1 /*
   2  * Copyright (c) 1997, 2017, 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_VM_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_VM_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/classLoaderData.hpp"
  30 #include "classfile/moduleEntry.hpp"
  31 #include "classfile/packageEntry.hpp"
  32 #include "gc/shared/specialized_oop_closures.hpp"
  33 #include "memory/referenceType.hpp"
  34 #include "oops/annotations.hpp"
  35 #include "oops/constMethod.hpp"
  36 #include "oops/fieldInfo.hpp"
  37 #include "oops/instanceOop.hpp"
  38 #include "oops/klassVtable.hpp"
  39 #include "runtime/handles.hpp"
  40 #include "runtime/os.hpp"
  41 #include "trace/traceMacros.hpp"
  42 #include "utilities/accessFlags.hpp"
  43 #include "utilities/align.hpp"
  44 #include "utilities/macros.hpp"
  45 
  46 // An InstanceKlass is the VM level representation of a Java class.
  47 // It contains all information needed for at class at execution runtime.
  48 
  49 //  InstanceKlass embedded field layout (after declared fields):
  50 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  51 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  52 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  53 //      indicating where oops are located in instances of this klass.
  54 //    [EMBEDDED implementor of the interface] only exist for interface
  55 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  56 //    [EMBEDDED fingerprint       ] only if should_store_fingerprint()==true
  57 
  58 
  59 // forward declaration for class -- see below for definition
  60 #if INCLUDE_JVMTI
  61 class BreakpointInfo;
  62 #endif
  63 class ClassFileParser;
  64 class KlassDepChange;
  65 class DependencyContext;
  66 class fieldDescriptor;
  67 class jniIdMapBase;
  68 class JNIid;
  69 class JvmtiCachedClassFieldMap;
  70 class SuperTypeClosure;
  71 
  72 // This is used in iterators below.
  73 class FieldClosure: public StackObj {
  74 public:
  75   virtual void do_field(fieldDescriptor* fd) = 0;
  76 };
  77 
  78 #ifndef PRODUCT
  79 // Print fields.
  80 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
  81 class FieldPrinter: public FieldClosure {
  82    oop _obj;
  83    outputStream* _st;
  84  public:
  85    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
  86    void do_field(fieldDescriptor* fd);
  87 };
  88 #endif  // !PRODUCT
  89 
  90 // ValueObjs embedded in klass. Describes where oops are located in instances of
  91 // this klass.
  92 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
  93  public:
  94   // Byte offset of the first oop mapped by this block.
  95   int offset() const          { return _offset; }
  96   void set_offset(int offset) { _offset = offset; }
  97 
  98   // Number of oops in this block.
  99   uint count() const         { return _count; }
 100   void set_count(uint count) { _count = count; }
 101 
 102   // sizeof(OopMapBlock) in words.
 103   static const int size_in_words() {
 104     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 105       LogBytesPerWord;
 106   }
 107 
 108  private:
 109   int  _offset;
 110   uint _count;
 111 };
 112 
 113 struct JvmtiCachedClassFileData;
 114 
 115 class InstanceKlass: public Klass {
 116   friend class VMStructs;
 117   friend class JVMCIVMStructs;
 118   friend class ClassFileParser;
 119   friend class CompileReplay;
 120 
 121  protected:
 122   InstanceKlass(const ClassFileParser& parser, unsigned kind);
 123 
 124  public:
 125   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 126 
 127   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 128   // of the class loading & initialization procedure, and the use of the states.
 129   enum ClassState {
 130     allocated,                          // allocated (but not yet linked)
 131     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 132     linked,                             // successfully linked/verified (but not initialized yet)
 133     being_initialized,                  // currently running class initializer
 134     fully_initialized,                  // initialized (successfull final state)
 135     initialization_error                // error happened during initialization
 136   };
 137 
 138   static int number_of_instance_classes() { return _total_instanceKlass_count; }
 139 
 140  private:
 141   static volatile int _total_instanceKlass_count;
 142   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 143 
 144  protected:
 145   // Annotations for this class
 146   Annotations*    _annotations;
 147   // Package this class is defined in
 148   PackageEntry*   _package_entry;
 149   // Array classes holding elements of this class.
 150   Klass* volatile _array_klasses;
 151   // Constant pool for this class.
 152   ConstantPool* _constants;
 153   // The InnerClasses attribute and EnclosingMethod attribute. The
 154   // _inner_classes is an array of shorts. If the class has InnerClasses
 155   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 156   // [inner_class_info_index, outer_class_info_index,
 157   // inner_name_index, inner_class_access_flags] for the InnerClasses
 158   // attribute. If the EnclosingMethod attribute exists, it occupies the
 159   // last two shorts [class_index, method_index] of the array. If only
 160   // the InnerClasses attribute exists, the _inner_classes array length is
 161   // number_of_inner_classes * 4. If the class has both InnerClasses
 162   // and EnclosingMethod attributes the _inner_classes array length is
 163   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 164   Array<jushort>* _inner_classes;
 165 
 166   // the source debug extension for this klass, NULL if not specified.
 167   // Specified as UTF-8 string without terminating zero byte in the classfile,
 168   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
 169   const char*     _source_debug_extension;
 170   // Array name derived from this class which needs unreferencing
 171   // if this class is unloaded.
 172   Symbol*         _array_name;
 173 
 174   // Number of heapOopSize words used by non-static fields in this klass
 175   // (including inherited fields but after header_size()).
 176   int             _nonstatic_field_size;
 177   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 178   // Constant pool index to the utf8 entry of the Generic signature,
 179   // or 0 if none.
 180   u2              _generic_signature_index;
 181   // Constant pool index to the utf8 entry for the name of source file
 182   // containing this klass, 0 if not specified.
 183   u2              _source_file_name_index;
 184   u2              _static_oop_field_count;// number of static oop fields in this klass
 185   u2              _java_fields_count;    // The number of declared Java fields
 186   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 187 
 188   int             _itable_len;           // length of Java itable (in words)
 189   // _is_marked_dependent can be set concurrently, thus cannot be part of the
 190   // _misc_flags.
 191   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 192   bool            _is_being_redefined;   // used for locking redefinition
 193 
 194   // The low two bits of _misc_flags contains the kind field.
 195   // This can be used to quickly discriminate among the four kinds of
 196   // InstanceKlass.
 197 
 198   static const unsigned _misc_kind_field_size = 2;
 199   static const unsigned _misc_kind_field_pos  = 0;
 200   static const unsigned _misc_kind_field_mask = (1u << _misc_kind_field_size) - 1u;
 201 
 202   static const unsigned _misc_kind_other        = 0; // concrete InstanceKlass
 203   static const unsigned _misc_kind_reference    = 1; // InstanceRefKlass
 204   static const unsigned _misc_kind_class_loader = 2; // InstanceClassLoaderKlass
 205   static const unsigned _misc_kind_mirror       = 3; // InstanceMirrorKlass
 206 
 207   // Start after _misc_kind field.
 208   enum {
 209     _misc_rewritten                           = 1 << 2,  // methods rewritten.
 210     _misc_has_nonstatic_fields                = 1 << 3,  // for sizing with UseCompressedOops
 211     _misc_should_verify_class                 = 1 << 4,  // allow caching of preverification
 212     _misc_is_anonymous                        = 1 << 5,  // has embedded _host_klass field
 213     _misc_is_contended                        = 1 << 6,  // marked with contended annotation
 214     _misc_has_nonstatic_concrete_methods      = 1 << 7,  // class/superclass/implemented interfaces has non-static, concrete methods
 215     _misc_declares_nonstatic_concrete_methods = 1 << 8,  // directly declares non-static, concrete methods
 216     _misc_has_been_redefined                  = 1 << 9,  // class has been redefined
 217     _misc_has_passed_fingerprint_check        = 1 << 10, // when this class was loaded, the fingerprint computed from its
 218                                                          // code source was found to be matching the value recorded by AOT.
 219     _misc_is_scratch_class                    = 1 << 11, // class is the redefined scratch class
 220     _misc_is_shared_boot_class                = 1 << 12, // defining class loader is boot class loader
 221     _misc_is_shared_platform_class            = 1 << 13, // defining class loader is platform class loader
 222     _misc_is_shared_app_class                 = 1 << 14, // defining class loader is app class loader
 223     _misc_has_resolved_methods                = 1 << 15  // resolved methods table entries added for this class
 224   };
 225   u2 loader_type_bits() {
 226     return _misc_is_shared_boot_class|_misc_is_shared_platform_class|_misc_is_shared_app_class;
 227   }
 228   u2              _misc_flags;
 229   u2              _minor_version;        // minor version number of class file
 230   u2              _major_version;        // major version number of class file
 231   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 232   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 233   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 234   jmethodID*      volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 235   intptr_t        _dep_context;          // packed DependencyContext structure
 236   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 237 #if INCLUDE_JVMTI
 238   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 239   // Linked instanceKlasses of previous versions
 240   InstanceKlass* _previous_versions;
 241   // JVMTI fields can be moved to their own structure - see 6315920
 242   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 243   JvmtiCachedClassFileData* _cached_class_file;
 244 #endif
 245 
 246   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 247 
 248   // Class states are defined as ClassState (see above).
 249   // Place the _init_state here to utilize the unused 2-byte after
 250   // _idnum_allocated_count.
 251   u1              _init_state;                    // state of class
 252   u1              _reference_type;                // reference type
 253 
 254 #if INCLUDE_JVMTI
 255   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 256 #endif
 257 
 258   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 259 
 260   // Method array.
 261   Array<Method*>* _methods;
 262   // Default Method Array, concrete methods inherited from interfaces
 263   Array<Method*>* _default_methods;
 264   // Interface (Klass*s) this class declares locally to implement.
 265   Array<Klass*>* _local_interfaces;
 266   // Interface (Klass*s) this class implements transitively.
 267   Array<Klass*>* _transitive_interfaces;
 268   // Int array containing the original order of method in the class file (for JVMTI).
 269   Array<int>*     _method_ordering;
 270   // Int array containing the vtable_indices for default_methods
 271   // offset matches _default_methods offset
 272   Array<int>*     _default_vtable_indices;
 273 
 274   // Instance and static variable information, starts with 6-tuples of shorts
 275   // [access, name index, sig index, initval index, low_offset, high_offset]
 276   // for all fields, followed by the generic signature data at the end of
 277   // the array. Only fields with generic signature attributes have the generic
 278   // signature data set in the array. The fields array looks like following:
 279   //
 280   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 281   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 282   //      ...
 283   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 284   //     [generic signature index]
 285   //     [generic signature index]
 286   //     ...
 287   Array<u2>*      _fields;
 288 
 289   // embedded Java vtable follows here
 290   // embedded Java itables follows here
 291   // embedded static fields follows here
 292   // embedded nonstatic oop-map blocks follows here
 293   // embedded implementor of this interface follows here
 294   //   The embedded implementor only exists if the current klass is an
 295   //   iterface. The possible values of the implementor fall into following
 296   //   three cases:
 297   //     NULL: no implementor.
 298   //     A Klass* that's not itself: one implementor.
 299   //     Itself: more than one implementors.
 300   // embedded host klass follows here
 301   //   The embedded host klass only exists in an anonymous class for
 302   //   dynamic language support (JSR 292 enabled). The host class grants
 303   //   its access privileges to this class also. The host class is either
 304   //   named, or a previously loaded anonymous class. A non-anonymous class
 305   //   or an anonymous class loaded through normal classloading does not
 306   //   have this embedded field.
 307   //
 308 
 309   friend class SystemDictionary;
 310 
 311  public:
 312   u2 loader_type() {
 313     return _misc_flags & loader_type_bits();
 314   }
 315 
 316   bool is_shared_boot_class() const {
 317     return (_misc_flags & _misc_is_shared_boot_class) != 0;
 318   }
 319   bool is_shared_platform_class() const {
 320     return (_misc_flags & _misc_is_shared_platform_class) != 0;
 321   }
 322   bool is_shared_app_class() const {
 323     return (_misc_flags & _misc_is_shared_app_class) != 0;
 324   }
 325 
 326   void set_class_loader_type(s2 loader_type) {
 327     assert(( _misc_flags & loader_type_bits()) == 0,
 328            "Should only be called once for each class.");
 329     switch (loader_type) {
 330     case ClassLoader::BOOT_LOADER:
 331       _misc_flags |= _misc_is_shared_boot_class;
 332        break;
 333     case ClassLoader::PLATFORM_LOADER:
 334       _misc_flags |= _misc_is_shared_platform_class;
 335       break;
 336     case ClassLoader::APP_LOADER:
 337       _misc_flags |= _misc_is_shared_app_class;
 338       break;
 339     default:
 340       ShouldNotReachHere();
 341       break;
 342     }
 343   }
 344 
 345   bool has_nonstatic_fields() const        {
 346     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 347   }
 348   void set_has_nonstatic_fields(bool b)    {
 349     if (b) {
 350       _misc_flags |= _misc_has_nonstatic_fields;
 351     } else {
 352       _misc_flags &= ~_misc_has_nonstatic_fields;
 353     }
 354   }
 355 
 356   // field sizes
 357   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 358   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 359 
 360   int static_field_size() const            { return _static_field_size; }
 361   void set_static_field_size(int size)     { _static_field_size = size; }
 362 
 363   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 364   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 365 
 366   // Java itable
 367   int  itable_length() const               { return _itable_len; }
 368   void set_itable_length(int len)          { _itable_len = len; }
 369 
 370   // array klasses
 371   Klass* array_klasses() const             { return _array_klasses; }
 372   inline Klass* array_klasses_acquire() const; // load with acquire semantics
 373   void set_array_klasses(Klass* k)         { _array_klasses = k; }
 374   inline void release_set_array_klasses(Klass* k); // store with release semantics
 375 
 376   // methods
 377   Array<Method*>* methods() const          { return _methods; }
 378   void set_methods(Array<Method*>* a)      { _methods = a; }
 379   Method* method_with_idnum(int idnum);
 380   Method* method_with_orig_idnum(int idnum);
 381   Method* method_with_orig_idnum(int idnum, int version);
 382 
 383   // method ordering
 384   Array<int>* method_ordering() const     { return _method_ordering; }
 385   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 386   void copy_method_ordering(const intArray* m, TRAPS);
 387 
 388   // default_methods
 389   Array<Method*>* default_methods() const  { return _default_methods; }
 390   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 391 
 392   // default method vtable_indices
 393   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 394   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 395   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 396 
 397   // interfaces
 398   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
 399   void set_local_interfaces(Array<Klass*>* a)      {
 400     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
 401     _local_interfaces = a; }
 402 
 403   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 404   void set_transitive_interfaces(Array<Klass*>* a) {
 405     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
 406     _transitive_interfaces = a;
 407   }
 408 
 409  private:
 410   friend class fieldDescriptor;
 411   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 412 
 413  public:
 414   int     field_offset      (int index) const { return field(index)->offset(); }
 415   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 416   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 417   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 418 
 419   // Number of Java declared fields
 420   int java_fields_count() const           { return (int)_java_fields_count; }
 421 
 422   Array<u2>* fields() const            { return _fields; }
 423   void set_fields(Array<u2>* f, u2 java_fields_count) {
 424     guarantee(_fields == NULL || f == NULL, "Just checking");
 425     _fields = f;
 426     _java_fields_count = java_fields_count;
 427   }
 428 
 429   // inner classes
 430   Array<u2>* inner_classes() const       { return _inner_classes; }
 431   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 432 
 433   enum InnerClassAttributeOffset {
 434     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 435     inner_class_inner_class_info_offset = 0,
 436     inner_class_outer_class_info_offset = 1,
 437     inner_class_inner_name_offset = 2,
 438     inner_class_access_flags_offset = 3,
 439     inner_class_next_offset = 4
 440   };
 441 
 442   enum EnclosingMethodAttributeOffset {
 443     enclosing_method_class_index_offset = 0,
 444     enclosing_method_method_index_offset = 1,
 445     enclosing_method_attribute_size = 2
 446   };
 447 
 448   // method override check
 449   bool is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 450 
 451   // package
 452   PackageEntry* package() const     { return _package_entry; }
 453   ModuleEntry* module() const;
 454   bool in_unnamed_package() const   { return (_package_entry == NULL); }
 455   void set_package(PackageEntry* p) { _package_entry = p; }
 456   void set_package(ClassLoaderData* loader_data, TRAPS);
 457   bool is_same_class_package(const Klass* class2) const;
 458   bool is_same_class_package(oop classloader2, const Symbol* classname2) const;
 459   static bool is_same_class_package(oop class_loader1,
 460                                     const Symbol* class_name1,
 461                                     oop class_loader2,
 462                                     const Symbol* class_name2);
 463 
 464   // find an enclosing class
 465   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 466 
 467   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 468   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 469 
 470  private:
 471   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 472   static void check_prohibited_package(Symbol* class_name,
 473                                        Handle class_loader,
 474                                        TRAPS);
 475  public:
 476   // tell if two classes have the same enclosing class (at package level)
 477   bool is_same_package_member(const Klass* class2, TRAPS) const;
 478 
 479   // initialization state
 480   bool is_loaded() const                   { return _init_state >= loaded; }
 481   bool is_linked() const                   { return _init_state >= linked; }
 482   bool is_initialized() const              { return _init_state == fully_initialized; }
 483   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 484   bool is_being_initialized() const        { return _init_state == being_initialized; }
 485   bool is_in_error_state() const           { return _init_state == initialization_error; }
 486   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 487   ClassState  init_state()                 { return (ClassState)_init_state; }
 488   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 489 
 490   // defineClass specified verification
 491   bool should_verify_class() const         {
 492     return (_misc_flags & _misc_should_verify_class) != 0;
 493   }
 494   void set_should_verify_class(bool value) {
 495     if (value) {
 496       _misc_flags |= _misc_should_verify_class;
 497     } else {
 498       _misc_flags &= ~_misc_should_verify_class;
 499     }
 500   }
 501 
 502   // marking
 503   bool is_marked_dependent() const         { return _is_marked_dependent; }
 504   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 505 
 506   // initialization (virtuals from Klass)
 507   bool should_be_initialized() const;  // means that initialize should be called
 508   void initialize(TRAPS);
 509   void link_class(TRAPS);
 510   bool link_class_or_fail(TRAPS); // returns false on failure
 511   void unlink_class();
 512   void rewrite_class(TRAPS);
 513   void link_methods(TRAPS);
 514   Method* class_initializer() const;
 515 
 516   // set the class to initialized if no static initializer is present
 517   void eager_initialize(Thread *thread);
 518 
 519   // reference type
 520   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 521   void set_reference_type(ReferenceType t) {
 522     assert(t == (u1)t, "overflow");
 523     _reference_type = (u1)t;
 524   }
 525 
 526   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
 527 
 528   // find local field, returns true if found
 529   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 530   // find field in direct superinterfaces, returns the interface in which the field is defined
 531   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 532   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 533   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 534   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 535   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 536 
 537   // find a non-static or static field given its offset within the class.
 538   bool contains_field_offset(int offset) {
 539     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 540   }
 541 
 542   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 543   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 544 
 545   // find a local method (returns NULL if not found)
 546   Method* find_method(const Symbol* name, const Symbol* signature) const;
 547   static Method* find_method(const Array<Method*>* methods,
 548                              const Symbol* name,
 549                              const Symbol* signature);
 550 
 551   // find a local method, but skip static methods
 552   Method* find_instance_method(const Symbol* name, const Symbol* signature) const;
 553   static Method* find_instance_method(const Array<Method*>* methods,
 554                                       const Symbol* name,
 555                                       const Symbol* signature);
 556 
 557   // find a local method (returns NULL if not found)
 558   Method* find_local_method(const Symbol* name,
 559                             const Symbol* signature,
 560                             OverpassLookupMode overpass_mode,
 561                             StaticLookupMode static_mode,
 562                             PrivateLookupMode private_mode) const;
 563 
 564   // find a local method from given methods array (returns NULL if not found)
 565   static Method* find_local_method(const Array<Method*>* methods,
 566                                    const Symbol* name,
 567                                    const Symbol* signature,
 568                                    OverpassLookupMode overpass_mode,
 569                                    StaticLookupMode static_mode,
 570                                    PrivateLookupMode private_mode);
 571 
 572   // find a local method index in methods or default_methods (returns -1 if not found)
 573   static int find_method_index(const Array<Method*>* methods,
 574                                const Symbol* name,
 575                                const Symbol* signature,
 576                                OverpassLookupMode overpass_mode,
 577                                StaticLookupMode static_mode,
 578                                PrivateLookupMode private_mode);
 579 
 580   // lookup operation (returns NULL if not found)
 581   Method* uncached_lookup_method(const Symbol* name,
 582                                  const Symbol* signature,
 583                                  OverpassLookupMode overpass_mode) const;
 584 
 585   // lookup a method in all the interfaces that this class implements
 586   // (returns NULL if not found)
 587   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 588 
 589   // lookup a method in local defaults then in all interfaces
 590   // (returns NULL if not found)
 591   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 592 
 593   // Find method indices by name.  If a method with the specified name is
 594   // found the index to the first method is returned, and 'end' is filled in
 595   // with the index of first non-name-matching method.  If no method is found
 596   // -1 is returned.
 597   int find_method_by_name(const Symbol* name, int* end) const;
 598   static int find_method_by_name(const Array<Method*>* methods,
 599                                  const Symbol* name, int* end);
 600 
 601   // constant pool
 602   ConstantPool* constants() const        { return _constants; }
 603   void set_constants(ConstantPool* c)    { _constants = c; }
 604 
 605   // protection domain
 606   oop protection_domain() const;
 607 
 608   // signers
 609   objArrayOop signers() const;
 610 
 611   // host class
 612   InstanceKlass* host_klass() const              {
 613     InstanceKlass** hk = adr_host_klass();
 614     if (hk == NULL) {
 615       return NULL;
 616     } else {
 617       assert(*hk != NULL, "host klass should always be set if the address is not null");
 618       return *hk;
 619     }
 620   }
 621   void set_host_klass(const InstanceKlass* host) {
 622     assert(is_anonymous(), "not anonymous");
 623     const InstanceKlass** addr = (const InstanceKlass **)adr_host_klass();
 624     assert(addr != NULL, "no reversed space");
 625     if (addr != NULL) {
 626       *addr = host;
 627     }
 628   }
 629   bool is_anonymous() const                {
 630     return (_misc_flags & _misc_is_anonymous) != 0;
 631   }
 632   void set_is_anonymous(bool value)        {
 633     if (value) {
 634       _misc_flags |= _misc_is_anonymous;
 635     } else {
 636       _misc_flags &= ~_misc_is_anonymous;
 637     }
 638   }
 639 
 640   // Oop that keeps the metadata for this class from being unloaded
 641   // in places where the metadata is stored in other places, like nmethods
 642   oop klass_holder() const {
 643     return is_anonymous() ? java_mirror() : class_loader();
 644   }
 645 
 646   bool is_contended() const                {
 647     return (_misc_flags & _misc_is_contended) != 0;
 648   }
 649   void set_is_contended(bool value)        {
 650     if (value) {
 651       _misc_flags |= _misc_is_contended;
 652     } else {
 653       _misc_flags &= ~_misc_is_contended;
 654     }
 655   }
 656 
 657   // source file name
 658   Symbol* source_file_name() const               {
 659     return (_source_file_name_index == 0) ?
 660       (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
 661   }
 662   u2 source_file_name_index() const              {
 663     return _source_file_name_index;
 664   }
 665   void set_source_file_name_index(u2 sourcefile_index) {
 666     _source_file_name_index = sourcefile_index;
 667   }
 668 
 669   // minor and major version numbers of class file
 670   u2 minor_version() const                 { return _minor_version; }
 671   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 672   u2 major_version() const                 { return _major_version; }
 673   void set_major_version(u2 major_version) { _major_version = major_version; }
 674 
 675   // source debug extension
 676   const char* source_debug_extension() const { return _source_debug_extension; }
 677   void set_source_debug_extension(const char* array, int length);
 678 
 679   // symbol unloading support (refcount already added)
 680   Symbol* array_name()                     { return _array_name; }
 681   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
 682 
 683   // nonstatic oop-map blocks
 684   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 685     return oop_map_count * OopMapBlock::size_in_words();
 686   }
 687   unsigned int nonstatic_oop_map_count() const {
 688     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 689   }
 690   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 691   void set_nonstatic_oop_map_size(int words) {
 692     _nonstatic_oop_map_size = words;
 693   }
 694 
 695 #if INCLUDE_JVMTI
 696   // Redefinition locking.  Class can only be redefined by one thread at a time.
 697   bool is_being_redefined() const          { return _is_being_redefined; }
 698   void set_is_being_redefined(bool value)  { _is_being_redefined = value; }
 699 
 700   // RedefineClasses() support for previous versions:
 701   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 702   void purge_previous_version_list();
 703 
 704   InstanceKlass* previous_versions() const { return _previous_versions; }
 705 #else
 706   InstanceKlass* previous_versions() const { return NULL; }
 707 #endif
 708 
 709   InstanceKlass* get_klass_version(int version) {
 710     for (InstanceKlass* ik = this; ik != NULL; ik = ik->previous_versions()) {
 711       if (ik->constants()->version() == version) {
 712         return ik;
 713       }
 714     }
 715     return NULL;
 716   }
 717 
 718   bool has_been_redefined() const {
 719     return (_misc_flags & _misc_has_been_redefined) != 0;
 720   }
 721   void set_has_been_redefined() {
 722     _misc_flags |= _misc_has_been_redefined;
 723   }
 724 
 725   bool has_passed_fingerprint_check() const {
 726     return (_misc_flags & _misc_has_passed_fingerprint_check) != 0;
 727   }
 728   void set_has_passed_fingerprint_check(bool b) {
 729     if (b) {
 730       _misc_flags |= _misc_has_passed_fingerprint_check;
 731     } else {
 732       _misc_flags &= ~_misc_has_passed_fingerprint_check;
 733     }
 734   }
 735   bool supers_have_passed_fingerprint_checks();
 736 
 737   static bool should_store_fingerprint();
 738   bool has_stored_fingerprint() const;
 739   uint64_t get_stored_fingerprint() const;
 740   void store_fingerprint(uint64_t fingerprint);
 741 
 742   bool is_scratch_class() const {
 743     return (_misc_flags & _misc_is_scratch_class) != 0;
 744   }
 745 
 746   void set_is_scratch_class() {
 747     _misc_flags |= _misc_is_scratch_class;
 748   }
 749 
 750   bool has_resolved_methods() const {
 751     return (_misc_flags & _misc_has_resolved_methods) != 0;
 752   }
 753 
 754   void set_has_resolved_methods() {
 755     _misc_flags |= _misc_has_resolved_methods;
 756   }
 757 private:
 758 
 759   void set_kind(unsigned kind) {
 760     assert(kind <= _misc_kind_field_mask, "Invalid InstanceKlass kind");
 761     unsigned fmask = _misc_kind_field_mask << _misc_kind_field_pos;
 762     unsigned flags = _misc_flags & ~fmask;
 763     _misc_flags = (flags | (kind << _misc_kind_field_pos));
 764   }
 765 
 766   bool is_kind(unsigned desired) const {
 767     unsigned kind = (_misc_flags >> _misc_kind_field_pos) & _misc_kind_field_mask;
 768     return kind == desired;
 769   }
 770 
 771 public:
 772 
 773   // Other is anything that is not one of the more specialized kinds of InstanceKlass.
 774   bool is_other_instance_klass() const        { return is_kind(_misc_kind_other); }
 775   bool is_reference_instance_klass() const    { return is_kind(_misc_kind_reference); }
 776   bool is_mirror_instance_klass() const       { return is_kind(_misc_kind_mirror); }
 777   bool is_class_loader_instance_klass() const { return is_kind(_misc_kind_class_loader); }
 778 
 779 #if INCLUDE_JVMTI
 780 
 781   void init_previous_versions() {
 782     _previous_versions = NULL;
 783   }
 784 
 785  private:
 786   static bool  _has_previous_versions;
 787  public:
 788   static void purge_previous_versions(InstanceKlass* ik) {
 789     if (ik->has_been_redefined()) {
 790       ik->purge_previous_version_list();
 791     }
 792   }
 793 
 794   static bool has_previous_versions_and_reset();
 795 
 796   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 797   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 798     _cached_class_file = data;
 799   }
 800   JvmtiCachedClassFileData * get_cached_class_file();
 801   jint get_cached_class_file_len();
 802   unsigned char * get_cached_class_file_bytes();
 803 
 804   // JVMTI: Support for caching of field indices, types, and offsets
 805   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 806     _jvmti_cached_class_field_map = descriptor;
 807   }
 808   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 809     return _jvmti_cached_class_field_map;
 810   }
 811 
 812 #if INCLUDE_CDS
 813   void set_archived_class_data(JvmtiCachedClassFileData* data) {
 814     _cached_class_file = data;
 815   }
 816 
 817   JvmtiCachedClassFileData * get_archived_class_data();
 818 #endif // INCLUDE_CDS
 819 #else // INCLUDE_JVMTI
 820 
 821   static void purge_previous_versions(InstanceKlass* ik) { return; };
 822   static bool has_previous_versions_and_reset() { return false; }
 823 
 824   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 825     assert(data == NULL, "unexpected call with JVMTI disabled");
 826   }
 827   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)NULL; }
 828 
 829 #endif // INCLUDE_JVMTI
 830 
 831   bool has_nonstatic_concrete_methods() const {
 832     return (_misc_flags & _misc_has_nonstatic_concrete_methods) != 0;
 833   }
 834   void set_has_nonstatic_concrete_methods(bool b) {
 835     if (b) {
 836       _misc_flags |= _misc_has_nonstatic_concrete_methods;
 837     } else {
 838       _misc_flags &= ~_misc_has_nonstatic_concrete_methods;
 839     }
 840   }
 841 
 842   bool declares_nonstatic_concrete_methods() const {
 843     return (_misc_flags & _misc_declares_nonstatic_concrete_methods) != 0;
 844   }
 845   void set_declares_nonstatic_concrete_methods(bool b) {
 846     if (b) {
 847       _misc_flags |= _misc_declares_nonstatic_concrete_methods;
 848     } else {
 849       _misc_flags &= ~_misc_declares_nonstatic_concrete_methods;
 850     }
 851   }
 852 
 853   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 854   inline u2 next_method_idnum();
 855   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 856 
 857   // generics support
 858   Symbol* generic_signature() const                   {
 859     return (_generic_signature_index == 0) ?
 860       (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
 861   }
 862   u2 generic_signature_index() const                  {
 863     return _generic_signature_index;
 864   }
 865   void set_generic_signature_index(u2 sig_index)      {
 866     _generic_signature_index = sig_index;
 867   }
 868 
 869   u2 enclosing_method_data(int offset) const;
 870   u2 enclosing_method_class_index() const {
 871     return enclosing_method_data(enclosing_method_class_index_offset);
 872   }
 873   u2 enclosing_method_method_index() {
 874     return enclosing_method_data(enclosing_method_method_index_offset);
 875   }
 876   void set_enclosing_method_indices(u2 class_index,
 877                                     u2 method_index);
 878 
 879   // jmethodID support
 880   jmethodID get_jmethod_id(const methodHandle& method_h);
 881   jmethodID get_jmethod_id_fetch_or_update(size_t idnum,
 882                      jmethodID new_id, jmethodID* new_jmeths,
 883                      jmethodID* to_dealloc_id_p,
 884                      jmethodID** to_dealloc_jmeths_p);
 885   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 886                 size_t *length_p, jmethodID* id_p);
 887   void ensure_space_for_methodids(int start_offset = 0);
 888   jmethodID jmethod_id_or_null(Method* method);
 889 
 890   // annotations support
 891   Annotations* annotations() const          { return _annotations; }
 892   void set_annotations(Annotations* anno)   { _annotations = anno; }
 893 
 894   AnnotationArray* class_annotations() const {
 895     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
 896   }
 897   Array<AnnotationArray*>* fields_annotations() const {
 898     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
 899   }
 900   AnnotationArray* class_type_annotations() const {
 901     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
 902   }
 903   Array<AnnotationArray*>* fields_type_annotations() const {
 904     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
 905   }
 906   // allocation
 907   instanceOop allocate_instance(TRAPS);
 908 
 909   // additional member function to return a handle
 910   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 911 
 912   objArrayOop allocate_objArray(int n, int length, TRAPS);
 913   // Helper function
 914   static instanceOop register_finalizer(instanceOop i, TRAPS);
 915 
 916   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 917   // if not, throw either an Error or an Exception.
 918   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 919 
 920   // initialization
 921   void call_class_initializer(TRAPS);
 922   void set_initialization_state_and_notify(ClassState state, TRAPS);
 923 
 924   // OopMapCache support
 925   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 926   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 927   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 928 
 929   // JNI identifier support (for static fields - for jni performance)
 930   JNIid* jni_ids()                               { return _jni_ids; }
 931   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 932   JNIid* jni_id_for(int offset);
 933 
 934   // maintenance of deoptimization dependencies
 935   inline DependencyContext dependencies();
 936   int  mark_dependent_nmethods(KlassDepChange& changes);
 937   void add_dependent_nmethod(nmethod* nm);
 938   void remove_dependent_nmethod(nmethod* nm, bool delete_immediately);
 939 
 940   // On-stack replacement support
 941   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 942   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 943   void add_osr_nmethod(nmethod* n);
 944   bool remove_osr_nmethod(nmethod* n);
 945   int mark_osr_nmethods(const Method* m);
 946   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 947 
 948 #if INCLUDE_JVMTI
 949   // Breakpoint support (see methods on Method* for details)
 950   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 951   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 952 #endif
 953 
 954   // support for stub routines
 955   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
 956   TRACE_DEFINE_KLASS_TRACE_ID_OFFSET;
 957   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
 958 
 959   // subclass/subinterface checks
 960   bool implements_interface(Klass* k) const;
 961   bool is_same_or_direct_interface(Klass* k) const;
 962 
 963 #ifdef ASSERT
 964   // check whether this class or one of its superclasses was redefined
 965   bool has_redefined_this_or_super() const;
 966 #endif
 967 
 968   // Access to the implementor of an interface.
 969   Klass* implementor() const
 970   {
 971     Klass** k = adr_implementor();
 972     if (k == NULL) {
 973       return NULL;
 974     } else {
 975       return *k;
 976     }
 977   }
 978 
 979   void set_implementor(Klass* k) {
 980     assert(is_interface(), "not interface");
 981     Klass** addr = adr_implementor();
 982     assert(addr != NULL, "null addr");
 983     if (addr != NULL) {
 984       *addr = k;
 985     }
 986   }
 987 
 988   int  nof_implementors() const       {
 989     Klass* k = implementor();
 990     if (k == NULL) {
 991       return 0;
 992     } else if (k != this) {
 993       return 1;
 994     } else {
 995       return 2;
 996     }
 997   }
 998 
 999   void add_implementor(Klass* k);  // k is a new class that implements this interface
1000   void init_implementor();           // initialize
1001 
1002   // link this class into the implementors list of every interface it implements
1003   void process_interfaces(Thread *thread);
1004 
1005   // virtual operations from Klass
1006   bool is_leaf_class() const               { return _subklass == NULL; }
1007   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
1008   bool compute_is_subtype_of(Klass* k);
1009   bool can_be_primary_super_slow() const;
1010   int oop_size(oop obj)  const             { return size_helper(); }
1011   // slow because it's a virtual call and used for verifying the layout_helper.
1012   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
1013   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
1014 
1015   // Iterators
1016   void do_local_static_fields(FieldClosure* cl);
1017   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
1018   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
1019 
1020   void methods_do(void f(Method* method));
1021   void array_klasses_do(void f(Klass* k));
1022   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
1023   bool super_types_do(SuperTypeClosure* blk);
1024 
1025   static InstanceKlass* cast(Klass* k) {
1026     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
1027   }
1028 
1029   static const InstanceKlass* cast(const Klass* k) {
1030     assert(k != NULL, "k should not be null");
1031     assert(k->is_instance_klass(), "cast to InstanceKlass");
1032     return static_cast<const InstanceKlass*>(k);
1033   }
1034 
1035   InstanceKlass* java_super() const {
1036     return (super() == NULL) ? NULL : cast(super());
1037   }
1038 
1039   // Sizing (in words)
1040   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
1041 
1042   static int size(int vtable_length, int itable_length,
1043                   int nonstatic_oop_map_size,
1044                   bool is_interface, bool is_anonymous, bool has_stored_fingerprint) {
1045     return align_metadata_size(header_size() +
1046            vtable_length +
1047            itable_length +
1048            nonstatic_oop_map_size +
1049            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
1050            (is_anonymous ? (int)sizeof(Klass*)/wordSize : 0) +
1051            (has_stored_fingerprint ? (int)sizeof(uint64_t*)/wordSize : 0));
1052   }
1053   int size() const                    { return size(vtable_length(),
1054                                                itable_length(),
1055                                                nonstatic_oop_map_size(),
1056                                                is_interface(),
1057                                                is_anonymous(),
1058                                                has_stored_fingerprint());
1059   }
1060 #if INCLUDE_SERVICES
1061   virtual void collect_statistics(KlassSizeStats *sz) const;
1062 #endif
1063 
1064   intptr_t* start_of_itable()   const { return (intptr_t*)start_of_vtable() + vtable_length(); }
1065   intptr_t* end_of_itable()     const { return start_of_itable() + itable_length(); }
1066 
1067   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
1068 
1069   address static_field_addr(int offset);
1070 
1071   OopMapBlock* start_of_nonstatic_oop_maps() const {
1072     return (OopMapBlock*)(start_of_itable() + itable_length());
1073   }
1074 
1075   Klass** end_of_nonstatic_oop_maps() const {
1076     return (Klass**)(start_of_nonstatic_oop_maps() +
1077                      nonstatic_oop_map_count());
1078   }
1079 
1080   Klass** adr_implementor() const {
1081     if (is_interface()) {
1082       return (Klass**)end_of_nonstatic_oop_maps();
1083     } else {
1084       return NULL;
1085     }
1086   };
1087 
1088   InstanceKlass** adr_host_klass() const {
1089     if (is_anonymous()) {
1090       InstanceKlass** adr_impl = (InstanceKlass **)adr_implementor();
1091       if (adr_impl != NULL) {
1092         return adr_impl + 1;
1093       } else {
1094         return (InstanceKlass **)end_of_nonstatic_oop_maps();
1095       }
1096     } else {
1097       return NULL;
1098     }
1099   }
1100 
1101   address adr_fingerprint() const {
1102     if (has_stored_fingerprint()) {
1103       InstanceKlass** adr_host = adr_host_klass();
1104       if (adr_host != NULL) {
1105         return (address)(adr_host + 1);
1106       }
1107 
1108       Klass** adr_impl = adr_implementor();
1109       if (adr_impl != NULL) {
1110         return (address)(adr_impl + 1);
1111       }
1112 
1113       return (address)end_of_nonstatic_oop_maps();
1114     } else {
1115       return NULL;
1116     }
1117   }
1118 
1119   // Use this to return the size of an instance in heap words:
1120   int size_helper() const {
1121     return layout_helper_to_size_helper(layout_helper());
1122   }
1123 
1124   // This bit is initialized in classFileParser.cpp.
1125   // It is false under any of the following conditions:
1126   //  - the class is abstract (including any interface)
1127   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
1128   //  - the class size is larger than FastAllocateSizeLimit
1129   //  - the class is java/lang/Class, which cannot be allocated directly
1130   bool can_be_fastpath_allocated() const {
1131     return !layout_helper_needs_slow_path(layout_helper());
1132   }
1133 
1134   // Java itable
1135   klassItable itable() const;        // return klassItable wrapper
1136   Method* method_at_itable(Klass* holder, int index, TRAPS);
1137 
1138 #if INCLUDE_JVMTI
1139   void adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed);
1140 #endif // INCLUDE_JVMTI
1141 
1142   void clean_weak_instanceklass_links(BoolObjectClosure* is_alive);
1143   void clean_implementors_list(BoolObjectClosure* is_alive);
1144   void clean_method_data(BoolObjectClosure* is_alive);
1145 
1146   // Explicit metaspace deallocation of fields
1147   // For RedefineClasses and class file parsing errors, we need to deallocate
1148   // instanceKlasses and the metadata they point to.
1149   void deallocate_contents(ClassLoaderData* loader_data);
1150   static void deallocate_methods(ClassLoaderData* loader_data,
1151                                  Array<Method*>* methods);
1152   void static deallocate_interfaces(ClassLoaderData* loader_data,
1153                                     const Klass* super_klass,
1154                                     Array<Klass*>* local_interfaces,
1155                                     Array<Klass*>* transitive_interfaces);
1156 
1157   // The constant pool is on stack if any of the methods are executing or
1158   // referenced by handles.
1159   bool on_stack() const { return _constants->on_stack(); }
1160 
1161   // callbacks for actions during class unloading
1162   static void notify_unload_class(InstanceKlass* ik);
1163   static void release_C_heap_structures(InstanceKlass* ik);
1164 
1165   // Naming
1166   const char* signature_name() const;
1167   static Symbol* package_from_name(const Symbol* name, TRAPS);
1168 
1169   // GC specific object visitors
1170   //
1171 #if INCLUDE_ALL_GCS
1172   // Parallel Scavenge
1173   void oop_ps_push_contents(  oop obj, PSPromotionManager* pm);
1174   // Parallel Compact
1175   void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
1176   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
1177 #endif
1178 
1179   // Oop fields (and metadata) iterators
1180   //  [nv = true]  Use non-virtual calls to do_oop_nv.
1181   //  [nv = false] Use virtual calls to do_oop.
1182   //
1183   // The InstanceKlass iterators also visits the Object's klass.
1184 
1185   // Forward iteration
1186  public:
1187   // Iterate over all oop fields in the oop maps.
1188   template <bool nv, class OopClosureType>
1189   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1190 
1191  protected:
1192   // Iterate over all oop fields and metadata.
1193   template <bool nv, class OopClosureType>
1194   inline int oop_oop_iterate(oop obj, OopClosureType* closure);
1195 
1196  private:
1197   // Iterate over all oop fields in the oop maps.
1198   // Specialized for [T = oop] or [T = narrowOop].
1199   template <bool nv, typename T, class OopClosureType>
1200   inline void oop_oop_iterate_oop_maps_specialized(oop obj, OopClosureType* closure);
1201 
1202   // Iterate over all oop fields in one oop map.
1203   template <bool nv, typename T, class OopClosureType>
1204   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1205 
1206 
1207   // Reverse iteration
1208 #if INCLUDE_ALL_GCS
1209  public:
1210   // Iterate over all oop fields in the oop maps.
1211   template <bool nv, class OopClosureType>
1212   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1213 
1214  protected:
1215   // Iterate over all oop fields and metadata.
1216   template <bool nv, class OopClosureType>
1217   inline int oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1218 
1219  private:
1220   // Iterate over all oop fields in the oop maps.
1221   // Specialized for [T = oop] or [T = narrowOop].
1222   template <bool nv, typename T, class OopClosureType>
1223   inline void oop_oop_iterate_oop_maps_specialized_reverse(oop obj, OopClosureType* closure);
1224 
1225   // Iterate over all oop fields in one oop map.
1226   template <bool nv, typename T, class OopClosureType>
1227   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1228 #endif
1229 
1230 
1231   // Bounded range iteration
1232  public:
1233   // Iterate over all oop fields in the oop maps.
1234   template <bool nv, class OopClosureType>
1235   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1236 
1237  protected:
1238   // Iterate over all oop fields and metadata.
1239   template <bool nv, class OopClosureType>
1240   inline int oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1241 
1242  private:
1243   // Iterate over all oop fields in the oop maps.
1244   // Specialized for [T = oop] or [T = narrowOop].
1245   template <bool nv, typename T, class OopClosureType>
1246   inline void oop_oop_iterate_oop_maps_specialized_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1247 
1248   // Iterate over all oop fields in one oop map.
1249   template <bool nv, typename T, class OopClosureType>
1250   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1251 
1252 
1253  public:
1254 
1255   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
1256   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
1257 
1258 #if INCLUDE_ALL_GCS
1259   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
1260   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
1261 #endif // INCLUDE_ALL_GCS
1262 
1263   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1264 
1265 public:
1266   void set_in_error_state() {
1267     assert(DumpSharedSpaces, "only call this when dumping archive");
1268     _init_state = initialization_error;
1269   }
1270   bool check_sharing_error_state();
1271 
1272 private:
1273   // initialization state
1274 #ifdef ASSERT
1275   void set_init_state(ClassState state);
1276 #else
1277   void set_init_state(ClassState state) { _init_state = (u1)state; }
1278 #endif
1279   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
1280   void set_init_thread(Thread *thread)  { _init_thread = thread; }
1281 
1282   // The RedefineClasses() API can cause new method idnums to be needed
1283   // which will cause the caches to grow. Safety requires different
1284   // cache management logic if the caches can grow instead of just
1285   // going from NULL to non-NULL.
1286   bool idnum_can_increment() const      { return has_been_redefined(); }
1287   inline jmethodID* methods_jmethod_ids_acquire() const;
1288   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1289 
1290   // Lock during initialization
1291 public:
1292   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1293   // Must be one per class and it has to be a VM internal object so java code
1294   // cannot lock it (like the mirror).
1295   // It has to be an object not a Mutex because it's held through java calls.
1296   oop init_lock() const;
1297 private:
1298   void fence_and_clear_init_lock();
1299 
1300   bool link_class_impl                           (bool throw_verifyerror, TRAPS);
1301   bool verify_code                               (bool throw_verifyerror, TRAPS);
1302   void initialize_impl                           (TRAPS);
1303   void initialize_super_interfaces               (TRAPS);
1304   void eager_initialize_impl                     ();
1305   /* jni_id_for_impl for jfieldID only */
1306   JNIid* jni_id_for_impl                         (int offset);
1307 
1308   // Returns the array class for the n'th dimension
1309   Klass* array_klass_impl(bool or_null, int n, TRAPS);
1310 
1311   // Returns the array class with this class as element type
1312   Klass* array_klass_impl(bool or_null, TRAPS);
1313 
1314   // find a local method (returns NULL if not found)
1315   Method* find_method_impl(const Symbol* name,
1316                            const Symbol* signature,
1317                            OverpassLookupMode overpass_mode,
1318                            StaticLookupMode static_mode,
1319                            PrivateLookupMode private_mode) const;
1320 
1321   static Method* find_method_impl(const Array<Method*>* methods,
1322                                   const Symbol* name,
1323                                   const Symbol* signature,
1324                                   OverpassLookupMode overpass_mode,
1325                                   StaticLookupMode static_mode,
1326                                   PrivateLookupMode private_mode);
1327 
1328   // Free CHeap allocated fields.
1329   void release_C_heap_structures();
1330 
1331 #if INCLUDE_JVMTI
1332   // RedefineClasses support
1333   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1334   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1335 #endif
1336 public:
1337   // CDS support - remove and restore oops from metadata. Oops are not shared.
1338   virtual void remove_unshareable_info();
1339   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
1340 
1341   // jvm support
1342   jint compute_modifier_flags(TRAPS) const;
1343 
1344 public:
1345   // JVMTI support
1346   jint jvmti_class_status() const;
1347 
1348  public:
1349   // Printing
1350 #ifndef PRODUCT
1351   void print_on(outputStream* st) const;
1352 #endif
1353   void print_value_on(outputStream* st) const;
1354 
1355   void oop_print_value_on(oop obj, outputStream* st);
1356 
1357 #ifndef PRODUCT
1358   void oop_print_on      (oop obj, outputStream* st);
1359 
1360   void print_dependent_nmethods(bool verbose = false);
1361   bool is_dependent_nmethod(nmethod* nm);
1362 #endif
1363 
1364   const char* internal_name() const;
1365 
1366   // Verification
1367   void verify_on(outputStream* st);
1368 
1369   void oop_verify_on(oop obj, outputStream* st);
1370 
1371   // Logging
1372   void print_class_load_logging(ClassLoaderData* loader_data,
1373                                 const char* module_name,
1374                                 const ClassFileStream* cfs) const;
1375 };
1376 
1377 // for adding methods
1378 // UNSET_IDNUM return means no more ids available
1379 inline u2 InstanceKlass::next_method_idnum() {
1380   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1381     return ConstMethod::UNSET_IDNUM; // no more ids available
1382   } else {
1383     return _idnum_allocated_count++;
1384   }
1385 }
1386 
1387 
1388 /* JNIid class for jfieldIDs only */
1389 class JNIid: public CHeapObj<mtClass> {
1390   friend class VMStructs;
1391  private:
1392   Klass*             _holder;
1393   JNIid*             _next;
1394   int                _offset;
1395 #ifdef ASSERT
1396   bool               _is_static_field_id;
1397 #endif
1398 
1399  public:
1400   // Accessors
1401   Klass* holder() const           { return _holder; }
1402   int offset() const              { return _offset; }
1403   JNIid* next()                   { return _next; }
1404   // Constructor
1405   JNIid(Klass* holder, int offset, JNIid* next);
1406   // Identifier lookup
1407   JNIid* find(int offset);
1408 
1409   bool find_local_field(fieldDescriptor* fd) {
1410     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1411   }
1412 
1413   static void deallocate(JNIid* id);
1414   // Debugging
1415 #ifdef ASSERT
1416   bool is_static_field_id() const { return _is_static_field_id; }
1417   void set_is_static_field_id()   { _is_static_field_id = true; }
1418 #endif
1419   void verify(Klass* holder);
1420 };
1421 
1422 // An iterator that's used to access the inner classes indices in the
1423 // InstanceKlass::_inner_classes array.
1424 class InnerClassesIterator : public StackObj {
1425  private:
1426   Array<jushort>* _inner_classes;
1427   int _length;
1428   int _idx;
1429  public:
1430 
1431   InnerClassesIterator(const InstanceKlass* k) {
1432     _inner_classes = k->inner_classes();
1433     if (k->inner_classes() != NULL) {
1434       _length = _inner_classes->length();
1435       // The inner class array's length should be the multiple of
1436       // inner_class_next_offset if it only contains the InnerClasses
1437       // attribute data, or it should be
1438       // n*inner_class_next_offset+enclosing_method_attribute_size
1439       // if it also contains the EnclosingMethod data.
1440       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1441               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1442              "just checking");
1443       // Remove the enclosing_method portion if exists.
1444       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1445         _length -= InstanceKlass::enclosing_method_attribute_size;
1446       }
1447     } else {
1448       _length = 0;
1449     }
1450     _idx = 0;
1451   }
1452 
1453   int length() const {
1454     return _length;
1455   }
1456 
1457   void next() {
1458     _idx += InstanceKlass::inner_class_next_offset;
1459   }
1460 
1461   bool done() const {
1462     return (_idx >= _length);
1463   }
1464 
1465   u2 inner_class_info_index() const {
1466     return _inner_classes->at(
1467                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1468   }
1469 
1470   void set_inner_class_info_index(u2 index) {
1471     _inner_classes->at_put(
1472                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1473   }
1474 
1475   u2 outer_class_info_index() const {
1476     return _inner_classes->at(
1477                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1478   }
1479 
1480   void set_outer_class_info_index(u2 index) {
1481     _inner_classes->at_put(
1482                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1483   }
1484 
1485   u2 inner_name_index() const {
1486     return _inner_classes->at(
1487                _idx + InstanceKlass::inner_class_inner_name_offset);
1488   }
1489 
1490   void set_inner_name_index(u2 index) {
1491     _inner_classes->at_put(
1492                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1493   }
1494 
1495   u2 inner_access_flags() const {
1496     return _inner_classes->at(
1497                _idx + InstanceKlass::inner_class_access_flags_offset);
1498   }
1499 };
1500 
1501 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP