src/share/vm/oops/instanceKlass.hpp

Tue, 13 Mar 2012 13:50:48 -0400

author
jiangli
date
Tue, 13 Mar 2012 13:50:48 -0400
changeset 3670
f7c4174b33ba
parent 3528
b7b8b6d2f97d
child 3701
49036505ab5f
child 3743
c7ed11779ce8
permissions
-rw-r--r--

7109878: The instanceKlass EnclosingMethhod attribute fields can be folded into the _inner_class field.
Summary: Fold instanceKlass::_enclosing_method_class_index and instanceKlass::_enclosing_method_method_index into the instanceKlass::_inner_classes array.
Reviewed-by: never, coleenp
Contributed-by: Jiangli Zhou <jiangli.zhou@oracle.com>

     1 /*
     2  * Copyright (c) 1997, 2011, 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 "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"
    40 // An instanceKlass is the VM level representation of a Java class.
    41 // It contains all information needed for at class at execution runtime.
    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 //    [number of implementors     ]
    60 //    [implementors               ] klassOop[2]
    61 //    [fields                     ]
    62 //    [constants                  ]
    63 //    [class loader               ]
    64 //    [protection domain          ]
    65 //    [signers                    ]
    66 //    [source file name           ]
    67 //    [inner classes              ]
    68 //    [static field size          ]
    69 //    [nonstatic field size       ]
    70 //    [static oop fields size     ]
    71 //    [nonstatic oop maps size    ]
    72 //    [has finalize method        ]
    73 //    [deoptimization mark bit    ]
    74 //    [initialization state       ]
    75 //    [initializing thread        ]
    76 //    [Java vtable length         ]
    77 //    [oop map cache (stack maps) ]
    78 //    [EMBEDDED Java vtable             ] size in words = vtable_len
    79 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
    80 //
    81 //    The embedded nonstatic oop-map blocks are short pairs (offset, length) indicating
    82 //    where oops are located in instances of this klass.
    85 // forward declaration for class -- see below for definition
    86 class SuperTypeClosure;
    87 class JNIid;
    88 class jniIdMapBase;
    89 class BreakpointInfo;
    90 class fieldDescriptor;
    91 class DepChange;
    92 class nmethodBucket;
    93 class PreviousVersionNode;
    94 class JvmtiCachedClassFieldMap;
    96 // This is used in iterators below.
    97 class FieldClosure: public StackObj {
    98 public:
    99   virtual void do_field(fieldDescriptor* fd) = 0;
   100 };
   102 #ifndef PRODUCT
   103 // Print fields.
   104 // If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.
   105 class FieldPrinter: public FieldClosure {
   106    oop _obj;
   107    outputStream* _st;
   108  public:
   109    FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}
   110    void do_field(fieldDescriptor* fd);
   111 };
   112 #endif  // !PRODUCT
   114 // ValueObjs embedded in klass. Describes where oops are located in instances of
   115 // this klass.
   116 class OopMapBlock VALUE_OBJ_CLASS_SPEC {
   117  public:
   118   // Byte offset of the first oop mapped by this block.
   119   int offset() const          { return _offset; }
   120   void set_offset(int offset) { _offset = offset; }
   122   // Number of oops in this block.
   123   uint count() const         { return _count; }
   124   void set_count(uint count) { _count = count; }
   126   // sizeof(OopMapBlock) in HeapWords.
   127   static const int size_in_words() {
   128     return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>
   129       LogHeapWordSize;
   130   }
   132  private:
   133   int  _offset;
   134   uint _count;
   135 };
   137 class instanceKlass: public Klass {
   138   friend class VMStructs;
   139  public:
   140   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
   141   // of the class loading & initialization procedure, and the use of the states.
   142   enum ClassState {
   143     unparsable_by_gc = 0,               // object is not yet parsable by gc. Value of _init_state at object allocation.
   144     allocated,                          // allocated (but not yet linked)
   145     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
   146     linked,                             // successfully linked/verified (but not initialized yet)
   147     being_initialized,                  // currently running class initializer
   148     fully_initialized,                  // initialized (successfull final state)
   149     initialization_error                // error happened during initialization
   150   };
   152  public:
   153   oop* oop_block_beg() const { return adr_array_klasses(); }
   154   oop* oop_block_end() const { return adr_methods_default_annotations() + 1; }
   156   enum {
   157     implementors_limit = 2              // how many implems can we track?
   158   };
   160  protected:
   161   //
   162   // The oop block.  See comment in klass.hpp before making changes.
   163   //
   165   // Array classes holding elements of this class.
   166   klassOop        _array_klasses;
   167   // Method array.
   168   objArrayOop     _methods;
   169   // Int array containing the original order of method in the class file (for
   170   // JVMTI).
   171   typeArrayOop    _method_ordering;
   172   // Interface (klassOops) this class declares locally to implement.
   173   objArrayOop     _local_interfaces;
   174   // Interface (klassOops) this class implements transitively.
   175   objArrayOop     _transitive_interfaces;
   176   // Instance and static variable information, 5-tuples of shorts [access, name
   177   // index, sig index, initval index, offset].
   178   typeArrayOop    _fields;
   179   // Constant pool for this class.
   180   constantPoolOop _constants;
   181   // Class loader used to load this class, NULL if VM loader used.
   182   oop             _class_loader;
   183   // Protection domain.
   184   oop             _protection_domain;
   185   // Host class, which grants its access privileges to this class also.
   186   // This is only non-null for an anonymous class (JSR 292 enabled).
   187   // The host class is either named, or a previously loaded anonymous class.
   188   klassOop        _host_klass;
   189   // Class signers.
   190   objArrayOop     _signers;
   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   typeArrayOop    _inner_classes;
   203   // Implementors of this interface (not valid if it overflows)
   204   klassOop        _implementors[implementors_limit];
   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;
   222   //
   223   // End of the oop block.
   224   //
   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;
   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
   244   bool            _is_marked_dependent;  // used for marking during flushing and deoptimization
   245   bool            _rewritten;            // methods rewritten.
   246   bool            _has_nonstatic_fields; // for sizing with UseCompressedOops
   247   bool            _should_verify_class;  // allow caching of preverification
   248   u2              _minor_version;        // minor version number of class file
   249   u2              _major_version;        // major version number of class file
   250   Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)
   251   int             _vtable_len;           // length of Java vtable (in words)
   252   int             _itable_len;           // length of Java itable (in words)
   253   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
   254   JNIid*          _jni_ids;              // First JNI identifier for static fields in this class
   255   jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none
   256   int*            _methods_cached_itable_indices;  // itable_index cache for JNI invoke corresponding to methods idnum, or NULL
   257   nmethodBucket*  _dependencies;         // list of dependent nmethods
   258   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
   259   BreakpointInfo* _breakpoints;          // bpt lists, managed by methodOop
   260   int             _nof_implementors;     // No of implementors of this interface (zero if not an interface)
   261   // Array of interesting part(s) of the previous version(s) of this
   262   // instanceKlass. See PreviousVersionWalker below.
   263   GrowableArray<PreviousVersionNode *>* _previous_versions;
   264   // JVMTI fields can be moved to their own structure - see 6315920
   265   unsigned char * _cached_class_file_bytes;       // JVMTI: cached class file, before retransformable agent modified it in CFLH
   266   jint            _cached_class_file_len;         // JVMTI: length of above
   267   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
   268   volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change
   270   // Class states are defined as ClassState (see above).
   271   // Place the _init_state here to utilize the unused 2-byte after
   272   // _idnum_allocated_count.
   273   u1              _init_state;                    // state of class
   275   u1              _reference_type;                // reference type
   277   // embedded Java vtable follows here
   278   // embedded Java itables follows here
   279   // embedded static fields follows here
   280   // embedded nonstatic oop-map blocks follows here
   282   friend class instanceKlassKlass;
   283   friend class SystemDictionary;
   285  public:
   286   bool has_nonstatic_fields() const        { return _has_nonstatic_fields; }
   287   void set_has_nonstatic_fields(bool b)    { _has_nonstatic_fields = b; }
   289   // field sizes
   290   int nonstatic_field_size() const         { return _nonstatic_field_size; }
   291   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
   293   int static_field_size() const            { return _static_field_size; }
   294   void set_static_field_size(int size)     { _static_field_size = size; }
   296   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
   297   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
   299   // Java vtable
   300   int  vtable_length() const               { return _vtable_len; }
   301   void set_vtable_length(int len)          { _vtable_len = len; }
   303   // Java itable
   304   int  itable_length() const               { return _itable_len; }
   305   void set_itable_length(int len)          { _itable_len = len; }
   307   // array klasses
   308   klassOop array_klasses() const           { return _array_klasses; }
   309   void set_array_klasses(klassOop k)       { oop_store_without_check((oop*) &_array_klasses, (oop) k); }
   311   // methods
   312   objArrayOop methods() const              { return _methods; }
   313   void set_methods(objArrayOop a)          { oop_store_without_check((oop*) &_methods, (oop) a); }
   314   methodOop method_with_idnum(int idnum);
   316   // method ordering
   317   typeArrayOop method_ordering() const     { return _method_ordering; }
   318   void set_method_ordering(typeArrayOop m) { oop_store_without_check((oop*) &_method_ordering, (oop) m); }
   320   // interfaces
   321   objArrayOop local_interfaces() const          { return _local_interfaces; }
   322   void set_local_interfaces(objArrayOop a)      { oop_store_without_check((oop*) &_local_interfaces, (oop) a); }
   323   objArrayOop transitive_interfaces() const     { return _transitive_interfaces; }
   324   void set_transitive_interfaces(objArrayOop a) { oop_store_without_check((oop*) &_transitive_interfaces, (oop) a); }
   326  private:
   327   friend class fieldDescriptor;
   328   FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }
   330  public:
   331   int     field_offset      (int index) const { return field(index)->offset(); }
   332   int     field_access_flags(int index) const { return field(index)->access_flags(); }
   333   Symbol* field_name        (int index) const { return field(index)->name(constants()); }
   334   Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }
   336   // Number of Java declared fields
   337   int java_fields_count() const           { return (int)_java_fields_count; }
   339   // Number of fields including any injected fields
   340   int all_fields_count() const            { return _fields->length() / sizeof(FieldInfo::field_slots); }
   342   typeArrayOop fields() const              { return _fields; }
   344   void set_fields(typeArrayOop f, u2 java_fields_count) {
   345     oop_store_without_check((oop*) &_fields, (oop) f);
   346     _java_fields_count = java_fields_count;
   347   }
   349   // inner classes
   350   typeArrayOop inner_classes() const       { return _inner_classes; }
   351   void set_inner_classes(typeArrayOop f)   { oop_store_without_check((oop*) &_inner_classes, (oop) f); }
   353   enum InnerClassAttributeOffset {
   354     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
   355     inner_class_inner_class_info_offset = 0,
   356     inner_class_outer_class_info_offset = 1,
   357     inner_class_inner_name_offset = 2,
   358     inner_class_access_flags_offset = 3,
   359     inner_class_next_offset = 4
   360   };
   362   enum EnclosingMethodAttributeOffset {
   363     enclosing_method_class_index_offset = 0,
   364     enclosing_method_method_index_offset = 1,
   365     enclosing_method_attribute_size = 2
   366   };
   368   // method override check
   369   bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);
   371   // package
   372   bool is_same_class_package(klassOop class2);
   373   bool is_same_class_package(oop classloader2, Symbol* classname2);
   374   static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);
   376   // find an enclosing class (defined where original code was, in jvm.cpp!)
   377   klassOop compute_enclosing_class(bool* inner_is_member, TRAPS) {
   378     instanceKlassHandle self(THREAD, this->as_klassOop());
   379     return compute_enclosing_class_impl(self, inner_is_member, THREAD);
   380   }
   381   static klassOop compute_enclosing_class_impl(instanceKlassHandle self,
   382                                                bool* inner_is_member, TRAPS);
   384   // tell if two classes have the same enclosing class (at package level)
   385   bool is_same_package_member(klassOop class2, TRAPS) {
   386     instanceKlassHandle self(THREAD, this->as_klassOop());
   387     return is_same_package_member_impl(self, class2, THREAD);
   388   }
   389   static bool is_same_package_member_impl(instanceKlassHandle self,
   390                                           klassOop class2, TRAPS);
   392   // initialization state
   393   bool is_loaded() const                   { return _init_state >= loaded; }
   394   bool is_linked() const                   { return _init_state >= linked; }
   395   bool is_initialized() const              { return _init_state == fully_initialized; }
   396   bool is_not_initialized() const          { return _init_state <  being_initialized; }
   397   bool is_being_initialized() const        { return _init_state == being_initialized; }
   398   bool is_in_error_state() const           { return _init_state == initialization_error; }
   399   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
   400   ClassState  init_state()                 { return (ClassState)_init_state; }
   401   bool is_rewritten() const                { return _rewritten; }
   403   // defineClass specified verification
   404   bool should_verify_class() const         { return _should_verify_class; }
   405   void set_should_verify_class(bool value) { _should_verify_class = value; }
   407   // marking
   408   bool is_marked_dependent() const         { return _is_marked_dependent; }
   409   void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
   411   // initialization (virtuals from Klass)
   412   bool should_be_initialized() const;  // means that initialize should be called
   413   void initialize(TRAPS);
   414   void link_class(TRAPS);
   415   bool link_class_or_fail(TRAPS); // returns false on failure
   416   void unlink_class();
   417   void rewrite_class(TRAPS);
   418   void relocate_and_link_methods(TRAPS);
   419   methodOop class_initializer();
   421   // set the class to initialized if no static initializer is present
   422   void eager_initialize(Thread *thread);
   424   // reference type
   425   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
   426   void set_reference_type(ReferenceType t) {
   427     assert(t == (u1)t, "overflow");
   428     _reference_type = (u1)t;
   429   }
   431   static ByteSize reference_type_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _reference_type)); }
   433   // find local field, returns true if found
   434   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   435   // find field in direct superinterfaces, returns the interface in which the field is defined
   436   klassOop find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   437   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
   438   klassOop find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   439   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
   440   klassOop find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
   442   // find a non-static or static field given its offset within the class.
   443   bool contains_field_offset(int offset) {
   444     return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());
   445   }
   447   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
   448   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
   450   // find a local method (returns NULL if not found)
   451   methodOop find_method(Symbol* name, Symbol* signature) const;
   452   static methodOop find_method(objArrayOop methods, Symbol* name, Symbol* signature);
   454   // lookup operation (returns NULL if not found)
   455   methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;
   457   // lookup a method in all the interfaces that this class implements
   458   // (returns NULL if not found)
   459   methodOop lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;
   461   // constant pool
   462   constantPoolOop constants() const        { return _constants; }
   463   void set_constants(constantPoolOop c)    { oop_store_without_check((oop*) &_constants, (oop) c); }
   465   // class loader
   466   oop class_loader() const                 { return _class_loader; }
   467   void set_class_loader(oop l)             { oop_store((oop*) &_class_loader, l); }
   469   // protection domain
   470   oop protection_domain()                  { return _protection_domain; }
   471   void set_protection_domain(oop pd)       { oop_store((oop*) &_protection_domain, pd); }
   473   // host class
   474   oop host_klass() const                   { return _host_klass; }
   475   void set_host_klass(oop host)            { oop_store((oop*) &_host_klass, host); }
   476   bool is_anonymous() const                { return _host_klass != NULL; }
   478   // signers
   479   objArrayOop signers() const              { return _signers; }
   480   void set_signers(objArrayOop s)          { oop_store((oop*) &_signers, oop(s)); }
   482   // source file name
   483   Symbol* source_file_name() const         { return _source_file_name; }
   484   void set_source_file_name(Symbol* n);
   486   // minor and major version numbers of class file
   487   u2 minor_version() const                 { return _minor_version; }
   488   void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
   489   u2 major_version() const                 { return _major_version; }
   490   void set_major_version(u2 major_version) { _major_version = major_version; }
   492   // source debug extension
   493   Symbol* source_debug_extension() const   { return _source_debug_extension; }
   494   void set_source_debug_extension(Symbol* n);
   496   // symbol unloading support (refcount already added)
   497   Symbol* array_name()                     { return _array_name; }
   498   void set_array_name(Symbol* name)        { assert(_array_name == NULL, "name already created"); _array_name = name; }
   500   // nonstatic oop-map blocks
   501   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
   502     return oop_map_count * OopMapBlock::size_in_words();
   503   }
   504   unsigned int nonstatic_oop_map_count() const {
   505     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
   506   }
   507   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
   508   void set_nonstatic_oop_map_size(int words) {
   509     _nonstatic_oop_map_size = words;
   510   }
   512   // RedefineClasses() support for previous versions:
   513   void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
   514          int emcp_method_count);
   515   // If the _previous_versions array is non-NULL, then this klass
   516   // has been redefined at least once even if we aren't currently
   517   // tracking a previous version.
   518   bool has_been_redefined() const { return _previous_versions != NULL; }
   519   bool has_previous_version() const;
   520   void init_previous_versions() {
   521     _previous_versions = NULL;
   522   }
   523   GrowableArray<PreviousVersionNode *>* previous_versions() const {
   524     return _previous_versions;
   525   }
   527   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
   528   void set_cached_class_file(unsigned char *class_file_bytes,
   529                              jint class_file_len)     { _cached_class_file_len = class_file_len;
   530                                                         _cached_class_file_bytes = class_file_bytes; }
   531   jint get_cached_class_file_len()                    { return _cached_class_file_len; }
   532   unsigned char * get_cached_class_file_bytes()       { return _cached_class_file_bytes; }
   534   // JVMTI: Support for caching of field indices, types, and offsets
   535   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
   536     _jvmti_cached_class_field_map = descriptor;
   537   }
   538   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
   539     return _jvmti_cached_class_field_map;
   540   }
   542   // for adding methods, constMethodOopDesc::UNSET_IDNUM means no more ids available
   543   inline u2 next_method_idnum();
   544   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
   546   // generics support
   547   Symbol* generic_signature() const                   { return _generic_signature; }
   548   void set_generic_signature(Symbol* sig)             { _generic_signature = sig; }
   550   u2 enclosing_method_data(int offset);
   551   u2 enclosing_method_class_index() {
   552     return enclosing_method_data(enclosing_method_class_index_offset);
   553   }
   554   u2 enclosing_method_method_index() {
   555     return enclosing_method_data(enclosing_method_method_index_offset);
   556   }
   557   void set_enclosing_method_indices(u2 class_index,
   558                                     u2 method_index);
   560   // jmethodID support
   561   static jmethodID get_jmethod_id(instanceKlassHandle ik_h,
   562                      methodHandle method_h);
   563   static jmethodID get_jmethod_id_fetch_or_update(instanceKlassHandle ik_h,
   564                      size_t idnum, jmethodID new_id, jmethodID* new_jmeths,
   565                      jmethodID* to_dealloc_id_p,
   566                      jmethodID** to_dealloc_jmeths_p);
   567   static void get_jmethod_id_length_value(jmethodID* cache, size_t idnum,
   568                 size_t *length_p, jmethodID* id_p);
   569   jmethodID jmethod_id_or_null(methodOop method);
   571   // cached itable index support
   572   void set_cached_itable_index(size_t idnum, int index);
   573   int cached_itable_index(size_t idnum);
   575   // annotations support
   576   typeArrayOop class_annotations() const              { return _class_annotations; }
   577   objArrayOop fields_annotations() const              { return _fields_annotations; }
   578   objArrayOop methods_annotations() const             { return _methods_annotations; }
   579   objArrayOop methods_parameter_annotations() const   { return _methods_parameter_annotations; }
   580   objArrayOop methods_default_annotations() const     { return _methods_default_annotations; }
   581   void set_class_annotations(typeArrayOop md)            { oop_store_without_check((oop*)&_class_annotations, (oop)md); }
   582   void set_fields_annotations(objArrayOop md)            { set_annotations(md, &_fields_annotations); }
   583   void set_methods_annotations(objArrayOop md)           { set_annotations(md, &_methods_annotations); }
   584   void set_methods_parameter_annotations(objArrayOop md) { set_annotations(md, &_methods_parameter_annotations); }
   585   void set_methods_default_annotations(objArrayOop md)   { set_annotations(md, &_methods_default_annotations); }
   586   typeArrayOop get_method_annotations_of(int idnum)
   587                                                 { return get_method_annotations_from(idnum, _methods_annotations); }
   588   typeArrayOop get_method_parameter_annotations_of(int idnum)
   589                                                 { return get_method_annotations_from(idnum, _methods_parameter_annotations); }
   590   typeArrayOop get_method_default_annotations_of(int idnum)
   591                                                 { return get_method_annotations_from(idnum, _methods_default_annotations); }
   592   void set_method_annotations_of(int idnum, typeArrayOop anno)
   593                                                 { set_methods_annotations_of(idnum, anno, &_methods_annotations); }
   594   void set_method_parameter_annotations_of(int idnum, typeArrayOop anno)
   595                                                 { set_methods_annotations_of(idnum, anno, &_methods_parameter_annotations); }
   596   void set_method_default_annotations_of(int idnum, typeArrayOop anno)
   597                                                 { set_methods_annotations_of(idnum, anno, &_methods_default_annotations); }
   599   // allocation
   600   DEFINE_ALLOCATE_PERMANENT(instanceKlass);
   601   instanceOop allocate_instance(TRAPS);
   602   instanceOop allocate_permanent_instance(TRAPS);
   604   // additional member function to return a handle
   605   instanceHandle allocate_instance_handle(TRAPS)      { return instanceHandle(THREAD, allocate_instance(THREAD)); }
   607   objArrayOop allocate_objArray(int n, int length, TRAPS);
   608   // Helper function
   609   static instanceOop register_finalizer(instanceOop i, TRAPS);
   611   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
   612   // if not, throw either an Error or an Exception.
   613   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
   615   // initialization
   616   void call_class_initializer(TRAPS);
   617   void set_initialization_state_and_notify(ClassState state, TRAPS);
   619   // OopMapCache support
   620   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
   621   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
   622   void mask_for(methodHandle method, int bci, InterpreterOopMap* entry);
   624   // JNI identifier support (for static fields - for jni performance)
   625   JNIid* jni_ids()                               { return _jni_ids; }
   626   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
   627   JNIid* jni_id_for(int offset);
   629   // maintenance of deoptimization dependencies
   630   int mark_dependent_nmethods(DepChange& changes);
   631   void add_dependent_nmethod(nmethod* nm);
   632   void remove_dependent_nmethod(nmethod* nm);
   634   // On-stack replacement support
   635   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
   636   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
   637   void add_osr_nmethod(nmethod* n);
   638   void remove_osr_nmethod(nmethod* n);
   639   nmethod* lookup_osr_nmethod(const methodOop m, int bci, int level, bool match_level) const;
   641   // Breakpoint support (see methods on methodOop for details)
   642   BreakpointInfo* breakpoints() const       { return _breakpoints; };
   643   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
   645   // support for stub routines
   646   static ByteSize init_state_offset()  { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_state)); }
   647   static ByteSize init_thread_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _init_thread)); }
   649   // subclass/subinterface checks
   650   bool implements_interface(klassOop k) const;
   652   // Access to implementors of an interface. We only store the count
   653   // of implementors, and in case, there are only a few
   654   // implementors, we store them in a short list.
   655   // This accessor returns NULL if we walk off the end of the list.
   656   klassOop implementor(int i) const {
   657     return (i < implementors_limit)? _implementors[i]: (klassOop) NULL;
   658   }
   659   int  nof_implementors() const       { return _nof_implementors; }
   660   void add_implementor(klassOop k);  // k is a new class that implements this interface
   661   void init_implementor();           // initialize
   663   // link this class into the implementors list of every interface it implements
   664   void process_interfaces(Thread *thread);
   666   // virtual operations from Klass
   667   bool is_leaf_class() const               { return _subklass == NULL; }
   668   objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
   669   bool compute_is_subtype_of(klassOop k);
   670   bool can_be_primary_super_slow() const;
   671   klassOop java_super() const              { return super(); }
   672   int oop_size(oop obj)  const             { return size_helper(); }
   673   int klass_oop_size() const               { return object_size(); }
   674   bool oop_is_instance_slow() const        { return true; }
   676   // Iterators
   677   void do_local_static_fields(FieldClosure* cl);
   678   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
   679   void do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS);
   681   void methods_do(void f(methodOop method));
   682   void array_klasses_do(void f(klassOop k));
   683   void with_array_klasses_do(void f(klassOop k));
   684   bool super_types_do(SuperTypeClosure* blk);
   686   // Casting from klassOop
   687   static instanceKlass* cast(klassOop k) {
   688     assert(k->is_klass(), "must be");
   689     Klass* kp = k->klass_part();
   690     assert(kp->null_vtbl() || kp->oop_is_instance_slow(), "cast to instanceKlass");
   691     return (instanceKlass*) kp;
   692   }
   694   // Sizing (in words)
   695   static int header_size()            { return align_object_offset(oopDesc::header_size() + sizeof(instanceKlass)/HeapWordSize); }
   696   int object_size() const             { return object_size(align_object_offset(vtable_length()) + align_object_offset(itable_length()) + nonstatic_oop_map_size()); }
   697   static int vtable_start_offset()    { return header_size(); }
   698   static int vtable_length_offset()   { return oopDesc::header_size() + offset_of(instanceKlass, _vtable_len) / HeapWordSize; }
   699   static int object_size(int extra)   { return align_object_size(header_size() + extra); }
   701   intptr_t* start_of_vtable() const        { return ((intptr_t*)as_klassOop()) + vtable_start_offset(); }
   702   intptr_t* start_of_itable() const        { return start_of_vtable() + align_object_offset(vtable_length()); }
   703   int  itable_offset_in_words() const { return start_of_itable() - (intptr_t*)as_klassOop(); }
   705   intptr_t* end_of_itable() const          { return start_of_itable() + itable_length(); }
   707   address static_field_addr(int offset);
   709   OopMapBlock* start_of_nonstatic_oop_maps() const {
   710     return (OopMapBlock*)(start_of_itable() + align_object_offset(itable_length()));
   711   }
   713   // Allocation profiling support
   714   juint alloc_size() const            { return _alloc_count * size_helper(); }
   715   void set_alloc_size(juint n)        {}
   717   // Use this to return the size of an instance in heap words:
   718   int size_helper() const {
   719     return layout_helper_to_size_helper(layout_helper());
   720   }
   722   // This bit is initialized in classFileParser.cpp.
   723   // It is false under any of the following conditions:
   724   //  - the class is abstract (including any interface)
   725   //  - the class has a finalizer (if !RegisterFinalizersAtInit)
   726   //  - the class size is larger than FastAllocateSizeLimit
   727   //  - the class is java/lang/Class, which cannot be allocated directly
   728   bool can_be_fastpath_allocated() const {
   729     return !layout_helper_needs_slow_path(layout_helper());
   730   }
   732   // Java vtable/itable
   733   klassVtable* vtable() const;        // return new klassVtable wrapper
   734   inline methodOop method_at_vtable(int index);
   735   klassItable* itable() const;        // return new klassItable wrapper
   736   methodOop method_at_itable(klassOop holder, int index, TRAPS);
   738   // Garbage collection
   739   void oop_follow_contents(oop obj);
   740   int  oop_adjust_pointers(oop obj);
   741   bool object_is_parsable() const { return _init_state != unparsable_by_gc; }
   742        // Value of _init_state must be zero (unparsable_by_gc) when klass field is set.
   744   void follow_weak_klass_links(
   745     BoolObjectClosure* is_alive, OopClosure* keep_alive);
   746   void release_C_heap_structures();
   748   // Parallel Scavenge and Parallel Old
   749   PARALLEL_GC_DECLS
   751   // Naming
   752   const char* signature_name() const;
   754   // Iterators
   755   int oop_oop_iterate(oop obj, OopClosure* blk) {
   756     return oop_oop_iterate_v(obj, blk);
   757   }
   759   int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
   760     return oop_oop_iterate_v_m(obj, blk, mr);
   761   }
   763 #define InstanceKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)      \
   764   int  oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);           \
   765   int  oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk,        \
   766                                       MemRegion mr);
   768   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DECL)
   769   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DECL)
   771 #ifndef SERIALGC
   772 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
   773   int  oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
   775   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
   776   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
   777 #endif // !SERIALGC
   779 private:
   780   // initialization state
   781 #ifdef ASSERT
   782   void set_init_state(ClassState state);
   783 #else
   784   void set_init_state(ClassState state) { _init_state = (u1)state; }
   785 #endif
   786   void set_rewritten()                  { _rewritten = true; }
   787   void set_init_thread(Thread *thread)  { _init_thread = thread; }
   789   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
   790   // The RedefineClasses() API can cause new method idnums to be needed
   791   // which will cause the caches to grow. Safety requires different
   792   // cache management logic if the caches can grow instead of just
   793   // going from NULL to non-NULL.
   794   bool idnum_can_increment() const      { return has_been_redefined(); }
   795   jmethodID* methods_jmethod_ids_acquire() const
   796          { return (jmethodID*)OrderAccess::load_ptr_acquire(&_methods_jmethod_ids); }
   797   void release_set_methods_jmethod_ids(jmethodID* jmeths)
   798          { OrderAccess::release_store_ptr(&_methods_jmethod_ids, jmeths); }
   800   int* methods_cached_itable_indices_acquire() const
   801          { return (int*)OrderAccess::load_ptr_acquire(&_methods_cached_itable_indices); }
   802   void release_set_methods_cached_itable_indices(int* indices)
   803          { OrderAccess::release_store_ptr(&_methods_cached_itable_indices, indices); }
   805   inline typeArrayOop get_method_annotations_from(int idnum, objArrayOop annos);
   806   void set_annotations(objArrayOop md, objArrayOop* md_p)  { oop_store_without_check((oop*)md_p, (oop)md); }
   807   void set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p);
   809   // Offsets for memory management
   810   oop* adr_array_klasses() const     { return (oop*)&this->_array_klasses;}
   811   oop* adr_methods() const           { return (oop*)&this->_methods;}
   812   oop* adr_method_ordering() const   { return (oop*)&this->_method_ordering;}
   813   oop* adr_local_interfaces() const  { return (oop*)&this->_local_interfaces;}
   814   oop* adr_transitive_interfaces() const  { return (oop*)&this->_transitive_interfaces;}
   815   oop* adr_fields() const            { return (oop*)&this->_fields;}
   816   oop* adr_constants() const         { return (oop*)&this->_constants;}
   817   oop* adr_class_loader() const      { return (oop*)&this->_class_loader;}
   818   oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
   819   oop* adr_host_klass() const        { return (oop*)&this->_host_klass;}
   820   oop* adr_signers() const           { return (oop*)&this->_signers;}
   821   oop* adr_inner_classes() const     { return (oop*)&this->_inner_classes;}
   822   oop* adr_implementors() const      { return (oop*)&this->_implementors[0];}
   823   oop* adr_methods_jmethod_ids() const             { return (oop*)&this->_methods_jmethod_ids;}
   824   oop* adr_methods_cached_itable_indices() const   { return (oop*)&this->_methods_cached_itable_indices;}
   825   oop* adr_class_annotations() const   { return (oop*)&this->_class_annotations;}
   826   oop* adr_fields_annotations() const  { return (oop*)&this->_fields_annotations;}
   827   oop* adr_methods_annotations() const { return (oop*)&this->_methods_annotations;}
   828   oop* adr_methods_parameter_annotations() const { return (oop*)&this->_methods_parameter_annotations;}
   829   oop* adr_methods_default_annotations() const { return (oop*)&this->_methods_default_annotations;}
   831   // Static methods that are used to implement member methods where an exposed this pointer
   832   // is needed due to possible GCs
   833   static bool link_class_impl                           (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
   834   static bool verify_code                               (instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS);
   835   static void initialize_impl                           (instanceKlassHandle this_oop, TRAPS);
   836   static void eager_initialize_impl                     (instanceKlassHandle this_oop);
   837   static void set_initialization_state_and_notify_impl  (instanceKlassHandle this_oop, ClassState state, TRAPS);
   838   static void call_class_initializer_impl               (instanceKlassHandle this_oop, TRAPS);
   839   static klassOop array_klass_impl                      (instanceKlassHandle this_oop, bool or_null, int n, TRAPS);
   840   static void do_local_static_fields_impl               (instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS);
   841   /* jni_id_for_impl for jfieldID only */
   842   static JNIid* jni_id_for_impl                         (instanceKlassHandle this_oop, int offset);
   844   // Returns the array class for the n'th dimension
   845   klassOop array_klass_impl(bool or_null, int n, TRAPS);
   847   // Returns the array class with this class as element type
   848   klassOop array_klass_impl(bool or_null, TRAPS);
   850 public:
   851   // sharing support
   852   virtual void remove_unshareable_info();
   853   virtual void shared_symbols_iterate(SymbolClosure* closure);
   855   // jvm support
   856   jint compute_modifier_flags(TRAPS) const;
   858 public:
   859   // JVMTI support
   860   jint jvmti_class_status() const;
   862  public:
   863   // Printing
   864   void oop_print_value_on(oop obj, outputStream* st);
   865 #ifndef PRODUCT
   866   void oop_print_on      (oop obj, outputStream* st);
   868   void print_dependent_nmethods(bool verbose = false);
   869   bool is_dependent_nmethod(nmethod* nm);
   870 #endif
   872   // Verification
   873   const char* internal_name() const;
   874   void oop_verify_on(oop obj, outputStream* st);
   875 };
   877 inline methodOop instanceKlass::method_at_vtable(int index)  {
   878 #ifndef PRODUCT
   879   assert(index >= 0, "valid vtable index");
   880   if (DebugVtables) {
   881     verify_vtable_index(index);
   882   }
   883 #endif
   884   vtableEntry* ve = (vtableEntry*)start_of_vtable();
   885   return ve[index].method();
   886 }
   888 inline typeArrayOop instanceKlass::get_method_annotations_from(int idnum, objArrayOop annos) {
   889   if (annos == NULL || annos->length() <= idnum) {
   890     return NULL;
   891   }
   892   return typeArrayOop(annos->obj_at(idnum));
   893 }
   895 // for adding methods
   896 // UNSET_IDNUM return means no more ids available
   897 inline u2 instanceKlass::next_method_idnum() {
   898   if (_idnum_allocated_count == constMethodOopDesc::MAX_IDNUM) {
   899     return constMethodOopDesc::UNSET_IDNUM; // no more ids available
   900   } else {
   901     return _idnum_allocated_count++;
   902   }
   903 }
   906 /* JNIid class for jfieldIDs only */
   907 class JNIid: public CHeapObj {
   908   friend class VMStructs;
   909  private:
   910   klassOop           _holder;
   911   JNIid*             _next;
   912   int                _offset;
   913 #ifdef ASSERT
   914   bool               _is_static_field_id;
   915 #endif
   917  public:
   918   // Accessors
   919   klassOop holder() const         { return _holder; }
   920   int offset() const              { return _offset; }
   921   JNIid* next()                   { return _next; }
   922   // Constructor
   923   JNIid(klassOop holder, int offset, JNIid* next);
   924   // Identifier lookup
   925   JNIid* find(int offset);
   927   bool find_local_field(fieldDescriptor* fd) {
   928     return instanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
   929   }
   931   // Garbage collection support
   932   oop* holder_addr() { return (oop*)&_holder; }
   933   void oops_do(OopClosure* f);
   934   static void deallocate(JNIid* id);
   935   // Debugging
   936 #ifdef ASSERT
   937   bool is_static_field_id() const { return _is_static_field_id; }
   938   void set_is_static_field_id()   { _is_static_field_id = true; }
   939 #endif
   940   void verify(klassOop holder);
   941 };
   944 // If breakpoints are more numerous than just JVMTI breakpoints,
   945 // consider compressing this data structure.
   946 // It is currently a simple linked list defined in methodOop.hpp.
   948 class BreakpointInfo;
   951 // A collection point for interesting information about the previous
   952 // version(s) of an instanceKlass. This class uses weak references to
   953 // the information so that the information may be collected as needed
   954 // by the system. If the information is shared, then a regular
   955 // reference must be used because a weak reference would be seen as
   956 // collectible. A GrowableArray of PreviousVersionNodes is attached
   957 // to the instanceKlass as needed. See PreviousVersionWalker below.
   958 class PreviousVersionNode : public CHeapObj {
   959  private:
   960   // A shared ConstantPool is never collected so we'll always have
   961   // a reference to it so we can update items in the cache. We'll
   962   // have a weak reference to a non-shared ConstantPool until all
   963   // of the methods (EMCP or obsolete) have been collected; the
   964   // non-shared ConstantPool becomes collectible at that point.
   965   jobject _prev_constant_pool;  // regular or weak reference
   966   bool    _prev_cp_is_weak;     // true if not a shared ConstantPool
   968   // If the previous version of the instanceKlass doesn't have any
   969   // EMCP methods, then _prev_EMCP_methods will be NULL. If all the
   970   // EMCP methods have been collected, then _prev_EMCP_methods can
   971   // have a length of zero.
   972   GrowableArray<jweak>* _prev_EMCP_methods;
   974 public:
   975   PreviousVersionNode(jobject prev_constant_pool, bool prev_cp_is_weak,
   976     GrowableArray<jweak>* prev_EMCP_methods);
   977   ~PreviousVersionNode();
   978   jobject prev_constant_pool() const {
   979     return _prev_constant_pool;
   980   }
   981   GrowableArray<jweak>* prev_EMCP_methods() const {
   982     return _prev_EMCP_methods;
   983   }
   984 };
   987 // A Handle-ized version of PreviousVersionNode.
   988 class PreviousVersionInfo : public ResourceObj {
   989  private:
   990   constantPoolHandle   _prev_constant_pool_handle;
   991   // If the previous version of the instanceKlass doesn't have any
   992   // EMCP methods, then _prev_EMCP_methods will be NULL. Since the
   993   // methods cannot be collected while we hold a handle,
   994   // _prev_EMCP_methods should never have a length of zero.
   995   GrowableArray<methodHandle>* _prev_EMCP_method_handles;
   997 public:
   998   PreviousVersionInfo(PreviousVersionNode *pv_node);
   999   ~PreviousVersionInfo();
  1000   constantPoolHandle prev_constant_pool_handle() const {
  1001     return _prev_constant_pool_handle;
  1003   GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
  1004     return _prev_EMCP_method_handles;
  1006 };
  1009 // Helper object for walking previous versions. This helper cleans up
  1010 // the Handles that it allocates when the helper object is destroyed.
  1011 // The PreviousVersionInfo object returned by next_previous_version()
  1012 // is only valid until a subsequent call to next_previous_version() or
  1013 // the helper object is destroyed.
  1014 class PreviousVersionWalker : public StackObj {
  1015  private:
  1016   GrowableArray<PreviousVersionNode *>* _previous_versions;
  1017   int                                   _current_index;
  1018   // Fields for cleaning up when we are done walking the previous versions:
  1019   // A HandleMark for the PreviousVersionInfo handles:
  1020   HandleMark                            _hm;
  1022   // It would be nice to have a ResourceMark field in this helper also,
  1023   // but the ResourceMark code says to be careful to delete handles held
  1024   // in GrowableArrays _before_ deleting the GrowableArray. Since we
  1025   // can't guarantee the order in which the fields are destroyed, we
  1026   // have to let the creator of the PreviousVersionWalker object do
  1027   // the right thing. Also, adding a ResourceMark here causes an
  1028   // include loop.
  1030   // A pointer to the current info object so we can handle the deletes.
  1031   PreviousVersionInfo *                 _current_p;
  1033  public:
  1034   PreviousVersionWalker(instanceKlass *ik);
  1035   ~PreviousVersionWalker();
  1037   // Return the interesting information for the next previous version
  1038   // of the klass. Returns NULL if there are no more previous versions.
  1039   PreviousVersionInfo* next_previous_version();
  1040 };
  1043 //
  1044 // nmethodBucket is used to record dependent nmethods for
  1045 // deoptimization.  nmethod dependencies are actually <klass, method>
  1046 // pairs but we really only care about the klass part for purposes of
  1047 // finding nmethods which might need to be deoptimized.  Instead of
  1048 // recording the method, a count of how many times a particular nmethod
  1049 // was recorded is kept.  This ensures that any recording errors are
  1050 // noticed since an nmethod should be removed as many times are it's
  1051 // added.
  1052 //
  1053 class nmethodBucket: public CHeapObj {
  1054   friend class VMStructs;
  1055  private:
  1056   nmethod*       _nmethod;
  1057   int            _count;
  1058   nmethodBucket* _next;
  1060  public:
  1061   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
  1062     _nmethod = nmethod;
  1063     _next = next;
  1064     _count = 1;
  1066   int count()                             { return _count; }
  1067   int increment()                         { _count += 1; return _count; }
  1068   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
  1069   nmethodBucket* next()                   { return _next; }
  1070   void set_next(nmethodBucket* b)         { _next = b; }
  1071   nmethod* get_nmethod()                  { return _nmethod; }
  1072 };
  1074 // An iterator that's used to access the inner classes indices in the
  1075 // instanceKlass::_inner_classes array.
  1076 class InnerClassesIterator : public StackObj {
  1077  private:
  1078   typeArrayHandle _inner_classes;
  1079   int _length;
  1080   int _idx;
  1081  public:
  1083   InnerClassesIterator(instanceKlassHandle k) {
  1084     _inner_classes = k->inner_classes();
  1085     if (k->inner_classes() != NULL) {
  1086       _length = _inner_classes->length();
  1087       // The inner class array's length should be the multiple of
  1088       // inner_class_next_offset if it only contains the InnerClasses
  1089       // attribute data, or it should be
  1090       // n*inner_class_next_offset+enclosing_method_attribute_size
  1091       // if it also contains the EnclosingMethod data.
  1092       assert((_length % instanceKlass::inner_class_next_offset == 0 ||
  1093               _length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size),
  1094              "just checking");
  1095       // Remove the enclosing_method portion if exists.
  1096       if (_length % instanceKlass::inner_class_next_offset == instanceKlass::enclosing_method_attribute_size) {
  1097         _length -= instanceKlass::enclosing_method_attribute_size;
  1099     } else {
  1100       _length = 0;
  1102     _idx = 0;
  1105   int length() const {
  1106     return _length;
  1109   void next() {
  1110     _idx += instanceKlass::inner_class_next_offset;
  1113   bool done() const {
  1114     return (_idx >= _length);
  1117   u2 inner_class_info_index() const {
  1118     return _inner_classes->ushort_at(
  1119                _idx + instanceKlass::inner_class_inner_class_info_offset);
  1122   void set_inner_class_info_index(u2 index) {
  1123     _inner_classes->ushort_at_put(
  1124                _idx + instanceKlass::inner_class_inner_class_info_offset, index);
  1127   u2 outer_class_info_index() const {
  1128     return _inner_classes->ushort_at(
  1129                _idx + instanceKlass::inner_class_outer_class_info_offset);
  1132   void set_outer_class_info_index(u2 index) {
  1133     _inner_classes->ushort_at_put(
  1134                _idx + instanceKlass::inner_class_outer_class_info_offset, index);
  1137   u2 inner_name_index() const {
  1138     return _inner_classes->ushort_at(
  1139                _idx + instanceKlass::inner_class_inner_name_offset);
  1142   void set_inner_name_index(u2 index) {
  1143     _inner_classes->ushort_at_put(
  1144                _idx + instanceKlass::inner_class_inner_name_offset, index);
  1147   u2 inner_access_flags() const {
  1148     return _inner_classes->ushort_at(
  1149                _idx + instanceKlass::inner_class_access_flags_offset);
  1151 };
  1153 #endif // SHARE_VM_OOPS_INSTANCEKLASS_HPP

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