src/share/vm/oops/instanceKlass.hpp

Mon, 10 Feb 2014 21:29:14 -0800

author
minqi
date
Mon, 10 Feb 2014 21:29:14 -0800
changeset 6351
f9e35a9dc8c7
parent 6316
85318d1fe8fe
child 6377
b8413a9cbb84
permissions
-rw-r--r--

8033792: AltHashing used jint for imprecise bit shifting
Summary: AltHashing used jint the way of juint in bit shifting which could lead loss of precision. Fix by change _seed defined as juint.
Reviewed-by: coleenp, ccheung
Contributed-by: yumin.qi@oracle.com

     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  */
    25 #ifndef SHARE_VM_OOPS_INSTANCEKLASS_HPP
    26 #define SHARE_VM_OOPS_INSTANCEKLASS_HPP
    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/atomic.hpp"
    36 #include "runtime/handles.hpp"
    37 #include "runtime/os.hpp"
    38 #include "utilities/accessFlags.hpp"
    39 #include "utilities/bitMap.inline.hpp"
    40 #include "utilities/macros.hpp"
    41 #include "trace/traceMacros.hpp"
    43 // An InstanceKlass is the VM level representation of a Java class.
    44 // It contains all information needed for at class at execution runtime.
    46 //  InstanceKlass layout:
    47 //    [C++ vtbl pointer           ] Klass
    48 //    [subtype cache              ] Klass
    49 //    [instance size              ] Klass
    50 //    [java mirror                ] Klass
    51 //    [super                      ] Klass
    52 //    [access_flags               ] Klass
    53 //    [name                       ] Klass
    54 //    [first subklass             ] Klass
    55 //    [next sibling               ] Klass
    56 //    [array klasses              ]
    57 //    [methods                    ]
    58 //    [local interfaces           ]
    59 //    [transitive interfaces      ]
    60 //    [fields                     ]
    61 //    [constants                  ]
    62 //    [class loader               ]
    63 //    [source file name           ]
    64 //    [inner classes              ]
    65 //    [static field size          ]
    66 //    [nonstatic field size       ]
    67 //    [static oop fields size     ]
    68 //    [nonstatic oop maps size    ]
    69 //    [has finalize method        ]
    70 //    [deoptimization mark bit    ]
    71 //    [initialization state       ]
    72 //    [initializing thread        ]
    73 //    [Java vtable length         ]
    74 //    [oop map cache (stack maps) ]
    75 //    [EMBEDDED Java vtable             ] size in words = vtable_len
    76 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
    77 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
    78 //      indicating where oops are located in instances of this klass.
    79 //    [EMBEDDED implementor of the interface] only exist for interface
    80 //    [EMBEDDED host klass        ] only exist for an anonymous class (JSR 292 enabled)
    83 // forward declaration for class -- see below for definition
    84 class SuperTypeClosure;
    85 class JNIid;
    86 class jniIdMapBase;
    87 class BreakpointInfo;
    88 class fieldDescriptor;
    89 class DepChange;
    90 class nmethodBucket;
    91 class PreviousVersionNode;
    92 class JvmtiCachedClassFieldMap;
    93 class MemberNameTable;
    95 // This is used in iterators below.
    96 class FieldClosure: public StackObj {
    97 public:
    98   virtual void do_field(fieldDescriptor* fd) = 0;
    99 };
   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
   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; }
   121   // Number of oops in this block.
   122   uint count() const         { return _count; }
   123   void set_count(uint count) { _count = count; }
   125   // sizeof(OopMapBlock) in HeapWords.
   126   static const int size_in_words() {
   127     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
   128       LogHeapWordSize;
   129   }
   131  private:
   132   int  _offset;
   133   uint _count;
   134 };
   136 struct JvmtiCachedClassFileData;
   138 class InstanceKlass: public Klass {
   139   friend class VMStructs;
   140   friend class ClassFileParser;
   141   friend class CompileReplay;
   143  protected:
   144   // Constructor
   145   InstanceKlass(int vtable_len,
   146                 int itable_len,
   147                 int static_field_size,
   148                 int nonstatic_oop_map_size,
   149                 ReferenceType rt,
   150                 AccessFlags access_flags,
   151                 bool is_anonymous);
   152  public:
   153   static InstanceKlass* allocate_instance_klass(
   154                                           ClassLoaderData* loader_data,
   155                                           int vtable_len,
   156                                           int itable_len,
   157                                           int static_field_size,
   158                                           int nonstatic_oop_map_size,
   159                                           ReferenceType rt,
   160                                           AccessFlags access_flags,
   161                                           Symbol* name,
   162                                           Klass* super_klass,
   163                                           bool is_anonymous,
   164                                           TRAPS);
   166   InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
   168   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
   169   // of the class loading & initialization procedure, and the use of the states.
   170   enum ClassState {
   171     allocated,                          // allocated (but not yet linked)
   172     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
   173     linked,                             // successfully linked/verified (but not initialized yet)
   174     being_initialized,                  // currently running class initializer
   175     fully_initialized,                  // initialized (successfull final state)
   176     initialization_error                // error happened during initialization
   177   };
   179   static int number_of_instance_classes() { return _total_instanceKlass_count; }
   181  private:
   182   static volatile int _total_instanceKlass_count;
   184  protected:
   185   // Annotations for this class
   186   Annotations*    _annotations;
   187   // Array classes holding elements of this class.
   188   Klass*          _array_klasses;
   189   // Constant pool for this class.
   190   ConstantPool* _constants;
   191   // The InnerClasses attribute and EnclosingMethod attribute. The
   192   // _inner_classes is an array of shorts. If the class has InnerClasses
   193   // attribute, then the _inner_classes array begins with 4-tuples of shorts
   194   // [inner_class_info_index, outer_class_info_index,
   195   // inner_name_index, inner_class_access_flags] for the InnerClasses
   196   // attribute. If the EnclosingMethod attribute exists, it occupies the
   197   // last two shorts [class_index, method_index] of the array. If only
   198   // the InnerClasses attribute exists, the _inner_classes array length is
   199   // number_of_inner_classes * 4. If the class has both InnerClasses
   200   // and EnclosingMethod attributes the _inner_classes array length is
   201   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
   202   Array<jushort>* _inner_classes;
   204   // the source debug extension for this klass, NULL if not specified.
   205   // Specified as UTF-8 string without terminating zero byte in the classfile,
   206   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
   207   char*           _source_debug_extension;
   208   // Array name derived from this class which needs unreferencing
   209   // if this class is unloaded.
   210   Symbol*         _array_name;
   212   // Number of heapOopSize words used by non-static fields in this klass
   213   // (including inherited fields but after header_size()).
   214   int             _nonstatic_field_size;
   215   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
   216   // Constant pool index to the utf8 entry of the Generic signature,
   217   // or 0 if none.
   218   u2              _generic_signature_index;
   219   // Constant pool index to the utf8 entry for the name of source file
   220   // containing this klass, 0 if not specified.
   221   u2              _source_file_name_index;
   222   u2              _static_oop_field_count;// number of static oop fields in this klass
   223   u2              _java_fields_count;    // The number of declared Java fields
   224   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
   226   // _is_marked_dependent can be set concurrently, thus cannot be part of the
   227   // _misc_flags.
   228   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
   230   enum {
   231     _misc_rewritten            = 1 << 0, // methods rewritten.
   232     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
   233     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
   234     _misc_is_anonymous         = 1 << 3, // has embedded _host_klass field
   235     _misc_is_contended         = 1 << 4, // marked with contended annotation
   236     _misc_has_default_methods  = 1 << 5  // class/superclass/implemented interfaces has default methods
   237   };
   238   u2              _misc_flags;
   239   u2              _minor_version;        // minor version number of class file
   240   u2              _major_version;        // major version number of class file
   241   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
   242   int             _vtable_len;           // length of Java vtable (in words)
   243   int             _itable_len;           // length of Java itable (in words)
   244   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
   245   MemberNameTable* _member_names;        // Member names
   246   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
   247   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
   248   nmethodBucket*  _dependencies;         // list of dependent nmethods
   249   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
   250   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
   251   // Array of interesting part(s) of the previous version(s) of this
   252   // InstanceKlass. See PreviousVersionWalker below.
   253   GrowableArray<PreviousVersionNode *>* _previous_versions;
   254   // JVMTI fields can be moved to their own structure - see 6315920
   255   // JVMTI: cached class file, before retransformable agent modified it in CFLH
   256   JvmtiCachedClassFileData* _cached_class_file;
   258   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
   260   // Class states are defined as ClassState (see above).
   261   // Place the _init_state here to utilize the unused 2-byte after
   262   // _idnum_allocated_count.
   263   u1              _init_state;                    // state of class
   264   u1              _reference_type;                // reference type
   266   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
   268   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
   270   // Method array.
   271   Array<Method*>* _methods;
   272   // Default Method Array, concrete methods inherited from interfaces
   273   Array<Method*>* _default_methods;
   274   // Interface (Klass*s) this class declares locally to implement.
   275   Array<Klass*>* _local_interfaces;
   276   // Interface (Klass*s) this class implements transitively.
   277   Array<Klass*>* _transitive_interfaces;
   278   // Int array containing the original order of method in the class file (for JVMTI).
   279   Array<int>*     _method_ordering;
   280   // Int array containing the vtable_indices for default_methods
   281   // offset matches _default_methods offset
   282   Array<int>*     _default_vtable_indices;
   284   // Instance and static variable information, starts with 6-tuples of shorts
   285   // [access, name index, sig index, initval index, low_offset, high_offset]
   286   // for all fields, followed by the generic signature data at the end of
   287   // the array. Only fields with generic signature attributes have the generic
   288   // signature data set in the array. The fields array looks like following:
   289   //
   290   // f1: [access, name index, sig index, initial value index, low_offset, high_offset]
   291   // f2: [access, name index, sig index, initial value index, low_offset, high_offset]
   292   //      ...
   293   // fn: [access, name index, sig index, initial value index, low_offset, high_offset]
   294   //     [generic signature index]
   295   //     [generic signature index]
   296   //     ...
   297   Array<u2>*      _fields;
   299   // embedded Java vtable follows here
   300   // embedded Java itables follows here
   301   // embedded static fields follows here
   302   // embedded nonstatic oop-map blocks follows here
   303   // embedded implementor of this interface follows here
   304   //   The embedded implementor only exists if the current klass is an
   305   //   iterface. The possible values of the implementor fall into following
   306   //   three cases:
   307   //     NULL: no implementor.
   308   //     A Klass* that's not itself: one implementor.
   309   //     Itsef: more than one implementors.
   310   // embedded host klass follows here
   311   //   The embedded host klass only exists in an anonymous class for
   312   //   dynamic language support (JSR 292 enabled). The host class grants
   313   //   its access privileges to this class also. The host class is either
   314   //   named, or a previously loaded anonymous class. A non-anonymous class
   315   //   or an anonymous class loaded through normal classloading does not
   316   //   have this embedded field.
   317   //
   319   friend class SystemDictionary;
   321  public:
   322   bool has_nonstatic_fields() const        {
   323     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
   324   }
   325   void set_has_nonstatic_fields(bool b)    {
   326     if (b) {
   327       _misc_flags |= _misc_has_nonstatic_fields;
   328     } else {
   329       _misc_flags &= ~_misc_has_nonstatic_fields;
   330     }
   331   }
   333   // field sizes
   334   int nonstatic_field_size() const         { return _nonstatic_field_size; }
   335   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
   337   int static_field_size() const            { return _static_field_size; }
   338   void set_static_field_size(int size)     { _static_field_size = size; }
   340   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
   341   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
   343   // Java vtable
   344   int  vtable_length() const               { return _vtable_len; }
   345   void set_vtable_length(int len)          { _vtable_len = len; }
   347   // Java itable
   348   int  itable_length() const               { return _itable_len; }
   349   void set_itable_length(int len)          { _itable_len = len; }
   351   // array klasses
   352   Klass* array_klasses() const             { return _array_klasses; }
   353   void set_array_klasses(Klass* k)         { _array_klasses = k; }
   355   // methods
   356   Array<Method*>* methods() const          { return _methods; }
   357   void set_methods(Array<Method*>* a)      { _methods = a; }
   358   Method* method_with_idnum(int idnum);
   360   // method ordering
   361   Array<int>* method_ordering() const     { return _method_ordering; }
   362   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
   363   void copy_method_ordering(intArray* m, TRAPS);
   365   // default_methods
   366   Array<Method*>* default_methods() const  { return _default_methods; }
   367   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
   369   // default method vtable_indices
   370   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
   371   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
   372   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
   374   // interfaces
   375   Array<Klass*>* local_interfaces() const          { return _local_interfaces; }
   376   void set_local_interfaces(Array<Klass*>* a)      {
   377     guarantee(_local_interfaces == NULL || a == NULL, "Just checking");
   378     _local_interfaces = a; }
   380   Array<Klass*>* transitive_interfaces() const     { return _transitive_interfaces; }
   381   void set_transitive_interfaces(Array<Klass*>* a) {
   382     guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");
   383     _transitive_interfaces = a;
   384   }
   386  private:
   387   friend class fieldDescriptor;
   388   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
   390  public:
   391   int     field_offset      (int index) const { return field(index)->offset(); }
   392   int     field_access_flags(int index) const { return field(index)->access_flags(); }
   393   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
   394   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
   396   // Number of Java declared fields
   397   int java_fields_count() const           { return (int)_java_fields_count; }
   399   Array<u2>* fields() const            { return _fields; }
   400   void set_fields(Array<u2>* f, u2 java_fields_count) {
   401     guarantee(_fields == NULL || f == NULL, "Just checking");
   402     _fields = f;
   403     _java_fields_count = java_fields_count;
   404   }
   406   // inner classes
   407   Array<u2>* inner_classes() const       { return _inner_classes; }
   408   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
   410   enum InnerClassAttributeOffset {
   411     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
   412     inner_class_inner_class_info_offset = 0,
   413     inner_class_outer_class_info_offset = 1,
   414     inner_class_inner_name_offset = 2,
   415     inner_class_access_flags_offset = 3,
   416     inner_class_next_offset = 4
   417   };
   419   enum EnclosingMethodAttributeOffset {
   420     enclosing_method_class_index_offset = 0,
   421     enclosing_method_method_index_offset = 1,
   422     enclosing_method_attribute_size = 2
   423   };
   425   // method override check
   426   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
   428   // package
   429   bool is_same_class_package(Klass* class2);
   430   bool is_same_class_package(oop classloader2, Symbol* classname2);
   431   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
   433   // find an enclosing class (defined where original code was, in jvm.cpp!)
   434   Klass* compute_enclosing_class(bool* inner_is_member, TRAPS) {
   435     instanceKlassHandle self(THREAD, this);
   436     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
   437   }
   438   static Klass* compute_enclosing_class_impl(instanceKlassHandle self,
   439                                                bool* inner_is_member, TRAPS);
   441   // tell if two classes have the same enclosing class (at package level)
   442   bool is_same_package_member(Klass* class2, TRAPS) {
   443     instanceKlassHandle self(THREAD, this);
   444     return is_same_package_member_impl(self, class2, THREAD);
   445   }
   446   static bool is_same_package_member_impl(instanceKlassHandle self,
   447                                           Klass* class2, TRAPS);
   449   // initialization state
   450   bool is_loaded() const                   { return _init_state >= loaded; }
   451   bool is_linked() const                   { return _init_state >= linked; }
   452   bool is_initialized() const              { return _init_state == fully_initialized; }
   453   bool is_not_initialized() const          { return _init_state <  being_initialized; }
   454   bool is_being_initialized() const        { return _init_state == being_initialized; }
   455   bool is_in_error_state() const           { return _init_state == initialization_error; }
   456   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
   457   ClassState  init_state()                 { return (ClassState)_init_state; }
   458   bool is_rewritten() const                { return (_misc_flags & _misc_rewritten) != 0; }
   460   // defineClass specified verification
   461   bool should_verify_class() const         {
   462     return (_misc_flags & _misc_should_verify_class) != 0;
   463   }
   464   void set_should_verify_class(bool value) {
   465     if (value) {
   466       _misc_flags |= _misc_should_verify_class;
   467     } else {
   468       _misc_flags &= ~_misc_should_verify_class;
   469     }
   470   }
   472   // marking
   473   bool is_marked_dependent() const         { return _is_marked_dependent; }
   474   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
   476   // initialization (virtuals from Klass)
   477   bool should_be_initialized() const;  // means that initialize should be called
   478   void initialize(TRAPS);
   479   void link_class(TRAPS);
   480   bool link_class_or_fail(TRAPS); // returns false on failure
   481   void unlink_class();
   482   void rewrite_class(TRAPS);
   483   void link_methods(TRAPS);
   484   Method* class_initializer();
   486   // set the class to initialized if no static initializer is present
   487   void eager_initialize(Thread *thread);
   489   // reference type
   490   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
   491   void set_reference_type(ReferenceType t) {
   492     assert(t == (u1)t, "overflow");
   493     _reference_type = (u1)t;
   494   }
   496   static ByteSize reference_type_offset() { return in_ByteSize(offset_of(InstanceKlass, _reference_type)); }
   498   // find local field, returns true if found
   499   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   500   // find field in direct superinterfaces, returns the interface in which the field is defined
   501   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   502   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
   503   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   504   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
   505   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
   507   // find a non-static or static field given its offset within the class.
   508   bool contains_field_offset(int offset) {
   509     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
   510   }
   512   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
   513   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
   515   // find a local method (returns NULL if not found)
   516   Method* find_method(Symbol* name, Symbol* signature) const;
   517   static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
   518   static Method* find_instance_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
   520   // find a local method index in default_methods (returns -1 if not found)
   521   static int find_method_index(Array<Method*>* methods, Symbol* name, Symbol* signature);
   523   // lookup operation (returns NULL if not found)
   524   Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
   526   // lookup a method in all the interfaces that this class implements
   527   // (returns NULL if not found)
   528   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, bool skip_default_methods) const;
   530   // lookup a method in local defaults then in all interfaces
   531   // (returns NULL if not found)
   532   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
   534   // Find method indices by name.  If a method with the specified name is
   535   // found the index to the first method is returned, and 'end' is filled in
   536   // with the index of first non-name-matching method.  If no method is found
   537   // -1 is returned.
   538   int find_method_by_name(Symbol* name, int* end);
   539   static int find_method_by_name(Array<Method*>* methods, Symbol* name, int* end);
   541   // constant pool
   542   ConstantPool* constants() const        { return _constants; }
   543   void set_constants(ConstantPool* c)    { _constants = c; }
   545   // protection domain
   546   oop protection_domain() const;
   548   // signers
   549   objArrayOop signers() const;
   551   // host class
   552   Klass* host_klass() const              {
   553     Klass** hk = (Klass**)adr_host_klass();
   554     if (hk == NULL) {
   555       return NULL;
   556     } else {
   557       assert(*hk != NULL, "host klass should always be set if the address is not null");
   558       return *hk;
   559     }
   560   }
   561   void set_host_klass(Klass* host)            {
   562     assert(is_anonymous(), "not anonymous");
   563     Klass** addr = (Klass**)adr_host_klass();
   564     assert(addr != NULL, "no reversed space");
   565     if (addr != NULL) {
   566       *addr = host;
   567     }
   568   }
   569   bool is_anonymous() const                {
   570     return (_misc_flags & _misc_is_anonymous) != 0;
   571   }
   572   void set_is_anonymous(bool value)        {
   573     if (value) {
   574       _misc_flags |= _misc_is_anonymous;
   575     } else {
   576       _misc_flags &= ~_misc_is_anonymous;
   577     }
   578   }
   580   // Oop that keeps the metadata for this class from being unloaded
   581   // in places where the metadata is stored in other places, like nmethods
   582   oop klass_holder() const {
   583     return is_anonymous() ? java_mirror() : class_loader();
   584   }
   586   bool is_contended() const                {
   587     return (_misc_flags & _misc_is_contended) != 0;
   588   }
   589   void set_is_contended(bool value)        {
   590     if (value) {
   591       _misc_flags |= _misc_is_contended;
   592     } else {
   593       _misc_flags &= ~_misc_is_contended;
   594     }
   595   }
   597   // source file name
   598   Symbol* source_file_name() const               {
   599     return (_source_file_name_index == 0) ?
   600       (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
   601   }
   602   u2 source_file_name_index() const              {
   603     return _source_file_name_index;
   604   }
   605   void set_source_file_name_index(u2 sourcefile_index) {
   606     _source_file_name_index = sourcefile_index;
   607   }
   609   // minor and major version numbers of class file
   610   u2 minor_version() const                 { return _minor_version; }
   611   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
   612   u2 major_version() const                 { return _major_version; }
   613   void set_major_version(u2 major_version) { _major_version = major_version; }
   615   // source debug extension
   616   char* source_debug_extension() const     { return _source_debug_extension; }
   617   void set_source_debug_extension(char* array, int length);
   619   // symbol unloading support (refcount already added)
   620   Symbol* array_name()                     { return _array_name; }
   621   void set_array_name(Symbol* name)        { assert(_array_name == NULL  || name == NULL, "name already created"); _array_name = name; }
   623   // nonstatic oop-map blocks
   624   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
   625     return oop_map_count * OopMapBlock::size_in_words();
   626   }
   627   unsigned int nonstatic_oop_map_count() const {
   628     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
   629   }
   630   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
   631   void set_nonstatic_oop_map_size(int words) {
   632     _nonstatic_oop_map_size = words;
   633   }
   635   // RedefineClasses() support for previous versions:
   636   void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
   637          int emcp_method_count);
   638   // If the _previous_versions array is non-NULL, then this klass
   639   // has been redefined at least once even if we aren't currently
   640   // tracking a previous version.
   641   bool has_been_redefined() const { return _previous_versions != NULL; }
   642   bool has_previous_version() const;
   643   void init_previous_versions() {
   644     _previous_versions = NULL;
   645   }
   646   GrowableArray<PreviousVersionNode *>* previous_versions() const {
   647     return _previous_versions;
   648   }
   650   static void purge_previous_versions(InstanceKlass* ik);
   652   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
   653   void set_cached_class_file(JvmtiCachedClassFileData *data) {
   654     _cached_class_file = data;
   655   }
   656   JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
   657   jint get_cached_class_file_len();
   658   unsigned char * get_cached_class_file_bytes();
   660   // JVMTI: Support for caching of field indices, types, and offsets
   661   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
   662     _jvmti_cached_class_field_map = descriptor;
   663   }
   664   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
   665     return _jvmti_cached_class_field_map;
   666   }
   668   bool has_default_methods() const {
   669     return (_misc_flags & _misc_has_default_methods) != 0;
   670   }
   671   void set_has_default_methods(bool b) {
   672     if (b) {
   673       _misc_flags |= _misc_has_default_methods;
   674     } else {
   675       _misc_flags &= ~_misc_has_default_methods;
   676     }
   677   }
   679   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
   680   inline u2 next_method_idnum();
   681   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
   683   // generics support
   684   Symbol* generic_signature() const                   {
   685     return (_generic_signature_index == 0) ?
   686       (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
   687   }
   688   u2 generic_signature_index() const                  {
   689     return _generic_signature_index;
   690   }
   691   void set_generic_signature_index(u2 sig_index)      {
   692     _generic_signature_index = sig_index;
   693   }
   695   u2 enclosing_method_data(int offset);
   696   u2 enclosing_method_class_index() {
   697     return enclosing_method_data(enclosing_method_class_index_offset);
   698   }
   699   u2 enclosing_method_method_index() {
   700     return enclosing_method_data(enclosing_method_method_index_offset);
   701   }
   702   void set_enclosing_method_indices(u2 class_index,
   703                                     u2 method_index);
   705   // jmethodID support
   706   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
   707                      methodHandle method_h);
   708   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
   709                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
   710                      jmethodID* to_dealloc_id_p,
   711                      jmethodID** to_dealloc_jmeths_p);
   712   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
   713                 size_t *length_p, jmethodID* id_p);
   714   jmethodID jmethod_id_or_null(Method* method);
   716   // annotations support
   717   Annotations* annotations() const          { return _annotations; }
   718   void set_annotations(Annotations* anno)   { _annotations = anno; }
   720   AnnotationArray* class_annotations() const {
   721     return (_annotations != NULL) ? _annotations->class_annotations() : NULL;
   722   }
   723   Array<AnnotationArray*>* fields_annotations() const {
   724     return (_annotations != NULL) ? _annotations->fields_annotations() : NULL;
   725   }
   726   AnnotationArray* class_type_annotations() const {
   727     return (_annotations != NULL) ? _annotations->class_type_annotations() : NULL;
   728   }
   729   Array<AnnotationArray*>* fields_type_annotations() const {
   730     return (_annotations != NULL) ? _annotations->fields_type_annotations() : NULL;
   731   }
   732   // allocation
   733   instanceOop allocate_instance(TRAPS);
   735   // additional member function to return a handle
   736   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
   738   objArrayOop allocate_objArray(int n, int length, TRAPS);
   739   // Helper function
   740   static instanceOop register_finalizer(instanceOop i, TRAPS);
   742   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
   743   // if not, throw either an Error or an Exception.
   744   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
   746   // initialization
   747   void call_class_initializer(TRAPS);
   748   void set_initialization_state_and_notify(ClassState state, TRAPS);
   750   // OopMapCache support
   751   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
   752   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
   753   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
   755   // JNI identifier support (for static fields - for jni performance)
   756   JNIid* jni_ids()                               { return _jni_ids; }
   757   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
   758   JNIid* jni_id_for(int offset);
   760   // maintenance of deoptimization dependencies
   761   int mark_dependent_nmethods(DepChange& changes);
   762   void add_dependent_nmethod(nmethod* nm);
   763   void remove_dependent_nmethod(nmethod* nm);
   765   // On-stack replacement support
   766   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
   767   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
   768   void add_osr_nmethod(nmethod* n);
   769   void remove_osr_nmethod(nmethod* n);
   770   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
   772   // Breakpoint support (see methods on Method* for details)
   773   BreakpointInfo* breakpoints() const       { return _breakpoints; };
   774   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
   776   // support for stub routines
   777   static ByteSize init_state_offset()  { return in_ByteSize(offset_of(InstanceKlass, _init_state)); }
   778   TRACE_DEFINE_OFFSET;
   779   static ByteSize init_thread_offset() { return in_ByteSize(offset_of(InstanceKlass, _init_thread)); }
   781   // subclass/subinterface checks
   782   bool implements_interface(Klass* k) const;
   783   bool is_same_or_direct_interface(Klass* k) const;
   785   // Access to the implementor of an interface.
   786   Klass* implementor() const
   787   {
   788     Klass** k = adr_implementor();
   789     if (k == NULL) {
   790       return NULL;
   791     } else {
   792       return *k;
   793     }
   794   }
   796   void set_implementor(Klass* k) {
   797     assert(is_interface(), "not interface");
   798     Klass** addr = adr_implementor();
   799     assert(addr != NULL, "null addr");
   800     if (addr != NULL) {
   801       *addr = k;
   802     }
   803   }
   805   int  nof_implementors() const       {
   806     Klass* k = implementor();
   807     if (k == NULL) {
   808       return 0;
   809     } else if (k != this) {
   810       return 1;
   811     } else {
   812       return 2;
   813     }
   814   }
   816   void add_implementor(Klass* k);  // k is a new class that implements this interface
   817   void init_implementor();           // initialize
   819   // link this class into the implementors list of every interface it implements
   820   void process_interfaces(Thread *thread);
   822   // virtual operations from Klass
   823   bool is_leaf_class() const               { return _subklass == NULL; }
   824   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
   825   bool compute_is_subtype_of(Klass* k);
   826   bool can_be_primary_super_slow() const;
   827   int oop_size(oop obj)  const             { return size_helper(); }
   828   bool oop_is_instance_slow() const        { return true; }
   830   // Iterators
   831   void do_local_static_fields(FieldClosure* cl);
   832   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
   833   void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
   835   void methods_do(void f(Method* method));
   836   void array_klasses_do(void f(Klass* k));
   837   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
   838   bool super_types_do(SuperTypeClosure* blk);
   840   // Casting from Klass*
   841   static InstanceKlass* cast(Klass* k) {
   842     assert(k->is_klass(), "must be");
   843     assert(k->oop_is_instance(), "cast to InstanceKlass");
   844     return (InstanceKlass*) k;
   845   }
   847   InstanceKlass* java_super() const {
   848     return (super() == NULL) ? NULL : cast(super());
   849   }
   851   // Sizing (in words)
   852   static int header_size()            { return align_object_offset(sizeof(InstanceKlass)/HeapWordSize); }
   854   static int size(int vtable_length, int itable_length,
   855                   int nonstatic_oop_map_size,
   856                   bool is_interface, bool is_anonymous) {
   857     return align_object_size(header_size() +
   858            align_object_offset(vtable_length) +
   859            align_object_offset(itable_length) +
   860            ((is_interface || is_anonymous) ?
   861              align_object_offset(nonstatic_oop_map_size) :
   862              nonstatic_oop_map_size) +
   863            (is_interface ? (int)sizeof(Klass*)/HeapWordSize : 0) +
   864            (is_anonymous ? (int)sizeof(Klass*)/HeapWordSize : 0));
   865   }
   866   int size() const                    { return size(vtable_length(),
   867                                                itable_length(),
   868                                                nonstatic_oop_map_size(),
   869                                                is_interface(),
   870                                                is_anonymous());
   871   }
   872 #if INCLUDE_SERVICES
   873   virtual void collect_statistics(KlassSizeStats *sz) const;
   874 #endif
   876   static int vtable_start_offset()    { return header_size(); }
   877   static int vtable_length_offset()   { return offset_of(InstanceKlass, _vtable_len) / HeapWordSize; }
   879   intptr_t* start_of_vtable() const        { return ((intptr_t*)this) + vtable_start_offset(); }
   880   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
   881   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)this; }
   883   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
   885   address static_field_addr(int offset);
   887   OopMapBlock* start_of_nonstatic_oop_maps() const {
   888     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
   889   }
   891   Klass** end_of_nonstatic_oop_maps() const {
   892     return (Klass**)(start_of_nonstatic_oop_maps() +
   893                      nonstatic_oop_map_count());
   894   }
   896   Klass** adr_implementor() const {
   897     if (is_interface()) {
   898       return (Klass**)end_of_nonstatic_oop_maps();
   899     } else {
   900       return NULL;
   901     }
   902   };
   904   Klass** adr_host_klass() const {
   905     if (is_anonymous()) {
   906       Klass** adr_impl = adr_implementor();
   907       if (adr_impl != NULL) {
   908         return adr_impl + 1;
   909       } else {
   910         return end_of_nonstatic_oop_maps();
   911       }
   912     } else {
   913       return NULL;
   914     }
   915   }
   917   // Use this to return the size of an instance in heap words:
   918   int size_helper() const {
   919     return layout_helper_to_size_helper(layout_helper());
   920   }
   922   // This bit is initialized in classFileParser.cpp.
   923   // It is false under any of the following conditions:
   924   //  - the class is abstract (including any interface)
   925   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
   926   //  - the class size is larger than FastAllocateSizeLimit
   927   //  - the class is java/lang/Class, which cannot be allocated directly
   928   bool can_be_fastpath_allocated() const {
   929     return !layout_helper_needs_slow_path(layout_helper());
   930   }
   932   // Java vtable/itable
   933   klassVtable* vtable() const;        // return new klassVtable wrapper
   934   inline Method* method_at_vtable(int index);
   935   klassItable* itable() const;        // return new klassItable wrapper
   936   Method* method_at_itable(Klass* holder, int index, TRAPS);
   938 #if INCLUDE_JVMTI
   939   void adjust_default_methods(Method** old_methods, Method** new_methods,
   940                               int methods_length, bool* trace_name_printed);
   941 #endif // INCLUDE_JVMTI
   943   // Garbage collection
   944   void oop_follow_contents(oop obj);
   945   int  oop_adjust_pointers(oop obj);
   947   void clean_implementors_list(BoolObjectClosure* is_alive);
   948   void clean_method_data(BoolObjectClosure* is_alive);
   950   // Explicit metaspace deallocation of fields
   951   // For RedefineClasses and class file parsing errors, we need to deallocate
   952   // instanceKlasses and the metadata they point to.
   953   void deallocate_contents(ClassLoaderData* loader_data);
   954   static void deallocate_methods(ClassLoaderData* loader_data,
   955                                  Array<Method*>* methods);
   956   void static deallocate_interfaces(ClassLoaderData* loader_data,
   957                                     Klass* super_klass,
   958                                     Array<Klass*>* local_interfaces,
   959                                     Array<Klass*>* transitive_interfaces);
   961   // The constant pool is on stack if any of the methods are executing or
   962   // referenced by handles.
   963   bool on_stack() const { return _constants->on_stack(); }
   965   // callbacks for actions during class unloading
   966   static void notify_unload_class(InstanceKlass* ik);
   967   static void release_C_heap_structures(InstanceKlass* ik);
   969   // Parallel Scavenge and Parallel Old
   970   PARALLEL_GC_DECLS
   972   // Naming
   973   const char* signature_name() const;
   975   // Iterators
   976   int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
   977     return oop_oop_iterate_v(obj, blk);
   978   }
   980   int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
   981     return oop_oop_iterate_v_m(obj, blk, mr);
   982   }
   984 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
   985   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
   986   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
   987                                       MemRegion mr);
   989   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
   990   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
   992 #if INCLUDE_ALL_GCS
   993 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
   994   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
   996   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
   997   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
   998 #endif // INCLUDE_ALL_GCS
  1000   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
  1002 private:
  1003   // initialization state
  1004 #ifdef ASSERT
  1005   void set_init_state(ClassState state);
  1006 #else
  1007   void set_init_state(ClassState state) { _init_state = (u1)state; }
  1008 #endif
  1009   void set_rewritten()                  { _misc_flags |= _misc_rewritten; }
  1010   void set_init_thread(Thread *thread)  { _init_thread = thread; }
  1012   // The RedefineClasses() API can cause new method idnums to be needed
  1013   // which will cause the caches to grow. Safety requires different
  1014   // cache management logic if the caches can grow instead of just
  1015   // going from NULL to non-NULL.
  1016   bool idnum_can_increment() const      { return has_been_redefined(); }
  1017   jmethodID* methods_jmethod_ids_acquire() const
  1018          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
  1019   void release_set_methods_jmethod_ids(jmethodID* jmeths)
  1020          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
  1022   // Lock during initialization
  1023 public:
  1024   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
  1025   // Must be one per class and it has to be a VM internal object so java code
  1026   // cannot lock it (like the mirror).
  1027   // It has to be an object not a Mutex because it's held through java calls.
  1028   oop init_lock() const;
  1029 private:
  1030   void fence_and_clear_init_lock();
  1032   // Static methods that are used to implement member methods where an exposed this pointer
  1033   // is needed due to possible GCs
  1034   static bool link_class_impl                           (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
  1035   static bool verify_code                               (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
  1036   static void initialize_impl                           (instanceKlassHandle this_oop, TRAPS);
  1037   static void eager_initialize_impl                     (instanceKlassHandle this_oop);
  1038   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_oop, ClassState state, TRAPS);
  1039   static void call_class_initializer_impl               (instanceKlassHandle this_oop, TRAPS);
  1040   static Klass* array_klass_impl                      (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
  1041   static void do_local_static_fields_impl               (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
  1042   /* jni_id_for_impl for jfieldID only */
  1043   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_oop, int offset);
  1045   // Returns the array class for the n'th dimension
  1046   Klass* array_klass_impl(bool or_null, int n, TRAPS);
  1048   // Returns the array class with this class as element type
  1049   Klass* array_klass_impl(bool or_null, TRAPS);
  1051   // Free CHeap allocated fields.
  1052   void release_C_heap_structures();
  1053 public:
  1054   // CDS support - remove and restore oops from metadata. Oops are not shared.
  1055   virtual void remove_unshareable_info();
  1056   virtual void restore_unshareable_info(TRAPS);
  1058   // jvm support
  1059   jint compute_modifier_flags(TRAPS) const;
  1061   // JSR-292 support
  1062   MemberNameTable* member_names() { return _member_names; }
  1063   void set_member_names(MemberNameTable* member_names) { _member_names = member_names; }
  1064   void add_member_name(int index, Handle member_name);
  1065   oop  get_member_name(int index);
  1067 public:
  1068   // JVMTI support
  1069   jint jvmti_class_status() const;
  1071  public:
  1072   // Printing
  1073 #ifndef PRODUCT
  1074   void print_on(outputStream* st) const;
  1075 #endif
  1076   void print_value_on(outputStream* st) const;
  1078   void oop_print_value_on(oop obj, outputStream* st);
  1080 #ifndef PRODUCT
  1081   void oop_print_on      (oop obj, outputStream* st);
  1083   void print_dependent_nmethods(bool verbose = false);
  1084   bool is_dependent_nmethod(nmethod* nm);
  1085 #endif
  1087   const char* internal_name() const;
  1089   // Verification
  1090   void verify_on(outputStream* st);
  1092   void oop_verify_on(oop obj, outputStream* st);
  1093 };
  1095 inline Method* InstanceKlass::method_at_vtable(int index)  {
  1096 #ifndef PRODUCT
  1097   assert(index >= 0, "valid vtable index");
  1098   if (DebugVtables) {
  1099     verify_vtable_index(index);
  1101 #endif
  1102   vtableEntry* ve = (vtableEntry*)start_of_vtable();
  1103   return ve[index].method();
  1106 // for adding methods
  1107 // UNSET_IDNUM return means no more ids available
  1108 inline u2 InstanceKlass::next_method_idnum() {
  1109   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
  1110     return ConstMethod::UNSET_IDNUM; // no more ids available
  1111   } else {
  1112     return _idnum_allocated_count++;
  1117 /* JNIid class for jfieldIDs only */
  1118 class JNIid: public CHeapObj<mtClass> {
  1119   friend class VMStructs;
  1120  private:
  1121   Klass*             _holder;
  1122   JNIid*             _next;
  1123   int                _offset;
  1124 #ifdef ASSERT
  1125   bool               _is_static_field_id;
  1126 #endif
  1128  public:
  1129   // Accessors
  1130   Klass* holder() const           { return _holder; }
  1131   int offset() const              { return _offset; }
  1132   JNIid* next()                   { return _next; }
  1133   // Constructor
  1134   JNIid(Klass* holder, int offset, JNIid* next);
  1135   // Identifier lookup
  1136   JNIid* find(int offset);
  1138   bool find_local_field(fieldDescriptor* fd) {
  1139     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
  1142   static void deallocate(JNIid* id);
  1143   // Debugging
  1144 #ifdef ASSERT
  1145   bool is_static_field_id() const { return _is_static_field_id; }
  1146   void set_is_static_field_id()   { _is_static_field_id = true; }
  1147 #endif
  1148   void verify(Klass* holder);
  1149 };
  1152 // If breakpoints are more numerous than just JVMTI breakpoints,
  1153 // consider compressing this data structure.
  1154 // It is currently a simple linked list defined in method.hpp.
  1156 class BreakpointInfo;
  1159 // A collection point for interesting information about the previous
  1160 // version(s) of an InstanceKlass.  A GrowableArray of PreviousVersionNodes
  1161 // is attached to the InstanceKlass as needed. See PreviousVersionWalker below.
  1162 class PreviousVersionNode : public CHeapObj<mtClass> {
  1163  private:
  1164   ConstantPool*    _prev_constant_pool;
  1166   // If the previous version of the InstanceKlass doesn't have any
  1167   // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
  1168   // EMCP methods have been collected, then _prev_EMCP_methods can
  1169   // have a length of zero.
  1170   GrowableArray<Method*>* _prev_EMCP_methods;
  1172 public:
  1173   PreviousVersionNode(ConstantPool* prev_constant_pool,
  1174                       GrowableArray<Method*>* prev_EMCP_methods);
  1175   ~PreviousVersionNode();
  1176   ConstantPool* prev_constant_pool() const {
  1177     return _prev_constant_pool;
  1179   GrowableArray<Method*>* prev_EMCP_methods() const {
  1180     return _prev_EMCP_methods;
  1182 };
  1185 // Helper object for walking previous versions.
  1186 class PreviousVersionWalker : public StackObj {
  1187  private:
  1188   Thread*                               _thread;
  1189   GrowableArray<PreviousVersionNode *>* _previous_versions;
  1190   int                                   _current_index;
  1192   // A pointer to the current node object so we can handle the deletes.
  1193   PreviousVersionNode*                  _current_p;
  1195   // The constant pool handle keeps all the methods in this class from being
  1196   // deallocated from the metaspace during class unloading.
  1197   constantPoolHandle                    _current_constant_pool_handle;
  1199  public:
  1200   PreviousVersionWalker(Thread* thread, InstanceKlass *ik);
  1202   // Return the interesting information for the next previous version
  1203   // of the klass. Returns NULL if there are no more previous versions.
  1204   PreviousVersionNode* next_previous_version();
  1205 };
  1208 //
  1209 // nmethodBucket is used to record dependent nmethods for
  1210 // deoptimization.  nmethod dependencies are actually <klass, method>
  1211 // pairs but we really only care about the klass part for purposes of
  1212 // finding nmethods which might need to be deoptimized.  Instead of
  1213 // recording the method, a count of how many times a particular nmethod
  1214 // was recorded is kept.  This ensures that any recording errors are
  1215 // noticed since an nmethod should be removed as many times are it's
  1216 // added.
  1217 //
  1218 class nmethodBucket: public CHeapObj<mtClass> {
  1219   friend class VMStructs;
  1220  private:
  1221   nmethod*       _nmethod;
  1222   int            _count;
  1223   nmethodBucket* _next;
  1225  public:
  1226   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
  1227     _nmethod = nmethod;
  1228     _next = next;
  1229     _count = 1;
  1231   int count()                             { return _count; }
  1232   int increment()                         { _count += 1; return _count; }
  1233   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
  1234   nmethodBucket* next()                   { return _next; }
  1235   void set_next(nmethodBucket* b)         { _next = b; }
  1236   nmethod* get_nmethod()                  { return _nmethod; }
  1237 };
  1239 // An iterator that's used to access the inner classes indices in the
  1240 // InstanceKlass::_inner_classes array.
  1241 class InnerClassesIterator : public StackObj {
  1242  private:
  1243   Array<jushort>* _inner_classes;
  1244   int _length;
  1245   int _idx;
  1246  public:
  1248   InnerClassesIterator(instanceKlassHandle k) {
  1249     _inner_classes = k->inner_classes();
  1250     if (k->inner_classes() != NULL) {
  1251       _length = _inner_classes->length();
  1252       // The inner class array's length should be the multiple of
  1253       // inner_class_next_offset if it only contains the InnerClasses
  1254       // attribute data, or it should be
  1255       // n*inner_class_next_offset+enclosing_method_attribute_size
  1256       // if it also contains the EnclosingMethod data.
  1257       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
  1258               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
  1259              "just checking");
  1260       // Remove the enclosing_method portion if exists.
  1261       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
  1262         _length -= InstanceKlass::enclosing_method_attribute_size;
  1264     } else {
  1265       _length = 0;
  1267     _idx = 0;
  1270   int length() const {
  1271     return _length;
  1274   void next() {
  1275     _idx += InstanceKlass::inner_class_next_offset;
  1278   bool done() const {
  1279     return (_idx >= _length);
  1282   u2 inner_class_info_index() const {
  1283     return _inner_classes->at(
  1284                _idx + InstanceKlass::inner_class_inner_class_info_offset);
  1287   void set_inner_class_info_index(u2 index) {
  1288     _inner_classes->at_put(
  1289                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
  1292   u2 outer_class_info_index() const {
  1293     return _inner_classes->at(
  1294                _idx + InstanceKlass::inner_class_outer_class_info_offset);
  1297   void set_outer_class_info_index(u2 index) {
  1298     _inner_classes->at_put(
  1299                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
  1302   u2 inner_name_index() const {
  1303     return _inner_classes->at(
  1304                _idx + InstanceKlass::inner_class_inner_name_offset);
  1307   void set_inner_name_index(u2 index) {
  1308     _inner_classes->at_put(
  1309                _idx + InstanceKlass::inner_class_inner_name_offset, index);
  1312   u2 inner_access_flags() const {
  1313     return _inner_classes->at(
  1314                _idx + InstanceKlass::inner_class_access_flags_offset);
  1316 };
  1318 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP

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