1 /*
   2  * Copyright (c) 1997, 2012, 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 "oops/constMethodOop.hpp"
  29 #include "oops/constantPoolOop.hpp"
  30 #include "oops/fieldInfo.hpp"
  31 #include "oops/instanceOop.hpp"
  32 #include "oops/klassOop.hpp"
  33 #include "oops/klassVtable.hpp"
  34 #include "oops/objArrayOop.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/os.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/bitMap.inline.hpp"
  39 
  40 // An instanceKlass is the VM level representation of a Java class.
  41 // It contains all information needed for at class at execution runtime.
  42 
  43 //  instanceKlass layout:
  44 //    [header                     ] klassOop
  45 //    [klass pointer              ] klassOop
  46 //    [C++ vtbl pointer           ] Klass
  47 //    [subtype cache              ] Klass
  48 //    [instance size              ] Klass
  49 //    [java mirror                ] Klass
  50 //    [super                      ] Klass
  51 //    [access_flags               ] Klass
  52 //    [name                       ] Klass
  53 //    [first subklass             ] Klass
  54 //    [next sibling               ] Klass
  55 //    [array klasses              ]
  56 //    [methods                    ]
  57 //    [local interfaces           ]
  58 //    [transitive interfaces      ]
  59 //    [fields                     ]
  60 //    [constants                  ]
  61 //    [class loader               ]
  62 //    [protection domain          ]
  63 //    [signers                    ]
  64 //    [source file name           ]
  65 //    [inner classes              ]
  66 //    [static field size          ]
  67 //    [nonstatic field size       ]
  68 //    [static oop fields size     ]
  69 //    [nonstatic oop maps size    ]
  70 //    [has finalize method        ]
  71 //    [deoptimization mark bit    ]
  72 //    [initialization state       ]
  73 //    [initializing thread        ]
  74 //    [Java vtable length         ]
  75 //    [oop map cache (stack maps) ]
  76 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  77 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  78 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  79 //      indicating where oops are located in instances of this klass.
  80 //    [EMBEDDED implementor of the interface] only exist for interface
  81 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
  82 
  83 
  84 // forward declaration for class -- see below for definition
  85 class SuperTypeClosure;
  86 class JNIid;
  87 class jniIdMapBase;
  88 class BreakpointInfo;
  89 class fieldDescriptor;
  90 class DepChange;
  91 class nmethodBucket;
  92 class PreviousVersionNode;
  93 class JvmtiCachedClassFieldMap;
  94 
  95 // This is used in iterators below.
  96 class FieldClosure: public StackObj {
  97 public:
  98   virtual void do_field(fieldDescriptor* fd) = 0;
  99 };
 100 
 101 #ifndef PRODUCT
 102 // Print fields.
 103 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
 104 class FieldPrinter: public FieldClosure {
 105    oop _obj;
 106    outputStream* _st;
 107  public:
 108    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
 109    void do_field(fieldDescriptor* fd);
 110 };
 111 #endif  // !PRODUCT
 112 
 113 // ValueObjs embedded in klass. Describes where oops are located in instances of
 114 // this klass.
 115 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
 116  public:
 117   // Byte offset of the first oop mapped by this block.
 118   int offset() const          { return _offset; }
 119   void set_offset(int offset) { _offset = offset; }
 120 
 121   // Number of oops in this block.
 122   uint count() const         { return _count; }
 123   void set_count(uint count) { _count = count; }
 124 
 125   // sizeof(OopMapBlock) in HeapWords.
 126   static const int size_in_words() {
 127     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
 128       LogHeapWordSize;
 129   }
 130 
 131  private:
 132   int  _offset;
 133   uint _count;
 134 };
 135 
 136 class instanceKlass: public Klass {
 137   friend class VMStructs;
 138  public:
 139   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 140   // of the class loading & initialization procedure, and the use of the states.
 141   enum ClassState {
 142     unparsable_by_gc = 0,               // object is not yet parsable by gc. Value of _init_state at object allocation.
 143     allocated,                          // allocated (but not yet linked)
 144     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 145     linked,                             // successfully linked/verified (but not initialized yet)
 146     being_initialized,                  // currently running class initializer
 147     fully_initialized,                  // initialized (successfull final state)
 148     initialization_error                // error happened during initialization
 149   };
 150 
 151  public:
 152   oop* oop_block_beg() const { return adr_array_klasses(); }
 153   oop* oop_block_end() const { return adr_methods_default_annotations() + 1; }
 154 
 155  protected:
 156   //
 157   // The oop block.  See comment in klass.hpp before making changes.
 158   //
 159 
 160   // Array classes holding elements of this class.
 161   klassOop        _array_klasses;
 162   // Method array.
 163   objArrayOop     _methods;
 164   // Int array containing the original order of method in the class file (for
 165   // JVMTI).
 166   typeArrayOop    _method_ordering;
 167   // Interface (klassOops) this class declares locally to implement.
 168   objArrayOop     _local_interfaces;
 169   // Interface (klassOops) this class implements transitively.
 170   objArrayOop     _transitive_interfaces;
 171   // Instance and static variable information, starts with 6-tuples of shorts
 172   // [access, name index, sig index, initval index, low_offset, high_offset]
 173   // for all fields, followed by the generic signature data at the end of
 174   // the array. Only fields with generic signature attributes have the generic
 175   // signature data set in the array. The fields array looks like following:
 176   //
 177   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
 178   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
 179   //      ...
 180   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
 181   //     [generic signature index]
 182   //     [generic signature index]
 183   //     ...
 184   typeArrayOop    _fields;
 185   // Constant pool for this class.
 186   constantPoolOop _constants;
 187   // Class loader used to load this class, NULL if VM loader used.
 188   oop             _class_loader;
 189   // Protection domain.
 190   oop             _protection_domain;
 191   // Class signers.
 192   objArrayOop     _signers;
 193   // The InnerClasses attribute and EnclosingMethod attribute. The
 194   // _inner_classes is an array of shorts. If the class has InnerClasses
 195   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 196   // [inner_class_info_index, outer_class_info_index,
 197   // inner_name_index, inner_class_access_flags] for the InnerClasses
 198   // attribute. If the EnclosingMethod attribute exists, it occupies the
 199   // last two shorts [class_index, method_index] of the array. If only
 200   // the InnerClasses attribute exists, the _inner_classes array length is
 201   // number_of_inner_classes * 4. If the class has both InnerClasses
 202   // and EnclosingMethod attributes the _inner_classes array length is
 203   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 204   typeArrayOop    _inner_classes;
 205   // Annotations for this class, or null if none.
 206   typeArrayOop    _class_annotations;
 207   // Annotation objects (byte arrays) for fields, or null if no annotations.
 208   // Indices correspond to entries (not indices) in fields array.
 209   objArrayOop     _fields_annotations;
 210   // Annotation objects (byte arrays) for methods, or null if no annotations.
 211   // Index is the idnum, which is initially the same as the methods array index.
 212   objArrayOop     _methods_annotations;
 213   // Annotation objects (byte arrays) for methods' parameters, or null if no
 214   // such annotations.
 215   // Index is the idnum, which is initially the same as the methods array index.
 216   objArrayOop     _methods_parameter_annotations;
 217   // Annotation objects (byte arrays) for methods' default values, or null if no
 218   // such annotations.
 219   // Index is the idnum, which is initially the same as the methods array index.
 220   objArrayOop     _methods_default_annotations;
 221 
 222   //
 223   // End of the oop block.
 224   //
 225 
 226   // Name of source file containing this klass, NULL if not specified.
 227   Symbol*         _source_file_name;
 228   // the source debug extension for this klass, NULL if not specified.
 229   Symbol*         _source_debug_extension;
 230   // Generic signature, or null if none.
 231   Symbol*         _generic_signature;
 232   // Array name derived from this class which needs unreferencing
 233   // if this class is unloaded.
 234   Symbol*         _array_name;
 235 
 236   // Number of heapOopSize words used by non-static fields in this klass
 237   // (including inherited fields but after header_size()).
 238   int             _nonstatic_field_size;
 239   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
 240   u2              _static_oop_field_count;// number of static oop fields in this klass
 241   u2              _java_fields_count;    // The number of declared Java fields
 242   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
 243 
 244   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
 245   enum {
 246     _misc_rewritten            = 1 << 0, // methods rewritten.
 247     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
 248     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
 249     _misc_is_anonymous         = 1 << 3  // has embedded _inner_classes field
 250   };
 251   u2              _misc_flags;
 252   u2              _minor_version;        // minor version number of class file
 253   u2              _major_version;        // major version number of class file
 254   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
 255   int             _vtable_len;           // length of Java vtable (in words)
 256   int             _itable_len;           // length of Java itable (in words)
 257   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 258   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
 259   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
 260   int*            _methods_cached_itable_indices;  // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
 261   nmethodBucket*  _dependencies;         // list of dependent nmethods
 262   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 263   BreakpointInfo* _breakpoints;          // bpt lists, managed by methodOop
 264   // Array of interesting part(s) of the previous version(s) of this
 265   // instanceKlass. See PreviousVersionWalker below.
 266   GrowableArray<PreviousVersionNode *>* _previous_versions;
 267   // JVMTI fields can be moved to their own structure - see 6315920
 268   unsigned char * _cached_class_file_bytes;       // JVMTI: cached class file, before retransformable agent modified it in CFLH
 269   jint            _cached_class_file_len;         // JVMTI: length of above
 270   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 271   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
 272 
 273   // Class states are defined as ClassState (see above).
 274   // Place the _init_state here to utilize the unused 2-byte after
 275   // _idnum_allocated_count.
 276   u1              _init_state;                    // state of class
 277 
 278   u1              _reference_type;                // reference type
 279 
 280   // embedded Java vtable follows here
 281   // embedded Java itables follows here
 282   // embedded static fields follows here
 283   // embedded nonstatic oop-map blocks follows here
 284   // embedded implementor of this interface follows here
 285   //   The embedded implementor only exists if the current klass is an
 286   //   iterface. The possible values of the implementor fall into following
 287   //   three cases:
 288   //     NULL: no implementor.
 289   //     A klassOop that's not itself: one implementor.
 290   //     Itsef: more than one implementors.
 291   // embedded host klass follows here
 292   //   The embedded host klass only exists in an anonymous class for
 293   //   dynamic language support (JSR 292 enabled). The host class grants
 294   //   its access privileges to this class also. The host class is either
 295   //   named, or a previously loaded anonymous class. A non-anonymous class
 296   //   or an anonymous class loaded through normal classloading does not
 297   //   have this embedded field.
 298   //
 299 
 300   friend class instanceKlassKlass;
 301   friend class SystemDictionary;
 302 
 303  public:
 304   bool has_nonstatic_fields() const        {
 305     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
 306   }
 307   void set_has_nonstatic_fields(bool b)    {
 308     if (b) {
 309       _misc_flags |= _misc_has_nonstatic_fields;
 310     } else {
 311       _misc_flags &= ~_misc_has_nonstatic_fields;
 312     }
 313   }
 314 
 315   // field sizes
 316   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 317   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 318 
 319   int static_field_size() const            { return _static_field_size; }
 320   void set_static_field_size(int size)     { _static_field_size = size; }
 321 
 322   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 323   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 324 
 325   // Java vtable
 326   int  vtable_length() const               { return _vtable_len; }
 327   void set_vtable_length(int len)          { _vtable_len = len; }
 328 
 329   // Java itable
 330   int  itable_length() const               { return _itable_len; }
 331   void set_itable_length(int len)          { _itable_len = len; }
 332 
 333   // array klasses
 334   klassOop array_klasses() const           { return _array_klasses; }
 335   void set_array_klasses(klassOop k)       { oop_store_without_check((oop*) &_array_klasses, (oop) k); }
 336 
 337   // methods
 338   objArrayOop methods() const              { return _methods; }
 339   void set_methods(objArrayOop a)          { oop_store_without_check((oop*) &_methods, (oop) a); }
 340   methodOop method_with_idnum(int idnum);
 341 
 342   // method ordering
 343   typeArrayOop method_ordering() const     { return _method_ordering; }
 344   void set_method_ordering(typeArrayOop m) { oop_store_without_check((oop*) &_method_ordering, (oop) m); }
 345 
 346   // interfaces
 347   objArrayOop local_interfaces() const          { return _local_interfaces; }
 348   void set_local_interfaces(objArrayOop a)      { oop_store_without_check((oop*) &_local_interfaces, (oop) a); }
 349   objArrayOop transitive_interfaces() const     { return _transitive_interfaces; }
 350   void set_transitive_interfaces(objArrayOop a) { oop_store_without_check((oop*) &_transitive_interfaces, (oop) a); }
 351 
 352  private:
 353   friend class fieldDescriptor;
 354   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
 355 
 356  public:
 357   int     field_offset      (int index) const { return field(index)->offset(); }
 358   int     field_access_flags(int index) const { return field(index)->access_flags(); }
 359   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
 360   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
 361 
 362   // Number of Java declared fields
 363   int java_fields_count() const           { return (int)_java_fields_count; }
 364 
 365   typeArrayOop fields() const              { return _fields; }
 366 
 367   void set_fields(typeArrayOop f, u2 java_fields_count) {
 368     oop_store_without_check((oop*) &_fields, (oop) f);
 369     _java_fields_count = java_fields_count;
 370   }
 371 
 372   // inner classes
 373   typeArrayOop inner_classes() const       { return _inner_classes; }
 374   void set_inner_classes(typeArrayOop f)   { oop_store_without_check((oop*) &_inner_classes, (oop) f); }
 375 
 376   enum InnerClassAttributeOffset {
 377     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 378     inner_class_inner_class_info_offset = 0,
 379     inner_class_outer_class_info_offset = 1,
 380     inner_class_inner_name_offset = 2,
 381     inner_class_access_flags_offset = 3,
 382     inner_class_next_offset = 4
 383   };
 384 
 385   enum EnclosingMethodAttributeOffset {
 386     enclosing_method_class_index_offset = 0,
 387     enclosing_method_method_index_offset = 1,
 388     enclosing_method_attribute_size = 2
 389   };
 390 
 391   // method override check
 392   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
 393 
 394   // package
 395   bool is_same_class_package(klassOop class2);
 396   bool is_same_class_package(oop classloader2, Symbol* classname2);
 397   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
 398 
 399   // find an enclosing class (defined where original code was, in jvm.cpp!)
 400   klassOop compute_enclosing_class(bool* inner_is_member, TRAPS) {
 401     instanceKlassHandle self(THREAD, this->as_klassOop());
 402     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
 403   }
 404   static klassOop compute_enclosing_class_impl(instanceKlassHandle self,
 405                                                bool* inner_is_member, TRAPS);
 406 
 407   // tell if two classes have the same enclosing class (at package level)
 408   bool is_same_package_member(klassOop class2, TRAPS) {
 409     instanceKlassHandle self(THREAD, this->as_klassOop());
 410     return is_same_package_member_impl(self, class2, THREAD);
 411   }
 412   static bool is_same_package_member_impl(instanceKlassHandle self,
 413                                           klassOop class2, TRAPS);
 414 
 415   // initialization state
 416   bool is_loaded() const                   { return _init_state >= loaded; }
 417   bool is_linked() const                   { return _init_state >= linked; }
 418   bool is_initialized() const              { return _init_state == fully_initialized; }
 419   bool is_not_initialized() const          { return _init_state <  being_initialized; }
 420   bool is_being_initialized() const        { return _init_state == being_initialized; }
 421   bool is_in_error_state() const           { return _init_state == initialization_error; }
 422   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 423   ClassState  init_state()                 { return (ClassState)_init_state; }
 424   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
 425 
 426   // defineClass specified verification
 427   bool should_verify_class() const         {
 428     return (_misc_flags & _misc_should_verify_class) != 0;
 429   }
 430   void set_should_verify_class(bool value) {
 431     if (value) {
 432       _misc_flags |= _misc_should_verify_class;
 433     } else {
 434       _misc_flags &= ~_misc_should_verify_class;
 435     }
 436   }
 437 
 438   // marking
 439   bool is_marked_dependent() const         { return _is_marked_dependent; }
 440   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
 441 
 442   // initialization (virtuals from Klass)
 443   bool should_be_initialized() const;  // means that initialize should be called
 444   void initialize(TRAPS);
 445   void link_class(TRAPS);
 446   bool link_class_or_fail(TRAPS); // returns false on failure
 447   void unlink_class();
 448   void rewrite_class(TRAPS);
 449   void relocate_and_link_methods(TRAPS);
 450   methodOop class_initializer();
 451 
 452   // set the class to initialized if no static initializer is present
 453   void eager_initialize(Thread *thread);
 454 
 455   // reference type
 456   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 457   void set_reference_type(ReferenceType t) {
 458     assert(t == (u1)t, "overflow");
 459     _reference_type = (u1)t;
 460   }
 461 
 462   static ByteSize reference_type_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _reference_type)); }
 463 
 464   // find local field, returns true if found
 465   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 466   // find field in direct superinterfaces, returns the interface in which the field is defined
 467   klassOop find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 468   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 469   klassOop find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 470   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 471   klassOop find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 472 
 473   // find a non-static or static field given its offset within the class.
 474   bool contains_field_offset(int offset) {
 475     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
 476   }
 477 
 478   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 479   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 480 
 481   // find a local method (returns NULL if not found)
 482   methodOop find_method(Symbol* name, Symbol* signature) const;
 483   static methodOop find_method(objArrayOop methods, Symbol* name, Symbol* signature);
 484 
 485   // lookup operation (returns NULL if not found)
 486   methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;
 487 
 488   // lookup a method in all the interfaces that this class implements
 489   // (returns NULL if not found)
 490   methodOop lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
 491 
 492   // constant pool
 493   constantPoolOop constants() const        { return _constants; }
 494   void set_constants(constantPoolOop c)    { oop_store_without_check((oop*) &_constants, (oop) c); }
 495 
 496   // class loader
 497   oop class_loader() const                 { return _class_loader; }
 498   void set_class_loader(oop l)             { oop_store((oop*) &_class_loader, l); }
 499 
 500   // protection domain
 501   oop protection_domain()                  { return _protection_domain; }
 502   void set_protection_domain(oop pd)       { oop_store((oop*) &_protection_domain, pd); }
 503 
 504   // host class
 505   oop host_klass() const                   {
 506     oop* hk = adr_host_klass();
 507     if (hk == NULL) {
 508       return NULL;
 509     } else {
 510       return *hk;
 511     }
 512   }
 513   void set_host_klass(oop host)            {
 514     assert(is_anonymous(), "not anonymous");
 515     oop* addr = adr_host_klass();
 516     assert(addr != NULL, "no reversed space");
 517     oop_store(addr, host);
 518   }
 519   bool is_anonymous() const                {
 520     return (_misc_flags & _misc_is_anonymous) != 0;
 521   }
 522   void set_is_anonymous(bool value)        {
 523     if (value) {
 524       _misc_flags |= _misc_is_anonymous;
 525     } else {
 526       _misc_flags &= ~_misc_is_anonymous;
 527     }
 528   }
 529 
 530   // signers
 531   objArrayOop signers() const              { return _signers; }
 532   void set_signers(objArrayOop s)          { oop_store((oop*) &_signers, oop(s)); }
 533 
 534   // source file name
 535   Symbol* source_file_name() const         { return _source_file_name; }
 536   void set_source_file_name(Symbol* n);
 537 
 538   // minor and major version numbers of class file
 539   u2 minor_version() const                 { return _minor_version; }
 540   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
 541   u2 major_version() const                 { return _major_version; }
 542   void set_major_version(u2 major_version) { _major_version = major_version; }
 543 
 544   // source debug extension
 545   Symbol* source_debug_extension() const   { return _source_debug_extension; }
 546   void set_source_debug_extension(Symbol* n);
 547 
 548   // symbol unloading support (refcount already added)
 549   Symbol* array_name()                     { return _array_name; }
 550   void set_array_name(Symbol* name)        { assert(_array_name == NULL, "name already created"); _array_name = name; }
 551 
 552   // nonstatic oop-map blocks
 553   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 554     return oop_map_count * OopMapBlock::size_in_words();
 555   }
 556   unsigned int nonstatic_oop_map_count() const {
 557     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 558   }
 559   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 560   void set_nonstatic_oop_map_size(int words) {
 561     _nonstatic_oop_map_size = words;
 562   }
 563 
 564   // RedefineClasses() support for previous versions:
 565   void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
 566          int emcp_method_count);
 567   // If the _previous_versions array is non-NULL, then this klass
 568   // has been redefined at least once even if we aren't currently
 569   // tracking a previous version.
 570   bool has_been_redefined() const { return _previous_versions != NULL; }
 571   bool has_previous_version() const;
 572   void init_previous_versions() {
 573     _previous_versions = NULL;
 574   }
 575   GrowableArray<PreviousVersionNode *>* previous_versions() const {
 576     return _previous_versions;
 577   }
 578 
 579   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 580   void set_cached_class_file(unsigned char *class_file_bytes,
 581                              jint class_file_len)     { _cached_class_file_len = class_file_len;
 582                                                         _cached_class_file_bytes = class_file_bytes; }
 583   jint get_cached_class_file_len()                    { return _cached_class_file_len; }
 584   unsigned char * get_cached_class_file_bytes()       { return _cached_class_file_bytes; }
 585 
 586   // JVMTI: Support for caching of field indices, types, and offsets
 587   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 588     _jvmti_cached_class_field_map = descriptor;
 589   }
 590   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 591     return _jvmti_cached_class_field_map;
 592   }
 593 
 594   // for adding methods, constMethodOopDesc::UNSET_IDNUM means no more ids available
 595   inline u2 next_method_idnum();
 596   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 597 
 598   // generics support
 599   Symbol* generic_signature() const                   { return _generic_signature; }
 600   void set_generic_signature(Symbol* sig)             { _generic_signature = sig; }
 601 
 602   u2 enclosing_method_data(int offset);
 603   u2 enclosing_method_class_index() {
 604     return enclosing_method_data(enclosing_method_class_index_offset);
 605   }
 606   u2 enclosing_method_method_index() {
 607     return enclosing_method_data(enclosing_method_method_index_offset);
 608   }
 609   void set_enclosing_method_indices(u2 class_index,
 610                                     u2 method_index);
 611 
 612   // jmethodID support
 613   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
 614                      methodHandle method_h);
 615   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
 616                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
 617                      jmethodID* to_dealloc_id_p,
 618                      jmethodID** to_dealloc_jmeths_p);
 619   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
 620                 size_t *length_p, jmethodID* id_p);
 621   jmethodID jmethod_id_or_null(methodOop method);
 622 
 623   // cached itable index support
 624   void set_cached_itable_index(size_t idnum, int index);
 625   int cached_itable_index(size_t idnum);
 626 
 627   // annotations support
 628   typeArrayOop class_annotations() const              { return _class_annotations; }
 629   objArrayOop fields_annotations() const              { return _fields_annotations; }
 630   objArrayOop methods_annotations() const             { return _methods_annotations; }
 631   objArrayOop methods_parameter_annotations() const   { return _methods_parameter_annotations; }
 632   objArrayOop methods_default_annotations() const     { return _methods_default_annotations; }
 633   void set_class_annotations(typeArrayOop md)            { oop_store_without_check((oop*)&_class_annotations, (oop)md); }
 634   void set_fields_annotations(objArrayOop md)            { set_annotations(md, &_fields_annotations); }
 635   void set_methods_annotations(objArrayOop md)           { set_annotations(md, &_methods_annotations); }
 636   void set_methods_parameter_annotations(objArrayOop md) { set_annotations(md, &_methods_parameter_annotations); }
 637   void set_methods_default_annotations(objArrayOop md)   { set_annotations(md, &_methods_default_annotations); }
 638   typeArrayOop get_method_annotations_of(int idnum)
 639                                                 { return get_method_annotations_from(idnum, _methods_annotations); }
 640   typeArrayOop get_method_parameter_annotations_of(int idnum)
 641                                                 { return get_method_annotations_from(idnum, _methods_parameter_annotations); }
 642   typeArrayOop get_method_default_annotations_of(int idnum)
 643                                                 { return get_method_annotations_from(idnum, _methods_default_annotations); }
 644   void set_method_annotations_of(int idnum, typeArrayOop anno)
 645                                                 { set_methods_annotations_of(idnum, anno, &_methods_annotations); }
 646   void set_method_parameter_annotations_of(int idnum, typeArrayOop anno)
 647                                                 { set_methods_annotations_of(idnum, anno, &_methods_parameter_annotations); }
 648   void set_method_default_annotations_of(int idnum, typeArrayOop anno)
 649                                                 { set_methods_annotations_of(idnum, anno, &_methods_default_annotations); }
 650 
 651   // allocation
 652   DEFINE_ALLOCATE_PERMANENT(instanceKlass);
 653   instanceOop allocate_instance(TRAPS);
 654   instanceOop allocate_permanent_instance(TRAPS);
 655 
 656   // additional member function to return a handle
 657   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
 658 
 659   objArrayOop allocate_objArray(int n, int length, TRAPS);
 660   // Helper function
 661   static instanceOop register_finalizer(instanceOop i, TRAPS);
 662 
 663   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 664   // if not, throw either an Error or an Exception.
 665   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 666 
 667   // initialization
 668   void call_class_initializer(TRAPS);
 669   void set_initialization_state_and_notify(ClassState state, TRAPS);
 670 
 671   // OopMapCache support
 672   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 673   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 674   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
 675 
 676   // JNI identifier support (for static fields - for jni performance)
 677   JNIid* jni_ids()                               { return _jni_ids; }
 678   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 679   JNIid* jni_id_for(int offset);
 680 
 681   // maintenance of deoptimization dependencies
 682   int mark_dependent_nmethods(DepChange& changes);
 683   void add_dependent_nmethod(nmethod* nm);
 684   void remove_dependent_nmethod(nmethod* nm);
 685 
 686   // On-stack replacement support
 687   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 688   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 689   void add_osr_nmethod(nmethod* n);
 690   void remove_osr_nmethod(nmethod* n);
 691   nmethod* lookup_osr_nmethod(const methodOop m, int bci, int level, bool match_level) const;
 692 
 693   // Breakpoint support (see methods on methodOop for details)
 694   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 695   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 696 
 697   // support for stub routines
 698   static ByteSize init_state_offset()  { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_state)); }
 699   TRACE_DEFINE_OFFSET;
 700   static ByteSize init_thread_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_thread)); }
 701 
 702   // subclass/subinterface checks
 703   bool implements_interface(klassOop k) const;
 704 
 705   // Access to the implementor of an interface.
 706   klassOop implementor() const
 707   {
 708     klassOop* k = (klassOop*)adr_implementor();
 709     if (k == NULL) {
 710       return NULL;
 711     } else {
 712       return *k;
 713     }
 714   }
 715 
 716   void set_implementor(klassOop k) {
 717     assert(is_interface(), "not interface");
 718     oop* addr = adr_implementor();
 719     oop_store_without_check(addr, k);
 720   }
 721 
 722   int  nof_implementors() const       {
 723     klassOop k = implementor();
 724     if (k == NULL) {
 725       return 0;
 726     } else if (k != this->as_klassOop()) {
 727       return 1;
 728     } else {
 729       return 2;
 730     }
 731   }
 732 
 733   void add_implementor(klassOop k);  // k is a new class that implements this interface
 734   void init_implementor();           // initialize
 735 
 736   // link this class into the implementors list of every interface it implements
 737   void process_interfaces(Thread *thread);
 738 
 739   // virtual operations from Klass
 740   bool is_leaf_class() const               { return _subklass == NULL; }
 741   objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
 742   bool compute_is_subtype_of(klassOop k);
 743   bool can_be_primary_super_slow() const;
 744   klassOop java_super() const              { return super(); }
 745   int oop_size(oop obj)  const             { return size_helper(); }
 746   int klass_oop_size() const               { return object_size(); }
 747   bool oop_is_instance_slow() const        { return true; }
 748 
 749   // Iterators
 750   void do_local_static_fields(FieldClosure* cl);
 751   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 752   void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
 753 
 754   void methods_do(void f(methodOop method));
 755   void array_klasses_do(void f(klassOop k));
 756   void with_array_klasses_do(void f(klassOop k));
 757   bool super_types_do(SuperTypeClosure* blk);
 758 
 759   // Casting from klassOop
 760   static instanceKlass* cast(klassOop k) {
 761     assert(k->is_klass(), "must be");
 762     Klass* kp = k->klass_part();
 763     assert(kp->null_vtbl() || kp->oop_is_instance_slow(), "cast to instanceKlass");
 764     return (instanceKlass*) kp;
 765   }
 766 
 767   // Sizing (in words)
 768   static int header_size()            { return align_object_offset(oopDesc::header_size() + sizeof(instanceKlass)/HeapWordSize); }
 769 
 770   int object_size() const
 771   {
 772     return object_size(align_object_offset(vtable_length()) +
 773                        align_object_offset(itable_length()) +
 774                        ((is_interface() || is_anonymous()) ?
 775                          align_object_offset(nonstatic_oop_map_size()) :
 776                          nonstatic_oop_map_size()) +
 777                        (is_interface() ? (int)sizeof(klassOop)/HeapWordSize : 0) +
 778                        (is_anonymous() ? (int)sizeof(klassOop)/HeapWordSize : 0));
 779   }
 780   static int vtable_start_offset()    { return header_size(); }
 781   static int vtable_length_offset()   { return oopDesc::header_size() + offset_of(instanceKlass, _vtable_len) / HeapWordSize; }
 782   static int object_size(int extra)   { return align_object_size(header_size() + extra); }
 783 
 784   intptr_t* start_of_vtable() const        { return ((intptr_t*)as_klassOop()) + vtable_start_offset(); }
 785   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
 786   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)as_klassOop(); }
 787 
 788   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
 789 
 790   address static_field_addr(int offset);
 791 
 792   OopMapBlock* start_of_nonstatic_oop_maps() const {
 793     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
 794   }
 795 
 796   oop* adr_implementor() const {
 797     if (is_interface()) {
 798       return (oop*)(start_of_nonstatic_oop_maps() +
 799                     nonstatic_oop_map_count());
 800     } else {
 801       return NULL;
 802     }
 803   };
 804 
 805   oop* adr_host_klass() const {
 806     if (is_anonymous()) {
 807       oop* adr_impl = adr_implementor();
 808       if (adr_impl != NULL) {
 809         return adr_impl + 1;
 810       } else {
 811         return (oop*)(start_of_nonstatic_oop_maps() +
 812                       nonstatic_oop_map_count());
 813       }
 814     } else {
 815       return NULL;
 816     }
 817   }
 818 
 819   // Allocation profiling support
 820   juint alloc_size() const            { return _alloc_count * size_helper(); }
 821   void set_alloc_size(juint n)        {}
 822 
 823   // Use this to return the size of an instance in heap words:
 824   int size_helper() const {
 825     return layout_helper_to_size_helper(layout_helper());
 826   }
 827 
 828   // This bit is initialized in classFileParser.cpp.
 829   // It is false under any of the following conditions:
 830   //  - the class is abstract (including any interface)
 831   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
 832   //  - the class size is larger than FastAllocateSizeLimit
 833   //  - the class is java/lang/Class, which cannot be allocated directly
 834   bool can_be_fastpath_allocated() const {
 835     return !layout_helper_needs_slow_path(layout_helper());
 836   }
 837 
 838   // Java vtable/itable
 839   klassVtable* vtable() const;        // return new klassVtable wrapper
 840   inline methodOop method_at_vtable(int index);
 841   klassItable* itable() const;        // return new klassItable wrapper
 842   methodOop method_at_itable(klassOop holder, int index, TRAPS);
 843 
 844   // Garbage collection
 845   void oop_follow_contents(oop obj);
 846   int  oop_adjust_pointers(oop obj);
 847   bool object_is_parsable() const { return _init_state != unparsable_by_gc; }
 848        // Value of _init_state must be zero (unparsable_by_gc) when klass field is set.
 849 
 850   void follow_weak_klass_links(
 851     BoolObjectClosure* is_alive, OopClosure* keep_alive);
 852   void release_C_heap_structures();
 853 
 854   // Parallel Scavenge and Parallel Old
 855   PARALLEL_GC_DECLS
 856 
 857   // Naming
 858   const char* signature_name() const;
 859 
 860   // Iterators
 861   int oop_oop_iterate(oop obj, OopClosure* blk) {
 862     return oop_oop_iterate_v(obj, blk);
 863   }
 864 
 865   int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
 866     return oop_oop_iterate_v_m(obj, blk, mr);
 867   }
 868 
 869 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
 870   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
 871   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
 872                                       MemRegion mr);
 873 
 874   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
 875   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
 876 
 877 #ifndef SERIALGC
 878 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
 879   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
 880 
 881   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 882   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
 883 #endif // !SERIALGC
 884 
 885 private:
 886   // initialization state
 887 #ifdef ASSERT
 888   void set_init_state(ClassState state);
 889 #else
 890   void set_init_state(ClassState state) { _init_state = (u1)state; }
 891 #endif
 892   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
 893   void set_init_thread(Thread *thread)  { _init_thread = thread; }
 894 
 895   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
 896   // The RedefineClasses() API can cause new method idnums to be needed
 897   // which will cause the caches to grow. Safety requires different
 898   // cache management logic if the caches can grow instead of just
 899   // going from NULL to non-NULL.
 900   bool idnum_can_increment() const      { return has_been_redefined(); }
 901   jmethodID* methods_jmethod_ids_acquire() const
 902          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
 903   void release_set_methods_jmethod_ids(jmethodID* jmeths)
 904          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
 905 
 906   int* methods_cached_itable_indices_acquire() const
 907          { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
 908   void release_set_methods_cached_itable_indices(int* indices)
 909          { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
 910 
 911   inline typeArrayOop get_method_annotations_from(int idnum, objArrayOop annos);
 912   void set_annotations(objArrayOop md, objArrayOop* md_p)  { oop_store_without_check((oop*)md_p, (oop)md); }
 913   void set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p);
 914 
 915   // Offsets for memory management
 916   oop* adr_array_klasses() const     { return (oop*)&this->_array_klasses;}
 917   oop* adr_methods() const           { return (oop*)&this->_methods;}
 918   oop* adr_method_ordering() const   { return (oop*)&this->_method_ordering;}
 919   oop* adr_local_interfaces() const  { return (oop*)&this->_local_interfaces;}
 920   oop* adr_transitive_interfaces() const  { return (oop*)&this->_transitive_interfaces;}
 921   oop* adr_fields() const            { return (oop*)&this->_fields;}
 922   oop* adr_constants() const         { return (oop*)&this->_constants;}
 923   oop* adr_class_loader() const      { return (oop*)&this->_class_loader;}
 924   oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
 925   oop* adr_signers() const           { return (oop*)&this->_signers;}
 926   oop* adr_inner_classes() const     { return (oop*)&this->_inner_classes;}
 927   oop* adr_methods_jmethod_ids() const             { return (oop*)&this->_methods_jmethod_ids;}
 928   oop* adr_methods_cached_itable_indices() const   { return (oop*)&this->_methods_cached_itable_indices;}
 929   oop* adr_class_annotations() const   { return (oop*)&this->_class_annotations;}
 930   oop* adr_fields_annotations() const  { return (oop*)&this->_fields_annotations;}
 931   oop* adr_methods_annotations() const { return (oop*)&this->_methods_annotations;}
 932   oop* adr_methods_parameter_annotations() const { return (oop*)&this->_methods_parameter_annotations;}
 933   oop* adr_methods_default_annotations() const { return (oop*)&this->_methods_default_annotations;}
 934 
 935   // Static methods that are used to implement member methods where an exposed this pointer
 936   // is needed due to possible GCs
 937   static bool link_class_impl                           (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
 938   static bool verify_code                               (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
 939   static void initialize_impl                           (instanceKlassHandle this_oop, TRAPS);
 940   static void eager_initialize_impl                     (instanceKlassHandle this_oop);
 941   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_oop, ClassState state, TRAPS);
 942   static void call_class_initializer_impl               (instanceKlassHandle this_oop, TRAPS);
 943   static klassOop array_klass_impl                      (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
 944   static void do_local_static_fields_impl               (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
 945   /* jni_id_for_impl for jfieldID only */
 946   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_oop, int offset);
 947 
 948   // Returns the array class for the n'th dimension
 949   klassOop array_klass_impl(bool or_null, int n, TRAPS);
 950 
 951   // Returns the array class with this class as element type
 952   klassOop array_klass_impl(bool or_null, TRAPS);
 953 
 954 public:
 955   // sharing support
 956   virtual void remove_unshareable_info();
 957   virtual void shared_symbols_iterate(SymbolClosure* closure);
 958 
 959   // jvm support
 960   jint compute_modifier_flags(TRAPS) const;
 961 
 962 public:
 963   // JVMTI support
 964   jint jvmti_class_status() const;
 965 
 966  public:
 967   // Printing
 968   void oop_print_value_on(oop obj, outputStream* st);
 969 #ifndef PRODUCT
 970   void oop_print_on      (oop obj, outputStream* st);
 971 
 972   void print_dependent_nmethods(bool verbose = false);
 973   bool is_dependent_nmethod(nmethod* nm);
 974 #endif
 975 
 976   // Verification
 977   const char* internal_name() const;
 978   void oop_verify_on(oop obj, outputStream* st);
 979 };
 980 
 981 inline methodOop instanceKlass::method_at_vtable(int index)  {
 982 #ifndef PRODUCT
 983   assert(index >= 0, "valid vtable index");
 984   if (DebugVtables) {
 985     verify_vtable_index(index);
 986   }
 987 #endif
 988   vtableEntry* ve = (vtableEntry*)start_of_vtable();
 989   return ve[index].method();
 990 }
 991 
 992 inline typeArrayOop instanceKlass::get_method_annotations_from(int idnum, objArrayOop annos) {
 993   if (annos == NULL || annos->length() <= idnum) {
 994     return NULL;
 995   }
 996   return typeArrayOop(annos->obj_at(idnum));
 997 }
 998 
 999 // for adding methods
1000 // UNSET_IDNUM return means no more ids available
1001 inline u2 instanceKlass::next_method_idnum() {
1002   if (_idnum_allocated_count == constMethodOopDesc::MAX_IDNUM) {
1003     return constMethodOopDesc::UNSET_IDNUM; // no more ids available
1004   } else {
1005     return _idnum_allocated_count++;
1006   }
1007 }
1008 
1009 
1010 /* JNIid class for jfieldIDs only */
1011 class JNIid: public CHeapObj<mtClass> {
1012   friend class VMStructs;
1013  private:
1014   klassOop           _holder;
1015   JNIid*             _next;
1016   int                _offset;
1017 #ifdef ASSERT
1018   bool               _is_static_field_id;
1019 #endif
1020 
1021  public:
1022   // Accessors
1023   klassOop holder() const         { return _holder; }
1024   int offset() const              { return _offset; }
1025   JNIid* next()                   { return _next; }
1026   // Constructor
1027   JNIid(klassOop holder, int offset, JNIid* next);
1028   // Identifier lookup
1029   JNIid* find(int offset);
1030 
1031   bool find_local_field(fieldDescriptor* fd) {
1032     return instanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1033   }
1034 
1035   // Garbage collection support
1036   oop* holder_addr() { return (oop*)&_holder; }
1037   void oops_do(OopClosure* f);
1038   static void deallocate(JNIid* id);
1039   // Debugging
1040 #ifdef ASSERT
1041   bool is_static_field_id() const { return _is_static_field_id; }
1042   void set_is_static_field_id()   { _is_static_field_id = true; }
1043 #endif
1044   void verify(klassOop holder);
1045 };
1046 
1047 
1048 // If breakpoints are more numerous than just JVMTI breakpoints,
1049 // consider compressing this data structure.
1050 // It is currently a simple linked list defined in methodOop.hpp.
1051 
1052 class BreakpointInfo;
1053 
1054 
1055 // A collection point for interesting information about the previous
1056 // version(s) of an instanceKlass. This class uses weak references to
1057 // the information so that the information may be collected as needed
1058 // by the system. If the information is shared, then a regular
1059 // reference must be used because a weak reference would be seen as
1060 // collectible. A GrowableArray of PreviousVersionNodes is attached
1061 // to the instanceKlass as needed. See PreviousVersionWalker below.
1062 class PreviousVersionNode : public CHeapObj<mtClass> {
1063  private:
1064   // A shared ConstantPool is never collected so we'll always have
1065   // a reference to it so we can update items in the cache. We'll
1066   // have a weak reference to a non-shared ConstantPool until all
1067   // of the methods (EMCP or obsolete) have been collected; the
1068   // non-shared ConstantPool becomes collectible at that point.
1069   jobject _prev_constant_pool;  // regular or weak reference
1070   bool    _prev_cp_is_weak;     // true if not a shared ConstantPool
1071 
1072   // If the previous version of the instanceKlass doesn't have any
1073   // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
1074   // EMCP methods have been collected, then _prev_EMCP_methods can
1075   // have a length of zero.
1076   GrowableArray<jweak>* _prev_EMCP_methods;
1077 
1078 public:
1079   PreviousVersionNode(jobject prev_constant_pool, bool prev_cp_is_weak,
1080     GrowableArray<jweak>* prev_EMCP_methods);
1081   ~PreviousVersionNode();
1082   jobject prev_constant_pool() const {
1083     return _prev_constant_pool;
1084   }
1085   GrowableArray<jweak>* prev_EMCP_methods() const {
1086     return _prev_EMCP_methods;
1087   }
1088 };
1089 
1090 
1091 // A Handle-ized version of PreviousVersionNode.
1092 class PreviousVersionInfo : public ResourceObj {
1093  private:
1094   constantPoolHandle   _prev_constant_pool_handle;
1095   // If the previous version of the instanceKlass doesn't have any
1096   // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
1097   // methods cannot be collected while we hold a handle,
1098   // _prev_EMCP_methods should never have a length of zero.
1099   GrowableArray<methodHandle>* _prev_EMCP_method_handles;
1100 
1101 public:
1102   PreviousVersionInfo(PreviousVersionNode *pv_node);
1103   ~PreviousVersionInfo();
1104   constantPoolHandle prev_constant_pool_handle() const {
1105     return _prev_constant_pool_handle;
1106   }
1107   GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
1108     return _prev_EMCP_method_handles;
1109   }
1110 };
1111 
1112 
1113 // Helper object for walking previous versions. This helper cleans up
1114 // the Handles that it allocates when the helper object is destroyed.
1115 // The PreviousVersionInfo object returned by next_previous_version()
1116 // is only valid until a subsequent call to next_previous_version() or
1117 // the helper object is destroyed.
1118 class PreviousVersionWalker : public StackObj {
1119  private:
1120   GrowableArray<PreviousVersionNode *>* _previous_versions;
1121   int                                   _current_index;
1122   // Fields for cleaning up when we are done walking the previous versions:
1123   // A HandleMark for the PreviousVersionInfo handles:
1124   HandleMark                            _hm;
1125 
1126   // It would be nice to have a ResourceMark field in this helper also,
1127   // but the ResourceMark code says to be careful to delete handles held
1128   // in GrowableArrays _before_ deleting the GrowableArray. Since we
1129   // can't guarantee the order in which the fields are destroyed, we
1130   // have to let the creator of the PreviousVersionWalker object do
1131   // the right thing. Also, adding a ResourceMark here causes an
1132   // include loop.
1133 
1134   // A pointer to the current info object so we can handle the deletes.
1135   PreviousVersionInfo *                 _current_p;
1136 
1137  public:
1138   PreviousVersionWalker(instanceKlass *ik);
1139   ~PreviousVersionWalker();
1140 
1141   // Return the interesting information for the next previous version
1142   // of the klass. Returns NULL if there are no more previous versions.
1143   PreviousVersionInfo* next_previous_version();
1144 };
1145 
1146 
1147 //
1148 // nmethodBucket is used to record dependent nmethods for
1149 // deoptimization.  nmethod dependencies are actually <klass, method>
1150 // pairs but we really only care about the klass part for purposes of
1151 // finding nmethods which might need to be deoptimized.  Instead of
1152 // recording the method, a count of how many times a particular nmethod
1153 // was recorded is kept.  This ensures that any recording errors are
1154 // noticed since an nmethod should be removed as many times are it's
1155 // added.
1156 //
1157 class nmethodBucket: public CHeapObj<mtClass> {
1158   friend class VMStructs;
1159  private:
1160   nmethod*       _nmethod;
1161   int            _count;
1162   nmethodBucket* _next;
1163 
1164  public:
1165   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1166     _nmethod = nmethod;
1167     _next = next;
1168     _count = 1;
1169   }
1170   int count()                             { return _count; }
1171   int increment()                         { _count += 1; return _count; }
1172   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1173   nmethodBucket* next()                   { return _next; }
1174   void set_next(nmethodBucket* b)         { _next = b; }
1175   nmethod* get_nmethod()                  { return _nmethod; }
1176 };
1177 
1178 // An iterator that's used to access the inner classes indices in the
1179 // instanceKlass::_inner_classes array.
1180 class InnerClassesIterator : public StackObj {
1181  private:
1182   typeArrayHandle _inner_classes;
1183   int _length;
1184   int _idx;
1185  public:
1186 
1187   InnerClassesIterator(instanceKlassHandle k) {
1188     _inner_classes = k->inner_classes();
1189     if (k->inner_classes() != NULL) {
1190       _length = _inner_classes->length();
1191       // The inner class array's length should be the multiple of
1192       // inner_class_next_offset if it only contains the InnerClasses
1193       // attribute data, or it should be
1194       // n*inner_class_next_offset+enclosing_method_attribute_size
1195       // if it also contains the EnclosingMethod data.
1196       assert((_length % instanceKlass::inner_class_next_offset == 0 ||
1197               _length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size),
1198              "just checking");
1199       // Remove the enclosing_method portion if exists.
1200       if (_length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size) {
1201         _length -= instanceKlass::enclosing_method_attribute_size;
1202       }
1203     } else {
1204       _length = 0;
1205     }
1206     _idx = 0;
1207   }
1208 
1209   int length() const {
1210     return _length;
1211   }
1212 
1213   void next() {
1214     _idx += instanceKlass::inner_class_next_offset;
1215   }
1216 
1217   bool done() const {
1218     return (_idx >= _length);
1219   }
1220 
1221   u2 inner_class_info_index() const {
1222     return _inner_classes->ushort_at(
1223                _idx + instanceKlass::inner_class_inner_class_info_offset);
1224   }
1225 
1226   void set_inner_class_info_index(u2 index) {
1227     _inner_classes->ushort_at_put(
1228                _idx + instanceKlass::inner_class_inner_class_info_offset, index);
1229   }
1230 
1231   u2 outer_class_info_index() const {
1232     return _inner_classes->ushort_at(
1233                _idx + instanceKlass::inner_class_outer_class_info_offset);
1234   }
1235 
1236   void set_outer_class_info_index(u2 index) {
1237     _inner_classes->ushort_at_put(
1238                _idx + instanceKlass::inner_class_outer_class_info_offset, index);
1239   }
1240 
1241   u2 inner_name_index() const {
1242     return _inner_classes->ushort_at(
1243                _idx + instanceKlass::inner_class_inner_name_offset);
1244   }
1245 
1246   void set_inner_name_index(u2 index) {
1247     _inner_classes->ushort_at_put(
1248                _idx + instanceKlass::inner_class_inner_name_offset, index);
1249   }
1250 
1251   u2 inner_access_flags() const {
1252     return _inner_classes->ushort_at(
1253                _idx + instanceKlass::inner_class_access_flags_offset);
1254   }
1255 };
1256 
1257 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP