1 /* src/vm/classcache.h - loaded class cache and loading constraints
3 Copyright (C) 1996-2005, 2006, 2007, 2008
4 CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
6 This file is part of CACAO.
8 This program is free software; you can redistribute it and/or
9 modify it under the terms of the GNU General Public License as
10 published by the Free Software Foundation; either version 2, or (at
11 your option) any later version.
13 This program is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
37 #include <stdio.h> /* for FILE */
39 #if defined(ENABLE_JVMTI)
40 # include "native/jni.h"
43 #include "toolbox/hashtable.h"
46 #include "vm/global.h"
47 #include "vm/loader.h"
48 #include "vm/references.h"
51 /* forward declarations *******************************************************/
53 typedef struct classcache_name_entry classcache_name_entry;
54 typedef struct classcache_class_entry classcache_class_entry;
55 typedef struct classcache_loader_entry classcache_loader_entry;
57 /* global variables ***********************************************************/
59 extern hashtable hashtable_classcache;
62 /* structs ********************************************************************/
64 /*----------------------------------------------------------------------------*/
65 /* The Loaded Class Cache */
67 /* The loaded class cache is implemented as a two-level data structure. */
69 /* The first level is a hash table indexed by class names. For each class */
70 /* name in the cache there is a classcache_name_entry, which collects all */
71 /* information about classes with this class name. */
73 /* Second level: For each classcache_name_entry there is a list of */
74 /* classcache_class_entry:s representing the possible different resolutions */
75 /* of the class name. */
77 /* A classcache_class_entry records the following: */
79 /* - the loaded class object, if this entry has been resolved, otherwise NULL */
80 /* - the list of initiating loaders which have resolved the class name to */
81 /* this class object */
82 /* - the list of initiating loaders which are constrained to resolve this */
83 /* class name to this class object in the future */
85 /* The classcache_class_entry:s approximate the equivalence classes created */
86 /* by the loading constraints and the equivalence of loaded classes. */
88 /* When a loading constraint (loaderA,loaderB,NAME) is added, then the */
89 /* classcache_class_entry:s for NAME containing loaderA and loaderB resp. */
90 /* must be merged into one entry. If this is impossible, because the entries */
91 /* have already been resolved to different class objects, then the constraint */
92 /* is violated and an expception must be thrown. */
93 /*----------------------------------------------------------------------------*/
96 /* classcache_name_entry
98 * For each classname a classcache_name_entry struct is created.
101 struct classcache_name_entry
103 utf *name; /* class name */
104 classcache_name_entry *hashlink; /* link for external chaining */
105 classcache_class_entry *classes; /* equivalence classes for this name*/
108 struct classcache_class_entry
110 classinfo *classobj; /* the loaded class object, or NULL */
111 classcache_loader_entry *loaders;
112 classcache_loader_entry *constraints;
113 classcache_class_entry *next; /* next class entry for same name */
116 struct classcache_loader_entry
118 classloader_t *loader; /* class loader object */
119 classcache_loader_entry *next; /* next loader entry in the list */
123 /* callback function type for classcache_foreach_loaded_class */
125 typedef void (*classcache_foreach_functionptr_t)(classinfo *, void *);
128 /* function prototypes ********************************************************/
130 /* initialize the loaded class cache */
131 bool classcache_init(void);
132 void classcache_free(void);
134 classinfo * classcache_lookup(classloader_t *initloader,utf *classname);
135 classinfo * classcache_lookup_defined(classloader_t *defloader,utf *classname);
136 classinfo * classcache_lookup_defined_or_initiated(classloader_t *loader,utf *classname);
138 bool classcache_store_unique(classinfo *cls);
139 classinfo * classcache_store(classloader_t *initloader,classinfo *cls,bool mayfree);
140 classinfo * classcache_store_defined(classinfo *cls);
142 #if defined(ENABLE_VERIFIER)
143 bool classcache_add_constraint(classloader_t *a,classloader_t *b,utf *classname);
144 bool classcache_add_constraints_for_params(classloader_t *a,classloader_t *b,
148 s4 classcache_get_loaded_class_count(void);
150 void classcache_foreach_loaded_class(classcache_foreach_functionptr_t func,
153 #if defined(ENABLE_JVMTI)
154 void classcache_get_loaded_classes(s4 *class_count_ptr,
155 classinfo ***classes_ptr);
159 void classcache_debug_dump(FILE *file,utf *only);
166 #endif /* _CLASSCACHE_H */
169 * These are local overrides for various environment variables in Emacs.
170 * Please do not remove this and leave it at the end of the file, where
171 * Emacs will automagically detect them.
172 * ---------------------------------------------------------------------
175 * indent-tabs-mode: t
179 * vim:noexpandtab:sw=4:ts=4: