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, 2009 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 3 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,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU 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, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/mem.c
  19  * @brief Memory management
  20  */
  21
  22 #include "common.h"
  23
  24 #if GC
  25 #include <gc.h>
  26 #endif
  27 #include <errno.h>
  28
  29 #include "mem.h"
  30 #include "log.h"
  31 #include "printf.h"
  32
  33 #include "disorder.h"
  34
  35 /** @brief Allocate and zero out
  36  * @param n Number of bytes to allocate
  37  * @return Pointer to allocated memory,  or 0
  38  */
  39 static void *malloc_and_zero(size_t n) {
  40   void *ptr = malloc(n);
  41
  42   if(ptr) memset(ptr, 0, n);
  43   return ptr;
  44 }
  45
  46 #if GC
  47 static void *(*do_malloc)(size_t) = GC_malloc;
  48 static void *(*do_realloc)(void *, size_t) = GC_realloc;
  49 static void *(*do_malloc_atomic)(size_t) = GC_malloc_atomic;
  50 static void (*do_free)(void *) = GC_free;
  51 #else
  52 static void *(*do_malloc)(size_t) = malloc_and_zero;
  53 static void *(*do_realloc)(void *, size_t) = realloc;
  54 static void *(*do_malloc_atomic)(size_t) = malloc;
  55 static void (*do_free)(void *) = free;
  56 #endif
  57
  58 /** @brief Initialize memory management
  59  *
  60  * Must be called by all programs that use garbage collection.  Define
  61  * @c ${DISORDER_GC} to @c no to suppress use of the collector
  62  * (e.g. for debugging purposes).
  63  */
  64 void mem_init(void) {
  65 #if GC
  66   const char *e;
  67
  68   if(((e = getenv("DISORDER_GC")) && !strcmp(e, "no"))) {
  69     do_malloc = malloc_and_zero;
  70     do_malloc_atomic = malloc;
  71     do_realloc = realloc;
  72     do_free = free;
  73   } else {
  74     GC_init();
  75 #ifdef HAVE_GC_GET_ALL_INTERIOR_POINTERS
  76     assert(GC_get_all_interior_pointers());
  77 #else
  78     assert(GC_all_interior_pointers);
  79 #endif
  80   }
  81 #endif
  82 }
  83
  84 /** @brief Allocate memory
  85  * @param n Bytes to allocate
  86  * @return Pointer to allocated memory
  87  *
  88  * Terminates the process on error.  The allocated memory is always
  89  * 0-filled.
  90  */
  91 void *xmalloc(size_t n) {
  92   void *ptr;
  93
  94   if(!(ptr = do_malloc(n)) && n)
  95     disorder_fatal(errno, "error allocating memory");
  96   return ptr;
  97 }
  98
  99 /** @brief Reallocate memory
 100  * @param ptr Block to reallocated
 101  * @param n Bytes to allocate
 102  * @return Pointer to allocated memory
 103  *
 104  * Terminates the process on error.  It is NOT guaranteed that any
 105  * additional memory allocated is 0-filled.
 106  */
 107 void *xrealloc(void *ptr, size_t n) {
 108   if(!(ptr = do_realloc(ptr, n)) && n)
 109     disorder_fatal(errno, "error allocating memory");
 110   return ptr;
 111 }
 112
 113 /** @brief Allocate memory
 114  * @param count Number of objects to allocate
 115  * @param size Size of one object
 116  * @return Pointer to allocated memory
 117  *
 118  * Terminates the process on error.  The allocated memory is always
 119  * 0-filled.
 120  */
 121 void *xcalloc(size_t count, size_t size) {
 122   if(count > SIZE_MAX / size)
 123     disorder_fatal(0, "excessively large calloc");
 124   return xmalloc(count * size);
 125 }
 126
 127 /** @brief Allocate memory
 128  * @param n Bytes to allocate
 129  * @return Pointer to allocated memory
 130  *
 131  * Terminates the process on error.  The allocated memory is not
 132  * guaranteed to be 0-filled and is not suitable for storing pointers
 133  * in.
 134  */
 135 void *xmalloc_noptr(size_t n) {
 136   void *ptr;
 137
 138   if(!(ptr = do_malloc_atomic(n)) && n)
 139     disorder_fatal(errno, "error allocating memory");
 140   return ptr;
 141 }
 142
 143 /** @brief Allocate memory
 144  * @param count Number of objects to allocate
 145  * @param size Size of one object
 146  * @return Pointer to allocated memory
 147  *
 148  * Terminates the process on error.  IMPORTANT: the allocated memory is NOT
 149  * 0-filled (unlike @c calloc()).
 150  */
 151 void *xcalloc_noptr(size_t count, size_t size) {
 152   if(count > SIZE_MAX / size)
 153     disorder_fatal(0, "excessively large calloc");
 154   return xmalloc_noptr(count * size);
 155 }
 156
 157 /** @brief Reallocate memory
 158  * @param ptr Block to reallocated
 159  * @param n Bytes to allocate
 160  * @return Pointer to allocated memory
 161  *
 162  * Terminates the processf on error.  It is NOT guaranteed that any
 163  * additional memory allocated is 0-filled.  The block must have been
 164  * allocated with xmalloc_noptr() (or xrealloc_noptr()) initially.
 165  */
 166 void *xrealloc_noptr(void *ptr, size_t n) {
 167   if(ptr == 0)
 168     return xmalloc_noptr(n);
 169   if(!(ptr = do_realloc(ptr, n)) && n)
 170     disorder_fatal(errno, "error allocating memory");
 171   return ptr;
 172 }
 173
 174 /** @brief Duplicate a string
 175  * @param s String to copy
 176  * @return New copy of string
 177  *
 178  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 179  */
 180 char *xstrdup(const char *s) {
 181   char *t;
 182
 183   if(!(t = do_malloc_atomic(strlen(s) + 1)))
 184     disorder_fatal(errno, "error allocating memory");
 185   return strcpy(t, s);
 186 }
 187
 188 /** @brief Duplicate a prefix of a string
 189  * @param s String to copy
 190  * @param n Prefix of string to copy
 191  * @return New copy of string
 192  *
 193  * This uses the equivalent of xmalloc_noptr() to allocate the new string.
 194  * @p n must not exceed the length of the string.
 195  */
 196 char *xstrndup(const char *s, size_t n) {
 197   char *t;
 198
 199   if(!(t = do_malloc_atomic(n + 1)))
 200     disorder_fatal(errno, "error allocating memory");
 201   memcpy(t, s, n);
 202   t[n] = 0;
 203   return t;
 204 }
 205
 206 /** @brief Free memory
 207  * @param ptr Block to free or 0
 208  */
 209 void xfree(void *ptr) {
 210   do_free(ptr);
 211 }
 212
 213 /*
 214 Local Variables:
 215 c-basic-offset:2
 216 comment-column:40
 217 fill-column:79
 218 indent-tabs-mode:nil
 219 End:
 220 */