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 "runtime/orderAccess.hpp"
33 #include "utilities/hashtable.hpp"
34 #include "utilities/ostream.hpp"
35
36 class DictionaryEntry;
37 class BoolObjectClosure;
38
39 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 // The data structure for the class loader data dictionaries (and the shared system
41 // dictionary).
42
43 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
44 friend class VMStructs;
45
46 ClassLoaderData* _loader_data; // backpointer to owning loader
47 ClassLoaderData* loader_data() const { return _loader_data; }
48
49 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
50
51 protected:
52 DictionaryEntry* bucket(int i) const {
53 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
54 }
55
56 // The following method is not MT-safe and must be done under lock.
57 DictionaryEntry** bucket_addr(int i) {
58 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
59 }
60
61 void add_entry(int index, DictionaryEntry* new_entry) {
62 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
63 }
64
65 void free_entry(DictionaryEntry* entry);
66
67 static size_t entry_size();
68 public:
69 Dictionary(ClassLoaderData* loader_data, int table_size);
70 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries);
71 ~Dictionary();
72
73 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
74
75 void add_klass(int index, unsigned int hash, Symbol* class_name, InstanceKlass* obj);
76
77 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
78
79 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
80
81 // GC support
82 void oops_do(OopClosure* f);
83 void roots_oops_do(OopClosure* strong, OopClosure* weak);
84
85 void classes_do(void f(InstanceKlass*));
86 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
87 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
88 void classes_do(MetaspaceClosure* it);
89
90 void unlink(BoolObjectClosure* is_alive);
91 void remove_classes_in_error_state();
92
93 // Unload classes whose defining loaders are unloaded
94 void do_unloading();
95
96 // Protection domains
97 InstanceKlass* find(int index, unsigned int hash, Symbol* name, Handle protection_domain);
98 bool is_valid_protection_domain(int index, unsigned int hash,
99 Symbol* name,
100 Handle protection_domain);
101 void add_protection_domain(int index, unsigned int hash,
102 InstanceKlass* klass,
103 Handle protection_domain, TRAPS);
104
105 // Sharing support
106 void reorder_dictionary_for_sharing();
107
108 void print_on(outputStream* st) const;
109 void verify();
110 };
111
112 // An entry in the class loader data dictionaries, this describes a class as
113 // { InstanceKlass*, protection_domain }.
114
115 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
116 friend class VMStructs;
117 private:
118 // Contains the set of approved protection domains that can access
119 // this dictionary entry.
120 //
121 // This protection domain set is a set of tuples:
122 //
123 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
124 //
125 // [Note that C.protection_domain(), which is stored in the java.lang.Class
126 // mirror of C, is NOT the same as PD]
127 //
128 // If such an entry (C, ICL, PD) exists in the table, it means that
129 // it is okay for a class Foo to reference C, where
130 //
131 // Foo.protection_domain() == PD, and
132 // Foo's defining class loader == ICL
133 //
134 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
135 // It is essentially a cache to avoid repeated Java up-calls to
136 // ClassLoader.checkPackageAccess().
137 //
138 class ProtectionDomainSet {
139 // Do not access without synchronization
140 ProtectionDomainEntry* volatile _pd_set;
141 public:
142 ProtectionDomainEntry* pd_set() const {
143 return (ProtectionDomainEntry*)OrderAccess::load_ptr_acquire(&_pd_set);
144 }
145 void set_pd_set(ProtectionDomainEntry* new_head) {
146 // Warning: Preserve store ordering. The SystemDictionary is read
147 // without locks. The new ProtectionDomainEntry must be
148 // complete before other threads can be allowed to see it
149 // via a store to _pd_set.
150 OrderAccess::release_store_ptr(&_pd_set, new_head);
151 }
152 };
153
154 ProtectionDomainSet _inner;
155
156 public:
157 // Tells whether a protection is in the approved set.
158 bool contains_protection_domain(oop protection_domain) const;
159 // Adds a protection domain to the approved set.
160 void add_protection_domain(Dictionary* dict, Handle protection_domain);
161
162 InstanceKlass* instance_klass() const { return literal(); }
163 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
164
165 DictionaryEntry* next() const {
166 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
167 }
168
169 DictionaryEntry** next_addr() {
170 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
171 }
172
173 ProtectionDomainEntry* pd_set() const { return _inner.pd_set(); }
174 void set_pd_set(ProtectionDomainEntry* new_head) { _inner.set_pd_set(new_head); }
175
176 // Tells whether the initiating class' protection domain can access the klass in this entry
177 bool is_valid_protection_domain(Handle protection_domain) {
178 if (!ProtectionDomainVerification) return true;
179 if (!SystemDictionary::has_checkPackageAccess()) return true;
180
181 return protection_domain() == NULL
182 ? true
183 : contains_protection_domain(protection_domain());
184 }
185
186 void verify_protection_domain_set() {
187 for (ProtectionDomainEntry* current = pd_set();
188 current != NULL;
189 current = current->_next) {
190 current->_pd_cache->protection_domain()->verify();
191 }
192 }
193
194 bool equals(const Symbol* class_name) const {
195 InstanceKlass* klass = (InstanceKlass*)literal();
196 return (klass->name() == class_name);
197 }
198
199 void print_count(outputStream *st) {
200 int count = 0;
201 for (ProtectionDomainEntry* current = pd_set();
202 current != NULL;
203 current = current->_next) {
204 count++;
205 }
206 st->print_cr("pd set count = #%d", count);
207 }
208
209 void verify();
210 };
211
212 // Entry in a SymbolPropertyTable, mapping a single Symbol*
213 // to a managed and an unmanaged pointer.
214 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
215 friend class VMStructs;
216 private:
217 intptr_t _symbol_mode; // secondary key
218 Method* _method;
219 oop _method_type;
220
221 public:
222 Symbol* symbol() const { return literal(); }
223
224 intptr_t symbol_mode() const { return _symbol_mode; }
225 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
226
227 Method* method() const { return _method; }
228 void set_method(Method* p) { _method = p; }
229
230 oop method_type() const { return _method_type; }
231 oop* method_type_addr() { return &_method_type; }
232 void set_method_type(oop p) { _method_type = p; }
233
234 SymbolPropertyEntry* next() const {
235 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
236 }
237
238 SymbolPropertyEntry** next_addr() {
239 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
240 }
241
242 void print_entry(outputStream* st) const {
243 symbol()->print_value_on(st);
244 st->print("/mode=" INTX_FORMAT, symbol_mode());
245 st->print(" -> ");
246 bool printed = false;
247 if (method() != NULL) {
248 method()->print_value_on(st);
249 printed = true;
250 }
251 if (method_type() != NULL) {
252 if (printed) st->print(" and ");
253 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
254 printed = true;
255 }
256 st->print_cr(printed ? "" : "(empty)");
257 }
258 };
259
260 // A system-internal mapping of symbols to pointers, both managed
261 // and unmanaged. Used to record the auto-generation of each method
262 // MethodHandle.invoke(S)T, for all signatures (S)T.
263 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
264 friend class VMStructs;
265 private:
266 SymbolPropertyEntry* bucket(int i) {
267 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
268 }
269
270 // The following method is not MT-safe and must be done under lock.
271 SymbolPropertyEntry** bucket_addr(int i) {
272 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
273 }
274
275 void add_entry(int index, SymbolPropertyEntry* new_entry) {
276 ShouldNotReachHere();
277 }
278 void set_entry(int index, SymbolPropertyEntry* new_entry) {
279 ShouldNotReachHere();
280 }
281
282 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
283 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
284 // Hashtable with Symbol* literal must increment and decrement refcount.
285 symbol->increment_refcount();
286 entry->set_symbol_mode(symbol_mode);
287 entry->set_method(NULL);
288 entry->set_method_type(NULL);
289 return entry;
290 }
291
292 public:
293 SymbolPropertyTable(int table_size);
294 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
295
296 void free_entry(SymbolPropertyEntry* entry) {
297 // decrement Symbol refcount here because hashtable doesn't.
298 entry->literal()->decrement_refcount();
299 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
300 }
301
302 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
303 // Use the regular identity_hash.
304 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
305 }
306
307 int index_for(Symbol* name, intptr_t symbol_mode) {
308 return hash_to_index(compute_hash(name, symbol_mode));
309 }
310
311 // need not be locked; no state change
312 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
313
314 // must be done under SystemDictionary_lock
315 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
316
317 // GC support
318 void oops_do(OopClosure* f);
319
320 void methods_do(void f(Method*));
321
322 void verify();
323 };
324 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP