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 "code/vmreg.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "memory/referenceType.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/constMethod.hpp"
  33 #include "oops/fieldInfo.hpp"
  34 #include "oops/instanceKlassFlags.hpp"
  35 #include "oops/instanceOop.hpp"
  36 #include "runtime/handles.hpp"
  37 #include "runtime/javaThread.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/align.hpp"
  40 #include "utilities/growableArray.hpp"
  41 #include "utilities/macros.hpp"
  42 #if INCLUDE_JFR
  43 #include "jfr/support/jfrKlassExtension.hpp"
  44 #endif
  45 
  46 class ConstantPool;
  47 class DeoptimizationScope;
  48 class klassItable;
  49 class Monitor;
  50 class RecordComponent;
  51 
  52 // An InstanceKlass is the VM level representation of a Java class.
  53 // It contains all information needed for at class at execution runtime.
  54 
  55 //  InstanceKlass embedded field layout (after declared fields):
  56 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  57 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  58 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  59 //      indicating where oops are located in instances of this klass.
  60 //    [EMBEDDED implementor of the interface] only exist for interface
  61 //    [EMBEDDED InlineKlassFixedBlock] only if is an InlineKlass instance
  62 
  63 
  64 // forward declaration for class -- see below for definition
  65 #if INCLUDE_JVMTI
  66 class BreakpointInfo;
  67 #endif
  68 class ClassFileParser;
  69 class ClassFileStream;
  70 class KlassDepChange;
  71 class DependencyContext;
  72 class fieldDescriptor;
  73 class jniIdMapBase;
  74 class JNIid;
  75 class JvmtiCachedClassFieldMap;
  76 class nmethodBucket;
  77 class OopMapCache;
  78 class BufferedInlineTypeBlob;
  79 class InterpreterOopMap;
  80 class PackageEntry;
  81 class ModuleEntry;
  82 
  83 // This is used in iterators below.
  84 class FieldClosure: public StackObj {
  85 public:
  86   virtual void do_field(fieldDescriptor* fd) = 0;
  87 };
  88 
  89 // Print fields.
  90 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  91 class FieldPrinter: public FieldClosure {
  92    oop _obj;
  93    outputStream* _st;
  94  public:
  95    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  96    void do_field(fieldDescriptor* fd);
  97 };
  98 
  99 // Describes where oops are located in instances of this klass.
 100 class OopMapBlock {
 101  public:
 102   // Byte offset of the first oop mapped by this block.
 103   int offset() const          { return _offset; }
 104   void set_offset(int offset) { _offset = offset; }
 105 
 106   // Number of oops in this block.
 107   uint count() const         { return _count; }
 108   void set_count(uint count) { _count = count; }
 109 
 110   void increment_count(int diff) { _count += diff; }
 111 
 112   int offset_span() const { return _count * heapOopSize; }
 113 
 114   int end_offset() const {
 115     return offset() + offset_span();
 116   }
 117 
 118   bool is_contiguous(int another_offset) const {
 119     return another_offset == end_offset();
 120   }
 121 
 122   // sizeof(OopMapBlock) in words.
 123   static int size_in_words() {
 124     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 125       LogBytesPerWord;
 126   }
 127 
 128   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 129     return a->offset() - b->offset();
 130   }
 131 
 132  private:
 133   int  _offset;
 134   uint _count;
 135 };
 136 
 137 struct JvmtiCachedClassFileData;
 138 
 139 class SigEntry;
 140 
 141 class InlineKlassFixedBlock {
 142   Array<SigEntry>** _extended_sig;
 143   Array<VMRegPair>** _return_regs;
 144   address* _pack_handler;
 145   address* _pack_handler_jobject;
 146   address* _unpack_handler;
 147   int* _default_value_offset;
 148   int* _null_reset_value_offset;
 149   ArrayKlass** _null_free_inline_array_klasses;
 150   int _first_field_offset;
 151   int _payload_size_in_bytes;   // size of payload layout
 152   int _payload_alignment;       // alignment required for payload
 153   int _non_atomic_size_in_bytes; // size of null-free non-atomic flat layout
 154   int _non_atomic_alignment;    // alignment requirement for null-free non-atomic layout
 155   int _atomic_size_in_bytes;    // size and alignment requirement for a null-free atomic layout, -1 if no atomic flat layout is possible
 156   int _nullable_size_in_bytes;  // size and alignment requirement for a nullable layout (always atomic), -1 if no nullable flat layout is possible
 157   int _null_marker_offset;
 158 
 159   friend class InlineKlass;
 160 };
 161 
 162 class InlineLayoutInfo : public MetaspaceObj {
 163   InlineKlass* _klass;
 164   LayoutKind _kind;
 165   int _null_marker_offset; // null marker offset for this field, relative to the beginning of the current container
 166 
 167  public:
 168   InlineLayoutInfo(): _klass(nullptr), _kind(LayoutKind::UNKNOWN), _null_marker_offset(-1)  {}
 169   InlineLayoutInfo(InlineKlass* ik, LayoutKind kind, int size, int nm_offset):
 170     _klass(ik), _kind(kind), _null_marker_offset(nm_offset) {}
 171 
 172   InlineKlass* klass() const { return _klass; }
 173   void set_klass(InlineKlass* k) { _klass = k; }
 174 
 175   LayoutKind kind() const {
 176     assert(_kind != LayoutKind::UNKNOWN, "Not set");
 177     return _kind;
 178   }
 179   void set_kind(LayoutKind lk) { _kind = lk; }
 180 
 181   int null_marker_offset() const {
 182     assert(_null_marker_offset != -1, "Not set");
 183     return _null_marker_offset;
 184   }
 185   void set_null_marker_offset(int o) { _null_marker_offset = o; }
 186 
 187   void metaspace_pointers_do(MetaspaceClosure* it);
 188   MetaspaceObj::Type type() const { return InlineLayoutInfoType; }
 189 
 190   static ByteSize klass_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _klass)); }
 191   static ByteSize null_marker_offset_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _null_marker_offset)); }
 192 };
 193 
 194 class InstanceKlass: public Klass {
 195   friend class VMStructs;
 196   friend class JVMCIVMStructs;
 197   friend class ClassFileParser;
 198   friend class CompileReplay;
 199   friend class TemplateTable;
 200 
 201  public:
 202   static const KlassKind Kind = InstanceKlassKind;
 203 
 204  protected:
 205   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 206 
 207   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, bool use_class_space, TRAPS) throw();
 208 
 209  public:
 210   InstanceKlass();
 211 
 212   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 213   // of the class loading & initialization procedure, and the use of the states.
 214   enum ClassState : u1 {
 215     allocated,                          // allocated (but not yet linked)
 216     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 217     linked,                             // successfully linked/verified (but not initialized yet)
 218     being_initialized,                  // currently running class initializer
 219     fully_initialized,                  // initialized (successful final state)
 220     initialization_error                // error happened during initialization
 221   };
 222 
 223  private:
 224   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 225 
 226  protected:
 227   // If you add a new field that points to any metaspace object, you
 228   // must add this field to InstanceKlass::metaspace_pointers_do().
 229 
 230   // Annotations for this class
 231   Annotations*    _annotations;
 232   // Package this class is defined in
 233   PackageEntry*   _package_entry;
 234   // Array classes holding elements of this class.
 235   ArrayKlass* volatile _array_klasses;
 236   // Constant pool for this class.
 237   ConstantPool* _constants;
 238   // The InnerClasses attribute and EnclosingMethod attribute. The
 239   // _inner_classes is an array of shorts. If the class has InnerClasses
 240   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 241   // [inner_class_info_index, outer_class_info_index,
 242   // inner_name_index, inner_class_access_flags] for the InnerClasses
 243   // attribute. If the EnclosingMethod attribute exists, it occupies the
 244   // last two shorts [class_index, method_index] of the array. If only
 245   // the InnerClasses attribute exists, the _inner_classes array length is
 246   // number_of_inner_classes * 4. If the class has both InnerClasses
 247   // and EnclosingMethod attributes the _inner_classes array length is
 248   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 249   Array<jushort>* _inner_classes;
 250 
 251   // The NestMembers attribute. An array of shorts, where each is a
 252   // class info index for the class that is a nest member. This data
 253   // has not been validated.
 254   Array<jushort>* _nest_members;
 255 
 256   // Resolved nest-host klass: either true nest-host or self if we are not
 257   // nested, or an error occurred resolving or validating the nominated
 258   // nest-host. Can also be set directly by JDK API's that establish nest
 259   // relationships.
 260   // By always being set it makes nest-member access checks simpler.
 261   InstanceKlass* _nest_host;
 262 
 263   // The PermittedSubclasses attribute. An array of shorts, where each is a
 264   // class info index for the class that is a permitted subclass.
 265   Array<jushort>* _permitted_subclasses;
 266 
 267   // The contents of the Record attribute.
 268   Array<RecordComponent*>* _record_components;
 269 
 270   // the source debug extension for this klass, null if not specified.
 271   // Specified as UTF-8 string without terminating zero byte in the classfile,
 272   // it is stored in the instanceklass as a null-terminated UTF-8 string
 273   const char*     _source_debug_extension;
 274 
 275   // Number of heapOopSize words used by non-static fields in this klass
 276   // (including inherited fields but after header_size()).
 277   int             _nonstatic_field_size;
 278   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 279   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 280   int             _itable_len;              // length of Java itable (in words)
 281 
 282   // The NestHost attribute. The class info index for the class
 283   // that is the nest-host of this class. This data has not been validated.
 284   u2              _nest_host_index;
 285   u2              _this_class_index;        // constant pool entry
 286   u2              _static_oop_field_count;  // number of static oop fields in this klass
 287 
 288   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 289 
 290   // Class states are defined as ClassState (see above).
 291   // Place the _init_state here to utilize the unused 2-byte after
 292   // _idnum_allocated_count.
 293   volatile ClassState _init_state;          // state of class
 294 
 295   u1              _reference_type;                // reference type
 296 
 297   // State is set either at parse time or while executing, atomically to not disturb other state
 298   InstanceKlassFlags _misc_flags;
 299 
 300   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 301 
 302   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 303   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 304   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 305   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 306   uint64_t        volatile _dep_context_last_cleaned;
 307   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 308 #if INCLUDE_JVMTI
 309   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 310   // Linked instanceKlasses of previous versions
 311   InstanceKlass* _previous_versions;
 312   // JVMTI fields can be moved to their own structure - see 6315920
 313   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 314   JvmtiCachedClassFileData* _cached_class_file;
 315 #endif
 316 
 317 #if INCLUDE_JVMTI
 318   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 319 #endif
 320 
 321   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 322   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 323 
 324   // Method array.
 325   Array<Method*>* _methods;
 326   // Default Method Array, concrete methods inherited from interfaces
 327   Array<Method*>* _default_methods;
 328   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 329   Array<InstanceKlass*>* _local_interfaces;
 330   // Interfaces (InstanceKlass*s) this class implements transitively.
 331   Array<InstanceKlass*>* _transitive_interfaces;
 332   // Int array containing the original order of method in the class file (for JVMTI).
 333   Array<int>*     _method_ordering;
 334   // Int array containing the vtable_indices for default_methods
 335   // offset matches _default_methods offset
 336   Array<int>*     _default_vtable_indices;
 337 
 338   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 339   Array<u1>*          _fieldinfo_stream;
 340   Array<FieldStatus>* _fields_status;
 341 
 342   Array<InlineLayoutInfo>* _inline_layout_info_array;
 343   Array<u2>* _loadable_descriptors;
 344   const InlineKlassFixedBlock* _adr_inlineklass_fixed_block;
 345 
 346   // embedded Java vtable follows here
 347   // embedded Java itables follows here
 348   // embedded static fields follows here
 349   // embedded nonstatic oop-map blocks follows here
 350   // embedded implementor of this interface follows here
 351   //   The embedded implementor only exists if the current klass is an
 352   //   interface. The possible values of the implementor fall into following
 353   //   three cases:
 354   //     null: no implementor.
 355   //     A Klass* that's not itself: one implementor.
 356   //     Itself: more than one implementors.
 357   //
 358 
 359   friend class SystemDictionary;
 360 
 361   static bool _disable_method_binary_search;
 362 
 363   // Controls finalizer registration
 364   static bool _finalization_enabled;
 365 
 366  public:
 367 
 368   // Queries finalization state
 369   static bool is_finalization_enabled() { return _finalization_enabled; }
 370 
 371   // Sets finalization state
 372   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 373 
 374   // The three BUILTIN class loader types
 375   bool is_shared_boot_class() const { return _misc_flags.is_shared_boot_class(); }
 376   bool is_shared_platform_class() const { return _misc_flags.is_shared_platform_class(); }
 377   bool is_shared_app_class() const {  return _misc_flags.is_shared_app_class(); }
 378   // The UNREGISTERED class loader type
 379   bool is_shared_unregistered_class() const { return _misc_flags.is_shared_unregistered_class(); }
 380 
 381   // Check if the class can be shared in CDS
 382   bool is_shareable() const;
 383 
 384   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 385 
 386   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 387 
 388 #if INCLUDE_CDS
 389   void set_shared_class_loader_type(s2 loader_type) { _misc_flags.set_shared_class_loader_type(loader_type); }
 390   void assign_class_loader_type() { _misc_flags.assign_class_loader_type(_class_loader_data); }
 391 #endif
 392 
 393   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 394   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 395 
 396   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 397   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 398 
 399   bool has_inline_type_fields() const { return _misc_flags.has_inline_type_fields(); }
 400   void set_has_inline_type_fields()   { _misc_flags.set_has_inline_type_fields(true); }
 401 
 402   bool is_naturally_atomic() const  { return _misc_flags.is_naturally_atomic(); }
 403   void set_is_naturally_atomic()    { _misc_flags.set_is_naturally_atomic(true); }
 404 
 405   // Query if this class has atomicity requirements (default is yes)
 406   // This bit can occur anywhere, but is only significant
 407   // for inline classes *and* their super types.
 408   // It inherits from supers.
 409   // Its value depends on the ForceNonTearable VM option, the LooselyConsistentValue annotation
 410   // and the presence of flat fields with atomicity requirements
 411   bool must_be_atomic() const { return _misc_flags.must_be_atomic(); }
 412   void set_must_be_atomic()   { _misc_flags.set_must_be_atomic(true); }
 413 
 414   // Query if this class can be implicitly constructed, meaning the VM is allowed
 415   // to create instances without calling a constructor
 416   // Applies to inline classes and their super types
 417   bool is_implicitly_constructible() const { return _misc_flags.is_implicitly_constructible(); }
 418   void set_is_implicitly_constructible()   { _misc_flags.set_is_implicitly_constructible(true); }
 419 
 420   // field sizes
 421   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 422   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 423 
 424   int static_field_size() const            { return _static_field_size; }
 425   void set_static_field_size(int size)     { _static_field_size = size; }
 426 
 427   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 428   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 429 
 430   // Java itable
 431   int  itable_length() const               { return _itable_len; }
 432   void set_itable_length(int len)          { _itable_len = len; }
 433 
 434   // array klasses
 435   ArrayKlass* array_klasses() const     { return _array_klasses; }
 436   inline ArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 437   inline void release_set_array_klasses(ArrayKlass* k); // store with release semantics
 438   void set_array_klasses(ArrayKlass* k) { _array_klasses = k; }
 439 
 440   // methods
 441   Array<Method*>* methods() const          { return _methods; }
 442   void set_methods(Array<Method*>* a)      { _methods = a; }
 443   Method* method_with_idnum(int idnum);
 444   Method* method_with_orig_idnum(int idnum);
 445   Method* method_with_orig_idnum(int idnum, int version);
 446 
 447   // method ordering
 448   Array<int>* method_ordering() const     { return _method_ordering; }
 449   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 450   void copy_method_ordering(const intArray* m, TRAPS);
 451 
 452   // default_methods
 453   Array<Method*>* default_methods() const  { return _default_methods; }
 454   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 455 
 456   // default method vtable_indices
 457   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 458   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 459   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 460 
 461   // interfaces
 462   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 463   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 464     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 465     _local_interfaces = a; }
 466 
 467   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 468   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 469     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 470     _transitive_interfaces = a;
 471   }
 472 
 473  private:
 474   friend class fieldDescriptor;
 475   FieldInfo field(int index) const;
 476 
 477  public:
 478   int field_offset      (int index) const { return field(index).offset(); }
 479   int field_access_flags(int index) const { return field(index).access_flags().as_int(); }
 480   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 481   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 482   inline Symbol* field_name        (int index) const;
 483   inline Symbol* field_signature   (int index) const;
 484   bool field_is_flat(int index) const { return field_flags(index).is_flat(); }
 485   bool field_has_null_marker(int index) const { return field_flags(index).has_null_marker(); }
 486   bool field_is_null_free_inline_type(int index) const;
 487   bool is_class_in_loadable_descriptors_attribute(Symbol* name) const;
 488 
 489   int null_marker_offset(int index) const { return inline_layout_info(index).null_marker_offset(); }
 490 
 491   // Number of Java declared fields
 492   int java_fields_count() const;
 493   int total_fields_count() const;
 494 
 495   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 496   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 497 
 498   Array<FieldStatus>* fields_status() const {return _fields_status; }
 499   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 500 
 501   Array<u2>* loadable_descriptors() const { return _loadable_descriptors; }
 502   void set_loadable_descriptors(Array<u2>* c) { _loadable_descriptors = c; }
 503 
 504   // inner classes
 505   Array<u2>* inner_classes() const       { return _inner_classes; }
 506   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 507 
 508   // nest members
 509   Array<u2>* nest_members() const     { return _nest_members; }
 510   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 511 
 512   // nest-host index
 513   jushort nest_host_index() const { return _nest_host_index; }
 514   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 515   // dynamic nest member support
 516   void set_nest_host(InstanceKlass* host);
 517 
 518   // record components
 519   Array<RecordComponent*>* record_components() const { return _record_components; }
 520   void set_record_components(Array<RecordComponent*>* record_components) {
 521     _record_components = record_components;
 522   }
 523   bool is_record() const;
 524 
 525   // permitted subclasses
 526   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 527   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 528 
 529 private:
 530   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 531   // nor does it resolve any CP entries or load any classes.
 532   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 533 
 534 public:
 535   // Call this only if you know that the nest host has been initialized.
 536   InstanceKlass* nest_host_not_null() {
 537     assert(_nest_host != nullptr, "must be");
 538     return _nest_host;
 539   }
 540   // Used to construct informative IllegalAccessError messages at a higher level,
 541   // if there was an issue resolving or validating the nest host.
 542   // Returns null if there was no error.
 543   const char* nest_host_error();
 544   // Returns nest-host class, resolving and validating it if needed.
 545   // Returns null if resolution is not possible from the calling context.
 546   InstanceKlass* nest_host(TRAPS);
 547   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 548   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 549 
 550   // Called to verify that k is a permitted subclass of this class
 551   bool has_as_permitted_subclass(const InstanceKlass* k) const;
 552 
 553   enum InnerClassAttributeOffset {
 554     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 555     inner_class_inner_class_info_offset = 0,
 556     inner_class_outer_class_info_offset = 1,
 557     inner_class_inner_name_offset = 2,
 558     inner_class_access_flags_offset = 3,
 559     inner_class_next_offset = 4
 560   };
 561 
 562   enum EnclosingMethodAttributeOffset {
 563     enclosing_method_class_index_offset = 0,
 564     enclosing_method_method_index_offset = 1,
 565     enclosing_method_attribute_size = 2
 566   };
 567 
 568   // package
 569   PackageEntry* package() const     { return _package_entry; }
 570   ModuleEntry* module() const;
 571   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 572   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 573   // If the package for the InstanceKlass is in the boot loader's package entry
 574   // table then sets the classpath_index field so that
 575   // get_system_package() will know to return a non-null value for the
 576   // package's location.  And, so that the package will be added to the list of
 577   // packages returned by get_system_packages().
 578   // For packages whose classes are loaded from the boot loader class path, the
 579   // classpath_index indicates which entry on the boot loader class path.
 580   void set_classpath_index(s2 path_index);
 581   bool is_same_class_package(const Klass* class2) const;
 582   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 583 
 584   // find an enclosing class
 585   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 586 
 587   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 588   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 589 
 590  private:
 591   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 592   static void check_prohibited_package(Symbol* class_name,
 593                                        ClassLoaderData* loader_data,
 594                                        TRAPS);
 595 
 596   JavaThread* init_thread()  { return Atomic::load(&_init_thread); }
 597   const char* init_thread_name() {
 598     return init_thread()->name_raw();
 599   }
 600 
 601  public:
 602   // initialization state
 603   bool is_loaded() const                   { return init_state() >= loaded; }
 604   bool is_linked() const                   { return init_state() >= linked; }
 605   bool is_initialized() const              { return init_state() == fully_initialized; }
 606   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 607   bool is_being_initialized() const        { return init_state() == being_initialized; }
 608   bool is_in_error_state() const           { return init_state() == initialization_error; }
 609   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 610   ClassState  init_state() const           { return Atomic::load_acquire(&_init_state); }
 611   const char* init_state_name() const;
 612   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 613 
 614   // is this a sealed class
 615   bool is_sealed() const;
 616 
 617   // defineClass specified verification
 618   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 619   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 620 
 621   // marking
 622   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 623   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 624 
 625   static ByteSize kind_offset() { return in_ByteSize(offset_of(InstanceKlass, _kind)); }
 626   static ByteSize misc_flags_offset() { return in_ByteSize(offset_of(InstanceKlass, _misc_flags)); }
 627 
 628   // initialization (virtuals from Klass)
 629   bool should_be_initialized() const;  // means that initialize should be called
 630   void initialize(TRAPS);
 631   void link_class(TRAPS);
 632   bool link_class_or_fail(TRAPS); // returns false on failure
 633   void rewrite_class(TRAPS);
 634   void link_methods(TRAPS);
 635   Method* class_initializer() const;
 636 
 637   // reference type
 638   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 639 
 640   // this class cp index
 641   u2 this_class_index() const             { return _this_class_index; }
 642   void set_this_class_index(u2 index)     { _this_class_index = index; }
 643 
 644   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 645 
 646   // find local field, returns true if found
 647   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 648   // find field in direct superinterfaces, returns the interface in which the field is defined
 649   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 650   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 651   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 652   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 653   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 654 
 655   // find a non-static or static field given its offset within the class.
 656   bool contains_field_offset(int offset);
 657 
 658   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 659   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 660 
 661  private:
 662   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 663 
 664  public:
 665   static void disable_method_binary_search() {
 666     _disable_method_binary_search = true;
 667   }
 668 
 669   // find a local method (returns null if not found)
 670   Method* find_method(const Symbol* name, const Symbol* signature) const;
 671   static Method* find_method(const Array<Method*>* methods,
 672                              const Symbol* name,
 673                              const Symbol* signature);
 674 
 675   // find a local method, but skip static methods
 676   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 677                                PrivateLookupMode private_mode) const;
 678   static Method* find_instance_method(const Array<Method*>* methods,
 679                                       const Symbol* name,
 680                                       const Symbol* signature,
 681                                       PrivateLookupMode private_mode);
 682 
 683   // find a local method (returns null if not found)
 684   Method* find_local_method(const Symbol* name,
 685                             const Symbol* signature,
 686                             OverpassLookupMode overpass_mode,
 687                             StaticLookupMode static_mode,
 688                             PrivateLookupMode private_mode) const;
 689 
 690   // find a local method from given methods array (returns null if not found)
 691   static Method* find_local_method(const Array<Method*>* methods,
 692                                    const Symbol* name,
 693                                    const Symbol* signature,
 694                                    OverpassLookupMode overpass_mode,
 695                                    StaticLookupMode static_mode,
 696                                    PrivateLookupMode private_mode);
 697 
 698   // find a local method index in methods or default_methods (returns -1 if not found)
 699   static int find_method_index(const Array<Method*>* methods,
 700                                const Symbol* name,
 701                                const Symbol* signature,
 702                                OverpassLookupMode overpass_mode,
 703                                StaticLookupMode static_mode,
 704                                PrivateLookupMode private_mode);
 705 
 706   // lookup operation (returns null if not found)
 707   Method* uncached_lookup_method(const Symbol* name,
 708                                  const Symbol* signature,
 709                                  OverpassLookupMode overpass_mode,
 710                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 711 
 712   // lookup a method in all the interfaces that this class implements
 713   // (returns null if not found)
 714   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 715 
 716   // lookup a method in local defaults then in all interfaces
 717   // (returns null if not found)
 718   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 719 
 720   // Find method indices by name.  If a method with the specified name is
 721   // found the index to the first method is returned, and 'end' is filled in
 722   // with the index of first non-name-matching method.  If no method is found
 723   // -1 is returned.
 724   int find_method_by_name(const Symbol* name, int* end) const;
 725   static int find_method_by_name(const Array<Method*>* methods,
 726                                  const Symbol* name, int* end);
 727 
 728   // constant pool
 729   ConstantPool* constants() const        { return _constants; }
 730   void set_constants(ConstantPool* c)    { _constants = c; }
 731 
 732   // protection domain
 733   oop protection_domain() const;
 734 
 735   // signers
 736   objArrayOop signers() const;
 737 
 738   bool is_contended() const                { return _misc_flags.is_contended(); }
 739   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 740 
 741   // source file name
 742   Symbol* source_file_name() const;
 743   u2 source_file_name_index() const;
 744   void set_source_file_name_index(u2 sourcefile_index);
 745 
 746   // minor and major version numbers of class file
 747   u2 minor_version() const;
 748   void set_minor_version(u2 minor_version);
 749   u2 major_version() const;
 750   void set_major_version(u2 major_version);
 751 
 752   // source debug extension
 753   const char* source_debug_extension() const { return _source_debug_extension; }
 754   void set_source_debug_extension(const char* array, int length);
 755 
 756   // nonstatic oop-map blocks
 757   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 758     return oop_map_count * OopMapBlock::size_in_words();
 759   }
 760   unsigned int nonstatic_oop_map_count() const {
 761     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 762   }
 763   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 764   void set_nonstatic_oop_map_size(int words) {
 765     _nonstatic_oop_map_size = words;
 766   }
 767 
 768   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 769   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 770 
 771 #if INCLUDE_JVMTI
 772   // Redefinition locking.  Class can only be redefined by one thread at a time.
 773   // The flag is in access_flags so that it can be set and reset using atomic
 774   // operations, and not be reset by other misc_flag settings.
 775   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 776   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 777 
 778   // RedefineClasses() support for previous versions:
 779   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 780   void purge_previous_version_list();
 781 
 782   InstanceKlass* previous_versions() const { return _previous_versions; }
 783 #else
 784   InstanceKlass* previous_versions() const { return nullptr; }
 785 #endif
 786 
 787   InstanceKlass* get_klass_version(int version);
 788 
 789   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 790   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 791 
 792   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 793   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 794 
 795   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 796   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 797   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 798 
 799 public:
 800 #if INCLUDE_JVMTI
 801 
 802   void init_previous_versions() {
 803     _previous_versions = nullptr;
 804   }
 805 
 806  private:
 807   static bool  _should_clean_previous_versions;
 808  public:
 809   static void purge_previous_versions(InstanceKlass* ik) {
 810     if (ik->has_been_redefined()) {
 811       ik->purge_previous_version_list();
 812     }
 813   }
 814 
 815   static bool should_clean_previous_versions_and_reset();
 816   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 817 
 818   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 819   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 820     _cached_class_file = data;
 821   }
 822   JvmtiCachedClassFileData * get_cached_class_file();
 823   jint get_cached_class_file_len();
 824   unsigned char * get_cached_class_file_bytes();
 825 
 826   // JVMTI: Support for caching of field indices, types, and offsets
 827   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 828     _jvmti_cached_class_field_map = descriptor;
 829   }
 830   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 831     return _jvmti_cached_class_field_map;
 832   }
 833 #else // INCLUDE_JVMTI
 834 
 835   static void purge_previous_versions(InstanceKlass* ik) { return; };
 836   static bool should_clean_previous_versions_and_reset() { return false; }
 837 
 838   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 839     assert(data == nullptr, "unexpected call with JVMTI disabled");
 840   }
 841   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 842 
 843 #endif // INCLUDE_JVMTI
 844 
 845   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 846   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 847 
 848   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 849   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 850 
 851   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 852   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 853   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 854   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 855 
 856   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 857   inline u2 next_method_idnum();
 858   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 859 
 860   // generics support
 861   Symbol* generic_signature() const;
 862   u2 generic_signature_index() const;
 863   void set_generic_signature_index(u2 sig_index);
 864 
 865   u2 enclosing_method_data(int offset) const;
 866   u2 enclosing_method_class_index() const {
 867     return enclosing_method_data(enclosing_method_class_index_offset);
 868   }
 869   u2 enclosing_method_method_index() {
 870     return enclosing_method_data(enclosing_method_method_index_offset);
 871   }
 872   void set_enclosing_method_indices(u2 class_index,
 873                                     u2 method_index);
 874 
 875   // jmethodID support
 876   jmethodID get_jmethod_id(const methodHandle& method_h);
 877   void ensure_space_for_methodids(int start_offset = 0);
 878   jmethodID jmethod_id_or_null(Method* method);
 879   void update_methods_jmethod_cache();
 880 
 881   // annotations support
 882   Annotations* annotations() const          { return _annotations; }
 883   void set_annotations(Annotations* anno)   { _annotations = anno; }
 884 
 885   AnnotationArray* class_annotations() const {
 886     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 887   }
 888   Array<AnnotationArray*>* fields_annotations() const {
 889     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 890   }
 891   AnnotationArray* class_type_annotations() const {
 892     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 893   }
 894   Array<AnnotationArray*>* fields_type_annotations() const {
 895     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 896   }
 897   // allocation
 898   instanceOop allocate_instance(TRAPS);
 899   static instanceOop allocate_instance(oop cls, TRAPS);
 900 
 901   // additional member function to return a handle
 902   instanceHandle allocate_instance_handle(TRAPS);
 903 
 904   objArrayOop allocate_objArray(int n, int length, TRAPS);
 905   // Helper function
 906   static instanceOop register_finalizer(instanceOop i, TRAPS);
 907 
 908   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 909   // if not, throw either an Error or an Exception.
 910   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 911 
 912   // initialization
 913   void call_class_initializer(TRAPS);
 914   void set_initialization_state_and_notify(ClassState state, TRAPS);
 915 
 916   // OopMapCache support
 917   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 918   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 919   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 920 
 921   // JNI identifier support (for static fields - for jni performance)
 922   JNIid* jni_ids()                               { return _jni_ids; }
 923   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 924   JNIid* jni_id_for(int offset);
 925 
 926  public:
 927   // maintenance of deoptimization dependencies
 928   inline DependencyContext dependencies();
 929   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 930   void add_dependent_nmethod(nmethod* nm);
 931   void clean_dependency_context();
 932   // Setup link to hierarchy and deoptimize
 933   void add_to_hierarchy(JavaThread* current);
 934 
 935   // On-stack replacement support
 936   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 937   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 938   void add_osr_nmethod(nmethod* n);
 939   bool remove_osr_nmethod(nmethod* n);
 940   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 941   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 942 
 943 #if INCLUDE_JVMTI
 944   // Breakpoint support (see methods on Method* for details)
 945   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 946   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 947 #endif
 948 
 949   // support for stub routines
 950   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 951   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 952   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 953 
 954   static ByteSize inline_layout_info_array_offset() { return in_ByteSize(offset_of(InstanceKlass, _inline_layout_info_array)); }
 955   static ByteSize adr_inlineklass_fixed_block_offset() { return in_ByteSize(offset_of(InstanceKlass, _adr_inlineklass_fixed_block)); }
 956 
 957   // subclass/subinterface checks
 958   bool implements_interface(Klass* k) const;
 959   bool is_same_or_direct_interface(Klass* k) const;
 960 
 961 #ifdef ASSERT
 962   // check whether this class or one of its superclasses was redefined
 963   bool has_redefined_this_or_super() const;
 964 #endif
 965 
 966   // Access to the implementor of an interface.
 967   InstanceKlass* implementor() const;
 968   void set_implementor(InstanceKlass* ik);
 969   int  nof_implementors() const;
 970   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 971   void init_implementor();           // initialize
 972 
 973  private:
 974   // link this class into the implementors list of every interface it implements
 975   void process_interfaces();
 976 
 977  public:
 978   // virtual operations from Klass
 979   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 980                                                   Array<InstanceKlass*>* transitive_interfaces);
 981   bool can_be_primary_super_slow() const;
 982   size_t oop_size(oop obj)  const             { return size_helper(); }
 983   // slow because it's a virtual call and used for verifying the layout_helper.
 984   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 985   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 986 
 987   // Iterators
 988   void do_local_static_fields(FieldClosure* cl);
 989   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 990   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 991   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 992 
 993   void methods_do(void f(Method* method));
 994 
 995   static InstanceKlass* cast(Klass* k) {
 996     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 997   }
 998 
 999   static const InstanceKlass* cast(const Klass* k) {
1000     assert(k != nullptr, "k should not be null");
1001     assert(k->is_instance_klass(), "cast to InstanceKlass");
1002     return static_cast<const InstanceKlass*>(k);
1003   }
1004 
1005   virtual InstanceKlass* java_super() const {
1006     return (super() == nullptr) ? nullptr : cast(super());
1007   }
1008 
1009   // Sizing (in words)
1010   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
1011 
1012   static int size(int vtable_length, int itable_length,
1013                   int nonstatic_oop_map_size,
1014                   bool is_interface,
1015                   bool is_inline_type) {
1016     return align_metadata_size(header_size() +
1017            vtable_length +
1018            itable_length +
1019            nonstatic_oop_map_size +
1020            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
1021            (is_inline_type ? (int)sizeof(InlineKlassFixedBlock) : 0));
1022   }
1023 
1024   int size() const                    { return size(vtable_length(),
1025                                                itable_length(),
1026                                                nonstatic_oop_map_size(),
1027                                                is_interface(),
1028                                                is_inline_klass());
1029   }
1030 
1031 
1032   inline intptr_t* start_of_itable() const;
1033   inline intptr_t* end_of_itable() const;
1034   inline oop static_field_base_raw();
1035   bool bounds_check(address addr, bool edge_ok = false, intptr_t size_in_bytes = -1) const PRODUCT_RETURN0;
1036 
1037   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
1038   inline Klass** end_of_nonstatic_oop_maps() const;
1039 
1040   inline InstanceKlass* volatile* adr_implementor() const;
1041 
1042   void set_inline_layout_info_array(Array<InlineLayoutInfo>* array) { _inline_layout_info_array = array; }
1043   Array<InlineLayoutInfo>* inline_layout_info_array() const { return _inline_layout_info_array; }
1044   void set_inline_layout_info(int index, InlineLayoutInfo *info) {
1045     assert(_inline_layout_info_array != nullptr ,"Array not created");
1046     _inline_layout_info_array->at_put(index, *info);
1047   }
1048   InlineLayoutInfo inline_layout_info(int index) const {
1049     assert(_inline_layout_info_array != nullptr ,"Array not created");
1050     return _inline_layout_info_array->at(index);
1051   }
1052   InlineLayoutInfo* inline_layout_info_adr(int index) {
1053     assert(_inline_layout_info_array != nullptr ,"Array not created");
1054     return _inline_layout_info_array->adr_at(index);
1055   }
1056 
1057   inline InlineKlass* get_inline_type_field_klass(int idx) const ;
1058   inline InlineKlass* get_inline_type_field_klass_or_null(int idx) const;
1059 
1060   // Use this to return the size of an instance in heap words:
1061   virtual int size_helper() const {
1062     return layout_helper_to_size_helper(layout_helper());
1063   }
1064 
1065   // This bit is initialized in classFileParser.cpp.
1066   // It is false under any of the following conditions:
1067   //  - the class is abstract (including any interface)
1068   //  - the class size is larger than FastAllocateSizeLimit
1069   //  - the class is java/lang/Class, which cannot be allocated directly
1070   bool can_be_fastpath_allocated() const {
1071     return !layout_helper_needs_slow_path(layout_helper());
1072   }
1073 
1074   // Java itable
1075   klassItable itable() const;        // return klassItable wrapper
1076   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1077   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1078   int vtable_index_of_interface_method(Method* method);
1079 
1080 #if INCLUDE_JVMTI
1081   void adjust_default_methods(bool* trace_name_printed);
1082 #endif // INCLUDE_JVMTI
1083 
1084   void clean_weak_instanceklass_links();
1085  private:
1086   void clean_implementors_list();
1087   void clean_method_data();
1088 
1089  public:
1090   // Explicit metaspace deallocation of fields
1091   // For RedefineClasses and class file parsing errors, we need to deallocate
1092   // instanceKlasses and the metadata they point to.
1093   void deallocate_contents(ClassLoaderData* loader_data);
1094   static void deallocate_methods(ClassLoaderData* loader_data,
1095                                  Array<Method*>* methods);
1096   void static deallocate_interfaces(ClassLoaderData* loader_data,
1097                                     const Klass* super_klass,
1098                                     Array<InstanceKlass*>* local_interfaces,
1099                                     Array<InstanceKlass*>* transitive_interfaces);
1100   void static deallocate_record_components(ClassLoaderData* loader_data,
1101                                            Array<RecordComponent*>* record_component);
1102 
1103   virtual bool on_stack() const;
1104 
1105   // callbacks for actions during class unloading
1106   static void unload_class(InstanceKlass* ik);
1107 
1108   virtual void release_C_heap_structures(bool release_sub_metadata = true);
1109 
1110   // Naming
1111   const char* signature_name() const;
1112   const char* signature_name_of_carrier(char c) const;
1113 
1114   // Oop fields (and metadata) iterators
1115   //
1116   // The InstanceKlass iterators also visits the Object's klass.
1117 
1118   // Forward iteration
1119  public:
1120   // Iterate over all oop fields in the oop maps.
1121   template <typename T, class OopClosureType>
1122   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1123 
1124   // Iterate over all oop fields and metadata.
1125   template <typename T, class OopClosureType>
1126   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1127 
1128   // Iterate over all oop fields in one oop map.
1129   template <typename T, class OopClosureType>
1130   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1131 
1132 
1133   // Reverse iteration
1134   // Iterate over all oop fields and metadata.
1135   template <typename T, class OopClosureType>
1136   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1137 
1138  private:
1139   // Iterate over all oop fields in the oop maps.
1140   template <typename T, class OopClosureType>
1141   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1142 
1143   // Iterate over all oop fields in one oop map.
1144   template <typename T, class OopClosureType>
1145   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1146 
1147 
1148   // Bounded range iteration
1149  public:
1150   // Iterate over all oop fields in the oop maps.
1151   template <typename T, class OopClosureType>
1152   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1153 
1154   // Iterate over all oop fields and metadata.
1155   template <typename T, class OopClosureType>
1156   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1157 
1158  private:
1159   // Iterate over all oop fields in one oop map.
1160   template <typename T, class OopClosureType>
1161   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1162 
1163 
1164  public:
1165   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1166 
1167 private:
1168   // initialization state
1169   void set_init_state(ClassState state);
1170   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1171   void set_init_thread(JavaThread *thread)  {
1172     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1173            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1174     Atomic::store(&_init_thread, thread);
1175   }
1176 
1177   inline jmethodID* methods_jmethod_ids_acquire() const;
1178   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1179   // This nulls out jmethodIDs for all methods in 'klass'
1180   static void clear_jmethod_ids(InstanceKlass* klass);
1181   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1182 
1183 public:
1184   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1185   // Must be one per class and it has to be a VM internal object so java code
1186   // cannot lock it (like the mirror).
1187   // It has to be an object not a Mutex because it's held through java calls.
1188   oop init_lock() const;
1189 
1190   // Returns the array class for the n'th dimension
1191   virtual ArrayKlass* array_klass(int n, TRAPS);
1192   virtual ArrayKlass* array_klass_or_null(int n);
1193 
1194   // Returns the array class with this class as element type
1195   virtual ArrayKlass* array_klass(TRAPS);
1196   virtual ArrayKlass* array_klass_or_null();
1197 
1198   static void clean_initialization_error_table();
1199 private:
1200   void fence_and_clear_init_lock();
1201 
1202   bool link_class_impl                           (TRAPS);
1203   bool verify_code                               (TRAPS);
1204   void initialize_impl                           (TRAPS);
1205   void initialize_super_interfaces               (TRAPS);
1206 
1207   void add_initialization_error(JavaThread* current, Handle exception);
1208   oop get_initialization_error(JavaThread* current);
1209 
1210   // find a local method (returns null if not found)
1211   Method* find_method_impl(const Symbol* name,
1212                            const Symbol* signature,
1213                            OverpassLookupMode overpass_mode,
1214                            StaticLookupMode static_mode,
1215                            PrivateLookupMode private_mode) const;
1216 
1217   static Method* find_method_impl(const Array<Method*>* methods,
1218                                   const Symbol* name,
1219                                   const Symbol* signature,
1220                                   OverpassLookupMode overpass_mode,
1221                                   StaticLookupMode static_mode,
1222                                   PrivateLookupMode private_mode);
1223 
1224 #if INCLUDE_JVMTI
1225   // RedefineClasses support
1226   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1227   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1228 #endif
1229   // log class name to classlist
1230   void log_to_classlist() const;
1231 public:
1232 
1233 #if INCLUDE_CDS
1234   // CDS support - remove and restore oops from metadata. Oops are not shared.
1235   virtual void remove_unshareable_info();
1236   void remove_unshareable_flags();
1237   virtual void remove_java_mirror();
1238   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1239   void init_shared_package_entry();
1240   bool can_be_verified_at_dumptime() const;
1241   void compute_has_loops_flag_for_methods();
1242 #endif
1243 
1244   jint compute_modifier_flags() const;
1245 
1246 public:
1247   // JVMTI support
1248   jint jvmti_class_status() const;
1249 
1250   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1251 
1252  public:
1253   // Printing
1254   void print_on(outputStream* st) const;
1255   void print_value_on(outputStream* st) const;
1256 
1257   void oop_print_value_on(oop obj, outputStream* st);
1258 
1259   void oop_print_on      (oop obj, outputStream* st);
1260 
1261 #ifndef PRODUCT
1262   void print_dependent_nmethods(bool verbose = false);
1263   bool is_dependent_nmethod(nmethod* nm);
1264   bool verify_itable_index(int index);
1265 #endif
1266 
1267   const char* internal_name() const;
1268 
1269   // Verification
1270   void verify_on(outputStream* st);
1271 
1272   void oop_verify_on(oop obj, outputStream* st);
1273 
1274   // Logging
1275   void print_class_load_logging(ClassLoaderData* loader_data,
1276                                 const ModuleEntry* module_entry,
1277                                 const ClassFileStream* cfs) const;
1278  private:
1279   void print_class_load_cause_logging() const;
1280   void print_class_load_helper(ClassLoaderData* loader_data,
1281                                const ModuleEntry* module_entry,
1282                                const ClassFileStream* cfs) const;
1283 };
1284 
1285 // for adding methods
1286 // UNSET_IDNUM return means no more ids available
1287 inline u2 InstanceKlass::next_method_idnum() {
1288   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1289     return ConstMethod::UNSET_IDNUM; // no more ids available
1290   } else {
1291     return _idnum_allocated_count++;
1292   }
1293 }
1294 
1295 class PrintClassClosure : public KlassClosure {
1296 private:
1297   outputStream* _st;
1298   bool _verbose;
1299 public:
1300   PrintClassClosure(outputStream* st, bool verbose);
1301 
1302   void do_klass(Klass* k);
1303 };
1304 
1305 /* JNIid class for jfieldIDs only */
1306 class JNIid: public CHeapObj<mtClass> {
1307   friend class VMStructs;
1308  private:
1309   Klass*             _holder;
1310   JNIid*             _next;
1311   int                _offset;
1312 #ifdef ASSERT
1313   bool               _is_static_field_id;
1314 #endif
1315 
1316  public:
1317   // Accessors
1318   Klass* holder() const           { return _holder; }
1319   int offset() const              { return _offset; }
1320   JNIid* next()                   { return _next; }
1321   // Constructor
1322   JNIid(Klass* holder, int offset, JNIid* next);
1323   // Identifier lookup
1324   JNIid* find(int offset);
1325 
1326   bool find_local_field(fieldDescriptor* fd) {
1327     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1328   }
1329 
1330   static void deallocate(JNIid* id);
1331   // Debugging
1332 #ifdef ASSERT
1333   bool is_static_field_id() const { return _is_static_field_id; }
1334   void set_is_static_field_id()   { _is_static_field_id = true; }
1335 #endif
1336   void verify(Klass* holder);
1337 };
1338 
1339 // An iterator that's used to access the inner classes indices in the
1340 // InstanceKlass::_inner_classes array.
1341 class InnerClassesIterator : public StackObj {
1342  private:
1343   Array<jushort>* _inner_classes;
1344   int _length;
1345   int _idx;
1346  public:
1347 
1348   InnerClassesIterator(const InstanceKlass* k) {
1349     _inner_classes = k->inner_classes();
1350     if (k->inner_classes() != nullptr) {
1351       _length = _inner_classes->length();
1352       // The inner class array's length should be the multiple of
1353       // inner_class_next_offset if it only contains the InnerClasses
1354       // attribute data, or it should be
1355       // n*inner_class_next_offset+enclosing_method_attribute_size
1356       // if it also contains the EnclosingMethod data.
1357       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1358               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1359              "just checking");
1360       // Remove the enclosing_method portion if exists.
1361       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1362         _length -= InstanceKlass::enclosing_method_attribute_size;
1363       }
1364     } else {
1365       _length = 0;
1366     }
1367     _idx = 0;
1368   }
1369 
1370   int length() const {
1371     return _length;
1372   }
1373 
1374   void next() {
1375     _idx += InstanceKlass::inner_class_next_offset;
1376   }
1377 
1378   bool done() const {
1379     return (_idx >= _length);
1380   }
1381 
1382   u2 inner_class_info_index() const {
1383     return _inner_classes->at(
1384                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1385   }
1386 
1387   void set_inner_class_info_index(u2 index) {
1388     _inner_classes->at_put(
1389                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1390   }
1391 
1392   u2 outer_class_info_index() const {
1393     return _inner_classes->at(
1394                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1395   }
1396 
1397   void set_outer_class_info_index(u2 index) {
1398     _inner_classes->at_put(
1399                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1400   }
1401 
1402   u2 inner_name_index() const {
1403     return _inner_classes->at(
1404                _idx + InstanceKlass::inner_class_inner_name_offset);
1405   }
1406 
1407   void set_inner_name_index(u2 index) {
1408     _inner_classes->at_put(
1409                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1410   }
1411 
1412   u2 inner_access_flags() const {
1413     return _inner_classes->at(
1414                _idx + InstanceKlass::inner_class_access_flags_offset);
1415   }
1416 };
1417 
1418 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1419 // Usage:
1420 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1421 //    Klass* k = iter.klass();
1422 //    ...
1423 //  }
1424 class ClassHierarchyIterator : public StackObj {
1425  private:
1426   InstanceKlass* _root;
1427   Klass*         _current;
1428   bool           _visit_subclasses;
1429 
1430  public:
1431   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1432     assert(_root == _current, "required"); // initial state
1433   }
1434 
1435   bool done() {
1436     return (_current == nullptr);
1437   }
1438 
1439   // Make a step iterating over the class hierarchy under the root class.
1440   // Skips subclasses if requested.
1441   void next();
1442 
1443   Klass* klass() {
1444     assert(!done(), "sanity");
1445     return _current;
1446   }
1447 
1448   // Skip subclasses of the current class.
1449   void skip_subclasses() {
1450     _visit_subclasses = false;
1451   }
1452 };
1453 
1454 #endif // SHARE_OOPS_INSTANCEKLASS_HPP