glib/gmem.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  28 #error "Only <glib.h> can be included directly."
  29 #endif
  30
  31 #ifndef __G_MEM_H__
  32 #define __G_MEM_H__
  33
  34 #include <glib/gslice.h>
  35 #include <glib/gtypes.h>
  36
  37 G_BEGIN_DECLS
  38
  39 /**
  40  * GMemVTable:
  41  * @malloc: function to use for allocating memory.
  42  * @realloc: function to use for reallocating memory.
  43  * @free: function to use to free memory.
  44  * @calloc: function to use for allocating zero-filled memory.
  45  * @try_malloc: function to use for allocating memory without a default error handler.
  46  * @try_realloc: function to use for reallocating memory without a default error handler.
  47  *
  48  * A set of functions used to perform memory allocation. The same #GMemVTable must
  49  * be used for all allocations in the same program; a call to g_mem_set_vtable(),
  50  * if it exists, should be prior to any use of GLib.
  51  */
  52 typedef struct _GMemVTable GMemVTable;
  53
  54
  55 #if GLIB_SIZEOF_VOID_P > GLIB_SIZEOF_LONG
  56 /**
  57  * G_MEM_ALIGN:
  58  *
  59  * Indicates the number of bytes to which memory will be aligned on the
  60  * current platform.
  61  */
  62 #  define G_MEM_ALIGN   GLIB_SIZEOF_VOID_P
  63 #else   /* GLIB_SIZEOF_VOID_P <= GLIB_SIZEOF_LONG */
  64 #  define G_MEM_ALIGN   GLIB_SIZEOF_LONG
  65 #endif  /* GLIB_SIZEOF_VOID_P <= GLIB_SIZEOF_LONG */
  66
  67
  68 /* Memory allocation functions
  69  */
  70
  71 void     g_free           (gpointer      mem);
  72
  73 gpointer g_malloc         (gsize         n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  74 gpointer g_malloc0        (gsize         n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  75 gpointer g_realloc        (gpointer      mem,
  76                            gsize         n_bytes) G_GNUC_WARN_UNUSED_RESULT;
  77 gpointer g_try_malloc     (gsize         n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  78 gpointer g_try_malloc0    (gsize         n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  79 gpointer g_try_realloc    (gpointer      mem,
  80                            gsize         n_bytes) G_GNUC_WARN_UNUSED_RESULT;
  81
  82 gpointer g_malloc_n       (gsize         n_blocks,
  83                            gsize         n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2);
  84 gpointer g_malloc0_n      (gsize         n_blocks,
  85                            gsize         n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2);
  86 gpointer g_realloc_n      (gpointer      mem,
  87                            gsize         n_blocks,
  88                            gsize         n_block_bytes) G_GNUC_WARN_UNUSED_RESULT;
  89 gpointer g_try_malloc_n   (gsize         n_blocks,
  90                            gsize         n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2);
  91 gpointer g_try_malloc0_n  (gsize         n_blocks,
  92                            gsize         n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2);
  93 gpointer g_try_realloc_n  (gpointer      mem,
  94                            gsize         n_blocks,
  95                            gsize         n_block_bytes) G_GNUC_WARN_UNUSED_RESULT;
  96
  97
  98 /* Optimise: avoid the call to the (slower) _n function if we can
  99  * determine at compile-time that no overflow happens.
 100  */
 101 #if defined (__GNUC__) && (__GNUC__ >= 2) && defined (__OPTIMIZE__)
 102 #  define _G_NEW(struct_type, n_structs, func) \
 103         (struct_type *) (G_GNUC_EXTENSION ({                    \
 104           gsize __n = (gsize) (n_structs);                      \
 105           gsize __s = sizeof (struct_type);                     \
 106           gpointer __p;                                         \
 107           if (__s == 1)                                         \
 108             __p = g_##func (__n);                               \
 109           else if (__builtin_constant_p (__n) &&                \
 110                    (__s == 0 || __n <= G_MAXSIZE / __s))        \
 111             __p = g_##func (__n * __s);                         \
 112           else                                                  \
 113             __p = g_##func##_n (__n, __s);                      \
 114           __p;                                                  \
 115         }))
 116 #  define _G_RENEW(struct_type, mem, n_structs, func) \
 117         (struct_type *) (G_GNUC_EXTENSION ({                    \
 118           gsize __n = (gsize) (n_structs);                      \
 119           gsize __s = sizeof (struct_type);                     \
 120           gpointer __p = (gpointer) (mem);                      \
 121           if (__s == 1)                                         \
 122             __p = g_##func (__p, __n);                          \
 123           else if (__builtin_constant_p (__n) &&                \
 124                    (__s == 0 || __n <= G_MAXSIZE / __s))        \
 125             __p = g_##func (__p, __n * __s);                    \
 126           else                                                  \
 127             __p = g_##func##_n (__p, __n, __s);                 \
 128           __p;                                                  \
 129         }))
 130
 131 #else
 132
 133 /* Unoptimised version: always call the _n() function. */
 134
 135 #define _G_NEW(struct_type, n_structs, func) \
 136         ((struct_type *) g_##func##_n ((n_structs), sizeof (struct_type)))
 137 #define _G_RENEW(struct_type, mem, n_structs, func) \
 138         ((struct_type *) g_##func##_n (mem, (n_structs), sizeof (struct_type)))
 139
 140 #endif
 141
 142 /**
 143  * g_new:
 144  * @struct_type: the type of the elements to allocate
 145  * @n_structs: the number of elements to allocate
 146  *
 147  * Allocates @n_structs elements of type @struct_type.
 148  * The returned pointer is cast to a pointer to the given type.
 149  * If @n_structs is 0 it returns %NULL.
 150  * Care is taken to avoid overflow when calculating the size of the allocated block.
 151  *
 152  * Since the returned pointer is already casted to the right type,
 153  * it is normally unnecessary to cast it explicitly, and doing
 154  * so might hide memory allocation errors.
 155  *
 156  * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type
 157  */
 158 #define g_new(struct_type, n_structs)                   _G_NEW (struct_type, n_structs, malloc)
 159 /**
 160  * g_new0:
 161  * @struct_type: the type of the elements to allocate.
 162  * @n_structs: the number of elements to allocate.
 163  *
 164  * Allocates @n_structs elements of type @struct_type, initialized to 0's.
 165  * The returned pointer is cast to a pointer to the given type.
 166  * If @n_structs is 0 it returns %NULL.
 167  * Care is taken to avoid overflow when calculating the size of the allocated block.
 168  *
 169  * Since the returned pointer is already casted to the right type,
 170  * it is normally unnecessary to cast it explicitly, and doing
 171  * so might hide memory allocation errors.
 172  *
 173  * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type.
 174  */
 175 #define g_new0(struct_type, n_structs)                  _G_NEW (struct_type, n_structs, malloc0)
 176 /**
 177  * g_renew:
 178  * @struct_type: the type of the elements to allocate
 179  * @mem: the currently allocated memory
 180  * @n_structs: the number of elements to allocate
 181  *
 182  * Reallocates the memory pointed to by @mem, so that it now has space for
 183  * @n_structs elements of type @struct_type. It returns the new address of
 184  * the memory, which may have been moved.
 185  * Care is taken to avoid overflow when calculating the size of the allocated block.
 186  *
 187  * Returns: a pointer to the new allocated memory, cast to a pointer to @struct_type
 188  */
 189 #define g_renew(struct_type, mem, n_structs)            _G_RENEW (struct_type, mem, n_structs, realloc)
 190 /**
 191  * g_try_new:
 192  * @struct_type: the type of the elements to allocate
 193  * @n_structs: the number of elements to allocate
 194  *
 195  * Attempts to allocate @n_structs elements of type @struct_type, and returns
 196  * %NULL on failure. Contrast with g_new(), which aborts the program on failure.
 197  * The returned pointer is cast to a pointer to the given type.
 198  * The function returns %NULL when @n_structs is 0 of if an overflow occurs.
 199  *
 200  * Since: 2.8
 201  * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type
 202  */
 203 #define g_try_new(struct_type, n_structs)               _G_NEW (struct_type, n_structs, try_malloc)
 204 /**
 205  * g_try_new0:
 206  * @struct_type: the type of the elements to allocate
 207  * @n_structs: the number of elements to allocate
 208  *
 209  * Attempts to allocate @n_structs elements of type @struct_type, initialized
 210  * to 0's, and returns %NULL on failure. Contrast with g_new0(), which aborts
 211  * the program on failure.
 212  * The returned pointer is cast to a pointer to the given type.
 213  * The function returns %NULL when @n_structs is 0 of if an overflow occurs.
 214  *
 215  * Since: 2.8
 216  * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type
 217  */
 218 #define g_try_new0(struct_type, n_structs)              _G_NEW (struct_type, n_structs, try_malloc0)
 219 /**
 220  * g_try_renew:
 221  * @struct_type: the type of the elements to allocate
 222  * @mem: the currently allocated memory
 223  * @n_structs: the number of elements to allocate
 224  *
 225  * Attempts to reallocate the memory pointed to by @mem, so that it now has
 226  * space for @n_structs elements of type @struct_type, and returns %NULL on
 227  * failure. Contrast with g_renew(), which aborts the program on failure.
 228  * It returns the new address of the memory, which may have been moved.
 229  * The function returns %NULL if an overflow occurs.
 230  *
 231  * Since: 2.8
 232  * Returns: a pointer to the new allocated memory, cast to a pointer to @struct_type
 233  */
 234 #define g_try_renew(struct_type, mem, n_structs)        _G_RENEW (struct_type, mem, n_structs, try_realloc)
 235
 236
 237 /* Memory allocation virtualization for debugging purposes
 238  * g_mem_set_vtable() has to be the very first GLib function called
 239  * if being used
 240  */
 241 struct _GMemVTable {
 242   gpointer (*malloc)      (gsize    n_bytes);
 243   gpointer (*realloc)     (gpointer mem,
 244                            gsize    n_bytes);
 245   void     (*free)        (gpointer mem);
 246   /* optional; set to NULL if not used ! */
 247   gpointer (*calloc)      (gsize    n_blocks,
 248                            gsize    n_block_bytes);
 249   gpointer (*try_malloc)  (gsize    n_bytes);
 250   gpointer (*try_realloc) (gpointer mem,
 251                            gsize    n_bytes);
 252 };
 253 void     g_mem_set_vtable (GMemVTable   *vtable);
 254 gboolean g_mem_is_system_malloc (void);
 255
 256 GLIB_VAR gboolean g_mem_gc_friendly;
 257
 258 /* Memory profiler and checker, has to be enabled via g_mem_set_vtable()
 259  */
 260 GLIB_VAR GMemVTable     *glib_mem_profiler_table;
 261 void    g_mem_profile   (void);
 262
 263
 264 /* deprecated memchunks and allocators */
 265 #if !defined (G_DISABLE_DEPRECATED) || defined (GTK_COMPILATION) || defined (GDK_COMPILATION)
 266 typedef struct _GAllocator GAllocator;
 267 typedef struct _GMemChunk  GMemChunk;
 268 #define g_mem_chunk_create(type, pre_alloc, alloc_type) ( \
 269   g_mem_chunk_new (#type " mem chunks (" #pre_alloc ")", \
 270                    sizeof (type), \
 271                    sizeof (type) * (pre_alloc), \
 272                    (alloc_type)) \
 273 )
 274 #define g_chunk_new(type, chunk)        ( \
 275   (type *) g_mem_chunk_alloc (chunk) \
 276 )
 277 #define g_chunk_new0(type, chunk)       ( \
 278   (type *) g_mem_chunk_alloc0 (chunk) \
 279 )
 280 #define g_chunk_free(mem, mem_chunk)    G_STMT_START { \
 281   g_mem_chunk_free ((mem_chunk), (mem)); \
 282 } G_STMT_END
 283 #define G_ALLOC_ONLY      1
 284 #define G_ALLOC_AND_FREE  2
 285 GMemChunk* g_mem_chunk_new     (const gchar *name,
 286                                 gint         atom_size,
 287                                 gsize        area_size,
 288                                 gint         type);
 289 void       g_mem_chunk_destroy (GMemChunk   *mem_chunk);
 290 gpointer   g_mem_chunk_alloc   (GMemChunk   *mem_chunk);
 291 gpointer   g_mem_chunk_alloc0  (GMemChunk   *mem_chunk);
 292 void       g_mem_chunk_free    (GMemChunk   *mem_chunk,
 293                                 gpointer     mem);
 294 void       g_mem_chunk_clean   (GMemChunk   *mem_chunk);
 295 void       g_mem_chunk_reset   (GMemChunk   *mem_chunk);
 296 void       g_mem_chunk_print   (GMemChunk   *mem_chunk);
 297 void       g_mem_chunk_info    (void);
 298 void       g_blow_chunks       (void);
 299 GAllocator*g_allocator_new     (const gchar  *name,
 300                                 guint         n_preallocs);
 301 void       g_allocator_free    (GAllocator   *allocator);
 302 #define G_ALLOCATOR_LIST       (1)
 303 #define G_ALLOCATOR_SLIST      (2)
 304 #define G_ALLOCATOR_NODE       (3)
 305 #endif /* G_DISABLE_DEPRECATED */
 306
 307 G_END_DECLS
 308
 309 #endif /* __G_MEM_H__ */