lib/libstand/zalloc_malloc.c

   1 /*
   2  * This module derived from code donated to the FreeBSD Project by
   3  * Matthew Dillon <dillon@backplane.com>
   4  *
   5  * Copyright (c) 1998 The FreeBSD Project
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/lib/libstand/zalloc_malloc.c,v 1.5 1999/08/28 00:05:35 peter Exp $
  30  * $DragonFly: src/lib/libstand/zalloc_malloc.c,v 1.3 2005/03/13 15:10:03 swildner Exp $
  31  */
  32
  33 /*
  34  * MALLOC.C - malloc equivalent, runs on top of zalloc and uses sbrk
  35  */
  36
  37 #include "zalloc_defs.h"
  38
  39 static MemPool  MallocPool;
  40
  41 #ifdef DMALLOCDEBUG
  42 static int MallocMax;
  43 static int MallocCount;
  44
  45 void mallocstats(void);
  46 #endif
  47
  48 #ifdef malloc
  49 #undef malloc
  50 #undef free
  51 #endif
  52
  53 void *
  54 malloc(size_t bytes)
  55 {
  56     Guard *res;
  57
  58 #ifdef USEENDGUARD
  59     bytes += MALLOCALIGN + 1;
  60 #else
  61     bytes += MALLOCALIGN;
  62 #endif
  63
  64     while ((res = znalloc(&MallocPool, bytes)) == NULL) {
  65         int incr = (bytes + BLKEXTENDMASK) & ~BLKEXTENDMASK;
  66         char *base;
  67
  68         if ((base = sbrk(incr)) == (char *)-1)
  69             return(NULL);
  70         zextendPool(&MallocPool, base, incr);
  71         zfree(&MallocPool, base, incr);
  72     }
  73 #ifdef DMALLOCDEBUG
  74     if (++MallocCount > MallocMax)
  75         MallocMax = MallocCount;
  76 #endif
  77 #ifdef USEGUARD
  78     res->ga_Magic = GAMAGIC;
  79 #endif
  80     res->ga_Bytes = bytes;
  81 #ifdef USEENDGUARD
  82     *((char *)res + bytes - 1) = -2;
  83 #endif
  84     return((char *)res + MALLOCALIGN);
  85 }
  86
  87 void
  88 free(void *ptr)
  89 {
  90     size_t bytes;
  91
  92     if (ptr != NULL) {
  93         Guard *res = (void *)((char *)ptr - MALLOCALIGN);
  94
  95 #ifdef USEGUARD
  96         if (res->ga_Magic != GAMAGIC)
  97             panic("free: guard1x fail @ %p", ptr);
  98         res->ga_Magic = -1;
  99 #endif
 100 #ifdef USEENDGUARD
 101         if (*((char *)res + res->ga_Bytes - 1) != -2) {
 102             panic("free: guard2 fail @ %p + %zu %d/-2",
 103                   ptr,
 104                   res->ga_Bytes - MALLOCALIGN - 1,
 105                   *((char *)res + res->ga_Bytes - 1));
 106         }
 107         *((char *)res + res->ga_Bytes - 1) = -1;
 108 #endif
 109
 110         bytes = res->ga_Bytes;
 111         zfree(&MallocPool, res, bytes);
 112 #ifdef DMALLOCDEBUG
 113         --MallocCount;
 114 #endif
 115     }
 116 }
 117
 118
 119 void *
 120 calloc(size_t n1, size_t n2)
 121 {
 122     uintptr_t bytes = (uintptr_t)n1 * (uintptr_t)n2;
 123     void *res;
 124
 125     if ((res = malloc(bytes)) != NULL) {
 126         bzero(res, bytes);
 127     }
 128     return(res);
 129 }
 130
 131 /*
 132  * realloc() - I could be fancier here and free the old buffer before
 133  *             allocating the new one (saving potential fragmentation
 134  *             and potential buffer copies).  But I don't bother.
 135  */
 136
 137 void *
 138 realloc(void *ptr, size_t size)
 139 {
 140     void *res;
 141     size_t old;
 142
 143     if ((res = malloc(size)) != NULL) {
 144         if (ptr) {
 145             old = *(size_t *)((char *)ptr - MALLOCALIGN) - MALLOCALIGN;
 146 #ifdef USEENDGUARD
 147             --old;
 148 #endif
 149             if (old < size)
 150                 bcopy(ptr, res, old);
 151             else
 152                 bcopy(ptr, res, size);
 153             free(ptr);
 154         } else {
 155 #ifdef DMALLOCDEBUG
 156 #ifdef EXITSTATS
 157             if (DidAtExit == 0) {
 158                 DidAtExit = 1;
 159                 atexit(mallocstats);
 160             }
 161 #endif
 162 #endif
 163         }
 164     }
 165     return(res);
 166 }
 167
 168 void *
 169 reallocf(void *ptr, size_t size)
 170 {
 171     void *res;
 172
 173     if ((res = realloc(ptr, size)) == NULL)
 174         free(ptr);
 175     return(res);
 176 }
 177
 178 #ifdef DMALLOCDEBUG
 179
 180 void
 181 mallocstats(void)
 182 {
 183     printf("Active Allocations: %d/%d\n", MallocCount, MallocMax);
 184 #ifdef ZALLOCDEBUG
 185     zallocstats(&MallocPool);
 186 #endif
 187 }
 188
 189 #endif
 190