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/placeholders.hpp"

    29 #include "utilities/hashtable.hpp"

    30 

    31 class ClassLoaderData;

    32 class LoaderConstraintEntry;

    33 class Symbol;

    34 

    35 class LoaderConstraintTable : public Hashtable<InstanceKlass*, mtClass> {

    36 

    37 private:

    38   LoaderConstraintEntry** find_loader_constraint(Symbol* name,

    39                                                  Handle loader);

    40 

    41 public:

    42 

    43   LoaderConstraintTable(int table_size);

    44 

    45   LoaderConstraintEntry* new_entry(unsigned int hash, Symbol* name,

    46                                    InstanceKlass* klass, int num_loaders,

    47                                    int max_loaders);

    48   void free_entry(LoaderConstraintEntry *entry);

    49 

    50   LoaderConstraintEntry* bucket(int i) const {

    51     return (LoaderConstraintEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);

    52   }

    53 

    54   LoaderConstraintEntry** bucket_addr(int i) {

    55     return (LoaderConstraintEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);

    56   }

    57 

    58   // Check class loader constraints

    59   bool add_entry(Symbol* name, InstanceKlass* klass1, Handle loader1,

    60                                     InstanceKlass* klass2, Handle loader2);

    61 

    62   // Note:  The main entry point for this module is via SystemDictionary.

    63   // SystemDictionary::check_signature_loaders(Symbol* signature,

    64   //                                           Handle loader1, Handle loader2,

    65   //                                           bool is_method, TRAPS)

    66 

    67   InstanceKlass* find_constrained_klass(Symbol* name, Handle loader);

    68 

    69   // Class loader constraints

    70 

    71   void ensure_loader_constraint_capacity(LoaderConstraintEntry *p, int nfree);

    72   void extend_loader_constraint(LoaderConstraintEntry* p, Handle loader,

    73                                 InstanceKlass* klass);

    74   void merge_loader_constraints(LoaderConstraintEntry** pp1,

    75                                 LoaderConstraintEntry** pp2, InstanceKlass* klass);

    76 

    77   bool check_or_update(InstanceKlass* k, Handle loader, Symbol* name);

    78 

    79   void purge_loader_constraints();

    80 

    81   void verify(PlaceholderTable* placeholders);

    82   void print_on(outputStream* st) const;

    83 };

    84 

    85 class LoaderConstraintEntry : public HashtableEntry<InstanceKlass*, mtClass> {

    86 private:

    87   Symbol*                _name;                   // class name

    88   int                    _num_loaders;

    89   int                    _max_loaders;

    90   // Loader constraints enforce correct linking behavior.

    91   // Thus, it really operates on ClassLoaderData which represents linking domain,

    92   // not class loaders.

    93   ClassLoaderData**              _loaders;                // initiating loaders

    94 

    95 public:

    96 

    97   InstanceKlass* klass() { return literal(); }

    98   InstanceKlass** klass_addr() { return literal_addr(); }

    99   void set_klass(InstanceKlass* k) { set_literal(k); }

   100 

   101   LoaderConstraintEntry* next() {

   102     return (LoaderConstraintEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();

   103   }

   104 

   105   LoaderConstraintEntry** next_addr() {

   106     return (LoaderConstraintEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();

   107   }

   108   void set_next(LoaderConstraintEntry* next) {

   109     HashtableEntry<InstanceKlass*, mtClass>::set_next(next);

   110   }

   111 

   112   Symbol* name() { return _name; }

   113   void set_name(Symbol* name) {

   114     _name = name;

   115     if (name != NULL) name->increment_refcount();

   116   }

   117 

   118   int num_loaders() { return _num_loaders; }

   119   void set_num_loaders(int i) { _num_loaders = i; }

   120 

   121   int max_loaders() { return _max_loaders; }

   122   void set_max_loaders(int i) { _max_loaders = i; }

   123 

   124   ClassLoaderData** loaders() { return _loaders; }

   125   void set_loaders(ClassLoaderData** loaders) { _loaders = loaders; }

   126 

   127   ClassLoaderData* loader_data(int i) { return _loaders[i]; }

   128   void set_loader_data(int i, ClassLoaderData* p) { _loaders[i] = p; }

   129   // convenience

   130   void set_loader(int i, oop p);

   131 };

   132 

   133 #endif // SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP