1 #ifdef USE_PRAGMA_IDENT_HDR
2 #pragma ident "@(#)klassVtable.hpp 1.62 07/07/19 12:19:09 JVM"
3 #endif
4 /*
5 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 // A klassVtable abstracts the variable-length vtable that is embedded in instanceKlass
29 // and arrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable,
30 // not to actually hold the vtable data.
31 // Note: the klassVtable should not be accessed before the class has been verified
32 // (until that point, the vtable is uninitialized).
33
34 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore
35 // not preserved across GCs.
36
37 class vtableEntry;
38
39 class klassVtable : public ResourceObj {
40 KlassHandle _klass; // my klass
41 int _tableOffset; // offset of start of vtable data within klass
42 int _length; // length of vtable (number of entries)
43 #ifndef PRODUCT
44 int _verify_count; // to make verify faster
45 #endif
46
47 // Ordering important, so greater_than (>) can be used as an merge operator.
48 enum AccessType {
49 acc_private = 0,
50 acc_package_private = 1,
51 acc_publicprotected = 2
52 };
53
54 public:
55 klassVtable(KlassHandle h_klass, void* base, int length) : _klass(h_klass) {
56 _tableOffset = (address)base - (address)h_klass(); _length = length;
57 }
58
59 // accessors
60 vtableEntry* table() const { return (vtableEntry*)(address(_klass()) + _tableOffset); }
61 KlassHandle klass() const { return _klass; }
62 int length() const { return _length; }
63 inline methodOop method_at(int i) const;
64 inline methodOop unchecked_method_at(int i) const;
65 inline oop* adr_method_at(int i) const;
66
67 // searching; all methods return -1 if not found
68 int index_of(methodOop m) const { return index_of(m, _length); }
69 int index_of_miranda(symbolOop name, symbolOop signature);
70
71 void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass
72
73 // conputes vtable length (in words) and the number of miranda methods
74 static void compute_vtable_size_and_num_mirandas(int &vtable_length, int &num_miranda_methods,
75 klassOop super, objArrayOop methods,
76 AccessFlags class_flags, oop classloader,
77 symbolOop classname, objArrayOop local_interfaces);
78
79 // RedefineClasses() API support:
80 // If any entry of this vtable points to any of old_methods,
81 // replace it with the corresponding new_method.
82 // trace_name_printed is set to true if the current call has
83 // printed the klass name so that other routines in the adjust_*
84 // group don't print the klass name.
85 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
86 int methods_length, bool * trace_name_printed);
87
88 // Garbage collection
89 void oop_follow_contents();
90 void oop_adjust_pointers();
91
92 #ifndef SERIALGC
93 // Parallel Old
94 void oop_follow_contents(ParCompactionManager* cm);
95 void oop_update_pointers(ParCompactionManager* cm);
96 void oop_update_pointers(ParCompactionManager* cm,
97 HeapWord* beg_addr, HeapWord* end_addr);
98 #endif // SERIALGC
99
100 // Iterators
101 void oop_oop_iterate(OopClosure* blk);
102 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr);
103
104 // Debugging code
105 void print() PRODUCT_RETURN;
106 void verify(outputStream* st, bool force = false);
107 static void print_statistics() PRODUCT_RETURN;
108
109 #ifndef PRODUCT
110 bool check_no_old_entries();
111 void dump_vtable();
112 #endif
113
114 protected:
115 friend class vtableEntry;
116 private:
117 void copy_vtable_to(vtableEntry* start);
118 int initialize_from_super(KlassHandle super);
119 int index_of(methodOop m, int len) const; // same as index_of, but search only up to len
120 void put_method_at(methodOop m, int index);
121 static bool needs_new_vtable_entry(methodOop m, klassOop super, oop classloader, symbolOop classname, AccessFlags access_flags);
122 AccessType vtable_accessibility_at(int i);
123
124 bool update_super_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len, bool checkconstraints, TRAPS);
125
126 // support for miranda methods
127 bool is_miranda_entry_at(int i);
128 void fill_in_mirandas(int& initialized);
129 static bool is_miranda(methodOop m, objArrayOop class_methods, klassOop super);
130 static void add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas, objArrayOop current_interface_methods, objArrayOop class_methods, klassOop super);
131 static void get_mirandas(GrowableArray<methodOop>* mirandas, klassOop super, objArrayOop class_methods, objArrayOop local_interfaces);
132 static int get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces);
133
134
135 void verify_against(outputStream* st, klassVtable* vt, int index);
136 inline instanceKlass* ik() const;
137 };
138
139
140 // private helper class for klassVtable
141 // description of entry points:
142 // destination is interpreted:
143 // from_compiled_code_entry_point -> c2iadapter
144 // from_interpreter_entry_point -> interpreter entry point
145 // destination is compiled:
146 // from_compiled_code_entry_point -> nmethod entry point
147 // from_interpreter_entry_point -> i2cadapter
148 class vtableEntry VALUE_OBJ_CLASS_SPEC {
149 public:
150 // size in words
151 static int size() {
152 return sizeof(vtableEntry) / sizeof(HeapWord);
153 }
154 static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); }
155 methodOop method() const { return _method; }
156
157 private:
158 methodOop _method;
159 void set(methodOop method) { assert(method != NULL, "use clear"); _method = method; }
160 void clear() { _method = NULL; }
161 void print() PRODUCT_RETURN;
162 void verify(klassVtable* vt, outputStream* st);
163
164 friend class klassVtable;
165 };
166
167
168 inline methodOop klassVtable::method_at(int i) const {
169 assert(i >= 0 && i < _length, "index out of bounds");
170 assert(table()[i].method() != NULL, "should not be null");
171 assert(oop(table()[i].method())->is_method(), "should be method");
172 return table()[i].method();
173 }
174
175 inline methodOop klassVtable::unchecked_method_at(int i) const {
176 assert(i >= 0 && i < _length, "index out of bounds");
177 return table()[i].method();
178 }
179
180 inline oop* klassVtable::adr_method_at(int i) const {
181 // Allow one past the last entry to be referenced; useful for loop bounds.
182 assert(i >= 0 && i <= _length, "index out of bounds");
183 return (oop*)(address(table() + i) + vtableEntry::method_offset_in_bytes());
184 }
185
186 // --------------------------------------------------------------------------------
187 class klassItable;
188 class itableMethodEntry;
189
190 class itableOffsetEntry VALUE_OBJ_CLASS_SPEC {
191 private:
192 klassOop _interface;
193 int _offset;
194 public:
195 klassOop interface_klass() const { return _interface; }
196 int offset() const { return _offset; }
197
198 static itableMethodEntry* method_entry(klassOop k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }
199 itableMethodEntry* first_method_entry(klassOop k) { return method_entry(k, _offset); }
200
201 void initialize(klassOop interf, int offset) { _interface = interf; _offset = offset; }
202
203 // Static size and offset accessors
204 static int size() { return sizeof(itableOffsetEntry) / HeapWordSize; } // size in words
205 static int interface_offset_in_bytes() { return offset_of(itableOffsetEntry, _interface); }
206 static int offset_offset_in_bytes() { return offset_of(itableOffsetEntry, _offset); }
207
208 friend class klassItable;
209 };
210
211
212 class itableMethodEntry VALUE_OBJ_CLASS_SPEC {
213 private:
214 methodOop _method;
215
216 public:
217 methodOop method() const { return _method; }
218
219 void clear() { _method = NULL; }
220
221 void initialize(methodOop method);
222
223 // Static size and offset accessors
224 static int size() { return sizeof(itableMethodEntry) / HeapWordSize; } // size in words
225 static int method_offset_in_bytes() { return offset_of(itableMethodEntry, _method); }
226
227 friend class klassItable;
228 };
229
230 //
231 // Format of an itable
232 //
233 // ---- offset table ---
234 // klassOop of interface 1 \
235 // offset to vtable from start of oop / offset table entry
236 // ...
237 // klassOop of interface n \
238 // offset to vtable from start of oop / offset table entry
239 // --- vtable for interface 1 ---
240 // methodOop \
241 // compiler entry point / method table entry
242 // ...
243 // methodOop \
244 // compiler entry point / method table entry
245 // -- vtable for interface 2 ---
246 // ...
247 //
248 class klassItable : public ResourceObj {
249 private:
250 instanceKlassHandle _klass; // my klass
251 int _table_offset; // offset of start of itable data within klass (in words)
252 int _size_offset_table; // size of offset table (in itableOffset entries)
253 int _size_method_table; // size of methodtable (in itableMethodEntry entries)
254
255 void initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS);
256 public:
257 klassItable(instanceKlassHandle klass);
258
259 itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");
260 return &((itableOffsetEntry*)vtable_start())[i]; }
261
262 itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");
263 return &((itableMethodEntry*)method_start())[i]; }
264
265 int size_offset_table() { return _size_offset_table; }
266
267 // Initialization
268 void initialize_itable(bool checkconstraints, TRAPS);
269
270 // Updates
271 void initialize_with_method(methodOop m);
272
273 // RedefineClasses() API support:
274 // if any entry of this itable points to any of old_methods,
275 // replace it with the corresponding new_method.
276 // trace_name_printed is set to true if the current call has
277 // printed the klass name so that other routines in the adjust_*
278 // group don't print the klass name.
279 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
280 int methods_length, bool * trace_name_printed);
281
282 // Garbage collection
283 void oop_follow_contents();
284 void oop_adjust_pointers();
285
286 #ifndef SERIALGC
287 // Parallel Old
288 void oop_follow_contents(ParCompactionManager* cm);
289 void oop_update_pointers(ParCompactionManager* cm);
290 void oop_update_pointers(ParCompactionManager* cm,
291 HeapWord* beg_addr, HeapWord* end_addr);
292 #endif // SERIALGC
293
294 // Iterators
295 void oop_oop_iterate(OopClosure* blk);
296 void oop_oop_iterate_m(OopClosure* blk, MemRegion mr);
297
298 // Setup of itable
299 static int compute_itable_size(objArrayHandle transitive_interfaces);
300 static void setup_itable_offset_table(instanceKlassHandle klass);
301
302 // Resolving of method to index
303 static int compute_itable_index(methodOop m);
304
305 // Debugging/Statistics
306 static void print_statistics() PRODUCT_RETURN;
307 private:
308 intptr_t* vtable_start() const { return ((intptr_t*)_klass()) + _table_offset; }
309 intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
310
311 // Helper methods
312 static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
313
314 // Statistics
315 NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables
316 NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables
317
318 static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
319 };