gnu/lib/libmalloc/malloc.h

   1 /* Declarations for `malloc' and friends.
   2    Copyright 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
   3                   Written May 1989 by Mike Haertel.
   4
   5 This library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 This 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 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with this library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.
  19
  20    The author may be reached (Email) at the address mike@ai.mit.edu,
  21    or (US mail) as Mike Haertel c/o Free Software Foundation.  */
  22
  23 #ifndef _MALLOC_H
  24
  25 #define _MALLOC_H       1
  26
  27 #ifdef _MALLOC_INTERNAL
  28
  29 #ifdef  HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #if     defined(_LIBC) || defined(STDC_HEADERS) || defined(USG)
  34 #include <string.h>
  35 #else
  36 #ifndef memset
  37 #define memset(s, zero, n)      bzero ((s), (n))
  38 #endif
  39 #ifndef memcpy
  40 #define memcpy(d, s, n)         bcopy ((s), (d), (n))
  41 #endif
  42 #ifndef memmove
  43 #define memmove(d, s, n)        bcopy ((s), (d), (n))
  44 #endif
  45 #endif
  46
  47 #if     defined(__GNU_LIBRARY__) || defined(__STDC__)
  48 #include <limits.h>
  49 #else
  50 #define CHAR_BIT        8
  51 #endif
  52
  53 #endif  /* _MALLOC_INTERNAL.  */
  54
  55
  56 #ifdef  __cplusplus
  57 extern "C"
  58 {
  59 #endif
  60
  61 #if defined (__cplusplus) || (defined (__STDC__) && __STDC__)
  62 #ifndef __NetBSD__
  63 #undef  __P
  64 #define __P(args)       args
  65 #else
  66 #include <sys/cdefs.h>
  67 #endif
  68 #undef  __ptr_t
  69 #define __ptr_t         void *
  70 #else /* Not C++ or ANSI C.  */
  71 #undef  __P
  72 #define __P(args)       ()
  73 #undef  const
  74 #define const
  75 #undef  __ptr_t
  76 #define __ptr_t         char *
  77 #endif /* C++ or ANSI C.  */
  78
  79 #ifdef  __STDC__
  80 #include <stddef.h>
  81 #else
  82 #undef  size_t
  83 #define size_t          unsigned int
  84 #undef  ptrdiff_t
  85 #define ptrdiff_t       int
  86 #endif
  87
  88 #ifndef NULL
  89 #define NULL    0
  90 #endif
  91
  92
  93 /* Allocate SIZE bytes of memory.  */
  94 extern __ptr_t malloc __P ((size_t __size));
  95 /* Re-allocate the previously allocated block
  96    in __ptr_t, making the new block SIZE bytes long.  */
  97 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
  98 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
  99 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 100 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 101 extern void free __P ((__ptr_t __ptr));
 102
 103 /* Allocate SIZE bytes allocated to ALIGNMENT bytes.  */
 104 extern __ptr_t memalign __P ((size_t __alignment, size_t __size));
 105
 106 /* Allocate SIZE bytes on a page boundary.  */
 107 extern __ptr_t valloc __P ((size_t __size));
 108
 109
 110 #ifdef _MALLOC_INTERNAL
 111
 112 /* The allocator divides the heap into blocks of fixed size; large
 113    requests receive one or more whole blocks, and small requests
 114    receive a fragment of a block.  Fragment sizes are powers of two,
 115    and all fragments of a block are the same size.  When all the
 116    fragments in a block have been freed, the block itself is freed.  */
 117 #define INT_BIT         (CHAR_BIT * sizeof(int))
 118 #define BLOCKLOG        (INT_BIT > 16 ? 12 : 9)
 119 #define BLOCKSIZE       (1 << BLOCKLOG)
 120 #define BLOCKIFY(SIZE)  (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
 121
 122 /* Determine the amount of memory spanned by the initial heap table
 123    (not an absolute limit).  */
 124 #define HEAP            (INT_BIT > 16 ? 4194304 : 65536)
 125
 126 /* Number of contiguous free blocks allowed to build up at the end of
 127    memory before they will be returned to the system.  */
 128 #define FINAL_FREE_BLOCKS       8
 129
 130 /* Data structure giving per-block information.  */
 131 typedef union
 132   {
 133     /* Heap information for a busy block.  */
 134     struct
 135       {
 136         /* Zero for a large block, or positive giving the
 137            logarithm to the base two of the fragment size.  */
 138         int type;
 139         union
 140           {
 141             struct
 142               {
 143                 size_t nfree;   /* Free fragments in a fragmented block.  */
 144                 size_t first;   /* First free fragment of the block.  */
 145               } frag;
 146             /* Size (in blocks) of a large cluster.  */
 147             size_t size;
 148           } info;
 149       } busy;
 150     /* Heap information for a free block
 151        (that may be the first of a free cluster).  */
 152     struct
 153       {
 154         size_t size;            /* Size (in blocks) of a free cluster.  */
 155         size_t next;            /* Index of next free cluster.  */
 156         size_t prev;            /* Index of previous free cluster.  */
 157       } free;
 158   } malloc_info;
 159
 160 /* Pointer to first block of the heap.  */
 161 extern char *_heapbase;
 162
 163 /* Table indexed by block number giving per-block information.  */
 164 extern malloc_info *_heapinfo;
 165
 166 /* Address to block number and vice versa.  */
 167 #define BLOCK(A)        (((char *) (A) - _heapbase) / BLOCKSIZE + 1)
 168 #define ADDRESS(B)      ((__ptr_t) (((B) - 1) * BLOCKSIZE + _heapbase))
 169
 170 /* Current search index for the heap table.  */
 171 extern size_t _heapindex;
 172
 173 /* Limit of valid info table indices.  */
 174 extern size_t _heaplimit;
 175
 176 /* Doubly linked lists of free fragments.  */
 177 struct list
 178   {
 179     struct list *next;
 180     struct list *prev;
 181   };
 182
 183 /* Free list headers for each fragment size.  */
 184 extern struct list _fraghead[];
 185
 186 /* List of blocks allocated with `memalign' (or `valloc').  */
 187 struct alignlist
 188   {
 189     struct alignlist *next;
 190     __ptr_t aligned;            /* The address that memaligned returned.  */
 191     __ptr_t exact;              /* The address that malloc returned.  */
 192   };
 193 extern struct alignlist *_aligned_blocks;
 194
 195 /* Instrumentation.  */
 196 extern size_t _chunks_used;
 197 extern size_t _bytes_used;
 198 extern size_t _chunks_free;
 199 extern size_t _bytes_free;
 200
 201 /* Internal version of `free' used in `morecore' (malloc.c). */
 202 extern void _free_internal __P ((__ptr_t __ptr));
 203
 204 #endif /* _MALLOC_INTERNAL.  */
 205
 206 /* Underlying allocation function; successive calls should
 207    return contiguous pieces of memory.  */
 208 extern __ptr_t (*__morecore) __P ((ptrdiff_t __size));
 209
 210 /* Default value of `__morecore'.  */
 211 extern __ptr_t __default_morecore __P ((ptrdiff_t __size));
 212
 213 /* If not NULL, this function is called after each time
 214    `__morecore' is called to increase the data size.  */
 215 extern void (*__after_morecore_hook) __P ((void));
 216
 217 /* Nonzero if `malloc' has been called and done its initialization.  */
 218 extern int __malloc_initialized;
 219
 220 /* Hooks for debugging versions.  */
 221 extern void (*__free_hook) __P ((__ptr_t __ptr));
 222 extern __ptr_t (*__malloc_hook) __P ((size_t __size));
 223 extern __ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size));
 224
 225 /* Activate a standard collection of debugging hooks.  */
 226 extern int mcheck __P ((void (*__func) __P ((void))));
 227
 228 /* Activate a standard collection of tracing hooks.  */
 229 extern void mtrace __P ((void));
 230
 231 /* Statistics available to the user.  */
 232 struct mstats
 233   {
 234     size_t bytes_total;         /* Total size of the heap. */
 235     size_t chunks_used;         /* Chunks allocated by the user. */
 236     size_t bytes_used;          /* Byte total of user-allocated chunks. */
 237     size_t chunks_free;         /* Chunks in the free list. */
 238     size_t bytes_free;          /* Byte total of chunks in the free list. */
 239   };
 240
 241 /* Pick up the current statistics. */
 242 extern struct mstats mstats __P ((void));
 243
 244 /* Call WARNFUN with a warning message when memory usage is high.  */
 245 extern void memory_warnings __P ((__ptr_t __start,
 246                                   void (*__warnfun) __P ((__const char *))));
 247
 248
 249 /* Relocating allocator.  */
 250
 251 /* Allocate SIZE bytes, and store the address in *HANDLEPTR.  */
 252 extern __ptr_t r_alloc __P ((__ptr_t *__handleptr, size_t __size));
 253
 254 /* Free the storage allocated in HANDLEPTR.  */
 255 extern void r_alloc_free __P ((__ptr_t *__handleptr));
 256
 257 /* Adjust the block at HANDLEPTR to be SIZE bytes long.  */
 258 extern __ptr_t r_re_alloc __P ((__ptr_t *__handleptr, size_t __size));
 259
 260
 261 #ifdef  __cplusplus
 262 }
 263 #endif
 264
 265 #endif /* malloc.h  */