1 /*
   2  * Copyright (c) 1997, 2014, 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/classLoaderData.hpp"
  29 #include "memory/referenceType.hpp"
  30 #include "oops/annotations.hpp"
  31 #include "oops/constMethod.hpp"
  32 #include "oops/fieldInfo.hpp"
  33 #include "oops/instanceOop.hpp"
  34 #include "oops/klassVtable.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/os.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/bitMap.inline.hpp"
  39 #include "utilities/macros.hpp"
  40 #include "trace/traceMacros.hpp"
  41 
  42 // An InstanceKlass is the VM level representation of a Java class.
  43 // It contains all information needed for at class at execution runtime.
  44 
  45 //  InstanceKlass embedded field layout (after declared fields):
  46 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  47 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  48 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  49 //      indicating where oops are located in instances of this klass.
  50 //    [EMBEDDED implementor of the interface] only exist for interface
  51 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  52 
  53 
  54 // forward declaration for class -- see below for definition
  55 class SuperTypeClosure;
  56 class JNIid;
  57 class jniIdMapBase;
  58 class BreakpointInfo;
  59 class fieldDescriptor;
  60 class DepChange;
  61 class nmethodBucket;
  62 class JvmtiCachedClassFieldMap;
  63 class MemberNameTable;
  64 
  65 // This is used in iterators below.
  66 class FieldClosure: public StackObj {
  67 public:
  68   virtual void do_field(fieldDescriptor* fd) = 0;
  69 };
  70 
  71 #ifndef PRODUCT
  72 // Print fields.
  73 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
  74 class FieldPrinter: public FieldClosure {
  75    oop _obj;
  76    outputStream* _st;
  77  public:
  78    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
  79    void do_field(fieldDescriptor* fd);
  80 };
  81 #endif  // !PRODUCT
  82 
  83 // ValueObjs embedded in klass. Describes where oops are located in instances of
  84 // this klass.
  85 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
  86  public:
  87   // Byte offset of the first oop mapped by this block.
  88   int offset() const          { return _offset; }
  89   void set_offset(int offset) { _offset = offset; }
  90 
  91   // Number of oops in this block.
  92   uint count() const         { return _count; }
  93   void set_count(uint count) { _count = count; }
  94 
  95   // sizeof(OopMapBlock) in HeapWords.
  96   static const int size_in_words() {
  97     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
  98       LogHeapWordSize;
  99   }
 100 
 101  private:
 102   int  _offset;
 103   uint _count;
 104 };
 105 
 106 struct JvmtiCachedClassFileData;
 107 
 108 class InstanceKlass: public Klass {
 109   friend class VMStructs;
 110   friend class ClassFileParser;
 111   friend class CompileReplay;
 112 
 113  protected:
 114   // Constructor
 115   InstanceKlass(int vtable_len,
 116                 int itable_len,
 117                 int static_field_size,
 118                 int nonstatic_oop_map_size,
 119                 ReferenceType rt,
 120                 AccessFlags access_flags,
 121                 bool is_anonymous);
 122  public:
 123   static InstanceKlass* allocate_instance_klass(
 124                                           ClassLoaderData* loader_data,
 125                                           int vtable_len,
 126                                           int itable_len,
 127                                           int static_field_size,
 128                                           int nonstatic_oop_map_size,
 129                                           ReferenceType rt,
 130                                           AccessFlags access_flags,
 131                                           Symbol* name,
 132                                           Klass* super_klass,
 133                                           bool is_anonymous,
 134                                           TRAPS);
 135 
 136   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
 137 
 138   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 139   // of the class loading & initialization procedure, and the use of the states.
 140   enum ClassState {
 141     allocated,                          // allocated (but not yet linked)
 142     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 143     linked,                             // successfully linked/verified (but not initialized yet)
 144     being_initialized,                  // currently running class initializer
 145     fully_initialized,                  // initialized (successfull final state)
 146     initialization_error                // error happened during initialization
 147   };
 148 
 149   static int number_of_instance_classes() { return _total_instanceKlass_count; }
 150 
 151  private:
 152   static volatile int _total_instanceKlass_count;
 153 
 154  protected:
 155   // Annotations for this class
 156   Annotations*    _annotations;
 157   // Array classes holding elements of this class.
 158   Klass*          _array_klasses;
 159   // Constant pool for this class.
 160   ConstantPool* _constants;
 161   // The InnerClasses attribute and EnclosingMethod attribute. The
 162   // _inner_classes is an array of shorts. If the class has InnerClasses
 163   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 164   // [inner_class_info_index, outer_class_info_index,
 165   // inner_name_index, inner_class_access_flags] for the InnerClasses
 166   // attribute. If the EnclosingMethod attribute exists, it occupies the
 167   // last two shorts [class_index, method_index] of the array. If only
 168   // the InnerClasses attribute exists, the _inner_classes array length is
 169   // number_of_inner_classes * 4. If the class has both InnerClasses
 170   // and EnclosingMethod attributes the _inner_classes array length is
 171   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 172   Array<jushort>* _inner_classes;
 173 
 174   // the source debug extension for this klass, NULL if not specified.
 175   // Specified as UTF-8 string without terminating zero byte in the classfile,
 176   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
 177   char*           _source_debug_extension;
 178   // Array name derived from this class which needs unreferencing
 179   // if this class is unloaded.
 180   Symbol*         _array_name;
 181 
 182   // Number of heapOopSize words used by non-static fields in this klass
 183   // (including inherited fields but after header_size()).
 184   int             _nonstatic_field_size;
 185   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 186   // Constant pool index to the utf8 entry of the Generic signature,
 187   // or 0 if none.
 188   u2              _generic_signature_index;
 189   // Constant pool index to the utf8 entry for the name of source file
 190   // containing this klass, 0 if not specified.
 191   u2              _source_file_name_index;
 192   u2              _static_oop_field_count;// number of static oop fields in this klass
 193   u2              _java_fields_count;    // The number of declared Java fields
 194   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 195 
 196   // _is_marked_dependent can be set concurrently, thus cannot be part of the
 197   // _misc_flags.
 198   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 199   bool            _has_unloaded_dependent;
 200 
 201   enum {
 202     _misc_rewritten            = 1 << 0, // methods rewritten.
 203     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
 204     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
 205     _misc_is_anonymous         = 1 << 3, // has embedded _host_klass field
 206     _misc_is_contended         = 1 << 4, // marked with contended annotation
 207     _misc_has_default_methods  = 1 << 5, // class/superclass/implemented interfaces has default methods
 208     _misc_has_been_redefined   = 1 << 6  // class has been redefined
 209   };
 210   u2              _misc_flags;
 211   u2              _minor_version;        // minor version number of class file
 212   u2              _major_version;        // major version number of class file
 213   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 214   int             _vtable_len;           // length of Java vtable (in words)
 215   int             _itable_len;           // length of Java itable (in words)
 216   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 217   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 218   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 219   nmethodBucket*  _dependencies;         // list of dependent nmethods
 220   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 221   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 222   // Linked instanceKlasses of previous versions
 223   InstanceKlass* _previous_versions;
 224   // JVMTI fields can be moved to their own structure - see 6315920
 225   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 226   JvmtiCachedClassFileData* _cached_class_file;
 227 
 228   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 229 
 230   // Class states are defined as ClassState (see above).
 231   // Place the _init_state here to utilize the unused 2-byte after
 232   // _idnum_allocated_count.
 233   u1              _init_state;                    // state of class
 234   u1              _reference_type;                // reference type
 235 
 236   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 237 
 238   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 239 
 240   // Method array.
 241   Array<Method*>* _methods;
 242   // Default Method Array, concrete methods inherited from interfaces
 243   Array<Method*>* _default_methods;
 244   // Interface (Klass*s) this class declares locally to implement.
 245   Array<Klass*>* _local_interfaces;
 246   // Interface (Klass*s) this class implements transitively.
 247   Array<Klass*>* _transitive_interfaces;
 248   // Int array containing the original order of method in the class file (for JVMTI).
 249   Array<int>*     _method_ordering;
 250   // Int array containing the vtable_indices for default_methods
 251   // offset matches _default_methods offset
 252   Array<int>*     _default_vtable_indices;
 253 
 254   // Instance and static variable information, starts with 6-tuples of shorts
 255   // [access, name index, sig index, initval index, low_offset, high_offset]
 256   // for all fields, followed by the generic signature data at the end of
 257   // the array. Only fields with generic signature attributes have the generic
 258   // signature data set in the array. The fields array looks like following:
 259   //
 260   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 261   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 262   //      ...
 263   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 264   //     [generic signature index]
 265   //     [generic signature index]
 266   //     ...
 267   Array<u2>*      _fields;
 268 
 269   // embedded Java vtable follows here
 270   // embedded Java itables follows here
 271   // embedded static fields follows here
 272   // embedded nonstatic oop-map blocks follows here
 273   // embedded implementor of this interface follows here
 274   //   The embedded implementor only exists if the current klass is an
 275   //   iterface. The possible values of the implementor fall into following
 276   //   three cases:
 277   //     NULL: no implementor.
 278   //     A Klass* that's not itself: one implementor.
 279   //     Itself: more than one implementors.
 280   // embedded host klass follows here
 281   //   The embedded host klass only exists in an anonymous class for
 282   //   dynamic language support (JSR 292 enabled). The host class grants
 283   //   its access privileges to this class also. The host class is either
 284   //   named, or a previously loaded anonymous class. A non-anonymous class
 285   //   or an anonymous class loaded through normal classloading does not
 286   //   have this embedded field.
 287   //
 288 
 289   friend class SystemDictionary;
 290 
 291  public:
 292   bool has_nonstatic_fields() const        {
 293     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 294   }
 295   void set_has_nonstatic_fields(bool b)    {
 296     if (b) {
 297       _misc_flags |= _misc_has_nonstatic_fields;
 298     } else {
 299       _misc_flags &= ~_misc_has_nonstatic_fields;
 300     }
 301   }
 302 
 303   // field sizes
 304   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 305   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 306 
 307   int static_field_size() const            { return _static_field_size; }
 308   void set_static_field_size(int size)     { _static_field_size = size; }
 309 
 310   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 311   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 312 
 313   // Java vtable
 314   int  vtable_length() const               { return _vtable_len; }
 315   void set_vtable_length(int len)          { _vtable_len = len; }
 316 
 317   // Java itable
 318   int  itable_length() const               { return _itable_len; }
 319   void set_itable_length(int len)          { _itable_len = len; }
 320 
 321   // array klasses
 322   Klass* array_klasses() const             { return _array_klasses; }
 323   void set_array_klasses(Klass* k)         { _array_klasses = k; }
 324 
 325   // methods
 326   Array<Method*>* methods() const          { return _methods; }
 327   void set_methods(Array<Method*>* a)      { _methods = a; }
 328   Method* method_with_idnum(int idnum);
 329 
 330   // method ordering
 331   Array<int>* method_ordering() const     { return _method_ordering; }
 332   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 333   void copy_method_ordering(intArray* m, TRAPS);
 334 
 335   // default_methods
 336   Array<Method*>* default_methods() const  { return _default_methods; }
 337   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 338 
 339   // default method vtable_indices
 340   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 341   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 342   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 343 
 344   // interfaces
 345   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
 346   void set_local_interfaces(Array<Klass*>* a)      {
 347     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
 348     _local_interfaces = a; }
 349 
 350   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 351   void set_transitive_interfaces(Array<Klass*>* a) {
 352     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
 353     _transitive_interfaces = a;
 354   }
 355 
 356  private:
 357   friend class fieldDescriptor;
 358   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 359 
 360  public:
 361   int     field_offset      (int index) const { return field(index)->offset(); }
 362   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 363   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 364   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 365 
 366   // Number of Java declared fields
 367   int java_fields_count() const           { return (int)_java_fields_count; }
 368 
 369   Array<u2>* fields() const            { return _fields; }
 370   void set_fields(Array<u2>* f, u2 java_fields_count) {
 371     guarantee(_fields == NULL || f == NULL, "Just checking");
 372     _fields = f;
 373     _java_fields_count = java_fields_count;
 374   }
 375 
 376   // inner classes
 377   Array<u2>* inner_classes() const       { return _inner_classes; }
 378   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 379 
 380   enum InnerClassAttributeOffset {
 381     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 382     inner_class_inner_class_info_offset = 0,
 383     inner_class_outer_class_info_offset = 1,
 384     inner_class_inner_name_offset = 2,
 385     inner_class_access_flags_offset = 3,
 386     inner_class_next_offset = 4
 387   };
 388 
 389   enum EnclosingMethodAttributeOffset {
 390     enclosing_method_class_index_offset = 0,
 391     enclosing_method_method_index_offset = 1,
 392     enclosing_method_attribute_size = 2
 393   };
 394 
 395   // method override check
 396   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 397 
 398   // package
 399   bool is_same_class_package(Klass* class2);
 400   bool is_same_class_package(oop classloader2, Symbol* classname2);
 401   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
 402 
 403   // find an enclosing class (defined where original code was, in jvm.cpp!)
 404   Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
 405     instanceKlassHandle self(THREAD, this);
 406     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
 407   }
 408   static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
 409                                                bool* inner_is_member, TRAPS);
 410 
 411   // tell if two classes have the same enclosing class (at package level)
 412   bool is_same_package_member(Klass* class2, TRAPS) {
 413     instanceKlassHandle self(THREAD, this);
 414     return is_same_package_member_impl(self, class2, THREAD);
 415   }
 416   static bool is_same_package_member_impl(instanceKlassHandle self,
 417                                           Klass* class2, TRAPS);
 418 
 419   // initialization state
 420   bool is_loaded() const                   { return _init_state >= loaded; }
 421   bool is_linked() const                   { return _init_state >= linked; }
 422   bool is_initialized() const              { return _init_state == fully_initialized; }
 423   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 424   bool is_being_initialized() const        { return _init_state == being_initialized; }
 425   bool is_in_error_state() const           { return _init_state == initialization_error; }
 426   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 427   ClassState  init_state()                 { return (ClassState)_init_state; }
 428   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 429 
 430   // defineClass specified verification
 431   bool should_verify_class() const         {
 432     return (_misc_flags & _misc_should_verify_class) != 0;
 433   }
 434   void set_should_verify_class(bool value) {
 435     if (value) {
 436       _misc_flags |= _misc_should_verify_class;
 437     } else {
 438       _misc_flags &= ~_misc_should_verify_class;
 439     }
 440   }
 441 
 442   // marking
 443   bool is_marked_dependent() const         { return _is_marked_dependent; }
 444   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 445 
 446   bool has_unloaded_dependent() const         { return _has_unloaded_dependent; }
 447   void set_has_unloaded_dependent(bool value) { _has_unloaded_dependent = value; }
 448 
 449   // initialization (virtuals from Klass)
 450   bool should_be_initialized() const;  // means that initialize should be called
 451   void initialize(TRAPS);
 452   void link_class(TRAPS);
 453   bool link_class_or_fail(TRAPS); // returns false on failure
 454   void unlink_class();
 455   void rewrite_class(TRAPS);
 456   void link_methods(TRAPS);
 457   Method* class_initializer();
 458 
 459   // set the class to initialized if no static initializer is present
 460   void eager_initialize(Thread *thread);
 461 
 462   // reference type
 463   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 464   void set_reference_type(ReferenceType t) {
 465     assert(t == (u1)t, "overflow");
 466     _reference_type = (u1)t;
 467   }
 468 
 469   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
 470 
 471   // find local field, returns true if found
 472   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 473   // find field in direct superinterfaces, returns the interface in which the field is defined
 474   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 475   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 476   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 477   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 478   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 479 
 480   // find a non-static or static field given its offset within the class.
 481   bool contains_field_offset(int offset) {
 482     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 483   }
 484 
 485   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 486   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 487 
 488   // find a local method (returns NULL if not found)
 489   Method* find_method(Symbol* name, Symbol* signature) const;
 490   static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 491   static Method* find_instance_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 492 
 493   // find a local method index in default_methods (returns -1 if not found)
 494   static int find_method_index(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass);
 495 
 496   // lookup operation (returns NULL if not found)
 497   Method* uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const;
 498 
 499   // lookup a method in all the interfaces that this class implements
 500   // (returns NULL if not found)
 501   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, MethodLookupMode mode) const;
 502 
 503   // lookup a method in local defaults then in all interfaces
 504   // (returns NULL if not found)
 505   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 506 
 507   // Find method indices by name.  If a method with the specified name is
 508   // found the index to the first method is returned, and 'end' is filled in
 509   // with the index of first non-name-matching method.  If no method is found
 510   // -1 is returned.
 511   int find_method_by_name(Symbol* name, int* end);
 512   static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
 513 
 514   // constant pool
 515   ConstantPool* constants() const        { return _constants; }
 516   void set_constants(ConstantPool* c)    { _constants = c; }
 517 
 518   // protection domain
 519   oop protection_domain() const;
 520 
 521   // signers
 522   objArrayOop signers() const;
 523 
 524   // host class
 525   Klass* host_klass() const              {
 526     Klass** hk = (Klass**)adr_host_klass();
 527     if (hk == NULL) {
 528       return NULL;
 529     } else {
 530       assert(*hk != NULL, "host klass should always be set if the address is not null");
 531       return *hk;
 532     }
 533   }
 534   void set_host_klass(Klass* host)            {
 535     assert(is_anonymous(), "not anonymous");
 536     Klass** addr = (Klass**)adr_host_klass();
 537     assert(addr != NULL, "no reversed space");
 538     if (addr != NULL) {
 539       *addr = host;
 540     }
 541   }
 542   bool is_anonymous() const                {
 543     return (_misc_flags & _misc_is_anonymous) != 0;
 544   }
 545   void set_is_anonymous(bool value)        {
 546     if (value) {
 547       _misc_flags |= _misc_is_anonymous;
 548     } else {
 549       _misc_flags &= ~_misc_is_anonymous;
 550     }
 551   }
 552 
 553   // Oop that keeps the metadata for this class from being unloaded
 554   // in places where the metadata is stored in other places, like nmethods
 555   oop klass_holder() const {
 556     return is_anonymous() ? java_mirror() : class_loader();
 557   }
 558 
 559   bool is_contended() const                {
 560     return (_misc_flags & _misc_is_contended) != 0;
 561   }
 562   void set_is_contended(bool value)        {
 563     if (value) {
 564       _misc_flags |= _misc_is_contended;
 565     } else {
 566       _misc_flags &= ~_misc_is_contended;
 567     }
 568   }
 569 
 570   // source file name
 571   Symbol* source_file_name() const               {
 572     return (_source_file_name_index == 0) ?
 573       (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
 574   }
 575   u2 source_file_name_index() const              {
 576     return _source_file_name_index;
 577   }
 578   void set_source_file_name_index(u2 sourcefile_index) {
 579     _source_file_name_index = sourcefile_index;
 580   }
 581 
 582   // minor and major version numbers of class file
 583   u2 minor_version() const                 { return _minor_version; }
 584   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 585   u2 major_version() const                 { return _major_version; }
 586   void set_major_version(u2 major_version) { _major_version = major_version; }
 587 
 588   // source debug extension
 589   char* source_debug_extension() const     { return _source_debug_extension; }
 590   void set_source_debug_extension(char* array, int length);
 591 
 592   // symbol unloading support (refcount already added)
 593   Symbol* array_name()                     { return _array_name; }
 594   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
 595 
 596   // nonstatic oop-map blocks
 597   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 598     return oop_map_count * OopMapBlock::size_in_words();
 599   }
 600   unsigned int nonstatic_oop_map_count() const {
 601     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 602   }
 603   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 604   void set_nonstatic_oop_map_size(int words) {
 605     _nonstatic_oop_map_size = words;
 606   }
 607 
 608   // RedefineClasses() support for previous versions:
 609   void add_previous_version(instanceKlassHandle ikh, int emcp_method_count);
 610 
 611   InstanceKlass* previous_versions() const { return _previous_versions; }
 612 
 613   bool has_been_redefined() const {
 614     return (_misc_flags & _misc_has_been_redefined) != 0;
 615   }
 616   void set_has_been_redefined() {
 617     _misc_flags |= _misc_has_been_redefined;
 618   }
 619 
 620   void init_previous_versions() {
 621     _previous_versions = NULL;
 622   }
 623 
 624   static void purge_previous_versions(InstanceKlass* ik);
 625 
 626   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 627   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 628     _cached_class_file = data;
 629   }
 630   JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
 631   jint get_cached_class_file_len();
 632   unsigned char * get_cached_class_file_bytes();
 633 
 634   // JVMTI: Support for caching of field indices, types, and offsets
 635   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 636     _jvmti_cached_class_field_map = descriptor;
 637   }
 638   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 639     return _jvmti_cached_class_field_map;
 640   }
 641 
 642   bool has_default_methods() const {
 643     return (_misc_flags & _misc_has_default_methods) != 0;
 644   }
 645   void set_has_default_methods(bool b) {
 646     if (b) {
 647       _misc_flags |= _misc_has_default_methods;
 648     } else {
 649       _misc_flags &= ~_misc_has_default_methods;
 650     }
 651   }
 652 
 653   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 654   inline u2 next_method_idnum();
 655   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 656 
 657   // generics support
 658   Symbol* generic_signature() const                   {
 659     return (_generic_signature_index == 0) ?
 660       (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
 661   }
 662   u2 generic_signature_index() const                  {
 663     return _generic_signature_index;
 664   }
 665   void set_generic_signature_index(u2 sig_index)      {
 666     _generic_signature_index = sig_index;
 667   }
 668 
 669   u2 enclosing_method_data(int offset);
 670   u2 enclosing_method_class_index() {
 671     return enclosing_method_data(enclosing_method_class_index_offset);
 672   }
 673   u2 enclosing_method_method_index() {
 674     return enclosing_method_data(enclosing_method_method_index_offset);
 675   }
 676   void set_enclosing_method_indices(u2 class_index,
 677                                     u2 method_index);
 678 
 679   // jmethodID support
 680   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
 681                      methodHandle method_h);
 682   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
 683                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
 684                      jmethodID* to_dealloc_id_p,
 685                      jmethodID** to_dealloc_jmeths_p);
 686   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 687                 size_t *length_p, jmethodID* id_p);
 688   jmethodID jmethod_id_or_null(Method* method);
 689 
 690   // annotations support
 691   Annotations* annotations() const          { return _annotations; }
 692   void set_annotations(Annotations* anno)   { _annotations = anno; }
 693 
 694   AnnotationArray* class_annotations() const {
 695     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
 696   }
 697   Array<AnnotationArray*>* fields_annotations() const {
 698     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
 699   }
 700   AnnotationArray* class_type_annotations() const {
 701     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
 702   }
 703   Array<AnnotationArray*>* fields_type_annotations() const {
 704     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
 705   }
 706   // allocation
 707   instanceOop allocate_instance(TRAPS);
 708 
 709   // additional member function to return a handle
 710   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 711 
 712   objArrayOop allocate_objArray(int n, int length, TRAPS);
 713   // Helper function
 714   static instanceOop register_finalizer(instanceOop i, TRAPS);
 715 
 716   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 717   // if not, throw either an Error or an Exception.
 718   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 719 
 720   // initialization
 721   void call_class_initializer(TRAPS);
 722   void set_initialization_state_and_notify(ClassState state, TRAPS);
 723 
 724   // OopMapCache support
 725   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 726   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 727   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
 728 
 729   // JNI identifier support (for static fields - for jni performance)
 730   JNIid* jni_ids()                               { return _jni_ids; }
 731   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 732   JNIid* jni_id_for(int offset);
 733 
 734   // maintenance of deoptimization dependencies
 735   int mark_dependent_nmethods(DepChange& changes);
 736   void add_dependent_nmethod(nmethod* nm);
 737   void remove_dependent_nmethod(nmethod* nm);
 738 
 739   // On-stack replacement support
 740   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 741   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 742   void add_osr_nmethod(nmethod* n);
 743   void remove_osr_nmethod(nmethod* n);
 744   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 745 
 746   // Breakpoint support (see methods on Method* for details)
 747   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 748   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 749 
 750   // support for stub routines
 751   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
 752   TRACE_DEFINE_OFFSET;
 753   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
 754 
 755   // subclass/subinterface checks
 756   bool implements_interface(Klass* k) const;
 757   bool is_same_or_direct_interface(Klass* k) const;
 758 
 759 #ifdef ASSERT
 760   // check whether this class or one of its superclasses was redefined
 761   bool has_redefined_this_or_super() const;
 762 #endif
 763 
 764   // Access to the implementor of an interface.
 765   Klass* implementor() const
 766   {
 767     Klass** k = adr_implementor();
 768     if (k == NULL) {
 769       return NULL;
 770     } else {
 771       return *k;
 772     }
 773   }
 774 
 775   void set_implementor(Klass* k) {
 776     assert(is_interface(), "not interface");
 777     Klass** addr = adr_implementor();
 778     assert(addr != NULL, "null addr");
 779     if (addr != NULL) {
 780       *addr = k;
 781     }
 782   }
 783 
 784   int  nof_implementors() const       {
 785     Klass* k = implementor();
 786     if (k == NULL) {
 787       return 0;
 788     } else if (k != this) {
 789       return 1;
 790     } else {
 791       return 2;
 792     }
 793   }
 794 
 795   void add_implementor(Klass* k);  // k is a new class that implements this interface
 796   void init_implementor();           // initialize
 797 
 798   // link this class into the implementors list of every interface it implements
 799   void process_interfaces(Thread *thread);
 800 
 801   // virtual operations from Klass
 802   bool is_leaf_class() const               { return _subklass == NULL; }
 803   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
 804   bool compute_is_subtype_of(Klass* k);
 805   bool can_be_primary_super_slow() const;
 806   int oop_size(oop obj)  const             { return size_helper(); }
 807   bool oop_is_instance_slow() const        { return true; }
 808 
 809   // Iterators
 810   void do_local_static_fields(FieldClosure* cl);
 811   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 812   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 813 
 814   void methods_do(void f(Method* method));
 815   void array_klasses_do(void f(Klass* k));
 816   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
 817   bool super_types_do(SuperTypeClosure* blk);
 818 
 819   // Casting from Klass*
 820   static InstanceKlass* cast(Klass* k) {
 821     assert(k == NULL || k->is_klass(), "must be");
 822     assert(k == NULL || k->oop_is_instance(), "cast to InstanceKlass");
 823     return (InstanceKlass*) k;
 824   }
 825 
 826   InstanceKlass* java_super() const {
 827     return (super() == NULL) ? NULL : cast(super());
 828   }
 829 
 830   // Sizing (in words)
 831   static int header_size()            { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
 832 
 833   static int size(int vtable_length, int itable_length,
 834                   int nonstatic_oop_map_size,
 835                   bool is_interface, bool is_anonymous) {
 836     return align_object_size(header_size() +
 837            align_object_offset(vtable_length) +
 838            align_object_offset(itable_length) +
 839            ((is_interface || is_anonymous) ?
 840              align_object_offset(nonstatic_oop_map_size) :
 841              nonstatic_oop_map_size) +
 842            (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
 843            (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
 844   }
 845   int size() const                    { return size(vtable_length(),
 846                                                itable_length(),
 847                                                nonstatic_oop_map_size(),
 848                                                is_interface(),
 849                                                is_anonymous());
 850   }
 851 #if INCLUDE_SERVICES
 852   virtual void collect_statistics(KlassSizeStats *sz) const;
 853 #endif
 854 
 855   static int vtable_start_offset()    { return header_size(); }
 856   static int vtable_length_offset()   { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
 857 
 858   intptr_t* start_of_vtable() const        { return ((intptr_t*)this) + vtable_start_offset(); }
 859   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
 860   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
 861 
 862   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
 863 
 864   address static_field_addr(int offset);
 865 
 866   OopMapBlock* start_of_nonstatic_oop_maps() const {
 867     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
 868   }
 869 
 870   Klass** end_of_nonstatic_oop_maps() const {
 871     return (Klass**)(start_of_nonstatic_oop_maps() +
 872                      nonstatic_oop_map_count());
 873   }
 874 
 875   Klass** adr_implementor() const {
 876     if (is_interface()) {
 877       return (Klass**)end_of_nonstatic_oop_maps();
 878     } else {
 879       return NULL;
 880     }
 881   };
 882 
 883   Klass** adr_host_klass() const {
 884     if (is_anonymous()) {
 885       Klass** adr_impl = adr_implementor();
 886       if (adr_impl != NULL) {
 887         return adr_impl + 1;
 888       } else {
 889         return end_of_nonstatic_oop_maps();
 890       }
 891     } else {
 892       return NULL;
 893     }
 894   }
 895 
 896   // Use this to return the size of an instance in heap words:
 897   int size_helper() const {
 898     return layout_helper_to_size_helper(layout_helper());
 899   }
 900 
 901   // This bit is initialized in classFileParser.cpp.
 902   // It is false under any of the following conditions:
 903   //  - the class is abstract (including any interface)
 904   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
 905   //  - the class size is larger than FastAllocateSizeLimit
 906   //  - the class is java/lang/Class, which cannot be allocated directly
 907   bool can_be_fastpath_allocated() const {
 908     return !layout_helper_needs_slow_path(layout_helper());
 909   }
 910 
 911   // Java vtable/itable
 912   klassVtable* vtable() const;        // return new klassVtable wrapper
 913   inline Method* method_at_vtable(int index);
 914   klassItable* itable() const;        // return new klassItable wrapper
 915   Method* method_at_itable(Klass* holder, int index, TRAPS);
 916 
 917 #if INCLUDE_JVMTI
 918   void adjust_default_methods(Method** old_methods, Method** new_methods,
 919                               int methods_length, bool* trace_name_printed);
 920   void adjust_member_name_table(Method** old_methods, Method** new_methods,
 921                                 int methods_length, bool* trace_name_printed);
 922 #endif // INCLUDE_JVMTI
 923 
 924   // Garbage collection
 925   void oop_follow_contents(oop obj);
 926   int  oop_adjust_pointers(oop obj);
 927 
 928   void clean_implementors_list(BoolObjectClosure* is_alive);
 929   void clean_method_data(BoolObjectClosure* is_alive);
 930   void clean_dependent_nmethods();
 931 
 932   // Explicit metaspace deallocation of fields
 933   // For RedefineClasses and class file parsing errors, we need to deallocate
 934   // instanceKlasses and the metadata they point to.
 935   void deallocate_contents(ClassLoaderData* loader_data);
 936   static void deallocate_methods(ClassLoaderData* loader_data,
 937                                  Array<Method*>* methods);
 938   void static deallocate_interfaces(ClassLoaderData* loader_data,
 939                                     Klass* super_klass,
 940                                     Array<Klass*>* local_interfaces,
 941                                     Array<Klass*>* transitive_interfaces);
 942 
 943   // The constant pool is on stack if any of the methods are executing or
 944   // referenced by handles.
 945   bool on_stack() const { return _constants->on_stack(); }
 946 
 947   // callbacks for actions during class unloading
 948   static void notify_unload_class(InstanceKlass* ik);
 949   static void release_C_heap_structures(InstanceKlass* ik);
 950 
 951   // Parallel Scavenge and Parallel Old
 952   PARALLEL_GC_DECLS
 953 
 954   // Naming
 955   const char* signature_name() const;
 956 
 957   // Iterators
 958   int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
 959     return oop_oop_iterate_v(obj, blk);
 960   }
 961 
 962   int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
 963     return oop_oop_iterate_v_m(obj, blk, mr);
 964   }
 965 
 966 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
 967   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
 968   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
 969                                       MemRegion mr);
 970 
 971   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
 972   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
 973 
 974 #if INCLUDE_ALL_GCS
 975 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
 976   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
 977 
 978   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 979   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 980 #endif // INCLUDE_ALL_GCS
 981 
 982   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
 983 
 984 public:
 985   void set_in_error_state() {
 986     assert(DumpSharedSpaces, "only call this when dumping archive");
 987     _init_state = initialization_error;
 988   }
 989   bool check_sharing_error_state();
 990 
 991 private:
 992   // initialization state
 993 #ifdef ASSERT
 994   void set_init_state(ClassState state);
 995 #else
 996   void set_init_state(ClassState state) { _init_state = (u1)state; }
 997 #endif
 998   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
 999   void set_init_thread(Thread *thread)  { _init_thread = thread; }
1000 
1001   // The RedefineClasses() API can cause new method idnums to be needed
1002   // which will cause the caches to grow. Safety requires different
1003   // cache management logic if the caches can grow instead of just
1004   // going from NULL to non-NULL.
1005   bool idnum_can_increment() const      { return has_been_redefined(); }
1006   jmethodID* methods_jmethod_ids_acquire() const
1007          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
1008   void release_set_methods_jmethod_ids(jmethodID* jmeths)
1009          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
1010 
1011   // Lock during initialization
1012 public:
1013   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1014   // Must be one per class and it has to be a VM internal object so java code
1015   // cannot lock it (like the mirror).
1016   // It has to be an object not a Mutex because it's held through java calls.
1017   oop init_lock() const;
1018 private:
1019   void fence_and_clear_init_lock();
1020 
1021   // Static methods that are used to implement member methods where an exposed this pointer
1022   // is needed due to possible GCs
1023   static bool link_class_impl                           (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1024   static bool verify_code                               (instanceKlassHandle this_k, bool throw_verifyerror, TRAPS);
1025   static void initialize_impl                           (instanceKlassHandle this_k, TRAPS);
1026   static void eager_initialize_impl                     (instanceKlassHandle this_k);
1027   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_k, ClassState state, TRAPS);
1028   static void call_class_initializer_impl               (instanceKlassHandle this_k, TRAPS);
1029   static Klass* array_klass_impl                        (instanceKlassHandle this_k, bool or_null, int n, TRAPS);
1030   static void do_local_static_fields_impl               (instanceKlassHandle this_k, void f(fieldDescriptor* fd, Handle, TRAPS), Handle, TRAPS);
1031   /* jni_id_for_impl for jfieldID only */
1032   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_k, int offset);
1033 
1034   // Returns the array class for the n'th dimension
1035   Klass* array_klass_impl(bool or_null, int n, TRAPS);
1036 
1037   // Returns the array class with this class as element type
1038   Klass* array_klass_impl(bool or_null, TRAPS);
1039 
1040   // find a local method (returns NULL if not found)
1041   Method* find_method_impl(Symbol* name, Symbol* signature, bool skipping_overpass) const;
1042   static Method* find_method_impl(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass);
1043 
1044   // Free CHeap allocated fields.
1045   void release_C_heap_structures();
1046 
1047   // RedefineClasses support
1048   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1049   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1050 public:
1051   // CDS support - remove and restore oops from metadata. Oops are not shared.
1052   virtual void remove_unshareable_info();
1053   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
1054 
1055   // jvm support
1056   jint compute_modifier_flags(TRAPS) const;
1057 
1058 public:
1059   // JVMTI support
1060   jint jvmti_class_status() const;
1061 
1062  public:
1063   // Printing
1064 #ifndef PRODUCT
1065   void print_on(outputStream* st) const;
1066 #endif
1067   void print_value_on(outputStream* st) const;
1068 
1069   void oop_print_value_on(oop obj, outputStream* st);
1070 
1071 #ifndef PRODUCT
1072   void oop_print_on      (oop obj, outputStream* st);
1073 
1074   void print_dependent_nmethods(bool verbose = false);
1075   bool is_dependent_nmethod(nmethod* nm);
1076 #endif
1077 
1078   const char* internal_name() const;
1079 
1080   // Verification
1081   void verify_on(outputStream* st);
1082 
1083   void oop_verify_on(oop obj, outputStream* st);
1084 };
1085 
1086 inline Method* InstanceKlass::method_at_vtable(int index)  {
1087 #ifndef PRODUCT
1088   assert(index >= 0, "valid vtable index");
1089   if (DebugVtables) {
1090     verify_vtable_index(index);
1091   }
1092 #endif
1093   vtableEntry* ve = (vtableEntry*)start_of_vtable();
1094   return ve[index].method();
1095 }
1096 
1097 // for adding methods
1098 // UNSET_IDNUM return means no more ids available
1099 inline u2 InstanceKlass::next_method_idnum() {
1100   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1101     return ConstMethod::UNSET_IDNUM; // no more ids available
1102   } else {
1103     return _idnum_allocated_count++;
1104   }
1105 }
1106 
1107 
1108 /* JNIid class for jfieldIDs only */
1109 class JNIid: public CHeapObj<mtClass> {
1110   friend class VMStructs;
1111  private:
1112   Klass*             _holder;
1113   JNIid*             _next;
1114   int                _offset;
1115 #ifdef ASSERT
1116   bool               _is_static_field_id;
1117 #endif
1118 
1119  public:
1120   // Accessors
1121   Klass* holder() const           { return _holder; }
1122   int offset() const              { return _offset; }
1123   JNIid* next()                   { return _next; }
1124   // Constructor
1125   JNIid(Klass* holder, int offset, JNIid* next);
1126   // Identifier lookup
1127   JNIid* find(int offset);
1128 
1129   bool find_local_field(fieldDescriptor* fd) {
1130     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1131   }
1132 
1133   static void deallocate(JNIid* id);
1134   // Debugging
1135 #ifdef ASSERT
1136   bool is_static_field_id() const { return _is_static_field_id; }
1137   void set_is_static_field_id()   { _is_static_field_id = true; }
1138 #endif
1139   void verify(Klass* holder);
1140 };
1141 
1142 
1143 //
1144 // nmethodBucket is used to record dependent nmethods for
1145 // deoptimization.  nmethod dependencies are actually <klass, method>
1146 // pairs but we really only care about the klass part for purposes of
1147 // finding nmethods which might need to be deoptimized.  Instead of
1148 // recording the method, a count of how many times a particular nmethod
1149 // was recorded is kept.  This ensures that any recording errors are
1150 // noticed since an nmethod should be removed as many times are it's
1151 // added.
1152 //
1153 class nmethodBucket: public CHeapObj<mtClass> {
1154   friend class VMStructs;
1155  private:
1156   nmethod*       _nmethod;
1157   int            _count;
1158   nmethodBucket* _next;
1159 
1160  public:
1161   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1162     _nmethod = nmethod;
1163     _next = next;
1164     _count = 1;
1165   }
1166   int count()                             { return _count; }
1167   int increment()                         { _count += 1; return _count; }
1168   int decrement();
1169   nmethodBucket* next()                   { return _next; }
1170   void set_next(nmethodBucket* b)         { _next = b; }
1171   nmethod* get_nmethod()                  { return _nmethod; }
1172 };
1173 
1174 // An iterator that's used to access the inner classes indices in the
1175 // InstanceKlass::_inner_classes array.
1176 class InnerClassesIterator : public StackObj {
1177  private:
1178   Array<jushort>* _inner_classes;
1179   int _length;
1180   int _idx;
1181  public:
1182 
1183   InnerClassesIterator(instanceKlassHandle k) {
1184     _inner_classes = k->inner_classes();
1185     if (k->inner_classes() != NULL) {
1186       _length = _inner_classes->length();
1187       // The inner class array's length should be the multiple of
1188       // inner_class_next_offset if it only contains the InnerClasses
1189       // attribute data, or it should be
1190       // n*inner_class_next_offset+enclosing_method_attribute_size
1191       // if it also contains the EnclosingMethod data.
1192       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1193               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1194              "just checking");
1195       // Remove the enclosing_method portion if exists.
1196       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1197         _length -= InstanceKlass::enclosing_method_attribute_size;
1198       }
1199     } else {
1200       _length = 0;
1201     }
1202     _idx = 0;
1203   }
1204 
1205   int length() const {
1206     return _length;
1207   }
1208 
1209   void next() {
1210     _idx += InstanceKlass::inner_class_next_offset;
1211   }
1212 
1213   bool done() const {
1214     return (_idx >= _length);
1215   }
1216 
1217   u2 inner_class_info_index() const {
1218     return _inner_classes->at(
1219                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1220   }
1221 
1222   void set_inner_class_info_index(u2 index) {
1223     _inner_classes->at_put(
1224                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1225   }
1226 
1227   u2 outer_class_info_index() const {
1228     return _inner_classes->at(
1229                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1230   }
1231 
1232   void set_outer_class_info_index(u2 index) {
1233     _inner_classes->at_put(
1234                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1235   }
1236 
1237   u2 inner_name_index() const {
1238     return _inner_classes->at(
1239                _idx + InstanceKlass::inner_class_inner_name_offset);
1240   }
1241 
1242   void set_inner_name_index(u2 index) {
1243     _inner_classes->at_put(
1244                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1245   }
1246 
1247   u2 inner_access_flags() const {
1248     return _inner_classes->at(
1249                _idx + InstanceKlass::inner_class_access_flags_offset);
1250   }
1251 };
1252 
1253 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP