glib/gslice.h

   1 /* GLIB sliced memory - fast threaded memory chunk allocator
   2  * Copyright (C) 2005 Tim Janik
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-or-later
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef __G_SLICE_H__
  21 #define __G_SLICE_H__
  22
  23 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  24 #error "Only <glib.h> can be included directly."
  25 #endif
  26
  27 #include <glib/gtypes.h>
  28 #include <string.h>
  29
  30 G_BEGIN_DECLS
  31
  32 /* slices - fast allocation/release of small memory blocks
  33  */
  34 GLIB_AVAILABLE_IN_ALL
  35 gpointer g_slice_alloc                  (gsize         block_size) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  36 GLIB_AVAILABLE_IN_ALL
  37 gpointer g_slice_alloc0                 (gsize         block_size) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1);
  38 GLIB_AVAILABLE_IN_ALL
  39 gpointer g_slice_copy                   (gsize         block_size,
  40                                          gconstpointer mem_block) G_GNUC_ALLOC_SIZE(1);
  41 GLIB_AVAILABLE_IN_ALL
  42 void     g_slice_free1                  (gsize         block_size,
  43                                          gpointer      mem_block);
  44 GLIB_AVAILABLE_IN_ALL
  45 void     g_slice_free_chain_with_offset (gsize         block_size,
  46                                          gpointer      mem_chain,
  47                                          gsize         next_offset);
  48 #define  g_slice_new(type)      ((type*) g_slice_alloc (sizeof (type)))
  49
  50 /* Allow the compiler to inline memset(). Since the size is a constant, this
  51  * can significantly improve performance. */
  52 #if defined (__GNUC__) && (__GNUC__ >= 2) && defined (__OPTIMIZE__)
  53 #  define g_slice_new0(type)                                    \
  54   (type *) (G_GNUC_EXTENSION ({                                 \
  55     gsize __s = sizeof (type);                                  \
  56     gpointer __p;                                               \
  57     __p = g_slice_alloc (__s);                                  \
  58     memset (__p, 0, __s);                                       \
  59     __p;                                                        \
  60   }))
  61 #else
  62 #  define g_slice_new0(type)    ((type*) g_slice_alloc0 (sizeof (type)))
  63 #endif
  64
  65 /* MemoryBlockType *
  66  *       g_slice_dup                    (MemoryBlockType,
  67  *                                       MemoryBlockType *mem_block);
  68  *       g_slice_free                   (MemoryBlockType,
  69  *                                       MemoryBlockType *mem_block);
  70  *       g_slice_free_chain             (MemoryBlockType,
  71  *                                       MemoryBlockType *first_chain_block,
  72  *                                       memory_block_next_field);
  73  * pseudo prototypes for the macro
  74  * definitions following below.
  75  */
  76
  77 /* we go through extra hoops to ensure type safety */
  78 #define g_slice_dup(type, mem)                                  \
  79   (1 ? (type*) g_slice_copy (sizeof (type), (mem))              \
  80      : ((void) ((type*) 0 == (mem)), (type*) 0))
  81 #define g_slice_free(type, mem)                                 \
  82 G_STMT_START {                                                  \
  83   if (1) g_slice_free1 (sizeof (type), (mem));                  \
  84   else   (void) ((type*) 0 == (mem));                           \
  85 } G_STMT_END
  86 #define g_slice_free_chain(type, mem_chain, next)               \
  87 G_STMT_START {                                                  \
  88   if (1) g_slice_free_chain_with_offset (sizeof (type),         \
  89                  (mem_chain), G_STRUCT_OFFSET (type, next));    \
  90   else   (void) ((type*) 0 == (mem_chain));                     \
  91 } G_STMT_END
  92
  93 /* --- internal debugging API --- */
  94 typedef enum {
  95   G_SLICE_CONFIG_ALWAYS_MALLOC = 1,
  96   G_SLICE_CONFIG_BYPASS_MAGAZINES,
  97   G_SLICE_CONFIG_WORKING_SET_MSECS,
  98   G_SLICE_CONFIG_COLOR_INCREMENT,
  99   G_SLICE_CONFIG_CHUNK_SIZES,
 100   G_SLICE_CONFIG_CONTENTION_COUNTER
 101 } GSliceConfig;
 102
 103 GLIB_DEPRECATED_IN_2_34
 104 void     g_slice_set_config        (GSliceConfig ckey, gint64 value);
 105 GLIB_DEPRECATED_IN_2_34
 106 gint64   g_slice_get_config        (GSliceConfig ckey);
 107 GLIB_DEPRECATED_IN_2_34
 108 gint64*  g_slice_get_config_state  (GSliceConfig ckey, gint64 address, guint *n_values);
 109
 110 #ifdef G_ENABLE_DEBUG
 111 GLIB_AVAILABLE_IN_ALL
 112 void     g_slice_debug_tree_statistics (void);
 113 #endif
 114
 115 G_END_DECLS
 116
 117 #endif /* __G_SLICE_H__ */