1 /* 2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "jvm.h" 27 #include "aot/aotLoader.hpp" 28 #include "classfile/classFileParser.hpp" 29 #include "classfile/classFileStream.hpp" 30 #include "classfile/classLoader.hpp" 31 #include "classfile/classLoaderData.inline.hpp" 32 #include "classfile/javaClasses.hpp" 33 #include "classfile/moduleEntry.hpp" 34 #include "classfile/systemDictionary.hpp" 35 #include "classfile/systemDictionaryShared.hpp" 36 #include "classfile/verifier.hpp" 37 #include "classfile/vmSymbols.hpp" 38 #include "code/dependencyContext.hpp" 39 #include "compiler/compileBroker.hpp" 40 #include "gc/shared/collectedHeap.inline.hpp" 41 #include "interpreter/oopMapCache.hpp" 42 #include "interpreter/rewriter.hpp" 43 #include "jvmtifiles/jvmti.h" 44 #include "logging/log.hpp" 45 #include "logging/logMessage.hpp" 46 #include "logging/logStream.hpp" 47 #include "memory/allocation.inline.hpp" 48 #include "memory/heapInspection.hpp" 49 #include "memory/iterator.inline.hpp" 50 #include "memory/metadataFactory.hpp" 51 #include "memory/metaspaceClosure.hpp" 52 #include "memory/metaspaceShared.hpp" 53 #include "memory/oopFactory.hpp" 54 #include "memory/resourceArea.hpp" 55 #include "oops/fieldStreams.hpp" 56 #include "oops/instanceClassLoaderKlass.hpp" 57 #include "oops/instanceKlass.inline.hpp" 58 #include "oops/instanceMirrorKlass.hpp" 59 #include "oops/instanceOop.hpp" 60 #include "oops/klass.inline.hpp" 61 #include "oops/method.hpp" 62 #include "oops/oop.inline.hpp" 63 #include "oops/symbol.hpp" 64 #include "prims/jvmtiExport.hpp" 65 #include "prims/jvmtiRedefineClasses.hpp" 66 #include "prims/jvmtiThreadState.hpp" 67 #include "prims/methodComparator.hpp" 68 #include "runtime/atomic.hpp" 69 #include "runtime/fieldDescriptor.inline.hpp" 70 #include "runtime/handles.inline.hpp" 71 #include "runtime/javaCalls.hpp" 72 #include "runtime/mutexLocker.hpp" 73 #include "runtime/orderAccess.hpp" 74 #include "runtime/thread.inline.hpp" 75 #include "services/classLoadingService.hpp" 76 #include "services/threadService.hpp" 77 #include "utilities/dtrace.hpp" 78 #include "utilities/macros.hpp" 79 #include "utilities/stringUtils.hpp" 80 #ifdef COMPILER1 81 #include "c1/c1_Compiler.hpp" 82 #endif 83 #if INCLUDE_JFR 84 #include "jfr/jfrEvents.hpp" 85 #endif 86 87 88 #ifdef DTRACE_ENABLED 89 90 91 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED 92 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE 93 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT 94 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS 95 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED 96 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT 97 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR 98 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END 99 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \ 100 { \ 101 char* data = NULL; \ 102 int len = 0; \ 103 Symbol* clss_name = name(); \ 104 if (clss_name != NULL) { \ 105 data = (char*)clss_name->bytes(); \ 106 len = clss_name->utf8_length(); \ 107 } \ 108 HOTSPOT_CLASS_INITIALIZATION_##type( \ 109 data, len, (void*)class_loader(), thread_type); \ 110 } 111 112 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \ 113 { \ 114 char* data = NULL; \ 115 int len = 0; \ 116 Symbol* clss_name = name(); \ 117 if (clss_name != NULL) { \ 118 data = (char*)clss_name->bytes(); \ 119 len = clss_name->utf8_length(); \ 120 } \ 121 HOTSPOT_CLASS_INITIALIZATION_##type( \ 122 data, len, (void*)class_loader(), thread_type, wait); \ 123 } 124 125 #else // ndef DTRACE_ENABLED 126 127 #define DTRACE_CLASSINIT_PROBE(type, thread_type) 128 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) 129 130 #endif // ndef DTRACE_ENABLED 131 132 static inline bool is_class_loader(const Symbol* class_name, 133 const ClassFileParser& parser) { 134 assert(class_name != NULL, "invariant"); 135 136 if (class_name == vmSymbols::java_lang_ClassLoader()) { 137 return true; 138 } 139 140 if (SystemDictionary::ClassLoader_klass_loaded()) { 141 const Klass* const super_klass = parser.super_klass(); 142 if (super_klass != NULL) { 143 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) { 144 return true; 145 } 146 } 147 } 148 return false; 149 } 150 151 // called to verify that k is a member of this nest 152 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const { 153 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) { 154 if (log_is_enabled(Trace, class, nestmates)) { 155 ResourceMark rm(THREAD); 156 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s", 157 k->external_name(), this->external_name()); 158 } 159 return false; 160 } 161 162 if (log_is_enabled(Trace, class, nestmates)) { 163 ResourceMark rm(THREAD); 164 log_trace(class, nestmates)("Checking nest membership of %s in %s", 165 k->external_name(), this->external_name()); 166 } 167 168 // Check names first and if they match then check actual klass. This avoids 169 // resolving anything unnecessarily. 170 for (int i = 0; i < _nest_members->length(); i++) { 171 int cp_index = _nest_members->at(i); 172 Symbol* name = _constants->klass_name_at(cp_index); 173 if (name == k->name()) { 174 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index); 175 176 // names match so check actual klass - this may trigger class loading if 177 // it doesn't match (but that should be impossible) 178 Klass* k2 = _constants->klass_at(cp_index, CHECK_false); 179 if (k2 == k) { 180 log_trace(class, nestmates)("- class is listed as a nest member"); 181 return true; 182 } else { 183 // same name but different klass! 184 log_trace(class, nestmates)(" - klass comparison failed!"); 185 // can't have different classes for the same name, so we're done 186 return false; 187 } 188 } 189 } 190 log_trace(class, nestmates)("- class is NOT a nest member!"); 191 return false; 192 } 193 194 // Return nest-host class, resolving, validating and saving it if needed. 195 // In cases where this is called from a thread that can not do classloading 196 // (such as a native JIT thread) then we simply return NULL, which in turn 197 // causes the access check to return false. Such code will retry the access 198 // from a more suitable environment later. 199 InstanceKlass* InstanceKlass::nest_host(Symbol* validationException, TRAPS) { 200 InstanceKlass* nest_host_k = _nest_host; 201 if (nest_host_k == NULL) { 202 // need to resolve and save our nest-host class. This could be attempted 203 // concurrently but as the result is idempotent and we don't use the class 204 // then we do not need any synchronization beyond what is implicitly used 205 // during class loading. 206 if (_nest_host_index != 0) { // we have a real nest_host 207 // Before trying to resolve check if we're in a suitable context 208 if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) { 209 if (log_is_enabled(Trace, class, nestmates)) { 210 ResourceMark rm(THREAD); 211 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread", 212 this->external_name()); 213 } 214 return NULL; 215 } 216 217 if (log_is_enabled(Trace, class, nestmates)) { 218 ResourceMark rm(THREAD); 219 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s", 220 this->external_name(), 221 _constants->klass_name_at(_nest_host_index)->as_C_string()); 222 } 223 224 Klass* k = _constants->klass_at(_nest_host_index, THREAD); 225 if (HAS_PENDING_EXCEPTION) { 226 Handle exc_h = Handle(THREAD, PENDING_EXCEPTION); 227 if (exc_h->is_a(SystemDictionary::NoClassDefFoundError_klass())) { 228 // throw a new CDNFE with the original as its cause, and a clear msg 229 ResourceMark rm(THREAD); 230 char buf[200]; 231 CLEAR_PENDING_EXCEPTION; 232 jio_snprintf(buf, sizeof(buf), 233 "Unable to load nest-host class (%s) of %s", 234 _constants->klass_name_at(_nest_host_index)->as_C_string(), 235 this->external_name()); 236 log_trace(class, nestmates)("%s - NoClassDefFoundError", buf); 237 THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), buf, exc_h); 238 } 239 // All other exceptions pass through (OOME, StackOverflowError, LinkageErrors etc). 240 return NULL; 241 } 242 243 // A valid nest-host is an instance class in the current package that lists this 244 // class as a nest member. If any of these conditions are not met we post the 245 // requested exception type (if any) and return NULL 246 247 const char* error = NULL; 248 249 // JVMS 5.4.4 indicates package check comes first 250 if (is_same_class_package(k)) { 251 252 // Now check actual membership. We can't be a member if our "host" is 253 // not an instance class. 254 if (k->is_instance_klass()) { 255 nest_host_k = InstanceKlass::cast(k); 256 257 bool is_member = nest_host_k->has_nest_member(this, CHECK_NULL); 258 if (is_member) { 259 // save resolved nest-host value 260 _nest_host = nest_host_k; 261 262 if (log_is_enabled(Trace, class, nestmates)) { 263 ResourceMark rm(THREAD); 264 log_trace(class, nestmates)("Resolved nest-host of %s to %s", 265 this->external_name(), k->external_name()); 266 } 267 return nest_host_k; 268 } 269 } 270 error = "current type is not listed as a nest member"; 271 } else { 272 error = "types are in different packages"; 273 } 274 275 if (log_is_enabled(Trace, class, nestmates)) { 276 ResourceMark rm(THREAD); 277 log_trace(class, nestmates)("Type %s is not a nest member of resolved type %s: %s", 278 this->external_name(), 279 k->external_name(), 280 error); 281 } 282 283 if (validationException != NULL) { 284 ResourceMark rm(THREAD); 285 Exceptions::fthrow(THREAD_AND_LOCATION, 286 validationException, 287 "Type %s is not a nest member of %s: %s", 288 this->external_name(), 289 k->external_name(), 290 error 291 ); 292 } 293 return NULL; 294 } else { 295 if (log_is_enabled(Trace, class, nestmates)) { 296 ResourceMark rm(THREAD); 297 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self", 298 this->external_name()); 299 } 300 // save resolved nest-host value 301 return (_nest_host = this); 302 } 303 } 304 return nest_host_k; 305 } 306 307 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host, 308 // or we are k's nest_host - all of which is covered by comparing the two 309 // resolved_nest_hosts 310 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) { 311 312 assert(this != k, "this should be handled by higher-level code"); 313 314 // Per JVMS 5.4.4 we first resolve and validate the current class, then 315 // the target class k. Resolution exceptions will be passed on by upper 316 // layers. IncompatibleClassChangeErrors from membership validation failures 317 // will also be passed through. 318 319 Symbol* icce = vmSymbols::java_lang_IncompatibleClassChangeError(); 320 InstanceKlass* cur_host = nest_host(icce, CHECK_false); 321 if (cur_host == NULL) { 322 return false; 323 } 324 325 Klass* k_nest_host = k->nest_host(icce, CHECK_false); 326 if (k_nest_host == NULL) { 327 return false; 328 } 329 330 bool access = (cur_host == k_nest_host); 331 332 if (log_is_enabled(Trace, class, nestmates)) { 333 ResourceMark rm(THREAD); 334 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s", 335 this->external_name(), 336 access ? "" : "NOT ", 337 k->external_name()); 338 } 339 340 return access; 341 } 342 343 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) { 344 const int size = InstanceKlass::size(parser.vtable_size(), 345 parser.itable_size(), 346 nonstatic_oop_map_size(parser.total_oop_map_count()), 347 parser.is_interface(), 348 parser.is_unsafe_anonymous(), 349 should_store_fingerprint(parser.is_unsafe_anonymous())); 350 351 const Symbol* const class_name = parser.class_name(); 352 assert(class_name != NULL, "invariant"); 353 ClassLoaderData* loader_data = parser.loader_data(); 354 assert(loader_data != NULL, "invariant"); 355 356 InstanceKlass* ik; 357 358 // Allocation 359 if (REF_NONE == parser.reference_type()) { 360 if (class_name == vmSymbols::java_lang_Class()) { 361 // mirror 362 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser); 363 } 364 else if (is_class_loader(class_name, parser)) { 365 // class loader 366 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser); 367 } else { 368 // normal 369 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other); 370 } 371 } else { 372 // reference 373 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser); 374 } 375 376 // Check for pending exception before adding to the loader data and incrementing 377 // class count. Can get OOM here. 378 if (HAS_PENDING_EXCEPTION) { 379 return NULL; 380 } 381 382 return ik; 383 } 384 385 386 // copy method ordering from resource area to Metaspace 387 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) { 388 if (m != NULL) { 389 // allocate a new array and copy contents (memcpy?) 390 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK); 391 for (int i = 0; i < m->length(); i++) { 392 _method_ordering->at_put(i, m->at(i)); 393 } 394 } else { 395 _method_ordering = Universe::the_empty_int_array(); 396 } 397 } 398 399 // create a new array of vtable_indices for default methods 400 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) { 401 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL); 402 assert(default_vtable_indices() == NULL, "only create once"); 403 set_default_vtable_indices(vtable_indices); 404 return vtable_indices; 405 } 406 407 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) : 408 Klass(id), 409 _nest_members(NULL), 410 _nest_host_index(0), 411 _nest_host(NULL), 412 _static_field_size(parser.static_field_size()), 413 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())), 414 _itable_len(parser.itable_size()), 415 _reference_type(parser.reference_type()) { 416 set_vtable_length(parser.vtable_size()); 417 set_kind(kind); 418 set_access_flags(parser.access_flags()); 419 set_is_unsafe_anonymous(parser.is_unsafe_anonymous()); 420 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(), 421 false)); 422 423 assert(NULL == _methods, "underlying memory not zeroed?"); 424 assert(is_instance_klass(), "is layout incorrect?"); 425 assert(size_helper() == parser.layout_size(), "incorrect size_helper?"); 426 } 427 428 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data, 429 Array<Method*>* methods) { 430 if (methods != NULL && methods != Universe::the_empty_method_array() && 431 !methods->is_shared()) { 432 for (int i = 0; i < methods->length(); i++) { 433 Method* method = methods->at(i); 434 if (method == NULL) continue; // maybe null if error processing 435 // Only want to delete methods that are not executing for RedefineClasses. 436 // The previous version will point to them so they're not totally dangling 437 assert (!method->on_stack(), "shouldn't be called with methods on stack"); 438 MetadataFactory::free_metadata(loader_data, method); 439 } 440 MetadataFactory::free_array<Method*>(loader_data, methods); 441 } 442 } 443 444 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data, 445 const Klass* super_klass, 446 Array<InstanceKlass*>* local_interfaces, 447 Array<InstanceKlass*>* transitive_interfaces) { 448 // Only deallocate transitive interfaces if not empty, same as super class 449 // or same as local interfaces. See code in parseClassFile. 450 Array<InstanceKlass*>* ti = transitive_interfaces; 451 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) { 452 // check that the interfaces don't come from super class 453 Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL : 454 InstanceKlass::cast(super_klass)->transitive_interfaces(); 455 if (ti != sti && ti != NULL && !ti->is_shared()) { 456 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti); 457 } 458 } 459 460 // local interfaces can be empty 461 if (local_interfaces != Universe::the_empty_instance_klass_array() && 462 local_interfaces != NULL && !local_interfaces->is_shared()) { 463 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces); 464 } 465 } 466 467 // This function deallocates the metadata and C heap pointers that the 468 // InstanceKlass points to. 469 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) { 470 471 // Orphan the mirror first, CMS thinks it's still live. 472 if (java_mirror() != NULL) { 473 java_lang_Class::set_klass(java_mirror(), NULL); 474 } 475 476 // Also remove mirror from handles 477 loader_data->remove_handle(_java_mirror); 478 479 // Need to take this class off the class loader data list. 480 loader_data->remove_class(this); 481 482 // The array_klass for this class is created later, after error handling. 483 // For class redefinition, we keep the original class so this scratch class 484 // doesn't have an array class. Either way, assert that there is nothing 485 // to deallocate. 486 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet"); 487 488 // Release C heap allocated data that this might point to, which includes 489 // reference counting symbol names. 490 release_C_heap_structures(); 491 492 deallocate_methods(loader_data, methods()); 493 set_methods(NULL); 494 495 if (method_ordering() != NULL && 496 method_ordering() != Universe::the_empty_int_array() && 497 !method_ordering()->is_shared()) { 498 MetadataFactory::free_array<int>(loader_data, method_ordering()); 499 } 500 set_method_ordering(NULL); 501 502 // default methods can be empty 503 if (default_methods() != NULL && 504 default_methods() != Universe::the_empty_method_array() && 505 !default_methods()->is_shared()) { 506 MetadataFactory::free_array<Method*>(loader_data, default_methods()); 507 } 508 // Do NOT deallocate the default methods, they are owned by superinterfaces. 509 set_default_methods(NULL); 510 511 // default methods vtable indices can be empty 512 if (default_vtable_indices() != NULL && 513 !default_vtable_indices()->is_shared()) { 514 MetadataFactory::free_array<int>(loader_data, default_vtable_indices()); 515 } 516 set_default_vtable_indices(NULL); 517 518 519 // This array is in Klass, but remove it with the InstanceKlass since 520 // this place would be the only caller and it can share memory with transitive 521 // interfaces. 522 if (secondary_supers() != NULL && 523 secondary_supers() != Universe::the_empty_klass_array() && 524 // see comments in compute_secondary_supers about the following cast 525 (address)(secondary_supers()) != (address)(transitive_interfaces()) && 526 !secondary_supers()->is_shared()) { 527 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers()); 528 } 529 set_secondary_supers(NULL); 530 531 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces()); 532 set_transitive_interfaces(NULL); 533 set_local_interfaces(NULL); 534 535 if (fields() != NULL && !fields()->is_shared()) { 536 MetadataFactory::free_array<jushort>(loader_data, fields()); 537 } 538 set_fields(NULL, 0); 539 540 // If a method from a redefined class is using this constant pool, don't 541 // delete it, yet. The new class's previous version will point to this. 542 if (constants() != NULL) { 543 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack"); 544 if (!constants()->is_shared()) { 545 MetadataFactory::free_metadata(loader_data, constants()); 546 } 547 // Delete any cached resolution errors for the constant pool 548 SystemDictionary::delete_resolution_error(constants()); 549 550 set_constants(NULL); 551 } 552 553 if (inner_classes() != NULL && 554 inner_classes() != Universe::the_empty_short_array() && 555 !inner_classes()->is_shared()) { 556 MetadataFactory::free_array<jushort>(loader_data, inner_classes()); 557 } 558 set_inner_classes(NULL); 559 560 if (nest_members() != NULL && 561 nest_members() != Universe::the_empty_short_array() && 562 !nest_members()->is_shared()) { 563 MetadataFactory::free_array<jushort>(loader_data, nest_members()); 564 } 565 set_nest_members(NULL); 566 567 // We should deallocate the Annotations instance if it's not in shared spaces. 568 if (annotations() != NULL && !annotations()->is_shared()) { 569 MetadataFactory::free_metadata(loader_data, annotations()); 570 } 571 set_annotations(NULL); 572 } 573 574 bool InstanceKlass::should_be_initialized() const { 575 return !is_initialized(); 576 } 577 578 klassItable InstanceKlass::itable() const { 579 return klassItable(const_cast<InstanceKlass*>(this)); 580 } 581 582 void InstanceKlass::eager_initialize(Thread *thread) { 583 if (!EagerInitialization) return; 584 585 if (this->is_not_initialized()) { 586 // abort if the the class has a class initializer 587 if (this->class_initializer() != NULL) return; 588 589 // abort if it is java.lang.Object (initialization is handled in genesis) 590 Klass* super_klass = super(); 591 if (super_klass == NULL) return; 592 593 // abort if the super class should be initialized 594 if (!InstanceKlass::cast(super_klass)->is_initialized()) return; 595 596 // call body to expose the this pointer 597 eager_initialize_impl(); 598 } 599 } 600 601 // JVMTI spec thinks there are signers and protection domain in the 602 // instanceKlass. These accessors pretend these fields are there. 603 // The hprof specification also thinks these fields are in InstanceKlass. 604 oop InstanceKlass::protection_domain() const { 605 // return the protection_domain from the mirror 606 return java_lang_Class::protection_domain(java_mirror()); 607 } 608 609 // To remove these from requires an incompatible change and CCC request. 610 objArrayOop InstanceKlass::signers() const { 611 // return the signers from the mirror 612 return java_lang_Class::signers(java_mirror()); 613 } 614 615 oop InstanceKlass::init_lock() const { 616 // return the init lock from the mirror 617 oop lock = java_lang_Class::init_lock(java_mirror()); 618 // Prevent reordering with any access of initialization state 619 OrderAccess::loadload(); 620 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state 621 "only fully initialized state can have a null lock"); 622 return lock; 623 } 624 625 // Set the initialization lock to null so the object can be GC'ed. Any racing 626 // threads to get this lock will see a null lock and will not lock. 627 // That's okay because they all check for initialized state after getting 628 // the lock and return. 629 void InstanceKlass::fence_and_clear_init_lock() { 630 // make sure previous stores are all done, notably the init_state. 631 OrderAccess::storestore(); 632 java_lang_Class::set_init_lock(java_mirror(), NULL); 633 assert(!is_not_initialized(), "class must be initialized now"); 634 } 635 636 void InstanceKlass::eager_initialize_impl() { 637 EXCEPTION_MARK; 638 HandleMark hm(THREAD); 639 Handle h_init_lock(THREAD, init_lock()); 640 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL); 641 642 // abort if someone beat us to the initialization 643 if (!is_not_initialized()) return; // note: not equivalent to is_initialized() 644 645 ClassState old_state = init_state(); 646 link_class_impl(THREAD); 647 if (HAS_PENDING_EXCEPTION) { 648 CLEAR_PENDING_EXCEPTION; 649 // Abort if linking the class throws an exception. 650 651 // Use a test to avoid redundantly resetting the state if there's 652 // no change. Set_init_state() asserts that state changes make 653 // progress, whereas here we might just be spinning in place. 654 if (old_state != _init_state) 655 set_init_state(old_state); 656 } else { 657 // linking successfull, mark class as initialized 658 set_init_state(fully_initialized); 659 fence_and_clear_init_lock(); 660 // trace 661 if (log_is_enabled(Info, class, init)) { 662 ResourceMark rm(THREAD); 663 log_info(class, init)("[Initialized %s without side effects]", external_name()); 664 } 665 } 666 } 667 668 669 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization 670 // process. The step comments refers to the procedure described in that section. 671 // Note: implementation moved to static method to expose the this pointer. 672 void InstanceKlass::initialize(TRAPS) { 673 if (this->should_be_initialized()) { 674 initialize_impl(CHECK); 675 // Note: at this point the class may be initialized 676 // OR it may be in the state of being initialized 677 // in case of recursive initialization! 678 } else { 679 assert(is_initialized(), "sanity check"); 680 } 681 } 682 683 684 bool InstanceKlass::verify_code(TRAPS) { 685 // 1) Verify the bytecodes 686 return Verifier::verify(this, should_verify_class(), THREAD); 687 } 688 689 void InstanceKlass::link_class(TRAPS) { 690 assert(is_loaded(), "must be loaded"); 691 if (!is_linked()) { 692 link_class_impl(CHECK); 693 } 694 } 695 696 // Called to verify that a class can link during initialization, without 697 // throwing a VerifyError. 698 bool InstanceKlass::link_class_or_fail(TRAPS) { 699 assert(is_loaded(), "must be loaded"); 700 if (!is_linked()) { 701 link_class_impl(CHECK_false); 702 } 703 return is_linked(); 704 } 705 706 bool InstanceKlass::link_class_impl(TRAPS) { 707 if (DumpSharedSpaces && is_in_error_state()) { 708 // This is for CDS dumping phase only -- we use the in_error_state to indicate that 709 // the class has failed verification. Throwing the NoClassDefFoundError here is just 710 // a convenient way to stop repeat attempts to verify the same (bad) class. 711 // 712 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown 713 // if we are executing Java code. This is not a problem for CDS dumping phase since 714 // it doesn't execute any Java code. 715 ResourceMark rm(THREAD); 716 Exceptions::fthrow(THREAD_AND_LOCATION, 717 vmSymbols::java_lang_NoClassDefFoundError(), 718 "Class %s, or one of its supertypes, failed class initialization", 719 external_name()); 720 return false; 721 } 722 // return if already verified 723 if (is_linked()) { 724 return true; 725 } 726 727 // Timing 728 // timer handles recursion 729 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl"); 730 JavaThread* jt = (JavaThread*)THREAD; 731 732 // link super class before linking this class 733 Klass* super_klass = super(); 734 if (super_klass != NULL) { 735 if (super_klass->is_interface()) { // check if super class is an interface 736 ResourceMark rm(THREAD); 737 Exceptions::fthrow( 738 THREAD_AND_LOCATION, 739 vmSymbols::java_lang_IncompatibleClassChangeError(), 740 "class %s has interface %s as super class", 741 external_name(), 742 super_klass->external_name() 743 ); 744 return false; 745 } 746 747 InstanceKlass* ik_super = InstanceKlass::cast(super_klass); 748 ik_super->link_class_impl(CHECK_false); 749 } 750 751 // link all interfaces implemented by this class before linking this class 752 Array<InstanceKlass*>* interfaces = local_interfaces(); 753 int num_interfaces = interfaces->length(); 754 for (int index = 0; index < num_interfaces; index++) { 755 InstanceKlass* interk = interfaces->at(index); 756 interk->link_class_impl(CHECK_false); 757 } 758 759 // in case the class is linked in the process of linking its superclasses 760 if (is_linked()) { 761 return true; 762 } 763 764 // trace only the link time for this klass that includes 765 // the verification time 766 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(), 767 ClassLoader::perf_class_link_selftime(), 768 ClassLoader::perf_classes_linked(), 769 jt->get_thread_stat()->perf_recursion_counts_addr(), 770 jt->get_thread_stat()->perf_timers_addr(), 771 PerfClassTraceTime::CLASS_LINK); 772 773 // verification & rewriting 774 { 775 HandleMark hm(THREAD); 776 Handle h_init_lock(THREAD, init_lock()); 777 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL); 778 // rewritten will have been set if loader constraint error found 779 // on an earlier link attempt 780 // don't verify or rewrite if already rewritten 781 // 782 783 if (!is_linked()) { 784 if (!is_rewritten()) { 785 { 786 bool verify_ok = verify_code(THREAD); 787 if (!verify_ok) { 788 return false; 789 } 790 } 791 792 // Just in case a side-effect of verify linked this class already 793 // (which can sometimes happen since the verifier loads classes 794 // using custom class loaders, which are free to initialize things) 795 if (is_linked()) { 796 return true; 797 } 798 799 // also sets rewritten 800 rewrite_class(CHECK_false); 801 } else if (is_shared()) { 802 SystemDictionaryShared::check_verification_constraints(this, CHECK_false); 803 } 804 805 // relocate jsrs and link methods after they are all rewritten 806 link_methods(CHECK_false); 807 808 // Initialize the vtable and interface table after 809 // methods have been rewritten since rewrite may 810 // fabricate new Method*s. 811 // also does loader constraint checking 812 // 813 // initialize_vtable and initialize_itable need to be rerun for 814 // a shared class if the class is not loaded by the NULL classloader. 815 ClassLoaderData * loader_data = class_loader_data(); 816 if (!(is_shared() && 817 loader_data->is_the_null_class_loader_data())) { 818 vtable().initialize_vtable(true, CHECK_false); 819 itable().initialize_itable(true, CHECK_false); 820 } 821 #ifdef ASSERT 822 else { 823 vtable().verify(tty, true); 824 // In case itable verification is ever added. 825 // itable().verify(tty, true); 826 } 827 #endif 828 set_init_state(linked); 829 if (JvmtiExport::should_post_class_prepare()) { 830 Thread *thread = THREAD; 831 assert(thread->is_Java_thread(), "thread->is_Java_thread()"); 832 JvmtiExport::post_class_prepare((JavaThread *) thread, this); 833 } 834 } 835 } 836 return true; 837 } 838 839 // Rewrite the byte codes of all of the methods of a class. 840 // The rewriter must be called exactly once. Rewriting must happen after 841 // verification but before the first method of the class is executed. 842 void InstanceKlass::rewrite_class(TRAPS) { 843 assert(is_loaded(), "must be loaded"); 844 if (is_rewritten()) { 845 assert(is_shared(), "rewriting an unshared class?"); 846 return; 847 } 848 Rewriter::rewrite(this, CHECK); 849 set_rewritten(); 850 } 851 852 // Now relocate and link method entry points after class is rewritten. 853 // This is outside is_rewritten flag. In case of an exception, it can be 854 // executed more than once. 855 void InstanceKlass::link_methods(TRAPS) { 856 int len = methods()->length(); 857 for (int i = len-1; i >= 0; i--) { 858 methodHandle m(THREAD, methods()->at(i)); 859 860 // Set up method entry points for compiler and interpreter . 861 m->link_method(m, CHECK); 862 } 863 } 864 865 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access) 866 void InstanceKlass::initialize_super_interfaces(TRAPS) { 867 assert (has_nonstatic_concrete_methods(), "caller should have checked this"); 868 for (int i = 0; i < local_interfaces()->length(); ++i) { 869 InstanceKlass* ik = local_interfaces()->at(i); 870 871 // Initialization is depth first search ie. we start with top of the inheritance tree 872 // has_nonstatic_concrete_methods drives searching superinterfaces since it 873 // means has_nonstatic_concrete_methods in its superinterface hierarchy 874 if (ik->has_nonstatic_concrete_methods()) { 875 ik->initialize_super_interfaces(CHECK); 876 } 877 878 // Only initialize() interfaces that "declare" concrete methods. 879 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) { 880 ik->initialize(CHECK); 881 } 882 } 883 } 884 885 void InstanceKlass::initialize_impl(TRAPS) { 886 HandleMark hm(THREAD); 887 888 // Make sure klass is linked (verified) before initialization 889 // A class could already be verified, since it has been reflected upon. 890 link_class(CHECK); 891 892 DTRACE_CLASSINIT_PROBE(required, -1); 893 894 bool wait = false; 895 896 // refer to the JVM book page 47 for description of steps 897 // Step 1 898 { 899 Handle h_init_lock(THREAD, init_lock()); 900 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL); 901 902 Thread *self = THREAD; // it's passed the current thread 903 904 // Step 2 905 // If we were to use wait() instead of waitInterruptibly() then 906 // we might end up throwing IE from link/symbol resolution sites 907 // that aren't expected to throw. This would wreak havoc. See 6320309. 908 while(is_being_initialized() && !is_reentrant_initialization(self)) { 909 wait = true; 910 ol.waitUninterruptibly(CHECK); 911 } 912 913 // Step 3 914 if (is_being_initialized() && is_reentrant_initialization(self)) { 915 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait); 916 return; 917 } 918 919 // Step 4 920 if (is_initialized()) { 921 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait); 922 return; 923 } 924 925 // Step 5 926 if (is_in_error_state()) { 927 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait); 928 ResourceMark rm(THREAD); 929 const char* desc = "Could not initialize class "; 930 const char* className = external_name(); 931 size_t msglen = strlen(desc) + strlen(className) + 1; 932 char* message = NEW_RESOURCE_ARRAY(char, msglen); 933 if (NULL == message) { 934 // Out of memory: can't create detailed error message 935 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className); 936 } else { 937 jio_snprintf(message, msglen, "%s%s", desc, className); 938 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message); 939 } 940 } 941 942 // Step 6 943 set_init_state(being_initialized); 944 set_init_thread(self); 945 } 946 947 // Step 7 948 // Next, if C is a class rather than an interface, initialize it's super class and super 949 // interfaces. 950 if (!is_interface()) { 951 Klass* super_klass = super(); 952 if (super_klass != NULL && super_klass->should_be_initialized()) { 953 super_klass->initialize(THREAD); 954 } 955 // If C implements any interface that declares a non-static, concrete method, 956 // the initialization of C triggers initialization of its super interfaces. 957 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and 958 // having a superinterface that declares, non-static, concrete methods 959 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) { 960 initialize_super_interfaces(THREAD); 961 } 962 963 // If any exceptions, complete abruptly, throwing the same exception as above. 964 if (HAS_PENDING_EXCEPTION) { 965 Handle e(THREAD, PENDING_EXCEPTION); 966 CLEAR_PENDING_EXCEPTION; 967 { 968 EXCEPTION_MARK; 969 // Locks object, set state, and notify all waiting threads 970 set_initialization_state_and_notify(initialization_error, THREAD); 971 CLEAR_PENDING_EXCEPTION; 972 } 973 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait); 974 THROW_OOP(e()); 975 } 976 } 977 978 979 // Look for aot compiled methods for this klass, including class initializer. 980 AOTLoader::load_for_klass(this, THREAD); 981 982 // Step 8 983 { 984 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl"); 985 JavaThread* jt = (JavaThread*)THREAD; 986 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait); 987 // Timer includes any side effects of class initialization (resolution, 988 // etc), but not recursive entry into call_class_initializer(). 989 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(), 990 ClassLoader::perf_class_init_selftime(), 991 ClassLoader::perf_classes_inited(), 992 jt->get_thread_stat()->perf_recursion_counts_addr(), 993 jt->get_thread_stat()->perf_timers_addr(), 994 PerfClassTraceTime::CLASS_CLINIT); 995 call_class_initializer(THREAD); 996 } 997 998 // Step 9 999 if (!HAS_PENDING_EXCEPTION) { 1000 set_initialization_state_and_notify(fully_initialized, CHECK); 1001 { 1002 debug_only(vtable().verify(tty, true);) 1003 } 1004 } 1005 else { 1006 // Step 10 and 11 1007 Handle e(THREAD, PENDING_EXCEPTION); 1008 CLEAR_PENDING_EXCEPTION; 1009 // JVMTI has already reported the pending exception 1010 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError 1011 JvmtiExport::clear_detected_exception((JavaThread*)THREAD); 1012 { 1013 EXCEPTION_MARK; 1014 set_initialization_state_and_notify(initialization_error, THREAD); 1015 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below 1016 // JVMTI has already reported the pending exception 1017 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError 1018 JvmtiExport::clear_detected_exception((JavaThread*)THREAD); 1019 } 1020 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait); 1021 if (e->is_a(SystemDictionary::Error_klass())) { 1022 THROW_OOP(e()); 1023 } else { 1024 JavaCallArguments args(e); 1025 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(), 1026 vmSymbols::throwable_void_signature(), 1027 &args); 1028 } 1029 } 1030 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait); 1031 } 1032 1033 1034 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) { 1035 Handle h_init_lock(THREAD, init_lock()); 1036 if (h_init_lock() != NULL) { 1037 ObjectLocker ol(h_init_lock, THREAD); 1038 set_init_state(state); 1039 fence_and_clear_init_lock(); 1040 ol.notify_all(CHECK); 1041 } else { 1042 assert(h_init_lock() != NULL, "The initialization state should never be set twice"); 1043 set_init_state(state); 1044 } 1045 } 1046 1047 Klass* InstanceKlass::implementor() const { 1048 assert_locked_or_safepoint(Compile_lock); 1049 Klass** k = adr_implementor(); 1050 if (k == NULL) { 1051 return NULL; 1052 } else { 1053 return *k; 1054 } 1055 } 1056 1057 void InstanceKlass::set_implementor(Klass* k) { 1058 assert_lock_strong(Compile_lock); 1059 assert(is_interface(), "not interface"); 1060 Klass** addr = adr_implementor(); 1061 assert(addr != NULL, "null addr"); 1062 if (addr != NULL) { 1063 *addr = k; 1064 } 1065 } 1066 1067 int InstanceKlass::nof_implementors() const { 1068 assert_lock_strong(Compile_lock); 1069 Klass* k = implementor(); 1070 if (k == NULL) { 1071 return 0; 1072 } else if (k != this) { 1073 return 1; 1074 } else { 1075 return 2; 1076 } 1077 } 1078 1079 // The embedded _implementor field can only record one implementor. 1080 // When there are more than one implementors, the _implementor field 1081 // is set to the interface Klass* itself. Following are the possible 1082 // values for the _implementor field: 1083 // NULL - no implementor 1084 // implementor Klass* - one implementor 1085 // self - more than one implementor 1086 // 1087 // The _implementor field only exists for interfaces. 1088 void InstanceKlass::add_implementor(Klass* k) { 1089 assert_lock_strong(Compile_lock); 1090 assert(is_interface(), "not interface"); 1091 // Filter out my subinterfaces. 1092 // (Note: Interfaces are never on the subklass list.) 1093 if (InstanceKlass::cast(k)->is_interface()) return; 1094 1095 // Filter out subclasses whose supers already implement me. 1096 // (Note: CHA must walk subclasses of direct implementors 1097 // in order to locate indirect implementors.) 1098 Klass* sk = k->super(); 1099 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this)) 1100 // We only need to check one immediate superclass, since the 1101 // implements_interface query looks at transitive_interfaces. 1102 // Any supers of the super have the same (or fewer) transitive_interfaces. 1103 return; 1104 1105 Klass* ik = implementor(); 1106 if (ik == NULL) { 1107 set_implementor(k); 1108 } else if (ik != this) { 1109 // There is already an implementor. Use itself as an indicator of 1110 // more than one implementors. 1111 set_implementor(this); 1112 } 1113 1114 // The implementor also implements the transitive_interfaces 1115 for (int index = 0; index < local_interfaces()->length(); index++) { 1116 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k); 1117 } 1118 } 1119 1120 void InstanceKlass::init_implementor() { 1121 if (is_interface()) { 1122 set_implementor(NULL); 1123 } 1124 } 1125 1126 1127 void InstanceKlass::process_interfaces(Thread *thread) { 1128 // link this class into the implementors list of every interface it implements 1129 for (int i = local_interfaces()->length() - 1; i >= 0; i--) { 1130 assert(local_interfaces()->at(i)->is_klass(), "must be a klass"); 1131 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i)); 1132 assert(interf->is_interface(), "expected interface"); 1133 interf->add_implementor(this); 1134 } 1135 } 1136 1137 bool InstanceKlass::can_be_primary_super_slow() const { 1138 if (is_interface()) 1139 return false; 1140 else 1141 return Klass::can_be_primary_super_slow(); 1142 } 1143 1144 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots, 1145 Array<InstanceKlass*>* transitive_interfaces) { 1146 // The secondaries are the implemented interfaces. 1147 Array<InstanceKlass*>* interfaces = transitive_interfaces; 1148 int num_secondaries = num_extra_slots + interfaces->length(); 1149 if (num_secondaries == 0) { 1150 // Must share this for correct bootstrapping! 1151 set_secondary_supers(Universe::the_empty_klass_array()); 1152 return NULL; 1153 } else if (num_extra_slots == 0) { 1154 // The secondary super list is exactly the same as the transitive interfaces, so 1155 // let's use it instead of making a copy. 1156 // Redefine classes has to be careful not to delete this! 1157 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>, 1158 // (but it's safe to do here because we won't write into _secondary_supers from this point on). 1159 set_secondary_supers((Array<Klass*>*)(address)interfaces); 1160 return NULL; 1161 } else { 1162 // Copy transitive interfaces to a temporary growable array to be constructed 1163 // into the secondary super list with extra slots. 1164 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length()); 1165 for (int i = 0; i < interfaces->length(); i++) { 1166 secondaries->push(interfaces->at(i)); 1167 } 1168 return secondaries; 1169 } 1170 } 1171 1172 bool InstanceKlass::compute_is_subtype_of(Klass* k) { 1173 if (k->is_interface()) { 1174 return implements_interface(k); 1175 } else { 1176 return Klass::compute_is_subtype_of(k); 1177 } 1178 } 1179 1180 bool InstanceKlass::implements_interface(Klass* k) const { 1181 if (this == k) return true; 1182 assert(k->is_interface(), "should be an interface class"); 1183 for (int i = 0; i < transitive_interfaces()->length(); i++) { 1184 if (transitive_interfaces()->at(i) == k) { 1185 return true; 1186 } 1187 } 1188 return false; 1189 } 1190 1191 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const { 1192 // Verify direct super interface 1193 if (this == k) return true; 1194 assert(k->is_interface(), "should be an interface class"); 1195 for (int i = 0; i < local_interfaces()->length(); i++) { 1196 if (local_interfaces()->at(i) == k) { 1197 return true; 1198 } 1199 } 1200 return false; 1201 } 1202 1203 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) { 1204 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL); 1205 int size = objArrayOopDesc::object_size(length); 1206 Klass* ak = array_klass(n, CHECK_NULL); 1207 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length, 1208 /* do_zero */ true, CHECK_NULL); 1209 return o; 1210 } 1211 1212 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) { 1213 if (TraceFinalizerRegistration) { 1214 tty->print("Registered "); 1215 i->print_value_on(tty); 1216 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i)); 1217 } 1218 instanceHandle h_i(THREAD, i); 1219 // Pass the handle as argument, JavaCalls::call expects oop as jobjects 1220 JavaValue result(T_VOID); 1221 JavaCallArguments args(h_i); 1222 methodHandle mh (THREAD, Universe::finalizer_register_method()); 1223 JavaCalls::call(&result, mh, &args, CHECK_NULL); 1224 return h_i(); 1225 } 1226 1227 instanceOop InstanceKlass::allocate_instance(TRAPS) { 1228 bool has_finalizer_flag = has_finalizer(); // Query before possible GC 1229 int size = size_helper(); // Query before forming handle. 1230 1231 instanceOop i; 1232 1233 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL); 1234 if (has_finalizer_flag && !RegisterFinalizersAtInit) { 1235 i = register_finalizer(i, CHECK_NULL); 1236 } 1237 return i; 1238 } 1239 1240 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) { 1241 return instanceHandle(THREAD, allocate_instance(THREAD)); 1242 } 1243 1244 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) { 1245 if (is_interface() || is_abstract()) { 1246 ResourceMark rm(THREAD); 1247 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() 1248 : vmSymbols::java_lang_InstantiationException(), external_name()); 1249 } 1250 if (this == SystemDictionary::Class_klass()) { 1251 ResourceMark rm(THREAD); 1252 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError() 1253 : vmSymbols::java_lang_IllegalAccessException(), external_name()); 1254 } 1255 } 1256 1257 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) { 1258 // Need load-acquire for lock-free read 1259 if (array_klasses_acquire() == NULL) { 1260 if (or_null) return NULL; 1261 1262 ResourceMark rm; 1263 JavaThread *jt = (JavaThread *)THREAD; 1264 { 1265 // Atomic creation of array_klasses 1266 MutexLocker mc(Compile_lock, THREAD); // for vtables 1267 MutexLocker ma(MultiArray_lock, THREAD); 1268 1269 // Check if update has already taken place 1270 if (array_klasses() == NULL) { 1271 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL); 1272 // use 'release' to pair with lock-free load 1273 release_set_array_klasses(k); 1274 } 1275 } 1276 } 1277 // _this will always be set at this point 1278 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses(); 1279 if (or_null) { 1280 return oak->array_klass_or_null(n); 1281 } 1282 return oak->array_klass(n, THREAD); 1283 } 1284 1285 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) { 1286 return array_klass_impl(or_null, 1, THREAD); 1287 } 1288 1289 static int call_class_initializer_counter = 0; // for debugging 1290 1291 Method* InstanceKlass::class_initializer() const { 1292 Method* clinit = find_method( 1293 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature()); 1294 if (clinit != NULL && clinit->has_valid_initializer_flags()) { 1295 return clinit; 1296 } 1297 return NULL; 1298 } 1299 1300 void InstanceKlass::call_class_initializer(TRAPS) { 1301 if (ReplayCompiles && 1302 (ReplaySuppressInitializers == 1 || 1303 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) { 1304 // Hide the existence of the initializer for the purpose of replaying the compile 1305 return; 1306 } 1307 1308 methodHandle h_method(THREAD, class_initializer()); 1309 assert(!is_initialized(), "we cannot initialize twice"); 1310 LogTarget(Info, class, init) lt; 1311 if (lt.is_enabled()) { 1312 ResourceMark rm; 1313 LogStream ls(lt); 1314 ls.print("%d Initializing ", call_class_initializer_counter++); 1315 name()->print_value_on(&ls); 1316 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this)); 1317 } 1318 if (h_method() != NULL) { 1319 JavaCallArguments args; // No arguments 1320 JavaValue result(T_VOID); 1321 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args) 1322 } 1323 } 1324 1325 1326 void InstanceKlass::mask_for(const methodHandle& method, int bci, 1327 InterpreterOopMap* entry_for) { 1328 // Lazily create the _oop_map_cache at first request 1329 // Lock-free access requires load_acquire. 1330 OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache); 1331 if (oop_map_cache == NULL) { 1332 MutexLocker x(OopMapCacheAlloc_lock); 1333 // Check if _oop_map_cache was allocated while we were waiting for this lock 1334 if ((oop_map_cache = _oop_map_cache) == NULL) { 1335 oop_map_cache = new OopMapCache(); 1336 // Ensure _oop_map_cache is stable, since it is examined without a lock 1337 OrderAccess::release_store(&_oop_map_cache, oop_map_cache); 1338 } 1339 } 1340 // _oop_map_cache is constant after init; lookup below does its own locking. 1341 oop_map_cache->lookup(method, bci, entry_for); 1342 } 1343 1344 1345 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 1346 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 1347 Symbol* f_name = fs.name(); 1348 Symbol* f_sig = fs.signature(); 1349 if (f_name == name && f_sig == sig) { 1350 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index()); 1351 return true; 1352 } 1353 } 1354 return false; 1355 } 1356 1357 1358 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 1359 const int n = local_interfaces()->length(); 1360 for (int i = 0; i < n; i++) { 1361 Klass* intf1 = local_interfaces()->at(i); 1362 assert(intf1->is_interface(), "just checking type"); 1363 // search for field in current interface 1364 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) { 1365 assert(fd->is_static(), "interface field must be static"); 1366 return intf1; 1367 } 1368 // search for field in direct superinterfaces 1369 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd); 1370 if (intf2 != NULL) return intf2; 1371 } 1372 // otherwise field lookup fails 1373 return NULL; 1374 } 1375 1376 1377 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 1378 // search order according to newest JVM spec (5.4.3.2, p.167). 1379 // 1) search for field in current klass 1380 if (find_local_field(name, sig, fd)) { 1381 return const_cast<InstanceKlass*>(this); 1382 } 1383 // 2) search for field recursively in direct superinterfaces 1384 { Klass* intf = find_interface_field(name, sig, fd); 1385 if (intf != NULL) return intf; 1386 } 1387 // 3) apply field lookup recursively if superclass exists 1388 { Klass* supr = super(); 1389 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd); 1390 } 1391 // 4) otherwise field lookup fails 1392 return NULL; 1393 } 1394 1395 1396 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const { 1397 // search order according to newest JVM spec (5.4.3.2, p.167). 1398 // 1) search for field in current klass 1399 if (find_local_field(name, sig, fd)) { 1400 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this); 1401 } 1402 // 2) search for field recursively in direct superinterfaces 1403 if (is_static) { 1404 Klass* intf = find_interface_field(name, sig, fd); 1405 if (intf != NULL) return intf; 1406 } 1407 // 3) apply field lookup recursively if superclass exists 1408 { Klass* supr = super(); 1409 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd); 1410 } 1411 // 4) otherwise field lookup fails 1412 return NULL; 1413 } 1414 1415 1416 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const { 1417 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 1418 if (fs.offset() == offset) { 1419 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index()); 1420 if (fd->is_static() == is_static) return true; 1421 } 1422 } 1423 return false; 1424 } 1425 1426 1427 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const { 1428 Klass* klass = const_cast<InstanceKlass*>(this); 1429 while (klass != NULL) { 1430 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) { 1431 return true; 1432 } 1433 klass = klass->super(); 1434 } 1435 return false; 1436 } 1437 1438 1439 void InstanceKlass::methods_do(void f(Method* method)) { 1440 // Methods aren't stable until they are loaded. This can be read outside 1441 // a lock through the ClassLoaderData for profiling 1442 if (!is_loaded()) { 1443 return; 1444 } 1445 1446 int len = methods()->length(); 1447 for (int index = 0; index < len; index++) { 1448 Method* m = methods()->at(index); 1449 assert(m->is_method(), "must be method"); 1450 f(m); 1451 } 1452 } 1453 1454 1455 void InstanceKlass::do_local_static_fields(FieldClosure* cl) { 1456 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 1457 if (fs.access_flags().is_static()) { 1458 fieldDescriptor& fd = fs.field_descriptor(); 1459 cl->do_field(&fd); 1460 } 1461 } 1462 } 1463 1464 1465 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) { 1466 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 1467 if (fs.access_flags().is_static()) { 1468 fieldDescriptor& fd = fs.field_descriptor(); 1469 f(&fd, mirror, CHECK); 1470 } 1471 } 1472 } 1473 1474 1475 static int compare_fields_by_offset(int* a, int* b) { 1476 return a[0] - b[0]; 1477 } 1478 1479 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) { 1480 InstanceKlass* super = superklass(); 1481 if (super != NULL) { 1482 super->do_nonstatic_fields(cl); 1483 } 1484 fieldDescriptor fd; 1485 int length = java_fields_count(); 1486 // In DebugInfo nonstatic fields are sorted by offset. 1487 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass); 1488 int j = 0; 1489 for (int i = 0; i < length; i += 1) { 1490 fd.reinitialize(this, i); 1491 if (!fd.is_static()) { 1492 fields_sorted[j + 0] = fd.offset(); 1493 fields_sorted[j + 1] = i; 1494 j += 2; 1495 } 1496 } 1497 if (j > 0) { 1498 length = j; 1499 // _sort_Fn is defined in growableArray.hpp. 1500 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset); 1501 for (int i = 0; i < length; i += 2) { 1502 fd.reinitialize(this, fields_sorted[i + 1]); 1503 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields"); 1504 cl->do_field(&fd); 1505 } 1506 } 1507 FREE_C_HEAP_ARRAY(int, fields_sorted); 1508 } 1509 1510 1511 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 1512 if (array_klasses() != NULL) 1513 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD); 1514 } 1515 1516 void InstanceKlass::array_klasses_do(void f(Klass* k)) { 1517 if (array_klasses() != NULL) 1518 ArrayKlass::cast(array_klasses())->array_klasses_do(f); 1519 } 1520 1521 #ifdef ASSERT 1522 static int linear_search(const Array<Method*>* methods, 1523 const Symbol* name, 1524 const Symbol* signature) { 1525 const int len = methods->length(); 1526 for (int index = 0; index < len; index++) { 1527 const Method* const m = methods->at(index); 1528 assert(m->is_method(), "must be method"); 1529 if (m->signature() == signature && m->name() == name) { 1530 return index; 1531 } 1532 } 1533 return -1; 1534 } 1535 #endif 1536 1537 static int binary_search(const Array<Method*>* methods, const Symbol* name) { 1538 int len = methods->length(); 1539 // methods are sorted, so do binary search 1540 int l = 0; 1541 int h = len - 1; 1542 while (l <= h) { 1543 int mid = (l + h) >> 1; 1544 Method* m = methods->at(mid); 1545 assert(m->is_method(), "must be method"); 1546 int res = m->name()->fast_compare(name); 1547 if (res == 0) { 1548 return mid; 1549 } else if (res < 0) { 1550 l = mid + 1; 1551 } else { 1552 h = mid - 1; 1553 } 1554 } 1555 return -1; 1556 } 1557 1558 // find_method looks up the name/signature in the local methods array 1559 Method* InstanceKlass::find_method(const Symbol* name, 1560 const Symbol* signature) const { 1561 return find_method_impl(name, signature, find_overpass, find_static, find_private); 1562 } 1563 1564 Method* InstanceKlass::find_method_impl(const Symbol* name, 1565 const Symbol* signature, 1566 OverpassLookupMode overpass_mode, 1567 StaticLookupMode static_mode, 1568 PrivateLookupMode private_mode) const { 1569 return InstanceKlass::find_method_impl(methods(), 1570 name, 1571 signature, 1572 overpass_mode, 1573 static_mode, 1574 private_mode); 1575 } 1576 1577 // find_instance_method looks up the name/signature in the local methods array 1578 // and skips over static methods 1579 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods, 1580 const Symbol* name, 1581 const Symbol* signature, 1582 PrivateLookupMode private_mode) { 1583 Method* const meth = InstanceKlass::find_method_impl(methods, 1584 name, 1585 signature, 1586 find_overpass, 1587 skip_static, 1588 private_mode); 1589 assert(((meth == NULL) || !meth->is_static()), 1590 "find_instance_method should have skipped statics"); 1591 return meth; 1592 } 1593 1594 // find_instance_method looks up the name/signature in the local methods array 1595 // and skips over static methods 1596 Method* InstanceKlass::find_instance_method(const Symbol* name, 1597 const Symbol* signature, 1598 PrivateLookupMode private_mode) const { 1599 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode); 1600 } 1601 1602 // Find looks up the name/signature in the local methods array 1603 // and filters on the overpass, static and private flags 1604 // This returns the first one found 1605 // note that the local methods array can have up to one overpass, one static 1606 // and one instance (private or not) with the same name/signature 1607 Method* InstanceKlass::find_local_method(const Symbol* name, 1608 const Symbol* signature, 1609 OverpassLookupMode overpass_mode, 1610 StaticLookupMode static_mode, 1611 PrivateLookupMode private_mode) const { 1612 return InstanceKlass::find_method_impl(methods(), 1613 name, 1614 signature, 1615 overpass_mode, 1616 static_mode, 1617 private_mode); 1618 } 1619 1620 // Find looks up the name/signature in the local methods array 1621 // and filters on the overpass, static and private flags 1622 // This returns the first one found 1623 // note that the local methods array can have up to one overpass, one static 1624 // and one instance (private or not) with the same name/signature 1625 Method* InstanceKlass::find_local_method(const Array<Method*>* methods, 1626 const Symbol* name, 1627 const Symbol* signature, 1628 OverpassLookupMode overpass_mode, 1629 StaticLookupMode static_mode, 1630 PrivateLookupMode private_mode) { 1631 return InstanceKlass::find_method_impl(methods, 1632 name, 1633 signature, 1634 overpass_mode, 1635 static_mode, 1636 private_mode); 1637 } 1638 1639 Method* InstanceKlass::find_method(const Array<Method*>* methods, 1640 const Symbol* name, 1641 const Symbol* signature) { 1642 return InstanceKlass::find_method_impl(methods, 1643 name, 1644 signature, 1645 find_overpass, 1646 find_static, 1647 find_private); 1648 } 1649 1650 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods, 1651 const Symbol* name, 1652 const Symbol* signature, 1653 OverpassLookupMode overpass_mode, 1654 StaticLookupMode static_mode, 1655 PrivateLookupMode private_mode) { 1656 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode); 1657 return hit >= 0 ? methods->at(hit): NULL; 1658 } 1659 1660 // true if method matches signature and conforms to skipping_X conditions. 1661 static bool method_matches(const Method* m, 1662 const Symbol* signature, 1663 bool skipping_overpass, 1664 bool skipping_static, 1665 bool skipping_private) { 1666 return ((m->signature() == signature) && 1667 (!skipping_overpass || !m->is_overpass()) && 1668 (!skipping_static || !m->is_static()) && 1669 (!skipping_private || !m->is_private())); 1670 } 1671 1672 // Used directly for default_methods to find the index into the 1673 // default_vtable_indices, and indirectly by find_method 1674 // find_method_index looks in the local methods array to return the index 1675 // of the matching name/signature. If, overpass methods are being ignored, 1676 // the search continues to find a potential non-overpass match. This capability 1677 // is important during method resolution to prefer a static method, for example, 1678 // over an overpass method. 1679 // There is the possibility in any _method's array to have the same name/signature 1680 // for a static method, an overpass method and a local instance method 1681 // To correctly catch a given method, the search criteria may need 1682 // to explicitly skip the other two. For local instance methods, it 1683 // is often necessary to skip private methods 1684 int InstanceKlass::find_method_index(const Array<Method*>* methods, 1685 const Symbol* name, 1686 const Symbol* signature, 1687 OverpassLookupMode overpass_mode, 1688 StaticLookupMode static_mode, 1689 PrivateLookupMode private_mode) { 1690 const bool skipping_overpass = (overpass_mode == skip_overpass); 1691 const bool skipping_static = (static_mode == skip_static); 1692 const bool skipping_private = (private_mode == skip_private); 1693 const int hit = binary_search(methods, name); 1694 if (hit != -1) { 1695 const Method* const m = methods->at(hit); 1696 1697 // Do linear search to find matching signature. First, quick check 1698 // for common case, ignoring overpasses if requested. 1699 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) { 1700 return hit; 1701 } 1702 1703 // search downwards through overloaded methods 1704 int i; 1705 for (i = hit - 1; i >= 0; --i) { 1706 const Method* const m = methods->at(i); 1707 assert(m->is_method(), "must be method"); 1708 if (m->name() != name) { 1709 break; 1710 } 1711 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) { 1712 return i; 1713 } 1714 } 1715 // search upwards 1716 for (i = hit + 1; i < methods->length(); ++i) { 1717 const Method* const m = methods->at(i); 1718 assert(m->is_method(), "must be method"); 1719 if (m->name() != name) { 1720 break; 1721 } 1722 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) { 1723 return i; 1724 } 1725 } 1726 // not found 1727 #ifdef ASSERT 1728 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 : 1729 linear_search(methods, name, signature); 1730 assert(-1 == index, "binary search should have found entry %d", index); 1731 #endif 1732 } 1733 return -1; 1734 } 1735 1736 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const { 1737 return find_method_by_name(methods(), name, end); 1738 } 1739 1740 int InstanceKlass::find_method_by_name(const Array<Method*>* methods, 1741 const Symbol* name, 1742 int* end_ptr) { 1743 assert(end_ptr != NULL, "just checking"); 1744 int start = binary_search(methods, name); 1745 int end = start + 1; 1746 if (start != -1) { 1747 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start; 1748 while (end < methods->length() && (methods->at(end))->name() == name) ++end; 1749 *end_ptr = end; 1750 return start; 1751 } 1752 return -1; 1753 } 1754 1755 // uncached_lookup_method searches both the local class methods array and all 1756 // superclasses methods arrays, skipping any overpass methods in superclasses, 1757 // and possibly skipping private methods. 1758 Method* InstanceKlass::uncached_lookup_method(const Symbol* name, 1759 const Symbol* signature, 1760 OverpassLookupMode overpass_mode, 1761 PrivateLookupMode private_mode) const { 1762 OverpassLookupMode overpass_local_mode = overpass_mode; 1763 const Klass* klass = this; 1764 while (klass != NULL) { 1765 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name, 1766 signature, 1767 overpass_local_mode, 1768 find_static, 1769 private_mode); 1770 if (method != NULL) { 1771 return method; 1772 } 1773 klass = klass->super(); 1774 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses 1775 } 1776 return NULL; 1777 } 1778 1779 #ifdef ASSERT 1780 // search through class hierarchy and return true if this class or 1781 // one of the superclasses was redefined 1782 bool InstanceKlass::has_redefined_this_or_super() const { 1783 const Klass* klass = this; 1784 while (klass != NULL) { 1785 if (InstanceKlass::cast(klass)->has_been_redefined()) { 1786 return true; 1787 } 1788 klass = klass->super(); 1789 } 1790 return false; 1791 } 1792 #endif 1793 1794 // lookup a method in the default methods list then in all transitive interfaces 1795 // Do NOT return private or static methods 1796 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name, 1797 Symbol* signature) const { 1798 Method* m = NULL; 1799 if (default_methods() != NULL) { 1800 m = find_method(default_methods(), name, signature); 1801 } 1802 // Look up interfaces 1803 if (m == NULL) { 1804 m = lookup_method_in_all_interfaces(name, signature, find_defaults); 1805 } 1806 return m; 1807 } 1808 1809 // lookup a method in all the interfaces that this class implements 1810 // Do NOT return private or static methods, new in JDK8 which are not externally visible 1811 // They should only be found in the initial InterfaceMethodRef 1812 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name, 1813 Symbol* signature, 1814 DefaultsLookupMode defaults_mode) const { 1815 Array<InstanceKlass*>* all_ifs = transitive_interfaces(); 1816 int num_ifs = all_ifs->length(); 1817 InstanceKlass *ik = NULL; 1818 for (int i = 0; i < num_ifs; i++) { 1819 ik = all_ifs->at(i); 1820 Method* m = ik->lookup_method(name, signature); 1821 if (m != NULL && m->is_public() && !m->is_static() && 1822 ((defaults_mode != skip_defaults) || !m->is_default_method())) { 1823 return m; 1824 } 1825 } 1826 return NULL; 1827 } 1828 1829 /* jni_id_for_impl for jfieldIds only */ 1830 JNIid* InstanceKlass::jni_id_for_impl(int offset) { 1831 MutexLocker ml(JfieldIdCreation_lock); 1832 // Retry lookup after we got the lock 1833 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset); 1834 if (probe == NULL) { 1835 // Slow case, allocate new static field identifier 1836 probe = new JNIid(this, offset, jni_ids()); 1837 set_jni_ids(probe); 1838 } 1839 return probe; 1840 } 1841 1842 1843 /* jni_id_for for jfieldIds only */ 1844 JNIid* InstanceKlass::jni_id_for(int offset) { 1845 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset); 1846 if (probe == NULL) { 1847 probe = jni_id_for_impl(offset); 1848 } 1849 return probe; 1850 } 1851 1852 u2 InstanceKlass::enclosing_method_data(int offset) const { 1853 const Array<jushort>* const inner_class_list = inner_classes(); 1854 if (inner_class_list == NULL) { 1855 return 0; 1856 } 1857 const int length = inner_class_list->length(); 1858 if (length % inner_class_next_offset == 0) { 1859 return 0; 1860 } 1861 const int index = length - enclosing_method_attribute_size; 1862 assert(offset < enclosing_method_attribute_size, "invalid offset"); 1863 return inner_class_list->at(index + offset); 1864 } 1865 1866 void InstanceKlass::set_enclosing_method_indices(u2 class_index, 1867 u2 method_index) { 1868 Array<jushort>* inner_class_list = inner_classes(); 1869 assert (inner_class_list != NULL, "_inner_classes list is not set up"); 1870 int length = inner_class_list->length(); 1871 if (length % inner_class_next_offset == enclosing_method_attribute_size) { 1872 int index = length - enclosing_method_attribute_size; 1873 inner_class_list->at_put( 1874 index + enclosing_method_class_index_offset, class_index); 1875 inner_class_list->at_put( 1876 index + enclosing_method_method_index_offset, method_index); 1877 } 1878 } 1879 1880 // Lookup or create a jmethodID. 1881 // This code is called by the VMThread and JavaThreads so the 1882 // locking has to be done very carefully to avoid deadlocks 1883 // and/or other cache consistency problems. 1884 // 1885 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) { 1886 size_t idnum = (size_t)method_h->method_idnum(); 1887 jmethodID* jmeths = methods_jmethod_ids_acquire(); 1888 size_t length = 0; 1889 jmethodID id = NULL; 1890 1891 // We use a double-check locking idiom here because this cache is 1892 // performance sensitive. In the normal system, this cache only 1893 // transitions from NULL to non-NULL which is safe because we use 1894 // release_set_methods_jmethod_ids() to advertise the new cache. 1895 // A partially constructed cache should never be seen by a racing 1896 // thread. We also use release_store() to save a new jmethodID 1897 // in the cache so a partially constructed jmethodID should never be 1898 // seen either. Cache reads of existing jmethodIDs proceed without a 1899 // lock, but cache writes of a new jmethodID requires uniqueness and 1900 // creation of the cache itself requires no leaks so a lock is 1901 // generally acquired in those two cases. 1902 // 1903 // If the RedefineClasses() API has been used, then this cache can 1904 // grow and we'll have transitions from non-NULL to bigger non-NULL. 1905 // Cache creation requires no leaks and we require safety between all 1906 // cache accesses and freeing of the old cache so a lock is generally 1907 // acquired when the RedefineClasses() API has been used. 1908 1909 if (jmeths != NULL) { 1910 // the cache already exists 1911 if (!idnum_can_increment()) { 1912 // the cache can't grow so we can just get the current values 1913 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1914 } else { 1915 // cache can grow so we have to be more careful 1916 if (Threads::number_of_threads() == 0 || 1917 SafepointSynchronize::is_at_safepoint()) { 1918 // we're single threaded or at a safepoint - no locking needed 1919 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1920 } else { 1921 MutexLocker ml(JmethodIdCreation_lock); 1922 get_jmethod_id_length_value(jmeths, idnum, &length, &id); 1923 } 1924 } 1925 } 1926 // implied else: 1927 // we need to allocate a cache so default length and id values are good 1928 1929 if (jmeths == NULL || // no cache yet 1930 length <= idnum || // cache is too short 1931 id == NULL) { // cache doesn't contain entry 1932 1933 // This function can be called by the VMThread so we have to do all 1934 // things that might block on a safepoint before grabbing the lock. 1935 // Otherwise, we can deadlock with the VMThread or have a cache 1936 // consistency issue. These vars keep track of what we might have 1937 // to free after the lock is dropped. 1938 jmethodID to_dealloc_id = NULL; 1939 jmethodID* to_dealloc_jmeths = NULL; 1940 1941 // may not allocate new_jmeths or use it if we allocate it 1942 jmethodID* new_jmeths = NULL; 1943 if (length <= idnum) { 1944 // allocate a new cache that might be used 1945 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count()); 1946 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass); 1947 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID)); 1948 // cache size is stored in element[0], other elements offset by one 1949 new_jmeths[0] = (jmethodID)size; 1950 } 1951 1952 // allocate a new jmethodID that might be used 1953 jmethodID new_id = NULL; 1954 if (method_h->is_old() && !method_h->is_obsolete()) { 1955 // The method passed in is old (but not obsolete), we need to use the current version 1956 Method* current_method = method_with_idnum((int)idnum); 1957 assert(current_method != NULL, "old and but not obsolete, so should exist"); 1958 new_id = Method::make_jmethod_id(class_loader_data(), current_method); 1959 } else { 1960 // It is the current version of the method or an obsolete method, 1961 // use the version passed in 1962 new_id = Method::make_jmethod_id(class_loader_data(), method_h()); 1963 } 1964 1965 if (Threads::number_of_threads() == 0 || 1966 SafepointSynchronize::is_at_safepoint()) { 1967 // we're single threaded or at a safepoint - no locking needed 1968 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths, 1969 &to_dealloc_id, &to_dealloc_jmeths); 1970 } else { 1971 MutexLocker ml(JmethodIdCreation_lock); 1972 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths, 1973 &to_dealloc_id, &to_dealloc_jmeths); 1974 } 1975 1976 // The lock has been dropped so we can free resources. 1977 // Free up either the old cache or the new cache if we allocated one. 1978 if (to_dealloc_jmeths != NULL) { 1979 FreeHeap(to_dealloc_jmeths); 1980 } 1981 // free up the new ID since it wasn't needed 1982 if (to_dealloc_id != NULL) { 1983 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id); 1984 } 1985 } 1986 return id; 1987 } 1988 1989 // Figure out how many jmethodIDs haven't been allocated, and make 1990 // sure space for them is pre-allocated. This makes getting all 1991 // method ids much, much faster with classes with more than 8 1992 // methods, and has a *substantial* effect on performance with jvmti 1993 // code that loads all jmethodIDs for all classes. 1994 void InstanceKlass::ensure_space_for_methodids(int start_offset) { 1995 int new_jmeths = 0; 1996 int length = methods()->length(); 1997 for (int index = start_offset; index < length; index++) { 1998 Method* m = methods()->at(index); 1999 jmethodID id = m->find_jmethod_id_or_null(); 2000 if (id == NULL) { 2001 new_jmeths++; 2002 } 2003 } 2004 if (new_jmeths != 0) { 2005 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths); 2006 } 2007 } 2008 2009 // Common code to fetch the jmethodID from the cache or update the 2010 // cache with the new jmethodID. This function should never do anything 2011 // that causes the caller to go to a safepoint or we can deadlock with 2012 // the VMThread or have cache consistency issues. 2013 // 2014 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update( 2015 size_t idnum, jmethodID new_id, 2016 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p, 2017 jmethodID** to_dealloc_jmeths_p) { 2018 assert(new_id != NULL, "sanity check"); 2019 assert(to_dealloc_id_p != NULL, "sanity check"); 2020 assert(to_dealloc_jmeths_p != NULL, "sanity check"); 2021 assert(Threads::number_of_threads() == 0 || 2022 SafepointSynchronize::is_at_safepoint() || 2023 JmethodIdCreation_lock->owned_by_self(), "sanity check"); 2024 2025 // reacquire the cache - we are locked, single threaded or at a safepoint 2026 jmethodID* jmeths = methods_jmethod_ids_acquire(); 2027 jmethodID id = NULL; 2028 size_t length = 0; 2029 2030 if (jmeths == NULL || // no cache yet 2031 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short 2032 if (jmeths != NULL) { 2033 // copy any existing entries from the old cache 2034 for (size_t index = 0; index < length; index++) { 2035 new_jmeths[index+1] = jmeths[index+1]; 2036 } 2037 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete 2038 } 2039 release_set_methods_jmethod_ids(jmeths = new_jmeths); 2040 } else { 2041 // fetch jmethodID (if any) from the existing cache 2042 id = jmeths[idnum+1]; 2043 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete 2044 } 2045 if (id == NULL) { 2046 // No matching jmethodID in the existing cache or we have a new 2047 // cache or we just grew the cache. This cache write is done here 2048 // by the first thread to win the foot race because a jmethodID 2049 // needs to be unique once it is generally available. 2050 id = new_id; 2051 2052 // The jmethodID cache can be read while unlocked so we have to 2053 // make sure the new jmethodID is complete before installing it 2054 // in the cache. 2055 OrderAccess::release_store(&jmeths[idnum+1], id); 2056 } else { 2057 *to_dealloc_id_p = new_id; // save new id for later delete 2058 } 2059 return id; 2060 } 2061 2062 2063 // Common code to get the jmethodID cache length and the jmethodID 2064 // value at index idnum if there is one. 2065 // 2066 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache, 2067 size_t idnum, size_t *length_p, jmethodID* id_p) { 2068 assert(cache != NULL, "sanity check"); 2069 assert(length_p != NULL, "sanity check"); 2070 assert(id_p != NULL, "sanity check"); 2071 2072 // cache size is stored in element[0], other elements offset by one 2073 *length_p = (size_t)cache[0]; 2074 if (*length_p <= idnum) { // cache is too short 2075 *id_p = NULL; 2076 } else { 2077 *id_p = cache[idnum+1]; // fetch jmethodID (if any) 2078 } 2079 } 2080 2081 2082 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles 2083 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) { 2084 size_t idnum = (size_t)method->method_idnum(); 2085 jmethodID* jmeths = methods_jmethod_ids_acquire(); 2086 size_t length; // length assigned as debugging crumb 2087 jmethodID id = NULL; 2088 if (jmeths != NULL && // If there is a cache 2089 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough, 2090 id = jmeths[idnum+1]; // Look up the id (may be NULL) 2091 } 2092 return id; 2093 } 2094 2095 inline DependencyContext InstanceKlass::dependencies() { 2096 DependencyContext dep_context(&_dep_context); 2097 return dep_context; 2098 } 2099 2100 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) { 2101 return dependencies().mark_dependent_nmethods(changes); 2102 } 2103 2104 void InstanceKlass::add_dependent_nmethod(nmethod* nm) { 2105 dependencies().add_dependent_nmethod(nm); 2106 } 2107 2108 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) { 2109 dependencies().remove_dependent_nmethod(nm, delete_immediately); 2110 } 2111 2112 #ifndef PRODUCT 2113 void InstanceKlass::print_dependent_nmethods(bool verbose) { 2114 dependencies().print_dependent_nmethods(verbose); 2115 } 2116 2117 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) { 2118 return dependencies().is_dependent_nmethod(nm); 2119 } 2120 #endif //PRODUCT 2121 2122 void InstanceKlass::clean_weak_instanceklass_links() { 2123 clean_implementors_list(); 2124 clean_method_data(); 2125 2126 // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here. 2127 DependencyContext dep_context(&_dep_context); 2128 dep_context.expunge_stale_entries(); 2129 } 2130 2131 void InstanceKlass::clean_implementors_list() { 2132 assert(is_loader_alive(), "this klass should be live"); 2133 if (is_interface()) { 2134 if (ClassUnloading) { 2135 Klass* impl = implementor(); 2136 if (impl != NULL) { 2137 if (!impl->is_loader_alive()) { 2138 // remove this guy 2139 Klass** klass = adr_implementor(); 2140 assert(klass != NULL, "null klass"); 2141 if (klass != NULL) { 2142 *klass = NULL; 2143 } 2144 } 2145 } 2146 } 2147 } 2148 } 2149 2150 void InstanceKlass::clean_method_data() { 2151 for (int m = 0; m < methods()->length(); m++) { 2152 MethodData* mdo = methods()->at(m)->method_data(); 2153 if (mdo != NULL) { 2154 mdo->clean_method_data(/*always_clean*/false); 2155 } 2156 } 2157 } 2158 2159 bool InstanceKlass::supers_have_passed_fingerprint_checks() { 2160 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) { 2161 ResourceMark rm; 2162 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name()); 2163 return false; 2164 } 2165 2166 Array<InstanceKlass*>* local_interfaces = this->local_interfaces(); 2167 if (local_interfaces != NULL) { 2168 int length = local_interfaces->length(); 2169 for (int i = 0; i < length; i++) { 2170 InstanceKlass* intf = local_interfaces->at(i); 2171 if (!intf->has_passed_fingerprint_check()) { 2172 ResourceMark rm; 2173 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name()); 2174 return false; 2175 } 2176 } 2177 } 2178 2179 return true; 2180 } 2181 2182 bool InstanceKlass::should_store_fingerprint(bool is_unsafe_anonymous) { 2183 #if INCLUDE_AOT 2184 // We store the fingerprint into the InstanceKlass only in the following 2 cases: 2185 if (CalculateClassFingerprint) { 2186 // (1) We are running AOT to generate a shared library. 2187 return true; 2188 } 2189 if (DumpSharedSpaces) { 2190 // (2) We are running -Xshare:dump to create a shared archive 2191 return true; 2192 } 2193 if (UseAOT && is_unsafe_anonymous) { 2194 // (3) We are using AOT code from a shared library and see an unsafe anonymous class 2195 return true; 2196 } 2197 #endif 2198 2199 // In all other cases we might set the _misc_has_passed_fingerprint_check bit, 2200 // but do not store the 64-bit fingerprint to save space. 2201 return false; 2202 } 2203 2204 bool InstanceKlass::has_stored_fingerprint() const { 2205 #if INCLUDE_AOT 2206 return should_store_fingerprint() || is_shared(); 2207 #else 2208 return false; 2209 #endif 2210 } 2211 2212 uint64_t InstanceKlass::get_stored_fingerprint() const { 2213 address adr = adr_fingerprint(); 2214 if (adr != NULL) { 2215 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned 2216 } 2217 return 0; 2218 } 2219 2220 void InstanceKlass::store_fingerprint(uint64_t fingerprint) { 2221 address adr = adr_fingerprint(); 2222 if (adr != NULL) { 2223 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned 2224 2225 ResourceMark rm; 2226 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name()); 2227 } 2228 } 2229 2230 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) { 2231 Klass::metaspace_pointers_do(it); 2232 2233 if (log_is_enabled(Trace, cds)) { 2234 ResourceMark rm; 2235 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name()); 2236 } 2237 2238 it->push(&_annotations); 2239 it->push((Klass**)&_array_klasses); 2240 it->push(&_constants); 2241 it->push(&_inner_classes); 2242 it->push(&_array_name); 2243 #if INCLUDE_JVMTI 2244 it->push(&_previous_versions); 2245 #endif 2246 it->push(&_methods); 2247 it->push(&_default_methods); 2248 it->push(&_local_interfaces); 2249 it->push(&_transitive_interfaces); 2250 it->push(&_method_ordering); 2251 it->push(&_default_vtable_indices); 2252 it->push(&_fields); 2253 2254 if (itable_length() > 0) { 2255 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable(); 2256 int method_table_offset_in_words = ioe->offset()/wordSize; 2257 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words()) 2258 / itableOffsetEntry::size(); 2259 2260 for (int i = 0; i < nof_interfaces; i ++, ioe ++) { 2261 if (ioe->interface_klass() != NULL) { 2262 it->push(ioe->interface_klass_addr()); 2263 itableMethodEntry* ime = ioe->first_method_entry(this); 2264 int n = klassItable::method_count_for_interface(ioe->interface_klass()); 2265 for (int index = 0; index < n; index ++) { 2266 it->push(ime[index].method_addr()); 2267 } 2268 } 2269 } 2270 } 2271 2272 it->push(&_nest_members); 2273 } 2274 2275 void InstanceKlass::remove_unshareable_info() { 2276 Klass::remove_unshareable_info(); 2277 2278 if (is_in_error_state()) { 2279 // Classes are attempted to link during dumping and may fail, 2280 // but these classes are still in the dictionary and class list in CLD. 2281 // Check in_error state first because in_error is > linked state, so 2282 // is_linked() is true. 2283 // If there's a linking error, there is nothing else to remove. 2284 return; 2285 } 2286 2287 // Reset to the 'allocated' state to prevent any premature accessing to 2288 // a shared class at runtime while the class is still being loaded and 2289 // restored. A class' init_state is set to 'loaded' at runtime when it's 2290 // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()). 2291 _init_state = allocated; 2292 2293 { 2294 MutexLocker ml(Compile_lock); 2295 init_implementor(); 2296 } 2297 2298 constants()->remove_unshareable_info(); 2299 2300 for (int i = 0; i < methods()->length(); i++) { 2301 Method* m = methods()->at(i); 2302 m->remove_unshareable_info(); 2303 } 2304 2305 // do array classes also. 2306 if (array_klasses() != NULL) { 2307 array_klasses()->remove_unshareable_info(); 2308 } 2309 2310 // These are not allocated from metaspace, but they should should all be empty 2311 // during dump time, so we don't need to worry about them in InstanceKlass::iterate(). 2312 guarantee(_source_debug_extension == NULL, "must be"); 2313 guarantee(_dep_context == DependencyContext::EMPTY, "must be"); 2314 guarantee(_osr_nmethods_head == NULL, "must be"); 2315 2316 #if INCLUDE_JVMTI 2317 guarantee(_breakpoints == NULL, "must be"); 2318 guarantee(_previous_versions == NULL, "must be"); 2319 #endif 2320 2321 _init_thread = NULL; 2322 _methods_jmethod_ids = NULL; 2323 _jni_ids = NULL; 2324 _oop_map_cache = NULL; 2325 // clear _nest_host to ensure re-load at runtime 2326 _nest_host = NULL; 2327 } 2328 2329 void InstanceKlass::remove_java_mirror() { 2330 Klass::remove_java_mirror(); 2331 2332 // do array classes also. 2333 if (array_klasses() != NULL) { 2334 array_klasses()->remove_java_mirror(); 2335 } 2336 } 2337 2338 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 2339 // SystemDictionary::add_to_hierarchy() sets the init_state to loaded 2340 // before the InstanceKlass is added to the SystemDictionary. Make 2341 // sure the current state is <loaded. 2342 assert(!is_loaded(), "invalid init state"); 2343 set_package(loader_data, CHECK); 2344 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 2345 2346 Array<Method*>* methods = this->methods(); 2347 int num_methods = methods->length(); 2348 for (int index2 = 0; index2 < num_methods; ++index2) { 2349 methodHandle m(THREAD, methods->at(index2)); 2350 m->restore_unshareable_info(CHECK); 2351 } 2352 if (JvmtiExport::has_redefined_a_class()) { 2353 // Reinitialize vtable because RedefineClasses may have changed some 2354 // entries in this vtable for super classes so the CDS vtable might 2355 // point to old or obsolete entries. RedefineClasses doesn't fix up 2356 // vtables in the shared system dictionary, only the main one. 2357 // It also redefines the itable too so fix that too. 2358 vtable().initialize_vtable(false, CHECK); 2359 itable().initialize_itable(false, CHECK); 2360 } 2361 2362 // restore constant pool resolved references 2363 constants()->restore_unshareable_info(CHECK); 2364 2365 if (array_klasses() != NULL) { 2366 // Array classes have null protection domain. 2367 // --> see ArrayKlass::complete_create_array_klass() 2368 array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK); 2369 } 2370 } 2371 2372 // returns true IFF is_in_error_state() has been changed as a result of this call. 2373 bool InstanceKlass::check_sharing_error_state() { 2374 assert(DumpSharedSpaces, "should only be called during dumping"); 2375 bool old_state = is_in_error_state(); 2376 2377 if (!is_in_error_state()) { 2378 bool bad = false; 2379 for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) { 2380 if (sup->is_in_error_state()) { 2381 bad = true; 2382 break; 2383 } 2384 } 2385 if (!bad) { 2386 Array<InstanceKlass*>* interfaces = transitive_interfaces(); 2387 for (int i = 0; i < interfaces->length(); i++) { 2388 InstanceKlass* iface = interfaces->at(i); 2389 if (iface->is_in_error_state()) { 2390 bad = true; 2391 break; 2392 } 2393 } 2394 } 2395 2396 if (bad) { 2397 set_in_error_state(); 2398 } 2399 } 2400 2401 return (old_state != is_in_error_state()); 2402 } 2403 2404 #if INCLUDE_JVMTI 2405 static void clear_all_breakpoints(Method* m) { 2406 m->clear_all_breakpoints(); 2407 } 2408 #endif 2409 2410 void InstanceKlass::unload_class(InstanceKlass* ik) { 2411 // Release dependencies. 2412 ik->dependencies().remove_all_dependents(); 2413 2414 // notify the debugger 2415 if (JvmtiExport::should_post_class_unload()) { 2416 JvmtiExport::post_class_unload(ik); 2417 } 2418 2419 // notify ClassLoadingService of class unload 2420 ClassLoadingService::notify_class_unloaded(ik); 2421 2422 #if INCLUDE_JFR 2423 assert(ik != NULL, "invariant"); 2424 EventClassUnload event; 2425 event.set_unloadedClass(ik); 2426 event.set_definingClassLoader(ik->class_loader_data()); 2427 event.commit(); 2428 #endif 2429 } 2430 2431 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) { 2432 // Clean up C heap 2433 ik->release_C_heap_structures(); 2434 ik->constants()->release_C_heap_structures(); 2435 } 2436 2437 void InstanceKlass::release_C_heap_structures() { 2438 // Can't release the constant pool here because the constant pool can be 2439 // deallocated separately from the InstanceKlass for default methods and 2440 // redefine classes. 2441 2442 // Deallocate oop map cache 2443 if (_oop_map_cache != NULL) { 2444 delete _oop_map_cache; 2445 _oop_map_cache = NULL; 2446 } 2447 2448 // Deallocate JNI identifiers for jfieldIDs 2449 JNIid::deallocate(jni_ids()); 2450 set_jni_ids(NULL); 2451 2452 jmethodID* jmeths = methods_jmethod_ids_acquire(); 2453 if (jmeths != (jmethodID*)NULL) { 2454 release_set_methods_jmethod_ids(NULL); 2455 FreeHeap(jmeths); 2456 } 2457 2458 assert(_dep_context == DependencyContext::EMPTY, 2459 "dependencies should already be cleaned"); 2460 2461 #if INCLUDE_JVMTI 2462 // Deallocate breakpoint records 2463 if (breakpoints() != 0x0) { 2464 methods_do(clear_all_breakpoints); 2465 assert(breakpoints() == 0x0, "should have cleared breakpoints"); 2466 } 2467 2468 // deallocate the cached class file 2469 if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) { 2470 os::free(_cached_class_file); 2471 _cached_class_file = NULL; 2472 } 2473 #endif 2474 2475 // Decrement symbol reference counts associated with the unloaded class. 2476 if (_name != NULL) _name->decrement_refcount(); 2477 // unreference array name derived from this class name (arrays of an unloaded 2478 // class can't be referenced anymore). 2479 if (_array_name != NULL) _array_name->decrement_refcount(); 2480 if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension); 2481 } 2482 2483 void InstanceKlass::set_source_debug_extension(const char* array, int length) { 2484 if (array == NULL) { 2485 _source_debug_extension = NULL; 2486 } else { 2487 // Adding one to the attribute length in order to store a null terminator 2488 // character could cause an overflow because the attribute length is 2489 // already coded with an u4 in the classfile, but in practice, it's 2490 // unlikely to happen. 2491 assert((length+1) > length, "Overflow checking"); 2492 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass); 2493 for (int i = 0; i < length; i++) { 2494 sde[i] = array[i]; 2495 } 2496 sde[length] = '\0'; 2497 _source_debug_extension = sde; 2498 } 2499 } 2500 2501 const char* InstanceKlass::signature_name() const { 2502 int hash_len = 0; 2503 char hash_buf[40]; 2504 2505 // If this is an unsafe anonymous class, append a hash to make the name unique 2506 if (is_unsafe_anonymous()) { 2507 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0; 2508 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash); 2509 hash_len = (int)strlen(hash_buf); 2510 } 2511 2512 // Get the internal name as a c string 2513 const char* src = (const char*) (name()->as_C_string()); 2514 const int src_length = (int)strlen(src); 2515 2516 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3); 2517 2518 // Add L as type indicator 2519 int dest_index = 0; 2520 dest[dest_index++] = 'L'; 2521 2522 // Add the actual class name 2523 for (int src_index = 0; src_index < src_length; ) { 2524 dest[dest_index++] = src[src_index++]; 2525 } 2526 2527 // If we have a hash, append it 2528 for (int hash_index = 0; hash_index < hash_len; ) { 2529 dest[dest_index++] = hash_buf[hash_index++]; 2530 } 2531 2532 // Add the semicolon and the NULL 2533 dest[dest_index++] = ';'; 2534 dest[dest_index] = '\0'; 2535 return dest; 2536 } 2537 2538 // Used to obtain the package name from a fully qualified class name. 2539 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) { 2540 if (name == NULL) { 2541 return NULL; 2542 } else { 2543 if (name->utf8_length() <= 0) { 2544 return NULL; 2545 } 2546 ResourceMark rm; 2547 const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string()); 2548 if (package_name == NULL) { 2549 return NULL; 2550 } 2551 Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD); 2552 return pkg_name; 2553 } 2554 } 2555 2556 ModuleEntry* InstanceKlass::module() const { 2557 // For an unsafe anonymous class return the host class' module 2558 if (is_unsafe_anonymous()) { 2559 assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class"); 2560 return unsafe_anonymous_host()->module(); 2561 } 2562 2563 // Class is in a named package 2564 if (!in_unnamed_package()) { 2565 return _package_entry->module(); 2566 } 2567 2568 // Class is in an unnamed package, return its loader's unnamed module 2569 return class_loader_data()->unnamed_module(); 2570 } 2571 2572 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) { 2573 2574 // ensure java/ packages only loaded by boot or platform builtin loaders 2575 check_prohibited_package(name(), loader_data, CHECK); 2576 2577 TempNewSymbol pkg_name = package_from_name(name(), CHECK); 2578 2579 if (pkg_name != NULL && loader_data != NULL) { 2580 2581 // Find in class loader's package entry table. 2582 _package_entry = loader_data->packages()->lookup_only(pkg_name); 2583 2584 // If the package name is not found in the loader's package 2585 // entry table, it is an indication that the package has not 2586 // been defined. Consider it defined within the unnamed module. 2587 if (_package_entry == NULL) { 2588 ResourceMark rm; 2589 2590 if (!ModuleEntryTable::javabase_defined()) { 2591 // Before java.base is defined during bootstrapping, define all packages in 2592 // the java.base module. If a non-java.base package is erroneously placed 2593 // in the java.base module it will be caught later when java.base 2594 // is defined by ModuleEntryTable::verify_javabase_packages check. 2595 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL"); 2596 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry()); 2597 } else { 2598 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL"); 2599 _package_entry = loader_data->packages()->lookup(pkg_name, 2600 loader_data->unnamed_module()); 2601 } 2602 2603 // A package should have been successfully created 2604 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s", 2605 name()->as_C_string(), loader_data->loader_name_and_id()); 2606 } 2607 2608 if (log_is_enabled(Debug, module)) { 2609 ResourceMark rm; 2610 ModuleEntry* m = _package_entry->module(); 2611 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s", 2612 external_name(), 2613 pkg_name->as_C_string(), 2614 loader_data->loader_name_and_id(), 2615 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE)); 2616 } 2617 } else { 2618 ResourceMark rm; 2619 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s", 2620 external_name(), 2621 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL", 2622 UNNAMED_MODULE); 2623 } 2624 } 2625 2626 2627 // different versions of is_same_class_package 2628 2629 bool InstanceKlass::is_same_class_package(const Klass* class2) const { 2630 oop classloader1 = this->class_loader(); 2631 PackageEntry* classpkg1 = this->package(); 2632 if (class2->is_objArray_klass()) { 2633 class2 = ObjArrayKlass::cast(class2)->bottom_klass(); 2634 } 2635 2636 oop classloader2; 2637 PackageEntry* classpkg2; 2638 if (class2->is_instance_klass()) { 2639 classloader2 = class2->class_loader(); 2640 classpkg2 = class2->package(); 2641 } else { 2642 assert(class2->is_typeArray_klass(), "should be type array"); 2643 classloader2 = NULL; 2644 classpkg2 = NULL; 2645 } 2646 2647 // Same package is determined by comparing class loader 2648 // and package entries. Both must be the same. This rule 2649 // applies even to classes that are defined in the unnamed 2650 // package, they still must have the same class loader. 2651 if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) { 2652 return true; 2653 } 2654 2655 return false; 2656 } 2657 2658 // return true if this class and other_class are in the same package. Classloader 2659 // and classname information is enough to determine a class's package 2660 bool InstanceKlass::is_same_class_package(oop other_class_loader, 2661 const Symbol* other_class_name) const { 2662 if (!oopDesc::equals(class_loader(), other_class_loader)) { 2663 return false; 2664 } 2665 if (name()->fast_compare(other_class_name) == 0) { 2666 return true; 2667 } 2668 2669 { 2670 ResourceMark rm; 2671 2672 bool bad_class_name = false; 2673 const char* other_pkg = 2674 ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name); 2675 if (bad_class_name) { 2676 return false; 2677 } 2678 // Check that package_from_name() returns NULL, not "", if there is no package. 2679 assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string"); 2680 2681 const Symbol* const this_package_name = 2682 this->package() != NULL ? this->package()->name() : NULL; 2683 2684 if (this_package_name == NULL || other_pkg == NULL) { 2685 // One of the two doesn't have a package. Only return true if the other 2686 // one also doesn't have a package. 2687 return (const char*)this_package_name == other_pkg; 2688 } 2689 2690 // Check if package is identical 2691 return this_package_name->equals(other_pkg); 2692 } 2693 } 2694 2695 // Returns true iff super_method can be overridden by a method in targetclassname 2696 // See JLS 3rd edition 8.4.6.1 2697 // Assumes name-signature match 2698 // "this" is InstanceKlass of super_method which must exist 2699 // note that the InstanceKlass of the method in the targetclassname has not always been created yet 2700 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) { 2701 // Private methods can not be overridden 2702 if (super_method->is_private()) { 2703 return false; 2704 } 2705 // If super method is accessible, then override 2706 if ((super_method->is_protected()) || 2707 (super_method->is_public())) { 2708 return true; 2709 } 2710 // Package-private methods are not inherited outside of package 2711 assert(super_method->is_package_private(), "must be package private"); 2712 return(is_same_class_package(targetclassloader(), targetclassname)); 2713 } 2714 2715 // Only boot and platform class loaders can define classes in "java/" packages. 2716 void InstanceKlass::check_prohibited_package(Symbol* class_name, 2717 ClassLoaderData* loader_data, 2718 TRAPS) { 2719 if (!loader_data->is_boot_class_loader_data() && 2720 !loader_data->is_platform_class_loader_data() && 2721 class_name != NULL) { 2722 ResourceMark rm(THREAD); 2723 char* name = class_name->as_C_string(); 2724 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') { 2725 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK); 2726 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'"); 2727 name = pkg_name->as_C_string(); 2728 const char* class_loader_name = loader_data->loader_name_and_id(); 2729 StringUtils::replace_no_expand(name, "/", "."); 2730 const char* msg_text1 = "Class loader (instance of): "; 2731 const char* msg_text2 = " tried to load prohibited package name: "; 2732 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1; 2733 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len); 2734 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name); 2735 THROW_MSG(vmSymbols::java_lang_SecurityException(), message); 2736 } 2737 } 2738 return; 2739 } 2740 2741 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const { 2742 constantPoolHandle i_cp(THREAD, constants()); 2743 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) { 2744 int ioff = iter.inner_class_info_index(); 2745 if (ioff != 0) { 2746 // Check to see if the name matches the class we're looking for 2747 // before attempting to find the class. 2748 if (i_cp->klass_name_at_matches(this, ioff)) { 2749 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false); 2750 if (this == inner_klass) { 2751 *ooff = iter.outer_class_info_index(); 2752 *noff = iter.inner_name_index(); 2753 return true; 2754 } 2755 } 2756 } 2757 } 2758 return false; 2759 } 2760 2761 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const { 2762 InstanceKlass* outer_klass = NULL; 2763 *inner_is_member = false; 2764 int ooff = 0, noff = 0; 2765 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD); 2766 if (has_inner_classes_attr) { 2767 constantPoolHandle i_cp(THREAD, constants()); 2768 if (ooff != 0) { 2769 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL); 2770 outer_klass = InstanceKlass::cast(ok); 2771 *inner_is_member = true; 2772 } 2773 if (NULL == outer_klass) { 2774 // It may be unsafe anonymous; try for that. 2775 int encl_method_class_idx = enclosing_method_class_index(); 2776 if (encl_method_class_idx != 0) { 2777 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL); 2778 outer_klass = InstanceKlass::cast(ok); 2779 *inner_is_member = false; 2780 } 2781 } 2782 } 2783 2784 // If no inner class attribute found for this class. 2785 if (NULL == outer_klass) return NULL; 2786 2787 // Throws an exception if outer klass has not declared k as an inner klass 2788 // We need evidence that each klass knows about the other, or else 2789 // the system could allow a spoof of an inner class to gain access rights. 2790 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL); 2791 return outer_klass; 2792 } 2793 2794 jint InstanceKlass::compute_modifier_flags(TRAPS) const { 2795 jint access = access_flags().as_int(); 2796 2797 // But check if it happens to be member class. 2798 InnerClassesIterator iter(this); 2799 for (; !iter.done(); iter.next()) { 2800 int ioff = iter.inner_class_info_index(); 2801 // Inner class attribute can be zero, skip it. 2802 // Strange but true: JVM spec. allows null inner class refs. 2803 if (ioff == 0) continue; 2804 2805 // only look at classes that are already loaded 2806 // since we are looking for the flags for our self. 2807 Symbol* inner_name = constants()->klass_name_at(ioff); 2808 if (name() == inner_name) { 2809 // This is really a member class. 2810 access = iter.inner_access_flags(); 2811 break; 2812 } 2813 } 2814 // Remember to strip ACC_SUPER bit 2815 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS; 2816 } 2817 2818 jint InstanceKlass::jvmti_class_status() const { 2819 jint result = 0; 2820 2821 if (is_linked()) { 2822 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED; 2823 } 2824 2825 if (is_initialized()) { 2826 assert(is_linked(), "Class status is not consistent"); 2827 result |= JVMTI_CLASS_STATUS_INITIALIZED; 2828 } 2829 if (is_in_error_state()) { 2830 result |= JVMTI_CLASS_STATUS_ERROR; 2831 } 2832 return result; 2833 } 2834 2835 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) { 2836 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable(); 2837 int method_table_offset_in_words = ioe->offset()/wordSize; 2838 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words()) 2839 / itableOffsetEntry::size(); 2840 2841 for (int cnt = 0 ; ; cnt ++, ioe ++) { 2842 // If the interface isn't implemented by the receiver class, 2843 // the VM should throw IncompatibleClassChangeError. 2844 if (cnt >= nof_interfaces) { 2845 ResourceMark rm(THREAD); 2846 stringStream ss; 2847 bool same_module = (module() == holder->module()); 2848 ss.print("Receiver class %s does not implement " 2849 "the interface %s defining the method to be called " 2850 "(%s%s%s)", 2851 external_name(), holder->external_name(), 2852 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(), 2853 (same_module) ? "" : "; ", 2854 (same_module) ? "" : holder->class_in_module_of_loader()); 2855 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string()); 2856 } 2857 2858 Klass* ik = ioe->interface_klass(); 2859 if (ik == holder) break; 2860 } 2861 2862 itableMethodEntry* ime = ioe->first_method_entry(this); 2863 Method* m = ime[index].method(); 2864 if (m == NULL) { 2865 THROW_NULL(vmSymbols::java_lang_AbstractMethodError()); 2866 } 2867 return m; 2868 } 2869 2870 2871 #if INCLUDE_JVMTI 2872 // update default_methods for redefineclasses for methods that are 2873 // not yet in the vtable due to concurrent subclass define and superinterface 2874 // redefinition 2875 // Note: those in the vtable, should have been updated via adjust_method_entries 2876 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) { 2877 // search the default_methods for uses of either obsolete or EMCP methods 2878 if (default_methods() != NULL) { 2879 for (int index = 0; index < default_methods()->length(); index ++) { 2880 Method* old_method = default_methods()->at(index); 2881 if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) { 2882 continue; // skip uninteresting entries 2883 } 2884 assert(!old_method->is_deleted(), "default methods may not be deleted"); 2885 2886 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum()); 2887 2888 assert(new_method != NULL, "method_with_idnum() should not be NULL"); 2889 assert(old_method != new_method, "sanity check"); 2890 2891 default_methods()->at_put(index, new_method); 2892 if (log_is_enabled(Info, redefine, class, update)) { 2893 ResourceMark rm; 2894 if (!(*trace_name_printed)) { 2895 log_info(redefine, class, update) 2896 ("adjust: klassname=%s default methods from name=%s", 2897 external_name(), old_method->method_holder()->external_name()); 2898 *trace_name_printed = true; 2899 } 2900 log_debug(redefine, class, update, vtables) 2901 ("default method update: %s(%s) ", 2902 new_method->name()->as_C_string(), new_method->signature()->as_C_string()); 2903 } 2904 } 2905 } 2906 } 2907 #endif // INCLUDE_JVMTI 2908 2909 // On-stack replacement stuff 2910 void InstanceKlass::add_osr_nmethod(nmethod* n) { 2911 // only one compilation can be active 2912 { 2913 // This is a short non-blocking critical region, so the no safepoint check is ok. 2914 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag); 2915 assert(n->is_osr_method(), "wrong kind of nmethod"); 2916 n->set_osr_link(osr_nmethods_head()); 2917 set_osr_nmethods_head(n); 2918 // Raise the highest osr level if necessary 2919 if (TieredCompilation) { 2920 Method* m = n->method(); 2921 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level())); 2922 } 2923 } 2924 2925 // Get rid of the osr methods for the same bci that have lower levels. 2926 if (TieredCompilation) { 2927 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) { 2928 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true); 2929 if (inv != NULL && inv->is_in_use()) { 2930 inv->make_not_entrant(); 2931 } 2932 } 2933 } 2934 } 2935 2936 // Remove osr nmethod from the list. Return true if found and removed. 2937 bool InstanceKlass::remove_osr_nmethod(nmethod* n) { 2938 // This is a short non-blocking critical region, so the no safepoint check is ok. 2939 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag); 2940 assert(n->is_osr_method(), "wrong kind of nmethod"); 2941 nmethod* last = NULL; 2942 nmethod* cur = osr_nmethods_head(); 2943 int max_level = CompLevel_none; // Find the max comp level excluding n 2944 Method* m = n->method(); 2945 // Search for match 2946 bool found = false; 2947 while(cur != NULL && cur != n) { 2948 if (TieredCompilation && m == cur->method()) { 2949 // Find max level before n 2950 max_level = MAX2(max_level, cur->comp_level()); 2951 } 2952 last = cur; 2953 cur = cur->osr_link(); 2954 } 2955 nmethod* next = NULL; 2956 if (cur == n) { 2957 found = true; 2958 next = cur->osr_link(); 2959 if (last == NULL) { 2960 // Remove first element 2961 set_osr_nmethods_head(next); 2962 } else { 2963 last->set_osr_link(next); 2964 } 2965 } 2966 n->set_osr_link(NULL); 2967 if (TieredCompilation) { 2968 cur = next; 2969 while (cur != NULL) { 2970 // Find max level after n 2971 if (m == cur->method()) { 2972 max_level = MAX2(max_level, cur->comp_level()); 2973 } 2974 cur = cur->osr_link(); 2975 } 2976 m->set_highest_osr_comp_level(max_level); 2977 } 2978 return found; 2979 } 2980 2981 int InstanceKlass::mark_osr_nmethods(const Method* m) { 2982 // This is a short non-blocking critical region, so the no safepoint check is ok. 2983 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag); 2984 nmethod* osr = osr_nmethods_head(); 2985 int found = 0; 2986 while (osr != NULL) { 2987 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain"); 2988 if (osr->method() == m) { 2989 osr->mark_for_deoptimization(); 2990 found++; 2991 } 2992 osr = osr->osr_link(); 2993 } 2994 return found; 2995 } 2996 2997 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const { 2998 // This is a short non-blocking critical region, so the no safepoint check is ok. 2999 MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag); 3000 nmethod* osr = osr_nmethods_head(); 3001 nmethod* best = NULL; 3002 while (osr != NULL) { 3003 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain"); 3004 // There can be a time when a c1 osr method exists but we are waiting 3005 // for a c2 version. When c2 completes its osr nmethod we will trash 3006 // the c1 version and only be able to find the c2 version. However 3007 // while we overflow in the c1 code at back branches we don't want to 3008 // try and switch to the same code as we are already running 3009 3010 if (osr->method() == m && 3011 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) { 3012 if (match_level) { 3013 if (osr->comp_level() == comp_level) { 3014 // Found a match - return it. 3015 return osr; 3016 } 3017 } else { 3018 if (best == NULL || (osr->comp_level() > best->comp_level())) { 3019 if (osr->comp_level() == CompLevel_highest_tier) { 3020 // Found the best possible - return it. 3021 return osr; 3022 } 3023 best = osr; 3024 } 3025 } 3026 } 3027 osr = osr->osr_link(); 3028 } 3029 if (best != NULL && best->comp_level() >= comp_level && match_level == false) { 3030 return best; 3031 } 3032 return NULL; 3033 } 3034 3035 // ----------------------------------------------------------------------------------------------------- 3036 // Printing 3037 3038 #ifndef PRODUCT 3039 3040 #define BULLET " - " 3041 3042 static const char* state_names[] = { 3043 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error" 3044 }; 3045 3046 static void print_vtable(intptr_t* start, int len, outputStream* st) { 3047 for (int i = 0; i < len; i++) { 3048 intptr_t e = start[i]; 3049 st->print("%d : " INTPTR_FORMAT, i, e); 3050 if (e != 0 && ((Metadata*)e)->is_metaspace_object()) { 3051 st->print(" "); 3052 ((Metadata*)e)->print_value_on(st); 3053 } 3054 st->cr(); 3055 } 3056 } 3057 3058 static void print_vtable(vtableEntry* start, int len, outputStream* st) { 3059 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st); 3060 } 3061 3062 void InstanceKlass::print_on(outputStream* st) const { 3063 assert(is_klass(), "must be klass"); 3064 Klass::print_on(st); 3065 3066 st->print(BULLET"instance size: %d", size_helper()); st->cr(); 3067 st->print(BULLET"klass size: %d", size()); st->cr(); 3068 st->print(BULLET"access: "); access_flags().print_on(st); st->cr(); 3069 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]); 3070 st->print(BULLET"name: "); name()->print_value_on(st); st->cr(); 3071 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr(); 3072 st->print(BULLET"sub: "); 3073 Klass* sub = subklass(); 3074 int n; 3075 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) { 3076 if (n < MaxSubklassPrintSize) { 3077 sub->print_value_on(st); 3078 st->print(" "); 3079 } 3080 } 3081 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize); 3082 st->cr(); 3083 3084 if (is_interface()) { 3085 MutexLocker ml(Compile_lock); 3086 st->print_cr(BULLET"nof implementors: %d", nof_implementors()); 3087 if (nof_implementors() == 1) { 3088 st->print_cr(BULLET"implementor: "); 3089 st->print(" "); 3090 implementor()->print_value_on(st); 3091 st->cr(); 3092 } 3093 } 3094 3095 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr(); 3096 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr(); 3097 if (Verbose || WizardMode) { 3098 Array<Method*>* method_array = methods(); 3099 for (int i = 0; i < method_array->length(); i++) { 3100 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr(); 3101 } 3102 } 3103 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr(); 3104 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr(); 3105 if (Verbose && default_methods() != NULL) { 3106 Array<Method*>* method_array = default_methods(); 3107 for (int i = 0; i < method_array->length(); i++) { 3108 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr(); 3109 } 3110 } 3111 if (default_vtable_indices() != NULL) { 3112 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr(); 3113 } 3114 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr(); 3115 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr(); 3116 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr(); 3117 if (class_loader_data() != NULL) { 3118 st->print(BULLET"class loader data: "); 3119 class_loader_data()->print_value_on(st); 3120 st->cr(); 3121 } 3122 st->print(BULLET"unsafe anonymous host class: "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr(); 3123 if (source_file_name() != NULL) { 3124 st->print(BULLET"source file: "); 3125 source_file_name()->print_value_on(st); 3126 st->cr(); 3127 } 3128 if (source_debug_extension() != NULL) { 3129 st->print(BULLET"source debug extension: "); 3130 st->print("%s", source_debug_extension()); 3131 st->cr(); 3132 } 3133 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr(); 3134 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr(); 3135 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr(); 3136 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr(); 3137 { 3138 bool have_pv = false; 3139 // previous versions are linked together through the InstanceKlass 3140 for (InstanceKlass* pv_node = previous_versions(); 3141 pv_node != NULL; 3142 pv_node = pv_node->previous_versions()) { 3143 if (!have_pv) 3144 st->print(BULLET"previous version: "); 3145 have_pv = true; 3146 pv_node->constants()->print_value_on(st); 3147 } 3148 if (have_pv) st->cr(); 3149 } 3150 3151 if (generic_signature() != NULL) { 3152 st->print(BULLET"generic signature: "); 3153 generic_signature()->print_value_on(st); 3154 st->cr(); 3155 } 3156 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr(); 3157 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr(); 3158 if (java_mirror() != NULL) { 3159 st->print(BULLET"java mirror: "); 3160 java_mirror()->print_value_on(st); 3161 st->cr(); 3162 } else { 3163 st->print_cr(BULLET"java mirror: NULL"); 3164 } 3165 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr(); 3166 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st); 3167 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr(); 3168 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st); 3169 st->print_cr(BULLET"---- static fields (%d words):", static_field_size()); 3170 FieldPrinter print_static_field(st); 3171 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field); 3172 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size()); 3173 FieldPrinter print_nonstatic_field(st); 3174 InstanceKlass* ik = const_cast<InstanceKlass*>(this); 3175 ik->do_nonstatic_fields(&print_nonstatic_field); 3176 3177 st->print(BULLET"non-static oop maps: "); 3178 OopMapBlock* map = start_of_nonstatic_oop_maps(); 3179 OopMapBlock* end_map = map + nonstatic_oop_map_count(); 3180 while (map < end_map) { 3181 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1)); 3182 map++; 3183 } 3184 st->cr(); 3185 } 3186 3187 #endif //PRODUCT 3188 3189 void InstanceKlass::print_value_on(outputStream* st) const { 3190 assert(is_klass(), "must be klass"); 3191 if (Verbose || WizardMode) access_flags().print_on(st); 3192 name()->print_value_on(st); 3193 } 3194 3195 #ifndef PRODUCT 3196 3197 void FieldPrinter::do_field(fieldDescriptor* fd) { 3198 _st->print(BULLET); 3199 if (_obj == NULL) { 3200 fd->print_on(_st); 3201 _st->cr(); 3202 } else { 3203 fd->print_on_for(_st, _obj); 3204 _st->cr(); 3205 } 3206 } 3207 3208 3209 void InstanceKlass::oop_print_on(oop obj, outputStream* st) { 3210 Klass::oop_print_on(obj, st); 3211 3212 if (this == SystemDictionary::String_klass()) { 3213 typeArrayOop value = java_lang_String::value(obj); 3214 juint length = java_lang_String::length(obj); 3215 if (value != NULL && 3216 value->is_typeArray() && 3217 length <= (juint) value->length()) { 3218 st->print(BULLET"string: "); 3219 java_lang_String::print(obj, st); 3220 st->cr(); 3221 if (!WizardMode) return; // that is enough 3222 } 3223 } 3224 3225 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj)); 3226 FieldPrinter print_field(st, obj); 3227 do_nonstatic_fields(&print_field); 3228 3229 if (this == SystemDictionary::Class_klass()) { 3230 st->print(BULLET"signature: "); 3231 java_lang_Class::print_signature(obj, st); 3232 st->cr(); 3233 Klass* mirrored_klass = java_lang_Class::as_Klass(obj); 3234 st->print(BULLET"fake entry for mirror: "); 3235 Metadata::print_value_on_maybe_null(st, mirrored_klass); 3236 st->cr(); 3237 Klass* array_klass = java_lang_Class::array_klass_acquire(obj); 3238 st->print(BULLET"fake entry for array: "); 3239 Metadata::print_value_on_maybe_null(st, array_klass); 3240 st->cr(); 3241 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj)); 3242 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj)); 3243 Klass* real_klass = java_lang_Class::as_Klass(obj); 3244 if (real_klass != NULL && real_klass->is_instance_klass()) { 3245 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field); 3246 } 3247 } else if (this == SystemDictionary::MethodType_klass()) { 3248 st->print(BULLET"signature: "); 3249 java_lang_invoke_MethodType::print_signature(obj, st); 3250 st->cr(); 3251 } 3252 } 3253 3254 bool InstanceKlass::verify_itable_index(int i) { 3255 int method_count = klassItable::method_count_for_interface(this); 3256 assert(i >= 0 && i < method_count, "index out of bounds"); 3257 return true; 3258 } 3259 3260 #endif //PRODUCT 3261 3262 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) { 3263 st->print("a "); 3264 name()->print_value_on(st); 3265 obj->print_address_on(st); 3266 if (this == SystemDictionary::String_klass() 3267 && java_lang_String::value(obj) != NULL) { 3268 ResourceMark rm; 3269 int len = java_lang_String::length(obj); 3270 int plen = (len < 24 ? len : 12); 3271 char* str = java_lang_String::as_utf8_string(obj, 0, plen); 3272 st->print(" = \"%s\"", str); 3273 if (len > plen) 3274 st->print("...[%d]", len); 3275 } else if (this == SystemDictionary::Class_klass()) { 3276 Klass* k = java_lang_Class::as_Klass(obj); 3277 st->print(" = "); 3278 if (k != NULL) { 3279 k->print_value_on(st); 3280 } else { 3281 const char* tname = type2name(java_lang_Class::primitive_type(obj)); 3282 st->print("%s", tname ? tname : "type?"); 3283 } 3284 } else if (this == SystemDictionary::MethodType_klass()) { 3285 st->print(" = "); 3286 java_lang_invoke_MethodType::print_signature(obj, st); 3287 } else if (java_lang_boxing_object::is_instance(obj)) { 3288 st->print(" = "); 3289 java_lang_boxing_object::print(obj, st); 3290 } else if (this == SystemDictionary::LambdaForm_klass()) { 3291 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj); 3292 if (vmentry != NULL) { 3293 st->print(" => "); 3294 vmentry->print_value_on(st); 3295 } 3296 } else if (this == SystemDictionary::MemberName_klass()) { 3297 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj); 3298 if (vmtarget != NULL) { 3299 st->print(" = "); 3300 vmtarget->print_value_on(st); 3301 } else { 3302 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st); 3303 st->print("."); 3304 java_lang_invoke_MemberName::name(obj)->print_value_on(st); 3305 } 3306 } 3307 } 3308 3309 const char* InstanceKlass::internal_name() const { 3310 return external_name(); 3311 } 3312 3313 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data, 3314 const char* module_name, 3315 const ClassFileStream* cfs) const { 3316 if (!log_is_enabled(Info, class, load)) { 3317 return; 3318 } 3319 3320 ResourceMark rm; 3321 LogMessage(class, load) msg; 3322 stringStream info_stream; 3323 3324 // Name and class hierarchy info 3325 info_stream.print("%s", external_name()); 3326 3327 // Source 3328 if (cfs != NULL) { 3329 if (cfs->source() != NULL) { 3330 if (module_name != NULL) { 3331 if (ClassLoader::is_modules_image(cfs->source())) { 3332 info_stream.print(" source: jrt:/%s", module_name); 3333 } else { 3334 info_stream.print(" source: %s", cfs->source()); 3335 } 3336 } else { 3337 info_stream.print(" source: %s", cfs->source()); 3338 } 3339 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) { 3340 Thread* THREAD = Thread::current(); 3341 Klass* caller = 3342 THREAD->is_Java_thread() 3343 ? ((JavaThread*)THREAD)->security_get_caller_class(1) 3344 : NULL; 3345 // caller can be NULL, for example, during a JVMTI VM_Init hook 3346 if (caller != NULL) { 3347 info_stream.print(" source: instance of %s", caller->external_name()); 3348 } else { 3349 // source is unknown 3350 } 3351 } else { 3352 oop class_loader = loader_data->class_loader(); 3353 info_stream.print(" source: %s", class_loader->klass()->external_name()); 3354 } 3355 } else { 3356 info_stream.print(" source: shared objects file"); 3357 } 3358 3359 msg.info("%s", info_stream.as_string()); 3360 3361 if (log_is_enabled(Debug, class, load)) { 3362 stringStream debug_stream; 3363 3364 // Class hierarchy info 3365 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT, 3366 p2i(this), p2i(superklass())); 3367 3368 // Interfaces 3369 if (local_interfaces() != NULL && local_interfaces()->length() > 0) { 3370 debug_stream.print(" interfaces:"); 3371 int length = local_interfaces()->length(); 3372 for (int i = 0; i < length; i++) { 3373 debug_stream.print(" " INTPTR_FORMAT, 3374 p2i(InstanceKlass::cast(local_interfaces()->at(i)))); 3375 } 3376 } 3377 3378 // Class loader 3379 debug_stream.print(" loader: ["); 3380 loader_data->print_value_on(&debug_stream); 3381 debug_stream.print("]"); 3382 3383 // Classfile checksum 3384 if (cfs) { 3385 debug_stream.print(" bytes: %d checksum: %08x", 3386 cfs->length(), 3387 ClassLoader::crc32(0, (const char*)cfs->buffer(), 3388 cfs->length())); 3389 } 3390 3391 msg.debug("%s", debug_stream.as_string()); 3392 } 3393 } 3394 3395 #if INCLUDE_SERVICES 3396 // Size Statistics 3397 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const { 3398 Klass::collect_statistics(sz); 3399 3400 sz->_inst_size = wordSize * size_helper(); 3401 sz->_vtab_bytes = wordSize * vtable_length(); 3402 sz->_itab_bytes = wordSize * itable_length(); 3403 sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size(); 3404 3405 int n = 0; 3406 n += (sz->_methods_array_bytes = sz->count_array(methods())); 3407 n += (sz->_method_ordering_bytes = sz->count_array(method_ordering())); 3408 n += (sz->_local_interfaces_bytes = sz->count_array(local_interfaces())); 3409 n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces())); 3410 n += (sz->_fields_bytes = sz->count_array(fields())); 3411 n += (sz->_inner_classes_bytes = sz->count_array(inner_classes())); 3412 n += (sz->_nest_members_bytes = sz->count_array(nest_members())); 3413 sz->_ro_bytes += n; 3414 3415 const ConstantPool* cp = constants(); 3416 if (cp) { 3417 cp->collect_statistics(sz); 3418 } 3419 3420 const Annotations* anno = annotations(); 3421 if (anno) { 3422 anno->collect_statistics(sz); 3423 } 3424 3425 const Array<Method*>* methods_array = methods(); 3426 if (methods()) { 3427 for (int i = 0; i < methods_array->length(); i++) { 3428 Method* method = methods_array->at(i); 3429 if (method) { 3430 sz->_method_count ++; 3431 method->collect_statistics(sz); 3432 } 3433 } 3434 } 3435 } 3436 #endif // INCLUDE_SERVICES 3437 3438 // Verification 3439 3440 class VerifyFieldClosure: public BasicOopIterateClosure { 3441 protected: 3442 template <class T> void do_oop_work(T* p) { 3443 oop obj = RawAccess<>::oop_load(p); 3444 if (!oopDesc::is_oop_or_null(obj)) { 3445 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj)); 3446 Universe::print_on(tty); 3447 guarantee(false, "boom"); 3448 } 3449 } 3450 public: 3451 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); } 3452 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); } 3453 }; 3454 3455 void InstanceKlass::verify_on(outputStream* st) { 3456 #ifndef PRODUCT 3457 // Avoid redundant verifies, this really should be in product. 3458 if (_verify_count == Universe::verify_count()) return; 3459 _verify_count = Universe::verify_count(); 3460 #endif 3461 3462 // Verify Klass 3463 Klass::verify_on(st); 3464 3465 // Verify that klass is present in ClassLoaderData 3466 guarantee(class_loader_data()->contains_klass(this), 3467 "this class isn't found in class loader data"); 3468 3469 // Verify vtables 3470 if (is_linked()) { 3471 // $$$ This used to be done only for m/s collections. Doing it 3472 // always seemed a valid generalization. (DLD -- 6/00) 3473 vtable().verify(st); 3474 } 3475 3476 // Verify first subklass 3477 if (subklass() != NULL) { 3478 guarantee(subklass()->is_klass(), "should be klass"); 3479 } 3480 3481 // Verify siblings 3482 Klass* super = this->super(); 3483 Klass* sib = next_sibling(); 3484 if (sib != NULL) { 3485 if (sib == this) { 3486 fatal("subclass points to itself " PTR_FORMAT, p2i(sib)); 3487 } 3488 3489 guarantee(sib->is_klass(), "should be klass"); 3490 guarantee(sib->super() == super, "siblings should have same superklass"); 3491 } 3492 3493 // Verify implementor fields requires the Compile_lock, but this is sometimes 3494 // called inside a safepoint, so don't verify. 3495 3496 // Verify local interfaces 3497 if (local_interfaces()) { 3498 Array<InstanceKlass*>* local_interfaces = this->local_interfaces(); 3499 for (int j = 0; j < local_interfaces->length(); j++) { 3500 InstanceKlass* e = local_interfaces->at(j); 3501 guarantee(e->is_klass() && e->is_interface(), "invalid local interface"); 3502 } 3503 } 3504 3505 // Verify transitive interfaces 3506 if (transitive_interfaces() != NULL) { 3507 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces(); 3508 for (int j = 0; j < transitive_interfaces->length(); j++) { 3509 InstanceKlass* e = transitive_interfaces->at(j); 3510 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface"); 3511 } 3512 } 3513 3514 // Verify methods 3515 if (methods() != NULL) { 3516 Array<Method*>* methods = this->methods(); 3517 for (int j = 0; j < methods->length(); j++) { 3518 guarantee(methods->at(j)->is_method(), "non-method in methods array"); 3519 } 3520 for (int j = 0; j < methods->length() - 1; j++) { 3521 Method* m1 = methods->at(j); 3522 Method* m2 = methods->at(j + 1); 3523 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly"); 3524 } 3525 } 3526 3527 // Verify method ordering 3528 if (method_ordering() != NULL) { 3529 Array<int>* method_ordering = this->method_ordering(); 3530 int length = method_ordering->length(); 3531 if (JvmtiExport::can_maintain_original_method_order() || 3532 ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) { 3533 guarantee(length == methods()->length(), "invalid method ordering length"); 3534 jlong sum = 0; 3535 for (int j = 0; j < length; j++) { 3536 int original_index = method_ordering->at(j); 3537 guarantee(original_index >= 0, "invalid method ordering index"); 3538 guarantee(original_index < length, "invalid method ordering index"); 3539 sum += original_index; 3540 } 3541 // Verify sum of indices 0,1,...,length-1 3542 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum"); 3543 } else { 3544 guarantee(length == 0, "invalid method ordering length"); 3545 } 3546 } 3547 3548 // Verify default methods 3549 if (default_methods() != NULL) { 3550 Array<Method*>* methods = this->default_methods(); 3551 for (int j = 0; j < methods->length(); j++) { 3552 guarantee(methods->at(j)->is_method(), "non-method in methods array"); 3553 } 3554 for (int j = 0; j < methods->length() - 1; j++) { 3555 Method* m1 = methods->at(j); 3556 Method* m2 = methods->at(j + 1); 3557 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly"); 3558 } 3559 } 3560 3561 // Verify JNI static field identifiers 3562 if (jni_ids() != NULL) { 3563 jni_ids()->verify(this); 3564 } 3565 3566 // Verify other fields 3567 if (array_klasses() != NULL) { 3568 guarantee(array_klasses()->is_klass(), "should be klass"); 3569 } 3570 if (constants() != NULL) { 3571 guarantee(constants()->is_constantPool(), "should be constant pool"); 3572 } 3573 const Klass* anonymous_host = unsafe_anonymous_host(); 3574 if (anonymous_host != NULL) { 3575 guarantee(anonymous_host->is_klass(), "should be klass"); 3576 } 3577 } 3578 3579 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) { 3580 Klass::oop_verify_on(obj, st); 3581 VerifyFieldClosure blk; 3582 obj->oop_iterate(&blk); 3583 } 3584 3585 3586 // JNIid class for jfieldIDs only 3587 // Note to reviewers: 3588 // These JNI functions are just moved over to column 1 and not changed 3589 // in the compressed oops workspace. 3590 JNIid::JNIid(Klass* holder, int offset, JNIid* next) { 3591 _holder = holder; 3592 _offset = offset; 3593 _next = next; 3594 debug_only(_is_static_field_id = false;) 3595 } 3596 3597 3598 JNIid* JNIid::find(int offset) { 3599 JNIid* current = this; 3600 while (current != NULL) { 3601 if (current->offset() == offset) return current; 3602 current = current->next(); 3603 } 3604 return NULL; 3605 } 3606 3607 void JNIid::deallocate(JNIid* current) { 3608 while (current != NULL) { 3609 JNIid* next = current->next(); 3610 delete current; 3611 current = next; 3612 } 3613 } 3614 3615 3616 void JNIid::verify(Klass* holder) { 3617 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields(); 3618 int end_field_offset; 3619 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize); 3620 3621 JNIid* current = this; 3622 while (current != NULL) { 3623 guarantee(current->holder() == holder, "Invalid klass in JNIid"); 3624 #ifdef ASSERT 3625 int o = current->offset(); 3626 if (current->is_static_field_id()) { 3627 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid"); 3628 } 3629 #endif 3630 current = current->next(); 3631 } 3632 } 3633 3634 #ifdef ASSERT 3635 void InstanceKlass::set_init_state(ClassState state) { 3636 bool good_state = is_shared() ? (_init_state <= state) 3637 : (_init_state < state); 3638 assert(good_state || state == allocated, "illegal state transition"); 3639 _init_state = (u1)state; 3640 } 3641 #endif 3642 3643 #if INCLUDE_JVMTI 3644 3645 // RedefineClasses() support for previous versions 3646 3647 // Globally, there is at least one previous version of a class to walk 3648 // during class unloading, which is saved because old methods in the class 3649 // are still running. Otherwise the previous version list is cleaned up. 3650 bool InstanceKlass::_has_previous_versions = false; 3651 3652 // Returns true if there are previous versions of a class for class 3653 // unloading only. Also resets the flag to false. purge_previous_version 3654 // will set the flag to true if there are any left, i.e., if there's any 3655 // work to do for next time. This is to avoid the expensive code cache 3656 // walk in CLDG::clean_deallocate_lists(). 3657 bool InstanceKlass::has_previous_versions_and_reset() { 3658 bool ret = _has_previous_versions; 3659 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s", 3660 ret ? "true" : "false"); 3661 _has_previous_versions = false; 3662 return ret; 3663 } 3664 3665 // Purge previous versions before adding new previous versions of the class and 3666 // during class unloading. 3667 void InstanceKlass::purge_previous_version_list() { 3668 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint"); 3669 assert(has_been_redefined(), "Should only be called for main class"); 3670 3671 // Quick exit. 3672 if (previous_versions() == NULL) { 3673 return; 3674 } 3675 3676 // This klass has previous versions so see what we can cleanup 3677 // while it is safe to do so. 3678 3679 int deleted_count = 0; // leave debugging breadcrumbs 3680 int live_count = 0; 3681 ClassLoaderData* loader_data = class_loader_data(); 3682 assert(loader_data != NULL, "should never be null"); 3683 3684 ResourceMark rm; 3685 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name()); 3686 3687 // previous versions are linked together through the InstanceKlass 3688 InstanceKlass* pv_node = previous_versions(); 3689 InstanceKlass* last = this; 3690 int version = 0; 3691 3692 // check the previous versions list 3693 for (; pv_node != NULL; ) { 3694 3695 ConstantPool* pvcp = pv_node->constants(); 3696 assert(pvcp != NULL, "cp ref was unexpectedly cleared"); 3697 3698 if (!pvcp->on_stack()) { 3699 // If the constant pool isn't on stack, none of the methods 3700 // are executing. Unlink this previous_version. 3701 // The previous version InstanceKlass is on the ClassLoaderData deallocate list 3702 // so will be deallocated during the next phase of class unloading. 3703 log_trace(redefine, class, iklass, purge) 3704 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node)); 3705 // For debugging purposes. 3706 pv_node->set_is_scratch_class(); 3707 // Unlink from previous version list. 3708 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data"); 3709 InstanceKlass* next = pv_node->previous_versions(); 3710 pv_node->link_previous_versions(NULL); // point next to NULL 3711 last->link_previous_versions(next); 3712 // Add to the deallocate list after unlinking 3713 loader_data->add_to_deallocate_list(pv_node); 3714 pv_node = next; 3715 deleted_count++; 3716 version++; 3717 continue; 3718 } else { 3719 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node)); 3720 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder"); 3721 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack"); 3722 live_count++; 3723 // found a previous version for next time we do class unloading 3724 _has_previous_versions = true; 3725 } 3726 3727 // At least one method is live in this previous version. 3728 // Reset dead EMCP methods not to get breakpoints. 3729 // All methods are deallocated when all of the methods for this class are no 3730 // longer running. 3731 Array<Method*>* method_refs = pv_node->methods(); 3732 if (method_refs != NULL) { 3733 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length()); 3734 for (int j = 0; j < method_refs->length(); j++) { 3735 Method* method = method_refs->at(j); 3736 3737 if (!method->on_stack()) { 3738 // no breakpoints for non-running methods 3739 if (method->is_running_emcp()) { 3740 method->set_running_emcp(false); 3741 } 3742 } else { 3743 assert (method->is_obsolete() || method->is_running_emcp(), 3744 "emcp method cannot run after emcp bit is cleared"); 3745 log_trace(redefine, class, iklass, purge) 3746 ("purge: %s(%s): prev method @%d in version @%d is alive", 3747 method->name()->as_C_string(), method->signature()->as_C_string(), j, version); 3748 } 3749 } 3750 } 3751 // next previous version 3752 last = pv_node; 3753 pv_node = pv_node->previous_versions(); 3754 version++; 3755 } 3756 log_trace(redefine, class, iklass, purge) 3757 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count); 3758 } 3759 3760 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods, 3761 int emcp_method_count) { 3762 int obsolete_method_count = old_methods->length() - emcp_method_count; 3763 3764 if (emcp_method_count != 0 && obsolete_method_count != 0 && 3765 _previous_versions != NULL) { 3766 // We have a mix of obsolete and EMCP methods so we have to 3767 // clear out any matching EMCP method entries the hard way. 3768 int local_count = 0; 3769 for (int i = 0; i < old_methods->length(); i++) { 3770 Method* old_method = old_methods->at(i); 3771 if (old_method->is_obsolete()) { 3772 // only obsolete methods are interesting 3773 Symbol* m_name = old_method->name(); 3774 Symbol* m_signature = old_method->signature(); 3775 3776 // previous versions are linked together through the InstanceKlass 3777 int j = 0; 3778 for (InstanceKlass* prev_version = _previous_versions; 3779 prev_version != NULL; 3780 prev_version = prev_version->previous_versions(), j++) { 3781 3782 Array<Method*>* method_refs = prev_version->methods(); 3783 for (int k = 0; k < method_refs->length(); k++) { 3784 Method* method = method_refs->at(k); 3785 3786 if (!method->is_obsolete() && 3787 method->name() == m_name && 3788 method->signature() == m_signature) { 3789 // The current RedefineClasses() call has made all EMCP 3790 // versions of this method obsolete so mark it as obsolete 3791 log_trace(redefine, class, iklass, add) 3792 ("%s(%s): flush obsolete method @%d in version @%d", 3793 m_name->as_C_string(), m_signature->as_C_string(), k, j); 3794 3795 method->set_is_obsolete(); 3796 break; 3797 } 3798 } 3799 3800 // The previous loop may not find a matching EMCP method, but 3801 // that doesn't mean that we can optimize and not go any 3802 // further back in the PreviousVersion generations. The EMCP 3803 // method for this generation could have already been made obsolete, 3804 // but there still may be an older EMCP method that has not 3805 // been made obsolete. 3806 } 3807 3808 if (++local_count >= obsolete_method_count) { 3809 // no more obsolete methods so bail out now 3810 break; 3811 } 3812 } 3813 } 3814 } 3815 } 3816 3817 // Save the scratch_class as the previous version if any of the methods are running. 3818 // The previous_versions are used to set breakpoints in EMCP methods and they are 3819 // also used to clean MethodData links to redefined methods that are no longer running. 3820 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class, 3821 int emcp_method_count) { 3822 assert(Thread::current()->is_VM_thread(), 3823 "only VMThread can add previous versions"); 3824 3825 ResourceMark rm; 3826 log_trace(redefine, class, iklass, add) 3827 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count); 3828 3829 // Clean out old previous versions for this class 3830 purge_previous_version_list(); 3831 3832 // Mark newly obsolete methods in remaining previous versions. An EMCP method from 3833 // a previous redefinition may be made obsolete by this redefinition. 3834 Array<Method*>* old_methods = scratch_class->methods(); 3835 mark_newly_obsolete_methods(old_methods, emcp_method_count); 3836 3837 // If the constant pool for this previous version of the class 3838 // is not marked as being on the stack, then none of the methods 3839 // in this previous version of the class are on the stack so 3840 // we don't need to add this as a previous version. 3841 ConstantPool* cp_ref = scratch_class->constants(); 3842 if (!cp_ref->on_stack()) { 3843 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running"); 3844 // For debugging purposes. 3845 scratch_class->set_is_scratch_class(); 3846 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class); 3847 return; 3848 } 3849 3850 if (emcp_method_count != 0) { 3851 // At least one method is still running, check for EMCP methods 3852 for (int i = 0; i < old_methods->length(); i++) { 3853 Method* old_method = old_methods->at(i); 3854 if (!old_method->is_obsolete() && old_method->on_stack()) { 3855 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that 3856 // we can add breakpoints for it. 3857 3858 // We set the method->on_stack bit during safepoints for class redefinition 3859 // and use this bit to set the is_running_emcp bit. 3860 // After the safepoint, the on_stack bit is cleared and the running emcp 3861 // method may exit. If so, we would set a breakpoint in a method that 3862 // is never reached, but this won't be noticeable to the programmer. 3863 old_method->set_running_emcp(true); 3864 log_trace(redefine, class, iklass, add) 3865 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method)); 3866 } else if (!old_method->is_obsolete()) { 3867 log_trace(redefine, class, iklass, add) 3868 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method)); 3869 } 3870 } 3871 } 3872 3873 // Add previous version if any methods are still running. 3874 // Set has_previous_version flag for processing during class unloading. 3875 _has_previous_versions = true; 3876 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack."); 3877 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version"); 3878 scratch_class->link_previous_versions(previous_versions()); 3879 link_previous_versions(scratch_class); 3880 } // end add_previous_version() 3881 3882 #endif // INCLUDE_JVMTI 3883 3884 Method* InstanceKlass::method_with_idnum(int idnum) { 3885 Method* m = NULL; 3886 if (idnum < methods()->length()) { 3887 m = methods()->at(idnum); 3888 } 3889 if (m == NULL || m->method_idnum() != idnum) { 3890 for (int index = 0; index < methods()->length(); ++index) { 3891 m = methods()->at(index); 3892 if (m->method_idnum() == idnum) { 3893 return m; 3894 } 3895 } 3896 // None found, return null for the caller to handle. 3897 return NULL; 3898 } 3899 return m; 3900 } 3901 3902 3903 Method* InstanceKlass::method_with_orig_idnum(int idnum) { 3904 if (idnum >= methods()->length()) { 3905 return NULL; 3906 } 3907 Method* m = methods()->at(idnum); 3908 if (m != NULL && m->orig_method_idnum() == idnum) { 3909 return m; 3910 } 3911 // Obsolete method idnum does not match the original idnum 3912 for (int index = 0; index < methods()->length(); ++index) { 3913 m = methods()->at(index); 3914 if (m->orig_method_idnum() == idnum) { 3915 return m; 3916 } 3917 } 3918 // None found, return null for the caller to handle. 3919 return NULL; 3920 } 3921 3922 3923 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) { 3924 InstanceKlass* holder = get_klass_version(version); 3925 if (holder == NULL) { 3926 return NULL; // The version of klass is gone, no method is found 3927 } 3928 Method* method = holder->method_with_orig_idnum(idnum); 3929 return method; 3930 } 3931 3932 #if INCLUDE_JVMTI 3933 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() { 3934 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) { 3935 // Ignore the archived class stream data 3936 return NULL; 3937 } else { 3938 return _cached_class_file; 3939 } 3940 } 3941 3942 jint InstanceKlass::get_cached_class_file_len() { 3943 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file); 3944 } 3945 3946 unsigned char * InstanceKlass::get_cached_class_file_bytes() { 3947 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file); 3948 } 3949 3950 #if INCLUDE_CDS 3951 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() { 3952 if (DumpSharedSpaces) { 3953 return _cached_class_file; 3954 } else { 3955 assert(this->is_shared(), "class should be shared"); 3956 if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) { 3957 return _cached_class_file; 3958 } else { 3959 return NULL; 3960 } 3961 } 3962 } 3963 #endif 3964 #endif