mdw@git.distorted.org.uk Git - disorder/blob - lib/mem.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2004, 2005, 2006, 2007 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file lib/mem.c
  21  * @brief Memory management
  22  */
  23
  24 #include <config.h>
  25 #include "types.h"
  26
  27 #if GC
  28 #include <gc.h>
  29 #endif
  30 #include <errno.h>
  31 #include <string.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <assert.h>
  35
  36 #include "mem.h"
  37 #include "log.h"
  38 #include "printf.h"
  39
  40 #include "disorder.h"
  41
  42 /** @brief Allocate and zero out
  43  * @param n Number of bytes to allocate
  44  * @return Pointer to allocated memory,  or 0
  45  */
  46 static void *malloc_and_zero(size_t n) {
  47   void *ptr = malloc(n);
  48
  49   if(ptr) memset(ptr, 0, n);
  50   return ptr;
  51 }
  52
  53 #if GC
  54 static void *(*do_malloc)(size_t) = GC_malloc;
  55 static void *(*do_realloc)(void *, size_t) = GC_realloc;
  56 static void *(*do_malloc_atomic)(size_t) = GC_malloc_atomic;
  57 static void (*do_free)(void *) = GC_free;
  58 #else
  59 static void *(*do_malloc)(size_t) = malloc_and_zero;
  60 static void *(*do_realloc)(void *, size_t) = realloc;
  61 static void *(*do_malloc_atomic)(size_t) = malloc;
  62 static void (*do_free)(void *) = free;
  63 #endif
  64
  65 /** @brief Initialize memory management
  66  *
  67  * Must be called by all programs that use garbage collection.  Define
  68  * @c ${DISORDER_GC} to @c no to suppress use of the collector
  69  * (e.g. for debugging purposes).
  70  */
  71 void mem_init(void) {
  72 #if GC
  73   const char *e;
  74
  75   if(((e = getenv("DISORDER_GC")) && !strcmp(e, "no"))) {
  76     do_malloc = malloc_and_zero;
  77     do_malloc_atomic = malloc;
  78     do_realloc = realloc;
  79     do_free = free;
  80   } else {
  81     GC_init();
  82     assert(GC_all_interior_pointers);
  83   }
  84 #endif
  85 }
  86
  87 /** @brief Allocate memory
  88  * @param n Bytes to allocate
  89  * @return Pointer to allocated memory
  90  *
  91  * Terminates the process on error.  The allocated memory is always
  92  * 0-filled.
  93  */
  94 void *xmalloc(size_t n) {
  95   void *ptr;
  96
  97   if(!(ptr = do_malloc(n)) && n)
  98     fatal(errno, "error allocating memory");
  99   return ptr;
 100 }
 101
 102 /** @brief Reallocate memory
 103  * @param ptr Block to reallocated
 104  * @param n Bytes to allocate
 105  * @return Pointer to allocated memory
 106  *
 107  * Terminates the process on error.  It is NOT guaranteed that any
 108  * additional memory allocated is 0-filled.
 109  */
 110 void *xrealloc(void *ptr, size_t n) {
 111   if(!(ptr = do_realloc(ptr, n)) && n)
 112     fatal(errno, "error allocating memory");
 113   return ptr;
 114 }
 115
 116 /** @brief Allocate memory
 117  * @param count Number of objects to allocate
 118  * @param size Size of one object
 119  * @return Pointer to allocated memory
 120  *
 121  * Terminates the process on error.  The allocated memory is always
 122  * 0-filled.
 123  */
 124 void *xcalloc(size_t count, size_t size) {
 125   if(count > SIZE_MAX / size)
 126     fatal(0, "excessively large calloc");
 127   return xmalloc(count * size);
 128 }
 129
 130 /** @brief Allocate memory
 131  * @param n Bytes to allocate
 132  * @return Pointer to allocated memory
 133  *
 134  * Terminates the process on error.  The allocated memory is not
 135  * guaranteed to be 0-filled and is not suitable for storing pointers
 136  * in.
 137  */
 138 void *xmalloc_noptr(size_t n) {
 139   void *ptr;
 140
 141   if(!(ptr = do_malloc_atomic(n)) && n)
 142     fatal(errno, "error allocating memory");
 143   return ptr;
 144 }
 145
 146 /** @brief Reallocate memory
 147  * @param ptr Block to reallocated
 148  * @param n Bytes to allocate
 149  * @return Pointer to allocated memory
 150  *
 151  * Terminates the processf on error.  It is NOT guaranteed that any
 152  * additional memory allocated is 0-filled.  The block must have been
 153  * allocated with xmalloc_noptr() (or xrealloc_noptr()) initially.
 154  */
 155 void *xrealloc_noptr(void *ptr, size_t n) {
 156   if(ptr == 0)
 157     return xmalloc_noptr(n);
 158   if(!(ptr = do_realloc(ptr, n)) && n)
 159     fatal(errno, "error allocating memory");
 160   return ptr;
 161 }
 162
 163 /** @brief Duplicate a string
 164  * @param s String to copy
 165  * @return New copy of string
 166  *
 167  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 168  */
 169 char *xstrdup(const char *s) {
 170   char *t;
 171
 172   if(!(t = do_malloc_atomic(strlen(s) + 1)))
 173     fatal(errno, "error allocating memory");
 174   return strcpy(t, s);
 175 }
 176
 177 /** @brief Duplicate a prefix of a string
 178  * @param s String to copy
 179  * @param n Prefix of string to copy
 180  * @return New copy of string
 181  *
 182  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 183  * @p n must not exceed the length of the string.
 184  */
 185 char *xstrndup(const char *s, size_t n) {
 186   char *t;
 187
 188   if(!(t = do_malloc_atomic(n + 1)))
 189     fatal(errno, "error allocating memory");
 190   memcpy(t, s, n);
 191   t[n] = 0;
 192   return t;
 193 }
 194
 195 /** @brief Free memory
 196  * @param ptr Block to free or 0
 197  */
 198 void xfree(void *ptr) {
 199   do_free(ptr);
 200 }
 201
 202 /*
 203 Local Variables:
 204 c-basic-offset:2
 205 comment-column:40
 206 End:
 207 */