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 1.5 2004/02/29 17:18:32 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 u_int refs; /* reference count */ \ 60 kobj_ops_t ops /* compiled method table */ 61 62 struct kobj_class { 63 KOBJ_CLASS_FIELDS; 64 }; 65 66 /* 67 * Implementation of kobj. 68 */ 69 #define KOBJ_FIELDS \ 70 kobj_ops_t ops 71 72 struct 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 82 struct kobj_ops { 83 kobj_method_t cache[KOBJ_CACHE_SIZE]; 84 kobj_class_t cls; 85 }; 86 87 struct kobjop_desc { 88 unsigned int id; /* unique ID */ 89 kobjop_t deflt; /* default implementation */ 90 }; 91 92 /* 93 * Shorthand for constructing method tables. 94 */ 95 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC } 96 97 #define DEFINE_CLASS(name, methods, size) \ 98 \ 99 struct kobj_class name ## _class = { \ 100 #name, methods, size \ 101 } 102 103 /* 104 * Compile the method table in a class. 105 */ 106 void kobj_class_compile(kobj_class_t cls); 107 108 /* 109 * Compile the method table, with the caller providing the space for 110 * the ops table.(for use before malloc is initialised). 111 */ 112 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops); 113 114 /* 115 * Free the compiled method table in a class. 116 */ 117 void kobj_class_free(kobj_class_t cls); 118 119 /* 120 * Allocate memory for and initialise a new object. 121 */ 122 kobj_t kobj_create(kobj_class_t cls, 123 struct malloc_type *mtype, 124 int mflags); 125 126 /* 127 * Initialise a pre-allocated object. 128 */ 129 void kobj_init(kobj_t obj, kobj_class_t cls); 130 131 /* 132 * Delete an object. If mtype is non-zero, free the memory. 133 */ 134 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 135 136 /* 137 * Maintain stats on hits/misses in lookup caches. 138 */ 139 #ifdef KOBJ_STATS 140 extern u_int kobj_lookup_hits; 141 extern u_int kobj_lookup_misses; 142 #endif 143 144 /* 145 * Lookup the method in the cache and if it isn't there look it up the 146 * slow way. 147 */ 148 #ifdef KOBJ_STATS 149 #define KOBJOPLOOKUP(OPS,OP) do { \ 150 kobjop_desc_t _desc = &OP##_##desc; \ 151 kobj_method_t *_ce = \ 152 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 153 if (_ce->desc != _desc) { \ 154 kobj_lookup_misses++; \ 155 kobj_lookup_method(OPS->cls->methods, _ce, _desc); \ 156 } else { \ 157 kobj_lookup_hits++; \ 158 } \ 159 _m = _ce->func; \ 160 } while(0) 161 #else 162 #define KOBJOPLOOKUP(OPS,OP) do { \ 163 kobjop_desc_t _desc = &OP##_##desc; \ 164 kobj_method_t *_ce = &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 165 if (_ce->desc != _desc) \ 166 kobj_lookup_method(OPS->cls->methods, _ce, _desc); \ 167 _m = _ce->func; \ 168 } while(0) 169 #endif /* !KOBJ_STATS */ 170 171 void kobj_lookup_method(kobj_method_t *methods, 172 kobj_method_t *ce, 173 kobjop_desc_t desc); 174 175 #endif /* !_SYS_KOBJ_H_ */ 176