1 /*
2 * Copyright (c) 2003, 2012, 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 */
24
25 #ifndef SHARE_VM_CLASSFILE_DICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_DICTIONARY_HPP
27
28 #include "classfile/systemDictionary.hpp"
29 #include "oops/instanceKlass.hpp"
30 #include "oops/oop.hpp"
31 #include "utilities/hashtable.hpp"
32
33 class DictionaryEntry;
34 class PSPromotionManager;
35
36 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 // The data structure for the system dictionary (and the shared system
38 // dictionary).
39
40 class Dictionary : public TwoOopHashtable<Klass*, mtClass> {
41 friend class VMStructs;
42 private:
43 // current iteration index.
44 static int _current_class_index;
45 // pointer to the current hash table entry.
46 static DictionaryEntry* _current_class_entry;
47
48 DictionaryEntry* get_entry(int index, unsigned int hash,
49 Symbol* name, ClassLoaderData* loader_data);
50
51 DictionaryEntry* bucket(int i) {
52 return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i);
53 }
54
55 // The following method is not MT-safe and must be done under lock.
56 DictionaryEntry** bucket_addr(int i) {
57 return (DictionaryEntry**)Hashtable<Klass*, mtClass>::bucket_addr(i);
58 }
59
60 void add_entry(int index, DictionaryEntry* new_entry) {
61 Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry);
62 }
63
64 public:
65 Dictionary(int table_size);
66 Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
67
68 DictionaryEntry* new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data);
69
70 DictionaryEntry* new_entry();
71
72 void free_entry(DictionaryEntry* entry);
73
74 void add_klass(Symbol* class_name, ClassLoaderData* loader_data,KlassHandle obj);
75
76 Klass* find_class(int index, unsigned int hash,
77 Symbol* name, ClassLoaderData* loader_data);
78
79 Klass* find_shared_class(int index, unsigned int hash, Symbol* name);
80
81 // Compiler support
82 Klass* try_get_next_class();
83
84 // GC support
85 void oops_do(OopClosure* f);
86 void always_strong_oops_do(OopClosure* blk);
87
88 void always_strong_classes_do(KlassClosure* closure);
89
90 void classes_do(void f(Klass*));
91 void classes_do(void f(Klass*, TRAPS), TRAPS);
92 void classes_do(void f(Klass*, ClassLoaderData*));
93
94 void methods_do(void f(Method*));
95
96
97 // Classes loaded by the bootstrap loader are always strongly reachable.
98 // If we're not doing class unloading, all classes are strongly reachable.
99 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {
100 assert (klass != NULL, "should have non-null klass");
101 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);
102 }
103
104 // Unload (that is, break root links to) all unmarked classes and
105 // loaders. Returns "true" iff something was unloaded.
106 bool do_unloading();
107
108 // Protection domains
109 Klass* find(int index, unsigned int hash, Symbol* name,
110 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
111 bool is_valid_protection_domain(int index, unsigned int hash,
112 Symbol* name, ClassLoaderData* loader_data,
113 Handle protection_domain);
114 void add_protection_domain(int index, unsigned int hash,
115 instanceKlassHandle klass, ClassLoaderData* loader_data,
116 Handle protection_domain, TRAPS);
117
118 // Sharing support
119 void reorder_dictionary();
120
121
122 #ifndef PRODUCT
123 void print();
124 #endif
125 void verify();
126 };
127
128 // The following classes can be in dictionary.cpp, but we need these
129 // to be in header file so that SA's vmStructs can access.
130
131 class ProtectionDomainEntry :public CHeapObj<mtClass> {
132 friend class VMStructs;
133 public:
134 ProtectionDomainEntry* _next;
135 oop _protection_domain;
136
137 ProtectionDomainEntry(oop protection_domain, ProtectionDomainEntry* next) {
138 _protection_domain = protection_domain;
139 _next = next;
140 }
141
142 ProtectionDomainEntry* next() { return _next; }
143 oop protection_domain() { return _protection_domain; }
144 };
145
146 // An entry in the system dictionary, this describes a class as
147 // { Klass*, loader, protection_domain }.
148
149 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
150 friend class VMStructs;
151 private:
152 // Contains the set of approved protection domains that can access
153 // this system dictionary entry.
154 ProtectionDomainEntry* _pd_set;
155 ClassLoaderData* _loader_data;
156
157 public:
158 // Tells whether a protection is in the approved set.
159 bool contains_protection_domain(oop protection_domain) const;
160 // Adds a protection domain to the approved set.
161 void add_protection_domain(oop protection_domain);
162
163 Klass* klass() const { return (Klass*)literal(); }
164 Klass** klass_addr() { return (Klass**)literal_addr(); }
165
166 DictionaryEntry* next() const {
167 return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();
168 }
169
170 DictionaryEntry** next_addr() {
171 return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
172 }
173
174 ClassLoaderData* loader_data() const { return _loader_data; }
175 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
176
177 ProtectionDomainEntry* pd_set() const { return _pd_set; }
178 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
179
180 bool has_protection_domain() { return _pd_set != NULL; }
181
182 // Tells whether the initiating class' protection can access the this _klass
183 bool is_valid_protection_domain(Handle protection_domain) {
184 if (!ProtectionDomainVerification) return true;
185 if (!SystemDictionary::has_checkPackageAccess()) return true;
186
187 return protection_domain() == NULL
188 ? true
189 : contains_protection_domain(protection_domain());
190 }
191
192
193 void protection_domain_set_oops_do(OopClosure* f) {
194 for (ProtectionDomainEntry* current = _pd_set;
195 current != NULL;
196 current = current->_next) {
197 f->do_oop(&(current->_protection_domain));
198 }
199 }
200
201 void verify_protection_domain_set() {
202 for (ProtectionDomainEntry* current = _pd_set;
203 current != NULL;
204 current = current->_next) {
205 current->_protection_domain->verify();
206 }
207 }
208
209 bool equals(Symbol* class_name, ClassLoaderData* loader_data) const {
210 Klass* klass = (Klass*)literal();
211 return (InstanceKlass::cast(klass)->name() == class_name &&
212 _loader_data == loader_data);
213 }
214
215 void print() {
216 int count = 0;
217 for (ProtectionDomainEntry* current = _pd_set;
218 current != NULL;
219 current = current->_next) {
220 count++;
221 }
222 tty->print_cr("pd set = #%d", count);
223 }
224 };
225
226 // Entry in a SymbolPropertyTable, mapping a single Symbol*
227 // to a managed and an unmanaged pointer.
228 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
229 friend class VMStructs;
230 private:
231 intptr_t _symbol_mode; // secondary key
232 Method* _method;
233 oop _method_type;
234
235 public:
236 Symbol* symbol() const { return literal(); }
237
238 intptr_t symbol_mode() const { return _symbol_mode; }
239 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
240
241 Method* method() const { return _method; }
242 void set_method(Method* p) { _method = p; }
243
244 oop method_type() const { return _method_type; }
245 oop* method_type_addr() { return &_method_type; }
246 void set_method_type(oop p) { _method_type = p; }
247
248 SymbolPropertyEntry* next() const {
249 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
250 }
251
252 SymbolPropertyEntry** next_addr() {
253 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
254 }
255
256 void print_on(outputStream* st) const {
257 symbol()->print_value_on(st);
258 st->print("/mode="INTX_FORMAT, symbol_mode());
259 st->print(" -> ");
260 bool printed = false;
261 if (method() != NULL) {
262 method()->print_value_on(st);
263 printed = true;
264 }
265 if (method_type() != NULL) {
266 if (printed) st->print(" and ");
267 st->print(INTPTR_FORMAT, method_type());
268 printed = true;
269 }
270 st->print_cr(printed ? "" : "(empty)");
271 }
272 };
273
274 // A system-internal mapping of symbols to pointers, both managed
275 // and unmanaged. Used to record the auto-generation of each method
276 // MethodHandle.invoke(S)T, for all signatures (S)T.
277 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
278 friend class VMStructs;
279 private:
280 SymbolPropertyEntry* bucket(int i) {
281 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
282 }
283
284 // The following method is not MT-safe and must be done under lock.
285 SymbolPropertyEntry** bucket_addr(int i) {
286 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
287 }
288
289 void add_entry(int index, SymbolPropertyEntry* new_entry) {
290 ShouldNotReachHere();
291 }
292 void set_entry(int index, SymbolPropertyEntry* new_entry) {
293 ShouldNotReachHere();
294 }
295
296 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
297 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
298 // Hashtable with Symbol* literal must increment and decrement refcount.
299 symbol->increment_refcount();
300 entry->set_symbol_mode(symbol_mode);
301 entry->set_method(NULL);
302 entry->set_method_type(NULL);
303 return entry;
304 }
305
306 public:
307 SymbolPropertyTable(int table_size);
308 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
309
310 void free_entry(SymbolPropertyEntry* entry) {
311 // decrement Symbol refcount here because hashtable doesn't.
312 entry->literal()->decrement_refcount();
313 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
314 }
315
316 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
317 // Use the regular identity_hash.
318 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
319 }
320
321 int index_for(Symbol* name, intptr_t symbol_mode) {
322 return hash_to_index(compute_hash(name, symbol_mode));
323 }
324
325 // need not be locked; no state change
326 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
327
328 // must be done under SystemDictionary_lock
329 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
330
331 // GC support
332 void oops_do(OopClosure* f);
333
334 void methods_do(void f(Method*));
335
336 // Sharing support
337 void reorder_dictionary();
338
339 #ifndef PRODUCT
340 void print();
341 #endif
342 void verify();
343 };
344 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP