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 1.7 2004/04/14 18:28:29 joerg Exp $ 28 */ 29 30 #ifndef _SYS_KOBJ_H_ 31 #define _SYS_KOBJ_H_ 32 33 /* 34 * Forward declarations 35 */ 36 typedef struct kobj *kobj_t; 37 typedef struct kobj_class *kobj_class_t; 38 typedef struct kobj_method kobj_method_t; 39 typedef int (*kobjop_t)(void); 40 typedef struct kobj_ops *kobj_ops_t; 41 typedef struct kobjop_desc *kobjop_desc_t; 42 struct malloc_type; 43 44 struct kobj_method { 45 kobjop_desc_t desc; 46 kobjop_t func; 47 }; 48 49 /* 50 * A class is simply a method table and a sizeof value. When the first 51 * instance of the class is created, the method table will be compiled 52 * into a form more suited to efficient method dispatch. This compiled 53 * method table is always the first field of the object. 54 */ 55 #define KOBJ_CLASS_FIELDS \ 56 const char *name; /* class name */ \ 57 kobj_method_t *methods; /* method table */ \ 58 size_t size; /* object size */ \ 59 kobj_class_t *baseclasses; /* base classes */ \ 60 u_int refs; /* reference count */ \ 61 kobj_ops_t ops /* compiled method table */ 62 63 struct kobj_class { 64 KOBJ_CLASS_FIELDS; 65 }; 66 67 /* 68 * Implementation of kobj. 69 */ 70 #define KOBJ_FIELDS \ 71 kobj_ops_t ops 72 73 struct kobj { 74 KOBJ_FIELDS; 75 }; 76 77 /* 78 * The ops table is used as a cache of results from kobj_lookup_method(). 79 */ 80 81 #define KOBJ_CACHE_SIZE 256 82 83 struct kobj_ops { 84 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 85 kobj_class_t cls; 86 }; 87 88 struct kobjop_desc { 89 unsigned int id; /* unique ID */ 90 kobj_method_t *deflt; /* default implementation */ 91 }; 92 93 /* 94 * Shorthand for constructing method tables. 95 */ 96 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC } 97 98 /* 99 * Declare a class (which should be defined in another file. 100 */ 101 #define DECLARE_CLASS(name) extern struct kobj_class name 102 103 /* 104 * Define a class with no base classes (api backward-compatible. with 105 * FreeBSD-5.1 and earlier). 106 */ 107 #define DEFINE_CLASS(name, methods, size) \ 108 DEFINE_CLASS_0(name, name ## _class, methods, size) 109 110 /* 111 * Define a class with no base classes. Use like this: 112 * 113 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); 114 */ 115 #define DEFINE_CLASS_0(name, classvar, methods, size) \ 116 \ 117 struct kobj_class classvar = { \ 118 #name, methods, size, 0 \ 119 } 120 121 /* 122 * Define a class inheriting a single base class. Use like this: 123 * 124 * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc), 125 * bar); 126 */ 127 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 128 base1) \ 129 \ 130 static kobj_class_t name ## _baseclasses[] = { \ 131 &base1, 0 \ 132 }; \ 133 struct kobj_class classvar = { \ 134 #name, methods, size, name ## _baseclasses \ 135 } 136 137 /* 138 * Define a class inheriting two base classes. Use like this: 139 * 140 * DEFINE_CLASS2(foo, foo_class, foo_methods, sizeof(foo_softc), 141 * bar, baz); 142 */ 143 #define DEFINE_CLASS_2(name, methods, size, \ 144 base1, base2) \ 145 \ 146 static kobj_class_t name ## _baseclasses[] = { \ 147 &base1, \ 148 &base2, 0 \ 149 }; \ 150 struct kobj_class name ## _class = { \ 151 #name, methods, size, name ## _baseclasses \ 152 } 153 154 /* 155 * Define a class inheriting three base classes. Use like this: 156 * 157 * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc), 158 * bar, baz, foobar); 159 */ 160 #define DEFINE_CLASS_3(name, methods, size, \ 161 base1, base2, base3) \ 162 \ 163 static kobj_class_t name ## _baseclasses[] = { \ 164 &base1, \ 165 &base2, \ 166 &base3, 0 \ 167 }; \ 168 struct kobj_class name ## _class = { \ 169 #name, methods, size, name ## _baseclasses \ 170 } 171 172 /* 173 * Compile class for the first instance and add a reference. 174 */ 175 void kobj_class_instantiate(kobj_class_t cls); 176 177 /* 178 * Remove a reference and free method table with the last instance. 179 */ 180 void kobj_class_uninstantiate(kobj_class_t cls); 181 182 /* 183 * Allocate memory for and initialise a new object. 184 */ 185 kobj_t kobj_create(kobj_class_t cls, 186 struct malloc_type *mtype, 187 int mflags); 188 189 /* 190 * Initialise a pre-allocated object. 191 */ 192 void kobj_init(kobj_t obj, kobj_class_t cls); 193 194 /* 195 * Delete an object. If mtype is non-zero, free the memory. 196 */ 197 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 198 199 /* 200 * Maintain stats on hits/misses in lookup caches. 201 */ 202 #ifdef KOBJ_STATS 203 extern u_int kobj_lookup_hits; 204 extern u_int kobj_lookup_misses; 205 #endif 206 207 /* 208 * Lookup the method in the cache and if it isn't there look it up the 209 * slow way. 210 */ 211 #ifdef KOBJ_STATS 212 #define KOBJOPLOOKUP(OPS,OP) do { \ 213 kobjop_desc_t _desc = &OP##_##desc; \ 214 kobj_method_t **_cep = \ 215 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 216 kobj_method_t *_ce = *_cep; \ 217 kobj_lookup_hits++; /* assume hit */ \ 218 if (_ce->desc != _desc) \ 219 _ce = kobj_lookup_method(OPS->cls, \ 220 _cep, _desc); \ 221 _m = _ce->func; \ 222 } while(0) 223 #else 224 #define KOBJOPLOOKUP(OPS,OP) do { \ 225 kobjop_desc_t _desc = &OP##_##desc; \ 226 kobj_method_t **_cep = \ 227 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 228 kobj_method_t *_ce = *_cep; \ 229 if (_ce->desc != _desc) \ 230 _ce = kobj_lookup_method(OPS->cls, \ 231 _cep, _desc); \ 232 _m = _ce->func; \ 233 } while(0) 234 #endif 235 236 kobj_method_t *kobj_lookup_method(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 /* !_SYS_KOBJ_H_ */ 246