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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<Klass*, 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                                    Klass* klass, int num_loaders,
53                                    int max_loaders);
54   void free_entry(LoaderConstraintEntry *entry);
55 
bucket(int i)56   LoaderConstraintEntry* bucket(int i) {
57     return (LoaderConstraintEntry*)Hashtable<Klass*, mtClass>::bucket(i);
58   }
59 
bucket_addr(int i)60   LoaderConstraintEntry** bucket_addr(int i) {
61     return (LoaderConstraintEntry**)Hashtable<Klass*, 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, Klass* klass1, Handle loader1,
69                                     Klass* 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   Klass* 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                                 Klass* klass);
83   void merge_loader_constraints(LoaderConstraintEntry** pp1,
84                                 LoaderConstraintEntry** pp2, Klass* klass);
85 
86   bool check_or_update(instanceKlassHandle k, Handle loader,
87                               Symbol* name);
88 
89 
90   void purge_loader_constraints();
91 
92   void verify(Dictionary* dictionary, PlaceholderTable* placeholders);
93 #ifndef PRODUCT
94   void print();
95 #endif
96 };
97 
98 class LoaderConstraintEntry : public HashtableEntry<Klass*, mtClass> {
99   friend class VMStructs;
100 private:
101   Symbol*                _name;                   // class name
102   int                    _num_loaders;
103   int                    _max_loaders;
104   // Loader constraints enforce correct linking behavior.
105   // Thus, it really operates on ClassLoaderData which represents linking domain,
106   // not class loaders.
107   ClassLoaderData**              _loaders;                // initiating loaders
108 
109 public:
110 
klass()111   Klass* klass() { return literal(); }
klass_addr()112   Klass** klass_addr() { return literal_addr(); }
set_klass(Klass * k)113   void set_klass(Klass* k) { set_literal(k); }
114 
next()115   LoaderConstraintEntry* next() {
116     return (LoaderConstraintEntry*)HashtableEntry<Klass*, mtClass>::next();
117   }
118 
next_addr()119   LoaderConstraintEntry** next_addr() {
120     return (LoaderConstraintEntry**)HashtableEntry<Klass*, mtClass>::next_addr();
121   }
set_next(LoaderConstraintEntry * next)122   void set_next(LoaderConstraintEntry* next) {
123     HashtableEntry<Klass*, mtClass>::set_next(next);
124   }
125 
name()126   Symbol* name() { return _name; }
set_name(Symbol * name)127   void set_name(Symbol* name) {
128     _name = name;
129     if (name != NULL) name->increment_refcount();
130   }
131 
num_loaders()132   int num_loaders() { return _num_loaders; }
set_num_loaders(int i)133   void set_num_loaders(int i) { _num_loaders = i; }
134 
max_loaders()135   int max_loaders() { return _max_loaders; }
set_max_loaders(int i)136   void set_max_loaders(int i) { _max_loaders = i; }
137 
loaders()138   ClassLoaderData** loaders() { return _loaders; }
set_loaders(ClassLoaderData ** loaders)139   void set_loaders(ClassLoaderData** loaders) { _loaders = loaders; }
140 
loader_data(int i)141   ClassLoaderData* loader_data(int i) { return _loaders[i]; }
set_loader_data(int i,ClassLoaderData * p)142   void set_loader_data(int i, ClassLoaderData* p) { _loaders[i] = p; }
143   // convenience
144   void set_loader(int i, oop p);
145 };
146 
147 #endif // SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP
148