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.
22 *
23 */
24
25 #ifndef SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP
26 #define SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP
27
28 #include "classfile/dictionary.hpp"
29 #include "classfile/placeholders.hpp"
30 #include "utilities/hashtable.hpp"
31
32 class LoaderConstraintEntry;
33 class Symbol;
34
35 class LoaderConstraintTable : public Hashtable<InstanceKlass*, mtClass> {
36 friend class VMStructs;
37 private:
38
39 enum Constants {
40 _loader_constraint_size = 107, // number of entries in constraint table
41 _nof_buckets = 1009 // number of buckets in hash table
42 };
43
44 LoaderConstraintEntry** find_loader_constraint(Symbol* name,
45 Handle loader);
46
47 public:
48
49 LoaderConstraintTable(int nof_buckets);
50
51 LoaderConstraintEntry* new_entry(unsigned int hash, Symbol* name,
52 InstanceKlass* klass, int num_loaders,
53 int max_loaders);
54 void free_entry(LoaderConstraintEntry *entry);
55
56 LoaderConstraintEntry* bucket(int i) {
57 return (LoaderConstraintEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
58 }
59
60 LoaderConstraintEntry** bucket_addr(int i) {
61 return (LoaderConstraintEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
62 }
63
64 // Enhanced Class Redefinition support
65 void classes_do(KlassClosure* f);
66
67 // Check class loader constraints
68 bool add_entry(Symbol* name, InstanceKlass* klass1, Handle loader1,
69 InstanceKlass* klass2, Handle loader2);
70
71 // Note: The main entry point for this module is via SystemDictionary.
72 // SystemDictionary::check_signature_loaders(Symbol* signature,
73 // Handle loader1, Handle loader2,
74 // bool is_method, TRAPS)
75
76 InstanceKlass* find_constrained_klass(Symbol* name, Handle loader);
77
78 // Class loader constraints
79
80 void ensure_loader_constraint_capacity(LoaderConstraintEntry *p, int nfree);
81 void extend_loader_constraint(LoaderConstraintEntry* p, Handle loader,
82 InstanceKlass* klass);
83 void merge_loader_constraints(LoaderConstraintEntry** pp1,
84 LoaderConstraintEntry** pp2, InstanceKlass* klass);
85
86 bool check_or_update(InstanceKlass* k, Handle loader, Symbol* name);
87
88 void purge_loader_constraints();
89
90 void verify(Dictionary* dictionary, PlaceholderTable* placeholders);
91 #ifndef PRODUCT
92 void print();
93 #endif
94 };
95
96 class LoaderConstraintEntry : public HashtableEntry<InstanceKlass*, mtClass> {
97 friend class VMStructs;
98 private:
99 Symbol* _name; // class name
100 int _num_loaders;
101 int _max_loaders;
102 // Loader constraints enforce correct linking behavior.
103 // Thus, it really operates on ClassLoaderData which represents linking domain,
104 // not class loaders.
105 ClassLoaderData** _loaders; // initiating loaders
106
107 public:
108
109 InstanceKlass* klass() { return literal(); }
110 InstanceKlass** klass_addr() { return literal_addr(); }
111 void set_klass(InstanceKlass* k) { set_literal(k); }
112
113 LoaderConstraintEntry* next() {
114 return (LoaderConstraintEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
115 }
116
117 LoaderConstraintEntry** next_addr() {
118 return (LoaderConstraintEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
119 }
120 void set_next(LoaderConstraintEntry* next) {
121 HashtableEntry<InstanceKlass*, mtClass>::set_next(next);
122 }
123
124 Symbol* name() { return _name; }
125 void set_name(Symbol* name) {
126 _name = name;
127 if (name != NULL) name->increment_refcount();
128 }
129
130 int num_loaders() { return _num_loaders; }
131 void set_num_loaders(int i) { _num_loaders = i; }
132
133 int max_loaders() { return _max_loaders; }
134 void set_max_loaders(int i) { _max_loaders = i; }
135
136 ClassLoaderData** loaders() { return _loaders; }
137 void set_loaders(ClassLoaderData** loaders) { _loaders = loaders; }
138
139 ClassLoaderData* loader_data(int i) { return _loaders[i]; }
140 void set_loader_data(int i, ClassLoaderData* p) { _loaders[i] = p; }
141 // convenience
142 void set_loader(int i, oop p);
143 };
144
145 #endif // SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP