1 /*
2 * Copyright (c) 2003, 2018, 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 class loader data dictionaries (and the shared system
40 // dictionary).
41
42 class Dictionary : public Hashtable<InstanceKlass*, mtClass> {
43 friend class VMStructs;
44
45 static bool _some_dictionary_needs_resizing;
46 bool _resizable;
47 bool _needs_resizing;
48 void check_if_needs_resize();
49
50 ClassLoaderData* _loader_data; // backpointer to owning loader
51 ClassLoaderData* loader_data() const { return _loader_data; }
52
53 DictionaryEntry* get_entry(int index, unsigned int hash, Symbol* name);
54
55 void clean_cached_protection_domains(BoolObjectClosure* is_alive, DictionaryEntry* probe);
56
57 protected:
58 static size_t entry_size();
59 public:
60 Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable = false);
61 Dictionary(ClassLoaderData* loader_data, int table_size, HashtableBucket<mtClass>* t, int number_of_entries, bool resizable = false);
62 ~Dictionary();
63
64 static bool does_any_dictionary_needs_resizing();
65 bool resize_if_needed();
66
67 DictionaryEntry* new_entry(unsigned int hash, InstanceKlass* klass);
68
69 void add_klass(unsigned int hash, Symbol* class_name, InstanceKlass* obj);
70
71 InstanceKlass* find_class(int index, unsigned int hash, Symbol* name);
72
73 InstanceKlass* find_shared_class(int index, unsigned int hash, Symbol* name);
74
75 // GC support
76 void oops_do(OopClosure* f);
77 void roots_oops_do(OopClosure* strong, OopClosure* weak);
78
79 void classes_do(void f(InstanceKlass*));
80 void classes_do(void f(InstanceKlass*, TRAPS), TRAPS);
81 void all_entries_do(void f(InstanceKlass*, ClassLoaderData*));
82 void classes_do(MetaspaceClosure* it);
83
84 void unlink(BoolObjectClosure* is_alive);
85 void remove_classes_in_error_state();
86
87 // Unload classes whose defining loaders are unloaded
88 void do_unloading(BoolObjectClosure* is_alive);
89
90 // Protection domains
91 InstanceKlass* find(unsigned int hash, Symbol* name, Handle protection_domain);
92 bool is_valid_protection_domain(unsigned int hash,
93 Symbol* name,
94 Handle protection_domain);
95 void add_protection_domain(int index, unsigned int hash,
96 InstanceKlass* klass,
97 Handle protection_domain, TRAPS);
98
99 // Sharing support
100 void reorder_dictionary_for_sharing() NOT_CDS_RETURN;
101
102 void print_on(outputStream* st) const;
103 void verify();
104 DictionaryEntry* bucket(int i) const {
105 return (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
106 }
107
108 // The following method is not MT-safe and must be done under lock.
109 DictionaryEntry** bucket_addr(int i) {
110 return (DictionaryEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
111 }
112
113 void add_entry(int index, DictionaryEntry* new_entry) {
114 Hashtable<InstanceKlass*, mtClass>::add_entry(index, (HashtableEntry<InstanceKlass*, mtClass>*)new_entry);
115 }
116
117 void unlink_entry(DictionaryEntry* entry) {
118 Hashtable<InstanceKlass*, mtClass>::unlink_entry((HashtableEntry<InstanceKlass*, mtClass>*)entry);
119 }
120
121 void free_entry(DictionaryEntry* entry);
122 };
123
124 // An entry in the class loader data dictionaries, this describes a class as
125 // { InstanceKlass*, protection_domain }.
126
127 class DictionaryEntry : public HashtableEntry<InstanceKlass*, mtClass> {
128 friend class VMStructs;
129 private:
130 // Contains the set of approved protection domains that can access
131 // this dictionary entry.
132 //
133 // This protection domain set is a set of tuples:
134 //
135 // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
136 //
137 // [Note that C.protection_domain(), which is stored in the java.lang.Class
138 // mirror of C, is NOT the same as PD]
139 //
140 // If such an entry (C, ICL, PD) exists in the table, it means that
141 // it is okay for a class Foo to reference C, where
142 //
143 // Foo.protection_domain() == PD, and
144 // Foo's defining class loader == ICL
145 //
146 // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
147 // It is essentially a cache to avoid repeated Java up-calls to
148 // ClassLoader.checkPackageAccess().
149 //
150 ProtectionDomainEntry* volatile _pd_set;
151
152 public:
153 // Tells whether a protection is in the approved set.
154 bool contains_protection_domain(oop protection_domain) const;
155 // Adds a protection domain to the approved set.
156 void add_protection_domain(Dictionary* dict, Handle protection_domain);
157
158 InstanceKlass* instance_klass() const { return literal(); }
159 InstanceKlass** klass_addr() { return (InstanceKlass**)literal_addr(); }
160
161 DictionaryEntry* next() const {
162 return (DictionaryEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
163 }
164
165 DictionaryEntry** next_addr() {
166 return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
167 }
168
169 ProtectionDomainEntry* pd_set() const { return _pd_set; }
170 void set_pd_set(ProtectionDomainEntry* new_head) { _pd_set = new_head; }
171
172 ProtectionDomainEntry* pd_set_acquire() const;
173 void release_set_pd_set(ProtectionDomainEntry* new_head);
174
175 // Tells whether the initiating class' protection domain can access the klass in this entry
176 bool is_valid_protection_domain(Handle protection_domain) {
177 if (!ProtectionDomainVerification) return true;
178 if (!SystemDictionary::has_checkPackageAccess()) return true;
179
180 return protection_domain() == NULL
181 ? true
182 : contains_protection_domain(protection_domain());
183 }
184
185 void verify_protection_domain_set() {
186 for (ProtectionDomainEntry* current = pd_set(); // accessed at a safepoint
187 current != NULL;
188 current = current->_next) {
189 current->_pd_cache->object_no_keepalive()->verify();
190 }
191 }
192
193 bool equals(const Symbol* class_name) const {
194 InstanceKlass* klass = (InstanceKlass*)literal();
195 return (klass->name() == class_name);
196 }
197
198 void print_count(outputStream *st) {
199 int count = 0;
200 for (ProtectionDomainEntry* current = pd_set(); // accessed inside SD lock
201 current != NULL;
202 current = current->_next) {
203 count++;
204 }
205 st->print_cr("pd set count = #%d", count);
206 }
207
208 void verify();
209 };
210
211 // Entry in a SymbolPropertyTable, mapping a single Symbol*
212 // to a managed and an unmanaged pointer.
213 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {
214 friend class VMStructs;
215 private:
216 intptr_t _symbol_mode; // secondary key
217 Method* _method;
218 oop _method_type;
219
220 public:
221 Symbol* symbol() const { return literal(); }
222
223 intptr_t symbol_mode() const { return _symbol_mode; }
224 void set_symbol_mode(intptr_t m) { _symbol_mode = m; }
225
226 Method* method() const { return _method; }
227 void set_method(Method* p) { _method = p; }
228
229 oop method_type() const { return _method_type; }
230 oop* method_type_addr() { return &_method_type; }
231 void set_method_type(oop p) { _method_type = p; }
232
233 SymbolPropertyEntry* next() const {
234 return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();
235 }
236
237 SymbolPropertyEntry** next_addr() {
238 return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();
239 }
240
241 void print_entry(outputStream* st) const {
242 symbol()->print_value_on(st);
243 st->print("/mode=" INTX_FORMAT, symbol_mode());
244 st->print(" -> ");
245 bool printed = false;
246 if (method() != NULL) {
247 method()->print_value_on(st);
248 printed = true;
249 }
250 if (method_type() != NULL) {
251 if (printed) st->print(" and ");
252 st->print(INTPTR_FORMAT, p2i((void *)method_type()));
253 printed = true;
254 }
255 st->print_cr(printed ? "" : "(empty)");
256 }
257 };
258
259 // A system-internal mapping of symbols to pointers, both managed
260 // and unmanaged. Used to record the auto-generation of each method
261 // MethodHandle.invoke(S)T, for all signatures (S)T.
262 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {
263 friend class VMStructs;
264 private:
265 // The following method is not MT-safe and must be done under lock.
266 SymbolPropertyEntry** bucket_addr(int i) {
267 return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);
268 }
269
270 void add_entry(int index, SymbolPropertyEntry* new_entry) {
271 ShouldNotReachHere();
272 }
273 void set_entry(int index, SymbolPropertyEntry* new_entry) {
274 ShouldNotReachHere();
275 }
276
277 SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {
278 SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);
279 // Hashtable with Symbol* literal must increment and decrement refcount.
280 symbol->increment_refcount();
281 entry->set_symbol_mode(symbol_mode);
282 entry->set_method(NULL);
283 entry->set_method_type(NULL);
284 return entry;
285 }
286
287 public:
288 SymbolPropertyTable(int table_size);
289 SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);
290
291 void free_entry(SymbolPropertyEntry* entry) {
292 // decrement Symbol refcount here because hashtable doesn't.
293 entry->literal()->decrement_refcount();
294 Hashtable<Symbol*, mtSymbol>::free_entry(entry);
295 }
296
297 unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {
298 // Use the regular identity_hash.
299 return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;
300 }
301
302 int index_for(Symbol* name, intptr_t symbol_mode) {
303 return hash_to_index(compute_hash(name, symbol_mode));
304 }
305
306 // need not be locked; no state change
307 SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
308
309 // must be done under SystemDictionary_lock
310 SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);
311
312 // GC support
313 void oops_do(OopClosure* f);
314
315 void methods_do(void f(Method*));
316
317 void verify();
318
319 SymbolPropertyEntry* bucket(int i) {
320 return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);
321 }
322 };
323 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP