usr/src/cmd/sgs/rtld/common/cache_a.out.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  *      Copyright (c) 1998 by Sun Microsystems, Inc.
  24  */
  25 #ifndef _CACHE_DOT_H
  26 #define _CACHE_DOT_H
  27
  28 #pragma ident   "%Z%%M% %I%     %E% SMI"
  29
  30 /*
  31  * ld.so directory caching
  32  */
  33 #include        <sys/types.h>
  34
  35 /*
  36  * Shared object lookup performance in the run-time link editor is
  37  * enhanced through the use of caches for directories that the editor
  38  * searches.  A given "cache" describes the contents of a single directory,
  39  * and each cache entry contains the canonical name for a shared object
  40  * as well as its absolute pathname.
  41  *
  42  * Within a cache, "pointers" are really relative addresses to some absolute
  43  * address (often the base address of the containing database).
  44  */
  45
  46 /*
  47  * Relative pointer macros.
  48  */
  49 #define RELPTR(base, absptr) ((long)(absptr) - (long)(base))
  50 #define AP(base) ((caddr_t)base)
  51
  52 /*
  53  * Definitions for cache structures.
  54  */
  55 #define DB_HASH         11              /* number of hash buckets in caches */
  56 #define LD_CACHE_MAGIC  0x041155        /* cookie to identify data structure */
  57 #define LD_CACHE_VERSION 0              /* version number of cache structure */
  58
  59 struct  dbe     {                       /* element of a directory cache */
  60         long    dbe_next;               /* (rp) next element on this list */
  61         long    dbe_lop;                /* (rp) canonical name for object */
  62         long    dbe_name;               /* (rp) absolute name */
  63 };
  64
  65 struct  db      {                       /* directory cache database */
  66         long    db_name;                /* (rp) directory contained here */
  67         struct  dbe db_hash[DB_HASH];   /* hash buckets */
  68         caddr_t db_chain;               /* private to database mapping */
  69 };
  70
  71 struct dbf      {                       /* cache file image */
  72         long dbf_magic;                 /* identifying cookie */
  73         long dbf_version;               /* version no. of these dbs */
  74         long dbf_machtype;              /* machine type */
  75         long dbf_db;            /* directory cache dbs */
  76 };
  77
  78 /*
  79  * Structures used to describe and access a database.
  80  */
  81 struct  dbd     {                       /* data base descriptor */
  82         struct  dbd *dbd_next;          /* next one on this list */
  83         struct  db *dbd_db;             /* data base described by this */
  84 };
  85
  86 struct  dd      {                       /* directory descriptor */
  87         struct  dd *dd_next;            /* next one on this list */
  88         struct  db *dd_db;              /* data base described by this */
  89 };
  90
  91 /*
  92  * Interfaces imported/exported by the lookup code.
  93  */
  94
  95 char    *ask_db();                      /* ask db for highest minor number */
  96 struct  db *lo_cache();                 /* obtain cache for directory name */
  97
  98 #endif