1 /* src/vm/classcache.h - loaded class cache and loading constraints
3 Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
4 C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
5 E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
6 J. Wenninger, Institut f. Computersprachen - TU Wien
8 This file is part of CACAO.
10 This program is free software; you can redistribute it and/or
11 modify it under the terms of the GNU General Public License as
12 published by the Free Software Foundation; either version 2, or (at
13 your option) any later version.
15 This program is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
25 Contact: cacao@cacaojvm.org
27 Authors: Edwin Steiner
31 $Id: classcache.h 4945 2006-05-23 19:52:47Z motse $
42 #include <stdio.h> /* for FILE */
44 #include "vm/hashtable.h"
45 #include "vm/references.h"
48 /* forward declarations *******************************************************/
50 typedef struct classcache_name_entry classcache_name_entry;
51 typedef struct classcache_class_entry classcache_class_entry;
52 typedef struct classcache_loader_entry classcache_loader_entry;
54 typedef java_objectheader classloader;
56 /* global variables ***********************************************************/
58 extern hashtable hashtable_classcache;
60 #if defined(ENABLE_JVMTI)
61 #if defined(ENABLE_THREADS)
62 # define CLASSCACHE_LOCK() builtin_monitorenter(lock_hashtable_classcache)
63 # define CLASSCACHE_UNLOCK() builtin_monitorexit(lock_hashtable_classcache)
65 # define CLASSCACHE_LOCK()
66 # define CLASSCACHE_UNLOCK()
69 extern java_objectheader *lock_hashtable_classcache;
72 /* structs ********************************************************************/
74 /*----------------------------------------------------------------------------*/
75 /* The Loaded Class Cache */
77 /* The loaded class cache is implemented as a two-level data structure. */
79 /* The first level is a hash table indexed by class names. For each class */
80 /* name in the cache there is a classcache_name_entry, which collects all */
81 /* information about classes with this class name. */
83 /* Second level: For each classcache_name_entry there is a list of */
84 /* classcache_class_entry:s representing the possible different resolutions */
85 /* of the class name. */
87 /* A classcache_class_entry records the following: */
89 /* - the loaded class object, if this entry has been resolved, otherwise NULL */
90 /* - the list of initiating loaders which have resolved the class name to */
91 /* this class object */
92 /* - the list of initiating loaders which are constrained to resolve this */
93 /* class name to this class object in the future */
95 /* The classcache_class_entry:s approximate the equivalence classes created */
96 /* by the loading constraints and (XXX?) the equivalence of loaded classes. */
98 /* When a loading constraint (loaderA,loaderB,NAME) is added, then the */
99 /* classcache_class_entry:s for NAME containing loaderA and loaderB resp. */
100 /* must be merged into one entry. If this is impossible, because the entries */
101 /* have already been resolved to different class objects, then the constraint */
102 /* is violated and an expception must be thrown. */
103 /*----------------------------------------------------------------------------*/
106 /* classcache_name_entry
108 * For each classname a classcache_name_entry struct is created.
111 struct classcache_name_entry
113 utf *name; /* class name */
114 classcache_name_entry *hashlink; /* link for external chaining */
115 classcache_class_entry *classes; /* equivalence classes for this name*/
118 struct classcache_class_entry
120 classinfo *classobj; /* the loaded class object, or NULL */
121 classcache_loader_entry *loaders;
122 classcache_loader_entry *constraints;
123 classcache_class_entry *next; /* next class entry for same name */
126 struct classcache_loader_entry
128 classloader *loader; /* class loader object */
129 classcache_loader_entry *next; /* next loader entry in the list */
133 /* function prototypes ********************************************************/
135 /* initialize the loaded class cache */
136 bool classcache_init(void);
137 void classcache_free(void);
139 classinfo * classcache_lookup(classloader *initloader,utf *classname);
140 classinfo * classcache_lookup_defined(classloader *defloader,utf *classname);
141 classinfo * classcache_lookup_defined_or_initiated(classloader *loader,utf *classname);
143 bool classcache_store_unique(classinfo *cls);
144 classinfo * classcache_store(classloader *initloader,classinfo *cls,bool mayfree);
145 classinfo * classcache_store_defined(classinfo *cls);
147 #if defined(ENABLE_VERIFIER)
148 bool classcache_add_constraint(classloader *a,classloader *b,utf *classname);
149 bool classcache_add_constraints_for_params(classloader *a,classloader *b,
154 void classcache_debug_dump(FILE *file,utf *only);
157 #endif /* _CLASSCACHE_H */
160 * These are local overrides for various environment variables in Emacs.
161 * Please do not remove this and leave it at the end of the file, where
162 * Emacs will automagically detect them.
163 * ---------------------------------------------------------------------
166 * indent-tabs-mode: t
170 * vim:noexpandtab:sw=4:ts=4: