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 "common.h"
  25
  26 #if GC
  27 #include <gc.h>
  28 #endif
  29 #include <errno.h>
  30
  31 #include "mem.h"
  32 #include "log.h"
  33 #include "printf.h"
  34
  35 #include "disorder.h"
  36
  37 /** @brief Allocate and zero out
  38  * @param n Number of bytes to allocate
  39  * @return Pointer to allocated memory,  or 0
  40  */
  41 static void *malloc_and_zero(size_t n) {
  42   void *ptr = malloc(n);
  43
  44   if(ptr) memset(ptr, 0, n);
  45   return ptr;
  46 }
  47
  48 #if GC
  49 static void *(*do_malloc)(size_t) = GC_malloc;
  50 static void *(*do_realloc)(void *, size_t) = GC_realloc;
  51 static void *(*do_malloc_atomic)(size_t) = GC_malloc_atomic;
  52 static void (*do_free)(void *) = GC_free;
  53 #else
  54 static void *(*do_malloc)(size_t) = malloc_and_zero;
  55 static void *(*do_realloc)(void *, size_t) = realloc;
  56 static void *(*do_malloc_atomic)(size_t) = malloc;
  57 static void (*do_free)(void *) = free;
  58 #endif
  59
  60 /** @brief Initialize memory management
  61  *
  62  * Must be called by all programs that use garbage collection.  Define
  63  * @c ${DISORDER_GC} to @c no to suppress use of the collector
  64  * (e.g. for debugging purposes).
  65  */
  66 void mem_init(void) {
  67 #if GC
  68   const char *e;
  69
  70   if(((e = getenv("DISORDER_GC")) && !strcmp(e, "no"))) {
  71     do_malloc = malloc_and_zero;
  72     do_malloc_atomic = malloc;
  73     do_realloc = realloc;
  74     do_free = free;
  75   } else {
  76     GC_init();
  77     assert(GC_all_interior_pointers);
  78   }
  79 #endif
  80 }
  81
  82 /** @brief Allocate memory
  83  * @param n Bytes to allocate
  84  * @return Pointer to allocated memory
  85  *
  86  * Terminates the process on error.  The allocated memory is always
  87  * 0-filled.
  88  */
  89 void *xmalloc(size_t n) {
  90   void *ptr;
  91
  92   if(!(ptr = do_malloc(n)) && n)
  93     fatal(errno, "error allocating memory");
  94   return ptr;
  95 }
  96
  97 /** @brief Reallocate memory
  98  * @param ptr Block to reallocated
  99  * @param n Bytes to allocate
 100  * @return Pointer to allocated memory
 101  *
 102  * Terminates the process on error.  It is NOT guaranteed that any
 103  * additional memory allocated is 0-filled.
 104  */
 105 void *xrealloc(void *ptr, size_t n) {
 106   if(!(ptr = do_realloc(ptr, n)) && n)
 107     fatal(errno, "error allocating memory");
 108   return ptr;
 109 }
 110
 111 /** @brief Allocate memory
 112  * @param count Number of objects to allocate
 113  * @param size Size of one object
 114  * @return Pointer to allocated memory
 115  *
 116  * Terminates the process on error.  The allocated memory is always
 117  * 0-filled.
 118  */
 119 void *xcalloc(size_t count, size_t size) {
 120   if(count > SIZE_MAX / size)
 121     fatal(0, "excessively large calloc");
 122   return xmalloc(count * size);
 123 }
 124
 125 /** @brief Allocate memory
 126  * @param n Bytes to allocate
 127  * @return Pointer to allocated memory
 128  *
 129  * Terminates the process on error.  The allocated memory is not
 130  * guaranteed to be 0-filled and is not suitable for storing pointers
 131  * in.
 132  */
 133 void *xmalloc_noptr(size_t n) {
 134   void *ptr;
 135
 136   if(!(ptr = do_malloc_atomic(n)) && n)
 137     fatal(errno, "error allocating memory");
 138   return ptr;
 139 }
 140
 141 /** @brief Reallocate memory
 142  * @param ptr Block to reallocated
 143  * @param n Bytes to allocate
 144  * @return Pointer to allocated memory
 145  *
 146  * Terminates the processf on error.  It is NOT guaranteed that any
 147  * additional memory allocated is 0-filled.  The block must have been
 148  * allocated with xmalloc_noptr() (or xrealloc_noptr()) initially.
 149  */
 150 void *xrealloc_noptr(void *ptr, size_t n) {
 151   if(ptr == 0)
 152     return xmalloc_noptr(n);
 153   if(!(ptr = do_realloc(ptr, n)) && n)
 154     fatal(errno, "error allocating memory");
 155   return ptr;
 156 }
 157
 158 /** @brief Duplicate a string
 159  * @param s String to copy
 160  * @return New copy of string
 161  *
 162  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 163  */
 164 char *xstrdup(const char *s) {
 165   char *t;
 166
 167   if(!(t = do_malloc_atomic(strlen(s) + 1)))
 168     fatal(errno, "error allocating memory");
 169   return strcpy(t, s);
 170 }
 171
 172 /** @brief Duplicate a prefix of a string
 173  * @param s String to copy
 174  * @param n Prefix of string to copy
 175  * @return New copy of string
 176  *
 177  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 178  * @p n must not exceed the length of the string.
 179  */
 180 char *xstrndup(const char *s, size_t n) {
 181   char *t;
 182
 183   if(!(t = do_malloc_atomic(n + 1)))
 184     fatal(errno, "error allocating memory");
 185   memcpy(t, s, n);
 186   t[n] = 0;
 187   return t;
 188 }
 189
 190 /** @brief Free memory
 191  * @param ptr Block to free or 0
 192  */
 193 void xfree(void *ptr) {
 194   do_free(ptr);
 195 }
 196
 197 /*
 198 Local Variables:
 199 c-basic-offset:2
 200 comment-column:40
 201 End:
 202 */