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   1 /* -*-c-*-
   2  *
   3  * $Id: mparena.h,v 1.2 1999/12/10 23:28:59 mdw Exp $
   4  *
   5  * Allocation and freeing of MP buffers
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: mparena.h,v $
  33  * Revision 1.2  1999/12/10 23:28:59  mdw
  34  * Memory allocation counting.
  35  *
  36  * Revision 1.1  1999/11/17 18:02:16  mdw
  37  * New multiprecision integer arithmetic suite.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_MPARENA_H
  42 #define CATACOMB_MPARENA_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Header files ------------------------------------------------------*/
  49
  50 #ifndef CATACOMB_MPW_H
  51 #  include "mpw.h"
  52 #endif
  53
  54 /*----- Data structures ---------------------------------------------------*/
  55
  56 /* --- @mparena_node@ --- *
  57  *
  58  * For internal use by the MP arena manager.  The free blocks are held in a
  59  * binary tree by size, held in the first digit of each vector.
  60  */
  61
  62 typedef struct mparena_node {
  63   struct mparena_node *left, *right;
  64   mpw *v;
  65 } mparena_node;
  66
  67 /* --- @mparena@ --- *
  68  *
  69  * The actual arena.
  70  */
  71
  72 typedef struct mparena {
  73   mparena_node *root;
  74   unsigned n;
  75   struct mparena_ops *ops;
  76 } mparena;
  77
  78 /* --- @mparena_ops@ --- *
  79  *
  80  * Operations required for an arena memory manager.  The default manager just
  81  * calls @xmalloc@ and @free@, although it's possible to envisage a more
  82  * paranoid implementation which allocates locked memory pages.  Switch them
  83  * over with @mparena_setops@.  It's usual to only do this when you've
  84  * attached your extra state to the end of the @mparena@ structure.
  85  */
  86
  87 typedef struct mparena_ops {
  88   void *(*alloc)(mparena */*a*/, size_t /*sz*/);
  89   void (*free)(mparena */*a*/, void */*p*/);
  90 } mparena_ops;
  91
  92 /*----- Magical constants -------------------------------------------------*/
  93
  94 #define MPARENA_GLOBAL ((mparena *)0)
  95
  96 extern mparena_ops mparena_defaultops;
  97
  98 /*----- Functions provided ------------------------------------------------*/
  99
 100 /* --- @mparena_create@ --- *
 101  *
 102  * Arguments:   @mparena *a@ = pointer to arena block
 103  *
 104  * Returns:     ---
 105  *
 106  * Use:         Initializes an MP arena so that blocks can be allocated from
 107  *              it.
 108  */
 109
 110 extern void mparena_create(mparena */*a*/);
 111
 112 #define MPARENA_INIT { 0, 0, &mparena_defaultops }
 113
 114 /* --- @mparena_setops@ --- *
 115  *
 116  * Arguments:   @mparena *a@ = pointer to arena block
 117  *              @mparena_ops *ops@ = pointer to operations block or null
 118  *
 119  * Returns:     The previous operations block.
 120  *
 121  * Use:         Sets or queries the operations attached to an arena.
 122  */
 123
 124 extern mparena_ops *mparena_setops(mparena */*a*/, mparena_ops */*ops*/);
 125
 126 /* --- @mparena_destroy@ --- *
 127  *
 128  * Arguments:   @mparena *a@ = pointer to arena block
 129  *
 130  * Returns:     ---
 131  *
 132  * Use:         Frees an MP arena, and all the vectors held within it.  The
 133  *              blocks which are currently allocated can be freed into some
 134  *              other arena.
 135  */
 136
 137 extern void mparena_destroy(mparena */*a*/);
 138
 139 /* --- @mparena_count@ --- *
 140  *
 141  * Arguments:   @mparena *a@ = pointer to arena block
 142  *
 143  * Returns:     Number of allocated blocks from this arena.
 144  *
 145  * Use:         Reports the number of blocks allocated from the arena and not
 146  *              yet freed.
 147  */
 148
 149 extern unsigned mparena_count(mparena */*a*/);
 150
 151 /* --- @mpalloc@ --- *
 152  *
 153  * Arguments:   @mparena *a@ = pointer to arena block
 154  *              @size_t sz@ = number of digits required
 155  *
 156  * Returns:     Pointer to a suitably sized block.
 157  *
 158  * Use:         Allocates a lump of data suitable for use as an array of MP
 159  *              digits.
 160  */
 161
 162 extern mpw *mpalloc(mparena */*a*/, size_t /*sz*/);
 163
 164 /* --- @mpfree@ --- *
 165  *
 166  * Arguments:   @mparena *a@ = pointer to arena block
 167  *              @mpw *v@ = pointer to allocated vector
 168  *
 169  * Returns:     ---
 170  *
 171  * Use:         Returns an MP vector to an arena.
 172  */
 173
 174 extern void mpfree(mparena */*a*/, mpw */*v*/);
 175
 176 /*----- That's all, folks -------------------------------------------------*/
 177
 178 #ifdef __cplusplus
 179   }
 180 #endif
 181
 182 #endif