2 * Copyright (c) 2000,2003 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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12 * documentation and/or other materials provided with the distribution.
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21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * Forward declarations
35 typedef struct kobj *kobj_t;
36 typedef struct kobj_class *kobj_class_t;
37 typedef struct kobj_method kobj_method_t;
38 typedef int (*kobjop_t)(void);
39 typedef struct kobj_ops *kobj_ops_t;
40 typedef struct kobjop_desc *kobjop_desc_t;
49 * A class is simply a method table and a sizeof value. When the first
50 * instance of the class is created, the method table will be compiled
51 * into a form more suited to efficient method dispatch. This compiled
52 * method table is always the first field of the object.
54 #define KOBJ_CLASS_FIELDS \
55 const char *name; /* class name */ \
56 kobj_method_t *methods; /* method table */ \
57 size_t size; /* object size */ \
58 kobj_class_t *baseclasses; /* base classes */ \
59 u_int refs; /* reference count */ \
60 kobj_ops_t ops /* compiled method table */
67 * Implementation of kobj.
77 * The ops table is used as a cache of results from kobj_lookup_method().
80 #define KOBJ_CACHE_SIZE 256
83 kobj_method_t *cache[KOBJ_CACHE_SIZE];
88 unsigned int id; /* unique ID */
89 kobj_method_t *deflt; /* default implementation */
93 * Shorthand for constructing method tables.
94 * The ternary operator is (ab)used to provoke a warning when FUNC
95 * has a signature that is not compatible with kobj method signature.
97 #define KOBJMETHOD(NAME, FUNC) \
98 { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) }
103 #define KOBJMETHOD_END { NULL, NULL }
106 * Declare a class (which should be defined in another file.
108 #define DECLARE_CLASS(name) extern struct kobj_class name
111 * Define a class with no base classes (api backward-compatible. with
112 * FreeBSD-5.1 and earlier).
114 #define DEFINE_CLASS(name, methods, size) \
115 DEFINE_CLASS_0(name, name ## _class, methods, size)
118 * Define a class with no base classes. Use like this:
120 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc));
122 #define DEFINE_CLASS_0(name, classvar, methods, size) \
124 struct kobj_class classvar = { \
125 #name, methods, size, NULL \
129 * Define a class inheriting a single base class. Use like this:
131 * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc),
134 #define DEFINE_CLASS_1(name, classvar, methods, size, \
137 static kobj_class_t name ## _baseclasses[] = \
139 struct kobj_class classvar = { \
140 #name, methods, size, name ## _baseclasses \
144 * Define a class inheriting two base classes. Use like this:
146 * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc),
149 #define DEFINE_CLASS_2(name, methods, size, \
152 static kobj_class_t name ## _baseclasses[] = \
155 struct kobj_class name ## _class = { \
156 #name, methods, size, name ## _baseclasses \
160 * Define a class inheriting three base classes. Use like this:
162 * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc),
165 #define DEFINE_CLASS_3(name, methods, size, \
166 base1, base2, base3) \
168 static kobj_class_t name ## _baseclasses[] = \
172 struct kobj_class name ## _class = { \
173 #name, methods, size, name ## _baseclasses \
178 * Compile the method table in a class.
180 void kobj_class_compile(kobj_class_t cls);
183 * Compile the method table, with the caller providing the space for
184 * the ops table.(for use before malloc is initialised).
186 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops);
189 * Free the compiled method table in a class.
191 void kobj_class_free(kobj_class_t cls);
194 * Allocate memory for and initialise a new object.
196 kobj_t kobj_create(kobj_class_t cls,
197 struct malloc_type *mtype,
201 * Initialise a pre-allocated object.
203 void kobj_init(kobj_t obj, kobj_class_t cls);
204 void kobj_init_static(kobj_t obj, kobj_class_t cls);
207 * Delete an object. If mtype is non-zero, free the memory.
209 void kobj_delete(kobj_t obj, struct malloc_type *mtype);
212 * Maintain stats on hits/misses in lookup caches.
215 extern u_int kobj_lookup_hits;
216 extern u_int kobj_lookup_misses;
220 * Lookup the method in the cache and if it isn't there look it up the
224 #define KOBJOPLOOKUP(OPS,OP) do { \
225 kobjop_desc_t _desc = &OP##_##desc; \
226 kobj_method_t **_cep = \
227 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
228 kobj_method_t *_ce = *_cep; \
229 kobj_lookup_hits++; /* assume hit */ \
230 if (_ce->desc != _desc) \
231 _ce = kobj_lookup_method(OPS->cls, \
236 #define KOBJOPLOOKUP(OPS,OP) do { \
237 kobjop_desc_t _desc = &OP##_##desc; \
238 kobj_method_t **_cep = \
239 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
240 kobj_method_t *_ce = *_cep; \
241 if (_ce->desc != _desc) \
242 _ce = kobj_lookup_method(OPS->cls, \
248 kobj_method_t* kobj_lookup_method(kobj_class_t cls,
254 * Default method implementation. Returns ENXIO.
256 int kobj_error_method(void);
258 #endif /* !_SYS_KOBJ_H_ */