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/*
$Id: malloc-private.h,v 1.4 2006/03/31 12:56:52 wg Exp $
Private header file for ptmalloc3, created by Wolfram Gloger
and released to the public domain, as explained at
http://creativecommons.org/licenses/publicdomain.
*/
/* The following file is replicated from malloc.c */
#ifndef MALLOC_PRIVATE_H
#define MALLOC_PRIVATE_H
#ifndef MALLOC_ALIGNMENT
# define MALLOC_ALIGNMENT ((size_t)8U)
#endif
#ifndef USE_LOCKS
# define USE_LOCKS 0
#endif
/* The bit mask value corresponding to MALLOC_ALIGNMENT */
#define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE)
/* the number of bytes to offset an address to align it */
#define align_offset(A)\
((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\
((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK))
#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
#define MAP_ANONYMOUS MAP_ANON
#endif /* MAP_ANON */
#ifdef MAP_ANONYMOUS
#define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS)
#define CALL_MMAP(s) mmap(0, (s), PROT_READ|PROT_WRITE, MMAP_FLAGS, -1, 0)
#else /* MAP_ANONYMOUS */
/*
Nearly all versions of mmap support MAP_ANONYMOUS, so the following
is unlikely to be needed, but is supplied just in case.
*/
#include <fcntl.h> /* for O_RDWR */
#define MMAP_FLAGS (MAP_PRIVATE)
static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */
#define CALL_MMAP(s) ((dev_zero_fd < 0) ? \
(dev_zero_fd = open("/dev/zero", O_RDWR), \
mmap(0, (s), PROT_READ|PROT_WRITE, MMAP_FLAGS, dev_zero_fd, 0)) : \
mmap(0, (s), PROT_READ|PROT_WRITE, MMAP_FLAGS, dev_zero_fd, 0))
#endif /* MAP_ANONYMOUS */
#define CALL_MUNMAP(a, s) munmap((a), (s))
struct malloc_chunk {
size_t prev_foot; /* Size of previous chunk (if free). */
size_t head; /* Size and inuse bits. */
struct malloc_chunk* fd; /* double links -- used only if free. */
struct malloc_chunk* bk;
};
typedef struct malloc_chunk mchunk;
typedef struct malloc_chunk* mchunkptr;
typedef unsigned int binmap_t;
typedef unsigned int flag_t;
struct malloc_tree_chunk;
typedef struct malloc_tree_chunk* tbinptr;
struct malloc_segment {
char* base; /* base address */
size_t size; /* allocated size */
struct malloc_segment* next; /* ptr to next segment */
flag_t sflags; /* mmap and extern flag */
};
typedef struct malloc_segment msegment;
#define NSMALLBINS (32U)
#define NTREEBINS (32U)
struct malloc_state {
binmap_t smallmap;
binmap_t treemap;
size_t dvsize;
size_t topsize;
char* least_addr;
mchunkptr dv;
mchunkptr top;
size_t trim_check;
size_t release_checks;
size_t magic;
mchunkptr smallbins[(NSMALLBINS+1)*2];
tbinptr treebins[NTREEBINS];
size_t footprint;
size_t max_footprint;
flag_t mflags;
#if USE_LOCKS
MLOCK_T mutex;
#endif /* USE_LOCKS */
msegment seg;
void* extp;
size_t exts;
};
/*
TOP_FOOT_SIZE is padding at the end of a segment, including space
that may be needed to place segment records and fenceposts when new
noncontiguous segments are added.
*/
#define TOP_FOOT_SIZE\
(align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE)
/* ------------------- Chunks sizes and alignments ----------------------- */
#define MCHUNK_SIZE (sizeof(mchunk))
#define CHUNK_OVERHEAD (SIZE_T_SIZE)
/* MMapped chunks need a second word of overhead ... */
#define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES)
/* ... and additional padding for fake next-chunk at foot */
#define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES)
/* The smallest size we can malloc is an aligned minimal chunk */
#define MIN_CHUNK_SIZE\
((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
/* conversion from malloc headers to user pointers, and back */
#define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES))
#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES))
/* chunk associated with aligned address A */
#define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A)))
/* pad request bytes into a usable size */
#define pad_request(req) \
(((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
/* The byte and bit size of a size_t */
#define SIZE_T_SIZE (sizeof(size_t))
#define SIZE_T_BITSIZE (sizeof(size_t) << 3)
/* Some constants coerced to size_t */
/* Annoying but necessary to avoid errors on some platforms */
#define SIZE_T_ZERO ((size_t)0)
#define SIZE_T_ONE ((size_t)1)
#define SIZE_T_TWO ((size_t)2)
#define SIZE_T_FOUR ((size_t)4)
#define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1)
#define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2)
#define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES)
#define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U)
#define IS_MMAPPED_BIT (SIZE_T_ONE)
#define PINUSE_BIT (SIZE_T_ONE)
#define CINUSE_BIT (SIZE_T_TWO)
#define FLAG_BITS (PINUSE_BIT|CINUSE_BIT|SIZE_T_FOUR)
/* head field is or'ed with NON_MAIN_ARENA if the chunk was obtained
from a non-main arena. This is only set immediately before handing
the chunk to the user, if necessary. */
#define NON_MAIN_ARENA (SIZE_T_FOUR)
#define cinuse(p) ((p)->head & CINUSE_BIT)
#define pinuse(p) ((p)->head & PINUSE_BIT)
#define chunksize(p) ((p)->head & ~(FLAG_BITS))
#define is_mmapped(p)\
(!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT))
/* Get the internal overhead associated with chunk p */
#define overhead_for(p)\
(is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD)
#endif /* MALLOC_PRIVATE_H */
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