1 /*- 2 * Copyright (c) 2000 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: src/sys/sys/kobj.h,v 1.8 2003/09/22 21:32:49 peter Exp $ 27 */ 28 29 #ifndef _SYS_KOBJ_H_ 30 #define _SYS_KOBJ_H_ 31 32 #ifndef _SYS_TYPES_H_ 33 #include <sys/types.h> 34 #endif 35 36 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES) 37 #error "This file should not be included by userland programs." 38 #endif 39 40 /* 41 * Forward declarations 42 */ 43 typedef struct kobj *kobj_t; 44 typedef struct kobj_class *kobj_class_t; 45 typedef const struct kobj_method kobj_method_t; 46 typedef int (*kobjop_t)(void); 47 typedef struct kobj_ops *kobj_ops_t; 48 typedef struct kobjop_desc *kobjop_desc_t; 49 struct malloc_type; 50 51 struct kobj_method { 52 kobjop_desc_t desc; 53 kobjop_t func; 54 }; 55 56 /* 57 * A class is simply a method table and a sizeof value. When the first 58 * instance of the class is created, the method table will be compiled 59 * into a form more suited to efficient method dispatch. This compiled 60 * method table is always the first field of the object. 61 */ 62 #define KOBJ_CLASS_FIELDS \ 63 const char *name; /* class name */ \ 64 kobj_method_t *methods; /* method table */ \ 65 size_t size; /* object size */ \ 66 kobj_class_t *baseclasses; /* base classes */ \ 67 u_int refs; /* reference count */ \ 68 kobj_ops_t ops /* compiled method table */ 69 70 struct kobj_class { 71 KOBJ_CLASS_FIELDS; 72 }; 73 74 /* 75 * Implementation of kobj. 76 */ 77 #define KOBJ_FIELDS \ 78 kobj_ops_t ops 79 80 struct kobj { 81 KOBJ_FIELDS; 82 }; 83 84 /* 85 * The ops table is used as a cache of results from kobj_lookup_method(). 86 */ 87 88 #define KOBJ_CACHE_SIZE 256 89 90 struct kobj_ops { 91 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 92 kobj_class_t cls; 93 }; 94 95 struct kobjop_desc { 96 unsigned int id; /* unique ID */ 97 kobj_method_t deflt; /* default implementation */ 98 }; 99 100 /* 101 * Shorthand for constructing method tables. 102 */ 103 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC } 104 #define KOBJMETHOD_END { NULL, NULL } 105 106 /* 107 * Declare a class (which should be defined in another file. 108 */ 109 #define DECLARE_CLASS(name) extern struct kobj_class name 110 111 /* 112 * Define a class with no base classes (api backward-compatible. with 113 * FreeBSD-5.1 and earlier). 114 */ 115 #define DEFINE_CLASS(name, methods, size) \ 116 DEFINE_CLASS_0(name, name ## _class, methods, size) 117 118 /* 119 * Define a class with no base classes. Use like this: 120 * 121 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); 122 */ 123 #define DEFINE_CLASS_0(name, classvar, methods, size) \ 124 \ 125 struct kobj_class classvar = { \ 126 #name, methods, size, NULL, 0, NULL \ 127 } 128 129 /* 130 * Define a class with no base classes using the named structure 131 * as an extension of the kobj_class structure. 132 */ 133 #define DEFINE_CLASS_EXT(name, classvar, methods, size, extname) \ 134 \ 135 struct extname classvar = { \ 136 #name, methods, size, NULL, 0, NULL \ 137 } 138 139 /* 140 * Define a class inheriting a single base class. Use like this: 141 * 142 * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc), 143 * bar); 144 */ 145 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 146 base1) \ 147 \ 148 static kobj_class_t name ## _baseclasses[] = { \ 149 &base1, 0 \ 150 }; \ 151 struct kobj_class classvar = { \ 152 #name, methods, size, name ## _baseclasses \ 153 } 154 155 /* 156 * Define a class inheriting two base classes. Use like this: 157 * 158 * DEFINE_CLASS2(foo, foo_class, foo_methods, sizeof(foo_softc), 159 * bar, baz); 160 */ 161 #define DEFINE_CLASS_2(name, methods, size, \ 162 base1, base2) \ 163 \ 164 static kobj_class_t name ## _baseclasses[] = { \ 165 &base1, \ 166 &base2, 0 \ 167 }; \ 168 struct kobj_class name ## _class = { \ 169 #name, methods, size, name ## _baseclasses \ 170 } 171 172 /* 173 * Define a class inheriting three base classes. Use like this: 174 * 175 * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc), 176 * bar, baz, foobar); 177 */ 178 #define DEFINE_CLASS_3(name, methods, size, \ 179 base1, base2, base3) \ 180 \ 181 static kobj_class_t name ## _baseclasses[] = { \ 182 &base1, \ 183 &base2, \ 184 &base3, 0 \ 185 }; \ 186 struct kobj_class name ## _class = { \ 187 #name, methods, size, name ## _baseclasses \ 188 } 189 190 #ifdef _KERNEL 191 192 /* 193 * Compile class for the first instance and add a reference. 194 */ 195 void kobj_class_instantiate(kobj_class_t cls); 196 197 /* 198 * Remove a reference and free method table with the last instance. 199 */ 200 void kobj_class_uninstantiate(kobj_class_t cls); 201 202 /* 203 * Allocate memory for and initialise a new object. 204 */ 205 kobj_t kobj_create(kobj_class_t cls, 206 struct malloc_type *mtype, 207 int mflags); 208 209 /* 210 * Initialise a pre-allocated object. 211 */ 212 void kobj_init(kobj_t obj, kobj_class_t cls); 213 214 /* 215 * Delete an object. If mtype is non-zero, free the memory. 216 */ 217 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 218 219 /* 220 * Lookup the method in the cache and if it isn't there look it up the 221 * slow way. 222 * 223 * We do the cache inside kobj_lookup_method() now, we don't try to 224 * expand it because it's really silly. These lookups are not in the 225 * critical path. 226 */ 227 228 #define KOBJOPLOOKUP(OPS,OP) do { \ 229 _m = kobj_lookup_method_cache(OPS->cls, &OPS->cache[0], \ 230 &OP##_##desc); \ 231 } while(0) 232 233 kobj_method_t *kobj_lookup_method(kobj_class_t cls, 234 kobj_method_t **cep, 235 kobjop_desc_t desc); 236 237 kobjop_t kobj_lookup_method_cache(kobj_class_t cls, 238 kobj_method_t **cep, 239 kobjop_desc_t desc); 240 241 /* 242 * Default method implementation. Returns ENXIO. 243 */ 244 int kobj_error_method(void); 245 246 #endif /* _KERNEL */ 247 248 #endif /* !_SYS_KOBJ_H_ */ 249