/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2000,2003 Doug Rabson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_KOBJ_H_ #define _SYS_KOBJ_H_ #include <sys/types.h> /* * Forward declarations */ typedef struct kobj *kobj_t; typedef struct kobj_class *kobj_class_t; typedef const struct kobj_method kobj_method_t; typedef void (*kobjop_t)(void); typedef struct kobj_ops *kobj_ops_t; typedef struct kobjop_desc *kobjop_desc_t; struct malloc_type; struct kobj_method { kobjop_desc_t desc; kobjop_t func; }; /* * A class is simply a method table and a sizeof value. When the first * instance of the class is created, the method table will be compiled * into a form more suited to efficient method dispatch. This compiled * method table is always the first field of the object. */ #define KOBJ_CLASS_FIELDS \ const char *name; /* class name */ \ kobj_method_t *methods; /* method table */ \ size_t size; /* object size */ \ kobj_class_t *baseclasses; /* base classes */ \ u_int refs; /* reference count */ \ kobj_ops_t ops /* compiled method table */ struct kobj_class { KOBJ_CLASS_FIELDS; }; /* * Implementation of kobj. */ #define KOBJ_FIELDS \ kobj_ops_t ops struct kobj { KOBJ_FIELDS; }; /* * The ops table is used as a cache of results from kobj_lookup_method(). */ #define KOBJ_CACHE_SIZE 256 struct kobj_ops { kobj_method_t *cache[KOBJ_CACHE_SIZE]; kobj_class_t cls; }; struct kobjop_desc { unsigned int id; /* unique ID */ kobj_method_t deflt; /* default implementation */ }; /* * Shorthand for constructing method tables. * The ternary operator is (ab)used to provoke a warning when FUNC * has a signature that is not compatible with kobj method signature. */ #define KOBJMETHOD(NAME, FUNC) \ { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) } /* * */ #define KOBJMETHOD_END { NULL, NULL } /* * Declare a class (which should be defined in another file. */ #define DECLARE_CLASS(name) extern struct kobj_class name /* * Define a class with no base classes (api backward-compatible. with * FreeBSD-5.1 and earlier). */ #define DEFINE_CLASS(name, methods, size) \ DEFINE_CLASS_0(name, name ## _class, methods, size) /* * Define a class with no base classes. Use like this: * * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); */ #define DEFINE_CLASS_0(name, classvar, methods, size) \ \ struct kobj_class classvar = { \ #name, methods, size, NULL \ } /* * Define a class inheriting a single base class. Use like this: * * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc), * bar); */ #define DEFINE_CLASS_1(name, classvar, methods, size, \ base1) \ \ static kobj_class_t name ## _baseclasses[] = \ { &base1, NULL }; \ struct kobj_class classvar = { \ #name, methods, size, name ## _baseclasses \ } /* * Define a class inheriting two base classes. Use like this: * * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc), * bar, baz); */ #define DEFINE_CLASS_2(name, classvar, methods, size, \ base1, base2) \ \ static kobj_class_t name ## _baseclasses[] = \ { &base1, \ &base2, NULL }; \ struct kobj_class classvar = { \ #name, methods, size, name ## _baseclasses \ } /* * Define a class inheriting three base classes. Use like this: * * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc), * bar, baz, foobar); */ #define DEFINE_CLASS_3(name, classvar, methods, size, \ base1, base2, base3) \ \ static kobj_class_t name ## _baseclasses[] = \ { &base1, \ &base2, \ &base3, NULL }; \ struct kobj_class classvar = { \ #name, methods, size, name ## _baseclasses \ } /* * Compile the method table in a class. */ void kobj_class_compile(kobj_class_t cls); /* * Compile the method table, with the caller providing the space for * the ops table.(for use before malloc is initialised). */ void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops); /* * Free the compiled method table in a class. */ void kobj_class_free(kobj_class_t cls); /* * Allocate memory for and initialise a new object. */ kobj_t kobj_create(kobj_class_t cls, struct malloc_type *mtype, int mflags); /* * Initialise a pre-allocated object. */ void kobj_init(kobj_t obj, kobj_class_t cls); void kobj_init_static(kobj_t obj, kobj_class_t cls); /* * Delete an object. If mtype is non-zero, free the memory. */ void kobj_delete(kobj_t obj, struct malloc_type *mtype); /* * Maintain stats on hits/misses in lookup caches. */ #ifdef KOBJ_STATS extern u_int kobj_lookup_hits; extern u_int kobj_lookup_misses; #endif /* * Lookup the method in the cache and if it isn't there look it up the * slow way. */ #ifdef KOBJ_STATS #define KOBJOPLOOKUP(OPS,OP) do { \ kobjop_desc_t _desc = &OP##_##desc; \ kobj_method_t **_cep = \ &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ kobj_method_t *_ce = *_cep; \ if (_ce->desc != _desc) { \ _ce = kobj_lookup_method(OPS->cls, \ _cep, _desc); \ kobj_lookup_misses++; \ } else \ kobj_lookup_hits++; \ _m = _ce->func; \ } while (0) #else #define KOBJOPLOOKUP(OPS,OP) do { \ kobjop_desc_t _desc = &OP##_##desc; \ kobj_method_t **_cep = \ &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ kobj_method_t *_ce = *_cep; \ if (_ce->desc != _desc) \ _ce = kobj_lookup_method(OPS->cls, \ _cep, _desc); \ _m = _ce->func; \ } while (0) #endif kobj_method_t* kobj_lookup_method(kobj_class_t cls, kobj_method_t **cep, kobjop_desc_t desc); /* * Default method implementation. Returns ENXIO. */ int kobj_error_method(void); #endif /* !_SYS_KOBJ_H_ */
