1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 29#ifndef _SYS_KOBJ_H_ 30#define _SYS_KOBJ_H_ 31 32/* 33 * Forward declarations 34 */ 35typedef struct kobj *kobj_t; 36typedef struct kobj_class *kobj_class_t; 37typedef const struct kobj_method kobj_method_t; 38typedef void (*kobjop_t)(void); 39typedef struct kobj_ops *kobj_ops_t; 40typedef struct kobjop_desc *kobjop_desc_t; 41struct malloc_type; 42 43struct kobj_method { 44 kobjop_desc_t desc; 45 kobjop_t func; 46}; 47 48/* 49 * A class is simply a method table and a sizeof value. When the first 50 * instance of the class is created, the method table will be compiled 51 * into a form more suited to efficient method dispatch. This compiled 52 * method table is always the first field of the object. 53 */ 54#define KOBJ_CLASS_FIELDS \ 55 const char *name; /* class name */ \ 56 kobj_method_t *methods; /* method table */ \ 57 size_t size; /* object size */ \ 58 kobj_class_t *baseclasses; /* base classes */ \ 59 u_int refs; /* reference count */ \ 60 kobj_ops_t ops /* compiled method table */ 61 62struct kobj_class { 63 KOBJ_CLASS_FIELDS; 64}; 65 66/* 67 * Implementation of kobj. 68 */ 69#define KOBJ_FIELDS \ 70 kobj_ops_t ops 71 72struct kobj { 73 KOBJ_FIELDS; 74}; 75 76/* 77 * The ops table is used as a cache of results from kobj_lookup_method(). 78 */ 79 80#define KOBJ_CACHE_SIZE 256 81 82struct kobj_ops { 83 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 84 kobj_class_t cls; 85}; 86 87struct kobjop_desc { 88 unsigned int id; /* unique ID */ 89 kobj_method_t deflt; /* default implementation */ 90}; 91 92/* 93 * Shorthand for constructing method tables. 94 * The ternary operator is (ab)used to provoke a warning when FUNC 95 * has a signature that is not compatible with kobj method signature. 96 */ 97#define KOBJMETHOD(NAME, FUNC) \ 98 { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) } 99 100/* 101 * 102 */ 103#define KOBJMETHOD_END { NULL, NULL } 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) \ 115DEFINE_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 \ 124struct kobj_class classvar = { \ 125 #name, methods, size, NULL \ 126} 127 128/* 129 * Define a class inheriting a single base class. Use like this: 130 * 131 * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc), 132 * bar); 133 */ 134#define DEFINE_CLASS_1(name, classvar, methods, size, \ 135 base1) \ 136 \ 137static kobj_class_t name ## _baseclasses[] = \ 138 { &base1, NULL }; \ 139struct kobj_class classvar = { \ 140 #name, methods, size, name ## _baseclasses \ 141} 142 143/* 144 * Define a class inheriting two base classes. Use like this: 145 * 146 * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc), 147 * bar, baz); 148 */ 149#define DEFINE_CLASS_2(name, classvar, methods, size, \ 150 base1, base2) \ 151 \ 152static kobj_class_t name ## _baseclasses[] = \ 153 { &base1, \ 154 &base2, NULL }; \ 155struct kobj_class classvar = { \ 156 #name, methods, size, name ## _baseclasses \ 157} 158 159/* 160 * Define a class inheriting three base classes. Use like this: 161 * 162 * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc), 163 * bar, baz, foobar); 164 */ 165#define DEFINE_CLASS_3(name, classvar, methods, size, \ 166 base1, base2, base3) \ 167 \ 168static kobj_class_t name ## _baseclasses[] = \ 169 { &base1, \ 170 &base2, \ 171 &base3, NULL }; \ 172struct kobj_class classvar = { \ 173 #name, methods, size, name ## _baseclasses \ 174} 175 176/* 177 * Compile the method table in a class. 178 */ 179void kobj_class_compile(kobj_class_t cls); 180 181/* 182 * Compile the method table, with the caller providing the space for 183 * the ops table.(for use before malloc is initialised). 184 */ 185void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops); 186 187/* 188 * Free the compiled method table in a class. 189 */ 190void kobj_class_free(kobj_class_t cls); 191 192/* 193 * Allocate memory for and initialise a new object. 194 */ 195kobj_t kobj_create(kobj_class_t cls, 196 struct malloc_type *mtype, 197 int mflags); 198 199/* 200 * Initialise a pre-allocated object. 201 */ 202void kobj_init(kobj_t obj, kobj_class_t cls); 203void kobj_init_static(kobj_t obj, kobj_class_t cls); 204 205/* 206 * Delete an object. If mtype is non-zero, free the memory. 207 */ 208void kobj_delete(kobj_t obj, struct malloc_type *mtype); 209 210/* 211 * Maintain stats on hits/misses in lookup caches. 212 */ 213#ifdef KOBJ_STATS 214extern u_int kobj_lookup_hits; 215extern u_int kobj_lookup_misses; 216#endif 217 218/* 219 * Lookup the method in the cache and if it isn't there look it up the 220 * slow way. 221 */ 222#ifdef KOBJ_STATS 223#define KOBJOPLOOKUP(OPS,OP) do { \ 224 kobjop_desc_t _desc = &OP##_##desc; \ 225 kobj_method_t **_cep = \ 226 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 227 kobj_method_t *_ce = *_cep; \ 228 if (_ce->desc != _desc) { \ 229 _ce = kobj_lookup_method(OPS->cls, \ 230 _cep, _desc); \ 231 kobj_lookup_misses++; \ 232 } else \ 233 kobj_lookup_hits++; \ 234 _m = _ce->func; \ 235} while (0) 236#else 237#define KOBJOPLOOKUP(OPS,OP) do { \ 238 kobjop_desc_t _desc = &OP##_##desc; \ 239 kobj_method_t **_cep = \ 240 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 241 kobj_method_t *_ce = *_cep; \ 242 if (_ce->desc != _desc) \ 243 _ce = kobj_lookup_method(OPS->cls, \ 244 _cep, _desc); \ 245 _m = _ce->func; \ 246} while (0) 247#endif 248 249kobj_method_t* kobj_lookup_method(kobj_class_t cls, 250 kobj_method_t **cep, 251 kobjop_desc_t desc); 252 253/* 254 * Default method implementation. Returns ENXIO. 255 */ 256int kobj_error_method(void); 257 258#endif /* !_SYS_KOBJ_H_ */ 259