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src/share/vm/oops/klassVtable.hpp

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  25 #ifndef SHARE_VM_OOPS_KLASSVTABLE_HPP
  26 #define SHARE_VM_OOPS_KLASSVTABLE_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "oops/oopsHierarchy.hpp"
  30 #include "runtime/handles.hpp"
  31 #include "utilities/growableArray.hpp"
  32 
  33 // A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
  34 // and ArrayKlass.  klassVtable objects are used just as convenient transient accessors to the vtable,
  35 // not to actually hold the vtable data.
  36 // Note: the klassVtable should not be accessed before the class has been verified
  37 // (until that point, the vtable is uninitialized).
  38 
  39 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore
  40 // not preserved across GCs.
  41 
  42 class vtableEntry;
  43 
  44 class klassVtable : public ResourceObj {
  45   KlassHandle  _klass;            // my klass
  46   int          _tableOffset;      // offset of start of vtable data within klass
  47   int          _length;           // length of vtable (number of entries)
  48 #ifndef PRODUCT
  49   int          _verify_count;     // to make verify faster
  50 #endif
  51 
  52   // Ordering important, so greater_than (>) can be used as an merge operator.
  53   enum AccessType {
  54     acc_private         = 0,
  55     acc_package_private = 1,
  56     acc_publicprotected = 2
  57   };
  58 
  59  public:
  60   klassVtable(KlassHandle h_klass, void* base, int length) : _klass(h_klass) {
  61     _tableOffset = (address)base - (address)h_klass(); _length = length;
  62   }
  63 
  64   // accessors
  65   vtableEntry* table() const      { return (vtableEntry*)(address(_klass()) + _tableOffset); }
  66   KlassHandle klass() const       { return _klass;  }
  67   int length() const              { return _length; }
  68   inline Method* method_at(int i) const;
  69   inline Method* unchecked_method_at(int i) const;
  70   inline Method** adr_method_at(int i) const;
  71 
  72   // searching; all methods return -1 if not found
  73   int index_of(Method* m) const                         { return index_of(m, _length); }
  74   int index_of_miranda(Symbol* name, Symbol* signature);
  75 
  76   void initialize_vtable(bool checkconstraints, TRAPS);   // initialize vtable of a new klass
  77 
  78   // CDS/RedefineClasses support - clear vtables so they can be reinitialized
  79   // at dump time.  Clearing gives us an easy way to tell if the vtable has
  80   // already been reinitialized at dump time (see dump.cpp).  Vtables can
  81   // be initialized at run time by RedefineClasses so dumping the right order
  82   // is necessary.
  83   void clear_vtable();
  84   bool is_initialized();
  85 
  86   // computes vtable length (in words) and the number of miranda methods


 108   bool check_no_old_or_obsolete_entries();
 109   void dump_vtable();
 110 #endif // INCLUDE_JVMTI
 111 
 112   // Debugging code
 113   void print()                                              PRODUCT_RETURN;
 114   void verify(outputStream* st, bool force = false);
 115   static void print_statistics()                            PRODUCT_RETURN;
 116 
 117  protected:
 118   friend class vtableEntry;
 119 
 120  public:
 121   // Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
 122   // Overriding is determined as we create the vtable, so we use the class file version
 123   // of the class whose vtable we are calculating.
 124   enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
 125 
 126  private:
 127   void copy_vtable_to(vtableEntry* start);
 128   int  initialize_from_super(KlassHandle super);
 129   int  index_of(Method* m, int len) const; // same as index_of, but search only up to len
 130   void put_method_at(Method* m, int index);
 131   static bool needs_new_vtable_entry(methodHandle m,
 132                                      const Klass* super,
 133                                      Handle classloader,
 134                                      Symbol* classname,
 135                                      AccessFlags access_flags,
 136                                      u2 major_version,
 137                                      TRAPS);
 138 
 139   bool update_inherited_vtable(InstanceKlass* klass, methodHandle target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
 140  InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, methodHandle target_method, int vtable_index,
 141                                          Handle target_loader, Symbol* target_classname, Thread* THREAD);
 142 
 143   // support for miranda methods
 144   bool is_miranda_entry_at(int i);
 145   int fill_in_mirandas(int initialized);
 146   static bool is_miranda(Method* m, Array<Method*>* class_methods,
 147                          Array<Method*>* default_methods, const Klass* super);
 148   static void add_new_mirandas_to_lists(


 273 //
 274 // Format of an itable
 275 //
 276 //    ---- offset table ---
 277 //    Klass* of interface 1             \
 278 //    offset to vtable from start of oop  / offset table entry
 279 //    ...
 280 //    Klass* of interface n             \
 281 //    offset to vtable from start of oop  / offset table entry
 282 //    --- vtable for interface 1 ---
 283 //    Method*                             \
 284 //    compiler entry point                / method table entry
 285 //    ...
 286 //    Method*                             \
 287 //    compiler entry point                / method table entry
 288 //    -- vtable for interface 2 ---
 289 //    ...
 290 //
 291 class klassItable : public ResourceObj {
 292  private:
 293   instanceKlassHandle  _klass;             // my klass
 294   int                  _table_offset;      // offset of start of itable data within klass (in words)
 295   int                  _size_offset_table; // size of offset table (in itableOffset entries)
 296   int                  _size_method_table; // size of methodtable (in itableMethodEntry entries)
 297 
 298   void initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS);
 299  public:
 300   klassItable(instanceKlassHandle klass);
 301 
 302   itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");
 303                                            return &((itableOffsetEntry*)vtable_start())[i]; }
 304 
 305   itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");
 306                                            return &((itableMethodEntry*)method_start())[i]; }
 307 
 308   int size_offset_table()                { return _size_offset_table; }
 309 
 310   // Initialization
 311   void initialize_itable(bool checkconstraints, TRAPS);
 312 
 313   // Updates
 314   void initialize_with_method(Method* m);
 315 
 316 #if INCLUDE_JVMTI
 317   // RedefineClasses() API support:
 318   // if any entry of this itable points to any of old_methods,
 319   // replace it with the corresponding new_method.
 320   // trace_name_printed is set to true if the current call has
 321   // printed the klass name so that other routines in the adjust_*
 322   // group don't print the klass name.
 323   void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);
 324   bool check_no_old_or_obsolete_entries();
 325   void dump_itable();
 326 #endif // INCLUDE_JVMTI
 327 
 328   // Setup of itable
 329   static int assign_itable_indices_for_interface(Klass* klass);
 330   static int method_count_for_interface(Klass* klass);
 331   static int compute_itable_size(Array<Klass*>* transitive_interfaces);
 332   static void setup_itable_offset_table(instanceKlassHandle klass);
 333 
 334   // Resolving of method to index
 335   static Method* method_for_itable_index(Klass* klass, int itable_index);
 336 
 337   // Debugging/Statistics
 338   static void print_statistics() PRODUCT_RETURN;
 339  private:
 340   intptr_t* vtable_start() const { return ((intptr_t*)_klass()) + _table_offset; }
 341   intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
 342 
 343   // Helper methods
 344   static int  calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
 345 
 346   // Statistics
 347   NOT_PRODUCT(static int  _total_classes;)   // Total no. of classes with itables
 348   NOT_PRODUCT(static long _total_size;)      // Total no. of bytes used for itables
 349 
 350   static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
 351 };
 352 
 353 #endif // SHARE_VM_OOPS_KLASSVTABLE_HPP


  25 #ifndef SHARE_VM_OOPS_KLASSVTABLE_HPP
  26 #define SHARE_VM_OOPS_KLASSVTABLE_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "oops/oopsHierarchy.hpp"
  30 #include "runtime/handles.hpp"
  31 #include "utilities/growableArray.hpp"
  32 
  33 // A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
  34 // and ArrayKlass.  klassVtable objects are used just as convenient transient accessors to the vtable,
  35 // not to actually hold the vtable data.
  36 // Note: the klassVtable should not be accessed before the class has been verified
  37 // (until that point, the vtable is uninitialized).
  38 
  39 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore
  40 // not preserved across GCs.
  41 
  42 class vtableEntry;
  43 
  44 class klassVtable : public ResourceObj {
  45   Klass*       _klass;            // my klass
  46   int          _tableOffset;      // offset of start of vtable data within klass
  47   int          _length;           // length of vtable (number of entries)
  48 #ifndef PRODUCT
  49   int          _verify_count;     // to make verify faster
  50 #endif
  51 
  52   // Ordering important, so greater_than (>) can be used as an merge operator.
  53   enum AccessType {
  54     acc_private         = 0,
  55     acc_package_private = 1,
  56     acc_publicprotected = 2
  57   };
  58 
  59  public:
  60   klassVtable(Klass* klass, void* base, int length) : _klass(klass) {
  61     _tableOffset = (address)base - (address)klass; _length = length;
  62   }
  63 
  64   // accessors
  65   vtableEntry* table() const      { return (vtableEntry*)(address(_klass) + _tableOffset); }
  66   Klass* klass() const            { return _klass;  }
  67   int length() const              { return _length; }
  68   inline Method* method_at(int i) const;
  69   inline Method* unchecked_method_at(int i) const;
  70   inline Method** adr_method_at(int i) const;
  71 
  72   // searching; all methods return -1 if not found
  73   int index_of(Method* m) const                         { return index_of(m, _length); }
  74   int index_of_miranda(Symbol* name, Symbol* signature);
  75 
  76   void initialize_vtable(bool checkconstraints, TRAPS);   // initialize vtable of a new klass
  77 
  78   // CDS/RedefineClasses support - clear vtables so they can be reinitialized
  79   // at dump time.  Clearing gives us an easy way to tell if the vtable has
  80   // already been reinitialized at dump time (see dump.cpp).  Vtables can
  81   // be initialized at run time by RedefineClasses so dumping the right order
  82   // is necessary.
  83   void clear_vtable();
  84   bool is_initialized();
  85 
  86   // computes vtable length (in words) and the number of miranda methods


 108   bool check_no_old_or_obsolete_entries();
 109   void dump_vtable();
 110 #endif // INCLUDE_JVMTI
 111 
 112   // Debugging code
 113   void print()                                              PRODUCT_RETURN;
 114   void verify(outputStream* st, bool force = false);
 115   static void print_statistics()                            PRODUCT_RETURN;
 116 
 117  protected:
 118   friend class vtableEntry;
 119 
 120  public:
 121   // Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
 122   // Overriding is determined as we create the vtable, so we use the class file version
 123   // of the class whose vtable we are calculating.
 124   enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
 125 
 126  private:
 127   void copy_vtable_to(vtableEntry* start);
 128   int  initialize_from_super(Klass* super);
 129   int  index_of(Method* m, int len) const; // same as index_of, but search only up to len
 130   void put_method_at(Method* m, int index);
 131   static bool needs_new_vtable_entry(methodHandle m,
 132                                      const Klass* super,
 133                                      Handle classloader,
 134                                      Symbol* classname,
 135                                      AccessFlags access_flags,
 136                                      u2 major_version,
 137                                      TRAPS);
 138 
 139   bool update_inherited_vtable(InstanceKlass* klass, methodHandle target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
 140  InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, methodHandle target_method, int vtable_index,
 141                                          Handle target_loader, Symbol* target_classname, Thread* THREAD);
 142 
 143   // support for miranda methods
 144   bool is_miranda_entry_at(int i);
 145   int fill_in_mirandas(int initialized);
 146   static bool is_miranda(Method* m, Array<Method*>* class_methods,
 147                          Array<Method*>* default_methods, const Klass* super);
 148   static void add_new_mirandas_to_lists(


 273 //
 274 // Format of an itable
 275 //
 276 //    ---- offset table ---
 277 //    Klass* of interface 1             \
 278 //    offset to vtable from start of oop  / offset table entry
 279 //    ...
 280 //    Klass* of interface n             \
 281 //    offset to vtable from start of oop  / offset table entry
 282 //    --- vtable for interface 1 ---
 283 //    Method*                             \
 284 //    compiler entry point                / method table entry
 285 //    ...
 286 //    Method*                             \
 287 //    compiler entry point                / method table entry
 288 //    -- vtable for interface 2 ---
 289 //    ...
 290 //
 291 class klassItable : public ResourceObj {
 292  private:
 293   InstanceKlass*       _klass;             // my klass
 294   int                  _table_offset;      // offset of start of itable data within klass (in words)
 295   int                  _size_offset_table; // size of offset table (in itableOffset entries)
 296   int                  _size_method_table; // size of methodtable (in itableMethodEntry entries)
 297 
 298   void initialize_itable_for_interface(int method_table_offset, Klass* interf_h, bool checkconstraints, TRAPS);
 299  public:
 300   klassItable(InstanceKlass* klass);
 301 
 302   itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");
 303                                            return &((itableOffsetEntry*)vtable_start())[i]; }
 304 
 305   itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");
 306                                            return &((itableMethodEntry*)method_start())[i]; }
 307 
 308   int size_offset_table()                { return _size_offset_table; }
 309 
 310   // Initialization
 311   void initialize_itable(bool checkconstraints, TRAPS);
 312 
 313   // Updates
 314   void initialize_with_method(Method* m);
 315 
 316 #if INCLUDE_JVMTI
 317   // RedefineClasses() API support:
 318   // if any entry of this itable points to any of old_methods,
 319   // replace it with the corresponding new_method.
 320   // trace_name_printed is set to true if the current call has
 321   // printed the klass name so that other routines in the adjust_*
 322   // group don't print the klass name.
 323   void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);
 324   bool check_no_old_or_obsolete_entries();
 325   void dump_itable();
 326 #endif // INCLUDE_JVMTI
 327 
 328   // Setup of itable
 329   static int assign_itable_indices_for_interface(Klass* klass);
 330   static int method_count_for_interface(Klass* klass);
 331   static int compute_itable_size(Array<Klass*>* transitive_interfaces);
 332   static void setup_itable_offset_table(InstanceKlass* klass);
 333 
 334   // Resolving of method to index
 335   static Method* method_for_itable_index(Klass* klass, int itable_index);
 336 
 337   // Debugging/Statistics
 338   static void print_statistics() PRODUCT_RETURN;
 339  private:
 340   intptr_t* vtable_start() const { return ((intptr_t*)_klass) + _table_offset; }
 341   intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
 342 
 343   // Helper methods
 344   static int  calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
 345 
 346   // Statistics
 347   NOT_PRODUCT(static int  _total_classes;)   // Total no. of classes with itables
 348   NOT_PRODUCT(static long _total_size;)      // Total no. of bytes used for itables
 349 
 350   static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
 351 };
 352 
 353 #endif // SHARE_VM_OOPS_KLASSVTABLE_HPP
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