malloc/malloc.h

   1 /* Prototypes and definition for malloc implementation.
   2    Copyright (C) 1996-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _MALLOC_H
  20 #define _MALLOC_H 1
  21
  22 #include <features.h>
  23 #include <stddef.h>
  24 #include <stdio.h>
  25
  26 #ifdef _LIBC
  27 # define __MALLOC_HOOK_VOLATILE
  28 # define __MALLOC_DEPRECATED
  29 #else
  30 # define __MALLOC_HOOK_VOLATILE volatile
  31 # define __MALLOC_DEPRECATED __attribute_deprecated__
  32 #endif
  33
  34
  35 __BEGIN_DECLS
  36
  37 /* Allocate SIZE bytes of memory.  */
  38 extern void *malloc (size_t __size) __THROW __attribute_malloc__ __wur;
  39
  40 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
  41 extern void *calloc (size_t __nmemb, size_t __size)
  42 __THROW __attribute_malloc__ __wur;
  43
  44 /* Re-allocate the previously allocated block in __ptr, making the new
  45    block SIZE bytes long.  */
  46 /* __attribute_malloc__ is not used, because if realloc returns
  47    the same pointer that was passed to it, aliasing needs to be allowed
  48    between objects pointed by the old and new pointers.  */
  49 extern void *realloc (void *__ptr, size_t __size)
  50 __THROW __attribute_warn_unused_result__;
  51
  52 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
  53 extern void free (void *__ptr) __THROW;
  54
  55 /* Allocate SIZE bytes allocated to ALIGNMENT bytes.  */
  56 extern void *memalign (size_t __alignment, size_t __size)
  57 __THROW __attribute_malloc__ __wur;
  58
  59 /* Allocate SIZE bytes on a page boundary.  */
  60 extern void *valloc (size_t __size) __THROW __attribute_malloc__ __wur;
  61
  62 /* Equivalent to valloc(minimum-page-that-holds(n)), that is, round up
  63    __size to nearest pagesize. */
  64 extern void *pvalloc (size_t __size) __THROW __attribute_malloc__ __wur;
  65
  66 /* Underlying allocation function; successive calls should return
  67    contiguous pieces of memory.  */
  68 extern void *(*__morecore) (ptrdiff_t __size);
  69
  70 /* Default value of `__morecore'.  */
  71 extern void *__default_morecore (ptrdiff_t __size)
  72 __THROW __attribute_malloc__;
  73
  74 /* SVID2/XPG mallinfo structure */
  75
  76 struct mallinfo
  77 {
  78   int arena;    /* non-mmapped space allocated from system */
  79   int ordblks;  /* number of free chunks */
  80   int smblks;   /* number of fastbin blocks */
  81   int hblks;    /* number of mmapped regions */
  82   int hblkhd;   /* space in mmapped regions */
  83   int usmblks;  /* always 0, preserved for backwards compatibility */
  84   int fsmblks;  /* space available in freed fastbin blocks */
  85   int uordblks; /* total allocated space */
  86   int fordblks; /* total free space */
  87   int keepcost; /* top-most, releasable (via malloc_trim) space */
  88 };
  89
  90 /* Returns a copy of the updated current mallinfo. */
  91 extern struct mallinfo mallinfo (void) __THROW;
  92
  93 /* SVID2/XPG mallopt options */
  94 #ifndef M_MXFAST
  95 # define M_MXFAST  1    /* maximum request size for "fastbins" */
  96 #endif
  97 #ifndef M_NLBLKS
  98 # define M_NLBLKS  2    /* UNUSED in this malloc */
  99 #endif
 100 #ifndef M_GRAIN
 101 # define M_GRAIN   3    /* UNUSED in this malloc */
 102 #endif
 103 #ifndef M_KEEP
 104 # define M_KEEP    4    /* UNUSED in this malloc */
 105 #endif
 106
 107 /* mallopt options that actually do something */
 108 #define M_TRIM_THRESHOLD    -1
 109 #define M_TOP_PAD           -2
 110 #define M_MMAP_THRESHOLD    -3
 111 #define M_MMAP_MAX          -4
 112 #define M_CHECK_ACTION      -5
 113 #define M_PERTURB           -6
 114 #define M_ARENA_TEST        -7
 115 #define M_ARENA_MAX         -8
 116
 117 /* General SVID/XPG interface to tunable parameters. */
 118 extern int mallopt (int __param, int __val) __THROW;
 119
 120 /* Release all but __pad bytes of freed top-most memory back to the
 121    system. Return 1 if successful, else 0. */
 122 extern int malloc_trim (size_t __pad) __THROW;
 123
 124 /* Report the number of usable allocated bytes associated with allocated
 125    chunk __ptr. */
 126 extern size_t malloc_usable_size (void *__ptr) __THROW;
 127
 128 /* Prints brief summary statistics on stderr. */
 129 extern void malloc_stats (void) __THROW;
 130
 131 /* Output information about state of allocator to stream FP.  */
 132 extern int malloc_info (int __options, FILE *__fp) __THROW;
 133
 134 /* Hooks for debugging and user-defined versions. */
 135 extern void (*__MALLOC_HOOK_VOLATILE __free_hook) (void *__ptr,
 136                                                    const void *)
 137 __MALLOC_DEPRECATED;
 138 extern void *(*__MALLOC_HOOK_VOLATILE __malloc_hook)(size_t __size,
 139                                                      const void *)
 140 __MALLOC_DEPRECATED;
 141 extern void *(*__MALLOC_HOOK_VOLATILE __realloc_hook)(void *__ptr,
 142                                                       size_t __size,
 143                                                       const void *)
 144 __MALLOC_DEPRECATED;
 145 extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
 146                                                        size_t __size,
 147                                                        const void *)
 148 __MALLOC_DEPRECATED;
 149 extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void);
 150
 151 /* Activate a standard set of debugging hooks. */
 152 extern void __malloc_check_init (void) __THROW __MALLOC_DEPRECATED;
 153
 154
 155 __END_DECLS
 156 #endif /* malloc.h */