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/javaClasses.hpp"
  32 #include "classfile/moduleEntry.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/systemDictionaryShared.hpp"
  35 #include "classfile/verifier.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "code/dependencyContext.hpp"
  38 #include "compiler/compileBroker.hpp"
  39 #include "gc/shared/collectedHeap.inline.hpp"
  40 #include "gc/shared/specialized_oop_closures.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.hpp"
  70 #include "runtime/handles.inline.hpp"
  71 #include "runtime/javaCalls.hpp"
  72 #include "runtime/mutexLocker.hpp"
  73 #include "runtime/orderAccess.inline.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 
  84 #ifdef DTRACE_ENABLED
  85 
  86 
  87 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  88 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  89 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  90 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  91 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  92 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  93 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  94 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  95 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
  96   {                                                              \
  97     char* data = NULL;                                           \
  98     int len = 0;                                                 \
  99     Symbol* clss_name = name();                                  \
 100     if (clss_name != NULL) {                                     \
 101       data = (char*)clss_name->bytes();                          \
 102       len = clss_name->utf8_length();                            \
 103     }                                                            \
 104     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 105       data, len, (void*)class_loader(), thread_type);            \
 106   }
 107 
 108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 109   {                                                              \
 110     char* data = NULL;                                           \
 111     int len = 0;                                                 \
 112     Symbol* clss_name = name();                                  \
 113     if (clss_name != NULL) {                                     \
 114       data = (char*)clss_name->bytes();                          \
 115       len = clss_name->utf8_length();                            \
 116     }                                                            \
 117     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 118       data, len, (void*)class_loader(), thread_type, wait);      \
 119   }
 120 
 121 #else //  ndef DTRACE_ENABLED
 122 
 123 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 125 
 126 #endif //  ndef DTRACE_ENABLED
 127 
 128 static inline bool is_class_loader(const Symbol* class_name,
 129                                    const ClassFileParser& parser) {
 130   assert(class_name != NULL, "invariant");
 131 
 132   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 133     return true;
 134   }
 135 
 136   if (SystemDictionary::ClassLoader_klass_loaded()) {
 137     const Klass* const super_klass = parser.super_klass();
 138     if (super_klass != NULL) {
 139       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 140         return true;
 141       }
 142     }
 143   }
 144   return false;
 145 }
 146 
 147 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 148   const int size = InstanceKlass::size(parser.vtable_size(),
 149                                        parser.itable_size(),
 150                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 151                                        parser.is_interface(),
 152                                        parser.is_anonymous(),
 153                                        should_store_fingerprint(parser.is_anonymous()));
 154 
 155   const Symbol* const class_name = parser.class_name();
 156   assert(class_name != NULL, "invariant");
 157   ClassLoaderData* loader_data = parser.loader_data();
 158   assert(loader_data != NULL, "invariant");
 159 
 160   InstanceKlass* ik;
 161 
 162   // Allocation
 163   if (REF_NONE == parser.reference_type()) {
 164     if (class_name == vmSymbols::java_lang_Class()) {
 165       // mirror
 166       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 167     }
 168     else if (is_class_loader(class_name, parser)) {
 169       // class loader
 170       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 171     }
 172     else {
 173       // normal
 174       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 175     }
 176   }
 177   else {
 178     // reference
 179     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 180   }
 181 
 182   // Check for pending exception before adding to the loader data and incrementing
 183   // class count.  Can get OOM here.
 184   if (HAS_PENDING_EXCEPTION) {
 185     return NULL;
 186   }
 187 
 188   return ik;
 189 }
 190 
 191 
 192 // copy method ordering from resource area to Metaspace
 193 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 194   if (m != NULL) {
 195     // allocate a new array and copy contents (memcpy?)
 196     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 197     for (int i = 0; i < m->length(); i++) {
 198       _method_ordering->at_put(i, m->at(i));
 199     }
 200   } else {
 201     _method_ordering = Universe::the_empty_int_array();
 202   }
 203 }
 204 
 205 // create a new array of vtable_indices for default methods
 206 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 207   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 208   assert(default_vtable_indices() == NULL, "only create once");
 209   set_default_vtable_indices(vtable_indices);
 210   return vtable_indices;
 211 }
 212 
 213 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
 214   _static_field_size(parser.static_field_size()),
 215   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 216   _itable_len(parser.itable_size()),
 217   _reference_type(parser.reference_type()) {
 218     set_vtable_length(parser.vtable_size());
 219     set_kind(kind);
 220     set_access_flags(parser.access_flags());
 221     set_is_anonymous(parser.is_anonymous());
 222     set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 223                                                     false));
 224 
 225     assert(NULL == _methods, "underlying memory not zeroed?");
 226     assert(is_instance_klass(), "is layout incorrect?");
 227     assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 228 }
 229 
 230 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 231                                        Array<Method*>* methods) {
 232   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 233       !methods->is_shared()) {
 234     for (int i = 0; i < methods->length(); i++) {
 235       Method* method = methods->at(i);
 236       if (method == NULL) continue;  // maybe null if error processing
 237       // Only want to delete methods that are not executing for RedefineClasses.
 238       // The previous version will point to them so they're not totally dangling
 239       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 240       MetadataFactory::free_metadata(loader_data, method);
 241     }
 242     MetadataFactory::free_array<Method*>(loader_data, methods);
 243   }
 244 }
 245 
 246 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 247                                           const Klass* super_klass,
 248                                           Array<Klass*>* local_interfaces,
 249                                           Array<Klass*>* transitive_interfaces) {
 250   // Only deallocate transitive interfaces if not empty, same as super class
 251   // or same as local interfaces.  See code in parseClassFile.
 252   Array<Klass*>* ti = transitive_interfaces;
 253   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 254     // check that the interfaces don't come from super class
 255     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 256                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 257     if (ti != sti && ti != NULL && !ti->is_shared()) {
 258       MetadataFactory::free_array<Klass*>(loader_data, ti);
 259     }
 260   }
 261 
 262   // local interfaces can be empty
 263   if (local_interfaces != Universe::the_empty_klass_array() &&
 264       local_interfaces != NULL && !local_interfaces->is_shared()) {
 265     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 266   }
 267 }
 268 
 269 // This function deallocates the metadata and C heap pointers that the
 270 // InstanceKlass points to.
 271 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 272 
 273   // Orphan the mirror first, CMS thinks it's still live.
 274   if (java_mirror() != NULL) {
 275     java_lang_Class::set_klass(java_mirror(), NULL);
 276   }
 277 
 278   // Also remove mirror from handles
 279   loader_data->remove_handle(_java_mirror);
 280 
 281   // Need to take this class off the class loader data list.
 282   loader_data->remove_class(this);
 283 
 284   // The array_klass for this class is created later, after error handling.
 285   // For class redefinition, we keep the original class so this scratch class
 286   // doesn't have an array class.  Either way, assert that there is nothing
 287   // to deallocate.
 288   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 289 
 290   // Release C heap allocated data that this might point to, which includes
 291   // reference counting symbol names.
 292   release_C_heap_structures();
 293 
 294   deallocate_methods(loader_data, methods());
 295   set_methods(NULL);
 296 
 297   if (method_ordering() != NULL &&
 298       method_ordering() != Universe::the_empty_int_array() &&
 299       !method_ordering()->is_shared()) {
 300     MetadataFactory::free_array<int>(loader_data, method_ordering());
 301   }
 302   set_method_ordering(NULL);
 303 
 304   // default methods can be empty
 305   if (default_methods() != NULL &&
 306       default_methods() != Universe::the_empty_method_array() &&
 307       !default_methods()->is_shared()) {
 308     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 309   }
 310   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 311   set_default_methods(NULL);
 312 
 313   // default methods vtable indices can be empty
 314   if (default_vtable_indices() != NULL &&
 315       !default_vtable_indices()->is_shared()) {
 316     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 317   }
 318   set_default_vtable_indices(NULL);
 319 
 320 
 321   // This array is in Klass, but remove it with the InstanceKlass since
 322   // this place would be the only caller and it can share memory with transitive
 323   // interfaces.
 324   if (secondary_supers() != NULL &&
 325       secondary_supers() != Universe::the_empty_klass_array() &&
 326       secondary_supers() != transitive_interfaces() &&
 327       !secondary_supers()->is_shared()) {
 328     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 329   }
 330   set_secondary_supers(NULL);
 331 
 332   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 333   set_transitive_interfaces(NULL);
 334   set_local_interfaces(NULL);
 335 
 336   if (fields() != NULL && !fields()->is_shared()) {
 337     MetadataFactory::free_array<jushort>(loader_data, fields());
 338   }
 339   set_fields(NULL, 0);
 340 
 341   // If a method from a redefined class is using this constant pool, don't
 342   // delete it, yet.  The new class's previous version will point to this.
 343   if (constants() != NULL) {
 344     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 345     if (!constants()->is_shared()) {
 346       MetadataFactory::free_metadata(loader_data, constants());
 347     }
 348     // Delete any cached resolution errors for the constant pool
 349     SystemDictionary::delete_resolution_error(constants());
 350 
 351     set_constants(NULL);
 352   }
 353 
 354   if (inner_classes() != NULL &&
 355       inner_classes() != Universe::the_empty_short_array() &&
 356       !inner_classes()->is_shared()) {
 357     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 358   }
 359   set_inner_classes(NULL);
 360 
 361   // We should deallocate the Annotations instance if it's not in shared spaces.
 362   if (annotations() != NULL && !annotations()->is_shared()) {
 363     MetadataFactory::free_metadata(loader_data, annotations());
 364   }
 365   set_annotations(NULL);
 366 }
 367 
 368 bool InstanceKlass::should_be_initialized() const {
 369   return !is_initialized();
 370 }
 371 
 372 klassItable InstanceKlass::itable() const {
 373   return klassItable(const_cast<InstanceKlass*>(this));
 374 }
 375 
 376 void InstanceKlass::eager_initialize(Thread *thread) {
 377   if (!EagerInitialization) return;
 378 
 379   if (this->is_not_initialized()) {
 380     // abort if the the class has a class initializer
 381     if (this->class_initializer() != NULL) return;
 382 
 383     // abort if it is java.lang.Object (initialization is handled in genesis)
 384     Klass* super_klass = super();
 385     if (super_klass == NULL) return;
 386 
 387     // abort if the super class should be initialized
 388     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 389 
 390     // call body to expose the this pointer
 391     eager_initialize_impl();
 392   }
 393 }
 394 
 395 // JVMTI spec thinks there are signers and protection domain in the
 396 // instanceKlass.  These accessors pretend these fields are there.
 397 // The hprof specification also thinks these fields are in InstanceKlass.
 398 oop InstanceKlass::protection_domain() const {
 399   // return the protection_domain from the mirror
 400   return java_lang_Class::protection_domain(java_mirror());
 401 }
 402 
 403 // To remove these from requires an incompatible change and CCC request.
 404 objArrayOop InstanceKlass::signers() const {
 405   // return the signers from the mirror
 406   return java_lang_Class::signers(java_mirror());
 407 }
 408 
 409 oop InstanceKlass::init_lock() const {
 410   // return the init lock from the mirror
 411   oop lock = java_lang_Class::init_lock(java_mirror());
 412   // Prevent reordering with any access of initialization state
 413   OrderAccess::loadload();
 414   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 415          "only fully initialized state can have a null lock");
 416   return lock;
 417 }
 418 
 419 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 420 // threads to get this lock will see a null lock and will not lock.
 421 // That's okay because they all check for initialized state after getting
 422 // the lock and return.
 423 void InstanceKlass::fence_and_clear_init_lock() {
 424   // make sure previous stores are all done, notably the init_state.
 425   OrderAccess::storestore();
 426   java_lang_Class::set_init_lock(java_mirror(), NULL);
 427   assert(!is_not_initialized(), "class must be initialized now");
 428 }
 429 
 430 void InstanceKlass::eager_initialize_impl() {
 431   EXCEPTION_MARK;
 432   HandleMark hm(THREAD);
 433   Handle h_init_lock(THREAD, init_lock());
 434   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 435 
 436   // abort if someone beat us to the initialization
 437   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 438 
 439   ClassState old_state = init_state();
 440   link_class_impl(true, THREAD);
 441   if (HAS_PENDING_EXCEPTION) {
 442     CLEAR_PENDING_EXCEPTION;
 443     // Abort if linking the class throws an exception.
 444 
 445     // Use a test to avoid redundantly resetting the state if there's
 446     // no change.  Set_init_state() asserts that state changes make
 447     // progress, whereas here we might just be spinning in place.
 448     if (old_state != _init_state)
 449       set_init_state(old_state);
 450   } else {
 451     // linking successfull, mark class as initialized
 452     set_init_state(fully_initialized);
 453     fence_and_clear_init_lock();
 454     // trace
 455     if (log_is_enabled(Info, class, init)) {
 456       ResourceMark rm(THREAD);
 457       log_info(class, init)("[Initialized %s without side effects]", external_name());
 458     }
 459   }
 460 }
 461 
 462 
 463 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 464 // process. The step comments refers to the procedure described in that section.
 465 // Note: implementation moved to static method to expose the this pointer.
 466 void InstanceKlass::initialize(TRAPS) {
 467   if (this->should_be_initialized()) {
 468     initialize_impl(CHECK);
 469     // Note: at this point the class may be initialized
 470     //       OR it may be in the state of being initialized
 471     //       in case of recursive initialization!
 472   } else {
 473     assert(is_initialized(), "sanity check");
 474   }
 475 }
 476 
 477 
 478 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
 479   // 1) Verify the bytecodes
 480   Verifier::Mode mode =
 481     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 482   return Verifier::verify(this, mode, should_verify_class(), THREAD);
 483 }
 484 
 485 
 486 // Used exclusively by the shared spaces dump mechanism to prevent
 487 // classes mapped into the shared regions in new VMs from appearing linked.
 488 
 489 void InstanceKlass::unlink_class() {
 490   assert(is_linked(), "must be linked");
 491   _init_state = loaded;
 492 }
 493 
 494 void InstanceKlass::link_class(TRAPS) {
 495   assert(is_loaded(), "must be loaded");
 496   if (!is_linked()) {
 497     link_class_impl(true, CHECK);
 498   }
 499 }
 500 
 501 // Called to verify that a class can link during initialization, without
 502 // throwing a VerifyError.
 503 bool InstanceKlass::link_class_or_fail(TRAPS) {
 504   assert(is_loaded(), "must be loaded");
 505   if (!is_linked()) {
 506     link_class_impl(false, CHECK_false);
 507   }
 508   return is_linked();
 509 }
 510 
 511 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
 512   if (DumpSharedSpaces && is_in_error_state()) {
 513     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 514     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 515     // a convenient way to stop repeat attempts to verify the same (bad) class.
 516     //
 517     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 518     // if we are executing Java code. This is not a problem for CDS dumping phase since
 519     // it doesn't execute any Java code.
 520     ResourceMark rm(THREAD);
 521     Exceptions::fthrow(THREAD_AND_LOCATION,
 522                        vmSymbols::java_lang_NoClassDefFoundError(),
 523                        "Class %s, or one of its supertypes, failed class initialization",
 524                        external_name());
 525     return false;
 526   }
 527   // return if already verified
 528   if (is_linked()) {
 529     return true;
 530   }
 531 
 532   // Timing
 533   // timer handles recursion
 534   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 535   JavaThread* jt = (JavaThread*)THREAD;
 536 
 537   // link super class before linking this class
 538   Klass* super_klass = super();
 539   if (super_klass != NULL) {
 540     if (super_klass->is_interface()) {  // check if super class is an interface
 541       ResourceMark rm(THREAD);
 542       Exceptions::fthrow(
 543         THREAD_AND_LOCATION,
 544         vmSymbols::java_lang_IncompatibleClassChangeError(),
 545         "class %s has interface %s as super class",
 546         external_name(),
 547         super_klass->external_name()
 548       );
 549       return false;
 550     }
 551 
 552     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 553     ik_super->link_class_impl(throw_verifyerror, CHECK_false);
 554   }
 555 
 556   // link all interfaces implemented by this class before linking this class
 557   Array<Klass*>* interfaces = local_interfaces();
 558   int num_interfaces = interfaces->length();
 559   for (int index = 0; index < num_interfaces; index++) {
 560     InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
 561     interk->link_class_impl(throw_verifyerror, CHECK_false);
 562   }
 563 
 564   // in case the class is linked in the process of linking its superclasses
 565   if (is_linked()) {
 566     return true;
 567   }
 568 
 569   // trace only the link time for this klass that includes
 570   // the verification time
 571   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 572                              ClassLoader::perf_class_link_selftime(),
 573                              ClassLoader::perf_classes_linked(),
 574                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 575                              jt->get_thread_stat()->perf_timers_addr(),
 576                              PerfClassTraceTime::CLASS_LINK);
 577 
 578   // verification & rewriting
 579   {
 580     HandleMark hm(THREAD);
 581     Handle h_init_lock(THREAD, init_lock());
 582     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 583     // rewritten will have been set if loader constraint error found
 584     // on an earlier link attempt
 585     // don't verify or rewrite if already rewritten
 586     //
 587 
 588     if (!is_linked()) {
 589       if (!is_rewritten()) {
 590         {
 591           bool verify_ok = verify_code(throw_verifyerror, THREAD);
 592           if (!verify_ok) {
 593             return false;
 594           }
 595         }
 596 
 597         // Just in case a side-effect of verify linked this class already
 598         // (which can sometimes happen since the verifier loads classes
 599         // using custom class loaders, which are free to initialize things)
 600         if (is_linked()) {
 601           return true;
 602         }
 603 
 604         // also sets rewritten
 605         rewrite_class(CHECK_false);
 606       } else if (is_shared()) {
 607         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 608       }
 609 
 610       // relocate jsrs and link methods after they are all rewritten
 611       link_methods(CHECK_false);
 612 
 613       // Initialize the vtable and interface table after
 614       // methods have been rewritten since rewrite may
 615       // fabricate new Method*s.
 616       // also does loader constraint checking
 617       //
 618       // initialize_vtable and initialize_itable need to be rerun for
 619       // a shared class if the class is not loaded by the NULL classloader.
 620       ClassLoaderData * loader_data = class_loader_data();
 621       if (!(is_shared() &&
 622             loader_data->is_the_null_class_loader_data())) {
 623         ResourceMark rm(THREAD);
 624         vtable().initialize_vtable(true, CHECK_false);
 625         itable().initialize_itable(true, CHECK_false);
 626       }
 627 #ifdef ASSERT
 628       else {
 629         vtable().verify(tty, true);
 630         // In case itable verification is ever added.
 631         // itable().verify(tty, true);
 632       }
 633 #endif
 634       set_init_state(linked);
 635       if (JvmtiExport::should_post_class_prepare()) {
 636         Thread *thread = THREAD;
 637         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 638         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 639       }
 640     }
 641   }
 642   return true;
 643 }
 644 
 645 
 646 // Rewrite the byte codes of all of the methods of a class.
 647 // The rewriter must be called exactly once. Rewriting must happen after
 648 // verification but before the first method of the class is executed.
 649 void InstanceKlass::rewrite_class(TRAPS) {
 650   assert(is_loaded(), "must be loaded");
 651   if (is_rewritten()) {
 652     assert(is_shared(), "rewriting an unshared class?");
 653     return;
 654   }
 655   Rewriter::rewrite(this, CHECK);
 656   set_rewritten();
 657 }
 658 
 659 // Now relocate and link method entry points after class is rewritten.
 660 // This is outside is_rewritten flag. In case of an exception, it can be
 661 // executed more than once.
 662 void InstanceKlass::link_methods(TRAPS) {
 663   int len = methods()->length();
 664   for (int i = len-1; i >= 0; i--) {
 665     methodHandle m(THREAD, methods()->at(i));
 666 
 667     // Set up method entry points for compiler and interpreter    .
 668     m->link_method(m, CHECK);
 669   }
 670 }
 671 
 672 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 673 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 674   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 675   for (int i = 0; i < local_interfaces()->length(); ++i) {
 676     Klass* iface = local_interfaces()->at(i);
 677     InstanceKlass* ik = InstanceKlass::cast(iface);
 678 
 679     // Initialization is depth first search ie. we start with top of the inheritance tree
 680     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 681     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 682     if (ik->has_nonstatic_concrete_methods()) {
 683       ik->initialize_super_interfaces(CHECK);
 684     }
 685 
 686     // Only initialize() interfaces that "declare" concrete methods.
 687     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 688       ik->initialize(CHECK);
 689     }
 690   }
 691 }
 692 
 693 void InstanceKlass::initialize_impl(TRAPS) {
 694   HandleMark hm(THREAD);
 695 
 696   // Make sure klass is linked (verified) before initialization
 697   // A class could already be verified, since it has been reflected upon.
 698   link_class(CHECK);
 699 
 700   DTRACE_CLASSINIT_PROBE(required, -1);
 701 
 702   bool wait = false;
 703 
 704   // refer to the JVM book page 47 for description of steps
 705   // Step 1
 706   {
 707     Handle h_init_lock(THREAD, init_lock());
 708     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 709 
 710     Thread *self = THREAD; // it's passed the current thread
 711 
 712     // Step 2
 713     // If we were to use wait() instead of waitInterruptibly() then
 714     // we might end up throwing IE from link/symbol resolution sites
 715     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 716     while(is_being_initialized() && !is_reentrant_initialization(self)) {
 717         wait = true;
 718       ol.waitUninterruptibly(CHECK);
 719     }
 720 
 721     // Step 3
 722     if (is_being_initialized() && is_reentrant_initialization(self)) {
 723       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 724       return;
 725     }
 726 
 727     // Step 4
 728     if (is_initialized()) {
 729       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 730       return;
 731     }
 732 
 733     // Step 5
 734     if (is_in_error_state()) {
 735       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 736       ResourceMark rm(THREAD);
 737       const char* desc = "Could not initialize class ";
 738       const char* className = external_name();
 739       size_t msglen = strlen(desc) + strlen(className) + 1;
 740       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 741       if (NULL == message) {
 742         // Out of memory: can't create detailed error message
 743           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 744       } else {
 745         jio_snprintf(message, msglen, "%s%s", desc, className);
 746           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 747       }
 748     }
 749 
 750     // Step 6
 751     set_init_state(being_initialized);
 752     set_init_thread(self);
 753   }
 754 
 755   // Step 7
 756   // Next, if C is a class rather than an interface, initialize it's super class and super
 757   // interfaces.
 758   if (!is_interface()) {
 759     Klass* super_klass = super();
 760     if (super_klass != NULL && super_klass->should_be_initialized()) {
 761       super_klass->initialize(THREAD);
 762     }
 763     // If C implements any interface that declares a non-static, concrete method,
 764     // the initialization of C triggers initialization of its super interfaces.
 765     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
 766     // having a superinterface that declares, non-static, concrete methods
 767     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
 768       initialize_super_interfaces(THREAD);
 769     }
 770 
 771     // If any exceptions, complete abruptly, throwing the same exception as above.
 772     if (HAS_PENDING_EXCEPTION) {
 773       Handle e(THREAD, PENDING_EXCEPTION);
 774       CLEAR_PENDING_EXCEPTION;
 775       {
 776         EXCEPTION_MARK;
 777         // Locks object, set state, and notify all waiting threads
 778         set_initialization_state_and_notify(initialization_error, THREAD);
 779         CLEAR_PENDING_EXCEPTION;
 780       }
 781       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
 782       THROW_OOP(e());
 783     }
 784   }
 785 
 786 
 787   // Look for aot compiled methods for this klass, including class initializer.
 788   AOTLoader::load_for_klass(this, THREAD);
 789 
 790   // Step 8
 791   {
 792     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 793     JavaThread* jt = (JavaThread*)THREAD;
 794     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
 795     // Timer includes any side effects of class initialization (resolution,
 796     // etc), but not recursive entry into call_class_initializer().
 797     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 798                              ClassLoader::perf_class_init_selftime(),
 799                              ClassLoader::perf_classes_inited(),
 800                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 801                              jt->get_thread_stat()->perf_timers_addr(),
 802                              PerfClassTraceTime::CLASS_CLINIT);
 803     call_class_initializer(THREAD);
 804   }
 805 
 806   // Step 9
 807   if (!HAS_PENDING_EXCEPTION) {
 808     set_initialization_state_and_notify(fully_initialized, CHECK);
 809     {
 810       debug_only(vtable().verify(tty, true);)
 811     }
 812   }
 813   else {
 814     // Step 10 and 11
 815     Handle e(THREAD, PENDING_EXCEPTION);
 816     CLEAR_PENDING_EXCEPTION;
 817     // JVMTI has already reported the pending exception
 818     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 819     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 820     {
 821       EXCEPTION_MARK;
 822       set_initialization_state_and_notify(initialization_error, THREAD);
 823       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 824       // JVMTI has already reported the pending exception
 825       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 826       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 827     }
 828     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
 829     if (e->is_a(SystemDictionary::Error_klass())) {
 830       THROW_OOP(e());
 831     } else {
 832       JavaCallArguments args(e);
 833       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 834                 vmSymbols::throwable_void_signature(),
 835                 &args);
 836     }
 837   }
 838   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
 839 }
 840 
 841 
 842 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 843   Handle h_init_lock(THREAD, init_lock());
 844   if (h_init_lock() != NULL) {
 845     ObjectLocker ol(h_init_lock, THREAD);
 846     set_init_state(state);
 847     fence_and_clear_init_lock();
 848     ol.notify_all(CHECK);
 849   } else {
 850     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
 851     set_init_state(state);
 852   }
 853 }
 854 
 855 // The embedded _implementor field can only record one implementor.
 856 // When there are more than one implementors, the _implementor field
 857 // is set to the interface Klass* itself. Following are the possible
 858 // values for the _implementor field:
 859 //   NULL                  - no implementor
 860 //   implementor Klass*    - one implementor
 861 //   self                  - more than one implementor
 862 //
 863 // The _implementor field only exists for interfaces.
 864 void InstanceKlass::add_implementor(Klass* k) {
 865   assert(Compile_lock->owned_by_self(), "");
 866   assert(is_interface(), "not interface");
 867   // Filter out my subinterfaces.
 868   // (Note: Interfaces are never on the subklass list.)
 869   if (InstanceKlass::cast(k)->is_interface()) return;
 870 
 871   // Filter out subclasses whose supers already implement me.
 872   // (Note: CHA must walk subclasses of direct implementors
 873   // in order to locate indirect implementors.)
 874   Klass* sk = k->super();
 875   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 876     // We only need to check one immediate superclass, since the
 877     // implements_interface query looks at transitive_interfaces.
 878     // Any supers of the super have the same (or fewer) transitive_interfaces.
 879     return;
 880 
 881   Klass* ik = implementor();
 882   if (ik == NULL) {
 883     set_implementor(k);
 884   } else if (ik != this) {
 885     // There is already an implementor. Use itself as an indicator of
 886     // more than one implementors.
 887     set_implementor(this);
 888   }
 889 
 890   // The implementor also implements the transitive_interfaces
 891   for (int index = 0; index < local_interfaces()->length(); index++) {
 892     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 893   }
 894 }
 895 
 896 void InstanceKlass::init_implementor() {
 897   if (is_interface()) {
 898     set_implementor(NULL);
 899   }
 900 }
 901 
 902 
 903 void InstanceKlass::process_interfaces(Thread *thread) {
 904   // link this class into the implementors list of every interface it implements
 905   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 906     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 907     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 908     assert(interf->is_interface(), "expected interface");
 909     interf->add_implementor(this);
 910   }
 911 }
 912 
 913 bool InstanceKlass::can_be_primary_super_slow() const {
 914   if (is_interface())
 915     return false;
 916   else
 917     return Klass::can_be_primary_super_slow();
 918 }
 919 
 920 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
 921   // The secondaries are the implemented interfaces.
 922   Array<Klass*>* interfaces = transitive_interfaces();
 923   int num_secondaries = num_extra_slots + interfaces->length();
 924   if (num_secondaries == 0) {
 925     // Must share this for correct bootstrapping!
 926     set_secondary_supers(Universe::the_empty_klass_array());
 927     return NULL;
 928   } else if (num_extra_slots == 0) {
 929     // The secondary super list is exactly the same as the transitive interfaces.
 930     // Redefine classes has to be careful not to delete this!
 931     set_secondary_supers(interfaces);
 932     return NULL;
 933   } else {
 934     // Copy transitive interfaces to a temporary growable array to be constructed
 935     // into the secondary super list with extra slots.
 936     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 937     for (int i = 0; i < interfaces->length(); i++) {
 938       secondaries->push(interfaces->at(i));
 939     }
 940     return secondaries;
 941   }
 942 }
 943 
 944 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 945   if (k->is_interface()) {
 946     return implements_interface(k);
 947   } else {
 948     return Klass::compute_is_subtype_of(k);
 949   }
 950 }
 951 
 952 bool InstanceKlass::implements_interface(Klass* k) const {
 953   if (this == k) return true;
 954   assert(k->is_interface(), "should be an interface class");
 955   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 956     if (transitive_interfaces()->at(i) == k) {
 957       return true;
 958     }
 959   }
 960   return false;
 961 }
 962 
 963 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
 964   // Verify direct super interface
 965   if (this == k) return true;
 966   assert(k->is_interface(), "should be an interface class");
 967   for (int i = 0; i < local_interfaces()->length(); i++) {
 968     if (local_interfaces()->at(i) == k) {
 969       return true;
 970     }
 971   }
 972   return false;
 973 }
 974 
 975 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
 976   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
 977   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 978     report_java_out_of_memory("Requested array size exceeds VM limit");
 979     JvmtiExport::post_array_size_exhausted();
 980     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 981   }
 982   int size = objArrayOopDesc::object_size(length);
 983   Klass* ak = array_klass(n, CHECK_NULL);
 984   objArrayOop o =
 985     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
 986   return o;
 987 }
 988 
 989 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
 990   if (TraceFinalizerRegistration) {
 991     tty->print("Registered ");
 992     i->print_value_on(tty);
 993     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
 994   }
 995   instanceHandle h_i(THREAD, i);
 996   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
 997   JavaValue result(T_VOID);
 998   JavaCallArguments args(h_i);
 999   methodHandle mh (THREAD, Universe::finalizer_register_method());
1000   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1001   return h_i();
1002 }
1003 
1004 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1005   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1006   int size = size_helper();  // Query before forming handle.
1007 
1008   instanceOop i;
1009 
1010   i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1011   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1012     i = register_finalizer(i, CHECK_NULL);
1013   }
1014   return i;
1015 }
1016 
1017 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1018   return instanceHandle(THREAD, allocate_instance(THREAD));
1019 }
1020 
1021 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1022   if (is_interface() || is_abstract()) {
1023     ResourceMark rm(THREAD);
1024     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1025               : vmSymbols::java_lang_InstantiationException(), external_name());
1026   }
1027   if (this == SystemDictionary::Class_klass()) {
1028     ResourceMark rm(THREAD);
1029     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1030               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1031   }
1032 }
1033 
1034 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1035   // Need load-acquire for lock-free read
1036   if (array_klasses_acquire() == NULL) {
1037     if (or_null) return NULL;
1038 
1039     ResourceMark rm;
1040     JavaThread *jt = (JavaThread *)THREAD;
1041     {
1042       // Atomic creation of array_klasses
1043       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1044       MutexLocker ma(MultiArray_lock, THREAD);
1045 
1046       // Check if update has already taken place
1047       if (array_klasses() == NULL) {
1048         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1049         // use 'release' to pair with lock-free load
1050         release_set_array_klasses(k);
1051       }
1052     }
1053   }
1054   // _this will always be set at this point
1055   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1056   if (or_null) {
1057     return oak->array_klass_or_null(n);
1058   }
1059   return oak->array_klass(n, THREAD);
1060 }
1061 
1062 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1063   return array_klass_impl(or_null, 1, THREAD);
1064 }
1065 
1066 static int call_class_initializer_counter = 0;   // for debugging
1067 
1068 Method* InstanceKlass::class_initializer() const {
1069   Method* clinit = find_method(
1070       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1071   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1072     return clinit;
1073   }
1074   return NULL;
1075 }
1076 
1077 void InstanceKlass::call_class_initializer(TRAPS) {
1078   if (ReplayCompiles &&
1079       (ReplaySuppressInitializers == 1 ||
1080        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1081     // Hide the existence of the initializer for the purpose of replaying the compile
1082     return;
1083   }
1084 
1085   methodHandle h_method(THREAD, class_initializer());
1086   assert(!is_initialized(), "we cannot initialize twice");
1087   LogTarget(Info, class, init) lt;
1088   if (lt.is_enabled()) {
1089     ResourceMark rm;
1090     LogStream ls(lt);
1091     ls.print("%d Initializing ", call_class_initializer_counter++);
1092     name()->print_value_on(&ls);
1093     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1094   }
1095   if (h_method() != NULL) {
1096     JavaCallArguments args; // No arguments
1097     JavaValue result(T_VOID);
1098     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1099   }
1100 }
1101 
1102 
1103 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1104   InterpreterOopMap* entry_for) {
1105   // Lazily create the _oop_map_cache at first request
1106   // Lock-free access requires load_acquire.
1107   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1108   if (oop_map_cache == NULL) {
1109     MutexLocker x(OopMapCacheAlloc_lock);
1110     // Check if _oop_map_cache was allocated while we were waiting for this lock
1111     if ((oop_map_cache = _oop_map_cache) == NULL) {
1112       oop_map_cache = new OopMapCache();
1113       // Ensure _oop_map_cache is stable, since it is examined without a lock
1114       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1115     }
1116   }
1117   // _oop_map_cache is constant after init; lookup below does its own locking.
1118   oop_map_cache->lookup(method, bci, entry_for);
1119 }
1120 
1121 
1122 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1123   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1124     Symbol* f_name = fs.name();
1125     Symbol* f_sig  = fs.signature();
1126     if (f_name == name && f_sig == sig) {
1127       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1128       return true;
1129     }
1130   }
1131   return false;
1132 }
1133 
1134 
1135 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1136   const int n = local_interfaces()->length();
1137   for (int i = 0; i < n; i++) {
1138     Klass* intf1 = local_interfaces()->at(i);
1139     assert(intf1->is_interface(), "just checking type");
1140     // search for field in current interface
1141     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1142       assert(fd->is_static(), "interface field must be static");
1143       return intf1;
1144     }
1145     // search for field in direct superinterfaces
1146     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1147     if (intf2 != NULL) return intf2;
1148   }
1149   // otherwise field lookup fails
1150   return NULL;
1151 }
1152 
1153 
1154 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1155   // search order according to newest JVM spec (5.4.3.2, p.167).
1156   // 1) search for field in current klass
1157   if (find_local_field(name, sig, fd)) {
1158     return const_cast<InstanceKlass*>(this);
1159   }
1160   // 2) search for field recursively in direct superinterfaces
1161   { Klass* intf = find_interface_field(name, sig, fd);
1162     if (intf != NULL) return intf;
1163   }
1164   // 3) apply field lookup recursively if superclass exists
1165   { Klass* supr = super();
1166     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1167   }
1168   // 4) otherwise field lookup fails
1169   return NULL;
1170 }
1171 
1172 
1173 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1174   // search order according to newest JVM spec (5.4.3.2, p.167).
1175   // 1) search for field in current klass
1176   if (find_local_field(name, sig, fd)) {
1177     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1178   }
1179   // 2) search for field recursively in direct superinterfaces
1180   if (is_static) {
1181     Klass* intf = find_interface_field(name, sig, fd);
1182     if (intf != NULL) return intf;
1183   }
1184   // 3) apply field lookup recursively if superclass exists
1185   { Klass* supr = super();
1186     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1187   }
1188   // 4) otherwise field lookup fails
1189   return NULL;
1190 }
1191 
1192 
1193 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1194   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1195     if (fs.offset() == offset) {
1196       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1197       if (fd->is_static() == is_static) return true;
1198     }
1199   }
1200   return false;
1201 }
1202 
1203 
1204 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1205   Klass* klass = const_cast<InstanceKlass*>(this);
1206   while (klass != NULL) {
1207     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1208       return true;
1209     }
1210     klass = klass->super();
1211   }
1212   return false;
1213 }
1214 
1215 
1216 void InstanceKlass::methods_do(void f(Method* method)) {
1217   // Methods aren't stable until they are loaded.  This can be read outside
1218   // a lock through the ClassLoaderData for profiling
1219   if (!is_loaded()) {
1220     return;
1221   }
1222 
1223   int len = methods()->length();
1224   for (int index = 0; index < len; index++) {
1225     Method* m = methods()->at(index);
1226     assert(m->is_method(), "must be method");
1227     f(m);
1228   }
1229 }
1230 
1231 
1232 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1233   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1234     if (fs.access_flags().is_static()) {
1235       fieldDescriptor& fd = fs.field_descriptor();
1236       cl->do_field(&fd);
1237     }
1238   }
1239 }
1240 
1241 
1242 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1243   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1244     if (fs.access_flags().is_static()) {
1245       fieldDescriptor& fd = fs.field_descriptor();
1246       f(&fd, mirror, CHECK);
1247     }
1248   }
1249 }
1250 
1251 
1252 static int compare_fields_by_offset(int* a, int* b) {
1253   return a[0] - b[0];
1254 }
1255 
1256 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1257   InstanceKlass* super = superklass();
1258   if (super != NULL) {
1259     super->do_nonstatic_fields(cl);
1260   }
1261   fieldDescriptor fd;
1262   int length = java_fields_count();
1263   // In DebugInfo nonstatic fields are sorted by offset.
1264   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1265   int j = 0;
1266   for (int i = 0; i < length; i += 1) {
1267     fd.reinitialize(this, i);
1268     if (!fd.is_static()) {
1269       fields_sorted[j + 0] = fd.offset();
1270       fields_sorted[j + 1] = i;
1271       j += 2;
1272     }
1273   }
1274   if (j > 0) {
1275     length = j;
1276     // _sort_Fn is defined in growableArray.hpp.
1277     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1278     for (int i = 0; i < length; i += 2) {
1279       fd.reinitialize(this, fields_sorted[i + 1]);
1280       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1281       cl->do_field(&fd);
1282     }
1283   }
1284   FREE_C_HEAP_ARRAY(int, fields_sorted);
1285 }
1286 
1287 
1288 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1289   if (array_klasses() != NULL)
1290     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1291 }
1292 
1293 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1294   if (array_klasses() != NULL)
1295     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1296 }
1297 
1298 #ifdef ASSERT
1299 static int linear_search(const Array<Method*>* methods,
1300                          const Symbol* name,
1301                          const Symbol* signature) {
1302   const int len = methods->length();
1303   for (int index = 0; index < len; index++) {
1304     const Method* const m = methods->at(index);
1305     assert(m->is_method(), "must be method");
1306     if (m->signature() == signature && m->name() == name) {
1307        return index;
1308     }
1309   }
1310   return -1;
1311 }
1312 #endif
1313 
1314 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1315   int len = methods->length();
1316   // methods are sorted, so do binary search
1317   int l = 0;
1318   int h = len - 1;
1319   while (l <= h) {
1320     int mid = (l + h) >> 1;
1321     Method* m = methods->at(mid);
1322     assert(m->is_method(), "must be method");
1323     int res = m->name()->fast_compare(name);
1324     if (res == 0) {
1325       return mid;
1326     } else if (res < 0) {
1327       l = mid + 1;
1328     } else {
1329       h = mid - 1;
1330     }
1331   }
1332   return -1;
1333 }
1334 
1335 // find_method looks up the name/signature in the local methods array
1336 Method* InstanceKlass::find_method(const Symbol* name,
1337                                    const Symbol* signature) const {
1338   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1339 }
1340 
1341 Method* InstanceKlass::find_method_impl(const Symbol* name,
1342                                         const Symbol* signature,
1343                                         OverpassLookupMode overpass_mode,
1344                                         StaticLookupMode static_mode,
1345                                         PrivateLookupMode private_mode) const {
1346   return InstanceKlass::find_method_impl(methods(),
1347                                          name,
1348                                          signature,
1349                                          overpass_mode,
1350                                          static_mode,
1351                                          private_mode);
1352 }
1353 
1354 // find_instance_method looks up the name/signature in the local methods array
1355 // and skips over static methods
1356 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1357                                             const Symbol* name,
1358                                             const Symbol* signature) {
1359   Method* const meth = InstanceKlass::find_method_impl(methods,
1360                                                  name,
1361                                                  signature,
1362                                                  find_overpass,
1363                                                  skip_static,
1364                                                  find_private);
1365   assert(((meth == NULL) || !meth->is_static()),
1366     "find_instance_method should have skipped statics");
1367   return meth;
1368 }
1369 
1370 // find_instance_method looks up the name/signature in the local methods array
1371 // and skips over static methods
1372 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1373   return InstanceKlass::find_instance_method(methods(), name, signature);
1374 }
1375 
1376 // Find looks up the name/signature in the local methods array
1377 // and filters on the overpass, static and private flags
1378 // This returns the first one found
1379 // note that the local methods array can have up to one overpass, one static
1380 // and one instance (private or not) with the same name/signature
1381 Method* InstanceKlass::find_local_method(const Symbol* name,
1382                                          const Symbol* signature,
1383                                          OverpassLookupMode overpass_mode,
1384                                          StaticLookupMode static_mode,
1385                                          PrivateLookupMode private_mode) const {
1386   return InstanceKlass::find_method_impl(methods(),
1387                                          name,
1388                                          signature,
1389                                          overpass_mode,
1390                                          static_mode,
1391                                          private_mode);
1392 }
1393 
1394 // Find looks up the name/signature in the local methods array
1395 // and filters on the overpass, static and private flags
1396 // This returns the first one found
1397 // note that the local methods array can have up to one overpass, one static
1398 // and one instance (private or not) with the same name/signature
1399 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1400                                          const Symbol* name,
1401                                          const Symbol* signature,
1402                                          OverpassLookupMode overpass_mode,
1403                                          StaticLookupMode static_mode,
1404                                          PrivateLookupMode private_mode) {
1405   return InstanceKlass::find_method_impl(methods,
1406                                          name,
1407                                          signature,
1408                                          overpass_mode,
1409                                          static_mode,
1410                                          private_mode);
1411 }
1412 
1413 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1414                                    const Symbol* name,
1415                                    const Symbol* signature) {
1416   return InstanceKlass::find_method_impl(methods,
1417                                          name,
1418                                          signature,
1419                                          find_overpass,
1420                                          find_static,
1421                                          find_private);
1422 }
1423 
1424 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1425                                         const Symbol* name,
1426                                         const Symbol* signature,
1427                                         OverpassLookupMode overpass_mode,
1428                                         StaticLookupMode static_mode,
1429                                         PrivateLookupMode private_mode) {
1430   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1431   return hit >= 0 ? methods->at(hit): NULL;
1432 }
1433 
1434 // true if method matches signature and conforms to skipping_X conditions.
1435 static bool method_matches(const Method* m,
1436                            const Symbol* signature,
1437                            bool skipping_overpass,
1438                            bool skipping_static,
1439                            bool skipping_private) {
1440   return ((m->signature() == signature) &&
1441     (!skipping_overpass || !m->is_overpass()) &&
1442     (!skipping_static || !m->is_static()) &&
1443     (!skipping_private || !m->is_private()));
1444 }
1445 
1446 // Used directly for default_methods to find the index into the
1447 // default_vtable_indices, and indirectly by find_method
1448 // find_method_index looks in the local methods array to return the index
1449 // of the matching name/signature. If, overpass methods are being ignored,
1450 // the search continues to find a potential non-overpass match.  This capability
1451 // is important during method resolution to prefer a static method, for example,
1452 // over an overpass method.
1453 // There is the possibility in any _method's array to have the same name/signature
1454 // for a static method, an overpass method and a local instance method
1455 // To correctly catch a given method, the search criteria may need
1456 // to explicitly skip the other two. For local instance methods, it
1457 // is often necessary to skip private methods
1458 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1459                                      const Symbol* name,
1460                                      const Symbol* signature,
1461                                      OverpassLookupMode overpass_mode,
1462                                      StaticLookupMode static_mode,
1463                                      PrivateLookupMode private_mode) {
1464   const bool skipping_overpass = (overpass_mode == skip_overpass);
1465   const bool skipping_static = (static_mode == skip_static);
1466   const bool skipping_private = (private_mode == skip_private);
1467   const int hit = binary_search(methods, name);
1468   if (hit != -1) {
1469     const Method* const m = methods->at(hit);
1470 
1471     // Do linear search to find matching signature.  First, quick check
1472     // for common case, ignoring overpasses if requested.
1473     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1474           return hit;
1475     }
1476 
1477     // search downwards through overloaded methods
1478     int i;
1479     for (i = hit - 1; i >= 0; --i) {
1480         const Method* const m = methods->at(i);
1481         assert(m->is_method(), "must be method");
1482         if (m->name() != name) {
1483           break;
1484         }
1485         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1486           return i;
1487         }
1488     }
1489     // search upwards
1490     for (i = hit + 1; i < methods->length(); ++i) {
1491         const Method* const m = methods->at(i);
1492         assert(m->is_method(), "must be method");
1493         if (m->name() != name) {
1494           break;
1495         }
1496         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1497           return i;
1498         }
1499     }
1500     // not found
1501 #ifdef ASSERT
1502     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1503       linear_search(methods, name, signature);
1504     assert(-1 == index, "binary search should have found entry %d", index);
1505 #endif
1506   }
1507   return -1;
1508 }
1509 
1510 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1511   return find_method_by_name(methods(), name, end);
1512 }
1513 
1514 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1515                                        const Symbol* name,
1516                                        int* end_ptr) {
1517   assert(end_ptr != NULL, "just checking");
1518   int start = binary_search(methods, name);
1519   int end = start + 1;
1520   if (start != -1) {
1521     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1522     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1523     *end_ptr = end;
1524     return start;
1525   }
1526   return -1;
1527 }
1528 
1529 // uncached_lookup_method searches both the local class methods array and all
1530 // superclasses methods arrays, skipping any overpass methods in superclasses.
1531 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1532                                               const Symbol* signature,
1533                                               OverpassLookupMode overpass_mode) const {
1534   OverpassLookupMode overpass_local_mode = overpass_mode;
1535   const Klass* klass = this;
1536   while (klass != NULL) {
1537     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1538                                                                         signature,
1539                                                                         overpass_local_mode,
1540                                                                         find_static,
1541                                                                         find_private);
1542     if (method != NULL) {
1543       return method;
1544     }
1545     klass = klass->super();
1546     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1547   }
1548   return NULL;
1549 }
1550 
1551 #ifdef ASSERT
1552 // search through class hierarchy and return true if this class or
1553 // one of the superclasses was redefined
1554 bool InstanceKlass::has_redefined_this_or_super() const {
1555   const Klass* klass = this;
1556   while (klass != NULL) {
1557     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1558       return true;
1559     }
1560     klass = klass->super();
1561   }
1562   return false;
1563 }
1564 #endif
1565 
1566 // lookup a method in the default methods list then in all transitive interfaces
1567 // Do NOT return private or static methods
1568 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1569                                                          Symbol* signature) const {
1570   Method* m = NULL;
1571   if (default_methods() != NULL) {
1572     m = find_method(default_methods(), name, signature);
1573   }
1574   // Look up interfaces
1575   if (m == NULL) {
1576     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1577   }
1578   return m;
1579 }
1580 
1581 // lookup a method in all the interfaces that this class implements
1582 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1583 // They should only be found in the initial InterfaceMethodRef
1584 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1585                                                        Symbol* signature,
1586                                                        DefaultsLookupMode defaults_mode) const {
1587   Array<Klass*>* all_ifs = transitive_interfaces();
1588   int num_ifs = all_ifs->length();
1589   InstanceKlass *ik = NULL;
1590   for (int i = 0; i < num_ifs; i++) {
1591     ik = InstanceKlass::cast(all_ifs->at(i));
1592     Method* m = ik->lookup_method(name, signature);
1593     if (m != NULL && m->is_public() && !m->is_static() &&
1594         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1595       return m;
1596     }
1597   }
1598   return NULL;
1599 }
1600 
1601 /* jni_id_for_impl for jfieldIds only */
1602 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1603   MutexLocker ml(JfieldIdCreation_lock);
1604   // Retry lookup after we got the lock
1605   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1606   if (probe == NULL) {
1607     // Slow case, allocate new static field identifier
1608     probe = new JNIid(this, offset, jni_ids());
1609     set_jni_ids(probe);
1610   }
1611   return probe;
1612 }
1613 
1614 
1615 /* jni_id_for for jfieldIds only */
1616 JNIid* InstanceKlass::jni_id_for(int offset) {
1617   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1618   if (probe == NULL) {
1619     probe = jni_id_for_impl(offset);
1620   }
1621   return probe;
1622 }
1623 
1624 u2 InstanceKlass::enclosing_method_data(int offset) const {
1625   const Array<jushort>* const inner_class_list = inner_classes();
1626   if (inner_class_list == NULL) {
1627     return 0;
1628   }
1629   const int length = inner_class_list->length();
1630   if (length % inner_class_next_offset == 0) {
1631     return 0;
1632   }
1633   const int index = length - enclosing_method_attribute_size;
1634   assert(offset < enclosing_method_attribute_size, "invalid offset");
1635   return inner_class_list->at(index + offset);
1636 }
1637 
1638 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1639                                                  u2 method_index) {
1640   Array<jushort>* inner_class_list = inner_classes();
1641   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1642   int length = inner_class_list->length();
1643   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1644     int index = length - enclosing_method_attribute_size;
1645     inner_class_list->at_put(
1646       index + enclosing_method_class_index_offset, class_index);
1647     inner_class_list->at_put(
1648       index + enclosing_method_method_index_offset, method_index);
1649   }
1650 }
1651 
1652 // Lookup or create a jmethodID.
1653 // This code is called by the VMThread and JavaThreads so the
1654 // locking has to be done very carefully to avoid deadlocks
1655 // and/or other cache consistency problems.
1656 //
1657 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1658   size_t idnum = (size_t)method_h->method_idnum();
1659   jmethodID* jmeths = methods_jmethod_ids_acquire();
1660   size_t length = 0;
1661   jmethodID id = NULL;
1662 
1663   // We use a double-check locking idiom here because this cache is
1664   // performance sensitive. In the normal system, this cache only
1665   // transitions from NULL to non-NULL which is safe because we use
1666   // release_set_methods_jmethod_ids() to advertise the new cache.
1667   // A partially constructed cache should never be seen by a racing
1668   // thread. We also use release_store() to save a new jmethodID
1669   // in the cache so a partially constructed jmethodID should never be
1670   // seen either. Cache reads of existing jmethodIDs proceed without a
1671   // lock, but cache writes of a new jmethodID requires uniqueness and
1672   // creation of the cache itself requires no leaks so a lock is
1673   // generally acquired in those two cases.
1674   //
1675   // If the RedefineClasses() API has been used, then this cache can
1676   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1677   // Cache creation requires no leaks and we require safety between all
1678   // cache accesses and freeing of the old cache so a lock is generally
1679   // acquired when the RedefineClasses() API has been used.
1680 
1681   if (jmeths != NULL) {
1682     // the cache already exists
1683     if (!idnum_can_increment()) {
1684       // the cache can't grow so we can just get the current values
1685       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1686     } else {
1687       // cache can grow so we have to be more careful
1688       if (Threads::number_of_threads() == 0 ||
1689           SafepointSynchronize::is_at_safepoint()) {
1690         // we're single threaded or at a safepoint - no locking needed
1691         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1692       } else {
1693         MutexLocker ml(JmethodIdCreation_lock);
1694         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1695       }
1696     }
1697   }
1698   // implied else:
1699   // we need to allocate a cache so default length and id values are good
1700 
1701   if (jmeths == NULL ||   // no cache yet
1702       length <= idnum ||  // cache is too short
1703       id == NULL) {       // cache doesn't contain entry
1704 
1705     // This function can be called by the VMThread so we have to do all
1706     // things that might block on a safepoint before grabbing the lock.
1707     // Otherwise, we can deadlock with the VMThread or have a cache
1708     // consistency issue. These vars keep track of what we might have
1709     // to free after the lock is dropped.
1710     jmethodID  to_dealloc_id     = NULL;
1711     jmethodID* to_dealloc_jmeths = NULL;
1712 
1713     // may not allocate new_jmeths or use it if we allocate it
1714     jmethodID* new_jmeths = NULL;
1715     if (length <= idnum) {
1716       // allocate a new cache that might be used
1717       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1718       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1719       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1720       // cache size is stored in element[0], other elements offset by one
1721       new_jmeths[0] = (jmethodID)size;
1722     }
1723 
1724     // allocate a new jmethodID that might be used
1725     jmethodID new_id = NULL;
1726     if (method_h->is_old() && !method_h->is_obsolete()) {
1727       // The method passed in is old (but not obsolete), we need to use the current version
1728       Method* current_method = method_with_idnum((int)idnum);
1729       assert(current_method != NULL, "old and but not obsolete, so should exist");
1730       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1731     } else {
1732       // It is the current version of the method or an obsolete method,
1733       // use the version passed in
1734       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1735     }
1736 
1737     if (Threads::number_of_threads() == 0 ||
1738         SafepointSynchronize::is_at_safepoint()) {
1739       // we're single threaded or at a safepoint - no locking needed
1740       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1741                                           &to_dealloc_id, &to_dealloc_jmeths);
1742     } else {
1743       MutexLocker ml(JmethodIdCreation_lock);
1744       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1745                                           &to_dealloc_id, &to_dealloc_jmeths);
1746     }
1747 
1748     // The lock has been dropped so we can free resources.
1749     // Free up either the old cache or the new cache if we allocated one.
1750     if (to_dealloc_jmeths != NULL) {
1751       FreeHeap(to_dealloc_jmeths);
1752     }
1753     // free up the new ID since it wasn't needed
1754     if (to_dealloc_id != NULL) {
1755       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1756     }
1757   }
1758   return id;
1759 }
1760 
1761 // Figure out how many jmethodIDs haven't been allocated, and make
1762 // sure space for them is pre-allocated.  This makes getting all
1763 // method ids much, much faster with classes with more than 8
1764 // methods, and has a *substantial* effect on performance with jvmti
1765 // code that loads all jmethodIDs for all classes.
1766 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1767   int new_jmeths = 0;
1768   int length = methods()->length();
1769   for (int index = start_offset; index < length; index++) {
1770     Method* m = methods()->at(index);
1771     jmethodID id = m->find_jmethod_id_or_null();
1772     if (id == NULL) {
1773       new_jmeths++;
1774     }
1775   }
1776   if (new_jmeths != 0) {
1777     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1778   }
1779 }
1780 
1781 // Common code to fetch the jmethodID from the cache or update the
1782 // cache with the new jmethodID. This function should never do anything
1783 // that causes the caller to go to a safepoint or we can deadlock with
1784 // the VMThread or have cache consistency issues.
1785 //
1786 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1787             size_t idnum, jmethodID new_id,
1788             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1789             jmethodID** to_dealloc_jmeths_p) {
1790   assert(new_id != NULL, "sanity check");
1791   assert(to_dealloc_id_p != NULL, "sanity check");
1792   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1793   assert(Threads::number_of_threads() == 0 ||
1794          SafepointSynchronize::is_at_safepoint() ||
1795          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1796 
1797   // reacquire the cache - we are locked, single threaded or at a safepoint
1798   jmethodID* jmeths = methods_jmethod_ids_acquire();
1799   jmethodID  id     = NULL;
1800   size_t     length = 0;
1801 
1802   if (jmeths == NULL ||                         // no cache yet
1803       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1804     if (jmeths != NULL) {
1805       // copy any existing entries from the old cache
1806       for (size_t index = 0; index < length; index++) {
1807         new_jmeths[index+1] = jmeths[index+1];
1808       }
1809       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1810     }
1811     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1812   } else {
1813     // fetch jmethodID (if any) from the existing cache
1814     id = jmeths[idnum+1];
1815     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1816   }
1817   if (id == NULL) {
1818     // No matching jmethodID in the existing cache or we have a new
1819     // cache or we just grew the cache. This cache write is done here
1820     // by the first thread to win the foot race because a jmethodID
1821     // needs to be unique once it is generally available.
1822     id = new_id;
1823 
1824     // The jmethodID cache can be read while unlocked so we have to
1825     // make sure the new jmethodID is complete before installing it
1826     // in the cache.
1827     OrderAccess::release_store(&jmeths[idnum+1], id);
1828   } else {
1829     *to_dealloc_id_p = new_id; // save new id for later delete
1830   }
1831   return id;
1832 }
1833 
1834 
1835 // Common code to get the jmethodID cache length and the jmethodID
1836 // value at index idnum if there is one.
1837 //
1838 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1839        size_t idnum, size_t *length_p, jmethodID* id_p) {
1840   assert(cache != NULL, "sanity check");
1841   assert(length_p != NULL, "sanity check");
1842   assert(id_p != NULL, "sanity check");
1843 
1844   // cache size is stored in element[0], other elements offset by one
1845   *length_p = (size_t)cache[0];
1846   if (*length_p <= idnum) {  // cache is too short
1847     *id_p = NULL;
1848   } else {
1849     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1850   }
1851 }
1852 
1853 
1854 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1855 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1856   size_t idnum = (size_t)method->method_idnum();
1857   jmethodID* jmeths = methods_jmethod_ids_acquire();
1858   size_t length;                                // length assigned as debugging crumb
1859   jmethodID id = NULL;
1860   if (jmeths != NULL &&                         // If there is a cache
1861       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1862     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1863   }
1864   return id;
1865 }
1866 
1867 inline DependencyContext InstanceKlass::dependencies() {
1868   DependencyContext dep_context(&_dep_context);
1869   return dep_context;
1870 }
1871 
1872 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1873   return dependencies().mark_dependent_nmethods(changes);
1874 }
1875 
1876 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1877   dependencies().add_dependent_nmethod(nm);
1878 }
1879 
1880 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1881   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1882 }
1883 
1884 #ifndef PRODUCT
1885 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1886   dependencies().print_dependent_nmethods(verbose);
1887 }
1888 
1889 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1890   return dependencies().is_dependent_nmethod(nm);
1891 }
1892 #endif //PRODUCT
1893 
1894 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1895   clean_implementors_list(is_alive);
1896   clean_method_data(is_alive);
1897 
1898   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1899   DependencyContext dep_context(&_dep_context);
1900   dep_context.expunge_stale_entries();
1901 }
1902 
1903 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1904   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1905   if (is_interface()) {
1906     if (ClassUnloading) {
1907       Klass* impl = implementor();
1908       if (impl != NULL) {
1909         if (!impl->is_loader_alive(is_alive)) {
1910           // remove this guy
1911           Klass** klass = adr_implementor();
1912           assert(klass != NULL, "null klass");
1913           if (klass != NULL) {
1914             *klass = NULL;
1915           }
1916         }
1917       }
1918     }
1919   }
1920 }
1921 
1922 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1923   for (int m = 0; m < methods()->length(); m++) {
1924     MethodData* mdo = methods()->at(m)->method_data();
1925     if (mdo != NULL) {
1926       mdo->clean_method_data(is_alive);
1927     }
1928   }
1929 }
1930 
1931 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1932   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1933     ResourceMark rm;
1934     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1935     return false;
1936   }
1937 
1938   Array<Klass*>* local_interfaces = this->local_interfaces();
1939   if (local_interfaces != NULL) {
1940     int length = local_interfaces->length();
1941     for (int i = 0; i < length; i++) {
1942       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1943       if (!intf->has_passed_fingerprint_check()) {
1944         ResourceMark rm;
1945         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1946         return false;
1947       }
1948     }
1949   }
1950 
1951   return true;
1952 }
1953 
1954 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
1955 #if INCLUDE_AOT
1956   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1957   if (CalculateClassFingerprint) {
1958     // (1) We are running AOT to generate a shared library.
1959     return true;
1960   }
1961   if (DumpSharedSpaces) {
1962     // (2) We are running -Xshare:dump to create a shared archive
1963     return true;
1964   }
1965   if (UseAOT && is_anonymous) {
1966     // (3) We are using AOT code from a shared library and see an anonymous class
1967     return true;
1968   }
1969 #endif
1970 
1971   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1972   // but do not store the 64-bit fingerprint to save space.
1973   return false;
1974 }
1975 
1976 bool InstanceKlass::has_stored_fingerprint() const {
1977 #if INCLUDE_AOT
1978   return should_store_fingerprint() || is_shared();
1979 #else
1980   return false;
1981 #endif
1982 }
1983 
1984 uint64_t InstanceKlass::get_stored_fingerprint() const {
1985   address adr = adr_fingerprint();
1986   if (adr != NULL) {
1987     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
1988   }
1989   return 0;
1990 }
1991 
1992 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
1993   address adr = adr_fingerprint();
1994   if (adr != NULL) {
1995     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
1996 
1997     ResourceMark rm;
1998     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
1999   }
2000 }
2001 
2002 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2003   Klass::metaspace_pointers_do(it);
2004 
2005   if (log_is_enabled(Trace, cds)) {
2006     ResourceMark rm;
2007     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2008   }
2009 
2010   it->push(&_annotations);
2011   it->push((Klass**)&_array_klasses);
2012   it->push(&_constants);
2013   it->push(&_inner_classes);
2014   it->push(&_array_name);
2015 #if INCLUDE_JVMTI
2016   it->push(&_previous_versions);
2017 #endif
2018   it->push(&_methods);
2019   it->push(&_default_methods);
2020   it->push(&_local_interfaces);
2021   it->push(&_transitive_interfaces);
2022   it->push(&_method_ordering);
2023   it->push(&_default_vtable_indices);
2024   it->push(&_fields);
2025 
2026   if (itable_length() > 0) {
2027     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2028     int method_table_offset_in_words = ioe->offset()/wordSize;
2029     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2030                          / itableOffsetEntry::size();
2031 
2032     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2033       if (ioe->interface_klass() != NULL) {
2034         it->push(ioe->interface_klass_addr());
2035         itableMethodEntry* ime = ioe->first_method_entry(this);
2036         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2037         for (int index = 0; index < n; index ++) {
2038           it->push(ime[index].method_addr());
2039         }
2040       }
2041     }
2042   }
2043 }
2044 
2045 void InstanceKlass::remove_unshareable_info() {
2046   Klass::remove_unshareable_info();
2047 
2048   if (is_in_error_state()) {
2049     // Classes are attempted to link during dumping and may fail,
2050     // but these classes are still in the dictionary and class list in CLD.
2051     // Check in_error state first because in_error is > linked state, so
2052     // is_linked() is true.
2053     // If there's a linking error, there is nothing else to remove.
2054     return;
2055   }
2056 
2057   // Unlink the class
2058   if (is_linked()) {
2059     unlink_class();
2060   }
2061   init_implementor();
2062 
2063   constants()->remove_unshareable_info();
2064 
2065   for (int i = 0; i < methods()->length(); i++) {
2066     Method* m = methods()->at(i);
2067     m->remove_unshareable_info();
2068   }
2069 
2070   // do array classes also.
2071   if (array_klasses() != NULL) {
2072     array_klasses()->remove_unshareable_info();
2073   }
2074 
2075   // These are not allocated from metaspace, but they should should all be empty
2076   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2077   guarantee(_source_debug_extension == NULL, "must be");
2078   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2079   guarantee(_osr_nmethods_head == NULL, "must be");
2080 
2081 #if INCLUDE_JVMTI
2082   guarantee(_breakpoints == NULL, "must be");
2083   guarantee(_previous_versions == NULL, "must be");
2084 #endif
2085 
2086  _init_thread = NULL;
2087  _methods_jmethod_ids = NULL;
2088  _jni_ids = NULL;
2089  _oop_map_cache = NULL;
2090 }
2091 
2092 void InstanceKlass::remove_java_mirror() {
2093   Klass::remove_java_mirror();
2094 
2095   // do array classes also.
2096   if (array_klasses() != NULL) {
2097     array_klasses()->remove_java_mirror();
2098   }
2099 }
2100 
2101 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2102   set_package(loader_data, CHECK);
2103   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2104 
2105   Array<Method*>* methods = this->methods();
2106   int num_methods = methods->length();
2107   for (int index2 = 0; index2 < num_methods; ++index2) {
2108     methodHandle m(THREAD, methods->at(index2));
2109     m->restore_unshareable_info(CHECK);
2110   }
2111   if (JvmtiExport::has_redefined_a_class()) {
2112     // Reinitialize vtable because RedefineClasses may have changed some
2113     // entries in this vtable for super classes so the CDS vtable might
2114     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2115     // vtables in the shared system dictionary, only the main one.
2116     // It also redefines the itable too so fix that too.
2117     ResourceMark rm(THREAD);
2118     vtable().initialize_vtable(false, CHECK);
2119     itable().initialize_itable(false, CHECK);
2120   }
2121 
2122   // restore constant pool resolved references
2123   constants()->restore_unshareable_info(CHECK);
2124 
2125   if (array_klasses() != NULL) {
2126     // Array classes have null protection domain.
2127     // --> see ArrayKlass::complete_create_array_klass()
2128     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2129   }
2130 }
2131 
2132 // returns true IFF is_in_error_state() has been changed as a result of this call.
2133 bool InstanceKlass::check_sharing_error_state() {
2134   assert(DumpSharedSpaces, "should only be called during dumping");
2135   bool old_state = is_in_error_state();
2136 
2137   if (!is_in_error_state()) {
2138     bool bad = false;
2139     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2140       if (sup->is_in_error_state()) {
2141         bad = true;
2142         break;
2143       }
2144     }
2145     if (!bad) {
2146       Array<Klass*>* interfaces = transitive_interfaces();
2147       for (int i = 0; i < interfaces->length(); i++) {
2148         Klass* iface = interfaces->at(i);
2149         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2150           bad = true;
2151           break;
2152         }
2153       }
2154     }
2155 
2156     if (bad) {
2157       set_in_error_state();
2158     }
2159   }
2160 
2161   return (old_state != is_in_error_state());
2162 }
2163 
2164 #if INCLUDE_JVMTI
2165 static void clear_all_breakpoints(Method* m) {
2166   m->clear_all_breakpoints();
2167 }
2168 #endif
2169 
2170 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2171   // notify the debugger
2172   if (JvmtiExport::should_post_class_unload()) {
2173     JvmtiExport::post_class_unload(ik);
2174   }
2175 
2176   // notify ClassLoadingService of class unload
2177   ClassLoadingService::notify_class_unloaded(ik);
2178 }
2179 
2180 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2181   // Clean up C heap
2182   ik->release_C_heap_structures();
2183   ik->constants()->release_C_heap_structures();
2184 }
2185 
2186 void InstanceKlass::release_C_heap_structures() {
2187   // Can't release the constant pool here because the constant pool can be
2188   // deallocated separately from the InstanceKlass for default methods and
2189   // redefine classes.
2190 
2191   // Deallocate oop map cache
2192   if (_oop_map_cache != NULL) {
2193     delete _oop_map_cache;
2194     _oop_map_cache = NULL;
2195   }
2196 
2197   // Deallocate JNI identifiers for jfieldIDs
2198   JNIid::deallocate(jni_ids());
2199   set_jni_ids(NULL);
2200 
2201   jmethodID* jmeths = methods_jmethod_ids_acquire();
2202   if (jmeths != (jmethodID*)NULL) {
2203     release_set_methods_jmethod_ids(NULL);
2204     FreeHeap(jmeths);
2205   }
2206 
2207   // Release dependencies.
2208   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2209   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2210   // context can contain live dependencies, since there's a race between nmethod &
2211   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2212   // dependencies aren't removed from the context associated with the class (see
2213   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2214   // live dependencies pointing to unloaded nmethods and causes a crash in
2215   // DC::remove_all_dependents() when it touches unloaded nmethod.
2216   dependencies().wipe();
2217 
2218 #if INCLUDE_JVMTI
2219   // Deallocate breakpoint records
2220   if (breakpoints() != 0x0) {
2221     methods_do(clear_all_breakpoints);
2222     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2223   }
2224 
2225   // deallocate the cached class file
2226   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
2227     os::free(_cached_class_file);
2228     _cached_class_file = NULL;
2229   }
2230 #endif
2231 
2232   // Decrement symbol reference counts associated with the unloaded class.
2233   if (_name != NULL) _name->decrement_refcount();
2234   // unreference array name derived from this class name (arrays of an unloaded
2235   // class can't be referenced anymore).
2236   if (_array_name != NULL)  _array_name->decrement_refcount();
2237   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2238 }
2239 
2240 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2241   if (array == NULL) {
2242     _source_debug_extension = NULL;
2243   } else {
2244     // Adding one to the attribute length in order to store a null terminator
2245     // character could cause an overflow because the attribute length is
2246     // already coded with an u4 in the classfile, but in practice, it's
2247     // unlikely to happen.
2248     assert((length+1) > length, "Overflow checking");
2249     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2250     for (int i = 0; i < length; i++) {
2251       sde[i] = array[i];
2252     }
2253     sde[length] = '\0';
2254     _source_debug_extension = sde;
2255   }
2256 }
2257 
2258 const char* InstanceKlass::signature_name() const {
2259   int hash_len = 0;
2260   char hash_buf[40];
2261 
2262   // If this is an anonymous class, append a hash to make the name unique
2263   if (is_anonymous()) {
2264     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2265     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2266     hash_len = (int)strlen(hash_buf);
2267   }
2268 
2269   // Get the internal name as a c string
2270   const char* src = (const char*) (name()->as_C_string());
2271   const int src_length = (int)strlen(src);
2272 
2273   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2274 
2275   // Add L as type indicator
2276   int dest_index = 0;
2277   dest[dest_index++] = 'L';
2278 
2279   // Add the actual class name
2280   for (int src_index = 0; src_index < src_length; ) {
2281     dest[dest_index++] = src[src_index++];
2282   }
2283 
2284   // If we have a hash, append it
2285   for (int hash_index = 0; hash_index < hash_len; ) {
2286     dest[dest_index++] = hash_buf[hash_index++];
2287   }
2288 
2289   // Add the semicolon and the NULL
2290   dest[dest_index++] = ';';
2291   dest[dest_index] = '\0';
2292   return dest;
2293 }
2294 
2295 // Used to obtain the package name from a fully qualified class name.
2296 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2297   if (name == NULL) {
2298     return NULL;
2299   } else {
2300     if (name->utf8_length() <= 0) {
2301       return NULL;
2302     }
2303     ResourceMark rm;
2304     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2305     if (package_name == NULL) {
2306       return NULL;
2307     }
2308     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2309     return pkg_name;
2310   }
2311 }
2312 
2313 ModuleEntry* InstanceKlass::module() const {
2314   if (!in_unnamed_package()) {
2315     return _package_entry->module();
2316   }
2317   const Klass* host = host_klass();
2318   if (host == NULL) {
2319     return class_loader_data()->unnamed_module();
2320   }
2321   return host->class_loader_data()->unnamed_module();
2322 }
2323 
2324 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2325 
2326   // ensure java/ packages only loaded by boot or platform builtin loaders
2327   Handle class_loader(THREAD, loader_data->class_loader());
2328   check_prohibited_package(name(), class_loader, CHECK);
2329 
2330   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2331 
2332   if (pkg_name != NULL && loader_data != NULL) {
2333 
2334     // Find in class loader's package entry table.
2335     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2336 
2337     // If the package name is not found in the loader's package
2338     // entry table, it is an indication that the package has not
2339     // been defined. Consider it defined within the unnamed module.
2340     if (_package_entry == NULL) {
2341       ResourceMark rm;
2342 
2343       if (!ModuleEntryTable::javabase_defined()) {
2344         // Before java.base is defined during bootstrapping, define all packages in
2345         // the java.base module.  If a non-java.base package is erroneously placed
2346         // in the java.base module it will be caught later when java.base
2347         // is defined by ModuleEntryTable::verify_javabase_packages check.
2348         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2349         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2350       } else {
2351         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2352         _package_entry = loader_data->packages()->lookup(pkg_name,
2353                                                          loader_data->unnamed_module());
2354       }
2355 
2356       // A package should have been successfully created
2357       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2358              name()->as_C_string(), loader_data->loader_name());
2359     }
2360 
2361     if (log_is_enabled(Debug, module)) {
2362       ResourceMark rm;
2363       ModuleEntry* m = _package_entry->module();
2364       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2365                         external_name(),
2366                         pkg_name->as_C_string(),
2367                         loader_data->loader_name(),
2368                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2369     }
2370   } else {
2371     ResourceMark rm;
2372     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2373                       external_name(),
2374                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2375                       UNNAMED_MODULE);
2376   }
2377 }
2378 
2379 
2380 // different versions of is_same_class_package
2381 
2382 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2383   oop classloader1 = this->class_loader();
2384   PackageEntry* classpkg1 = this->package();
2385   if (class2->is_objArray_klass()) {
2386     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2387   }
2388 
2389   oop classloader2;
2390   PackageEntry* classpkg2;
2391   if (class2->is_instance_klass()) {
2392     classloader2 = class2->class_loader();
2393     classpkg2 = class2->package();
2394   } else {
2395     assert(class2->is_typeArray_klass(), "should be type array");
2396     classloader2 = NULL;
2397     classpkg2 = NULL;
2398   }
2399 
2400   // Same package is determined by comparing class loader
2401   // and package entries. Both must be the same. This rule
2402   // applies even to classes that are defined in the unnamed
2403   // package, they still must have the same class loader.
2404   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2405     return true;
2406   }
2407 
2408   return false;
2409 }
2410 
2411 // return true if this class and other_class are in the same package. Classloader
2412 // and classname information is enough to determine a class's package
2413 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2414                                           const Symbol* other_class_name) const {
2415   if (class_loader() != other_class_loader) {
2416     return false;
2417   }
2418   if (name()->fast_compare(other_class_name) == 0) {
2419      return true;
2420   }
2421 
2422   {
2423     ResourceMark rm;
2424 
2425     bool bad_class_name = false;
2426     const char* other_pkg =
2427       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2428     if (bad_class_name) {
2429       return false;
2430     }
2431     // Check that package_from_name() returns NULL, not "", if there is no package.
2432     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2433 
2434     const Symbol* const this_package_name =
2435       this->package() != NULL ? this->package()->name() : NULL;
2436 
2437     if (this_package_name == NULL || other_pkg == NULL) {
2438       // One of the two doesn't have a package.  Only return true if the other
2439       // one also doesn't have a package.
2440       return (const char*)this_package_name == other_pkg;
2441     }
2442 
2443     // Check if package is identical
2444     return this_package_name->equals(other_pkg);
2445   }
2446 }
2447 
2448 // Returns true iff super_method can be overridden by a method in targetclassname
2449 // See JLS 3rd edition 8.4.6.1
2450 // Assumes name-signature match
2451 // "this" is InstanceKlass of super_method which must exist
2452 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2453 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2454    // Private methods can not be overridden
2455    if (super_method->is_private()) {
2456      return false;
2457    }
2458    // If super method is accessible, then override
2459    if ((super_method->is_protected()) ||
2460        (super_method->is_public())) {
2461      return true;
2462    }
2463    // Package-private methods are not inherited outside of package
2464    assert(super_method->is_package_private(), "must be package private");
2465    return(is_same_class_package(targetclassloader(), targetclassname));
2466 }
2467 
2468 // Only boot and platform class loaders can define classes in "java/" packages.
2469 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2470                                              Handle class_loader,
2471                                              TRAPS) {
2472   if (!class_loader.is_null() &&
2473       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2474       class_name != NULL) {
2475     ResourceMark rm(THREAD);
2476     char* name = class_name->as_C_string();
2477     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2478       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2479       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2480       name = pkg_name->as_C_string();
2481       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2482       StringUtils::replace_no_expand(name, "/", ".");
2483       const char* msg_text1 = "Class loader (instance of): ";
2484       const char* msg_text2 = " tried to load prohibited package name: ";
2485       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2486       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2487       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2488       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2489     }
2490   }
2491   return;
2492 }
2493 
2494 // tell if two classes have the same enclosing class (at package level)
2495 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2496   if (class2 == this) return true;
2497   if (!class2->is_instance_klass())  return false;
2498 
2499   // must be in same package before we try anything else
2500   if (!is_same_class_package(class2))
2501     return false;
2502 
2503   // As long as there is an outer_this.getEnclosingClass,
2504   // shift the search outward.
2505   const InstanceKlass* outer_this = this;
2506   for (;;) {
2507     // As we walk along, look for equalities between outer_this and class2.
2508     // Eventually, the walks will terminate as outer_this stops
2509     // at the top-level class around the original class.
2510     bool ignore_inner_is_member;
2511     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2512                                                             CHECK_false);
2513     if (next == NULL)  break;
2514     if (next == class2)  return true;
2515     outer_this = InstanceKlass::cast(next);
2516   }
2517 
2518   // Now do the same for class2.
2519   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2520   for (;;) {
2521     bool ignore_inner_is_member;
2522     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2523                                                     CHECK_false);
2524     if (next == NULL)  break;
2525     // Might as well check the new outer against all available values.
2526     if (next == this)  return true;
2527     if (next == outer_this)  return true;
2528     outer2 = InstanceKlass::cast(next);
2529   }
2530 
2531   // If by this point we have not found an equality between the
2532   // two classes, we know they are in separate package members.
2533   return false;
2534 }
2535 
2536 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2537   constantPoolHandle i_cp(THREAD, constants());
2538   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2539     int ioff = iter.inner_class_info_index();
2540     if (ioff != 0) {
2541       // Check to see if the name matches the class we're looking for
2542       // before attempting to find the class.
2543       if (i_cp->klass_name_at_matches(this, ioff)) {
2544         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2545         if (this == inner_klass) {
2546           *ooff = iter.outer_class_info_index();
2547           *noff = iter.inner_name_index();
2548           return true;
2549         }
2550       }
2551     }
2552   }
2553   return false;
2554 }
2555 
2556 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2557   InstanceKlass* outer_klass = NULL;
2558   *inner_is_member = false;
2559   int ooff = 0, noff = 0;
2560   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2561   if (has_inner_classes_attr) {
2562     constantPoolHandle i_cp(THREAD, constants());
2563     if (ooff != 0) {
2564       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2565       outer_klass = InstanceKlass::cast(ok);
2566       *inner_is_member = true;
2567     }
2568     if (NULL == outer_klass) {
2569       // It may be anonymous; try for that.
2570       int encl_method_class_idx = enclosing_method_class_index();
2571       if (encl_method_class_idx != 0) {
2572         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2573         outer_klass = InstanceKlass::cast(ok);
2574         *inner_is_member = false;
2575       }
2576     }
2577   }
2578 
2579   // If no inner class attribute found for this class.
2580   if (NULL == outer_klass) return NULL;
2581 
2582   // Throws an exception if outer klass has not declared k as an inner klass
2583   // We need evidence that each klass knows about the other, or else
2584   // the system could allow a spoof of an inner class to gain access rights.
2585   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2586   return outer_klass;
2587 }
2588 
2589 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2590   jint access = access_flags().as_int();
2591 
2592   // But check if it happens to be member class.
2593   InnerClassesIterator iter(this);
2594   for (; !iter.done(); iter.next()) {
2595     int ioff = iter.inner_class_info_index();
2596     // Inner class attribute can be zero, skip it.
2597     // Strange but true:  JVM spec. allows null inner class refs.
2598     if (ioff == 0) continue;
2599 
2600     // only look at classes that are already loaded
2601     // since we are looking for the flags for our self.
2602     Symbol* inner_name = constants()->klass_name_at(ioff);
2603     if (name() == inner_name) {
2604       // This is really a member class.
2605       access = iter.inner_access_flags();
2606       break;
2607     }
2608   }
2609   // Remember to strip ACC_SUPER bit
2610   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2611 }
2612 
2613 jint InstanceKlass::jvmti_class_status() const {
2614   jint result = 0;
2615 
2616   if (is_linked()) {
2617     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2618   }
2619 
2620   if (is_initialized()) {
2621     assert(is_linked(), "Class status is not consistent");
2622     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2623   }
2624   if (is_in_error_state()) {
2625     result |= JVMTI_CLASS_STATUS_ERROR;
2626   }
2627   return result;
2628 }
2629 
2630 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2631   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2632   int method_table_offset_in_words = ioe->offset()/wordSize;
2633   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2634                        / itableOffsetEntry::size();
2635 
2636   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2637     // If the interface isn't implemented by the receiver class,
2638     // the VM should throw IncompatibleClassChangeError.
2639     if (cnt >= nof_interfaces) {
2640       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2641     }
2642 
2643     Klass* ik = ioe->interface_klass();
2644     if (ik == holder) break;
2645   }
2646 
2647   itableMethodEntry* ime = ioe->first_method_entry(this);
2648   Method* m = ime[index].method();
2649   if (m == NULL) {
2650     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2651   }
2652   return m;
2653 }
2654 
2655 
2656 #if INCLUDE_JVMTI
2657 // update default_methods for redefineclasses for methods that are
2658 // not yet in the vtable due to concurrent subclass define and superinterface
2659 // redefinition
2660 // Note: those in the vtable, should have been updated via adjust_method_entries
2661 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2662   // search the default_methods for uses of either obsolete or EMCP methods
2663   if (default_methods() != NULL) {
2664     for (int index = 0; index < default_methods()->length(); index ++) {
2665       Method* old_method = default_methods()->at(index);
2666       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2667         continue; // skip uninteresting entries
2668       }
2669       assert(!old_method->is_deleted(), "default methods may not be deleted");
2670 
2671       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2672 
2673       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2674       assert(old_method != new_method, "sanity check");
2675 
2676       default_methods()->at_put(index, new_method);
2677       if (log_is_enabled(Info, redefine, class, update)) {
2678         ResourceMark rm;
2679         if (!(*trace_name_printed)) {
2680           log_info(redefine, class, update)
2681             ("adjust: klassname=%s default methods from name=%s",
2682              external_name(), old_method->method_holder()->external_name());
2683           *trace_name_printed = true;
2684         }
2685         log_debug(redefine, class, update, vtables)
2686           ("default method update: %s(%s) ",
2687            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2688       }
2689     }
2690   }
2691 }
2692 #endif // INCLUDE_JVMTI
2693 
2694 // On-stack replacement stuff
2695 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2696   // only one compilation can be active
2697   {
2698     // This is a short non-blocking critical region, so the no safepoint check is ok.
2699     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2700     assert(n->is_osr_method(), "wrong kind of nmethod");
2701     n->set_osr_link(osr_nmethods_head());
2702     set_osr_nmethods_head(n);
2703     // Raise the highest osr level if necessary
2704     if (TieredCompilation) {
2705       Method* m = n->method();
2706       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2707     }
2708   }
2709 
2710   // Get rid of the osr methods for the same bci that have lower levels.
2711   if (TieredCompilation) {
2712     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2713       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2714       if (inv != NULL && inv->is_in_use()) {
2715         inv->make_not_entrant();
2716       }
2717     }
2718   }
2719 }
2720 
2721 // Remove osr nmethod from the list. Return true if found and removed.
2722 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2723   // This is a short non-blocking critical region, so the no safepoint check is ok.
2724   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2725   assert(n->is_osr_method(), "wrong kind of nmethod");
2726   nmethod* last = NULL;
2727   nmethod* cur  = osr_nmethods_head();
2728   int max_level = CompLevel_none;  // Find the max comp level excluding n
2729   Method* m = n->method();
2730   // Search for match
2731   bool found = false;
2732   while(cur != NULL && cur != n) {
2733     if (TieredCompilation && m == cur->method()) {
2734       // Find max level before n
2735       max_level = MAX2(max_level, cur->comp_level());
2736     }
2737     last = cur;
2738     cur = cur->osr_link();
2739   }
2740   nmethod* next = NULL;
2741   if (cur == n) {
2742     found = true;
2743     next = cur->osr_link();
2744     if (last == NULL) {
2745       // Remove first element
2746       set_osr_nmethods_head(next);
2747     } else {
2748       last->set_osr_link(next);
2749     }
2750   }
2751   n->set_osr_link(NULL);
2752   if (TieredCompilation) {
2753     cur = next;
2754     while (cur != NULL) {
2755       // Find max level after n
2756       if (m == cur->method()) {
2757         max_level = MAX2(max_level, cur->comp_level());
2758       }
2759       cur = cur->osr_link();
2760     }
2761     m->set_highest_osr_comp_level(max_level);
2762   }
2763   return found;
2764 }
2765 
2766 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2767   // This is a short non-blocking critical region, so the no safepoint check is ok.
2768   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2769   nmethod* osr = osr_nmethods_head();
2770   int found = 0;
2771   while (osr != NULL) {
2772     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2773     if (osr->method() == m) {
2774       osr->mark_for_deoptimization();
2775       found++;
2776     }
2777     osr = osr->osr_link();
2778   }
2779   return found;
2780 }
2781 
2782 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2783   // This is a short non-blocking critical region, so the no safepoint check is ok.
2784   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2785   nmethod* osr = osr_nmethods_head();
2786   nmethod* best = NULL;
2787   while (osr != NULL) {
2788     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2789     // There can be a time when a c1 osr method exists but we are waiting
2790     // for a c2 version. When c2 completes its osr nmethod we will trash
2791     // the c1 version and only be able to find the c2 version. However
2792     // while we overflow in the c1 code at back branches we don't want to
2793     // try and switch to the same code as we are already running
2794 
2795     if (osr->method() == m &&
2796         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2797       if (match_level) {
2798         if (osr->comp_level() == comp_level) {
2799           // Found a match - return it.
2800           return osr;
2801         }
2802       } else {
2803         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2804           if (osr->comp_level() == CompLevel_highest_tier) {
2805             // Found the best possible - return it.
2806             return osr;
2807           }
2808           best = osr;
2809         }
2810       }
2811     }
2812     osr = osr->osr_link();
2813   }
2814   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2815     return best;
2816   }
2817   return NULL;
2818 }
2819 
2820 // -----------------------------------------------------------------------------------------------------
2821 // Printing
2822 
2823 #ifndef PRODUCT
2824 
2825 #define BULLET  " - "
2826 
2827 static const char* state_names[] = {
2828   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2829 };
2830 
2831 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2832   for (int i = 0; i < len; i++) {
2833     intptr_t e = start[i];
2834     st->print("%d : " INTPTR_FORMAT, i, e);
2835     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2836       st->print(" ");
2837       ((Metadata*)e)->print_value_on(st);
2838     }
2839     st->cr();
2840   }
2841 }
2842 
2843 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2844   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2845 }
2846 
2847 void InstanceKlass::print_on(outputStream* st) const {
2848   assert(is_klass(), "must be klass");
2849   Klass::print_on(st);
2850 
2851   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2852   st->print(BULLET"klass size:        %d", size());                               st->cr();
2853   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2854   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2855   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2856   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2857   st->print(BULLET"sub:               ");
2858   Klass* sub = subklass();
2859   int n;
2860   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2861     if (n < MaxSubklassPrintSize) {
2862       sub->print_value_on(st);
2863       st->print("   ");
2864     }
2865   }
2866   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2867   st->cr();
2868 
2869   if (is_interface()) {
2870     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2871     if (nof_implementors() == 1) {
2872       st->print_cr(BULLET"implementor:    ");
2873       st->print("   ");
2874       implementor()->print_value_on(st);
2875       st->cr();
2876     }
2877   }
2878 
2879   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2880   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2881   if (Verbose || WizardMode) {
2882     Array<Method*>* method_array = methods();
2883     for (int i = 0; i < method_array->length(); i++) {
2884       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2885     }
2886   }
2887   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2888   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2889   if (Verbose && default_methods() != NULL) {
2890     Array<Method*>* method_array = default_methods();
2891     for (int i = 0; i < method_array->length(); i++) {
2892       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2893     }
2894   }
2895   if (default_vtable_indices() != NULL) {
2896     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2897   }
2898   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2899   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2900   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2901   if (class_loader_data() != NULL) {
2902     st->print(BULLET"class loader data:  ");
2903     class_loader_data()->print_value_on(st);
2904     st->cr();
2905   }
2906   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2907   if (source_file_name() != NULL) {
2908     st->print(BULLET"source file:       ");
2909     source_file_name()->print_value_on(st);
2910     st->cr();
2911   }
2912   if (source_debug_extension() != NULL) {
2913     st->print(BULLET"source debug extension:       ");
2914     st->print("%s", source_debug_extension());
2915     st->cr();
2916   }
2917   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2918   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2919   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2920   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2921   {
2922     bool have_pv = false;
2923     // previous versions are linked together through the InstanceKlass
2924     for (InstanceKlass* pv_node = previous_versions();
2925          pv_node != NULL;
2926          pv_node = pv_node->previous_versions()) {
2927       if (!have_pv)
2928         st->print(BULLET"previous version:  ");
2929       have_pv = true;
2930       pv_node->constants()->print_value_on(st);
2931     }
2932     if (have_pv) st->cr();
2933   }
2934 
2935   if (generic_signature() != NULL) {
2936     st->print(BULLET"generic signature: ");
2937     generic_signature()->print_value_on(st);
2938     st->cr();
2939   }
2940   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2941   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2942   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2943   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2944   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2945   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2946   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2947   FieldPrinter print_static_field(st);
2948   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2949   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2950   FieldPrinter print_nonstatic_field(st);
2951   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2952   ik->do_nonstatic_fields(&print_nonstatic_field);
2953 
2954   st->print(BULLET"non-static oop maps: ");
2955   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2956   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2957   while (map < end_map) {
2958     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2959     map++;
2960   }
2961   st->cr();
2962 }
2963 
2964 #endif //PRODUCT
2965 
2966 void InstanceKlass::print_value_on(outputStream* st) const {
2967   assert(is_klass(), "must be klass");
2968   if (Verbose || WizardMode)  access_flags().print_on(st);
2969   name()->print_value_on(st);
2970 }
2971 
2972 #ifndef PRODUCT
2973 
2974 void FieldPrinter::do_field(fieldDescriptor* fd) {
2975   _st->print(BULLET);
2976    if (_obj == NULL) {
2977      fd->print_on(_st);
2978      _st->cr();
2979    } else {
2980      fd->print_on_for(_st, _obj);
2981      _st->cr();
2982    }
2983 }
2984 
2985 
2986 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2987   Klass::oop_print_on(obj, st);
2988 
2989   if (this == SystemDictionary::String_klass()) {
2990     typeArrayOop value  = java_lang_String::value(obj);
2991     juint        length = java_lang_String::length(obj);
2992     if (value != NULL &&
2993         value->is_typeArray() &&
2994         length <= (juint) value->length()) {
2995       st->print(BULLET"string: ");
2996       java_lang_String::print(obj, st);
2997       st->cr();
2998       if (!WizardMode)  return;  // that is enough
2999     }
3000   }
3001 
3002   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3003   FieldPrinter print_field(st, obj);
3004   do_nonstatic_fields(&print_field);
3005 
3006   if (this == SystemDictionary::Class_klass()) {
3007     st->print(BULLET"signature: ");
3008     java_lang_Class::print_signature(obj, st);
3009     st->cr();
3010     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3011     st->print(BULLET"fake entry for mirror: ");
3012     mirrored_klass->print_value_on_maybe_null(st);
3013     st->cr();
3014     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3015     st->print(BULLET"fake entry for array: ");
3016     array_klass->print_value_on_maybe_null(st);
3017     st->cr();
3018     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3019     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3020     Klass* real_klass = java_lang_Class::as_Klass(obj);
3021     if (real_klass != NULL && real_klass->is_instance_klass()) {
3022       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3023     }
3024   } else if (this == SystemDictionary::MethodType_klass()) {
3025     st->print(BULLET"signature: ");
3026     java_lang_invoke_MethodType::print_signature(obj, st);
3027     st->cr();
3028   }
3029 }
3030 
3031 #endif //PRODUCT
3032 
3033 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3034   st->print("a ");
3035   name()->print_value_on(st);
3036   obj->print_address_on(st);
3037   if (this == SystemDictionary::String_klass()
3038       && java_lang_String::value(obj) != NULL) {
3039     ResourceMark rm;
3040     int len = java_lang_String::length(obj);
3041     int plen = (len < 24 ? len : 12);
3042     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3043     st->print(" = \"%s\"", str);
3044     if (len > plen)
3045       st->print("...[%d]", len);
3046   } else if (this == SystemDictionary::Class_klass()) {
3047     Klass* k = java_lang_Class::as_Klass(obj);
3048     st->print(" = ");
3049     if (k != NULL) {
3050       k->print_value_on(st);
3051     } else {
3052       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3053       st->print("%s", tname ? tname : "type?");
3054     }
3055   } else if (this == SystemDictionary::MethodType_klass()) {
3056     st->print(" = ");
3057     java_lang_invoke_MethodType::print_signature(obj, st);
3058   } else if (java_lang_boxing_object::is_instance(obj)) {
3059     st->print(" = ");
3060     java_lang_boxing_object::print(obj, st);
3061   } else if (this == SystemDictionary::LambdaForm_klass()) {
3062     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3063     if (vmentry != NULL) {
3064       st->print(" => ");
3065       vmentry->print_value_on(st);
3066     }
3067   } else if (this == SystemDictionary::MemberName_klass()) {
3068     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3069     if (vmtarget != NULL) {
3070       st->print(" = ");
3071       vmtarget->print_value_on(st);
3072     } else {
3073       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3074       st->print(".");
3075       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3076     }
3077   }
3078 }
3079 
3080 const char* InstanceKlass::internal_name() const {
3081   return external_name();
3082 }
3083 
3084 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3085                                              const char* module_name,
3086                                              const ClassFileStream* cfs) const {
3087   if (!log_is_enabled(Info, class, load)) {
3088     return;
3089   }
3090 
3091   ResourceMark rm;
3092   LogMessage(class, load) msg;
3093   stringStream info_stream;
3094 
3095   // Name and class hierarchy info
3096   info_stream.print("%s", external_name());
3097 
3098   // Source
3099   if (cfs != NULL) {
3100     if (cfs->source() != NULL) {
3101       if (module_name != NULL) {
3102         if (ClassLoader::is_modules_image(cfs->source())) {
3103           info_stream.print(" source: jrt:/%s", module_name);
3104         } else {
3105           info_stream.print(" source: %s", cfs->source());
3106         }
3107       } else {
3108         info_stream.print(" source: %s", cfs->source());
3109       }
3110     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3111       Thread* THREAD = Thread::current();
3112       Klass* caller =
3113             THREAD->is_Java_thread()
3114                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3115                 : NULL;
3116       // caller can be NULL, for example, during a JVMTI VM_Init hook
3117       if (caller != NULL) {
3118         info_stream.print(" source: instance of %s", caller->external_name());
3119       } else {
3120         // source is unknown
3121       }
3122     } else {
3123       oop class_loader = loader_data->class_loader();
3124       info_stream.print(" source: %s", class_loader->klass()->external_name());
3125     }
3126   } else {
3127     info_stream.print(" source: shared objects file");
3128   }
3129 
3130   msg.info("%s", info_stream.as_string());
3131 
3132   if (log_is_enabled(Debug, class, load)) {
3133     stringStream debug_stream;
3134 
3135     // Class hierarchy info
3136     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3137                        p2i(this),  p2i(superklass()));
3138 
3139     // Interfaces
3140     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3141       debug_stream.print(" interfaces:");
3142       int length = local_interfaces()->length();
3143       for (int i = 0; i < length; i++) {
3144         debug_stream.print(" " INTPTR_FORMAT,
3145                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3146       }
3147     }
3148 
3149     // Class loader
3150     debug_stream.print(" loader: [");
3151     loader_data->print_value_on(&debug_stream);
3152     debug_stream.print("]");
3153 
3154     // Classfile checksum
3155     if (cfs) {
3156       debug_stream.print(" bytes: %d checksum: %08x",
3157                          cfs->length(),
3158                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3159                          cfs->length()));
3160     }
3161 
3162     msg.debug("%s", debug_stream.as_string());
3163   }
3164 }
3165 
3166 #if INCLUDE_SERVICES
3167 // Size Statistics
3168 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3169   Klass::collect_statistics(sz);
3170 
3171   sz->_inst_size  = wordSize * size_helper();
3172   sz->_vtab_bytes = wordSize * vtable_length();
3173   sz->_itab_bytes = wordSize * itable_length();
3174   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3175 
3176   int n = 0;
3177   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3178   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3179   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3180   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3181   n += (sz->_fields_bytes                = sz->count_array(fields()));
3182   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3183   sz->_ro_bytes += n;
3184 
3185   const ConstantPool* cp = constants();
3186   if (cp) {
3187     cp->collect_statistics(sz);
3188   }
3189 
3190   const Annotations* anno = annotations();
3191   if (anno) {
3192     anno->collect_statistics(sz);
3193   }
3194 
3195   const Array<Method*>* methods_array = methods();
3196   if (methods()) {
3197     for (int i = 0; i < methods_array->length(); i++) {
3198       Method* method = methods_array->at(i);
3199       if (method) {
3200         sz->_method_count ++;
3201         method->collect_statistics(sz);
3202       }
3203     }
3204   }
3205 }
3206 #endif // INCLUDE_SERVICES
3207 
3208 // Verification
3209 
3210 class VerifyFieldClosure: public OopClosure {
3211  protected:
3212   template <class T> void do_oop_work(T* p) {
3213     oop obj = RawAccess<>::oop_load(p);
3214     if (!oopDesc::is_oop_or_null(obj)) {
3215       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3216       Universe::print_on(tty);
3217       guarantee(false, "boom");
3218     }
3219   }
3220  public:
3221   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3222   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3223 };
3224 
3225 void InstanceKlass::verify_on(outputStream* st) {
3226 #ifndef PRODUCT
3227   // Avoid redundant verifies, this really should be in product.
3228   if (_verify_count == Universe::verify_count()) return;
3229   _verify_count = Universe::verify_count();
3230 #endif
3231 
3232   // Verify Klass
3233   Klass::verify_on(st);
3234 
3235   // Verify that klass is present in ClassLoaderData
3236   guarantee(class_loader_data()->contains_klass(this),
3237             "this class isn't found in class loader data");
3238 
3239   // Verify vtables
3240   if (is_linked()) {
3241     // $$$ This used to be done only for m/s collections.  Doing it
3242     // always seemed a valid generalization.  (DLD -- 6/00)
3243     vtable().verify(st);
3244   }
3245 
3246   // Verify first subklass
3247   if (subklass() != NULL) {
3248     guarantee(subklass()->is_klass(), "should be klass");
3249   }
3250 
3251   // Verify siblings
3252   Klass* super = this->super();
3253   Klass* sib = next_sibling();
3254   if (sib != NULL) {
3255     if (sib == this) {
3256       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3257     }
3258 
3259     guarantee(sib->is_klass(), "should be klass");
3260     guarantee(sib->super() == super, "siblings should have same superklass");
3261   }
3262 
3263   // Verify implementor fields
3264   Klass* im = implementor();
3265   if (im != NULL) {
3266     guarantee(is_interface(), "only interfaces should have implementor set");
3267     guarantee(im->is_klass(), "should be klass");
3268     guarantee(!im->is_interface() || im == this,
3269       "implementors cannot be interfaces");
3270   }
3271 
3272   // Verify local interfaces
3273   if (local_interfaces()) {
3274     Array<Klass*>* local_interfaces = this->local_interfaces();
3275     for (int j = 0; j < local_interfaces->length(); j++) {
3276       Klass* e = local_interfaces->at(j);
3277       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3278     }
3279   }
3280 
3281   // Verify transitive interfaces
3282   if (transitive_interfaces() != NULL) {
3283     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3284     for (int j = 0; j < transitive_interfaces->length(); j++) {
3285       Klass* e = transitive_interfaces->at(j);
3286       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3287     }
3288   }
3289 
3290   // Verify methods
3291   if (methods() != NULL) {
3292     Array<Method*>* methods = this->methods();
3293     for (int j = 0; j < methods->length(); j++) {
3294       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3295     }
3296     for (int j = 0; j < methods->length() - 1; j++) {
3297       Method* m1 = methods->at(j);
3298       Method* m2 = methods->at(j + 1);
3299       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3300     }
3301   }
3302 
3303   // Verify method ordering
3304   if (method_ordering() != NULL) {
3305     Array<int>* method_ordering = this->method_ordering();
3306     int length = method_ordering->length();
3307     if (JvmtiExport::can_maintain_original_method_order() ||
3308         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3309       guarantee(length == methods()->length(), "invalid method ordering length");
3310       jlong sum = 0;
3311       for (int j = 0; j < length; j++) {
3312         int original_index = method_ordering->at(j);
3313         guarantee(original_index >= 0, "invalid method ordering index");
3314         guarantee(original_index < length, "invalid method ordering index");
3315         sum += original_index;
3316       }
3317       // Verify sum of indices 0,1,...,length-1
3318       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3319     } else {
3320       guarantee(length == 0, "invalid method ordering length");
3321     }
3322   }
3323 
3324   // Verify default methods
3325   if (default_methods() != NULL) {
3326     Array<Method*>* methods = this->default_methods();
3327     for (int j = 0; j < methods->length(); j++) {
3328       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3329     }
3330     for (int j = 0; j < methods->length() - 1; j++) {
3331       Method* m1 = methods->at(j);
3332       Method* m2 = methods->at(j + 1);
3333       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3334     }
3335   }
3336 
3337   // Verify JNI static field identifiers
3338   if (jni_ids() != NULL) {
3339     jni_ids()->verify(this);
3340   }
3341 
3342   // Verify other fields
3343   if (array_klasses() != NULL) {
3344     guarantee(array_klasses()->is_klass(), "should be klass");
3345   }
3346   if (constants() != NULL) {
3347     guarantee(constants()->is_constantPool(), "should be constant pool");
3348   }
3349   const Klass* host = host_klass();
3350   if (host != NULL) {
3351     guarantee(host->is_klass(), "should be klass");
3352   }
3353 }
3354 
3355 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3356   Klass::oop_verify_on(obj, st);
3357   VerifyFieldClosure blk;
3358   obj->oop_iterate_no_header(&blk);
3359 }
3360 
3361 
3362 // JNIid class for jfieldIDs only
3363 // Note to reviewers:
3364 // These JNI functions are just moved over to column 1 and not changed
3365 // in the compressed oops workspace.
3366 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3367   _holder = holder;
3368   _offset = offset;
3369   _next = next;
3370   debug_only(_is_static_field_id = false;)
3371 }
3372 
3373 
3374 JNIid* JNIid::find(int offset) {
3375   JNIid* current = this;
3376   while (current != NULL) {
3377     if (current->offset() == offset) return current;
3378     current = current->next();
3379   }
3380   return NULL;
3381 }
3382 
3383 void JNIid::deallocate(JNIid* current) {
3384   while (current != NULL) {
3385     JNIid* next = current->next();
3386     delete current;
3387     current = next;
3388   }
3389 }
3390 
3391 
3392 void JNIid::verify(Klass* holder) {
3393   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3394   int end_field_offset;
3395   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3396 
3397   JNIid* current = this;
3398   while (current != NULL) {
3399     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3400 #ifdef ASSERT
3401     int o = current->offset();
3402     if (current->is_static_field_id()) {
3403       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3404     }
3405 #endif
3406     current = current->next();
3407   }
3408 }
3409 
3410 oop InstanceKlass::klass_holder_phantom() {
3411   oop* addr;
3412   if (is_anonymous()) {
3413     addr = _java_mirror.ptr_raw();
3414   } else {
3415     addr = &class_loader_data()->_class_loader;
3416   }
3417   return RootAccess<IN_CONCURRENT_ROOT | ON_PHANTOM_OOP_REF>::oop_load(addr);
3418 }
3419 
3420 #ifdef ASSERT
3421 void InstanceKlass::set_init_state(ClassState state) {
3422   bool good_state = is_shared() ? (_init_state <= state)
3423                                                : (_init_state < state);
3424   assert(good_state || state == allocated, "illegal state transition");
3425   _init_state = (u1)state;
3426 }
3427 #endif
3428 
3429 #if INCLUDE_JVMTI
3430 
3431 // RedefineClasses() support for previous versions
3432 
3433 // Globally, there is at least one previous version of a class to walk
3434 // during class unloading, which is saved because old methods in the class
3435 // are still running.   Otherwise the previous version list is cleaned up.
3436 bool InstanceKlass::_has_previous_versions = false;
3437 
3438 // Returns true if there are previous versions of a class for class
3439 // unloading only. Also resets the flag to false. purge_previous_version
3440 // will set the flag to true if there are any left, i.e., if there's any
3441 // work to do for next time. This is to avoid the expensive code cache
3442 // walk in CLDG::do_unloading().
3443 bool InstanceKlass::has_previous_versions_and_reset() {
3444   bool ret = _has_previous_versions;
3445   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3446      ret ? "true" : "false");
3447   _has_previous_versions = false;
3448   return ret;
3449 }
3450 
3451 // Purge previous versions before adding new previous versions of the class and
3452 // during class unloading.
3453 void InstanceKlass::purge_previous_version_list() {
3454   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3455   assert(has_been_redefined(), "Should only be called for main class");
3456 
3457   // Quick exit.
3458   if (previous_versions() == NULL) {
3459     return;
3460   }
3461 
3462   // This klass has previous versions so see what we can cleanup
3463   // while it is safe to do so.
3464 
3465   int deleted_count = 0;    // leave debugging breadcrumbs
3466   int live_count = 0;
3467   ClassLoaderData* loader_data = class_loader_data();
3468   assert(loader_data != NULL, "should never be null");
3469 
3470   ResourceMark rm;
3471   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3472 
3473   // previous versions are linked together through the InstanceKlass
3474   InstanceKlass* pv_node = previous_versions();
3475   InstanceKlass* last = this;
3476   int version = 0;
3477 
3478   // check the previous versions list
3479   for (; pv_node != NULL; ) {
3480 
3481     ConstantPool* pvcp = pv_node->constants();
3482     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3483 
3484     if (!pvcp->on_stack()) {
3485       // If the constant pool isn't on stack, none of the methods
3486       // are executing.  Unlink this previous_version.
3487       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3488       // so will be deallocated during the next phase of class unloading.
3489       log_trace(redefine, class, iklass, purge)
3490         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3491       // For debugging purposes.
3492       pv_node->set_is_scratch_class();
3493       // Unlink from previous version list.
3494       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3495       InstanceKlass* next = pv_node->previous_versions();
3496       pv_node->link_previous_versions(NULL);   // point next to NULL
3497       last->link_previous_versions(next);
3498       // Add to the deallocate list after unlinking
3499       loader_data->add_to_deallocate_list(pv_node);
3500       pv_node = next;
3501       deleted_count++;
3502       version++;
3503       continue;
3504     } else {
3505       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3506       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3507       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3508       live_count++;
3509       // found a previous version for next time we do class unloading
3510       _has_previous_versions = true;
3511     }
3512 
3513     // At least one method is live in this previous version.
3514     // Reset dead EMCP methods not to get breakpoints.
3515     // All methods are deallocated when all of the methods for this class are no
3516     // longer running.
3517     Array<Method*>* method_refs = pv_node->methods();
3518     if (method_refs != NULL) {
3519       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3520       for (int j = 0; j < method_refs->length(); j++) {
3521         Method* method = method_refs->at(j);
3522 
3523         if (!method->on_stack()) {
3524           // no breakpoints for non-running methods
3525           if (method->is_running_emcp()) {
3526             method->set_running_emcp(false);
3527           }
3528         } else {
3529           assert (method->is_obsolete() || method->is_running_emcp(),
3530                   "emcp method cannot run after emcp bit is cleared");
3531           log_trace(redefine, class, iklass, purge)
3532             ("purge: %s(%s): prev method @%d in version @%d is alive",
3533              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3534         }
3535       }
3536     }
3537     // next previous version
3538     last = pv_node;
3539     pv_node = pv_node->previous_versions();
3540     version++;
3541   }
3542   log_trace(redefine, class, iklass, purge)
3543     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3544 }
3545 
3546 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3547                                                 int emcp_method_count) {
3548   int obsolete_method_count = old_methods->length() - emcp_method_count;
3549 
3550   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3551       _previous_versions != NULL) {
3552     // We have a mix of obsolete and EMCP methods so we have to
3553     // clear out any matching EMCP method entries the hard way.
3554     int local_count = 0;
3555     for (int i = 0; i < old_methods->length(); i++) {
3556       Method* old_method = old_methods->at(i);
3557       if (old_method->is_obsolete()) {
3558         // only obsolete methods are interesting
3559         Symbol* m_name = old_method->name();
3560         Symbol* m_signature = old_method->signature();
3561 
3562         // previous versions are linked together through the InstanceKlass
3563         int j = 0;
3564         for (InstanceKlass* prev_version = _previous_versions;
3565              prev_version != NULL;
3566              prev_version = prev_version->previous_versions(), j++) {
3567 
3568           Array<Method*>* method_refs = prev_version->methods();
3569           for (int k = 0; k < method_refs->length(); k++) {
3570             Method* method = method_refs->at(k);
3571 
3572             if (!method->is_obsolete() &&
3573                 method->name() == m_name &&
3574                 method->signature() == m_signature) {
3575               // The current RedefineClasses() call has made all EMCP
3576               // versions of this method obsolete so mark it as obsolete
3577               log_trace(redefine, class, iklass, add)
3578                 ("%s(%s): flush obsolete method @%d in version @%d",
3579                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3580 
3581               method->set_is_obsolete();
3582               break;
3583             }
3584           }
3585 
3586           // The previous loop may not find a matching EMCP method, but
3587           // that doesn't mean that we can optimize and not go any
3588           // further back in the PreviousVersion generations. The EMCP
3589           // method for this generation could have already been made obsolete,
3590           // but there still may be an older EMCP method that has not
3591           // been made obsolete.
3592         }
3593 
3594         if (++local_count >= obsolete_method_count) {
3595           // no more obsolete methods so bail out now
3596           break;
3597         }
3598       }
3599     }
3600   }
3601 }
3602 
3603 // Save the scratch_class as the previous version if any of the methods are running.
3604 // The previous_versions are used to set breakpoints in EMCP methods and they are
3605 // also used to clean MethodData links to redefined methods that are no longer running.
3606 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3607                                          int emcp_method_count) {
3608   assert(Thread::current()->is_VM_thread(),
3609          "only VMThread can add previous versions");
3610 
3611   ResourceMark rm;
3612   log_trace(redefine, class, iklass, add)
3613     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3614 
3615   // Clean out old previous versions for this class
3616   purge_previous_version_list();
3617 
3618   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3619   // a previous redefinition may be made obsolete by this redefinition.
3620   Array<Method*>* old_methods = scratch_class->methods();
3621   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3622 
3623   // If the constant pool for this previous version of the class
3624   // is not marked as being on the stack, then none of the methods
3625   // in this previous version of the class are on the stack so
3626   // we don't need to add this as a previous version.
3627   ConstantPool* cp_ref = scratch_class->constants();
3628   if (!cp_ref->on_stack()) {
3629     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3630     // For debugging purposes.
3631     scratch_class->set_is_scratch_class();
3632     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3633     return;
3634   }
3635 
3636   if (emcp_method_count != 0) {
3637     // At least one method is still running, check for EMCP methods
3638     for (int i = 0; i < old_methods->length(); i++) {
3639       Method* old_method = old_methods->at(i);
3640       if (!old_method->is_obsolete() && old_method->on_stack()) {
3641         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3642         // we can add breakpoints for it.
3643 
3644         // We set the method->on_stack bit during safepoints for class redefinition
3645         // and use this bit to set the is_running_emcp bit.
3646         // After the safepoint, the on_stack bit is cleared and the running emcp
3647         // method may exit.   If so, we would set a breakpoint in a method that
3648         // is never reached, but this won't be noticeable to the programmer.
3649         old_method->set_running_emcp(true);
3650         log_trace(redefine, class, iklass, add)
3651           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3652       } else if (!old_method->is_obsolete()) {
3653         log_trace(redefine, class, iklass, add)
3654           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3655       }
3656     }
3657   }
3658 
3659   // Add previous version if any methods are still running.
3660   // Set has_previous_version flag for processing during class unloading.
3661   _has_previous_versions = true;
3662   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3663   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3664   scratch_class->link_previous_versions(previous_versions());
3665   link_previous_versions(scratch_class);
3666 } // end add_previous_version()
3667 
3668 #endif // INCLUDE_JVMTI
3669 
3670 Method* InstanceKlass::method_with_idnum(int idnum) {
3671   Method* m = NULL;
3672   if (idnum < methods()->length()) {
3673     m = methods()->at(idnum);
3674   }
3675   if (m == NULL || m->method_idnum() != idnum) {
3676     for (int index = 0; index < methods()->length(); ++index) {
3677       m = methods()->at(index);
3678       if (m->method_idnum() == idnum) {
3679         return m;
3680       }
3681     }
3682     // None found, return null for the caller to handle.
3683     return NULL;
3684   }
3685   return m;
3686 }
3687 
3688 
3689 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3690   if (idnum >= methods()->length()) {
3691     return NULL;
3692   }
3693   Method* m = methods()->at(idnum);
3694   if (m != NULL && m->orig_method_idnum() == idnum) {
3695     return m;
3696   }
3697   // Obsolete method idnum does not match the original idnum
3698   for (int index = 0; index < methods()->length(); ++index) {
3699     m = methods()->at(index);
3700     if (m->orig_method_idnum() == idnum) {
3701       return m;
3702     }
3703   }
3704   // None found, return null for the caller to handle.
3705   return NULL;
3706 }
3707 
3708 
3709 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3710   InstanceKlass* holder = get_klass_version(version);
3711   if (holder == NULL) {
3712     return NULL; // The version of klass is gone, no method is found
3713   }
3714   Method* method = holder->method_with_orig_idnum(idnum);
3715   return method;
3716 }
3717 
3718 #if INCLUDE_JVMTI
3719 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3720   if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3721     // Ignore the archived class stream data
3722     return NULL;
3723   } else {
3724     return _cached_class_file;
3725   }
3726 }
3727 
3728 jint InstanceKlass::get_cached_class_file_len() {
3729   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3730 }
3731 
3732 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3733   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3734 }
3735 
3736 #if INCLUDE_CDS
3737 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3738   if (DumpSharedSpaces) {
3739     return _cached_class_file;
3740   } else {
3741     assert(this->is_shared(), "class should be shared");
3742     if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3743       return _cached_class_file;
3744     } else {
3745       return NULL;
3746     }
3747   }
3748 }
3749 #endif
3750 #endif
--- EOF ---