526 &args, CHECK_(empty)); 2527 return Handle(THREAD, (oop) result.get_jobject()); 2528} 2529 2530// Ask Java code to find or construct a java.lang.invoke.CallSite for the given 2531// name and signature, as interpreted relative to the given class loader. 2532methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller, 2533 Handle bootstrap_specifier, 2534 Symbol* name, 2535 Symbol* type, 2536 Handle *appendix_result, 2537 Handle *method_type_result, 2538 TRAPS) { 2539 methodHandle empty; 2540 Handle bsm, info; 2541 if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) { 2542 bsm = bootstrap_specifier; 2543 } else { 2544 assert(bootstrap_specifier->is_objArray(), ""); 2545 objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier()); 2546 int len = args->length(); 2547 assert(len >= 1, ""); 2548 bsm = Handle(THREAD, args->obj_at(0)); 2549 if (len > 1) { 2550 objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty)); 2551 for (int i = 1; i < len; i++) 2552 args1->obj_at_put(i-1, args->obj_at(i)); 2553 info = Handle(THREAD, args1); 2554 } 2555 } 2556 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()), 2557 "caller must supply a valid BSM"); 2558 2559 Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty)); 2560 Handle method_type = find_method_handle_type(type, caller, CHECK_(empty)); 2561 2562 // This should not happen. JDK code should take care of that. 2563 if (caller.is_null() || method_type.is_null()) { 2564 THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty); 2565 } 2566 2567 objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty)); 2568 assert(appendix_box->obj_at(0) == NULL, ""); 2569 2570 // call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix) 2571 JavaCallArguments args; 2572 args.push_oop(caller->java_mirror()); 2573 args.push_oop(bsm()); 2574 args.push_oop(method_name()); 2575 args.push_oop(method_type()); 2576 args.push_oop(info()); 2577 args.push_oop(appendix_box); 2578 JavaValue result(T_OBJECT); 2579 JavaCalls::call_static(&result, 2580 SystemDictionary::MethodHandleNatives_klass(), 2581 vmSymbols::linkCallSite_name(), 2582 vmSymbols::linkCallSite_signature(), 2583 &args, CHECK_(empty)); 2584 Handle mname(THREAD, (oop) result.get_jobject()); 2585 (*method_type_result) = method_type; 2586 return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD); 2587} 2588 2589// Since the identity hash code for symbols changes when the symbols are 2590// moved from the regular perm gen (hash in the mark word) to the shared 2591// spaces (hash is the address), the classes loaded into the dictionary 2592// may be in the wrong buckets. 2593 2594void SystemDictionary::reorder_dictionary() { 2595 dictionary()->reorder_dictionary(); 2596} 2597 2598 2599void SystemDictionary::copy_buckets(char** top, char* end) { 2600 dictionary()->copy_buckets(top, end); 2601} 2602 2603 2604void SystemDictionary::copy_table(char** top, char* end) { 2605 dictionary()->copy_table(top, end); 2606} 2607 2608 2609void SystemDictionary::reverse() { 2610 dictionary()->reverse(); 2611} 2612 2613int SystemDictionary::number_of_classes() { 2614 return dictionary()->number_of_entries(); 2615} 2616 2617 2618// ---------------------------------------------------------------------------- 2619#ifndef PRODUCT 2620 2621void SystemDictionary::print() { 2622 dictionary()->print(); 2623 2624 // Placeholders 2625 GCMutexLocker mu(SystemDictionary_lock); 2626 placeholders()->print(); 2627 2628 // loader constraints - print under SD_lock 2629 constraints()->print(); 2630} 2631 2632#endif 2633 2634void SystemDictionary::verify() { 2635 guarantee(dictionary() != NULL, "Verify of system dictionary failed"); 2636 guarantee(constraints() != NULL, 2637 "Verify of loader constraints failed"); 2638 guarantee(dictionary()->number_of_entries() >= 0 && 2639 placeholders()->number_of_entries() >= 0, 2640 "Verify of system dictionary failed"); 2641 2642 // Verify dictionary 2643 dictionary()->verify(); 2644 2645 GCMutexLocker mu(SystemDictionary_lock); 2646 placeholders()->verify(); 2647 2648 // Verify constraint table 2649 guarantee(constraints() != NULL, "Verify of loader constraints failed"); 2650 constraints()->verify(dictionary(), placeholders()); 2651} 2652 2653// utility function for class load event 2654void SystemDictionary::post_class_load_event(const Ticks& start_time, 2655 instanceKlassHandle k, 2656 Handle initiating_loader) { 2657#if INCLUDE_TRACE 2658 EventClassLoad event(UNTIMED); 2659 if (event.should_commit()) { 2660 event.set_starttime(start_time); 2661 event.set_loadedClass(k()); 2662 oop defining_class_loader = k->class_loader(); 2663 event.set_definingClassLoader(defining_class_loader != NULL ? 2664 defining_class_loader->klass() : (Klass*)NULL); 2665 oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader(); 2666 event.set_initiatingClassLoader(class_loader != NULL ? 2667 class_loader->klass() : (Klass*)NULL); 2668 event.commit(); 2669 } 2670#endif /* INCLUDE_TRACE */ 2671} 2672 2673#ifndef PRODUCT 2674 2675// statistics code 2676class ClassStatistics: AllStatic { 2677 private: 2678 static int nclasses; // number of classes 2679 static int nmethods; // number of methods 2680 static int nmethoddata; // number of methodData 2681 static int class_size; // size of class objects in words 2682 static int method_size; // size of method objects in words 2683 static int debug_size; // size of debug info in methods 2684 static int methoddata_size; // size of methodData objects in words 2685 2686 static void do_class(Klass* k) { 2687 nclasses++; 2688 class_size += k->size(); 2689 if (k->oop_is_instance()) { 2690 InstanceKlass* ik = (InstanceKlass*)k; 2691 class_size += ik->methods()->size(); 2692 class_size += ik->constants()->size(); 2693 class_size += ik->local_interfaces()->size(); 2694 class_size += ik->transitive_interfaces()->size(); 2695 // We do not have to count implementors, since we only store one! 2696 // SSS: How should these be accounted now that they have moved? 2697 // class_size += ik->fields()->length(); 2698 } 2699 } 2700 2701 static void do_method(Method* m) { 2702 nmethods++; 2703 method_size += m->size(); 2704 // class loader uses same objArray for empty vectors, so don't count these 2705 if (m->has_stackmap_table()) { 2706 method_size += m->stackmap_data()->size(); 2707 } 2708 2709 MethodData* mdo = m->method_data(); 2710 if (mdo != NULL) { 2711 nmethoddata++; 2712 methoddata_size += mdo->size(); 2713 } 2714 } 2715 2716 public: 2717 static void print() { 2718 SystemDictionary::classes_do(do_class); 2719 SystemDictionary::methods_do(do_method); 2720 tty->print_cr("Class statistics:"); 2721 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize); 2722 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods, 2723 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize); 2724 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize); 2725 } 2726}; 2727 2728 2729int ClassStatistics::nclasses = 0; 2730int ClassStatistics::nmethods = 0; 2731int ClassStatistics::nmethoddata = 0; 2732int ClassStatistics::class_size = 0; 2733int ClassStatistics::method_size = 0; 2734int ClassStatistics::debug_size = 0; 2735int ClassStatistics::methoddata_size = 0; 2736 2737void SystemDictionary::print_class_statistics() { 2738 ResourceMark rm; 2739 ClassStatistics::print(); 2740} 2741 2742 2743class MethodStatistics: AllStatic { 2744 public: 2745 enum { 2746 max_parameter_size = 10 2747 }; 2748 private: 2749 2750 static int _number_of_methods; 2751 static int _number_of_final_methods; 2752 static int _number_of_static_methods; 2753 static int _number_of_native_methods; 2754 static int _number_of_synchronized_methods; 2755 static int _number_of_profiled_methods; 2756 static int _number_of_bytecodes; 2757 static int _parameter_size_profile[max_parameter_size]; 2758 static int _bytecodes_profile[Bytecodes::number_of_java_codes]; 2759 2760 static void initialize() { 2761 _number_of_methods = 0; 2762 _number_of_final_methods = 0; 2763 _number_of_static_methods = 0; 2764 _number_of_native_methods = 0; 2765 _number_of_synchronized_methods = 0; 2766 _number_of_profiled_methods = 0; 2767 _number_of_bytecodes = 0; 2768 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0; 2769 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0; 2770 }; 2771 2772 static void do_method(Method* m) { 2773 _number_of_methods++; 2774 // collect flag info 2775 if (m->is_final() ) _number_of_final_methods++; 2776 if (m->is_static() ) _number_of_static_methods++; 2777 if (m->is_native() ) _number_of_native_methods++; 2778 if (m->is_synchronized()) _number_of_synchronized_methods++; 2779 if (m->method_data() != NULL) _number_of_profiled_methods++; 2780 // collect parameter size info (add one for receiver, if any) 2781 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++; 2782 // collect bytecodes info 2783 { 2784 Thread *thread = Thread::current(); 2785 HandleMark hm(thread); 2786 BytecodeStream s(methodHandle(thread, m)); 2787 Bytecodes::Code c; 2788 while ((c = s.next()) >= 0) { 2789 _number_of_bytecodes++; 2790 _bytecodes_profile[c]++; 2791 } 2792 } 2793 } 2794 2795 public: 2796 static void print() { 2797 initialize(); 2798 SystemDictionary::methods_do(do_method); 2799 // generate output 2800 tty->cr(); 2801 tty->print_cr("Method statistics (static):"); 2802 // flag distribution 2803 tty->cr(); 2804 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods); 2805 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods); 2806 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods); 2807 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods); 2808 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods); 2809 // parameter size profile 2810 tty->cr(); 2811 { int tot = 0; 2812 int avg = 0; 2813 for (int i = 0; i < max_parameter_size; i++) { 2814 int n = _parameter_size_profile[i]; 2815 tot += n; 2816 avg += n*i; 2817 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods); 2818 } 2819 assert(tot == _number_of_methods, "should be the same"); 2820 tty->print_cr(" %6d methods 100.0%%", _number_of_methods); 2821 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods); 2822 } 2823 // bytecodes profile 2824 tty->cr(); 2825 { int tot = 0; 2826 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) { 2827 if (Bytecodes::is_defined(i)) { 2828 Bytecodes::Code c = Bytecodes::cast(i); 2829 int n = _bytecodes_profile[c]; 2830 tot += n; 2831 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c)); 2832 } 2833 } 2834 assert(tot == _number_of_bytecodes, "should be the same"); 2835 tty->print_cr("%9d 100.000%%", _number_of_bytecodes); 2836 } 2837 tty->cr(); 2838 } 2839}; 2840 2841int MethodStatistics::_number_of_methods; 2842int MethodStatistics::_number_of_final_methods; 2843int MethodStatistics::_number_of_static_methods; 2844int MethodStatistics::_number_of_native_methods; 2845int MethodStatistics::_number_of_synchronized_methods; 2846int MethodStatistics::_number_of_profiled_methods; 2847int MethodStatistics::_number_of_bytecodes; 2848int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size]; 2849int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes]; 2850 2851 2852void SystemDictionary::print_method_statistics() { 2853 MethodStatistics::print(); 2854} 2855 2856#endif // PRODUCT 2857