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/* Declarations for `malloc' and friends.
Copyright 1990 Free Software Foundation
Written May 1989 by Mike Haertel.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
The author may be reached (Email) at the address mike@@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#ifndef _MALLOC_H
#define _MALLOC_H 1
#ifndef __ONEFILE
#define __need_NULL
#define __need_size_t
#define __need_ptrdiff_t
#include <stddef.h>
#endif
#ifdef _MALLOC_INTERNAL
#ifndef __ONEFILE
#include <limits.h>
#endif
/* The allocator divides the heap into blocks of fixed size; large
requests receive one or more whole blocks, and small requests
receive a fragment of a block. Fragment sizes are powers of two,
and all fragments of a block are the same size. When all the
fragments in a block have been freed, the block itself is freed. */
#define INT_BIT (CHAR_BIT * sizeof(int))
#define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
#define BLOCKSIZE (1 << BLOCKLOG)
#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
/* Determine the amount of memory spanned by the initial heap table
(not an absolute limit). */
#define HEAP (INT_BIT > 16 ? 4194304 : 65536)
/* Number of contiguous free blocks allowed to build up at the end of
memory before they will be returned to the system. */
#define FINAL_FREE_BLOCKS 8
/* Where to start searching the free list when looking for new memory.
The two possible values are 0 and _heapindex. Starting at 0 seems
to reduce total memory usage, while starting at _heapindex seems to
run faster. */
#define MALLOC_SEARCH_START _heapindex
/* Data structure giving per-block information. */
typedef union
{
/* Heap information for a busy block. */
struct
{
/* Zero for a large block, or positive giving the
logarithm to the base two of the fragment size. */
int type;
union
{
struct
{
size_t nfree; /* Free fragments in a fragmented block. */
size_t first; /* First free fragment of the block. */
} frag;
/* Size (in blocks) of a large cluster. */
size_t size;
} info;
} busy;
/* Heap information for a free block (that may be the first of
a free cluster). */
struct
{
size_t size; /* Size (in blocks) of a free cluster. */
size_t next; /* Index of next free cluster. */
size_t prev; /* Index of previous free cluster. */
} free;
} malloc_info;
/* Pointer to first block of the heap. */
extern char *_heapbase;
/* Table indexed by block number giving per-block information. */
extern malloc_info *_heapinfo;
/* Address to block number and vice versa. */
#define BLOCK(A) (((char *) (A) - _heapbase) / BLOCKSIZE + 1)
#define ADDRESS(B) ((PTR) (((B) - 1) * BLOCKSIZE + _heapbase))
/* Current search index for the heap table. */
extern size_t _heapindex;
/* Limit of valid info table indices. */
extern size_t _heaplimit;
/* Doubly linked lists of free fragments. */
struct list
{
struct list *next;
struct list *prev;
};
/* Free list headers for each fragment size. */
extern struct list _fraghead[];
/* Instrumentation. */
extern size_t _chunks_used;
extern size_t _bytes_used;
extern size_t _chunks_free;
extern size_t _bytes_free;
/* Internal version of free() used in morecore(). */
extern void EXFUN(__free, (PTR __ptr));
#endif /* _MALLOC_INTERNAL. */
/* Underlying allocation function; successive calls should
return contiguous pieces of memory. */
extern PTR EXFUN((*__morecore), (ptrdiff_t __size));
/* Default value of previous. */
extern PTR EXFUN(__default_morecore, (ptrdiff_t __size));
/* Flag whether malloc has been called. */
extern int __malloc_initialized;
/* Hooks for debugging versions. */
extern void EXFUN((*__free_hook), (PTR __ptr));
extern PTR EXFUN((*__malloc_hook), (size_t __size));
extern PTR EXFUN((*__realloc_hook), (PTR __ptr, size_t __size));
/* Activate a standard collection of debugging hooks. */
extern void EXFUN(mcheck, (void EXFUN((*func), (void))));
/* Statistics available to the user. */
struct mstats
{
size_t bytes_total; /* Total size of the heap. */
size_t chunks_used; /* Chunks allocated by the user. */
size_t bytes_used; /* Byte total of user-allocated chunks. */
size_t chunks_free; /* Chunks in the free list. */
size_t bytes_free; /* Byte total of chunks in the free list. */
};
/* Pick up the current statistics. */
extern struct mstats EXFUN(mstats, (NOARGS));
#endif /* malloc.h */
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