1 /*
2 * Copyright (c) 2003, 2017, 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.
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_DICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_DICTIONARY_HPP
27
28 #include "classfile/protectionDomainCache.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/oop.hpp"
32 #include "utilities/hashtable.hpp"
33 #include "utilities/ostream.hpp"
34
35 class DictionaryEntry;
36 class BoolObjectClosure;
37
38 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39 // The data structure for the system dictionary (and the shared system
40 // dictionary).
41
42 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
43 friend class VMStructs;
44
45 ClassLoaderData* _loader_data; // backpointer to owning loader
46 ClassLoaderData* loader_data() const { return _loader_data; }
47
48 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
49
50 protected:
51 DictionaryEntry* bucket(int i) const {
52 return (DictionaryEntry*)Hashtable<InstanceKlass*, 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<InstanceKlass*, mtClass>::bucket_addr(i);
58 }
59
60 void add_entry(int index, DictionaryEntry* new_entry) {
61 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
62 }
63
64 void free_entry(DictionaryEntry* entry);
65
66 static size_t entry_size();
67 public:
68 Dictionary(ClassLoaderData* loader_data, int table_size);
69 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
70 ~Dictionary();
71
72 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
73
74 void add_klass(int index, unsigned int hash, Symbol* class_name, InstanceKlass* obj);
75
76 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
77
78 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
79
80 // GC support
81 void oops_do(OopClosure* f);
82 void roots_oops_do(OopClosure* strong, OopClosure* weak);
83
84 void classes_do(void f(InstanceKlass*));
85 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
86 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
87
88 void unlink(BoolObjectClosure* is_alive);
89 void remove_classes_in_error_state();
90
91 // Unload classes whose defining loaders are unloaded
92 void do_unloading();
93
94 // Protection domains
95 InstanceKlass* find(int index, unsigned int hash, Symbol* name, Handle protection_domain);
96 bool is_valid_protection_domain(int index, unsigned int hash,
97 Symbol* name,
98 Handle protection_domain);
99 void add_protection_domain(int index, unsigned int hash,
100 InstanceKlass* klass,
101 Handle protection_domain, TRAPS);
102
103 // Sharing support
104 void reorder_dictionary();
105
106 void print(bool details = true);
107 #ifdef ASSERT
108 void printPerformanceInfoDetails();
109 #endif // ASSERT
110 void verify();
111 };
112
113 // An entry in the system dictionary, this describes a class as
114 // { InstanceKlass*, loader, protection_domain }.
115
116 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
117 friend class VMStructs;
118 private:
119 // Contains the set of approved protection domains that can access
120 // this system dictionary entry.
121 //
122 // This protection domain set is a set of tuples:
123 //
124 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
125 //
126 // [Note that C.protection_domain(), which is stored in the java.lang.Class
127 // mirror of C, is NOT the same as PD]
128 //
129 // If such an entry (C, ICL, PD) exists in the table, it means that
130 // it is okay for a class Foo to reference C, where
131 //
132 // Foo.protection_domain() == PD, and
133 // Foo's defining class loader == ICL
134 //
135 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
136 // It is essentially a cache to avoid repeated Java up-calls to
137 // ClassLoader.checkPackageAccess().
138 //
139 ProtectionDomainEntry* _pd_set;
140
141 public:
142 // Tells whether a protection is in the approved set.
143 bool contains_protection_domain(oop protection_domain) const;
144 // Adds a protection domain to the approved set.
145 void add_protection_domain(Dictionary* dict, Handle protection_domain);
146
147 InstanceKlass* klass() const { return (InstanceKlass*)literal(); }
148
149 DictionaryEntry* next() const {
150 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
151 }
152
153 DictionaryEntry** next_addr() {
154 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
155 }
156
157 ProtectionDomainEntry* pd_set() const { return _pd_set; }
158 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
159
160 // Tells whether the initiating class' protection can access the this _klass
161 bool is_valid_protection_domain(Handle protection_domain) {
162 if (!ProtectionDomainVerification) return true;
163 if (!SystemDictionary::has_checkPackageAccess()) return true;
164
165 return protection_domain() == NULL
166 ? true
167 : contains_protection_domain(protection_domain());
168 }
169
170 void verify_protection_domain_set() {
171 for (ProtectionDomainEntry* current = _pd_set;
172 current != NULL;
173 current = current->_next) {
174 current->_pd_cache->protection_domain()->verify();
175 }
176 }
177
178 bool equals(const Symbol* class_name) const {
179 InstanceKlass* klass = (InstanceKlass*)literal();
180 return (klass->name() == class_name);
181 }
182
183 void print_count(outputStream *st) {
184 int count = 0;
185 for (ProtectionDomainEntry* current = _pd_set;
186 current != NULL;
187 current = current->_next) {
188 count++;
189 }
190 st->print_cr("pd set count = #%d", count);
191 }
192
193 void verify();
194 };
195
196 // Entry in a SymbolPropertyTable, mapping a single Symbol*
197 // to a managed and an unmanaged pointer.
198 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
199 friend class VMStructs;
200 private:
201 intptr_t _symbol_mode; // secondary key
202 Method* _method;
203 oop _method_type;
204
205 public:
206 Symbol* symbol() const { return literal(); }
207
208 intptr_t symbol_mode() const { return _symbol_mode; }
209 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
210
211 Method* method() const { return _method; }
212 void set_method(Method* p) { _method = p; }
213
214 oop method_type() const { return _method_type; }
215 oop* method_type_addr() { return &_method_type; }
216 void set_method_type(oop p) { _method_type = p; }
217
218 SymbolPropertyEntry* next() const {
219 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
220 }
221
222 SymbolPropertyEntry** next_addr() {
223 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
224 }
225
226 void print_on(outputStream* st) const {
227 symbol()->print_value_on(st);
228 st->print("/mode=" INTX_FORMAT, symbol_mode());
229 st->print(" -> ");
230 bool printed = false;
231 if (method() != NULL) {
232 method()->print_value_on(st);
233 printed = true;
234 }
235 if (method_type() != NULL) {
236 if (printed) st->print(" and ");
237 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
238 printed = true;
239 }
240 st->print_cr(printed ? "" : "(empty)");
241 }
242 };
243
244 // A system-internal mapping of symbols to pointers, both managed
245 // and unmanaged. Used to record the auto-generation of each method
246 // MethodHandle.invoke(S)T, for all signatures (S)T.
247 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
248 friend class VMStructs;
249 private:
250 SymbolPropertyEntry* bucket(int i) {
251 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
252 }
253
254 // The following method is not MT-safe and must be done under lock.
255 SymbolPropertyEntry** bucket_addr(int i) {
256 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
257 }
258
259 void add_entry(int index, SymbolPropertyEntry* new_entry) {
260 ShouldNotReachHere();
261 }
262 void set_entry(int index, SymbolPropertyEntry* new_entry) {
263 ShouldNotReachHere();
264 }
265
266 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
267 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
268 // Hashtable with Symbol* literal must increment and decrement refcount.
269 symbol->increment_refcount();
270 entry->set_symbol_mode(symbol_mode);
271 entry->set_method(NULL);
272 entry->set_method_type(NULL);
273 return entry;
274 }
275
276 public:
277 SymbolPropertyTable(int table_size);
278 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
279
280 void free_entry(SymbolPropertyEntry* entry) {
281 // decrement Symbol refcount here because hashtable doesn't.
282 entry->literal()->decrement_refcount();
283 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
284 }
285
286 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
287 // Use the regular identity_hash.
288 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
289 }
290
291 int index_for(Symbol* name, intptr_t symbol_mode) {
292 return hash_to_index(compute_hash(name, symbol_mode));
293 }
294
295 // need not be locked; no state change
296 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
297
298 // must be done under SystemDictionary_lock
299 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
300
301 // GC support
302 void oops_do(OopClosure* f);
303
304 void methods_do(void f(Method*));
305
306 // Sharing support
307 void reorder_dictionary();
308
309 #ifndef PRODUCT
310 void print();
311 #endif
312 void verify();
313 };
314 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP