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 } 104 105 /* 106 * Declare a class (which should be defined in another file. 107 */ 108 #define DECLARE_CLASS(name) extern struct kobj_class name 109 110 /* 111 * Define a class with no base classes (api backward-compatible. with 112 * FreeBSD-5.1 and earlier). 113 */ 114 #define DEFINE_CLASS(name, methods, size) \ 115 DEFINE_CLASS_0(name, name ## _class, methods, size) 116 117 /* 118 * Define a class with no base classes. Use like this: 119 * 120 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); 121 */ 122 #define DEFINE_CLASS_0(name, classvar, methods, size) \ 123 \ 124 struct kobj_class classvar = { \ 125 #name, methods, size, NULL, 0, NULL \ 126 } 127 128 /* 129 * Define a class with no base classes using the named structure 130 * as an extension of the kobj_class structure. 131 */ 132 #define DEFINE_CLASS_EXT(name, classvar, methods, size, extname) \ 133 \ 134 struct extname classvar = { \ 135 #name, methods, size, NULL, 0, NULL \ 136 } 137 138 /* 139 * Define a class inheriting a single base class. Use like this: 140 * 141 * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc), 142 * bar); 143 */ 144 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 145 base1) \ 146 \ 147 static kobj_class_t name ## _baseclasses[] = { \ 148 &base1, 0 \ 149 }; \ 150 struct kobj_class classvar = { \ 151 #name, methods, size, name ## _baseclasses \ 152 } 153 154 /* 155 * Define a class inheriting two base classes. Use like this: 156 * 157 * DEFINE_CLASS2(foo, foo_class, foo_methods, sizeof(foo_softc), 158 * bar, baz); 159 */ 160 #define DEFINE_CLASS_2(name, methods, size, \ 161 base1, base2) \ 162 \ 163 static kobj_class_t name ## _baseclasses[] = { \ 164 &base1, \ 165 &base2, 0 \ 166 }; \ 167 struct kobj_class name ## _class = { \ 168 #name, methods, size, name ## _baseclasses \ 169 } 170 171 /* 172 * Define a class inheriting three base classes. Use like this: 173 * 174 * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc), 175 * bar, baz, foobar); 176 */ 177 #define DEFINE_CLASS_3(name, methods, size, \ 178 base1, base2, base3) \ 179 \ 180 static kobj_class_t name ## _baseclasses[] = { \ 181 &base1, \ 182 &base2, \ 183 &base3, 0 \ 184 }; \ 185 struct kobj_class name ## _class = { \ 186 #name, methods, size, name ## _baseclasses \ 187 } 188 189 #ifdef _KERNEL 190 191 /* 192 * Compile class for the first instance and add a reference. 193 */ 194 void kobj_class_instantiate(kobj_class_t cls); 195 196 /* 197 * Remove a reference and free method table with the last instance. 198 */ 199 void kobj_class_uninstantiate(kobj_class_t cls); 200 201 /* 202 * Allocate memory for and initialise a new object. 203 */ 204 kobj_t kobj_create(kobj_class_t cls, 205 struct malloc_type *mtype, 206 int mflags); 207 208 /* 209 * Initialise a pre-allocated object. 210 */ 211 void kobj_init(kobj_t obj, kobj_class_t cls); 212 213 /* 214 * Delete an object. If mtype is non-zero, free the memory. 215 */ 216 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 217 218 /* 219 * Lookup the method in the cache and if it isn't there look it up the 220 * slow way. 221 * 222 * We do the cache inside kobj_lookup_method() now, we don't try to 223 * expand it because it's really silly. These lookups are not in the 224 * critical path. 225 */ 226 227 #define KOBJOPLOOKUP(OPS,OP) do { \ 228 _m = kobj_lookup_method_cache(OPS->cls, &OPS->cache[0], \ 229 &OP##_##desc); \ 230 } while(0) 231 232 kobj_method_t *kobj_lookup_method(kobj_class_t cls, 233 kobj_method_t **cep, 234 kobjop_desc_t desc); 235 236 kobjop_t kobj_lookup_method_cache(kobj_class_t cls, 237 kobj_method_t **cep, 238 kobjop_desc_t desc); 239 240 /* 241 * Default method implementation. Returns ENXIO. 242 */ 243 int kobj_error_method(void); 244 245 #endif /* _KERNEL */ 246 247 #endif /* !_SYS_KOBJ_H_ */ 248