1 /*
   2  * Copyright (c) 2003, 2009, 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 class LoaderConstraintEntry;
  26 
  27 class LoaderConstraintTable : public Hashtable {
  28   friend class VMStructs;
  29 private:
  30 
  31   enum Constants {
  32     _loader_constraint_size = 107,                     // number of entries in constraint table
  33     _nof_buckets            = 1009                     // number of buckets in hash table
  34   };
  35 
  36   LoaderConstraintEntry** find_loader_constraint(symbolHandle name,
  37                                                  Handle loader);
  38 
  39 public:
  40 
  41   LoaderConstraintTable(int nof_buckets);
  42 
  43   LoaderConstraintEntry* new_entry(unsigned int hash, symbolOop name,
  44                                    klassOop klass, int num_loaders,
  45                                    int max_loaders);
  46 
  47   LoaderConstraintEntry* bucket(int i) {
  48     return (LoaderConstraintEntry*)Hashtable::bucket(i);
  49   }
  50 
  51   LoaderConstraintEntry** bucket_addr(int i) {
  52     return (LoaderConstraintEntry**)Hashtable::bucket_addr(i);
  53   }
  54 
  55   // GC support
  56   void oops_do(OopClosure* f);
  57   void always_strong_classes_do(OopClosure* blk);
  58 
  59   // Check class loader constraints
  60   bool add_entry(symbolHandle name, klassOop klass1, Handle loader1,
  61                                     klassOop klass2, Handle loader2);
  62 
  63   // Note:  The main entry point for this module is via SystemDictionary.
  64   // SystemDictionary::check_signature_loaders(symbolHandle signature,
  65   //                                           Handle loader1, Handle loader2,
  66   //                                           bool is_method, TRAPS)
  67 
  68   klassOop find_constrained_klass(symbolHandle name, Handle loader);
  69 
  70   // Class loader constraints
  71 
  72   void ensure_loader_constraint_capacity(LoaderConstraintEntry *p, int nfree);
  73   void extend_loader_constraint(LoaderConstraintEntry* p, Handle loader,
  74                                 klassOop klass);
  75   void merge_loader_constraints(LoaderConstraintEntry** pp1,
  76                                 LoaderConstraintEntry** pp2, klassOop klass);
  77 
  78   bool check_or_update(instanceKlassHandle k, Handle loader,
  79                               symbolHandle name);
  80 
  81 
  82   void purge_loader_constraints(BoolObjectClosure* is_alive);
  83 
  84   void verify(Dictionary* dictionary, PlaceholderTable* placeholders);
  85 #ifndef PRODUCT
  86   void print();
  87 #endif
  88 };
  89 
  90 class LoaderConstraintEntry : public HashtableEntry {
  91   friend class VMStructs;
  92 private:
  93   symbolOop              _name;                   // class name
  94   int                    _num_loaders;
  95   int                    _max_loaders;
  96   oop*                   _loaders;                // initiating loaders
  97 
  98 public:
  99 
 100   klassOop klass() { return (klassOop)literal(); }
 101   klassOop* klass_addr() { return (klassOop*)literal_addr(); }
 102   void set_klass(klassOop k) { set_literal(k); }
 103 
 104   LoaderConstraintEntry* next() {
 105     return (LoaderConstraintEntry*)HashtableEntry::next();
 106   }
 107 
 108   LoaderConstraintEntry** next_addr() {
 109     return (LoaderConstraintEntry**)HashtableEntry::next_addr();
 110   }
 111   void set_next(LoaderConstraintEntry* next) {
 112     HashtableEntry::set_next(next);
 113   }
 114 
 115   symbolOop name() { return _name; }
 116   symbolOop* name_addr() { return &_name; }
 117   void set_name(symbolOop name) { _name = name; }
 118 
 119   int num_loaders() { return _num_loaders; }
 120   void set_num_loaders(int i) { _num_loaders = i; }
 121 
 122   int max_loaders() { return _max_loaders; }
 123   void set_max_loaders(int i) { _max_loaders = i; }
 124 
 125   oop* loaders() { return _loaders; }
 126   void set_loaders(oop* loaders) { _loaders = loaders; }
 127 
 128   oop loader(int i) { return _loaders[i]; }
 129   oop* loader_addr(int i) { return &_loaders[i]; }
 130   void set_loader(int i, oop p) { _loaders[i] = p; }
 131 
 132 };