1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2000,2003 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef _SYS_KOBJ_H_ 32 #define _SYS_KOBJ_H_ 33 34 /* 35 * Forward declarations 36 */ 37 typedef struct kobj *kobj_t; 38 typedef struct kobj_class *kobj_class_t; 39 typedef const struct kobj_method kobj_method_t; 40 typedef int (*kobjop_t)(void); 41 typedef struct kobj_ops *kobj_ops_t; 42 typedef struct kobjop_desc *kobjop_desc_t; 43 struct malloc_type; 44 45 struct kobj_method { 46 kobjop_desc_t desc; 47 kobjop_t func; 48 }; 49 50 /* 51 * A class is simply a method table and a sizeof value. When the first 52 * instance of the class is created, the method table will be compiled 53 * into a form more suited to efficient method dispatch. This compiled 54 * method table is always the first field of the object. 55 */ 56 #define KOBJ_CLASS_FIELDS \ 57 const char *name; /* class name */ \ 58 kobj_method_t *methods; /* method table */ \ 59 size_t size; /* object size */ \ 60 kobj_class_t *baseclasses; /* base classes */ \ 61 u_int refs; /* reference count */ \ 62 kobj_ops_t ops /* compiled method table */ 63 64 struct kobj_class { 65 KOBJ_CLASS_FIELDS; 66 }; 67 68 /* 69 * Implementation of kobj. 70 */ 71 #define KOBJ_FIELDS \ 72 kobj_ops_t ops 73 74 struct kobj { 75 KOBJ_FIELDS; 76 }; 77 78 /* 79 * The ops table is used as a cache of results from kobj_lookup_method(). 80 */ 81 82 #define KOBJ_CACHE_SIZE 256 83 84 struct kobj_ops { 85 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 86 kobj_class_t cls; 87 }; 88 89 struct kobjop_desc { 90 unsigned int id; /* unique ID */ 91 kobj_method_t deflt; /* default implementation */ 92 }; 93 94 /* 95 * Shorthand for constructing method tables. 96 * The ternary operator is (ab)used to provoke a warning when FUNC 97 * has a signature that is not compatible with kobj method signature. 98 */ 99 #define KOBJMETHOD(NAME, FUNC) \ 100 { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) } 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, classvar, methods, size, \ 152 base1, base2) \ 153 \ 154 static kobj_class_t name ## _baseclasses[] = \ 155 { &base1, \ 156 &base2, NULL }; \ 157 struct kobj_class classvar = { \ 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, classvar, 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 classvar = { \ 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 void kobj_init_static(kobj_t obj, kobj_class_t cls); 207 208 /* 209 * Delete an object. If mtype is non-zero, free the memory. 210 */ 211 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 212 213 /* 214 * Maintain stats on hits/misses in lookup caches. 215 */ 216 #ifdef KOBJ_STATS 217 extern u_int kobj_lookup_hits; 218 extern u_int kobj_lookup_misses; 219 #endif 220 221 /* 222 * Lookup the method in the cache and if it isn't there look it up the 223 * slow way. 224 */ 225 #ifdef KOBJ_STATS 226 #define KOBJOPLOOKUP(OPS,OP) do { \ 227 kobjop_desc_t _desc = &OP##_##desc; \ 228 kobj_method_t **_cep = \ 229 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 230 kobj_method_t *_ce = *_cep; \ 231 if (_ce->desc != _desc) { \ 232 _ce = kobj_lookup_method(OPS->cls, \ 233 _cep, _desc); \ 234 kobj_lookup_misses++; \ 235 } else \ 236 kobj_lookup_hits++; \ 237 _m = _ce->func; \ 238 } while(0) 239 #else 240 #define KOBJOPLOOKUP(OPS,OP) do { \ 241 kobjop_desc_t _desc = &OP##_##desc; \ 242 kobj_method_t **_cep = \ 243 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 244 kobj_method_t *_ce = *_cep; \ 245 if (_ce->desc != _desc) \ 246 _ce = kobj_lookup_method(OPS->cls, \ 247 _cep, _desc); \ 248 _m = _ce->func; \ 249 } while(0) 250 #endif 251 252 kobj_method_t* kobj_lookup_method(kobj_class_t cls, 253 kobj_method_t **cep, 254 kobjop_desc_t desc); 255 256 257 /* 258 * Default method implementation. Returns ENXIO. 259 */ 260 int kobj_error_method(void); 261 262 #endif /* !_SYS_KOBJ_H_ */ 263