31
32 // A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
33 // and ArrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable,
34 // not to actually hold the vtable data.
35 // Note: the klassVtable should not be accessed before the class has been verified
36 // (until that point, the vtable is uninitialized).
37
38 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore
39 // not preserved across GCs.
40
41 class vtableEntry;
42
43 class klassVtable {
44 Klass* _klass; // my klass
45 int _tableOffset; // offset of start of vtable data within klass
46 int _length; // length of vtable (number of entries)
47 #ifndef PRODUCT
48 int _verify_count; // to make verify faster
49 #endif
50
51 // Ordering important, so greater_than (>) can be used as an merge operator.
52 enum AccessType {
53 acc_private = 0,
54 acc_package_private = 1,
55 acc_publicprotected = 2
56 };
57
58 public:
59 klassVtable(Klass* klass, void* base, int length) : _klass(klass) {
60 _tableOffset = (address)base - (address)klass; _length = length;
61 }
62
63 // accessors
64 vtableEntry* table() const { return (vtableEntry*)(address(_klass) + _tableOffset); }
65 Klass* klass() const { return _klass; }
66 int length() const { return _length; }
67 inline Method* method_at(int i) const;
68 inline Method* unchecked_method_at(int i) const;
69 inline Method** adr_method_at(int i) const;
70
71 // searching; all methods return -1 if not found
72 int index_of(Method* m) const { return index_of(m, _length); }
73 int index_of_miranda(Symbol* name, Symbol* signature);
74
75 void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass
76
77 // CDS/RedefineClasses support - clear vtables so they can be reinitialized
78 // at dump time. Clearing gives us an easy way to tell if the vtable has
79 // already been reinitialized at dump time (see dump.cpp). Vtables can
80 // be initialized at run time by RedefineClasses so dumping the right order
81 // is necessary.
82 void clear_vtable();
83 bool is_initialized();
84
85 // computes vtable length (in words) and the number of miranda methods
86 static void compute_vtable_size_and_num_mirandas(int* vtable_length,
87 int* num_new_mirandas,
88 GrowableArray<Method*>* all_mirandas,
89 const Klass* super,
90 Array<Method*>* methods,
91 AccessFlags class_flags,
92 u2 major_version,
93 Handle classloader,
94 Symbol* classname,
95 Array<InstanceKlass*>* local_interfaces,
96 TRAPS);
97
98 #if INCLUDE_JVMTI
99 // RedefineClasses() API support:
100 // If any entry of this vtable points to any of old_methods,
101 // replace it with the corresponding new_method.
102 // trace_name_printed is set to true if the current call has
103 // printed the klass name so that other routines in the adjust_*
104 // group don't print the klass name.
108 void dump_vtable();
109 #endif // INCLUDE_JVMTI
110
111 // Debugging code
112 void print() PRODUCT_RETURN;
113 void verify(outputStream* st, bool force = false);
114 static void print_statistics() PRODUCT_RETURN;
115
116 protected:
117 friend class vtableEntry;
118
119 public:
120 // Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
121 // Overriding is determined as we create the vtable, so we use the class file version
122 // of the class whose vtable we are calculating.
123 enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
124
125 private:
126 void copy_vtable_to(vtableEntry* start);
127 int initialize_from_super(Klass* super);
128 int index_of(Method* m, int len) const; // same as index_of, but search only up to len
129 void put_method_at(Method* m, int index);
130 static bool needs_new_vtable_entry(const methodHandle& m,
131 const Klass* super,
132 Handle classloader,
133 Symbol* classname,
134 AccessFlags access_flags,
135 u2 major_version,
136 TRAPS);
137
138 bool update_inherited_vtable(InstanceKlass* klass, const methodHandle& target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
139 InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, const methodHandle& target_method, int vtable_index,
140 Handle target_loader, Symbol* target_classname, Thread* THREAD);
141
142 // support for miranda methods
143 bool is_miranda_entry_at(int i);
144 int fill_in_mirandas(int initialized, TRAPS);
145 static bool is_miranda(Method* m, Array<Method*>* class_methods,
146 Array<Method*>* default_methods, const Klass* super,
147 bool is_interface);
148 static void add_new_mirandas_to_lists(
206 void clear() { _method = NULL; }
207 void print() PRODUCT_RETURN;
208 void verify(klassVtable* vt, outputStream* st);
209
210 friend class klassVtable;
211 };
212
213
214 inline Method* klassVtable::method_at(int i) const {
215 assert(i >= 0 && i < _length, "index out of bounds");
216 assert(table()[i].method() != NULL, "should not be null");
217 assert(((Metadata*)table()[i].method())->is_method(), "should be method");
218 return table()[i].method();
219 }
220
221 inline Method* klassVtable::unchecked_method_at(int i) const {
222 assert(i >= 0 && i < _length, "index out of bounds");
223 return table()[i].method();
224 }
225
226 inline Method** klassVtable::adr_method_at(int i) const {
227 // Allow one past the last entry to be referenced; useful for loop bounds.
228 assert(i >= 0 && i <= _length, "index out of bounds");
229 return (Method**)(address(table() + i) + vtableEntry::method_offset_in_bytes());
230 }
231
232 // --------------------------------------------------------------------------------
233 class klassItable;
234 class itableMethodEntry;
235
236 class itableOffsetEntry {
237 private:
238 InstanceKlass* _interface;
239 int _offset;
240 public:
241 InstanceKlass* interface_klass() const { return _interface; }
242 InstanceKlass**interface_klass_addr() { return &_interface; }
243 int offset() const { return _offset; }
244
245 static itableMethodEntry* method_entry(Klass* k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }
246 itableMethodEntry* first_method_entry(Klass* k) { return method_entry(k, _offset); }
247
248 void initialize(InstanceKlass* interf, int offset) { _interface = interf; _offset = offset; }
249
250 // Static size and offset accessors
251 static int size() { return sizeof(itableOffsetEntry) / wordSize; } // size in words
315 // Initialization
316 void initialize_itable(bool checkconstraints, TRAPS);
317
318 #if INCLUDE_JVMTI
319 // RedefineClasses() API support:
320 // if any entry of this itable points to any of old_methods,
321 // replace it with the corresponding new_method.
322 // trace_name_printed is set to true if the current call has
323 // printed the klass name so that other routines in the adjust_*
324 // group don't print the klass name.
325 void adjust_method_entries(bool* trace_name_printed);
326 bool check_no_old_or_obsolete_entries();
327 void dump_itable();
328 #endif // INCLUDE_JVMTI
329
330 // Setup of itable
331 static int assign_itable_indices_for_interface(InstanceKlass* klass, TRAPS);
332 static int method_count_for_interface(InstanceKlass* klass);
333 static int compute_itable_size(Array<InstanceKlass*>* transitive_interfaces);
334 static void setup_itable_offset_table(InstanceKlass* klass);
335
336 // Resolving of method to index
337 static Method* method_for_itable_index(InstanceKlass* klass, int itable_index);
338
339 // Debugging/Statistics
340 static void print_statistics() PRODUCT_RETURN;
341 private:
342 intptr_t* vtable_start() const { return ((intptr_t*)_klass) + _table_offset; }
343 intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
344
345 // Helper methods
346 static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
347
348 // Statistics
349 NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables
350 NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables
351
352 static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
353 };
354
355 #endif // SHARE_OOPS_KLASSVTABLE_HPP
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31
32 // A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
33 // and ArrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable,
34 // not to actually hold the vtable data.
35 // Note: the klassVtable should not be accessed before the class has been verified
36 // (until that point, the vtable is uninitialized).
37
38 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore
39 // not preserved across GCs.
40
41 class vtableEntry;
42
43 class klassVtable {
44 Klass* _klass; // my klass
45 int _tableOffset; // offset of start of vtable data within klass
46 int _length; // length of vtable (number of entries)
47 #ifndef PRODUCT
48 int _verify_count; // to make verify faster
49 #endif
50
51 public:
52 klassVtable(Klass* klass, void* base, int length) : _klass(klass) {
53 _tableOffset = (address)base - (address)klass; _length = length;
54 }
55
56 // accessors
57 vtableEntry* table() const { return (vtableEntry*)(address(_klass) + _tableOffset); }
58 Klass* klass() const { return _klass; }
59 int length() const { return _length; }
60 inline Method* method_at(int i) const;
61 inline Method* unchecked_method_at(int i) const;
62
63 // searching; all methods return -1 if not found
64 int index_of_miranda(Symbol* name, Symbol* signature);
65
66 void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass
67
68 // computes vtable length (in words) and the number of miranda methods
69 static void compute_vtable_size_and_num_mirandas(int* vtable_length,
70 int* num_new_mirandas,
71 GrowableArray<Method*>* all_mirandas,
72 const Klass* super,
73 Array<Method*>* methods,
74 AccessFlags class_flags,
75 u2 major_version,
76 Handle classloader,
77 Symbol* classname,
78 Array<InstanceKlass*>* local_interfaces,
79 TRAPS);
80
81 #if INCLUDE_JVMTI
82 // RedefineClasses() API support:
83 // If any entry of this vtable points to any of old_methods,
84 // replace it with the corresponding new_method.
85 // trace_name_printed is set to true if the current call has
86 // printed the klass name so that other routines in the adjust_*
87 // group don't print the klass name.
91 void dump_vtable();
92 #endif // INCLUDE_JVMTI
93
94 // Debugging code
95 void print() PRODUCT_RETURN;
96 void verify(outputStream* st, bool force = false);
97 static void print_statistics() PRODUCT_RETURN;
98
99 protected:
100 friend class vtableEntry;
101
102 public:
103 // Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
104 // Overriding is determined as we create the vtable, so we use the class file version
105 // of the class whose vtable we are calculating.
106 enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
107
108 private:
109 void copy_vtable_to(vtableEntry* start);
110 int initialize_from_super(Klass* super);
111 void put_method_at(Method* m, int index);
112 static bool needs_new_vtable_entry(const methodHandle& m,
113 const Klass* super,
114 Handle classloader,
115 Symbol* classname,
116 AccessFlags access_flags,
117 u2 major_version,
118 TRAPS);
119
120 bool update_inherited_vtable(InstanceKlass* klass, const methodHandle& target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
121 InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, const methodHandle& target_method, int vtable_index,
122 Handle target_loader, Symbol* target_classname, Thread* THREAD);
123
124 // support for miranda methods
125 bool is_miranda_entry_at(int i);
126 int fill_in_mirandas(int initialized, TRAPS);
127 static bool is_miranda(Method* m, Array<Method*>* class_methods,
128 Array<Method*>* default_methods, const Klass* super,
129 bool is_interface);
130 static void add_new_mirandas_to_lists(
188 void clear() { _method = NULL; }
189 void print() PRODUCT_RETURN;
190 void verify(klassVtable* vt, outputStream* st);
191
192 friend class klassVtable;
193 };
194
195
196 inline Method* klassVtable::method_at(int i) const {
197 assert(i >= 0 && i < _length, "index out of bounds");
198 assert(table()[i].method() != NULL, "should not be null");
199 assert(((Metadata*)table()[i].method())->is_method(), "should be method");
200 return table()[i].method();
201 }
202
203 inline Method* klassVtable::unchecked_method_at(int i) const {
204 assert(i >= 0 && i < _length, "index out of bounds");
205 return table()[i].method();
206 }
207
208 // --------------------------------------------------------------------------------
209 class klassItable;
210 class itableMethodEntry;
211
212 class itableOffsetEntry {
213 private:
214 InstanceKlass* _interface;
215 int _offset;
216 public:
217 InstanceKlass* interface_klass() const { return _interface; }
218 InstanceKlass**interface_klass_addr() { return &_interface; }
219 int offset() const { return _offset; }
220
221 static itableMethodEntry* method_entry(Klass* k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }
222 itableMethodEntry* first_method_entry(Klass* k) { return method_entry(k, _offset); }
223
224 void initialize(InstanceKlass* interf, int offset) { _interface = interf; _offset = offset; }
225
226 // Static size and offset accessors
227 static int size() { return sizeof(itableOffsetEntry) / wordSize; } // size in words
291 // Initialization
292 void initialize_itable(bool checkconstraints, TRAPS);
293
294 #if INCLUDE_JVMTI
295 // RedefineClasses() API support:
296 // if any entry of this itable points to any of old_methods,
297 // replace it with the corresponding new_method.
298 // trace_name_printed is set to true if the current call has
299 // printed the klass name so that other routines in the adjust_*
300 // group don't print the klass name.
301 void adjust_method_entries(bool* trace_name_printed);
302 bool check_no_old_or_obsolete_entries();
303 void dump_itable();
304 #endif // INCLUDE_JVMTI
305
306 // Setup of itable
307 static int assign_itable_indices_for_interface(InstanceKlass* klass, TRAPS);
308 static int method_count_for_interface(InstanceKlass* klass);
309 static int compute_itable_size(Array<InstanceKlass*>* transitive_interfaces);
310 static void setup_itable_offset_table(InstanceKlass* klass);
311
312 // Debugging/Statistics
313 static void print_statistics() PRODUCT_RETURN;
314 private:
315 intptr_t* vtable_start() const { return ((intptr_t*)_klass) + _table_offset; }
316 intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
317
318 // Helper methods
319 static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
320
321 // Statistics
322 NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables
323 NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables
324
325 static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
326 };
327
328 #endif // SHARE_OOPS_KLASSVTABLE_HPP
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