1 /*
   2  * Copyright (c) 1997, 2024, 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 #ifndef SHARE_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/referenceType.hpp"
  30 #include "oops/annotations.hpp"
  31 #include "oops/constMethod.hpp"
  32 #include "oops/fieldInfo.hpp"
  33 #include "oops/instanceKlassFlags.hpp"
  34 #include "oops/instanceOop.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/javaThread.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/align.hpp"
  39 #include "utilities/growableArray.hpp"
  40 #include "utilities/macros.hpp"
  41 #if INCLUDE_JFR
  42 #include "jfr/support/jfrKlassExtension.hpp"
  43 #endif
  44 
  45 class ConstantPool;
  46 class DeoptimizationScope;
  47 class klassItable;
  48 class Monitor;
  49 class RecordComponent;
  50 
  51 // An InstanceKlass is the VM level representation of a Java class.
  52 // It contains all information needed for at class at execution runtime.
  53 
  54 //  InstanceKlass embedded field layout (after declared fields):
  55 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  56 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  57 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  58 //      indicating where oops are located in instances of this klass.
  59 //    [EMBEDDED implementor of the interface] only exist for interface
  60 
  61 
  62 // forward declaration for class -- see below for definition
  63 #if INCLUDE_JVMTI
  64 class BreakpointInfo;
  65 #endif
  66 class ClassFileParser;
  67 class ClassFileStream;
  68 class KlassDepChange;
  69 class DependencyContext;
  70 class fieldDescriptor;
  71 class jniIdMapBase;
  72 class JNIid;
  73 class JvmtiCachedClassFieldMap;
  74 class nmethodBucket;
  75 class OopMapCache;
  76 class InterpreterOopMap;
  77 class PackageEntry;
  78 class ModuleEntry;
  79 
  80 // This is used in iterators below.
  81 class FieldClosure: public StackObj {
  82 public:
  83   virtual void do_field(fieldDescriptor* fd) = 0;
  84 };
  85 
  86 // Print fields.
  87 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  88 class FieldPrinter: public FieldClosure {
  89    oop _obj;
  90    outputStream* _st;
  91  public:
  92    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  93    void do_field(fieldDescriptor* fd);
  94 };
  95 
  96 // Describes where oops are located in instances of this klass.
  97 class OopMapBlock {
  98  public:
  99   // Byte offset of the first oop mapped by this block.
 100   int offset() const          { return _offset; }
 101   void set_offset(int offset) { _offset = offset; }
 102 
 103   // Number of oops in this block.
 104   uint count() const         { return _count; }
 105   void set_count(uint count) { _count = count; }
 106 
 107   void increment_count(int diff) { _count += diff; }
 108 
 109   int offset_span() const { return _count * heapOopSize; }
 110 
 111   int end_offset() const {
 112     return offset() + offset_span();
 113   }
 114 
 115   bool is_contiguous(int another_offset) const {
 116     return another_offset == end_offset();
 117   }
 118 
 119   // sizeof(OopMapBlock) in words.
 120   static int size_in_words() {
 121     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 122       LogBytesPerWord;
 123   }
 124 
 125   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 126     return a->offset() - b->offset();
 127   }
 128 
 129  private:
 130   int  _offset;
 131   uint _count;
 132 };
 133 
 134 struct JvmtiCachedClassFileData;
 135 
 136 class InstanceKlass: public Klass {
 137   friend class VMStructs;
 138   friend class JVMCIVMStructs;
 139   friend class ClassFileParser;
 140   friend class CompileReplay;
 141 
 142  public:
 143   static const KlassKind Kind = InstanceKlassKind;
 144 
 145  protected:
 146   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 147 
 148   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, bool use_class_space, TRAPS) throw();
 149 
 150  public:
 151   InstanceKlass();
 152 
 153   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 154   // of the class loading & initialization procedure, and the use of the states.
 155   enum ClassState : u1 {
 156     allocated,                          // allocated (but not yet linked)
 157     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 158     linked,                             // successfully linked/verified (but not initialized yet)
 159     being_initialized,                  // currently running class initializer
 160     fully_initialized,                  // initialized (successful final state)
 161     initialization_error                // error happened during initialization
 162   };
 163 
 164  private:
 165   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 166 
 167  protected:
 168   // If you add a new field that points to any metaspace object, you
 169   // must add this field to InstanceKlass::metaspace_pointers_do().
 170 
 171   // Annotations for this class
 172   Annotations*    _annotations;
 173   // Package this class is defined in
 174   PackageEntry*   _package_entry;
 175   // Array classes holding elements of this class.
 176   ObjArrayKlass* volatile _array_klasses;
 177   // Constant pool for this class.
 178   ConstantPool* _constants;
 179   // The InnerClasses attribute and EnclosingMethod attribute. The
 180   // _inner_classes is an array of shorts. If the class has InnerClasses
 181   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 182   // [inner_class_info_index, outer_class_info_index,
 183   // inner_name_index, inner_class_access_flags] for the InnerClasses
 184   // attribute. If the EnclosingMethod attribute exists, it occupies the
 185   // last two shorts [class_index, method_index] of the array. If only
 186   // the InnerClasses attribute exists, the _inner_classes array length is
 187   // number_of_inner_classes * 4. If the class has both InnerClasses
 188   // and EnclosingMethod attributes the _inner_classes array length is
 189   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 190   Array<jushort>* _inner_classes;
 191 
 192   // The NestMembers attribute. An array of shorts, where each is a
 193   // class info index for the class that is a nest member. This data
 194   // has not been validated.
 195   Array<jushort>* _nest_members;
 196 
 197   // Resolved nest-host klass: either true nest-host or self if we are not
 198   // nested, or an error occurred resolving or validating the nominated
 199   // nest-host. Can also be set directly by JDK API's that establish nest
 200   // relationships.
 201   // By always being set it makes nest-member access checks simpler.
 202   InstanceKlass* _nest_host;
 203 
 204   // The PermittedSubclasses attribute. An array of shorts, where each is a
 205   // class info index for the class that is a permitted subclass.
 206   Array<jushort>* _permitted_subclasses;
 207 
 208   // The contents of the Record attribute.
 209   Array<RecordComponent*>* _record_components;
 210 
 211   // the source debug extension for this klass, null if not specified.
 212   // Specified as UTF-8 string without terminating zero byte in the classfile,
 213   // it is stored in the instanceklass as a null-terminated UTF-8 string
 214   const char*     _source_debug_extension;
 215 
 216   // Number of heapOopSize words used by non-static fields in this klass
 217   // (including inherited fields but after header_size()).
 218   int             _nonstatic_field_size;
 219   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 220   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 221   int             _itable_len;              // length of Java itable (in words)
 222 
 223   // The NestHost attribute. The class info index for the class
 224   // that is the nest-host of this class. This data has not been validated.
 225   u2              _nest_host_index;
 226   u2              _this_class_index;        // constant pool entry
 227   u2              _static_oop_field_count;  // number of static oop fields in this klass
 228 
 229   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 230 
 231   // Class states are defined as ClassState (see above).
 232   // Place the _init_state here to utilize the unused 2-byte after
 233   // _idnum_allocated_count.
 234   volatile ClassState _init_state;          // state of class
 235 
 236   u1              _reference_type;                // reference type
 237 
 238   // State is set either at parse time or while executing, atomically to not disturb other state
 239   InstanceKlassFlags _misc_flags;
 240 
 241   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 242 
 243   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 244   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 245   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 246   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 247   uint64_t        volatile _dep_context_last_cleaned;
 248   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 249 #if INCLUDE_JVMTI
 250   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 251   // Linked instanceKlasses of previous versions
 252   InstanceKlass* _previous_versions;
 253   // JVMTI fields can be moved to their own structure - see 6315920
 254   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 255   JvmtiCachedClassFileData* _cached_class_file;
 256 #endif
 257 
 258 #if INCLUDE_JVMTI
 259   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 260 #endif
 261 
 262   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 263   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 264 
 265   // Method array.
 266   Array<Method*>* _methods;
 267   // Default Method Array, concrete methods inherited from interfaces
 268   Array<Method*>* _default_methods;
 269   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 270   Array<InstanceKlass*>* _local_interfaces;
 271   // Interfaces (InstanceKlass*s) this class implements transitively.
 272   Array<InstanceKlass*>* _transitive_interfaces;
 273   // Int array containing the original order of method in the class file (for JVMTI).
 274   Array<int>*     _method_ordering;
 275   // Int array containing the vtable_indices for default_methods
 276   // offset matches _default_methods offset
 277   Array<int>*     _default_vtable_indices;
 278 
 279   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 280   Array<u1>*          _fieldinfo_stream;
 281   Array<FieldStatus>* _fields_status;
 282 
 283   // embedded Java vtable follows here
 284   // embedded Java itables follows here
 285   // embedded static fields follows here
 286   // embedded nonstatic oop-map blocks follows here
 287   // embedded implementor of this interface follows here
 288   //   The embedded implementor only exists if the current klass is an
 289   //   interface. The possible values of the implementor fall into following
 290   //   three cases:
 291   //     null: no implementor.
 292   //     A Klass* that's not itself: one implementor.
 293   //     Itself: more than one implementors.
 294   //
 295 
 296   friend class SystemDictionary;
 297 
 298   static bool _disable_method_binary_search;
 299 
 300   // Controls finalizer registration
 301   static bool _finalization_enabled;
 302 
 303  public:
 304 
 305   // Queries finalization state
 306   static bool is_finalization_enabled() { return _finalization_enabled; }
 307 
 308   // Sets finalization state
 309   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 310 
 311   // The three BUILTIN class loader types
 312   bool is_shared_boot_class() const { return _misc_flags.is_shared_boot_class(); }
 313   bool is_shared_platform_class() const { return _misc_flags.is_shared_platform_class(); }
 314   bool is_shared_app_class() const {  return _misc_flags.is_shared_app_class(); }
 315   // The UNREGISTERED class loader type
 316   bool is_shared_unregistered_class() const { return _misc_flags.is_shared_unregistered_class(); }
 317 
 318   // Check if the class can be shared in CDS
 319   bool is_shareable() const;
 320 
 321   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 322 
 323   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 324 
 325 #if INCLUDE_CDS
 326   void set_shared_class_loader_type(s2 loader_type) { _misc_flags.set_shared_class_loader_type(loader_type); }
 327   void assign_class_loader_type() { _misc_flags.assign_class_loader_type(_class_loader_data); }
 328 #endif
 329 
 330   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 331   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 332 
 333   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 334   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 335 
 336   // field sizes
 337   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 338   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 339 
 340   int static_field_size() const            { return _static_field_size; }
 341   void set_static_field_size(int size)     { _static_field_size = size; }
 342 
 343   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 344   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 345 
 346   // Java itable
 347   int  itable_length() const               { return _itable_len; }
 348   void set_itable_length(int len)          { _itable_len = len; }
 349 
 350   // array klasses
 351   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 352   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 353   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 354   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 355 
 356   // methods
 357   Array<Method*>* methods() const          { return _methods; }
 358   void set_methods(Array<Method*>* a)      { _methods = a; }
 359   Method* method_with_idnum(int idnum);
 360   Method* method_with_orig_idnum(int idnum);
 361   Method* method_with_orig_idnum(int idnum, int version);
 362 
 363   // method ordering
 364   Array<int>* method_ordering() const     { return _method_ordering; }
 365   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 366   void copy_method_ordering(const intArray* m, TRAPS);
 367 
 368   // default_methods
 369   Array<Method*>* default_methods() const  { return _default_methods; }
 370   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 371 
 372   // default method vtable_indices
 373   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 374   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 375   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 376 
 377   // interfaces
 378   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 379   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 380     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 381     _local_interfaces = a; }
 382 
 383   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 384   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 385     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 386     _transitive_interfaces = a;
 387   }
 388 
 389  private:
 390   friend class fieldDescriptor;
 391   FieldInfo field(int index) const;
 392 
 393  public:
 394   int     field_offset      (int index) const { return field(index).offset(); }
 395   int     field_access_flags(int index) const { return field(index).access_flags().as_int(); }
 396   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 397   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 398   inline Symbol* field_name        (int index) const;
 399   inline Symbol* field_signature   (int index) const;
 400 
 401   // Number of Java declared fields
 402   int java_fields_count() const;
 403   int total_fields_count() const;
 404 
 405   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 406   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 407 
 408   Array<FieldStatus>* fields_status() const {return _fields_status; }
 409   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 410 
 411   // inner classes
 412   Array<u2>* inner_classes() const       { return _inner_classes; }
 413   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 414 
 415   // nest members
 416   Array<u2>* nest_members() const     { return _nest_members; }
 417   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 418 
 419   // nest-host index
 420   jushort nest_host_index() const { return _nest_host_index; }
 421   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 422   // dynamic nest member support
 423   void set_nest_host(InstanceKlass* host);
 424 
 425   // record components
 426   Array<RecordComponent*>* record_components() const { return _record_components; }
 427   void set_record_components(Array<RecordComponent*>* record_components) {
 428     _record_components = record_components;
 429   }
 430   bool is_record() const;
 431 
 432   // permitted subclasses
 433   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 434   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 435 
 436 private:
 437   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 438   // nor does it resolve any CP entries or load any classes.
 439   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 440 
 441 public:
 442   // Call this only if you know that the nest host has been initialized.
 443   InstanceKlass* nest_host_not_null() {
 444     assert(_nest_host != nullptr, "must be");
 445     return _nest_host;
 446   }
 447   // Used to construct informative IllegalAccessError messages at a higher level,
 448   // if there was an issue resolving or validating the nest host.
 449   // Returns null if there was no error.
 450   const char* nest_host_error();
 451   // Returns nest-host class, resolving and validating it if needed.
 452   // Returns null if resolution is not possible from the calling context.
 453   InstanceKlass* nest_host(TRAPS);
 454   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 455   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 456 
 457   // Called to verify that k is a permitted subclass of this class
 458   bool has_as_permitted_subclass(const InstanceKlass* k) const;
 459 
 460   enum InnerClassAttributeOffset {
 461     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 462     inner_class_inner_class_info_offset = 0,
 463     inner_class_outer_class_info_offset = 1,
 464     inner_class_inner_name_offset = 2,
 465     inner_class_access_flags_offset = 3,
 466     inner_class_next_offset = 4
 467   };
 468 
 469   enum EnclosingMethodAttributeOffset {
 470     enclosing_method_class_index_offset = 0,
 471     enclosing_method_method_index_offset = 1,
 472     enclosing_method_attribute_size = 2
 473   };
 474 
 475   // package
 476   PackageEntry* package() const     { return _package_entry; }
 477   ModuleEntry* module() const;
 478   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 479   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 480   // If the package for the InstanceKlass is in the boot loader's package entry
 481   // table then sets the classpath_index field so that
 482   // get_system_package() will know to return a non-null value for the
 483   // package's location.  And, so that the package will be added to the list of
 484   // packages returned by get_system_packages().
 485   // For packages whose classes are loaded from the boot loader class path, the
 486   // classpath_index indicates which entry on the boot loader class path.
 487   void set_classpath_index(s2 path_index);
 488   bool is_same_class_package(const Klass* class2) const;
 489   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 490 
 491   // find an enclosing class
 492   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 493 
 494   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 495   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 496 
 497  private:
 498   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 499   static void check_prohibited_package(Symbol* class_name,
 500                                        ClassLoaderData* loader_data,
 501                                        TRAPS);
 502 
 503   JavaThread* init_thread()  { return Atomic::load(&_init_thread); }
 504   const char* init_thread_name() {
 505     return init_thread()->name_raw();
 506   }
 507 
 508  public:
 509   // initialization state
 510   bool is_loaded() const                   { return init_state() >= loaded; }
 511   bool is_linked() const                   { return init_state() >= linked; }
 512   bool is_initialized() const              { return init_state() == fully_initialized; }
 513   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 514   bool is_being_initialized() const        { return init_state() == being_initialized; }
 515   bool is_in_error_state() const           { return init_state() == initialization_error; }
 516   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 517   ClassState  init_state() const           { return Atomic::load_acquire(&_init_state); }
 518   const char* init_state_name() const;
 519   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 520 
 521   // is this a sealed class
 522   bool is_sealed() const;
 523 
 524   // defineClass specified verification
 525   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 526   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 527 
 528   // marking
 529   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 530   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 531 
 532   // initialization (virtuals from Klass)
 533   bool should_be_initialized() const;  // means that initialize should be called
 534   void initialize(TRAPS);
 535   void link_class(TRAPS);
 536   bool link_class_or_fail(TRAPS); // returns false on failure
 537   void rewrite_class(TRAPS);
 538   void link_methods(TRAPS);
 539   Method* class_initializer() const;
 540 
 541   // reference type
 542   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 543 
 544   // this class cp index
 545   u2 this_class_index() const             { return _this_class_index; }
 546   void set_this_class_index(u2 index)     { _this_class_index = index; }
 547 
 548   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 549 
 550   // find local field, returns true if found
 551   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 552   // find field in direct superinterfaces, returns the interface in which the field is defined
 553   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 554   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 555   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 556   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 557   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 558 
 559   // find a non-static or static field given its offset within the class.
 560   bool contains_field_offset(int offset);
 561 
 562   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 563   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 564 
 565  private:
 566   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 567 
 568  public:
 569   static void disable_method_binary_search() {
 570     _disable_method_binary_search = true;
 571   }
 572 
 573   // find a local method (returns null if not found)
 574   Method* find_method(const Symbol* name, const Symbol* signature) const;
 575   static Method* find_method(const Array<Method*>* methods,
 576                              const Symbol* name,
 577                              const Symbol* signature);
 578 
 579   // find a local method, but skip static methods
 580   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 581                                PrivateLookupMode private_mode) const;
 582   static Method* find_instance_method(const Array<Method*>* methods,
 583                                       const Symbol* name,
 584                                       const Symbol* signature,
 585                                       PrivateLookupMode private_mode);
 586 
 587   // find a local method (returns null if not found)
 588   Method* find_local_method(const Symbol* name,
 589                             const Symbol* signature,
 590                             OverpassLookupMode overpass_mode,
 591                             StaticLookupMode static_mode,
 592                             PrivateLookupMode private_mode) const;
 593 
 594   // find a local method from given methods array (returns null if not found)
 595   static Method* find_local_method(const Array<Method*>* methods,
 596                                    const Symbol* name,
 597                                    const Symbol* signature,
 598                                    OverpassLookupMode overpass_mode,
 599                                    StaticLookupMode static_mode,
 600                                    PrivateLookupMode private_mode);
 601 
 602   // find a local method index in methods or default_methods (returns -1 if not found)
 603   static int find_method_index(const Array<Method*>* methods,
 604                                const Symbol* name,
 605                                const Symbol* signature,
 606                                OverpassLookupMode overpass_mode,
 607                                StaticLookupMode static_mode,
 608                                PrivateLookupMode private_mode);
 609 
 610   // lookup operation (returns null if not found)
 611   Method* uncached_lookup_method(const Symbol* name,
 612                                  const Symbol* signature,
 613                                  OverpassLookupMode overpass_mode,
 614                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 615 
 616   // lookup a method in all the interfaces that this class implements
 617   // (returns null if not found)
 618   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 619 
 620   // lookup a method in local defaults then in all interfaces
 621   // (returns null if not found)
 622   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 623 
 624   // Find method indices by name.  If a method with the specified name is
 625   // found the index to the first method is returned, and 'end' is filled in
 626   // with the index of first non-name-matching method.  If no method is found
 627   // -1 is returned.
 628   int find_method_by_name(const Symbol* name, int* end) const;
 629   static int find_method_by_name(const Array<Method*>* methods,
 630                                  const Symbol* name, int* end);
 631 
 632   // constant pool
 633   ConstantPool* constants() const        { return _constants; }
 634   void set_constants(ConstantPool* c)    { _constants = c; }
 635 
 636   // protection domain
 637   oop protection_domain() const;
 638 
 639   // signers
 640   objArrayOop signers() const;
 641 
 642   bool is_contended() const                { return _misc_flags.is_contended(); }
 643   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 644 
 645   // source file name
 646   Symbol* source_file_name() const;
 647   u2 source_file_name_index() const;
 648   void set_source_file_name_index(u2 sourcefile_index);
 649 
 650   // minor and major version numbers of class file
 651   u2 minor_version() const;
 652   void set_minor_version(u2 minor_version);
 653   u2 major_version() const;
 654   void set_major_version(u2 major_version);
 655 
 656   // source debug extension
 657   const char* source_debug_extension() const { return _source_debug_extension; }
 658   void set_source_debug_extension(const char* array, int length);
 659 
 660   // nonstatic oop-map blocks
 661   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 662     return oop_map_count * OopMapBlock::size_in_words();
 663   }
 664   unsigned int nonstatic_oop_map_count() const {
 665     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 666   }
 667   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 668   void set_nonstatic_oop_map_size(int words) {
 669     _nonstatic_oop_map_size = words;
 670   }
 671 
 672   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 673   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 674 
 675 #if INCLUDE_JVMTI
 676   // Redefinition locking.  Class can only be redefined by one thread at a time.
 677   // The flag is in access_flags so that it can be set and reset using atomic
 678   // operations, and not be reset by other misc_flag settings.
 679   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 680   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 681 
 682   // RedefineClasses() support for previous versions:
 683   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 684   void purge_previous_version_list();
 685 
 686   InstanceKlass* previous_versions() const { return _previous_versions; }
 687 #else
 688   InstanceKlass* previous_versions() const { return nullptr; }
 689 #endif
 690 
 691   InstanceKlass* get_klass_version(int version);
 692 
 693   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 694   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 695 
 696   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 697   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 698 
 699   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 700   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 701   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 702 
 703 public:
 704 #if INCLUDE_JVMTI
 705 
 706   void init_previous_versions() {
 707     _previous_versions = nullptr;
 708   }
 709 
 710  private:
 711   static bool  _should_clean_previous_versions;
 712  public:
 713   static void purge_previous_versions(InstanceKlass* ik) {
 714     if (ik->has_been_redefined()) {
 715       ik->purge_previous_version_list();
 716     }
 717   }
 718 
 719   static bool should_clean_previous_versions_and_reset();
 720   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 721 
 722   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 723   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 724     _cached_class_file = data;
 725   }
 726   JvmtiCachedClassFileData * get_cached_class_file();
 727   jint get_cached_class_file_len();
 728   unsigned char * get_cached_class_file_bytes();
 729 
 730   // JVMTI: Support for caching of field indices, types, and offsets
 731   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 732     _jvmti_cached_class_field_map = descriptor;
 733   }
 734   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 735     return _jvmti_cached_class_field_map;
 736   }
 737 #else // INCLUDE_JVMTI
 738 
 739   static void purge_previous_versions(InstanceKlass* ik) { return; };
 740   static bool should_clean_previous_versions_and_reset() { return false; }
 741 
 742   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 743     assert(data == nullptr, "unexpected call with JVMTI disabled");
 744   }
 745   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 746 
 747 #endif // INCLUDE_JVMTI
 748 
 749   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 750   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 751 
 752   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 753   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 754 
 755   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 756   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 757   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 758   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 759 
 760   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 761   inline u2 next_method_idnum();
 762   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 763 
 764   // generics support
 765   Symbol* generic_signature() const;
 766   u2 generic_signature_index() const;
 767   void set_generic_signature_index(u2 sig_index);
 768 
 769   u2 enclosing_method_data(int offset) const;
 770   u2 enclosing_method_class_index() const {
 771     return enclosing_method_data(enclosing_method_class_index_offset);
 772   }
 773   u2 enclosing_method_method_index() {
 774     return enclosing_method_data(enclosing_method_method_index_offset);
 775   }
 776   void set_enclosing_method_indices(u2 class_index,
 777                                     u2 method_index);
 778 
 779   // jmethodID support
 780   jmethodID get_jmethod_id(const methodHandle& method_h);
 781   void ensure_space_for_methodids(int start_offset = 0);
 782   jmethodID jmethod_id_or_null(Method* method);
 783   void update_methods_jmethod_cache();
 784 
 785   // annotations support
 786   Annotations* annotations() const          { return _annotations; }
 787   void set_annotations(Annotations* anno)   { _annotations = anno; }
 788 
 789   AnnotationArray* class_annotations() const {
 790     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 791   }
 792   Array<AnnotationArray*>* fields_annotations() const {
 793     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 794   }
 795   AnnotationArray* class_type_annotations() const {
 796     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 797   }
 798   Array<AnnotationArray*>* fields_type_annotations() const {
 799     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 800   }
 801   // allocation
 802   instanceOop allocate_instance(TRAPS);
 803   static instanceOop allocate_instance(oop cls, TRAPS);
 804 
 805   // additional member function to return a handle
 806   instanceHandle allocate_instance_handle(TRAPS);
 807 
 808   objArrayOop allocate_objArray(int n, int length, TRAPS);
 809   // Helper function
 810   static instanceOop register_finalizer(instanceOop i, TRAPS);
 811 
 812   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 813   // if not, throw either an Error or an Exception.
 814   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 815 
 816   // initialization
 817   void call_class_initializer(TRAPS);
 818   void set_initialization_state_and_notify(ClassState state, TRAPS);
 819 
 820   // OopMapCache support
 821   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 822   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 823   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 824 
 825   // JNI identifier support (for static fields - for jni performance)
 826   JNIid* jni_ids()                               { return _jni_ids; }
 827   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 828   JNIid* jni_id_for(int offset);
 829 
 830  public:
 831   // maintenance of deoptimization dependencies
 832   inline DependencyContext dependencies();
 833   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 834   void add_dependent_nmethod(nmethod* nm);
 835   void clean_dependency_context();
 836   // Setup link to hierarchy and deoptimize
 837   void add_to_hierarchy(JavaThread* current);
 838 
 839   // On-stack replacement support
 840   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 841   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 842   void add_osr_nmethod(nmethod* n);
 843   bool remove_osr_nmethod(nmethod* n);
 844   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 845   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 846 
 847 #if INCLUDE_JVMTI
 848   // Breakpoint support (see methods on Method* for details)
 849   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 850   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 851 #endif
 852 
 853   // support for stub routines
 854   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 855   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 856   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 857 
 858   // subclass/subinterface checks
 859   bool implements_interface(Klass* k) const;
 860   bool is_same_or_direct_interface(Klass* k) const;
 861 
 862 #ifdef ASSERT
 863   // check whether this class or one of its superclasses was redefined
 864   bool has_redefined_this_or_super() const;
 865 #endif
 866 
 867   // Access to the implementor of an interface.
 868   InstanceKlass* implementor() const;
 869   void set_implementor(InstanceKlass* ik);
 870   int  nof_implementors() const;
 871   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 872   void init_implementor();           // initialize
 873 
 874  private:
 875   // link this class into the implementors list of every interface it implements
 876   void process_interfaces();
 877 
 878  public:
 879   // virtual operations from Klass
 880   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 881                                                   Array<InstanceKlass*>* transitive_interfaces);
 882   bool can_be_primary_super_slow() const;
 883   size_t oop_size(oop obj)  const             { return size_helper(); }
 884   // slow because it's a virtual call and used for verifying the layout_helper.
 885   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 886   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 887 
 888   // Iterators
 889   void do_local_static_fields(FieldClosure* cl);
 890   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 891   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 892   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 893 
 894   void methods_do(void f(Method* method));
 895 
 896   static InstanceKlass* cast(Klass* k) {
 897     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 898   }
 899 
 900   static const InstanceKlass* cast(const Klass* k) {
 901     assert(k != nullptr, "k should not be null");
 902     assert(k->is_instance_klass(), "cast to InstanceKlass");
 903     return static_cast<const InstanceKlass*>(k);
 904   }
 905 
 906   virtual InstanceKlass* java_super() const {
 907     return (super() == nullptr) ? nullptr : cast(super());
 908   }
 909 
 910   // Sizing (in words)
 911   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
 912 
 913   static int size(int vtable_length, int itable_length,
 914                   int nonstatic_oop_map_size,
 915                   bool is_interface) {
 916     return align_metadata_size(header_size() +
 917            vtable_length +
 918            itable_length +
 919            nonstatic_oop_map_size +
 920            (is_interface ? (int)sizeof(Klass*)/wordSize : 0));
 921   }
 922 
 923   int size() const                    { return size(vtable_length(),
 924                                                itable_length(),
 925                                                nonstatic_oop_map_size(),
 926                                                is_interface());
 927   }
 928 
 929 
 930   inline intptr_t* start_of_itable() const;
 931   inline intptr_t* end_of_itable() const;
 932   inline oop static_field_base_raw();
 933 
 934   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
 935   inline Klass** end_of_nonstatic_oop_maps() const;
 936 
 937   inline InstanceKlass* volatile* adr_implementor() const;
 938 
 939   // Use this to return the size of an instance in heap words:
 940   int size_helper() const {
 941     return layout_helper_to_size_helper(layout_helper());
 942   }
 943 
 944   // This bit is initialized in classFileParser.cpp.
 945   // It is false under any of the following conditions:
 946   //  - the class is abstract (including any interface)
 947   //  - the class size is larger than FastAllocateSizeLimit
 948   //  - the class is java/lang/Class, which cannot be allocated directly
 949   bool can_be_fastpath_allocated() const {
 950     return !layout_helper_needs_slow_path(layout_helper());
 951   }
 952 
 953   // Java itable
 954   klassItable itable() const;        // return klassItable wrapper
 955   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
 956   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
 957   int vtable_index_of_interface_method(Method* method);
 958 
 959 #if INCLUDE_JVMTI
 960   void adjust_default_methods(bool* trace_name_printed);
 961 #endif // INCLUDE_JVMTI
 962 
 963   void clean_weak_instanceklass_links();
 964  private:
 965   void clean_implementors_list();
 966   void clean_method_data();
 967 
 968  public:
 969   // Explicit metaspace deallocation of fields
 970   // For RedefineClasses and class file parsing errors, we need to deallocate
 971   // instanceKlasses and the metadata they point to.
 972   void deallocate_contents(ClassLoaderData* loader_data);
 973   static void deallocate_methods(ClassLoaderData* loader_data,
 974                                  Array<Method*>* methods);
 975   void static deallocate_interfaces(ClassLoaderData* loader_data,
 976                                     const Klass* super_klass,
 977                                     Array<InstanceKlass*>* local_interfaces,
 978                                     Array<InstanceKlass*>* transitive_interfaces);
 979   void static deallocate_record_components(ClassLoaderData* loader_data,
 980                                            Array<RecordComponent*>* record_component);
 981 
 982   virtual bool on_stack() const;
 983 
 984   // callbacks for actions during class unloading
 985   static void unload_class(InstanceKlass* ik);
 986 
 987   virtual void release_C_heap_structures(bool release_sub_metadata = true);
 988 
 989   // Naming
 990   const char* signature_name() const;
 991 
 992   // Oop fields (and metadata) iterators
 993   //
 994   // The InstanceKlass iterators also visits the Object's klass.
 995 
 996   // Forward iteration
 997  public:
 998   // Iterate over all oop fields in the oop maps.
 999   template <typename T, class OopClosureType>
1000   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1001 
1002   // Iterate over all oop fields and metadata.
1003   template <typename T, class OopClosureType>
1004   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1005 
1006   // Iterate over all oop fields in one oop map.
1007   template <typename T, class OopClosureType>
1008   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1009 
1010 
1011   // Reverse iteration
1012   // Iterate over all oop fields and metadata.
1013   template <typename T, class OopClosureType>
1014   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1015 
1016  private:
1017   // Iterate over all oop fields in the oop maps.
1018   template <typename T, class OopClosureType>
1019   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1020 
1021   // Iterate over all oop fields in one oop map.
1022   template <typename T, class OopClosureType>
1023   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1024 
1025 
1026   // Bounded range iteration
1027  public:
1028   // Iterate over all oop fields in the oop maps.
1029   template <typename T, class OopClosureType>
1030   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1031 
1032   // Iterate over all oop fields and metadata.
1033   template <typename T, class OopClosureType>
1034   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1035 
1036  private:
1037   // Iterate over all oop fields in one oop map.
1038   template <typename T, class OopClosureType>
1039   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1040 
1041 
1042  public:
1043   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1044 
1045 private:
1046   // initialization state
1047   void set_init_state(ClassState state);
1048   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1049   void set_init_thread(JavaThread *thread)  {
1050     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1051            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1052     Atomic::store(&_init_thread, thread);
1053   }
1054 
1055   inline jmethodID* methods_jmethod_ids_acquire() const;
1056   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1057   // This nulls out jmethodIDs for all methods in 'klass'
1058   static void clear_jmethod_ids(InstanceKlass* klass);
1059   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1060 
1061 public:
1062   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1063   // Must be one per class and it has to be a VM internal object so java code
1064   // cannot lock it (like the mirror).
1065   // It has to be an object not a Mutex because it's held through java calls.
1066   oop init_lock() const;
1067 
1068   // Returns the array class for the n'th dimension
1069   virtual ArrayKlass* array_klass(int n, TRAPS);
1070   virtual ArrayKlass* array_klass_or_null(int n);
1071 
1072   // Returns the array class with this class as element type
1073   virtual ArrayKlass* array_klass(TRAPS);
1074   virtual ArrayKlass* array_klass_or_null();
1075 
1076   static void clean_initialization_error_table();
1077 private:
1078   void fence_and_clear_init_lock();
1079 
1080   bool link_class_impl                           (TRAPS);
1081   bool verify_code                               (TRAPS);
1082   void initialize_impl                           (TRAPS);
1083   void initialize_super_interfaces               (TRAPS);
1084 
1085   void add_initialization_error(JavaThread* current, Handle exception);
1086   oop get_initialization_error(JavaThread* current);
1087 
1088   // find a local method (returns null if not found)
1089   Method* find_method_impl(const Symbol* name,
1090                            const Symbol* signature,
1091                            OverpassLookupMode overpass_mode,
1092                            StaticLookupMode static_mode,
1093                            PrivateLookupMode private_mode) const;
1094 
1095   static Method* find_method_impl(const Array<Method*>* methods,
1096                                   const Symbol* name,
1097                                   const Symbol* signature,
1098                                   OverpassLookupMode overpass_mode,
1099                                   StaticLookupMode static_mode,
1100                                   PrivateLookupMode private_mode);
1101 
1102 #if INCLUDE_JVMTI
1103   // RedefineClasses support
1104   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1105   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1106 #endif
1107   // log class name to classlist
1108   void log_to_classlist() const;
1109 public:
1110 
1111 #if INCLUDE_CDS
1112   // CDS support - remove and restore oops from metadata. Oops are not shared.
1113   virtual void remove_unshareable_info();
1114   void remove_unshareable_flags();
1115   virtual void remove_java_mirror();
1116   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1117   void init_shared_package_entry();
1118   bool can_be_verified_at_dumptime() const;
1119   bool methods_contain_jsr_bytecode() const;
1120   void compute_has_loops_flag_for_methods();
1121 #endif
1122 
1123   jint compute_modifier_flags() const;
1124 
1125 public:
1126   // JVMTI support
1127   jint jvmti_class_status() const;
1128 
1129   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1130 
1131  public:
1132   // Printing
1133   void print_on(outputStream* st) const;
1134   void print_value_on(outputStream* st) const;
1135 
1136   void oop_print_value_on(oop obj, outputStream* st);
1137 
1138   void oop_print_on      (oop obj, outputStream* st);
1139 
1140 #ifndef PRODUCT
1141   void print_dependent_nmethods(bool verbose = false);
1142   bool is_dependent_nmethod(nmethod* nm);
1143   bool verify_itable_index(int index);
1144 #endif
1145 
1146   const char* internal_name() const;
1147 
1148   // Verification
1149   void verify_on(outputStream* st);
1150 
1151   void oop_verify_on(oop obj, outputStream* st);
1152 
1153   // Logging
1154   void print_class_load_logging(ClassLoaderData* loader_data,
1155                                 const ModuleEntry* module_entry,
1156                                 const ClassFileStream* cfs) const;
1157  private:
1158   void print_class_load_cause_logging() const;
1159   void print_class_load_helper(ClassLoaderData* loader_data,
1160                                const ModuleEntry* module_entry,
1161                                const ClassFileStream* cfs) const;
1162 };
1163 
1164 // for adding methods
1165 // UNSET_IDNUM return means no more ids available
1166 inline u2 InstanceKlass::next_method_idnum() {
1167   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1168     return ConstMethod::UNSET_IDNUM; // no more ids available
1169   } else {
1170     return _idnum_allocated_count++;
1171   }
1172 }
1173 
1174 class PrintClassClosure : public KlassClosure {
1175 private:
1176   outputStream* _st;
1177   bool _verbose;
1178 public:
1179   PrintClassClosure(outputStream* st, bool verbose);
1180 
1181   void do_klass(Klass* k);
1182 };
1183 
1184 /* JNIid class for jfieldIDs only */
1185 class JNIid: public CHeapObj<mtClass> {
1186   friend class VMStructs;
1187  private:
1188   Klass*             _holder;
1189   JNIid*             _next;
1190   int                _offset;
1191 #ifdef ASSERT
1192   bool               _is_static_field_id;
1193 #endif
1194 
1195  public:
1196   // Accessors
1197   Klass* holder() const           { return _holder; }
1198   int offset() const              { return _offset; }
1199   JNIid* next()                   { return _next; }
1200   // Constructor
1201   JNIid(Klass* holder, int offset, JNIid* next);
1202   // Identifier lookup
1203   JNIid* find(int offset);
1204 
1205   bool find_local_field(fieldDescriptor* fd) {
1206     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1207   }
1208 
1209   static void deallocate(JNIid* id);
1210   // Debugging
1211 #ifdef ASSERT
1212   bool is_static_field_id() const { return _is_static_field_id; }
1213   void set_is_static_field_id()   { _is_static_field_id = true; }
1214 #endif
1215   void verify(Klass* holder);
1216 };
1217 
1218 // An iterator that's used to access the inner classes indices in the
1219 // InstanceKlass::_inner_classes array.
1220 class InnerClassesIterator : public StackObj {
1221  private:
1222   Array<jushort>* _inner_classes;
1223   int _length;
1224   int _idx;
1225  public:
1226 
1227   InnerClassesIterator(const InstanceKlass* k) {
1228     _inner_classes = k->inner_classes();
1229     if (k->inner_classes() != nullptr) {
1230       _length = _inner_classes->length();
1231       // The inner class array's length should be the multiple of
1232       // inner_class_next_offset if it only contains the InnerClasses
1233       // attribute data, or it should be
1234       // n*inner_class_next_offset+enclosing_method_attribute_size
1235       // if it also contains the EnclosingMethod data.
1236       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1237               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1238              "just checking");
1239       // Remove the enclosing_method portion if exists.
1240       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1241         _length -= InstanceKlass::enclosing_method_attribute_size;
1242       }
1243     } else {
1244       _length = 0;
1245     }
1246     _idx = 0;
1247   }
1248 
1249   int length() const {
1250     return _length;
1251   }
1252 
1253   void next() {
1254     _idx += InstanceKlass::inner_class_next_offset;
1255   }
1256 
1257   bool done() const {
1258     return (_idx >= _length);
1259   }
1260 
1261   u2 inner_class_info_index() const {
1262     return _inner_classes->at(
1263                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1264   }
1265 
1266   void set_inner_class_info_index(u2 index) {
1267     _inner_classes->at_put(
1268                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1269   }
1270 
1271   u2 outer_class_info_index() const {
1272     return _inner_classes->at(
1273                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1274   }
1275 
1276   void set_outer_class_info_index(u2 index) {
1277     _inner_classes->at_put(
1278                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1279   }
1280 
1281   u2 inner_name_index() const {
1282     return _inner_classes->at(
1283                _idx + InstanceKlass::inner_class_inner_name_offset);
1284   }
1285 
1286   void set_inner_name_index(u2 index) {
1287     _inner_classes->at_put(
1288                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1289   }
1290 
1291   u2 inner_access_flags() const {
1292     return _inner_classes->at(
1293                _idx + InstanceKlass::inner_class_access_flags_offset);
1294   }
1295 };
1296 
1297 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1298 // Usage:
1299 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1300 //    Klass* k = iter.klass();
1301 //    ...
1302 //  }
1303 class ClassHierarchyIterator : public StackObj {
1304  private:
1305   InstanceKlass* _root;
1306   Klass*         _current;
1307   bool           _visit_subclasses;
1308 
1309  public:
1310   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1311     assert(_root == _current, "required"); // initial state
1312   }
1313 
1314   bool done() {
1315     return (_current == nullptr);
1316   }
1317 
1318   // Make a step iterating over the class hierarchy under the root class.
1319   // Skips subclasses if requested.
1320   void next();
1321 
1322   Klass* klass() {
1323     assert(!done(), "sanity");
1324     return _current;
1325   }
1326 
1327   // Skip subclasses of the current class.
1328   void skip_subclasses() {
1329     _visit_subclasses = false;
1330   }
1331 };
1332 
1333 #endif // SHARE_OOPS_INSTANCEKLASS_HPP