1 /*
   2  * Copyright (c) 1997, 2025, 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
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  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 RecordComponent;
  49 
  50 // An InstanceKlass is the VM level representation of a Java class.
  51 // It contains all information needed for at class at execution runtime.
  52 
  53 //  InstanceKlass embedded field layout (after declared fields):
  54 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  55 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  56 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  57 //      indicating where oops are located in instances of this klass.
  58 //    [EMBEDDED implementor of the interface] only exist for interface
  59 
  60 
  61 // forward declaration for class -- see below for definition
  62 #if INCLUDE_JVMTI
  63 class BreakpointInfo;
  64 #endif
  65 class ClassFileParser;
  66 class ClassFileStream;
  67 class KlassDepChange;
  68 class DependencyContext;
  69 class fieldDescriptor;
  70 class JNIid;
  71 class JvmtiCachedClassFieldMap;
  72 class nmethodBucket;
  73 class OopMapCache;
  74 class InterpreterOopMap;
  75 class PackageEntry;
  76 class ModuleEntry;
  77 
  78 // This is used in iterators below.
  79 class FieldClosure: public StackObj {
  80 public:
  81   virtual void do_field(fieldDescriptor* fd) = 0;
  82 };
  83 
  84 // Print fields.
  85 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  86 class FieldPrinter: public FieldClosure {
  87    oop _obj;
  88    outputStream* _st;
  89  public:
  90    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  91    void do_field(fieldDescriptor* fd);
  92 };
  93 
  94 // Describes where oops are located in instances of this klass.
  95 class OopMapBlock {
  96  public:
  97   // Byte offset of the first oop mapped by this block.
  98   int offset() const          { return _offset; }
  99   void set_offset(int offset) { _offset = offset; }
 100 
 101   // Number of oops in this block.
 102   uint count() const         { return _count; }
 103   void set_count(uint count) { _count = count; }
 104 
 105   void increment_count(int diff) { _count += diff; }
 106 
 107   int offset_span() const { return _count * heapOopSize; }
 108 
 109   int end_offset() const {
 110     return offset() + offset_span();
 111   }
 112 
 113   bool is_contiguous(int another_offset) const {
 114     return another_offset == end_offset();
 115   }
 116 
 117   // sizeof(OopMapBlock) in words.
 118   static int size_in_words() {
 119     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 120       LogBytesPerWord;
 121   }
 122 
 123   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 124     return a->offset() - b->offset();
 125   }
 126 
 127  private:
 128   int  _offset;
 129   uint _count;
 130 };
 131 
 132 struct JvmtiCachedClassFileData;
 133 
 134 class InstanceKlass: public Klass {
 135   friend class VMStructs;
 136   friend class JVMCIVMStructs;
 137   friend class ClassFileParser;
 138   friend class CompileReplay;
 139 
 140  public:
 141   static const KlassKind Kind = InstanceKlassKind;
 142 
 143  protected:
 144   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 145 
 146  public:
 147   InstanceKlass();
 148 
 149   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 150   // of the class loading & initialization procedure, and the use of the states.
 151   enum ClassState : u1 {
 152     allocated,                          // allocated (but not yet linked)
 153     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 154     linked,                             // successfully linked/verified (but not initialized yet)
 155     being_initialized,                  // currently running class initializer
 156     fully_initialized,                  // initialized (successful final state)
 157     initialization_error                // error happened during initialization
 158   };
 159 
 160  private:
 161   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 162 
 163  protected:
 164   // If you add a new field that points to any metaspace object, you
 165   // must add this field to InstanceKlass::metaspace_pointers_do().
 166 
 167   // Annotations for this class
 168   Annotations*    _annotations;
 169   // Package this class is defined in
 170   PackageEntry*   _package_entry;
 171   // Array classes holding elements of this class.
 172   ObjArrayKlass* volatile _array_klasses;
 173   // Constant pool for this class.
 174   ConstantPool* _constants;
 175   // The InnerClasses attribute and EnclosingMethod attribute. The
 176   // _inner_classes is an array of shorts. If the class has InnerClasses
 177   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 178   // [inner_class_info_index, outer_class_info_index,
 179   // inner_name_index, inner_class_access_flags] for the InnerClasses
 180   // attribute. If the EnclosingMethod attribute exists, it occupies the
 181   // last two shorts [class_index, method_index] of the array. If only
 182   // the InnerClasses attribute exists, the _inner_classes array length is
 183   // number_of_inner_classes * 4. If the class has both InnerClasses
 184   // and EnclosingMethod attributes the _inner_classes array length is
 185   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 186   Array<jushort>* _inner_classes;
 187 
 188   // The NestMembers attribute. An array of shorts, where each is a
 189   // class info index for the class that is a nest member. This data
 190   // has not been validated.
 191   Array<jushort>* _nest_members;
 192 
 193   // Resolved nest-host klass: either true nest-host or self if we are not
 194   // nested, or an error occurred resolving or validating the nominated
 195   // nest-host. Can also be set directly by JDK API's that establish nest
 196   // relationships.
 197   // By always being set it makes nest-member access checks simpler.
 198   InstanceKlass* _nest_host;
 199 
 200   // The PermittedSubclasses attribute. An array of shorts, where each is a
 201   // class info index for the class that is a permitted subclass.
 202   Array<jushort>* _permitted_subclasses;
 203 
 204   // The contents of the Record attribute.
 205   Array<RecordComponent*>* _record_components;
 206 
 207   // the source debug extension for this klass, null if not specified.
 208   // Specified as UTF-8 string without terminating zero byte in the classfile,
 209   // it is stored in the instanceklass as a null-terminated UTF-8 string
 210   const char*     _source_debug_extension;
 211 
 212   // Number of heapOopSize words used by non-static fields in this klass
 213   // (including inherited fields but after header_size()).
 214   int             _nonstatic_field_size;
 215   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 216   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 217   int             _itable_len;              // length of Java itable (in words)
 218 
 219   // The NestHost attribute. The class info index for the class
 220   // that is the nest-host of this class. This data has not been validated.
 221   u2              _nest_host_index;
 222   u2              _this_class_index;        // constant pool entry
 223   u2              _static_oop_field_count;  // number of static oop fields in this klass
 224 
 225   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 226 
 227   // Class states are defined as ClassState (see above).
 228   // Place the _init_state here to utilize the unused 2-byte after
 229   // _idnum_allocated_count.
 230   volatile ClassState _init_state;          // state of class
 231 
 232   u1                 _reference_type;                // reference type
 233 
 234   AccessFlags        _access_flags;    // Access flags. The class/interface distinction is stored here.
 235 
 236   // State is set either at parse time or while executing, atomically to not disturb other state
 237   InstanceKlassFlags _misc_flags;
 238 
 239   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 240 
 241   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 242   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 243   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 244   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 245   uint64_t        volatile _dep_context_last_cleaned;
 246   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 247 #if INCLUDE_JVMTI
 248   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 249   // Linked instanceKlasses of previous versions
 250   InstanceKlass* _previous_versions;
 251   // JVMTI fields can be moved to their own structure - see 6315920
 252   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 253   JvmtiCachedClassFileData* _cached_class_file;
 254 #endif
 255 
 256 #if INCLUDE_JVMTI
 257   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 258 #endif
 259 
 260   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 261   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 262 
 263   // Method array.
 264   Array<Method*>* _methods;
 265   // Default Method Array, concrete methods inherited from interfaces
 266   Array<Method*>* _default_methods;
 267   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 268   Array<InstanceKlass*>* _local_interfaces;
 269   // Interfaces (InstanceKlass*s) this class implements transitively.
 270   Array<InstanceKlass*>* _transitive_interfaces;
 271   // Int array containing the original order of method in the class file (for JVMTI).
 272   Array<int>*     _method_ordering;
 273   // Int array containing the vtable_indices for default_methods
 274   // offset matches _default_methods offset
 275   Array<int>*     _default_vtable_indices;
 276 
 277   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 278   Array<u1>*          _fieldinfo_stream;
 279   Array<u1>*          _fieldinfo_search_table;
 280   Array<FieldStatus>* _fields_status;
 281 
 282   // embedded Java vtable follows here
 283   // embedded Java itables follows here
 284   // embedded static fields follows here
 285   // embedded nonstatic oop-map blocks follows here
 286   // embedded implementor of this interface follows here
 287   //   The embedded implementor only exists if the current klass is an
 288   //   interface. The possible values of the implementor fall into following
 289   //   three cases:
 290   //     null: no implementor.
 291   //     A Klass* that's not itself: one implementor.
 292   //     Itself: more than one implementors.
 293   //
 294 
 295   friend class SystemDictionary;
 296 
 297   static bool _disable_method_binary_search;
 298 
 299   // Controls finalizer registration
 300   static bool _finalization_enabled;
 301 
 302  public:
 303 
 304   // Queries finalization state
 305   static bool is_finalization_enabled() { return _finalization_enabled; }
 306 
 307   // Sets finalization state
 308   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 309 
 310   // Access flags
 311   AccessFlags access_flags() const         { return _access_flags;  }
 312   void set_access_flags(AccessFlags flags) { _access_flags = flags; }
 313 
 314   bool is_public() const                { return _access_flags.is_public(); }
 315   bool is_final() const                 { return _access_flags.is_final(); }
 316   bool is_interface() const override    { return _access_flags.is_interface(); }
 317   bool is_abstract() const override     { return _access_flags.is_abstract(); }
 318   bool is_super() const                 { return _access_flags.is_super(); }
 319   bool is_synthetic() const             { return _access_flags.is_synthetic(); }
 320   void set_is_synthetic()               { _access_flags.set_is_synthetic(); }
 321 
 322   static ByteSize access_flags_offset() { return byte_offset_of(InstanceKlass, _access_flags); }
 323 
 324   void set_is_cloneable();
 325 
 326   // Quick checks for the loader that defined this class (without switching on this->class_loader())
 327   bool defined_by_boot_loader() const      { return _misc_flags.defined_by_boot_loader(); }
 328   bool defined_by_platform_loader() const  { return _misc_flags.defined_by_platform_loader(); }
 329   bool defined_by_app_loader() const       { return _misc_flags.defined_by_app_loader(); }
 330   bool defined_by_other_loaders() const    { return _misc_flags.defined_by_other_loaders(); }
 331   void set_class_loader_type()             { _misc_flags.set_class_loader_type(_class_loader_data); }
 332 
 333   // Check if the class can be shared in CDS
 334   bool is_shareable() const;
 335 
 336   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 337 
 338   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 339 
 340   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 341   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 342 
 343   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 344   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 345 
 346   // field sizes
 347   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 348   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 349 
 350   int static_field_size() const            { return _static_field_size; }
 351   void set_static_field_size(int size)     { _static_field_size = size; }
 352 
 353   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 354   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 355 
 356   // Java itable
 357   int  itable_length() const               { return _itable_len; }
 358   void set_itable_length(int len)          { _itable_len = len; }
 359 
 360   // array klasses
 361   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 362   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 363   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 364   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 365 
 366   // methods
 367   Array<Method*>* methods() const          { return _methods; }
 368   void set_methods(Array<Method*>* a)      { _methods = a; }
 369   Method* method_with_idnum(int idnum) const;
 370   Method* method_with_orig_idnum(int idnum) const;
 371   Method* method_with_orig_idnum(int idnum, int version) const;
 372 
 373   // method ordering
 374   Array<int>* method_ordering() const     { return _method_ordering; }
 375   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 376   void copy_method_ordering(const intArray* m, TRAPS);
 377 
 378   // default_methods
 379   Array<Method*>* default_methods() const  { return _default_methods; }
 380   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 381 
 382   // default method vtable_indices
 383   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 384   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 385   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 386 
 387   // interfaces
 388   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 389   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 390     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 391     _local_interfaces = a; }
 392 
 393   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 394   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 395     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 396     _transitive_interfaces = a;
 397   }
 398 
 399  private:
 400   friend class fieldDescriptor;
 401   FieldInfo field(int index) const;
 402 
 403  public:
 404   int     field_offset      (int index) const { return field(index).offset(); }
 405   int     field_access_flags(int index) const { return field(index).access_flags().as_field_flags(); }
 406   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 407   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 408   inline Symbol* field_name        (int index) const;
 409   inline Symbol* field_signature   (int index) const;
 410 
 411   // Number of Java declared fields
 412   int java_fields_count() const;
 413   int total_fields_count() const;
 414 
 415   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 416   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 417 
 418   Array<u1>* fieldinfo_search_table() const { return _fieldinfo_search_table; }
 419   void set_fieldinfo_search_table(Array<u1>* table) { _fieldinfo_search_table = table; }
 420 
 421   Array<FieldStatus>* fields_status() const {return _fields_status; }
 422   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 423 
 424   // inner classes
 425   Array<u2>* inner_classes() const       { return _inner_classes; }
 426   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 427 
 428   // nest members
 429   Array<u2>* nest_members() const     { return _nest_members; }
 430   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 431 
 432   // nest-host index
 433   jushort nest_host_index() const { return _nest_host_index; }
 434   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 435   // dynamic nest member support
 436   void set_nest_host(InstanceKlass* host);
 437 
 438   // record components
 439   Array<RecordComponent*>* record_components() const { return _record_components; }
 440   void set_record_components(Array<RecordComponent*>* record_components) {
 441     _record_components = record_components;
 442   }
 443   bool is_record() const;
 444 
 445   // test for enum class (or possibly an anonymous subclass within a sealed enum)
 446   bool is_enum_subclass() const;
 447 
 448   // permitted subclasses
 449   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 450   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 451 
 452 private:
 453   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 454   // nor does it resolve any CP entries or load any classes.
 455   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 456 
 457 public:
 458   // Call this only if you know that the nest host has been initialized.
 459   InstanceKlass* nest_host_not_null() {
 460     assert(_nest_host != nullptr, "must be");
 461     return _nest_host;
 462   }
 463   InstanceKlass* nest_host_or_null() {
 464     return _nest_host;
 465   }
 466   // Used to construct informative IllegalAccessError messages at a higher level,
 467   // if there was an issue resolving or validating the nest host.
 468   // Returns null if there was no error.
 469   const char* nest_host_error();
 470   // Returns nest-host class, resolving and validating it if needed.
 471   // Returns null if resolution is not possible from the calling context.
 472   InstanceKlass* nest_host(TRAPS);
 473   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 474   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 475 
 476   // Called to verify that k is a permitted subclass of this class.
 477   // The incoming stringStream is used for logging, and for the caller to create
 478   // a detailed exception message on failure.
 479   bool has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const;
 480 
 481   enum InnerClassAttributeOffset {
 482     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 483     inner_class_inner_class_info_offset = 0,
 484     inner_class_outer_class_info_offset = 1,
 485     inner_class_inner_name_offset = 2,
 486     inner_class_access_flags_offset = 3,
 487     inner_class_next_offset = 4
 488   };
 489 
 490   enum EnclosingMethodAttributeOffset {
 491     enclosing_method_class_index_offset = 0,
 492     enclosing_method_method_index_offset = 1,
 493     enclosing_method_attribute_size = 2
 494   };
 495 
 496   // package
 497   PackageEntry* package() const override { return _package_entry; }
 498   ModuleEntry* module() const override;
 499   bool in_javabase_module() const;
 500   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 501   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 502   // If the package for the InstanceKlass is in the boot loader's package entry
 503   // table then sets the classpath_index field so that
 504   // get_system_package() will know to return a non-null value for the
 505   // package's location.  And, so that the package will be added to the list of
 506   // packages returned by get_system_packages().
 507   // For packages whose classes are loaded from the boot loader class path, the
 508   // classpath_index indicates which entry on the boot loader class path.
 509   void set_classpath_index(s2 path_index);
 510   bool is_same_class_package(const Klass* class2) const;
 511   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 512 
 513   // find an enclosing class
 514   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 515 
 516   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 517   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 518 
 519  private:
 520   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 521   static void check_prohibited_package(Symbol* class_name,
 522                                        ClassLoaderData* loader_data,
 523                                        TRAPS);
 524 
 525   JavaThread* init_thread()  { return AtomicAccess::load(&_init_thread); }
 526   const char* init_thread_name() {
 527     return init_thread()->name_raw();
 528   }
 529 
 530  public:
 531   // initialization state
 532   bool is_loaded() const                   { return init_state() >= loaded; }
 533   bool is_linked() const                   { return init_state() >= linked; }
 534   bool is_initialized() const              { return init_state() == fully_initialized; }
 535   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 536   bool is_being_initialized() const        { return init_state() == being_initialized; }
 537   bool is_in_error_state() const           { return init_state() == initialization_error; }
 538   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 539   ClassState  init_state() const           { return AtomicAccess::load_acquire(&_init_state); }
 540   const char* init_state_name() const;
 541   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 542 
 543   // is this a sealed class
 544   bool is_sealed() const;
 545 
 546   // defineClass specified verification
 547   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 548   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 549 
 550   // marking
 551   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 552   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 553 
 554   // initialization (virtuals from Klass)
 555   bool should_be_initialized() const override;  // means that initialize should be called
 556   void initialize_with_aot_initialized_mirror(TRAPS);
 557   void assert_no_clinit_will_run_for_aot_initialized_class() const NOT_DEBUG_RETURN;
 558   void initialize(TRAPS) override;
 559   void initialize_preemptable(TRAPS) override;
 560   void link_class(TRAPS);
 561   bool link_class_or_fail(TRAPS); // returns false on failure
 562   void rewrite_class(TRAPS);
 563   void link_methods(TRAPS);
 564   Method* class_initializer() const;
 565   bool interface_needs_clinit_execution_as_super(bool also_check_supers=true) const;
 566 
 567   // reference type
 568   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 569 
 570   // this class cp index
 571   u2 this_class_index() const             { return _this_class_index; }
 572   void set_this_class_index(u2 index)     { _this_class_index = index; }
 573 
 574   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 575 
 576   // find local field, returns true if found
 577   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 578   // find field in direct superinterfaces, returns the interface in which the field is defined
 579   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 580   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 581   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const override;
 582   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 583   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 584 
 585   // find a non-static or static field given its offset within the class.
 586   bool contains_field_offset(int offset);
 587 
 588   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 589   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 590 
 591  private:
 592   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 593 
 594  public:
 595   static void disable_method_binary_search() {
 596     _disable_method_binary_search = true;
 597   }
 598 
 599   // find a local method (returns null if not found)
 600   Method* find_method(const Symbol* name, const Symbol* signature) const;
 601   static Method* find_method(const Array<Method*>* methods,
 602                              const Symbol* name,
 603                              const Symbol* signature);
 604 
 605   // find a local method, but skip static methods
 606   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 607                                PrivateLookupMode private_mode) const;
 608   static Method* find_instance_method(const Array<Method*>* methods,
 609                                       const Symbol* name,
 610                                       const Symbol* signature,
 611                                       PrivateLookupMode private_mode);
 612 
 613   // find a local method (returns null if not found)
 614   Method* find_local_method(const Symbol* name,
 615                             const Symbol* signature,
 616                             OverpassLookupMode overpass_mode,
 617                             StaticLookupMode static_mode,
 618                             PrivateLookupMode private_mode) const;
 619 
 620   // find a local method from given methods array (returns null if not found)
 621   static Method* find_local_method(const Array<Method*>* methods,
 622                                    const Symbol* name,
 623                                    const Symbol* signature,
 624                                    OverpassLookupMode overpass_mode,
 625                                    StaticLookupMode static_mode,
 626                                    PrivateLookupMode private_mode);
 627 
 628   // find a local method index in methods or default_methods (returns -1 if not found)
 629   static int find_method_index(const Array<Method*>* methods,
 630                                const Symbol* name,
 631                                const Symbol* signature,
 632                                OverpassLookupMode overpass_mode,
 633                                StaticLookupMode static_mode,
 634                                PrivateLookupMode private_mode);
 635 
 636   // lookup operation (returns null if not found)
 637   Method* uncached_lookup_method(const Symbol* name,
 638                                  const Symbol* signature,
 639                                  OverpassLookupMode overpass_mode,
 640                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const override;
 641 
 642   // lookup a method in all the interfaces that this class implements
 643   // (returns null if not found)
 644   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 645 
 646   // lookup a method in local defaults then in all interfaces
 647   // (returns null if not found)
 648   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 649 
 650   // Find method indices by name.  If a method with the specified name is
 651   // found the index to the first method is returned, and 'end' is filled in
 652   // with the index of first non-name-matching method.  If no method is found
 653   // -1 is returned.
 654   int find_method_by_name(const Symbol* name, int* end) const;
 655   static int find_method_by_name(const Array<Method*>* methods,
 656                                  const Symbol* name, int* end);
 657 
 658   // constant pool
 659   ConstantPool* constants() const        { return _constants; }
 660   void set_constants(ConstantPool* c)    { _constants = c; }
 661 
 662   // protection domain
 663   oop protection_domain() const override;
 664 
 665   // signers
 666   objArrayOop signers() const;
 667 
 668   bool is_contended() const                { return _misc_flags.is_contended(); }
 669   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 670 
 671   // source file name
 672   Symbol* source_file_name() const;
 673   u2 source_file_name_index() const;
 674   void set_source_file_name_index(u2 sourcefile_index);
 675 
 676   // minor and major version numbers of class file
 677   u2 minor_version() const;
 678   void set_minor_version(u2 minor_version);
 679   u2 major_version() const;
 680   void set_major_version(u2 major_version);
 681 
 682   // source debug extension
 683   const char* source_debug_extension() const { return _source_debug_extension; }
 684   void set_source_debug_extension(const char* array, int length);
 685 
 686   // nonstatic oop-map blocks
 687   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 688     return oop_map_count * OopMapBlock::size_in_words();
 689   }
 690   unsigned int nonstatic_oop_map_count() const {
 691     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 692   }
 693   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 694   void set_nonstatic_oop_map_size(int words) {
 695     _nonstatic_oop_map_size = words;
 696   }
 697 
 698   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 699   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 700 
 701 #if INCLUDE_JVMTI
 702   // Redefinition locking.  Class can only be redefined by one thread at a time.
 703   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 704   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 705 
 706   // RedefineClasses() support for previous versions:
 707   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 708   void purge_previous_version_list();
 709 
 710   InstanceKlass* previous_versions() const { return _previous_versions; }
 711 #else
 712   InstanceKlass* previous_versions() const { return nullptr; }
 713 #endif
 714 
 715   const InstanceKlass* get_klass_version(int version) const;
 716 
 717   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 718   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 719 
 720   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 721   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 722 
 723   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 724   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 725   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 726 
 727 public:
 728 #if INCLUDE_JVMTI
 729 
 730   void init_previous_versions() {
 731     _previous_versions = nullptr;
 732   }
 733 
 734  private:
 735   static bool  _should_clean_previous_versions;
 736  public:
 737   static void purge_previous_versions(InstanceKlass* ik) {
 738     if (ik->has_been_redefined()) {
 739       ik->purge_previous_version_list();
 740     }
 741   }
 742 
 743   static bool should_clean_previous_versions_and_reset();
 744   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 745 
 746   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 747   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 748     _cached_class_file = data;
 749   }
 750   JvmtiCachedClassFileData * get_cached_class_file();
 751   jint get_cached_class_file_len();
 752   unsigned char * get_cached_class_file_bytes();
 753 
 754   // JVMTI: Support for caching of field indices, types, and offsets
 755   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 756     _jvmti_cached_class_field_map = descriptor;
 757   }
 758   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 759     return _jvmti_cached_class_field_map;
 760   }
 761 #else // INCLUDE_JVMTI
 762 
 763   static void purge_previous_versions(InstanceKlass* ik) { return; };
 764   static bool should_clean_previous_versions_and_reset() { return false; }
 765 
 766   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 767     assert(data == nullptr, "unexpected call with JVMTI disabled");
 768   }
 769   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 770 
 771 #endif // INCLUDE_JVMTI
 772 
 773   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 774   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 775 
 776   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 777   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 778 
 779   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 780   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 781   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 782   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 783 
 784   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 785   inline u2 next_method_idnum();
 786   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 787 
 788   // generics support
 789   Symbol* generic_signature() const;
 790   u2 generic_signature_index() const;
 791   void set_generic_signature_index(u2 sig_index);
 792 
 793   u2 enclosing_method_data(int offset) const;
 794   u2 enclosing_method_class_index() const {
 795     return enclosing_method_data(enclosing_method_class_index_offset);
 796   }
 797   u2 enclosing_method_method_index() {
 798     return enclosing_method_data(enclosing_method_method_index_offset);
 799   }
 800   void set_enclosing_method_indices(u2 class_index,
 801                                     u2 method_index);
 802 
 803   // jmethodID support
 804   jmethodID get_jmethod_id(Method* method);
 805   void make_methods_jmethod_ids();
 806   jmethodID jmethod_id_or_null(Method* method);
 807   void update_methods_jmethod_cache();
 808 
 809   // annotations support
 810   Annotations* annotations() const          { return _annotations; }
 811   void set_annotations(Annotations* anno)   { _annotations = anno; }
 812 
 813   AnnotationArray* class_annotations() const {
 814     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 815   }
 816   Array<AnnotationArray*>* fields_annotations() const {
 817     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 818   }
 819   AnnotationArray* class_type_annotations() const {
 820     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 821   }
 822   Array<AnnotationArray*>* fields_type_annotations() const {
 823     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 824   }
 825   // allocation
 826   instanceOop allocate_instance(TRAPS);
 827   static instanceOop allocate_instance(oop cls, TRAPS);
 828 
 829   // additional member function to return a handle
 830   instanceHandle allocate_instance_handle(TRAPS);
 831 
 832   // Helper function
 833   static instanceOop register_finalizer(instanceOop i, TRAPS);
 834 
 835   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 836   // if not, throw either an Error or an Exception.
 837   void check_valid_for_instantiation(bool throwError, TRAPS) override;
 838 
 839   // initialization
 840   void call_class_initializer(TRAPS);
 841   void set_initialization_state_and_notify(ClassState state, TRAPS);
 842 
 843   // OopMapCache support
 844   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 845   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 846   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 847 
 848   // JNI identifier support (for static fields - for jni performance)
 849   JNIid* jni_ids()                               { return _jni_ids; }
 850   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 851   JNIid* jni_id_for(int offset);
 852 
 853  public:
 854   // maintenance of deoptimization dependencies
 855   inline DependencyContext dependencies();
 856   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 857   void add_dependent_nmethod(nmethod* nm);
 858   void clean_dependency_context();
 859   // Setup link to hierarchy and deoptimize
 860   void add_to_hierarchy(JavaThread* current);
 861 
 862   // On-stack replacement support
 863   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 864   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 865   void add_osr_nmethod(nmethod* n);
 866   bool remove_osr_nmethod(nmethod* n);
 867   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 868   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 869 
 870 #if INCLUDE_JVMTI
 871   // Breakpoint support (see methods on Method* for details)
 872   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 873   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 874 #endif
 875 
 876   // support for stub routines
 877   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 878   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 879   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 880 
 881   // subclass/subinterface checks
 882   bool implements_interface(Klass* k) const;
 883   bool is_same_or_direct_interface(Klass* k) const;
 884 
 885 #ifdef ASSERT
 886   // check whether this class or one of its superclasses was redefined
 887   bool has_redefined_this_or_super() const;
 888 #endif
 889 
 890   // Access to the implementor of an interface.
 891   InstanceKlass* implementor() const;
 892   void set_implementor(InstanceKlass* ik);
 893   int  nof_implementors() const;
 894   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 895   void init_implementor();           // initialize
 896 
 897  private:
 898   // link this class into the implementors list of every interface it implements
 899   void process_interfaces();
 900 
 901  public:
 902   // virtual operations from Klass
 903   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 904                                                   Array<InstanceKlass*>* transitive_interfaces) override;
 905   bool can_be_primary_super_slow() const override;
 906   size_t oop_size(oop obj) const override { return size_helper(); }
 907   // slow because it's a virtual call and used for verifying the layout_helper.
 908   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 909   DEBUG_ONLY(bool is_instance_klass_slow() const override { return true; })
 910 
 911   // Iterators
 912   void do_local_static_fields(FieldClosure* cl);
 913   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 914   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 915   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 916 
 917   void methods_do(void f(Method* method));
 918 
 919   static InstanceKlass* cast(Klass* k) {
 920     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 921   }
 922 
 923   static const InstanceKlass* cast(const Klass* k) {
 924     assert(k != nullptr, "k should not be null");
 925     assert(k->is_instance_klass(), "cast to InstanceKlass");
 926     return static_cast<const InstanceKlass*>(k);
 927   }
 928 
 929   // This hides Klass::super(). The _super of an InstanceKlass is
 930   // always an InstanceKlass (or nullptr)
 931   InstanceKlass* super() const {
 932     return (Klass::super() == nullptr) ? nullptr : InstanceKlass::cast(Klass::super());
 933   }
 934 
 935   InstanceKlass* java_super() const override {
 936     return InstanceKlass::super();
 937   }
 938 
 939   // Sizing (in words)
 940   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
 941 
 942   static int size(int vtable_length, int itable_length,
 943                   int nonstatic_oop_map_size,
 944                   bool is_interface) {
 945     return align_metadata_size(header_size() +
 946            vtable_length +
 947            itable_length +
 948            nonstatic_oop_map_size +
 949            (is_interface ? (int)sizeof(Klass*)/wordSize : 0));
 950   }
 951 
 952   int size() const override           { return size(vtable_length(),
 953                                                     itable_length(),
 954                                                     nonstatic_oop_map_size(),
 955                                                     is_interface());
 956   }
 957 
 958 
 959   inline intptr_t* start_of_itable() const;
 960   inline intptr_t* end_of_itable() const;
 961   inline oop static_field_base_raw();
 962 
 963   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
 964   inline Klass** end_of_nonstatic_oop_maps() const;
 965 
 966   inline InstanceKlass* volatile* adr_implementor() const;
 967 
 968   // Use this to return the size of an instance in heap words:
 969   int size_helper() const {
 970     return layout_helper_to_size_helper(layout_helper());
 971   }
 972 
 973   // This bit is initialized in classFileParser.cpp.
 974   // It is false under any of the following conditions:
 975   //  - the class is abstract (including any interface)
 976   //  - the class size is larger than FastAllocateSizeLimit
 977   //  - the class is java/lang/Class, which cannot be allocated directly
 978   bool can_be_fastpath_allocated() const {
 979     return !layout_helper_needs_slow_path(layout_helper());
 980   }
 981 
 982   // Java itable
 983   klassItable itable() const;        // return klassItable wrapper
 984   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
 985   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
 986   int vtable_index_of_interface_method(Method* method);
 987 
 988 #if INCLUDE_JVMTI
 989   void adjust_default_methods(bool* trace_name_printed);
 990 #endif // INCLUDE_JVMTI
 991 
 992   void clean_weak_instanceklass_links();
 993  private:
 994   void clean_implementors_list();
 995   void clean_method_data();
 996 
 997  public:
 998   // Explicit metaspace deallocation of fields
 999   // For RedefineClasses and class file parsing errors, we need to deallocate
1000   // instanceKlasses and the metadata they point to.
1001   void deallocate_contents(ClassLoaderData* loader_data);
1002   static void deallocate_methods(ClassLoaderData* loader_data,
1003                                  Array<Method*>* methods);
1004   void static deallocate_interfaces(ClassLoaderData* loader_data,
1005                                     const InstanceKlass* super_klass,
1006                                     Array<InstanceKlass*>* local_interfaces,
1007                                     Array<InstanceKlass*>* transitive_interfaces);
1008   void static deallocate_record_components(ClassLoaderData* loader_data,
1009                                            Array<RecordComponent*>* record_component);
1010 
1011   bool on_stack() const override;
1012 
1013   // callbacks for actions during class unloading
1014   static void unload_class(InstanceKlass* ik);
1015 
1016   void release_C_heap_structures(bool release_sub_metadata = true) override;
1017 
1018   // Naming
1019   const char* signature_name() const override;
1020 
1021   // Oop fields (and metadata) iterators
1022   //
1023   // The InstanceKlass iterators also visits the Object's klass.
1024 
1025   // Forward iteration
1026  public:
1027   // Iterate over all oop fields in the oop maps.
1028   template <typename T, class OopClosureType>
1029   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1030 
1031   // Iterate over all oop fields and metadata.
1032   template <typename T, class OopClosureType>
1033   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1034 
1035   // Iterate over all oop fields in one oop map.
1036   template <typename T, class OopClosureType>
1037   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1038 
1039 
1040   // Reverse iteration
1041   // Iterate over all oop fields and metadata.
1042   template <typename T, class OopClosureType>
1043   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1044 
1045  private:
1046   // Iterate over all oop fields in the oop maps.
1047   template <typename T, class OopClosureType>
1048   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1049 
1050   // Iterate over all oop fields in one oop map.
1051   template <typename T, class OopClosureType>
1052   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1053 
1054 
1055   // Bounded range iteration
1056  public:
1057   // Iterate over all oop fields in the oop maps.
1058   template <typename T, class OopClosureType>
1059   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1060 
1061   // Iterate over all oop fields and metadata.
1062   template <typename T, class OopClosureType>
1063   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1064 
1065  private:
1066   // Iterate over all oop fields in one oop map.
1067   template <typename T, class OopClosureType>
1068   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1069 
1070 
1071  public:
1072   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1073 
1074 private:
1075   // initialization state
1076   void set_init_state(ClassState state);
1077   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1078   void set_init_thread(JavaThread *thread)  {
1079     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1080            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1081     AtomicAccess::store(&_init_thread, thread);
1082   }
1083 
1084   jmethodID* methods_jmethod_ids_acquire() const;
1085   void release_set_methods_jmethod_ids(jmethodID* jmeths);
1086   // This nulls out obsolete jmethodIDs for all methods in 'klass'.
1087   static void clear_obsolete_jmethod_ids(InstanceKlass* klass);
1088   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1089 
1090 public:
1091   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1092   // Must be one per class and it has to be a VM internal object so java code
1093   // cannot lock it (like the mirror).
1094   // It has to be an object not a Mutex because it's held through java calls.
1095   oop init_lock() const;
1096 
1097   // Returns the array class for the n'th dimension
1098   ArrayKlass* array_klass(int n, TRAPS) override;
1099   ArrayKlass* array_klass_or_null(int n) override;
1100 
1101   // Returns the array class with this class as element type
1102   ArrayKlass* array_klass(TRAPS) override;
1103   ArrayKlass* array_klass_or_null() override;
1104 
1105   static void clean_initialization_error_table();
1106 private:
1107   void fence_and_clear_init_lock();
1108 
1109   bool link_class_impl                           (TRAPS);
1110   bool verify_code                               (TRAPS);
1111   void initialize_impl                           (TRAPS);
1112   void initialize_super_interfaces               (TRAPS);
1113 
1114   void add_initialization_error(JavaThread* current, Handle exception);
1115   oop get_initialization_error(JavaThread* current);
1116 
1117   // find a local method (returns null if not found)
1118   Method* find_method_impl(const Symbol* name,
1119                            const Symbol* signature,
1120                            OverpassLookupMode overpass_mode,
1121                            StaticLookupMode static_mode,
1122                            PrivateLookupMode private_mode) const;
1123 
1124   static Method* find_method_impl(const Array<Method*>* methods,
1125                                   const Symbol* name,
1126                                   const Symbol* signature,
1127                                   OverpassLookupMode overpass_mode,
1128                                   StaticLookupMode static_mode,
1129                                   PrivateLookupMode private_mode);
1130 
1131 #if INCLUDE_JVMTI
1132   // RedefineClasses support
1133   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1134   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1135 #endif
1136   // log class name to classlist
1137   void log_to_classlist() const;
1138 public:
1139 
1140 #if INCLUDE_CDS
1141   // CDS support - remove and restore oops from metadata. Oops are not shared.
1142   void remove_unshareable_info() override;
1143   void remove_unshareable_flags();
1144   void remove_java_mirror() override;
1145   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1146   void init_shared_package_entry();
1147   bool can_be_verified_at_dumptime() const;
1148   void compute_has_loops_flag_for_methods();
1149 #endif
1150   bool     has_init_deps_processed() const { return _misc_flags.has_init_deps_processed(); }
1151   void set_has_init_deps_processed() {
1152     assert(is_initialized(), "");
1153     assert(!has_init_deps_processed(), "already set"); // one-off action
1154     _misc_flags.set_has_init_deps_processed(true);
1155   }
1156 
1157   u2 compute_modifier_flags() const override;
1158 
1159 public:
1160   // JVMTI support
1161   jint jvmti_class_status() const override;
1162 
1163   void metaspace_pointers_do(MetaspaceClosure* iter) override;
1164 
1165  public:
1166   // Printing
1167   void print_on(outputStream* st) const override;
1168   void print_value_on(outputStream* st) const override;
1169 
1170   void oop_print_value_on(oop obj, outputStream* st) override;
1171 
1172   void oop_print_on      (oop obj, outputStream* st) override;
1173 
1174 #ifndef PRODUCT
1175   void print_dependent_nmethods(bool verbose = false);
1176   bool is_dependent_nmethod(nmethod* nm);
1177   bool verify_itable_index(int index);
1178 #endif
1179 
1180   const char* internal_name() const override;
1181 
1182   // Verification
1183   void verify_on(outputStream* st) override;
1184 
1185   void oop_verify_on(oop obj, outputStream* st) override;
1186 
1187   // Logging
1188   void print_class_load_logging(ClassLoaderData* loader_data,
1189                                 const ModuleEntry* module_entry,
1190                                 const ClassFileStream* cfs) const;
1191  private:
1192   void print_class_load_cause_logging() const;
1193   void print_class_load_helper(ClassLoaderData* loader_data,
1194                                const ModuleEntry* module_entry,
1195                                const ClassFileStream* cfs) const;
1196 };
1197 
1198 // for adding methods
1199 // UNSET_IDNUM return means no more ids available
1200 inline u2 InstanceKlass::next_method_idnum() {
1201   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1202     return ConstMethod::UNSET_IDNUM; // no more ids available
1203   } else {
1204     return _idnum_allocated_count++;
1205   }
1206 }
1207 
1208 class PrintClassClosure : public KlassClosure {
1209 private:
1210   outputStream* _st;
1211   bool _verbose;
1212 public:
1213   PrintClassClosure(outputStream* st, bool verbose);
1214 
1215   void do_klass(Klass* k);
1216 };
1217 
1218 /* JNIid class for jfieldIDs only */
1219 class JNIid: public CHeapObj<mtClass> {
1220   friend class VMStructs;
1221  private:
1222   InstanceKlass*     _holder;
1223   JNIid*             _next;
1224   int                _offset;
1225 #ifdef ASSERT
1226   bool               _is_static_field_id;
1227 #endif
1228 
1229  public:
1230   // Accessors
1231   InstanceKlass* holder() const   { return _holder; }
1232   int offset() const              { return _offset; }
1233   JNIid* next()                   { return _next; }
1234   // Constructor
1235   JNIid(InstanceKlass* holder, int offset, JNIid* next);
1236   // Identifier lookup
1237   JNIid* find(int offset);
1238 
1239   bool find_local_field(fieldDescriptor* fd) {
1240     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1241   }
1242 
1243   static void deallocate(JNIid* id);
1244   // Debugging
1245 #ifdef ASSERT
1246   bool is_static_field_id() const { return _is_static_field_id; }
1247   void set_is_static_field_id()   { _is_static_field_id = true; }
1248 #endif
1249   void verify(InstanceKlass* holder);
1250 };
1251 
1252 // An iterator that's used to access the inner classes indices in the
1253 // InstanceKlass::_inner_classes array.
1254 class InnerClassesIterator : public StackObj {
1255  private:
1256   Array<jushort>* _inner_classes;
1257   int _length;
1258   int _idx;
1259  public:
1260 
1261   InnerClassesIterator(const InstanceKlass* k) {
1262     _inner_classes = k->inner_classes();
1263     if (k->inner_classes() != nullptr) {
1264       _length = _inner_classes->length();
1265       // The inner class array's length should be the multiple of
1266       // inner_class_next_offset if it only contains the InnerClasses
1267       // attribute data, or it should be
1268       // n*inner_class_next_offset+enclosing_method_attribute_size
1269       // if it also contains the EnclosingMethod data.
1270       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1271               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1272              "just checking");
1273       // Remove the enclosing_method portion if exists.
1274       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1275         _length -= InstanceKlass::enclosing_method_attribute_size;
1276       }
1277     } else {
1278       _length = 0;
1279     }
1280     _idx = 0;
1281   }
1282 
1283   int length() const {
1284     return _length;
1285   }
1286 
1287   void next() {
1288     _idx += InstanceKlass::inner_class_next_offset;
1289   }
1290 
1291   bool done() const {
1292     return (_idx >= _length);
1293   }
1294 
1295   u2 inner_class_info_index() const {
1296     return _inner_classes->at(
1297                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1298   }
1299 
1300   void set_inner_class_info_index(u2 index) {
1301     _inner_classes->at_put(
1302                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1303   }
1304 
1305   u2 outer_class_info_index() const {
1306     return _inner_classes->at(
1307                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1308   }
1309 
1310   void set_outer_class_info_index(u2 index) {
1311     _inner_classes->at_put(
1312                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1313   }
1314 
1315   u2 inner_name_index() const {
1316     return _inner_classes->at(
1317                _idx + InstanceKlass::inner_class_inner_name_offset);
1318   }
1319 
1320   void set_inner_name_index(u2 index) {
1321     _inner_classes->at_put(
1322                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1323   }
1324 
1325   u2 inner_access_flags() const {
1326     return _inner_classes->at(
1327                _idx + InstanceKlass::inner_class_access_flags_offset);
1328   }
1329 };
1330 
1331 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1332 // Usage:
1333 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1334 //    Klass* k = iter.klass();
1335 //    ...
1336 //  }
1337 class ClassHierarchyIterator : public StackObj {
1338  private:
1339   InstanceKlass* _root;
1340   Klass*         _current;
1341   bool           _visit_subclasses;
1342 
1343  public:
1344   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1345     assert(_root == _current, "required"); // initial state
1346   }
1347 
1348   bool done() {
1349     return (_current == nullptr);
1350   }
1351 
1352   // Make a step iterating over the class hierarchy under the root class.
1353   // Skips subclasses if requested.
1354   void next();
1355 
1356   Klass* klass() {
1357     assert(!done(), "sanity");
1358     return _current;
1359   }
1360 
1361   // Skip subclasses of the current class.
1362   void skip_subclasses() {
1363     _visit_subclasses = false;
1364   }
1365 };
1366 
1367 #endif // SHARE_OOPS_INSTANCEKLASS_HPP