2 * Copyright (c) 2000 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/sys/sys/kobj.h,v 1.5.2.1 2001/02/02 19:49:14 cg Exp $
27 * $DragonFly: src/sys/sys/kobj.h,v 1.2 2003/06/17 04:28:58 dillon Exp $
34 * Forward declarations
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;
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.
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 */
67 * Implementation of kobj.
77 * The ops table is used as a cache of results from kobj_lookup_method().
80 #define KOBJ_CACHE_SIZE 256
83 kobj_method_t cache[KOBJ_CACHE_SIZE];
88 unsigned int id; /* unique ID */
89 kobjop_t deflt; /* default implementation */
93 * Shorthand for constructing method tables.
95 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC }
97 #define DEFINE_CLASS(name, methods, size) \
99 struct kobj_class name ## _class = { \
100 #name, methods, size \
104 * Compile the method table in a class.
106 void kobj_class_compile(kobj_class_t cls);
109 * Compile the method table, with the caller providing the space for
110 * the ops table.(for use before malloc is initialised).
112 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops);
115 * Free the compiled method table in a class.
117 void kobj_class_free(kobj_class_t cls);
120 * Allocate memory for and initalise a new object.
122 kobj_t kobj_create(kobj_class_t cls,
123 struct malloc_type *mtype,
127 * Initialise a pre-allocated object.
129 void kobj_init(kobj_t obj, kobj_class_t cls);
132 * Delete an object. If mtype is non-zero, free the memory.
134 void kobj_delete(kobj_t obj, struct malloc_type *mtype);
137 * Maintain stats on hits/misses in lookup caches.
140 extern int kobj_lookup_hits;
141 extern int kobj_lookup_misses;
142 #define KOBJOPHIT do { kobj_lookup_hits++; } while (0)
143 #define KOBJOPMISS do { kobj_lookup_misses++; } while (0)
145 #define KOBJOPHIT do { } while (0)
146 #define KOBJOPMISS do { } while (0)
150 * Lookup the method in the cache and if it isn't there look it up the
153 #define KOBJOPLOOKUP(OPS,OP) do { \
154 kobjop_desc_t _desc = &OP##_##desc; \
155 kobj_method_t *_ce = \
156 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \
157 if (_ce->desc != _desc) { \
159 kobj_lookup_method(OPS->cls->methods, _ce, _desc); \
166 void kobj_lookup_method(kobj_method_t *methods,
170 #endif /* !_SYS_KOBJ_H_ */