exec/mempool.c

   1 /*
   2  * Copyright (c) 2003-2004 MontaVista Software, Inc.
   3  *
   4  * All rights reserved.
   5  *
   6  * Author: Steven Dake (sdake@mvista.com)
   7  *
   8  * This software licensed under BSD license, the text of which follows:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are met:
  12  *
  13  * - Redistributions of source code must retain the above copyright notice,
  14  *   this list of conditions and the following disclaimer.
  15  * - Redistributions in binary form must reproduce the above copyright notice,
  16  *   this list of conditions and the following disclaimer in the documentation
  17  *   and/or other materials provided with the distribution.
  18  * - Neither the name of the MontaVista Software, Inc. nor the names of its
  19  *   contributors may be used to endorse or promote products derived from this
  20  *   software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  32  * THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <errno.h>
  38
  39 #include "../include/list.h"
  40 #include "mempool.h"
  41
  42 int mempool_bytes = 0;
  43
  44 struct mempool_list {
  45         struct list_head free;
  46         short free_entries;
  47         short used_entries;
  48 };
  49
  50 struct mempool_entry {
  51         struct list_head list;
  52         int mempool_entry;
  53         char mem[0];
  54 };
  55
  56 struct mempool_list mempool_group[MEMPOOL_GROUP_SIZE];
  57
  58 #ifdef MEMPOOL_ON
  59 int mempool_init (int pool_sizes[MEMPOOL_GROUP_SIZE])
  60 {
  61         int i, j;
  62         struct mempool_entry *entry;
  63         void *mempool;
  64         char *p;
  65         int bytes_to_alloc;
  66
  67         for (i = 0; i < MEMPOOL_GROUP_SIZE; i++) {
  68                 for (j = 0; j < pool_sizes[i]; j++) {
  69                         bytes_to_alloc = sizeof (struct mempool_entry) + (1 << i) + 3;
  70                         bytes_to_alloc &= 0xFFFFFFFC;
  71                         mempool_bytes += bytes_to_alloc;
  72                 }
  73         }
  74         mempool = malloc (mempool_bytes);
  75         if (mempool == 0) {
  76                 return (ENOMEM);
  77         }
  78         memset (mempool, 0, mempool_bytes);
  79
  80         for (p = (char *)mempool, i = 0; i < MEMPOOL_GROUP_SIZE; i++) {
  81                 list_init (&mempool_group[i].free);
  82                 mempool_group[i].free_entries = pool_sizes[i];
  83                 mempool_group[i].used_entries = 0;
  84
  85                 for (j = 0; j < pool_sizes[i]; j++) {
  86                         entry = (struct mempool_entry *)p;
  87
  88                         entry->mempool_entry = i;
  89                         list_add (&entry->list, &mempool_group[i].free);
  90
  91                         bytes_to_alloc = sizeof (struct mempool_entry) + (1 << i) + 3;
  92                         bytes_to_alloc &= 0xFFFFFFFC;
  93                         p += bytes_to_alloc;
  94                 }
  95         }
  96
  97         return (0);
  98 }
  99
 100 void *mempool_malloc (size_t size)
 101 {
 102         struct mempool_entry *mempool_entry;
 103         int i;
 104 #ifdef DEBUG
 105         int first = 0;
 106
 107         int stats_inuse[MEMPOOL_GROUP_SIZE];
 108         int stats_avail[MEMPOOL_GROUP_SIZE];
 109         int stats_memoryused[MEMPOOL_GROUP_SIZE];
 110 #endif
 111
 112         for (i = 0; i < MEMPOOL_GROUP_SIZE; i++) {
 113 #ifdef DEBUG
 114                 if (((i << 1) >= size) && first == 0) {
 115                         first = i;
 116                 }
 117 #endif
 118
 119                 if (((1 << i) >= size) &&
 120                         mempool_group[i].free_entries) {
 121
 122                         mempool_group[i].used_entries += 1;
 123                         mempool_group[i].free_entries -= 1;
 124                         mempool_entry = list_entry (mempool_group[i].free.next,
 125                                 struct mempool_entry, list);
 126                         list_del (mempool_group[i].free.next);
 127                         return (&mempool_entry->mem);
 128                 }
 129         }
 130
 131 #ifdef DEBUG
 132         mempool_getstats (stats_inuse, stats_avail, stats_memoryused);
 133         printf ("MEMORY POOLS first %d %d:\n", first, size);
 134         for (i = 0; i < MEMPOOL_GROUP_SIZE; i++) {
 135         printf ("order %d size %d inuse %d avail %d memory used %d\n",
 136                 i, 1<<i, stats_inuse[i], stats_avail[i], stats_memoryused[i]);
 137         }
 138 #endif
 139         return (0);
 140 }
 141
 142 void mempool_free (void *ptr) {
 143         struct mempool_entry *mempool_entry;
 144
 145         mempool_entry = ((struct mempool_entry *)((unsigned long)(ptr) - (unsigned long)(&((struct mempool_entry *)0)->mem)));
 146
 147         mempool_group[mempool_entry->mempool_entry].free_entries += 1;
 148         mempool_group[mempool_entry->mempool_entry].used_entries -= 1;
 149         list_add (&mempool_entry->list, &mempool_group[mempool_entry->mempool_entry].free);
 150 }
 151
 152 void *mempool_realloc (void *ptr, size_t size) {
 153         struct mempool_entry *mempool_entry;
 154         void *new_ptr;
 155
 156         mempool_entry = ((struct mempool_entry *)((unsigned long)(ptr) - (unsigned long)(&((struct mempool_entry *)0)->mem)));
 157
 158         if (ptr == 0 || (1 << mempool_entry->mempool_entry) < size) {
 159                 /*
 160                  * Must grow allocated block, copy memory, free old block
 161                  */
 162                 new_ptr = (void *)mempool_malloc (size);
 163                 if (new_ptr == 0) {
 164                         return (0);
 165                 }
 166                 if (ptr) {
 167                         memcpy (new_ptr, ptr, (1 << mempool_entry->mempool_entry));
 168                         mempool_free (ptr);
 169                 }
 170                 ptr = new_ptr;
 171         }
 172
 173         return (ptr);
 174 }
 175
 176 char *mempool_strdup (const char *s)
 177 {
 178         char *mem;
 179
 180         mem = mempool_malloc (strlen (s));
 181         strcpy (mem, s);
 182         return (mem);
 183 }
 184
 185 void mempool_getstats (
 186         int stats_inuse[MEMPOOL_GROUP_SIZE],
 187         int stats_avail[MEMPOOL_GROUP_SIZE],
 188         int stats_memoryused[MEMPOOL_GROUP_SIZE])
 189 {
 190         int i;
 191
 192         for (i = 0; i < MEMPOOL_GROUP_SIZE; i++) {
 193                 stats_inuse[i] = mempool_group[i].used_entries;
 194                 stats_avail[i] = mempool_group[i].free_entries;
 195                 stats_memoryused[i] = (mempool_group[i].used_entries + mempool_group[i].free_entries) * (sizeof (struct mempool_entry) + (1<<i));
 196         }
 197 }
 198 #else /* MEMPOOL_ON NOT SET */
 199 int mempool_init (int pool_sizes[MEMPOOL_GROUP_SIZE]) {
 200         return (0);
 201 }
 202
 203 void *mempool_malloc (size_t size) {
 204         return (malloc (size));
 205 }
 206 void mempool_free (void *ptr) {
 207         free (ptr);
 208 }
 209
 210 void *mempool_realloc (void *ptr, size_t size) {
 211         return (realloc (ptr, size));
 212 }
 213
 214 char *mempool_strdup (const char *s) {
 215         return (strdup (s));
 216 }
 217 void mempool_getstats (
 218         int stats_inuse[MEMPOOL_GROUP_SIZE],
 219         int stats_avail[MEMPOOL_GROUP_SIZE],
 220         int stats_memoryused[MEMPOOL_GROUP_SIZE]) {
 221
 222         return;
 223 }
 224 #endif