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 TwoOopHashtable<InstanceKlass*, mtClass> {
43 friend class VMStructs;
44 private:
45 // current iteration index.
46 static int _current_class_index;
47 // pointer to the current hash table entry.
48 static DictionaryEntry* _current_class_entry;
49
50 ProtectionDomainCacheTable* _pd_cache_table;
51
52 DictionaryEntry* get_entry(int index, unsigned int hash,
53 Symbol* name, ClassLoaderData* loader_data);
54
55 protected:
56 DictionaryEntry* bucket(int i) const {
57 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
58 }
59
60 // The following method is not MT-safe and must be done under lock.
61 DictionaryEntry** bucket_addr(int i) {
62 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
63 }
64
65 void add_entry(int index, DictionaryEntry* new_entry) {
66 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
67 }
68
69 static size_t entry_size();
70 public:
71 Dictionary(int table_size);
72 Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
73
74 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass, ClassLoaderData* loader_data);
75
76 void free_entry(DictionaryEntry* entry);
77
78 void add_klass(Symbol* class_name, ClassLoaderData* loader_data, InstanceKlass* obj);
79
80 InstanceKlass* find_class(int index, unsigned int hash,
81 Symbol* name, ClassLoaderData* loader_data);
82
83 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
84
85 // Compiler support
86 InstanceKlass* try_get_next_class();
87
88 // GC support
89 void oops_do(OopClosure* f);
90 void roots_oops_do(OopClosure* strong, OopClosure* weak);
91
92 void classes_do(void f(Klass*));
93 void classes_do(void f(Klass*, TRAPS), TRAPS);
94 void classes_do(void f(Klass*, ClassLoaderData*));
95
96 void unlink(BoolObjectClosure* is_alive);
97 void remove_classes_in_error_state();
98
99 // Classes loaded by the bootstrap loader are always strongly reachable.
100 // If we're not doing class unloading, all classes are strongly reachable.
101 static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {
102 assert (klass != NULL, "should have non-null klass");
103 return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);
104 }
105
106 // Unload (that is, break root links to) all unmarked classes and loaders.
107 void do_unloading();
108
109 // Protection domains
110 InstanceKlass* find(int index, unsigned int hash, Symbol* name,
111 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
112 bool is_valid_protection_domain(int index, unsigned int hash,
113 Symbol* name, ClassLoaderData* loader_data,
114 Handle protection_domain);
115 void add_protection_domain(int index, unsigned int hash,
116 InstanceKlass* klass, ClassLoaderData* loader_data,
117 Handle protection_domain, TRAPS);
118
119 // Sharing support
120 void reorder_dictionary();
121
122 ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
123
124 void print(bool details = true);
125 #ifdef ASSERT
126 void printPerformanceInfoDetails();
127 #endif // ASSERT
128 void verify();
129 };
130
131 // An entry in the system dictionary, this describes a class as
132 // { InstanceKlass*, loader, protection_domain }.
133
134 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
135 friend class VMStructs;
136 private:
137 // Contains the set of approved protection domains that can access
138 // this system dictionary entry.
139 //
140 // This protection domain set is a set of tuples:
141 //
142 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
143 //
144 // [Note that C.protection_domain(), which is stored in the java.lang.Class
145 // mirror of C, is NOT the same as PD]
146 //
147 // If such an entry (C, ICL, PD) exists in the table, it means that
148 // it is okay for a class Foo to reference C, where
149 //
150 // Foo.protection_domain() == PD, and
151 // Foo's defining class loader == ICL
152 //
153 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
154 // It is essentially a cache to avoid repeated Java up-calls to
155 // ClassLoader.checkPackageAccess().
156 //
157 ProtectionDomainEntry* _pd_set;
158 ClassLoaderData* _loader_data;
159
160 public:
161 // Tells whether a protection is in the approved set.
162 bool contains_protection_domain(oop protection_domain) const;
163 // Adds a protection domain to the approved set.
164 void add_protection_domain(Dictionary* dict, Handle protection_domain);
165
166 InstanceKlass* klass() const { return (InstanceKlass*)literal(); }
167
168 DictionaryEntry* next() const {
169 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
170 }
171
172 DictionaryEntry** next_addr() {
173 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
174 }
175
176 ClassLoaderData* loader_data() const { return _loader_data; }
177 void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }
178
179 ProtectionDomainEntry* pd_set() const { return _pd_set; }
180 void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
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 void verify_protection_domain_set() {
193 for (ProtectionDomainEntry* current = _pd_set;
194 current != NULL;
195 current = current->_next) {
196 current->_pd_cache->protection_domain()->verify();
197 }
198 }
199
200 bool equals(const Symbol* class_name, ClassLoaderData* loader_data) const {
201 InstanceKlass* klass = (InstanceKlass*)literal();
202 return (klass->name() == class_name && _loader_data == loader_data);
203 }
204
205 void print_count(outputStream *st) {
206 int count = 0;
207 for (ProtectionDomainEntry* current = _pd_set;
208 current != NULL;
209 current = current->_next) {
210 count++;
211 }
212 st->print_cr("pd set count = #%d", count);
213 }
214
215 void verify();
216 };
217
218 // Entry in a SymbolPropertyTable, mapping a single Symbol*
219 // to a managed and an unmanaged pointer.
220 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
221 friend class VMStructs;
222 private:
223 intptr_t _symbol_mode; // secondary key
224 Method* _method;
225 oop _method_type;
226
227 public:
228 Symbol* symbol() const { return literal(); }
229
230 intptr_t symbol_mode() const { return _symbol_mode; }
231 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
232
233 Method* method() const { return _method; }
234 void set_method(Method* p) { _method = p; }
235
236 oop method_type() const { return _method_type; }
237 oop* method_type_addr() { return &_method_type; }
238 void set_method_type(oop p) { _method_type = p; }
239
240 SymbolPropertyEntry* next() const {
241 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
242 }
243
244 SymbolPropertyEntry** next_addr() {
245 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
246 }
247
248 void print_on(outputStream* st) const {
249 symbol()->print_value_on(st);
250 st->print("/mode=" INTX_FORMAT, symbol_mode());
251 st->print(" -> ");
252 bool printed = false;
253 if (method() != NULL) {
254 method()->print_value_on(st);
255 printed = true;
256 }
257 if (method_type() != NULL) {
258 if (printed) st->print(" and ");
259 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
260 printed = true;
261 }
262 st->print_cr(printed ? "" : "(empty)");
263 }
264 };
265
266 // A system-internal mapping of symbols to pointers, both managed
267 // and unmanaged. Used to record the auto-generation of each method
268 // MethodHandle.invoke(S)T, for all signatures (S)T.
269 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
270 friend class VMStructs;
271 private:
272 SymbolPropertyEntry* bucket(int i) {
273 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
274 }
275
276 // The following method is not MT-safe and must be done under lock.
277 SymbolPropertyEntry** bucket_addr(int i) {
278 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
279 }
280
281 void add_entry(int index, SymbolPropertyEntry* new_entry) {
282 ShouldNotReachHere();
283 }
284 void set_entry(int index, SymbolPropertyEntry* new_entry) {
285 ShouldNotReachHere();
286 }
287
288 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
289 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
290 // Hashtable with Symbol* literal must increment and decrement refcount.
291 symbol->increment_refcount();
292 entry->set_symbol_mode(symbol_mode);
293 entry->set_method(NULL);
294 entry->set_method_type(NULL);
295 return entry;
296 }
297
298 public:
299 SymbolPropertyTable(int table_size);
300 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
301
302 void free_entry(SymbolPropertyEntry* entry) {
303 // decrement Symbol refcount here because hashtable doesn't.
304 entry->literal()->decrement_refcount();
305 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
306 }
307
308 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
309 // Use the regular identity_hash.
310 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
311 }
312
313 int index_for(Symbol* name, intptr_t symbol_mode) {
314 return hash_to_index(compute_hash(name, symbol_mode));
315 }
316
317 // need not be locked; no state change
318 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
319
320 // must be done under SystemDictionary_lock
321 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
322
323 // GC support
324 void oops_do(OopClosure* f);
325
326 void methods_do(void f(Method*));
327
328 // Sharing support
329 void reorder_dictionary();
330
331 #ifndef PRODUCT
332 void print();
333 #endif
334 void verify();
335 };
336 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP