FreeBSD/Linux Kernel Cross Reference
sys/sys/kobj.h
1 /*-
2 * Copyright (c) 2000,2003 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: releng/7.3/sys/sys/kobj.h 190279 2009-03-22 20:52:43Z marius $
27 */
28
29 #ifndef _SYS_KOBJ_H_
30 #define _SYS_KOBJ_H_
31
32 /*
33 * Forward declarations
34 */
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;
41 struct malloc_type;
42
43 struct kobj_method {
44 kobjop_desc_t desc;
45 kobjop_t func;
46 };
47
48 /*
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.
53 */
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 */
61
62 struct kobj_class {
63 KOBJ_CLASS_FIELDS;
64 };
65
66 /*
67 * Implementation of kobj.
68 */
69 #define KOBJ_FIELDS \
70 kobj_ops_t ops
71
72 struct kobj {
73 KOBJ_FIELDS;
74 };
75
76 /*
77 * The ops table is used as a cache of results from kobj_lookup_method().
78 */
79
80 #define KOBJ_CACHE_SIZE 256
81
82 struct kobj_ops {
83 kobj_method_t *cache[KOBJ_CACHE_SIZE];
84 kobj_class_t cls;
85 };
86
87 struct kobjop_desc {
88 unsigned int id; /* unique ID */
89 kobj_method_t *deflt; /* default implementation */
90 };
91
92 /*
93 * Shorthand for constructing method tables.
94 */
95 #if 1
96 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC }
97 #else /* notyet */
98 #define KOBJMETHOD(NAME, FUNC) \
99 { &NAME##_desc, (kobjop_t) (FUNC != (NAME##_t *)NULL ? FUNC : NULL) }
100 #endif
101
102 /*
103 *
104 */
105 #define KOBJMETHOD_END { NULL, NULL }
106
107 /*
108 * Declare a class (which should be defined in another file.
109 */
110 #define DECLARE_CLASS(name) extern struct kobj_class name
111
112 /*
113 * Define a class with no base classes (api backward-compatible. with
114 * FreeBSD-5.1 and earlier).
115 */
116 #define DEFINE_CLASS(name, methods, size) \
117 DEFINE_CLASS_0(name, name ## _class, methods, size)
118
119 /*
120 * Define a class with no base classes. Use like this:
121 *
122 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc));
123 */
124 #define DEFINE_CLASS_0(name, classvar, methods, size) \
125 \
126 struct kobj_class classvar = { \
127 #name, methods, size, NULL \
128 }
129
130 /*
131 * Define a class inheriting a single base class. Use like this:
132 *
133 * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc),
134 * bar);
135 */
136 #define DEFINE_CLASS_1(name, classvar, methods, size, \
137 base1) \
138 \
139 static kobj_class_t name ## _baseclasses[] = \
140 { &base1, NULL }; \
141 struct kobj_class classvar = { \
142 #name, methods, size, name ## _baseclasses \
143 }
144
145 /*
146 * Define a class inheriting two base classes. Use like this:
147 *
148 * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc),
149 * bar, baz);
150 */
151 #define DEFINE_CLASS_2(name, methods, size, \
152 base1, base2) \
153 \
154 static kobj_class_t name ## _baseclasses[] = \
155 { &base1, \
156 &base2, NULL }; \
157 struct kobj_class name ## _class = { \
158 #name, methods, size, name ## _baseclasses \
159 }
160
161 /*
162 * Define a class inheriting three base classes. Use like this:
163 *
164 * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc),
165 * bar, baz, foobar);
166 */
167 #define DEFINE_CLASS_3(name, methods, size, \
168 base1, base2, base3) \
169 \
170 static kobj_class_t name ## _baseclasses[] = \
171 { &base1, \
172 &base2, \
173 &base3, NULL }; \
174 struct kobj_class name ## _class = { \
175 #name, methods, size, name ## _baseclasses \
176 }
177
178
179 /*
180 * Compile the method table in a class.
181 */
182 void kobj_class_compile(kobj_class_t cls);
183
184 /*
185 * Compile the method table, with the caller providing the space for
186 * the ops table.(for use before malloc is initialised).
187 */
188 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops);
189
190 /*
191 * Free the compiled method table in a class.
192 */
193 void kobj_class_free(kobj_class_t cls);
194
195 /*
196 * Allocate memory for and initialise a new object.
197 */
198 kobj_t kobj_create(kobj_class_t cls,
199 struct malloc_type *mtype,
200 int mflags);
201
202 /*
203 * Initialise a pre-allocated object.
204 */
205 void kobj_init(kobj_t obj, kobj_class_t cls);
206
207 /*
208 * Delete an object. If mtype is non-zero, free the memory.
209 */
210 void kobj_delete(kobj_t obj, struct malloc_type *mtype);
211
212 /*
213 * Maintain stats on hits/misses in lookup caches.
214 */
215 #ifdef KOBJ_STATS
216 extern u_int kobj_lookup_hits;
217 extern u_int kobj_lookup_misses;
218 #endif
219
220 /*
221 * Lookup the method in the cache and if it isn't there look it up the
222 * slow way.
223 */
224 #ifdef KOBJ_STATS
225 #define KOBJOPLOOKUP(OPS,OP) do { \
226 kobjop_desc_t _desc = &OP##_##desc; \
227 kobj_method_t **_cep = \
228 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
229 kobj_method_t *_ce = *_cep; \
230 kobj_lookup_hits++; /* assume hit */ \
231 if (_ce->desc != _desc) \
232 _ce = kobj_lookup_method(OPS->cls, \
233 _cep, _desc); \
234 _m = _ce->func; \
235 } while(0)
236 #else
237 #define KOBJOPLOOKUP(OPS,OP) do { \
238 kobjop_desc_t _desc = &OP##_##desc; \
239 kobj_method_t **_cep = \
240 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
241 kobj_method_t *_ce = *_cep; \
242 if (_ce->desc != _desc) \
243 _ce = kobj_lookup_method(OPS->cls, \
244 _cep, _desc); \
245 _m = _ce->func; \
246 } while(0)
247 #endif
248
249 kobj_method_t* kobj_lookup_method(kobj_class_t cls,
250 kobj_method_t **cep,
251 kobjop_desc_t desc);
252
253
254 /*
255 * Default method implementation. Returns ENXIO.
256 */
257 int kobj_error_method(void);
258
259 /*
260 * Machine-dependent initialisation call for boot-time kobj clients
261 */
262 void kobj_machdep_init(void);
263
264 #endif /* !_SYS_KOBJ_H_ */
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