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 1.9 2005/03/08 17:43:33 joerg Exp $ 28 */ 29 30 #ifndef _SYS_KOBJ_H_ 31 #define _SYS_KOBJ_H_ 32 33 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES) 34 #error "This file should not be included by userland programs." 35 #endif 36 37 /* 38 * Forward declarations 39 */ 40 typedef struct kobj *kobj_t; 41 typedef struct kobj_class *kobj_class_t; 42 typedef struct kobj_method kobj_method_t; 43 typedef int (*kobjop_t)(void); 44 typedef struct kobj_ops *kobj_ops_t; 45 typedef struct kobjop_desc *kobjop_desc_t; 46 struct malloc_type; 47 48 struct kobj_method { 49 kobjop_desc_t desc; 50 kobjop_t func; 51 }; 52 53 /* 54 * A class is simply a method table and a sizeof value. When the first 55 * instance of the class is created, the method table will be compiled 56 * into a form more suited to efficient method dispatch. This compiled 57 * method table is always the first field of the object. 58 */ 59 #define KOBJ_CLASS_FIELDS \ 60 const char *name; /* class name */ \ 61 kobj_method_t *methods; /* method table */ \ 62 size_t size; /* object size */ \ 63 kobj_class_t *baseclasses; /* base classes */ \ 64 u_int refs; /* reference count */ \ 65 kobj_ops_t ops /* compiled method table */ 66 67 struct kobj_class { 68 KOBJ_CLASS_FIELDS; 69 }; 70 71 /* 72 * Implementation of kobj. 73 */ 74 #define KOBJ_FIELDS \ 75 kobj_ops_t ops 76 77 struct kobj { 78 KOBJ_FIELDS; 79 }; 80 81 /* 82 * The ops table is used as a cache of results from kobj_lookup_method(). 83 */ 84 85 #define KOBJ_CACHE_SIZE 256 86 87 struct kobj_ops { 88 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 89 kobj_class_t cls; 90 }; 91 92 struct kobjop_desc { 93 unsigned int id; /* unique ID */ 94 kobj_method_t *deflt; /* default implementation */ 95 }; 96 97 /* 98 * Shorthand for constructing method tables. 99 */ 100 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC } 101 102 /* 103 * Declare a class (which should be defined in another file. 104 */ 105 #define DECLARE_CLASS(name) extern struct kobj_class name 106 107 /* 108 * Define a class with no base classes (api backward-compatible. with 109 * FreeBSD-5.1 and earlier). 110 */ 111 #define DEFINE_CLASS(name, methods, size) \ 112 DEFINE_CLASS_0(name, name ## _class, methods, size) 113 114 /* 115 * Define a class with no base classes. Use like this: 116 * 117 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); 118 */ 119 #define DEFINE_CLASS_0(name, classvar, methods, size) \ 120 \ 121 struct kobj_class classvar = { \ 122 #name, methods, size, NULL, 0, NULL \ 123 } 124 125 /* 126 * Define a class inheriting a single base class. Use like this: 127 * 128 * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc), 129 * bar); 130 */ 131 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 132 base1) \ 133 \ 134 static kobj_class_t name ## _baseclasses[] = { \ 135 &base1, 0 \ 136 }; \ 137 struct kobj_class classvar = { \ 138 #name, methods, size, name ## _baseclasses \ 139 } 140 141 /* 142 * Define a class inheriting two base classes. Use like this: 143 * 144 * DEFINE_CLASS2(foo, foo_class, foo_methods, sizeof(foo_softc), 145 * bar, baz); 146 */ 147 #define DEFINE_CLASS_2(name, methods, size, \ 148 base1, base2) \ 149 \ 150 static kobj_class_t name ## _baseclasses[] = { \ 151 &base1, \ 152 &base2, 0 \ 153 }; \ 154 struct kobj_class name ## _class = { \ 155 #name, methods, size, name ## _baseclasses \ 156 } 157 158 /* 159 * Define a class inheriting three base classes. Use like this: 160 * 161 * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc), 162 * bar, baz, foobar); 163 */ 164 #define DEFINE_CLASS_3(name, methods, size, \ 165 base1, base2, base3) \ 166 \ 167 static kobj_class_t name ## _baseclasses[] = { \ 168 &base1, \ 169 &base2, \ 170 &base3, 0 \ 171 }; \ 172 struct kobj_class name ## _class = { \ 173 #name, methods, size, name ## _baseclasses \ 174 } 175 176 #ifdef _KERNEL 177 178 /* 179 * Compile class for the first instance and add a reference. 180 */ 181 void kobj_class_instantiate(kobj_class_t cls); 182 183 /* 184 * Remove a reference and free method table with the last instance. 185 */ 186 void kobj_class_uninstantiate(kobj_class_t cls); 187 188 /* 189 * Allocate memory for and initialise a new object. 190 */ 191 kobj_t kobj_create(kobj_class_t cls, 192 struct malloc_type *mtype, 193 int mflags); 194 195 /* 196 * Initialise a pre-allocated object. 197 */ 198 void kobj_init(kobj_t obj, kobj_class_t cls); 199 200 /* 201 * Delete an object. If mtype is non-zero, free the memory. 202 */ 203 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 204 205 /* 206 * Maintain stats on hits/misses in lookup caches. 207 */ 208 #ifdef KOBJ_STATS 209 extern u_int kobj_lookup_hits; 210 extern u_int kobj_lookup_misses; 211 #endif 212 213 /* 214 * Lookup the method in the cache and if it isn't there look it up the 215 * slow way. 216 */ 217 #ifdef KOBJ_STATS 218 #define KOBJOPLOOKUP(OPS,OP) do { \ 219 kobjop_desc_t _desc = &OP##_##desc; \ 220 kobj_method_t **_cep = \ 221 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 222 kobj_method_t *_ce = *_cep; \ 223 kobj_lookup_hits++; /* assume hit */ \ 224 if (_ce->desc != _desc) \ 225 _ce = kobj_lookup_method(OPS->cls, \ 226 _cep, _desc); \ 227 _m = _ce->func; \ 228 } while(0) 229 #else 230 #define KOBJOPLOOKUP(OPS,OP) do { \ 231 kobjop_desc_t _desc = &OP##_##desc; \ 232 kobj_method_t **_cep = \ 233 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 234 kobj_method_t *_ce = *_cep; \ 235 if (_ce->desc != _desc) \ 236 _ce = kobj_lookup_method(OPS->cls, \ 237 _cep, _desc); \ 238 _m = _ce->func; \ 239 } while(0) 240 #endif 241 242 kobj_method_t *kobj_lookup_method(kobj_class_t cls, 243 kobj_method_t **cep, 244 kobjop_desc_t desc); 245 246 /* 247 * Default method implementation. Returns ENXIO. 248 */ 249 int kobj_error_method(void); 250 251 #endif /* _KERNEL */ 252 253 #endif /* !_SYS_KOBJ_H_ */ 254