src/share/vm/classfile/systemDictionary.cpp

Wed, 09 Apr 2008 15:10:22 -0700

author
rasbold
date
Wed, 09 Apr 2008 15:10:22 -0700
changeset 544
9f4457a14b58
parent 457
90f5ddc7297b
child 567
60b728ec77c1
permissions
-rw-r--r--

Merge

duke@435 1 /*
duke@435 2 * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 # include "incls/_precompiled.incl"
duke@435 26 # include "incls/_systemDictionary.cpp.incl"
duke@435 27
duke@435 28
duke@435 29 Dictionary* SystemDictionary::_dictionary = NULL;
duke@435 30 PlaceholderTable* SystemDictionary::_placeholders = NULL;
duke@435 31 Dictionary* SystemDictionary::_shared_dictionary = NULL;
duke@435 32 LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
duke@435 33 ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
duke@435 34
duke@435 35
duke@435 36 int SystemDictionary::_number_of_modifications = 0;
duke@435 37
duke@435 38 oop SystemDictionary::_system_loader_lock_obj = NULL;
duke@435 39
duke@435 40 klassOop SystemDictionary::_object_klass = NULL;
duke@435 41 klassOop SystemDictionary::_string_klass = NULL;
duke@435 42 klassOop SystemDictionary::_class_klass = NULL;
duke@435 43 klassOop SystemDictionary::_cloneable_klass = NULL;
duke@435 44 klassOop SystemDictionary::_classloader_klass = NULL;
duke@435 45 klassOop SystemDictionary::_serializable_klass = NULL;
duke@435 46 klassOop SystemDictionary::_system_klass = NULL;
duke@435 47
duke@435 48 klassOop SystemDictionary::_throwable_klass = NULL;
duke@435 49 klassOop SystemDictionary::_error_klass = NULL;
duke@435 50 klassOop SystemDictionary::_threaddeath_klass = NULL;
duke@435 51 klassOop SystemDictionary::_exception_klass = NULL;
duke@435 52 klassOop SystemDictionary::_runtime_exception_klass = NULL;
duke@435 53 klassOop SystemDictionary::_classNotFoundException_klass = NULL;
duke@435 54 klassOop SystemDictionary::_noClassDefFoundError_klass = NULL;
duke@435 55 klassOop SystemDictionary::_linkageError_klass = NULL;
duke@435 56 klassOop SystemDictionary::_classCastException_klass = NULL;
duke@435 57 klassOop SystemDictionary::_arrayStoreException_klass = NULL;
duke@435 58 klassOop SystemDictionary::_virtualMachineError_klass = NULL;
duke@435 59 klassOop SystemDictionary::_outOfMemoryError_klass = NULL;
duke@435 60 klassOop SystemDictionary::_StackOverflowError_klass = NULL;
duke@435 61 klassOop SystemDictionary::_illegalMonitorStateException_klass = NULL;
duke@435 62 klassOop SystemDictionary::_protectionDomain_klass = NULL;
duke@435 63 klassOop SystemDictionary::_AccessControlContext_klass = NULL;
duke@435 64
duke@435 65 klassOop SystemDictionary::_reference_klass = NULL;
duke@435 66 klassOop SystemDictionary::_soft_reference_klass = NULL;
duke@435 67 klassOop SystemDictionary::_weak_reference_klass = NULL;
duke@435 68 klassOop SystemDictionary::_final_reference_klass = NULL;
duke@435 69 klassOop SystemDictionary::_phantom_reference_klass = NULL;
duke@435 70 klassOop SystemDictionary::_finalizer_klass = NULL;
duke@435 71
duke@435 72 klassOop SystemDictionary::_thread_klass = NULL;
duke@435 73 klassOop SystemDictionary::_threadGroup_klass = NULL;
duke@435 74 klassOop SystemDictionary::_properties_klass = NULL;
duke@435 75 klassOop SystemDictionary::_reflect_accessible_object_klass = NULL;
duke@435 76 klassOop SystemDictionary::_reflect_field_klass = NULL;
duke@435 77 klassOop SystemDictionary::_reflect_method_klass = NULL;
duke@435 78 klassOop SystemDictionary::_reflect_constructor_klass = NULL;
duke@435 79 klassOop SystemDictionary::_reflect_magic_klass = NULL;
duke@435 80 klassOop SystemDictionary::_reflect_method_accessor_klass = NULL;
duke@435 81 klassOop SystemDictionary::_reflect_constructor_accessor_klass = NULL;
duke@435 82 klassOop SystemDictionary::_reflect_delegating_classloader_klass = NULL;
duke@435 83 klassOop SystemDictionary::_reflect_constant_pool_klass = NULL;
duke@435 84 klassOop SystemDictionary::_reflect_unsafe_static_field_accessor_impl_klass = NULL;
duke@435 85
duke@435 86 klassOop SystemDictionary::_vector_klass = NULL;
duke@435 87 klassOop SystemDictionary::_hashtable_klass = NULL;
duke@435 88 klassOop SystemDictionary::_stringBuffer_klass = NULL;
duke@435 89
duke@435 90 klassOop SystemDictionary::_stackTraceElement_klass = NULL;
duke@435 91
duke@435 92 klassOop SystemDictionary::_java_nio_Buffer_klass = NULL;
duke@435 93
duke@435 94 klassOop SystemDictionary::_sun_misc_AtomicLongCSImpl_klass = NULL;
duke@435 95 klassOop SystemDictionary::_sun_jkernel_DownloadManager_klass = NULL;
duke@435 96
duke@435 97 klassOop SystemDictionary::_boolean_klass = NULL;
duke@435 98 klassOop SystemDictionary::_char_klass = NULL;
duke@435 99 klassOop SystemDictionary::_float_klass = NULL;
duke@435 100 klassOop SystemDictionary::_double_klass = NULL;
duke@435 101 klassOop SystemDictionary::_byte_klass = NULL;
duke@435 102 klassOop SystemDictionary::_short_klass = NULL;
duke@435 103 klassOop SystemDictionary::_int_klass = NULL;
duke@435 104 klassOop SystemDictionary::_long_klass = NULL;
duke@435 105 klassOop SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
duke@435 106
duke@435 107 oop SystemDictionary::_java_system_loader = NULL;
duke@435 108
duke@435 109 bool SystemDictionary::_has_loadClassInternal = false;
duke@435 110 bool SystemDictionary::_has_checkPackageAccess = false;
duke@435 111
duke@435 112 // lazily initialized klass variables
duke@435 113 volatile klassOop SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
duke@435 114
duke@435 115
duke@435 116 // ----------------------------------------------------------------------------
duke@435 117 // Java-level SystemLoader
duke@435 118
duke@435 119 oop SystemDictionary::java_system_loader() {
duke@435 120 return _java_system_loader;
duke@435 121 }
duke@435 122
duke@435 123 void SystemDictionary::compute_java_system_loader(TRAPS) {
duke@435 124 KlassHandle system_klass(THREAD, _classloader_klass);
duke@435 125 JavaValue result(T_OBJECT);
duke@435 126 JavaCalls::call_static(&result,
duke@435 127 KlassHandle(THREAD, _classloader_klass),
duke@435 128 vmSymbolHandles::getSystemClassLoader_name(),
duke@435 129 vmSymbolHandles::void_classloader_signature(),
duke@435 130 CHECK);
duke@435 131
duke@435 132 _java_system_loader = (oop)result.get_jobject();
duke@435 133 }
duke@435 134
duke@435 135
duke@435 136 // ----------------------------------------------------------------------------
duke@435 137 // debugging
duke@435 138
duke@435 139 #ifdef ASSERT
duke@435 140
duke@435 141 // return true if class_name contains no '.' (internal format is '/')
duke@435 142 bool SystemDictionary::is_internal_format(symbolHandle class_name) {
duke@435 143 if (class_name.not_null()) {
duke@435 144 ResourceMark rm;
duke@435 145 char* name = class_name->as_C_string();
duke@435 146 return strchr(name, '.') == NULL;
duke@435 147 } else {
duke@435 148 return true;
duke@435 149 }
duke@435 150 }
duke@435 151
duke@435 152 #endif
duke@435 153
duke@435 154 // ----------------------------------------------------------------------------
duke@435 155 // Resolving of classes
duke@435 156
duke@435 157 // Forwards to resolve_or_null
duke@435 158
duke@435 159 klassOop SystemDictionary::resolve_or_fail(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
duke@435 160 klassOop klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
duke@435 161 if (HAS_PENDING_EXCEPTION || klass == NULL) {
duke@435 162 KlassHandle k_h(THREAD, klass);
duke@435 163 // can return a null klass
duke@435 164 klass = handle_resolution_exception(class_name, class_loader, protection_domain, throw_error, k_h, THREAD);
duke@435 165 }
duke@435 166 return klass;
duke@435 167 }
duke@435 168
duke@435 169 klassOop SystemDictionary::handle_resolution_exception(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS) {
duke@435 170 if (HAS_PENDING_EXCEPTION) {
duke@435 171 // If we have a pending exception we forward it to the caller, unless throw_error is true,
duke@435 172 // in which case we have to check whether the pending exception is a ClassNotFoundException,
duke@435 173 // and if so convert it to a NoClassDefFoundError
duke@435 174 // And chain the original ClassNotFoundException
duke@435 175 if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::classNotFoundException_klass())) {
duke@435 176 ResourceMark rm(THREAD);
duke@435 177 assert(klass_h() == NULL, "Should not have result with exception pending");
duke@435 178 Handle e(THREAD, PENDING_EXCEPTION);
duke@435 179 CLEAR_PENDING_EXCEPTION;
duke@435 180 THROW_MSG_CAUSE_0(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
duke@435 181 } else {
duke@435 182 return NULL;
duke@435 183 }
duke@435 184 }
duke@435 185 // Class not found, throw appropriate error or exception depending on value of throw_error
duke@435 186 if (klass_h() == NULL) {
duke@435 187 ResourceMark rm(THREAD);
duke@435 188 if (throw_error) {
duke@435 189 THROW_MSG_0(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
duke@435 190 } else {
duke@435 191 THROW_MSG_0(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
duke@435 192 }
duke@435 193 }
duke@435 194 return (klassOop)klass_h();
duke@435 195 }
duke@435 196
duke@435 197
duke@435 198 klassOop SystemDictionary::resolve_or_fail(symbolHandle class_name,
duke@435 199 bool throw_error, TRAPS)
duke@435 200 {
duke@435 201 return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
duke@435 202 }
duke@435 203
duke@435 204
duke@435 205 // Forwards to resolve_instance_class_or_null
duke@435 206
duke@435 207 klassOop SystemDictionary::resolve_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS) {
duke@435 208 assert(!THREAD->is_Compiler_thread(), "Can not load classes with the Compiler thread");
duke@435 209 if (FieldType::is_array(class_name())) {
duke@435 210 return resolve_array_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
duke@435 211 } else {
duke@435 212 return resolve_instance_class_or_null(class_name, class_loader, protection_domain, CHECK_NULL);
duke@435 213 }
duke@435 214 }
duke@435 215
duke@435 216 klassOop SystemDictionary::resolve_or_null(symbolHandle class_name, TRAPS) {
duke@435 217 return resolve_or_null(class_name, Handle(), Handle(), THREAD);
duke@435 218 }
duke@435 219
duke@435 220 // Forwards to resolve_instance_class_or_null
duke@435 221
duke@435 222 klassOop SystemDictionary::resolve_array_class_or_null(symbolHandle class_name,
duke@435 223 Handle class_loader,
duke@435 224 Handle protection_domain,
duke@435 225 TRAPS) {
duke@435 226 assert(FieldType::is_array(class_name()), "must be array");
duke@435 227 jint dimension;
duke@435 228 symbolOop object_key;
duke@435 229 klassOop k = NULL;
duke@435 230 // dimension and object_key are assigned as a side-effect of this call
duke@435 231 BasicType t = FieldType::get_array_info(class_name(),
duke@435 232 &dimension,
duke@435 233 &object_key,
duke@435 234 CHECK_NULL);
duke@435 235
duke@435 236 if (t == T_OBJECT) {
duke@435 237 symbolHandle h_key(THREAD, object_key);
duke@435 238 // naked oop "k" is OK here -- we assign back into it
duke@435 239 k = SystemDictionary::resolve_instance_class_or_null(h_key,
duke@435 240 class_loader,
duke@435 241 protection_domain,
duke@435 242 CHECK_NULL);
duke@435 243 if (k != NULL) {
duke@435 244 k = Klass::cast(k)->array_klass(dimension, CHECK_NULL);
duke@435 245 }
duke@435 246 } else {
duke@435 247 k = Universe::typeArrayKlassObj(t);
duke@435 248 k = typeArrayKlass::cast(k)->array_klass(dimension, CHECK_NULL);
duke@435 249 }
duke@435 250 return k;
duke@435 251 }
duke@435 252
duke@435 253
duke@435 254 // Must be called for any super-class or super-interface resolution
duke@435 255 // during class definition to allow class circularity checking
duke@435 256 // super-interface callers:
duke@435 257 // parse_interfaces - for defineClass & jvmtiRedefineClasses
duke@435 258 // super-class callers:
duke@435 259 // ClassFileParser - for defineClass & jvmtiRedefineClasses
duke@435 260 // load_shared_class - while loading a class from shared archive
duke@435 261 // resolve_instance_class_or_fail:
duke@435 262 // when resolving a class that has an existing placeholder with
duke@435 263 // a saved superclass [i.e. a defineClass is currently in progress]
duke@435 264 // if another thread is trying to resolve the class, it must do
duke@435 265 // super-class checks on its own thread to catch class circularity
duke@435 266 // This last call is critical in class circularity checking for cases
duke@435 267 // where classloading is delegated to different threads and the
duke@435 268 // classloader lock is released.
duke@435 269 // Take the case: Base->Super->Base
duke@435 270 // 1. If thread T1 tries to do a defineClass of class Base
duke@435 271 // resolve_super_or_fail creates placeholder: T1, Base (super Super)
duke@435 272 // 2. resolve_instance_class_or_null does not find SD or placeholder for Super
duke@435 273 // so it tries to load Super
duke@435 274 // 3. If we load the class internally, or user classloader uses same thread
duke@435 275 // loadClassFromxxx or defineClass via parseClassFile Super ...
duke@435 276 // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
duke@435 277 // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
duke@435 278 // 3.4 calls resolve_super_or_fail Base
duke@435 279 // 3.5 finds T1,Base -> throws class circularity
duke@435 280 //OR 4. If T2 tries to resolve Super via defineClass Super ...
duke@435 281 // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
duke@435 282 // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
duke@435 283 // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
duke@435 284 // 4.4 finds T2, Super -> throws class circularity
duke@435 285 // Must be called, even if superclass is null, since this is
duke@435 286 // where the placeholder entry is created which claims this
duke@435 287 // thread is loading this class/classloader.
duke@435 288 klassOop SystemDictionary::resolve_super_or_fail(symbolHandle child_name,
duke@435 289 symbolHandle class_name,
duke@435 290 Handle class_loader,
duke@435 291 Handle protection_domain,
duke@435 292 bool is_superclass,
duke@435 293 TRAPS) {
duke@435 294
duke@435 295 // Double-check, if child class is already loaded, just return super-class,interface
duke@435 296 // Don't add a placedholder if already loaded, i.e. already in system dictionary
duke@435 297 // Make sure there's a placeholder for the *child* before resolving.
duke@435 298 // Used as a claim that this thread is currently loading superclass/classloader
duke@435 299 // Used here for ClassCircularity checks and also for heap verification
duke@435 300 // (every instanceKlass in the heap needs to be in the system dictionary
duke@435 301 // or have a placeholder).
duke@435 302 // Must check ClassCircularity before checking if super class is already loaded
duke@435 303 //
duke@435 304 // We might not already have a placeholder if this child_name was
duke@435 305 // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
duke@435 306 // the name of the class might not be known until the stream is actually
duke@435 307 // parsed.
duke@435 308 // Bugs 4643874, 4715493
duke@435 309 // compute_hash can have a safepoint
duke@435 310
duke@435 311 unsigned int d_hash = dictionary()->compute_hash(child_name, class_loader);
duke@435 312 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 313 unsigned int p_hash = placeholders()->compute_hash(child_name, class_loader);
duke@435 314 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 315 // can't throw error holding a lock
duke@435 316 bool child_already_loaded = false;
duke@435 317 bool throw_circularity_error = false;
duke@435 318 {
duke@435 319 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 320 klassOop childk = find_class(d_index, d_hash, child_name, class_loader);
duke@435 321 klassOop quicksuperk;
duke@435 322 // to support // loading: if child done loading, just return superclass
duke@435 323 // if class_name, & class_loader don't match:
duke@435 324 // if initial define, SD update will give LinkageError
duke@435 325 // if redefine: compare_class_versions will give HIERARCHY_CHANGED
duke@435 326 // so we don't throw an exception here.
duke@435 327 // see: nsk redefclass014 & java.lang.instrument Instrument032
duke@435 328 if ((childk != NULL ) && (is_superclass) &&
duke@435 329 ((quicksuperk = instanceKlass::cast(childk)->super()) != NULL) &&
duke@435 330
duke@435 331 ((Klass::cast(quicksuperk)->name() == class_name()) &&
duke@435 332 (Klass::cast(quicksuperk)->class_loader() == class_loader()))) {
duke@435 333 return quicksuperk;
duke@435 334 } else {
duke@435 335 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, class_loader);
duke@435 336 if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
duke@435 337 throw_circularity_error = true;
duke@435 338 }
duke@435 339
duke@435 340 // add placeholder entry even if error - callers will remove on error
duke@435 341 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, class_loader, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
duke@435 342 if (throw_circularity_error) {
duke@435 343 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER);
duke@435 344 }
duke@435 345 }
duke@435 346 }
duke@435 347 if (throw_circularity_error) {
duke@435 348 ResourceMark rm(THREAD);
duke@435 349 THROW_MSG_0(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
duke@435 350 }
duke@435 351
duke@435 352 // java.lang.Object should have been found above
duke@435 353 assert(class_name() != NULL, "null super class for resolving");
duke@435 354 // Resolve the super class or interface, check results on return
duke@435 355 klassOop superk = NULL;
duke@435 356 superk = SystemDictionary::resolve_or_null(class_name,
duke@435 357 class_loader,
duke@435 358 protection_domain,
duke@435 359 THREAD);
duke@435 360
duke@435 361 KlassHandle superk_h(THREAD, superk);
duke@435 362
duke@435 363 // Note: clean up of placeholders currently in callers of
duke@435 364 // resolve_super_or_fail - either at update_dictionary time
duke@435 365 // or on error
duke@435 366 {
duke@435 367 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 368 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, class_loader);
duke@435 369 if (probe != NULL) {
duke@435 370 probe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER);
duke@435 371 }
duke@435 372 }
duke@435 373 if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
duke@435 374 // can null superk
duke@435 375 superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, class_loader, protection_domain, true, superk_h, THREAD));
duke@435 376 }
duke@435 377
duke@435 378 return superk_h();
duke@435 379 }
duke@435 380
duke@435 381
duke@435 382 void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
duke@435 383 Handle class_loader,
duke@435 384 Handle protection_domain,
duke@435 385 TRAPS) {
duke@435 386 if(!has_checkPackageAccess()) return;
duke@435 387
duke@435 388 // Now we have to call back to java to check if the initating class has access
duke@435 389 JavaValue result(T_VOID);
duke@435 390 if (TraceProtectionDomainVerification) {
duke@435 391 // Print out trace information
duke@435 392 tty->print_cr("Checking package access");
duke@435 393 tty->print(" - class loader: "); class_loader()->print_value_on(tty); tty->cr();
duke@435 394 tty->print(" - protection domain: "); protection_domain()->print_value_on(tty); tty->cr();
duke@435 395 tty->print(" - loading: "); klass()->print_value_on(tty); tty->cr();
duke@435 396 }
duke@435 397
duke@435 398 assert(class_loader() != NULL, "should not have non-null protection domain for null classloader");
duke@435 399
duke@435 400 KlassHandle system_loader(THREAD, SystemDictionary::classloader_klass());
duke@435 401 JavaCalls::call_special(&result,
duke@435 402 class_loader,
duke@435 403 system_loader,
duke@435 404 vmSymbolHandles::checkPackageAccess_name(),
duke@435 405 vmSymbolHandles::class_protectiondomain_signature(),
duke@435 406 Handle(THREAD, klass->java_mirror()),
duke@435 407 protection_domain,
duke@435 408 THREAD);
duke@435 409
duke@435 410 if (TraceProtectionDomainVerification) {
duke@435 411 if (HAS_PENDING_EXCEPTION) {
duke@435 412 tty->print_cr(" -> DENIED !!!!!!!!!!!!!!!!!!!!!");
duke@435 413 } else {
duke@435 414 tty->print_cr(" -> granted");
duke@435 415 }
duke@435 416 tty->cr();
duke@435 417 }
duke@435 418
duke@435 419 if (HAS_PENDING_EXCEPTION) return;
duke@435 420
duke@435 421 // If no exception has been thrown, we have validated the protection domain
duke@435 422 // Insert the protection domain of the initiating class into the set.
duke@435 423 {
duke@435 424 // We recalculate the entry here -- we've called out to java since
duke@435 425 // the last time it was calculated.
duke@435 426 symbolHandle kn(THREAD, klass->name());
duke@435 427 unsigned int d_hash = dictionary()->compute_hash(kn, class_loader);
duke@435 428 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 429
duke@435 430 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 431 {
duke@435 432 // Note that we have an entry, and entries can be deleted only during GC,
duke@435 433 // so we cannot allow GC to occur while we're holding this entry.
duke@435 434
duke@435 435 // We're using a No_Safepoint_Verifier to catch any place where we
duke@435 436 // might potentially do a GC at all.
duke@435 437 // SystemDictionary::do_unloading() asserts that classes are only
duke@435 438 // unloaded at a safepoint.
duke@435 439 No_Safepoint_Verifier nosafepoint;
duke@435 440 dictionary()->add_protection_domain(d_index, d_hash, klass, class_loader,
duke@435 441 protection_domain, THREAD);
duke@435 442 }
duke@435 443 }
duke@435 444 }
duke@435 445
duke@435 446 // We only get here if this thread finds that another thread
duke@435 447 // has already claimed the placeholder token for the current operation,
duke@435 448 // but that other thread either never owned or gave up the
duke@435 449 // object lock
duke@435 450 // Waits on SystemDictionary_lock to indicate placeholder table updated
duke@435 451 // On return, caller must recheck placeholder table state
duke@435 452 //
duke@435 453 // We only get here if
duke@435 454 // 1) custom classLoader, i.e. not bootstrap classloader
duke@435 455 // 2) UnsyncloadClass not set
duke@435 456 // 3) custom classLoader has broken the class loader objectLock
duke@435 457 // so another thread got here in parallel
duke@435 458 //
duke@435 459 // lockObject must be held.
duke@435 460 // Complicated dance due to lock ordering:
duke@435 461 // Must first release the classloader object lock to
duke@435 462 // allow initial definer to complete the class definition
duke@435 463 // and to avoid deadlock
duke@435 464 // Reclaim classloader lock object with same original recursion count
duke@435 465 // Must release SystemDictionary_lock after notify, since
duke@435 466 // class loader lock must be claimed before SystemDictionary_lock
duke@435 467 // to prevent deadlocks
duke@435 468 //
duke@435 469 // The notify allows applications that did an untimed wait() on
duke@435 470 // the classloader object lock to not hang.
duke@435 471 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
duke@435 472 assert_lock_strong(SystemDictionary_lock);
duke@435 473
duke@435 474 bool calledholdinglock
duke@435 475 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
duke@435 476 assert(calledholdinglock,"must hold lock for notify");
duke@435 477 assert(!UnsyncloadClass, "unexpected double_lock_wait");
duke@435 478 ObjectSynchronizer::notifyall(lockObject, THREAD);
duke@435 479 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
duke@435 480 SystemDictionary_lock->wait();
duke@435 481 SystemDictionary_lock->unlock();
duke@435 482 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
duke@435 483 SystemDictionary_lock->lock();
duke@435 484 }
duke@435 485
duke@435 486 // If the class in is in the placeholder table, class loading is in progress
duke@435 487 // For cases where the application changes threads to load classes, it
duke@435 488 // is critical to ClassCircularity detection that we try loading
duke@435 489 // the superclass on the same thread internally, so we do parallel
duke@435 490 // super class loading here.
duke@435 491 // This also is critical in cases where the original thread gets stalled
duke@435 492 // even in non-circularity situations.
duke@435 493 // Note: only one thread can define the class, but multiple can resolve
duke@435 494 // Note: must call resolve_super_or_fail even if null super -
duke@435 495 // to force placeholder entry creation for this class
duke@435 496 // Caller must check for pending exception
duke@435 497 // Returns non-null klassOop if other thread has completed load
duke@435 498 // and we are done,
duke@435 499 // If return null klassOop and no pending exception, the caller must load the class
duke@435 500 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
duke@435 501 symbolHandle name, symbolHandle superclassname, Handle class_loader,
duke@435 502 Handle protection_domain, Handle lockObject, TRAPS) {
duke@435 503
duke@435 504 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
duke@435 505 unsigned int d_hash = dictionary()->compute_hash(name, class_loader);
duke@435 506 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 507 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
duke@435 508 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 509
duke@435 510 // superk is not used, resolve_super called for circularity check only
duke@435 511 // This code is reached in two situations. One if this thread
duke@435 512 // is loading the same class twice (e.g. ClassCircularity, or
duke@435 513 // java.lang.instrument).
duke@435 514 // The second is if another thread started the resolve_super first
duke@435 515 // and has not yet finished.
duke@435 516 // In both cases the original caller will clean up the placeholder
duke@435 517 // entry on error.
duke@435 518 klassOop superk = SystemDictionary::resolve_super_or_fail(name,
duke@435 519 superclassname,
duke@435 520 class_loader,
duke@435 521 protection_domain,
duke@435 522 true,
duke@435 523 CHECK_(nh));
duke@435 524 // We don't redefine the class, so we just need to clean up if there
duke@435 525 // was not an error (don't want to modify any system dictionary
duke@435 526 // data structures).
duke@435 527 {
duke@435 528 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 529 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
duke@435 530 SystemDictionary_lock->notify_all();
duke@435 531 }
duke@435 532
duke@435 533 // UnsyncloadClass does NOT wait for parallel superclass loads to complete
duke@435 534 // Bootstrap classloader does wait for parallel superclass loads
duke@435 535 if (UnsyncloadClass) {
duke@435 536 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 537 // Check if classloading completed while we were loading superclass or waiting
duke@435 538 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 539 if (check != NULL) {
duke@435 540 // Klass is already loaded, so just return it
duke@435 541 return(instanceKlassHandle(THREAD, check));
duke@435 542 } else {
duke@435 543 return nh;
duke@435 544 }
duke@435 545 }
duke@435 546
duke@435 547 // must loop to both handle other placeholder updates
duke@435 548 // and spurious notifications
duke@435 549 bool super_load_in_progress = true;
duke@435 550 PlaceholderEntry* placeholder;
duke@435 551 while (super_load_in_progress) {
duke@435 552 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 553 // Check if classloading completed while we were loading superclass or waiting
duke@435 554 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 555 if (check != NULL) {
duke@435 556 // Klass is already loaded, so just return it
duke@435 557 return(instanceKlassHandle(THREAD, check));
duke@435 558 } else {
duke@435 559 placeholder = placeholders()->get_entry(p_index, p_hash, name, class_loader);
duke@435 560 if (placeholder && placeholder->super_load_in_progress() ){
duke@435 561 // Before UnsyncloadClass:
duke@435 562 // We only get here if the application has released the
duke@435 563 // classloader lock when another thread was in the middle of loading a
duke@435 564 // superclass/superinterface for this class, and now
duke@435 565 // this thread is also trying to load this class.
duke@435 566 // To minimize surprises, the first thread that started to
duke@435 567 // load a class should be the one to complete the loading
duke@435 568 // with the classfile it initially expected.
duke@435 569 // This logic has the current thread wait once it has done
duke@435 570 // all the superclass/superinterface loading it can, until
duke@435 571 // the original thread completes the class loading or fails
duke@435 572 // If it completes we will use the resulting instanceKlass
duke@435 573 // which we will find below in the systemDictionary.
duke@435 574 // We also get here for parallel bootstrap classloader
duke@435 575 if (class_loader.is_null()) {
duke@435 576 SystemDictionary_lock->wait();
duke@435 577 } else {
duke@435 578 double_lock_wait(lockObject, THREAD);
duke@435 579 }
duke@435 580 } else {
duke@435 581 // If not in SD and not in PH, other thread's load must have failed
duke@435 582 super_load_in_progress = false;
duke@435 583 }
duke@435 584 }
duke@435 585 }
duke@435 586 return (nh);
duke@435 587 }
duke@435 588
duke@435 589
duke@435 590 klassOop SystemDictionary::resolve_instance_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS) {
duke@435 591 assert(class_name.not_null() && !FieldType::is_array(class_name()), "invalid class name");
duke@435 592 // First check to see if we should remove wrapping L and ;
duke@435 593 symbolHandle name;
duke@435 594 if (FieldType::is_obj(class_name())) {
duke@435 595 ResourceMark rm(THREAD);
duke@435 596 // Ignore wrapping L and ;.
duke@435 597 name = oopFactory::new_symbol_handle(class_name()->as_C_string() + 1, class_name()->utf8_length() - 2, CHECK_NULL);
duke@435 598 } else {
duke@435 599 name = class_name;
duke@435 600 }
duke@435 601
duke@435 602 // UseNewReflection
duke@435 603 // Fix for 4474172; see evaluation for more details
duke@435 604 class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
duke@435 605
duke@435 606 // Do lookup to see if class already exist and the protection domain
duke@435 607 // has the right access
duke@435 608 unsigned int d_hash = dictionary()->compute_hash(name, class_loader);
duke@435 609 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 610 klassOop probe = dictionary()->find(d_index, d_hash, name, class_loader,
duke@435 611 protection_domain, THREAD);
duke@435 612 if (probe != NULL) return probe;
duke@435 613
duke@435 614
duke@435 615 // Non-bootstrap class loaders will call out to class loader and
duke@435 616 // define via jvm/jni_DefineClass which will acquire the
duke@435 617 // class loader object lock to protect against multiple threads
duke@435 618 // defining the class in parallel by accident.
duke@435 619 // This lock must be acquired here so the waiter will find
duke@435 620 // any successful result in the SystemDictionary and not attempt
duke@435 621 // the define
duke@435 622 // Classloaders that support parallelism, e.g. bootstrap classloader,
duke@435 623 // or all classloaders with UnsyncloadClass do not acquire lock here
duke@435 624 bool DoObjectLock = true;
duke@435 625 if (UnsyncloadClass || (class_loader.is_null())) {
duke@435 626 DoObjectLock = false;
duke@435 627 }
duke@435 628
duke@435 629 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
duke@435 630 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 631
duke@435 632 // Class is not in SystemDictionary so we have to do loading.
duke@435 633 // Make sure we are synchronized on the class loader before we proceed
duke@435 634 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
duke@435 635 check_loader_lock_contention(lockObject, THREAD);
duke@435 636 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
duke@435 637
duke@435 638 // Check again (after locking) if class already exist in SystemDictionary
duke@435 639 bool class_has_been_loaded = false;
duke@435 640 bool super_load_in_progress = false;
duke@435 641 bool havesupername = false;
duke@435 642 instanceKlassHandle k;
duke@435 643 PlaceholderEntry* placeholder;
duke@435 644 symbolHandle superclassname;
duke@435 645
duke@435 646 {
duke@435 647 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 648 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 649 if (check != NULL) {
duke@435 650 // Klass is already loaded, so just return it
duke@435 651 class_has_been_loaded = true;
duke@435 652 k = instanceKlassHandle(THREAD, check);
duke@435 653 } else {
duke@435 654 placeholder = placeholders()->get_entry(p_index, p_hash, name, class_loader);
duke@435 655 if (placeholder && placeholder->super_load_in_progress()) {
duke@435 656 super_load_in_progress = true;
duke@435 657 if (placeholder->havesupername() == true) {
duke@435 658 superclassname = symbolHandle(THREAD, placeholder->supername());
duke@435 659 havesupername = true;
duke@435 660 }
duke@435 661 }
duke@435 662 }
duke@435 663 }
duke@435 664
duke@435 665 // If the class in is in the placeholder table, class loading is in progress
duke@435 666 if (super_load_in_progress && havesupername==true) {
duke@435 667 k = SystemDictionary::handle_parallel_super_load(name, superclassname,
duke@435 668 class_loader, protection_domain, lockObject, THREAD);
duke@435 669 if (HAS_PENDING_EXCEPTION) {
duke@435 670 return NULL;
duke@435 671 }
duke@435 672 if (!k.is_null()) {
duke@435 673 class_has_been_loaded = true;
duke@435 674 }
duke@435 675 }
duke@435 676
duke@435 677 if (!class_has_been_loaded) {
duke@435 678
duke@435 679 // add placeholder entry to record loading instance class
duke@435 680 // Five cases:
duke@435 681 // All cases need to prevent modifying bootclasssearchpath
duke@435 682 // in parallel with a classload of same classname
duke@435 683 // case 1. traditional classloaders that rely on the classloader object lock
duke@435 684 // - no other need for LOAD_INSTANCE
duke@435 685 // case 2. traditional classloaders that break the classloader object lock
duke@435 686 // as a deadlock workaround. Detection of this case requires that
duke@435 687 // this check is done while holding the classloader object lock,
duke@435 688 // and that lock is still held when calling classloader's loadClass.
duke@435 689 // For these classloaders, we ensure that the first requestor
duke@435 690 // completes the load and other requestors wait for completion.
duke@435 691 // case 3. UnsyncloadClass - don't use objectLocker
duke@435 692 // With this flag, we allow parallel classloading of a
duke@435 693 // class/classloader pair
duke@435 694 // case4. Bootstrap classloader - don't own objectLocker
duke@435 695 // This classloader supports parallelism at the classloader level,
duke@435 696 // but only allows a single load of a class/classloader pair.
duke@435 697 // No performance benefit and no deadlock issues.
duke@435 698 // case 5. Future: parallel user level classloaders - without objectLocker
duke@435 699 symbolHandle nullsymbolHandle;
duke@435 700 bool throw_circularity_error = false;
duke@435 701 {
duke@435 702 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 703 if (!UnsyncloadClass) {
duke@435 704 PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
duke@435 705 if (oldprobe) {
duke@435 706 // only need check_seen_thread once, not on each loop
duke@435 707 // 6341374 java/lang/Instrument with -Xcomp
duke@435 708 if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
duke@435 709 throw_circularity_error = true;
duke@435 710 } else {
duke@435 711 // case 1: traditional: should never see load_in_progress.
duke@435 712 while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
duke@435 713
duke@435 714 // case 4: bootstrap classloader: prevent futile classloading,
duke@435 715 // wait on first requestor
duke@435 716 if (class_loader.is_null()) {
duke@435 717 SystemDictionary_lock->wait();
duke@435 718 } else {
duke@435 719 // case 2: traditional with broken classloader lock. wait on first
duke@435 720 // requestor.
duke@435 721 double_lock_wait(lockObject, THREAD);
duke@435 722 }
duke@435 723 // Check if classloading completed while we were waiting
duke@435 724 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 725 if (check != NULL) {
duke@435 726 // Klass is already loaded, so just return it
duke@435 727 k = instanceKlassHandle(THREAD, check);
duke@435 728 class_has_been_loaded = true;
duke@435 729 }
duke@435 730 // check if other thread failed to load and cleaned up
duke@435 731 oldprobe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
duke@435 732 }
duke@435 733 }
duke@435 734 }
duke@435 735 }
duke@435 736 // All cases: add LOAD_INSTANCE
duke@435 737 // case 3: UnsyncloadClass: allow competing threads to try
duke@435 738 // LOAD_INSTANCE in parallel
duke@435 739 // add placeholder entry even if error - callers will remove on error
duke@435 740 if (!class_has_been_loaded) {
duke@435 741 PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, class_loader, PlaceholderTable::LOAD_INSTANCE, nullsymbolHandle, THREAD);
duke@435 742 if (throw_circularity_error) {
duke@435 743 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
duke@435 744 }
duke@435 745 // For class loaders that do not acquire the classloader object lock,
duke@435 746 // if they did not catch another thread holding LOAD_INSTANCE,
duke@435 747 // need a check analogous to the acquire ObjectLocker/find_class
duke@435 748 // i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
duke@435 749 // one final check if the load has already completed
duke@435 750 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 751 if (check != NULL) {
duke@435 752 // Klass is already loaded, so just return it
duke@435 753 k = instanceKlassHandle(THREAD, check);
duke@435 754 class_has_been_loaded = true;
duke@435 755 newprobe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
duke@435 756 }
duke@435 757 }
duke@435 758 }
duke@435 759 // must throw error outside of owning lock
duke@435 760 if (throw_circularity_error) {
duke@435 761 ResourceMark rm(THREAD);
duke@435 762 THROW_MSG_0(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
duke@435 763 }
duke@435 764
duke@435 765 if (!class_has_been_loaded) {
duke@435 766
duke@435 767 // Do actual loading
duke@435 768 k = load_instance_class(name, class_loader, THREAD);
duke@435 769
duke@435 770 // In custom class loaders, the usual findClass calls
duke@435 771 // findLoadedClass, which directly searches the SystemDictionary, then
duke@435 772 // defineClass. If these are not atomic with respect to other threads,
duke@435 773 // the findLoadedClass can fail, but the defineClass can get a
duke@435 774 // LinkageError:: duplicate class definition.
duke@435 775 // If they got a linkageError, check if a parallel class load succeeded.
duke@435 776 // If it did, then for bytecode resolution the specification requires
duke@435 777 // that we return the same result we did for the other thread, i.e. the
duke@435 778 // successfully loaded instanceKlass
duke@435 779 // Note: Class can not be unloaded as long as any classloader refs exist
duke@435 780 // Should not get here for classloaders that support parallelism
duke@435 781 // with the new cleaner mechanism, e.g. bootstrap classloader
duke@435 782 if (UnsyncloadClass || (class_loader.is_null())) {
duke@435 783 if (k.is_null() && HAS_PENDING_EXCEPTION
duke@435 784 && PENDING_EXCEPTION->is_a(SystemDictionary::linkageError_klass())) {
duke@435 785 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 786 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 787 if (check != NULL) {
duke@435 788 // Klass is already loaded, so just use it
duke@435 789 k = instanceKlassHandle(THREAD, check);
duke@435 790 CLEAR_PENDING_EXCEPTION;
duke@435 791 guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
duke@435 792 }
duke@435 793 }
duke@435 794 }
duke@435 795
duke@435 796 // clean up placeholder entries for success or error
duke@435 797 // This cleans up LOAD_INSTANCE entries
duke@435 798 // It also cleans up LOAD_SUPER entries on errors from
duke@435 799 // calling load_instance_class
duke@435 800 {
duke@435 801 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 802 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name, class_loader);
duke@435 803 if (probe != NULL) {
duke@435 804 probe->remove_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE);
duke@435 805 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
duke@435 806 SystemDictionary_lock->notify_all();
duke@435 807 }
duke@435 808 }
duke@435 809
duke@435 810 // If everything was OK (no exceptions, no null return value), and
duke@435 811 // class_loader is NOT the defining loader, do a little more bookkeeping.
duke@435 812 if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
duke@435 813 k->class_loader() != class_loader()) {
duke@435 814
duke@435 815 check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
duke@435 816
duke@435 817 // Need to check for a PENDING_EXCEPTION again; check_constraints
duke@435 818 // can throw and doesn't use the CHECK macro.
duke@435 819 if (!HAS_PENDING_EXCEPTION) {
duke@435 820 { // Grabbing the Compile_lock prevents systemDictionary updates
duke@435 821 // during compilations.
duke@435 822 MutexLocker mu(Compile_lock, THREAD);
duke@435 823 update_dictionary(d_index, d_hash, p_index, p_hash,
duke@435 824 k, class_loader, THREAD);
duke@435 825 }
duke@435 826 if (JvmtiExport::should_post_class_load()) {
duke@435 827 Thread *thread = THREAD;
duke@435 828 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
duke@435 829 JvmtiExport::post_class_load((JavaThread *) thread, k());
duke@435 830 }
duke@435 831 }
duke@435 832 }
duke@435 833 if (HAS_PENDING_EXCEPTION || k.is_null()) {
duke@435 834 // On error, clean up placeholders
duke@435 835 {
duke@435 836 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 837 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
duke@435 838 SystemDictionary_lock->notify_all();
duke@435 839 }
duke@435 840 return NULL;
duke@435 841 }
duke@435 842 }
duke@435 843 }
duke@435 844
duke@435 845 #ifdef ASSERT
duke@435 846 {
duke@435 847 Handle loader (THREAD, k->class_loader());
duke@435 848 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 849 oop kk = find_class_or_placeholder(name, loader);
duke@435 850 assert(kk == k(), "should be present in dictionary");
duke@435 851 }
duke@435 852 #endif
duke@435 853
duke@435 854 // return if the protection domain in NULL
duke@435 855 if (protection_domain() == NULL) return k();
duke@435 856
duke@435 857 // Check the protection domain has the right access
duke@435 858 {
duke@435 859 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 860 // Note that we have an entry, and entries can be deleted only during GC,
duke@435 861 // so we cannot allow GC to occur while we're holding this entry.
duke@435 862 // We're using a No_Safepoint_Verifier to catch any place where we
duke@435 863 // might potentially do a GC at all.
duke@435 864 // SystemDictionary::do_unloading() asserts that classes are only
duke@435 865 // unloaded at a safepoint.
duke@435 866 No_Safepoint_Verifier nosafepoint;
duke@435 867 if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
duke@435 868 class_loader,
duke@435 869 protection_domain)) {
duke@435 870 return k();
duke@435 871 }
duke@435 872 }
duke@435 873
duke@435 874 // Verify protection domain. If it fails an exception is thrown
duke@435 875 validate_protection_domain(k, class_loader, protection_domain, CHECK_(klassOop(NULL)));
duke@435 876
duke@435 877 return k();
duke@435 878 }
duke@435 879
duke@435 880
duke@435 881 // This routine does not lock the system dictionary.
duke@435 882 //
duke@435 883 // Since readers don't hold a lock, we must make sure that system
duke@435 884 // dictionary entries are only removed at a safepoint (when only one
duke@435 885 // thread is running), and are added to in a safe way (all links must
duke@435 886 // be updated in an MT-safe manner).
duke@435 887 //
duke@435 888 // Callers should be aware that an entry could be added just after
duke@435 889 // _dictionary->bucket(index) is read here, so the caller will not see
duke@435 890 // the new entry.
duke@435 891
duke@435 892 klassOop SystemDictionary::find(symbolHandle class_name,
duke@435 893 Handle class_loader,
duke@435 894 Handle protection_domain,
duke@435 895 TRAPS) {
duke@435 896
duke@435 897 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
duke@435 898 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 899
duke@435 900 {
duke@435 901 // Note that we have an entry, and entries can be deleted only during GC,
duke@435 902 // so we cannot allow GC to occur while we're holding this entry.
duke@435 903 // We're using a No_Safepoint_Verifier to catch any place where we
duke@435 904 // might potentially do a GC at all.
duke@435 905 // SystemDictionary::do_unloading() asserts that classes are only
duke@435 906 // unloaded at a safepoint.
duke@435 907 No_Safepoint_Verifier nosafepoint;
duke@435 908 return dictionary()->find(d_index, d_hash, class_name, class_loader,
duke@435 909 protection_domain, THREAD);
duke@435 910 }
duke@435 911 }
duke@435 912
duke@435 913
duke@435 914 // Look for a loaded instance or array klass by name. Do not do any loading.
duke@435 915 // return NULL in case of error.
duke@435 916 klassOop SystemDictionary::find_instance_or_array_klass(symbolHandle class_name,
duke@435 917 Handle class_loader,
duke@435 918 Handle protection_domain,
duke@435 919 TRAPS) {
duke@435 920 klassOop k = NULL;
duke@435 921 assert(class_name() != NULL, "class name must be non NULL");
duke@435 922 if (FieldType::is_array(class_name())) {
duke@435 923 // The name refers to an array. Parse the name.
duke@435 924 jint dimension;
duke@435 925 symbolOop object_key;
duke@435 926
duke@435 927 // dimension and object_key are assigned as a side-effect of this call
duke@435 928 BasicType t = FieldType::get_array_info(class_name(), &dimension,
duke@435 929 &object_key, CHECK_(NULL));
duke@435 930 if (t != T_OBJECT) {
duke@435 931 k = Universe::typeArrayKlassObj(t);
duke@435 932 } else {
duke@435 933 symbolHandle h_key(THREAD, object_key);
duke@435 934 k = SystemDictionary::find(h_key, class_loader, protection_domain, THREAD);
duke@435 935 }
duke@435 936 if (k != NULL) {
duke@435 937 k = Klass::cast(k)->array_klass_or_null(dimension);
duke@435 938 }
duke@435 939 } else {
duke@435 940 k = find(class_name, class_loader, protection_domain, THREAD);
duke@435 941 }
duke@435 942 return k;
duke@435 943 }
duke@435 944
duke@435 945 // Note: this method is much like resolve_from_stream, but
duke@435 946 // updates no supplemental data structures.
duke@435 947 // TODO consolidate the two methods with a helper routine?
duke@435 948 klassOop SystemDictionary::parse_stream(symbolHandle class_name,
duke@435 949 Handle class_loader,
duke@435 950 Handle protection_domain,
duke@435 951 ClassFileStream* st,
duke@435 952 TRAPS) {
duke@435 953 symbolHandle parsed_name;
duke@435 954
duke@435 955 // Parse the stream. Note that we do this even though this klass might
duke@435 956 // already be present in the SystemDictionary, otherwise we would not
duke@435 957 // throw potential ClassFormatErrors.
duke@435 958 //
duke@435 959 // Note: "name" is updated.
duke@435 960 // Further note: a placeholder will be added for this class when
duke@435 961 // super classes are loaded (resolve_super_or_fail). We expect this
duke@435 962 // to be called for all classes but java.lang.Object; and we preload
duke@435 963 // java.lang.Object through resolve_or_fail, not this path.
duke@435 964
duke@435 965 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
duke@435 966 class_loader,
duke@435 967 protection_domain,
duke@435 968 parsed_name,
duke@435 969 THREAD);
duke@435 970
duke@435 971
duke@435 972 // We don't redefine the class, so we just need to clean up whether there
duke@435 973 // was an error or not (don't want to modify any system dictionary
duke@435 974 // data structures).
duke@435 975 // Parsed name could be null if we threw an error before we got far
duke@435 976 // enough along to parse it -- in that case, there is nothing to clean up.
duke@435 977 if (!parsed_name.is_null()) {
duke@435 978 unsigned int p_hash = placeholders()->compute_hash(parsed_name,
duke@435 979 class_loader);
duke@435 980 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 981 {
duke@435 982 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 983 placeholders()->find_and_remove(p_index, p_hash, parsed_name, class_loader, THREAD);
duke@435 984 SystemDictionary_lock->notify_all();
duke@435 985 }
duke@435 986 }
duke@435 987
duke@435 988 return k();
duke@435 989 }
duke@435 990
duke@435 991 // Add a klass to the system from a stream (called by jni_DefineClass and
duke@435 992 // JVM_DefineClass).
duke@435 993 // Note: class_name can be NULL. In that case we do not know the name of
duke@435 994 // the class until we have parsed the stream.
duke@435 995
duke@435 996 klassOop SystemDictionary::resolve_from_stream(symbolHandle class_name,
duke@435 997 Handle class_loader,
duke@435 998 Handle protection_domain,
duke@435 999 ClassFileStream* st,
duke@435 1000 TRAPS) {
duke@435 1001
duke@435 1002 // Make sure we are synchronized on the class loader before we initiate
duke@435 1003 // loading.
duke@435 1004 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
duke@435 1005 check_loader_lock_contention(lockObject, THREAD);
duke@435 1006 ObjectLocker ol(lockObject, THREAD);
duke@435 1007
duke@435 1008 symbolHandle parsed_name;
duke@435 1009
duke@435 1010 // Parse the stream. Note that we do this even though this klass might
duke@435 1011 // already be present in the SystemDictionary, otherwise we would not
duke@435 1012 // throw potential ClassFormatErrors.
duke@435 1013 //
duke@435 1014 // Note: "name" is updated.
duke@435 1015 // Further note: a placeholder will be added for this class when
duke@435 1016 // super classes are loaded (resolve_super_or_fail). We expect this
duke@435 1017 // to be called for all classes but java.lang.Object; and we preload
duke@435 1018 // java.lang.Object through resolve_or_fail, not this path.
duke@435 1019
duke@435 1020 instanceKlassHandle k = ClassFileParser(st).parseClassFile(class_name,
duke@435 1021 class_loader,
duke@435 1022 protection_domain,
duke@435 1023 parsed_name,
duke@435 1024 THREAD);
duke@435 1025
duke@435 1026 const char* pkg = "java/";
duke@435 1027 if (!HAS_PENDING_EXCEPTION &&
duke@435 1028 !class_loader.is_null() &&
duke@435 1029 !parsed_name.is_null() &&
duke@435 1030 !strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
duke@435 1031 // It is illegal to define classes in the "java." package from
duke@435 1032 // JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
duke@435 1033 ResourceMark rm(THREAD);
duke@435 1034 char* name = parsed_name->as_C_string();
duke@435 1035 char* index = strrchr(name, '/');
duke@435 1036 *index = '\0'; // chop to just the package name
duke@435 1037 while ((index = strchr(name, '/')) != NULL) {
duke@435 1038 *index = '.'; // replace '/' with '.' in package name
duke@435 1039 }
duke@435 1040 const char* fmt = "Prohibited package name: %s";
duke@435 1041 size_t len = strlen(fmt) + strlen(name);
duke@435 1042 char* message = NEW_RESOURCE_ARRAY(char, len);
duke@435 1043 jio_snprintf(message, len, fmt, name);
duke@435 1044 Exceptions::_throw_msg(THREAD_AND_LOCATION,
duke@435 1045 vmSymbols::java_lang_SecurityException(), message);
duke@435 1046 }
duke@435 1047
duke@435 1048 if (!HAS_PENDING_EXCEPTION) {
duke@435 1049 assert(!parsed_name.is_null(), "Sanity");
duke@435 1050 assert(class_name.is_null() || class_name() == parsed_name(),
duke@435 1051 "name mismatch");
duke@435 1052 // Verification prevents us from creating names with dots in them, this
duke@435 1053 // asserts that that's the case.
duke@435 1054 assert(is_internal_format(parsed_name),
duke@435 1055 "external class name format used internally");
duke@435 1056
duke@435 1057 // Add class just loaded
duke@435 1058 define_instance_class(k, THREAD);
duke@435 1059 }
duke@435 1060
duke@435 1061 // If parsing the class file or define_instance_class failed, we
duke@435 1062 // need to remove the placeholder added on our behalf. But we
duke@435 1063 // must make sure parsed_name is valid first (it won't be if we had
duke@435 1064 // a format error before the class was parsed far enough to
duke@435 1065 // find the name).
duke@435 1066 if (HAS_PENDING_EXCEPTION && !parsed_name.is_null()) {
duke@435 1067 unsigned int p_hash = placeholders()->compute_hash(parsed_name,
duke@435 1068 class_loader);
duke@435 1069 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 1070 {
duke@435 1071 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 1072 placeholders()->find_and_remove(p_index, p_hash, parsed_name, class_loader, THREAD);
duke@435 1073 SystemDictionary_lock->notify_all();
duke@435 1074 }
duke@435 1075 return NULL;
duke@435 1076 }
duke@435 1077
duke@435 1078 // Make sure that we didn't leave a place holder in the
duke@435 1079 // SystemDictionary; this is only done on success
duke@435 1080 debug_only( {
duke@435 1081 if (!HAS_PENDING_EXCEPTION) {
duke@435 1082 assert(!parsed_name.is_null(), "parsed_name is still null?");
duke@435 1083 symbolHandle h_name (THREAD, k->name());
duke@435 1084 Handle h_loader (THREAD, k->class_loader());
duke@435 1085
duke@435 1086 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 1087
duke@435 1088 oop check = find_class_or_placeholder(parsed_name, class_loader);
duke@435 1089 assert(check == k(), "should be present in the dictionary");
duke@435 1090
duke@435 1091 oop check2 = find_class_or_placeholder(h_name, h_loader);
duke@435 1092 assert(check == check2, "name inconsistancy in SystemDictionary");
duke@435 1093 }
duke@435 1094 } );
duke@435 1095
duke@435 1096 return k();
duke@435 1097 }
duke@435 1098
duke@435 1099
duke@435 1100 void SystemDictionary::set_shared_dictionary(HashtableBucket* t, int length,
duke@435 1101 int number_of_entries) {
duke@435 1102 assert(length == _nof_buckets * sizeof(HashtableBucket),
duke@435 1103 "bad shared dictionary size.");
duke@435 1104 _shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
duke@435 1105 }
duke@435 1106
duke@435 1107
duke@435 1108 // If there is a shared dictionary, then find the entry for the
duke@435 1109 // given shared system class, if any.
duke@435 1110
duke@435 1111 klassOop SystemDictionary::find_shared_class(symbolHandle class_name) {
duke@435 1112 if (shared_dictionary() != NULL) {
duke@435 1113 unsigned int d_hash = dictionary()->compute_hash(class_name, Handle());
duke@435 1114 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 1115 return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
duke@435 1116 } else {
duke@435 1117 return NULL;
duke@435 1118 }
duke@435 1119 }
duke@435 1120
duke@435 1121
duke@435 1122 // Load a class from the shared spaces (found through the shared system
duke@435 1123 // dictionary). Force the superclass and all interfaces to be loaded.
duke@435 1124 // Update the class definition to include sibling classes and no
duke@435 1125 // subclasses (yet). [Classes in the shared space are not part of the
duke@435 1126 // object hierarchy until loaded.]
duke@435 1127
duke@435 1128 instanceKlassHandle SystemDictionary::load_shared_class(
duke@435 1129 symbolHandle class_name, Handle class_loader, TRAPS) {
duke@435 1130 instanceKlassHandle ik (THREAD, find_shared_class(class_name));
duke@435 1131 return load_shared_class(ik, class_loader, THREAD);
duke@435 1132 }
duke@435 1133
duke@435 1134 // Note well! Changes to this method may affect oop access order
duke@435 1135 // in the shared archive. Please take care to not make changes that
duke@435 1136 // adversely affect cold start time by changing the oop access order
duke@435 1137 // that is specified in dump.cpp MarkAndMoveOrderedReadOnly and
duke@435 1138 // MarkAndMoveOrderedReadWrite closures.
duke@435 1139 instanceKlassHandle SystemDictionary::load_shared_class(
duke@435 1140 instanceKlassHandle ik, Handle class_loader, TRAPS) {
duke@435 1141 assert(class_loader.is_null(), "non-null classloader for shared class?");
duke@435 1142 if (ik.not_null()) {
duke@435 1143 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
duke@435 1144 symbolHandle class_name(THREAD, ik->name());
duke@435 1145
duke@435 1146 // Found the class, now load the superclass and interfaces. If they
duke@435 1147 // are shared, add them to the main system dictionary and reset
duke@435 1148 // their hierarchy references (supers, subs, and interfaces).
duke@435 1149
duke@435 1150 if (ik->super() != NULL) {
duke@435 1151 symbolHandle cn(THREAD, ik->super()->klass_part()->name());
duke@435 1152 resolve_super_or_fail(class_name, cn,
duke@435 1153 class_loader, Handle(), true, CHECK_(nh));
duke@435 1154 }
duke@435 1155
duke@435 1156 objArrayHandle interfaces (THREAD, ik->local_interfaces());
duke@435 1157 int num_interfaces = interfaces->length();
duke@435 1158 for (int index = 0; index < num_interfaces; index++) {
duke@435 1159 klassOop k = klassOop(interfaces->obj_at(index));
duke@435 1160
duke@435 1161 // Note: can not use instanceKlass::cast here because
duke@435 1162 // interfaces' instanceKlass's C++ vtbls haven't been
duke@435 1163 // reinitialized yet (they will be once the interface classes
duke@435 1164 // are loaded)
duke@435 1165 symbolHandle name (THREAD, k->klass_part()->name());
duke@435 1166 resolve_super_or_fail(class_name, name, class_loader, Handle(), false, CHECK_(nh));
duke@435 1167 }
duke@435 1168
duke@435 1169 // Adjust methods to recover missing data. They need addresses for
duke@435 1170 // interpreter entry points and their default native method address
duke@435 1171 // must be reset.
duke@435 1172
duke@435 1173 // Updating methods must be done under a lock so multiple
duke@435 1174 // threads don't update these in parallel
duke@435 1175 // Shared classes are all currently loaded by the bootstrap
duke@435 1176 // classloader, so this will never cause a deadlock on
duke@435 1177 // a custom class loader lock.
duke@435 1178
duke@435 1179 {
duke@435 1180 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
duke@435 1181 check_loader_lock_contention(lockObject, THREAD);
duke@435 1182 ObjectLocker ol(lockObject, THREAD, true);
duke@435 1183
duke@435 1184 objArrayHandle methods (THREAD, ik->methods());
duke@435 1185 int num_methods = methods->length();
duke@435 1186 for (int index2 = 0; index2 < num_methods; ++index2) {
duke@435 1187 methodHandle m(THREAD, methodOop(methods->obj_at(index2)));
duke@435 1188 m()->link_method(m, CHECK_(nh));
duke@435 1189 }
duke@435 1190 }
duke@435 1191
duke@435 1192 if (TraceClassLoading) {
duke@435 1193 ResourceMark rm;
duke@435 1194 tty->print("[Loaded %s", ik->external_name());
duke@435 1195 tty->print(" from shared objects file");
duke@435 1196 tty->print_cr("]");
duke@435 1197 }
duke@435 1198 // notify a class loaded from shared object
duke@435 1199 ClassLoadingService::notify_class_loaded(instanceKlass::cast(ik()),
duke@435 1200 true /* shared class */);
duke@435 1201 }
duke@435 1202 return ik;
duke@435 1203 }
duke@435 1204
duke@435 1205 #ifdef KERNEL
duke@435 1206 // Some classes on the bootstrap class path haven't been installed on the
duke@435 1207 // system yet. Call the DownloadManager method to make them appear in the
duke@435 1208 // bootstrap class path and try again to load the named class.
duke@435 1209 // Note that with delegation class loaders all classes in another loader will
duke@435 1210 // first try to call this so it'd better be fast!!
duke@435 1211 static instanceKlassHandle download_and_retry_class_load(
duke@435 1212 symbolHandle class_name,
duke@435 1213 TRAPS) {
duke@435 1214
duke@435 1215 klassOop dlm = SystemDictionary::sun_jkernel_DownloadManager_klass();
duke@435 1216 instanceKlassHandle nk;
duke@435 1217
duke@435 1218 // If download manager class isn't loaded just return.
duke@435 1219 if (dlm == NULL) return nk;
duke@435 1220
duke@435 1221 { HandleMark hm(THREAD);
duke@435 1222 ResourceMark rm(THREAD);
duke@435 1223 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nk));
duke@435 1224 Handle class_string = java_lang_String::externalize_classname(s, CHECK_(nk));
duke@435 1225
duke@435 1226 // return value
duke@435 1227 JavaValue result(T_OBJECT);
duke@435 1228
duke@435 1229 // Call the DownloadManager. We assume that it has a lock because
duke@435 1230 // multiple classes could be not found and downloaded at the same time.
duke@435 1231 // class sun.misc.DownloadManager;
duke@435 1232 // public static String getBootClassPathEntryForClass(String className);
duke@435 1233 JavaCalls::call_static(&result,
duke@435 1234 KlassHandle(THREAD, dlm),
duke@435 1235 vmSymbolHandles::getBootClassPathEntryForClass_name(),
duke@435 1236 vmSymbolHandles::string_string_signature(),
duke@435 1237 class_string,
duke@435 1238 CHECK_(nk));
duke@435 1239
duke@435 1240 // Get result.string and add to bootclasspath
duke@435 1241 assert(result.get_type() == T_OBJECT, "just checking");
duke@435 1242 oop obj = (oop) result.get_jobject();
duke@435 1243 if (obj == NULL) { return nk; }
duke@435 1244
coleenp@457 1245 Handle h_obj(THREAD, obj);
coleenp@457 1246 char* new_class_name = java_lang_String::as_platform_dependent_str(h_obj,
coleenp@457 1247 CHECK_(nk));
duke@435 1248
duke@435 1249 // lock the loader
duke@435 1250 // we use this lock because JVMTI does.
duke@435 1251 Handle loader_lock(THREAD, SystemDictionary::system_loader_lock());
duke@435 1252
duke@435 1253 ObjectLocker ol(loader_lock, THREAD);
duke@435 1254 // add the file to the bootclasspath
duke@435 1255 ClassLoader::update_class_path_entry_list(new_class_name, true);
duke@435 1256 } // end HandleMark
duke@435 1257
duke@435 1258 if (TraceClassLoading) {
duke@435 1259 ClassLoader::print_bootclasspath();
duke@435 1260 }
duke@435 1261 return ClassLoader::load_classfile(class_name, CHECK_(nk));
duke@435 1262 }
duke@435 1263 #endif // KERNEL
duke@435 1264
duke@435 1265
duke@435 1266 instanceKlassHandle SystemDictionary::load_instance_class(symbolHandle class_name, Handle class_loader, TRAPS) {
duke@435 1267 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
duke@435 1268 if (class_loader.is_null()) {
duke@435 1269 // Search the shared system dictionary for classes preloaded into the
duke@435 1270 // shared spaces.
duke@435 1271 instanceKlassHandle k;
duke@435 1272 k = load_shared_class(class_name, class_loader, THREAD);
duke@435 1273
duke@435 1274 if (k.is_null()) {
duke@435 1275 // Use VM class loader
duke@435 1276 k = ClassLoader::load_classfile(class_name, CHECK_(nh));
duke@435 1277 }
duke@435 1278
duke@435 1279 #ifdef KERNEL
duke@435 1280 // If the VM class loader has failed to load the class, call the
duke@435 1281 // DownloadManager class to make it magically appear on the classpath
duke@435 1282 // and try again. This is only configured with the Kernel VM.
duke@435 1283 if (k.is_null()) {
duke@435 1284 k = download_and_retry_class_load(class_name, CHECK_(nh));
duke@435 1285 }
duke@435 1286 #endif // KERNEL
duke@435 1287
duke@435 1288 // find_or_define_instance_class may return a different k
duke@435 1289 if (!k.is_null()) {
duke@435 1290 k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
duke@435 1291 }
duke@435 1292 return k;
duke@435 1293 } else {
duke@435 1294 // Use user specified class loader to load class. Call loadClass operation on class_loader.
duke@435 1295 ResourceMark rm(THREAD);
duke@435 1296
duke@435 1297 Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
duke@435 1298 // Translate to external class name format, i.e., convert '/' chars to '.'
duke@435 1299 Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
duke@435 1300
duke@435 1301 JavaValue result(T_OBJECT);
duke@435 1302
duke@435 1303 KlassHandle spec_klass (THREAD, SystemDictionary::classloader_klass());
duke@435 1304
duke@435 1305 // UnsyncloadClass option means don't synchronize loadClass() calls.
duke@435 1306 // loadClassInternal() is synchronized and public loadClass(String) is not.
duke@435 1307 // This flag is for diagnostic purposes only. It is risky to call
duke@435 1308 // custom class loaders without synchronization.
duke@435 1309 // WARNING If a custom class loader does NOT synchronizer findClass, or callers of
duke@435 1310 // findClass, this flag risks unexpected timing bugs in the field.
duke@435 1311 // Do NOT assume this will be supported in future releases.
duke@435 1312 if (!UnsyncloadClass && has_loadClassInternal()) {
duke@435 1313 JavaCalls::call_special(&result,
duke@435 1314 class_loader,
duke@435 1315 spec_klass,
duke@435 1316 vmSymbolHandles::loadClassInternal_name(),
duke@435 1317 vmSymbolHandles::string_class_signature(),
duke@435 1318 string,
duke@435 1319 CHECK_(nh));
duke@435 1320 } else {
duke@435 1321 JavaCalls::call_virtual(&result,
duke@435 1322 class_loader,
duke@435 1323 spec_klass,
duke@435 1324 vmSymbolHandles::loadClass_name(),
duke@435 1325 vmSymbolHandles::string_class_signature(),
duke@435 1326 string,
duke@435 1327 CHECK_(nh));
duke@435 1328 }
duke@435 1329
duke@435 1330 assert(result.get_type() == T_OBJECT, "just checking");
duke@435 1331 oop obj = (oop) result.get_jobject();
duke@435 1332
duke@435 1333 // Primitive classes return null since forName() can not be
duke@435 1334 // used to obtain any of the Class objects representing primitives or void
duke@435 1335 if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
duke@435 1336 instanceKlassHandle k =
duke@435 1337 instanceKlassHandle(THREAD, java_lang_Class::as_klassOop(obj));
duke@435 1338 // For user defined Java class loaders, check that the name returned is
duke@435 1339 // the same as that requested. This check is done for the bootstrap
duke@435 1340 // loader when parsing the class file.
duke@435 1341 if (class_name() == k->name()) {
duke@435 1342 return k;
duke@435 1343 }
duke@435 1344 }
duke@435 1345 // Class is not found or has the wrong name, return NULL
duke@435 1346 return nh;
duke@435 1347 }
duke@435 1348 }
duke@435 1349
duke@435 1350 void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
duke@435 1351
duke@435 1352 Handle class_loader_h(THREAD, k->class_loader());
duke@435 1353
duke@435 1354 // for bootstrap classloader don't acquire lock
duke@435 1355 if (!class_loader_h.is_null()) {
duke@435 1356 assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
duke@435 1357 compute_loader_lock_object(class_loader_h, THREAD)),
duke@435 1358 "define called without lock");
duke@435 1359 }
duke@435 1360
duke@435 1361
duke@435 1362 // Check class-loading constraints. Throw exception if violation is detected.
duke@435 1363 // Grabs and releases SystemDictionary_lock
duke@435 1364 // The check_constraints/find_class call and update_dictionary sequence
duke@435 1365 // must be "atomic" for a specific class/classloader pair so we never
duke@435 1366 // define two different instanceKlasses for that class/classloader pair.
duke@435 1367 // Existing classloaders will call define_instance_class with the
duke@435 1368 // classloader lock held
duke@435 1369 // Parallel classloaders will call find_or_define_instance_class
duke@435 1370 // which will require a token to perform the define class
duke@435 1371 symbolHandle name_h(THREAD, k->name());
duke@435 1372 unsigned int d_hash = dictionary()->compute_hash(name_h, class_loader_h);
duke@435 1373 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 1374 check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
duke@435 1375
duke@435 1376 // Register class just loaded with class loader (placed in Vector)
duke@435 1377 // Note we do this before updating the dictionary, as this can
duke@435 1378 // fail with an OutOfMemoryError (if it does, we will *not* put this
duke@435 1379 // class in the dictionary and will not update the class hierarchy).
duke@435 1380 if (k->class_loader() != NULL) {
duke@435 1381 methodHandle m(THREAD, Universe::loader_addClass_method());
duke@435 1382 JavaValue result(T_VOID);
duke@435 1383 JavaCallArguments args(class_loader_h);
duke@435 1384 args.push_oop(Handle(THREAD, k->java_mirror()));
duke@435 1385 JavaCalls::call(&result, m, &args, CHECK);
duke@435 1386 }
duke@435 1387
duke@435 1388 // Add the new class. We need recompile lock during update of CHA.
duke@435 1389 {
duke@435 1390 unsigned int p_hash = placeholders()->compute_hash(name_h, class_loader_h);
duke@435 1391 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 1392
duke@435 1393 MutexLocker mu_r(Compile_lock, THREAD);
duke@435 1394
duke@435 1395 // Add to class hierarchy, initialize vtables, and do possible
duke@435 1396 // deoptimizations.
duke@435 1397 add_to_hierarchy(k, CHECK); // No exception, but can block
duke@435 1398
duke@435 1399 // Add to systemDictionary - so other classes can see it.
duke@435 1400 // Grabs and releases SystemDictionary_lock
duke@435 1401 update_dictionary(d_index, d_hash, p_index, p_hash,
duke@435 1402 k, class_loader_h, THREAD);
duke@435 1403 }
duke@435 1404 k->eager_initialize(THREAD);
duke@435 1405
duke@435 1406 // notify jvmti
duke@435 1407 if (JvmtiExport::should_post_class_load()) {
duke@435 1408 assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
duke@435 1409 JvmtiExport::post_class_load((JavaThread *) THREAD, k());
duke@435 1410
duke@435 1411 }
duke@435 1412 }
duke@435 1413
duke@435 1414 // Support parallel classloading
duke@435 1415 // Initial implementation for bootstrap classloader
duke@435 1416 // For future:
duke@435 1417 // For custom class loaders that support parallel classloading,
duke@435 1418 // in case they do not synchronize around
duke@435 1419 // FindLoadedClass/DefineClass calls, we check for parallel
duke@435 1420 // loading for them, wait if a defineClass is in progress
duke@435 1421 // and return the initial requestor's results
duke@435 1422 // For better performance, the class loaders should synchronize
duke@435 1423 // findClass(), i.e. FindLoadedClass/DefineClass or they
duke@435 1424 // potentially waste time reading and parsing the bytestream.
duke@435 1425 // Note: VM callers should ensure consistency of k/class_name,class_loader
duke@435 1426 instanceKlassHandle SystemDictionary::find_or_define_instance_class(symbolHandle class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
duke@435 1427
duke@435 1428 instanceKlassHandle nh = instanceKlassHandle(); // null Handle
duke@435 1429
duke@435 1430 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
duke@435 1431 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 1432
duke@435 1433 // Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
duke@435 1434 unsigned int p_hash = placeholders()->compute_hash(class_name, class_loader);
duke@435 1435 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 1436 PlaceholderEntry* probe;
duke@435 1437
duke@435 1438 {
duke@435 1439 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 1440 // First check if class already defined
duke@435 1441 klassOop check = find_class(d_index, d_hash, class_name, class_loader);
duke@435 1442 if (check != NULL) {
duke@435 1443 return(instanceKlassHandle(THREAD, check));
duke@435 1444 }
duke@435 1445
duke@435 1446 // Acquire define token for this class/classloader
duke@435 1447 symbolHandle nullsymbolHandle;
duke@435 1448 probe = placeholders()->find_and_add(p_index, p_hash, class_name, class_loader, PlaceholderTable::DEFINE_CLASS, nullsymbolHandle, THREAD);
duke@435 1449 // Check if another thread defining in parallel
duke@435 1450 if (probe->definer() == NULL) {
duke@435 1451 // Thread will define the class
duke@435 1452 probe->set_definer(THREAD);
duke@435 1453 } else {
duke@435 1454 // Wait for defining thread to finish and return results
duke@435 1455 while (probe->definer() != NULL) {
duke@435 1456 SystemDictionary_lock->wait();
duke@435 1457 }
duke@435 1458 if (probe->instanceKlass() != NULL) {
duke@435 1459 probe->remove_seen_thread(THREAD, PlaceholderTable::DEFINE_CLASS);
duke@435 1460 return(instanceKlassHandle(THREAD, probe->instanceKlass()));
duke@435 1461 } else {
duke@435 1462 // If definer had an error, try again as any new thread would
duke@435 1463 probe->set_definer(THREAD);
duke@435 1464 #ifdef ASSERT
duke@435 1465 klassOop check = find_class(d_index, d_hash, class_name, class_loader);
duke@435 1466 assert(check == NULL, "definer missed recording success");
duke@435 1467 #endif
duke@435 1468 }
duke@435 1469 }
duke@435 1470 }
duke@435 1471
duke@435 1472 define_instance_class(k, THREAD);
duke@435 1473
duke@435 1474 Handle linkage_exception = Handle(); // null handle
duke@435 1475
duke@435 1476 // definer must notify any waiting threads
duke@435 1477 {
duke@435 1478 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 1479 PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, class_name, class_loader);
duke@435 1480 assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
duke@435 1481 if (probe != NULL) {
duke@435 1482 if (HAS_PENDING_EXCEPTION) {
duke@435 1483 linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
duke@435 1484 CLEAR_PENDING_EXCEPTION;
duke@435 1485 } else {
duke@435 1486 probe->set_instanceKlass(k());
duke@435 1487 }
duke@435 1488 probe->set_definer(NULL);
duke@435 1489 probe->remove_seen_thread(THREAD, PlaceholderTable::DEFINE_CLASS);
duke@435 1490 SystemDictionary_lock->notify_all();
duke@435 1491 }
duke@435 1492 }
duke@435 1493
duke@435 1494 // Can't throw exception while holding lock due to rank ordering
duke@435 1495 if (linkage_exception() != NULL) {
duke@435 1496 THROW_OOP_(linkage_exception(), nh); // throws exception and returns
duke@435 1497 }
duke@435 1498
duke@435 1499 return k;
duke@435 1500 }
duke@435 1501
duke@435 1502 Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
duke@435 1503 // If class_loader is NULL we synchronize on _system_loader_lock_obj
duke@435 1504 if (class_loader.is_null()) {
duke@435 1505 return Handle(THREAD, _system_loader_lock_obj);
duke@435 1506 } else {
duke@435 1507 return class_loader;
duke@435 1508 }
duke@435 1509 }
duke@435 1510
duke@435 1511 // This method is added to check how often we have to wait to grab loader
duke@435 1512 // lock. The results are being recorded in the performance counters defined in
duke@435 1513 // ClassLoader::_sync_systemLoaderLockContentionRate and
duke@435 1514 // ClassLoader::_sync_nonSystemLoaderLockConteionRate.
duke@435 1515 void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
duke@435 1516 if (!UsePerfData) {
duke@435 1517 return;
duke@435 1518 }
duke@435 1519
duke@435 1520 assert(!loader_lock.is_null(), "NULL lock object");
duke@435 1521
duke@435 1522 if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
duke@435 1523 == ObjectSynchronizer::owner_other) {
duke@435 1524 // contention will likely happen, so increment the corresponding
duke@435 1525 // contention counter.
duke@435 1526 if (loader_lock() == _system_loader_lock_obj) {
duke@435 1527 ClassLoader::sync_systemLoaderLockContentionRate()->inc();
duke@435 1528 } else {
duke@435 1529 ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
duke@435 1530 }
duke@435 1531 }
duke@435 1532 }
duke@435 1533
duke@435 1534 // ----------------------------------------------------------------------------
duke@435 1535 // Lookup
duke@435 1536
duke@435 1537 klassOop SystemDictionary::find_class(int index, unsigned int hash,
duke@435 1538 symbolHandle class_name,
duke@435 1539 Handle class_loader) {
duke@435 1540 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 1541 assert (index == dictionary()->index_for(class_name, class_loader),
duke@435 1542 "incorrect index?");
duke@435 1543
duke@435 1544 klassOop k = dictionary()->find_class(index, hash, class_name, class_loader);
duke@435 1545 return k;
duke@435 1546 }
duke@435 1547
duke@435 1548
duke@435 1549 // Basic find on classes in the midst of being loaded
duke@435 1550 symbolOop SystemDictionary::find_placeholder(int index, unsigned int hash,
duke@435 1551 symbolHandle class_name,
duke@435 1552 Handle class_loader) {
duke@435 1553 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 1554
duke@435 1555 return placeholders()->find_entry(index, hash, class_name, class_loader);
duke@435 1556 }
duke@435 1557
duke@435 1558
duke@435 1559 // Used for assertions and verification only
duke@435 1560 oop SystemDictionary::find_class_or_placeholder(symbolHandle class_name,
duke@435 1561 Handle class_loader) {
duke@435 1562 #ifndef ASSERT
duke@435 1563 guarantee(VerifyBeforeGC ||
duke@435 1564 VerifyDuringGC ||
duke@435 1565 VerifyBeforeExit ||
duke@435 1566 VerifyAfterGC, "too expensive");
duke@435 1567 #endif
duke@435 1568 assert_locked_or_safepoint(SystemDictionary_lock);
duke@435 1569 symbolOop class_name_ = class_name();
duke@435 1570 oop class_loader_ = class_loader();
duke@435 1571
duke@435 1572 // First look in the loaded class array
duke@435 1573 unsigned int d_hash = dictionary()->compute_hash(class_name, class_loader);
duke@435 1574 int d_index = dictionary()->hash_to_index(d_hash);
duke@435 1575 oop lookup = find_class(d_index, d_hash, class_name, class_loader);
duke@435 1576
duke@435 1577 if (lookup == NULL) {
duke@435 1578 // Next try the placeholders
duke@435 1579 unsigned int p_hash = placeholders()->compute_hash(class_name,class_loader);
duke@435 1580 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 1581 lookup = find_placeholder(p_index, p_hash, class_name, class_loader);
duke@435 1582 }
duke@435 1583
duke@435 1584 return lookup;
duke@435 1585 }
duke@435 1586
duke@435 1587
duke@435 1588 // Get the next class in the diictionary.
duke@435 1589 klassOop SystemDictionary::try_get_next_class() {
duke@435 1590 return dictionary()->try_get_next_class();
duke@435 1591 }
duke@435 1592
duke@435 1593
duke@435 1594 // ----------------------------------------------------------------------------
duke@435 1595 // Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
duke@435 1596 // is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
duke@435 1597 // before a new class is used.
duke@435 1598
duke@435 1599 void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
duke@435 1600 assert(k.not_null(), "just checking");
duke@435 1601 // Link into hierachy. Make sure the vtables are initialized before linking into
duke@435 1602 k->append_to_sibling_list(); // add to superklass/sibling list
duke@435 1603 k->process_interfaces(THREAD); // handle all "implements" declarations
duke@435 1604 k->set_init_state(instanceKlass::loaded);
duke@435 1605 // Now flush all code that depended on old class hierarchy.
duke@435 1606 // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
duke@435 1607 // Also, first reinitialize vtable because it may have gotten out of synch
duke@435 1608 // while the new class wasn't connected to the class hierarchy.
duke@435 1609 Universe::flush_dependents_on(k);
duke@435 1610 }
duke@435 1611
duke@435 1612
duke@435 1613 // ----------------------------------------------------------------------------
duke@435 1614 // GC support
duke@435 1615
duke@435 1616 // Following roots during mark-sweep is separated in two phases.
duke@435 1617 //
duke@435 1618 // The first phase follows preloaded classes and all other system
duke@435 1619 // classes, since these will never get unloaded anyway.
duke@435 1620 //
duke@435 1621 // The second phase removes (unloads) unreachable classes from the
duke@435 1622 // system dictionary and follows the remaining classes' contents.
duke@435 1623
duke@435 1624 void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
duke@435 1625 // Follow preloaded classes/mirrors and system loader object
duke@435 1626 blk->do_oop(&_java_system_loader);
duke@435 1627 preloaded_oops_do(blk);
duke@435 1628 always_strong_classes_do(blk);
duke@435 1629 }
duke@435 1630
duke@435 1631
duke@435 1632 void SystemDictionary::always_strong_classes_do(OopClosure* blk) {
duke@435 1633 // Follow all system classes and temporary placeholders in dictionary
duke@435 1634 dictionary()->always_strong_classes_do(blk);
duke@435 1635
duke@435 1636 // Placeholders. These are *always* strong roots, as they
duke@435 1637 // represent classes we're actively loading.
duke@435 1638 placeholders_do(blk);
duke@435 1639
duke@435 1640 // Loader constraints. We must keep the symbolOop used in the name alive.
duke@435 1641 constraints()->always_strong_classes_do(blk);
duke@435 1642
duke@435 1643 // Resolution errors keep the symbolOop for the error alive
duke@435 1644 resolution_errors()->always_strong_classes_do(blk);
duke@435 1645 }
duke@435 1646
duke@435 1647
duke@435 1648 void SystemDictionary::placeholders_do(OopClosure* blk) {
duke@435 1649 placeholders()->oops_do(blk);
duke@435 1650 }
duke@435 1651
duke@435 1652
duke@435 1653 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
duke@435 1654 bool result = dictionary()->do_unloading(is_alive);
duke@435 1655 constraints()->purge_loader_constraints(is_alive);
duke@435 1656 resolution_errors()->purge_resolution_errors(is_alive);
duke@435 1657 return result;
duke@435 1658 }
duke@435 1659
duke@435 1660
duke@435 1661 // The mirrors are scanned by shared_oops_do() which is
duke@435 1662 // not called by oops_do(). In order to process oops in
duke@435 1663 // a necessary order, shared_oops_do() is call by
duke@435 1664 // Universe::oops_do().
duke@435 1665 void SystemDictionary::oops_do(OopClosure* f) {
duke@435 1666 // Adjust preloaded classes and system loader object
duke@435 1667 f->do_oop(&_java_system_loader);
duke@435 1668 preloaded_oops_do(f);
duke@435 1669
duke@435 1670 lazily_loaded_oops_do(f);
duke@435 1671
duke@435 1672 // Adjust dictionary
duke@435 1673 dictionary()->oops_do(f);
duke@435 1674
duke@435 1675 // Partially loaded classes
duke@435 1676 placeholders()->oops_do(f);
duke@435 1677
duke@435 1678 // Adjust constraint table
duke@435 1679 constraints()->oops_do(f);
duke@435 1680
duke@435 1681 // Adjust resolution error table
duke@435 1682 resolution_errors()->oops_do(f);
duke@435 1683 }
duke@435 1684
duke@435 1685
duke@435 1686 void SystemDictionary::preloaded_oops_do(OopClosure* f) {
duke@435 1687 f->do_oop((oop*) &_string_klass);
duke@435 1688 f->do_oop((oop*) &_object_klass);
duke@435 1689 f->do_oop((oop*) &_class_klass);
duke@435 1690 f->do_oop((oop*) &_cloneable_klass);
duke@435 1691 f->do_oop((oop*) &_classloader_klass);
duke@435 1692 f->do_oop((oop*) &_serializable_klass);
duke@435 1693 f->do_oop((oop*) &_system_klass);
duke@435 1694
duke@435 1695 f->do_oop((oop*) &_throwable_klass);
duke@435 1696 f->do_oop((oop*) &_error_klass);
duke@435 1697 f->do_oop((oop*) &_threaddeath_klass);
duke@435 1698 f->do_oop((oop*) &_exception_klass);
duke@435 1699 f->do_oop((oop*) &_runtime_exception_klass);
duke@435 1700 f->do_oop((oop*) &_classNotFoundException_klass);
duke@435 1701 f->do_oop((oop*) &_noClassDefFoundError_klass);
duke@435 1702 f->do_oop((oop*) &_linkageError_klass);
duke@435 1703 f->do_oop((oop*) &_classCastException_klass);
duke@435 1704 f->do_oop((oop*) &_arrayStoreException_klass);
duke@435 1705 f->do_oop((oop*) &_virtualMachineError_klass);
duke@435 1706 f->do_oop((oop*) &_outOfMemoryError_klass);
duke@435 1707 f->do_oop((oop*) &_StackOverflowError_klass);
duke@435 1708 f->do_oop((oop*) &_illegalMonitorStateException_klass);
duke@435 1709 f->do_oop((oop*) &_protectionDomain_klass);
duke@435 1710 f->do_oop((oop*) &_AccessControlContext_klass);
duke@435 1711
duke@435 1712 f->do_oop((oop*) &_reference_klass);
duke@435 1713 f->do_oop((oop*) &_soft_reference_klass);
duke@435 1714 f->do_oop((oop*) &_weak_reference_klass);
duke@435 1715 f->do_oop((oop*) &_final_reference_klass);
duke@435 1716 f->do_oop((oop*) &_phantom_reference_klass);
duke@435 1717 f->do_oop((oop*) &_finalizer_klass);
duke@435 1718
duke@435 1719 f->do_oop((oop*) &_thread_klass);
duke@435 1720 f->do_oop((oop*) &_threadGroup_klass);
duke@435 1721 f->do_oop((oop*) &_properties_klass);
duke@435 1722 f->do_oop((oop*) &_reflect_accessible_object_klass);
duke@435 1723 f->do_oop((oop*) &_reflect_field_klass);
duke@435 1724 f->do_oop((oop*) &_reflect_method_klass);
duke@435 1725 f->do_oop((oop*) &_reflect_constructor_klass);
duke@435 1726 f->do_oop((oop*) &_reflect_magic_klass);
duke@435 1727 f->do_oop((oop*) &_reflect_method_accessor_klass);
duke@435 1728 f->do_oop((oop*) &_reflect_constructor_accessor_klass);
duke@435 1729 f->do_oop((oop*) &_reflect_delegating_classloader_klass);
duke@435 1730 f->do_oop((oop*) &_reflect_constant_pool_klass);
duke@435 1731 f->do_oop((oop*) &_reflect_unsafe_static_field_accessor_impl_klass);
duke@435 1732
duke@435 1733 f->do_oop((oop*) &_stringBuffer_klass);
duke@435 1734 f->do_oop((oop*) &_vector_klass);
duke@435 1735 f->do_oop((oop*) &_hashtable_klass);
duke@435 1736
duke@435 1737 f->do_oop((oop*) &_stackTraceElement_klass);
duke@435 1738
duke@435 1739 f->do_oop((oop*) &_java_nio_Buffer_klass);
duke@435 1740
duke@435 1741 f->do_oop((oop*) &_sun_misc_AtomicLongCSImpl_klass);
duke@435 1742 f->do_oop((oop*) &_sun_jkernel_DownloadManager_klass);
duke@435 1743
duke@435 1744 f->do_oop((oop*) &_boolean_klass);
duke@435 1745 f->do_oop((oop*) &_char_klass);
duke@435 1746 f->do_oop((oop*) &_float_klass);
duke@435 1747 f->do_oop((oop*) &_double_klass);
duke@435 1748 f->do_oop((oop*) &_byte_klass);
duke@435 1749 f->do_oop((oop*) &_short_klass);
duke@435 1750 f->do_oop((oop*) &_int_klass);
duke@435 1751 f->do_oop((oop*) &_long_klass);
duke@435 1752 {
duke@435 1753 for (int i = 0; i < T_VOID+1; i++) {
duke@435 1754 if (_box_klasses[i] != NULL) {
duke@435 1755 assert(i >= T_BOOLEAN, "checking");
duke@435 1756 f->do_oop((oop*) &_box_klasses[i]);
duke@435 1757 }
duke@435 1758 }
duke@435 1759 }
duke@435 1760
duke@435 1761 // The basic type mirrors would have already been processed in
duke@435 1762 // Universe::oops_do(), via a call to shared_oops_do(), so should
duke@435 1763 // not be processed again.
duke@435 1764
duke@435 1765 f->do_oop((oop*) &_system_loader_lock_obj);
duke@435 1766 FilteredFieldsMap::klasses_oops_do(f);
duke@435 1767 }
duke@435 1768
duke@435 1769 void SystemDictionary::lazily_loaded_oops_do(OopClosure* f) {
duke@435 1770 f->do_oop((oop*) &_abstract_ownable_synchronizer_klass);
duke@435 1771 }
duke@435 1772
duke@435 1773 // Just the classes from defining class loaders
duke@435 1774 // Don't iterate over placeholders
duke@435 1775 void SystemDictionary::classes_do(void f(klassOop)) {
duke@435 1776 dictionary()->classes_do(f);
duke@435 1777 }
duke@435 1778
duke@435 1779 // Added for initialize_itable_for_klass
duke@435 1780 // Just the classes from defining class loaders
duke@435 1781 // Don't iterate over placeholders
duke@435 1782 void SystemDictionary::classes_do(void f(klassOop, TRAPS), TRAPS) {
duke@435 1783 dictionary()->classes_do(f, CHECK);
duke@435 1784 }
duke@435 1785
duke@435 1786 // All classes, and their class loaders
duke@435 1787 // Don't iterate over placeholders
duke@435 1788 void SystemDictionary::classes_do(void f(klassOop, oop)) {
duke@435 1789 dictionary()->classes_do(f);
duke@435 1790 }
duke@435 1791
duke@435 1792 // All classes, and their class loaders
duke@435 1793 // (added for helpers that use HandleMarks and ResourceMarks)
duke@435 1794 // Don't iterate over placeholders
duke@435 1795 void SystemDictionary::classes_do(void f(klassOop, oop, TRAPS), TRAPS) {
duke@435 1796 dictionary()->classes_do(f, CHECK);
duke@435 1797 }
duke@435 1798
duke@435 1799 void SystemDictionary::placeholders_do(void f(symbolOop, oop)) {
duke@435 1800 placeholders()->entries_do(f);
duke@435 1801 }
duke@435 1802
duke@435 1803 void SystemDictionary::methods_do(void f(methodOop)) {
duke@435 1804 dictionary()->methods_do(f);
duke@435 1805 }
duke@435 1806
duke@435 1807 // ----------------------------------------------------------------------------
duke@435 1808 // Lazily load klasses
duke@435 1809
duke@435 1810 void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
duke@435 1811 assert(JDK_Version::is_gte_jdk16x_version(), "Must be JDK 1.6 or later");
duke@435 1812
duke@435 1813 // if multiple threads calling this function, only one thread will load
duke@435 1814 // the class. The other threads will find the loaded version once the
duke@435 1815 // class is loaded.
duke@435 1816 klassOop aos = _abstract_ownable_synchronizer_klass;
duke@435 1817 if (aos == NULL) {
duke@435 1818 klassOop k = resolve_or_fail(vmSymbolHandles::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
duke@435 1819 // Force a fence to prevent any read before the write completes
duke@435 1820 OrderAccess::fence();
duke@435 1821 _abstract_ownable_synchronizer_klass = k;
duke@435 1822 }
duke@435 1823 }
duke@435 1824
duke@435 1825 // ----------------------------------------------------------------------------
duke@435 1826 // Initialization
duke@435 1827
duke@435 1828 void SystemDictionary::initialize(TRAPS) {
duke@435 1829 // Allocate arrays
duke@435 1830 assert(dictionary() == NULL,
duke@435 1831 "SystemDictionary should only be initialized once");
duke@435 1832 _dictionary = new Dictionary(_nof_buckets);
duke@435 1833 _placeholders = new PlaceholderTable(_nof_buckets);
duke@435 1834 _number_of_modifications = 0;
duke@435 1835 _loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
duke@435 1836 _resolution_errors = new ResolutionErrorTable(_resolution_error_size);
duke@435 1837
duke@435 1838 // Allocate private object used as system class loader lock
duke@435 1839 _system_loader_lock_obj = oopFactory::new_system_objArray(0, CHECK);
duke@435 1840 // Initialize basic classes
duke@435 1841 initialize_preloaded_classes(CHECK);
duke@435 1842 }
duke@435 1843
duke@435 1844
duke@435 1845 void SystemDictionary::initialize_preloaded_classes(TRAPS) {
duke@435 1846 assert(_object_klass == NULL, "preloaded classes should only be initialized once");
duke@435 1847 // Preload commonly used klasses
duke@435 1848 _object_klass = resolve_or_fail(vmSymbolHandles::java_lang_Object(), true, CHECK);
duke@435 1849 _string_klass = resolve_or_fail(vmSymbolHandles::java_lang_String(), true, CHECK);
duke@435 1850 _class_klass = resolve_or_fail(vmSymbolHandles::java_lang_Class(), true, CHECK);
duke@435 1851 debug_only(instanceKlass::verify_class_klass_nonstatic_oop_maps(_class_klass));
duke@435 1852 // Fixup mirrors for classes loaded before java.lang.Class.
duke@435 1853 // These calls iterate over the objects currently in the perm gen
duke@435 1854 // so calling them at this point is matters (not before when there
duke@435 1855 // are fewer objects and not later after there are more objects
duke@435 1856 // in the perm gen.
duke@435 1857 Universe::initialize_basic_type_mirrors(CHECK);
duke@435 1858 Universe::fixup_mirrors(CHECK);
duke@435 1859
duke@435 1860 _cloneable_klass = resolve_or_fail(vmSymbolHandles::java_lang_Cloneable(), true, CHECK);
duke@435 1861 _classloader_klass = resolve_or_fail(vmSymbolHandles::java_lang_ClassLoader(), true, CHECK);
duke@435 1862 _serializable_klass = resolve_or_fail(vmSymbolHandles::java_io_Serializable(), true, CHECK);
duke@435 1863 _system_klass = resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
duke@435 1864
duke@435 1865 _throwable_klass = resolve_or_fail(vmSymbolHandles::java_lang_Throwable(), true, CHECK);
duke@435 1866 _error_klass = resolve_or_fail(vmSymbolHandles::java_lang_Error(), true, CHECK);
duke@435 1867 _threaddeath_klass = resolve_or_fail(vmSymbolHandles::java_lang_ThreadDeath(), true, CHECK);
duke@435 1868 _exception_klass = resolve_or_fail(vmSymbolHandles::java_lang_Exception(), true, CHECK);
duke@435 1869 _runtime_exception_klass = resolve_or_fail(vmSymbolHandles::java_lang_RuntimeException(), true, CHECK);
duke@435 1870 _protectionDomain_klass = resolve_or_fail(vmSymbolHandles::java_security_ProtectionDomain(), true, CHECK);
duke@435 1871 _AccessControlContext_klass = resolve_or_fail(vmSymbolHandles::java_security_AccessControlContext(), true, CHECK);
duke@435 1872 _classNotFoundException_klass = resolve_or_fail(vmSymbolHandles::java_lang_ClassNotFoundException(), true, CHECK);
duke@435 1873 _noClassDefFoundError_klass = resolve_or_fail(vmSymbolHandles::java_lang_NoClassDefFoundError(), true, CHECK);
duke@435 1874 _linkageError_klass = resolve_or_fail(vmSymbolHandles::java_lang_LinkageError(), true, CHECK);
duke@435 1875 _classCastException_klass = resolve_or_fail(vmSymbolHandles::java_lang_ClassCastException(), true, CHECK);
duke@435 1876 _arrayStoreException_klass = resolve_or_fail(vmSymbolHandles::java_lang_ArrayStoreException(), true, CHECK);
duke@435 1877 _virtualMachineError_klass = resolve_or_fail(vmSymbolHandles::java_lang_VirtualMachineError(), true, CHECK);
duke@435 1878 _outOfMemoryError_klass = resolve_or_fail(vmSymbolHandles::java_lang_OutOfMemoryError(), true, CHECK);
duke@435 1879 _StackOverflowError_klass = resolve_or_fail(vmSymbolHandles::java_lang_StackOverflowError(), true, CHECK);
duke@435 1880 _illegalMonitorStateException_klass = resolve_or_fail(vmSymbolHandles::java_lang_IllegalMonitorStateException(), true, CHECK);
duke@435 1881
duke@435 1882 // Preload ref klasses and set reference types
duke@435 1883 _reference_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_Reference(), true, CHECK);
duke@435 1884 instanceKlass::cast(_reference_klass)->set_reference_type(REF_OTHER);
duke@435 1885 instanceRefKlass::update_nonstatic_oop_maps(_reference_klass);
duke@435 1886
duke@435 1887 _soft_reference_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_SoftReference(), true, CHECK);
duke@435 1888 instanceKlass::cast(_soft_reference_klass)->set_reference_type(REF_SOFT);
duke@435 1889 _weak_reference_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_WeakReference(), true, CHECK);
duke@435 1890 instanceKlass::cast(_weak_reference_klass)->set_reference_type(REF_WEAK);
duke@435 1891 _final_reference_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_FinalReference(), true, CHECK);
duke@435 1892 instanceKlass::cast(_final_reference_klass)->set_reference_type(REF_FINAL);
duke@435 1893 _phantom_reference_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_PhantomReference(), true, CHECK);
duke@435 1894 instanceKlass::cast(_phantom_reference_klass)->set_reference_type(REF_PHANTOM);
duke@435 1895 _finalizer_klass = resolve_or_fail(vmSymbolHandles::java_lang_ref_Finalizer(), true, CHECK);
duke@435 1896
duke@435 1897 _thread_klass = resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
duke@435 1898 _threadGroup_klass = resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK);
duke@435 1899 _properties_klass = resolve_or_fail(vmSymbolHandles::java_util_Properties(), true, CHECK);
duke@435 1900 _reflect_accessible_object_klass = resolve_or_fail(vmSymbolHandles::java_lang_reflect_AccessibleObject(), true, CHECK);
duke@435 1901 _reflect_field_klass = resolve_or_fail(vmSymbolHandles::java_lang_reflect_Field(), true, CHECK);
duke@435 1902 _reflect_method_klass = resolve_or_fail(vmSymbolHandles::java_lang_reflect_Method(), true, CHECK);
duke@435 1903 _reflect_constructor_klass = resolve_or_fail(vmSymbolHandles::java_lang_reflect_Constructor(), true, CHECK);
duke@435 1904 // Universe::is_gte_jdk14x_version() is not set up by this point.
duke@435 1905 // It's okay if these turn out to be NULL in non-1.4 JDKs.
duke@435 1906 _reflect_magic_klass = resolve_or_null(vmSymbolHandles::sun_reflect_MagicAccessorImpl(), CHECK);
duke@435 1907 _reflect_method_accessor_klass = resolve_or_null(vmSymbolHandles::sun_reflect_MethodAccessorImpl(), CHECK);
duke@435 1908 _reflect_constructor_accessor_klass = resolve_or_null(vmSymbolHandles::sun_reflect_ConstructorAccessorImpl(), CHECK);
duke@435 1909 _reflect_delegating_classloader_klass = resolve_or_null(vmSymbolHandles::sun_reflect_DelegatingClassLoader(), CHECK);
duke@435 1910 _reflect_constant_pool_klass = resolve_or_null(vmSymbolHandles::sun_reflect_ConstantPool(), CHECK);
duke@435 1911 _reflect_unsafe_static_field_accessor_impl_klass = resolve_or_null(vmSymbolHandles::sun_reflect_UnsafeStaticFieldAccessorImpl(), CHECK);
duke@435 1912
duke@435 1913 _vector_klass = resolve_or_fail(vmSymbolHandles::java_util_Vector(), true, CHECK);
duke@435 1914 _hashtable_klass = resolve_or_fail(vmSymbolHandles::java_util_Hashtable(), true, CHECK);
duke@435 1915 _stringBuffer_klass = resolve_or_fail(vmSymbolHandles::java_lang_StringBuffer(), true, CHECK);
duke@435 1916
duke@435 1917 // It's NULL in non-1.4 JDKs.
duke@435 1918 _stackTraceElement_klass = resolve_or_null(vmSymbolHandles::java_lang_StackTraceElement(), CHECK);
duke@435 1919
duke@435 1920 // Universe::is_gte_jdk14x_version() is not set up by this point.
duke@435 1921 // It's okay if this turns out to be NULL in non-1.4 JDKs.
duke@435 1922 _java_nio_Buffer_klass = resolve_or_null(vmSymbolHandles::java_nio_Buffer(), CHECK);
duke@435 1923
duke@435 1924 // If this class isn't present, it won't be referenced.
duke@435 1925 _sun_misc_AtomicLongCSImpl_klass = resolve_or_null(vmSymbolHandles::sun_misc_AtomicLongCSImpl(), CHECK);
duke@435 1926 #ifdef KERNEL
duke@435 1927 _sun_jkernel_DownloadManager_klass = resolve_or_null(vmSymbolHandles::sun_jkernel_DownloadManager(), CHECK);
duke@435 1928 if (_sun_jkernel_DownloadManager_klass == NULL) {
duke@435 1929 warning("Cannot find sun/jkernel/DownloadManager");
duke@435 1930 }
duke@435 1931 #endif // KERNEL
duke@435 1932
duke@435 1933 // Preload boxing klasses
duke@435 1934 _boolean_klass = resolve_or_fail(vmSymbolHandles::java_lang_Boolean(), true, CHECK);
duke@435 1935 _char_klass = resolve_or_fail(vmSymbolHandles::java_lang_Character(), true, CHECK);
duke@435 1936 _float_klass = resolve_or_fail(vmSymbolHandles::java_lang_Float(), true, CHECK);
duke@435 1937 _double_klass = resolve_or_fail(vmSymbolHandles::java_lang_Double(), true, CHECK);
duke@435 1938 _byte_klass = resolve_or_fail(vmSymbolHandles::java_lang_Byte(), true, CHECK);
duke@435 1939 _short_klass = resolve_or_fail(vmSymbolHandles::java_lang_Short(), true, CHECK);
duke@435 1940 _int_klass = resolve_or_fail(vmSymbolHandles::java_lang_Integer(), true, CHECK);
duke@435 1941 _long_klass = resolve_or_fail(vmSymbolHandles::java_lang_Long(), true, CHECK);
duke@435 1942
duke@435 1943 _box_klasses[T_BOOLEAN] = _boolean_klass;
duke@435 1944 _box_klasses[T_CHAR] = _char_klass;
duke@435 1945 _box_klasses[T_FLOAT] = _float_klass;
duke@435 1946 _box_klasses[T_DOUBLE] = _double_klass;
duke@435 1947 _box_klasses[T_BYTE] = _byte_klass;
duke@435 1948 _box_klasses[T_SHORT] = _short_klass;
duke@435 1949 _box_klasses[T_INT] = _int_klass;
duke@435 1950 _box_klasses[T_LONG] = _long_klass;
duke@435 1951 //_box_klasses[T_OBJECT] = _object_klass;
duke@435 1952 //_box_klasses[T_ARRAY] = _object_klass;
duke@435 1953
duke@435 1954 { // Compute whether we should use loadClass or loadClassInternal when loading classes.
duke@435 1955 methodOop method = instanceKlass::cast(classloader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
duke@435 1956 _has_loadClassInternal = (method != NULL);
duke@435 1957 }
duke@435 1958
duke@435 1959 { // Compute whether we should use checkPackageAccess or NOT
duke@435 1960 methodOop method = instanceKlass::cast(classloader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
duke@435 1961 _has_checkPackageAccess = (method != NULL);
duke@435 1962 }
duke@435 1963 }
duke@435 1964
duke@435 1965 // Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
duke@435 1966 // If so, returns the basic type it holds. If not, returns T_OBJECT.
duke@435 1967 BasicType SystemDictionary::box_klass_type(klassOop k) {
duke@435 1968 assert(k != NULL, "");
duke@435 1969 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
duke@435 1970 if (_box_klasses[i] == k)
duke@435 1971 return (BasicType)i;
duke@435 1972 }
duke@435 1973 return T_OBJECT;
duke@435 1974 }
duke@435 1975
duke@435 1976 // Constraints on class loaders. The details of the algorithm can be
duke@435 1977 // found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
duke@435 1978 // Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
duke@435 1979 // that the system dictionary needs to maintain a set of contraints that
duke@435 1980 // must be satisfied by all classes in the dictionary.
duke@435 1981 // if defining is true, then LinkageError if already in systemDictionary
duke@435 1982 // if initiating loader, then ok if instanceKlass matches existing entry
duke@435 1983
duke@435 1984 void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
duke@435 1985 instanceKlassHandle k,
duke@435 1986 Handle class_loader, bool defining,
duke@435 1987 TRAPS) {
duke@435 1988 const char *linkage_error = NULL;
duke@435 1989 {
duke@435 1990 symbolHandle name (THREAD, k->name());
duke@435 1991 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 1992
duke@435 1993 klassOop check = find_class(d_index, d_hash, name, class_loader);
duke@435 1994 if (check != (klassOop)NULL) {
duke@435 1995 // if different instanceKlass - duplicate class definition,
duke@435 1996 // else - ok, class loaded by a different thread in parallel,
duke@435 1997 // we should only have found it if it was done loading and ok to use
duke@435 1998 // system dictionary only holds instance classes, placeholders
duke@435 1999 // also holds array classes
duke@435 2000
duke@435 2001 assert(check->klass_part()->oop_is_instance(), "noninstance in systemdictionary");
duke@435 2002 if ((defining == true) || (k() != check)) {
duke@435 2003 linkage_error = "loader (instance of %s): attempted duplicate class "
duke@435 2004 "definition for name: \"%s\"";
duke@435 2005 } else {
duke@435 2006 return;
duke@435 2007 }
duke@435 2008 }
duke@435 2009
duke@435 2010 #ifdef ASSERT
duke@435 2011 unsigned int p_hash = placeholders()->compute_hash(name, class_loader);
duke@435 2012 int p_index = placeholders()->hash_to_index(p_hash);
duke@435 2013 symbolOop ph_check = find_placeholder(p_index, p_hash, name, class_loader);
duke@435 2014 assert(ph_check == NULL || ph_check == name(), "invalid symbol");
duke@435 2015 #endif
duke@435 2016
duke@435 2017 if (linkage_error == NULL) {
duke@435 2018 if (constraints()->check_or_update(k, class_loader, name) == false) {
duke@435 2019 linkage_error = "loader constraint violation: loader (instance of %s)"
duke@435 2020 " previously initiated loading for a different type with name \"%s\"";
duke@435 2021 }
duke@435 2022 }
duke@435 2023 }
duke@435 2024
duke@435 2025 // Throw error now if needed (cannot throw while holding
duke@435 2026 // SystemDictionary_lock because of rank ordering)
duke@435 2027
duke@435 2028 if (linkage_error) {
duke@435 2029 ResourceMark rm(THREAD);
duke@435 2030 const char* class_loader_name = loader_name(class_loader());
duke@435 2031 char* type_name = k->name()->as_C_string();
duke@435 2032 size_t buflen = strlen(linkage_error) + strlen(class_loader_name) +
duke@435 2033 strlen(type_name);
duke@435 2034 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
duke@435 2035 jio_snprintf(buf, buflen, linkage_error, class_loader_name, type_name);
duke@435 2036 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
duke@435 2037 }
duke@435 2038 }
duke@435 2039
duke@435 2040
duke@435 2041 // Update system dictionary - done after check_constraint and add_to_hierachy
duke@435 2042 // have been called.
duke@435 2043 void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
duke@435 2044 int p_index, unsigned int p_hash,
duke@435 2045 instanceKlassHandle k,
duke@435 2046 Handle class_loader,
duke@435 2047 TRAPS) {
duke@435 2048 // Compile_lock prevents systemDictionary updates during compilations
duke@435 2049 assert_locked_or_safepoint(Compile_lock);
duke@435 2050 symbolHandle name (THREAD, k->name());
duke@435 2051
duke@435 2052 {
duke@435 2053 MutexLocker mu1(SystemDictionary_lock, THREAD);
duke@435 2054
duke@435 2055 // See whether biased locking is enabled and if so set it for this
duke@435 2056 // klass.
duke@435 2057 // Note that this must be done past the last potential blocking
duke@435 2058 // point / safepoint. We enable biased locking lazily using a
duke@435 2059 // VM_Operation to iterate the SystemDictionary and installing the
duke@435 2060 // biasable mark word into each instanceKlass's prototype header.
duke@435 2061 // To avoid race conditions where we accidentally miss enabling the
duke@435 2062 // optimization for one class in the process of being added to the
duke@435 2063 // dictionary, we must not safepoint after the test of
duke@435 2064 // BiasedLocking::enabled().
duke@435 2065 if (UseBiasedLocking && BiasedLocking::enabled()) {
duke@435 2066 // Set biased locking bit for all loaded classes; it will be
duke@435 2067 // cleared if revocation occurs too often for this type
duke@435 2068 // NOTE that we must only do this when the class is initally
duke@435 2069 // defined, not each time it is referenced from a new class loader
duke@435 2070 if (k->class_loader() == class_loader()) {
duke@435 2071 k->set_prototype_header(markOopDesc::biased_locking_prototype());
duke@435 2072 }
duke@435 2073 }
duke@435 2074
duke@435 2075 // Check for a placeholder. If there, remove it and make a
duke@435 2076 // new system dictionary entry.
duke@435 2077 placeholders()->find_and_remove(p_index, p_hash, name, class_loader, THREAD);
duke@435 2078 klassOop sd_check = find_class(d_index, d_hash, name, class_loader);
duke@435 2079 if (sd_check == NULL) {
duke@435 2080 dictionary()->add_klass(name, class_loader, k);
duke@435 2081 notice_modification();
duke@435 2082 }
duke@435 2083 #ifdef ASSERT
duke@435 2084 sd_check = find_class(d_index, d_hash, name, class_loader);
duke@435 2085 assert (sd_check != NULL, "should have entry in system dictionary");
duke@435 2086 // Changed to allow PH to remain to complete class circularity checking
duke@435 2087 // while only one thread can define a class at one time, multiple
duke@435 2088 // classes can resolve the superclass for a class at one time,
duke@435 2089 // and the placeholder is used to track that
duke@435 2090 // symbolOop ph_check = find_placeholder(p_index, p_hash, name, class_loader);
duke@435 2091 // assert (ph_check == NULL, "should not have a placeholder entry");
duke@435 2092 #endif
duke@435 2093 SystemDictionary_lock->notify_all();
duke@435 2094 }
duke@435 2095 }
duke@435 2096
duke@435 2097
duke@435 2098 klassOop SystemDictionary::find_constrained_instance_or_array_klass(
duke@435 2099 symbolHandle class_name, Handle class_loader, TRAPS) {
duke@435 2100
duke@435 2101 // First see if it has been loaded directly.
duke@435 2102 // Force the protection domain to be null. (This removes protection checks.)
duke@435 2103 Handle no_protection_domain;
duke@435 2104 klassOop klass = find_instance_or_array_klass(class_name, class_loader,
duke@435 2105 no_protection_domain, CHECK_NULL);
duke@435 2106 if (klass != NULL)
duke@435 2107 return klass;
duke@435 2108
duke@435 2109 // Now look to see if it has been loaded elsewhere, and is subject to
duke@435 2110 // a loader constraint that would require this loader to return the
duke@435 2111 // klass that is already loaded.
duke@435 2112 if (FieldType::is_array(class_name())) {
duke@435 2113 // Array classes are hard because their klassOops are not kept in the
duke@435 2114 // constraint table. The array klass may be constrained, but the elem class
duke@435 2115 // may not be.
duke@435 2116 jint dimension;
duke@435 2117 symbolOop object_key;
duke@435 2118 BasicType t = FieldType::get_array_info(class_name(), &dimension,
duke@435 2119 &object_key, CHECK_(NULL));
duke@435 2120 if (t != T_OBJECT) {
duke@435 2121 klass = Universe::typeArrayKlassObj(t);
duke@435 2122 } else {
duke@435 2123 symbolHandle elem_name(THREAD, object_key);
duke@435 2124 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 2125 klass = constraints()->find_constrained_elem_klass(class_name, elem_name, class_loader, THREAD);
duke@435 2126 }
duke@435 2127 if (klass != NULL) {
duke@435 2128 klass = Klass::cast(klass)->array_klass_or_null(dimension);
duke@435 2129 }
duke@435 2130 } else {
duke@435 2131 MutexLocker mu(SystemDictionary_lock, THREAD);
duke@435 2132 // Non-array classes are easy: simply check the constraint table.
duke@435 2133 klass = constraints()->find_constrained_klass(class_name, class_loader);
duke@435 2134 }
duke@435 2135
duke@435 2136 return klass;
duke@435 2137 }
duke@435 2138
duke@435 2139
duke@435 2140 bool SystemDictionary::add_loader_constraint(symbolHandle class_name,
duke@435 2141 Handle class_loader1,
duke@435 2142 Handle class_loader2,
duke@435 2143 Thread* THREAD) {
duke@435 2144 unsigned int d_hash1 = dictionary()->compute_hash(class_name, class_loader1);
duke@435 2145 int d_index1 = dictionary()->hash_to_index(d_hash1);
duke@435 2146
duke@435 2147 unsigned int d_hash2 = dictionary()->compute_hash(class_name, class_loader2);
duke@435 2148 int d_index2 = dictionary()->hash_to_index(d_hash2);
duke@435 2149
duke@435 2150 {
duke@435 2151 MutexLocker mu_s(SystemDictionary_lock, THREAD);
duke@435 2152
duke@435 2153 // Better never do a GC while we're holding these oops
duke@435 2154 No_Safepoint_Verifier nosafepoint;
duke@435 2155
duke@435 2156 klassOop klass1 = find_class(d_index1, d_hash1, class_name, class_loader1);
duke@435 2157 klassOop klass2 = find_class(d_index2, d_hash2, class_name, class_loader2);
duke@435 2158 return constraints()->add_entry(class_name, klass1, class_loader1,
duke@435 2159 klass2, class_loader2);
duke@435 2160 }
duke@435 2161 }
duke@435 2162
duke@435 2163 // Add entry to resolution error table to record the error when the first
duke@435 2164 // attempt to resolve a reference to a class has failed.
duke@435 2165 void SystemDictionary::add_resolution_error(constantPoolHandle pool, int which, symbolHandle error) {
duke@435 2166 unsigned int hash = resolution_errors()->compute_hash(pool, which);
duke@435 2167 int index = resolution_errors()->hash_to_index(hash);
duke@435 2168 {
duke@435 2169 MutexLocker ml(SystemDictionary_lock, Thread::current());
duke@435 2170 resolution_errors()->add_entry(index, hash, pool, which, error);
duke@435 2171 }
duke@435 2172 }
duke@435 2173
duke@435 2174 // Lookup resolution error table. Returns error if found, otherwise NULL.
duke@435 2175 symbolOop SystemDictionary::find_resolution_error(constantPoolHandle pool, int which) {
duke@435 2176 unsigned int hash = resolution_errors()->compute_hash(pool, which);
duke@435 2177 int index = resolution_errors()->hash_to_index(hash);
duke@435 2178 {
duke@435 2179 MutexLocker ml(SystemDictionary_lock, Thread::current());
duke@435 2180 ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
duke@435 2181 return (entry != NULL) ? entry->error() : (symbolOop)NULL;
duke@435 2182 }
duke@435 2183 }
duke@435 2184
duke@435 2185
duke@435 2186 // Make sure all class components (including arrays) in the given
duke@435 2187 // signature will be resolved to the same class in both loaders.
duke@435 2188 // Returns the name of the type that failed a loader constraint check, or
duke@435 2189 // NULL if no constraint failed. The returned C string needs cleaning up
duke@435 2190 // with a ResourceMark in the caller
duke@435 2191 char* SystemDictionary::check_signature_loaders(symbolHandle signature,
duke@435 2192 Handle loader1, Handle loader2,
duke@435 2193 bool is_method, TRAPS) {
duke@435 2194 // Nothing to do if loaders are the same.
duke@435 2195 if (loader1() == loader2()) {
duke@435 2196 return NULL;
duke@435 2197 }
duke@435 2198
duke@435 2199 SignatureStream sig_strm(signature, is_method);
duke@435 2200 while (!sig_strm.is_done()) {
duke@435 2201 if (sig_strm.is_object()) {
duke@435 2202 symbolOop s = sig_strm.as_symbol(CHECK_NULL);
duke@435 2203 symbolHandle sig (THREAD, s);
duke@435 2204 if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
duke@435 2205 return sig()->as_C_string();
duke@435 2206 }
duke@435 2207 }
duke@435 2208 sig_strm.next();
duke@435 2209 }
duke@435 2210 return NULL;
duke@435 2211 }
duke@435 2212
duke@435 2213
duke@435 2214 // Since the identity hash code for symbols changes when the symbols are
duke@435 2215 // moved from the regular perm gen (hash in the mark word) to the shared
duke@435 2216 // spaces (hash is the address), the classes loaded into the dictionary
duke@435 2217 // may be in the wrong buckets.
duke@435 2218
duke@435 2219 void SystemDictionary::reorder_dictionary() {
duke@435 2220 dictionary()->reorder_dictionary();
duke@435 2221 }
duke@435 2222
duke@435 2223
duke@435 2224 void SystemDictionary::copy_buckets(char** top, char* end) {
duke@435 2225 dictionary()->copy_buckets(top, end);
duke@435 2226 }
duke@435 2227
duke@435 2228
duke@435 2229 void SystemDictionary::copy_table(char** top, char* end) {
duke@435 2230 dictionary()->copy_table(top, end);
duke@435 2231 }
duke@435 2232
duke@435 2233
duke@435 2234 void SystemDictionary::reverse() {
duke@435 2235 dictionary()->reverse();
duke@435 2236 }
duke@435 2237
duke@435 2238 int SystemDictionary::number_of_classes() {
duke@435 2239 return dictionary()->number_of_entries();
duke@435 2240 }
duke@435 2241
duke@435 2242
duke@435 2243 // ----------------------------------------------------------------------------
duke@435 2244 #ifndef PRODUCT
duke@435 2245
duke@435 2246 void SystemDictionary::print() {
duke@435 2247 dictionary()->print();
duke@435 2248
duke@435 2249 // Placeholders
duke@435 2250 GCMutexLocker mu(SystemDictionary_lock);
duke@435 2251 placeholders()->print();
duke@435 2252
duke@435 2253 // loader constraints - print under SD_lock
duke@435 2254 constraints()->print();
duke@435 2255 }
duke@435 2256
duke@435 2257 #endif
duke@435 2258
duke@435 2259 void SystemDictionary::verify() {
duke@435 2260 guarantee(dictionary() != NULL, "Verify of system dictionary failed");
duke@435 2261 guarantee(constraints() != NULL,
duke@435 2262 "Verify of loader constraints failed");
duke@435 2263 guarantee(dictionary()->number_of_entries() >= 0 &&
duke@435 2264 placeholders()->number_of_entries() >= 0,
duke@435 2265 "Verify of system dictionary failed");
duke@435 2266
duke@435 2267 // Verify dictionary
duke@435 2268 dictionary()->verify();
duke@435 2269
duke@435 2270 GCMutexLocker mu(SystemDictionary_lock);
duke@435 2271 placeholders()->verify();
duke@435 2272
duke@435 2273 // Verify constraint table
duke@435 2274 guarantee(constraints() != NULL, "Verify of loader constraints failed");
duke@435 2275 constraints()->verify(dictionary());
duke@435 2276 }
duke@435 2277
duke@435 2278
duke@435 2279 void SystemDictionary::verify_obj_klass_present(Handle obj,
duke@435 2280 symbolHandle class_name,
duke@435 2281 Handle class_loader) {
duke@435 2282 GCMutexLocker mu(SystemDictionary_lock);
duke@435 2283 oop probe = find_class_or_placeholder(class_name, class_loader);
duke@435 2284 if (probe == NULL) {
duke@435 2285 probe = SystemDictionary::find_shared_class(class_name);
duke@435 2286 }
duke@435 2287 guarantee(probe != NULL &&
duke@435 2288 (!probe->is_klass() || probe == obj()),
duke@435 2289 "Loaded klasses should be in SystemDictionary");
duke@435 2290 }
duke@435 2291
duke@435 2292 #ifndef PRODUCT
duke@435 2293
duke@435 2294 // statistics code
duke@435 2295 class ClassStatistics: AllStatic {
duke@435 2296 private:
duke@435 2297 static int nclasses; // number of classes
duke@435 2298 static int nmethods; // number of methods
duke@435 2299 static int nmethoddata; // number of methodData
duke@435 2300 static int class_size; // size of class objects in words
duke@435 2301 static int method_size; // size of method objects in words
duke@435 2302 static int debug_size; // size of debug info in methods
duke@435 2303 static int methoddata_size; // size of methodData objects in words
duke@435 2304
duke@435 2305 static void do_class(klassOop k) {
duke@435 2306 nclasses++;
duke@435 2307 class_size += k->size();
duke@435 2308 if (k->klass_part()->oop_is_instance()) {
duke@435 2309 instanceKlass* ik = (instanceKlass*)k->klass_part();
duke@435 2310 class_size += ik->methods()->size();
duke@435 2311 class_size += ik->constants()->size();
duke@435 2312 class_size += ik->local_interfaces()->size();
duke@435 2313 class_size += ik->transitive_interfaces()->size();
duke@435 2314 // We do not have to count implementors, since we only store one!
duke@435 2315 class_size += ik->fields()->size();
duke@435 2316 }
duke@435 2317 }
duke@435 2318
duke@435 2319 static void do_method(methodOop m) {
duke@435 2320 nmethods++;
duke@435 2321 method_size += m->size();
duke@435 2322 // class loader uses same objArray for empty vectors, so don't count these
duke@435 2323 if (m->exception_table()->length() != 0) method_size += m->exception_table()->size();
duke@435 2324 if (m->has_stackmap_table()) {
duke@435 2325 method_size += m->stackmap_data()->size();
duke@435 2326 }
duke@435 2327
duke@435 2328 methodDataOop mdo = m->method_data();
duke@435 2329 if (mdo != NULL) {
duke@435 2330 nmethoddata++;
duke@435 2331 methoddata_size += mdo->size();
duke@435 2332 }
duke@435 2333 }
duke@435 2334
duke@435 2335 public:
duke@435 2336 static void print() {
duke@435 2337 SystemDictionary::classes_do(do_class);
duke@435 2338 SystemDictionary::methods_do(do_method);
duke@435 2339 tty->print_cr("Class statistics:");
duke@435 2340 tty->print_cr("%d classes (%d bytes)", nclasses, class_size * oopSize);
duke@435 2341 tty->print_cr("%d methods (%d bytes = %d base + %d debug info)", nmethods,
duke@435 2342 (method_size + debug_size) * oopSize, method_size * oopSize, debug_size * oopSize);
duke@435 2343 tty->print_cr("%d methoddata (%d bytes)", nmethoddata, methoddata_size * oopSize);
duke@435 2344 }
duke@435 2345 };
duke@435 2346
duke@435 2347
duke@435 2348 int ClassStatistics::nclasses = 0;
duke@435 2349 int ClassStatistics::nmethods = 0;
duke@435 2350 int ClassStatistics::nmethoddata = 0;
duke@435 2351 int ClassStatistics::class_size = 0;
duke@435 2352 int ClassStatistics::method_size = 0;
duke@435 2353 int ClassStatistics::debug_size = 0;
duke@435 2354 int ClassStatistics::methoddata_size = 0;
duke@435 2355
duke@435 2356 void SystemDictionary::print_class_statistics() {
duke@435 2357 ResourceMark rm;
duke@435 2358 ClassStatistics::print();
duke@435 2359 }
duke@435 2360
duke@435 2361
duke@435 2362 class MethodStatistics: AllStatic {
duke@435 2363 public:
duke@435 2364 enum {
duke@435 2365 max_parameter_size = 10
duke@435 2366 };
duke@435 2367 private:
duke@435 2368
duke@435 2369 static int _number_of_methods;
duke@435 2370 static int _number_of_final_methods;
duke@435 2371 static int _number_of_static_methods;
duke@435 2372 static int _number_of_native_methods;
duke@435 2373 static int _number_of_synchronized_methods;
duke@435 2374 static int _number_of_profiled_methods;
duke@435 2375 static int _number_of_bytecodes;
duke@435 2376 static int _parameter_size_profile[max_parameter_size];
duke@435 2377 static int _bytecodes_profile[Bytecodes::number_of_java_codes];
duke@435 2378
duke@435 2379 static void initialize() {
duke@435 2380 _number_of_methods = 0;
duke@435 2381 _number_of_final_methods = 0;
duke@435 2382 _number_of_static_methods = 0;
duke@435 2383 _number_of_native_methods = 0;
duke@435 2384 _number_of_synchronized_methods = 0;
duke@435 2385 _number_of_profiled_methods = 0;
duke@435 2386 _number_of_bytecodes = 0;
duke@435 2387 for (int i = 0; i < max_parameter_size ; i++) _parameter_size_profile[i] = 0;
duke@435 2388 for (int j = 0; j < Bytecodes::number_of_java_codes; j++) _bytecodes_profile [j] = 0;
duke@435 2389 };
duke@435 2390
duke@435 2391 static void do_method(methodOop m) {
duke@435 2392 _number_of_methods++;
duke@435 2393 // collect flag info
duke@435 2394 if (m->is_final() ) _number_of_final_methods++;
duke@435 2395 if (m->is_static() ) _number_of_static_methods++;
duke@435 2396 if (m->is_native() ) _number_of_native_methods++;
duke@435 2397 if (m->is_synchronized()) _number_of_synchronized_methods++;
duke@435 2398 if (m->method_data() != NULL) _number_of_profiled_methods++;
duke@435 2399 // collect parameter size info (add one for receiver, if any)
duke@435 2400 _parameter_size_profile[MIN2(m->size_of_parameters() + (m->is_static() ? 0 : 1), max_parameter_size - 1)]++;
duke@435 2401 // collect bytecodes info
duke@435 2402 {
duke@435 2403 Thread *thread = Thread::current();
duke@435 2404 HandleMark hm(thread);
duke@435 2405 BytecodeStream s(methodHandle(thread, m));
duke@435 2406 Bytecodes::Code c;
duke@435 2407 while ((c = s.next()) >= 0) {
duke@435 2408 _number_of_bytecodes++;
duke@435 2409 _bytecodes_profile[c]++;
duke@435 2410 }
duke@435 2411 }
duke@435 2412 }
duke@435 2413
duke@435 2414 public:
duke@435 2415 static void print() {
duke@435 2416 initialize();
duke@435 2417 SystemDictionary::methods_do(do_method);
duke@435 2418 // generate output
duke@435 2419 tty->cr();
duke@435 2420 tty->print_cr("Method statistics (static):");
duke@435 2421 // flag distribution
duke@435 2422 tty->cr();
duke@435 2423 tty->print_cr("%6d final methods %6.1f%%", _number_of_final_methods , _number_of_final_methods * 100.0F / _number_of_methods);
duke@435 2424 tty->print_cr("%6d static methods %6.1f%%", _number_of_static_methods , _number_of_static_methods * 100.0F / _number_of_methods);
duke@435 2425 tty->print_cr("%6d native methods %6.1f%%", _number_of_native_methods , _number_of_native_methods * 100.0F / _number_of_methods);
duke@435 2426 tty->print_cr("%6d synchronized methods %6.1f%%", _number_of_synchronized_methods, _number_of_synchronized_methods * 100.0F / _number_of_methods);
duke@435 2427 tty->print_cr("%6d profiled methods %6.1f%%", _number_of_profiled_methods, _number_of_profiled_methods * 100.0F / _number_of_methods);
duke@435 2428 // parameter size profile
duke@435 2429 tty->cr();
duke@435 2430 { int tot = 0;
duke@435 2431 int avg = 0;
duke@435 2432 for (int i = 0; i < max_parameter_size; i++) {
duke@435 2433 int n = _parameter_size_profile[i];
duke@435 2434 tot += n;
duke@435 2435 avg += n*i;
duke@435 2436 tty->print_cr("parameter size = %1d: %6d methods %5.1f%%", i, n, n * 100.0F / _number_of_methods);
duke@435 2437 }
duke@435 2438 assert(tot == _number_of_methods, "should be the same");
duke@435 2439 tty->print_cr(" %6d methods 100.0%%", _number_of_methods);
duke@435 2440 tty->print_cr("(average parameter size = %3.1f including receiver, if any)", (float)avg / _number_of_methods);
duke@435 2441 }
duke@435 2442 // bytecodes profile
duke@435 2443 tty->cr();
duke@435 2444 { int tot = 0;
duke@435 2445 for (int i = 0; i < Bytecodes::number_of_java_codes; i++) {
duke@435 2446 if (Bytecodes::is_defined(i)) {
duke@435 2447 Bytecodes::Code c = Bytecodes::cast(i);
duke@435 2448 int n = _bytecodes_profile[c];
duke@435 2449 tot += n;
duke@435 2450 tty->print_cr("%9d %7.3f%% %s", n, n * 100.0F / _number_of_bytecodes, Bytecodes::name(c));
duke@435 2451 }
duke@435 2452 }
duke@435 2453 assert(tot == _number_of_bytecodes, "should be the same");
duke@435 2454 tty->print_cr("%9d 100.000%%", _number_of_bytecodes);
duke@435 2455 }
duke@435 2456 tty->cr();
duke@435 2457 }
duke@435 2458 };
duke@435 2459
duke@435 2460 int MethodStatistics::_number_of_methods;
duke@435 2461 int MethodStatistics::_number_of_final_methods;
duke@435 2462 int MethodStatistics::_number_of_static_methods;
duke@435 2463 int MethodStatistics::_number_of_native_methods;
duke@435 2464 int MethodStatistics::_number_of_synchronized_methods;
duke@435 2465 int MethodStatistics::_number_of_profiled_methods;
duke@435 2466 int MethodStatistics::_number_of_bytecodes;
duke@435 2467 int MethodStatistics::_parameter_size_profile[MethodStatistics::max_parameter_size];
duke@435 2468 int MethodStatistics::_bytecodes_profile[Bytecodes::number_of_java_codes];
duke@435 2469
duke@435 2470
duke@435 2471 void SystemDictionary::print_method_statistics() {
duke@435 2472 MethodStatistics::print();
duke@435 2473 }
duke@435 2474
duke@435 2475 #endif // PRODUCT

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