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 * $DragonFly: src/sys/sys/kobj.h,v 1.10 2006/05/20 02:42:13 dillon Exp $ 28 */ 29 30 #ifndef _SYS_KOBJ_H_ 31 #define _SYS_KOBJ_H_ 32 33 #ifndef _SYS_TYPES_H_ 34 #include <sys/types.h> 35 #endif 36 37 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES) 38 #error "This file should not be included by userland programs." 39 #endif 40 41 /* 42 * Forward declarations 43 */ 44 typedef struct kobj *kobj_t; 45 typedef struct kobj_class *kobj_class_t; 46 typedef struct kobj_method kobj_method_t; 47 typedef int (*kobjop_t)(void); 48 typedef struct kobj_ops *kobj_ops_t; 49 typedef struct kobjop_desc *kobjop_desc_t; 50 struct malloc_type; 51 52 struct kobj_method { 53 kobjop_desc_t desc; 54 kobjop_t func; 55 }; 56 57 /* 58 * A class is simply a method table and a sizeof value. When the first 59 * instance of the class is created, the method table will be compiled 60 * into a form more suited to efficient method dispatch. This compiled 61 * method table is always the first field of the object. 62 */ 63 #define KOBJ_CLASS_FIELDS \ 64 const char *name; /* class name */ \ 65 kobj_method_t *methods; /* method table */ \ 66 size_t size; /* object size */ \ 67 kobj_class_t *baseclasses; /* base classes */ \ 68 u_int refs; /* reference count */ \ 69 kobj_ops_t ops /* compiled method table */ 70 71 struct kobj_class { 72 KOBJ_CLASS_FIELDS; 73 }; 74 75 /* 76 * Implementation of kobj. 77 */ 78 #define KOBJ_FIELDS \ 79 kobj_ops_t ops 80 81 struct kobj { 82 KOBJ_FIELDS; 83 }; 84 85 /* 86 * The ops table is used as a cache of results from kobj_lookup_method(). 87 */ 88 89 #define KOBJ_CACHE_SIZE 256 90 91 struct kobj_ops { 92 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 93 kobj_class_t cls; 94 }; 95 96 struct kobjop_desc { 97 unsigned int id; /* unique ID */ 98 kobj_method_t *deflt; /* default implementation */ 99 }; 100 101 /* 102 * Shorthand for constructing method tables. 103 */ 104 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC } 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 inheriting a single base class. Use like this: 131 * 132 * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc), 133 * bar); 134 */ 135 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 136 base1) \ 137 \ 138 static kobj_class_t name ## _baseclasses[] = { \ 139 &base1, 0 \ 140 }; \ 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_CLASS2(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, 0 \ 157 }; \ 158 struct kobj_class name ## _class = { \ 159 #name, methods, size, name ## _baseclasses \ 160 } 161 162 /* 163 * Define a class inheriting three base classes. Use like this: 164 * 165 * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc), 166 * bar, baz, foobar); 167 */ 168 #define DEFINE_CLASS_3(name, methods, size, \ 169 base1, base2, base3) \ 170 \ 171 static kobj_class_t name ## _baseclasses[] = { \ 172 &base1, \ 173 &base2, \ 174 &base3, 0 \ 175 }; \ 176 struct kobj_class name ## _class = { \ 177 #name, methods, size, name ## _baseclasses \ 178 } 179 180 #ifdef _KERNEL 181 182 /* 183 * Compile class for the first instance and add a reference. 184 */ 185 void kobj_class_instantiate(kobj_class_t cls); 186 187 /* 188 * Remove a reference and free method table with the last instance. 189 */ 190 void kobj_class_uninstantiate(kobj_class_t cls); 191 192 /* 193 * Allocate memory for and initialise a new object. 194 */ 195 kobj_t kobj_create(kobj_class_t cls, 196 struct malloc_type *mtype, 197 int mflags); 198 199 /* 200 * Initialise a pre-allocated object. 201 */ 202 void kobj_init(kobj_t obj, kobj_class_t cls); 203 204 /* 205 * Delete an object. If mtype is non-zero, free the memory. 206 */ 207 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 208 209 /* 210 * Maintain stats on hits/misses in lookup caches. 211 */ 212 #ifdef KOBJ_STATS 213 extern u_int kobj_lookup_hits; 214 extern u_int kobj_lookup_misses; 215 #endif 216 217 /* 218 * Lookup the method in the cache and if it isn't there look it up the 219 * slow way. 220 */ 221 #ifdef KOBJ_STATS 222 #define KOBJOPLOOKUP(OPS,OP) do { \ 223 kobjop_desc_t _desc = &OP##_##desc; \ 224 kobj_method_t **_cep = \ 225 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 226 kobj_method_t *_ce = *_cep; \ 227 kobj_lookup_hits++; /* assume hit */ \ 228 if (_ce->desc != _desc) \ 229 _ce = kobj_lookup_method(OPS->cls, \ 230 _cep, _desc); \ 231 _m = _ce->func; \ 232 } while(0) 233 #else 234 #define KOBJOPLOOKUP(OPS,OP) do { \ 235 kobjop_desc_t _desc = &OP##_##desc; \ 236 kobj_method_t **_cep = \ 237 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 238 kobj_method_t *_ce = *_cep; \ 239 if (_ce->desc != _desc) \ 240 _ce = kobj_lookup_method(OPS->cls, \ 241 _cep, _desc); \ 242 _m = _ce->func; \ 243 } while(0) 244 #endif 245 246 kobj_method_t *kobj_lookup_method(kobj_class_t cls, 247 kobj_method_t **cep, 248 kobjop_desc_t desc); 249 250 /* 251 * Default method implementation. Returns ENXIO. 252 */ 253 int kobj_error_method(void); 254 255 #endif /* _KERNEL */ 256 257 #endif /* !_SYS_KOBJ_H_ */ 258