2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000,2003 Doug Rabson
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8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
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14 * documentation and/or other materials provided with the distribution.
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19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Forward declarations
37 typedef struct kobj *kobj_t;
38 typedef struct kobj_class *kobj_class_t;
39 typedef const struct kobj_method kobj_method_t;
40 typedef int (*kobjop_t)(void);
41 typedef struct kobj_ops *kobj_ops_t;
42 typedef struct kobjop_desc *kobjop_desc_t;
51 * A class is simply a method table and a sizeof value. When the first
52 * instance of the class is created, the method table will be compiled
53 * into a form more suited to efficient method dispatch. This compiled
54 * method table is always the first field of the object.
56 #define KOBJ_CLASS_FIELDS \
57 const char *name; /* class name */ \
58 kobj_method_t *methods; /* method table */ \
59 size_t size; /* object size */ \
60 kobj_class_t *baseclasses; /* base classes */ \
61 u_int refs; /* reference count */ \
62 kobj_ops_t ops /* compiled method table */
69 * Implementation of kobj.
79 * The ops table is used as a cache of results from kobj_lookup_method().
82 #define KOBJ_CACHE_SIZE 256
85 kobj_method_t *cache[KOBJ_CACHE_SIZE];
90 unsigned int id; /* unique ID */
91 kobj_method_t deflt; /* default implementation */
95 * Shorthand for constructing method tables.
96 * The ternary operator is (ab)used to provoke a warning when FUNC
97 * has a signature that is not compatible with kobj method signature.
99 #define KOBJMETHOD(NAME, FUNC) \
100 { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) }
105 #define KOBJMETHOD_END { NULL, NULL }
108 * Declare a class (which should be defined in another file.
110 #define DECLARE_CLASS(name) extern struct kobj_class name
113 * Define a class with no base classes (api backward-compatible. with
114 * FreeBSD-5.1 and earlier).
116 #define DEFINE_CLASS(name, methods, size) \
117 DEFINE_CLASS_0(name, name ## _class, methods, size)
120 * Define a class with no base classes. Use like this:
122 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc));
124 #define DEFINE_CLASS_0(name, classvar, methods, size) \
126 struct kobj_class classvar = { \
127 #name, methods, size, NULL \
131 * Define a class inheriting a single base class. Use like this:
133 * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc),
136 #define DEFINE_CLASS_1(name, classvar, methods, size, \
139 static kobj_class_t name ## _baseclasses[] = \
141 struct kobj_class classvar = { \
142 #name, methods, size, name ## _baseclasses \
146 * Define a class inheriting two base classes. Use like this:
148 * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc),
151 #define DEFINE_CLASS_2(name, classvar, methods, size, \
154 static kobj_class_t name ## _baseclasses[] = \
157 struct kobj_class classvar = { \
158 #name, methods, size, name ## _baseclasses \
162 * Define a class inheriting three base classes. Use like this:
164 * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc),
167 #define DEFINE_CLASS_3(name, classvar, methods, size, \
168 base1, base2, base3) \
170 static kobj_class_t name ## _baseclasses[] = \
174 struct kobj_class classvar = { \
175 #name, methods, size, name ## _baseclasses \
180 * Compile the method table in a class.
182 void kobj_class_compile(kobj_class_t cls);
185 * Compile the method table, with the caller providing the space for
186 * the ops table.(for use before malloc is initialised).
188 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops);
191 * Free the compiled method table in a class.
193 void kobj_class_free(kobj_class_t cls);
196 * Allocate memory for and initialise a new object.
198 kobj_t kobj_create(kobj_class_t cls,
199 struct malloc_type *mtype,
203 * Initialise a pre-allocated object.
205 void kobj_init(kobj_t obj, kobj_class_t cls);
206 void kobj_init_static(kobj_t obj, kobj_class_t cls);
209 * Delete an object. If mtype is non-zero, free the memory.
211 void kobj_delete(kobj_t obj, struct malloc_type *mtype);
214 * Maintain stats on hits/misses in lookup caches.
217 extern u_int kobj_lookup_hits;
218 extern u_int kobj_lookup_misses;
222 * Lookup the method in the cache and if it isn't there look it up the
226 #define KOBJOPLOOKUP(OPS,OP) do { \
227 kobjop_desc_t _desc = &OP##_##desc; \
228 kobj_method_t **_cep = \
229 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
230 kobj_method_t *_ce = *_cep; \
231 if (_ce->desc != _desc) { \
232 _ce = kobj_lookup_method(OPS->cls, \
234 kobj_lookup_misses++; \
236 kobj_lookup_hits++; \
240 #define KOBJOPLOOKUP(OPS,OP) do { \
241 kobjop_desc_t _desc = &OP##_##desc; \
242 kobj_method_t **_cep = \
243 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
244 kobj_method_t *_ce = *_cep; \
245 if (_ce->desc != _desc) \
246 _ce = kobj_lookup_method(OPS->cls, \
252 kobj_method_t* kobj_lookup_method(kobj_class_t cls,
258 * Default method implementation. Returns ENXIO.
260 int kobj_error_method(void);
262 #endif /* !_SYS_KOBJ_H_ */